JPH04169690A - Drilling tool - Google Patents

Abstract

PURPOSE:To extend the tool life by situating the top of a bit situated outside of the outer surface of one block outward of the extension line extended along the curvature of the block outer surface. CONSTITUTION:A part of a plurality of bits 21 planted on the top end surface of a block 22 is situated near the linear end surface of the block 22, and planted along the linear end surface. Of the plurality of the bits 21 near the linear end surface, the top R of the bit 21 situated outside of the outer surface of one block 22 in the position where respective one-side end parts of both blocks 22 are protruded by a determined drilling amount from the outer circumferential surface of a device 10 is situated outward of the extension line A-B extended along the curvature of the block 22 outer surface. When an impact force is added to the block 22 at the time of drilling, the force is loaded in the radially outward direction of the device 10.

Description

[Detailed Description of the Invention] "Field of Industrial Application" The present invention relates to an excavation tool used to excavate the ground or earth in various anchor construction works, various drilling works, various foundation pile hole constructions, etc. In particular, the present invention relates to a drilling tool in which the durability of the block in which the bit is embedded is improved.

"Conventional technology" Conventionally, as one of the excavation tools for excavating the ground, earth, etc.
The one described in JP-A-63-11789 is known.

As shown in FIGS. 15 to 17, this excavation tool is characterized by the impact force of the hammer (not shown) and the hammer cylinder l.
Two shaft holes 2a and 2b are formed point-symmetrically with respect to the center of the device 2 on the bottom surface of the device 2 which receives the rotational force of the device 2,
Each shaft hole 2a.

The block shafts 3a and 3b are fitted into the block shafts 2b so as to be rotatable around the shafts and cannot be removed.
Blocks 5a and 5b, each having a substantially semicircular shape with approximately the same diameter as the diameter of the device 2 and having a large number of bits 4 implanted in the tip surface, are attached to each other's straight end surfaces 6a and 6b. are provided facing each other, and the positions of the block shafts 3a and 3b are changed when the device 2 rotates in the excavation direction.

The device 2 is arranged such that one end of each of the blocks 5b protrudes from the outer peripheral surface of the device 2 by a predetermined amount of excavation, and at this time, the straight end surfaces 6a and 6b of both blocks abut each other.
It is eccentric from the center.

In the excavation tool, when the device 2 is rotated in the excavation direction X by the hammer cylinder 1, the blocks 5a,
5b rotates about the block axes 3a and 3b while receiving excavation resistance, and the block 5a.

One end of the straight end surfaces 6a, 6b of the device 2 protrudes from the outer peripheral surface of the device 2 by a predetermined amount, and the straight end surfaces 6a, 6
Parts of the blocks 5a and 5b come into contact with each other and the rotation of the blocks 5a and 5b is stopped, and in this state, the blocks 5a and 5b are connected to the device 2.
Under the rotational force of the bit 4, the bit 4 excavates underground, and the impact force of the hammer advances the underground.

At this time, the excavated earth and sand are removed through an air hole 8a provided at the bottom of the device 2, through which compressed air is discharged when the hammer piston falls inside the hammer cylinder l.

By being blown out from 8b, it is separated from the tip of the excavation tool, and then moves into the excavation pipe 9 via a discharge groove 9a provided in the device 2, and is discharged further upward from there.

"Problem to be Solved by the Invention" By the way, in the above-mentioned excavation tool, as shown in FIG. Since the earth is excavated by the hammer and the impact force of the hammer is used to advance underground, especially when the blocks 5a and 5b are protruded, the impact force of the hammer is applied to the central part of the blocks 5a and 5b, and this part There were disadvantages such as severe wear of the bit, shortening the tool life and reducing drilling efficiency.

The present invention has been made to solve the above-mentioned problems, and its purpose is to suppress the wear of the bit in the center of the block, extend the tool life, and improve excavation efficiency. The goal is to provide tools.

