In the working process, the fuel injection process of the pump injector can be divided into two stages: pre-injection and main injection, and can also be divided into pre-injection, end of pre-injection, main injection, end of main injection and high-pressure oil chamber 5 processes of oil feeding. The fuel injection time and fuel injection quantity are jointly controlled by the auxiliary plunger, the fuel injection needle valve, the fuel injection needle valve return spring, the fuel injection needle valve damper and the electromagnetic control valve.

(1) Pre-injection. When the straight section of the cam is in contact with the rocker arm, the electronic control system supplies power to the solenoid control valve, so that the solenoid control valve needle valve moves to the left, cutting off the passage between the high pressure oil chamber and the low pressure oil passage, and at the same time, the pump oil column Under the action of the rocker arm, the plug moves downward against the elastic force of the return spring of the pump oil plunger, so that the oil pressure in the high pressure oil chamber rises rapidly. When the oil pressure rises to 18MPa, the upward thrust generated by the fuel on the cone surface in the middle of the injection needle valve is greater than the pre-tightening force of the return spring of the injection needle valve, and the injection needle valve will be lifted up to start pre-injection.

(2) Pre-injection ends. After the pre-fuel injection starts, the fuel injection needle valve continues to move upward. When the cam rotates over 1/3 of the fuel injection stroke, the lower end of the fuel injection needle valve damper enters the fuel injection needle valve damper hole, and the top of the fuel injection needle valve The fuel can only flow into the return spring cavity of the injection needle valve through a small gap. In this way, a so-called "hydraulic gasket" is formed on the top of the fuel injection needle valve, which prevents the fuel injection needle valve from continuing to move upward, so that the pre-injection amount of fuel is limited. As the pump plunger continues to move downward, the oil pressure in the high-pressure oil chamber continues to rise. When the oil pressure reaches the specified value, after the auxiliary plunger moves downward under the action of the high-pressure fuel, the volume of the high-pressure oil chamber suddenly increases. increase, the fuel pressure drops instantly.

At this time, the upward thrust on the central cone of the fuel injection needle valve decreases, and the fuel injection needle valve is reset under the action of the return spring of the fuel injection needle valve (the elastic force increases due to the compression of the auxiliary plunger), and the pre-injection Oil ends.

(3) After the main injection pre-injection ends, the pump plunger continues to move downward, causing the oil pressure in the high-pressure oil chamber to rise rapidly. When the oil pressure rises to greater than the pre-injection oil pressure (30MPa), the injection needle valve moves up and the main injection starts. Because the fuel oil pressure in the high pressure oil chamber rises very fast, the oil pressure in the high pressure oil chamber will continue to rise to about 205MPa.

(4) The main fuel injection ends. When the electronic control system stops supplying power to the solenoid control valve, the solenoid control valve needle valve moves to the right under the action of the solenoid control needle valve return spring, connecting the high pressure oil chamber and the low pressure oil passage. At this time, the fuel in the high pressure oil chamber flows to the low pressure oil passage through the electromagnetic control valve, the fuel pressure in the high pressure oil chamber drops, the fuel injection needle valve is reset under the action of the return spring of the fuel injection needle valve, and the auxiliary plunger is in the injection needle valve. Under the action of the needle valve return spring, the oil passage between the high pressure oil chamber and the needle valve return spring is closed, and the main injection ends.

(5) The high pressure oil chamber enters the oil. When the descending section of the cam is in contact with the rocker arm, the pump oil plunger moves upward under the action of the pump oil plunger return spring, and the high-pressure oil chamber generates a vacuum due to the increase in volume. At this time, the fuel in the low-pressure oil passage (connected with the oil inlet pipe) flows to the high-pressure oil chamber through the electromagnetic control valve until the high-pressure oil chamber is filled, so as to prepare for the next fuel injection.

Vigers is a professional supplier in China If you want to purchase fuel injector .

Beijing Vigers Co., Ltd. Beijing Vigers Co., Ltd. is located in Beijing, the capital city of China, which is a manufacturer specializing in machinery parts. The mian products are Fuel Injector, turbocharger, Hydraulic Pump, Cylinder HeadInjector Nozzles, Valve Assembly, Fuel Injection Pump, Machinery Parts and so on.

And Vigers’s products are exported to the United States, the United Kingdom, Finland, Germany, South Korea, Vietnam, India and other countries, and have won the recognition of foreign consumers with high quality and low price, and have a good reputation in foreign markets.

For more information, please contact:
Kaiyuan Business Office, Haidian District, Beijing, China
Telephone (+86) 15911077288. Email: [email protected].
Website: https://www.bjvigersinjector.com/en-US/