JPH0118834Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel pressure regulating valve device for regulating fuel pressure applied to a fuel injector of an internal combustion engine, particularly an electronic fuel injection system.

As the above-mentioned type of fuel pressure regulating valve device, for example, one described in Japanese Utility Model Application Publication No. 51-101429 is already known. This device is biased by a spring, and has a diaphragm that receives fuel pressure on one side and negative pressure from a negative pressure source such as an intake manifold on the other side, and a relief hole that releases fuel by displacement of the diaphragm. It has an adjustment valve made of a valve body that provides relief. However, this regulating valve has a configuration in which the outer periphery of the diaphragm is clamped by the body, and therefore the body must be provided with a large diameter flange portion for clamping the diaphragm.
In the end, the disadvantage was that the device itself became larger.

Therefore, the purpose of the present invention is to miniaturize the device itself, and for this purpose, the present invention has a fuel chamber that is slidably disposed within the body and communicates with the fuel inlet on one side of the body. A movable body forming a negative pressure chamber communicating with a negative pressure source on the side, an outer circumferential groove provided on the outer circumference of the movable body, a lip disposed in the outer circumferential groove and abutting on the inner circumference of the body,
A cup seal that keeps the fuel chamber and negative pressure chamber airtight.
The valve body is provided with a valve body that controls communication between the fuel inlet and the relief hole according to the movement of the movable body. Therefore, the cup seal that keeps the fuel chamber and the negative pressure chamber airtight can be fitted into an outer circumferential groove provided on the outer circumference of the movable body, and a flange that clamps the outer circumference of the diaphragm can be arranged as in the conventional diaphragm type. Since there is no need to install the device, the device itself does not become larger.

As mentioned above, the present invention only needs to fit the cup seal into the outer circumferential groove provided on the outer circumference of the movable body, so there is no need to clamp the outer circumference of the diaphragm as in the conventional case, and the assembly is simple and practical. It has the above effect.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the drawing, a fuel delivery pipe 10 has a fuel passage 1 therein which supplies fuel from a fuel pump to a fuel injector of an electronic fuel injection system.
1, and this passage 11 connects to the joint 1 via a regulating valve and seals 12 and 13, which will be described later.
4. Connected to the fuel tank via a passage 17 formed in a member 16 that holds the pipe 15. At the open end of the delivery pipe 10, the pipe 10
The adjustment valve 20 is fitted into the inner circumferential shoulder 18 of the valve via an O-ring 19.

The regulating valve 20 includes a cylindrical body 23 having a fuel inlet 21 connected to the fuel passage 11 and a relief hole 22 leading to the passage 17, a movable body 24 slidably disposed within the body 23, and a movable body 24. A lip 26 is fitted into an outer circumferential groove 25 formed in the body 24 and comes into contact with the inner circumferential surface of the body 23.
A cup seal 29 and a movable body 24 are shown, which airtightly partition a fuel chamber 27 that connects the inside of the body 23 with the inlet 21 and a negative pressure chamber 28 that connects with a negative pressure source such as an intake manifold of the vehicle. A spring 30 biasing rightward is actuated in accordance with the fluctuation of the movable body 24 and comes into contact with a seat 31 formed on the body 23 or separates from the seat 31 to control communication between the inlet 21 and the relief hole 22. It has a poppet-type valve body 32 and a spring 33 that biases the valve body 32 in a direction away from the seat 31.
The biasing force of the spring 30 is sufficiently larger than the biasing force of the spring 33, and therefore, under normal conditions, the movable body 24 is in the illustrated position and the valve body 32 is in the closed position in contact with the seat 31. The movable body 24 has an outer peripheral extension portion 34
The extending portion 34 functions as a guide member for sliding movement within the body 23 and also prevents the cup seal 29 from tilting.

Retainer 35 that receives the end of spring 30
The arrangement position of the spring 30 is adjusted by moving back and forth an adjustment screw 37 that is screwed into a screw member 36 fixed to the body 23, and thereby the biasing force of the spring 30 is adjusted as desired. The regulating valve 20 is held in the illustrated position where its body 23 abuts the shoulder 18 by a spring member 38 disposed in the left recess of the screw member 36 . This spring member 38 also has the function of preventing welding chips from entering the negative pressure chamber 28 when the cover 39 that closes the open end of the delivery pipe 10 is pulse-welded to the pipe 10.
A pipe 40 connected to a negative pressure source is fixed to the cover 39, and this pipe 40 has a passage 41 formed in the spring member 38 and a passage 4 formed in the screw member 36.
2 to the negative pressure chamber 28 described above.

Regulating valve 2 having the above-mentioned parts in the body 23
0 is formed into a so-called capsule shape and need only be fitted into the open end of the delivery pipe 10. Therefore, no special flange or hub is required for its attachment, and no piping is required. Furthermore, the cup seal 29 only needs to be fitted into the outer circumferential groove 25 of the movable body 24 and does not require a flange for attachment, so the device itself does not become larger.

In the fuel pressure regulating valve device described above, the movable body 24 having the cup seal 29 is
0 to the right in the figure, and is biased to the left by the negative pressure value in the negative pressure chamber 28, into which negative pressure is introduced according to the operating state of the vehicle, and the fuel pressure in the fuel chamber 27. Forced. Therefore, when the negative pressure value in the negative pressure chamber 28 is relatively small, the movable body is moved to the left in the figure by the relatively high fuel pressure, and the negative pressure value in the negative pressure chamber 28 is relatively high. At this time, the movable body is moved to the left in the figure by relatively low fuel pressure, and following this movement of the movable body, the valve body 32, which is biased by the spring 33, is separated from the seat 31, and the fuel Entrance 2
1 into the relief hole 22, the fuel pressure is reduced. When the fuel pressure decreases, the movable body 24 moves to the right in the figure by the spring 30, and accordingly, the valve body 32 is urged to come into contact with the seat 31, cutting off communication between the inlet 21 and the relief hole 22. do. Thereafter, by repeating such operations, the fuel pressure is adjusted to a desired value according to the negative pressure value in the negative pressure chamber 28.

[Brief explanation of drawings]

The drawing is a sectional view showing an embodiment of the fuel pressure regulating device of the present invention. 10...Fuel delivery pipe, 20...Adjusting valve, 21...Fuel inlet, 22...Relief hole, 2
3...Body, 24...Movable body, 27...Fuel chamber, 28...Negative pressure chamber, 29...Cup seal, 3
0... Spring, 32... Valve body.

Claims (1)

[Scope of utility model registration request] a body, a fuel inlet and a fuel relief hole formed in the body, a fuel chamber slidably disposed within the body and communicating with the fuel inlet on one side and a negative pressure source on the other side; a movable body that forms a negative pressure chamber, an outer circumferential groove provided on the outer circumference of the movable body, a lip disposed in the outer circumferential groove and abutting on the inner circumference of the body, and a A fuel tank comprising: a cup seal that keeps the chamber airtight; a valve body that controls communication between the fuel inlet and the relief hole according to movement of the movable body; and a spring that biases the movable body in one direction. Pressure regulating valve device.