Joint and method for fixing tube to joint

Abstract

To provide a joint capable of more firmly fixing a tube and a method for fixing the tube to the joint.SOLUTION: According to the present invention, a joint 1 includes a joint body 2 provided with an insertion part 21, a sleeve 3 fitted externally to a tube T, and a fixing member 4 connectable to the joint body 2 by performing relative movement in a first direction D1 along an axis X direction of the tube T. The fixing member 4 includes a pressing part 41 for pressing an outer fitting part TA of the tube T from an outer peripheral side, and a contact part 42 that can be brought into contact with the sleeve 3 in the axis X direction, and the fixing member 4 is configured so as to plastically deform an outer peripheral surface TAs of the outer fitting part TA of the tube T to form a projection part PR on the outer peripheral surface TAs of the outer fitting part TA of the tube T by making the pressing part 41 and the contact part 42 press the outer peripheral surface TAs of the outer fitting part TA of the tube T through the sleeve 3 inward in a radial direction RD and in the first direction D1 in performing relative movement in the first direction D1 for connection to the joint body 2.SELECTED DRAWING: Figure 5C

Description

[Technical field]

[0001] The present invention relates to a fitting and a method for fastening a tube to a fitting. [Background technology]

[0002] Conventionally, a joint as disclosed in Patent Document 1, for example, has been used to connect a tube to another tube or device. The joint in Patent Document 1 includes a joint body having an insertion portion onto which the tube is fitted, a clamp ring fitted onto the tube, and a clamp nut fitted onto the clamp ring and connected to the joint body. When the clamp nut is connected to the joint body with the tube fitted onto the insertion portion of the joint body, the tube is pressed against the insertion portion on the radial inside by the clamp nut via the clamp ring, and the tube is fixed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2011 / 0163530 Summary of the Invention [Problem to be solved by the invention]

[0004] In the joint of Patent Document 1, the pressing force of the clamp nut generates a frictional force between the outer peripheral surface of the tube and the inner peripheral surface of the clamp ring. However, the frictional force generated between the outer peripheral surface of the tube and the inner peripheral surface of the clamp ring cannot be expected to have a significant effect in preventing the tube from coming off in a direction perpendicular to the frictional surface, and there is a risk that the tube will come off when a larger force is applied to the tube.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a joint that can more firmly fix a tube, and a method of fixing a tube to a joint. [Means for solving the problem]

[0006] A joint of the present invention is a joint to which a substantially cylindrical tube is fixed, the joint comprising: a joint body having an insertion portion onto which the tube is fitted; a substantially cylindrical sleeve fitted onto an outer periphery of the tube so as to be movable along the axial direction of the tube; and a fixing member provided on the outer periphery of the tube so as to be movable along the axial direction of the tube, and connectable to the joint body by moving relatively in a first direction which is a direction along the axial direction of the tube toward the joint body, the fixing member having a pressing portion that presses the outer fitting portion of the tube fitted onto the insertion portion from the outer periphery toward the insertion portion on the radially inner side, and an abutting portion that can abut against the sleeve in the axial direction so as to suppress relative movement of the sleeve relative to the fixing member in a second direction opposite to the first direction, and the sleeve is configured to be in contact with the fixing member when the fixing member is connected to the joint body, the pressing portion pressing the outer fitting portion of the tube fitted onto the insertion portion from the outer periphery toward the insertion portion on the radially inner side, the sleeve abuts against the abutment portion in the axial direction and moves relatively in the first direction together with the fixing member, and is disposed between the outer fitting portion of the tube and the pressing portion of the fixing member when the fixing member is connected to the fitting body, and the fixing member is configured such that, when the fixing member moves relatively in the first direction to connect to the fitting body, the pressing portion and the abutment portion press an outer peripheral surface of the outer fitting portion of the tube in the radially inward and in the first direction via the sleeve, thereby plastically deforming the outer peripheral surface of the outer fitting portion of the tube to form a protrusion on the outer peripheral surface of the outer fitting portion of the tube, and the protrusion protrudes radially outward from the outer peripheral surface of the outer fitting portion of the tube and is configured to be engageable with the sleeve in the axial direction so as to suppress relative movement of the tube in the second direction with respect to the sleeve.

[0007] A method of the present invention is a method of fixing a substantially cylindrical tube to a fitting, the fitting comprising: a fitting body having an insertion portion onto which the tube is fitted; a substantially cylindrical sleeve fitted onto an outer periphery of the tube so as to be movable along the axial direction of the tube; and a fixing member provided on the outer periphery of the tube so as to be movable along the axial direction of the tube, the fixing member having a pressing portion that presses the outer fitting portion of the tube fitted onto the insertion portion from the outer periphery to the insertion portion on the radially inner side, and an abutting portion that can abut against the sleeve in the axial direction so as to suppress relative movement of the sleeve in a second direction opposite to the first direction with respect to the fixing member, and the tube is disposed between the fitting portion and the pressing portion of the fixing member, the method including the steps of: providing the fixing member on an outer circumferential side of the tube; fitting the sleeve onto the tube on the first direction side of the fixing member; fitting the tube onto the insertion portion of the coupling body; and moving the fixing member relatively in a first direction along the axial direction to connect the fixing member to the coupling body, thereby fixing the tube to the coupling body, and the method further including the steps of: moving the fixing member in the first direction to connect the fixing member to the coupling body. the step of pressing an outer circumferential surface of the outer fitting portion of the tube in the radially inward and first direction via the sleeve with the pressing portion and the abutment portion to plastically deform the outer circumferential surface of the outer fitting portion of the tube, thereby forming a protrusion on the outer circumferential surface of the outer fitting portion of the tube, wherein the protrusion protrudes radially outward from the outer circumferential surface of the outer fitting portion of the tube and is configured to be engageable with the sleeve in the axial direction so as to suppress relative movement of the tube with respect to the sleeve in the second direction. Effect of the Invention

[0008] According to the present invention, it is possible to provide a joint capable of more firmly fixing a tube and a method for fixing a tube to a joint. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing the overall structure of a joint according to an embodiment of the present invention before a tube is fixed thereto. [Diagram 2] FIG. 2 is a partial cross-sectional view of an insertion portion of a joint body used in a joint according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a partially enlarged view of FIG. [Figure 4] FIG. 4 is a partial cross-sectional view of a fixing member used in a joint according to an embodiment of the present invention. [Figure 5A] 2 is a cross-sectional view of the joint showing a state in which a tube has been fitted onto an insertion portion of the joint body from the state shown in FIG. 1. [Figure 5B] 5B is a cross-sectional view of the joint showing a state in which the fixing member has been moved in a first direction from the state shown in FIG. 5A. [Figure 5C] 5C is a cross-sectional view of the joint illustrating a state in which the fixing member has been moved in a first direction from the state illustrated in FIG. 5B and is connected to the joint body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a joint according to an embodiment of the present invention will be described with reference to the accompanying drawings. However, the embodiment described below is merely an example, and the joint of the present invention is not limited to the embodiment described below.

