Sweeper for construction sites

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] Embodiments of the present invention relate to a sweeper for construction sites.

Background Art

[0002] Conventionally, there are various self-driving sweepers. Many sweepers mainly suck and collect relatively fine and light dust on the floor. On the other hand, construction waste generated at construction sites includes not only dust but also relatively large and heavy objects such as concrete blocks, scraps of wood, metal pieces, metal scraps, glass pieces, and glass scraps.

[0003] Therefore, it has been difficult to accumulate and collect these construction wastes by suction.

[0004] In addition, the amount of construction waste is large, and the dust box of a conventional sweeper will quickly become full. Even if it has a large-capacity dust box, the dust box full of construction waste will become very heavy, and it is not easy to transfer the construction waste from the dust box to the garbage collection site. And during construction work, it is necessary to move the sweeper to a place away from the work site, but it is not easy to manually move a heavy and large sweeper.

[0005] Furthermore, a distance sensor is installed in the front part of the sweeper to change direction when there are obstacles such as walls in the front. As the distance sensor, in many cases, an ultrasonic sensor is adopted at a construction site with a lot of dust. As is well known, the ultrasonic sensor has its own directivity characteristics according to the vibrator area and the like. For example, the range of the sound pressure half-angle of about 10° centered on the sensitivity center line with the highest sound pressure is the practical range. Therefore, in order to eliminate dead angles, it is necessary to disperse and arrange a huge number of distance sensors vertically, horizontally, and diagonally. However, not only is it costly, but there are also limitations in the installation area of the sensors, which is not practical. In particular, the corners of columns, pipes, etc. may fall into dead angles, causing the sweeper to become unable to travel.

[0006] Attempts have also been made to define areas where the sweeper can operate and areas where it is prohibited by placing wooden battens on the floor surface. However, it is difficult to distinguish the wooden battens from construction waste, poles, corners of columns, etc., which can lead to construction waste remaining in the area, the operating area becoming excessively narrow, or the sweeper entering prohibited areas. Furthermore, it is difficult to distinguish the wooden battens from walls, etc., which can result in corners where construction waste tends to accumulate not being cleaned properly.

[0007] Thus, there is a demand for sweepers that can handle these conditions at construction sites. [Overview of the project] [Problems that the invention aims to solve]

[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 moves on the floor surface using front and rear wheels for travel, sweeping up debris. A pair of disc brushes, each with bristles forming a truncated cone shape, are arranged on the front of the sweeper body in the direction of travel, with the bristles partially overlapping each other on either side of the center line of the sweeper body. The sweeper body is equipped with multiple ultrasonic distance sensors for detecting obstacles in front. Of the multiple distance sensors, a specific distance sensor is in a plan view and front view In this configuration, the sensitivity centerline is positioned to intersect with the sensitivity centerlines of at least two other distance sensors. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view of the sweeper according to this embodiment. [Figure 2] Figure 2 is a side view of the sweeper shown in Figure 1. [Figure 3] Figure 3 is a perspective view showing the sweeper body from Figure 1 with the dust box removed. [Figure 4] Figure 4 is a longitudinal cross-sectional view of the sweeper shown in Figure 1. [Figure 5] Figure 5 is a schematic longitudinal section of the sweeper shown in Figure 1. [Figure 6] Figure 6 is a perspective view of the sweeper shown in Figure 1, viewed from the front and below. [Figure 7] Figure 7 is a plan view of the sweeper body shown in Figure 1. [Figure 8] Figure 8 is a front view of the sweeper shown in Figure 1. [Figure 9] Figure 9 shows the left and right side views of the sweeper body shown in Figure 1. [Figure 10] Figure 10 is a side view showing the difference in detection reference distance of the distance sensor in this embodiment. [Figure 11] Figure 11 is a plan view showing how the arrangement of distance sensors in this embodiment significantly reduces blind spots. [Figure 12] Figure 12 shows the travel area of ​​the sweeper according to this embodiment. [Figure 13] Figure 13 is a side view showing the distinction between shallow wood and the wall surface using the distance sensor in this embodiment. [Figure 14] Figure 14 shows an example of the sweeper's recognition of a corner between a wall surface and a shallow piece of wood according to this embodiment, and the sweeper's trajectory at that time. [Figure 15] Figure 15 shows an example of the sweeper's recognition of a corner between two walls according to this embodiment, and the trajectory it travels at that time. [Figure 16] Figure 16 shows an example of step recognition by a sweeper according to this embodiment. [Modes for carrying out the invention]

