Joint structure

Abstract

To provide a joint structure which is easily manufactured and which can be provided with stable quality.SOLUTION: A joint structure S10 includes: a metal core body 14 having a hanging part 24 which hangs to one end side in an axial direction radially outward, and a groove part 26 continuously formed along a circumferential direction on an outer peripheral surface 25 of the other end side in an axial direction with respect to the hanging part 24; a nut 16 into which the hanging part 24 is inserted, the nut 16 including a hooking part 34 with an inner diameter smaller than that of the hanging part 24 and a female screw part 32; and a cylindrical outer member 18 made of metal having a holding part 42 provided on an outer peripheral side on the other end in the axial direction with respect to the nut 16 on the core body 14 and on which a tool is hooked, and a deforming part 45 formed of a thin part 44 with a smaller thickness than the holding part 42 and fixed to the core body 14 by being engaged with the groove part 26 by plastic deformation upon fastening from outside.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a joint structure. [Background technology]

[0002] The following Patent Document 1 discloses a fitting in which a core metal fitting to which a hose is connected and a seat surface member that abuts against the seat surface of a mating member are constructed as separate members. The core metal fitting has a hexagonal portion for hanging a tool. A nut member is arranged on the outer periphery of the seat surface member.

[0003] In the cap fitting, the nut member is disposed on the outer periphery of the seat surface member, and the seat surface member is fixed to the core metal member to prevent the nut member from falling off. When fixing the seat surface member to the core metal member, the seat surface member is inserted into the inner periphery of the cylindrical core metal member. In this state, the seat surface member is fixed to the core metal member by engaging a round ring with an inner groove formed on the inner periphery of the core metal member and an outer groove formed on the outer periphery of the seat surface member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-211670 Summary of the Invention [Problem to be solved by the invention]

[0005] In the ferrule described in Patent Document 1, the seat surface member is fixed to the core metal by engaging a round ring with an inner groove on the inner peripheral surface of the core metal and an outer groove on the outer peripheral surface of the seat surface member, which makes assembly time-consuming. Furthermore, because it is necessary to align the positions of the inner groove on the inner peripheral surface of the core metal and the outer groove on the outer peripheral surface of the seat surface member and to engage the round ring with the inner groove and outer groove, each component must be manufactured with high precision.

[0006] In addition, as an example where a round ring is not used, the core metal and the seat surface member may be connected by brazing (for example, silver brazing). When connecting by brazing, it relies on manual labor and requires man-hours, making it difficult to stabilize the quality and ensure a stable supply.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide a joint structure that is easy to manufacture and can obtain stable quality. [Means for solving the problem]

[0008] In order to solve the above problems, the joint structure described in the first aspect includes a metal core body having a protrusion that protrudes radially outward on one axial end side and a groove that is continuously formed circumferentially on the outer peripheral surface of the other axial end side relative to the protrusion; a nut member into which the protrusion is inserted, the nut member having a hook portion whose inner diameter is smaller than the protrusion portion and a female thread portion to which a mating member is connected; a cylindrical metal outer member having a gripping portion that is provided on the outer peripheral side of the core body closer to the other axial end side than the nut member in the axial direction and on which a tool can be hung; and a deformation portion that is composed of a thin-walled portion that is thinner than the gripping portion and that engages with the groove portion by plastic deformation when crimped from the outside, thereby being fixed to the core body.

[0009] According to the joint structure described in the first aspect, the metal core body has a protruding portion protruding radially outward at one axial end thereof, and when the protruding portion is inserted into the nut member, the hook portion of the nut member is hooked onto the protruding portion. The core body has a groove formed continuously along the circumferential direction on the outer peripheral surface at the other axial end side relative to the protruding portion, and a metal outer member is provided on the outer peripheral side of the core body closer to the other axial end side relative to the nut member. The outer member is composed of a thin-walled portion that is thinner than the gripping portion on which a tool is attached, and has a deformed portion that engages with the groove through plastic deformation when crimped from the outside and is fixed to the core body. Therefore, the outer member is fixed to the core body by engaging the deformed portion of the outer member with the groove of the core body. This does not rely on manual labor and ensures stable quality compared to when the outer member and the core body are fixed by brazing. In addition, by forming a groove in the core body and tightening a thin-walled portion that is thinner than the gripping portion from the outside, the plastically deformed portion is engaged with the groove, making it easy to manufacture and ensuring a stable supply volume.

[0010] The joint structure described in the second aspect is the joint structure described in the first aspect, wherein the thin-walled portion is provided at the axial end of the outer member on the nut member side relative to the gripping portion, and the core body is provided with the groove portion aligned with the position of the thin-walled portion.

[0011] According to the joint structure of the second aspect, the thin-walled portion is provided at the axial end of the outer member on the nut member side relative to the gripping portion, making it easy to align the thin-walled portion with the groove. Furthermore, by externally crimping the thin-walled portion, the deformed portion that has undergone plastic deformation is engaged with the groove. In this case, since the thin-walled portion at the axial end of the outer member is easily plastically deformed, the deformed portion is easily engaged with the groove, making manufacturing easy.

