The injection pump pumps the fuel to each injection nozzle.
The injection pump functions to control the fuel injection volume and timing.
1. Fuel suction
The feed pump draws the fuel from the fuel tank, and compresses it into the pump housing.
2. Fuel pumping
One plunger is used to send the highly pressurized fuel to each injection nozzle by reciprocated movement with rotating.
3. Injection volume control
The governor controls the injection volume and the engine output. The governor functions to control the maximum engine speed to prevent the engine from overrunning and stabilize idling speed.
4. Injection timing control
The timer controls the injection timing in proportion to the engine speed. The internal parts of the injection pump are lubricated and cooled by the fuel.
Summary of Operation
Turning the ignition switch on causes the fuel cut-off solenoid valve to be pulled in and the passage between the pump housing and the plunger to open. When the feed pump rotates, the fuel is drawn up from the fuel tank, passes through the sedimenter and the fuel filter, and enters the pump housing after the pressure is regulated by the regulating valve. The plunger draws the fuel from the pump housing into the pressure chamber during its downward movement (moves to the left), and compresses the fuel highly to distribute it to each delivery valve during the upward movement (moves to the right). After passing through the delivery valve, the fuel is introduced into the nozzles via the high-pressure pipes, from which the fuel is injected into the cylinders. At the same time, the internal parts of the pump are lubricated and cooled by the fuel. A portion of the fuel returns to the fuel tank from the over flow screw, in order to control the increase of the fuel temperature in the pump.