JP2000179769A - Pipe fitting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance locking force for a male tube, and to simplify assembling. SOLUTION: A coil spring 6 and a sleeve 7 energized by the spring 6 axial- directionally outwards are inserted into an inner circumference of a female tube 2 serving as a fitting body. A tapered face 2e diameter-enlarged gradually toward a deep side is formed in an inner circumferential face of the female tube 2, and plural beadlike pieces contacting with the tapered face 2e and an outer circumferential face of a male tube 3 are arranged in a circumferential direction in the sleeve 7. An opening part penetrated in inner and outer circumferences arranged with the pieces 9 is formed in the sleeve 7, and a substantially ring-like wire inserted into the pieces 9 is engagedly held in an outer circumference of the sleeve 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint, and more particularly to a pipe joint that can be used for joining water pipes and the like.

[0002]

2. Description of the Related Art Conventionally, pipe joints with female threads are generally used for joining works such as pipes buried in waterworks. That is, a male screw is formed at the end of the pipe, and the male screw is screwed into the female screw of the pipe joint to join the pipe. However, in the case of such a joining method by screwing, it is necessary to form an external thread at the end of the pipe in advance, and it takes time and effort to process and also takes a great deal of time to join on site. There were drawbacks.

Further, if a bending force acts on a joint of a pipe due to an earthquake or the like, the conventional pipe joint cannot absorb the bending stress, so that an excessive stress acts on the pipe, causing cracks in the pipe or water leakage from a joint. A defect occurred.

To solve such a problem, as described in Japanese Patent Application Laid-Open No. 6-272795, a spring and an inner collar are inserted into a female pipe as a pipe joint main body from the back side. The inner surface of the female tube is formed with a tapered surface with a gradually increasing diameter on the inner side, and a plurality of balls in the inner collar are brought into contact with the tapered surface and the outer peripheral surface of the male tube inserted inside the female tube in the circumferential direction. There is proposed a pipe joint having a structure arranged in the following manner. If such a pipe joint is used, it is not necessary to process a male screw in advance at the end of the male pipe, which is a pipe, and it is only necessary to insert the male pipe into the female pipe at the time of joining, and the joining operation is simplified. There is an advantage. Further, since a slight change in the angle between the female pipe and the male pipe can be tolerated, it is possible to cope with bending.

[0005]

However, in the case of the above-mentioned pipe joint, there is a problem that the locking force with respect to the male pipe is low. That is, the inner collar is formed with a fitting hole that penetrates the inner and outer circumferences into which the ball is fitted. If the fitting hole is too large, the ball falls off to the inner diameter side of the fitting hole. A tapered fitting hole having a small diameter on the inner diameter side and a larger diameter on the outer diameter side is provided. However, in this case, since the ball can only slightly protrude toward the inner diameter side of the inner collar, there is a disadvantage that a large allowance for engagement between the ball and the male tube cannot be obtained, and the locking force on the male tube is small. Generally, the outer diameter of the water pipe has a variation of about 1%. Therefore, when a male pipe having a small outer diameter is inserted, the margin of engagement between the ball and the male pipe is further reduced, and the locking force is also reduced.

Further, in the case of the above-mentioned pipe joint, if the tapered surface is formed integrally with the female pipe, there is a disadvantage that the inner collar and the ball cannot be assembled to the female pipe. In other words, when assembling, even if the ball is inserted into the female pipe with the ball fitted in the fitting hole of the inner collar, the ball protrudes from the outer peripheral surface of the fitting hole, so that the ball interferes and the inner collar is removed. This is because it cannot be inserted into the female tube. for that reason,
An outer collar provided with a tapered surface must be formed separately from the female pipe, and this outer collar must be attached to the female pipe, and the structure of the pipe joint is complicated and large.

An object of the present invention is to provide a pipe joint which has a high locking force with respect to a male pipe and is easy to assemble.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, an elastic body is inserted into an inner periphery of a female pipe serving as a pipe joint body, and a shaft is formed by the elastic body. A sleeve urged outward in the direction is inserted, a tapered surface having a gradually increasing diameter on the inner side is formed on the inner peripheral surface of the female tube, and the tapered surface and the inner periphery of the female tube are inserted into the sleeve. In a pipe joint in which a plurality of locking members that come into contact with the outer peripheral surface of a male pipe are arranged in a circumferential direction, the locking members are formed of bead-shaped tops having through holes, and the tops are disposed in the sleeve. A pipe joint characterized in that an opening penetrating through the inner and outer peripheries is formed, and a substantially ring-shaped wire inserted through a through hole of the top is engaged and held on the outer or inner periphery of the sleeve. I will provide a.

