JP4622117B2 - Bit for shield excavator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bit for a shield excavator, and in particular, prevents the main tip from falling off by preventing back wear of the bit body.
[0002]
[Prior art]
Conventionally, the shield excavator generally performs forward and reverse rotation, and therefore, on the side where the rotation direction is reversed, since the rear excavation is performed, the flank steel shank is severely worn away. When this wear progresses, the carbide tip cannot be held and the carbide tip falls off.
[0003]
For this reason, the shield bit disclosed in Japanese Utility Model Publication Nos. 59-14897 and 60-19199 is obtained by inserting an auxiliary chip into a groove provided behind the main chip.
[0004]
Further, the shield bit disclosed in Japanese Utility Model Laid-Open No. 3-50690 is provided so that plate-like chips are brought into contact with both sides of the main chip.
[0005]
On the other hand, the 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 the main chip is exemplified.
[0006]
[Problems to be solved by the invention]
However, the shield bit in which the main chip and the auxiliary chip are separated has a drawback that the separated area is worn.
[0007]
In addition, the shield bit in which the plate-shaped chip is brought into contact with the main chip has a drawback that the plate-shaped chip has to support the excavation resistance of the main chip and is lost due to brazing distortion acting on each other.
[0008]
In addition, the mining cutter bit with the insert inserted in the rear of the main tip is in the forward rotation direction, has no concept of back wear due to back excavation, and the entire clearance surface of the bit body corresponding to the cutting edge ridge length of the main tip Wear is not planned.
[0009]
For this reason, in the present invention, in order to solve the above-described problems, the configuration of the auxiliary tip is improved to prevent the back wear of the bit body and the dropout of the main tip.
[0010]
[Means for Solving the Problems]
The present invention has been made in view of the above points. The main tip provided at one end of the bit body is formed with a rake face and a flank for excavation, and the flank formed on the main tip. This is an improvement on the premise of a shield excavator bit that is provided with an auxiliary tip on the end side.
[0011]
That is, the auxiliary chip is provided in a two-surface constrained chip seat formed so as to extend the flank of the main chip in the width direction. In this auxiliary chip, the protruding end formed on the main chip side is at a position higher than at least the extending direction line of the flank formed on the main chip, and is at a position lower than the 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 having a height relationship.
[0012]
In the present invention, it is preferable that the auxiliary chip is composed of a plurality of divided chips from the viewpoint of brazing distortion or the like.
Furthermore, the present invention can also be applied to double-ended bits in which the main chip and the auxiliary chip are respectively provided at both ends of the bit body.
[00013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the shield excavator bit according to the present invention will be described below with reference to the drawings.
[0014]
1 and 2 show a shield excavator bit 1 according to the present invention. The bit 1 includes a shield excavator (not shown) in which a bit body 2 rotates forward and backward as shown in FIG. For example, a cutter face plate (not shown) provided on the spoke 3 is attached by welding or the like, and the formation 4 is excavated by rotating the shield excavator in the direction of the arrow.
[0015]
A main chip 5 made of a cemented carbide that constitutes the rake face 5a and the flank face 5b for excavation is brazed to one end of the bit body 2 as the shield excavator rotates.
[0016]
In addition, an auxiliary tip 6 having a strip shape made of cemented carbide is provided on the terminal side of the flank 5b formed on the main tip 5 in consideration of prevention of back surface wear. In this case, the auxiliary chip 6 is brazed in the chip seat 7 formed so as to extend the inclined flank 5b of the main chip 5 substantially in the width direction. The chip seat 7 restrains the strip-shaped auxiliary chip 6 on both 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 with respect to the main chip 5. The auxiliary chip 6 is composed of three divided chips in the illustrated case. This is a consideration to disperse the brazing distortion and prevent the auxiliary chip 5 from cracking and to increase the attachment strength.
[0017]
