JP2021142768A - Unmanned carrier driving device and unmanned carrier with the same - Google Patents

Abstract

To provide a method by which an unmanned carrier is made to travel at a prescribed speed in a prescribed direction even when one of the carrier's driving wheels fails.SOLUTION: Driving devices 11-14 are connected to a vehicle body of an unmanned carrier through common fixing shafts 31-34 and the devices comprise wheels 20A and 20B which have a common center shaft, outer rotor type motors 21A and 21B arranged in inner diameter parts of the wheels 20A and 20B respectively and inverter circuits 22A and 22B driving the outer rotor type motors 21A and 21B respectively. When the inverter circuit 22A or the outer rotor type motor 21A fails, the unmanned carrier is made to travel at a prescribed speed and in a prescribed direction by rotating the wheel 20B using the inverter circuit 22 B and the outer rotor type motor 21B.SELECTED DRAWING: Figure 2

Description

The present invention relates to a drive device for an automatic guided vehicle and an automatic guided vehicle including the drive device, and more particularly to a drive device using an outer rotor type motor and an automatic guided vehicle including the drive device.

As a vehicle driving device using an outer rotor type motor, the driving device described in Patent Document 1 is known. The drive device described in Patent Document 1 directly drives the wheels by arranging an outer rotor type motor on the inner diameter portion of the wheels. However, in Patent Document 1, if a failure occurs in the outer rotor type motor or the inverter circuit that drives the outer rotor type motor, it becomes difficult for the vehicle to travel. However, since Patent Document 1 assumes a general manned electric vehicle, the driver can immediately recognize a failure in the outer rotor type motor or the inverter circuit.

Japanese Unexamined Patent Publication No. 2005-75189 Japanese Patent No. 276605

However, when the vehicle is an automatic guided vehicle, it is difficult for the operator to immediately recognize even if a failure occurs in the outer rotor type motor or the inverter circuit. Therefore, if one of the plurality of drive wheels fails, the automatic guided vehicle may operate unexpectedly.

On the other hand, as a drive device for an automatic guided vehicle, the drive device described in Patent Document 2 is known, but even in the drive device described in Patent Document 2, one of a plurality of drive wheels has a failure. In that case, the automatic guided vehicle may perform unexpected operations.

Therefore, an object of the present invention is to provide a drive device capable of moving an automatic guided vehicle in a predetermined direction at a predetermined speed even if one of the drive wheels fails, and an automatic guided vehicle including the drive device. It is to be.

The drive device according to the present invention is connected to the vehicle body of an unmanned carrier via a common fixing shaft, and is attached to the first and second wheels having a common central axis and the inner diameters of the first and second wheels. The first and second outer rotor type motors arranged respectively and the first and second inverter circuits for driving the first and second outer rotor type motors are provided, respectively, and in the normal operating state, the first And by rotating the second wheel in the same direction and at the same rotation speed, the unmanned carrier is moved in a predetermined direction at a predetermined speed, and the first inverter circuit or the first outer rotor type motor fails. Is characterized in that an unmanned carrier is moved in a predetermined direction at a predetermined speed by rotating a second wheel using a second inverter circuit and a second outer rotor type motor. Further, the automatic guided vehicle according to the present invention is provided with the above-mentioned drive device.

According to the present invention, even if the first inverter circuit or the first outer rotor type motor fails, the automatic guided vehicle can be moved in a predetermined direction at a predetermined speed. It is also possible to rotate the automatic guided vehicle by rotating the first and second wheels in different directions.

The automatic guided vehicle according to the present invention may include a plurality of the above-mentioned drive devices, and the plurality of drive devices may be connected to the vehicle body via different fixing shafts. In this case, the plurality of drive devices include a first drive device in which the first and second wheels form the left front wheel, a second drive device in which the first and second wheels form the right front wheel, and a second drive device. A third drive device in which the first and second wheels form the left rear wheel and a fourth drive device in which the first and second wheels form the right rear wheel may be included.

