Steering device and automated guided vehicle equipped therewith

Abstract

To improve transport stability and driving stability while suppressing an increase in size in the height direction. [Solution] A steering wheel unit 18 that rotatably supports the steering wheels 54, 54 is pivotably supported on the steering frame 12 via a pivot shaft 56. This suppresses an increase in the height of the steering device 10 compared to a configuration in which the steering wheel unit 18 is supported on the steering frame 12 so as to be able to move up and down in the direction along the axis Ax2, while also allowing the steering wheels 54, 54 to follow the stepped surfaces Sd1, Sd2 of the floor surface F, even when stepped surfaces Sd1, Sd2 exist on the floor surface F. Furthermore, since the sensor unit 16 moves linearly in the same direction as the movement direction of the steering wheels 54, 54 (parallel to the axis Ax2) as the steering wheel unit 18 pivots, it is possible to effectively suppress changes in the distance D between the travel sensor 44 and the floor surface F, and the angle between the sensing surface 44a of the travel sensor 44 and the floor surface F.

Description

Technical Field

[0001] The present invention relates to a steering device attached to the vehicle body of an automated guided vehicle, which steers the automated guided vehicle so that the automated guided vehicle can travel along a guide strip, and an automated guided vehicle equipped with the same.

Background Art

[0002] Japanese Patent Laid-Open No. 63-231506 (Patent Document 1) describes a steering device including a steering frame rotatably supported on the vehicle body of an automated guided vehicle via a pivot axis, a steering wheel rotatably supported on the steering frame, a steering motor mechanically connected to the steering frame so as to be rotatable, and a traveling sensor disposed on the steering frame so as to be able to detect a guide strip laid on the floor surface.

[0003] Since the detection result by the traveling sensor can be directly reflected in the steering of the steering wheel, stable traveling of the automated guided vehicle along the guide strip can be realized.

[0004] By the way, there are irregularities and steps on the floor surface where the guide strip is laid. From the viewpoint of the conveyance stability of the automated guided vehicle, it is desirable to configure the steering wheel to follow the irregularities and steps so that the up-and-down vibration caused by the steering wheel traveling over the irregularities and steps is not transmitted to the automated guided vehicle. In recent years, there has been an increasing demand for a low-floor automated guided vehicle that pulls a vehicle such as a cart while entering under the vehicle. In such a low-floor automated guided vehicle, since it is necessary to enter a limited space under the vehicle such as a cart, there is a desire to keep the vehicle height (height from the floor surface) of the automated guided vehicle as low as possible.

[0005] In this regard, Japanese Patent Publication No. 7541415 (Patent Document 2) describes a steering device comprising: a fixed plate portion rotatably supported on the body of a transport vehicle via a pivot axis; a pair of support plate portions rotatably supporting caster wheels and pivotably supported on the fixed plate portion via a pivot axis; and a caster pivot drive unit mechanically connected to the fixed plate portion so as to be rotatable. In this steering device, since the pair of support plate portions are pivotably supported on the fixed plate portion, the caster wheels can follow unevenness and steps on the floor surface, and vertical vibrations caused by the caster wheels traveling over such unevenness and steps can be prevented from being transmitted to the transport vehicle. This improves transport stability. Furthermore, compared to a configuration in which the support plate portions are supported on the fixed plate portion so as to be able to move up and down in a direction along the axis of the pivot axis, it is possible to suppress an increase in the size of the steering device in the height direction (axis direction of the pivot axis). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 63-231506 [Patent Document 2] Patent No. 7541415 [Overview of the project] [Problems that the invention aims to solve]

[0007] Here, by applying the configuration described in Patent Document 2 to the steering device described in Patent Document 1, the steering frame has a fixed plate portion that is rotatably supported on the body of the automated guided vehicle via a pivot axis, and a support plate portion that rotatably supports the steering wheels and is pivotably supported on the fixed plate portion via a pivot axis. In this configuration, even with the steering device described in Patent Document 1, it is possible to improve transport stability while suppressing an increase in the size of the steering device in the height direction (axis direction of the pivot axis). However, in this configuration, the positional relationship between the travel sensor placed on the steering frame (fixed plate portion or support plate portion) and the floor surface changes due to the swinging of the support plate portion when the steering wheels travel over unevenness or steps in the floor surface. Specifically, the distance between the travel sensor and the floor surface and the angle of the travel sensor with respect to the floor surface change, which can prevent the travel sensor from fully exhibiting its ability to detect the guide zone and may prevent stable travel along the guide zone of the automated guided vehicle. In this respect, there is room for improvement in ensuring that the automated guided vehicle travels stably along the guide zone.

[0008] The present invention has been made in view of the above, and one of its objectives is to provide a steering device and an automated guided vehicle equipped therewith that can improve transport stability and driving stability while suppressing an increase in size in the height direction. [Means for solving the problem]

[0009] The steering device of the present invention and the automated guided vehicle equipped therewith employ the following means to achieve the above-mentioned objectives.

[0010] The steering device according to the first invention is mounted on the body of an automated guided vehicle (AGV) and is configured to steer the AGV so that it can travel along a guided lane. The steering device comprises a steering frame having a first axis, an actuator mechanically connected to the steering frame, at least one steering wheel having an axle, a first pivot shaft, a steering wheel support, a biasing unit, a travel sensor capable of detecting the guided lane, and a sensor support. The steering frame is supported on the vehicle body so as to be able to rotate with the first axis as its center of rotation. The actuator is capable of rotating the steering frame with the first axis as its center of rotation. The first pivot shaft extends parallel to the axle. The steering wheel support rotatably supports the steering wheel via the axle and is pivotably supported on the steering frame via the first pivot shaft. The biasing section has at least one spring positioned between the steering frame and the steering wheel support, on the side opposite to the side where the axle is positioned with respect to the first pivot axis. The sensor support supports the travel sensor on the steering frame in such a manner that the travel sensor can move linearly in the first direction as the steering wheel support swings so that the steering wheel moves in the first direction of the extending direction of the first axis, and that the travel sensor can move linearly in the second direction as the steering wheel support swings so that the steering wheel moves in the second direction, which is opposite to the first direction.

