JP2001082659A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety of a connecting state. SOLUTION: This pipe joint is constituted of a socket 1 fitting an operation sleeve 9 to hold a locking element 8 in the centripetal direction by advancing and to release it by retreating and a plug 2 forming an engagement groove 41, a valve body sliding hole 4 making a part of a fluid passage 15 is formed on the socket 1, a socket side valve body 18 of a cylindrical body to close the fluid passage 15 by advancing and to open it by retreating is fitted in the valve body sliding hole 4, a valve pressing rod 28 a rear end of which is fixed on the socket 1 and to make contact with and retreat a plug side valve body 21 at the time of connecting the socket 1 and the plug 2 to each otheris inserted in its inside, and the socket side valve body 18 is devised so that its head end surface 20 makes contact with a head end surface 22 of the plug side valve body 21 on a surface at the time of connection and its head end part outer periphery fits in a head end opening part 19 of the plug 2 in accordance with the plug side valve body 21 to retreat. A pin 34 is projectively provided on a rear end part of the socket side valve body 18, the fluid passage 15 is opened by retreating the socket side valve body 18 by operation of this pin 34, and retreat of the operation sleeve 9 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a socket provided with a locking member at a distal end thereof and provided with a locking operation sleeve for advancing on the outer periphery, pressing the locking member in a centripetal direction and retreating to release the locking member. The present invention relates to a pipe joint comprising a plug having an engagement groove formed at a distal end thereof with which the locking element is engaged, wherein the socket and the plug each include a valve body which moves forward to close and retreat and open a fluid passage.

[0002]

2. Description of the Related Art FIG. 11 is a longitudinal sectional view of a conventional pipe joint of this type. This fitting is a socket 50
The socket 50 has a lock ball 52 at the tip end thereof which can be retracted and retracted in the centrifugal direction. The outer periphery advances and presses the lock ball 52 in the centripetal direction to retreat and release. A lock operation sleeve 53 is provided, and a fluid passage 54 formed therein contains a valve body 56 which advances and abuts on a valve seat 55 to close and retreat and open the fluid passage 54. In the plug 51, an engagement groove 57 for engaging the lock ball 52 is formed on the outer periphery of the distal end portion thereof. A valve body 60 that closes and retreats and opens the passage 58 is incorporated. The valve bodies 56 and 60 of the socket 50 and the plug 51 are always urged in the forward direction by springs 61 and 62, respectively, and when not connected, the respective fluid passages 54 and 58 are closed. When the connection 51 is made, the respective valve bodies 56 and 60 press against each other and retreat to open the respective fluid passages 54 and 58.

[0003]

According to the above-described conventional pipe joint, when the socket 50 and the plug 51 are in a connected state, careless operation of the operating sleeve 53 causes the socket 50 to be inadvertently operated.
And the plug 51 may be separated, and care must be taken in how to use it. Further, as shown in the drawing, there is a gap S between the valve body 56 of the socket 50 and the valve body 60 of the plug 51 and the valve body 60 of the plug 51 and the valve seat 55 of the socket 50 and the valve seat 59 of the plug 51 which are in a butted state in the connected state. When the socket 50 and the plug 51 are separated from each other,
Is not returned to the fluid passages 54 and 58 but leaks to the outside.

[0004] It is an object of the present invention to provide a pipe joint capable of preventing inadvertent separation of a socket and a plug and preventing leakage of fluid when the socket and the plug are separated.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a locking element at a tip end, and moves forward on the outer periphery to hold the locking element in a centripetal direction and retreat to release the locking element. A socket having a locking operation sleeve to be locked, and a plug having an engagement groove at the tip end for engaging the locking element. The socket and the plug respectively advance to close the fluid passage and retreat and open. A pipe fitting with a built-in valve body,
In the socket, a socket body base having the plug insertion hole and a valve body sliding hole communicating with the plug insertion hole at a tip end side, and a socket body cylinder portion continuously provided at a rear end of the socket body base. A fluid passage having one end opened to the inner wall of the valve body sliding hole and the other end opened to the other wall outside the valve body sliding hole; and an opening opened to the inner wall of the communicating hole in the valve body sliding hole. The socket-side valve body, which is formed with a portion on the front side of the portion and opens and closes this fluid passage, has a tip end outer periphery slidably fitted in the tip end opening of the plug, and the tip end has a plug-side valve body. Of a communication hole which is slidably fitted in the valve body sliding hole, advances and opens in the valve body sliding hole. The opening is closed and retracted to open, and is always urged forward by a spring. And, inside the socket-side valve body made of the cylindrical body, a rear end thereof is fixed to the socket body cylindrical portion, and a valve pushing rod that comes into contact with the plug-side valve body and retracts when the socket and the plug are connected. Is inserted through the socket side valve body in a liquid-tight manner and the socket side valve body is slidable,
Further, a guide / lock hole including a guide hole formed in an axial direction and a lock hole formed in a circumferential direction from a rear end side of the guide hole communicates with the socket body cylinder and the operation sleeve. A valve sliding member is formed at the rear end of the socket-side valve body and penetrates the guide / lock hole. The valve sliding member is moved to the rear end according to the guide hole. The socket-side valve element is retracted to open an opening that opens to the valve element slide hole, and the valve slide member that has been moved to the rear end side of the guide hole is further moved according to the lock hole. It is characterized in that the operation sleeve is held at a retracted position and is prevented from retracting.

