JP7701840B2 - cutting device - Google Patents

Description

The present invention relates to a cutting device.

In composite girders in which the steel girder and the concrete deck are joined together with anti-slip devices to form an integrated structure, when replacing the concrete deck of the composite girder, the concrete deck may be cut parallel to the steel girder using a cutting device equipped with a loop-shaped wire saw and removed (see, for example, Patent Documents 1 and 2).

JP 2019-31868 A JP 2009-114688 A

When cutting a concrete deck with a wire saw, if the wire saw becomes loose, the cutting position will be unstable and there is a risk of damaging the steel girders. For this reason, the concrete deck is cut with a wire saw at a position that is spaced apart from the steel girders with a margin of error, that is, at a position above the top surface of the steel girders.
Furthermore, when removing a concrete deck, the portion above the cutting position must first be removed, and then the portion below must be chipped away with a chipping hammer or water jet, which poses the problem that this chipping work takes time and effort.

The present invention aims to provide a cutting device that can reduce slack in the wire saw and reduce deviation in the cutting position.

In order to achieve the above object, a cutting device according to the present invention has a cutting unit that cuts concrete members, and a moving unit that moves the cutting unit in a front-to-rear direction , the cutting unit having an endless loop-shaped wire saw that cuts the concrete members, and a plurality of drive pulleys around which the wire saw is wound to rotate the wire saw, the plurality of drive pulleys rotate in synchronization with each other at the same rotation speed, the plurality of drive pulleys each have a rotation axis that extends in the front-to-rear direction , are arranged at an interval in a horizontal direction that intersects the front-to-rear direction , and include two drive pulleys around which the wire saw is wound, and the two drive pulleys The wire saw further comprises an auxiliary pulley that is positioned between the drive pulleys at a position lower than the rotation axes of the two drive pulleys and around which the wire saw moving between the two drive pulleys is wound, and a drive pulley moving unit that moves the two drive pulleys in an up and down direction to move a concrete cutting portion of the wire saw that cuts the concrete member in the up and down direction , and cuts the concrete member by performing at least one of moving the cutting portion in the forward and backward direction with the moving unit and moving the two drive pulleys in the up and down direction with the drive pulley moving unit.

In the present invention, the wire saw is wound around a plurality of drive pulleys, and the wire saw is sent out by at least one of the plurality of drive pulleys and wound up by the other drive pulleys. The plurality of drive pulleys rotate in synchronization with each other at the same rotation speed, so that the force with which the drive pulleys send out the wire saw and the force with which the wire saw is wound up are equal in magnitude. This makes it possible to suppress slack in the wire saw and to suppress deviation in the cutting position.
The cutting device according to the present invention further includes a drive pulley moving section that moves the two drive pulleys in a horizontal direction intersecting the front-rear direction .
With this configuration, the two drive pulleys can be moved horizontally in a direction intersecting the front-to-rear direction , and the wire saw can also be moved in this direction, allowing the concrete material to be cut in the horizontal direction intersecting the front-to-rear direction.

In addition, in the cutting device according to the present invention, the moving part may have a rail and a platform that supports the cutting part and can run on the rail.

This configuration allows the cutting section supported by the stand to move along the rails, reducing deviation in the cutting position.

In addition, in the cutting device according to the present invention, the moving unit may have a plurality of running rollers attached to the frame and running on the rail, and a motor for rotating each of the plurality of running rollers, and the plurality of running rollers may be configured to rotate in synchronization with each other at the same rotation speed.

This configuration prevents the platform from wobbling as it runs on the rails, minimizing wobble at the cutting position.

In addition, in the cutting device according to the present invention, the rail may be installed on the concrete member.

This configuration allows the rails to be installed easily. Workers do not need to get under the concrete to install the rails, so they can work safely.

In addition, in the cutting device according to the present invention, the stand may be provided with at least one of a safety protection sheet that covers the cutting section and a protective sheet that prevents the scattering of dust and cutting process water during cutting.

With this configuration, the safety protection sheet and curing sheet move along with the stand to match the cut location of the concrete member, eliminating the need to cover the entire concrete member with the safety protection sheet or curing sheet, reducing the labor required for installing and removing the safety protection sheet and curing sheet.

