JP2830454B2 - Drilling tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a drilling tool used for excavating the ground and soil in various anchor works, various drilling works, various foundation pile hole works, and the like. More particularly, the present invention relates to a drilling tool that facilitates lifting of a block provided at a device tip.

2. Description of the Related Art Conventionally, as one of excavating tools for excavating ground, earth and sand, etc., the one described in JP-A-63-11789 is known.

This drilling tool, as shown in FIGS.
Two shaft holes 2a and 2b are formed on the bottom surface of the device 2 which receives the impact force of a hammer (not shown) and the rotational force of the hammer cylinder 1 in a point-symmetric manner with respect to the center of the device 2. The block shafts 3a, 3b are fitted into the holes 2a, 2b in such a manner that the block shafts 3a, 3b are rotatable around the axes and are prevented from coming off.
The blocks 5a, 5b each having a substantially semicircular shape having substantially the same diameter as that of the device 2 and having a large number of bits 4 planted on the front end faces the straight end faces 6a, 6b of each other. Let it be provided,
The position of the block shafts 3a, 3b, when the device 2 rotates in the excavation direction, one end of each of the two blocks 5a, 5b both project from the outer peripheral surface of the device 2 by a predetermined excavation amount, At that time, the straight end faces 6a, 6
b are eccentric from the center of the device 2 so that they contact each other.

In the excavating tool, when the device 2 is rotated in the excavating direction X by the hammer cylinder 1, the blocks 5a, 5
b rotates around the block shafts 3a, 3b while receiving the excavation resistance, and one end of the straight end faces 6a, 6b of the blocks 5a, 5b protrudes from the outer peripheral surface of the device 2 by a predetermined amount, and the straight end face 6a , 6b abut against each other to stop the rotation of the blocks 5a, 5b. In this state, the blocks 5a, 5b receive the rotational force of the device 2 and excavate underground with the bits 4. Go underground by the impact of the hammer.

At this time, the excavated earth and sand are separated from the tip of the excavation tool by compressed air expelled when the hammer piston falls in the hammer cylinder 1 is blown out from the air holes 8a and 8b provided on the bottom surface of the device 2. After that, it moves into the excavation pipe 9 via the discharge groove 9a provided in the device 2, and is discharged further upward therefrom.

[Problem to be Solved by the Invention] By the way, in the above-mentioned excavation tool, after the drilling is completed, the diameter of the blocks 5a and 5b is reduced to a size substantially equal to the diameter of the device, and the inside of the excavation pipe 9 for each device is pulled up. However, the upper surfaces of the blocks 5a and 5b may be deformed in order to be hit by the device 1 at the time of drilling, and the blocks 5a and 5b Was sometimes unable to be pulled up by reducing its diameter.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a drilling tool that can easily raise a block by reducing the diameter of the block after completion of drilling.

"Means for Solving the Problems" To achieve this object, the present invention provides a device mounted on the tip of a hammer cylinder and receiving the rotational force of the hammer cylinder and the impact force of the hammer, and a drilling pipe for inserting the device. A retaining pipe which is fixed in a state inserted into the inner periphery of the tip of the excavation pipe and which prevents the device from falling off, and blocks on the bottom surface of the device in point symmetry with respect to the center of the device. The shaft is rotatably fitted around the shaft, and a block having a bit planted on the front end surface is provided at the front end of each block shaft so that each end surface (straight end surface) faces each other. Position is eccentric from the center of the device,
When the device is rotated in the excavation direction, the end faces of the blocks are brought into contact with each other, and each end of the plurality of blocks protrudes from the outer peripheral surface of the device by a predetermined excavation amount, and each block is expanded in diameter. In the excavating tool, a contact portion that contacts the bottom surface of the device is provided on the upper surface of the block at the center of the block,
A relief margin formed one step lower than the contact part is provided outside the contact part, and a starting end between the contact part and the relief margin has the same height as the contact part. And a slanted surface having the same height as the escape margin is formed at the end.