[0011] The sweeper for construction sites according to this embodiment will be described below with reference to the drawings. Figures 1 and 2 show the external appearance of the sweeper 1 according to this embodiment. Figure 3 shows the sweeper body 3 with the dust box 5 removed. Figure 4 shows a longitudinal cross-sectional view of the sweeper 1, and Figure 5 shows a schematic longitudinal cross-sectional view of the sweeper 1. The sweeper 1 has a sweeper body 3 that moves on the floor surface of a construction site and sweeps up relatively large and relatively heavy debris (construction waste) scattered on the floor surface, such as concrete blocks, scraps of wood, metal fragments, metal scraps, glass fragments, and glass shards. A dust box 5 for containing the construction waste swept 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 are equipped with a movement mechanism 13, which consists of front and rear drive wheels 7 and 9 with tracks (crawlers) 11 attached to them, suitable for traveling on uneven terrain at construction sites. The sweeper body 3 travels using the movement mechanism 13, with the direction of travel being towards the left side of the page in Figure 2.

[0013] A pair of motors 19 are positioned at the front of the sweeper body 3 in the direction of travel, with the centerline DS of their rotation axes (drive axes) tilted forward relative to a vertical line perpendicular to the floor surface in a side view. A pair of disc brushes 17, each with flexible synthetic resin bristles planted in a frustoconical shape on a base material 18, are connected to the rotation axes of the pair of motors 19. The pair of disc brushes 17 are directly connected to the rotation axis of the motors 19 such that the centerlines RR of their frustocones coincide with the rotation centerline DS of the motors 19. For the sake of explanation, the rotation centerline RR and the rotation centerline DS of the motors 19 that align with it will be collectively referred to as the rotation centerline RA. When the sweeper 1 is brought into contact with the floor surface, the front bristles of the disc brushes 17 curve and 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 orthogonal to the plate surface of the mounting plate 61. The distance between the pair of motors 19 is set such that the relative positions of the pair of disk brushes 17 partially overlap each other's brush filaments with the center line CL of the sweeper body 3 interposed therebetween in a plan view.

[0015] The mounting plate 61 is pivotally attached to the overhanging portion 71 in front of the sweeper body 3 at its rear end via a hinge 69. Thereby, due to the self-weight of the pair of disk brushes 17, the pair of motors 19, and further the mounting plate 61, the mounting plate 61 rotates about the hinge 69 as a fulcrum and remains in a forward-tilted posture, and their bristles are pressed against the floor surface. By shifting the position of the fulcrum of the rotation of the mounting plate 61, the motors 19, and the disk brushes 17, that is, the position of the pin of the hinge 69, behind rather than on the rotation center line RA, the rotation radius R from the fulcrum to the front end of the bristles of the disk brush 17 can be increased.

[0016] Fasteners 63, 65 for fixing 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. By manually tilting the fastener 63 backward and hooking it on the fastener 65 having a hook receiving structure protruding forward from the overhanging portion 71 of the sweeper body 3, the rotation of the mounting plate 61 is prohibited and it is fixed in the reference posture. By manually tilting the fastener 63 forward and detaching it from the fastener 65, the rotation prohibition state is released and the rotation (tilting) of the mounting plate 61 is permitted.

[0017] Note that the sweeper 1 can selectively operate in a room cleaning mode suitable for cleaning a floor surface with relatively few irregularities over a wide range under the control of a control unit not shown in the drawings, and a groove cleaning mode suitable for cleaning the inside of a stripe recess, that is, a groove, along the stripe direction. In the room cleaning mode, it is preferable to fix the mounting plate 61, while in the groove cleaning mode, it is preferable to release the fixing of the mounting plate 61 and pivotally provide the mounting plate 61.

