JP6088154B2 - Drilling tools - Google Patents

Description

  The present invention relates to a drilling tool that expands or contracts a hole to be drilled in the ground or a natural ground in order to install an anchor, a lock bolt, a foundation pile, or the like.

  At excavation sites such as mines and tunnels, anchors and rock bolts are installed in holes excavated in natural ground to reinforce natural ground. Furthermore, in order to reinforce the natural ground more firmly, an enlarged portion with an enlarged inner diameter is formed at the tip and middle of the hole through which the anchor and lock bolt penetrate, and the filling volume of cement and mortar in this portion is increased. An increase is being made.

  As a drilling tool for forming a hole having such an enlarged diameter portion, Patent Document 1 discloses that a bit is projected and retracted in a radial direction by a wedge-shaped member that advances and retreats in the axial direction of the drill bit body. Thus, a configuration that enables expansion and contraction of the hole is disclosed.

  Further, in Patent Document 2, the bit body for excavation having a bit head composed of two blocks is rotated, and the bit head is pressed against the ground around the hole, thereby rotating the two blocks constituting the bit head. The structure which provides resistance and makes two blocks protrude in the outer peripheral side is disclosed.

JP 7-229382 A Japanese Unexamined Patent Publication No. Sho 63-11789

  However, according to the configuration described in Patent Document 1, a wedge-shaped member and a mechanism for advancing and retracting the member are required to make the bit appear and disappear in the radial direction, and the structure is complicated and costly. There is a problem that it takes.

  The excavation bit described in Patent Document 2 is an excavation bit intended to start excavation in a diameter-expanded state at the start of excavation, and to recover the bit after reducing the diameter. Therefore, this drill bit is not assumed to have an enlarged / reduced diameter in the middle of work, and even when trying to shift from the reduced diameter state to the enlarged diameter state in the hole, in this drill bit configuration, the hitting is only in the axial direction of the hole. Since it does not apply, it is impossible to generate a force for pressing the bit head against the inner surface of the hole, and it is impossible to dig the hole wall and expand the diameter.

  Such a problem is common not only when forming holes for foundation piles built in the ground, but also for holes for anchors and rock bolts.

    An object of the present invention made there is to provide an excavation tool that can reliably expand and contract holes while being inexpensive.

The present invention employs the following means in order to solve the above problems.
That is, the present invention has an excavation tool main body and a movable blade body swingably provided on the excavation tool main body, and when the excavation tool main body is rotated around its axis, the movable blade body is The excavating tool swings around its rear end side, and the tip end side of the movable blade body protrudes to the outer peripheral side to expand the diameter of the excavated hole , the tip end surface of the excavating tool body and the movable blade The distal end surface of the body has an inner portion that is circular on the inner peripheral side in a reduced diameter state, and a gauge portion that is annularly disposed on the outer peripheral side of the inner portion . An inclined surface inclined so as to go to the rear end side in the axial direction as it goes from the peripheral side to the outer peripheral side, and a tip is implanted on the inclined surface constituting the gauge portion, and the excavation tool body Is arranged on the rear end side and has a cylindrical shape A columnar portion and a plate-like portion having a pair of plane portions formed on the tip side and parallel to each other across the axis, and the movable blade body is provided on both sides of the excavation tool body, respectively. And is pivotally connected to a shaft portion provided on the flat portion of the excavation tool body so as to be swingable in a plane along the flat portion, and the plane of the plate-like portion The part is formed with a convex part having a certain height in a direction perpendicular to the surface of the flat part, and the movable blade body has a flat part facing the flat part of the plate-like part. A concave portion having a certain depth is formed in the flat portion of the movable blade body in a direction orthogonal to the surface of the flat portion, and the swing of the movable blade body is caused by the contact of the convex portion and the concave portion. It is characterized by a stopper for restricting the angle is provided .
According to such a configuration, when the excavating tool main body is rotated around its axis, the movable blade swings around the rear end side, and the front end side of the movable blade body protrudes to the outer peripheral side. The tip side of the body contacts the inner wall surface of the surrounding hole. As a result, the rotation of the movable blade is delayed from the rotation of the excavation tool main body by the frictional resistance, so that the movable blade is forcibly swung and opened. By excavating in this state, the hole diameter is expanded.
Here, the excavation tool main body is disposed on the rear end side, and has a plate-like shape having a columnar portion and a pair of plane portions formed on the front end side and parallel to each other across the axis. And the movable blade body is provided on both sides of the excavation tool main body and is rotatably connected to a shaft portion provided on the flat portion of the excavation tool main body. It is possible to adopt a configuration that is provided so as to be able to swing in the plane along.
Further, it is preferable that the shaft portion is provided so as to be offset on one side of the plane portion with the axis line interposed therebetween.
Further, the flat portion of the plate-like portion is formed with a convex portion having a certain height in a direction perpendicular to the surface of the flat portion, and the movable blade body is a flat portion of the plate-like portion. A concave portion having a certain depth is formed in the plane portion of the movable blade body in a direction orthogonal to the surface of the plane portion, and these convex portion and the concave portion abut against each other. Accordingly, a stopper is provided for regulating the swing angle of the movable blade body .