The cutting device according to the present invention may also have a pair of movable pulleys around which the wire saw is wound, each of which is provided on either side of the cutting portion of the wire saw that cuts the concrete member, and the pair of movable pulleys may be capable of adjusting the position of the cutting portion relative to the drive pulley in the direction of movement of the cutting portion.

With this configuration, the cutting portion of the wire saw can be positioned in front of and behind the drive pulley in the direction of movement of the cutting portion. Therefore, if the moving portion can move the cutting portion forward and backward, by positioning the cutting position of the wire saw at a position behind the driving pulley in the direction of movement, the concrete member can be cut whether the cutting portion is moved forward or backward.
can.

The present invention can reduce slack in the wire saw and thus reduce deviation in the cutting position.

FIG. 1 is a front view of a cutting device according to a first embodiment. FIG. 2 is a side view of the cutting device according to the first embodiment. FIG. FIG. FIG. FIG. 11 is a front view of a cutting device according to a second embodiment.

First Embodiment
A cutting device 1 according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 5. FIG.
As shown in Fig. 1, the cutting device 1 according to the first embodiment is used to cut a concrete slab 22 when removing the concrete slab 22 from a composite girder 2 in which a steel girder 21 and a concrete slab 22 (concrete member) are joined together by a shear stopper 23 and integrated with each other. In Fig. 1, the range in which the shear stopper is provided is indicated by reference numeral 23. Hereinafter, the direction in which the composite girder 2 extends is referred to as the girder length direction (the direction of arrow A in the figure, the direction perpendicular to the paper surface in Fig. 1). In this embodiment, the girder length direction is approximately horizontal. The horizontal direction perpendicular to the girder length direction is referred to as the girder width direction (the direction of arrow B in the figure).

The concrete floor slab 22 is provided on top of the steel girder 21 that extends in the girder length direction. The concrete floor slab 22 is formed in the shape of a long plate that extends in the girder length direction. The portion of the concrete floor slab 22 directly above the steel girder 21 protrudes downward from the portions on both sides of that portion in the girder width direction and is joined to the steel girder 21. The portion of the concrete floor slab 22 that protrudes downward and is joined to the steel girder 21 is the steel girder joint 24. A shear stopper 23 is arranged in the steel girder joint 24. The upper side of the steel girder joint 24 in the concrete floor slab 22 is the flat plate portion 25.

The cutting device 1 cuts the steel girder joint 24 together with the shear stopper 23 at a position above the top surface of the steel girder 21. The shear stopper 23 has its lower end joined to the steel girder 21 and its upper end positioned above the cutting position 26 by the cutting device 1. The portion 27 of the concrete deck 22 below the cutting position 26 by the cutting device 1 is chipped off and removed with a chipping hammer, water jet, or the like.

The cutting device 1 has a cutting unit 3 that cuts the concrete floor slab 22 and a moving unit 4 that moves the cutting unit 3. The cutting unit 3 cuts the concrete floor slab 22 from the girder width direction at a position above the top surface of the steel girder 21. The moving unit 4 moves the cutting unit 3 in the girder length direction. The cutting device 1 cuts the concrete floor slab 22 in the girder length direction by having the moving unit 4 move the cutting unit 3, which cuts the concrete floor slab 22 from the girder width direction, in the girder length direction.

As shown in Figures 1 to 3, the moving unit 4 has a pair of rails 41, 41 installed on the concrete slab 22 to be cut, a stand 42 that supports the cutting unit 3, a number of running rollers 43 that are provided on the stand 42 and run on the rails 41, and a motor 44 (see Figures 2 and 3) connected to the running rollers 43. Details of the stand 42, the running rollers 43, and the motor 44 are shown in Figures 4 and 5.

The pair of rails 41, 41 are installed in a direction extending in the girder length direction. The pair of rails 41, 41 are anchored to the concrete floor slab 22. Each of the pair of rails 41, 41 is formed with a hole 411 (see FIG. 3 ) through which an anchor is inserted.
The platform 42 is movable in the girder length direction along the rails 41. The platform 42 will be described in detail later.

