JP7802557B2 - automated guided vehicle - Google Patents

Description

The present invention relates to an automated guided vehicle, and in particular to an automated guided vehicle that can achieve both a low vehicle body floor and a sufficient load capacity.

A two-wheel speed differential type automated guided vehicle is known, which is equipped with a body on which cargo is loaded, left and right drive wheels arranged approximately in the center of the body in the longitudinal direction and configured to be driven independently, and casters arranged on the body and configured to be swivel horizontally (Patent Document 1). Such automated guided vehicles can turn by controlling the rotation speed of the left and right drive wheels, eliminating the need for a steering mechanism. This allows for a simplified structure and a lower floor.

Japanese Patent Application Laid-Open No. 2002-220048 (for example, paragraph 0012, Figures 1 and 2, etc.)

However, the above-mentioned conventional technology has the problem of making it difficult to achieve both a low vehicle floor and a sufficient load capacity. Specifically, in automated guided vehicles that use a two-wheel speed differential system, the weight of the vehicle body and cargo is primarily borne by the drive wheels. Therefore, if the drive wheels are made larger in diameter to ensure a sufficient load capacity, the vehicle height increases. On the other hand, if the drive wheels are made smaller in diameter to achieve a low floor, the load capacity decreases. Furthermore, if the drive wheels are made wider to ensure a sufficient load capacity, frictional resistance with the road surface increases, making turning difficult.

The present invention was made to solve the above-mentioned problems, and aims to provide an automated guided vehicle that can achieve both a low vehicle floor and a sufficient load capacity.

In order to achieve this object, the automated guided vehicle of the present invention comprises a vehicle body on which cargo is loaded, left and right drive wheels arranged approximately in the center of the vehicle body in the fore-and-aft direction and configured to be able to be driven independently, and casters arranged on the vehicle body and configured to be able to swivel horizontally, and further comprises driven wheels that rotate as the vehicle travels, and a swing mechanism interposed between the drive wheels and the driven wheels and the vehicle body and supporting the drive wheels and the driven wheels so that they can swing relative to the vehicle body , the driven wheels being arranged on the left and right, and the swing mechanism comprises left and right supports supporting the drive wheels and the driven wheels, respectively, and left and right swing means arranged between the drive wheels and the driven wheels of the left and right supports and supporting each of the left and right supports so that they can swing relative to the vehicle body, the drive wheels and the driven wheels are arranged side by side in the left-right direction of the vehicle body, and the left and right supports are capable of swinging around an axis oriented along the fore-and-aft direction of the vehicle body .
The automated guided vehicle of the present invention comprises a vehicle body on which a load is carried, left and right drive wheels arranged approximately in the center of the vehicle body in the longitudinal direction and configured to be independently drivable, and casters arranged on the vehicle body and configured to be swivelable in the horizontal direction, and further comprises driven wheels that rotate as the vehicle travels, and a swing mechanism interposed between the drive wheels and the driven wheels and the vehicle body and supporting the drive wheels and the driven wheels so that they can swing relative to the vehicle body, the swing mechanism comprising left and right support bodies and left and right swing shafts that pivotally support the left and right support bodies so that they can swing relative to the vehicle body, one of the left and right support bodies supporting the drive wheels and the driven wheels and also supporting the one support body. The oscillating shaft that supports the body is arranged between the drive wheel and the driven wheel supported by one of the supports, the other of the left and right supports supports the drive wheel on the left-right outer side of the vehicle body than the oscillating shaft that supports the other support, the axles of the drive wheels and the axles of the driven wheels are arranged in a direction along the left-right direction of the vehicle body, the left and right oscillating shafts are arranged in a direction along the fore-and-aft direction of the vehicle body, and the lower surface of a portion of the other support that is more inward in the left-right direction of the vehicle body than the oscillating shaft that supports the other support is connected to the upper surface of a portion of the one support that is more inward in the left-right direction of the vehicle body than the oscillating shaft that supports the one support.

