JP2000170965A - Connecting structure of polybutene pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting structure of a polybutene pipe capable of easily connecting with other pipes by a simple structure, excellent in durability and water-tightness. SOLUTION: This connecting structure is constituted of a polybutene pipe 1, a flange 11 projected and formed at least one tip part 17 of the polybutene pipe 1 and an engaging tool 2 which is idly fitted and fixed into/to an outer periphery of the polybutene pipe 1 on a back face 18 sides of the flange 11. The flange 11 is constituted by being formed by heating and softening the polybutene pipe 1 itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a connection structure and a manufacturing method for a polybutene pipe, which has conventionally been extremely difficult to connect with another pipe because an adhesive used for bonding the polybutene resin has not been developed. About.

[0002]

2. Description of the Related Art Conventionally, a metal pipe is connected to a hot water supply pipe such as a water heater through a metal joint. In this case, the metal pipe has a flange protruding in the radial direction, and is connected to the metal joint by a cap nut or the like via a rubber packing or the like. However, in this case, different metals are used for the metal pipe and the metal joint. This is because the metal pipe is required to have characteristics such as bending workability, and the metal joint is required to have characteristics such as cutting workability of a thread portion.

[0003] Since the metal pipe and the metal joint are made of different metals, a potential difference occurs between the two and so-called electrolytic corrosion may occur. Therefore, it is difficult to use the device for a long period of time especially under high temperature such as hot water. Further, in order to bend the metal pipe into a desired shape at a plumbing site, a processing tool and a processing operation are required. Also, it is very difficult to bend in complicated directions.

Therefore, in order to avoid the above-mentioned electrolytic corrosion, it has been proposed to use a polybutene resin which is excellent in heat resistance, elasticity, flexibility and workability.

[0005]

However, there is no adhesive in polybutene resin that can be bonded to others. for that reason,
When a polybutene pipe is used instead of a metal pipe, for example, a complicated connection structure as shown in FIG. 5 must be adopted.

That is, as shown in FIG.
The hole 91 of the end 92 of the polybutene pipe 9 is screwed into the small-diameter projection 811 of the above, and the rubber packing 82 disposed on the outer periphery of the polybutene pipe 9 is fitted onto the end 92. Further, the cap nut 83 is fitted on the rubber packing 82, and the female screw portion 833 of the cap nut 83 is connected to the metal joint 8.
The male screw portion 812 is screwed.

At this time, the tapered portion 831 of the cap nut 83
This reduces the diameter of the cylindrical portion 821 of the rubber packing 82 and the end 92 of the polybutene pipe 9 and presses and fixes it on the small-diameter projection 811 of the metal joint 81. Therefore, the polybutene pipe 9 is connected to the metal joint 81.

The through hole 826 of the rubber packing 82
Is substantially equal to the outer diameter of the polybutene pipe 9. Also,
The flange 822 of the rubber packing 82 is
The third tapered portion 831 is pressed against the peripheral portion. The metal joint 81 is connected to the male screw 81 through a hexagon 813.
A male screw portion 814 disposed on the opposite side of the hot water supply pipe 2 is threadably connected to a female screw portion (not shown) of the hot water supply pipe.

During hot water supply, hot water supplied from a water heater (not shown) is supplied from the hot water supply pipe through a through hole 816 of the metal joint 81 and a hole 91 of the polybutene pipe 9.

The present invention has been made in view of the above-mentioned conventional problems, and has a simple structure, can be easily connected to other pipes, and has excellent durability and watertightness. It seeks to provide structure.

[0011]

According to a first aspect of the present invention, there is provided a polybutene pipe, a flange protruding from at least one end of the polybutene pipe, and a loosely fitted outer periphery of the polybutene pipe on the rear side of the flange. And a flange formed by heating and softening the polybutene pipe itself.

The most remarkable point in the present invention is that the flange is formed at the end of the polybutene pipe by heating and softening the polybutene pipe itself, and the engaging member is provided on the outer periphery of the polybutene pipe. Is provided.

Polybutene (PB), which is a raw material of a polybutene pipe, is a synthetic resin produced by polymerizing 1-butene, and is a polyolefin resin similar to polyethylene (PE) and polypropylene (PP). The average molecular weight of polybutene is as large as about 1.2 million. Polybutene pipes are also described in, for example, JIS, K6792.

When connecting the polybutene pipe of the present invention to another pipe or joint such as a hot water supply pipe, first, a flange formed at an end of the polybutene pipe is connected to another pipe (or joint, hereinafter referred to as a joint). A). Next, the engaging member disposed on the outer periphery of the polybutene pipe is connected to the other pipe. The flange of the polybutene pipe is pressed against the other pipe by the engaging tool and is closely fixed.

Next, the operation of the present invention will be described. In the present invention, since the above-mentioned polybutene pipe has electrical insulation properties, even if other pipes to be connected are made of metal, they do not corrode electrolytically. The flange of the polybutene pipe has elasticity as a physical property of the polybutene resin itself. For this reason, by pressing the flange with the engaging tool, water leakage can be prevented instead of the rubber packing shown in the conventional example. Therefore, the rubber packing is not always necessary. Further, the flange is formed integrally with the end of the polybutene pipe, and a joining means for both is unnecessary.

