Resin tube connecting device

Abstract

To provide a resin tube connection device which can prevent breakage of a resin tube.SOLUTION: A resin tube connection device includes a resin tube, a resin extension part, and a metal sleeve. The resin extension part has a seal surface contactable with a contact surface. The resin extension part has a second flow channel which communicates with a first flow channel of the resin tube and is opened in the seal surface. The seal surface projects from the end face of the metal sleeve in an axial direction. A maximum length of a contact region of the resin extension part and the metal sleeve in an axial direction in an outside surface is larger than thickness of the resin layer in a radial direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a resin tube connection device.

Background Art

[0002] For example, in a liquid chromatograph, a resin tube may be used when analyzing a sample that is likely to adsorb to metal or when using a mobile phase with metal corrosiveness. The resin tube has a structure in which, for example, the inner surface of a metal tube is coated with a resin layer. When connecting the resin tube to, for example, a separation column, it is necessary to ensure the sealing performance of the flow paths of the resin tube and the separation column. For this purpose, a structure for sealing at the end face of the resin tube has been proposed. For example, Patent Document 1 describes a plug unit for connecting plug capillaries for high-performance liquid chromatography.

[0003] The plug unit has a plug capillary, a pressing body, and a sealing member. The plug capillary has an outer coating portion made of a hard material and an inner coating portion made of an elastic material. The inner coating portion has an end region that extends outward in the radial direction. The pressing body and the sealing member are provided so as to cover the outer peripheral surface of the plug capillary. A bush unit is arranged in the separation column. The bush unit is provided with a housing recess. The plug unit is screwed into the housing recess of the bush unit.

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the plug unit of Patent Document 1, when the contact surface of the pressing body is pressed against the housing recess of the bush unit, the end region undergoes plastic deformation. Thereby, the flow path in the plug capillary is sealed.

[0005] However, when replacing components such as separation columns, it is necessary to remove the plug capillary from the component by detaching the plug unit from the bushing unit, and then screw the plug unit back into the bushing unit to attach the plug capillary to the replacement component. Repeated removal and attachment of the plug capillary can cause damage to the ends of the plug capillary.

[0006] The object of the present invention is to provide a resin tube connecting device that can prevent damage to the resin tube. [Means for solving the problem]

[0007] A resin tube connecting device according to one aspect of the present invention is a resin tube connecting device that can be connected to a member to be connected having a contact surface having a flow path hole, and comprises a resin tube having a metal tube and a resin layer formed on the inner circumferential surface of the metal tube and having a first flow path surrounded by the resin layer, a resin expansion portion formed integrally with the resin tube from the same material as the resin tube and provided to protrude axially from the end of the resin layer and to protrude outward from the metal tube in the radial direction of the resin tube, and a metal sleeve formed to cover the outer circumferential surface of the metal tube and the outer surface of the resin expansion portion, wherein the resin expansion portion has a sealing surface that can contact the contact surface and has a second flow path that communicates with the first flow path of the resin tube and opens at the sealing surface, the sealing surface protrudes axially beyond the end surface of the metal sleeve, and the maximum length of the contact area between the resin expansion portion and the metal sleeve in the axial direction on the outer surface is greater than the thickness of the resin layer in the radial direction.

[0008] A resin tube connecting device according to another aspect of the present invention is a resin tube connecting device that can be connected to a member to be connected having a contact surface having a flow path hole, and comprises a metal tube having a resin layer formed on the inner circumferential surface of the metal tube and projecting axially from the end face of the metal tube, and a flow path surrounded by the resin layer, a resin sealing material joined to the resin layer so as to cover the outer circumferential surface of the portion of the resin layer projecting from the metal tube, and a metal sleeve formed so as to cover the outer circumferential surface of the metal tube and the outer surface of the resin sealing material, wherein the resin sealing material has a sealing surface that can contact the contact surface and has an opening that communicates with the flow path of the resin tube, the sealing surface protrudes axially beyond the end face of the metal sleeve, and the maximum length of the contact area between the resin sealing material and the metal sleeve in the axial direction on the outer surface is greater than the thickness of the resin layer in the radial direction. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a resin tube connecting device that can prevent damage to the resin tube. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of a resin tube connection structure using a resin tube connection device according to the first embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view showing the configuration of a resin tube connecting device according to the first embodiment. [Figure 3] Figure 3 is a schematic cross-sectional view showing the configuration of a resin tube connecting device according to the second embodiment. [Figure 4] Figure 4 is a cross-sectional view of the resin tube connecting device shown in Figure 3, along line AA. [Figure 5] Figure 5 is a cross-sectional view showing another example of the configuration of the recess in the metal sleeve and the fitting portion of the resin expansion. [Figure 6] Figure 6 is a cross-sectional view showing yet another example of the configuration of the recess in the metal sleeve and the fitting portion of the resin expansion. [Figure 7]Figure 7 is a schematic cross-sectional view showing the configuration of a resin tube connecting device according to the third embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, a resin tube connecting device according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] (1) First embodiment Figure 1 is a schematic cross-sectional view showing an example of a resin tube connection structure using a resin tube connection device according to the first embodiment. As shown in Figure 1, the resin tube connection structure 100 comprises a resin tube connection device 1, a bushing 200, and a male nut 300. The bushing 200 is an example of a member to be connected.

