JPH0619909Y2 - Low temperature pipe fitting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a low temperature directional pipe joint, and more particularly to a pipe joint suitable for connection of pipes of low temperature fluid.

[Prior Art] It is an essential condition that a pipe joint for connecting fluid piping does not cause fluid leakage during use. As a pipe joint having this requirement, for example, one shown in FIG. 4 can be cited. A seal ring such as an O-ring 44 is provided in a necessary portion inside the pipe joint that has been used conventionally, and fluid leakage is prevented, and the sealing structure is enumerated. However, if it is limited to the pipe fitting adapted to the low temperature fluid, the structure is limited to the one using the rubber O-ring or the metal triangular ring, and for example, in the one shown in FIG. 4, the outer circumference of the plug is the O-ring. Only 44 seals the space between the socket 1 and the plug 2, which naturally limits the operating temperature.

[Problems to be Solved by the Invention] In the conventional pipe fittings described above, there are many types of materials for forming the plug and socket, but when used in extremely cold regions or at ultra-low temperatures, the outer peripheral surface of the plug is Since the O-ring to be sealed has a different shrinkage rate from that of a metal material, the cross section of the material shrinks or the diameter becomes smaller, resulting in a significant reduction in the sealing effect. There was a problem that I could not stand.

The present invention has been made in order to solve such problems, and a low-temperature pipe joint that can completely prevent fluid leakage even when used in ultra-low temperature fluid piping or in ultra-low temperature environment is provided. It is intended to be a proposal.

[Means for Solving the Problems] As a means for solving the above problems, the pipe joint according to the present invention is provided with an inclined surface provided on the inner peripheral surface of the operation sleeve attached to the outer peripheral surface portion of the socket, and is locked. A force is applied to press the plug and the socket through the ball in a direction in which the socket and the socket are always in close contact with each other, and a seal ring that seals the contact surface between the socket and the plug and the circumferential contact surface between the socket and the plug are provided. The seal ring for sealing is made of cold-resistant material.

The end face sealing seal ring has a U-shaped cross section with the opening facing the centripetal direction, and its side sealing surface is brought into contact with and fixed to a surface perpendicular to the axial center of the fluid passage of the socket, and the outer peripheral sealing ring is also sealed. Has a U-shaped cross section with the opening oriented in the axial direction, and its inner and outer peripheral sealing surfaces adopt a structure for sealing the socket inner peripheral surface and the plug outer peripheral surface of the groove. Further, in the seal ring for sealing the outer periphery, the outer peripheral collar provided on the bottom side of the opening is hermetically sandwiched between the constituent members of the socket, so that the seal ring can be reliably sealed against the difference in temperature shrinkage in the axial direction and the diametrical direction. Has been adopted.

[Operation] In the pipe joint of the present invention, the opening direction is different, but the sectional shape is U
By using two types of seal rings that form a letter, the end surface and the outer peripheral surface of the plug fitted into the socket are sealed, and the locking ball pressing surface of the slanted locking ball operated when connecting the socket and the plug locks the locking ball. The plug is always biased in the centripetal direction and transmitted to the wall surface of the trapezoidal circumferential groove of the plug through the locking ball of the biasing force, and the component force at that time presses the plug and the socket in the direction in which the plug and the socket are always in close contact with each other. The force that pushes the inside of the socket is always applied to the plug.

By constantly applying a pressing force to the plug in the axial direction in this way, the effect of the end face sealing primary seal ring is further improved, and the outer peripheral sealing secondary seal ring complements the primary seal ring. Also, considering that the contraction amount in the axial direction and the contraction amount in the diametrical direction are different depending on the low temperature, the secondary seal ring is hermetically sandwiched between the socket constituent members, so that the sealing performance of the seal ring is not deteriorated and the fluid Does not occur.

[Embodiment] FIG. 1 to FIG. 3 are half-cut sectional views showing an embodiment of the present invention in a double-way open / close type pipe joint.

Socket 1 and plug 2 shown in FIG. 1 separated from each other
Is a pair, and the socket 1 comprises a socket outer cylinder 5 having a joint 4 with the plug 2 and an adapter 6 screwed into the socket outer cylinder 5 to form a socket body 3. A fluid passage 7 is provided at the core, and a sliding valve 9 biased by a spring 8 is provided in the fluid passage 7. Further, the socket body 3 has an operation sleeve 11 axially biased by a compression spring 10 on the outer peripheral surface portion, and a locking ball 12 pressed by the inner peripheral surface of the operation sleeve 11.

