JPS622396Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a method for propelling a double steel pipe consisting of an inner steel pipe, an outer steel pipe, and mortar or concrete interposed between them over long distances underground. This relates to an intermediate push propulsion joint that is used in cases where

[Prior art]

Conventionally, as one of the construction methods for propelling and laying steel pipes underground, an intermediate push jack is interposed between the leading double steel pipe and the trailing double steel pipe, and a propulsion jack is installed at the rear end of the trailing double steel pipe. A sealing material is installed between the rear end of the trailing double steel pipe and the front end of the trailing double steel pipe, and the propulsion jack is used to tighten the trailing double steel pipe with the intermediate push jack shortened. An intermediate pressing method is being implemented in which the process of propelling the pipe and the process of propelling the trailing double steel pipe using an intermediate pushing jack are alternately repeated.

[Problem that the invention attempts to solve]

When the above-mentioned intermediate pressing method is implemented, the sealing material is likely to be damaged by dirt entering the sealing part, resulting in poor seal reliability and the leading double steel pipe and trailing double steel pipe becoming eccentric or bent. etc.

[Purpose of the invention, structure]

The purpose of this invention is to provide an intermediate push joint for double steel pipes that advantageously solves the above-mentioned problems, and the gist of this invention is to:
The front part of the inner steel pipe 4 in the trailing double steel pipe 3 is inserted into the rear part of the outer steel pipe 2 in the leading double steel pipe 1, and the front outer circumference of the inner steel pipe 4 has a cylindrical shape having a bellows-like extensible part 5. A sealing material 6 is fitted, and the front end of the cylindrical sealing material 6 is fixed to the rear end of the outer steel pipe 2, and the rear end of the cylindrical sealing material 6 is fixed to the outer periphery of the inner steel pipe 4. The sheath pipe 8 fitted over the outside of the rear end of the outer steel pipe 2 and the front part of the outer steel pipe 7 in the trailing double steel pipe 3 is connected to the outer steel pipe 2 of the leading double steel pipe. , a seal ring 12 provided on the outer periphery of the front end of the inner steel pipe 4 in the trailing double steel pipe 3 is pressed against the rear inner circumferential surface of the outer steel pipe 2 in the leading double steel pipe 1, and the inner periphery of the rear end of the sheath pipe 8 is pressed. A seal ring 14 made of an elastic body fixed to the surface of the trailing double steel pipe 3
This is a double steel pipe intermediate thrust propulsion joint characterized by being slidably fitted onto the front outer circumferential surface of the outer steel pipe 7.

〔Example〕

Next, this invention will be explained in detail using illustrated examples.

The drawing shows an embodiment of this invention, in which the outer steel pipe 2 of the leading double steel pipe 1 is extended rearward than the inner steel pipe 9, and the trailing double steel pipe 3 is extended rearward than the inner steel pipe 9.
The inner steel pipe 4 extends further forward than the outer steel pipe 7, and the outer circumference of the exposed front end of the inner steel pipe 4 in the trailing double steel pipe 3 is provided with a bellows-shaped telescopic portion 5.
A cylindrical sealing material 6 made of rubber, metal, etc. is fitted, and the cylindrical sealing material 6 consists of a front cylinder 10 and a rear cylinder 11 that are integrally connected to the front end and the rear end of the cylinder. The rear cylindrical body 11 is watertightly fixed to the inner steel pipe 4 by adhesive, welding, etc., and the outer periphery of the exposed front end of the inner steel pipe 4 has rubber, A front seal ring 12 made of plastic or the like is fitted and preferably fixed with adhesive or the like.

The front end of the inner steel pipe 4 in the trailing double steel pipe 3 is inserted into the rear end of the outer steel pipe 2 in the leading double steel pipe 1, and the outer peripheral surface of the front seal ring 12 is inserted into the rear end of the outer steel pipe 2. A ring 13 made of metal, plastic, rubber, etc. is fitted into the rear end of the outer steel pipe 2 and is pressed against the inner peripheral surface, and is fixed by welding, adhesive, etc. The cylindrical body 10 is fitted onto the outer periphery of the rear end of the outer steel pipe 2 and is fixed watertightly by adhesive, welding, or the like. Further, the steel sheath pipe 8 has a rear seal ring 14 made of an elastic material such as rubber or soft plastic fixed to the inner peripheral surface of the rear end for preventing dirt and sand intrusion by adhesive, bolts, etc.
The sheath pipe 8 is fitted over the rear end outer circumferential surface of the outer steel pipe 2 and the front outer circumferential surface of the outer steel pipe 7 in the trailing double steel pipe 3, and the front end of the sheath pipe 8 is fitted over the outer steel pipe 2 with a steel plate ring. 22 by welding, and the inner peripheral surface of the rear seal ring 14 is pressed against the front outer peripheral surface of the outer steel pipe 7 in the trailing double steel pipe 3.

A steel pressure wheel 16 having a reinforcing rib 15 is abutted against the rear end of the inner steel pipe 9 of the leading double steel pipe 1, and a steel support wheel 1 having a reinforcing rib 15 is abutted against the front end of the inner steel pipe 4 of the trailing double steel pipe 3.
7 is abutted against the pressure wheel 16, and a number of hydraulic inner jacks 19 are arranged at intervals around the pressure wheel between the pressure wheel 16 and the support wheel 17, and the jack holder 18 into which the inner jacks 19 are fitted is fixed to the outer steel pipe 2 by tack welding or other means, with the end of the cylinder 20 in the inner jack 19 abutting against the pressure wheel 16 and the jack head 21 in the inner jack 19 abutting against the support wheel 17.

