JPH0642659A - Pressure regulating valve - Google Patents

Abstract

PURPOSE:To provide a pressure regulating valve which can be smoothly operated while restrains the diametrical displacement of bellows without increasing the mass of a movable part. CONSTITUTION:Bellows 3 are adapted to expand and contract in its axial direction in which a valve is opened and closed, due to a pressure differential between the outside and inside of the bellows 3. The distal end 32 of the bellows 3 opens and closes a valve hole 21 in a stationary valve seat 2. A pressure intake cylinder 13 having its proximal end part is fixed to the main cylinder 11, and is housed in the bellows 3 along the axis of the bellows. Further, the lower end part of the pressure intake cylinder 13 is in slidable contact with the inner peripheral surface of the distal end part 32 of the bellows 3 so as to guide the bellows 3 when the latter is displaced in the axial direction of the bellows 3 while regulating the eccentricity of the bellows 3. It is noted that the bellows 3 may be guided by the inner peripheral surface of the main cylinder 11, and in this case, a passage for introducing fuel is formed in the bellows 3, entirely between the bellows 3 and the main cylinder 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure regulating valve which controls fluid pressure by changing valve opening depending on fluid pressure.

[0002]

2. Description of the Related Art In Japanese Utility Model Publication No. 3-51567, the base end is fixed to a valve body, and the front end expands and contracts in the axial direction by the pressure of a control fluid. In a pressure control valve that opens and closes a (valve hole), a valve guide that extends from the tip of the bellows and is slidably guided in the axial direction by the outer circumference of the plug is provided so that the tip of the bellows, that is, the valve element is eccentric. Is being prevented.

[0003]

However, the bellows type pressure regulating valve described above has the following problems.
First of all, since the valve guide must be additionally installed on the bellows that constitutes the movable part of the valve, the kinetic mass of the movable part increases,
Its high-speed response deteriorates. Further, the valve length is increased by the amount of the valve guide and the plug, which is an obstacle to miniaturization. Further, since the valve guide slides in the controlled fluid such as fuel, cutting chips and dust mixed in the controlled fluid enter between the valve guide and the plug, which hinders sliding of the valve guide. I have something to do.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a pressure regulating valve capable of suppressing the radial displacement of the bellows and smoothly operating without increasing the mass of the movable portion. There is.

[0005]

A pressure regulating valve according to a first aspect of the present invention has a tubular valve body having an internal space into which a fluid is introduced, and a valve hole having a valve hole communicating with the internal space of the valve body. A pressure regulating valve including a fixed valve seat fixed inside the main body, and a cylindrical bellows whose base end is fixed to the valve body and whose central portion expands and contracts and whose front end opens and closes the valve hole. Is fixed to the valve body, and extends inside the bellows along the axial direction of the bellows, and is provided with a guide cylinder portion that slidably contacts the inner surface of the bellows and restricts the eccentricity of the bellows. I am trying.

The pressure regulating valve of the second invention has a cylindrical valve body having an internal space into which a fluid is introduced, and a valve hole communicating with the internal space of the valve body, and is fixed in the valve body. In a pressure regulating valve comprising a fixed valve seat and a bellows whose base end is fixed to the valve body and whose central part expands and contracts and whose tip part opens and closes the valve hole, the bellows are provided on the inner peripheral surface of the valve body. It is characterized in that it is guided so as to be relatively slidable in the axial direction, and a passage is formed between the outer periphery of the bellows and the inner peripheral surface of the valve body for allowing a fluid to flow therethrough in the axial direction.

[0007]

In the pressure regulating valve of both of the above inventions, the bellows expands and contracts in the axial direction, that is, the valve opening / closing direction due to the pressure difference between the inside and outside of the bellows, and the tip of the bellows opens / closes the valve hole of the fixed valve seat.
According to the first aspect of the present invention, the guide tube portion whose base end portion is fixed to the valve body is disposed inside the bellows whose base end portion is fixed to the valve body and expands and contracts in the axial direction of the valve body. The guide tube portion extends inside the bellows along the axial direction of the bellows and comes into sliding contact with the inner surface of the tip end portion of the bellows to prevent the eccentricity of the bellows, that is, the radial deviation thereof.