[0013] The resin tube connecting device 1 includes a resin tube 10, a resin expansion part 20, and a metal sleeve 30. The resin tube 10 is composed of a metal pipe 11 and a resin layer 12. The resin tube 10 is provided with a first flow path p1 surrounded by the resin layer 12. Hereinafter, one direction in the axial direction of the resin tube 10 will be referred to as the front, and the opposite direction will be referred to as the rear.

[0014] The resin expansion portion 20 is formed integrally with the resin tube 10. The resin expansion portion 20 is provided with a second flow path p2 that communicates with the first flow path p1. The resin expansion portion 20 has a sealing surface 21 perpendicular to the axial direction. The second flow path p2 has an opening 24 in the sealing surface 21. The metal sleeve 30 is formed to cover the metal tube 11 and the resin expansion portion 20.

[0015] The bushing 200 has a receiving recess 210 and a flow path hole 220. The receiving recess 210 includes a large diameter portion 211, a tapered portion 212, and a small diameter portion 213 in that order. An internal thread portion 215 is formed on the inner circumferential surface of the large diameter portion 211. The tapered portion 212 has an inner diameter that gradually decreases toward the front from the front end of the large diameter portion 211. The small diameter portion 213 extends toward the front from the front end of the tapered portion 212. A contact surface 214 is formed at the front end of the small diameter portion 213. The bushing 200 has a flow path hole 220 that penetrates the bushing 200 toward the front from the contact surface 214. In this embodiment, the cross-sectional area of ​​the flow path hole 220 is smaller than the area of ​​the opening 24 of the resin expansion portion 20 on the sealing surface 21 (opening area).

[0016] The male nut 300 has a tightening portion 301 and a protruding portion 302. The male nut 300 has a mounting hole 303 and a through hole 304. The tightening portion 301 is the part to which force is applied when tightening the male nut 300. The tightening portion 301 is also formed so that it can be held by a tightening tool such as a wrench, and has, for example, a polygonal cross-sectional shape. A male threaded portion 315 corresponding to the female threaded portion 215 of the large diameter portion 211 of the bushing 200 is formed on the outer circumferential surface of the protruding portion 302. The mounting hole 303 extends from the front end of the protruding portion 302 toward the rear. A bottom surface 305 is formed at the rear end of the mounting hole 303. The through hole 304 penetrates the male nut 300 toward the rear from the bottom surface 305.

[0017] The resin tube connector 1 is housed in the mounting hole 303 of the male nut 300. The resin tube 10 is inserted through the through hole 304 of the male nut 300. In this state, the protruding portion 302 of the male nut 300 is fitted into the housing recess 210 of the bushing 200, and torque is applied to the tightening portion 301 of the male nut 300 by a tightening tool. As a result, the female threaded portion 215 of the bushing 200 and the male threaded portion 315 of the male nut 300 are screwed together, and the male nut 300 is screwed forward.

[0018] At this time, the rear end surface of the resin tube connecting device 1 is in contact with the bottom surface 305 of the male nut 300. Thereby, the resin tube connecting device 1 moves forward, and the sealing surface 21 of the resin expansion part 20 is pressed against the contact surface 214 of the bushing 200. In this state, when the resin expansion part 20 undergoes plastic deformation, the space between the flow path hole 220 and the second flow path p2 is sealed. As a result, it is possible to prevent the fluid flowing into the flow path hole 220 of the bushing 200 from leaking into the accommodation recess 210.

[0019] FIG. 2 is a schematic cross-sectional view showing the configuration of the resin tube connecting device according to the first embodiment. The metal tube 11 is formed of, for example, stainless steel. The metal tube 11 may be formed of other metals such as titanium, iron, copper, or an alloy. At the front end portion of the metal tube 11, an end surface 11a perpendicular to the axial direction is formed. The resin layer 12 has a thickness t1 in the radial direction. The resin layer 12 is formed of, for example, PEEK (polyether ether ketone). The resin layer 12 may be formed of other resins such as a fluororesin. Further, in the resin tube 10, a first flow path p1 surrounded by the resin layer 12 is formed. In the present embodiment, the metal tube 11, the resin layer 12, and the first flow path p1 each have a circular cross-section.

