Therefore, cleaning the surface of copper castings and strengthening the appropriate process steps are the key to solving the silver plating quality of copper castings. Because the metal structure of copper castings is loose and porous, attention should be paid to the cleaning of each process during the electroplating process to prevent the solution remaining in the hole from affecting the next process; during electroplating, the impulse current density is about 3 times higher than that of ordinary parts, and the pre-plating time is longer than ordinary parts.

The high-precision copper strip used for the special-shaped frame of the cast copper transistor is generally made of a high-strength, high-conductivity alloy containing phosphorus and silver, and its section is composed of thick and thin sides. The blanks with special-shaped cross-sections are produced through pass rolling, chip milling, and high-speed forging, and then high-precision rolling is carried out to ensure that the elongation coefficients of the thick edges and thin joints are equal, otherwise the shape of the special-shaped strip cannot meet the needs of users.

The microstructure of copper castings is looser than that of rolled and rolled copper, and the appearance is rough and porous. To avoid or reduce defects such as component segregation, deformation and cracking of copper castings. When designing copper castings, not only must the geometric shape and size be determined according to the working conditions and the properties of the metal material, but also the rationality of the design must be considered from the perspective of the casting alloy and the characteristics of the casting Casting Automotive Mould Manufacturers process, that is, the obvious size effect and the problems of solidification, shrinkage, stress, etc.

When precasting, the parts and hanging tools should be shaken frequently to ensure the uniform color of the coating and prevent the appearance of spots during silver plating, which will affect the appearance of the coating; under the premise of shaking the workpiece, electroplating with pulse current density for 5 minutes, and then change to normal current density . In addition, some molding sand, paraffin and silicate substances often remain on the surface of copper castings, which often leads to local electroplating

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Fuel scours at higher pressure and speed, which is the main cause of wear of needle valve shaft and valve body nozzle. At the same time, the nozzle part of the shaft needle extends into the combustion chamber to contact the combustion gas, making the surface brittle, resulting in peeling or comb-shaped groove marks.. When the belt is widened, the fuel will leak and drip from the seat surface, causing coke deposits, difficult starting, black smoke, power drop, and fuel consumption increase. In this regard, the pressure regulating spring should be updated. The positive ring shape causes the fuel injection pressure to drop, the spray quality deteriorates and the fuel injection time shortens, and it should be replaced and repaired.004mm.

 

Causes the surface to stick to wear and get stuck.2-0. If there is no new pressure regulating spring to replace, a small washer of appropriate thickness can be added between the original pressure regulating spring and the pressure regulating spring seat to increase the preload of the spring. The fuel injection pump draws high-pressure fuel from the fuel injector inlet pipe joint through the fuel injection The oil passages in the body and the needle valve body enter the annular high-pressure oil chamber in the middle of the needle valve body.

 

Common faults and maintenance methods of fuel injectors The working conditions of the fuel injector are very harsh, the mechanical load and thermal load are high, and the installation and adjustment are not proper, often there will be failures such as poor spraying, dripping of the nozzle, carbon deposit, and even the needle valve stuck. The elastic force of the pressure regulating spring is insufficient. If there is air, remove it in time; whether the fuel supply of the fuel pump is normal; whether the fuel system is leaking; whether the fuel injection needle valve is stuck in the needle valve hole, if necessary, disassemble, clean and repair it. The sealing cone at the lower part of the needle valve is pressed against the sealing cone of the needle valve body and the nozzle hole is closed, and the fuel injection stops. The oil pressure acts on the pressure-bearing slope in the middle of the needle valve to form an upward axial thrust.

 

The fuel injector is composed of a fuel injector body, a tappet, a fuel injector coupling piece, a pressure regulating spring and other parts. Check whether there is air in the oil circuit. If the surfaces of the two parts are invaded by dust and mechanical impurities, the geometric accuracy and roughness of the guide surface will be destroyed, and the contact surface will generate high pressure and instantaneous high temperature. The matching clearance of the needle valve body is very small, only about . The fuel injector does not inject fuel. If the fuel entering the fuel injector contains particulate mechanical impurities, groove marks will be ground on the surface of the The best foundry cone. The injection pressure of the injector is too low, and the fuel atomization is poor and cannot be adjusted. The shaft needle head changes from the original cylindrical shape to the conical shape, and the nozzle hole diameter is also worn and lost.

 

Axle needle and nozzle are worn out.3mma. The sealing cone is worn. Generally, the cone angle of the valve body is 590, while the needle valve cone angle is 600, and the contact surface width is 0. When the fuel supply is interrupted and the oil flow pressure drops, the needle valve quickly returns to its position under the action of the pressure regulating spring. The problem of insufficient elasticity. In this case, new parts should be replaced. The compressed gas in the cylinder pushes the injector needle valve and passes through the oil return pipe to the high-pressure fuel pump, causing the diesel engine to stall without pumping oil.

 

When this thrust exceeds the pressure regulating spring When pressure is applied, the needle valve moves upward, and the fuel passes through the four nozzle holes at the bottom of the valve body and sprays into the combustion chamber in an atomized state. ③The guide surface of the needle valve is worn.002 to 0. It should be cleaned and maintained frequently, and replaced when necessary

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Spot casting aluminum alloy products welding is mainly used for body assembly, floor, door, side wall, rear wall, front axle and small parts, etc. Projection welding and roll projection welding are used for body parts, shock absorbers, valve stems, screws, nuts and small brackets, etc.

