JP2003148263A - Fuel pressure control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel pressure control valve capable of effectively reducing the generation of noise with a simple structure. SOLUTION: This fuel pressure control valve contains a housing 10, a fuel storage chamber 16 containing a valve seat member 18, a diaphragm 22, a valve member 26 and an energizing means 28. The fuel pressure control valve is also provided with flow speed and flow quantity restricting means 21 and 26a for reducing either of the flow quantity and the flow speed of the fuel inside a valve port 19 than that of other parts in a part in the circumferential direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pressure control valve arranged in a fuel supply system for a vehicle.

[0002]

2. Description of the Related Art As shown in FIG. 7, in a recent vehicle fuel supply system, a fuel pressure control valve 80 has a fuel tank 71.
It is disposed inside and is connected to the discharge port 72 a of the fuel pump 72. The fuel discharged from the fuel pump 72 is cleaned of foreign matters in the fuel filter 73, and the fuel supply pipe 74
It is supplied from a to the distribution pipe 74b. At this time, the pressure of the fuel discharged from the fuel pump 72 is controlled by the fuel pressure control valve 80.
Is adjusted by. The fuel whose pressure is adjusted is the throttle valve 75.
According to the opening of the intake manifold 76, the air is injected toward the intake valve 78 through the distribution pipe 74b and the fuel injection valve (injector) 77 together with the air. Excess fuel generated by the pressure adjustment of the fuel pressure control valve 80 is returned to the fuel tank 71 from the discharge pipe 79.

As shown in FIG. 8, the housing 83 of the fuel injection valve 80 has a fuel supply port 81 and a fuel discharge port 82, and the fuel storage chamber 86 is a valve seat member having a valve port 84a and a valve seat 85 formed therein. Including 84. The diaphragm 87 is held by the housing 83 and is displaced according to the pressure of the fuel in the fuel storage chamber 86.

The valve member 88 is integrated with the diaphragm 87 and comes into close contact with or separates from the valve seat 85 depending on whether the fuel pressure in the fuel storage chamber 86 is higher or lower than a predetermined value.
The compression coil spring 89 urges the valve member 88 in a direction in which the valve member 88 is in close contact with the valve seat 85. Here, since the lift amount of the valve member 88 is small (about 0.2 mm), due to the pressure difference between the chamber 91 and the fuel storage chamber 86, the fuel flows from each portion in the circumferential direction of the gap toward the center of the valve opening 84a. And flow in vigorously.

As a result, in the vicinity of the inner peripheral surface of the valve seat member 84 which defines the valve opening 84a, the fuel flow is separated from the inner peripheral surface to generate a negative pressure, and this negative pressure causes vapor (air bubbles). Occur. When the fuel flows through the negative pressure portion in the fuel discharge port 82, the vapor expands and bursts, causing abnormal noise. Further, a pressure wave is generated due to the rupture of bubbles, and
8 may vibrate and a resonance sound may be generated.

While the automobile is running, the amount of fuel consumption changes every moment according to the driving state, and the amount of negative pressure and the amount of vapor, that is, the amount of noise generated near the lower end surface of the valve seat member 84 are also instant. Change. Noise is especially disturbing when the engine is idle. In the idle state, the fuel pump 72 discharges a fixed amount of fuel, but the fuel consumption in the engine is small, and most of the fuel is returned from the fuel pressure adjusting valve 80 to the fuel tank 71. As a result, the negative pressure increases and the amount of vapor generated increases.
This is because the noise level will also increase.

In recent automobiles, quietness is emphasized, and as quietness advances, noise generated by the fuel pressure control valve 80 becomes a problem. However, the above-mentioned conventional example is not provided with a positive means for preventing noise.

As another conventional example, for example, Japanese Patent Laid-Open No. 2000-
There is a pressure control valve disclosed in Japanese Patent No. 1046421.
In this conventional example, as shown in FIG.
And a housing 103 having a fuel discharge port 102, and a valve port 1 communicating with the fuel supply port 101 and the fuel discharge port 102.
Fuel storage chamber 10 including a valve seat member 106 in which 05 is formed.
7 and the fuel storage chamber 10 held by the housing 103.
Diaphragm 108 which is displaced according to the pressure of the fuel inside 7.
And the fuel storage chamber 106 integrated with the diaphragm 108.
A valve seat member 110 that opens the valve opening 105 when the pressure of the fuel inside exceeds a predetermined value, a compression coil spring 112 that urges the valve member 110 in the direction of closely contacting the valve seat, and a fuel discharge port 102. A return pipe 114 connected to return excess fuel to the fuel tank 120.

