JP4213055B2 - Pipe connection seal structure - Google Patents

Description

  The present invention relates to a seal structure of a pipe connection part.

  Conventionally, for example, with respect to a cylindrical body in a pipe joint, the space between the pipe extrapolated from the axial direction in an externally fitted state and the cylindrical body is sealed with an elastic seal member attached to the outer peripheral surface of the cylindrical body. The seal structure of the pipe connection part made is widely adopted.

In recent years, for example, resin pipes made of a hard resin material have been used as pipes for water supply and hot water supply.
In this case, it is possible to cut and connect long resin pipes according to the situation at the construction site, to configure the pipe with an appropriate length according to the situation at the construction site, and to make a pipe connection in a good state. it can.

  However, in this case, when cutting the pipe in detail, it may be cut obliquely. In this case, if the pipe is extrapolated in the axial direction from the side cut obliquely, There is a problem that the mounted seal member protrudes from the holding groove.

7 and 8 explain this in detail.
In FIG. 7, reference numeral 200 denotes a tube body, and 202 denotes an annular holding groove formed on the outer peripheral surface and having an open outer peripheral surface, and an annular seal member (here, an O-ring) 204 having elasticity is attached thereto. Has been.
206 is a resin pipe, and 208 is a front end surface cut obliquely.

  As shown in FIG. 8, when the resin pipe 206 is externally inserted from the front end surface 208 side in the axial direction with respect to the cylindrical body 200, the seal member 204 is obliquely cut from the lower end in the figure by the front end surface 208. The upper part in the figure protrudes from the holding groove 202 by being drawn up upward.

More specifically, when the resin pipe 206 is extrapolated to the cylindrical body 200 in the axial direction and the lower end portion in the drawing is fitted to the lower portion of the annular seal member 204, the lower portion of the seal member 204 is forcibly elastically deformed in the reduced diameter direction. It is done.
On the other hand, since the upper part of the seal member 204 is not yet restrained by the resin pipe 206, the seal member 204 that is forcibly elastically deformed in the reduced diameter direction at the lower part is drawn up as if from the lower side to the upper side. Then, the upper part is lifted from the holding groove 202 (I).

  In this state, when the resin pipe 206 is further pushed in the right direction in the figure, the upper part of the seal member 204 floating upward is brought into contact with the front end surface of the resin pipe 206 and pushed in the right direction in the figure, and from the holding groove 202. It protrudes to the right in the figure (II).

In such a state, the seal member 204 did not seal well between the cylindrical body 200 and the resin pipe 206 in the pipe connection state, the sealing performance was impaired, and the seal member 204 was forced to protrude from the holding groove 202. There arises a problem that the seal member 204 is damaged.
Although the resin pipe has been described above as an example, such a problem may occur when pipes of other materials are used and the pipes are cut and connected.

The present invention has been made to solve such problems.
In addition, there exist some which were disclosed by following patent document 1, patent document 2, patent document 3, patent document 4 as a prior art relevant to this invention.
Although all of those disclosed in Patent Documents 1 to 4 are intended to prevent the seal member from protruding when pipes are connected, the solution is different from that of the present invention.

JP 2002-323179 A JP 2002-295552 A JP 2003-42370 A JP 2001-124258 A

  The present invention has such a situation as a background, and when a pipe is cut and connected at the site or the like, and even when the pipe is cut obliquely at that time, the sealing member is used for connecting the pipe. Is intended to provide a seal structure for a pipe connection portion that does not protrude from the holding groove, and therefore does not damage the seal member or cause a seal failure based on the protrusion. .

  Thus, according to the first aspect of the present invention, the space between the pipe extrapolated from the axial direction in an externally fitted state with respect to the cylinder and the cylinder is sealed by an elastic sealing member attached to the cylinder. In the sealing structure of the pipe connection portion thus formed, a cylindrical holding groove is formed along the outer peripheral wall portion on the radial inner side of the outer peripheral wall portion provided in the circumferential direction along the outer peripheral surface of the cylindrical body. In addition, an opening having an axial width narrower than the holding groove is provided in the outer peripheral wall portion over the entire circumference, while the shape of the seal member projects radially outward from the outer peripheral surface of the cylindrical body. A shape having an annular seal body that elastically contacts the inner peripheral surface of the pipe, and a flat portion that extends in a substantially uniform thickness in the axial direction from the radially inner base of the seal body. The flat portion is constrained in the holding groove, and the seal body portion is an opening provided in the outer peripheral wall portion. Characterized in that without such to protrude radially outward.

