JP2000055233A - Pressure control valve - Google Patents

Abstract

(57) [Summary] [Objective] To improve the seating of the pressure control valve and reduce the manufacturing cost. [Structure] Fuel chamber 4 with diaphragm 3 and housing 1
Is formed, a spring chamber 5 is formed by the diaphragm 3 and the diaphragm cover 2, and a fuel inflow path 6 is formed in the fuel chamber 4.
And the valve seat hole 7 are opened. An annular valve portion 3A for opening and closing the valve seat hole 7 is formed integrally with the diaphragm 3. The retainer 8 is disposed on the spring chamber side facing surface 3C of the diaphragm 3, and the cylindrical outer wall 8B of the retainer 8 is provided.
Is slidably guided and arranged on the cylindrical side surface 2A of the diaphragm cover 2. One end 9 of the spring 9 in the spring chamber 5
A is locked to the diaphragm cover 2, and the other end 9B is locked to the retainer 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control valve used in a fuel injection device of an internal combustion engine, and the pressure control valve controls the amount of fuel injected from the fuel injection valve by an ECU.
This is a pressure adjusting device that keeps the fuel pressure in the fuel distribution pipe at a predetermined constant pressure in order to make it proportional to the energizing time output from the fuel supply pipe.

[0002]

2. Description of the Related Art A first example of a conventional pressure control valve is shown in FIG. According to this, the diaphragm 22 is sandwiched between the housing 20 and the diaphragm cover 21, the fuel chamber 23 is formed in the housing 20, and the spring chamber 24 is formed in the diaphragm cover 21. And
A fuel inflow hole 25 and a fuel discharge hole 26 are opened in the fuel chamber 23, and the fuel discharge hole 26 is formed in the valve seat hole 2.
6A opens into the fuel chamber 23. V is a valve body formed integrally with the diaphragm 22 and comprises the following. A thin cylindrical portion 27A is recessed at a position below the valve seat V facing the valve seat hole 26A, and a conical concave portion 27B and a spring receiving concave portion 27C having a small diameter are continuously provided upward from the bottom of the thin cylindrical portion 27A. You. Then, a spring 28, a ball 29, and a plate-shaped valve portion 30 are sequentially arranged from the opening of the thin-walled tube portion 27A, and the tip of the thin-walled tube portion 27A is bent and caulked toward the outer periphery of the plate-shaped valve portion 30. According to the above, the plate-shaped valve portion 30 is arranged at the tip of the valve body V, and the plate-shaped valve portion 30 is urged by the spring force of the spring 28 via the ball 29.

[0003] The valve element V is provided in a spring chamber 24.
The diaphragm 22 is disposed so as to sandwich the diaphragm 22 together with the cup-shaped retainer 31 disposed therein, and the upper end thereof is caulked toward the retainer 31. Accordingly, the retainer 31 is fixedly arranged on the spring chamber side facing surface 22A of the diaphragm 22, and the plate-shaped valve portion 30 is arranged on the fuel chamber side facing surface 22B. A spring 32 is provided in the spring chamber 24.
The one end 32A of the spring 32
Is locked to the diaphragm cover 21, and the other end 32 </ b> B is locked to the retainer 31.

FIG. 6 shows another conventional example. Reference numeral 40 denotes a diaphragm disposed between the housing 20 and the diaphragm cover 21, and an annular valve portion 40A that opens a valve seat hole 26A is integrally molded at a central portion thereof. Reference numeral 41 denotes a cup-shaped retainer which is placed in the spring chamber 24 and placed on the spring chamber side facing side surface 40B of the diaphragm 40. Reference numeral 42 denotes a spring contracted in the spring chamber 24. One end 42A of the spring 42 is locked to the diaphragm cover 21 and the other end 42B is locked to the retainer 41. In particular, the cross section of the spring 42 is formed in a square shape. The same components as those of the first conventional example have the same reference numerals.

