JP3300644B2 - Slow-acting on-off valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a normally-open or normally-closed on-off valve, in which a dead time from introduction of a valve opening pressure to operation of a valve body is shortened.

[0002]

2. Description of the Related Art Slow-acting on-off valves are used when it is desired to introduce high-pressure gas slowly, or when it is desired to stop the introduction slowly. It is preferable that the slow operation on-off valve has a short dead time from when a valve opening signal (pressure) or a valve closing signal is given to when the valve operates, while the operation of the valve itself is slow. For this reason, various mechanisms have been conventionally proposed, but the conventional product requires a separately complicated valve mechanism and is expensive.

[0003]

SUMMARY OF THE INVENTION The present invention is a slow-acting valve which has a short dead time from when an operation signal (pressure) is applied to when it is actually operated, does not require a complicated valve mechanism, and has a low cost. The purpose is to get a valve.

[0004]

SUMMARY OF THE INVENTION A slow-acting on-off valve according to the present invention comprises an operating rod for operating a valve element which opens and closes a flow path by coming into contact with and separating from a valve seat; Spring means for biasing; a piston body connected to the operating rod and slidably fitted in the cylinder; a fixed shaft member relatively slidably fitted to the piston body and the operating rod; defined by the piston body, the cylinder and the fixed shaft member. Pressure chamber formed;
When a working fluid is supplied to the pressure chamber, a sliding gap between the piston body and the fixed shaft member and a slit passage provided in the sliding portion; Open the end of the slit passage,
The pressure chamber is communicated with the working fluid passage through a slit passage and a sliding gap between the piston body and the fixed shaft member, and when the piston body starts moving from the moving end, a gap between the piston body and the fixed shaft member is formed. A seal member supported by a piston body or a fixed shaft member, which closes the sliding gap and allows the pressure chamber and the working fluid passage to communicate only with the slit passage.

[0005] In the slow-acting on-off valve of the present invention, when it is necessary to open or close the valve rapidly with the working fluid of the piston, the amount of movement of the piston by the working fluid exceeds a certain value. The seal member can be separated from the sliding gap, and the pressure chamber can be directly communicated with the working fluid passage without passing through the slit passage.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the illustrated embodiment, the present invention is applied to a normally closed type booster on / off valve. First, the overall structure of the booster valve will be described. The flow path block 11 includes a pair of flow path connection ports 12 and 13 on the same axis, and an on-off valve connection port 14 orthogonal to the axis of the pair of flow path connection ports. The flow paths 12a, 1 in the flow path connection ports 12 and 13
3a is open toward the on-off valve connection port 14 side, and the flow path 12
An annular valve seat 15 is provided at the open end of the portion (a). The on-off valve connection port 14 has a disk-shaped metal diaphragm 16 that covers the annular valve seat 15 and the open end of the flow path 13 a, a retainer 17 that presses the peripheral edge thereof, and is movably supported in the retainer 17. An on-off valve element 18 is provided. In this example, the flow path 12 a is on the supply side of the high-pressure fluid, and the annular valve seat 15 is located at the center of the metal diaphragm 16.
The on-off valve element 18 comes into contact with and separates from the center of the metal diaphragm 16 and is pressed against the annular valve seat 15 by a force that overcomes the pressure of the fluid in the flow path 12a. cut off.

The lower housing 21a of the booster on / off valve 20 is screwed to the on / off valve connection port 14. The housing 21 includes the lower housing 21a and an upper housing 21b connected to the lower housing 21a by a lock ring 21c.

In the housing 21, as a movable member,
1 and 2, a valve shaft assembly 24, a pair of idler roller members 25, and an operation member 26 are inserted and supported in order from the bottom. The valve shaft assembly 24 includes a valve shaft 22 that moves the on-off valve body 18 in a direction that comes into and away from the annular valve seat 15,
And a pair of valve shaft roller members 23. Each of the pair of valve shaft roller members 23 includes an outer peripheral roller 23a and a shaft member 23.
The shaft member 23b is supported by a support block 22a having the valve shaft 22 integrated therewith. The pair of valve shaft roller members 23 (shaft members 23 b) are arranged in a rotationally symmetric position with respect to the axis of the valve shaft 22 and in parallel with each other in a positional relationship orthogonal to the axis of the valve shaft 22 without intersecting with the axis of the valve shaft 22.

The operating member 26 integrally has an operating rod 27 coaxial with the valve shaft 22 and a piston body 29 integrally connected to an intermediate portion of the operating rod 27. The outer peripheral portion of the piston body 29 is slidably fitted to the housing 21 (the upper half cylinder of the lower housing 21 a) in an airtight manner, and the inner peripheral portion is the outer peripheral surface of the central cylindrical portion 32 of the fixed shaft member 30. 32a is slidably fitted to 32a. An operating rod 27 is slidably inserted through an O-ring 32c in an air-tight manner through an inner peripheral surface 32b of the central cylindrical portion 32. An outer peripheral portion of the fixed shaft member 30 is air-tightly fixed to a housing (cylinder) 21.
9 (the operating rod 27) and the fixed shaft member 30 define a (valve-opened) pressure chamber 31.

