JPH08121618A - Diaphragm valve - Google Patents

Abstract

PURPOSE: To provide a diaphragm valve free from causing a dispersion in the tightening strength of bolts when a diaphragm is fitted to a pressing body. CONSTITUTION: In a diaphragm valve where a head part of a bolt 21 is embedded in a bolt fitting part of a diaphragm 2, a tip part of the bolt 21 is screwed into a female screw part 61 of a pressing body 6, and a flow passage 13 is opened/closed by the elevation/lowering of a center part of the diaphragm through the elevation/lowering of the pressing body 6, a stopper is provided on the head part side of the bolt 21, and the stopper face facing the tip side of the bolt of the stopper is abutted on the surface around the female screw part 61 of the pressing body 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm valve, and more particularly, it is intended to prevent variations in tightening of bolts when the diaphragm is attached to a pressing body, prevent damage to the diaphragm, and improve water blocking performance.

[0002]

2. Description of the Related Art For example, as described in Japanese Utility Model Publication No. 63-40702, a bolt head is embedded in a bolt mounting portion of a diaphragm, and a tip portion of the bolt is screwed into a female screw portion of a pressing body. There is known a diaphragm valve in which a flow path is opened and closed by raising and lowering a central portion of the diaphragm by raising and lowering a pressing body.

In such a diaphragm valve, the sleeve is rotated by rotating a handle provided above the valve, the valve stem is moved up and down by the rotation of the sleeve, and the valve stem is mounted below the valve stem by moving up and down. The pressed body moves up and down, and the diaphragm moves up and down as the pressure body moves up and down to open and close the flow path.

[0004]

However, in the conventional diaphragm valve, there is variation in tightening the bolt when the diaphragm is attached to the pressing body, and if the bolt is excessively tightened, the water stopping property is poor and the diaphragm is damaged. , The bolt may come off the diaphragm, and if the bolt is tightened too much, the diaphragm may come off the pressing body.

The present invention has been made in view of such problems in the conventional diaphragm valve,
It is an object of the present invention to solve the above-mentioned problems and to provide a diaphragm valve in which variation in tightening of bolts when mounting the diaphragm to the pressing body does not occur.

[0006]

In order to achieve the above object, in the diaphragm valve of the present invention, the head portion of the bolt is embedded in the bolt mounting portion of the diaphragm, and the tip portion of the bolt is in the female thread portion of the pressing body. In a diaphragm valve that is screwed in and the flow path is opened and closed by raising and lowering the center of the diaphragm by raising and lowering the pressing body, a stopper is provided on the head side of the bolt, and the stopper surface facing the bolt tip side of the stopper has a female thread portion of the pressing body. It is characterized in that it is in contact with the surrounding surface.

In the present invention, the material of the diaphragm valve is not particularly limited, but for example, iron, aluminum, hard vinyl chloride resin, ABS resin, PVD
Using F resin, PPS resin, PEEK resin, etc.
Alternatively, they can be used in an appropriate combination.

[0008]

In the diaphragm valve of the present invention, the stopper is provided on the head side of the bolt, and the stopper surface of the stopper facing the bolt tip side is in contact with the surface of the pressing body around the female screw portion. If the bolt is tightened enough when it is attached to the body, the stopper surface is in contact with the surface around the female screw part of the pressing body, and the bolt cannot be tightened any more, and the bolt cannot be tightened excessively. . Further, by tightening the bolt sufficiently until its stopper surface comes into contact with the surface around the female screw portion of the pressing body, the tightening of the bolt does not become excessive.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a front view showing an example of a diaphragm valve of the present invention in a right half portion in section, and FIG. 2 is an enlarged sectional view of an essential part of the diaphragm valve of the present invention shown in FIG.

In these drawings, reference numeral 1 is a hard vinyl chloride resin valve body of the diaphragm valve of the present invention,
A wear portion 11 is provided in the center of the valve body 1, and a bonnet 3 is attached to the diaphragm attachment seat 12 so as to sandwich the peripheral edge of the diaphragm 2. A sleeve 4 having an internal thread on its inner surface is rotatably attached to the bonnet 3 at that position, and the valve stem 5 can be moved up and down by being screwed into the sleeve 4.

A glass fiber-filled polypropylene pressing body 6 is attached to the lower end of the valve stem 5.
, A head portion of a steel bolt 21 is embedded in a bolt mounting portion substantially at the center of the diaphragm 2, a steel female screw portion 61 of a pressing body 6 is screwed onto the tip of the bolt 21, and the diaphragm 2 is fixed. When 7 is turned, the diaphragm 2 moves up and down, opens and closes with the wear section 11, and opens and closes the flow path 13.

A large-diameter stopper 2 is provided on the head side of the bolt 21.
11 is provided, and the stopper surface 212 of the stopper 211 facing the bolt tip side is in contact with the surface of the pressing body 6 around the female screw portion 61.

A male screw shaft 51 is projectingly provided on the upper end of the valve stem 5 in the axial direction, and a stop ring 8 is fitted on the male screw shaft 51. Although the male screw shaft 51 has a female screw hole provided at the upper end portion of the valve stem 5 by tapping and screwed into the female screw hole, the upper portion of the valve stem 5 has a small diameter. The part may be provided with a male screw.

