JPH0310378Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a high-pressure injection fuel injection pump having an equal-pressure type delivery valve.

(Prior art) Equal pressure type delivery valves are, for example,
As shown in Publication No. 63358, the suction valve and the discharge valve are
The valve body, valve body holder, spring, and spring holder are inserted into the insertion holes formed in the delivery valve holder and the delivery valve seat in this order, and the rear spring holder is screwed in and assembled at the end, and the pressure inside the pipe is reduced during pump operation. Vigorous pulsations can loosen the spring retainer screws and change the spring setting force. To prevent this, a strong adhesive was applied to the spring retainer threads.

(Problem that the invention aims to solve) For this reason, isobaric delivery valves cannot be disassembled, and the internal parts cannot be replaced regularly or the seat surface can be corrected. If performance deterioration occurs, the delivery valve I had to replace the entire holder and delivery valve seat.

Therefore, the purpose of this invention is to enable disassembly even after assembly, thereby improving maintainability and assembly workability.

(Means for Solving Problems) The gist of this invention is to provide a suction valve and a discharge valve in parallel between a delivery valve holder and a delivery valve seat provided at the bottom thereof, and to A thread is carved into the outer periphery of the holder on the seat side, and a ring nut that fits externally and engages with the delivery valve seat is screwed onto the thread, so that the delivery valve seat and the delivery valve holder are integrated. That's true.

(Function) Therefore, since the delivery valve seat is integrated with the delivery valve holder by the ring nut, by turning the ring nut and removing it,
The delivery valve holder and delivery valve seat are separated, and the suction/return valve and discharge valve can be easily removed.

(Example) Hereinafter, an example of this invention will be described with reference to the drawings.

In the figure, a delivery valve holder 1 has a small diameter portion 1a in which a connection port 2 for connecting to an injection pipe is formed at the upper end, and a large diameter portion 1 provided with a stepped portion 3 as a boundary.
b, and downwards from the connection port 2.
Two suction and return passages 4 and a discharge passage 5 are formed, and both passages 4 and 5 are open at their lower end faces.

The suction return passage 4 is provided with a suction return valve 6, which will be described below, and the discharge passage 5 is provided with a discharge valve 7, which will be described below.

Further, on the large diameter portion 1b side of the delivery valve holder 1, a screw 8 is carved on the outer periphery of the lower end thereof. The portion where this screw 8 is carved is formed to have a somewhat small diameter.

The suction return valve 6 is arranged in a storage chamber 4a in which the diameter of the suction return passage 4 is enlarged, and includes a ball-shaped valve body 6a in contact with the delivery valve holder 1, a ball receiver 6b for receiving the valve body 6a, A valve spring 6c that presses the ball receiver 6b and a screw receiver 6d that receives the valve spring 6c.
It consists of. The discharge valve 7 is arranged in a storage chamber 5a in which the diameter of the discharge passage 5 is enlarged, and includes a ball-shaped valve body 7a that comes into contact with a delivery valve seat 9 described below, and a ball receiver 7 that receives the valve body 7a.
b, a valve spring 7c that presses the ball receiver 7b, and a spring receiver 7d that receives the valve spring 7c.

The delivery valve seat 9 has a disc shape, contacts the lower surface of the delivery valve holder 1 at its upper end surface, and its connection with the delivery valve holder 1 is regulated by a positioning pin 16 . This delivery valve seat 9 is provided with a suction return passage 10 and a discharge passage 11 which penetrate in the vertical direction at appropriately corresponding positions in order to communicate with the suction return passage 4 and the discharge passage 5. , is in contact with a plunger barrel 17 described below. On the outer periphery of this delivery valve seat 9, a stepped portion 12 is formed near the center.
The upper part of the step part 12 is formed to have a larger diameter, and the lower part thereof has a smaller diameter.

The ring nut 13 has a cylindrical shape, and has a thread 14 formed at the upper part of the inner side, and a step part 15 for engagement formed below the thread 14. The inner diameter of the ring nut 13 corresponds to the outer shape of the delivery valve seat 9.

The plunger barrel 17 is inserted into a hole 19 formed in the pump body 18, and is assembled so as to be engaged and suspended at a stepped portion 20. A fuel suction hole 22 that communicates with a fuel reservoir 21 is opened in this plunger barrel 17, and the amount of fuel delivered is controlled by this hole 22 and a lead 24 of a plunger 23 inserted into the plunger barrel 17. It is something that exists.

In the above structure, the delivery valve holder 1, the delivery valve seat 9, and the plunger barrel 17 are assembled by first inserting the plunger barrel 17 into the hole 19 of the pump body 18 from above;
After that, the delivery valve holder 1 is positioned using the ring nut 13 and the positioning pin 16.
and the delivery valve seat 9 are combined and inserted into the hole 19 of the pump body 18. Finally, the flange 25 with the hole formed therein is inserted into the delivery valve holder 1, the flange 25 is engaged with the stepped portion 3 of the delivery valve holder 1, and then bolts 26 are tightened. Then, the delivery valve seat 9 and the plunger barrel 17 are firmly fixed to the pump body 18, and sufficient oil-tightness of the adhesive surfaces can be maintained.

Therefore, even if the ring nut 13 becomes loose, a strong force is applied from the delivery valve holder 1 to the ring nut seat 9 and the plunger barrel 17, so that problems such as the joint surfaces spreading out will not occur.

(Effects of the invention) As described above, according to this invention, the delivery valve holder and the delivery valve seat are integrally formed with a ring nut. The discharge valve can be removed, and maintenance such as conversion of the suction valve and discharge valve and correction of the seat surface can be performed.

In addition, when assembling the pump body, it is possible to simply insert the delivery valve seat and the delivery valve holder without considering the fitting of the positioning pin between the delivery valve seat and the delivery valve holder, as in the conventional case. is improved.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view showing an embodiment of this invention. 1...Delivery valve holder, 6...Suction return valve,
7...Discharge valve, 8...Screw, 9...Delivery valve seat, 13...Ring nut.

Claims (1)

[Scope of utility model registration request] A suction valve and a discharge valve are provided in parallel between the delivery valve holder and a delivery valve seat provided at the bottom thereof, and the delivery valve holder is provided with a thread on its outer periphery on the seat side, A fuel injection pump characterized in that a ring nut that fits externally and engages the delivery valve seat is screwed onto the screw, so that the delivery valve seat and the delivery valve holder are integrated.