JP5455383B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a pipe joint in which an insertion opening formed at the end of the other pipe is inserted into a receiving opening formed at the end of one pipe connected to each other.

  Conventionally, as this type of pipe joint, for example, as shown in FIG. 6, a receiving port 12 is formed at the end of one tube 11, and a back end surface 13 is formed at the back side of the receiving port 12. Has been. A lock ring receiving groove 14 having a rectangular cross section is formed on the opening side of the receiving port 12 with respect to the rear end face 13. The lock ring receiving groove 14 is annular and has a crossing rate of 10% in the circumferential direction. A rectangular lock ring 15 is accommodated.

  A tapered surface 16 that extends toward the opening side is formed further on the opening side than the lock ring housing groove 14. A radially outward flange 18 is formed on the outer periphery of the end of the receiving port 12. A plurality of round holes 19 are formed in the flange 18 in a penetrating state.

  An insertion port 22 is formed at the end of the other tube 21, and an insertion projection 23 is formed on the outer periphery of the end of the insertion port 22. The insertion opening 22 is inserted into the receiving opening 12 until the insertion protrusion 23 is located between the lock ring 15 and the back end face 13. Moreover, the outer diameter of the insertion protrusion 23 is formed larger than the inner diameter of the lock ring 15, and the inner diameter of the lock ring 15 and the outer diameter of the insertion opening 22 are formed in the same manner.

  On the outer periphery of the insertion port 22 on the opening side of the receiving port 2 with respect to the position of the lock ring 15, a circumferentially divided backup ring 24 and an annular rubber seal material 25 are arranged. An annular push ring 26 having an outer diameter similar to that of the receiving port 12 is provided on the outer periphery of a portion of the other tube 21 that does not enter the receiving port 12.

  The pusher ring 26 is formed with a plurality of round holes 27 corresponding to the plurality of round holes 19 formed in the flange 18 of the receiving port 12. A T-shaped bolt 28 is passed through each of the round hole 27 and the round hole 19 as shown in the figure, and a nut 29 is screwed onto the T-shaped bolt 28.

  By the tightening force between the T-shaped bolt 28 and the nut 29, the pusher ring 26 is formed in the receiving port 12 by pressing the sealing material 25 and the backup ring 24 arranged on the outer periphery of the insertion port 22 in the tube axis direction. The sealing material 25 is pressed against the tapered surface 16 that is formed. Thereby, the sealing function in this pipe joint is exhibited.

  The pipe joint having the above-described configuration is described in, for example, Patent Document 1 below.

JP 2003-214573 A

  However, in the above conventional type, in order to maintain high water tightness, it is necessary to increase the tightening force between the T-shaped bolt 28 and the nut 29 to sufficiently compress the entire sealing material 25 in the tube axis direction. The tightening work required labor.

  An object of the present invention is to provide a pipe joint that is excellent in water tightness and can easily maintain high water tightness.

In order to achieve the above object, the first invention is a pipe joint in which an insertion opening formed at the end of one pipe is inserted into a receiving opening formed at the end of one pipe connected to each other. There,
On the inner peripheral surface of the receiving port, a fitting portion and a concave portion located on the back side of the fitting portion are formed,
A lock ring is provided on the back side of the recess in the receiving port,
A protrusion that can be engaged with the lock ring from the back of the receiving port is formed on the outer periphery of the insertion port,
The protrusion is formed at a position retracted in the extraction direction from the front end surface of the insertion opening,
Between the receiving port and the insertion port inserted in the receiving port is sealed over the entire circumference by an annular sealing material made of an elastic material,
At the opening end of the receiving port, a push ring for pushing the sealing material to the back side of the receiving port is detachably provided by a fastening means,
The press ring abuts on the opening end of the receiving port, and a press-fit groove is formed by the press ring and the fit-in part,
The sealing material has a heel portion that is fitted in the fitting groove, and a valve portion that is sandwiched between the inner peripheral surface of the receiving port and the outer peripheral surface of the insertion port,
The valve portion includes a first valve joined to the heel portion and pressed against the inner peripheral surface of the receiving port, and a second valve joined to the first valve and pressed against the outer peripheral surface of the insertion port,
A constriction is formed at the joint between the first valve and the second valve,
The second valve is inclined from the first valve toward the center of the pipe, the inner diameter is set smaller than the outer diameter of the insertion opening, and is expandable / contractable in the pipe radial direction by deformation of the constricted portion,
A gap is formed between the outer periphery of the second valve and the bottom surface of the recess ,
When the insertion port is inserted into the sealing material, first, the diameter of the second valve is increased while being pushed in the insertion direction by the distal end of the insertion port, and then when the insertion port is further inserted into the sealing material, When the protrusion passes through the inner periphery of the first valve and then the insertion port is further inserted into the sealing material, the protrusion of the insertion port passes through the inner periphery of the second valve .

