Transport vehicle

Abstract

The present invention provides a transport vehicle that is easily miniaturized in a configuration equipped with a rotation detection device. [Solution] The forks are positioned to protrude from the lifting device toward the rear, and the vehicle body comprises a main body that supports the travel drive unit 5, and a pair of legs positioned on both sides in the width direction relative to the lifting trajectory of the forks, so as to protrude from the main body toward the rear, and the drive wheel 41 and the rotation detection device 6 that detects the rotation of the drive wheel 41 are supported by the travel drive unit 5, and the rotation detection device 6 comprises a driven roller 61 positioned so as to be in contact with the outer circumferential surface of the drive wheel 41 and rotating in conjunction with the rotation of the drive wheel 41, and a rotation sensor that detects the rotation of the driven roller 61, and the rotation axis A2 of the driven roller 61 is above the rotation axis A1 of the drive wheel 41 and is positioned in a different direction T from the rotation axis A1 of the drive wheel 41.

Description

Technical Field

[0001] The present invention relates to a carrier vehicle.

Background Art

[0002] Patent Document 1 below discloses a carrier vehicle (1) including a drive wheel (7), a traveling drive device (6) for driving the drive wheel (7), and a rotation detection device for detecting the rotation of the drive wheel (7). In addition, the reference numerals shown in parentheses in the description of the background art are those of Patent Document 1.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the carrier vehicle (1) of Patent Document 1, the rotation detection device includes a first gear (8) that rotates integrally with the drive wheel (7), a second gear (9) that meshes with the first gear (8), a third gear (10) that has an outer diameter different from that of the first gear (8) and meshes with the second gear (9), and a rotation sensor (19) that detects the rotation of the third gear (10).

[0005] Therefore, it is necessary to secure a relatively large space for the arrangement of the above rotation detection device, which has led to an increase in the size of the carrier vehicle (1).

[0006] Therefore, in a configuration including a rotation detection device, it is desired to realize a carrier vehicle that is easy to miniaturize.

Means for Solving the Problems

[0007] In view of the above, the characteristic configuration of the carrier vehicle is forks for supporting a pallet, A lifting device for raising and lowering the fork, Multiple wheels, including the drive wheels, A drive system that drives the aforementioned drive wheels, A transport vehicle comprising the lifting device, a plurality of wheels, and a vehicle body supporting the drive system, A specific direction along the horizontal plane is defined as the front-rear direction, one side of the front-rear direction is defined as the front, the other side of the front-rear direction is defined as the rear, a direction along the horizontal plane that is perpendicular to the front-rear direction is defined as the width direction, a direction along the rotation axis of the drive wheel is defined as the axial direction, and a direction perpendicular to the axial direction when viewed from above is defined as the travel direction. The fork is positioned to protrude from the lifting device toward the rear. The vehicle body comprises a main body that supports the drive unit, and a pair of legs arranged on both sides in the width direction with respect to the lifting trajectory of the fork, so as to protrude from the main body toward the rear. The device further includes a rotation detection device for detecting the rotation of the drive wheel, The drive wheel and the rotation detection device are supported by the drive unit. The rotation detection device comprises a driven roller positioned so as to contact the outer circumferential surface of the drive wheel and rotating in conjunction with the rotation of the drive wheel, and a rotation sensor for detecting the rotation of the driven roller. The rotation axis of the driven roller is located above the rotation axis of the drive wheel and is positioned in a different direction from the rotation axis of the drive wheel in the direction of travel. 、 The main body includes a pivot support portion that pivotably supports the travel drive device around a pivot axis along the vertical direction, The rotation detection device is positioned below the downward-facing bottom surface of the pivot support and above the rotation axis of the drive wheel. The aforementioned drive system includes the drive source which is the drive source for the drive wheels, The rotation detection device and the drive source are positioned inward from the outer edge of the turning trajectory of the drive wheel when the drive unit turns around the turning axis, as viewed from above. It's at a single point.

