Cutter unit, joint cutting device and joint cutting method

Abstract

To provide a cutter unit, a joint cutting device, and a joint cutting method capable of making the width of a joint substantially constant even if the joint is cut in uncured concrete.SOLUTION: A cutter unit 500 has a base member 510, a disk-shaped cutter 520 rotatably mounted thereon, an electric motor 530 that rotationally drives the cutter, and a pair of crawlers 550 that contact with the surface of a concrete pavement CP on both sides of the plate surface of the cutter 520. Further, the joint cutting device 100 has a frame 200 and a cutter unit 500 movable along a frame 200. Then, using the cutter unit 500 or the joint cutting device 100, the cutter unit 500 is moved while rotationally driving the cutter 520, and the joint is cut while pressing the surfaces of the concrete pavement CP on both sides of the cutter 520 with the pair of crawlers 550.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a cutter unit, a joint cutting device, and a joint cutting method for cutting joints in poured concrete. [Background technology]

[0002] In concrete pavements and the like, concrete expands and contracts due to temperature changes, so joints are cut to prevent cracks caused by this expansion and contraction. To cut such joints, a joint cutting device such as that described in JP 2016-94779 A (Patent Document 1) has been proposed. The joint cutting device proposed in Patent Document 1 includes a rail extending in the width direction of the road, a cutter support that is movable along the rail, a disk-shaped cutter that is rotatably mounted on the cutter support, and an actuator that rotates the cutter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-94779 Summary of the Invention [Problem to be solved by the invention]

[0004] In road replacement work, for example, it is necessary to open the road to traffic as early as possible to minimize traffic congestion. For this reason, it is necessary to cut the joints in the poured concrete while it is still unhardened. However, when cutting the concrete surface with a rotating cutter, the width of the joints is not uniform because the concrete is still unhardened, which can result in a deterioration in the quality of the concrete pavement where the joints have been cut.

[0005] Therefore, an object of the present invention is to provide a cutter unit, a joint cutting device, and a joint cutting method that ensure that the width of the joint remains approximately constant even when cutting joints in unhardened concrete pavement. [Means for solving the problem]

[0006] The cutter unit has a base member, a disc-shaped cutter rotatably attached to the base member, an actuator that rotates the cutter, and a pair of crawlers that are arranged on either side of the cutter's plate surface and come into contact with the surface of the concrete to be jointed. Here, the outer peripheral surfaces of the pair of crawlers are formed in a flat shape. Using such a cutter unit, the cutter is rotated by an actuator while the cutter unit is moved, and the concrete surface located on both sides of the cutter is pressed down by a pair of crawlers to cut the joints.

[0007] The joint cutting device has a frame and a cutter unit that is arranged to be movable along the frame. Using this joint cutting device, the cutter unit is moved along the frame while the cutter is rotated by the cutter unit's actuator, and the joint is cut while the pair of crawlers presses down on the concrete surface on both sides of the cutter. [Effects of the Invention]

[0008] According to the present invention, even when joints are cut in unhardened concrete, the width of the joints can be made substantially constant. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view showing an example of a jointing device. [Figure 2] FIG. 2 is a front view showing an example of a jointing device. [Figure 3] FIG. 2 is a side view showing an example of a jointing device. [Figure 4] FIG. 2 is a plan view showing an example of a cutter unit as viewed from below. [Figure 5] FIG. 2 is a side view showing an example of a cutter unit. [Figure 6] FIG. 2 is a plan view showing an example of a crawler box containing a pair of crawlers. [Figure 7] FIG. 10 is a side view showing an example of the cutter unit in the initial state of the crawler box. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 show an example of a joint cutting device 100 that cuts joints in poured concrete. It goes without saying that the joint cutting device 100 described below is merely an example and can be modified as appropriate within the scope of the technical concept of this embodiment. Therefore, it should be noted that the present invention is not limited to the following embodiment.

[0011] The joint cutting device 100 includes a frame 200, a height changing mechanism 300, a self-propelled mechanism 400, a cutter unit 500, a control panel 600, and a working passage 700.

[0012] The frame 200 includes a pair of horizontal members 210 made of elongated steel pipes or the like, and a pair of connecting members 220 made of steel pipes or the like that extend vertically from both ends of the pair of horizontal members 210 and connect them. Therefore, the basic configuration of the frame 200 is a rectangular frame material in a plan view. A pair of rails 230 extending parallel to the horizontal members 210 are attached to predetermined locations of the frame 200. As shown in FIG. 3 , the pair of rails 230 are made of metal members having a U-shape (channel shape) with openings on the opposing faces, and these members are connected by at least two connecting members 230A. The pair of rails 230 may be completely separate, or may be rails of a known shape.

