Driven wheel, bogie, and method for controlling bogie

Abstract

To improve driving stability. [Solution] The driven wheel 210 includes a driven wheel base 220, a driven wheel turning section 212 that is arranged to be able to turn infinitely relative to the driven wheel base 220, a driven wheel 215 arranged on the driven wheel turning section 212, an angle detection section 216 that detects the rotation angle of the driven wheel turning section 212, and a driven wheel drive mechanism 211 that inputs rotational force to the driven wheel turning section 212.

Description

[Technical Field]

[0001] The present invention relates to a driven wheel, a bogie, and a method for controlling the bogie. [Background technology]

[0002] For example, Patent Document 1 describes an automated guided vehicle as a conventional technique. This automated guided vehicle has casters attached to the underside of the four corners of its base. The automated guided vehicle also has two drive wheels attached to the underside of the center of the base, and the drive wheels are driven and rotated by controlling the rotation of a motor, which serves as a power source, to travel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-018603 Summary of the Invention [Problem to be solved by the invention]

[0004] The driven wheels that make up the caster are preferably able to change direction freely to ensure freedom of rotation, but on the other hand, if they move freely on uneven or rough roads, their directionality becomes unstable, and they are unable to secure the steering angle in the desired direction of travel, which places a burden on the drive side. For this reason, they cannot be fully effective when used in a wheel drive module that can move in all directions.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a driven wheel, a bogie, and a method for controlling the bogie that can prevent a load on the drive side and improve running stability by controlling the steering angle in the desired direction of travel. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one aspect of the present disclosure provides a driven wheel that includes a driven wheel base, a driven wheel turning section that is arranged to be infinitely rotatable relative to the driven wheel base, a driven wheel arranged on the driven wheel turning section, an angle detection section that detects the rotation angle of the driven wheel turning section, and a driven wheel drive mechanism that inputs a rotational force to the driven wheel turning section.

[0007] In a preferred embodiment, the driven wheel further includes a power connection / disconnection mechanism that connects or disconnects the input of rotational force from the driven wheel drive mechanism to the driven wheel turning portion.

[0008] A desirable aspect of the above-mentioned driven wheel further includes a driven wheel control device provided in the driven wheel turning section, which inputs a detection signal from the angle detection section and outputs a drive signal to the driven wheel drive mechanism, and a battery provided in the driven wheel turning section, which supplies power to the driven wheel drive mechanism, the angle detection section, and the driven wheel control device.

[0009] In order to achieve the above object, a bogie according to one aspect of the present disclosure includes a bogie body, the aforementioned driven wheels attached to the bogie body, and drive wheels attached to the bogie body.

[0010] In order to achieve the above-mentioned object, one aspect of the present disclosure provides a method for controlling the above-mentioned bogie, which includes the steps of driving the drive wheels and detecting the rotation angle of the driven wheel swivel unit, and, if the driven wheel swivel unit deviates from the rotation angle, driving the driven wheel drive mechanism to maintain the rotation angle. [Effects of the Invention]

[0011] According to the present disclosure, driving stability can be improved. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a bottom view illustrating an example of the configuration of a cart according to an embodiment. [Figure 2] FIG. 2 is a bottom view showing another example of the configuration of the cart according to the embodiment. [Figure 3] FIG. 3 is a schematic diagram of a configuration example of a drive wheel according to the embodiment. [Figure 4] FIG. 4 is a perspective view of a first configuration example of a driven wheel according to the embodiment. [Figure 5] FIG. 5 is a schematic diagram of a first configuration example of a driven wheel according to an embodiment. [Figure 6] FIG. 6 is a perspective view of a second configuration example of the driven wheel of the embodiment. [Figure 7] FIG. 7 is a schematic diagram of a second configuration example of the driven wheel of the embodiment. [Figure 8] FIG. 8 is a perspective view of a third configuration example of the driven wheel of the embodiment. [Figure 9] FIG. 9 is a schematic diagram of a third configuration example of a driven wheel according to an embodiment. [Figure 10] FIG. 10 is a flowchart illustrating a method for controlling a carriage according to an embodiment. [Figure 11] FIG. 11 is a process diagram of the method for controlling the carriage according to the embodiment. [Figure 12] FIG. 12 is a process diagram of the method for controlling the carriage according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Preferred embodiments of the drive wheels and bogies according to the present disclosure will be described in detail below with reference to the drawings. Note that the present invention is not limited to these embodiments, and when there are multiple embodiments, the present invention also includes configurations that combine the embodiments. Furthermore, the components in the embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range.

[0014] 1 and 2 are bottom views showing an example of the configuration of a carriage according to an embodiment.

[0015] The bogies 100A and 100B shown in FIGS. 1 and 2 include a bogie body 101, driving wheels 110, driven wheels 210, a control device 102, and a power supply unit 103.

