JPH0247350Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The metal buried synthetic resin pipe referred to in the invention is a pipe mainly used for air supply, water supply, cable protection pipes, etc. It can be used above ground or underground. It is a pressure-resistant synthetic resin pipe that may be used by being buried inside.

<Prior Art> In addition to drawn pipes, conventional metal pipes include metal pipes in which a band material is spirally wound, the side edges of which are butt-shaped, and the metal pipes are connected by welding or the like with a seam. On the other hand, in order to maintain corrosion resistance, there are pipes in which the inner circumferential surface of the pipe is coated with a synthetic resin material in addition to zinc coating. Also,
Synthetic resin pipes that do not use metal, such as so-called PVC pipes made only of hard vinyl chloride material, are also commonly used. Furthermore, synthetic resin pipes in which a synthetic resin band material is spirally wound and the side edges thereof are polymerized and fused are already widely used.

<Problems to be solved by the invention> However, the former type of metal drawn pipe requires a huge investment in equipment for manufacturing, and the latter type of seamed metal pipe requires a large amount of labor and expense for seam welding. .
In addition, whether zinc coating or synthetic resin coating is used, considerable equipment and costs are required, and it is technically difficult to uniformly apply corrosion-resistant treatment to the entire inner surface of a long pipe. It was accompanied by In addition, synthetic resin pipes, whose body is formed by sequentially winding synthetic resin strips in a spiral shape, are lighter and easier to transport than metal pipes, and do not require corrosion-resistant treatment. However, it has the disadvantage that the tensile load in the direction of the pipe axis is weak, it expands and contracts in the direction of the pipe axis when high-pressure fluid is passed through it, and its crushing strength against external pressure is low. Because it is missing,
It could not necessarily be said that it had sufficient strength for use with high-pressure fluids or for underground burial.

However, the present invention targets synthetic resin pipes using synthetic resin strips that tend to lack pressure resistance and stretch resistance, and solves the above-mentioned problems with these types of pipes. The objective is to obtain a synthetic resin pipe that has excellent crushing strength and excellent elongation resistance against internal pressure, and can be widely used for high-pressure fluids and for underground burial.

<Means for solving the problems> The present invention relates to a synthetic resin pipe that can achieve the above object extremely easily and reliably, and its configuration is shown in Figs. 1 to 4 corresponding to the embodiment. To explain using this, the synthetic resin pipe referred to in the present invention has a structure in which a synthetic resin band material is spirally wound and the side edges are polymerized and fused to form a series of pipe walls. In the synthetic resin pipe, a metal strip 3 having engaging portions 3A, 3A on both ends is placed in the synthetic resin pipe wall A, and both engaging portions 3A, 3A are attached to the pipe wall A.
The structure is such that it is spirally wound and buried so as to mutually engage with the engaging portions 3A, 3A of adjacent strip materials 3 in the longitudinal direction.

<Function> Synthetic resin pipes with such a structure are used by piping them inside the required buildings, factories, or underground, allowing the desired materials to flow through the pipes, and inserting and wiring electric wires, etc. .

<Examples> Examples of the present invention will be described below with reference to the drawings.

First, the materials used will be described. As the material for the metal strip 3, steel plates, stainless steel plates, iron plates, and other metal plates are arbitrarily selected depending on the purpose of the formed tube. The thickness of the plate is mainly 0.3 to 3 mm, and the width of the band is 20 to 300 mm or more.
They are selected appropriately, taking into account the diameter of the pipe to be formed, resistance to external pressure, resistance to internal pressure, purpose of use, location of use, etc.
Further, the metal strip material 3 is not limited to a flat strip material, and as shown in FIG. 13, it has many small holes 3b...
A punched metal material with holes formed therein may also be used. Alternatively, a band material made of metal wires knitted in a net shape may be used.

The synthetic resin strips 1 and 5 forming the pipe wall A are made of synthetic rubber, a mixture of synthetic resin and synthetic rubber, vinyl chloride, polyolefin such as polyethylene, polypropylene, or other synthetic resin materials. It is selected and used accordingly. Further, the hardness of the hard material, soft material, etc. is appropriately selected by adjusting the plasticizer and the like.

