Drive unit and automated guided vehicle equipped therewith

Abstract

To easily enable driving with the orientation of the drive unit and the orientation of the vehicle body aligned, and to suppress difficulties in routing the wiring. [Solution] Proximity sensors 24 and 26 are placed on the top plate 10 so that they can detect a stopper block 46 that restricts the rotation limit of the drive unit 12 relative to the top plate 10. When the drive unit 4 is driven in reverse for a short distance, the motors 32a and 34a are driven and controlled based on the detection result of the stopper block 46 by the proximity sensors 24 and 26. This makes it possible to drive the automated guided vehicle 1 with the orientation of the drive unit 4 and the orientation of the vehicle body 2 aligned. Furthermore, since it is not necessary to place a driving sensor at a position far from the drive unit 4, for example at the rear end of the vehicle body 2, it is possible to suppress difficulties in routing the wiring.

Description

Technical Field

[0001] The present invention relates to a drive unit attached to the vehicle body of an automated guided vehicle (AGV) for driving the AGV and an AGV equipped with the same.

Background Art

[0002] Japanese Patent Laid-Open No. 10-63337 (Patent Document 1) describes a drive unit of an AGV including a top plate, a swing plate swingably supported on the top plate via a swing shaft, a cylindrical member disposed on the swing plate, a drive unit having drive wheels and rotatably supported on the swing plate via the cylindrical member, and a travel sensor attached to the drive unit via a bracket.

[0003] Since the drive unit is configured to arrange travel sensors at the front end and the rear end of the drive unit corresponding to the front side and the rear side in the traveling direction when the drive unit travels straight, the drive unit can travel along a guide member not only when it travels forward but also when it travels backward.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In some cases, automated guided vehicles (AGVs) employ fixed wheels positioned at the rear end of the vehicle body to ensure driving stability during forward travel. When such an AGV is equipped with the drive unit described in the aforementioned publication, while the drive unit can be driven along the guide line during reverse travel, the vehicle body itself is pulled by the fixed wheels and gradually deviates from the guide line, resulting in a difference between the orientation of the drive unit and the orientation of the vehicle body. It is also conceivable to place the driving sensor at the rear end of the vehicle body instead of the rear end of the drive unit, but this increases the distance between the drive unit and the driving sensor, making it difficult to control the vehicle body to prevent it from swinging too much from side to side in the direction of travel (reverse direction), and also creating inconveniences such as difficulty in routing the wiring.

[0006] The present invention has been made in view of the above, and one of its objectives is to provide a technology that can easily realize driving with the orientation of the drive unit and the orientation of the vehicle body aligned. Another objective of the present invention is to provide a technology that can suppress the difficulty of routing wiring. [Means for solving the problem]

[0007] The drive unit of the present invention and the automated guided vehicle equipped therewith employ the following means to achieve the above-mentioned objectives.

[0008] The drive unit according to the first invention is mounted on the body of an automated guided vehicle (AGV) and is configured to drive the AGV so that it can travel along a guided track. The drive unit comprises a top plate fastened to the body, a drive unit, a rotating shaft unit connecting the top plate and the drive unit so as to be rotatable relative to each other, a stopper, and first and second sensors. The drive unit has an axle and a drive wheel supported by the axle. The stopper has a block body and first and second contact parts. The block body is positioned on the drive unit so as to be rotatable together with the drive unit as the drive unit rotates relative to the top plate, and has first and second ends in the direction of rotation. The first and second contact parts are positioned on the top plate on the rotational movement trajectory of the block body so as to be able to contact the first and second ends. The first and second sensors are capable of detecting the block body. The first and second sensors are positioned on the top plate so as to be able to detect the first and second ends of the stopper when the first distance from the first end to the first contact point and the second distance from the second end to the second contact point are equal.

[0009] According to the first invention, the orientation of the drive unit and the orientation of the automated guided vehicle (AGV) can be kept constant at all times with a simple configuration that only requires controlling the drive unit so that the first distance to the first contact portion and the second distance from the second end of the stopper to the second contact portion are equal, based on the detection results of the block body of the stopper by the first and second sensors. This allows the AGV to be driven with the orientation of the drive unit and the orientation of the AGV aligned. Furthermore, since it is not necessary to place a driving sensor at a position far from the drive unit, for example at the rear end of the AGV, the difficulty of routing the wiring can also be suppressed.

