JPH07217776A - Ribbed bellowslike pipe and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a bellowslike pipe which can be used in a curved part of a pipe line, instead of a curved pipe, and which can be suitably used for a pipe line buried underground, by circumferentially arranging several flange-like ribs on the outer surface of a pipe wall, and by circumferentially arranging outward curved parts between the ribs. CONSTITUTION:A ribbed bellowslike pipe P1 made of thermoplastic resin is circumferentially formed at the outer surface of its wall with several flange-like ribs 11, and outward curved parts 12 are circumferentially arranged between the all ribs 11. This bellowslike pipe P1 can be curved in its entirety by bending with no heating, due to deformation of the ribs, and accordingly, the pipe can be directly bend at a predetermined angle while generated stress is retained within an allowable range. In the manufacture of the ribbed pipe P, the pipe P is softened by heating, except of the ribs 11, with the use of a silicon rubber heater, and a core S is inserted in the ribbed pipe P. The core material S has an outer diameter substantially equal to the inner diameter of the ribbed pipe P with a short length. This core material S is axially pressed and is then pulled out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ribbed bellows tube mainly used for a bent portion of a pipe and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a ribbed pipe in which a large number of ribs are provided around the outer surface of a pipe wall has been proposed and is being adopted as an underground buried pipe (see Japanese Patent Laid-Open No. 163587/1990). However, as for this ribbed tube, only a straight tube has been proposed so far, and therefore a bent tube is used in the bent portion of the piping. This bent pipe is generally a straight pipe made of a thermoplastic resin having no ribs provided around it and heated and bent (see Japanese Patent Application No. 3-37319).

[0003]

However, in the bent pipe described above, a plurality of kinds of bent pipes having different bending angles must be prepared in order to correspond to various bent portions having different bending angles, so that various kinds of small amounts can be obtained. There was a problem that production was required and the manufacturing cost was high.

Incidentally, there is a bellows tube which can be used for the bent portion of the pipe instead of the bent tube. However, since this bellows tube has a weak strength in the direction orthogonal to the tube axis, it cannot be used as a sewer pipe or the like. There is a problem that it is not suitable for use as such underground piping.

Therefore, the present invention focuses on the above problems,
Can be used in the bent part of the pipe instead of the bent pipe,
Moreover, it is a first object to provide a ribbed bellows tube suitable for use as a pipe for underground burying, and to provide a manufacturing method capable of easily and inexpensively manufacturing the ribbed bellows tube. Is the second purpose.

[0006]

In order to achieve the above first object, in the ribbed bellows tube of the present invention, a large number of ribs are provided around the outer surface of the tube wall, and A bent portion that bends outward is provided around the rib.
The ribbed bellows tube may be provided with a rising branch portion on the tube wall.

In order to achieve the above second object,
In the method for manufacturing a ribbed bellows tube of the present invention, after heating and softening a portion other than the ribs of the thermoplastic resin ribbed tube in which a large number of collar-shaped ribs are provided around the outer surface of the tube wall, the ribbed tube Between the ribs of the ribbed tube by inserting a core into the inside of the ribbed tube and applying an axial compressive force to the ribbed tube to cause the ribbed tube to contract while sliding along the outer surface of the core. A bent portion that bends outward is provided around the.

[0008]

In the ribbed bellows tube according to claim 1 of the present invention and the ribbed bellows tube according to claim 2 of the present invention, even if a bending force is applied without heating, the entire tube is bent by the deformation of the bent portion. It is possible to perform the raw bending at a desired angle while keeping the stress generation within the allowable range.

Further, a bent portion appears as a concave portion on the inner surface of the ribbed bellows tube, and this concave portion suppresses an increase in the velocity of the water flow. It can also be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the structure of the ribbed bellows tube of the first embodiment will be described with reference to FIG.

FIG. 1 is a partial sectional view showing a ribbed bellows tube of the first embodiment.

This ribbed bellows pipe P1 is a thermoplastic resin pipe, and a large number of ribs 11 having a brim shape are provided around the outer surface of the pipe wall, and between all the ribs 11 and the ribs 11,
A bent portion 12 that is bent outward is provided around the bent portion 12. The thermoplastic resin used to form the ribbed bellows tube P1 may be polyvinyl chloride resin, polyethylene resin, polypropylene resin, or the like.

The ribbed bellows tube P1 is bent by the deformation of the bent portion 12 even if a bending force is applied without heating, so that the generation of stress is within the allowable range. It can be bent to the desired angle as shown. That is, the ribbed bellows pipe P1 of the present embodiment is not only suitable for use as a pipe for underground burying because it has the rib 11, but also can be bent live at the site, so that the pipe bends instead of the bend pipe. It can also be used for parts.