  The present invention can be used not only when forming holes for anchors and rock bolts, but also when forming holes for foundation piles built in the ground.

According to the present invention, when the excavation tool body is rotated about its axis , the movable blade body swings around the rear end side, and the front end side of the movable blade body protrudes to the outer peripheral side, whereby the movable blade body The tip end side of this contacts the inner wall surface of the surrounding hole. Thereby, the movable blade is forcibly swung and expanded in diameter by the frictional resistance, and the hole can be expanded in diameter.
Such an excavation tool does not require a complicated mechanism for operating the movable blade body, and it is possible to reliably expand and contract the hole while being inexpensive.

It is a figure which shows the excavation tool which concerns on this embodiment, (a) is the perspective view seen from the front end side, (b) is the perspective view seen from the rear end side. It is a perspective view which shows the components structure of an excavation tool. It is a figure which shows a movable blade body, (a) is the perspective view seen from the outer peripheral surface side, (b) is the perspective view seen from the plane part side. It is a figure which shows operation | movement of an excavation tool, (a), (b) is the side view and front view of a diameter-reduced state, (b) is the side view and front view of a diameter-expanded state. so It is a perspective view which shows the state which the movable blade body expanded.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best mode for carrying out an excavation tool according to the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited only to these examples.
FIG. 1 shows an embodiment of the present invention. In the present embodiment, the excavation tool 1 is formed of a steel material or the like, and has a substantially cylindrical shape with the axis O as a whole. The rear end portion 1b of the excavation tool 1 is formed with an attachment means for attaching the excavation tool 1 to the tip of a rod (not shown) extending from the rock drill, for example, an attachment screw hole 2. A tip 3 made of a material such as a cemented carbide harder than the excavating tool 1 is implanted at the tip 1a of the excavating tool 1. Such a drilling tool transmits the rotational force around the axis O given from the rock drill, the striking force in the direction of the axis O, and the thrust from the tip 3 to the rock, and drills while crushing the rock. go.

    As shown in FIG. 2, the excavation tool 1 has a three-part structure on the tip side. That is, the excavation tool 1 includes an excavation tool main body 10 and a pair of movable blade bodies 20 and 20 that are swingably attached to the distal end side of the excavation tool main body 10.