When performing intermediate push propulsion, as shown in FIG. 1, then advance the trailing double steel pipe 3 and shorten the intermediate push jack 19,
By repeating the above-described operations, the leading double steel pipe 1 and the trailing double steel pipe 3 are alternately and repeatedly propelled.

When the leading double steel pipe 1 is advanced, the cylindrical sealing material 6
is extended, and when the trailing double steel pipe 3 is advanced, the cylindrical sealing material 6 is shortened, and when one of the double steel pipes is advanced, the front seal ring 12 covers the inner peripheral surface of the outer steel pipe 2. At the same time as sliding, the rear seal ring 14 also slides on the outer peripheral surface of the outer steel pipe 7.

In addition, in the figure, 23 is mortar or concrete in the double steel pipes 1 and 3.

[Effect of idea]

According to this invention, a cylindrical sealing material 6 having a serpentine elastic portion 5 is fitted on the outer periphery of the front part of the inner steel pipe 4 in the trailing double steel pipe 3, and the front end of this cylindrical sealing material 6 is fitted. Outer steel pipe 2 in the preceding double steel pipe 1
Since the rear end portion of the cylindrical sealing material 6 is watertightly fixed to the outer circumference of the inner steel pipe 4 in the trailing double steel pipe 3, the outer circumference of the inner steel pipe 4 in the trailing double steel pipe 3 is Compared to the case of sealing only with a sliding seal material between the steel pipe 2 and the inner steel pipe 4 in the trailing double steel pipe, it is possible to provide complete sealing performance, and the sheath pipe 8 provides a cylindrical seal. In addition, the seal ring 12 provided on the outer periphery of the front end of the inner steel pipe 4 in the trailing double steel pipe 3 is attached to the rear inner peripheral surface of the outer steel pipe 2 in the leading double steel pipe 1. Since it is pressure-welded, even if the cylindrical sealing material 6 is damaged for some reason, the seal ring 12 can stop the water, and the seal ring 12 can also stop the water. In this way, the outer steel pipe 2 and the inner steel pipe 4 can be kept almost concentrically, and furthermore, the seal ring 14 made of an elastic body fixed to the inner peripheral surface of the rear end of the sheath pipe 8 is attached to the trailing double steel pipe 3. Since it is slidably fitted to the front outer peripheral surface of the outer steel pipe 7, it is possible to prevent dirt and water from entering between the rear end of the sheath pipe 8 and the outer steel pipe 7. , the seal ring 12 and the sheath tube 8
In cooperation with the seal ring 14, the leading double steel pipe 1 and the trailing double steel pipe 3 can be held so as not to bend. Further, when the leading double steel pipe 1 and the trailing double steel pipe 3 are propelled alternately, the bellows-shaped extensible portion 5 of the cylindrical sealing material 6 is simply expanded and contracted, and the cylindrical sealing material 6 is Since the cylindrical sealing material 6 is not repeatedly slid while being strongly pressed against the outer steel pipe 2 and the inner steel pipe 4, there is no risk of the cylindrical sealing material 6 being damaged by sliding during the intermediate pushing operation, and therefore the sealing performance is improved during the intermediate pushing operation. Effects such as being able to eliminate the possibility of a decrease in the temperature can be obtained.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention, in which Figure 1 is a partially cutaway longitudinal side view showing the state before the leading double steel pipe is propelled, and Figure 2 is the state after the leading double steel pipe is propelled. FIG. In the figure, 1 is a leading double steel pipe, 2 is an outer steel pipe of the leading double steel pipe, 3 is a trailing double steel pipe, 4 is an inner steel pipe of the trailing double steel pipe, 5 is a telescopic portion, 6 is a cylindrical sealing material, 7 is the outer steel pipe of the trailing double steel pipe, 8 is the sheath pipe, 9
is the inner steel pipe of the preceding double steel pipe, 10 is the front cylinder body, 1
1 is a rear cylinder body, 12 is a front seal ring, 14 is a rear seal ring, 16 is a steel press ring, 17 is a steel support ring, 18 is a jack holder, and 19 is an intermediate push jack.

Claims (1)

[Scope of utility model registration request] The front part of the inner steel pipe 4 in the trailing double steel pipe 3 is inserted into the rear part of the outer steel pipe 2 in the leading double steel pipe 1, and the front outer circumference of the inner steel pipe 4 has a cylindrical shape having a bellows-like extensible part 5. A sealing material 6 is fitted, and the front end of the cylindrical sealing material 6 is fixed to the rear end of the outer steel pipe 2, and the rear end of the cylindrical sealing material 6 is fixed to the outer periphery of the inner steel pipe 4. The sheath pipe 8 fitted over the outside of the rear end of the outer steel pipe 2 and the front part of the outer steel pipe 7 in the trailing double steel pipe 3 is connected to the outer steel pipe 2 of the leading double steel pipe. , a seal ring 12 provided on the outer periphery of the front end of the inner steel pipe 4 in the trailing double steel pipe 3 is pressed against the rear inner circumferential surface of the outer steel pipe 2 in the leading double steel pipe 1, and the inner periphery of the rear end of the sheath pipe 8 is pressed. A seal ring 14 made of an elastic body fixed to the surface of the trailing double steel pipe 3
A medium-pressing propulsion joint for a double steel pipe, characterized in that it is slidably fitted onto the front outer circumferential surface of an outer steel pipe 7.