JP2008095380A - Cutting device and cutting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting device capable of cutting a recessed part of a wall surface of a diaphragm wall construction method, with excellent work efficiency, while shortening work time, without requiring manual work. <P>SOLUTION: This cutting device 1 is composed of a first bracket 2 journaled to the tip of a bendable boom 82 by a horizontal shaft 83 so as to be freely rotatable in the vertical direction, a second bracket 3 journaled to the first bracket 2 by a vertical shaft 50 so as to be freely rotatable in the lateral direction, and a scraping member 4 projecting downward in a tip bent hook shape on the front side from its tip to the second bracket 3, formed in a predetermined lateral width over the projection end 42 from the base end and having a hard scraping blade 4a attachable-detachable to the curved inner peripheral surface 43 side of the projection end 42 in a tapering-off shape on the projection edge by gradually thinning a thickness dimension over to the projection end 42 from the base end. Foreign matter such as earth sticking to the wall surface of the diaphragm wall construction method is removed by the scraping member 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cutting device that removes foreign matters such as soil adhering to a wall surface or the like of an underground continuous wall construction method, and a cutting machine equipped with the cutting device.

  In general, in the underground continuous wall method, especially the SMW method, the crawler or the like equipped with a vertical boom and a vertical boom is used for cutting along the wall around the H steel embedded in the ground. A rotary cutting drum type cutting device provided at the tip of the above-described saddle-buckling-extension boom of a traveling vehicle is used (see, for example, Patent Document 1).

  FIG. 8 shows a conventional representative example of this type of cutting device. The conventional cutting device 7 includes a first bracket 71 pivotally supported by a horizontal shaft 83 at the front end of the bending and extending boom 82 and pivotally movable in the vertical direction. The first bracket 71 is provided with a second bracket 73 pivotally supported by the longitudinal axis 72 so as to be rotatable in the left-right direction, and a rotary cutting drum having a plurality of bits 75 on the outer periphery at the tip of the second bracket 73. 74 is rotatably supported. Reference numeral 76 in the figure denotes a telescopic hydraulic cylinder that rotates the second bracket 73 in the left-right direction with respect to the first bracket 71.

  The rotary cutting drum 74 is rotated by a hydraulic motor 77 to cut along the wall surface. In the apparatus of Patent Document 1 below, a level gauge 78 that protrudes toward the cutting surface side of the drum 74 and regulates the level of the cutting depth by the drum 74 is provided along the side surface of the rotary cutting drum 74. A cutting reference surface is previously formed on the wall surface to be cut, and the cutting depth is regulated in a state where the tip of the level gauge 78 abuts against the reference surface, so that the wall surface W is cut uniformly.

Also, in the work of cutting along the wall surface that is constructed with sheet pile etc. made of metal plate embedded in the underground of the underground continuous wall construction method, and the convex and concave parts form a cross-sectional wave shape that is continuous in the lateral direction, Cutting is performed using a civil engineering heavy machinery such as a backhoe equipped with a bucket at the tip of the boom-bending-extension boom.
Japanese Patent No. 2876308

  However, since the width of the backhoe bucket is generally larger than the width of the concave portion of the wall surface made of the sheet pile P, it is difficult to cut the inside of the concave portion of the wall surface with the backhoe bucket. Moreover, since the horizontal width of the rotary door ram type cutting device 7 is larger than that of the concave portion, the cutting operation is difficult. Therefore, in order to cut the inside of the concave portion of the wall surface, an operator manually cuts using a keren tool provided with a kelen blade at the end of a long rod-like handle. It takes a lot of time and labor, and there is a problem that the worker is fatigued. Further, the worker works near a heavy machinery such as a crawler equipped with the backhoe or the cutting device 7 and there is a problem that the danger is high. .

  Further, conventionally, as shown in FIG. 9, a tip 91 made of a metal plate is detachably attached to the tip edge of the bucket 9 mounted on the bending boom 82 of the backhoe so as to match the shape of the recess of the wall surface W. Although it is conceivable to cut the inside of the concave portion, the bucket 9 can be rotated in the vertical direction with respect to the bending boom 82, but the direction cannot be changed in the horizontal direction, and the inside of the concave portion is roughly cut. However, it is difficult to cut fine portions such as the corners of the recesses, resulting in residual cutting, and the worker must finally finish by hand. In addition, it takes time to attach and detach the tip 91.

