JPH11196610A - Digging tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digging tool suitable for digging a shrubbery or wasteland and cutting the root of tree, etc., to reclaim the land to a tilled field, for removing an antipersonnel mine, etc., and having a base reusable simply by exchanging an abraded bit in the case of bit abrasion. SOLUTION: This digging tool comprises a holder 5 fixed to a forcedly rotated cylindrical base and a bit 7 fixed to the holder 5 by a fixing means. The bit 7 has a fitting groove for the holder 5 at the base part, the holder 5 is provided with a plate part to be fit into the fitting groove and thick-walled supporting parts integrally attached to the front and rear sides of the plate part and the plate part is formed to have low front part and high rear part relative to the rotational direction of the base supporting the holder. The front supporting part 12 is formed to be lower than the rear supporting part 13 and the fitting groove of the bit is formed in such a manner as to be shallow at the front side and deep at the rear part relative to the rotating direction corresponding to the form of the plate part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to excavating shrub forests and wasteland, cutting tree roots and the like, and clearing and cultivating the land.
The present invention relates to a drilling tool suitable for use in removing antipersonnel mines.

[0002]

2. Description of the Related Art A plurality of rows of bit mounting portions are provided on an outer peripheral portion of a cylindrical base provided with rotating mechanisms at both ends in an axial direction.
An excavator in which a plurality of bits are attached to each row by a fixing method such as welding has been put to practical use. This bit has been hardened and hardened, or has a hard blade such as a carbide tip fixed to the blade of a steel shank by brazing or the like. Those having a cutting edge are often insufficient in the hardness of the cutting edge, and are often worn out in a short time and cannot be used. In the case where the hard blade body is fixed to the blade edge portion, the life of the blade edge portion is prolonged, but there is a problem that the shank portion is often worn and cannot be used.

[0003]

In the above conventional apparatus, when a bit fixed to a cylindrical base by welding or the like is worn, it is difficult to replace the bit, and the entire apparatus becomes unusable. It was economic. Therefore, an object of the present invention is to improve the problem in the above-mentioned excavator and to make it possible to reuse the base only by replacing the worn bit, even if the bit is worn.

[0004]

In order to solve the above problems, the present invention employs the following configuration. That is, the drilling tool according to the present invention is a drilling tool comprising a holder fixed to a cylindrical body that is forcibly rotated, and a bit fixed to the holder by a fixing unit, and the base of the bit is A fitting groove for the holder is formed, and the holder is provided with a plate-like portion into which the fitting groove fits, and a thick supporting portion integrally provided on the front side and the rear side of the plate-like portion. The plate-shaped portion is formed such that the front side in the rotation direction of the base supporting the holder is low and the rear side is high, and the front support portion is formed lower than the rear support portion, and the bit is fitted. The mating groove is characterized in that the groove is formed shallow on the front side in the rotation direction and deep on the rear side in correspondence with the plate-shaped portion.

[0005]

Operation and effect of the invention The holder is fixed to the base by welding or the like,
Attach a bit to the holder. The attachment of the bit is performed by fitting the fitting groove of the bit into the plate-like portion of the holder and fixing the both by fixing means. The load received by the bit during excavation is supported by the plate-like portion of the holder, the support portion, the fixing means, and the like. During excavation, the front portion of the holder in the rotating direction comes into contact with the object to be excavated, so the front portion of the holder and the bit are mainly worn. Since the height of the front support portion of the exposed portion of the holder is small and the exposed area is small, wear of the holder due to excavation is small, and the bit is mainly worn. If the bit is worn and cannot be used anymore, the bit may be removed and replaced with a new bit. The bit itself is a consumable and its price is relatively low,
Although attaching and detaching the holder fixed to the base is troublesome and costly, the tool of the present invention is economical because the holder and the base can be used repeatedly even if the bit is worn.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of the present invention.

The excavating tool 1 comprises holders 5 fixed to a cylindrical base 2 of a rotary excavator, and bits 7 individually attached to the holders. The base 2 is
As shown in FIG. 6, the rotating devices 1 are provided at both left and right ends in the axial direction.
0 and 10 are provided, and during the excavation, the rotary device is forcibly rotated in a predetermined direction.

The holder 5 has a base 5a having an arc-shaped bottom surface fixed to the base 2 by welding. The upper portion of the holder 5 has a substantially triangular shape in a side view, and thick supporting portions 12 and 13 are provided on the front side and the rear side in the rotation direction, respectively.
The middle part between them is a thin plate-like part 15. The height of the front support portion 12 is considerably lower than the height of the rear support portion 13, and the upper surface of the front support portion 12 is formed as an inclined surface 12a having a lower front side, and is continuously connected thereto. The upper surface 15a of the plate-shaped portion 15 is also formed as an inclined surface having a low front side. The front support 1
Hardened buildup layers 17 are formed on both left and right edge portions of No. 2.

At a position near the lower part of the plate-like portion 15 of the holder 5, a through hole 19 penetrating left and right is provided. This through hole 19 is a bolt hole for fixing the bit. Further, support surfaces 12b and 13b perpendicular to the plate portion are provided on the back surface of the front support portion 12 and the front surface of the rear support portion, respectively.

