JP2012057671A - Piping material and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piping material that can reduce a joint portion, can reduce the number of piping construction processes, and in which a metal-made intermediate layer of the end face of a complex pipe does not contact with fluid such as water flowing therein, and to provide a manufacturing method of the piping material which can easily manufacture the piping material without generating a variation in rigidity caused by an environment and a human being, and without imparting damage to the complex pipe even if the complex pipe being a piping body is lengthy.SOLUTION: A diameter-expanded cylinder 31 of a disengagement prevention member 3a having an engagement part 32 is externally fit to a diameter-expanded part 1b formed at one end of the complex pipe 1, the diameter-expanded part 1b, the disengagement prevention member 3a and an in-core member 2 are set in a metal mold 8 while an in-core body 21 of the in-core member 2 is internally fit, resin which is the same as that of an inner layer 12 of the complex pipe 1 is injected into a cavity 81, an injection resin part 4a is molded, and an interface between the injection resin part 4a and the inner layer 12 is fused.

Description

  In the present invention, a joint portion having a connection structure with other piping material is provided in advance at an end portion of a metal composite pipe (hereinafter referred to as “composite pipe”), and a water supply / hot water supply pipe or a cold / hot water pipe for cooling / heating is provided. Alternatively, the present invention relates to a piping material used for a hot water facility or the like and a manufacturing method thereof.

As a pipe used for water supply / hot water supply pipes, cold / hot water pipes for heating and cooling, or hot water facilities, for example, the inner and outer layers are formed of a thermoplastic resin such as polyethylene, and the intermediate layer is formed of a metal such as aluminum 3 A composite tube composed of one or more layers is used.
Such composite pipes are conventionally made of other metals using pipe joints such as caulking joints (refer to Patent Document 1), one-touch joints (refer to Patent Document 2), and joints that tighten cap nuts (refer to Patent Document 3). It is designed to be connected to a piping material made of steel.

  Also, for the purpose of reducing manufacturing costs and saving resources, a plastic tube that can be plastically deformed, an annular spacer member that is fitted to the tip end side of the plastic tube, and a connecting member that is connected to the spacer member, The spacer member is formed with a convex portion on the outer periphery on the tip end side thereof, and the spacer member has a connection concave portion formed on the inner periphery thereof, and the convex portion of the plastic tube is formed in the connection concave portion. There has been proposed a connection body of a pipe in which is press-fitted (see Patent Document 4).

JP 2007-285405 A Japanese Patent No. 41799919 JP-A-6-346994 JP 2009-197926 A Japanese Patent No. 4464847

However, the pipe joint used for the conventional connection has one of the following problems because the joint body is formed of a metal material (mainly copper alloy) so as to withstand caulking and tightening.
(1) The cost is high due to fluctuations in metal prices, and the risk of stable supply is high.
(2) The weight increases.
(3) There is a risk of corrosion.
(4) Since the number of members constituting the joint is large and it is necessary to assemble them, man-hours and time are required for assembly, resulting in an increase in cost.
(5) There is a risk that a defective member may be used incorrectly during assembly, or that a product failure such as an assembly error may occur.
(6) Since the pipe joint is provided with a retaining structure and water stop structure, there is a problem that the entire pipe joint becomes large and piping in a narrow place cannot be performed.
(7) Since the fluid touches the end face of the pipe, in the case of the above composite pipe, the metal in the intermediate layer may corrode and may reduce the life of the pipe.

On the other hand, as a connection method between the resin piping material and the resin piping material, there is a connection method using a butt fusion or an electric fusion joint in addition to the above mechanical connection method.
However, in the butt fusion, the end faces of the pipe materials to be joined are melted with a hot plate or the like, and the end faces are brought into contact with each other and joined. Therefore, in the case of a composite pipe having a metal layer that does not melt in the intermediate layer, the surface pressure is applied to the molten resin when the pipe end face of another pipe material is pressed against the pipe end face of the composite pipe. It is difficult and cannot be fused well.

