JPH0726628Y2 - Pressure resistant synthetic resin pipe - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is a pressure resistant synthetic resin suitable for use as a large-diameter wire protection tube or other underground buried tube that is required to have pressure resistance, or as a fluid conduit. It is about pipes.

[Conventional technology]

Conventionally, fume pipes and cast iron pipes have been used because pressure resistant strength is required for underground buried pipes.
It is difficult to handle due to its large weight for its diameter, and it has a difficulty in workability.

Therefore, for example, as described in Japanese Utility Model Laid-Open No. 61-141889, a cross section U is formed on the outer periphery of a cylindrical wall made of synthetic resin.
A pressure resistant synthetic resin pipe has been developed in which a reinforcing strip made of a metal thin plate is spirally wound and integrated at a predetermined pitch, and the reinforcing strip is covered with a spiral ridge made of synthetic resin.

[Problems to be solved by the device]

However, according to this pressure-resistant synthetic resin pipe, the reinforcing strip made of a thin metal plate is bent in the width direction in a U-shaped cross section, and the side wall plate portions are formed on both sides of the top face portion over the whole. Not only is it difficult to form such a bending molding with high precision, but when the top surface of the wall is bent into a circular shape, a bending force acts in the plate surface direction of both side wall plate parts. Therefore, it is difficult to manufacture a small-diameter pipe because it cannot be bent greatly.

Furthermore, in order to manufacture a large-diameter pipe, it is necessary to increase the height of a mountain bent into a U-shaped cross section, but the higher the mountain, the more difficult it is to bend. In either case, it cannot be easily manufactured.

Further, the cross-sectional shape of the reinforcing strip made of a thin metal plate is flared by the horizontal flange portions formed at both ends thereof. Therefore, when the reinforcing strip is bent along the forming axis during pipe manufacturing, It becomes difficult to manufacture a uniform tube having a regular shape by deforming in a direction in which the both ends are further expanded.

In addition, since the hollow spiral strip and the reinforcing strip are not bonded and integrated, even if a load such as earth pressure is applied to the hollow spiral strip to support the load by the reinforcing strip, However, there was a problem in that escape occurred in the spiral direction and the width direction and a sufficient reinforcing force could not be obtained.

The present invention provides a pressure-resistant synthetic resin pipe intended to solve such problems.

[Means for Solving the Problems]

In order to achieve the above object, the pressure resistant synthetic resin pipe of the present invention has a hollow spiral ridge (2) integrally formed on the outer periphery of a cylindrical pipe wall (1) as shown in the drawings corresponding to the embodiments. In the synthetic resin pipe formed as described above, a reinforcing strip plate (3) formed by continuously forming a mountain portion (3a) and a valley portion (3b) in the lengthwise direction inside the hollow spiral ridge (2), The reinforcing strips (3) are arranged in a continuous spiral with the width direction of the reinforcing spiral strips (3) oriented in the height direction of the hollow spiral ridges (2), and the inner and outer end surfaces of the reinforcing strips (3) are attached to the pipe wall (1). ) And the inner surface of the top of the hollow spiral ridge, and the mountain portion (3a) is integrally bonded to at least one of the opposing inner wall surfaces of the hollow spiral ridge (2). It is a thing.

[Action]

The reinforcing strip (3) is formed by continuously forming peaks (3a) and valleys (3b) in the length direction, and the width direction of the reinforcing strip (3) is made of synthetic resin pipe. In the height direction of the hollow spiral ridge (2), that is, in the vertical state, the hollow spiral ridge (2)
Since it is disposed inside, when spirally winding in the circumferential direction on the pipe wall (1) at the time of manufacturing the synthetic resin pipe, the inner peripheral side mountain portion (3a) and the valley portion (3b) are formed. While the outer peripheral peaks (3a) and troughs (3b) easily expand, depending on the diameter of the synthetic resin pipe to be manufactured, whether it has a small diameter or a large diameter. It can be flexed freely and can be smoothly and accurately arranged in the hollow spiral ridge (2).

Further, as described above, the reinforcing strip plate (3) is arranged in the hollow spiral ridge (2) with its width direction oriented in the height direction of the hollow spiral ridge (2) of the synthetic resin pipe. Moreover, since the inner and outer end surfaces thereof are brought into close contact with the outer peripheral surface of the pipe wall (1) and the inner surface of the top of the hollow spiral ridge (2), respectively, earth pressure and other loads act in the direction of compressing the pipe body. Also, the reinforcing strip plate (3) can firmly receive the external pressure and prevent the tubular body from being deformed.

Further, since the mountain portion (3a) of the reinforcing strip (3) is integrally bonded to the inner wall surface of the hollow spiral ridge (2), the hollow spiral ridge (2) made of synthetic resin is the reinforcing strip. (3) The shape is kept in a predetermined cross-sectional shape by the (3), and the height direction of the mountain portion (3a) of the reinforcing strip (3) is directed toward the width direction of the hollow spiral ridge (2). The hollow spiral ridge (2) can be strongly reinforced without bending, and the peaks (3a) and valleys (3b) can be easily bent and deformed according to the width dimension of the hollow ridge (2).
Even a large-diameter pressure-resistant synthetic resin pipe can be manufactured efficiently.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. (1) is a cylindrical tube wall made of synthetic resin such as polyethylene, the inner peripheral surface of which is formed as a flat surface (1a) having the same diameter over the entire length. A hollow spiral ridge (2) made of the same resin and having a rectangular cross section is integrally provided on the outer peripheral surface thereof.