[0011] The joint 1 of this embodiment is a member to which a substantially cylindrical tube T is fixed, as shown in FIG. 1 and FIG. 5C. The joint 1, together with the tube T, constitutes a joint structure including the joint 1 and the tube T. The joint 1 is used, for example, to connect the fixed tube T to a connection target such as another tube or device. The tube T has an inner cavity extending along the axial direction X, which is the direction in which the central axis X of the tube T extends, and is configured so that a fluid such as a gas or liquid flows through the inner cavity. The tube T may be formed of a flexible material in order to be routed along various paths. The other tube to which the tube T is connected via the joint 1 may be the same type of tube as the tube T as shown in FIG. 1, or may be a different type of tube from the tube T. The device to which the tube T is connected via the joint 1 is not particularly limited as long as it is a device that requires the tube T to be connected in order to flow a fluid, and examples thereof include an inkjet printer and an analysis device for analyzing biological samples.

[0012] 1, the joint 1 includes a joint body 2 to which a tube T is connected, a substantially cylindrical sleeve 3 fitted onto the outside of the tube T, and a fixing member 4 that fixes the tube T to the joint body 2. As described in detail below, from the state shown in FIG. 1, the tube T is connected to the joint body 2 (see FIG. 5A), and the fixing member 4 is relatively moved in a first direction D1, which is a direction toward the joint body 2 along the axial X direction of the tube T (see FIG. 5B), and then connected to the joint body 2, thereby fixing the tube T (see FIG. 5C).

[0013] The joint body 2 is a member to which the tube T is connected, and which connects the connected tube T to a connection target such as another tube or device. In order to connect the tube T, the joint body 2 is provided with an insertion section 21 on which the tube T is fitted, as shown in FIG. 1. In this embodiment, the joint body 2 is formed in a cylindrical shape having an inner cavity that communicates with the inner cavity of the tube T when the tube T is connected and is approximately coaxial with the central axis X of the tube T, and is configured so that a fluid flows through the inner cavity. In this embodiment, the joint body 2 is provided with an insertion section 21 on each of both ends, and is configured to connect the tube T to another tube T. However, the joint body 2 only needs to be able to connect at least one tube T, and the number of insertion sections 21 provided may be one or three or more, and the structure other than the insertion section 21 is not particularly limited to the structure in this embodiment.

[0014] The insertion portion 21 may be formed so that the tube T can be fitted thereon, and the shape of the insertion portion 21 is not particularly limited. In this embodiment, the insertion portion 21 is formed in a substantially cylindrical shape extending along the axial direction X so that the tube T can be fitted thereon, as shown in FIG. 2. The insertion portion 21 has an outer diameter larger than the inner diameter of the tube T before being fitted thereon, and has at least one protrusion 21a protruding outward in the radial direction RD, so that the fitted tube T is prevented from coming off. The protrusion 21a is configured to engage with the inner circumferential surface of the tube T in the axial direction X when the tube T is fitted on the insertion portion 21 and the fixing member 4 is connected to the joint main body 2. The protrusion 21a may be formed in a substantially annular shape like the large diameter portion 21a described later, or may have a shape that is partially interrupted along the circumferential direction (direction around the axis X) of the outer periphery.

[0015] In this embodiment, as shown in FIG. 2, the insertion portion 21 includes at least one large diameter portion 21a constituting at least one protrusion 21a, and at least one small diameter portion 21b provided continuously with the large diameter portion 21a on the first direction D1 side of the large diameter portion 21a. The large diameter portion 21a is formed in a substantially annular shape extending along the circumferential direction of the outer periphery of the insertion portion 21, and is formed so that the maximum outer diameter of the large diameter portion 21a is larger than the maximum outer diameter of the small diameter portion 21b. In this embodiment, the large diameter portion 21a has an inclined portion S that gradually expands in diameter on the first direction D1 side, and a cylindrical portion C that is provided continuously with the inclined portion S on the first direction D1 side of the inclined portion S and extends with approximately the same diameter along the axis X direction. Since the large diameter portion 21a has the cylindrical portion C, it is possible to disperse the pressing force when the tube T and the insertion portion 21 are pressed by the pressing portion 41 of the fixing member 4 described later, and it is possible to suppress damage to the tube T and the insertion portion 21. The small diameter portion 21b is formed in a substantially annular shape along the circumferential direction of the outer periphery of the insertion portion 21, and is provided continuous with the cylindrical portion C on the first direction D1 side of the cylindrical portion C of the large diameter portion 21a. A step portion 21c configured as a wall surface substantially perpendicular to the axial direction X is formed between the large diameter portion 21a and the small diameter portion 21b.

[0016] In this embodiment, the insertion portion 21 has two sets of a large diameter portion 21a and a small diameter portion 21b along the axis X direction, as shown in Figures 2 and 3. The two large diameter portions 21a, 21a are formed so that the maximum outer diameter of the large diameter portion 21a on the first direction D1 side (the large diameter portion 21a on the left side in the figure) is larger than the maximum outer diameter of the large diameter portion 21a on the second direction D2 side opposite to the first direction D1 (the large diameter portion 21a on the right side in the figure). Furthermore, the two large diameter portions 21a, 21a are formed so that the angle θ1 (see Figure 3) made by a straight line connecting the corresponding positions of the two large diameter portions 21a, 21a and the axis X is approximately the same as the inclination angle θ2 (see Figure 4) of the pressing portion 41 of the fixing member 4 described later. Here, the corresponding positions of the two large diameter portions 21a, 21a refer to, for example, the position of the boundary between the cylindrical portion C and the step portion 21c in one large diameter portion 21a and the position of the boundary between the cylindrical portion C and the step portion 21c in the other large diameter portion 21a, and the position of the boundary between the inclined portion S and the cylindrical portion C in one large diameter portion 21a and the position of the boundary between the inclined portion S and the cylindrical portion C in the other large diameter portion 21a. Since the angle θ1 between the line connecting the two large diameter portions 21a, 21a and the axis X and the inclination angle θ2 of the pressing portion 41 are substantially the same, the pressing force from the pressing portion 41 is applied substantially evenly to the two large diameter portions 21a, 21a. Therefore, it is possible to suppress the tube T from being easily detached due to partial deterioration of the large diameter portion 21a or the tube T. In this embodiment, there are two sets of the large diameter portion 21a and the small diameter portion 21b, but there may be one or three or more sets.

[0017] 1, in this embodiment, the joint body 2 has a male threaded portion 22 that screws into a female threaded portion 43 of the fixing member 4 (described later) at a position adjacent to the insertion portion 21 on the first direction D1 side of the insertion portion 21 for connection to the fixing member 4. The joint body 2 is connected to the fixing member 4 by screwing the male threaded portion 22 of the joint body 2 into the female threaded portion 43 of the fixing member 4. In this embodiment, the joint body 2 has a screw configuration for connection to the fixing member 4, but may have another connection configuration such as a snap fit configuration as long as it can be connected to the fixing member 4.