  On the other hand, in the electric fusion joint, the connection is made on the outer peripheral surface of the pipe. However, in the case of the composite pipe, the thickness of the resin outer layer is thin, and the molten resin cannot be sufficiently secured. Further, there is a problem that the flattening of the tube, etc., it is difficult to melt uniformly in the circumferential direction, and it is difficult to apply a surface pressure, so that stable fusion strength cannot be expressed.

In addition, a pipe in which a pipe end of a straight tube is faced in a molding die for injection molding of a connection object, and at the same time as the connection object is injection molded, the pipe end is connected to the connection object. A connection structure has already been proposed (Patent Document 5).
When adopting this connection structure to produce a piping material in which the joint part as a connection object is integrally formed at the pipe end, the amount of metal material used can be reduced and the joint part can be made smaller. There is an advantage that the number of piping construction man-hours can be reduced. Furthermore, even if the pipe is a composite pipe, the end face metal intermediate layer does not come into contact with fluids such as water flowing inside, and this pipe material may cause variations in strength due to the environment and people. In addition, there is an advantage that a stable connection quality between the composite pipe serving as the pipe main body and the joint is obtained.

However, the above connection structure has the following drawbacks.
In other words, it is necessary to support and fix the composite tube outside the mold so that the composite tube does not move until the injection resin is cured, but the other end of the composite tube is pressed with a jig or comes out of the mold of the composite tube Unless the outer surface of the portion is strongly tightened with a jig, the composite tube is easily pushed out of the mold by the injection resin pressure.
In addition, when the composite tube is long, it is difficult to hold the other end of the composite tube with a jig. If the outer surface of the composite tube is tightened strongly, it will lead to damage and deformation of the tube, resulting in stable and good quality. It is difficult to obtain.

  In view of the above circumstances, the present invention can reduce the joint portion and reduce the number of piping installation man-hours. Further, the pipe material in which the metal intermediate layer on the end face of the composite pipe does not come into contact with a fluid such as water flowing inside, and the pipe material becomes a pipe main body part without causing variations in strength due to the environment or people. It aims at providing the manufacturing method of the piping material which can be manufactured easily and without damaging a composite pipe, even if a composite pipe is long.

  In order to achieve the above object, a pipe material according to the present invention includes a pipe main body portion composed of a composite pipe having an outer layer and an inner layer made of a thermoplastic resin, and a metal intermediate layer, and an end of the pipe main body portion. And a joint part connected to another joint, and the joint part has a hook-like engaging part with which a part of a coupling holding tool with the other joint is engaged. The pipe main body includes a composite pipe main body and a diameter-expanded portion that is connected to the composite pipe main body and gradually increases in diameter toward the pipe end. An in-core member having an in-core body whose outer diameter is smaller than the opening end of the enlarged-diameter portion, and an end portion of the in-core body, A gap is formed between the enlarged diameter portion and the inner peripheral surface of the enlarged diameter portion from the opening end side of the enlarged diameter portion. Both of the in-core main body are in close contact with the inner peripheral surface of the pipe main body, and the other end of the in-core main body is mounted so as to protrude from the open end of the enlarged-diameter portion. The stopper cylinder includes at least a diameter-enlarged cylinder part whose inner peripheral surface gradually increases in diameter from one end to the other end, and a retaining member having the engagement part projecting outward from the diameter-enlarged cylinder part. It is in a state where a diameter cylinder part is fitted to the diameter-expanded part, and the injection-molded part has at least the in-core body made of an injection resin having a heat-sealing property with respect to an inner layer resin of a composite pipe. In addition, it is formed by injection molding so as to fill the gap between the inner peripheral surface of the enlarged diameter portion and to surround the outer peripheral surface of the portion protruding from the opening end of the enlarged diameter portion of the in-core body. It is said.

In the piping material of the present invention, the composite pipe constituting the piping main body is not particularly limited, and the inner layer and the outer layer may be a multilayer, or the inner layer and the outer layer are formed of different thermoplastic resins. It does not matter. For example, commercially available products such as Sulsui Chemical Co., Ltd. made by Sekisui Chemical Co., Ltd., in which the outer layer is made of high-density polyethylene, the inner layer is made of heat-resistant polyethylene, and the intermediate layer is made of aluminum, can be used.
The composite pipe main body part and the enlarged diameter part are not particularly limited. For example, the composite pipe main body part and the enlarged diameter part are formed by press-fitting a conical diameter-expanding jig into the pipe end part of the straight pipe composite pipe to enlarge the pipe end part. be able to.

