JP2002327881A - Coupling for fluid piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coupling for fluid piping capable of quickly performing a connection by a simple operation at a field of construction work and having excellent sealing property and durability. SOLUTION: This coupling is constituted of a cylindrical female coupling 2 and a male coupling 6 fitted into the female coupling 2. A pair of splines 9 and 10 for coupling both of the couplings 2 and 6 in the peripheral direction and sealing members 21 and 23 for a fitting surface of the female coupling 2 and the male coupling 6 are provided on the fitting surface. The coupled female coupling 2 and male coupling 6 are fixed in the shaft direction by a stopper 15 fitted movably in the peripheral direction between facing inner peripheral groove 11 and outer peripheral groove 13 provided by crossing each spline 9 and 10 to form the coupling for fluid piping. As a result, the coupling for fluid piping with an excellent sealing property capable of quickly performing the connection by the simple operation without requiring a work taking labor and time such as welding at the field of the piping construction work and preventing leakage of fluid within a pipe and entering of water and dust from the outside can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pipe joint which can be connected quickly and has excellent sealing properties.

[0002]

2. Description of the Related Art As a conventional method of connecting various kinds of fluid pipes, generally, a pipe joint is connected directly by joining pipe ends or a flange provided at a connection end of pipes is connected with bolts and nuts. For example, a flange joint to be fastened is used.

[0003]

However, the method of connecting the pipe ends by directly butting the connection ends requires a laborious welding work at the construction site, and the method of connecting with the flange joint requires a plurality of pipes. Bolts and nuts must be fastened with a contact pressure higher than the fluid pressure in the piping,
Bad workability. In these connection methods, when the pipe connection section extends to a large number of places, a very laborious work is required, and when the pipe needs to be repaired, the pipe is cut or a large number of bolts and nuts are removed. Since it is necessary to remove the pipe, it is not easy to separate the pipe connection. Furthermore, in both the case of the welded joint and the flanged joint, the pipe ends are directly fixed to each other, so if uneven external force or repeated stress due to mechanical vibration acts on both sides of the connection, the connection Cracks can cause fluid leakage and eventually break.

It is an object of the present invention to provide a fluid pipe joint which can be quickly connected with a simple operation at a construction site, and has excellent sealing properties and durability.

[0005]

In order to solve the above-mentioned problems, the present invention employs the following configuration.

That is, a pair of splines for connecting the two joints in a circumferential direction to a fitting surface of the female joint and the male joint are formed by a cylindrical female joint and a male joint fitted to the cylindrical joint. A fluid pipe joint was formed by providing a seal member for sealing the mating surfaces, and a means for fixing the joined female joint and male joint in the axial direction.

[0007] In this way, the female joint and the male joint can be fitted to each other to connect and fix the metal pipe for the fluid piping. Connection can be performed quickly and easily without the need for nut fastening work. In addition, the sealing member on the fitting surface prevents leakage of fluid in the piping and intrusion of water and dust from the outside. it can.

Also, a cushion effect of absorbing the clearance in the radial direction and the circumferential direction of the fitting surface is obtained,
It is also effective in preventing damage to the pipe connection due to mechanical vibration of the pipe and thermal stress caused by a change in the pipe temperature.

Further, in the case where repair or the like becomes necessary, the pipe connection portion can be easily separated.

[0010] It is preferable that the seal member is mounted in annular grooves provided on fitting surfaces on both ends of the spline of the male joint.

With this configuration, the seal member attached to the annular groove provided in the fitting surface on the front side of the spline of the male joint in the fitting direction, that is, the fitting direction, prevents leakage of fluid in the piping. The seal attached to the attachment groove provided on the fitting surface on the rear side in the fitting direction can prevent intrusion of water and dust from the outside.

It is preferable that the seal member to be mounted in the annular groove on the front side in the fitting direction of the spline of the male joint is a lip packing.

[0013] The lip packing has a self-sealing action in which the fluid pressure acts on the fitting surface on the female spline side and is applied to the contact pressure. The contact pressure is applied to the entire side face of the packing with the increase of the working pressure. And the attachment to the fitting surface is simple. In addition, by properly selecting the interference, it is possible to maintain good sealing properties even with a fluid under reduced pressure such as vacuum transportation.