[0020] The resin expansion part 20 protrudes forward from the front end portion of the resin layer 12 and protrudes outward from the metal tube 11 in the radial direction of the resin tube 10. The resin expansion part 20 has a thickness t2 that is larger than the thickness t1 of the resin layer 12 in the radial direction. Further, the resin expansion part 20 is formed of the same material as the resin layer 12 and by integral molding with the resin layer 12. For example, the resin layer 12 and the resin expansion part 20 may be formed by thermoforming, or may be formed by thermoforming and compression molding at room temperature.

[0021] In this embodiment, the resin expansion part 20 is formed in a cylindrical shape having a front end face, a rear end face 22, and an outer peripheral face. Note that the shape of the resin expansion part 20 is not limited to a cylindrical shape, and may be other shapes such as a prismatic shape or a D-cut shape. The front end face of the resin expansion part 20 is the sealing face 21, and the outer peripheral face is the outer face 23. In this embodiment, the second flow path p2 and the opening 24 each have a circular cross section. Also, in this embodiment, the second flow path p2 has the same inner diameter as the first flow path p1. In this embodiment, the cross-sectional area of the opening 24 gradually increases from the cross-sectional area of the second flow path p2. The inner diameter of the opening 24 on the sealing face 21 is larger than the inner diameter of the first flow path p1. Thereby, the opening area of the opening 24 is larger than the cross-sectional area of the first flow path p1. The outer face 23 extends axially from the outer edge of the sealing face 21 to the outer edge of the rear end face 22. The rear end face 22 is located at the end face 11a of the metal tube 11.

[0022] The metal sleeve 30 is formed so as to cover the outer peripheral face of the metal tube 11 and the outer face 23 of the resin expansion part 20. The metal sleeve 30 is formed of, for example, stainless steel. The metal sleeve 30 may be formed of other metals such as titanium, iron, copper, or an alloy. An end face 30a is formed at the front end part of the metal sleeve 30.

[0023] The sealing face 21 of the resin expansion part 20 protrudes forward in the axial direction from the end face 30a of the metal sleeve 30. Thereby, the end face 30a of the metal sleeve 30 is located between the sealing face 21 of the resin expansion part 20 and the end face 11a of the metal tube 11 in the axial direction.

[0024] The region where the outer face 23 of the resin expansion part 20 and the metal sleeve 30 contact is called the contact region 23c. Also, the maximum length L1 of the contact region 23c in the axial direction is larger than the thickness t1 of the resin layer 12. In this embodiment, since the resin expansion part 20 is formed in a cylindrical shape, the maximum length L1 of the contact region 23c corresponds to the distance between the end face 11a of the metal tube 11 and the end face 30a of the metal sleeve 30.

[0025] In the resin tube connecting device 1 according to the first embodiment, the maximum length L1 of the contact area 23c between the outer surface 23 of the resin expansion portion 20 and the metal sleeve 30 is greater than the thickness t1 of the resin layer 12. In this case, since the axial length of the resin expansion portion 20 is large, the resin expansion portion 20 is less likely to be damaged even if a torsional torque is applied to it. Also, a large frictional force acts between the contact area 23c of the outer surface 23 of the resin expansion portion 20 and the metal sleeve 30, so the resin expansion portion 20 is firmly fixed to the metal sleeve 30. As a result, twisting of the resin tube 10 is suppressed. Furthermore, since the outer surface 23 of the resin expansion portion 20 is held by the metal sleeve 30, even if an axial compressive force is applied to the resin expansion portion 20, the sealing surface 21 is prevented from expanding radially outward. In addition, since the resin expansion portion 20 is formed in a columnar shape such as a cylindrical shape, the durability of the resin expansion portion 20 is improved. As a result, damage to the resin tube 10 and the resin expansion portion 20 is prevented when the resin tube connection device 1 is attached to the bushing 200.

[0026] Furthermore, the opening area of ​​the opening 24 of the resin expansion part 20 is larger than the cross-sectional area of ​​the flow path hole 220 of the bushing 200. Therefore, when the sealing surface 21 of the resin expansion part 20 is pressed against the contact surface 214, the peripheral edge of the opening 24 of the resin expansion part 20 does not enter the flow path hole 220. This prevents the peripheral edge of the opening 24 of the resin expansion part 20 from plastically deforming inward, thus preventing the opening 24 of the resin expansion part 20 from becoming blocked. In addition, since the resin on the sealing surface 21 of the resin expansion part 20 does not enter the flow path hole 220 of the bushing 200, the sealing surface 21 of the resin expansion part 20 is not pulled when the resin tube connector 1 is removed. This prevents damage to the sealing surface 21 of the resin expansion part 20.

