Gate valve device

A movable member is fitted in the middle in the vertical direction of a valve body core fitting that forms a gate valve body, and the movable member presses an elastic seal member from the inside of the seal member toward a tube inner wall surface located in a direction crossing the direction of insertion of the seal member. The movable member has arms and contact sections. The arms each have a second inclined section for pressing the elastic seal member against the tube inner wall surface upon receiving pressing action from a first inclined section that is formed on a pressing member and changes the direction of pressing. The contact sections are in contact with and press the inside of the elastic seal member. The contact sections of the movable member have recesses having inside the elastic seal member.

This application is the U.S. National Phase under 35 U.S.C. §371 of International Application PCT/JP2006/315589, filed Aug. 7, 2006, which claims priority to Japanese Patent Application No. 2005-231677, filed Aug. 10, 2005. The International Application was published under PCT Article 21(2) in a language other than English.

TECHNICAL FIELD

The present invention relates to a gate valve device and, more particularly, to a gate valve device having a case member which can be attached to a pipe and a gate valve body which is disposed in the case member and can be inserted from a hole formed in a peripheral wall of the pipe into the pipe.

BACKGROUND ART

In the case such that a construction work of a public water supply pipe is executed, a method is employed that without stopping water on the upstream side, passage of water in the pipe is temporarily stopped by using a gate valve device as a non-water-stop pipe water stopping device while maintaining a water passing state, and a construction work is performed on the downstream side. After completion of the construction work, the water stop state is cancelled.

Conventionally, the volume of a rubber lining in a valve body used as the non-water-stop pipe water stopping device tends to be large. The reason is that since the valve body of a pipe water stopping device is inserted in a buried pipe through which water is passing to stop water, positioning between a bore hole and the valve is necessary at a site. To reliably interrupt the flow of water, the volume of the rubber lining has to be large. That is, stopping of water in a pipe depends on elasticity of the rubber lining.

Pipes in which the no-water-stop pipe water stopping device is installed include a pipe buried and used for long time and a relatively new pipe and the like. The inside diameters of pipes having the same outside diameter are usually different from each other according to the kinds of the pipes. As a result, the volume of the rubber lining has to be increased to enhance the cutoff performance.

To reliably stop water in a pipe at a site, the following conditions have to be satisfied, and the balance has to be adjusted.

(1) The compression force of the rubber lining in the bottom of a valve body and the bottom of the inner face of the pipe is allowed to act.

(2) The compression force of the rubber lining on the side face of the valve body and the side face in the pipe is allowed to act.

(3) The bore hole is closed by an upper part of the valve body.

The conditions (1) and (2) can be satisfied to some extent by increasing the volume of the rubber lining. However, the deformation amount of the valve body increases at the time of cutting off the valve body, and the torque necessary for cutoff since the valve body comes into contact with the pipe bottom until water completely stops tends to increase. When the deformation amount is large, it is difficult to obtain sufficient compressibility with the pipe inner face, so that sufficient cutoff performance cannot be obtained. Consequently, there is a problem such that when the opening/closing operations are repeated, the rubber lining is damaged by the bore hole.

The condition (3) requires to close the bore hole after reliably closing the pipe under the conditions (1) and (2). When the bore hole is closed first, a flange part of the rubber lining comes into contact with the bore hole, the cutoff torque increases, and compression of the valve body rubber lining with the pipe inner face is not transferred. As a result, when the cutoff is further increased, a problem occurs that the rubber lining is damaged by the bore hole.

As described above, the balance among the conditions (1) to (3) has to be adjusted for existing pipes having different inside diameters. For this purpose, a non-water-stop pipe water stopping device having higher cutoff performance is in demand.

The applicant of the present invention has developed the gate valve device disclosed in Patent Document 1. The gate valve device has a spindle and a valve rod to be inserted as a drive shaft into a pipe, and also a movable piece for pressing a seal member against the inner wall of the pipe, so that water can be sufficiently stopped. Moreover, the size in the vertical direction can be made smaller than that of a conventional device (for example, Patent Document 1).

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

However, the conventional gate valve device has a number of parts and its structure is complicated and consequently has a problem of high manufacturing cost. Since pipes having the same outside diameter have different inside diameters according to the kinds of pipes, a gate valve device having a valve body corresponding to the pipe kind has to be prepared and it is uneconomical.

An object of the present invention is to provide a gate valve device having a single valve body which can be adapted to various existing pipes having different inner diameters and having high cutoff performance while realizing low manufacturing cost.