[0018] The joint body 2 may be made of any material that is suppressed from deforming when the fixing member 4 is connected and the tube T is fixed, and the material is not particularly limited. The joint body 2 is preferably made of a synthetic resin, for example, taking into consideration thermal expansion. For example, the joint body 2 may be made of one or more materials selected from the group consisting of polypropylene (PP), polyethylene (PE), polyamide (PA), polyvinyl chloride (PVC), polyacetal (POM), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), perfluoroethylene propene copolymer (FEP), polyvinylidene fluoride (PVDF), and polyether ether ketone (PEEK).

[0019] As shown in FIG. 1, the sleeve 3 is a substantially cylindrical member that is fitted around the outer periphery of the tube T so as to be movable along the axial direction X of the tube T. The shape of the sleeve 3 is not particularly limited as long as it can be fitted around the tube T. In this embodiment, as shown in FIG. 5A, the sleeve 3 has an end 3a on the first direction D1 side in the axial direction X, an end 3b on the second direction D2 side in the axial direction X, and an inner circumferential surface 3c that extends with substantially the same diameter along the axial direction X between both ends 3a and 3b. As shown in FIG. 5C, when the fixing member 4 is connected to the joint main body 2 to which the tube T is connected, the sleeve 3 is configured to be disposed between the outer fitting portion TA of the tube T that is fitted around the insertion portion 21 and a pressing portion 41 of the fixing member 4, which will be described later. The sleeve 3 is disposed between the outer fitting portion TA of the tube T and the pressing portion 41 of the fixing member 4, and the pressing force of the pressing portion 41 presses the outer fitting portion TA of the tube T from the outer periphery side to the insertion portion 21 on the inside in the radial direction RD. As a result, the outer fitting portion TA of the tube T is fixed to the insertion portion 21, and the tube T is prevented from coming off the joint 1.

[0020] The sleeve 3 may be made of a material having flexibility and elastic restoring force, as long as it can press the outer fitting portion TA of the tube T by the pressing force of the pressing portion 41 of the fixing member 4. In this case, the sleeve 3 itself has a function of pressing the outer fitting portion TA of the tube T from the outer periphery side toward the inside in the radial direction RD. The sleeve 3 has an inner diameter smaller than the outer diameter of the outer fitting portion TA of the tube T, and when fitted onto the outer fitting portion TA of the tube T, the sleeve 3 expands in diameter and generates an elastic restoring force that tries to reduce the diameter to the original diameter. The sleeve 3 can press the outer fitting portion TA of the tube T against not only the large diameter portion 21a but also the small diameter portion 21b of the insertion portion 21 by the elastic restoring force, so that the tube T can be further prevented from coming off. Even if the fixing member 4 is disconnected from the joint body 2, the sleeve 3 maintains the state of being fitted onto the outer fitting portion TA of the tube T by the elastic restoring force of the sleeve 3. The sleeve 3, which remains fitted onto the outer fitting portion TA of the tube T, can press the outer fitting portion TA of the tube T inward in the radial direction RD, so that even if the fixing member 4 is disconnected from the fitting body 2, the tube T can be prevented from coming off from the fitting body 2.

[0021] The fixing member 4 is a member that fixes the tube T to the joint body 2 by being connected to the joint body 2. As shown in FIG. 1, the fixing member 4 is provided on the outer circumferential side of the tube T so as to be movable along the axial direction X of the tube T. The fixing member 4 can be connected to the joint body 2 by moving relatively in a first direction D1, which is a direction toward the joint body 2 along the axial direction X of the tube T. In this embodiment, the fixing member 4 is formed in a cylindrical shape extending along the axial direction X, into which the tube T and the sleeve 3 can be inserted, has an inner cavity that is approximately coaxial with the central axis X of the tube T, and is formed in a cylindrical shape extending along the axial direction X. As shown in FIG. 4 and FIG. 5A to FIG. 5C, the fixing member 4 includes, on an inner wall surface surrounding the inner cavity, a pressing portion 41 that presses the outer fitting portion TA of the tube T from the outer circumferential side, and an abutting portion 42 that abuts against the sleeve 3 in the axial direction X. In this embodiment, the fixing member 4 has a female screw portion 43 provided on the inner wall surface adjacent to the pressing portion 41 on the first direction D1 side in the axial X direction. When the male screw portion 22 of the joint body 2 and the female screw portion 43 of the fixing member 4 are screwed together, the fixing member 4 moves relatively in the first direction D1 along the axial X direction, and after screwing, the fixing member 4 is connected to the joint body 2 and is suppressed from moving relatively along the axial X direction with respect to the joint body 2. However, the fixing member 4 may be connected to the joint body 2 by other connection configurations such as a snap fit configuration as long as it can be connected to the joint body 2 by moving relatively in the first direction D1 along the axial X direction. The fixing member 4 is not particularly limited in terms of its constituent material as long as it is made of a material that is suppressed from deforming when it is connected to the joint body 2 and the tube T is fixed to the joint body 2, and can be made of the same material as the joint body 2.

[0022] As shown in FIG. 5C, the pressing portion 41 presses the outer fitting portion TA of the tube T fitted on the insertion portion 21 from the outer periphery side to the insertion portion 21 on the inside in the radial direction RD via the sleeve 3 in a state where the fixing member 4 is connected to the joint body 2. The tube T is pressed against the insertion portion 21 by the pressing portion 41, so that the engagement with the insertion portion 21 is strengthened and the tube T is prevented from coming off the joint 1. The pressing portion 41 is formed by an inner circumferential surface having an inner diameter larger than at least the outer diameter of the insertion portion 21, and only needs to be able to press the outer fitting portion TA of the tube T from the outer periphery side to the inside in the radial direction RD, and its structure is not particularly limited. In this embodiment, the pressing portion 41 is formed by an inner circumferential surface having an inner diameter smaller than the outer diameter of the sleeve 3 in a state where the pressing portion 41 is fitted on the outer fitting portion TA of the tube T. As a result, when the pressing portion 41 is located on the outer periphery side of the sleeve 3 in a state where the pressing portion 41 is fitted on the outer fitting portion TA of the tube T, the pressing portion 41 presses the tube T inward in the radial direction RD via the sleeve 3. In this embodiment, as shown in Fig. 4, the inner circumferential surface forming the pressing portion 41 has a shape that expands in diameter toward the first direction D1 in the axial direction of the X axis, and is inclined at an inclination angle θ2 (with respect to the X axis) that is approximately the same as the angle θ1 formed by the two large diameter portions 21a, 21a of the insertion portion 21 of the joint body 2 described above. This allows the pressing portion 41 to apply a pressing force to the two large diameter portions 21a, 21a approximately evenly, thereby suppressing partial deterioration of the large diameter portions 21a and the tube T and suppressing the tube T from becoming easily detached. However, the inner circumferential surface forming the pressing portion 41 may be formed approximately parallel to the X axis, or may be inclined at an angle larger or smaller than the angle θ1.

