JP2002242592A - Bit for shield machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bit for a shield machine, which is prevented from rear surface abrasion. SOLUTION: The bit 1 for the shield machine includes a main tip 5 on one end or both ends of a bit main body 2, and a strip-like auxiliary tip 6 having a projecting edge 8 formed on a rear end side of a flank 5b formed on the main tip 5. The auxiliary tip 6 is welded in a two-side limited tip seat 7 formed by extending the flank 5b of the main tip 5 in a width direction, and the projecting edge 8 is located on the rear end side of the main tip 5. The projecting edge 8 is arranged at a location at least higher than an extension 9 of the flank 5b of the main tip 5 and lower than a front end 10 of the main tip 5. The front end 10 of the main tip 5 and the projecting edge 8 of the auxiliary tip 6 form a two-ridge structure with different heights as viewed in a plan view.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bit for a shielded excavator, and more particularly to a bit for a back excavation of a bit body to prevent a main chip from falling off.

[0002]

2. Description of the Related Art Conventionally, since a shield excavator generally performs forward and reverse rotations, a vigorous digging of a steel shank on a flank surface is performed on the side where the rotation direction is reversed because backside excavation is performed. Exhibits wear. When the wear progresses, the cemented carbide tip cannot be held, and the cemented carbide tip comes off.

[0003] For this reason, the shield bit disclosed in Japanese Utility Model Laid-Open No. 59-14897 and Japanese Utility Model Publication No. 60-19199 has an auxiliary chip inserted into a groove provided behind a main chip. .

The shield bit disclosed in Japanese Utility Model Laid-Open No. 3-50690 is provided so that plate-shaped chips are brought into contact with both sides of a main chip.

On the other hand, a long-wall type mining cutter bit disclosed in Japanese Patent Application Laid-Open No. 59-72397 is mounted on a rotating drum, but an example in which an additional insert is provided behind a main chip is exemplified. I have.

[0006]

However, the shield bit in which the main chip and the auxiliary chip are separated from each other has a disadvantage that the separated area is worn.

[0007] Further, the shield bit in which the plate-shaped chip is brought into contact with the main chip has a disadvantage that the plate-shaped chip must support the excavation resistance of the main chip, and breakage occurs because brazing strain acts on each other. there were.

Further, the mining cutter bit in which the insert is implanted behind the main tip is of a forward rotation direction, has no concept of back wear due to back excavation, and has a bit body corresponding to the cutting edge ridge length of the main tip. Wear is not planned for the entire flank.

In view of the above, in the present invention, in order to solve the above-mentioned problems, the configuration of the auxiliary tip is improved to prevent the wear of the back face of the bit body and the falling off of the main tip. .

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a rake face and a flank for excavation are formed on a main chip provided at one end of a bit body.
Moreover, at the end of the flank formed on this main chip,
This is an improvement on the premise of a shield excavator bit provided with an auxiliary tip.

That is, the auxiliary chip is provided in a two-sided chip seat formed so as to extend the flank of the main chip in the width direction. And this auxiliary tip,
The protruding end formed on the main chip side is at a position higher than at least an extension direction of a flank formed on the main chip, and is lower than a tip of the main chip. As a result, when viewed from the front, the main chip and the auxiliary chip have a two-peak configuration in a height relationship.

Further, in the present invention, it is preferable that the auxiliary chip is constituted by a plurality of divided chips from the viewpoint of brazing distortion and the like. Further, the present invention can be applied to a double-ended bit provided at both ends of the bit body, the main chip and the auxiliary chip.

[00013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a shield excavator bit according to an embodiment of the present invention.

FIGS. 1 and 2 show a bit 1 for a shield excavator according to the present invention. The bit 1 has a bit body 2 that rotates forward and backward as shown in FIG. For example, it is attached to a spoke 3 of a cutter face plate (not shown) provided on the cutter face plate (not shown) by welding or the like,
The formation 4 is excavated by the shield excavator rotating in the direction of the arrow.

The one end of the bit body 2 is provided with a main chip 5 made of a cemented carbide which forms a rake face 5a and a flank 5b for excavation with the rotation of the shield excavator.
Is brazed.

The flank formed on the main chip 5
On the end side of 5b, there is provided an auxiliary tip 6 in the form of a strip made of cemented carbide in consideration of prevention of back wear. In this case, the auxiliary chip 6 is brazed in the chip seat 7 formed so that the inclined flank 5b of the main chip 5 is substantially extended in the width direction. The chip seat 7 restrains the rectangular auxiliary chip 6 on two sides by the bottom surface 5a and the rear wall 5b so as not to reduce the back metal effect of the bit body 2 on the main chip 5. The auxiliary chip 6 is composed of three divided chips in the illustrated case. This is to disperse the brazing distortion to prevent the auxiliary chip 5 from cracking and to increase the mounting strength.