The socket body 3 is made of a cold-resistant material such as aluminum or a fluororesin having a high breaking strength at a low temperature. The sliding valve 9 provided in the fluid passage 7 is also made of the same cold-resistant material as the socket body 3, and is formed in the same tubular shape to form the valve head.
A fluid through hole 14 is formed in the vicinity of 13 so as to face the centripetal direction. The sliding valve 9 has a valve pressing portion 15 projecting from the front surface thereof, and a valve head 13 formed in a substantially truncated cone shape comes into contact with and separates from a valve seat 16 provided on the inner peripheral surface of the fluid passage 7 of the socket body 3. When the socket 1 and the plug 2 are separated from each other, the valve seat 16 is strongly pressed to seal the fluid. This sliding valve 9 includes a spring seat 18 and a spring 8 which are mounted inside the socket body 3 by a stop ring 17.
Are mounted in the fluid passage 7 of the socket body 3 so as to be slidable in the axial direction.

The operation sleeve 11 is formed in a tubular shape, and an inclined surface 19 for pressing the locking ball 12 in the centripetal direction is provided over the entire circumference at the front open end portion on the inner peripheral surface side. This inclined surface 19 is made gentler than the inclination angle of the trapezoidal circumferential groove 20 of the plug 2 in order to increase the pressing force of the locking ball 12 in the centripetal direction and increase the pressing force of the plug 2 in the axial direction. It is better to do it. However, for easy understanding on the drawing,
Match the inclination angle of the inclined surface 19 with the inclination angle of the trapezoidal circumferential groove 20.
It is set to 45 °.

A large-diameter space 22 is provided in the other opening on the inner peripheral surface side of the operation sleeve 11 via a spring receiving step 21.
The compression spring 10 is installed in the
The locking ball 12 is pressed against the rear sloped surface 23 of the circumferential groove 20 of the plug 2 via 19. The operating sleeve 11 is a stopper fixed to the socket body 3 with a snap ring 24.
It is prevented from falling off by 25.

Further, the locking ball 12 has a larger diameter than conventional locking balls. That is, the diameter is larger than the sum of the depth of the tapered ball hole 26 penetrating the socket body 3 and the depth of the circumferential groove 20 of the plug 2, and as shown in FIG.
When the socket 1 and the plug 2 are in the connected state, the locking ball 12 is largely projected to the outer peripheral surface of the socket body 3 so that the locking ball 12 is sufficiently pressed by the inclined surface 19 of the operating sleeve 11.

27 is a seal ring with a U-shaped cross section and the opening is oriented in the centripetal direction, and 28 is a seal ring with a U-shaped cross section, but the opening is oriented in the axial direction. Both are made of fluororesin. It is a ring for sealing that has excellent cold resistance, chemical resistance, etc., and the seal ring 27 for sealing the end face is fitted in the fluid passage 14 of the socket body 3 with both side faces oriented in the axial direction, and both side faces are sealed. It is provided to act as a surface. Therefore, it is fixed to the socket body 3 by the collar 29 and the stop ring 30, and one side surface of the socket body 3 is in surface contact with the surface perpendicular to the axis provided in the fluid passage of the socket body 3. Further, the seal ring 28 for sealing the outer circumference is the socket body 3
Is to seal the inner peripheral surface of the plug 2 and the outer peripheral surface of the plug 2 respectively, and a flange portion 31 is provided on one end surface in the axial direction toward the centrifugal direction so that the outer peripheral surface makes surface contact with the inner wall surface of the socket body 3. The socket outer cylinder 5 and the adapter 6 tightly seal and sandwich.

The plug 2 has a fluid passage 33 and a sliding valve at the axial center of the plug body 32.
With 34. A sealed surface 35, which comes into surface contact with a seal ring 27 for sealing the end surface, is provided at the tip of the plug body 32 in a direction perpendicular to the axial center of the fluid passage. On the outer peripheral surface of the plug body 32, there are formed trapezoidal circumferential grooves 20 which are vertically symmetrical in FIG. The sliding valve 34 has a valve pressing portion 37 for pressing the sliding valve 9 on the socket 1 side on the front surface, and has a plurality of fluid passage holes 38 on the side surface, similar to the sliding valve 9, and a valve head portion 39. Is pressed in the axial direction by a spring seat 41 fixed by a stop ring 40 and a compression spring 42 to be pressed against the valve seat 43 to close the fluid passage of the plug body 325.

