JPH041416Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a plastic ball valve that is mainly used in transportation piping for gas, water and sewage, etc., and is buried underground. The present invention relates to a plastic ball valve having a safety mechanism and a release prevention mechanism in the cap.

(Prior Art) Conventionally, the opening and closing operations of ball valves, which are mainly buried underground, have been carried out from above ground by attaching a separately prepared long handle (hereinafter referred to as an opener) to the cap of the ball valve. Therefore, the completely open and closed states of the ball valve were confirmed by the direction of the opener or by stopping the rotation of the spindle and cap, and this confirmation was solely by the operator's senses. Therefore, especially with plastic ball valves, if the valve is tightened too much, opened too much, or operated incorrectly, the valve body etc. may be damaged or destroyed, resulting in fluid leakage, and if the fluid is gas, there may be a gas leak or a gas explosion. There was a risk of causing a major accident.

Various safety mechanisms have been devised to solve the above problems, but one of them is a cap that is fixed to a stem that rotates the ball, and a cap that is fitted onto the top of the cap. JP-A-52-37230 discloses a structure in which a shear pin is penetrated at the same time as a wrench adapter.

This shear pin breaks when excessive opening/closing torque is applied to the wrench adapter, thereby acting as a safety mechanism and limiting the torque transmitted to the cap and valve body.

In addition, in order for the above ball valve to open and close smoothly, it is necessary to attach the cap so that it does not separate from the spindle, and the usual method is to fix the cap to the spindle with a set screw. It is used.

(Problems to be solved by the invention) However, when the ball valve disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 52-37230 is used for burying, it has a safety function using a sear pin.
Damage to the valve body due to over-tightening of the valve can be prevented, but once the sear pin as a safety mechanism breaks, the wrench adapter and cap, which are locked only by this sear pin, will separate, so the wrench can be removed using the opener. Even when the adapter is rotated, torque is not transmitted to the cap and stem.
This made it impossible to open and close the ball. Therefore, since it no longer functions as a valve, there is a problem that it cannot respond to emergencies.

In addition, normally the cap is fixed to the spindle by passing a set screw or the like through the cap from the outside of the cap, but if the ball valve is used underground, water and dirt will leak out from this screw. There are problems such as entering the cap, interfering with spindle rotation, and causing rust on metal inserts.

In view of the above points, this invention prevents the safety mechanism and cap from separating from the spindle and main body, which are easily destroyed when opening/closing torque is applied more than necessary, in plastic ball valves that are used buried. The aim is to provide a mechanism to do this.

(Means for Solving the Problems) The structure of the present invention for solving the above problems will be explained with reference to FIGS. 1 to 4, which correspond to embodiments of the present invention. , has a valve chamber 2, a fluid flow path 4a, and a neck portion 3 protruding in a direction perpendicular to the axis of the fluid flow path 4a, and a ball valve body 6 is rotatably mounted in the valve chamber 2. A spindle 9 is connected to the valve body 6, and this spindle 9 is rotatably supported by the neck portion 3 of the valve body 1, and a cap 10 is fixed to the spindle 9 via an adapter 11. A protrusion 11a is provided on the adapter 11, and this protrusion 11
A is designed to come into contact with a stopper part 3a provided on the valve body neck part 3, and is formed to be strong enough to easily break when an excessive opening/closing torque is applied. Further, an annular rib 10a is protruded from the inner circumferential surface of the cap 10, and this annular rib 10a is engaged with an annular groove 3b provided on the outer circumferential surface of the neck portion 3.

As described above, a plastic ball valve is constructed in which the cap 10 is equipped with a safety mechanism and a detachment prevention mechanism.

Possible plastic materials used in the ball valve of the present invention include polyolefin resins such as polyethylene resin, polypropylene resin, polyvinyl chloride resin, and vinylidene fluoride resin, and any of the commonly used materials can be used. Well, it is not particularly limited.

Further, the valve body may be formed by any method such as fusion, adhesion, screwing, or integral molding, and its shape is not limited.

(Function) In the plastic ball valve of the present invention configured as described above, the protrusion 11a provided in the cap 10 rotates the spindle 9 and the ball valve body 6 connected thereto. Following the motion, the valve body 1 comes into contact with a stopper portion 3a provided on the neck portion 3 of the valve body 1, and functions as a so-called stopper, instructing the ball valve body 6 to be in a completely open state or a completely closed state. In addition, if an excessive opening/closing torque is applied to a ball valve that is in a fully open or closed state due to incorrect operation, etc., this protrusion 11a will be easily destroyed and the torque will not be transmitted, resulting in cracks occurring in the valve body 1. It acts as a so-called safety mechanism that prevents damage such as damage or destruction.

