JPH0338314Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an over-digging cutter that is incorporated into the tip of the cutter head of a shield machine and is used to over-dig the side surface of a hole on the winding side during winding. .

(Prior Art) In general, a shield excavator has a radially arranged cutter head 1 that excavates by moving forward in the axial direction while rotating as shown in FIG. A cutter 3 for over-digging that is moved in and out is provided, and is projected only within a certain angle range according to the rotation of the cutter head 1, so that the side surface on the curved side is over-cut.

As shown in FIG. 4, the over-digging cutter used in this type of device includes a cutting edge portion 5 having an acute angle on both edges on the cutter rotation direction side (arrow x side) at the top of the cutter base material 4; 5, with carbide chips 6, 6 made of a carbide material fixed to the side surfaces of the cutting edge portions 5, 5 in the rotational direction, or as shown in FIG. As shown in FIG. 6, base material 4 is formed into a simple rectangular prism shape, and carbide chips 6, 6 are fixed to both sides of the top in the rotating direction.

(Problems to be solved by the invention) Such conventional cutters for over-digging have had the following problems.

(1) The cutter head of the shield excavator receives approximately 100% of the earth pressure from the direction of propulsion, which may cause breakage.

(2) The cutting ability is only at the side edge of the top in the direction of rotation, and the base material other than the carbide tip is subject to wear due to the flow of cutting soil and pressing against the ground, which is related to (1) above. It may also cause breakage.

(3) The carbide chip on the back side in the direction of cutter rotation is peeled off by the flow of cutting soil, or the base material is heavily worn.

(4) Since only the tip of the cutter head in the direction of rotation is cut, the over-digging effect is unreliable and the cutting ability is not sufficient.

In view of these various conventional problems, the present invention has been developed to ensure that even when excavation is carried out with an over-digging cutter at the same time as the cutter head is propelled, the ground on the side of the propulsion direction is well cut, the cutting ability is high, and the excavation is performed in the propulsion direction. The object of the present invention is to provide a cutter for over-digging for a shield excavator, which is free from breakage due to earth pressure from the ground, and which causes less peeling of the carbide chips on the back side in the direction of rotation and less wear on the base material.

(Means for Solving the Problems) In order to solve the various problems mentioned above and achieve the initial purpose, the present invention rotates around a swing drive shaft, and moves in the axial direction of the swing drive shaft. In an over-digging cutter including an over cutter or a copy cutter of a shield excavator, which is provided in a cutter head of a shield excavator that advances and is moved in and out of the radial tip of the cutter head, the cutter head of the cutter base material A cutting blade section is formed from the upper part to the lower part of both edges of the advancing surface, and a carbide chip made of a carbide material is fixed to a part or substantially the entire area of the cutting edge part, and the advancement of the cutter base material is One or more leading bits are provided between the two cutting blades on the surface and the top, the tips of which protrude forward from the cutting blades.

(Function) This invention provides cutting blades on both edges of the cutter head propulsion side of the cutter base material, and a carbide tip is fixed to this, so that when the cutting blade is rotated at the same time as propulsion, the inner rotation of both edges is reduced. A cut is made to the cutting edge portion on the direction side, and the entire cutting edge portion is used to cut the ground.

In addition, since the leading bit between both cutting blades protrudes from the cutting blade in the direction of propulsion, the part to be cut by the cutting blade breaks down during the next rotation, creating a free surface, which prevents cutting. The resistance is also reduced, and the earth pressure acting on the cutting edge on the back side in the direction of rotation is also reduced.

(Example) Next, an example of implementing the present invention will be described with reference to FIGS. 1 and 2.

In the figure, A is a cutter for over-digging according to the present invention, and as shown in FIG. 2, it is housed in a cutter head 10 and is projected from a tip opening 10a of the cutter head 10 by a hydraulic device 11, as in the conventional case. .

This cutter A for over-digging has a cutter base material 13 protruding from the tip of a support portion 12. The entire cutter base material 13 for over-digging is formed into a prismatic shape, and a pair of cutting blades 15a, 15b having carbide tips 14a, 14b made of a carbide material fixed to both longitudinal edges of the side surface in the direction of propulsion of the cutter head are at the top. It is formed over almost the entire length from the base to the base.

