JP3531147B2 - Pipe separation prevention device and plastic ring for union nut joint - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system in which an end portion of a joining pipe having no screw is inserted into a receiving portion of a pipe or a joint body, and a union nut is fastened with a rubber packing interposed. The present invention relates to a pipe separation prevention device for an expansion and contraction flexible pipe joint and a plastic ring used for the device.

[0002]

2. Description of the Related Art In addition to its simple and inexpensive point, such a pipe joint with no thread at the pipe end has the flexibility of expansion and contraction at the joint portion, and the vibration, elongation and strain of the pipe due to this. Since it has an excellent protection function that absorbs etc. well, it has a nominal diameter of 13
It has been used favorably in the joining method of low-pressure pipes having a relatively small diameter of -50 mm and a normal pressure of up to about 0.5 N · m.

However, in the conventional pipe joint, the holding force of the rubber packing with respect to the joint pipe is determined according to the tightening force of the union nut at the time of joining work, so that it is necessary to strongly tighten it with a large pipe wrench or the like in a place where pressure is applied. there were.
In addition, if rust-preventing oil, oil during screw cutting, etc. adheres to the pipe, the force to hold the joint pipe is extremely reduced and it is extremely difficult to reliably prevent the joint pipe from coming off. Met. Therefore, in the past, in the state where the joint pipe and the pipe joint main body can be flexibly expanded and contracted, a pipe disengagement prevention metal fitting has been developed to prevent the metal pipe from coming off, and is attached to the pipe joint portion.

However, the conventional pipe disengagement prevention metal fittings cannot fully exhibit stretchability and flexibility, and there is a conflicting problem that if one function is secured, the other function is sacrificed. It was In addition, when trying to secure expansion and contraction flexibility, the length of the entire joint becomes long, and the drawback that it cannot be used in a narrow area and the number of bolt fastening operations increase,
There were drawbacks such as very troublesome work. Furthermore, in the case of the conventional pipe disengagement prevention fitting, it is necessary to temporarily assemble it at the factory shipment stage, disassemble it on site, and then assemble it again so that it does not get lost because it is necessary to assemble each part as a set. Yes, it was a tedious task.

The present applicant has already applied for the technology of Japanese Patent Application No. 6-111647 shown in FIGS. 6 (A) and 6 (B) as a solution to the above-mentioned drawbacks of the conventional pipe detachment prevention fitting. Already done. Pipe disconnection prevention fitting 1 according to this prior application technology
Is a retaining ring 2 as a retaining ring that is notched in the middle of the circumference,
A bolt 4 and a nut 5 for fastening the retaining ring 2 onto the outer peripheral surface of the joint pipe 3, a circular locking ring 6, and two arms 7, which connect the retaining ring 2 and the locking ring 6. 7 and 7.

As is apparent from FIG. 6B, the retaining ring 2 has a C-shape with a notch on the circumference, and is externally fitted to the joint pipe 3. On the other hand, the circular locking ring 6
The insertion hole 10 has a size larger than the outer diameter of the joint body 8 and smaller than the outer diameter of the union nut 9.
The retaining ring 2 and the locking ring 6 are connected by two upper and lower arms 7, 7, and the other space between the retaining ring 2 and the locking ring 6 should be inserted with a tool or the like. It is a free space 11 where you can play. Further, the inner peripheral surface of the retaining ring 2 is formed with an uneven portion for preventing slippage. The inner diameter between the arms 7 and 7 is set larger than the maximum outer diameter of the tool mounting portion of the union nut 9.

Thus, the arm 7 in this prior application technique,
7, the connection with the retaining ring 2 is performed in a loose state, and the connection with the locking ring 6 is integrally connected and fixed. That is,
Hooks 13, 13 projecting in the inner diameter direction are formed at the tips of the arms 7, 7 on the snap ring 2 side, and flanges 14, 15, 16 are formed on the outer peripheral surface of the snap ring 2 correspondingly. A recess 17 is formed between these flanges 14, 15 and 16. The flange 14 is circumferentially formed on the end surface of the retaining ring 2 near the union nut 9, and the flanges 15 and 16 are the annular flange 1 described above.
It is provided continuously from 4 in the direction parallel to the axis. The hooks 13, 13 of the arms 7, 7 are fitted in the recesses 17 of the retaining ring 2 in a loosely fitted state.

