JP2002039488A - Pipe connecting structure and pipe fitting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate tight continuation and connection of pipes with each other while its operations remain simple. SOLUTION: The pipe connecting structure is to generate continuation and connection of pipes with each other by fitting a cylindrical fixation part 1 on a pipe P and fastening, wherein the cylindrical fixation part is formed from a thermoplastic resin and equipped with thermocontracting property whereby the inner diameter becomes smaller than the pipe outside diameter with heating, and contraction is made with heating in the condition that the cylindrical fixation part is fitted on the pipe to be fitted thereon fast.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe connection structure in which a cylindrical fixing portion is externally fitted and fixed to a pipe so that the pipes are connected to each other, and a pipe joint used for the pipe connection structure.

[0002]

2. Description of the Related Art The above-mentioned pipe connection structure does not abut the end face of the tubular fixing part and the end face of the pipe, but fits the tubular fixing part to the pipe and connects the pipes with each other. The pipes can be easily connected to each other without requiring high dimensional accuracy.However, conventionally, the cylindrical fixing part whose inner diameter is slightly larger than the outer diameter of the pipe is used so that the cylindrical fixing part does not easily fit outside the pipe. Are externally fitted to the pipes to connect the pipes to each other.

[0003]

For this reason, there is a disadvantage that it is difficult to tightly connect and connect the pipes. Further, the tubular fixing portion and the tube are formed of a thermoplastic resin, and the tubular fixing portion is heated in a state of being fitted to the tube so that the inner peripheral surface of the tubular fixing portion and the outer peripheral surface of the tube are mutually heated. When connecting by fusing, it is difficult to heat the tube with the inner peripheral surface of the tubular fixing part firmly adhered to the outer peripheral surface of the pipe, so it is difficult to thermally fuse the tubular fixing part and the pipe firmly. In particular, when the tubular fixing portion and the tube are formed of a thermoplastic resin such as a cross-linked polyethylene resin having a low flowability even when melted, the molten resins are less likely to fuse with each other, and the connection strength is reduced. There is a disadvantage that it is difficult to secure. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to enable pipes to be tightly connected to each other while allowing them to be easily connected to each other.

[0004]

According to a first aspect of the present invention, there is provided a pipe connection structure in which a tubular fixing portion is externally fixed to a pipe and the pipes are connected to each other. The tubular fixing portion is formed of a thermoplastic resin, and the tubular fixing portion is provided with a heat-shrinking property such that the inner diameter thereof is reduced by heating so that the inner diameter becomes smaller than the outer diameter of the tube. Is shrunk by heating in a state of being externally fitted to the tube, and externally fitted and fixed to the tube. (Action) Since the cylindrical fixing portion that contracts so that the inner diameter becomes smaller than the outer diameter of the tube by heating is shrunk by heating in a state of being externally fitted to the tube, and is externally fitted and fixed to the tube, The inner peripheral surface of the tubular fixing portion can be strongly adhered to the outer peripheral surface of the tube by tightening the tube by the contraction force of the cylindrical fixing portion. [Effect] Since the inner peripheral surface of the cylindrical fixing portion is strongly brought into close contact with the outer peripheral surface of the tube and can be fitted and fixed to the outer surface of the tube, the tubes can be easily connected to each other while the tubes are connected easily. can do.

