JP3359953B2 - 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 slow-acting on-off valve capable of obtaining a slow opening / closing operation.

[0002]

2. Description of the Related Art For example, when mixing certain gases in a reaction chamber, it is sometimes required to supply the gas to be mixed to the reaction chamber as slowly as possible. In order to respond to such a demand, the present applicant has devised a slow-acting on-off valve which has excellent responsiveness from the application of a valve-opening signal to the valve-opening operation, while the valve-opening operation itself is slow. See Heihei 3-34387).

However, according to subsequent studies, according to the slow-acting on-off valve, the valve is opened from the action of the pilot pressure due to the line pressure, the operating pressure, the reaction force of the spring used, and the variation of each part. It has been found that a considerable time delay (response delay) may occur before starting.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the conventional slow-acting on-off valve, and eliminates the response delay irrespective of the factors causing the response delay. An object of the present invention is to provide a slow-acting on-off valve capable of always improving responsiveness after a pressure action.

[0005]

SUMMARY OF THE INVENTION The present invention provides a valve rod having a valve body that opens and closes a flow path by coming into contact with and away from a valve seat; a diaphragm assembly connected to the valve rod; A valve opening pressure chamber for applying a valve opening pressure to the diaphragm assembly; a pilot pressure passage communicating with the valve opening pressure chamber; a flow control valve provided in the pilot pressure passage;
A preload passage separate from the pilot pressure passage for communicating the valve opening pressure chamber with the pilot pressure source; provided in this preload passage;
A preload opening / closing valve urged in a normally closing direction; a preload opening / closing valve operating member that opens the preload opening / closing valve against its urging force when the valve rod is in a valve closing position; a diaphragm assembly sandwiched between the valve rods A pressure adjusting screw member which is positioned on the opposite side of the valve opening pressure chamber and supported so as to be relatively rotatable; a spring receiver which is screw-coupled to an outer peripheral portion of the pressure adjusting screw member and is supported so as to be able to move straight in the axial direction of the valve rod; And a compression spring contracted between the spring receiving member and the diaphragm assembly.

In the slow-acting on-off valve having the above structure, when the valve rod is in the closed position, the valve-opening pressure chamber communicates with not only the pilot pressure passage having the flow control valve but also the pre-pressure passage having the pre-pressure opening / closing valve. Therefore, when the pilot pressure is introduced into the pilot pressure passage and the pre-compression passage, the pressure in the valve opening pressure chamber can be quickly increased, and the valve rod can be quickly moved in the valve opening direction. The force for urging the valve rod in the valve closing direction can be adjusted by rotating the pressure adjusting screw member to adjust the axial position of the valve rod of the spring receiving member, thereby eliminating the response delay. Thus, the responsiveness at the time of introducing the pilot pressure can always be improved. When the valve rod moves in the valve opening direction, the preload on-off valve is closed by its own biasing force, so that pilot pressure is introduced into the valve opening pressure chamber only through the flow control valve, so that the valve opening speed is slow. Can be obtained.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on illustrated embodiments. 1 is a cross-sectional view showing the entire structure of a slow-acting on-off valve according to the present invention, FIG. 2 is a cross-sectional view showing an enlarged main part of FIG. 1, and FIG. 3 is a part showing another cross-section of the same on-off valve. It is sectional drawing.

A fluid passage 12 is provided in a valve body 11 shown in the lower part of FIG.
3 are formed. The valve rod 1 is attached to the annular valve seat 13.
4 comes into contact with and separates from the valve body 15 provided at the lower end of the fluid passage 1.
2 is opened and closed.

The valve rod 14 penetrates through the spacer 16 and the connector sleeve 17 and projects upward in FIG. A bellows 18 is stretched between the lower part of the valve rod 14 and the spacer 16 so that the fluid flowing through the fluid passage 12 does not reach the shaft of the valve rod 14. That is, the on-off valve is a clean valve that guarantees the cleanness of the fluid flowing through the fluid passage 12 by the bellows 18. A compression spring 20 for urging the valve rod 14 in the valve closing direction via a washer 19 is inserted into the connector sleeve 17. Reference numeral 21 denotes a cap nut for fixing the connector sleeve 17 to the valve body 11. The above elements are assembled in a clean room in advance and unitized.

A cylinder 22 is fitted around the outer periphery of the connector sleeve 17 and is fixed to the connector sleeve 17 via a washer 23a and a stop ring 23b.

