Piping material

Abstract

In order to provide a piping material connectable to another piping material by means of a structure in which a part of the piping material is freely bent and an end processed part is pressed by a nut, this piping material comprises: a flexible tube part (10) that has a bellows tube (11) having a bellows-like tube wall (11a) and a tube end (11b) fixed to an intermediate tube part (30); a flared tube part (20) that has a tube body (21) which is formed with a flared part (24) having an outer diameter increasing toward a tip (23a) side and an end processed part (23) having a seal part (25) capable of contacting the other piping material, and which has a proximal end (21a) fixed to the intermediate tube part (30), and a nut (22) through which the tube body (21) penetrates and which presses the end processed part (23) against the other piping material; and the intermediate tube part (30) that is disposed between the flexible tube part (10) and the flared tube part (20), has a first opening (31a) with an opening diameter set to a size capable of fixing the flexible tube part (10), and a second opening (32a) with an opening diameter set to a size capable of fixing the flared tube part (20).

Description

Piping materials

[0001] The present disclosure relates to piping materials.

[0002] Conventionally, a piping material has been known in which a coupling member is joined by welding or the like to one end of a flexible pipe whose pipe wall is formed in a bellows shape and which can be freely bent (see, for example, Patent Document 1). Also known is a flared pipe having a processed end portion formed thereon for connection to another piping material (see, for example, Patent Document 2). This flared pipe has a nut passing through it that presses the processed end portion against the other piping material.

[0003] JP-A No. 8-226584 JP-A No. 11-166674

[0004] To connect a flexible pipe to another piping material using a nut to press the end of the flared pipe, it is necessary to connect the flexible pipe to a conventional flared pipe. Therefore, for example, a method is considered in which end portions are formed on both ends of the flared pipe and one end portion is connected to a coupling member joined to the flexible pipe. In this case, a nut is screwed onto the coupling member.

[0005] Furthermore, to change the routing direction of piping materials, the flare pipe may be bent after connecting the flexible pipe and the flare pipe. In this case, if the end-processed portion is connected to a coupling member joined to the flexible pipe, the bending process must be performed while avoiding the end-processed portion and the nut connected to the coupling member. In other words, the processing allowance for the bending process must be at least the axial length of the nut. This increases the overall length of the flare pipe, resulting in increased costs and poor layout flexibility. Furthermore, to change the routing direction of the flare pipe without bending it, an elbow coupling can be considered. However, this increases the number of parts, which leads to increased costs and weight.

[0006] Another possible method is to butt-weld the other end of the flared pipe, which does not have a terminal processing portion, to the flexible pipe itself. In this case, the inner and outer diameters of the flared pipe and the flexible pipe must be large enough to be welded to each other. Furthermore, the materials of the flared pipe and the flexible pipe must also be weldable to each other. This results in a problem of limited freedom in selecting the size and material of the flared pipe and the flexible pipe.

[0007] The present disclosure has been made in light of the above-mentioned problems, and provides a piping material that can be connected to other piping materials by a structure in which a portion can be freely bent and the end processed portion is pressure-welded with a nut.

[0008] In order to achieve the above object, the piping material of the present disclosure comprises a first pipe section that can be freely bent, a second pipe section that has a terminal processed section for connecting to another piping material, and a third pipe section that is arranged between the first pipe section and the second pipe section, wherein the first pipe section has a first pipe section main body whose pipe end is fixed to the third pipe section and whose pipe wall is formed in a bellows shape, the second pipe section has a second pipe section main body whose base end is fixed to the third pipe section and whose tip end is formed with the terminal processed section, and a nut through which the second pipe section main body passes and that screws into the other piping material to press the terminal processed section against the other piping material, the terminal processed section has a flared section whose outer diameter gradually increases toward the tip side, and a sealing section that can come into contact with the other piping material, and the third pipe section has an opening on one end side that has a diameter set to a size that can fix the first pipe section, and an opening on the other end side that has a diameter set to a size that can fix the second pipe section.

[0009] As a result, the piping material of the present disclosure can be connected to other piping materials by a structure in which a portion thereof can be freely bent and the terminal processed portion is pressure-welded with a nut.

[0010] Fig. 2 is an external view showing a piping material of embodiment 1. Fig. 3 is an enlarged cross-sectional view of part A of Fig. 1. Fig. 4 is an enlarged view explaining a main part of a state in which the piping material is connected to another piping material. Fig. 5 is an enlarged cross-sectional view showing a main part of a piping material of a first modified example. Fig. 6 is an external view showing a piping material of a second modified example.

[0011] An embodiment of the piping material of the present disclosure will be described below with reference to the drawings.

[0012] The piping material 1 of the first embodiment is applied, for example, to a fuel supply system for an automobile that supplies fuel to an engine (internal combustion engine) mounted on the automobile. The piping material 1 may be used as piping for a factory or plant to connect vibrating devices such as mobile devices and pumps. The piping material 1 may also be used for gas or water piping not only for industrial use but also for household use. Furthermore, the piping material 1 may be used for the intermediate portion of an automobile exhaust pipe, vacuum piping for semiconductor manufacturing equipment, sprinkler connection parts for fire extinguishing piping as fire protection equipment, etc. Fluids such as liquids or gases, such as gasoline, hydrogen, and water, flow through the interior of the piping material 1.