Further, since the annular rib 10a protruding from the inner peripheral surface of the lower part of the cap 10 is engaged with the annular groove 3b provided in the neck 3 of the valve body 1 corresponding to the annular rib 10a, the cap 10 cannot be rotated. However, since it does not come off from the neck portion 3 of the valve body 1, there is no problem in opening and closing the valve. That is, the annular rib 10a prevents the valve body 1 from rotating when the cap 10 rotates.
It acts to prevent the neck part 3 from separating from the neck part 3.

(Example) An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. In FIG. 1, A is a valve body made of polyethylene resin, and the valve main body 1 has a valve chamber 2, an end portion 4 having a fluid flow path 4a, and a neck portion 3 protruding perpendicularly to the axis of the fluid flow path 4a. and fluid 5
and a body cap 5 having a
The valve main body 1 and the body cap 5 are fixed and integrated by fusion.

The neck portion 3 is integrally molded into a cylindrical shape at the upper part of the valve main body portion 1, and stopper portions 3a, 3a formed at different levels are provided at the upper end of the neck portion 3, as shown in FIG. , rotatably holds the spindle 9.

These stopper portions 3a, 3a are designed to indicate the fully open state and completely closed state of the ball valve body 6.
It is located in the circumferential direction of the neck portion 3.

6 is a ball valve body made of polyacetal resin and rotatably mounted in the valve chamber 2. The valve main body 1 and the body cap 5 facing the ball valve body 6 are provided with annular protrusions 4b and 5b having an outer diameter smaller than the inner diameter of the valve chamber 2. Seat rings 7 and 8 are fitted into an annular groove having a rectangular cross section provided in 5b.

Reference numeral 9 denotes a spindle made of polyacetal resin, which is rotatably supported by the neck portion 3 of the valve body A as described above, and is supported by an O-ring fitted into an annular groove provided in the spindle itself. It maintains sealing performance with the neck portion 3. The lower end of the spindle 9 is fitted with the ball valve body 6, and its rotation rotates the ball valve body 6 between an open position and a closed position.

Reference numeral 10 denotes a polyethylene resin cap mounted so as to be rotatable together with the spindle 9. An annular rib 10a having a rectangular cross section is protruded from the lower inner circumferential surface of the cap 10, and an annular groove 3 corresponding to the annular rib 10a is provided on the outer circumferential surface of the main portion 3.
b. This fitting of the annular rib 10a into the annular groove 3b is performed in a state where the diameter is temporarily expanded by utilizing the elasticity of polyethylene resin.
Once fitted, the cap 10 can be rotated, but cannot be easily removed from the neck 3.

The cross-sectional shape of the annular rib 10a is preferably polygonal, especially triangular or quadrangular. By having such a cross-sectional shape, the cap 10
When rotating, the effect of preventing separation from the neck portion 3 becomes better.

Further, an annular groove 10b is provided on the inner peripheral surface of the cap 10 below the annular rib 10a, and an O-ring 12 is fitted into this groove 10b to maintain a seal between the neck 3 and the cap 10. has been done.

Reference numeral 11 denotes an adapter made of copper alloy, which is integrated into the cap 10 by insert molding, and is fitted and fixed to the upper end of the spindle 9 so that it can rotate together with the spindle 9. Therefore, cap 10 is adapter 1
Since the cap 10 is engaged with the spindle 9 through the cap 1, when the cap 10 is rotated, the adapter 11 and the spindle 9 are also rotated at the same time, and the ball valve body 6 is also rotated accordingly.

In addition to the above-mentioned insert molding, methods for attaching the adapter 11 into the cap 10 include a simple fitting method or a method using adhesive, but any method may be used and is not particularly limited.

As shown in FIGS. 3 and 4, the adapter 11 has one protrusion 11a integrally formed on the peripheral edge of its lower end surface. This protrusion 1
1a has a fan-shaped cross section and comes into contact with the stopper portion 3a of the valve body neck 3 when the valve is fully open and completely closed, and serves to notify the operator of the open/closed state of the valve. Further, the breaking strength of the protrusion 11a is smaller than that of the valve body A, and when the valve is fully open or completely closed, an excessive opening/closing torque is applied to the stopper portion 3a of the valve body neck 3 due to an erroneous operation or the like. It is designed to be so strong that it can sometimes be broken from its roots. Normally, the opening/closing torque value of the cap 10 is set at around 500 kgf-cm at the highest, so the breaking torque value of this protrusion 11a is set at 1000~1000 kgf-cm, depending on the diameter of the ball valve, for safety reasons.
It is preferable to set it to about 2000Kgf-cm.

Note that the protrusion 11a is directly inserted into the cap 10,
They may be provided integrally by integral molding, insert molding, or adhesive, and the number is at least 1.
Although the number is not limited, it is preferable to provide one or two. Also protrusion 1
The cross section of 1a may have any shape such as a circular shape or a rectangular shape in addition to the above-mentioned fan shape.
Considering the state of contact with a, it is preferable to have a fan shape. Further, the material of the protrusion 11a is not specified as long as it is strong enough to break from its base when an excessive torque is applied as described above, and it may be made of plastic or metal.