[0008] This configuration allows the driven rollers of the rotation detection device to be positioned in the space formed diagonally above the drive wheels. This makes it easier to suppress the increase in size of the transport vehicle that would otherwise be required to accommodate the rotation detection device. In other words, it is easier to miniaturize the transport vehicle in a configuration that includes a rotation detection device. Furthermore, this feature configuration allows for the placement of a rotation detection device in a space formed below the bottom surface of the swivel support section, where it does not interfere with the drive wheels and the travel drive system. Therefore, it is easier to further miniaturize the transport vehicle. Furthermore, this feature configuration makes it easier to miniaturize the transport vehicle in the direction perpendicular to the pivot axis of the drive wheels.

[0009] In light of the above, another characteristic configuration of the transport vehicle is: Forks to support the pallet, A lifting device for raising and lowering the fork, Multiple wheels, including the drive wheels, A drive system that drives the aforementioned drive wheels, A transport vehicle comprising the lifting device, a plurality of wheels, and a vehicle body supporting the drive system, A specific direction along the horizontal plane is defined as the front-rear direction, one side of the front-rear direction is defined as the front, the other side of the front-rear direction is defined as the rear, a direction along the horizontal plane that is perpendicular to the front-rear direction is defined as the width direction, a direction along the rotation axis of the drive wheel is defined as the axial direction, and a direction perpendicular to the axial direction when viewed from above is defined as the travel direction. The fork is positioned to protrude from the lifting device toward the rear. The vehicle body comprises a main body that supports the drive unit, and a pair of legs arranged on both sides in the width direction with respect to the lifting trajectory of the fork, so as to protrude from the main body toward the rear. The device further includes a rotation detection device for detecting the rotation of the drive wheel, The drive wheel and the rotation detection device are supported by the drive unit. The rotation detection device comprises a driven roller positioned so as to contact the outer circumferential surface of the drive wheel and rotating in conjunction with the rotation of the drive wheel, and a rotation sensor for detecting the rotation of the driven roller. The rotation axis of the driven roller is located above the rotation axis of the drive wheel and is positioned in a different direction from the rotation axis of the drive wheel in the direction of travel. The main body includes a pivot support portion that pivotably supports the travel drive device around a pivot axis along the vertical direction, The system further comprises a detection unit supported to rotate integrally with the travel drive unit around the pivot axis, and a pivot position sensor that detects whether the pivot angle of the travel drive unit in the width direction is within a set angle range including 90°, with the detection unit as the detection target, The distinguishing feature of the detected unit is that, when the drive unit rotates around the pivot axis, the outer edge of the pivot trajectory of the detected unit is positioned so that, in a vertical view, it is positioned outside the outer edge of the pivot trajectory of the drive wheel.

[0010] This configuration allows the driven rollers of the rotation detection device to be positioned in the space formed diagonally above the drive wheels. This makes it easier to suppress the increase in size of the transport vehicle that would otherwise be required to accommodate the rotation detection device. In other words, it is easier to miniaturize the transport vehicle in a configuration that includes a rotation detection device. Furthermore, this feature configuration allows for the detection, with a simple setup, of whether the drive wheels are being driven for straight-line movement of the transport vehicle or for changing the direction of the transport vehicle.

[0011] In light of the above, another characteristic configuration of the transport vehicle is: Forks to support the pallet, A lifting device for raising and lowering the fork, Multiple wheels, including the drive wheels, A drive system that drives the aforementioned drive wheels, A transport vehicle comprising the lifting device, a plurality of wheels, and a vehicle body supporting the drive system, A specific direction along the horizontal plane is defined as the front-rear direction, one side of the front-rear direction is defined as the front, the other side of the front-rear direction is defined as the rear, a direction along the horizontal plane that is perpendicular to the front-rear direction is defined as the width direction, a direction along the rotation axis of the drive wheel is defined as the axial direction, and a direction perpendicular to the axial direction when viewed from above is defined as the travel direction. The fork is positioned to protrude from the lifting device toward the rear. The vehicle body comprises a main body that supports the drive unit, and a pair of legs arranged on both sides in the width direction with respect to the lifting trajectory of the fork, so as to protrude from the main body toward the rear. The device further includes a rotation detection device for detecting the rotation of the drive wheel, The drive wheel and the rotation detection device are supported by the drive unit. The rotation detection device comprises a driven roller positioned so as to contact the outer circumferential surface of the drive wheel and rotating in conjunction with the rotation of the drive wheel, and a rotation sensor for detecting the rotation of the driven roller. The rotation axis of the driven roller is located above the rotation axis of the drive wheel and is positioned in a different direction from the rotation axis of the drive wheel in the direction of travel. The plurality of wheels include a pair of drive wheels arranged on the same axle, Each of the pair of drive wheels is fitted with the driven roller, The pair of driven rollers are positioned on either side of the rotation axis of the pair of drive wheels in the direction of travel.