[0018] The mounting plate 61 is provided with a limiting structure 73 to restrict its rotation to a predetermined range of motion, including a reference position. Any structure can be used as the limiting structure 73, but for example, it consists of an upper contact plate and a lower contact plate connected to the rear edge of the mounting plate 61. The upper contact plate and the lower contact plate rotate together with the mounting plate 61 and their rotation is locked when they come into contact with the front edge of the overhang 71 of the sweeper body 3. The intersection angles of the upper contact plate and the lower contact plate with respect to the mounting plate 61 are set in advance, and the lower limit of the range of motion (lower limit) is determined by the intersection angle of the lower contact plate 76, and the upper limit of the range of motion (upper limit) is determined by the intersection angle of the upper contact plate 74.

[0019] A motor driver (not shown) rotates a pair of disc brushes 17 in opposite directions in a plan view, so as to sweep construction waste from both sides of the sweeper body 3 toward the center line CL. 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 so that its rear is higher than its front, following the forward-sloping bristle surfaces of the pair of disc brushes 17 (forward tilt). The forward tilt of the pair of disc brushes 17 and the sweeping plate 21 allows the rotation of the pair of disc brushes 17 to sweep construction waste towards the center line CL, and also to sweep the construction waste up 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 axis of rotation perpendicular to the center line CL. The roller brush 23 consists of a cylindrical or cylindrical support with flexible synthetic resin bristles densely packed and arranged radially in cross-section on its circumferential surface. When the sweeper 1 is brought to the ground, the bristles of the roller brush 23 that contact the ground are curved and in close contact with the ground. A motor driver (not shown) drives the motor of the roller brush 23. The roller brush 23 rotates in a direction opposite to the direction of travel for the bristles that are in contact with the ground. As a result, dust on the ground is collected and swept up by the bristles of the roller brush 23. Construction waste swept up by the pair of disc brushes 17 and along the sweeping plate 21 is sent backward by the bristles at the top of the roller brush 23.

[0022] Inside the sweeper body 3, a guide plate 25 is installed behind the roller brush 23 in a backward-tilting position, sloping downwards toward the rear. The leading edge of the guide plate 25 is, for example, comb-shaped. The dust collected by the roller brush 23 is scraped off by the leading edge of the guide plate 25.

[0023] Construction waste pushed backward by the roller brush 23 is transferred to the guide plate 25, where it slides along its upper surface and is guided backward. Dust collected by the roller brush 23 and scraped off at the tip of the guide plate 25 also slides along the guide plate 25 and is guided backward. Construction waste and dust guided backward by the guide plate 25 are received, fall into the dust box 5, and are contained. Construction waste is swept up along the sweeping plate 21 (see Figure 4). Since the construction waste is swept upward along the sweeping plate 21 by the pair of disc brushes 17, 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 an opening at the top of the front panel serving as an inlet 27 for receiving construction waste and dust. The length of the dust box 5 is approximately half the length of the sweeper body 3. The width of the dust box 5 is approximately the same as the width of the sweeper body 3. The height of the dust box 5 is the same as or greater than that of the sweeper body 3. The sweeper body 3 has a recess (fitting part) 60 (see Figure 3(b)) above the moving mechanism 13 for detachably fitting the dust box 5. When the dust box 5 is fitted into the fitting part 60 of the sweeper body 3, the top surface and the upper rear end surface of the dust box 5 are exposed. The handle 33, described later, is attached to the exposed top surface of the dust box 5, and the base 43, described later, is attached to the upper rear end surface. The dust box 5 is fitted into the fitting part 29 of the sweeper body 3 and secured by a fixing device 31. When the fixing device 31 is released, the dust box 5 can be removed from the sweeper body 3 and separated.