[0013] The height change mechanism 300 is composed of hydraulic or electric lifting cylinders 310. As shown in FIG. 3 , main bodies 310A of the lifting cylinders 310 are fixed to the four corners of the frame 200 in a plan view via vertical members 320 whose axes extend vertically. A self-propelled mechanism 400, described in detail below, is attached to the lower end of an actuating section 310B that extends downward from the main body 310A of the lifting cylinder 310 and is telescopic. Therefore, by simultaneously operating the four lifting cylinders 310, the length of the actuating section 310B extending downward from the main body 310A of the lifting cylinder 310 changes, allowing the height of the frame 200 to be freely adjusted relative to the lower end of the self-propelled mechanism 400 attached to the lower end of the actuating section 310B.

[0014] 2, the lifting cylinder 310 located on the left side is shown in a retracted state, and the lifting cylinder 310 located on the right side is shown in an extended state in order to clarify the operation of the height changing mechanism 300. Please note that this is for the purpose of explanation only, and may differ from the actual operating state.

[0015] The self-propelled mechanism 400 includes a wheel support member 410, traveling wheels 420, a reducer 430, an electric motor 440, a drive sprocket 450, a driven sprocket 460, and a chain 470. The wheel support member 410 is a generally box-shaped metal member with an open bottom, and its top is fixed to the lower end of the lifting cylinder 310 of the height changing mechanism 300. Here, as shown in FIG. 3 in particular, the wheel support member 410 is arranged so that a pair of generally rectangular side surfaces extend parallel to the connecting member 220 of the frame 200. Furthermore, the pair of wheel support members 410 arranged in the extension direction of the connecting member 220 of the frame 200 are connected to each other by a connecting rod 480 whose axis extends parallel to the connecting member 220. Therefore, the pair of self-propelled mechanisms 400 attached to the lower ends of the lifting cylinders 310 of the height changing mechanism 300 are prevented from moving relative to each other by the connecting rods 480, thereby improving the rigidity of the frame 200.

[0016] Traveling wheels 420 for traveling on the top surface of the concrete pavement CP are rotatably attached to predetermined locations of the wheel support members 410, specifically between a pair of side surfaces. Therefore, the traveling wheels 420 can roll in a direction perpendicular to the cross members 210 of the frame 200, in other words, in a direction parallel to the connecting members 220 of the frame 200.

[0017] An electric motor 440, which functions as a travel actuator, is attached via a reducer 430 having a predetermined reduction ratio to a portion of the upper surface of the wheel support member 410 where the lower end of the lifting cylinder 310 of the height changing mechanism 300 is not fixed. A drive sprocket 450 is coaxially fixed to the output shaft of the reducer 430. A driven sprocket 460 is coaxially fixed to the running wheel 420. A well-known chain 470 is wound between the drive sprocket 450 and the driven sprocket 460. Therefore, when the electric motor 440 is operated, its rotational torque is increased by the reducer 430 and transmitted to the running wheel 420 via the drive sprocket 450, the chain 470, and the driven sprocket 460.

[0018] As shown in Figures 1 to 3, the cutter unit 500 is configured to be movable along a pair of rails 230 attached to the frame 200. That is, as shown in Figure 3 in particular, a pair of traveling wheels WH are disposed on each of the pair of rails 230, and the traveling wheels WH are capable of rolling in the direction in which the rails 230 extend. A pair of axles AS are attached to predetermined locations on the cutter unit 500, and both ends of the axles AS are connected to the pair of traveling wheels WH, respectively. The specific configuration of the cutter unit 500 will be described later.

[0019] 2, a drive sprocket SP1 and a driven sprocket SP2 are attached to both longitudinal ends of the frame 200, around which a chain CHN for moving the cutter unit 500 is wound. The drive sprocket PS1 is configured to be driven and rotated by an electric motor MTR with a speed reducer, which is attached to a predetermined location on the frame 200. An intermediate portion of the chain CHN wound between the drive sprocket SP1 and the driven sprocket SP2 is fixed to a predetermined location on the cutter unit 500 via a bracket (not shown). Therefore, when the electric motor MTR is operated, the drive sprocket SP1 rotates, which moves the chain CHN wound between the drive sprocket SP1 and the driven sprocket SP2, allowing the cutter unit 500, which is fixed to the chain, to move along the rail 230.