[0012] This configuration allows the driven rollers of the rotation detection device to be positioned in the space formed diagonally above the drive wheels. This makes it easier to suppress the increase in size of the transport vehicle that would otherwise be required to accommodate the rotation detection device. In other words, it is easier to miniaturize the transport vehicle in a configuration that includes a rotation detection device. Furthermore, this feature configuration allows the pair of rotation detection devices to have similar configurations, rather than being arranged symmetrically in the axial direction. Therefore, it is possible to standardize parts between the pair of rotation detection devices, which in turn can reduce the cost of the transport vehicle. [Brief explanation of the drawing]

[0013] [Figure 1] Perspective view of the transport vehicle according to the embodiment [Figure 2] Bottom view of the transport vehicle according to the embodiment [Figure 3] Plan and cross-sectional view of a transport vehicle according to an embodiment. [Figure 4] Plan and cross-sectional view showing the configuration of the travel drive system and rotation detection system. [Figure 5] Side view showing the configuration of the travel drive system and rotation detection system. [Modes for carrying out the invention]

[0014] In the following description, the transport vehicle 100 according to the embodiment will be explained with reference to the drawings.

[0015] As shown in Figures 1 and 2, the transport vehicle 100 comprises a fork 1, a lifting device 2, a vehicle body 3, a plurality of wheels 4, and a driving device 5.

[0016] In the following description, a specific direction along the horizontal plane will be referred to as the "front-rear direction D". One side of the front-rear direction D will be referred to as the "front side D1", and the other side of the front-rear direction D will be referred to as the "rear side D2". Furthermore, a direction along the horizontal plane that is perpendicular to the front-rear direction D will be referred to as the "width direction W". In this application, the "vertical direction" refers to the vertical direction when the transport vehicle 100 is positioned on a horizontal plane.

[0017] The fork 1 is configured to support the pallet P. The fork 1 is positioned to protrude from the lifting device 2 toward the rear D2. In this embodiment, a pair of forks 1 are arranged side by side with a gap between them in the width direction W. As the pallet P, various existing pallets commonly used in the logistics industry can be used.

[0018] As shown in Figures 1 and 3, the lifting device 2 is a device for raising and lowering the fork 1. In this embodiment, the lifting device 2 comprises a pair of lifting rails 21, a pair of lifting rollers 22, a pair of roller support members 23, a fork connecting member 24, a lifting member 25, a lifting drive device 26, and a pair of chains 27.

[0019] Each of the pair of lifting rails 21 is formed to extend along the vertical direction. The pair of lifting rails 21 are arranged side by side with a gap between them in the width direction W.

[0020] Each of the pair of lifting rollers 22 is configured to roll along the lifting rail 21. In this embodiment, each of the pair of lifting rollers 22 is configured to rotate freely around a rotation axis along the width direction W. Each of the pair of lifting rollers 22 is arranged to roll on a pair of rolling surfaces on the lifting rail 21 that face each other in the front-rear direction D.

[0021] Each of the pair of roller support members 23 is a member that rotatably supports the lifting roller 22. In this embodiment, each of the pair of roller support members 23 is formed in a plate shape perpendicular to the width direction W.

[0022] The fork connecting member 24 is the member to which the forks 1 are connected. A pair of roller support members 23 are fixed to the fork connecting member 24. In this embodiment, the fork connecting member 24 is formed in a plate shape perpendicular to the front-rear direction D.

