JP5017384B2 - Extended drill bit and drilling method using the same - Google Patents

Description

  The present invention relates to an extended excavation bit, and more particularly to an extended excavation bit for excavating a foundation hole having a diameter-expanded hole at the bottom and a excavation method using the same.

As an excavator for excavating a foundation hole having an enlarged diameter hole at the bottom, an expanded excavation bit that expands and reduces the diameter of the excavation bit attached to the tip of the excavation rod by, for example, reverse rotation / forward rotation of the excavation rod It is known (patent documents 1 to 3).
In addition, since the expansion claw attached to the excavation bit reduces the diameter when it is pulled out after completion of the excavation work, the expansion claw has a problem that it cannot be confirmed whether or not the expansion claw has expanded when the bottom diameter expansion hole is formed. An excavation bit that can confirm whether or not an expanded excavation has been performed by providing a shear pin that is sheared at the time of expansion and checking whether or not the shear pin is cut at the end of the work is known (Patent Document 4).
Furthermore, as an expansion confirmation method that can reliably determine that the expansion pawl has expanded to the maximum excavation diameter after the expansion excavation work, on the track where the expansion pawl swings from the closed position to the final expanded position. The detection fine material made of soft metal is held in a positional relationship that can be pressed and deformed by the expansion claw that has swung to the final expansion position, and after the expansion excavation work, the deformation of the detection fine material remaining on the excavation bit is detected. A method for confirming the expansion of the expansion claw at the maximum excavation diameter is known (Patent Document 5).

JP 2004-346586 A JP 2005-290941 A JP 2006-299526 A Japanese Patent Application Laid-Open No. 11-6281 JP 2009-275443 A

However, as a method for confirming that the expansion pawl has expanded to the maximum excavation diameter, in the method for determining whether or not the shear pin is cut, a new shear pin must be attached each time a new foundation hole is excavated. There's a problem.
Further, in the method using the detection fine material made of soft metal, there is a problem that it is difficult to detect the degree of deformation of the detection fine material.

  The present invention has been made to cope with such problems, and has an easy-to-use structure and an expanded excavation bit that can reliably confirm that an expanded hole in foundation work has been excavated at the bottom. The purpose is to provide a drilling method.

The extended excavation bit of the present invention is connected to the lower end of the excavation rod, and has an enlarged claw on the outer peripheral edge of the spiral blade that expands the diameter when the excavation rod rotates in the reverse direction and reduces the diameter when the excavation rod rotates in the forward direction. The base is pivotally supported in a direction perpendicular to the main surface of the spiral blade,
Between the base of the expansion claw and the front end of the expansion claw, an L-type confirmation pin having one end supported so as to be rotatable in the same direction as the rotation direction of the base is provided, and the other end of the L-type confirmation pin Have a pin case on the main surface of the spiral blade,
The other end of the L-shaped confirmation pin can be housed in the pin case during the forward rotation of the excavation rod at the start of excavation, and the other end of the L-shaped confirmation pin is detached from the pin case by the reverse rotation of the excavation rod. It is possible to do.

The excavation method of the present invention is an excavation method for excavating a foundation hole having a diameter-expanded hole at the bottom using the above-described expanded excavation bit of the present invention,
The other end of the L-shaped confirmation pin is housed in the pin case, and the excavation bit is lowered while the expansion pawl is reduced in diameter by the earth pressure generated by the forward rotation of the excavation rod to excavate a basic hole having a predetermined depth. A basic hole forming process,
A predetermined depth by which the diameter of the expansion claw is expanded by earth pressure due to reverse rotation of the excavation rod, and the excavation bit is lifted to expand the diameter while the other end of the L-shaped confirmation pin is detached from the pin case. A diameter expansion hole forming process for excavating the foundation hole of
The diameter of the expansion pawl is reduced by the earth pressure due to the forward rotation of the excavation rod, and the excavation bit is taken out on the ground with the other end of the L-shaped confirmation pin detached from the pin case,
The other end of the L-shaped confirmation pin is detached from the pin case, so that it is confirmed that a diameter expansion hole is formed.

