JP2007333127A - Connection structure between pipe and joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure between a pipe and a joint to avoid such a situation that a cap nut ceases to function or is broken by being overtightened while providing a screw-in joint for a composite pipe to achieve the prevention of pipe fall-out. <P>SOLUTION: This connection structure is equipped with a joint body 5 and the cap nut 9. The joint body 5 comprises screw parts 6 and 7 at one end and an intermediate part thereof, respectively, and comprises a tube 8 extended to the inside of the screw part 6 of the intermediate part and inserted into the pipe 1. The cap nut 9 comprises a threaded engagement part 10 with a screw formed thereon, the screw engaged with the screw part 6 at the intermediate part of the joint body 5, an annular part 11 extended therefrom, and a pipe insertion hole 12 with the periphery of the pipe 1 contacting therewith. This connection structure comprises a presser ring 20 for reducing the diameter of a split ring 13 with the pipe 1 inserted therethrough, thereby giving a pressing force F capable of deforming the pipe 1 to the pipe 1, while having a recessed groove 30 on the peripheral surface of the tube 8, the recessed groove 30 capable of holding deformed portions 1a and 1b on the pipe 1 by the pressing force F. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a connection structure between a pipe and a joint.

  At the time of plumbing for hot water supply and hot water supply, draw the water supply main pipe and the hot water supply main pipe from the hot water supply equipment indoors, connect these water supply main pipe and hot water supply main pipe to the water supply pipe header and the hot water supply pipe header, respectively. As water supply pipes and hot water supply pipes connecting these headers to, for example, water stopcocks located upstream of the hot and cold water mixing taps in the bathroom, they are resistant to heat, such as crosslinked polyethylene or crosslinked polybutene, are not easily deformed, and rust. It is used by inserting a resin pipe having excellent durability into the bellows-like sheath tube, so that in the case of water leakage etc., the sheath tube is left as it is. There is convenience in that the resin pipe can be taken out from the inside of the sheath tube and replaced by simply releasing the connection at both ends.

  And what is shown in FIG. 4 as what is called a screw-in type joint for resin pipes connected with a pipe by fastening a cap nut to a joint main body. The connection procedure of the resin pipe P is as follows.

(1) As shown in FIG. 4A, at the construction site, the pipe P is inserted into the joint body 71 to which the split ring and the cap nut 73 are assembled at the time of factory shipment.
(2) At this time, the pipe P is inserted until the indicator button 72 protrudes (see FIG. 4B).
(3) Subsequently, using a tool, the cap nut 73 is turned in the direction indicated by the arrow A to tighten the cap nut 73 until it stops (see FIG. 4C).
(4) After tightening, a confirmation mark 74 is drawn on the cap nut 73 and the joint body 71 (see FIG. 4D).

  Incidentally, in recent years, in addition to the joint to which the resin pipe is connected, for example, a three-layer structure in which an aluminum metal layer is sandwiched between synthetic resin layers made of a synthetic resin material such as crosslinked polyethylene or polybutene and a metal material such as aluminum. The following patent documents 1 to 4 propose joints to which composite pipes having a structure are connected.

JP 2005-325904 A JP 2004-125016 A Japanese Patent Laid-Open No. 2004-360791 JP 2004-324858 A

  However, the joint described in Patent Document 1 is a so-called caulking, in which a composite pipe is inserted between a connection portion of a joint body and a compression ring, the compression ring is compressed and deformed, and the composite pipe is firmly bitten into the connection portion. In order to compress and deform the compression ring, a dedicated compression jig is required. The joint described in Patent Document 2 is also a caulking joint.

  Further, the joint described in Patent Document 3 is a so-called one-touch joint that can be easily connected by simply inserting the composite pipe into the joint body, and the retaining member having a claw that is a biting portion is used as the composite pipe. However, there are drawbacks in that the composite pipe is damaged and the composite pipe is more easily removed from the joint body than the caulking joint. The joint described in Patent Document 4 is also a one-touch joint.

  On the other hand, in the screw-in type joint for resin pipes shown in FIG. 4, the cap nut 73 is formed of a metal material. Therefore, when the cap nut 73 is tightened with a tool, it is necessary to tighten the cap nut 73 to the end. Therefore, there is a risk that the cap nut 73 will not function or is damaged due to overtightening. Even if the composite pipe is connected to the joint having such a configuration in place of the resin pipe, It can be easily estimated that there may be a situation such as breakage of the cap nut 73 due to overtightening of the cap nut 73. In addition, in a screw-in type joint for resin pipes, when construction is performed at a place where the joint needs to be periodically removed, torque management of the cap nut is necessary after construction.

