Notch forming device

Abstract

This cutout forming device is provided with: a cutting blade (16) for forming a cutout in a coating film of a liner tube; a trolley part (12) having wheels on the front, rear, left and right sides and capable of traveling in the front-rear direction; and a cutting blade support part (17) which supports the cutting blade at an upper position of the trolley part in a manner that the support height can be changed and applies a force to the upper part. It is preferable that two disc-shaped rotating blades (16a, 16b) are provided as the cutting blades, and the rotating blades (16a, 16b) are rotatably supported by the cutting blade support section and are disposed in the left-right direction at a prescribed interval.

Description

Technical Field

[0001] The present invention relates to a cut forming device, and more particularly, to a device for forming a cut on an old film when regenerating a tubular member having a film such as a regenerated lined steel pipe to facilitate peeling. Background Art

[0002] Lined pipes having a film formed by fixing a resin material such as polyolefin such as polyethylene and polypropylene, and rubber material such as vinyl chloride on the surface (inner surface or outer surface) of a metal pipe such as a steel pipe are used in various industrial fields.

[0003] For example, a polyethylene powder lined steel pipe (PEL) having a film formed by heat-fusing polyethylene powder on the surface of a steel pipe has excellent characteristics such as chemical and physical stability of the film and easy processing, and is therefore used as a corrosion-resistant steel pipe for pipes for transporting various fluids.

[0004] In addition, in recent years, from the viewpoints of resource recycling and reduction of environmental load, reuse of lined pipes has also been attempted. When reusing, the lined pipe is regenerated by peeling off an old film deteriorated due to years of use and forming a new film.

[0005] In addition, as a document disclosing a technique for peeling a film from a lined pipe, there is Japanese Patent Application Laid-Open No. 2001-191330. Summary of the Invention

[0006] Incidentally, when peeling an old film from a lined pipe, conventionally, an operation of forming a cut on the film with a cutter in a manner of dividing the film has been performed. This is to make the film easily peel off.

[0007] On the one hand, there is still room for improvement in terms of safety and workability in such a cut operation. This is because the operation using a cutter poses a risk of injury and requires a great deal of labor. In addition, depending on the diameter and length of the pipe, there are also cases where the hand cannot reach and a cut cannot be formed.

[0008] On the other hand, the above-mentioned Patent Document 1 discloses an instrument for forming a cut on a film (referred to as an "inner film" in the present application) formed on the inner surface of a pipe (refer to the drawings of the document Figure 6 , paragraphs

[0062] to

[0067] of the specification). However, in this instrument, since the instrument is supported in the pipe by two upper and lower blades, it is not necessarily easy to stably travel the instrument in the pipe axis direction and perform the cut operation with good workability.

[0009] In addition, in this instrument, a cut cannot be formed on a film (referred to as an "outer film" in the present application) formed on the outer surface of the pipe. Further, in Patent Document 1, another instrument for forming a cut on the outer film is shown (refer to the drawings of the documentFigure 8 (see paragraph

[0068] of the specification), but there is a trouble that separate tools must be prepared for the inner coating film and the outer coating film. Further, neither the tool shown in Patent Document 1 Figure 6 nor the tool shown in this document Figure 8 can form a cut in the circumferential direction of the tube.

[0010] Accordingly, an object of the present invention is to provide a cut forming device that can perform a cut operation on a coating film safely and with good workability, and can form a cut on either the inner coating film or the outer coating film, and on either the axial direction or the circumferential direction of the tube.

[0011] To solve the above problems and achieve the object, the cut forming device of the present invention includes: a cutting edge that forms a cut on the coating film of the inner liner tube; a carriage unit that has wheels in the front, rear, left, and right directions and can travel in the front-rear direction; and a cutting edge support unit that supports the cutting edge above the carriage unit so that the support height can be changed and applies an upward force. In addition, in the present application, the above cut forming device may sometimes be referred to as a "cut device" or simply as a "device", the inner liner tube may be referred to as a "tube", and the above cutting edge and a rotating edge described later may be referred to as an "edge".

[0012] The cut forming device of the present invention can form a cut on either the coating film (inner coating film) formed on the inner surface of the inner liner tube or the coating film (outer coating film) formed on the outer surface in the tube axial direction (axis direction of the inner liner tube) and the circumferential direction.

