JP2014109296A - Pipe joint structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint structure which eliminates problems that the improvement of piping work efficiency is hindered since fastening work cannot be executed without using an electric working tool, the number of part items is large, parts of complicated shapes are necessary, much time and labor are required at assembling, and so forth.SOLUTION: The pipe joint structure comprises a joint main body 1 having a male thread 2 and a box nut 3 screwed to the male thread 2 of the joint main body 1, and connects resin pipes 4. The joint main body 1 has a compression deformation sleeve 7 which has an internal insertion cylinder part 5 inserted into an end 4A of the resin pipe 4, is accommodated in an internal accommodation space 10 of the box nut 3, and has a recessed peripheral groove 9 at an external peripheral face 8, and in which recessed peripheral groove bottom thin-wall parts 13 are elastically deformed to radial inside directions by receiving compression forces F in axial directions from the joint main body 1 and the box nut 3 when the box nut 3 and the male thread 2 of the joint main body 1 are screwed to each other, and bite into the end 4A of the resin pipe 4 inserted into the internal insertion cylinder part 5 from the side of an external peripheral face 14, thus providing retention.

Description

  The present invention relates to a pipe joint structure.

  Conventionally, a pipe joint has been proposed in which a resin pipe made of PE, PP, PEX (crosslinked polyethylene), or the like is tightened and connected by reducing the diameter of a C-type tightening ring (see Patent Document 1).

JP 2009-168167 A

  However, the conventional pipe joint is provided with a substantially tangential bolt member having a worm wheel at one end and a nut screwed to the C-type clamping ring. It has been configured to reduce the diameter of the tightening ring by rotationally driving, screwing and tightening the nut and bolt member. That is, there is a drawback in that an electric work tool is required during the tightening operation, which hinders an increase in piping work efficiency. In addition, there are disadvantages that the number of parts is large, complicated shaped parts are required, and it takes time and effort during assembly.

  Therefore, the present invention cannot be tightened unless an electric work tool is used, which hinders the efficiency of piping work, and has a large number of parts and requires complicatedly shaped parts. An object of the present invention is to provide a pipe joint structure for avoiding the above-mentioned problems such as taking time and effort.

  A pipe joint structure according to the present invention comprises a joint body with a male thread and a cap nut screwed to the male thread of the joint body, wherein the joint body has a joint structure for connecting resin pipes. And an insertion tube portion inserted into the end portion of the resin pipe, and is accommodated in the internal storage space of the cap nut, and has a concave circumferential groove on the outer peripheral surface, and the cap nut and the joint body When the male screw is screwed, the axially compressive force is received from the joint body and the cap nut, and the concave circumferential groove bottom thin wall portion is plastically deformed radially inward and inserted into the insertion tube portion. A compression deformation sleeve is provided at the end portion of the resin pipe that bites in from the outer peripheral surface side to prevent the resin tube from being pulled out.

In addition, when the connection is completed, the inner space of the cap nut has a push spring that applies an elastic force in the axial direction to the outer end of the compression deformation sleeve.
Moreover, the said insertion cylinder part has a seal groove in an outer peripheral surface, and mounts the annular | circular shaped sealing material in this seal groove.

  According to the pipe joint structure of the present invention, by simply screwing the cap nut, pulling out of the resin pipe can be strongly prevented, and connection (piping) exhibiting hermeticity can be made quickly and easily. It is not necessary to perform a tightening operation using an electric power tool, and the work efficiency can be improved. Moreover, it is compact, has a small number of parts, has a simple part shape, and can be easily assembled.

It is the cross-sectional front view which showed the state before the pipe connection of one Embodiment of this invention. It is the cross-sectional front view which showed the connection completion state. It is a sectional front view showing a sleeve for compression deformation, (A) is a sectional front view in a free state, (B) is an enlarged sectional front view of an essential part in a free state, and (C) is an enlarged sectional front view of an essential part in a connected state. FIG. It is the cross-sectional front view which showed the state before the pipe connection of other embodiment of this invention. It is the cross-sectional front view which showed the connection completion state.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
As shown in FIG. 1, the pipe joint structure of the present invention includes a joint body 1 with a male thread and a cap nut 3 that is screwed onto the male thread 2 of the joint body 1, and a pipe joint 6 and a resin pipe 4. It is the pipe joint structure comprised so that may be connected.
The joint body 1 has an insertion tube portion 5, the insertion tube portion 5 is inserted into the end portion 4 </ b> A of the resin tube 4, and the cap nut 3 is screwed and tightened to the male screw 2 to tighten the resin tube 4. And the pipe joint 6 are connected.
In the pipe connection completion state, fluid such as air or water flows inside the resin pipe 4 and the pipe joint 6.