  According to this, when joining one pipe | tube and the other pipe | tube, the insertion port of the other pipe | tube is inserted in the inner periphery of a push ring, and the inner periphery of a sealing material, and a sealing material is set to an insertion port. At this time, the constricted part thinner than the first and second valves is deformed, so that the second valve is enlarged (expanded) in the tube diameter direction by the insertion port, and the insertion port is inserted into the inner periphery of the sealing material. Therefore, the force required to expand the second valve in the pipe diameter direction is reduced.

  Thereafter, the insertion port of the other tube is inserted into the receiving port of one tube, the press ring is fastened to the opening end of the receiving port by fastening means, and the sealing material is pushed into the back side of the receiving port using the press ring. When the press ring comes into contact with the opening end portion of the receiving port, a fitting groove is formed by the push ring and the fitting portion of the receiving port, the heel portion of the sealing material is fitted into the fitting groove, and the first valve is the inner peripheral surface of the receiving port. And the second valve is in pressure contact with the outer peripheral surface of the insertion slot. Thereby, a sealing material is mounted | worn in the regular position in a receptacle, and the space | interval between a receptacle and an insertion port is sealed by the valve | bulb part of a sealing material.

When water pressure acts on the pipes joined to each other, water pressure also acts on the gap between the outer periphery of the second valve and the bottom surface of the recess, so that a pressing force toward the pipe center acts on the second valve, Since the second valve is strongly pressed against the outer peripheral surface of the insertion opening, it is possible to easily maintain high water tightness.
Moreover, it can prevent that an insertion port detaches | leaves from a receiving port by the protrusion part of an insertion port engaging a lock ring from a receiving port back side.
In the second invention, the constricted portion is thinner than the first and second valves.

Further, according to the third aspect of the present invention, a first seal portion that is in pressure contact with an inner peripheral surface of a convex portion formed between the fitting portion of the receiving port and the concave portion is formed on the outer peripheral portion of the first valve.
A second seal portion that is in pressure contact with the outer peripheral surface of the insertion port is formed on the inner peripheral portion of the second valve,
The position of the first seal part and the position of the second seal part are shifted in the tube axis direction.

  According to this, the heel portion of the sealing material is fitted in the fitting groove, the first seal portion of the first valve is pressed against the inner peripheral surface of the convex portion of the receiving port, and the second seal portion of the second valve is inserted. Press contact with the outer peripheral surface of the. As a result, the gap between the receiving port and the insertion port is sealed by the valve portion of the sealing material.

  When water pressure acts on the pipes joined to each other, an extruding force that pushes the valve portion from the back side of the receiving port to the near side acts on the tube axis direction by this water pressure. On the other hand, since the position of the first seal portion and the position of the second seal portion are shifted in the tube axis direction, the sealing material is pushed from the back side of the receiving port to the near side by the pushing force, and the insertion port Protruding from between the outer peripheral surface and the inner peripheral surface of the press ring can be prevented. In particular, the larger the amount of displacement in the tube axis direction between the position of the first seal portion and the position of the second seal portion, the greater the pushing force is, the sealing material becomes the outer peripheral surface of the insertion port and the inner peripheral surface of the press ring It can be prevented from protruding from between the two, and the water tightness is improved.

In the fourth aspect of the invention, the thickness of the first valve in the pipe radial direction is thinner than the thickness of the second valve in the pipe radial direction.
In the fifth invention, the thickness of the first valve in the pipe radial direction is thinner than the thickness of the second valve in the pipe radial direction.
The diameter of the cross section of the second valve is larger than the interval in the tube diameter direction between the inner peripheral surface of the convex portion of the receiving port and the outer peripheral surface of the insertion port.

