JP7453017B2 - valve mechanism - Google Patents

Description

TECHNICAL FIELD The present invention relates to a valve mechanism in which a shaft member having a valve stopper or a valve seat at one end is movably supported within a hole.

In a valve mechanism having a valve body having a valve stem and a guide (valve body holding member) that movably supports the valve stem of the valve body, if the valve mechanism is configured so that the valve stem does not come into contact with the guide, The valve body deviates from the target position and the position accuracy decreases. On the other hand, if the valve stem is brought into contact with the guide to increase the positional accuracy, the frictional resistance when the valve body opens and closes will increase. As a conventional valve mechanism that suppresses this frictional resistance, there is one described, for example, in Patent Document 1.

The valve mechanism disclosed in Patent Document 1 is configured as shown in FIG. 10. In FIG. 10, reference numeral 1 indicates a valve body, 2 indicates a shaft member that supports the valve body 1, and 3 indicates a guide member that supports the shaft member 2 in a movable manner. The shaft member 2 is inserted into the through hole 4 of the guide member 3 and moves in the axial direction. By moving the shaft member 2 upward in FIG. 10, the valve body 1 is seated on the valve seat 5, and the fluid passage 6 is closed.

In this valve mechanism 7, a seal member 8 is provided between the valve body 1 and the guide member 3 in order to prevent fluid from leaking through the gap between the shaft member 2 and the through hole 4. . The seal member 8 is held in a predetermined position by being sandwiched between a ring-shaped seal holding member 9 and a backup ring 10. In this valve mechanism 7, a guide member 3 guides the shaft member 2, and a seal member 8 seals a portion through which the shaft member 2 is inserted (hereinafter simply referred to as an insertion portion).

JP2011-70420A

In the valve mechanism 7 shown in Patent Document 1, the guide of the shaft member 2 and the seal of the insertion portion of the shaft member 2 are each performed by different structures and parts, so there is a problem that the number of parts increases. .

An object of the present invention is to provide a valve mechanism in which the guide for the shaft member of the valve and the seal for the insertion portion of the shaft member can be realized by one part, and the number of parts is reduced.

In order to achieve such an object, the valve mechanism according to the present invention includes a shaft member provided with a valve plug portion or a valve seat at one end, and a hole into which the shaft member is inserted so as to be movable in the axial direction. a valve mechanism that is attached to an outer circumferential surface of the shaft member opposite to an inner circumferential surface of the hole to seal between the inner circumferential surface of the hole and the outer circumferential surface of the shaft member; A guide ring is provided for movably guiding the hole along the inner circumferential surface of the hole.

In the valve mechanism according to the present invention, the one end of the shaft member is constituted by the valve plug portion, and the valve seat is configured such that the valve seat member has the hole into which the shaft member is inserted. The hole that is provided to be seated and into which the shaft member is inserted includes a valve hole that is provided in the valve seat member and opens at the center of the valve seat, and a valve body holder that is disposed opposite to the valve seat member. The shaft member has a guide hole provided in the member and located on the same axis as the valve hole, and the shaft member is connected to the valve plug portion at one end and extends toward the valve body holding member at the other end. , the other end side has a valve shaft that is inserted into the guide hole of the valve body holding member and guided by the inner circumferential surface of the guide hole, and the guide ring is arranged between the valve stem and the inner circumferential surface of the guide hole. It may be provided between.

In the valve mechanism according to the present invention, the one end of the shaft member is constituted by the valve seat, and the valve plug portion is configured to attach the valve body to the valve body accommodated in the hole into which the shaft member is inserted. The hole, which is provided to sit on the valve seat and into which the shaft member is inserted, has a valve hole that accommodates the valve body, and a guide hole that is located on the same axis as the valve hole, and The member has a valve shaft that is provided with the valve seat at one end and is guided by an inner peripheral surface of the guide hole, and the guide ring is provided between the valve shaft and the inner peripheral surface of the guide hole. It may be.

In the valve mechanism of the present invention, the guide ring is an annular member having a cut in a direction different from the axial direction, and the inner diameter of the guide ring is the outer diameter of the shaft member before being attached to the shaft member. The diameter of the guide ring may be smaller than the diameter of the guide ring, and when attached to the shaft member, the guide ring expands in diameter and comes into contact with the inner circumferential surface of the hole into which the shaft member is inserted, thereby generating surface pressure.