[0023] 5B and 5C, for example, when the fixing member 4 is connected to the joint body 2, the abutment portion 42 is a portion that can abut against the sleeve 3 in the axial X direction so as to suppress relative movement of the sleeve 3 with respect to the fixing member 4 in a second direction D2 opposite to the first direction D1. By providing the abutment portion 42 to the fixing member 4, when the fixing member 4 is connected to the joint body 2, the sleeve 3 abuts against the abutment portion 42 in the axial X direction and moves relatively in the first direction D1 together with the fixing member 4 in accordance with the relative movement of the fixing member 4 with respect to the joint body 2 in the first direction D1. The abutment portion 42 abuts against the sleeve 3 in the axial X direction and is disposed so as to position at least a portion of the sleeve 3 between the pressing portion 41 of the fixing member 4 and the outer fitting portion TA of the tube T. In this embodiment, as shown in FIG. 4 and FIG. 5A to 5C, the abutment portion 42 is provided adjacent to the end portion of the pressing portion 41 on the second direction D2 side in the axial X direction, and is disposed so as to abut against the end portion 3b of the sleeve 3 on the second direction D2 side. Thereby, the abutment portion 42 can position at least the end portion 3b of the sleeve 3 on the second direction D2 side on the inner periphery side of the pressing portion 41. Furthermore, for example, when the length of the sleeve 3 in the axial X direction is shorter than the length of the pressing portion 41 in the axial X direction as described later, the abutment portion 42 can position the entire sleeve 3 in the axial X direction on the inner periphery side of the pressing portion 41. However, the abutment portion 42 is not limited to the above-mentioned arrangement as long as at least a part of the sleeve 3 can be positioned between the pressing portion 41 and the outer fitting portion TA of the tube T, and may be disposed away from the end portion of the pressing portion 41 on the second direction D2 side, or may be disposed so as to abut against another portion of the sleeve 3. Furthermore, the structure of the abutment portion 42 is not particularly limited as long as it can suppress the relative movement of the sleeve 3 in the second direction D2 with respect to the fixed member 4. For example, as shown in FIG. 4, the abutment portion 42 can be configured as a wall surface that is approximately perpendicular to the axial X direction.

[0024] As shown in Fig. 5B and Fig. 5C, when the fixing member 4 moves relatively in the first direction D1 for connection with the joint body 2, the pressing portion 41 and the abutting portion 42 press the outer peripheral surface TAs of the outer fitting portion TA of the tube T inward in the radial direction RD and in the first direction D1 via the sleeve 3. As shown in Fig. 5C, the fixing member 4 is configured such that the pressing portion 41 and the abutting portion 42 press the outer peripheral surface TAs of the outer fitting portion TA of the tube T inward in the radial direction RD and in the first direction D1 via the sleeve 3, thereby plastically deforming the outer peripheral surface TAs of the outer fitting portion TA of the tube T to form a protrusion portion PR on the outer peripheral surface TAs of the outer fitting portion TA of the tube T. The protrusion portion PR formed with the relative movement of the fixing member 4 protrudes outward in the radial direction RD from the outer peripheral surface TAs of the outer fitting portion TA of the tube T, and is configured to be engageable with the sleeve 3 in the axial X direction so as to suppress the relative movement of the tube T in the second direction D2 with respect to the sleeve 3. The protrusion PR formed on the tube T engages with the sleeve 3 in the axial direction X, which is in contact with the abutting portion 42 of the fixing member 4 and is suppressed from moving relative to the fixing member 4 in the second direction D2, thereby suppressing the relative movement of the tube T in the second direction D2 with respect to the fixing member 4. This makes it possible to more firmly fix the tube T to the joint 1, and further suppresses the tube T from coming off the joint 1. Thus, according to the joint 1 of this embodiment, the protrusion PR that can be engaged with the sleeve 3 in the axial direction X can be formed by connecting the fixing member 4 to the joint body 2, so that the tube T can be more firmly fixed to the joint 1. However, although the protrusion PR is formed in conjunction with the connection of the fixing member 4 to the joint body 2 in this embodiment, it is not limited to this embodiment, and may be formed in advance on the outer circumferential surface of the tube T before the fixing member 4 is connected to the joint body 2.

[0025] Since the protrusion PR is formed by plastic deformation of the outer peripheral surface TAs of the outer fitting portion TA of the tube T, even if the pressing force of the fixing member 4 against the outer fitting portion TA of the tube T is released, the protrusion PR is maintained on the outer peripheral surface TAs of the outer fitting portion TA of the tube T. Therefore, even if the fixing member 4 is disconnected from the joint body 2, if the sleeve 3 is made of a material having an elastic restoring force, the elastic restoring force will maintain the state in which the sleeve 3 is fitted onto the outer fitting portion TA of the tube T, and the tube T is prevented from coming off the joint body 2.

[0026] The protrusion PR may be arranged in any manner as long as it is capable of engaging with the sleeve 3 in the axial X direction so as to suppress relative movement of the tube T in the second direction D2 with respect to the sleeve 3. In this embodiment, as shown in Fig. 5C, the protrusion PR is provided adjacent to the end 3a of the sleeve 3 on the first direction D1 side, and is arranged to engage with the end 3a of the sleeve 3 on the first direction D1 side in the axial X direction. However, the protrusion PR may be arranged to engage with another portion of the sleeve 3 in the axial X direction.

[0027] As described above, the protrusion PR protrudes outward in the radial direction RD from the outer peripheral surface TAs of the outer fitting portion TA of the tube T. The outer peripheral surface TAs of the outer fitting portion TA of the tube T here means the outer surface of the outer fitting portion TA of the tube T in the radial direction RD before the protrusion PR is formed, but in the example shown in FIG. 5C where the protrusion PR is already formed, it means a surface connecting the outer peripheral surfaces TAs1 and TAs2 on both sides in the axial direction X across the portion where the protrusion PR is formed on the outer surface of the outer fitting portion TA of the tube T. Therefore, the protrusion PR has an outer diameter larger than the outer diameter of the outer peripheral surface TAs of the outer fitting portion TA of the tube T. In this embodiment, as shown in FIG. 5C, the protrusion PR has an outer diameter larger than the outer diameter of the outer peripheral surface TAs1 of the portion where the sleeve 3 is fitted and / or the outer peripheral surface TAs2 of the portion where the sleeve 3 is not fitted on both sides in the axial direction X across the portion where the protrusion PR is formed of the outer fitting portion TA of the tube T. The protrusion portion PR protrudes outward in the radial direction RD from the outer peripheral surface TAs of the outer fitting portion TA of the tube T such that the thickness t1 in the radial direction RD of the tube T at the portion where the protrusion portion PR is provided is thicker than the thickness t2 in the radial direction RD of the tube T at the portion where the protrusion portion PR is not provided.