[Operation] In the present invention, a contact portion that contacts the bottom surface of the device is provided on the top surface of the block at the center of the block, and is formed one step lower than the contact portion on the outside of the contact portion. A relief margin is provided, and between the contact portion and the relief margin, an inclined surface having a start end portion at the same height as the contact portion and an end portion having the same height as the relief margin portion is provided. Because it is formed, when the block is contracted and pulled up into the drilling pipe, the block can be easily pulled up along the inclined surface, so the block can be contracted easily and it is easy to enter the drilling pipe In addition, even if the contact part is bent due to the impact of excavation, the relief part is formed one step lower than the contact part, so that the lifting of the block is not disturbed, and the work on site Can be improved .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 14 show an embodiment of the present invention, and the excavating tool shown in FIGS.
As in the case of the excavating tool shown in FIG. 17, the block axes are respectively point-symmetrically arranged with respect to the center of the device 10 on the bottom surface of the device 10 receiving the impact force of the hammer and the rotational force of the hammer cylinder.
20 is rotatably fitted around the axis, and each block axis
A block having a substantially semicircular shape having a diameter substantially equal to the diameter of the device 10 and a bit 21 implanted on the distal end surface at the distal end of the device 20.
22 are provided with their straight end faces 22a facing each other, and the position of the block shaft 20 is adjusted such that when the device 10 rotates in the excavation direction, one end of each of the two blocks 22 is the outer periphery of the device 10 together. Projecting from the surface by a predetermined excavation amount,
In addition, the basic configuration is such that the straight end faces 22a of the blocks 22 are eccentric from the center of the device 10 so that the straight end faces 22a of the blocks 22 come into contact with each other when the block 22 is expanded in diameter.

However, in the present invention, a contact portion 22g that contacts the bottom surface of the device 10 is provided on the upper surface of the block 22 at the center of the block 22, and one step lower than the contact portion 22g outside the contact portion 22g. A relief portion 22h is formed at a lower height, and furthermore, a start end between the contact portion 22g and the relief portion 22h is the same height as the contact portion 22g, and a terminal portion is the same as the relief portion 22h. The greatest feature is that an inclined surface 22j having the same height is formed (see FIG. 11).

Hereinafter, the main members of the drilling tool will be described in detail. First, as shown in FIGS. 1 to 3, the device 10 includes a small-diameter portion 10A having a spline groove 12 on the outer peripheral surface,
A large diameter portion 10B having an insertion hole 11 into which the block shaft 20 is inserted is mainly constituted, and a retaining pipe 31 provided on the inner periphery of the tip of the excavation pipe 30 is provided on the outer peripheral surface of the large diameter portion 10B. Are integrally formed with each other, and a discharge groove 14 for discharging drilling chips upward is formed.

An exhaust hole 15a extending in the axial direction is formed at the center of the device 10. This exhaust hole 15a is a device
An opening is formed at the upper end of the small-diameter portion of 10, and compressed air discharged when the hammer piston falls through the opening flows into the opening. The device 10 also has an exhaust hole.
A communication hole 15b communicating with the tip of 15a and extending outward in the radial direction.
Are formed, and the device 1 is inserted from both ends of the communication hole 15b.
An air hole 15c is formed extending toward the front end of the device shaft 10 and further reaching the bottom surface of the device shaft 10 and opening. A notch 15d is provided between the bottom of the device and the outer peripheral surface of the air hole 15c and communicates with the discharge groove 14 and the air hole 15c.

On the outer peripheral surface of the device 10 located in the vicinity of the flange portion 13 of the device 10, a peripheral groove 16a is formed so as to make a circuit in the circumferential direction of the device 10, and inside the device 10, the peripheral groove 16a is formed. Communication hole that communicates with the exhaust hole 15a
16b is provided (see FIG. 2).

Further, a blow hole 16c reaching the upper surface of the large diameter portion 10B of the device 10 and opening the communication hole 15b communicating with the exhaust hole 15a.
Is formed so that when the air hole 15c is clogged, the compressed air escapes and the hammer H does not stop. The blow hole 16C is located outside the hammer H and is open as shown in FIG. 3, so that the blow hole 16c is not closed by the hammer H when the hammer H is lowered. Have been.