Preferably, a backup ring of the lip packing is mounted in the mounting groove.

By mounting the backup ring, the lip packing can be prevented from protruding into the gap between the fitting surfaces and being damaged.

Means for fixing the joint in the axial direction include an inner peripheral groove formed on the inner periphery of the female joint across the spline, the inner peripheral groove being deeper than the tooth groove, and the inner peripheral groove being opposed to the inner peripheral groove. An outer peripheral groove formed across the spline on the outer periphery of the male joint, and an arcuate shape movably fitted in an annular space formed by opposing the inner peripheral groove and the outer peripheral groove in the circumferential direction. And a stopper operating means for moving the stopper in the circumferential direction, a short tooth groove matching the spline of the female joint is formed on the inner surface of the stopper, and the stopper operating means is provided with the stopper Can be moved by at least a half pitch of the short tooth groove and fixed at a predetermined position.

In this way, the spline of the female spline joint and the short female spline of the stopper are brought into an inconsistent state only by moving the stopper in the circumferential direction by at least a half pitch of the female spline. ,
The two spline joints are mutually restrained in the pipe axis direction,
The escape is prevented.

It is preferable that the stopper is formed in an arc shape having a length of one third or less, and at least three stoppers are used in combination in a ring shape.

According to this configuration, the arc-shaped stopper can be easily fitted into the annular space and can be easily operated.

The stopper operating means can be formed by a long hole provided in the inner peripheral groove portion of the female spline joint, and a screw inserted through the long hole from the outside and screwed to the stopper.

In this way, the stopper is easily operated only by moving the screw along the long hole, and the spline of the female spline joint and the short female spline of the stopper are aligned or An unaligned state can be set, and the stopper can be fixed at a predetermined position by tightening the screw.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the joint for fluid piping of the first embodiment shown in FIGS. 1 to 4, the outer diameter of the end of the cylindrical female joint 2 is attached to the inner diameter of the end of one steel pipe 1 to be connected. The steel pipe 1 is fitted so that the end face thereof abuts against the engagement step 3 of the female joint (FIG. 2).
In this fitted state, the female joint 2 is
It is attached to the steel pipe 1. The other steel pipe 5 to be connected
In this case, the outer diameter surface of the cylindrical male joint 6 is fitted to the inner diameter surface of the end so that the end surface of the steel pipe 5 abuts against the upper surface of the flange 7 provided at the upper end of the male joint 6. In this fitting state, the male joint 6 is fixed by the welded portion 8 (see FIGS. 2A and 2B). The male and female joints 2 and 6 are mutually fitted in the pipe axis direction, and are fixed by joint fixing means described later, and the steel pipes 1 and 5 are connected.

On the inner peripheral surface of the female joint 2, splines of a fixed length, that is, female splines 9 are provided at a constant pitch in the circumferential direction. Further, on the outer peripheral surface of the male joint 6, a spline having a fixed length, that is, a male spline 10 is provided so as to be fitted to the female spline 9 and to connect the two joints 2 and 6 in a circumferential direction. .

On the inner periphery of the female joint 2, there is provided an inner peripheral groove 11 deeper than the tooth groove of the female spline 9, and a lower part of the inner peripheral surface is provided for receiving a lower end surface of the male joint 6. A step 12 is formed. On the outer periphery of the male joint 6, an outer peripheral groove 13 traversing the vicinity of the upper end of each male spline 10 is provided so as to face the inner peripheral groove 11. 7 is formed so as to protrude from the upper end surface of the female spline 9, and the distal end of the male joint 6 and the distal end of the male spline 10 are easily fitted to the female spline joint 2 and the female spline 9. Are provided with tapered portions 14 and 14a, respectively. By forming the receiving step portion 12 and the flange portion 7 of the male spline 10, the connection strength in the pipe axis direction and the pipe diameter direction can be increased.

