JP2011169335A - Compression caulking pipe joint, and connecting structure between compression caulking pipe joint and resin pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compression caulking pipe joint in which water leakage is surely found during initial water pressure test when a caulking failure occurs during construction, causing no coming-off of a resin pipe, nor water leakage from a connection portion even after long-period use if normal caulking work is done, and to provide a connecting structure between the compression caulking pipe joint and the resin pipe. <P>SOLUTION: A nozzle part 23 with the maximum outer diameter smaller than the inner diameter of the resin pipe P has at least one ring-shaped sealing material fitting groove 23a formed in a portion corresponding to the caulking position of a sleeve 3. Into the sealing material fitting groove 23a, a ring-shaped sealing material 24 is fitted so that its maximum height from the bottom of the sealing material fitting groove 23a is lower than the upper end of either side wall of the sealing material fitting groove 23a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a compression caulking pipe joint and a connection structure between the compression caulking pipe joint and a resin pipe.

The inner and outer layers are sandwiched between aluminum core layers used for cold and hot water piping of air-conditioning equipment such as cross-linked polyethylene pipes, polybutene pipes, and fan coils as pipes for water supply and hot water supply piped under the floors of detached houses and apartment buildings. Resin pipes such as metal reinforced polyethylene pipes (for example, trade name ESLON SUPER ETHROMETAX manufactured by Sekisui Chemical Co., Ltd.) in which a polyethylene resin layer is formed are used.
And in order to connect these resin pipes and rigid pipes, such as a metal pipe piped outdoors, the compression caulking pipe joint 200 as shown in FIG. 10 is used (for example, patent document 1). reference).

As shown in FIG. 10, the compression caulking pipe joint 200 includes a sleeve 210 and a joint body 220. The joint main body 220 includes a nozzle portion 221 surrounded by the sleeve 210.
The compression caulking pipe joint 200 inserts the end portion of the resin pipe P between the nozzle portion 221 and the sleeve 210 and uses a dedicated caulking die 110 set on a caulking tool (not shown) to form the sleeve 210. The resin pipe P can be connected in a watertight manner by caulking the caulking portions (three places indicated by dotted arrows in the figure).

That is, the nozzle portion 221 has a ring-shaped sealing material fitting groove 222 at a position corresponding to the caulking portion of the sleeve 210, and the ring-shaped sealing material 223 is fitted into the ring-shaped sealing material fitting groove 222. ing.
The resin pipe P is deformed by caulking so that the portion corresponding to the caulking position of the sleeve 210 is reduced in diameter toward the nozzle portion 221, and the inner wall surface of the deforming portion is pressed against the ring-shaped sealing material 223 and compressed. It is connected to the caulking pipe joint 200 in a watertight manner.

JP 2005-325904 A

By the way, in the conventional compression caulking pipe joint 200, since the outer diameter of the ring-shaped sealing material 223 is larger than the inner diameter of the resin pipe P to be connected, the resin pipe P is simply inserted between the nozzle portion 221 and the sleeve 210. Thus, the ring-shaped sealing material 223 comes into close contact with the inner wall surface of the resin pipe P, and watertightness is exhibited.
Therefore, even if forgetting caulking at the time of construction, there is a problem that it does not leak at the initial water pressure test, and the resin pipe P comes out after use or water leaks from the connection portion.

  In view of the above circumstances, in the case of forgetting caulking at the time of construction, the present invention surely causes water leakage during the initial water pressure test, and if normal caulking is performed, even after long-term use, the resin tube comes off, It is an object of the present invention to provide a compression caulking pipe joint that does not leak water from a connecting portion, and a connection structure between the compression caulking pipe joint and a resin pipe.

