JP3000711U - Telescopic flexible joint - Google Patents

Abstract

(57) [Summary] [Purpose] It is arranged at the joint of pipes to hold the pipes and
Provided is a joint that absorbs expansion and contraction in the axial direction and flexure in the direction perpendicular to the axis due to an external force, and that has stable expansion and contraction and flexibility, and that can reduce the number of parts. [Structure] A barrel 2 which is disposed so as to surround the outer periphery of the pipe at a joint of the pipe 8, a cap nut 3 screwed to both ends of the barrel, and a gap between the cap nut 3 and the outer periphery of the pipe 8. A ball 11 that is provided and is pressed against the outer circumference of the pipe 8 by the tapered surface 9 on the inner surface of the cap nut 3.
And a ball gripping member 10 for holding the same, a flexible rubber packing 4, and rubber rings 6, 7 of a sealing member. The tube 8 is gripped by the pressing force of the ball 11 with a predetermined gripping force, and the ball 1
It may be flexible with the contact point of 1 as the base point. Tube gripping member 10
Since it is formed of an integrated structure, the number of parts can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a joint provided at a joint of a stainless steel pipe used for water supply or the like, and more particularly to a flexible joint having gripping properties and a small number of parts.

[0002]

[Prior art]

 Flexible joints have been used for joints of pipes such as stainless steel pipes for water supply. As specified in the Japan Water Works Association Standard (JWWA), the flexible joint is capable of maintaining watertightness and preventing the pipe from slipping out, as well as fluctuations in the axial direction of the pipe due to external force (expansion and contraction) and lateral movement. It has a structure that absorbs fluctuations (deflection) in the direction (the direction perpendicular to the axis), and grips the pipe ends at the joints to connect the pipes. Due to its flexible function, the joint is mainly used for joints of buried pipes in the ground, where the environment is severe such as earthquakes, ground subsidence, and under the road where heavy vehicles pass. More specifically, pipes buried in the ground will expand and contract in the axial direction due to the influence of external forces such as earthquakes, but if the pipe does not expand or contract under a certain load or more, equipment such as water faucet Unreasonable force may be applied to the and damage the equipment. In addition, if the flexible angle of the pipe is not flexibly handled to some extent, there will be a problem in that each device is damaged due to an unreasonable force similarly to the above. On the other hand, since it is a joint, it is necessary to securely grasp the pipe and connect the joints of the pipe. Conventionally, the expandable joints having the above functions shown in FIGS. 6 and 7 have been used.

As shown in FIG. 6, a conventional expandable flexible joint 1a includes a body 2a, a cap nut 3a, a rubber packing 4a, a washer 5a, rubber rings 6a and 7a, and a pipe 8. The engaging ring 15 is engaged with the retaining ring 15 and the retainer 16 interposed between the retaining ring 15 and the cap nut 3a.

[0004]

[Problems to be solved by the device]

 In the case of the conventional expandable flexible joint 1a, in order to grip the pipe 8, the cap nut 3a is screwed onto the body 2a, and the tapered surface 9a of the inner surface of the cap nut 3 pushes the retainer 16 toward the bite ring 15 side. The pipe 15 has a structure in which the pipe 15 is pressed against the outer periphery of the pipe 8 to hold the pipe 8. On the other hand, as shown in FIG. 7, the bite ring 15 includes a coil main body 17 in which a spring member is wound in a coil shape along a circumference, and a circle for holding the coil main body 17 in a ring shape by being inserted into the coil main body 17. It is formed of the peripheral ring member 18 and the like. The tube 8 is flexibly supported by the retainer 16 by the pressing force of the bite ring 15 and the elasticity of the bite ring 15 so as to be expandable and contractible. However, the conventional expandable flexible joint 1a is composed of a large number of constituent members as described above, and particularly requires the retainer 16 and the bite ring 15 having a complicated shape, so that the entire structure is complicated and the assembly is troublesome. . Further, there is a problem that the positional relationship between the tapered surface 9a of the bag nut 3a and the retainer 16 and the bite ring 15 is likely to change.