The pipe disengagement prevention fitting 1 according to the prior art is
When shipped from the factory, the retaining ring 2, the locking ring 6 and the arms 7 and 7, the packing 12 and the union nut 9 are used.
And the joint body 8 may be assembled into one set. After being assembled in the set state, each of these parts will not fall apart. At the time of construction,
As shown by the chain line in FIG. 6A, the pipe end of the joint pipe 3 is inserted from the snap ring 2 side. Then, the pipe end of the joint pipe 3 passes through the union nut 9 and the packing 12 attached to the union nut 9 and is positioned inside the joint body 8. Next, the union nut 9 may be tightened with a tool, and finally, the bolt 4 and the nut 5 of the snap ring 2 may be tightened to fix the snap ring 2 to a predetermined position on the outer peripheral surface of the joint pipe 3.

As described above, the pipe detachment preventing metal fitting 1 according to the prior application of the present applicant can be assembled in a factory and shipped in a temporarily tightened set state, and can be directly installed on site without disassembling it. It is possible and convenient. Moreover,
When a force in the deviating direction acts on the joining pipe 3, one end side of the arms 7, 7 engages with the end face of the union nut 9, and the other end side of the hooks 13, 13 engage with the flanges 14, 14 of the snap ring 2. Therefore, the joint pipe 3 is structured so as not to come off.

Furthermore, the applicant of the present invention has applied for a technique of the pipe detachment prevention fitting 28 for a union nut joint shown in FIG. 7 in Japanese Patent Application No. 9-34.
No. 712 has already been filed. This metal fitting 28 is
The use of the locking ring 6 of the prior application shown in FIG. 6 is abolished, the union nut 9 and the arm 7 are integrally connected, and the snap ring 2 is provided between the hook 13 at the tip of the arm and the end surface of the union nut 9. Is to be located.

[0011]

However, the pipe disengagement prevention fitting 1 according to the prior application technique shown in FIG. 6 of the present applicant is assembled in a factory and shipped in a temporarily tightened set state, which is not disassembled into pieces. However, the retaining ring 2, the union nut 9, and the unit such as the joint body 8 are only temporarily fixed through the locking ring 6 and the arm 7. Therefore, at the time of construction at the site, the center of the retaining ring 2 is displaced downward by the amount of play of the locking ring 6 and the arm 7 in the lower part of FIGS. 6A and 6B, and the joining pipe 3 is inserted. There was a drawback that I couldn't do well. Therefore, it is necessary to support the retaining ring 2 from below and align its center position with the center positions of the union nut 9, packing 12, etc., and then insert the joint pipe 3, which makes the centering work troublesome. won.

Further, in the prior application of the applicant shown in FIG. 6, there is no problem if the joint pipe 3 is a hard pipe such as a hard vinyl chloride pipe or a steel pipe, but the joint pipe 3 Is a soft tube such as a soft polyethylene tube,
Moreover, in the case of a small diameter tube having a diameter of 30 mm or less, there were the following drawbacks. That is, the union nut 9 must be fastened by inserting a spanner, a pipe wrench, or the like between the arms 7 and 7, but the arms 7 and 7 cover the outer peripheral surface of the union nut 9. Moreover, because of the small diameter pipe, the distance between the arms 7, 7 is extremely narrow, and tools such as the spanner and pipe wrench are
However, there was a problem in that the fastening operation could not be performed smoothly due to interference with No. 7.

In addition to this, the hand-tightening work of the union nut 9 at the beginning of the work also interferes with the arms 7 and 7,
It had the drawback of being difficult to do. Furthermore, the locking ring 6
The defect rate is high, it is difficult to cast, and as a result, it is expensive.

On the other hand, according to the prior application of the applicant shown in FIG. 7, when the union nut 9 is retightened with a pipe wrench or the like, the tightening bolt 4 and the nut 5 of the retaining ring 2 are together with the union nut 9. Since it rotates, in the case of joining work in a narrow place, it may stop at a position invisible to the operator, and it is necessary to manually tighten the bolts 4 and the nuts 5. In addition, in some cases, tightening may be forgotten, and it is difficult to reliably confirm the completion of the construction work visually, and there was concern about whether or not the original function of preventing pipe detachment was achieved. For example, in a narrow place such as a wall where a spanner as a tightening tool does not enter,
After further tightening the union nut 9 with the pipe wrench, the retaining ring 2 must be rotated to the front side and the bolt 4 and the nut 5 should be tightened with a spanner, resulting in extremely poor workability.

[0015]

SUMMARY OF THE INVENTION The present invention is a further improvement of the technique previously filed by the present applicant in view of the above-mentioned problems of the prior art. It is easy to insert a joining pipe, and a spanner or a pipe wrench. A tool for preventing pipe separation that has a function of expansion and contraction that allows the bolts and nuts of the snap ring to be set at the optimum position for tightening without interference with tools such as tools, and the plastic ring used for this. Is intended to be provided.

