JP2008248909A - Insulating joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating joint capable of insulating, from the joint, a metal layer exposed to a pipe end portion by a simple structure. <P>SOLUTION: This joint 1 having the metal layer 2b formed at the intermediate part and connecting a pipe 2 of at least three-layer structure having resin layers 2a, 2c on their inner and outer side, respectively, comprises: a sleeve 5 formed at one end of a metal body 4; a case member 6 forming a pipe 2 insertion space 7 between the outer peripheral surface of the sleeve 5 and itself and fixed to the sleeve 5 at the bottom end of the insertion space 7; and a fixing means 9 for fixing the pipe 2 inserted into the insertion space 7. The case member 6 comprises a projection 12 projecting to the inside of the insertion space before the bottom end of the insertion space 7 and brought into contact with at least the end surface of the metal layer 2b of the pipe 2 inserted into the insertion space 7. The projection 12 is formed of an insulator, and insulates the metal layer 2b exposed to the pipe end from the metal body 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a joint provided in a water pipe system, and more particularly to an insulating joint suitable for connecting a pipe having a multilayer structure in which a metal layer is provided in an intermediate layer.

  Many joints used in water pipe systems are generally formed of a copper alloy. When a steel pipe made of a different material is connected to the joint, a potential difference is generated between the two and the pipe is corroded. Therefore, conventionally, an insulating layer is provided between the male screw portion and the female screw portion when the female screw formed on the joint and the male screw formed on the steel pipe are connected by screwing, and the pipe interior is formed to insulate the pipe end from the joint. An insulating joint in which a resin pipe end core is inserted is known (for example, Patent Document 1). Such an insulating layer is an effective insulating means for a steel pipe whose surface is covered with metal.

  In recent years, however, the corrosion resistance and durability of water supply pipe systems have been improved, and since it is easier to handle when connecting pipes, a flexible three-layer structure with a metal layer in the middle and resin layers on the inner and outer surfaces is provided. A tube is being used (for example, Patent Document 2). When such a three-layered flexible tube is used, the metal is exposed at the end of the tube, so it is necessary to insulate the tube end portion from the joint.

  However, in the prior art disclosed in Patent Document 1, it is necessary to insert a resin-made pipe end core prepared as a dedicated part for insulating the pipe end from the joint in advance in the joint, resulting in an increase in part cost. Inevitable. Further, since the pipe end core faces the water channel inside the joint, it is necessary to provide the pipe end core in a watertight manner with respect to the joint, and there is a problem that the internal structure of the joint becomes complicated.

JP 2001-159488 A JP 2006-97420 A

  The present invention has been made for the purpose of solving the above-mentioned conventional problems, and provides an insulating joint capable of insulating a pipe end portion with a simple structure.

  In order to achieve the above object, the present invention adopts as a solution means a joint for connecting at least a three-layer structure pipe provided with a metal layer in the middle and provided with a resin layer inside and outside the metal layer. A case member in which a tube insertion space is formed between a cylindrical sleeve portion formed at one end of the body portion and the outer peripheral surface of the sleeve portion, and is fixed to the sleeve portion at the back end portion of the insertion space. And a fixing means for fixing the tube inserted into the insertion space, wherein the case member protrudes inward of the insertion space before the back end and is inserted into at least the metal layer of the tube. It has a protrusion abutting on the end face, and the protrusion is formed of an insulating material. With this configuration, when the tube is inserted and fixed to the far end of the insertion space, the metal layer exposed at the tube end abuts on the protrusion and is completely insulated from the body portion.

  In the insulating joint having the above configuration, it is preferable that the case member and the protrusion are integrally formed of a transparent resin having an insulating action. By configuring the case member with a transparent resin, the insertion position of the tube end can be visually recognized through the case member when the tube is inserted into the insertion space.

  Further, it is more preferable that a position display portion indicating an appropriate insertion position of the tube is provided on the outer periphery of the case member. By providing a position indicator on the outer periphery of the transparent case member, when inserting the tube into the insertion space, the insertion position of the tube end can be seen through the case member, and the tube is inserted to an appropriate insertion position. It becomes possible to confirm whether or not.

  According to the insulating joint according to the present invention, when the tube is inserted and fixed in the insertion space formed between the sleeve portion and the case member, the metal layer exposed at the end of the tube protrudes into the protrusion protruding inside the insertion space. Abut. Since this protrusion is formed of an insulating material, the metal layer of the tube and the metal body can be completely insulated by the protrusion. In addition, since the protrusion has a simple structure in which it is in contact with and insulates the metal layer at the end of the tube, it exhibits an excellent insulating effect at low cost. Such an insulating joint has at least a three-layer structure, and has an insulating structure particularly suitable for insulating and connecting a pipe in which a metal is exposed to an intermediate layer at the end of the pipe.

