JPH0219578Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a pressure regulating valve, and more particularly to a pressure regulating valve for maintaining constant fuel pressure in a fuel injection device of an internal combustion engine.

<Prior Art> In a fuel injection device for an internal combustion engine, fuel in a fuel tank is pressurized by an electromagnetic pump or the like, and the fuel is injected from a fuel injection valve into an intake passage or a combustion chamber of the internal combustion engine via a fuel supply passage. It's getting old. In this case, in order to obtain a desired fuel injection amount, it is necessary to control the pressure within the fuel supply passage with high precision. Therefore, a pressure regulating valve is used to release the pressure in the fuel supply passage to the fuel tank side as necessary to keep the pressure in the fuel supply passage constant.

Conventionally, such a pressure regulating valve includes a first cavity that communicates with an intake passage of an internal combustion engine and forms a negative pressure chamber, and a pressure chamber that has an inlet and an outlet that communicate with a fuel supply passage and a fuel return passage, respectively. a casing partitioned by a diaphragm, a pressure regulating spring located within the negative pressure chamber and urging the diaphragm toward the pressure chamber, and a valve support attached to the center of the diaphragm. The valve body has a valve body supported by the valve support, and a valve seat provided in the pressure chamber. In this case, it is preferable that the contact between the valve body and the valve seat is always correct, and that uneven contact is avoided as much as possible when the valve is closed and opened. However, it has not always been possible to obtain a suitable valve contact due to dimensional errors in each component and bias in the biasing force of the pressure regulating spring.

<Problems to be solved by the invention> In view of these drawbacks of the prior art, the main purpose of the present invention is to create a pressure regulating valve that has a simple structure and can always maintain proper valve contact. It is about providing.

The second purpose of the present invention is to provide a pressure regulating valve that can automatically keep the valve body parallel to the valve seat. The object is to provide a casing which is divided by a diaphragm into a first cavity and a second cavity having an inlet and an outlet for the fluid to be pressure regulated; a pressure regulating spring biasing toward the second empty chamber; a valve support attached to the center of the diaphragm; a valve body supported by the valve support; In a pressure regulating valve having a valve seat that cooperates with the valve body, a depression is provided in the center portion of the valve support on the side of the second cavity, and the outer periphery of the depression is provided with a depression. A claw-like projection is provided, and the valve body is held tiltably by a ball resiliently supported within the recess by a compression coil spring and an inner surface of the claw-like projection, and the outer periphery of the valve body The surface is partially spherical with a radius of curvature larger than the sphere, and the inner surface of the claw-like projection is partially spherical with a radius of curvature not smaller than the outer peripheral surface of the valve body. This is achieved by providing a pressure regulating valve that

In particular, when the ball and the valve body are in contact with each other,
Preferably, the outer surface of the sphere and the outer peripheral surface of the valve body have a common center of curvature.

<Operation> According to the present invention, the disc-shaped valve body is held between the resiliently supported ball and the claw-like projection, and the outer surface of the ball, the outer peripheral surface of the valve body, and the inner surface of the claw-like projection are held together. By setting the radius of curvature of the side surface in an appropriate relationship, the valve body can properly tilt relative to the ball depending on the contact with the valve seat, and the gap between the valve body and the claw-like process can be adjusted. The frictional force makes it possible to maintain a position where the valve body can be brought into proper contact with the valve seat at all times. In particular, when the ball and the valve body are in contact with each other, by making the center of curvature of the outer surface of the ball and the outer peripheral surface of the valve body common, the center of the ball and the center of tilt of the valve body coincide with each other. Therefore, the valve body can be tilted without changing the amount of deflection of the coil spring that elastically supports the ball.

<Embodiments> The present invention will now be described in detail with reference to specific embodiments with reference to the accompanying drawings.

1 to 2 show an embodiment of a pressure regulating valve based on the present invention. Lower casing 1
is provided with a fuel inlet 3 to be connected to a line through which pressurized fuel flows and a fuel outlet pipe 5 to be connected to a line returning to the fuel tank.
The upper casing 2 is provided with a negative pressure inlet 6 communicating with an intake passage of the internal combustion engine. These two casings 1 and 2 sandwich the diaphragm 7 between them and are fixed to each other by caulking.

The diaphragm 7 divides the cavity defined within the casing into a negative pressure chamber 8 and a pressure chamber 9. At the center of the diaphragm 7 is a valve support 10.
is attached by a retainer 11, and a compression coil spring 12 interposed between the retainer and the upper wall surface of the negative pressure chamber 8 causes the valve support body 10 to move into the pressure chamber 9.
is biased downward toward the side of When the casing 2 is caulked, the protrusion 10a having the male thread groove on the upper surface of the valve support body 10 is provided on the rod introduced from the negative pressure introduction port 6, and is screwed into the female thread groove.
This is for positioning the valve support body 10.

A depression 13 having a conical support surface is formed in the center of the valve support 10 on the pressure chamber 9 side.
A claw-like projection 17 having a partially spherical inner surface is provided on the outer periphery of the recess so as to curve inward. The claw-like protrusions may be a continuous one that surrounds the entire recess 13, or two or more circumferentially separated claw-like protrusions provided at equal intervals along the outer periphery of the recess 13.

Furthermore, a compression coil spring 14 and a ball 1 are placed in the recess 13.
5 and the valve body 16 are held in this order. That is, a disk-shaped valve body 16 is held between a ball 15 resiliently supported by a coil spring 14 inserted into the bottom of the recess 13 and a claw-like projection 17. The inner surface of the claw-like projection 17 has a partially spherical surface, and the outer peripheral surface of the valve body 16 also has a partially spherical surface that is substantially complementary to this partially spherical surface.