[0013] Hereinafter, the respective usage methods of the present device will be described with (a) forming a cut in the tube axial direction of the inner coating film as the "first usage method", (b) forming a cut in the circumferential direction of the inner coating film as the "second usage method", (c) forming a cut in the tube axial direction of the outer coating film as the "third usage method", and (d) forming a cut in the circumferential direction of the outer coating film as the "fourth usage method".

[0014] (a) First usage method

[0015] In order to form a cut in the tube axial direction of the inner coating film, the present device is disposed in the tube so that the front-rear direction of the present device coincides with the tube axial direction (see Figure 3 and Figure 4 described later). At this time, after operating the cutting edge support unit to lower the cutting edge downward, the present device is placed in the tube, and then, the cutting edge support unit is operated to raise the cutting edge so that the cutting edge presses against the coating film formed on the inner surface of the tube (the cutting edge is pressed against the coating film by being upwardly forced by the cutting edge support unit). Then, in this state, the present device (carriage unit) is caused to travel in the tube axial direction (front-rear direction). Thus, the inner coating film is cut by the cutting edge pressing against the inner coating film, and a cut can be formed in the tube axial direction of the inner coating film.

[0016] (b) Second usage mode

[0017] In order to form a circumferential incision in the inner lining film so that the left - right direction of this device is consistent with the pipe axis direction, this device is arranged inside the pipe in such a way (refer to Figure 5 and Figure 6 described later). At this time, operate the cutting - edge support part to lower the cutting edge as in the above - mentioned first usage mode. After this device is set inside the pipe, raise the cutting edge to press the cutting edge against the inner lining film. Then, in this state, for example, by rotating the inner lining pipe around the pipe axis (with the pipe axis as the center), make this device (the trolley part) move relatively (relative to the inner lining pipe) circumferentially around the pipe, and a circumferential incision can be formed in the inner lining film.

[0018] Here, in the present invention, "movement" (relative to the trolley part) means that the trolley part (and further the incision - forming device or the cutting edge) moves relatively to the inner lining pipe (the film). That is, "movement" in the present invention not only means the movement of the trolley part itself, but also includes the following concepts: when the trolley part (the incision device or the cutting edge) itself does not move, the inner lining pipe moves or rotates, so that the film moves relative to the trolley part; and when both the trolley part (the incision device or the cutting edge) and the inner lining pipe (the film) move or rotate, the trolley part (the incision device or the cutting edge) moves relatively to the inner lining pipe (the film) (for example, the trolley part and the inner lining pipe move or rotate in opposite directions). This is because if the cutting edge and the film move relatively, in any case, the film can be cut by the cutting edge pressed against the pipe wall to form an incision.

[0019] Therefore, in the above - mentioned second usage mode, usually the inner lining pipe is rotated, but the incision device can also be rotated without rotating the inner lining pipe, or the inner lining pipe and the incision device can be rotated in opposite directions. The same applies to the above - mentioned first usage mode. The incision device can move relatively to the inner lining pipe by moving the inner lining pipe in the pipe - axis direction without moving the incision device, or the incision device and the inner lining pipe can move in opposite directions. The same also applies to the third usage mode described below and the fourth usage mode described later.

[0020] (c) Third usage mode

[0021] In order to form an incision in the outer lining film in the pipe - axis direction, place the incision device, for example, on the floor, and arrange the inner lining pipe in such a way that the front - back direction of the incision device is consistent with the pipe axis direction and it is placed on the cutting edge (refer to Figure 7 and Figure 8). In addition, at this time, part or all of the weight of the inner liner can be applied to the cutting device (cutting blade) (the same applies to the fourth use mode described below). This is to allow the cutting blade to penetrate the outer film so that the incision can be formed more reliably. Then, in this state, the cutting device (trolley part) is driven along the axial direction of the pipe (front and rear direction), and the cutting blade pressed against the outer film can form an incision in the axial direction of the pipe.

[0022] (d) Fourth Use

[0023] In order to form a circumferential incision on the outer film, the incision device is placed on the floor, for example, and the liner pipe is arranged so that the left and right directions of the incision device are aligned with the axial direction of the pipe and the liner pipe is placed on the cutting edge (see the following description). Figure 9 and Figure 10 ) Then, in this state, the inner liner tube is rotated around the tube axis, and a circumferential incision can be formed on the outer film by the cutting blade pressed against the outer film.