  The present invention is able to avoid a situation in which a cap nut is tightened too much and the cap nut becomes non-functional or breaks, and a pipe and joint capable of obtaining a screw-in type composite pipe joint that can prevent pipe disconnection It is an object to provide a connection structure.

  In order to achieve the above object, the pipe-to-joint connection structure according to the present invention includes a pipe inserted into a joint body in which a split ring and a cap nut are assembled in advance, and the cap nut is tightened into the joint body. In a pipe-to-joint connection structure configured to connect a joint, the joint has a threaded portion at one end and an intermediate portion, and a tubular portion that extends inside the threaded portion of the intermediate portion and is inserted into the pipe A main body, a threaded portion formed with a screw threaded to the threaded portion of the intermediate portion of the joint body, an annular portion extending from the threaded portion, and a pipe insertion hole portion with which the outer periphery of the pipe abuts A cap nut, and is fitted in advance from the side of the threaded portion of the cap nut to the inside of the cap nut so as to be positioned between the split ring and the pipe insertion hole on the inner peripheral surface of the annular portion. By tightening the cap nut on the joint body, it moves to the joint body side together with the cap nut, and in the middle of the movement, the split ring through which the pipe is inserted is reduced in diameter, and thereby a pressing force capable of deforming the pipe is applied. In addition to having a pressing ring for applying to the pipe, a concave groove capable of holding a deformed portion of the pipe by the pressing force is provided on the outer peripheral surface of the cylindrical portion (Claim 1). .

  In this case, during the tightening operation in which the cap nut is tightened to the joint body, the holding ring is configured to reduce the diameter of the split ring through which the pipe is inserted and to deform the pipe by the stress generated in the split ring. When the tightening operation is completed, the cap nut is detached from the threaded portion of the intermediate portion of the joint body, so that the presser ring is released from the split ring to release the stress, and the cap nut and the presser ring It is preferable that the cap nut is in an idle state in a state where the holding ring is held between the annular portion of the cap nut and the split ring without moving.

  In this invention, the joint body has a cylindrical portion inserted into the pipe, while a retaining ring is fitted in advance from the threaded portion side of the cap nut to the inner side of the cap nut, and the inner surface of the annular portion of the cap nut is It is arranged on one end side of the split ring. Therefore, by tightening the cap nut on the joint body, the press ring moves to the joint main body side together with the cap nut, and during the movement, the split ring through which the pipe is inserted can be reduced in diameter by the press ring. And a pipe deform | transforms with the pressing force from the pressing ring which narrows a split ring, and the deformed location of a pipe is hold | maintained (accommodated) in the concave groove provided in the outer peripheral surface of the said cylinder part. That is, the pipe deformed by the pressing force is locked (scrambled) in the concave groove of the cylindrical portion that is in sliding contact with the inner peripheral surface of the pipe, thereby preventing the pipe from coming off.

And in this invention, when the tightening operation of the cap nut is completed, the split ring is detached from the presser ring and the presser ring is split from the presser ring by removing the screwed portion of the cap nut from the threaded portion of the intermediate portion of the joint body. It is configured to release the stress for pipe deformation that has been applied, and the cap nut and the press ring do not move, and the press ring is held between the annular portion and the split ring of the cap nut, When the cap nut is configured to be idle, the following effects are obtained. That is, the purpose of tightening the cap nut to move the presser ring toward the joint body side is to reduce the diameter of the split ring by the annular portion of the cap nut pressing the split ring through the presser ring. This is to generate a stress for deforming the pipe. When the purpose is achieved, the cap nut is released from the tightening operation and becomes idle. That is, after the cap nut is tightened, the cap nut is released from the screw connection with the joint main body and rotates idle. Therefore, overtightening of the cap nut can be avoided.
The presser ring, split ring, and joint body need to be formed of a metal material. However, the cap nut does not rotate from the joint body after the pipe is deformed, and therefore does not always perform a tightening operation with a load. In other words, since the present invention adopts a configuration that releases the stress for pipe deformation when tightening is completed, the cap nut such as that used in a conventional screw-type resin pipe joint is only being tightened. Although the stress concentration state is always present even after tightening, the cap nut used in the present invention exists only when the pipe is deformed. Therefore, the cap nut of the present invention formed separately from the holding ring can be made of a synthetic resin material instead of a metal such as polycarbonate instead of a metal material. That is, for example, polycarbonate is a thermoplastic resin that has excellent heat resistance and aging resistance, has toughness and can withstand impacts, and is a synthetic resin material that replaces metal. Household building materials, automobile parts, and electrical insulation materials , Photographs, films, other films, sheets and so on. In addition, thermoplastic resins such as polycarbonate have good transparency, elegant gloss, high-quality feeling, low molding shrinkage, and little change over time during long-term use. ing. For example, when a cap nut used in the present invention is molded using polycarbonate as a material, the manufacturing cost can be reduced as compared with the case where the cap nut is molded using a metal material, and a bag made of polycarbonate. Since the nut is transparent, it is easy to check the insertion state of the pipe at a glance, and even when there is an abnormality in the position of the split ring or holding ring or during the operation of tightening the cap nut on the joint body, There is an effect that the operator can immediately confirm visually.