  The extended excavation bit of the present invention has an L-shaped confirmation pin that is housed in the pin case at the time of forward rotation when the excavation rod starts excavation and can be detached from the pin case by reverse rotation of the excavation rod. If the L-shaped confirmation pin of the excavation bit that is sometimes pulled up is detached from the pin case, it can be easily confirmed that the base hole having the enlarged diameter hole at the bottom is formed.

  Since the excavation method of the present invention uses the above-described expanded excavation bit of the present invention, it is ensured that the enlarged diameter hole has been excavated at the bottom even if the basic hole is excavated by the conventional method without requiring a special device. I can confirm.

FIG. 1A is a view showing a diameter-reduced state of an expanded excavation bit for foundation work of the present invention, and FIG. 1B is a view showing an expanded state of the excavation bit for foundation work of the present invention. . 2 (a) and 2 (c) are plan views showing the reduced diameter state of the expanded excavation bit, and FIG. 2 (b) is a plan view showing the expanded diameter state. 3A is a view showing a base hole forming step, FIG. 3B is a view showing a forming step of an enlarged hole at the bottom of the base hole, and FIG. 3C is a view showing a step of taking out a drill bit. is there.

  An extended excavation bit for foundation work according to the present invention will be described with reference to the drawings. FIG. 1A is a diagram showing a reduced diameter state of the expanded excavation bit, and FIG. 1B is a diagram showing a diameter expanded state. 2 (a) and 2 (c) are plan views showing the reduced diameter state of the expanded excavation bit, and FIG. 2 (b) is a plan view showing the expanded diameter state.

As shown in FIG. 1 (a) and FIG. 1 (b), the extended excavation bit 1 of the present invention is connected to the lower end of a excavation rod 2 for excavating a base hole having an enlarged diameter hole at the bottom in foundation work. This is an extended excavation bit having a tip claw 3 at the bit tip.
This extended excavation bit 1 is provided with an enlarged claw 4 on the outer peripheral edge of the spiral blade 1a that expands in diameter when the excavation rod 2 rotates in the reverse direction and decreases in diameter when the excavation rod 2 rotates in the forward direction. Here, the forward rotation of the excavating rod 2 refers to the clockwise direction of the excavating rod 2 and the counterclockwise rotation refers to the plan view shown in FIGS.
The base 4a of the expansion claw 4 is pivotally supported by a shaft 6 provided in a direction perpendicular to the main surface of the spiral blade 1a. Further, the expansion claw 4 is coupled to the shaft 6 in a knuckle joint shape. When the tip 4b of the expansion claw 4 becomes substantially perpendicular to the outer periphery of the spiral blade 1a, the expansion claw 4 expands to the notch 1b of the spiral blade 1a. The base 4a of the claw 4 comes into contact, and the enlarged claw 4 does not rotate any further. When the excavation rod 2 is rotated in the reverse direction, the distal end 4b of the expansion pawl 4 is fixed at a substantially right angle with respect to the outer periphery of the spiral blade 1a, so that when the spiral blade 1a is rotated, the outer edge serving as the locus is expanded. (FIG. 2B).

The expansion excavation bit 1 of the present invention includes an L-shaped confirmation pin 5 on the expansion claw 4 that can confirm that the diameter expansion hole has been excavated at the bottom during excavation of the basic hole.
The other end 5b of the L-shaped confirmation pin 5 is kept in the pin case 7 when the excavation rod 2 is moved down by the forward rotation, and when the excavation is lifted up by the reverse rotation of the excavation rod 2 to form the enlarged hole. In this state, the pin case 7 is detached, and this normal state is maintained even when the base hole of the normal diameter is lifted by the forward rotation of the excavating rod 2. By confirming the state where the L-shaped confirmation pin 5 of the extended excavation bit 1 pulled up is detached from the pin case 7, it can be confirmed that the diameter-expanded hole is formed.