In the present invention, in the valve mechanism, the valve seat member and the valve body holding member may be integrally formed.

In the present invention, the valve mechanism may include a biasing member that biases the shaft member in a direction along the valve shaft.

In the present invention, the guide ring guides the shaft member and seals the insertion portion of the shaft member. Therefore, it is possible to provide a valve mechanism in which the guide of the shaft member and the seal of the insertion portion of the shaft member can be realized by one component, and the number of components is reduced.

FIG. 1 is a sectional view of a pressure reducing valve equipped with a valve mechanism according to the present invention. FIG. 2 is an enlarged cross-sectional view of the main parts. FIG. 3 is a cross-sectional view of the intake port. FIG. 4 is a perspective view of the guide ring. FIG. 5 is a schematic diagram of the guide ring. FIG. 6 is a schematic diagram of the guide ring. FIG. 7 is a sectional view showing the configuration of a pilot relay equipped with a valve mechanism according to the present invention. FIG. 8 is a sectional view showing another usage example of the guide ring. FIG. 9 is a perspective view showing another embodiment of the guide ring. FIG. 10 is a sectional view of a conventional valve mechanism.

(First embodiment)
Hereinafter, one embodiment of the valve mechanism according to the present invention will be described in detail with reference to FIGS. 1 to 6. The valve mechanism shown in the first embodiment is an implementation of the invention described in claims 1, 2, 4 to 6. In this embodiment, an example in which the valve mechanism according to the present invention is applied to a pressure reducing valve will be shown.

The pressure reducing valve 11 shown in FIG. 1 includes a body 15 having a valve mechanism 12 according to the present invention, a fluid inlet 13, and a fluid outlet 14, and a diaphragm 16 connected to one end (the upper end in FIG. 1) of the body 15. It is provided with a bonnet 17 and the like attached to the fluid inlet 13 to reduce the pressure of the fluid supplied to the fluid inlet 13 and guide it to the fluid outlet 14. The fluid flowing through this pressure reducing valve 11 is gas.

A cup-shaped drain bowl 19 is attached to the other end of the body 15 via a gasket 18. The inside of the drain bowl 19 is connected to the fluid inlet 13 through an upstream passage hole 20, and is also connected to the fluid outlet 14 through a through hole 21 and a downstream passage hole 22 in the center of the body. The through hole 21 of the body 15 is formed to penetrate through the center of the body 15. A filter 23 is provided between the inside of the drain bowl 19 and the through hole 21. A valve mechanism 12, which will be described later, is provided inside the through hole 21.

A diaphragm 16 located between the body 15 and the bonnet 17 is formed into a disk shape, and forms a diaphragm chamber 24 between the diaphragm 16 and the body 15. The diaphragm chamber 24 has an open through hole 21 in the body 15 and is connected to the downstream passage hole 22 via a small hole 25 . A pressing member 26 is provided at the center of the diaphragm 16. This pressing member 26 is for pressing the valve body 31 of the valve mechanism 12, which will be described later.

A passage hole 32 extending in the thickness direction of the diaphragm 16 and penetrating the pressing member 26 is formed in the pressing member 26 . Further, the pressing member 26 is urged toward the body 15 by a pressure regulating spring 33 made of a compression coil spring.
The pressure regulating spring 33 is provided between these members with one end pushing the pressing member 26 and the other end pushing the pressure regulating spring receiver 34 . One end of the pressure adjustment knob 35 screwed onto the bonnet 17 contacts the pressure adjustment spring receiver 34, and the pressure adjustment spring receiver 34 is held between the pressure adjustment knob 35 and the pressure adjustment spring 33.

The valve mechanism 12 includes a cylindrical intake port 41 that is fitted and fixed in a through hole 21 of a body 15, and a valve body inserted into a hole 42 (see FIG. 2) in the center of the intake port 41. 31, and a valve spring 43 made of a compression coil spring that biases one end of the valve body 31.
As shown in FIG. 3, the intake port 41 is constructed by integrally forming a plurality of members. The plurality of members include a valve seat member 44 that is a half of the intake port 41 on one end side (drain bowl 19 side), and a valve body holding member that is a half of the intake port 41 on the other end side (bonnet 17 side). It is 45. The valve seat member 44 has a valve seat 46 and a valve hole 47 that opens at the center of the valve seat 46 .