[0011] According to the first invention, the steering wheel support, which rotatably supports the steering wheel, is pivotably supported on a steering frame rotatably supported on the vehicle body via a first pivot axis. Compared to a configuration in which the steering wheel support is supported on the steering frame so as to be vertically movable in a direction along the first axis, this configuration suppresses an increase in the height of the steering device (in the direction of extension of the first axis) while allowing the steering wheel to follow the unevenness and steps of the floor surface, even when such unevenness or steps exist. This prevents vertical vibrations caused by the steering wheel traveling over the unevenness and steps of the floor surface from being transmitted to the automated guided vehicle (AGV). As a result, the transport stability of the AGV equipped with this steering device can be improved. Furthermore, because the travel sensor can be moved linearly in the same direction as the movement of the steering wheel as the steering wheel support oscillates, changes in the positional relationship between the travel sensor and the floor surface, specifically the distance between the travel sensor and the floor surface and the angle of the travel sensor with respect to the floor surface, can be effectively suppressed. This prevents a decrease in the detection performance of the guidance zone by the driving sensors, thus enabling stable driving of the automated guided vehicle along the guidance zone.

[0012] The steering device according to the second invention is the steering device according to the first invention, wherein the biasing part includes a coil spring as a spring, at least one guide rod capable of guiding the expansion and contraction of the coil spring, a second oscillating shaft extending parallel to the axle and the first oscillating shaft, and a first spring support part to which one end of the coil spring abuts. The steering wheel support has a second spring support part to which the other end of the coil spring abuts. The second spring support part has an insertion hole through which the guide rod can be inserted. One end of the guide rod is inserted through the insertion hole, and the other end of the guide rod is engaged with the second oscillating shaft. The guide rod is also pivotably supported on the steering frame via the second oscillating shaft. The first spring support part is located on the guide rod, near the other end of the guide rod.

[0013] According to the second invention, the guide rod can swing in the same direction as the steering wheel support in conjunction with the swing of the steering wheel support, thereby enabling smooth expansion and contraction of the coil spring along the guide rod in conjunction with the swing of the steering wheel support. This allows the spring force to be applied appropriately to the steering wheel support.

[0014] The steering device according to the third invention is a steering device according to the first or second invention, wherein the guide rod has first and second guide rods arranged parallel to each other. The coil spring has first and second coil springs guided by the first and second guide rods, respectively. The first spring support portion has a third spring support portion located on the first guide rod near the other end of the first guide rod, and a fourth spring support portion located on the second guide rod near the other end of the second guide rod. The other ends of the first and second coil springs can contact the second spring support portion. The through hole has a first through hole through which the first guide rod can be inserted, and a second through hole through which the second guide rod can be inserted.

[0015] According to the third invention, compared to a single coil spring configuration, it is easier to secure the desired spring force while suppressing an increase in the size of the biasing portion.

[0016] The steering device according to the fourth invention is a steering device according to any one of the first to third inventions, further comprising a guide portion capable of guiding the linear movement of a travel sensor in first and second directions. The guide portion has a first elongated hole disposed on the sensor support so as to extend in a direction perpendicular to both the axle and the first axis, at least one second elongated hole disposed on the sensor support so as to extend in the same direction as the extending direction of the first axis, and at least one shaft portion extending parallel to the axle and fixed to the steering frame. The axle is engaged with the first elongated hole, and the shaft portion is engaged with the second elongated hole.

[0017] According to the fourth invention, with a simple configuration in which the axle is engaged with the first elongated hole and the shaft portion is engaged with the second elongated hole, the oscillating motion of the steering wheel support can be converted into linear motion in a direction parallel to the first axis (first and second directions) and transmitted to the driving sensor. This makes it possible to easily ensure a configuration that does not change the positional relationship between the driving sensor and the floor surface (such as the distance between the driving sensor and the floor surface and the angle of the driving sensor with respect to the floor surface).

[0018] The steering device according to the fifth invention is the steering device according to the fourth invention, wherein the second elongated hole has third and fourth elongated holes arranged parallel to each other. The shaft portion has a first shaft portion that engages with the third elongated hole and a second shaft portion that engages with the fourth elongated hole.

[0019] According to the fifth invention, the linear movement of the travel sensor in directions parallel to the first axis (first and second directions) can be made more stable.

[0020] The steering device according to the sixth invention is a steering device according to the fourth or fifth invention, wherein the shaft portion further includes a roller that can roll within a second elongated hole.

[0021] According to the sixth invention, linear movement in a direction parallel to the first axis of the travel sensor (first and second directions) can be performed smoothly.

[0022] According to the seventh invention, an automated guided vehicle (AGV) is configured that can transport an object to a predetermined location. The AGV comprises a vehicle body, a drive unit disposed on the vehicle body, at least one auxiliary wheel disposed on the vehicle body, a steering device according to any one of the first to sixth inventions described above, fastened to the vehicle body, and a control device that controls the drive unit and the steering device. The drive unit comprises a drive wheel and a motor mechanically connected to the drive wheel.

[0023] According to the seventh invention, since the steering device according to any one of the first to sixth inventions is provided, the same effects as those of the steering device can be achieved, for example, an effect of improving the conveyance stability and running stability while suppressing the increase in size in the height direction can be achieved.

Effects of the Invention

[0024] According to the present invention, it is possible to provide a steering device capable of improving the conveyance stability and running stability while suppressing the increase in size in the height direction, and an automated guided vehicle equipped with the same.

Brief Description of the Drawings

[0025] [Figure 1] It is a perspective view showing the appearance of the automated guided vehicle 1 according to an embodiment of the present invention. [Figure 2] It is a cross-sectional view showing the A-A cross section of FIG. [Figure 3] It is a bottom view of the automated guided vehicle 1 according to an embodiment of the present invention as viewed from the bottom side. [Figure 4] It is a perspective view showing the appearance of the steering device 10 according to an embodiment of the present invention. [Figure 5] It is a side view of the steering device 10 according to an embodiment of the present invention as viewed from one side in the extending direction of the axle 54a. [Figure 6] It is a rear view of the steering device 10 according to an embodiment of the present invention as viewed from the direction of arrow V in FIG. [Figure 7] It is an exploded perspective view of the steering device 10 according to an embodiment of the present invention as viewed from above the front. [Figure 8] It is an exploded perspective view of the steering device 10 according to an embodiment of the present invention as viewed from above the rear. [Figure 9] It is a perspective view showing the appearance of the steering frame 12. [Figure 10] It is a front view as viewed from the direction of arrow W in FIG. [Figure 11] It is a side view showing the side surface of the steering frame 12. [Figure 12]This is a perspective view of the sensor unit 16 from above, on the side of the driving sensor 44. [Figure 13] This is a perspective view of the sensor unit 16 from above, opposite to the side of the driving sensor 44. [Figure 14] This is a side view of the sensor unit 16, seen from the side. [Figure 15] This is an explanatory diagram showing how the sensor unit 16 is assembled to the steering frame 12. [Figure 16] Figure 15 is a cross-sectional view showing the TT section. [Figure 17] This is a perspective view of the steering wheel unit 18 from above, on the side of the biasing unit 58. [Figure 18] This is a perspective view of the steering wheel unit 18, seen from above on the side of the steering wheels 54, 54. [Figure 19] This is a perspective view showing the appearance of the steering wheel bracket 50. [Figure 20] This is a side view of the steering wheel bracket 50, seen from the side. [Figure 21] This is an exploded perspective view showing the general configuration of the biasing unit 58. [Figure 22] This is a perspective view of the steering device 10 from the bottom. [Figure 23] This is an explanatory diagram showing the support state of the sensor unit 16 and the steering wheel unit 18 to the steering frame 12. [Figure 24] This is an explanatory diagram showing how the steering device 10 travels on a flat floor surface F. [Figure 25] This is an explanatory diagram showing how the steering device 10 travels over a stepped surface Sd1 that is higher than the flat floor surface F. [Figure 26] This is an explanatory diagram showing how the steering device 10 travels over a stepped surface Sd2 that is lower in height than the flat floor surface F. [Modes for carrying out the invention]

