JP3140555U - Concrete pipe connection structure and seal ring of connection part - Google Patents

Abstract

The present invention relates to a connection structure for a concrete tube, and there is no risk of peeling, twisting or breaking of the seal ring at the time of connection, and both the intrusion of water from the outside into the pipe and the leakage of water from the inside of the pipe to the outside. Technical means that can be reliably prevented are provided.
SOLUTION: A negative pressure is applied to a cavity 3 provided in a circumferential direction of a rubber-like seal ring 1 integrally provided with seal lips provided obliquely so as to face both outer sides in the tube axis direction on an outer peripheral portion. Then, after inserting the insertion end 6 into the socket 12 of the adjacent tubular body in a state where the outer diameter is reduced by pressing the seal ring to the atmospheric pressure, the cavity 3 is opened to the atmospheric pressure or pressurized to be connected. The seal ring 1 that has been pressed at the time of work is restored by the elasticity of rubber or the elasticity of rubber and the pressure in the cavity 3, and the tip side of the seal lip 2 standing on the outer periphery of the seal ring is moved into the socket 12. A water sealing effect is exerted by pressing against the peripheral surface.
[Selection] Figure 5

Description

  The present invention relates to a water ring sealing ring provided at a connecting portion of a concrete pipe such as a box culvert or a fume pipe, and a concrete pipe connecting structure using such a seal ring.

  Concrete pipes (hereinafter simply referred to as “tubes”) such as box culverts and fume pipes are molded to a predetermined length in a concrete molding factory. These pipes form a pipe line by connecting opposite pipe ends of adjacent pipes.

  As shown in FIG. 9, the connecting portion has a structure in which a plug end 6 having a small outer diameter is formed at one end of the tube and a socket (plug end having a large inner diameter is formed at the other end. The insertion end 6 is inserted into the adjacent socket 12 of the tubular body in a state in which the sealing ring 1 for water sealing is fitted on the outer periphery of the insertion end 6. A structure that is inserted in the axial direction is known.

  Normally, the seal ring 1 is integrally provided with a plurality of seal lips 2 extending obliquely in the axial direction so as to form a narrow truncated cone-shaped tongue piece on the outer periphery. The seal lip is inclined in the direction inclined toward the tube body 5 on the insertion end 6 side, that is, the direction in which the lip falls due to frictional force acting from the inner peripheral surface of the socket when the insertion end 6 is inserted into the socket 12. It is provided with an inclination.

  If a lip inclined in the opposite direction to the above is provided on the outer periphery of the seal ring, when the insertion end portion 6 is inserted into the socket 12, the lip inclined in the opposite direction acts on the reaction force acting from the socket 12. The insertion is prevented from standing up and the insertion end 6 cannot be inserted into the socket 12.

  The seal ring 1 needs to be flexible to reduce the diameter when the insertion end 6 is inserted into the socket 12. On the other hand, after the pipe body is connected, it is necessary to have a rigidity capable of reliably sealing with water even when a pressure difference occurs inside and outside the pipe. Generally, in the seal ring 1, a circumferential cavity 3 is formed at the center of the cross section so that the outer diameter is crushed and easily reduced when inserted into the socket 12.

  When the insertion end 6 is inserted into the socket 12, the seal ring 1 is easily turned up as shown in FIG. 8 due to axial frictional force acting from the socket 12. Further, if the axial centers of the insertion end 6 and the socket 12 are shifted at the time of insertion, this rolling up may occur unevenly and the seal ring may be twisted or broken.

