Pipe fittings

Abstract

To easily disassemble a pipe joint that has a locking mechanism.SOLUTION: A pipe joint 1 includes: a cylindrical female component 2 connected to a first hose 91 and having a female thread 25; a cylindrical male component 3 connected to a second hose 92 and having a male thread 33 to be fastened to the female thread 25; a locking mechanism 6 having a recess 61 and a projection 62, which engage each other axially to restrict loosening of the male thread 33 when the male thread 33 is tightened against the female thread 25 to a tightening completion position. The recess 61 is provided in the female component 2, and the projection 62 is provided in the male component 3. The female component 2 includes: a bending part 71 provided with a recess 81 and bendable and deformable so as to move to one side in an axial direction where the recess 61 is disengaged from the projection 62; a hooking part 72 extending from the bending part 71 to one side in the axial direction; and a hooked part 73 to which the hooking part 72 is hooked and held when the bending part 71 is deflected and deformed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] For example, the pipe fitting described in Patent Document 1 is known as a pipe fitting for connecting various pipes such as rubber hoses and metal pipes arranged in an automobile. The pipe fitting of Patent Document 1 comprises a male part (joint body) to which one pipe is connected, a female part (nut) to which another pipe is connected, and an anti-loosening mechanism. The male part is formed with a male thread, and the female part is formed with a female thread into which the male thread of the male part is fastened.

[0003] The locking mechanism is composed of a recessed receiving portion provided on the outer periphery of the male part and a cantilevered claw portion provided on the outer periphery of the female part. When the male thread of the male part is tightened to the appropriate position against the female thread of the female part, the claw portion of the female part engages with the receiving portion of the male part. This prevents the male thread of the male part from loosening relative to the female thread of the female part, even if the vehicle vibrates while in motion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-162060 Summary of the Invention [Problem to be solved by the invention]

[0005] When disassembling the male and female parts of the pipe fitting, the operator must bend the claws radially outward to disengage them from the receiving parts, and then, while maintaining this state, rotate the male part in a direction to loosen it relative to the female part. This makes the disassembly process complicated, and improvements in operability are desired.

[0006] The present disclosure has been made in consideration of the above circumstances, and has an object to make it possible to easily disassemble a pipe joint equipped with an anti-loosening mechanism. [Means for solving the problem]

[0007] (1) The present disclosure relates to a pipe fitting comprising: a cylindrical female part connected to one pipe and having a female thread; a cylindrical male part connected to another pipe and having a male thread to be screwed into the female thread; and an anti-loosening mechanism having a first engaging portion and a second engaging portion that axially engage with each other to restrict loosening of the male thread when the male thread is screwed onto the female thread to a fully screwed position, wherein the first engaging portion is provided on one of the female part and the male part, and the second engaging portion is provided on the other of the female part and the male part, and the one part comprises: a flexible portion that is provided with the first engaging portion and is flexibly deformable so that the first engaging portion moves to one axial side to release engagement with the second engaging portion; a hooking portion extending from the flexible portion to the one axial side; and a hooked portion on which the hooking portion is hooked and held when the flexible portion is flexibly deformed.

[0008] According to the pipe fitting of the present disclosure, when the male thread of the male part is tightened to the female thread of the female part to the tightening completion position, the first engaging portion and the second engaging portion of the locking mechanism engage with each other in the axial direction, thereby restricting loosening of the male thread of the male part relative to the female thread of the female part. When disassembling the pipe fitting from this state, an operator flexes and deforms a flexible portion provided on one of the female and male parts toward one axial direction. This moves the first engaging portion toward one axial direction, thereby disengaging the first engaging portion from the second engaging portion. In this state, an operator hooks the hooking portion extending from the flexible portion toward one axial direction onto the hooked portion, thereby holding the first engaging portion and the second engaging portion in a disengaged state. From this state, an operator can remove the male part from the female part by rotating the male part in a direction that loosens the male part relative to the female part. This allows for easy disassembly of a pipe fitting equipped with a locking mechanism.