[0010] The drive unit according to the second invention is the drive unit according to the first invention, wherein the drive unit is supported so as to be movable or oscillating relative to the top plate in the extending direction of the rotation shaft. The block body has a height greater than or equal to the amount of movement or oscillating of the drive unit in the extending direction of the rotation shaft. The first and second sensors are non-contact sensors capable of detecting the block body without contacting it.

[0011] According to the second invention, even in a drive unit configured to absorb vibrations caused by the drive wheels traveling over uneven surfaces and steps on the floor surface on which the guide strip is laid, by the movement or oscillation of the drive unit in the extending direction of the rotating shaft, and to prevent such vibrations from being transmitted to the automated guided vehicle, the detection of block bodies by the first and second sensors can be performed well.

[0012] The automated guided vehicle (AGV) according to the third invention is configured to travel along a guided lane. The AGV comprises a vehicle body, a drive unit according to the first or second invention fastened to the vehicle body via a top plate, at least one auxiliary wheel positioned on the vehicle body, and a control device for controlling the drive unit. When the control device receives a reverse travel instruction to move the AGV in reverse, it controls the drive unit based on the detection results of the first and second sensors so that the direction of the drive unit and the direction of the AGV are aligned.

[0013] According to the third invention, since it is equipped with a drive unit according to either the first or second invention, it can achieve effects similar to those achieved by the drive unit, such as the effect of being able to run the automated guided vehicle with the orientation of the drive unit and the orientation of the vehicle body aligned, and the effect of suppressing difficulties in routing wiring. [Effects of the Invention]

[0014] According to the present invention, it is possible to easily achieve driving with the orientation of the drive unit and the orientation of the vehicle body aligned. Furthermore, according to the present invention, it is possible to suppress difficulties in routing wiring.

Brief Description of the Drawings

[0015] [Figure 1] It is a perspective view of the automated guided vehicle 1 according to an embodiment of the present invention as seen from the upper front side. [Figure 2] It is a side view of the automated guided vehicle 1 according to an embodiment of the present invention as seen from one side in the extending direction of the axis Lc of the axles 36a, 38a. [Figure 3] It is a perspective view of the automated guided vehicle 1 according to an embodiment of the present invention as seen from the bottom side. [Figure 4] It is a perspective view showing the appearance of the drive unit 4 according to an embodiment of the present invention. [Figure 5] It is a side view of the drive unit 4 according to an embodiment of the present invention as seen from one side in the extending direction of the axis Lc of the axles 36a, 38a. [Figure 6] It is a plan view of the drive unit 4 according to an embodiment of the present invention as seen from above. [Figure 7] It is an exploded perspective view showing the state of the drive unit 4 according to an embodiment of the present invention being disassembled. [Figure 8] It is a perspective view of the drive unit 4 according to an embodiment of the present invention as seen from the bottom side. [Figure 9] It is a perspective view showing the appearance of the top plate 10. [Figure 10] It is a plan view of the top plate 10 as seen from above. [Figure 11] It is an exploded perspective view showing the drive part 12 with a part disassembled. [Figure 12] It is an exploded plan view of the drive part 12 with a part disassembled as seen from above. [Figure 13] It is a perspective view showing the appearance of the swing support 40. [Figure 14] It is a side view of the swing support 40 as seen from one side in a direction orthogonal to both the axis of the rotation shaft 60 and the axes of the through holes 43a, 43b. [Figure 15] It is a plan view of the swing support 40 as seen from above. [Figure 16]It is a front view of the swing support 40 as seen from one side in the axial direction of the through holes 43a and 43b. [Figure 17] It is a cross-sectional view showing the W-W cross section of FIG. 6. [Figure 18] It is an explanatory view showing the state in which the drive unit 4 travels backward along the induction band GT. [Figure 19] It is an explanatory view showing the state in which the drive unit 4 has deviated to the left in the backward travel direction from the traveling state along the induction band GT. [Figure 20] It is an explanatory view showing the state in which the drive unit 4 has deviated to the right in the backward travel direction from the traveling state along the induction band GT. [Figure 21] It is an explanatory view showing the positional relationship in the height direction (vertical direction) between the stopper block 46 and the proximity sensors 24 and 26 in the drive unit 4 traveling on a flat floor surface. [Figure 22] It is an explanatory view showing the positional relationship in the height direction (vertical direction) between the stopper block 46 and the proximity sensors 24 and 26 when the drive unit 12 moves up and down along the axis of the rotation shaft 60 with respect to the top plate 10.