In order not to cause such a problem, the seal ring 1 is bonded to the outer periphery of the insertion end portion 6 with an adhesive, and generally, a circumferential groove is provided on the outer periphery of the insertion end portion 6. Thus, the inner periphery side of the seal ring 1 is bonded in a state of being fitted in the circumferential groove. As a structure for preventing the seal ring 1 from rolling up and breaking when the pipe is connected, Patent Document 1 discloses that the inner diameter side of the seal ring 1 is embedded in the outer periphery of the insertion end portion 6 when molding the pipe body (molding is performed). ) A structure has been proposed.
JP 2005-54883 A

  In the connection of the pipes as described above, the pipe connection work is facilitated, that is, the insertion end is easily inserted into the socket of the adjacent pipe, and a reliable water seal of the connection part is realized. This is a technical problem that is mutually contradictory. In other words, reducing the crushing allowance of the seal ring when it is inserted or making the rubber of the seal ring flexible makes the tube connection work easier, but the pressing force of the seal lip against the inner periphery of the socket Since the seal lip is easily deformed by a pressure difference between the inside and outside, the water sealing performance is lowered. On the other hand, if the crushing margin of the seal ring is increased or the rubber is made of high hardness, the water sealing performance is improved, but the frictional force acting on the seal lip from the socket when inserting the insertion end is increased. A large force is required for insertion, and peeling or tearing of the seal ring is likely to occur.

  In the construction of culverts or pipes, it is necessary to ensure that the water sealing action at the pipe connection is performed under specified conditions. However, if the hardness of the rubber of the seal ring is increased or the crushing allowance is increased for this requirement, the workability at the time of pipe connection is lowered, and the risk of construction failure due to twisting or breaking of the seal ring increases. There was a problem.

  Further, in the conventional seal ring, in order to allow the insertion end 6 to be inserted inside the socket 12, only the inclination direction of the seal lip 2 can be provided in such a direction that the seal lip is tilted by the insertion force. As shown in FIG. 8, the water A trying to enter the pipe from the outside can be surely blocked, but there is a problem that the water seal against the water B leaking from the inside to the outside is incomplete. .

  The present invention has been made to solve these problems. In connecting the pipes having the above-described structure, the pipes can be easily connected without reducing the water sealing performance of the seal ring at the connecting part. It is an object of the present invention to provide a technical means that can be used and that does not cause peeling, twisting, breakage or the like of the seal ring during connection. Furthermore, the present invention provides a technical means that facilitates connection work of the pipe bodies and can reliably prevent both the ingress of water from the outside into the pipe and the leakage of water from the inside of the pipe to the outside. It is an issue.

  The seal ring of the tube connecting portion according to the present invention is the difference between the inner periphery of the socket 12 provided at one tube end of the tube 5 that connects the tube ends and the other tube inserted in the socket. It is a rubber-like seal ring interposed between the outer periphery of the insertion end portion 6 and water-sealing the connection portion between the tube ends. The seal ring of the present invention includes a circumferential cavity 3 at the center of the cross section, and a suction pipe 4 that communicates with the cavity 3 and extends toward the radially inner side.

  The seal ring of the tube connecting portion according to the invention of claim 1 of the present application is a seal ring having the above-described structure, and the distal end edge is pressed against the inner peripheral surface of the socket 12 on the outer peripheral portion of the seal ring. The seal lip 2 is erected so as to form a narrow frustoconical membrane, and the seal lip is provided on one side and the other side in the tube axis direction of the outer periphery of the seal ring on each side. The tip edges of the objects 2a and 2b are provided so as to be inclined so as to be located further outside in the tube axis direction on the side.

  The seal ring 1 of the present invention enables negative pressure to act on the cavity 3 provided in the circumferential direction, and enables the seal ring to be compressed (crushed flat) at atmospheric pressure. . The seal ring 1 of the present invention is capable of inserting the insertion end portion 6 to which the seal ring is attached into the adjacent socket 12 of the tubular body in a state where the outer diameter is reduced by the compression. After being inserted, the cavity 3 is returned to atmospheric pressure or pressurized, and the seal ring 1 that has been compressed at the time of connection work is restored by the elasticity of rubber or the elasticity of rubber and the pressure in the cavity 3, and the seal ring The seal lip 2 erected on the outer periphery or the outer peripheral portion of the socket 12 is pressed against the inner peripheral surface of the socket 12 to exert a water sealing effect.

