JP3340980B2 - Underground drilling rig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground hole excavation apparatus for building a foundation of a civil engineering building.

[0002]

2. Description of the Related Art Underground holes are excavated for driving foundation piles of civil engineering buildings and for ground improvement. The underground excavation device is configured by projecting a drilling claw on a shaft that is driven and rotated by a drive unit.The shaft is mounted vertically on the work machine, and it is lowered by rotating it. , Excavating underground holes.

[0003] In addition, for the purpose of increasing the supporting force of the foundation pile, a locally enlarged portion is formed in the underground hole. As a means for forming the enlarged diameter portion, it is known to use an excavator provided with a claw for excavation of the enlarged diameter portion, which performs a projecting / retracting operation by forward / reverse rotation of a shaft (for example, see Japanese Unexamined Patent Application Publication No. -298982).

In this type of excavating apparatus, when the shaft is rotated forward (when the shaft is lowered to excavate an underground hole), a claw for excavating the enlarged diameter portion is retracted, and when the shaft is rotated reversely (when the enlarged diameter portion is formed). ) To make the claws protrude.

[0005]

However, the conventional underground excavation apparatus of this kind has the following problems (1) and (2). (1) When the shaft is switched from forward rotation to reverse rotation and the claws for excavating the enlarged diameter part suddenly protrude, the load (resistance of the soil) applied to the shaft suddenly becomes excessively large, and the shaft cannot be completely turned. , The shaft is damaged. Alternatively, a large-sized one having a large torque is required as a driving unit (motor) for rotating the shaft. Such a problem is particularly likely to occur when the underground hole is dug deep or when the soil has a high resistance. (2) The claw for excavating the enlarged diameter portion protrudes when the shaft is rotated in the reverse direction, and excavates the enlarged diameter portion. It is not possible to ascertain whether or not the part is excavated, in particular whether all the claws provided at a pitch in the longitudinal direction of the shaft are normally projecting and excavating the enlarged part.

Accordingly, an object of the present invention is to provide an underground hole excavator capable of solving the above problems.

[0007]

According to the present invention, there is provided an apparatus for excavating an underground hole, comprising: a shaft; a block mounted on the shaft;
And a claw for extruding a large-diameter portion that is protruded from the shaft and inserted into a hole formed in the block. The claw is drawn into the block when the shaft rotates forward, and projects from the block when the shaft rotates reversely. And mounted on the shaft.
A flange attached thereto, and the flange is attached to the flange.
Was attached .

The underground hole excavating apparatus of the present invention further comprises a shaft, a claw for extruding a large diameter portion, which is protruded from the shaft and protrudes when the shaft rotates forward and protrudes when the shaft rotates reversely, and retracts and protrudes the claw. A movable element that is displaced in conjunction with the operation, and detects the protrusion of the claw from the displacement of the movable element.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial perspective view of an underground excavator, FIG. 2 is a partially exploded perspective view of an underground excavator, FIG.
(A) is a partial perspective view of a shaft unit of an underground hole excavator, FIG. 3 (b) is a perspective view of a movable unit of an underground hole excavator, and FIGS. Front view showing the positional relationship between the mounting body of the excavator and the connector, FIG. 5 is a plan view of a first unit of the underground excavator, FIG. 6 is a plan view of a third unit of the underground excavator, 7A is a plan sectional view of the underground hole excavator at the time of forward rotation, FIG. 7B is a partial sectional view of the same,
FIG. 8A is a cross-sectional plan view of the underground excavator at the time of reverse rotation,
8 (b) is a partial sectional view of the same, FIG. 9 (a) is a side view of the underground excavator at the time of normal rotation, and FIG. 9 (b) is a side view of the underground excavator at the time of reverse rotation. FIG. 10A is a side view when the shaft rotates forward, and FIG. 10B is a side view when the shaft rotates reversely.

1 to 3, the underground excavation apparatus includes a shaft unit A shown in FIG. 3 and a movable unit B mounted on the shaft unit A.

First, the shaft unit A will be described. FIG.
In FIG. 5 and FIG. 5, reference numeral 1 denotes a shaft, and a center hole 2 is formed in the center of the shaft for flowing a ground improvement liquid such as cement milk or mortar. A plurality of first units a are mounted on the shaft 1 at a pitch in the longitudinal direction, and a second unit b is mounted above the first unit a. As shown in FIG. 5, the first unit a is mounted on the shaft 1 as a set of two units.