"Means for Solving the Problem" In order to achieve the above object, the present invention provides block shafts that are point-symmetrical to the center of the device on the bottom surface of the device that receives the impact force of the hammer and the rotational force of the hammer cylinder. The block is fitted so as to be rotatable around the shaft, and the block, which has a substantially semicircular shape with approximately the same diameter as the device and has a bit implanted in the tip surface, is attached to the tip of each block shaft in a straight shape. end surfaces facing each other, and the position of the block axis is such that when the device rotates in the excavation direction, one end of each of the blocks protrudes from the outer peripheral surface of the device by a predetermined amount of excavation, and At that time, in a drilling tool that is made eccentric from the center of the device so that the straight end faces of both blocks come into contact with each other, some of the plurality of bits planted on the tip face of the block are removed from the straight end face of the block. The bits are located nearby and planted along the straight end face, and among the bits near the straight end face, one end of each of the blocks protrudes from the outer peripheral surface of the device by a predetermined excavation amount. The apex of the bit, which is located outside the outer surface of one of the blocks at the position where the bit is located, is located outside of an extension line extending along the curvature of the outer surface of the block.

"Operation" In the present invention, some of the plurality of bits implanted on the tip end surface of the block are positioned near the straight end surface of the block and implanted along the straight end surface, and the bits are implanted along the straight end surface of the block. Among the bits near the shaped end surface, the apex of the bit located outside the outer surface of one of the blocks at a position where one end of each of the blocks protrudes from the outer peripheral surface of the device by a predetermined amount of excavation. Since it is located outward from the extension line extending along the curvature of the outer surface of the block, when an impact force is applied to the block during excavation, the force is applied outward in the radial direction of the device. This has the advantage that the force acting on the peripheral cutting edge can be borne.

Furthermore, since the bit on the extension line can be operated outward, wear on the bit can be reduced and tool life can be extended.

"Example" Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

1 to 14 show one embodiment of the present invention, and the excavation tool shown in the figures basically has the same effect as the impact force of the hammer, similar to the excavation tool shown in FIGS. 15 to 17. A block shaft 20 is fitted into the bottom surface of the device 10 which receives the rotational force of the hammer cylinder so as to be freely rotatable around the axis in a point symmetrical manner with respect to the center of the device 10, and the tip of each block shaft 20 is Blocks 22 each having a substantially semicircular shape with a diameter substantially the same as the diameter of the device 10 and having a pin (21) implanted on the tip surface are provided with their straight end surfaces 22a facing each other, and the position of the block shaft 20 is adjusted. , when the device 10 rotates in the excavation direction, both the blocks 22
The center of the device 10 is set such that one end of both protrudes from the outer peripheral surface of the device 10 by a predetermined amount of excavation, and the straight end surfaces 22a of both blocks 22 abut against each other when the diameter of the block 22 is expanded. The basic configuration is made eccentric from the center.

However, in the present invention, some of the plurality of bits 21 implanted on the tip surface of the block 22 are
The bits 21 are positioned near the straight end faces of the device 10 and planted along the straight end faces, and among the bits 21 near the straight end faces, one end of each of the blocks 22 is located from the outer surface of the device 10. The apex R of the bit 21, which is located outside the outer surface of one block at the position where it is protruded by a predetermined amount of excavation, is located outside the extension line A-B extending along the curvature of the outer surface of the block. This is the most important feature (see Figure 1).

Below is a detailed explanation of the main components of the excavation tool.
First, as shown in FIGS. 3 and 4, the device 10 has a small diameter portion 10A having a spline groove 12 on the outer peripheral surface, and a large diameter portion 10B having an insertion hole 11 into which the block shaft 2o is inserted. A flange portion 13 is integrally provided on the outer circumferential surface of the large-diameter portion 10B, and the flange portion 13 fits with a pull-out stopper pipe 31 provided on the inner periphery of the tip of the excavation pipe 30. A discharge groove 14 is formed for discharging the water upward.

An exhaust hole 15a extending in the axial direction is formed in the center of the device 10. The exhaust hole 15a opens at the upper end of the small diameter portion of the device 1o, and compressed air discharged when the hammer piston falls flows into the opening. Also, the device lO
A communication hole 15b that communicates with the tip of the exhaust hole 15a and extends radially outward is formed in the communication hole 15.
An air hole 15c extends from both ends of the device 10 toward the distal end of the device 10, and further reaches the bottom surface of the device axis lO.
is formed. The exhaust groove 1 is located at the tip of the air hole 15c between the bottom surface and the outer peripheral surface of the device.
4 and the air hole 15c are provided with cutout portions 15d that communicate with each other.