  The seal ring 1 of the present invention includes a suction pipe 4 whose proximal end communicates with the cavity 3 and extends in the radial direction on the inner diameter side of the seal ring in order to apply a negative pressure to the cavity 3. When the seal ring 1 is fitted to the insertion end 6 of the tubular body, the suction pipe 4 is inserted into a pipe insertion hole 7 provided so as to penetrate the tube wall of the insertion end 6. The suction pipe 4 has a length that protrudes toward the inner diameter side of the pipe insertion hole 7.

  The pipe connection structure according to claim 2 of this application is a pipe connection structure using a seal ring according to the invention of the present application. That is, the insertion end 6 provided at one pipe end of the two pipes is inserted into the socket 12 provided at the other pipe end to connect the two pipes, and the insertion end 6 In the tube connecting structure for sealing the connecting portion by interposing a rubber-like seal ring 1 having a cross-sectional shape with a circumferential cavity 3 between the outer periphery of the socket 12 and the inner periphery of the socket 12, A pipe insertion hole 7 that penetrates the tube wall of the insertion end 6 in the radial direction, and a suction pipe 4 that communicates with the cavity 3 and extends toward the radially inner diameter side of the seal ring 1 and is inserted into the pipe insertion hole 7. And the tube 3 is connected to the cavity 3 by the negative pressure applied from the suction pipe 4 to reduce the outer diameter of the seal ring.

  The seal ring 1 in the connection structure is erected obliquely on one side and the other side in the tube axis direction of the outer peripheral portion thereof so as to be integrated with the seal ring and facing both sides in the tube axis direction. Further, a sealing lip made of a narrow truncated conical membrane is provided, the tip edge of which is pressed against the inner peripheral surface of the socket.

  When the tube body is inserted, a vacuum pump is connected to the suction pipe 4 to continuously suck air in the cavity 3 and the insertion is completed. Then, the vacuum pump is removed and the negative pressure in the cavity 3 is released. Alternatively, before attaching the seal ring 1 to the plug-in end 6, a negative pressure is applied to the cavity 3 with a vacuum pump, and in this state, the tip of the suction pipe 4 is heat-sealed or fitted with a stopper and sealed. In this state, the seal ring 1 is attached to the insertion end 6 to perform connection work, and then the tip of the suction pipe 4 is cut off to release the negative pressure in the cavity 3.

  If necessary, it is also possible to inflate the cavity 3 positively by injecting pressurized air or a foaming agent into the cavity 3 from the suction pipe 4. When injecting the foaming agent into the cavity 3, two suction pipes 4 are provided at intervals in the circumferential direction of the seal ring 1, and the foaming agent is injected from one of them, or a needle is inserted into the suction pipe 4. A foaming agent is injected into the cavity 3 from the needle.

  When the pipes are connected to each other, that is, when the insertion end portion 6 provided on one pipe is inserted into the socket 12 of the adjacent pipe, the seal ring 1 is compressed by the atmospheric pressure to reduce the diameter. Work is extremely easy. Further, since the frictional force acting from the socket 12 on the outer periphery or seal lip of the seal ring when inserted can be greatly reduced, it is possible to completely prevent the seal ring from being peeled off, twisted or broken.

  Further, since a large frictional force does not act from the socket 12 during insertion, the outer edge of the outer periphery of the seal ring is directed toward the distal end side of the insertion end, that is, tilted in a direction to stand up by the frictional force acting from the socket during insertion. Even if the sealing lip is provided, it is possible to prevent troubles in inserting the insertion end portion 6 into the socket 12. Accordingly, by providing both the seal lip 2a inclined in such a direction and the seal lip 2b inclined in the same direction as in the conventional case, the connection inside and outside of the pipe is released in the connection completed state in which the negative pressure in the cavity 3 is released. It can be set as the structure which can exhibit the reliable water seal effect | action from both directions.