[0027] In this embodiment, the outer surface 23 of the resin expansion portion 20 is formed to extend in the axial direction, but the outer surface 23 may be formed to extend in a curved shape from the outer edge of the sealing surface 21 to the end surface 11a of the metal pipe 11 without a rear end surface 22 being formed. Also, in this embodiment, the metal pipe 11, the resin layer 12, and the first flow path p1 each have a circular cross-section, but the metal pipe 11, the resin layer 12, and the first flow path p1 may have other cross-sections such as polygonal or elliptical shapes.

[0028] Furthermore, in this embodiment, the second flow path p2 and the opening 24 each have a circular cross-section, but the second flow path p2 and the opening 24 may have cross-sections of other shapes, such as polygonal or elliptical. In addition, in this embodiment, the second flow path p2 has the same inner diameter as the first flow path p1, but the second flow path p2 may have a larger or smaller inner diameter than the first flow path p1.

[0029] (2) Second embodiment Figure 3 is a schematic cross-sectional view showing a resin tube connecting device according to the second embodiment. Figure 4 is a cross-sectional view of the resin tube connecting device of Figure 3 along line AA. The resin tube connecting device 1 of Figure 3 differs from the resin tube connecting device 1 of Figure 2 in the following respects.

[0030] The end face 30a of the metal sleeve 30 is formed flush with the end face 11a of the metal tube 11. One or more recesses 32 are provided on the end face 30a of the metal sleeve 30. In this embodiment, as shown in Figure 4, the recesses 32 have an annular shape that surrounds the resin tube 10.

[0031] As shown in Figure 3, the resin expansion portion 20 includes an end face covering portion 20a and a fitting portion 20b. The end face covering portion 20a extends radially from the resin layer 12 so as to protrude outward from the metal pipe 11 and is formed on the end face 11a of the metal pipe 11 and the end face 30a of the metal sleeve 30. As a result, the end face covering portion 20a has a thickness t2 that is greater than the thickness t1 of the resin layer 12 in the radial direction. The end face covering portion 20a has a sealing surface 21.

[0032] The fitting portion 20b is formed to extend rearward from the outer circumference of the end face covering portion 20a. The fitting portion 20b is formed integrally with the end face covering portion 20a. In this embodiment, as shown in Figure 4, the fitting portion 20b has an annular cross-section corresponding to the recess 32. As a result, the fitting portion 20b has a cylindrical shape. As shown in Figure 3, the outer surface 23 of the end face covering portion 20a extends in the axial direction from the outer edge of the sealing surface 21 to the rear end surface 22b of the fitting portion 20b. The fitting portion 20b is fitted into the recess 32. Since the fitting portion 20b is fitted into the recess 32, the maximum length L1 of the contact area 23c of the outer surface 23 of the resin expansion portion 20 corresponds to the distance from the end face 30a of the metal sleeve 30 to the bottom surface of the recess 32 (depth of the recess 32) in the axial direction. The resin expansion portion 20 in this embodiment is formed, for example, by ultrasonic processing.

[0033] In the resin tube connecting device 1 according to the second embodiment, the maximum length L1 of the contact area 23c of the resin expansion portion 20 is longer than the thickness t1 of the resin layer 12. In this case, since the axial length of the resin expansion portion 20 is large, the resin expansion portion 20 is less likely to be damaged even if a torsional torque is applied to it. Also, since the fitting portion 20b of the resin expansion portion 20 is fitted into the recess 32 of the metal sleeve 30, the outer surface 23 of the resin expansion portion 20 is held by the metal sleeve 30. In this case, a large frictional force acts between the contact area 23c of the outer surface 23 of the fitting portion 20b and the metal sleeve 30, so the resin expansion portion 20 is firmly fixed to the metal sleeve 30. As a result, twisting of the resin tube 10 is suppressed. In addition, since the outer surface 23 of the resin expansion portion 20 is held by the metal sleeve 30, even if an axial compressive force is applied to the resin expansion portion 20, the sealing surface 21 is prevented from expanding radially outward. As a result, damage to the resin tube 10 and the resin expansion portion 20 is prevented.

[0034] Furthermore, the opening area of ​​the opening 24 of the resin expansion portion 20 is larger than the cross-sectional area of ​​the flow path hole 220 of the bushing 200. As a result, similar to the first embodiment, the opening 24 of the resin expansion portion 20 is prevented from being blocked, and damage to the sealing surface 21 of the resin expansion portion 20 is prevented when the resin tube connecting device 1 is removed.