When the male and female spline joints 2 and 6 are fitted, the inner peripheral groove 11 and the outer peripheral groove 13 form an annular space. An arc-shaped stopper 15 divided into three in the circumferential direction is fitted into this annular space so as to be movable in the circumferential direction. At the time of actual pipe connection, the stopper 15 is fitted in the inner peripheral groove 11 of the female joint 2 in advance, then the male joint 6 is fitted into the female joint 2, and the outer peripheral groove 13 faces the stopper 15.

The stopper 15 has, on its arc-shaped inner surface, short tooth grooves 9a corresponding to the female splines 9, and short teeth 9b matching the male splines 10 between the short tooth grooves 9a. Is provided and is moved in the circumferential direction in a state of being fitted in the inner circumferential groove 11, so that the short tooth groove 9 a is aligned with the female spline 9 of the female joint 2 and the short tooth groove 9 a in the circumferential direction. And the female spline 9 can be in an inconsistent state where they are shifted by a half pitch. In this misaligned state, the short teeth 9b match the male splines 10 of the fitted male joint 6.

In order to move the stoppers 15 in the circumferential direction, two slots 1 are provided for each stopper 15 at positions corresponding to the inner circumferential grooves 11 on the outer peripheral surface of the female joint 2.
6 are provided, and a screw 17 as a stopper operating means is screwed into each stopper 15 through the elongated hole 16.
The stopper 15 is provided by a tool engaging with the screw 17.
Can be moved in the circumferential direction. The slot 16 is
The stopper 15 is formed long enough to move the female spline 9 by a half pitch. By screwing the screw 17 into the screw hole 18 provided in the stopper 15, the stopper 15 can be fixed at a predetermined position.

The position of the slot 16 is indicated by the screw 1
7 (see FIG. 3), the female spline 9 is aligned with the short tooth groove 9a, and when it is at the left end in the figure (see FIG. 4),
The female spline 9 and the short tooth groove 9a are selected so as to be displaced by half a pitch and become out of alignment. Then, by positioning in this misaligned state, the short teeth 9b are aligned with the male splines 10, the elongated holes 16 are filled with the filler 19, and the male and female joints 2, 6 are fixed in the tube axis direction. You.

The male and female splines 9 and 10 of the male and female joints 2 and 6 have a rectangular cross-sectional shape. In addition, gear splines 9 and 10 shown in FIGS. 5 (a) and 5 (b) are used. 5 (c), a semi-circular spline as shown in FIG. 5 (d), an inverse tapered spline as shown in FIG. 5 (e), etc. be able to.

An annular groove 20 provided on the fitting surface of the male joint 6 in the tube axis direction, ie, on the front side in the fitting direction, is in contact with a lip packing made of nitrile rubber, ie, a U packing 21 and its heel. In addition, a backup ring 22 made of tetrafluoroethylene resin is mounted. The annular groove 20a provided in the circumferential direction on the fitting surface on the rear side in the fitting direction includes:
An O-ring 23 made of nitrile rubber is mounted.
The fitting surfaces of the male and female joints 2 and 6 are sealed by these seal members. As shown in FIG. 2B, the U-packing 21, the backup ring 22, and the O-ring 23 can be mounted in an annular groove provided on the fitting surface of the female joint 2 (from the second to the second described later). The same applies to the fourth embodiment.)

The male and female joints 2 and 6 can be formed of a metal such as an aluminum alloy or stainless steel.
The male and female joints 2 and 6 can be used not only for connecting steel pipes but also for connecting other metal pipes such as cast iron pipes, copper pipes, and copper alloy pipes.

The embodiment of the present invention is configured as described above, and its operation method and functions will be described below.

The female joint 2 and the male joint 6 are fitted to each other, and the stopper 15 is moved to a predetermined position along the elongated hole 16 by a tool engaged with the screw 17, and the screw 17 is moved to the stopper 15. The steel pipes 1 and 5 can be connected and fixed by a simple operation of being screwed into the provided screw hole 18. Therefore, the connection can be made quickly and easily at the piping work site without welding work or bolt and nut fastening work, and workability is remarkably improved.

Then, seal members, that is, a U-packing 21, a backup ring 22, and an O-ring 23 are attached to the annular grooves 20, 20a provided on the fitting surfaces on both ends of the male spline 10 of the male joint 6. Can prevent the leakage of fluid in the pipe and the intrusion of water and dust from the outside, so it can be used to transport liquids, gases, sludge, and other fluids under pressure or under reduced pressure It is.

