JP2002295158A - Rock hole drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rock hole drill which has a novel structure and drills a large-diameter hole in the ground including rock masses by using a small- diameter button bit and a small driving motor. SOLUTION: The rock hole drill includes a cylindrical inner casing 22, and a boring drill 24 of a pneumatically driving type equipped with the button bit 30 is rigidly inserted into the inner casing. Further, the inner casing 22 has an excavating blade 26 fixed to a peripheral surface thereof, and the inner casing 22 is rigidly sheathed with an outer casing 28 having face claws 40 fixed to a lower peripheral edge thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drill for drilling a hole in a ground (including a bedrock) at the time of a pillar work or the like.
The present invention relates to a drill having a novel structure, which can easily and quickly drill a hole in a hard rock or the like.

[0002]

2. Description of the Related Art Conventionally, as a device used for drilling a hole such as a hole for a pillar, a pile, or an investigation on a ground including a rock, etc., (a) a screw is spirally formed on an outer peripheral surface of a rod. A rock auger drilling drill that drills by turning and excavating the rod by providing a drilling claw at the tip (lower) end of the screw, and (b) forming a hollow rod Compressed air is sent into the inside of the casing by an air compressor, and the reciprocating driving force generated by the internal piston is transmitted to the drilling head (button bit) to blow and crush the ground to create a pneumatic pressure 2. Description of the Related Art A hitting type drill (such as a down-the-hole hammer) is known.

[0003] However, in general, when drilling a large hole, a rock auger-type drilling drill causes an excessive drilling reaction force on a drilling claw when the screw is rotated at high speed to perform drilling work. Excavation work was performed by rotating the screw at low speed, and the drilling tended to be slow and did not proceed. In addition, when the excavation claw hits a hard bedrock layer, the toe is caught in the bedrock and cannot move. Was. On the other hand, with a pneumatic impact drill, drilling can be performed at a high speed for drilling a hard rock layer, etc., but in general, the mechanism of the drill itself is complicated. There is a problem that the apparatus cost increases exponentially with respect to the size of the hole.

Therefore, the applicant of the present application has previously published Utility Model No. 30
Japanese Patent Application Publication No. 04848 proposes a composite drilling apparatus in which a drilling blade is spirally wound and fixed to an outer peripheral wall (casing) of a pneumatic impact drilling drill. In such a device, hard rock is crushed and excavated by a button bit of a drilling drill to drill a hole, and the rock around the drilled hole is scraped and expanded by a drilling blade provided at a lower edge of a drilling blade. This makes it possible to drill a large-diameter hole using a small-diameter button bit, and to drill a large-diameter hole at low cost.

[0005] However, the present inventor has conducted experiments and made further studies. As a result, in such a drilling device according to the prior application, although it depends on the properties of the ground to be drilled, the outer diameter of the drilling blade may be smaller than that of the drilling blade. If the outer diameter of the button bit is too small, the cutting edge of the excavation claw will be caught on the rock and will not rotate, resulting in the necessity of a large drive motor or the use of a relatively large diameter button bit. It became clear that there were cases where it was necessary. If such a large motor or a large-diameter button bit is used, an increase in the cost of the apparatus is inevitable, and there is still room for improvement in this point.

[0006]

Here, the present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to use a small-diameter button bit and a small-sized drive motor to form a bedrock. It is an object of the present invention to provide a lock hole drill having a novel structure capable of drilling a large-diameter hole in a ground including the same.

[0007]

An embodiment of the present invention which has been made to solve such a problem will be described below. The components employed in each of the embodiments described below can be employed in any combination as possible. In addition, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or based on the invention ideas that can be understood by those skilled in the art from the descriptions. It should be understood that it is recognized on the basis of.

That is, the first aspect of the present invention relating to a lock hole drill is characterized by: (a) a cylindrical inner casing suspended and supported on a center axis of a drilling;
(B) a pneumatic percussion drilling drill that drills a button bit protruding from the lower end of the inner casing by repeatedly projecting it with compressed air, and (c) projecting on the outer peripheral surface of the inner casing. (D) a cylindrical outer casing spaced apart from the outer peripheral side of a lower portion of the inner casing, and (e) the outer casing. And a plurality of face claws, which are fixed to a peripheral edge of a lower end of the hole and are positioned on a circumference around a central axis of the hole.

In the lock hole drill having such a structure according to this aspect, first, the button bit of the hole drill is excavated in the ground at the center of the hole by impact operation by compressed air. Subsequently, the rock around the hole drilled by the button bit is drilled in an annular shape at a position radially outwardly separated from the hole by rotating the face claw of the outer casing. . Then, the ground between the circular hole formed by the button bit and the annular hole formed by the face claw is scraped off by the lower end of the excavating blade. In addition, the discharge ground generated due to the drilling by the button bit, face claw, and lower end of the excavating blade is carried out of the drilling hole to the outside by the transport action associated with the rotation of the excavating blade. Holes are formed.

Thus, in the lock hole drill according to the present invention, the small diameter center hole located at the center of the target hole is formed by the hole drilling by the button bit of the hole drill and the drilling by the face claw of the outer casing. And a large-diameter annular hole located at the outer peripheral edge of the target hole. Finally, the flat donut-shaped soil mass left between the center hole and the large-diameter annular hole is drilled by removing and excavating the earth with a drilling blade. Since the outer peripheral portion is cut off from the surrounding ground, it has become possible to efficiently drill a hard ground using a motor with a small output.