[0013] 1, the piping material 1 includes a flexible pipe section 10 (first pipe section), a pair of flared pipe sections 20 (second pipe sections), and a pair of intermediate pipe sections 30 (third pipe sections). Here, the flexible pipe section 10 is disposed at the center of the piping material 1 in the axial direction, and the pair of flared pipe sections 20 are disposed at both ends of the piping material 1. The pair of intermediate pipe sections 30 are disposed between the flexible pipe section 10 and the flared pipe sections 20.

[0014] In the piping material 1 of the first embodiment, the pair of flared pipe sections 20 have the same structure, and the pair of intermediate pipe sections 30 have the same structure. Therefore, in this specification, the flexible pipe section 10, one flared pipe section 20, and one intermediate pipe section 30 will be described.

[0015] The flexible pipe 10 can bend freely and flexibly change its axial direction. As shown in Fig. 2, the flexible pipe 10 includes a bellows tube 11 (first pipe body) and a braid 12 that covers the bellows tube 11.

[0016] The bellows tube 11 is formed from a thin-walled metal tube with both ends open. The bellows tube 11 has a tube wall 11a formed in a bellows shape along its entire length. The term "bellows shape" refers to a shape in which peaks 11v and valleys 11m are alternately arranged along the axial direction. The axial direction of the bellows tube 11 can be freely changed by elastic deformation of the valleys 11m. The bellows tube 11 is also formed from a material that can be welded to the intermediate tube portion 30, such as low-strength stainless steel SUS316L.

[0017] The bellows tube 11 has a tube end 11b butt-welded to one end 31 of the intermediate tube portion 30. That is, an annular weld mark S is formed between the tube end 11b of the bellows tube 11 and one end 31 of the intermediate tube portion 30. Here, "butt welding" is a joining method in which base materials are butted together and at least one of the base materials is melted to join them on the same plane.

[0018] That is, the tube end 11b of the bellows tube 11 abuts against the periphery of the first opening 31a of the intermediate tube portion 30. The abutting portion of the bellows tube 11 and the periphery of the first opening 31a are both fused and integrated. Note that the "first opening 31a" refers to the opening at one end 31 of the intermediate tube portion 30. It is also desirable that the tube end 11b of the bellows tube 11 be cut at the position of the ridge 11v to facilitate welding.

[0019] The braid 12 is a cylindrical member formed by weaving metal wires or strips (such as SUS316L) into a cylindrical shape. The braid 12 is flexible enough to bend freely in response to the bending deformation of the bellows tube 11. When the bellows tube 11 is inserted into the braid 12, the braid 12 completely covers the outer circumferential surface of the bellows tube 11. The inner diameter of the braid 12 is set to be slightly larger than the maximum outer diameter of the bellows tube 11 (the outer diameter at the position of the ridge 11v). A small gap may be formed between the braid 12 and the bellows tube 11, or the braid 12 and the bellows tube 11 may come into contact with each other. The braid 12 is also axially longer than the bellows tube 11. Therefore, the end 12a of the braid 12 protrudes axially beyond the end 11b of the bellows tube 11. The intermediate tube portion 30 fixed to the bellows tube 11 has one end portion 31 and a part of a small diameter region 33 (described later) covered by the braid 12 .

[0020] The end 12a of the blade 12 is fixed to the small diameter region 33 of the intermediate tubular portion 30 by crimping via the collar member 13. That is, the collar member 13 is attached to the outside of the end 12a of the blade 12. The end 12a of the blade 12 is compressed by pressing the collar member 13, and a compressed portion 12b is formed between the intermediate tubular portion 30 and the collar member 13. The compressed portion 12b is thinner than the general portion of the blade 12 (the portion not covered by the collar member 13). The compressed portion 12b is also harder than the general portion of the blade 12.

[0021] The collar member 13 is a metal strip-shaped member that is wrapped around the end portion 12a of the blade 12. This gives the collar member 13 a ring shape that surrounds the small diameter region 33 via the blade 12.

[0022] As shown in FIG. 2, the flared pipe section 20 has a pipe body 21 (second pipe section body) and a nut 22 through which the pipe body 21 passes.

[0023] The pipe body 21 is formed of a metallic cylindrical pipe with both ends open. The pipe body 21 has a straight pipe shape extending straight from one end, the base end 21a, to the end processed portion 23 formed at the other end (tip end). The pipe body 21 is formed of, for example, stainless steel for high-pressure hydrogen (austenitic stainless steel) which has higher strength than SUS316L. Note that stainless steel for high-pressure hydrogen can improve the strength while reducing the thickness and weight of the pipe body 21.