1 and 2, the cutting unit 3 has an endless loop-shaped wire saw 31 that cuts the concrete floor slab 22, two drive pulleys 32, 33 (a plurality of drive pulleys 32, 33) around which the wire saw 31 is wound to rotate the wire saw 31, and a plurality of auxiliary pulleys 34 that guide the rotating wire saw 31. In Fig. 1, the wire saw 31 is indicated by a dashed line.
The two drive pulleys 32 and 33 and the multiple auxiliary pulleys 34 are each supported by a frame 42 .

The two drive pulleys 32, 33 are each disposed above the frame 42. That is, the two drive pulleys 32, 33 are each disposed above the concrete floor slab 22. The two drive pulleys 32, 33 have the same diameter and are disposed at a distance in the girder width direction with their axes extending in the girder length direction.

The wire saw 31 is arranged above and below the concrete slab 22. The wire saw 31 is wound around two drive pulleys 32, 33 above the concrete slab 22, and extends downward from both sides of the two drive pulleys 32, 33 in the girder width direction, penetrating the concrete slab 22 or passing through the sides of the concrete slab 22, and extends in the girder width direction below the flat plate portion 25 of the concrete slab 22. The portion of the wire saw 31 extending in the girder width direction below the flat plate portion 25 penetrates the steel girder joint 24 of the concrete slab 22 in the girder width direction. The wire saw 31 moves in the girder length direction while rotating along its loop, so that the portion penetrating the steel girder joint 24 cuts the steel girder joint 24 in the girder length direction. The portion of the wire saw 31 extending in the girder width direction below the flat plate portion 25 of the wire saw 31 is the wire saw cutting portion 311 (see FIG. 1).

The wire saw 31, which is rotated by the drive of two drive pulleys 32, 33, moves from one side to the other in the girder width direction above the concrete floor slab 22, and moves from the other side to one side in the girder width direction below the concrete floor slab 22. The wire saw 31 moves from the top to the bottom on one side of the girder width direction, and moves from the bottom to the top on the other side of the girder width direction.

An auxiliary pulley 34 is provided at a portion that switches the direction of feeding the wire saw 31 that rotates in a loop shape. In this embodiment, free pulleys 35, 35 are provided on both sides of the steel girder joint 24 in the girder width direction. A wire saw cutting portion 311 is provided between the two free pulleys 35, 35 that are provided on either side of the steel girder joint 24.

As shown in FIG. 2, the swivel pulley 35 rotates about a first axis 351 that passes through its center, and is supported so as to be rotatable 360° about a second axis 352 that intersects with the first axis 351. In this embodiment, the swivel pulley 35 is oriented so that the second axis 352 extends vertically and the first axis always extends horizontally.

The wire saw 31 extends vertically above the movable pulley 35, and extends horizontally below the movable pulley 35. Because the movable pulley 35 is supported so as to be rotatable 360° about the second axis, the portion of the wire saw 31 below the movable pulley 35, i.e., the wire saw cutting portion 311, can be oriented to extend in any direction along the horizontal plane.

Returning to FIG. 1, of the two drive pulleys 32, 33, the drive pulley 32 arranged on one side in the girder width direction is referred to as the first drive pulley 32, and the drive pulley 33 arranged on the other side in the girder width direction is referred to as the second drive pulley 33. The first drive pulley 32 and the second drive pulley 33 have the same shape and are controlled to have the same rotation speed and are synchronized. In this embodiment, the first drive pulley 32 and the second drive pulley 33 are each connected to a different motor (not shown). Each motor is connected to a different hydraulic unit. In this embodiment, the first drive pulley 32 and the second drive pulley 33 can be operated so as to be synchronized with each other using one operation box.

As described above, above the concrete slab 22, the wire saw 31 moves from one side to the other side in the girder width direction. In detail, the wire saw 31 is sent out to the first driving pulley 32 and moves downward, then changes direction at the auxiliary pulley 34 to move to the other side in the girder width direction, changes direction at the auxiliary pulley 34 to move upward, and reaches the second driving pulley 33. When the wire saw 31 reaches the second driving pulley 33, it is sent out to the second driving pulley 33 and moves toward the underside of the concrete slab 22, changes direction at the auxiliary pulley 34 to move toward one side in the girder width direction, and passes through the swivel pulley 35 to cut the steel girder joint 24. The wire saw 31 cuts the steel girder joint 24 below the concrete slab 22, and when it passes through the swivel pulley 35 and reaches the first driving pulley 32 again, it is pulled back by the first driving pulley 32 to reach the first driving pulley 32.