A recess is formed along the longitudinal direction at the center of the side surface in the propulsion direction of the cutter base material 13, and both cutting blade portions 15a,
15b is provided with a relief angle α in the rotational direction, and the top of the cutter base material 13 is formed lower on the rear side in the direction of propulsion Y, and is provided with a relief angle β in the direction of propulsion.

A plurality of leading bits 16, 16, . . . arranged in one or more rows are protruded between the two cutting blade portions 15a, 15b on the surface of the cutter base material 13 in the direction of propulsion. Each of the leading bits 16 is formed to have a length such that its tip protrudes further forward than both cutting blade portions 15a, 15b, that is, toward the propulsion direction Y side. Further, a leading bit 17 is also formed between the tops of both carbide chips 14a and 14b on the top surface of the cutter base material 13.
One or more are protruded. Both leading bits 16 and 17 are each molded from a superhard material and are fixed to the cutter base material 13.

The over-digging cutter A configured as described above is made to protrude from the tip of the cutter head 10, and by rotating the cutter head 10 while applying an axial propulsive force, the cutting edge on the side of the rotation direction of the over-digging cutter A is formed. The portion 15a or 15b is turned while cutting into the earth, and the entire cutting edge portion of one edge in the longitudinal direction cuts the earth. Further, the leading bits 16 and 17 are the cutting edge portions 15a.
Since it protrudes even further, the carbide chip breaks down the ground surface to be cut by the cutting blade part 15a in advance, making cutting easier and forming the cutting blade part 15b or 15a which is on the back side in the direction of rotation. 14
The back pressure applied to b or 14a is reduced, and peeling of chips and wear of the tip of the cutter base material are prevented.

(Effects of the invention) The over-digging cutter of the shield excavator of the present invention is constructed as described above, and both edges of the side surfaces of the cutter head in the direction of propulsion of the over-digging cutter are formed into cutting blade portions over almost the entire area thereof. Therefore, when cutting is performed by protruding the cutter head at the same time as the cutter head is propelled, the rock is cut by the entire cutting edge on the rotation direction side, and stable cutting can be obtained. The entire cutting blade is made of carbide chips, which reduces wear on the base material, and the provision of a leading bit makes cutting with the cutting blade easy, and also prevents the backing of earth and sand against the back side in the direction of rotation. As the pressure is reduced, peeling of the carbide tip and wear of the cutter base material are significantly reduced.

In addition, the cutter for over-digging can be used to make over-excavation easier to propel the entire shield excavator when traveling straight through hard ground or areas where the ground has been improved, regardless of whether the excavator is traveling in a curved direction. It has become something that can be earned.

[Brief explanation of drawings]

Figure 1 shows an example of the cutter for over-digging according to the present invention, where A is a plan view, B is a front view, C is a side view, and Figure 2 is a cross-sectional view of the cutter for over-digging in an installed state. Figure 3 is a sectional view of the cutter head of a conventional shield excavator, and Figures 4 to 6 each show a conventional over-digging cutter. In each figure, A is a plan view, B is a front view, and C is a side view. It is a diagram. A... cutter for extra digging, 10... cutter head, 12... support part, 13... cutter base material,
14a, 14b...Carbide chip, 15a, 15b
... Cutting blade section, 16, 17 ... Leading bit.

Claims (1)

[Scope of utility model registration request] An over cutter of a shield excavator that is provided in a cutter head of a shield excavator that rotates around a rotation drive shaft and moves forward in the axial direction of the rotation drive shaft, and that is moved in and out of the radial tip of the cutter head; In a cutter for over-digging including a copy cutter, the cutter base material has a cutting blade section from the top to the bottom of both edges of the cutter head advancing surface, and the cutting blade section includes a part or substantially the entire area thereof. One or more chips to which a carbide tip made of a carbide material is fixed, and which is located between the cutting blades on the advancing surface and the top of the cutter base material, and has a tip protruding forward from the cutting blades. A cutter for over-digging of a shield excavator, which is characterized by being equipped with several leading bits.