JP5403533B2 - Synthetic resin pipe, manufacturing method and connecting method thereof - Google Patents

Description

The present invention relates to a rigid synthetic resin pipe that is used as a conduit for hot water or other fluid or gas, and is constructed by heat welding, a manufacturing method thereof, and a connection method using the synthetic resin pipe.
Specifically, the present invention relates to a synthetic resin pipe in which a pipe body is formed by laminating a plurality of layers and a reinforcing layer is formed by spirally winding a reinforcing material between the plurality of layers, and a manufacturing method and a connection method thereof.

  Conventionally, as this type of synthetic resin pipe, an inner layer pipe composed of an innermost layer made of polyethylene and an outermost layer having the highest melt index, and a strip-like stretched polyolefin resin sheet on the outer peripheral surface of the inner layer pipe are inclined at respective angles. Of the inner layer tube having a two-layered reinforcing layer wound spirally so as to be opposite to each other and an outer layer made of polyethylene laminated on the reinforcing layer and wound with a stretched polyolefin resin sheet The surface is heated in an infrared furnace to fuse the resin sheet to the inner layer pipe. At this time, the resin in the inner layer pipe is filled in the sheet gap (gap between the sheet end faces), and then the outer layer is extruded and coated. There is a composite high-pressure pipe that prevents water from entering from the end face of the pipe between the inner layer pipe and the reinforcing layer and between the reinforcing layer and the outer layer (for example, see Patent Document 1).

Japanese Patent No. 4076440 (pages 18-21, FIGS. 3, 4 and 9)

However, in such a conventional synthetic resin pipe, the two reinforcing layers are in contact with each other between the inner layer and the outer layer, but there is no place where the inner layer and the outer layer are in direct contact with each other. There was a problem that there was a possibility of peeling from between the two reinforcing layers with a rapid pressure change in the pipe.
Furthermore, since the two reinforcing layers are in direct contact with each other, every time an external force such as bending acts on the entire pipe, there is a problem that friction may occur between these reinforcing layers, causing displacement or damage. there were.
In addition, the surface of the inner layer tube around which the stretched polyolefin resin sheet is wound is heated in an infrared furnace to fuse the resin sheet to the inner layer tube. At this time, the resin in the inner layer tube is filled in the sheet gap, Since the outer layer is extrusion-coated, the stretched polyolefin resin sheet is easily affected by heat, which causes the stretched resin sheet to shrink and the physical properties to easily deteriorate, thereby reducing the pressure resistance and durability of the entire pipe. There was also a problem.

The first invention of the present invention aims to increase the adhesive strength of a plurality of layers.
In addition to the objects of the first invention or the second invention, the third invention aims to flatten the inner peripheral surface and the outer peripheral surface of the pipe body.
In addition to the objects of the first invention , the second invention, or the third invention , the fourth invention aims to minimize heat transmission to the spiral reinforcing material.
In addition to the object of the second invention , the fifth invention aims to prevent the occurrence of a weeping phenomenon and blister breakage due to water intrusion from the pipe end face in the pipe connection state.