  Therefore, the present invention provides a cutting apparatus and a cutting machine that can significantly reduce the working time without cutting manually and can perform cutting work with good workability when cutting a concave portion or the like of the wall surface of the underground continuous wall construction method. It was made as a subject to realize.

  According to the first aspect of the present invention, there is provided a cutting device attached to the distal end of the bending / extending boom of the bending / extending boom comprising a lifting / lowering boom and a bending / extending boom provided at the distal end of the bending / extending boom. And a second bracket having a base end pivotally supported by the longitudinal axis at the distal end of the first bracket so as to be pivotable in the left-right direction. The second bracket protrudes in a hook shape that is bent forward and downward from the distal end, is formed to have a predetermined lateral width from the proximal end to the projecting end on the second bracket side, and extends from the proximal end to the projecting end. As the thickness gradually decreases, the protruding end edge is tapered, and the protruding end is provided with a kelen member having a hard kelen blade that can be attached and detached on the curved inner peripheral surface side. According to this, since the bowl-shaped kelen member is set at the tip of the device that can be turned up and down and left and right by the first and second brackets, the kelen member adheres to the wall surface of the underground continuous wall method. Foreign matter such as soil can be suitably removed, and the worker does not have to perform manual work as in the past.

  According to a second aspect of the present invention, the keren member is provided on the curved outer peripheral portion at a predetermined interval from the protruding end edge of the kelen member along the lateral width direction of the outer peripheral portion, and gently in the outer peripheral direction. A protrusion that protrudes in a substantially chevron-shaped cross section and that can come into contact with the wall surface or the like during a cleansing operation to remove foreign matters such as soil such as the wall surface is provided. According to this, when the foreign material such as soil is scraped off while rotating the protruding end of the keren member downward and forward, the projection of the kelen member abuts against the wall surface, and the sliding resistance against the wall surface can be reduced, so the keren work Can be easily done.

  According to a third aspect of the present invention, the lateral width of the kelen member is matched with the lateral width of the concave portion of the sheet pile made of a metal plate constituting the concave portion and the convex portion extending in the vertical direction such as the wall surface. Is provided to be insertable into the recess. According to this, foreign substances, such as soil adhering in the recessed part of a wall surface, can be removed suitably.

  According to a fourth aspect of the present invention, a plurality of types of different widths are provided in accordance with a plurality of types of sheet piles having different shapes of the recesses. Each keren member is detachably provided on the second bracket. According to this, a keren member can be selected according to the sheet pile which comprises the wall surface of a work site, and a suitable kelen work can be performed.

  In the invention of claim 5, the lateral width of the keren blade is wider than the lateral width of the projecting end of the body of the kelen member, and the projecting end edge of the keren blade is larger than the length dimension of the projecting end edge of the body. The left and right side edges and the protruding edges of the keren blade that protrude from the main body are formed in a tapered shape. According to this, foreign matters such as soil adhering to the concave portion of the wall surface can be suitably removed by the keren blade.

  According to a sixth aspect of the present invention, a plurality of types of sheet piles having different widths are provided in accordance with a plurality of types of sheet piles having different widths of the concave portions, and each of the kelen blades is attached to and detached from the protruding end of the kelen member. Provide as possible. According to this, a keren blade can be selected according to the sheet pile which forms the wall surface of a work site, and a suitable kelen work can be performed.

  According to a seventh aspect of the present invention, the second bracket is rotated by a rotation holding mechanism that holds the second bracket at a predetermined rotation position with respect to the first bracket. As the rotation holding mechanism, a gear provided on the outer periphery of the vertical axis and rotatable integrally with the vertical axis, a rack rod meshed with the gear, and driving the rack rod to move the gear to one side A mechanism provided with a first actuator that rotates in the rotation direction and a second actuator that drives the rack rod and rotates the gear in the other rotation direction. Is used. According to this, the rotation holding mechanism can suitably rotate the keren member to a predetermined position and hold the rotation position. In particular, unnecessary rotation can be prevented even when an external force is applied to the keren member to rotate it.

  The invention according to claim 8 is a cutting machine in which the cutting device is attached to the bending boom of a self-propelled vehicle such as a crawler provided with the bending boom extending from the lifting boom and the bending boom.

