JPH07280147A - Separation preventing device for fluid pipe - Google Patents

Abstract

PURPOSE:To prevent a fluid pipe from turning in the circumferential direction of the pipe and at the same time to prevent the lowering of separation preventing force in the axial direction of the pipe due to the turning in the separation preventing device for a fluid pipe in which a locking piece is provided. CONSTITUTION:A separation preventing claw 42 and besides a rotation preventing claw 43 are provided. The rotation preventing claw 43 is constituted of a long projection in the direction including the component of the axial direction S and receives the pushing force of a pushing bolt 7 to cut into the outer surface 2b of a second fluid pipe 2. Thereby, it engages with the second fluid pipe 2 in the axial direction thereof to prevent both fluid pipes 1, 2 from being turned mutually in the circumferential direction thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing separation of a fluid pipe such as a water pipe or a gas pipe, and more particularly to a locking piece to which a pressing force is applied by the axial force of a bolt.

[0002]

2. Description of the Related Art In a recent separation prevention device, a recess is formed in the inner peripheral portion of a so-called push ring, a locking piece is attached to the recess, and a claw in the pipe circumferential direction provided on the locking piece is attached. The outer surface of the fluid pipe is bited to prevent the fluid pipe from coming off in the axial direction of the fluid pipe (see, for example, JP-A-62-184294). In such a disengagement prevention structure, by making the locking piece into a wedge shape, the claws deeply bite as the pulling force in the tube axis direction acts, so that a so-called push screw type (for example, Japanese Utility Model Publication No. 54-2424). The detachment prevention force is drastically increased as compared with the one described in Japanese Patent No.

[0003]

Here, in the push-screw type, since the tip of the push-screw is a dent, the two fluid pipes are not restricted to each other in the axial direction of the pipe, but also in the circumferential direction of the pipe. The fluid tube may be prevented from rotating. In the pipe circumferential direction,
It was generally recognized that the rotational force did not work, so that the circumferential rotation blocking force was not necessary.

However, the present inventor has found the following error in this recognition and completed the present invention. In other words, when the fluid pipe rotates relatively in the pipe circumferential direction, the state of the contact surface of the bolt that presses the wedge-shaped locking piece changes, so that the locking piece is pressed inward in the radial direction of the pipe. It is expected that the pressing force applied will decrease. It is also expected that the rotation of the fluid pipe in the axial direction of the fluid pipe changes the biting state of the claw with respect to the outer periphery of the fluid pipe, and the desired detachment preventing force cannot be obtained.

For example, in FIG. 10A, when a part of the fluid pipe 100 shown by a solid line is exposed on the ground at an angle θ, the weight of the fluid pipe 100 and the non-average force acting on the curved pipe portion 101 cause In some cases, a moment acts in the circumferential direction R of the buried pipe 102 to rotate the fluid pipe 100. As described above, when the fluid pipe 100 rotates in the pipe circumferential direction R, the engagement state between the claw and the fluid pipe may slightly change, and as a result, the separation preventing force may decrease.

Further, as shown in FIG. 10 (b), when the air valve, the digestive plug 103, etc. are branched upward in the pit and taken out, they may rotate in the pipe circumferential direction R due to their own weight or the like. In such a case, there has been an inconvenience that the branch portion must be separately supported and constructed by using a rotation preventing support tool.

On the other hand, as described above, the so-called push-screw type one cannot obtain another great separation preventing force.

The present invention has been made in view of the above conventional problems, and an object thereof is to prevent a fluid pipe from rotating in the circumferential direction in a device for preventing separation of a fluid pipe provided with a locking piece. At the same time, it is to prevent a decrease in the detachment prevention force in the tube axis direction due to rotation.

[0009]

In order to achieve the above object, the present invention is characterized in that a rotation preventing claw is provided in addition to the separation preventing claw. The anti-rotation claw is composed of a long ridge extending in a direction including a component in the axial direction of the tube, and receives a pressing force of a bolt to bite into the outer surface of the second fluid pipe to engage with the second fluid pipe in the circumferential direction. Together, the two fluid pipes are prevented from rotating in the pipe circumferential direction.

According to the second aspect of the present invention, all the locking pieces are provided with the both pawls, and the shapes of the locking pieces are set to be the same. On the other hand, all the locking pieces may be provided with the separation preventing claws, and some of the locking pieces may be provided with the rotation preventing claws.

