調(diào)速器-外文文獻

GovernorThe role of governor is to limit the engine speed within a certain range. Running, engine load is carried by the ever-changing. When the load changes, especially sudden changes, the need to maintain the engine speed stability, with no parking or coaster accident. Governor is a device that automatically maintains speed stability. Diesel engines for power generation, asking them to speed almost constant in the synchronous speed, the speed characteristics of the governor demanding. Internal combustion engines work, such as the internal combustion engine output torque and the external resistance moment (load) are equal, working to stabilize. Such as the drag torque than internal combustion engine torque, the speed will be reduced; otherwise increased. Mechanical stability for the work to work, to be adjusted accordingly with the change of resistance of fuel supply, engine torque load with the outside world to adapt. The speed of the engine characteristics can be seen, the engine torque Me = f (n) curve is flat. In the diesel engine operation, such as the oil lever in a fixed position, engine speed torque characteristics by Me to change, while the external load is constantly changing. Such as bulldozers in the different wet and dry, hard and soft soil in different operations, there are significant changes in resistance torque. If there are small changes in resistance torque ( M), will cause a large speed change ( n), the diesel engine was unstable. To control the fuel supply to artificially adapt to load changes, which not only allows the driver fatigue, but also difficult to maintain speed and stability. Governor of automatic adjustment device. When the external load changes, it can automatically adjust with the change of the load amount of oil that the engine speed steady at a certain speed range. Vehicle or machinery is often the case load changing work, but also the situation encountered mutation load. Such as the bulldozer operation, when the dump, because of the sudden load lifted, fuel injection pump lever for a moment too late to move to reduce the amount of oil, the engine speed will rapidly increase, and then the fuel pump The role of velocity characteristics, but the amount of fuel injection pump oil increases circulation to promote the engine speed further increases. The results of this interaction, increasing the engine speed will be high speed in severe cases, or even "speed" accident, resulting in mechanical damage. In addition, low-speed diesel engine idling also frequently encountered (idle) of occasions, such as short-term parking, starting warm up, gear shift and so on. Diesel engine running at idle only a small amount of fuel supply, this part of the fuel energy can only be issued by the friction inside the engine to overcome, then the stability of the engine depends largely on the work of the internal friction changes and changes in cylinder acting relationship. These two losses can mean mechanical pressure Pm and the average indicated pressure Pi of the changes said. General engine with engine speed increases, the mean pressure Pm mechanical losses are slightly increased. In order to idle stability to speed increases, the mean indicated pressure Pi decreases, while it increases when the speed is reduced. Diesel engine idling, fuel lever position to a minimum fuel supply, then if for some reason (such as changes in lubricant viscosity) the engine's internal resistance increases slightly, its speed to slightly lower, but The role of the pump velocity characteristic, however, reduced amount of oil per cycle, which led into further reduce the speed, so cycles, the final engine will turn off; the other hand, such as diesel internal resistance decreases slightly, it will lead to engine Idle speed constantly increases, so the engine idle speed is very unstable. Therefore, the car engine is usually equipped with bipolar prevent the governor to achieve the purpose of speeding and idling stability. The role of governor is to change the course of Pi curves, so that Pi curve rises sharply with speed. This can keep the idle stable at high speed to prevent speeding. Comparison of working conditions in certain special diesel engines, such as rapid changes in work load and working conditions of construction machinery after the change in load required to maintain a certain range of engine speed (such as generator, air compressor, water pump, etc.), they are required governor with the whole program, this governor can not only prevent the idle speed and maintain stability, but also to automatically control the speed of any of the required conditions. All programs can also reduce drivers speed governor action to improve the use of diesel economy and labor productivity. 2. Plunger injection pump speed characteristics. Circulation pump depends on the amount of fuel oil adjustment lever (lever or gear lever) position. However, in practice fuel supply but also by the impact of engine speed. Lever position when the fuel timing, fuel injection pump fuel delivery cycle of the relationship with the speed changes, called the fuel pump speed characteristics. The work of its diesel engine has a great influence.