Sweeper for construction site

Abstract

To provide a sweeper suitable for use in construction sites.SOLUTION: A sweeper has a sweeper body 3 that sweeps up and collects trash by moving itself on the floor surface by means of front and rear running wheels. A pair of disc brushes 17 with brush bristles forming a truncated cone is arranged at the front part of the sweeper body in the forward direction such that the brush bristles partially overlap each other on either side of the center line of the sweeper body. The sweeper body is equipped with multiple ultrasonic distance sensors (S5, S6, S7, S8, S13, S14, S15, S16) for detecting obstacles ahead. A specific distance sensor (S6 (S14)) among the multiple distance sensors is arranged such that its sensitivity center line intersects with the sensitivity center lines of at least two other distance sensors (S7, S8 (S15, S16)) in a plan view.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] An embodiment of the present invention relates to a construction site sweeper. [Background technology]

[0002] There are various types of autonomous sweepers available. Most sweepers mainly suck up and collect relatively small and light garbage such as dust on the floor. On the other hand, garbage (construction waste) generated at construction sites includes not only dust, but also relatively large and heavy garbage such as concrete blocks, scraps of wood, metal pieces, metal scraps, glass fragments, and glass scraps.

[0003] Therefore, it has been difficult to collect and store this construction waste by suction.

[0004] In addition, construction waste is so voluminous that the dust box of a conventional sweeper quickly becomes full. Even if a large-capacity dust box is installed, the dust box filled with construction waste becomes very heavy, and it is not easy to transfer the construction waste from the dust box to the garbage collection site. Furthermore, during construction work, the sweeper needs to be transported to a location away from the work site, but it is not easy to transport a heavy and large sweeper by hand.

[0005] Furthermore, a distance sensor is installed at the front of the sweeper to change direction when there is an obstacle such as a wall ahead. In construction sites where there is a lot of dust, ultrasonic sensors are often used as distance sensors. As is well known, ultrasonic sensors have their own directional characteristics depending on the transducer area, etc. For example, the practical range is a sound pressure half-reducing angle of about 10° centered on the sensitivity center line where the sound pressure is the highest. Therefore, in order to eliminate blind spots, it is necessary to distribute a huge number of distance sensors up, down, left, and right, but this is not realistic not only in terms of cost but also due to limitations on the area where the sensors can be installed. In particular, corners of pillars and pipes have entered the blind spots, making it impossible for the sweeper to move.

[0006] There have also been attempts to set areas where sweepers can run and areas where they are prohibited from running by appropriately placing wooden battens on the floor. However, it is difficult to distinguish wooden battens from construction waste, poles, corners of columns, etc., and there are cases where construction waste remains and causes the sweeper to bend, the running area becomes excessively narrow, or the sweeper enters the prohibited area. It is also difficult to distinguish wooden battens from walls, etc., and as a result, corners where construction waste tends to accumulate cannot be cleaned well.

[0007] Thus, there is a demand for a sweeper that can handle such situations at construction sites. Summary of the Invention [Problem to be solved by the invention]

[0008] There is a need for a sweeper suitable for use on construction sites. [Means for solving the problem]

