Research on the service life and repair interval of vehicle reducer

Through calculation and statistical results, a preliminary conclusion can be drawn after synthesis: For a large hump with heavy workload, the average number of brakes in one part of the reducer is about 300,000 vehicles per year, and the maximum is up to 500,000; the second part decelerates The average number of braking vehicles per year is about 7 million, and the maximum number of vehicles is 250,000; the average number of braking vehicles per year for the three-part reducer is about 40,000, and the maximum number of vehicles is 70,000.

For small and medium hump reducers, the number of actions will be significantly reduced. Life analysis of the whole machine, wearing parts, and wearing parts. The life of the reducer. The three-part reducer generally has a design life of 100,000 vehicles. Calculated based on the number of vehicles braked by the above-mentioned reducer per year, the minimum useful life is 14 years, and the average useful life is 25 years.

In fact, except for a small amount of TJY-1 and T-2-2 which have been used for 20 years, and T"KZ-1 (A50) has a 16-year history of use, other reducers may have been identified late (for example, TJKZ-B (50) , TJKI-D (50)), there is no long-term use record; some simply can not meet the service life requirements (such as TJKI-C).

But most of the three-segment reducers, generally around 10-12 years, due to the appearance of new types of reducers and overhaul and replacement. The design life of the reducer of the first and second parts has 1 million cycles (for example, TJK (Y) 3 one (50), 2 million cycles (for example, T suit (average 3 one (50), TK4 one (50)), and 30 10,000 vehicles (such as T not K, TJK 3-B (50)). If calculated according to the number of vehicles braked by the above-mentioned reducer per year, one part of the big hump can be used for 2 years, 4 years and 6 years respectively (according to each year * more Braking 500,000 vehicles), the average can be used for 3.3 years, 6.7 years and 10 years (according to the average annual braking of 300,000 vehicles).

The second part can be used for 4, 8, and 12 years less (250,000 more braking times per year), and an average of 6.7 years, 13.3 years, and 20 years can be used (according to the average annual braking number of tens of thousands of vehicles). During the use of the reducer, the wearing parts need to be replaced frequently to ensure the normal use of the reducer. However, the life span of the wearing parts is very different, which directly affects the performance of the reducer.

The life of wear parts of the reducer The strength of the main parts of the reducer can generally meet the design life except for casting and material defects. However, the failure and performance degradation of the reducer are mostly caused by excessive wear of the wearing parts. The following analyzes several wear parts that have the greatest impact on the performance of the reducer.

In addition to TJKI-c and TJKI-D using 50kg/m rails, the other reducers are mostly 60mm steel rails. The newly produced TJK3-B50 reducer adopts 75k left m rail reform. According to statistics, the brake rail with 50k leaving m can wear 3.5 to 450,000 vehicles; the brake rail with 60 k leaving m can wear 5.0 to 600,000 vehicles; the brake rail with 75 k leaving m can wear 65 to 750,000 vehicles; in large and medium-sized For the hump, the 60kg/m brake rail can be used for 1 to 3 years in the first and second parts; 8 to 12 years in the three parts. The 50kg/m brake rail can only be used for 6 to 8 years in the three parts, and the overhaul period is too short, so it is not recommended.

Sleeper plates and rail rubber pads The reducer sleeper plate bears the impact force of the rail falling when the reducer is relieved and prevents the reducer from crawling and floating on the side. It is also subject to the positive pressure of the passing vehicle when it is not braking. The sleepers on the main line are more vulnerable to damage. In addition, the rail rubber pad of the original reducer is not easy to replace, and the rubber pad is damaged or not replaced in time after aging, which may easily cause damage to the sleeper plate. After the sleeper plate is damaged, because it is not easy to repair and replace, it will often cause the reducer to be overhauled in advance.

Therefore, the life of the sleeper plate often determines the life of the reducer. The life of ordinary sleeper plates is generally 100,000 vehicles; the life of sleeper plates with abraded sides and sleeper grooves increased by iron plates can generally reach 200,000 vehicles. If you need to increase the life of the sleeper plate, you need to use a combined sleeper plate, that is, the worn side surface and the sleeper groove as replaceable parts. According to calculation and analysis, the life of the combined sleeper plate can reach 400,000 vehicles or more. TJK3-B50 reducer adopts combined sleeper plate. The life of rail rubber pads is generally 500,000 to 600,000 vehicles, so the rubber pads need to be replaced during medium repairs. The mid-repair period of TJK3-B50 reducer exceeds 10 to 1.2 million vehicle trips, so the rubber backing plate needs to be replaced during the period. For this reason, the rubber backing plate of TIK3-B50 reducer adopts the normal-line general type for replacement.

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Although the sides of the side guards also press out the role of stiffeners

Improve the heat transfer performance of the radiator. Compared with the series-fin reinforced radiator, the tube band radiator has the following main features. Heat dissipation port 2. When the air resistance of the tube-belt radiator can be reduced but the heat transfer coefficient increases, the heat transfer performance of the two radiators is compared. The characteristic of the tube-belt radiator tube belt is called the enhanced series fin radiator.

The key element of the tube-belt radiator is the corrugated belt, which is sectioned or not sectioned into a certain angle during rolling. Of wrong mouth shutters. In this way, it is beneficial to thin the adhesion layer of the airflow boundary layer on the corrugated belt, which can greatly increase the heat release coefficient of the air side, thereby saving copper tube. Compared with the reinforced radiator, each section can save the bottom of the copper tube plate. Including the reinforcement plate, each section of tube-belt radiator saves copper masking material. If calculated in ton of market price, the cost per locomotive of the main models of Ziyang Diesel Locomotive Factory can be significantly reduced. Moreover, in the brazing of the cooling flat tube end and the tube sheet, the reinforcing plate plays the role of increasing the weld seam, thereby enhancing the strength of the brazing seam. The gas welding process is simple and the production efficiency is high. It is rolled by a wave machine, omitting the cumbersome process of punching fins and fins in the production of fin-type radiators, and it is very convenient to assemble the radiator cooling core. The tin-baking furnace for cooling the core brazing and the hanging tin machine for cooling the flat tube can be used in common with the series-fin radiator. In addition, the hob for rolling the corrugated belt and the matching rolling machine are durable and can be adapted to the series of variable-depth tube belt radiators.

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Checking and repairing methods for poor heat dissipation of automobile engine air-conditioning system