In the present invention, bead-shaped tops are used as locking members, and these tops are inserted through wires. If this wire is engaged with the outer periphery or the inner periphery of the sleeve, it is possible to reliably prevent the top from falling off the sleeve. Since the opening formed in the sleeve does not need to prevent the top from dropping, the opening can be formed with a sufficient size, and high-precision processing as in the related art is unnecessary. Since the top can be displaced in the radial direction of the sleeve due to the elasticity of the wire, if the sleeve is inserted into the female pipe, the top will be displaced in the inner diameter direction against the female pipe, and the sleeve can be easily assembled to the female pipe.
That is, in the present invention, it is not necessary to form the tapered surface separately from the female pipe. However, it is a matter of course that the collar having the tapered surface may be formed separately from the female pipe, and this collar may be attached to the female pipe.

When the male pipe is inserted into the female pipe, the top projects from the opening of the sleeve toward the inner diameter side, and comes into contact with the outer peripheral surface of the male pipe. On the other hand, since the sleeve is urged outward by the elastic body, the top is pressed in the inner diameter direction by the tapered surface, so that the top is pressed against the outer peripheral surface of the male pipe. Since the top is inserted and supported by the wire, the top can be largely protruded from the opening of the sleeve toward the inner diameter side. Therefore, a large allowance for engagement between the top and the male tube is obtained, and the locking force with respect to the male tube is increased.

When removing the male pipe from the female pipe, the sleeve may be pushed inward against the elastic body. Thereby, the top also moves inward with the sleeve and separates from the tapered surface. Therefore, there is no longer any locking force on the male pipe, and the male pipe can be easily pulled out.

As the top, a spherical or cylindrical top may be used, but it is preferable to use a barrel-shaped top in which the central portion of the outer peripheral surface is expanded. That is, when a conventional ball is used, the ball and the tapered surface come into point contact, and the contact area is very small. for that reason,
When a large pulling force acts on the male pipe, the ball cuts into the tapered surface and the male pipe is easily pulled out. In particular, cast irons such as gray cast iron, mariable cast iron, and ductile cast iron are widely used for female pipes, which are the pipe joint body. However, cast iron has relatively low strength. When a pulling force is applied to the tube, the ball easily bites into the tapered surface. Therefore, it has been conventionally proposed to form the tapered surface separately from the female pipe. However, this increases the number of parts, increases the size of the pipe joint itself, and raises the cost. On the other hand, if a barrel-shaped top is used, the contact area between the top and the tapered surface increases, preventing biting into the tapered surface and allowing the tapered surface to be directly machined on the pipe joint body. And cost increase can be suppressed. The contact area can be further increased by making the radius of curvature of the barrel-shaped piece in the ridgeline direction closer to the radius of curvature of the tapered surface.

According to a third aspect of the present invention, when a knurl substantially parallel to the axial direction is formed on the peripheral surface of the barrel-shaped top, frictional resistance between the top, the tapered surface, and the male pipe increases, and the engagement with the male pipe increases. The stopping force is further increased.

It is preferable that one end of the sleeve is axially protruded from the female tube, and an outer flange portion protruding in the outer radial direction is formed on the protruded portion. In other words, when removing the male pipe from the female pipe, it is necessary to push the sleeve in the female pipe direction. However, the operation can be easily performed by pressing the outer flange portion.

It is preferable that a fixing screw capable of abutting on the end face of the female pipe is axially screwed to the outer flange portion of the sleeve. In this case, after inserting the male tube into the female tube, the sleeve is forcibly pulled outward by tightening the fixing screw and pressing the tip against the end surface of the female tube,
The top can be pressed against the tapered surface. for that reason,
The male pipe is in the locked state, and can exert a strong locking force against the pulling force. Further, even if a pressing force is applied to the sleeve in the female pipe direction by mistake, the sleeve cannot move in the axial direction, so that the male pipe does not come off.

[0016]

1 to 5 show a first embodiment of a pipe joint according to the present invention. The pipe joint 1 of this embodiment includes a female female pipe 2 serving as a pipe joint main body, and is used to connect two male pipes 3. Since the female tube 2 has a symmetrical structure, only the structure at one end will be described.