The insertion hole 11 is formed so as to be shifted from the center of the device 10 and to be point-symmetric with respect to the center of the device 10. More specifically, as shown in FIG. The center G is set and provided so as to be at a position of a length T which is shifted from the center position C of the device bottom surface by about 1/4 of the distance 1 between the block ends.

A block shaft 20 is inserted into the insertion hole 11 in a rotatable and locked manner.
For example, when the block shaft 20 is fitted in the insertion hole 11, the locking pin 17 is inserted from the pin hole 18 of the device 10, and the locking pin 17 is formed on the outer peripheral portion of the block shaft 20. This is performed by engaging the notch 20a.

Next, the configuration of the block shaft 20 and the block shaft 22 will be described.The block shaft 20 and the block shaft 22 are provided orthogonal to each other, and the block shaft 20 and the block 22 may be formed integrally. Alternatively, they may be formed separately and connected by bolts or the like.

More specifically, the length L of the block shaft 20 is 1.5 to 2.5 times the outer diameter D of the block shaft 20, as shown in FIG.
A notch 20a into which the locking pin 17 is inserted is formed on the outer periphery of the block shaft 20 as shown in FIGS. 6 and 7. I have. The notch 20a has a configuration in which the outer periphery of the block shaft 20 is cut out only at a position corresponding to the angle at which the block 22 rotates.
It has a basic structure that is long and notched in 22 axial directions.
In practice, the notch 20a is set to be about 1/3 of the outer diameter of the locking pin 17, more specifically, 4 to 8 mm
It is formed so as to be about the same size.

On the other hand, each of the blocks 22 has the same shape formed in a substantially fan shape (semicircular shape in the embodiment) when viewed from the bottom, and the radius of the fan shape is set to substantially the same value as the radius of the device 10.
The blocks 22 are arranged such that the straight end faces 22a face each other and the arc portions 22b of the blocks form a substantially circular shape as a whole.

On the outer peripheral portion of the distal end surface (bottom surface) of the block 22, there are formed first inclined surfaces 22c which gradually incline toward the base end in the axial direction of the device 10 toward the outside, and these first inclined surfaces are formed. On the outer peripheral portion of the second inclined surface 22c, a second inclined surface inclined toward the axially proximal end side of the device 10 at a different inclination angle from the first inclined surface 22c.
Inclined surface 22d is formed.

Further, when the device 10 rotates in the excavation direction, the straight end surface 22 of the block 22 protruding from the outer peripheral surface of the device 10
At the end of a, a third inclined surface that is gradually inclined toward the base end in the axial direction of the device 10 as it goes forward in the rotational direction.
22e are formed (see FIG. 8).

Then, the tip end face of the block 22 and the first to third
A plurality of bits 21 made of a carbide tip are implanted perpendicularly to the surfaces of the inclined surfaces 22c, 22d, and 22e.

By the way, in the embodiment, a part of these bits 21 is located near the straight end face 22a of the block 22 and
2a, among the bits 21... In the vicinity of the straight end faces, at a position where one end of each of the two blocks 22 projects by a predetermined excavation amount from the outer peripheral face of the device. Bits located outside the arc portion 22b of one of the blocks 22 (the third inclined surface 22 in the embodiment)
As shown in FIG. 8, the vertex R of the upper bit (e) is located outside the extension line AB extending along the curvature of the outer surface of the block.

In the embodiment, the bottom surfaces (tip surfaces) of the blocks 22 are used.
When one end of each of the two blocks 22 is protruded by a predetermined excavation amount from the outer peripheral surface of the device 10, the two devices are disposed so as to face each other and the device is located at the center of the block 22. Concave portions 22f which form concentric concave portions 25 with the respective portions 10 are formed. This recess 22f
In the embodiment, a circular bottom portion and a tapered surface inclined as going upward from the bottom portion are formed. However, this shape is not limited to the embodiment, and is, for example, shown in FIGS. 11 and 12. The shape shown may be used.