Further, the auxiliary chip 6 has a protruding end 8 formed on the terminal side of the main chip 5, and this protruding end 8 extends in the extending direction of the flank 5 b of the main chip 5 as clearly shown in FIG. 4. It is at a position higher than the line 9 and at a low position with respect to the tip 10 of the main chip 5 so as to have a level difference t. As a result, when viewed from the side of the bit body 2, the auxiliary chip 6 has a two-peak configuration having a height relationship between the tip of the main chip 5 and the protruding end 8. As described above, this prevents back wear due to the presence of the auxiliary tip 6, and in normal excavation, the protruding end 8 constitutes a secondary cutting blade having a rake face 6a and a flank face 6b. At the same time, the digging waste flowing out from the main chip 5 is discharged so as to get over the protruding end 8 of the auxiliary chip 6.
[0018]
In FIG. 4, a gap c is formed between the main chip 5 and the auxiliary chip 6. However, the gap c may be close to zero as long as it is not affected by the brazing strength.
[0019]
FIGS. 5 (a) to 5 (c) show a modified example of the shield excavator bit 1 of the present invention. FIG. 5 (a) shows the flank 6b of the auxiliary tip 6 with the tip seat 7 deepened. In FIG. 5B, the rear wall 7 b is formed at an obtuse angle with respect to the bottom surface 9 a of the chip seat 9. 5 (c), the seat surface 7a of the tip seat 7 is shallow, so that most of the auxiliary tip 6 is positioned higher than the extension direction line 9 of the flank 5b of the main tip 5. Is.
[0020]
6 and 7 show a shield excavator bit 1 according to another embodiment. The same reference numerals are given to the same parts, and the main chip 5 and the auxiliary chip 6 are arranged at both ends of the bit body 2. This is applied to a so-called double-ended bit that is provided in each part.
[0021]
Also in this double-ended bit, the auxiliary chip 6 is provided in the chip seat 7 of two-face restraint, and a protruding end 8 is formed on the terminal side of the main chip 5. Further, the auxiliary chip 6 has a two-peak configuration in which there is a height relationship between the tip 10 of the main chip 5 and the protruding end 8.
[0022]
8 and 9 show a shield machine bit 1 showing a modified example of a double-ended bit, in particular, the specifications relating to the end length and height in the width direction of the bit body 2 are changed, and shield drilling is performed. It depends on the model of the machine.
[0023]
Although the auxiliary chip 6 is clearly shown in FIG. 8, a protruding end 8 formed of a two-step inclined rake face 5 a is provided on the terminal side of the main chip 5.
[0024]
【The invention's effect】
In the present invention, as described above, the auxiliary chip 6 is provided in the chip seat 7 which is constrained with respect to the main chip 5 provided in the bit body 2, and the auxiliary chip 6 includes the main chip 5. A protruding end 8 having a height relationship with respect to the tip 10 of the main chip 5 is formed on the end side of the main chip 5.
[0025]
Accordingly, the presence of the auxiliary tip 6 prevents back bit wear of the bit body 2 even when back excavation due to forward / reverse rotation, and there is no reduction in the back metal effect on the main tip 5, so one work area is continued. It has the advantage that it can be used.
[0026]
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a shield excavator bit according to the present invention.
FIG. 2 is a plan view with respect to FIG. 1;
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.
FIG. 5 is a front view showing modified examples of the shield excavator bit according to the present invention in FIGS. 5 (a) to 5 (c) with respect to the auxiliary tip mounting structure.
FIG. 6 is a front view showing another embodiment of the shield excavator bit of the present invention.
7 is a plan view with respect to FIG. 6. FIG.
FIG. 8 is a front view showing another embodiment of the shield excavator bit of the present invention.
9 is a plan view with respect to FIG. 8. FIG.
[Explanation of symbols]
1 Bit for shield excavator 2 Bit body 3 Spoke 4 Formation 5 Main chip
5a Rake face
5b Flank 6 Auxiliary tip
6a Rake face
6b Flank 7 Tip seat
7a Bottom
7b Rear wall 8 Projection end 9 Extension direction line
10 Tip

Claims (2)

The main tip provided at one end of the bit body is formed with a rake face and flank for excavation, and an auxiliary tip is provided on the end side of the flank formed on the main tip. In the shield excavator bit,
Said auxiliary chip flank of the main chip with provided in the tip seat of the two-face restraint formed to substantially extend in the width direction, butt Extension end is formed in the main chip side of the auxiliary chips And
This projecting end is at a position higher than at least the extension direction line of the flank of the main chip, and is at a low position with respect to the tip of the main chip. It has a two mountain structure ,
The auxiliary excavator bit is constituted by a plurality of divided chips in the width direction . The shield excavator bit according to claim 1 , wherein the main tip and the auxiliary tip are provided at both ends of the bit body, respectively.

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