[0028] The projection PR may be configured as an annular projection extending over the entire circumferential direction of the outer circumferential surface TAs of the outer fitting portion TA of the tube T so as to be engageable with the sleeve 3 in the axial direction X, and the shape of the projection PR is not particularly limited. In this embodiment, the projection PR is configured as an annular projection extending over the entire circumferential direction of the outer circumferential surface TAs of the outer fitting portion TA of the tube T. This increases the engagement force of the projection PR, and further suppresses the tube T from coming off. However, the projection PR may be configured as a partial annular projection protruding partially along the circumferential direction of the outer circumferential surface TAs of the outer fitting portion TA of the tube T. In this embodiment, as shown in FIG. 5C, in a cross-sectional view cut along the axial direction X, the projection PR is formed in a substantially triangular shape whose length in the axial direction X gradually decreases as it moves away from the outer circumferential surface TAs of the outer fitting portion TA of the tube T toward the radial direction RD. The projection PR is formed so that its length in the axial direction X is longest at the portion connected to the outer circumferential surface TAs of the outer fitting portion TA of the tube T, so that the projection PR is more stably held by the outer fitting portion TA of the tube T. As can be clearly seen in FIG. 5B, the outer fitting portion TA of the tube T has a portion curved convexly outward in the radial direction RD by the protrusion 21a provided on the insertion portion 21 of the joint body 2, but the protrusion PR has a shorter length in the axial direction X than the curved portion and protrudes steeply at a large inclination angle as shown in FIG. 5C. This makes it more difficult for the sleeve 3 to overcome the protrusion PR when moving relatively along the axial direction X compared to the curved portion, and allows for stronger engagement with the protrusion PR. For example, the inclination angle of the side of the protrusion PR on the second direction D2 side that engages with the tube T with respect to the axis X is not particularly limited, but is set to a range of 30° or more and 90° or less, preferably 40° or more and 90° or less, more preferably 50° or more and 90° or less, and even more preferably 60° or more and 90° or less. The inclination angle of the protrusion PR can be adjusted by adjusting the pressing force by the fixing member 4, etc.

[0029] The tube T is not particularly limited as long as it is formed so as to be plastically deformed through the sleeve 3 by at least the pressing force accompanying the relative movement of the fixing member 4, but from the viewpoint of promoting the plastic deformation, it is preferable that the durometer hardness of the tube T is formed within the range of HDA50 or more and HDD60 or less. The durometer hardness is a hardness measured in accordance with JIS K 7215-1986. The material constituting the tube T is not particularly limited, and examples thereof include one or more types selected from the group consisting of rubber, elastomer, polytetrafluoroethylene (PTFE), polyethylene (PE), and polypropylene (PP). The tube T may have a multi-layer structure in which only the outer peripheral surface TAs of the outer fitting portion TA is formed within the above-mentioned durometer hardness range and / or is formed from the above-mentioned material, since the outer peripheral surface TAs of the outer fitting portion TA is subjected to plastic deformation.

[0030] The sleeve 3 is not particularly limited as long as it is formed so as to press and plastically deform the tube T by at least the pressing force caused by the relative movement of the fixing member 4, but from the viewpoint of promoting plastic deformation, it is preferable that the durometer hardness of the sleeve 3 is formed within a range of HDD55 or more and HDD75 or less, and is greater than the durometer hardness of the tube T. However, even if the hardness of the sleeve 3 is outside the above range, it may be formed so as to have a hardness that causes plastic deformation of the tube T when compressed by the pressing force of the fixing member 4. The material constituting the sleeve 3 is not particularly limited, and examples thereof include one or more selected from the group consisting of perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), high density polyethylene (HDPE), polyacrylate (PA), polyurethane (PU), and polyvinyl chloride (PVC).

[0031] The outer diameter of the insertion part 21 of the joint body 2, the inner and outer diameters of the tube T, the inner and outer diameters of the sleeve 3, and the inner diameter of the pressing part 41 of the fixing member 4 can be appropriately set so that the outer peripheral surface TAs of the outer fitting part TA of the tube T is plastically deformed via the sleeve 3 by the pressing force of the fixing member 4, and the protrusion part PR is formed. For example, the inner diameter of the tube T is set to a size smaller than the maximum outer diameter of the insertion part 21 and expanded when the tube T is fitted onto the insertion part 21. The inner diameter of the sleeve 3 is set to a size smaller than the maximum outer diameter of the outer fitting part TA of the tube T fitted onto the insertion part 21 and expanded when the sleeve 3 is fitted onto the outer fitting part TA of the tube T. The inner diameter of the pressing part 41 is set to a size smaller than the maximum outer diameter of the sleeve 3 fitted onto the outer fitting part TA of the tube T, and pressed against the tube T inward in the radial direction RD via the sleeve 3 when the pressing part 41 is disposed on the outer peripheral side of the sleeve 3. Specifically, the inner diameter of the tube T is set to 60% to 90%, preferably 65% ​​to 85%, more preferably 70% to 80%, and even more preferably 75% to 80% of the maximum outer diameter of the insertion portion 21. The inner diameter of the sleeve 3 is set to 87% to 98%, preferably 89% to 96%, more preferably 91% to 94%, and even more preferably 93% to 94% of the maximum outer diameter of the outer fitting portion TA of the tube T. The inner diameter of the pressing portion 41 is set to 91% to 99%, preferably 93% to 99%, more preferably 95% to 99%, and even more preferably 97% to 99% of the maximum outer diameter of the sleeve 3 fitted onto the outer fitting portion TA of the tube T.

[0032] The sleeve 3 is not particularly limited in structure, as long as it is formed so that the tube T is pressed and plastically deformed by at least the pressing force caused by the relative movement of the fixing member 4, and a protrusion portion PR is formed on the outer peripheral surface TAs of the outer fitting portion TA of the tube T. In this embodiment, the sleeve 3 is formed so that, as shown in FIG. 5B, when the fixing member 4 presses the outer peripheral surface TAs of the outer fitting portion TA of the tube T inward in the radial direction RD and in the first direction D1 via the sleeve 3, the inner peripheral surface 3c of the sleeve 3 near the end portion 3a on the first direction D1 side of the sleeve 3 comes into contact with the outer peripheral surface TAs of the outer fitting portion TA of the tube T. As a result, the outer peripheral surface TAs of the tube T is pressed via the sleeve 3 near the end portion 3a on the first direction D1 side of the sleeve 3 that moves relatively in the first direction D1 together with the fixing member 4, so that a protrusion portion PR is formed near the end portion 3a on the first direction D1 side of the sleeve 3. In this embodiment, the sleeve 3 is formed in a substantially straight cylindrical shape extending along the axial direction with substantially the same inner diameter when not fitted onto the outer fitting portion TA of the tube T (see FIG. 5A ), and is configured so that when fitted onto the outer fitting portion TA of the tube T, the entire inner circumferential surface 3c of the sleeve 3 in the axial direction contacts the outer circumferential surface TAs of the outer fitting portion TA of the tube T. However, the sleeve 3 may be configured so that the inner diameter changes along the axial direction, and only the inner circumferential surface of the sleeve 3 other than the inner circumferential surface 3c of the sleeve 3 in the vicinity of the end portion 3a of the sleeve 3 on the first direction D1 side contacts the outer circumferential surface TAs of the outer fitting portion TA of the tube T. In that case, a protrusion PR is formed adjacent to the contact portion.