[0023] The lifting member 25 is a member that is raised and lowered by a lifting drive device 26 via a pair of chains 27. The lifting member 25 is connected to a fork connecting member 24. Therefore, as the lifting member 25 moves up and down, the fork 1 moves up and down via the fork connecting member 24. In this embodiment, the lifting member 25 is formed in the shape of a plate perpendicular to the vertical direction.

[0024] As shown in Figure 1, the lifting drive device 26 is a device that raises and lowers a lifting member 25 via a pair of chains 27. In this embodiment, the lifting drive device 26 comprises a pair of sprockets (not shown) around which the pair of chains 27 are wound, and a lifting drive source (not shown) that rotates the pair of sprockets.

[0025] In this embodiment, one end of a pair of chains 27 is connected to a lifting member 25. Although not shown in the figures, the other end of the pair of chains 27 is connected to a pair of forks 1, a pair of lifting rollers 22, a pair of roller support members 23, a fork connecting member 24, and a counterweight that balances the lifting member 25.

[0026] As shown in Figure 3, the vehicle body 3 is configured to support the lifting device 2, a plurality of wheels 4, and the driving device 5. The vehicle body 3 comprises a main body 31 and a pair of legs 32.

[0027] The main body 31 is configured to support the travel drive unit 5. In this embodiment, the main body 31 includes a swivel support section 311 and a pair of rail support sections 312.

[0028] The swivel support section 311 is configured to support the travel drive unit 5 so that it can rotatably support it around a swivel axis C1 that is aligned in the vertical direction. In this embodiment, the swivel support section 311 comprises a fixed section 313 and a swivel section 314.

[0029] The swivel section 314 is supported by the fixed section 313 so as to be able to rotatably around the swivel axis C1. In this embodiment, the swivel section 314 is formed in the shape of an annular plate with the swivel axis C1 as the center. The fixed section 313 is formed in the shape of a plate perpendicular to the swivel axis C1.

[0030] The pair of rail support sections 312 are configured to support the pair of lifting rails 21. The pair of rail support sections 312 are arranged separately on both sides in the width direction W relative to the swivel support section 311. In this embodiment, the pair of rail support sections 312 are fixed to the fixing section 313. In addition, in this embodiment, each of the pair of rail support sections 312 is provided with a fixing wall 315.

[0031] Each of the pair of fixed walls 315 is formed to extend along the vertical direction. A lifting rail 21 is fixed to each of the pair of fixed walls 315. In this embodiment, each of the pair of fixed walls 315 is formed in the shape of a plate perpendicular to the front-rear direction D. Each of the pair of fixed walls 315 is fixed to the lifting rail 21 in a state where it is in contact with the lifting rail 21 from the front side D1.

[0032] The pair of legs 32 are positioned on both sides in the width direction W with respect to the lifting trajectory of the fork 1. The pair of legs 32 are formed to protrude from the main body 31 toward the rear side D2. In this embodiment, each of the pair of legs 32 has a hollow structure.

[0033] As shown in Figure 2, the plurality of wheels 4 include drive wheels 41. In this embodiment, the plurality of wheels 4 include a pair of drive wheels 41 and two pairs of driven wheels 42.

[0034] In the following explanation, the direction along the rotation axis of the drive wheel 41 will be referred to as the "axial direction L". Furthermore, the direction perpendicular to the axial direction L when viewed from above and below will be referred to as the "travel direction T".

[0035] The drive wheels 41 are among the multiple wheels 4 and are driven by the travel drive unit 5. The drive wheels 41 are supported by the travel drive unit 5. In this embodiment, a pair of drive wheels 41 are arranged coaxially. The pair of drive wheels 41 are arranged side by side with a gap between them in the axial direction L.

[0036] The driven wheels 42 are among the multiple wheels 4 that are not driven by the drive unit including the travel drive unit 5. In this embodiment, a pair of driven wheels 42 are rotatably supported on each of the pair of legs 32. The pair of driven wheels 42 supported on each of the pair of legs 32 are arranged coaxially so as to be spaced apart from each other in the width direction W. In the example shown in Figure 2, the pair of driven wheels 42 are supported on each of the pair of legs 32 in the portion D2 behind the lifting device 2.