The shaft hole 4c for supporting the L-shaped confirmation pin 5 is provided between the base portion 4a of the enlarged claw and the distal end portion 4b of the enlarged claw (FIG. 2). The L-type confirmation pin 5 is supported at one end 5a so as to be rotatable in the same direction as the direction in which the base 4a of the expansion claw rotates. That is, it is supported by the shaft hole 4 c parallel to the shaft 6. The shaft hole 4c is formed substantially perpendicular to the main surface of the spiral blade 1a to which the enlarged claw 4 is attached. The other end 5b of the L-shaped confirmation pin 5 is stored in the pin case 7 at the start of cutting. The pin case 7 has an opening on the side of the expansion claw 4 and is fixed to the main surface 1a of the spiral blade. In addition, this pin case 7 can be provided in the main surface 1a of a spiral blade so that rotation is possible. In this case, the storing operation of the one end 5a of the L-shaped confirmation pin 5 is facilitated.
The L-type confirmation pin 5 is a pin having an angle of about 90 degrees, and its one end 5 a is rotatably supported by the shaft hole 4 c, and the other end 5 b serving as a free end is a length that can be inserted into the pin case 7. Have

FIG. 2A is a plan view showing a reduced diameter state of the extended excavation bit, and more particularly, a diagram showing a state at the time of normal rotation at the start of excavation of the excavation rod.
At the start of excavation, one end 5 a of the L-shaped confirmation pin is rotatably supported by a shaft hole 4 c formed in the enlarged claw 4, and the other end 5 b is accommodated in the pin case 7. When the excavation rod is rotated in the arrow direction in this state, the state shown in FIG.
FIG. 2 (b) is a plan view showing the expanded diameter state of the extended excavation bit, and particularly shows the state when the excavation rod is reversely rotated.
When the diameter of the expansion claw 4 is increased substantially perpendicularly to the outer periphery of the spiral blade 1a, the shaft hole 4c is separated from the pin case 7, so that the other end 5b of the L-shaped confirmation pin is detached from the pin case 7. The tip of the other end 5b is directed in the direction opposite to the reverse rotation direction of the excavation rod. When the excavation rod is rotated in the arrow direction in this state, the state shown in FIG.

FIG. 2 (c) is a plan view showing a reduced diameter state of the extended excavation bit, and particularly shows a state during forward rotation when the excavation rod is taken out to the ground.
The other end 5b of the L-type confirmation pin detached from the pin case 7 is supported so that the one end 5a of the L-type confirmation pin can rotate, so that the earth pressure when the excavating rod is rotated from the reverse rotation to the normal rotation is obtained. For example, the pin case 7 remains detached from the pin case 7 without being stored again. Therefore, if the L-shaped confirmation pin 5 of the excavation bit pulled up at the end of the excavation work is detached from the pin case 7, it can be easily confirmed that the base hole having the enlarged diameter hole at the bottom is formed.

An excavation method for excavating a foundation hole having an enlarged diameter hole at the bottom using the expanded excavation bit 1 will be described with reference to FIG.
In the basic hole forming step shown in FIG. 3A, the L-shaped confirmation pin 5 is housed in the pin case 7, and the expansion claw 4 is reduced in diameter by the earth pressure due to the forward rotation of the excavation rod 2, and the excavation bit 1 Is lowered to excavate a foundation hole of a predetermined depth. The state of the enlarged claw 4 at this time is the state shown in FIG.
The excavation by the tip pawl 3 is lowered extended drill bit 1 for forming a predetermined depth H, basal pores with a pore diameter D _B. During this time, the other end 5 b of the L-shaped confirmation pin 5 is kept in the pin case 7 during the lowering of the excavation due to the forward rotation of the excavation rod 2.