[0009] (2) In the pipe fitting of (1), it is preferable that the fitting further comprises a first protrusion provided on one of the components so as to protrude radially outward from a portion of the circumference of the one component, and a second protrusion provided on the other component so as to protrude radially outward from a portion of the circumference of the other component, and that when the male screw is tightened to the tightening completion position, its circumferential position coincides with that of the first protrusion, and that the flexible portion, the hooking portion, and the hooked portion are each formed by a portion of the first protrusion. In this case, when the male thread of the male part is tightened to the female thread of the female part to the tightening completion position, the circumferential position of the first protrusion and the circumferential position of the second protrusion coincide, so the worker can easily know that the male thread of the male part has been tightened to the tightening completion position. Furthermore, because the flexible portion, the hooking portion, and the hooked portion are each formed by part of the first protrusion, there is no need to provide them separately from the first protrusion. This simplifies the configuration of the one of the parts.

[0010] (3) In the pipe fitting of (2), it is preferable that the first protruding portion has a slit formed therein that extends radially inward from an axial midpoint on its protruding end face, the flexible portion and the hooking portion are formed in a portion of the first protruding portion on the other axial side of the slit, and the hooked portion is formed in a portion of the first protruding portion on one axial side of the slit. In this case, by forming a slit in the first protruding portion, the flexible portion, the hooking portion, and the hooked portion can be easily formed. [Effects of the Invention]

[0011] According to the present disclosure, a pipe joint equipped with an anti-loosening mechanism can be easily disassembled. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a pipe fitting according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view of the pipe joint as seen from the opposite side of FIG. 1. [Figure 3]FIG. 2 is an axial cross-sectional view of the pipe joint of FIG. 1. [Figure 4] FIG. 2 is a plan view of the pipe joint of FIG. 1. [Figure 5] FIG. 4 is an enlarged cross-sectional view of a main part of FIG. 3. [Figure 6] FIG. 10 is an enlarged cross-sectional view of a main part showing a state in which a flexible portion is slightly flexible and deformed. [Figure 7] 10 is an enlarged cross-sectional view of a main part showing a state in which a hooking portion is hooked onto a hooked portion. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Next, preferred embodiments will be described with reference to the accompanying drawings. Note that at least some of the embodiments described below may be combined in any manner. [Overall configuration] Fig. 1 is a perspective view of a pipe fitting 1 according to an embodiment of the present disclosure. Fig. 2 is a perspective view of the pipe fitting 1 as viewed from the opposite side of Fig. 1. Fig. 3 is an axial cross-sectional view of the pipe fitting 1 of Fig. 1. In Figs. 1 to 3, the pipe fitting 1 is provided in a cooling line of a battery pack of an electric vehicle (EV), for example, and is used to connect a first hose (one pipe) 91 and a second hose (another pipe) 92 through which coolant (LLC) passes. The first hose 91 and the second hose 92 are made of a resin material, for example, high-density polyethylene (HDPE).

[0014] The pipe fitting 1 comprises a female part 2 and a male part 3. Both the female part 2 and the male part 3 are cylindrically formed from a resin material such as polyamide (PA) or glass fiber reinforced polyamide (PA-GF). The female part 2 and the male part 3 have the same inner diameter and are fastened to each other while being arranged on the same axis C.

[0015] The female part 2 is connected to a first hose 91, and the male part 3 is connected to a second hose 92. As a result, the internal spaces of the female part 2 and the male part 3 communicate with the internal spaces of the first hose 91 and the second hose 92. In other words, the internal spaces of the female part 2 and the male part 3 function as a flow path for the LLC connecting the two hoses 91, 92.

[0016] Hereinafter, in this specification, the "axial direction" refers to a direction along the axis C (including a direction parallel to this center line). For convenience, the right side of FIG. 3 is referred to as "one axial side," and the left side of FIG. 3 is referred to as "the other axial side." Furthermore, in this specification, the "radial direction" refers to a direction perpendicular to the axis C, and the "circumferential direction" refers to a direction around the axis C.

