JPS633113B2 - - Google Patents

Description

[Detailed Description of the Invention] <Field of Industrial Application> The present invention relates to a small-diameter hole-expanding bit for drilling a small hole with an enlarged tip when driving anchors, lock bolts, etc. in shoring work or tunnel construction. It is something.

<Prior art> A conventional hole expanding bit is constructed by providing a rotary tube body with wings that can be opened and closed, and attaching the bit to the wings, so that when the hole diameter is to be enlarged, the wings are opened to drill. is common.

Furthermore, in Japanese Utility Model Publication No. 44-3463, a plurality of cones are arranged in a circle from the head body, a drilling blade is protruded from the tip of each cone, and a tapered part is provided on the inner surface of the tip. A drilling drill is described which includes a drill body formed therein and a metal guide piece having a frusto-conical shape and having a circular flange that fits into the tip of the drill body.

<Problems to be Solved by the Invention> However, the general hole expansion bit described above has a complicated and bulky internal structure for opening and closing the wings.
It could not be used for small diameter holes.

In addition, the drilling drill described in Publication of Utility Model Publication No. 44-3463 drills an ordinary straight hole to a predetermined depth, then pulls out the drill, inserts a guiding metal piece into the hole, and then drills again. Since it is necessary to insert and excavate, the work is complicated and has the drawback of requiring a great deal of effort and time.

<Means for Solving the Problems> The present invention was developed in view of the above, and includes an outer tube having an outer tube bit at the tip, and a tube inserted into the outer tube so as to be movable in the length direction and having a bit at the tip. The common structure is that the outer tube has a double tube structure consisting of an inner tube and an inner tube, and the distal end portion of the outer tube is vertically divided to form a plurality of outer tube division parts.

In addition to the above-described common configuration, the first invention includes forming an outer tube convex portion having an inclined surface on the inner surface of the outer tube divided portion, having an inclined surface on the outer surface of the inner tube, and providing the outer tube with an inclined surface. An inner tube recess that can fit into the tube protrusion is formed.

In addition to the above-described common configuration, the second invention further provides an outer tube notch formed on the side edge of the outer tube division part, and an outer tube that can be fitted into the outer tube notch on the outer surface of the inner tube. Provide a protruding support part.

In addition to the above-described common configuration, the third invention further provides a third aspect of the present invention, in which the ends of the outer tube support member, which can be bent in the middle of the length, are rotatably attached to adjacent outer tube division parts, respectively. A stopper is provided on the outer surface of the inner tube to protrude and come into contact with the connecting portion of the outer tube support member.

<Operation> In the first invention, when the inner tube and the outer tube are rotated integrally with the outer tube protrusion and the inner tube recess fitted together, a normal straight hole can be excavated. When the outer tube and the inner tube are moved relative to each other in the length direction and the outer tube convex part and the inner tube concave part are shifted, the wedge action between the inclined surface of the outer tube convex part and the inclined surface of the inner tube causes the outer tube to The tube dividing portion and outer tube bit protrude outward. Therefore, if the inner tube and outer tube are rotated integrally in this state, the excavation diameter will increase.

Further, in the second invention, when the inner tube and the outer tube are rotated together with the outer tube support part fitted into the outer tube notch, a normal straight hole can be drilled. When the outer tube and the inner tube are moved relative to each other in the length direction and the outer tube support section is moved toward the distal end side of the outer tube notch, the outer tube dividing section and the outer tube bit protrude outward. Therefore, if the inner tube and outer tube are rotated integrally in this state, the excavation diameter will increase.

Further, in the third invention, when the outer tube and the inner tube are rotated integrally with the outer tube support member bent, a normal straight hole can be drilled.
When the outer tube and the inner tube are moved relative to each other in the longitudinal direction, the connecting part of the outer tube support member comes into contact with the stopper, so the included angle of the outer tube support member increases, and this causes the outer tube division part and The outer tube bit protrudes outward. Therefore, if the inner tube and outer tube are rotated integrally in this state, the excavation diameter will increase.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

As shown in FIG. 1, the small-diameter hole expanding bit according to the present invention has a double-tube structure in which an inner tube 3 is inserted into a hollow outer tube 4 so as to be movable in the length direction.

The outer tube 4 has a plurality of circular hole-shaped outer tube crack prevention parts 7 at its tip, and is vertically divided from each outer tube crack prevention part 7 toward the tip to form a plurality of outer tube division parts 8. An outer tube bit 5 is firmly fixed to the tip of the outer tube divided portion with a bolt 21, and an outer tube convex portion 6 having an inclined surface is formed on the inner surface. In the embodiment of the outer tube 4 shown in the drawings, the distal end portion is divided into two outer tube division parts 8, 8. Also,
As shown in FIG. 1, the inclined surface of the outer tube convex portion 6 approaches the central axis of the outer tube 4 as it goes from the upper end side (right side in FIG. 1) to the tip side (left side in FIG. 1). is inclined to.

