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As we all know, although there were already diesel passenger cars in the 1930s, the development of early diesel cars originated from the unique fate of the Soviet T-34 tank during World War II. Be easy to fire and be the best on the battlefield. The current Chinese market is like the early international market. When consumers talk about diesel vehicles, they often laugh and say, "The biggest advantage of diesel vehicles is that they will not catch fire." However, with the development of diesel technology, people are increasingly discovering the infinite charm of diesel engines: high torque, long life, low fuel consumption, and low emissions. Diesel engines have become the most realistic and reliable means to solve automobile energy problems. Nowadays, every new car launched in Europe will be equipped with a diesel engine model, but in China, only FAW-Volkswagen may be able to achieve this move. But an indisputable reality is in front of us: with the energy crisis, the greenhouse effect is gradually increasing, and people's requirements for power are increasing. Although electronic fuel injection has been widely used, gasoline vehicles alone are not enough to solve these problems. question. So in the hinterland of the automobile industry - Germany has not stopped research on diesel engines for a moment. Even in China, there are only more than 10 models currently using diesel engines, including 5 passenger cars such as Jetta, Bora, Audi, Caddy, and JAC Refine, Foton Surf, Jiangling Landwind, Huatai Terraca, Shanghai Wanfeng, Liaoning Shuguang Wait for 5 SUVs. The 2.5-liter diesel engine on the Ruifeng diesel vehicle is imported from South Korea`s Hyundai Motor Company D4BH engine, and the 4 diesel passenger cars of FAW-Volkswagen all use the diesel engine cooperated by German Volkswagen and Bosch. These 5 diesel passenger cars are all pillars. Plug pump, pump nozzle technology. The advantages of diesel engines are: fuel saving, environmental protection, strong power, economy, and easy maintenance. As long as the shortcomings are solved, there will be greater market prospects. The solution to realize electronically controlled diesel engines now seems to be a good solution. There are three technical roadmaps to realize diesel control, which are single pump, pump nozzle and high-pressure common rail. At present, major international auto parts suppliers are developing diesel common rail injection systems, such as: Bosch, Delphi, Siemens, Denso, VDO and Magna Marelli, which are the world's main suppliers of common rail injection systems At present, Bosch is the only company that produces common rail diesel injection systems in China. The three techniques are described below: 1. Unit pump technology Delphi uses a single pump system on heavy vehicles. In terms of cost, when the domestic engine is upgraded from Euro II to Euro III, if the single pump is used, the engine changes are very small, and only the external camshaft box replaces the in-line pump of the Euro II engine. When upgrading from Euro Ⅲ to Euro Ⅳ, the main structure of the engine body remains unchanged. Just change the mechanical injector in the Euro Ⅲ system to Delphi's electronically controlled injector to form a double solenoid valve single pump system. Without major adjustments to the overall structure of the engine, the emission level of Euro IV can be reached. In terms of performance, the current pressure used by the domestic single pump reaches 200 MPa. When it is upgraded to Euro IV, the pressure can reach 250 MPa. A system consistency control similar to common rail I2C is used on the single pump to optimize the performance of the entire system. In terms of oil supply control, if the double solenoid valve unit pump system is used, not only the pressure can be controlled, but also the injection can be controlled, and multiple injections can also be used. It can meet Euro IV or Euro V standards. At present, Delphi's dual solenoid valve unit pump system is mass-produced in Europe, mainly for Euro IV standard engines, and Euro V standard engine related systems are under development. Another advantage of the unitary pump system is its reliability and longevity. These performances have been proven in the European and North American markets by 10 or even 15 years of actual use and the use of millions of vehicles. The unit pump system can ensure low emissions and fuel consumption during engine use. At present, this very enhanced, very reliable performance and service life are still being further improved. Therefore, from Delphi's point of view, in terms of technology, it is believed that before 2010, most of the heavy-duty vehicle manufacturers in Europe and North America will adopt the unit pump system and pump nozzle technology. Delphi is also developing new systems required by new emissions regulations after 2010. 2. Pump nozzle technology Excellent air mixture is the key factor to improve the power performance and fuel economy of the diesel engine and reduce the emission rate and noise rate. This requires the injection system to generate a sufficiently high injection pressure to ensure good fuel atomization, and at the same time must precisely control the fuel injection start point and fuel injection volume. The pump nozzle system can meet the above stringent requirements. Therefore, as early as 1905, Mr. Rudolf diesel, the founder of the diesel engine, proposed the concept of pump injector, envisaging the integration of fuel injection pump and nozzle, eliminating the need for high-pressure oil pipes and obtaining high injection pressure. Diesel engines with intermittently controlled pump injection systems have been used in ships and trucks since the 1950s. Afterwards, Volkswagen and Robert Bosh AG jointly developed a solenoid valve-controlled pump injection system for passenger cars. Pump The main components are as follows: (1) One-way valve: When the engine is not working, it prevents fuel from flowing back. (2) Bypass valve: If there is air in the fuel, it will be discharged through here. (3) Orifice and filter: to collect and separate air bubbles in the oil supply pipe. (4) Pressure limiting valve 1: Open when the pressure in the oil supply pipe is adjusted to be greater than 0.75MPa. (5) Pressure limiting valve 2: Keep the pressure in the oil return pipe at 0.10MPa. (6) Fuel pump: The fuel pump is an intermittent vane pump, which has the advantage of supplying fuel even at lower engine speeds. The oil passage in the pump body keeps the oil pump rotor in a state of being soaked by fuel all the time, so that fuel can be delivered at any time. (7) Fuel distribution pipe integration: The fuel distribution pipe is