The present invention solves the above problems and provides an expandable flexible joint that has a small number of parts, is easy to assemble, has stable elasticity and flexibility, and can be inserted and removed with one touch. The purpose is to do.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is installed on a joint of pipes that are adjacently joined to each other, and grips the pipes so as to absorb the expansion and contraction in the axial direction and the bending in the direction perpendicular to the axis due to the external force of the pipes. A joint that encloses a seam portion of the pipe with a gap and extends along the axial direction by an appropriate axial length and has a threaded portion on both outer circumferences. A cap nut that is inserted into the pipe and screwed into both ends of the barrel and forms a tapered surface on the inner surface, and a snap ring-shaped pipe grip provided between the tapered surface of the cap nut and the outer periphery of the pipe. A member, an elastic member interposed between the inner surface of the body and the outer circumference of the pipe, and a seal member for sealing between the bag nut side and the outer circumference of the pipe, wherein the pipe gripping member is the bag. When the nut is screwed, press contact with the tapered surface and the outer circumference of the pipe respectively. That a plurality of balls is also to constitute a Flexible Joints Fittings formed by providing the ball guide which forms a slit in a part of the circumference while holding the ball. More specifically, the pipe gripping member is provided with a ring-shaped restraining member for holding the member in a predetermined circular shape, the elastic member is a rubber packing, and the ball guide is made of a resin material. The ring restraining member is made of a snap ring or a rubber member fitted to the ball guide side.

[0007]

[Action]

 Cap nuts are screwed to both ends of the body that is laid around the pipe at the joint portion of the pipe. Between the inner surface of the cap nut and the pipe, only a pipe gripping member having an integral structure is provided. When the cap nut is screwed, its tapered surface presses the ball of the pipe gripping member toward the outer peripheral side of the pipe. The balls are guided by a ball guide and are arranged along the same circumferential direction to make uniform point contact with the pipe. Although the tube is securely gripped by the pressing force of the ball, the ball and the tube are in point contact with each other so that they can be expanded and contracted and are flexible, and their elasticity and flexibility are stable. Further, the pipe gripping member is composed of a ball and a ball guide having an integral structure, and is easy to assemble. Further, by attaching the restraint member, the pipe gripping member is safely held at a predetermined position. The elastic member of the rubber packing functions flexibly, and the seal member functions to prevent water leakage between the joint and the pipe.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 is an axial sectional view showing the overall structure of the present embodiment, FIG. 2 is an enlarged axial sectional view of a pipe gripping member of the present embodiment, FIG. 3 is a sectional view taken along line AA of FIG. 2, and FIG. 4 is a pipe gripping member. FIG. 5 is an enlarged axial sectional view of another embodiment, and FIG. 5 is an axial sectional view showing the elastic member of the present embodiment.

As shown in FIG. 1, the expandable flexible joint 1 of this embodiment is roughly divided into a body 2, a bag nut 3, a rubber packing 4 which is one of elastic members, and a washer 5. A rubber ring 6 and a rubber ring 7, which are one of the sealing members, and a pipe gripping member 10 and the like, and are installed between pipes 8 which are adjacently joined. The pipes 8, 8 and the body 2 and the cap nut 3 are made of stainless steel.

The body 2 is made of a hollow circular tube having an inner diameter larger than the outer diameter of the pipe 8, and surrounds the joint of the pipe 8 and is installed between the joints of the pipe 8 via a gap. Bulged portions 20 are formed at both ends thereof. On the inner surface of the bulging portion 20, a tapered surface 21 and a large-diameter portion 22 formed straight from the diameter-expanded end thereof are formed. A threaded portion 23 is formed on the outer periphery of the bulging portion 20 in the large diameter portion 22. A protrusion 24 for preventing rotation is integrally formed in the center of the body 2.

The cap nut 3 is composed of a nut-shaped member that is loosely inserted into the pipe 8, and has an internal thread portion 25 that is screwed into the screw portion 23 of the body 2 on its inner surface and a diameter that decreases in the extension direction of the pipe 8. The tapered surface 9, a stepped surface 26 formed between the large diameter side of the tapered surface 9 and the female screw portion 25, a concave groove 27 into which the rubber ring 7 is fitted, and the like are formed.

