JP2002309887A - Excavation pipe-jacking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excavation pipe-jacking device, in which the installing distance of a pipe material can be lengthened and which has excellent practicability, by disposing a cutoff packing at a place where the pipe material can be exchanged. SOLUTION: In the excavation pipe-jacking device in which an excavating section 4 is installed at a front end, the (n) pipe materials 1 are disposed at the rear of the excavating section 4, the two adjacent pipe materials are mounted under a fitted state and a ground is excavated by the excavating section 4 while adjacent other pipe materials 1 are slid and pipe-jacked to one pipe materials 1, mounting sections 5 are secured at the end sections of the internal pipe materials 1 and the cutoff packings 2 closing openings among the outer circumferential surfaces of the internal pipe materials 1 and the inner circumferential surfaces of the pipe materials 1 on the outside in the two adjacent pipe materials are set up to the mounting sections 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling propulsion device used for a propulsion method for arranging a sewer pipe or the like.

[0002]

2. Description of the Related Art A shaft is drilled, and a drilling device provided with a drilling portion at the tip from the peripheral wall of the shaft is pushed by an appropriate means such as a propulsion jack.
There is a so-called middle-push construction method as a so-called middle-push construction method for arranging a sewer pipe or the like in the ground by sequentially pushing additional pipe members behind the excavation propulsion device.

FIG. 1 shows the structure of the intermediate pushing method. A shaft 21 is bored, and an excavator 23 provided with an excavation portion 4 at the end from the peripheral wall of the shaft 21 is pushed by a propulsion jack 24. This is a configuration in which the pipe 1 is sequentially pushed further behind the excavator 23 (note that the pipe 1 is a concept including a plurality of pipes 1 connected in a row. The same reference numerals are used.)

[0004] More specifically, the illustrated one is divided into a tube member 25 at the front end, an intermediate tube member 26, and a tube member 27 at the rear end. Further, a first pressing jack 28 and a second pressing jack 29 are provided between the front pipe member 25 and the middle pipe member 26 and between the middle tube member 26 and the rear end pipe member 27, respectively. In the figure, reference numeral 30 denotes a sliding material outlet 30 for leading a sliding material for reducing frictional resistance between the pipe material and the ground.

In the above-described intermediate pressing method, first, the first pressing jack 28 is extended rearward so that the distal end pipe 25 is pushed forward with respect to the intermediate pipe 26, and then the first pressing jack 28 is once extended. Is stopped, and then the first pressing jack 28 is contracted and the second pressing jack 29 is extended rearward, so that the intermediate pipe 26 is propelled forward with respect to the rear end pipe 27 (in this state, Since the first pressing jack 28 contracts, the distal end pipe member 25 is not propelled.) Then, once the extension of the second pressing jack 29 is stopped, the second pressing jack 29 is contracted and the propulsion jack 24 is moved. By extending forward, the rear end pipe 27 is propelled forward (in this state, since the second pressing jack 29 contracts, the middle pipe 26
Does not promote. ), And by repeating the above, each pipe material is propelled forward.

Therefore, according to this intermediate pressing method, the frictional resistance between the pipe material and the ground generated when the pipe material is propelled becomes the surface integral of the front pipe material, the middle pipe material, or the rear pipe material. The frictional resistance between the pipe material and the ground is small, so that the pipe material can be disposed over a long distance, and effects such as the use of a low-output propulsion jack can be obtained.

[0007] By the way, in the middle-pressing method, due to its configuration, it is generated at the ground from between the pipes, that is, between the pipe at the front end and the pipe at the middle, and between the pipe at the middle and the pipe at the rear end. Spring water is easy to invade. Therefore, in order to prevent the intrusion of the spring water, for example, as shown in FIG. 2, a ring is provided between the extension portion 31 extending behind the distal end pipe 25 and the distal end portion of the intermediate pipe 26. A permanent watertight packing 8 is provided in a fixed state, and the permanent watertight packing 8 closes a gap between the inner peripheral surface of the pipe member 25 at the tip and the outer peripheral surface of the intermediate pipe member 26.

However, as described above, the middle pressing method is a method in which the pipe member 25 at the tip and the intermediate pipe member 26 slide relatively to each other, and thus has a disadvantage that the permanent watertight packing 8 is extremely liable to wear. .