According to the first and sixth aspects of the present invention, the automated guided vehicle is provided with driven wheels that rotate as the vehicle travels, so the weight of the vehicle body and cargo can be distributed between the drive wheels and the driven wheels, and the diameters of the drive wheels and the driven wheels can be made smaller accordingly, thereby achieving both a low vehicle body floor and a sufficient load capacity.

However, when driven wheels are arranged in this manner, uneven road surfaces can make it difficult for the drive or driven wheels to make contact with the ground. However, according to claim 1, a swing mechanism is provided between the drive and driven wheels and the vehicle body, supporting the drive and driven wheels so that they can swing relative to the vehicle body. This makes it easier for both the drive and driven wheels to make contact with the road surface on uneven roads. This prevents the drive wheels from losing wheel load, which can cause the vehicle to become unable to travel, or prevents the drive wheels from failing due to the load being concentrated on the drive wheels.

According to the automatic guided vehicle of claim 1 , since the driven wheels are arranged on the left and right, the number of driven wheels can be secured, and the effect of distributing the weight of the vehicle body and cargo to the drive wheels and driven wheels can be improved. Therefore, the diameters of the drive wheels and driven wheels can be made small, achieving both a low floor of the vehicle body and a sufficient load capacity.

In addition, the drive wheels and driven wheels are supported by left and right supports, respectively, and the left and right supports are supported by left and right swinging means so that they can swing relative to the vehicle body. This makes it easier for the drive wheels and driven wheels on the left and right supports to contact the road surface, respectively, on uneven road surfaces. This prevents the drive wheels from losing wheel load, which makes it impossible to travel, and prevents the drive wheels from breaking down due to the load being concentrated on them.

According to the unmanned guided vehicle of claim 2 , in addition to the effects achieved by the unmanned guided vehicle of claim 1 , the swinging means is configured as left and right swinging shafts arranged between the drive wheels and driven wheels of the left and right supports and supporting each of the left and right supports so that they can swing relative to the vehicle body, thereby stabilizing the swinging of the supports relative to the vehicle body.

According to the unmanned guided vehicle of claim 3 , in addition to the effects achieved by the unmanned guided vehicle of claim 2 , the axles of the driven wheels are arranged in a direction that runs along the left-right direction of the vehicle body, thereby simplifying the structure compared to, for example, a case in which the driven wheels are capable of rotating horizontally relative to the support body.

According to the AGV of claim 4 , in addition to the effects of the AGV of claim 3 , the drive wheels are disposed on the outer side of the vehicle body in the lateral direction relative to the swing shaft, and the driven wheels are disposed on the inner side of the vehicle body in the lateral direction relative to the swing shaft, so that the left and right drive wheels can be spaced apart in the lateral direction of the vehicle body. This improves turning performance. Furthermore, when switching from forward to reverse travel, for example, meandering of the vehicle body due to the rotation of the casters can be suppressed.

According to the automated guided vehicle of claim 5 , in addition to the effects of the automated guided vehicle of claim 4 , the left and right swing shafts are disposed at positions approximately in the center between the drive wheels and driven wheels, so that the loads borne by the drive wheels and the driven wheels can be equalized in each of the left and right swing mechanisms. This makes it possible to configure the drive wheels and driven wheels from the same wheels, thereby reducing parts costs.

According to the automated guided vehicle of claim 6 , the lower surface of a portion of the other support that is laterally inward of the pivotal shaft supporting the other support is connected to the upper surface of a portion of the one support that is laterally inward of the pivotal shaft supporting the one support, thereby enabling interlocking of the one support and the other support. This makes it easier for the left and right drive wheels and driven wheels to contact the road surface on uneven road surfaces. This prevents the drive wheels from losing wheel load, resulting in inability to travel, and prevents load concentration on the drive wheels, resulting in breakdowns. Furthermore, since the number of driven wheels can be reduced to one, component costs can be reduced and the vehicle's laterally dimension can be reduced.