integrated in the oil supply pipe in the cylinder head, and its function is to distribute fuel to each pump nozzle in equal amounts. Here, the fuel is mixed with the heated fuel and forced to flow back to the supply pipe by the pump nozzle. tubing. Make the temperature of the fuel flowing in the fuel supply pipe to each cylinder consistent. All pump nozzles are supplied with the same amount of fuel to keep the engine running smoothly. Otherwise, the oil temperature of the pump nozzles will be different and the pump nozzles will be supplied with different qualities of fuel. This will make the engine run rough and create extremely high temperatures in the first few cylinders. (8) Fuel cooling pump: to circulate the coolant in the cooling loop. When the fuel temperature reaches 70°C, the engine control unit switches it on through the fuel cooling pump relay. Pump nozzles are used in many domestic passenger cars, such as Bora TDI, Touran TDI and Audi TDI. Compared with the previous technology (such as plunger pump), the pump nozzle technology has been significantly improved, and its biggest advantage is that the injection pressure is greatly increased, and the injection pressure of the turbocharger pump nozzle can reach more than 200MPa. Since the injection pressure directly affects the efficiency of diesel combustion, the combustion efficiency of the pump nozzle is very high. 3. High pressure common rail technology "CRDI" is the abbreviation of Common Rail Direct Injection in English, which means high-pressure common rail diesel direct injection technology, CRDI technology, SDI (naturally aspirated direct injection diesel engine) technology, TDI (direct injection turbocharged diesel engine) technology Diesel engine technology developed for Bosch in Germany. Common rail system consists of high pressure pump, fuel injection pipe, high pressure accumulator (common rail), fuel injector, electronic control unit, sensor and actuator. The main contribution of the common rail fuel injection system is to completely separate the injection pressure generation and the injection process from each other. Through the precise control of the oil pressure in the common rail pipe, the pressure of the high pressure oil pipe has basically nothing to do with the engine speed. This innovation in diesel engine technology minimizes the vibration and noise of diesel engine models, while further reducing fuel consumption and making emissions cleaner. However, the fuel injection pressure of the common rail technology is lower than that of the pump nozzle system, which generally can only reach about 160MPa. Due to the wide adjustment of fuel injection pressure, diesel vehicles using common rail technology can better adapt to various working conditions, and it will not be difficult to start. Bosch was the first passenger car to mass-produce the common rail fuel injection system in 1997. At that time, Bosch and Mercedes-Benz jointly launched the diesel Mercedes-Benz C-class car with common rail technology. At that time, Alfa Romeo 156 was also the first passenger car to use high-pressure common rail. one of the cars. Among domestic cars, Huatai Hyundai uses a common rail injection system. Diesel common rail system has been developed for 3 generations. The first-generation common rail high-pressure pump always maintains the highest pressure, resulting in waste of fuel and high fuel temperature. The first-generation common rail system is designed for commercial vehicles, with a maximum injection pressure of 140MPa and a passenger vehicle injection pressure of 135MPa. The second-generation common rail system can change the output pressure according to the engine demand, and has the functions of pre-injection and post-injection. Equipped with an oil pump to control the amount of oil, the injection pressure can reach 160MPa. Even at low pressures, the system provides just the right amount of fuel injection pressure for actual conditions. Not only does it help reduce fuel consumption, but it also reduces fuel temperature, thereby eliminating the need for fuel cooling. Pre-injection reduces engine noise: A small amount of fuel is injected into the cylinder for a millionth of a second prior to main injection, which pre-heats the combustion chamber on compression ignition. The preheated cylinder makes the compression ignition after the main injection easier, and the pressure and temperature in the cylinder no longer increase suddenly, which is beneficial to reduce the combustion noise. Post-injection is performed during the expansion process to generate secondary combustion, increase the temperature in the cylinder by 200-250°C, and reduce the hydrocarbons in the exhaust. Bosch's second-generation common rail system products have been tried on passenger cars such as Volvo's S60, V70D5 and BMW's 230d. The third-generation common rail system has piezoelectric in-line injectors. In 2003, the third-generation common rail system came out, and the piezoelectric actuator of the piezoelectric (piezo) common rail system replaced the solenoid valve, thus obtaining more precise injection control. The oil return pipe is omitted, and the structure is simpler. The pressure can be adjusted elastically from 20 to 200MPa. The minimum injection volume can be controlled at 0.5mm3, reducing smoke and NOX emissions. The highest injection pressure reaches 180MPa. This system with newly developed piezoelectric in-line injectors enables a freer range of injection rate curves with pre-injection and post-injection. Compared with other injection systems, the common rail system separates the pressure generation from the actual fuel injection process. The "rail" is used as a high-pressure accumulator, and its internal fuel pressure is always kept at the optimum pressure suitable for the specific working conditions of the engine. Common rail systems can be easily installed into various engines. In addition, the common rail system also provides a wider expansion function and more degrees of freedom in the design of the combustion process, which can make the diesel engine run with lower emissions, better fuel economy and low noise . The electronically controlled common rail system is an electronically controlled system that domestic experts agree is the highest level at present and will dominate in the future. The special design of the injector can implement flexible multiple injections, and the injection pressure can be adjusted arbitrarily under different speed and load conditions. The benefits brought to the engine are extremely ideal indicators. Due to these factors, electronically controlled common rail technology has been widely adopted for the new generation of passenger car diesel engines.