  The cutting apparatus of the present invention will be described based on FIG. The cutting device 1 includes a first bracket 2, a second bracket 3, and a keren member 4 provided on the second bracket 3. The first bracket 2 is formed with a pair of left and right bearing pieces 21 on the proximal end side, and the two bearing pieces 21 are provided with two bearings 22 and 23, respectively. A bearing portion 24 is formed on the tip end side of the first bracket 2, and a vertical axis 50 of the rotation holding mechanism 5 is provided on the bearing portion 24 to pivotally support the second bracket 3 so as to be rotatable in the left-right direction. is there.

  The second bracket 3 is provided with a seat plate 31 made of a flat rectangular thick metal plate on the tip side, and bearing pieces 32a and 32b are provided on the back surface of the seat plate 31 in the vertical direction. In the second bracket 3, the rotation holding mechanism 5 is attached to the upper bearing piece 32 a, and the vertical axis 50 is fitted into the bearing portion 24 of the first bracket 2, and the second bracket 3 is attached to the lower end portion of the vertical axis 50. The lower bearing piece 32b of the bracket 3 is supported.

  A kelen member 4 is attached to the second bracket 3 so as to protrude forward through a seat plate 31. The keren member 4 has a hollow structure in which the cross-sectional shape in the lateral direction is substantially square-shaped, and has a bowl shape that is bent forward and downward from the base plate 41 at the base superimposed on the seat plate 31 of the second bracket 3. It is formed.

  The width of the keren member 4 is slightly tapered from the base plate 41 to the projecting end 42, and the projecting end 42 can be inserted into the recess of the sheet pile P (FIG. 4) forming the wall surface W of the underground continuous wall construction method. It is formed in a horizontal width and is installed at about 200 mm. Further, the thickness of the keren member 4 is gradually reduced from the base plate 41 to the protruding end 42 so that the edge of the protruding end 42 is formed in a sharp shape.

  A kelen blade 4a made of a hard thick steel plate is overlapped and fixed to the keren member 4 so as to cover the curved inner peripheral surface 43 side of the protruding end 42. The lateral width of the keren blade 4a is wider than the lateral width of the protruding end 42 of the body of the keren member 4, and is set at about 250 mm. The left and right side edges of the kelen blade 4a projecting from the protruding end 42 of the body 4 are formed in a tapered shape with a gradually reduced thickness. Further, the protruding end edge 42a of the keren blade 4a is longer by about 30 mm than the end edge of the protruding end 42 of the main body 4 and the protruding end edge 42a is formed in a tapered shape with a gradually reduced thickness. The keren blade 4a is fastened and fixed by a plurality of bolt members b and is detachable.

  The curved outer peripheral surface 44 of the keren member 4 protrudes from the outer peripheral surface 44 in a generally chevron or semicircular arc shape from the outer peripheral surface 44 to the outer peripheral direction at a position spaced from the end edge of the protruding end 42 in the root direction. A plurality of projections 45 are provided. Each protrusion 45a, 45b, 45c is provided along the width direction of the outer peripheral surface 44, and the protrusion amount from the outer peripheral surface 44 to the top is set to about 20 to 30 mm.

  The keren member 4 has the base plate overlapped with the back surface of the second bracket 3 on the surface of the seat plate 31 and the peripheral portions of both plate members 31 and 41 are fastened with a number of bolt members b in this state. The keren member 4 is detachable by fastening with a bolt member b.

  2A and 2B are a side view and a plan view showing a partial cross section of the rotation holding mechanism 5. FIG. The rotation holding mechanism 5 includes a vertical axis 50, a gear 51 fixed to the outer periphery of the upper end thereof and rotatable integrally with the vertical axis 50, and first and second meshing with the gear 51 to rotate the gear 51. Rack rods 53A, 53B, and first actuators 54A, 54B and second actuators 55A, 55B for driving the rack rods 53A, 53B.

  The gear 51 is provided in the center of the main body case 59, and a vertical axis 50 projects downward from the center of the lower surface of the main body case 59. In the main body case 59, the first rack rod 53A (upper side of FIG. 2B) and the second rack rod 53B (lower side of FIG. 2B) are provided in parallel with the front and rear positions of the gear 51. The rack rods 53 </ b> A and 53 </ b> B are meshed with the gear 51 so as to be movable in the lateral direction. The first and second rack rods 53A and 53B move in the directions of arrows R and S to rotate the gear 51 in the direction of the arrow X (counterclockwise), and move in the directions of the counter arrows R and S to cause the gears to move. 51 is rotated in the direction of arrow Y (clockwise).