As described above, the first drive pulley 32 and the second drive pulley 33 are controlled so that their respective rotation speeds are the same and synchronized. This makes the force with which the second drive pulley 33 sends out the wire saw 31 the same as the force with which the first drive pulley 32 pulls back the wire saw 31. As a result, the wire saw 31 is in a taut state, and slackness is suppressed.

As shown in Figures 1 and 3, the frame 42 has a first frame 421, a second frame 422, a connecting portion 423 that connects the first frame 421 and the second frame 422, and a drive pulley support portion 45 (see Figure 1) that supports the first drive pulley 32 and the second drive pulley 33.

The first frame 421 runs along one of the pair of rails 41, 41, and the second frame 422 runs along the other rail 41. Running rollers 43 are provided on both the first frame 421 and the second frame 422. The running rollers 43 provided on the first frame 421 and running along one of the rails 41 are referred to as first running rollers 431, and the running rollers 43 provided on the second frame 422 and running along the other rail 41 are referred to as second running rollers 432.

The first running roller 431 and the second running roller 432 are each connected to a different motor 44. The first running roller 431 and the second running roller 432 are controlled to rotate in unison. In this embodiment, it is possible to control the rotation of the first running roller 431 and the second running roller 432 to be synchronized with the rotation of the first driving pulley 32 and the second driving pulley 33.

The connecting portion 423 connects the first frame 421 and the second frame 422 to match the gap between the pair of rails 41, 41. The connecting portion 423 may have an adjuster function that adjusts the gap between the first frame 421 and the second frame 422. The first frame 421 and the second frame 422 may be configured so that they can be connected to each other by a plurality of connecting portions 423 of different lengths. In this way, the first frame 421 and the second frame 422 may be connected to each other by the connecting portion 423 selected to match the gap between the rails 41, 41.

The drive pulley support section 45 has a first pole 451 erected on the first frame 421, a second pole 452 erected on the second frame 422, a first drive pulley lifting section 453 (drive pulley moving section) to which the first drive pulley 32 is attached and which can move up and down along the first pole 451, and a second drive pulley lifting section 454 (drive pulley moving section) to which the second drive pulley 33 is attached and which can move up and down along the second pole 452.

The first drive pulley lifting section 453 and the second drive pulley lifting section 454 are arranged so that the first drive pulley 32 and the second drive pulley 33 are at the same height. As described above, the first drive pulley 32 and the second drive pulley 33 are installed with their axes extending in the girder length direction. When the first drive pulley lifting section 453 and the second drive pulley lifting section 454 are raised and lowered, and the first drive pulley 32 and the second drive pulley 33 are raised and lowered, the wire saw 31 wound around the first drive pulley 32 and the second drive pulley 33 is raised and lowered. When the wire saw 31 is raised and the wire saw cutting portion 311 that cuts the steel girder joint 24 is also raised and lowered, it is possible to move the steel girder joint 24 and the flat plate portion 25 of the concrete floor slab 22 upward and cut them vertically. The first drive pulley lifting unit 453 and the second drive pulley lifting unit 454 are raised and lowered, for example, by driving a hydraulic motor.

The stand 42 is provided with a safety protection sheet 51 and a protective sheet 52 that cover the cutting section 3. The safety protection sheet 51 and the protective sheet 52 are fixed to the stand 42 and the first pole 451 and the second pole 452 of the drive pulley support section 45. The stand 42 may be provided with mounting members for attaching the safety protection sheet 51 and the protective sheet 52.

The stand 42 may be provided with a dust collector for collecting dust generated when cutting the concrete deck 22 in a dry manner, a water injection means when cutting in a wet manner, and the like. The dust collector and the water injection means are suspended and supported by the stand 42 so that they can be positioned, for example, near the steel girder joint 24 of the concrete deck 22.

Next, a method for removing the concrete deck 22 from the composite girder 2 will be described.
A pair of rails 41, 41 are installed on the concrete floor slab 22. A stand 42, two drive pulleys 32, 33 and an auxiliary pulley 34 are installed on the pair of rails 41, 41, and a wire saw 31 is installed.
When installing the wire saw 31, a hole 241 extending in the girder width direction is formed in the steel girder joint 24 of the concrete deck 22. The wire saw 31 is passed through the hole 241 and wound around two drive pulleys 32, 33. In this embodiment, the hole 241 is formed 2 cm or more above the top surface of the steel girder 21. The position at which the hole 241 is formed may be set appropriately.