  Also, with conventional screw-in joints for resin pipes, when installed in places where the joints need to be removed periodically, torque management of the cap nut is required after installation. Is not required and the workability can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited thereby.

1 to 3 show an embodiment of the present invention. FIG. 1 shows the state when the tightening operation of the cap nut is completed, and shows a state in which the pipe and the joint are connected and can be used. FIG. 2 shows a connection procedure between a pipe and a joint, and FIG. 3 shows an example of a water / hot water supply piping system to which the present invention is applied.
1 to 3, reference numeral 1 denotes a composite pipe having, for example, a three-layer structure, and a metal layer such as aluminum between synthetic resin layers 2 and 3 made of a synthetic resin material such as crosslinked polyethylene or polybutene and a metal material such as aluminum. 4 is pinched. Reference numeral 5 denotes a metal joint body, which has male screw portions 6 and 7 on the downstream end (one end) and upstream side (intermediate portion), respectively, and has a cylindrical portion 8 extending on the upstream side inside the male screw portion 6. is doing. The cylindrical portion 8 is inserted into the composite pipe 1 at the time of construction. A cap nut 9 is made of polycarbonate having excellent impact resistance, scratch resistance, heat resistance, water resistance, and transparency. The cap nut 9 having good transparency made of polycarbonate has a threaded portion 10 that is screwed into the male threaded portion 6 of the joint body 5, an annular portion 11 that extends from the threaded portion 10, and an outer periphery a of the pipe 1. It has a pipe insertion hole 12 in contact therewith. Reference numeral 20 denotes a pressing ring for applying a pressing force (stress) F that can deform the composite pipe 1 to the pipe 1, on the upstream side (one end side) of the split ring 13 on the flat inner peripheral surface 11 a of the annular portion 11. Are fitted in advance from the side of the threaded portion 7 of the cap nut 9 to the inside of the cap nut 9.

  The split ring 13 is made of metal and includes a large-diameter head portion 14 and a small-diameter leg portion 15, and the diameter can be reduced or increased. The head 14 is thicker than the legs 15. The inner peripheral surface m of the head 14 is provided with a plurality of ring strip protrusions 16 around the shaft core in a state having a predetermined interval in the shaft core direction. The protruding strips 16 have, for example, the same shape, for example, have a substantially rectangular cross section with the axial direction as the longitudinal direction. As shown in FIG. 2A, the split ring 13 is inserted through the composite pipe 1 in advance in contact with the outer periphery a of the composite pipe 1 via the protruding strip 16. Moreover, the upstream side of the outer peripheral surface n (refer FIG. 1) of the head 14 is formed in the taper shape. The tapered surface 17 is a surface formed so as to become wider toward the downstream side. Further, the downstream side of the outer peripheral surface n of the head 14 is composed of a surface 18 formed so as to be parallel to the flat inner peripheral surface 11 a of the annular portion 11 of the cap nut 9. Then, as shown in FIG. 2 (A), in the initial stage of construction (before the cap nut is tightened), the composite pipe 1 with the split ring 13 inserted is inserted to the contact surface 19 of the joint body 5 and split. The ring 13 is set so that the legs 15 are pressed until they abut against the contact surface 19.

  The pressing ring 20 is made of metal, has a substantially d-shaped vertical cross section, and is formed in a tapered shape on the upstream side of the inner peripheral surface n ′ of the thick head portion 24. The tapered surface 25 is a surface formed so that the width becomes narrower toward the downstream side. Then, as shown in FIG. 2A, in the initial stage of construction, the pressing ring 20 has the leg 24 a on the upstream side of the split ring 13 in a state where the tapered surface 25 is in contact with the tapered surface 17 of the split ring 13. Arranged through. That is, the holding ring 20 is located between the split ring 13 and the pipe insertion hole 12 on the inner peripheral surface 11 a of the annular portion 11.