According to the automated guided vehicle of claim 7 , in addition to the effects of the automated guided vehicle of claim 6 , since the drive wheels are disposed on the outer side of the vehicle body in the left-right direction with respect to the swing shaft on one of the supports and the driven wheels are disposed on the inner side of the vehicle body in the left-right direction with respect to the swing shaft, the left and right drive wheels can be spaced apart in the left-right direction of the vehicle body. This improves turning performance. Furthermore, for example, when switching from forward to reverse travel, the vehicle body can be prevented from meandering due to the rotation of the casters.

According to the unmanned guided vehicle of claim 8 , in addition to the effects achieved by the unmanned guided vehicle of claim 7 , the distance between the driven wheels and the oscillating shaft is made larger than the distance between the drive wheels and the oscillating shaft, so that the difference between the load borne by the left and right drive wheels and the load borne by the central driven wheel can be reduced.

1 is a side view of an automated guided vehicle according to a first embodiment of the present invention. FIG. 3 is a cross-sectional view of the automated guided vehicle taken along line III-III in FIG. 1. FIG. 10 is a bottom view of the automatic guided vehicle according to the second embodiment. 5 is a cross-sectional view of the automated guided vehicle taken along line VV in FIG. 4.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Figure 1 is a side view of an automated guided vehicle 1 according to a first embodiment of the present invention, Figure 2 is a bottom view of the automated guided vehicle 1, and Figure 3 is a cross-sectional view of the automated guided vehicle 1 taken along line III-III in Figure 1.

Note that in Figures 1 to 3, the automated guided vehicle 1 is illustrated schematically to simplify the drawings and make them easier to understand. In Figure 3, the spring casters 40 are not shown. Arrows F-B, U-D, and L-R in the figures indicate the front-to-rear direction (travel direction), up-down direction, and left-to-right direction (width direction) of the automated guided vehicle 1, respectively. The same applies to Figures 4 and 5.

As shown in Figures 1 to 3, the automated guided vehicle 1 comprises a vehicle body 10 on which a load is carried, left and right running devices 20 having drive wheels 23, left and right driven bodies 30 having driven wheels 33, spring casters 40 having wheels 44, left and right swing mechanisms 50 interposed between the vehicle body 10 and the running devices 20 and driven bodies 30, and a control device (not shown) that controls the drive motors 24 of the running devices 20. By controlling the rotation speed of the left and right drive wheels 23, the automated guided vehicle 1 is configured to be able to move forward, backward, and turn.

The traveling device 20 includes a seat 21 disposed on the bottom surface of the swing mechanism 50 (support body 51), a pair of forks 22 disposed on the seat 21 and facing each other at a predetermined distance, a drive wheel 23 rotatably supported between the pair of forks 22, and a drive motor 24 that applies a rotational drive force to the drive wheel 23.

The driven body 30 comprises a seat 31 disposed on the bottom surface of the swing mechanism 50 (support body 51), a pair of forks 32 disposed on the seat 31 and facing each other at a predetermined distance, and a driven wheel 33 rotatably supported between the pair of forks 32; the driven wheel 33 rotates (is driven) as the vehicle travels. In this embodiment, the driven body 30 (seat 31 and forks 32) is fixed to the vehicle body 10 via the swing mechanism 50, which simplifies the structure compared to, for example, when the driven body 30 is rotatable horizontally relative to the vehicle body 10.

The spring caster 40 comprises a seat 41 disposed on the underside of the vehicle body 10, a housing 42 configured to be swivelable horizontally relative to the seat 41, a pair of forks 43 rotatably supported at one end by the housing 42 and facing each other at a specified distance, a wheel 44 rotatably supported between the other ends of the pair of forks 43, and a spring 45 interposed between the housing 42 and the fork 43. The spring caster 40 is configured as a swivel caster in which the axle of the wheel 44 is positioned away (eccentrically) from the center of rotation of the housing 42.

The spring caster 40 allows the distance between the vehicle body 10 and the wheel 44 to be changed by the elastic deformation (expansion and contraction) of the spring 45. This makes it easier for the drive wheel 23 to contact the ground even if the road surface G is undulating in the fore-and-aft direction of the vehicle body 10 (in the direction of arrows F-B) (when the road surface G shown in Figure 1 forms hills and valleys).