[0016] The bogie body 101 is, for example, a flat plate material, and in this embodiment, has a rectangular shape in plan view when viewed from above. Although not explicitly shown in the drawings, the bogie body 101 may have a handle fixed to the top surface. The bogie body 101 constitutes a drive wheel base 120 (see FIG. 3) on which the drive wheels 110 are mounted. Alternatively, the drive wheel base 120 is integrally attached to the bogie body 101. The bogie body 101 constitutes a driven wheel base 220 (see FIGS. 4 to 9) on which the driven wheels 210 are mounted. Alternatively, the bogie body 101 has a driven wheel base 220 integrally attached to it.

[0017] In the bogie 100A shown in Fig. 1, the drive wheels 110 are attached at two locations on the four corners of the bottom (lower surface) side of the bogie body 101. The drive wheels 110 are arranged diagonally between the four corners. Furthermore, the drive wheels 110 do not have to be arranged diagonally. For example, although not explicitly shown in the figure, if the straight forward direction A is defined as the direction along the long side of the bogie body 101, the drive wheels 110 may be attached at two locations on the rear side of the four corners.

[0018] In the bogie 100B shown in Figure 2, if the straight forward direction A is defined as the direction along the long side of the bogie body 101, the drive wheels 110 are attached at two rear positions on the four corners of the bottom side of the bogie body 101.

[0019] The detailed configuration of the drive wheels 110 will be described later.

[0020] 1, the driven wheels 210 are attached to two locations on the four corners of the bottom surface of the bogie body 101. The driven wheels 210 are arranged diagonally between the four corners. Furthermore, the drive wheels 210 do not have to be arranged diagonally. For example, although not explicitly shown in the figure, if the straight forward direction A is defined as the direction along the long side of the bogie body 101, the driven wheels 210 may be attached to two locations on the front side of the four corners.

[0021] In the bogie 100B shown in Figure 2, if the straight forward direction A is defined as the direction along the long side of the bogie body 101, the driven wheel 210 is attached to one location in the center of the left and right sides of the front side of the bottom surface of the bogie body 101.

[0022] The detailed configuration of the driven wheel 210 will be described later.

[0023] The control device 102 controls the driving wheels 110 and the driven wheels 210. An input device (controller) 104 is connected to the control device 102 by wire or wirelessly, and controls the driving wheels 110 and the driven wheels 210 based on the operation of the input device 104. Alternatively, the control device 102 controls the driving wheels 110 and the driven wheels 210 based on an input program. The control device 102 includes a computer system. The computer system includes a processor such as a CPU (Central Processing Unit) and a memory such as a ROM (Read Only Memory) or RAM (Random Access Memory).

[0024] The power supply unit 103 supplies power to the driving wheels 110 , the driven wheels 210 , the control device 102 and the input device 104 .

[0025] The carts 100A and 100B can load an object to be transported onto the cart body 101, and can be configured as automatic guided vehicles (AGVs). The carts 100A and 100B can place equipment on the cart body 101, and can be configured as traveling equipment. Examples of equipment include a variety of equipment, such as a transport cart, a hand lifter, a forklift, a picking robot, and medical equipment.

[0026] FIG. 3 shows the drive wheels of the embodiment.

[0027] The drive wheel 110 is provided on the drive wheel base 120 or the bogie body 101 (hereinafter referred to as the drive wheel base 120) and includes a drive wheel drive mechanism 11, a drive wheel turning unit 12, a drive wheel transmission mechanism 13, a drive wheel power conversion mechanism 14, and a drive wheel 15.

[0028] The drive wheel drive mechanism 11 inputs a rotational force. The drive wheel swivel unit 12 is rotatably mounted on the drive wheel base 120. The drive wheel transmission mechanism 13 transmits the rotational force input by the drive wheel drive mechanism 11. The drive wheel power conversion mechanism 14 transmits the rotational force from the drive wheel transmission mechanism 13 to the drive wheels 15. The drive wheels 15 are rotatable by the rotational force input via the drive wheel drive mechanism 11, the drive wheel transmission mechanism 13, and the drive wheel power conversion mechanism 14, and can be steered by the drive wheel swivel unit 12.

[0029] The drive wheel drive mechanism 11 has a drive wheel first drive mechanism 22A and a drive wheel second drive mechanism 22B. The drive wheel first drive mechanism 22A includes a drive wheel first drive unit 23A, a drive wheel first drive pulley 24A, a drive wheel first input shaft 25A, a drive wheel first driven pulley 26A, and a drive wheel first drive belt 27A. The drive wheel first drive unit 23A is composed of a motor. The drive wheel first drive unit 23A is fixed to the drive wheel base 120. The drive wheel first drive unit 23A has a drive shaft 23Aa extending in the vertical direction. The drive wheel first drive pulley 24A is fixed to the drive shaft 23Aa. The drive wheel first input shaft 25A extends in the vertical direction parallel to the drive shaft 23Aa and is supported rotatably about an axis O1. The drive wheel first driven pulley 26A is fixed to the drive wheel first input shaft 25A. Drive wheel first drive belt 27A is formed in a ring shape and is wound around drive wheel first driven pulley 26A and drive wheel first drive pulley 24A. Therefore, in drive wheel first drive mechanism 22A, drive wheel first drive unit 23A drives drive wheel first drive pulley 24A to rotate, and this rotation is transmitted from drive wheel first drive pulley 24A to drive wheel first driven pulley 26A via drive wheel first drive belt 27A, thereby rotating drive wheel first input shaft 25A.