  Further, when the case member and the protrusion are integrally formed of a transparent resin, there is an advantage that the insertion depth can be visually recognized through the case member when the pipe is inserted, and workability is improved. Furthermore, when providing a position indicator on the outer periphery of the transparent case member, it can be easily grasped whether or not the tube has been inserted to the proper insertion position, so that insufficient insertion can be prevented, and more reliable work can be expected. . And when a pipe | tube is inserted to the back end of insertion space, a favorable insulation state is exhibited by the above-mentioned protrusion, and a pipe | tube is fixed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  1 and 2 are partial sectional views showing an embodiment of an insulating joint 1 according to the present invention. FIG. 1 shows a state before the pipe 2 is connected, and FIG. 2 shows the pipe 2 connected. Indicates the state. This insulating joint 1 has a body part 4 formed of a metal made of a copper alloy such as bronze and a joint structure 3 for connecting a pipe 2 provided at one end of the body part 4. A water channel communicating in the axial direction is formed inside the portion 4. The pipe 2 connected to the insulating joint 1 has a three-layer structure in which the outer side is a resin layer 2a made of a synthetic resin such as polybutene, the middle part is a metal layer 2b made of aluminum or the like, and the inner side is a resin layer 2c. 2b is a flexible tube that exhibits flexibility and can be easily bent when connected. However, the tube 2 is not limited to a three-layer structure, and may be a multilayer structure having four or more layers as long as the inner and outer surfaces of the intermediate metal layer 2b are covered with a resin layer. The tube 2 may not have flexibility. In such a tube 2, the metal layer 2b is exposed at the tube end. Therefore, the insulating joint 1 is configured to connect the pipe end 21 of the pipe 2 in an insulated state.

  The insulating joint 1 has a sleeve portion 5 formed at one end of a metal barrel portion 4, and a case member 6 integrally formed of an insulating material such as a transparent resin is attached to the outside of the sleeve portion 5. . An insertion space 7 for inserting the tube 2 is formed between the outer peripheral surface of the sleeve portion 5 and the inner surface of the case member 6, and the case member 6 is a screw provided at the back end of the insertion space 7. It is fixed to the body part 4 at the joint part 7a. The pipe 2 is inserted from the end of the joint structure 3 into the insertion space 7 between the sleeve portion 5 and the case member 6 along the axial direction. A packing 8 having a constant width in the axial direction is provided around the outer peripheral surface of the sleeve portion 5 to seal the inner peripheral surface of the inserted tube 2 in a watertight manner. However, instead of the packing 8, an O-ring or the like may be provided to seal the tube 2.

  A fixing means 9 is provided at the tip of the case member 6 to fix the tube 2 inserted into the insertion space 7. In the example shown in the figure, the fixing means 9 includes a nut 10 that is screwed into the tip of the case member 6 and a chuck ring 11 that is provided inside the nut 10. The nut 10 and the chuck ring 11 are formed of a metal made of a copper alloy such as brass. The chuck ring 11 is a C-shaped member in which a part of the annular member is cut, and an engaging claw that engages with the outer peripheral surface of the tube 2 is provided on the inner peripheral surface, and the inner diameter thereof is outside the tube 2. It is formed slightly smaller than the diameter. Therefore, when the tube 2 is inserted into the insertion space 7, the engaging claw inside the chuck ring 11 engages with the outer peripheral surface of the tube 2, and the chuck ring 11 expands in diameter, and the inner surface of the nut 10 or the case member 6. It hits. At this time, since the diameter expansion of the chuck ring 11 is restricted, the chuck ring 11 is fixed in an engaged state in which the outer peripheral surface of the tube 2 is held. Here, since the engaging claw of the chuck ring 11 is formed in a taper shape toward the back end of the insertion space 7, the tube 2 can be further inserted toward the back end of the insertion space 7. In the direction in which the tube 2 is pulled out, the engaging claw prohibits the movement of the tube 2 and exhibits a retaining action. For this reason, when the tube 2 is inserted to the far end of the insertion space 7, the tube 2 cannot enter further, and the chucking ring 11 exerts a retaining effect and is fixed to the joint 1. The fixing means 9 is not limited to the above-described structure, and other structures may be adopted. For example, a structure in which a cap nut is provided at the tip of the case member 6 and the tube 2 may be fixed by tightening the cap nut after the tube 2 is inserted into the insertion space 7 is possible.

  Further, a protrusion 12 is provided on the inner surface of the case member 6 so as to protrude inward of the insertion space 7 before the inner end of the insertion space 7. The protrusion 12 is made of an insulating material, and is preferably formed integrally with the inner surface of the case member 6. When the case member 6 and the protrusion 12 are integrally formed, for example, the protrusion 12 is preferably continuously formed in an annular shape along the inner peripheral surface of the case member 6, but the present invention is not limited to this, and intermittently. It may be formed. As shown in FIG. 2, the protrusion 12 is provided so as to contact the tube end 21 of the tube 2 when the tube 2 is inserted to the far end of the insertion space 7. FIG. 3 is an enlarged view of the tube end portion when the tube 2 is inserted into the insertion space 7 and fixed. As shown in FIG. 3, the protrusion 12 formed on the case member 6 is configured to contact at least the end surface of the metal layer 2 b of the tube 2 inserted into the insertion space 7. It is preferable that the protruding width of the protruding portion 12 is set so as to exceed the metal layer 2b exposed at the tube end, and the protruding portion 12 is set so as to cover the entire end surface of the metal layer 2b. Since such a protrusion 12 is formed of an insulating material, the protrusion 12 that contacts the end surface of the metal layer 2b completely insulates the metal layer 2b of the tube 2 and the copper alloy of the body portion 4 from each other. It acts so as not to cause a potential difference between them. As a result, metal corrosion is completely prevented in the insulating joint 1. Note that such a protrusion 12 is formed at any position as long as it is behind the packing 8 in the insertion space 7 of the tube 2 and before the rear end where the screwing portion 7a is formed. It doesn't matter.