Car engine and air-conditioning system have poor heat dissipation, causing the water temperature to be too high, which will cause the following failure phenomena:
1. When the traffic is not smooth-traffic jam or idling for a long time, the engine water temperature gauge shows too high, the electronic fan works for too long at high speed, the engine noise increases, and the temperature is too high when the air conditioner is turned on and the fault* is obvious.
2. When the air conditioner is turned on when the temperature is too high, the idling speed is unstable and the speed fluctuates too much, the acceleration is weak, and the engine makes abnormal noise.
3. After a hot car is turned off for more than ten minutes, it is not easy to get on the car when starting; sometimes it will automatically turn off when a hot car is driving.
4. The air conditioning refrigeration temperature is very cool when the car is cold, and the cooling effect of the air conditioning is not obvious when the car is hot; and there is a large resonance hum in the air conditioning system.
5. When the hot car is idling, the air-conditioning compressor clutch is frequently interrupted or even disconnected, causing the air-conditioning of the hot car to not be cooled.
The solution to the high water temperature of the automobile engine:
1. After the car is warmed up, check the water return of the return pipe at the upper end of the antifreeze storage tank. If the return water is not smooth or blocked, the water temperature will be too high.
Warm reminder: Do not blindly disassemble and replace parts during maintenance.
2. Check whether there is too much dust between the condenser and the water tank, and clean it thoroughly with high-pressure air to ensure that the water tank and the condenser have good heat dissipation performance.
Warm reminder: usually pay attention to wipe the dust between the condenser and the water tank.
3. When the car is warming up, check the temperature difference between the upper and lower water pipes of the water tank. If the temperature difference is too large, check the opening of the thermostat and whether the water pump has a rotation speed failure.
Warm reminder: The temperature difference between the upper and lower pipes of the water tank should not be too large.
4. Due to the irregular addition and replacement of antifreeze, the engine water channel and water tank will be blocked in advance and the water temperature will be high. The antifreeze is replaced once every two years, and original parts must be used when replacing and adding.
Warm reminder: After adding water to the engine cooling system, or the concentration of the added antifreeze exceeds 60%, it will cause the water temperature to be too high.
5. The high pressure at the high pressure end of the air conditioning system is too high; the air conditioning refrigerant or air conditioning refrigeration lubricating oil is overfilled; the self-adjustment function of the internal self-tuning air conditioning compressor fails, causing the high pressure to be too high; there is also the blockage of the air conditioning condenser, The above failures will increase the load of the engine, consume the heat dissipation performance of the cooling system, and cause the failure of the guide water temperature to be too high.
Warm reminder: Too little or too much air-conditioning refrigerant will reduce the cooling effect.

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Minute lubrication processing deep hole

Deep hole machining is the machining of holes with a ratio of hole depth to diameter greater than 10. In the machining industry, more holes are processed, but it is difficult to guarantee the tool life and the quality of the processed parts in the processing of deep holes. Solving the problems encountered in deep hole machining in machining and improving processing efficiency are the main research directions of deep hole machining. On the one hand, deep hole machining needs to choose suitable cutting tools to improve processing parameters. On the other hand, it is also necessary to choose a suitable and ideal lubrication system, because choosing a suitable and ideal lubrication method can improve the life of cutting tools and the quality of processed parts. . At the same time, it can also reduce the pollution of oil pollution to the environment and the harm to the human body. <br /> In deep hole drilling, traditional lubrication technology uses a large amount of cutting fluid pouring to achieve lubrication and cooling. Although this traditional lubrication method can also play a role in lubrication and cooling, it needs to consume a large amount of cutting fluid. In addition, the cutting fluid will be sprayed on the equipment and work site, which will have an adverse impact on the environment and the human body. In addition, the recovery and treatment cost of the waste fluid is also very high. The use of Doppeld deep hole drilling micro-lubrication system can easily solve the above problems, and at the same time, the processing quality and processing efficiency will be greatly improved, and the service life of the drill will be prolonged. The data shows that the operating cost of the system is reduced by more than 50%. <br /> The Doppeld deep hole drilling micro-lubrication system is mostly used in the processing of auto parts: crankshaft oil hole processing, engine box, etc. There are more deep holes in these processing, and the number of holes is relatively concentrated. To make the micro-lubrication play a better role, it is necessary to choose a drill bit with an internal cooling channel when selecting a drill bit, so that the micron-level oil mist can smoothly reach the cutting area. In addition, when choosing a lubricant, it is necessary to choose an environmentally friendly lubricant and fully consider the viscosity of the lubricant. Because the viscosity of the oil directly determines the atomization effect and the size of the oil mist particles after atomization. The pressure of a suitable gas source is also very important, because the size of the gas source pressure is an important factor that affects the formation of oil mist. In specific applications, if you use coated alloy drills to obtain higher processing efficiency, micro-lubrication can also play a better role. <br />

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The market for auto parts is becoming increasingly fierce

 

There will be unprecedented fierce competition in the domestic market for auto parts. In the face of this new change, the member factories of the “Automotive Federation” must actively prepare for the challenge. Make use of strengths and avoid weaknesses, and give full play to group advantages. In recent years, the member factories of the “Jin Auto Union” have gained a place in the auto parts industry market based on product quality, reputation and service attitude, and won the trust of the majority of users. However, some member factories are agricultural machinery system enterprises after all, and their product sales are affected. However, the agricultural machinery system has more than 200 agricultural machinery parts sales departments above the county level. In recent years, under the situation of reform and opening up, most of these sales departments have carried out the business of auto parts, and there are many sales departments dealing in auto parts. The business volume is still very large. The member factories should actively develop this potential market, make good use of the two annual agricultural machinery ordering meetings, and sign the contract for the supply of auto parts at the same time as the contract for agricultural machinery parts.

Capture market dynamics and seize key models. The current situation in the automobile market is different. Domestic-made diesel vehicles are popular because they have better power performance, low fuel prices and easier solutions. Especially in rural areas, people are willing to buy diesel vehicles, so the sales continue to be optimistic, so they are supporting diesel vehicles. Most of these diesel engine models are produced by agricultural machinery system manufacturers, and most of their supporting manufacturers are agricultural Supply repair parts. Therefore, we must seize this goal, work hard on these models, find a way, and conscientiously do a full-scale service in the production of supporting and social maintenance accessories and pre-sales, sales and after-sales.

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The heat dissipation effect of the radiator has a great influence.

　The easier way to check the frame is to use the frame gauge. The frame gauge is actually a set of observation needles. During inspection, hang the frame gauges at several different positions on the frame. When using, the three gauges must be used at the same time. The more gauges, the more accurate. If the frame is not deformed, the side needles of the frame gauges should be aligned during the inspection. If the observation needles are not aligned, it means the frame has been deformed. Plate steel plates between the tools as shown in the figure to avoid local stress and deformation. If the frame is accurately inspected, you can use a plumb hammer to draw the frame on the floor. This work must be very precise. The floor must be level and clean. If necessary, paste or nail paper on the floor, and use a plumb hammer in the car. The measurement points on the frame are projected on the ground, and then the distance between the points on the ground is measured by pushing the car away, as shown in the figure. If the frame has been deformed, as long as the amount of error is not large, it is still possible to correct it. The method of calibration varies. Some regulations must be calibrated in a cold state, the reason is that heating will weaken the strength of the frame. There are also suggestions for heating and correcting the frame, but the temperature should not exceed the dark red at this time. Hard work at this temperature will reduce the strength of the frame material and cause permanent damage. Especially the components that have undergone heat treatment, pay more attention to it. When heating, the heating area should be minimized, and attention should be paid to slow cooling. So as not to make the material brittle. Usually an oxygen-acetylene flame is used to heat the frame. It is also necessary to use some straightening tools, such as a thick I-shaped beam connecting the I-shaped beam and the frame of the chain to apply pressure to the chain to correct the pressure of the jack, or special topping tools made of screws, etc. The pre-compression should be correctly selected when correcting the frame. Location. And in the frame and correction, if the frame is severely deformed or broken, the frame needs to be replaced.

For automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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How to solve the sensor system failure

If the signal from each input sensor or switch indicates that the engine cooling water temperature is lower than 24C, or the following situations occur, such as the throttle valve is suddenly opening and closing or even completely closed, the atmospheric pressure is lower than 66.66kPa, the car is braking, When the car is downshifting from fourth gear to second gear and upshifting from second gear to third gear, the lock-up clutch will not be locked.

In addition, because the failure of the input device (such as a sensor or switch) will endanger the function of the electronic control system, the system will automatically switch to the failure mode control state when an input sensor or switch fails. The lock of the lock release has occurred.

