JP4404413B2 - Pipe fitting - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe joint including a plug and a socket suitable for connecting a pipe for passing a high-pressure fluid or a high-pressure hose, and in particular, a valve body is built in each of the fluid passages of the socket and the plug, and the connection is not established. In the state, each valve body abuts on the valve seat provided in the fluid passage by the spring force of the spring to close the fluid passage, and at the time of connection, each valve body presses against each other and separates from the valve seat to open the fluid passage. It relates to pipe joints.
[0002]
[Prior art]
Conventionally, as this type of pipe joint, for example, there is one disclosed in Japanese Patent Publication No. 59-32711. This conventional pipe joint is composed of a plug (described as a nipple in the publication) and a socket (also described as a coupler), and the plug is contacted by the spring force of the valve seat. A first valve body that contacts and closes the fluid passage is built in, and a small-diameter valve body (also described as a bleeder) is movable in the axial direction in a through hole formed in the axial center of the first valve body. The built-in small-diameter valve body is biased by a spring so that the front end of the small-diameter valve body protrudes from the front end of the first valve body and abuts against a valve seat provided in the through hole. On the other hand, the socket incorporates a second valve body that abuts the valve seat by the spring force of the spring and closes the fluid passage. When connecting the plug and the socket, the front end of the small-diameter valve body of the plug is pushed by the front end of the second valve body of the socket, and thereby, around the small-diameter valve body, that is, the through hole of the first valve body and the small-diameter valve A fluid passage is formed between the body and the fluid remaining in the plug through the fluid passage instantaneously and the internal pressure is reduced. For this reason, even when an internal pressure is applied when connecting the socket and the plug, the plug and the socket can be connected manually.
[0003]
[Problems to be solved by the invention]
However, in the above conventional example, the small-diameter valve element is a solid member, and the small-diameter valve element is pressed against the valve seat by receiving the spring force of the spring and the pressure of the fluid remaining in the plug. Therefore, the higher the fluid pressure, the greater the force required to push the small diameter valve body away from the valve seat and open the fluid passage. Therefore, if the pressure of the remaining fluid becomes so high that it cannot be pushed by human power, the outer diameter of the small diameter valve body must be reduced in order to reduce the force pushing the small diameter valve body. As a result, the passage cross-sectional area of the fluid passage that can be formed around the small-diameter valve element is reduced by the reduced outer diameter, and it takes a long time for the fluid remaining inside to escape when the pipe joint is connected manually. . Therefore, the larger the size of the pipe joint, that is, the larger the diameter of the pipe joint, the larger the amount of fluid remaining inside, so that the fluid remaining inside escapes through the fluid passage having a small passage cross-sectional area. It takes a long time, and when connecting the pipe joints manually, the worker has to keep applying the force for a long time. Therefore, the pipe joint according to the conventional example has a problem that it is difficult to apply as the pressure of the fluid used increases or as the size of the pipe joint increases. The present invention has been made in view of such conventional problems, and the problem is that it is easily connected even when an internal pressure is applied without being affected by the height of fluid pressure or the size of a pipe joint. It is possible to provide a pipe joint that can increase the degree of design freedom.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, according to the first aspect of the present invention, valve bodies are respectively built in the fluid passages of the socket and the plug, and in a non-connected state, each valve body has an elastic spring on a valve seat provided in the fluid passage. It abuts to close the fluid passage in Hatsuryoku, a pipe joint to open the fluid passage away from jostling valve seat together, each of the valve body at the time of connection, to one of the valve body of the said socket plug , to form a center hole of closing the rear end opening in the distal end side in the center axis direction, and said fluid passage and said central bore to form a first communicating passage communicating the axial direction in the central bore An auxiliary valve body that is movably fitted to the valve body, and a spring that biases the auxiliary valve body in the distal direction and projects the distal end portion from the distal end of the valve body. A gap between the surface and the front outer peripheral surface of the auxiliary valve body Is formed, further, the and the auxiliary valve body tip the valve body tip the valve body is located in the longitudinal axial direction of the first communication passage formed in the valve body when in the state of protruding from the auxiliary a pair of seal rings respectively seal between the valve body is provided, the sealing by the seal ring at the front side of the first communication path of the pair of seal rings when the auxiliary valve body is retracted is released, the valve body and the can with the first communication path and the gap formed between the auxiliary valve body is configured to communicate, also the tip portion of the valve body, flowing distally through the gap A second communication path for allowing fluid to pass from the inside to the outside of the valve body is provided .