FIG. 11 shows a configuration in which only the tapered surface is formed, and FIG. 12 shows a configuration in which the tapered surface is eliminated and a wall portion extending substantially perpendicularly from the bottom surface is formed.

Next, a supplementary description of the configuration of the excavation pipe 30 will be given with reference to FIGS. 1 to 3, which is formed in a cylindrical shape large enough to insert the device 10 and has a tip. A retaining pipe 31 is integrally fixed to the inner periphery.

A flange portion 31a is provided on the outer periphery of the retaining pipe 31 so as to abut against the tip of the drilling pipe 30, and the flange portion 31a is welded to the tip of the drilling pipe 30 by a weld S over the entire circumference. . Further, the drilling pipe 30 has an axially extending drilling pipe.
Notch holes 30a communicating with the inside and outside of 30 are formed,
The retaining pipe 31 and the drilling pipe 3 are inserted through the cutout holes 30a.
0 are integrally welded by the welded portion S.

 Next, the operation of the excavating tool having the above configuration will be described.

As shown in FIG. 1 and the like, in order to mount the block 22 on the bottom surface of the device 10, first, the block shaft 20 and the block 22 are mounted.
Are integrated, the block shaft 20 is inserted into the insertion hole 11 on the bottom surface of the device 10 such that the straight end faces 22a of the block 22 face each other.

Next, if the engaging pin 17 is inserted and fixed through the pin hole 18 of the device 10, the block shaft 20 is engaged with the engaging pin 17, and as shown in FIG. It will be in the assembled state.

This assembling is a simple operation of inserting the block shaft 20 into the insertion hole 11 of the device 10 and engaging the engaging pin 17, and locking the two block shafts 20 by one engaging pin 17. Therefore, there is an effect that the workability can be improved.

In the above-mentioned excavating tool, when the hammer cylinder receives the driving force and is rotated in the direction of arrow X, the device 10, the block shaft 20 and the block 22 are also integrally rotated in the same direction.

Further, when the hammer piston arranged in the hammer cylinder is driven to apply a downward impact force to the device 10, the block 22 pushes into the ground and the bit 21 excavates the debris by the rotational force.

Block 22 with hammer cylinder and device 10
When is rotated in the excavation direction, the block 22 rotates around the block shaft 20 due to the excavation resistance, and one end of the upper end surface of the block 22 protrudes from the outer peripheral surface of the device 10, and this portion functions as the outer peripheral blade A.

Further, when the blocks 22 rotate, the straight end faces 22a of the blocks abut against each other, which function as stoppers to restrict further rotation of the blocks. In this state, the block 22 receives the rotational force of the device 10 and excavates underground by the outer peripheral blade A or the like.

At this time, when the hammer piston falls, the compressed air flows in from the exhaust hole 15a and is blown out from the air hole 15c, thereby removing excavated swarf. Since a notch 15d communicating with the discharge groove 14 is formed at the tip of the air hole 15c, a part of the compressed air flows directly as shown by the arrow in FIG. Excavated debris can be efficiently removed.

In the embodiment, as shown in FIGS. 13 and 14, when the hammer piston falls, a part of the compressed air,
Since the gas flows into the circumferential groove 16a through the communication hole 16b and is exhausted to the outside, it is possible to prevent excavation debris from entering the lower surface (contact surface) of the flange portion 13 of the device 10 and protect the device contact surface. There are advantages that can be.

When excavating, each block 22 has a recess
22f is formed, and the concave portion 25 is formed at the center position of the block 22 when the diameter of the block 22 is expanded, so that the block 22 is in a form that the rock is not easily inserted into the rock when drilling, and it is possible to perform a good excavation without rattling during excavation. At the same time, the component force Fa of the propulsion force generated in the recess 25 acts in the radial direction to act against the force Fb acting on the outer peripheral blade A as shown in FIG.
The neck break can be effectively prevented and the tool life can be extended.