  In order to achieve the above object, a compression caulking pipe joint according to the present invention is a resin pipe connected between a nozzle portion provided at one end of the pipe joint and a sleeve arranged so as to surround the nozzle portion. A compression caulking pipe joint in which the end of the resin pipe is sandwiched between the sleeve and the nozzle part by caulking with a dedicated caulking die, and the nozzle part is There is a ring-shaped sealing material fitting groove in the portion corresponding to the caulking position of the sleeve, and the maximum height from the bottom of the sealing material fitting groove is on both side walls of the sealing material fitting groove. A ring-shaped sealing material that is located at a position lower than the upper end of each is fitted.

In the present invention, the ring-shaped sealing material is not particularly limited, but preferably has a cross-sectional shape that is compressed at a compression rate of 5 to 65% in a normal caulking state with a dedicated caulking die.
In the present invention, the compression ratio is defined by the maximum height of the ring-shaped sealing material from the bottom of the sealing material fitting groove before caulking H1, and the sealing material fitting groove after caulking from the bottom of the sealing material fitting groove. L is the shortest distance to the inner wall surface of the resin tube facing the surface [(calculated by the minimum inner diameter of the resin tube facing the sealing material fitting groove after caulking−the diameter of the bottom portion of the sealing material fitting groove) / 2] Is calculated by the following equation (1).
Compression rate = (H1−L) / H1 × 100 (1)

In addition, the connection structure between the compression crimped pipe joint and the resin pipe of the present invention is not particularly limited, but the pair of two semi-arc-shaped linear crimping portions do not exist in the same plane, and both It is preferable to have a connection structure in which the resin pipe and the compression caulking pipe joint are connected by caulking and forming at the caulking position of the sleeve so that both ends of the arc of the linear caulking part are three-dimensionally overlapped.
In the connection structure, the two linear caulking portions to be paired do not have to be on the same plane. However, in consideration of water-stopping, the distance in the tube axis direction between the two linear caulking portions is as close as possible. Is preferred.

  As described above, the compression caulking pipe joint according to the present invention is an end part of a resin pipe connected between a nozzle part provided at one end of the pipe joint and a sleeve arranged so as to surround the nozzle part. And inserting the end of the resin tube between the sleeve and the nozzle portion in a water-tight manner by caulking the caulking position provided in at least part of the axial direction of the sleeve using a dedicated caulking die. The nozzle portion has a ring-shaped sealing material fitting groove in a portion corresponding to the caulking position of the sleeve, and the sealing material fitting groove is provided in the sealing material fitting groove. The ring-shaped seal material is installed so that the maximum height from the bottom of the seal is lower than the upper ends of both side walls of the seal material fitting groove. Water leaks, If normal crimping is performed, even after prolonged use, or missing resin tube, there is no or to leak from the connecting part.

  In addition, in a state where it is not crimped, the ring-shaped sealing material whose outer diameter is smaller than the diameter of the upper peripheral edge of the side wall of the sealing material fitting groove is fitted into the sealing material fitting groove. If only the end portion of the resin tube is inserted between the inner peripheral surface of the resin tube, a gap is always generated between the inner peripheral surface of the resin tube and the outer peripheral surface of the nozzle portion and the ring-shaped sealing material. Therefore, if the caulking is forgotten, water leaks through the inner peripheral surface of the resin tube and the outer peripheral surface of the ring-shaped sealing material when the initial water pressure test is performed.

In addition, since the maximum height of the ring-shaped sealing material from the bottom of the sealing material fitting groove is lower than the upper ends of both side walls of the sealing material fitting groove, the resin pipe is placed between the sleeve and the nozzle part. At the time of insertion, so-called deringing in which the end of the resin tube contacts the ring-shaped sealing material and damages the link-shaped sealing material or separates from the sealing material fitting groove does not occur. That is, there is no problem of water stoppage due to damage to the link-shaped sealing material or separation from the sealing material fitting groove.
Further, in the connection structure between the compression crimped pipe joint and the resin pipe of the present invention, the two linear arc-shaped caulking portions that are paired do not exist in the same plane, and both the linear caulking portions If the connection structure is formed by caulking the sleeve so that both ends of the arc are three-dimensionally overlapped and the resin pipe and the compression caulking joint are connected, water can be stopped more reliably.
That is, since the two linear caulking portions that are paired do not exist in the same plane, a curved portion due to the ends of both linear caulking portions abutting at the time of caulking does not occur in the sleeve. Since both ends of the arcs of the two linear caulking portions are three-dimensionally overlapped, the caulking portion of the sleeve seems to be caulked to a perfect circle. Therefore, the entire circumference of the sleeve is caulked almost uniformly, and there is no problem of water stoppage failure due to uneven caulking.