As shown in FIGS. 5 and 6, a sliding gap C1 exists between the outer peripheral surface 32a of the central cylindrical portion 32 of the pressure chamber 31 and the piston body 29, and the inner peripheral surface 32b A sliding gap C2 also exists between the operating rod 27. The sliding gap C2 is closed by the O-ring 32c, and the airtightness of the pressure chamber 31 is maintained. This airtight pressure chamber 31
A pilot pressure source via an axial passage (working fluid passage) 33a and a radial passage (same) 33b formed in the operation rod 27, a pilot pressure introduction port 34 of the upper housing 21b, and an opening / closing control valve 35. A pilot pressure (compressed air) P from 36 is exerted.

The piston body 29 and the upper housing 21b
The compression spring 37 is inserted between the
6 is constantly biased toward the valve shaft assembly 24 side.
A tapered surface portion 27a is formed at the distal end of the operating rod 27 of the operating member 26, and the pair of floating roller members 25 are provided between the tapered surface portion 27a and the valve shaft roller member 23 of the valve shaft assembly 24. Has been inserted. The tapered surface portion 27a has a conical tapered shaft portion 2 as shown in FIG.
7a1 or a wedge surface 27a2 having a flat surface as shown in FIG.

Each floating roller member 25 includes an outer peripheral roller 25.
a and a shaft member 25b, the outer peripheral roller 25a is housed in the recess 30a on the lower surface of the fixed shaft member 30 so as not to move in the axial direction, and the shaft member 25b is mounted on the lower surface guide wall 30b of the fixed shaft member 30. It is guided movably. The pair of floating roller members 25 are parallel to the valve shaft roller member 23, and are located between the tapered surface portion 27 a of the operating rod 27 and the pair of valve shaft roller members 23. Actuating member 2
6 is applied to the tapered surface portion 27a of the operating rod 27, the idle roller member 25, and the valve shaft roller member 23.
Through the valve shaft 22.

The taper of the tapered surface portion 27a of the operating rod 27, the outer diameter of the floating roller member 25 and the valve shaft roller member 23, and the initial position (the position when the on-off valve body 18 is separated from the annular valve seat 15) are as follows. It is determined as follows. That is, the operating member 26 moves to the valve shaft assembly 24 side,
When the valve shaft 22 moves toward the annular valve seat 15 via the tapered surface portion 27a, the idle roller member 25, and the valve shaft roller member 23, the valve shaft 22 moves relative to the unit movement amount of the operating member 26. These are set so as to move by a smaller moving amount. For example, the moving amount of the operating member 26: the moving amount of the valve shaft 22 = 1: 0.2 or 1: 0.1
Determined as follows. In any operation state, the tapered surface portion 27a, the idle roller member 25, and the valve shaft roller member 23
Maintains the contact state, and even when the operating member 26 moves to the valve shaft assembly 24 side to the maximum, the axial position of the floating roller member 25 does not move outside the axial position of the valve shaft roller member 23. . 24a is a valve shaft assembly 2
4 is a weak compression spring that urges the valve 4 toward the valve opening side.

As described above, the sliding gap C1 exists between the outer peripheral surface 32a of the central cylindrical portion 32 of the fixed shaft member 31 and the piston body 29 (see FIGS. 5 to 8). The compressed air from the pilot pressure source 36 is guided to the pressure chamber 31 via the moving gap C1. One or a plurality of slit passages 40 communicating with the sliding gap C1 and extending linearly or spirally in the axial direction are formed in the central cylindrical portion 32 constituting the sliding gap C1. The one-way seal member 41 facing the sliding gap C1 is held by the piston body 29. This one-way sealing member 41
When the contact is made with the outer peripheral surface 32a of the central tubular portion 32, the sliding gap C1 is closed, and the pilot pressure source 36 (radial passage 33b) and the pressure chamber 31 communicate with each other only through the slit passage 40 ( 6 and 7). However, in the state of FIG. 5 in which the piston body 29 is located at the moving end by the force of the compression spring 37, the one-way seal member 41 opens the lower end of the slit passage 40 (the outer peripheral surface 3 of the central tubular portion 32).
2a), pilot pressure source 36 (radial passage 3
3b) and the pressure chamber 31 are communicated via the sliding gap C1 and the slit passage 40. Therefore, the communication area between the pilot pressure source 36 (the radial passage 33b) and the pressure chamber 31 is clearly larger in the state of FIG. 5 than in the state of FIG.