[0026] Next, the best mode for carrying out the present invention will be described using examples. [Examples]

[0027] As shown in Figure 1, the automated guided vehicle 1 according to this embodiment is configured as a low-floor type that tows the trolley while positioned beneath it. As shown in Figures 2 and 3, the automated guided vehicle 1 comprises a vehicle body 2, a pair of drive units 4, 4 supported on the vehicle body 2, a steering device 10 according to this embodiment supported on the vehicle body 2, four casters 6, 6, 6, 6 rotatably supported on the vehicle body 2, and a control device 8 that controls the entire automated guided vehicle 1. The casters 6, 6, 6, 6 are an example of an implementation configuration corresponding to the "auxiliary wheels" in the present invention.

[0028] As shown in Figure 3, the drive unit 4 includes a drive wheel 4a, a motor 4b, and a gearbox 4c that connects the drive wheel 4a and the motor 4b.

[0029] As shown in Figures 4 to 8, the steering device 10 according to this embodiment includes a steering frame 12, a motor unit 14 mechanically connected to the steering frame 12 so as to be rotatable, a sensor unit 16 supported by the steering frame 12, and a steering wheel unit 18 supported by the steering frame 12. For convenience, in the following description, the left-right direction in Figure 5 is defined as the front-rear direction of the steering device 10, and in the front-rear direction, the side where the later-described driving sensor 44 is located (left side in Figure 5) is defined as the front side of the steering device 10, and the opposite side (where the later-described motor 30 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 steering device 10, and in the up-down direction, the side where the motor unit 14 is located (upper side in Figure 5) is defined as the upper side of the steering device 10, and the opposite side (where the later-described steering wheels 54, 54 are located) is defined as the lower side. Furthermore, the direction perpendicular to the front-rear and left-right directions is defined as the left-right direction of the steering device 10.

[0030] As shown in Figure 9, the steering frame 12 is composed of a first part 20, a second part 22, and a connecting rod 24 that connects the first and second parts, and as shown in Figure 10, it has a roughly inverted U shape when viewed from the front. As shown in Figures 9 and 10, the first and second parts 20 and 22 each have unit support parts 20a and 22a and flange parts 20b and 22b that are integrated with the unit support parts 20a and 22a, respectively. As shown in Figure 11, the unit support parts 20a and 22a have a roughly triangular shape when viewed from the side, with the flange parts 20b and 22b as the base. The unit support parts 20a and 22a each have through holes 21a and 23a, through holes 21b and 23b, and a pair of through holes 21c, 21c, 23c, and 23c, respectively. The through holes 21a and 23a are located at the apex of the unit support sections 20a and 22a (where the two hypotenuses intersect, excluding the base), and are arranged in the order of through holes 21b and 23b, and a pair of through holes 21c, 21c, 23c, and 23c, along the longest hypotenuse toward the base. The connecting rod 24 is located at the base of the unit support section (where the longest hypotenuse intersects with the base). As shown in Figures 9 and 10, the flange sections 20b and 22b are perpendicular to the unit support sections 20a and 22a and extend toward each other. The flange sections 20b and 22b are fastened to the rotating body 32 of the motor unit 14, which will be described later. As a result, the steering frame 12 is supported by the vehicle body 2 so that it can rotate around the axis Ax2, which will be described later, via the motor unit 14 and the rotating body 32 (see Figures 7 and 8).

[0031] As shown in Figures 4 to 8, the motor unit 14 consists of a motor 30, a rotating body 32, and a gearbox 34 connecting the motor and the rotating body 32. The motor 30 has a rotating shaft (not shown) with a bevel gear (hereinafter referred to as the "motor-side bevel gear") integrated at its tip. The rotating body 32 can use bearings, for example, and is fastened to the bevel gear (gearbox-side bevel gear) of the gearbox 34 (described later) in a state where it is coaxial with the gearbox-side bevel gear. In other words, the rotating body 32 rotates around the axis Ax2 of the bevel gear (gearbox-side bevel gear) of the gearbox 34 (see Figure 5). As shown in Figures 4 to 8, the gearbox 34 has flange portions 34a, 34a, 34a, 34a, and is fastened to the vehicle body 2 via these flange portions 34a, 34a, 34a, 34a. In other words, the steering device 10 is integrated with the vehicle body 2 by fastening the flange portions 34a, 34a, 34a, 34a to the vehicle body 2. The gearbox 34 also has a bevel gear (not shown) that meshes with a motor-side bevel gear (not shown). The gearbox-side bevel gear (not shown) has a larger outer diameter than the motor-side bevel gear (not shown) and has more teeth than the motor-side bevel gear (not shown). As shown in Figure 5, the gearbox-side bevel gear (not shown) has an axis Ax2 that is perpendicular to the axis Ax1 of the motor-side bevel gear (not shown) (which is also the axis of the rotation axis of the motor 30 (not shown)). Specifically, the gearbox 34 reduces the rotational speed of the motor 30's rotating shaft (not shown) by a predetermined reduction ratio, and also changes the direction of the rotational motion of the motor 30's rotating shaft (not shown) by 90 degrees (changing it to rotation with axis Ax2 as the center of rotation) before transmitting it to the rotating body 32. The motor unit 14 is an example of an embodiment corresponding to the "actuator" in the present invention. Ax line Ax2 is also an example of an embodiment corresponding to the "first axis" in the present invention.

