JPH0799225B2 - Over-tightening device for valves - Google Patents

Description

TECHNICAL FIELD The present invention relates to a valve overtightening prevention device suitable for use in pipelines for agricultural and marine equipment, water treatment equipment, building equipment, plant equipment, waterworks, and the like.

[Prior Art] As a conventional valve, a valve box having a fluid flow path is coupled to a valve box while rotating with respect to the valve box but not moving in its own axis direction,
A valve rod having a male screw portion for a valve disc in a portion located in the valve box, and a female screw portion screwed to the male screw portion of the valve rod,
An operation that is supported in a state that it moves in the axial direction of the valve stem with respect to the valve stem but does not rotate, and that is fixed to the valve body that opens and closes the fluid flow path of the valve stem and the portion of the valve stem that is located outside the valve stem. What has a member and is used.

In the above valve, when the valve rod is rotated by the rotation operation of the operating member, the valve body screwed to the male thread portion for the valve body of the valve rod moves to open and close the fluid passage.

Meanwhile, in the above-mentioned valve, from the viewpoint of ensuring corrosion resistance, there is a valve in which at least the valve box and the valve body that define the fluid flow path are formed of a synthetic resin material such as PVC.

[Problems to be Solved by the Invention] However, in a valve in which the valve box and the valve body are formed of a synthetic resin material, the material strength of the synthetic resin material is weaker than that of metal, so that the valve shutoff may occur. When an excessive force is applied to the contact portion between the valve box and the valve body due to an excessive closing operation, the valve box or the valve body may be damaged.

Therefore, in Japanese Utility Model Laid-Open No. 61-117970, as a means for solving the above-mentioned problems, a fully-closed positioning stopper is screw-fitted to a rotary operation shaft interlocked with a sliding valve body, and the rotary operation is performed on the stopper. The rotation stopper, which is engaged so as to allow only the shaft to slide in the longitudinal direction, is fixed to the valve box, and the contact portion that defines the sliding limit position of the stopper according to the closing operation of the rotation operation shaft is described above. The one provided in the valve box is disclosed. However, in order to adjust the position of the sliding valve body with respect to the valve box when the stopper comes into contact with the contact portion, the fixed phase around the rotation operation axis of the rotation stopper is changed to adjust the stopper to the rotation operation axis. Since it is a fine adjustment of the mounting position, you must disassemble the rotation stopper and adjust it,
There is a problem that the adjustment work is troublesome.

The present invention reliably prevents overtightening at the time of valve shutoff, protects the valve box and valve body made of synthetic resin material from excessive shutoff force, and easily adjusts the overtightening prevention position without disassembling the valve. The purpose is to be able to.

[Means for Solving the Problems] The present invention includes a valve box having a fluid flow path and a valve chamber, and an intermediate flange portion that is coupled to the valve box while rotating with respect to the valve box but not moving in its own axial direction. A valve rod having an external thread portion for the valve disc in a portion located in the valve chamber of the valve box, and an internal thread portion screwed to the external thread portion of the valve rod, and the valve rod with respect to the valve box. A valve body that is supported in a state that it moves in the axial direction but does not rotate and that opens and closes the fluid flow path of the valve box, and an operation member that is fixed to a portion of the valve rod that is located outside the valve box In the valve overtightening prevention device, in which at least the valve box and the valve body are formed of a synthetic resin material, in the valve rod, the portion provided outside the valve chamber of the valve box is provided for the male thread for the valve body. It is screwed onto the male thread for over-tightening, which is a reverse screw, and is moved in the axial direction of the valve stem by the guide that is integrated with the valve box. It is guided in a state that it moves but does not rotate, and it is locked to the overtightening prevention ring that moves in the direction opposite to the valve body when opening and closing the valve, and the above overtightening prevention male screw part so that position adjustment is possible, and when the valve is fully closed, An overtightening adjustment nut with which the above-mentioned overtightening prevention ring abuts is provided.

[Operation] According to the present invention, when the valve rod is rotated by the operating member, the valve body screwed to the male thread portion for the valve body of the valve rod moves, and the fluid passage of the valve box is opened and closed. To be

At this time, the overtightening prevention ring screwed to the male threaded portion for preventing overtightening of the valve rod moves in the direction opposite to the valve body. And
Simultaneously with the completion of the cutoff in which the valve body abuts the inner surface (valve seat) of the fluid flow path, the overtightening prevention ring abuts the overtightening adjustment nut locked to the male thread portion for preventing overtightening of the valve rod. For this reason, if the operation member over-tightens after completion of the shut-off, the over-tightening prevention ring and the over-tightening adjustment nut firmly abut without damage, and further rotation of the valve rod and movement of the valve element are ensured. Prevent.

Since the above-mentioned over-tightening adjustment nut is locked to the male thread for preventing over-tightening of the valve rod so that the position can be adjusted, over-tightening adjustment for the male thread for preventing over-tightening of the valve rod can be performed without disassembling the valve. By adjusting the screwing position of the nut, the timing at which the overtightening prevention ring collides with the overtightening adjustment nut when the valve is closed can be adjusted, and as a result, the overtightening prevention position can be easily adjusted. Therefore, proper overtightening prevention can be realized.