[0037] In this embodiment, the difference in rotation of the pair of drive wheels 41 causes the travel drive unit 5, to which the pair of drive wheels 41 are supported, to rotate around the pivot axis C1. When the travel drive unit 5 is rotated at a 90° angle, the pair of drive wheels 41 are rotated, causing the transport vehicle 100 to rotate around the vehicle pivot axis C2 which is aligned vertically. In this embodiment, the vehicle pivot axis C2 is positioned so as to pass through an intermediate position in the width direction W between the pair of driven wheels 42 supported by one leg portion 32 and the pair of driven wheels 42 supported by the other leg portion 32 (a position equally spaced from the pair of driven wheels 42) on the rotation axis of the two pairs of driven wheels 42. The "rotation angle of the travel drive unit 5" is the angle at which the rotation axis of the drive wheels 41 intersects the width direction W.

[0038] The travel drive unit 5 is a device that drives the drive wheels 41. As shown in Figures 4 and 5, in this embodiment, the travel drive unit 5 includes a pair of first support members 51, a second support member 52, a third support member 53, and a pair of travel drive sources 54.

[0039] The pair of first support members 51 are connected to the swivel section 314 so as to rotate integrally with the swivel section 314. The pair of first support members 51 are arranged separately on both sides of the travel direction T with respect to the swivel axis C1. In this embodiment, each of the pair of first support members 51 is formed in a plate shape perpendicular to the travel direction T. The pair of first support members 51 are arranged to extend downward from the swivel section 314.

[0040] The second support member 52 extends along the travel direction T so as to pass through the pivot axis C1. The second support member 52 is positioned to connect the pair of first support members 51.

[0041] The third support member 53 is configured to support a pair of travel drive sources 54. The third support member 53 is positioned between the pair of first support members 51 in the travel direction T. The third support member 53 is supported by the pair of first support members 51. In this embodiment, the third support member 53 comprises a pair of first wall portions 531 and a pair of second wall portions 532.

[0042] Each of the pair of first wall portions 531 is formed in a plate shape perpendicular to the travel direction T. The pair of first wall portions 531 are arranged to face each other with a gap between them in the travel direction T. Each of the pair of first wall portions 531 is connected to a pair of first support members 51.

[0043] Each of the pair of second wall portions 532 is formed in a plate shape perpendicular to the axial direction L. The pair of second wall portions 532 are arranged to face each other with a gap between them in the axial direction L. Each of the pair of second wall portions 532 supports a pair of drive sources 54. In this embodiment, a pair of drive wheels 41 are arranged separately on both sides of the pair of second wall portions 532 in the axial direction L.

[0044] Each of the pair of drive sources 54 is a drive source for a pair of drive wheels 41. The pair of drive sources 54 are configured to drive the pair of drive wheels 41 independently of each other. The pair of drive sources 54 are spaced apart from each other in the axial direction L. Each of the pair of drive sources 54 is supported by a pair of second wall portions 532. In this embodiment, each of the pair of drive sources 54 is an electric motor.

[0045] As shown in Figures 4 and 5, the transport vehicle 100 is equipped with a rotation detection device 6. The rotation detection device 6 is a device that detects the rotation of the drive wheels 41. In this embodiment, the transport vehicle 100 is equipped with a pair of rotation detection devices 6 to detect the rotation of a pair of drive wheels 41.

[0046] The rotation detection device 6 is supported by the drive unit 5. The rotation detection device 6 comprises a driven roller 61 and a rotation sensor 62. The driven roller 61 is a roller that rotates in conjunction with the rotation of the drive wheel 41. The driven roller 61 is positioned so as to be in contact with the outer circumferential surface of the drive wheel 41. The rotation sensor 62 is a sensor that detects the rotation of the driven roller 61. In this embodiment, the rotation sensor 62 is an encoder.

[0047] As shown in Figure 5, the rotation axis of the driven roller 61 is above the rotation axis of the drive wheel 41 and is located at a different position in the direction of travel T from the rotation axis of the drive wheel 41. In Figure 5, "A1" is the rotation axis of the drive wheel 41 and "A2" is the rotation axis of the driven roller 61.