The above-described booster on-off valve operates as follows. When the compressed air is not introduced into the pressure chamber 31, the operating member 26 moves toward the valve shaft assembly 24 by the force of the compression spring 37. This moving force (valve closing force) is transmitted to the valve shaft 22 via the tapered surface portion 27a of the operating rod 27, the idle roller member 25, and the valve shaft roller member 23, and the valve shaft 22 connects the on-off valve body 18 to the annular valve. Move it to the seat 15 side,
As shown in FIG. 1, the flow path 12 is formed through the metal diaphragm 16.
The communication between a and 13a is cut off.

At this time, as shown in FIG. 5, the one-way sealing member 41 held by the piston body 29 is
The lower end of the slit passage 40 is opened away from the outer peripheral surface 32a of the central cylindrical portion 32, and the pilot pressure source 36 (radial passage 33b) and the pressure chamber 31 are largely communicated by the sliding gap C1 and the slit passage 40. They are connected by area.

From this state, when the open / close control valve 35 is opened and the compressed air of the pilot pressure source 36 is guided to the axial passage 33a and the radial passage 33b of the operating rod 27, the compressed air is transmitted to the central cylindrical portion 32. It is guided to the pressure chamber 31 via the sliding gap C1 between the piston body 29 and the slit passage 40. Therefore, compressed air flows at a flow rate based on the total cross-sectional area of the sliding gap C1 and the slit passage 40 into the pressure chamber 31,
A sufficient pressure against the compression spring 37 is instantaneously applied to the pressure chamber 31.
And the piston body 29 (the operating rod 27) slightly moves, and the valve shaft 22 finely moves by 1/10 or 1/5 of the moving amount of the piston body 29 in the above example. I do. As a result, the opening / closing valve element 18 is slightly separated from the annular valve seat 15 and the valve opening is started. The dead time until the valve is opened corresponds to the section a in FIG. 10, and the dead time can be shortened.

When the valve opening is started, the one-way sealing member 41 of the piston body 29 is
It comes into contact with the outer peripheral surface 32a of the (fixed shaft member 31) to close the sliding gap C1 (FIG. 6). That is, the pilot pressure source 36 (the radial passage 33b) and the pressure chamber 31
They communicate only through the slit passage 40. Accordingly, the area of communication between the pilot pressure source 36 (radial passage 33b) and the pressure chamber 31 decreases sharply, and in this state, the one-way seal member 41 comes into contact with the outer peripheral surface 32a as shown in FIG. It lasts for as long as it remains. Therefore, the amount of compressed air guided to the pressure chamber 31 per unit time is limited, and the piston body 29 (the operating rod 27 and the valve shaft 22) moves at a low speed (section b in FIG. 10). The movement of the operation rod 27 (valve shaft 22) in this section b is a slow operation valve opening operation.

When the piston body 29 further rises, the one-way sealing member 41 eventually becomes the outer circumferential surface 32 of the central tubular portion 32.
The contact with a is released (FIGS. 8 and 2). This state is a state in which the pilot pressure source 36 (radial passage 33b) and the pressure chamber 31 are in direct communication with each other.
(22) rapidly reaches the valve opening end. The valve-opening end is regulated at a position where the piston body 29 contacts the stopper surface 42 of the piston 21. This section corresponds to section c in FIG.

Looking at the entire valve opening operation described above, in the initial stage of valve opening when compressed air is introduced into the pressure chamber 31 (when a valve opening signal is given), the piston is operated with a small dead time (section a in FIG. 10). When the body 29 (the valve shaft 22) starts to move and the valve starts to open, a gentle operation is obtained (b), and when the valve opening reaches a certain value, the valve is fully opened immediately (c). can get. Of course, if the last quick valve opening operation is unnecessary, the one-way sealing member 4
What is necessary is just to set various elements so that 1 may contact the outer peripheral surface 32a. The slow operation speed can be set by the total cross-sectional area of the slit passage 40.

When the pilot pressure is exhausted, the compression spring 37
The valve shaft 22 presses the opening / closing valve body 18 against the annular valve seat 15 by the force of (1), and closes the valve (the valve closes in a short time because the one-way seal member 41 is used). Looking at the transmission path of the force at this time, when the valve closing force of the operating member 26 is transmitted to the valve shaft 22 via the tapered surface portion 27a, the idle roller member 25, and the valve shaft roller member 23, the operating member 26 Since the valve shaft 22 moves by a movement amount smaller than the unit movement amount, a large closing force can be obtained with a small compression spring 37 force.
In the above example, a valve closing force 5 times or 10 times the force of the compression spring 37 is obtained.