How to judge the failure of the plunger and the oil delivery valve couple? When the diesel engine is working, loosen the high-pressure oil pipe joints of the fuel injection pump in turn. If a single pump does not produce oil or little oil, the speed and sound of the diesel engine will not change significantly, indicating that the plunger couple of the cylinder is or The plunger spring has failed. If the pump oil of each cylinder is normal, but there are still problems in operation, stop the machine, loosen the joint of the fuel inlet pipe of the fuel injection pump, and press the hand pump of the fuel delivery pump. If the oil can be pumped continuously, it means that the fuel injection pump of a certain cylinder The oil delivery valve assembly or spring is damaged. If it is difficult to start the diesel engine due to excessive wear of the plunger coupling, first remove the air from the oil circuit, use a screwdriver to pry up the lower seat of the plunger spring or the adjustment bolt, and pump oil at a faster speed. Or no pressure, indicating that the plunger coupling has been severely worn; if the pressure is particularly large, it may be that the fuel injector is blocked or the needle valve of the fuel injector is stuck. After confirming that it is not easy to start due to excessive wear of the plunger coupling, you can first try to increase the oil supply advance angle. If you still cannot start, you can adjust the maximum oil quantity limit screw on the governor to increase the oil supply. At the same time, the fuel injection pressure of each cylinder can be slightly reduced to achieve the purpose of starting in an emergency. Of course, when there are on-board accessories, replacing the plunger or the delivery valve assembly is the best solution.

The injector assembly is a mechanical component that is part of the fuel system whose task is to introduce fluid (in our case fuel) into the vehicle's engine. Unlike a simple transmission, fuel injectors allow a gradual and calibrated flow of just the right amount of fuel to the engine to function properly. Depending on the type of operation (electronic, mechanical or mechatronic), syringes can have different names.

1. Oil pumps and jacks should use specified oil grade working oil, generally No. 10 or No. 20 mechanical oil, and other hydraulic oils with similar properties can also be used, such as transformer oil. The oil poured into the oil tank must be filtered. It should be filtered once a month when it is used frequently, and the oil tank should be cleaned regularly. Generally, the oil level in the oil tank should be maintained at about 85%, and it should be replenished in time if it is insufficient. The oil added should be the same as the oil in the original pump. The oil temperature in the fuel tank should generally be 10-40°C, and it should not be used at negative temperatures. 2. The tubing should not be bent under working pressure. The oil tank connected to the oil pump and the jack should be kept clean and blocked with screws when not in use to prevent sediment from entering. The exposed oil nozzles of the oil pump and jack should be sealed with nuts to prevent dust and debris from entering the machine. After daily use, the oil pump should be wiped clean to remove the oil dirt on the oil filtering copper wire cloth. 3. The oil pump should not work under overload. The pressure of the safety valve must be adjusted according to the rated oil pressure of the equipment. Arbitrary adjustment is strictly prohibited. 4. Grounding the power supply, the case must be grounded, and the test run can only be done after checking the insulation of the line. 5. Before running the high-pressure oil pump, you should loosen the regulating valves of each oil circuit, and then start the oil pump. After the no-load operation is normal, then close the oil return valve, gradually screw the oil inlet valve stem, increase the load, and pay attention to the pressure. Whether the table pointer is normal. 6. When the oil pump stops working, the oil return valve should be loosened slowly, and the oil pipe joint nut of the jack can only be removed after the pressure gauge slowly returns to zero. It is strictly forbidden to disassemble and replace oil pipes or pressure gauges under load. 7. For the oil pump with double-acting jack, it is advisable to use a double-connected oil pump with two simultaneous oil delivery. 8. The oil-resistant rubber hose must withstand high pressure, and the working pressure must not be higher than the rated oil pressure of the oil pump or the maximum actual working oil pressure. The length of the tubing should not be less than 2.5m. When one oil pump drives two jacks, the specifications of the oil pipes should be consistent.

Iparts provides customers with mad in china and various brands of injectors, nozzles, plungers, repair kits, control valves, head rotor, ECU ,sensors, testers, oil pumps, etc: Denso, Caterpillar-Perkins, Bosch, Delphi, Cummins, Siemens and unit injectors.