  Hereinafter, the present invention will be further described with reference to FIGS. 1 to 7 showing an embodiment of the present invention. As shown in FIGS. 2 and 7, the seal ring 1 of the present invention is provided with seal lips 2 a and 2 b inclined on both sides in the tube axis direction. It is preferable to provide two or three seal lips 2a and 2b inclined on each side. The seal lips 2a and 2b arranged on both sides of the seal ring 1 in the tube axis direction are inclined so that the tip faces further outward in the tube axis direction on each side.

  In a substantially central portion of the seal ring 1, a circumferential cavity 3 having a cross-sectional shape elongated in the tube axis direction is provided. A rubber suction pipe 4 extending in the radial direction is provided on one inner circumferential wall of the seal ring 1 or at two locations spaced in the circumferential direction by adhesion or integral molding. The proximal end of the suction pipe 4 communicates with the cavity 3 and the distal end is open.

  A pipe insertion hole 7 indicated by a broken line in FIG. 3 is provided in the insertion end portion 6 of the tubular body 5 through the peripheral wall in the radial direction. As shown in FIG. 4, a counterbore hole (a hole having a large diameter and a short axial length) 9 is provided at the inner peripheral side end of the pipe insertion hole 7. A circumferential groove 8 for fitting a portion on the inner diameter side of the seal ring 1 is provided on the outer periphery of the insertion end portion 6. The seal ring 1 is fitted to the insertion end 6 in a state where the inner peripheral surface thereof and the bottom surface of the circumferential groove 8 are adhered with an adhesive and the suction pipe 4 is inserted through the pipe insertion hole 7. The In this mounted state, the suction pipe 4 passes through the pipe insertion hole 7 and its tip protrudes at least in the counterbore 9 portion.

  When the seal ring 1 is placed in the vacuum chamber and the tip of the suction pipe 4 is sealed with a stopper 13 or a heat seal, and taken out from the vacuum chamber, the cavity 3 of the seal ring is compressed by atmospheric pressure (flattened flat) Thus, the outer diameter of the seal ring 1 is reduced (see FIG. 2B). The reduced diameter seal ring 1 is attached to the insertion end 6 of the tube 5 (FIG. 4), the insertion end 6 is inserted into the socket 12 of the adjacent tube (FIG. 5), and after the insertion is completed, When the stopper 13 is removed or the tip of the suction pipe 4 is removed, the atmosphere is introduced into the cavity 3, the cavity 3 expands due to the elasticity of rubber, and the tips of the seal lips 2a and 2b are elastically pressed against the inner surface of the socket 12 ( FIG. 6).

  Alternatively, the insertion end 6 is connected to the tip of the suction pipe 4 of the seal ring 1 attached to the insertion end 6 of the tube body by connecting a vacuum pump to suck the air in the cavity 3 and press the cavity 3 at atmospheric pressure. Is inserted into the socket 12 of the adjacent tube body, and when the vacuum pump is removed after the insertion is completed, the atmosphere is introduced into the cavity 3, the cavity 3 expands due to the elasticity of rubber, and the ends of the seal lips 2a, 2b are the sockets The inner surface of 12 is repressed (FIG. 6).

  When it is desired to increase the elastic pressure of the seal lips 2a, 2b to the inner surface of the socket 12 after the tube connection is completed, the suction pipe 4 and the pipe insertion hole 7 are provided with two circumferentially spaced apart. After introducing the atmosphere into the cavity 3, a foam injection nozzle is inserted into the counterbore 9 of one of the pipe insertion holes, and the foaming agent is injected into the cavity 3 through the suction pipe 4 inserted therethrough. As the foaming agent, a foaming agent for forming a rubbery film is used, and foaming is performed in the cavity 3, and the suction pipe 4 is sealed with the foamed film.

