JPH09137868A - Isolation valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an isolation valve capable of perfectly isolating an inner flow passage and small in pressure loss. SOLUTION: An isolation valve 11 consists of a valve casing body 14 having a large diameter part 12 which is a cylindrical valve chest, a sleeve 15 which is provided in the large diameter part 12 and made of the elastic material forming a sealed space 20 between the large diameter part and an inner circumferential surface of the large diameter part 12, a core 16 capable being pressed against the sleeve 15, a supporting member 17 to support the core 16 and presses the sleeve 15 toward the inner circumferential surface of the large diameter part 12, and a tap hole 18 to be communicated with the sealed space 20. Because the pressure fluid is introduced in the sealed space 20, the sleeve 15 is inflated toward the axis of the valve chest in the projected manner to be surely pressed against the core 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutoff valve installed in a gas conduit or a water pipe.

[0002]

2. Description of the Related Art Generally, a gas pipe or a water pipe is provided with a shut-off valve for shutting off an internal fluid flow in an emergency when a leakage accident occurs. There is a type in which a gas bag made of an elastic material that expands and contracts by introducing and depressurizing a pressurized fluid is mounted in a valve box. With a shutoff valve that uses a gas bag, the reaction torque of the operating torque does not occur when opening and closing the valve, unlike when using a general metal valve as the shutoff valve, so it withstands the operating torque reaction force before and after the valve. There is no need to intervene steel pipes, etc., and there is an advantage that it can be easily connected to polyethylene pipes, etc., and installation work costs can be reduced.

A shutoff valve using a gas bag is, for example, the one proposed by the present applicant in Japanese Patent Application No. 7-125492. As shown in FIG. 3, the shutoff valve 1
Is configured by providing a gas bag 3 made of an elastic material such as rubber along the fluid flow direction inside a straight tubular valve box 2 integrally molded of a plastic material (PE) such as polyethylene.

The gas bag 3 is formed in a parasol shape that contracts in a pleated shape, and one end portion 3a thereof has an elbow 4,
The pipe 5 is supported at the axial center of the valve box 2 and communicates with a pressure fluid supply / exhaust pipe 6 for introducing / depressurizing a fluid such as air or nitrogen gas, and the other end 3b is provided with a stiffener 7 The spring 8 provided inside the inner cylinder 7a is supported by the inner cylinder 7a at the axial center position of the valve box 2.
Is pulled in the direction away from the one end 3a.

The pressure / fluid supply / exhaust pipe 6 communicates with an air pump (not shown) or the like, and has an opening / closing valve 9 interposed therebetween. To prevent the flow from wobbling and adversely affecting the flow,
Further, the gas bag 3 is provided so that the gas bag 3 can be quickly and reliably contracted.

In the shut-off valve 1 described above, the gas bag 3 is normally in the contracted posture as shown by the solid line, and fluid such as gas or water flows through the internal flow passage of the valve box 2. On the other hand, when it is necessary to urgently interrupt the flow of fluid such as a leak accident, the air pump is driven and the opening / closing valve 9 is opened, so that air or nitrogen is supplied through the pressure fluid supply / exhaust pipe 6. A pressurized fluid such as gas is introduced into the gas bag 3, and the outer peripheral surface of the gas bag 3 that is swollen quickly by this is brought into pressure contact with the inner peripheral surface of the valve box as shown by the dotted line, and the fluid flow is blocked. To be done.

[0007]

However, in the shut-off valve 1 as described above, the gas bag 3 and the stiffener 7 are present in the valve box 2, so that the fluid passage area becomes small and the pressure loss becomes large. However, PE pipes, which are often used for gas conduits in Japan, are thick and have a small actual inner diameter, and because they are used at low pressure points and pressure loss has a large effect, equipment with small pressure loss must be used. is necessary.

Further, when foreign matter is present on the inner bottom of the valve box 2, the foreign matter may be caught between the inflated gas bag 3 and the inner peripheral surface of the valve box 2 to cause a leak. The gas bag 3 has a problem that a minute leak occurs at the fold and it is difficult to completely shut it off.