Further, a circumferential groove 16a that goes around the circumferential direction of the device IO is formed on the outer circumferential surface of the device 10 located near the flange portion 13 of the device 10, and the circumferential groove 16a is formed inside the device 10. A communication hole 16b is provided that communicates the exhaust hole 15a with the exhaust hole 15a (see FIG. 4).

Further, a blow hole 16c is formed in the communication hole 15b that communicates with the exhaust hole 15a, and the blow hole 16c reaches the upper surface of the large diameter portion 10B of the device 10 and opens. When the air hole 15c is clogged, compressed air escapes and the hammer H care has been taken to ensure that the system does not stop. Note that, as shown in FIG. 3, this blow hole 16c is located outside the hammer H and opens, and when the hammer H is lowered, the blow hole 16c is opened by the hammer H.
Care has been taken to ensure that c is not blocked.

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

A block shaft 2o is fitted into the insertion hole 11 so as to be rotatable and prevented from being removed, and the block shaft 20 is prevented from being removed, for example, when the block shaft 20 is inserted into the insertion hole 11. This is done by inserting the locking pin 17 through the pin hole 18 of the device 10, and engaging the locking pin 17 with a notch 20a formed on the outer circumference of the block shaft 2o.

Next, the structure of the block shaft 2o and the block 22 will be explained. The block shaft 20 and the block 22 are provided perpendicularly to each other, and the block shaft 20 and the block 22 may be formed integrally. It is also possible to construct them separately and connect them with bolts or the like.

More specifically, as shown in FIG. 8, the length of the block shaft 20 is 1.5 of the outer diameter of the block shaft 20.
The outer periphery of the block shaft 20 has a notch 20a into which the locking pin 17 is inserted, as shown in FIGS. 8 and 9. is formed. This notch 20a is configured such that the outer periphery of the block shaft 20 is cut out only at a position corresponding to the rotation angle of the block 22, and the axis of the block shaft 22 is smaller than the diameter a of the locking pin 17. It has a basic structure with a long cutout in the direction. In reality, the notch 20a is set to be about 1/3 of the outer diameter of the locking bottle 17, and more specifically, it is formed to have a size of about 4 to 8 mm. be.

On the other hand, each of the blocks 22 has the same shape with a standard fan shape (semicircular shape in the embodiment) at the bottom, and the radius of the fan shape is set to approximately the same value as the radius of the device 10. The blocks 22 are arranged such that their straight end faces 22a face each other, but the arcuate portions 22b of the blocks form a substantially circle as a whole.

A first inclined surface 22c is formed on the outer periphery of the distal end surface (bottom surface) of the block 22, and the first inclined surface 22c is gradually inclined toward the proximal end side in the axial direction of the device 1o as it goes outward. This first inclined surface 2 is provided on the outer periphery of 22c.
A second inclined surface 22d is formed which is inclined toward the base end side in the axial direction of the device 10 at an inclination angle different from that of the second inclined surface 22c.

Further, when the device 10 rotates in the excavation direction, the end of the straight end surface 22a of the block 22 that protrudes from the outer circumferential surface of the device 10 is gradually attached to the proximal end in the axial direction of the device 1o as it goes forward in the rotational direction. The third slope slopes towards
An inclined surface 22e is formed (see FIG. 1).

Then, the distal end surface of the pro-7ri 22 and the first to third
A plurality of bits 21 made of carbide tips are installed perpendicularly to the inclined surfaces 22c, 22d, and 22e, respectively.

Further, in the embodiment, the bottom surface (tip surface) of both blocks 22 is
and the straight end surface 22a, when one end of both blocks 22 protrudes from the outer circumferential surface of the device 10 by a predetermined amount of excavation, the device is disposed opposite to each other at the center of the block 22. 10 and a concentric recess 25
A recessed portion 22f is formed, respectively. In the embodiment, the concave portion 22f is composed of a circular bottom portion and a tapered surface that slopes upward from the bottom portion, but this shape is not limited to the embodiment. The shape shown in the figure and FIG. 12 may be used.

