JP3461250B2 - Cutter bit unit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutter bit unit for a rock or other cutting device (cutter, excavator, etc.). 2. Description of the Related Art Conventionally, as shown in FIG. 2, a rotary cutter having a plurality of cutter bit units mounted on the front surface of a rotary head having a circular shape in a front view has been used for tunnel construction and the like. The cutter bit unit is a combination of a cutter bit and a frame holder on which the cutter bit is mounted, and is disposed on the front surface of the rotary head. When the front surface of the rotary head of the rotary cutter is rotated while being pressed against a cut object such as rock, a plurality of cutter bits roll on concentric circles and cut rocks or the like with the sharp cutting edge. [0003] A cutter bit at the tip of a cutting machine such as the rotary cutter described above is often replaced on site due to wear, breakage, change of use, etc., and various methods for relatively easy replacement have been devised. As a method,
It is common to insert a cutter bit into the frame holder and fix it with bolts, stopper rings, knock pins, etc. There is usually a slight gap between them. [0004] However, in the above-mentioned conventional fixing method of the cutter bit, since the backlash is generated due to a gap or the fixing portion is loosened due to vibrations during the operation, the cutter bit is not used. There are various problems such as a shortened service life of the device, a reduction in work efficiency, and a failure of the fixing portion to make it impossible to remove. Especially in recent years,
The work to excavate gravel, bedrock, etc. at high speed is increasing, and the above problem is a bottleneck in the work process. SUMMARY OF THE INVENTION It is an object of the present invention to provide a cutter bit unit in which the operation of attaching and detaching the cutter bit is relatively easy, and the fixed portion of the cutter bit does not loosen even during the cutting operation. Means for Solving the Problems In order to solve the above problems, the present invention has the following configuration. That is, the cutter bit unit of the present invention is a cutter bit unit of a cutting machine that performs cutting by pressing and moving the cutter bit against a surface to be cut such as rock, and the cutter bit and a frame body to which the cutter bit is attached. Provide a gap between the holder and the frame, and hold the cutter bit in the gap with a spacer made of a shape memory alloy that stores the shape that increases the apparent thickness when the temperature exceeds a specific temperature higher than room temperature. It is characterized by being fixed to the body holder. Hereinafter, the present invention will be described in detail with reference to specific examples. When attaching the cutter bit to the holder of the cutter bit unit, the cutter bit is fixed with a spacer, for example, a NiTi-based shape memory alloy plate sandwiched in a gap provided between the cutter bit and the holder. [0008] The shape memory alloy in which the shape is stored is deformed into another shape at a temperature near normal temperature (about 7% or less in deformation amount), but when the temperature exceeds a specific temperature (transformation point). An alloy having the property of reviving shape memory and recovering to the predetermined shape. In general, the stress generated when the shape recovers at or above the transformation point reaches a maximum of 600 MPa,
At room temperature, the generated stress is significantly reduced. The transformation point can be adjusted by changing the alloy composition during the production of the shape memory alloy, and alloys with various transformation points are available. The spacer of the present invention has a transformation point of 30.
A shape in which the apparent thickness increases, such as a change from a flat plate at normal temperature to a waveform at the transformation point, is preferable, although the shape to be stored is not particularly limited. . In the present invention, the cutter bit is fixed with the spacers interposed therebetween, so that the thickness is small near the mounting time (normal temperature). If the cutter bit becomes hot immediately after the start of work, the temperature of the spacer also rises, and the shape stored in the spacer is revived and a strong pressure is generated in the direction of increasing the thickness. And the holder fixed to the cutting machine head can be completely integrated. As described above, in the cutter bit unit of the present invention, when the cutter bit is attached to the holder, a thin spacer having a flat shape or the like can be easily inserted into the gap. The strong pressure causes the cutter bit to be completely integrated with the holder. Further, when the cutter bit is removed, if the spacer is cooled to about room temperature by spraying with water or the like, the pressure is reduced, so that the cutter bit can be removed relatively easily. The spacer used once can be made into a thin shape such as a flat plate again by pressing or the like, and then reused repeatedly. Embodiments of the present invention shown in the drawings will be specifically described below. As shown in FIG.
Are provided with a plurality of cutter bit units 5,... On the front surface of the head by welding. FIG. 1 shows one embodiment of the present invention,
It is an enlarged view of the cutter bit unit 5. A gap 11 is provided between the cutter bit 7 and the frame holder 9, and in a state where the spacer 13 is inserted into the gap 11, the cutter bit 7 inserts a bolt 15 for preventing deviation from the screw hole. 17 and attached to the frame holder 9. Cutter bit 7