The swing mechanism 50 comprises a support 51, with the seat 21 of the traveling unit 20 at one end (in this embodiment, on the outside of the width of the vehicle body 10) in the left-right direction (arrow L-R direction) and the seat 31 of the driven unit 30 at the other end (in this embodiment, on the inside of the width of the vehicle body 10) in the left-right direction (arrow L-R direction); a swing shaft 52 located approximately in the center of the support 51 in the left-right direction (arrow L-R direction); and a stay 53 swingably supporting the swing shaft 52 and located on the underside of the vehicle body 10, facing and spaced apart in the fore-aft direction of the vehicle body 10 (arrow F-B direction), and is configured to swing relative to the vehicle body 10.

A pair of rocking mechanisms 50 are arranged side by side in the left-right direction (arrow L-R direction) of the vehicle body 10, and the pair of rocking mechanisms 50 (left and right) are disposed in a position that is approximately in the center of the fore-aft direction (arrow F-B direction) of the vehicle body 10. In addition, the pair of rocking mechanisms 50 (left and right) are disposed in positions that are symmetrical with respect to an imaginary line connecting the rotation centers of the front and rear spring casters 40 in a plan view (see Figure 2).

The swing shaft 52 of the swing mechanism 50 is arranged to extend in the longitudinal direction of the vehicle body 10 (in the direction of the arrows F-B), and the axles of the drive wheels 23 and the driven wheels 33 are arranged to extend in the lateral direction of the vehicle body 10 (in the direction of the arrows L-R). The drive wheels 23 and the driven wheels 33 are arranged so that their axles are aligned in a straight line in a plan view (see Figure 2).

The automated guided vehicle 1 in this embodiment is equipped with driven wheels 33, which allows the weight of the vehicle body 10 and cargo to be distributed between the drive wheels 23 and driven wheels 33, allowing the diameter of the drive wheels 23 and driven wheels 33 to be reduced without increasing their width. This allows for a low floor for the vehicle body 10 while still ensuring sufficient load capacity.

Here, if the drive wheels 23 and driven wheels 33 (more specifically, the running device 20 and driven body 30) are arranged directly on the vehicle body 10, and the road surface G is undulating in the left-right direction (arrow L-R direction) of the vehicle body 10 (the road surface G shown in Figure 3 forms mountains and valleys), it will be difficult for the drive wheels 23 or driven wheels 33 to make contact with the ground.

In contrast, with the automated guided vehicle 1 of this embodiment, a swing mechanism 50 is interposed between the vehicle body 10 and the drive wheels 23 and driven wheels 33, and the drive wheels 23 and driven wheels 33 are supported so that they can swing relative to the vehicle body 10. Therefore, even on a road surface G that is uneven in the left-right direction of the vehicle body 10, the swing of the swing mechanism 50 (support body 51) makes it easier to ensure that both the drive wheels 23 and driven wheels 33 are in contact with the road surface G. This prevents the drive wheels 23 from losing wheel load, which can cause the vehicle to become unable to travel, and prevents the load from concentrating on the drive wheels 23, which can damage or break the drive wheels 23 or drive motor 24.

In this embodiment, in each of the left and right swing mechanisms 50, the drive wheels 23 are disposed on the outside of the swing shaft 52 in the left-right direction of the vehicle body 10 (in the direction of the arrows L-R), and the driven wheels 33 are disposed on the inside of the swing shaft 52 in the left-right direction of the vehicle body 10. This ensures (increases) the distance between the left and right drive wheels 23 in the left-right direction of the vehicle body 10. This improves turning performance. Furthermore, for example, when switching from forward to reverse travel, the vehicle body 10 can be prevented from meandering as the spring casters 40 turn.

In this embodiment, the swing shaft 52 is disposed in a position that is approximately centered between the axles of the drive wheels 23 and the driven wheels 33 in a plan view (a position where the distance in the left-right direction (arrows L-R) of the vehicle body 10 is approximately the same) (see Figure 2). This allows the load borne by the drive wheels 23 and the driven wheels 33 to be equalized in each of the left and right swing mechanisms 50. This allows the drive wheels 23 and the driven wheels 33 to be constructed from the same wheel (rubber tire in this embodiment), thereby reducing parts costs.