In order to achieve the above-described object, the first invention of the present invention is that a plurality of layers are laminated to form a rigid pipe body, and a reinforcing material is spirally wound between the plurality of layers. A synthetic resin pipe in which a reinforcing layer is formed, wherein an inner layer and an outer layer are formed of a hard resin as the plurality of layers , and a plurality of reinforcing wires extending linearly in the axial direction of the pipe body are respectively spaced at predetermined intervals in the circumferential direction. the adhesive layer is formed between the inner layer and the outer layer is embedded in each, between the adhesive layer and the inner layer and the outer layer, the inclination angle of the respective helical reinforcing member as the reinforcing material in the opposite direction The reinforcing layer is formed along the inner peripheral surface and the outer peripheral surface of the adhesive layer by winding in a spiral manner.
According to a second aspect of the present invention, in the configuration of the first aspect, the pipe main body is formed by using the inner layer, the reinforcing wire, the outer layer, the adhesive layer, and the helical reinforcing material in a similar synthetic resin. It is characterized by adding.
According to a third invention, in the configuration of the first invention or the second invention, the inner layer and the outer layer are formed of a thermoplastic resin, and a thermoplastic resin having higher fluidity than the thermoplastic resin of the inner layer and the outer layer. The structure in which the adhesive layer is formed is added.
The fourth invention is wound upon producing synthetic resin pipe as described above, the cooling after the adhesive layer is laminated, spiral the spiral reinforcing member along the outer peripheral surface of the adhesive layer after the cooling step It is characterized by that.
Fifth invention, when connecting a synthetic resin pipe as described above, the axis of said pipe body in which the spiral reinforcing member wherein the inner layer and the reinforcing wire member said outer layer and said adhesive layer is formed by syngeneic synthetic resin The end portions in the direction are heated and melted, and the end surfaces are brought into contact with each other so that the heated and melted pipe main body is in a straight line, and are heat-welded.

First invention of the present invention, an adhesive layer between the inner and outer layers, between the inner and outer layers adhesive layer, the spiral reinforcement inclination angle of each are opposite as a reinforcing material wound in helically so, by respectively forming the reinforcement layer along the inner and outer peripheral surfaces of the contact adhesive layer, the outer peripheral surface of the inner layer and the inner peripheral surface of the adhesive layer, a spiral reinforcing member with the through spiral gap formed in direct contact secured to, the inner peripheral surface of the outer layer and the outer peripheral surface of the adhesive layer is in direct contact with fixing through the spiral gap of the spiral reinforcing member The
Therefore, the adhesive strength of a plurality of layers can be increased.
As a result, the two reinforcing layers contact each other between the inner layer and the outer layer, but the layers peel off due to a sudden pressure change in the pipe, compared to the conventional one where the inner layer and the outer layer do not have direct contact. It becomes difficult to improve pressure resistance.
Furthermore, the reinforcing layer between the two-layer structure is compared with the conventional direct contact, the reinforcing layer of the two layers are arranged to sandwich the adhesive layer is between spiral reinforcement not touch, such as bending the entire pipe Even if an external force is applied, it is possible to prevent damage such as positional displacement and thread breakage of the spiral reinforcing material.

The third invention is, in addition to the effect of the first invention or the second invention, the inner and outer layers together to form a thermoplastic resin, contact with high thermoplastic resin fluidity than the thermoplastic resin of the inner and outer layers By forming the adhesion layer, the highly fluid thermoplastic resin of the adhesive layer smoothly enters the spiral gaps of the spiral reinforcement material, and the difference in thickness dimension depending on the presence or absence of these spiral reinforcement materials. Since it absorbs, unevenness does not occur on the inner peripheral surface of the inner layer and the outer peripheral surface of the outer layer .
Therefore, the inner peripheral surface and the outer peripheral surface of the pipe body can be flattened.

According to a fourth aspect of the present invention, when the synthetic resin pipe described above is manufactured, the adhesive layer is laminated and then cooled, and after this cooling step, the spiral reinforcing material is spirally wound along the outer peripheral surface of the adhesive layer. Thus, the heat generated when the adhesive layer is coated and laminated is not easily transmitted to the spiral reinforcing material on the inner periphery of the adhesive layer, and is also difficult to transmit to the spiral reinforcing material on the outer periphery of the adhesive layer.
Therefore, heat transmission to the spiral reinforcement can be minimized.
As a result, the shrinkage and deterioration of physical properties of the stretched spiral reinforcing material can be suppressed compared to the conventional one in which the outer layer is extruded and coated after heating and fusing the surface of the inner layer tube around which the stretched resin sheet is wound. Thus, the pressure resistance and durability of the entire vibrator can be improved.

