JP4734735B2 - Bi-directional drilling bit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bidirectional excavation bit attached to a shield excavator that rotates forward and reverse, and more particularly, an excavation action is made to function by a crushing blade tip even on an inclined surface side of a bit body.
[0002]
[Prior art]
Conventionally, this type of bidirectional excavation bit 21 is attached to a spoke 24 of an excavator 23 having a central drilling blade 22 as shown in FIG. In order to prevent wear of the inclined surfaces 26 formed on both sides of the center chip 25, the bidirectional excavation bit 21 is disclosed in, for example, Japanese Utility Model Publication No. 7-550, a first super drill bit provided in the center of the bit body. The thing which provided the 2nd carbide | carbonized_material chip | tip on the both-sides slope of a hard chip | tip is disclosed.
[0003]
[Problems to be solved by the invention]
However, although the bidirectional drill bit disclosed in the above-mentioned publication can prevent wear of the bit body due to the presence of the second cemented carbide tip, development of a bidirectional drill bit having a more effective drilling function is desired at the drilling site. Has been.
[0004]
For this reason, in the present invention, the crushing blade tip is provided on the inclined surface of the bit body, so that it can function positively for excavation work.
[0005]
[Means for Solving the Problems]
The present invention has been made in view of the above-described points. In the longitudinal direction of the block-shaped bit body, a central chip made of cemented carbide is provided, and inclined surfaces are provided on both sides of the central chip. It is an improvement on the premise of the bidirectional drill bit that is to be provided.
[0006]
That is, the bidirectional excavation bit of the present invention is such that the inclined surface is provided with a plurality of crushing blade tips made of cemented carbide with at least wedge-shaped projections protruding in the direction of dividing the central tip. . This is expected for excavation work where slits can be made in the formation by crushing blade tips and gravel can be crushed.
[0007]
The crushing blade tip is applied when the central tip is divided in a substantially right angle direction and arranged in a single row in the longitudinal direction of the bit body, or in a staggered manner in the longitudinal direction of the bit body. The
[0008]
In the case of crushing blade tips arranged in a zigzag state, an empty space on the inclined surface on the opposite side of the crushing blade tip may be provided with an auxiliary tip for preventing wear.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the bidirectional drill bit according to the present invention will be described with reference to the drawings.
[0010]
1 to 3 show a bi-directional excavation bit 1 of the present invention. In a steel bit main body 2 having a block shape, a central chip 3 made of cemented carbide is attached to a mounting groove 4 extending in the center in the longitudinal direction. It is prepared in a state of being divided within.
[0011]
Further, on the inclined surfaces 5 formed on both sides of the center chip 3, a crushing blade chip 7 made of a cemented carbide, in which a wedge-shaped projection 6 is projected in a direction in which the center chip 3 is divided, is provided with an attachment groove 8. It is provided within. In the illustrated case, the crushing blade tips 7 divide the central tip 3 in a substantially right angle direction, and are provided in three in the longitudinal direction of the bit body 2, and are arranged in a row with respect to the longitudinal direction.
[0012]
Further, the central chip 3 has an inclined surface 3a that is continuous in the same plane with respect to the inclined surface 5 of the bit body 2, and these inclined surfaces 3a, 5 are rake surfaces for excavation accompanying forward and reverse rotation of the excavator 23. Form.
[0013]
Further, the center chip 3 is provided in the mounting groove 4 as described above, and is usually fixed by brazing. As for the shape of the mounting groove 4, FIG. 3 shows a case with parallel side surfaces, FIG. 4 (a) shows an obtuse V bottom surface, and FIG. 4 (b) shows a right V bottom surface. Yes.
[0014]
5 to 7 show a modification of the bidirectional excavation bit 1 according to the present invention, in which a pair of inclined surfaces 8 are formed at one end in the longitudinal direction.
[0015]
In the bidirectional excavation bit 1 of the present invention configured as described above, the bit body 2 is attached by welding or the like to the spokes 24 of the excavator 23 as shown in FIG. In this case, FIG. 8 is an enlarged plan view of a part of the excavator 23 shown in FIG. 17 described in the prior art, and the spoke 24 has the bidirectional excavation bit 1 of the present invention on the outermost peripheral side and the inner side thereof. It is intended to be installed.
[0016]
9 to 11 show a bi-directional excavation bit 1 according to another embodiment of the present invention, in which four crushing blade tips 7 divide the central tip 3 in a right angle direction and the longitudinal direction of the bit body 2. The direction is a staggered arrangement. This is a consideration for making the excavation work effective by changing the arrangement of the crushing blade tips 7.
[0017]