[0009] The sweeper according to this embodiment has a sweeper body that sweeps up dirt while moving on the floor surface by means of front and rear wheels for travel. A pair of disk brushes, whose brush bristles form a truncated cone shape, are arranged at the front of the sweeper body in the traveling direction such that the brush bristles partially overlap each other on either side of the center line of the sweeper body. The sweeper body is equipped with a plurality of ultrasonic distance sensors for detecting obstacles ahead. A specific distance sensor among the plurality of distance sensors is arranged such that its sensitivity center line intersects with the sensitivity center lines of at least two other distance sensors in a plan view. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of a sweeper according to the present embodiment. [Diagram 2] FIG. 2 is a side view of the sweeper of FIG. [Diagram 3] FIG. 3 is a perspective view showing a state in which the dust box is removed from the sweeper body of FIG. [Figure 4] FIG. 4 is a vertical cross-sectional view of the sweeper of FIG. [Diagram 5] FIG. 5 is a schematic vertical cross-sectional view of the sweeper of FIG. [Figure 6] FIG. 6 is a perspective view of the sweeper of FIG. 1 as viewed from below and in the front. [Figure 7] FIG. 7 is a plan view of the sweeper body of FIG. [Figure 8] FIG. 8 is a front view of the sweeper of FIG. [Figure 9] 9 is a left side view and a right side view of the sweeper body of FIG. 1. FIG. [Figure 10] FIG. 10 is a side view showing different detection reference distances of the distance sensor of this embodiment. [Figure 11] FIG. 11 is a plan view showing how the blind spot is significantly reduced by the arrangement of the distance sensors according to this embodiment. [Figure 12] FIG. 12 is a diagram showing a travel area of ​​the sweeper according to this embodiment. [Figure 13] FIG. 13 is a side view showing the distinction between shallow wood and a wall surface by the distance sensor of this embodiment. [Figure 14] FIG. 14 is a diagram showing an example of recognition of a corner between a wall surface and a shallow timber by the sweeper according to this embodiment and the travel trajectory at that time. [Figure 15] FIG. 15 is a diagram showing an example of recognition of a corner between wall surfaces by the sweeper according to this embodiment and the travel trajectory at that time. [Figure 16] FIG. 16 is a diagram showing an example of step recognition by the sweeper according to this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a construction site sweeper according to this embodiment will be described with reference to the drawings. 1 and 2 show the appearance of a sweeper 1 according to this embodiment. FIG. 3 shows a state in which the dust box 5 has been removed from the sweeper body 3. FIG. 4 shows a vertical cross-sectional view of the sweeper 1, and FIG. 5 shows a schematic vertical cross-sectional view of the sweeper 1. The sweeper 1 has a sweeper body 3 that moves on its own over the floor surface of a construction site and scrapes up relatively large and relatively heavy garbage (construction waste) such as concrete chunks, scraps of wood or the like, metal pieces, metal scraps, glass pieces, and glass scraps scattered on the floor surface. A dust box 5 that contains the construction waste scraped up by the sweeper body 3 is detachably fitted into the sweeper body 3.

[0012] The sweeper body 3 has a chassis 15. On the left and right sides of the chassis 15, a moving mechanism 13 is installed with tracks (crawlers) 11 stretched across front and rear drive wheels 7, 9 for self-propulsion, so that the sweeper body 3 is suitable for traveling on rough ground at a construction site. The moving mechanism 13 causes the sweeper body 3 to travel in the direction toward the left side of the page in FIG. 2 .

[0013] A pair of motors 19 are disposed at the front of the sweeper body 3 in the traveling direction, with the center line DS of the rotation shaft (drive shaft) inclined forward with respect to a vertical line perpendicular to the floor surface in a side view. A pair of disk brushes 17, in which flexible synthetic resin brush bristles are planted in a base material 18 in a truncated cone shape, are connected to the rotation shafts of the pair of motors 19. The pair of disk brushes 17 are directly connected to the rotation shaft of the motor 19 so that the center line RR of the truncated cones coincides with the rotation center line DS of the motor 19. For ease of explanation, the rotation center line RR and the rotation center line DS of the motor 19 aligned therewith are collectively referred to as the rotation center line RA. When the sweeper 1 is placed on the floor surface, the front brush bristles of the disk brushes 17 are curved to come into close contact with the floor surface.

[0014] The pair of motors 19 are commonly attached to a single mounting plate 61. The rotation center lines DS of the pair of motors 19 are perpendicular to the plate surface of the mounting plate 61. The interval between the pair of motors 19 is set so that the relative positions of the pair of disc brushes 17 are such that the brush bristles of each of the pair of disc brushes 17 partially overlap with each other across the center line CL of the sweeper body 3 in a plan view.

[0015] The mounting plate 61 is rotatably attached at its rear end to a front overhang 71 of the sweeper body 3 via a hinge 69. As a result, the pair of disk brushes 17, the pair of motors 19, and the weight of the mounting plate 61 cause the mounting plate 61 to rotate about the hinge 69, with the pair of disk brushes 17 remaining in a forward tilted position, and the tips of the bristles are pressed against the floor surface. By shifting the position of the fulcrum for the rotation of the mounting plate 61, the motor 19, and the disk brushes 17, i.e., the pin of the hinge 69, rearward from the rotation center line RA, rather than on it, the rotation radius R from the fulcrum to the front ends of the bristles of the disk brushes 17 can be made longer.