[0020] 1 and 2, the control panel 600 is disposed at one end of the cross member 210 of the frame 200. The control panel 600 has, for example, an electronic control device with a built-in microcomputer, and buttons and switches for operating the joint cutting device 100, and controls the height changing mechanism 300, the self-propelled mechanism 400, the cutter unit 500, and the electric motor MTR for moving the cutter unit 500.

[0021] The work aisle 700 is provided as a passageway for workers who use the joint cutting device 100 to cut joints, and is arranged by a plurality of brackets 710 attached to the side of the frame 200. Note that the work aisle 700 is not a required component.

[0022] As shown in Figures 4 and 5, the cutter unit 500 is composed of a base member 510 having rectangular upper and lower surfaces in a plan view, a disc-shaped cutter 520 that cuts joints in the surface of the concrete pavement CP, an electric motor 530 that is an example of an actuator that rotates the cutter 520, a crawler box 540, and a pair of crawlers 550.

[0023] The cutter 520 is coaxially and replaceably fixed to the lower surface of the base member 510 by a washer WS and a nut NT to the tip end of a drive shaft 520B, which is rotatably supported by a pair of bearings 520A. A driven pulley 520C, to which the rotational driving force of an electric motor 530 is transmitted, is coaxially fixed to the drive shaft 520B, which is located between the pair of bearings 520A. The electric motor 530 is fixed to the upper surface of the base member 510 by a bracket (not shown) with its output shaft parallel to the drive shaft 520B of the cutter 520. A drive pulley 530A, which transmits the rotational driving force of the electric motor 530 to the cutter 520, is coaxially fixed to the output shaft of the electric motor 530.

[0024] A V-belt VB extending through an opening 510A formed at a predetermined location in the base member 510 is wound between the driven pulley 520C of the cutter 520 and the drive pulley 530A of the electric motor 530. Therefore, when the electric motor 530 is operated, its rotational driving force is transmitted to the cutter 520 via the drive pulley 530A, the V-belt VB, the driven pulley 520C, and the drive shaft 520B, thereby driving the cutter 520 to rotate. Here, in this embodiment, an uppercut system is adopted in which the cutter 520 rotates counterclockwise in the configuration shown in FIG. 5.

[0025] As shown in FIG. 6, the crawler box 540 includes a pair of side plates 540A that sandwich the plate surface of the cutter 520 and are arranged beyond its diameter, a front bottom plate 540B that connects the lower ends of the front portions (portions located in the traveling direction of the cutter unit 500) of the pair of side plates 540A together, and a rear bottom plate 540C that connects the lower ends of the rear portions of the pair of side plates 540A together. In the example shown in FIG. 5, the side plate 540A has a rectangular shape, but it is sufficient that at least its lower end is formed in a shape that extends linearly. The front bottom plate 540B is formed in a shape that extends diagonally upward and forward from the front ends of the pair of side plates 540A and then has a portion that extends parallel to the lower ends of the side plates 540A. The rear bottom plate 540C is formed in a shape that extends diagonally upward and rearward from the rear ends of the pair of side plates 540A and then has a portion that extends parallel to the lower ends of the side plates 540A. 6, a slit SL is formed in the center of the plate surface of rear bottom plate 540C, so that the plate surface of cutter 520 can pass through. If there is no risk of interference between rear bottom plate 540C and cutter 520, it is not necessary to form slit SL in rear bottom plate 540C.

[0026] As shown in FIG. 6, each crawler 550 includes a pair of sprockets 550A, a chain 550B wound between the pair of sprockets 550A, and a plurality of crawler plates 550C attached to the chain 550B.

[0027] The pair of sprockets 550A are attached to the side plate 540A of the crawler box 540 via support members 540D that rise vertically from the inner surface of the side plate 540A so as to be rotatable relative to the side plate 540A. The crawler plate 550C is fixed to the outer surface of the chain 550B wound around the pair of sprockets 550A, that is, the outer surface located opposite the sprocket 550A, using known fixing means. The outer surface of the crawler plate 550C, that is, the outer surface located opposite the sprocket 550A, is formed in a flat shape. The pair of crawlers 550 are arranged to form a gap between them that allows the plate surface of the cutter 520 to pass through. The pair of crawlers 550 are attached to the crawler box 540 so as to protrude slightly downward from the lower end of the crawler box 540.