According to a second aspect of the present invention, there is provided a lock hole drill having a structure according to the first aspect,
The outer casing is fixed to the excavating blade, and the outer casing and the excavating blade are configured to be integrally rotated in the same circumferential direction around the drilling center axis. . In this aspect, since the outer casing and the excavating blade can be simultaneously driven to rotate, the transmission mechanism of the driving force to the outer casing and the excavating blade is simplified, and the transmission efficiency of the driving force is also improved. obtain.

According to a third aspect of the present invention, in a lock hole drill having a structure according to the second aspect, an inner peripheral edge portion of the drilling blade is fixed in close contact with the inner casing. In addition, the outer peripheral edge of the excavating blade is fixed to the outer casing in a close state. In such an embodiment, the inner casing, the digging blade and the outer casing are:
Since they are fixed to each other, the strength of each part can be advantageously secured. In addition, since the excavating blade is fixed in close contact with both the inner casing and the outer casing, when excavated soil or the like is placed on the excavating blade and discharged to the outside of the hole, the excavated soil or the like from the excavating blade may be removed. Dropping is prevented by the inner and outer casings, and the earth discharging efficiency can be improved.

According to a fourth aspect of the present invention, there is provided a rock hole drill having a structure according to any one of the first to third aspects, wherein a plurality of earth discharging windows are provided through the outer casing. Is characterized. In such an embodiment, air can be directly blown into the region between the inner and outer casings through the window for discharging the earth, so that, for example, the drilling blade is sent above the hole when drilling. It is easy to remove the soil that was clogged between the inner and outer casings when the lock hole drill was pulled out from the hole after drilling was completed, by applying vibration to the outer casing as necessary. And it can be discharged quickly.

According to a fifth aspect of the present invention, there is provided a rock hole drill having a structure according to any one of the first to fourth aspects, wherein a plurality of excavating claws are projected from a lower end edge of the excavating blade. And at the same time, the toes of the excavating claws are arranged so as to be gradually positioned lower on the center axis of the drilling hole from the inner peripheral side to the outer peripheral side at the lower end edge of the excavating blade. I do. In the present embodiment, as described above, the flat donut-shaped earth mass left between the center hole and the large-diameter annular hole is crushed by shaving off with the excavating claw of the excavating blade, or crushing. And remove it, especially on hard ground such as rock.
It is possible to drill the earth mass efficiently with a small force.

According to a sixth aspect of the present invention, in a rock hole drill having a structure according to any one of the first to fifth aspects, a drilling surface of the drill is fixed to the outer casing. It is characterized in that it is positioned so as to protrude axially downward from the toe of the face claw provided. In this embodiment, when drilling, the drilling surface of the drilling drill and the face claws of the outer casing are brought into contact with the ground in this order, and the drilling is performed by the drilling with the button bit of the drilling drill. After forming the small-diameter center hole located at the center of the hole to be formed, since the rotation operation of the face claw of the outer casing forms the large-diameter annular hole located at the outer peripheral edge of the target hole, By drilling in such a stepwise manner, it becomes possible to drill while lowering the ground strength, and even with a hard ground such as rock, a flat donut-shaped earth mass can be efficiently formed with a small force. Can be formed.

According to a seventh aspect of the present invention, there is provided a rock hole drill having a structure according to the fifth aspect,
It is characterized in that the toe of the excavation claw protruding from the excavation blade is positioned axially above the toe of the face claw fixed to the outer casing. In this embodiment, when drilling, the cutting claw of the outer casing and the cutting claw of the cutting blade are brought into contact with the ground in this order, and as described above, between the center hole and the large-diameter annular hole. The leftover donut-shaped earth mass is scraped off with the drilling claw of the drilling blade or crushed to remove it, and the ground is removed by drilling stepwise like this. Drilling can be performed while reducing the strength. In particular, even on a hard ground such as a bedrock, it is possible to drill a soil mass more efficiently with a small force.

According to an eighth aspect of the present invention, there is provided a rock hole drill having a structure according to any one of the first to seventh aspects, wherein the inner casing is provided at an axial lower end opening of the outer casing. A plurality of connection support portions for connecting the outer casing in the radial direction are provided at a predetermined distance in the circumferential direction, and for each of the connection support portions,
An intermediate face claw projecting downward in the axial direction is fixed. In this aspect, the center bit is drilled at the center of the target hole by the button bit of the drilling drill, and the face claw and the intermediate face claw arranged on the outer peripheral side of the center hole are drilled. Is rotated to cut the ground around the center hole into a plurality of rings in the circumferential direction, thereby forming a plurality of layered annular holes so as to overlap in the radial direction. The annular soil mass left between the hole and the multiple layered annular holes,
The intended hole is formed by shaving off and excavating with a drilling blade. Therefore, the strength of the annular soil mass (planar donut-shaped earth mass) left between the center hole formed by the button bit and the outer peripheral edge portion of the target hole (the large-diameter annular hole formed by the face claw) can be reduced. Excavation with the excavation blade can be performed more easily.

According to a ninth aspect of the present invention, there is provided a rock hole drill having a structure according to the eighth aspect,
A plurality of the intermediate face claws are arranged at different positions in a radial direction of the inner casing and the outer casing. In this embodiment, it is possible to set the thickness of each annular soil mass by the intermediate face claw to be small, to secure the thickness of each annular soil mass to be small, and to increase the center hole by the button bit and the large size by the face nail. It is possible to reduce the strength of the entire annular mass left behind between the annular holes, thereby making it easier to drill holes by the excavating blades, and advantageously ensuring drilling efficiency and workability. In addition, it is easy to set the hole diameter of the hole to be larger.

