JP2003027877A - Method for rotatively press-fitting cylindrical casing by shaft excavator, and counterweight for use in the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for rotatively press-fitting a cylindrical casing by a shaft excavator, which can carry out quick excavation of a shaft. SOLUTION: The shaft excavator includes a machine body 1, and functions to grasp the cylindrical casing 100 for embedding, which is erectly set on the ground G, and to press-fit the same into the ground by a press-fitting mechanism 9, a grasping mechanism 19, and a rotation driving mechanism 25. The press- fitting mechanism 9 is connected to a pressurizing frame 18, and bears the same above a reaction bearing frame 8 of the machine body 1 in a vertically movable manner. The grasping mechanism 19 for grasping the cylindrical casing 100, is borne above the pressurizing frame 18 in an expandable/contractible manner. The rotation driving mechanism 25 rotates the cylindrical casing 100. Then, a ground portion inside the cylindrical casing 100 is excavated by the shaft excavator, and ring weights 31 each equipped with a positioning means, are successively accumulated on the casing 100 according to increase in press- fitting resistance of the cylindrical casing 100, to thereby add a press-fitting load to the casing 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of rotary press-fitting a cylindrical casing by a shaft in a propulsion method and a shaft excavator in an all-casing method (Benot method), and more specifically, for example, propulsion and embedding a concrete pipe from a shaft. The present invention relates to a method for rotary press-fitting a cylindrical casing by a vertical shaft excavating device for constructing a vertical shaft for work or a cast-in-place pile at the time of tunnel construction.

[0002]

2. Description of the Related Art Conventionally, in this type of shaft excavating device, for example, Japanese Patent Application Laid-Open No. 1 (1999), which has been filed and published by the present applicant.
There is one having a configuration as disclosed in 1-210365 gazette.

In such a vertical shaft excavating device, as shown schematically in FIG. 14, for example, a driver's cab 2 and a rotary mount 3 are mounted on a machine body 1 composed of a caterpillar type endless track truck which can freely move on the ground G. It is equipped with a swivel control via the rotary base 3
The boom 4 is mounted on the upper part of the boom 4 so that it can be controlled up and down, and the excavator body 10 is suspended from and supported by the wire rope 6 from the tip of the boom 4 through the sheave 5,
Can be vertically controlled by winding and rewinding the wire rope 6 by the winch 7 installed on the rotary mount 3 via the rope tensioning device 5a, while the shaft of the machine body 1 can be rotated vertically. The casing gripping / swinging press-fitting mechanism 20 is vertically movably supported via a supported reaction force support frame 8.

This casing gripping / swinging press-fitting mechanism 20
Is fixed by the self-propelled operation of the airframe 1 at a hole drilling position in the shaft on the ground G, and the circular grip of the casing gripping / oscillating press-fitting mechanism 20 is connected by the vertical axis. After the cylindrical casing 100 for embedding is inserted into the frame 21 and installed upright on the ground G, the annular casing frame 21 is radially reduced by a drive mechanism (not shown) to grasp the cylindrical casing 100 and By rotationally controlling the annular gripping frame 21 to rotate in the circumferential direction, the cylindrical casing 100 is normally or reversely rotated at a desired angle in the circumferential direction to be repeatedly oscillated and rotated, while the weight of the cylindrical casing 100 is reversed. Force support frame 8
Pressure applying mechanism (not shown) such as a hydraulic jack installed in the
By applying a pressure load, the cylindrical casing 100 is pressed into the ground.

Then, the inner ground G of the cylindrical casing 100 after press-fitting is suspended by the excavator main body 10 and excavated by the grab bucket 12 whose opening and closing is controlled by the drive cylinder 11, and is gripped by the grab bucket 12. Excavated soil G held
1 is discharged to the outside, the annular gripping frame 21 of the casing gripping / swinging press-fitting mechanism 20 is extended in the radial direction to temporarily release the gripped state of the cylindrical casing 100 and move it upward. , Again, the cylindrical casing 100
The cylindrical casing 100 is further press-fitted into the ground by swinging and rotating the casing gripping / swinging press-fitting mechanism 20 by gripping, and by repeating these steps, another cylindrical casing 100 is welded or bolted. The all-casing vertical shaft is excavated by press-fitting to a predetermined set depth while connecting with each other.