What are the key points for the use and maintenance of diesel generator injectors? Diesel generators should avoid long-term overload operation to prevent the body from overheating and causing the needle valve coupling of the injector to be stuck. For diesel engines that have been stored for a long time, the fuel injector should be removed and immersed in clean diesel oil to prevent the needle valve from being corroded and unable to open and close flexibly. The use and maintenance of diesel generator fuel injectors can be improved from the installation position of the fuel injector pad, regular inspection, adjustment of fuel injector and fuel injection pump fuel supply advance angle, seasonal oil change and regular maintenance of diesel filters, careful cleaning and Replace the needle valve assembly, avoid the needle valve from being stuck, ensure that the diameter of the injector hole meets the technical requirements, and avoid long-term overloading of the diesel engine. In this article, Qihao, a professional diesel generator manufacturer, will give you a detailed introduction. (1) Improve the installation position of the injector pad. Because metal is most prone to wear and tear when working under high temperature conditions, while the nozzles of pintle and hole injectors protrude into the combustion chamber, most of the surface is in direct contact with the gas and is baked by high temperature and high pressure gas. It is the main reason for the wear of the needle cone surface of the injector and the guide surface of the needle valve. For pintle injectors, in order to prevent the entire injector from being baked by gas, a pure copper gasket of appropriate thickness can be installed on the head of the injector; for hole injectors, a V-shaped gasket can be installed, The design of the V-shaped gasket should make the outer diameter as large as possible, and the inner hole as large as possible at the top and small at the bottom, so as to facilitate disassembly and assembly when replacing the fuel injector to prevent gas intrusion. (2) Check and adjust the fuel injector on schedule. The fuel injector should be checked and adjusted every 1000 hours or so. If the opening pressure is lower than the specified value, the needle valve should be unloaded, put it into clean diesel oil, scrape off the carbon deposit with wood chips or copper chips, dredge the nozzle hole with fine iron wire, and then debug after reinstalling. It is required that the injection pressure difference of each cylinder on the same diesel engine must be less than 1.0MPa. (3) Check and adjust the fuel supply advance angle of the fuel injection pump on schedule. In order to make the diesel injected into the cylinder by the injector mix evenly and burn completely, it is necessary to check and adjust the fuel supply advance angle of the fuel injection pump regularly. If the fuel supply time is too early, it will make it difficult for the diesel engine to start, and failures such as cylinder knocking and increased vibration will occur; if the fuel supply time is too late, it will cause black smoke from the exhaust pipe, excessive engine temperature, and increased fuel consumption. . (4) Change the oil according to the season and maintain the diesel filter on time. Due to the high precision of the needle valve assembly and the small hole diameter of the injector, it is necessary to strictly select the clean diesel oil of the specified brand according to the seasonal changes, and maintain the diesel filter on time, and often discharge the oil in the filter and the fuel tank. Precipitated oil to prevent the intrusion of dust and impurities and accelerate the wear of the needle valve coupling. (5) Carefully clean and replace the needle valve coupling. When replacing the needle valve assembly, soak the needle valve assembly in 70~80°C hot diesel oil for 10 minutes, and then move the needle valve back and forth in the valve body in clean diesel oil to clean it thoroughly. In this way, the fault of sticking the needle valve due to the melting of anti-rust oil can be effectively avoided when the injector is working. In addition, when cleaning the needle valve assembly, do not touch it with other hard objects to prevent the needle guide surface from being scratched. (6) Prevent the needle valve from being stuck. When you loosen the high-pressure oil pipe joint, if you see a lot of bubbles or oil foam coming out, it means that the needle valve has been stuck in the open state, so that the compressed gas generated when the cylinder is compressed flows back into the high-pressure oil through the injector. At this time, if you touch the high-pressure fuel pipe with your hands, you will not feel the diesel pulsation or the pulsation is weak. If the needle valve is stuck, the fuel injector of this cylinder will not work well or not work due to the presence of particles in the oil and residual iron filings in the fuel injector. At this time, the needle valve coupling should be cleaned and assembled again. (7) Ensure that the diameter of the nozzle hole of the fuel injector meets the technical requirements. If it is determined that the insufficient fuel injection pressure of the injector is caused by the expansion of the nozzle hole, for a single-hole pintle injector, a steel ball with a diameter of 4-5mm can be placed at the end of the hole and gently tapped with a small hammer. Make the nozzle hole partially plastically deformed to reduce the hole diameter; for the multi-hole direct injection injector, because of its large number of holes and small hole diameter, it can only be lightly tapped on the hole end with a special punch. If the technical requirements are still not met after reinstallation, the needle valve coupling should be replaced. (8) Avoid long-term overloading of the diesel engine. The diesel engine should avoid long-term overload operation to prevent the body from overheating and causing the needle valve coupling of the injector to be stuck. For diesel engines that have been stored for a long time, the fuel injector should be removed and immersed in clean diesel oil to prevent the needle valve from being corroded and unable to open and close flexibly. With a modern production base, a professional technical research and development team, advanced manufacturing technology, a complete quality management system, and remote monitoring Qihao cloud service guarantee, we provide you with a comprehensive and considerate one-stop service from product design, supply, commissioning, and maintenance. Type diesel generator set solution.

What are the important functions of the fuel injector to improve the overall performance of the fuel injector? As an important part of the diesel engine, the fuel injector, the plug, and the oil outlet valve are called the three precision parts of the diesel engine. When the electromagnetic coil is energized, suction is generated, the needle valve is sucked up, the nozzle hole is opened, and the fuel is sprayed out at high speed through the annular gap between the needle of the needle valve head and the nozzle hole, forming a mist, so that the fuel is fully burned. The working condition of the fuel injector directly affects the engine's power, fuel consumption, durability and many other important performances. However, many car owners often ignore the maintenance of the fuel injectors, resulting in problems with the overall performance of the engine. Let us take a look at the maintenance precautions of the fuel injector together today: After the engine has been used for a period of time, due to the dust in the air and impurities in the diesel oil, the oil passage will be blocked or blocked, and the carbon deposits and gums produced during the combustion process will also adhere to the intake and exhaust valves, intake and exhaust valves, etc. On the air passage, throttle valve and combustion chamber, especially on the fuel injector of the diesel engine or the fuel injector of gasoline injection, the fuel injector is clogged and stuck, causing fuel injection leakage, poor atomization, or even no fuel injection , resulting in increased fuel consumption, decreased engine power, unstable idling, poor acceleration and difficult starting. According to tests, if 10% of the fuel injection quantity is blocked, it will lead to incomplete combustion of the engine, performance degradation, increased fuel consumption, and increased exhaust temperature. Therefore, it is necessary to clean all relevant systems of the engine. The main problem of fuel injectors is clogging. There are many reasons for clogging: 1. The carbon deposits generated during engine combustion are deposited on the fuel injector or the impurities in the fuel block the passage of the fuel injector. 2. After a certain mileage of the car, especially the driving condition of the truck is very poor, the fuel system will also form certain deposits in the harsh environment for a long time; 3. The colloids and impurities contained in diesel oil or the dust and impurities brought during storage and transportation will also form sludge-like deposits in gasoline tanks, oil inlet pipes and other parts; 4. When we maintain the vehicle, if we add too much engine oil, the excess engine oil will flow from the piston ring into the cylinder, adhere to the fuel injector, and form carbon deposits after high-temperature combustion; 5. The unstable components in diesel oil will also undergo chemical reactions at a certain temperature to form colloidal and resinous viscous substances. When these substances are burned in fuel injectors, intake valves and other parts, they will become hard Carbon deposits. Deposits in the fuel system of electronic fuel injection engines are very harmful, and they will affect the performance of high-precision components of electronic fuel injection systems. If it will cause the power of the engine to drop, it will also form carbon deposits in the intake valve and cause it to close tightly, resulting in unstable idle speed of the engine, increased fuel consumption, and excessive emissions; at the same time, carbon deposits will be formed on the piston top cylinder head. Due to the high heat capacity of carbon deposits and poor thermal conductivity, it is easy to cause engine knocking and shorten the service life. Therefore, the quality of the fuel injector plays a decisive role in the power of each engine. Regular cleaning of fuel injectors is very important to the engine. While strengthening the maintenance of the fuel injector, it must be noted that once the fuel injector is damaged, it is difficult to repair it. At this time, it is necessary to choose professional quality and durable fuel injector products for the maintenance of the fuel injector. maintenance work.

