JP2008064187A - Coupling member connecting structure of flexible tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coupling member connecting structure of a flexible tube which can uniform bearing stress caused by calking in the circumferential direction, and improve sealing performance. <P>SOLUTION: Since a tube body 1 is processed in pressing to a connecting member 3 by calking a fixing member 4 by interposing a cylindrical intermediate member 5 made of a metal more elastic than the connecting member 3 between an outer periphery of straight tube portion 1c without being covered by a coating member 2 and an inner periphery of the fixing member 4, pressure difference in circumferential direction generated in the fixing member 4 by the calking can be absorbed by deforming the intermediate member 5, and the bearing stress applied to the straight tube portion 1c and the connecting member 3 can be uniformed in the circumferential direction. This can improve the sealing performance between the straight tube portion 1c and the connecting member 3, and improve durability against high-pressure fluid. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flexible tube used for a gas body having a low gas molecular weight (hydrogen, helium, carbon dioxide, refrigerant gas, etc.) or a high-pressure pipe, such as a refrigerant pipe of a vehicle air conditioner or a hydrogen pipe of a fuel cell vehicle. The present invention relates to a joint member connection structure.

  In recent years, carbon dioxide refrigerant, which is an alternative refrigerant for chlorofluorocarbon, has been used as a refrigerant for vehicle air conditioners. However, carbon dioxide is highly permeable to gases, so in hoses made of organic materials such as rubber and resin. Insufficient permeation resistance to carbon dioxide. Therefore, a metal flexible tube that is impermeable to gas is used for piping through which the carbon dioxide refrigerant flows.

  This type of flexible tube includes a tube main body made of a metal tube formed in an accordion shape and a covering member having a metal reinforcing layer, and is connected to other pipes and devices at the end of the tube main body. It is known that a joint for mounting is attached. This joint consists of a cylindrical joint member and other parts, and is generally joined by welding the joint member to the end of the tube body. In this case, a high sealing performance can be obtained by integrating the tube body and the joint member by welding, but since the welded portion of the tube body is deteriorated by welding heat, durability against external forces such as bending and changes in internal pressure is reduced. There is a problem that the quality is impaired.

Therefore, as a connection structure not using welding, a tube body and a covering member are sandwiched between a joint member and a cylindrical fixing member, and the tube body is crimped to the joint member side by caulking of the fixing member. It is known (for example, refer to Patent Document 1).
JP 2004-52811 A

  By the way, in the joining structure, when the fixing member is caulked, a plurality of circumferential positions of the fixing member are pressed in the radial direction. Therefore, the caulking between the pressing portions becomes insufficient, and the surface pressure due to the caulking is reduced. It could not be made uniform in the circumferential direction. Further, in the connection structure, the straight pipe portion formed at the end of the tube body is extended to the outside of the covering member, and the straight pipe portion is reduced in diameter into the groove of the joint member by the press contact of the fixing member. However, since the tube body is made of a material that is hard and not easily deformed, a vertical rod extending in the axial direction is generated in the straight tube portion of the tube body due to the reduced diameter, and sufficient sealing performance cannot be obtained. It was.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a flexible tube joint that can make the surface pressure by caulking uniform in the circumferential direction and can improve the sealing performance. The object is to provide a member connection structure.

  In order to achieve the above object, the present invention provides a tube main body made of a metal tube formed in a bellows shape excluding the end, a straight pipe formed at the end of the tube main body, and an outer peripheral surface side of the tube main body. A tubular joint member connected to the tube main body, and a cylindrical fixing member for fixing the tube main body to the outer peripheral surface side of the joint member. In the flexible tube joint member connecting structure in which the straight pipe portion is pressure-bonded to the outer peripheral surface of the joint member, between the outer peripheral surface of the straight pipe portion not covered with the covering member and the inner peripheral surface of the fixing member. A cylindrical intermediate member that is disposed and made of a softer metal than the joint member is provided.

  As a result, the intermediate member is pressed against the straight pipe portion of the tube main body while reducing the diameter together with the fixing member, and the inner peripheral surface of the straight pipe portion is crimped to the outer peripheral surface of the joint member. At that time, when the fixing member is pressed at a plurality of locations in the circumferential direction by caulking to reduce the diameter, the radial pressure between the pressing locations is smaller than each pressing location, but the radial pressure of the fixing member is less than that of the joint member. Since the intermediate member made of soft metal is applied to the joint member side, the pressure difference is absorbed by the deformation of the intermediate member, and uniform surface pressure is applied to the straight pipe portion and the joint member in the circumferential direction. That is, the intermediate member formed separately from the fixed member causes the material to flow between each pressing location from the pressing location side of the caulking according to the pressure difference at the time of deformation. On the surface side, the difference in the radial stress is reduced by the flow of the material, and the pressure applied from the intermediate member to the joint member side becomes uniform in the circumferential direction of the intermediate member.

