JPH0698720B2 - Pressure resistant synthetic resin 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 synthetic resin pipe having a high pressure resistance, which is mainly used by being laid in the ground such as a sewer pipe, a drain pipe, a protective pipe for electric wires and telephone lines. Is.

[0002]

2. Description of the Related Art Conventionally known pressure-resistant synthetic resin pipes of this type include, for example, Japanese Utility Model Laid-Open No. 61-1418.
As disclosed in Japanese Patent Publication No. 89, a structure in which a reinforcing member made of a thin metal plate having a cross-sectional shape substantially equal to the pipe wall of a resin pipe formed in a spiral wave shape is arranged, There is a body integrated with the reinforcing body by welding, fusion, adhesion or the like.

[0003]

In the conventional pressure-resistant synthetic resin tube represented by the one disclosed in the above-mentioned publication, the thermal expansion coefficient of the resin which is the constituent material of the tube and the constituent material of the reinforcing body. Since the coefficient of thermal expansion of the metal is remarkably different, the resin pipe is cracked or punctured due to changes in the environmental temperature, etc., and as a result, the metal reinforcement disposed inside the pipe wall is oxidatively corroded, It has the drawbacks that it is corroded by the influence of groundwater and the desired pressure resistance cannot be maintained, and when it is used as a fluid pipe for groundwater or the like, it causes an unexpected leak of fluid.

In particular, this type of pressure-resistant synthetic resin pipe tends to be thinned by incorporating a reinforcing member, which is a serious problem. The present invention has been made in view of the above circumstances, and it is possible to prevent cracks and punctures in the pipe wall due to the difference in the coefficient of thermal expansion, and to secure desired pressure resistance and safe fluid flowability. An object is to provide a pressure resistant synthetic resin pipe.

[0005]

In order to achieve the above object, a pressure-resistant synthetic resin pipe according to the present invention has a hollow space within a spiral reinforcing strip formed on the outer periphery of the resin pipe in a hollow space inside the reinforcing strip. And a reinforcing member made of a thin metal plate having a cross-sectional shape substantially along both side wall portions connected to the peak portion and the synthetic resin pipe are inserted in a non-integrated state.

[0006]

According to the pressure-resistant synthetic resin pipe of the present invention having the above-mentioned structure, when it is used by being buried in the ground, the spiral resin pipe and the resin are against the compressive load such as earth pressure. The metal reinforcing member inserted in the spiral hollow space of the pipe cooperates and opposes to exert a strong pressure resistance.

Even when the resin pipe wall and the metal reinforcing body have different thermal expansion degrees due to changes in the ambient temperature, etc., when they are buried in the ground as described above, they are non-integral structures. The resin-made pipe wall and the metal-made reinforcing body are independently expanded, so that the low-strength pipe wall can be prevented from cracking or puncturing.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a partially cutaway front view of a pressure resistant synthetic resin pipe, FIG.
1 is an enlarged vertical sectional view of the main part of FIG. 1, in which FIG.
Is a resin pipe made of polyethylene resin or the like, 2 is a hollow spiral reinforcing strip having a rectangular cross section, and the resin pipe 1 and the reinforcing strip 2 are rectangular cross sections that are open downward, and both open end portions are One of which is long and the other is short, and a resin strip material having both side edges that are projected laterally outward,
It is formed by sequentially spirally winding the long and short side edge portions in a state where they overlap each other.

Reference numeral 3 denotes a reinforcing member which is inserted into the closed hollow space 4 of the reinforcing strip 2 and which is made of a thin metal plate such as a thin iron plate, a stainless steel plate or a steel plate having a thickness of about 0.3 mm to 1.0 mm. The reinforcing body 3 has a cross-sectional shape which is the peak 2a of the reinforcing strip 2.
Along with the top plate portion 3a, and both side wall portions 2b, 2b continuous to the top portion 2a, and both side plate portions 3b, 3b substantially along, the central portion of the top plate portion 3a, the resin One projecting portion 3c projecting in a U-shape toward the pipe 1 side is integrally bent, and such a reinforcing body 3 is not integrated with the resin pipe 1, It is inserted in the hollow space 4 of the reinforcing strip 2.