As the taper angle of the expanded diameter portion increases, the retaining force of the retaining member can be increased as the taper angle increases, and the expansion of the inner diameter increases, but conversely, the outer diameter of the joint becomes too large or the tube extends. If the diameter is increased more than that, there is a risk of destruction. In addition, there is a preferred diameter expansion ratio depending on the composite pipe used, for example, when using the product name Eslon Super Ethromex made by Sekisui Chemical Co., Ltd. as a composite pipe, considering the elongation at break of aluminum in the intermediate layer, It is preferable to set the taper angle so that the expansion ratio is 27% or less, and actually 9 to 25%.
The expansion ratio (%) is expressed by the following formula (maximum outer diameter of the expanded portion−outer diameter of the composite pipe before expansion) / (outer diameter of the composite pipe before expansion) × 100.
Can be obtained from

The material of the in-core member constituting the in-core part is not particularly limited as long as it is not melted by the heat of the injection resin when the injection-molded part is injection-molded. For example, copper alloy such as gun metal, metal such as stainless steel, PPS ( Examples thereof include engineering plastics such as polyphenylene sulfide) and PPSU (polyphenylsulfone) and glass fiber reinforced engineering plastics.
Although an in-core member is not specifically limited, you may equip the other end of the in-core main body which protrudes from the pipe end of a composite pipe | tube with the flange part.

The retaining member constituting the retaining cylinder is not particularly limited as long as it is superior in strength to the joint body and is not melted by the heat of the injection resin when the injection molded part is injection molded. For example, a copper alloy such as gun metal Metal such as stainless steel, engineering plastics such as PPS (polyphenylene sulfide) and PPSU (polyphenylsulfone), and glass fiber reinforced engineering plastics.
In addition, it is preferable that both the in-core member and the retaining member are independently installed on the inner surface side or the outer surface side of the injection molded portion. However, even if it is formed continuously from the inner surface to the outer surface, it is not particularly limited as long as it is in close contact with the injection molded part and does not allow water to pass.

  Various materials can be selected as the resin that constitutes the injection molding part due to restrictions (temperature, pressure, water quality, etc.) depending on the usage environment and manufacturing conditions. However, considering the fusion with the inner layer of the composite pipe, the inner layer It is desirable to select the same material.

  The connection holder is not particularly limited as long as it can be engaged with the engagement portion and can maintain the connection state between the joint of the piping material and the other joint. For example, the opposing holding member that elastically clips the joint portion of both joints. In addition to the two clip portions provided, the piping material engagement portion of the present invention is inserted together with the engagement portions of other joints into the slit-like engagement holes provided in both clip portions. Then, what is called a fastener clip or a quick fastener (for example, see Japanese Patent Application Laid-Open No. 2010-151305) that is held in a connected state as an engaged state with the clip portion is used.

  In the pipe material manufacturing method according to the present invention, the injection pipe is injected and filled with the injection resin in a state where the composite pipe is disposed so that the pipe end portion of the composite pipe faces the cavity of the injection mold. It is characterized by molding.

  In the pipe material manufacturing method of the present invention, the expanded cylindrical portion of the retaining member is externally fitted to the expanded diameter portion of the composite pipe, and the in-core body of the in-core member is inserted and mounted into the composite pipe from the enlarged diameter portion side end. After mounting the pipe end of the composite pipe, the retaining member and the in-core member in the cavity of the injection mold, the cavity is injected and filled with a thermoplastic resin that has a heat-sealing property to the inner resin of the composite pipe. Thus, the injection molding part is molded.