[0005]

According to the first prior art, the cross-sectional shape of the spring 32 contracted in the spring chamber 24 is circular, and when the spring 32 is compressed, the lateral rigidity is reduced. The force is weak, and an oblique force acts on the retainer 31. On the other hand, the spring force of the spring 28 is applied via the ball 29 to the back of the plate-shaped valve portion 30 that opens and closes the valve seat hole 26A and is held in a floating state. Even when a force is applied, the plate-shaped valve portion 30 is automatically displaced along the valve seat hole 26A and abuts in a flat state, so that the valve seat hole 26A can be reliably closed. However, according to the first example of the related art, since the floating action is provided to the valve body V,
The plate-shaped valve portion 30, the ball 29, and the spring 28 need to be specially prepared. In addition, it is necessary to sequentially assemble the components into the valve body V, and then caulk the tip of the thin-walled cylindrical portion 27A. Therefore, the number of parts and the number of assembling steps increase, and the manufacturing cost cannot be reduced.

Further, according to the second conventional example, since the cross-sectional shape of the coil-shaped spring 42 is square, the lateral rigidity of the spring 42 when the spring 42 is compressed can be increased. By retainer 41
In the vertical direction. However, the use of such a rectangular spring 42 is particularly expensive in manufacturing the rectangular wire rod, and cannot provide an inexpensive pressure control valve.

The pressure control valve according to the present invention has been made in view of such a problem, and an object of the present invention is to provide a pressure control valve which can reduce manufacturing costs and has excellent seating properties.

[0008]

In order to achieve the above object, a pressure control valve according to the present invention is divided into a fuel chamber and a spring chamber by a diaphragm disposed between a housing and a diaphragm cover. In the chamber, a fuel inflow path is opened and a valve seat hole is opened and closed by an annular valve portion integrally formed with the diaphragm. On the other hand, a spring for pressing the diaphragm toward the fuel chamber is contracted in the spring chamber. In the pressure control valve, a bottomed tubular retainer is disposed on the spring chamber side facing surface of the diaphragm, and the tubular outer wall of the retainer is moved in the opening and closing movement direction of the annular valve portion with respect to the cylindrical side surface of the diaphragm cover. The first state is that the spring is slidably guided along, one end of the spring is locked on the diaphragm cover, and the other end of the spring is locked on the retainer. And it features.

According to the present invention, in addition to the first feature, a plurality of guide projections are provided on the cylindrical outer wall of the retainer along the opening and closing movement direction of the annular valve portion, and the retainer is connected via the guide projections. A second feature is that the diaphragm cover is slidably guided on the cylindrical side surface of the diaphragm cover.

Further, the present invention has a third feature in that the retainer is formed of a synthetic resin material in addition to the first and second features.

[0011]

According to the first feature, the other end of the spring contracted into the spring chamber is locked by a retainer guided and arranged along the cylindrical side surface of the diaphragm cover. Therefore, the retainer can always apply a spring force to the diaphragm in a flat state, so that the sheet hole can be properly closed. Further, a spring having a round cross section can be employed without any particular limitation on the cross section of the spring, and there is no need to provide a floating function in the valve section, so that an inexpensive pressure control valve can be provided.

According to the second feature, since the retainer is slidably guided on the cylindrical side surface of the diaphragm cover via the plurality of guide projections, the sliding resistance between the retainer and the cylindrical side surface can be reduced, and pressure control can be performed. And responsiveness can be improved.

Further, according to the third feature, the sliding resistance of the retainer can be further reduced, and the pressure controllability and responsiveness can be further improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a pressure control valve according to the present invention will be described below with reference to FIGS. Reference numeral 1 denotes a cylindrical housing that opens upward, 2 denotes a cylindrical diaphragm cover that opens downward, and a diaphragm 3 is arranged and sandwiched between both openings. According to the above, the fuel chamber 4 is formed by the diaphragm 3 and the housing 1, and the spring chamber 5 is separately formed by the diaphragm 3 and the diaphragm cover 2. In the fuel chamber 4,
The fuel inflow passage 6 opens and the valve seat hole 7 opens. (The downstream of the valve seat hole 7 corresponds to a fuel outflow passage.) The valve seat hole 7 is formed in a cylindrical portion protruding into the fuel chamber 4. It is formed in a planar shape.

On the other hand, an annular valve portion 3A for opening and closing the valve seat hole 7 is integrally formed at the center of the diaphragm 3, and the annular valve portion 3A
Is formed on the fuel chamber side facing surface 3B. Reference numeral 8 denotes a cup-shaped retainer which is located in the spring chamber 5 and faces the spring chamber side facing surface 3C of the diaphragm 3. The retainer 8 has at least a bottom portion 8A facing the annular valve portion 3A.
And a cylindrical outer wall 8B along the opening and closing movement direction XX of the annular valve portion 3A.