The present invention solves the above problems, and an object of the present invention is to provide a shutoff valve capable of completely shutting off the internal flow path and having a small pressure loss.

[0010]

In order to solve the above problems, a shut-off valve of the present invention comprises a valve box main body having a cylindrical valve chamber, and a double tubular structure mounted inside the valve chamber. A closed space is formed between the inner peripheral surface of the valve chamber and the inner peripheral surface of the valve chamber when the peripheral edge of the one side and the peripheral edge of the other side are in pressure contact with each other. A sleeve made of an elastic material, a core arranged concentrically in the valve chamber and press-contacting the sleeve when the sleeve expands, and between the core and the sleeve at one peripheral edge portion and the other peripheral edge portion of the sleeve. A sealing means provided between the sleeve and the inner peripheral surface of the valve chamber, and a support means for supporting the core at one end and pressing the sleeve against the inner peripheral surface of the valve chamber at the other end. The air supply / exhaust means communicating with the space is provided.

Further, the shut-off valve of the present invention is constructed by integrally molding a valve box main body with a plastic material and providing tubular portions forming a flow path on both sides of a large diameter portion forming a valve chamber.

Further, in the shutoff valve of the present invention, the supporting means is provided between the core and the sleeve to maintain the relative position between the core and the stay, and is provided between the core and the stay to press the stay in the radial direction of the valve chamber. And a nut that is screwed to one end of the core and presses the spacer toward the other end of the core. The stay has a diameter that abuts the outer peripheral surface of the spacer at one end. The other end of the directional support portion is provided with a plate-like support portion that is in sliding contact with the sleeve inner peripheral surface that is curved along the inner peripheral surface of the valve chamber.

In the above structure, when the pressurized fluid is introduced into the closed space by the air supply / exhaust means in an emergency, the sleeve expands in a convex shape toward the axial center of the valve chamber and comes into pressure contact with the outer peripheral surface of the core, and the fluid Is cut off.

At this time, even if there is a foreign substance in the valve chamber, it moves downward as the sleeve expands, so that the foreign substance is not caught between the core and the sleeve, and the core and the sleeve are securely pressed against each other. As a result, the flow of the fluid is reliably cut off.

Further, since the valve body has a shape in which the tubular portion forming the flow passage is provided on both sides of the large diameter portion forming the valve chamber, the flow passage cutoff formed between the sleeve and the core in the large diameter portion. The area is about the same as or larger than the flow passage cross-sectional area in the tubular portion and the connecting conduit, and the pressure loss is small enough to be about the same as the connecting conduit.

Further, the core, which has a simple structure including the stay, the spacer and the nut, ensures that a sealed space is formed between the sleeve and the inner peripheral surface of the valve chamber, while the core is provided with a valve chamber suitable for pressure contact with the sleeve. It is held at the axial center position.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a shutoff valve according to an embodiment of the present invention, and FIG. 2 is a partially cutaway front view of the shutoff valve. The shutoff valve 11 is polyethylene (PE)
A tubular part 13 forming a flow path on both sides of a large-diameter part 12 forming a cylindrical valve chamber integrally formed of a plastic material such as
It has the valve box main body 14 provided with.

Inside the large-diameter portion 12, a sleeve 15 integrally molded of an elastic material such as rubber is mounted in a double tubular shape, and a spindle-shaped core 16 is arranged at the axial center position in the fluid flow direction. Support means 17 that supports the core 16 at one end of the sleeve 15 on one side peripheral edge and the other side peripheral edge and presses the sleeve 15 at the other end so as to press the sleeve 15 toward the inner peripheral surface of the large diameter portion 12. , 17 are provided.

A tap hole 18 is provided at an appropriate position substantially in the center of the large diameter portion 12, and a plug 19 covering the tap hole 18 is provided.
Is provided, and through the tap hole 18, the large diameter portion 12
It is possible to communicate the internal space of the above with an air pump (not shown) for sending pressurized gas such as nitrogen gas or air under pressure.