  As described above, the piping material according to the present invention is integrally formed with a pipe body portion composed of a composite pipe having an outer layer and an inner layer made of a thermoplastic resin, and a metal intermediate layer, and an end portion of the pipe body portion. And a joint portion connected to another joint, the joint portion having a hook-like engagement portion with which a part of a connecting holder with the other joint engages. The pipe main body part has a composite pipe main body part and a diameter-expanding part that is connected to the composite pipe main body part and gradually increases in diameter toward the pipe end, and the joint part includes an in-core part, An in-core member having an in-core body whose outer diameter is smaller than the opening end of the enlarged-diameter portion, and the in-core member includes one end portion of the in-core body. Facing the inside of the pipe body from the opening end side of the part, forming a gap with the inner peripheral surface of the enlarged diameter part, One end portion peripheral surface of the in-core main body is in close contact with the inner peripheral surface of the pipe main body portion, and the other end of the in-core main body is mounted so as to protrude from the opening end of the enlarged diameter portion, and the retaining cylinder portion The at least the inner peripheral surface of the diameter-enlarged cylinder part that gradually expands from one end to the other end, and the retaining member that has the engagement part that protrudes outward from the diameter-enlarged cylinder part is the diameter-enlarged cylinder part. The injection molded part is made of an injection resin having a heat-sealing property with respect to the inner layer resin of the composite pipe, and at least the in-core main body and the diameter-expanded part. It is filled with the gap between the inner peripheral surface of the part and is formed by injection molding so as to surround the outer peripheral surface of the part that protrudes from the opening end of the enlarged diameter part of the in-core body. Can reduce the number of piping installation man-hours, La, never metallic intermediate layer of the composite tube end face is in contact with the fluid such as water flowing therethrough.

In the method for manufacturing a piping material according to the present invention, a diameter-enlarged portion is formed by expanding the pipe end portion of the composite pipe in a state in which the retainer member is externally fitted to the composite pipe. After the diameter tube portion is externally fitted to the formed enlarged diameter portion, the tube end portion of the composite tube and the retaining member are mounted in the cavity of the injection mold together with the in-core member. Since the pipe material of the present invention is manufactured by injection-filling a thermoplastic resin having heat-fusibility to the inner-layer resin into the cavity and molding the injection-molded portion, the molding conditions are constant. Thereby, the stable connection quality of the composite pipe used as a piping main-body part and a coupling part can be acquired, without producing the intensity | strength variation by an environment or a person.
And since a composite pipe | tube is connected with an injection molding part by a fusion | melting state simultaneously with injection molding of an injection molding part, the piping material of this invention can be obtained quickly and cheaply.

It is sectional drawing showing the 1st Embodiment of the piping material concerning this invention, and the state before mounting | wearing with another coupling. It is sectional drawing showing the mounting state to the other coupling of the piping material of FIG. It is a figure which illustrates roughly an example of the manufacturing method of the piping material of FIG. It is a figure which illustrates roughly the effect of the piping material of FIG. 1, Comprising: The figure (a) represents the water stop state of this invention, and the same figure (b) is the water stop state of the pipe material as a comparative example. Is shown. It is sectional drawing showing the 2nd Embodiment of the piping material concerning this invention, and the state before mounting | wearing with another coupling.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.
1 and 2 show a first embodiment of a piping material according to the present invention.

As shown in FIGS. 1 and 2, this piping material A is integrally provided with a joint at the end of the piping material main body composed of the composite pipe 1.
The composite tube 1 has a three-layer structure of an outer layer 11 made of high-density polyethylene, an inner layer 12 made of heat-resistant polyethylene, and an intermediate layer 13 made of aluminum. The composite tube main body portion 1a and the enlarged-diameter portion 1b are combined. I have. Further, the interface between the outer layer 11 and the intermediate layer 13 and the interface between the intermediate layer 13 and the inner layer 12 are joined via a modified olefin adhesive, although not shown.
The diameter-expanded portion 1b gradually increases in diameter from the end of the composite tube main body portion 1a toward the tube end at a spread angle of 4.5 ° to 8.5 °.