  According to the present invention, since the pressure difference in the circumferential direction generated in the fixing member by caulking can be absorbed by the deformation of the intermediate member, the surface pressure applied to the straight pipe portion and the joint member can be made uniform in the circumferential direction. . Thereby, the sealing performance between a straight pipe part and a coupling member can be improved, and the durability with respect to a high pressure fluid can be improved.

  1 to 5 show a first embodiment of the present invention. FIG. 1 is a partially sectional side view of a flexible tube, FIG. 2 is a sectional view in the direction of arrows AA in FIG. 1, and FIG. The principal part side surface sectional drawing which shows a part of joining process of a flexible tube, and FIG.4 and FIG.5 are principal part side surface sectional drawings of the flexible tube which shows the modification of 1st Embodiment.

  The flexible tube includes a tube body 1 made of a flexible metal tube, a covering member 2 that covers the outer peripheral surface of the tube body 1, a tubular joint member 3 that is connected to an end of the tube body 1, and a tube. It is comprised from the cylindrical fixing member 4 which fixes the edge part of the main body 1 to the outer peripheral surface side of the coupling member 3, and the intermediate member 5 arrange | positioned between the edge part of the tube main body 1, and the fixing member 4. .

  The tube body 1 is made of, for example, a stainless steel (SUS316L) thin tube, and is formed in a bellows shape so as to have flexibility except for an end portion. That is, the peripheral surface of the tube main body 1 is bent in a waveform so that the large diameter portions 1a and the small diameter portions 1b are alternately arranged in the axial direction, and a straight pipe portion 1c is formed at the end thereof. Has been.

  The covering member 2 includes a reinforcing layer 2a formed by braiding a reinforcing wire by blade knitting, an inner rubber layer 2b disposed on the inner peripheral surface side of the reinforcing layer 2a (for example, H-NBR), and an outer periphery of the reinforcing layer 2a. It consists of an outer rubber layer 2c (for example, AEM) disposed on the surface side, and piano wire, SUS304 stainless wire, aramid fiber, polyester fiber, etc. are used as the reinforcing wire of the reinforcing layer 2a.

  The joint member 3 is made of a highly rigid metal such as aluminum (A6063-T83), for example, and another joint part (not shown) is assembled to one end side thereof. The outer peripheral surface of the joint member 3 has an outer diameter substantially equal to the inner diameter of the straight pipe portion 1c of the tube body 1 and is formed so that the outer diameter is uniform in the axial direction. A groove 3a extending in the direction is provided.

  The fixing member 4 is made of a softer metal than the joint member 3, for example, aluminum (A3003-O), and is formed in a cylindrical shape that is longer in the axial direction than the straight pipe portion 1 c of the tube body 1. A plurality of convex portions 4 a formed in an annular shape in the circumferential direction are provided on the inner peripheral surface of the fixing member 4, and the respective convex portions 4 a are arranged at intervals in the axial direction of the fixing member 4. Further, a flange portion 4b extending radially inward is provided at one end in the axial direction of the fixing member 4, and the tip of the flange portion 4b is fitted in the groove 3a of the joint member 3.

  The intermediate member 5 is made of a softer metal than the joint member 3, for example, aluminum (A3003-O), and is formed of a member having a Brinell hardness of 20 HBW to 50 HBW. In this case, the hardness of the intermediate member 5 may be equal to or less than that of the fixed member 4.

  When the flexible tube having the above structure is joined, the outer peripheral surface of the tube main body 1 is covered with the covering member 2 as shown in FIG. 3 (a), and then the covering member 2 as shown in FIG. 3 (b). The intermediate member 5 is disposed on the distal end side of the straight pipe portion 1c of the tube main body 1 that is not covered with. Next, as shown in FIG. 3 (c), the diameter of the distal end portion of the fixing member 4 is reduced by caulking and the flange portion 4 b is fitted into the groove 3 a of the joint member 3, whereby the fixing member 4 with respect to the joint member 3 is fitted. While restricting the movement in the axial direction, a sealing material 6 made of a thermosetting adhesive (for example, an epoxy adhesive) is applied to the outer peripheral surface of the joint member 3 located inside the fixing member 4. Then, as shown in FIG. 3 (d), an assembly composed of the tube main body 1, the covering member 2 and the intermediate member 5 is inserted between the fixing member 4 and the joint member 3, and the inner peripheral surface of the fixing member 4 and the tube main body. After the intermediate member 5 is arranged between the straight pipe portion 1c of the first straight pipe portion 1c, the fixing member 4 is reduced in diameter by caulking. As a result, the intermediate member 5 is pressed against the distal end side of the straight pipe portion 1 c of the tube body 1 while reducing the diameter together with the fixing member 4, and the inner peripheral surface of the straight pipe portion 1 c is placed on the outer peripheral surface of the joint member 3. Crimp through.