[0017] [Female part] The female component 2 has a first female part 21 formed on one axial side and a second female part 22 formed on the other axial side. The first female part 21 is the connection part with the first hose 91. The outer diameter of the first female part 21 is slightly larger than the inner diameter of the first hose 91. The first female part 21 is press-fitted into the first hose 91 and pushes open the open end of the first hose 91. The inner circumferential surface of the open end of the first hose 91 tightens the outer circumferential surface of the first female part 21 radially inward due to its restoring force. This connects the first female part 21 to the first hose 91, and a seal is formed between the outer circumferential surface of the first female part 21 and the inner circumferential surface of the first hose 91.

[0018] The second female part 22 is a connecting portion with the male component 3. The second female part 22 has a seal part 23 that protrudes radially inward toward the other axial direction, and an outer tubular part 24 that protrudes radially outward toward the other axial direction, on the radially outward side. The seal part 23 is formed in a cylindrical shape. The outer tubular part 24 is formed in a cylindrical shape with a gap radially outward from the seal part 23. A female thread 25 is formed on the inner periphery of the outer tubular part 24. The female thread 25 is, for example, a multiple-start thread such as a double-start thread.

[0019] [Male part] The male component 3 comprises a first male part 31 formed on the other axial side and a second male part 32 formed on one axial side. The first male part 31 is the connection part with the second hose 92. The outer diameter of the first male part 31 is slightly larger than the inner diameter of the second hose 92. The first male part 31 is press-fitted into the second hose 92, pushing open the open end of the second hose 92. The inner circumferential surface of the open end of the second hose 92 tightens the outer circumferential surface of the first male part 31 radially inward due to its restoring force. In this way, the first male part 31 is connected to the second hose 92, and a seal is formed between the outer circumferential surface of the first male part 31 and the inner circumferential surface of the second hose 92.

[0020] The second male portion 32 is the connecting portion with the female component 2. The inner diameter of the second male portion 32 is the same as the inner diameter of the first male portion 31, and the outer diameter of the second male portion 32 is larger than the outer diameter of the first male portion 31. As a result, the radial thickness of the second male portion 32 is larger than the radial thickness of the first male portion 31. A male thread 33 is formed on one axial side of the outer circumference of the second male portion 32. The male thread 33 is made of a thread that can mesh with the female thread 25 of the female component 2. The male thread 33 in this embodiment is made of a multiple-start thread, for example a double-start thread.

[0021] A seal groove 34 that opens to one axial side (the female part 2 side) is formed in the second male part 32. The seal groove 34 is formed in an annular shape so that the seal portion 23 of the female part 2 can be press-fitted into it. The outer diameter of the seal groove 34 is the same as the outer diameter of the seal portion 23, and the inner diameter of the seal groove 34 is slightly larger than the inner diameter of the seal portion 23.

[0022] As described above, when the male thread 33 of the male part 3 is tightened into the female thread 25 of the female part 2, the seal portion 23 of the female part 2 is press-fitted into the seal groove 34 of the male part 3. When the seal portion 23 is press-fitted into the seal groove 34, the inner circumferential surface of the seal portion 23 and the inner circumferential surface of the seal groove 34 come into close contact with each other, thereby sealing the connection between the female part 2 and the male part 3.

[0023] [Protrusion] The pipe fitting 1 further comprises a female protrusion (first protrusion) 4 provided on the female part 2 (one of the parts) and a male protrusion (second protrusion) 5 provided on the male part 3. The female protrusion 4 is made of the same resin material as the female part 2 and is molded integrally with the female part 2 by, for example, injection molding. Similarly, the male protrusion 5 is made of the same resin material as the male part 3 and is molded integrally with the male part 3 by, for example, injection molding.

