JPH0738468Y2 - Pipe joint for propulsion method - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pipe for a propulsion method for laying a pipeline in the ground without excavation.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing a conventional propulsion method. The propulsion method pipe 1a has already been pushed horizontally in the ground, and the step 12a provided at the back of the pipe receiving port 11a.
The protection ring 12a is fitted into. Further, the rubber ring 3a is fitted near the inlet side of the receiving port, and the subsequent propulsion method pipe 1b is horizontally pushed from the vertical shaft (not shown).
The tip 14b of 3b abuts the protection ring 2a, and the propulsive force is evenly pressed from the tip 14b of the trailing tube to the rear surface 21 of the protection ring 2a and transmitted from the front surface 22 to the socket step 12a of the leading tube. Move forward in the ground together. By thus interposing the protection ring on the abutting surfaces of both the front and rear pipes, it is possible to avoid the direct pressing of the pipe receiving port and the insertion port, and to prevent the mortar linings 15a and 15b on the pipe inner surface from cracking or peeling. I am trying.

[Problems to be solved by the device]

Conventionally, when the pipe line was laid by the propulsion method in a horizontal straight line, it did not pose a problem so far. However, in actual laying work, the pipeline is often curved, and at this time, unlike the case where the pipe is engaged by excavating it from the ground, it encounters a problem unique to the non-excavation method. 7 (a) and 7 (b) are explanatory views when the pipe is bent, and as shown in FIG. 7 (a), the propulsion method pipes 1a, 1b, 1c ,.
In order to draw an arc with a desired curvature R, it is necessary to make point contact at one end of the pipe so as to form a bending angle θ at each pipe joint. For this reason, as shown in Fig. (B), even if the protection ring 2a is installed in the joint portion of the front and rear pipes, the propulsive force actually sent from the rear is concentrated at the point O and cannot withstand this stress. It is not uncommon for an accident that the tip 14b of the insertion opening of the pipe is deformed or damaged and the pipe falls off. In order to solve the problems described above, the present invention provides
It is an object of the present invention to provide a pipe joint portion for laying a bent pipe path, which reduces the concentration of stress as much as possible according to its curvature.

[0004]

A joint portion of a pipe for a propulsion method according to the present invention has a protective ring fitted to a step at the inner part of the receiving end of the pipe, and has a large number of portions extending from the outer peripheral surface of the protective ring toward the center. The above-mentioned problems were solved by forming a through hole and fitting a pin into the through hole so as to be detachable.

[0005]

[Function] If the pipe line to be installed is straight, all the pins are fitted into all the through holes of the protection ring, or if all the pins are removed, the propulsive force transmitted from the rear is the entire rear surface of the protection ring. Receive evenly from the entire front surface to the mouth of the leading pipe evenly. If the pipe bends, if you remove the pin at the bending angle where the load concentrates and remove the pin where the stress concentrates, this part will be plastically deformed and the pressure receiving area that receives the stress will widen Reduce the load of and transmit to the preceding pipe. The part that is not stressed does not deform even if the pin is removed, but if necessary it is possible to fit the pin to maintain rigidity and adjust it with imbalanced strength as the entire circumference of the protection ring. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2A and 2B show an embodiment of the present invention. The front surface 22 comes into contact with the step surface by inserting the protection ring 2 into the step 12A provided at the deepest portion of the receiving port 11A of the preceding propulsion method tube 1A. Outer peripheral surface 2 of the protection ring 2
A large number of through holes 24 are drilled from 3 toward the center. The rubber ring 3 is fitted into the groove on the inlet side of the receiving end of the pipe, and the tip 14B of the insertion port 13B of the subsequent propulsion method pipe 1B to be inserted is fitted into the groove.
The front end 14B collides with the rear surface 21 of the protection ring 2 and further pushes the step 12A of the preceding propulsion method pipe 1A through the protection ring 2 and pushes forward to advance. FIG. 2A is a front view of the protection ring 2, and FIG. 2B is AA of FIG.
This is a cross section. FIG. 3 is a vertical cross-sectional view showing the action of the joint portion in which the bending angle θ is formed to draw a necessary arc when the pipe is bent, and the protection ring is provided near the origin O of the bending angle where stress concentrates. Is plastically deformed in such a manner as to compress the through hole 24, and contacts the rear surface 21 of the trailing propulsion method pipe insertion tip 14B and the preceding propulsion method pipe 1A.
The front surface 22 of the protection ring 2 that is in contact with the receiving step 12A is expanded and the area receiving a certain amount of stress is increased to reduce the propulsive force applied per unit area.

If the relationship between the size and number of the through holes 24 drilled in the protective ring 2, the width and elastic modulus of the protective ring 2, the compressive strength, and the total amount of propulsive force is investigated in advance, it is possible to obtain a planned bending conduit. It is possible to carry out the work after knowing in advance from which through hole 24 the pin should be pulled out in order to obtain the bending angle θ that exactly matches. FIG. 4 is a front view showing another embodiment of the present invention. Make a hole in the ring as a long hole and shift it diagonally to facilitate compression.

[0008]

[Effects of the Invention] The joint portion of the pipe for propulsion method according to the present invention is deformed or damaged at the tip of the pipe insertion port by buffering it by the plastic deformation of the protection ring 2 even if locally receiving a higher propulsion force. Since it is possible to prevent this, it is possible to apply the propulsion method for long-distance sections. In addition, by adjusting the presence or absence of a pin that fits into the protection ring, the bending angle can be set freely in both the horizontal and vertical directions, and this effect can be effectively used to correct the direction during construction. It can improve productivity.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

2A and 2B are a front view and a sectional view taken along line AA of the protection ring.

FIG. 3 is a vertical sectional view showing the operation of the above embodiment.

FIG. 4 is a front view showing another embodiment of the protection ring.

FIG. 5 is a vertical sectional view showing a conventional technique.

FIG. 6 is a side view showing a protection ring in the related art.

7 (a) and 7 (b) are a plan view and a vertical sectional view showing the problems of the conventional technique.

[Explanation of symbols]

 1 Tube for propulsion method 2 Protective ring 11 Receptacle 12 Recessed step 13 Insertion opening 14 Tip of insertion opening 23 Outer peripheral surface of protection ring 24 Through hole

Claims (1)

[Scope of utility model registration request] 1. A joint portion of a propulsion method pipe that is advanced by receiving a propulsive force transmitted from a tip of a pipe insertion port of a succeeding pipe by fitting a protection ring on a step inside the receiving port of the propulsion method pipe. A joint part for a propulsion method pipe, characterized in that a large number of through holes are bored from the outer peripheral surface of the ring toward the center, and pins are detachably fitted into the through holes.