It is a perspective view showing one embodiment of a compression caulking pipe joint concerning the present invention. It is sectional drawing of the compression crimping fitting of FIG. It is a principal part expanded sectional view of FIG. It is a front view showing one example of the caulking tool used for the compression caulking pipe joint of the present invention. It is a perspective view of a state before butting the butting | matching surface of the division | segmentation die | dye of the caulking die with which the caulking tool of FIG. 4 is mounted | worn. FIG. 6 is a perspective view of a state in which the butting surfaces of the split dies of the caulking die of FIG. 5 are butted. It is the figure which looked at FIG. 5 from the axial direction. It is a figure explaining the method of connecting the compression caulking pipe joint and resin pipe of FIG. 1 using the caulking tool of FIG. 4 and the caulking die shown in FIGS. It is a front view of the state which connected the compression caulking pipe joint and resin pipe of FIG. 1 using the caulking tool of FIG. 4 and the caulking die shown in FIGS. It is a half sectional view of the state where the resin pipe of the conventional compression caulking pipe joint is connected.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.
FIG. 1 and FIG. 2 show one embodiment of a compression caulking fitting according to the present invention.

As shown in FIG. 1 and FIG. 2, the compression caulking pipe joint 1 includes a joint body 2 and a sleeve 3.
The joint body 2 is made of brass, gun metal, stainless steel, or the like, and has a hexagonal nut-shaped flange portion 21, a male screw cylinder portion 22 connected to one of the flange portions 21, and the other flange portion 21. And a nozzle portion 23 provided continuously.

As shown in FIG. 2, the nozzle portion 23 has a maximum outer diameter smaller than the inner diameter of the resin pipe P to be connected, and when the sleeve 3 is caulked with a dedicated caulking die described later, a position corresponding to the caulking position at the center. The ring-shaped sealing material fitting groove 23a is provided, and the outer peripheral surfaces on both sides sandwiching the sealing material fitting groove 23a are formed in a serrated uneven shape.
A ring-shaped sealing material 24 is fitted in the sealing material fitting groove 23a.

The ring-shaped sealing material 24 is made of synthetic rubber such as EPDM (ethylene-propylene-diene copolymer), and as shown in FIG. 3, the sealing material is fitted in the sealing material fitting groove 23a. The maximum height H1 from the bottom of the fitting groove 23a is formed to be lower than the height H2 from the bottom of the sealing material fitting groove 23a to the upper ends of both side walls of the sealing material fitting groove 23a.
The cross-sectional shape is an uncompressed state, the dimension in the thickness direction of the ring is slightly smaller than the groove width of the seal material fitting groove 23, and the maximum height H1 portion is the nozzle from the center position in the thickness direction (center axis direction) of the ring. The section 23 has a substantially semi-cylindrical shape slightly shifted to the tip side.
Further, when the resin pipe P is normally connected as will be described later, the ring-shaped sealing material 24 is elastically deformed so that the compressibility becomes 5 to 65% as shown by a two-dot chain line in FIG. Is formed.

The sleeve 3 is formed of stainless steel or aluminum, and includes a sleeve main body 31 and a circular flange 32 that is connected to one end of the sleeve main body 31.
As shown in FIG. 2, the sleeve body 31 has an inner diameter that is substantially the same as or slightly larger than the outer diameter of the resin tube P, and the other end is provided on the nozzle portion 23 side of the flange portion 21 of the joint body 2. The ring-like fitting groove 21a is fitted and integrated.
The circular flange 32 is provided so as to spread from one end of the sleeve body 31 in the outer circumferential direction.