Similar to Chrysler’s approach, when the engine cooling water temperature rises above the prescribed lower limit (24°C), the throttle position sensor and the vehicle speed sensor will become the key input devices that determine whether the lock-up clutch is locked or not. At this time, the electronic control unit will make its control decision based on the two sets of throttle openings as a function of the vehicle speed curve.

If the car is driving in third gear, when the throttle opening is small, the lock-up clutch of the torque converter can be locked when the vehicle speed is only 43km/h: when the throttle opening is large, unless the driving speed is as high as 89km /h, otherwise the lock will not occur. When the car is running in fourth gear, if the throttle opening is small, the speed at which the lock-up clutch is locked is 56km/h; and when the throttle opening is large, unless the vehicle speed reaches 89km/h, it will lock. Will not happen. In addition, in the third gear state, the throttle opening corresponding to the lockup of the torque converter lock-up clutch is greater than 8% but less than 59% from the hot idle position: while in the fourth gear state, this The throttle opening is changed to greater than 5% and less than 45%. There is also a lock-up hysteresis zone.

Generally speaking, the conditions required for locking to occur are that the throttle opening is small and the vehicle speed is high. Once it has been locked, in order to improve the driving performance of the car, a larger one should be allowed before the lock is released. Throttle opening and lower vehicle speed appear.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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The heat treatment process of auto parts consumes a lot of energy

 

The heat treatment process of auto parts consumes a lot of energy, so it is necessary to work to reduce the energy consumption in each treatment stage, which includes furnace improvement, carburizing process control, quenching medium, cooling rate, etc. However, the operation of these processes is directly related to the properties and hardenability of the processed steel with different compositions. In order to meet the requirements of advanced heat treatment technology, various types of steel have been studied from smelting. The improvement of these steels and related technology has greatly improved the performance and processing productivity of auto parts.

The chemical composition and hardenability of steel are the key factors to obtain the best heat treatment effect for auto parts. In order to obtain high-quality small-modulus gears in automotive products, it is necessary to carefully control the surface and core hardness of the gears. The development of direct heat treatment of steel, as well as the development of oxygen steelmaking furnace technology, continuous casting and rolling technology and other steelmaking technologies, have improved the selection of key points for precise control of chemical items. Microstructure control, reliability, application, size, reduce carburizing time. Hardenability, carbon potential, high performance of mixed heat treatment of quenching medium, composite heat treatment, furnace design can be economical and effective, heat source and load basin, insulation materials for the production of a variety of products, gas generated in the furnace body, furnace body size, linear mechanism Atmosphere control carburizing time is reduced, furnace body, carbon irrigation, maximum residual stress, carbon potential, carbon in steel, basic atmosphere carbon gradient, best quenching nitrogen, vacuum, plasma quenching technology, small deformation, quenching orange, fixture Structure, maximum residual stress, effective quenching cooling rate of quenching medium and carbon gradient fixture, use of temperature and quenching rate mixing technology heat energy, thermochemical reaction anti-rust surface film formation.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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Summary of key points for installing tires

Our previous article has given a detailed introduction to tire maintenance. *Recently, the editor has learned some neglected tyre knowledge, and I want to share it with you here.
The tire production date will be distinguished, but also anti-counterfeiting:
Tires are rubber products, so rubber aging will also occur. The shelf life of tire rubber is generally 4-5 years. Tire rubber will accelerate aging after the shelf life and cause tire performance to decline.
As shown in the picture above, “9MCR0810” is the tire production date code. Among them, the “0810” in the last 4 digits of * indicates that this tire is a product produced in the “8” week of the “10” year.
will look at the tire production date does not mean that the tire you buy must be new. Some unscrupulous businessmen modify the production date markings on tires through special molds, and sell tires with expired inventory as brand new tires, earning a high price difference. Generally speaking, unscrupulous businessmen achieve the purpose of tampering with the production date of the tire by polishing or removing the production date mark on the original tire, and then attaching a new mark. Therefore, the production date marks of these “rescheduled tires” and the tires are not a whole, and there are usually seams or unevenness on the edges of the marks. When buying tires, consumers should pay attention to whether there are seams or unevenness at the edge of the tire’s production date marking position to avoid buying inferior “rescheduled tires”.
When installing the tire, pay attention to the inner and outer directions:
Tire inner and outer reverse installation will greatly reduce the drainage performance and grip performance of single-guide or asymmetric tires. If you find that the tires are reversely installed inside and outside, please go to the repair shop to reinstall the tires immediately.
The outside of the tire is usually printed with the words “OUTSIDE”, the production date or the “DOT” mark. The outside of the tire can be judged by one of these three types of marks.
The *tap mark on the tire wall:
As a composite rubber body, the mass distribution of tires is difficult to be absolutely uniform. Therefore, some manufacturers will mark the tire * lightly on the sidewall of the tire. The wheel is mainly composed of three parts: wheel hub, tire and valve . The position where the valve is installed on the wheel hub has the highest quality. Therefore, when installing the tire, the tire * should be lightly marked corresponding to the valve installation, which plays a complementary role and makes the overall mass distribution of the tire tend to be balanced.
The maximum vibration point mark on the tire wall:
The maximum vibration point of the tire indicates the maximum point of longitudinal rigidity of the tire. When the tire rotates one circle, the maximum vibration point is at the position marked by the maximum vibration point. When a tire rotates on the ground once, the vibration force it bears at every angle it passes through is not equal. This phenomenon is called RFV (Radial Force Variation). When the RFV is too large, the tire will generate vibrations that can be perceived by the driver, which affects the driving comfort of the vehicle. Generally, large tire manufacturers will mark the position of this point on the tire during product inspection. If the vibration value of the tire product is found to exceed the standard, it will be treated as a waste product. The tire maximum vibration point mark is of little significance to consumers, so you will not see such a mark on all products in the market. However, RFV parameters are an important standard for the uniformity of tire materi al. RFV testing is a product quality inspection process that tire companies must carry out during production.

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Important measures to improve the performance of LPG public bus engines

 

The current layout of the radiator, fan and partition in the air intake compartment in the engine compartment is unreasonable. For example, there is a vortex in front of the radiator. L1 is not fully utilized, and the actual flow to the engine working area is very small, and the flow velocity is very low, resulting in poor convective heat transfer efficiency and poor heat dissipation in the engine compartment. In the improvement plan of the engine compartment layout, consider changing the orientation of components such as radiators and fans, changing the fan to face the engine body instead of the rear door, and removing the partition of the air inlet compartment in Zone A, which can effectively The high-speed air flow from the fan is used to improve the efficiency of convection heat transfer in the cabin and improve the heat dissipation performance of the cabin.

Using CFD and engineering heat transfer numerical analysis methods, the air flow vector diagram and the temperature distribution cloud map in the flow field in the engine compartment of a certain type of LPG gas bus are obtained, and the main high-temperature components in the engine compartment are analyzed based on the radiator. , Intercooler, engine block, turbocharger, etc., their heat is transferred to the outside of the engine compartment by the convection of air. The layout of various components in the engine compartment, especially the positions of various partitions and fans in the compartment, is one of the key factors that cause the heat dissipation characteristics of the engine compartment. Therefore, the engine compartment design based on automobile air heat transfer dynamics is one of the important measures to improve the performance of the LPG public bus engine.