[0024] The base end 21a of the pipe body 21 is brazed to the other end 32 of the intermediate pipe section 30. In other words, a filler material F (copper in this case) is interposed between the base end 21a of the pipe body 21 and the other end 32 of the intermediate pipe section 30. Here, "brazing" is a joining method in which molten filler material is poured between the base materials to be joined and the base materials are joined via the filler material. The filler material has a lower melting point than the base materials. The molten filler material penetrates into gaps in the base materials and blends with them through wetting and capillary action. For this reason, the base materials do not melt during brazing.

[0025] That is, the base end 21a of the pipe body 21 is inserted into the second opening 32a. The filler material F poured between the pipe body 21 and the intermediate pipe section 30 is joined to the outer circumferential surface of the pipe body 21 and the inner circumferential surface 30a of the intermediate pipe section 30. The "second opening 32a" refers to the opening at the other end 32 of the intermediate pipe section 30.

[0026] The end processed portion 23 is a portion for connecting the piping material 1 to another piping material. The end processed portion 23 is formed by curving the outer peripheral surface of the pipe body 21 in a convex arc shape and tapering toward the tip 23a. The end processed portion 23 has a flared portion 24 and a sealing portion 25.

[0027] The flared portion 24 is a portion whose outer diameter gradually increases toward the tip 23 a. The flared portion 24 is located on the base end 21 a side of the end processed portion 23, and is configured by an inclined surface that gradually increases the outer diameter of the end processed portion 23 toward the tip 23 a.

[0028] The sealing portion 25 is formed closer to the tip 23a than the flare portion 24 and is the portion that comes into contact with other piping materials. The sealing portion 25 is located on the tip 23a side of the end processed portion 23 and is configured by an inclined surface that gradually reduces the outer diameter of the end processed portion 23 toward the tip 23a.

[0029] The "other piping material" refers to a tubular member to which the piping material 1 is connected, such as a pipe (tube) or a cylindrical boss protruding from the circumferential surface of a pipe.

[0030] The nut 22 is a bag-shaped nut with a two-face width (typically hexagonal) outer shape, through which the pipe body 21 passes. The nut 22 has an opening 22a at one end through which other piping material can be inserted, and a through-hole 22b at the other end through which the pipe body 21 passes. The nut 22 also has a pressing portion 22c around the through-hole 22b. Furthermore, the inner peripheral surface of the nut 22 is formed with a threaded portion 22d that screws onto a threaded portion formed on other piping material.

[0031] Here, the inner diameter W1 of the through hole 22b is set to a dimension smaller than the maximum outer diameter W2 of the end-machined portion 23 and larger than the outer diameter R3 of the pipe body 21. The inner diameter W3 of the nut 22 and the opening diameter W4 of the opening 22a are set to a dimension larger than the maximum outer diameter W2 of the end-machined portion 23 and the outer diameter R3 of the pipe body 21.

[0032] The nut 22 is positioned between the end processed portion 23 and the base end 21a by inserting the pipe body 21 into the through hole 22b with the opening 22a facing the end processed portion 23. The nut 22 is movable along the axial direction of the pipe body 21. The pressing portion 22c surrounding the through hole 22b interferes with the flared portion 24 of the end processed portion 23, preventing the nut 22 from coming off the pipe body 21.

[0033] The piping material 1 is connected to another piping material by pressing the end processed portion 23 to the other piping material with the nut 22. That is, FIG. 3 shows an enlarged cross-sectional view of the essential parts when the piping material 1 is connected to the other piping material (hereinafter referred to as "pipe 100"). The pipe 100 has an opening 101 at the end to which the piping material 1 is connected, with an inner circumferential surface 101a thereof sloping inward, forming a mortar shape. The maximum opening diameter of the opening 101 is set to a size that allows the end processed portion 23 to be inserted. The outer diameter of the pipe 100 is set to a size that allows it to be inserted into the nut 22. The outer circumferential surface of the pipe 100 is formed with a threaded portion 102 that can be threaded onto the threaded portion 22d of the nut 22.

[0034] As shown in FIG. 3 , when the piping material 1 is connected to the pipe 100, the pipe body 21 of the flared pipe section 20 and the pipe 100 are arranged coaxially. Then, the end processed section 23 is inserted into the opening 101 of the pipe 100, and the seal section 25 comes into contact with the inner circumferential surface 101a of the opening 101. The pipe 100 is also inserted into the nut 22, and the threaded section 22d and the threaded section 102 are threadedly engaged with each other. At this time, as the nut 22 is tightened, the pressing section 22c presses the flared section 24 along the axial direction. Then, the seal section 25 of the end processed section 23 is pressed against the inner circumferential surface 101a of the opening 101. As a result, the seal section 25 is pressed against the inner circumferential surface 101a of the opening 101 of the pipe 100, and the piping material 1 and the pipe 100 are connected in an airtight state.