With this configuration, when connecting the socket and the plug, retracting the socket with one of the valve body tip auxiliary valve body by pushing the tip of the protruding auxiliary valve body at the tip of the other of the valve body from the plug by the unwound sealing by the seal ring at the front side of the pair of seal rings disposed between one of the valve body and the auxiliary valve body, between the auxiliary valve body and the one of the valve body a through the communication and the gap and the first communication passage formed, flowing the through the gap fluid remaining in the fluid passage between the first communicating path of one of the valve body to the inside the other valve body. As a result, the pressure of the fluid pressing the one valve body in the direction of closing the fluid passage rapidly decreases. At this time, the auxiliary valve body, because the space between said pair of sealing rings provided on the periphery thereof in communication with the fluid passage through the first communication path, the fluid in which the pair of seal rings remains mutually opposite axial forces subjected, i.e., the tip with a constant pressing force is the resultant force of the axial force having a magnitude corresponding to the difference between the sealing diameter of said pair of seal rings, and resilient force of the spring Pushed in the direction. Therefore, the auxiliary valve body is not pressed on the valve seat side upon receiving the pressure (internal pressure) of the fluid remaining as small valve body of the prior art. Therefore, when using a high fluid enough to pressure of the fluid remaining is not pressed in by human power, or even when the size of the pipe joint is large, as in the small-diameter valve of the prior art, the valve seat and the auxiliary valve body it is not necessary to reduce the outer diameter of the auxiliary valve body in order to reduce the force to push to the side, the outer diameter of the auxiliary valve body, is freely determined that without being influenced by the size of the pressure and pipe fittings of the fluid it can. Further, even if the size of the pipe joint is large, it is not necessary to reduce the outer diameter of the auxiliary valve body, not the time required for the fluid remaining inside as described above prior art comes off long, by human power When connecting the pipe joint, the operator does not need to continue to apply force for a long time, and even when the internal pressure is applied, the connection can be easily made and the workability is good. Further, by making the seal diameter of the pair of sealing rings can be set to any value the valve opening pressure of the auxiliary valve body in accordance with the difference between the sealing diameter.
In addition, since the second communication passage through which the fluid flowing from the inner side to the outer side of the valve body passes from the inner side to the outer side of the valve body is provided at the distal end portion of the one valve body, the second valve body is provided. The tip of the auxiliary valve body is pushed by the tip of the other valve body so that the two valve bodies are in close contact with each other, and the gap formed between the valve body and the auxiliary valve body is closed. However, the fluid pressure remaining in one of the socket and the plug flows from the inside to the outside of the one valve body through the first communication path, the gap, and the second communication path. When the socket and the plug are connected, the internal pressure can be reliably reduced.
[0005]
According to a second aspect of the present invention, in the pair of seal rings that seal the space between the valve body and the auxiliary valve body, the front end side of the seal ring on the rear end side of the valve body is provided. The seal ring has a large seal diameter .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing an example of an embodiment of a pipe joint according to the present invention, and is a longitudinal cross-sectional view enlarging a part of FIG. 3, FIG. 2 is a quadrant vertical cross-sectional view showing a pipe joint in a disconnected state, FIG. 3 is a quadrant vertical sectional view showing the pipe joint in the middle of connection, and FIG. 4 is a quadrant vertical cross sectional view showing the pipe joint in the connection completed state.
As shown in FIG. 2, the pipe joint according to this example includes a cylindrical socket 1 having an insertion port 19 at the tip, and a cylindrical plug 2 that is inserted into and connected to the socket 1 from the insertion port. Become. In this pipe joint, the valve bodies 5 and 6 are built in the fluid passages 3 and 4 of the socket 1 and the plug 2, and the valve bodies 5 and 6 are provided in the fluid passages 3 and 4, respectively, in a disconnected state. The fluid passages 3 and 4 are closed by contact with the valve seats 7 and 8 by the elastic force of the springs 9 and 10, and the tips of the respective valve bodies 5 and 6 are pressed against each other and separated from the valve seats 7 and 8 when connected. The fluid passages 3 and 4 are opened.