[0025] By arranging the disc brush 17 and roller brush 23 together at the front of the sweeper body 3 and positioning the dust box 5 and moving mechanism 13 behind them, it becomes possible to configure the dust box 5 to be approximately half the length of the sweeper body 3, thereby increasing the capacity of the dust box 5. At the same time, it becomes possible to prevent construction waste from entering between the bottom of the sweeper body 3 and the floor surface, which could render the sweeper immobile.

[0026] Furthermore, by installing the dustbin 5 above the mobile mechanism 13, the load-bearing capacity is improved, allowing for an increase in the amount of construction waste to be stored. Moreover, no matter how the construction waste falls into the dustbin 5, the overall center of gravity of the dustbin 5 and the construction waste is located between the front and rear wheels 7 and 9 of the mobile mechanism 13, thus suppressing changes in the posture of the sweeper 1.

[0027] A handle 33 is attached to the upper surface of the dust box 5. 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 it can be folded. The total length of the folded handle 33 is shorter than the total length of the sweeper 1 so that it fits within the front-to-back range of the sweeper 1. As a result, when the handle 33 is folded, the handle 33 does not obstruct the movement of the sweeper 1. The handle 33 extends when unfolded. The extended state of the handle 33 is secured by a hook-structure fastener 41 and a hook receiver 42. A worker can grasp the handle 33 and carry the dust box 5 separated from the sweeper body 3 by itself, or they can carry the sweeper body 3 together with the dust box 5 attached to the sweeper body 3, that is, the entire sweeper 1.

[0028] A base 43 is provided at the rear end of the dustbin 5. The base 43 has a truncated pyramidal base body 45. A wheel 46 is attached to one side of the base body 45. Four legs 47 made of an elastic material such as rubber are attached to the bottom of the base body 45. The base body 45 is rotatably attached to the upper rear surface of the dustbin 5 via a hinge 49. The base body 45 can be flipped up onto the top of the dustbin 5 and retracted. A fastener 51 with a hook structure is attached to the upper rear surface of the dustbin 5, and the base 43 can be secured to the upper rear surface of the dustbin 5 by hooking it onto a hook receiving part (not shown) at the bottom of the base body 45. As a result, the base 43 does not obstruct the movement of the sweeper 1.

[0029] When the fastener 51 is released, the base 43 can be rotated towards the rear end face of the dust box 5 and lowered. The rear end face of the dust box 5 is provided with a fastener 48 for securing the base 43 when it is lowered towards 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 towards the rear end of the dust box 5, and fastens it with the fastener 48. Then, grasping the handle 33, the worker gradually lifts the base 43 until the wheels 46 of the base 43 touch the ground. The legs 47 and wheels 46 are configured and positioned so that the wheels 46 touch the ground before the legs 47 during this lifting motion.

[0030] By placing the wheels 46 on the ground and pulling the handle 33, the dustbin 5, which is full of construction waste and the like, can be easily transported on its own by the rolling of the wheels 46. Furthermore, by lifting it until it is upright, the wheels 46 leave the floor surface and the legs 47 touch the ground, allowing the dustbin 5, which has been removed from the sweeper body 3, to be placed upright on the floor by itself.

[0031] Furthermore, with the dust box 5 still attached to the sweeper body 3, the sweeper 1 can be easily transported by grasping the handle 33, lifting it up, and placing the wheels 46 of the base 43 on the ground, thereby allowing it to move due to the rolling motion of the wheels 46. By lifting it upright, lifting the wheels 46 off the floor, and placing the legs 47 on 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 multiple ultrasonic distance sensors S1-S18 to detect obstacles in front, to the right, and to the left. The distance sensors S1-S18 are shown as having a separate transmitter and receiver, but they may also be equipped with a single transmitter and receiver. In the following explanation, the term "sensitivity centerline" will be used for each of the distance sensors S1-S18. When the transmitter and receiver are provided as separate units, the sensitivity centerline is defined as the midpoint between the centerline of the transducer's vibration plane passing through the center point of the transducer's vibration plane and perpendicular to the vibration plane, and the centerline of the receiver. In the case of a single transmitter and receiver, it is defined as the centerline of its vibration plane.