In this compression caulking pipe joint 1, for example, the sleeve 3 is caulked using a dedicated caulking die 5 shown in FIGS. 5 to 7 attached to a caulking tool 4 as shown in FIG. 4.
As shown in FIGS. 5 to 7, the caulking die 5 is composed of two divided dies 5 a.
Each of the two divided dies 5 a includes a caulking concave portion 51 having a substantially semi-cylindrical shape, and abutting surfaces 52 provided on both sides of the caulking concave portion 51.

Moreover, both the split dies 5a have a concavo-convex shape in which the butt surface 52 is formed by alternately forming the butt convex surface 52a and the butt concave surface 52b in the axial direction, and the butt convex surface 52a of one split die 5a is the other split die. It abuts on the abutting concave surface 52b of 5a.
On the inner wall surface of the caulking recess 51, three caulking protrusions 53 each having a semicircular arc shape are provided in parallel. And the corner part with the abutting surface 52 of the caulking recessed part 51 containing the caulking protrusion 53 is chamfered by the curved shape.

Each caulking ridge 53 is a corner portion between the inner wall surface of the caulking concave portion 51 and the butt convex surface 52a so as to follow both end edges of the protrusion 52c forming the butt convex surface 52a and the inner edge of the end protrusion 52d. Each is provided to reach.
Further, in a state where the two split dies 5a are set on the caulking tool 4, the caulking ridge 53 of one split die 5a and the caulking ridge 53 of the other split die 5a are paired one by one. A direction in which the pair of caulking ridges 53 are orthogonal to the axis of the caulking concave portion 51 in the state in which the butting convex surfaces 52a and the butting concave surfaces 52b of both split dies 5a are abutted (direction of arrow X in FIG. 6). When projected from above, the two ends of the caulking ridges 53 that are paired with each other are displaced in the axial direction of the caulking concave portion 51 so that they are not projected in an overlapping manner, as shown in FIG. Will be overlapped. That is, it seems that the caulking ridges 53 forming a pair form a substantially circular shape. Further, the caulking ridges 53 forming a pair at the center are arranged at a position facing directly above the ring-shaped sealing material 24 during caulking.

  Next, a method of connecting the resin pipe P to the compression caulking fitting 1 using the caulking die 5 attached to the caulking tool 4 will be described in detail with reference to FIG.

(1) As shown in FIG. 8A, the end portion of the resin pipe P is inserted between the sleeve 3 and the nozzle portion 23.
At this time, the compression caulking pipe joint 1 is such that the maximum outer diameter of the nozzle portion 23 is smaller than the inner diameter of the resin pipe P, and the outer diameter of the ring-shaped sealing material 24 is larger than the diameter of the upper peripheral edge of the side wall of the sealing material fitting groove 23a. Since it has a small diameter, in this inserted state, a gap in which water leaks surely occurs when a water pressure test is performed between the resin pipe P and the nozzle part 23 and the ring-shaped sealing material 24.

(2) As shown in FIG. 8 (a), the compression caulking pipe joint 1 in which the resin pipe P is set as described above is placed between two divided dies 5a (in FIG. 8 (a), one side divided dies 5a After the caulking tool 4 is arranged so that the sleeve main body 31 portion is sandwiched between them, the lever 41 of the caulking tool 4 is operated to move one split die 5a toward the other split die 5a. As shown in FIG. 8B, the sleeve main body 31 is caulked.
By this caulking, the sleeve main body 31 is caulked by the three pairs of caulking ridges 53 at the portion directly above the sealing material fitting groove 23a and the uneven portion sandwiching the sealing material fitting groove 23a.
Then, when the sleeve 3 is caulked, the resin pipe P is deformed in a ring shape toward the nozzle portion 23 at a portion corresponding to the caulking ridge 53. That is, the resin pipe P is a portion corresponding to the caulking ridge 53 that forms a pair at the center, and as shown in FIGS. 3 and 8B, a part on the inner wall surface side is formed in the seal material fitting groove 23a. The ring-shaped sealing material 24 is compressed and deformed so as to have a compression rate of 5 to 65% and firmly stops the water. On the other hand, as shown in FIG. The resin pipe P is prevented from coming off by being compressed and deformed so that a part on the inner wall surface side bites into the concavo-convex shape part sandwiching the sealing material fitting groove 23a at the part corresponding to the stripe 53.