[0024] In the above-mentioned incision device of the present invention, as a more specific structure, one or any plurality of the following structures (1) to (5) can be adopted.

[0025] (1) The cutting blade is a disc-shaped rotating blade that is rotatably supported by a cutting blade support portion. The rotating blade allows the device to travel more smoothly and cut the coating. In addition, the rotating blade may include two rotating blades that are arranged in the left and right directions at a predetermined interval. According to this structure, during the incision operation, the cutting blade can be made to move stably without shaking or swaying left and right, thereby improving the workability. Furthermore, if the cutting blade can be made to move stably in this way, it is also possible to prevent the blade from being damaged due to, for example, a lateral force (a direction intersecting the blade) being applied to the cutting blade.

[0026] (2) The cutting blade support portion has a blade spacing adjustment mechanism for changing the spacing between the two rotating blades. According to this structure, the cutting blade can be more appropriately pressed (in a state close to perpendicular to the coating) in accordance with the tube diameter, for example, the blade spacing can be widened for a tube with a larger diameter, or reduced for a tube with a smaller diameter, etc., which can make it easier to form an incision on the coating, while reducing the lateral force (the direction intersecting the blade) applied to the cutting blade, thereby preventing damage to the blade.

[0027] (3) The carriage part has a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel as the wheels, and the cutting blade is arranged at a position closer to the center of the carriage part than the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel when viewed from the top and bottom. According to this structure, the cutting blade can be supported more reliably by the carriage part (in other words, the reaction force of the cutting blade pressing on the coating can be stably received by the carriage part), the carriage part (the present device) can be easily driven, and the workability can be improved.

[0028] (4) The cutting edge support portion has: a cylinder that supports the cutting edge in a manner capable of changing the position of the cutting edge in the vertical direction; a gas cylinder filled with gas for driving the cylinder; and a gas circuit that supplies the gas filled in the gas cylinder to the cylinder and switches the driving direction of the cylinder in the vertical direction. With this structure, there is no need to connect a power cord, a gas hose (compressor, gas piping), etc. to the device. Therefore, regardless of the work site, the incision operation can be performed with the device alone, and the incision operation can be effectively carried out without being interfered with (hindered) by the power supply and the hose. In addition, by adjusting the air pressure of the gas cylinder, an appropriate pressing force of the cutting edge against the object film can be obtained.

[0029] In addition, the above-mentioned "gas" does not merely refer to air. This "gas" is a concept that also includes various gases capable of driving the cylinder, and the gas filled in the gas cylinder can also be a gas other than air (such as carbon dioxide, etc.).

[0030] (5) The incision device has a rod-shaped handle bar for driving the carriage part. In order to drive the carriage part, other methods can also be adopted, such as towing with a steel wire rope or setting up a motor to make it travel by itself. Also, when moving or rotating the inner liner tube, a mechanism for driving the carriage part is not necessarily required. However, if the handle bar as described above is provided, the device (carriage part) can be moved forward and backward by pushing and pulling the handle bar. In addition, by lengthening the handle bar, the device can also reach the deep part of the pipe that cannot be reached by hand to perform the incision operation.

[0031] The typical incision forming device of the present invention has the structures of the above (1), (3), (4), and (5). In addition, the structure of the above (2) can also be provided in addition to these structures of (1), (3), (4), and (5).

[0032] According to the incision forming device of the present invention, while being able to perform the incision operation of the film safely and with good workability, an incision can be formed on either the inner film or the outer film and on either the axial direction or the circumferential direction of the pipe.

[0033] Other objects, features, and advantages of the present invention will become clear from the following description of the embodiments of the present invention based on the drawings. In addition, in each figure, the same reference numerals denote the same or corresponding parts. Description of the Drawings

[0034] Figure 1 is a perspective view showing an incision forming device according to an embodiment of the present invention.

[0035] Figure 2 is a front view showing an enlarged view of the support head (support portion of the cutting edge) of the incision forming device of the above embodiment.

[0036] Figure 3 is a side view showing a first usage mode of the incision forming device of the present embodiment (in the case of forming an incision in the axial direction of the tube on the inner film) by longitudinally (parallel to the tube axis) cutting the inner lining tube.

[0037] Figure 4 is a front view showing a first usage mode of the incision forming device of the present embodiment.

[0038] Figure 5 is a side view showing a second usage mode of the incision forming device of the present embodiment (in the case of forming an incision in the circumferential direction on the inner film) by longitudinally (parallel to the tube axis) cutting the inner lining tube.