[0035] As shown in Figures 2 and 4, the intermediate pipe portion 30 is a cylindrical metal pipe with both ends open. The intermediate pipe portion 30 is formed of a straight pipe that extends in a straight line. The intermediate pipe portion 30 is formed of a material (e.g., SUS316L) to which the bellows tube 11 of the flexible pipe portion 10 can be welded. The flexible pipe portion 10 is fixed to one end 31 of the intermediate pipe portion 30, and the flared pipe portion 20 is fixed to the other end 32. The intermediate pipe portion 30 has a small-diameter region 33 formed in an axially intermediate portion thereof, the small-diameter region 33 having a smaller outer diameter than the both end portions 31, 32. The outer diameter of the one end portion 31 and the other end portion 32 are set to be the same size.

[0036] The opening diameter R1 of the opening (first opening 31a) on one end 31 side of the intermediate pipe portion 30 is approximately the same as or equal to the minimum inner diameter R4 (see FIG. 2) of the corrugated tube 11. That is, the opening diameter R1 of the first opening 31a of the intermediate pipe portion 30 is set to a size that allows the flexible pipe portion 10 to be fixed. In other words, the size of the opening diameter R1 is set according to the minimum inner diameter R4 of the corrugated tube 11 of the flexible pipe portion 10. Furthermore, the wall thickness T1 of the peripheral portion of the first opening 31a of the intermediate pipe portion 30, i.e., the width of the end face of one end 31, is set to a thickness that allows the flexible pipe portion 10 to be butt-welded.

[0037] Furthermore, the opening diameter R2 of the opening (second opening 32a) on the other end 32 side of the intermediate pipe section 30 is slightly larger than the outer diameter R3 (see FIG. 2 ) of the pipe body 21. Therefore, the base end 21a of the pipe body 21 can be inserted into the second opening 32a. In other words, the opening diameter R2 of the second opening 32a of the intermediate pipe section 30 is set to a size that allows the flared pipe section 20 to be fixed. Therefore, the size of the opening diameter R2 is set according to the outer diameter R3 of the pipe body 21 of the flared pipe section 20.

[0038] The small diameter region 33 only needs to have a smaller outer diameter than the end portions 31, 32, and the axial length and size of the outer diameter can be determined arbitrarily. However, the end portion 12a of the blade 12 is fixed to the small diameter region 33 by crimping via the collar member 13. For this reason, it is preferable that the axial length of the small diameter region 33 be longer than the axial length of the collar member 13. Furthermore, it is preferable that the difference ΔT2 between the outer diameter of the end portions 31, 32 of the intermediate tube portion 30 and the outer diameter of the small diameter region 33 be larger than the thickness of the portion of the blade 12 crimped by the collar member 13.

[0039] A tapered surface 34 and a step portion 35 are formed on the inner peripheral surface 30a of the intermediate pipe portion 30. The tapered surface 34 is formed on one end portion 31 of the intermediate pipe portion 30. The step portion 35 is formed on the other end portion 32 of the intermediate pipe portion 30.

[0040] The tapered surface 34 gradually expands the inner diameter of the intermediate tube portion 30 from the second opening 32a toward the first opening 31a, so that the first opening 31a has a predetermined opening diameter R1. The axial length of the tapered surface 34 can be freely set.

[0041] When the inner diameter of the intermediate pipe portion 30 is equal to the opening diameter R1, the tapered surface 34 is not formed. When the inner diameter of the intermediate pipe portion 30 is larger than the opening diameter R1, the tapered surface 34 gradually reduces the inner diameter of the intermediate pipe portion 30 from the second opening 32a side toward the first opening 31a.

[0042] The step portion 35 reduces the inner diameter of the intermediate pipe section 30 in a stepped manner compared to the opening diameter R2 of the second opening 32a, forming a step surface 35a facing the second opening 32a. When the pipe body 21 of the flared pipe section 20 is inserted into the intermediate pipe section 30, the base end 21a of the pipe body 21 abuts against the step surface 35a (see FIG. 2). This positions the pipe body 21 in the axial direction. The axial length from the second opening 32a to the step surface 35a can be determined arbitrarily, but is preferably a length that allows stable brazing of the pipe body 21.

[0043] When the inner diameter of the intermediate pipe portion 30 is equal to or larger than the opening diameter R2, the step portion 35 is formed by an annular plate protruding from the inner peripheral surface 30a of the intermediate pipe portion 30.

[0044] To manufacture the piping material 1 of the first embodiment, first, a cylindrical pipe that will become the pipe body 21 of the flared pipe section 20 is cut to a predetermined length. Next, both end faces of the cut cylindrical pipe are machined so that they are parallel to each other. Next, one end (base end 21a) of the cylindrical pipe is inserted into the second opening 32a of the pre-formed intermediate pipe section 30. Then, copper as a filler material F is poured between the one end (base end 21a) of the cylindrical pipe and the intermediate pipe section 30. As a result, the filler material F is interposed between the cylindrical pipe and the intermediate pipe section 30. Then, the filler material F fits to the cylindrical pipe and the intermediate pipe section 30, and the cylindrical pipe and the intermediate pipe section 30 are joined by brazing.