[0030] The second drive mechanism 22B includes a second drive unit 23B, a second drive pulley 24B, a second input shaft 25B, a second driven pulley 26B, and a second drive belt 27B. The second drive unit 23B is configured with a motor. The second drive unit 23B is fixed to the base 120. The second drive unit 23B has a drive shaft 23Ba extending in the vertical direction. The second drive pulley 24B is fixed to the drive shaft 23Ba. The second drive pulley 24B has the same diameter as the first drive pulley 24A. The second input shaft 25B is provided to extend in the vertical direction parallel to the drive shaft 23Ba and is supported for rotation about an axis O1. The drive wheel second input shaft 25B is cylindrical, has the drive wheel first input shaft 25A inserted therethrough, and is disposed on the drive wheel first input shaft 25A via a bearing so as to rotate independently of the drive wheel first input shaft 25A. The drive wheel second driven pulley 26B is fixed to the drive wheel second input shaft 25B. The drive wheel second driven pulley 26B has the same diameter as the drive wheel first driven pulley 26A. The drive wheel second drive belt 27B is annular and is wound around the drive wheel second driven pulley 26B and the drive wheel second drive pulley 24B. Therefore, the drive wheel second drive mechanism 22B drives the drive wheel second drive unit 23B, causing the drive wheel second drive pulley 24B to rotate. This rotation is transmitted from the drive wheel second drive pulley 24B to the drive wheel second driven pulley 26B via the drive wheel second drive belt 27B, causing the drive wheel second input shaft 25B to rotate.

[0031] The drive wheel turning unit 12 has a drive wheel turning shaft 35 and a drive wheel support member 36. The drive wheel turning shaft 35 is rotatably supported via bearings on the drive wheel base 120 so as to be able to turn infinitely around an axis O1. The drive wheel turning shaft 35 is supported so as to be able to rotate relatively to the drive wheel base 120 around the axis O1, regardless of the rotation of the first drive wheel input shaft 25A and the second drive wheel input shaft 25B. The drive wheel support members 36 form a pair and are provided below the drive wheel turning shaft 35, extending below the drive wheel base 120. The drive wheel support members 36 support the drive wheels 15.

[0032] The drive wheel 15 is integrally provided with a drive wheel axle 37 that extends along an axis O2 that is perpendicular to the direction in which the axis O1 extends (the up-down direction). Each end of the drive wheel axle 37 along the axis O2 is rotatably supported by a corresponding drive wheel support member 36 via a bearing. In addition, the rotation axis O5 of the drive wheel 15 that extends along the vertical direction intersecting the axis O2 of the drive wheel axle 37 is offset from the axis O1 of the drive wheel turning shaft 35 in the horizontal direction that is perpendicular to the axis O2 of the drive wheel axle 37.

[0033] The drive wheel transmission mechanism 13 has a drive wheel first transmission mechanism 13A and a drive wheel second transmission mechanism 13B. The drive wheel first transmission mechanism 13A is configured to include a drive wheel first transmission drive gear 38A, a drive wheel first transmission driven gear 39A, and a drive wheel first output shaft 40A. The drive wheel second transmission mechanism 13B is configured to include a drive wheel second transmission drive gear 38B, a drive wheel second transmission driven gear 39B, and a drive wheel second output shaft 40B. In this embodiment, the drive wheel first transmission drive gear 38A, the drive wheel first transmission driven gear 39A, the drive wheel second transmission drive gear 38B, and the drive wheel second transmission driven gear 39B are configured as spur gears.

[0034] In the drive wheel first transmission mechanism 13A, the drive wheel first transmission drive gear 38A, the drive wheel first transmission driven gear 39A, and the drive wheel first output shaft 40A are arranged on the drive wheel support member 36 of the drive wheel turning unit 12. The drive wheel first transmission drive gear 38A is fixed to the lower end of the drive wheel first input shaft 25A, which passes through the drive wheel second input shaft 25B. The drive wheel first transmission driven gear 39A meshes with the drive wheel first transmission drive gear 38A. The drive wheel first transmission driven gear 39A is fixed to the drive wheel first output shaft 40A. The drive wheel first output shaft 40A is supported by the drive wheel support member 36 so as to be rotatable about an axis O3.

[0035] In the drive wheel second transmission mechanism 13B, the drive wheel second transmission drive gear 38B, the drive wheel second transmission driven gear 39B, and the drive wheel second output shaft 40B are arranged on another drive wheel support member 36 of the drive wheel turning section 12. The drive wheel second transmission drive gear 38B is fixed to the lower end of the drive wheel second input shaft 25B. The drive wheel second transmission driven gear 39B meshes with the drive wheel second transmission drive gear 38B. The drive wheel second transmission driven gear 39B is fixed to the drive wheel second output shaft 40B. The drive wheel second input shaft 25B is supported by the drive wheel support member 36 so as to be rotatable about an axis O4.