A synthetic resin pipe in which a hollow spiral ridge (2) is integrally provided on the outer peripheral surface of such a cylindrical pipe wall (1) has, for example, a ridge having a half-section cross-section on the molding shaft. , The other half part is formed into a flat band part, and a synthetic resin band material having a constant width in a semi-molten state is supplied, and the ridge part is spiraled so as to be superposed on the flat band part of the preceding ridge part. It can be manufactured by winding it in a circular shape and integrally welding it, and in that case, a semi-molten state in which the spiral groove-shaped space between adjacent ridges is made of the same material between the tops of the ridges. A synthetic resin tube having an outer wall (1b) formed with a flat outer peripheral surface as shown in FIGS. 1 and 2 can also be obtained by spirally winding and integrating the synthetic resin band-shaped material. .

(3) is a reinforcing strip installed inside the hollow spiral ridge (2), which is a long metal flat strip having a uniform width over the entire length and a thickness of about 0.3 to 1.0 mm, or an appropriate thickness. It is made of a synthetic resin strip or a cardboard having a thickness, and has a mountain portion (3a) and a valley portion (3b) formed in a continuous corrugated shape in the length direction thereof. 3) The width direction of 3) is oriented in the height direction of the hollow ridge (2), and the hollow ridge (2) is continuously spirally arranged in the hollow ridge (2). Outer peripheral surface of the tube wall (1) and hollow spiral ridge (2)
Is integrally adhered or adhered to the inner surface of the top of the.

As shown in FIG. 6, such a reinforcing strip plate (3) can be formed by supplying a strip material such as a flat metal strip steel plate between a pair of upper and lower corrugating rolls (4) and (5). The cross-sectional shapes of the peaks (3a) and the valleys (3b) are not limited to the arc-shaped continuous corrugated shape as shown in the drawings, but may be U-shaped or triangular-shaped as shown in FIGS. It may have a shape.

As shown in FIG. 1, the hollow spiral ridge (2) is formed by continuously forming a small width hollow spiral ridge (2a) and a large hollow spiral ridge (2b), and these large and small hollow spiral ridges (2b) are formed. Spiral ridge (2a) (2
The reinforcing strip (3) may be provided in at least one of b), and as shown in FIG. 2, the reinforcing strip (3) is provided in the hollow spiral ridge (2) having the same sectional shape. You may keep the interior.

Further, as shown in FIGS. 3 to 5, a reinforcing strip plate (3) is formed on a synthetic resin pipe having a structure in which hollow spiral ridges (2) are formed on the outer peripheral surface of the pipe wall (1) at regular intervals. It is needless to say that the hollow spiral ridge (2) can be installed inside.

In each of the above-mentioned embodiments, the reinforcing strips (3) arranged in the hollow spiral ridges (2) have the height of the peaks (3a) between the opposing inner wall surfaces of the hollow spiral ridges (2). The top surfaces of the both peaks (3a) (3a) formed at equal intervals and bent in a continuous wavy shape are integrally brought into close contact with the facing inner wall surfaces of the hollow spiral ridge (2). As shown, the ridges (3) of the reinforcement strip (3)
The height of a) is made smaller than the dimension between the opposing inner wall surfaces of the hollow spiral ridge (2), and the mountain portion (3a) is integrated with one of the inner wall surfaces of the hollow spiral ridge (2). The reinforcing strips (3) may be provided in a spiral shape in close contact with each other, and two such reinforcing strips (3) are provided, as shown in FIG. You may keep them in close contact with each other.

In order to bring the reinforcing strip (3) into close contact with the inner wall surface of the hollow spiral ridge (2) integrally, a synthetic resin layer made of the same material as the pipe wall (1) is provided on both sides of the reinforcing strip (3). (6) is laminated, and the reinforcing strip (3) is included in the ridge (2) at the time of manufacturing the pipe and is supplied together with the semi-molten synthetic resin strip on the molding shaft, The synthetic resin layer (6) is once melted by the temperature of the synthetic resin strip, and then cured to be integrated.

Also, as shown in FIGS. 2 and 5, the ridges (3
The height of a) is made equal to the space between the inner wall surfaces of the hollow spiral ridge (2) facing each other, and the top surfaces of the mountain portions (3a) (3a) on both sides are made the inner wall surfaces of the hollow spiral ridge (2) facing each other. In the case of bringing them into close contact with each other, without providing the synthetic resin layer (6), the mountain portion of the synthetic resin pipe is made to bite into the opposing inner wall surface of the hollow spiral ridge (2) at the time of manufacturing the inner wall surface. It is also possible to form a concave portion in the concave portion and fix the peak portion top surface in the concave portion in a locked state.

