Pipe joint

Abstract

To provide a pipe joint capable of reducing external force required for securing desired pipe holding force.SOLUTION: A pipe joint includes a cylindrical body, a first annular member provided in an internal passage of the body, and a second annular member provided between the first annular member in the internal passage and one end opening of the body into which an external pipe is inserted, and into which the external pipe can be inserted. The main body inner peripheral surface has a facing surface located between the second annular member and the one end opening. The second annular member includes a first contact portion that is in contact with the outer pipe and a second contact portion that can be in line contact or point contact with the facing surface. The first annular member is configured to push the second annular member when being pushed toward the one end opening. The second annular member is configured such that, when the second annular member is pressed by the first annular member in a state in which the first contact portion is in contact with the outer pipe, the first contact portion bites into the outer pipe and the second contact portion is deformed so as to move radially outward while being in contact with the facing surface.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a pipe fitting. [Background technology]

[0002] Pipe fittings are known that are used to connect pipes that form a flow path for a refrigerant or the like in a refrigeration system, etc. Some pipe fittings have a function of holding the inserted pipe by having a ferrule provided in the pipe fitting bite into the inserted pipe.

[0003] For example, Patent Document 1 discloses a bite-type pipe joint that includes a joint body into which a pipe is inserted, a nut that is fastened to the joint body, and a ferrule that is interposed between the joint body and the nut. In this pipe joint, first, the pipe is inserted into the joint body. Next, the ferrule is fitted onto the pipe. Next, the nut is tightened. As a result, the ferrule is pushed by the nut and moves. During this movement, the ferrule deforms so as to bite into the outer peripheral surface of the pipe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6012823 Summary of the Invention [Problem to be solved by the invention]

[0005] In bite-type pipe fittings such as those described above, a certain amount of pipe deformation is required to ensure the desired pipe retention force. This increases the torque required to tighten the nut. In other words, there is a problem in that a large external force is required to ensure the desired pipe retention force. The pipe fitting disclosed in Patent Document 1 attempts to solve this problem by setting the ratio of the radial gap between the fitting body and the pipe to the radial thickness of the tip of the ferrule within a predetermined range.

[0006] However, in the pipe fitting disclosed in Patent Document 1, the outer diameter of the pipe is limited to a predetermined range, so there is room for improvement in the pipe fitting so that the external force required to ensure a desired pipe retention force can be reduced regardless of the outer diameter of the pipe.

[0007] Therefore, an object of the present disclosure is to solve the above-mentioned problems and to provide a pipe fitting that can reduce the external force required to ensure a desired pipe holding force. [Means for solving the problem]

[0008] A pipe fitting according to one aspect of the present disclosure includes: A cylindrical body, a first annular member provided in the internal passage of the body so as to be movable along the axial direction of the body along the internal passage; a second annular member, which is provided in the internal passage between the first annular member and one end opening of the body into which an external pipe is inserted, and which is movable along the axial direction and into which the external pipe can be inserted; an inner circumferential surface of the main body that constitutes the internal passage has an opposing surface that is located between the second annular member and the one-end opening and that faces the second annular member in the axial direction; The second annular member is a first contact portion provided on an inner peripheral surface of the second annular member and in contact with an outer peripheral surface of the outer pipe inserted into the second annular member; at least one second contact portion that faces the opposing surface in the axial direction and is capable of line contact or point contact with the opposing surface; the first annular member is configured to move along the axial direction when pushed toward the one-end opening to push the second annular member toward the one-end opening; The second annular member is configured such that when the second contact portion is in contact with the opposing surface and the first annular member is pushed toward the one end opening, the first contact portion bites into the outer peripheral surface of the external tube and the second contact portion deforms so as to move radially outward from the main body while contacting the opposing surface. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a pipe fitting that can reduce the external force required to ensure a desired pipe holding force. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a plan view of a pipe fitting and an instrument connection according to one embodiment of the present disclosure. [Figure 2] FIG. 1 is an exploded perspective view of a pipe fitting and an instrument interface according to one embodiment of the present disclosure. [Figure 3] FIG. 2 is a cross-sectional view showing the AA section of FIG. [Figure 4] 4 is a cross-sectional view of the device connector in the state of FIG. 3 when it is tightened and further inserted into the opening at one end. [Figure 5] FIG. 4 is an enlarged view of the dashed dotted line portion of FIG. 3. [Figure 6] FIG. 5 is an enlarged view of the dashed dotted line portion of FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0011] An example of the present disclosure will now be described with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses. The drawings are schematic, and the ratios of dimensions and the like do not necessarily correspond to reality. In the following description, terms indicating specific directions or positions (e.g., terms including "upper," "lower," "right," "left," "front," and "rear") may be used as necessary. The use of the terms indicating specific directions or positions is intended to facilitate understanding of the present disclosure with reference to the drawings, and the meanings of these terms do not limit the technical scope of the present disclosure.

[0012] <Embodiment> Fig. 1 is a plan view of a pipe fitting and an equipment connection portion according to an embodiment of the present disclosure, Fig. 2 is an exploded perspective view of the pipe fitting and the equipment connection portion according to an embodiment of the present disclosure, and Fig. 3 is a cross-sectional view showing the AA cross section of Fig. 1.