Therefore, if the worn permanent watertight packing 8 can be replaced, the pipe material can be disposed over a long distance. However, in the middle press method according to the Japanese Sewerage Standard (JSWAS), the permanent watertight packing 8 is not adjacent to the pipe. Of the two pipes to be formed, a configuration in which the gap between the inner pipe and the inner circumference of the outer pipe is closed by being fitted to the outer peripheral surface of the inner pipe, that is,
The permanent waterproof packing is configured to be sandwiched between the inner pipe material and the outer tubular material, and the replacement of the permanent waterproof packing 8 is practically impossible.

[0010] Therefore, although the intermediate press method should be able to dispose the pipe material over a long distance, the disposition distance of the pipe material 1 is currently limited due to the problem of the service life of the permanent watertight packing 8.

The present invention solves the above problems,
It is an object of the present invention to provide a highly practical excavation propulsion device in which the watertight packing is provided at a position where the pipe material can be replaced, so that the installation distance of the pipe material can be lengthened.

[0012]

The gist of the present invention will be described with reference to the accompanying drawings.

The excavation section 4 is provided at the tip, and n pipes 1 are disposed behind the excavation section 4. Two adjacent pipes are provided in a fitted state. An excavation propulsion device for excavating and slidingly propelling another tube 1 adjacent to one tube 1, wherein an attachment 5 is provided at an end of the inner tube 1, and the attachment 5 is provided with The present invention relates to an excavation propulsion device having a watertight packing 2 for closing a gap between an outer peripheral surface of an inner tube 1 and an inner peripheral surface of an outer tube 1 in two adjacent tubes. .

The excavation part 4 is provided at the tip, and the first pipe material, the second pipe material,.
A second pipe is provided, and two adjacent pipes are provided in a fitted state.
The -2nd pipe is slid and propelled with respect to the (n-1) th pipe, and then the propulsion of the (n-2) th pipe is stopped and the (n-1) th pipe is slid and propelled with respect to the nth pipe. In the excavation propulsion device, a mounting portion 5 is provided at an end portion of the inner tube 1, and the outer peripheral surface of the inner tube 1 and the outer tube 1 of the two adjacent tubes are provided on the mounting portion 5. Seal 2 that closes the gap with the inner peripheral surface
The present invention relates to an excavation propulsion device characterized in that a drilling propulsion device is provided.

Further, in the excavation propulsion device according to the second aspect, the (n-1) -th pipe is pressed against the (n-2) -th pipe, and the (n-2) -th pipe is replaced with the (n-1) -th pipe by a reaction force of the pressing. The present invention relates to an excavation propulsion device characterized in that a pressing jack 10 for propelling a pipe material forward is provided.

The excavation propulsion device according to any one of claims 1 to 3, wherein the mounting portion 5 is attached to an end surface of the inner tube 1. is there.

The excavation propulsion device according to any one of claims 1 to 4, wherein at least one of the mounting portion 5 and the watertight packing 2 is detachably provided. It is related.

Further, in the excavation propulsion device according to any one of claims 1 to 5, a gap between the outer peripheral surface of the inner tube 1 and the inner peripheral surface of the outer tube 1 at any time as the water stop packing 2. The present invention relates to an excavation propulsion device characterized in that a water-stop packing 2 for closing off is used.

Further, in the excavation propulsion device according to any one of claims 1 to 6, the watertight packing 2 has a hollow portion 6 therein and swells by injecting a fluid into the hollow portion 6. The present invention relates to an excavation propulsion device characterized in that a waterproof watertight packing 2 is employed.

Further, in the excavation propulsion device according to any one of claims 1 to 7, the outer pipe material 1 may be used as the mounting portion 5.
The present invention relates to an excavation propulsion device, wherein a concave strip-shaped mounting portion 5 having an opening 9 opening to the side is employed.

Further, in the excavation propulsion apparatus according to any one of claims 1 to 8, a vertically movable pusher 7 is provided at the bottom of the mounting portion 5, and the mounting portion is moved by the push of the pusher 7. 5. The excavation propulsion device according to claim 1, wherein the watertight packing 2 housed in the outer tube 5 is configured to abut on the inner peripheral surface of the outer tubular member 1.