Means for Solving the Problems

The object is achieved by the inventions described in claims. Specifically, as a characteristic configuration of a gate valve device according to the present invention, the gate valve device has a case member which can be attached to a pipe and a gate valve body disposed in the case member and capable of being inserted in the pipe from a hole formed in a peripheral face of the pipe. The gate valve body includes a valve body core fitting, an elastic seal member covering the valve body core fitting, a press member which presses the elastic seal member from the insertion direction to be elastically deformed, when the elastic seal member is inserted in the pipe, a drive shaft formed in a rod shape along the insertion direction to move the press member along the insertion direction, and a movable member fitted in the middle in the vertical direction of the valve body core fitting and pressing, from the inside, the elastic seal member against an inner wall face of the pipe in a cross direction crossing the insertion direction. The movable member is comprised of: an arm having a second inclined section receiving a pressing action from a first inclined section for converting a pressing direction, formed in the press member and pressing the elastic seal member against the inner wall face of the pipe; and a contact section which comes into contact with the inside of the elastic seal member to press the inside. A recess having the elastic seal member on its inner side is formed in the contact section in the movable member.

With the configuration, when the movable member acts to press the elastic seal member in the swelling direction as the press member descends in any of pipes having the same outside diameter and different inside diameters, the elastic seal member existing in the recess in the contact section is effectively pushed and fed, so that the water stopping action can be displayed reliably. However, a complicated structure having a number of parts is not required. Moreover, the clamping torque at the time of stopping water is smaller than that in the conventional technique, so that the water stopping work can be made easier.

As a result, the gate valve device which can be adapted, with a single valve body, to various existing pipes having different inside diameters, having high cutoff performance, and realizing low manufacturing cost can be provided.

Preferably, the recess formed in the contact section in the movable member is formed in a groove shape extending in the vertical direction of the contact section, and has an opening angle at which a cross section of the recess widens toward the inner face of the pipe.

With the configuration, the capacitance of the elastic seal member which is pressed and fed by the movable member can be increased. Thus, water can be stopped by performing the sealing operation more effectively also on existing pipes having different inside diameters.

DESCRIPTION OF REFERENCE NUMERALS

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of a gate valve device according to the present invention will be described in detail with reference to the drawings.FIG. 1shows the structure in a longitudinal section of a main part of a gate valve body (hereinafter, called valve body)1as a component of a gate valve device according to the embodiment.FIG. 2shows the structure in a cross section taken along line A-A ofFIG. 1.FIGS. 3 to 9are longitudinal sections showing processes of attaching the gate valve device to an existing pipe.

The valve body1has a valve body core fitting2, a rubber lining3as an elastic seal member covering a portion in which the valve body core fitting2is in contact with water in the pipe, a slide spindle5as a press member, when the rubber lining3is inserted into the pipe K as shown inFIG. 3, for pressing the rubber lining3from the insertion direction to be elastically deformed, and a drive shaft6formed in a rod shape along the insertion direction so as to move the slide spindle5along the insertion direction.

The valve body1has a structure that the rubber lining3covers the portion downward of a flange2aof the valve body core fitting2that extends in a circumferential shape along the outer periphery of the pipe K. The flange2aof the valve body core fitting2has a function of preventing the rubber lining3from being deformed upwardly of the flange2aso that the rubber lining3is not deformed and pushed off when the rubber lining3is in contact with a pipe and is pressed.

Two right and left openings2bin which a pair of right and left movable pieces4as a pair of right and left movable members are formed in the middle in the vertical direction of the valve body core fitting2. The movable piece4is comprised of an arm4aand a contact section4b. The contact section4bsupports the rubber lining3and its outer peripheral face4b1is in contact with the inside of the rubber lining3. As will be described later, when the slide spindle5is inserted from above into the valve body1, a first inclined section5afor converting the press direction, which is formed in the slide spindle5, comes into contact with an inclined face4a1as a second inclined portion formed at one end of the arm4aof the movable piece4. As the slide spindle5descends, the right and left movable pieces4press the rubber lining3to make the rubber lining3swell in the direction crossing the insertion direction.

The outer peripheral face4b1of the contact section4bof the movable piece4which comes into contact with the rubber lining3is formed in a circular-arc-shaped curved surface shape so that its vertical portion having an area as large as possible can uniformly come into contact with the inner side of the pipe.FIG. 2shows the structure in a section taken along line A-A. The front end of the contact section4bis forked into two directions having an opening angle θ so that the tips are widened. The rubber lining3enters a recess4b2extending in the vertical direction. In this case, the opening angle θ is preferably about 50 to 100° and, more preferably, 60 to 90°. When the opening angle θ is smaller than the range, the amount of the rubber lining3in the recess4b2is small and it is unpreferable. When the opening angle θ is larger than the range, the torque of pressing the slide spindle5is large and it is unpreferable.

The inner face of the recess4b2is formed in a curved face shape. The inner face in the vertical direction has a circular arc shape almost parallel with the outer peripheral face4b1of the contact section4b. As a result, the recess4b2is formed in a groove shape extending in the vertical direction of the contact section4band has the opening angle θ at which its cross section extends toward the pipe inner face.