[0045] After the cylindrical pipe that will become the pipe main body 21 and the intermediate pipe section 30 are joined, the nut 22 is inserted from the other end (tip) of the cylindrical pipe. At this time, the cylindrical pipe is inserted into the nut 22 from the outside of the through-hole 22b. Then, the other end (tip) of the cylindrical pipe is pressed to form the end processed section 23. As a result, the flared pipe section 20 is manufactured.

[0046] Thereafter, the pipe end portion 11b of the corrugated tube 11 of the pre-formed flexible pipe portion 10 is abutted against the periphery of the first opening 31a of the intermediate pipe portion 30. Then, the abutting portion between the corrugated tube 11 and the intermediate pipe portion 30 is melted. As a result, a weld mark S is formed between the corrugated tube 11 and the intermediate pipe portion 30. In other words, the corrugated tube 11 and the intermediate pipe portion 30 are joined by welding (butt welding).

[0047] At this time, the corrugated tube 11 is inserted into the braid 12 in advance. During welding of the corrugated tube 11 and the intermediate tube portion 30, the braid 12 is moved axially to a position where it does not interfere with welding. After the corrugated tube 11 is welded to the intermediate tube portion 30, the braid 12 is moved axially to a position where it covers the small diameter region 33 of the intermediate tube portion 30. Then, the collar member 13 is wrapped around the end portion 12a of the braid 12. Next, the periphery of the collar member 13 is pressed. As a result, the portion of the end portion 12a of the braid 12 between the intermediate tube portion 30 and the collar member 13 is compressed, forming a compressed portion 12b. As a result, the end portion 12a of the braid 12 has a compressed portion 12b between the intermediate tube portion 30 and the collar member 13. In other words, the end portion 12a of the braid 12 is crimped and fixed to the intermediate tube portion 30 via the collar member 13. The piping material 1 is manufactured in this manner.

[0048] The function of the piping material 1 of the first embodiment will be explained as follows.

[0049] That is, the piping material 1 comprises a flexible pipe section 10, a flared pipe section 20, and an intermediate pipe section 30. The flexible pipe section 10 is bendable. The flared pipe section 20 has a terminal processed section 23 for connecting to other piping materials. The intermediate pipe section 30 is disposed between the flexible pipe section 10 and the flared pipe section 20.

[0050] The flexible pipe section 10 has a bellows pipe 11 whose pipe end 11b is fixed to an intermediate pipe section 30 and whose pipe wall 11a is formed in a bellows shape. The flared pipe section 20 has a pipe main body 21 and a nut 22. The pipe main body 21 has a base end 21a fixed to the intermediate pipe section 30 and a terminal processed portion 23 formed at its tip end. The pipe main body 21 passes through the nut 22 and screws onto another piping material to press the terminal processed portion 23 against the other piping material. The terminal processed portion 23 has a flared portion 24 whose outer diameter gradually increases toward the tip end 23a and a seal portion 25 that can come into contact with the other piping material.

[0051] Furthermore, in the piping material 1, the opening diameter R1 of the opening (first opening 31a) on one end 31 side of the intermediate pipe section 30 is set to a size that allows the flexible pipe section 10 to be fixed. Also, in the piping material 1, the opening diameter R2 of the opening (second opening 32a) on the other end 32 side is set to a size that allows the flared pipe section 20 to be fixed.

[0052] Therefore, a portion of the piping material 1 can be freely bent, and can be connected to other piping materials by crimping the end processed portion 23 with the nut 22. In other words, the piping material 1 can function as a flexible pipe that can be freely bent, and as a flared pipe that can be connected to other piping materials by crimping the end processed portion 23 with the nut 22.

[0053] Furthermore, in the piping material 1, the nut 22 is not disposed between the flared pipe section 20 and the intermediate pipe section 30. Therefore, in the piping material 1, even when bending the pipe main body 21, for example, it is not necessary to add the axial length of the nut 22 to the processing allowance for the bending process. Moreover, by bending the pipe main body 21, the piping material 1 can change the routing direction of the flared pipe section 20 without using an elbow joint.

[0054] As a result, the piping material 1 can bend the flared pipe section 20 without adding the axial length of the nut 22 to the processing allowance for bending. Therefore, the piping material 1 can suppress increases in cost and deterioration of layout flexibility. Furthermore, since the piping material 1 can be bent while suppressing increases in cost, etc., there is no need to use an elbow joint. As a result, the piping material 1 does not require a thick elbow joint to ensure strength. Furthermore, the piping material 1 can reduce costs, reduce weight, and improve layout flexibility.

[0055] Furthermore, the piping material 1 allows the size and material of the flexible pipe section 10 and the flared pipe section 20 to be freely set by adjusting the outer diameter, inner diameter, and material of the intermediate pipe section 30. As a result, the size and material of the flexible pipe section 10 and the flared pipe section 20 of the piping material 1 can be designed according to the type, temperature, pressure, etc. of the fluid flowing inside the piping material 1. Thus, the piping material 1 becomes capable of carrying, for example, high-temperature, high-pressure fluids.