[0028] As shown in FIG. 5, the crawler box 540 containing the pair of crawlers 550 is fixed to a cylinder mounting plate 510B rising from the base member 510 via a front cylinder 560 and a rear cylinder 570. Here, the front cylinder 560 functions as a linear guide that moves the rod portion 560B linearly relative to the cylindrical main body portion 560A. The rear cylinder 570 also functions as a linear guide that moves the rod portion 570B linearly relative to the cylindrical main body portion 570A, similar to the front cylinder 560. Furthermore, the front cylinder 560 positioned in the traveling direction has a rod portion 560B with a longer stroke than the rear cylinder 570 positioned in the opposite direction.

[0029] A main body 560A of a front cylinder 560 is fixed to cylinder mounting plate 510B with the axis of the front cylinder 560 extending obliquely upward as it faces the direction of travel, and a main body 570A of a rear cylinder 570 is fixed to cylinder mounting plate 510B with the axis of the front cylinder 560 extending in the vertical direction. Here, main body 560A of the front cylinder 560 and main body 570A of the rear cylinder 570 may be attached to cylinder mounting plate 510B so as to be swingable. A tip end of rod portion 560B of front cylinder 560 is fixed to a front bracket 580 fixed to the tip end of a front bottom plate 540B of crawler box 540 so as to be swingable around a swing axis perpendicular to the plate surface of cutter 520. In addition, the tip of the rod portion 570B of the rear cylinder 570 is fixed to a rear bracket 590 fixed to the rear end of the rear bottom plate 540C of the crawler box 540 so as to be swingable around a swing axis perpendicular to the plate surface of the cutter 520.

[0030] In this embodiment, a plate-shaped cylinder mounting plate 510B is used to fix the front cylinder 560 and rear cylinder 570 to the base member 510, but it should be noted that these may also be fixed using well-known brackets or the like.

[0031] 5, a plurality of transport wheels 510C are attached to predetermined locations on the base member 510. The transport wheels 510C rotate around a rotation axis perpendicular to the plate surface of the cutter 520 and roll on the surface of the concrete pavement CP to be jointed, as shown in FIG. 5. The transport wheels 510C can be located on the opposite side of the rear cylinder 570 from the cutter 520, and in a location close to the drive shaft 520B of the cutter 520.

[0032] Next, the operation of the jointing device 100 will be described. In the jointer 100, when the frame 200 is raised by the height change mechanism 300, the front cylinder 560 and the rear cylinder 570 are extended due to the weight of the crawler box 540 containing the pair of crawlers 550, as shown in FIG. 7 . At this time, the stroke of the front cylinder 560 is greater than the stroke of the rear cylinder 570, so as is clear from FIG. 7 , the lower end of the crawler box 540 is tilted diagonally downward in the direction of travel. Therefore, by appropriately setting the strokes of the front cylinder 560 and the rear cylinder 570, the lower part of the cutter 520 is housed in the crawler box 540, thereby ensuring the safety of the jointer 100. Furthermore, by positioning the cylinder mounting plate 510B near the plate surface of the cutter 520, the cylinder mounting plate 510B makes it difficult for the outer peripheral edge of the cutter 520, which is exposed to the outside, to be touched, thereby ensuring the safety of the jointer 100.

[0033] After positioning the joint cutting device 100 in a position that covers the concrete pavement CP to be jointed, the electric motor 530 of the cutter unit 500 is operated to rotate the cutter 520, and the height change mechanism 300 gradually lowers the height of the cutter unit 500 relative to the concrete pavement CP. Then, the outer peripheral surfaces of the pair of crawlers 550 protruding downward from the lower end of the crawler box 540, at the portion located on the front cylinder 560 side, come into contact with the concrete pavement CP, and as the cutter unit 500 descends, the inclination angle of the crawler box 540 gradually decreases. As a result, the front cylinder 560 and rear cylinder 570 gradually contract, causing the rotating cutter 520 to protrude from the lower end of the crawler box 540 and cut a joint in the concrete pavement CP located below it. At this time, the crawler 550 rotates due to the change in the inclination angle of the crawler box 540, thereby preventing scratches and other damage from being formed on the surface of the unhardened concrete pavement CP.