In the fifth invention, when connecting the above-described synthetic resin pipe, the axial end of the pipe body in which the inner layer, the reinforcing wire, the outer layer, the adhesive layer, and the helical reinforcing material are formed of the same type of synthetic resin is heated and melted. Then, the inner layer, the reinforcing wire, the outer layer, the adhesive layer, and the spiral reinforcing member are integrated with no gap by abutting each end face so that the heated and melted pipe body is in a straight line and press-welding each other. To be welded.
Therefore, it is possible to prevent the occurrence of weeping phenomenon and blister breakage due to water intrusion from the pipe end face in the pipe connection state.

  In the embodiment of the synthetic resin pipe A of the present invention, as shown in FIG. 1, an inner layer and an outer layer are provided as a plurality of layers 1 and 2 made of a thermoplastic resin, and an adhesive layer is provided as an intermediate layer between the inner layer 1 and the outer layer 2. 3 and a spiral reinforcing material 4a as a reinforcing material is spirally wound between each of the inner layer 1 and the outer layer 2 and the adhesive layer 3 so that the respective inclination angles are opposite to each other. Thus, the reinforcing layers 4 and 5 are formed along the inner peripheral surface and the outer peripheral surface of the adhesive layer 3, respectively.

The inner layer 1, the outer layer 2 and the adhesive layer 3 are formed of an olefin resin such as polypropylene, for example, and are integrally laminated to form a pipe body A '. The axial end of the pipe body A' is By heating with a heating means such as a heater, it is thermally welded to the connection partner.
In particular, it is preferable to use a thermoplastic resin having higher fluidity (melt index) than the thermoplastic resin used for the inner layer 1 and the outer layer 2 for the adhesive layer 3.

The pipe body A ′ is manufactured by first extruding the inner layer 1, spirally winding the spiral reinforcing material 4 a along the outer peripheral surface 1 a of the inner layer 1, and then extruding the adhesive layer 3 on the outer side. Then, after this lamination, they are immersed in a cooling water tank and cooled.
After this cooling step, the spiral reinforcing material 5a is spirally wound along the outer peripheral surface 3a of the adhesive layer 3 so that the inclination angle is opposite to that of the spiral reinforcing material 4a. After cooling, the outer layer 2 is finally extruded and laminated.

Although not shown, an innermost layer made of a material suitable for the fluid or gas passing through the pipe body A ′ is provided inside the inner layer 1 as necessary, or an outermost layer made of a protective material is placed outside the outer layer 2. It is also possible to provide an outer layer.
Further, between the inner layer 1 and the innermost layer, between the outer layer 2 and the outermost layer, or inside the inner layer 1, the outer layer 2 and the adhesive layer 3, a reinforcing wire made of a synthetic resin similar to these is attached to the pipe body A ′. It is also possible to arrange it over substantially the entire length in the axial direction.

  The spiral reinforcing members 4a and 5a are yarns such as monofilaments (monofilaments) formed from the same olefin-based resin as the inner layer 1, the outer layer 2, and the adhesive layer 3, and reinforcing fibers. For example, it is preferable to wind a thick monofilament (stretched monofilament) spirally because the pipe body A ′ can be easily cut and reduced in weight while being excellent in rigidity.

As another example, in addition to spirally winding multifilaments knitted with thin monofilaments, whether to form a hollow cylindrical uniform net by spirally braiding in the circumferential direction of the pipe body A ′ Alternatively, it is also possible to add and arrange a knitted braid or the like that is knitted into a uniform shape of a hollow cylinder.
Furthermore, it is also possible to use flat yarn (or tape yarn) made of tape-like yarn instead of drawn monofilament or multifilament. In this case, the thickness of the reinforcing wire 3 is reduced, and the pipe There is an advantage that the thickness of the entire body A ′ can be reduced.

  Then, as an embodiment of the connection method (pipe connection structure) using the synthetic resin pipe A of the present invention, as shown in FIG. 2, when two synthetic resin pipes A are directly connected, each pipe body The end portions in the axial direction of A ′ are heated, the end faces thereof are brought into contact with each other, moderately pressurized and pressed, and thermally welded.