[0032] As shown in Figures 12 and 13, the sensor unit 16 includes a pair of plate portions 40, 40, a connecting portion 42 that connects the pair of plate portions 40, 40, and a travel sensor 44 supported by the connecting portion 42. The plate portions 40, 40 have a roughly L-shape in side view, having elongated extension pieces 40a, 40a and guide pieces 40b, 40b integrated with one end of the extension pieces 40a, 40a in the longitudinal direction (the end opposite to the side to which the connecting portion 42 is connected) (see Figure 14). The guide pieces 40b, 40b are roughly perpendicular to the extension pieces 40a, 40a and extend downward from the extension pieces 40a, 40a (downward in Figures 12 and 13). Each of the guide pieces 40b, 40b has a pair of vertically elongated holes 41a, 41a and one horizontally elongated hole 41b. The vertically elongated holes 41a, 41a extend from approximately the center of the extension direction of the guide pieces 40b, 40b to the upper end (the upper end in Figure 14), and are arranged parallel to each other in the longitudinal direction of the extension pieces 40a, 40a. The horizontally elongated hole 41b is located at the lower end (the lower end in Figure 14) in the extension direction of the guide pieces 40b, 40b, i.e., below the vertically elongated holes 41a, 41a, and extends in the longitudinal direction of the extension pieces 40a, 40a. As shown in Figure 14, the connecting portion 42 has a roughly L-shape in side view, having a first piece 42a and a second piece 42b integrated with the first piece 42a, and is located at the longitudinal extension end of the extension pieces 40a, 40a (the end opposite to the side where the guide pieces 40b, 40b are integrated). As shown in Figure 14, the connecting portion 42 is arranged such that the second piece 42b extends in the same direction as the extending direction of the guide pieces 40b, 40b. The travel sensor 44 is located at the tip of the second piece 42b. The travel sensor 44 can be a magnetic sensor capable of detecting the induction band Gb, which is composed of, for example, magnetic tape. The plate portions 40, 40 and the connecting portion 42 are examples of implementation configurations corresponding to the "sensor support" in the present invention. The vertically elongated holes 41a, 41a correspond to the "guide portion" and "second elongated hole" in the present invention, and the horizontally elongated hole 41b is an example of an implementation configuration corresponding to the "guide portion," "first elongated hole," "third elongated hole," and "fourth elongated hole" in the present invention.

[0033] The sensor unit 16, configured in this way, is supported by guide supports 47, 47 on the steering frame 12, as shown in Figures 15 and 16, while positioned inside the steering frame 12, specifically between the unit support portions 20a, 22a of the steering frame 12. The guide supports 47 have a pair of guide shafts 48, 48, a pair of rollers 48a, 48a rotatably supported on the guide shafts 48, and a bracket 49 connecting the pair of guide shafts 48, 48. The rollers 48a, 48a have an outer diameter that is the same as or slightly smaller than the width dimension of the through holes 21c, 23c. The guide shafts 48, 48 are an example of an embodiment corresponding to the "guide portion," "shaft portion," "first shaft portion," and "second shaft portion" in the present invention.

[0034] The sensor unit 16 is supported on the steering frame 12 by the guide supports 47,47 by fitting the guide shafts 48,48 through the elongated holes 41a,41a of the unit support parts 20a,22a from the inside of the plate parts 40,40 of the sensor unit 16 into the through holes 21c,21c,23c,23c of the unit support parts 20a,22a, as shown in Figures 15 and 16 (only the through holes 23c,23c are shown in Figure 15). Here, the rollers 48a,48a are positioned within the elongated holes 41a,41a when the guide shafts 48,48 are fitted into the through holes 21c,21c,23c,23c. In this way, the sensor unit 16 is supported on the steering frame 12 so as to be able to move linearly in a direction parallel to the axis Ax2, guided by the guide shafts 48,48 (rollers 48a,48a) engaged with the elongated holes 41a,41a.

[0035] As shown in Figures 17 and 18, the steering wheel unit 18 includes a steering wheel bracket 50, a pair of steering wheels 54, 54 rotatably supported on the steering wheel bracket 50 via an axle 54a, a pivot shaft 56 rotatably supported on the steering wheel bracket 50 via bearings 56a, 56a, and a biasing part 58.

[0036] As shown in Figure 19, the steering wheel bracket 50 is composed of a pair of steering wheel support pieces 51, 51 and a connecting piece 52 that connects the steering wheel support pieces 51, 51. As shown in Figure 20, the steering wheel support pieces 51, 51 have a roughly V-shape in side view. The steering wheel support pieces 51, 51 have axle insertion holes 51a, 51a through which the axle 54a is inserted, and oscillating shaft insertion holes 51b, 51b through which the oscillating shaft 56 is inserted. The axle insertion holes 51a, 51a are located at the tip of the steering wheel support pieces 51, 51 (the end of the steering wheel support pieces 51, 51 opposite to the end to which the connecting piece 52 is integrated). The oscillating shaft insertion holes 51b, 51b are located at the approximate center of the steering wheel support pieces 51, 51 in the extending direction (closer to the tip than the bent part of the V-shape). The connecting piece 52 has a pair of through holes 52a, 52a, as shown in Figure 19. The through holes 52a, 52a have an inner diameter larger than the outer diameter of the spring guide rods 60, 60 of the biasing portion 58, which will be described later. The steering wheel bracket 50 is an example of an implementation corresponding to the "steering wheel support" in the present invention. The through holes 52a, 52a are also an example of an implementation corresponding to the "insertion hole," "first insertion hole," and "second insertion hole" in the present invention.

[0037] The oscillating shaft 56 has an outer diameter smaller than the inner diameter of the oscillating shaft insertion holes 51b, 51b (see Figure 19). The oscillating shaft 56 is inserted through the oscillating shaft insertion holes 51b, 51b and is rotatably supported by the steering wheel bracket 50 via bearings 56a, 56a (see Figures 18 and 19). The oscillating shaft 56 is arranged parallel to the axle 54a, as shown in Figures 17 and 18. The oscillating shaft 56 is an example of an embodiment corresponding to the "first oscillating shaft" in the present invention.

[0038] As shown in Figure 21, the biasing unit 58 includes a pair of spring guide rods 60, 60, coil springs 62, 62 inserted through the spring guide rods 60, 60, spring receiving parts 64, 64 positioned at one axial end of the spring guide rods 60, 60 (the lower end in Figure 21), a pivot shaft 66 positioned at one axial end of the spring guide rods 60, 60 (the lower end in Figure 21) below the spring receiving parts 64, 64 (the lower side in Figure 21), and a connecting bracket 68 connecting the other axial end of the spring guide rods 60, 60 (the upper end in Figure 21). The pivot shaft 66 is integrated with the pair of spring guide rods 60, 60 in a manner perpendicular to the pair of spring guide rods 60, 60. The spring guide rods 60, 60 correspond to the "guide rod," "first guide rod," and "second guide rod" in the present invention, and the coil springs 62, 62 are examples of implementations corresponding to the "spring," "coil spring," "first coil spring," and "second coil spring" in the present invention. Furthermore, the spring support portion 64 is an example of implementations corresponding to the "first spring support portion," "third spring support portion," and "fourth spring support portion" in the present invention. In addition, the oscillating shaft 66 is an example of implementations corresponding to the "second oscillating shaft" in the present invention.