  According to this, when one pipe and the other pipe are joined, the second valve passes through the convex portion of the receiving port and is inserted to the concave portion, and the valve portion is inserted from the back side of the receiving port by the water pressure in the pipe. Even if the pushing force to push forward is applied in the tube axis direction, the diameter of the cross section of the second valve is the tube diameter direction between the inner peripheral surface of the convex portion of the receiving port and the outer peripheral surface of the insertion port. Since it is larger than the interval, it is difficult for the second valve to pass the interval. Accordingly, it is possible to prevent the sealing material from being pushed from the back side of the receiving port to the near side and protruding from between the outer peripheral surface of the insertion port and the inner peripheral surface of the press ring.

  As described above, according to the present invention, it is possible to provide a pipe joint that is excellent in water tightness and can easily maintain high water tightness.

It is sectional drawing of the pipe joint in embodiment of this invention. It is sectional drawing which shows the procedure at the time of mounting | wearing with a sealing material to a pipe joint. It is a cross-sectional view in the natural state (non-compressed state in which the sealing material is removed from the pipe joint) of the sealing material provided in the pipe joint. It is the cross-sectional view which showed the dimension of each part in the natural state (The uncompressed state which removed the sealing material from the pipe joint) of the sealing material provided to a pipe joint similarly. It is sectional drawing which shows the procedure at the time of setting a sealing material and a push ring to the insertion opening of a pipe joint. It is sectional drawing of the conventional pipe joint.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, reference numeral 31 denotes a mechanical-type detachment prevention pipe joint, which is connected to the receiving port 33 formed at the end of one of the pipes 32 connected to each other and to the end of the other pipe 34. The formed insertion slot 35 is inserted.

  The inner peripheral surface of the receiving port 33 is fitted with a fitting portion 37, a concave portion 38 positioned on the deeper side of the receiving port than the fitting portion 37, and a lock ring receiving groove 39 positioned on the deeper side of the receiving port than the concave portion 38. The convex part 40 located between the part 37 and the recessed part 38 is each formed over the perimeter.

  The fitting portion 37 is a recess opened to the inner peripheral surface and the end surface of the receiving port 33. A rear end surface 41 in the tube radial direction is formed inside the receiving port 33 that is spaced from the lock ring housing groove 39 to the back side.

  The lock ring housing groove 39 accommodates a metal-made circumferentially divided lock ring 42. The lock ring 42 is configured to elastically hold on the outer peripheral surface of the insertion opening 35 by having an elastic diameter reducing force. A centering rubber body 43 is disposed between the outer peripheral surface of the lock ring 42 and the bottom surface of the lock ring receiving groove 39, and the lock ring 42 is received when the insertion port 35 is not inserted into the reception port 33. 33 can be held in a centered state. Further, a protrusion 44 that can be engaged with the lock ring 42 from the back of the receiving port is formed on the outer periphery of the distal end of the insertion port 35. Note that the protrusion 44 is formed at a position retracted in the extraction direction by a predetermined distance from the distal end surface of the insertion opening 35.

  The space between the receiving port 33 and the insertion port 35 is made of rubber (an example of an elastic material) and sealed around the entire circumference by an annular sealing material 45. A radially outward flange 59 is formed on the outer periphery of the opening end of the receiving port 33. On the flange 59 of the receiving port 33, an annular push ring 60 that pushes the sealing material 45 to the back side of the receiving port is detachably provided by a plurality of bolts 61 (an example of fastening means) and nuts 62 (an example of fastening means). Yes. The pusher wheel 60 is in contact with the opening end surface of the receiving port 33, and a fitting groove 63 is formed by the fitting part 37 and the pusher wheel 60. The insertion opening 35 is inserted through the inner periphery of the push wheel 60.

  As shown in FIGS. 1, 3, and 4, the seal member 45 is a valve that is sandwiched between the heel portion 46 fitted in the fitting groove 63, and the inner peripheral surface of the receiving port 33 and the outer peripheral surface of the insertion port 35. Part 47. The heel portion 46 is an annular member whose transverse cross-sectional shape (cross-sectional shape perpendicular to the circumferential direction) is square.