According to the fourth aspect of the invention, the protrusion height of the rotation preventing claw is set smaller than the protrusion height of the separation preventing claw.

In the invention of claim 5, the total length of the rotation preventing claws is set shorter than the total length of the separation preventing claws.

[0013]

According to the present invention, since both pawls provided on the locking piece bite into the outer surface of the second fluid pipe to engage in the pipe axial direction and the pipe circumferential direction of the second fluid pipe, they are connected. It is possible to prevent the two fluid pipes from separating from each other and prevent the fluid pipes from rotating in the pipe circumferential direction.

[0014]

As described above, according to the present invention, since the rotation preventing claws are provided in addition to the separation preventing claws, it is possible to prevent both the connected fluid pipes from rotating in the circumferential direction. Since the rotation of the fluid pipe can be prevented, an unexpected change does not occur in the engagement state between the claw and the fluid pipe, and therefore, there is no fear that the detachment prevention force will decrease due to the rotation of the fluid pipe. .

Further, if all the locking pieces are set to have the same shape, the number of types of parts does not increase, so that the manufacturing of the locking pieces is easy and there is no risk of cost increase, and maintenance is also easy. is there.

By the way, in order to allow the disengagement preventing claw of the locking piece to bite to a predetermined depth in the initial state, it is necessary to press the disengagement preventing claw against the outer surface of the second fluid pipe with a predetermined pressing force. With the provision of the rotation preventing claw, it becomes necessary to increase the tightening torque of the bolt to increase the pressing force. On the other hand, set the protrusion height of the rotation prevention claw smaller than the protrusion height of the separation prevention claw, or set the total length of the rotation prevention claw to more than the total length of the separation prevention claw. If it is set short, the bite resistance of the anti-rotation pawl is small, so even if the tightening torque of the bolt is not increased by a large amount, the anti-separation pawl will bite to a sufficient depth in the initial state, which reduces workability. There is no fear. Further, since it is not necessary to increase the tightening force, that is, the pressing force, to a great extent, there is no possibility of damaging the lining on the inner surface of the pipe.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention.
In FIG. 1 (b), the receiving portion 1 a at the end of the first fluid pipe 1
The insertion opening 2a at the end of the second fluid pipe 2 is inserted therein. A push ring (ring) 3 is provided on the outer circumference of the second fluid pipe 2.
And a seal ring 6 are attached. This push ring 3
A plurality of sets of T-shaped bolts 21 and nuts 22 are connected to the receiving portion 1a so as not to rotate and are pulled together, and the annular pressing portion 3a pushes the seal ring 6 into the receiving portion 1a. By maintaining the above state, the space between the fluid pipes 1 and 2 is sealed (sealed).

In FIG. 1A, a plurality of retaining portions 5 are provided on the push wheel 3 at equal intervals in the circumferential direction. As shown in FIG.
Recesses 51 are provided in each recess 51.
Is installed. Each of the locking pieces 4 is held in a mounted state by a fitting 11 that fits into the holes 11a and 11b formed in the push wheel 3 and the locking piece 4 of FIG. The fixture 11 is made of rubber or resin,
Allow the locking piece 4 to move within the recess 51 (FIG. 1 (b)).

In FIG. 2, a cam surface 41 is formed on the outer peripheral side of the locking piece 4 so that the locking piece 4 has a wedge shape. The cam surface 41 is a taper surface that moves away from the outer surface 2b of the second fluid pipe 2 as it goes to the insertion opening 2a of the second fluid pipe 2. On the other hand, a push bolt 7 which is a separate body from the locking piece 4 is screwed into the retaining portion 5 of the push wheel 3, and the tip end surface 71 of the push bolt 7 projects into the recess 51 to allow the cam surface 41 to move.
Is in contact with. The push bolt 7 is
The cam surface 41 of the locking piece 4 is pressed to apply a pressing force to the locking piece 4 in the radially inward direction P of the second fluid pipe 2 and in the anti-extraction direction S1.

FIG. 3 shows the bottom surface of the locking piece 4. Figure 3
In (a), the pipe circumferential direction R is provided on the bottom surface of the locking piece 4.
A pair of separation preventing claws 42, 42 each having a long ridge,
The rotation-preventing claw 43, which is a long protrusion in the tube axis direction S,
Each is linearly formed. Both claws 42, 4
3 has, for example, a mountain-shaped sharp cross section. In addition,
The surface of the locking piece 4 including both the claws 42 and 43 is subjected to quenching treatment and tempering treatment.