  At that time, as shown in FIG. 2, the fixing member 4 is pressed at a plurality of locations in the circumferential direction by caulking to reduce the diameter, so that the radial pressure between the pressing locations is smaller than each pressing location. 4 is applied to the joint member 3 side through the intermediate member 5 made of a softer metal than the joint member 3, so that the pressure difference is absorbed by the deformation of the intermediate member 5, and the straight pipe portion 1c and the joint member 3 are absorbed. A uniform surface pressure is applied to the circumferential direction. That is, the intermediate member 5 formed separately from the fixing member 4 causes a material to flow between the pressing locations from the respective pressing locations of the caulking according to the pressure difference at the time of deformation. On the inner peripheral surface side, the difference in radial stress is reduced by the flow of the material, and the pressure applied from the intermediate member 5 to the joint member 3 side becomes uniform in the circumferential direction of the intermediate member 5. In this case, since the intermediate member 5 has insufficient strength when the Brinell hardness is smaller than 20 HBW and is difficult to deform when it is larger than 50 HBW, the hardness of the intermediate member 5 is preferably 20 HBW or more and 50 HBW or less. Moreover, the straight pipe part 1 c and the joint member 3 are bonded by the sealing material 6 by curing the sealing material 6 by heating.

  Thus, according to the present embodiment, a cylindrical shape made of a metal softer than the joint member 3 between the outer peripheral surface of the straight pipe portion 1 c not covered with the covering member 2 and the inner peripheral surface of the fixing member 4. Since the tube body 1 is crimped to the joint member 3 by caulking of the fixing member 4, the circumferential pressure difference generated in the fixing member 4 due to caulking is absorbed by deformation of the intermediate member 5. The surface pressure applied to the straight pipe portion 1c and the joint member 3 can be made uniform in the circumferential direction. Thereby, the sealing performance between the straight pipe part 1c and the coupling member 3 can be improved, and the durability against high-pressure fluid can be improved. In this case, the reinforcing layer 2a is not interposed between the inner peripheral surface of the fixing member 4 and the outer peripheral surface of the intermediate member 5, and the intermediate member 5 is brought into direct contact with the fixing member 4 and the straight pipe portion 1c. Therefore, the pressure of the fixing member 4 is directly applied to the intermediate member 5 and the straight pipe portion 1c, and the intermediate member 5 can be always deformed in a stable pressurized state.

  The outer peripheral surface of the joint member 3 to which the straight pipe portion 1c of the tube main body 1 is crimped has an outer diameter substantially equal to the inner diameter of the straight pipe portion 1c of the tube main body 1 and the outer diameter is uniform in the axial direction. Therefore, the entire or part of the straight pipe portion 1c is not reduced in diameter by caulking, and it is possible to reliably prevent the vertical pipe 1c from being caused by the reduced diameter.

  Further, since the intermediate member 5 is formed of a member having a Brinell hardness of 20 HBW or more and 50 HBW or less, the intermediate member 5 can be easily deformed when crimped, and sufficient strength can be obtained even after crimping. This is extremely advantageous.

  Moreover, since the sealing material 6 is interposed between the outer peripheral surface of the joint member 3 and the inner peripheral surface of the straight pipe portion 1c, the sealing performance between the joint member 3 and the straight pipe portion 1c can be further improved. . In this case, since the thermosetting adhesive is used as the sealing material 6, the adhesiveness between the joint member 3 and the straight pipe portion 1 c can be improved, and the pressure resistance of the sealing material 6 is improved by the hardening of the sealing material 6. Can be made.