According to a second feature of the present invention, the tube is formed of a thermoplastic resin, and a cylindrical frame for preventing deformation of the tube accompanying shrinkage of the cylindrical fixing portion is provided inside the tube. The tubular fixing portion is shrunk by heating in a state where the tubular fixing portion is externally fitted to the tube, and the inner peripheral surface of the tubular fixing portion and the outer peripheral surface of the tube are thermally fused to each other. [Function] In order to be able to effectively tighten a tube formed of a thermoplastic resin by the contraction force of the cylindrical fixing portion, a deformation accompanying the radial contraction of the cylindrical fixing portion is formed inside the tube. When the tubular frame to be prevented is provided as a reaction force receiver, and the tubular fixing portion is fitted to the tube, the inner peripheral surface of the tubular fixing portion strongly adheres to the outer peripheral surface of the tube, and the molten resin fuses. The tubular fixing portion is contracted by heating so that the inner peripheral surface of the tubular fixing portion and the outer peripheral surface of the tube can be thermally fused to each other so as to facilitate the fusion. [Effect] The inner peripheral surface of the cylindrical fixing portion is strongly adhered to the outer peripheral surface of the pipe, and the inner peripheral surface of the cylindrical fixing portion and the outer peripheral surface of the pipe are thermally fused with each other in a state where the molten resins are easily fused. Because it can be attached, it is easy to heat weld the cylindrical fixed part and the tube firmly, and even when the cylindrical fixed part and the tube are formed of a thermoplastic resin that has poor fluidity even if it is melted, It is easy for resins to fuse together and to ensure connection strength.

According to a third aspect of the present invention, there is provided a pipe joint provided with a tubular fixing portion which can be externally fitted to a pipe end,
The tubular fixing portion is formed of a thermoplastic resin having a heat-shrinking property that shrinks by heating so that the inner diameter becomes smaller than the outer diameter of the pipe to be connected. [Operation] A tubular fixing portion formed of a thermoplastic resin having a heat shrink property that shrinks so that the inner diameter becomes smaller than the outer diameter of the pipe to be connected, in a state of being externally fitted to the pipe end. It can be shrunk by heating and can be fitted onto the end of the tube, so the tube end is tightened by the shrinking force of the tube fixing part, and the inner peripheral surface of the tube fixing part is strongly adhered to the outer peripheral surface of the tube end Can be done. [Effect] Since the inner peripheral surface of the cylindrical fixing portion is strongly adhered to the outer peripheral surface of the tube end and can be externally fitted and fixed to the tube end, the tube end can be easily connected and connected between the tubes. Close communication can be established between them.

[0007] A characteristic feature of the invention according to claim 4 is that the inner peripheral surface of the cylindrical fixing portion and the outer peripheral surface of a thermoplastic resin tube end portion fitted with the cylindrical fixing portion are heated. The point is that a heating means for heat fusion is provided. [Function] In a state where the tubular fixing portion is fitted to the end of the thermoplastic resin tube, the inner peripheral surface of the tubular fixing portion is strongly adhered to the outer peripheral surface of the tube end, and the molten resins are fused together. To make it easier,
The cylindrical fixing portion is contracted by heating, and the inner peripheral surface of the cylindrical fixing portion and the outer peripheral surface of the tube end portion can be heated and fused to each other by the heating means. Further, the inner peripheral surface of the tubular fixing portion and the outer peripheral surface of the tube end can be thermally fused while the tubular fixing portion is contracted by heating by the heating means. [Effect] The inner peripheral surface of the cylindrical fixing portion is strongly adhered to the outer peripheral surface of the tube end portion, and in a state where the molten resins are easily fused with each other, the inner peripheral surface of the cylindrical fixing portion and the outer peripheral surface of the tube end portion are combined. Can be thermally fused to each other, so that the tubular fixing part and the pipe end are easily heat-fused firmly, and the tubular fixing part and the pipe end are made of a thermoplastic resin having a low fluidity even when melted. Even if it is formed, the molten resins are easily fused together, and the connection strength is easily ensured. In addition, when the inner peripheral surface of the cylindrical fixing portion and the outer peripheral surface of the pipe end are heat-fused while the cylindrical fixing portion is contracted by heating by the heating means, the contraction of the cylindrical fixing portion is performed. No additional heating means is required, and the pipe connection operation can be simplified.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 shows a pipe connection in which two resin pipes P made of a thermoplastic resin (cross-linked polyethylene resin in this embodiment) for supplying city gas are connected to each other in a concentric manner in an airtight manner. 1 shows a structure and a pipe joint A provided with a tubular fixing part 1 which can be externally fitted to a pipe end of a resin pipe P used for the pipe connection structure. The pipes P are externally fitted and fixed to the pipe ends and are heat-sealed to each other.