Mode for Carrying Out the Invention

[0016] Next, the best mode for carrying out the present invention will be described using examples.

Example

[0017] As shown in FIGS. 1 to 3, the automated guided vehicle 1 according to the present embodiment includes a vehicle body 2, a drive unit 4 supported by the vehicle body 2, a pair of freely rotatable wheels 6, 6 (see FIG. 3) and a pair of fixed wheels 7, 7 (see FIG. 3) supported by the vehicle body 2, and a control device 8 that controls the entire automated guided vehicle 1. Note that the automated guided vehicle 1 according to the present embodiment can travel forward and backward, but for backward travel, only short-distance travel is required. Further, the automated guided vehicle 1 according to the present embodiment is configured as a low-floor type that pulls the cart while潜入 the cart (not shown).

[0018] As shown in Figures 4 to 7, the drive unit 4 includes a top plate 10 fastened to the vehicle body 2 by fastening members such as bolts (not shown), a drive unit 12, a rotating shaft 14 that connects the top plate 10 and the drive unit 12 so as to be rotatable relative to each other, and a lifting mechanism 16 positioned on the top plate 10 so as to be able to move the drive unit 12 up and down. For convenience, in the following description, the left-right direction in Figure 5 is defined as the front-rear direction of the drive unit 4, and in the front-rear direction, the side where the later-described driving sensor 33 is located (left side in Figure 5) is defined as the front side of the drive unit 4, and the opposite side (where the lifting motor 74 of the lifting mechanism 16, described later, is located) is defined as the rear side. Also, the up-down direction in Figure 5 is defined as the up-down direction of the drive unit 4, and in the up-down direction, the side where the top plate 10 is located (upper side in Figure 5) is defined as the upper side of the drive unit 4, and the opposite side (where the later-described drive wheels 36, 38 are located) is defined as the lower side. Furthermore, the direction perpendicular to the front-rear and left-right directions (left-right direction in Figure 6) is defined as the left-right direction of the drive unit 4, and in the left-right direction, the upper side of Figure 6 is defined as the right side of the drive unit 4, and the opposite side (lower side of Figure 6) is defined as the left side of the drive unit 4.

[0019] As shown in Figures 9 and 10, the top plate 10 has a fastening portion 20 that is fastened to the vehicle body 2, and an extension portion 22 that extends integrally from the fastening portion 20. The fastening portion 20 has a substantially circular opening 20a located approximately in the center, a linear notch 20b connected to the opening 20a, and an arc-shaped notch 20c located on the outer circumference of the opening 20a. The linear notch 20b extends in a direction tangential to the opening 20a, in the same direction as and parallel to the extension direction of the extension portion 22, and penetrates from the opening 20a to the rear end of the fastening portion 20 (the right end in Figure 10). The arc-shaped notch 20c is located concentrically with the opening 20a. As shown in Figure 10, the arc-shaped notch 20c is symmetrical with respect to a virtual center line Vcl passing through the center of the fastening portion 20 in the left-right direction, and has notch ends 21a and 21b. A pair of proximity sensors 24 and 26 are also arranged on the top plate 10. The proximity sensors 24 and 26 are arranged symmetrically with respect to the virtual center line Vcl at the front end of the top plate 10 (the left end in Figure 10). The proximity sensors 24 and 26 are arranged so that their sensor central axes 24a and 26a pass through the center Pc1 of the opening 20a. The extension portion 22 supports the lifting motor 74 of the lifting mechanism 16, which will be described later, that allows the drive unit 12 to be raised and lowered. The notch ends 21a and 21b are examples of implementation configurations corresponding to the "first contact portion" and "second contact portion" in the present invention, respectively. Furthermore, proximity sensor 24 corresponds to the "first sensor" and "non-contact sensor" in the present invention, and proximity sensor 26 is an example of an embodiment corresponding to the "second sensor" and "non-contact sensor" in the present invention.