[0012] The joint structure described in the third aspect is the joint structure described in the first aspect, wherein the thin-walled portion is provided on the opposite side of the gripping portion from the nut member and has a concave shape recessed from the outer surface, and the core body has a groove portion provided in accordance with the position of the thin-walled portion.

[0013] According to the joint structure of the third aspect, the thin-walled portion has a shape recessed from the outer surface, and the deformed portion plastically deformed by crimping the thin-walled portion from the outside is engaged with the groove. At this time, since the thin-walled portion recessed from the outer surface is easily plastically deformed, the deformed portion is easily engaged with the groove, making manufacturing easier.

[0014] The joint structure according to a fourth aspect is the joint structure according to the third aspect, wherein the groove portion has a tapered portion whose outer diameter gradually decreases from the outer peripheral surface on the side of the protruding portion, and a vertical wall portion that protrudes radially outward from the end of the tapered portion opposite the protruding portion, and a corner portion is formed on the inner surface of the thin-walled portion so that the tapered portion and the vertical wall portion can engage with each other by plastic deformation.

[0015] According to the joint structure of the fourth aspect, the groove portion has a tapered portion and a vertical wall portion, and a corner portion is formed on the inner surface of the thin-walled portion so that the corner portion can engage with the tapered portion and the vertical wall portion through plastic deformation. By crimping the thin-walled portion from the outside, the corner portion engages with the tapered portion and the vertical wall portion through plastic deformation. This makes it easier for the deformed portion to engage with the groove portion.

[0016] The joint structure described in a fifth aspect is the joint structure described in the fourth aspect, wherein the groove portion has at least two tapered portions and vertical wall portions alternately formed along the axial direction, and the inner surface of the thin-walled portion is provided with a recess that can be engaged by plastic deformation with an acute-angled corner formed by the at least two alternating vertical wall portions and tapered portions of the intermediate portion in the axial direction.

[0017] According to the joint structure of the fifth aspect, a recess is provided on the inner surface of the thin-walled portion, and by crimping the thin-walled portion from the outside, the recess easily engages with the acute-angled corner formed by the vertical wall portion of the axially intermediate portion and the tapered portion due to plastic deformation, thereby reliably fixing the outer member to the core body. [Effects of the Invention]

[0018] The joint structure of the present invention is easy to manufacture and can provide stable quality. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view cut in half showing a disassembled state before assembly of a connector cap having a joint structure according to a first embodiment. [Figure 2] 1A to 1C are cross-sectional views cut in half illustrating the process of assembling a fitting having a joint structure according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view cut in half illustrating the assembly of a connector fitting having a joint structure according to the first embodiment. [Figure 4] (A) is an enlarged cross-sectional view showing the groove portion of the core body in a fitting having a joint structure according to the first embodiment, (B) is an enlarged cross-sectional view showing the thin-walled portion of the outer member before deformation and the groove portion of the core body, and (C) is an enlarged cross-sectional view showing the deformed portion of the thin-walled portion of the outer member engaged with the groove portion of the core body. [Figure 5] FIG. 1A is a diagram showing a first process of deforming the thin-walled portion of the outer member using a die, and FIG. 1B is a diagram showing a second process of deforming the thin-walled portion of the outer member using a die. [Figure 6] 10 is a cross-sectional view cut in half showing a state in which a mating member is connected to a nut member on one end side of a core body. FIG. [Figure 7] 10 is a cross-sectional view cut in half illustrating the process of connecting a hose to the other end of the core body. FIG. [Figure 8] FIG. 10 is a cross-sectional view cut in half showing a disassembled state before assembly of a connector cap having a joint structure according to a second embodiment. [Figure 9] 10A to 10C are cross-sectional views cut in half showing the assembly process of a fitting having a joint structure according to a second embodiment. [Figure 10] (A) is an enlarged cross-sectional view showing the groove portion of the core body in a fitting having a joint structure according to the second embodiment, (B) is an enlarged cross-sectional view illustrating the process of engaging the thin-walled portion of the outer member with the groove portion of the core body by plastic deformation, and (C) is an enlarged cross-sectional view showing the state in which the deformed portion of the thin-walled portion of the outer member is engaged with the groove portion of the core body. [Figure 11] FIG. 10 is a cross-sectional view cut in half showing a disassembled state before assembly of a connector cap having a joint structure according to a third embodiment. [Figure 12] (A) is a half-cut cross-sectional view showing the assembly process of a mouth fitting having a joint structure relating to the third embodiment, (B) is an enlarged cross-sectional view explaining the process of engaging the thin-walled portion of the outer member with the groove portion of the core body by plastic deformation, and (C) is an enlarged cross-sectional view showing the state in which the deformed portion formed by deforming the thin-walled portion of the outer member is engaged with the groove portion of the core body. [Figure 13] FIG. 10 is a cross-sectional view cut in half showing a disassembled state before assembly of a connector cap having a joint structure according to a fourth embodiment. [Figure 14] 10A is a half-section view showing the assembly process of a fitting having a joint structure according to a fourth embodiment, and FIG. 10B is an enlarged cross-sectional view illustrating the process of engaging the thin-walled portion of the outer member with the groove portion of the core body by plastic deformation. [Figure 15] FIG. 3 is a cross-sectional view cut in half showing the disassembled state before assembly of the closure fitting of the first comparative example. [Figure 16] FIG. 3 is a cross-sectional view cut in half showing the assembled state of the closure of the first comparative example. [Figure 17] FIG. 10 is a schematic view showing a configuration for deforming a part of a nut member used in a cap fitting of a second comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, elements that are less relevant to the present invention are omitted.