A convex portion 15a is circumferentially formed on the outer peripheral surface of one side peripheral portion and the other side peripheral portion of the cylindrical sleeve 15, and the inner periphery of the large diameter portion 12 facing the convex portion 15a. A groove 12a, which is slightly shallower than the thickness of the convex portion 15a, is circumferentially formed on the surface, and the convex portion 15a of the sleeve 15 is fitted into the groove 12a of the large-diameter portion 12. A sealed space 20 is formed between the outer peripheral surface between 15a and 15a and the inner peripheral surface of the large diameter portion 12. This allows the sleeve 15 to expand and contract when the pressurized fluid is introduced and depressurized in the closed space 20.

The supporting means 17 includes a core 16 and a sleeve 1.
Stays 21 provided over 5 to maintain the relative position of both
And the stay 2 provided between the core 16 and the stay 21.
A conical spacer 2 for pressing 1 in the radial direction of the large diameter portion 12
2 and a nut 23 that is provided by being screwed into one end of the core 16 and presses the spacer 22 toward the other end of the core 16. The stay 21 has a plate shape that is curved along the inner peripheral surface of the large-diameter portion 12 and slidably contacts the inner peripheral surface of the sleeve 15 at the other end of the radial support portion 21 a that abuts the outer peripheral surface of the spacer 22 at one end. The support portion 21b is provided, and in the illustrated example, four stays 21 are arranged at equal intervals in the circumferential direction.

In the valve body 14, the flow passage cross-sectional area formed between the sleeve 15, the core 16 and the support means 17 in the large diameter portion 12 is larger than the flow passage cross-sectional area of the connecting conduit. The diameter of the tubular portion 13 is determined to be the same as that of the connecting conduit, and the material of the valve body 14 is also the same as that of the connecting conduit.

When constructing the shut-off valve 11 as described above, the sleeve 15 made of an elastic material is inserted from the opening of the tubular portion 13 in a folded state, and is widened inside the large-diameter portion 12 and arranged at an appropriate position. , The convex portion 15a of the large diameter portion 1
It fits in the groove 12a of No.2.

Next, while the core 16 is inserted into the large-diameter portion 12 and held at the axial center position, the four stays 21 are sequentially inserted from one end opening of the tubular portion 13 to form the peripheral edge portion on one side of the sleeve 15. Are arranged at equal intervals in the circumferential direction on the four stays 21.
The one end of the core 16 is positioned in the gap between the one ends of the supporting portions 21a.

The supporting portions 21a of the four stays 21 are
Spacer 22 is inserted between one end of core 16 and one end of core 16, nut 23 is screwed onto one end of core 16 and is advanced toward the other end of core 16, Is pressed toward the other end of the core 16, and the wedge action of the spacer 22 caused thereby moves the stay 21 outward in the radial direction. Portion 15a
Is pressed against the groove 12a of the large diameter portion 12.

Similarly, from the other end opening of the tubular portion 13, 4
The stays 21 are sequentially inserted and arranged in the circumferential direction on the other peripheral edge of the sleeve 15, and the other end of the core 16 and the stay 21 # are arranged.
The spacer 22 is inserted between the other end of the support portion 21a and the nut 23 is advanced in the direction toward one end of the core 16, so that the convex portion 15a on the other peripheral edge of the sleeve 15 has a large diameter. The groove 12a of the portion 12 is pressed.

Finally, the plug 19 is attached to the tap hole 18 previously formed in the large diameter portion 12. In the shut-off valve 11 having the above-described structure, when shutting off the flow of fluid, the plug 19 is removed, and pressurized fluid such as air or nitrogen gas is introduced into the closed space 20 by the air supply / exhaust means, as shown by the dotted line. The sleeve 15 is rapidly expanded to the axial center side in a convex shape, and is brought into pressure contact with the outer peripheral surface of the core 16 arranged at the axial center position.

In the shut-off valve 11 as described above, even if foreign matter is present in the large-diameter portion 12, the sleeve 15 and the core 16 move downward as the sleeve 15 expands.
No foreign matter is caught between and, the sleeve 15 and the core 16 are surely pressed against each other, and the flow of fluid is surely blocked.