[0056] In this way, the piping material 1 has the functions of both a flexible pipe and a flare pipe, suppresses increases in cost and deterioration of layout, and provides a high degree of freedom in selecting sizes and materials.

[0057] In the piping material 1, a filler material F is interposed between the base end 21 a of the pipe body 21 and the other end 32 of the intermediate pipe section 30. In other words, the base end 21 a of the pipe body 21 of the flared pipe section 20 is brazed to the other end 32 of the intermediate pipe section 30.

[0058] As a result, the piping material 1 can join the pipe body 21 or the intermediate pipe section 30 of the flared pipe section 20 even if they are formed from materials that are not suitable for welding. Furthermore, the pipe body 21 and the intermediate pipe section 30 can be joined even if they are made from different materials. Therefore, the piping material 1 can further increase the freedom in selecting materials for the flared pipe section 20 and the intermediate pipe section 30. In other words, the piping material 1 allows for the selection of materials that can improve strength while reducing the thickness and weight of the pipe body 21. Furthermore, in the piping material 1, the brazed joint (the portion where the filler material F is interposed) is in an annealed state. Therefore, the piping material 1 can obtain the benefits of annealing.

[0059] Furthermore, the piping material 1 allows the processing allowance when bending the pipe body 21 of the flared pipe section 20 to be set based on the edge (second opening 32a) of the other end 32. Therefore, the piping material 1 makes it possible to shorten the distance from the pipe end 11b of the flexible pipe section 10 to the bending position formed in the pipe body 21 of the flared pipe section 20.

[0060] Furthermore, in the piping material 1, the corrugated tube 11 and the intermediate tube portion 30 of the flexible tube portion 10 are formed of materials that can be welded to each other. A weld mark S is formed between the tube end portion 111b of the corrugated tube 11 and one end portion 31 of the intermediate tube portion 30. In other words, the tube end portion 11b of the corrugated tube 11 is butt-welded to one end portion 31 of the intermediate tube portion 30.

[0061] As a result, the piping material 1 can directly integrate the bellows tube 11 and the intermediate tube portion 30 without using any joint parts, and the piping material 1 can suppress increases in cost and weight.

[0062] Furthermore, in the piping material 1, the flexible pipe section 10 has a braid 12. The braid 12 covers the bellows tube 11 and is tubular and longer than the bellows tube 11. The braid 12 has flexibility that allows it to follow the bending deformation of the bellows tube 11. The intermediate pipe section 30 has a small-diameter region 33 in the axial middle, which has an outer diameter smaller than both end sections 31, 32. One end section 31 and a portion of the small-diameter region 33 of the intermediate pipe section 30 are covered by the braid 12. A collar member 13 is attached to the end section 12a of the braid 12, surrounding the small-diameter region 33. The end section 12a of the braid 12 has a compressed section 12b between the intermediate pipe section 30 and the collar member 13. In other words, the end section 12a of the braid 12 is crimped and fixed to the small-diameter region 33 via the collar member 13.

[0063] As a result, the piping material 1 can prevent the bellows tube 11 from being pressurized from the inside and stretched due to the flow of fluid. In other words, the piping material 1 can improve the pressure resistance of the flexible pipe section 10. Furthermore, the piping material 1 can protect the bellows tube 11 from external impacts.

[0064] Furthermore, because the end 12a of the blade 12 is fixed by crimping to the small diameter region 33 of the intermediate pipe portion 30, the piping material 1 can suppress axial displacement of the collar member 13. Furthermore, the piping material 1 can suppress a step between the end 12a of the blade 12 and the outer surface of the intermediate pipe portion 30. Furthermore, the piping material 1 can prevent the end 12a of the blade 12 and the collar member 13 from getting caught on external parts, etc.

[0065] Although the piping material of the present disclosure has been described above, the specific configuration is not limited to that disclosed herein. The piping material of the present disclosure is permitted to be modified or added to in design as long as it does not deviate from the gist of the invention according to each claim.

[0066] In the piping material 1 of the first embodiment, the braid 12 covering the bellows tube 11 is fixed by crimping via a collar member 13. However, the braid 12 does not necessarily have to be fixed by crimping, as in the piping material 1A of the first modified example, a portion of which is shown in Figure 4.

[0067] That is, the piping material 1A of the first modified example comprises a flexible pipe section 40, a pair of flared pipe sections 50, and a pair of intermediate pipe sections 60. Here, Fig. 4 shows one end of the flexible pipe section 40, and one intermediate pipe section 60 and one flared pipe section 50 connected thereto. However, although not shown, the piping material 1A has the other flared pipe section 50 connected to the other end of the flexible pipe section 40 via the other intermediate pipe section 60. Note that the intermediate pipe section 60 and the flared pipe section 50 do not have to be connected to the other end of the flexible pipe section 40.