[0021] [First embodiment] Fig. 1 is a cross-sectional view cut in half illustrating a disassembled state of a ferrule 12 provided with a joint structure S10 of the first embodiment. Fig. 3 is a cross-sectional view cut in half illustrating the ferrule 12 when assembled.

[0022] (Pipe fittings) 1 and 3, the ferrule 12 includes a core body 14, a nut 16, and an outer member 18. The nut 16 is an example of a nut member.

[0023] (Core body) 1 and 3, the core body 14 is cylindrical and has a flow path 22 arranged in the center along the axial direction. A nut 16 is attached (extrapolated in this embodiment) to an end 14A on one axial end side of the core body 14 (on the left side of the paper in FIG. 1). An outer member 18 is arranged (extrapolated in this embodiment) in the axial middle portion of the core body 14, on the other axial end side of the nut 16 (on the right side of the paper in FIG. 1).

[0024] The core body 14 has an overhang 24 that overhangs radially outward at an end 14A on one axial end side. The core body 14 also has a groove 26 formed on an outer peripheral surface 25 on the other axial end side of the overhang 24. The overhang 24 is formed continuously along the circumferential direction of the core body 14, and the other axial end side of the overhang 24 has a vertical wall 24A arranged in a direction approximately perpendicular to the axial direction. The groove 26 is formed closer to one axial end side than the axial center of the core body 14. The groove 26 is formed continuously along the circumferential direction of the core body 14. An outer member 18 is arranged in the core body 14 at a position including the groove 26.

[0025] As an example, the depth of the groove 26 is about 0.5 mm, and the axial length of the groove 26 is about 7 mm. The depth of the groove 26 is set to a value that will not cause any problems during use (i.e., a value that can withstand pressure) through pressure calculations, depending on the pressure to be used and the diameter and thickness of the core body 14.

[0026] A plurality of annular protrusions 28 are formed on the outer peripheral surface of the core body 14 on the other axial end side of the grooves 26. The outer diameter of the end 14B on the other axial end side of the core body 14 is smaller than the outer diameter of the outer peripheral surface 25 adjacent to the protrusion 24. The outer member 18 is disposed (i.e., extrapolated) at a position on the one axial end side of the core body 14 on the multiple annular protrusions 28, including the grooves 26 (see FIG. 3).

[0027] The core body 14 is made of metal, for example, a steel member. A rubber or resin hose 60 (see FIG. 7) is connected to the other axial end of the core body 14. The hose 60 is fixed to the core body 14 by using a fastener 62 to make the annular protrusion 28 bite into the inner peripheral surface of the hose 60 (see FIG. 7). In this embodiment, the state in which the hose 60 is connected is not shown.

[0028] (nut) 1, the nut 16 is a fastening member that can be engaged with a tool such as a wrench, and has a hexagonal outer circumferential surface. The nut 16 is made of metal, for example, a steel member.

[0029] A female thread portion 32 is formed on the inner peripheral surface 31 of the nut 16 at a position extending from one axial end (the left side of the drawing in FIG. 1 ) to the axial middle portion. A hook portion 34 is formed on the other axial end (the right side of the drawing in FIG. 1 ) of the nut 16, protruding radially inward from the inner peripheral surface 31. The inner diameter of the hook portion 34 is smaller than the outer diameter of the protruding portion 24 of the core body 14. A step portion 35 is formed between the inner peripheral surface 31 and the hook portion 34. The inner diameter of the hook portion 34 is larger than the outer diameter of the portion of the core body 14 other than the protruding portion 24. The inner diameter of the female thread portion 32 is larger than the outer diameter of the protruding portion 24. The hook portion 34 is integrally formed with the nut 16 by lathe processing or the like, and has sufficient strength to withstand the application of tensile force.

[0030] As shown in Fig. 2, the nut 16 is inserted onto the core body 14 from the end 14B on the other axial end side of the core body 14 (the end 14B opposite the protruding portion 24) as indicated by arrow A. In other words, the core body 14 is inserted into the nut 16 from the end 14B of the core body 14. Then, as shown in Fig. 3, the hooking portion 34 of the nut 16 is hooked onto the protruding portion 24 of the core body 14, so that the nut 16 is placed on the end 14A on one axial end side of the core body 14 (see Fig. 3). The protruding portion 24 of the core body 14 is inserted inside the nut 16.