The fuel injector is a key part of the diesel engine, and its working quality directly affects the power, economy, emission and reliability of the diesel engine. According to the requirements of mixture formation and combustion, the fuel injector should have a certain injection pressure, injection stroke, and appropriate fuel injection cone angle. In addition, the fuel injector should be able to quickly cut off the fuel supply when the fuel injection needs to be stopped without oil dripping. Phenomenon. The components of the common rail system are sensitive to the water in the fuel system, especially the parts with precision valve components such as the injector, which are lubricated by diesel oil. Once the system enters water, it may cause problems such as corrosion of parts or poor lubrication. The common injector faults mainly include: ● Poor atomization of fuel injector Symptoms of failure: The power of the diesel engine drops, the exhaust emits black smoke, and the sound of the machine is abnormal. Fault analysis: When the fuel injection pressure is too low, the nozzle hole wears and has carbon deposits, the end surface of the spring wears or the elastic force decreases, the fuel injector will open early and close late, and poor atomization of fuel injection will occur. In addition, because the diesel mist with too large particle size cannot be fully burned, it will flow into the oil pan along the cylinder wall, which will increase the oil level of the engine oil, decrease the viscosity, deteriorate the lubrication, and may cause an accident of burning the cylinder. ● The needle valve is stuck Symptoms of failure: engine power drops, shakes, and even fails to start. Fault Analysis: Moisture or acidic substances in the diesel will cause the needle valve to corrode and get stuck. After the needle valve sealing cone surface is damaged, the combustible gas in the cylinder will also rush into the mating surface to form carbon deposits, causing the needle valve to bite to death. The oiler will lose its fuel injection effect, causing the cylinder to stop working. ● The guide surface of the needle valve and the needle valve hole is worn Symptoms: The power is reduced, the engine is difficult to start, or even unable to start. Fault Analysis: The needle valve reciprocates frequently in the needle valve hole, coupled with the intrusion of impurities in diesel oil, the guide surface of the needle valve hole will gradually wear out, so the gap increases or scratches appear, resulting in internal leakage of the injector increase, the pressure decreases, the fuel injection volume decreases, and the fuel injection time lags, causing difficulty in starting the diesel engine. When the fuel injection time is delayed too much, the diesel engine cannot even run, and the needle valve coupling should be replaced at this time. ● Oil dripping from injector Fault phenomenon: When the temperature of the diesel engine is low, it is difficult to start, and the exhaust pipe emits white smoke, and when the temperature of the diesel engine rises, it becomes black smoke. And high fuel consumption. Fault Analysis: When the injector is working, the sealing cone surface of the needle valve body will be subjected to frequent strong impacts from the needle valve, coupled with the continuous injection of high-pressure fuel, the cone surface will gradually appear worn or spotted, resulting in fuel injection dripping oil. When the temperature of the diesel engine is low, the exhaust pipe emits white smoke, and when the temperature of the diesel engine rises, it turns into black smoke. Check whether the movement of the needle valve is flexible, the taper surface should be free of wear and tight, otherwise it is necessary to replace the nozzle assembly with a new one. ● Oil return volume is too high Fault phenomenon: the fuel injection pressure is reduced, the fuel injection time is delayed, the engine power is reduced, and even the diesel engine is stalled. Fault analysis: When the needle valve coupling is severely worn or the needle valve body and the injector housing are not tightly matched, the oil return volume of the injector will increase significantly. At the same time, it is also necessary to pay attention to the valve plate, which will also The oil return volume of the injector is too large, which affects the performance of the engine. ● initial state When the solenoid valve of the fuel injector is not triggered, the fuel injector is closed, and the oil drain hole is also closed, and the small spring presses the ball valve of the armature to the throttle hole, forming a common rail high pressure in the valve control cavity. Similarly, the common rail high pressure is also formed in the fuel injector, and the common rail pressure maintains a balance between the pressure of the control plunger section and the pressure of the nozzle spring, and the opening force of the high-pressure fuel acting on the needle valve cone surface, so that the needle valve remains closed. state. ● Fuel injection start state When the solenoid valve is triggered, the armature will open the drain hole, and the fuel will flow from the valve control chamber to the upper cavity, and return to the fuel tank from the cavity through the oil return pipe, reducing the pressure in the control chamber; When the force acting on the control plunger is released, the nozzle needle valve is opened and the injector starts to inject fuel. ● Fuel injection end state Once the solenoid valve is powered off and is not triggered, the force of the small spring will press the solenoid valve down, and the ball valve will close the oil drain hole; after the oil drain hole is closed, the fuel enters the control room from the oil inlet hole to build up oil pressure, and this high pressure acts on the control chamber. On the plunger section, the rail pressure plus the spring force is greater than the pressure on the cone surface of the needle valve, so that the nozzle needle valve is closed. ● Conclusion: In order to avoid abnormal damage to the injector, it is necessary to change the oil according to the season and maintain the diesel filter regularly. Avoid low-quality fuel and low-quality filters, and avoid long-term high-load operation of the engine. At the same time, it should be pointed out that the common rail system is a high-pressure system, please do not disassemble it without authorization to avoid injury, and the injector is a precision component, please choose a professional maintenance point for maintenance. Do not disassemble without authorization to avoid secondary damage to the injector.

