High Performance Delivery Valve K15 for Injection Pump Diesel Engine Spare Parts for ISUZU KUBOTA ISEKI

1. Structure of the delivery valve

(1) The oil delivery valve and valve seat are precision parts, made of high-quality alloy steel. Their guide holes, upper and lower end faces and seat holes are precision processed and ground, and cannot be interchanged after pairing.

(2) The cone part of the oil outlet valve is the axial sealing cone surface of the valve. The cone part of the valve slides in the guide hole and plays a guiding role. The tail is machined with grooves to form a cross-section to allow fuel to pass through. The cylindrical surface in the middle of the oil delivery valve is called the decompression zone, which forms a decompression volume with the sealing cone surface.

(3) The lower end surface of the valve seat and the upper end surface of the plunger sleeve are precision machined and tightly fitted. They are tightened by the compression nut with the specified tightening torque. There is a copper high-pressure sealing washer of a certain thickness between the compression nut and the valve seat. There is also a low-pressure sealing gasket between the oil delivery valve compression nut and the upper end face of the housing.

(4) A slotted reducing container is installed in the inner cavity of the oil delivery valve compression nut to reduce the volume of the inner cavity space, promote rapid injection stop, and limit the maximum lift of the oil outlet valve.

2. The function of the delivery valve

(1) Prevent oil dripping before injection and increase the injection speed: When the fuel injection pump supplies oil, after the oil pressure is higher than the preload force of the oil delivery valve spring and the residual pressure in the high-pressure oil pipe, the oil outlet valve The oil valve rises and its sealing cone leaves the valve seat. It is necessary to wait until the pressure relief band on the oil delivery valve completely leaves the guide hole of the valve seat before the fuel in the pump oil chamber can enter the high-pressure oil pipe.

(2) Prevent oil dripping after injection and increase the closing speed: When the oil supply is stopped, as soon as the lower edge of the pressure relief belt of the oil outlet valve enters the conduit, the path between the high-pressure oil pipe and the pump chamber is cut off. When the oil delivery valve is completely seated, it drops a distance h, so the volume of the high-pressure oil pipe is increased, causing the oil pressure to drop rapidly by 1MPa~2MPa, and the oil is cut off quickly and simply, preventing oil pressure fluctuations and "pipe shrinkage" from causing oil to rise. "And produce oil dripping after spraying. (3) Prevent fuel from flowing back and maintain a certain residual pressure in the high-pressure oil pipe.