For example, in the case of a pipe used for transporting chemicals in a factory, etc., the synthetic resin strip 1 forming the inner layer 2 of the pipe is made of a chemical-resistant resin suitable for the chemicals used, and the outer layer 6 is made of a chemical-resistant resin suitable for the chemicals used. The synthetic resin strip material 5 to be formed may be made of a climate-resistant resin that does not easily deteriorate due to changes in external climate temperature, or even if the resin material is the same, it may be made of resin with different hardness on the inner and outer surfaces as necessary. For example, pipes with different resin properties on the inner and outer surfaces of the metal layer 4, such as pipes with different resin properties on the inner and outer surfaces of the pipe, or pipes with different wall thicknesses, etc. is also manufactured.

The diagrams shown in FIGS. 1 to 4 are diagrams showing one embodiment of the present invention, and the schematic structure shown in FIGS. 1 to 4 is a means for solving the above-mentioned problems. As explained in the section above, but to explain further, a synthetic resin strip material 1 extruded from a molding machine (not shown) at a temperature above the softening point and below the melting point.
is wound spirally on a tube-forming mandrel so that one side edge overlaps, and the upper surface is pressed with a pressure roller to fuse and bond the overlapping portions, thereby forming a molded material on the outer circumferential surface in the axial direction. A metal strip 3 having a cylindrical inner layer 2 having a spiral waveform surface 2A along the cylindrical inner layer 2, and having engaging portions 3A, 3A at both end edges and having a cross-sectional shape in close contact with the wavy surface 2A of the cylindrical inner layer 2. is spirally wound onto the outer surface of the inner layer 2 so that the engaging portion 2A engages with the outer surface of the inner layer 2, thereby forming a spiral cylindrical metal layer 4. In the embodiment shown in the figure, the engaging portions 3A, 3A of the metal strip 3 are formed to protrude in opposite directions at both ends of the linear strip. 3A (the left side in the figure) is arranged and formed so as to be in contact with the wave-shaped rising surfaces 2a, 2a on the outer circumferential surface of the inner layer. Furthermore, in the same way as the cylinder inner layer 2 was molded, a synthetic resin band material 5 extruded from another molding machine (not shown) was placed on the outer peripheral surface of the metal layer 4 so that one side edge thereof overlapped. The tube is wound spirally so as to be fused to form an outer cylinder layer 6, thereby constructing a metal-embedded synthetic resin tube. In the embodiment shown in the figure, the synthetic resin strip 5 serving as the outer layer 6 is provided with a hollow convex strip 5A on its upper surface, and the completed metal-embedded synthetic resin pipe A is provided with a hollow protrusion 5A on its outer peripheral surface. It becomes a corrugated pipe with a spiral central protrusion 5A.

Incidentally, the protruding strip 5A does not necessarily have to be rectangular, but can be formed into a semicircular shape as shown in FIG. 9, or various other shapes as desired. Further, the protruding strip 5A does not necessarily have to be hollow, and may be solid. Furthermore, it goes without saying that, depending on the case, it may be formed on a flat outer surface without the protruding stripes 5A as shown in FIG.

In addition, in the embodiment drawings, including the embodiment drawings to be described later, the synthetic resin pipe wall A is illustrated as having a thick wall for convenience of explanation, but in reality, it is not necessary to form it as thick as that shown in the drawings. , it goes without saying that the thickness may be approximately the same as that of the buried metal strip 3.

5 to 8 are views showing another embodiment, in which the shapes of the engaging portions 3A, 3A of the metal strip 3 are changed. The mating portion 3A forms a protrusion rising upward, and the right engaging portion 3A is formed in an inverted U-shape with a downward recess into which the left protrusion is fitted from above. Then, when the metal strip 3 is wound onto the tube inner layer 2, the two are engaged (see Fig. 6), and then a presser roller is used to push the engaged portion diagonally downward (in the direction of arrow a). The end edges of the metal strip 3 are firmly connected by pushing them down. Thereafter, the tube A is formed by winding the outer layer strip material 5 to form the cylinder outer layer 6 by the same means as in the first embodiment.

Note that the engagement and connection position of one side edge of the metal strip 3 must be at the same position as the connection and fusion portion of the synthetic resin strips 1 and 5, as shown in the above two embodiments. For example, as shown in FIG. 12, the connecting portions may be placed at positions where they do not coincide with each other in the tube axis direction.

