JP3288065B2 - Manufacturing method of synthetic resin-lined branch pipe joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a branch pipe joint whose inner surface is lined with a synthetic resin.

[0002]

2. Description of the Related Art Conventionally, when lining the inner surface of a branch pipe joint with a synthetic resin, first, a synthetic resin pipe having thermal expansion properties is inserted into a main pipe of the branch pipe joint and heated to expand radially. Then, the inner surface of the main pipe is lined, and thereafter, the pipe wall of the synthetic resin pipe is perforated so as to open to the branch pipe side of the branch pipe joint. Then, the synthetic resin pipe having thermal expansion property is inserted into the branch pipe of the branch pipe joint, and the end of the synthetic resin pipe on the branch pipe side is wrapped and bonded to the periphery of the hole of the synthetic resin pipe on the main pipe side. A method is known in which a synthetic resin pipe on the side of a branch pipe is heated to expand in the radial direction to line the inner surface of the branch pipe.

[0003] The same procedure as above is performed until a synthetic resin pipe having thermal expansion properties is inserted into the branch pipe of the branch pipe joint, and the end of the synthetic resin pipe on the branch pipe side is connected to the synthetic resin pipe on the main pipe side. There is also known a method of heating the synthetic resin tube on the side of the branch pipe after welding to the periphery of the hole and expanding the pipe in the radial direction to line the inner surface of the branch pipe.

[0004]

However, the method for producing a synthetic resin-lined branch pipe joint employing the above-mentioned conventional lining processing method has the following problems.

In the former method, sufficient adhesive strength cannot be obtained unless the end of the synthetic resin pipe on the side of the branch pipe is wrapped around the periphery of the hole of the synthetic resin pipe on the side of the main pipe. If the apertures are the same or nearly the same, poor adhesion locations are likely to occur. In other words, if the diameter of the main pipe and the branch pipe are the same or almost the same, the shape of the hole provided in the synthetic resin pipe on the main pipe side will be such that it goes deep inside the pipe wall, and the total length of the edge of the hole Becomes extremely long, so that the end of the synthetic resin pipe on the side of the branch pipe must also substantially conform to the shape of the hole, and the end of the synthetic resin pipe on the side of the branch pipe must be aligned with the hole of the synthetic resin pipe on the main pipe. This is because it is extremely difficult to wrap around the entire circumference.

In the latter method, the gap between the synthetic resin pipe on the branch pipe side and the edge of the hole of the synthetic resin pipe on the main pipe side can be filled with the resin in which the welding rod is melted, but the diameter of the main pipe and the branch pipe is reduced. Are closer to each other, the welding distance becomes longer, so that the working efficiency is greatly reduced. In addition, since welding work was performed after drilling holes in the pipe wall of the synthetic resin pipe on the main pipe side, there is a risk that the resin that melted the welding rod may fall out of the holes and adhere to the inner surface of the main pipe. There is also a problem that the amount of flow in the pipe is reduced due to the beads remaining inside the joint between the resin pipe and the synthetic resin pipe on the branch pipe side.

The present invention has been made in view of the above problems, and it is a first object of the present invention to line the inner surface of a branch pipe joint with a synthetic resin without any gap and to prevent beads from being left inside the synthetic resin. A second object is to line the inner surface of the branch pipe joint with a synthetic resin without any gaps and to improve the working efficiency.

[0008]

In the present invention, in order to achieve the first object, a thermally expandable synthetic resin pipe is inserted into a main pipe of a branch pipe joint and heated to expand radially. After lining the inner surface of the main pipe, a synthetic resin pipe having thermal expansion properties is inserted into the branch pipe of the branch pipe joint, and welded or butt-fused to the pipe wall of the synthetic resin pipe on the main pipe side. Piercing the pipe wall on the main pipe side by inserting a piercing blade from the synthetic resin pipe on the side, and then heating the synthetic resin pipe on the branch pipe side to expand in the radial direction to line the inner surface of the branch pipe. Means.

In the present invention, in order to achieve the second object, a synthetic resin pipe having thermal expansion properties is inserted into each of the main pipe and the branch pipe of the branch pipe joint, and then the synthetic resin pipe on the branch pipe side is inserted. Is butt-fused to the periphery of a hole provided in the pipe wall of the synthetic resin pipe on the main pipe side, and then the synthetic resin pipes on the main pipe side and the branch pipe side are heated to expand radially so that the main pipe and the branch pipe A method of lining the inner surface is used.

