JP2007205506A - Multilayer pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer pipe with metal intermediate layers, capable of being connected without reducing the inner diameter of a connection part during connection. <P>SOLUTION: The multilayer pipe comprises a plurality of layers including the metal intermediate layers. The metal intermediate layers each formed at a predetermined length are discontinuously arranged at predetermined axial spaces. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multilayer pipe composed of a plurality of layers including a metal intermediate layer among pipes used for transferring fluid such as water supply, hot water supply, cooling / heating, drainage, and air conditioning refrigerant.

  In a pipe used for transferring a fluid, various performances are required depending on the transfer conditions of the fluid. For example, pipes for hot water supply and cold / hot water are required to have long-term safety in a high temperature region, safety against electrochemical corrosion and water quality change, easy workability due to flexibility and lightness, and the like. Sprinkler piping is required to have a performance capable of withstanding severe conditions such as pressure resistance, vibration resistance, earthquake resistance, and durability.

  It is not easy to satisfy these various performances with a tube made of a single material. Therefore, the outer and inner surfaces of a metal tube (layer) with excellent mechanical strength can have heat resistance and corrosion resistance. Conventionally, a three-layer pipe (multi-layer pipe) provided with excellent thermoplastic resin layers has been provided (see Patent Document 1).

  When piping for transferring a fluid (for example, water) using a three-layer pipe provided with an intermediate layer (metal intermediate layer) formed of these metals, a place where a long three-layer pipe is generally provided The piping is performed by cutting the length suitable for the three-layer pipe and connecting the end portions of the three-layer pipe cut to the predetermined length by the pipe joint. At this time, since the three-layer tube includes a metal intermediate layer, the metal intermediate layer is exposed (appears) on the cut surface formed by cutting.

  In this case, as shown in FIG. 4, a pipe joint 40 having a tapered receiving port 41, which has been conventionally performed, is used, and the inner peripheral surface 42 of the receiving port 41 of the tapered pipe joint 40 and A quick-drying adhesive is applied to the outer peripheral surface 52 of the tube end portion (insertion) 51 of the three-layer tube 50, the applied surface is lubricated with a solvent in the adhesive, and the tube end portion 51 is received by the receiving port 41 of the pipe joint 40. The adhesive and the swollen layer are spread and pressed into each other (in the direction of arrow α), and the inner peripheral surface 42 and the outer peripheral surface 52 of the pipe end 40 of the pipe joint 40 are heated and melted by a heating tool. The pipe joint 40 that stops water tightly (sealed) at the outer peripheral surface 52 of the three-layer pipe 50 such as a connection method in which the pipe end 51 is quickly pressed into the pipe joint receiving port 41 (in the direction of the arrow α) and the interface is fused. It was considered to connect according to the connection method used.

  However, in such a connection method, the cut surface (tube end) 51 cannot be completely blocked, so that the metal intermediate layer 53 exposed from the cut surface 51 comes into contact with water (fluid) flowing in the tube. . As a result, there were concerns about problems such as oxidation and corrosion of the metal intermediate layer 53 in contact with water at the pipe end 51 in the connection portion.

  Therefore, when connecting the three-layer tube 50 with the metal intermediate layer 53 exposed to the tube end portion (cut surface) 51 as described above, the tapered inner peripheral surface 61 as shown in FIG. Three outer cylinder portions 610 that are used as a joint surface with respect to the outer peripheral surface 52 of the end portion 51, and an inner cylinder 620 that includes a tapered outer peripheral surface 62 that serves as a joint surface with respect to the inner peripheral surface 54 of the three-layer tube end portion 51. The connection method using the pipe joint 60 for layer pipes (multilayer pipe) was provided (refer patent document 2).

That is, when connecting the three-layer pipe 50 with the metal intermediate layer 53 exposed to the pipe end 53, a quick-drying adhesive is attached between the inner and outer cylinders of the three-layer pipe joint 60, and the inner circumference of the three-layer pipe is increased. The inner peripheral surface 54 of the three-layer tube 50 is such that the surface layer 54 is coated with the adhesive and the three-layer tube end portion 51 is press-fitted into the annular space between the inner and outer cylinder portions (in the direction of arrow β). Pipe fittings were provided to connect to stop water. In this way, the use of the three-layer pipe joint 60 that stops water on the inner peripheral surface 54 of the three-layer pipe 50 seals the metal intermediate layer 53 that appears (exposed) at the three-layer pipe end 51. The three-layer pipe 50 with the metal layer exposed at the end of the pipe can be connected without corroding the water flowing in the pipe and without corroding the metal intermediate layer 53.
JP-A-2-290617 JP-A-7-301374

  However, when the three-layer pipe 50 is connected using such a three-layer pipe joint 60, the inner diameter (port diameter) d of the inner cylinder 620 to be joined to the inner peripheral surface 54 of the three-layer pipe is the inner diameter of the three-layer pipe 50. Since it is smaller than (aperture) D, there has been a problem that the flow rate of water (fluid) that can pass (flow) through such a portion is smaller than the flow rate that can flow inside the three-layer tube 50. .