[0033] 5A, in this embodiment, the sleeve 3 is formed so that the end 3a of the sleeve 3 on the first direction D1 side has a surface that is approximately perpendicular to the axial direction X. This makes it easier for the end 3a of the sleeve 3 on the first direction D1 side to press the outer circumferential surface TAs of the outer fitting portion TA of the tube T in the first direction D1 side, facilitating the formation of the protrusion PR. From a similar viewpoint, the end 3a of the sleeve 3 on the first direction D1 side may have a surface that slopes toward the second direction D2 side from the inner side in the radial direction RD of the sleeve 3 toward the outer side in the radial direction RD.

[0034] In this embodiment, as shown in Fig. 5B and Fig. 5C, the sleeve 3 is formed so that the length in the axial X direction of the sleeve 3 is shorter than the length in the axial X direction of the pressing portion 41 of the fixing member 4. As a result, a space for forming the protrusion PR is formed between the pressing portion 41 of the fixing member 4 and the outer fitting portion TA of the tube T, and the formation of the protrusion PR is promoted. However, as long as a space for forming the protrusion PR can be secured between the inner wall surface other than the pressing portion 41 of the fixing member 4 and the outer fitting portion TA of the tube T, the length in the axial X direction of the sleeve 3 may be the same as or longer than the length in the axial X direction of the pressing portion 41 of the fixing member 4. The sleeve 3 is not particularly limited, but it is preferable that the end portion 3a of the sleeve 3 on the first direction D1 side has a length in the axial X direction such that, when the fixing member 4 is connected to the joint body 2, the end portion 3a of the sleeve 3 on the first direction D1 side is positioned near the end portion on the first direction D1 side of the large diameter portion 21a of the insertion portion 21 of the joint body 2 or at the small diameter portion 21b. The outer fitting portion TA of the tube T fitted onto the insertion portion 21 has the largest diameter at a portion corresponding to the large diameter portion 21a of the insertion portion 21. This portion of the outer fitting portion TA of the tube T that has the largest diameter is subject to the largest pressing force when the sleeve 3 passes in the first direction D1, and is therefore prone to plastic deformation. Therefore, by positioning the end portion 3a on the first direction D1 side of the sleeve 3 that moves relatively in the first direction D1 and stops near the end portion on the first direction D1 side of the large diameter portion 21a or the small diameter portion 21b, plastic deformation of the outer peripheral surface TAs of the outer fitting portion TA of the tube T is promoted, and the protrusion portion PR is easily formed.

[0035] Next, a method of fixing the tube T to the fitting 1 of the present embodiment described above (hereinafter simply referred to as the "fixing method") will be described with reference to Fig. 1 and Figs. 5A to 5C. A number of steps will be described below, but the steps may be performed in the order described below, or in an order different from the order described below. Furthermore, the matters described above regarding the fitting 1 of the present embodiment are also applicable to the fixing method of the present embodiment, and the matters described below regarding the fixing method of the present embodiment are also applicable to the fitting 1 of the present embodiment. Note that the following description is an example, and the method of fixing a tube to a fitting of the present invention is not limited to the following description.

[0036] 1, the fixing method of this embodiment includes a step of providing a fixing member 4 on the outer circumferential side of the tube T, and a step of fitting a sleeve 3 onto the tube T on the first direction D1 side of the fixing member 4. In the state shown in Fig. 1, the sleeve 3 and the fixing member 4 have inner diameters larger than the outer diameter of the tube T, and therefore are movable relative to the tube T along the axial X direction.

[0037] The fixing method includes a step of moving the tube T from the state shown in Fig. 1 in a first direction D1 along the axial direction X to fit the tube T onto the insertion portion 21 of the joint body 2, as shown in Fig. 5A. Since the insertion portion 21 has an outer diameter larger than the inner diameter of the tube T, the tube T is expanded in diameter and fitted onto the insertion portion 21.

[0038] The fixing method includes a step of moving the fixing member 4 relatively in a first direction D1 along the axis X direction from the state shown in Fig. 5A to the state shown in Fig. 5B and 5C, and connecting it to the fitting body 2, thereby fixing the tube T to the fitting body 2. The fixing member 4 is rotated relatively to the fitting body 2 about the axis X from the state shown in Fig. 5B to the state shown in Fig. 5C, so that the female threaded portion 43 of the fixing member 4 and the male threaded portion 22 of the fitting body 2 screw together and advance in the first direction D1 along the axis X direction, and when the screwing is completed, the fixing member 4 is connected to the fitting body 2. When the screwing between the female thread portion 43 of the fixing member 4 and the male thread portion 22 of the fitting body 2 is completed (the state shown in Figure 5C), the sleeve 3 is placed between the pressing portion 41 of the fixing member 4 and the outer fitting portion TA of the tube T, and the pressing portion 41 presses the outer fitting portion TA against the insertion portion 21 on the inside in the radial direction RD via the sleeve 3, thereby fixing the tube T to the fitting 1.

[0039] The fixing method further includes a step of pressing the outer peripheral surface TAs of the outer fitting portion TA of the tube T inward in the radial direction RD and in the first direction D1 via the sleeve 3 by the pressing portion 41 and the abutting portion 42 when the fixing member 4 is moved relatively in the first direction D1 to connect the fixing member 4 to the joint body 2, thereby plastically deforming the outer peripheral surface TAs of the outer fitting portion TA of the tube T and forming a protrusion PR on the outer peripheral surface TAs of the outer fitting portion TA of the tube T, as shown in FIG. 5C. According to the fixing method of this embodiment, the protrusion PR that can be engaged with the sleeve 3 in the axial X direction can be formed, so that the tube T can be fixed to the joint 1 more firmly. Also, according to the fixing method of this embodiment, the protrusion PR can be formed when the fixing member 4 is connected to the joint body 2 and the tube T is fixed to the joint 1, so that the step of providing the protrusion PR in advance on the tube T can be omitted, and the manufacturing process of the tube T can be simplified. Furthermore, according to the fixing method of this embodiment, the tube T is plastically deformed by the pressing force through the sleeve 3, and the protrusion PR can be formed adjacent to the sleeve 3 in the axial direction X, making it easier to position the sleeve 3 with respect to the protrusion PR compared to a case in which the tube T is provided with the protrusion PR in advance. Therefore, it is possible to more reliably prevent the tube T from coming off the joint 1.

[0040] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. Note that the above embodiment mainly describes the invention having the following configuration.