The valve body holding member 45 is arranged to face the valve seat member 44 . A guide hole 48 consisting of a stepped through hole is formed inside (center portion) of the valve body holding member 45 so as to be connected to the valve hole 47 . The valve hole 47 and the guide hole 48 have circular opening shapes, are located on the same axis, and constitute the hole 42 in the center of the intake port 41. The guide hole 48 is formed by a small diameter part 48a connected to the valve hole 47, a large diameter part 48b opening into the diaphragm chamber 24, and a central part 48c located between the small diameter part 48a and the large diameter part 48b. ing. The hole diameter of the central portion 48c is larger than the hole diameter of the small diameter portion 48a and smaller than the hole diameter of the large diameter portion 48b.

An annular groove 49 extending in the circumferential direction is formed on the outer peripheral surface of the intake port 41. A portion of this groove 49 is connected to the downstream passage hole 22. Furthermore, a plurality of communication holes 50 that extend radially within the intake port 41 are opened in the groove 49 . The communication hole 50 communicates the inside of the groove 49 and the inside of the valve hole 47 .

The valve body 31 corresponds to the "shaft member" in the present invention. One end (lower end in the figure) of the valve body 31 is constituted by a valve plug portion 51 that is seated on the valve seat 46, as shown in FIG. The valve body 31 has a valve shaft 52 connected to the valve plug portion 51 at one end and whose other end extends toward the valve body holding member 45 . A valve spring 43 is provided in the valve plug portion 51 . The valve spring 43 constitutes a "biasing member" in the present invention, and biases the valve body 31 in the direction along the valve shaft 52.

The valve spring 43 is installed between the valve spring receiver 53 (see FIG. 1) provided at the upstream opening of the through hole 21 and the valve plug portion 51.
The valve shaft 52 is formed in a cylindrical shape, and the other end thereof is inserted into the guide hole 48 of the valve body holding member 45, and is guided on the inner peripheral surface of the guide hole 48 via a guide ring 54, which will be described later.
The other end of the valve shaft 52 is formed into a hemispherical shape, contacts the above-mentioned pressing member 26, and closes the passage hole 32 of the pressing member 26.

Guide ring 54 is a single annular member, as shown in FIG. As shown in FIG. 2, this guide ring 54 has a valve shaft 52 passing through it, is attached to the outer peripheral surface of the valve shaft 52 that faces the inner peripheral surface of the guide hole 48, and is inserted into the center portion 48c of the guide hole 48. has been done. Further, the guide ring 54 is held within the center portion 48c by a flat washer 55 and a spring washer 56 inserted into the large diameter portion 48b of the guide hole 48 so that it cannot move toward the large diameter portion 48b. There is. Note that movement of the guide ring 54 in the circumferential direction is restricted by frictional resistance.

The guide ring 54 according to this embodiment is an annular member having a cut 61 formed in a direction different from the axial direction. The cross-sectional shape of the guide ring 54 in a direction perpendicular to the circumferential direction is a quadrilateral as shown in FIG. As shown in FIG. 2, the cut 61 is formed to be inclined at a predetermined angle with respect to the axis C of the guide ring 54 when the guide ring 54 is viewed from a direction perpendicular to the axial direction. It extends from one end surface of the ring 54 in the axial direction to the other end surface.

When the cut 61 is formed parallel to the axis of the guide ring 54, the guide ring 54 cannot contact the valve shaft 52 at the cut 61. In this case, the force with which the guide ring 54 presses the valve shaft 52 becomes uneven in the circumferential direction, which may cause the valve body 31 to become eccentric. However, if the cut 61 is inclined as shown in this embodiment, even if the guide ring 54 expands a little, the contact is less likely to become uneven in the circumferential direction, thereby reducing the eccentricity of the valve body 31. be able to.

The inner diameter of the guide ring 54 is smaller than the outer diameter of the valve stem 52 before it is attached to the valve stem 52. The outer diameter of the guide ring 54 is the same as or smaller than the inner diameter of the center portion 48c of the guide hole 48. Since a portion of the guide ring 54 is cut by the cut 61, the guide ring 54 expands in diameter when attached to the valve shaft 52. Therefore, the guide ring 54 does not necessarily require as much extensibility as general rubber, and can be formed from a resin material or a composite material such as glass fiber-containing resin.