The joint portion includes an in-core portion made of the in-core member 2a, a retaining cylinder portion made of the retaining member 3a, an injection molding portion 4a, and an O-ring 5 as a ring-shaped sealing material.
The in-core member 2a is made of copper alloy such as gun metal, metal such as stainless steel, engineering plastic such as PPS (polyphenylene sulfide) and PPSU (polyphenyl sulfone), and glass fiber reinforced engineering plastic. And has

The in-core main body 21 includes a water flow tube portion 21a, a fitting ridge portion 21b, and a retaining ridge portion 21c.
The outer diameter of the water flow tube portion 21a is slightly smaller than the inner diameter of the composite tube main body portion 1a (for example, when the composite tube main body portion 1a is 16A size, the diameter is 1-2 mm), and the wall thickness of the peripheral wall is 1.0 mm. The length is longer than the axial length of the enlarged diameter portion 1b.

The fitting protrusion 21b is provided so as to project outward at one end of the water flow tube 21a, and its outer diameter is substantially the same as or slightly larger than the inner diameter of the composite tube main body 1a. The outer peripheral edge is chamfered in a tapered shape.
The flange portion 22 is provided so as to project outward at the other end portion of the water flow tube portion 21a, and the outer diameter thereof is substantially the same as the inner diameter of the receiving port 61 of the metal joint 6 as another joint described later. ing.

  In the in-core member 2a, the fitting protrusion 21b is fitted into the end of the composite tube main body 1a, and the outer peripheral surface thereof is in close contact with the inner peripheral surface of the composite pipe main body 1a. The joint protrusion 21 b side enters the enlarged diameter portion 1 b, and the flange portion 22 side protrudes from the pipe end of the composite pipe 1.

  The retaining member 3a is made of copper alloy such as gun metal, metal such as stainless steel, engineering plastic such as PPS (polyphenylene sulfide), PPSU (polyphenyl sulfone), or glass fiber reinforced engineering plastic. And an engaging portion 32.

The expanded diameter cylindrical portion 31 has an inner diameter that is substantially the same as or slightly larger than the outer diameter of the composite tube main body portion 1a, and the inner diameter gradually increases toward the other end. Has a cylindrical shape that is substantially the same as the axial length of the enlarged diameter portion 1b.
The engaging portion 32 is provided along the other end of the enlarged diameter cylindrical portion 31, is provided to protrude outside the enlarged diameter cylindrical portion 31 in a ring shape, and the inner diameter thereof is the same as the inner diameter of the other end of the enlarged diameter cylindrical portion 31. It has become.

  In the retaining member 3a, the enlarged diameter cylindrical portion 31 is externally fitted to the enlarged diameter portion 1b of the composite pipe 1, and the engaging portion 32 protrudes from the tip of the enlarged diameter portion 1b.

The injection molded portion 4a fills the gap surrounded by the enlarged diameter portion 1b of the composite tube 1, the engaging portion 32 of the retaining member 3a, the in-core main body 21, and the fitting protrusion 21b. The interface portion of the tube 1 with the inner layer 12 is fused with the inner layer 12.
The injection molding portion 4a is such that the portion from the end surface of the engaging portion 32 of the retaining member 3a of the water flow tube portion 21a to the flange portion 22 of the water flow tube portion 21a is the water flow tube portion 21a and the retaining protrusion ridge portion 21c. Is provided so as to surround the periphery of the flange portion 22 and has substantially the same outer diameter as that of the flange portion 22 except for the end portion on the flange portion 22 side. The fitting groove 41 of the O-ring 5 is formed between them.

The O-ring 5 is made of synthetic rubber such as EPDM (ethylene-propylene-diene copolymer) or fluorine rubber, and is fitted in the fitting groove 41.
And this piping material A is a differential port part into which the part protruded outside from the engaging part 32 of the injection molding part 4 a and the flange part 22 of the in-core member 2 a are inserted into the receiving port 61 of the joint 6.

Next, with reference to FIG.1 and FIG.2, the connection method with the metal couplings 6 as other couplings of this piping material A is demonstrated.
That is, the joint 6 includes a receiving port 61 on one side and a threaded cylindrical portion 62 on the other side.
The receiving port 61 has a cylindrical shape whose inner peripheral surface has substantially the same shape as the outer peripheral surface of the injection port portion 4a including the fitting groove 41 from the flange portion 22 of the in-core member 2a of the piping material A. And the engaging part 61a which protrudes outside like a bowl is provided at the tip.
The engaging part 61 a has substantially the same outer diameter as the engaging part 32.