When the synthetic resin pipe A is connected using a joint pipe B described later, the axial end of the synthetic resin pipe A is heated and pressed against the joint pipe B as shown in FIGS. And heat-welded.
This pipe connection structure includes the above-described synthetic resin pipe A and a joint pipe B that is fitted to the axial end A1 of the synthetic resin pipe A, and the axial end A1 and the joint pipe of the synthetic resin pipe A. The surface facing B is melted by a heating means (not shown), and the melted facing surfaces are welded to each other.

  As a specific example, the inner diameter of the joint pipe B is formed to be equal to or smaller than the outer diameter of the axial end A1 of the synthetic resin pipe A, and the outer peripheral surface of the axial end A1 of the synthetic resin pipe A After heating A2 and the inner peripheral surface B1 of the joint pipe B, the synthetic resin pipe A is pushed into the joint pipe B, so that the joint inner peripheral face B1 and the pipe outer peripheral face A2 are pressed against each other and thermally welded. ing.

The joint pipe B is formed of a thermoplastic resin similar to the layers 1 and 2 of the synthetic resin pipe A, specifically an olefin resin such as polypropylene, and has openings corresponding to the number of the synthetic resin pipes A to be connected. For example, it is integrally formed in a straight pipe or a T-shaped pipe.
In the illustrated example, a case is shown in which two openings of the joint pipe B are opened in a straight line, and two synthetic resin pipes A are respectively pushed into and connected to the openings.

Further, if necessary, a step B2 where the axial end surface A3 of the synthetic resin pipe A inserted into the inner peripheral surface B1 of the opening to which the axial end A1 of the synthetic resin pipe A is connected is in the circumferential direction. It is preferable to integrally mold so as to protrude in a ring shape.
In this case, when the synthetic resin pipe A is pushed into the joint pipe B, the joint inner peripheral surface B1 and the pipe outer peripheral surface A2 are pressed against each other, and at the same time, the step B2 in the joint pipe B and the axial front end surface of the synthetic resin pipe A A3 is press-contacted, and these press-contact portions are welded respectively.

By the way, as shown in FIGS. 6 (a) and 6 (b), the synthetic resin pipe A is pushed into the opening of the joint pipe B as described above, and the opposing pipe outer peripheral surface A2 and the joint inner peripheral surface B1 are pressed, When the melted resin R overflows from these opposing surfaces, the molten resin R going from the pressure contact portion to the inside of the synthetic resin pipe A rises from the inner peripheral surface A4 of the synthetic resin pipe A to the inside of the pipe and flows out as it is. It protrudes in a ring and hardens.
On the other hand, the molten resin R from the pressure contact portion to the end surface B3 of the joint pipe B along the pipe outer peripheral surface A2 rises out of the pipe B from the end surface B3 of the joint pipe B, and protrudes in an annular shape as it is. Harden.
As a result, the annular resin R that has risen and hardened to the inner side of the pipe inner peripheral surface A4 may partially squeeze the flow path so that a predetermined flow rate cannot be ensured. The ring-shaped resin R which is raised and hardened may deteriorate the appearance.

Therefore, in order to solve such problems, in the pipe connection method (pipe connection structure) of the present invention, the axial end portion A1 of the synthetic resin pipe A, the joint pipe B, and the press-contact portion enter the inside of the synthetic resin pipe A. A flow restricting means C for suppressing the flow of the molten resin R is provided.
As the flow restricting means C, as shown in FIGS. 3A and 3B, the connecting portion between the axial end A1 of the synthetic resin pipe A and the joint pipe B is sealed with a sealing cover C1. It is preferable that the molten resin R overflowing as the synthetic resin pipe A is pushed and pressed by being attached so as to cover from the inside is guided and cured toward the end surface B3 of the joint pipe B along the pipe outer peripheral surface A2. .