Next, the operation of the embodiment configured as described above will be described. When connecting the socket 1 and the plug 2, the operating sleeve 11 of the socket 1 is operated leftward in FIG. 1 against the compression spring 10 to apply a pressing force to the locking ball 12 obliquely in the centripetal direction. To release. Therefore, the plug 2 is attached to the joint 4 of the socket 1.
When the tip of the plug 2 is inserted, the tip outer peripheral surface of the socket 2 first comes into contact with the inner peripheral surface of the seal ring 28 for sealing the outer periphery, whereby the outer peripheral surface of the plug 2 is sealed by the seal ring 28. When the plug 2 is inserted further into the socket 1 in this state, the valve push portion 37 of the slide valve 34 comes into contact with the valve push portion 15 of the slide valve 9, and the slide valve 9 and the slide valve 34 are separated from each other. Pushing against each other and backing away from valve seats 16,43, socket 1 and plug 2
The fluid passages 14 and 38 are both electrically connected. The plug 2 is completely inserted into the socket 1, and the sealed surface 35 at the tip of the plug 2
Is released from the operating sleeve 11 when the end face sealing seal ring 27 comes into surface contact with the operating sleeve 11, the operating sleeve 11 is instantly moved forward by the elastic force of the compression spring 10,
The locking ball 12 is pressed in the centripetal direction by the inclined surface 19 provided on the inner peripheral surface of the front portion, and the locking ball 12 is engaged with the circumferential groove 20 of the plug 2. At this time, there is a gap between the inner peripheral inclined surface 45 of the socket 1 and the outer peripheral inclined surface 46 of the plug 2, and the locking ball 12 presses the rear inclined wall surface 23 of the circumferential groove 20 to move the plug 2 in the axial direction. , Push in the direction in which the plug 2 and the socket 1 are in close contact. In this way, the locking ball 12 on the socket side and the trapezoidal circumferential groove 20 on the plug side engage with each other, and the plug 2 can be completely fixed to the socket 1.

When the inclined surface 19 of the operation sleeve 11 presses the locking ball 12 when the socket 1 and the plug 2 are in contact with each other, the component of the pressing force is the rear inclined wall surface 23 of the circumferential groove 20 of the plug 2.
And acts so as to press the plug 2 and the socket 1 in a direction in which they are in close contact with each other. Therefore, the sealed surface 35 at the tip of the plug 2 always presses the side surface of the seal ring 27 for sealing the end surface from the axial direction with a constant force, and the seal ring 27 completely seals the end surface between the socket 1 and the plug 2. can do.

Next, when the outside air temperature is lowered or a low temperature fluid is caused to flow through the fluid passage in the above-mentioned connected state, the socket 1 and the plug 2 will contract as compared with the used state at room temperature. However, the compression spring 10 continues to maintain its resilience even at low temperatures, the inclined surface 19 of the operating sleeve 11 continues to push the locking ball 12 in the centripetal direction, and the locking ball 12 continues to push the plug 2 in the axial direction and the end surface. A perfect contact between the sealing ring 27 for sealing and the sealed surface 35 at the tip of the plug 2 is maintained invariably to completely prevent fluid leakage even during low temperature use. By the way, in this example, it was possible to adapt to the use of ultra-low temperature of -196 ° C.

On the other hand, even if the seal ring 28 for sealing the outer circumference provided on the wall surface of the socket 1 contracts in the diametrical direction at a low temperature, the inner peripheral surface of the seal ring 28 is always in close contact with the outer peripheral surface of the plug 2 and the fluid flows from the outer peripheral surface of the plug 2. Prevent leaks. Also, the seal ring 2
Since the outer peripheral brim 8 is hermetically sandwiched between the socket outer cylinder 5 and the adapter 6 which form a socket, the contraction amount in the axial direction is smaller than the dimensional ratio with respect to the contraction in the diametrical direction. Is complete, and no fluid leaks between the above-mentioned components.

In order to improve the sealing performance of each seal surface of the seal ring 27 for sealing the end face and the seal ring 28 for sealing the outer periphery, each U
Leaf springs can also be inserted in the openings of the V-shaped seal rings 27, 28.