[0034] In this state, when the electric motor MTR attached to a predetermined location on the frame 200 is operated to move the cutter unit 500 along the rail 230, a linear joint can be cut into the surface of the concrete pavement CP as the cutter unit 500 moves. At this time, a pair of crawlers 550 travels on the surface of the concrete pavement CP as the cutter unit 500 moves, and since their outer surfaces are formed in a flat shape, scratches and other damage to the surface of the concrete pavement CP can be prevented. Furthermore, because the pair of crawlers 550 are positioned on either side of the cutter 520 and the gap between them is small enough to allow the cutter 520's plate surface to penetrate, the pair of crawlers 550 can press downward on both sides of the concrete pavement CP where the joint will be formed by the cutter 520. Therefore, when cutting a joint into the surface of the concrete pavement CP, both sides of the joint are pressed down by the pair of crawlers 550, ensuring a consistent joint width. This ultimately improves the quality of the joint cut into the surface of the concrete pavement CP.

[0035] Then, once cutting one joint is completed, the height of the cutter unit 500 relative to the concrete pavement CP is raised by the height change mechanism 300. When the cutter unit 500 is raised, the front cylinder 560 and the rear cylinder 570 are extended by the weight of the crawler box 540 containing the pair of crawlers 550, resulting in the state shown in FIG. 7. In this state, as described above, the lower part of the cutter 520 is housed in the crawler box 540, ensuring the safety of the joint cutting device 100. Furthermore, since the pair of crawlers 550 contained in the crawler box 540 rotate as they gradually move away from the surface of the concrete pavement CP, the formation of scratches and other marks on the surface of the concrete pavement CP can be suppressed.

[0036] The electric motor 440 of the self-propelled mechanism 400 can then easily move the entire jointing device 100 to the next jointing location. Then, by sequentially performing the above-mentioned steps, the next joint can be cut. This reduces the movement time of the jointing device 100, thereby reducing the work time required for cutting joints.

[0037] To briefly summarize the above, by using such a joint cutting device 100, the cutter 520 is rotated and driven by the electric motor 530 while the cutter unit 500 is moved along the frame 200, and joints can be cut while the pair of crawlers 550 presses down on the concrete pavement CP on both sides of the cutter 520.

[0038] Those skilled in the art will readily understand that new embodiments can be created by omitting parts of the technical ideas of the various above-described embodiments, combining parts of the ideas appropriately, or replacing parts of the ideas with well-known technology.

[0039] For example, in cutter unit 500, cutter 520 is not limited to being rotationally driven by electric motor 530, but may be rotationally driven by an engine. Also, the object to be jointed is not limited to concrete pavement that constitutes a road, but may be concrete poured in a parking lot, for example. [Explanation of symbols]

[0040] 100...Joint cutting device 200...frames 300...Height change mechanism 400…Self-propelled mechanism 500...Cutter unit 510...Base member 520...Cutter 530...Electric motor (actuator) 550...Crawler 560...Front cylinder (cylinder) 570...Rear cylinder (cylinder) CP...Concrete pavement (concrete)

Claims

1. A base member; a disc-shaped cutter rotatably attached to the base member; an actuator that rotates the cutter; A pair of crawlers are arranged on both sides of the cutter plate surface and come into contact with the surface of the concrete to be jointed; and The outer peripheral surfaces of the pair of crawlers are formed in a flat shape, Cutter unit.

2. The pair of crawlers are arranged at an interval that allows the plate surface of the cutter to penetrate. The cutter unit according to claim 1 .

3. The pair of crawlers are suspended by a pair of cylinders fixed to the base member. The cutter unit according to claim 1 .

4. The pair of cylinders have different strokes, which causes the pair of crawlers to hang down at an angle due to their own weight. The cutter unit according to claim 3 .

5. A joint cutting method using the cutter unit described in claim 1, moving the cutter unit while rotating the cutter with the actuator, and cutting joints while pressing the surface of the concrete on both sides of the cutter with the pair of crawlers.

6. The frame and a cutter unit according to any one of claims 1 to 4, which is arranged movably along the frame; and A joint cutting device having the above structure.

7. Further comprising a self-propelled mechanism for self-propelling the frame. The jointing device according to claim 6.

8. The frame may further include a height adjusting mechanism that can adjust the height of the frame relative to the surface of the concrete. The jointing device according to claim 6.

9. A joint cutting method using the joint cutting device described in claim 6, moving the cutter unit along the frame while rotating the cutter using the actuator of the cutter unit, and cutting joints while pressing the surface of the concrete located on both sides of the cutter with the pair of crawlers.

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