[0035] The configuration of the recess 32 of the metal sleeve 30 and the fitting portion 20b of the resin expansion portion 20 is not limited to the configuration shown in Figure 4. Figure 5 is a cross-sectional view showing another example of the configuration of the recess 32 of the metal sleeve 30 and the fitting portion 20b of the resin expansion portion 20. Figure 6 is a cross-sectional view showing yet another example of the configuration of the recess 32 of the metal sleeve 30 and the fitting portion 20b of the resin expansion portion 20.

[0036] In the example shown in Figure 5, a plurality of recesses 32 are formed on the end face 30a of the metal sleeve 30. The resin expansion portion 20 has a plurality of fitting portions 20b that can be fitted into the plurality of recesses 32. The plurality of recesses 32 and the plurality of fitting portions 20b may be provided at multiple positions that are axially symmetric with respect to the axis of the resin tube 10, or at any multiple positions that are not axially symmetric. Furthermore, the plurality of recesses 32 and the plurality of fitting portions 20b may be provided at equal intervals or at different intervals. The cross-sectional shape of each recess 32 may be circular, polygonal, elliptical, or other shapes.

[0037] In the example shown in Figure 6, a recess 32 is formed in the end face 30a of the metal sleeve 30. The resin extension 20 has a fitting portion 20b that can be fitted into the recess 32. The cross-sectional shape of the recess 32 may be circular, polygonal, elliptical, or other shapes.

[0038] In the examples of Figures 5 and 6, the same effects as in the example of Figure 4 are obtained, and the rotation of the resin expansion portion 20 relative to the metal sleeve 30 is reliably prevented.

[0039] (3) Third Embodiment Figure 7 is a schematic cross-sectional view showing a resin tube connecting device according to the third embodiment. The resin tube connecting device 1 in Figure 7 differs from the resin tube connecting device 1 in Figure 2 in the following ways.

[0040] The resin tube connecting device 1 includes a resin sealing material 40 instead of a resin expansion portion 20. The resin sealing material 40 is, for example, a packing. The resin sealing material 40 is formed separately from the resin layer 12, for example, by PEEK (polyetheretherketone). The resin sealing material 40 may also be formed from other resins such as fluororesin. In this embodiment, the resin sealing material 40 is formed in a cylindrical shape having a front end surface, a rear end surface, an outer circumferential surface, and an inner circumferential surface. As a result, a through hole h1 extending in the axial direction is formed in the resin sealing material 40. Note that the shape of the resin sealing material 40 is not limited to a cylindrical shape, and may be other shapes such as a rectangular tube shape.

[0041] The front end surface of the resin seal material 40 is the sealing surface 41, and the outer circumferential surface is the outer surface 43. The outer surface 43 is formed to extend axially from the outer edge of the sealing surface 41 to the outer edge of the rear end surface. The inner circumferential surface 44 is formed to extend axially from the inner edge of the sealing surface 41 to the inner edge of the rear end surface. In this case, the resin seal material 40 has a length L2 in the axial direction.

[0042] The resin layer 12 formed on the inner circumferential surface of the metal pipe 11 has a portion that protrudes forward from the end face 11a of the metal pipe 11. Hereinafter, the portion of the resin layer 12 that protrudes from the end face 11a of the metal pipe 11 will be referred to as the resin layer projection 13. The resin layer projection 13 has a length L3 that is shorter than the length L2 of the resin seal material 40. The resin layer projection 13 is inserted into the through hole h1 of the resin seal material 40. As a result, the rear end face of the resin seal material 40 and the end face 11a of the metal pipe 11 come into contact.

[0043] In this case, since the length L2 of the resin seal material 40 is greater than the length L3 of the resin layer projection 13 of the resin tube 10, the sealing surface 41 of the resin seal material 40 protrudes forward in the axial direction beyond the end face of the resin layer projection 13. As a result, an opening 45 communicating with the first flow path p1 of the resin tube 10 is formed in the sealing surface 41. The opening area of ​​the opening 45 corresponds to the cross-sectional area of ​​the through hole h1. In this embodiment, the opening area of ​​the opening 45 is greater than the cross-sectional area of ​​the flow path hole 220 of the bushing 200 in Figure 1.

[0044] The outer surface of the resin layer protrusion 13 and the inner surface of the resin sealant 40 are joined by heat welding. Alternatively, the outer surface of the resin layer protrusion 13 and the inner surface of the resin sealant 40 may be joined by an adhesive or the like.

[0045] The metal sleeve 30 is formed to cover the outer circumferential surface of the metal pipe 11 and the outer surface 43 of the resin sealant 40. An end face 30a is formed at the front end of the metal sleeve 30. The sealing surface 41 of the resin sealant 40 protrudes forward in the axial direction beyond the end face 30a of the metal sleeve 30. The area where the outer surface 43 of the resin sealant 40 and the metal sleeve 30 are in contact is called the contact area 43c. The maximum axial length L1 of the contact area 43c is greater than the thickness t1 of the resin layer 12.