[Effects of the Invention] As described above, this invention uses a seal ring having a U-shaped cross section but different in the direction of the opening for end face sealing and outer peripheral face sealing, and the former directs the opening in the centripetal direction. Is installed near the valve seat of the socket body, the latter is installed in the plug insertion part with the opening oriented in the axial direction, and is hermetically sandwiched between the socket constituent members, and the locking ball is pressed against the inner peripheral surface of the operating sleeve. The surface is formed as an inclined surface, and the component force of the force that presses the locking ball is made to act on the rear inclined wall surface of the trapezoidal circumferential groove provided on the outer peripheral surface of the plug through the locking ball, and the plug and socket are Since it is always pressed in the direction of close contact, one side of the seal ring
Not only does the other end seal between the plugs and the outer circumference between the socket and the plug, but when this pipe joint is used in an ultra-low temperature environment including low temperature fluid piping, the pipe joint material shrinks at low temperature. The plug constantly pressurizes the primary seal ring for end face sealing, and the elasticity of the seal ring can completely seal between the contact end faces of the socket and the plug. Even if it contracts in the diametrical direction, its inner peripheral surface is always in close contact with the outer peripheral surface of the plug to prevent fluid from leaking from the outer peripheral surface of the plug, and the outer peripheral flange of the secondary seal ring constitutes a socket outer cylinder. Since the amount of contraction in the axial direction is smaller than the dimensional ratio with respect to the contraction in the diameter direction, the amount of contraction is small and the sealing is complete, by sandwiching between the adapter and the adapter. Material between even there is an effect that can be completely sealed.

In addition, a collar is provided inside the adapter that constitutes the socket to form an insertion groove for the primary seal ring for end face sealing, and further an insertion groove for the secondary seal ring for outer peripheral sealing is formed by the locking ring. Therefore, the insertion groove can be easily formed, the parts can be easily processed, and the assembling can be easily performed.

[Brief description of drawings]

FIGS. 1, 2, and 3 show an embodiment of the present invention. FIG. 1 is a half-cut sectional view showing the socket and the plug separately, and FIG. 2 shows the socket and the plug connected. FIG. 3 is a half sectional view of the socket, and FIG. 3 is a vertical sectional side view of a socket main portion showing an enlarged mounting state of a seal ring for sealing an end face and a seal ring for sealing an outer periphery. It is a vertical section side view showing an opening-and-closing type pipe joint. 1 ... Socket, 2 ... Plug, 3 ... Socket body,
9,34 …… Sliding valve, 11 …… Operating sleeve, 12 …… Locking ball, 19 …… Inclined surface, 20 …… Outer peripheral groove, 27 …… Seal ring for end face sealing, 28 …… For outer peripheral sealing Seal ring,
32 …… Plug body, 35 …… Seal surface.

Claims (1)

[Scope of utility model registration request] 1. A pipe comprising a plug and a socket, wherein a locking ball of the socket is engaged with a trapezoidal circumferential groove on the outer periphery of the plug, and a sleeve urged in the axial direction by a compression spring is used for attaching and detaching the plug and the socket. In the joint, an inclined surface is formed on the inner peripheral surface of the front portion of the sleeve, and the locking ball is pressed in the centripetal direction in cooperation with the compression spring to be brought into contact with the rear inclined surface of the trapezoidal circumferential groove of the plug. The socket is constructed by urging the plug in a direction in which it is always in close contact with the socket side, and at the inner peripheral end of the socket, a primary seal ring for end face sealing having a U-shaped cross section with an opening in the centripetal direction. The adapter and the collar provided inside thereof are inserted into the circumferential groove and arranged, and further, the peripheral surface of the plug is provided between the primary seal ring and the locking ball position. A secondary seal ring for sealing the outer periphery, which has a U-shaped cross section and has an outer peripheral flange on the bottom side of the opening, is arranged with the opening oriented in the axial direction of the fluid passage, and the outer peripheral flange of the secondary seal ring constitutes the socket. The socket outer cylinder and the adapter are hermetically sandwiched, and the U-shaped cross section of the secondary seal ring is arranged in a circumferential groove formed by providing a locking ring between the secondary seal ring and the collar. And a low-temperature directional joint, wherein the primary and secondary seal rings are made of cold-resistant material.