  That is, the multilayer pipe (three-layer pipe) 50 in which the metal intermediate layer 53 is exposed to the cut surface 51 that must be connected by using a pipe joint 60 for a three-layer pipe that stops at such an inner peripheral surface 54. In this case, it is necessary to determine the inner diameter D of the multilayer pipe 50 to be used on the basis of the flow rate at the connection portion, and use a pipe that can be connected by a pipe joint 40 (see FIG. 4) of a type that stops at the outer peripheral surface 52. Therefore, a pipe having a larger inner diameter than the pipe must be used, which causes a problem that the cost increases.

  Therefore, in view of the above problems, the present invention has an object to provide a multilayer tube that can be connected so that the inner diameter at the connection portion does not become small at the time of connection even when the metal intermediate layer is provided. To do.

  Therefore, in order to solve the above problems, a multilayer tube according to the present invention is a multilayer tube composed of a plurality of layers including a metal intermediate layer, and the metal intermediate layer is formed to have a predetermined length in the axial direction. In addition, it is characterized by being disposed intermittently at a predetermined interval.

  With the above configuration, when cutting the multilayer tube, the multilayer pipe is cut so as to pass between the metal intermediate layer disposed at the predetermined interval and the metal intermediate layer disposed adjacent thereto. Then, the metal intermediate layer can be cut so as not to be exposed on the cut surface.

  The metal intermediate layer may be formed such that the predetermined length is longer than the predetermined interval.

  By setting it as the said structure, it can cut | disconnect to predetermined length so that a metal intermediate | middle layer may not be exposed to a cut surface like the above. In addition, since the portion where the metal intermediate layer of the multilayer tube is disposed can be fixed in a bent state (bend fixing), the multilayer tube cut into a predetermined length as the metal intermediate layer disposed becomes longer. Can be fixed (bend fixed) in a state bent to a desired shape in accordance with the piping location, so that the piping work (construction) can be easily performed.

  The predetermined interval may be 10 mm or more and 10,000 mm or less.

  With the above configuration, when the position corresponding to the predetermined interval of the multilayer tube is cut with a cutting tool, the metal intermediate layer is not exposed to the cut surface (without appearing), and oxygen permeated from the cut surface. It is possible to prevent the metal intermediate layer from being affected by external or in-pipe fluid such as oxidative corrosion.

  In addition, with such a configuration, the range in which the metal intermediate layer is disposed with respect to the multilayer tube is very wide compared to the predetermined interval, so that bending and fixing in a desired shape is further performed. This makes it easier to perform piping work.

  The metal intermediate layer may be made of aluminum.

  By setting it as the said structure, it becomes difficult to permeate | transmit oxygen in air | atmosphere in a pipe | tube. That is, it is possible to prevent oxygen in the atmosphere from passing through the inside (inside the pipe) through the wall of the multilayer pipe and dissolving in the fluid.

  As a result, for example, when the multilayer pipe is used as a pipe when circulating hot water for cooling and heating, etc., oxygen in the atmosphere permeates through the pipe wall of the hot water pipe and dissolves in the fluid (hot water). However, if it is used for a long time in this state, oxygen dissolved in the hot water inside may oxidize and corrode metal parts such as a heat source machine, but the metal intermediate layer of the multilayer tube is disposed. Since the oxygen does not permeate the tube wall from the portion, the amount of oxygen dissolved in the fluid can be reduced, and the oxidative corrosion can be reduced.

  Furthermore, since aluminum has a lower specific gravity than other metals, the weight of the multilayer pipe can be reduced, so that piping work can be easily performed and workability is improved.

  The metal intermediate layer may be formed of copper or SUS.

  By setting it as the said structure, it can make it difficult to permeate | transmit oxygen into a pipe | tube like the above. Further, since copper or SUS has excellent corrosion resistance against water, there is no problem even if it comes into contact with water. Therefore, when the multilayer pipe is used for hot water supply or water supply, that is, the fluid flowing in the pipe is water. In this case, it is possible to directly branch out water (or hot water) flowing through the pipe by making a hole in the pipe wall where the metal intermediate layer is disposed without using a pipe joint for branching. Become.