The separation preventing claw 42 is formed over the entire length of the locking piece 4 in the tube circumferential direction R. The disengagement preventing claw 42 receives the pressing force by the axial force of the pressing bolt 7 of FIG. 1B and digs into the outer surface 2b of the second fluid pipe 2 so that the second fluid pipe 2 has a shaft axis. By engaging in the direction S, the two fluid pipes 1 and 2 are prevented from separating from each other.

As shown in FIG. 3B, the rotation preventing claw 43 is formed in a part of the locking piece 4 in the tube axis direction S, and has blade portions 43a at both ends in the tube axis direction S. is doing.
The rotation preventing claw 43 receives the pressing force and bites into the outer surface 2b (FIG. 1) of the second fluid pipe 2 so that the second
By engaging the fluid pipe 2 in the circumferential direction R, both fluid pipes 1,
2 prevent each other from rotating in the circumferential direction R of each other.

Next, the operation of preventing separation of the fluid pipe will be described. As shown in FIG. 1 (b), by tightening the push bolt 7, the locking piece 4 moves to the inner side P in the radial direction of the second fluid pipe 2 and the insertion port 2 a side, and the both pawls are moved. 42,43
Bites into the outer surface 2b of the second fluid pipe 2. By this bite, the separation preventing claw 42 prevents the two fluid pipes 1 and 2 from separating, while the rotation preventing claw 43 prevents the both fluid pipes 1 and 2.
Are prevented from rotating relative to each other in the tube circumferential direction R (FIG. 1A). When the two fluid pipes 1 and 2 start to come out a little due to the unequal settling or the pulling force due to the internal pressure, the locking pieces 4 move slightly in the withdrawing direction S2 together with the second fluid pipe 2. However, at this time, the locking piece 4 moves along the inclination of the cam surface 41. Therefore, both claws 42, 43
Penetrates deeper into the outer surface 2b of the second fluid pipe 2,
The separation prevention force and the rotation prevention force increase.

In the above-mentioned structure, since the separation preventing device is provided with the rotation preventing claw 43, not only the relative rotation of the fluid pipes 1 and 2 in the pipe circumferential direction R (FIG. 1A) is prevented, but also , The contact state between the tip surface 71 of the push bolt 7 and the cam surface 41 in FIG. 2 does not change, and therefore the detachment preventing claw 42 is
The intended state in which the fluid pipe 2 is bitten can be maintained. Therefore, the separation preventing force in the tube axis direction S does not decrease. Since the contact state between the tip surface 71 of the push bolt 7 and the cam surface 41 does not change, the tightening work of the push bolt 7 is unnecessary.

By the way, when the rotation preventing claw 43 is provided,
The initial depth of biting of the separation preventing claw 42 due to the tightening force of the push bolt 7 may be smaller than in the conventional case. Therefore, it becomes necessary to increase the tightening torque of the push bolt 7. Here, in this embodiment, the rotation preventing claw 43 is not provided over the entire length of the locking piece 4, but is provided in a part thereof to be shortened. That is, the total length of the rotation preventing claws 43 is set shorter than the total length of the separation preventing claws 42 in FIG. Therefore, since the resistance of the rotation preventing claw 43 at the time of biting is small, the separation preventing claw 42 bites to a predetermined depth without increasing the tightening torque of the push bolt 7. As a result, the inconvenience of significantly lowering workability and damaging the lining on the inner surface of the pipe is unlikely to occur.

Further, in the present embodiment, since the blade portion 43a is formed at the tip of the rotation preventing claw 43, when the engaging piece 4 moves in the pipe axis direction S, the bite amount changes. Moreover, the rotation preventing claw 43 smoothly bites deep into the second fluid pipe 2 of FIG. 2 by the blade portion 43a.

Next, a modified example of both the claws 42 and 43 will be described. The rotation preventing claw 43 is, as shown in FIG.
It may be provided over substantially the entire length in the tube axis direction S on the bottom surface of the locking piece 4. Further, as shown in FIG. 4B, the rotation preventing claws 43 may be two or three or more. further,
The rotation preventing claw 43 does not need to be a long ridge in the tube axis direction S, and may include a component in the tube axis direction S as shown in FIGS. 4C and 4D. The claw 43A shown in FIGS. 4 (c) and 4 (d) serves both to prevent separation and to prevent rotation. Therefore, as shown in FIG. 4D, only the dual-purpose claw 43A including the component in the pipe circumferential direction R and the component in the pipe axial direction S is locked by the locking piece 4.
May be provided.