[0036] The driving wheel power converting mechanism 14 has a driving wheel first power converting mechanism 14A and a driving wheel second power converting mechanism 14B. The driving wheel first power converting mechanism 14A is composed of a driving wheel first conversion drive gear 41A and a driving wheel first conversion driven gear 42A. The driving wheel second power converting mechanism 14B is composed of a driving wheel second conversion drive gear 41B and a driving wheel second conversion driven gear 42B. In this embodiment, the driving wheel first conversion drive gear 41A, the driving wheel first conversion driven gear 42A, the driving wheel second conversion drive gear 41B, and the driving wheel second conversion driven gear 42B are composed of bevel gears.

[0037] In the driving wheel first power converting mechanism 14A, the driving wheel first conversion drive gear 41A is fixed to a lower end of the driving wheel first output shaft 40A. The driving wheel first conversion driven gear 42A is fixed to one end of the driving wheel axle 37. The driving wheel first conversion drive gear 41A meshes with the driving wheel first conversion driven gear 42A. Therefore, the driving wheel first power converting mechanism 14A converts rotation around the axis O3 of the driving wheel first output shaft 40A into rotation around the axis O2 of the driving wheel axle 37.

[0038] In the driving wheels second power converting mechanism 14B, the driving wheels second conversion drive gear 41B is fixed to the lower end of the driving wheels second output shaft 40B. The driving wheels second conversion driven gear 42B is fixed to the other end of the driving wheels axle 37. The driving wheels second conversion drive gear 41B meshes with the driving wheels second conversion driven gear 42B. Therefore, the driving wheels second power converting mechanism 14B converts rotation about the axis O4 of the driving wheels second output shaft 40B into rotation about the axis O2 of the driving wheels axle 37.

[0039] The drive wheels 110 can rotate and steer the drive wheels 15 by rotating the drive wheel first input shaft 25A and the drive wheel second input shaft 25B using the drive wheel drive mechanism 11. For example, the drive wheels 110 can rotate without steering the drive wheels 15 by rotating the drive wheel first input shaft 25A and rotating the drive wheel second input shaft 25B in the opposite direction to the drive wheel first input shaft 25A, and by making the rotational speeds (rotational speeds) of the drive wheel first input shaft 25A and the drive wheel second input shaft 25B the same. At this time, by making the rotational speeds (rotational speeds) of the drive wheel first input shaft 25A and the drive wheel second input shaft 25B different, the drive wheels 15 can be steered while rotating or stopped.

[0040] Specifically, when the drive wheel first input shaft 25A of the drive wheel 110 rotates in the A1 direction, the drive wheel first transmission drive gear 38A rotates in the same direction, the drive wheel first transmission driven gear 39A rotates in the A2 direction together with the drive wheel first output shaft 40A, and the drive wheel first conversion drive gear 41A rotates in the same direction. Then, the drive wheel first conversion driven gear 42A rotates in the A3 direction, causing the drive wheel axle 37 to rotate in the same direction. Meanwhile, when the drive wheel 110 rotates the drive wheel second input shaft 25B in the B1 direction, opposite to the A1 direction, the drive wheel second transmission drive gear 38B rotates in the same direction, the drive wheel second transmission driven gear 39B rotates in the B2 direction together with the drive wheel second output shaft 40B, and the drive wheel second conversion drive gear 41B rotates in the same direction. Then, the drive wheel second conversion driven gear 42B rotates in the B3 direction, causing the drive wheel axle 37 to rotate in the same direction. Here, since the A3 direction and the B3 direction are the same rotation direction, if the first drive wheel input shaft 25A and the second drive wheel input shaft 25B rotate at the same rotation speed, the drive wheels 15 rotate without turning.

[0041] At this time, when the rotation speed of the drive wheel second input shaft 25B is reduced relative to the rotation speed of the drive wheel first input shaft 25A, the rotation speed input from the drive wheel second conversion drive gear 41B to the drive wheel axle 37 via the drive wheel second conversion driven gear 42B becomes lower than the rotation speed input from the drive wheel first conversion drive gear 41A to the drive wheel axle 37 via the drive wheel first conversion driven gear 42A. Then, the drive wheel turning shaft 35 rotates by the rotation speed difference, turning and steering the drive wheel 15. Furthermore, when the rotation of the drive wheel second input shaft 25B is stopped, the rotation speed input from the drive wheel second conversion drive gear 41B to the drive wheel axle 37 via the drive wheel second conversion driven gear 42B becomes zero, and the drive wheel 15 turns and steers without rotating.