  According to a second aspect of the present invention, in the first aspect, the pipe is a resin pipe.

  According to a third aspect of the present invention, in any one of the first and second aspects, the flat portion is formed with a thickness substantially the same as a depth of the holding groove.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the axial width of the opening is larger than the axial thickness of the seal main body, and the seal main body and the opening A gap that allows tilting deformation of the seal body portion is formed between the axial end edge of the portion and a position opposite to the extrapolation side of the pipe with respect to the seal body portion. And

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the outer peripheral wall portion is formed by fitting a ring separate from the main body of the cylindrical body.

Effects and effects of the invention

  As described above, the present invention forms a cylindrical holding groove on the radially inner side of the outer peripheral wall provided in the circumferential direction along the outer peripheral surface of the cylindrical body, and has a narrow opening on the outer peripheral wall. On the other hand, the seal member has a shape having a seal body portion and a flat portion, the flat portion is constrained in the holding groove by the barrier action of the outer peripheral wall portion, and the seal body portion is radially formed from the opening portion. It is designed to protrude outward.

  According to the present invention, when the pipe is externally fitted and connected to the cylindrical body from the axial direction, the flat portion of the seal member is retained in the holding groove even when the front end surface of the pipe is cut obliquely. Since it is in the state restrained inside, it can prevent satisfactorily that a sealing member protrudes from a holding groove by the front end surface.

Therefore, according to the present invention, it is possible to satisfactorily seal the connecting portion between the cylindrical body and the pipe with the sealing member without causing problems such as deterioration of the sealing property due to the protrusion of the sealing member, or damage to the sealing member and deterioration of the sealing property due thereto. Can do.
Here, the flat portion is preferably formed in a cylindrical shape continuous in the circumferential direction.

As is apparent from the above description, the present invention is particularly suitable when applied to a case where the pipe is a resin pipe (claim 2).
The flat portion can be formed with a thickness substantially the same as the depth of the holding groove.
By doing so, the flat portion can be restrained more favorably by the holding groove.

  According to a fourth aspect of the present invention, a gap is provided between the axial end edge of the opening and the seal main body. According to the fourth aspect, when the pipe is extrapolated to the cylinder, the seal is caused by the presence of the gap. The tilting deformation of the main body can be allowed, and this can more effectively prevent the seal main body from protruding from the holding groove.

  According to a fifth aspect of the present invention, the outer peripheral wall portion is formed by fitting a ring separate from the main body of the cylindrical body. In this way, the outer peripheral wall portion can be easily configured, and thus the cylinder A cylindrical holding groove at a position drawn radially inward from the outer peripheral surface of the body can be easily configured.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, 10 is a pipe joint, 12 is a joint body and has a flange-shaped large-diameter tool hanging portion 14, and a male thread 16 is formed on the outer peripheral surface on the right side of the tool hanging portion 14 in the drawing. Yes.
In addition, an inner cylinder portion (tubular body) 18 is integrally formed on the left side in the drawing opposite to the male screw 16.
The resin pipe 20 is extrapolated from the axial direction in an externally fitted state with respect to the inner cylindrical portion 18, and is connected to the inner cylindrical portion 18.

Reference numeral 22 denotes an outer cylinder member, which is screwed to a male screw 26 of the joint body 12 at a female screw 24 on the right end and inner peripheral side in the drawing.
Reference numeral 27 denotes a lock member having an elastic arm 28 and a claw 30 as shown in FIG. 2. The claw 30 is bitten into the outer peripheral surface of the resin pipe 20, so that the resin pipe 20 is kept in a state of being removed. Lock it.

The lock member 27 is biased leftward in FIG.
The claw 30 of the lock member 27 bites into the outer peripheral surface of the resin pipe 20 by the action of the cam surface 34 formed on the outer cylinder member 22 by the urging force and the force in the pulling direction applied to the resin pipe 20 to prevent pulling.