  Reference numeral 30 denotes a ring-shaped concave groove, and a plurality of grooves are provided on the outer peripheral surface 8a of the cylindrical portion 8 with a predetermined interval along the axial direction. In this embodiment, two concave grooves 30 are provided, and as shown in FIG. 2A, two protrusion pieces 16 provided at positions corresponding to the concave grooves 30 in the initial stage of construction are also provided. Although the number is shown, the number is not limited. In short, the position corresponding to the protruding strip 16 in a state where the tapered surface 25 is in contact with the tapered surface 17 of the split ring 13 in the initial stage of construction. It suffices if the groove 30 is provided.

  In addition, a plurality of annular grooves 31 for the O-ring 33 are provided on the outer peripheral surface 8a of the cylindrical portion 8 with a predetermined interval along the axial direction. The position of the annular groove 31 is on the upstream side of the recessed groove 30, and is provided, for example, at a position facing the pipe insertion hole 12.

  The water supply / hot water supply piping system will be briefly described below. In FIG. 3, 41 is a hot water supply pipe, 42 is a water supply pipe, and the hot water supply pipe 41 includes a hot water supply pipe header 44 provided on the downstream side of the hot water supply main pipe 43 drawn indoors, for example, a washroom A stop cock main body 47 of a hot water stop cock 46 located upstream of the hot water mixing stopper 45 is connected. The water supply pipe 42 connects a water supply pipe header 49 provided on the downstream side of the water supply main pipe 48 drawn indoors and the water stopcock body 51 of the water stopcock 50. 52 is a hot water supply facility. The water stop cock 50 and the hot water stop cock 46 have the same structure. The hot water supply pipe 41 and the water supply pipe 42 are those in which the composite pipe 1 is guided and protected by a sheath pipe 54 on the piping path. Both the 41 and 42 are appropriately fixed by a fixing means 55 such as a band. The position is fixed. The upstream end 53 a of the water composite pipe 1 is connected to the header 49 by a connecting member 56. Similarly, the upstream end 53 b of the hot water composite pipe 1 is connected to the header 44 by a connecting member 58. Reference numeral 59 denotes a flexible hot water introduction pipe which connects the hot water mixing tap 45 and the stop cock 46. Reference numeral 60 denotes a flexible water introduction pipe that connects the hot-water mixing plug 45 and the water stop cock 50. The male threaded portion 6 of the joint body 5 is connected to, for example, a female threaded portion (not shown) provided at the upstream end of the water stopcock main body 51 and provided at the upstream end of the waterstop main body 47, for example. It is connected to a female screw portion (not shown).

Thus, as shown in FIG. 2A, in the initial stage of construction, the presser ring 20 of the split ring 13 is in a state where the tapered surface 25 of the presser ring 20 is in contact with the tapered surface 17 of the split ring 13. Arranged upstream.
Subsequently, as shown in FIG. 2 (B), by tightening a transparent cap nut 9 made of polycarbonate to the joint body 5, the press ring 20 moves to the joint body side together with the cap nut 9. The split ring 13 through which 1 is inserted is reduced in diameter by the pressing force F by the pressing ring 20, whereby the pipe 1 is deformed to the concave groove 30 side. As a result, as shown in FIGS. 1 and 2C, the deformed portions 1 a and 1 b of the pipe 1 are held (accommodated) in the concave groove 30 by the pressing force F. That is, the deformed portions 1a and 1b of the composite pipe 1 are locked (hooked) in the ring-shaped concave groove 30 formed in the cylindrical portion 8 that is in sliding contact with the pipe inner peripheral surface b. The composite pipe 1 can be prevented from coming off.
After the composite pipe 1 is deformed, the cap nut 9 is released from the tightening operation and becomes idle. That is, after the cap nut 9 is tightened, the screwed portion 10 of the cap nut 9 is detached from the screw portion 7 of the joint body 5, and the cap nut 9 and the presser ring 20 do not move, and the presser ring 20 is connected to the cap nut 9. The cap nut 9 idles around the joint body 5 while being held between the annular portion 11 and the split ring 13. Therefore, overtightening of the cap nut 9 can be avoided.