Debugging Method of Fuel Injection Pump and Its Plunger Maintenance The fuel injection pump is an important part of the diesel engine and is regarded as the "heart" part of the diesel engine. Once it fails, the entire diesel engine will malfunction. The first thing to do is to debug the oil supply time. Remove all the oil outlet pipe joints, turn the dial to make the oil outlet of cylinder 1 start to emit oil, align the scale with an integer scale as the 0 scale, and turn the dial according to the working order. Observe whether the oil supply interval angle of each cylinder is 60 degrees, and the deviation is within 0.5 degrees. Start the test bench, set the speed at 200rpm, set the number of fuel injections at 200 times, turn the control arm to the maximum fuel supply position, and press the counting button. The standard fuel injection volume should be 26ml. If the fuel injection volume is abnormal, the position of each cylinder's shift fork on the fuel supply rod can be adjusted separately. In addition to setting the speed at 900rpm, the standard fuel injection volume should still be 26ml. If the fuel injection volume is abnormal, it can be adjusted uniformly by adjusting the rated speed fuel volume adjustment screw. The debugging method of the idle fuel supply of the fuel injection pump is to start the test bench, set the speed at 250rpm, set the number of fuel injections at 200 times, and press the counting button. The standard fuel injection volume should be 6ml. If the fuel injection volume is abnormal, it can be adjusted uniformly by adjusting the idle fuel volume adjustment screw. The worn part of the fuel injection pump plunger is usually at the top. If the surface is dark or worn, it should be replaced. After testing, it is found that the plunger is slightly stuck, so it is necessary to pull out the plunger, wipe off the diesel oil on it, and carefully observe it under a magnifying glass. Find the traces of bumping and roughening, especially at the edges and corners of the matching cylinder, and carefully repair the plucking corners with an oil stone with a particle size of 800 or more.

What is common rail technology Common rail technology refers to a fuel supply method that completely separates the generation of injection pressure from the injection process in a closed-loop system composed of a high-pressure fuel pump, a pressure sensor and an ECU. The high-pressure fuel pump delivers high-pressure fuel to the public fuel supply pipe. Precise control of the oil pressure in the common oil supply pipe makes the pressure of the high pressure oil pipe independent of the engine speed, which can greatly reduce the variation of the oil supply pressure of the diesel engine with the engine speed, thus reducing the defects of the traditional diesel engine. The ECU controls the fuel injection volume of the injector, and the fuel injection volume depends on the pressure of the fuel rail (common fuel supply pipe) and the opening time of the solenoid valve. High pressure common rail technology details The common rail system separates fuel pressure generation from fuel injection. If the unit pump diesel injection technology is compared to the revolution of diesel technology, the common rail can be called a rebellion because it deviates from the traditional diesel system and approximates in sequential gasoline injection systems. Common rail systems open up new ways to reduce diesel engine emissions and noise. Europe can be said to be a paradise for diesel cars. In Germany, diesel cars account for 39%. Diesel cars have a history of nearly 70 years, and it can be said that diesel engines have developed by leaps and bounds in the last 10 years. In 1997, Bosch and Mercedes-Benz jointly developed the Common Rail Diesel Injection System (Common Rail System). Today in Europe, many brands of cars are equipped with common-rail diesel engines, such as Peugeot has HDI common-rail diesel engines, Fiat's JTD engines, and Delphi has developed Multec DCR diesel common-rail systems. The difference between common rail system and diesel injection system The common rail system is different from the previous diesel injection system driven by the camshaft. The common rail diesel injection system completely separates the generation of injection pressure and the injection process from each other. The injector controlled by solenoid valve replaces the traditional mechanical injector. The fuel pressure in the fuel rail is generated by a radial plunger high-pressure pump. The pressure has nothing to do with the engine speed and can be set freely within a certain range. . The fuel pressure in the common rail is controlled by an electromagnetic pressure regulating valve, which continuously adjusts the pressure according to the working needs of the engine. The pulse signal that the electronic control unit acts on the solenoid valve of the fuel injector controls the fuel injection process. The amount of fuel injected depends on the oil pressure in the fuel rail, the opening time of the solenoid valve, and the fluid flow characteristics of the fuel injector. Fuel injection pressure is an important indicator of diesel engines, because it is related to engine power, fuel consumption, emissions, etc. At present, the common rail diesel injection system has increased the fuel injection pressure to 1800 bar. Development in recent years In the past two years, cars equipped with direct-injection diesel engines have developed significantly in Europe, featuring high efficiency, excellent fuel economy, and reduced engine noise. The direct-injection diesel engine uses a pump nozzle system, which is used in the domestically produced 1.9TDI Bora, and the maximum injection pressure can reach 1800 bar. The pump nozzle direct injection system is good, but the fuel pressure cannot be kept constant. As the emission control becomes more stringent, higher and constant diesel injection pressure and better electronic control are required, so many manufacturers make more advantages Many diesel common rail systems are used as the development direction of diesel engines. This system has a high fuel pressure and can provide flexible fuel distribution control, and the fuel distribution, fuel injection time, injection pressure and injection rate can be flexibly controlled through the ECU. Through the control of the above characteristics, the common rail has made the responsiveness and driving comfort of the diesel engine reach the level of the gasoline engine, and it has remarkable fuel economy and low