Further, since the bent portion 12 is shown as a concave portion on the inner surface of the ribbed bellows pipe P1, the concave portion suppresses an increase in the velocity of the water flow. In other words, since it can be used in a straight area in a steep area to prevent jumping water and jet flow, it is possible to reduce the number of manholes installed. The construction cost can be reduced.

Next, a method of manufacturing the ribbed bellows pipe P1 of the first embodiment will be described with reference to FIGS.

When manufacturing the ribbed bellows tube P1,
First, as shown in FIG. 3, a rib 11 having a collar shape is formed on the outer surface of the pipe wall.
The parts other than the ribs 11 of the ribbed pipe P made of a thermoplastic resin, which is provided around a large number, are heated and softened. A band-shaped silicon rubber heater H is used as a heating means, and the silicon rubber heater H is wound between the ribs 11 to generate heat.

Next, the silicon rubber heater H is removed, and the core material S is inserted inside the ribbed pipe P as shown in FIG. As the core material S, a cylindrical body having an outer diameter substantially equal to the inner diameter of the ribbed pipe P is used. The core material S is slightly shorter than the ribbed pipe P, and the end portions of the ribbed pipe P are left on both sides of the core material S.

As shown in FIG. 5, both ends of the ribbed pipe P in which the core material S is inserted are attached to the attachment A of the compressor.
The ribbed pipe P is contracted while sliding along the outer surface of the core material S by applying a compressive force F in the axial direction to the ribbed pipe P by a compressor, and the ribs 11 and 11 of the ribbed pipe P A bent portion 12 that is bent outward is provided between the two. The core material S is inserted into the ribbed pipe P only when the rib 11 and the rib 11 are inserted.
This is to prevent the space between and from bending inward.

After cooling, the ribbed pipe P is attached to the attachment A.
To remove the core material S. As described above, the manufacturing of the ribbed bellows tube P1 is completed.

As described above, in the manufacturing method of this embodiment, the existing ribbed pipe P can be used, and since no mold is required, the bellows pipe with ribs is very simple and inexpensive. P1 can be manufactured.

Next, the construction of the ribbed bellows tube of the second embodiment will be described with reference to FIG.

FIG. 6 is a partial cross-sectional view showing the ribbed bellows tube of the second embodiment.

The ribbed bellows tube P2 is a thermoplastic resin tube similar to the ribbed bellows tube P1 of the first embodiment.
A large number of collar-shaped ribs 21 are provided around the outer surface of the pipe wall. Further, the ribbed bellows tube P2 is provided with a rising branch portion 22 in the middle portion, and a bent portion 23 that is bent outward is provided between the ribs 21 and the ribs 21 other than the middle portion. Has been done.

In this ribbed bellows tube P2, even if a bending force is applied without heating, the tube end portion is bent by the deformation of the bent portion 23, so that the generation of stress is within the allowable range, and as shown in FIG. It can be bent to a desired angle as shown in FIG. In other words, the ribbed bellows pipe P2 of the present embodiment is not only suitable for use as a pipe for underground burying because it has the ribs 21, but also can be live-bent at the site, so that a pipe pipe instead of a bent pipe is used. It can also be used in the bend.
Further, since the rising branch portion 22 is provided on the pipe wall, it can be used for a part of the pipe that requires the inspection port and the cleaning port.

Further, since the bent portion 23 is shown as a concave portion on the inner surface of the ribbed bellows pipe P2, the first embodiment is also capable of preventing jumping and jetting by being used in a straight state in a steep area. It is common with the ribbed bellows tube P1 of the example.

Next, a method of manufacturing the ribbed bellows pipe P2 of the second embodiment will be described with reference to FIGS.

When manufacturing the ribbed bellows tube P2,
First, as shown in FIG. 8, a rib 21 having a collar shape is formed on the outer surface of the pipe wall.
A hole h is made in the pipe wall of the thermoplastic resin ribbed pipe P around which a large number of holes are provided, and the peripheral portion of the hole h is heated and softened.
As a heating means, a hole h formed in the ribbed pipe P is used.
A larger silicon rubber heater H is used, and the silicon rubber heater H is inserted inside the ribbed pipe P and applied to the inner surface of the peripheral portion of the hole h to generate heat.

Next, as shown in FIG. 9, a drawing die K is inserted into the ribbed pipe P, the drawing die K is pulled up from the hole h of the ribbed pipe P, and the peripheral edge of the hole h is raised and rises. The branch portion 22 is formed. In addition, this pull-out mold K
Are left in the rising branch unit 22.

Next, as shown in FIG. 10, the ribbed pipe P
A silicon rubber heater H is wound between the ribs 21 and ribs 21 other than the middle portion to heat and soften the ribbed pipe P.

Next, the silicon rubber heater H is removed, and as shown in FIG. 11, the core material S is placed inside the ribbed pipe P.
Insert. As the core material S, a cylindrical body having an outer diameter substantially equal to the inner diameter of the ribbed pipe P is used. The core material S is slightly shorter than the ribbed pipe P, and the end portions of the ribbed pipe P are left on both sides of the core material S.