  Even if there is only one suction pipe 4, a needle having a diameter smaller than the inner diameter of the suction pipe 4 is attached to the tip of the foam injection pipe provided with the needle, and the needle is attached to the suction pipe 4 so that the tip reaches the cavity 3. The foaming agent can be injected into the cavity 3 in this state. At the time of injection, air in the cavity 3 and excess foaming agent flow out through a gap between the needle and the suction pipe.

  As shown in FIG. 7, the cross-sectional shape of the cavity 3 can be a cross-sectional shape such as a drum shape in which both ends in the tube axis direction expand in the radial direction. With such a shape, when both ends of the axial direction of the seal ring 1 are compressed more than the intermediate portion when the seal 3 is compressed with the negative pressure of the cavity 3, the axial direction of the outer periphery of the seal ring is increased. The seal lips 2a and 2b provided on both sides fall with the compression of the seal ring, and the tip edges of the seal lips 2a and 2b can be greatly reduced in diameter during the compression.

  As shown in FIG. 6, the seal ring 1 thus mounted has the pressure A at which the seal lips 2 a and 2 b on both sides are directed from the outside into the pipe and the pressure B from the inside to the outside to the pressure. Since the sealing is performed by raising the sealing lips 2a and 2b, it is possible to reliably perform water sealing in both the inside and outside of the pipe.

Front view showing an example of the seal ring of this device 1 is an enlarged cross-sectional view of the seal ring of FIG. 1 in a normal state (a) and an atmospheric pressure compression state (b). FIG. 1 is a front view of an insertion end portion of a pipe body to which the seal ring of FIG. 1 is attached. Enlarged cross-sectional view of the seal ring attached to the insertion end under atmospheric pressure Enlarged sectional view showing the state of the connecting part during insertion work Enlarged sectional view showing the state of the connection after connection is completed A view similar to FIG. 2 of a seal ring with a drum-shaped cavity Enlarged sectional view showing an example of conventional seal ring structure Explanatory drawing of the water sealing action of a conventional seal ring

Explanation of symbols

1 Seal ring
2 (a, b) Seal lip 3 Cavity 4 Suction pipe 5 Tubing body 6 Insertion end 7 Pipe insertion hole
12 socket

Claims (2)

It is interposed between the inner periphery of the socket provided at one pipe end of the concrete pipes connecting the pipe ends to each other and the outer periphery of the insertion end of the other pipe inserted into the socket. A rubber ring that seals the joints between the pipe ends, a seal ring having a cavity in the center of the cross section, and a narrow truncated cone whose tip edge is elastically pressed against the inner peripheral surface of the socket In the seal ring provided on the outer periphery with a seal lip erected so as to form a film,
A suction pipe that communicates with the cavity and extends toward the radially inner side, and the seal lip that is inclined so as to face both outer sides in the tube axis direction on one side and the other side in the tube axis direction; Seal ring for connecting concrete pipes. Insert the insertion end provided at one pipe end of the two concrete pipes into the socket provided at the other pipe end to connect the two pipes together, and the outer periphery of the insertion end and the socket In the connection structure of the concrete tube that water seals the connection part by interposing a rubber seal ring having a cross-sectional shape with a circumferential cavity between the inner periphery of
One end and the other side in the tube axis direction of the outer peripheral portion of the seal ring are obliquely erected so as to be integral with the seal ring and face both outer sides in the tube axis direction, and the leading edge is inside the socket. A sealing lip made of a narrow truncated cone film that is repressed on the peripheral surface;
A pipe insertion hole that penetrates the tube wall of the insertion end portion in a radial direction;
A suction pipe that communicates with the cavity and extends to the radially inner side of the seal ring and is inserted into the pipe insertion hole;
A connecting structure for a concrete pipe, wherein the outer circumference of the seal ring is reduced in diameter by compressing the cavity by a negative pressure applied from the suction pipe when the pipe is connected.

Images