Next, an automated guided vehicle 201 in a second embodiment will be described with reference to Figures 4 and 5. The automated guided vehicle 1 in the first embodiment has two driven wheels 33, but the automated guided vehicle 201 in the second embodiment has one driven wheel 33.

Figure 4 is a bottom view of the automated guided vehicle 201 in the second embodiment, and Figure 5 is a cross-sectional view of the automated guided vehicle 201 taken along line V-V in Figure 4. Note that parts that are the same as those in the first embodiment described above are given the same reference numerals, and their description will be omitted.

As shown in Figures 4 and 5, the automated guided vehicle 201 includes a vehicle body 10, left and right running devices 20, one follower 30, spring casters 40, left and right swing mechanisms 250A, 250B interposed between the running devices 20 and the vehicle body 10, and the follower 30, and a control device (not shown) that controls the running devices 20 (drive motor 24).

The swing mechanism 250A includes a first support 251a, with the seat 21 of the traveling device 20 located at one end (in this embodiment, on the outside of the vehicle body 10 in the width direction) in the left-right direction (arrow L-R direction), and the seat 31 of the driven body 30 located at the other end (in this embodiment, on the inside of the vehicle body 10 in the width direction) in the left-right direction (arrow L-R direction). The swing shaft 52 located on the first support 251a is journaled by a stay 53, allowing the mechanism to swing relative to the vehicle body 10.

The swing mechanism 250B includes a second support 251b on which the seat 21 of the traveling device 20 is arranged at one end (outside the width of the vehicle body 10 in this embodiment) in the left-right direction (in the direction of the arrows L-R). The swing shaft 52 arranged on the second support 251b is supported by a stay 53, allowing the seat 21 to swing relative to the vehicle body 10.

The rocking mechanisms 250A, 250B are arranged side by side in the left-right direction (arrow L-R direction) of the vehicle body 10, and are disposed at a position that is approximately central in the fore-aft direction (arrow F-B direction) of the vehicle body 10.

As in the first embodiment, the swing shaft 52 is arranged to extend in the longitudinal direction of the vehicle body 10 (in the direction of the arrows F-B), and the axles of the drive wheels 23 and the driven wheels 33 are arranged to extend in the lateral direction of the vehicle body 10 (in the direction of the arrows L-R). The drive wheels 23 and the driven wheels 33 are arranged so that their axles are aligned in a straight line in a plan view (see Figure 4).

In a plan view, the driven wheels 33 are positioned so that their tire center lines coincide with an imaginary line connecting the swivel centers of the front and rear spring casters 40, and the drive wheels 23 and oscillating shafts 52 are positioned so as to be symmetrical with respect to the imaginary line connecting the swivel centers of the front and rear spring casters 40 (see Figure 4).

The first support 251a and the second support 251b overlap each other in the vertical direction (in the direction of the arrows U-D) at their portions that are on the inside in the left-right direction (in the direction of the arrows L-R) of the vehicle body 10. In other words, the lower surface of the portion of the second support 251b that is on the inside in the left-right direction of the vehicle body 10 (left side in Figure 5) of the swing shaft 52 is slidably connected to the upper surface of the portion of the first support 251a that is on the inside in the left-right direction of the vehicle body 10 (right side in Figure 5) of the swing shaft 52. When either the first support 251a or the second support 251b swings, the other can also swing in conjunction with the swing of the other.

A protrusion protrudes from the underside of the other end (in the width direction of the vehicle body 10 in this embodiment) of the second support body 251b in the left-right direction (arrow L-R direction), and the tip of the protrusion rests on the upper surface of the first support body 251a, connecting the first support body 251a and the second support body 251b. This reduces resistance when the protrusion of the second support body 251b slides on the upper surface of the first support body 251a in the left-right direction of the vehicle body 10 (arrow L-R direction).