[0013] 1 to 3 is used, for example, to connect pipes that form a refrigerant flow path in devices such as refrigeration equipment and air conditioners. Note that the use of the pipe fitting 10 is not limited to the above-mentioned embodiments, and it may be used in any way as long as it is used to connect pipes.

[0014] As shown in Fig. 1, the pipe fitting 10 includes a cylindrical main body 20. The shape of the main body 20 is not limited to the shapes shown in Figs. 1 to 3, as long as it has an internal passage 20A that penetrates the main body 20 along the axial direction 101.

[0015] As shown in Fig. 2, the pipe fitting 10 includes a first annular member 30, a second annular member 40, a lock ring 50, and O-rings 61, 62, and 63. As shown in Fig. 3, the first annular member 30, the second annular member 40, the lock ring 50, and the O-rings 61, 62, and 63 are provided in an internal passage 20A of the main body 20. The internal passage 20A extends along the axial direction 101 of the cylindrical main body 20, and is open at one end opening 20Aa and the other end opening 20Ab.

[0016] 1 and 3, the device connection part 70 can be inserted into the internal passage 20A of the main body 20 through the other end opening 20Ab. The device connection part 70 is a part that connects to the outside and is provided in a device such as a refrigeration device or an air conditioner. Note that in each drawing, only the device connection part 70 of the device is shown, and parts of the device other than the device connection part 70 are not shown.

[0017] 2 and 3, in this embodiment, a screw thread 70B is provided on the outer peripheral surface 70A of the device connection part 70. A screw groove 20Bh is provided on the inner peripheral surface 20B of the main body 20 near the other end opening 20Ab. The main body inner peripheral surface 20B is a surface that constitutes the internal passage 20A. The screw thread 70B is fitted into the screw groove 20Bh and moves along the screw groove 20Bh, thereby tightening the device connection part 70 to the main body 20.

[0018] FIG. 4 is a cross-sectional view of the device connector in the state shown in FIG. 3, in which the device connector is tightened and further inserted into the one-end opening.

[0019] 4, the external pipe 80 can be inserted into the internal passage 20A of the main body 20 through the one end opening 20Aa. The external pipe 80 is, for example, a copper pipe through which a refrigerant or the like flows. The external pipe 80 is inserted into the internal passage 20A through the one end opening 20Aa, and the device connection part 70 is inserted into the internal passage 20A through the other end opening 20Ab, whereby the device connection part 70 and the external pipe 80 are connected via the pipe fitting 10.

[0020] The device connection part 70 has an internal passage 70D, and the external pipe 80 has an internal passage 80B. When the device connection part 70 and the external pipe 80 are connected via the pipe fitting 10, the internal passage 70D of the device connection part 70 and the internal passage 80B of the external pipe 80 communicate with each other via the internal passage 20A of the main body 20.

[0021] As shown in Fig. 2, the first annular member 30 is annular when viewed along the axial direction 101. In other words, the first annular member 30 has a through hole that penetrates the first annular member 30 along the axial direction 101. As shown in Fig. 4, in this embodiment, an outer pipe 80 can be inserted into the first annular member 30. However, the outer pipe 80 does not have to be inserted into the first annular member 30. In other words, the pipe fitting 10 may be configured so that the outer pipe 80 can be inserted up to the second annular member 40, which will be described later, but is not inserted into the first annular member 30.

[0022] The first annular member 30 is provided so as to be movable in the internal passage 20A of the main body 20 along the axial direction 101.

[0023] FIG. 5 is an enlarged view of the dashed line portion of FIG.

[0024] As shown in FIG. 5, the first annular member 30 has an inner circumferential surface 30A, an outer circumferential surface 30B, a one-side contact surface 30C, a first other-side contact surface 30D, and a second other-side contact surface 30E.

[0025] The inner circumferential surface 30A is a surface that forms a through hole that penetrates the first annular member 30 in the axial direction 101. The inner circumferential surface 30A has a protrusion 30Aa that protrudes inward in the radial direction 102. In this embodiment, the protrusion 30Aa is provided at the end of the inner circumferential surface 30A on the other end opening 20Ab side in the axial direction 101. The radial direction 102 is a direction that extends radially from an axis 103 of the main body 20. The axis 103 of the main body 20 is an imaginary line that is located at the center of the internal passage 20A when viewed along the axial direction 101 and that extends parallel to the axial direction 101.

[0026] The protrusion 30Aa has an inner contact surface 30Ab facing the one end opening 20Aa in the axial direction 101. The inner contact surface 30Ab comes into contact with the insertion tip of the outer tube 80 inserted into the first annular member 30. This restricts further insertion of the outer tube 80.