With this configuration, the operation sleeve is retracted to release the lock, and the plug is inserted into the plug insertion hole of the socket. When the engagement groove of the plug reaches below the lock, the lock is released. The socket and the plug are connected by engaging with the engagement groove, advancing the retracted operation sleeve in this state, and pressing the lock in the centripetal direction.

In the process of connecting the socket and the plug, the plug-side valve body comes into contact with the valve pushing rod of the socket and the front end surface of the plug fitting portion provided at the front end of the socket-side valve body, and the plug-side valve body is moved. The plug is retracted by being pushed by the valve pushing rod of the socket, and the plug fitting portion of the socket-side valve is brought into contact with the distal end of the plug-side valve in contact with the plug-side valve. It is inserted into the plug through the opening at the tip, and the connection is completed. In this connection state, the plug fitting portion of the socket-side valve body is fitted into the opening at the tip of the plug in a state of contact with the plug-side valve body, so that the socket-side valve body and the plug-side valve body Are connected with no gap between them.

From this connection state, when the socket-side valve is retracted in accordance with the guide hole of the guide and lock hole against the urging force of the valve slide member spring provided at the rear end of the socket-side valve, the socket-side valve is retracted. The opening of the communication hole that opens to the valve body sliding hole is opened. Thereby, the fluid passage of the socket communicates with the fluid passage of the plug.

Further, when the valve sliding member retreated according to the guide hole is moved in the circumferential direction according to the lock hole, the valve sliding member is prevented from advancing by the lock hole on the socket body cylinder side, whereby the socket is prevented from moving forward. The retracted state of the side valve body is maintained, and the operation sleeve in the advanced position is prevented from retreating by the valve sliding member located in the lock hole on the operation sleeve side, and the locked state of the locking element is maintained.

When the socket and the plug are separated from the above state, the valve sliding member located in the lock hole is moved according to the guide hole. As a result, the unlocked socket-side valve body is urged by the spring to move forward, and closes the socket-side fluid passage by closing the opening of the communication hole that opens to the valve body sliding hole, and closes the distal end thereof. The plug fitting portion has a fitting at the tip opening portion of the plug, and the tip portion abuts on the tip portion of the retreated plug-side valve body. By the fitting of the plug fitting portion into the opening at the distal end of the plug, the fluid at the distal end of the fluid passage of the socket is pushed into the fluid passage of the plug.

In this state, the operating sleeve, which has been prevented from being retracted by the valve sliding member, is retracted,
The lock in the centripetal direction of the locking element engaged in the engagement groove of the plug is released, and the socket and the plug can be separated. In the process of this separation, the lock was fitted to the opening at the tip of the plug. The plug fitting part of the socket-side valve element comes out of the plug, and the plug-side valve element released from the pressing by the valve pressing rod moves forward and closes the fluid passage of the plug. There is no risk of leakage.

[0012]

1 to 10 show an embodiment of a pipe joint according to the present invention. FIG. 1 is a plan view showing a state before connection of the pipe joint of this embodiment, and FIG. Is AA in FIG.
3 is a plan view showing a state after connection of the pipe joint of the present embodiment, FIG. 4 is a plan view showing a state in which an operation handle is removed in FIG. 3, and FIG. 5 is a sectional view taken along line BB of FIG. FIG. 6 and FIG.
FIG. 7 is a cross-sectional view taken along the line C, FIG. 7 is a plan view showing a state in which the valve sliding member is moved backward in the circumferential direction by the operation handle in FIG.
7 is a plan view showing a state where the operation handle is removed in FIG. 7, FIG. 9 is a sectional view taken along line DD of FIG. 7, and FIG. 10 is a sectional view taken along line EE of FIG.