  Reference numeral 36 denotes a release member for releasing the lock by the lock member 27. When the lock member 27 is pushed in the right direction in FIG. 1, the claw 30 is pushed and expanded radially outward by the release member 36. The biting into the resin pipe 20 is released. That is, the lock by the lock member 27 is released.

  As shown in FIG. 4, two cylindrical holding grooves 38 that are continuous in the circumferential direction on the inner side in the radial direction from the outer peripheral surface of the inner cylindrical portion 18 are provided adjacent to each other in the axial direction. An annular seal member 40 having elasticity is held there.

  In FIG. 4, 18B-1, 18B-2, and 18B-3 are steel rings that are separate from the main body 18A (see FIG. 3) and constitute the inner cylindrical portion 18 together with the main body 18A. Is constituted by these rings 18B-1, 18B-2, 18B-3 and a main body 18A.

These rings 18B-1, 18B-2 and 18B-3 constitute a cylindrical outer peripheral wall 48 on the outer peripheral side of the holding groove 38.
In addition, an opening 50 having a narrower axial width than the holding groove 38 is provided in the outer peripheral wall 48 over the entire circumference.

  Here, the axial width of the opening 50 is larger than the axial thickness of a seal main body 52 to be described later in the seal member 40, and the axial direction on the right side of the seal main body 52 and the opening 50 in the drawing. A gap S is formed between the end edge, that is, on the opposite side of the seal main body 52 from the extrapolation side of the resin pipe 20.

  The seal main body 52 protrudes radially outward from the outer peripheral surface of the inner cylindrical portion 18 before the resin pipe 20 is connected, and the seal main body 52 elastically protrudes from the inner peripheral surface of the resin pipe 20. By closely contacting, the space between the resin pipe 20 and the inner cylinder portion 18 is sealed in a watertight manner.

In these seal members 40, the flat portion 54 extends in the axial direction from the base portion on the base side of the seal main body 52 with a substantially uniform thickness, and the extended flat portion 54 is restrained by the holding groove 38. Is held in.
Specifically, the outer peripheral wall portion 48 constituted by the rings 18B-1, 18B-2, and 18B-3 is restrained in a direction in which the flat portion 54 is pressed radially inward, and the entire seal member 40 is It is restrained and held in the holding groove 38 by the barrier action.

A seal main body 52 in the seal member 40 is protruded radially outward from the outer peripheral surface of the inner cylinder 18 through an opening 50 formed in the outer peripheral wall 48.
The flat portion 54 of the seal member 40 has a cylindrical shape that is continuous in the circumferential direction.

In the present embodiment, the rings 18B-1 and 18B-2 are loosely fitted to the main body 18A in the inner cylindrical portion 18.
On the other hand, the last ring 18B-3 is press-fitted into the main body 18A and is firmly fixed to the main body 18A.

Here, the rightmost ring 18B-1 in the drawing is axially pushed and positioned there until it abuts against a stepped portion 42 formed on the main body 18A.
On the other hand, the ring 18B-2 in the middle in the axial direction is provided with an annular projecting portion 44 that faces downward (inward in the radial direction) in the figure, and this projecting portion 44 projects outward in the radial direction provided on the main body 18A. It is pushed in the axial direction to the position where it abuts on the portion 46, specifically, in the right direction in FIG.

FIG. 5 shows the procedure for assembling the rings 18B-1, 18B-2, 18B-3 and the two seal members 40. FIG.
As shown in the figure, in this embodiment, first, the ring 18B-1 is pushed into the main body 18A and externally fitted, and then the right seal member 40 is attached to the main body 18A in an externally fitted state.

  Subsequently, the intermediate ring 18B-2 is pushed in as shown in FIG. At this time, the radially inward projecting portion 44 of the ring 18B-2 is pushed into a position where the projecting portion 46 comes into contact with the radially outward projecting portion 46 of the main body 18A.

Next, after the second seal member 40 is mounted on the main body 18A in an externally fitted state, the last ring 18B-3 is press-fitted into the outer peripheral surface of the main body 18A and fixed.
Here, the two sealing members 40 are held in the holding groove 38 in a restrained state.