[0009]

In the pressure control valve shown in FIG. 10, the return pipe 11 is provided to reduce noise.
4, an inlet 116 is provided, and a pressure control valve is set in the fuel tank 120 maintained at atmospheric pressure, and the return pipe 1
By introducing the atmosphere in the fuel tank 120 into 14, the generation of negative pressure is suppressed.

That is, according to the above-mentioned publication, the inlet 11
The diameter of 6 can prevent a large amount of fuel flowing in the return pipe 114 from leaking into the fuel tank 120 in consideration of the surface tension and the flow velocity of the fuel, and the atmosphere in the fuel tank 120 can be changed to the return pipe 114. It is set to a size that can be introduced,
a. In addition, when excess fuel flows through the return pipe 114,
It is stated that the fuel on the side with a small curvature in the curved portion 115 moves to the outside by the centrifugal force, and the pressure in the small curvature portion decreases, so that the atmosphere in the fuel tank 120 is introduced into the return pipe 114.

However, the size of the inlet 116 and the curvature of the curved portion 115 of the return pipe 114 can be adjusted by the return pipe 11.
It is not always easy to set such that the negative pressure inside the fuel tank 4 is reliably prevented by the atmosphere inside the fuel tank 120. Further, the introduction port 116 is not intended to suppress the generation of vapor to reduce noise.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fuel pressure regulating valve which has a simple structure and can effectively reduce the generation of noise. .

[0013]

The inventor of the present application investigated the pressure in the valve opening 84a of the valve seat member 84 of the conventional example shown in FIG. 8 and as shown in FIG. And valve member 88
In the gap area a between the contact surface 88a and the contact surface 88a, a relatively large negative pressure was obtained, an inner area b thereof was a medium negative pressure, and a central area c was a relatively small negative pressure.

Judging from this, the fuel flowing inward in the radial direction (x direction) from the gap collides at the central portion to form a stagnation P of the flow, and thereafter, at a high flow velocity in the axial direction (y direction). It flows in large quantities. At that time, the inner peripheral surface 84 of the valve opening 84a
It is considered that the fuel in the vicinity of b is caught in the z direction and the negative pressure is generated accordingly. That is, it is considered that the negative pressure is likely to be generated in the vicinity of a large amount of fuel flowing at a high flow velocity.

The present invention is based on the finding that it is effective to prevent the generation of negative pressure by preventing formation of a portion where the flow velocity of fuel is high in the valve opening as much as possible. That is, the present invention is a valve seat member having a housing having a fuel supply port and a fuel discharge port, a valve port for storing fuel and communicating with the fuel supply port and the discharge port, and a valve seat formed on the inlet side of the valve port. And a diaphragm that is held in the housing and is displaced according to the pressure of the fuel in the fuel storage chamber, and that is in close contact with the valve seat while the pressure of the fuel in the fuel storage chamber that is interlocked with the diaphragm is below a predetermined value. When the fuel pressure exceeds the predetermined value, a valve member that separates from the valve seat, and a biasing means that biases the valve member in a direction in which the valve member is in close contact with the valve seat. When separated from the valve seat, there is provided a flow velocity / flow rate suppressing means for slowing the flow velocity of the fuel in the valve opening in one portion in the circumferential direction of the valve opening or for reducing the flow rate in the valve opening as compared with the other portion. To do.

In this fuel pressure control valve, the flow velocity / flow rate suppressing means makes the flow velocity of the fuel in the valve opening slower in one part in the circumferential direction than in the other part, thereby suppressing the generation of negative pressure. The generation of the negative pressure is also suppressed by making the flow rate of the fuel smaller in one part of the valve opening in the circumferential direction than in the other part.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the invention are as follows. <Fuel Pressure Control Valve> The fuel pressure control valve is not particularly limited in shape, size and configuration, and a general-purpose fuel pressure control valve can be adopted.