[0048] In this embodiment, the rotation axis of the driven roller 61 is located in at least one of the following ranges: below the upper end of the outer circumferential surface of the drive wheel 41, and between the two ends of the travel direction T on the outer circumferential surface of the drive wheel 41. In the example shown in Figure 5, the rotation axis of the driven roller 61 is located in both the range below the upper end of the outer circumferential surface of the drive wheel 41 and between the two ends of the travel direction T on the outer circumferential surface of the drive wheel 41. In Figure 5, "L1" is a dashed line indicating the position of the upper end of the outer circumferential surface of the drive wheel 41. "L2" is a dashed line indicating the position of one end of the travel direction T on the outer circumferential surface of the drive wheel 41, and "L3" is a dashed line indicating the position of the other end of the travel direction T on the outer circumferential surface of the drive wheel 41.

[0049] Furthermore, in this embodiment, a driven roller 61 is arranged on each of the pair of drive wheels 41. The pair of driven rollers 61 are arranged separately on both sides in the travel direction T with respect to the rotation axis of the pair of drive wheels 41.

[0050] Furthermore, in this embodiment, the rotation detection device 6 is positioned below the bottom surface 311a of the swivel support section 311 and above the rotation axis of the drive wheel 41. The bottom surface 311a is the downward-facing surface of the swivel support section 311. In this embodiment, the bottom surface 311a is the lower end surface of the swivel section 314.

[0051] As shown in Figure 4, in this embodiment, a pair of rotation sensors 62 are arranged to detect the rotation of a pair of driven rollers 61, respectively. In this embodiment, the travel drive source 54 is equipped with a sensor such as an encoder that detects the rotation of the output element of the travel drive source 54. The rotation sensors 62 are provided independently of the sensors mounted on the travel drive source 54. With this configuration, the travel state of the transport vehicle 100 can be monitored in a dual manner, making it easier to improve the accuracy and safety of the travel control of the transport vehicle 100.

[0052] In this embodiment, the rotation detection device 6 further comprises a pair of fixed members 63. Each of the pair of fixed members 63 is fixed to a pair of second wall portions 532. A driven roller 61 and a rotation sensor 62 are supported on each of the pair of fixed members 63. In this embodiment, the driven roller 61 and the rotation sensor 62 are arranged axially L apart with respect to the fixed members 63.

[0053] Furthermore, in this embodiment, the rotation detection device 6 is positioned inward from the outer edge of the turning trajectory of the drive wheel 41 (see the dashed line in Figure 4) when the travel drive unit 5 turns around the turning axis C1, when viewed from above.

[0054] As shown in Figure 4, in this embodiment, the transport vehicle 100 is further equipped with a turning position sensor 7.

[0055] The swivel position sensor 7 is a sensor that detects whether the swivel angle of the travel drive unit 5 with respect to the width direction W is within a set angle range including 90°. The set angle range is set to, for example, 90 ± 20°. In this embodiment, a pair of detectable parts 71 are provided that extend from a pair of first support members 51 so as to be spaced apart from each other in the travel direction T. The pair of detectable parts 71 swivel in conjunction with the swivel of the travel drive unit 5. In this embodiment, when the swivel position sensor 7 detects either of the pair of detectable parts 71, it is determined that the swivel angle of the travel drive unit 5 is within the above set angle range. In this embodiment, the swivel position sensor 7 is supported by the rail support part 312 of the main body part 31.

[0056] [Other Embodiments] (1) In the above embodiment, the rotation axis of the driven roller 61 was described as being located in both the range below the upper end of the outer surface of the drive wheel 41 and the range between the two ends of the running direction T on the outer surface of the drive wheel 41. However, the configuration is not limited to such a configuration, and for example, the rotation axis of the driven roller 61 may be located in either the range below the upper end of the outer surface of the drive wheel 41 or the range between the two ends of the running direction T on the outer surface of the drive wheel 41. Alternatively, the rotation axis of the driven roller 61 may be located above the rotation axis of the drive wheel 41 and at a different position in the running direction T from the rotation axis of the drive wheel 41, and does not have to be located in either the range below the upper end of the outer surface of the drive wheel 41 or the range between the two ends of the running direction T on the outer surface of the drive wheel 41.

