JP2536657Y2 - Road heating pipe - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road heating pipe buried in an asphalt pavement for flowing a heat medium in order to prevent snow and freezing on the pavement.

[0002]

2. Description of the Related Art A cross-linked polyethylene pipe used as a floor heating or hot water supply pipe is known as a conventional road heating pipe of this type. FIG. 3 shows an example of a cross section of an asphalt pavement using the crosslinked polyethylene pipe, and the construction is performed in the following procedure. (1) First, crushed stones, gravel, etc. are laid on the ground that has been leveled, and the ground is rolled. (2) Next, a welded wire mesh 12 combined vertically and horizontally is laid on the roadbed 11, and a cross-linked polyethylene pipe 13 is laid on the welded wire mesh 12, and this is fixed to the welded wire mesh 12 with a fixing bracket (not shown). (3) After that, asphalt heated to 150 to 220 ° C. is driven in as a surface layer, and then pressed with a roller. 14 is an asphalt layer obtained in this way.

[0003]

However, in the case of an asphalt pavement, asphalt heated to 150 to 220 ° C. is poured from above the crosslinked polyethylene pipe 13 as described above, so that there are the following problems. (1) The crosslinked polyethylene pipe 13 expands and deforms due to the heat of the asphalt into which it is driven, and swells up and down, making construction difficult. Also, if the construction is performed as it is, pipe 1
Due to the swell, expansion and deformation of 3, the heat medium cannot flow smoothly through it. (2) Since the crosslinked polyethylene pipe 13 comes into direct contact with the asphalt into which it has been driven, components in the asphalt permeate from the surface of the pipe 13 and deteriorate the pipe 13,
Shorten its lifespan. Further, since the pipe 13 is in direct contact with oxygen in the air while being heated to a high temperature, this also deteriorates the pipe 13 and shortens its life. (3) The crosslinked polyethylene pipe 13 may be damaged by direct contact with the welded wire mesh 12, crushed stone, gravel, or the like.

The present invention has been made in order to solve such a conventional problem. When laying, there is no danger of being damaged by a welding wire mesh, crushed stone, or the like.
Is easy, when implanted the asphalt, by the heat hardly occurs expansion or deformation or waviness, asphalt strokes after casting is the color over de heating pipe fear such that deterioration by oxygen component and the air therein The purpose is to provide.

[0005]

The pipe for road heating provided by the present invention is provided by providing a resin layer made of polyolefin on the outer peripheral surface of a pipe body made of cross-linked polyethylene without adhering to the pipe body. It is composed.

The pipe body has an inner diameter of 10 to 30 mm,
Thicknesses of about 1 to 3 mm are standard sizes. Examples of the polyolefin include polypropylene and ultrahigh molecular weight polyethylene. One standard for the thickness of the resin layer is 10 to 1000 μm. The resin layer is provided, for example, without being adhered to the pipe body in the following manner. You
In other words , polyethylene is extruded into a pipe and crosslinked
Then, the outer peripheral surface of the obtained pipe body is
Extrude the polyolefin to a thickness of
Let By "not adhered", specifically, means "in peel strength much less 4 kg / cm". It is preferable that there is no close contact between the pipe body and the resin layer.

[0007]

[Function] (1) The resin layer is adhered to the outer peripheral surface of the pipe body.
Not used for road heating when laying pipes
When the pipe is bent, the pipe body and resin layer are easily separated
And shift in the length direction. This makes it easier to lay the meander.
You. Also, even if the resin layer has scratches, the pipe may be bent.
Stress may concentrate on these flaws and expand.
And the resin layer has come off due to scratches.
I do not. Furthermore, when laying the pipe, the pipe body
There is no risk of damage by touching welded wire mesh, crushed stone, gravel, etc.
No.

(2) Polyolefin constituting the resin layer
Is more heat-resistant than the crosslinked polyethylene that makes up the pipe body
Asphalt casting by selecting the best one
Sometimes asphalt heat is transferred to the pipe body
Effectively shuts off and suppresses expansion and deformation of the pipe body
be able to.

(3) After the asphalt is cast, the resin layer is
Prevents direct contact of asphalt and air with pipe body
Stop, the components in the asphalt and oxygen in the air
The deterioration of the pipe body can be prevented.

[0010]

EXAMPLE A polyethylene pipe was extruded into a pipe having an inner diameter of 13 mm and a wall thickness of 2 mm, which was cross-linked to a degree of cross-linking of 80% to produce a pipe body 1 shown in FIGS. About 500μ by extrusion molding method
The resin layer 2 was provided by extrusion with a thickness to produce a pipe P for road heating.

An asphalt pavement was constructed using the obtained road heating pipe P. The construction was performed in the same manner as the asphalt pavement shown in FIG. In other words, referring to the drawing, a pipe P is placed on a welded wire mesh 12 which is vertically and horizontally combined on a roadbed 11 having a width of 4 m.
Piping is performed in a meandering state at 0 mm intervals, and asphalt heated to 180 ° C. is driven into the asphalt layer 1 having a thickness of 100 mm.
4 were provided.

At the time of construction, the pipe P was carefully observed for the presence or absence of expansion, deformation, and undulation due to the asphalt casting.
As a precautionary measure, the asphalt layer 14 after the construction was broken to examine the presence or absence of expansion, deformation, and undulation of the pipe P. However, no problem in practical use was found.

[0013]

[Effect of the Invention] As described above, according to the pipe of the present invention, the outer peripheral surface of the pipe body of cross-linked polyethylene is
Since the resin layer made of polyolefin is provided without bonding , there is no risk of damage by welding wire mesh or crushed stones when laying, and when asphalt is driven, expansion, deformation or undulation due to heat is generated. Almost no, and after asphalt casting, there is no risk of deterioration due to components therein or oxygen in the air. Further, there is no possibility that the meandering laying of the pipe is hindered by the resin layer as the coating layer.

[Brief description of the drawings]

FIG. 1 is a side view of a pipe for road heating according to an embodiment of the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a cross-sectional view of a conventional asphalt pavement in which a pipe for road heating is embedded.

[Explanation of symbols]

 1 Pipe body 2 Resin layer

Claims (1)

(57) [Scope of request for utility model registration] 1. Extrusion molding of polyethylene into a pipe
Crosslinked inner diameter 10-30mm, wall thickness 1-3mmno
A resin layer made of polyolefin on the outer peripheral surface of the pipe body
Wherein the resin layer is formed outside the pipe.
Extrude polyolefin with a thickness of 10-1000μ on the peripheral surface
Peeling on the pipe body by covering by molding
Formed without bonding so that the strength is 4Kg / cm or less
A road heating pipe characterized by the following.