[0039] Here, the biasing section 58 is assembled to the steering wheel bracket 50, as shown in Figures 17 and 18. Specifically, as shown in Figure 21, the biasing section 58 is sub-assembled by integrating the spring receiving sections 64, 64 and the pivot shaft 66 with a pair of spring guide rods 60, 60, and inserting coil springs 62, 62 from the ends of the pair of spring guide rods 60, 60 (the ends opposite to the side where the pivot shaft 66 is integrated). Next, the sub-assembled biasing section 58 is positioned below the steering wheel bracket 50 (below in Figures 17 and 18, below the connecting piece 52) so that the spring guide rods 60, 60 align with the through holes 52a, 52a of the steering wheel bracket 50. The tips of the spring guide rods 60, 60 (the ends opposite to the side to which the pivot shaft 66 is integrated) are then inserted into the through holes 52a, 52a from below, while compressing the coil springs 62, 62. At this time, the coil springs 62, 62 are compressed between the inner surface 52b of the connecting piece 52 and the spring receiving sections 64, 64 (see Figure 22). In other words, the spring force (restoring force) of the coil springs 62, 62 is constantly acting on the steering wheel bracket 50 in the direction that causes the steering wheels 54, 54 to swing downward (downward in Figure 23), that is, in the direction of arrow Rd2 in Figure 23 (clockwise in Figure 23). As a result, a force is constantly acting on the steering wheels 54, 54 in the direction that presses them against the floor surface F. This improves the driving stability of the steering wheels 54, 54. The inner surface 52b is an example of an embodiment corresponding to the "second spring support portion" in the present invention.

[0040] Finally, the assembly of the steering wheel bracket 50 is completed by connecting the ends of the spring guide rods 60, 60 protruding from the through holes 52a, 52a (the ends opposite to the side to which the pivot shaft 66 is integrated) with the connecting bracket 68. In this state, the pivot shaft 66 is positioned parallel to the axle 54a and the pivot shaft 56.

[0041] As shown in Figures 17 and 18, the steering wheel unit 18 is positioned inside the sensor unit 16, specifically between the plate portions 40, 40, and is supported by the sensor unit 16 by the axle 54a being inserted through the elongated holes 41b, 41b via the bush 55. Furthermore, as shown in Figures 22 and 23, the steering wheel unit 18 supported by the sensor unit 16 is positioned inside the steering frame 12, specifically between the unit support portions 20a, 22a of the steering frame 12, and is supported by the steering frame 12 by the oscillating shaft 56 being fitted into the through holes 21b, 23b of the steering frame 12 and the oscillating shaft 66 being inserted through the through holes 21a, 23a of the steering frame 12. The oscillating shaft 56 has an outer diameter that is the same as or slightly smaller than the inner diameter of the through holes 21b, 23b (see Figures 22 and 23). The pivot shaft 56 is fitted into the through holes 21b and 23b. In other words, the steering wheel unit 18 is supported by the steering frame 12 so as to be able to pivot with the pivot shaft 56 as the pivot point (see Figure 23).

[0042] 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 44, command signals from marker sensors (not shown), 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 speed of drive wheels 4a, 4a from rotational speed sensors (not shown), and steering angle of the steering device 10 from angle sensors (not shown). The control device 8 also outputs drive signals to motors 4b, 4b and motor 30, and operation signals to the tow hook (not shown) via its output ports.

[0043] Next, the operation of the automated guided vehicle 1 configured in this way, in particular the operation of the steering device 10, will be described. First, the operation of the steering device 10 when it is traveling on a flat floor surface F will be described, and then the operation of the steering device 10 when it is traveling on a stepped surface Sd1 that is higher than the floor surface F and a stepped surface Sd2 that is lower than the floor surface F will be described.

[0044] When the steering device 10 travels on a flat floor surface F, as shown in Figure 24, the steering device 10 is positioned such that the centers of the vertically elongated holes 41a, 41a of the sensor unit 16 are approximately aligned with the centers of the guide axes 48, 48 (rollers 48a, 48a) of the guide supports 47, 47, and the centers of the axles 54a, 54a are approximately aligned with the center of the horizontally elongated hole 41b of the sensor unit 16. At this time, the sensing surface 44a of the travel sensor 44 is approximately parallel to the floor surface F, and the distance from the sensing surface 44a to the floor surface F is value D.

[0045] Thus, when the steering system 10, which is traveling on a flat floor surface F, travels over a step surface Sd1 via a step, as shown in Figure 25, the steering wheels 54, 54 ride up onto the step. At this time, the steering wheel bracket 50 swings in the direction of arrow Rd1 in Figure 25 (counterclockwise in Figure 25) with the pivot axis 56 as the pivot center. This swing of the steering wheel bracket 50 in the direction of arrow Rd1 with the pivot axis 56 as the pivot center is performed while compressing the coil springs 62, 62. At this time, a force acts on the biasing unit 58 via the coil springs 62, 62 and spring guide rods 60, 60, causing it to swing in the same direction as the steering wheel bracket 50 with the pivot axis 66 as the pivot center. As a result, the biasing unit 58 swings in the counterclockwise direction in Figure 25. Thus, since the biasing part 58 swings in the same direction as the steering wheel bracket 50 as the steering wheel bracket 50 swings, the swing of the steering wheel bracket 50 accompanied by the compression of the coil springs 62, 62 can be performed smoothly. When the steering device 10 changes direction from the stepped surface Sd1 to the floor surface F, the steering wheel bracket 50 swings in the opposite direction to the direction of arrow Rd1 (the direction of arrow Rd2 in Figure 26, and the clockwise direction in Figures 25 and 26) with the pivot axis 56 as the pivot center, due to the spring force (restoring force) of the coil springs 62, 62.

