JPH07107433B2 - Corrugated pipe joint structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrugated pipe joint, and more particularly to a corrugated pipe made of plastic.

[0002]

2. Description of the Related Art A corrugated pipe is a general term for pipes in which annular or spiral reinforcing ribs are regularly provided on the outer peripheral surface of the pipe, but the deformation resistance due to an external force is significantly improved over that of a straight pipe. Therefore, it has been put to practical use in many industrial fields. The present invention relates to a novel structure, among them, which has extremely excellent characteristics, particularly as a joint for a corrugated pipe made of plastic.

FIG. 8 shows a conventional technique disclosed in Japanese Utility Model Laid-Open No. 55-7500. An elastic cylinder 101 having a corrugated inner surface and a straight cylindrical outer surface matching the corrugated corrugations on the outer peripheral surface of the corrugated tube 1a is fixed by adhering the end surface thereof to the end surface of the corrugated tube or slightly protruding. It consists of a composition. As a result, the difficulty of continuously corrugating the corrugated pipe joints is eliminated, and it is sufficient to simply butt the corrugated pipes together and fasten them with a steel plate band 102 and fasten them with bolts 103, which is extremely easy. It claims to be able to connect.

FIG. 9 shows a conventional technique proposed in Japanese Utility Model Laid-Open No. 1-139191, which is a flexible plastic integrally formed at one end of a plastic pipe (corrugated pipe in the embodiment) 1b. The end portion of another corrugated tube is inserted into the sleeve 104 made of steel, and the sleeve 104 is clamped and fixed by the binding tool 105. With the above configuration, depending on the accuracy of the inner diameter of the sleeve and the outer diameter of the corrugated tube to be inserted, the water sealing action is superior or inferior, elements that may cause water leakage are removed, and some flexibility at the joint part is eliminated. Also holds that

FIG. 10 is a vertical sectional front view showing still another conventional technique. Corrugated pipes 1c are abutted against each other, and rubber rings 3c are fitted into the recesses 11c of the corrugated pipes, respectively, and a joint 2c for covering the abutted portions. It is a method of covering and joining. As described above, corrugated pipes have irregularities on the outer peripheral surface, so a joint structure that solves the problems different from ordinary straight pipes is required, and various improvements aiming at the simplest joining work possible. Has been added.

[0006]

In the prior art shown in FIG. 8, it is necessary to manufacture an elastic cylinder having the same shape as the unevenness of the outer peripheral surface of the corrugated tube, and to prepare a mold for rubber molding. The process and its cost must be a heavy burden. In addition, it remains doubtful that the welding process itself is so simple, and it is rather thought that the process should be complicated. In addition, if a steel band is wound around the outer circumference of the corrugated pipe and the pipe is buried in the ground to fasten it with steel bolts, corrosion will proceed due to the corrosive atmosphere in the ground and the joint part will be fastened. However, there is a high risk that the water-sealing action of the pipeline will be lost due to neutralization.

In the prior art shown in FIG. 9, it is only the frictional force generated between the outer peripheral surface of the corrugated tube and the inner peripheral surface of the sleeve that maintains the joining of the corrugated tube, and the external force in the direction of pulling out the tube. It is hard to say that the resistance to prevent the departure is complete when is added. Further, it is necessary to integrally weld the sleeve onto the outer peripheral surface of the end portion of one of the corrugated pipes, which may increase the burden of manufacturing process and cost to a considerable extent.

In the prior art shown in FIG. 10, when a horizontal pulling force is applied to the conduit formed by joining the corrugated pipes, it is opposed between the outer peripheral surface of the rubber ring and the inner peripheral surface of the joint. It is only a frictional force, and there remains a great concern to adopt it as a pipeline installed in the ground. On the other hand, as a problem common to these three conventional techniques, all of the cited techniques can be carried out only when the straight pipes and the straight pipes are connected in the horizontal direction, but sometimes the pipeline may change direction. , Or T-shaped branching, the conventional technique is limited to linear joints, and it is judged that it cannot be applied as it is to other joints.

In order to solve the above-mentioned problems, the present invention can be applied as a conduit joint portion of various forms, the joining work is as simple as a straight pipe, and it is buried in the ground. Even if it aims at providing the joint structure of a corrugated pipe which is not likely to be attacked by a corrosive atmosphere.

[0010]

A joint structure for a corrugated pipe according to the present invention is a joint structure for a corrugated pipe 1 made of plastic, which is provided on the outer peripheral surface of the pipe with projections and depressions for reinforcement which are repeated at a constant pitch in the pipe axial direction. Related to plastic fittings 2
Is a straight cylinder, elbow, cheese or the like corresponding to the pipeline to be formed, and a protrusion 21 that locks the end side surface 13 of the corrugated tube is provided on the inner surface 23. The pin insertion port 22 is opened at a position corresponding to the upper part of 11A, the rubber ring 3 is interposed between another recess 11B of the corrugated pipe and the inner surface 23 of the joint, and the pin insertion port 22 is penetrated to form a plastic ring. The above problem is solved by the fact that the detachment prevention pin 4 of FIG.