The rubber packing 4 is formed of a rubber material, and as shown in FIG. 1, a contour that abuts the tapered surface 21 of the bulging portion 20 of the case body 2 and the straight large-diameter portion 22 is formed on the outer periphery and the rubber packing 4 is formed. It has an inner hole inserted into the outer periphery. The rubber packing 4 flexibly supports the pipe 8. As shown in FIG. 5, in this embodiment, the rubber packing 4 and the washer 5 are integrally bonded to each other to improve the assembling property. Of course, the rubber packing 4 and the washer 5 may be separate bodies. The washer 5 is interposed between the stepped surface 26 of the bag nut 3 and the end surface of the rubber packing 4, and is pressed against both surfaces by screwing the cap nut 3 onto the case body 2.

In this embodiment, the seal member is composed of the rubber ring 6 and the rubber ring 7 as described above. The rubber ring 6 is attached to the outer peripheral side of the washer 5 and is filled in the gap between the outer periphery of the washer 5 and the inner surface of the cap nut 3 to prevent leakage from the threaded portion of the body 2 and the cap nut 3. . On the other hand, the rubber ring 7 is fitted into the concave groove 27 of the cap nut 3, and its lip portion 28 abuts the outer periphery of the pipe 8 and functions to seal the gap between the cap nut 3 and the pipe 8.

Next, the pipe gripping member 10 which is a main component of this embodiment will be described with reference to FIGS. 1 to 3. The tube gripping member 10 includes a plurality of balls (11 in this embodiment) 11 and a ball guide 12 that holds the balls 11. In this embodiment, as shown in FIG. 2, a snap ring 13 which is one of ring-shaped restraining members is fitted to a locking portion 14 formed integrally with the ball guide 12. The ball guide 12 is made of, for example, a ring-shaped member made of a synthetic resin material such as polyacetal (POM), and as shown in FIGS. 2 and 3, a slit portion 19 is formed in a part of the circumference to form an outer circumference. It is formed to be expandable and contractible. The ball 11 is made of a steel ball. As shown in FIGS. 2 and 3, the ball guide 12 has an intermediate portion embedded therein and is supported, and the ball guide 12 is disposed so as to slightly project to the outer surface side and largely project to the inner surface side. . The pipe gripping member 10 is inserted into the gap between the pipe 8 and the taper surface 9 of the cap nut 3, and when the cap nut 3 is screwed into the case 2, the taper surface 9 is a ball 11 or a ball guide. It is formed of a material having a relative dimension capable of abutting the outer circumference of 12 and pressing the inner surface side of the ball 11 against the outer circumference of the tube 8. The snap ring 13 is fitted into the locking portion 14 of the ball guide 12 as described above. With the snap ring 13 fitted, the ball guide 12 narrows the slit portion 19 to form a substantially circular contour. Formed to hold.

Next, the operation of this embodiment will be described. First, a method of connecting the pipes 8 and 8 according to this embodiment will be described. The rubber packing 4 to which the washer 5 is attached is inserted into the bulging portion 20 of the body 2. The tubes 8 and 8 are inserted into the case 2 from opposite directions. Next, the rubber ring 6 is fitted on the outer periphery of the washer 5, and the pipe gripping member 10 is inserted on the outer periphery of the pipe 8. Next, the cap nut 3 loosely inserted in advance on the outer circumferences of the pipes 8 and 8 is screwed into the barrel 2 and tightened with an appropriate tightening force. As a result, the tapered surface 9 hits the ball 11 and presses the ball 11 toward the tube 8. Since the pipe 8 is formed of a relatively thin pipe, the pressed portion of the ball 11 is partially deformed into a concave shape, and the movement of the pipe 8 in the axial direction is restricted at this portion. Further, when the cap nut 3 is tightened, the rubber ring 6, the washer 5 and the rubber packing 4 are pressed toward the body 2 side to seal the gaps. Since the snap ring 13 is fitted to the pipe gripping member 10 as described above, the pipe gripping member 10 is fitted to the outer periphery of the pipe 8 and its movement in the axial direction is restricted. Further, as described above, the lip portion 28 of the rubber ring 7 is brought into pressure contact with the outer periphery of the pipe 8 to exert the sealing function. As described above, the pipes 8 are connected to each other by a simple assembling method in which the cap nut 3 is screwed to the body 2.

