JPH03183890A - Excavation bit - Google Patents

Abstract

PURPOSE:To make it possible to prevent excavation hooks from breaking by providing the excavation hooks to hook mounting plates which are provided radially, and providing circular excavation hook protective plates in positions approximately corresponding to a rotation locus of the peripheral side of the excavation hooks between the hook mounting plates. CONSTITUTION:In an excavation bit provided at the end of a rotary shaft, excavation hooks 7... and 7A... are respectively mounted on a plurality of hook mounting plates 10 which are provided radially. After that, circular excavation hook protective plates 3 and 3 are provided in positions approximately corresponding to a rotation locus of the peripheral side of the excavation hooks 7... and 7A... between the hook mounting plates 10. According to the constitution, the protruding of a bedrock against the excavation hooks 7... and 7A... is prevented, and the breaking of the excavation hooks 7... and 7A... can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a drilling bit suitable for drilling hard rock.

(Conventional technology) The inventor is J1! ! As a drilling bit for board drilling.

We are developing what is shown in Figures 4 and 5.

In Figures 4 and 5, 5 is an excavator (not shown)
a cylindrical rotating shaft rotated by, 6 inserting the rotating shaft;
This is a casing that is inserted into a vertical hole or a horizontal hole to be excavated, and these are generally configured in an interlocking manner.In the zero-rotary shaft 5, a shaft having screw blades may be provided concentrically with the rotary shaft 5. be.

A ring 8 is fixed to the tip of the rotating shaft 5, and the ring 8 is in sliding contact with the inner circumferential surface of the casing 6 via a bearing (not shown). 9 is a cylindrical shaft at the center of the tip of the rotating shaft 5, 1O1
11 is a board for mounting three excavating claws radially between the rotary shaft 5 and the cylindrical shaft 9 by welding, and one plate 10 is a drilling claw 7 for excavating the inside of the casing 6. The other mounting plate 11 is provided with an excavating claw 7A for excavating a portion extending to the outside of the casing 6.
Provided for installation.

One of the blocks 12 is attached to the plate 10 by welding, and several claws are attached to each block 12.

The digging claw 7 has a mounting groove 7b on the inner surface, and the mounting groove 7b
b is fitted into the block 12 and removably fixed with a bolt 13.

For the other installation, a bracket 15 is attached to the plate 11 so as to be rotatable about the vertical axis 14, the flock 12 is attached to the bracket 15, the groove 7b of the digging claw 7A is fitted into the flock 12, and the bolt 13 is attached. By fixing the excavating claw 7A at an angle, the excavating claw 7A is attached at an angle in the same manner as described above.

The digging claw 7A is opened and closed between the position indicated by the solid line e and the position indicated by the two-dot chain line d.

(Problem to be solved by the invention) However, as shown in Fig. 6, when burying a water pipe with this excavation bit on its side (in this case, the casing 6 becomes a water pipe and is not left underground). ), the drilling bit reaches the hard rock l, a crack 2 occurs in a part of the rock at the top of the horizontal hole being excavated by the drilling claw 7, and a part of the rock IA
If the excavating pawl 7 collides with a part of the rock mass IA due to its displacement and protrusion due to its own weight into the rotating path of the excavating pawl, there is a problem that the excavating pawl 7 will break.

SUMMARY OF THE INVENTION In view of these problems, an object of the present invention is to provide an excavation bit with a structure that allows excavation without breaking the excavation claw even when excavating hard rock.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a drilling bit provided at the tip of a rotating shaft. is characterized in that an arc-shaped excavation claw protection plate is provided between the plates at a position that substantially coincides with the rotation locus of the outer peripheral side of the excavation claw.

(Function) Since the excavation bit of the present invention has the above-described structure, the arc-shaped excavation pawl protection plate prevents the rock from protruding toward the inner circumference and hitting the excavation pawl on the inner circumference.

(Embodiment) Fig. 1 is a front view showing an embodiment of the drilling bit according to the present invention, Fig. 2 is a partially sectional side view thereof, and Fig. 3 is a side view showing a state in which a horizontal hole is being excavated. In Figures 1 to 3,
The same reference numerals as in FIGS. 4 to 6 indicate the same components.

The drilling claw is attached to the plate io by the ring 8 at the tip of the cylindrical rotating shaft 5.
and the central cylindrical shaft 9, and each mounting has three digging claws 7 at the same radial position of the plate 10, as shown in FIGS. 4 and 5. It is installed in the same structure as shown. Reference numeral 3 designates excavation pawl protection plates, and each protection plate 3 is provided corresponding to the excavation pawl 7 of each stage, and both ends are attached to the plate IO by welding or bolting. This protection plate 3 is located at a location that substantially matches the rotation locus on the outer peripheral side of the digging claw 7. Further, the tip of each protection plate 3 is located at a position slightly retreating from the tip of each digging claw 7.