  In the above-described embodiment, the outer peripheral surface of the joint member 3 to which the straight pipe portion 1c is crimped is formed so that the outer diameter is uniform in the axial direction. However, as shown in FIGS. You may make it provide the groove | channel 3b located in the range of the intermediate member 5 in the outer peripheral surface of the member 3. FIG. In this case, the groove 3b is formed so that the axial width L1 is equal to or less than 1/3 of the axial length L2 of the intermediate member 5. As shown in FIG. As shown in FIG. 4, the joint member 3 is provided at a plurality of positions in the axial direction. Thereby, compared with the case where it does not have the groove | channel 3b, the surface pressure added to the part which the groove | channel 3b does not exist becomes high, and can improve a sealing performance more. In this case, by forming the groove 3b to have a width L1 which is 1/3 or less of the axial length L2 of the intermediate member 5, a portion of the straight pipe portion 1c is not reduced in diameter into the groove 3b. It is possible to prevent the vertical pipe 1c from occurring in the straight pipe portion 1c.

  FIG. 6 is a side sectional view of an essential part of a flexible tube showing a second embodiment of the present invention, and the same reference numerals are given to the same components as those in the embodiment.

  The fixing member 7 of this embodiment has the some convex part 7a and the flange part 7b similarly to the said embodiment.

  The intermediate member 8 of the present embodiment is made of the same material as that of the previous embodiment, and an extending portion 8a extending in the axial direction is provided on one end side in the axial direction. The extending portion 8a is formed in a tapered shape having an inner diameter that is the same as that of the other portion, an outer diameter that is smaller than that of the other portion, and gradually decreasing toward the distal end side.

  In the present embodiment, the extending portion 8 a of the intermediate member 8 is inserted between the straight tube portion 1 c of the tube body 1 and the inner rubber layer 2 b of the covering member 2. Thereby, even if a gap S is generated inside the fixing member 7 other than the tip of the covering member 2 and the extending portion 8a of the intermediate member 8, the extending portion is extended to the straight pipe portion 1c at the position of the gap S. Since the 8a is fitted, the pressure-proof reinforcement of the straight pipe portion 1c in the gap portion can be reliably performed by the extending portion 8a.

The partial cross section side view of the flexible tube which shows the 1st Embodiment of this invention AA arrow direction sectional view of FIG. Side sectional view of the main part showing part of the flexible tube joining process Side surface sectional drawing of the principal part of the flexible tube which shows the modification of 1st Embodiment. Side surface sectional drawing of the principal part of the flexible tube which shows the modification of 1st Embodiment. Side surface sectional drawing of the principal part of the flexible tube which shows the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Tube main body, 1c ... Straight pipe part, 2 ... Cover member, 3 ... Joint member, 3b ... Groove, 4 ... Fixing member, 5 ... Intermediate member, 6 ... Sealing material, 7 ... Fixing member, 8 ... Intermediate member, 8a ... Extension part.

Claims (7)

Connected to the tube body, a tube body made of a metal tube formed in a bellows shape excluding the end portion, a straight tube portion formed at the end portion of the tube body, a covering member covering the outer peripheral surface side of the tube body, and A tubular joint member and a cylindrical fixing member that fixes the tube body to the outer peripheral surface side of the joint member, and the diameter of the fixing member is reduced by caulking so that the straight pipe portion of the tube main body is connected to the outer peripheral surface of the joint member. In the flexible tube joint member connection structure designed to be crimped,
A cylindrical intermediate member made of a softer metal than the joint member is provided between the outer peripheral surface of the straight pipe portion not covered with the covering member and the inner peripheral surface of the fixing member. Flexible tube joint member connection structure. The outer peripheral surface of the joint member to which the straight pipe portion of the tube main body is crimped has an outer diameter substantially equal to the inner diameter of the straight pipe portion of the tube main body, and the outer diameter is formed to be uniform in the axial direction. The flexible tube joint member connection structure according to claim 1, wherein: The groove | channel whose axial direction width | variety of the joint member is 1/3 or less of the length of an intermediate member was provided in the outer peripheral surface of the joint member which the straight pipe part of the said tube main body crimps | bonds. Flexible tube joint member connection structure. The joint member connecting structure for a flexible tube according to claim 1, 2 or 3, wherein the intermediate member is formed of a member having a Brinell hardness of 20 HBW to 50 HBW. The flexible tube joint member connection structure according to claim 1, wherein a sealing material is interposed between an outer peripheral surface of the joint member and an inner peripheral surface of the straight pipe portion. 6. The flexible tube joint member connection structure according to claim 5, wherein a thermosetting adhesive is used as the sealing material. The extension part inserted between the straight pipe | tube part of a tube main body and a coating | coated member is provided in the axial direction one end side of the said intermediate member. The 1, 2, 3, 4, 5 or 6 characterized by the above-mentioned. Flexible tube joint member connection structure.

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