[0042] The drive wheels 110 have a differential omnidirectional movement mechanism. That is, the rotational force of the drive wheel first input shaft 25A and the drive wheel second input shaft 25B is transmitted to the drive wheel first output shaft 40A and the drive wheel second output shaft 40B via the drive wheel first transmission mechanism 13A and the drive wheel second transmission mechanism 13B, and is then transmitted from the drive wheel first output shaft 40A and the drive wheel second output shaft 40B to each end of the drive wheel axle 37 via the drive wheel first power conversion mechanism 14A and the drive wheel second power conversion mechanism 14B. The drive wheels 110 can switch between rotation and steering of the drive wheels 15 by adjusting the rotation speed of the drive wheel first input shaft 25A and the drive wheel second input shaft 25B. Therefore, the bogies 100A, 100B equipped with the drive wheels 110 are capable of omnidirectional movement.

[0043] Furthermore, the drive wheel 110 is arranged such that the rotation axis O5 of the drive wheel 15, which is along the vertical direction intersecting the axis O2 of the drive wheel axle 37, is offset in the horizontal direction perpendicular to the axis O2 of the drive wheel axle 37 with respect to the axis O1 of the drive wheel turning shaft 35. Therefore, when the drive wheel 110 does not drive the drive wheel 15, the drive wheel 15 can passively turn due to an external force acting from the horizontal direction. In other words, the drive wheel 110 can automatically travel and steer, and can also be manually traveled and steered by an operator.

[0044] The drive wheel 110 is not limited to the above-described configuration, and the gear described as a spur gear may be configured as a helical gear, for example, and the gear described as a bevel gear may be configured as a screw gear, a worm gear, a crown gear, a universal joint, for example. Furthermore, the configurations of the drive wheel drive mechanism 11, the drive wheel transmission mechanism 13, and the drive wheel power conversion mechanism 14 of the drive wheel 110 may be changed as appropriate, as long as the above-described functions are obtained.

[0045] In addition, in the bogie 100B shown in Figure 2, the two drive wheels 110, although not explicitly shown in the figure, may be configured as differential two-wheel drive wheels that do not have a turning function and can steer the bogie 100B by each driving the drive wheel to rotate forward or backward.

[0046] Figures 4 to 9 show driven wheels 210 according to an embodiment. Here, Figures 4 and 5 show a driven wheel 210A according to a first configuration example, Figures 6 and 7 show a driven wheel 210B according to a second configuration example, and Figures 8 and 9 show a driven wheel 210C according to a third configuration example.

[0047] As shown in Figures 4 and 5, the driven wheel 210A of the first configuration example is provided on the driven wheel base 220 or the bogie body 101 (hereinafter referred to as the driven wheel base 220), and includes a driven wheel drive mechanism 211, a driven wheel turning unit 212, a driven wheel 215, and an angle detection unit 216.

[0048] The driven wheel drive mechanism 211 inputs a rotational force. The driven wheel turning unit 212 is provided rotatably about an axis O21 extending in the vertical direction relative to the driven wheel base 220. The driven wheel 215 can be steered by the driven wheel turning unit 212, which rotates by the rotational force input by the driven wheel drive mechanism 211. The angle detection unit 216 detects the rotation angle of the driven wheel turning unit 212.

[0049] The driven wheel drive mechanism 211 includes a driven wheel drive unit 223 and a driven wheel transmission mechanism 224. The driven wheel drive unit 223 is composed of a motor. The driven wheel drive unit 223 is fixed to the driven wheel base 220. The driven wheel drive unit 223 has a drive shaft 223a that extends in the vertical direction and is parallel to the axis O21. The driven wheel transmission mechanism 224 includes a driven wheel drive gear 224a and a driven wheel driven gear 224b that mesh with each other. The driven wheel drive gear 224a is fixed to the drive shaft 223a. The driven wheel driven gear 224b is fixed to the driven wheel turning unit 212. Therefore, in the driven wheel drive mechanism 211, driven wheel drive gear 224a rotates when driven wheel drive unit 223 is driven, and this rotation is transmitted to driven wheel driven gear 224b, causing rotation of driven wheel turning unit 212. In this embodiment, driven wheel drive gear 224a and driven wheel driven gear 224b are configured as spur gears. However, driven wheel drive gear 224a and driven wheel driven gear 224b may also be configured as helical gears, for example.

[0050] The driven wheel swivel unit 212 has a driven wheel swivel shaft 235 and a driven wheel support member 236. The driven wheel swivel shaft 235 is rotatably supported via a bearing on the driven wheel base 220 so as to be able to rotate infinitely around an axis O21. A driven wheel driven gear 224b is fixed to the driven wheel swivel shaft 235, and the driven wheel swivel shaft 235, together with the driven wheel driven gear 224b, is supported so as to be able to rotate relatively around the axis O21 on the driven wheel base 220. The driven wheel support members 236 form a pair and are provided below the driven wheel swivel shaft 235, extending below the driven wheel base 220. The driven wheel support members 236 support the driven wheels 215.

[0051] The driven wheel 215 is integrally provided with a driven wheel axle 237 extending along an axis O22 perpendicular to the direction in which the axis O21 extends (the up-down direction). Each end of the driven wheel axle 237 along the axis O22 is rotatably supported via bearings on the respective driven wheel support members 236. In addition, the rotation axis O25 of the driven wheel 215 along the vertical direction intersecting the axis O22 of the driven wheel axle 237 is offset in the horizontal direction perpendicular to the axis O22 of the driven wheel axle 237 with respect to the axis O21 of the driven wheel turning shaft 235 when viewed along the axis O22 (see FIG. 4).