  The valve portion 47 is an annular member and includes a first valve 48 and a second valve 49 that are joined to each other. The cross-sectional shape of the first valve 48 is an oval shape that is long in the tube axis direction and has semicircular portions with a radius r1 at both ends. The second valve 49 has a circular cross section with a radius r2. The radius r1 is smaller than the radius r2, and the thickness T1 of the first valve 48 is thinner than the thickness T2 of the second valve 49. The diameter (= 2 × r2) of the cross section of the second valve 49 is formed larger than the interval S in the tube diameter direction between the inner peripheral surface of the convex portion 40 and the outer peripheral surface of the insertion opening 35.

  The first valve 48 is joined to the heel portion 46, and a recess 52 is formed on the outer peripheral portion of the joint portion between the first valve 48 and the heel portion 46. The inner diameter of the first valve 48 is slightly smaller than the outer diameter of the insertion port 35, and the outer diameter of the first valve 48 is slightly larger than the inner diameter of the convex portion 40.

  The heel portion 46 is located on the front side opposite to the back side of the receiving port 33 with respect to the first valve 48. In addition, a constricted portion 53 that is thinner than the first and second valves 48 and 64 is formed at a joint portion between the first valve 48 and the second valve 49. Arc concavities 54 and 55 are formed on the inner peripheral surface and the outer peripheral surface of the constricted portion 53, respectively.

  The second valve 49 is located on the back side of the receiving port 33 with respect to the first valve 48 and is inclined from the first valve 48 toward the tube center. As shown in FIG. 4, a surface including the center P1 of the semicircular portion of the end portion of the first valve 48 near the second valve 49 and the center P2 of the second valve 49 is L1, and includes the center P1. Further, assuming that the radial surface of the sealing material 45 is L2, the inclination angle M of the surface L1 with respect to the surface L2 is set to 15 to 35 °. Furthermore, the inner diameter d of the second valve 49 is set to be smaller than the outer diameter D of the insertion opening 35, and the second valve 49 can be expanded and contracted in the tube diameter direction by elastic deformation of the constricted portion 53. Further, the inner diameter J of the heel portion 46 is set larger than the inner diameter K of the first valve 48.

  A first seal portion 50 that is in pressure contact with the inner peripheral surface of the convex portion 40 (the inner peripheral surface of the receiving port 33) is formed on the entire outer periphery of the first valve 48. A second seal portion 51 that is in pressure contact with the outer peripheral surface of the insertion port 35 is formed on the inner peripheral portion of the second valve 49 over the entire periphery. The position of the first seal portion 50 and the position of the second seal portion 51 are shifted in the tube axis direction. Further, as shown in FIG. 1, a gap 64 is formed over the entire circumference between the outer periphery of the second valve 49 and the bottom surface of the recess 38 in the tube diameter direction. The length of the convex portion 40 in the tube axis direction is set to a length that does not compress the second valve 49. The heel portion 46 is formed of rubber that is harder than the valve portion 47.

Hereinafter, the operation of the above configuration will be described.
When the one pipe 32 and the other pipe 34 are joined, the lock ring 42 and the centering rubber body 43 are accommodated in the lock ring accommodating groove 39 in advance. Then, as shown in FIG. 5A, the insertion opening 35 is first inserted into the inner periphery of the push wheel 60 and then inserted into the inner periphery of the sealing material 45. At this time, as shown in FIG. 5 (b), the tip of the insertion port 35 is inserted into the inner periphery of the first valve 48, contacts the second valve 49, and the second valve 49 is pushed, whereby the second valve 49 is pushed. The valve 49 is expanded (expanded) in the tube diameter direction.

  Thereafter, when the insertion slot 35 is further inserted, the projection 44 of the insertion slot 35 abuts the inner circumference of the first valve 48 through the inner circumference of the heel portion 46 as shown in FIG. Thereafter, as shown in FIG. 5 (d), the inner periphery of the first valve 48 passes through the inner periphery of the second valve 49. At this time, the second valve 49 is displaced outward in the pipe diameter direction with respect to the protrusion 44. Thereafter, as shown in FIGS. 5 (e) and 2 (a), the protrusion 44 of the insertion port 35 passes through the inner periphery of the second valve 49, and the insertion port 35 is inserted into the inner periphery of the sealing material 45. The sealing material 45 is set in the insertion slot 35.

  When the insertion port 35 is inserted into the inner periphery of the sealing material 45 as described above, the constricted portion 53 thinner than the first and second valves 48 and 49 is elastically deformed, so that the second valve 49 is in the radial direction. Since the expansion (expansion) is performed, the force required to expand the second valve 49 in the pipe diameter direction is reduced, thereby reducing the insertion force required when the insertion port 35 is inserted into the inner periphery of the sealing material 45. can do.