On the inner surface of the female pipe 2, two concave grooves 2
a, 2b are formed, and O
Seal members 4 and 5 such as rings are fitted. A storage groove 2d is formed adjacent to the outer concave groove 2b via a partition wall 2c, and a tapered surface 2e having a gradually increasing diameter on the back side is formed at the outer end of the storage groove 2d. An inner flange portion 2f slightly protruding in the inner diameter direction is provided at the opening end of the distal end portion of the female pipe 2.
(See FIG. 2).

A coil spring 6 as an example of an elastic body and a sleeve 7 urged outward by the coil spring 6 are inserted into the storage groove 2d. In addition, it is also possible to use a leaf spring or elastic rubber instead of the coil spring 6. As shown in FIGS. 3 to 5, the sleeve 7 is formed in a cylindrical shape with a material having hardness such as a metal material or a resin, and a guide portion 7a for receiving the inner diameter side of the coil spring 6 is provided at one end thereof. Have been. At the center of the sleeve 7, there are a plurality of openings 7b penetrating the inner and outer circumferences (four in this embodiment) at equal intervals in the circumferential direction.
Is formed. An engagement groove 7c is formed on the outer peripheral surface of the sleeve 7 and between the openings 7b, and a stop ring 8 (FIG. 2) is formed on the outer side in the axial direction of the engagement groove 7c.
7) is formed. The outer diameter of the stop ring 8 in the free state is slightly larger than the outer diameter of the sleeve 7, and when the sleeve 7 is inserted into the female pipe 2, the stop ring 8 is locked by the inner flange 2 f of the female pipe 2 and Has a role to keep out. In addition,
The circumferential length of the opening 7b is considerably longer than the axial length of the top 9 described later, and the radial depth of the opening 7b is formed smaller than the diameter of the top 9. The other end of the sleeve 7 protrudes outward in the axial direction from the female pipe 2, and the protruding portion is formed with an outer flange portion 7 e protruding in the outer diameter direction.

A bead-shaped top 9 is fitted into the opening 7b of the sleeve 7, and a part of the top 9 protrudes in and out of the opening 7b. The top 9 is formed of a metal material having high hardness, and has a through hole 9a penetrating in the axial direction. The radius of curvature in the ridge direction of the outer peripheral surface of the top 9 is set to be substantially equal to the radius of curvature of the tapered surface 2e so that the top 9 can come into contact with the tapered surface 2e almost in plane. A substantially ring-shaped metal wire 10 is inserted through the through hole 9a, and the top 9 is rotatable with respect to the wire 10 and slidable in the circumferential direction. The wire 10 may have an endless circular shape, but the wire 10 of this embodiment is formed in a substantially C-shape with both ends overlapping (see FIG. 5). In the case of a C-shape, both ends may be bent and locked to the sleeve 7 without overlapping both ends. The inner diameter of the wire 10 is smaller than the outer diameter of the bottom of the engagement groove 7c of the sleeve 7 in the free state, and the wire 10 is elastically fitted and held in the engagement groove 7c of the sleeve 7.

Here, a method of assembling the sleeve 7 to the female pipe 2 will be described. The top 9 is the wire 1 as described above.
The wire 9 is elastically engaged with the engagement groove 7 c of the sleeve 7, so that the top 9 corresponds to the opening 7 b of the sleeve 7. The top 9 protrudes in the inner diameter direction and the outer diameter direction of the opening 7b (see FIG. 4). In this way, since the sleeve 7, the top 9 and the wire 10 are integrally assembled, the top 9 does not fall off the sleeve 7 and the handling becomes easy.

When the coil spring 6 is inserted into the female tube 2 in a state where one end of the coil spring 6 is engaged with the guide portion 7a of the sleeve 7 assembled as described above, the frame projecting from the sleeve 7 in the outer diameter direction. 9 corresponds to the inner peripheral edge of the female pipe 2. Here, when the sleeve 7 is pushed in, the portion of the wire 10 located in the opening 7 b is bent and the top 9 is displaced toward the inner diameter side, so that the top 9 sinks into the inner peripheral side of the female pipe 2 and the sleeve 7 is inserted. be able to. Then, when the sleeve 7 is pushed inward, the other end of the coil spring 6 hits the partition wall 2c of the female pipe 2. When the insertion of the sleeve 7 is completed, the sleeve 6 is urged outward by the coil spring 6, and the top 9 projects in the outer diameter direction due to the elasticity of the wire 10, so that the top 9 comes into contact with the tapered surface 2e. As a result, the retaining force of the sleeve 7 against the female pipe 2 is generated, but the spring force of the coil spring 6 is strong and the sleeve 7
If it is impossible to prevent the sleeve 7 from coming off, the stop ring 8 is fitted into the circumferential groove 7d of the sleeve 7, and the stop ring 8 is locked to the inner flange portion 2f of the female pipe 2, so that the sleeve 7 is securely prevented from coming off. it can.

