JPH10274346A - Gate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of displacement of a seal member, which contacts with a top surface of an enlarged diameter part of a core, in the direction for separating from the center, and to facilitate the drawing of a valve element by forming a top surface of the enlarged diameter part, which is provided opposite to the inserting direction toward a through hole, into a taper surface inclined toward the center and a lower end of a valve element. SOLUTION: A circular rod type core 16 is provided in a lower end of a valve rod, and an enlarged diameter part 17 having a spherical lower surface is connected to the lower end of the core 16. A top surface of the enlarged diameter part is formed into a taper surface 17a inclined downward in the axial direction of a valve element 21. A seal member 20 having a spherical lower surface is fitted in a fitting hole 19a, which is formed in a seal member 19 under the enlarged diameter part 17, by the adhesive agent or the like. Lower surfaces of the seal members 19, 20 are made to abut on the inner bottom surface of a flowed pipe 1, and pushed thereto so that the seal member 19 is elastically deformed for expansion in the diameter enlarging direction and that the seal member 19 pressure-contact with the inner peripheral surface and an opening part of a through hole 3. With this structure, even in the case where elastic restoring force of the seal member 19 is lowered, the valve element 21 can be easily drawn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sluice valve device for opening and closing a pipe of a fluid pipe such as a water pipe, and more particularly to a sluice valve apparatus in which the shape of a valve body which moves forward and backward in the pipe is modified. About.

[0002]

2. Description of the Related Art As a gate valve device of this type, for example,
There is one disclosed in JP-A-8-109997. This gate valve device is provided with a valve element that can move forward and backward toward the inside of the pipe from a through hole formed in the fluid pipe, and an elastically deformable seal member on the outer periphery of the valve body is provided in the pipe. By expanding and pressing against the inner peripheral surface, the flow of the fluid is shut off.

FIG. 4 shows a main part of a valve element provided in the above conventional gate valve device. As shown, the valve body a
Is composed of a round bar-shaped core metal c having an enlarged diameter portion b at the lower end, and an elastically deformable cylindrical sealing member d such as rubber surrounding the periphery thereof. And the fluid pipe e can be made to advance and retreat from the through-hole f formed in the upper surface of the fluid pipe e into the pipeline.

When the valve body a is strongly pressed by the elevating means from the state shown in FIG. 4A, the sealing member d is elastically deformed and expanded as shown in FIG.
Is pressed against the inner peripheral surface of the liquid crystal, and the flow of fluid is interrupted.

[0005]

In the above-described valve element a of the conventional gate valve device, the upper surface of the enlarged diameter portion b of the mandrel c has a tapered surface downward toward the outer peripheral end. FIG.
When the valve body a is to be lifted from the state shown in FIG. 3B, the seal member d in contact with the upper surface of the enlarged diameter portion b tends to shift in the eccentric direction as shown by the arrow in the drawing, and the through hole f of the fluid pipe e is formed. The seal member d may be caught and difficult to come off, or the seal member d may be damaged if it is forcibly pulled up with a strong force.

In particular, when stored in the state (B) for a long period of time, it is difficult to return to the shape of (A) due to a decrease in the elastic restoring force of the seal member d, and a large pulling force is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and prevents a seal member in contact with the upper surface of an enlarged-diameter portion of a mandrel from shifting in an eccentric direction, thereby facilitating a valve body. It is an object of the present invention to provide a sluice valve device that can be pulled out.

[0008]

In order to achieve the above object, a gate valve device of the present invention is provided with a valve stem which is coaxial with a through hole formed in a fluid pipe and is advanced and retracted by reciprocating means. A valve body comprising a rod-shaped mandrel having an enlarged diameter portion at a front end and an elastically deformable seal member fitted around the mandrel so as to be relatively slidable, at a rear end face of the seal member. Is provided so as to be able to be pressed by a valve rod, and the sealing member is elastically deformed in the radially expanding direction in the fluid pipe, and is pressed against the inner peripheral surface of the fluid pipe, thereby shutting off the flow of the fluid. The rear end face of the enlarged diameter portion on the side opposite to the direction of insertion into the through hole is formed as a tapered surface inclined toward the center of the valve body and toward the tip end. According to the present invention having the above configuration, the rear end surface of the enlarged diameter portion of the mandrel is a tapered surface that is inclined toward the center and the distal direction of the valve body. When the valve element is drawn into the fluid pipe, the pulling force of the mandrel works effectively on the sealing member.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a fluid pipe such as a water pipe.
A pair of upper and lower half joints 2 are mounted on the outer peripheral surface thereof while maintaining watertightness by a packing 4 interposed in an opening of a through hole 3 formed in the upper surface of the fluid pipe 1. .

The lower end of the guide tube 5 of the gate valve device of the present invention is screwed concentrically with the through-hole 3 through the packing 6 to the connection cylinder portion 2a on the upper part of the half joint 2. A second gate valve device 7 is attached to an opening 5 a formed in the left side wall of the guide tube 5 so as to be orthogonal to the guide tube 5.

The second gate valve device 7 includes a screw rod 8,
A valve element 9 screwed into this and screwed forward, and when the drilling machine is attached / detached or a branch pipe is attached in a waterless construction method or the like, the valve element 9 is inserted into the guide pipe 5, Fluid pipe 1
Used to temporarily shut off fluid.

A valve body elevating mechanism 11 is mounted on the upper end of a cylindrical support case 10 bolted to the flange 5b at the upper end of the guide tube 5. The lifting mechanism 11
A guide cylinder 12 fitted and fixed to the upper end of the support case 10, a cylindrical valve rod 13 fitted therein so as to be able to paddle up and down and not to be relatively rotatable, and a female screw on the inner surface of the valve rod 13 The upper end of the screw rod 14 is rotatably held by the guide tube 12.