The guide ring 54 according to this embodiment is configured such that the outer circumferential surface of the guide ring 54 comes into contact with the valve body holding member 45 (the inner circumferential surface of the central portion 48c of the guide hole 48) when the guide ring 54 is attached to the valve shaft 52. There is. Hereinafter, the inner circumferential surface of the central portion 48c of the guide hole 48 will be simply referred to as the "guide hole inner circumferential surface." FIG. 2 depicts the guide ring 54 in a state before thermal expansion occurs, and a minute gap G is formed between the outer peripheral surface of the guide ring 54 and the inner peripheral surface of the guide hole. When the guide ring 54 undergoes thermal expansion, the outer peripheral surface of the guide ring 54 comes into close contact with the inner peripheral surface of the guide hole.

This guide ring 54 is configured to generate a predetermined surface pressure on the inner circumferential surface of the guide hole when the diameter of the guide ring 54 is expanded by the valve shaft 52 and the outer circumferential surface is in contact with the valve body holding member 45. . The guide ring 54 that is in close contact with the valve stem 52 and the inner circumferential surface of the guide hole seals between the inner circumferential surface of the guide hole of the valve body holding member 45 and the outer circumferential surface of the valve stem 52, and guides the valve shaft 52 movably along the inner peripheral surface of the guide hole of the valve body holding member 45.

Here, the force F required for inserting the valve shaft 52 into the guide ring 54 and expanding the inner diameter of the guide ring 54 by ΔR will be described with reference to FIG. Here, as shown in Fig. 5, the inner diameter of the cylindrical ring A is R, the thickness of the ring A is t, the width (length in the axial direction) of the ring A is B, and the internal pressure acting on the inner peripheral surface of the ring A is will be explained as p.

When a valve inserted into ring A with inner diameter R expands and expands the ring inner diameter by ΔR, if internal pressure p acts on a cylinder with inner diameter R and wall thickness t, ring A expands and the circumferential tension is expressed by the following equation. A stress σ _t is generated. Note that, in the following, the Young's modulus of ring A is assumed to be E.
Since the resultant force of internal pressure and the resultant force of circumferential stress are balanced,
2σ _t tB=2RBp
σ _t =Rp/t
According to Hooke's law, the circumferential strain is ε _t =σ _t /E=Rp/tE
From the definition of strain, the increase amount ΔR in the radial direction is 2πRε _t =2π(R+ΔR)−2πR
ε _t =ΔR/R
Therefore,
Rp/tE=ΔR/R
ΔR=(R ² /tE)p
p=tEΔR/R ² =tσ _t /R
The force F to increase the inner diameter by ΔR is calculated by multiplying the pressure P by the area of the inner diameter, F=2πRBP=2πRB・(tEΔR/R ² )=2πtBEΔR/R
At this time, the circumference widens by 2πΔR.

On the other hand, considering the force F' required to cut one end of ring A and open it by 2πΔR, this force F' will be applied to the tip of cantilever B with length L = 2R, as shown in Figure 6. This is considered to be about the same force as applying a load and deflecting it by 2πΔR.
The moment of inertia I of the beam B is
I=Bt ³ /12
The deflection ε _t is
ε _t =F'L ³ /3EI=2πΔR
Substituting I and L, 2πΔR={4F'(2R) ³ }/EBt ³
F'=2πΔREBt ³ /4(2R) ³ =πEBt ³ ΔR/2(2R) ³

F'<F means that
t ² <8(2R) ²
t<(4√2)R (t>0, R>0)
According to the above assumption, if t is smaller than 4√2R, it means that it is easier to spread with a notch. Further, in actual design, it is assumed that t≦R, but when t=R, F'/F=1/32, and the required force is sufficiently smaller when there is a notch.
On the other hand, if t is larger than 4√2R, the depth of cut does not make much sense. Note that the actual deformation does not become a perfect circle, and the above calculation results do not exactly match the measured values.