[0041] (1) A joint to which a substantially cylindrical tube is fixed, the joint comprising: a fitting body having an insertion portion into which the tube is fitted; a substantially cylindrical sleeve that is fitted around an outer circumferential side of the tube so as to be movable along an axial direction of the tube; a fixing member that is provided on an outer circumferential side of the tube so as to be movable along an axial direction of the tube, and that is connectable to the joint body by relatively moving in a first direction that is a direction toward the joint body along the axial direction of the tube; Equipped with The fixing member is a pressing portion that presses an outer fitting portion of the tube that is fitted onto the insertion portion from an outer circumferential side to the insertion portion on a radially inner side; a contact portion capable of contacting the sleeve in the axial direction so as to suppress relative movement of the sleeve with respect to the fixed member in a second direction opposite to the first direction; having the sleeve is configured such that, when the fixing member is connected to the joint body, the sleeve abuts against the abutment portion in the axial direction and moves relatively in the first direction together with the fixing member in accordance with relative movement of the fixing member in the first direction with respect to the joint body, and is disposed between the outer fitting portion of the tube and the pressing portion of the fixing member when the fixing member is connected to the joint body; the fixing member is configured such that, when moving relatively in the first direction for connection with the fitting body, the pressing portion and the abutment portion press an outer peripheral surface of the outer fitting portion of the tube inward in the radial direction and in the first direction via the sleeve, thereby plastically deforming the outer peripheral surface of the outer fitting portion of the tube and forming a protrusion on the outer peripheral surface of the outer fitting portion of the tube, The protrusion protrudes radially outward from an outer circumferential surface of the outer fitting portion of the tube and is configured to be engageable with the sleeve in the axial direction so as to suppress relative movement of the tube with respect to the sleeve in the second direction. Fitting.

[0042] (2) The tube is formed so that the durometer hardness of the tube is within a range of HDA50 or more and HDD60 or less, The sleeve is formed so that the durometer hardness of the sleeve is equal to or greater than HDD55 and equal to or less than HDD75, and is greater than the durometer hardness of the tube. (1) A fitting as described above.

[0043] (3) The sleeve is formed such that an inner circumferential surface of the sleeve near an end of the sleeve on the first direction side is in contact with an outer circumferential surface of the outer fitting portion of the tube. A fitting as described in (1) or (2).

[0044] (4) The sleeve is formed such that the axial length of the sleeve is shorter than the axial length of the pressing portion of the fixing member. A joint according to any one of (1) to (3).

[0045] (5) The insertion portion of the joint body includes at least one large diameter portion and at least one small diameter portion provided continuously with the large diameter portion on the first direction side of the large diameter portion, the sleeve has an axial length such that an end portion of the sleeve on the first direction side is positioned near an end portion of the large diameter portion on the first direction side or at the small diameter portion when the fixing member is connected to the joint body. A joint according to any one of (1) to (4).

[0046] (6) A method for fastening a generally cylindrical tube to a fitting, comprising the steps of: The joint is a fitting body having an insertion portion into which the tube is fitted; a substantially cylindrical sleeve that is fitted around an outer circumferential side of the tube so as to be movable along an axial direction of the tube; a fixing member that is provided on an outer circumferential side of the tube so as to be movable along an axial direction of the tube, and that is connectable to the joint body by relatively moving in a first direction that is a direction toward the joint body along the axial direction of the tube; Equipped with The fixing member is a pressing portion that presses an outer fitting portion of the tube that is fitted onto the insertion portion from an outer circumferential side to the insertion portion on a radially inner side; a contact portion capable of contacting the sleeve in the axial direction so as to suppress relative movement of the sleeve with respect to the fixed member in a second direction opposite to the first direction; having the sleeve is configured such that, when the fixing member is connected to the joint body, the sleeve abuts against the abutment portion in the axial direction and moves relatively in the first direction together with the fixing member in accordance with relative movement of the fixing member in the first direction with respect to the joint body, and is disposed between the outer fitting portion of the tube and the pressing portion of the fixing member when the fixing member is connected to the joint body; The method further comprising: providing the fixing member on an outer circumferential side of the tube; fitting the sleeve onto the tube on the first direction side of the fixing member; fitting the tube onto the insertion portion of the joint body; a step of relatively moving the fixing member in a first direction along the axial direction and connecting the fixing member to the joint body, thereby fixing the tube to the joint body; Including, The method further comprises: a step of pressing an outer circumferential surface of the outer fitting portion of the tube radially inward and in the first direction via the sleeve by the pressing portion and the abutting portion to plastically deform the outer circumferential surface of the outer fitting portion of the tube, when the fixing member is moved relatively in the first direction to connect the fixing member to the joint body, thereby forming a protrusion on the outer circumferential surface of the outer fitting portion of the tube, The protrusion protrudes radially outward from an outer circumferential surface of the outer fitting portion of the tube and is configured to be engageable with the sleeve in the axial direction so as to suppress relative movement of the tube with respect to the sleeve in the second direction. method.

[0047] (7) The tube is formed so that the durometer hardness of the tube is within a range of HDA50 or more and HDD60 or less, The sleeve is formed so that the durometer hardness of the sleeve is equal to or greater than HDD55 and equal to or less than HDD75, and is greater than the durometer hardness of the tube. The method according to (6).

[0048] (8) The sleeve is formed such that an inner circumferential surface of the sleeve near an end of the sleeve on the first direction side is in contact with an outer circumferential surface of the outer fitting portion of the tube. The method according to (6) or (7).

[0049] (9) The sleeve is formed so that the axial length of the sleeve is shorter than the axial length of the pressing portion of the fixing member. The method according to any one of (5) to (8).

[0050] (10) The insertion portion of the joint body includes at least one large diameter portion and at least one small diameter portion provided continuously with the large diameter portion on the first direction side of the large diameter portion, the sleeve has an axial length such that an end portion of the sleeve on the first direction side is positioned near an end portion of the large diameter portion on the first direction side or at the small diameter portion when the fixing member is connected to the joint body. The method according to any one of (5) to (9).

[0051] (11) a joint; A generally cylindrical tube fixed to the joint; A joint structure comprising: The joint is a fitting body having an insertion portion into which the tube is fitted; a substantially cylindrical sleeve that is fitted around an outer circumferential side of the tube so as to be movable along an axial direction of the tube; a fixing member that is provided on an outer circumferential side of the tube so as to be movable along an axial direction of the tube, and that is connectable to the joint body by relatively moving in a first direction that is a direction toward the joint body along the axial direction of the tube; Equipped with The fixing member is a pressing portion that presses an outer fitting portion of the tube that is fitted onto the insertion portion from an outer circumferential side to the insertion portion on a radially inner side; a contact portion capable of contacting the sleeve in the axial direction so as to suppress relative movement of the sleeve with respect to the fixed member in a second direction opposite to the first direction; having the sleeve is configured such that, when the fixing member is connected to the joint body, the sleeve abuts against the abutment portion in the axial direction and moves relatively in the first direction together with the fixing member in accordance with relative movement of the fixing member in the first direction with respect to the joint body, and is disposed between the outer fitting portion of the tube and the pressing portion of the fixing member when the fixing member is connected to the joint body; the tube has a protrusion protruding radially outward from an outer circumferential surface of the outer fitting portion of the tube, The protrusion is configured to be engageable with the sleeve in the axial direction so as to suppress relative movement of the tube with respect to the sleeve in the second direction. Joint structure.

[0052] (12) When the fixing member moves relatively in the first direction for connection with the fitting body, the pressing portion and the abutting portion press the outer peripheral surface of the outer fitting portion of the tube inward in the radial direction and in the first direction via the sleeve, thereby plastically deforming the outer peripheral surface of the outer fitting portion of the tube and forming the protrusion on the outer peripheral surface of the outer fitting portion of the tube. A joint structure as described in (11).