As described above, the compression caulking pipe joint 1 has the maximum outer diameter of the nozzle portion 23 smaller than the inner diameter of the resin pipe P, and the outer diameter of the ring-shaped sealing material 24 is the upper peripheral edge of the side wall of the sealing material fitting groove 23a. Therefore, in this inserted state, there is a gap in which water leakage is surely generated when the water pressure test is performed between the resin pipe P and the nozzle portion 23 and the ring-shaped sealing material 24. . Therefore, it is possible to reliably detect forgetting in the initial hydraulic pressure test. Of course, if normal caulking is performed, the resin pipe P will not come out and water will not leak from the connected portion even after long-term use.
Further, if the caulking die 5 is used for caulking, the caulking portion can be caulked with a light force, and a curved surplus portion is not formed in the caulking portion, so that compression does not become uneven in the circumferential direction. In addition, the reliability of the joint against water leakage and the like is improved.
In addition, since the outer diameter of the ring-shaped sealing material 24 is smaller than the diameter of the upper peripheral edge of the side wall of the sealing material fitting groove 23a, the compression caulking pipe joint 1 has a resin pipe P in order to ensure water-stopping. The inner wall must be reduced in diameter so as to enter the sealing material fitting groove 23a. That is, it is necessary to increase the diameter reduction amount of the caulking portion of the sleeve 3 and the resin pipe P by caulking, but if the caulking die 5 is used, a necessary large diameter reduction amount can be sufficiently ensured.

  That is, in the caulking die 5, when one split die 5 a is moved in the direction of the other split die 5 a, first, both ends of the caulking ridge 53 hit the wall surface of the sleeve 53. Since the edge is chamfered in a curved shape, the sleeve 53 smoothly enters the caulking concave portion 51 with a light force, and the portion that contacts the caulking ridge 53 is caulked as shown in FIG. A linear caulking portion 34 is formed. Then, the wall surface of the resin pipe P is compressed and deformed by the linear caulking portion 34. Further, if the positions of the caulking ridges 53 that are paired are overlapped, when the caulking ridges 53 are caulked, the surplus portion of the sleeve body 31 becomes a curved shape in the vicinity of the abutting surface. The caulking ridges 53 forming a pair of the split dies 5a are displaced in the axial direction of the caulking concave portions 51. That is, they are not on the same plane, and the butt convex surfaces 52a and the butt concave surfaces 52b of both the split dies 5a are abutted. Since it becomes a state, as for the linear crimping part 34 used as a pair, the edge part does not collide. Therefore, a curved surplus portion is not formed in the caulking portion, and compression does not become uneven in the circumferential direction.

  Further, when viewed from the axial direction of the caulking recess 51, both ends of the caulking ridges 53 forming a pair overlap each other, and the caulking ridges 53 forming a pair appear to form a substantially circular shape, that is, caulking. Since the caulking ridges 53 are formed such that both ends of the ridges 53 overlap in a three-dimensional manner, the ends of the linear caulking portions 34 formed by the pair of caulking ridges 53 also overlap in a three-dimensional manner. Therefore, the water stopping property is high.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, there is one seal material fitting groove, but two or more seal material fitting grooves may be provided, and ring-shaped seal materials may be fitted respectively.
In the above embodiment, the resin tube is inserted between the sleeve and the nozzle portion, and then the sleeve is set between the divided dies. A resin tube may be inserted between the sleeve and the nozzle portion after being held by the die tool so as to be set between the divided dies.