The housing may have a tubular shape as a whole. One of the fuel supply port and the fuel discharge port may be formed in the axially intermediate portion of the housing in the radial direction, and the other may be formed in the lower end portion of the housing in the axial direction.

The fuel storage chamber is partitioned by the housing,
The fuel supplied from the fuel supply port is stored in the internal space, and the stored fuel is discharged from the fuel discharge port. A valve seat member having a valve port communicating with the fuel supply port and the fuel discharge port is arranged in the fuel storage chamber. The valve seat member may be a cylindrical member arranged and held concentrically with the housing, and the valve seat is formed on the inlet side of the valve port.

The diaphragm is held by the housing and receives the pressure of the fuel in the fuel storage chamber on one surface thereof and the urging force of the urging member on the other surface thereof, and is displaced in the plate thickness direction accordingly. The valve member is integrated with the diaphragm and interlocks with the diaphragm. The integration of the valve member and the diaphragm can be realized by, for example, fitting a spherical member attached to the valve member made of a disc into a recess of a holding member held at the center of the diaphragm so that the valve member can be aligned.

Further, the valve member faces the valve seat member, and while the fuel pressure in the fuel storage chamber is below a predetermined value, the valve member moves due to the deformation of the diaphragm to come into close contact with the valve seat and into the valve opening of the fuel. Inflow is blocked, and when it exceeds a predetermined value, it is separated from the valve seat and allowed to flow into the valve opening. The urging means urges the valve member toward the valve seat member via the diaphragm. It may consist of a compression coil spring and may be arranged on the other side of the diaphragm.

The fuel pressure regulating valve can further include a return pipe for surplus fuel, a chamber on the side opposite to the fuel storage chamber with a diaphragm in between, and the like. The return pipe is connected to the fuel outlet and extends to the fuel tank, and returns excess fuel discharged from the fuel outlet to the fuel tank. The chamber is defined by a part of the housing, the urging means is arranged in the internal space thereof, and a pipe extending to the intake manifold can be connected to the chamber.

The fuel pressure adjusting valve may be arranged inside the fuel tank or outside the fuel tank. <Flow Velocity / Flow Rate Reducing Means> The flow velocity / flow rate suppressing means slows the flow velocity of fuel in a part of the valve opening in the circumferential direction in comparison with the flow velocity of other parts in order to suppress the generation of negative pressure in the valve seat member. Alternatively, the flow rate of the fuel in one portion of the valve opening in the circumferential direction is made smaller than that in the other portions. For that purpose, the size of the gap between the valve seat of the valve seat member and the valve member is made different in the circumferential direction of the valve opening (first type), and the fuel to the valve opening of the valve seat member is changed. Is different in the ease of inflow in the circumferential direction of the valve opening (second type). In the first type, specifically, firstly, the end surface of the valve seat member, which is a tubular member, facing the valve member is formed by an inclined surface that forms a predetermined angle with a plane orthogonal to the axis of the valve seat member. can do. The predetermined angle can be selected in the range of up to about 10 degrees in consideration of the followability of the valve member, the assembling property of the fuel pressure control valve, and the like. Considering the effect of the inclination, the inclination angle is preferably 2 degrees or more. As a result, the size (height) of the gap between the valve seat and the valve member differs between the circumferential portion and the remaining portion of the valve opening, and the fuel flow rate,
The flow rate will be different.

Second, the valve member is held by the biasing means such as a compression coil spring so that the contact surface of the valve member forms a predetermined angle with the axis of the valve member. For that purpose, the contact portion of the compression coil spring with the valve member can be ground or the like so as to form a predetermined angle with respect to the axis of the compression coil spring.
Similar to the first type, the predetermined angle can be selected in the range of 2 to 10 degrees in consideration of the followability of the valve member.

In the above two specific examples, there is no restriction on the relative positional relationship between the large gap portion and the fuel supply port, and it may be on the same side as the fuel supply port, on the opposite side, or at any other position. good. Further, the size of the gap may be changed continuously or stepwise in the circumferential direction of the valve opening. Further, the part of the valve opening in the circumferential direction may be, for example, ½ or ⅓ of the entire circumference. On the other hand, in the second type, specifically, the axis of the valve opening of the valve seat member made of a tubular member can be displaced (eccentric) from the axis of the valve seat member in any radial direction. In this case, it is difficult for fuel to flow into the valve opening on the side where the eccentricity of the valve opening is large,
On the side where the amount of eccentricity is small, the fuel easily flows into the valve opening.