Here, the outer peripheral surface of the valve body 16 is the radius of curvature of the sphere 15.
It has a partially spherical shape with a radius of curvature _R2 larger than _R1 , and the inner surface of the claw-like projection 17 is connected to the valve body 16.
The radius of curvature of the outer peripheral surface of R is not smaller than ₂
It forms a partial spherical surface with R ₃ . Also, ball 1
5 and the valve body 16 are in contact with each other, it is preferable that the outer surface of the sphere and the outer peripheral surface of the valve body have a common center of curvature. By doing so, the center of the ball 15 and the center of tilting of the valve body 16 coincide with each other, so that the valve body 16 can be tilted without moving the position of the ball 15. Therefore, the pressing force of the compression coil spring 14 is constant regardless of the tilt angle of the valve body 16, so that no unreasonable force is applied when the valve body 16 comes into contact with the valve seat 18.

As clearly shown in FIG. 1, the fluid inlet 3 forms a flange joint with a flange 4, and an O-ring 19 for ensuring liquid tightness is installed in an annular groove 4a cut into the flange. It is inserted. The fluid outlet pipe 5 is press-fitted into the fitting hole 1a of the casing 1 with an enlarged diameter portion 5a provided in advance. A countersink surface 20 is formed at the opening of the fitting hole 1a, and an O-ring 2 is inserted into the annular space defined by the countersink surface 20 and the enlarged diameter portion 5a of the outlet pipe 5.
1 is clamped to ensure the liquid tightness of the outlet pipe 5. Further, a rough surface is formed on the outer periphery of the fitting end 5b of the outlet pipe 5 by knurling or serration processing, and the fitting end 5b is formed into the fitting hole 1a.
has become firmly held.

Next, the operating procedure of the pressure regulating valve of this embodiment will be explained.

The pressurized fuel is introduced into the pressure chamber 9 through the fuel inlet 3 from a fuel passage (not shown). When the pressure in the pressure chamber 9 exceeds a certain pressure value determined by the spring force of the coil spring 12 and the negative pressure in the negative pressure chamber 8, the diaphragm 7 is displaced toward the negative pressure chamber 8, and the valve body 16 and the valve seat 18 are separated from each other, and the fuel in the pressure chamber 9 is returned from the fuel outlet 5 to a fuel tank (not shown), resulting in a drop in the pressure of the fuel in the fuel supply passage.

In this way or for other reasons, the pressure chamber 9
When the internal pressure becomes lower than the set pressure value, the diaphragm 7 is again displaced toward the pressure chamber 9, the valve body 16 comes into contact with the valve seat 18, and communication between the pressure chamber 9 and the fuel outlet 5 is cut off. .

<Effects> According to the present invention, the valve body 16 rolls on the ball 15 and the inner surface of the claw-like protrusion 17 and the outer peripheral surface of the valve body 16 slide against each other, so that the valve body 16 becomes a valve. A suitable tilting movement is carried out on the seat 18 to ensure correct seating of the valve.

Moreover, once the valve body 16 has taken this position,
Even when separated from the valve seat 18 and after completely separated from the valve seat 5, the valve body is held in the same position by the frictional force between its outer peripheral surface and the inner surface of the claw-like protrusion 17. The valve seat 16 does not tilt unnecessarily and always comes into contact with and away from the valve seat 18 with the correct contact, so that an appropriate valve opening/closing operation can be performed.
As a result, in both valve opening and closing operations, the valve body 1
6 and the valve seat 18 do not make uneven contact, excellent pressure control characteristics can be obtained, and the degree of occurrence of hysteresis is also small.

[Brief explanation of the drawing]

FIG. 1 is a front view of a pressure regulating valve based on the present invention. FIG. 2 is a longitudinal sectional view taken along the - line in FIG. 1. FIG. 3 is an enlarged longitudinal sectional view showing the main part of FIG. 2. 1...lower casing, 1a...fitting hole, 2...
... Upper casing, 3 ... Inlet, 4 ... Flange, 4a ... Annular groove, 5 ... Outlet pipe, 5a ... Expanded diameter part, 5b ... End, 6 ... Negative pressure inlet, 7 ...
Diaphragm, 8... Negative pressure chamber, 9... Pressure chamber, 1
0... Valve holding body, 10a... Protrusion, 11... Retainer, 12... Coil spring, 13... Recess, 14
... Compression coil spring, 15 ... Ball, 16 ... Valve body, 17 ... Claw-like projection, 18 ... Valve seat, 19 ...
O-ring, 20...spot face, 21...O-ring.

Claims (1)

[Claims for Utility Model Registration] A casing divided by a diaphragm into a first cavity and a second cavity having an inlet and an outlet for a fluid to be pressure regulated; a pressure regulating spring that urges the diaphragm toward the second chamber; a valve support attached to the center of the diaphragm; a valve body supported by the valve support; In a pressure regulating valve having an empty chamber and a valve seat cooperating with the valve body, a recess is provided in a central portion of the valve support on the side of the second empty chamber, and the recess is provided with a recess. A claw-like projection is provided on the outer periphery of the valve body, and the valve body is held tiltably by a ball elastically supported within the recess by a compression coil spring and an inner surface of the claw-like projection. The outer peripheral surface of the body has a partially spherical shape with a radius of curvature larger than the sphere, and the inner surface of the claw-like projection has a partially spherical shape with a radius of curvature not smaller than the outer peripheral surface of the valve body, and A pressure regulating valve characterized in that, in a state in which the ball and the valve body are in contact with each other, an outer surface of the ball and an outer circumferential surface of the valve body have a common center of curvature.