Furthermore, even when the synthetic resin strips 1 and 5 constituting the inner cylinder layer 2 and the outer layer 6 are wound into a cylinder, they do not necessarily have to be wound so that one edge thereof overlaps, for example. Figure 11 and the above 12th
As shown in the figure, the adjacent end surfaces may be brought into abutment and fusion-bonded.
Even in this case, since the engaging portions 3A, 3A of the metal strip 3 interposed in the middle are strongly connected, the tensile strength of the pipe as a whole can be sufficiently ensured.

Although the embodiments considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the structure of these embodiments, and the present invention is not necessarily limited to the structure of these embodiments. It can be implemented with appropriate modification within the scope of achieving the following effects.

<Effects of the invention> As detailed above in the description of the embodiments and as described in the section of means for solving the problems, the present invention provides a metal layer 4 for forming the metal layer 4 in the synthetic resin tube wall A. Engaging portions 3 are attached to both side edges of the strip material 3.
A, 3A are formed and these engaging parts 3A, 3A are buried so as to engage with each other, so the tensile strength in the axial direction of the pipe is dramatically improved compared to conventional synthetic resin spiral pipes. At the same time, it is possible to significantly increase the internal pressure resistance and external pressure resistance. Therefore, even if thin metal materials are used, sufficient strength can be maintained, and while the overall weight is lightweight, it is also possible to significantly increase the resistance to internal pressure and external pressure. It is possible to obtain a durable metal pipe that can be safely used as a pipe or underground pipe. Further, it is also possible to easily obtain resin-clad tubes made of different materials on the inner and outer sides of the tube, or resin-clad tubes with different hardnesses, thicknesses, etc. Furthermore, it has various remarkable features, such as the ability to extremely easily produce tubes with different diameters and helical angles, and pressure-resistant tubes having ribs on the inner and outer surfaces.

[Brief explanation of the drawing]

Figures 1 to 4 are views showing one embodiment of the present invention, in which Figure 1 is a partially cutaway front view of a tube, Figure 2 is an enlarged sectional view showing the inner layer of the cylinder, and Figure 3 is the inner layer of the cylinder. FIG. 4 is an enlarged sectional view showing the main parts of the tube, and FIGS. 5 to 7 are views showing the manufacturing process of other embodiments. FIGS. 8 to 12 are enlarged cross-sectional views of the tube showing still other embodiments, respectively, and FIGS.
FIG. 3 is a perspective view of a main part showing an example of a metal strip material. In the figure, 1 and 5 are synthetic resin strips, 3 is a metal strip, 3A and 3A are engaging portions, and A is a tube wall.

Claims (1)

[Claims for Utility Model Registration] A synthetic resin pipe having a structure in which a synthetic resin band material is spirally wound and the side edges thereof are polymerized and fused to form a series of pipe walls, In the synthetic resin pipe wall A, engaging portions 3A, 3 are provided at both end edges.
The metal strip 3 having A has both engaging portions 3A,
A metal-embedded synthetic resin pipe in which 3A is spirally wound and buried so that it mutually engages with engaging portions 3A, 3A of adjacent strips 3 in the longitudinal direction of the pipe wall A. The metal-embedded synthetic resin pipe according to claim 1, wherein the metal strip 3 is a steel plate. The metal-embedded synthetic resin pipe according to claim 1, wherein the metal strip 3 is a stainless steel plate. The metal-embedded synthetic resin pipe according to claim 1, wherein the metal strip 3 is a punched metal having a large number of small holes 3a formed therethrough. The metal-embedded synthetic resin pipe according to claim 1, wherein the synthetic resin band material is an olefin-based or vinyl chloride-based synthetic resin material. The metal-embedded synthetic resin pipe according to claim 1, wherein the synthetic resin strip is made of a synthetic rubber-based resin material. The metal-embedded synthetic resin pipe according to claim 1, wherein the pipe wall A is formed into a substantially smooth cylindrical surface both inside and outside. A metal-embedded synthetic resin pipe according to claim 1, wherein the pipe wall A is provided with a hollow convex strip 5A wound spirally on the outer peripheral surface thereof.