[0016] Fasteners 63, 65 for fastening the mounting plate 61 to the sweeper body 3 are provided on the mounting plate 61 and the sweeper body 3, respectively. The fastener 63 has a movable hook structure attached to the mounting plate 61, and by manually tilting the fastener 63 backward and hooking it onto the fastener 65 having a hook receiving structure protruding forward from the overhanging portion 71 of the sweeper body 3, the mounting plate 61 is prohibited from rotating and fixed in the standard position. By manually tilting the fastener 63 forward and disengaging it from the fastener 65, the rotation prohibition state is released and the mounting plate 61 is permitted to rotate (tilt).

[0017] By controlling a control unit (not shown), the sweeper 1 can selectively operate in a room cleaning mode suitable for cleaning a wide area of ​​a floor surface with relatively few irregularities, and a groove cleaning mode suitable for cleaning linear recesses, i.e., the inside of grooves along the linear direction. In the room cleaning mode, the mounting plate 61 is fixed, whereas in the groove cleaning mode, it is preferable to release the mounting plate 61 from its fixed state and make it rotatable.

[0018] The mounting plate 61 is provided with a limiting structure 73 for limiting its rotation within a predetermined movable range including the reference position. Any structure may be adopted as the limiting structure 73, and for example, it may be composed of an upper abutment plate and a lower abutment plate connected to the rear edge of the mounting plate 61. The upper abutment plate and the lower abutment plate rotate together with the mounting plate 61 and abut against the front edge of the overhanging portion 71 of the sweeper body 3, thereby locking the rotation. The crossing angles of the upper abutment plate and the lower abutment plate relative to the mounting plate 61 are set in advance, and the lower limit (lower limit) of the movable range is determined by the crossing angle of the lower abutment plate 76, and the upper limit (upper limit) of the movable range is determined by the crossing angle of the upper abutment plate 74.

[0019] A motor driver (not shown) rotates a pair of disc brushes 17 in opposite directions in plan view so as to sweep construction waste toward the center line CL from both sides of the sweeper body 3. The left disc brush 17 rotates clockwise, and the right disc brush 17 rotates counterclockwise.

[0020] Inside the sweeper body 3, behind the pair of disc brushes 17, the rear portions of the pair of disc brushes 17 partially overlap, and the sweeping plate 21 is tilted in a position where the rear is higher than the front so as to follow the forward-tilted bristle surfaces of the pair of disc brushes 17. The forward-tilted position of the pair of disc brushes 17 and the sweeping plate 21 realizes that when the pair of disc brushes 17 rotates, it sweeps up the construction waste toward the center line CL, it also sweeps up the construction waste along the sweeping plate 21 (see Figures 4 and 5).

[0021] Inside the sweeper body 3, behind the sweeping plate 21, a cylindrical roller brush 23 is installed with its rotation axis perpendicular to the center line CL. The roller brush 23 is made of flexible synthetic resin brush bristles densely planted radially on the circumferential surface of a cylindrical or columnar support. When the sweeper 1 is placed on the floor surface, the brush bristles that come into contact with the floor surface at the lower part of the roller brush 23 are curved and come into close contact with the floor surface. A motor driver (not shown) drives the motor of the roller brush 23. The roller brush 23 rotates in a direction in which the brush bristles in contact with the floor surface oppose the direction of travel. As a result, dust on the floor surface is captured by the brush bristles of the roller brush 23 and swept up. The construction waste swept up by the pair of disc brushes 17 and swept up along the sweeping plate 21 is sent backward by the brush bristles at the upper part of the roller brush 23.

[0022] A guide plate 25 is installed in the sweeper body 3 behind the roller brush 23 in a backward tilted position. The leading edge of the guide plate 25 is, for example, comb-shaped. Dust collected by the roller brush 23 is scraped off by the leading edge of the guide plate 25.

[0023] The construction waste sent rearward by the roller brush 23 is handed over to the guide plate 25, slides on its top surface, and is guided rearward. The dust collected by the roller brush 23 and scraped off by the tip of the guide plate 25 also slides along the guide plate 25 and is guided rearward. The construction waste and dust guided rearward by the guide plate 25 are received in the dust box 5, drop, and are stored. The construction waste is swept up along the sweeping plate 21 (see Figure 4). As the pair of disc brushes 17 sweeps the construction waste upward along the sweeping plate 21, the dust box 5 can be made taller, and its capacity can be increased.