[0046] In the resin tube connecting device 1 according to the third embodiment, the resin layer 12 of the resin tube 10 and the resin sealing material 40 are formed from resin material. As a result, the resin layer 12 of the resin tube 10 and the resin sealing material 40 are firmly fixed together by heat welding. In addition, the maximum length L1 of the contact area 43c is greater than the thickness t1 of the resin layer 12. In this case, since the axial length of the resin sealing material 40 is large, the resin sealing material 40 is less likely to be damaged even if a torsional torque is applied to it.

[0047] Furthermore, a large frictional force acts between the contact area 43c of the outer surface 43 of the resin seal material 40 and the metal sleeve 30, so the resin seal material 40 is firmly fixed to the metal sleeve 30. This suppresses twisting of the resin tube 10. Also, since the outer surface 43 of the resin seal material 40 is held by the metal sleeve 30, even if an axial compressive force is applied to the resin seal material 40, the sealing surface 41 is prevented from expanding radially outward. In addition, since the resin seal material 40 is formed in a cylindrical shape, the durability of the resin seal material 40 is improved. As a result of these factors, damage to the resin tube 10 is prevented.

[0048] Furthermore, the opening area of ​​the opening 45 of the resin seal material 40 is larger than the cross-sectional area of ​​the flow path hole 220 of the bushing 200. As a result, similar to the first embodiment, the opening 45 of the resin seal material 40 is prevented from being blocked, and damage to the sealing surface 41 of the resin seal material 40 is prevented when the resin tube connecting device 1 is removed.

[0049] Furthermore, the resin layer protrusion 13 of the resin layer 12 of the resin tube 10 is inserted into the through hole h1 of the resin seal material 40, and the inner circumferential surface 44 of the resin seal material 40 is joined to the outer circumferential surface of the resin layer protrusion 13 by heat welding. In this case, the resin tube connecting device 1 can be easily manufactured.

[0050] (4) Aspect Those skilled in the art will understand that the above-described exemplary embodiments are specific examples of the following embodiments.

[0051] (Article 1) A resin tube connecting device according to one embodiment is: A resin tube connecting device that can be connected to a member to be connected, having a contact surface with flow channel holes, A resin tube having a metal pipe, a resin layer formed on the inner surface of the metal pipe, and a first flow path surrounded by the resin layer, A resin expansion portion is formed integrally with the resin tube from the same material as the resin tube, and is provided to protrude axially from the end of the resin layer and to protrude outward from the metal tube in the radial direction of the resin tube, The metal tube comprises a metal sleeve formed to cover the outer surface of the metal tube and the outer surface of the resin expansion portion, The resin expansion portion has a sealing surface that can contact the contact surface, and a second flow path that communicates with the first flow path of the resin tube and opens at the sealing surface. The sealing surface protrudes in the axial direction from the end face of the metal sleeve. The maximum length of the contact area between the resin expansion portion and the metal sleeve in the axial direction on the outer surface may be greater than the thickness of the resin layer in the radial direction.

[0052] According to the resin tube connecting device described in paragraph 1, the resin expansion portion, which is integrally formed with the resin layer of the resin tube, is provided to protrude outward from the metal tube. Furthermore, the outer surface of the metal tube and the outer surface of the resin expansion portion are covered by a metal sleeve. When connecting the resin tube to the member to be connected, torque is applied to the metal sleeve, and the sealing surface of the resin expansion portion is pressed against the contact surface of the member to be connected. As a result, the opening of the second flow path of the resin expansion portion and the flow path hole of the member to be connected are in communication, and the space between the contact surface of the member to be connected and the sealing surface of the resin expansion portion is sealed.

[0053] According to the above configuration, the maximum length of the contact area between the resin expansion portion and the metal sleeve in the axial direction is greater than the thickness of the resin layer in the radial direction. In this case, because the axial length of the resin expansion portion is large, it is less likely to be damaged even if a torsional torque is applied to the resin expansion portion. Also, when torque is applied to the metal sleeve, a large frictional force acts between the resin expansion portion and the metal sleeve, so the resin expansion portion is firmly held against the metal sleeve. This suppresses twisting of the resin tube. Furthermore, since the outer surface of the resin expansion portion is held by the metal sleeve, even if an axial compressive force is applied to the resin expansion portion, the sealing surface is prevented from expanding radially outward. As a result, damage to the resin tube is prevented.

[0054] (Section 2) In the resin tube connecting device described in Section 1, the end face of the metal sleeve is located in the axial direction between the sealing surface and the end face of the metal tube, and the outer surface of the resin expansion portion extends in the axial direction to the end face of the metal tube. The maximum length of the contact area between the resin expansion portion and the metal sleeve on the outer surface may correspond to the distance between the end face of the metal sleeve and the end face of the metal tube in the axial direction.