According to a tenth aspect of the present invention, there is provided a rock hole drill having a structure according to any one of the first to ninth aspects, wherein the hole protrudes in an axial direction with respect to an outer peripheral edge of the drilling blade. The present invention is characterized in that a strip-shaped outer peripheral wall plate is fixed. In such an embodiment, the outer peripheral wall plate is slid in contact with the inner peripheral surface of the drilled hole with a surface, so that displacement of the lock hole drill in a direction perpendicular to the axis can be prevented, Drilling operation can be more stabilized, and drilling can be performed more efficiently. In addition, since the outer peripheral wall plate has the shape of a strip, it is possible to prevent the area from becoming unnecessarily large and reduce the rotational resistance. Further, since the outer peripheral wall plate is fixed to the outer peripheral edge of the excavating blade, it is possible to arrange the outer peripheral wall plate substantially uniformly over the entire excavating blade. It can be effectively achieved.

According to an eleventh aspect of the present invention, in a rock hole drill having a structure according to the tenth aspect, the drilling blade has an axially lower portion,
The outer peripheral wall plate is formed so as to protrude upward in the axial direction, while in the upper portion in the axial direction, the outer peripheral wall plate is formed so as to protrude only downward in the axial direction. In such an embodiment, the lower portion of the excavating blade in the axial direction includes:
The excavated soil scraped up by the excavating blade is skillfully placed on the excavating blade by an outer peripheral wall plate protruding upward in the axial direction, thereby efficiently excavating the excavated soil while preventing the excavated soil from falling down. On the other hand, in the axially upper portion of the excavating blade, the excavated soil guided on the excavating blade and raised on the ground is excavated by the outer peripheral wall plate projecting downward in the axial direction. This makes it possible to easily swing down and remove the blade from above the blade, so that good workability can be exhibited.

According to a twelfth aspect of the present invention, there is provided a rock hole drill having a structure according to any one of the first to eleventh aspects, wherein the inner casing has a predetermined rotation at an axially upper end portion. A connecting portion that is detachable from the drive shaft is provided, and through the connecting portion, compressed air for driving the drill is supplied, and rotational driving force is transmitted to the drilling claw and the face claw. The feature is that it is. In this aspect, the lock hole drill can be easily attached to and detached from the drive shaft. There, for example, a plurality of types of rock hole drills having different structures of drilling drills, drilling blades, face claws, or having or not having drilling claws and intermediate face claws are prepared, and according to the state of the ground, Alternatively, in accordance with a change in the ground during drilling, the work can be performed by appropriately replacing the lock hole drill, thereby further improving the drilling efficiency.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 shows a lock hole drill 10 as a first embodiment of the present invention. The lock hole drill 10 includes a drill body 12 positioned at a lower end in the axial direction and a hydraulic motor 14 positioned at an upper end in the axial direction. The drill body 12 and the hydraulic motor 14 are driven by a driving rod 16. Has a longitudinal structure interconnected by Then, as shown in FIG. 2, the lock hole drill 10 is supported at its upper end by a crane arm 20 mounted on the carrier portion of the work truck 18 and is suspended in a substantially vertical state. In addition, drilling work can be performed on the ground. In the present embodiment, the vertical direction refers to the vertical direction in FIGS. 1 and 2 which is a vertical direction in principle.

More specifically, as shown in an enlarged manner in FIG. 3, the drill body 12 includes a cylindrical case fitting 22 as an inner casing. , Down the hole 2 as a drill
4, a drilling screw 26 as an excavating blade, and an outer pipe 28 as an outer casing are assembled.

The cylindrical case fitting 22 is formed of a rigid material such as steel and has a cylindrical shape. Although not shown in the drawing, an air cylinder is formed near the lower end thereof. At the same time, an air supply passage extending from the upper end surface in the axial direction to the air cylinder on the central axis is formed.
A button bit 30 is fixed to a piston member slidably incorporated in the air cylinder. The button bit 30 projects axially downward from the lower end opening of the cylindrical case fitting 22. Located, thereby defining a down-the-hole 24. The detailed structure of the down the hole 24 is described in, for example, Japanese Patent Publication No. 55-25265 and Japanese Patent Publication No. 57-35.
As disclosed in Japanese Patent Publication No. 356, Japanese Patent Publication No. 58-53545, etc., it is a conventionally known one, and details thereof are omitted here. By the action of compressed air supplied from above through the air supply passage in 22, the piston member is shockably driven downward in the air cylinder to vertically vibrate the button bit 30 formed integrally with the piston member. It has become.

As is well known, a large number of hard spherical projections 32 made of diamond chips and the like protruding from the tip end surface of the button bit 30 are brought into contact with the drilled surface of the ground, and are provided at the upper end. By applying the rotational driving force of the hydraulic motor 14 to the down the hole 24 and rotating the button bit 30 at low speed around the central axis, the ground is crushed and drilled and excavated. They are going to make holes.

On the outer peripheral surface of the cylindrical case fitting 22,
A drilling screw 26 is fixedly provided. Such a drilling screw 26 has a substantially constant width, a constant lead angle and a pitch,
The cylindrical case fitting 22 is spirally wound over substantially the entire length in the axial direction, and is fixed to the outer peripheral surface of the cylindrical case fitting 22 in a tightly contacted state by welding or the like. Furthermore, near the lower end of the cylindrical case fitting 22, a partial screw 34 is wound spirally with a length of less than one turn at a position that is axially symmetric with respect to the drilling screw 26. Similarly to 26, it is welded to the cylindrical case fitting 22. In short, at the lower end of the cylindrical case fitting 22, the drilling screw 2
6 and the partial screw 34 form a two-blade structure. In addition, these drilling screw 26 and partial screw 34
At the lower end edge of each of them, a plurality of inner peripheral tip claws 36 as excavating claws projecting obliquely downward are fixedly provided.