  Moreover, it is good also as a structure which further arrange | positions the heat insulating material of thickness 3mm or less on the outer peripheral surface of outermost layer.

  By setting it as the said structure, a multilayer pipe | tube (multilayer pipe | tube with a heat insulating material) provided with sufficient heat retention function can be obtained, without enlarging an outer diameter too much here now. Accordingly, handling at the construction site is facilitated, and workability is improved. Furthermore, since the heat insulating material is as thin as 3 mm or less, the outer diameter of the entire multilayer tube including the heat insulating layer (heat insulating material) is not so large and bending is easy to perform.

  As described above, according to the present invention, even if a metal intermediate layer is provided, the metal intermediate layer can be cut so that the metal intermediate layer is not exposed at the cut surface. It becomes possible to provide a multilayer tube that can be connected so as not to become small.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the multilayer tube 1 according to the present embodiment is formed as a cylindrical body having the same diameter in the axial direction, and the tube wall includes a plurality of layers along the circumferential direction. That is, it is configured by arranging a plurality of tubular (tubular) layers having the same central axis so as to be laminated. In the case of this embodiment, an inner layer (innermost layer) 2 formed of a thermoplastic resin from the inside of the multilayer tube 1 toward the outside (radially outward from the central axis), a metal intermediate layer 3 formed of metal, It is comprised by laminating | stacking three layers with the outer layer (outermost layer) 4 formed with a thermoplastic resin in order.

  More specifically, for example, the multilayer pipe 1 is formed as a cylindrical body having an outer diameter of 16 mm, an inner diameter of 12 mm, and a wall thickness (the thickness of the pipe wall) of about 2 mm. It is used as piping for use. As for the thickness of each layer, the inner layer 2 is 0.90 mm, the metal intermediate layer 3 is 0.20 mm, and the outer layer is 0.90 mm in the portion where the multilayer tube 1 is composed of three layers. Each layer is bonded via an adhesive layer (adhesive) 5. The adhesive layer 5 is made of deformed polyethylene and has a thickness of approximately 0.05 mm. In the three layers constituting the multilayer tube 1, the inner layer 2 and the outer layer 4 are made of high heat-resistant polyethylene, and the metal intermediate layer 3 is made of reinforced aluminum.

  The respective layers need not be limited to the above materials. That is, the inner layer 2 only needs to be flexible and have corrosion resistance to the fluid flowing in the multilayer tube 1, so that vinyl chloride, polyethylene, crosslinked polyethylene, polypropylene, acrylic resin, fluorine resin, amide resin Further, it may be a thermoplastic resin such as silicone resin, polyethylene terephthalate, or polybuden.

  Further, the outer layer 4 may be the same thermoplastic resin as the inner layer 2, and further protects the metal intermediate layer 3 and improves the heat retaining property, such as soft vinyl chloride resin, natural rubber, synthetic rubber, etc. It may be a plastic resin.

  Further, the metal intermediate layer 3 need not be limited to reinforced aluminum as long as it has a low oxygen permeability and can be easily bent and fixed when placed on the pipe. Therefore, metals such as aluminum, aluminum alloy, iron, copper, and SUS may be used. Further, the adhesive layer 5 need not be limited to deformed polyethylene.

  As shown in FIG. 2, the metal intermediate layer 3 is disposed so as to be sandwiched between the inner layer 2 and the outer layer 4 via adhesive layers 5 and 5. A plurality of metal intermediate layers 3 are arranged such that the central axes are on the same straight line and the intervals between them are a constant interval W. The metal intermediate layers 3, 3,... All have the same length L in the central axis (axial core) direction. The length L of the metal intermediate layers 3, 3,... Is 1000 mm, and the intervals W formed between the adjacent metal intermediate layers 3, 3 are all 100 mm. The tube wall of the multilayer tube 1 corresponding to the position of the interval W is composed of two layers because the metal intermediate layer 3 does not exist. That is, the inner layer 2 and the outer layer 4 are disposed so as to face each other with the adhesive layers 5 and 5 therebetween.

  In the present embodiment, the plurality of metal intermediate layers 3, 3,... Disposed in one long multilayer tube 1 are formed so that their lengths L are constant. There is no need to be limited to this, and several types of metal intermediate layers having different lengths may be regularly arranged, and each may have a different length. Similarly, the intervals W, W,... Need not be constant and may be different.