[0020] As shown in Figure 7, the drive unit 12 includes a base frame 30, drive motor units 32 and 34 housed and supported within the base frame 30, drive wheels 36 and 38 rotatably supported by the drive motor units 32 and 34 via axles 36a and 38a, and a swing support 40 that swingably supports the base frame 30.

[0021] As shown in Figure 11, the base frame 30 has an opening 31a on its upper surface 30a, and insertion portions 31b and 31c on its front surface 30b and rear surface 30c, respectively. A driving sensor 33 and a pair of marker sensors 35, 35 are arranged on the front surface 30b. The driving sensor 33 is positioned approximately in the center of the front surface 30b in the left-right direction. The marker sensors 35, 35 are positioned on both sides of the driving sensor 33 in the left-right direction, flanking the driving sensor 33. As shown in Figure 12, the insertion portions 31b and 31c have an axis line Vax that extends in the front-rear direction (up-down direction in Figure 12) of the drive unit 4. In other words, in a plan view, the axis line Vax is perpendicular to both the axis line Lc of the axles 36a, 38a and the normal Lv of the upper surface 30a passing through the center Pc2 of the opening 31a. The pivot shafts 45a and 45b, which will be described later, are inserted through the insertion portions 31b and 31c (see Figures 7 and 17).

[0022] As shown in Figure 8, the drive motor units 32 and 34 each have motors 32a and 34a and gearboxes 32b and 34b that are mechanically connected to the motors 32a and 34a. As shown in Figures 8, 11, and 12, the drive motor units 32 and 34 have a roughly L-shape in plan view. As shown in Figure 12, the drive motor units 32 and 34 are arranged point-symmetrically with respect to the center Pc2 of the opening 31a. When the drive motor units 32 and 34 are housed and supported within the base frame 30, a spatial region SA surrounded by the drive motor units 32 and 34 is formed within the base frame 30. The gearboxes 32b and 34b transmit power from the motors 32a and 34a to the drive wheels 36 and 38 via the axles 36a and 38a.

[0023] As shown in Figure 13, the rocking support 40 has a main plate 42 having a circular hole 42a in the center and a holder 44 integrated with the main plate 42. As shown in Figure 14, the main plate 42 has bent portions 42b and 42c at its front end (left end in Figure 14) and rear end (right end in Figure 14), which are bent downward (downward in Figure 14) at approximately 90 degrees. The bent portions 42b and 42c have through holes 43a and 43b, as shown in Figures 13, 14, and 16. The main plate 42 also has a stopper block 46 for defining the rotation limit of the drive unit 12 relative to the top plate 10. As shown in Figures 13 and 15, the stopper block 46 is positioned on the bent portion 42b side with respect to the circular hole 42a. As shown in Figure 15, the stopper block 46 has a substantially arc shape in plan view and is arranged concentrically with the circular hole 42a on the outer circumference of the circular hole 42a. As shown in Figures 15 and 16, the stopper block 46 has arc ends 46a and 46b at its circumferentially extending ends. The rotation of the drive unit 12 relative to the top plate 10 is restricted by the contact of these arc ends 46a and 46b with the notch ends 21a and 21b of the arc-shaped notch 20c of the top plate 10, respectively. The stopper block 46 has a height (vertical dimension in Figure 14) greater than the amount of movement of the drive unit 12 relative to the top plate 10 along the axial direction of the rotation axis 60, which will be described later. As shown in Figures 13 and 14, the holder 44 has a box shape with an opening at the top (upper part in Figures 13 and 14) and a closed bottom (lower part in Figures 13 and 14). The bottom wall 44a of the holder 44 has the rotating shaft 60 of the rotating shaft portion 14, which will be described later, integrated into it. The stopper block 46 corresponds to the "block body" in the present invention, and the arc ends 46a and 46b are examples of implementations corresponding to the "first end" and "second end" in the present invention, respectively. Furthermore, the stopper block 46 and the notched ends 21a and 21b are examples of implementations corresponding to the "stopper" in the present invention.

[0024] The oscillating support 40, thus configured, supports the base frame 30 so that it can swing around the oscillating axes 45a and 45b (axis line Vax) as the pivot point, by inserting the oscillating axes 45a and 45b into the insertion parts 31b and 31c through the through holes 43a and 43b. When the oscillating support 40 is supporting the base frame 30 so that it can swing around, the holder 44 is housed within the spatial region SA (see Figure 17).