[0033] Distance sensors S1-S8 are positioned to detect obstacles to the right of the sweeper body 3. Distance sensors S9-S16 are positioned to detect obstacles to the left of the sweeper body 3. Distance sensors S17 and S18 are positioned to detect obstacles directly in front of the sweeper body 3. Further details are provided below.

[0034] As shown in Figure 7, the distance sensor S1 is positioned at the rear of the sweeper body 3 such that its sensitivity centerline (1) is perpendicular to the centerline 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 Figures 8 and 9(a). The distance sensor S2 is positioned at the front of the sweeper body 3 such that its sensitivity centerline (2) is perpendicular to the centerline 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 S3 is positioned in the center of the sweeper body 3 such that its sensitivity centerline (3) is slightly inclined forward with respect to the centerline 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 positioned in the center of the sweeper body 3 such that its sensitivity centerline (4) is slightly inclined forward with respect to the centerline CL of the sweeper body 3 in a plan view, and is slightly inclined downward in a front view and a side view.

[0035] Distance sensor S8 is positioned at the rear of the sweeper body 3 such that its sensitivity centerline (8) is perpendicular to the centerline 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 Figures 8 and 9(b). Distance sensor S10 is positioned at the front of the sweeper body 3 such that its sensitivity centerline (10) is perpendicular to the centerline CL of the sweeper body 3 in a plan view, and is parallel to the horizontal reference line HL in a front view. Distance sensor S11 is positioned in the center of the sweeper body 3 such that its sensitivity centerline (11) is slightly inclined forward with respect to the centerline CL of the sweeper body 3 in a plan view, and is almost downward in a front view and a side view. Distance sensor S11 is positioned in the center of the sweeper body 3 such that its sensitivity centerline (11) is slightly inclined forward with respect to the centerline CL of the sweeper body 3 in a plan view, and is slightly inclined downward in a front view and a side view.

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

[0037] Distance sensors S5-S8 are positioned so that their sensitivity centerlines (5)-(8) are slightly tilted to the left with respect to the centerline CL of the sweeper body 3 in a plan view. 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 tilted to the right at a 40° angle with respect to the centerline CL. Distance sensors S7 and S8 are installed near the center of the front end of the sweeper body 3 at a certain distance apart so that their sensitivity centerlines (7) and (8) are tilted to the right at a 20° angle with respect to the centerline CL and are parallel to each other.

[0038] Distance sensor S6 (a specific distance sensor) is installed on the left side opposite to distance sensor S5 at the front end of the sweeper body 3, such that its sensitivity center line (6) is tilted 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, preferably intersecting 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) and (16) of distance sensors S14-S16 that detect obstacles on the front left side.

[0039] The same applies to the distance sensors S13-S16 for the front left side. The sensitivity centerlines (13)-(16) of the distance sensors S13-S16 are slightly tilted to the left with respect to the centerline CL of the sweeper body 3 in a plan view. Distance sensor S13 is installed on the left side of the front end of the sweeper body 3 such that its sensitivity centerline (13) is tilted to the left at an angle of 40° with respect to the centerline CL. Distance sensors S15 and S16 are installed near the center of the front end of the sweeper body 3 at a certain distance apart, with their sensitivity centerlines (15) and (16) tilted to the left at an angle of 20° with respect to the centerline CL and 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 such that its sensitivity center line (14) is tilted to the left at an angle of 52.5° with respect to the center line CL, and intersects with the sensitivity center lines (15) and (16) of at least two other distance sensors S15 and S16, preferably intersecting with the sensitivity center lines (13), (15), and (16) of three other distance sensors S13, S15, and S16, and the sensitivity center lines (6) and (8) of distance sensors S6-S8 that detect obstacles on the front right side.