The inner peripheral claw 36 is inclined downward toward one side (the front side in the rotational direction around the center axis of the hole to be described later) and protrudes downward, and is made of a superalloy containing titanium or the like. Is formed. Also, the lower end edges of the drilling screw 26 and the partial screw 34 project axially downward on the outer peripheral side away from the cylindrical case fitting 22 than on the inner peripheral side near the cylindrical case fitting 22. The plurality of inner peripheral tip claws 36 fixed to the respective edge portions are also located farthest from the cylindrical case fitting 22 from those closest to the cylindrical case fitting 22. Up to the positioned tip, the position of the protruding tip of the inner peripheral tip claw 36 is gradually located axially downward.

Further, even when the inner peripheral tip claw 36 is located at the outermost peripheral position located at the lowermost position in the axial direction, its protruding tip is formed by the cylindrical case fitting 22 protruding from the button bit 30 of the down-the-hole 24. Are located axially above the lower end surface by a predetermined dimension.

Further, an outer tube 28 is externally arranged at the lower end in the axial direction of the cylindrical case fitting 22 so as to cover the outer peripheral surface of the drilling screw 26. This outer tube 2
8 is a drilling screw 2 having a larger diameter than the cylindrical case fitting 22.
6 and an inner diameter substantially the same as the outer diameter of the cylindrical case fitting 22.
It has a cylindrical shape with a smaller axial length than that, and is made of a rigid material such as steel. A plurality of holes 38 are formed in the outer pipe 28 as windows for discharging the earth.
The outer tube body 28 is connected to the cylindrical case fitting 22.
Screw 26 and partial screw 34 fixed to the
And the inner peripheral surface of the outer pipe 28 is substantially superimposed on the outer peripheral surfaces of the drilling screw 26 and the partial screw 34,
An outer tube 28 is welded to both screws 26,34. In short, the cylindrical case fitting 22, the drilling screw 26 (partial screw 34), and the outer tube 28 are fixed to each other, and are integrally rotated on the central axis as a whole.

The lower end of the outer tube 28 in the axial direction does not reach the same axial position as the lower end of the cylindrical case fitting 22 in the axial direction. While being positioned a distance above,
The bore screw 26 and the partial screw 34 are positioned axially lower than any of the inner peripheral claw 36 of the inner peripheral claw 36 fixed thereto.

Further, a plurality of outer peripheral tip claws 40 as face claws are fixed to the peripheral edge of the lower end opening of the outer pipe body 28 at predetermined intervals in the circumferential direction over the entire circumference in the circumferential direction. Each of the outer peripheral claw 40 is projected obliquely downward toward one side in the circumferential direction that is forward in the rotation direction,
A cutting blade 42 inclined in an edge shape is formed at the tip portion. In particular, in the present embodiment, the cutting blade portions of the plurality of cutting blades 42 are positioned axially above the lower end surface of the cylindrical case fitting 22, and the excavation tip surface (the drilling surface) of the button bit 30 is formed. ) In the axial direction and axially below the cutting edge positioned at the lowermost end of the inner peripheral tip claw 36 in the drilling screw 26 and the partial screw 34.

Particularly, in the present embodiment, each of the plurality of inner peripheral tip claws 36 in the outer tube 28 is formed by brazing a cemented carbide such as titanium to a sheet metal. It is formed by welding to the periphery of the opening of the body 28. Moreover, each of these inner peripheral tip claws 36
Is protruded so as to extend obliquely downward toward one side in the circumferential direction so that the cutting edge is positioned obliquely forward in the rotation direction of the outer pipe body 28.

In short, in the present embodiment, the outer pipe 2
8 of the outer peripheral tip claw 40 (at least the cutting edge 42).
The tip of the button bit 30 of the down-the-hole 24 on the center axis of the drill body 12
The drilling screw 26 is disposed so as to be located at least between the cutting edges (tips) of the inner peripheral tip claws 36 in the drilling screw 26. As a result, the button bit 30 of the down-the-hole 24 and the inner peripheral tip claw 3 of the drilling screw 26 extend radially inward from the center axis of the drill body 12.
6, the outer tip 28 is positioned and set in the order of the outer tip claw 40, and the button bit 30, the outer tip claw 40, and the inner tip claw 3 are arranged from the lower side in the axial direction to the upper side.
6 are positioned and arranged. Further, the inner peripheral tip pawl 36 and the outer peripheral tip pawl 40 are fixed to each other so as not to be displaceable relative to each other.

The drill body 12 has a drive rod 16 and a cushion joint 44 at the upper end in the axial direction.
It is connected to an output shaft 46 of the hydraulic motor 14 via 44 and the like. The drive rod 16 is a cylindrical tube, made of a steel material, and has a rotating rod 50 inserted into an inner hole 48 thereof. The lower end of the rotating rod 50 in the axial direction is connected via the cushion joint 44.
While being coaxially connected to the drill body 12,
An output shaft 46 of the hydraulic motor 14 is coaxially connected to the upper end in the axial direction via a cushion joint 44 and an air swivel 52. Further, the air swivel 52 includes a housing 56 fixedly supported by a support frame 54 extending downward from the hydraulic motor 14, and the output shaft 46 is inserted into the housing 56 so as to be rotatable around a central axis. Have been. On the other hand, the output shaft 46, the cushion joint 44, and the rotary rod 50 extending downward from the air swivel 52, though not explicitly shown in the drawing, have air passages extending over their respective central axes and communicating with each other. Are formed, and the air swivel 52
Compressed air supplied from the outside through an air supply port 58 fixed to the housing 56 is supplied to the down-the-hole 24 of the drill body 12 through such an air passage.