[0031] (Outer member) As shown in Fig. 1, the outer member 18 is cylindrical. With the nut 16 disposed on one axial end of the core body 14, the outer member 18 is disposed on the outer peripheral side of the nut 16 on the other axial end of the core body 14 (see Fig. 3). The outer member 18 is made of metal, for example, a steel member.

[0032] The outer member 18 includes a grip portion 42 on which a tool such as a wrench can be applied, and a thin-walled portion 44 that is thinner than the grip portion 42. As an example, the grip portion 42 is hexagonal. In the first embodiment, the grip portion 42 is formed in the axial middle portion of the outer member 18, and the thin-walled portion 44 is formed on one axial end side of the outer member 18 (the left side of the paper in FIG. 1 ). In other words, the thin-walled portion 44 is provided on the nut 16 side relative to the grip portion 42. The outer diameter of the thin-walled portion 44 is smaller than the outer diameter of the smallest portion of the grip portion 42. The inner diameter of the inner circumferential surface 41 of the outer member 18 (particularly, the inner diameter of the inner circumferential surface 41 at the grip portion 42 and the thin-walled portion 44) is substantially constant along the axial direction. The inner diameter of the inner circumferential surface 41 of the outer member 18 is larger than the outer diameter of the outer circumferential surface 27 of the core body 14 on the other axial end side relative to the groove portion 26.

[0033] The other axial end of the outer member 18 (the right side of the paper in FIG. 1) is provided with an outer peripheral surface 46 having an outer diameter larger than that of the thin-walled portion 44, and a recess 48 formed in the outer peripheral surface 46. The recess 48 is formed in a position adjacent to the grip portion 42.

[0034] As shown in Figure 3, with the nut 16 positioned on the outer periphery of the core body 14, the end 14B on the other axial end of the core body 14 is inserted into the outer member 18, so that the outer member 18 is positioned adjacent to the nut 16 on the outer periphery of the core body 14.

[0035] (Method of fixing the outer member to the core body) The method of securing the outer member 18 to the core body 14 will now be described.

[0036] As shown in Figures 3 and 4(A), a groove 26 is formed on the outer peripheral surface 25 of the core body 14. With the outer member 18 placed in a position adjacent to the nut 16 on the outer peripheral side of the core body 14, the groove 26 of the core body 14 is provided in alignment with the position of the thin-walled portion 44 of the outer member 18. As a result, the groove 26 is positioned radially inward of the thin-walled portion 44, as shown in Figures 3 and 4(B).

[0037] In this state, as shown in Fig. 4(B), the thin-walled portion 44 of the outer member 18 is tightened (i.e., crimped) from the outside as indicated by arrow B. As a result, as shown in Fig. 4(C), the thin-walled portion 44 is plastically deformed to form a deformed portion 45, which is engaged with the groove portion 26. The engagement of the deformed portion 45 with the groove portion 26 fixes the outer member 18 to the core body 14. At this time, because the thin-walled portion 44 is plastically deformed, a gap may be formed between the deformed portion 45 and the concave corner of the groove portion 26 after the plastic deformation.

[0038] 5(A) and (B) show a crimping device 68 having multiple (e.g., eight) dies 70 arranged on the outer peripheral side of the outer member 18. As shown in FIGS. 5(A) and (B), each die 70 has an arc-shaped curved surface 70A formed on its radially inner side. The curved surfaces 70A of the multiple dies 70 are arranged on a circular imaginary line, and by moving the multiple dies 70 radially inward as indicated by arrow B, the circular imaginary line of the curved surfaces 70A of the multiple dies 70 shrinks. By moving the multiple dies 70 radially inward, the thin-walled portion 44 of the outer member 18 is crimped from the outside. As a result, the deformed portion 45, which is plastically deformed in the thin-walled portion 44, is engaged with the groove portion 26, as shown in FIG. 4(C).

[0039] The deformed portion 45 engages with the groove 26 to fix the outer member 18 to the core body 14, and the hook portion 34 of the nut 16 is restricted between the protruding portion 24 of the core body 14 and the outer member 18 (see FIG. 6). This prevents the nut 16 from falling off the core body 14.

[0040] As shown in FIG. 6, a cylindrical mating member 80 is connected to the nut 16. Specifically, the male thread portion 82 of the mating member 80 is screwed into the female thread portion 32 of the nut 16. This connects the mating member 80 to one axial end of the core body 14 via the nut 16. In this state, the inclined surface of the mating member 80, whose inner diameter gradually increases toward the axial end, contacts the inclined surface of the core body 14, whose outer diameter gradually decreases toward the axial end. As an example, the mating member 80 has a hexagonal grip portion 84 in the axial middle, but the configuration of the mating member 80 can be changed.