  As another example, as shown in FIGS. 4A, 4B and 5A, 5B, the storage portions C2, C3 are provided at the pressure contact portion between the axial end A1 of the synthetic resin pipe A and the joint pipe B. By forming the molten resin R, the molten resin R that overflows as the synthetic resin pipe A is pushed and pressed can be poured into the storage means C2 and C3 to be cured.

Further, as an olefin resin such as polypropylene constituting the plurality of layers 1 and 2 and the reinforcing wire 3, in the pipe connection structure, when the axial end faces of the synthetic resin pipe A are butted and welded, It can be molded with either an olefin resin or a hard olefin resin, but when a plurality of synthetic resin pipes A are heat-welded via the joint pipe B, they are synthesized with respect to the opening of the joint pipe B. Since it is necessary to insert the resin pipe A, it is preferable to mold the resin pipe A with a somewhat hard olefin resin.
Embodiments of the present invention will be described below with reference to the drawings.

  In the first embodiment, as shown in FIG. 1, the above-described synthetic resin pipe A is similar to the spiral reinforcing members 4a and 5a along the outer peripheral surface 1a of the inner layer 1 after the inner layer 1 is extruded. A plurality of reinforcing wires 6 such as thick monofilaments (stretched monofilaments) made of synthetic resin and extending linearly in the axial direction are arranged in the circumferential direction at appropriate intervals, and are pressed from the outside to form the reinforcing wires 6 as inner layers 1. The reinforcing layer 4 (helical reinforcing material 4a), the adhesive layer 3, the reinforcing layer 5 (helical reinforcing material 5a) and the outer layer 2 are laminated in order on the outside, thereby integrating them. The case where the pipe body A ′ is formed is shown.

  Therefore, in Example 1 shown in FIG. 1, the outer peripheral surface 1a of the inner layer 1 and the inner peripheral surface of the adhesive layer 3 are fixed in direct contact with each other through a spiral gap formed in the spiral reinforcing material 4a. At the same time, the outer peripheral surface 3a of the adhesive layer 3 and the inner peripheral surface of the outer layer 2 are fixed in direct contact with each other through the spiral gap of the spiral reinforcing material 5a.

Thereby, the adhesive strength between the inner layer 1 and the outer layer 2 is increased through the adhesive layer 3, and it is possible to prevent the layers from being separated due to a sudden pressure change in the pipe.
Further, since the spiral reinforcing members 4a and 5a of the reinforcing layers 4 and 5 are arranged with the adhesive layer 3 interposed therebetween, and the spiral reinforcing members 4a and 5a are not in direct contact with each other, the pitch deviation of the spiral reinforcing members 4a and 5a is not achieved. And thread breakage does not occur.

In particular, when a thermoplastic resin having a higher fluidity (melt index) than the thermoplastic resin used for the inner layer 1 and the outer layer 2 is used as the adhesive layer 3, the spiral reinforcing materials 4a and 5a have a spiral gap. In order to absorb the difference in thickness due to the presence or absence of the spiral reinforcing materials 4a and 5a, the high fluidity thermoplastic resin of the adhesive layer 3 is smoothly penetrated, so that the inner peripheral surface of the inner layer 1 and the outer layer 2 Unevenness does not occur on the outer peripheral surface.
Thereby, the inner peripheral surface and outer peripheral surface of pipe main body A 'can be made flat.

In the manufacturing process of the pipe body A ′, after the adhesive layer 3 is laminated, the adhesive layer 3 and the spiral reinforcing material 4a wound spirally along the inner peripheral surface of the adhesive layer 3 are cooled. After this cooling step, the spiral reinforcing material 5a is spirally wound along the outer peripheral surface of the adhesive layer 3, so that the heat generated when the adhesive layer 3 is coated and laminated becomes a spiral on the inner periphery of the adhesive layer 3. It becomes difficult to transmit to the reinforcing material 4a and also to the helical reinforcing material 5a on the outer periphery of the adhesive layer 3.
Thereby, heat transmission to the spiral reinforcing members 4a and 5a can be suppressed to the minimum, and the thermal contraction and thermal deterioration of the spiral reinforcing members 4a and 5a can be surely suppressed.