[0006]

However, in the rocking and press-fitting means of the cylindrical casing by the above-described conventional shaft excavating device, the pressure load on the cylindrical casing 100 in the initial excavation stage is set on the reaction force supporting frame 8. Since the pressure is applied by the pressure applying mechanism (not shown), when the press-fitting resistance to the cylindrical casing 100 increases due to the frictional resistance to the shaft wall to be excavated with the press-fitting depth, the reaction force supporting frame 8 is With only the load, the reaction force against the press-fitting resistance of the cylindrical casing 100 becomes insufficient, so that the cylindrical casing 100 is not sunk and the cylindrical casing 100 cannot be smoothly press-fitted.

Therefore, conventionally, by mounting the rectangular parallelepiped weight member W on the front and rear reaction force supporting frames 8, the insufficient reaction force against the press-fitting resistance of the cylindrical casing 100 is compensated. As shown by the two-dot chain line in FIG. 14, when the weight member W is additionally loaded step by step according to the press-fitting resistance of the cylindrical casing 100, the loading height T of the weight member W becomes too high. There is a problem in that the boom 4 cannot be swung smoothly because it interferes with the swing operation of the boom 4 when the cylindrical casing 100 is replenished or when the excavator body 10 is pulled up. there were.

Further, since the cylindrical casing 100 is of a revolving type in which the cylinder casing 100 is normally rotated and reversely rotated at a desired angle in the circumferential direction,
There is a problem that the efficiency of press-fitting the cylindrical casing is low. Therefore, an object of the present invention is to provide a method for rotationally press-fitting a cylindrical casing by a vertical shaft excavator, which enables rapid vertical shaft excavation work.

[0009]

In order to solve the above problems, a rotary press-fitting method according to a first aspect of the present invention comprises a pressurizing means for connecting and supporting a pressurizing frame to a reaction force supporting frame of an airframe so as to be vertically movable. A cylindrical casing for embedding which is erected on the ground by a holding means for a cylindrical casing which is supported on the pressure frame so as to be expandable and contractible, and a rotation driving means which rotates the cylindrical casing together with the holding means for the cylindrical casing. While holding the ring, it is rotationally press-fitted into the ground, the internal ground of the cylindrical casing is excavated by a vertical shaft excavator equipped with the machine body, and a ring provided with a positioning means is provided in accordance with an increase in the press-fitting resistance of the cylindrical casing. -Shaped counterweights are sequentially stacked on the casing to apply a press-fitting load.

According to a second aspect of the present invention, the positioning means provided in the counterweight used in the rotary press-fitting method according to the first aspect is recessed on the lower surface so as to be aligned with the upper edge of the casing. And a plurality of positioning holes provided on the lower surface in the circumferential direction, and a projection provided on the upper surface and fitted into the positioning hole of the counterweight positioned at the upper position, thereby speeding up the stacking operation of the counterweights. It is characterized by enabling.

According to the present invention, the counterweights can be quickly and stably stacked by the positioning means according to the increase in the press-fitting resistance of the cylindrical casing, so that the rotary press-fitting work can be smoothly progressed and the vertical shaft excavating work can be carried out quickly. It can be carried out.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention.
~ It demonstrates with reference to FIG. FIG. 1 is an overall configuration diagram schematically showing a shaft excavating device of the present embodiment. 2 and 3 are plan views showing a gripping / rotating press-fitting mechanism of a cylindrical casing to be embedded. 4, 5, and 6 are respectively AA of FIG.
It is a sectional view, a B arrow view, and a C arrow view. 7 and 8 are explanatory views of the main part. In addition, FIG. 9 is an explanatory diagram of a rotary press-fitting preparation process. It should be noted that parts having the same configuration as the conventional shaft excavator shown in FIG. 10 will be described using the same reference numerals.

As shown in FIG. 1, the shaft excavating device of this embodiment has a machine body 1 composed of a caterpillar type endless track carriage that is capable of self-propelled on the ground G, and a rotary mount 3 on the machine body 1 so as to control the turning. It has a driver's cab 2 mounted on it, and a telescopic boom 4 mounted on a rotary base 3 so as to be able to control ups and downs, and a wire rope 6 is hung on the boom 4 via a sheave 5 at its tip. Has been done.

An excavator body 10 is detachably suspended from the tip of the boom 4 via a wire rope 6, and the excavator body 10 is attached to a rear end of the operator's cab 2 by a winch 7. The hoisting and rewinding operations allow the hoisting control. Further, a grab bucket 12 whose opening and closing is controlled by a drive cylinder 11 is suspended under the excavator body 10.