Therefore, the connection structure of the polybutene pipe is simplified. In addition, the work of connecting to the other pipes is facilitated. In addition, the flange of the polybutene pipe has much higher heat resistance than the rubber packing shown in the conventional example, so that the flange can be reliably prevented from thermal deterioration, and the durability and watertightness are greatly improved. Can be done.

Next, it is preferable that the engaging member is a cap nut having a screw portion.
In this case, the polybutene pipe can be reliably connected by screwing the screw portion of the engagement tool to the other pipe. The screw portion may be provided on the inner circumference of the cap nut or on the outer circumference. That is, the screw portion may be a female screw or a male screw.

Next, according to a third aspect of the present invention, in manufacturing a polybutene pipe having at least one end provided with a protruding flange, the end of the polybutene pipe is pressed against a flange forming tool having a heater. A method of forming a flange on the end by heating and softening the end, wherein the flange forming tool is provided around a rod-shaped protrusion for inserting a hole of the polybutene pipe and a periphery of the rod-shaped protrusion. A method for producing a polybutene pipe, comprising: a processing part for forming the outer shape of the flange; and a heater for heating the processing part.

In the above manufacturing method, first, the bar-shaped projection of the flange forming tool is inserted into the hole of the polybutene pipe, and the end of the polybutene pipe is brought into contact with the processed portion of the flange forming tool. Next, the processing part is heated by the heater of the flange forming tool, and the end of the polybutene pipe is pressed against the processing part. Then, the end of the polybutene pipe is heated and softened along the heated processed portion to protrude the flange.

According to the manufacturing method, by heating and softening the end of the polybutene pipe, the flange can be easily formed from the polybutene pipe itself.

Next, as in the fourth aspect of the present invention, it is preferable that the rod-shaped projection has substantially the same diameter as the hole of the polybutene pipe. In this case, the flange can be formed without reducing the diameter of the hole of the polybutene pipe.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 4 show a connection structure of a polybutene pipe and a method of manufacturing a polybutene pipe according to an embodiment of the present invention.
This will be described with reference to FIG. As shown in FIGS. 1 and 2, the connection structure of the polybutene pipe of this example is
A flange 11 protruding from at least one end 17 of the polybutene pipe 1;
On the side, the engaging member 2 is loosely fitted to the outer periphery 12 of the polybutene pipe 1. The flange 11 is formed by heating and softening the polybutene pipe 1 itself.

The details will be described below. The engaging device 2 is shown in FIGS.
As shown in FIG. 2, it is a cap nut having a female screw portion 21 as a screw portion. The engagement tool 2 has an engagement portion 22 that engages with the back surface 18 of the flange 11. The engaging portion 22 is provided with a through hole 24 through which the main body of the polybutene pipe 1 is inserted.

When connecting the polybutene pipe 1 of this embodiment to a hot water supply pipe 39 as another pipe via the joint 3, first, as shown in FIGS.
The flange 11 formed at the end 17 of the polybutene pipe 1 is brought into contact with the side surface of the male screw portion 31 of the joint 3.
The joint 3 is screwed and connected to the female screw portion 390 of the hot water supply pipe 39 by a male screw portion 33 disposed on the opposite side of the male screw portion 31 via a hexagonal portion 32.

The engaging portion 22 of the engaging member 2 is located on the back surface 18 of the flange 11 of the polybutene pipe 1.
Is engaged. Next, the female screw portion 21 of the engagement tool 2 is screwed into the male screw portion 31 of the joint 3. This gives
The polybutene pipe 1 is connected to the hot water supply pipe 39 via the joint 3. Flange 1 of polybutene pipe 1
1 is pressed against the side surface of the male screw portion 31 of the joint 3 to be closely fixed.

During hot water supply, hot water supplied from a water heater (not shown) is supplied from the hot water supply pipe 39 to the hot water supply pipe 39.
The through hole 30 of the joint 3 and the hole 1 of the polybutene pipe 1
Hot water is supplied through 0.

Next, a method for manufacturing the polybutene pipe 1 will be described with reference to FIGS. In the above manufacturing method, as shown in FIGS. 3 and 4, the end portion 17 of the
Is pressed to heat and soften the end portion 17 to form the flange 11 on the end portion 17.

As shown in FIG. 3, the flange forming tool 4 has a cylindrical rod-like projection 42 into which the hole 10 of the polybutene pipe 1 is inserted, and is provided around the rod-like projection 42 outside the flange 11. It has a bottomed cylindrical processing part 43 for shaping the shape, and a heater 41 for heating the processing part 43.

The rod-like projection 42 has substantially the same diameter as the hole 10 of the polybutene pipe 1. The processing portion 43 is composed of a cylindrical body 431 disposed coaxially with the rod-shaped protrusion 42, and a base 432 formed perpendicular to the rod-shaped protrusion 42, and the end 17 is inserted therebetween. The annular groove 430 is formed.

