JP7824181B2 - Pipe fittings - Google Patents

Description

The present invention relates to a pipe fitting.

The pipe fitting described in Patent Document 1 is known as a pipe fitting used to connect various pipes, such as rubber hoses and metal pipes, placed inside an automobile. The pipe fitting in 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 tightened.

The locking mechanism consists of a recessed receiving portion on the outer periphery of the male part and a cantilevered claw portion on the outer periphery of the female part. When the male thread of the male part is tightened to the correct 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.

Japanese Patent Application Laid-Open No. 2021-162060

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

This disclosure was made in light of these circumstances, and aims to make it possible to easily disassemble pipe fittings equipped with anti-loosening mechanisms.

(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 that is screwed into the female thread; and a loosening prevention mechanism having a first engaging portion and a second engaging portion that axially engage with each other to prevent loosening of the male thread when the male thread is screwed into the female thread to a fully screwed position. 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. The one of the parts is provided with the first engaging portion and comprises: a flexible portion that is flexibly deformable so that the first engaging portion moves to one axial side to disengage from the second engaging portion; a hook portion extending from the flexible portion to one axial side; and a hooked portion that hooks and holds the hook portion when the flexible portion is flexibly deformed.

In the pipe fitting disclosed herein, when the male thread of the male component is tightened to the fully tightened position relative to the female thread of the female component, the first and second engagement portions of the locking mechanism engage with each other in the axial direction, thereby restricting loosening of the male thread of the male component relative to the female thread of the female component. To disassemble the pipe fitting from this state, the operator flexes and deforms the flexible portion provided on one of the female and male components toward one axial direction. This moves the first engagement portion toward one axial direction, thereby disengaging the first and second engagement portions. In this state, the operator hooks the hook portion extending from the flexible portion toward one axial direction onto the hooked portion, thereby maintaining the first and second engagement portions in a disengaged state. From this state, the operator can remove the male component from the female component by rotating the male component relative to the female component in the direction that loosens the male component. This allows for easy disassembly of pipe fittings equipped with a locking mechanism.

(2) The pipe fitting of (1) further comprises a first protruding portion protruding radially outward from a portion of the circumference of one of the components, and a second protruding portion protruding radially outward from a portion of the circumference of the other component, the second protruding portion being aligned in circumferential position with the first protruding portion when the male screw is tightened to the tightening completion position, and it is preferable that the flexible portion, the hooking portion, and the hooked portion are each formed by a portion of the first protruding portion.
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 operator can easily know that the male thread of the male part has been tightened to the tightening completion position. Furthermore, since 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.

(3) In the pipe fitting of (2), it is preferable that the first protruding portion has a slit extending 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.

This disclosure makes it possible to easily disassemble pipe fittings equipped with anti-loosening mechanisms.

FIG. 1 is a perspective view of a pipe fitting according to an embodiment of the present disclosure. FIG. 2 is a perspective view of the pipe joint as seen from the opposite side of FIG. 1 . FIG. 2 is an axial cross-sectional view of the pipe joint of FIG. 1 . FIG. 2 is a plan view of the pipe joint of FIG. 1; FIG. 4 is an enlarged cross-sectional view of a main part of FIG. 3 . 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. 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.

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).

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 positioned on the same axis C.

The female component 2 is connected to the first hose 91, and the male component 3 is connected to the second hose 92. As a result, the internal spaces of the female component 2 and the male component 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 component 2 and the male component 3 function as a flow path for the LLC connecting the two hoses 91, 92.

Hereinafter, in this specification, the "axial direction" refers to the direction along the axis C (including the direction parallel to this center line). For convenience, the right side of Figure 3 will be referred to as "one axial side," and the left side of Figure 3 will be referred to as "the other axial side." Also, in this specification, the "radial direction" refers to the direction perpendicular to the axis C, and the "circumferential direction" refers to the direction around the axis C.

[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, pushing 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 creates a seal between the outer circumferential surface of the first female part 21 and the inner circumferential surface of the first hose 91.