Then, as shown in FIG. 12, the drawing die K is placed in the rising branch portion 22 provided at the peripheral portion of the hole h.
While leaving the core material S, both ends of the ribbed pipe P in which the core material S is inserted are applied to the attachment A of the compressor, and the compression force F in the axial direction is applied to the ribbed pipe P by the compressor to core the ribbed pipe P. The material S is made to slide and contract along the outer surface of the material S, and a bent portion 23 bent outward is provided between the rib 21 and the rib 21 other than the middle portion of the ribbed pipe P. Rib tube P with core material S
The reason why the ribs are inserted is to prevent the ribs 21 from being bent inward. The reason why the drawing die K is left in the rising branch portion 22 is to prevent the sectional shape of the rising branch portion 22 from being collapsed by the compressive force F.

After cooling, the ribbed pipe P is attached to the attachment A.
And the core material S and the withdrawal die K are removed. As described above, the manufacture of the ribbed bellows tube P2 is completed.

As described above, in the manufacturing method of this embodiment, the existing ribbed pipe P can be used, and since no die is required, the ribbed bellows pipe is very simple and inexpensive. P2 can be manufactured.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the scope of the present invention. Also included in the present invention. For example, in the embodiment, an example in which a cylindrical body having an outer diameter substantially equal to the inner diameter of the ribbed tube is used as the core material is shown. However, after the rubber tube is used, the rubber tube is inserted inside the ribbed tube. Alternatively, the rubber tube may be inflated with compressed air or the like and pressure-bonded to the inner surface of the ribbed tube.

[0035]

As described above, the ribbed bellows pipe according to claim 1 of the present invention and the ribbed bellows pipe according to claim 2 of the present invention are ribbed and therefore used as underground pipes. Not only is it suitable for use in, but it is possible to use it in the bent portion of the pipe instead of the bent pipe because it can be bent at a desired angle.
Furthermore, since the bent portion appears as a concave portion on the inner surface and the concave portion suppresses the increase in the velocity of the water flow, it is possible to prevent jumping and jet flow in a steep area.

Further, in the ribbed bellows pipe according to the second aspect of the present invention, since the rising and branching portion is provided on the pipe wall, it can be used for a part of the pipe which requires the inspection port and the cleaning port.

Further, in the method of manufacturing the ribbed bellows tube according to the third aspect of the present invention, the existing ribbed tube can be used, and since no mold is required, it is very simple and inexpensive. The effect that a ribbed bellows tube can be manufactured is obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a ribbed bellows tube of a first embodiment.

FIG. 2 is a partial cross-sectional view showing a bent state of the ribbed bellows tube of the first embodiment.

FIG. 3 is a front view for explaining the manufacturing method of the ribbed bellows tube of the first embodiment.

FIG. 4 is a cross-sectional view for explaining the method of manufacturing the ribbed bellows tube of the first embodiment.

FIG. 5 is a cross-sectional view for explaining the method for manufacturing the ribbed bellows tube of the first embodiment.

FIG. 6 is a partial sectional view showing a ribbed bellows tube of a second embodiment.

FIG. 7 is a partial cross-sectional view showing a bent state of the ribbed bellows tube of the second embodiment.

FIG. 8 is a cross-sectional view illustrating a method of manufacturing a ribbed bellows tube according to a second embodiment.

FIG. 9 is a cross-sectional view for explaining the method for manufacturing the ribbed bellows tube of the second embodiment.

FIG. 10 is a front view for explaining the method of manufacturing the ribbed bellows tube of the second embodiment.

FIG. 11 is a cross-sectional view for explaining the method of manufacturing the ribbed bellows tube of the second embodiment.

FIG. 12 is a cross-sectional view for explaining the method of manufacturing the ribbed bellows tube of the second embodiment.

[Explanation of symbols]

 P1 ribbed bellows tube 11 rib 12 bent part P2 ribbed bellows tube 21 rib 22 rising branch part 23 bent part

Claims (3)

[Claims] 1. A rib characterized in that a large number of flange-shaped ribs are provided on the outer surface of the pipe wall, and an outwardly bent portion is provided between the ribs. Bellows tube with. 2. The ribbed bellows tube according to claim 1, wherein a rising branch portion is provided on the tube wall. 3. A core material is inserted into the inside of the ribbed pipe after heating and softening a portion other than the ribs of a thermoplastic resin ribbed pipe in which a large number of ribs are provided around the outer surface of the pipe wall. Then
An axial compressive force is applied to the ribbed tube to cause the ribbed tube to slide and contract along the outer surface of the core material, thereby surrounding the bent portion of the ribbed tube that bends outward between the ribs. A method for manufacturing a ribbed bellows tube, which is characterized by being installed.