[0052] The angle detection unit 216 is fixed to the driven wheel base 220. The angle detection unit 216 has a detection shaft 216a that extends in the vertical direction and is centered on the axis O21. The detection shaft 216a is connected to the driven wheel turning shaft 235 of the driven wheel turning unit 212. Therefore, the detection shaft 216a of the angle detection unit 216 rotates together with the driven wheel turning shaft 235, and the angle detection unit 216 detects the rotation angle of the driven wheel turning unit 212 from the rotation angle of this detection shaft 216a.

[0053] The driven wheel 210A can steer the driven wheel 215 by rotating the driven wheel turning shaft 235 using the driven wheel drive mechanism 211.

[0054] Furthermore, the driven wheel 210A is disposed such that the rotation axis O25 of the driven wheel 215, which is aligned along the vertical direction intersecting the axis O22 of the driven wheel axle 237, is offset in the horizontal direction perpendicular to the axis O22 of the driven wheel axle 237 with respect to the axis O21 of the driven wheel turning shaft 235. Therefore, the driven wheel 210A can passively turn by an external force acting on the driven wheel 215 from the horizontal direction. That is, the driven wheel 210A can be automatically steered, and can also be manually driven and steered by an operator. Furthermore, the angle detection unit 216 detects the rotation angle of the driven wheel 215 when the driven wheel 210A is steered.

[0055] 6 and 7, the driven wheel 210B of the second configuration example is different from the driven wheel 210A of the first configuration example in that it further includes a power connection / disconnection mechanism 217, but other configurations are similar. Therefore, for the driven wheel 210B of the second configuration example, the same components as those of the driven wheel 210A of the first configuration example are assigned the same reference numerals, and descriptions thereof will be omitted.

[0056] The driven wheel 210B of the second configuration example is provided on the driven wheel base 220 or the bogie body 101 (hereinafter referred to as the driven wheel base 220), and includes a driven wheel drive mechanism 211, a driven wheel turning unit 212, a driven wheel 215, an angle detection unit 216, and a power connection / disconnection mechanism 217.

[0057] The power connecting / disconnecting mechanism 217 connects or disconnects the input of rotational force from the driven wheel drive mechanism 211 to the driven wheel turning unit 212. The power connecting / disconnecting mechanism 217 is configured as, for example, an electromagnetic clutch or a manual clutch, and is interposed on the drive shaft 223a of the driven wheel drive mechanism 211. In the connected state, the power connecting / disconnecting mechanism 217 allows the input of rotational force from the driven wheel drive unit 223 to the driven wheel transmission mechanism 224 via the drive shaft 223a, and in the disconnected state, disables the input of rotational force from the driven wheel drive unit 223 to the driven wheel transmission mechanism 224 via the drive shaft 223a.

[0058] In driven wheel 210B, by setting power connecting / disconnecting mechanism 217 to a connected state, rotation of driven wheel turning unit 212, and therefore turning of driven wheel 215, is performed by driving of driven wheel drive mechanism 211. In addition, in driven wheel 210B, by setting power connecting / disconnecting mechanism 217 to a disconnected state, rotation of driven wheel turning unit 212 is performed passively by an external force acting on driven wheel 215 from the horizontal direction. Note that angle detection unit 216 detects the rotation angle of driven wheel turning unit 212 regardless of the state of power connecting / disconnecting mechanism 217.

[0059] 8 and 9, the driven wheel 210C of the third configuration example differs from the driven wheel 210A of the first configuration example in that it includes a driven wheel control device 218 and a battery 219, but other basic configurations are similar. Therefore, for the driven wheel 210C of the third configuration example, the same components as those of the driven wheel 210A of the first configuration example are assigned the same reference numerals, and descriptions thereof will be omitted.

[0060] The driven wheel 210C of the third configuration example is entirely mounted below the driven wheel base 220 and includes a driven wheel drive mechanism 211, a driven wheel turning unit 212, a driven wheel 215, an angle detection unit 216, a driven wheel control device 218, and a battery 219.

[0061] A fixed shaft 220a having an axis O21 as its center is provided on the underside of the driven wheel base 220. The driven wheel base 220 is attached to the bogie body 101.

[0062] In the driven wheel drive mechanism 211, the driven wheel drive unit 223 is fixed to the driven wheel turning unit 212. In the driven wheel drive mechanism 211, a driven wheel drive gear 224a of the driven wheel transmission mechanism 224 is fixed to the drive shaft 223a. In the driven wheel drive mechanism 211, a driven wheel driven gear 224b of the driven wheel transmission mechanism 224 is fixed to the fixed shaft 220a around the axis O21 and meshes with the driven wheel drive gear 224a.

[0063] The driven wheel swivel unit 212 is rotatably supported such that the driven wheel swivel shaft 235 can infinitely swivel around the axis O21 relative to the fixed shaft 220a of the driven wheel base 220 via a bearing.

