Engine knowledge – fuel pump
First, function
1. To improve oil pressure (constant pressure): the injection pressure improve to 10MPa ~ 20MPa.
2. Control the fuel injection time (time): the time required to stop fuel injection and fuel injection.
3. Control the fuel injection quantity (quantitative): According to the diesel engine work, change the amount of fuel injection in order to adjust the engine speed and power.
Second, the requirements for fuel pump
1. Work order by diesel engine oil, and even the fuel supply tank.
2. Injection timing of each cylinder to be the same.
3. Non-oil tank to the same duration.
4. The establishment and supply of engine oil must be stopped quickly to prevent the dripping phenomenon.
Third, the classification of fuel pump
1. Plunger-type injection pump.
2. Pump – injector type, the fuel pump and injectors together.
3. Distribution type fuel injection pump rotor.
Fourth, the construction of a typical pump
Diesel engine fuel injection pump is commonly used in China: A pump, B-pump, P-type pump, VE pump, etc. The first three are piston; VE pump rotor pump distribution system.
(A) B-type fuel injection pump of the structural characteristics
1. Spiral trough peace-hole plunger plunger sleeve;
2. Fuel rod adjusting mechanism for the tooth, in front of engine gear lever with adjustable rigidity of the largest oil stopper (some with spring stopper);
2. Adjustable screw-type drive roller body parts;
3. Camshaft for the tangent cam with tapered roller bearings support the housing.
4. Pump for the integral, using an independent lubrication.
(B) P-type fuel injection pump of the structural characteristics
1. Hanging Cylinder assembly plunger and engine plunger sleeve, valve and other parts with a flange plate of the wheel cylinder with a solid steel sleeve fitted together into an assembly components. Gold stud with engine pressure directly fixed to the shell, forming a hanging structure. Sleeve can rotate a certain angle.
2. The Cylinder oil Cylinder steel sleeve to adjust the amount of the flange plate on the arc slot, release the clamping stud, turning steel sleeve, the sleeve that the engine wheel cylinder plunger with its rotation angle, change the the plunger into the back hole on the relative position of the chute, back to the time that the oil change.
3. Cylinder oil change start point adjustment following spacer sleeve flange plate, so that the plunger into the sleeve hole traces back to move up and down, thus changing the relative position of the plunger top can adjust the engine Wheel Cylinder oil starting point.
4. Ball off the plate angle adjusting mechanism in the oil-side surface of the drive sleeve welded steel balls 1-2, fuel rod cross-section was angle-shaped, at right angles to the edge of its level of opening a small square notch, working side slot sleeve on the ball and drive engagement. Adjustable wheel drive is not the body parts;
5. Fully enclosed box-type pump using non-open side of the overall seal pump, cover, and only under cover. Pump body rigidity, and can withstand high engine injection pressure without distortion, so that the plunger longer life;
6. Using a pressure type lubrication;
7. A dedicated preparatory trip inspection hole in the engine wheel above the plug body can be used to check a wheel cylinder of the hole is prepared to travel the same (with a special measuring instrument).