In the embodiment, a part of the plurality of bits 21 implanted on the distal end face of the block 22 is located near the straight end face of the block 22 and implanted along the straight end face. Of the bits 21 in the vicinity of the straight end face, one end of each of the two blocks 22 is located outside the outer face of one block 22 at a position where both ends protrude from the outer peripheral face of the device by a predetermined excavation amount. As shown in FIG. 8, the apex of the bit 21 was located outside the extension line AB extending along the curvature of the outer surface of the block, so that an impact force was applied to the block 22 during excavation. In case,
There is an advantage that a force can be applied in a radially outward direction of the device 10, and a force acting on the outer peripheral blade A can be applied. In addition, since the bit 21 on the extension line AB can be made to act outward, there is an advantage that the wear of the bit can be reduced and the tool life can be extended.

Further, when the piston in the hammer cylinder falls, the compressed air pushed out by the hammer piston is discharged to the exhaust hole 15.
a, and is blown out from the blow hole 16c through the communication hole 15b.Thus, even if the air hole 15c at the tip of the device becomes clogged by an ooze layer or other factors, the compressed air is blown out from the blow hole 16c. Therefore, the operation of the piston does not stop, the drilling operation is not impaired, and the operation efficiency can be improved.

In addition, due to the excavation as described above, the bottom surface of the device is reduced due to the impact, or the length dimension of the device is smaller than the original length due to rework due to damage to the impact surface. The notch 20a into which the locking pin 17 is inserted is formed longer in the axial direction of the block shaft 20 than the diameter of the locking pin 17, so that even when the length of the device 10 is reduced, the locking pin There is an advantage that the shear force acting on the pin 17 is not increased, and the shaft of the locking pin 17 can be prevented from being broken.

Moreover, in the embodiment, the notch 20a is
Due to the notch structure in which only the rotation range is cut off, there is also an advantage that the sectional loss of the block shaft 20 can be reduced, and the strength of the block shaft 20 can be improved.

In the embodiment, a flange portion 31a is provided on the outer periphery of the retaining pipe 31 so as to be in contact with the tip of the excavation pipe 30, and the flange portion 31a and the tip of the excavation pipe 30 are welded over the entire circumference. Because the pipe 30 has a cutout hole 30a extending in the axial direction thereof and communicating with the inside and outside of the drilling pipe 30, the retaining pipe 31 and the drilling pipe 30 are welded through the cutout hole 30a. ,
The retaining pipe 31 and the excavating pipe 30 can be firmly and integrally fixed. In particular, the retaining pipe 30 is welded at a position of a cutout hole 30a communicating with the inside and the outside of the excavating pipe 30, so that this portion is formed. As a result, a fastening effect by welding is generated, so that there is an advantage that the retaining pipe 31 and the excavation pipe 30 can be more firmly fixed.

After completion of the excavation, the hammer cylinder is rotated in the direction opposite to the excavation direction.
Rotates in the direction opposite to the direction of the excavation, and as shown in FIG.
It is arranged equal to or below the bottom of 0.

By doing so, the inside of the excavation pipe 30 can be slid, so that the excavation tool can be pulled out by pulling the hammer cylinder upward.

When the diameter of the block 22 is reduced as described above, the air hole 15c on the bottom surface of the device is temporarily closed by the block 22 while the diameter of the block 22 is reduced. Since the cutout 15d that opens to the side surface of the device is formed, compressed air can be exhausted to the outside through the cutout 15d, and by blowing compressed air to the contact surface between the device and the block, Excavation debris on the contact surface can be effectively removed, and the resistance at the time of block shrinkage can be removed.