The pipe joint A is made of a thermoplastic resin (a thermoplastic resin (1) integrally formed at both ends with a cylindrical fixing portion 1 externally fixed to a resin pipe P.
In this embodiment, the cylindrical joint body 2 made of a crosslinked polyethylene resin), the inner peripheral surface 8 of the cylindrical fixing portion 1 and the outer peripheral surface 9 of the resin pipe P on which the cylindrical fixing portion 1 is fitted are heated. Heating means 3 for heat-sealing each other, and fixing each cylindrical fixing portion 1 to the resin pipe P by external fitting, the inner peripheral surface 8 of the cylindrical fixing portion 1 and the outer peripheral surface 9 of the resin pipe P Are thermally fused to each other to connect the two resin pipes P to each other.

The heating means 3 applies an electric heating wire, such as a copper-nickel alloy wire, which generates Joule heat upon energization, along the vicinity of the inner peripheral surface 8 of each cylindrical fixing portion 1 and over both cylindrical fixing portions 1. 2, and as shown in FIG. 2, the power supply controller 4 is configured to be embedded in a zigzag manner along the circumferential direction in a state where it is folded back at the end of the cylindrical fixing portion 1. Two connection terminals 6 for connecting the power supply connector 5 to the heating wire 3 are provided.

The joint body 2 shrinks by heating the crosslinked polyethylene resin forming each cylindrical fixing portion 1 so that the inner diameter d becomes smaller than the outer diameter D of the resin pipe P to be connected. In order to provide heat shrinkage, Fig. 2 (a),
As shown in (b), after the joint body 2 provided with the tubular fixing portion 1 having the inner diameter d smaller than the outer diameter D of the resin pipe P is injection-molded together with the heating wire 3, the inner peripheral surface thereof is moved in the radial direction. Pressing outward, as shown in FIG. 3, stretches in the circumferential direction so that the inner diameter d of the cylindrical fixing portion 1 is slightly larger than the outer diameter D of the resin pipe P, and at room temperature in the stretched state. Cooled.

Incidentally, when the injection-molded joint body 2 is stretched,
Although the heating wire 3 is pulled in the circumferential direction, since the heating wire 3 is embedded in a zigzag along the circumferential direction, it is easy to follow the circumferential extension of the tubular fixing portion 1 and the heating wire 3 is broken. There is little fear.

A steel tubular frame 7 for preventing deformation of the resin tube P due to shrinkage of the tubular fixing portion 1 is fitted as a reaction force receiving member to the inner peripheral surface of the end of each resin tube P. The heating wire 3 is heated to about 300 ° C. to shrink the joint body 2 in a state where the tubular fixing portion 1 is fitted to the resin pipe P, and the tubular fixing portion 1 is fitted to each resin pipe P. At the same time, the contact portion between the cylindrical fixing portion 1 and the resin tube P is heated to about 230 ° C., and the inner peripheral surface 8 of the cylindrical fixing portion 1 and the outer peripheral surface 9 of the resin tube P are thermally fused to each other. is there.

[Second Embodiment] FIG. 4 shows a pipe in which two resin pipes P made of thermoplastic resin (cross-linked polyethylene resin in this embodiment) for supplying city gas are connected to each other concentrically. Another embodiment of a connection structure and a pipe joint A used for the pipe connection structure is shown, and a branch pipe connection portion 10 for connecting a branch pipe is provided between the tubular fixing portions 1 of the joint body 2.
Other configurations are the same as those of the first embodiment.