In the automated guided vehicle 201 of this embodiment, as in the first embodiment described above, the weight of the vehicle body 10 and cargo can be distributed between the drive wheels 23 and the drive wheels 33, and the diameters of the drive wheels 23 and the drive wheels 33 can be reduced accordingly by providing the drive wheels 23 and the drive wheels 33. This allows for both a low floor for the vehicle body 10 and a sufficient load capacity.

Furthermore, even if the road surface G is undulating in the left-right direction (in the direction of the arrows L-R) of the vehicle body 10 (the road surface G shown in Figure 5 has hills and valleys), the swinging of the swinging mechanisms 250A, 250B (first support 251a and second support 251b) makes it easier to ensure that the left and right drive wheels 23 and the central driven wheel 33 are in contact with the road surface G. This prevents the drive wheels 23 from losing wheel load, making the vehicle unable to travel, and prevents the load from concentrating on the drive wheels 23, causing damage or failure to the drive wheels 23 or drive motor 24.

In particular, with the automated guided vehicle 201 of this embodiment, the number of driven wheels 33 can be reduced to one, thereby reducing component costs and minimizing the dimension of the vehicle body 10 in the left-right direction (in the direction of the arrows L-R).

In this embodiment, in the swing mechanism 250A, the drive wheels 23 are disposed on the outside of the swing shaft 52 in the left-right direction of the vehicle body 10 (in the direction of the arrows L-R), and the driven wheels 33 are disposed on the inside of the swing shaft 52 in the left-right direction of the vehicle body 10. This ensures (increases) the distance between the left and right drive wheels 23 in the left-right direction of the vehicle body 10. This improves turning performance. Furthermore, for example, when switching the traveling direction from forward to reverse, the vehicle body 10 can be prevented from meandering as the spring casters 40 turn.

In this embodiment, the position at which the protrusion of the second support 251b is placed on the upper surface of the first support 251a overlaps with the tire centerline of the driven wheel 33 (see Figure 5). Furthermore, in a plan view, the axle of the driven wheel 33 is disposed in a position that is approximately centered between the left and right oscillating shafts 52 (a position where the distance in the left-right direction (arrow L-R direction) of the vehicle body 10 is approximately the same), and the distance between the axle of the drive wheel 23 and the oscillating shaft 52 is approximately the same for the left and right drive wheels 23, and the distance between the axle of the driven wheel 33 and the oscillating shaft 52 is set to approximately twice the distance between the axle of the drive wheel 23 and the oscillating shaft 52 (see Figure 4).

This allows the load borne by the left and right drive wheels 23 to be equalized with the load borne by the central driven wheel 33. Therefore, the drive wheels 23 and driven wheels 33 can be constructed from the same wheel (rubber tire in this embodiment), thereby reducing parts costs.

The present invention has been described above based on an embodiment, but the present invention is in no way limited to the above embodiment, and it is readily apparent that various improvements and modifications are possible within the scope of the present invention.

The numerical values given in the above embodiment are merely examples, and it is of course possible to adopt other numerical values. For example, in the above second embodiment, the distance between the axle of the driven wheel 33 and the oscillating shaft 52 is described as being set to approximately twice the distance between the axle of the drive wheel 23 and the oscillating shaft 52, but it may be set to a value less than or greater than twice the distance.

In the first embodiment described above, the pivot shaft 52 is disposed in a position that is approximately centered between the axles of the drive wheels 23 and the driven wheels 33 in a plan view. However, the position of the pivot shaft 52 may be changed from the approximately center position. This allows the distribution of the load borne by the drive wheels 23 and the driven wheels 33 to be changed.

In this case, the wheel (e.g., driven wheel 33) on the side where the distance to the oscillating shaft 52 is greater will bear a smaller load, so it may have a smaller outer diameter than the wheel (drive wheel 23) on the side where the distance to the oscillating shaft 52 is smaller.

In the second embodiment described above, the swing mechanism 250B may be omitted. That is, one of the left and right drive wheels 23 (traveling device 20) may be directly mounted on the vehicle body 10, and the other drive wheel 23 (traveling device 20) may be mounted on the swing mechanism 250A together with one driven wheel 33 (follower 30).