  Specific examples and comparative examples of the present invention will be described below.

(Example 1)
A compression crimped pipe joint having the shape shown in FIGS. 1 and 2 having the following dimensions is prepared, and the produced compression crimped pipe joint and resin pipe (metal reinforced polyethylene pipe manufactured by Sekisui Chemical Co., Ltd., Super Ethromex) φ16 (outer diameter: φ20.1 mm, wall thickness 2.25 mm) was connected as follows.
Nozzle section maximum outer diameter (diameter of upper edge of side wall of seal material fitting groove): φ15.22mm
Diameter of bottom of sealing material fitting groove: φ10.6mm
Sleeve inner diameter: φ20.3mm
Sleeve wall thickness: 0.5mm
Height from the bottom of the seal material fitting groove of the ring-shaped seal material to the highest position: 2.29 mm
Note that the compression caulking pipe joint produced as described above has a sleeve inner diameter larger than the outer diameter of the resin pipe and a nozzle portion maximum outer diameter smaller than the inner diameter of the resin pipe. Further, the upper end of the ring-shaped sealing material does not protrude from the sealing material fitting groove.
Then, when the resin pipe was inserted between the sleeve and the nozzle portion of the compression caulking pipe joint, the resin pipe could be inserted smoothly without resistance until the end face of the resin pipe hits the step of the joint body.
Next, in this inserted state, when trying to apply water pressure without compressing and crimping the sleeve with a die, water may leak from between the resin pipe and the compression caulking fitting just by passing water. It could be confirmed.
Subsequently, the sleeve was caulked with an exclusive die having the shape shown in FIGS. 5 to 7 (caulking ridge inner diameter: φ19.3 mm), and the resin pipe and the compression caulking pipe joint were connected.
In this state, short-term water pressure test (23 ℃ × 1.75MPa × 2 minutes) and long-term hydrostatic pressure test (95 ℃ × 1.35MPa × 1000 hours) were conducted. There wasn't.
In addition, the resin pipe minimum inner diameter of the ring-shaped sealing material contact portion reduced in diameter by compression caulking was φ14.13 mm, and the compression ratio of the ring-shaped sealing material was 22.3%.

(Example 2)
A compression crimped pipe joint having the shape shown in FIGS. 1 and 2 with the dimensions of each part as shown below was prepared, and the produced compression crimped pipe joint and resin pipe (Sekisui Chemical Co., Ltd., Super Eslometax φ16 (outer diameter : Φ20.1 mm, wall thickness 2.25 mm)) were connected as follows.
Nozzle section maximum outer diameter (diameter of upper edge of side wall of seal material fitting groove): φ15.22mm
Diameter of bottom part of sealing material fitting groove: φ10.57mm
Sleeve inner diameter: φ20.25mm
Sleeve thickness: 0.45mm
Height from the bottom of the seal material fitting groove of the ring-shaped seal material to the highest position: 2.20mm
Note that the compression caulking pipe joint produced as described above has a sleeve inner diameter larger than the outer diameter of the resin pipe and a nozzle portion maximum outer diameter smaller than the inner diameter of the resin pipe. Further, the upper end of the ring-shaped sealing material does not protrude from the sealing material fitting groove.
Then, when the resin pipe was inserted between the sleeve and the nozzle portion of the compression caulking pipe joint, the resin pipe could be inserted smoothly without resistance until the end face of the resin pipe hits the step of the joint body.
Next, in this inserted state, when trying to apply water pressure without compressing and crimping the sleeve with a die, water may leak from between the resin pipe and the compression caulking fitting just by passing water. It could be confirmed.
Subsequently, the sleeve was caulked with a special die having the shape shown in FIGS. 5 to 7 (caulking ridge inner diameter: φ19.4 mm), and the resin pipe and the compression caulking pipe joint were connected.
In this state, short-term water pressure test (23 ℃ × 1.75MPa × 2min) and long-term hydrostatic pressure test (95 ℃ × 1.35MPa × 1000 hours) were conducted. It was.
Further, the resin pipe minimum inner diameter of the ring-shaped sealing material contact portion reduced in diameter by compression caulking was φ14.70 mm, and the compression ratio of the ring-shaped sealing material was 5.8%.