[0024] The dust box 5 has a rectangular box shape with the top of the front panel open as an inlet 27 for construction waste and dust. The front-to-back length of the dust box 5 is about half the length of the sweeper body 3. The left-to-right width of the dust box 5 is almost the same as the width of the sweeper body 3. The height of the dust box 5 is configured to be equal to or higher than that of the sweeper body 3. The sweeper body 3 is provided with a recess (fitting portion) 60 (see FIG. 3(b)) above the moving mechanism 13 for fitting the dust box 5 detachably. When fitted into the fitting portion 60 of the sweeper body 3, the upper surface and the upper rear end surface of the dust box 5 are exposed, and a handle 33 described later is attached to the exposed upper surface of the dust box 5, and a base 43 described later is attached to the upper rear end surface. The dust box 5 is fitted into the fitting portion 29 of the sweeper body 3 and fixed by a fixing device 31. When the fasteners 31 are released, the dust box 5 can be removed and separated from the sweeper body 3.

[0025] By concentrating the disc brushes 17 and roller brushes 23 at the front of the sweeper body 3 and positioning the dust box 5 and moving mechanism 13 behind them, it is possible to configure the dust box 5 to be approximately half the length of the sweeper body 3, thereby making it possible to increase the capacity of the dust box 5 and also to prevent construction waste from getting in between the bottom of the sweeper body 3 and the floor, making it impossible to move.

[0026] Furthermore, by placing the dust box 5 above the moving mechanism 13, the load-bearing capacity is improved and an increase in the amount of construction waste stored can be tolerated; furthermore, no matter how the construction waste falls into the dust box 5, the center of gravity of the dust box 5 and the entire construction waste is located between the front and rear wheels 7, 9 of the moving mechanism 13, so that fluctuations in the posture of the sweeper 1 can be suppressed.

[0027] A handle 33 is attached to the dust box 5 on its upper surface. The handle 33 is divided into two parts, a handle portion 35 fixed to the dust box 5 and a handle portion 37 connected to the handle portion 35 by a hinge 39 so that the handle 33 can be folded. The total length of the folded handle 33 is shorter than the total length of the sweeper 1 so that the handle 33 fits within the front-rear range of the sweeper 1. Thus, when the handle 33 is folded, the handle 33 does not interfere with the movement of the sweeper 1. When the handle 33 is unfolded, the handle 33 is extended. The extended state of the handle 33 is locked by a hook-structured fastener 41 and a hook receiver 42. An operator can hold the handle 33 and transport the dust box 5 separated from the sweeper body 3 by itself, and can also transport the sweeper body 3 together with the dust box 5, that is, the entire sweeper 1, with the dust box 5 attached to the sweeper body 3.

[0028] A pedestal 43 is provided at the rear end of the dust box 5. The pedestal 43 has a frustum-shaped pedestal body 45. Wheels 46 are attached to one side of the pedestal body 45. Four legs 47 made of an elastic material such as rubber are attached to the bottom of the pedestal body 45. The pedestal body 45 is rotatably attached to the upper surface of the rear part of the dust box 5 via hinges 49. The pedestal body 45 can be flipped up to the top of the dust box 5 and removed. A hook-shaped fastener 51 is attached to the upper surface of the rear part of the dust box 5, and the pedestal 43 can be fastened to the upper surface of the rear part of the dust box 5 by hooking it onto a hook receiving part (not shown) at the bottom of the pedestal body 45. This prevents the pedestal 43 from interfering with the movement of the sweeper 1.

[0029] When the fasteners 51 are removed, the base 43 can be rotated toward the rear end face of the dust box 5 and lowered. A fastener 48 is provided on the rear end face of the dust box 5 to fasten the base 43 lowered to the rear end face of the dust box 5. The worker releases the fixing device 31 to remove the dust box 5 from the sweeper body 3, rotates the base 43 toward the rear end of the dust box 5, and fastens it with the fastener 48. Then, the worker grasps the handle 33 and gradually lifts the base 43 until the wheels 46 of the base 43 touch the ground. The legs 47 and the wheels 46 are configured and arranged so that the wheels 46 touch the ground before the legs 47 during this lifting operation.