The pressure-resistant synthetic resin pipe configured as described above has a pipe wall (1).
Since the inner peripheral surface of is formed as a flat surface (1a) over the entire length, when it is used as a fluid conduit, its flow can be performed smoothly and when underground wiring is provided. The work can be easily performed, and the desired pressure resistance can be maintained by the metal reinforcing strips (3) arranged in the hollow spiral ridges (2).

[Effect of device]

As described above, according to the pressure-resistant synthetic resin pipe of the present invention, in the synthetic resin pipe in which the hollow spiral ridge (2) is integrally formed on the outer periphery of the cylindrical pipe wall (1), the hollow spiral ridge is formed. Inside the (2), a reinforcing strip (3) formed by continuously forming peaks (3a) and valleys (3b) in the lengthwise direction is provided with a hollow spiral in the widthwise direction of the reinforcing strip (3). The ridges (2) are installed in a continuous spiral shape in a state of being oriented in the height direction, and the inner and outer end surfaces of the reinforcing strip (3) are the outer peripheral surface of the pipe wall (1) and the inner surface of the top of the hollow spiral ridge. And the mountain portion (3a) is integrally bonded to at least one of the opposing inner wall surfaces of the hollow spiral protrusion (2). The reinforcing strip (3) is formed by continuously forming peaks (3a) and valleys (3b) in the length direction, and the width direction of the reinforcing strip (3) is made of synthetic resin pipe. The height direction of the hollow spiral ridge (2),
That is, since the hollow spiral ridges (2) are arranged so as to be vertically oriented, the pipe wall (1) is produced during the production of the synthetic resin pipe.
When spirally winding up in the circumferential direction, the peaks (3
a) and the valleys (3b) contract, while the peaks (3
The a) and the trough (3b) are easily stretched to improve the flexibility, and therefore, whether it is a small diameter pipe or a large diameter pipe, it is made of synthetic resin while flexing freely according to its diameter. The pressure-resistant synthetic resin pipe, which can be accurately wound on the wall (1) and has a regular appearance, can be efficiently manufactured.

Further, as described above, the reinforcing strip plate (3) is arranged in the hollow spiral ridge (2) with its width direction oriented in the height direction of the hollow spiral ridge (2) of the synthetic resin pipe. Moreover, since the inner and outer end surfaces thereof are brought into close contact with the outer peripheral surface of the pipe wall (1) and the inner surface of the top of the hollow spiral ridge (2), respectively, the width direction of the reinforcing strip (3) is the hollow spiral ridge (2). ) Is arranged in the height direction, it is possible to easily set the width dimension of the reinforcing strip (3) according to the height of the hollow spiral ridge (2), and to manufacture the pressure-resistant synthetic resin pipe. Not only is this easy, but even if earth pressure or other loads act in the direction of compressing the tube, the reinforcing strip plate (3) firmly receives the external pressure and prevents the tube from compressive deformation. Is something that can be done.

Further, since the mountain portion (3a) of the reinforcing strip (3) is integrally bonded to the inner wall surface of the hollow spiral ridge (2), the hollow spiral ridge (2) made of synthetic resin is the reinforcing strip. Since the shape is maintained in a predetermined cross-sectional shape by (3) and the height direction of the mountain portion (3a) of the reinforcing strip (3) is directed toward the width direction of the hollow spiral ridge (2), The hollow spiral ridges (2) can be strongly reinforced without buckling of the reinforcing strip (3) and can be used for a long period of time.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a partially cutaway side view of Example 1, FIG. 2 is a partially cutaway vertical side view of Example 2, and FIG. Partially cutaway vertical side view, FIG. 3 (B) is a partial sectional view thereof, FIG. 4 (B) is a partial sectional view of a pipe in Example 4, and FIG. 4 (B) is a lateral sectional view thereof. ,
FIG. 5B is a sectional view of a part of the pipe in Example 5,
FIG. 6B is a cross-sectional view of the same, FIG. 6 is a simplified perspective view for explaining a method for manufacturing a reinforcing strip, and FIGS. 7 and 8 are partial plan views showing variations of the reinforcing strip. is there. (1) …… Synthetic resin pipe wall, (2) …… Hollow spiral ridge,
(3) …… Reinforcing strips, (3a) …… Mountains, (3b) …… Valleys.

Claims (1)

[Scope of utility model registration request] 1. A synthetic resin pipe in which a hollow spiral ridge (2) is integrally formed on the outer periphery of a cylindrical pipe wall (1), wherein a lengthwise direction is provided inside the hollow spiral ridge (2). At Yamabe (3a)
A reinforcing strip plate (3) formed by continuously forming
The reinforcing strips (3) are arranged in a continuous spiral with the width direction of the reinforcing spiral strips (3) oriented in the height direction of the hollow spiral ridges (2), and the inner and outer end surfaces of the reinforcing strips (3) are attached to the pipe wall (1). ) Is closely contacted with the outer peripheral surface of the hollow spiral ridge and the inner surface of the top of the hollow spiral ridge, and the ridges (3a) are integrally bonded to at least one of the opposing inner wall surfaces of the hollow spiral ridge (2). Withstand pressure synthetic resin pipe.