Truck, and transport system

Abstract

To stably stop a truck at a desired place.SOLUTION: A truck is constituted so as to be transported by a transport vehicle. The truck comprises a truck body, a plurality of wheels, and a braking device. Each of the wheels is attached to the truck body. The braking device is constituted so as to brake rotation of at least one of the wheels. The braking device comprises an armature, and an electromagnet or a permanent electromagnet. The armature is arranged so as to be movable in a rotation axis direction of the wheels. The electromagnet or the permanent electromagnet is constituted so as to move the armature in the axis direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a carriage and a transport system.

Background Art

[0002] In recent years, a transport system has been proposed in which a carriage is transported by a powered transport vehicle such as an automated guided vehicle (AGV) and an autonomous mobile robot (AMR). For example, Patent Document 1 discloses a transport system in which an automated guided vehicle pulls a carriage.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the transport system as described above, for example, there is a demand that an automated guided vehicle transports a carriage into an elevator and only the carriage is raised or lowered by the elevator. When separated from an automated guided vehicle or the like and only the carriage remains, it is preferable to stably stop the carriage at that location.

[0005] An object of the present invention is to stably stop a carriage at a desired location.

Means for Solving the Problems

[0006] The carriage according to the first aspect is configured to be transported by a transport vehicle. The carriage includes a carriage body, a plurality of wheels, and a braking device. Each wheel is attached to the carriage body. The braking device is configured to brake the rotation of at least one wheel. The braking device has an armature and an electromagnet or a permanent magnet. The armature is arranged to be movable in the rotational axis direction of the wheel. The electromagnet or the permanent magnet is configured to move the armature in the axial direction.

[0007] According to this configuration, since the carriage has a braking device for braking the rotation of the wheels, the carriage can be stably stopped at a desired location by operating the braking device.

[0008] The carriage according to the second aspect is configured as follows in the carriage according to the first aspect. The plurality of wheels include free wheels and fixed wheels. The braking device is configured to brake the rotation of the fixed wheels.

[0009] The carriage according to the third aspect is configured as follows in the carriage according to the first or second aspect. The plurality of wheels include front wheels, rear wheels, and intermediate wheels. The front wheels are arranged on the transport vehicle side of the carriage body. The rear wheels are arranged on the side opposite to the transport vehicle side of the carriage body. The intermediate wheels are arranged between the front wheels and the rear wheels. The braking device is configured to brake the rotation of at least one of the intermediate wheels and the rear wheels.

[0010] The carriage according to the fourth aspect is configured as follows in the carriage according to any one of the first to third aspects. The plurality of wheels include front wheels and rear wheels. The front wheels are arranged on the transport vehicle side of the carriage body. The rear wheels are arranged on the side opposite to the transport vehicle side of the carriage body. The braking device is configured to brake the rotation of the rear wheels.

[0011] The carriage according to the fifth aspect further includes a sensor in the carriage according to any one of the first to fourth aspects. The sensor detects the braking state of the braking device.

[0012] The carriage according to the sixth aspect is configured as follows in the carriage according to any one of the first to fifth aspects. The braking device has a permanent magnet.

[0013] The carriage according to the seventh aspect is configured as follows in the carriage according to any one of the first to sixth aspects. The braking device is configured to be powered from the carrier vehicle.

[0014] The carriage according to the eighth aspect is configured as follows in the carriage according to any one of the first to seventh aspects. The braking device is configured to be powered from the carrier vehicle by wireless power supply.

[0015] The conveying system according to the ninth aspect includes a carriage according to any one of the first to eighth aspects and a carrier vehicle. The carrier vehicle has a prime mover. The carrier vehicle is connected to the carriage.

[0016] The conveying system according to the tenth aspect is configured as follows in the conveying system according to the ninth aspect. The carrier vehicle has a coupling mechanism and a control unit. The coupling mechanism is configured to detachably connect the carrier vehicle to the carriage. The control unit controls the coupling mechanism. The carriage has a sensor. The sensor detects the braking state of the braking device. When the control unit determines that the braking device is in the braking state based on the braking state detected by the sensor, the control unit releases the connection between the carrier vehicle and the carriage by the coupling mechanism.