The inner tube 3 inserted into the outer tube 4 has a bit 1 at the tip.
... are provided radially, and the outer tube convex portions 6 described above are provided on the outer surface.
The outer tube recess 2 is formed into an outer tube recess 2 into which the outer tube protrusion 6 can fit. Note that the excavation diameter after hole expansion is determined by the shape and position of the outer tube convex portion 6 and the inner tube concave portion 2. Therefore, the shape and position of the outer tube protrusion 6 and the inner tube recess 2 are set in consideration of the ground and the diameter of the hole to be excavated.

Next, the structure of the swivel section will be explained.

The outer tube 4 and the inner tube 3 have approximately the same length, and the fourteenth
As shown in FIG. 15, the top of the outer tube 4 is connected to the swivel pipe 16, and the top of the inner tube 3 is connected to the inner tube connection part 19. Swivel pipe 1
6 is the swivel case 1 via the threaded pipe 13
7 is connected. Further, the inner tube connecting portion 19 is similarly connected to the swivel case 17. and,
A water swivel 14 is provided at the rear of the swivel case 17.
Water entering from the suction port 9 of the swivel case 17 is discharged through the inner pipe 3 to the bit 1, and slime and muddy water is discharged from the gap between the outer pipe 4 and the inner pipe 3 through the hole of the swivel pipe 16. 15 discharge ports 10.

In addition, the above-mentioned outer tube 4, inner tube 3, swivel pipe 13, swivel case 17, inner tube connection part 19
rotate as one. Further, FIG. 16 shows a device for shifting the outer tube 4 normally attached to a rotary boring machine.

In either case, when the threaded pipe 13 is rotated clockwise, a female thread is formed inside the threaded pipe 13, and the male thread formed on the swivel pipe 16 and the male thread formed on the swivel case 17 are opposite threads. Therefore, when the threaded pipe 13 is rotated once, the swivel pipe 16 and the swivel case 17 move closer to each other by a length corresponding to two pitches. A slide key 11 is formed inside the swivel pipe 16, and the slide key 11 is engaged with a slide key on the outside of the inner tube connecting portion 19.

In addition, in FIGS. 14 and 15, 18 indicates a shunt rod.

Next, the operating method will be explained.

Normally, when drilling a straight hole, the inner tube 3 and the outer tube 4 are rotated integrally with the outer tube protrusion and the inner tube recess fitted together. After excavating to the specified depth,
The rotation of the inner tube 3 and outer tube 4 is stopped, and the threaded pipe 13
and rotate the lever 20. When the threaded pipe 13 is rotated, the outer tube 4 moves upward due to the action of the screw cut inside. Note that the outer tube 4 does not rotate together with the threaded pipe 13 due to the action of the slide key 11 of the inner tube connecting portion 19. As the outer tube 4 moves upward, as shown in FIG. The outer tube bit 5 at the tip is also pushed outward as a result. Therefore, by rotating the outer tube 4 and the inner tube 3 together in this state, it is possible to excavate a hole with a larger inner diameter than a straight hole. In this way, by turning the lever 20, the outer tube 4 is gradually raised, and the outer tube convex part 6 is placed in the inner tube concave part.
When the outer pipe bit 5 reaches the outer diameter portion of the inner pipe 3, the outer pipe bit 5 reaches its maximum excavation diameter. In order to drill a hole in the rock, it is necessary to press the solid rock hole wall with an extremely strong force, but the threaded pipe 13 uses the same action as a screw jack to forcefully raise the outer pipe 4 and further push the outer pipe 4 upward. This is reinforced by the wedge action between the tube convex portion 6 and the inner tube recess 2, so that the diameter of the outer tube bit 5 is expanded very strongly. Therefore, according to the present invention, a sufficient hole can be drilled even in hard rock.

In addition, when drilling a straight hole, if there is a risk that the outer tube division parts 8, 8 will open beyond the outer diameter of the outer tube 4, as shown in FIG.
8 and excavate. This metal band 28
is made of thin metal, and when the outer tube division parts 8, 8 are expanded in diameter by lifting the outer tube 4, they are cut by this diameter expansion force. Therefore, there is no problem in drilling for hole expansion.

Next, the small diameter hole expanding bit shown in FIGS. 17 to 24 will be explained.