Further, in the excavation propulsion device according to any one of claims 1 to 9, the inner pipe 1 is always in contact with the inner peripheral surface of the outer pipe 1 on the outer peripheral surface to close the gap therebetween. The present invention relates to an excavation propulsion device characterized in that a pipe material 1 provided with a permanent watertight packing 8 is employed.

[0023]

Since the waterproof packing 2 is provided on the mounting portion 5 provided at the end of the inner tube 1,
Even between the mounting portion 5 and the outer tube 1,
Can be easily moved to the side, and thus the worn watertight packing 2 can be replaced by attaching / detaching the watertight packing 2 or attaching / detaching the mounting portion 5 from the inside of the tube material 1. Can be.

Further, even if the inner pipe 1 is, for example, a middle-pushed pipe defined by the existing Japan Sewerage Standard (JSWAS), the mounting section 5 is provided at the end of the inner pipe 1 so that the inner pipe 1 can be easily manufactured. The present invention can be remodeled.

Since the present invention is constructed as described above, the watertight packing can be replaced, and the excavation propulsion device with excellent practicality can inevitably lengthen the arrangement distance of the pipe material.

[0026]

3 and 4 show a first embodiment, FIG. 5 shows a second embodiment, FIG. 6 shows a third embodiment, FIG. 7 shows a fourth embodiment, and FIG.
Illustrates a fifth embodiment, which will be described below.

In the first embodiment, a shaft 21 is bored,
The excavator 23 provided with the excavation part 4 at the tip from the peripheral wall of 21 is pushed by the propulsion jack 24, and the pipe material is sequentially pushed further behind the excavator 23. In the case of the drawing, this pipe material 1 Leading tube 25, middle tube 26 and trailing tube 27
(In this case, the pipe 1 is formed by connecting a plurality of pipes in a row.) Between the front pipe 25 and the middle pipe 26, and between the middle pipe 26 and the rear pipe 27. The first pushing jack 28 and the second pushing jack 29 are provided between them, respectively. This is an excavation propulsion device used in a so-called middle pushing method (FIG. 1).
reference).

In the drawing, a small-diameter portion 32 is provided at the front end of the middle tube 26 and the front end of the rear tube 27, respectively, and the rear end of the front tube 25 and the rear end of the middle tube 26 are provided. At the end, there is provided a fitting portion 31 fitted to the small diameter portion 32, and the gap between the outer peripheral surface of the small diameter portion 32 and the inner peripheral surface of the fitting portion 31 is always closed. Each of the permanent watertight packings 8 for preventing water leakage is provided, and a mounting portion 5 is provided at a distal end of the small-diameter portion 32. The mounting portion 5 is covered with the outer peripheral surface of the small-diameter portion 32. Fitting part
The structure in which the water-stop packing 2 for closing the gap with the inner peripheral surface of 31 is provided is illustrated. In addition, the structure of these pipe materials 1 is the structure of the center push pipe prescribed | regulated to the existing Japanese sewer standard (JSWAS).

The mounting portion 5 is attached to the distal end surface of the small diameter portion 32 of the inner tube 1.

The mounting portion 5 includes an annular bottom member 11 attached to the distal end of the small diameter portion 32 and an annular pressing member 12 attached to the bottom member 11. Of the bottom member 11, and the inner surface of the holding member 12 are set in the storage portion 13 for storing the watertight packing 2.

The bottom member 11 and the pressing member 12 are formed by arranging a plurality of divided bottom members 16 and divided pressing members 17 in a tubular shape.
A configuration of 11 and the holding member 12 is adopted.

The holding member 12 is provided detachably on the bottom member 11. Therefore, the waterproof packing 2 housed in the housing part 13 can be reduced in diameter by removing the pressing member 12.
It can be taken out of the storage section 13 by moving it toward the distal end side of 32. Reference numeral 14 indicates that the holding member 12 is a bottom member.
A mounting screw body 14 for detachably mounting the mounting screw body 11. The mounting screw bodies 14 are juxtaposed at predetermined intervals in the circumferential direction.

For example, the holding member 12 and the bottom member 11 may be integrated, and the holding member 12 and the bottom member 11 may be detachably provided on the small diameter portion 32. In this case, the holding member 12
By removing the bottom member 11 and the watertight packing 2, the small-diameter portion 32 is removed.
It can be removed from the tip of the.