[0025] As shown in Figure 17, the rotating shaft portion 14 includes a rotating shaft 60, a bearing 62 positioned on the outer circumference of the rotating shaft 60, a lifting plate 63 integrated with the shaft end 60a of the rotating shaft 60, a bearing retaining cylinder 64 positioned on the outer circumference of the bearing 62, and a coil spring 66 positioned between the rotating shaft 60 and the bearing retaining cylinder 64. That is, the rotating shaft 60, the bearing 62, and the bearing retaining cylinder 64 are arranged in this order from the inside out, so that they are substantially coaxial.

[0026] As shown in Figure 17, the rotating shaft 60 has a shaft portion 60b and a flange portion 60c integrated with the shaft portion 60b. The flange portion 60c is located at the end opposite to the shaft end portion 60a. The rotating shaft 60 thus configured is housed inside the holder 44, and the flange portion 60c is fastened to the holder 44 by fastening members such as bolts, thereby integrating it with the holder 44. The bearing 62 has a cylindrical shape and is located on the outer circumference of the rotating shaft 60 (shaft portion 60b) and on the inner circumference of the bearing retaining cylinder 64. In other words, the bearing 62 holds the rotating shaft 60 so that it can rotate relative to the bearing retaining cylinder 64 and move relative to the axial direction. The bearing 62 is located inside the small-diameter cylinder 64b of the bearing retaining cylinder 64, which will be described later.

[0027] As shown in Figure 14, the bearing retaining cylinder 64 has a stepped cylindrical shape with a large diameter cylinder 64a and a small diameter cylinder 64b integrated with the large diameter cylinder 64a, and the large diameter cylinder 64a is fastened to the lower surface 10a of the top plate 10 by fastening members such as bolts. The coil spring 66 is positioned between the flange portion 60c and the stepped surface of the bearing retaining cylinder 64 (the stepped surface formed at the connection between the large diameter cylinder 64a and the small diameter cylinder 64b). The coil spring 66 acts a spring force on the shaft portion 60b and the bearing retaining cylinder 64 in a direction that moves them away from each other.

[0028] As shown in Figure 6, the lifting mechanism 16 includes a lifting arm 70, an eccentric cam 72 to which the lifting arm is connected, and a lifting motor 74 having a rotating shaft (not shown) connected to the eccentric cam 72. As shown in Figure 7, one end of the lifting arm 70 in the longitudinal direction is connected to the eccentric cam 72 by a pivot shaft 70a. A link portion 71 is pivotably connected to the other end of the lifting arm 70 in the longitudinal direction. The lifting arm 70 is supported on the top plate 10 via a bracket 73 that pivotably supports the link portion 71. The link portion 71 engages with the lifting plate 63. The lifting motor 74 is supported on the top plate 10. In the lifting mechanism 16 thus configured, when the lifting motor 74 is driven, the eccentric cam 72 rotates, and as the lifting arm 70 swings in accordance with the rotation of the eccentric cam 72, the link portion 71 swings. The swinging of the link portion 71 causes the drive unit 12 to move up and down relative to the top plate 10 via the lifting plate 63.

[0029] The control device 8 is configured as a microprocessor centered on a CPU, and in addition to the CPU, it includes a ROM for storing processing programs, a RAM for temporarily storing data, and input / output ports and communication ports (not shown). The control device 8 receives inputs via its input ports, including position deviation signals from the driving sensor 33, command signals from marker sensors 35, 35, detection signals from proximity sensors 24, 24, object detection signals from obstacle sensors (not shown), signals necessary for managing the battery (not shown) (for example, inter-terminal voltage from voltage sensors (not shown) installed between the terminals of the battery (not shown) and current detected by current sensors (not shown), rotational speeds of the drive wheels 36, 38 from rotational speed sensors (not shown), and steering angles of the drive unit 4 from angle sensors (not shown). The control device 8 also outputs drive signals to motors 32a, 34a and the lifting motor 74, and operation signals to the towing hook (not shown), via its output ports.