In particular, a lip packing, that is, a U-packing 21 is used as a seal member to be mounted on the fitting surface on the front side in the fitting direction, and the backup ring 22 is mounted in contact with the heel portion thereof. It is possible to seal the pressure fluid well, and it is possible to prevent the seal from being damaged due to protrusion into the gap between the fitting surfaces of the male and female joints 2 and 6.

Furthermore, a cushion effect of absorbing the clearance in the radial direction and the circumferential direction of the fitting surface is obtained, and the pipe joint is cracked due to mechanical vibration of the pipe and thermal stress caused by a change in the pipe temperature. It is also effective in preventing damage.

FIGS. 6 and 7 show a second embodiment, in which a female joint 2 is attached to the end of one steel pipe 1 to be connected.
However, the piping configuration in which the male joint 6 is attached to the end of the other steel pipe 5 by the welds 4 and 8, respectively, is the same as in the above-described embodiment. The difference is the joint fixing means of the male and female joints 2 and 6. The joint fixing means in this case is as follows.

A male screw 24 is formed on the outer peripheral surface of the male joint 6, and a stopper 15a for preventing the male and female joints 2, 6 from coming off in the tube axis direction is formed in an annular shape, and the male screw 24 is formed on the inner peripheral surface thereof. Is formed. A short tooth groove 9a that matches with the female spline 9 is provided above the female screw 25 via an inner peripheral step 26.

In the same manner as described above, the annular groove 20 provided in the circumferential direction on the fitting surface on the front side in the fitting direction of the male joint 6 has:
A U-packing 21 made of nitrile rubber and a backup ring 22 made of tetrafluoroethylene resin are attached in contact with the heel.

The stopper 15a is screwed into the female joint 2, and the female spline 9 is aligned with the short tooth groove 9a while the inner peripheral step 26 is brought into contact with or close to the upper end surface of the female spline 9. Let it. In this state, the male joint 6 is aligned with the stopper 15a and the female spline 9 in the aligned state.
To the female spline 9
Is rotated by half a pitch of. As a result, the male and female spline joints 2, 6 are prevented from coming off in the tube axis direction and are fixed. And the attached U
The packing 21 prevents leakage of fluid in the piping,
Particularly when the fluid is a pressure fluid, the fitting surface is well sealed.

FIGS. 8 and 9 show a third embodiment, in which a female joint 2 is attached to one end of a steel pipe 1 to be connected by welding, and a male joint is attached to an end of the other steel pipe 5. The piping configuration in which 6 is attached by the welds 4 and 8, respectively, is the same as in the first and second embodiments. The difference is the joint fixing means of the male and female joints 2 and 6. The joint fixing means in this case is as follows.

A circumferential flange 2 is provided on the upper end of the outer peripheral surface of the female joint 6.
7 are formed. The stopper 15b is formed in a semicircular shape, and has a guide groove 28 provided on the inner surface thereof so as to be movably fitted to the flange 27. A short tooth groove 9a corresponding to each female spline 9 is formed at the upper part of the guide groove 28 following the upper end surface of the female spline 9, and a space between the short tooth groove 9a and the guide groove 28 is formed. Has an inner peripheral step 26
a is provided. A through hole 29 is provided in the guide groove 28 of the stopper 15b, and the screw 17 as a stopper operating means is inserted into the through hole 29. The screw 17 is screwed into a screw hole 30 provided in the flange 27.

In the same manner as described above, the annular groove 20 provided on the fitting surface on the front side in the fitting direction of the male joint 6 comes into contact with the U packing 21 made of nitrile rubber and the heel thereof,
Backup ring 22 made of tetrafluoroethylene resin
Is installed.