In the second aspect of the invention, the inner peripheral surface of the valve body guides the tip end portion of the bellows in a relatively slidable manner in the axial direction, and prevents the eccentricity of the bellows, that is, the deviation thereof in the radial direction. Further, the passage provided between the outer circumference of the bellows and the inner circumference of the valve body allows the fluid to flow axially along with the expansion and contraction of the bellows, thereby facilitating the expansion and contraction of the bellows.

[0009]

According to the pressure regulating valve of the first invention, the base end portion is fixed to the valve main body, extends inside the bellows along the axial direction of the bellows, and is in sliding contact with the inner surface of the tip end portion of the bellows. Since it has the guide tube portion that regulates the eccentricity, the following effects can be obtained. First, although the valve can be opened and closed accurately and smoothly by preventing the eccentricity of the bellows, the movable part of the valve, that is, the bellows can be remarkably lighter than before, and therefore the responsiveness of the valve opening and closing operation can be accelerated. Second, size reduction can be achieved by omitting the above-mentioned conventional valve guide and plug. Thirdly, since the sliding guide surface (the outer peripheral surface of the tip of the guide cylinder) is located inside the bellows, chips and dust in the controlled fluid such as fuel will get caught in this sliding guide surface. It is possible to prevent obstruction of sliding of the bellows.

In the pressure regulating valve of the second invention, the inner peripheral surface of the valve body guides the tip end portion of the bellows relatively slidably in the axial direction to prevent eccentricity of the bellows, and the outer circumference of the bellows and the valve body. The passage provided between the inner periphery and the inner periphery allows the fluid to flow in the axial direction as the bellows expands and contracts, so that the following effects can be obtained. First, despite the bellows eccentricity prevention, the valve can be opened and closed accurately and smoothly.
Since the movable portion of the valve, that is, the bellows can be remarkably lightened as compared with the conventional one, the responsiveness of the valve opening / closing operation can be accelerated. Second, size reduction can be achieved by omitting the above-mentioned conventional valve guide and plug.

[0011]

【Example】

(Embodiment 1) An embodiment applied to a fuel valve of an ignition type internal combustion engine will be described below with reference to FIG. This fuel valve includes a valve body 1, a fixed valve seat 2 fixed in the valve body 1, a bellows 3 reciprocally housed in the valve body 1, and a ball held by a tip portion 32 of the bellows 3. The valve 4, a ball valve holding cylinder 5 fitted to the tip end portion 32 of the bellows 3 and irremovably surrounding the ball valve 4, and a spring 6 arranged in the bellows 3 for urging the bellows 3 in the valve closing direction. I have it.

The valve body 1 includes a main cylinder 11 having a stepped cylindrical shape with openings at both ends, and a substantially annular plate-like end plate that closes the opening at the large-diameter end (upper end in FIG. 1) of the main cylinder 11. 12 and end plate 12
The pressure introducing cylinder 13 is inserted into the central hole of the pressure introducing cylinder 13. The upper end of the main cylinder 11 is the largest diameter base end cylinder, and the center of the main cylinder 11 is the middle diameter center cylinder.
The lower part of is the smallest diameter tip tube part. Further, a fuel inlet (inflow hole in the present invention) 15 is opened in the central tubular portion, while a tip opening of the tip tubular portion serves as a fuel outlet 16.

The fixed valve seat 2 is press-fitted in the upper portion of the above-mentioned tip cylinder portion of the valve body 1, and a valve hole 21 is vertically formed in the central portion of the fixed valve seat 2. The bellows 3 includes a base end portion 31 having a short-axis cylindrical shape with openings at both ends, a bellows-shaped elastic portion 33 that hangs downward from the lower end of the base end portion 31 in FIG. 1, and an elastic portion 3.
3 is formed at the lower end of the expansion / contraction part 3 and includes a tip part 32 that shields the lower end opening of the expansion / contraction part 33, and is formed integrally with resin.