[0007]
On the rear end side of the socket 1, a connecting portion 11 that is screwed to a pipe or the like is formed. Further, a valve claw 15 having a plurality of flow holes 12 and a guide cylinder portion 14 into which the shaft portion 13 of the valve body 5 is slidably fitted is disposed in the middle of the fluid passage 3 of the socket 1. The valve pawl 15 is fixed and secured by a stop ring 16 provided on the inner peripheral surface of the socket 1. A spring 9 is provided between the valve claw 15 and the valve body 5 to urge the valve body 5 in the distal direction so as to contact the valve seat 7. Further, a seal member 17 composed of an O-ring and a backup ring for sealing between the inner peripheral surface and the outer peripheral surface on the tip end side of the plug 2 is provided on the inner peripheral surface of the insertion port 1 a of the socket 1.
[0008]
The outer periphery of the socket 1 is slidable between a lock position (position shown in FIG. 4) for locking the socket 1 and the plug 2 and a lock release position (position shown in FIG. 3) for releasing the lock. A sleeve 18 is fitted. That is, a plurality of lock ball fitting holes 19 are formed at substantially equal intervals in the circumferential direction at the distal end portion of the socket 1, and the lock balls 20 are fitted in the fitting holes 19 so as to be able to appear and retract.
[0009]
A pressing portion 22 that presses the lock ball 20 in the centripetal direction and a release portion 23 that allows the lock ball 20 to move in the centrifugal direction are formed on the inner peripheral surface of the distal end portion of the sleeve 18. The sleeve 18 is urged by a spring 24 toward the lock position where the pressing portion 22 presses the lock ball 20 in the centripetal direction. At this position, the distal end of the sleeve 18 abuts against a stopper 25 that also serves as a stopper, and movement in the distal direction is restricted. In this state, when the sleeve 18 is moved from the lock position shown in FIG. 2 to the left in the drawing against the elastic force of the spring 24, the lock ball 20 is released from the pressing by the pressing portion 22 and moves in the centrifugal direction. Therefore, when the plug 2 is inserted into the tip insertion opening 1a of the socket 1, the lock ball 20 engages with the lock ball engaging groove 21 formed on the outer periphery of the plug 2, and the socket 1 and the plug 2 is fixedly connected.
[0010]
On the other hand, in the plug 2, a connecting portion 26 that is screw-coupled to a pipe or the like is formed on the rear end side. A valve claw 29 having a plurality of flow holes 27 and a guide tube portion 28 for guiding the valve body 6 is disposed in the fluid passage 4 of the plug 2. The valve claw 29 is fixed and secured by a stop ring 30 provided on the inner peripheral surface of the plug 2. A spring 10 is interposed between the valve claw 29 and the valve body 6 to urge the valve body 6 in the distal direction so as to contact the valve seat 8.
[0011]
As shown in FIG. 1, the valve body 6 of the plug 2 is formed with a center hole 31 that opens at the front end side and closes the rear end side in the central axis direction. 4 a first communication passage 32 that communicates the is formed. That is, in this example, the valve body 6 is a valve in which a head portion 33a that has a through hole in an axial center portion and abuts on the valve seat 8 and a cylindrical portion 33b that extends from the head portion toward the rear end side are integrally formed. It consists of two members, a main body 33 and a cylindrical body 34 having a closed bottom part. The open end side of the cylindrical body 34 is fitted to the inner periphery of the cylindrical part of the valve main body 33, and the cylindrical part is caulked and integrated with the cylindrical body 34. It is. This integration may be screwed or brazed. Thus, the center hole 31 is formed by the through hole of the valve body 33 and the hole of the cylindrical body 34. Further, the first communication passage 32 is formed in the cylindrical portion 33b of the valve body 33. Further, the cylinder 34 of the valve body 6 is slidably fitted to the guide cylinder portion 28 of the valve claw 29. Thereby, the valve body 6 can move in the plug 2 in the axial direction straight.
[0012]
A cylindrical auxiliary valve body 35 is fitted in the center hole 31 of the valve body 6 so as to be movable in the axial direction, and the auxiliary valve body 35 is urged in the distal direction so that the distal end thereof is shown in FIG. As shown in FIG. 4, a spring 36 that protrudes from the tip of the valve body 6 is provided. Further, when the tip of the auxiliary valve body 35 protrudes from the tip of the valve body 6 on the outer periphery of the auxiliary valve body 35 (see FIG. 2), the shaft of the first communication hole 32 formed in the valve body 6 A pair of seal rings 37 and 38 are provided that are positioned in the front-rear direction and seal between the valve body 6 and the auxiliary valve body 35, respectively. Thus, in the non-connected state, the auxiliary valve body 35 has a space 47 between the pair of seal rings 37, 38 provided around the auxiliary valve body 35 and the fluid passage 4 through the first communication hole 32. The axial forces in opposite directions that the rings 37 and 38 receive by the fluid remaining in the fluid passage, that is, the axial force having a magnitude corresponding to the difference in seal diameter between the pair of seal rings 37 and 38, It is pushed in the direction of the tip by the resultant force of the elastic force.