The flow rate of fluid flowing through the pressure reducing valve 11 configured in this manner changes depending on the position of the pressing member 26 provided on the diaphragm 16. The pressing member 26 moves in a direction away from the intake port 41 when the force pushing the diaphragm 16 toward the bonnet 17 side, including the pressure in the diaphragm chamber 24, is greater than the spring force of the pressure regulating spring 33. The spring force of the pressure regulating spring 33 increases by tightening the pressure regulating knob 35 against the bonnet 17, and decreases by loosening the pressure regulating knob 35.

When the pressure of the fluid decreases at the fluid outlet 14 of the pressure reducing valve 11, the pressure in the diaphragm chamber 24 decreases, so the pressing member 26 comes to press the valve stem 52 of the valve body 31, and the valve plug portion 51 of the valve body 31 moves away from the valve seat 46, and the valve mechanism 12 opens. When the valve mechanism 12 opens, fluid flows from the fluid inlet 13 through the upstream passage hole 20 and the inside of the drain bowl 19 into the through hole 21 of the body 15, and further flows from the valve hole 47 of the intake port 41 into the communication hole 50. It flows into the downstream passage hole 22 through the annular groove 49 and the like. When fluid flows into the downstream passage hole 22 in this manner and the pressure in the downstream passage hole 22 rises to a predetermined pressure, the pressure in the diaphragm chamber 24 rises and the valve mechanism 12 closes. When the valve mechanism 12 opens and closes in this manner, the valve shaft 52 of the valve body 31 moves while slidingly contacting the inner peripheral surface of the guide ring 54.

That is, the valve shaft 52 moves while being guided by the guide ring 54 in a state where the space between the valve shaft 52 and the guide ring 54 is sealed. Therefore, according to this embodiment, the guide ring 54 guides the valve shaft 52 of the valve body 31 and seals the insertion portion of the valve shaft 52, so that the guide ring 54 guides the valve shaft 52 and seals the insertion portion of the valve shaft 52. It is possible to provide a valve mechanism in which the seal and the seal can be realized by one part, and the number of parts is reduced.

The guide ring 54 according to this embodiment is an annular member having a cut 61 formed in a direction different from the axial direction. The inner diameter of the guide ring 54 is smaller than the outer diameter of the valve stem 52 before it is attached to the valve stem 52. The guide ring 54 is configured to expand in diameter when attached to the valve shaft 52 and come into contact with the valve body holding member 45 to generate surface pressure on the inner circumferential surface of the guide hole.
Since the cut 61 is formed diagonally, the guide ring 54 presses the valve shaft 52 substantially uniformly in the circumferential direction, so that the valve body 31 is less likely to be eccentric. Further, when the end surfaces of the guide ring 54 come into contact with each other at the cut 61 when the guide ring 54 is pressed against the inner circumferential surface of the guide hole, leakage of fluid due to fluid passing through the cut 61 can be suppressed to a minimum.

The valve seat member 44 and valve body holding member 45 of the intake port 41 according to this embodiment are integrally formed. Therefore, the valve hole 47 and the guide hole 48 are accurately positioned on the same axis, so that the guide ring 54 can correctly guide the movement of the valve shaft 52 when the valve body 31 opens and closes. Become.

The valve mechanism 12 according to this embodiment is provided with a valve spring 43 that biases the valve body 31 in a direction along the valve shaft 52. Therefore, when the pressing member 26 moves away from the valve body 31, the valve body 31 follows with good responsiveness against friction with the guide ring 54, and the valve mechanism 12 closes. Therefore, even though the guide ring 54 is provided, a valve mechanism with high responsiveness is realized.

(Second embodiment)
The valve mechanism according to the present invention can be applied to a pilot relay of a positioner, as shown in FIG. The valve mechanism shown in the second embodiment is an implementation of the invention described in claims 1 and 3.
A positioner is used to control the opening of an air-operated valve, and is often equipped with a pilot relay to amplify the air signal.

A pilot relay 71 shown in FIG. 7 includes a piston valve 73 as a "shaft member" of a valve mechanism 72 according to the present invention. The piston valve 73 has a valve shaft 75 movably inserted into a cylinder hole 74 in the housing 71a on one end side (lower side in FIG. 7), and has first and second diaphragms 76, 77 on the other end side. It is supported by the housing 71a via.
A back pressure chamber 81 is formed between the first diaphragm 76 and the housing 71a, and is supplied with a nozzle back pressure PN, which is air pressure corresponding to an electrical signal. A bias chamber 82 is formed between the first diaphragm 76 and the second diaphragm 77, and has a bias pressure PB equal to the pressure of driving air supplied to an air-operated valve (not shown). Supplied.