[0041] As shown in Fig. 7, a fastener 62 is disposed on the other axial end of the core body 14 at a position spanning the outer member 18 and the core body 14. Fig. 7 does not show the fastener 62 fixed to the outer member 18 and the hose connected. The hose 60 is inserted between the fastener 62 and the core body 14, and the fastener 62 is tightened from the outside to connect the hose 60.

[0042] (Action and effect) Next, the operation and effects of the first embodiment will be described.

[0043] In the connector 12 having the joint structure S10 of the first embodiment, the metal core body 14 has a protruding portion 24 that protrudes radially outward at one axial end. With the protruding portion 24 inserted into the nut 16, the hook portion 34 of the nut 16 is hooked onto the protruding portion 24 (see FIG. 3). The core body 14 has a groove portion 26 that is continuously formed along the circumferential direction on the outer peripheral surface 25 on the other axial end side relative to the protruding portion 24, and a metal outer member 18 is provided on the outer peripheral side of the core body 14 closer to the other axial end side than the nut 16.

[0044] The outer member 18 is composed of a thin-walled portion 44 (see FIG. 4(B)), which is thinner than the gripping portion 42 on which the tool is attached, and includes a deformed portion 45 that is secured to the core body 14 by plastic deformation when externally crimped and engages with the groove 26 (see FIGS. 4(C) and 7). Therefore, the outer member 18 is secured to the core body 14 by engaging the deformed portion 45 of the outer member 18 with the groove 26 of the core body 14, ensuring stable quality compared to when the outer member and the core body are secured by brazing. Furthermore, since the groove 26 is formed in the core body 14 and the thin-walled portion 44, which is thinner than the gripping portion 42, is externally crimped to secure the plastically deformed deformed portion 45 with the groove 26, manufacturing is easy. This ensures a stable supply of ferrules 12.

[0045] Furthermore, in the ferrule 12 having the joint structure S10, the thin-walled portion 44 is located at the axial end of the outer member 18 on the nut 16 side relative to the gripping portion 42, and the core body 14 has a groove 26 aligned with the thin-walled portion 44. Because the thin-walled portion 44 is located at the axial end of the outer member 18 on the nut 16 side relative to the gripping portion 42, it is easy to align the thin-walled portion 44 with the groove 26. Furthermore, because the thin-walled portion 44 is easily plastically deformed when externally crimped, the plastically deformed portion 45 easily engages with the groove 26, facilitating manufacturing. Furthermore, because the ferrule 12 uses a crimping device 68 and multiple dies 70 to externally crimp the thin-walled portion 44 of the outer member 18, manufacturing of the ferrule 12 with consistent quality is possible without relying on manual labor, and mass production is also easy. Furthermore, because manual labor is not required, no specific skills are required, and manufacturing time and costs can be significantly reduced.

[0046] (First Comparative Example) A ferrule 500 of a first comparative example is shown in Figures 15 and 16. Note that the same components as those in the first embodiment described above are given the same reference numerals and their description will be omitted.

[0047] As shown in Fig. 15, the ferrule 500 includes a core body 502, a nut 16, and an outer member 504. The core body 502 has an outer peripheral surface 512 at an axially intermediate portion on the protruding portion 24 side relative to the multiple annular protrusions 28, and the outer peripheral surface 512 has a substantially uniform outer diameter. That is, the outer peripheral surface 512 of the core body 502 does not have a groove portion like the core body 14 of the first embodiment. The outer member 504 also has a hexagonal grip portion 522 that is continuously formed to one axial end portion on the nut 16 side. That is, one axial end portion of the outer member 504 does not have a thin-walled portion like the outer member 18 of the first embodiment.

[0048] As shown in FIG. 16 , the protruding portion 24 of the core body 502 is inserted into the nut 16, and the hooking portion 34 of the nut 16 is hooked onto the protruding portion 24 of the core body 502. In this state, the outer member 504 is positioned adjacent to the nut 16 in the axial direction of the core body 502 and outside the outer peripheral surface 512 of the core body 502. When fastening the outer member 504 to the core body 502, a brazed portion 520 is formed by brazing an end portion 524 of the outer member 504 opposite the axial gripping portion 522 to the outer peripheral surface 512 of the core body 502. This fastens the outer member 504 to the core body 502 via the brazed portion 520. Fastening the outer member 504 to the core body 502 using the brazed portion 520 in this way relies on manual labor and requires a lot of man-hours, making it difficult to stabilize quality and ensure a stable supply of the cap fittings 500.

[0049] In contrast, in the ferrule 12 of the first embodiment, the outer member 18 is fixed to the core body 14 by engaging the deformed portion 45, which is obtained by plastically deforming the thin-walled portion 44 of the outer member 18, with the groove portion 26 of the core body 14. Therefore, compared to when the outer member 504 and the core body 502 are fixed by the brazing portion 520, the ferrule 12 of the first embodiment provides stable quality, is easy to manufacture, and ensures a stable supply of ferrules 12.