[0027] The outer peripheral surface 30B faces the main body inner peripheral surface 20B in the radial direction 102. The outer peripheral surface 30B has a protrusion 30Ba that protrudes outward from the outer peripheral surface 30B in the radial direction 102. Meanwhile, the main body 20 has a recess 20Bb on the main body inner peripheral surface 20B at a position facing the protrusion 30Ba in the radial direction 102. When the first annular member 30 moves along the axial direction 101 toward the other end opening 20Ab, the protrusion 30Ba comes into contact with a restricting surface 20Bc that faces the one end opening 20Aa and is one of the surfaces that constitute the recess 20Bb. The restricting surface 20Bc is located between the protrusion 30Ba and the other end opening 20Ab of the main body 20. When the protrusion 30Ba comes into contact with the restricting surface 20Bc, further movement of the first annular member 30 toward the other end opening 20Ab is restricted. As a result, the first annular member 30 is restricted from coming out of the internal passage 20A through the other end opening 20Ab.

[0028] The one-side contact surface 30C is a surface facing the other-end opening 20Ab in the axial direction 101. In this embodiment, the one-side contact surface 30C is inclined with respect to the axial direction 101 so as to move inward in the radial direction 102 as it approaches the one-end opening 20Aa in the axial direction 101, but is not limited to this configuration.

[0029] During the process of inserting the device connection part 70 into the main body 20 (in this embodiment, the device connection part 70 is fastened to the main body 20), a contact surface 70C located at the insertion tip of the device connection part 70 comes into contact with one side contact surface 30C of the first annular member 30. Note that in this embodiment, the contact surface 70C is inclined with respect to the axial direction 101 so as to move inward in the radial direction 102 as it moves toward the one end opening 20Aa in the axial direction 101, but the configuration is not limited to this.

[0030] The first other-side contact surface 30D and the second other-side contact surface 30E are surfaces that face the one-end opening 20Aa in the axial direction 101 and face the second annular member 40. In the present embodiment, the first other-side contact surface 30D is inclined with respect to the axial direction 101 so as to move outward in the radial direction 102 as it approaches the one-end opening 20Aa in the axial direction 101, but this configuration is not limited to this. The second other-side contact surface 30E is located closer to the one-end opening 20Aa in the axial direction 101 than the first other-side contact surface 30D, and is located more outward in the radial direction 102 than the first other-side contact surface 30D.

[0031] 2, the second annular member 40 is annular when viewed along the axial direction 101. That is, the second annular member 40 has a through-hole that penetrates the second annular member 40 in the axial direction 101. As shown in FIG. 4, in this embodiment, an outer pipe 80 can be inserted into the first annular member 30.

[0032] 3, the second annular member 40 is provided between the first annular member 30 and the one-end opening 20Aa in the internal passage 20A. The second annular member 40 is provided so as to be movable in the internal passage 20A of the main body 20 along the axial direction 101.

[0033] Movement of the second annular member 40 toward the other end opening 20Ab is restricted by the first annular member 30 and the device connection portion 70.

[0034] Movement of the second annular member 40 toward the one-end opening 20Aa is restricted by an opposing surface 20Bg provided on the main body inner circumferential surface 20B. The opposing surface 20Bg is located between the second annular member 40 and the one-end opening 20Aa in the axial direction 101. The opposing surface 20Bg faces the second annular member 40 in the axial direction 101.

[0035] As shown in FIG. 5, the second annular member 40 has an inner circumferential surface 40A, an outer circumferential surface 40B, a support surface 40C, a first contact portion 41, and a second contact portion .

[0036] The inner circumferential surface 40A is a surface that constitutes the through hole of the second annular member 40. In the present embodiment, the inner circumferential surface 40A has an inclined surface 40Aa at an end portion on the one-end opening 20Aa side in the axial direction 101. The inclined surface 40Aa is inclined with respect to the axial direction 101 so as to extend outward in the radial direction 102 toward the one-end opening 20Aa in the axial direction 101. Within the through hole of the second annular member 40, claw portions 52 of a lock ring 50, which will be described later, fit into a space surrounded by the inclined surface 40Aa.

[0037] The outer peripheral surface 40B faces the main body inner peripheral surface 20B in the radial direction 102. The outer peripheral surface 40B has a first surface 40Ba and a second surface 40Bb.

[0038] The first surface 40Ba and the second surface 40Bb are surfaces that face the other-end opening 20Ab in the axial direction 101 and face the first annular member 30. In detail, the first surface 40Ba faces the first other-side contact surface 30D of the first annular member 30, and the second surface 40Bb faces the second other-side contact surface 30E of the first annular member 30 in the axial direction 101.

[0039] In the present embodiment, the first surface 40Ba is inclined with respect to the axial direction 101 so as to extend outward in the radial direction 102 toward the one-end opening 20Aa in the axial direction 101, but this configuration is not limited to this. The second surface 40Bb is located closer to the one-end opening 20Aa in the axial direction 101 than the first surface 40Ba and is located more outward in the radial direction 102 than the first surface 40Ba. The second surface 40Bb extends along the radial direction 102 or extends at a steeper incline with respect to the axial direction 101 than the first surface 40Ba. In the present embodiment, the second surface 40Bb expands along the radial direction 102. That is, in the present embodiment, the second surface 40Bb is a surface perpendicular to the axial direction 101. The second surface 40Bb is not limited to a configuration in which it expands along the radial direction 102. For example, the second surface 40Bb may, like the first surface 40Ba, extend outward in the radial direction 102 as it approaches the one end opening 20Aa in the axial direction 101, provided that it is inclined more steeply with respect to the axial direction 101 than the first surface 40Ba.