The diaphragm cover 2 is formed with a cylindrical side surface 2A toward the lower opening, and the cylindrical outer wall 8B of the retainer 8 extends along the opening and closing movement direction XX of the annular valve portion 3A. When moving, the cylindrical outer wall 8B is movably guided by the cylindrical side surface 2A of the diaphragm cover 2. In other words, the retainer 8 is a cylindrical outer wall 8
B is guided in the vertical direction by the cylindrical side surface 2A of the diaphragm cover 2, and the lateral movement is suppressed. In addition, 8C
Is a ventilation hole penetrating through the bottom of the retainer 8.

Reference numeral 9 denotes a spring contracted in the spring chamber 5, one end 9A of which is locked to the upper end of the diaphragm cover 2 and the other end of which is locked to the bottom of the retainer 8. Then, the spring force of the spring 9 is applied to the diaphragm 3 via the retainer 8 to urge the annular valve portion 3A to close the valve seat hole 7.

When the fuel pressure flowing into the fuel chamber 4 from the fuel inflow passage 6 exceeds a predetermined pressure, the fuel pressure in the fuel chamber 4 pushes the diaphragm 3 upward by the fuel pressure, and the spring 9 The diaphragm 3 is displaced upward until a position where the downward pressing force against the diaphragm 3 due to the spring force is balanced, and according to the displacement of the diaphragm 3, the annular valve portion 3A becomes a flat surface at the tip of the disk portion. Further, the valve seat hole 7 is opened and closed. Therefore, the fuel chamber 4 corresponds to an increase in the fuel pressure in the fuel chamber 4.
Since the fuel pressure in the fuel chamber 4 is released via the valve seat hole 7, the fuel pressure in the fuel chamber 4 can be controlled to a predetermined pressure again.

According to the pressure control valve of the present invention,
The following special effects are exhibited. That is, the spring chamber 5
According to the fact that the cross-sectional shape of the spring 9 contracted into the inside is a round coil spring, when the spring 9 is compressed, the lateral rigidity of the spring 9 is weak,
An oblique pressing force is applied to the retainer 8. Here, in the retainer 8 of the present invention, the cylindrical outer wall 8B of the retainer 8 is slidably guided by the cylindrical side surface 2A of the diaphragm cover 2 along the opening and closing movement direction XX of the annular valve portion 3A. Therefore, even when receiving the pressing force in the oblique direction by the spring 9, the retainer 8 keeps the annular valve portion 3.
There is no inclination with respect to the opening and closing movement direction XX of A.
According to the above, the spring force of the spring 9 can be applied to the annular valve portion 3A in the vertical direction via the bottom surface 8A of the retainer 8, so that the valve seat hole 7 can be reliably closed and held, and the pressure control performance can be improved. An excellent pressure control valve can be provided.

Further, according to the adoption of the retainer 8, a vertical spring force can always be applied to the annular valve portion 3A via the retainer 8, so that a floating action can be achieved as in the first conventional example. This eliminates the need for a plate-shaped valve portion, a ball, and a spring, and does not require the use of a spring having a square cross section as in the second conventional example. According to the above,
The number of parts, the cost of parts, and the number of assembling steps can be reduced, and the manufacturing cost can be significantly reduced.

In addition, since the inclination and the lateral movement of the retainer 8 are suppressed, the retainer 8 and the diaphragm 3
In this case, the durability of the diaphragm using the diaphragm 3 having the plate-shaped portion at the center can be greatly improved.

A second embodiment of the present invention will be described with reference to FIGS. According to this example, a plurality of guide projections 8D are provided on the cylindrical outer wall 8B of the retainer 8 in the first embodiment along the opening / closing movement direction XX of the annular valve portion 3A. The portion 8D is slidably guided on the cylindrical side surface 2A of the diaphragm cover 2.

According to the above, the retainer 8 is provided with the guide projection 8D.
The sliding guide is thereby guided to the cylindrical side surface 2A of the diaphragm cover 2, whereby the sliding resistance between the retainer 8 and the cylindrical side surface 2A can be reduced, the dynamic characteristics of the annular valve portion 3A can be improved, and pressure control can be performed. Performance and pressure responsiveness can be improved.

