JP2530286Y2 - Long axis type needle valve vibration damping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vibration isolator for a long shaft type needle valve installed in a conduit for a cryogenic fluid such as liquid helium.

[Conventional technology]

The needle valve used for the pipe for the cryogenic fluid has a configuration in which a valve body is fixed to a lid portion of a cryostat, and a valve box is attached to a lower end of the valve body via a relay pipe. In this case, due to the heat insulation structure of the cryostat, the length from the valve body to the valve box is considerably long (for example, 300 to 1200 mm).
Degree) is formed.

The valve box of the above-mentioned needle valve, the valve rod, the valve body, etc. housed therein are at room temperature before the start of use, but when a cryogenic fluid flows through the pipe, the valve box is closed due to thermal contraction of the pipe. Deviates from the body position. The direction of the deviation varies depending on the direction of the piping. In this case, if the valve stem and the valve body are integral, the valve stem will bend, which will hinder opening and closing of the valve body.

As a countermeasure for this, the valve stem and the valve body are separated from each other, the valve stem is further divided into an upper valve stem and a lower valve stem, and both are flexibly connected inside the valve body. Is connected to the inside of the valve box to bend freely.

[Problems to be solved by the invention]

When a long-axis needle valve adopting the above structure is used by attaching it to a conduit for cryogenic fluid such as liquid helium, when the valve is opened and fluid flows through the conduit, the frequency in the audible range is reduced. In some cases, micro-vibration having a unique frequency is generated.

The cause of this vibration is considered as follows. That is, a spring is interposed at the connecting portion between the upper valve stem and the lower valve stem and at the connecting portion between the lower valve stem and the valve body in order to eliminate a gap in the axial direction. It is necessary to secure a sliding gap for this. For this reason, since the valve body and the lower valve stem are not constrained in the radial direction, the structure is easy to move in the radial direction due to the vibration of the fluid. This is considered to be the cause of the generation of micro-vibration.

Therefore, this invention does not hinder the countermeasures against the deviation of the valve box due to the opening and closing operation of the valve and the heat shrinkage of the piping,
An object of the present invention is to prevent vibration of a valve body and a lower valve stem caused by vibration of a fluid flowing through a pipeline.

[Means for solving the problem]

In order to solve the above-mentioned problem, this invention encloses a valve body in a valve box attached to a lower part of a valve body via a relay pipe, and uses a valve rod inserted from the valve body through the relay pipe through the valve box. The lower valve stem comprises an upper valve stem and a lower valve stem, the upper valve stem and the lower valve stem are flexibly provided with an upper connecting portion provided inside the valve body, and the lower valve stem and the valve body are flexibly connected to a lower connecting portion. A length that is provided in a valve box and has a spring that exerts a pressing force in the axial direction between the upper valve stem and the lower valve stem of the upper connection portion and between the lower valve stem and the valve body of the lower connection portion. In the shaft type needle valve, anti-vibration rings are attached to the outer diameter surfaces of the upper end and the lower end of the lower valve stem, respectively, and these are brought into contact with the inner diameter surface of the valve body and the inner diameter surface of the valve box, respectively. Attach vibration isolating rings on the outer diameter surface of the valve body at the upper and lower It is obtained by a structure in which brought into contact with the inner diameter surface.

[Action]

Even if the flow of fluid collides with the valve body, the valve body is radially constrained by the vibration isolating rings at two places above and below the lower connecting part, and the lower valve stem is prevented at two places inside the valve body and inside the valve box. Vibration of the valve body and lower stem is generated by the fact that the upper connecting part and the lower connecting part are applied with axial force by the spring at the upper connecting part and the lower connecting part. To prevent However, these anti-vibration rings allow rotation and vertical movement of the valve stem and valve body, so that there is no problem in opening and closing the valves, and the structure of the connecting portion is the same as before, which impairs the flexibility of bending. Absent.

〔Example〕

In the long-axis needle valve of the embodiment shown in the accompanying drawings, a relay pipe 2 is fixed to a lower end of a valve body 1, and a valve box 3 is fixed to a lower end of the relay pipe 2.

A cap-shaped handle 4 is put on the upper end of the valve body 1 and moves up and down at a minute pitch by screw connection with the valve body 1. The square shaft portion 7 of the upper valve stem 6 is inserted into a square hole at the center of the upper end of the handle 4 and is fixed to the handle 4 by a cap nut 8 or the like.

The upper valve stem 6 is inserted into the through hole 9 of the valve body 1, but has a length that does not reach the lower end of the through hole 9. The upper end of the lower valve stem 10 is inserted into the lower end of the through hole 9.

An O-ring 11 is fitted to the upper valve stem 6, thereby achieving sealing. A coupling joint is provided at the lower end of the upper valve stem 6.
12 are provided. The coupling joint 12 is a T-shaped joint having a large-diameter portion at the lower end of a small-diameter shaft, and is inserted into the coupling hole 15 formed at the upper end of the lower valve stem 10 with a slight gap in the axial and radial directions. Thus, a flexible upper connecting portion 16 is formed.

Also, a coil spring 18 is inserted into the bottom of the connection hole 15,
The ball 19 urged upward by the coil spring 18 is pressed against the lower end surface of the coupling 12 so as to integrate the upper valve stem 6 and the lower valve stem 10, and to lower the lower valve stem 10 via the ball 19. To exert power on the center.

The lower stem 10 is provided with two stem members 2 at the upper and lower ends of the stem pipe 20.
1 and 22 are combined and integrated.
Is provided on the upper end surface of the upper valve stem member 21. The upper valve stem member 21 is inside the through hole 9 of the valve body 1, and a first vibration-proof ring 23 made of a synthetic resin having a very low temperature characteristic such as “DAIFRON” (trade name) is fitted on the outer diameter surface thereof. This anti-vibration ring is worn
23 is pressed against the inner diameter surface of the through hole 9.