[0030] By pulling the handle 33 with the wheels 46 on the ground, the wheels 46 roll and the dust box 5 loaded with construction waste and the like can be easily transported by itself. By lifting it further upright, the wheels 46 leave the floor and the legs 47 touch the ground, allowing the dust box 5 removed from the sweeper body 3 to be placed upright on the floor by itself.

[0031] Furthermore, with the dust box 5 attached to the sweeper body 3, the sweeper 1 can be easily transported by grasping the handle 33, lifting it, and moving it with the wheels 46 of the base 43 on the ground, as the wheels 46 roll. By further lifting it upright, removing the wheels 46 from the floor and allowing the legs 47 to touch the ground, the entire sweeper 1 can be placed upright on the floor.

[0032] As shown in Figures 6, 7, 8, 9(a) and 9(b), the sweeper body 3 is equipped with a plurality of ultrasonic distance sensors S1-S18 for detecting obstacles in front, on the right and on the left. Although the distance sensors S1-S18 are illustrated as being equipped with a separate transmitter and receiver, they may be equipped with a single transmitter and receiver. In the following description, the term "sensitivity centerline" of each of the distance sensors S1-S18 is used, and in the case where the transmitter and receiver are provided separately, the sensitivity centerline is defined as the centerline between the centerline that passes through the center point of the vibration surface of the transmitter and is perpendicular to the vibration surface, and the centerline of the receiver, and in the case of a transmitter and receiver, it is defined as the centerline of the vibration surface.

[0033] Distance sensors S1-S8 are arranged to detect obstacles on the right side of sweeper body 3. Distance sensors S9-S16 are arranged to detect obstacles on the left side of sweeper body 3. Distance sensors S17 and S18 are arranged to detect obstacles directly ahead of sweeper body 3. These will be explained in detail below.

[0034] As shown in FIG. 7, the distance sensor S1 is disposed at the rear of the sweeper body 3 so that its sensitivity center line (1) is perpendicular to the center line CL of the sweeper body 3 in a plan view, and is inclined slightly downward with respect to the horizontal reference line HL in a front view and a side view as shown in FIG. 8 and FIG. 9(a). The distance sensor S2 is disposed at the front of the sweeper body 3 so that its sensitivity center line (2) is perpendicular to the center line CL of the sweeper body 3 in a plan view and parallel to the horizontal reference line HL in a front view. The distance sensor S3 is disposed at the center of the sweeper body 3 so that its sensitivity center line (3) is inclined slightly forward with respect to the center line CL of the sweeper body 3 in a plan view and is almost downward in a front view and a side view. The distance sensor S4 is disposed at the center of the sweeper body 3 so that its sensitivity center line (4) is inclined slightly forward with respect to the center line CL of the sweeper body 3 in a plan view and is inclined slightly downward in a front view and a side view.

[0035] The distance sensor S8 is disposed at the rear of the sweeper body 3 so that its sensitivity center line (8) is perpendicular to the center line CL of the sweeper body 3 in a plan view and is slightly inclined downward with respect to the horizontal reference line HL in a front view and a side view as shown in Fig. 8 and Fig. 9(b). The distance sensor S10 is disposed at the front of the sweeper body 3 so that its sensitivity center line (10) is perpendicular to the center line CL of the sweeper body 3 in a plan view and is parallel to the horizontal reference line HL in a front view. The distance sensor S11 is disposed at the center of the sweeper body 3 so that its sensitivity center line (11) is slightly inclined forward with respect to the center line CL of the sweeper body 3 in a plan view and is almost downward in a front view and a side view. The distance sensor S11 is disposed at the center of the sweeper body 3 so that its sensitivity center line (11) is slightly inclined forward with respect to the center line CL of the sweeper body 3 in a plan view and is slightly inclined downward in a front view and a side view.

[0036] The distance sensors S5-S8 (first distance sensors) are provided to detect obstacles on the front right side, and the distance sensors S13-S16 (second distance sensors) are provided to detect obstacles on the front left side.

[0037] The distance sensors S5-S8 are arranged so that their sensitivity centerlines (5)-(8) are inclined slightly to the left with respect to the center line CL of the sweeper body 3 in a plan view. The distance sensor S5 is installed on the right side of the front end of the sweeper body 3 so that its sensitivity centerline (5) is inclined to the right at an angle of 40° with respect to the center line CL. The distance sensors S7 and S8 are installed at a certain distance near the center of the front end of the sweeper body 3 so that their sensitivity centerlines (7) and (8) are inclined to the right at an angle of 20° with respect to the center line CL and are parallel to each other.