As shown in FIG. 1, the piping material A is arranged so that the opening portion faces the inside of the receiving port 61, and the inserting portion is inserted and fitted into the receiving port 61 as shown in FIG. 2.
In this state, the engaging portion 61a of the joint 6 and the end surfaces of the engaging portion 32 are in close contact with each other, and the O-ring 5 is in close contact with the inner peripheral surface of the receiving port 61 to ensure a water-stopping state. .

  Next, a part of both engagement parts 32 and 61a enter into the engagement holes 71a respectively provided in the clip parts 71 (only one side is shown in FIGS. 1 and 2) facing the connection holder 7. Then, after attaching the connecting holder 7 and elastically clipping both sides of the joint portion between the engaging portion 32 and the engaging portion 61 a by both clip portions 71, the open ends of both clip portions 71 are connected to the connecting holder 7. Locking is performed by a locking claw 72 a provided to face the separation preventing member 72.

Next, a method for manufacturing the piping material A will be described in the order of steps.
(1) For example, the retaining member 3a is first fitted on an existing composite pipe. When joint portions are formed at both ends, the two retaining members 3a are externally fitted in a back-to-back state so that the engaging portion 32 side is on the outside.
(2) The composite pipe 1 is formed by forming the diameter-expanded portion 1b by expanding the diameter of the end of the existing composite pipe using a diameter-expanding jig (not shown).
(3) The in-core member 2 a is set on the movable mold (or fixed mold) side of the injection mold 8.
(4) The retaining member 3a is slid from the composite pipe main body 1a side to externally fit the enlarged diameter cylindrical portion 31 to the enlarged diameter portion 1b, and the outer peripheral surface of the fitting protrusion 21b is the proximal end of the enlarged diameter portion 1b. The pipe end of the composite pipe 1 and the retaining member 3a are set on the movable mold (or fixed mold) side of the injection mold 8 so as to be in pressure contact with the inner peripheral surface of the composite pipe main body 1a.
(5) The movable mold and the fixed mold of the injection mold 8 are closed. That is, in this state, as shown in FIG. 3, the enlarged diameter portion 1 b, the retaining member 3 a and the incore member 2 a of the composite pipe 1 are nested and set in the cavity 81 of the injection mold 8.
(6) The cavity 81 is injected and filled with the same heat-resistant polyethylene resin as that of the inner layer 12 to mold the injection molded portion 4a.
(7) Install the O-ring 5 in the O-ring fitting groove 41.