Further, in the above-mentioned basic structure, a confirmation peep hole 24 is formed on substantially the same circumference as the position where the pin insertion port 22 of the corrugated tube 1 is opened, and the pin insertion port of the detachment prevention pin 4 is formed. It is extremely preferable in practice to provide a protrusion 43 for preventing slipping out at a position projecting after penetrating to 22.

[0012]

The rubber ring 3 is fitted into the first recess 11B counted from the end side surface 13 of one corrugated tube 1A, and this corrugated tube is inserted into the inner surface 23 of the joint 2. The end side surface 13 of the corrugated tube abuts on the ridge 21 projecting from the inner surface 23 of the joint, and further progress is blocked, so that the position of the corrugated tube is determined. As the corrugated pipes 1B, 1C ... Are inserted into the pipes forming the pipe lines, desired pipe lines are joined. In the state where the corrugated tube is inserted at a predetermined position, the pin insertion port 22 drilled in the joint 2 is located immediately above another recess 11A of the corrugated tube, so that the detachment prevention pin 4 is inserted from the outer surface to form the recessed portion. Fit into 11A. As a result of this configuration, when handling the corrugated pipe for pipe construction, even if an external pulling force is applied to the pipe, it does not come off because of the detachment prevention pin 4. In addition, this effect also appears when the earth's crust changes after being buried in the ground as a conduit, or when vibrations and pressure transmitted from the surface of the earth are applied, and the pipe can withstand the external force of withdrawal and leave, causing leakage. To prevent.

[0013]

FIG. 1 is a vertical sectional front view of an embodiment of the present invention.
The joint structure which joins the corrugated pipes 1A and 1B of a book horizontally is shown. It goes without saying that the joint 2 is formed in a right-cylindrical shape with no change in the outer circumference and the inner circumference, and the inner diameter thereof is set to be slightly larger than the outer diameter of the convex portion 12 of the corrugated pipe. A ridge 21 is provided around an inner surface 23 at the center of the joint 2 and abuts the end side surface 13 of the corrugated tube 1 to play a role of tube positioning. At least one pin insertion port 22 for each corrugated tube to be inserted into the joint
And in the example of this figure, the circumferential direction is evenly divided to provide four pin insertion openings 22.
At the position, the seat 25 for insertion having an increased wall thickness is provided so as to withstand the concentration of external force. The position of the pin insertion port 22 corresponds to just above the recessed portion 11A of the corrugated tube inserted to a predetermined position. This pin insertion slot 2
2 has a peep hole 24 on the same circumference as the pin insertion opening 2
Confirming whether 2 is correctly positioned on the concave portion of the corrugated pipe has a good result in improving workability and in accurately forming the conduit.

The detachment prevention pin 4 which is inserted into the pin insertion port 22 is most preferably made of a plastic material like the corrugated pipe and the joint. If all the members are made of highly corrosion-resistant plastic material, there is no need to worry about encountering a corrosive atmosphere when installed in the ground. Considering price and corrosion resistance, high density polyethylene, polypropylene, polyvinyl chloride or the like can be selected. FIG. 2 shows an embodiment in which the detachment prevention pin 4 is inserted into the pin insertion opening 22. The inner diameter of the pin insertion port 22 is a conical hole having a slope that is the minimum D at the bottom, and the detachment prevention pin 4 inserted into this pin insertion port 22 is composed of a head portion 41 and a body portion 42. The outer diameter d of 42 is smaller than the minimum inner diameter D of the pin insertion opening 22. It is a preferable example that a plurality of retaining projections 43 are provided around the outer periphery at several positions at positions where the detachment preventing pin 4 penetrates the inner surface of the joint when the detachment preventing pin 4 is inserted into the pin insertion port 22. The protrusion 43 may be a small piece composed of an upward inclined surface, and the outer diameter w thereof is the inner diameter D mentioned above.
It projects much more than. When the detachment prevention pin 4 is inserted into the pin insertion opening 22 from the outside of the joint, the protrusion 43 is pushed by the inclined surface of the pin insertion opening 22 and elastically deforms upward peculiar to plastic to pass therethrough, and after passing through. Since the external force disappears, it deforms again and returns to the original state, and plays a role of preventing the detachment prevention pin 4 from coming off. Pin insertion slot 2
2 and the detachment prevention pin 4 can be applied to other various forms, other examples of the pin insertion port 22 are shown in FIG.
Further, FIG. 4 shows other embodiments of the separation preventing pin 4, respectively.

As shown in FIG. 1, the watertightness between the corrugated pipe and the joint is achieved by fitting the rubber ring 3 into the recess 11B of the corrugated pipe. Therefore, the outer diameter of the rubber ring fitted into the corrugated tube must be set to be slightly larger than the inner diameter of the inner surface 23 of the joint. In addition, regarding the shape of the rubber ring itself, it is preferable that the cross section is bilaterally symmetrical so that the front and back are not mixed up during the joining operation.