[0040] The thickness of the second annular member 40 in the radial direction 102 at a portion where the first surface 40Ba is provided in the axial direction 101 is thinner than the thickness of the first annular member 30 in the radial direction 102 at a portion where the first other-side contact surface 30D is provided in the axial direction 101. In other words, the thickness of the first annular member 30 in the radial direction 102 at a portion where the first other-side contact surface 30D is provided in the axial direction 101 is thicker than the thickness of the second annular member 40 in the radial direction 102 at a portion where the first surface 40Ba is provided in the axial direction 101. In addition, there is a gap between the outer peripheral surface 30B of the first annular member 30 and the main body inner peripheral surface 20B. This makes it difficult for the first annular member 30 to deviate outward in the radial direction 102, reducing the possibility of the first annular member 30 coming into contact with the main body inner peripheral surface 20B. As a result, it is possible to prevent the external force required for the first annular member 30 to press the second annular member 40 from increasing due to the first annular member 30 coming into contact with the main body inner circumferential surface 20B.

[0041] The main body inner circumferential surface 20B has a recess 20Ba at a position facing the outer circumferential surface 40B in the radial direction 102. The recess 20Ba is provided around the entire circumference of the main body inner circumferential surface 20B. Due to the provision of the recess 20Ba, the minimum gap G2 in the radial direction 102 between the outer circumferential surface 40B of the second annular member 40 and the main body inner circumferential surface 20B is larger than the minimum gap G1 in the radial direction 102 between the outer circumferential surface 30B of the first annular member 30 and the main body inner circumferential surface 20B.

[0042] The support surface 40C faces the one end opening 20Aa in the axial direction 101. The support surface 40C is capable of supporting an outer edge portion 51 of the lock ring 50, which will be described later.

[0043] The first contact portion 41 is provided on the inner circumferential surface 40A of the second annular member 40. In this embodiment, the first contact portion 41 is provided on the inner circumferential surface 40A on the back side of the first surface 40Ba. The first contact portion 41 is provided at an end portion of the inner circumferential surface 40A on the other end opening 20Ab side in the axial direction 101. The first contact portion 41 is provided around the entire circumference of the inner circumferential surface 40A around the axis 103. The first contact portion 41 protrudes inward from the inner circumferential surface 40A in the radial direction 102. The first contact portion 41 contacts the outer circumferential surface 80A of the outer tube 80 inserted into the second annular member 40 (see FIG. 6). The contact portion of the first contact portion 41 with the outer circumferential surface 80A of the outer tube 80 is a curved surface, but it does not have to be a curved surface.

[0044] The position where the first contact portion 41 is provided is not limited to the back side of the first surface 40Ba, and is not limited to the end portion of the inner circumferential surface 40A on the other end opening 20Ab side in the axial direction 101. The first contact portion 41 may be provided on only a portion of the inner circumferential surface 40A in the circumferential direction. The first contact portion 41 does not have to protrude inward from the inner circumferential surface 40A in the radial direction 102. In this case, for example, the entire surface of the inner circumferential surface 40A can be the first contact portion 41.

[0045] The second contact portion 42 faces the opposing surface 20Bg of the main body 20 in the axial direction 101. In this embodiment, the second contact portion 42 is provided on the support surface 40C. The second contact portion 42 is provided around the entire circumference of the support surface 40C around the axis 103. The second contact portion 42 is located outward from the first surface 40Ba (in other words, the portion of the second annular member 40 that contacts the first other-side contact surface 30D of the first annular member 30) in the radial direction 102. The second contact portion 42 protrudes from the support surface 40C toward the opposing surface 20Bg. The second contact portion 42 can come into contact with the opposing surface 20Bg. The contact portion of the second contact portion 42 with the opposing surface 20Bg is a curved surface. This allows the second contact portion 42 to be in line contact with the opposing surface 20Bg. In particular, the contact portion between the second contact portion 42 and the opposing surface 20Bg is an annular line.

[0046] The position where the second contact portion 42 is provided is not limited to the support surface 40C.

[0047] Furthermore, the second contact portion 42 may be provided only partially around the axis 103 on the support surface 40C. For example, multiple second contact portions 42 may be provided at intervals around the axis 103 on the support surface 40C, and the contact portion of each second contact portion 42 with the opposing surface 20Bg may be a curved surface (e.g., a spherical surface). In this case, each second contact portion 42 is capable of point contact with the opposing surface 20Bg. In other words, it is sufficient for the second annular member 40 to be provided with at least one second contact portion 42. As described above, the second contact portion 42 is capable of line contact or point contact with the opposing surface 20Bg.

[0048] 5, the second annular member 40 may have an inclined surface 40Ab extending from the second contact portion 42, instead of the support surface 40C and the inclined surface 40Aa. In this case, the end of the second annular member 40 on the one-end opening 20Aa side corresponds to the second contact portion 42, and it can be said that the second contact portion 42 does not protrude from another surface such as the support surface 40C.