Next, a connection example of such a synthetic resin pipe A will be described.
As shown in FIG. 2, first, only the axial ends of the pipe bodies A ′ are heated by a heating means (not shown) such as a heater, and then the end faces are set so that the pipe bodies A ′ are in a straight line. When they are butted against each other, the inner layer 1, the outer layer 2, the adhesive layer 3, the axial ends of the spiral reinforcing members 4a and 5a and the reinforcing wire 6 are melted and united, and these spiral reinforcing members 4a 5a and the reinforcing wire 6 are heat-welded to the inner layer 1, the outer layer 2 and the adhesive layer 3.

  Thereby, even if the pipe body A ′ is bent or deformed in particular, the spiral reinforcing members 4a and 5a and the reinforcing wire 6 do not move out of the inner layer 1 and between the layers, and as a result, Even when the environment in which the pipe body A ′ is used becomes a high temperature atmosphere, the pipe body A ′ is prevented from extending in the axial direction or bent in an arcuate shape, and the linear strength of the pipe body A ′ is maintained. Furthermore, an excessive force is not applied to the connecting portion of each pipe body A ′.

Further, since the inner layer 1, the outer layer 2, the adhesive layer 3, the spiral reinforcing members 4a and 5a, and the reinforcing wire 6 are the same type of olefin resin, the pipe body A 'can be disposed and recycled without being decomposed. It is.
In the case of the illustrated example, an example is shown in which the molten resin R flowing out from the axial end faces of each pipe body A ′ rises to the inside of the inner layer 1 and the outside of the outer layer 2 and protrudes in an annular shape and hardens. However, as described above, it is preferable that at least the inner layer 1 is annularly raised and not hardened.

  As shown in FIGS. 3 (a) and 3 (b), the second embodiment is connected through the joint pipe B as a pipe connection method using the synthetic resin pipe A. The case where the sealing cover C1 as the flow restricting means C is attached from the inside of the synthetic resin pipe A to the portion where the directional front end surface A3 and the step B2 in the joint B abut is shown.

  The sealing cover C1 is formed of a synthetic resin or a metal having a higher melting temperature than an olefin resin such as polypropylene constituting the synthetic resin pipe A and the joint B, and the axial direction of these synthetic resin pipes A as required. It is preferable to project a clamping portion C1 ′ that is sandwiched between the front end surface A3 and the stepped portion B2 in the joint B.

Next, such a pipe connecting method will be described in detail in the order of steps.
First, as shown by a two-dot chain line in FIG. 3A, the outer peripheral surface A2 and the front end surface A3 of the axial end A1 of the synthetic resin pipe A, and the inner peripheral surface B1 of the joint pipe B opposed to them are Each is heated by, for example, contacting a heating means (not shown) such as a heater.

When the pipe outer peripheral surface A2 and the pipe front end surface A3 and the surface portion of the joint inner peripheral surface B1 reach a meltable temperature, the sealing cover C1 is sandwiched between the synthetic resin pipe A and the joint pipe B.
Thereafter, as shown in FIG. 3 (b), the heated pipe outer peripheral surface A2 is inserted along the heated joint inner peripheral surface B1, thereby bringing them into pressure contact with each other, and the pipe front end surface A3 is connected to the joint. It strikes against the step B2 in the tube B.

As a result, the molten resin R flowing out with the pressing of the synthetic resin pipe A and the pressure contact between the pipe outer peripheral surface A2 and the joint inner peripheral surface B1 has a gap between the pipe front end surface A3 and the joint means B2 being sealed with the sealing cover C1. Therefore, it does not flow out from the pipe inner peripheral surface A4 side, all of which is guided along the pipe outer peripheral surface A2 toward the end surface B3 of the joint pipe B, and then flows out and protrudes in an annular shape outward. Harden.
Therefore, Example 2 shown in FIGS. 3A and 3B can prevent the molten resin R from rising and curing on the pipe inner peripheral surface A4 at the pipe connection portion between the synthetic resin pipe A and the joint pipe B, Since the flow path is not restricted, a predetermined flow rate can be secured.