The connector sleeve 17 of the valve rod 14
A diaphragm assembly 27 is slidably provided on the projecting portion from the valve body and is urged to move toward the valve body 15.
The diaphragm assembly 27 has a rolling diaphragm 24, a main block 25 sandwiching the center of the rolling diaphragm 24, and a retainer 26. As shown in FIG. 2, a boss 25b through which the valve rod 14 penetrates is formed at the center of the main block 25, and a recess 25a is formed around the boss 25b with which one end of the compression spring 30 abuts. Have been. Boss part 2
An O-ring 52 is interposed between 5b and the valve rod 14. Also, on the lower surface of the boss portion 25b, a reduced-diameter step portion 25c that engages the increased-diameter step portion 14a of the valve rod 14
Is formed, whereby the diaphragm assembly 27 is formed.
Is restricted at the moving end when moving downward.

A pressure adjusting screw member 53 is fitted above the valve rod 14 above the main block 25. The pressure adjusting screw member 53 has a male screw portion 5 on its outer periphery.
3a, and a fitting projection 53b to be fitted to the boss 25b of the main block 25. Valve rod 1
A washer plate 55 is fitted to the tip of the fourth member 4, and a stop ring 54 is further fixed.

An external thread portion 53a on the outer periphery of the pressure adjusting screw member 53
The female screw portion 58d formed at the center of the spring receiving member 58
Is screwed. A part of the outer peripheral portion of the spring receiving member 58 includes
An insertion hole 58a into which the rotation stopping member 57 is inserted is formed. A bonnet 31 is fitted to the upper part of the cylinder 22 via a lock ring 32. A straight guide groove 31 formed in a part of the inner periphery of the bonnet 31 is formed in a vertical direction.
The rotation stop member 57 is slidably fitted in a. As shown in FIG. 4, a pressure adjusting rotating portion 53c having a rectangular shape in plan view is formed on the upper portion of the pressure adjusting screw member 53.

The spring receiving member 58 and the main block 25 are located on the side opposite to the valve opening pressure chamber 33 with the rolling diaphragm 24 interposed therebetween, and apply an urging force against the valve opening pressure of the valve opening pressure chamber 33. A compression spring (biasing means) 30 acting on the valve rod 14 via the diaphragm assembly 27 is contracted. The other end of the compression spring 30 is in contact with the lower surface of the spring receiving portion 58b of the spring receiving member 58.
The spring receiving member 58 has a set screw hole 58e at an upper portion of the spring receiving portion 58b, and a set screw 59 screwed into the set screw hole 58e is screwed to press the spring receiving portion 58b, so that the spring receiving portion 58b is pressed. The relative movement of the receiving member 58 with respect to the pressure adjusting screw member 53 can be restricted. A pressure adjusting screw member 53 provided on the valve rod 14 so as to allow only relative rotation with respect to the rod 14, and a spring receiving member 58 which is relatively moved with respect to the pressure adjusting screw member 53 when the valve rod 14 rotates. Pressure adjusting means for adjusting the urging force of the compression spring 30 exerted on the valve rod 14 is provided.

The peripheral bead 24a of the rolling diaphragm 24 is sandwiched between the cylinder 22 and the bonnet 31, and the cylinder 22 and the bonnet 31 are fixed by the lock ring 32 with the peripheral bead 24a compressed. I have.

With the above structure, a valve opening pressure chamber 33 is formed below the rolling diaphragm 24. The rolling diaphragm 24 is a diaphragm whose pressure receiving area does not change even when displaced.

A pilot pressure passage 36 communicating with the valve opening pressure chamber 33 is formed in the cylinder 22. The pilot pressure passage 36 communicates with the preload on-off valve chamber 38 through a passage indicated by reference numeral 36a, and then communicates with the needle valve 4 through a communication hole 45a formed in the preload on-off valve 45 and another passage 36b.
0, and further through a passage 36c.
Is in communication with

The needle valve 40 is connected to the pilot pressure passage 36
A male screw body 41 having a needle 41a facing the inside is screwed into the cylinder 22, and by adjusting the screwing position, the amount of throttle of the flow path by the needle 41a is changed to a large or small value.