[0050] (Second Comparative Example) As a second comparative example, as shown in Fig. 17, a configuration is also possible in which an end 534 of the nut 530 opposite the female thread portion 532 in the axial direction is externally tightened to engage with a groove portion (not shown) in the core body, thereby fixing the nut 530 to the core body. However, in the configuration shown in Fig. 17, in order to deform the end 534 of the nut 530, it is necessary to thin the thickness of the end 534 of the nut 530, and if the diameter is large, the vicinity of the end 534 of the nut 530 may deform when a high-pressure load is applied, which may result in insufficient strength.

[0051] In contrast, in the ferrule 12 of the first embodiment, the thin-walled portion 44 of the outer member 18, which is located on the outer peripheral side of the axially middle portion of the core body 14, is externally crimped, causing the plastically deformed portion 45 to engage with the groove portion 26 of the core body 14, thereby preventing the nut 16 from falling off with the outer member 18. This makes it less likely that problems such as deformation of the nut 16 or the outer member 18 will occur when a high-pressure load is applied. Also, compared to when the nut is deformed, the thickness of the nut 16 can be made thicker to make it less likely to deform, making it possible to obtain a ferrule 12 that can withstand high-pressure conditions even in cases where the nut is large.

[0052] [Second embodiment] Next, a joint structure according to a second embodiment will be described. Note that the same components as those in the first embodiment described above will be assigned the same reference numerals and the description thereof will be omitted.

[0053] 8 and 9, a fitting 102 equipped with a joint structure S100 according to the second embodiment includes a core body 104, a nut 16, and an outer member 106. As in the first embodiment, the core body 104 is made of metal, and the outer member 106 is also made of metal.

[0054] An outer peripheral surface 112 having an outer diameter smaller than that of the outer peripheral surface 25 adjacent to the protruding portion 24 is formed in the axial middle portion of the core body 104 (i.e., the other end side in the axial direction relative to the protruding portion 24). A groove portion 114 is formed in the outer peripheral surface 112. The groove portion 114 is formed continuously along the circumferential direction.

[0055] The outer member 106 has a gripping portion 122 on one axial end side on which a tool can be hung. The gripping portion 122 is hexagonal and is formed continuously to an end portion 106A on one axial end side of the outer member 106. The outer member 106 has a thin-walled portion 124 near an end portion 106B on the other axial end side, the thin-walled portion 124 being thinner than the gripping portion 122. The thin-walled portion 124 is provided on the opposite side of the gripping portion 122 from the nut 16 (see FIG. 9). The thin-walled portion 124 has a concave shape recessed from an outer surface 126 of the end portion 106B on the other axial end side.

[0056] As shown in Figures 9 and 10(A), a groove 114 is formed on the outer peripheral surface 112 of the core body 104. With the outer member 106 placed in a position adjacent to the nut 16 on the outer peripheral side of the core body 104, the groove 114 of the core body 104 is provided in alignment with the position of the thin-walled portion 124 of the outer member 106. As a result, the groove 114 is positioned radially inward of the thin-walled portion 124, as shown in Figures 9 and 10(B).

[0057] In this state, as shown in Figure 10(B), by crimping the thin-walled portion 124 of the outer member 106 from the outside as indicated by arrow B, the thin-walled portion 124 is plastically deformed to form a deformed portion 125, which is engaged with the groove portion 114 as shown in Figure 10(C). The engagement of the deformed portion 125 with the groove portion 114 fixes the outer member 106 to the core body 104. At this time, because the thin-walled portion 114 is plastically deformed, a gap may be formed between the deformed portion 125 and the concave corner of the groove portion 114 after the plastic deformation. The other configurations of the ferrule 102 equipped with the joint structure S100 are the same as those of the ferrule 12 of the first embodiment.

[0058] The ferrule 102 having the joint structure S100 can obtain the following actions and effects in addition to the actions and effects of the same configuration as the ferrule 12 of the first embodiment.

[0059] The thin-walled portion 124 of the outer member 106 is provided on the opposite side of the gripping portion 122 from the nut 16, and has a concave shape recessed from an outer surface 126. The core body 104 has a groove 114 formed in accordance with the position of the thin-walled portion 124. In the ferrule 102, the thin-walled portion 124 is crimped from the outside, causing a deformed portion 125 that is plastically deformed to engage with the groove 114. At this time, the thin-walled portion 124 recessed from the outer surface 126 is prone to plastic deformation, making it easy for the deformed portion 125 to engage with the groove 114, facilitating manufacturing.

[0060] [Third embodiment] Next, a joint structure according to a third embodiment will be described. Note that the same components as those in the first and second embodiments described above will be given the same reference numerals and descriptions thereof will be omitted.

[0061] 11 and 12(A), a fitting 152 having a joint structure S150 according to the third embodiment includes a core body 154, a nut 16, and an outer member 156. As in the first embodiment, the core body 154 is made of metal, and the outer member 156 is also made of metal.