12 to 15 show a bidirectional excavation bit 1 showing still another embodiment of the present invention. In the empty space on the inclined surface 5 on the opposite side of the crushing chips 7 arranged in a staggered pattern, An auxiliary tip 9 for preventing the inclined surface 5 from being worn is provided. In this case, the auxiliary tip 9 is directly brazed to the inclined surface 5 of the bit body 2, and the tip portion 10 is formed at the end on the central tip 3 side. This pointed portion 10 takes into account the discharge due to overcoming excavated debris.
[0018]
Further, FIGS. 16 (a) and 16 (b) are cross-sectional views taken along the line AA ′ in FIG. 13, and show a modification corresponding to FIG. FIG. 16 (a) shows a chip seat 11 that receives the auxiliary chip 9, in which the inclined surface 9a of the auxiliary chip 9 is flush with the inclined surface 5 of the bit body 2. FIG. . FIG. 16B shows the tip seat 11 formed on the inclined surface 5 of the bit body 2 with a stronger inclination. This is also a measure to prevent wear due to back excavation.
[0019]
In the present embodiment, the wedge-shaped protrusion 6 of the crushing blade tip 7 is exemplified as an arc shape, but it is needless to say that the wedge-shaped projection 6 can be changed to other shapes such as a curved shape, a wavy shape, and a polygonal shape.
[0020]
【The invention's effect】
As described above, according to the present invention, the crushing blade tip 7 having the wedge-shaped projections 6 that divide the central tip 3 on the inclined surfaces 5 formed on both sides of the central tip 3 provided in the bit body 2. The bidirectional excavation bit 1 is provided.
[0021]
Therefore, the bidirectional excavation bit 1 of the present invention can be expected to excavate with the crushing blade tip 7 more effectively in addition to the excavation of the central tip 3. In particular, the crushing blade tip 7 functions so that the wedge-shaped projection 6 adds a slit to the formation, so that the formation portion is loosened and the excavation of the central tip 3 functions effectively.
For this reason, the bidirectional excavation bit 1 of the present invention increases the excavation length in an excavator such as a shield, and the back surface wear generated on the inclined surface 5 of the bit body 2 includes the auxiliary tip 9. It has the advantage that it can be prevented more effectively.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a bidirectional drill bit according to the present invention.
FIG. 2 is a plan view with respect to FIG. 1;
FIG. 3 is a side view with respect to FIG. 1;
FIG. 4 is a side view in which the shape of the center chip is changed, and FIG. 4 (a) shows an obtuse angle V-groove and FIG. 4 (b) shows a right-angle V-groove.
FIG. 5 is a front view showing another embodiment of the bidirectional drill bit according to the present invention.
FIG. 6 is a plan view with respect to FIG.
FIG. 7 is a side view with respect to FIG.
FIG. 8 is a partial plan view showing a state where the bidirectional excavation bit of the present invention is attached to the excavator.
FIG. 9 is a front view showing another embodiment of the bidirectional drill bit according to the present invention.
FIG. 10 is a plan view with respect to FIG. 9;
FIG. 11 is a side view with respect to FIG. 9;
FIG. 12 is a front view showing still another embodiment of the bidirectional drill bit according to the present invention.
13 is a plan view corresponding to FIG.
14 is a side view corresponding to FIG.
15 is a cross-sectional view obtained along the line AA ′ in FIG. 13;
16 is a cross-sectional view showing a modified example corresponding to FIG. 15, and in FIG. 16 (a), when the auxiliary chip is positioned on the same plane as the inclined surface of the bit body, FIG. The case where the tip is inclined stronger than the inclined surface of the bit body is shown.
FIG. 17 is a plan view showing a conventional excavator.
[Explanation of symbols]
1 Bidirectional drilling bit 2 Bit body 3 Center tip
3a Inclined surface 4 Mounting groove 5 Inclined surface 6 Wedge projection 7 Crushing blade tip 8 Slope surface 9 Auxiliary tip
10 Pointed part
11 Tip seat

Claims (4)

The bit present body forming the block shape, provided with a central chip made of cemented carbide, yet on both sides of the central chip, in both the drilling bit inclined surface is adapted to be provided respectively,
The inclined surface is provided with a plurality of crushing blade tips made of cemented carbide with wedge-shaped projections protruding so as to cross the center tip in a direction perpendicular to the longitudinal direction of the center tip ,
The two-way excavation bit characterized in that the wedge-shaped projections of the crushing blade protrude above the inclined surface and the central tip toward the excavator traveling direction side on the inclined surface and the central tip . The crushing blades chip, both the drill bit of claim 1, wherein are arranged in a row state in the longitudinal direction of the bit body. The crushing blades chip, both the drill bit of claim 1, wherein are arranged in a staggered state in the longitudinal direction of the bit body.   The bidirectional excavation bit according to claim 3, wherein an auxiliary tip for preventing wear is provided in an empty space on an inclined surface opposite to the crushing blade tip arranged in a staggered state.

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