The heater 41 is provided in a main body 40 disposed below the base portion 432.
A heat generating portion is disposed opposite to the heat generating portion 32. An outlet 46 is connected to the heater 41. Further, a heat insulating material 45 is provided in the main body 40 of the flange forming tool 4,
The heat insulating material 45 insulates the lower part of the heater 41.

In the method for processing the flange 11 of the polybutene pipe 1, first, as shown in FIG.
The processing section 43 is heated by the heater 41.
Next, the hole 10 of the polybutene pipe 1 is inserted into the rod-shaped projection 42 of the flange forming tool 4, and the end 17 of the polybutene pipe 1 is connected to the processing section 4 of the flange forming tool 4.
3 and is pressed against.

Thus, as shown in FIG. 4B, the end 17 of the polybutene pipe 1 is softened by the heated working portion 43 and then softened until it comes into contact with the cylindrical portion 431 along the base 432. It bends to form the flange 11 protruding.

Next, as shown in FIG. 4C, the heating by the heater 41 is stopped, and after the flange 11 is cooled and hardened, the polybutene pipe 1 is pulled out from the rod-shaped projection 42. In addition, if necessary, the back surface 18 of the flange 11 may be subjected to cutting or the like so that the flange 11 has a desired thickness.

Next, the operation of this embodiment will be described. In the connection structure of the polybutene pipe of this example, since the polybutene pipe 1 has an electrical insulating property, even if the joint 3 to be connected is a metal, they are not electrolytically corroded. The flange 11 of the polybutene pipe 1 has elasticity as a physical property of the polybutene resin itself. Therefore, when the flange 11 is pressed by the engagement member 2, water leakage can be prevented instead of the rubber packing shown in the conventional example. Therefore, the rubber packing is not always necessary. Further, the flange 11 is formed integrally with the end portion 17 of the polybutene pipe 1, and a joining means for both is unnecessary.

Therefore, the connection structure of the polybutene pipe 1 is simplified. Also, the work of connecting to the joint 3 is facilitated. Further, since the flange 11 of the polybutene pipe 1 has extremely high heat resistance as compared with the rubber packing shown in the conventional example, thermal deterioration of the flange 11 can be surely prevented, and durability and watertightness are improved. It can be greatly improved.

The engaging member 2 is a cap nut having a female screw portion 21. Therefore, the female thread portion 21 of the engagement tool 2 can be screwed into the joint 3 to reliably connect the polybutene pipe 1.

Further, according to the method for manufacturing a polybutene pipe of this embodiment, the flange 11 can be easily formed from the polybutene pipe 1 itself by heating and softening the end portion 17 of the polybutene pipe 1.

The rod-shaped projection 42 of the flange forming tool 4 has substantially the same diameter as the hole 10 of the polybutene pipe 1. Therefore, the flange 11 can be formed without reducing the diameter of the hole 10 of the polybutene pipe 1. Therefore, at the time of hot water supply, hot water flows from the through hole 30 of the joint 3 to the hole 1 of the polybutene pipe 1.
The pressure loss that occurs when passing through zero can be minimized.

[0039]

As described above, according to the present invention, there is provided a polybutene pipe connection structure which can be easily connected to other pipes with a simple structure, and is excellent in durability and water tightness. Can be.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional explanatory view of a connection structure of a polybutene pipe in an embodiment.

FIG. 2 is an exploded perspective view of a connection structure of a polybutene pipe in the embodiment.

FIG. 3 is an explanatory cross-sectional perspective view of a flange forming tool in the embodiment.

FIG. 4 is an explanatory view of a method for processing a flange of a polybutene pipe in the embodiment.

FIG. 5 is a partial cross-sectional explanatory view of a connection structure of a polybutene pipe in a conventional example.

[Explanation of symbols]

 1. . . Polybutene pipe, 10 . . Hole, 11. . . Flange, 17. . . Edge, 2. . . Engaging device, 3. . . 3. fittings; . . Flange forming tool, 41. . . Heater, 42. . . Bar-shaped projections, 43. . . process section,

Claims (4)

[Claims] 1. A polybutene pipe, a flange protruding from at least one end of the polybutene pipe,
A connection structure for a polybutene pipe, characterized in that it comprises an engagement tool loosely fitted on the outer periphery of the polybutene pipe on the back side of the flange, and the flange is formed by heating and softening the polybutene pipe itself. . 2. The connection structure for a polybutene pipe according to claim 1, wherein the engagement tool is a cap nut having a threaded portion. 3. When manufacturing a polybutene pipe having a flange formed at least at one end thereof, the end of the polybutene pipe is pressed against a flange forming tool having a heater, and the end is heated and softened. A method of forming a flange at the end, wherein the flange forming tool is provided with a rod-shaped projection for inserting a hole of the polybutene pipe, and is formed around the rod-shaped projection to form an outer shape of the flange. A method for producing a polybutene pipe, comprising: a processing part; and a heater for heating the processing part. 4. The rod-shaped projection according to claim 3,
A method for producing a polybutene pipe, wherein the diameter of the polybutene pipe is substantially the same as that of the hole of the polybutene pipe.