[0024] The female protrusion 4 protrudes radially outward from a portion of the circumference of the second female portion 22. The male protrusion 5 protrudes radially outward from a portion of the circumference of the second male portion 32. The female protrusion 4 and the male protrusion 5 are formed to have the same outer shape, and in this embodiment, for example, are formed to have a substantially triangular prism shape with the radially outer end tapering. The female protrusion 4 has a recess 41 formed therein. The recess 41 opens on one axial side and one circumferential side (the right side in FIG. 2) of the female protrusion 4. Similarly, the male protrusion 5 has a recess 51 formed therein. The recess 51 opens on the other axial side and the other circumferential side (the right side in FIG. 1) of the male protrusion 5. These recesses 41, 51 prevent the protrusions 4, 5 from shrinking and deforming after injection molding.

[0025] The circumferential position of the female protrusion 4 on the second female part 22 and the circumferential position of the male protrusion 5 on the second male part 32 are set so that the circumferential positions of both protrusions 4, 5 will match when the male screw 33 is tightened to the appropriate tightening-completed position relative to the female screw 25. By visually confirming that the circumferential positions of the female protrusion 4 and the male protrusion 5 match, the worker can determine that the male screw 33 is in the tightening-completed position.

[0026] [Anti-loosening mechanism] Figure 4 is a plan view of the pipe fitting 1 of Figure 1. In Figure 4, the pipe fitting 1 further includes an anti-loosening mechanism 6 that restricts loosening of the male thread 33 when the male thread is in the fully tightened position. The anti-loosening mechanism 6 has a recess 61 provided on the female part 2 as a first engagement portion, and a protrusion 62 provided on the male part 3 as a second engagement portion.

[0027] The recess (first engagement portion) 61 in this embodiment is formed at the radially outer end (protruding end) of the side surface 42 on the other axial side of the female protrusion 4. A tapered surface 42a is formed adjacent to the recess 61 on the side surface 42 of the female protrusion 4. The tapered surface 42a is disposed adjacent to the recess 61 on the opposite side of the tightening direction of the female thread 25 (upper side in Figure 4). The tapered surface 42a is formed so as to gradually protrude toward the other axial side as it approaches the tightening direction.

[0028] In this embodiment, the convex portion (second engaging portion) 62 is formed on the radially outer end (protruding end) of the side surface 52 on one axial side of the male protruding portion 5. When the male screw 33 is tightened immediately before the tightening completion position, the convex portion 62 comes into contact with the tapered surface 42a. When the male screw 33 is tightened further from this state, the convex portion 62 moves in the tightening direction (downward in Figure 4) while pressing the tapered surface 42a to one axial side.

[0029] At this time, a flexible portion 71 (described later) provided with the recessed portion 61 is flexibly deformed to one side in the axial direction, thereby allowing the protruding portion 62 to move in the tightening direction (downward in FIG. 4). Furthermore, when the male screw 33 is tightened to the tightening completion position, the protruding portion 62 moves over the tapered surface 42a and fits into the recessed portion 61. As a result, the recessed portion 61 and the protruding portion 62 are engaged with each other in the axial direction, and loosening of the male screw 33 at the tightening completion position is restricted.

[0030] [Disengagement mechanism] 1 to 3, the female part 2 is provided with a disengagement mechanism 7 that disengages the recessed portion 61 and the protruding portion 62 of the locking mechanism 6. The disengagement mechanism 7 is provided with a flexible portion 71, a hooking portion 72, and a hooked portion 73. The flexible portion 71, the hooking portion 72, and the hooked portion 73 are each provided on the female protrusion 4. In this embodiment, the flexible portion 71, the hooking portion 72, and the hooked portion 73 are each formed by a portion of the female protrusion 4.

[0031] The female protrusion 4 is formed with slits 44 for forming the respective parts 71 to 73 of the disengagement mechanism 7. The slits 44 extend radially inward from an axial midpoint on the protruding end surface 43 of the female protrusion 4. The slits 44 are formed on the other axial side of the recessed portion 41 across the entire width of the female protrusion 4 (the direction perpendicular to the plane of the paper in FIG. 3). Therefore, the slits 44 are open on both circumferential sides of the female protrusion 4.