[0049] Furthermore, the portion of the second contact portion 42 that comes into contact with the opposing surface 20Bg does not have to be a curved surface. For example, the tip of the second contact portion 42 may be bent.

[0050] The lock ring 50 has an outer edge portion 51 that is annular when viewed along the axial direction 101, and a plurality of claw portions 52 that protrude from the outer edge portion 51 toward the other end opening 20Ab.

[0051] The outer edge portion 51 is supported by the support surface 40C of the second annular member 40. The outer edge portion 51 is surrounded by the second contact portion 42 of the second annular member 40. The multiple claw portions 52 are located in the space surrounded by the inclined surface 40Aa in the through hole of the second annular member 40. As described above, in this embodiment, the entire lock ring 50 is located inside the second annular member 40. However, only a portion of the lock ring 50 may be located inside the second annular member 40. For example, the multiple claw portions 52 may be located inside the second annular member 40, and the outer edge portion 51 may be located outside the second annular member 40.

[0052] The outer edge portion 51 allows the external tube 80 to be inserted along the axial direction 101. The multiple claw portions 52 protrude inward in the radial direction 102 as they move in the axial direction 101 toward the other end opening 20Ab. In the process of inserting the external tube 80 into the lock ring 50, the tips of the multiple claw portions 52 come into contact with the external tube 80 and are pushed outward in the radial direction 102 by the external tube 80. In this way, the multiple claw portions 52 restrict the inserted external tube 80 from moving toward the one end opening 20Aa.

[0053] 3, O-rings 61, 62, and 63 are provided in the internal passage 20A of the main body 20. The O-rings 61, 62, and 63 are fitted into grooves 20Bd, 20Be, and 20Bf, respectively, provided in the inner circumferential surface 20B of the main body 20. The O-rings 61, 62, and 63 are made of an elastic and insulating material, such as silicone or rubber.

[0054] The O-ring 61 is provided in the internal passage 20A between the first annular member 30 and the other end opening 20Ab. The inner diameter of the O-ring 61 is slightly smaller than the outer diameter of the device connection part 70. As a result, the O-ring 61 seals the gap between the device connection part 70 inserted into the internal passage 20A and the main body inner circumferential surface 20B, restricting the flow of liquid through the gap.

[0055] The O-rings 62 and 63 are provided between the opposing surface 20Bg of the internal passage 20A and the one-end opening 20Aa. The inner diameters of the O-rings 62 and 63 are slightly smaller than the outer diameter of the external pipe 80. As a result, the gap between the external pipe 80 inserted into the internal passage 20A and the main body inner circumferential surface 20B is sealed by the O-rings 62 and 63, restricting the flow of liquid through the gap.

[0056] The number of O-rings is not limited to three.

[0057] The operation of connecting the device connection portion 70 and the external pipe 80 via the pipe joint 10 will be described below.

[0058] 3, the device connection part 70 is inserted into the internal passage 20A from the other end opening 20Ab of the main body 20 toward the one end opening 20Aa. Specifically, one of the device connection part 70 and the main body 20 is rotated about the axial direction 101 relative to the other so that the thread 70B of the device connection part 70 engages with the thread groove 20Bh of the main body 20, thereby fastening the device connection part 70 to the main body 20.

[0059] 3 and 5, during the process of inserting the device connection portion 70 into the main body 20, the contact surface 70C of the device connection portion 70 presses the one-side contact surface 30C of the first annular member 30 along the axial direction 101 toward the one-end opening 20Aa. That is, the device connection portion 70 presses the first annular member 30. The first other-side contact surface 30D of the first annular member 30 pressed by the device connection portion 70 presses the first surface 40Ba of the second annular member 40 along the axial direction 101 toward the one-end opening 20Aa. That is, when pressed toward the one-end opening 20Aa, the first annular member 30 moves along the axial direction 101 and presses the second annular member 40 toward the opposing surface 20Bg. When the second contact portion 42 of the second annular member 40 contacts the opposing surface 20Bg of the main body 20, movement of the second annular member 40 toward the one-end opening 20Aa is restricted by the opposing surface 20Bg. As a result, the first annular member 30 and the second annular member 40 are positioned in the axial direction 101. Figure 3 shows a state in which the first annular member 30 and the second annular member 40 are positioned in the axial direction 101.

[0060] Next, the outer pipe 80 is inserted into the internal passage 20A from the one end opening 20Aa of the main body 20. The outer pipe 80 can be inserted until it contacts the inner contact surface 30Ab of the first annular member 30.

[0061] During the process of inserting the external tube 80 into the main body 20, the tips of the multiple claws 52 of the lock ring 50 come into contact with the external tube 80 and are pushed outward in the radial direction 102 by the external tube 80. As a result, the multiple claws 52 restrict movement of the inserted external tube 80 toward the one-end opening 20Aa. As described above, the external tube 80 is temporarily fixed by the lock ring 50.