Electron beam welding is used for welding gears, rear axles, etc. Submerged arc welding is used for welding half-bridge casings, flanges, and pressure vessels of natural gas vehicles. resistance welding Ultrasonic welding is used for welding plastic parts Oxyacetylene welding is used for repair welding of body assembly Brazing is used for the welding of radiators, copper and steel parts, and hard alloys Laser welding is used for welding of different thicknesses of plates, body welding, etc.

Argon arc welding is used for welding and repair welding of oil pan, aluminum alloy and other parts. Argon gas or mixed gas shielded welding is used for welding of galvanized sheet of car body Multi-spot welding is used for underbody, truck compartment, door, engine cover and trunk, etc. Electrode arc welding is used for thick plate parts, such as brackets, spare tire frames, car frames, etc.

3Laser welding and cutting are used for underbody, gear, parts blanking and trimming. Special Welding 1Friction welding is used for welding of foreign devil's car valve, rear car, half axle, steering rod and hand tools. Seam welding is used for roof rain eaves, shock absorber heads, fuel tanks, mufflers and oil pans, etc Co2 protection welding is used for the welding of carriages, rear axles, frame, shock absorber stems, beams, rear axle housing tubes, transmission shafts, hydraulic cylinders, etc. Butt welding is used for steel ring, exhaust air valve, cutter, etc.

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It can also reduce maintenance Time and maintenance costs. Advice for female car owners 1. Even if the car is not driven very much, it should be maintained once a year. It is not recommended to directly consult the sales or maintenance consultants of 4S stores, because they usually hope that the more frequent the maintenance, the better, so please consult an experienced male car owner. The understanding of vehicle maintenance may only be limited to 'how long or how many kilometers' to maintain once, and many of the rules in maintenance are ignorant understand.

To give a simple example, if your car is only used for commuting to and from get off work every day, and the road conditions are good, and less severe driving, then you can appropriately extend the maintenance period; if your car has to go on poor road conditions every day, like that For dirt roads and gravel roads, the maintenance period should be appropriately shortened. Therefore, if you usually do some routine maintenance on your car, you can save costs and become more familiar with your car.

Of course, before you start, check the information as much as possible, and the accessories must be purchased accurately. Do it yourself maintenance  save money In general maintenance, the working hours of maintenance personnel account for a lot of maintenance costs. 2. Go to the 4S shop for maintenance according to your mileage, and strictly follow the mileage and items in the instruction manual for maintenance each time.

So today, Brother Bing wants to tell everyone how to save money and worry about maintenance. Reduce the number of disassembly repairs  This is a problem that most old car owners have reflected, that is, once the car is disassembled Aluminum alloy parts for repair, the problems will start to flow continuously. First, use various maintenance equipment and technologies to perform disassembly-free maintenance on the car. 2. Advice for male car owners who are not interested in cars 1;

For new car owners, how should maintenance be done to save a fortune? Although some new car owners are very good at driving, they are still very confused about car maintenance. If your car is mainly used in cities, and the speed is generally slower and less vigorous driving, it is recommended to clean the engine carbon deposit every 20,000 kilometers. generally there is such a practice, which is to refer to the manufacturer's maintenance cycle, and then adjust the maintenance cycle appropriately according to the actual use of the car. Read the manual more, know the mileage of your car for maintenance, and maintain it on time according to the requirements of the manual and your mileage.

This will prevent some intact parts from being damaged during the disassembly process. According to the recommendations of the 4S shop, pay attention to some parts with service life and replace them in time. The advantage of this is that it can maintain the performance of the car and save maintenance costs. In order to prevent the car from entering the maintenance period early, the correct approach is to reduce the frequency of disassembly and maintenance. 

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Frequently driving in a congested city is expensive.No. Generally, the replacement mileage of conventional brake pads is about 25,000-30,000 kilometers per driving.6 mm below the life line. Generally, the vehicle runs to 60,000~ It should be replaced at 100,000 kilometers, and the specific replacement cycle should be based on the vehicle's maintenance manual.

On a vehicle that has been driving on the highway for a long time, it can be replaced once after 30 thousand kilometers or even longer. If the discharge time displayed on the dashboard is suddenly prolonged, it is time to replace the battery. The timing belts and accessories should be replaced regularly within a specified period. Even if you have a timing belt in your car, once it breaks, you cannot replace it yourself.

In the following situations, you must pay attention to replacing the battery: The important indicator is to see if your wiper is dry or not, are there any scratches during use? The car wiper has been exposed to long periods of sunlight and rain, and it has been aging, which has caused the wiper to be unclean. Second, tires Replacement cycle: 50,000*80,000 kilometers To replace tires regularly, no matter how durable a set of tires is, they cannot be used for a lifetime. Eighth, air filter Replacement cycle: 10,000 kilometers

The replacement cycle of different cars is naturally different, so there is no absolute standard, because it depends on Casting Auto Mould the amount of dust and impurities absorbed by the air filter..6 mm, or the tread has reached the wear indicator mark, it must be replaced. Generally speaking, the service life of the resistance spark plug is 20,000 kilometers, the life of the Burkin spark plug is 40,000 kilometers, and the life of the iridium spark plug can reach 6*80,000 kilometers. Fifth, shock absorber Replacement cycle: no fixed time For all engines equipped with timing belts, manufacturers will have strict requirements.

It is also an air filter. When the headlights are not bright enough in the low-speed state, this time is actually reminding us that it is time to replace the battery. Auto parts For car tire replacement or scrapping, please refer to the following points: 1. Therefore, when the total travel distance reaches 80,000, it is recommended to consider replacing it. Tires with punctured shoulders. According to the quality of the wiper, the use environment, and the degree of maintenance, the replacement time of the wiper is different. 2. It may be replaced within two months

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