[0062] A groove 162 is formed in the outer peripheral surface 112 of the axially intermediate portion of the core body 154 (i.e., the other axial end side relative to the protruding portion 24). The groove 162 is formed continuously along the circumferential direction. As shown in FIG. 12(B), the groove 162 includes a tapered portion 162A whose outer diameter gradually decreases from the outer peripheral surface 112 on the protruding portion 24 side, and a vertical wall portion 162B that protrudes radially outward from the end of the tapered portion 162A opposite the protruding portion 24. In other words, the groove 162 is shaped like a notch that includes the tapered portion 162A and the vertical wall portion 162B.

[0063] The outer member 156 has a thin-walled portion 174 at the end 106B on the other axial end side that is thinner than the gripping portion 122. The thin-walled portion 174 is provided on the opposite side of the nut 16 across the gripping portion 122 (see FIG. 12(A)). The thin-walled portion 174 has an outer surface 174B formed at the end 106B on the other axial end side, and a recessed portion 174A recessed from the outer surface 174B. An angular portion 174C is formed at the end of the inner surface of the thin-walled portion 174 by plastic deformation, and is engageable with the tapered portion 162A and the vertical wall portion 162B.

[0064] 12(A) and (B), with the outer member 156 disposed adjacent to the nut 16 on the outer peripheral side of the core body 154, a groove 162 is provided in the core body 154 in accordance with the position of the thin-walled portion 174 of the outer member 156. As a result, the groove 162 is positioned radially inward of the thin-walled portion 174.

[0065] In this state, as shown in FIG. 12(B), by crimping the thin-walled portion 174 of the outer member 156 from the outside, the thin-walled portion 174 is plastically deformed to form a deformed portion 175, which is engaged with the groove portion 162. At this time, the corner portion 174C is engaged with the tapered portion 162A and the vertical wall portion 162B due to the plastic deformation. This fixes the outer member 156 to the core body 154. At this time, because the thin-walled portion 174 is plastically deformed, a gap may be formed between the deformed portion 175 and the concave corner of the groove portion 162 after the plastic deformation. The other configurations of the ferrule 152 equipped with the joint structure S150 are the same as those of the ferrule 12 of the first embodiment.

[0066] The ferrule 152 having the joint structure S150 can obtain the following actions and effects in addition to the actions and effects of the same configuration as the ferrule 12 of the first embodiment.

[0067] Groove 162 includes tapered portion 162A and vertical wall portion 162B, and corners 174C are formed on the inner surface of thin portion 174. These corners 174C are engageable with tapered portion 162A and vertical wall portion 162B through plastic deformation. By crimping thin portion 174 from the outside, corners 174C are engaged with tapered portion 162A and vertical wall portion 162B through plastic deformation. This makes it easier for deformed portion 175 to engage with groove 162.

[0068] [Fourth embodiment] Next, a joint structure according to a fourth embodiment will be described. Note that the same components as those in the first to third embodiments described above are given the same reference numerals and the description thereof will be omitted.

[0069] 13 and 14(A), a fitting 202 equipped with a joint structure S200 according to the fourth embodiment includes a core body 204, a nut 16, and an outer member 206. As in the first embodiment, the core body 204 is made of metal, and the outer member 206 is also made of metal.

[0070] A groove 212 is formed on the outer peripheral surface 112 of the axially intermediate portion of the core body 154 (i.e., the other end side of the axial direction relative to the protruding portion 24). The groove 212 is continuously formed along the circumferential direction. As shown in FIG. 14(B), the groove 212 is formed by alternating two tapered portions 212A whose outer diameter gradually decreases and two vertical wall portions 212B that protrude radially outward from the end of the tapered portion 212A opposite the protruding portion 24. When the tapered portion 212 and the vertical hanging portion 212B are considered as one groove, the groove 212 of this embodiment has two grooves. Of the two tapered portions 212A and vertical wall portions 212B formed alternately in the groove 212, the tapered portion 212A and the vertical wall portion 212B in the axially intermediate portion form an acute-angled convex portion 213.

[0071] The outer member 206 has a thin-walled portion 224 at the end 106B on the other axial end side, which is thinner than the gripping portion 122. The thin-walled portion 224 is provided on the opposite side of the nut 16 across the gripping portion 122 (see FIG. 14(A)). The thin-walled portion 224 has an outer surface 174B formed at the end 106B on the other axial end side, and a recessed portion 174A recessed from the outer surface 174B. The inner surface of the thin-walled portion 224 is formed with a recessed portion 224A that can be plastically deformed to engage with an acute-angled protrusion 213 formed by a tapered portion 212A in the axial middle and the vertical wall portion 212B. The recessed portion 224A is an acute-angled recess in cross-sectional view. Furthermore, a corner 224B that can be engaged with the tapered portion 212A and the vertical wall portion 212B on the other axial end side by plastic deformation is formed at the end of the inner surface of the thin-walled portion 224. The corner 224B is an acute-angled corner in cross-sectional view.

[0072] 14(A) and (B), with the outer member 206 disposed adjacent to the nut 16 on the outer peripheral side of the core body 204, the groove 212 of the core body 204 is provided in alignment with the position of the thin-walled portion 224 of the outer member 206. As a result, the groove 212 is positioned radially inward of the thin-walled portion 224.