[0030] The drive unit 4, thus configured, is assembled by assembling the drive unit 12, fastening the rotating shaft 60 to the holder 44, inserting the bearing retaining cylinder 64, which has a coil spring 66 and a bearing 62 integrated into it, onto the rotating shaft 60 in that order, attaching the lifting plate 63 to the shaft end 60a of the rotating shaft 60, fastening the bearing retaining cylinder 64 to the top plate 10, and fastening the lifting mechanism 16 to the top plate 10. Here, as shown in Figure 18, when the drive unit 4 is assembled and viewed from above in the vertical direction, the virtual center line Vcl (see also Figures 9 and 10) passing through the center of the top plate 10 (fastening portion 20) in the left-right direction coincides with the axes of the pivot shafts 45a and 45b (the axes Vax of the insertion portions 31b and 31c, see also Figure 12) (this also means that the distance from the arc end 46a to the notched end 21a is equal to the distance from the arc end 46b to the notched end 21b), in which case the proximity sensor 24 can detect the arc end 46a of the stopper block 46, and the proximity sensor 26 can detect the arc end 46b of the stopper block 46. Furthermore, by fastening the top plate 10 to the vehicle body 2 with fastening members such as bolts, the drive unit 4 is assembled to the automated guided vehicle 1 in a state in which the drive unit 12 can rotate relative to the vehicle body 2 (top plate 10) with the rotation axis 60 as the center of rotation, the drive unit 12 can move in a direction toward or away from the vehicle body 2 (top plate 10) along the axial direction of the rotation axis 60, and the drive unit 12 can swing relative to the vehicle body 2 (top plate 10) with the axis Vax as the center of oscillation. As a result, the automated guided vehicle 1 can be driven along the guided zone GT, and even on floor surfaces with unevenness or steps, the drive wheels 36 and 38 can follow the unevenness or steps, and vibrations caused by the unevenness or steps can be absorbed by the drive unit 4 and effectively prevented from being transmitted to the automated guided vehicle 1. The distance from the arc end 46a to the notched end 21a corresponds to the "first distance" in the present invention, and the distance from the arc end 46b to the notched end 21b corresponds to the "second distance" in the present invention. This is an example of an implemented configuration.

[0031] Next, the operation of the automated guided vehicle 1 configured in this way, in particular, the operation of the drive unit 4 when the automated guided vehicle 1 is to move backward for a short distance, will be explained. For example, when the trolley is towed to a predetermined location, and then the engagement with the trolley is released, allowing only the automated guided vehicle 1 to move to the next predetermined location, when the control device 8 receives a reverse movement instruction to move the automated guided vehicle 1 backward for a short distance, the control device 8 outputs drive signals to the motors 32a and 34a so that the rotation direction of the drive wheels 36 and 38 rotates in the opposite direction to when the automated guided vehicle 1 is moving forward, and also performs a process to receive detection signals from the proximity sensors 24 and 26 instead of receiving position deviation signals from the travel sensor 33. Then, based on the detection signals from the proximity sensors 24 and 26, the control device 8 outputs drive signals to the motors 32a and 34a so that the orientation of the drive unit 4 matches the orientation of the automated guided vehicle 1 (vehicle body 2).

[0032] Specifically, as shown in Figure 19, if the drive unit 4 shifts to the left in the direction of reverse travel relative to the vehicle body 2, the proximity sensor 24 will no longer detect the stopper block 46. Therefore, it outputs a drive signal to motors 32a and 34a so that the rotation speed of the drive wheel 36 becomes faster than the rotation speed of the drive wheel 38. On the other hand, as shown in Figure 20, if the drive unit 4 shifts to the right in the direction of reverse travel relative to the vehicle body 2, the proximity sensor 26 will no longer detect the stopper block 46. Therefore, it outputs a drive signal to motors 32a and 34a so that the rotation speed of the drive wheel 38 becomes faster than the rotation speed of the drive wheel 36. The drive control of motors 32a and 34a is carried out until both proximity sensors 24 and 26 detect the stopper block 46.

[0033] In this way, with a simple configuration and control that only involves detecting the stopper block 46 using proximity sensors 24 and 26, the automated guided vehicle 1 can be made to move in reverse for a short distance while the orientation of the drive unit 4 and the orientation of the automated guided vehicle 1 are aligned. This eliminates the need to install a dedicated travel sensor at the rear end of the vehicle body 2, which is located far from the drive unit 4, solely for short-distance reverse movement. As a result, the difficulty of routing wiring can also be suppressed.