The two drive pulleys 32, 33 are rotated in unison, and the traveling roller 43 is rotated in unison to cause the base 42 to travel in the girder length direction. When the base 42 moves from one side to the other in the girder length direction, the wire saw cutting part 311 also moves from one side to the other in the girder length direction as if pulled by the drive pulleys 32, 33 of the base 42. At this time, the swivel pulleys 35 provided on both sides of the wire saw cutting part 311 rotate about the second axis so that the wire saw cutting part 311 is on the rear side of the swivel pulleys 35 (on one side in the girder length direction).
In contrast, when the stand 42 moves from the other side to one side in the girder length direction, the wire saw cutting part 311 also moves from the other side to one side in the girder length direction as if pulled by the stand 42. At this time, the swivel pulley rotates about the second axis so that the wire saw cutting part 311 is on the rear side of the swivel pulley 35 (the other side in the girder length direction).

After the cutting unit 3 has been moved to a predetermined position, the first drive pulley 32 and the second drive pulley 33 are raised by the first drive pulley lifting unit 453 and the second drive pulley lifting unit 454, and the concrete floor slab 22 is cut upward by the wire saw cutting part 311. When the wire saw 31 has moved above the concrete floor slab 22, the cut concrete floor slab 22 is removed.

The remaining portion of the concrete deck 22, i.e., the portion 27 below the cutting position 26 by the cutting device 1, is chipped off and removed using a chipping hammer or water jet.

Next, the operation and effect of the cutting device 1 according to the first embodiment will be described.
In the cutting device 1 according to the above embodiment, the wire saw 31 is wound around the first drive pulley 32 and the second drive pulley 33, so that the wire saw 31 is sent out by the second drive pulley 33 and taken up by the first drive pulley 32. The first drive pulley 32 and the second drive pulley 33 rotate in synchronization with each other at the same rotation speed, so that the force with which the second drive pulley 33 sends out the wire saw 31 and the force with which the first drive pulley 32 takes up the wire saw 31 are the same. This makes it possible to suppress slack in the wire saw 31 and to suppress deviation of the cutting position 26. In other words, the cutting accuracy is improved.
As a result, the cutting position 26 can be located closer to the steel girder 21, so that the portion 27 below the cutting position 26 is reduced, and the amount of chipping work for the portion 27 below the cutting position 26 can be reduced.
Furthermore, by providing two drive pulleys 32, 33, the rotation speed can be increased, and therefore the construction speed can be increased.

In the cutting device 1 according to the above embodiment, the moving unit 4 has the rails 41 and the platform 42 that supports the cutting unit 3 and is capable of traveling on the rails 41 .
With this configuration, the cutting unit 3 supported by the stand 42 can be moved along the rails 41, so that deviation of the cutting position 26 can be suppressed.

In the cutting device 1 according to the above embodiment, the moving unit 4 has a plurality of running rollers 43 attached to a frame 42 and running on a rail 41, and a motor 44 for rotating each of the plurality of running rollers 43, and the plurality of running rollers 43 rotate in synchronization with each other at the same rotational speed.
With this configuration, the platform 42 running on the rails 41 does not wobble, so that wobble of the cutting position 26 can be suppressed.

In the cutting device 1 according to the above embodiment, the rail is installed on the concrete floor slab 22 .
With this configuration, the rails can be easily installed. Since workers do not need to enter under the concrete slab 22 to install the rails, the work can be done safely.

In the cutting device 1 according to the above embodiment, the stand 42 is provided with a safety protection sheet 51 and a protective sheet 52 for covering the cutting unit 3 .
With this configuration, the safety protection sheet 51 and the curing sheet 52 move together with the stand 42 to match the cut location of the concrete floor slab 22, so there is no need to cover the entire concrete floor slab 22 with the safety protection sheet 51 or the curing sheet 52, reducing the effort required to install and remove the safety protection sheet 51 and the curing sheet 52.