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

As shown in FIG. 10, on the upper surface of the block 22, a contact portion 22g that contacts the bottom surface of the device 10 is provided at the center of the block 22, and a contact portion 22g is provided on the outside of the contact portion 22g. A relief portion 22h is provided which is formed one step lower than the contact portion 22g, and further, a starting end thereof is located between the contact portion 22g and the relief portion 22h.
An inclined surface 22j is formed at the same height as g and whose terminal end is at the same height as the clearance portion 22h.

Next, the configuration of the excavation pipe 30 will be explained with reference to FIGS. 3 to 5. It is formed into a cylindrical shape large enough to insert the device 10, and its tip A removable vibrator 31 is integrally fixed to the inner periphery.

A flange portion 31a that comes into contact with the tip of the excavation vibrator 30 is provided on the outer periphery of the extraction stopper vibrator 31, and
The flange portion 31a is welded to the tip of the excavation vibrator 30 by a welding portion S over the entire circumference. Further, the non-displacement vibrator 31 has a notch hole 31b extending in the axial direction thereof and communicating with the inside and outside of the non-disposal vibrator 31.
is formed, and the retaining vibrator 31 and the excavating vibrator 30 are welded together at a welding portion S through this notch hole 31b.

Next, the operation of the excavation tool having the above configuration will be explained.

As shown in FIG. 3, etc., in order to attach the block 22 to the bottom of the device 10, the block shaft 20 and the block 22 are first integrated, and the straight end of the block 22 is inserted into the insertion hole 11 on the bottom of the device 10. 22a are arranged so as to face each other, and the block shaft 20 is inserted.

Next, the engagement bottle 17 is inserted through the bottle hole 18 of the device 10.
Insert and fix the block shaft 2 in the retaining bin 17.
0 are engaged, and the block and device are assembled, as shown in FIG.

This assembly involves inserting the block shaft 2 into the insertion hole 11 of the device IO.
0 and engage the locking pin 17, and since the two block shafts 20 can be locked with one locking pin 17, the workability can be improved. There is.

In the excavation tool as described above, when the hammer cylinder receives a driving force and is rotated in the direction of arrow X, the device 10, block shaft 20, and block 22 also rotate integrally in the same direction.

Furthermore, when the hammer piston disposed in the hammer cylinder is driven and a downward impact force is applied to the device 10, the block 22 is pushed into the ground and the bit 2 is driven by the rotational force.
1 excavates the earth and stone.

Block 2 with hammer cylinder and device 10
When the block 2 rotates in the excavation direction, the block 22 rotates around the block axis 20 due to excavation resistance, and one end of the right upper end surface of the block 22 protrudes from the outer peripheral surface of the device IO, and this portion functions as the outer peripheral blade A.

Further, when the blocks 22 rotate, the end surfaces 22a directly above each block abut each other, and these act as stoppers to restrict further rotation of each block. In this state, the block 22 receives the rotational force of the device 10 and excavates underground using the peripheral blade A and the like.

At this time, as the hammer piston falls, compressed air flows in from the exhaust hole 15a and is blown out from the air hole 15c, removing the excavated debris. Air hole 1
Since a notch 15d communicating with the discharge groove 14 is formed at the tip of the groove 5c, a portion of the compressed air flows directly as shown by the arrow in Fig. 7, assisting in the discharge of excavated debris. Debris can be removed efficiently.

In addition, in the embodiment, as shown in FIGS. 13 and 14,
When the hammer piston falls, a part of the compressed air passes through the communication hole 16b, flows into the circumferential groove 16a, and is exhausted to the outside, so that it is not applied to the lower surface (contact surface) of the flange portion 13 of the device 10. This has the advantage of preventing the intrusion of excavated debris and protecting the device contact surface.

In addition, a concave portion 22f is formed in each block 22 during excavation, and a concave portion 25 is formed at the center of each block 22 when the diameter of the block 22 is expanded, so that the block 22 sinks into the rock during drilling. Good excavation is possible with less rattling during excavation, and the force Fb of the propulsive force generated in the four parts 25 acts in the radial direction on the outer peripheral blade A, as shown in FIG. Since it works to counteract this, neck breakage can be effectively prevented and tool life can be extended.

