JP2001099350A - Check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a check valve for adjusting the valve opening pressure without generating the noise due to the vibration and without generating a trouble such as turbulence of a fluid flow due to a spring means and the generation of dust. SOLUTION: The generation of vibration when opening a valve can be prevented by giving the moving resistance by the work of an air damper to a valve element, and a spring means is inserted into a pressure chamber so as to provide an initial pressure adjusting mechanism. Considering this point, a valve element energized to a valve seat side for movement by a spring means is provided with a cylinder part with bottom to be fitted in a guide cylinder with bottom, which is positioned inside of a fluid flow passage, freely to be slid so as to form a pressure chamber, and a cracking pressure setting member for changing the initial pressure of the spring member inserted into the pressure chamber on the basis of the axial directional position thereof is supported inside of the guide cylinder with bottom of the valve guide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a check valve.

[0002]

2. Description of the Related Art A check valve is a valve which allows a flow in only one direction. Basically, a valve is pressed against a valve seat by a spring means to close the valve, and fluid pressure is reduced by the force of the spring means. , The valve element has a basic configuration in which the fluid flows away from the valve seat.

[0003] However, the conventional check valve tends to generate vibrations when the valve is opened or turbulence is apt to occur in order to obtain a sufficient amount of free flow. For example, for a medical device used in a hospital room, The noise is a problem.

[0004] Further, since the spring for pressing the valve body against the valve seat is exposed in the fluid passage, the flow of the fluid is disturbed, sometimes causing vibration, and further, there is a problem of dust generation by the spring. May occur.

[0005]

The object of the present invention is therefore to provide vibration (noise) when a valve is opened.
It is an object of the present invention to provide a check valve that does not generate any pressure and that can adjust the valve opening pressure. Another object of the present invention is to provide a check valve which does not cause problems of fluid flow turbulence and dust generation by a spring member.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a valve body is provided with a movement resistance by an air damper action to prevent a vibration phenomenon at the time of valve opening, and a spring means is inserted into a pressure chamber to provide an initial pressure adjusting mechanism. A valve housing having a fluid passage; a valve seat formed on an inner wall of the fluid passage; a valve having a bottomed guide cylinder located in the fluid passage and fixed in the valve housing Guide; a valve body having a bottomed cylinder portion which slidably fits into a bottomed guide cylinder of this valve guide to form a pressure chamber, and is capable of coming and going with respect to a valve seat; A spring member inserted into the pressure chamber for moving and biasing in a contacting direction; and a cracking pressure setting which is supported in a bottomed guide cylinder of the valve guide so as to advance and retreat, and changes an initial pressure of the spring member according to its axial position. A member; Features.

According to this structure, when the valve moves in the direction in which the volume of the pressure chamber decreases, the pressure in the pressure chamber temporarily increases, and when the valve moves in the direction in which the volume increases, the pressure in the pressure chamber increases. Is temporarily reduced, and together with this, resistance can be given to the movement of the valve element. For this reason, the occurrence of the vibration phenomenon can be prevented. The valve opening pressure can be adjusted by the cracking pressure setting member, and since the spring member for applying the cracking pressure is housed in the pressure chamber, there is no problem of turbulence of flow or dust generation due to the spring member.

The valve guide may have a bottomed guide cylinder and may form a pressure chamber between the valve body and the valve body without obstructing the fluid flow. When,
A large-diameter cylindrical portion which is concentric with the bottomed guide cylinder and has a larger diameter than the bottomed guide cylinder and is fitted and fixed in the fluid passage of the valve housing; and the large-diameter cylindrical portion and the bottomed guide cylinder A disk portion to be connected can be provided, and a fluid passage hole can be formed in the disk portion or the disk portion and the large-diameter cylindrical portion. The large-diameter cylindrical portion of the valve guide can be fitted to the large-diameter portion for the valve guide of the fluid passage and fixed by a retaining ring fitted to the large-diameter portion. The large-diameter cylindrical portion and the disk portion are preferably formed such that the disk portion and the retaining ring maintain a space.

It is practical that the cracking pressure setting member is a cracking pressure setting screw screwed into the disk portion of the valve guide.

[0010]

1 to 4 show a first embodiment of a check valve according to the present invention. Valve housing 10
Has a cylindrical shape having a fluid passage 11 in a shaft portion thereof. The fluid passage 11 has a high-pressure small-diameter passage 11a, a large-diameter tapered valve seat 11b, and a low-pressure large-diameter passage 11c in order from the left of FIGS. 1 and 2, and is provided at an end of the low-pressure large-diameter passage 11c. Further, a large diameter portion 11e for a valve guide having a retaining ring insertion groove 11d is formed. Valve housing 1
0, connection screws 10a and 10b for connecting the fluid passage 11 to the pipeline are formed on the outer surfaces of both ends.