The operation of this embodiment configured as described above will be explained.

When the cap 10 is rotated by a cap opener (not shown), the spindle 9 and the ball valve body 6 are also rotated at the same time via the adapter 11 which rotates at the same time. Further, due to the rotation of the cap 10, the protrusion 11a provided on the adapter 11 comes into contact with the stopper portion 3a of the valve body neck portion 3, and the ball valve body 6 is placed in a completely open state or a completely closed state. In this state, the valve body neck 3
If an excessive opening/closing torque is applied to the stopper portion 3a due to an erroneous operation or the like, the protrusion 11a will be broken from its base.

However, even in this state, the cap 10 and spindle 9 are connected to each other via the adapter 11 so that they can rotate together, so the ball valve body 6 can be rotated by the same operation as described above. This allows the valve to continue to be opened and closed easily.

In addition, since the protrusion 11a after being broken remains within the stepped portion of the valve body neck portion 3, it does not interfere with the opening/closing operation of the valve.

Further, the cap 10 is rotatably connected to the neck 3 of the valve body by fitting an annular rib 10a protruding from the inner peripheral surface of the lower part into an annular groove 3b provided on the outer peripheral surface of the valve body neck 3. ing. This fitting is such that it cannot be separated, and even if the cap 10 is rotated, it will not separate from the neck portion 3, so that the opening and closing operations of the valve can be easily performed without any trouble.

A second embodiment of the present invention is shown in FIGS. 5 and 6.

In this embodiment, a stopper pin 14 corresponding to the protrusion 11a is integrally provided directly on the cap 13. Further, an annular rib 13a having a triangular cross section is provided on the lower inner peripheral surface of the cap 13 to protrude inwardly, and an annular groove 13b into which the sealing O-ring 12 is fitted is provided below the annular rib 13a. ing.

The operation of this embodiment is similar to that of the first embodiment, so the explanation thereof will be omitted.

(Effects of the invention) As described above, the invention allows the protrusion provided inside the cap to be easily destroyed by excessive opening/closing torque, thereby avoiding transmission of this torque to the valve body. This prevents damage such as cracking or destruction of the valve body, and serves as a safety mechanism. Therefore, when the fluid is gas, for example, major accidents such as gas leaks and gas explosions can be prevented from occurring.

Further, even after the protrusion is destroyed, the ball valve body can be opened and closed, so that it is possible to respond easily and quickly in an emergency.

Furthermore, since the cap is rotatably fixed to the neck of the valve body through an annular rib formed on its inner circumferential surface, water and dirt from the set screw etc. This prevents metal from entering the cap, which does not interfere with the opening and closing of the spindle, and also prevents corrosion of metal inserts in the cap.

Further, since the cap is firmly fixed to the neck of the valve body as described above, it does not come off when the cap is rotated, and the opening and closing operations can be easily performed.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the first embodiment of the present invention, and the second
The figure is an exploded perspective view with a part cut away of the same example as above.
Fig. 3 is a perspective view of the adapter in the above embodiment, Fig. 4 is a bottom view of the above adapter, Fig. 5 is an enlarged vertical sectional view of the cap in the second embodiment of the present invention, and Fig. 6 is a bottom view of the same cap. It is a diagram. A... Valve body, 1... Valve main part, 2...
... Valve chamber, 3... Neck, 3a... Stopper part, 4
... end, 4a ... fluid flow path, 5 ... body cap, 6 ... ball valve body, 9 ... spindle, 1
0, 13...Cap, 10a, 13a...Annular rib, 11...Adapter, 11a...Protrusion, 1
4... Stopper pin.

Claims (1)

[Claims for Utility Model Registration] 1. A valve body having a valve chamber, a fluid flow path, and a neck protruding in a direction perpendicular to the axis of the fluid flow path, and a ball valve body rotatably mounted within the valve chamber. a spindle connected to the ball valve body and rotatably supported on the neck of the valve body; and a cap mounted on the neck of the valve body so as to be rotatable at the same time as the spindle;
In the plastic ball valve in which the ball valve element opens and closes the fluid flow path by rotation of the cap, the cap includes:
A protrusion that comes into contact with a stopper provided on the neck of the valve body and is easily destroyed when an excessive opening/closing torque is applied is provided, and an annular rib is provided on the inner peripheral surface of the cap, and the annular rib is A plastic ball valve characterized by engaging an annular groove provided on the outer peripheral surface of the neck. 2. The plastic ball valve according to claim 1, wherein the protrusion is provided on an adapter fixed within the cap. 3. The plastic ball valve according to claim 1, wherein the protrusion is provided directly on the cap. 4. The plastic ball valve according to claim 1, wherein the annular rib protruding from the inner peripheral surface of the cap has a polygonal cross section.