[0062] Next, the device connection portion 70 is further tightened to the main body 20. As a result, the device connection portion 70 is further inserted into the internal passage 20A toward the one-end opening 20Aa. Such insertion of the device connection portion 70 is performed against the reaction force that the second contact portion 42 of the second annular member 40 receives from the opposing surface 20Bg.

[0063] 3 and 5, the first other-side contact surface 30D of the device connection portion 70, which is further inserted into the internal passage 20A, presses the first surface 40Ba of the second annular member 40 toward the one-end opening 20Aa. Here, because the second contact portion 42 is in contact with the opposing surface 20Bg, the second annular member 40 cannot move toward the one-end opening 20Aa along the axial direction 101. Therefore, when the second annular member 40 receives a reaction force from the opposing surface 20Bg, the first contact portion 41 of the second annular member 40 moves inward in the radial direction 102 and bites into the outer peripheral surface 80A of the external pipe 80. Furthermore, when the second annular member 40 receives a reaction force from the opposing surface 20Bg, the second contact portion 42 moves outward in the radial direction 102 while still in contact with the opposing surface 20Bg.

[0064] 4 and 6, the second annular member 40 is configured to deform so that the first contact portion 41 moves inward in the radial direction 102 and bites into the outer peripheral surface 80A of the outer pipe 80, and the second contact portion 42 moves outward in the radial direction 102 while contacting the opposing surface 20Bg. Fig. 6 is an enlarged view of the portion enclosed by the dashed dotted line in Fig. 4.

[0065] As the first contact portion 41 moves inward in the radial direction 102, the first surface 40Ba of the second annular member 40 deforms so that its angle with respect to the axial direction 101 becomes steeper. That is, the end of the first surface 40Ba on the other-end opening 20Ab side moves inward in the radial direction 102. As a result, the first other-side contact surface 30D of the first annular member 30 pressed by the device connection portion 70 moves toward the second surface 40Bb while contacting the first surface 40Ba. In this way, the first annular member 30 pressed by the device connection portion 70 moves along the axial direction 101 toward the one-end opening 20Aa.

[0066] When the second other-side contact surface 30E of the first annular member 30 moves toward the one-end opening 20Aa and contacts the second surface 40Bb of the second annular member 40, the second other-side contact surface 30E receives a reaction force from the second surface 40Bb. As a result, the external force required to move the first annular member 30 along the axial direction 101 toward the one-end opening 20Aa increases compared to when the second other-side contact surface 30E is not in contact with the second surface 40Bb. This increases the external force required to further insert the device connection portion 70 into the internal passage 20A. As a result, a user who is fastening the device connection portion 70 to the main body 20 can recognize that further insertion of the device connection portion 70 into the main body 20 is not necessary.

[0067] When the first annular member 30 is pressed toward the one end opening 20Aa and contacts the second surface 40Bb, the outer circumferential surface 40B of the second annular member 40 is spaced apart from the main body inner circumferential surface 20B in the radial direction 102.

[0068] The pipe joint 10 according to this embodiment can achieve the following effects.

[0069] According to this embodiment, the second annular member 40, pressed by the first annular member 30, is deformed so that the first contact portion 41 bites into the outer peripheral surface 80A of the outer pipe 80. This allows the second annular member 40 to hold the outer pipe 80 inserted into the internal passage 20A of the main body 20.

[0070] Furthermore, according to this embodiment, when the second annular member 40 is pushed by the first annular member 30, the second contact portion 42 deforms so as to move outward in the radial direction 102 while contacting the opposing surface 20Bg. In other words, the second annular member 40 deforms so as to expand radially along the radial direction 102. This radially expanding deformation can prevent the external force required for the first annular member 30 to push the second annular member 40 from becoming too large.

[0071] Furthermore, according to this embodiment, the second contact portions 42 can be in line contact or point contact with the opposing surface 20Bg, which reduces the external force required to cause the second annular member 40 to deform radially as described above, compared to a configuration in which the second contact portions 42 are in surface contact with the opposing surface 20Bg.

[0072] Furthermore, according to the present embodiment, the second contact portion 42 is located outward from the first surface 40Ba in the radial direction 102. This makes it possible to prevent the external force required for the first annular member 30 to press the second annular member 40 from increasing, compared to a configuration in which the second contact portion 42 is not located outward from the first surface 40Ba in the radial direction 102.

[0073] As described above, according to this embodiment, it is possible to prevent an increase in the external force required for the first annular member 30 to press the second annular member 40 while holding the outer tube 80 inserted into the main body 20 by the second annular member 40. In other words, according to this embodiment, it is possible to reduce the external force required to ensure a desired holding force for the outer tube 80.

[0074] According to this embodiment, a configuration in which the second contact portion 42 can come into line contact or point contact with the opposing surface 20Bg can be realized with a simple configuration of a curved surface.

[0075] According to this embodiment, the second contact portion 42 protrudes toward the opposing surface 20Bg, which reduces the possibility that portions of the second annular member 40 other than the second contact portion 42 will come into contact with the opposing surface 20Bg. This reduces the contact area between the second annular member 40 and the opposing surface 20Bg, thereby reducing the external force required to deform the second annular member 40 so as to expand radially.