In order to solve the above-mentioned problems, the means of claim 1 adopted by the present invention is to insert a non-threaded joint pipe into a pipe or a joint body having a receiving portion in which an external thread is engraved on the outer peripheral surface,
In a pipe joint with a structure in which an annular rubber packing is inserted and fitted to screw the union nut into the socket, it is cut out in the middle of the circumference and is externally fitted to the joint pipe on the rear end side of the union nut. A retaining ring that is mounted and tightened by bolts and nuts, an arm that is integrally formed with the retaining ring and that engages with an annular recess provided in the union nut, and an external fitting fit in the annular recess of the union nut. And a plastic ring for holding the arm, which is a pipe detachment preventing device for a union nut joint.

According to the present invention, the arm of the snap ring can be held in a state where the plastic ring is externally fitted and attached to the annular recess of the union nut. Since the plastic ring can be externally attached using self-elasticity,
There is no need to provide play. Therefore, the center position of the snap ring can be held without being displaced, and the work of inserting the joining pipe at the site is easy. In addition, since the union nut and the snap ring can rotate freely, it is possible to bring the position of the bolt and nut of the snap ring to the optimum position no matter where the union nut stops.

According to a second aspect of the present invention, the union nut joint according to the first aspect is characterized in that the annular recess is formed at a position closer to the joint pipe, and the nut portion is exposed to the outside. It is a pipe separation prevention device. Since the nut portion of the union nut is exposed to the outside, the tool does not interfere with the arm or the like, and the fastening work is easy.

The means of claim 3 adopted by the present invention is formed in an annular shape from a resin material such as polyethylene, has a plurality of retaining projections on the inner peripheral surface side, and has a middle portion on the circumference. A plastic ring for a union nut joint, in which a holding pocket portion that is externally fitted and engaged with an arm portion of a retaining ring is formed. In this plastic ring, the protruding piece abuts on the bottom surface of the annular recess in a state where the plastic ring is fitted onto the annular recess of the union nut, and the center of the plastic ring coincides with the center of the union nut. Therefore, when the pocket of the plastic ring is engaged with the arm of the snap ring to hold the snap ring, the center of the snap ring will be aligned with the center position of the union nut, etc. is there.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the embodiments shown in the drawings. The same reference numerals as in the conventional case are the same members. 1 to 4 show a pipe separation prevention device 18 for a union nut joint according to an embodiment of the present invention. In this pipe detachment prevention device 18, arms 21 and 21 for connecting a retaining ring 19 and a union nut 20 are integrally cast on the retaining ring 19. The snap ring 19 has a C shape in which a part of the circumference is cut out, and the arms 21 and 21 are arranged in pairs at the opposite positions on the circumference of the snap ring 19 and have a pair of tips. A hook 22 protruding in the inner diameter direction is formed on the inside.

In this way, the arms 21 and 21 are connected to the snap ring 19
By integrally casting with, it is possible to omit the conventional locking ring 6 shown in FIG. 6, and since its manufacture can be performed at the same time as the manufacture of the snap ring 19, it is possible to carry out the casting operation. Can be omitted. In addition, retaining ring 1
On the inner peripheral surface side of 9, there is formed a serrated anti-slip portion 19a for improving the biting of the joint pipe 3 (see FIG. 6) into the outer peripheral surface.

On the other hand, an annular recess 23 for engaging with the hook 22 of the arms 21, 21 is formed on the end face side of the union nut 20 with respect to the joint pipe 3. The inner diameter of the hook 22 is set to be smaller than the outer diameter of the end surface-side convex portion 24 forming the annular recess 23 and larger than the outer diameter of the annular recess 23.

In this embodiment, the annular recess 23 of the union nut 20 is fitted in the annular recess 23 shown in FIG.
Also, the plastic ring 25 shown in FIG. The plastic ring 25 is formed of a synthetic resin material such as hard polyethylene that can be repeatedly used in the shape of a flat plate, and has protruding pieces 26 protruding in the inner diameter direction at a plurality of locations (6 locations in the drawing) on the inner peripheral surface side. The pocket portion 2 is formed on the circumference of the arm 21, 21 and is fitted to the hook 22 of the arm 21, 21 at a position opposite to the arm 21, 21, and holds the same.
7, 27 are formed. The inner diameter of the body portion of the plastic ring 25 is set to be larger than the outer diameter of the projection 24 near the end surface of the union nut 20,
The inner diameter dimension of the protruding piece 26 is set smaller than the outer diameter dimension of the end face side protruding portion 24, and is set to be equal to or about the same as the outer diameter dimension of the annular recess 23.

