JP2568152Y2 - Shield machine cutter bit - 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 bit for a shield machine in which a carbide tip is mounted on the tip of a shank material.

[0002]

2. Description of the Related Art FIG. 4 shows a general cutter bit in which a carbide tip 12 is mounted on a shank material 11 by brazing or the like, and the cutter bit moves to the left in FIG. Excavate earth and sand. In addition, C is a rake face (earth and sand excavation face), and D is a flank face (back face). FIG. 5 shows a tip bit type cutter bit in which a cemented carbide tip 14 is inserted and fixed in a groove cut in a shank material 13, and the tip falls off when receiving an impact during excavation such as excavation of a gravel layer. Used to prevent.

[0003] The cutter bit shown in FIG. 6 is composed of a digging surface wear y and a back surface wear x generated when the cutter bit shown in FIG. 4 is used.
In order to prevent wear, abrasion resistant layers 16 and 15 are formed by depositing abrasion resistant material on the rake face C and flank D of the shank material 17, and as the abrasion resistant material, a martensitic weld metal, Tungsten carbide, austenitic 30% Cr cast iron, or the like is used. The cutter bit shown in FIG. 7 has a shank material 19 for preventing the digging surface wear y and the back surface wear x that occur when the cutter bit shown in FIG. 4 is used.
A long carbide tip 21 is brazed to the rake face C, and the carbide tip 20 is brazed to the back face D immediately after the carbide tip 21.

[0004]

The above prior art has the following problems. Form of FIG. 4: The rake face C and the flank D of the shank material 11 are y, x in the figure.
, And the carbide tips 12 fall off due to the progress of wear.

The rake face C and the flank D of the shank material 13 are indicated by y, x in FIG.
, And the carbide tips 14 fall off due to the progress of wear. Form of FIG. 6: The labor and time are required for the deposition of the wear-resistant layers 16 and 15, and the price increases.

Further, since the hardness of the wear-resistant layers 16 and 15 is lower than that of the cemented carbide tip 18, the wear-resistant layers 16 and 15 are worn before the carbide tip 18 due to long-term use. FIG. 7: A step as shown in FIG. 8 is formed at a joint 22 between the rake face side carbide tip 21 and the flank side carbide tip 20, and this step acts to peel off the carbide tip 21.

[0007] In the case of a step in the opposite direction to that of FIG. 8, it acts to peel off the carbide tip 20. In addition, since the carbide tips 20 and 21 are separately brazed to the shank material 19 during manufacture, the shank material 19 is heated twice, which adversely affects the tissue. In the case of brazing the carbide tips 20 and 21 by one heating, the brazing operation becomes busy, and the temperature may decrease, and the quality of the brazing may decrease.

An object of the present invention is to solve the above-mentioned problems in the prior art and to provide a cutter bit having excellent wear resistance.

[0009]

A cemented carbide tip to be brazed to the tip of a shank material has a Λ shape in which a rake face and a flank face are integrally formed.

[0010]

[Function] Since there is no step between the rake face and the flank of the cemented carbide tip, even when the cutter is rotated in the normal or reverse direction, the step is caught by the step so that a force for peeling the cemented carbide tip is not generated. Both the rake face and the flank face of the shank material are covered with carbide tips, and the carbide tips are more excellent in wear resistance than hardfacing with a wear-resistant material, so the wear resistance of the cutter bit is improved. improves.

[0011]

1 and 2, an embodiment of the present invention will be described. In the figure, 1 is a shank material, 2 is a carbide tip, 3
0 is a cut-spoke, 31 and 32 are forward and reverse cutter bits, A is an excavation direction (forward), B is an excavated soil flow, C is a rake face of the cutter bit, and D is a cutter bit. The flank, e is the rake angle of the cutter bit, f is the relief angle of the cutter bit, and α is the angle caused by the lateral movement (rotation of the cutter) and the feed (forward movement of the shield machine) of the cutter bit.

The shank member 1 and the carbide tip 2 are brazed in the same manner as in the prior art, but the two members 1 and 2 are joined by one brazing operation. At the time of excavation of the shield machine, as shown in FIG.
Rake wear caused by the excavated earth flow B
The flank D of the reverse rotation side cutter bit 32 is worn by the back face due to the contact of the face with the earth and sand. Note that the above angle α increases as the excavation speed increases with respect to the rotation speed. FIG. 3 shows another embodiment of the present invention in which a carbide tip 2a is mounted on a shank material 1a.

In any of the embodiments, the cutter bit of the present invention has abrasion because the tip of the cutter bit where rake wear and back surface wear are large, and both the rake face and the flank face are covered with carbide tips. The occurrence of occurrence is extremely small.

[0014]

[Effect of the Invention] The cutter bit of the shield machine according to the present invention is a cutter bit in which a carbide tip is attached to the tip of a shank material, and the carbide tip has a Λ shape in which a rake face and a flank are integrally formed. Has the following effects. (1) The wear of the rake face and flank of the cutter bit is extremely reduced, and the work efficiency of the shield machine is improved. (2) Since the cemented carbide tip having the rake face and the flank can be fixed to the shank material by one brazing, the brazing performance of the cutter bit is stabilized.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cutter bit according to an embodiment of the present invention.

FIG. 2 is a diagram showing a digging state using the cutter bit of FIG. 1;

FIG. 3 is a view illustrating a cutter bit according to another embodiment of the present invention;

FIG. 4 is a diagram showing a conventional cutter bit.

FIG. 5 is a diagram showing another conventional cutter bit.

FIG. 6 is a diagram showing another conventional cutter bit.

FIG. 7 is a diagram showing another conventional cutter bit.

FIG. 8 is an enlarged view of a joint portion of FIG. 7;

[Explanation of symbols]

 1 shank material 2 carbide tip C rake face D flank

Claims (1)

(57) [Scope of request for utility model registration] 1. A cutter bit for a shield machine, wherein a cemented carbide tip is mounted on a tip of a shank material, wherein the cemented carbide tip has a Λ shape in which a rake face and a flank face are integrally formed.