The waterproof packing 2 is provided at any time with a gap between the outer peripheral surface of the small-diameter portion 32 (the outer peripheral surface of the inner tube 1) and the inner peripheral surface of the fitted portion 31 (the inner peripheral surface of the outer tube 1). A watertight packing 2 for closing off is adopted.

Specifically, at the bottom of the storage portion 13, a pusher 7 for pressing the watertight packing 2 stored in the storage portion 13 toward the fitted portion 31 is provided so as to be vertically movable. Therefore,
When the pressing body 7 moves up and down, the waterproof packing 2 closes the gap between the outer peripheral surface of the small diameter portion 32 and the inner peripheral surface of the fitted portion 31 at any time. In the figure, reference numeral 15 denotes a push screw body 15 that moves the pusher 7 up and down.

The pusher 7 also has a configuration in which a plurality of divided pushers 18 are arranged in a tubular shape.

Further, in the first embodiment, an elastic body 19, specifically, a hollow tube made of rubber is disposed between the watertight packing 2 and the pushing body 7, and the watertight packing is also provided by this hollow tube. The structure which presses 2 to the fitting part 31 side is employ | adopted. With this configuration, for example, even if the pushing movement of some of the divided pushing bodies 18 is improper, if the pushing movement of the remaining divided pushing bodies 18 is appropriate, the appropriate pushing movement can be achieved by the elastic action of the elastic body 19. Will act on the entire waterproof packing 2, and
The water-stopping action of the water-stop packing 2 is exhibited well.

Incidentally, for example, a fluid such as water or air may be injected into the hollow portion 6 of the hollow tube to increase the elasticity of the hollow tube. Further, as the elastic body 19, for example, a shape memory resin material such as a shape memory PVC pipe provided by Sekisui Chemical Co., Ltd. is adopted, and the elastic body 19 is disposed in the storage portion 13 in a crushed shape, After attaching the mounting portion 5 to the end of the inner tube 1, the crushed elastic body 19 is restored to its original shape by steam heating the mounting portion 5, and the watertight packing 2 is removed. A configuration of pressing against the fitted portion 31 may be adopted.

The mounting portion 5 and the waterproof packing 2 may be provided in advance at the distal end of the small-diameter portion 32. Also, after the permanent waterproof packing 8 is deteriorated due to abrasion or the like, the distal end of the small-diameter portion 32 may be provided. It may be provided in the unit.

At the rear end of the tube member 25 at the front end and at the rear end of the intermediate tube member 26, a large-diameter portion having an inner peripheral diameter larger than the outer diameter of the watertight packing 2 is provided. When the mounting portion 5 does not exist, the distal end surface of the small-diameter portion 32 is pressed directly. When the mounting portion 5 exists, the side surface of the mounting portion 5, specifically, the pressing member 12 is pressed. A plurality of pressing jacks 10 (first pressing jack 28 and second pressing jack 29) for pressing are arranged at predetermined intervals in the circumferential direction.

The pressing jack 10 comprises a base 10a and a telescopic part 10b. The base 10a is connected to a large-diameter part of the outer tube 1 and the telescopic part 10b is a small-diameter part 32 of the inner tube 1. Alternatively, it is connected to the mounting portion 5 provided on the small diameter portion 32.

The pressing jack 10 is turned upside down, the base 10a is connected to the inner tube 1 (the tip of the middle tube 26 and the tip of the rear tube 27), and the elastic portion 10b is connected to the outer tube. Tube material 1 (rear end of tube material 25 at the tip and rear end of intermediate tube material 26)
May be adopted.

In the drawing, reference numeral 30 denotes a sliding material outlet 30 for leading a sliding material (such as bentonite) for reducing the frictional resistance between the pipe and the ground.

Since the first embodiment is configured as described above,
The waterproof packing 2 used in the middle-push method for preventing water leakage from the connecting portion of the respective tubular materials 1 can be replaced from the inside of the tubular material 1.
By exchanging the pipe, the excavation propulsion apparatus which is excellent in practicality and can arrange the pipe material 1 over a long distance.

Further, since the mounting position of the waterproof packing 2 is at the end of the inner tube 1, the mounting is easy. For example, if the used tube 1 conforms to the existing Japan Sewerage Standard (JSWAS). Even if it is a specified center-pushed tube, it can be easily remodeled into the first embodiment by providing the attachment portion 5 at the end of the tube material 1. So, for example,
The mounting part 5 and the watertight packing 2 can be mounted only when the permanent watertight packing 8 is worn. That is,
The first embodiment is excellent in a very general purpose example.