This small diameter hole expanding bit has an outer tube bit 5 at the tip.
It has a double-tube structure consisting of an outer tube 4 having an inner tube 4 and an inner tube 3 which is inserted into the outer tube 4 so as to be movable in the length direction and has a bit 1 at the tip. A plurality of outer tube division parts 8, 8 are formed by dividing the outer tube division parts 8, 8, and a substantially oval outer tube notch 24 is formed on the opposing side edges of the outer tube division parts 8, 8, and an outer tube cutout 24 is formed on the outer surface of the inner tube 3. is formed by projecting outer tube support portions 22, 22 that can be fitted into the outer tube notches 24, 24. Outer tube notch 2
4 is generally oval in shape and has an edge that slopes towards the tip. The outer tube support portion 22 has a spring 23
This is to allow the outer tube support portion 22 to be accommodated in the inner tube 3 when the inner tube 3 and the bit 1 are pulled out with the outer tube 4 intact. be.

When drilling a normal straight hole with the small-diameter hole expanding bit constructed as described above, as shown in FIG. The outer tube 4 is rotated integrally. After excavating to a predetermined depth, the outer tube 4 is raised. When the outer tube 4 is raised, the outer tube support part 22 comes into contact with the inclined edge of the outer tube notch 24, and when the outer tube 4 is further raised, the outer tube support part 22 comes into contact with the adjacent outer tube as shown in FIG. It is sandwiched between the opposing side edges of the divided portions 8, 8, and as a result, the outer tube divided portions 8, 8 are bent around the outer tube crack preventing portion 7, and the interval between the outer tube bits 5, 5 is expanded. Therefore, in this state, the inner pipe 3
By rotating the outer tube 4 and the outer tube 4 together, a hole can be drilled.

Next, the small diameter hole expanding bit shown in FIGS. 25 to 27 will be explained.

This small-diameter hole expansion bit is for use on soft ground such as soil and sand, and has an outer tube 4 with an outer tube bit 5 at the tip.
and an inner tube 3 which is inserted into the outer tube 4 so as to be movable in the length direction and has a bit 1 at its tip. The lever-shaped outer tube supporting members 25, 25 are rotatably connected by a pin 26', and the end of one outer tube supporting member 25 is connected to one outer tube dividing portion 8, 8. 8 with a pin 26, and the end of the other outer tube support member 25 is rotatably attached with a pin 26 to the other outer tube divided portion 8, so that the outer surface of the inner tube 3 A stopper 2 is provided at a position where the connecting portions of the outer tube support members 25, 25 come into contact.
7 is installed protrudingly. The outer tube support members 25, 25 connected by the pins 26' are bendable in the middle of their lengths, and when the included angle between the outer tube support members 25, 25 is reduced, the outer tube division parts 8, 8 are brought closer together. , when the above-mentioned included angle is increased, the outer tube division parts 8, 8 are separated from each other by a large distance.

Therefore, when drilling a normal straight hole with the small-diameter hole-expanding bit configured as described above, the outer tube 4 and the inner tube 3 are integrally connected with the outer tube support members 25, 25 bent. Rotate and dig. and,
After excavating to a predetermined depth, when the outer tube 4 is raised, the connecting portion of the support members 25, 25 is moved to the stopper 27.
comes into contact with. Further, when the outer tube 4 is raised, the included angle of the support members 25, 25 increases, so that each outer tube divided portion 8 bends outward significantly, and each outer tube bit 5 protrudes outward to a large extent. Therefore, if the outer tube 4 and the inner tube 3 are rotated integrally in this state, a large enlarged hole can be excavated.

Note that this small-diameter hole expanding bit can be used for considerably large hole expanding work because the diameter expansion rate of the outer pipe bits 5, 5 is large.

In addition, the above-mentioned figures 1, 17, and 25
In the illustrated embodiment, the inner tube 3 is replaced by the outer tube 4.
It can be pulled out regardless of whether it is inserted or not. this is,
This is to use the outer tube 4 as a casing and push the PC steel wire for the anchor into the inside of the outer tube 4.

In the above-described embodiment, the distal end portion of the outer tube 4 is vertically divided into two outer tube division parts 8, 8, but the present invention is not limited to this. That's fine.

<Effects of the Invention> As explained above, according to the present invention, the structure is extremely simple and the diameter expansion force is strong, so a small hole with an enlarged tip can be drilled even in a strong place such as rock. be able to.