[0026]

EXAMPLES The present invention will be described in detail below based on examples. <First Embodiment> Since the fuel supply device is the same as that shown in FIG. 7, its illustration and description are omitted.

As shown in FIG. 1, the fuel pressure regulating valve includes a housing 10, a fuel storage chamber 16, a valve seat member 18,
Diaphragm 22 and valve member 26, and compression coil spring 2
8 and.

Of these, the housing 10, which is the main body of the fuel pressure regulating valve, is composed of members 11 and 12 and has a generally cylindrical shape, has a fuel supply port 13 and a fuel discharge port 14, and has a fuel storage chamber 16 and The chamber 17 is divided. The fuel supply port 13 is formed in a radial direction at an intermediate portion in the axial direction,
The fuel outlet 14 is formed in the axial direction at one end (lower end) in the axial direction.

A cylindrical valve seat member 18 is provided in the fuel storage chamber 16.
Are arranged and held concentrically with the housing 10, the upper end of which is communicated with the fuel supply port 13, and the lower end thereof is with the fuel discharge port 14.
Has a valve port 19 communicating with the. The valve port 19 has a circular cross section and is formed in the center of the valve seat member 18. A valve seat 21 is formed on the inlet end surface (upper end surface) of the valve opening 19. The valve seat 21 is composed of an inclined surface that forms a predetermined angle (about 2 degrees) with respect to a plane orthogonal to the axial direction of the valve seat member 18, the fuel supply port 13 side is the lowest, and the portion facing the diameter direction is the lowest. It is the highest.

The thin disk-shaped diaphragm 22 is held at its peripheral edge by the housing 10, and a holding member 23 is held at the center thereof. Depending on the magnitude relationship between the force and pressure applied to the upper and lower surfaces, the central portion thereof, that is, the holding member 23.
Is displaced in the thickness direction (vertical direction in FIG. 1).

The disc-shaped valve member 26 has a flat contact surface 26a formed on the lower side thereof, and a ball member 27 is brazed on the upper side thereof. The spherical member 27 is fitted in the spherical recess formed in the holding member 23 and can be aligned by being guided by the recess, whereby the valve member 26 can be swung. Thus, the valve member 26 moves up and down integrally with the diaphragm 22 so as to approach or separate from the valve seat member 18. The valve seat 19 of the valve seat member 18, the contact surface 26a of the valve member 26, and the like constitute flow velocity / flow rate suppressing means.

Thus, the compression coil spring 28 is disposed in the chamber 17 of the housing 10 (formed on the side opposite to the fuel storage chamber 16 with respect to the diaphragm 22), and one end (upper end) of the compression coil spring 28 contacts the ceiling. The other end (lower end) is in contact with the upper surface of the diaphragm 22. As a result, the holding member 23 and the valve member 26 are urged in the direction in which they come into close contact with the valve seat 21.

Next, the function and effect of this embodiment will be described.

The urging force of the compression coil spring 28 is applied to the upper surface of the diaphragm 22, and the fuel pressure of the fuel storage chamber 16 is applied to the lower surface. While the former is larger than the latter, as shown in FIG. 2, the valve member 26 oscillates due to the centering action of the ball member 27, and its contact surface is in close contact with the valve seat 21 of the valve seat member 18. There is.

When the fuel pressure in the fuel storage chamber 16 applied to the lower surface of the diaphragm 22 becomes larger than the biasing force of the compression coil spring 28 applied to the upper surface, the diaphragm 22 and the valve member 26 are pushed upward by the fuel pressure. as a result,
Annular gaps 30 a and 30 b (see FIG. 3) are formed between the contact surface 26 a of the valve member 26 and the valve seat 21.