Each inner peripheral step 26a of the two semicircular stoppers 15b is placed on the upper end surface of the female joint 2 and is combined in an annular shape to align the female spline 9 and the short tooth groove 9a. Set to. Then, after the male joint 6 is fitted to the stopper 15b and the female joint 2 in the aligned state, and the stopper 15b is moved to the left or right by a half pitch of the female spline 9, the female spline 9 and the The tooth groove 9a is in an inconsistent state. Accordingly, the male and female joints 2, 6 are prevented from coming off in the tube axis direction, and the screw 17 is further tightened to fix the stopper 15b, thereby fixing the male and female joints 2, 6. The fitted surface is well sealed by the mounted U packing 21 and the backup ring 22, similarly to the case shown in FIGS. 8 and 9, particularly when the fluid in the pipe is a pressurized fluid.

The structure of the stopper for fixing the male and female joints 2 and 6 in the pipe axis direction to prevent the joints from coming off is not necessarily limited to the stoppers 15, 15a and 15b described above.

FIGS. 10 to 12 show a fourth embodiment, in which a female joint 2 is attached to the end of one steel pipe 1 to be connected.
Are attached by welding, and the male joint 6 is attached to the end of the other steel pipe 5 by the welds 4 and 8, respectively, in the same piping configuration as in the first to third embodiments. The difference is the joint fixing means of the male and female joints 2 and 6.
The joint fixing means in this case is as follows.

On the outer peripheral surface of the female joint 2, a pair of counterbored recesses 31 are provided at appropriate intervals in the circumferential direction, avoiding the female spline 9, and a through hole 32 is formed at the bottom of each counterbored recess 31. Is provided. A pair of upper and lower screw holes 33 is provided in the male spline 10 of the male joint 6 at a position matching the through hole 32 of the female joint 2. A bolt 34 is screwed into the screw hole 33 from the counterbore recess 31 through the through hole 32, and the male and female joints 2 and 6 are fixed in the tube axis direction.

In the same manner as described above, the annular groove 21 provided on the fitting surface on the front side in the fitting direction of the male joint 6 comes in contact with the U packing 21 made of nitrile rubber and the heel portion thereof. A backup ring 22 made of tetrafluoroethylene resin is mounted. An O-ring 23 made of nitrile rubber is mounted in the annular groove 21a provided on the fitting surface on the rear side in the fitting direction.

Also in this case, the male and female joints 2, 6
And the screw 34 is screwed into the screw hole 33 provided in the male joint 6 through the through-hole 31 without the need to adjust the tightening force as in the case of the flange joint. 2 and 6 can be fixed, and the U-packing 21 and the O-ring 23 allow the fluid in the pipe to be either a pressurized fluid or a fluid under reduced pressure.
The fitting surface is well sealed, so that leakage of fluid in the pipe and entry of water and dust from the outside can be prevented.

Instead of the O-ring 23, a lip packing such as a U-packing 21 may be mounted on the fitting surface on the rear side in the fitting direction of the male joint 6. Further, a plurality of annular grooves are formed in the fitting surfaces on the front side and the rear side in the fitting direction of the male and female joints 2 and 6, and U-shaped packing and O-shaped
A seal member such as a ring can be attached.

[0052]

As described above, according to the present invention, a pair of splines which are attached to the connection ends of the metal pipes for the fluid pipes and which are connected in the circumferential direction are formed in advance. By using male and female joints, seal members were attached to the fitting surfaces on both ends of the male joint in the pipe axis direction, so that the male and female joints were fitted, and the connection and fixing could be quickly performed by the aforementioned joint fixing means, Eliminates the need for time-consuming welding work on the plumbing site, even if repairs are needed,
The piping connection part can be easily separated, and piping workability is greatly improved.

Further, the fitting surface is well sealed by the mounting of the sealing member, so that leakage of fluid in the pipe and intrusion of water or dust from the outside can be prevented, and the pressurized state or the depressurized state can be prevented. It can be used to transport any fluid in the state.

Further, the sealing member also provides a cushion effect of absorbing a clearance in a radial direction and a circumferential direction of the fitting surface, and provides a mechanical connection between the pipe and the pipe due to a thermal stress caused by a change in the pipe temperature. It is also effective in preventing damage such as cracks in parts.

Thus, it is possible to realize a fluid pipe joint excellent in sealability and durability, which can connect and disconnect pipes at a construction site by a simple operation.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a fluid piping joint according to a first embodiment of the present invention.