Further, in the present invention, after drilling a normal straight hole to a predetermined depth, the hole diameter can be enlarged and excavated simply by relatively moving the inner tube and the outer tube in the length direction. Therefore, the efficiency of excavation work can be significantly improved.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a sectional view of a small-diameter hole expanding bit according to the first invention, FIG. 2 is a side view of the bit in a reduced diameter state, and FIG. 4 is a partially cutaway side view, 5 is a side view rotated 90 degrees from the state shown in 2, and 6 is a side view.
The figure is a front view of the bit, Figure 7 is a cross-sectional view taken along line A-A' in Figure 1, Figure 8 is a cross-sectional view taken along line B-B', and Figure 9 is a cross-sectional view taken along line C-C'. Cross-sectional view along the line, No. 10
The figure is a front view of the bit with the diameter expanded, Figure 11 is a sectional view taken along line A-A' in Figure 12, Figure 12 is a sectional view of the bit with the diameter expanded, and Figure 13 is the bit with the diameter expanded. 14 is a sectional view of the swivel head of the percussion type excavator, FIG. 15 is a side view of the swivel head shown in FIG. 17 and 18 are side views of a small-diameter hole expanding bit according to the second invention, FIG. 19 is a sectional view, FIG. 20 is a front view in a reduced diameter state, and FIG. A sectional view taken along the line A-A', FIG. 22 is a side view in the expanded diameter state, and FIG. 23 is a front view in the expanded diameter state.
Figure 24 is a sectional view taken along line A-A' in Figure 22;
FIG. 25 is a side view of a small diameter hole expanding bit according to the third invention in an expanded state, FIG. 26 is a front view of the small diameter hole expanding bit in an expanded state, and FIG. 27 is A of FIG. 25.
- It is a sectional view along the A' line. In the figure, 1 is a bit, 2 is an inner tube recess, 3 is an inner tube,
4 is an outer tube, 5 is an outer tube bit, 6 is an outer tube convex part, 7 is an outer tube crack prevention part, 8 is an outer tube dividing part, 9 is an inlet,
10 is a discharge port, 11 is a slide key, 13 is a threaded pipe, 14 is a water swivel, 17 is a swivel case, 18 is a shank rod, 19 is an inner tube connection part, 20 is a lever, 21 is a bolt, 22 is an outer tube support part, 23 is a spring, 24 is an outer tube notch,
25 is an outer tube support member, 26 is a pin, 27 is a stopper, and 28 is a metal band.

Claims (1)

[Scope of Claims] 1 A double tube structure consisting of an outer tube having an outer tube bit at the tip, and an inner tube inserted into the outer tube so as to be movable in the length direction and having a bit at the tip, The distal end portion of the tube is vertically divided to form a plurality of outer tube divided portions, and an outer tube convex portion having an inclined surface is formed on the inner surface of the outer tube divided portion, and an inclined surface is formed on the outer surface of the inner tube. The outer tube convex portion and the inner tube concave portion rotate together in a fitted state during normal drilling, and the outer tube concave portion is fitted with the outer tube convex portion and rotates as a unit during drilling. A small-diameter hole expanding bit characterized by shifting the tube convex part and the inner tube concave part and rotating the outer tube part and the outer tube bit integrally with the outer tube part and the outer tube bit projecting outward to increase the excavation diameter. 2 A double tube structure consisting of an outer tube with an outer tube bit at the tip, and an inner tube that is inserted into the outer tube so as to be movable in the length direction and has a bit at the tip. A plurality of outer tube division parts are formed by dividing the outer tube, and an outer tube notch is formed on the side edge of the outer tube division part, and an outer tube support that can be fitted into the outer tube notch is provided on the outer surface of the inner tube. During normal excavation, the outer tube support portion is fitted into the outer tube notch and rotates as a unit, and when drilling to expand the hole, the outer tube support portion is moved to the tip side of the outer tube notch. A small-diameter hole expanding bit characterized in that the outer tube dividing portion and the outer tube bit are rotated integrally in an outwardly extending state to increase the drilling diameter. 3 A double tube structure consisting of an outer tube with an outer tube bit at the tip, and an inner tube that is inserted into the outer tube so as to be movable in the length direction and has a bit at the tip. A plurality of outer tube divisions are formed by dividing the outer tube, and the ends of the outer tube support member, which can be bent midway along the length, are rotatably attached to the adjacent outer tube divisions, and the inner tube A stopper that can come into contact with the connection part of the outer tube support member is protruded on the outer surface of the hole. Normally, during excavation, the outer tube and inner tube are rotated together with the outer tube support member bent, and the hole is expanded. During excavation, by moving the outer tube and the inner tube relatively in the length direction, the connection part of the outer tube support member is brought into contact with the stopper, and the outer tube division part and the outer tube bit are extended outward. A small diameter hole expanding bit that rotates integrally to increase the drilling diameter.