[0034] Furthermore, since the stopper block 46 has a height greater than the amount of movement of the drive unit 12 along the axial direction of the rotation axis 60 relative to the top plate 10, even if the drive unit 4 moves along the axial direction of the rotation axis 60 relative to the top plate 10 (even if vertical vibration acts on the drive unit 4) due to the drive unit 4 traveling over a floor surface with unevenness or steps, the stopper block 46 can be detected by the proximity sensors 24 and 26, as shown in Figures 21 and 22. Here, Figure 22(a) is an explanatory diagram showing the positional relationship in the height direction (up and down direction) between the stopper block 46 and the proximity sensors 24, 26 when the drive unit 12 moves upward along the axis of the rotation shaft 60 relative to the top plate 10 (when the drive unit 4 rides up onto a step or protrusion on the floor surface), and Figure 22(b) is an explanatory diagram showing the positional relationship in the height direction (up and down direction) between the stopper block 46 and the proximity sensors 24, 26 when the drive unit 12 moves downward along the axis of the rotation shaft 60 relative to the top plate 10 (when the drive unit 4 falls into a step or recess on the floor surface).

[0035] This makes it possible to make short-distance reverse travel more stable when the orientation of the drive unit 4 and the orientation of the automated guided vehicle 1 are aligned. Furthermore, since non-contact type proximity sensors 24 and 26 are used as sensors to detect the stopper block 46, no friction occurs between the proximity sensors 24 and 26 and the stopper block 46. This prevents a decrease in the durability of related parts and enables stable sensing performance.Here, since the stopper block 46 that restricts the rotation of the drive unit 12 relative to the top plate 10 is used as the object to be detected, it is possible to suppress an increase in the number of parts.

[0036] When the control device 8 receives a forward movement instruction to move the automated guided vehicle 1 forward, the control device 8 outputs drive signals to the motors 32a and 34a so that the drive unit 4 moves forward along the guide zone GT, based on the position deviation signal from the travel sensor 33.

[0037] As described above, the drive unit 4 according to this embodiment is configured such that proximity sensors 24 and 26 are placed on the top plate 10 so as to be able to detect the stopper block 46 placed on the rocking support 40, and when the drive unit 4 is to travel in reverse over a short distance, the motors 32a and 34a are driven and controlled based on the detection result of the stopper block 46 by the proximity sensors 24 and 26 placed on the top plate 10. Therefore, in an automated guided vehicle 1 that is only required to travel in reverse over a short distance, the automated guided vehicle 1 can be driven with the orientation of the drive unit 4 and the orientation of the vehicle body 2 aligned without the need to provide a separate travel sensor for reverse travel. Furthermore, since it is not necessary to place a travel sensor at a position far from the drive unit 4, for example, at the rear end of the vehicle body 2, the difficulty in routing the wiring can also be suppressed. Here, since the stopper block 46, which restricts the rotation limit of the drive unit 12 relative to the top plate 10, is used as the object to be detected by the proximity sensors 24 and 26, the increase in the number of parts can be suppressed. Furthermore, since the height of the stopper block 46 is set to be greater than the amount of vertical movement of the drive unit 12 relative to the top plate 10 (in the direction along the axis of the rotation shaft 60), even if the drive unit 4 moves vertically relative to the top plate 10 (in the direction along the axis of the rotation shaft 60) due to the drive unit 4 traveling over a floor surface with unevenness or steps (even if vertical vibrations act on the drive unit 4), the proximity sensors 24 and 26 can reliably detect the stopper block 46. In addition, since non-contact type proximity sensors 24 and 26 are used as sensors for detecting the stopper block 46, no friction occurs between the proximity sensors 24 and 26 and the stopper block 46. This prevents a decrease in the durability of related parts and enables stable sensing performance.

[0038] In this embodiment, the drive unit 12 is pivotably supported on the swing support 40, but the invention is not limited to this configuration. That is, the drive unit 12 may be directly rotatably supported on the top plate 10 via the rotating shaft 14. In this case, the holder 44 and the stopper block 46 can be integrated with the upper surface 30a of the base frame 30.