Since the piping material A is configured as described above, it has the following excellent performance.
(1) Since the inner layer 12 and the injection molded portion 4a are fused at the interface, the aluminum of the intermediate layer 13 is corroded by being in contact with the water flowing in the pipe. There is no. That is, it is possible to always ensure a stable construction state.
(2) Since the composite pipe 1 includes the enlarged diameter portion 1b, and the enlarged diameter cylindrical portion 31 of the retaining member 3a is fitted on the enlarged diameter portion 1b, the composite pipe 1 is joined by the fluid pressure flowing in the pipe. When a force is applied in the direction of detachment from the portion, the enlarged diameter cylindrical portion 31 of the retaining member 3a is firmly held by the inner peripheral surface of the outer peripheral surface of the expanded diameter portion 1b of the composite pipe 1.
Therefore, even if the adhesive that joins the inner layer 12 and the intermediate layer 13 becomes insufficiently bonded due to deterioration over time, the injection-molded portion 4a does not stretch and cause delamination. That is, the durability is excellent.
(3) At the time of injection molding of the injection molding part 4a, the composite pipe 1 is provided with the enlarged diameter part 1b, and this enlarged diameter part 1b faces the mold 8 and is supported by the inner wall surface of the mold 8. It is not necessary to prevent the composite pipe 1 from coming off from the mold 8 with a large pressure, and it is only necessary to grip the portion adjacent to the enlarged diameter portion 1b of the composite pipe main body portion 1a.
That is, if the part where the joint part of the composite pipe is provided is also straight, the other end of the composite pipe must be pressed with a jig, or the outer surface of the part of the composite pipe that goes out of the mold must be tightened with a jig. The composite pipe is easily pushed out of the mold by the injection resin pressure, but when the composite pipe is long, it is difficult to hold the other end of the composite pipe with a jig, and the outer surface of the composite pipe is strongly tightened. In many cases, this leads to damage and deformation of the tube. However, according to the present invention, the tube can be easily positioned and fixed at the time of injection molding without using a complicated structure or jig.
(4) Since the O-ring 5 is directly received by the injection molding part 4a, there is no fear of water leakage due to wraparound from the in-core member 2a side. That is, since the in-core member 2a and the injection-molded portion 4a are not fused, the fluid flowing in the piping material A tends to wrap around from the joint 6 side as shown by a thick line in FIG. As the fluid pressure increases, fluid may enter between the in-core member 2a and the injection resin portion 4a, but the O-ring 5 is located between the inner peripheral surface of the receiving port 61 and the injection resin portion 4a. The fluid that is sandwiched and compressed and that passes between the in-core member 2a and the injection resin portion 4a or that wraps around from the side of the joint 6 is reliably blocked by the O-ring 5 and is shown in FIG. In other words, water does not leak outside through the path indicated by the two-dot chain line, that is, between the joint 6 and the injection resin portion 4a and between the engagement portion 32 and the engagement portion 61a. On the other hand, as shown in FIG. 4B, when the O-ring 5 is a piping material X having a structure in which the O-ring 5 is sandwiched between the inner peripheral surface of the receiving port 61 and the incore member 2b, the incore member 2b When a fluid flows between the injection resin part 40, a water channel W as shown in FIG. 4B is formed, and there is a possibility that water leaks to the outside through between the engagement part 32 and the engagement part 61a. is there.
(5) Since the in-core member 2a is arranged inside the injection-molded part 4a and the in-core part is provided, even if the injection-molded part 4a is formed of a soft resin, the injection-molded part 4a is not deformed to the inner surface side. Long-term watertightness of the fused part and the sealing material part can be secured.
(6) Since the outer peripheral surface of the fitting ridge portion 21b of the in-core member 2a is in close contact with the inner peripheral surface of the composite tube main body portion 1a, the injection projection portion 4a is injected into the composite tube main body portion side. The resin does not flow, and the injection molding portion 4a can be accurately injection molded. Therefore, even when the composite pipe 1 is very long, injection molding is possible without forming a complicated mold structure.
(7) Since the surface of the inner layer 12 of the composite tube 1 is melted by the injection resin temperature at the time of injection, the injection molded part 4a and the inner layer 12 are fused and integrated, so compared with hot plate fusion, electric fusion, etc. The temperature and pressure are stabilized, the influence of the external environment (disturbance) is small, and stable fusion quality can be ensured.
(8) Since the fusion splicing is performed by injection molding, it is possible to obtain a stable connection portion quality without causing variations in strength due to the environment or people by making the molding conditions constant.
(9) Since the in-core member 2a is provided, sufficient strength can be ensured even if the thickness of the injection molded portion 4a is reduced.
That is, since the thickness of the injection molding part 3a can be reduced, as a result, the entire joint part can be made very small, and it is easy to cope with piping in a narrow place and bending near the joint part.
(10) Since the composite pipe 1 and the joint portion are connected simultaneously with the molding of the injection molding portion 4a, a joining structure can be formed quickly and inexpensively. In addition, the work space and equipment can be reduced compared to the case where the joint is formed and connected in separate processes, which is optimal for prefabrication.
(11) Since the in-core member 2a includes the retaining protrusion 21c, the in-core member 2a can be securely prevented from coming off from the injection resin portion 4a.

FIG. 5 shows a second embodiment of the piping material according to the present invention.
As shown in FIG. 5, in this piping material B, the retaining member 3 b includes a ring-shaped groove 33 along the inner peripheral surface of the engaging portion 32, and the injection molding portion 4 b enters the groove 33. It is the same as that of the piping material A except that the locking rib portion 42 is provided.