The preload on-off valve chamber 38 communicates with a valve opening pressure chamber 33 via a preload passage 43 as shown in FIG. Is provided. The preload on-off valve 45 is urged by a compression spring 46 in a direction in which the O-ring 47 is seated on the lower surface of the valve-opening pressure chamber 33, that is, in a valve-closing direction, so that no external force is applied to the preload on-off valve 45. Then, the preload passage 4
3 closes. The upper end of the preload on-off valve 45 extends into the valve-opening pressure chamber 33. When the valve rod 14 is in the valve-closed position by the force of the compression spring 20, the head of the preload on-off valve 45 is retained by the retainer 26 of the diaphragm assembly 27. Is pressed and displaced. That is, the spring force of the compression spring 30 is stronger than the spring force of the compression spring 46, and when the valve rod 14 is at the valve closing position in the drawing by the spring force of the compression spring 20, the preload on-off valve 45 is pressed by the retainer 26. Displaced against the force of the compression spring 46, the preload passage 43 opens. That is, the retainer 26 is a preload opening / closing valve operating member.

The pilot pressure passage 36 communicates with a pilot pressure source P via a switching valve 50. Further, the pilot pressure source P is connected to a rapid valve opening passage 49 (FIG. 3) opened to the valve opening pressure chamber 33 via an on-off valve 51. The on-off valve 51 is normally closed.

In the state of the present embodiment, when the pilot pressure is not introduced into the valve opening pressure chamber 33, the compression spring 2
Due to the zero force, the valve body 15 of the valve rod 14 is seated on the annular valve seat 13 and closes the fluid passage 12. In this state, the retainer 2 of the diaphragm assembly 27 is also
6 pushes the head of the preload on-off valve 45 to open the preload passage 43. That is, the valve opening pressure chamber 33 is
6 and a state in which it can communicate with the pilot pressure source P via the preload passage 43.

In this state, the port 5 of the switching valve 50
0a is connected to the flow path, the pilot pressure from the pilot pressure source P is supplied not only through the pilot pressure passage 36 having the needle valve 40 but also through the pre-pressure passage 43 to the valve opening pressure chamber 3.
It is led to 3. Therefore, the pressure in the valve-opening pressure chamber 33 increases quickly, and when the pressure eventually overcomes the force of the compression spring 30, the diaphragm assembly 27 increases while compressing the compression spring 30.

When the amount of elevation of the diaphragm assembly 27 reaches a predetermined value, the retainer 26 separates from the preload opening / closing valve 45, and at this time, the O-ring 47 of the preload opening / closing valve 45 moves under the preload passage 43 by the force of the compression spring 46. And closes the preload passage 43. Therefore, the valve opening pressure chamber 33 communicates with the pilot pressure source P only through the needle valve 40. The compression spring 30 is now almost fully compressed at this point, after which the diaphragm assembly 27 rises integrally with the valve rod 14.

Therefore, if the supply of the pilot pressure from the pilot pressure source P is continued, thereafter, the valve rod 14 integrally rises at a speed corresponding to the opening of the needle valve 40 to open the fluid passage 12. . Since the valve opening speed can be freely set by adjusting the opening of the needle valve 40, the valve can be opened particularly slowly. That is, after connecting the port 50a of the switching valve 50 to the flow path,
The response time can be improved by shortening the time until the valve 2 starts to open, and the valve opening speed after the opening can be reduced.

When adjusting the response time from the operation of the pilot pressure to the start of the valve opening, first, the pressure adjusting screw member 53 is rotated in an appropriate direction via the pressure adjusting rotating portion 53c. Then, the rotation stopping member 57 is moved to the straight guide groove 3 of the bonnet 31.
The spring receiving member 58 engaged with 1a and stopped from rotation is moved in the axial direction of the bonnet 31, that is, the valve rod 14, due to the relationship between the female screw portion 58d and the male screw portion 53a. Thereby, the spring receiving member 58 and the main block 2
5, the compression spring 30 contracted between them can change the spring pressure. At this time, since the spring receiving member 58 does not rotate and moves straight in the axial direction of the valve rod 14, frictional resistance with the compression spring 30 does not occur. Therefore, by increasing or decreasing the spring force for pressing down the main block 25, that is, the diaphragm assembly 27, the pressure in a certain set state, as shown in the correlation between the pressure in the valve-opening pressure chamber 33 and the pressure increasing time shown in FIG. The time delay (response delay) t from the action of the pilot pressure to the start of valve opening can be eliminated by changing the pressure change as shown in b to the change a. Therefore, responsiveness can be further improved irrespective of the existence of a response delay factor.

On the other hand, when the port 50b of the switching valve 50 is connected to the flow path, the pilot pressure in the valve opening pressure chamber 33 is discharged through the needle valve 40 and the pilot pressure passage 36 soon. As a result, the valve rod 14 returns to the position shown in FIG. 1, and at this time, the retainer 26 of the diaphragm assembly 27 pushes the preload on-off valve 45 to open and opens the preload passage 43.