[0068] The flexible tube section 40 includes a bellows tube 41 abutted against the intermediate tube section 60, and a braid 42 covering the bellows tube 41. A collar member 43 is attached to the end 42a of the braid 42. The collar member 43 covers the entire outer periphery of the end 42a of the braid 42. The collar member 43 may be a metal strip-shaped member wrapped around the end 42a of the braid 42, or may be a cylindrical tube into which the end 42a is inserted.

[0069] The intermediate tube portion 60 is a cylindrical tube with both ends open. Here, the outer diameter of the intermediate tube portion 60 of the first modified example is constant over the entire length. However, the outer diameter of the intermediate tube portion 60 may be different between the both ends and the middle portion, similar to the intermediate tube portion 30 of the first embodiment.

[0070] The diameter of the opening (first opening 61a) on one end 61 of the intermediate pipe section 60 is approximately the same as or the same as the minimum inner diameter of the bellows tube 41, as with the intermediate pipe section 30 of embodiment 1. The width of the end face of one end 61 of the intermediate pipe section 60 is set to a thickness that allows the flexible pipe section 40 to be butt-welded. The diameter of the opening (second opening 62a) on the other end 62 of the intermediate pipe section 60 is slightly larger than the outer diameter of the pipe main body 51 of the flared pipe section 50. The tip of the pipe main body 51 is formed with a terminal processed portion 53 similar to that of embodiment 1. The flared pipe section 50 also has a nut 52 through which the pipe main body 51 passes.

[0071] A step portion 65 is formed on the inner peripheral surface 60a of the intermediate pipe portion 60. The step portion 65 makes the inner diameter of the intermediate pipe portion 60 smaller than the opening diameter of the second opening 62a in a stepped manner, and forms a step surface facing the second opening 62a.

[0072] In the intermediate pipe portion 60 of the first modified example, the inner diameter of the intermediate pipe portion 60 matches the opening diameter of the first opening 61 a. Therefore, a tapered surface is not formed on the inner circumferential surface 60 a of the intermediate pipe portion 60. However, in order to match the inner diameter of the inner circumferential surface 60 a of the intermediate pipe portion 60 with the opening diameter of the first opening 61 a, a tapered surface may be formed on the inner circumferential surface 60 a.

[0073] The pipe body 51 of the flared pipe section 50 is brazed to the inner peripheral surface 60a of the intermediate pipe section 60. In other words, a filler material F is interposed between the outer peripheral surface of the pipe body 51 and the inner peripheral surface 60a of the intermediate pipe section 60.

[0074] On the other hand, the end 41c of the bellows tube 41 is butt-welded to the periphery of the first opening 61a of the intermediate tube portion 60. That is, a ring-shaped weld mark S is formed between the tube end portion 41b of the bellows tube 41 and one end portion 61 of the intermediate tube portion 60.

[0075] Furthermore, the terminals 42c of the blades 42 and the terminals 43c of the collar member 43 are aligned in the axial direction. The terminals 42c of the blades 42 and the terminals 43c of the collar member 43 are fixed to the outer circumferential surface 60b of the intermediate tubular portion 60 by welding (fillet welding in this case). In other words, outer weld marks S1 are formed between the terminals 42c of the blades 42 and the terminals 43c of the collar member 43 and the intermediate tubular portion 60.

[0076] 4, the terminal 42c of the blade 42 and the terminal 43c of the collar member 43 are also aligned in the axial direction with the terminal 41c of the bellows tube 41. However, it is sufficient that the terminal 42c of the blade 42 and the terminal 43c of the collar member 43 are aligned in the axial direction. In other words, the terminal 42c of the blade 42 and the terminal 43c of the collar member 43 do not need to be aligned in the axial direction with the terminal 41c of the bellows tube 41.

[0077] Furthermore, the terminal 42c of the blade 42 and the terminal 43c of the collar member 43 may protrude in the axial direction beyond the terminal 41c of the bellows tube 41. In other words, as in the piping material 1 of the first embodiment, one end 61 of the intermediate tube portion 60 may be covered by the blade 42 and the collar member 43.

[0078] As a result, in the piping material 1A of the first modified example, the collar member 43 can reinforce the joint between the flexible pipe section 40 and the intermediate pipe section 60. In other words, when a bending force (a force bending in the axial direction) acts on the piping material 1A, the bending force is concentrated on the weld mark S created by butt-welding the flexible pipe section 40 and the intermediate pipe section 60. In response to this, the collar member 43 suppresses deformation of the end of the bellows tube 41 and can prevent the force from concentrating on the weld mark S. Note that the end 42c of the blade 42 is welded and fixed to the intermediate pipe section 60 integrally with the collar member 43, thereby suppressing misalignment.

[0079] Furthermore, in the piping material 1 of embodiment 1, the flexible pipe portion 10 has a braid 12 that covers the bellows tube 11. However, the piping material 1 does not necessarily have to have the braid 12. That is, the bellows tube 11 may be exposed, as in the piping material 1B of the second modified example shown in Fig. 5. Note that if the braid 12 is not included, the intermediate pipe portion 30 does not need to have a small diameter region 33. That is, the outer diameter of the intermediate pipe portion 30 may be constant along its entire length.