In the above embodiments, the drive wheels 23 are disposed on the outside of the driven wheels 33 in the left-right direction of the vehicle body 10 (in the direction of the arrows L-R), but the reverse arrangement (the drive wheels 23 are disposed on the inside of the driven wheels 33 in the left-right direction of the vehicle body 10) may also be used.

In the above embodiments, the oscillating shaft 52 is disposed on the support 51 and is pivotally supported by the stay 53 so that it can oscillate. However, the oscillating shaft 52 may also be disposed on the stay 53 and be pivotally supported by the support 51 so that it can oscillate.

In each of the above embodiments, a damping mechanism that applies a damping force to the oscillating mechanism 50, 250A, 250B may be added. Examples of the damping mechanism include a shock absorber interposed between the vehicle body 10 and the support 51, first support 251a, and second support 251b, and a rotary damper interposed between the oscillating shaft 52 and the stay 53. This can improve the running stability of the automated guided vehicle 1, 201.

An elastic body (e.g., a cylindrical rubber bushing) made of a rubber-like elastic material may be interposed between the outer peripheral surface of the oscillating shaft 52 and the inner peripheral surface of the stay 53. Deformation of the elastic body (rubber bushing) allows the support body 51, first support body 251a, and second support body 251b to oscillate relative to the vehicle body 10, while also providing a damping mechanism.

Furthermore, the pivot shaft 52 may be omitted and an elastic body (oscillating means) may be interposed between the underside of the vehicle body 10 and the upper surfaces of the support body 51, the first support body 251a, and the second support body 251b. Alternatively, the pivot shaft 52 may be omitted and an elastic body (oscillating means) may be interposed between the support body 51, the first support body 251a, and the second support body 251b and the stay 53. In these cases, too, a damping mechanism can be added while deformation of the elastic body allows the support body 51, the first support body 251a, and the second support body 251b to oscillate relative to the vehicle body 10.

In the above embodiments, the driven wheels 33 (follower 30) are arranged on the support body 51 or the first support body 251a so as not to be able to swivel (the seat 31 is fixed to the support body 51 or the first support body 251a), but the driven wheels 33 (follower 30) may also be arranged on the support body 51 or the first support body 251a so as to be able to swivel horizontally. In other words, the driven wheels 33 (follower 30) may be configured as swivel casters. In this case, resistance when the vehicle is turning can be reduced.

In the first embodiment described above, the swing shaft 52 is arranged in a direction along the fore-and-aft direction of the vehicle body 10 (direction of arrows F-B), and the drive wheels 23 and driven wheels 33 are arranged on the support body 51 with the swing shaft 52 sandwiched between them in the left-and-right direction of the vehicle body 10 (direction of arrows L-R). However, a configuration in which the swing shaft 52 is arranged in a direction along the left-and-right direction of the vehicle body 10 (direction of arrows L-R) (i.e., parallel to the axle of the drive wheels 23), and the drive wheels 23 and casters are arranged on the support body 51 with the swing shaft 52 sandwiched between them in the fore-and-aft direction of the vehicle body 10 (direction of arrows F-B) may also be used.

In this case, the drive wheel 23 is positioned approximately in the center of the fore-and-aft direction of the vehicle body 10 (in the direction of arrows F-B) in a plan view, and the caster disposed on the support body 51 is positioned on one side of the vehicle body 10 in the fore-and-aft direction. The caster disposed on the vehicle body 10 is disposed on the other side of the vehicle body 10 in the fore-and-aft direction in a plan view. These casters do not need to be spring casters 40, as long as they are swivel casters that can swivel horizontally. Furthermore, only one caster wheel is required to be disposed on the vehicle body 10.

With an automated guided vehicle configured in this manner, three-point support is provided, making it easier for the drive wheels 23 to contact the ground even when the road surface G is uneven in the fore-and-aft direction (direction of arrows F-B) of the vehicle body 10 (when the road surface G shown in Figure 1 has hills and valleys). The distance between the axle of the caster mounted on the support body 51 and the swing shaft 52 is greater than the distance between the axle of the drive wheels 23 and the swing shaft 52 in a plan view.