[0046] As the steering wheel bracket 50 swings in the direction of arrow Rd1, the axles 54a, 54a move within the elongated holes 41b, 41b in the direction extending along the axis Ax2 (upward direction in Figure 25) and in the opposite direction from the side where the travel sensor 44 is located (rightward direction in Figure 25). That is, as the steering wheel bracket 50 swings in the direction of arrow Rd1, the axles 54a, 54a roll backward (rightward in Figure 25) within the elongated holes 41b, 41b while applying an upward force (upward direction in Figure 25) to the sensor unit 16 via the elongated holes 41b, 41b. As a result, the sensor unit 16 moves upward (towards the top of Figure 25). This upward movement of the sensor unit 16 is linear, along the direction of extension of the vertical holes 41a, 41a (parallel to the direction of extension of axis Ax2, which is also the vertical direction), due to the vertical holes 41a, 41a and the guide supports 47, 47 engaged with them. As a result, the travel sensor 44 supported by the sensor unit 16 also moves linearly upward (towards the top of Figure 25). The distance that the sensor unit 16 and the travel sensor 44 move upward (towards the top of Figure 25) is approximately equal to the height of the step (which is also the amount that the steering wheels 54, 54 move upward (towards the top of Figure 25) as they ride over the step). Therefore, the positional relationship between the travel sensor 44 and the step surface Sd1 is approximately the same as the positional relationship between the travel sensor 44 and the floor surface F when the steering device 10 is traveling on the floor surface F. That is, the sensing surface 44a and the stepped surface Sd1 are approximately parallel, and the distance between the sensing surface 44a of the travel sensor 44 and the stepped surface Sd1 is approximately the same as the value D. The upward direction extending along the axis Ax2 (upward direction in Figure 25) is an example of an implementation configuration corresponding to the "first direction" in the present invention.

[0047] Furthermore, when the steering system 10, which is traveling on a flat floor surface F, travels over a stepped surface Sd2 via a step, as shown in Figure 26, the steering wheels 54, 54 descend the step. At this time, the steering wheel bracket 50 swings in the direction of arrow Rd2 in Figure 26 (clockwise in Figure 26) with the pivot axis 56 as the pivot center. This swing of the steering wheel bracket 50 in the direction of arrow Rd2 with the pivot axis 56 as the pivot center is accompanied by the extension of the coil springs 62, 62. At this time, a force acts on the biasing unit 58 via the coil springs 62, 62 and spring guide rods 60, 60, causing it to swing in the same direction as the steering wheel bracket 50 with the pivot axis 66 as the pivot center. As a result, the biasing unit 58 swings in the clockwise direction in Figure 256. Thus, since the biasing part 58 swings in conjunction with the swing of the steering wheel bracket 50, the swing of the steering wheel bracket 50 accompanied by the extension of the coil springs 62, 62 can be performed smoothly. Furthermore, when the movement of the steering device 10 changes from the stepped surface Sd2 to the floor surface F, the steering wheel bracket 50 swings in the opposite direction to the direction of arrow Rd2 (the direction of arrow Rd1 in Figure 25, and the counterclockwise direction in Figures 25 and 26) with the pivot axis 56 as the pivot center, due to the spring force (restoring force) of the coil springs 62, 62.

[0048] As the steering wheel bracket 50 swings in the direction of arrow Rd2, the axles 54a, 54a move within the elongated holes 41b, 41b in the downward direction extending along the axis Ax2 (downward in Figure 26) and toward the side where the travel sensor 44 is located (leftward in Figure 26). That is, the axles 54a, 54a roll forward (leftward in Figure 26) within the elongated holes 41b, 41b while applying a downward force (downward in Figure 26) to the sensor unit 16 via the elongated holes 41b, 41b. As a result, the sensor unit 16 moves downward (downward in Figure 26). The downward movement of the sensor unit 16 (towards the bottom of Figure 26) is linear, along the direction of extension of the vertically elongated holes 41a, 41a (parallel to the direction of extension of axis Ax2, and also the vertical direction), due to the vertically elongated holes 41a, 41a and the guide supports 47, 47 engaged therewith. As a result, the travel sensor 44 supported by the sensor unit 16 also moves linearly downward (towards the bottom of Figure 26). The distance that the sensor unit 16 and the travel sensor 44 move downward (towards the bottom of Figure 26) is approximately equal to the height of the step (which is also the amount that the steering wheels 54, 54 move downward (towards the bottom of Figure 26) as they descend the step). Therefore, the positional relationship between the travel sensor 44 and the step surface Sd2 is approximately the same as the positional relationship between the travel sensor 44 and the floor surface F when the steering device 10 is traveling on the floor surface F. That is, the sensing surface 44a and the stepped surface Sd2 are approximately parallel, and the distance between the sensing surface 44a of the travel sensor 44 and the stepped surface Sd2 is approximately the same as the value D. The downward direction extending along the axis Ax2 (downward direction in Figure 26) is an example of an implementation configuration corresponding to the "second direction" in the present invention.

[0049] In the automated guided vehicle 1 equipped with the steering device 10 according to the embodiment described above, the steering wheel unit 18 that rotatably supports the steering wheels 54, 54 is pivotably supported via a pivot shaft 56 on the steering frame 12 which is rotatably supported on the vehicle body 2. Therefore, compared to a configuration in which the steering wheel unit 18 is supported on the steering frame 12 so as to be able to move up and down in the direction along the axis Ax2, which is the rotation axis of the steering device 10, this configuration suppresses an increase in the size of the steering device 10 in the height direction (the direction in which the axis Ax2 extends), and allows the steering wheels 54, 54 to follow the unevenness and stepped surfaces Sd1, Sd2 of the floor surface F, even when such unevenness and stepped surfaces Sd1, Sd2 exist on the floor surface F. This prevents vertical vibrations caused by the steering wheels 54, 54 traveling over the unevenness and stepped surfaces Sd1, Sd2 of the floor surface F from being transmitted to the automated guided vehicle 1. As a result, the transport stability of the automated guided vehicle 1 equipped with the steering device 10 can be improved. Furthermore, since the sensor unit 16 is configured to move linearly in the same direction as the movement direction of the steering wheels 54, 54 (parallel to the axis Ax2) as the steering wheel unit 18 swings, changes in the positional relationship between the travel sensor 44 and the floor surface F, specifically the distance D between the travel sensor 44 and the floor surface F and the angle (parallel in this embodiment) between the sensing surface 44a of the travel sensor 44 and the floor surface F can be effectively suppressed. This prevents a decrease in the detection performance of the guide zone Gb (see Figures 1, 4, 24, 25, and 26) by the travel sensor 44, and enables stable travel of the automated guided vehicle 1 along the guide zone Gb.

[0050] Furthermore, in the automated guided vehicle 1 equipped with the steering device 10 according to this embodiment, the biasing part 58 is configured to swing in the same direction as the steering wheel bracket 50 as the steering wheel bracket 50 swings. This allows for smooth expansion and contraction of the coil springs 62, 62 along the spring guide rods 60, 60 as the steering wheel bracket 50 swings. As a result, the spring force can be appropriately applied to the steering wheel bracket 50.

[0051] Furthermore, in the automated guided vehicle 1 equipped with the steering device 10 according to this embodiment, the biasing unit 58 has a configuration in which a pair of spring guide rods 60, 60 and coil springs 62, 62 inserted through the pair of spring guide rods 60, 60, making it easier to secure the desired spring force while suppressing an increase in the size of the biasing unit 58 compared to a configuration with only one coil spring 62.