[0064] Angle detection unit 216 is fixed to driven wheel turning shaft 235 of driven wheel turning unit 212. Detection shaft 216a of angle detection unit 216 is connected to fixed shaft 220a. Therefore, angle detection unit 216 rotates together with driven wheel turning shaft 235, causing detection shaft 216a on the fixed side to rotate, and the rotation angle of driven wheel turning unit 212 is detected from the rotation angle of detection shaft 216a.

[0065] The driven wheel control device 218 controls the driven wheel 210C. Specifically, the driven wheel control device 218 drives the driven wheel drive unit 223 in the driven wheel drive mechanism 211 to control the rotation angle of the driven wheel turning unit 212. The driven wheel control device 218 wirelessly transmits the rotation angle of the driven wheel turning unit 212 detected by the angle detection unit 216 to the control device 102. The driven wheel control device 218 receives the rotation angle instructed from the control device 102. That is, the driven wheel control device 218 sends the rotation angle of the driven wheel turning unit 212 detected by the angle detection unit 216 to the control device 102, while driving the driven wheel drive unit 223 to maintain the rotation angle received from the control device 102.

[0066] The battery 219 is a battery that supplies power to the driven wheel control device 218. The battery 219 is rechargeable. The battery 219 is fixed to the driven wheel turning unit 212.

[0067] The driven wheel 210C of the third configuration example is configured as a single assembled assembly including the driven wheel base 220, and is attached to the bogie body 101 via the driven wheel base 220.

[0068] Fig. 10 is a flow chart showing the method for controlling the carriage according to the embodiment, and Figs. 11 and 12 are process diagrams of the method for controlling the carriage according to the embodiment.

[0069] As described above, the bogies 100A, 100B travel by controlling the drive wheels 110 and the driven wheels 210 by the control device 102 based on the operation of the input device 104 or a program. That is, the control method of the embodiment is control by the control device 102. For convenience, the control method of the embodiment will be described for the case where the bogies travel in a straight forward direction A as shown in Figs. 11 and 12.

[0070] 10, in step S1, the control device 102 controls the drive wheels 110 to travel in a predetermined direction (straight forward direction A), and detects the rotation angle of the driven wheel swivel unit 212 by the angle detection unit 216 as the steering direction in which the driven wheels 210 follow in accordance with the control of the drive wheels 110 (see FIGS. 11(a) and 12(a)). That is, the control device 102 controls the drive wheels 110 to travel the bogies 100A, 100B in the predetermined direction, and inputs a detection signal that detects the rotation angle of the driven wheel swivel unit 212 to determine whether the bogies 100A, 100B are traveling in the predetermined direction, thereby performing feedback control.

[0071] In step S1, the control device 102 does not drive and control the driven wheel drive unit 223 of the driven wheel 210. That is, the driven wheel 210 is in a state where the driven wheel 215 can freely change direction. Note that, in the case where the driven wheel 210 includes a power connecting / disconnecting mechanism 217 like the driven wheel 210B, in step S1 the control device 102 may control the power connecting / disconnecting mechanism 217 to a disconnected state, thereby allowing the driven wheel 215 to freely change direction.

[0072] In step S2, the control device 102 determines whether the driven wheel turning unit 212 has deviated from the rotation angle. The control device 102 determines that the rotation angle has deviated from the rotation angle when the rotation angle of the driven wheel turning unit 212, which is the steering direction in which the driven wheel 210 is driven when the drive wheel 110 is controlled in step S1, has changed by a predetermined range (for example, ±5°). Deviation of the rotation angle of the driven wheel turning unit 212 can occur, for example, when an obstacle 500 such as dirt or unevenness is present in the traveling direction of the driven wheel 210 as shown in Figures 11(b) and 12(b), and this obstacle 500 prevents the driven wheel 215 from traveling.

[0073] In step S3, if driven wheel turning unit 212 deviates from the rotation angle in step S2 (step S2: Yes), control device 102 outputs a drive signal to drive driven wheel drive unit 223 of the driven wheel drive mechanism so as to maintain the rotation angle. Note that, in a case where power connection / disconnection mechanism 217 is included like driven wheel 210B, control device 102 controls power connection / disconnection mechanism 217 to a connected state in step S3. Note that, if driven wheel turning unit 212 does not deviate from the rotation angle in step S2 (step S2: No), control device 102 continues the control of step S1.

[0074] By controlling step S3, the traveling direction of the driven wheels 210 is returned to a predetermined direction, as shown in Figures 11(c) and 12(c), thereby avoiding a situation in which the steering direction of the bogies 100A, 100B is changed by the obstacle 500.

[0075] In addition, in the driven wheel 210C including the driven wheel control device 218, the driven wheel control device 218 transmits the detection result of the angle detection unit 216 to the control device 102, and receives instructions from the control device 102 and drives the driven wheel drive mechanism 211.