Here, the contact surface 26a of the valve member 26 is a flat surface, but the valve seat 21 of the valve seat member 18 is an inclined surface. Therefore, as shown in FIG. The height of the gap portion 30a is about 0.4 to 0.2 mm and the opening area is large, and the height of the gap portion 30b on the opposite half side is about 0.2 to 0 mm and the opening area is small. As a result, a larger amount of fuel flows into the valve opening 19 from the gap portion 30a than in the gap portion 30b. In addition, fuel valve 1
The total inflow amount to 9 is the same as the conventional example.

At this time, the pressure in each part in the valve port 19 was examined. As is clear from FIG. 4 showing the result, a moderate negative pressure is generated in the narrower gap portion 30b as indicated by d, and a relatively small negative pressure is generated in the wider gap portion 30a as indicated by e. occured. Judging from this, the fuel flows as shown by the arrow m on the side of the wide gap portion 30a, the flow rate of the fuel is larger than that of the conventional example of FIG. 7 and the flow velocity is slower than that of the conventional example. it is conceivable that. On the other hand, in the narrow gap portion 30b, the fuel flows as shown by the arrow n, and the fuel flow velocity is faster than that of the above-mentioned conventional example,
It is considered that the flow rate is lower than that of the conventional example.

As described above, according to the first embodiment, the valve seat 2
1 is formed by an inclined surface, so that the valve opening 1
The generation of negative pressure in 9 can be suppressed. <Second Embodiment> FIGS. 4A and 4B show a second embodiment of the present invention. In this embodiment, the valve seat member 35 and the compression coil spring 40 are different from the above-mentioned embodiment, and the other structures are the same. Therefore, the same numbers are given to the same components to omit the description, and different components will be mainly described.

The valve seat 37 formed on the inlet side of the valve opening 36 of the valve seat member 35 is a flat surface orthogonal to the axial direction of the valve seat member 35.

The compression coil spring 40 has a spiral body portion 4.
1, a ring portion 42 on one end side thereof, and a ring portion 43 on the other end side thereof. The ring portion 42 on the one end side is in contact with the ceiling portion of the housing 10. Ring part 4 at the other end
3 is a seating surface 43 which is ground by a grindstone and is an inclined surface that makes a predetermined angle (about 2 degrees) with a plane orthogonal to the axial direction thereof.
a is formed.

When the diaphragm 22 and the valve member 26 are pushed upward by the fuel pressure during operation of this fuel pressure regulating valve, annular gaps 44a and 44b are formed between the contact surface 26A of the valve member 26 and the valve seat 37. To be done.

Here, since the seating surface 43a of the ring portion 43 at the lower end of the compression coil spring 40 is an inclined surface, even if the compression coil spring 40 is uniformly deformed in the circumferential direction, the configuration shown in FIG.
As shown in (a), the contact surface 26a of the valve member 26 is high on the fuel supply port 13 side and low on the opposite side. This allows
The height of the semicircular gap portion 44a on the fuel supply port 13 side, that is, the opening area is larger than the size of the semicircular gap portion 44b on the opposite side.

As a result, a larger amount of fuel flows into the valve port 36 from the gap portion 44a than in the gap portion 44b on the opposite side, and the flow velocity becomes slower at the inner peripheral surface 38a on the fuel supply port 13 side, and that much. The occurrence of negative pressure is reduced. On the other hand, the flow rate decreases on the opposite inner peripheral surface 38b, and the negative pressure is reduced accordingly.

According to the second embodiment, the compression coil spring 40
It is possible to suppress the generation of negative pressure in the valve port 36 by a simple device such that the seating surface 43a of the ring portion 43 is formed as an inclined surface. <Modifications> Hereinafter, modifications of the valve seat member and the valve member in the above embodiment will be described.

As shown in FIG. 6, the valve seat member 60 is made of a cylindrical member, and the valve opening 61 having a circular cross section is formed eccentrically with the outer peripheral surface. Therefore, the distance from the outer peripheral surface to the inner peripheral surface 63a of the valve opening 61 is short on the fuel supply port 13 side, and the distance from the outer peripheral surface to the inner peripheral surface 63b of the valve opening 61 is long on the opposite side. The valve seat 62 is formed by a flat surface orthogonal to the axial direction of the valve seat member 60.

On the other hand, the valve member 65 is made of a disc member, and its axis is coaxial with the axis of the valve seat member 60.