According to the present invention, the spring chamber 5 is vertically separated by the cylindrical side surface 2A and the bottom of the retainer 8. However, according to the provision of the guide projection 8D, the adjacent guide is provided. Since the ventilation holes 8C are formed between the projections 8D and 8D along the vertical direction, it is not necessary to form holes as special ventilation holes. The number of the guide projections may be appropriately selected as appropriate.

If the retainers are formed of a synthetic resin material, the sliding resistance of the retainer 8 can be further reduced, and the pressure controllability and pressure responsiveness can be further improved. Examples of the synthetic resin material include a resin impregnated with a lubricant such as oil, or a self-lubricating material such as a fluororesin (PTF).
E), polyamide resin (PA), polyacetal resin (POM), polyphenylene sulfide (PPS), and the like.

[0026]

As described above, according to the pressure control valve of the present invention, the bottomed cylindrical retainer is disposed on the surface of the diaphragm facing the spring chamber, and the cylindrical outer wall of the retainer is attached to the diaphragm cover. With respect to the cylindrical side surface of the annular valve portion, the guide was slidably guided along the opening and closing movement direction of the annular valve portion, one end of the spring was locked to the diaphragm cover, and the other end of the spring was locked to the retainer. The fall is all restrained by the retainer, and the spring force of the spring can be applied vertically to the annular valve portion integrally formed with the diaphragm via the retainer. According to the above, there is no need to provide the valve body with a floating mechanism, and it is not necessary to use a special spring such as a square cross section,
It is possible to provide an inexpensive pressure control valve that can reduce the number of parts, the cost of parts, and the number of assembly steps. Further, since the spring force of the spring can be applied to the annular valve portion along the opening and closing movement direction, pressure controllability and responsiveness can be improved. Furthermore, according to the fact that the lateral movement of the retainer is suppressed, in the case where the retainer is directly mounted on the flat diaphragm, the wear of the diaphragm can be greatly reduced, and this structure is particularly effective. It is a target.

A plurality of guide projections are provided on the cylindrical outer wall of the retainer along the opening and closing movement direction of the annular valve portion, and the retainer is slidably guided on the cylindrical side surface of the diaphragm cover via the guide projections. According to this, the sliding resistance between the retainer and the cylindrical side surface can be reduced, which is effective for improving the pressure controllability and the response.

Further, by forming the retainer from a synthetic resin material, the sliding resistance between the retainer and the cylindrical side surface can be further reduced, and the above-mentioned effect can be further enhanced. it can.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a pressure control valve of the present invention.

FIG. 2 is a cross-sectional view taken along line AA of FIG.

FIG. 3 is a longitudinal sectional view showing another embodiment of the pressure control valve of the present invention.

FIG. 4 is a transverse sectional view taken along line BB of FIG. 3; (FIG. 3 corresponds to a cross section taken along line CC of FIG. 4)

FIG. 5 is a longitudinal sectional view showing a first example of a conventional pressure control valve.

FIG. 6 is a longitudinal sectional view showing a second example of a conventional pressure control valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 Diaphragm cover 2A Cylindrical side surface 3 Diaphragm 3A Annular valve part 8 Retainer 8B Cylindrical outer wall 9 Spring

Claims (3)

[Claims] A diaphragm disposed between a housing and a diaphragm cover is divided into a fuel chamber and a spring chamber. A fuel inflow passage is opened in the fuel chamber and an annular valve portion formed integrally with the diaphragm. A pressure control valve that opens and closes a valve seat hole that is opened and closed, and a spring that contracts a spring that presses the diaphragm toward the fuel chamber in the spring chamber. A bottomed cylinder is provided on the spring chamber side facing surface 3C of the diaphragm. And a cylindrical outer wall 8B of the retainer is slidably guided along the opening and closing movement direction XX of the annular valve portion 3A with respect to the cylindrical side surface 2A of the diaphragm cover 2; A pressure adjusting device, wherein one end 9A of the spring is locked to the diaphragm cover 2 and the other end 9B of the spring 9 is locked to the retainer 8. 2. A plurality of guide projections 8D along the opening and closing movement direction XX of the annular valve portion 3A on the cylindrical outer wall 8B of the retainer.
The pressure adjusting device according to claim 1, wherein a retainer 8 is slidably guided on a cylindrical side surface 2A of the diaphragm cover 2 via a guide projection 8D. 3. The pressure adjusting device according to claim 1, wherein the retainer is formed of a synthetic resin material.