  As shown in FIGS. 4A and 4B, the third embodiment replaces the sealing cover C1 of the second embodiment shown in FIGS. 3A and 3B with a step B2 in the joint B. The storage portion C2 is recessed as the flow restricting means C so as to face the pipe inner peripheral surface A3, so that the molten resin R flowing out as the synthetic resin pipe A is pushed and pressed is supplied to the storage portion. The configuration for pouring into C2 and curing is different from the second embodiment shown in FIG. 2, and the other configuration is the same as the second embodiment shown in FIG.

  The reservoir C2 is preferably formed in an annular shape over the entire circumference in the circumferential direction of the end surface of the stepped portion B2, and can be expanded toward the joint inner circumferential surface B1 in order to increase its capacity.

Accordingly, the third embodiment shown in FIG. 4 can obtain the same operation and effect as the second embodiment described above. In addition, since the sealing cover C1 is not further required as in the second embodiment, the connection work is not necessary. In addition to being easy, there is an advantage that the number of parts can be reduced correspondingly and the cost can be reduced.
In addition, since part or most of the molten resin R flowing out as the synthetic resin pipe A is pushed in and pressed against the outer peripheral surface A2 of the pipe and the inner peripheral surface B1 of the joint flows into the storage portion C2, the outer peripheral surface A2 extends along the pipe. The amount of the molten resin R toward the end surface B3 of the joint pipe B is reduced, and as a result, the resin R that rises outward from the outer peripheral surface A2 of the pipe and hardens is greatly reduced and becomes inconspicuous. There are also advantages.

  As shown in FIGS. 5 (a) and 5 (b), the fourth embodiment replaces the storage section C2 of the third embodiment shown in FIGS. 4 (a) and 4 (b) with a storage section C3 as the flow regulating means C. The configuration in which the molten resin R that flows out as the synthetic resin pipe A is pushed and pressed by being recessed so as to face the pipe front end surface A3 is poured into the storage portion C3 and cured is shown in FIG. Unlike the third embodiment shown in FIG. 4, the rest of the configuration is the same as that of the third embodiment shown in FIG.

The storage portion C3 is inclined linearly or curvedly so that the pipe outer peripheral surface A2 side is most concave on the pipe front end surface A3 as shown in the illustrated example, while preventing the outflow to the pipe inner peripheral surface A4 side. It is preferable to increase.
As another example, it is also possible to form an annular storage portion C3 on the pipe front end surface A3 perpendicular to the axial direction of the synthetic resin pipe A.

  Therefore, the fourth embodiment shown in FIG. 5 can obtain the same operation and effect as the third embodiment described above, and in addition, the pipe front end surface A3 is inclined so that the capacity of the storage portion C3 increases as in the illustrated example. In this case, most of the molten resin R flowing out due to the pressing of the synthetic resin pipe A and the pressure contact between the pipe outer peripheral surface A2 and the joint inner peripheral surface B1 flows into the storage portion C3, and therefore, along the pipe outer peripheral surface A2. The amount flowing out toward the end surface B3 of the joint pipe B is remarkably reduced, thereby eliminating the resin R that rises and hardens outward from the outer peripheral surface A2 of the pipe, and has the advantage that the appearance is improved.