In the joint structure of the present invention, even if the corrugated pipe needs to be removed from the joint for some reason even after the pipe line is once formed, the detachment prevention pin 4 is inserted from the pin insertion port 22. One of the features is that it can be easily removed by simply pulling it out. In the case of the cited prior art, there are many joining members, and since it is a method of tightening with bolts or the like from the outer surface, removing the rusted screw attachment is not an extremely easy work, and the advantage of the present invention is that it is obvious.
In this case, there is a concern that the projections 43 for preventing the detachment prevention pin 4 from coming off may have an adverse effect, but since the detachment prevention pin 4 has flexibility peculiar to a plastic material, for example, If a pin extraction jig 5 as shown in FIG. 5 is prepared, it can be easily removed, so there is no particular need to consider it as a problem.

FIG. 6 shows another embodiment of the present invention, which is an example of an elbow joint when the pipe is bent at a right angle. Also,
FIG. 7 shows still another embodiment, which is an example of a cheese joint in which a pipe is branched. It is needless to say that this is merely an example, and any form can be applied depending on the need of forming a duct.

[0018]

In the corrugated pipe joint structure according to the present invention, all the members exposed to the outside are made of plastic having high corrosion resistance, and there is no possibility of corrosion progress after burying, and a stable pipeline can be maintained for a long time. . The splicing work at the time of laying is simple, so the workability is high, and the degree of dependence on personal skills is small, so there is no variation in the construction of the pipe splicing and the reliability is high. In addition, it is possible to easily respond even if it is necessary to pull out the corrugated pipe from the joint for some reason, not only simply joining the pipes horizontally, but also applicable to forming various pipe lines. The effect which is not in is recognized.

[Brief description of drawings]

FIG. 1 is a front view (partial cross section) showing an embodiment of the present invention.

FIG. 2 is a detachment prevention pin 4 by (A) (B) (C).
Shows a state in which is inserted into the pin insertion opening 22.

3 (A), (B) and (C) are vertical sectional front views showing various embodiments of a pin insertion port 22. FIG.

FIG. 4 is a detachment prevention pin 4 by (A) (B) (C);
FIG. 6 is a front view (partial cross section) showing various examples of FIG.

FIG. 5 is a front view illustrating a jig for pulling out the detachment prevention pin 4.

FIG. 6 is a front view (partial cross section) showing another embodiment of the present invention.
Is.

FIG. 7 is a front view (partial cross section) showing still another embodiment of the present invention.

FIG. 8 is a front view showing a conventional technique.

FIG. 9 is a vertical sectional front view showing another conventional technique.

FIG. 10 is a vertical sectional front view showing still another conventional technique.

[Explanation of symbols]

 1 Corrugated pipe 2 Joint 3 Rubber ring 4 Removal prevention pin 5 Removal prevention pin Extraction jig 11 Recess 12 Convex 13 End side 21 Protrusion 22 Pin insertion hole 23 Inner surface 24 Peep hole 25 Insertion seat 41 Head 42 Body 43 Projection to prevent coming out D Minimum inner diameter of D pin insertion hole d Outside diameter of coming out prevention pin w Outside diameter of coming out prevention projection

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Ryoichi Nakano 1-12-19 Kitahori, Nishi-ku, Osaka-shi, Osaka Prefecture Kurimoto Iron Works Co., Ltd. (72) Sadao Nagase 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Oil Chemical company, Yokkaichi Research Institute (56) References: Showa 63-188387 (JP, U) Showa 64-27596 (JP, U)

Claims (3)

[Claims] 1. In a joint structure of a corrugated pipe 1 made of plastic, which has projections and depressions for reinforcement which are repeated on the outer peripheral surface of the pipe in the axial direction at a constant pitch, a joint 2 made of plastic is provided.
Is a straight cylinder, elbow, cheese or the like corresponding to the pipeline to be formed, and a protrusion 21 that locks the end side surface 13 of the corrugated tube is provided on the inner surface 23. The pin insertion port 22 is opened at a position corresponding to the upper part of 11A, the rubber ring 3 is interposed between another recess 11B of the corrugated pipe and the inner surface 23 of the joint, and the pin insertion port 22 is penetrated to form a plastic ring. The joint structure for a corrugated pipe, wherein the detachment prevention pin 4 is fitted. 2. The joint structure for a corrugated pipe according to claim 1, wherein a peep hole 24 for confirmation is formed on substantially the same circumference as the position where the pin insertion opening 22 of the corrugated pipe 1 is opened. 3. The joint structure for a corrugated pipe according to claim 1 or 2, wherein a protrusion 43 for retaining is provided around a position where the detachment prevention pin 4 projects after penetrating into the pin insertion opening 22.