[0038] The distance sensor S6 (a specific distance sensor) is installed on the left side opposite the distance sensor S5 at the front end of the sweeper body 3 so that its sensitivity center line (6) is inclined to the right at an angle of 52.5° with respect to the center line CL and intersects with the sensitivity center lines (7) and (8) of at least two other distance sensors S7 and S8, and preferably with the sensitivity center lines (5), (7), and (8) of the other three distance sensors S5, S7, and S8 and the sensitivity center lines (14)-(16) of the distance sensors S14-S16 that detect obstacles on the front left side.

[0039] The same is true for the distance sensors S13-S16 for the front left side. The sensitivity center lines (13)-(16) of the distance sensors S13-S16 are inclined slightly to the left with respect to the center line CL of the sweeper body 3 in a plan view. The distance sensor S13 is installed on the left side of the front end of the sweeper body 3 so that its sensitivity center line (13) is inclined to the left at an angle of 40° with respect to the center line CL. The distance sensors S15 and S16 are installed at a certain interval near the center of the front end of the sweeper body 3 so that their sensitivity center lines (15) and (16) are inclined to the left at an angle of 20° with respect to the center line CL and are parallel to each other.

[0040] The distance sensor S14 (a specific distance sensor) is installed on the right side of the front end of the sweeper body 3 so that its sensitivity center line (14) is inclined to the left at an angle of 52.5° with respect to the center line CL and intersects with the sensitivity center lines (15), (16) of at least two other distance sensors S15, S16, and preferably with the sensitivity center lines (13), (15), (16) of the other three distance sensors S13, S15, S16 and the sensitivity center lines (6)-(8) of the distance sensors S6-S8 that detect obstacles on the front right side.

[0041] Furthermore, in a planar view, distance sensors S6, S8, S14, S16, S17, and S18 are positioned so that their sensitivity center lines (6), (8), (14), (16), (17), and (18) intersect at a single point on the center line CL of the sweeper body 3.

[0042] As shown in FIG. 8, the sensitivity center lines (5)-(8) of the distance sensors S5-S8 are slightly inclined to the right with respect to the horizontal reference line HL in a front view. The distance sensor S6 (a specific distance sensor) is installed so that its sensitivity center line (6) intersects with the sensitivity center lines (7) and (8) of at least two other distance sensors S7 and S8. The sensitivity center lines (13)-(16) of the distance sensors S13-S16 are slightly inclined to the left with respect to the horizontal reference line HL in a front view. The distance sensor S14 (a specific distance sensor) is installed so that its sensitivity center line (14) intersects with the sensitivity center lines (15) and (16) of at least two other distance sensors S15 and S16. Furthermore, in a plan view, the distance sensors S6, S8, S14, S16, and S17 are arranged so that their sensitivity center lines (6), (8), (14), (16), and (17) intersect at one point.

[0043] As shown in FIG. 9(a) and FIG. 10(a), in a side view, the distance sensors S5 and S6 are attached at a forward inclination angle such that their sensitivity center lines (5) and (6) reach the floor surface at a distance (detection reference distance) AD2 from the front end of the sweeper body 3. The distance sensors S5 and S6 detect obstacles approaching within the distance AD2 from the front end of the sweeper body 3. The distance sensor S7 is attached at a forward inclination angle such that its sensitivity center line (7) reaches the floor surface at a distance AD1 shorter than the distance AD2 from the front end of the sweeper body 3. The distance sensor S7 detects obstacles approaching within the distance AD1 from the front end of the sweeper body 3. The distance sensor S8 is attached at a forward inclination angle such that its sensitivity center line (8) reaches the floor surface at a distance AD3 longer than the distance AD2 from the front end of the sweeper body 3. The distance sensor S8 detects obstacles approaching within the distance AD3 from the front end of the sweeper body 3. The distance sensor S17 is mounted at a forward inclination angle such that its sensitivity center line (17) reaches the floor surface at a distance AD4 from the front end of the sweeper body 3, which is longer than the distance AD3, and detects an obstacle approaching within the distance AD4.