[Third Embodiment] FIG. 5 shows two resin pipes P made of thermoplastic resin (cross-linked polyethylene resin in this embodiment) for supplying city gas which are concentrically and air-tightly connected to each other. FIG. 4 shows another embodiment of a pipe connection structure and a pipe joint A used in the pipe connection structure, and a locking ridge 12 on an inner peripheral side of a tubular fixing portion 1 provided in the pipe joint A; Seal ring mounting groove 13 for mounting rubber seal ring 11
Are formed integrally in an annular shape, and a fitting groove 14 in which the locking ridge 12 is fitted is formed in an annular shape at the outer peripheral end of the resin pipe P,
The cylindrical fixing portion 1 is externally fitted and fixed to the resin pipe P with the seal ring 11 interposed therebetween.

The pipe joint A is formed in a cylindrical shape made of a thermoplastic resin (a crosslinked polyethylene resin in the present embodiment).
Cylindrical fixing portions 1 that are externally fitted and fixed to the resin pipe P are integrally formed at both ends thereof.
In order to provide a heat-shrinking property to shrink the outer diameter D of the resin pipe P so as to be smaller than the outer diameter D of the resin pipe P, a pipe joint A having an inner diameter d of the cylindrical fixing portion 1 smaller than the outer diameter D of the resin pipe P After the injection molding, the inner peripheral surface is pressed radially outward, and is stretched in the circumferential direction so that the inner diameter d1 of the locking ridge 12 is slightly larger than the outer diameter D of the resin pipe P. In the stretched state, it is cooled to room temperature.

A cylindrical frame 7 for preventing deformation of the resin tube P due to shrinkage of the cylindrical fixing portion 1 is provided on the inner peripheral surface of the end of each resin tube P, and each cylindrical fixing portion 1 is attached to the resin tube P With the high-temperature steam blown from the steam pipe B, the pipe joint A is heated and contracted, the locking ridge 12 is fitted into the fitting groove 14, and the seal ring 11 is made of resin. Each of the cylindrical fixing portions 1 is airtightly and externally fixed to each of the resin pipes P by being sandwiched between the outer peripheral surfaces of the pipes P in a compressed and deformed state. still,
In the present embodiment, a heating means such as a heating wire for heating the pipe joint A may be embedded, and the pipe joint A may be contracted by heating by the heating means. Other configurations are the same as those of the first embodiment.

[Fourth Embodiment] FIG. 6 shows two ends of two resin pipes P made of a thermoplastic resin (cross-linked polyethylene resin in this embodiment) for supplying city gas, which are directly connected concentrically. FIG. 4 shows a pipe connection structure in which a connecting protrusion 12 is provided on an inner peripheral side of a cylindrical fixing portion 1 provided on one end side of a resin pipe P;
And a seal ring mounting groove 13 for mounting a rubber seal ring 11 are integrally formed in a ring shape, and a fitting protrusion 12 is fitted on the outer peripheral side on the other end side of the resin pipe P. Groove 1
4 is formed in an annular shape, and the cylindrical fixing portion 1 is
Is fixed to the resin tube P with the outside.

The resin tube P is provided with a heat-shrinking property such that the cylindrical fixed portion 1 contracts by heating so that the inner diameter d becomes smaller than the outer diameter D of the resin tube P, as shown in FIG. As shown in FIG. 1, a resin pipe P having a locking ridge 12 and a seal ring mounting groove 13 at one end and a fitting groove 14 at the other end.
After injection molding, the inner peripheral surface at one end side is pressed radially outward, and as shown in FIG.
Are stretched in the circumferential direction so that the inner diameter d1 of the resin tube P is slightly larger than the outer diameter D of the resin tube P, and the stretched state is cooled to room temperature.

A cylindrical frame 7 is provided on the inner peripheral surface on the other end side of each resin tube P to prevent the cylindrical fixing portion 1 from being deformed due to contraction. In the fitted state,
The cylindrical fixing part 1 is heated and shrunk by high-temperature steam blown from the steam pipe B, and the locking ridge 12 is fitted into the fitting groove 14.
In addition, the seal ring 13 is sandwiched between the outer peripheral surface of the resin tube P in a compressed deformation state, and the cylindrical fixing portion 1 is externally fitted and fixed to the resin tube P in an airtight manner. In the present embodiment, a heating means such as a heating wire for heating the pipe joint A may be embedded, and the pipe joint A may be contracted by heating by the heating means. Other configurations are the same as those of the first embodiment.