The cylindrical retaining ring 8 has an outer diameter larger than the diameter of the valve stem 5, is fitted to the male screw shaft 51, and has a packing 8 between the outer surface of the retaining ring 8 and the inner surface of the sleeve 4.
It is sealed by 1. The sleeve 4 is provided with a step portion 41 with which the stop ring 8 abuts. This step 4
1, the lower end surface of the stop ring 8 abuts at a position where the valve stem 5 is pushed down and the diaphragm 2 is pressed by the wear portion 11 to close the valve.

A stop ring 8 is fitted on the male screw shaft 51, and an indicator 9 is screwed on the tip thereof. The indicator 9 has a female screw member 92 having a slit 93 provided in the synthetic resin cylindrical body 91 in the axial direction and is press-fitted integrally with the slit narrowed.
Is tightly screwed with the male screw shaft 51, and the indicator 9 is prevented from loosening.

If the outer surface of the female screw member 92 is knurled or the like, the female screw member 92 and the synthetic resin cylindrical body 91 are more closely integrated. Further, when a flange 94 is projected from one end of the female screw member 92 and the flange 94 is in contact with the end surface of the synthetic resin cylindrical body 91, the degree of press-fitting of the female screw member 92 into the synthetic resin cylindrical body 91 is made constant. It is possible and preferable.

The female screw member 92 may be made of synthetic resin, but is preferably made of metal. Further, the female screw member 92
It is preferable that two or more slits are evenly arranged. Of course, the synthetic resin cylindrical body 91 may be a cap shape with one end closed, and the closed portion is provided with a recessed portion such as a screwdriver or a hexagonal wrench for fitting, and the indicator 9 is screwed. The degree of conformity may be adjusted. Reference numeral 42 is an annular groove provided in the sleeve 4, and a split ring 43 is fitted in the groove 42 so that the split ring 43 does not spread.
4 is fitted. By thus fitting the split ring 43 into the sleeve 4, the sleeve 4 will not fall into the bonnet 3 even when the handle 7 is removed.

By adjusting the degree of screwing of the indicator 9 onto the male screw shaft 51, the mounting position of the retaining ring 8 can be adjusted, and the pressing force between the diaphragm 2 and the wear portion 11 can be adjusted by the lower surface portion of the retaining ring 8 and the sleeve 4. It can be made constant by contact with the stepped portion 41 of. Diaphragm 2 and wear part 11
When the water resistance is deteriorated due to wear or damage, the valve stem 5 can be pushed down by just returning the degree of screwing of the indicator 9 to the male screw shaft 51, and the water resistance can be restored.

[Operation of Embodiment] In the diaphragm valve of the present invention shown in FIGS. 1 and 2, the stopper 211 is provided on the head side of the bolt 21, and the stopper surface 212 of the stopper 211 facing the tip side of the bolt 21 is pressed. Since it is in contact with the surface of the body 6 around the female screw portion 61, when the bolt 21 is sufficiently tightened when the diaphragm 2 is attached to the pressing body 6, the stopper surface 212 causes the female screw portion 6 of the pressing body 6.
1. The bolt 21 is abutted against the surrounding surface and the bolt 21 cannot be tightened any more.
I can't tighten 1. Further, the bolt 21 is sufficiently tightened until the stopper surface 212 thereof comes into contact with the peripheral surface of the female screw portion 61 of the pressing body 6, so that the tightening of the bolt 21 does not become too small.

Although the embodiments of the present invention have been described above with reference to the drawings, the configuration of the present invention is not limited to the illustrated embodiments, and design changes within the scope of the present invention are included in the present invention. Be done. For example, in the illustrated embodiment, the female screw portion 61 is embedded in the body separately from the body of the pressing body 6, but the female screw portion 61 may be integrated with the body of the pressing body 6. .

[0021]

According to the diaphragm valve of the present invention,
Since the stopper is provided on the head side of the bolt and the stopper surface of the stopper facing the bolt tip side is in contact with the surface around the female screw part of the pressing body, tighten the bolt sufficiently when mounting the diaphragm to the pressing body. And the stopper surface is in contact with the surface of the pressing body around the female screw part, and the bolt cannot be tightened any further.
You cannot overtighten the bolts. Further, by tightening the bolt sufficiently until its stopper surface comes into contact with the surface around the female screw portion of the pressing body, the tightening of the bolt does not become excessive.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a diaphragm valve of the present invention in a right half section.

FIG. 2 is an enlarged cross-sectional view of essential parts of the diaphragm valve of the present invention shown in FIG.

[Explanation of symbols]

 1 Valve body 11 Wear part 12 13 Flow path 2 Diaphragm 21 Bolt 211 Stopper 212 Stopper surface 3 Bonnet 4 Sleeve 5 Valve stem 6 Pressing body 61 Female screw part 7 Handle 8 Stop ring 9 Indicator

Claims (1)

[Claims] 1. A head portion of a bolt is embedded in a bolt mounting portion of a diaphragm, a tip portion of the bolt is screwed into an internal thread portion of a pressing body, and a passage is opened and closed by raising and lowering a central portion of the diaphragm by raising and lowering the pressing body. In the diaphragm valve, a stopper is provided on the head side of the bolt, and the stopper surface of the stopper facing the bolt tip side is in contact with the surface around the female screw part of the pressing body.