The base end portion 31 is fitted and fixed to the upper end portion of the central cylindrical portion of the valve body 1, and an oil seal 34 is fitted around the outer periphery of the base end portion 31. The upper end surface of the base end portion 31 is in contact with the lower surface of the end plate 12. The expandable part 33 is the main cylinder 1
It is accommodated in the central tubular portion of the unit 1 so as to be vertically movable. The thickness of the expansion / contraction part 33 is about 0.1 to 0.5 mm, the outer diameter of the widest part of the expansion / contraction part 33 is about 12 mm, and the clearance between the expansion / contraction part 33 and the inner peripheral surface of the valve body 1 is set. Is set to several hundreds to several thousands μm.

The tip portion 32 has a short-axis cylindrical shape with a large diameter circular collar 32a at the upper end, and a mortar-shaped ball receiving chamber 32b for receiving the ball valve 4 is formed at the center of the lower end surface thereof. 1, a spring chamber 32c is recessed upward from the center of the ball receiving chamber 32b. Ball receiving room 3
The ball valve 4 is rotatably housed in 2b and the spring chamber 3
A spring (not shown) for urging the ball valve is housed in 2c.

The ball valve holding cylinder 5 is a cap having a circular hole in the center thereof, and is attached to the lower end surface of the tip 32 of the bellows 3 to prevent the ball valve 4 from falling off. In FIG. 1, the spherical surface of the ball valve 4 exposed from the circular hole of the ball valve holding cylinder 5 closes the valve hole 21. A spring 6 is accommodated in the bellows 3, the base end of the spring 6 is locked to the stepped portion of the pressure introducing cylinder 13, and the tip of the spring 6 is located below the tip 32 of the bellows 3 via a spring seat 61. Energized in the valve closing direction. A circular recess 32b is provided on the upper end surface of the tip 32 of the bellows 3 as shown in FIG.
Seated in 2b.

The structure which characterizes this embodiment will be described below with reference to FIG. The pressure introducing cylinder 13 is made of a thin-walled stepped cylinder having openings at both ends (see FIG. 1), is deeply hung inside the bellows 3, and its tip end faces the spring seat 61 in close proximity. The outer peripheral surface of the lower end portion 13b of the pressure introducing cylinder 13 is slidably fitted into the inner peripheral surface 32c of the circular recess 32b of the tip portion 32 of the bellows 3, and slide guide for guiding the tip portion 32 of the bellows 3. Is a face.

The outer peripheral corners of the lower end surface of the pressure introducing cylinder 13 are chamfered to form a chamfered portion 13c in order to smooth the sliding of the inner peripheral surface 32c of the bellows 3. There is. Further, four through holes 13a are formed in the lower end portion 13b of the pressure introducing cylinder 13. Among the components described above, the bellows 3 is made of PTFE (polytetrafluoroethylene) resin, the oil seal 14 is made of fluororubber, and the other parts are made of stainless steel.

The order of assembling the valves will be described. First, the ball valve holding cylinder 5 holds the ball valve 4 on the bellows 3, then the spring seat 61 and the spring 6 are housed in the bellows 3, and then the pressure is introduced. The cylinder 13 is fitted into the bellows 3 and the end plate 12, and the end of the large-diameter cylindrical portion of the main cylinder 11 is caulked to the outer circumference of the end plate 12. The oil seal 14 is fitted in advance on the bellows 3, and the fixed valve seat 2 is fixed inside the valve body 1 in advance.

Next, the fitting amount of the pressure introducing cylinder 13 into the end plate 12 is adjusted to set the pressure, and then the pressure introducing cylinder 13 is set.
The end plate 12 and the end plate 12 are welded to complete the assembly. Next, production of the bellows 3 will be described. Bellows 3 is PTFE
A cylindrical body made of resin is prepared, its outer peripheral surface is first cut by a lathe, then its outer peripheral surface is clamped by a split cylindrical chuck, and its inner peripheral surface is cut and formed. Of course, the bellows 3 may be formed by a resin molding technique instead of cutting. As the material of the bellows 3, the PTFE resin is adopted in the above-mentioned embodiment, but other fluorine resin having the same characteristics as that and having excellent moldability, for example, ETFE (polyethylene tetrafluoroethylene), PEP (perfluoroethylene propylene). , P
FA (perfluoroalkoxy) may be adopted.