Each attachment is attached to the plate IO, and several claw attachments are either flock 12 or welded at an angle so that it precedes the base or tip excavation part in the rotational direction X during excavation, as shown in Figure 3. It is installed by

Further, the excavating claw 7 has a mounting groove 7b on its inner surface, and the mounting groove 7b is fitted into the block 12 and detachably fixed with a bolt 13. Therefore, the excavating claw 7 is installed such that the center line S of the excavating claw 7 as seen from the side surface is such that the base thereof precedes the tip during excavation rotation. The inclination angle θ of the center line S is set to be greater than 0 degrees, and preferably to 45 degrees or less. More preferably, as shown in FIG.
c is a carbide tip fixed to the excavation part, and the excavation claw 7 is attached so that the carbide tip 7c is attached at any angle suitable for excavation) at the rear in the rotation direction. .

The excavating claw 7A that excavates the outside of the casing 6 is attached as follows. Installation is done using a pair of brackets 16 on the board 10.
．． 17 are welded so that the bracket 17 on the bit tip side is closer to the center of rotation than the bracket 16 on the rotating shaft 5 side, a square guide 18 is installed between these brackets 16 and 17, and a square tube 19 is attached to the square guide 18. Fits slidably,
The digging claw 7A is attached to the square tube 19 by welding the arm 20,
For installation, a block 12 is welded to the arm 20, and the digging claw 7A is detachably attached to the block 12 with a bolt 13.

This excavating claw 7A moves in the direction of the arrow in FIG. 2 along the rectangular tube 19 or the rectangular guide 18 by coming into contact with the excavating surface. ! The excavating claw 7A moves from the iD position to the solid line position and partially protrudes outside the casing 6, making it possible to excavate the outside. On the other hand, when the digging bit is pulled out as shown by arrow B in FIG. It can be moved to the D position inside 6 and can be pulled out.

In this way, if the protective plate 3 of the excavating pawl 7 is provided on the outer circumferential side of each excavating pawl 7 along the rotational circumferential direction, even if a portion of the excavating pawl 7 tries to protrude toward the inside circumference due to cracks in the bedrock or its own weight, it will be protected. Since it is blocked by the plate 3, the digging claw 7 is prevented from breaking due to being pressed against the protruding rock.

Further, the excavating claw 7.7A of this embodiment is attached in an inclined structure as shown in FIG. 3, but this is an inclination in the opposite direction to the conventional one. With conventional inclined structures, when excavating hard rock,
Due to the elasticity of the digging claw and its support, digging of the digging claw,
However, if the slope is in the opposite direction as in this embodiment, the digging claw 7,
7A does not dig in, the elasticity of the digging claw 7.7A causes the digging claw 7.7A to bite into the excavation surface 4 made of hard rock.
Repeated jumps are prevented and smooth excavation is possible.

The excavating claw 7.7A may have an arcuate outer circumferential surface, or may be constructed as described in JP-A-62-189292, JP-A-62
As disclosed in Japanese Patent Publication No. 189292, it is preferable to form it into a twisted shape and attach it. Also, digging claw 7.7
It goes without saying that the structure of mounting A is not limited to the above-mentioned embodiment, and can be modified in various ways. Further, the protection plate 3 may be provided on a support other than the plate 10 to which the digging claws 7 are attached.

(Effects of the Invention) According to the present invention, an arc-shaped protection plate is provided at a position along the rotational trajectory of the outer periphery of the excavation claw, so that the protrusion of the rock toward the excavation claw is prevented, and breakage of the excavation claw is prevented. be done.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the drilling bit according to the present invention, Fig. 2 is a partially sectional side view thereof, Fig. 3 is a side view showing the horizontal hole drilling state, and Fig. 4 is a FIG. 5 is a front view showing a bit that has been developed in the past, FIG. 5 is a side sectional view thereof, and FIG. 6 is a side sectional view illustrating the problem. l: Hard rock, 3: Protective plate, 5: Cylindrical rotating shaft, 6: Casing, 7.7A: Excavation claw, 8: Ring, 9: Cylindrical shaft,
1O: Mounting is on a plate, 12 two-jaw mounting is on a block, 13: Bolt

Claims (1)

[Claims] In the excavation bit installed at the tip of the rotating shaft of the excavator, each excavation pawl is attached to the pawl mounting plates provided radially, and between the pawl installation plates, an arc-shaped A drilling bit characterized by being provided with a drilling claw protection plate.