In FIG. 1, reference numeral 1 denotes a socket, and 2 denotes a plug. In the socket 1, a socket body base 5 having a plug insertion hole 3 for inserting the plug 2 at the tip end thereof and a valve body sliding hole 4 communicating therewith, and a rear end of the socket body base 5 And a socket body tube portion 6 provided continuously.

A plurality of tapered through-holes 7 are formed in a circumferential direction at the tip end of the socket 1 where the plug insertion hole 3 is formed, and a locker 8 is provided in the tapered through-hole 7 with a centrifugal centrifugal direction. Are fitted so that they can come and go. In this embodiment, a lock ball is used as the lock 8.

Reference numeral 9 denotes an operation sleeve slidably fitted on the outer periphery of the socket 1, which moves forward to hold the lock 8 in the centripetal direction, and retreats to release the hold of the lock 8. I have. Reference numeral 10 denotes a lock presser formed on the inner peripheral surface of the operation sleeve 9, reference numeral 11 denotes a spring for urging the operation sleeve 9 in the forward direction, and reference numeral 12 denotes the advanced operation sleeve 9.
This is a stopper for restricting the lock member holding portion 10 to be positioned above the lock member 8 and preventing the operation sleeve 9 from coming off.

The valve body slide hole 4 is formed to have a smaller diameter than the plug insertion hole 3. The socket body base 5 having the valve body slide hole 4 is formed with a communication hole 13 having one end opened to the inner wall of the valve body slide hole 4 and the other end opened to the outer peripheral surface of the socket body base 5. The fluid passage 15 of the socket 1 is formed by the communicating hole 13 and a portion of the valve sliding hole 4 which is provided in the inner wall of the valve sliding hole 4 and is located before the opening 14 of the communicating hole 13. .

A pipe or hose or the like (not shown) is connected to an opening 16 opened on the outer peripheral surface of the socket body base 5, and the operation sleeve 9 is connected to the pipe or hose or the like. Are formed, and an elongated hole 17 is formed to allow the operation sleeve 9 to move forward and backward.

Reference numeral 18 denotes a socket-side valve body which is slidably fitted in the valve body slide hole 4 and opens and closes the fluid passage 15. The socket-side valve body has an outer peripheral surface which is in the forward position when in the forward position. The opening 14 opened on the inner wall of the valve body sliding hole 4 is closed and retracted to open.

The socket-side valve element 18 has a small-diameter distal end, and its outer periphery is slidably fitted in the distal-end opening 19 of the plug 2, and the distal end surface 20 has a plug-side valve element 2.
1 has a plug fitting part 23 formed in a shape capable of surface contact with the front end face 22, and when the socket side valve element 18 is in the forward position, the plug fitting part 23 is in the valve element sliding hole 4. From the plug insertion hole 3.

Reference numeral 24 denotes a flange portion provided at the rear end portion of the socket-side valve element 18, which is movably fitted in the socket main body cylindrical portion 6, and which is provided with a valve slide described later provided on the flange portion. The moving member comes into contact with one end of a guide hole, which will be described later, so as to regulate the advance position of the socket-side valve element 18. However, it is not necessary to be limited to this.

Numerals 25 and 26 are located on both sides of the opening 14 when the socket-side valve element 18 is in the forward position, and seal between the inner wall of the valve element sliding hole 4 and the outer peripheral surface of the socket-side valve element 18. It is a seal ring. Reference numeral 27 denotes a spring interposed between the socket main body cylinder 6 and the flange 24 for urging the socket-side valve element 18 in the forward direction.

Reference numeral 28 denotes a valve push rod inserted into the socket-side valve element 18 formed of the cylindrical body, and a rear end thereof is fixed to the socket main body cylindrical portion 6 so that the socket 1 and the plug 2 can be connected. The distal end is urged in the forward direction by a spring 29 to close the distal end opening 19, abut on the plug-side valve element 21 closing the fluid passage 30, and retreat.
Side fluid passage 30 is opened.