Further, the auxiliary chip 6 has a protruding end 8 formed on the terminal end side of the main chip 5, and this protruding end 8 is formed on the flank 5b of the main chip 5 as clearly shown in FIG. Of the main chip 5 at a position higher than the extension direction line 9
10 is located at a lower position so as to have a step amount t.
As a result, when viewed from the side of the bit body 2, the auxiliary chip 6 has a two-peak configuration in which the tip and the protruding end 8 of the main chip 5 have a height relationship. This is because, as described above, the presence of the auxiliary tip 6 prevents the back surface from being worn, and in the case of excavation in the normal direction, the protruding end 8 becomes the rake face.
While forming a secondary cutting edge formed with the flank 6a and the flank 6b, excavation chips flowing out of the main chip 5 are discharged so as to get over the projecting end 8 of the auxiliary chip 6.

In FIG. 4, a gap c is formed between the main chip 5 and the auxiliary chip 6, but this gap c is so close to zero as to be free from the influence of brazing strength. Is also good.

FIGS. 5 (a) to 5 (c) show a modification of the bit 1 for a shield excavator according to the present invention. FIG. FIG. 5B shows a bottom surface 9a of the tip seat 9 in which the inclination angle of the flank 6b is increased.
The rear wall 7b is formed at an obtuse angle with respect to the rear wall 7b.
FIG. 5 (c) shows that the seat surface 7a of the chip seat 7 is shallow, and most of the auxiliary chip 6
In a position higher than the extension direction line 9 of FIG.

FIG. 6 and FIG. 7 show a shield excavator bit 1 showing another embodiment. The same parts are denoted by the same reference numerals. The present invention is applied to a so-called double-ended bit which is provided at both ends of the second bit.

Also in this double-ended bit, the auxiliary chip 6 is provided in a two-sided chip seat 7, and a protruding end 8 is formed on the end side of the main chip 5. The auxiliary chip 6 has a two-peak configuration in which the tip 10 of the main chip 5 and the protruding end 8 have a height relationship.

FIGS. 8 and 9 show a shield machine bit 1 showing a modified example of a double-ended bit, in which the specifications regarding the end length and height of the bit body 2 in the width direction are changed. It depends on the type of shield excavator.

It should be noted that the auxiliary chip 6 is clearly shown in FIG.
A protruding end 8 formed at 5a is provided.

[0024]

As described above, according to the present invention, the main chip 5 provided on the bit body 2 is
Are provided in a two-sided restraint chip seat 7, and the auxiliary chip 6 has a protruding end 8 formed at the terminal end side of the main chip 5 with respect to the tip 10 of the main chip 5. It was made.

Therefore, even if there is back excavation due to forward and reverse rotation due to the presence of the auxiliary tip 6, the bit body 2
This has the advantage that one working section can be used continuously since the back wear of the main chip 5 is prevented and the back metal effect on the main chip 5 is not reduced.

[0026]

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a bit for a shield excavator according to the present invention.

FIG. 2 is a plan view corresponding to FIG.

FIG. 3 is an explanatory view showing a state where a bit for a shield excavator of the present invention is attached to a spoke of a cutter face plate.

FIG. 4 is an explanatory diagram showing an arrangement relationship between a main chip and an auxiliary chip.

5 (a) to 5 (c) are front views showing modified examples of the shield excavator bit of the present invention with respect to the mounting structure of the auxiliary tip.

FIG. 6 is a front view showing another embodiment of the bit for a shield excavator of the present invention.

FIG. 7 is a plan view corresponding to FIG. 6;

FIG. 8 is a front view showing another embodiment of the bit for a shield excavator of the present invention.

FIG. 9 is a plan view corresponding to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bit for shield excavator 2 Bit body 3 Spoke 4 Formation 5 Main chip 5a Rake surface 5b Relief surface 6 Auxiliary chip 6a Rake surface 6b Relief surface 7 Chip seat 7a Bottom surface 7b Rear wall 8 Protrusion end 9 Extension direction 10 Tip

Claims (3)

[Claims] 1. A digging rake face and a flank are formed on a main tip provided at one end of a bit body, and an auxiliary tip is provided at an end of the flank formed on the main tip. In the shielded excavator bit to be provided, the auxiliary tip is provided in a two-face restrained tip seat formed so as to substantially extend the flank of the main tip in the width direction, and the end of the main tip. On the side, form a protruding end,
This protruding end is at least at a position higher than the extension direction line of the flank of the main chip, and at a lower position with respect to the tip of the main chip, and has a height relationship with the main chip in a front view. A bit for a shield excavator, characterized by having a double mountain configuration. 2. The bit for a shield excavator according to claim 1, wherein the auxiliary chip is constituted by a plurality of divided chips. 3. The shield excavator bit according to claim 1, wherein the main tip and the auxiliary tip are respectively provided at both ends of the bit main body.