  The first actuators 54A and 54B and the second actuators 55A and 55B are hydraulic cylinder devices and have the same structure. The first actuators 54A and 54B move the first and second rack rods 53A and 53B in the directions of the arrows R and S, and the positions corresponding to one end of the first rack rod 53A (FIG. 2). (Right side of (B)) and a position corresponding to the other end of the second rack rod 53B (left side of FIG. 2 (B)). Each actuator 54A, 54B has a cylindrical cylinder portion 541, and a piston 542 connected to the end of each rack rod 53A, 53B protruding from the main body case 59 is movably inserted into each cylinder portion 541. It is. The terminal of the cylinder part 541 is closed, and the closed terminal is provided with an inlet / outlet 543 through which hydraulic oil can be taken in and out of the cylinder part 541.

  Each of the second actuators 55A and 55B includes the other end of the first rack rod 53A (left side of FIG. 2B) and one end of the second rack rod 53B (of FIG. 2B). The piston 552 provided on the right side) and connected to the ends of the rack rods 53A and 53B is movably inserted into the cylinder portion 551.

  The rotation holding mechanism 5 drives the first actuators 54A and 54B to push the piston 542, thereby moving the first and second rack rods 53A and 53B in the directions of arrows R and S. At this time, both the second actuators 55A and 55B open the hydraulic oil inlet / outlet 553 so that the hydraulic oil can escape. As the rack rods 53A and 53B move in the directions of arrows R and S, the vertical axis 50 rotates integrally with the gear 51 in the direction of arrow X. Conversely, the second actuators 55A and 55B are driven and the rack rods 53A and 53B are moved in the opposite arrow R and S directions, whereby the gear 51 and the vertical axis 50 are rotated in the arrow Y direction.

  Further, when the rotation holding mechanism 5 is not in operation, the inlets 543 and 553 of the first and second actuators 54A, 54B, 55A and 55B are closed and the hydraulic pressure cannot be released, so that the rack rods 53A and 53B are opened from both sides. The gear 51 and the vertical axis 50 are held at a predetermined rotational position without being held and moved.

  The cutting device 1 has the main body case 59 side of the rotation holding mechanism 5 fixed to the second bracket 3, and the vertical axis 50 is fixed to the first bracket 2. The vertical axis 50 fixed to the bracket 2 is not rotated, but the body case 59 side is rotated integrally with the second bracket 3. The left and right turning range of the cutting device 1 is rotatable about 60 degrees in the left and right direction.

  As shown in FIG. 3, the cutting device 1 includes a lifting boom 81 whose base end is pivotally supported on a turntable 61 of a self-propelled vehicle 6 such as a crawler, and a bending boom 82 pivotally supported on the distal end of the lifting boom 81. It attaches to the front-end | tip of the bending boom 82 of the comprised saddle bending extension boom 8. FIG. A horizontal shaft 83 laid horizontally at the tip of the bending boom 82 is received by the bearing 22 of the first bracket 2 of the cutting device 1 and is connected to the tip of the bending boom 82 so as to be rotatable in the vertical direction. The bearing 23 of the first bracket 2 is connected to the tip of the cylinder device 84 of the bending boom 82. By the expansion and contraction operation of the cylinder device 84, the cutting device 1 rotates in the vertical direction at the tip of the bending boom 82.

  Therefore, the cutting device 1 is configured to turn up and down around the horizontal shaft 83 as the first bracket 2 is turned up and down by the cylinder device 84 at the front end of the bending and extending boom 82, and to rotate the second holding mechanism 5. By swinging left and right around the vertical axis 50 with the left and right rotation of the bracket 3 singly or in combination, it is possible to adapt to various wall surfaces.

  Based on FIG. 4 and FIG. 5, a description will be given of a cutting swelling operation (hereinafter simply referred to as a swelling operation) of the wall surface W of the underground continuous wall method by the cutting device 1. The wall surface W is formed in a cross-sectional wave shape in which a plurality of sheet piles P made of metal plates extending in the vertical direction and having a substantially cross-sectional cross section are alternately arranged, and the concave portions W1 and the convex portions W2 are continuous in the lateral direction. . The wall surface W is cut with a backhoe bucket or the like so as to be substantially flush with the convex portion W2, and then the inside of the concave portion W1 is subjected to a cleansing operation with the cutting device 1 of the present embodiment.

