JP3085815B2 - Cutter head for shield excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutter head for a shield excavator mounted on a front face of a face of a shield excavator.

[0002]

2. Description of the Related Art FIG. 6 shows a front view of a cutter head of a general shield excavator, FIG. 7 shows VII-VII of FIG. 6, and FIGS.
FIG. 1 schematically shows a conventional cutter bit.

A shield excavator excavates the ground by rotating a cutter head mounted on a front face portion, forms a segment on a tunnel inner wall formed by the excavation, and takes a reaction force from the segment. The excavator can be moved forward by a shield jack. As shown in FIG. 6, in the cutter head 11, three cutter spokes 14 are attached to the cutter face 12 radially from the rotation shaft 13. Each cutter spoke 14 is provided with a plurality of forward rotation cutter bits 15 and reverse rotation cutter bits 16. Also,
The cutter face 12 is provided with slits 17 located on both sides of each of the cut spokes 14 to discharge excavated earth and sand by the cutter bits 15 and 16.

That is, a plurality of cutter bits 15 for normal rotation are attached to the cut-spoke 14 in the forward rotation direction F, and a plurality of cutter bits 16 for reverse rotation in the reverse rotation direction B of the cut-spoke 14. Attached side by side and corresponding to the cutter bit 15 for normal rotation. FIG.
As shown in FIG. 5, the cutter spoke 14 has a rectangular cylindrical shape, and the cutter bits 15 and 16 are fixed to the cutter spoke 14 by fixing bolts 18. As shown in FIG. 8, the cutter bits 15 and 16 are attached to the tip of a cutter bit body 21 formed of a shank material.
2, a super hard tip 23 is attached. The super hard tip 23 is formed mainly of tungsten carbide or the like for excavating earth and sand. 24 is a mounting hole.

In the cutter head 11 configured as described above, when the rotating shaft 13 rotates forward (in the direction of arrow F in FIGS. 6 and 7) and the cutter bits 15 and 16 attached to the respective cut spokes 14 rotate, Cutter bit 15
Chip 23 excavates the face 26 and a new face 27
Is formed. The excavated earth and sand 28 generated at this time enters the slit 17 and is discharged.

[0006]

However, in the conventional cutter head described above, the cutter head 11 not only rotates, but is also given a forward propulsive force by a shield excavator. The earth is excavated with the cutter bit 15 while propelling upward. Therefore, the face 27 is formed to be inclined by the predetermined angle θ with respect to the vertical plane 29 orthogonal to the direction of propulsion of the cutter head 11 (shield excavator). for that reason,
As shown in FIG. 6, since the mounting height of the forward rotation cutter bit 15 and the reverse rotation cutter bit 16 is the same, the reverse rotation cutter bit 16 which is not used is compared with the forward rotation cutter bit 15 for excavating earth and sand. Means that the back surface is constantly pressed against the face 27.

[0008] Then, as shown in FIG. 8, when the earth and sand of the face face 27 is pressed against the back surface of the cutter bit 16, the part is worn out and cut off to form a space 30, and the chip 23 falls off. There was a problem of doing it. Therefore, as shown in FIG. 9, a reinforcing overlay 31 is formed on the back surface of the cutter bit 16, and as shown in FIG.
There has been proposed a reinforcing bit 32 formed on the back surface of the cutter bit 16 in a W-shape. But,
Both of them are insufficient as reinforcement, and in long-term use, as shown in FIGS. 8 and 9, the back surface is hollowed out to form a space portion 30, and the same problem as described above occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a cutter head for a shield excavator in which the excavated soil is prevented from being pressed against the back surface of a cutter bit to improve durability. Aim.

[0009]

According to the present invention, there is provided a cutter head for a shield excavator according to the present invention, wherein a spoke is radially mounted on a front face of a face of the shield excavator from a rotation axis thereof, In a cutter head for a shield excavator in which forward and reverse cutter bits are attached to the front and rear sides in the rotation direction in the rotation direction, a predetermined clearance angle with respect to a cutting direction is provided at least on the back surface of the reverse cutter bit. An excavated earth and sand cutting blade having the following characteristics is formed.

[0010]

[Function] The excavated earth and sand cutting blade is formed on the back side of the reverse rotation cutter bit, so that when excavating the soil with the forward rotation cutter bit accompanying the propulsion of the shield excavator, the excavated soil contacting the rear side of the reverse rotation cutter bit is reduced. It is excavated and removed by the cutting blade, and wear of the back surface of the reversing cutter bit is prevented.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 schematically shows a cutter bit representing a cutter head for a shield excavator according to a first embodiment of the present invention, and FIG.
FIG. 1 shows a cross section taken along line II-II of FIG.

In the cutter head for a shield excavator according to the present embodiment, an excavated earth and sand cutting blade having a predetermined clearance angle with respect to the cutting direction is formed at least on the back surface of the reverse rotation cutter bit. That is, as shown in FIGS. 1 and 2, in the cutter bit 41 for reverse rotation, a super hard tip 44 is attached by a brazing agent 43 to a tip end of a cutter bit body 42 formed of a shank material. The super hard tip 44 is formed mainly of tungsten carbide or the like for excavating earth and sand. In addition,
Reference numeral 45 denotes a mounting hole for a cutter head (not shown).