In addition, in the embodiment, some of the plurality of bits 21 planted on the tip surface of the block 22 are located near the straight end surface of the block 22 and planted along the straight end surface, and Among the bits 21 near these straight end faces, one end of each of the blocks 22 is located outside the outer surface of one of the blocks 22 at a position where both blocks 22 protrude by a predetermined amount of excavation from the outer peripheral surface of the device. As shown in Fig. 1, the apex of the bit 21 is positioned outward from the extended line A-B extending along the outer surface of the block, so that no impact force is applied to the block 22 during excavation. In this case, there is an advantage that force can be applied in the radially outward direction of the device 10, and the force acting on the peripheral blade A can be applied. Moreover, the aforementioned extension 1! Since the bit 21 located on A-B can be operated in an outward direction, wear of the bit can be reduced, and the tool life can be extended, among other advantages.

Furthermore, when the piston in the hammer cylinder falls, the compressed air pushed out by the hammer piston is discharged through the exhaust hole 15.
a, passes through the communication hole 15b, and is blown out from the blow hole 16c. Therefore, even if the air hole 15c at the tip of the device becomes clogged due to a layer of soft mud or other factors, the compressed air will still be blown out from the blow hole 16c. Therefore, the operation of the piston does not stop, and the drilling work is not impaired, so that the work efficiency can be improved.

In addition, due to the above-mentioned excavation, the bottom surface of the device is reduced by the impact, or the length of the device becomes smaller than the original one due to rework due to damage to the impact surface. The notch 22a into which the locking pin 17 is inserted is larger than the diameter of the locking pin 17 on the block shaft 20.
Since the locking pin 17 is formed to be long in the axial direction, even if the length dimension of the device 10 is shortened, the shearing force acting on the locking pin 17 does not increase.
It has the advantage of being able to prevent shaft breakage.

Moreover, in the embodiment, the cutout portion 22a is
Since it has a notch structure in which only the zero rotation range is cut, there is an advantage that the cross-sectional defect of the block shaft 2o can be reduced, and the strength of the block shaft 20 can be improved.

In addition, in the embodiment, a flange portion 3゜3 is provided on the outer periphery of the pull-out stopper vibrator 31 to abut the tip of the excavation vibrator 30, and the flange portion 30a and the tip of the excavation pipe 3o are welded over the entire circumference. , a notch hole 31b is formed in the non-displacement vibrator 31 that extends in the axial direction thereof and communicates with the inside and outside of the non-disposal vibrator, and the non-distraction vibrator 31 and the excavation pipe 30 are inserted through the notch hole 31b. Because they are welded together, it is possible to firmly and integrally fix the pull-out stopper vibe 31 and the excavation pipe 30, and in particular, the pull-out stopper vibe 31 has a notch hole that communicates with the inside and outside of the pull-out stopper vibe 31. By welding at the position 31b, the tightening by welding is effective at this part, so there is an advantage that the vibration 31 and the excavation pipe 30 can be more firmly fixed to each other.

After the excavation is completed, the hammer cylinder is rotated in the opposite direction to the excavation direction, but at this time, each block 22
The block 22 rotates in a direction opposite to that during excavation, and as shown in FIG. 2, the arcuate portion 22b located at the outermost periphery of the block 22 is located at the same level as the bottom surface of the device 10 or inside it.

In this way, the excavating tool can be slid inside the excavating vibrator 30, so that the excavating tool can be pulled out by pulling the hammer cylinder upward.

Note that during the diameter reduction operation of the block 22 as described above, the air hole 15c on the bottom of the device is temporarily blocked by the block 22 during the diameter reduction of the block 22, but the tip of the air hole 15c is Since a notch 15d that opens on the side surface of the block is formed, compressed air can be exhausted to the outside through the notch 15d, and by blowing compressed air onto the contact surface between the device and the block, It is possible to effectively remove excavated debris on the abutting surface, and there are effects such as being able to eliminate resistance when the block is contracted.