  Referring back to FIG. 1, the positions where the metal intermediate layer 3 does not exist in the tube wall, that is, the outer peripheral surface of the multilayer tube 1 corresponding to the interval W (the outer peripheral surface of the outer layer 4) are marked 6, 6. It is attached. This mark 6 is for indicating a position where the multilayer tube 1 can be cut so that the metal intermediate layer 3 is not exposed to the cut surface by cutting the multilayer tube 1 at such a position. In this embodiment, the mark 6 is attached by printing a thick line in the circumferential direction on the surface of the outer layer 4, but it is not necessary to be limited to this, as long as it can show a cut portion. Other symbols (for example, a triangle mark) or the like may be printed, a symbol or the like may be imprinted, and another member such as a tape may be attached.

  Next, a method for manufacturing a multilayer tube according to the present embodiment will be described with reference to FIG. 3. First, the manufacturing apparatus 20 will be described.

  In FIG. 3, reference numeral 21 denotes a supply bobbin of a band-shaped reinforced aluminum material. Reference numeral 22 denotes a pretreatment tank, which can perform, for example, degreasing treatment, rust removal treatment, rust prevention treatment, and the like. Reference numeral 23 denotes a cutting device, which can cut and feed the belt-shaped reinforced aluminum material 110 into a predetermined length. 24 is a U-shaped shaping apparatus. Reference numeral 25 denotes a circular tube shaping device, in which a U-shaped belt-shaped reinforced aluminum material 110 is shaped (formed) in a tubular shape. Reference numeral 26 denotes a welding apparatus, which is used for welding seams at both side edges of the band-shaped reinforced aluminum material 110 formed into a tubular shape (tubular shape). Reference numeral 27 denotes a thermoplastic resin extrusion die, and includes a horizontal cylindrical passage portion 271, a vertical passage portion 272, and a box portion 273 each having a discharge port for discharging an adhesive along the outer periphery of the front end portion and discharging high heat-resistant polyethylene. The vertical passage portion 272 is inserted into the opening of the semi-tubular reinforced aluminum material 110 conveyed between the U-shaped shaping device 24 and the tubular shaping device 25, and the horizontal cylindrical passage portion 271 is strengthened in the tubular shaping. It is inserted into the aluminum material, and the discharge part 274 is located downstream of the welding device 26. 28 is an extrusion apparatus for coating the outer layer of the thermoplastic resin, 29 is a cooling tank, 30 is a printing apparatus for printing a mark indicating the cutting position, and 31 is a cutting apparatus.

  In order to manufacture the multilayer tube 1 using the manufacturing apparatus 20, first, the belt-shaped reinforced aluminum material 110 is sent out from the supply bobbin 21 to the downstream side. Next, after performing a predetermined pretreatment in the pretreatment tank 22, the band-shaped reinforced aluminum material 110 is cut into a predetermined length (a desired metal intermediate layer length) by the cutting device 23. The band-shaped reinforced aluminum material 110 cut to a predetermined length is passed through the U-shaped shaping device 24, and the band-shaped reinforced aluminum material 110 is shaped (formed) in a U-shape. Further, the U-shaped aluminum material 110 is formed into a tubular shape by the tubular shaping device 25, and then the seam is welded by the welding device 26. The adhesive (modified polyethylene) is discharged from the outer periphery of the distal end of the horizontal cylindrical passage portion 271 of the thermoplastic resin extrusion mold 27 to the inner surface of the welded metal tube, and the thermoplastic resin (high heat resistant polyethylene) is discharged. Cover the inner peripheral surface of the metal tube.

  In this manner, after the thermoplastic resin layer (inner layer of the multilayer tube 1) is extrusion coated, the outer peripheral surface of the metal tube is coated with the thermoplastic resin layer (outer layer of the multilayer tube 1) by the extrusion device 29. The metal tube coated with the inner layer and the outer layer is cooled by passing through the cooling tank 29, and a mark indicating the cutting position is printed on the surface position of the multilayer tube 1 corresponding to the adjacent metal intermediate layer by the printing device 30. Then, the multilayer tube 1 is obtained by cutting into a predetermined length by the cutting device 30.

  In the multilayer tube 1 manufactured as described above, the metal intermediate layer is disposed at a predetermined interval. By cutting the multilayer tube 1 within the predetermined interval, the metal intermediate layer is exposed on the cut surface. Can be cut so as not to. Even when the multilayer pipe 1 cut in this way is connected by a pipe joint of the type that is joined at the outer peripheral surface of the end portion, the metal intermediate layer flows through the pipe because the metal intermediate layer is not exposed from the cut surface. There is no contact (touch) with the fluid, and corrosion does not occur. Therefore, it is not necessary to use a type of pipe joint that is joined on the inner peripheral surface of the multilayer pipe 1, and the connection can be made so that the inner diameter of the connection portion of the multilayer pipe 1 does not become smaller than other parts. .