(Comparative Example 1)
A compression crimped pipe joint having the shape shown in FIGS. 1 and 2 having the following dimensions is prepared, and the produced compression crimped pipe joint and resin pipe (metal reinforced polyethylene pipe manufactured by Sekisui Chemical Co., Ltd., Super Ethromex) φ16 (outer diameter: φ20.1 mm, wall thickness 2.25 mm) was connected as follows.
Nozzle section maximum outer diameter (diameter of upper edge of side wall of seal material fitting groove): φ15.22mm
Diameter of bottom part of sealing material fitting groove: φ11.4mm
Sleeve inner diameter: φ20.3mm
Sleeve wall thickness: 0.5mm
Height from the bottom of the seal material fitting groove of the ring-shaped seal material to the highest position: 2.30mm
Note that the compression caulking pipe joint produced as described above has a sleeve inner diameter larger than the outer diameter of the resin pipe and a nozzle portion maximum outer diameter smaller than the inner diameter of the resin pipe. However, the upper end of the ring-shaped sealing material protrudes from the sealing material fitting groove, and the outer diameter of the highest position portion from the bottom of the sealing material fitting groove of the ring-shaped sealing material is larger than the inner diameter of the resin tube.
And the said resin pipe | tube was inserted between the sleeve and nozzle part of the compression caulking pipe joint produced as mentioned above.
A short-term water pressure test (23 ° C. × 1.75 MPa × 2 minutes) was performed in this inserted state without performing compression caulking of the sleeve with a die, and no abnormality was found.
Subsequently, the sleeve was caulked with a special die having the shape shown in FIGS. 5 to 7 (caulking ridge inner diameter: φ19.4 mm), and the resin pipe and the compression caulking pipe joint were connected.
In this state, a long-term hydrostatic pressure test (95 ° C. × 1.35 MPa × 1000 hours) was carried out. After about 250 hours, water leaked from between the pipe and the joint.

(Comparative Example 2)
A compression crimped pipe joint having the shape shown in FIGS. 1 and 2 having the following dimensions is prepared, and the produced compression crimped pipe joint and resin pipe (metal reinforced polyethylene pipe manufactured by Sekisui Chemical Co., Ltd., Super Ethromex) A caulking connection of φ16 (outer diameter: φ20.1 mm, wall thickness 2.25 mm) was made as follows.
Nozzle section maximum outer diameter (diameter of upper edge of side wall of seal material fitting groove): φ15.22mm
Diameter of bottom part of sealing material fitting groove: φ11.4mm
Sleeve inner diameter: φ20.3mm
Sleeve wall thickness: 0.5mm
Height from the bottom of the seal material fitting groove of the ring-shaped seal material to the highest position: 2.30mm
Note that the compression caulking pipe joint produced as described above has a sleeve inner diameter larger than the outer diameter of the resin pipe and a nozzle portion maximum outer diameter smaller than the inner diameter of the resin pipe. However, the upper end of the ring-shaped sealing material protrudes from the sealing material fitting groove, and the outer diameter of the highest position portion from the bottom of the sealing material fitting groove of the ring-shaped sealing material is larger than the inner diameter of the resin tube.
And the said resin pipe | tube was inserted between the sleeve and nozzle part of the compression caulking pipe joint produced as mentioned above.
A short-term water pressure test (23 ° C. × 1.75 MPa × 2 minutes) was performed in this inserted state without performing compression caulking of the sleeve with a die, and no abnormality was found.
Subsequently, the sleeve was caulked with a special die having a shape shown in FIGS. 5 to 7 (caulking ridge inner diameter: φ18.8 mm), and the resin pipe and the compression caulking pipe joint were connected.
In this state, when a long-term hydrostatic pressure test (95 ° C. × 1.35 MPa × 1000 hours) was performed, water leaked from between the resin pipe and the joint after about 550 hours. When the joint after leakage was halved and the inside was checked, the ring-shaped sealing material was damaged.
At this time, the minimum inner diameter of the resin tube at the contact portion of the ring-shaped sealing material reduced in diameter by compression caulking was φ12.97 mm, and the compression rate of the ring-shaped sealing material was 67%.