[0055] According to the resin tube connecting device described in paragraph 2, the length of the resin expansion portion that protrudes from the end face of the metal tube in the axial direction can be increased, thereby improving the durability of the resin expansion portion.

[0056] (Article 3) In the resin tube connecting device described in Article 2, The resin expansion portion is formed in a columnar shape having one end face, the other end face, and the outer surface. The one end face of the columnar shape may be the sealing surface, and the other end face of the columnar shape may be in contact with the end face of the metal pipe in the axial direction.

[0057] According to the resin tube connecting device described in paragraph 3, the durability of the resin expansion portion can be further improved because the resin expansion portion has a columnar shape.

[0058] (Article 4) In the resin tube connecting device described in Article 1, The end face of the metal sleeve is formed flush with the end face of the metal tube. The end face of the metal sleeve has a recess, The resin expansion portion is, An end face covering portion formed on the end face of the metal pipe and on the end face of the metal sleeve so as to protrude outward from the metal pipe in the radial direction, It may also include a fitting portion that is integrally formed with the end face covering portion, has the outer surface, and is fitted into the recess.

[0059] According to the resin tube connecting device described in paragraph 4, the fitting portion of the resin expansion part is fitted into the recess of the metal sleeve, so the resin expansion part is securely held by the metal sleeve. As a result, twisting of the resin tube is suppressed when torque is applied to the metal sleeve. As a result, damage to the resin tube is prevented.

[0060] (Article 5) In the resin tube connecting device described in any one of paragraphs 1 to 4, The area of ​​the opening of the second flow path on the sealing surface of the resin expansion portion may be larger than the cross-sectional area of ​​the first flow path of the resin tube.

[0061] According to the resin tube connecting device described in paragraph 5, when the sealing surface of the resin expansion part is pressed against the contact surface of the member to be connected, the second flow path of the resin expansion part is prevented from being blocked.

[0062] (Clause 6) A resin tube connecting device according to another embodiment is a resin tube connecting device that can be connected to a member to be connected, having a contact surface with flow path holes, A resin tube having a metal pipe, a resin layer formed on the inner circumferential surface of the metal pipe and protruding axially from the end face of the metal pipe, and a flow channel surrounded by the resin layer, A resin sealing material is bonded to the resin layer so as to cover the outer surface of the portion of the resin layer that protrudes from the metal pipe, The metal tube comprises a metal sleeve formed to cover the outer surface of the metal tube and the outer surface of the resin sealing material, The resin sealing material has a sealing surface that can contact the contact surface and has an opening that communicates with the flow path of the resin tube. The sealing surface protrudes in the axial direction from the end face of the metal sleeve. The maximum length of the contact area between the resin sealing material and the metal sleeve in the axial direction on the outer surface may be greater than the thickness of the resin layer in the radial direction.

[0063] According to the resin tube connecting device described in paragraph 6, a resin sealing material is bonded to the outer surface of the portion of the resin layer of the resin tube that protrudes from the metal tube. In addition, the outer surface of the metal tube and the outer surface of the resin sealing material are covered by a metal sleeve. When connecting the resin tube to the member to be connected, torque is applied to the metal sleeve, and the sealing surface of the resin sealing material is pressed against the contact surface of the member to be connected. As a result, the space between the contact surface of the member to be connected and the sealing surface of the resin sealing material is sealed, with the opening of the resin sealing material communicating with the flow path hole of the member to be connected.

[0064] According to the above configuration, since the resin layer of the resin tube and the resin seal material are formed of resin, the resin seal material can be firmly bonded to the resin layer of the resin tube. Furthermore, the maximum length of the contact area between the resin seal material and the metal sleeve in the axial direction is greater than the thickness of the resin layer in the radial direction. In this case, because the axial length of the resin seal material is large, the resin seal material is less likely to be damaged even if torsional torque is applied to it. Also, when torque is applied to the metal sleeve, a large frictional force acts between the resin seal material and the metal sleeve, so the outer surface of the resin seal material is firmly held by the metal sleeve. This suppresses twisting of the resin tube. In addition, since the outer surface of the resin expansion part is held by the metal sleeve, even if an axial compressive force is applied to the resin expansion part, the sealing surface is prevented from expanding radially outward. As a result, damage to the resin tube is prevented.

[0065] (Item 7) In the resin tube connecting device described in Item 6, The resin sealing material may be joined to the outer surface of the resin layer by welding.

[0066] According to the resin tube connecting device described in paragraph 7, the resin sealing material is more firmly bonded to the outer surface of the resin layer.