Further, the front end of the contact section4bis formed in a curved shape. When the rubber lining3is pressed against the inner wall of the pipe, the rubber lining portion in the recess4b2can be smoothly pushed without damaging the rubber lining3. Since the contact section4bis formed in such a shape, when the movable piece4presses the rubber lining3in the swelling direction as the slide spindle5descends in any of pipes K having the same outside diameter and different inside diameters, the rubber lining3in the recess4b2between the contact sections4forked in two directions is effectively pushed. Consequently, even when an existing pipe whose inner diameter is larger than assumed from the outside diameter is used, the rubber lining3is extended and the water stopping action is reliably displayed. Therefore, even when the user encounters an existing pipe having an unexpected inside diameter at a construction site, the user can flexibly handle it. Moreover, the action force of the movable piece4to press the elastic rubber lining3in the swelling direction is sufficient. Therefore, a clamping toque at the time of stopping water is smaller than that in the conventional technique, so that the water stopping work is easier.

The rubber lining3is integrally attached so as to cover a lower part of the flange2aof the valve body core fitting2, and its bottom portion is formed in a circular arc shape so as to be along the inner face of the pipe. The width of the rubber lining3is slightly smaller than the inner diameter of the pipe, so that the valve body1can be smoothly inserted in a pipe.

Referring now toFIGS. 3 to 9, a process of stopping water by attaching the gate valve device including the valve body1to the existing pipe K will be described.

First, a gate valve device A is attached to the pipe K. After that, with a rotating hole saw (not shown) having the outside diameter of 92 to 100% of the inner diameter of the pipe K, a hole is opened in the pipe K. In this case, when the outside diameter of the hole saw is larger than the inside diameter of the pipe K, there is the possibility that a step is formed in the inner face of the pipe at the end of the hole opening operation and the water stopping performance of the valve deteriorates. When the outside diameter of the hole saw is less than 92% of the inside diameter of the pipe K, at the time of stopping water with the valve body1, it becomes necessary to largely deform the rubber lining, and the water stopping performance becomes unstable.

FIG. 3shows the structure in a longitudinal section of a state, viewed from the pipe axis direction, in which the hole opening operation with the hole saw is finished, the hole saw is pulled up, the gate valve device A of the embodiment is attached to the existing water pipe K, and the valve body1is going to be inserted in the pipe.

The gate valve device A has a lower case member11which are halved, an intermediate case member12, and an upper case member13. When the case members11,12, and13are attached to the existing pipe K, the case members11,12, and13are fixed to each other by fixing mechanisms14of bolts and nuts. Between the neighboring case members11,12, and13, a packing15is inserted, thereby obtaining a watertight structure.

On the inside of the case members11,12, and13, the valve body1is disposed. The inner face of the lower end of the valve body1is in contact with a lower end6aof a valve rod6as the drive shaft. By a rotation descending operation of the valve rod6via a screw7, the valve body1is inserted downward, that is, into the pipe K. The upper end6aof the valve rod6can be manually or automatically rotated via a rotation jig (not shown). When the valve rod6is rotated, the valve body1can move in the vertical directions by the screw action of the screw7formed in an upper part of an almost center of the valve body1and a male screw6bformed in the valve rod6.

FIG. 4shows a state where the valve body1descends into the pipe K by the rotation jig and reaches the bottom of the pipe K. In this case, as shown inFIG. 5illustrating the structure in the section taken along line V-V ofFIG. 4, the movable piece4does not act on the rubber lining3, so that the rubber lining3faces the inner diameter D of the pipe K via a gap S.

When the valve rod6is rotated, as shown inFIG. 6, the slide spindle5starts descending via the screw7and, as described above, the first inclined section5aof the slide spindle5comes into contact with an inclined face4a1of the arm4aof the movable piece4. As the spindle5descends, the right and left movable pieces4make the rubber lining3swollen in the crossing direction shown by the arrows, which cross the insertion direction, the rubber lining3comes into contact with the peripheral face in the pipe, and the gap S disappears. The state is also illustrated inFIG. 7showing the structure in cross section taken along line VII-VII ofFIG. 6.

By further rotating the valve rod6, as shown inFIG. 8, the slide spindle5descends. Until the swollen rubber lining3presses the inner face of the pipe K and is compressed, the right and left movable pieces4move in the swelling direction. As shown inFIG. 9illustrating the structure in cross section taken along line IX-IX ofFIG. 8, the rubber lining3is strongly compressed against the inner peripheral face of the pipe K, so that water can be stopped reliably. In this case, as compared with the conventional technique, the capacity of the rubber lining3which is fed when the movable members4presses the rubber lining3is larger. Consequently, existing pipes having different inner diameters are effectively sealed and an effect capable of stopping water is displayed.

Other Embodiment

(1) In the foregoing embodiment, the recess4b2is formed in a groove shape extending in the vertical direction of the contact section4b, and its sectional face has the opening angle θ at which the recess4b2widens toward the pipe inner face. However, the shape of the recess is not limited to the shape, but may be a shape in which the elastic seal member is held to some extent on the inside of the contact section.