1,201 Automatic guided vehicle 10 Vehicle body 23 Driving wheel 33 Driven wheel 40 Spring caster (caster)
50 Swing mechanism 51 Support 52 Swing shafts 250A, 250B Swing mechanism 251a First support (one of the supports)
251b Second support (other support)
Arrows FB: forward/backward direction Arrows UD: up/down direction Arrows LR: left/right direction

Claims (8)

An automated guided vehicle (AGV) is provided with a vehicle body on which a load is carried, left and right drive wheels arranged approximately in the center of the vehicle body in the longitudinal direction and configured to be independently drivable, and casters arranged on the vehicle body and configured to be rotatable in a horizontal direction,
a driven wheel that rotates as the vehicle travels; and a swing mechanism that is interposed between the drive wheel and the driven wheel and the vehicle body and that supports the drive wheel and the driven wheel so that they can swing relative to the vehicle body ;
The driven wheels are disposed on the left and right sides,
the swing mechanism includes left and right supports that support the drive wheels and the driven wheels, respectively, and left and right swing means that are disposed between the drive wheels and the driven wheels of the left and right supports and support the left and right supports so that they can swing relative to the vehicle body,
The drive wheels and the driven wheels are arranged side by side in the left-right direction of the vehicle body,
The left and right supports are capable of swinging about axes oriented along the longitudinal direction of the vehicle body . the swinging means are configured as left and right swinging shafts that are disposed between the drive wheels and the driven wheels of the left and right supports and pivotally support the left and right supports so that they can swing relative to the vehicle body,
The axles of the drive wheels are arranged in a direction along the left-right direction of the vehicle body,
2. The automated guided vehicle according to claim 1 , wherein the left and right swing shafts are disposed in a direction parallel to the longitudinal direction of the vehicle body. 3. The automated guided vehicle according to claim 2 , wherein the axles of the driven wheels are disposed in a direction parallel to the left-right direction of the vehicle body. 4. The automated guided vehicle according to claim 3 , wherein the drive wheels are disposed on the outer side of the vehicle body in the left-right direction relative to the swing shaft, and the driven wheels are disposed on the inner side of the vehicle body in the left-right direction relative to the swing shaft. 5. The automated guided vehicle according to claim 4 , wherein the swing shaft is disposed at a position substantially in the center between the driving wheels and the driven wheels. An automated guided vehicle (AGV) is provided with a vehicle body on which a load is carried, left and right drive wheels arranged approximately in the center of the vehicle body in the longitudinal direction and configured to be independently drivable, and casters arranged on the vehicle body and configured to be rotatable in a horizontal direction,
a driven wheel that rotates as the vehicle travels; and a swing mechanism that is interposed between the drive wheel and the driven wheel and the vehicle body and that supports the drive wheel and the driven wheel so that they can swing relative to the vehicle body ;
the swing mechanism includes left and right support bodies and left and right swing shafts that pivotally support the left and right support bodies so that they can swing relative to the vehicle body,
one of the left and right supports supports the drive wheel and the driven wheel, and the swing shaft supporting the one support is disposed between the drive wheel and the driven wheel supported by the one support,
the other of the left and right supports supports the drive wheel on the outer side in the left-right direction of the vehicle body than the swing shaft that pivotally supports the other support,
the axles of the drive wheels and the axles of the driven wheels are disposed along the left-right direction of the vehicle body,
The left and right swing shafts are disposed in a direction along the front-rear direction of the vehicle body,
an underside of a portion of the other support body that is located laterally inward of the vehicle body relative to the oscillating shaft that supports the other support body, connected to an upper surface of a portion of the one support body that is located laterally inward of the oscillating shaft that supports the one support body . 7. The automated guided vehicle according to claim 6, wherein, on one of the supports, the drive wheels are arranged on the outer side of the vehicle body in the left-right direction relative to the swing shaft, and the driven wheels are arranged on the inner side of the vehicle body in the left- right direction relative to the swing shaft. 8. The automated guided vehicle according to claim 7 , wherein the distance between the driven wheels and the swing shaft is greater than the distance between the drive wheels and the swing shaft.