[0010]

In the method for manufacturing a synthetic resin-lined branch pipe joint according to claim 1, the synthetic resin pipe on the branch pipe side is welded or butt-fused to the pipe wall of the synthetic resin pipe on the main pipe side, and then the synthetic pipe on the branch pipe side is synthesized. Since the synthetic resin pipe on the main pipe side is pierced by inserting a drilling blade from the resin pipe, the beads generated inside the seam between the synthetic resin pipe on the main pipe side and the synthetic resin pipe on the branch pipe side are:
When the synthetic resin tube on the main tube side is pierced, it is cut together with the tube wall of the synthetic resin tube. That is, the inner surface of the synthetic resin tube can be finished smoothly.

In the method for manufacturing a synthetic resin-lined branch pipe joint according to the second aspect of the present invention, the synthetic resin pipe on the branch pipe side is butt-fused to the peripheral portion of the hole provided in the synthetic resin pipe on the main pipe side. The working time can be greatly reduced as compared with the case of. Since the time required for butt fusion is not so affected by the diameter of the branch pipe, it is particularly advantageous when the diameters of the main pipe and the branch pipe are the same or almost the same. Further, since the synthetic resin tubes are fused before the lining, the fusion work is easily performed, and high joining accuracy can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. First, a method for manufacturing a synthetic resin-lined branch pipe joint according to a first embodiment will be described with reference to FIGS.

When the inner surface of the branch pipe joint 1 is lined with a synthetic resin, first, a thermoplastic synthetic resin pipe (for example, a vinyl chloride resin pipe) P1 having thermal expansion properties is connected to the main pipe 11 of the branch pipe joint 1. Insert At this time, the synthetic resin pipe P
1 has a slightly smaller diameter and is longer than the main pipe 11, and is positioned so that both ends protrude from the flanges 12 at both ends of the main pipe 11 (see FIG. 1). Note that an adhesive is applied to the outer surface of the synthetic resin pipe P1.

Next, the synthetic resin pipe P1 is heated and softened, and is preferably pressed against the inner surface of the main pipe 11 of the branch pipe joint 1 while expanding radially by applying pressure. That is, the inner surface of the main pipe 11 is lined with the synthetic resin pipe P1 (see FIG. 2). In addition, air pressure may be used for pressurizing the synthetic resin pipe P1, and water pressure may be used. Further, both ends of the synthetic resin pipe P1 are brought into close contact with flanges 12 provided at both ends of the main pipe 11.

Next, a thermoplastic synthetic resin pipe (for example, a vinyl chloride resin pipe) P2 having a thermal expansion property is connected to the branch pipe joint 1
Of the synthetic resin pipe P1 on the side of the main pipe 11 is welded or butt-fused. At this time, a synthetic resin pipe P2 having a slightly smaller diameter and a longer diameter than the branch pipe 13 is used, and one end thereof protrudes from the flange portion 14 at the tip of the branch pipe 13 (see FIG. 3). In addition,
An adhesive is applied to the outer surface of the synthetic resin pipe P2.
Further, the synthetic resin pipe P2 on the side of the branch pipe 13 needs to be processed in advance in such a shape that one end matches the pipe wall of the main pipe 11. When welding, the synthetic resin pipe P1,
If a welding rod made of the same material as P2 is used and there is a gap between the synthetic resin pipes P1, the gap is filled with the molten resin of the welding rod so that the end of the synthetic resin pipe P2 on the branch pipe 13 side becomes the main pipe. 11
To the tube wall of the synthetic resin tube P1 on the side over the entire length in the circumferential direction. In the case of butt fusion, both the pipe wall of the synthetic resin pipe P1 on the main pipe 11 side and the end face of the synthetic resin pipe P2 on the branch pipe 13 side are heated and melted using a heater or the like, and the melted portions are pressed together. By tightly contacting in this state, the end of the synthetic resin pipe P2 on the branch pipe 13 side is joined to the pipe wall of the synthetic resin pipe P1 on the main pipe 11 over the entire length in the circumferential direction.

Next, the main pipe 11 is inserted by inserting a piercing blade such as a forsaw from the synthetic resin pipe P2 on the branch pipe 13 side.
A hole 15 having a size substantially equal to the inner diameter of the synthetic resin pipe P2 on the side of the branch pipe 13 is formed in the synthetic resin pipe P1 on the side (see FIG. 4). At this time, the main pipe 1 is welded or butt-fused.
The bead B generated inside the seam between the synthetic resin pipe P1 on the first side and the synthetic resin pipe P1 on the branch pipe 13 is cut together with the pipe wall of the synthetic resin pipe P1 on the main pipe 11 side.