In the cutting device 1 according to the above embodiment, the swivel pulleys 35 are provided on both sides of the wire saw cutting portion 311 .
With this configuration, the wire saw cutting portion 311 can be disposed on the front and rear sides of the driving pulleys 32, 33 in the movement direction (one side and the other side in the girder length direction). Therefore, the concrete floor slab 22 can be cut whether the cutting unit 3 is moved to one side in the girder length direction by advancing the platform 42 or to the other side in the girder length direction. In other words, it is possible to cut the concrete floor slab 22 while moving the cutting unit 3 back and forth in the girder length direction.

The cutting device 1 according to the above embodiment has the first drive pulley lifting section 453 and the second drive pulley lifting section 454 which move the first drive pulley 32 and the second drive pulley 33 in the up and down direction.
With this configuration, the first drive pulley 32 and the second drive pulley 33 are moved in the vertical direction, and the wire saw cutting part 311 is also moved in the vertical direction, so that the concrete floor slab 22 can be cut not only in the girder length direction but also in the vertical direction. In addition, by moving the wire saw cutting part 311 in the vertical direction while moving it in the girder length direction, it can also be cut in an oblique direction.

Second Embodiment
Next, another embodiment will be described with reference to the attached drawings. The same or similar members and parts as those in the first embodiment described above will be designated by the same reference numerals, and their description will be omitted. Configurations different from the embodiment will be described.
As shown in Fig. 6, the cutting device 1B according to the second embodiment is configured to be able to simultaneously cut two steel girder joints 24, 24 that are spaced apart in the girder width direction. Of the two steel girder joints 24, 24, the steel girder joint 24 on one side in the girder width direction is referred to as a first steel girder joint 242, and the steel girder joint 24 on the other side is referred to as a second steel girder joint 243.

In the second embodiment, similarly to the first embodiment, two drive pulleys 32 and 33 are provided, and the two drive pulleys 32 and 33 rotate in synchronization with each other at the same rotation speed.
In the second embodiment, the wire saw 31 is disposed longer in the girder width direction than in the first embodiment. For this reason, an auxiliary pulley 341 around which the wire saw 31 is wound is provided between a portion of the wire saw 31 that cuts the first steel girder joint 242 and a portion of the wire saw 31 that cuts the second steel girder joint 243.
In the second embodiment, a groove 221 that penetrates in the vertical direction and extends in the girder length direction is provided in a portion between a first steel girder joint 242 and a second steel girder joint 243 in the flat plate portion 25 of the concrete floor slab 22. The auxiliary pulley 341 penetrates the groove 221 and is installed at the lower part of a pole 342 whose upper part is fixed to the frame 42.

In the second embodiment, the swivel pulleys 35 are arranged on both sides of the first steel girder joint 242 and the second steel girder joint 243 in the girder width direction. In the second embodiment, four swivel pulleys 35 are provided.

The cutting device 1B according to the second embodiment described above has the same effects as the first embodiment.
Furthermore, the cutting device 1B according to the second embodiment can simultaneously cut the concrete slab 22 joined to two steel girders 21. When cutting the concrete slab 22 for each steel girder joint 24 (steel girder 21), it is necessary to provide shoring in the portion where the concrete slab 22 was previously cut. In this embodiment, since multiple steel girder joints 24 arranged at intervals in the girder width direction can be simultaneously cut, there is no need to provide shoring, and the labor, time, and cost required for installing shoring can be reduced.

Although the embodiment of the cutting device according to the present invention has been described above, the present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the spirit of the present invention.
For example, in the above embodiment, the cutting device 1 is provided with two drive pulleys 32, 33. The cutting device 1 may be provided with two or more drive pulleys 32, 33.
In the above embodiment, the drive pulleys 32, 33 are arranged so that the rotation axis extends in the girder length direction (vertical placement). The drive pulleys 32, 33 may be arranged so that the rotation axis extends in the vertical direction (horizontal placement).

In the cutting device 1 according to the above embodiment, the moving unit 4 has rails and a platform 42 that supports the cutting unit 3 and can run on the rails. The form of the moving unit 4 that moves the cutting unit 3 may be other than that described above. When rails are installed, the number, form, and installation position of the rails may be set appropriately.