[0039] Figure 6 is a front view showing a second usage mode of the incision forming device of the present embodiment.

[0040] Figure 7 is a side view showing a third usage mode of the incision forming device of the present embodiment (in the case of forming an incision in the axial direction of the tube on the outer film) by longitudinally (parallel to the tube axis) cutting the inner lining tube.

[0041] Figure 8 is a front view showing a third usage mode of the incision forming device of the present embodiment.

[0042] Figure 9 is a side view showing a fourth usage mode of the incision forming device of the present embodiment (in the case of forming an incision in the circumferential direction on the outer film) by longitudinally (parallel to the tube axis) cutting the inner lining tube.

[0043] Figure 10 is a front view showing a fourth usage mode of the incision forming device of the present embodiment.

[0044] Reference numerals

[0045] 1: Inner lining tube, 1a: Tube axis, 2: Tube body, 3: Film, 3a: Inner film, 3b: Outer film, 11: Incision forming device, 12: Trolley part, 12a: Trolley body, 13: Wheels, 13a: Left front wheel, 13b: Right front wheel, 13c: Left rear wheel, 13d: Right rear wheel, 14: Handle connecting part, 15: Handle rod, 16 (16a, 16b): Cutting edge, 17: Cutting edge support part, 18: Support head, 19: Cylinder, 19a: Cylinder body, 19b: Piston rod, 20: Gas cylinder, 21: Changeover valve, 22: Switch, 23a, 23b, 23c: Air pipes, 24: Gasket, G: Floor. Detailed description of the invention

[0046] will be described with reference toFigures 1 to 10 A description will be given of a notch forming device according to an embodiment of the present invention. In addition, in each figure, the orientation of the device is shown by appropriately displaying two-dimensional orthogonal coordinates or three-dimensional orthogonal coordinates representing the front, rear, left, right, up, and down directions.

[0047] As Figures 1 to 10 shown, a notch forming device 11 according to an embodiment of the present invention includes: a cutting edge 16 that can form a notch in the coating film 3 of the liner tube 1 having the coating film 3 formed on the surface (inner circumferential surface and outer circumferential surface) of the tube body 2; a cutting edge support portion 17 that supports the cutting edge 16 so as to be able to change the height position (position in the vertical direction); a carriage portion 12 that moves the cutting edge 16 together with the cutting edge support portion 17; and a handle bar 15 that operates (makes it travel) the carriage portion 12.

[0048] The carriage portion 12 has: a carriage main body 12a that is composed of a flat plate member having a rectangular planar shape; wheels 13 (left front wheel 13a, right front wheel 13b, left rear wheel 13c, and right rear wheel 13d) that are provided at the front, rear, left, and right of the carriage main body 12a (at the four corner portions of the carriage main body 12a) so as to be able to travel in the front-rear direction; and a handle connection portion 14 that is used to connect the handle bar 15 and can travel forward by pulling the handle bar 15 and travel backward by pushing the handle bar 15. In addition, the handle bar 15 is a rod-shaped member and can be disassembled and assembled with respect to the handle connection portion 14.

[0049] The cutting edge 16 is composed of two rotary blades 16a and 16b, and both of these two rotary blades 16a and 16b are supported so as to be able to rotate about a rotation axis extending in the left-right direction. These two cutting edges 16a and 16b are arranged in parallel with each other in the left-right direction and are arranged at the same height position. In addition, the interval between the two cutting edges 16a and 16b can be changed. For example, the number of arranged pieces of the washer 24 (refer to Figure 2 ) interposed between the support head 18 (described later) and each of the cutting edges 16a and 16b can be changed, or a washer having a different thickness can be replaced. Further, a plurality of support heads 18 having different intervals between the cutting edges 16a and 16b can be prepared for replacement therebetween.

[0050] The cutting edge support portion 17 that supports the cutting edge 16 on the upper side (above) of the bogie main body 12a has a support head 18 that rotatably supports the cutting edge 16, a cylinder 19 that changes the support position (height position) of the cutting edge 16 by moving the support head 18 in the vertical direction, a gas cylinder 20 filled with gas for driving the cylinder 19, and a gas circuit that connects the gas cylinder 20 and the cylinder 19. In addition, the support head 18 is provided at the upper end of the piston rod 19b of the cylinder 19. Further, the gas cylinder 20 is detachably provided on the bottom surface (lower surface) of the bogie main body 12a in a manner that allows it to be replaced when the gas is used up.