emission characteristics. Guaranteed high fuel pressure in all engine speed ranges, high injection pressure can obtain good combustion characteristics at low speed conditions Driven by the camshaft to control the axial plunger type distribution pump engine, the fuel system pressure is proportional to the engine speed The linear relationship creates insufficient fuel pressure at low engine speeds, while the common rail system can achieve very high fuel pressure in all engine speed ranges. The flexible electronic control system controls timing and injection pressure to achieve low emissions and high efficiency under various engine operating conditions. Since the pressure build-up is separated from the injection process, the engine designer has greater freedom when studying the combustion and injection process. The injection pressure and injection timing can be adjusted according to the requirements of the engine working conditions, so that the engine can achieve complete combustion at low speeds, so even at very low speeds, high torque can be obtained. The application of pre-injection technology has made further progress in reducing emissions and noise. Precise control of oil supply system The low-pressure fuel pump sucks the diesel oil out of the fuel tank, and supplies it to the high-pressure fuel pump after filtration. There is a solenoid valve in the low-pressure pump to control the fuel to the high-pressure pump chamber, and the fuel enters the tubular pressure accumulator-fuel rail. There is a pressure sensor on the common rail to monitor the fuel pressure from time to time, and transmit this signal to the ECU to control the fuel pressure in the common rail to the desired value by adjusting the flow. The injection pressure ranges from 200 to 1800 bar according to the different engine operating conditions, and then is injected into the cylinders separately through computer control. The common rail not only maintains the fuel pressure, but also eliminates pressure fluctuations. Fuel injection is a very complex joint operation of mechanical, hydraulic and electronic systems. To adapt to the working environment of the engine under various working conditions, the fuel must be filtered and pressurized before combustion, and injected at a certain injection rate at an accurate time. inside each cylinder. The engine computer controls exhaust gas recirculation, boosting, and exhaust aftertreatment systems for optimum engine characteristics and exhaust emissions. The latest generation common rail engine The compact structure of the injector makes the common rail system a practical solution even for small displacement 4-valve engines. At the end of 1999, the Smart equipped with a 3-cylinder common-rail diesel engine was born. Its displacement is only 799mL, its maximum power is 30kW, and its maximum torque is 100Nm at 1800-2800rpm. the The second-generation common rail engine is installed on the E320 launched by Mercedes-Benz, with a maximum power of 150kW, an output torque of 250Nm at 1000rpm, and 85% of the peak torque at 1400rpm, and a peak value of 500Nm in a wide range of 1800-2600rpm torque. The acceleration time from 0 to 100km/h is only 7.7 seconds, and the maximum speed is 243km/h. The comprehensive fuel consumption is 6.9L/100km, and the 80L fuel tank makes the battery life reach 1000km. The combined fuel consumption of the E320 equipped with a gasoline engine is 9.9L/100km. Three generations of diesel common rail system Diesel common rail system has been developed for 3 generations, it has strong technical potential The first-generation common rail high-pressure pump always maintains the highest pressure, resulting in waste of energy and high fuel temperature. The second generation can vary the output pressure according to the engine demand, and has pre-injection and post-injection functions. Pre-injection reduces engine noise: a small amount of fuel is injected into the cylinder for a millionth of a second prior to main injection, pre-heating the combustion chamber. The preheated cylinder makes the compression ignition after the main injection easier, and the pressure and temperature in the cylinder no longer increase suddenly, which is beneficial to reduce the combustion noise. Post-injection is performed during the expansion process to generate secondary combustion, increase the temperature in the cylinder by 200-250°C, and reduce the hydrocarbons in the exhaust. Due to its strong technical potential, today's manufacturers have set their sights on the third generation of the common rail system - the piezoelectric (piezo) common rail system. The piezoelectric actuator replaces the solenoid valve, so a more accurate Spray control. Without the oil return pipe, the structure is simpler. The pressure is elastically adjustable from 200 to 2000 bar. The minimum injection volume can be controlled at 0.5mm3, reducing smoke and NOX emissions. "Electronic control" means that the fuel injection system is controlled by a computer, and the ECU (commonly known as a computer) can precisely control the fuel injection quantity and fuel injection timing of each fuel injector, so that the fuel economy and power of the diesel engine can reach the best Balance, while the traditional diesel engine is controlled mechanically, and the control accuracy cannot be guaranteed. "High pressure" means that the pressure of the fuel injection system is three times higher than that of a traditional diesel engine, up to 200 MPa (while the fuel injection pressure of a traditional diesel engine is 60-70 MPa), the pressure is large and the atomization is good enough to burn, thereby improving the power performance. Finally, the goal of saving fuel is achieved. "Common rail" is to supply each fuel injector at the same time through the common fuel supply pipe. The fuel injection quantity is accurately calculated by ECU, and at the same time, fuel of the same quality and pressure is provided to each fuel injector to make the engine run more smoothly, thereby optimizing the diesel engine. Comprehensive performance. The traditional diesel engine injects fuel from each cylinder separately, the fuel injection quantity and pressure are inconsistent, and the operation is uneven, resulting in unstable combustion, loud noise and high fuel consumption. At present, domestically produced diesel engines with internationally advanced electronically controlled high-pressure common rail technology adopt the latest core technology of European and American diesel engines, which are obviously superior