JPH04169691A - Drilling tool - Google Patents

Abstract

PURPOSE:To extend the tool life by forming, between the bottom surfaces and linear end surfaces of both blocks, recessed parts which are disposed opposite to each other when respective one-side end parts of both the blocks are protruded by a determined drilling amount from the outer surface of the device to form a circular recessed part concentric to the device in the center of the blocks. CONSTITUTION:Between the bottom surfaces and linear end surfaces 22a of both blocks 22 are formed recessed parts 22f which are disposed opposite to each other when respective one-side end parts of both the blocks 22 are protruded by Q determined drilling amount from the outer surface of a device 10 to form. a circular recessed part 25 concentric to the device 10 in the center of the blocks 22, respectively. The component of driving force generated in the recessed part 25 is worked in the radial direction so as to be against the force acting on an outer circumferential edge.

Description

[Detailed Description of the Invention] [Industrial Application Field J] The present invention relates to an excavation tool used to excavate the ground or earth in various anchor works, various drilling works, various foundation pile hole works, etc. , especially when drilling 2
This invention relates to an excavation tool that prevents the necks of the blocks from breaking and improves their durability by forming a recess in the center of each block.

"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 blocks 5a and 5b come into contact with each other, and the rotation of blocks 5a and 5b stops, and in this state, the blocks 5a and 5b stop rotating.

5a and 5b receive the rotational force of the device 2, and the bit 4
... to excavate underground, and then move forward underground using the impact force of the hammer.

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.

8b is thus blown out and separated from the tip of the excavation tool, and then moves into the excavation vibrator 9 via the ejection groove 9a provided in the device 2, and is further ejected upward from there.

"Problem to be Solved by the Invention" By the way, in the above-mentioned excavation tool, as shown in FIG. The bottom surface of the blocks 5a and 5b in the prior art is a horizontal plane, and a bit is planted there, and when drilling, this block 5a, 5b
, 5b is configured to apply impact, so when drilling,
There remained problems to be solved, such as the blocks 5a and 5b being easily shaken and easily damaged due to this vibration.

The present invention has been made in view of this background,
The purpose is to provide an excavation tool that prevents the necks of the blocks from breaking and improves their durability by forming a recess in the center of two blocks during drilling.

"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 In the excavation tool which is made eccentric from the center of the device so that the straight end surfaces of both blocks abut each other at that time, one end of each of the blocks is between the bottom surface and the straight end surface of the two blocks. The blocks are characterized in that, when both protrude from the outer peripheral surface of the device by a predetermined amount of excavation, recesses are formed that are arranged opposite to each other and form a recess that is concentric with the device at the center of the block. be.

"Function" In the present invention, each block is formed with a concave part, and when the diameter of the block is expanded, four parts are formed at the center of the block, so that the block sinks into the rock during drilling, and during excavation. Good excavation is possible with less rattling, and the components of the propulsive force generated in the four parts act in the radial direction to counteract the force acting on the outer peripheral blade.
Neck breakage can be effectively prevented 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 bit 21 implanted on the tip surface are provided with their straight end surfaces 22a facing each other, and the position of the block axis 2o is set as follows. When the device 10 rotates in the excavation direction, both 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, as shown in FIG. 1 to FIG. Recessed parts 22 that are arranged opposite to each other and form a recessed part 25 concentric with the device 10 at the center of the block 22 when protruding from the surface by a predetermined excavation amount.
The biggest feature is that f is formed respectively.

In the embodiment, the concave portion 22f is composed of a circular bottom and a tapered surface that slopes upward from the bottom, but this shape is not limited to the embodiment, and for example, The shape shown in FIGS. 4 and 5 may also be used.

Incidentally, FIG. 4 shows a configuration in which only a tapered surface is formed, and FIG. 5 shows a configuration in which the tapered surface is eliminated and a wall portion extending approximately perpendicularly from the bottom surface is formed.