[0032] A flexible portion 71 and a hook portion 72 of the disengagement mechanism 7 are formed in a portion of the female protrusion 4 on the other axial side of the slit 44. In this embodiment, the portion of the female protrusion 4 on the other axial side is the flexible portion 71, and the hook portion 72 is formed integrally with the flexible portion 71. The flexible portion 71 is formed in a thin plate shape and extends in the radial direction. The side surface on the other axial side of the flexible portion 71 is the side surface 42 on which the recess 61 is provided in the female protrusion 4. Therefore, the recess 61 of the locking mechanism 6 is provided on the side surface 42 on the other axial side of the flexible portion 71. A gap S is formed between the side surface 42 of the flexible portion 71 and the side surface 52 of the male protrusion 5, radially inward of the locking mechanism 6.

[0033] The slit 44 is adjacent to one axial side of the flexible portion 71. This allows the flexible portion 71 to flexibly deform such that the radially outer end moves toward one axial side, starting from the radially inner end. When the flexible portion 71 flexes and deforms, the recessed portion 61 moves toward one axial side. Therefore, when the flexible portion 71 flexes and deforms, the engagement between the recessed portion 61 and the protruding portion 62 of the locking mechanism 6 can be released.

[0034] The hook portion 72 extends from the radially outer end of the flexible portion 71 to one axial side (toward the slit 44). The hook portion 72 is formed in a thin plate shape and is supported in a cantilever manner relative to the flexible portion 71. The axial length of the hook portion 72 is preferably formed relatively short so that the flexible portion 71 is unlikely to bend and deform (so that the engagement between the recessed portion 61 and the protruding portion 62 is unlikely to be released) even if an operator presses the hook portion 72 radially inward.

[0035] Figure 5 is an enlarged cross-sectional view of a main portion of Figure 3. In Figures 3 and 5, a flat surface 72a, a locking surface 72b, and a tapered surface 72c are formed in this order on the radially inner side of the hook portion 72 from the other axial end toward one axial end. The flat surface 72a extends from the other axial end of the hook portion 72 to one axial side. The locking surface 72b is formed to protrude radially inward from one axial end of the flat surface 72a. The locking surface 72b is formed perpendicular to the flat surface 72a. The tapered surface 72c is a convex curved surface formed to gradually protrude radially inward from the other axial end of the hook portion 72 toward the radially inner end of the locking surface 72b.

[0036] A step portion 45 is formed in a portion of the female protrusion 4 on one axial side of the slit 44. The step portion 45 is formed adjacent to the slit 44 at the radially outer end of the portion on one axial side. The step portion 45 has a first step surface 45a extending radially and a second step surface 45b extending axially. The second step surface 45b extends from the radially inner end of the first step surface 45a to the other axial side. A hooked portion 73 of the disengagement mechanism 7 is integrally formed on the second step surface 45b. The hooked portion 73 is a portion on which the locking surface 72b of the hook portion 72 is hooked and held when the flexible portion 71 is flexibly deformed on one axial side.

[0037] The hooked portion 73 protrudes radially outward from the end of the second step surface 45b on the slit 44 side. The radially outer surface of the hooked portion 73 is a tapered surface 73b. The tapered surface 73b is a convex curved surface that gradually protrudes radially outward from the other axial end toward the one axial end. The tapered surface 73b of the hooked portion 73 is positioned so that it can come into contact with the tapered surface 72c of the hooking portion 72.

[0038] One axial side surface of the hooked portion 73 serves as a locking surface 73a on which the locking surface 72b of the hooking portion 72 is hooked and locked (see FIG. 7). The locking surface 73a of the hooked portion 73 is positioned so that the locking surface 72b of the hooking portion 72 is locked when the amount of deflection deformation of the flexible portion 71 toward one axial side reaches a predetermined amount.