[0076] According to this embodiment, the first annular member 30, which is pushed toward the one-end opening 20Aa and moves along the axial direction 101, first contacts the first surface 40Ba of the second annular member 40 and pushes against the first surface 40Ba. This causes the portion of the second annular member 40 where the first surface 40Ba is provided to bend inward in the radial direction 102. As a result, the second annular member 40 is deformed such that the first contact portion 41 bites into the outer peripheral surface 80A of the outer pipe 80, and the outer pipe 80 is held by the second annular member 40.

[0077] Next, the first annular member 30 contacts the second surface 40Bb. The second surface 40Bb is inclined more steeply than the first surface 40Ba. Therefore, when the first annular member 30 contacts the second surface 40Bb, a large external force is required to move the first annular member 30 toward the one-end opening 20Aa. The difference in the external force before and after the first annular member 30 contacts the second surface 40Bb allows the user moving the first annular member 30 to determine whether further movement of the first annular member 30 is necessary. As a result, excessive insertion of the first annular member 30 into the main body 20 can be prevented, thereby preventing the first contact portion 41 from excessively biting into the outer tube 80, which would otherwise occur due to excessive insertion.

[0078] If the outer peripheral surface 40B of the second annular member 40 were to come into contact with the main body inner peripheral surface 20B in the radial direction 102, the radially expanding deformation of the second annular member 40 would be hindered, and the external force required to move the first annular member 30 would increase. According to this embodiment, in the process in which the first annular member 30 pushes the second annular member 40, the second annular member 40 does not come into contact with the main body inner peripheral surface 20B in the radial direction 102. Therefore, the external force required to push the first annular member 30 can be prevented from increasing.

[0079] According to this embodiment, the first contact portion 41 protrudes in the radial direction 102, which reduces the possibility that portions of the second annular member 40 other than the first contact portion 41 will come into contact with the outer peripheral surface 80A of the outer pipe 80. This makes it possible to keep the external force required to deform the second annular member 40 so that the first contact portion 41 bites into the outer peripheral surface 80A of the outer pipe 80 small.

[0080] According to this embodiment, the provision of the recess 20Ba makes it possible to increase the gap between the second annular member 40 and the main body inner circumferential surface 20B in the radial direction 102. This reduces contact of the second annular member 40 with the main body inner circumferential surface 20B in the radial direction 102 during the process in which the first annular member 30 presses the second annular member 40. As a result, it is possible to prevent the external force required to press the first annular member 30 from increasing.

[0081] According to this embodiment, the protrusion 30Ba of the first annular member 30 contacts the regulating surface 20Bc of the main body 20, thereby reducing the possibility of the first annular member 30 slipping out of the internal passage 20A of the main body 20 through the other end opening 20Ab.

[0082] According to this embodiment, the minimum gap G1 is smaller than the minimum gap G2. Therefore, at a position of the main body 20 corresponding to the minimum gap G1, the main body inner circumferential surface 20B can be extended further toward the internal passage 20A than at a position of the main body 20 corresponding to the minimum gap G2. This allows the thickness of the main body 20 in the radial direction 102 to be increased at the position of the main body 20 corresponding to the minimum gap G1. Here, the thickness of the main body 20 in the radial direction 102 is the length in the radial direction 102 between the main body inner circumferential surface 20B and the outer circumferential surface of the main body 20.

[0083] According to this embodiment, at least a portion of the lock ring 50 is provided inside the second annular member 40. Therefore, the second annular member 40 and the lock ring 50 can share the same arrangement space in the internal passage 20A of the main body 20. This reduces the arrangement space. Furthermore, when the second annular member 40 deforms so as to expand radially along the radial direction 102, the possibility of interference between the second annular member 40 and the lock ring 50 can be reduced. Furthermore, the support surface 40C supports the outer edge portion 51 of the lock ring 50, thereby stabilizing the position of the lock ring 50.

[0084] The pipe joint described above can also be expressed as follows.

[0085] (1) A pipe fitting according to one aspect of the present disclosure includes: A cylindrical body, a first annular member provided in the internal passage of the body so as to be movable along the axial direction of the body along the internal passage; a second annular member, which is provided in the internal passage between the first annular member and one end opening of the body into which an external pipe is inserted, and which is movable along the axial direction and into which the external pipe can be inserted; an inner circumferential surface of the main body that constitutes the internal passage has an opposing surface that is located between the second annular member and the one-end opening and that faces the second annular member in the axial direction; The second annular member is a first contact portion provided on an inner peripheral surface of the second annular member and in contact with an outer peripheral surface of the outer pipe inserted into the second annular member; at least one second contact portion that faces the opposing surface in the axial direction and is capable of line contact or point contact with the opposing surface; the first annular member is configured to move along the axial direction when pushed toward the one-end opening to push the second annular member toward the one-end opening; The second annular member is configured such that when the second contact portion is in contact with the opposing surface and the first annular member is pushed toward the one end opening, the first contact portion bites into the outer peripheral surface of the external tube and the second contact portion deforms so as to move radially outward from the main body while contacting the opposing surface.

[0086] (2) In the pipe fitting of (1), The second contact portion may have a curved surface that contacts the opposing surface.