[0013]
As shown in FIG. 2, the auxiliary valve body 35 has a valve closing position in which a tip portion protrudes from the tip of the valve body 6, and a valve opening position in which the auxiliary valve body 35 retreats against the elastic force of the spring 36 ( The position can be moved by a predetermined stroke. That is, the portion on the tip side from the central portion of the auxiliary valve body 35 is a small-diameter cylindrical portion having an outer diameter that fits with a small gap 45 in the small-diameter hole portion 39 that is the tip-side portion of the through hole 33a of the valve body 33. An annular protrusion 41 is formed at the center of the groove 40 to form a receiving groove for the seal ring 37. The rear end of the protrusion 41 slides in the cylindrical body 34. It is formed in the cylinder part 42 which fits freely.
[0014]
Further, when the auxiliary valve body 35 is retracted by a predetermined stroke to the position shown in FIG. 3 from the position shown in FIG. 2, the seal by the seal ring 37 at the front side of the first communication passage 32 of the pair of seal rings 37 and 38 is released, the valve body 6 and the gap 45 formed between the auxiliary valve body 35 and the first communicating passage 32 is configured to communicate (see FIG. 1). That is, in this example, when the auxiliary valve body 35 is in the closed position shown in FIG. 2, the medium diameter hole formed in the rear end side of the through hole of the valve body 33 with the seal ring 37 having a larger diameter than the small diameter hole portion 39. The annular projection 41 abuts on the stepped portion of the medium diameter hole 43 and the small diameter hole 39 and the auxiliary valve body 35 is positioned by this, so that the auxiliary valve body 35 is positioned. Is prevented from flowing out through the outer periphery of the auxiliary valve body 35. When the auxiliary valve body 35 is retracted by a predetermined stroke from the valve closing position shown in FIG. 2 to the valve opening position shown in FIG. 1, the seal ring 37 comes off from the inner peripheral surface of the medium diameter hole 43, and the medium diameter hole part 43 than located in the first communication passage 32 and communication with the large diameter portion 44 with a large diameter, whereby, through a gap 45 communicates formed between the valve body 6 and the auxiliary valve body 35, the fluid passage fluid within 4 is adapted to exit distally through the gap 45 of the first communication passage 32 and the auxiliary valve body 35.
[0015]
Further, the distal end portion of the valve body 6, the second communication path 46 for passing to the outside is provided a fluid flowing through the gap 45 from the inside of the valve body 6.
Further, the seal member 17 seals between the inner peripheral surface of the front end portion of the socket 1 and the outer peripheral surface of the front end portion of the plug 2 before the auxiliary valve body 35 moves back to the position shown in FIG. It is arranged at the position to do. Thus, fluid flowing through the gap 45 and the second communication passage 46 is prevented to leak out. Then, when going to insert the distal end portion of the plug 2 to the tip insertion port 1a of the socket 1, the first communication passage 32 and the gap 45 retracts the auxiliary valve body 35 is pushed by the valve body 5 of the socket 1 side At the same time or before the communication, the valve body 5 of the socket 1 is configured to open away from the valve seat 7 as shown in FIG. Thus, fluid flowing from second communicating path 46 through the gap 45 is made to flow into the fluid passage 3 side of the socket 1.