When the male tube 3 is inserted into the female tube 2 assembled as described above, the diameter of the envelope circle connecting the inner peripheral surfaces of the plurality of pieces 9 is smaller than the outer diameter of the male tube 3. Tube 3
Is pressed against the top 9 projecting in the inner diameter direction from the opening 7b. Then, the top 9 rotates with the insertion of the male pipe 3, and the male pipe 3 is inserted smoothly. When the male pipe 3 is inserted as far as it will go, the tip of the male pipe 3 hits a stop wall 2g provided at the innermost part of the female pipe 2 and stops. Even if tap water flows through the male pipe 3 in a state where the male pipe 3 is inserted into the female pipe 2, two sealing members 4 and 5 are interposed between the male pipe 3 and the female pipe 2. Therefore, water leakage is reliably prevented. Further, even if a bending force acts on the male pipe 3 due to a crustal deformation such as an earthquake, a certain degree of bending is allowed by the gap between the male pipe 3 and the female pipe 2.

Further, there is a case where an external force in the pulling direction acts on the male pipe 3 or a force in the pulling direction acts on the male pipe 3 due to the water pressure flowing in the male pipe 3. At this time, when the male pipe 3 tries to move in the pulling-out direction with respect to the female pipe 2, the top 9 strongly hits the tapered surface 2e and is urged in the inner diameter direction. For this reason, the top 9 strongly presses against the outer peripheral surface of the male pipe 3 to restrict the movement of the male pipe 3 in the removal direction. In particular, since the outer surface of the top 9 of this embodiment is formed in a barrel shape, the tapered surface 2e is formed.
The contact area with the ball is larger than that of the ball. Therefore, even if the tapered surface 2e is formed of a material having relatively low strength, such as cast iron, it is possible to reliably prevent the top 9 from cutting into the tapered surface 2e. In this way, the male tube 3 can be reliably prevented from coming off.

When it is necessary to remove the male pipe 3 from the female pipe 2, first, the outer flange portion 7e of the sleeve 7 is connected to the female pipe 2.
Push in the direction. Thereby, the top 9 held by the sleeve 7 moves to the inner side of the female tube 2 and separates from the tapered surface 2e. When the male pipe 3 is pulled in this state, the top 9 rolls on the outer peripheral surface of the male pipe 3, so that the male pipe 3 can be easily pulled out.

FIG. 6 shows another embodiment of the top 9. In this embodiment, a knurl 9b substantially parallel to the axial direction is formed on the outer peripheral surface of the barrel-shaped top 9. In this case,
The knurl 9b is pressed against the tapered surface 2e and the outer peripheral surface of the male pipe 3 to generate a larger frictional force, so that the male pipe 3 can be reliably prevented from coming off from the female pipe 2.

FIG. 7 shows a second embodiment of the pipe joint. In this embodiment, the outer diameter of the outer flange portion 7e of the sleeve 7 is increased, and a fixing screw 11 capable of abutting on the end face of the female pipe 2 is screwed to the outer flange portion 7e in the axial direction. The fixing screw 11 is provided, for example, in the circumferential direction of the outer flange portion 7e.
It may be provided at a location.

In the case of this embodiment, the top end of the fixing screw 11 abuts against the end face of the female pipe 2 and constantly applies an outward pulling force to the sleeve 7 so that the top 9 is constantly tapered. 2e and the outer peripheral surface of the male pipe 3 can be brought into pressure contact with each other. That is, even if some external force acts on the sleeve 7 inward, the sleeve 7 does not move, and the top 9 does not separate from the tapered surface 2e. Therefore, the male pipe 3 can be strongly locked.

In the embodiment shown in FIG. 7, the peripheral groove 7d into which the stop ring 8 is fitted has a stepped shape. That is,
When the sleeve 7 is inserted into the female pipe 2, the outer diameter of the outer peripheral portion of the circumferential groove 7d in the axial direction is reduced so that the stop ring 8 is easily bent to the inner diameter side. The outer diameter of the inner portion in the axial direction of the circumferential groove 7d is increased so as not to cause displacement in the radial direction. Thereby, the sleeve 7 can be reliably prevented from coming off.