The pipe joint structure of the present invention has a compression deformation sleeve 7.
The compression deformation sleeve 7 is made of metal such as aluminum or copper, or plastic, and has two U-shaped concave grooves 9 and 9 on the outer peripheral surface 8 (see FIG. 3A). . The concave circumferential groove 9 is provided so that the bottom thin wall portion 13 is formed thinly and radially inward. The compression deformation sleeve 7 is stored in the internal storage space 10 of the cap nut 3 (see FIGS. 1 and 2).

  The joint body 1 has a contact receiving surface 17 having a diameter larger than that of the sleeve 7. Moreover, the insertion cylinder part 5 has the multi-ring-shaped small protrusion 19 on the outer peripheral surface.

  When the female sleeve 7 of the cap nut 3 and the male screw 2 of the joint main body 1 are screwed together, the compression deformation sleeve 7 is moved from the free state of FIG. 3 (B) to the joint main body as shown in FIG. 3 (C). 1 (the contact receiving surface 17 thereof) and the compression nut (clamping force) F in the axial direction from the cap nut 3, and the concave circumferential groove (while gradually reducing the width dimension W of the U-shaped concave circumferential groove 9) The bottom thin wall portion 13 is plastically deformed radially inward and bites into the end portion 4A of the resin tube 4 inserted into the insertion tube portion 5 from the outer peripheral surface 14 side to prevent it from being removed.

  The compression deformation sleeve 7 causes the concave circumferential groove bottom thin wall portion 13 to bite into the resin tube 4, exhibits a strong pull-out resistance, and prevents the resin tube 4 from being pulled out. Further, the compression deformation sleeve 7 is sealed by pressing the end portion 4A of the resin tube 4 from the outer peripheral surface 14 side when it bites in by a radial tightening force. As shown in FIGS. 2 and 3C, the resin pipe 4 is formed with small protrusions 25 and 25 by the inner peripheral surface being plastically deformed in the radial inward direction by the radial tightening force. Yes. The small protrusions 25 and 25 are in pressure contact with the outer peripheral surface of the insertion tube portion 5 while being elastically deformed in a connected state. At this time, the small ridges 19 dig into the bulged small ridges 25, 25 from the radial inner side so that the space between the resin tube 4 and the insertion tube 5 is sealed and pulled out. Prevent slipping in the direction. The concave circumferential groove 9 may have a width dimension W of zero when the side surfaces 15 and 15 are pressed against each other during plastic deformation (not shown).

As shown in FIG. 2 and FIG. 3 (C), when the connection is completed, a push spring 12 that applies an elastic force in the axial direction to the outer end portion 7A of the compression deformation sleeve 7 is provided inside the cap nut 3. It is in the storage space 10.
In the illustrated example, the push spring 12 is a coil spring. Even if a stress relaxation phenomenon due to creep occurs after the connection is completed by continuously pressing the elastic force in the axial direction to the compression deformation sleeve 7 by the pressing spring 12, the compression deformation sleeve 7 is made of resin. Following the small deformation of the tube 4, the concave circumferential groove bottom thin wall portion 13 is deformed radially inward. In this way, even after the connection is completed, even if the resin tube 4 is slightly deformed after a certain period of time, the pull-out force of the resin tube 4 is maintained and the sealing performance is maintained.

Further, a hard cover member 16 made of hard metal such as stainless steel (or hard plastic) is attached to the compression deformation sleeve 7 in an outer fitting shape.
The hard cover member 16 prevents electric corrosion of the cap nut 3 and the compression deformation sleeve 7, and when the cap nut 3 is screwed onto the male screw 2, it can be used as a work tool even if the rotational torque to the cap nut 3 is small. Can be rotated. In addition, sliding on the inner peripheral surface of the cap nut 3 prevents the compression deformation sleeve 7 from rotating.
With this configuration, the compression deformation sleeve 7 can be prevented from being corroded by electric corrosion, and friction with the cap nut 3 can be reduced. Further, it is possible to prevent the cap nut 3 and the compression deformation sleeve 7 from rotating together, and to prevent the resin tube 4 from being twisted.

Next, another embodiment of the present invention will be described.
4 and 5, the insertion tube portion 5 has a seal groove 22 on the outer peripheral surface 11, and an annular seal member 23 is attached to the seal groove 22. Other configurations are the same as those of the above-described embodiment.
The sealing material 23 is compressed and elastically deformed by being compressed by the inner peripheral surface of the resin tube 4 when the resin tube 4 is inserted into the inner tube portion 5. Further, when the compression deformation sleeve 7 receives a compressive force F in the axial direction from the joint main body 1 and the cap nut 3, the inner wall of the resin pipe 4 is deformed when the concave circumferential groove bottom thin wall portion 13 is plastically deformed radially inward. The peripheral surface is further crushed, and the sealing material 23 comes into pressure contact with the resin tube 4. That is, by providing the sealing material 23 in the seal groove 22 of the insertion tube portion 5, the space between the resin tube 4 and the insertion tube portion 5 can be reliably sealed.