FIG. 9 shows another embodiment of the present invention, in which a piston body 29 is slidably supported with respect to an operating rod 27 by a predetermined distance, and a spring means 44 such as a disc spring or a wave spring is used. Thus, the piston body 29 is urged to move in a direction against the compression spring 37. The force of the spring means 44 is
Before the compressed air is fed into the pressure chamber 31, the spring means 44 is compressed to a maximum and the piston body 29 is at the lower end with respect to the actuation rod 27. When the compressed air is introduced into the pressure chamber 31 and overcomes the force of the compression spring 37, the piston body 29 moves relative to the operation rod 27 by a certain distance by the force of the spring means 44, and then moves together with the operation rod 27. I do. Therefore, according to this embodiment, when the compressed air is introduced into the pressure chamber 31 and the piston body 29 starts moving, an operation mode in which the initial movement is not transmitted to the operating rod 27 is obtained. The broken line in FIG. 10 shows an example of the operation characteristic at this time (the valve is not opened in the section a).

In the illustrated example, the amount of movement of the piston body 29 (operating rod 27) is much larger than the amount of movement of the valve shaft 22 (valve shaft assembly 24) that actually opens and closes the flow path. The present invention is applied to a valve.
Of course, the present invention can be applied to a direct connection type in which the piston body 29 and the piston body 29 are integrally connected.

Further, as shown in the illustrated embodiment, the present invention can be applied not only to a normally-closed on-off valve that obtains a valve closing pressure by a spring pressure, but also to a normally-opening on-off valve that obtains a valve closing pressure by a pilot pressure. it can.

[0025]

According to the present invention, a slow-acting valve having a short dead time from application of an operation signal (pressure) to actual operation can be obtained without requiring a complicated valve mechanism.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a closed state, showing an embodiment in which a slow-acting on-off valve according to the present invention is applied to a normally-closed booster on-off valve.

FIG. 2 is a longitudinal sectional view of the valve opening state.

FIG. 3 is a perspective view showing a relationship between a tapered surface portion, a floating roller member, and a valve shaft floating member of the on-off valve shown in FIGS. 1 and 2;

FIG. 4 is a perspective view similar to FIG. 3, showing another example of the shape of the tapered surface of the booster on / off valve shown in FIGS. 1 and 2;

FIG. 5 is an enlarged cross-sectional view showing a state when a piston body, a fixed shaft member, and a seal member are closed.

FIG. 6 is an enlarged cross-sectional view showing a state in which the loosening operation has started.

FIG. 7 is an enlarged sectional view showing a state during a slow operation.

FIG. 8 is an enlarged sectional view showing a state in which the loosening operation has been completed.

FIG. 9 is an enlarged sectional view showing another embodiment of a piston body, a fixed shaft member, and a seal member.

FIG. 10 is a graph showing an example of valve opening characteristics of a slow-acting on-off valve according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Flow path block 15 Annular valve seat 16 Metal diaphragm 18 On-off valve body 20 Boost on-off valve 21 Housing 22 Valve shaft 23 Valve shaft roller member 24 Valve shaft assembly 25 Floating roller member 26 Operating member 27 Operating rod 27a2 Wedge surface 29 Piston Reference Signs List 30 fixed shaft member 31 pressure chamber 32 central cylindrical portion 32a outer peripheral surface 32b inner peripheral surface 33a axial passage (working fluid passage) 33b radial passage (working fluid passage) 34 pilot pressure introduction port 35 on-off control valve 36 pilot pressure source 37 compression spring (biasing means) 40 slit passage 41 (one-way) seal member

Claims (2)

(57) [Claims] An operating rod for operating a valve body which opens and closes a flow path by coming into contact with and separating from a valve seat; spring means for urging the operating rod in a direction in which the valve element closes or opens the flow path; A piston body connected and slidably fitted in the cylinder; a fixed shaft member movably fitted to the piston body and the operating rod; a pressure chamber defined by the piston body, the cylinder and the fixed shaft member; Providing a working fluid to the chamber, a sliding gap between the piston body and the fixed shaft member and a slit passage provided in the sliding portion; and when the piston body is located at the moving end by the spring means,
By opening the end of the slit passage, the pressure chamber is communicated with the working fluid passage through the slit passage and the sliding gap between the piston body and the fixed shaft member, and the piston body starts moving from the moving end. A seal member supported by the piston body or the fixed shaft member, which closes a sliding gap between the piston body and the fixed shaft member and allows the pressure chamber and the working fluid passage to communicate only with the slit passage. Slow-acting on-off valve. 2. The slow-acting on-off valve according to claim 1, wherein
When the amount of movement of the piston body by the working fluid exceeds a certain value, the seal member separates from the sliding gap and is a slow-acting on-off valve that directly communicates the pressure chamber with the working fluid passage without passing through the slit passage.