FIG. 8 and FIG. 9 show another embodiment of the sleeve 7. In the sleeve 7 of this embodiment, the length of the opening 7b in the circumferential direction is shorter than in FIGS. 3 and 4 in order to reduce the displacement of the top 9 in the circumferential direction. When the length of the opening 7b in the circumferential direction is shortened, the wire 10 is hardly bent. Therefore, in order to secure the amount of bending of the wire 10, inclined grooves 7f are formed at both circumferential ends on the outer peripheral surface side of the opening 7b. Wire 1
When 0 is bent in the inner diameter direction, a part of the wire 10 is fitted into the inclined groove 7f.

In the above embodiment, the female pipe constituting the pipe joint body has a socket shape open in two directions. However, a structure may be employed in which a screw is formed at one end and screwed to the pipe. Further, it is needless to say that the female pipe may be provided with a connection port in three directions or four directions. Further, the pipe joint of the present invention can be used not only for connecting a metal pipe such as a steel pipe, but also for connecting a relatively rigid resin pipe. The opening of the sleeve does not need to be a hole, and may be, for example, a cutout opening at one end in the axial direction. In the above embodiment, the wire 10 is
Although the engagement groove 7c formed on the outer peripheral surface of the sleeve 7 is engaged and held, the engagement groove may be formed on the inner peripheral surface of the sleeve 7 and the wire 10 may be engaged with the engagement groove from the inner diameter side.

[0031]

As is apparent from the above description, according to the present invention, a bead-shaped top is used as a locking member, and a substantially ring-shaped wire inserted through a through hole of the top is used on the outer periphery of the sleeve. Since the pieces are held together, the pieces are held by the wire, and the pieces can be largely protruded toward the inner diameter side of the sleeve. Therefore, a large allowance for engagement between the top and the male pipe can be obtained, and the locking force with respect to the male pipe can be increased. Also, if the wire is engaged with the outer circumference of the sleeve,
Since the top and sleeve can be assembled integrally,
The top does not fall off the sleeve, and the handling becomes easy. The top can be displaced in the radial direction of the sleeve by the elasticity of the wire, so if you insert the sleeve into the female tube,
The top is displaced in the inner diameter direction against the female pipe, and the sleeve can be easily assembled to the female pipe. Also, the tapered surface can be formed integrally with the female pipe, which has the effect of simplifying the structure.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of a pipe joint according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a sectional view of a sleeve.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is an exploded perspective view of a sleeve, a top, and a wire.

FIG. 6 is a front view of another embodiment of a frame.

FIG. 7 is a partial sectional view of a second embodiment of the present invention.

FIG. 8 is a sectional view of a sleeve according to a third embodiment of the present invention.

FIG. 9 is an enlarged sectional view taken along line BB of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe fitting 2 Female pipe (pipe fitting main body) 3 Male pipe (piping) 4, 5 Seal material 6 Coil spring (elastic body) 7 Sleeve 9 Top 10 Wire

Claims (5)

[Claims] An elastic body is inserted into an inner circumference of a female pipe which is a pipe joint body, and a sleeve urged outward in the axial direction by the elastic body is inserted into the inner circumference of the female pipe. A tapered surface having a gradually increasing diameter on the back side is formed, and a plurality of locking members that are in contact with the tapered surface and the outer peripheral surface of the male pipe inserted into the inner circumference of the female pipe are arranged in the sleeve in the circumferential direction. In the pipe joint, the locking member is formed of a bead-shaped top having a through hole, and the sleeve has an opening formed in the inner and outer circumferences where the top is disposed, and the outer or inner circumference of the sleeve is formed. Wherein a substantially ring-shaped wire inserted into a through hole of the top is engaged and held. 2. The pipe joint according to claim 1, wherein said top has an outer peripheral surface formed in a barrel shape. 3. A knurl substantially parallel to an axial direction is formed on a peripheral surface of the top.
The pipe joint according to 1. 4. The sleeve according to claim 1, wherein one end of the sleeve projects axially from the female pipe, and the projecting portion has an outer flange portion projecting in an outer radial direction. The pipe joint according to any one of the above. 5. The pipe joint according to claim 4, wherein a fixing screw capable of abutting on an end face of the female pipe is screwed in the outer flange portion in an axial direction.