[Other Embodiments] The pipe connection structure and the pipe joint according to the present invention may be a pipe connection structure and a pipe joint for connecting pipes at a bent portion of the pipe. 2. The pipe connection structure according to the present invention may be one in which the pipe and the connection pipe provided on the valve side are connected and connected. 3. The pipe joint according to the present invention may have a valve function, or may be a cap for closing a pipe end. 4. In the pipe connection structure and the pipe joint according to the present invention, when the inner peripheral surface of the tubular fixing portion and the outer peripheral surface of the pipe are thermally fused to each other, the tubular fixing portion may be contracted and then thermally fused. Alternatively, the contraction of the tubular fixing portion and the heat fusion may be performed simultaneously. 5. The pipe connection structure and the pipe joint according to the present invention may be provided with a dedicated heating means for contracting the cylindrical fixing portion. 6. The pipe connection structure and the pipe joint according to the present invention include a heating means for shrinking the cylindrical fixing portion when the inner peripheral surface of the cylindrical fixing portion and the outer peripheral surface of the pipe are thermally fused to each other; And a heating means for heat-sealing the two to each other may be separately provided. 7. The pipe connection structure and the pipe joint according to the present invention may be those that connect and connect a resin pipe to a metal pipe or between metal pipes. 8. The pipe connection structure and the pipe joint according to the present invention may use a polyethylene resin, a polybutene resin, a polyvinyl chloride resin, a polypropylene resin, or the like as the thermoplastic resin. 9. The pipe connection structure and the pipe joint according to the present invention may be a pipe connection structure and a pipe joint for a liquid pipe such as a water pipe or a sewer pipe.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a pipe connection structure.

FIG. 2 is an explanatory view of a pipe joint.

FIG. 3 is an explanatory view of a pipe joint.

FIG. 4 is a sectional view showing a pipe connection structure according to a second embodiment.

FIG. 5 is a sectional view showing a pipe connection structure according to a third embodiment.

FIG. 6 is a sectional view showing a pipe connection structure according to a fourth embodiment.

FIG. 7 is an explanatory view of a pipe according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical fixing part 3 Heating means (heating wire) 7 Cylindrical frame D Outer diameter d Inner diameter P Tube

Claims (4)

[Claims] 1. A pipe connection structure in which a tubular fixing portion is externally fitted and fixed to a pipe and the pipes are connected to each other so as to communicate with each other, wherein the tubular fixing portion is formed of a thermoplastic resin and has a cylindrical shape. The fixing portion is provided with a heat-shrinking property to shrink so that the inner diameter becomes smaller than the outer diameter of the tube by heating, and the tubular fixing portion is shrunk by heating in a state of being externally fitted to the tube. A pipe connection structure that is externally fixed to the pipe. 2. The tube is formed of a thermoplastic resin, and a tubular frame is provided inside the tube to prevent deformation of the tube due to shrinkage of the tubular fixing portion. The pipe connection structure according to claim 1, wherein the pipe connection structure is shrunk by heating in a state of being externally fitted to the pipe, and the inner peripheral surface of the cylindrical fixing portion and the outer peripheral face of the pipe are thermally fused to each other. 3. A pipe joint provided with a tubular fixing portion which can be fitted outside at a pipe end, wherein the tubular fixing portion has an inner diameter smaller than an outer diameter of a pipe to be connected by heating. Pipe joint made of a thermoplastic resin having a heat shrinking property to shrink as described above. 4. A heating means for heating an inner peripheral surface of the cylindrical fixing portion and an outer peripheral surface of a thermoplastic resin tube end portion to which the cylindrical fixing portion is fitted so as to thermally fuse them together. The pipe joint according to claim 3, wherein