Below is a detailed explanation of the main components of the excavation tool.
First, as shown in FIGS. 6 and 7, the device 10 includes a small diameter portion 10A having a spline groove 12 on the outer peripheral surface;
Large diameter portion 1 provided with insertion hole 11 into which block shaft 20 is inserted
0B, and a flange portion 13 is integrally provided on the outer circumferential surface of the large diameter portion 10B, and the flange portion 13 fits into a pull-out stopper pipe 31 provided on the inner periphery of the tip of the excavation vibrator 30. A discharge groove 14 for discharging excavated debris upward is formed.-0 In the center of the device 10, an exhaust hole 15a extending in the axial direction is formed. The exhaust hole 15a opens at the upper end of the small diameter portion of the device 10, and compressed air discharged when the hammer piston falls flows into the opening. Also, device 1o
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 b toward the distal end of the device 10 and further reaches the bottom surface of the device shaft 10 and opens.
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 device 10 in the circumferential direction 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. 7).

Furthermore, 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. 6, 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 to be offset from the center of the device 10 and point symmetrical with respect to the center of the device IO, and more specifically, as shown in FIG. The center G is set and provided so that it is located at a position of a length T that is approximately 1/4 of the distance l between the block ends from the center position C of the bottom surface of the device.

A block shaft 20 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 20.

Next, the structure of the block shaft 20 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.

Specifically, as shown in FIG.
．． It is formed to be within the range of 5 to 2.5 times,
Also, on the outer periphery of the block shaft 20,
As shown in the figure, a notch 20 into which the locking bottle 17 is inserted
a is formed. This notch 20a is the block 2
The block shaft 20 is only located at the position corresponding to the rotation angle of 2.
The outer periphery of the block shaft 22 is notched, and the basic structure is such that the notch is longer in the axial direction of the block shaft 22 than the diameter a of the locking pin 17. 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 block 22 is arranged so that its straight end faces 22a face each other and the circular arc portions 22b of the blocks 22 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 10 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 protruding from the outer circumferential surface of the device 10 is gradually attached to the proximal end in the axial direction of the device IO as it goes forward in the rotation direction. The third slope slopes towards
An inclined surface 22e is formed (see FIG. 1).

Then, the tip surface of the block 22 and the first to third
On the inclined surfaces 22c, 22d, and 22e, a plurality of pins 21 made of carbide chips are planted perpendicularly to the surfaces.

Incidentally, in the embodiment, the negative portions of these bits 21... are located near the straight end surface 22a of the block 22 and are planted along the straight end surface 22a, and the bits 22a near these straight end surfaces Of these, both blocks 22
Bits located outside the arcuate portion 22b of one block 22 at a position where one end of each of the two protrudes from the outer peripheral surface of the device by a predetermined amount of excavation (in the embodiment, the bit is located on the third inclined surface 22e). The vertex R of the bit) is an extension along the curvature of the outer surface of the block, as shown in Figure 1! It is located outward from A-B.

Note that the upper surface of the block 22 has a contact portion 22g that contacts the bottom surface of the device 10, as shown in detail in FIG.
is provided at the center of the block, and a relief portion 22h formed one step lower than the contact portion 22g is provided on the outside of the contact portion 22g. 22h, the starting end is the abutting part 22
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 vibrator 30 will be explained with reference to FIGS. 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 excavation pipe 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. 6 etc., in order to attach the block 22 to the bottom surface of the device 10, first, the block shaft 20 and the block 22 are integrated, and the straight end surface of the block 22 is inserted into the insertion hole 11 on the bottom surface of the device 10. 22a are arranged so as to face each other, and the block shaft 20 is inserted.

Next, the engaging pin 17 is inserted through the pin hole 18 of the device 10.
When the block shaft 2 is inserted and fixed, the block shaft 2 is inserted into the engagement pin 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 10.
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
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 10, 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 mutually function as stoppers to restrict further rotation of each block 7. 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. 10, 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 component force Fa of the propulsive force generated in the recess 25 acts on the peripheral blade A in the radial direction, as shown in Fig. 1. Since it acts in opposition to the force Fb, neck breakage can be effectively prevented and the tool life can be extended.