Next, the operation of this fuel valve will be described. When the intake pressure of the engine introduced from the intake manifold (not shown) into the pressure introducing cylinder 13 is high, the sum of the intake pressure acting on the bellows 3 and the urging force of the spring 6 is introduced from the fuel inlet 15. Then, the fuel pressure in the fuel pipe system acting on the bellows 3 becomes larger, the bellows 3 expands, the ball valve 4 is pressed against the fixed valve seat 2, and the valve hole 2
1 is closed, and by this closing, the fuel leakage from the valve body 1 to the fuel tank (not shown) is prohibited, and the pressure of the fuel piping system rises corresponding to the intake pressure of the engine.

Pressure intake tube 13 from intake manifold
When the intake pressure of the engine introduced into the engine becomes low and the sum of this intake pressure acting on the bellows 3 and the urging force of the spring 6 becomes smaller than the fuel pressure acting on the bellows 3, the bellows 3 contracts and the ball valve 3 4 is separated from the fixed valve seat 2 and the valve hole 21 is opened. By this valve opening, the fuel flows out from the valve body 1 to the fuel tank (not shown), and as a result, the pressure of the fuel piping system becomes the intake pressure of the engine. Correspondingly decreases.

Here, a biasing force acts in the eccentric direction (radial direction) on the bellows 3 due to fuel flow or external vibration, but in this embodiment, the outer peripheral surface of the tip portion 13b of the pressure introducing cylinder 13 is a bellows. Since the inner peripheral surface 32c of the tip end portion 32 of the guide 3 is slidably guided, the eccentricity of the bellows 3 can be prevented.
As a result, it is possible to prevent the opening degree of the valve from varying due to the eccentricity of the ball valve 4, and to prevent the pressure regulation response from deteriorating. Also, it is possible to prevent uneven wear of the valve hole 21, and further to prevent the bellows 3 from being inoperable due to prying. It is also possible to prevent deterioration of oil tightness (pressure retention) due to deterioration of the valve closing function.

The through hole 13a provided in the tip portion 13b of the pressure introducing cylinder 13 is a pressure introducing hole for causing the intake pressure of the engine to act on the inner surface of the bellows 3. Further, the bellows 3 can be centered only by the pressure introducing cylinder 13, which is simple. Further, the actual expansion / contraction amount of the bellows 3 is small (for example, 0.2 mm), and the lower end portion 13 b of the pressure introducing cylinder 13 is
Is designed to always be fitted with the inner peripheral surface 32c of the tip portion 32 of the bellows 3. Also, the pressure introducing cylinder 1
As shown in FIG. 2, the lower end portion 13b of 3 and the tip portion 32 of the bellows 3 are chamfered to prevent prying.

It is naturally possible to integrate the fixed valve seat 2 with the valve body 1, and it is naturally possible that the tip portion 32 of the bellows 3 also serves as the valve body instead of the ball valve 4. (Modification) A modification is shown in FIG. In this aspect, the outer peripheral surface of the spring seat 61 is replaced by the lower end portion 1 of the pressure introducing cylinder 13 instead of the inner peripheral surface 32 c of the tip portion 32 of the bellows 3.
It is slidably guided by the inner peripheral surface of 3b. Further, in order to prevent the spring seat 61 from being displaced in the radial direction with respect to the lower end portion 32 of the bellows 3, a cylindrical protrusion 32e is provided at the center of the upper end surface of the lower end portion 32 of the bellows 3, and the center of the spring seat 61 is further provided. A concave portion 61a to be fitted into this cylindrical protrusion 32e is provided in the portion.

In this modified embodiment, the lower end portion 1
The inner peripheral corner of the end face of 3b or the spring seat 61
By chamfering the outer peripheral corner portion on the upper side, the lower end portion 13b and the spring seat 61 can slide smoothly. (Modification) Another modification is shown in FIG.

In this embodiment, instead of hanging down the pressure introducing cylinder 13, the flange portion 71 of the flanged cylinder 7 is attached to the end plate 1.
The main body 11 is swaged and overlapped with the main cylinder 11, and the cylindrical portion 72 of the flanged cylinder 7 is hung inside the bellows 3. The outer peripheral surface of the lower end of the cylindrical portion 72 slides on the inner peripheral surface of the tip 32 of the bellows 3. Guide freely. 73 is a pressure introduction hole. These modified modes have the same effects as the first embodiment. (Embodiment 2) Another embodiment is shown in FIGS.

