JPH0755429Y2 - Corrugated pipe and pipe joint structure - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a corrugated pipe and a pipe joint structure, and more specifically, it is made of a synthetic resin capable of rubber ring joining without using a pipe joint for connecting the corrugated pipe. The present invention relates to a corrugated pipe and a pipe joint structure.

[Prior Art] A corrugated tube is a tube having high flat strength and excellent flexibility in a bending direction. As a technique for connecting the corrugated pipes, as shown in FIG. 5, the corrugated pipes 22 and 22 are inserted from both directions into a pipe joint 21 having a stopper 21a at the center of the inner surface of the cylindrical body and an adhesive is used. The method of fixing is common. However, this method does not allow corrugated pipes at the construction site.
In addition to 22, it is necessary to prepare the pipe joint 21. Therefore, from the perspective of simplifying parts management and improving efficiency in field work,
There is a need for corrugated pipes that do not require pipe fittings.

Furthermore, in the case of the connection structure shown in FIG. 5, the wall thickness of the pipe joint is increased in order to prevent the adhesive surface from coming off when the joint portion bends, so that the rigidity is increased and the flexibility of the corrugated pipe is improved. Need to be suppressed.

[Problems to be Solved by the Invention] The present invention has been made in view of the above circumstances, and provides a corrugated pipe and a pipe joint structure which can be connected without a pipe joint and which are excellent in flexibility of a joint portion. It is intended.

[Means for Solving the Problems] A corrugated tube according to the present invention, which has achieved the above object, has a plurality of peaks and troughs continuously formed in a corrugated shape in the axial direction, and
A rubber ring-bonded hard vinyl chloride corrugated pipe with a nominal diameter of 75 has a smooth diameter expansion receiving portion with a wall thickness of 3.5 mm or less formed on at least one end of the corrugated pipe. And

Further, the pipe joint structure of the present invention has a corrugated pipe made of hard vinyl chloride with rubber ring joints in which a plurality of peaks and troughs are continuously formed in a corrugated form in the axial direction and the nominal diameter is 75. In the pipe joint structure of, the diameter expansion port or the insertion port has a wall thickness of 3.5 mm
The gist is that it consists of the following smooth portions.

[Operation and Embodiment] FIG. 1 is a schematic partial cross-sectional view showing an embodiment of the corrugated tube according to the present invention, in which one side or both sides of the corrugated tube 1 is formed with a smooth diameter expanding port 2. The smooth diameter-increasing receiving portion 2 has a diameter increased by leaving a part of the pipe end as a smooth portion without corrugating the diameter when manufacturing a corrugated pipe. On the other hand, the insertion part 3 joined to the smooth diameter expansion receiving part 2 is
Any ordinary corrugated pipe end shape may be used, and a ring-shaped packing 4 is attached to the tip of the corrugated pipe so that the corrugated pipe can be connected to the smooth diameter-enlarging port 2 while maintaining hermeticity. As a typical example of the corrugated pipe according to the present invention,
A corrugated tube with a nominal diameter of 75φ and a smooth diameter expansion port with a thickness of 2.5 mm can be used.

Further, the corrugated tube of the present invention includes a case of single-sided piece insertion and a case of double-sided reception. Therefore, at the time of pipe construction, the corrugated pipes with single-sided and single-sided insertion may be sequentially connected, or the corrugated pipes with both receiving ends may be alternately combined and connected with a normal double-ended insertion-type corrugated pipe.

FIG. 2 is a schematic explanatory view showing another pipe joint structure developed to achieve the same purpose as the corrugated pipe of FIG. The insertion side 5 is formed to have the same diameter as the valley portion 6 of the corrugated pipe and is formed smoothly, and the reception side 7 is expanded by the pipe thickness of the insertion side 5 and the packing 4 is arranged on the inner peripheral surface of the tip. It has a structure to be installed. Therefore, when manufacturing a corrugated pipe having the above pipe joint structure, a single-sided piece inserted corrugated pipe and a double-sided inserted corrugated pipe are conceivable, but piping is performed using a single-sided piece inserted corrugated pipe from the viewpoint of easy parts management. Is desirable.

The wall thickness of the corrugated pipe and pipe fitting structure of the present invention was limited by the results of bending airtightness test using the following hard PVC corrugated pipe. The test is carried out by the apparatus shown in FIG. 3, and the corrugated tube 11 on the insertion side and the smooth tube 12 on the receiving side are joined together via the packing 4, and both ends of the steel plate 1
Adhere it to 3,14, and further cut the bolts on both sides of the iron plate 13,14 1
A bending angle θ of 1 to 5 ° was obtained by connecting 5 and 16 and adjusting the length of the slicing bolt between the iron plates. A in this state
Compressed air is fed from the direction and an internal pressure of 0.5 kg / cm ² is applied to
After holding for a minute, the state of pressure drop due to air leakage was examined.

The inner diameter of the inlet-side smooth tube 12 used in the above test was 107 mm, and the thickness was 2.5, 3.3, 3.7, and 6.5 mm. As the packing, four kinds of rubber rings (R1 to R4) whose schematic sectional shape is shown in FIG. 4 were used. Outer diameter OD of each rubber ring,
Table 1 shows the inner diameter ID, hardness, and insertion force of the socket.

The results of the bending airtightness test conducted in this manner are shown in Table 2 by x when the air leaked and the pressure dropped, and ◯ when there was no air leak.

As can be seen from Table 2, the thinner the smooth portion to be joined, the better the bending airtightness. This is because when the tube thickness of the smooth part becomes thicker and the rigidity improves, the flexibility in the bending direction decreases,
It is considered that this is because the followability of the rubber ring to the bending of the joint is poor. The above test shows that the wall thickness should be 3.5 mm or less. When the same experiment was performed by changing the wall thickness of the corrugated portion, the same result was obtained in any case. This is also supported because the flexibility of the corrugated pipe in the bending direction depends exclusively on the corrugated structure and not on the wall thickness. Further, the corrugated pipe and the pipe joint structure of the present invention can be applied to any synthetic resin pipe, and a hard PVC pipe is particularly preferable in terms of flexibility and strength.

[Advantages of the Invention] Since the present invention is configured as described above, it is possible to provide a corrugated pipe and a pipe joint structure which can be connected without a pipe joint and which is excellent in flexibility of a joint portion.

[Brief description of drawings]

1 and 2 are schematic explanatory views showing a joint portion of the corrugated pipe of the present invention, FIG. 3 is a schematic explanatory diagram showing an apparatus used for a bending airtight test, and FIG. 4 is a rubber interposed in the pipe joint portion. FIG. 5 is a cross-sectional view showing a typical example of a ring, and FIG. 5 is a schematic explanatory view showing a conventional corrugated pipe joining method. 1 ... Corrugated tube, 2 ... Expanding smooth receiving part 3 ... Inserting part, 4 ... Packing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Matsumiya 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (56) References 55-54153 (JP, Y2)

Claims (2)

[Scope of utility model registration request] 1. A hard vinyl chloride corrugated pipe made of a rubber ring joint, wherein a plurality of peaks and troughs are continuously formed in a corrugated form in the axial direction, and a nominal diameter is 75. Thickness on at least one of the ends
A corrugated tube characterized by being formed with a smooth diameter expansion opening of 3.5 mm or less. 2. A pipe joint structure for a corrugated pipe made of hard vinyl chloride and made of a rubber ring, wherein a plurality of peaks and troughs are continuously formed in a corrugated form in the axial direction and a nominal diameter is 75. A pipe joint structure characterized in that the expanded diameter receiving port or the inserting port is made of a smooth portion having a wall thickness of 3.5 mm or less.