In Example 1 of the synthetic resin pipe A described above, after the inner layer 1 is extruded, a plurality of reinforcing wire members 6 are arranged in the circumferential direction at appropriate intervals, respectively, and pressed from the outside to form each reinforcing wire member 6 in the inner layer 1. However, the present invention is not limited to this, and the reinforcing wire 6 may not be disposed inside the inner layer 1.
Furthermore, in the second to fourth embodiments of the pipe connecting method described above, the axial direction of the synthetic resin pipe A inserted into the inner peripheral surface B1 of the opening to which the axial end A1 of the synthetic resin pipe A is connected. The step portion B2 with which the end surface A3 abuts is formed to protrude, but the present invention is not limited to this, and without the step portion B2, the axial end surfaces A3 of the two synthetic resin pipes A to be connected abut each other. You may make it weld the press-contact part of tip surface A3, and the press-contact part of joint internal peripheral surface B1 and pipe outer peripheral surface A2.

It is a partially notched perspective view which shows one Example of the synthetic resin pipe of this invention. It is a longitudinal cross-sectional view which shows the example of a connection of the synthetic resin pipe of this invention. It is a longitudinal cross-sectional view which shows an example of the pipe connection method using the synthetic resin pipe of this invention, (a) has shown the state before a connection, (b) has shown the state after a connection. It is a longitudinal cross-sectional view which shows the other example of the pipe connection method, (a) has shown the state before a connection, (b) has shown the state after a connection. It is a longitudinal cross-sectional view which shows the other example of the pipe connection method, (a) has shown the state before a connection, (b) has shown the state after a connection. It is a longitudinal cross-sectional view which shows an example of the conventional pipe connection method, (a) has shown the state before a connection, (b) has shown the state after a connection.

Explanation of symbols

A Synthetic resin pipe A 'Pipe body 1 Inner layer 1a Outer peripheral surface 2 Outer layer 3 Adhesive layer 3a Outer peripheral surface 4,5 Reinforcing layer 4a, 5a Spiral reinforcing material 6 Reinforcing wire A1 Axial end A2 Outer peripheral surface (pipe outer peripheral surface)
A3 Axial tip surface (pipe tip surface) A4 Inner peripheral surface (pipe inner peripheral surface)
B Joint pipe B1 Inner peripheral surface (Fitting inner peripheral surface)
B2 Step part (joint part) B3 End face C Flow restricting means C1 Sealing cover C1 'Clamping part C2, C3 Storage part R Molten resin

Claims (5)

A synthetic resin pipe in which a plurality of layers are laminated to form a rigid pipe body, and a reinforcing layer is formed by spirally winding a reinforcing material between the plurality of layers,
An inner layer and an outer layer are formed of a hard resin as the plurality of layers , and a plurality of reinforcing wires extending linearly in the axial direction of the pipe body are embedded in the circumferential direction at predetermined intervals, respectively, between the inner layer and the outer layer the adhesive layer is formed, between the adhesive layer and the inner layer and the outer layer, by a helical reinforcement inclination angle of each winding to the spiral such that the opposite as the reinforcing material, wherein A synthetic resin pipe, wherein the reinforcing layer is formed along an inner peripheral surface and an outer peripheral surface of the adhesive layer. 2. The synthetic resin pipe according to claim 1, wherein the pipe body is formed by using the inner layer, the reinforcing wire, the outer layer, the adhesive layer, and the spiral reinforcing material in a similar synthetic resin. Said inner layer and said outer layer and forming a thermoplastic resin, according to claim 1 or 2, wherein in said inner layer and high thermoplastic resin fluidity than the thermoplastic resin of the outer layer to the formation of the adhesive layer Synthetic resin pipe. Upon producing synthetic resin pipe according to claim 1, 2 or 3, wherein cooling after laminating the adhesive layer, the spiral reinforcing member along the outer peripheral surface of the adhesive layer after the cooling step in a spiral A method for producing a synthetic resin pipe , characterized by being wound. Upon connecting the synthetic resin pipe according to claim 2, wherein the inner layer and the reinforcing wire member and the axial end portion of the pipe body in which the spiral reinforcing member and said outer layer and said adhesive layer is formed by syngeneic synthetic resin A method of connecting synthetic resin pipes , wherein the end faces are brought into contact with each other and thermally welded so that the heated and melted pipe body is in a straight line .

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