The excavation tool body 10 has a columnar portion 11 on the rear end side and a plate-like portion 12 having a pair of flat portions 12a and 12a formed in parallel with each other with the axis O interposed therebetween. Yes.
A cylindrical shaft portion 13 is formed so as to protrude from the flat portions 12 a and 12 a of the plate-like portion 12. This shaft portion 13 has a central axis in a direction perpendicular to the axis O of the excavation tool body and also perpendicular to the plane portion 12a, and one side in the width direction of the plane portion 12a (direction perpendicular to the axis O). Is provided offset.
On one end side of the flat surface portion 12 a of the plate-shaped portion 12, a wall portion 12 b is formed at the boundary with the cylindrical portion 11 so as to rise from the flat surface portion 12 a to the outer peripheral surface 11 a of the cylindrical portion 11. The wall portion 12 b is a curved surface concentric with the center of the shaft portion 13. In the wall portion 12b, a groove 12m that is continuous in a plane parallel to the plane portion 12a and that is concave on the outer diameter side of the curved wall portion 12b is formed on the side close to the plane portion 12a.

    Further, the flat portion 12a of the plate-like portion 12 is formed with a convex portion 14 having a certain height in a direction orthogonal to the surface of the flat portion 12a. The convex portion 14 has a stopper surface 14 a that rises orthogonal to the flat surface portion 12 a on the side facing the shaft portion 13.

    As shown in FIG. 3, the movable blade body 20 has a flat surface portion 20 a on one surface side, an arc surface 20 b having the same size as the outer diameter of the excavation tool 1 on the other surface side, and orthogonal to the axis O. The in-plane cross-sectional shape is D-shaped. The movable blade body 20 is provided on both sides of the plate-like portion 12, and is mounted on the plate-like portion 12 with the flat portion 20a facing the flat portion 12a of the plate-like portion 12, respectively. In this state, as shown in FIG. 1, the plate-like portion 12 and the movable blades 20, 20 on both sides form a cylindrical shape that continues to the cylindrical portion 11 as a whole.

    As shown in FIG. 2, a hole 22 through which the shaft portion 13 is inserted is formed on one end side of the movable blade body 20. As shown in FIG. 1, the shaft portion 13 penetrates the hole 22 from the flat surface portion 20a side, and the tip portion protrudes to the arcuate surface 20b side. A counterbore surface 23 is formed around the hole 22 on the arcuate surface 20b of the movable blade body 20, and a snap ring having a larger diameter than the hole 22 in a groove (not shown) is formed at the tip of the shaft portion 13. A retaining member 24 is attached.

As shown in FIG. 2, the movable blade body 20 has an end portion on the side where the hole 22 is formed as a curved surface 25 orthogonal to the flat surface portion 20a. The curved surface 25 is formed concentrically with the center of the hole 22.
In the curved surface 25, an edge portion 25a that is continuous in a plane parallel to the flat surface portion 20a and projects to the outer peripheral side is formed on the flat surface portion 20a side. The edge portion 25a meshes with the groove 12m.

    As shown in FIG. 3B, the flat portion 20a of the movable blade body 20 is formed with a recess 26 having a certain depth in a direction orthogonal to the surface of the flat portion 20a. The concave portion 26 has a stopper surface 26 a orthogonal to the flat surface portion 20 a on the side facing the hole 22. Here, as shown in FIG. 4A, a state in which the central axis of the movable blade body 20 is parallel to the central axis of the excavation tool body 10, that is, the flat portion 20 a of the movable blade body 20 is In a state where the arcuate surface 20b of the movable blade 20 is continuously located on the outer peripheral surface of the excavating tool body 10 so as to overlap the flat surface portion 12a (hereinafter, this state is referred to as a reduced diameter state), the stopper surface 26a is The stopper surface 14a of the convex portion 14 of the excavation tool body 10 is opposed to each other in parallel with a gap.

    As shown in FIGS. 4 and 5, such a movable blade body 20 can swing in a plane along the plane portion 20 a around the hole 22 through which the shaft portion 13 is passed. 4C, the movable blade 20 swings in a direction in which the stopper surface 26a of the concave portion 26 of the movable blade 20 and the stopper surface 14a of the convex portion 14 of the excavating tool body 10 approach each other. In this case (hereinafter, this state is referred to as a diameter-expanded state), the swing angle is regulated by the stopper surface 26a hitting the stopper surface 14a.