Further, the valve box main body 14 is formed so that the flow passage cross-sectional area formed between the sleeve 15, the core 16 and the supporting means 17 in the large diameter portion 12 is larger than the flow passage cross-sectional area in the connecting conduit. Therefore, the pressure loss in the shutoff valve 11 becomes almost the same as that in the connecting conduit, and becomes sufficiently small.

Further, since the sleeve 15 is integrally molded in a cylindrical shape and does not have a fold line like the conventional parasol type gas bag, there is no leak at the fold line as in the conventional case, and complete shutoff is achieved. Is done.

[0031]

As described above, according to the shut-off valve of the present invention, the internal flow path is formed by expanding the sleeve in a convex shape toward the axial center and pressing it into contact with the core arranged at the axial center of the valve chamber. Since the shutoff is performed, the foreign matter does not get caught between the core and the sleeve even when foreign matter is present in the valve box, and the core and the sleeve can be sufficiently adhered to each other to reliably shut off the fluid flow.

By forming the valve box main body so that the flow passage cross-sectional area formed between the sleeve and the core in the large-diameter portion is larger than the flow passage cross-sectional area of the connection conduit, the pressure loss of the connection conduit is reduced. It can be about the same and small enough.

The support means having a simple structure including the stay, the spacer, and the nut ensures the formation of a closed space between the sleeve and the inner peripheral surface of the valve chamber, and at the same time, the valve chamber is suitable for press contacting the core with the sleeve. Can be held at the axial center position.

By integrally molding the sleeve into a cylindrical shape so as not to have a fold like a conventional parasol type rubber bag, it is possible to eliminate a leak at a conventional fold and to completely shut it off. Become.

Since the shut-off valve as a whole has a simple shape, it can be manufactured at a very low cost, and if the valve box body is made of the same material as the connecting conduit and has a connecting port of the same diameter, for example, PE is used. When manufactured, the method of connecting PE pipes can be applied as it is, and installation work costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a shutoff valve according to an embodiment of the present invention.

FIG. 2 is a partially cutaway front view of the shutoff valve.

FIG. 3 is a vertical sectional view of a conventional shutoff valve.

[Explanation of symbols]

 11 Shut-off valve 12 Large diameter part (valve chamber) 13 Tubular part 14 Valve box body 15 Sleeve 16 Core 17 Support means 18 Tap hole 20 Sealed space 21 Stay 21a Support part 21b Plate support part 22 Spacer 23 Nut

Claims (3)

[Claims] 1. A valve box main body having a cylindrical valve chamber, and a double-tubular shape mounted inside the valve chamber, the one side peripheral edge portion and the other side peripheral edge portion being on the inner peripheral surface of the valve chamber. A closed space is formed between the inner circumferential surface of the valve chamber and the inner circumferential surface of the valve chamber, and a sleeve made of an elastic material that expands and contracts by introducing and depressurizing a pressure fluid, and is concentrically arranged in the valve chamber. A core that is in pressure contact with the sleeve when the sleeve expands, and is provided between the core and the sleeve at one peripheral edge and the other peripheral edge of the sleeve, and supports the core at one end and the sleeve at the other end. A shut-off valve comprising: a support means for pressing the inner peripheral surface of the chamber so as to be pressed against the inner peripheral surface of the chamber; and an air supply / exhaust means communicating with a sealed space between the sleeve and the inner peripheral surface of the valve chamber. 2. The shutoff valve according to claim 1, wherein the valve box main body is integrally molded of a plastic material, and tubular portions forming a flow path are provided on both sides of a large diameter portion forming a valve chamber. . 3. A stay, wherein the support means is provided from the core to the sleeve so as to maintain the relative position between the core and the sleeve, and a conical spacer provided between the core and the stay to press the stay in the radial direction of the valve chamber. , A nut that is screwed to one end of the core and presses the spacer toward the other end of the core, and the stay includes a radial support portion that abuts the outer peripheral surface of the spacer at one end. The shutoff valve according to claim 1 or 2, further comprising: a plate-shaped support portion that is in sliding contact with the inner peripheral surface of the sleeve that is curved along the inner peripheral surface of the valve chamber.