  The multilayer pipe of the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

  For example, in the present embodiment, the metal intermediate layer 3 is configured as a three-layer tube in which the inner layer 2 and the outer layer 3 are disposed one by one on the inner peripheral surface and the outer peripheral surface of the metal intermediate layer 3, but it is necessary to be limited to this. Alternatively, a multilayer pipe in which a plurality of thermoplastic resin layers are disposed on the inner and outer peripheral sides of the metal intermediate layer 3 may be used.

  In addition to the metal intermediate layer 3, another intermediate layer made of metal may be provided. In that case, the metal layers may be adjacent to each other (may be stacked so as to face each other), or may be disposed so as to sandwich another layer between the metal layers. In that case, each metal layer does not need to be the same material, and may be formed with a different material.

  Similarly, in the thermoplastic resin layer in the present embodiment, the inner layer 2 and the outer layer 4 are formed of the same thermoplastic resin, but need not be formed of the same material, and may be formed of different materials. . Moreover, when comprised from a some thermoplastic resin layer, each layer may be formed with the same raw material, and may be formed with a different raw material.

  Moreover, it is good also as a multilayer tube with a heat insulating material by arrange | positioning 3 mm or less heat insulating material (heat insulating material) in the outer peripheral surface of the multilayer tube 1 which concerns on this embodiment. In this case, since the inner layer 2 and the outer layer 4 formed of thermoplastic resin are respectively disposed on the inner side and the outer side of the metal intermediate layer 3, even if the thickness of the heat insulating material is reduced, the fluid flowing inside is sufficiently kept warm. can do. In addition, by reducing the thickness of the heat insulating material, the outer diameter of the multilayer tube with the heat insulating material does not become too large, so that it is easy to bend and handle at the construction site.

  In this case, examples of the heat insulating material include foamed thermoplastic resins such as foamed crosslinked polyethylene, foamed polypropylene, foamed acrylic resin, and foamed urethane resin, and glass wool.

The partially cut-out cross-sectional perspective view of the multilayer tube which concerns on this embodiment is shown. The expansion longitudinal cross-sectional view of the multilayer tube concerning the embodiment is shown. The schematic block diagram of the manufacturing apparatus of the multilayer tube concerning the embodiment is shown. The longitudinal cross-sectional view of the pipe joint and triple-layer pipe joined with the conventional pipe outer peripheral surface is shown. The longitudinal cross-sectional view of the conventional pipe joint for three-layer pipes and a three-layer pipe is shown.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Multilayer pipe, 2 ... Inner layer, 3 ... Metal intermediate layer, 4 ... Outer layer, 5 ... Adhesive (adhesive layer), 6 ... Mark, 20 ... Manufacturing apparatus, 21 ... Supply bobbin, 22 ... Pretreatment tank, 23 ... Cutting device, 24 ... U-shaped shaping device, 25 ... Tubular shaping device, 26 ... Welding device, 27 ... Thermoplastic extrusion mold, 271 ... Horizontal cylindrical passage portion, 272 ... Vertical passage portion, 273 ... Box portion DESCRIPTION OF SYMBOLS 274 ... Discharge part, 28 ... Extrusion device, 29 ... Cooling tank, 30 ... Printing device, 31 ... Cutting device, L ... Predetermined length, W ... Predetermined space | interval

Claims (6)

  In a multilayer tube composed of a plurality of layers including a metal intermediate layer, the metal intermediate layer is formed to have a predetermined length in the axial direction and is intermittently disposed at a predetermined interval. Multi-layer pipe to do.   The multilayer pipe according to claim 1, wherein the metal intermediate layer is formed such that the predetermined length is longer than the predetermined interval.   The multilayer pipe according to claim 1 or 2, wherein the predetermined interval is 10 mm or more and 10,000 mm or less.   The multilayer pipe according to any one of claims 1 to 3, wherein the metal intermediate layer is made of aluminum.   The multilayer pipe according to claim 1, wherein the metal intermediate layer is formed of copper or SUS.   The multilayer tube according to any one of claims 1 to 5, wherein a heat insulating material having a thickness of 3 mm or less is further disposed on the outer peripheral surface of the outermost layer.

Images