What is the role of the solenoid valve on the injector of an EFI diesel engine?

Solenoid valve is an industrial equipment controlled by electromagnetic. It is an automation basic component used to control fluid. It belongs to actuator and is not limited to hydraulic and pneumatic.Used in industrial control systems to adjust the direction, flow, speed and other parameters of the medium. The solenoid valve can cooperate with different circuits to achieve the desired control, and the accuracy and flexibility of the control can be guaranteed. There are many kinds of solenoid valves. Different solenoid valves play a role in different positions of the control system. The most commonly used ones are check valves, safety valves, directional control valves, speed control valves, etc.

Working principle

There is a closed cavity in the solenoid valve with through holes at different positions. Each hole is connected to a different oil pipe. In the middle of the cavity is a piston. There are two electromagnets on both sides. Which side of the magnet coil will be attracted to the valve body when it is energized. On the other hand, by controlling the movement of the valve body to open or close the different oil discharge holes, and the oil inlet is normally open, the hydraulic oil will enter the different oil discharge pipes, and then the piston of the cylinder is pushed by the oil pressure. Drive the piston rod, and the piston rod drives the mechanical device. In this way, the mechanical movement is controlled by controlling the current on and off of the electromagnet. In principle, it is divided into three categories: direct-acting solenoid valves, step-by-step direct-acting solenoid valves, and pilot solenoid valves.

injector control valve plate

installation attention

1. When installing, pay attention that the arrow on the valve body should be consistent with the flow direction of the medium. Do not install in a place where there is direct dripping or splashing water.The solenoid valve should be installed vertically upwards;

2. The solenoid valve should be guaranteed to work normally within the 15%-10% fluctuation range of the rated voltage of the power supply voltage;

3. After the solenoid valve is installed, there must be no reverse pressure difference in the pipeline.And it needs to be energized several times to make it suitable for temperature before it can be put into use;

4. The pipeline should be thoroughly cleaned before installation of the solenoid valve. The medium should be free of impurities. Install a filter before the valve;

5.When the solenoid valve fails or is cleaned, to ensure the system continues to run, a bypass device should be installed.

The fault of the solenoid valve will directly affect the action of the switching valve and the regulating valve. The common fault is that the solenoid valve does not operate, which should be investigated from the following aspects:

1. The solenoid valve terminal is loose or the thread is off, the solenoid valve must not be energized, and the thread can be tightened.

2. The solenoid valve coil is burnt out. You can remove the solenoid valve’s wiring and measure with a multimeter. If it is open, the solenoid valve coil will burn out. The reason is that the coil is damp, causing poor insulation and magnetic leakage, causing excessive current in the coil and burning. Therefore, it is necessary to prevent rainwater from entering the solenoid valve. In addition, if the spring is too hard, the reaction force is too large, the number of turns of the coil is too few, and the suction force is not enough to cause the coil to burn out. For emergency treatment, the manual button on the coil can be turned from the “0” position to the “1” position during normal operation to open the valve.

3. Solenoid valve jam: The matching gap between the solenoid valve slide valve sleeve and the valve core is very small, and it is usually a single-piece assembly. It is easy to jam when mechanical impurities are brought in or there is too little lubricating oil. The treatment method can be made by inserting a steel wire through a small hole in the head to make it bounce back. The fundamental solution is to remove the solenoid valve, take out the valve core and the valve core sleeve for cleaning, so that the valve core can move flexibly in the valve sleeve. When disassembling, pay attention to the assembly sequence of each component and the location of the external wiring, so that the reassembly and wiring are correct, and check whether the oil spray hole of the lubricator is blocked and whether the lubricating oil is sufficient.

4. Leakage: Leakage will cause insufficient air pressure, making it difficult to open and close the forced valve.The reason is that the sealing gasket is damaged or the slide valve is worn, which causes blow-by in several cavities. When dealing with the solenoid valve failure of the switching system, the appropriate time should be selected, and the solenoid valve should be processed when the solenoid valve is de-energized. If the processing cannot be completed within a switching gap, the switching system can be suspended and handled calmly.