As a result, overtightening at the time of valve shutoff can be reliably prevented, and the valve box and the valve body made of a synthetic resin material can be protected from an excessive shutoff force.

[Embodiment] FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 is a perspective view showing a main part of the drawing, and FIG. 3 is a plan view showing an overtightening prevention ring.

The valve 10 has a valve box 11, a valve rod 12, a valve body 13, and a cap (operating member) 14.

The valve box 11 includes a housing 15, a lower bonnet 16, a valve stem support plate 17, and an upper bonnet 18, and a plurality of fixing bolts.
It is configured to be tightened together at 19. Incidentally, among the fixing bolts 19, some of the fixing bolts are fixing three members except the upper hood 18. The housing 15 has a fluid flow path 15
The valve chamber 15B is formed while forming A.

The valve rod 12 has an intermediate flange portion 12A held between a lower bonnet 16 and a valve rod receiving plate 17, and is connected to the valve box 11 while rotating but not moving in its own axial direction. Valve rod 12
Is provided with a male threaded portion 12B for a valve body at the lower end located inside the valve box 11 (valve chamber 15B of the housing 15). 20A, 20
B and 20C are O-rings.

The valve body 13 shown in the embodiment is of a so-called soft seal type, and the female thread nut (female thread portion) 21 screwed to the male thread portion 12B of the valve rod 12 is attached to the valve body body portion 13A. To prepare for one. A groove for accommodating a T-shaped elastic packing is formed in the outer peripheral surface of the valve body 13A in the circumferential direction and the axial direction. Further, the valve body 13 is a housing 15
Engaging projection 23 that slidably engages with a guide groove 22 provided along the axial direction of the valve rod on the inner surface facing the valve chamber 15B.
Equipped with. As a result, the valve body 13 is coupled to the valve box 11 in a state in which it moves in the axial direction of the valve stem but does not rotate.
That is, the valve body 13 moves up and down in the valve rod axial direction when the valve rod 12 rotates, and opens and closes the fluid flow path 15A of the housing 15. Although not shown, the lower end surface of the valve body 13 is provided with a through hole penetrating the elastic packing. The through hole serves to adjust the pressure inside the valve body.

The cap 14 is fixed to the upper end located outside the valve rod 12, and the box spanner can be attached and detached.

Further, the valve rod 12 is provided with a stopper portion 25 on the lower end side of the intermediate flange portion 12A. The stopper portion 25 has a diameter larger than the outer diameter of the male screw portion 12B, and is located at the fully open position.
The upper end surface of the 13 female screw nut 21 is adapted to abut. When the female screw nut 21 and the stopper portion 25 collide with each other, a constant gap is maintained between the lower bonnet 16 and the valve body main body portion 13A. The diameter of the intermediate flange portion 12A of the valve rod 12 is equal to or larger than the diameter of the abutting portion 25.

In the above valve 10, the housing 15, the lower bonnet 16, the upper hood 18, and the valve body 13 which form the valve box 11 are made of a synthetic resin material such as PVC from the viewpoint of ensuring corrosion resistance. I am configuring. The valve rod 12, the valve rod receiving plate 17, and the female screw nut 21 are made of metal.

However, the valve rod 12 is provided with a male screw portion 12C for overtightening which is provided in a portion of the valve box 1 located outside the valve chamber 15B and forms a reverse screw with the male screw portion 12B for the valve body. The thread pitch of the male thread portion 12C is finely set to, for example, 1/10 to 1/3 as compared with the thread pitch of the valve body male thread portion 12B.

In addition, as shown in FIG.
A metal overtightening prevention ring 30 is screwed on. The overtightening prevention ring 30 is preferably made of metal, but synthetic resin such as FRP or engineering plastic can also be used as long as it has excellent mechanical strength such as compression strength. As shown in FIG. 3, the overtightening prevention ring 30 is provided with a concave groove 31 on its outer peripheral portion, and the concave groove 31 is engaged with a convex guide portion 32 provided in the axial direction of the inner peripheral portion of the upper bonnet 18. is doing. That is, the overtightening prevention ring 30 is guided by the ridge guide portion 32 in a state where it moves in the axial direction of the valve rod 12 but does not rotate, and moves in the direction opposite to the valve body 13 when the valve is opened and closed.

Further, a metallic overtightening adjustment nut 33 is screwed on the upper end side of the overtightening preventing male screw portion 12C. The overtightening adjustment nut 33 is composed of a double nut, and is locked to the overtightening preventing male screw portion 12C so as to be positionally adjustable. As a result, the overtightening adjustment nut 33 is set so that the overtightening prevention ring 30 abuts when the valve is fully closed.

Next, the operation of the above embodiment will be described.

According to the above-described embodiment, when the valve rod 12 is rotated by the cap 14, the valve body 13 screwed to the male thread portion 12B for the valve body of the valve rod 12 moves, and the fluid flow path of the valve box 11 moves. 15A can be opened and closed.

