JPH0431784Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention is used as an excavation pipe when penetrating a hole underground, and after the excavation is completed, a power cable or a communication cable is inserted into the pipe. This relates to a cable burying pipe that also serves as a cutting pipe.

[Conventional technology]

From one manhole to the next,
While pushing the pipe into the ground, the earth and sand excavated near the tip of the pipe are discharged through the pipe towards the front side, and when the entire length of the pipe has been pushed in, the next pipe is connected and pushed in further.

After the tip of the pipe reaches the next manhole, the inside of the pipe is cleaned and the cable is passed through.

When adding the above-mentioned pipes, it is easy to connect them by screwing, but when an obstacle occurs during excavation and the pipe is turned and retreated, there is a risk that the screws at the joint may loosen and come off.

Therefore, generally the pipes are joined by welding one after another while pushing them into the ground.

[The problem that the idea aims to solve]

However, welding the pipes together requires a welder, a power source, and a welding technician, and furthermore, the welding work is performed inside a manhole, which poses problems in terms of workability and safety.

The object of the present invention is to provide a cable burying pipe that can be used as a cutting pipe and can be easily and quickly connected without requiring a welding machine or other mechanical equipment.

[Means to solve the problem]

In order to achieve the above object, the present invention forms a thread at one end of a rigid tube of unit length, a female thread at the other end, and a circumferential direction on the part behind the male thread end of the male thread forming surface. In addition, a slotted groove slightly longer than half the circumference is provided on the part of the internal thread forming surface in front of the starting end of the internal thread, and the slotted groove is fitted across the matching slotted groove and the circumferential groove by mutual threaded connection of the pipes. The main feature is that it is equipped with an arcuate stop ring.

[Effect]

When approximately the entire length of the preceding pipe has been pushed into the ground, the next pipe is screwed into the rear end of that pipe, and when the slotted groove of one pipe matches the circumferential groove of the other pipe, Fit an arcuate stop ring into the slotted groove and the circumferential groove from the side.

The ring then fits across the slotted groove and the circumferential groove.

〔Example〕

The structure of the cable embedding pipe of the present invention will be explained with reference to the drawings. Figure 1 is a side view, Figure 2 is a vertical side view, and the unit length (generally 2.75m or 5.5m)
Rigid pipe 1 (outer circumference approximately 165 mm), for example, a steel pipe
mm/thickness approximately 7 mm), one has a male thread 2 and the other has a female thread 3 at both ends (approximately 80 mm each).

It goes without saying that the male thread 2 and the female thread 3 have the same reference angle shape (square thread in the figure) and reference dimensions. Further, the male thread 2 and female thread 3 are formed within the range of the wall thickness of the tube 1. That is, the male thread 2 does not protrude outward from the outer diameter of the tube 1, and the female thread 3 does not protrude inward from the inner diameter of the tube 1.

A circumferential groove 4 having a concave cross section is provided in a portion of the male thread forming surface 21 behind the male thread terminal end.

On the other hand, in a portion of the female thread forming surface 31 in front of the starting end of the female thread, a slotted groove 5 extending about two-thirds of the circumference is provided.

And an arc-shaped stop spring 6 made of steel, for example, having a width and length that fits in the slot groove 5.
is available. The thickness of the ring 6 (height in cross section) is greater than the wall thickness of the tube 1.

Figure 3 is a perspective view illustrating the procedure for connecting pipes, where the male thread 2 of the next pipe 1A is attached to the rear end of the pipe 1 (male thread 2 facing first) that was previously pushed into the ground. Screw it.

When the tube 1A is connected by screwing, since the mating tube 1 is fixed, a large load is applied to the screwing side, that is, the screw 2. Therefore, in terms of the strength of the pipe, it is preferable that the minimum wall thickness of the male thread forming portion be greater than the minimum wall thickness of the female thread forming portion.

When the circumferential groove 4 of the next tube 1A matches the slotted groove 5 of the previous tube 1, the stop ring 6 is fitted into the slotted groove 5 and further pushed in until it engages with the circumferential groove 4.

Then, the stop ring 6 engages in a state spanning the slot groove 5 and the circumferential groove 4, as shown in FIG. 4, and serves to prevent the screws 2 and 3 from returning. The stop ring 6 has some springiness due to its shape.

As in the embodiment, the male thread 2 and the female thread 3 are
If it is formed within the wall thickness of the pipe 1, there will be no protruding parts inside and outside the connecting part of the pipe, so that the pipe can be pushed into the ground and the earth and sand inside the pipe can be smoothly discharged.

Also, it does not interfere with cable insertion.

[Effect of idea]

Since the cable embedding pipe of the present invention has the above-mentioned configuration, compared to conventional welding for connection and fixation, it does not require the use of mechanical equipment for connection, and can be done quickly by simply screwing and fitting the stop ring. Tubes can be connected together.

Furthermore, the screw connection does not loosen due to the engagement action of the stop ring, so if an obstacle occurs during excavation and the pipe is turned and retreated, there is no risk of the pipe connection coming off, making it highly workable. There is.

[Brief explanation of the drawing]

Fig. 1 is a side view of the invented cable burying pipe, Fig. 2 is a longitudinal side view thereof, Fig. 3 is a perspective view illustrating the procedure for connecting the pipe, and Fig. 4 is an enlarged longitudinal section of a portion of the pipe connection part. Side view. 1 and 1a are rigid tubes, 2 is male thread, 3 is female thread,
4 is a circumferential groove, 5 is a slotted groove, and 6 is a stop ring.

Claims (1)

[Scope of utility model registration request] A thread is formed on one end of a rigid tube of unit length, and a female thread is formed on the other end, and a circumferential groove is formed on the male thread forming surface behind the male thread end, and a circumferential groove is formed on the male thread forming surface at the female thread starting end. A pipe for burying cables with a slotted groove slightly longer than half the circumference in the front part, and an arcuate stop ring that fits across the slotted groove and the circumferential groove, which are matched by threaded connections between the pipes. .