[0067] (Clause 8) In the resin tube connecting device described in paragraph 6 or 7, The area of ​​the opening on the sealing surface of the resin sealing material may be larger than the cross-sectional area of ​​the flow path of the resin tube.

[0068] According to the resin tube connecting device described in paragraph 8, when the sealing surface of the resin expansion portion is pressed against the contact surface of the member to be connected, the opening of the resin sealing material is prevented from closing.

[0069] (Paragraph 9) In the resin tube connecting device described in any one of paragraphs 6 to 8, The resin sealing material has a through hole extending in the axial direction, The portion of the resin layer that protrudes in the axial direction is inserted into the through hole of the resin seal material, and the inner circumferential surface of the resin seal material is joined to the outer circumferential surface of the resin layer. The opening may be formed on the sealing surface of the resin sealing material by the sealing surface protruding in the axial direction from the end face of the resin layer.

[0070] According to the resin tube connecting device described in paragraph 9, the resin tube connecting device can be easily manufactured by inserting the protruding portion of the resin layer of the resin tube into the through hole of the resin seal material and joining the inner circumferential surface of the resin seal material to the outer circumferential surface of the resin layer.

Claims

1. A resin tube connecting device that can be connected to a member to be connected, having a contact surface with flow channel holes, A resin tube having a metal pipe, a resin layer formed on the inner surface of the metal pipe, and a first flow path surrounded by the resin layer, A resin expansion portion is formed integrally with the resin layer using the same material as the resin layer, and is provided to protrude axially from the end of the resin layer and to protrude outward from the metal tube in the radial direction of the resin tube, The metal tube comprises a metal sleeve formed to cover the outer surface of the metal tube and the outer surface of the resin expansion portion, The resin expansion portion has a sealing surface that can contact the contact surface, and a second flow path that communicates with the first flow path of the resin tube and opens at the sealing surface. The sealing surface protrudes in the axial direction from the end face of the metal sleeve. The resin expansion portion is formed in a columnar shape, and the resin tube connecting device.

2. The resin tube connecting device according to claim 1, wherein the maximum length of the contact area between the resin expansion portion and the metal sleeve in the axial direction on the outer surface is made greater than the thickness of the resin layer in the radial direction, thereby suppressing damage to the resin tube or the resin expansion portion when a torsional torque is applied.

3. The end face of the metal sleeve is located in the axial direction between the sealing surface and the end face of the metal tube, and the outer surface of the resin expansion portion extends in the axial direction to the end face of the metal tube. The resin tube connecting device according to claim 1, wherein the maximum length of the contact area between the resin expansion portion and the metal sleeve on the outer surface corresponds to the distance between the end face of the metal sleeve and the end face of the metal tube in the axial direction.

4. The resin expansion portion is formed in a columnar shape having one end face, the other end face, and the outer surface. The resin tube connecting device according to claim 1, wherein one end face of the columnar shape is the sealing surface, and the other end face of the columnar shape is in contact with the end face of the metal tube in the axial direction.

5. A resin tube connecting device that can be connected to a member to be connected, having a contact surface with flow channel holes, A resin tube having a metal pipe, a resin layer formed on the inner surface of the metal pipe, and a first flow path surrounded by the resin layer, A resin expansion portion is formed integrally with the resin layer using the same material as the resin layer, and is provided to protrude axially from the end of the resin layer and to protrude outward from the metal tube in the radial direction of the resin tube, The metal tube comprises a metal sleeve formed to cover the outer surface of the metal tube and the outer surface of the resin expansion portion, The resin expansion portion has a sealing surface that can contact the contact surface, and a second flow path that communicates with the first flow path of the resin tube and opens at the sealing surface. The sealing surface protrudes in the axial direction from the end face of the metal sleeve. The end face of the metal sleeve is formed flush with the end face of the metal tube. The end face of the metal sleeve has recesses at predetermined distances from the inner and outer circumferential surfaces of the metal sleeve, respectively. The resin expansion portion is, An end face covering portion formed on the end face of the metal pipe and on the end face of the metal sleeve so as to protrude outward from the metal pipe in the radial direction, It includes a fitting portion which is integrally formed with the end face covering portion, has the outer surface, and is fitted into the recess, A resin tube connecting device in which the outer surface and inner surface of the fitting portion are in contact with the metal sleeve within the recess.

6. The resin tube connecting device according to claim 1, wherein the area of ​​the opening of the second flow path in the sealing surface of the resin expansion portion is larger than the cross-sectional area of ​​the first flow path of the resin tube.

7. A method for manufacturing a resin tube connecting device according to claim 1, The steps of integrally molding the resin expansion portion and the resin layer by thermoforming, A manufacturing method comprising the step of integrally molding the resin expansion portion and the resin layer by thermoforming and compression molding at room temperature.

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