At the front part of the machine body 1 (on the left end side in FIG. 1), one end side of the reaction force supporting frame 8 located at the lower part is rotatably supported by a detachable horizontal shaft 36 so as to be vertically rotatable. The reaction force support frame 8 is a steel cylindrical casing 1 to be buried.
A press-fitting mechanism 9 (pressurizing means) for press-fitting 00 in the vertical direction is provided, and a gripping / rotating drive mechanism 20 (grasping means, rotary driving means) for gripping / rotatably driving the cylindrical casing 100.
Is supported so that it can move up and down.

As shown in FIGS. 2 and 3, the gripping / rotating drive mechanism 20 comprises a gripping mechanism 19 for gripping the cylindrical casing 100 and a rotary drive mechanism 25 for rotationally driving the casing 100.

The gripping mechanism 19 (grasping means) has a substantially annular gripping frame 21 and a tightening cylinder 2 as main components.
3 and 3. The annular gripping frame 21 has a vertical axis 22.
Via a pair of movable arc-shaped links (movable arms) 21a
Is connected to a fixed arc-shaped link (fixed arm) 21b so as to be openable and closably movable, and is composed of three arc-shaped links 21a, 21b, 21a arranged in a substantially circular shape as a whole, and has a cylindrical shape inside thereof. The casing 100 is inserted.
The vertical axis 22 connecting the links 21a and 21b is vertically fixed on a ring-shaped bracket 26 that serves as a support base for a rotary drive mechanism 25 (rotary drive means) described later (see FIG. 4 for the bracket 26). ). Therefore, the vertical axis 22 (that is, the annular gripping frame 21) can rotate together with the bracket 26. The links 21a at both ends of the annular gripping frame 21 are connected to each other via a telescopic tightening cylinder 23 so that the diameter can be reduced or expanded, and the outer peripheral surface of the cylindrical casing 100 can be gripped and opened.

Then, in a state in which the annular holding frame 21 is reduced in diameter and holds the cylindrical casing 100, the rotary drive mechanism 25 arranged on the reaction force supporting frame 8 rotates the cylindrical casing 100 via the annular holding frame 21. To drive. The direction of rotation can be rotated in either direction.

The rotary drive mechanism 25 (rotary drive means)
Is composed of a plurality of (three in this case) hydraulic motors 24 arranged outside the cylindrical casing 100 and a mechanism for transmitting the driving force of each hydraulic motor 24, and is configured as follows.

As shown in FIG. 4, a case (housing)
Each of the case rotation type hydraulic motors 24 configured such that the side thereof is rotated is mounted inside the pressurizing frame 18 by the bolts 13, and the vertically arranged shaft side 24b is fixed by the bolts 13, and is attached to the housing 24a side. The annular pinion 16 is fitted and fixed, and the shaft portion 24d is attached to the pinion 16.
The lower surface plate 24c having is fixed by a plurality of bolts,
The shaft portion 24d is rotatably supported on the lid member 18c side, and the housing 24a is rotatably supported. The pressurizing frame 18 supporting the hydraulic motor 24 is movably supported on the reaction force supporting frame 8 via four press-fitting cylinders 29 (described later) (see FIG. 1). When high-pressure oil is supplied to the hydraulic motor 24 through the flow path 15, the housing 24a and the pinion gear 16 integrated around the housing 24a rotate. The three hydraulic motors 24 rotate synchronously.

On the other hand, on the inner peripheral side of the pressure frame 18, a steel ring-shaped race member 18a having an annular groove having a semicircular cross section on the outside is fixed by a bolt 27, and on the outer side of the race member 18a. , Through a large number of steel balls 17a,
A ring gear 17 having an annular groove having a semicircular cross section inside is rotatably held. The outer teeth of the ring gear 17 mesh with the drive pinion gear 16 of the hydraulic motor 24. The pressure frame 18 has a cover 18b,
It is protected from the outside by 18c.

Further, a ring-shaped bracket 26 is fixed onto the ring gear 17 by bolts 26a, and the annular gripping frame 21 is connected to the ring gear 17 via a vertical axis 22 which is vertically fixed on the bracket 26. It can be rotated together with. A friction material 28 is fixed to the contact portions of the links 21a and 21b that contact the outer periphery of the cylindrical casing 100.