As shown in FIG. 1, the distal end surface 10S of the excavation tool body 10 and the distal end surface 20S of the movable blade body 20 are formed so as to have the following configuration in the reduced diameter state. That is, the distal end surface 10S of the excavation tool main body 10 and the distal end surface 20S of the movable blade body 20 are circular on the inner peripheral side thereof, and the gauge portion 4 that is annularly disposed on the outer peripheral side of the inner portion 5. It is comprised so that.
The inner portion 5 is configured by planes 17 and 27 that are formed on the distal end surface 10S of the excavating tool body 10 and the distal end surface 20S of the movable blade body 20 and are perpendicular to the axis O.
The gauge portion 4 is configured by forming inclined surfaces 18 and 28 inclined toward the rear end side in the axis O direction from the inner circumference side toward the outer circumference side at equal intervals in the circumferential direction around the axis O. Has been.

Chips 3 are implanted on the flat surfaces 17 and 27 constituting the inner portion 5 and the inclined surfaces 18 and 28 constituting the gauge portion 4, which are respectively referred to as a gauge tip 3 </ b> A and an inner tip 3 </ b> B.
Here, inclined surfaces 18 and 18 are formed on one side and the other side of the tip surface 10S of the excavating tool body 10 with the plane 17 interposed therebetween, and one inner chip 3B is provided on the plane 17 so that the inclined surface is provided. One gauge chip 3 </ b> A is also provided for each of 18 and 18.
Two inclined surfaces 28, 28 are formed on the outer peripheral side of the flat surface 27 on the front end surface 20 </ b> S of each movable blade body 20, and one inner chip 3 </ b> B is provided on the flat surface 27. Also, one gauge chip 3A is provided for each.

    The tip 3 has the same shape as the gauge tip 3A and the inner tip 3B. In this embodiment, the tip 3 is a button type having a convex surface such as a substantially hemispherical tip, and the base end is cylindrical. The base end portion is embedded in a hole formed in the excavation tool body 10 and is fixed by press-fitting or shrink fitting so that only the distal end portion protrudes from the distal end surface of the excavation tool body 10. . The tip 3 may be of a spike type with a tip of a cone having a spherical tip or a shell shape.

    Further, blow holes 6 are formed from the bottom of the mounting screw hole 2 toward the front end side, and these blow holes 6 are respectively opened in the inner portion 5 of the front end surface.

    The excavation tool 1 as described above is attached to the tip of a rod extending from a rock drill, and in the state shown in FIGS. 4 (a) and 4 (b) It is inserted into the hole 100. Here, the inner diameter of the pilot hole 100 is set slightly larger than the outer diameter of the excavation tool 1.

Then, when reaching the position where the diameter of the pilot hole 100 should be increased, the rod is rotated around its axis by a rock drill. The rotation direction at this time coincides with the offset direction of the hole 22 with respect to the center in the width direction of each movable blade body 20 (in the direction of arrow A in FIG. 4B).
Then, the excavation tool 1 rotates around the axis O. When the excavation tool 1 starts to rotate, as shown in FIGS. 4C, 4D, and 5, the movable blade body 20 pivotally supported by the shaft portion 13 starts to rotate from the rotation stopped state. Due to the inertial force sometimes generated and the centrifugal force due to rotation, the tip end side is swung out to the outer peripheral side around the hole 22 in which the shaft portion 13 is inserted.
When the tip end side of the movable blade body 20 is swung out to the outer peripheral side, the inclined surface 28 located on the rear side in the rotation direction protrudes toward the outer peripheral side and hits the inner peripheral surface 100a of the lower hole 100. Then, friction occurs between the gauge tip 3 </ b> A on the inclined surface 28 and the inner peripheral surface 100 a of the lower hole 100. Due to this friction, the rotational speed of the movable blade body 20 temporarily decreases with respect to the excavation tool body 10, and the movable blade body 20 is pulled backward in the rotation direction with respect to the excavation tool body 10. As a result, the movable blade body 20 is further swung out to the outer peripheral side to be in a diameter expanded state.
Thereby, the diameter of the pilot hole 100 can be expanded.