As described above, according to the present invention, even if one of the driving wheels fails, the automatic guided vehicle can be moved in a predetermined direction at a predetermined speed.

1A and 1B are schematic views showing the configuration of an automatic guided vehicle 1 according to the first embodiment of the present invention, in which FIG. 1A is a xy plan view, FIG. 1B is a yz plan view, and FIG. 1C is an xz plan view. .. FIG. 2 is a schematic diagram for explaining the structure of the drive devices 11 to 14. FIG. 3 is a schematic cross-sectional view for explaining an example of the structure of the outer rotor type motor 21A. FIG. 4 is a schematic xy plan view showing the configuration of the automatic guided vehicle 1A according to the first modification. FIG. 5 is a schematic xy plan view showing the configuration of the automatic guided vehicle 1B according to the second modification. FIG. 6 is a schematic xy plan view showing the configuration of the automatic guided vehicle 1C according to the third modification. FIG. 7 is a schematic xy plan view showing the configuration of the automatic guided vehicle 1D according to the fourth modification. 8A and 8B are schematic views showing the configuration of an automatic guided vehicle 2 according to a second embodiment of the present invention, in which FIG. 8A is a xy plan view, FIG. 8B is a yz plan view, and FIG. 8C is an xz plan view. ..

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1A and 1B are schematic views showing the configuration of an automatic guided vehicle 1 according to the first embodiment of the present invention, in which FIG. 1A is a xy plan view, FIG. 1B is a yz plan view, and FIG. 1C is an xz plan view. ..

As shown in FIG. 1, the automatic guided vehicle 1 according to the present embodiment includes a vehicle body 3 for accommodating a transported object and four drive devices 11 to 14 for moving the vehicle body 3. The drive devices 11 to 14 are connected to the vehicle body 3 via fixing shafts 31 to 34, respectively. The drive devices 11 to 14 constitute the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel, respectively.

FIG. 2 is a schematic diagram for explaining the structure of the drive devices 11 to 14.

The drive devices 11 to 14 are an inverter circuit 22A that drives two wheels 20A and 20B, outer rotor type motors 21A and 21B arranged in the inner diameters of the wheels 20A and 20B, and outer rotor type motors 21A and 21B, respectively. , 22B. Although the central axes of the wheels 20A and 20B are the same, the outer rotor motor 21A and the inverter circuit 22A assigned to the wheels 20A and the outer rotor motor 21B and the inverter circuit 22B assigned to the wheels 20B are independent of each other. And can be controlled independently of each other. Control and power supply to the inverter circuits 22A and 22B are performed from a control device (not shown) provided on the vehicle body 3 via wirings 23A and 23B, respectively.

FIG. 3 is a schematic cross-sectional view for explaining an example of the structure of the outer rotor type motor 21A.

The outer rotor type motor 21A shown in FIG. 3 includes a stator core 40 and a rotor 50 located on the outer periphery thereof. The stator core 40 has a plurality of polar teeth 41 protruding in the radial direction, and a coil 42 is wound around each of the polar teeth 41. In the example shown in FIG. 3, the number of polar teeth 41 is 6, but the number of polar teeth is not limited in the present invention. The rotor 50 includes bow-shaped permanent magnets 51 and 52 whose surfaces facing the stator core 40 are magnetized on the north and south poles, respectively, and a back yoke 53 provided on the outer peripheral side of the permanent magnets 51 and 52. .. Wheels 20A are provided on the outer circumference of the back yoke. With this configuration, if a motor phase current having a predetermined energization pattern is passed through the coil 42, the wheel 20A rotates in conjunction with the rotor 50. The other outer rotor type motor 21B has the same structure.