Further, even when the water-stop packing 2 and the mounting portion 5 must be finally removed, such as when constructing a sewer pipe (in this case, the pressing jack 10 is also removed).
The waterproof packing 2 and the mounting portion 5 can be easily removed.

Since the watertight packing 2 is mounted at the end of the inner tube 1, when the watertight packing 2 is worn and water leakage occurs, the water leakage can be immediately detected or visually confirmed. Thus, the watertight packing 2 can be repaired or replaced accurately.

Further, if the pushing movement of the pusher 7 is adjusted in accordance with the wear of the water-stopping packing 2 or the like, the water-stopping packing 2 can exhibit a good water-stopping action over a long period of time. Further, since the pushing body 7 is constituted by a set of the divided pushing bodies 18, the pushing of the divided pushing body 18 is increased only in the portion where the watertight packing 2 is worn, and the stopping of the watertight packing 2 is performed only in the worn portion. Water action can also be enhanced.

In the second embodiment, a mounting portion 5 is detachably provided at the end of the inner tube 1, that is, at the distal end of the small-diameter portion 32. In the storage unit 13,
An elastic body 19, specifically, a hollow tube made of rubber is provided, and the water-stop packing 2 is provided on the elastic body 19 in a superposed state.

In the second embodiment, the water-stop packing 2 is moved by the elastic action of the elastic body 19 to the inner circumferential surface of the outer tube 1, that is,
The structure is pressed against the fitted portion 31 so as to exhibit a good water stopping function, and its configuration is simpler and lower in cost than in the first embodiment.

Incidentally, as the elastic body 19, for example, the shape memory resin material exemplified in the first embodiment may be adopted.

The rest is the same as in the first embodiment.

In the third embodiment, a mounting portion 5 is detachably provided at the end of the inner tube 1, that is, at the distal end of the small-diameter portion 32. In the storage unit 13,
A plurality of elastic members 19, that is, spring members 19a are arranged side by side at predetermined intervals in the circumferential direction.
Is arranged.

In the third embodiment, as in the second embodiment, the configuration is simple and the cost is low. Also, the deteriorated spring body
By replacing 19a, the elastic action of the elastic body 19 can be favorably exhibited over a long period of time.

The rest is the same as in the first and second embodiments.

In the fourth embodiment, a mounting portion 5 is detachably provided at the end of the inner tube 1, that is, at the distal end of the small-diameter portion 32. In the storage unit 13,
It has a hollow part 6 inside, and is provided with a water-stop packing 2 which swells by injecting a fluid into the hollow part 6 and exerts a water-stopping action by the swelling.

The fluid to be injected into the hollow portion 6 may be a liquid such as water. However, in this case, if the swelling pressure is high, the swelling member 6 may be damaged. It is better to adopt.

In the fourth embodiment, the permanent watertight packing 8 is used.
Also, a permanent watertight packing 8 having a hollow portion 35 therein and swelling by injecting a fluid into the hollow portion 35 and exhibiting a water stopping action by the swelling is employed.

Therefore, according to the fourth embodiment, the permanent watertight packing 8 is not always bulged, but only the watertight packing 2 provided at the end of the inner tube 1 is bulged. Water leakage is prevented only by the water stopping function of the packing 2, and when the water stopping packing 2 is worn, the permanent water stopping packing 8 is bulged to prevent water leakage by the water stopping function of the permanent water stopping packing 8. In addition, the water-proof packing 2 can be replaced by contracting the worn water-proof packing 2, and the water-proof packing 2 can be replaced very satisfactorily.

The water-stop packing 2 having the hollow portion 6 is not of a type that swells by injection of a fluid, but is, for example, a shape memory resin material exemplified in the first embodiment having a water-stop function. May be.

The rest is the same as in the first and second embodiments.

The fifth embodiment is another example of the fourth embodiment, in which the same ordinary permanent watertight packing 8 as in the first to third embodiments is employed as the permanent watertight packing 8.

The rest is the same as in the fourth embodiment.

As described above, according to the first to fifth embodiments, the watertight packing 2 which can be replaced by the so-called middle-pressing method in which the frictional resistance does not increase even if the pipe material 1 is arranged over a long distance can be used. 1 can be arranged over very long distances.