The pipe detachment preventing device 18 for the union nut joint thus constructed is cast and molded in a factory, then temporarily assembled and shipped in this state. The temporary assembly is
First, the plastic ring 25 is externally mounted on the annular recess 23 of the union nut 20. At this time, the inner diameter dimension of the protruding piece 26 of the plastic ring 25 is set smaller than the outer diameter dimension of the end surface-side protruding portion 24 of the union nut 20, and the protruding piece 26 moves in the opposite direction to the mounting direction. The tip end side elastically deforms to get over the convex portion 24, and the annular concave portion 23
After reaching the point, it returns to itself and contacts the bottom surface of the annular recess 23. Therefore, the plastic ring 25 coincides with the axial center line of the union nut 20 or the like after being externally fitted and mounted in the annular recess 23 of the union nut 20.

Next, the retaining ring 19 in which the bolts 4 and the nuts 5 are temporarily tightened is prepared, and the hooks 22 on the tip ends of the arms 21 and 21 integrally formed with the retaining ring 19 have annular recesses in the union nut 20. It is arranged so as to be located directly above 23. Then, from this state, the retaining ring 19 is lowered in the direction perpendicular to the paper surface of FIG. 1, and the hook 22 at the tip of the arm is engaged with the annular recess 23 of the union nut 20. After that, the pockets 27, 2 of the plastic ring 25
7 is elastically deformed in the direction indicated by symbol A in FIG. 1, and the hook portions 22 at the ends of the arms are deformed.
To fit inside. After fitting, the pockets 27, 27 are released and returned by self-elasticity to fit the pockets 27, 27 on the hook 22 at the tip of the arm, and the retaining ring 19 is fitted on the pockets 27, 27. Try to hold. In this way, the loading of the retaining ring 19 is a simple work of merely lowering it from above, and can be performed easily and quickly. As a result, even if the hand is released from the retaining ring 19, the pocket portion 27 of the plastic ring 25,
Since it is held by 27, the retaining ring 19 does not fall off. Further, the center line of the retaining ring 19 held by the plastic ring 25 coincides with the axial center line of the pipe joint.

Next, the packing 12 is inserted into the inner peripheral surface side of the union nut 20, and the whole of these is screwed to the joint body 8. That is, the union nut 20 is screwed onto the screw portion formed on the outer peripheral surface of the joint body 8. In addition, packing 1
The charging of No. 2 may be performed before charging the snap ring 19 into the union nut 20, or may be performed either way. As a result, the temporary assembly of the tube detachment prevention device 18 is completed, and it is shipped from the factory in this state. In this temporarily assembled state, the respective members that form the pipe joint do not come apart.

At the construction site, the joining pipe 3 is inserted into the pipe detachment prevention device 18 in the temporarily assembled state. For the insertion, insert the insertion port on the front end side of the joining pipe 3 into the snap ring 19 and the union nut 2.
0, it is inserted into the packing 12 and reaches the inside of the joint body 8. After that, after confirming that the union nut 20 is tightened with a spanner or a pipe wrench to the minimum tightening torque required for watertightness, a position where the fastening portion of the retaining ring 19 is easily tightened (the fastening portion is moved upward). It is rotated with the tightening so that it comes to the position (1), and then the retightening is performed. Finally, the snap ring 19 is fastened. For fastening the retaining ring 19, after determining the axial positioning with respect to the joint pipe 3 and the direction of the bolt fastening portion (positioning upward as shown in FIGS. 1 to 3), the bolt 4 and the nut 5 are fastened. It is sufficient to perform full tightening so that the saw teeth 19a formed on the inner peripheral surface of the retaining ring 19 bite into the outer peripheral surface of the joint pipe 3 so as to exert a slip preventing function. As a result, the joint pipe 3 can expand and contract within a range in which the hook 22 can move in the annular recess 23.

Further, the pipe detachment prevention device 18 for the union nut joint can be temporarily assembled by utilizing the plastic ring 25 as it is, even if it is disassembled and reassembled after the construction, and it is repeatedly used. Is possible.
Therefore, it is extremely effective as temporary equipment at the time of disaster where repeated use is expected.

By the way, the present invention is not limited to the above-described embodiment, and, for example, the number, shape and position of the pocket portions 27 of the plastic ring 25 may correspond to the number and shape of the hooks 22 installed. The bolts 4 and the nuts 5 may be appropriately changed so as to be provided at positions on the opposite side that do not interfere with the positions of the bolts 4 and the nuts 5. Also plastic ring 2
The number of the protruding pieces 26 for retaining of 5 may be any number that can realize retaining, and the shape of the protruding pieces 26 may be a continuous corrugated shape, partially formed, It is possible to make appropriate changes such as simply forming notches in a continuously formed product.