[0073] In this state, as shown in FIG. 14(B), the thin-walled portion 224 of the outer member 206 is externally crimped, whereby the thin-walled portion 224 is plastically deformed to form a deformed portion 225, which is engaged with the groove 212, as shown in FIG. 14(C). At this time, the recess 224A is engaged with the acute-angled convex portion 213 formed by the tapered portion 212A and the vertical wall portion 212B, and the corner 224B is engaged with the tapered portion 212A and the vertical wall portion 212B at the other axial end, due to plastic deformation. This secures the outer member 206 to the core body 204. Because the thin-walled portion 224 is plastically deformed, a gap may form between the convex corner of the deformed portion 225 and the concave corner of the groove 212 after plastic deformation. The other configurations of the ferrule 202 equipped with the joint structure S200 are the same as those of the ferrule 152 of the third embodiment.

[0074] The ferrule 202 having the joint structure S200 can obtain the following actions and effects in addition to the actions and effects of the same configuration as the ferrule 152 of the third embodiment.

[0075] A recess 224A is provided on the inner surface of the thin-walled portion 224, and by crimping the thin-walled portion 224 from the outside, the recess 224A easily engages with the acute-angled protrusion 213 formed by the vertical wall portion 212B and the tapered portion 212A at the axial middle portion due to plastic deformation. Furthermore, a corner 224B is provided on the end of the inner surface of the thin-walled portion 224, and the corner 224B easily engages with the tapered portion 212A and the vertical wall portion 212B at the other axial end side due to plastic deformation. This allows the outer member 206 to be more reliably fixed to the core body 204.

[0076] The thin-walled portion of the outer member and the groove portion of the core body are not limited to the configurations described in the first to fourth embodiments. The shapes of the thin-walled portion of the outer member and the groove portion of the core body can be changed without departing from the scope of the present invention. Furthermore, the shapes of other parts of the core body, outer member, and nut in the first to fourth embodiments can be changed. For example, the shape of the end portion 14A of the core body 14, 104, 154, 204 can be changed.

[0077] Furthermore, although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that the present invention is not limited to such embodiments, and that various other embodiments are possible within the scope of the present invention. [Explanation of symbols]

[0078] S10 Joint Structure 14 Core body 16 Nut (nut material) 18 Outer member 24 Overhang 25 Outer surface 26 Groove 31 Inner surface 32 Female thread 34 Hook 42 Gripping part 44 Thin-walled section 45 Deformed part 80 Counterpart S100 joint structure 104 Core body 106 Outer member 106B End 112 Outer surface 114 Groove 122 Gripping part 124 Thin-walled section 125 Deformed part S150 joint structure 154 Core body 156 Outer member 162 Groove 162A Tapered section 162B Vertical wall section 174 Thin-walled section 174C Corner 175 Deformed part S200 joint structure 204 Core body 206 Outer member 212 Groove 212A Tapered section 212B Vertical wall section 213 Convex 224 Thin-walled section 224A Recess 224B Corner 225 Deformed part

Claims

1. a metal core body including a protruding portion protruding radially outward at one end in the axial direction, and a groove portion continuously formed along a circumferential direction on an outer peripheral surface at the other end in the axial direction relative to the protruding portion; a nut member having a hook portion whose inner diameter is smaller than that of the protruding portion and a female screw portion to which a mating member is connected, the protruding portion being inserted; a cylindrical metal outer member including a gripping portion provided on the outer periphery of the core body on the other end side in the axial direction than the nut member and on which a tool can be hung, and a deformation portion consisting of a thin-walled portion thinner than the gripping portion, which is engaged with the groove portion by plastic deformation when crimped from the outside and fixed to the core body; A joint structure having:

2. the thin-walled portion is provided at an axial end of the outer member on the nut member side with respect to the grip portion, The joint structure according to claim 1 , wherein the groove is provided in the core body in accordance with the position of the thin-walled portion.

3. The thin-walled portion is provided on the opposite side of the gripping portion from the nut member, and has a shape recessed from an outer surface, The joint structure according to claim 1 , wherein the groove is provided in the core body in accordance with the position of the thin-walled portion.

4. the groove portion includes a tapered portion whose outer diameter gradually decreases from the outer peripheral surface on the side of the protruding portion, and a vertical wall portion that protrudes radially outward from an end of the tapered portion on the opposite side to the protruding portion, 4. The joint structure according to claim 3, wherein an inner surface of the thin-walled portion is formed with a corner portion that can be engaged with the tapered portion and the vertical wall portion by plastic deformation.

5. The groove portion has at least two tapered portions and two vertical wall portions alternately formed along the axial direction, 5. The joint structure according to claim 4, wherein an inner surface of the thin-walled portion is provided with a recess that can be engaged by plastic deformation with an acute-angled protrusion formed by the vertical wall portions and the tapered portions of the at least two alternately formed intermediate portions in the axial direction.

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