[0052] Furthermore, according to the automated guided vehicle 1 equipped with the steering device 10 of this embodiment, the oscillating motion of the steering wheel unit 18 can be converted into linear motion in a direction parallel to the axis Ax2 and transmitted to the sensor unit 16 with a simple configuration in which the axles 54a, 54a are engaged with the horizontally elongated holes 41b, 41b and the pair of guide shafts 48, 48 (a pair of rollers 48a, 48a) of the guide supports 47, 47 are engaged with the pair of vertically elongated holes 41a, 41a. This makes it possible to easily ensure a configuration in which the positional relationship between the travel sensor 44 and the floor surface F (such as the distance D between the travel sensor 44 and the floor surface F and the angle of the sensing surface 44a of the travel sensor 44 with respect to the floor surface F) does not change. Furthermore, since the sensor unit 16 has a pair of elongated holes 41a, 41a, and the guide supports 47, 47 that engage with the pair of elongated holes 41a, 41a have a pair of guide shafts 48, 48 (a pair of rollers 48a, 48a), the linear movement of the sensor unit 16 in the direction parallel to the axis Ax2 can be made more stable compared to a configuration in which there is one elongated hole and the guide support that engages with the elongated hole has one guide shaft (one roller). In addition, since the pair of rollers 48a, 48a roll within the pair of elongated holes 41a, 41a, the linear movement of the sensor unit 16 in the direction parallel to the axis Ax2 can be made smooth.

[0053] In this embodiment, the biasing section 58 is configured to have a pair of spring guide rods 60, 60 and coil springs 62, 62 inserted through the pair of spring guide rods 60, 60, but is not limited to this configuration. For example, the biasing section 58 may be configured to have one spring guide rod and a coil spring inserted through that one spring guide rod, or to have three or more spring guide rods and three coil springs inserted through those three or more spring guide rods.

[0054] In this embodiment, a pair of elongated holes 41a, 41a are provided in the plate portions 40, 40, and guide supports 47, 47 having a pair of guide shafts 48, 48 (a pair of rollers 48a, 48a) that engage with the pair of elongated holes 41a, 41a are used, but the embodiment is not limited to this. For example, a configuration in which one elongated hole is provided in the plate portions 40, 40, and a guide support having one guide shaft (one roller) that engages with the one elongated hole is used, or a configuration in which three or more elongated holes are provided in the plate portions 40, 40, and a guide support having three or more guide shafts (one roller) that engage with the three or more elongated holes is used.

[0055] In this embodiment, the rotational motion of the motor 30's rotating shaft (not shown) is transmitted to the rotating body 32 after changing the direction of rotation (rotation with axis Ax1 as the center of rotation) by 90 degrees (changing it to rotation with axis Ax2 as the center of rotation), but the embodiment is not limited to this. For example, the rotational motion of the motor 30's rotating shaft (not shown) may be transmitted to the rotating body 32 without changing the direction of rotation (rotation with axis Ax1 as the center of rotation). That is, the axis Ax1 of the motor 30's rotating shaft (not shown) and the axis Ax2, which is the center of rotation of the rotating body 32, may be arranged on the same axis, or the axis Ax1 of the motor 30's rotating shaft (not shown) and the axis Ax2, which is the center of rotation of the rotating body 32, may be arranged parallel to each other.

[0056] In this embodiment, the steering device 10 is configured such that the steering wheels 54, 54 are steered only by the motor 30, but it is not limited to this configuration. For example, the steering device 10 may have a separate motor in addition to the motor 30 to drive the steering wheels 54, 54, that is, a configuration in which the steering wheels 54, 54 are both steered and driven. In this case, the drive unit 4 can be omitted.

[0057] 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.

[0058] <Note> In view of the spirit of the invention described above, the steering device 10 and the automated guided vehicle 1 equipped therewith according to the present invention can be configured in the following forms. (Aspect 1) A steering device attached to the body of an automated guided vehicle (AGV) for steering the AGV so that it can travel along a guided lane, A steering frame having a first axis and supported by the vehicle body so as to be able to rotate with the first axis as the center of rotation, An actuator mechanically connected to the steering frame so as to be rotatable about the first axis of rotation, A steering wheel having an axle, A first pivot shaft extending parallel to the aforementioned axle, A steering wheel support that rotatably supports the steering wheel via the axle and is pivotably supported on the steering frame via the first pivot shaft, A biasing section having at least one spring, located between the steering frame and the steering wheel support, on the side opposite to the side on which the axle is positioned with respect to the first pivot shaft, A driving sensor capable of detecting the aforementioned guide zone, A sensor support that supports the running sensor on the steering frame in such a manner that the running sensor can move linearly in the first direction as the steering wheel support swings so that the steering wheel moves in the first direction of the extending direction of the first axis, and that the running sensor can move linearly in the second direction as the steering wheel support swings so that the steering wheel moves in the second direction which is opposite to the first direction, A steering system equipped with [a specific feature]. (Aspect 2) The biasing portion comprises a coil spring as the spring, at least one guide rod capable of guiding the expansion and contraction of the coil spring, a second pivot shaft extending parallel to the axle and the first pivot shaft, and a first spring receiving portion to which one end of the coil spring abuts. The steering wheel support has a second spring receiving portion against which the other end of the coil spring abuts. The second spring receiving portion has an insertion hole through which the guide rod can be inserted, The guide rod is supported by the steering frame via the second pivot shaft, with one end of the guide rod inserted into the through hole and the other end of the guide rod engaged with the second pivot shaft. The first spring support is located on the guide rod, near the other end of the guide rod. The steering device described in the above embodiment 1. (Aspect 3) "The guide rod has first and second guide rods arranged parallel to each other, The coil spring has first and second coil springs that are guided by the first and second guide rods, respectively. The first spring support portion includes a third spring support portion located on the first guide rod and near the other end of the first guide rod, and a fourth spring support portion located on the second guide rod and near the other end of the second guide rod. The second spring receiving portion is capable of contacting the other ends of the first and second guide rods. The insertion hole has a first insertion hole through which the first guide rod can be inserted, and a second insertion hole through which the second guide rod can be inserted. The steering device according to the above embodiment. (Aspect 4) "The sensor support has a guide portion that can guide the linear movement of the travel sensor in the first and second directions, The guide portion includes a first elongated hole extending in a direction perpendicular to both the axle and the first axis, at least one second elongated hole extending in the same direction as the extension direction of the first axis, and at least one shaft portion extending parallel to the axle and fixed to the steering frame. The axle is engaged with the first elongated hole, The shaft portion is engaged with the second elongated hole. A steering device according to any one of the above embodiments 1 to 3. (Aspect 5) "The second elongated hole has third and fourth elongated holes arranged parallel to each other, The shaft portion has a first shaft portion that engages with the third elongated hole and a second shaft portion that engages with the fourth elongated hole. The steering device according to the above embodiment 4. (Aspect 6) The shaft portion has a roller that can roll within the second elongated hole. The steering device according to the above embodiment 4 or 5. (Aspect 7) "An automated guided vehicle capable of transporting an object to a predetermined location, The car body and A drive unit having a drive wheel and a motor mechanically connected to the drive wheel, and positioned on the vehicle body, The vehicle body is equipped with at least one auxiliary wheel, A steering device according to any one of the embodiments 1 to 6 fastened to the vehicle body, A control device that controls the drive unit and the steering device, An automated guided vehicle equipped with [a specific feature / equipment]. [Explanation of symbols]