The lock hole drill 10 having such a structure is mounted on a work truck 18 as shown in FIG. Work truck 18
Is equipped with a crane mechanism 60 in the carrier part, and is provided to project upward from the hydraulic motor 14 of the lock hole drill 10 with respect to a support rod 62 fixed to a tip end portion of the crane arm 20 in the crane mechanism 60. The lock hole drill 10 is suspended and supported by the crane arm 20 by locking and fixing the mounting bracket 64 with the mounting pin 66, and the lock hole drill 10 allows a hole substantially perpendicular to the ground to be formed. It can be drilled.

That is, such a lock hole drill 10
When drilling using a drill, the lock hole drill 10 is suspended and supported substantially vertically by the clean arm 20 of the work truck 18 as described above, and as shown in FIG. The lower end face, that is, the tip end face of the button bit 30 is aligned with the drilling position on the ground 68 and brought into contact therewith. Then, the hydraulic motor 14 is operated to rotate the entire drill body 12 continuously or intermittently around the central axis, and compressed air is supplied through the air supply port 58 of the air swivel 52 to supply the down-the-hole 24. Button button 30 is repeatedly projected. Accordingly, first, the button bit 30 of the down the hole 24 excavates while hitting and crushing the center portion of the hole to be formed in the ground 68,
A circular hole 70 smaller in diameter than the target hole is drilled at the center of the target hole.

Subsequently, when the rotary driving of the drill body 12 by the hydraulic motor 14 and the driving of projecting the down-the-hole 24 by the compressed air are continued, the ground on the outer peripheral side of the circular hole 70 cut by the down-the-hole 24 is continued. 68
The outer peripheral tip claw 40 of the outer tube 28 is brought into contact with the surface of the outer tube 28, and is driven to rotate around the central axis. An annular hole 72 having an annular shape extending in the circumferential direction on the same central axis is drilled. This annular hole 72 is
It is formed in the same radial dimension as the inner diameter of the target hole.

As a result, as shown in FIG. 5, between the circular hole 70 and the annular hole 72 in the radial direction, a flat donut shape extending in the depth direction and remaining as a whole thick cylindrical shape is formed. A lump 74 will be formed in the ground 68.

When the rotary drive of the drill body 12 by the hydraulic motor 14 and the driving of the down-the-hole 24 to be protruded by the compressed air continue as described above, the inner peripheral tips provided on the drilling screw 26 and the partial screw 34 are formed. The claw 36 is brought into contact with the surface of the remaining lump 74 left between the circular hole 70 and the annular hole 72, whereby the remaining lump 74 is excavated.

Here, the remaining lump 74 is formed in a cylindrical shape in which the inner and outer peripheral portions are cut off by the circular hole 70 and the annular hole 72, so that the strength is reduced. 26 and partial screw 3
Since the inner peripheral claw 36 provided on the outer peripheral side is brought into contact with the remaining lump 74 in order from the outer peripheral side, the remaining lump 74 is efficiently formed by the inner peripheral tip claw 36. It can be crushed and drilled to be scraped. That is, as shown in FIG. 5, the inner peripheral tip claw 36 in contact with the remaining mass 74 exerts a drilling force on the remaining mass 74 in a tangential direction of a circumference around the rotation center axis. However, if the inner peripheral claw 36b located on the inner peripheral side first contacts the residual mass 74, the drilling force (the residual mass 7
4 is exerted over a wide range from the inner peripheral portion to the outer peripheral portion of the remaining lump 74. On the other hand, in the present embodiment, since the inner peripheral tip claw 36a located on the outer peripheral side first contacts the remaining lump 74, the drilling force toward the outer peripheral side is exerted on a relatively narrow region. By reducing the reaction force or resistance of the remaining mass 74, the remaining mass 74 can be easily crushed and bored with a relatively small rotational driving force. Is crushed, the area of the drilling force exerted on the remaining mass 74 by the contact of the inner peripheral tip claw 36a on the inner peripheral side becomes relatively small, and the binding force by the outer peripheral portion of the remaining mass 74 is released. First, the remaining lump 74
The crushing and drilling can be performed with a sufficiently small driving force as compared with the case of crushing the inner peripheral portion of the slab.

Also, in this manner, the inner peripheral tip claw 36
A residual mass 74 crushed at a and b and cut off from the ground 68
Are placed on the drilling screw 26 squeezed rearward in the rotation direction of the inner peripheral claw 36a, b, and sequentially pushed up from below, while being guided by the drilling screw 26, the inside of the drilling screw is removed. Is sent upward and is discharged on the surface of the ground 68. Then, as a result, the target inner diameter, that is, the annular hole 7 drilled by the outer pipe 28 is formed.
A hole having an inner diameter of 2 can be completed.

Therefore, in the rock hole drill 10 having the above-described structure, even if the ground 68 has a large hardness such as a bedrock, the down-the-hole 24 having a small diameter is used to form a hole having a large inside diameter, such as a telephone pole. Holes for pillars,
It is possible to drill efficiently, and it is possible to reduce the cost of construction compared to using a rock drill or a large down the hole with an outer diameter corresponding to the target hole diameter While it is possible, the construction time can be shortened.

In particular, since the drilling by the down-the-hole 24 is performed in advance, the outer pipe body 28 that follows thereafter is drilled.
When drilling by the outer peripheral tip claw 40, the drilling screw 26, and the inner peripheral tip claw 36 of the partial screw 34, the ground 68
Is also expected to reduce the hardness of the steel, thereby further reducing the driving force required for drilling as a whole.