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Aiming at the heat dissipation problem of high-power LED car headlights

 

For the research of automobile headlight radiator, some achievements have been made at home and abroad. In 2002, General Lighting Electric Co., Ltd. used an array of heat sinks behind the LED module to dissipate heat in its small power LED lamps. Aqkahn et al. used a piezoelectric fan to perform forced convection cooling of LEDs in 2004, and the result was that the cooling method lowered the temperature by 37°C compared with natural convection cooling. A loop heat pipe was used to cool LED street lights. Because the heat pipe has good flexibility, it can conduct fluid heat transfer in a long space, and can be installed at any position according to the designed street lamp. *The last experiment used the micron capillary material as the wick of the loop heat pipe. The result after *shows that the ambient temperature is 35°C, and in the case of natural convection, the surface temperature of the loop heat pipe is 73°C.

In 2005, the micro-channel cooling method was applied to the LED array, and a flat plate made of silicon material or metal matrix composite material MMC was installed under the LED module. The micro-machining method is used under the plate to process the plate into micro-channels, and the fluid is allowed to flow through these channels, and the fluid conducts the heat generated by the LED. The solution of cooling high-power LED array using micro-spray, and numerical optimization of the cooling system. In 2011, the Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences developed an industrial prototype of a high-power LED liquid metal radiator, and produced an industrial prototype of a 200W LED liquid metal radiator, which can ensure the highest temperature on the back of the substrate when the LED light source is operating at full load at room temperature. Below 45°C. The structure and principle of the high-power LED automotive headlight radiator designed above are relatively complicated, and many inconveniences such as difficulty in maintenance will occur in actual application in automotive headlights. In this article, aiming at the heat dissipation problem of high-power LED automotive headlamps, three simple and reliable heat dissipation devices are designed, thermal analysis is conducted through ANSYS, and a suitable heat sink is selected for actual processing, and the feasibility of heat dissipation is verified through experiments. .

For automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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The ability to integrate the application of multifunctional plastics in car body parts

 

No matter what kind of coating process is used for the surface quality of automobiles, the surface quality of the plastic parts of the car body must meet the requirements of Class A. Therefore, plastics must have good processing fluidity. In addition, in order to ensure the smallest possible gap size between parts under extreme temperature conditions, the thermal expansion coefficient of the body plastic parts must be small. If the body plastic part is used as the skin of the metal substrate, the quality of the appearance can only be guaranteed when the thermal expansion coefficient of the substrate and the surface layer are close. Generally, the coefficient of thermal expansion of thermoplastics is much larger than that of steel. Fillers are generally added to reduce the coefficient of thermal expansion. However, the addition of fillers tends to always reduce the surface quality. Fiber-reinforced thermosetting plastics can mostly meet the requirements of car body structural parts in terms of strength and rigidity, but its surface quality is often difficult to meet the A-level requirements. In addition, it is difficult to paint fiber reinforced plastics.

Another option to solve this problem is to use an injection compounding process, that is, a highly filled plastic and a colored high-quality film/sheet are compounded by injection. The composite parts produced no longer need to be painted and can meet the requirements of Class A surface quality. BASF cooperated with other companies to study the injection and compounding of long-fiber reinforced ABS with polymethyl methacrylate and ASA co-extruded film to produce the tail cover (luggage compartment cover) of the car; GE produced a polycarbonate co-extruded film. Extruded sheet (model: Sollx), which has been used in the production of body parts for mini-cars 2 Current status of the application of plastics on car bodies 2.1 Plastics for body parts are light in weight, good in processability, high in design freedom, and multi-functional The ability of plastics to be integrated in the application of car body parts is one of the most interesting aspects of plastics as a body material. Especially in today’s era where individualization is emphasized, the style of the car has a great influence on the customer’s desire to buy. The plastics currently used as bodywork mainly include sheet molding compound (SMC), reinforced reaction injection polyurethane (PUR-RRIM) and glass fiber reinforced thermoplastics. All three types use glass fiber reinforcement, mainly to meet the rigidity requirements of the car body.

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The progress of automobile manufacturing technology and the stricter environmental protection indicators

The technicality, complexity and particularity of lubricating oil products fully reflect the necessity of lubricating oil technical service work, which is embodied in the following aspects: Lubricating oil is a product with high technical content, and its product development and application research involve petrochemicals and machinery. Professional and other multi-disciplinary fields, cross-professional, cross-industry proficiency in lubricant expertise is not easy; any mechanical design must carry out a reasonable lubrication design, and any application of any kind of oil has problems. However, the lubricating oil market is wide-ranging, with many types of user industries, and users are in a state of dissociation and dispersal. It is necessary to establish a large number of expert service teams; there are many varieties of lubricating oils, and the specifications and grades are complex.

China has formulated lubricating oil classification standards with reference to international standards. Lubricants are divided into 19 categories according to application occasions. Each category 1 oil product is divided into several varieties. For example, E category internal combustion engine oil includes gasoline engine oil, diesel engine oil, railway internal combustion engine oil, and marine cylinder oil. , Medium-speed cylindrical diesel engine oil, two-stroke gasoline engine oil, etc. In the internal combustion engine oil, there are single-grade oil, multi-grade oil, and general-purpose oil. There are about a hundred brands in such a combination. Without certain lubricant business knowledge, it is difficult to choose suitable lubricants; due to the advancement of automobile manufacturing technology And environmental protection indicators are becoming more and more stringent. Lubricants, especially internal combustion engine oil, have become the fastest replacement products in the petrochemical industry. Compared with developed countries, China’s oil grade is quite different. The demand for lubricants in developed countries has a very small span. Only two grades of lubricants coexist in the United States, and only three grades of lubricants coexist in Europe. Taking gasoline engine oil as an example, China has the highest grade SL grade gasoline engine oil. There are also SC and even SA and SB grade gasoline engine oils, with a difference of seven or eight grades. Due to the country's insufficient enforcement of oil quality grades and users do not understand the basic knowledge that upgraded products can replace original oil products, it is difficult to promote new upgraded products and cannot use oil and oil products as in industrialized developed countries. Synchronize.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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Analysis of Misunderstandings in Automobile Maintenance

Caring for a car must pay attention to science. However, some problems often arise in car maintenance. Some people thought they were caring for the car, but in fact they accidentally damaged the car.

Maintenance experts remind you that the following wrong maintenance method is equivalent to destroying the car.

1. Waxing in a circle

The effect is poor. Many people habitually wax the car in a circle. This is an incorrect method. The correct way of waxing is in a straight line, alternating horizontal and vertical lines, and then in the direction of rainwater flow. In this way, the effect of reducing the concentric circular halo on the paint surface can be achieved.

2. Too much oil

Failure When the oil in the engine oil pan is insufficient, the friction between the bearing and the journal will be due to the small amount of oil, poor lubrication, aggravating the degree of wear, and even causing a bush-burning shaft accident. However, if there is too much oil, the crankshaft handle and the big end of the connecting rod will be violently agitated when the engine is working, which not only increases the internal power loss of the engine, but also increases the oil splashing on the cylinder wall and causes the oil burning failure. . Therefore, the oil in the engine oil pan should be controlled between the upper and lower engraved lines on the oil dipstick.

Three, the bolt is too tight

There are many fasteners connected with bolts and nuts on permanent deformation cars. It should be ensured that they have sufficient pre-tightening force, but they should not be over-tightened. On the one hand, the connecting parts will be permanently deformed under the action of external force; on the other hand, On the one hand, it will cause the bolt to produce tensile permanent deformation, and the pre-tightening force will decrease, and even cause the phenomenon of sliding buckle or breaking.