In the embodiment, the device 10 is provided on the upper surface of the block 22.
A contact portion 22g contacting the bottom surface of the block 22 is provided at the center of the block 22, and a relief portion 22h formed one step lower than the contact portion 22g is provided outside the contact portion 22g. An inclined surface 22j is formed between the portion 22g and the relief portion 22h, the starting portion having the same height as the contact portion 22g and the terminal portion having the same height as the relief portion 22h. For,
When the block 22 is contracted and pulled into the excavation pipe 30, the block can be easily pulled up along the inclined surface, so that the block can be contracted easily,
It is easy to enter the excavation pipe, and even if the contact part 22g is turned up by the impact at the time of excavation, the relief part 22h is formed one step lower than the contact part 22g. There is an effect that workability on site can be improved without hindrance.

It is needless to say that the present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the invention.

[Effects of the Invention] As described above, according to the present invention, a contact portion that contacts the bottom surface of the device is provided at the center of the block on the top surface of the block, and outside the contact portion. A relief margin formed one step lower than the contact part is provided, and furthermore, between the contact part and the relief margin part, the start end is at the same height as the contact part and the terminal part is the relief margin part. Since the inclined surface with the same height is formed, the block can be easily pulled up along the inclined surface even when the block is contracted and pulled up into the drilling pipe, so that the block can be easily contracted. Can easily enter the drill pipe,
In addition, even if the contact part is bent due to the impact during excavation, the relief part is formed one step lower than the contact part, so that the lifting of the block is not hindered, and the workability at the site Is improved.

[Brief description of the drawings]

1 to 14 show one embodiment of the present invention.
1 is a cross-sectional view showing the entire excavation tool, FIG. 2 is a half cross-sectional view showing the entire excavation tool, FIG. 3 is a cross-sectional view showing an enlarged state of the device, and FIG. 4 is a bottom view of the device. FIG. 5 is a perspective view of the device and the block, FIG. 6 is a front view of the block, FIG. 7 is a sectional view showing an engagement state of the block shaft and the locking pin, and FIG. FIG. 9 is a plan view showing a state where the diameter of the block is reduced, FIG. 10 is a cross-sectional view of the block, and FIGS. 11 and 12 are diagrams for explaining other shapes of the concave portions, respectively. 13 and 14 are side views shown to explain the operation of the contact surface between the device and the drilling pipe, and FIGS.
FIG. 17 shows an example of a conventional excavating tool, FIG. 15 is a sectional view of the excavating tool, and FIGS. 16 and 17 are plan views each showing a bottom surface of the block. G: axis, C: center of device, 10: device,
11 Insert hole, 13 Flange, 14 Discharge groove, 15a
…… Exhaust hole, 15b …… Communication hole, 15c …… Air hole, 15d ……
Notch, 16a ... circumferential groove, 16b ... communicating hole, 16c ... blow hole, 17 ... locking pin, 18 ... pin hole, 20 ... block shaft, 20a ... notch, 21 ... bit , 22 …… block, 2
2a: straight end face, 22c, 22d, 22e ... inclined surface, 22f ... concave part, 25 ... concave part, 30 ... drilling pipe.

Claims (1)

(57) [Claims] 1. A device mounted on the tip of a hammer cylinder and receiving the rotational force of the hammer cylinder and the impact force of the hammer, a drilling pipe for inserting the device, and a device inserted into the inner periphery of the tip of the drilling pipe. A retaining pipe that is fixed and retains the device, and is fitted into the bottom surface of the device so as to be rotatable about a plurality of block axes around a plurality of block axes in point symmetry with respect to the center of the device. At the tip of the block shaft, a block in which a bit is implanted on the tip surface is provided with the respective end surfaces facing each other, and the position of the block shaft is eccentric from the center of the device, and the device is moved in the excavation direction. When rotated, the end faces of the blocks are brought into contact with each other, and each end of the plurality of blocks protrudes from the outer peripheral surface of the device by a predetermined excavation amount together with each end. In a drilling tool having a block whose diameter is enlarged, a contact portion for contacting the bottom surface of the device is provided on the upper surface of the block at the center of the block, and a contact portion is provided outside the contact portion. An escape margin formed one step lower than the contact part is provided, and between the contact part and the relief margin part, the starting end is the same height as the contact part and the end part is the same as the relief margin part. An excavating tool characterized in that an inclined surface having a height equal to the height is formed.