3 and 5, the first unit a
Is composed of a bearing 3 and arcuate mounting bodies 4 and 5 projecting from the bearing 3 to both sides.
Is mounted on the shaft 1 so as to hold the shaft. The base end of a rod-shaped enlarged portion excavating claw 6 is attached to the bearing 3 by a pin 7 so as to be rotatable (swingable) in the horizontal direction. This nail 6
Is for forming the enlarged diameter portion in the underground hole. 9,
Reference numeral 10 denotes a pin hole for inserting the pin 7 opened in the base end of the claw 6 and the bearing 3. In FIG. 5, the pin hole 10 is a long hole elongated in the radial direction of the shaft 1.

In FIG. 3A, the second unit b is
A ring 11 mounted on the shaft 1 and a stator 12 consisting of small pieces mounted on the ring 11 at a distance from each other;
It consists of thirteen. First unit a shown in FIG.
And the second unit b rotate forward and backward integrally with the shaft 1. The forward rotation is the rotation direction R when excavating an underground hole, and the reverse rotation is the rotation direction L when excavating an enlarged diameter portion (see FIG. 9).

Next, the movable unit B will be described with reference to FIG. The movable unit B is composed of a third unit c and a fourth unit d spaced apart from each other in the vertical direction, and the third unit c and the fourth unit d are connected by a rod 20 as an upright connecting member. . As will be described later, the block 23 provided on the movable unit B and the shaft 1 or the claw 6 mounted on the shaft 1 horizontally rotate relative to each other within a rotation range defined by the rotation range defining means.

In FIG. 3B and FIG. 6, the third unit c includes two upper and lower ring-shaped mounting bodies 21 loosely attached to the shaft 1 and a plurality of (a plurality of) projecting sideways from the mounting body 21. In this example, two flanges 22 are provided. Up and down 2
A block 23 is mounted between the two flanges 22, and the upper and lower mounting bodies 21 are connected by a connector 24. The block 23 has a hole 25 into which the claw 6 is inserted so as to be retractable and protrudable. In the first unit a and the third unit c, a plurality of claw units e (FIGS. 1 and 2) for excavating the enlarged diameter portion are arranged at a pitch in the longitudinal direction (vertical direction) of the shaft 1. . FIG.
As shown in FIG. 9A and FIG. 9, a plurality of rods 20 (five in this example) are provided in the length direction of the shaft 1. The blocks 23 of the claw unit e provided at a pitch in the longitudinal direction of the shaft 1 are linked and connected by a rod 23, and each block 23 rotates simultaneously with respect to the shaft 1.

In FIG. 3B, the fourth unit d is
It comprises upper and lower two rings 26, 27 and a mover 28 mounted on the rings 26, 27. As shown in FIG. 1, the rings 26 and 27 are loosely attached to the shaft 1 so as to sandwich the ring 11 from above and below.
2 and the stator 13. The second unit b and the fourth unit d constitute a detection unit f that detects the retraction and protrusion of the claw 6, and are disposed above the shaft 1 (FIGS. 1 and 2). In FIG. 4, the connector 24 is disposed between the mounting body 4 and the mounting body 5. The interval T between the mounting bodies 4 and 5 is larger than the width of the connector 24. Therefore, the connector 24 moves in the horizontal direction (right direction R,
It turns (idle) to the left (L) and selectively comes into contact with the mounting body 4 and the mounting body 5. The mounting bodies 4 and 5 and the connector 24 serve as rotation range defining means for defining a rotation range in which the movable unit B including the block 23 rotates horizontally relative to the shaft 1 or the claw 6.

The first unit a and the second unit b shown in FIG. 3A are fixed to the shaft 1,
The movable unit B including the third unit c and the fourth unit d shown in FIG. 3B is rotatably mounted around the shaft 1 so as to be freely rotatable therewith. 1 and a horizontal rotation relative to a predetermined angle. The predetermined angle is determined by the distance T, that is, the distance by which the connector 24 constituting the rotation range defining means can move (rotate) between the mounting body 4 and the mounting body 5.