[0044] As shown in Figures 9(b) and 10(b), in a side view, the distance sensors S13 and S14 are mounted at a forward inclination angle such that their sensitivity center lines (13) and (14) reach the floor surface at a distance AD2 from the front end of the sweeper body 3, and detect obstacles approaching within the distance AD2 from the front end of the sweeper body 3. The distance sensor S15 is mounted at a forward inclination angle such that its sensitivity center line (15) reaches the floor surface at a distance AD1 shorter than the distance AD2 from the front end of the sweeper body 3, and detects obstacles approaching within the distance AD1. The distance sensor S16 is mounted at a forward inclination angle such that its sensitivity center line (16) reaches the floor surface at a distance AD3 longer than the distance AD2 from the front end of the sweeper body 3, and detects obstacles approaching within the distance AD3.

[0045] As shown in FIG. 11, among the forward distance sensors S5-S8, S13-S16, S17, and S18, the sensitivity center line (6) of the distance sensor S6 (a specific distance sensor) intersects with the sensitivity center lines (7), (8) of at least two of the distance sensors S7 and S8, and similarly, the sensitivity center line (14) of the distance sensor S14 (a specific distance sensor) intersects with the sensitivity center lines (15), (16) of at least two of the distance sensors S15 and S16. Therefore, construction waste and obstacles such as poles and pillars can be detected over a wide range (wide angle) in the forward direction, and even if these obstacles are between the sensitivity center lines (5), (7), and (8) or between the sensitivity center lines (13), (15), and (16), they can still be detected, and the blind spot where detection is impossible can be significantly reduced.

[0046] In addition, by having the sensitivity center lines (6), (8), (14), and (16) of more distance sensors S6, S8, S14, and S16 intersect at intersection C1 on the sensitivity center line (17) of the distance sensor S17 located directly in front, the blind spot near intersection C1 can be almost completely eliminated, thereby effectively preventing the sweeper 1 from colliding head-on with an obstacle.

[0047] Furthermore, at intersections C2, C3 on either side of intersection C1 directly in front of the sweeper 1 and slightly further away than intersection C1, the sensitivity center lines (6), (7) of the distance sensors S6, S7 are intersected, and the sensitivity center lines (14), (15) of the distance sensors S14, S15 are intersected. This virtually eliminates the blind spots of intersections C1, C2, C3, effectively preventing the sweeper 1 from coming into contact with an obstacle when it turns on the spot.

[0048] As described above, in this embodiment, it is possible to selectively operate in a room cleaning mode suitable for cleaning a wide area of ​​a floor surface with relatively few irregularities, and a groove cleaning mode suitable for cleaning the inside of grooves along their linear direction, and the travel area of ​​the sweeper 1 in each of these modes can be set by appropriately arranging multiple pieces of shallow timber (see Figure 12).

[0049] To achieve this, it is necessary to distinguish between shallow timber and walls and to recognize the distance to each of the shallow timber and the wall. In this embodiment, as shown in FIG. 13, of the forward distance sensors S5-S8, S13-S16, S17, and S18, distance sensor S18 is positioned so that its sensitivity center line (18) is horizontal, and the other distance sensors S5-S8 (S13-S16) are positioned so that the forward inclination angles of their sensitivity center lines (5)-(8) ((13)-(16)) are different. This makes it possible to clearly distinguish between shallow timber and walls and to easily recognize the distance to each of the shallow timber and the wall.

[0050] Typically, a circuit configuration is adopted in which the output value of the distance sensor is compared with a reference value corresponding to each detection distance by a comparator, and the state of the signal processing is changed when the detection distance becomes less than the detection reference distance. It is also assumed that the direction is changed when the vehicle approaches shallow wood to a distance AD3, and when the vehicle approaches a wall to a distance AD1. In this case, when the distance sensors S8, S16, and S17 among the front distance sensors S5-S8, S13-S16, S17, and S18 indicate a state change and the other distance sensors do not indicate a state change, the control unit (not shown) can recognize that the obstacle is shallow wood and has approached to a distance AD3. On the other hand, when all of the front distance sensors S5-S8, S13-S16, S17, and S18 indicate a state change, the control unit can recognize that the obstacle is a wall and has approached to a distance AD1.