A carbide tip 19 is brazed to the cutting edge of. Arrow a
Indicates the rotation direction of the head 1. The spacer 13 has a flat plate shape (may be slightly uneven) at a temperature around room temperature (may be slightly higher), but has a shape memory alloy (shape) that stores a waveform at 50 ° C. or more. (NiTi-based) plate, and when heated, the waveform is revived and exerts a strong pressure in the direction of increasing the thickness.
The shape to be stored in the spacer 13 does not need to be limited to a waveform, and any other shape may be used as long as the shape exerts pressure in the direction of increasing the thickness when the temperature exceeds the transformation point. The number of the spacers 13 to be inserted is preferably such that they fill the gap 11, and one to an arbitrary number are inserted at room temperature. FIG. 3 shows another embodiment of the present invention, in which a bit holder 21 provided on the outer periphery of the front face of the rotary head 1 of the cutting machine is provided.
2 shows a state where the cutter bit 7 is attached. 3, a spacer 13 is inserted into the gap 11, and the spacer 13 plays a role similar to that of FIG. FIG. 4 shows another embodiment of the present invention.
As shown in FIG. 4B, the spacer 31 has a substantially cylindrical shape, and as shown in FIG.
Bit holder 3 so that
7 and the spacer 31 is 80
When the temperature is equal to or higher than ° C., the cutter bit 33 and the cutting machine head 39 are completely integrated by exerting pressure in a direction of increasing the thickness. FIG. 5 shows a still further embodiment of the present invention, which is the same as the embodiment shown in FIG. 4 except that the cutter bit 33 and its base 35 are prismatic. . The spacer 31 is a pair, and is fixed by inserting a pin into the pin hole 38. FIG. 6 shows still another embodiment of the present invention. A cutting machine in which the rotary head 43 can bidirectionally rotate during cutting, and two bit 41 of a plurality of cutter bits are provided in bit holders 45 provided on the head 43.
a and 41b are shown as a pair and the blades are mounted in opposite directions. The spacer 47 inserted at this time
(Transformation point 100 ° C) shall be thin, and the strength of the pressure when shape memory is revived also pushes the cutter bits 41a and 41b so as to be in the position of the solid line. Is designed to be strong enough to move in the escape direction (the position indicated by the dotted line). For example, when the rotation direction during cutting is in the direction of arrow a, one of the cutter bits 41a cuts in and contributes to cutting, while the other cutter bit 41b moves in the escape direction to reduce the height of the blade. The direction of the cutting edge is reversed, and does not bite, and does not contribute to cutting. When the rotation direction is the reverse direction of the arrow b, the cutter bit 41b contributes to cutting, and the cutter bit 41a does not contribute to cutting. The embodiment shown in FIG. 6 is suitable for the case where the ground is frozen or the case of the freezing method in which the ground is frozen and cut intentionally. It has the advantage that it easily penetrates into the hole and that the standard dimensions for initial cutting are easy to determine. As is apparent from the above description, the cutter bit unit according to the present invention allows the cutter bit to be easily attached and detached, and completely integrates the cutter bit and the frame holder at high pressure during operation. As a result, the play as in the prior art has been eliminated, and the cutting operation can be performed efficiently with less wear of the cutter bit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of one embodiment of the present invention. FIG. 2 is a side view of a general rotary cutter head. FIG. 3 is a side view of another embodiment of the present invention. FIG. 4 is a side view and a perspective view of another embodiment of the present invention. FIG. 5 is a side view and a perspective view of another embodiment of the present invention. FIG. 6 is a side view of another embodiment of the present invention. [Description of Signs] 1 Rotating head 5 Cutter bit unit 7 Cutter bit 9 Frame holder 13 Spacer 31 Spacer 33 Cutter bit 37 Bit holder 41a, 41b Cutter bit 47 Spacer

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Akemi Hasegawa 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division (72) Inventor Maki Tao 2--Matsuzakicho, Abeno-ku, Osaka-shi 2-2 Okumura Gumi Co., Ltd. (72) Inventor Tatsuhiro Furonaga 2-2-2 Matsuzakicho, Abeno-ku, Osaka City Innovator Okumura Gumi (72) Nobuo Terao 3-16 Shindo, Matsubara-shi, Osaka Star Roy Sangyo (56) References JP-A-63-75285 (JP, A) JP-A-58-11591 (JP, U) JP-A-58-115592 (JP, U) JP-A-63-81995 (JP, A) U) Japanese Utility Model Application Hei 5-22686 (JP, U) Japanese Utility Model Application Hei 5-75285 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) E21B 10/62

Claims (1)

(57) [Claim 1] A cutter bit unit of a cutting machine for performing cutting by pressing and moving a cutter bit against a surface to be cut such as a rock, wherein the cutter bit and the cutter bit are Provide a gap between the frame holder to be attached, in the state of sandwiching a spacer of a shape memory alloy that stores the shape whose apparent thickness increases when the temperature becomes higher than a specific temperature higher than room temperature, A cutter bit unit wherein the cutter bit is fixed to a frame holder.