[0057] (2) In the above embodiment, a configuration in which the pair of driven rollers 61 are arranged on both sides in the travel direction T with respect to the rotation axis of the pair of drive wheels 41 was described as an example. However, the configuration is not limited to such a configuration, and the pair of driven rollers 61 may be arranged on one side in the travel direction T with respect to the rotation axis of the pair of drive wheels 41.

[0058] (3) In the above embodiment, a configuration in which the travel drive unit 5 rotates around the pivot axis C1 due to the difference in rotation of a pair of drive wheels 41 was described as an example. However, the configuration is not limited to such a configuration, and for example, a configuration in which a drive unit is provided to rotate the travel drive unit 5 around the pivot axis C1 may also be used. In this configuration, there may be only one drive wheel 41.

[0059] (4) In the above embodiment, a configuration in which multiple wheels 4 include drive wheels 41 and driven wheels 42 was described as an example. However, the configuration is not limited to such a configuration, and for example, all wheels 4 may be drive wheels 41.

[0060] (5) In the above embodiment, a configuration in which a pair of forks 1 are arranged side by side with a gap between them in the width direction W was described as an example. However, the configuration is not limited to such a configuration, and a configuration with one fork 1 or three or more forks 1 is also possible.

[0061] (6) The configurations disclosed in each of the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of this disclosure.

[0062] [Summary of this embodiment] The following describes the overview of the transport vehicle mentioned above.

[0063] The transport vehicle is Forks to support the pallet, A lifting device for raising and lowering the fork, Multiple wheels, including the drive wheels, A drive system that drives the aforementioned drive wheels, A transport vehicle comprising the lifting device, a plurality of wheels, and a vehicle body supporting the drive system, A specific direction along the horizontal plane is defined as the front-rear direction, one side of the front-rear direction is defined as the front, the other side of the front-rear direction is defined as the rear, a direction along the horizontal plane that is perpendicular to the front-rear direction is defined as the width direction, a direction along the rotation axis of the drive wheel is defined as the axial direction, and a direction perpendicular to the axial direction when viewed from above is defined as the travel direction. The fork is positioned to protrude from the lifting device toward the rear. The vehicle body comprises a main body that supports the drive unit, and a pair of legs arranged on both sides in the width direction with respect to the lifting trajectory of the fork, so as to protrude from the main body toward the rear. The device further includes a rotation detection device for detecting the rotation of the drive wheel, The drive wheel and the rotation detection device are supported by the drive unit. The rotation detection device comprises a driven roller positioned so as to contact the outer circumferential surface of the drive wheel and rotating in conjunction with the rotation of the drive wheel, and a rotation sensor for detecting the rotation of the driven roller. The rotation axis of the driven roller is located above the rotation axis of the drive wheel and is positioned in a different direction from the rotation axis of the drive wheel.

[0064] This configuration allows the driven rollers of the rotation detection device to be positioned in the space formed diagonally above the drive wheels. This makes it easier to suppress the increase in size of the transport vehicle that would otherwise be required to accommodate the rotation detection device. In other words, it is easier to miniaturize the transport vehicle in a configuration that includes a rotation detection device.

[0065] Here, it is preferable that the rotation axis of the driven roller is located within at least one of the following ranges: below the upper end of the outer circumferential surface of the drive wheel, and between the two ends of the outer circumferential surface of the drive wheel in the direction of travel.

[0066] This configuration makes it easier to further miniaturize the transport vehicle in at least one of the vertical and horizontal directions.

[0067] Furthermore, the plurality of wheels include a pair of drive wheels arranged on the same axle. Each of the pair of drive wheels is fitted with the driven roller, Preferably, the pair of driven rollers are arranged separately on both sides in the direction of travel with respect to the rotation axis of the pair of drive wheels.

[0068] This configuration allows the pair of rotation detection devices to have similar configurations, without requiring them to be symmetrically arranged in the axial direction. Therefore, it is possible to standardize parts between the pair of rotation detection devices, which in turn can reduce the cost of the transport vehicle.

[0069] Furthermore, the main body includes a pivot support section that pivotably supports the travel drive device around a pivot axis along the vertical direction. Preferably, the rotation detection device is positioned below the downward-facing bottom surface of the pivot support and above the rotation axis of the drive wheel.