The distal end of the valve pressing rod 28 is the socket-side valve element 1.
When the plug 2 is inserted into the plug insertion hole 3 of the socket 1 at a position retracted from the distal end of the socket 8, the plug 2 does not come into contact with the plug-side valve 20 of the plug 1 at least before the distal end surface 20 of the socket-side valve 18. In position.

Reference numeral 31 denotes a seal ring for sealing between the outer peripheral surface of the valve pushing rod 28 and the inner peripheral surface of the socket-side valve element 18.

Reference numerals 32 and 33 denote guide and lock holes formed so as to communicate with the socket body cylinder 6 and the operation sleeve 9, respectively. Reference numeral 32 denotes a guide and lock hole formed on the socket body cylinder 6 side. 33 is a guide / lock hole formed on the operation sleeve 9 side. The guide / lock holes 32, 33 are formed in the guide holes 32A, 33 formed in the axial direction.
A and a substantially L-shaped lock hole 32B, 33B formed in the circumferential direction from the rear end side of the guide hole 32A, 33A.

Numeral 34 designates a valve sliding member composed of a bolt 34A and a collar 34B protruding from a flange 24 provided at the rear end of the socket-side valve element 18. The valve sliding member 34 is It penetrates the guide and lock holes 32 and 33 and protrudes to the outside. When the valve sliding member 34 is retracted in accordance with the guide holes 32A and 33A, the socket-side valve element 18 is retracted, and the opening 16 of the communication hole 13 opening to the valve element sliding hole 4 is opened. 33A, which has been moved to the rear end side, is inserted into the lock holes 32B, 3B.
3B, the valve slide member 34 is prevented from moving forward by the lock hole 32B on the socket body cylinder 6 side,
As a result, the retracted state of the socket-side valve element 18 is maintained, and the retractable operation sleeve 9 is prevented by the valve sliding member 34 located in the lock hole 33B on the operation sleeve 9 side.

Reference numeral 35 denotes an operation handle for operating the valve sliding member 34. The operation handle 35 includes a cylindrical portion 36 provided on the outer periphery of the operation sleeve 9 so as to be slidable in the axial direction and rotatable in the circumferential direction, and a handle portion 37 provided at the rear end of the cylindrical portion 36. The guide 36 and the lock hole 3
2 and 33, the valve sliding member 34 projecting therefrom is fixed,
The valve sliding member 34 is moved by gripping the handle 37 and operating the operation handle 35.

Numeral 38 denotes a grip protruding from the socket body base 5 to hold down the socket 1 when the operation handle 35 is operated. The grip 38 penetrates through the operation sleeve 9 and the operation sleeve 9 advances.
An elongated hole 39 that allows retreat is formed. Reference numeral 40 denotes the inner peripheral surface of the plug insertion port 3 of the socket 1 and the plug insertion port 3
Is a seal ring for sealing between the plug 2 and the outer peripheral surface of the plug 2 inserted into the plug. Reference numeral 41 denotes an engagement groove formed on the outer periphery of the tip of the plug 2.

Next, the socket 1 configured as described above
The operation of connecting and disconnecting the plug 2 and the plug 2 will be described.

First, before the connection, the socket 1 closes the opening 14 of the communication hole 13 which is opened to the valve body sliding hole 4 when the socket-side valve body 18 is urged by the spring 27 and is in the forward position. In a closed state, that is, in a state in which the fluid passage 15 is closed, the valve sliding member 34 protruding from the flange portion 24 provided at the rear end of the socket-side valve body 18 is connected to the socket body cylindrical portion 6 and the operating sleeve 9. Guide holes 32A, 33A of guide / lock holes 32, 33 formed to communicate with
The operating sleeve 9 is biased by a spring 11 to be in an advanced position, and the lock 8
In the centripetal direction. On the other hand, in the plug 2, the plug-side valve body 21 is urged by the spring 29 to move forward, closing the opening 19 at the distal end of the plug 2 and closing the fluid passage 30 (FIG. 2).

In this state, the operation sleeve 9 is retracted to release the lock 8. The retreat of the operation sleeve 9 at this time is caused by the long holes 17 and 3 formed in the operation sleeve 9.
9 and the guide / lock hole 33, without being hindered by a pipe or a hose (not shown), a grip 39, or a valve sliding member 34 connected to the opening 16 opened on the outer peripheral surface of the socket body base 5. I can do it.