This embodiment has the following effects.
(1) By tightening the cap nut 9, the split ring 13 is narrowed, thereby deforming the composite pipe 1, and the deformed portions 1 a and 1 b of the composite pipe 1 are caught in the concave groove 31, and are prevented from coming off. It becomes.
(2) A structure that avoids overtightening of the cap nut 9 is adopted. That is, when the cap nut 9 is tightened, the screw of the cap nut 9 is finally removed from the screw of the joint body 5 and the cap nut 9 is idled. When the tightening operation is completed, the split ring 13 is removed from the holding ring 20. Since the stress F to the split ring 13 can be released by detaching, it is possible to avoid breakage of the cap nut 9 due to overtightening of the cap nut 9.
(3) The cap nut 9 exists only when the stress concentration state deforms the composite pipe 1. Therefore, the cap nut 9 formed separately from the holding ring 20 is not a metal material, but is a lower cost than a cap nut made of a metal material, and is a synthetic resin that has a property equivalent to that of metal and replaces metal. It can be made of polycarbonate.
(4) In addition, since the cap nut 9 made of polycarbonate is transparent, it is easy to check the insertion state of the composite pipe 1 at a glance, and the split ring 13 and the presser are pressed during the operation of tightening the cap nut 9 to the joint body 5. Even when the position of the ring 20 is confirmed or when both the rings 13 and 20 are abnormal, the operator can immediately confirm visually.

It is composition explanatory drawing which shows the time of fastening operation | movement of the cap nut in one embodiment of this invention completion. (A) is composition explanatory drawing which shows the state before the fastening operation | movement of the cap nut of the connection procedure of the pipe and joint in the said embodiment. (B) is a configuration explanatory view showing a state during the tightening operation of the cap nut in the connection procedure of the pipe and the joint in the embodiment. (C) is a configuration explanatory view showing a state after the tightening operation of the cap nut in the connection procedure of the pipe and the joint in the embodiment. It is a figure which shows an example of the water supply and hot water supply piping system in which the said embodiment is used. It is a figure which shows the connection procedure of the conventional pipe and a screwed type coupling.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite pipe 1a, 1b Pipe deformed part 5 Joint main body 6,7 Threaded portion of joint main body 8 Tube portion 9 Cap nut 10 Screwed portion of cap nut 11 Annular portion 11a Inner circumferential surface of annular portion 12 Pipe insertion hole Part 13 Split ring 20 Presser ring 30 Groove F Pressing force

Claims (3)

In the connection structure of a pipe and a joint configured to connect the pipe and the joint by inserting the pipe into the joint body in which the split ring and the cap nut are assembled in advance, and tightening the cap nut on the joint body,
A joint body having a threaded portion at one end and an intermediate portion, and a tubular portion extending inside the threaded portion of the intermediate portion and inserted into the pipe;
A cap nut having a threaded portion formed with a screw threadedly engaged with the threaded portion of the intermediate portion of the joint body, an annular portion extending from the threaded portion, and a pipe insertion hole portion with which the outer periphery of the pipe abuts. With
Furthermore, it is fitted in advance from the threaded portion side of the cap nut to the inner side of the cap nut so as to be positioned between the split ring and the pipe insertion hole portion on the inner peripheral surface of the annular portion, and the cap nut is attached to the joint body. To move to the joint body side together with the cap nut by tightening, in order to reduce the diameter of the split ring through which the pipe is inserted, and thereby apply a pressing force that can deform the pipe to the pipe With a holding ring of
A connection structure between a pipe and a joint, wherein a concave groove capable of holding a deformed portion of the pipe by the pressing force is provided on an outer peripheral surface of the cylindrical portion.   During the tightening operation in which the cap nut is tightened to the joint body, the holding ring is configured to reduce the diameter of the split ring through which the pipe is inserted and to deform the pipe by the stress generated in the split ring. When the operation is completed, the cap nut is disengaged from the threaded portion of the intermediate portion of the joint body, so that the press ring is released from the split ring to release the stress, and the cap nut and the press ring move. The pipe-joint connection structure according to claim 1, wherein the cap nut is in an idle state in a state in which the presser ring is held between the annular portion and the split ring of the cap nut. The cap nut is made of a thermoplastic synthetic resin material that is excellent in heat resistance and aging resistance such as polycarbonate, has toughness and can withstand impact, and has transparency, and the pipe is crosslinked. The pipe and joint according to claim 1 or 2, which is a composite pipe having at least a three-layer structure in which a metal layer made of a metal material such as aluminum is sandwiched between synthetic resin layers made of a synthetic resin material such as polyethylene or polybutene. Connection structure.

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