FIG. 2 (a) is a longitudinal sectional view showing the connection state of the above.

FIG. 2 (b) is a longitudinal sectional view showing a connection state of another example of the above.

FIG. 3 is a cross-sectional view showing an alignment state between the female spline and the short tooth groove along the line III-III in FIG. 2 (a).

FIG. 4 is a cross-sectional view showing an inconsistent state between the female spline and the short tooth groove along the line III-III in FIG. 2 (a).

5A to 5E are cross-sectional views showing examples of splines.

FIG. 6 is an exploded perspective view of a female joint and a stopper according to the second embodiment.

FIG. 7 is a longitudinal sectional view showing a connection state of the above.

FIG. 8 is an exploded perspective view of a female joint and a stopper according to the third embodiment.

FIG. 9 is a longitudinal sectional view showing a connection state of the above.

FIG. 10 is an exploded perspective view of a fluid piping joint according to a fourth embodiment.

FIG. 11 is a longitudinal sectional view showing a connection state of the above.

FIG. 12 is a transverse sectional view taken along line II of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel pipe 2 Female joint 3 Engagement step part 4 Weld part 5 Steel pipe 6 Male joint 7 Flange part 8 Weld part 9 Female spline 9a Short tooth groove 9b Short tooth 10 Male spline 11 Inner peripheral groove 12 Receiving step part 13 Outer peripheral groove 14, 14a Taper portion 15, 15a, 15b Stopper 16 Slot 17 Screw 18 Screw hole 19 Filler 20, 20a Annular groove 21 U packing 22 Backup ring 23 O-ring 24 Male screw 25 Female screw 26, 26a Inner peripheral step 27 Flange 28 Guide groove 29 Through hole 30 Screw hole 31 Counterbore recess 32 Through hole 33 Screw hole 34 Bolt

Continued on the front page (72) Inventor Toshihiro Ueki 8-22, Tamachi, Motomachi, Tennoji-ku, Osaka F-term (reference) 3J039 AA03 BB01 CA02 GA02 3J040 AA01 AA13 BA05 EA40 FA06 HA03 3J106 AB01 BA01 BB01 BC04 BD01 BE12 BE13 BE27 BE29 CA19 EA03 EB05 EC02 EC07 ED12 EE01 EF04 EF05 EF12

Claims (7)

[Claims] 1. A pair of splines, which are composed of a cylindrical female joint and a male joint fitted thereto, are fitted on a fitting surface of the female joint and the male joint, and a pair of splines for connecting the two joints in a circumferential direction. A fluid piping joint comprising: a sealing member for sealing a mating surface; and means for fixing the joined female joint and male joint in the axial direction. 2. The fluid pipe joint according to claim 1, wherein the seal member is mounted in an annular groove provided in a fitting surface on both ends of a spline of the male joint. 3. The fluid piping joint according to claim 2, wherein the seal member mounted in the annular groove on the front side in the fitting direction of the male joint is a lip packing. 4. The joint according to claim 3, wherein a backup ring of the lip packing is mounted in the annular groove. 5. A means for fixing the joint in the axial direction, comprising: an inner circumferential groove formed in the inner circumference of the female joint across the spline and deeper than the tooth groove; An outer peripheral groove formed on the outer periphery of the male joint so as to traverse the spline, and the inner peripheral groove and the outer peripheral groove are fitted in an annular space formed to face each other so as to be movable in a circumferential direction. The stopper is formed by an arc-shaped stopper and stopper operating means for moving the stopper in the circumferential direction, a short tooth groove matching the spline of the female joint is formed on the inner surface of the stopper, and the stopper operating means is The fluid piping joint according to any one of claims 1 to 4, wherein the stopper is moved by at least a half pitch of the short tooth groove and fixed at a predetermined position. 6. The fluid pipe joint according to claim 5, wherein the stopper has an arc shape having a length of one-third or less, and at least three of the stoppers are used in an annular combination. 7. The stopper operating means is formed by an elongated hole provided in an inner peripheral groove portion of the female joint, and a screw inserted from the outside into the elongated hole and screwed to the stopper. Or the joint for a fluid piping according to 6.