An exhaust chamber 83 is formed between the second diaphragm 77 and the housing 71a. The exhaust chamber 83 is connected to a vent hole 84.
One end (lower end in FIG. 7) of the valve shaft 75 is constituted by a first valve seat 87 on which a first valve body 86 of a poppet valve 85, which will be described later, is seated. An exhaust passage 91 is formed in the axial center of the valve shaft 75. One end of the exhaust passage 91 opens to the first valve seat 87, and the other end opens to the exhaust chamber 83.

The cylinder hole 74 in the housing 71a has a valve hole 92 that accommodates the poppet valve 85, and a guide hole 93 located on the same axis as the valve hole 92. A supply air pressure PS for controlling the opening degree of the air-operated valve is supplied to one end (lower end in FIG. 7) of the valve hole 92. Further, an annular second valve seat 94 is provided at one end of the valve hole 92 . A poppet valve 85 is passed through the second valve seat 94, and a second valve body 95 at one end of the poppet valve 85 is seated. The poppet valve 85 is supported at one end by the housing 71a via a plate-shaped spring member 96.

A portion of the guide hole 93 of the cylinder hole 74 that borders the valve hole 92 communicates with an output chamber 97 and is connected to an actuator of an air-operated valve (not shown).
A valve shaft 75 of the piston valve 73 is supported in this guide hole 93 via a guide ring 101.
The guide ring 101 is a single member similar to the guide ring 54 shown in the first embodiment, and has a rectangular annular cross-sectional shape, and although not shown, it is shown in FIG. A cut equivalent to the cut 61 is formed. This guide ring 101 is attached to the outer circumferential surface of the valve shaft 75 facing the inner circumferential surface of the guide hole 93, and seals between the inner circumferential surface of the guide hole 93 and the outer circumferential surface of the valve shaft 75, and also seals the valve shaft. 75 is movably guided along the inner peripheral surface of the guide hole 93.

That is, the guide ring 101 allows the guide of the valve shaft 75 and the insertion portion of the valve shaft 75 to be connected both when the piston valve 73 moves to one end side (lower side in FIG. 7) and when it moves to the other end side. Seal and do. The piston valve 73 moves toward one end as the nozzle back pressure PN increases and the pressure in the back pressure chamber 81 increases. By moving the piston valve 73 to one end, the poppet valve 85 is pushed away from the second valve seat 94, and supply air pressure is supplied to the air-operated valve through the valve hole 92 and the output chamber 97. Ru. On the other hand, the piston valve 73 moves toward the other end due to the pressure in the bias chamber 82 and the output chamber 97 as the nozzle back pressure PN decreases. As the piston valve 73 moves to the other end, the second valve body 31 seats on the second valve seat 94 and the supply of air pressure is stopped, and driving air is supplied from the air-operated valve to the output chamber 97. The air is exhausted through the exhaust passage 91 and the exhaust chamber 83.

As shown in this embodiment, by providing the pilot relay 71 with the valve mechanism 72 according to the present invention, it is possible to realize a pilot relay in which the piston valve 73 operates smoothly and the piston valve 73 operates with high reliability. can.

(Other usage examples of guide rings)
The guide ring of the present invention can be used to support a pilot relay poppet valve, as shown in FIG. 8 is an enlarged sectional view showing only the poppet valve portion of the pilot relay shown in FIG. 7. FIG. In FIG. 8, members that are the same as or equivalent to those explained using FIG. 7 are given the same reference numerals, and detailed explanations are omitted as appropriate.

The poppet valve 85 shown in FIG. 8 has a cylindrical valve shaft 111, and is movably supported by the housing 71a via a guide ring 112 through which the valve shaft 111 passes.
The guide ring 112 is a single member similar to the guide ring 54 shown in the first embodiment, and has a rectangular annular cross-sectional shape, and although not shown, it is shown in FIG. A cut equivalent to the cut 61 is formed. This guide ring 112 is attached to the outer circumferential surface of the valve shaft 111 and held by the projecting wall 113 of the housing 71a.
Since the poppet valve 85 is supported by the guide ring 112 in this manner, the support of the poppet valve 85 is stabilized, and the reliability of the operation of the poppet valve 85 is increased.