In this embodiment, the drilling screw 26
Further, the inner and outer peripheral edges of the partial screw 34 are in close contact with the cylindrical case fitting 22 and the outer tube 28, and the drilling of the remaining mass 74 by the drilling screw 26 and the inner peripheral tip claw 36 of the partial screw 34 is performed by the cylindrical screw. Since the excavation is performed in the space between the case metal fitting 22 and the outer pipe 28, the excavated soil can be prevented from leaking from the drilling screw 26 and can be efficiently discharged from the drilling hole.

Furthermore, in the present embodiment, drilling is performed by hybrid drive in which the down-the-hole 24 driven by the pneumatic hammer and the rock auger screw 26 driven by the rotation of the hydraulic motor 14 are combined. Thus, the rotational driving force of the hydraulic motor 14 can be set small, and the size of the motor provided on the upper portion can be further reduced in size and weight.

Next, a lock hole drill according to a second embodiment of the present invention is shown in FIGS. In addition,
In the following description, members and parts having the same structure as the lock hole drill (10) as the first embodiment shown in FIG. 1 are the same as those in the first embodiment in the drawing. , The detailed description thereof is omitted.

That is, the lock hole drill according to the present embodiment is different from the drill body (1) according to the first embodiment.
It shows another specific example of 2).

More specifically, the upper end opening 78 of the cylindrical case fitting 22 as the inner casing of the drill body 76 is formed in a substantially regular hexagonal shape. A protruding connection rod 80 having a substantially regular hexagonal cross section is inserted so as not to rotate relatively.

The cylindrical case fitting 22 is externally inserted into the down-the-hole 24 from above in the axial direction, and the connecting rod 80 of the down-the-hole 24 is fitted into the upper end opening 78 of the cylindrical case fitting 22. Since the connecting pin 82 is inserted in the direction perpendicular to the axis with respect to the upper end of the cylindrical case fitting 22 in which the connecting rod 80 is inserted, the connecting pin 82 is connected and fixed so as not to be relatively displaceable in the circumferential direction and the axial direction. I have. In the drill body 76 thus configured, the upper end of the connecting rod 80 of the down-the-hole 24 protrudes from the upper end surface of the cylindrical case fitting 22, and the upper end of the connecting rod 80 connects the hydraulic motor 14 and the like. The lock hole drill is configured by being fitted into the provided drive rod 16 and connected and fixed to the drive rod 16 with a bolt, a pin, or the like. In addition, connecting rod 8
Although not explicitly shown in the drawing, an air passage extending on the central axis is formed in the center portion of the drive rod 0, and the air passage is supplied from the air swivel (52) through the inside of the drive rod 16 (the air passage of the drive rod 16). The compressed air to be supplied is supplied to the down the hole 24 of the drill body 76 through the air passage. In addition, as is clear from the above description, in this embodiment, the connecting portion of the drill body 76 is constituted by the connecting rod 80 of the down the hole 24.

Also, on the outer peripheral edge of the drilling screw 26,
An earth discharging guard plate 84 as an outer peripheral wall plate is fixedly provided. This earth discharging guard plate 84 has a thin band shape,
It is formed of a rigid material such as steel, and protrudes in the axial direction with respect to the outer peripheral edge of the drilling screw 26. In particular, in the present embodiment, the projecting direction of the earth discharging guard plate 84 is made different between the axially lower portion and the axially upper portion of the drilling screw 26, and is substantially two-way from the axial lower end of the drilling screw 26. In the lower part in the axial direction located at the winding half, the guard plate 84 for discharging earth is provided.
a is protruded upward in the axial direction, and above it, that is, in the upper part in the axial direction located approximately two and a half turns from the upper end in the axial direction of the drilling screw 26, the earth discharging guard plate 84b
Are protruded downward in the axial direction. Note that the inner peripheral tip claw (36) disposed at the lower end portion of the drilling screw 26 in the first embodiment is not necessarily provided in the drilling screw 26 of the present embodiment.

Further, an outer tubular metal fitting 86 as an outer casing is provided at a lower end in the axial direction of the cylindrical case fitting 22 (the drilling screw 26). The outer tube fitting 86 has a cylindrical shape, is larger in diameter than the cylindrical case fitting 22, has substantially the same inside diameter as the outside diameter of the drilling screw 26, and is substantially the same as the earth discharging guard plate 84. It has a slightly larger axial length. Also, at the lower end opening of the outer tubular metal fitting 86, three connecting plates 88 as connecting supporting parts extending radially inward toward the cylindrical case fitting 22 are formed at predetermined intervals in a circumferential direction, The outer tubular fitting 84 and the tubular case fitting 22 are connected by these connecting plates 88. A substantially fan-shaped through hole 90 is formed between each of the three connecting plates 88, 88, 88.
Through these through holes 90, the space between the radially facing surfaces of the tubular case fitting 22 and the outer tubular fitting 24 is opened downward. In the same manner as in the outer tube body (28) in the first embodiment, the outer tube fitting 84 is provided with a peripheral tip claw 40 at a lower end edge thereof in a predetermined circumferential direction over the entire circumferential direction. The tip (cutting edge) of the cutting claw 42 is positioned axially below the lower end surface of the cylindrical case fitting 22 while the button bit 30 is drilled in the down-the-hole 24. It is located axially above the plane.