FIGS. 1, 4 (a), 7, 9 (a), and 10 (a) show the shaft 1 driven by a driving unit (not shown).
Shows a state in which an underground hole is excavated while descending while rotating forward (arrow R). In this state, in FIG. 7, the third rotation including the block 23 is performed due to the reaction force FL received from the soil in the underground hole due to the forward rotation R of the shaft 1.
The unit c relatively rotates with respect to the shaft 1 in the rotation direction R and the opposite direction L, whereby the claw 6 is pulled in the block 23 while rotating inward N1 about the pin 7 as a center.
The protruding length L1 of the claw 6 from the shaft 1 is reduced, thereby excavating the underground hole H (see also FIG. 9A). In FIG. 9, reference numeral 10 denotes an excavator attached to the lower end of the shaft 1. In FIG. 7, θ1 represents the bearing 3 and the pawl 6 at this time.
Angle. In this state, as shown in FIGS. 1 and 4A, the mounting body 4 comes into contact with the connector 24. Also, as shown in FIGS. 1 and 10A, the mover 28 is displaced toward the stator 12 side.

FIG. 4B, FIG. 8, FIG. 9B, FIG.
(B) shows a state where the shaft 1 is rotated in the reverse direction (arrow L) to form the enlarged diameter portion D by the claw 6. In this state, in FIG. 8, the third unit c moves relative to the shaft 1 in the direction opposite to the rotation direction L due to the reaction force FR from the soil received by the shaft 1 rotating in the reverse direction L. The bearing 3 that rotates and has the pawl 6 axially attached thereto is the shaft 1
And the claw 6 protrudes outward from the block 23 while rotating outwardly around the pin 7 and overcoming the sliding contact resistance with the inner surface of the hole 25,
The protruding length L2 of the claw 6 from the shaft 1 increases, thereby excavating the enlarged diameter portion D (see also FIG. 9B). θ2 is the angle between the bearing 3 and the pawl 6 at this time. In this state, as shown in FIG. 4B, the mounting body 5 comes into contact with the connector 24.

In this state, the mover 28 is displaced toward the stator 13 as shown in FIG. That is,
From the relative displacement of the mover 28 with respect to the shaft 1 or the stators 12 and 13, the position of the claw 6 (whether the claw 6 is pulled into the block 23 or protrudes from the block 23 and excavates the enlarged diameter portion D) is detected. can do.
In the present embodiment, the stators 12 and 13 and the mover 2
8 is above the ground and is therefore visible to the operator.

This underground hole excavator is constructed as described above. Next, the operation of excavating an underground hole will be described. In FIG. 1, a working machine (not shown) with a shaft 1 upright.
While rotating a shaft 1 in a forward rotation R by driving a drive unit such as a motor provided in a working machine,
, The underground hole H is excavated. At this time, as shown in FIG. 7, the claw 6 is retracted into the block 23 (projection length L1).

When the underground hole H is excavated to a predetermined depth,
The shaft 1 is rotated backward L. Then, the claw 6 protrudes outward from the block 23 as shown in FIG.
2) The enlarged diameter portion D is formed. In this case, the claw 6 gradually protrudes from the protruding length L1 to the protruding length L2 while overcoming the excavation resistance. Therefore, even if the shaft 1 is switched from the normal rotation R to the reverse rotation, an excessive load is suddenly applied to the driving unit. Therefore, the claw 6 excavates the enlarged diameter portion D while gradually projecting from the block 23. Also, the nail 6 is a block 23
When the claw 6 protrudes from the block 23, the sliding contact resistance between the claw 6 and the inner surface of the hole 25 acts as a force for suppressing the claw 6 from suddenly protruding. I do.

The claw 6 performs a retracting / protruding operation in the hole 25 of the block 23, so that the block 23 serves as a guide portion for the retracting / protruding operation of the claw 6. Therefore, when the enlarged diameter portion D is excavated with the claw 6, the rattling of the claw 6 is prevented, and the enlarged diameter portion D can be stably excavated. And enlarged diameter part D
Is formed, the shaft 1 is rotated in the forward direction R, and the pawl 6 is rotated.
Is pulled into the block 23, and the shaft 1 is pulled up to the ground. When the underground hole is excavated as described above, it is preferable to flow the ground improvement liquid into the center hole 2 of the shaft 1 and discharge the soil from the lower end portion of the shaft 1 to agitate the soil in the underground hole. Mix.