Fourth, the fan belt is too tight

The bearing load is heavy and the temperature is too high in summer. Some drivers think that increasing the tightness of the fan belt will cause the fan belt to be too tight, but they do not know that this is wrong. The fan belt should be properly tight, because too tight will cause excessive bearing load, aggravate wear, and increase power consumption. At the same time, it will also cause the water pump shaft to bend, elongate the belt and shorten its life.

5. The new battery does not charge

The first charge of a battery with a shortened life is called the first charge, and the first charge has a great influence on the service life of the battery. If it is not charged, that is, if it is used directly with “water”, the capacity of the battery is not high and its life will be shortened; if it is directly charged, it will also shorten its life. Generally, the initial charging of the battery is after filling the electrolyte, and then it can be installed and used after charging with a small current for about 1 hour.

VI. Add equipment in the car at will

A personal car that affects driving safety is a mobile home for car owners. There is nothing wrong with pursuing passenger comfort and luxury. However, some car owners install various equipment in the car by themselves. This modification, if not handled properly, will affect the performance and operation of the car. Reliability often brings adverse effects, and it is easy to leave sequelae or affect driving safety.

Seven, the cooling water temperature is too low

Wear and tear of the engine In the hot summer weather, some drivers blindly require the cooling water temperature to be as low as possible in order to prevent the engine temperature from being too high; some drivers simply remove the thermostat to achieve the purpose of cooling down. These practices are wrong.

Automobile engines are both afraid of heat and cold. If the cooling water temperature is too low, it will worsen fuel combustion, increase fuel consumption, aggravate wear, increase oil viscosity, and reduce engine power. Tests have shown that when the cooling water temperature of the car is 40-50 degrees Celsius, engine wear will increase by 60%-80%, power will be reduced by 25%, and fuel consumption will increase by 8%-10%. Therefore, the temperature of engine cooling water is not as low as possible. , Generally should be controlled between 80~90 degrees Celsius.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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There is no strict production standard for fake and inferior auto parts

 

For users, even if safety, environmental pollution and energy saving are not considered, counterfeit and inferior auto parts are very troublesome. Counterfeit and inferior parts do not have strict production standards and perfect inspection and testing methods. There are many hidden quality problems, short service life, and the frequency of failures during use is quite high. Failures occur every three days, and minor repairs occur in a few days. Overhaul not only causes certain economic losses to users, but also annoying.

The proliferation of counterfeit auto parts in the market is harmful to no benefit. It has caused huge economic losses and reputation losses to the national management departments, manufacturers, sellers and consumers, and seriously threatens the safety of people's lives and properties. In this case, counterfeit and inferior parts can make money by using other people’s brands and markets. With little input, high output, and small money, you can make a lot of money. The high profit makes some people stunned and unscrupulous to delve into how to produce fake and inferior auto parts. Some small businesses, handicraft workshops, and cottage industry workers do not work hard on the technology and quality of the products, but spend their money on opening up some relationships, finding some low-tech auto parts production, and then selling them under the brand of others. Under-brand companies with a little technical strength are targeting those imported auto parts or key parts with higher profits. Since the sales of fake and inferior auto parts are quite flexible, no matter how bad the quality is, there is no worries that there will be no sales. There is a huge distribution network of fake and shoddy cars all over the country, everywhere, everywhere, where there are cars, there are fake and shoddy auto parts.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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Verify the reliable simulation algorithm to simulate and calculate the dual-drain pipe radiator

 

Porous media conditions: model parameter method of porous media for calculation. The numerical simulation result table lists the simulation data of the heat sink with the wave distance of the heat dissipation band. The radiator simulation data shows the numerical simulation results of the overall temperature field of the tube-belt radiator when the wave distance of the heat dissipation belt is at the water inlet flow rate and the air inlet speed. Result comparison and conclusion analysis The error comparison between the experimental data and the simulation results of the radiator with a wave distance of the heat sink The distance radiators have been processed as shown in the table.

The numerical simulation results of the radiator are in good agreement with the wind tunnel test data, where the maximum error of the outlet water temperature is and the maximum error of the wind resistance is. The errors between the test data and the simulation results mainly come from two aspects. On the one hand, the inevitable errors caused by the test equipment, test methods, and data collection in the heat transfer wind tunnel test of the radiator are caused by the radiator numerical simulation. Errors caused by assumptions and simplifications in the calculation of its physical model. Although there are certain errors, the accuracy of this simulation algorithm can already meet the needs of actual engineering, and it has certain reference value for the future research on the fluid flow and heat transfer mechanism inside and outside the tube-belt automotive radiator. Performance comparison of double drain pipe and single drain pipe radiator. Simulation results. The core of double drain pipe radiator is made of aluminum; the core is high, the air inlet speed, the water flow rate, the water temperature, the water temperature, the air temperature, the air temperature, and the heat dissipation. Wind resistance temperature, inlet air speed, inlet water flow rate test, outlet water temperature simulation, outlet temperature error test, wind resistance simulation wind resistance error year, width and thickness respectively; the number of heat dissipation water pipes is; the number of heat dissipation bands is the double drain pipe type heat dissipation water pipe row is row, water pipe The outer side is wide, the wall of the water pipe is thick, and the water pipe is long; the wave height, wave distance, and thickness of the heat dissipation belt are as follows. The window opening angle of the heat dissipation belt is simulated and calculated using the proven and reliable simulation algorithm for the double drain pipe radiator.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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Inspection strategy of tire full-speed anti-breakage testing machine

Standard model and parameters Model and name Maximum test value accuracy/% EHB-100A standard dynamometer 10000kg 0.3 SZG-141B digital speed 10000rmin-10.0222 self-inspection conditions Working temperature 1035, the environment is dry, clean, and vibration-free.

The difference between the load display value of the self-checking equipment load and the actual force applied to the drum is the load error. (1) The installation of the EHB-100A standard dynamometer The standard dynamometer is fixed on the bracket, the dynamometer probe should be located on the plane composed of the rim and the center axis of the drum, and the end with the probe rests on the drum Up, the other end is towards the rim, as shown.

(2) Load test Choose 5 force points for load test on each station. In accordance with our factory’s inspection requirements for finished tires, five force points of 1, 2, 3, 4 and 5t are selected at the 1 and 2 stations. The installation of the EHB-100A standard dynamometer indicates the rim; 2 standard dynamometer ; 3 brackets; 4 drums and 4 stations to choose five force points 0.5, 0.8, 1, 1.5 and 2t. The equipment applies a load from the rim to the standard dynamometer through hydraulic transmission. When the equipment displays the selected afterburner value Xi (i=15), the readings Li of the standard dynamometer are recorded respectively.

(3) Calculation of load error The relative load error i corresponding to each point is calculated according to formula (1): i (%) = Xi-LiLi100 (1) The difference between the speed error of the self-checking device speed display value and the actual linear speed of the drum Is the speed error.

(1) Speed ​​measurement The SZG-141B digital tachometer is portable, so there is no need to install it. When testing, stick the reflective film on the drum and hold the steady tachometer. When measuring the speed, use the tachometer to obtain the standard value of the drum speed Ni first after the drum rotates stably. According to the diameter of the drum, the standard linear velocity value vi of the outer edge of the drum can be calculated as 0.3216Ni. Measuring 1 and 2 stations At the speed, the measured speed vi given by the equipment starts from 50kmh-1, and the speed is increased by 20kmh-1 each time until the speed reaches 150kmh-1, and then the speed is increased to 160kmh-1, and the standard speed Ni of the drum is measured with the tachometer. When measuring the speed at stations 3 and 4, the measured speed vi given by the equipment starts from 80kmh-1, and increases the speed by 20kmh-1 each time until the speed reaches 220kmh-1. At the same time, record the standard rotation speed value corresponding to each speed. The same method can calculate the standard linear velocity at each speed.