  The cutting device 1 directs the protruding end 42 of the keren member 4 forward, and inserts the protruding end 42 into the recess W1 in this state. Then, the entire cutting device 1 is rotated downward so as to move the protruding end 42 downward and to the near side (the self-propelled vehicle side) while being inserted, and the keren blade provided on the inner peripheral surface 43 side of the protruding end 42 In 4a, the soil C in the recess W1 is scraped off. This scraping operation is sequentially repeated from the upper end side to the lower end side of the recess W1.

  At the time of scraping work, the projection 45 having a cross-sectional mountain shape or semicircular arc shape provided on the outer peripheral surface 44 of the keren member 4 comes into contact with and slides on the bottom surface of the recess W1. In this case, since the protrusion 45 is in line contact with the bottom surface and has a small sliding resistance, the downward rotation of the cutting device 1 can be smoothly performed. Further, since a plurality of protrusions 45 are provided on the outer peripheral surface 44 from the protruding end 42 side to the base plate 41 side, the protrusions 45 that come into contact with and slide on the bottom surface sequentially change as the cutting device 1 rotates. The outer peripheral surface 44 does not come into contact with the bottom surface.

  As shown in FIG. 6, generally, the concave portion W1 of the wall surface W is inclined so that the side surfaces on both sides open with respect to the bottom surface. On the other hand, since the cutting device 1 is provided so that the keren part 4 can be rotated in the left-right direction from the second bracket 3 with respect to the bending boom 82, the kelen part 4 is rotated in the left-right direction, and the keren blade By aligning the side edge of 4a with the inclination angle of the side surface of the recess W1, the keren work can be easily performed along the side surface.

  Further, the keren member 4 is rotated in the left-right direction by the rotation holding mechanism 5 and is held at an arbitrary rotation position. Therefore, the holding force at the rotation position of the rotation holding mechanism 5 is high. When the keren member 4 is inclined obliquely and the side surface of the recess W1 is keelted, an external force is applied to the kelen member 4 to rotate it left and right. 4 unnecessary rotation can be prevented.

  Further, as shown in FIG. 7, the self-propelled vehicle and its bending boom 82 do not necessarily face the front position of the concave portion W1 of the wall surface W where the cleansing work is performed by rotating the keren member 4 in the left-right direction. Since the bending boom 82 is obliquely directed in the left-right direction and the keren member 4 is directly opposed to the recess W1, the keren work can be performed, so that the plurality of the recesses W1 can be continued without moving the self-propelled vehicle.

  According to the present embodiment, the keren member 4 of the cutting device 1 can perform the keren work all over the concave portion W1 of the wall surface W, and fine work finishes such as corners can be performed. This eliminates the need for manual work, shortening work time and labor.

  The sheet pile P constituting the wall surface W has a plurality of types having different widths, and the width of the recess W1 may differ depending on each construction site. Therefore, the cutting device 1 is provided with the kelen member 4 so as to be attachable to and detachable from the second bracket. Therefore, a plurality of types of kelen members having different widths are prepared in accordance with each type of sheet pile P having different widths. If this is the case, the keren member can be selected according to the construction site. Furthermore, since the kelen blade 4a is detachably provided on the keren member 4, if a plurality of types of kelen members having different widths are prepared for each type of sheet pile P, the kelen blades 4a are adapted to each construction site. The blade can be selected. Further, when the kelen blade 4a is damaged, only this can be replaced, and the kelen member 4 main body is hardly damaged, which is economical. When the keren blade 4a is attached to the protruding end 42 of the keren member 4, a split structure may be used. For example, if the part along the one of the left and right side edges of the projecting end 42, the part along the other, and the part along the projecting edge of the projecting end 42 are divided into three parts, the attaching / detaching operation to the keren member 4 becomes easy.

  In addition, the above-mentioned embodiment is an illustration in all points, and does not limit the scope of the present invention, and the present invention includes various modifications and changes to the above-described embodiment. For example, in the above-described embodiment, the keren member 4 is rotated in the left-right direction by the rotation holding mechanism 5, but the present invention is not limited to this, and a telescopic hydraulic cylinder such as a conventional cutting device may be used. Good. However, the rotation holding mechanism 5 described above is more preferable than the hydraulic cylinder because the rotation position is not changed by an external force acting on the keren member.