Reference numeral 15 denotes a screw cap which is screwed so as to cover the upper end of the support case 10. A square shaft portion 14a at the upper end of the screw rod 14 protrudes upward through the screw cap 15.

In the lower end portion of the valve stem 13, a round mandrel 1 is provided.
6 is screwed into the female screw hole 13a at the lower end of the valve rod 13 and projected upward to prevent it from falling off and to be detachably loosely fitted.

At the lower end (tip) of the mandrel 16, an enlarged diameter portion 17 having a spherical lower surface is continuously provided, and the upper surface (rear end surface) thereof is provided.
As shown in an enlarged view in FIG. 2, a tapered surface 17a inclined downward toward the tip end of the valve element, that is, toward the axial direction.
There is. The angle of inclination of the tapered surface 17a with respect to the horizontal plane is preferably about 5 °. Therefore, the angle formed by the lower end of the mandrel 16 and the upper surface of the enlarged diameter portion 17 is an acute angle, unlike the conventional case.

A cylindrical sealing member 19 made of an elastic rubber or the like having a diameter slightly smaller than that of the through hole 3 is provided below the pressing flange portion 18 of the valve stem 13 and on the outer peripheral surface of the mandrel 16 except for the lower surface of the enlarged diameter portion 17. Are externally fitted so as to be relatively slidable.

A seal member 20 having a spherical lower surface is fitted into a mounting hole 19a formed in the seal member 19 below the enlarged diameter portion 17 by bonding or the like. The above mandrel 16
The valve body 21 is constituted by the diametrically enlarged portion 17 and the seal members 19 and 20.

The reason why the seal member 20 is provided separately from the seal member 19 is to facilitate replacement of the seal member 20 when it is deteriorated and for easy attachment of the mandrel 16 to the valve stem 13. By removing the core member 16 by screwing it and then removing it, the seal members 19 and 20 can be easily replaced.

In order to cut off the flow of the fluid in the fluid pipe 1,
This is performed as follows.

In the state shown in FIG. 1, the square shaft portion 14a at the upper end of the screw rod 14 is rotated by a rotating tool or the like. Then, the valve rod 13 screwed to the screw rod 14 descends while being guided by the guide cylinder 12 by the screw feed action, and the valve rod 1
3 is inserted into the through-hole 3 of the fluid pipe 1.

When the screw rod 14 is further rotated after the lower surfaces of the sealing members 19 and 20 abut against the inner bottom surface of the fluid pipe 1, the sealing member 19 is
As shown in FIG. 3, the sealing member 19 in the fluid pipe 1 is elastically deformed in the radially expanding direction and expands, and is pressed against the inner peripheral surface and the opening of the through hole 3.

Thus, the flow of the fluid in the fluid pipe 1 is shut off.

When the valve rod 13 is raised by rotating the screw rod 14 in the reverse direction, the seal member 19 returns to its original shape due to the elastic restoring force, and can be pulled out of the fluid pipe 1.

At this time, the effect of the tapered surface 17a inclined in the axial direction on the upper surface of the enlarged diameter portion 17 of the mandrel 16 enhances the effect of the enlarged diameter portion 17 being caught on the seal member 19, and the sealing effect differs from the conventional one. The pulling force of the mandrel 16 effectively acts on the seal member 19 without the member 19 shifting in the eccentric direction. Therefore, even if the elastic restoring force of the seal member 19 decreases due to long-term use, the valve body 21 can be easily pulled out.

Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and even if there are changes and additions without departing from the scope of the present invention. Included in the invention.

[0027]

According to the present invention, the tensile force of the mandrel works effectively on the seal member without the seal member in contact with the enlarged diameter portion being shifted in the eccentric direction.

Therefore, even if the elastic restoring force of the seal member is reduced by long-term use, the valve body can be easily pulled out and the seal member is less likely to be damaged.

[0029]

[Brief description of the drawings]

FIG. 1 is a front view of a central longitudinal section showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of the valve element.

FIG. 3 is an enlarged vertical cross-sectional view of a valve body showing a fluid blocking state when inserted into a fluid pipe.

FIG. 4 is a longitudinal sectional view showing a state before and after a fluid is shut off in a valve body of a conventional gate valve device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fluid pipe 2 half joint 3 through hole 4, 6 packing 5 guide pipe 5 a opening 7 second gate valve device 8 screw rod 9 valve body 10 support case 11 elevating mechanism (reciprocating means) 12 guide cylinder 13 valve rod 13a Female screw hole 14 Screw rod 14a Square shaft part 15 Screw cap 16 Mandrel 16a Male screw part 17 Large diameter part 17a Tapered surface 18 Pressing flange part 19, 20 Seal member 19a Mounting hole 21 Valve body

Claims (1)

[Claims] 1. A rod-shaped mandrel, which is coaxial with a through hole formed in a fluid pipe and has an enlarged-diameter portion at a tip end of a valve stem which is moved forward and backward by reciprocating means, and A valve body comprising an elastically deformable seal member fitted externally so as to be relatively slidable is provided so that the rear end face of the seal member can be pressed by a valve rod, and the seal member is disposed in the fluid pipe in a radially expanding direction. In a gate valve device that is elastically deformed and pressed against the inner peripheral surface of the fluid pipe to block the flow of the fluid, the rear end face of the enlarged diameter portion opposite to the direction of insertion into the through-hole, A gate valve device characterized in that the valve body has a tapered surface inclined toward a center and a tip direction of the valve body.