[0030]

As described above, according to the present invention,
Insert a threadless joint pipe into a pipe or fitting body that has a receiving part with an external thread engraved on the outer peripheral surface, insert a ring-shaped rubber packing into it, and screw a union nut into the receiving part. In a pipe joint with a structure, a stop ring that is cut out in the middle of the circumference and is externally fitted to a joint pipe on the rear end side of the union nut and tightened with bolts and nuts, and is integrally formed with the stop ring And an arm that engages with the annular recess provided in the union nut, and a ring made of plastic that is externally fitted and attached to the annular recess of the union nut, and holds the arm. It is possible to hold the arm of the snap ring while being fitted onto the annular recess of the union nut.

Since the plastic ring can be externally fitted and attached by utilizing self-elasticity, it is not necessary to provide a play. Therefore, the center position of the snap ring can be held without being displaced, and the joining pipe can be inserted on-site in the state of temporary assembly at the factory, and the workability is extremely excellent. . Further, even in a narrow place, the snap ring can be tightened by directly checking the snap ring while rotating it to a position where it is easy to tighten, and it is possible to prevent forgetting to tighten. Further, it is possible to visually confirm the completion of tightening, and it is possible to improve the certainty of preventing the tube from coming off.

Further, in the union nut of the present invention, since the annular concave portion is formed at a position closer to the joint pipe and the nut portion is exposed to the outside, the tool does not interfere with the arm or the like,
The fastening work is easy.

Further, the plastic ring for the union nut joint of the present invention is formed in an annular shape from a resin material such as polyethylene, and has a plurality of protrusion-preventing protrusions on the inner peripheral surface side for preventing slippage. A pocket portion for holding that is externally fitted and engaged with the arm portion of the retaining ring is formed midway. This allows the protruding piece to come into contact with the bottom surface of the annular recess in a state where the union nut is fitted onto the annular recess, and the center of the plastic ring can be aligned with the center of the union nut.
Therefore, when the pocket of the plastic ring is engaged with the arm of the snap ring to hold the snap ring, the center of the snap ring will be aligned with the center position of the union nut, etc. is there. Further, unlike the conventional case, since there is no need for a locking ring that has a high defective rate and is difficult to cast, there is an advantage that a product can be provided at low cost.

[Brief description of drawings]

FIG. 1 is a plan view of a pipe separation prevention device according to an embodiment of the present invention.

FIG. 2 is a side view of the tube separation prevention device according to the embodiment of the present invention.

FIG. 3 is a front view of a pipe separation prevention device according to an embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing a half of a pipe separation prevention device according to an embodiment of the present invention.

5A and 5B show a plastic ring according to an embodiment of the present invention, where FIG. 5A is a front view and FIG. 5B is a bottom view.

6A and 6B show a conventional pipe disengagement preventing metal fitting, in which FIG. 6A is a semi-longitudinal sectional view thereof, and FIG. 6B is a front view showing a state after fastening.

FIG. 7 shows another conventional pipe detachment prevention metal fitting,
Figure (A) is a semi-longitudinal sectional view thereof, and Figure (B) is a front view showing a state after fastening.

[Explanation of symbols]

3 ... Joined pipe, 4 ... Bolt, 5 ... Nut, 18 ... Pipe separation prevention device, 19 ... Snap ring, 20 ... Union nut, 21 ... Arm, 22 ... Hook, 23 ... Annular recess, 25 ... Plastic ring, 26 ... Projection piece, 27 ... Pocket section

Claims (3)

(57) [Claims] 1. A pipe having a socket having an external thread engraved on the outer peripheral surface thereof, or a joint body, into which a threadless joint pipe is inserted, and an annular rubber packing is inserted and inserted to insert the union nut into the socket. In a pipe joint having a structure that is screw-fastened to, a snap ring that is cut out in the middle of the circumference and externally fitted and attached to a joint pipe on the rear end side of a union nut, and that is fastened by a bolt and a nut, And an arm that is integrally formed with the union nut and that engages with the annular recess provided in the union nut, and a plastic ring that is externally fitted and attached to the annular recess of the union nut and that holds the arm. Tube separation prevention device for union nut joints. 2. An annular recess is formed at a position closer to the joint pipe,
The pipe detachment prevention device for a union nut joint according to claim 1, wherein the nut portion is exposed to the outside. 3. An annular fitting made of a resin material such as polyethylene, having a plurality of retaining protrusions on the inner peripheral surface side, and fitting to the arm portion of the retaining ring in the middle of the circumference. A plastic ring for a union nut joint that has a retaining pocket that fits.