Each connecting plate 88 has a plurality of intermediate tip claws 92 as intermediate face claws projecting downward in the axial direction. These intermediate tip claws 92 are connected to the respective connecting plates 88.
In this embodiment, two are provided.
These intermediate tip claws 92, 96 are spaced apart in the radial and circumferential directions. In addition, these intermediate tip claws 9
The projection height of the outer chip 82 is substantially the same as that of the outer tip claw 40 of the outer cylindrical metal fitting 86, and the tip (cutting edge) of the outer tip claw 40 is the tip (the cutting claw 42).
(The cutting edge portion of the cutting edge portion) is located at substantially the same height in the axial direction.

When drilling a hole using the lock hole drill of the present embodiment provided with such a drill body 76, compressed air is first supplied from the air swivel (52) as in the first embodiment. Then, the button bit 30 of the down hole 24 is repeatedly protruded to form a small circular hole (70) at the center of the target hole.

Subsequently, as in the first embodiment, by continuously rotating the drill body 12 by the hydraulic motor 14 and projecting the down-the-hole 24 by compressed air, the ground on the outer peripheral side of the circular hole (62) is formed. By contacting the outer peripheral claw 40 of the outer cylindrical metal fitting 86 with the intermediate tip claw 92 of the connecting plate 88 against the surface, and rotating around the center axis of the drilling hole, the outer peripheral side of the circular hole (62) is formed. A plurality of annular cutting grooves extending in the circumferential direction are drilled in the ground.
Thereby, a plurality of layered annular holes are formed so as to overlap in the radial direction around the circular hole (62). Then, the annular soil mass left between the circular hole (62) and the plurality of layered annular holes is scraped off by the drilling screw 26 through the through hole 90 of the connecting plate 88 and the soil is discharged to form a target hole. It can be formed.

Therefore, even in the lock hole drill having the above-described structure, the same effects as those of the first embodiment can be effectively exhibited, and the circular hole (62) formed by the button bit 30 can be obtained. In addition, the strength of the annular earth mass left between the outer peripheral edge portions of the target hole can be made smaller by the plurality of layered annular holes formed by the outer peripheral tip claw 40 and the intermediate tip claw 92, and the drilling screw 26 Excavation at the site can be performed more easily.

In this embodiment, since the mounting of the drill body 76 is performed by the easily attachable / detachable connecting rod 76, the drill body (12) in the first embodiment and the drill body described later are used. The various drill bodies having different shapes and structures, such as the drill body (94) in the third embodiment, can be easily attached and detached and exchanged, whereby the state of the ground or the ground during drilling can be obtained. In accordance with the change, the work can be easily performed by adopting an appropriate drill main body, and the drilling work can be made more efficient.

Further, in this embodiment, the drilling screw 2
6 is provided with the guard plate 84 for discharging, so that the guard plate 84 for discharging can be brought into sliding contact with the inner peripheral surface of the drilled hole. Thus, the displacement of the lock hole drill in the direction perpendicular to the axis can be prevented, and the drilling operation can be further stabilized. Further, the provision of the earthing guard plate 84 makes it possible to reduce the axial length of the outer tubular metal member 86, thereby reducing the screw rotational resistance during drilling.

Further, the guard plate 84 for discharging the earth is formed so as to protrude upward in the axial direction at the lower portion in the axial direction of the drilling screw 26, while it is protruded downward in the axial direction at the upper portion in the axial direction. The lower part of the drilling screw 26 in the axial direction is
The excavated soil scraped up by the drilling skill is efficiently placed on the drilling screw 26 efficiently while preventing the excavated soil from spilling down by an earth discharging guard plate 84a protruding upward in the axial direction. On the other hand, in the upper part of the drilling screw 26 in the axial direction, the excavated soil guided on the drilling screw 26 and raised on the ground is projected downward in the axial direction. The removed earth guard plate 84b makes it possible to easily swing down and remove the drilled screw 26 from above, so that good earth removal workability can be exhibited.

Next, a lock hole drill according to a third embodiment of the present invention is shown in FIGS. In addition,
In the following description, members and portions having the same structure as the lock hole drill (10) according to the first or second embodiment shown in FIG. The same reference numerals as in the second embodiment denote the same parts, and a detailed description thereof will be omitted.

That is, the lock hole drill according to the present embodiment is different from the drill body (1) according to the first embodiment.
It shows another specific example of 2).

More specifically, the drill body 9 of the present embodiment
The outer pipe 28 in 4 has an axial length (total length) set smaller than the outer pipe (28) in the first embodiment.

In this embodiment, the drilling screw 26 is used.
The inner peripheral claw 36 is disposed so as to be gradually located on the central axis of the drilling hole from the outer peripheral side toward the inner peripheral side at the lower end edges of the drilling screw 26 and the partial screw 34.

In this embodiment, the guard plate 84 for discharging the earth is formed so as to project axially downward with respect to the outer peripheral edge of the drilling screw 26. The earth discharging guard plate 84 is provided only in a portion of the drilling screw 26 that is positioned axially above the outer pipe 28.

Therefore, also in the lock hole drill having such a drill body 94, similarly to the first embodiment, the rotation drive of the drill body 12 by the hydraulic motor 14 and the protrusion drive of the down-the-hole 24 by the compressed air are performed. The effect of lowering the hardness of the ground can be exerted, and the same effects as those of the first embodiment can be effectively exerted.

The embodiment of the present invention has been described in detail above, but this is merely an example.
By the specific description in such an embodiment,
It cannot be construed as limiting.

For example, in the above-described embodiment, the inner peripheral tip pawl 36 and the outer peripheral tip pawl 40 are integrally rotated about the center axis of the drilling hole. For example, the cylindrical case fitting 22 and the outer pipe By rotating the body 28 in opposite directions about the central axis or at different rotational speeds, the drilling force and resistance of the tip claws 36 and 40 are adjusted, and the drilling reaction force is reduced. It is also possible.