The press-fitting mechanism 9 (pressurizing means), as shown in FIGS. 3, 5 and 6, has a reaction force support frame 8 having outriggers 30 at four corners, and a reaction force support frame thereof. 8 press-fitting cylinders on the upper side (hydraulic jack)
The pressure frame 18 is connected via 29, and a ring-shaped weight 31 (counterweight), which is shown in detail in FIGS. The middle portion of the large-diameter upper vertical cylindrical body 29a is fixed to approximately four corners of the pressing frame 18, and the small-diameter lower vertical cylindrical body 29b is slidably arranged on each of the large-diameter upper vertical cylindrical bodies 29a. And the small-diameter lower vertical cylindrical body 29b.
A lower end portion of the large-diameter upper vertical cylinder 29a and a small-diameter lower vertical cylinder 29b.
Are connected to the press-fitting cylinder 29, and by expanding and contracting each hydraulic cylinder 29, the pressurizing frame 18 and the reaction force supporting frame 8 can be moved relatively toward and away from each other in the vertical direction. .

The reaction force support frame 8 has four outriggers 30 fixed to the four corners thereof to expand and contract, so that the length of each outrigger 30 can be increased regardless of whether the ground G is horizontal or inclined. By adjusting the height, the reaction force support frame 8 can be brought into a horizontal state parallel to the horizontal plane, and the pressure frame 18 connected thereto can also be brought into a horizontal state parallel to the horizontal plane. Thus, the reaction force support frame 8 and the pressure frame 18 connected to the reaction force support frame 8
By making the cylinder horizontal,
Can be rotationally press-fitted vertically to the ground G.

When the ground G is horizontal, the outrigger 30 may be shortened and the reaction force support frame 8 may be seated on the ground G before construction. In this case, the outrigger 30 may or may not be seated on the ground. In the case of this embodiment, with the outrigger 30 shortened, the lower surface of the reaction force support frame 8 and the outrigger 3 are
The lower end surface of 0 is set to be substantially the same surface.

With respect to the sloping ground G, each outrigger 30 of the reaction force supporting frame 8 is seated on the ground G, and the respective extension amounts thereof are adjusted so that the reaction force supporting frame 8 floats and is in a horizontal state. To use in.
(See FIGS. 11 to 13) Whether the ground G is in the horizontal plane state or the inclined plane state, the weight of the pressure frame 18 and the reaction force support frame 8 and the like can be used as the pressing load when the cylindrical casing 100 is rotationally press-fitted. . In addition, each outrigger 30 can perform a synchronous operation and an independent operation.

The pressurizing frame 18 can move up and down integrally with the gripping / rotating drive mechanism 20 with respect to the reaction force supporting frame 8 as the press-fitting cylinder 29 attached thereto expands and contracts. The four press-fitting cylinders 29 operate synchronously. The reaction force support frame 8 supports a reaction force that acts as a reaction force when the pressure frame 18 is pressed and rotated, and transmits a part of the reaction force (particularly, the rotation force) to the machine body 1. , Supported.

The ring-shaped weight 31 shown in FIG. 7 has the mass of the pressurizing frame 18 and the press-fitting mechanism 9 and the cylindrical casing 1
00 is a member for placing on the upper edge of the cylindrical casing 100 to compensate for the lack of mass when the pressure input to 00 is insufficient, and as shown in FIG. 8 (partial cross-sectional view of FIG. 7), a plurality of members may be provided as necessary. The weight 31 is overlapped and used.

The positioning means included in the weight 31 is constructed as follows. That is, as shown in FIG. 7B, a recess 32 is formed on the lower surface of the weight 31, and the vertical surface of the recess 32 has a diameter that is close to or engages with the outer diameter (outer peripheral surface) of the cylindrical casing 100. The inner end edge of the flat lower surface of the recess 32 is formed to have substantially the same diameter as the inner diameter of the cylindrical casing 100. Further, a positioning hole 33 is provided on the lower surface at a position that divides the weight 31 into two at equal angular intervals in the circumferential direction, and the positioning hole 33 is provided at a corresponding position on the upper surface when superposed with a higher-ranking counterweight. Is fitted with the protrusion 34,
Positioning (prevention of displacement) is performed. The projection 34 and the positioning hole 33 have a common vertical center axis, and
The lateral width dimension of the protrusion 34 is set to be slightly smaller than the diameter of the hole 34. Further, the projection 34 is provided with a hole 34a for lifting and carrying operation.