  The piping material B can reliably prevent the retaining member 3b from coming off to the composite pipe body 1a side by the locking rib portion 42.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the joint body is formed of the same polyethylene as the outer layer and the inner layer of the composite pipe, but other thermoplastic resins may be used as long as they can be fused to the composite pipe.
In the above embodiment, the mold has one cavity, but a plurality of cavities may be provided in the mold in order to obtain a large number of cavities.

In the above-described embodiment, the piping material is connected and fixed to other joints by the connection holder, but the in-core has a shape including a screw cylinder continuously to the second flange portion, and this screw. You may enable it to join directly to a header etc. using a cylinder.
In the above embodiment, two O-rings are provided, but one or three or more may be used.

In the above embodiment, the other joint connected to the piping material of the present invention is made of metal, but may be made of engineering plastic.
In the above embodiment, there is one O-ring groove, but two or more may be provided.
In the above embodiment, the in-core member is set on the movable mold (or fixed mold) of the injection mold, and then the enlarged diameter portion of the composite pipe and the retaining member are movable (or fixed mold) of the injection mold. After setting the in-core member so that the outer peripheral surface of the fitting ridge portion 21b is pressed against the inner peripheral surface of the composite pipe main body portion 1a at the base end of the enlarged diameter portion 1b, You may set to the movable mold | type (or fixed mold | type) side of an injection molding die with the enlarged diameter part of a composite pipe | tube, and a retaining member.

A, B Piping material 1 Composite pipe (Piping body)
DESCRIPTION OF SYMBOLS 11 Outer layer 12 Inner layer 13 Middle layer 1a Composite pipe main-body part 1b Expanded diameter part 32 Engagement part 2a Incore member (incore part)
21 in-core main body 21a water flow tube portion 21b fitting ridge portion 21c retaining ridge portion 22 flange portion 3a, 3b retaining member (retaining tube portion)
31 Enlarged cylinder part 32 Engagement part 4a, 4b Injection molding part 6 Joint (other joints)
7 Connection holder 8 Mold 81 Cavity

Claims (3)

A pipe body part composed of a composite pipe having an outer layer and an inner layer made of a thermoplastic resin, and a metal intermediate layer, and a joint part integrated with an end of the pipe body part and connected to another joint And the joint part is a piping material having a hook-like engagement part with which a part of a connection holder with another joint is engaged,
The pipe main body portion has a composite pipe main body portion, and a diameter-expanding portion that is connected to the composite pipe main body portion and gradually increases in diameter toward the pipe end,
The joint part includes an in-core part, a retaining cylinder part, and an injection molding part,
The in-core member includes an in-core member having a cylindrical in-core body whose outer diameter is smaller than the opening end of the enlarged-diameter portion, and the in-core member includes one end portion of the in-core body from the opening end side of the enlarged-diameter portion into the pipe body portion. A gap is formed between the inner peripheral surface of the enlarged diameter portion, the peripheral surface of one end portion of the in-core main body is in close contact with the inner peripheral surface of the pipe main body portion, and the other end of the in-core main body is It is in a state of being mounted so as to protrude from the open end of the diameter part,
The retaining cylinder part has a diameter-enlarging cylinder part in which at least an inner peripheral surface gradually increases in diameter from one end to the other end, and a retaining member having the engagement part that projects outward from the diameter-enlarging cylinder part, It is in a state of being mounted so as to externally fit the expanded diameter cylindrical portion to the expanded diameter portion,
The injection molded part has an injection resin having heat-fusibility to the inner layer resin of the composite pipe, and at least fills a gap between the water flow cylinder part and the inner peripheral surface of the enlarged diameter part. A piping material, wherein the piping material is formed by injection molding so as to surround an outer peripheral surface of a portion protruding from an opening end of the enlarged diameter portion.   The piping material according to claim 1, wherein the in-core member includes a flange portion at the other end of the in-core main body.   The diameter-enlarged portion is formed by expanding the pipe end of the composite pipe in a state in which the retainer member is externally fitted to the composite pipe. A thermoplastic resin having a heat-sealing property to the inner layer resin of the composite pipe after fitting the pipe end and the retaining member of the composite pipe together with the in-core member into the cavity of the injection mold. The method for manufacturing a piping material according to claim 1, wherein an injection molding part is formed by injection filling the cavities into a cavity.

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