[0039] The predetermined amount is set to the amount of deflection when the flexible portion 71 deflects until the engagement between the recessed portion 61 and the protruding portion 62 is released. Therefore, the predetermined amount is greater than the amount of deflection when the protruding portion 62 on the male part 3 abuts against the tapered surface 42a on the female part 2 (see FIG. 4), as described above. For this reason, even if the flexible portion 71 deflects to one axial side when the protruding portion 62 on the male part 3 abuts against the tapered surface 42a on the female part 2, the locking surface 72b of the hooking portion 72 will not be caught on the locked surface 73a of the hooked portion 73.

[0040] Next, the procedure for disassembling the pipe fitting 1 from the state shown in Figure 5 will be described. First, an operator inserts the tip 101 of a flat-head screwdriver 100, which is a general-purpose tool, into the gap S between the female protruding portion 4 and the male protruding portion 5, and rotates the tip 101 in the clockwise direction in Figure 5. As a result, the tip 101 of the flat-head screwdriver 100 comes into contact with the side surface 42 of the flexible portion 71 and the side surface 52 of the male protruding portion 5, respectively, and a pressing force acts on the flexible portion 71 toward one axial side. As a result, the flexible portion 71 is slightly deflected and deformed toward one axial side.

[0041] The pressing force causes flexible portion 71 to bend slightly toward one side in the axial direction. As a result, as shown in Figure 6, hooking portion 72 moves toward one side in the axial direction together with flexible portion 71, and tapered surface 72c of hooking portion 72 abuts against tapered surface 73b of hooked portion 73. The operator further rotates tip portion 101 of flat-head screwdriver 100 from the state shown in Figure 6, causing flexible portion 71 to be further bent toward one side in the axial direction.

[0042] 7, when the amount of bending deformation of the bending portion 71 toward one side in the axial direction reaches a predetermined amount, the tapered surface 72c of the hooking portion 72 climbs over the tapered surface 73b of the hooked portion 73, and the locking surface 72b of the hooking portion 72 is locked with the locked surface 73a of the hooked portion 73. At this time, the engagement between the recessed portion 61 and the protruding portion 62 of the locking mechanism 6 is also released. Therefore, as the locking surface 72b is locked with the locked surface 73a, the hooking portion 72 is hooked and held by the hooked portion 73, and the recessed portion 61 and the protruding portion 62 of the locking mechanism 6 are held in a disengaged state.

[0043] Next, the worker removes tip 101 of flat-head screwdriver 100 from gap S, rotates it in a direction that loosens male part 3 relative to female part 2, and removes male part 3 from female part 2. This brings pipe fitting 1 into a disassembled state.

[0044] [Action and effect] According to the pipe fitting 1 of this embodiment, when the male thread 33 of the male part 3 is tightened to the female thread 25 of the female part 2 to the tightening completion position, the recessed portion 61 and the protruding portion 62 of the locking mechanism 6 engage with each other in the axial direction, thereby restricting loosening of the male thread 33 of the male part 3 relative to the female thread 25 of the female part 2. To disassemble the pipe fitting 1 from this state, the worker flexes and deforms the flexible portion 71 provided on the female part 2 toward one axial side. This moves the recessed portion 61 toward one axial side, thereby disengaging the recessed portion 61 from the protruding portion 62. In this state, the worker hooks the hooking portion 72 extending from the flexible portion 71 toward one axial side onto the hooked portion 73, thereby maintaining the recessed portion 61 and the protruding portion 62 in a disengaged state. From this state, the worker can remove the male part 3 from the female part 2 by rotating the male part 3 relative to the female part 2 in a direction to loosen it. This allows the pipe fitting 1 equipped with the locking mechanism 6 to be easily disassembled. In particular, the pipe fitting 1 of this embodiment is more effective when the flexible portion 71 is made difficult to flex and deform as described above, and the recessed portion 61 and the protruding portion 62 of the anti-loosening mechanism 6 do not disengage unless the flexible portion 71 is intentionally bent using a tool such as a flathead screwdriver 100.