Next, the rotary press-fitting process of the cylindrical casing 100 by the shaft excavating device of this embodiment will be described.
As shown in FIG. 9, in the self-propelled operation of the machine body 1, the gripping / rotating drive mechanism 20 supported by the reaction force support frame 8 connected and supported by the machine body 1 by the horizontal shaft 1a is moved to the vertical shaft on the predetermined ground G. Place it in the hole drilling position. In the figure, reference numeral 35 denotes a fixed-length wire rope for transportation, and a link 35a for connection is provided at both ends thereof.
Is equipped with. Each of the connecting links 35a on one end side of the plurality of transport wire ropes 35 has a press-fitting cylinder 2
The steel upper bracket 29c of No. 9 is detachably connected to the through hole of the steel upper bracket 29c by the horizontal shaft 35b, and each of the other connecting links 35a is detachable from the steel bracket 4a of the telescopic boom 4. Connect with a connecting pin 35c,
When the boom 4 is rotated so as to stand upright, the carrying state as shown in FIG. 9 can be obtained. In this state, the cylindrical casing 100 is transferred and installed at a predetermined vertical hole drilling position.
Is suspended in the shaft excavator.

When the ground G is horizontal, the reaction force support frame 8 is placed on the ground G and the outriggers 30 are shortened. At this time, the pressure frame 18 is held horizontally. Next, the press-fitting cylinder 29 is extended, the pressurizing frame 18 is disposed so as to be located at the upper high level position, and at that time, when the cylindrical casing 100 is gripped by the gripping means on the upper part of the pressurizing frame 18,
The state shown in FIG. 10 is obtained. In this case, the cylindrical casing 100 can be gripped while standing upright on the ground.

With respect to the sloping ground G, the outriggers 30 are expanded and contracted to bring the reaction force support frame 8 into a horizontal state, and the press-fitting cylinder 29 is extended with respect to the reaction force support frame 8. When the pressure frame 18 is lifted so as to be located at the upper high level position, and the cylindrical casing 100 is gripped by the gripping means at the upper part of the pressure frame 18 at that time, the state shown in FIG. 12 is obtained.

In this state, the cylindrical casing 100 is placed upright in the annular holding frame 21 of the holding / rotating drive mechanism 20, and is also placed upright at a right angle to the ground G, and the tightening cylinder 23. Thus, the annular grip frame 21 is contracted in the radial direction to grip the outer periphery of the cylindrical casing 100.

Then, the press-fitting cylinder 29 is shortened, and the mass of the press-fitting mechanism 9 and the gripping / rotating drive mechanism 20 is added to the cylindrical casing 10 as shown in FIG. 10 or 13.
The total mass including the mass of 0 itself is applied to the tip end (lower end) of the cylindrical casing 100 as a press-fit load,
The hydraulic motor 24 rotationally drives the annular gripping frame 21 gripping the cylindrical casing 100 at a predetermined rotation speed, and the press-fitting cylinder 29 is contracted to compress the pressurizing frame 1.
Cylindrical casing 1 through 8 (annular gripping frame 21)
Press 00 into the ground. One stroke of the press-fitting cylinder 29 becomes one stroke of press-fitting the cylindrical casing 100.
It should be noted that, when the press-fitting does not proceed smoothly, it is possible to easily rotate the cylindrical casing 100 in the reverse direction, or to repeatedly perform the forward and reverse rotations, if necessary.

After one step of the press-fitting is completed, the gripping state by the ring-shaped gripping frame 21 is released, the press-fitting cylinder 29 is set to the most extended state, and the ring-shaped gripping frame 21 is raised so that the upper part of the cylindrical casing 100 can be gripped. And hold again. In this way, the rotational press-fitting operation is repeated to press-fit the cylindrical casing 100.

When the press-fitting resistance increases due to the frictional resistance with the ground as the press-fitting depth increases and the press-fitting load becomes insufficient, the weight 31 is stacked on the upper end of the cylindrical casing 100. Make up for insufficient press-fitting load. The stacking operation of the weights 31 is performed by appropriately inserting the locking metal fittings in a strip such as a rope having detachable locking metal fittings (not shown) at the end portions (or both end portions) into holes 34a.
And the end metal fitting (or intermediate part) of the strip is suspended and conveyed by a crane (not shown),
The shaft excavator shown in the figure can be used for quick operation, and the stacked weights 31 are stable.

After the press-fitting reaches a predetermined depth, the inner ground G of the cylindrical casing 100 is excavated by the grab bucket 12 which is suspended by the excavator body 10 and whose opening and closing is controlled by the drive cylinder 11. Discharge excavated soil to the outside. Thus, the above steps are repeated and the cylindrical casing 10
While adding 0, press fit to a specified depth.

In the above-described embodiment, two sets of positioning holes 33 are provided on the lower side and two sets of projections 34 are provided at corresponding positions on the upper surface at equal angular intervals of 180 degrees in the circumferential direction of the weight 31, but three sets are provided. You may provide it at intervals above.