[0080] Furthermore, the bellows tube 11 does not have to be fixed to the intermediate tube portion 30 by welding (butt welding). For example, the bellows tube 11 may be fixed by inserting the tube end 11b into the first opening 31a of the intermediate tube portion 30 and brazing.

[0081] Furthermore, the pipe body 21 of the flared pipe section 20 does not have to be fixed to the intermediate pipe section 30 by brazing. For example, the base end 21 a of the pipe body 21 may be abutted against the periphery of the second opening 32 a of the intermediate pipe section 30, and the abutted portion may be fixed by butt welding.

[0082] Furthermore, the other end 32 of the intermediate pipe section 30 may be inserted into the base end 21a of the pipe body 21 of the flared pipe section 20, and the outer surface of the intermediate pipe section 30 may be brazed and fixed to the inner surface of the pipe body 21.

[0083] Furthermore, in the piping material 1 of embodiment 1, the flexible pipe section 10 is arranged in the center of the axial direction of the piping material 1. However, the flexible pipe section 10 is not necessarily arranged in the center of the entire piping material 1. For example, the flexible pipe section 10 may be arranged at one end of the piping material 1, the flared pipe section 20 may be arranged at the other end of the piping material 1, and the intermediate pipe section 30 may be arranged in the center of the piping material 1. In other words, the piping material 1 only needs to have at least one each of the flexible pipe section 10, the flared pipe section 20, and the intermediate pipe section 30.

[0084] Furthermore, the lengths of the flexible pipe section 10, the flared pipe section 20, and the intermediate pipe section 30 can be set arbitrarily. Furthermore, when the piping material 1 has a pair of flared pipe sections 20, the lengths of one flared pipe section 20 and the other flared pipe section 20 may be different. Furthermore, when the piping material 1 has a pair of intermediate pipe sections 30, the lengths of one intermediate pipe section 30 and the other intermediate pipe section 30 may be different. It is preferable that the length of the intermediate pipe sections 30 is short.

[0085] The end processed portion 23 may have a shape that gradually widens toward the tip 23a. In this case, the flared portion 24 is formed by the outer surface of the end processed portion 23. The seal portion 25 is formed by the inner surface of the end processed portion 23.

[0086] The nut 22 may also be inserted into another piping material, and the threaded portion 22d may be threaded onto a threaded portion formed on the inner circumferential surface of the other piping material. In this case, the threaded portion 22d is formed on the outer circumferential surface of the nut 22.

[0087] Furthermore, the pipe body 21 and the intermediate pipe section 30 of the flared pipe section 20 do not have to be straight pipes that extend straight. That is, the pipe body 21 and the intermediate pipe section 30 may be configured as bent pipes that are appropriately bent. CROSS-REFERENCE TO RELATED APPLICATIONS

[0088] This application claims priority based on Japanese Patent Application No. 2024-125817, filed with the Japan Patent Office on August 1, 2024, the entire disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A piping material comprising a first pipe section that can be bent freely, a second pipe section that has a terminal processed section for connection to another piping material, and a third pipe section that is arranged between the first pipe section and the second pipe section, wherein the first pipe section has a first pipe section main body whose pipe end is fixed to the third pipe section and whose pipe wall is formed in a bellows shape, the second pipe section has a second pipe section main body whose base end is fixed to the third pipe section and whose tip end is formed with the terminal processed section, and a nut through which the second pipe section main body passes and that screws onto the other piping material to press the terminal processed section against the other piping material, the terminal processed section has a flared section whose outer diameter gradually increases toward the tip and a sealing section that can come into contact with the other piping material, and the third pipe section has an opening at one end with a diameter set to a size that can fix the first pipe section, and an opening at the other end with a diameter set to a size that can fix the second pipe section.

2. The piping material according to claim 1, characterized in that a filler material is interposed between the base end of the second pipe body and the other end of the third pipe.

3. The piping material according to claim 1 or 2, wherein the first pipe body and the third pipe body are formed of materials that can be welded to each other, and a weld mark is formed between the pipe end of the first pipe body and one end of the third pipe body.

4. A piping material according to claim 1 or claim 2, characterized in that the first pipe section covers the first pipe section main body, has flexibility that allows it to follow the bending deformation of the first pipe section main body, and has a cylindrical blade that is longer than the first pipe section main body, the third pipe section has a small diameter region in the middle of the axial direction that has an outer diameter smaller than both end sections, the one end section and part of the small diameter region are covered by the end of the blade, and a collar member that surrounds the small diameter region is attached to the end of the blade, and a compression section is formed between the third pipe section and the collar member.

5. A piping material according to claim 1 or claim 2, characterized in that the first pipe section has a cylindrical blade that covers the first pipe section main body and has flexibility that allows it to follow the bending deformation of the first pipe section main body, a collar member is attached to the end of the blade, and external welding marks are formed between the end of the blade and the end of the collar member and the third pipe section.

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