  Further, as shown in FIG. 5B, first, the distal end of the insertion opening 35 expands the second valve 49 in the tube diameter direction, and then, as shown in FIGS. Passes through the first valve 48, the second valve 49 does not expand in the pipe radial direction and the projection 44 passes through the first valve 48 at the same time. The insertion force required when inserting into the inner periphery of the sealing material 45 can be reduced.

After that, as shown in FIG. 2B, a predetermined amount of the insertion port 35 is inserted into the receiving port 33, and the protrusion 44 of the insertion port 35 is passed from the front side of the lock ring 42 toward the back side of the receiving port.
Next, the press wheel 60 is fastened to the flange 59 by the plurality of bolts 61 and the nuts 62. At this time, the operator tightens the nut 62 until the pusher wheel 60 comes into contact with the opening end surface of the receiving port 33, so that the sealing material 45 is placed on the inner periphery of the opening end portion of the receiving port 33 as shown in FIG. It is pushed between the outer periphery of the insertion opening 35 and set at a proper position, and the heel portion 46 is fitted into a fitting groove 63 formed by the fitting portion 37 and the push wheel 60, and one tube 32 and the other tube 34. And are joined.

  At this time, the second valve 49 is in an expanded (expanded) state in the tube diameter direction, and therefore sticks to the outer peripheral surface of the insertion port 35 and is attached to the expanded diameter of the second valve 49. Is pushed outward in the pipe radial direction. As a result, the first seal portion 50 of the first valve 48 is pressed against the inner peripheral surface of the convex portion 40 (the inner peripheral surface of the receiving port 33), and the second seal portion 51 of the second valve 49 is connected to the insertion port 35. Since it press-contacts to an outer peripheral surface, high watertightness can be maintained between the receiving port 33 and the insertion port 35. FIG.

  In addition, when the sealing material 45 is pushed between the receiving port 33 and the insertion port 35 as described above, the first valve 48 has an oval cross-sectional shape, and the second valve 49 has a circular cross-sectional shape. Therefore, the resistance is reduced and the valve portion 47 is easily pushed.

  Further, when water pressure acts in the pipes 32 and 34 joined to each other, as shown in FIG. 1, an extrusion force F1 for pushing the valve portion 47 from the back side of the receiving port 33 to the front side by this water pressure is generated. Acts in the tube axis direction. On the other hand, since the position of the first seal portion 50 and the position of the second seal portion 51 are displaced in the tube axis direction, the sealing material 45 is pushed from the back side to the front side of the receiving port 33 by the pushing force F1. Thus, it is possible to prevent the protrusion 35 from protruding from between the outer peripheral surface of the insertion opening 35 and the inner peripheral surface of the push ring 60. In particular, as the displacement A in the tube axis direction between the position of the first seal portion 50 and the position of the second seal portion 51 is increased, the sealing material 45 becomes closer to the outer peripheral surface of the insertion opening 35 with respect to a larger pushing force F1. It is possible to prevent the press ring 60 from protruding from the inner peripheral surface. Thereby, the watertightness between the receiving port 33 and the insertion port 35 is improved.

  The second valve 49 is inserted through the convex portion 40 of the receiving port 33 to the concave portion 38, and the diameter (= 2 × r 2) of the cross section of the second valve 49 is equal to the inner peripheral surface of the convex portion 40. Since it is larger than the interval S in the tube diameter direction with respect to the outer peripheral surface of the insertion opening 35, even if the valve portion 47 is pushed by the pushing force F1, the second valve 49 is difficult to pass the interval S. It is possible to prevent the material 45 from being pushed from the back side to the front side of the receiving port 33 and protruding from between the outer peripheral surface of the insertion port 35 and the inner peripheral surface of the pusher wheel 60.

  Further, since water pressure also acts on the gap 64, a pressing force F <b> 2 directed toward the center of the tube acts on the second valve 49, whereby the second seal portion 51 of the second valve 49 acts on the outer peripheral surface of the insertion port 35. The water tightness between the receiving port 33 and the insertion port 35 is further improved.