In addition, in the embodiment, the device 1 is provided on the top surface of the block 22.
A contact portion 22g that contacts the bottom surface of the block 22 is provided at the center of the block 22, and a relief portion 2 is formed on the outside of the contact portion 22g to be one step lower than the contact portion 22g.
2h is provided between the abutting portion 22g and the relief portion 22h, and a slope whose starting end is at the same height as the abutting portion 22g and whose terminal end is at the same height as the relief portion 22h is provided. Side 2
2j is formed, so block 22 is collected f! Also when pulling up into the excavation vibrator 30, the inclined surface 22j
The block 22 can be easily pulled up along the
In addition, even if the abutting portion 22g is bulged due to the impact during excavation, the relief portion 22h is formed one step lower than the abutting portion 22g, so it will not hinder the lifting of the block 22, and the This has the effect of improving workability.

It goes without saying that the present invention is not limited to the embodiments described above, and that various changes can be made without departing from the gist of the invention.

"Effects of the Invention" As explained above, according to the present invention, some of the plurality of bits implanted on the end face of the block,
The bits are located near the straight end face of the block and planted along the straight end face, and among the bits near the straight end face, one end of each of the blocks is located at a predetermined distance from the outer peripheral surface of the device. The apex of the bit, which is located outside the outer surface of one of the blocks at the position where it is protruded by the amount of excavation, is located outside of the extension line extending along the curvature of the outer surface of the block, so during excavation, When an impact force is applied to the block, there is an advantage that the force can be applied in a radially outward direction of the device, and the force acting on the peripheral blade can be borne.

Moreover, since the bit on the extension line can be operated outward, wear of the bit can be reduced and the tool life can be extended, among other advantages.

As a result of the above, it is possible to provide an excavation tool that can suppress wear of the bit in the center of the block, prolong the tool life, and improve excavation efficiency.

[Brief explanation of the drawing]

1 to 14 show an embodiment of the present invention, in which FIG. 1 is a plan view showing the block with its diameter enlarged, and FIG.
Figure 3 is a plan view showing the block in a reduced diameter state, Figure 3 is a sectional view showing the entire excavation tool, Figure 4 is a half sectional view showing the entire excavation tool, and Figure 5 is an enlarged view of the device. 6 is a plan view showing the bottom of the device, FIG. 7 is a perspective view of the device and block, FIG. 8 is a front view of the block, and FIG. 9 is a diagram showing the state of engagement between the block shaft and the locking pin. 10 is a sectional view of the block, FIG. 11 and 1
2 is a sectional view shown to explain other shapes of the recess, FIGS. 13 and 14 are side views shown to explain the action of the contact surface of the device and the excavation pipe, and FIG.
Figures 1 to 17 show an example of a conventional excavation tool.
FIG. 5 is a sectional view of the excavation tool, and FIGS. 16 and 17 are plan views showing the bottom surface of the block. G: Axial center, C: Center of device,
lO...device, 11...insertion hole,
13... Flange portion, 14... Exhaust groove, 15a... Exhaust hole, 15b... Old... Communication hole,
15c...Air hole, 15d...Notch, 16a...Peripheral groove, 16b...Communication hole, 16c...Blow hole, 17... Locking bottle, 18... Bottle hole, 20... Block shaft, 20a... Notch, 21...
Bit, 22...Block, 22a... Group/straight end surface, 22c, 22d, 22e... Inclined surface,
22f... Concave portion, 25... Concave portion.

Claims (1)

[Scope of Claims] Each block is fitted into the bottom surface of a device that receives the impact force of the hammer and the rotational force of the hammer cylinder so as to be freely rotatable around a block axis, point symmetrical with respect to the center of the device. At the tip of the shaft, a block having a substantially semicircular shape with approximately the same diameter as the device and having a bit implanted in the tip surface is provided with each straight end surface facing each other, and the position of the block shaft is adjusted. , when the device rotates in the excavation direction, one end of each of the blocks protrudes from the outer peripheral surface of the device by a predetermined excavation amount, and at this time, the straight end surfaces of both blocks abut each other. In a drilling tool that is eccentric from the center of the device, some of the plurality of bits planted on the tip face of the block are located near the straight end face of the block and planted along the straight end face. At the same time, among the bits near the straight end faces, one end of each of the two blocks protrudes from the outer peripheral surface of the device by a predetermined amount of excavation, and is located outside the outer surface of one of the blocks. A drilling tool characterized in that the apex of the bit is located outward from an extension line extending along the curvature of the outer surface of the block.