to traditional supercharged diesel engines. Compared with traditional supercharged diesel engines, it has 8% higher combustion efficiency, 10% lower carbon dioxide emissions, and 15% lower noise, completely changing the image of diesel engines as "noisy and black smoke" in people's minds. Structural principle The high-pressure common rail system uses a large-volume common-rail cavity to accumulate the high-pressure fuel output by the oil pump, eliminate pressure fluctuations in the fuel, and then deliver it to each injector, and realize injection by controlling the solenoid valve on the injector start and end. features Its main features can be summarized as follows: The high pressure in the common rail cavity is directly used for injection, which can save the booster mechanism in the injector; moreover, the high pressure in the common rail cavity is continuously high, and the driving torque required by the high pressure oil pump is much smaller than that of traditional oil pumps. Through the pressure regulating solenoid valve on the high-pressure oil pump, the oil pressure in the common rail cavity can be flexibly adjusted according to the engine load condition, economy and emission requirements, especially optimizing the low-speed performance of the engine. The injection timing, injection oil quantity and injection rate are controlled by the solenoid valve on the injector, and the injection oil quantity of pre-injection and post-injection and the interval with main injection can be flexibly adjusted under different working conditions. The high-pressure common rail system consists of five parts, namely high-pressure oil pump, common-rail cavity and high-pressure oil pipe, fuel injector, electronic control unit, various sensors and actuators. The fuel supply pump pumps the fuel from the fuel tank into the fuel inlet of the high-pressure fuel pump. The high-pressure fuel pump driven by the engine pressurizes the fuel and sends it into the common rail cavity, and then the solenoid valve controls the fuel injectors of each cylinder to inject fuel at the corresponding time. Before the main injection, the pre-injection injects a small part of fuel into the cylinder, and premixing or partial combustion occurs in the cylinder, shortening the ignition delay period of the main injection. In this way, both the increase rate of the cylinder pressure and the peak pressure will decrease, the engine will work more gently, and the temperature in the cylinder will decrease to reduce NOx emissions. Pre-injection can also reduce the possibility of misfire and improve the cold start performance of high pressure common rail system. Reducing the injection rate at the beginning of the main injection can also reduce the amount of fuel injected into the cylinder during the ignition delay period. Increasing the injection rate in the middle stage of the main injection can shorten the injection time and shorten the slow combustion period, so that the combustion can be completed within the more effective crank angle range of the engine, increase the output power, reduce fuel consumption, and reduce soot emissions. Rapid fuel cut-off at the end of main injection can reduce incomplete combustion of fuel, reduce smoke and hydrocarbon emissions.

5 minutes to let you know how to judge whether the injector is working properly If the single cylinder fuel injector does not work, the engine operation will be unstable, the vibration will be excessive during acceleration, and the power will drop. If your engine exhibits the above symptoms, the fuel injectors need to be checked. If you want to know what happens when the injector doesn't work, you can use the "cylinder fracture" test method to judge: pull out the injector of a certain cylinder of the engine at the current speed, that is, if the cylinder does not work, you can see Phenomenon when the fuel injector does not work. The above is the method to judge whether the fuel injector is working normally. Hope it helps you.

In 2022, the global Diesel Injector market sales will reach 100 million USD, and it is expected to reach 2029 USD 100 million, with a compound annual growth rate (CAGR) of % (2023-2029). At the regional level, the Chinese market has changed rapidly in the past few years. The market size in 2022 will be US$ million, accounting for about % of the global market. It is expected to reach US$ million in 2029, and the global share will reach % by then. In terms of consumption, the region is currently the largest consumer market in the world, with a market share of % in 2022, followed by and , which will occupy % and % respectively. The region is expected to grow the fastest in the next few years, with a CAGR of about % during 2023-2029. From the perspective of production, North America and Europe are the two largest production regions, occupying % and % market shares respectively in 2022. It is expected that the region will maintain the fastest growth rate in the next few years, and its share is expected to reach % in 2029. In terms of product type, piezo injector occupies an important position, and its share is expected to reach % in 2029. At the same time, in terms of application, the share of passenger cars in 2022 will be about %, and the CAGR in the next few years will be about % In terms of manufacturers, globally, the core manufacturers of diesel injectors mainly include Delphi, Bosch, Continental, Denso and Keihin. In 2022, the world's first-tier manufacturers mainly include Delphi, Bosch, Continental, and Denso, with the first-tier players occupying about 10% of the market share; the second-tier players include Keihin, Magneti Marelli, Hitachi, and Stanadyne, etc. Occupy a % share. This report studies the capacity, production, sales, sales, price and future trend of Diesel Injectors in global and Chinese markets. Focus on the analysis of product features, product specifications, prices, sales volume, sales revenue, and market shares of major manufacturers in the global and Chinese markets. Historical data is from 2018 to 2022 and forecast data is from 2023 to 2029. Major manufacturers include: Delphi Bosch Continental Denso Keihin Magneti Marelli Hitachi Stanadyne Siemens Caterpillar Perkins cummins Liebherr Isuzu mitsubishi According to different product types, it includes the following categories: Electromagnetic injector Piezo injector According to different applications, it mainly includes the following aspects: passenger car commercial vehicle Focus on the following areas: North America Europe China Japan