  In the above embodiment, as shown in FIG. 1, when the insertion port 35 is inserted into the receiving port 33 and one tube 32 and the other tube 34 are joined, the inner peripheral surface of the first valve 48 is Although it contacts the outer peripheral surface of the insertion port 35, a gap may be formed between the inner peripheral surface of the first valve 48 and the outer peripheral surface of the insertion port 35. In this case, when the valve portion 47 is pushed by the pushing force F1, the second valve 49 is pushed so as to enter the gap between the inner peripheral surface of the first valve 48 and the outer peripheral surface of the insertion port 35. And the watertightness between the insertion opening 35 is further improved.

In the above-described embodiment, the annular integrated pusher wheel 60 is used. However, the pusher wheel 60 may be divided into a plurality of parts (for example, divided into two parts).
In the above embodiment, the cross-sectional shape of the first valve 48 is oval, but it may be circular.

31 pipe joint 32 one pipe 33 receiving port 34 other pipe 35 insertion port 37 fitting part 38 concave part 40 convex part 42 lock ring 44 projecting part 45 sealing material 46 heel part 47 valve part 48 first valve 49 second valve 50 first 1 seal part 51 second seal part 53 constricted part 60 push ring 61 bolt (fastening means)
62 Nut (fastening means)
63 Insertion groove 64 Gap d Inner diameter D of second valve Outer diameter T1 First valve thickness T2 Second valve thickness S Interval

Claims (5)

A pipe joint that inserts an insertion opening formed at the end of the other pipe into a receiving opening formed at the end of one pipe connected to each other,
On the inner peripheral surface of the receiving port, a fitting portion and a concave portion located on the back side of the fitting portion are formed,
A lock ring is provided on the back side of the recess in the receiving port,
A protrusion that can be engaged with the lock ring from the back of the receiving port is formed on the outer periphery of the insertion port,
The protrusion is formed at a position retracted in the extraction direction from the front end surface of the insertion opening,
Between the receiving port and the insertion port inserted in the receiving port is sealed over the entire circumference by an annular sealing material made of an elastic material,
At the opening end of the receiving port, a push ring for pushing the sealing material to the back side of the receiving port is detachably provided by a fastening means,
The press ring abuts on the opening end of the receiving port, and a press-fit groove is formed by the press ring and the fit-in part,
The sealing material has a heel portion that is fitted in the fitting groove, and a valve portion that is sandwiched between the inner peripheral surface of the receiving port and the outer peripheral surface of the insertion port,
The valve portion includes a first valve joined to the heel portion and pressed against the inner peripheral surface of the receiving port, and a second valve joined to the first valve and pressed against the outer peripheral surface of the insertion port,
A constriction is formed at the joint between the first valve and the second valve,
The second valve is inclined from the first valve toward the center of the pipe, the inner diameter is set smaller than the outer diameter of the insertion opening, and is expandable / contractable in the pipe radial direction by deformation of the constricted portion,
A gap is formed between the outer periphery of the second valve and the bottom surface of the recess ,
When the insertion port is inserted into the sealing material, first, the diameter of the second valve is increased while being pushed in the insertion direction by the distal end of the insertion port, and then when the insertion port is further inserted into the sealing material, A pipe joint , wherein a protrusion passes through the inner periphery of the first valve, and then, when the insertion port is further inserted into the sealing material, the protrusion of the insertion port passes through the inner periphery of the second valve . The pipe joint according to claim 1, wherein the constricted portion is thinner than the first and second valves . A first seal portion is formed on the outer peripheral portion of the first valve to press-contact the inner peripheral surface of the convex portion formed between the fitting portion of the receiving port and the concave portion,
A second seal portion that is in pressure contact with the outer peripheral surface of the insertion port is formed on the inner peripheral portion of the second valve,
The pipe joint according to claim 1 or 2, wherein the position of the first seal part and the position of the second seal part are shifted in the pipe axis direction . The pipe joint according to any one of claims 1 to 3, wherein a thickness of the first valve in the pipe radial direction is thinner than a thickness of the second valve in the pipe radial direction . The thickness of the first valve in the radial direction is thinner than the thickness of the second valve in the radial direction,
The diameter of the cross section of a 2nd valve | bulb is larger than the space | interval of the pipe radial direction of the internal peripheral surface of the convex part of a receiving port, and the outer peripheral surface of an insertion port, The pipe joint of Claim 3 characterized by the above-mentioned .

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