[0053] (13) The tube is formed so that the durometer hardness of the tube is in the range of HDA50 or more and HDD60 or less, The sleeve is formed so that the durometer hardness of the sleeve is equal to or greater than HDD55 and equal to or less than HDD75, and is greater than the durometer hardness of the tube. A joint structure according to (11) or (12).

[0054] (14) The sleeve is formed such that an inner circumferential surface of the sleeve near an end of the sleeve on the first direction side is in contact with an outer circumferential surface of the outer fitting portion of the tube. The joint structure according to any one of (11) to (13).

[0055] (15) The sleeve is formed such that an axial length of the sleeve is shorter than an axial length of the pressing portion of the fixing member. The joint structure according to any one of (11) to (14).

[0056] (16) The insertion portion of the joint body includes at least one large diameter portion and at least one small diameter portion provided continuously with the large diameter portion on the first direction side of the large diameter portion, the sleeve has an axial length such that an end portion of the sleeve on the first direction side is positioned near an end portion of the large diameter portion on the first direction side or at the small diameter portion when the fixing member is connected to the joint body. The joint structure according to any one of (11) to (15). [Explanation of symbols]

[0057] 1. Joint 2. Joint body 21 Insertion section 21a Large diameter part (projection) 21b Small diameter section 21c Step 22 Male thread 3 Sleeve 3a End portion on the first direction side 3b End portion on the second direction side 3c Inner surface 4 Fixing member 41 Pressing part 42 Contact part 43 Female thread C Cylinder section D1 1st direction D2 2nd direction PR protrusion RD radial direction S slope part T-Tube TA external fitting part TAs outer surface TAs1: Outer surface of the part where the sleeve is fitted TAs2 Outer surface of part where sleeve is not fitted t1: Radial thickness of the tube at the location where the protrusion is provided t2 Radial thickness of the tube where no protrusion is provided X center axis θ1 The angle between the axis and the straight line connecting the corresponding positions of the two large diameter parts θ2 Inclined angle of the pressing part

Claims

1. A joint to which a substantially cylindrical tube is fixed, the joint comprising: a fitting body having an insertion portion into which the tube is fitted; a substantially cylindrical sleeve that is fitted around an outer circumferential side of the tube so as to be movable along an axial direction of the tube; a fixing member that is provided on an outer circumferential side of the tube so as to be movable along an axial direction of the tube, and that is connectable to the joint body by relatively moving in a first direction that is a direction toward the joint body along the axial direction of the tube; Equipped with The fixing member is a pressing portion that presses an outer fitting portion of the tube that is fitted onto the insertion portion from an outer circumferential side to the insertion portion on a radially inner side; a contact portion capable of contacting the sleeve in the axial direction so as to suppress relative movement of the sleeve with respect to the fixed member in a second direction opposite to the first direction; having the sleeve is configured such that, when the fixing member is connected to the joint body, the sleeve abuts against the abutment portion in the axial direction and moves relatively in the first direction together with the fixing member in accordance with relative movement of the fixing member in the first direction with respect to the joint body, and is disposed between the outer fitting portion of the tube and the pressing portion of the fixing member when the fixing member is connected to the joint body, the fixing member is configured such that, when moving relatively in the first direction for connection with the fitting body, the pressing portion and the abutment portion press an outer peripheral surface of the outer fitting portion of the tube inward in the radial direction and in the first direction via the sleeve, thereby plastically deforming the outer peripheral surface of the outer fitting portion of the tube and forming a protrusion on the outer peripheral surface of the outer fitting portion of the tube, The protrusion protrudes radially outward from an outer circumferential surface of the outer fitting portion of the tube and is configured to be engageable with the sleeve in the axial direction so as to suppress relative movement of the tube with respect to the sleeve in the second direction. Fitting.

2. The tube is formed so that the durometer hardness of the tube is within a range of HDA50 or more and HDD60 or less, The sleeve is formed so that the durometer hardness of the sleeve is equal to or greater than HDD55 and equal to or less than HDD75, and is greater than the durometer hardness of the tube. The joint of claim 1.

3. The sleeve is formed such that an inner circumferential surface of the sleeve near an end of the sleeve on the first direction side is in contact with an outer circumferential surface of the outer fitting portion of the tube. A joint according to claim 1 or 2.

4. The sleeve is formed such that an axial length of the sleeve is shorter than an axial length of the pressing portion of the fixing member. A joint according to claim 1 or 2.

5. The insertion portion of the joint body includes at least one large diameter portion and at least one small diameter portion provided continuously with the large diameter portion on the first direction side of the large diameter portion, the sleeve has an axial length such that an end portion of the sleeve on the first direction side is positioned near an end portion of the large diameter portion on the first direction side or at the small diameter portion when the fixing member is connected to the joint body. A joint according to claim 1 or 2.

6. 1. A method for fastening a generally cylindrical tube to a fitting, comprising the steps of: The joint is a fitting body having an insertion portion into which the tube is fitted; a substantially cylindrical sleeve that is fitted around an outer circumferential side of the tube so as to be movable along an axial direction of the tube; a fixing member that is provided on an outer circumferential side of the tube so as to be movable along an axial direction of the tube, and that is connectable to the joint body by relatively moving in a first direction that is a direction toward the joint body along the axial direction of the tube; Equipped with The fixing member is a pressing portion that presses an outer fitting portion of the tube that is fitted onto the insertion portion from an outer circumferential side to the insertion portion on a radially inner side; a contact portion capable of contacting the sleeve in the axial direction so as to suppress relative movement of the sleeve with respect to the fixed member in a second direction opposite to the first direction; having the sleeve is configured such that, when the fixing member is connected to the joint body, the sleeve abuts against the abutment portion in the axial direction and moves relatively in the first direction together with the fixing member in accordance with relative movement of the fixing member in the first direction with respect to the joint body, and is disposed between the outer fitting portion of the tube and the pressing portion of the fixing member when the fixing member is connected to the joint body, The method further comprising: providing the fixing member on an outer circumferential side of the tube; fitting the sleeve onto the tube on the first direction side of the fixing member; fitting the tube onto the insertion portion of the joint body; a step of relatively moving the fixing member in a first direction along the axial direction and connecting the fixing member to the joint body, thereby fixing the tube to the joint body; Including, The method further comprises: a step of pressing an outer circumferential surface of the outer fitting portion of the tube inward in the radial direction and in the first direction via the sleeve by the pressing portion and the abutting portion to plastically deform the outer circumferential surface of the outer fitting portion of the tube, when the fixing member is moved relatively in the first direction to connect the fixing member to the joint body, thereby forming a protrusion on the outer circumferential surface of the outer fitting portion of the tube, The protrusion protrudes radially outward from an outer circumferential surface of the outer fitting portion of the tube and is configured to be engageable with the sleeve in the axial direction so as to suppress relative movement of the tube with respect to the sleeve in the second direction. method.

Images