[0051] The cylinder 19 is a double-acting cylinder and has: a cylinder main body 19a including a cylinder barrel, a piston having a piston rod 19b and accommodated in the cylinder barrel, and supply and discharge ports (supply port and exhaust port) for supplying and discharging (supplying gas and exhausting gas) gas to and from the cylinder barrel.

[0052] The gas circuit is composed of a manual switching valve (direction switching valve) 21 that switches the air flow supplied from the gas cylinder 20 to the cylinder 19, a gas pipe (pipe) 23a that connects the gas cylinder 20 and the switching valve 21, and gas pipes (pipes) 23b, 23c that connect the switching valve 21 and the cylinder main body 19a (cylinder barrel). In order to switch the air flow, the switch 22 on the upper surface of the switching valve 21 is operated.

[0053] Specifically, when the switch 22 is turned to one side, gas is supplied from the gas cylinder 20 to the upper side of the piston in the cylinder barrel via the switching valve 21, and gas is discharged from the lower side of the piston in the cylinder barrel. As a result, the piston rod 19b contracts downward, causing the cutting edge 16 to move downward.

[0054] On the other hand, when the above-mentioned switch 22 is turned to the other side, gas is supplied from the gas cylinder 20 to the lower side of the piston in the cylinder barrel via the switching valve 21, and gas is discharged from the upper side of the piston in the cylinder barrel. As a result, the piston rod 19b extends upward, causing the cutting edge 16 to move upward. In addition, in the state where the cutting edge 16 is raised, the piston rod 19b (and thus the cutting edge 16 as well) is upwardly biased by the gas supplied to the cylinder barrel (lower side of the piston). As a result, the cutting edge 16 is pressed against the inner films 3a, 3b and the pipe wall (wall surface of the pipe main body 2) of the inner liner pipe 1.

[0055] By using the cutting device 11 of the present embodiment in the following first to fourth usage modes, axial incisions in the pipe axis direction and circumferential incisions in the pipe circumference direction can be formed in the inner film (inner film) 3a formed on the inner surface of the inner liner pipe 1 and the outer film (outer film) 3b formed on the outer surface, respectively.

[0056] (a) First usage mode

[0057] In order to form an axial incision in the inner film 3a, as Figure 3 and Figure 4As shown, the device 11 is arranged inside the pipe 1 in such a way that the front - rear direction of the device 11 coincides with the pipe axis direction (the extending direction of the pipe axis 1a). Further, when arranging the device 11 inside the pipe 1, after operating the switch 22 of the switching valve 21 to lower the cutting blade 16 downward, place the device 11 inside the pipe 1. Then, by operating the switch 22, raise the cutting blade 16 to press the cutting blade 16 against the inner surface of the pipe 1. Then, in this state, use the handle rod 15 to move the device 11 forward (in the direction of the arrow L) in such a way as to press it deep (backward) into the pipe 1. As the device 11 moves forward, the cutting blade 16 pressed against the inner surface of the pipe rotates (rotates while rolling on the inner surface of the pipe) and cuts the inner film 3a. Thus, the inner film 3a can be cut by the cutting blade 16 (16a, 16b), and a cut is formed in the inner film 3a in the direction of the pipe axis 1a.

[0058] In addition, after rotating the liner pipe 1 or the device 11 around the pipe axis 1a, by repeating the above - mentioned cutting operation, a plurality of (4, 6, 8 or more) cuts extending in the direction of the pipe axis 1a can be formed on the inner film 3a.

[0059] (b) Second usage mode

[0060] In order to form a cut in the inner film 3a in the circumferential direction of the pipe, as Figure 5 and Figure 6 shown, arrange the device 11 inside the pipe 1 in such a way that the left - right direction of the device 11 coincides with the pipe axis 1a direction. When arranging the device 11 inside the pipe 1, operate the switch 22 of the switching valve 21 to lower the cutting blade 16 as in the first usage mode, and after setting the device 11 inside the pipe 1, raise the cutting blade 16 to press the cutting blade 16 against the inner film 3a. In addition, in this usage mode, the handle rod 15 is removed. Then, in this state, rotate the liner pipe 1 around the pipe axis 1a (refer to the arrow R), and a cut can be formed in the inner film 3a in the circumferential direction of the pipe.