As shown in FIGS. 10A and 10B, the relative position of the mover 28 with respect to the stators 12 and 13 is displaced during forward rotation and reverse rotation. Also, the stators 12 and 13
The mover 28 is above the shaft 1 and is exposed on the ground. Therefore, by checking the displacement by visual inspection of the operator, it can be confirmed whether or not the claws 6 project outward to form the enlarged diameter portion D. Note that the relative displacement of the mover may be detected by a sensor such as a position sensor, and the worker may be notified by a notification means such as a buzzer, a notification lamp, and a display. Further, since a plurality of claw units e provided at a pitch in the longitudinal direction of the shaft 1 are linked and connected by the rod 20, all the claws 6 perform the pull-in / projection operation in conjunction with each other. Therefore, mover 2
By the displacement of 8, the positions of all the claws 6 in the longitudinal direction of the shaft 1 can be known, and it can be detected whether or not all the claws 6 are excavating the enlarged diameter portion D. Also, the plurality of claws 6 provided at a pitch in the longitudinal direction of the shaft 1 can perform the pulling-in / projecting operation all at the same time and substantially integrally.

The present invention is not limited to the above embodiment, and various design changes are possible. For example, in the above embodiment, the claw is fixed to the shaft and the block is rotated with respect to the shaft and the claw, but the block is fixed to the shaft and the claw is rotated with respect to the shaft and the block. The point is that rotation and displacement are relative.

[0026]

As described above, according to the present invention, when the shaft is rotated in the reverse direction, the enlarged diameter portion is stably and reliably excavated by the claws while gradually projecting the claws from the block. Can be. In addition, it is possible to easily confirm whether or not the claws protrude outward to excavate the enlarged diameter portion.

[Brief description of the drawings]

FIG. 1 is a perspective view of an underground hole excavator.

FIG. 2 is an exploded perspective view of an underground hole excavator.

3A is a perspective view of a shaft unit of an underground excavation apparatus. FIG. 3B is a perspective view of a movable unit of the underground excavation apparatus.

FIG. 4A is a front view showing a positional relationship between a mounting body of an underground excavation apparatus and a connector. FIG. 4B is a front view showing a positional relation between a mounting body of an underground excavation apparatus and a connector.

FIG. 5 is a plan view of a first unit of the underground excavation apparatus.

FIG. 6 is a plan view of a third unit of the underground excavation apparatus.

FIG. 7A is a cross-sectional plan view of the underground hole excavator at the time of forward rotation. FIG.

FIG. 8 (a) is a cross-sectional plan view of the underground hole excavator at the time of reverse rotation.

FIG. 9A is a side view of the underground hole excavator at the time of normal rotation. FIG. 9B is a side view of the underground hole excavator at the time of reverse rotation.

FIG. 10A is a side view of the shaft at the time of normal rotation. FIG. 10B is a side view of the shaft at the time of reverse rotation.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 shaft 3 bearing 4, 5 mounting body (rotation range defining means) 6 claw 7 pin 12, 13 stator 20 rod (connecting member) 22 flange 23 block 24 connector (rotation range defining means) 25 hole 28 mover

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E21B 10/32 E21B 7/00

Claims (7)

(57) [Claims] 1. A shaft, a block mounted on the shaft, and a claw for excavating an enlarged diameter portion protruding from the shaft and inserted into a hole formed in the block. during forward rotation pull in the block, at the time of reverse rotation so as to project from the block, and the Shah
A flange attached to the shaft,
An underground hole excavator equipped with a block . 2. The block and the pawl are provided so as to be relatively rotatable, and the relative rotation allows the pawl to be pulled into the block when the shaft rotates forward and to protrude from the block when the shaft rotates reversely. The underground hole excavation device according to claim 1, wherein the underground hole is excavated. 3. The underground hole excavator according to claim 2, further comprising a rotation range defining means for defining a relative rotation range of the block with respect to the claw. 4. The claw is mounted on a bearing mounted on the shaft so as to be horizontally rotatable about a pin, and performs the pull-in / projection operation while rotating horizontally about a pin. An underground hole excavator according to any one of claims 1 to 3. 5. A shaft, a claw for protruding from the shaft and retracted when the shaft rotates in a forward direction, and protruding when the shaft is rotated in a reverse direction, and a mover displaced in conjunction with the retracting and projecting operation of the claw. And an underground hole excavating device, wherein the protrusion of the claw is detected from the displacement of the mover. 6. A plurality of claw units including the claw are provided at a pitch in a longitudinal direction of the shaft, and each of the claw units in a vertical direction is connected to each other by a connecting member interlocking with a retracting / projecting operation of the claw. The underground hole excavator according to claim 5 , wherein the movable member is connected to the connecting member, and the movable member is attached to the connecting member. 7. providing stator to the shaft, the relative position of said movable element relative to the stator, according to claim 5 also <br/> characterized in that so as to detect the protrusion of the pawl Is a drilling device for an underground hole according to 6 .