(2) Calculation of speed error The relative speed error i corresponding to each point is calculated according to formula (2): i(%)=vi-vivi100=vi-0.3216Ni0.3216Ni100 (2) Processing of self-check results at each point in load detection The absolute value of the corresponding load relative error is less than the load accuracy requirement, then the load test is qualified; the absolute value of the speed relative error corresponding to each point in the speed test is less than the speed accuracy requirement, then the speed test is qualified. If one of the items checked above is unqualified, the equipment is deemed unqualified and must be re-adjusted and tested until all items are qualified.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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Introduction to the importance of trace lubricants

In the application of micro-lubrication system, the generation of oil mist is very critical. There are many factors that affect the effect of MQL micro-lubrication.

At present, most users do not have a clear understanding of the characteristics of oils used under micro-lubrication conditions. They think that as long as the oil can be used in micro-lubrication processing, this is a wrong understanding. It is very important to correctly select micro-lubricating products.

First of all, mineral oil cannot be used in micro-lubrication processing, mainly because the oil mist particles produced by mineral oil are harmful to the human body, and the particle size generated by mineral oil atomization is large, the lubrication effect is not good, and mineral oil is not suitable for high-speed processing Lubrication in the state.

When the micro-lubrication system is used in cutting, the oil is very important. First of all, the oil must be environmentally friendly and should not cause harm to the health of the operators. At present, foreign countries have clear requirements for the oil used in the metal cutting processing field, and the use of MQL technology in the domestic machining field is still in its infancy. Because the micro-lubricating oil is atomized into 0.5-10 micron oil suspended particles, When selecting trace lubricants, the health and environmental protection characteristics of the oil should be considered first.

On the premise of ensuring that the oil is harmless to human health, it is necessary to consider the lubrication and atomization characteristics of the oil in the cutting process. The first thing to consider is that the oil should have a low viscosity. Only low-viscosity lubricants can be used without heating. It is atomized into ultra-fine suspended particles in the micron range, and can realize long-distance transportation without being affected by the high speed of the machine tool. There are many disadvantages of using mineral oil. Firstly, it is difficult to atomize without heating. Even if heated, the atomization effect of ultra-fine particles cannot be achieved. After the atomization of mineral oil, it is not easy to transport long-distance in the small channel, and it is easy to form oil. Droplets, especially affect the transportation in the main shaft, and easily cause oil accumulation in the pipeline, and the terminal lubrication effect is poor. The reason is that the oil mist that forms large particles is affected by the centrifugal force of the machine tool spindle. Compared with cutting fluid, the consumption of lubricating oil is greatly reduced in cutting under the condition of micro-lubrication, and the consumption per hour is below 50ml/h, which is much lower than the consumption of the traditional heating oil mist lubrication system.

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The reform presupposition of driving the vehicle’s secondary spring system at full speed

Comparison of the axial stiffness The bearing capacity of the combined spring P=P1+P2=(Gd18c3n1+Gd28c3n2) F=134.94F The bearing capacity of the original cylindrical spring P=Gd28c3n2=93.3F The axial stiffness of the combined spring The axial stiffness of the original spring= 134.94F93.3F=1.446, so the axial stiffness is obviously improved.

Comparison of lateral stiffness and bending stiffness The lateral stiffness of a single spring can be calculated by the following formula: Pr=Ed48nD32<1+43(HD2)2(2+L)>F The bending stiffness of a single spring can be calculated by the following formula: M=Ed416D2nH(2 +L) Fr is the combined spring axial stiffness. The original spring axial stiffness=d41D2n2H+d42D1n1Hd42D1n1H=1.225 This ratio shows that the improved combined spring has a greater increase in stiffness in all directions.

Improvement of the secondary spring The secondary spring is located between the bogie and the carriage. After the locomotive speeds up, the increase in the exciting force makes the secondary spring’s lateral stiffness low and its anti-resonance ability poor. For this reason, when it is ensured that the weight of the car body is not increased, the characteristics of the spring are changed by changing the shape of the spring. According to relevant data <1>, it is proved that the characteristic curve of a general cylindrical compression spring is approximately a straight line, the stiffness is stable, the structure is simple, and the manufacture is convenient. However, the spring is mainly along the axial direction, the transverse shear and bending rigidity is very poor, and the anti-resonance ability is poor. The reduced-diameter spiral conical compression spring has a gradually increasing characteristic curve, that is, the stiffness gradually increases, which is beneficial to eliminate or ease resonance, and has a compact structure and good stability.

concluding remarks

The design of the primary and secondary spring systems of high-speed electric locomotives plays a key role in the running quality of the entire locomotive. By improving their design, the exciting force generated during high-speed operation of locomotives can be greatly reduced, and the lateral stiffness and axial stiffness can be increased, thereby realizing active control of resonance of locomotives during high-speed operation and improving the safety of locomotive operation. Sex and stability.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large comaponent volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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The amount of wear between the mating parts is very small

In the process of highway construction, a large number of construction machinery and construction machinery combinations are required. Due to the gradual deterioration of their technical conditions during use, the engine power decreases, fuel consumption increases, exhaust gas exceeds the standard, transmission component gaps increase, and operating mechanisms do not work well. An error occurs in the working device. This is mainly due to the wear of the parts, the structure of the parts, the processing quality of the materials, the working conditions (climate and construction environment), the quality of the fuel and lubricating materials, the reasonable degree of use, the operation methods in the construction, the configuration of the machinery, and technical maintenance Caused by repair quality, etc., we will analyze separately below. Wear and damage of construction machinery parts During the use of the machinery, wear occurs due to the friction between the parts. Under normal circumstances, the wear process of parts is divided into D stages. **The stage is the running-in stage. The surface of the processed parts is rougher before running-in, so the wear is larger. Such as the running-in period of a newly purchased mechanical vehicle. During this period, with the increase of time, the working surface of the parts gradually wears out, so that the fitting clearance between the parts reaches the initial clearance clearance. The second stage is the normal working stage of the parts. After the mating parts are run-in, the surface of the parts is smooth and smooth, and the mating clearance reaches the design standard. During the use of the machine, the amount of wear between the matching parts is very small, and the matching gap grows slowly. The third stage is the accident damage stage. During the use of the machine, due to the increase in the fit gap, impact load is generated, the lubrication conditions of the parts become worse, and the sharp increase in wear may damage the parts and cause mechanical accidents. Mechanical wear Mechanical wear is caused by the friction between the surfaces of the parts. Although the surface of the parts is machined, it is still impossible to be absolutely smooth. When the surfaces of the parts are in contact with each other, they are uneven and easy to embed in each other. When the parts move, the raised metal particles are constantly falling off. When the fit gap increases to a certain extent, the parts will increase due to the impact load, and the lubrication conditions will be destroyed and wear will continue to increase. For automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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The influence of different types of nozzles on the thermal efficiency of the engine

 

The influence of combustion system parameters on engine performance. Fuel supply advance angle and fuel injection pressure test results show that the best fuel supply advance angle (CABTDC) of dimethyl ether during operation is: 19° under calibration conditions and 15° at low speed. This is 6°-9° smaller than the best fuel supply advance angle (25°) of diesel in operation; when the injection pressure of dimethyl ether is 15MPa (lower than the injection pressure of diesel 18MPa), the thermal efficiency is highest. This is because dimethyl ether has a higher cetane number, lower auto-ignition temperature and better atomization performance than diesel. Plunger Diameter The effects of three plungers with diameters of 8.5mm, 9.0mm and 9.5mm on the thermal efficiency of the engine were tested. The thermal efficiency η of the engine with different diameter plungers varies with the average effective pressure P. From this, it can be seen that the thermal efficiency of the engine increases with the increase of the plunger diameter. This is because the low calorific value and liquid density of dimethyl ether are only 64.7% and 80% of diesel. The increased fuel supply per cycle requires an increase in the diameter of the plunger to shorten the fuel injection duration to improve the performance of the engine.