[0039] In this embodiment, the drive unit 12 is configured to move along the axis of the rotation shaft 60 relative to the top plate 10, but it is not limited to this configuration. For example, it may be configured to pivot with respect to the top plate 10, using a pivot shaft having an axis extending parallel to the axis Lc of the axles 36a and 38a as the pivot center.

[0040] This embodiment illustrates one example of a configuration for carrying out the present invention. Therefore, the present invention is not limited to the configuration of this embodiment. [Explanation of Symbols]

[0041] 1. Automated Guided Vehicle (Automated Guided Vehicle) 2. Vehicle body (vehicle body) 4. Drive Unit (Drive Unit) 6 free wheel 7 Fixed ring 8 Control device (control device) 10. Tabletop (tabletop) 10a Bottom side 12 Drive Unit (Drive Unit) 14. Rotating shaft section (rotating shaft section) 16 Lifting mechanism 20 Fastening part 20a opening 20b Straight notch 20c arc-shaped notch 21a Notched end (first contact part, stopper) 21b Notched end (second contact part, stopper) 22 Extension piece 24. Proximity sensor (first sensor, non-contact sensor) 24a Sensor central axis 26. Proximity sensor (second sensor, non-contact sensor) 26a Sensor central axis 30 Base Frame 30a top surface 30b front 30c rear 31a aperture 31b Insertion section 31c Insertion part 32 Drive motor unit 32a motor 32b Gearbox 33. Driving sensor (driving sensor) 34 Drive motor unit 34a motor 34b Gearbox 35 Marker Sensor 36. Drive wheels (drive wheels) 36a Axle (Axle) 38 Drive wheels (drive wheels) 38a Axle (Axle) 40 Oscillating support 42 Main Plate 42a circular hole 42b Bend part 42c Bend part 43a Through hole 43b Through hole 44 holder 44a bottom wall 45a Oscillating axis 45b Oscillating axis 46 Stopper Block (Block Body, Stopper) 46a Arc end (first end) 46b Arc end (second end) 60 Rotation axis 60a Shaft end 60b Shaft 60c flange section 62 Bearings 63 Lifting Plate 64 Bearing retaining cylinder 64a Large diameter section 64b Small diameter section 66 Coil Springs 70 Lifting Arm 71 Link section 72 Eccentric cam 74 Lifting motor Vcl Virtual Center Line Vax axis Lv normal Pc1 Center of opening 20a Center of Pc2 opening 31a SA spatial domain GT guidance zone (guidance zone)

Claims

1. A drive unit attached to the body of an automated guided vehicle (AGV) that drives the AGV so that it can travel along a guided lane, A top plate fastened to the vehicle body, A drive unit having an axle and a drive wheel supported on the axle, A rotating shaft portion that connects the top plate and the drive unit so that they can rotate relative to each other, A stopper having a block body disposed on the drive unit so as to be rotatable together with the drive unit as the drive unit rotates relative to the top plate, and having first and second ends in the rotational direction, and first and second contact portions on the top plate, which are arranged on the rotational movement trajectory of the block body so as to be able to contact the first and second ends, The block body is detectable, and the stopper is in a state where the first distance from the first end to the first contact portion and the second distance from the second end to the second contact portion are equal, and the first and second sensors are arranged on the top plate so as to be able to detect the first and second ends, A drive unit equipped with the following features.

2. The drive unit is supported so as to be movable or swingable relative to the top plate in the direction in which the rotating shaft extends. The block body has a height greater than or equal to the amount of movement or oscillation of the drive unit in the extending direction of the rotating shaft portion. The first and second sensors are non-contact sensors capable of detecting the block without contacting the block. The drive unit according to claim 1.

3. An unmanned transport vehicle that travels along a guided lane, The car body and, A drive unit according to claim 1 or 2, fastened to the vehicle body via the top plate, The vehicle body is equipped with at least one auxiliary wheel, A control device for controlling the drive unit, Equipped with, When the control device receives a reverse driving instruction to move the automated guided vehicle in reverse, it controls the drive unit to move in a state where the direction of the drive unit and the direction of the automated guided vehicle are aligned, based on the detection results of the first and second sensors. Automated guided vehicle.

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