3 to 6 show another embodiment of the present invention. In the embodiment shown in FIG. 3, the mountain top plate portion 3a of the reinforcing member 3 faces the resin pipe 1 side. The two bent portions 3c, 3c projecting close to the outer surface of the pipe 1 are integrally bent, and the number of bent portions 3c may be three or more.

In the embodiment shown in FIG. 4 and FIG. 5, one or two protruding portions 3c formed by integrally bending the mountain top plate portion 3a of the above-mentioned reinforcing member 3 are hollow spaces toward the resin pipe 1 side. 4 is projected to a height equivalent to about one half of that of the No. 4, and in the case of the embodiment shown in FIGS. 4 and 5, the pressure resistance strength is slightly lower than that of the embodiment shown in FIGS. Compared with the one having no protruding portion 3c at all, the pressure resistance can be remarkably improved by the rib effect. In other words, the metal plate can be made thinner in order to obtain the same compressive strength, and it is easy to reduce the weight of the entire tube.

In the embodiment shown in FIG. 6, the reinforcing strip 2 is formed in a spiral corrugated shape in cross section, and the reinforcing member 3 in this embodiment also has a protruding portion 3c protruding toward the hollow space 4 side. The number is not limited to one and may be two or more.

FIG. 7 shows another embodiment in which the reinforcing member 3 having no above-mentioned curved portion 3c is inserted into the hollow space 4, and the present invention also includes the structure shown in FIG. . Further, when the constituent material of the reinforcing body 3 is a thin strip iron plate or a steel plate, a synthetic resin film may be laminated to prevent the surface from rusting.

[0014]

As described above, according to the present invention, the reinforcing member made of a thin metal plate having a cross-sectional shape substantially along the inner surface of the hollow space is inserted in the hollow space of the spiral reinforcing strip. , The entire pipe wall is made considerably thin, and the structure is easily bent at the resin single wall portion located between the adjoining reinforcements, which is excellent in flexibility and can significantly increase the pressure resistance. In particular, according to the present invention, the reinforcing body and the resin pipe are non-integral and are physically separated from each other, so that they are different from each other due to a change in environmental temperature. Even if thermal expansion is performed to a certain degree, there is no fear that the pipe wall will be cracked or punctured by the reinforcing body.

Therefore, even when used under conditions where the environmental temperature changes drastically, the desired compressive strength can be secured stably.
Further, when used as a fluid flow pipe, there is an effect that an unexpected leak can be prevented and safe flowability can be secured.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view,

FIG. 2 is an enlarged vertical sectional view of a main part,

FIG. 3 is an enlarged vertical cross-sectional view of a main part showing another embodiment,

FIG. 4 is an enlarged vertical cross-sectional view of a main part showing another embodiment,

FIG. 5 is an enlarged vertical cross-sectional view of a main part showing another embodiment,

FIG. 6 is an enlarged vertical sectional view of a main part showing another embodiment,

FIG. 7 is an enlarged vertical cross-sectional view of a main part showing another embodiment.

[Explanation of symbols] 1 resin pipe 2 reinforcing strip 3 reinforcing body 3c projecting portion 4 hollow space

Claims (3)

[Claims] 1. A pressure-resistant synthetic resin pipe in which a hollow resin-made reinforcing strip is integrally formed on the outer periphery of a resin pipe in a spiral shape. In a hollow space within the reinforcing strip, a peak portion of the reinforcing strip and the peak portion are formed. A pressure-resistant synthetic resin pipe, wherein a reinforcing member made of a thin metal plate having a cross-sectional shape substantially along both side wall portions continuous with is inserted into the synthetic resin pipe in a non-integrated state. 2. The pressure-resistant synthetic resin pipe according to claim 1, wherein the reinforcing body has at least one projecting portion projecting from the top plate portion thereof into the hollow space. 3. The pressure resistant synthetic resin pipe according to claim 1, wherein a synthetic resin film is laminated on the reinforcing body.