When the valve member 65 is separated from the valve seat member 60, the gap (height) of the gap formed between them is the same in the gap portion 66a on the fuel supply port 13 side and the gap portion 66b on the opposite side. is there. However, on the side where the distance between the inner peripheral surface 63a and the outer peripheral surface of the valve opening 61 is short, the fuel is likely to flow into the valve opening 61, so the flow velocity is slowed and negative pressure generation is suppressed. on the other hand,
On the side where the distance between the inner peripheral surface 63b and the outer peripheral surface is long, it is difficult for the fuel to flow into the valve opening 61, so the flow rate is reduced and the generation of negative pressure is suppressed.

[0048]

As described above, according to the fuel pressure control valve of the present invention, the generation of the negative pressure at the valve opening of the valve seat member is effectively suppressed by the flow velocity / flow rate suppressing means having a simple structure. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment (fuel pressure regulating valve) of the present invention.

FIG. 2 is a cross-sectional view of main parts for explaining the operation of the first embodiment.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is an explanatory diagram illustrating the generation of negative pressure and the flow of fuel in the first embodiment.

FIG. 5A is a longitudinal sectional view of an essential part showing a second embodiment of the present invention, and FIG. 5B is a sectional view of an essential part for explaining the operation thereof.

FIG. 6 is an explanatory view of a main part showing a modified example of the above embodiment.

FIG. 7 is an explanatory diagram showing a general fuel supply device.

FIG. 8 is a vertical sectional view showing a first conventional example.

FIG. 9 is an explanatory diagram illustrating the generation of negative pressure and the flow of fuel in the first embodiment.

FIG. 10 is a vertical sectional view showing a second conventional example.

[Explanation of symbols]

10: housing 13: fuel supply port 14: fuel discharge port 18: valve seat member 19: valve port 21: valve seat 22: diaphragm 26: valve member 28: compression coil spring (biasing means) 30a, 30b: gap portion 31a , 31b:
Inner surface

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16K 47/02 F02M 69/00 320J (72) Inventor Takashi Furukawa 1-chome Showa-cho, Kariya city, Aichi stock In the company DENSO (72) Inventor Kazunori Arakawa 11 11 Ozairi, Sowa-machi, Sarushima-gun, Ibaraki Kyosan Denki Co., Ltd. F-term (reference) 3G066 AA01 AB02 BA22 BA37 BA40 CB15 CE13 CE16 3H066 AA01 BA07 BA32 EA01 EA12

Claims (5)

[Claims] 1. A housing having a fuel supply port and a fuel discharge port; and a valve port that stores fuel and communicates with the fuel supply port and the fuel discharge port, and a valve seat is formed on the inlet side of the valve port. A fuel storage chamber including a valve seat member, a diaphragm held by the housing and displaced according to the pressure of the fuel in the fuel storage chamber, and a pressure of the fuel in the fuel storage chamber that is interlocked with the diaphragm and is equal to or less than a predetermined value. Between the valve seat and the valve member that is in close contact with the valve seat when the fuel pressure exceeds the predetermined value, and a biasing means that biases the valve member in the direction of closely contacting the valve seat. In the fuel pressure regulating valve including, when the valve member is separated from the valve seat, the flow velocity of the fuel in the valve opening is slower in one part in the circumferential direction of the valve opening than in the other part, or Flow velocity to reduce flow rate
A fuel pressure regulating valve provided with a flow rate suppressing means. 2. The flow velocity / flow rate suppressing means according to claim 1, wherein the size of the gap between the valve seat of the valve seat member and the valve member is different in the circumferential direction of the valve port. Fuel pressure control valve. 3. The fuel pressure regulating valve according to claim 2, wherein the valve seat member is a tubular member, and the valve seat surface of the valve seat member is an inclined surface that forms a predetermined angle with a plane orthogonal to the axis. 4. The biasing means is composed of a compression coil, and the valve seat member is held by the compression coil spring so that the contact surface with the valve seat makes a predetermined angle with the axis when the valve is open. 2. The fuel pressure regulating valve described in 2. 5. The fuel pressure regulating valve according to claim 4, wherein a seating portion of the compression coil spring on the valve member is processed so as to form a predetermined angle with respect to an axis of the compression coil spring.