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

[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. This connects the first male part 31 to the second hose 92, creating a seal between the outer circumferential surface of the first male part 31 and the inner circumferential surface of the second hose 92.

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 a thread that can mesh with the female thread 25 of the female component 2. In this embodiment, the male thread 33 is a multiple-start thread, such as a double-start thread.

A seal groove 34 is formed in the second male part 32, opening to one axial side (the female part 2 side). 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.

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-fit into the seal groove 34 of the male part 3. When the seal portion 23 is press-fit 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, sealing the connection between the female part 2 and the male part 3.

[Protrusion]
The pipe fitting 1 further includes 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.

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 with the same outer shape; for example, in this embodiment, they are formed into a generally triangular prism shape with a tapered radial outer end. The female protrusion 4 has a recess 41 formed therein. The recess 41 opens on one axial side and one circumferential side (right side in Figure 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 (right side in Figure 1) of the male protrusion 5. These recesses 41, 51 prevent the protrusions 4, 5 from shrinking and deforming after injection molding.

The circumferential position of the female protrusion 4 on the second female portion 22 and the circumferential position of the male protrusion 5 on the second male portion 32 are set so that the circumferential positions of both protrusions 4, 5 coincide with each other 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 coincide with each other, the operator can determine that the male screw 33 is in the tightening-completed position.

[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 a locking mechanism 6 that restricts loosening of the male thread 33 when the male thread is in the fully tightened position. The locking mechanism 6 has a recess 61 as a first engagement portion provided on the female part 2, and a protrusion 62 as a second engagement portion provided on the male part 3.

In this embodiment, the recess (first engagement portion) 61 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 positioned 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 that it gradually protrudes toward the other axial side as it approaches the tightening direction.

In this embodiment, the convex portion (second engagement portion) 62 is formed on the radially outer end (protruding end) of the side surface 52 on one axial side of the male protrusion 5. When the male screw 33 is tightened just before the tightening completion position, the convex portion 62 abuts 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.

At this time, the flexible portion 71 (described below) provided with the recessed portion 61 flexes and deforms in one axial direction, allowing the protruding portion 62 to move in the tightening direction (downward in Figure 4). Furthermore, when the male screw 33 is tightened to the tightening completion position, the protruding portion 62 overcomes the tapered surface 42a and fits into the recessed portion 61. This causes the recessed portion 61 and the protruding portion 62 to engage with each other in the axial direction, preventing loosening of the male screw 33 in the tightening completion position.

[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.

The female protrusion 4 has slits 44 formed therein to form the various components 71-73 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 Figure 3). Therefore, the slits 44 are open on both circumferential sides of the female protrusion 4.

A flexible portion 71 and a hook portion 72 of the disengagement mechanism 7 are formed in the 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 integrally formed with the flexible portion 71. The flexible portion 71 is formed in a thin plate shape and extends radially. 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. Note that 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.

A slit 44 is adjacent to one axial side of the flexible portion 71. This allows the flexible portion 71 to flex and deform, with the radially inner end as the starting point and the radially outer end moving to one axial side. Flexing and deforming the flexible portion 71 causes the recessed portion 61 to move to one axial side. Therefore, flexing and deforming the flexible portion 71 can release the engagement between the recessed portion 61 and the protruding portion 62 of the locking mechanism 6.

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 cantilevered 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 less likely to bend and deform (so that the engagement between the recessed portion 61 and the protruding portion 62 is less likely to be released) even if an operator presses the hook portion 72 radially inward.

Figure 5 is an enlarged cross-sectional view of a key 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 that gradually protrudes radially inward as it moves from the other axial end of the hook portion 72 toward the radially inner end of the locking surface 72b.

A step portion 45 is formed in 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. The hooked portion 73 of the disengagement mechanism 7 is integrally formed with the second step surface 45b. The hooked portion 73 is the portion on which the locking surface 72b of the hook portion 72 hooks and is held when the flexible portion 71 is flexiblely deformed on one axial side.