Then, the synthetic resin pipe P2 on the side of the branch pipe 13 is heated and softened, heated and expanded radially to line the inner surface of the branch pipe 13. Further, one end of the synthetic resin pipe P2 is brought into close contact with a flange section 14 provided at the tip of the branch pipe 13 (see FIG. 5). At this time, the end of the synthetic resin pipe P2 on the side of the branch pipe 13 is joined to the pipe wall of the synthetic resin pipe P1 on the side of the main pipe 11 over the entire length in the circumferential direction. No gaps are created.

That is, in the method of manufacturing a synthetic resin-lined branch pipe joint according to the present embodiment, the inner surface of the branch pipe joint 1 can be lined without gaps with the synthetic resin pipes P1 and P2. The inner surfaces of the synthetic resin pipes P1 and P2 can be finished smoothly without leaving beads at the joints between the pipes P1 and P2. Synthetic resin pipes P1, P2
If it is necessary to smooth the inner surface of the branch pipe joint 1 closely, the synthetic resin pipes P1 and P2 may be pressed against the inner surface of the branch pipe joint 1 using a roller.

When the end of the synthetic resin pipe P2 on the side of the branch pipe 13 is joined to the wall of the synthetic resin pipe P1 on the side of the main pipe 11 by means of butt fusion, welding is employed. The working time can be greatly reduced as compared with the case of.

Next, a method of manufacturing the synthetic resin-lined branch pipe joint according to the second embodiment will be described with reference to FIGS.

When the inner surface of the branch pipe joint 1 is lined with a synthetic resin, first, a thermoplastic synthetic resin pipe having thermal expansion properties (for example, a vinyl chloride resin pipe) P3, P4
Is inserted into each of the main pipe 11 and the branch pipe 13 of the branch pipe joint 1, and the synthetic resin pipe P4 on the branch pipe 13 side is butt-fused to the periphery of the hole 16 provided in the synthetic resin pipe P3 on the main pipe 11 side. At this time, the synthetic resin pipe P3 on the main pipe 11 side has a slightly smaller diameter and is longer than the main pipe 11, and is positioned so that both ends protrude from the flanges 12 at both ends of the main pipe 11.
The synthetic resin pipe P4 on the side of the branch pipe 13 has a slightly smaller diameter and is longer than the branch pipe 13, and one end thereof protrudes from the flange portion 14 at the tip of the branch pipe 13 (see FIG. 6).
Note that an adhesive is applied to the outer surface of the synthetic resin pipe P1. Further, the synthetic resin pipe P4 on the side of the branch pipe 13 needs to be processed in advance so that one end matches the pipe wall of the main pipe 11. The time when the holes 16 are provided in the synthetic resin pipe P3 on the main pipe 11 side may be before or after the synthetic resin pipe P3 is inserted into the main pipe 11. Further, at the time of butt fusion, the tube wall of the synthetic resin pipe P3 on the main pipe 11 side and the end face of the synthetic resin pipe P4 on the branch pipe 13 side are both heated and melted using a heater or the like, and the melted portions are pressed against each other. The close contact causes the end of the synthetic resin pipe P4 on the side of the branch pipe 13 to be joined to the tube wall of the synthetic resin pipe P3 on the side of the main pipe 11 over the entire length in the circumferential direction. At the time of butt fusion, if an inner mold is inserted inside each of the synthetic resin tubes P3 and P4, it is possible to prevent beads from being generated inside.

Next, the synthetic resin pipe P3 on the main pipe 11 side and the synthetic resin pipe P4 on the branch pipe 13 side are heated and radially expanded to line the inner surfaces of the main pipe 11 and the branch pipe 13. Further, both ends of the synthetic resin pipe P3 on the main pipe 11 side are brought into close contact with flanges 12 provided at both ends of the main pipe 11 to form a branch pipe 13.
One end of the synthetic resin pipe P4 on the side is brought into close contact with a flange 14 provided at one end of the branch pipe 13 (see FIG. 7).
At this time, the end of the synthetic resin pipe P4 on the side of the branch pipe 13 is connected to the main pipe 1
Since it is joined to the tube wall of the synthetic resin tube P3 on one side over the entire length in the circumferential direction, after lining, the synthetic resin tube P3
There is no gap between P4.