The above is the structure of the automatic guided vehicle 1 according to the present embodiment. Then, in the normal operating state, the two wheels 20A and 20B constituting the drive devices 11 to 14 are rotated in the same direction and at the same rotation speed. In this case, the two wheels 20A and 20B can be regarded as a single driving wheel. That is, the drive device 11 can be regarded as the left front wheel, the drive device 12 as the right front wheel, the drive device 13 as the left rear wheel, and the drive device 14 as the right rear wheel. Here, the central axes of the drive devices 11 and 12 which are the front wheels may be aligned with each other, and the central axes of the drive devices 13 and 14 which are the rear wheels may be aligned with each other. The distance between the wheels 20A and the wheels 20B in the x direction is preferably less than the diameters of the wheels 20A and 20B. This is because if the wheels 20A and the wheels 20B are separated from each other by the diameters of the wheels 20A and 20B or more, it is difficult to consider them as a single drive wheel. This is because it will be in the same state as when it breaks down, and it will not be fail-safe.

Then, if the rotation speeds of the drive devices 11 to 14 are controlled to be the same as each other, the automatic guided vehicle 1 travels straight in the y direction at a predetermined speed. Further, if the rotation speeds of the drive devices 11 and 13 constituting the left front wheel and the left rear wheel are made larger than the rotation speeds of the drive devices 12 and 14, the automatic guided vehicle 1 makes a right turn operation at a predetermined speed. Further, if the rotation speeds of the drive devices 12 and 14 constituting the right front wheel and the right rear wheel are made larger than the rotation speeds of the drive devices 11 and 13, the automatic guided vehicle 1 makes a left turn operation at a predetermined speed. As described above, in the normal operating state, the drive devices 11 to 14 are driven by the two outer rotor type motors 21A and 21B, respectively, which is about twice as much as the case where only one outer rotor type motor is provided. Driving force and load capacity can be obtained.

The automatic guided vehicle 1 according to the present embodiment defines the vehicle body 3 even when one of the outer rotor type motors 21A and 21B or the inverter circuits 22A and 22B constituting the drive devices 11 to 14 fails. It can be moved at a predetermined speed in the direction of. For example, if the outer rotor type motor 21A or the inverter circuit 22A fails, torque is not applied to the wheels 20A. Even in such a state, the wheels 20B are rotated by the outer rotor type motor 21B and the inverter circuit 22B. be able to. Therefore, when a failure occurs, the automatic guided vehicle 1 does not immediately perform an unexpected operation, and the vehicle body 3 can be moved in a predetermined direction at a predetermined speed while the driving force and the load capacity are reduced. It will be possible. In particular, if the distance between the wheels 20A and the wheels 20B in the x direction is less than the diameters of the wheels 20A and 20B, even if one of the wheels 20A and 20B becomes a non-driving wheel due to a failure, a single driving wheel Since it can be regarded as a state in which the torque of the unmanned vehicle 1 is reduced, the movement of the automatic guided vehicle 1 is unlikely to become unstable.

As described above, in the automatic guided vehicle 1 according to the present embodiment, each of the four drive devices 11 to 14 has a first drive mechanism including wheels 20A, an outer rotor type motor 21A, and an inverter circuit 22A, and wheels 20B. Since it has a second drive mechanism including an outer rotor type motor 21B and an inverter circuit 22B, it is possible to continue the transport operation even if one of the drive mechanisms fails.

Further, when the weight of the transported object mounted on the vehicle body 3 is light, the power consumption may be reduced by cutting off the electric power supplied to one of the inverter circuits 22A and 22B. Such an operation may be automatically performed by providing a sensor for detecting the weight of the transported object on the vehicle body 3.

4 to 7 are schematic xy plan views showing the configurations of the automatic guided vehicles 1A to 1D according to the modified example.