When it is necessary to rapidly open the fluid passage 12, the on-off valve 51 is opened. Then, the pilot pressure is rapidly led to the valve-opening pressure chamber 33 via the quick-valve passage 49 having no flow-path restricting action. As a result, the diaphragm assembly 2
7 and the valve rod 14 rise rapidly, and the valve body 15
Is separated from the annular valve seat 13 and the fluid passage 12 is opened.

[0028]

As described above, according to the slow-acting on-off valve of the present invention, in the initial stage of the operation for introducing the pilot pressure to the valve-opening pressure chamber, the valve-opening pressure chamber communicates not only with the pilot pressure passage but also with the preload passage. Therefore, the pilot pressure can be quickly introduced into the valve opening pressure chamber. Since the response delay from the action of the pilot pressure to the start of valve opening can be freely adjusted by rotating the pressure adjusting screw member, the response delay is eliminated and the rise after the valve opening signal is reduced. It can be further improved. After the start of the opening / closing valve operation, the preload opening / closing valve closes and the flow rate control valve controls the introduction speed of the pilot pressure, so that the diaphragm can be slowly displaced in the valve opening direction.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the entire structure of a slow-acting on-off valve according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a preload on-off valve portion of the slow operation on-off valve.

FIG. 3 is a cross-sectional view of another part of the same slow-acting on-off valve as the slow-acting on-off valve.

FIG. 4 is a plan view showing the slow operation on-off valve.

FIG. 5 is a diagram showing a correlation between a pressure change in a valve-opening pressure chamber and a pressure increase time.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Valve body 12 Fluid passage 13 Annular valve seat 14 Valve rod 14a Diameter-expanding step part 15 Valve body 17 Connector sleeve 20 Compression spring 22 Cylinder 24 Rolling diaphragm 25 Main block 26 Retainer 27 Diaphragm assembly 30 Compression spring (biasing means) 31a Straight guide groove 33 Valve opening pressure chamber 36 Pilot pressure passage 36a 36b 36c passage 38 Preload opening / closing valve chamber 40 Needle valve 41 Male screw body 41a Needle 43 Preload passage 45 Preload opening / closing valve 45a Communication hole 46 Compression spring 50 Switching valve 53 Adjusting screw member (Pressure adjusting means) 53a Male screw part 53c Pressure adjusting rotating part 57 Rotation stopping member 58 Spring receiving member (pressure adjusting means) 58b Spring receiving part 58e Set screw hole 58d Female screw part 59 Set screw P Pilot pressure source

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Juichi Aoki 1-840 Mitsuhashi, Omiya City, Saitama Prefecture Fujikura Rubber Industries Co., Ltd. Omiya Plant (72) Inventor Mitsuru Hoshi 1-840 Mitsuhashi Omiya City, Saitama Prefecture Fujikura Rubber Co., Ltd. (56) References JP-A-3-134387 (JP, A) JP-A-60-52481 (JP, U) JP-A-2-136879 (JP, U) JP-A-3-60666 (JP) 58-109675 (JP, U) Japanese Utility Model 54-153419 (JP, U) Japanese Utility Model 61-119675 (JP, U) Japanese Patent Publication 49-37048 (JP, B1) (58) Field surveyed (Int.Cl. ⁷ , DB name) F16K 31/12-31/165

Claims (1)

(57) [Claims] 1. A valve rod having a valve body that opens and closes a flow path while coming into contact with and away from a valve seat; a diaphragm assembly connected to the valve rod; and a diaphragm assembly defined by the diaphragm assembly. A pilot pressure passage communicating with the valve opening pressure chamber; a flow control valve provided in the pilot pressure passage; a pilot valve communicating the valve opening pressure chamber with a pilot pressure source. A preload passage separate from the pressure passage; a preload opening / closing valve provided in the preload passage, which is normally biased in the valve closing direction; when the valve rod is in the closed position, the preload opening / closing valve is opposed to its biasing force. Pre-opening / closing valve actuating member that opens by holding the diaphragm assembly on the valve rod
It is located on the opposite side of the valve opening pressure chamber so that it can rotate relatively.
Lifting the pressure adjusting screw member; it is screwed to the outer periphery of the pressure regulating screw member, the valve
Spring receiver supported so as to be able to move straight in the axial direction of the rod
Member; and contracted between the spring receiving member and the diaphragm assembly.
A slowly actuated on-off valve having a compressed spring;