The large diameter portion 11e for valve guide has a retaining ring (C ring) fitted in the retaining ring insertion groove 11d.
The valve guide 12 is fixed by 13. As shown in FIG. 4, the valve guide 12 has a large-diameter tubular portion 12a fitted to the valve-guide large-diameter portion 11e and a large-diameter tubular portion 12a concentric with the large-diameter tubular portion 12a. Small-diameter bottomed guide cylinder 12b, large-diameter cylindrical portion 12a and bottomed guide cylinder 1
2b. A fluid passage hole 12d is formed in the disk portion 12c. The large-diameter cylindrical portion 12a is provided with a retaining ring 13 from the disk portion 12c.
Side 12c (fluid passage hole 12
A space s is secured between d) and the retaining ring 13. This space can be formed by a spacer separate from the valve guide 12. However, by increasing the axial length of the large-diameter cylindrical portion 12a and providing the role of the spacer as in this embodiment, It is possible to prevent the valve guide 12 from falling in the fluid passage 11.

The bottomed guide cylinder 12b of the valve guide 12 is closed at the disk portion 12c and open at the opposite end, and the bottomed cylindrical portion 14a of the valve body 14 is slidable on the open side. It is stuck in. The valve element 14 has a tapered portion 14 coaxial with the bottomed cylindrical portion 14a and corresponding to the diameter-increased tapered valve seat 11b.
b, and an annular groove 14c formed in the tapered portion 14b.
An O-ring (seal member) 14d elastically contacting the enlarged diameter tapered valve seat 11b is fitted into the O-ring.

The bottomed guide cylinder 12b of the valve guide 12 and the bottomed cylindrical portion 14a of the valve body 14 which are slidably fitted together form a pressure chamber 15. When the valve body 14 moves relative to the fixed valve guide 12, the pressure chamber 15
An air damper effect that gives resistance by the pressure generated inside is generated.

This air damper action is one of the important actions of the present check valve, and includes the bottomed guide cylinder 12b and the bottomed cylindrical portion 1.
4a. Specifically, the fitting clearance is set such that the valve guide 12 and the valve body 14 are fitted in a state where the bottomed guide cylinder 12b and the bottomed cylindrical portion 14a are fitted.
When the axis is oriented in the vertical direction, it can be expressed as a relationship in which the falling speed is slower than when there is no fitting relationship between the two. In other words, when the volume of the pressure chamber 15 decreases, the pressure in the pressure chamber 15 increases to provide resistance to the approach between the valve guide 12 and the valve body 14, and conversely, when the volume of the pressure chamber 15 increases, The relationship is such that the internal pressure drops to provide resistance to separation between the valve guide 12 and the valve element 14. Of course, the bottomed guide cylinder 12b and the bottomed cylindrical portion 14a
There is no mechanical galling between them.

In the pressure chamber 15, a compression spring 16 for urging the valve body 14 toward the enlarged taper valve seat 11b is housed. The compression spring 16 is inserted into the pressure chamber 15,
There is no exposure to the outside.

A cracking pressure adjusting screw (cracking pressure adjusting member) 17 is screwed into a screw hole 12e formed in the center of the disk portion 12c of the valve guide 12.
The cracking pressure adjusting screw 17 has an inner end extending into the center of the bottomed guide tube 12b and an outer end extending into the large-diameter cylindrical portion 12a of the disk portion 12c. A spring seat 18 is provided at an end of the cracking pressure adjusting screw 17 on the side of the bottomed guide cylinder 12b (the spring seat 18 is interposed between the cracking pressure adjusting screws 17 and 16). A driver groove 17a is formed on the end face of the cracking pressure adjusting screw 17 on the side of the large-diameter cylindrical portion 12a, and a lock nut 19 is screwed therein. The spring seat 18 can be provided at the distal end of the adjustment screw 17 in a state where it cannot be removed. The fluid passage 11 and the valve guide 12 (the large-diameter cylindrical portion 12a,
The bottomed guide cylinder 12b, the disk part 12c), the valve element 14, and the cracking pressure adjusting screw 17 have a rotationally symmetric shape with the axis of the fluid passage 11 as a rotation axis.

The above check valve operates as follows. When the valve element 14 is in the closed position as shown in FIG. 1, the pressure of the fluid passage 11 on the high pressure side small diameter passage 11a side is higher than the pressure on the low pressure side large diameter passage 11c side, and the force of the compression spring 16 and the pressure chamber 15 overcomes the pressure in the valve body 15, the valve body 14 moves to the valve guide 12 side, and the O-ring 14d
1b (FIG. 2). When the valve element 14 moves in the valve opening direction in this way, the volume of the pressure chamber 15 tends to decrease, so that the pressure in the pressure chamber 15 temporarily rises to the valve opening resistance.

When high-pressure air flows from the high-pressure small-diameter passage 11a to the low-pressure large-diameter passage 11c as a result of the opening of the valve body 14, the pressure on the high-pressure small-diameter passage 11a relatively decreases. The valve element 14 tends to move toward the diameter-increased tapered valve seat 11 b by the force of the compression spring 16. When the valve element 14 moves in the valve closing direction in this way, the volume in the pressure chamber 15 tends to increase, and the pressure in the pressure chamber 15 temporarily decreases, resulting in valve closing resistance. Thus, when the valve element 14 moves in any direction, the air damper action is obtained by the pressure in the pressure chamber 15, so that the vibration phenomenon does not occur when the valve is opened. Therefore, noise due to vibration does not occur.