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

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

[0043] As shown in Figures 9(a) and 10(a), in a side view, distance sensors S5 and S6 are mounted at a forward tilt angle such that their sensitivity centerlines (5) and (6) reach the floor surface at a distance (detection reference distance) AD2 from the front end of the sweeper body 3. Distance sensors S5 and S6 detect obstacles that approach within a distance AD2 from the front end of the sweeper body 3. Distance sensor S7 is mounted at a forward tilt angle such that its sensitivity centerline (7) reaches the floor surface at a distance AD1, which is shorter than AD2 from the front end of the sweeper body 3. Distance sensor S7 detects obstacles that approach within a distance AD1 from the front end of the sweeper body 3. Distance sensor S8 is mounted at a forward tilt angle such that its sensitivity centerline (8) reaches the floor surface at a distance AD3, which is longer than AD2 from the front end of the sweeper body 3. Distance sensor S8 detects obstacles that approach within a distance AD3 from the front end of the sweeper body 3. The distance sensor S17 is mounted at a forward-tilting angle so that its sensitivity centerline (17) reaches the floor surface from the front end of the sweeper body 3 at a distance AD4 which is even longer than the distance AD3, and it detects obstacles that approach within the distance AD4.

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

[0045] As shown in Figure 11, among the forward distance sensors S5-S8, S13-S16, S17, and S18, the sensitivity center line (6) of distance sensor S6 (a specific distance sensor) intersects with the sensitivity center lines (7) and (8) of at least two distance sensors S7 and S8. Similarly, the sensitivity center line (14) of distance sensor S14 (a specific distance sensor) intersects with the sensitivity center lines (15) and (16) of at least two distance sensors S15 and S16. Therefore, it is possible to detect construction waste, as well as obstacles such as poles and columns, over a wide area (wide angle) in front of the sensor. Furthermore, even if these obstacles fall between the sensitivity center lines (5), (7), and (8) or between the sensitivity center lines (13), (15), and (16), they can still be detected, significantly reducing blind spots where detection is impossible.

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

[0047] Furthermore, by making the sensitivity centerlines (6) and (7) of distance sensors S6 and S7 intersect at intersections C2 and C3, which are slightly further away from intersection C1, on both the left and right sides of intersection C1 directly in front of sweeper 1, and by making the sensitivity centerlines (14) and (15) of distance sensors S14 and S15 intersect, the blind spots at these intersections C1, C2, and C3 are almost completely eliminated, thereby effectively preventing sweeper 1 from coming into contact with obstacles when turning in place.

[0048] Furthermore, 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 relatively smooth floor surface, and a groove cleaning mode suitable for cleaning the inside of grooves along the direction of the grooves. In each of these modes, the travel area of ​​the sweeper 1 can be set by appropriately arranging multiple shallow pieces of wood (see Figure 12).

[0049] To achieve this, it is necessary to distinguish between the shallow wood and the wall, and to recognize the distance to each of them. In this embodiment, as shown in Figure 13, distance sensor S18 among the forward distance sensors S5-S8, S13-S16, S17, and 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 tilt angles of their sensitivity center lines (5)-(8)((13)-(16)) are different. This simplifies the process of clearly distinguishing between the shallow wood and the wall, and recognizing the distance to each of them.

[0050] Typically, the circuit configuration employs a system that compares the output value of a distance sensor with a reference value corresponding to the respective detection distance using a comparator, and changes the signal processing state when the detection distance falls below the detection reference distance. It is also assumed that the system is pre-configured to change direction when approaching shallow wood at a distance AD3, and when approaching a wall at a distance AD1. In this case, if distance sensors S8, S16, and S17 of the forward distance sensors S5-S8, S13-S16, S17, and S18 show a state change, and the other distance sensors do not show a state change, the control unit (not shown) can recognize that the obstacle is shallow wood and that it has approached at a distance AD3. On the other hand, if all of the forward distance sensors S5-S8, S13-S16, S17, and S18 show a state change, the control unit can recognize that the obstacle is a wall and that it has approached at a distance AD1.