The bit 7 is formed by fixing a blade 23 of a carbide tip to the front upper end of a steel shank 21 by brazing.
A fitting groove 25 is cut upward from the bottom surface of the base of the shank portion 21. Both side portions of the fitting groove 25 are leg portions 21a and 21b. The fitting groove 25 is shallow on the front side and deeply cut on the rear side, and has a shape corresponding to the plate-like portion 15 of the holder in a side view. The base of the shank 21 is provided with the legs 21a, 21a.
A hole 27 for bolt attachment that penetrates b is provided. Of the holes 27, one of the legs 21 with the fitting groove interposed therebetween.
The part formed on the a side is the head 30a of the bolt 30.
Is a dish-shaped portion 27a in which the screw is embedded, and the screw is not cut. Also, the leg 2 on the opposite side with respect to the fitting groove 25
The hole portion provided in 1b is a screw hole 27b into which the bolt 30 is screwed.

The bit 7 has a standard type (a), a type for soft ground (b), a type for gravel (c) and the like as shown in FIG. 3, and the shape of the blade is slightly different. The shape is the same. The bolt 30 as a fixing means for fixing the bit 7 to the holder 5 is a hexagon socket head bolt having a dish-shaped head. As the fixing means, bolts of other shapes, screws, etc. can be used, but if they protrude from the side of the bit, they will be rapidly worn during excavation. It is preferable that the head does not protrude from the side of the bit in the fixed state.

The excavating tool 1 is used by fixing holders 5,... To an outer peripheral portion of a cylindrical base body 2 in an appropriate arrangement.
It is preferable that the holders 5,... Are usually arranged in a row at appropriate intervals on a plurality of lines along the axial direction of the base 2. In this case, it is effective to arrange the holders of the adjacent holder rows in a staggered shape in a plan view by shifting the positions in the front-back direction in the horizontal direction. The arrangement of the holder is not limited to this, but may be any as long as effective excavation is performed over a wide range by rotation of the base.

Bits 7,... Are respectively attached to holders 5,. This attachment is performed by fitting the plate-like portion 15 of the holder into the fitting groove 25 of the bit, and screwing a bolt 30 serving as a fixing means through the plate-like portion 15 through both the leg portions 21a and 21b of the bit. Done. The attachment and detachment of this bit is easy.

When a large number of bits 7,... Are mounted on the outer periphery of the base 2, the base is mounted on an arm 41 of a crawler type traveling device (or a wheel type traveling device) 40 as shown in FIG. In a pressed state (in some cases, it may be simply placed), the rotating devices 10 and 10 using a hydraulic motor as a driving source are forcibly rotated in a predetermined direction.
By this rotation, the excavation is performed by the bits 7, while the base 2 rolls in a predetermined direction. Since the hard blade 23 is planted at the tip of the bit, excavation can be performed well even if there is a tree root or a stone. Most of the force acting on the bit during excavation is supported by a contact portion between the inclined surface 15a of the plate-like portion 15 of the holder and the inclined surface 25b of the fitting groove 25 of the bit. The traveling device 40 in the illustrated example is one in which the base 2 with the cover 43 is attached instead of the excavator of the hydraulic shovel, and thus it is convenient to use the existing traveling device.

In this excavating tool 1, the bit 7 is
The height (B) of the portion (supporting portion 12) on the front side in the rotation direction of the base 2 in the exposed portion of the holder is low, and the height (A) of the front exposed surface of the bit 7 is small. ) Is high, the bit 7 is worn exclusively during use, and the holder 5 is less worn. Therefore, when a bit is worn, it can be reused by replacing only the bit.

When the excavator is used for removing antipersonnel land mines, it is preferable from a safety viewpoint that the excavator can be advanced on the target ground by remote control or the like. Further, in the above description, the case where the holder is used by attaching to the cylindrical base 2 is exemplified, but the shape of the base is not limited to this, and the holder can be used by attaching to a base of another shape. .

[Brief description of the drawings]

FIG. 1 is a perspective view in an assembled state showing a specific example of the present invention.

FIG. 2 is a perspective view of the disassembled state.

FIG. 3 is a perspective view showing types of bits.

4A is a front view, FIG. 4B is a side view, and FIG. 4C is a rear view in an assembled state.

5A is a plan view showing the arrangement of bits, and FIG.

FIG. 6 is (a) a front view and (b) a side view of the excavator.

FIG. 7 is an explanatory diagram of usage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drilling tool 2 Base 5 Holder 7 Bit 10 Rotating device 12 Front support part 13 Rear support part 15 Plate part 21 Shank part 25 Fitting groove 30 Bolt (fixing means)

Claims (1)

[Claims] An excavating tool comprising a holder fixed to a cylindrical body that is forcibly rotated and a bit fixed to the holder by fixing means, wherein a fitting groove for the holder is formed at a base of the bit. The holder is provided with a plate-shaped portion in which the fitting groove is fitted, and a thick supporting portion integrally provided on a front side and a rear side of the plate-shaped portion, respectively. The front side in the rotation direction of the base supporting the holder is formed lower and the rear side is formed higher, and the front support portion is formed lower than the rear support portion,
The excavating tool is characterized in that the fitting groove of the bit is formed so as to be shallow on the front side in the rotation direction and deep on the rear side in correspondence with the plate-shaped portion.