FIG. 1A is a plan view of the cutting apparatus of the present invention, and FIG. 1B is a side view thereof. FIG. 2A is a side view with a partial cross-section thereof, and FIG. 2A is a plan view with a partial cross-section thereof. It is a side view of a cutting machine carrying a cutting device of the present invention. It is a top view which shows the operation | work process which cuts the recessed part of a wall surface using the said cutting device. It is a side view which shows the operation | work process which cuts the recessed part of a wall surface using the said cutting device. It is a top view which shows the operation | work process which cuts the side surface of the recessed part of a wall surface with the said cutting device. It is a top view which shows the operation | work process which cuts the other recessed part of a wall surface with the said cutting device. It is a top view which shows the conventional cutting device. It is a top view which shows the operation | work process which provides an attachment at the front-end | tip of buckets, such as the conventional backhoe, and performs a cutting operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutting device 2 1st bracket 3 2nd bracket 4 Keren member 4a Keren blade 42 Projection end 43 Inner peripheral surface 44 Outer peripheral surface 45a, 45b, 45c Protrusion 5 Rotation holding mechanism 50 Vertical axis 51 Gear 53A, 53B Rack 54A , 54B 1st actuator 55A, 55B 2nd actuator 6 Self-propelled vehicle 61 Turntable 8 Climbing boom 81 Climbing boom 82 Bending boom 83 Horizontal axis P Sheet pile W Wall surface W1 Concavity W2 Convex portion C Soil

Claims (8)

A cutting device attached to the tip of the above-described bending boom of a bending-extension boom comprising a lifting boom and a bending boom provided at its tip,
A first bracket having a base end pivotally supported by a horizontal axis at the tip of a bending boom, and a base end pivotally supported by a vertical axis at the tip of the first bracket. With a second bracket
The second bracket protrudes in a hook shape that is bent forward and downward from the front end thereof, is formed to have a predetermined lateral width from the base end to the protrusion end on the second bracket side, and protrudes from the base end The protruding end edge is tapered with the thickness dimension gradually decreasing toward the end, and the protruding end is provided with a hard kelen blade that can be attached to and detached from the curved inner peripheral surface, and adheres to the wall surface of the underground continuous wall method. A cutting apparatus provided with a cleansing member for removing foreign matter such as soil.   Provided along the lateral width direction of the outer peripheral portion at a predetermined interval from the protruding edge of the kelen member on the curved outer peripheral portion of the kelen member, and protrudes in a substantially cross-sectional shape with a gentle cross section in the outer peripheral direction. The cutting device according to claim 1, wherein a protrusion capable of contacting the wall surface or the like is provided during a cleansing operation for removing foreign matters such as soil such as the wall surface.   The width of the kelen member is adjusted to the width of the concave portion of the sheet pile made of a metal plate constituting the concave portion and the convex portion extending in the vertical direction such as the wall surface, and the protruding end of the kelen member can be inserted into the concave portion. The cutting device according to claim 1 or 2 provided. The above-mentioned kelen member is matched to each of a plurality of types of sheet piles having different widths of the recesses, and a plurality of types having different widths are provided,
The cutting device according to any one of claims 1 to 3, wherein each keren member is detachably provided on the second bracket.   The lateral width of the keren blade is wider than the lateral width of the protruding end of the main body of the kelen member, and the protruding end edge of the kelen blade is longer than the length of the protruding end edge of the main body. The cutting device according to claim 1 or 2, wherein the left and right side edges of the protruding Keren blade and the protruding edges are tapered. Matching the keren blade to each of a plurality of types of sheet piles having different widths of the recesses, providing a plurality of types having different widths,
The cutting device according to claim 5, wherein each keren blade is detachably provided at a protruding end of the keren member. The second bracket is rotated by a rotation holding mechanism that holds the second bracket at a predetermined rotation position with respect to the first bracket.
As the rotation holding mechanism, a gear provided on the outer periphery of the vertical axis and rotatable integrally with the vertical axis, a rack rod meshed with the gear, and driving the rack rod to move the gear to one side A mechanism provided with a first actuator that rotates in the rotation direction and a second actuator that drives the rack rod and rotates the gear in the other rotation direction. The cutting device according to any one of claims 1 to 3, wherein the cutting device is used.   The base end of the hoisting and booming boom including the hoisting and booming boom and the bending and extending boom provided at the tip of the boom is supported by a turntable of a self-propelled vehicle such as a crawler, and the first bracket The base end of the second bracket is pivotally supported so as to be pivotable in the vertical direction, and the base end of the second bracket is pivotally supported so as to be pivotable in the horizontal direction at the tip of the first bracket. A cutting machine characterized by comprising a kelen member that removes foreign matters such as soil adhering to a wall surface or the like of an excavation site with a protruding end having a sharp bent edge protruding in a bent shape.