(Comparative Example 3)
A compression crimped pipe joint having the shape shown in FIGS. 1 and 2 having the following dimensions is prepared, and the produced compression crimped pipe joint and resin pipe (metal reinforced polyethylene pipe manufactured by Sekisui Chemical Co., Ltd., Super Ethromex) A caulking connection of φ16 (outer diameter: φ20.1 mm, wall thickness 2.25 mm) was made as follows.
Maximum outer diameter of nozzle: φ15.22mm
Diameter of bottom part of sealing material fitting groove: φ10.57mm
Sleeve inner diameter: φ20.25mm
Sleeve thickness: 0.45mm
Height from the bottom of the seal material fitting groove of the ring-shaped seal material to the highest position: 2.20mm
Note that the compression caulking pipe joint produced as described above has a sleeve inner diameter larger than the outer diameter of the resin pipe and a nozzle portion maximum outer diameter smaller than the inner diameter of the resin pipe. Further, the upper end of the ring-shaped sealing material does not protrude from the sealing material fitting groove.
And the said resin pipe | tube was inserted between the sleeve and nozzle part of the compression caulking pipe joint produced as mentioned above.
Next, in this inserted state, when trying to apply water pressure without compressing and crimping the sleeve with a die, water may leak from between the resin pipe and the compression caulking fitting just by passing water. It could be confirmed.
Subsequently, the sleeve was caulked with a special die having a shape shown in FIGS. 5 to 7 (caulking ridge inner diameter: φ20.1 mm), and the resin pipe and the compression caulking pipe joint were connected.
In this state, when a short-term water pressure test (23 ° C. × 1.75 MPa × 2 minutes) was performed, water leaked from between the resin pipe and the compression-caulking pipe joint.
At this time, the resin tube minimum inner diameter of the ring-shaped sealing material contact portion reduced in diameter by compression caulking was φ15.4 mm, and the compression rate of the ring-shaped sealing material was −10%.

DESCRIPTION OF SYMBOLS 1 Compression caulking pipe joint 2 Joint main body 23 Nozzle part 23a Sealing material fitting groove 24 Ring-shaped sealing material 3 Sleeve 34 Linear caulking part 5 Caulking die 5a Split die P Resin pipe (metal reinforced polyethylene pipe)

Claims (3)

By inserting the end of the resin pipe connected between the nozzle part provided at one end of the pipe joint and the sleeve arranged so as to surround the nozzle part, and caulking with a dedicated caulking die A compression caulking pipe joint in which the end of the resin pipe is sandwiched between the sleeve and the nozzle part in a watertight manner,
The nozzle portion has a ring-shaped sealing material fitting groove in a portion corresponding to the caulking position of the sleeve,
The seal material fitting groove is fitted with a ring-shaped seal material whose maximum height from the bottom of the seal material fitting groove is lower than the upper ends of both side walls of the seal material fitting groove. Compression caulking pipe fittings.   The compression crimping fitting according to claim 1, wherein the ring-shaped sealing material has a cross-sectional shape that is compressed at a compression rate of 5 to 65% in a normal caulking state with a dedicated caulking die.   Two semi-arc-shaped linear caulking portions to be paired do not exist in the same plane, and the caulking positions of the sleeves are formed so that both ends of the arcs of both linear caulking portions overlap three-dimensionally. The connection structure of the resin pipe and the compression caulking pipe joint according to claim 1 or 2, wherein the resin pipe and the compression caulking pipe joint are connected.

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