Nozzle form and its depth into the cylinder The influence of 5 different forms of nozzles on the thermal efficiency of the engine was tested. Among them, the 5×0.32mm nozzle is the best, and the highest thermal efficiency is obtained. Compared with the 4×0.30mm nozzle used in the original machine, it has an increase in the number of nozzle holes, an increase in diameter, and an increase in the total flow area. The nozzle of this structure can be better with low intake swirl ratio (the best intake swirl ratio when using dimethyl ether is 1.4～1.8, which is much lower than the original engine swirl ratio 2.3) and large circulating supply Matching the amount of oil is conducive to the formation and combustion of the dimethyl ether mixture. Studies have shown that the best length of the nozzle to extend into the cylinder when using dimethyl ether is 5mm, which is longer than 3mm when using diesel. This is because dimethyl ether has good evaporation and atomization performance, and the spray cone angle formed by the fuel injected into the cylinder is large. In order to prevent the liquid fuel from hitting the bottom surface of the cylinder head and causing combustion deterioration, the length of the nozzle extending into the cylinder is required. Increase.

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Analysis on Several Control Systems of Motor Vehicle Monitoring and Management System

At present, domestic motor vehicle detection and management systems are divided into centralized control and distributed control according to the microcomputer control mode.

The centralized control system uses a master control machine to complete the registration of motor vehicles and the inspection of various items across the line, without a station control machine. The analog quantity, switch quantity and pulse signal of each station on the detection line are transformed and isolated directly into the person and the host. Therefore, the entire system structure is relatively simple, easy to install, debug and maintain, and the system cost is low. The main disadvantage of the centralized control system is the heavy task of the host, that is, to log in to the vehicle to be inspected, and to monitor the inspection situation of each station, the operator is often easy to ignore the other. In addition, the detection line is generally relatively long (the entire line is about 50 to 70 meters long), and the operator can only observe the detection conditions of each station at a relatively long distance. Once the detection is abnormal, it is difficult to find and deal with it nearby. In view of the above reasons, as well as the substantial reduction in computer prices, distributed measurement and control systems are currently used more frequently. The tasks of each microcomputer of this type of system are clear, the workload is relatively balanced, and it is easy to control the beat of the detection signal of each station to be sent to the nearest station computer, which improves the reliability of the system.

In some unexpected situations, the operator can manually operate the station machine. Therefore, the distributed measurement and control system is obviously superior to the centralized control system in terms of scope of application, scalability, maintainability, and resistance to single-point failure. The system consists of a log-in management machine, a server and 4 workstation computers to form a distributed measurement and control system. Moden hub (I-lzB) four-station machine, three-station machine, one-station machine for ordinary local telephone network Figure 2 In a small network, the Ethernet network is cheap, easy to install and maintain, and can meet the requirements of most customers. At present Use *widely. In the physical network topology of the LAN, the star structure has the characteristics of low cost, easy expansion, and easy fault isolation, so it is widely used. In addition to supporting network operating system WindowSNT, such as symmetric multi-processor, deep embedded security, preemptive multi-tasking and software fault-tolerant system (including striped sets with odd and even parity (including RAIDS), etc. In addition to advanced performance, it also provides a comprehensive Internet/Intranet solution. In particular, its industrial-grade stability, security and reliability brought by the NTFS file system are particularly necessary for the automatic detection line.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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Inventory situation of auto parts marketing companies

 

Auto parts marketing companies have special and complex inventory, but the inventory of each kind of parts is generally only a single digit. This is mainly because the merchants are willing to reasonably expand the variety of accessories with limited funds, the easier the sales will be. But such a library poses a problem, that is, these stocks are very small and may be out of stock at any time. But in fact, the different distribution time may be a few days or a few months. Therefore, how to grasp the law of sales and reasonably control the species and quantity; if the variety, quantity, method and timing of the purchase are the same according to the sales and inventory conditions. An important issue that the auto parts marketing industry has been studying.

Computers are generally used to manage auto parts marketing companies. Computer management has been used to improve work efficiency, but has developed to a certain degree that its variety and diversification of marketing methods make it almost impossible to work with computers. Slightly large-scale companies have realized single-machine management; many large-scale public companies have established their own local area networks; some multi-stores are realizing long-distance communications over a distance of tens of kilometers (BAIC 99 is a means of information communication. In these two aspects In response to demand, information media for advertising in the auto parts marketing industry emerged, such as publications such as “Huicong Business Information” and “Dark Horse Auto Parts Business Information”.

These “business conditions” increase the transparency of the auto parts market and are also beneficial to auto parts users. Various means of transportation bring convenience for import and sales, whether it is the needs of customers, competition or complementary needs of merchants, they all constitute the demand for fast logistics methods. Therefore, in the current auto parts marketing industry, sea, land, and air transportation have been used in the purchase and sale of auto parts. And there is a corresponding service industry that connects merchants and transportation departments into a one-stop service system. Merchants can send the goods to the designated place or deliver the goods at the designated place to our company only by contacting them by phone.

For automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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What are the five-axis processing of agricultural equipment at reasonable prices

The processing of parts and components for products in multiple fields requires the use of a relatively large number of machinery or requires a relatively long time for processing. In the production and processing of agricultural equipment, many manufacturers will choose high-level agricultural equipment five-axis processing plants for cooperation. Let us understand the matters needing attention in five-axis machining.

The five-axis in five-axis machining refers to three moving axes plus two rotating axes. Compared with common three-axis machining, five-axis machining refers to a tool that requires machining tools that can be positioned and connected in five degrees of freedom when machining parts with complex geometric shapes. The machine tools used in the more common five-axis processing plants on the market are called five-axis machine tools or five-axis machining centers. Five-axis machining is often used in the aerospace field to process body parts, turbine parts and impellers with free-form surfaces. The processing objects are more complex, and the data requirements are more accurate. The five-axis machine tool can process different sides of the workpiece without changing the position of the workpiece on the machine tool. This performance can improve the prismatic shape to a certain extent. Processing efficiency of parts. In addition, the five-axis processing technology can also be applied to the processing and production of agricultural equipment, adding vitality to the development of agriculture. The five-axis processing of agricultural equipment integrates computer control, high-performance servo drive and precision processing technology, and is used in the efficient, precise and automated processing of complex curved surfaces. Compared with three-axis Cnc Machining, from the perspective of technology and programming, the use of five-axis CNC machining for complex surfaces has the following advantages: it helps to improve processing quality and efficiency, reduces processing time, and saves time. Secondly, the process range can be expanded, and the applicable processing range is also relatively wide. In addition, it can meet the new direction of composite development to a certain extent.

For the work of modern agricultural production, modern agriculture is different from traditional agriculture, which is maintained by manpower alone, but relies more on the power of science and technology and the advancement and upgrading of equipment to enhance the vitality of agricultural production. Choosing a five-axis processing factory for agricultural equipment with good quality and low price will help provide better tools for agricultural production.