Further, in the first embodiment, the outer pipe 28 is provided only at the lower end in the axial direction of the cylindrical case fitting 22.
Although it is arranged so as to cover approximately half the length, the length is not limited. For example, it is arranged so as to cover the entire cylindrical case fitting 22. May be.

Further, in the second embodiment, the drilling screw 26 may be made to protrude axially below the connecting plate 88 through the through hole 90.

Further, the drive motor of the drilling screw 26 used in the above embodiment is not limited at all, and a pneumatic or electric drive motor can be used in addition to the hydraulic motor 14 as illustrated. is there.

In addition, although not enumerated one by one, the present invention
Various changes, modifications, improvements, etc. can be made based on the knowledge of those skilled in the art, and unless such embodiments depart from the spirit of the present invention.
Both are included in the scope of the present invention,
Needless to say.

[0072]

As is apparent from the above description, in the lock hole drill having the structure according to the present invention,
By performing the drilling by hitting the drilling drill and the drilling by the face claw fixed to the outer casing, the ground at the outer peripheral portion of the drilling drill is cut in an annular shape. Even if the drilling ground is hard rock, drilling can be performed easily and quickly with a small driving force.

[Brief description of the drawings]

FIG. 1 is a front view showing a lock hole drill as a first embodiment of the present invention.

FIG. 2 is an overall schematic diagram showing a state in which the lock hole drill shown in FIG. 1 is mounted on a work truck.

FIG. 3 is an enlarged longitudinal sectional view showing a main part of the lock hole drill shown in FIG. 1;

FIG. 4 is an explanatory longitudinal sectional view for explaining drilling using the lock hole drill shown in FIG. 1, and FIG.
It is a figure corresponding to IV-IV cross section.

FIG. 5 is a sectional view taken along line VV in FIG. 4;

FIG. 6 is a front view of a drill main body constituting a lock hole drill according to a second embodiment of the present invention.

FIG. 7 is a bottom view of the drill body shown in FIG. 6;

FIG. 8 is a front view of a drill main body constituting a lock hole drill according to a third embodiment of the present invention.

FIG. 9 is a bottom view of the drill body shown in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lock hole drill 22 Cylindrical case metal fitting 24 Down the hole 26 Drilling screw 28 Outer tube 30 Button bit 40 Outer peripheral tip nail

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D029 CA02 CA03 CB05 CC02 CD03 ED01 PA01 PB05 PD02

Claims (12)

[Claims] 1. A hollow in which a cylindrical inner casing suspended from and supported on a drilling center axis and a button bit protruding from a lower end of the inner casing are repeatedly operated by compressed air to perform drilling. A pressure impact drilling drill; a drilling blade protruding from the outer peripheral surface of the inner casing and fixed so as to extend helically in the axial direction; and being spaced apart from an outer peripheral side of a lower portion of the inner casing. A lock having a cylindrical outer casing, and a plurality of face claws fixed to a peripheral edge of a lower end of the outer casing and positioned on a circumference around a central axis of the hole. Hole drill. 2. The outer casing is fixed to the excavating blade, and the outer casing and the excavating blade are integrally rotated in the same circumferential direction about the drilling center axis. Item 2. A lock hole drill according to Item 1. 3. An outer peripheral edge of the excavating blade is fixed in close contact with the inner casing, and an outer peripheral edge of the excavating blade is fixed in close contact with the outer casing. Item 3. A lock hole drill according to Item 2. 4. The lock hole drill according to claim 1, wherein a plurality of earth discharging windows are provided through the outer casing. 5. A plurality of excavating claws projecting from a lower end edge of the excavating blade, and the toes of the excavating claws are gradually cut from an inner peripheral side to an outer peripheral side at a lower end edge of the excavating blade. The lock hole drill according to any one of claims 1 to 4, wherein the lock hole drill is disposed so as to be located below the hole center axis. 6. The drilling drill according to claim 1, wherein the drilling surface of the drilling drill projects axially downward from the toe of the face claw fixed to the outer casing. Rock hole drill. 7. The lock according to claim 5, wherein the toe of the excavating claw protruding from the excavating blade is positioned axially above the toe of the cutting claw fixed to the outer casing. Hole drill. 8. A plurality of connection support portions for connecting the inner casing and the outer casing in a radial direction at a lower end in the axial direction of the outer casing at a predetermined distance in a circumferential direction, and providing a plurality of connection support portions. The lock hole drill according to any one of claims 1 to 7, wherein an intermediate face claw protruding downward in the axial direction is fixed to the portion. 9. The lock hole drill according to claim 8, wherein a plurality of the intermediate face claws are arranged at different positions in a radial direction of the inner casing and the outer casing. 10. The rock hole drill according to claim 1, wherein a band-shaped outer peripheral wall plate protruding in the axial direction is fixed to an outer peripheral edge of the excavating blade. 11. In the excavating blade, the outer peripheral wall plate is formed so as to protrude upward in the axial direction at a lower portion in the axial direction, and the outer peripheral wall plate is directed downward in the axial direction at an upper portion in the axial direction. The lock hole drill according to claim 10, wherein the lock hole drill is formed to protrude only. 12. An axially upper end of the inner casing is provided with a connecting portion detachable from a predetermined rotary drive shaft, and supplies compressed air for driving the drill for drilling through the connecting portion. The lock hole drill according to any one of claims 1 to 11, wherein a rotational driving force is transmitted to the excavation claw and the face claw.