[0016]
When connecting the pipe joint according to this example having the above-described configuration, the sleeve 18 is moved to the left in the figure against the elastic force of the spring 24 from the lock position shown in FIG. When the distal end portion of the plug 2 is inserted into the distal end insertion port 1a, the distal end portion of the auxiliary valve body 35 protruding from the distal end of the valve body 6 of the plug 2 is pushed by the distal end of the valve body 5 of the socket 1 (see FIG. 1 (see FIG. 3), the seal which is retracted by a predetermined stroke from the position shown in FIG. 2 to the position shown in FIG. 1 and which is on the front side of the two seal rings 37 and 38 provided on the outer periphery of the auxiliary valve body 35 solved sealing by ring 37, the valve body 6 and the gap 45 formed between the auxiliary valve body 35 and the first communication hole passage 32 communicates. Thus, the fluid remaining in the fluid passage 4 of the plug 2 flows out to the first communication passage 32, the gap 45, and the second communication passage 46 through to the fluid passage 3 of the socket 1 is connected partner. As a result, the internal pressure applied when connecting the socket 1 and the plug 2, that is, the pressure of the fluid acting on the valve body 6 of the plug 2 in the direction of closing the fluid passage 4 rapidly decreases, and the valve body 6 As shown in FIG. 4, the valve is displaced to the valve opening position. As a result, the fluid passages 3 and 4 of the socket 1 and the plug 2 communicate with each other, and the sleeve 18 is moved by the urging force of the spring 24 in a state where the lock ball 20 is engaged with the lock ball engagement groove 21 of the plug 2. The lock ball 20 is pressed by the pressing portion 22 of the sleeve 18 to complete the connection.
[0017]
According to the pipe joint according to the present example having the above configuration, when connecting the socket 1 and the plug 2, the tip of the auxiliary valve body 35 protruding from the tip of the valve body 6 of the plug 2 is connected to the valve body 5 of the socket 1. When the auxiliary valve body 35 is retracted by a predetermined stroke from the position shown in FIG. 2 to the position shown in FIG. sealing by the seal ring 37 on the front side is released, communicates with a gap 45 formed in the first communicating passage 32 between the valve body 6 and the auxiliary valve body 35, the fluid remaining in the fluid passage 4 of the plug 2 , through the first communication passage 32 and the gap 45 flows out from the second communicating passage 46, it flows into the fluid passage 3 inside than the valve element 5 are opened in the other side. As a result, the pressure of the fluid pressing the valve body 6 in the direction of closing the fluid passage 4 rapidly decreases. At this time, the auxiliary valve body 35, since the space 47 between the pair of seal rings 37 and 38 provided on the periphery thereof in communication with the fluid passage 4 via the first communication path 32, a pair of seal rings 37, The axial forces opposite to each other, that is, the axial force having a magnitude corresponding to the difference in seal diameter between the pair of seal rings 37 and 38 (in this example, the direction of the seal ring 37 However, the seal diameter is larger than that of the seal ring 38 and is pushed in the distal direction by the resultant force of the spring 36 and the elastic force of the spring 36. For this reason, the auxiliary valve body 35 receives the pressure (internal pressure) of the remaining fluid over the entire diameter unlike the small-diameter valve body of the prior art and is not pressed to the valve seat side. Therefore, even when a fluid that is so high that the pressure of the remaining fluid cannot be pushed by human power is used, or when the size of the pipe joint is large, the auxiliary valve body 35 is made to be a valve seat like the small-diameter valve body of the prior art. It is not necessary to reduce the outer diameter of the auxiliary valve body 35 in order to reduce the pushing force to the side, and the outer diameter of the auxiliary valve body 35 can be freely determined without being influenced by the fluid pressure or the size of the pipe joint. . Further, even when the size of the pipe joint is large, it is not necessary to reduce the outer diameter of the auxiliary valve body 35. Therefore, unlike the prior art, the time required for the fluid remaining in the interior to escape does not increase, and human power is required. When connecting the pipe joint, the operator does not need to continue to apply force for a long time, and even when the internal pressure is applied, the connection can be easily made and the workability is good. Further, by making the seal diameters of the pair of seal rings 37 and 38 different, the valve opening pressure of the auxiliary valve body 35 can be set to an arbitrary value according to the difference in the seal diameter.
[0018]
Actually, the seal diameter of the seal ring 37 is larger than the seal diameter of the seal ring 38. As a result, the auxiliary valve body 35 is pushed toward the distal end side by the resultant force of the axially leading end side corresponding to the difference in seal diameter between the pair of seal rings 37 and 38 and the elastic force of the spring 36. Has been.
[0019]
Furthermore, according to the pipe joint according to the present example, the tip of the auxiliary valve body 35 on the plug 2 side and the tip of the valve body 6 are pushed by the tip of the valve body 5 on the socket 1 side so that both valve bodies 5, 6, even when the tip surface of the plug 6 is closed (the state shown in FIGS. 1 and 3), the fluid 45 remaining in the fluid passage 4 of the plug 2 can be formed around the first communication hole 32 and the auxiliary valve body 35, Further, since the fluid passage 3 on the socket 1 side passes through the second communication hole 46 provided in the radial direction, the internal pressure can be reliably reduced when the socket 1 and the plug 2 are connected.