[0051] A specific operation example will be described. For example, as shown in FIG. 14(a), the sweeper 1 moves along the wall while approaching the wall to a predetermined distance by the distance sensor S10. Then, as shown in FIG. 14(b), when the wall is detected by the distance sensor S10 and the distance sensor S17 detects the presence of an obstacle at a predetermined distance ahead, and the distance sensor S18 does not detect the obstacle, the combination of the detection results makes it possible to recognize that the obstacle ahead is a shallow timber and further a corner between the wall and the shallow timber. As shown in FIG. 14(c), according to the recognition result that the obstacle ahead is a shallow timber and a corner between the wall and the shallow timber, the sweeper turns in a direction away from the wall while maintaining a predetermined distance from the shallow timber, and can avoid entering the no-entry area.

[0052] Also, as shown in FIG. 15(a), the sweeper 1 moves along the wall surface while approaching the wall surface to a predetermined distance, for example, by the distance sensor S10. Then, when the wall surface is detected by the distance sensor S10, and the distance sensors S17 and S18 both detect the presence of an obstacle at a predetermined distance forward, as shown in FIG. 15(b), it is possible to recognize that the obstacle in front is the wall surface and its corner by combining the detection results. When it is recognized that it is a corner of the wall surface, as shown in FIG. 15(c), the sweeper 1 retreats a predetermined distance, and as shown in FIG. 15(d), the disk brush 17 approaches the wall surface in front until the tip of the brush reaches the wall surface. The retreat and approach are repeated once or a predetermined number of times. After that, as shown in FIG. 15(e), the sweeper 1 turns 90° and moves along the wall surface. This makes it possible to clean the corner of the wall surface appropriately.

[0053] As shown in Fig. 16, there may be a recess in the floor called a step slab for placing a unit bath or a step at the entrance, and the presence of such a step can be detected when the detection distance of, for example, distance sensors S3 and S11 whose sensitivity centers are tilted forward from the left and right sides exceeds a predetermined distance from each to the floor. The sweeper 1 recognizes the step as a no-entry area and can stop and rotate as appropriate to avoid falling.

[0054] As described above, according to this embodiment, it is possible to realize a sweeper equipped with functions suitable for construction sites, such as increasing the capacity of the dust box, separating the dust box from the sweeper body and transporting it alone and reducing the transport load, reducing the transport load of the entire sweeper, suppressing the possibility of an incident where the sweeper cannot move, easily placing the dust box alone and minimizing the occupied area, and easily placing the entire sweeper and minimizing the occupied area, without complicating the structure. Furthermore, by providing the disc brush with a tiltable motion, it is possible to sweep and collect construction waste from the boundary between the floor surface and the convex part and the bottom of the groove by following the unevenness of the floor grain.

[0055] Furthermore, in this embodiment, it is possible to achieve various operational effects, such as reducing the blind spots, without densely arranging a huge number of distance sensors.

[0056] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0057] 1...Sweeper, 3...Sweeper body, 5...Dust box, 7, 9...Driving wheels, 11...Crawler tracks, 13...Moving mechanism, 15...Chassis, 19...Motor, 17...Disc brush, 21...Sweeping plate, 23...Roller brush, 25...Guide plate, S1-S18...Distance sensor.

Claims

1. A sweeper having a sweeper body that sweeps up trash while moving on a floor surface by front and rear wheels for running, A pair of disk brushes having brush bristles in a truncated cone shape are arranged at the front of the sweeper body in the moving direction so that the brush bristles partially overlap each other across the center line of the sweeper body, The sweeper body is equipped with a plurality of ultrasonic distance sensors for detecting obstacles ahead, A sweeper, wherein a specific distance sensor among the plurality of distance sensors is disposed such that a sensitivity center line thereof intersects with sensitivity center lines of at least two other distance sensors in a plan view.

2. The sweeper of claim 1 further comprising a dust box for containing the collected debris.

3. The sweeper according to claim 1 , wherein the at least two other distance sensors have centerlines of sensitivity that do not intersect with each other in a plan view and a front view.

4. The sweeper according to claim 3 , wherein the at least two other distance sensors have centerlines of sensitivity parallel to each other in a plan view.

5. The sweeper according to claim 1 , wherein the plurality of distance sensors are arranged so that a center line of sensitivity is inclined forward in a side view.

6. The sweeper according to claim 5 , wherein the plurality of distance sensors are different from one another in terms of positions at which their sensitivity center lines reach the traveling surface of the sweeper body in a side view.

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