[0059] 1. Automated Guided Vehicle (Automated Guided Vehicle) 2. Vehicle body (vehicle body) 4. Drive Unit (Drive Unit) 4a Drive wheels (drive wheels) 4b Motor (Motor) 4c gearbox 6. Casters (support wheels) 8 Control device (control device) 10. Steering system (steering system) 12. Steering frame (steering frame) 14. Motor Unit (Actuator) 16 Sensor Unit 18 Steering Wheel Unit 20 Part 1 20a Unit support section 20b Flange section 21a Through hole 21b Through hole 21c through hole 22 Part 2 22a Unit support section 22b Flange section 23a Through hole 23b Through hole 23c through hole 24 connecting rods 30 motors 32. Solids of revolution 34 Gearbox 34a Flange section 40 Plate section (sensor support) 40a extension piece 40b Guide piece 41a Elongated hole (guide section, second elongated hole) 41b Horizontal elongated holes (guide section, first elongated hole, third elongated hole, fourth elongated hole) 42 Connection part (sensor support) 42a 1st piece 44. Driving sensor (driving sensor) 47 Guide support 48 Guide shaft (guide section, shaft section, first shaft section, second shaft section) 48a Laura (Laura) 49 Bracket 50 Steering wheel bracket (steering wheel support) 51 Steering wheel support piece 51a Axle insertion hole 51b Swivel shaft insertion hole 52 Connecting piece 52a Through holes (insertion holes, first insertion holes, second insertion holes) 54 Steering wheel (steering wheel) 54a Axle (Axle) 56. Oscillating axis (first oscillating axis) 56a Bearing 58. Enhancing part (enhancing part) 60 Spring Guide Rods (Guide Rod, First Guide Rod, Second Guide Rod) 62. Coil springs (springs, coil springs, first coil springs, second coil springs) 64. Spring support section (first spring support section, third spring support section, fourth spring support section) 66. Oscillating axis (second oscillating axis) 68 connection brackets Ax1 axis line Ax2 axis (1st axis) Sd1 step surface Sd2 step surface D Distance from sensing surface 44a to floor surface F Rd1 Direction of oscillation of steering wheel bracket 50 Rd2 Direction of oscillation of steering wheel bracket 50 Gb guidance zone (guidance zone) F Floor

Claims

1. A steering device attached to the body of an automated guided vehicle (AGV) for steering the AGV so that it can travel along a guided lane, A steering frame having a first axis and supported by the vehicle body so as to be able to rotate with the first axis as the center of rotation, An actuator mechanically connected to the steering frame so as to be rotatable about the first axis of rotation, A steering wheel having an axle, A first pivot shaft extending parallel to the aforementioned axle, A steering wheel support that rotatably supports the steering wheel via the axle and is pivotably supported on the steering frame via the first pivot shaft, A biasing section having at least one spring, located between the steering frame and the steering wheel support, on the side opposite to the side on which the axle is positioned with respect to the first pivot axis, A driving sensor capable of detecting the aforementioned guide zone, A sensor support that supports the running sensor on the steering frame in such a manner that the running sensor is able to move linearly in the first direction as the steering wheel support swings so that the steering wheel moves in the first direction of the extending direction of the first axis, and that the running sensor is able to move linearly in the second direction as the steering wheel support swings so that the steering wheel moves in the second direction which is opposite to the first direction, A steering system equipped with a steering mechanism.

2. The biasing portion includes a coil spring as the spring, at least one guide rod capable of guiding the expansion and contraction of the coil spring, a second pivot shaft extending parallel to the axle and the first pivot shaft, and a first spring receiving portion to which one end of the coil spring abuts. The steering wheel support has a second spring receiving portion against which the other end of the coil spring abuts. The second spring receiving portion has an insertion hole through which the guide rod can be inserted, The guide rod is supported by the steering frame via the second pivot shaft, with one end of the guide rod inserted into the through hole and the other end of the guide rod engaged with the second pivot shaft. The first spring support is located on the guide rod, near the other end of the guide rod. The steering device according to claim 1.

3. The guide rod has first and second guide rods arranged parallel to each other. The coil spring has first and second coil springs that are guided by the first and second guide rods, respectively. The first spring support portion includes a third spring support portion located on the first guide rod and near the other end of the first guide rod, and a fourth spring support portion located on the second guide rod and near the other end of the second guide rod. The second spring receiving portion is capable of contacting the other ends of the first and second coil springs. The insertion hole has a first insertion hole through which the first guide rod can be inserted, and a second insertion hole through which the second guide rod can be inserted. The steering device according to claim 2.

4. The system further includes a guide section capable of guiding the linear movement of the aforementioned travel sensor in the first and second directions. The guide portion includes a first elongated hole disposed in the sensor support so as to extend in a direction perpendicular to both the axle and the first axis, at least one second elongated hole disposed in the sensor support so as to extend in the same direction as the extending direction of the first axis, and at least one shaft portion extending parallel to the axle and fixed to the steering frame. The axle is engaged with the first elongated hole, The shaft portion is engaged with the second elongated hole. The steering device according to any one of claims 1 to 3.

5. The second elongated hole has third and fourth elongated holes arranged parallel to each other. The shaft portion has a first shaft portion that engages with the third elongated hole and a second shaft portion that engages with the fourth elongated hole. The steering device according to claim 4.

6. The shaft portion has rollers that can roll within the second elongated hole. The steering device according to claim 4.

7. An automated guided vehicle capable of transporting an object to a predetermined location, The car body and A drive unit having a drive wheel and a motor mechanically connected to the drive wheel, and positioned on the vehicle body, The vehicle body is equipped with at least one auxiliary wheel, A steering device according to any one of claims 1 to 3, fastened to the vehicle body, A control device that controls the drive unit and the steering device, An automated guided vehicle equipped with the following features.

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