[0076] The driven wheel 210 of the above-described embodiment is characterized by including a driven wheel base 220, a driven wheel turning unit 212 that is arranged to be able to turn infinitely relative to the driven wheel base 220, a driven wheel 215 arranged on the driven wheel turning unit 212, an angle detection unit 216 that detects the rotation angle of the driven wheel turning unit 212, and a driven wheel drive mechanism 211 that inputs a rotational force to the driven wheel turning unit 212.

[0077] According to this driven wheel 210, the traveling direction is detected from the rotation angle of the driven wheel turning unit 212, and the driving direction is changed by rotating the driven wheel turning unit 212 using the driven wheel drive mechanism 211, so that even if the traveling direction deviates due to an obstacle 500 or the like, this can be corrected. As a result, by controlling the steering angle of this driven wheel 210 in the desired traveling direction, it is possible to prevent it from becoming a load on the drive side and improve driving stability.

[0078] Moreover, the driven wheel 210 of the embodiment further includes a power connection / disconnection mechanism 217 that connects or disconnects the input of rotational force from the driven wheel drive mechanism 211 to the driven wheel turning portion 212 .

[0079] According to this driven wheel 210, by connecting the power connection / disconnection mechanism 217 when rotational force is input from the driven wheel drive mechanism 211 to the driven wheel turning section 212 and disconnecting the power connection / disconnection mechanism 217 at other times, resistance of the driven wheel drive mechanism 211 to the driven wheel turning section 212 is eliminated, allowing for smooth driving.

[0080] In addition, the embodiment of the driven wheel 210 further includes a driven wheel control device 218 provided in the driven wheel turning unit 212, which inputs a detection signal from the angle detection unit 216 and outputs a drive signal to the driven wheel drive mechanism 211, and a battery 219 provided in the driven wheel turning unit 212, which supplies power to the driven wheel drive mechanism 211, the angle detection unit 216, and the driven wheel control device 218.

[0081] This driven wheel 210 is configured as an assembly on the driven wheel base 220, and therefore can be easily attached to the carriages 101A, 100B, or can be easily replaced with an existing driven wheel provided on the carriages 101A, 100B.

[0082] Moreover, the bogies 100A and 100B of the embodiment include a bogie body 101, the above-mentioned driven wheels 210 attached to the bogie body 101, and drive wheels 110 attached to the bogie body 101.

[0083] According to the bogies 100A and 100B, the running stability can be improved by applying the driven wheels 210 described above.

[0084] In addition, the control method for the bogies 100A, 100B of the embodiment includes a step of driving the drive wheel 110 and detecting the rotation angle of the driven wheel swivel unit 212, and a step of driving the driven wheel drive mechanism 211 to maintain the rotation angle when the driven wheel swivel unit 212 deviates from the rotation angle.

[0085] According to this control method, the effect of improving running stability by applying the driven wheels 210 described above can be realized. [Explanation of symbols]

[0086] 100A, 100B cart 101 Cart body 110 Drive Wheel 210(210A,210B,210C) Driven wheel 211 Driven wheel drive mechanism 212 Driven wheel turning part 215 Driven wheels 216 Angle detection unit 217 Power disconnection mechanism 218 Driven wheel control device 219 Batteries 220 Driven Wheel Base

Claims

1. A driven wheel base; a driven wheel turning unit provided so as to be infinitely rotatable relative to the driven wheel base; a driven wheel provided on the driven wheel turning portion; an angle detection unit that detects a rotation angle of the driven wheel turning unit; a driven wheel drive mechanism that inputs a rotational force to the driven wheel turning portion; The driven wheels include:

2. Further comprising a power connection / disconnection mechanism that connects or disconnects the input of rotational force from the driven wheel drive mechanism to the driven wheel turning unit. The driven wheel according to claim 1 .

3. a driven wheel control device provided at the driven wheel turning unit, which receives a detection signal from the angle detection unit and outputs a drive signal to the driven wheel drive mechanism; a battery provided in the driven wheel turning unit, for supplying power to the driven wheel drive mechanism, the angle detection unit, and the driven wheel control device; further comprising: The driven wheel according to claim 1 .

4. The carriage body and a driven wheel including a driven wheel slewing unit that is provided to be infinitely rotatable relative to the bogie body, a driven wheel provided on the driven wheel slewing unit, an angle detection unit that detects a rotation angle of the driven wheel slewing unit, and a driven wheel drive mechanism that inputs a rotational force to the driven wheel slewing unit; A drive wheel attached to the bogie body; Including, dolly.

5. The carriage body and a driven wheel including a driven wheel slewing unit that is provided to be infinitely rotatable relative to the bogie body, a driven wheel provided on the driven wheel slewing unit, an angle detection unit that detects a rotation angle of the driven wheel slewing unit, and a driven wheel drive mechanism that inputs a rotational force to the driven wheel slewing unit; A drive wheel provided on the bogie body; A control method for controlling a carriage, comprising: driving the drive wheels and detecting a rotation angle of the driven wheel turning portion; When the driven wheel turning unit deviates from the rotation angle, driving the driven wheel drive mechanism so as to maintain the rotation angle; A method for controlling a carriage, comprising:

Images