When the lock 8 is released in this way,
The plug 2 is inserted into the plug insertion hole 3 of the socket 1. When the operating sleeve 9 which has been retracted is released when the engaging groove 41 of the plug 2 is located at the lock 8, the lock 8 is moved forward by the bias of the spring 11 and presses the lock 8 in the centripetal direction, whereby the lock 8 is moved. Engage with the engagement groove 41,
The socket 1 and the plug 2 are connected.

In the process of connecting the socket 1 and the plug 2, the plug-side valve 21 is brought into contact with the valve pushing rod 28 of the socket 1 and the tip end surface 20 of the plug fitting portion 23 provided at the tip of the socket-side valve 18. The plug-side valve body 21 is pressed by the valve pushing rod 28 of the socket 1 and retreats, but the distal end of the valve pushing rod 28 is retracted from the distal end of the socket-side valve body 18 and the plug of the socket 1 is inserted. When the plug 2 is inserted into the hole 3, the plug 2 is located at a position where it does not come into contact with the plug-side valve body 20 of the plug 1 at least before the distal end surface 20 of the socket-side valve body 18. Tip surface 2 of part 23
0 surely makes surface contact with the tip end surface 22 of the plug-side valve body 21,
With the retraction of the plug-side valve body 21, the socket-side valve body 18
Of the plug-side valve element 2
The plug 1 is fitted into the plug 2 from the distal end opening 19 of the plug 1 in a state of surface contact with the distal end surface 22 of the plug 1, and the connection is completed.
In this connection state, since the plug fitting portion 23 of the socket-side valve element 18 is fitted into the distal end opening 19 of the plug 2 in a state of being in surface contact with the plug-side valve element 21, the socket-side valve element 18 And the plug-side valve element 21 are connected without any gap (FIG. 5).

From this connection state, the operation handle 35
When the valve slide member 34 protruding from the flange portion 24 provided at the rear end portion of the socket-side valve element 18 is retracted in accordance with the guide holes 32A and 33A of the guide and lock holes 32 and 33, the socket side is operated. The valve element 18 retreats against the resilience of the spring 27 and opens the opening 14 of the communication hole 13 opening to the valve element sliding hole 4. Thereby, the fluid passage 15 of the socket 1 and the fluid passage 30 of the plug 2 communicate (FIG. 10).
At this time, the socket-side valve element 18 and the plug-side valve element 21
Since there is no gap between them, air is slightly mixed into the fluid flowing through the fluid passages 15 and 30 of the socket 1 and the plug 2 communicating with each other.

Further, the valve sliding member 34 retracted according to the guide holes 32A, 33A is inserted into the lock holes 32B, 33B.
When the valve sliding member 34 is moved in the circumferential direction, the forward movement of the valve sliding member 34 is prevented by the lock hole 32B on the socket body cylinder portion 6 side, whereby the retracted state of the socket side valve body 18 is maintained and the forward movement position is maintained. Operating sleeve 9
The retraction is prevented by the valve slide member 34 located in the lock hole 33B on the operation sleeve 9 side, and the locked state of the lock 8 is maintained (FIGS. 7, 8, and 9).

When the socket 1 and the plug 2 are separated from the above state, the valve sliding member 34 located in the lock holes 32B, 33B is moved according to the guide holes 32A, 33A. As a result, the unlocked socket-side valve element 18 is urged by the spring 27 to move forward, and closes the opening 14 of the communication hole 13 that opens to the valve element sliding hole 4, thereby opening the fluid passage 15 on the socket 1 side. And close
The plug fitting portion 23 at the distal end of the plug 2 fits into the distal opening 19 of the plug 2 and its distal end surface 20 comes into surface contact with the distal end surface 22 of the plug-side valve body 21 that is retracted (FIG. 5). The plug fitting portion 23 into the opening 19 at the tip end of the plug 2
By this, the fluid existing at the distal end side of the fluid passage 15 of the socket 1 is pushed into the fluid passage 30 of the plug 2.

In this state, the operating sleeve 9, which has been prevented from being retracted by the valve sliding member 34, is retracted so that the lock 8 engaged with the engaging groove 41 of the plug 2 in the centripetal direction. The presser is released, and the socket 1 and the plug 2 can be separated. In the process of this separation, the plug fitting portion 23 of the socket-side valve element 18 that has been fitted into the distal end opening 19 of the plug 2 becomes Then, the plug-side valve element 21 released from the pressing by the valve pressing rod 28 moves forward in conjunction with the plug fitting portion 23 to close the fluid passage 30 of the plug 2, so that the socket 1 and the plug 2 There is no danger of fluid leakage during separation.