By the way, in the first embodiment described above, both the pawls 42, 43 or the combined pawl 43A are provided on all the locking pieces 4 so that the respective locking pieces 4 have the same shape. Therefore, since the number of types of parts does not increase, manufacturing and maintenance of the locking piece 4 become easy.

However, in the present invention, it is not always necessary to provide both the pawls 42 and 43 on all the locking pieces. For example,
It is also possible to provide only the separation preventing claws 42 on all the locking pieces and provide the rotation preventing claws 43 on some of the locking pieces. Further, as shown in FIG. 4 (e), only the rotation preventing claws 43 may be provided on some of the locking pieces 4A, and only the conventional separation preventing claws 42 may be provided on the other locking pieces.

Next, another modified example of the rotation preventing claw 43 will be described. The protrusion height of the rotation preventing claw 43 may be set to be the same as the protrusion height of the separation preventing claw 42, but is set lower than the protrusion height of the separation preventing claw 42 as shown in FIG. 5A. You may. In this way, when the protrusion heights of the both claws 42 and 43 are made different, the bite amount of the both claws 42 and 43 becomes larger in the separation preventing claw 42 than in the rotation preventing claw 43, so that the rotation preventing Since the resistance caused by the biting of the working claw 43 is small, the separation preventing claw 42 bites into a predetermined depth without increasing the tightening torque of the push bolt 7 by a very large amount.

Further, as shown in FIGS. 5 (b) and 5 (c), the height of the rotation preventing claw 43 gradually decreases as it goes toward the insertion side S1 in the tube axis direction or the opposite direction. You may set it.

By the way, in the first embodiment, the locking piece 4
Although the case where the locking piece 4 has a wedge shape has been described, the locking piece 4 does not necessarily have to have a wedge shape in the present invention. An example thereof is shown in the second embodiment of FIG. In the following examples,
The same or similar parts as those of the first embodiment are designated by the same or similar reference numerals, and detailed description and illustration thereof will be omitted.

In FIG. 6, the locking piece 4B has an arcuate cam surface 41B formed on the outer peripheral side thereof. Locking piece 4
On the bottom surface of B, the separation preventing claw 42 and the rotation preventing claw 4 are provided.
3 is formed. The recess 51 has a groove shape along the circumferential direction of the second fluid pipe 2. On the other hand, the locking piece 4B is the second
The fluid pipe 2 has an arc shape along the circumferential direction, and is pressed radially inward P by one or a plurality of push bolts 7. When a pulling force acts on both fluid pipes 1 and 2, and both fluid pipes 1 and 2 (FIG. 1) start to come out, the locking piece 4B is
The cam surface 41B is slightly rotated in the direction of arrow E along the arc of the cam surface 41B, and this rotation causes the detachment preventing claw to bite deeply into the outer surface 2b of the second fluid pipe 2 (actual 4- See column 5, line 2 to column 6, line 30 of JP 10470).

In the meantime, although each of the above embodiments has been described as an example applied to a mechanical joint, the present invention can also be applied to a joint portion of a T-type ductile cast iron pipe and the like. Further, it is not always necessary to provide the cam surface. An example thereof will be briefly described with reference to the third embodiment shown in FIGS. 7 and 8.

The retaining ring body (ring) 3A shown in FIG. 7 is provided with a locking piece 4C in the recess 51 shown in FIG. Inner peripheral portion of the retaining ring body 3A and the locking piece 4C
In both, the detachment prevention claw 42 and the rotation prevention claw 43 are provided.
Are formed. The retaining ring body 3A has a connecting portion 31 protruding in the tube axis direction S.
The stop bolt 32 and the hook 33 screwed into the
It is connected by being engaged with the collar portion 1b of the receiving portion 1a of the die tube. In addition, a rotation preventing claw 32a at the tip of the depression is integrally formed at the tip of the stop bolt 32.