The automatic guided vehicle 1A according to the first modification shown in FIG. 4 is the automatic guided vehicle 1A according to the first embodiment in that the drive device 12 is omitted and the drive device 11 is arranged substantially in the center in the x direction. Is different from. The automatic guided vehicle 1B according to the second modification shown in FIG. 5 is the automatic guided vehicle 1 according to the first embodiment in that the drive device 14 is omitted and the drive device 13 is arranged substantially in the center in the x direction. Is different from. The automatic guided vehicle 1C according to the third modification shown in FIG. 6 is an automatic guided vehicle according to the first embodiment in that the drive device 14 is omitted and the drive devices 11 to 13 are arranged in a row in the x direction. It is different from 1. The automatic guided vehicle 1D according to the fourth modification shown in FIG. 7 is based on the first embodiment in that the drive devices 13 and 14 are omitted and the drive devices 11 and 12 are arranged substantially in the center in the y direction. It is different from the automatic guided vehicle 1.

As illustrated by the automatic guided vehicles 1A to 1D according to these modifications, one of the outer rotor type motors 21A and 21B or one of the inverter circuits 22A and 22B has failed even in the two-wheel configuration or the three-wheel configuration. Even in this case, the vehicle body 3 can be moved in a predetermined direction at a predetermined speed by the normal wheels 20A or 20B.

8A and 8B are schematic views showing the configuration of an automatic guided vehicle 2 according to a second embodiment of the present invention, in which FIG. 8A is a xy plan view, FIG. 8B is a yz plan view, and FIG. 8C is an xz plan view. ..

The automatic guided vehicle 2 according to the present embodiment is different from the automatic guided vehicle 1 according to the first embodiment in that it includes a single drive device 15. The configuration of the drive device 15 is as shown in FIG. 2, and is connected to the vehicle body 3 via the fixing shaft 35. Further, if the support of the vehicle body 3 becomes unstable only with the drive device 15, one or two or more non-drive wheels may be added. Here, when the automatic guided vehicle 2 according to the present embodiment travels straight, the two wheels 20A and 20B constituting the drive device 15 are rotated in the same direction and at the same rotation speed. On the other hand, if the wheels 20A and 20B are rotated in different directions, the automatic guided vehicle 2 rotates on the spot.

If one of the outer rotor type motors 21A and 21B or one of the inverter circuits 22A and 22B that constitute the drive device 15 fails, the other of the outer rotor type motors 21A and 21B and the inverter circuits 22A and 22B The other can be used to drive the automatic guided vehicle 2 straight.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention, and these are also the present invention. Needless to say, it is included in the range.

1,1A-1D, 2 Automated guided vehicle 3 Body 11-15 Drive device 20A, 20B Wheels 21A, 21B Outer rotor type motor 22A, 22B Inverter circuit 23A, 23B Wiring 31-35 Fixing shaft 40 Stator core 41 Polar teeth 42 coil 50 Rotor 51, 52 Permanent magnet 53 Back yoke

Claims (5)

The first and second wheels, which are connected to the body of an automated guided vehicle via a common fixing shaft and have a common central axis,
The first and second outer rotor type motors arranged in the inner diameters of the first and second wheels, respectively,
The first and second inverter circuits for driving the first and second outer rotor type motors, respectively, are provided.
In the normal operating state, the unmanned carrier is moved in a predetermined direction at a predetermined speed by rotating the first and second wheels in the same direction and at the same rotation speed, and the first inverter circuit or the said. In a state where the first outer rotor type motor has failed, the unmanned transport vehicle is designated by rotating the second wheel using the second inverter circuit and the second outer rotor type motor. A drive device for an unmanned carrier, characterized in that it moves in a direction at a predetermined speed. The driving device for an automatic guided vehicle according to claim 1, wherein the automatic guided vehicle is rotated by rotating the first and second wheels in different directions. An automatic guided vehicle provided with the drive device according to claim 1 or 2. An automatic guided vehicle including a plurality of automatic guided vehicles according to claim 1, wherein the plurality of automatic guided vehicles are connected to the vehicle body via different fixing shafts. The plurality of drive devices include a first drive device in which the first and second wheels form a left front wheel, a second drive device in which the first and second wheels form a right front wheel, and the above. A claim comprising a third drive device in which the first and second wheels form the left rear wheel, and a fourth drive device in which the first and second wheels form the right rear wheel. Item 4. The automatic guided vehicle according to item 4.

Images