When an external force acts on the pipe 8 and the pipe 8 tries to expand and contract in the axial direction, a tensile force or a compressive force in the axial direction acts on the contact portion between the ball 11 and the pipe 8. When an external force above a certain level is applied, slippage occurs at the point contact portion between the ball 11 and the tube 8 and the tube 8 moves in the axial direction. Therefore, no unreasonable force acts on the pipe 8 and damage to unillustrated instruments connected to the pipe 8 does not occur. In particular, since the tube 8 and the ball 11 engage with each other in a point contact state, the tube 8 can be moved relatively smoothly and in a stable state. On the other hand, the pipe 8 is flexible with the pressure contact point between the ball 11 and the pipe 8 as a base point, and the flexible angle is kept within a predetermined value by the rubber packing 4 or the like. Also in this case, since the base point is the point contact portion between the ball 11 and the tube 8, the flexible angle can be kept within a predetermined value.

FIG. 4 shows another embodiment of the tube holding member. This pipe gripping member 10a has a rubber ring 29 fitted to the engaging portion 14 instead of the snap ring 13 shown in FIG. 2, and the structure of the other parts is the same as that of FIG. The same effect as described above can be obtained by the pipe gripping member 10a.

[0018]

[Effect of device]

 According to the present invention, the following remarkable effects are obtained. 1) The expandable flexible joint of the present invention can reduce the number of parts as compared with the conventional one by adopting the tube gripping member having an integral structure. In addition, the assembling work becomes easy and the assembling work efficiency can be improved. 2) Since a ball is used as a gripping member for the pipe, the gripping force can be maintained uniformly, and at the same time, a stable response to expansion and contraction of the pipe becomes possible. 3) Since the pipe can be made flexible with the point contact point between the ball and the pipe as the base point, the flexibility is stable. 4) Also, the flexible joint of the present invention can be inserted and removed with one touch. 5) The structure is simple and can be implemented at a relatively low cost compared to the conventional pipe gripping member.

[Brief description of drawings]

FIG. 1 is an axial sectional view showing the overall structure of an embodiment of the present invention.

FIG. 2 is an enlarged axial sectional view of a pipe gripping member, which is a main part of this embodiment.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is an enlarged axial sectional view showing another embodiment of the pipe gripping member.

FIG. 5 is an enlarged axial sectional view showing an embodiment of an elastic member according to the present invention.

FIG. 6 is an axial sectional view showing the overall structure of a conventional expandable flexible joint.

7 is a partial front view of a pipe gripping member of the flexible joint of FIG.

[Explanation of symbols]

 1 Expansion and contraction flexible joint 2 Body 3 Cap nut 4 Rubber packing 5 Washer 6 Rubber ring 7 Rubber ring 8 Pipe 9 Tapered surface 10 Pipe gripping member 10a Pipe gripping member 11 Ball 12 Ball guide 13 Snap ring 14 Locking part 19 Slotting Part 20 Bulging part 21 Tapered surface 22 Large diameter part 23 Screw part 24 Projection part 25 Female thread part 26 Stepped surface 27 Recessed groove 28 Lip part 29 Rubber ring

Claims (4)

[Scope of utility model registration request] 1. A joint, which is installed on a joint of adjacent pipes and holds the pipes so as to absorb expansion and contraction in the axial direction and flexure in a direction perpendicular to the axial line due to an external force of the pipes. And a cylinder formed by surrounding a seam portion of the pipe by extending an appropriate axial length along the axial direction and screwing threaded portions on the outer circumferences of both ends of the pipe. A cap nut that is screwed at both ends of the cap nut and forms a tapered surface on the inner surface; a snap ring-shaped pipe gripping member that is interposed between the tapered surface of the cap nut and the outer periphery of the pipe; An elastic member provided between the outer circumferences of the pipes, and a seal member for sealing between the cap nut side and the outer circumference of the pipes, wherein the pipe gripping member is the tapered surface when the cap nuts are screwed together. A plurality of balls that are pressed against the outer circumference of the pipe, and the balls An expansion-contraction flexible joint characterized by comprising a ball guide that holds and forms a slit portion in a part of the circumference. 2. The expandable joint according to claim 1, wherein the pipe gripping member is provided with a ring-shaped restraining member for holding the member in a predetermined circular shape. 3. The expandable joint according to claim 1, wherein the elastic member is a rubber packing, and the ball guide is made of a resin material. 4. The expandable joint according to claim 2, wherein the ring restraining member is a snap ring or a rubber member fitted to the ball guide side.