  Since such an insulating structure insulates the metal layer end face of the pipe 2 and the body part 4 of the joint 1 by the protrusion 12 provided on the inner surface of the case member 6, the structure is simple and the cost is not increased. Moreover, since the protrusion 12 is provided on the outer side of the body 4 that forms the water channel, the insulating structure does not require a special seal structure. That is, in this insulating joint 1, the water is sealed by the packing 8 that seals the inner peripheral surface of the inserted pipe 2 in a water-tight manner, and the protrusion 12 is provided with a portion that does not come into contact with water. There is no need to have a water stop function, and there is an advantage that the structure can be simplified. Therefore, the insulating joint 1 of the present embodiment can satisfactorily insulate the metal layer 2b exposed at the pipe end 21 of the pipe 2 despite the simple structure.

  In addition, since the case member 6 of the insulating joint 1 is formed of a transparent resin, there is an advantage that the insertion depth of the pipe 2 can be visually recognized from the outside of the insulating joint 1 when the pipe 2 is inserted. In the present embodiment, a position display portion 6 a indicating the proper insertion position of the pipe 2 is provided on the outer periphery of the case member 6. In the illustrated example, the position display portion 6a shows a case in which the rib is formed on the outer periphery of the case member 6 but is not limited to this. For example, the groove may be formed in a ring shape, A proper insertion position may be displayed by drawing a line. By such a position display portion 6a, when the tube is connected, the tube 2 is inserted into the insulating joint 1, and the tube end visible through the case member 6 is inserted to a position beyond the position display portion 6a. It can be confirmed that the tube 2 has been inserted to the proper insertion position. Even when the tube 2 is inserted to the far end where insertion is possible, the metal layer 2b at the tube end abuts against the protrusion 12 and is insulated from the metal body 4, so that metal corrosion is prevented. A good connection state can be obtained. Therefore, the insulation joint 1 of this embodiment is excellent in operability because the work can be performed while confirming the insertion depth of the pipe 2 through the case member 6 when the pipe is connected, and the pipe 2 is inserted to the far end. Sometimes the pipe ends are well insulated so that they are realized as joints that do not cause metal corrosion. The insulating joint 1 has a configuration particularly suitable for insulating and connecting a multi-layered tube in which the metal layer is exposed at the tube end. In addition, by forming the case member 6 from an insulating material, an insulating effect between the metal body 4 and the nut 10 or the chuck ring 11 can be expected.

  Although the present embodiment has been described above, the present invention is not limited to the above-described configuration. For example, in the above-described embodiment, the case member 6 is made of a transparent resin. However, if attention is paid to the insulating effect of the present invention, at least the protrusion 12 only needs to be formed of an insulating material. The member 6 may be formed of other materials. Further, the projection 12 does not need to be entirely made of an insulating material. For example, the projection 12 may be formed by applying an insulating material on the surface of the projection 12.

It is a partial cross section figure of the insulated joint of the state before connecting a pipe | tube. It is a partial cross section figure of the insulation joint in the state where the pipe was connected. It is an enlarged view of a pipe end part when a pipe is inserted and fixed in an insertion space.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation joint 2 Pipe 2a Resin layer 2b Metal layer 2c Resin layer 3 Joint structure 4 Body part 5 Sleeve part 6 Case member 6a Position display part 7 Insertion space 9 Fixing means

Claims (3)

A joint for connecting a pipe having at least a three-layer structure in which a metal layer is provided in the middle and a resin layer is provided inside and outside the metal layer,
A tube insertion space is formed between the cylindrical sleeve portion formed at one end of the metal body and the outer peripheral surface of the sleeve portion, and is fixed to the sleeve portion at the back end portion of the insertion space. A case member, and a fixing means for fixing the tube inserted into the insertion space,
The case member has a protrusion that protrudes inward of the insertion space before the back end and contacts at least a metal layer end surface of the tube inserted into the insertion space, and the protrusion is formed of an insulating material. Insulated joints characterized by that.   The insulating joint according to claim 1, wherein the case member and the protrusion are integrally formed of a transparent resin.   The insulated joint according to claim 2, wherein a position display portion indicating an appropriate insertion position of the pipe is provided on an outer periphery of the case member.

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