[0051] Let's explain a specific example of operation. For example, as shown in Figure 14(a), sweeper 1 moves along the wall surface, approaching it to a predetermined distance using, for example, distance sensor S10. Then, as shown in Figure 14(b), distance sensor S10 detects the wall surface, and distance sensor S17 detects the presence of an obstacle ahead at a predetermined distance, and distance sensor S18 does not detect an obstacle, the combination of these detection results allows the sweeper to recognize that the obstacle ahead is a piece of wood and that it is a corner between the wall surface and the piece of wood. As shown in Figure 14(c), in accordance with the recognition that the obstacle ahead is a piece of wood and that it is a corner between the wall surface and the piece of wood, the sweeper 1 turns away from the wall surface while maintaining a predetermined distance from the piece of wood, thereby avoiding entry into a restricted area.

[0052] Furthermore, as shown in Figure 15(a), the sweeper 1 moves along the wall surface, approaching it to a predetermined distance using, for example, the distance sensor S10. When the distance sensor S10 detects the wall surface, and as shown in Figure 15(b), when both the distance sensors S17 and S18 detect an obstacle at a predetermined distance ahead, the combination of these detection results allows the sweeper to recognize that the obstacle ahead is a wall surface and specifically a corner of it. When it recognizes that it is a corner of a wall surface, as shown in Figure 15(c), the sweeper 1 moves backward by a predetermined distance, and then, as shown in Figure 15(d), the disc brush 17 approaches the wall surface in front until the bristles reach the wall surface. The backward movement and approach are repeated once or a predetermined number of times. After that, as shown in Figure 15(e), the sweeper 1 rotates 90° and moves along the wall surface. This allows the corner of the wall surface to be cleaned effectively.

[0053] As shown in Figure 16, the floor surface may have recesses called step slabs for installing unit bathrooms or steps at the entrance. The presence of these steps can be detected when the detection distance of distance sensors S3 and S11, whose sensitivity centers are tilted forward from the left and right sides, exceeds a predetermined distance from each sensor to the floor surface. The sweeper 1 recognizes the steps as no-entry areas and can stop and turn as appropriate to avoid falling.

[0054] As described above, according to this embodiment, a sweeper equipped with functions suitable for construction sites, such as a large-capacity dust box, the ability to transport only the dust box separately from the sweeper body and reduce the burden of transporting it, the burden of transporting the entire sweeper, the possibility of malfunctions occurring, the ability to easily and compactly place the dust box alone, and the ability to easily and compactly place the entire sweeper, can be realized without complicating its structure. Furthermore, by providing a tiltable disc brush, it can follow the unevenness of the floor surface, sweeping up and collecting construction waste at the boundary between the floor surface and protruding parts and at the bottom of grooves.

[0055] Furthermore, this embodiment makes it possible to achieve various effects, such as reducing blind spots, without densely deploying a vast number of distance sensors.

[0056] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

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

Claims

1. A sweeper having a sweeper body that moves on the floor surface by front and rear wheels for propulsion and collects garbage, At the front of the sweeper body in the direction of travel, a pair of disc brushes, each with bristles forming a truncated cone shape, are arranged so that the bristles partially overlap each other, with the center line of the sweeper body in between. The sweeper body is equipped with multiple ultrasonic distance sensors for detecting obstacles in front of it. A sweeper in which, among the plurality of distance sensors, a specific distance sensor is positioned such that its sensitivity centerline intersects with the sensitivity centerlines of at least two other distance sensors in a plan view and a front view.

2. The sweeper according to claim 1, further comprising a dustbin for collecting the aforementioned collected waste.

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

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

5. The plurality of distance sensors are arranged such that their sensitivity centerlines are tilted forward when viewed from the side. The sensitivity centerline of the aforementioned specific distance sensor reaches the running surface at a first distance from the front end of the sweeper body. The sensitivity centerline of one of the other two distance sensors reaches the running surface at a distance from the front end of the sweeper body that is shorter than the first distance. The sensitivity centerline of the other of the two other distance sensors reaches the running surface at a distance greater than the first distance from the front end of the sweeper body, The sweeper according to claim 1.

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