In addition, in the embodiment, some of the plurality of pits 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 located outward from the extension line A-B extending along the curvature of 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, since the bit 21 located on the extension line A-B can be operated in an outward direction, wear of the bit can be reduced and the tool life can be extended.

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 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 20 can be reduced, and the strength of the block shaft 20 can be improved.

In addition, in the embodiment, a flange portion 30a that comes into contact with the tip of the excavation vibrator 30 is provided on the outer periphery of the extraction stopper pipe 31, and the flange portion 30a and the tip of the excavation pipe 30 are welded over the entire circumference. The plate forms a notch hole 31b in the retaining vibrator 31 that extends in the axial direction and communicates with the inside and outside of the retaining pipe, and connects the retaining vibrator 31 and the excavating vibrator 30 through the notch hole 31b. Because they are welded, the pull-out stopper vibe 31 and the excavation vibe 30 can be firmly fixed together. In particular, the pull-out stopper vibe 31 is connected to the notch hole 31b that communicates with the inside and outside of the pull-out stopper pipe 31. By welding at this position, the welding is effective at this part, so there is an advantage that the retainer pipe 31 and the excavation vibe 30 can be more firmly fixed.

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.

In this way, the excavation tool can be slid within the excavation pipe 30, so that the excavation 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 m cuttings on the contact surface, and there is an effect that resistance when the block is contracted can be removed.

Further, in the embodiment, the upper surface of the block 22 is provided with a device l.
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, even when the block 22 is contracted and pulled up into the excavation pipe 30, the block 22 can be easily pulled up along the inclined surface 22j. Even if curling occurs, 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 work efficiency on site can be improved. effective.

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, each block is formed with a concave part, and four parts are formed at the center position when the diameter of the block is expanded. It has a shape that embeds itself in the rock, which prevents rattling during excavation and enables good excavation, and the component of the propulsive force generated in the recess acts in the radial direction to counteract the force acting on the outer peripheral blade. Therefore, neck breakage can be effectively prevented, the tool life can be extended, and the neck of the block can be prevented from breaking and its durability can be improved. .

[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.
The figure is a plan view showing the block in a reduced diameter state, Figure 3 is a cross-sectional view of the slock, Figures 4 and 5 are cross-sectional views shown to explain other shapes of the four parts, and Figure 6 is a cross-sectional view of the block. FIG. 7 is a half-sectional view showing the entire digging tool, FIG. 8 is a sectional view showing the device in an enlarged state, and FIG. 9 is a plan view showing the bottom of the device. Fig. 10 is a perspective view of the device and the block, Fig. 11 is a front view of the block, Fig. 12 is a cross-sectional view showing the block shaft and locking bottle engaged, and Figs. 13 and 14 are the device and excavation. 15 to 17, which are side views shown to explain the action of the abutment surface of the pipe, show an example of a conventional excavation tool, and FIG. 15 is a sectional view of the excavation tool, and FIGS. 16 and 1
FIG. 7 is a plan view showing the bottom surface of each block. G: Axis center, C: Center of device,
10...device, 11...insertion hole,
13...flange part, 14...exhaust groove, 1'5a...exhaust hole, 15b...eye...
Communication hole, 15c... Air hole, 15d Old... Notch, 16a... Circumferential groove, 16b... Communication hole, 16c... Blow hole , 17...
Locking pin, 18... Bottle hole, 20...
Block shaft, 20a/old...notch, 21...
Bit, 22...Block, 22a...
- Straight end face, 22C122d, 22e -=- slope, 22f... recessed part, 25... recessed part,
30...Drilling pipe, 31...Removal stop pipe.

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 the excavation tool which is eccentric from the center of the device, between the bottom surface and the straight end surface of the two blocks, one end of each of the blocks protrudes from the outer peripheral surface of the device by a predetermined amount of excavation. 1. An excavating tool characterized in that recesses are formed at the center of the block so as to be arranged opposite to each other and form concentric recesses with the device when the block is being drilled.