[0045] When the male thread 33 of the male part 3 is tightened into the female thread 25 of the female part 2 to the tightening completion position, the circumferential position of the female protrusion 4 and the circumferential position of the male protrusion 5 coincide. This allows the operator to easily know that the male thread 33 of the male part 3 has been tightened to the tightening completion position. Furthermore, because the flexible portion 71, the hooking portion 72, and the hooked portion 73 are each formed from a part of the female protrusion 4, there is no need to provide them separately from the female protrusion 4. This simplifies the configuration of the female part 2.

[0046] By forming the slit 44 in the female protrusion 4, the flexible portion 71, the hooking portion 72, and the hooked portion 73 are each formed, so that each portion 71 to 73 of the disengagement mechanism 7 can be easily formed in the female protrusion 4.

[0047] [others] The pipe fitting 1 of the above embodiments is not limited to use in electric vehicles. In the anti-loosening mechanism 6 of each of the above embodiments, the first engagement portion is a recess 61 and the second engagement portion is a protrusion 62, but the first engagement portion may be a protrusion and the second engagement portion may be a recess. The disengagement mechanism 7 of the above embodiments is configured to flexibly deform the flexible portion 71 with a tool (flathead screwdriver 100), but it may also be configured to flexibly deform the flexible portion 71 manually without using a tool.

[0048] The flexible portion 71, hooking portion 72, and hooked portion 73 of the disengagement mechanism 7 in the above embodiment may be provided separately from the female protrusion 4. Furthermore, the flexible portion 71, hooking portion 72, and hooked portion 73 may be provided only on the male part 3. In this case, the convex portion 62 serves as the first engagement portion, and the concave portion 61 serves as the second engagement portion. Furthermore, the flexible portion 71, hooking portion 72, and hooked portion 73 on the male part 3 side may be provided integrally with the male protrusion 5, or may be provided separately from the male protrusion 5. Furthermore, the flexible portion 71, hooking portion 72, and hooked portion 73 may be provided on both the female part 2 and the male part 3.

[0049] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0050] 1 Pipe fittings 2 female parts 3 Male parts 4 Female protrusion (first protrusion) 5 Male protrusion (second protrusion) 6 Anti-loosening mechanism 25 female thread 33 Male thread 43 Projecting end surface 44-way slit 61 recess (first engagement portion) 62 convex portion (second engagement portion) 71 Flexure 72 Hook 73 Hooked part 91 First hose (first piping) 92 No. 1 hose (other piping)

Claims

1. a cylindrical female part connected to one pipe and having a female thread; a cylindrical male part having a male thread that is connected to another pipe and is fastened to the female thread; a loosening prevention mechanism having a first engaging portion and a second engaging portion that axially engage with each other to restrict loosening of the male thread when the male thread is tightened to a tightening completion position relative to the female thread, the first engaging portion is provided on one of the female component and the male component, the second engaging portion is provided on the other of the female component and the male component, The one part is a flexible portion provided with the first engaging portion and flexible and deformable so as to move to one axial side where the first engaging portion is disengaged from the second engaging portion; a hook portion extending from the flexible portion to one side in the axial direction; a hooked portion on which the hooking portion is hooked and held when the flexible portion is bent and deformed.

2. a first protruding portion provided at a circumferential portion of the one component so as to protrude radially outward; a second protruding portion provided at a portion of the circumference of the other component so as to protrude radially outward, and whose circumferential position coincides with that of the first protruding portion when the male screw is tightened to the tightening completion position, 2. The pipe joint according to claim 1, wherein the flexible portion, the hooking portion, and the hooked portion are each formed by a part of the first protruding portion.

3. The first protruding portion has a slit formed on its protruding end surface, the slit extending radially inward from a midpoint in the axial direction, the flexible portion and the hook portion are formed in a portion of the first protruding portion on the other axial side of the slit, 3. The pipe joint according to claim 2, wherein the hooked portion is formed in a portion of the first protruding portion on one side of the slit in the axial direction.

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