The present invention can be modified in design. For example, the hard cover member 16 may be omitted. Further, it is preferable to use a disc spring or a leaf spring as the push spring 12.
In the present invention, the resin pipe 4 includes a pipe made of plastic such as PE, PP or PEX (crosslinked polyethylene), or a composite pipe in which a metal pipe is housed on the inner diameter side of the plastic pipe. And
The number of U-shaped concave circumferential grooves 9 of the compression deformation sleeve 7 can be increased or decreased.

  As described above, the pipe joint structure according to the present invention includes the joint body 1 with the male thread and the cap nut 3 that is screwed onto the male thread 2 of the joint body 1 and connects the resin pipe 4. In the structure, the joint body 1 has an insertion tube portion 5 inserted into the end portion 4A of the resin tube 4 and is housed in the internal storage space 10 of the cap nut 3 and is recessed on the outer peripheral surface 8. When the cap nut 3 and the male screw 2 of the joint body 1 are screwed together, the concave circumferential groove bottom thin wall portion 13 receives the compressive force F in the axial direction from the joint body 1 and the cap nut 3. Since there is a compression deformation sleeve 7 that is plastically deformed radially inward and that bites into the end portion 4A of the resin tube 4 inserted into the insertion tube portion 5 from the outer peripheral surface 14 side, the cap nut 3 The connection (arrangement) that can exert a strong pull-out force against the resin tube 4 and has a sealing performance by simply screwing ) To be carried out quickly and easily. It is not necessary to perform a tightening operation using an electric power tool, and the work efficiency can be improved. Moreover, it is compact, has a small number of parts, has a simple part shape, and can be easily assembled.

  Further, in the connection completion state, the inner housing space 10 of the cap nut 3 has a pressing spring 12 that applies an elastic force in the axial direction to the outer end portion 7A of the compression deformation sleeve 7. Even when the stress relaxation phenomenon due to creep occurs in the tube 4, the compression deformation sleeve 7 plastically deforms in the radial inward direction following the small deformation of the resin tube 4, and the pull-out resistance of the resin tube 4 Can be maintained and the sealing property can be maintained. Therefore, a stable connection state can be maintained over a long period of use.

  Moreover, since the insertion cylinder part 5 has the sealing groove | channel 22 in the outer peripheral surface 11, and the annular | circular shaped sealing material 23 is mounted | worn in the sealing groove | channel 22, between the resin pipe 4 and the insertion cylinder part 5 is ensured. Can be sealed.

DESCRIPTION OF SYMBOLS 1 Joint main body 2 Male screw 3 Cap nut 4 Resin pipe 4A End part 5 Insertion cylinder part 7 Compression sleeve 7A Outer end part 8 Outer peripheral surface 9 Concave groove 10 Internal storage space 11 Outer peripheral surface 12 Push spring 13 Concave groove Bottom thin wall portion 14 outer peripheral surface 22 seal groove 23 annular seal material F compressive force

Claims (3)

In a pipe joint structure comprising a joint body (1) with a male thread and a cap nut (3) screwed to the male thread (2) of the joint body (1) and connecting a resin pipe (4) And
The joint body (1) has an insertion tube portion (5) inserted into the end portion (4A) of the resin pipe (4),
The cap nut is housed in the internal storage space (10) of the nut (3), has a concave groove (9) on the outer peripheral surface (8), and is a male of the cap nut (3) and the joint body (1). When the screw (2) is screwed, the axially compressive force (F) is received from the joint body (1) and the cap nut (3), so that the concave groove bottom thin wall portion (13) is radially inward. A compression deformation sleeve which is plastically deformed and bites into the end portion (4A) of the resin pipe (4) inserted into the insertion tube portion (5) from the outer peripheral surface (14) side to prevent it from being removed. 7) A pipe joint structure characterized by comprising:   When the connection is completed, a compression spring (12) that applies an elastic force in the axial direction to the outer end (7A) of the compression deformation sleeve (7) is connected to the internal storage space of the cap nut (3). The pipe joint structure according to claim 1, which is provided in (10).   The said insertion cylinder part (5) has a sealing groove (22) in an outer peripheral surface (11), and is mounting | wearing with this annular sealing material (23) in this sealing groove (22). Pipe joint structure.

Images