[0020]
In addition, according to this example, since the auxiliary valve body 35 is formed in a cylindrical shape, when the valve body 35 moves in the axial direction, the volume change of the central hole 31 provided in the valve body 6 is prevented to assist. The malfunction of the valve body 35 can be prevented.
[0021]
In the pipe joint according to the above example, the auxiliary valve body 35 is provided in the center hole 31 formed in the valve body 6 of the plug 2, but when the internal pressure remains on the socket 1 side, the valve body 5 of the socket 1 is provided. By forming a central hole similar to the central hole 31 and providing a valve body similar to the auxiliary valve body 35 in the central hole, the same effect as the above example can be obtained.
[0022]
【The invention's effect】
As described above, according to the first aspect of the present invention, it is possible to easily connect even when an internal pressure is applied without being affected by the height of the fluid pressure and the size of the pipe joint, and the freedom of design. The degree can be expanded.
[0023]
According to the invention which concerns on Claim 2, when connecting a socket and a plug, an internal pressure can be reduced reliably.
[Brief description of the drawings]
FIG. 1 is a view showing an example of an embodiment of a pipe joint according to the present invention, and is an enlarged longitudinal sectional view of a part of FIG.
FIG. 2 is a longitudinal sectional view showing a pipe joint in a disconnected state.
FIG. 3 is a longitudinal sectional view showing a pipe joint in a state of being connected.
FIG. 4 is a longitudinal sectional view showing a pipe joint in a connection completed state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Socket 1a ... Insert port 2 ... Plug 3, 4 ... Fluid passage 5 , 6 ... Valve body 7, 8 ... Valve seat 9, 10 ... Spring 11, 26 ... Connection part 12, 27 ·················································································· 15 ·································································································································· ············································································································ ... Spring 25 ... ----- stopper 31 ......... central bore 32 ......... first communication path 33 ......... valve body 34 -----・ ・ ・ ・ Cylinder 35 ・ ・ ・ ・ ・ ・ ・ ・ ・ Auxiliary valve body 36 ・ ・ ・ ・ ・ ・ ・ ・ ・ Spring 37, 38 ・ ・ ・ ・ ・ ・ Seal ring 39 ・ ・ ・ ・ ・ ・ ・ ・・ Small-diameter hole 40 ・ ・ ・ ・ ・ ・ ・ ・ ・ Small-diameter cylindrical part 41 ・ ・ ・ ・ ・ ・ ・ ・ ・ Annular protrusion 42 ・ ・ ・ ・ ・ ・ ・ ・ ・ Cylinder part 43 ・ ・ ・ ・ ・ ・... in diameter portion 44 ......... large diameter hole portion 45 ......... gap 46 ......... second communication path 47 ... ······space

Claims (2)

Valve bodies are built in the fluid passages of the socket and the plug, respectively, and when not connected, each valve body abuts against the valve seat provided in the fluid passage by the spring force of the spring and closes the fluid passage. The valve bodies are pressed against each other and separated from the valve seat to open the fluid passage,
Either one of the valve body of the socket and the plug, to form a center hole of closing the rear end opening in the distal end side in the center axis direction, the communicating with said fluid passage and said central bore to form a first communication path,
Provided in the center hole is an auxiliary valve body that is movably fitted in the axial direction, and a spring that biases the auxiliary valve body in the distal direction to project the distal end portion from the distal end of the valve body, When the clearance is formed between the front inner peripheral surface of the valve body and the front outer peripheral surface of the auxiliary valve body, and the tip of the auxiliary valve body protrudes from the tip of the valve body, the valve body a pair of seal rings respectively seal between the formed with the first communication passage axially back and forth position to the valve body and the auxiliary valve body is provided, said pair of sealing when the auxiliary valve body is retracted sealing by the seal ring at the front side of the first communicating path of the ring is released, configured to the communication is with the first communication path and the clearance formed between the auxiliary valve body and the valve body ,
In addition, a pipe joint characterized in that a second communication passage is provided at the distal end portion of the valve body to allow fluid flowing from the inner side to the outer side of the valve body to flow through the gap . In the pair of seal rings that seal between the valve body and the auxiliary valve body, the seal diameter of the seal ring on the front end side is larger than the seal ring on the rear end side of the valve body. pipe joint according to claim 1, characterized in that a.

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