After the excavation to a predetermined depth H, when the excavation rod 2 is rotated in the reverse direction in the step of forming the enlarged diameter hole shown in FIG. 3B, the expansion claw 4 is expanded in diameter by the earth pressure due to the reverse rotation. The state of the enlarged claw 4 at this time is the state shown in FIG.
With the diameter of the expansion claw 4 expanded, the excavation bit 1 is raised with the other end 5b of the L-shaped confirmation pin 5 detached from the pin case 7, and the diameter expansion hole of a predetermined depth H _E and hole diameter D _E is used as a basis. Drill at the bottom of the hole. During this time, earth and sand accompanying excavation may enter the pin case 7 from which the L-type confirmation pin 5 is detached. In addition, since the tip of the other end 5b of the L-shaped confirmation pin 5 is a free end, it is considered that the direction is opposite to the rotation direction of the excavation rod 2.

After forming a diameter-expanded hole of a predetermined depth at the bottom of the base hole, in the extended excavation bit take-out step shown in FIG. With the other end 5b of the L-shaped confirmation pin 5 detached from the pin case 7, the excavation bit 1 is taken out to the ground. The state of the enlarged claw 4 at this time is the state shown in FIG.
The L-type confirmation pin 5 is inverted in the vicinity of the pin case 7 in conjunction with the enlarged claw 4 by the forward rotation of the excavating rod 2. However, earth and sand when excavating the diameter expansion hole has entered the pin case 7 in which the L-type confirmation pin 5 was stored at the start of excavation, and the inverted L-type confirmation pin 5 is in the pin case 7. The tip of the other end 5b does not face in the direction in which it can be stored. For this reason, the L-type confirmation pin 5 is pulled up together with the extended excavation bit 1 while being detached from the pin case 7.

  After being pulled up to the ground, by confirming that the L-shaped confirmation pin 5 of the extended excavation bit 1 pulled up to the ground is detached from the pin case 7 as shown in FIG. The formation of holes can be confirmed.

  Since the expansion excavation bit of the present invention has an L-shaped confirmation pin that can easily confirm that a foundation hole having a diameter expansion hole at the bottom is formed, it can be used as an expansion excavation bit for many foundation works.

DESCRIPTION OF SYMBOLS 1 Expansion drilling bit 2 Drilling rod 3 Tip nail 4 Expansion nail 5 L type confirmation pin 6 Axis 7 Pin case

Claims (2)

An extended excavation bit connected to the lower end of the excavation rod and having an enlarged claw on the outer peripheral edge of the spiral blade that expands the diameter when the excavation rod rotates in the reverse direction and reduces the diameter when the excavation rod rotates in the forward direction,
The base of the expansion claw is pivotally supported in a direction perpendicular to the main surface of the spiral blade,
Between the base of the expansion claw and the front end of the expansion claw, an L-type confirmation pin having one end supported so as to be rotatable in the same direction as the rotation direction of the base is provided, and the other end of the L-type confirmation pin A pin case that can accommodate the spiral blade on the main surface of the spiral blade,
The other end of the L-shaped confirmation pin can be stored in the pin case at the time of forward rotation of the excavation rod at the start of excavation, and the other end of the L-shaped confirmation pin is detached from the pin case by reverse rotation of the excavation rod. An extended excavation bit characterized by being able to. A drilling method for excavating a base hole having an enlarged diameter hole at the bottom using the extended excavation bit according to claim 1,
The other end of the L-shaped confirmation pin is housed in the pin case, and the excavation bit is lowered to excavate a base hole having a predetermined depth while the expansion pawl is reduced in diameter by the earth pressure due to the forward rotation of the excavation rod. A basic hole forming process,
A predetermined depth by which the diameter of the expansion claw is expanded by earth pressure due to reverse rotation of the excavation rod and the diameter of the expansion pin is increased by increasing the excavation bit in a state where the other end of the L-shaped confirmation pin is detached from the pin case. A diameter expansion hole forming process for excavating the foundation hole of
The diameter of the expansion claw is reduced by earth pressure due to the forward rotation of the excavation rod, and the excavation bit extraction step of extracting the excavation bit to the ground with the other end of the L-shaped confirmation pin detached from the pin case;
The excavation method characterized by confirming that the diameter expansion hole is formed by the other end of the L-shaped confirmation pin being detached from the pin case.

Images