[0087] (3) In the case of a pipe fitting as defined in (1) or (2), The second contact portion may protrude toward the opposing surface.

[0088] (4) In any one of the pipe fittings (1) to (3), The outer circumferential surface of the second annular member is a first surface that is provided opposite the first annular member in the axial direction and is inclined with respect to the axial direction so as to extend radially outward toward the opposing surface in the axial direction; a second surface that is provided opposite the first annular member and closer to the opposing surface in the axial direction than the first surface, and that extends along the radial direction or extends at a steeper incline with respect to the axial direction than the first surface, The first contact portion may be provided on the inner circumferential surface of the second annular member on the rear side of the first surface.

[0089] (5) In the pipe fitting of (4), When the first annular member is pushed toward the one end opening and contacts the second surface, the outer peripheral surface of the second annular member may be spaced apart from the inner peripheral surface of the main body in the radial direction.

[0090] (6) In any one of the pipe fittings (1) to (5), The first contact portion may protrude in the radial direction from an inner circumferential surface of the second annular member.

[0091] (7) In any one of the pipe fittings (1) to (6), The inner circumferential surface of the main body may have a recess provided over the entire periphery of the inner circumferential surface of the main body at a position facing the second annular member in the radial direction.

[0092] (8) In any one of the pipe fittings (1) to (7), The first annular member may include a protrusion protruding from an outer circumferential surface of the first annular member, The main body may be provided with a regulating surface located between the convex portion on the inner circumferential surface of the main body and the other end opening of the main body, which contacts the convex portion to prevent the first annular member from escaping from the internal passage through the other end opening.

[0093] (9) In any one of the pipe fittings (1) to (8), The minimum radial gap between the outer circumferential surface of the first annular member and the inner circumferential surface of the main body may be smaller than the minimum radial gap between the outer circumferential surface of the second annular member and the inner circumferential surface of the main body.

[0094] (10) Any one of the pipe fittings (1) to (9) is The second annular member may further include a lock ring, at least a portion of which is located inside the second annular member, into which the outer tube can be inserted, and which restricts the inserted outer tube from moving toward the one-end opening, The second annular member may have a support surface facing the one end opening and capable of supporting an outer edge portion of the lock ring.

[0095] Any of the various embodiments described above may be combined appropriately to achieve the effects of each of them.

[0096] While the present invention has been fully described in connection with preferred embodiments, with appropriate reference to the drawings, various changes and modifications will become apparent to those skilled in the art, and it is to be understood that such changes and modifications are included within the scope of the present invention as defined by the appended claims unless they depart therefrom. [Explanation of symbols]

[0097] 10 Pipe fittings 20 Main Unit 20A Internal Passage 20Aa one end open 20Ab Other end opening 20B Inner surface of main body 20Ba recess 20Bc Regulatory aspects 20Bg opposing surface 30 First annular member 30B Outer surface 30Ba convex part 40 Second annular member 40A inner surface 40B Outer surface 40Ba 1st page 40Bb 2nd side 40C support surface 41 1st contact part 42 Second contact part 50 Lock Ring 80 External tube 80A outer surface 101 Axial 102 Radial

Claims

1. A cylindrical body, a first annular member provided in the internal passage of the body so as to be movable in an axial direction of the body along the internal passage; a second annular member, which is provided in the internal passage between the first annular member and one end opening of the body into which an outer pipe is inserted, and which is movable along the axial direction and into which the outer pipe can be inserted; an inner circumferential surface of the main body that constitutes the internal passage has an opposing surface that is located between the second annular member and the one end opening and that faces the second annular member in the axial direction; The second annular member is a first contact portion provided on an inner peripheral surface of the second annular member and in contact with an outer peripheral surface of the outer pipe inserted into the second annular member; at least one second contact portion that faces the opposing surface in the axial direction and is capable of line contact or point contact with the opposing surface; the first annular member is configured to move along the axial direction when pushed toward the one-end opening to push the second annular member toward the one-end opening; the second annular member is configured such that, when the second contact portion is in contact with the opposing surface and is pushed toward the one end opening by the first annular member, the first contact portion bites into the outer peripheral surface of the external pipe and the second contact portion deforms so as to move radially outward from the main body while contacting the opposing surface.

2. The pipe joint according to claim 1 , wherein the second contact portion has a curved surface that contacts the opposing surface.

3. The pipe joint according to claim 1 or 2, wherein the second contact portion protrudes toward the opposing surface.

4. The outer circumferential surface of the second annular member is a first surface that is provided opposite the first annular member in the axial direction and is inclined with respect to the axial direction so as to extend radially outward toward the opposing surface in the axial direction; a second surface that is provided opposite the first annular member and closer to the opposing surface in the axial direction than the first surface, and that extends along the radial direction or extends at a steeper incline with respect to the axial direction than the first surface, 3. The pipe joint according to claim 1, wherein the first contact portion is provided on an inner circumferential surface of the second annular member on a rear side of the first surface.

5. 3. The pipe joint according to claim 1, wherein the first contact portion protrudes in the radial direction from an inner circumferential surface of the second annular member.

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