[0061] Further, when rotating the liner pipe 1, press the device 11 so that it does not rotate together with the liner pipe 1. Furthermore, as described above, for this cutting operation, it is sufficient for the liner pipe 1 and the device 11 to rotate relative to each other. A cut can also be formed when the device 11 travels (rotates) circumferentially along the pipe without rotating the liner pipe 1 (or when the pipe 1 and the device 11 rotate in opposite directions to each other).

[0062] (c) Third usage mode

[0063] In order to form a cut in the outer film 3b in the direction of the pipe axis 1a, as Figure 7 and Figure 8As shown, the cutting device 11 is placed on the floor G such that the longitudinal direction of the cutting device 11 is aligned with the direction of the pipe axis 1a, and the inner liner tube 1 is arranged in a manner that it is placed on the cutting edge 16. At this time, a part or all of the dead weight of the inner liner tube 1 can be applied to the cutting device 11 (cutting edge 16) (the same applies to the fourth usage mode described below). This is to enable the cutting edge 16 to penetrate the outer coating film 3b so that a cut can be formed more reliably. Then, if the device 11 is moved in the direction of the pipe axis 1a in this state, the outer coating film 3b is cut by the cutting edge 16 pressed against the outer surface of the pipe, and a cut in the direction of the pipe axis 1a can be formed on the outer coating film 3b.

[0064] In addition, as in the first usage mode described above, after rotating the inner liner tube 1 around the pipe axis 1a, by repeating the above cutting operation, a plurality of (4, 6, 8 or more) cuts extending in the direction of the pipe axis 1a can be formed on the outer coating film 3b.

[0065] (d) Fourth usage mode

[0066] To form a cut in the circumferential direction of the outer coating film 3b, as Figure 9 and Figure 10 shown, the device 11 is placed on the floor G, and the inner liner tube 1 is arranged in a manner that the left - right direction of the device 11 is aligned with the direction of the pipe axis 1a and it is placed on the cutting edge 16. Then, by rotating the inner liner tube 1 around the pipe axis 1a in this state, a cut in the circumferential direction of the outer coating film 3b can be formed by the cutting edge 16 pressed against the outer surface of the pipe.

Claims

1. An incision forming device, characterized in that: have: a cutting blade that forms an incision in the coating of the liner pipe; A carriage portion having wheels at the front, rear, left and right sides and capable of traveling in the front-rear direction; as well as The cutting blade support portion supports the cutting blade at an upper position of the carriage portion so that the support height can be changed and applies force upward.

2. The incision forming device according to claim 1, characterized in that: The cutting blade is a disk-shaped rotating blade rotatably supported by the cutting blade support portion.

3. The incision forming device according to claim 2, characterized in that: The rotating blades include two rotating blades arranged in the left-right direction at a predetermined interval.

4. The incision forming device according to claim 2, characterized in that: The cutting blade support portion includes a blade spacing adjustment mechanism for changing the spacing between the two rotating blades.

5. The incision forming device according to claim 1, characterized in that: The carriage portion has a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel as the wheels. The cutting blade is disposed at a position closer to the center of the carriage portion than the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel when viewed from the top and bottom.

6. The incision forming device according to claim 1, characterized in that: The cutting blade support portion has: a cylinder supporting the cutting blade in such a manner that the arrangement position of the cutting blade in the vertical direction can be changed; a gas cylinder filled with gas for driving the gas cylinder; and A gas circuit supplies the gas filled in the gas cylinder to the gas cylinder and switches the driving direction of the gas cylinder in the up and down directions.

7. The incision forming device according to any one of claims 1 to 6, characterized in that: A rod-shaped handlebar is provided for moving the carriage portion.

8. The incision forming device according to claim 3 or 4, characterized in that: The carriage portion has a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel as the wheels. When viewed from the top and bottom direction, the cutting blade is arranged at a position closer to the center of the carriage portion than the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel. The cutting blade support portion has: a cylinder supporting the cutting blade in such a manner that the arrangement position of the cutting blade in the vertical direction can be changed; a gas cylinder filled with gas for driving the gas cylinder; and a gas circuit that supplies the gas filled in the gas cylinder to the gas cylinder and switches the driving direction of the gas cylinder in the up and down directions, The incision forming device includes a rod-shaped handle bar for moving the carriage portion.

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