(Other embodiments of guide ring)
The guide ring can be configured as shown in FIG.
The guide ring 121 shown in FIG. 9 is divided into a first half 122 and a second half 123. The first half portion 122 and the second half portion 123 are each formed in a semicircular shape when viewed from the axial direction of the guide ring 121. The cross-sectional shapes of the first half 122 and the second half 123 when viewed in the longitudinal direction, that is, the cross-sectional shapes in a direction perpendicular to the circumferential direction of the guide ring 121 are quadrangular like the guide ring 54 described above. .

Both ends of the first half 122 and the second half 123 that are aligned with each other are formed by inclined surfaces 122a and 123a that are inclined in a direction different from the axial direction of the guide ring 121. Therefore, the guide ring 121 configured by combining the first half part 122 and the second half part 123 becomes an annular member with cuts 124 formed in two places in the circumferential direction in a direction different from the axial direction. .
Even when the guide ring 121 is constituted by the first and second halves 122, 123, one guide ring 121 can be used to guide the shaft member and the shaft, as in the case of the above-described embodiment. The insertion portion of the member can be sealed.

DESCRIPTION OF SYMBOLS 11... Pressure reducing valve, 12, 72... Valve mechanism, 21... Through hole, 31... Valve body (shaft member), 43... Valve spring (biasing member), 44... Valve seat member, 45... Valve body holding member, 46 ...Valve seat, 47,92...Valve hole, 48,93...Guide hole, 51...Valve plug part, 54,101,112,121...Guide ring, 52,75...Valve stem, 61...Slit, 73...Piston valve (shaft member), 74... cylinder hole, 86... first valve body, 87... first valve seat.

Claims (6)

a shaft member provided with a valve plug portion or a valve seat at one end;
A valve mechanism having a hole into which the shaft member is inserted so as to be movable in the axial direction,
It is attached to the outer circumferential surface of the shaft member opposite to the inner circumferential surface of the hole to seal between the inner circumferential surface of the hole and the outer circumferential surface of the shaft member, and also to connect the shaft member to the inner circumferential surface of the hole. A valve mechanism characterized by comprising a guide ring movably guided along. The valve mechanism according to claim 1,
The one end of the shaft member is constituted by the valve plug part,
The valve seat is provided such that the valve plug part is seated in the valve seat member having the hole into which the shaft member is inserted,
The hole into which the shaft member is inserted is
a valve hole provided in a valve seat member and opening in the center of the valve seat;
a guide hole provided in a valve body holding member disposed opposite to the valve seat member and located on the same axis as the valve hole;
The shaft member is connected to the valve plug part at one end, and has the other end extending toward the valve body holding member, and the other end side is inserted into the guide hole of the valve body holding member and extends into the guide hole. It has a valve stem guided by the circumferential surface,
The valve mechanism is characterized in that the guide ring is provided between the valve shaft and the inner peripheral surface of the guide hole. The valve mechanism according to claim 1,
The one end of the shaft member is configured by the valve seat,
The valve plug portion is provided in a valve body accommodated in the hole into which the shaft member is inserted so as to be seated on the valve seat,
The hole into which the shaft member is inserted is
a valve hole that accommodates the valve body;
a guide hole located on the same axis as the valve hole,
The shaft member has a valve shaft provided at one end of the valve seat and guided by an inner circumferential surface of the guide hole,
The valve mechanism is characterized in that the guide ring is provided between the valve shaft and the inner peripheral surface of the guide hole. In the valve mechanism according to any one of claims 1 to 3,
The guide ring is an annular member having a cut in a direction different from the axial direction, and the inner diameter of the guide ring is smaller than the outer diameter of the shaft member before being attached to the shaft member, and the inner diameter of the guide ring is smaller than the outer diameter of the shaft member before being attached to the shaft member. A valve mechanism characterized in that when attached to a member, the guide ring expands in diameter and comes into contact with an inner circumferential surface of the hole into which the shaft member is inserted, thereby generating surface pressure. The valve mechanism according to claim 2,
A valve mechanism, wherein the valve seat member and the valve body holding member are integrally formed. The valve mechanism according to claim 2,
A valve mechanism comprising: a biasing member that biases the shaft member in a direction along the valve shaft.

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