The valve stem pipe 20 penetrates through the inside of the relay pipe 2 with a predetermined gap, and is integrated and integrated with the lower valve stem member 22 inside the valve box 3.

The valve box 3 is provided with a lower end portion of the relay pipe 2, a lower valve stem member 22, and a hole 25 for receiving the valve element 24, and the hole 25 communicates with a fluid outlet (or inlet) 28. It communicates with an inlet (or outlet) 26 through a valve hole 27. The valve hole 27 is opened and closed by the vertical movement of the valve element 24.

A second anti-vibration ring 29 made of the same material as that described above is fitted on the outer diameter surface of the lower end portion of the valve stem 22 and pressed against the inner diameter surface of the hole 25.

Further, a T-shaped coupling joint 30 is provided at the lower end of the valve stem member 22, and is inserted into the coupling hole 33 formed at the upper end of the valve body 24 with a slight gap as described above. , The lower connecting portion 34 that can be bent. Hole for connection
A coil spring 36 is inserted into the bottom of 33, and the coil spring 36
By pressing the lower end surface of the joint 30 to integrate the valve body 24 and the lower valve stem 10, and by making the lower end surface of the joint 30 a gentle spherical surface, a force is exerted on the center of the valve body 24. I have to.

Above and below the lower connecting portion 34, third and fourth vibration isolating rings 37 and 38 made of the same material as those described above are fitted to the outer diameter surface of the valve body 24, respectively. Is pressed against.

The long shaft type needle valve of the embodiment having the above-mentioned configuration is fixed to the cryostat 39, and is used by connecting a cryogenic fluid pipe 40 to the inlet 26 and the outlet 28 of the valve box 3.

When the handle 4 is rotated, the handle 4 moves up and down by a small distance according to the screw pitch, and moves up and down while rotating the upper valve stem 6 integrated therewith. At the same time, the lower valve stem 10 connected to the upper valve stem 6 and the valve element 24 connected to the lower valve stem 10 also operate to open and close the valve hole 27.

When the fluid flows due to the opening of the valve hole 27 and the collision with the valve body 24 is repeated, the lower valve stem 10 becomes the first and second vibration isolation rings 23,
As a result of being pressed against the inner diameter surfaces of the valve body 1 and the valve box 3 by 29, the movement in the radial direction is restrained. Valve 24
The movement in the radial direction is also restricted by the third and fourth vibration isolating rings 37 and 38, and the upper connecting portion 6 and the lower connecting portion 34
Since the coil springs 18 and 36 are interposed and the movement in the axial direction is also restrained, the lower valve stem 10 and the valve body 24 do not generate vibration.

Since the vibration isolating rings 23, 29, 37, and 38 do not apply a restraining force in the axial direction, they do not hinder the opening and closing operation of the valve element 24. Also, since there is no effect on the connection structure between the upper connection portion 16 and the lower connection portion 34, the flexibility of the connection portions 16, 34 when the valve box 3 is deviated due to a temperature difference is not impaired.

[Effect of the invention]

As described above, the present invention provides a conventional long-axis type needle valve, in which the valve body and the lower valve stem are provided with two upper and lower vibration-isolating rings respectively at the upper and lower portions, thereby opening and closing the valve body and controlling the temperature difference. Therefore, the vibration of the valve element and the lower valve stem caused by the vibration of the fluid flowing through the pipeline can be prevented without hindering the measures against the displacement of the valve box due to the above.

[Brief description of the drawings]

1 is a partially omitted longitudinal sectional view of the embodiment, FIG. 2 is a partially omitted enlarged longitudinal sectional view of the embodiment, and FIGS. 3 and 4 are partially enlarged sectional views of the embodiment. DESCRIPTION OF SYMBOLS 1 ... Valve body, 2 ... Relay tube, 3 ... Valve box, 4 ... Handle, 6 ... Upper valve stem, 7 ... Square shaft part, 8 ... Cap nut, 9 ... Through hole, 10 …… Lower valve stem, 11 …… O-ring,
12 ... connecting joint, 15 ... connecting hole, 16 ... upper connecting part, 18 ... coil spring, 19 ... ball, 20 ... valve stem pipe, 21, 22 ... valve stem member, 23 ... Anti-vibration ring, 24… Valve body, 25… Hole, 26 …… Inlet, 27… Valve hole, 28 …… Exit,
29: Anti-vibration ring, 30: Connection joint, 33: Connection hole, 34: Lower connection part, 36: Coil spring, 37, 38 ...
Anti-vibration ring, 39 …… Cryostat, 40 …… Piping.

Claims (1)

(57) [Scope of request for utility model registration] A valve body is housed in a valve box attached to a lower part of a valve body via a relay pipe, and a valve rod inserted from the valve body through the relay pipe through the relay box to an upper valve rod and a lower valve rod. The upper connecting portion for connecting the upper valve stem and the lower valve stem in a flexible manner is provided inside the valve body, and the lower connecting portion for connecting the lower valve stem and the valve member in a flexible manner is provided in the valve box. , A long-axis needle valve having a spring that exerts a pressing force in the axial direction between the upper valve stem and the lower valve stem of the upper joint and between the lower stem and the valve body of the lower joint, respectively. A vibration isolating ring is attached to each of the outer diameter surfaces of the upper and lower ends of the lower stem, and these are brought into contact with the inner diameter surface of the valve body and the inner diameter surface of the valve box, respectively. Attach anti-vibration rings to the outer diameter surface of the valve body and contact them with the inner surface of the valve box. Anti-vibration device of the long axis type needle valve, characterized in that the.