The pressure (cracking pressure) at which the valve element 14 starts moving in the valve opening direction can be adjusted by adjusting the axial position of the cracking pressure adjusting screw 17 in the bottomed guide cylinder 12b. . That is, after the valve housing 10 is removed from the pipe, the lock nut 19 is loosened, a screwdriver is inserted into the driver groove 17a, and the cracking pressure adjusting screw 17 is rotated. The position in the guide cylinder 12b changes. Therefore, the initial pressure of the compression spring 16 pressed via the spring seat 18 changes, and the valve closing pressure for pressing the valve body 14 against the tapered valve seat 11b changes. After adjusting the position of the cracking pressure adjusting screw 17 (cracking pressure adjustment), the locking nut 19 is tightened to lock the cracking pressure adjusting screw 17, and the valve housing 10 is returned to the pipeline, whereby the adjustment of the cracking pressure is completed.

Further, in the illustrated embodiment, since the compression spring 16 is housed in the pressure chamber 15, there is no problem of turbulence of fluid flow or dust generation caused by the spring. The inner and outer relation between the bottomed guide cylinder 12b of the valve guide 12 and the bottomed cylindrical portion 14a of the valve body 14 that slide with each other may be reversed.

FIG. 5 shows another embodiment of the valve guide 12. This example is characterized in that the fluid passage hole 12d is formed not only on the disk portion 12c but also on the disk portion 12c and the large-diameter cylindrical portion 12a in order to secure a larger flow path.
As described above, even if the fluid passage hole 12d is formed so as to straddle the large-diameter tubular portion 12a, the retaining ring 13 is not fitted due to the fitting relationship between the large-diameter tubular portion 12a and the valve guide large-diameter portion 11e. The valve guide 12 (the bottomed guide cylinder 12b) can be prevented from falling down without blockage of the flow path by the fluid passage 1, and the center of the valve body 14 is
In this case, the valve can be slid so as to coincide with the center of the first valve, and the valve can be reliably closed.

[0022]

According to the present invention, there is provided a check valve which does not generate vibration noise and can easily adjust the cracking pressure. Also, since a spring member for moving and urging the valve body toward the valve seat is housed in the pressure chamber,
A check valve free from turbulence and dust generation of the fluid flow due to the spring member is obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a check valve according to a first embodiment of the present invention in a closed state.

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

FIG. 3 is a right side view of FIGS. 1 and 2;

FIG. 4 is a perspective view showing an example of a single shape of a valve guide.

FIG. 5 is a perspective view showing an example of a single shape of another valve guide.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Valve housing 11 Fluid passage 11a High pressure side small diameter passage 11b Large diameter tapered valve seat 11c Low pressure side large diameter passage 11d Retaining ring insertion groove 11e Large diameter portion for valve guide 12 Valve guide 12a Large diameter cylindrical portion 12b Bottomed guide cylinder 12c Disc portion 12d Fluid passage hole 13 Retaining ring 14 Valve element 14a Bottomed cylindrical portion 14b Taper portion 14d O-ring 15 Pressure chamber 16 Compression spring 17 Cracking pressure adjusting screw 17a Driver groove 18 Spring seat 19 Lock nut

Claims (4)

[Claims] 1. A valve housing having a fluid passage; a valve seat formed on an inner wall of the fluid passage; a valve guide having a bottomed guide cylinder located in the fluid passage and fixed in the valve housing; A valve body having a bottomed cylinder portion slidably fitted to a bottomed guide cylinder of a valve guide to form a pressure chamber, and being capable of coming and going with respect to the valve seat; the valve body being in contact with the valve seat A spring member inserted into the pressure chamber to move and urge in a direction of movement; and a cracking supported in the bottomed guide cylinder of the valve guide so as to be able to advance and retreat, and changing the initial pressure of the spring member according to its axial position. A pressure setting member; 2. The check valve according to claim 1, wherein the valve guide has a bottomed guide cylinder, a fluid passage concentric with the bottomed guide cylinder, and having a diameter larger than that of the bottomed guide cylinder. A large-diameter cylindrical portion that is fitted and fixed to, and a disk portion that connects the large-diameter cylindrical portion and the bottomed guide cylinder, and the disk portion or the disk portion and the large-diameter cylindrical portion A check valve with a fluid passage hole. 3. The check valve according to claim 2, wherein the cracking pressure setting member is a cracking pressure setting screw screwed into a disk portion. 4. The check valve according to claim 3, wherein the large-diameter cylindrical portion of the valve guide is fitted to a large-diameter portion for a valve guide of the fluid passage, and a retaining ring fitted to the large-diameter portion. A non-return valve, which is fixed, and wherein the large-diameter tubular portion and the disc portion are formed so that the disc portion and the retaining ring hold a space.