By the way, in each of the above embodiments, the recess 51 is formed in the inner peripheral portion of the ring 3, 3A connected to the first fluid pipe 1, but in the present invention, it is not always necessary to do so. For example, as shown in the fourth embodiment of FIG. 9, the first fluid pipe 1
The retaining portion 5 is formed integrally with the receiving portion 1a of the
The recess 51 may be formed in the recess. The detailed structure of the fourth embodiment is disclosed in JP-B-4-10471, column 4, line 39 to column 6, line 8.

By the way, in each of the above embodiments, the push bolt 7
Although the axial direction is set to the radial direction of the pipe or to be oblique, in the present invention, the axial direction of the bolt may be set to the pipe axial direction (see, for example, Japanese Utility Model Publication No. 3-36785). Further, an intermediate piece may be provided between the locking piece 4 and the push bolt 7. Further, the push bolt 7 may be screwed into the locking piece 4 and the locking piece 4 may be mounted in the recess 51 (actually disclosed in Japanese Utility Model Laid-Open No. 52-164).
721). In addition, the retaining ring body 3A of FIG.
May be divided into two in the circumferential direction, and the two retaining ring main bodies may be fastened with bolts to generate the pressing force.

[Brief description of drawings]

FIG. 1 (a) shows a first embodiment of the present invention, I of FIG. 1 (b).
FIG. 6A is a sectional view taken along the line a-Ia, and FIG.

FIG. 2 is a cross-sectional view showing a main part of the present invention.

FIG. 3A is a perspective view seen from the bottom side of the locking piece,
(B) is a bottom view of the locking piece.

FIG. 4 is a bottom view showing a modified example of the locking piece.

FIG. 5 is a cross-sectional view showing a modified example of the rotation preventing claw of the locking piece.

FIG. 6 is a cross-sectional view showing the main parts of the second embodiment.

FIG. 7 is a sectional view taken along line VII-VII in FIG. 8 showing a third embodiment.

8 is a sectional view taken along line VIII-VIII of FIG.

FIG. 9 is a cross-sectional view showing the main parts of the fourth embodiment.

FIG. 10 is a diagram showing the cause of rotation of the fluid pipe in the pipe circumferential direction.

[Explanation of symbols]

 1: 1st fluid pipe 1a: Receptacle part 2: 2nd fluid pipe 2a: Insertion part 2b: Outer surface 3,3A: Ring 4-4C: Locking piece 6: Seal ring 7: (Push) bolt 42: Detachment prevention claw 43: Rotation prevention claw 43A: Combined claw 51: Recess

Claims (5)

[Claims] 1. An insertion portion of a second fluid pipe is inserted into a receiving portion of the first fluid pipe, and a seal ring attached to the outer periphery of the second fluid pipe seals between the two fluid pipes. A ring that is connected to the receiving port and is attached to the outer circumference of the second fluid pipe or a recess is provided in the inner peripheral part of the receiving port so that the ring engages with the outer surface of the second fluid pipe. A stop piece is attached to the recess, and a pressing force directed at least inward in the radial direction of the pipe is applied to the locking piece by a bolt that is separate from the locking piece. The disengagement preventing claw formed of a long ridge is provided on one or more of the locking pieces, and the disengagement preventing claw is bitten into the outer surface of the second fluid pipe by the pressing force. The fluid pipe is prevented from separating from each other by engaging it with the pipe axial direction. In the stop device, one or more of the locking pieces is formed of a long ridge in a direction including a component in the axial direction of the pipe, and receives the pressing force to bite into the outer surface of the second fluid pipe. A device for preventing separation of a fluid pipe, characterized in that a rotation preventing claw is provided for preventing the two fluid pipes from rotating in the pipe circumferential direction by engaging with the fluid pipe in the pipe circumferential direction. 2. The device for preventing separation of a fluid pipe according to claim 1, wherein all the locking pieces are provided with the both claws, and the shapes of the locking pieces are set to be the same. 3. The device for preventing separation of a fluid pipe according to claim 1, wherein all the locking pieces are provided with the separation preventing claws, and some of the locking pieces are provided with the rotation preventing claws. 4. The separation preventing device for a fluid pipe according to claim 1, 2 or 3, wherein the protrusion height of the rotation preventing claw is set smaller than the protrusion height of the separation preventing claw. 5. The method according to claim 1, 2, 3, or 4,
A fluid pipe separation prevention device, wherein the total length of the rotation prevention claws is set to be shorter than the total length of the separation prevention claws.