In the present embodiment, the resin pipe 20 is extrapolated to the right in the figure in an externally fitted state with respect to the inner cylindrical portion 18 in the pipe joint 10, so that the resin pipe 20 is connected to the pipe joint 10 based on the locking action by the lock member 27. Is connected to the unplugged state.
At this time, even if the front end surface 56 of the resin pipe 20 is an oblique cut surface as shown in FIG. 6, the sealing member 40 is lifted from the holding groove 38 by the restraining action of the flat portion 54 by the holding groove 38. Is prevented.

  In addition, in this embodiment, a gap S is formed on the front side (right side in the figure) of the seal main body 52 in the seal member 40, and as shown in the enlarged view of the main part of FIG. Since the seal body 40 can be tilted and deformed in the gap S when the resin pipe 20 is pushed, the seal member 40 can be well prevented from protruding from the holding groove 38 when the resin pipe 20 is pushed.

  Therefore, according to the present embodiment, the problem of deterioration of the sealing performance due to the protrusion or damage of the seal member 40 does not occur, and the seal member 40 can satisfactorily provide a gap between the inner cylinder portion 18 and the resin pipe 20 connected to each other. Can be sealed.

  In the present embodiment, the outer peripheral wall portion 48 is configured by fitting rings 18B-1, 18B-2, and 18B-3, which are separate from the main body 18A of the inner cylindrical portion 18, and therefore the outer peripheral wall portion 48 is formed. Thus, the cylindrical holding groove 38 at a position drawn inward in the radial direction from the outer peripheral surface of the inner cylindrical portion 18 can be easily configured.

  Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be configured in various modifications without departing from the spirit of the present invention.

It is a figure which shows the seal structure of the pipe connection part of one Embodiment of this invention in a pipe connection state. It is sectional drawing which decomposes | disassembles and shows the piping joint of FIG. It is a disassembled perspective view of the coupling main body of FIG. It is a figure which expands and shows the principal part of the seal structure of the embodiment. It is explanatory drawing of the assembly | attachment procedure in the seal structure of the embodiment. It is operation | movement explanatory drawing of the embodiment. It is a figure which shows an example of the seal structure of the conventional piping connection part. It is explanatory drawing of the malfunction of the seal structure of FIG.

Explanation of symbols

10 Piping joint 18 Inner cylinder (cylinder)
18B-1, 18B-2, 18B-3 Ring 20 Resin piping 38 Holding groove 40 Seal member 48 Outer peripheral wall portion 50 Opening portion 52 Seal body portion 54 Flat portion

Claims (5)

Sealing structure of a pipe connection part that seals between the pipe extrapolated from the axial direction in an externally fitted state to the cylinder and the cylinder with an elastic sealing member attached to the cylinder In
A cylindrical holding groove is formed along the outer peripheral wall portion in the radial direction of the outer peripheral wall portion provided in the circumferential direction along the outer peripheral surface of the cylindrical body. An opening having a narrow width in the axial direction is provided over the entire circumference, while the shape of the seal member is an annular ring that protrudes radially outward from the outer peripheral surface of the cylindrical body and elastically contacts the inner peripheral surface of the pipe. A shape having a seal main body and a flat portion extending with a substantially uniform thickness in the axial direction from a base portion on the radially inner side of the seal main body, and constraining the flat portion in the holding groove And a seal structure for a pipe connection portion, wherein the seal main body portion protrudes radially outward from an opening provided in the outer peripheral wall portion.   2. The pipe connection seal structure according to claim 1, wherein the pipe is a resin pipe.   3. The pipe connection sealing structure according to claim 1, wherein the flat portion is formed with a thickness substantially the same as a depth of the holding groove.   In any one of Claims 1-3, The width | variety of the axial direction of the said opening part is made larger than the axial thickness of the said seal | sticker main-body part, The axial direction edge of this seal | sticker main-body part and this opening part, And a gap that allows the seal body to be tilted and deformed at a position opposite to the extrapolation side of the pipe with respect to the seal body. Construction.   5. The pipe connection portion sealing structure according to claim 1, wherein the outer peripheral wall portion is formed by fitting a ring separate from the main body of the cylindrical body.

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