[0039]

As is apparent from the above description, according to the present invention, the counterweight is quickly and stably provided by the positioning means according to the increase in the press-fitting resistance of the cylindrical casing accompanying the increase in the press-fitting depth. Since they can be stacked, the rotary press-fitting work can proceed smoothly, and the shaft excavation work can be performed quickly.

Further, in the case of the present invention, continuous rotation can be performed in comparison with the conventional case of the repetitive rotation type in which the cylindrical casing is normally or reversely rotated at a desired angle in the circumferential direction. The press-fitting efficiency is high and the construction efficiency can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram schematically showing a shaft excavating device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a gripping / rotating press-fitting mechanism of a cylindrical casing according to an embodiment.

FIG. 3 is an enlarged view of a main part of FIG.

4 is a cross-sectional view taken along the line AA of FIG.

5 is a view on arrow B of FIG. 3. FIG.

FIG. 6 is a view on arrow C of FIG.

FIG. 7A is a plan view of a main part of one embodiment,
FIG. 3B is a side view including a partial cross section of the main part.

FIG. 8 is a partially enlarged cross-sectional view of a main part of one embodiment.

FIG. 9 is an explanatory diagram of a rotary press-fitting preparation process of one embodiment.

FIG. 10 is an explanatory view showing a state in which the press-fitting cylinder is shortened and the cylindrical casing is press-fitted into the ground in the horizontal ground.

FIG. 11 is an explanatory diagram showing a state in which a vertical shaft excavating device is installed on a sloping ground.

FIG. 12 is an explanatory view showing a state where the press-fitting cylinder is in an extended state on the sloping ground.

FIG. 13 is an explanatory view showing a state where the press-fitting cylinder is shortened and the cylindrical casing is press-fitted into the ground in the sloping ground.

FIG. 14 is an overall configuration diagram schematically showing a conventional shaft digging device.

[Explanation of symbols]

1 Airframe 2 Driver's cab 3 Rotating platform 4 Boom 4a Steel bracket 5 Sheave 6 Wire rope 7 Winch 8 Reaction force support frame 9 Press-fitting mechanism (pressurizing means) 10 Excavator body 11 Drive cylinder 12 Grab bucket 13, 14, 18b, 27 bolts 15 flow paths 16 pinion gears 17 ring gears 17a balls 18 pressure frames 18a race members 18b, 18c covers 19 gripping mechanism (gripping means) 20 gripping / rotating drive mechanism 21 annular gripping frames 21a, 21b link (movable arm or fixed arm) 22 vertical axis 23 tightening cylinder 24 hydraulic motor 24b shaft side 24a housing 25 rotary drive mechanism (rotary drive means) 26 bracket 28 friction material 29 press fit cylinder 29a large diameter upper vertical cylinder 29b small diameter lower vertical cylinder 29c steel upper bracket 30 Outrigger 3 Weight (counterweight) 32 recess 33 hole 34 projection 35 for conveying wire rope 35a connecting link 35b horizontal axis 35c connecting pin 36 horizontal axis 100 casing

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Norio Enkawa             Sumiyoshi Heavy Industry 8-46, Chofu Ogimachi, Shimonoseki City, Yamaguchi Prefecture             Business F term (reference) 2D029 DC01 PA07 PB05 PC01 PD04                 2D050 CB22 CB23 EE14

Claims (2)

[Claims] 1. A pressurizing means for connecting and supporting a pressurizing frame to a reaction force supporting frame of an airframe so as to be vertically movable, a gripping means for a cylindrical casing which is supported on the pressurizing frame so as to be expandable and contractible, and the cylindrical casing. The cylindrical casing for embedding is gripped by the rotation driving means for rotating the cylindrical casing together with the gripping means and is rotationally press-fitted into the ground, and the vertical ground excavating device equipped with the machine body excavates the inner ground of the cylindrical casing. In addition, according to the increase in the press-fitting resistance of the cylindrical casing, a ring-shaped counterweight provided with a positioning means is sequentially stacked on the casing, and a press-fitting load is applied to the cylindrical casing by a vertical shaft excavating device. How to press-fit. 2. A counterweight used in the method for rotationally press-fitting a cylindrical casing according to claim 1, wherein the positioning means has a recess on the lower surface that is fitted to the upper edge of the casing and is centered. , Consisting of a plurality of positioning holes provided in the lower surface in the circumferential direction and projections that are provided in the upper surface and that fit into the positioning holes of the upper counterweight, enabling quicker operation of stacking counterweights A counterweight characterized by