An excavated earth and sand cutting blade having a predetermined clearance angle with respect to the cutting direction of the cutter head is formed on the back surface of the cutter bit 41. That is, a hardened overlaid portion 46 having a triangular shape in plan view is formed adjacent to the tip 44 on the back surface of the cutter bit 41, and the end face of the overlaid portion 46 opposite to the tip 44 is excavated. The earth and sand cutting blade 47 is provided. This excavated earth and sand cutting blade 4
7 is formed at an angle α with respect to the cutting direction F of the cutter head, has a thickness T, and is formed at an angle β with respect to the back surface of the cutter bit 41.

Accordingly, when a forward rotation cutter bit (not shown) excavates earth and sand, the face of the earth and sand presses against the back surface of the reverse rotation cutter bit 41. At this time, the excavated earth and sand is excavated by the excavated earth and sand cutting blade 47 formed on the back of the cutter bit 41, and is removed on both sides of the cutter bit 41 as shown by arrows in FIG. There is no wear.

FIG. 3 schematically shows a cutter bit representing a cutter head for a shield excavator according to a second embodiment of the present invention. As shown in FIG. 3, in the cutter bit 51 of the present embodiment, a super hard tip 54 is attached to the distal end of the cutter bit main body 52 by a brazing agent 53, and the base end of the cutter bit main body 52 is A mounting hole 55 for a cutter head (not shown) is formed. On the back surface of the cutter bit 51, a pair of overlaid portions 56 each having a shape of a letter in a plan view are formed, and the overlaid portions 56 serve as excavated earth and sand cutting blades. This excavated earth and sand cutting blade 57
Is formed at an angle α with respect to the cutting direction F by the cutter head, and has a thickness T and an angle β with respect to the back surface of the cutter bit 51, as described above.

Therefore, the earth and sand pressed against the back surface of the cutter bit 51 during earth and sand excavation is excavated by the pair of excavated earth and sand cutting blades 56 and is removed to both sides of the cutter bit 51 as shown by arrows in FIG.

FIG. 4 is a plan view of a cutter bit representing a cutter head for a shield excavator according to a third embodiment of the present invention, and FIG.
FIG. 4 shows a VV cross section of FIG. As shown in FIGS. 4 and 5, in the cutter bit 61 of the present embodiment, a super-hard tip 64 is attached to the tip of the cutter bit body 62 by a brazing agent 63,
A mounting hole 65 for a not-shown cutter head is formed at the base end of the cutter head. A concave portion 66 is formed on the back surface of the cutter bit 61, and a super hard chip 68 having a triangular shape in a plan view is attached to the concave portion 66 by a brazing agent 67. Is the excavated earth and sand cutting blade. This excavated earth and sand cutting blade 68
As described above, it is formed at an angle α with respect to the cutting direction F by the cutter head, has a thickness T, and is formed at an angle β with respect to the back surface of the cutter bit 61.

Therefore, the earth and sand pressed against the back surface of the cutter bit 61 during earth and sand excavation is excavated by the pair of excavated earth and sand cutting blades 68 and is removed on both sides of the cutter bit 61 as shown by arrows in FIG.

In the above-described embodiment, the excavated earth and sand cutting blade is formed by inclining at an angle α to the right and left sides from the center of the cutter bit main body. It is a good thing. Further, the method of forming the excavated earth and sand cutting blade is not limited to hardfacing or chip embedding, and other methods may be used. Further, in this embodiment, the excavated earth and sand cutting blade is formed on the back surface of the cutter bit for reverse rotation, but may be formed on the back surface of the cutter bit for normal rotation.

[0021]

As described in detail above with reference to the embodiments, according to the cutter head of the shield excavator of the present invention,
Cutter bits for normal rotation and reverse rotation are attached to the spokes on the front face of the face of the shield excavator at the front and rear sides in the rotation direction, and at least the back of the reverse rotation cutter bit has an excavated earth and sand cutting blade having a predetermined clearance angle with respect to the cutting direction. When excavating earth and sand with the forward cutter bit accompanying the propulsion of the shield excavator, the excavated earth and sand that comes into contact with the back of the reverse cutter bit is excavated by the cutting blade and eliminated, and the rear of this reverse cutter bit is removed. Wear is prevented and durability can be improved. In addition, since the abrasion of the back surface of the reverse rotation cutter bit is prevented, the excavation speed of the shield excavator can be increased and the work efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cutter bit representing a cutter head for a shield excavator according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of a cutter bit representing a cutter head for a shield excavator according to a second embodiment of the present invention.

FIG. 4 is a plan view of a cutter bit representing a cutter head for a shield excavator according to a third embodiment of the present invention.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a front view of a cutter head of a general shield excavator.

FIG. 7 is a VII-VII diagram of FIG. 6;

FIG. 8 is a perspective view of a conventional cutter bit.

FIG. 9 is a perspective view of a conventional cutter bit.

FIG. 10 is a perspective view of a conventional cutter bit.

[Explanation of symbols]

 41, 51, 61 cutter bit 42, 52, 62 cutter bit body 44, 54, 64 tip 47, 56, 57, 68 excavated earth and sand cutting blade

Claims (1)

(57) [Claims] 1. A front face of a shield excavator is provided with spokes radially extending from a rotation axis thereof, and forward and rearward cutter bits for forward and reverse rotation are attached to the front and rear sides of the spokes in the rotation direction. In a cutter head for shield excavator, a cutter head for shield excavator characterized in that at least a back surface of the reverse cutter bit is formed with an excavated earth and sand cutting blade having a predetermined clearance angle with respect to a cutting direction.