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Talking about 6 ways to reduce the defect rate of PCB for vehicles

The automotive electronics market is the third largest application area of ​​PCBs after computers and communications. With the gradual evolution and development of automobiles from traditional mechanical products to intelligent, informatized, and mechatronics high-tech products, electronic technology has been widely used in automobiles, whether it is engine systems, chassis systems, Security systems, information systems, and in-vehicle environmental systems all use electronic products without exception. The automotive market has obviously become another bright spot in the electronic consumer market. The development of automotive electronics has naturally driven the development of automotive PCBs.
Among the key applications of PCBs today, PCBs for automobiles occupies an important position. However, due to the special working environment, safety and high current requirements of the car, it has high requirements on the reliability and environmental adaptability of the PCB, and the types of PCB technology involved are also wide. This is a problem for PCB companies. Challenge; For manufacturers who want to develop the automotive PCB market, they need to do more understanding and analysis of this new market.
Automotive PCBs particularly emphasize high reliability and low DPPM. So, does our company have the accumulation of technology and experience in high-reliability manufacturing? Is it consistent with the future product development direction? In terms of process control, is it able to do well in accordance with the requirements of TS16949? Has a low DPPM been achieved? All these need to be carefully evaluated. Just seeing this attractive piece of cake and entering blindly will bring harm to the enterprise itself.
The following are representative parts of the special practices in the testing process of professional PCB manufacturers for automobiles, for reference to the majority of PCB colleagues:
1, the second test method
Some PCB manufacturers adopt the “secondary test method” to increase the rate of finding defective boards that have undergone the first high-voltage electrical breakdown.
2, bad board foolproof test system
More and more PCB manufacturers have installed “good board marking system” and “bad board error prevention box” in the light board tester to effectively avoid human leakage. The good board marking system marks the tested PASS boards for the testing machine, which can effectively prevent the tested boards or bad boards from flowing into the hands of customers. The bad board error-proof box means that during the test, when the PASS board is tested, the test system outputs the signal that the box is opened; on the contrary, when the bad board is tested, the box is closed to allow the operator to correctly place the tested circuit board.
3. Establish a PPm quality system
At present, the PPm (Partspermillion, parts per million defect rate) quality system has begun to be widely used in PCB manufacturers. Among the many customers of our company, it is worth learning from the application of HitachiChemICal in Singapore and the results*. There are more than 20 people in this factory who are responsible for the statistical analysis of online PCB quality abnormalities and PCB quality abnormal returns. Using the statistical analysis method of SPC production process, each bad board and each returned defective board are classified and statistically analyzed, and combined with auxiliary tools such as microsectioning to analyze in which production process the bad and defective boards are produced. According to the statistical data results, we can solve the problems in the process purposefully.
4. Comparative test method
Some customers use two different brands of PCBs for comparative testing in different batches of PCBs, and track the PPm of the corresponding batches, so as to understand the performance status of the two testers, and then choose a better performance tester to test automotive PCBs.
5. Improve test parameters
Choose higher test parameters to strictly detect this kind of PCB. Because if you choose a higher voltage and threshold, increase the number of high-voltage read leakage, which can improve the detection rate of PCB defective boards. For example, a large Taiwanese-funded PCB company in Suzhou uses 300V, 30M, and 20 ohms to test automotive PCBs.
6. Periodically verify the parameters of the tester
After long-term operation of the tester, the internal resistance and other related test parameters will all deviate. Therefore, the machine parameters need to be adjusted regularly to ensure the accuracy of the test parameters. Test equipment is maintained in a considerable part of large PCB companies for half a year or a year, and internal performance parameters are adjusted. The pursuit of “zero defect” automotive PCB has always been the direction of the efforts of the majority of PCB people. However, due to the limitations of process equipment and raw materials, the world’s top 100 PCB companies are still exploring ways to reduce PPm.

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How to maintain and repair cars on rainy days

 

There are frequent heavy rains in summer, and I can’t help but start worrying about my car. In heavy rain, the car will suddenly turn off the engine and lose control of the brakes. Among them, the tires are mostly flat. When the road is slippery on rainy days, a lot of puddles will be formed on the road surface. When the car passes quickly, it is very likely to damage the tires. I would like to remind those who drive to be careful to avoid foreign objects when driving on rainy days. When encountering puddles, the speed should not be too fast. When you feel that the steering wheel is getting heavier or the body is tilted, it is likely that the tire is flat. The owner should find a repair shop nearby. On rainy days, some unexpected problems may occur in the car, and drivers and friends should pay more attention to maintaining their car.

1. Clean in time. Some car owners think that it is not necessary to wash the car in rainy weather. In fact, the car should be cleaned in time in heavy rain. Otherwise, sludge will accumulate in the gaps between the front and rear of the tires, moisture will be hidden in it, and the car body will rust. In order to prevent the acidic substances in the rain from damaging the car body, the simplest and effective method is that the owner can prepare a dry cloth and wipe the car body briefly. When the weather turns fine, go to the repair shop or 4S shop to give the car to the car. All-round waxing and one-time polishing to seal the glaze.

2. The car jacket is more vulnerable to injury in rainy weather. In addition, many car owners are accustomed to putting on the car jacket, although it can prevent the surface of the vehicle from being damaged, but in windy and rainy weather, the car jacket will repeatedly beat the paint, especially when the wind and sand blow into the car jacket. Countless small scratches will be made on the car body, and the paint will darken over time.

3. Scratches should be repaired immediately. In addition, if there are scratches on the surface of the car, after the protective layer of paint is peeled off, rust will grow in the wet weather. Therefore, paint peeling or deep scratches on the car body should be repaired immediately, and the door and the drain hole on the bottom of the car body should be checked and cleaned frequently.

4. Self-check whether the brake fluid is damp. The wet weather in the rainy season will cause a large amount of water to accumulate on the brake fluid cup and enter the brake fluid. If moisture enters the brake fluid, the high temperature generated during the braking process of the vehicle will evaporate a large amount of water vapor, and the compressibility of the gas will cause brake failure or even failure.

The car owner can verify whether there is a problem with the brake system through three conditions: the brakes need to be stepped deeply, the brakes are audible, and the braking distance is longer than before. If one of these three conditions occurs, the vehicle needs to be repaired. The factory inspected.

5. Fog in the headlights is a hidden danger. On a rainy day, the headlights of the car are prone to water, the brightness is affected, and the direction of the headlights changes, which may damage the headlights and bring safety hazards. If there is water mist in the headlights, you can turn on the headlights. Whether the water mist in the car lights starts to disappear after 10 minutes of driving, and whether it can completely disappear after one hour; if there is still water mist, you must go to a professional after-sales service station for treatment.

6. Check the circuit. The car after the rain may have an impact on the performance of some parts of the car due to multiple water injections, and in serious cases, the car cannot be turned on normally. When the circuit is exposed to water, it is likely to cause a short circuit. If the engine stalls while traveling, it cannot be ignited again, otherwise it is very easy to cause the engine to be scrapped. If there is water, the circuit equipment should be processed in time after passing. You can use non-fiber paper towels and textiles to dry the circuits one by one before starting.

The automotive parts and parts machining, PTJ Shop offers the highest degree of OEM service with a basis of 10+ years experience serving the automotive industry. Our automotive precision shop and experts deliver confidence. We have perfected the art of producing large component volumes with complete JIT reliability, backed by the quality and long-term reliability our customers expect.

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Reprint Statement: If there are no special instructions, all articles on this site are original. Please indicate the source for reprinting.：Cnc Machining，Thank

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