[0070] This configuration allows for the placement of a rotation detection device in a space below the bottom surface of the swivel support, where it does not interfere with the drive wheels and the travel drive system. Therefore, it is easier to further miniaturize the transport vehicle.

[0071] In the above configuration, it is preferable that the rotation detection device is positioned inward from the outer edge of the turning trajectory of the drive wheel when the travel drive unit turns around the turning axis, as viewed from above.

[0072] This configuration makes it easier to miniaturize the transport vehicle in the direction perpendicular to the pivot axis of the drive wheels.

[0073] Furthermore, it is preferable that the transport vehicle is further equipped with a swivel position sensor that detects whether the swivel angle of the travel drive device in the width direction is within a set angle range including 90°.

[0074] This configuration allows for the detection, with a simple setup, of whether the drive wheels are being driven for straight-line movement of the transport vehicle or for changing the direction of the transport vehicle. [Industrial applicability]

[0075] The technology disclosed herein can be used in transport vehicles. [Explanation of symbols]

[0076] 100: Transport vehicle 1: Fork 2: Lifting device 3: Vehicle body 31: Main body 311: Swivel support section 32: Legs 4: Wheels 41: Drive wheels 5: Drive system 6: Rotation detection device 61: Driven roller 62: Rotation sensor 7: Swivel position sensor P: Palette C1: Rotation axis center D: Anteroposterior direction D1: Front D2: Rear side W: width direction L: Axial direction T: Traveling direction

Claims

1. Forks to support the pallet, A lifting device for raising and lowering the fork, Multiple wheels, including the drive wheels, A drive system that drives the aforementioned drive wheels, A transport vehicle comprising the lifting device, a plurality of wheels, and a vehicle body supporting the drive system, A specific direction along the horizontal plane is defined as the front-rear direction, one side of the front-rear direction is defined as the front, the other side of the front-rear direction is defined as the rear, a direction along the horizontal plane that is perpendicular to the front-rear direction is defined as the width direction, a direction along the rotation axis of the drive wheel is defined as the axial direction, and a direction perpendicular to the axial direction when viewed from above is defined as the travel direction. The fork is positioned to protrude from the lifting device toward the rear. The vehicle body comprises a main body that supports the drive unit, and a pair of legs arranged on both sides in the width direction with respect to the lifting trajectory of the fork, so as to protrude from the main body toward the rear. The device further includes a rotation detection device for detecting the rotation of the drive wheel, The drive wheel and the rotation detection device are supported by the drive unit. The rotation detection device comprises a driven roller positioned so as to contact the outer circumferential surface of the drive wheel and rotating in conjunction with the rotation of the drive wheel, and a rotation sensor for detecting the rotation of the driven roller. A transport vehicle in which the rotation axis of the driven roller is located above the rotation axis of the drive wheel and is positioned in a different direction from the rotation axis of the drive wheel.

2. The transport vehicle according to claim 1, wherein the rotation axis of the driven roller is located in at least one of the following ranges: below the upper end of the outer circumferential surface of the drive wheel, and between the two ends of the outer circumferential surface of the drive wheel in the direction of travel.

3. The plurality of wheels include a pair of drive wheels arranged on the same axle, Each of the pair of drive wheels is fitted with the driven roller, The transport vehicle according to claim 1 or 2, wherein the pair of driven rollers are arranged separately on both sides in the direction of travel with respect to the rotation axis of the pair of drive wheels.

4. The main body includes a pivot support portion that pivotably supports the travel drive device around a pivot axis along the vertical direction, The transport vehicle according to claim 1 or 2, wherein the rotation detection device is positioned below the downward-facing bottom surface of the swivel support and above the rotation axis of the drive wheel.

5. The transport vehicle according to claim 4, wherein the rotation detection device is positioned inward from the outer edge of the turning trajectory of the drive wheel when the travel drive unit turns around the turning axis, in the view from the up and down direction.

6. The transport vehicle according to claim 4, further comprising a turning position sensor for detecting whether the turning angle of the travel drive device in the width direction is within a set angle range including 90°.

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