[0038]

As described above, according to the pipe joint of the present invention, it is possible to prevent inadvertent separation of the socket and the plug, and to prevent leakage of fluid when the socket and the plug are separated. Can be.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state before connection showing an example of an embodiment of a pipe joint according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view showing a state after connection of the pipe joint of the present example.

FIG. 4 is a plan view showing a state where an operation handle is removed in FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 3;

FIG. 6 is a sectional view taken along line CC of FIG. 5;

FIG. 7 is a plan view showing a state in which the operation handle is retracted and then rotated in the circumferential direction in FIG. 3;

FIG. 8 is a plan view showing a state where an operation handle is removed in FIG. 7;

FIG. 9 is a sectional view taken along line DD of FIG. 7;

FIG. 10 is a sectional view taken along line EE of FIG. 9;

FIG. 11 is a longitudinal sectional view of a conventional pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Socket 2 Plug 3 Plug insertion port 4 Valve body sliding hole 5 Socket body base 6 Socket body cylinder 7 Tapered through hole 8 Locker 9 Operation sleeve 10 Locker holder 11 Spring 12 Stopper 13 Communication hole 14 Opening 15 Fluid Passageway 16 Opening 17 Elongated hole 18 Socket side valve element 19 Tip opening 20 Tip face 21 Plug side valve element 22 Tip face 23 Plug fitting part 24 Flange part 25 Seal ring 26 Seal ring 27 Spring 28 Valve pushing rod 29 Spring 30 Fluid passage 31 Seal ring 32 Guide / lock hole 32A Guide hole 32B Lock hole 33 Guide / lock hole 33A Guide hole 33B Lock hole 34 Valve sliding member 34A Bolt 34B Collar 35 Operation handle 36 Tube portion 37 Handle portion 38 Grip 39 Long hole 40 Seal Ning 41 engagement groove

Claims (1)

[Claims] 1. A socket having a locking element at a distal end thereof, a socket provided with a lock operation sleeve for advancing on the outer periphery, pressing the locking element in a centripetal direction and retreating to release the locking element, and the locking element at the distal end. Consisting of a plug formed with an engagement groove with which
The socket and the plug are pipe fittings each having a built-in valve body that moves forward to close a fluid passage and retreats and opens, wherein in the socket, the plug insertion hole and a valve body that communicates with the plug insertion hole at the tip end side. A socket body base having a sliding hole; and a socket body tubular portion connected to a rear end of the socket body base. The fluid passage has one end opened to the inner wall of the valve body sliding hole and the other end valved. The socket-side valve element, which is formed by a communication hole that opens on the other wall outside the body sliding hole and a portion of the valve body sliding hole that is on the front side of the opening that opens on the inner wall of the communication hole, and that opens and closes this fluid passage, An outer periphery of a distal end portion slidably fitted in a distal end opening portion of the plug, and the distal end portion is formed of a cylindrical body having a plug fitting portion capable of abutting against a distal end portion of a plug-side valve body; Slidingly fit into the valve body sliding hole, move forward and open in the valve body sliding hole. The opening of the communication hole is closed and retracted and opened, and is constantly urged in the forward direction by a spring.The rear end of the socket-side valve body made of the cylindrical body has a rear end. A valve pushing rod fixed to the socket body cylinder portion and abutting against the plug-side valve body when the socket and the plug are connected and retracting is inserted through the socket-side valve body in a liquid-tight manner and the socket-side valve body is slidably inserted. Further, a guide / lock hole including a guide hole formed in an axial direction and a lock hole formed in a circumferential direction from a rear end side of the guide hole communicates with the socket body cylinder and the operation sleeve. A valve sliding member is provided at the rear end of the socket-side valve body through the guide / lock hole, and the valve sliding member is moved to the rear end according to the guide hole. By the said socket The socket-side valve body is retracted by opening the opening that opens to the valve body sliding hole by retreating the side valve body and further moving the valve sliding member that has been moved to the rear end side of the guide hole according to the lock hole. Characterized in that the operation sleeve is held at a predetermined position and the operation sleeve is prevented from retreating.