That is, in the method of manufacturing a synthetic resin-lined branch pipe joint according to this embodiment, the inner surface of the branch pipe joint 1 can be lined without gaps with the synthetic resin pipes P3 and P4, and butt fusion is performed. Synthetic resin pipe P on branch pipe 13 side
4 is joined to the pipe wall of the synthetic resin pipe P3 on the main pipe 11 side, so that the working time can be greatly reduced as compared with the case of welding. Before lining, synthetic resin pipe P
Since P3 and P4 are fused, fusion work is easily performed, and high joining accuracy is obtained. Furthermore, since the lining work on the inner surface of the main pipe 11 and the lining work on the inner surface of the branch pipe 13 are performed simultaneously, the working time can be greatly reduced.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. Are also included in the present invention. For example, in the embodiment, the branch pipe joint (cheese) in which the branch pipe is provided only at one place of the main pipe is illustrated, but the branch pipe joint (header) in which the branch pipe is provided at several places of the main pipe is illustrated. The present invention can be applied to a case where a lining process is performed.

[0025]

According to the method of manufacturing a synthetic resin-lined branch pipe joint according to claim 1 of the present invention, the synthetic resin pipe on the branch pipe side is welded or butt-fused to the pipe wall of the synthetic resin pipe on the main pipe side. Since the synthetic resin pipe on the main pipe side is pierced by inserting a drilling blade from the synthetic resin pipe on the branch pipe side, the inner surface of the branch pipe joint can be lined with a synthetic resin pipe without gaps, and The effect is obtained that beads can be prevented from remaining inside the tube.

In the method for manufacturing a synthetic resin-lined branch pipe joint according to claim 2 of the present invention, the synthetic resin pipe on the branch pipe side is butt-fused to a peripheral portion of a hole provided in the synthetic resin pipe on the main pipe side. Therefore, the inner surface of the branch pipe joint can be lined with a synthetic resin pipe without any gap, and the working time can be greatly reduced as compared with the case of welding. In addition, since the synthetic resin pipes before the lining are fused together, the fusion work is easily performed, and an effect that high joining accuracy is obtained can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a stage in which a synthetic resin pipe having thermal expansion properties is inserted into a main pipe of a branch pipe joint in a method of manufacturing a synthetic resin-lined branch pipe joint according to a first embodiment.

FIG. 2 is a cross-sectional view showing a stage in which the main pipe of the branch pipe joint is lined in the method of manufacturing a synthetic resin-lined branch pipe joint according to the first embodiment.

FIG. 3 is a cross-sectional view showing a stage in which a synthetic resin pipe having thermal expansion properties is inserted into a branch pipe of the branch pipe joint in the method of manufacturing a synthetic resin-lined branch pipe joint according to the first embodiment.

FIG. 4 is a cross-sectional view illustrating a stage in which a pipe wall of a synthetic resin pipe on the main pipe side is perforated in the method of manufacturing a synthetic resin-lined branch pipe joint according to the first embodiment.

FIG. 5 is a cross-sectional view showing a stage of lining the branch pipe of the branch pipe joint in the method of manufacturing a synthetic resin-lined branch pipe joint according to the first embodiment.

FIG. 6 is a cross-sectional view showing a step of inserting a synthetic resin pipe into a main pipe and a branch pipe of a branch pipe joint in the method of manufacturing a synthetic resin-lined branch pipe joint according to the second embodiment.

FIG. 7 is a cross-sectional view showing a stage in which the main pipe and the branch pipe of the branch pipe joint are lined in the method of manufacturing the synthetic resin-lined branch pipe joint according to the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Branch pipe joint 11 Main pipe 13 Branch pipe P1, P2 Synthetic resin pipe

Claims (2)

(57) [Claims] 1. A heat-expandable synthetic resin pipe is inserted into a main pipe of a branch pipe joint, heated and radially expanded to line an inner surface of the main pipe, and then the heat-expandable synthetic resin pipe is branched. It is inserted into the branch pipe of the pipe joint and welded or butt-fused to the pipe wall of the synthetic resin pipe on the main pipe side, and a drilling blade is inserted from the synthetic resin pipe on the branch pipe side to pierce the pipe wall on the main pipe side. Then, the synthetic resin pipe on the branch pipe side is heated and expanded in the radial direction to line the inner surface of the branch pipe, thereby producing a synthetic resin-lined branch pipe joint. 2. A hole formed in a pipe wall of a synthetic resin pipe on a main pipe side after inserting a synthetic resin pipe having thermal expansion property into each of a main pipe and a branch pipe of a branch pipe joint. A synthetic resin lining branch, characterized in that the main resin tube and the branch pipe are heated and expanded radially to line the inner surfaces of the main pipe and the branch pipe. Manufacturing method of pipe fittings.