In this embodiment, instead of hanging down the pressure introducing cylinder 13, the inner peripheral surface 11a of the main cylinder 11 is used as a sliding guide surface. Then, the circular flange 32a of the tip portion 32 of the bellows 3 is formed.
The outer peripheral surface of the main cylinder 11 is brought into sliding contact with the inner peripheral surface 11a of the main cylinder 11 with a predetermined minute clearance. Further, in the circular brim 32a of the tip portion 32, four places on the outer periphery thereof are removed to remove the four passages 3
2d is formed. Then, the passage 32d connects the upper space S1 in the main cylinder defined by the outer peripheral surface 33 of the expandable portion of the bellows 3 and the main cylinder 11 with the lower space S2 in the main cylinder on the ball valve 4 side. There is. Due to the passage 32d, the fuel pressure change in the lower space S2 in the main cylinder is controlled.
1, so that pressure can be applied to the entire expandable portion 33 of the bellows 3. Further, when the expansion / contraction part 33 of the bellows 3 contracts, the fuel between the folds of the bellows 3 flows out smoothly without hindering the expansion / contraction.

According to this embodiment, the ball valve 4 which is a movable valve
Since the tip portion 32 of the bellows 3 supporting the bellows is guided by the inner peripheral surface of the main cylinder 11, the eccentricity of the bellows 3 can be prevented with a simple configuration. In addition, the tip 32 of the bellows 3 and the main cylinder 11
The deterioration of the fuel mobility due to the reduction of the gap between the passage 3 and the passage 3 formed on the outer circumference of the circular flange 32a of the tip portion 32.
It is possible to prevent the eccentricity of the bellows by guiding the tip end portion 32 of the bellows 3 while ensuring the flow of fuel by 2d.

A groove extending in the vertical direction may be formed on the side of the main cylinder 11 so that the fuel pressure is introduced into the entire bellows 3.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a fuel pressure regulating valve to which the present invention is applied,

FIG. 2 is an enlarged cross-sectional view of a main part of FIG.

FIG. 3 is a cross-sectional view showing a modification of the pressure regulating valve of FIG.

FIG. 4 is a cross-sectional view showing a modification of the pressure regulating valve of FIG.

FIG. 5 is a cross-sectional view showing another embodiment,

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

[Explanation of Codes] 1 is a valve body, 21 is a valve hole, 2 is a fixed valve seat, 13 is a pressure introducing cylinder (guide cylinder), 3 is a bellows, 4 is a ball valve, 15 is an inlet, 16 is an outlet. , 31 are the base ends of the bellows 3, 3
2 is the tip of the bellows 3, 33 is the expandable part of the bellows 3,

Continuation of the front page (72) Inventor Ryuichi Haritani 1-3-3 Ginza, Chuo-ku, Tokyo Kyosan Electric Co., Ltd.

Claims (2)

[Claims] 1. A tubular valve body having an internal space into which a fluid is introduced, a fixed valve seat having a valve hole communicating with the internal space of the valve body and fixed in the valve body, and a base end. In a pressure regulating valve comprising a tubular bellows, a portion of which is fixed to the valve body, a central portion of which expands and contracts, and a tip portion of which opens and closes the valve hole, a base end portion of which is fixed to the valve body and A pressure regulating valve, which is provided with a guide tube portion that extends inside along the axial direction of the bellows and that is in sliding contact with the inner surface of the bellows to regulate the eccentricity of the bellows. 2. A tubular valve main body having an internal space into which a fluid is introduced, a fixed valve seat having a valve hole communicating with the internal space of the valve main body and fixed in the valve main body, and a base end. A bellows, a portion of which is fixed to the valve body, a central portion of which expands and contracts and a tip portion of which opens and closes the valve hole, wherein the bellows slides axially relative to an inner peripheral surface of the valve body. A pressure regulating valve which is movably guided and has a passage formed between an outer periphery of the bellows and an inner peripheral surface of the valve body to allow a fluid to flow therethrough in an axial direction.