    In order to shift from the expanded diameter state to the reduced diameter state, the excavation tool 1 may be rotated in the opposite direction or the excavation tool 1 may be retracted.

According to the configuration described above, when the excavating tool 1 is rotated, the movable blade body 20 is first swung out by inertial force or centrifugal force, and the tip of the gauge tip 3A and the inner peripheral surface 100a of the lower hole 100 are The movable blade body 20 can be further protruded to the outer peripheral side due to the friction generated between the two, and the diameter can be increased.
Thereby, the diameter of the pilot hole 100 can be easily expanded even if it is the intermediate part and peripheral edge part.
At this time, since the movable blade body 20 does not require a mechanism for swinging the movable blade body 20, a simple and low-cost configuration can be achieved.

(Other embodiments)
The excavation tool of the present invention is not limited to the above-described embodiments described with reference to the drawings, and various modifications are conceivable within the technical scope.
For example, the shaft portion 13 is provided offset to one side in the width direction with respect to the center in the width direction of the plane portion 12a (the direction orthogonal to the axis O), but the shaft portion 13 is provided in the width direction of the plane portion 12a. It can also be set as the structure provided on the center.
Moreover, in the said embodiment, although the two movable blade bodies 20 are provided, it is not restricted to this, You may provide one piece or 3 pieces or more.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

DESCRIPTION OF SYMBOLS 1 Excavation tool 1a Front-end | tip part 1b Rear-end part 3 Tip 3A Gauge tip 3B Inner tip 4 Gauge part 5 Inner part 6 Blow hole 10 Excavation tool main body 10S Front end surface 11 Cylindrical part 11a Outer surface 12 Plate-like part 12a Plane part 12b Wall Part 13 Shaft part 14 Convex part 14a Stopper surface 14a Convex part 17, 27 Plane 18, 28 Inclined surface 20 Movable blade body 20a Plane part 20b Arcuate surface 20S Tip surface 22 Hole 25 Curved surface 25a Edge part 26 Concave part 26a Stopper surface 100 Pilot hole 100a Inner peripheral surface

Claims (2)

An excavation tool main body, and a movable blade body swingably provided on the excavation tool main body,
When the excavation tool body is rotated around its axis, the movable blade body swings around its rear end side, and the tip end side of the movable blade body protrudes to the outer peripheral side, thereby expanding the hole to be excavated. A drilling tool,
The distal end surface of the excavation tool main body and the distal end surface of the movable blade body in a reduced diameter state, an inner portion that is circular on the inner peripheral side thereof, and a gauge portion that is annularly disposed on the outer peripheral side of the inner portion , Have
In the gauge portion, an inclined surface is formed that is inclined so as to go to the rear end side in the axial direction as it goes from the inner peripheral side to the outer peripheral side.
A chip is implanted in the inclined surface constituting the gauge part ,
The excavation tool main body is disposed on the rear end side and has a columnar portion having a columnar shape, and a plate-like portion having a pair of plane portions formed on the front end side and parallel to each other across the axis. Have
The movable blade body is provided on both sides of the excavation tool main body, and is rotatably connected to a shaft portion provided on the flat portion of the excavation tool main body. It is provided so that it can swing in the plane,
The flat portion of the plate-like portion is formed with a convex portion having a certain height in a direction perpendicular to the surface of the flat portion, and the movable blade body is opposed to the flat portion of the plate-like portion. A concave portion having a certain depth is formed in the plane portion of the movable blade body in a direction perpendicular to the surface of the plane portion, and the convex portion and the concave portion abut against each other. An excavation tool characterized in that a stopper for regulating the swing angle of the movable blade body is provided . 2. The excavation tool according to claim 1 , wherein the shaft portion is provided to be offset to one side of the plane portion with the axis line interposed therebetween.

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