Although the first to fifth embodiments have described the excavation propulsion apparatus for the middle-push method, adjacent pipes 1 are superimposed, and one pipe 1 is slid on another pipe 1. Any excavation propulsion device having such a configuration can be applied.

The configurations of the first to fifth embodiments may be used in an appropriate combination.

The same applies to the case where each of the front end tube 25, the middle tube 26, and the rear end tube 27 is a single tube.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a middle pressing method.

FIG. 2 is an explanatory enlarged side sectional view of a main part of a conventional excavation propulsion device for a middle-push method.

FIG. 3 is an explanatory enlarged side sectional view of a main part of the first embodiment.

FIG. 4 is an explanatory enlarged vertical sectional view of a main part of the first embodiment.

FIG. 5 is an explanatory enlarged side sectional view of a main part of a second embodiment.

FIG. 6 is an explanatory enlarged side sectional view of a main part of a third embodiment.

FIG. 7 is an explanatory enlarged side sectional view of a main part of a fourth embodiment.

FIG. 8 is an explanatory enlarged side sectional view of a main part of a fifth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe material 2 Waterproof packing 4 Excavation part 5 Mounting part 6 Hollow part 7 Pushing body 8 Permanent watertight packing 9 Opening 10 Press jack

Claims (10)

[Claims] An excavated portion is provided at the tip, and n pipes are disposed behind the excavated portion, and two adjacent pipes are provided in a fitted state, and the excavated portion excavates the ground. And an excavation propulsion device for slidingly propelling another tube material adjacent to one tube material, wherein an attachment portion is provided at an end of the inner tube material, and the attachment portion is provided with an inner portion of the two adjacent tube materials. A watertight packing for closing a gap between an outer peripheral surface of the tubular member and an inner peripheral surface of the outer tubular member. 2. An excavation portion is provided at a tip, and a first pipe material, a second pipe material,..., An n-th pipe material are disposed behind the excavation portion, and two adjacent pipe materials are covered. It is provided in the fitted state, excavates the ground by the excavation part, and slide-propelles the (n-2) -th pipe against the (n-1) -th pipe,
Subsequently, the propulsion of the (n-2) th pipe material is stopped, and
An excavation propulsion device for slidingly propelling a first pipe material with respect to an n-th pipe material, wherein an attachment portion is provided at an end of the inner tube material, and the attachment portion is provided with an inner portion of the two adjacent pipe materials. A watertight packing for closing a gap between an outer peripheral surface of the tubular member and an inner peripheral surface of the outer tubular member. 3. The excavation propulsion device according to claim 2,
The (n-2) -th pipe is provided with a pressing jack which presses the (n-1) -th pipe and pushes the (n-2) -th pipe forward with respect to the (n-1) -th pipe by a reaction force of the pressing. An excavation propulsion device characterized by the above-mentioned. 4. The excavation propulsion device according to claim 1, wherein the mounting portion is attached to an end surface of the inner tube. 5. The excavation propulsion device according to claim 1, wherein at least one of the mounting portion and the watertight packing is detachably provided. 6. The excavation propulsion device according to claim 1, wherein the watertight packing seals a gap between an outer peripheral surface of the inner tube and an inner peripheral surface of the outer tube at any time. Drilling propulsion device characterized by adopting waterproof packing. 7. The excavation propulsion device according to any one of claims 1 to 6, wherein the water stoppage packing has a hollow portion inside, and the water stoppage expands by injecting a fluid into the hollow portion. An excavation propulsion device characterized by using packing. 8. The excavation propulsion device according to claim 1, wherein a concave strip-shaped mounting portion having an opening that opens to an outer pipe material side is adopted as the mounting portion. Drilling propulsion equipment characterized. 9. The excavation propulsion device according to claim 1, wherein a vertically movable pusher is provided at a bottom portion of the mount, and the pusher is housed in the mount by pushing of the pusher. The excavation propulsion device, wherein the watertight packing is configured to contact the inner peripheral surface of the outer pipe material. 10. The excavation propulsion device according to claim 1, wherein the inner tubular member is a permanent stop that always abuts the outer peripheral surface against the inner peripheral surface of the outer tubular member to close a gap therebetween. An excavation propulsion device comprising a pipe member provided with a water packing.