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.

The side surface on one axial direction of the hooked portion 73 is the hooked surface 73a onto which the hooking surface 72b of the hooking portion 72 hooks and engages (see Figure 7). The hooked surface 73a of the hooked portion 73 is positioned so that the hooking surface 72b of the hooking portion 72 engages when the amount of deflection deformation of the flexible portion 71 toward one axial direction reaches a predetermined amount.

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 component 3 abuts against the tapered surface 42a on the female component 2 (see Figure 4), as described above. Therefore, even if the flexible portion 71 deflects to one axial side when the protruding portion 62 on the male component 3 abuts against the tapered surface 42a on the female component 2, the locking surface 72b of the hooking portion 72 will not catch on the locked surface 73a of the hooked portion 73.

Next, the procedure for disassembling the pipe fitting 1 from the state shown in Figure 5 will be described. First, the worker inserts the tip 101 of a flat-head screwdriver 100, which is a general-purpose tool, into the gap S between the female protrusion 4 and the male protrusion 5, and rotates the tip 101 clockwise 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 protrusion 5, respectively, and a pressing force is applied to the flexible portion 71 in one axial direction. This causes the flexible portion 71 to bend slightly in one axial direction.

The pressing force causes the flexible portion 71 to bend slightly toward one side in the axial direction. As a result, as shown in Figure 6, the hooking portion 72 moves toward one side in the axial direction along with the flexible portion 71, and the tapered surface 72c of the hooking portion 72 abuts against the tapered surface 73b of the hooked portion 73. The operator further rotates the tip 101 of the flathead screwdriver 100 from the state shown in Figure 6, further bending the flexible portion 71 toward one side in the axial direction.

When the amount of flexural deformation of the flexible portion 71 in one axial direction reaches a predetermined amount, as shown in Figure 7, the tapered surface 72c of the hooking portion 72 overcomes the tapered surface 73b of the hooked portion 73, causing the locking surface 72b of the hooking portion 72 to lock onto the locking 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 locks onto the locking surface 73a, the hooking portion 72 is hooked onto and held by the hooked portion 73, and the recessed portion 61 and protruding portion 62 of the locking mechanism 6 are held in a disengaged state.

Next, the worker removes the tip 101 of the flathead screwdriver 100 from the gap S and rotates it in a direction that loosens the male part 3 relative to the female part 2, thereby removing the male part 3 from the female part 2. This leaves the pipe fitting 1 in a disassembled state.

[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, an operator 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, an operator hooks the hooking portion 72 extending from the flexible portion 71 toward one axial side onto the hooked portion 73, thereby holding the recessed portion 61 and the protruding portion 62 in a disengaged state. From this state, an operator 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.

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 circumferential position of the female protrusion 4 and the circumferential position of the male protrusion 5 coincide. This allows the operator to easily determine that the male thread 33 of the male part 3 has been tightened to the tightening completion position. Furthermore, because the flexible portion 71, hooking portion 72, and hooked portion 73 are each formed from 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.

By forming a slit 44 in the female protrusion 4, the flexible portion 71, hooking portion 72, and hooked portion 73 are each formed, making it easy to form each of the portions 71-73 of the disengagement mechanism 7 on the female protrusion 4.

[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 engaging portion is a recess 61 and the second engaging portion is a protrusion 62, but the first engaging portion may be a protrusion and the second engaging 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.

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.

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

1 Pipe joint 2 Female part 3 Male part 4 Female protrusion (first protrusion)
5 Male protrusion (second protrusion)
6 Locking mechanism 25 Female thread 33 Male thread 43 Protruding end surface 44 Facing slit 61 Recess (first engagement portion)
62 convex portion (second engagement portion)
71 Flexible portion 72 Hooking portion 73 Hooked portion 91 First hose (first piping)
92 First hose (other piping)

Claims (3)

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. 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. 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.