At this time, the over-tightening prevention ring 30 screwed to the over-tightening prevention external thread portion 12C of the valve rod 12 moves in the direction opposite to the valve body 13. Then, at the same time when the closing of the valve body 13 in contact with the inner surface (valve seat) of the fluid flow path 15A is completed, the overtightening prevention ring 30 becomes
Butt against the over-tightening adjustment nut 33 locked to the over-tightening prevention male thread 12C of 12. Therefore, when the cap 14 is overtightened after the shutoff is completed, the overtightening prevention ring 30 and the overtightening adjustment nut 33, which are a combination of metals, are firmly abutted with each other without being damaged, and the valve rod 12 is further tightened. The rotation and the movement of the valve body 13 are reliably prevented.

The overtightening adjustment nut 33 is locked to the male screw portion 12C for preventing overtightening of the valve rod 12 so that the position can be adjusted. Therefore, even if the valve 10 is not disassembled, the male screw for overtightening prevention of the valve rod 12 is prevented. By adjusting the screwing position of the overtightening adjustment nut 33 with respect to the portion 12C, the timing at which the overtightening prevention ring 30 abuts the overtightening adjustment nut 33 when the valve is closed can be adjusted, and as a result, the overtightening prevention position can be easily adjusted. Can be adjusted. Therefore, proper overtightening prevention can be realized.

As a result, overtightening at the time of valve shutoff can be reliably prevented, and the valve box 11 and the valve body 13 made of a synthetic resin material can be protected from excessive shutoff force.

In the practice of the present invention, the operation member is not limited to the cap,
It may be a handle or the like.

Further, in the present invention, the valve body is not limited to the soft seal type shown in the embodiment, and for example, a shell made of a heat-resistant hard synthetic resin (for example, chlorinated PVC resin) or a metal such as cast iron. The outer surface of the core body may be integrally covered and bonded with an elastic body such as rubber.

Further, the both-ends connecting portion of the valve box may be of a rubber ring type used in the field of synthetic resin sewer pipes or the like, in addition to the flange type. Further, one may be a flange type and the other may be a rubber ring type. Further, it may be an adhesive type or a screw joint type.

Further, the overtightening adjustment nut 33 does not need to be a double nut, and may be a simple nut having a predetermined thickness. In this case, pre-position the nut so that its upper end surface contacts the lower end surface of the cap 14, and screw it onto the male thread 12C for the valve disc, and then fix the cap 14 to the upper end of the valve rod. Good. Then, the position adjustment for preventing over-tightening may be performed by exchanging with a nut having a different thickness.

[Effects of the Invention] As described above, according to the present invention, it is possible to reliably prevent overtightening at the time of valve shutoff, and protect the valve box and the valve body made of a synthetic resin material from excessive shutoff force. Furthermore, since the overtightening prevention ring screwed onto the male thread for preventing overtightening of the valve rod is screwed on the reverse thread to the male thread for valve body,
It moves in the direction opposite to the valve body. When the valve body is completely shut off, the overtightening prevention ring abuts the overtightening adjustment nut that is locked by the male threaded portion for preventing overtightening of the valve stem, ensuring rotation of the valve stem and movement of the valve body. Since the screwing position of the overtightening adjustment nut can be adjusted without disassembling the valve, it is possible to easily adjust the timing at which the overtightening prevention ring abuts the overtightening adjustment nut when the valve is closed.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 is a perspective view showing a main part of the drawing, and FIG. 3 is a plan view showing an overtightening prevention ring. 10 …… Valve, 11 …… Valve case, 12 …… Valve rod, 12A …… Intermediate flange, 12B …… Valve male thread, 12C …… Overtightening male thread, 13 …… Valve , 14 ... Cap (operating member), 15A ... Fluid flow path, 15B ... Valve chamber, 17 ... Valve rod receiving plate (abutting member), 30 ... Overtightening prevention ring, 33 ... Overtightening adjustment nut.

Claims (1)

[Claims] 1. A valve box having a fluid passage and a valve chamber, and an intermediate flange portion which is coupled to the valve box while rotating with respect to the valve box but not moving in its own axis direction. It has a valve rod with a male thread for the valve disc at the part located at and a female thread that is screwed to the male thread of the valve rod. A valve body that is supported in a non-slip state and that has a valve body that opens and closes the fluid passage of the valve box and an operation member that is fixed to a portion of the valve rod that is located outside the valve box. In a valve over-tightening prevention device made of a synthetic resin material, an over-tightening prevention device that is provided in a portion of the valve rod outside the valve chamber and forms a reverse screw with the male thread for valve body A state in which it is moved in the axial direction of the valve rod but is not rotated by the guide part that is screwed to the male thread of the valve and integrated with the valve box. The overtightening prevention ring that is guided and moves in the direction opposite to the valve body when opening and closing the valve is locked to the above overtightening prevention male thread so that the position can be adjusted, and the above overtightening prevention ring abuts when the valve is fully closed. A valve overtightening prevention device comprising an overtightening adjustment nut.