What is an idle electromagnetic cut-off valve on a gasoline engine and what is its function? Where is it?

When the idle speed increases, a thinner mixture is usually used, and the ignition time will be delayed. This can effectively reduce the emissions of carbon monoxide, CO, hydrocarbon HC and nitrogen oxides, but it will increase the engine temperature and make surface ignition (surface ignition is an abnormal combustion phenomenon, which means that after the engine turns off the ignition switch, the hot surface of the combustion chamber ignites the mixture in the cylinder, making the engine unable to stop. ) There is an increasing trend. In this case, the emission of pollutants will increase instead of decrease. , but also cause engine vibration and noise.

Therefore, a conical cut-off valve is installed in the idle oil circuit. The opening and closing of the cut-off valve is controlled by electromagnetic coil and spring, and the spring is controlled by ignition switch. When the electric fire switch is turned on, the electromagnetic coil is energized to attract the moving iron core to the left, and the conical stop valve opens the idle oil circuit, so that the idle system works normally. When disconnected, the moving iron core will block the idle oil circuit under the action of spring force, and the engine will stop immediately.

When the car goes downhill or slides, the throttle valve is close to closing, and the engine is dragged by the automobile transmission system to run at high speed. This working state is called forced idling.

During forced idling, the vacuum behind the throttle is very large, and the oil film on the gasoline and pipe wall evaporates quickly, resulting in a thick mixture. In addition, due to the high vacuum degree of the intake manifold, part of the waste is sucked into the intake manifold when the valves overlap, which will burn with the fresh air mixture, resulting in too much waste in the cylinder and slow combustion. As a result, CO and HC emissions increase under the condition of forced idling.

Use the forced idle cut-off solenoid valve.

, the oil supply to the main metering hole and the oil inlet hole can be cut off at the same time. Place the above phenomenon.