In the cutting device 1 according to the above embodiment, the moving unit 4 has a plurality of running rollers 43 attached to a stand 42 and running on rails, and a motor 44 that rotates each of the plurality of running rollers 43, and the plurality of running rollers 43 rotate in synchronization with each other at the same rotation speed. The number of running rollers 43 and the control of the running rollers 43 may be set appropriately.

In the cutting device 1 according to the above embodiment, the stand 42 is provided with a safety protection sheet 51 and a protective sheet 52 that cover the cutting section 3. The safety protection sheet 51 and the protective sheet 52 may be provided on a part other than the stand 4, such as the composite girder 2. Also, one of the safety protection sheet 51 and the protective sheet 52 may be provided on the stand 42, and the other may be provided on a part other than the stand 4, such as the composite girder 2.

In the cutting device 1 according to the above embodiment, a pair of movable pulleys 35 is provided, and the wire saw 31 is configured to cut the concrete floor slab 22 whether the platform 42 moves forward or backward. In contrast, the cutting device 1 does not have to be provided with a pair of movable pulleys 35 as described above. The cutting device 1 may be configured to cut the concrete floor slab 22 only when moving in one direction.

In the cutting device 1 according to the above embodiment, a first drive pulley lifting section 453 and a second drive pulley lifting section 454 are provided to move the first drive pulley 32 and the second drive pulley 33 in the up and down direction. The first drive pulley lifting section 453 and the second drive pulley lifting section 454 may not be provided, and the first drive pulley 32 and the second drive pulley 33 may be configured to lift and lower.

In the second embodiment described above, two steel girder joints 24 arranged in the girder width direction are cut simultaneously, but three or more steel girder joints 24 arranged in the girder width direction may be cut simultaneously.

The cutting devices 1 and 1B in the above embodiment horizontally cut the concrete floor slab 22 of the composite girder 2. In contrast, the cutting devices 1 and 1B may be used when cutting concrete members other than the concrete floor slab 22 or when cutting concrete members in a direction other than horizontal.

1, 1B Cutting device 3 Cutting section 4 Moving section 22 Concrete floor slab (concrete member)
24 Steel girder joint 31 Wire saw 32, 33 Drive pulley 35 Free pulley 41 Rail 42 Frame 43 Travel roller 44 Motor 46 Drive pulley moving part 51 Safety protection sheet 52 Covering sheet 311 Wire saw cutting part

Claims (6)

A cutting unit that cuts the concrete member;
A moving unit that moves the cutting unit in a front-rear direction ,
The cutting portion is
An endless loop wire saw for cutting the concrete member;
a plurality of drive pulleys around which the wire saw is wound to rotate the wire saw;
The plurality of drive pulleys rotate in synchronization with each other at the same rotation speed,
The plurality of drive pulleys each include two drive pulleys whose rotation axes extend in the front-rear direction , which are arranged at an interval in a horizontal direction intersecting the front-rear direction , and around which the wire saw is wound,
an auxiliary pulley arranged between the two drive pulleys and below the rotation axes of the two drive pulleys, and around which the wire saw moving between the two drive pulleys is wound;
A drive pulley moving unit that moves the two drive pulleys in an up-down direction to move a concrete cutting portion of the wire saw that cuts the concrete member in the up-down direction ,
A cutting device that cuts the concrete member while performing at least one of the following: moving the cutting section in the forward /backward direction using the moving section; and moving the two drive pulleys in the upward/downward direction using the drive pulley moving section. The moving unit is
Rails and
The cutting device according to claim 1 , further comprising: a platform that supports the cutting portion and is capable of running on the rails. The moving unit is
A plurality of running rollers attached to the frame and running on the rail;
a motor for rotating each of the plurality of traveling rollers,
3. The cutting device according to claim 2, wherein the plurality of traveling rollers rotate synchronously at the same rotation speed. The cutting device according to claim 2 or 3, wherein the rail is installed on the concrete member. The cutting device according to any one of claims 2 to 4, wherein the stand is provided with at least one of a safety protection sheet that covers the cutting section and a protective sheet that prevents the scattering of dust and cutting process water during cutting. The wire saw has a pulley around which the wire saw is wound, the pulley being provided on each side of a cutting portion of the wire saw that cuts the concrete member,
The cutting device according to claim 1 , wherein the swivel pulley is capable of adjusting the position of the cutting portion relative to the drive pulley in a moving direction of the cutting portion.

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