Advantages of the Invention

[0017] According to the present invention, the carriage can be stably stopped at a desired location.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0019] Hereinafter, the cart 102 and the transport system 100 according to the present embodiment will be described with reference to the drawings. In the following description, the front refers to the direction in which the driverless transport vehicle 101 pulls the cart 102 forward, and the rear refers to the direction in which the driverless transport vehicle 101 pushes the cart 102 forward. That is, the left side of FIG. 1 is the front, and the right side of FIG. 1 is the rear.

[0020] <Transport System> As shown in FIGS. 1 and 2, the transport system 100 has a driverless transport vehicle 101 and a cart 102. The transport system 100 is configured to transport goods in a factory or a warehouse.

[0021] <Driverless Transport Vehicle> The driverless transport vehicle 101 can travel forward to pull the cart 102 or travel backward to push the cart 102. The driverless transport vehicle 101 is configured to be able to move forward and backward. The driverless transport vehicle 101 has a vehicle body 101a, a pair of driven wheels 101b, a pair of drive wheels 101c, a pair of electric motors 101d (an example of a prime mover), a battery 101e, a power supply unit 101f, and a control unit 101g.

[0022] The driven wheels 101b and the drive wheels 101c are attached to the bottom surface of the vehicle body 101a. In this embodiment, a pair of driven wheels 101b serve as the front wheels, and a pair of drive wheels 101c serve as the rear wheels. Note that a pair of driven wheels 101b may serve as the rear wheels, a pair of drive wheels 101c may serve as the front wheels, or all the wheels may be drive wheels 101c. The driven wheels 101b are attached to the vehicle body 101a so as to be rotatable. That is, the front wheels are freely rotatable wheels. For example, the driven wheels 101b are swivel casters or ball casters.

[0023] The electric motor 101d is configured to drive the drive wheels 101c. When the electric motor 101d rotates forward, the traveling body moves forward, and when the electric motor 101d rotates reversely, the automated guided vehicle 101 moves backward. One of the pair of electric motors 101d drives the right drive wheel 101c, and the other electric motor 101d drives the left drive wheel 101c.

[0024] The battery 101e is configured to supply power to the electric motor 101d. Further, the battery 101e is configured to supply power to a braking device 4 described later.

[0025] The power supply unit 101f is configured to supply power from the battery 101e to the braking device 4 of the carriage 102. Specifically, the power supply unit 101f performs wireless power supply to the braking device 4 via a power receiving unit 102e of the carriage 102 described later.

[0026] The coupling mechanism 101h is configured to couple the automated guided vehicle 101 to the carriage 102 or to release the coupling. The coupling mechanism 101h is controlled by a control unit 101g. For example, the coupling mechanism 101h has a pin 101i that can move forward and backward. The pin 101i is configured to enter and exit from a through hole provided in the carriage 102.

[0027] The control unit 101g is configured to control the braking device 4 of the carriage 102. Specifically, the control unit 101g is configured to control the braking device 4 by supplying power from the battery 101e to the braking device 4 via the power supply unit 101f and the power receiving unit 102e. Further, the control unit 101g is configured to control the electric motor 101d by controlling the power supplied to the electric motor 101d.

[0028] Also, the control unit 101g is configured to control the coupling mechanism 101h. Specifically, the control unit 101g is configured to control the forward and backward movement of the pin 101i of the coupling mechanism 101h.

[0029] The control unit 101g is constituted by, for example, a computer (such as a microcomputer) including a CPU (Central Processing Unit) and a ROM (Read Only Memory). Programs for performing various operations are stored in the ROM. The CPU executes the programs stored in the ROM.

[0030] <Carriage> The carriage 102 is configured to be towed by the automated guided vehicle 101. The carriage 102 is disposed behind the automated guided vehicle 101. The carriage 102 is connected to the automated guided vehicle 101 by a coupling mechanism 101h.

[0031] The carriage 102 has a carriage body 102a, a plurality of wheels 102b, 102c, a pair of braking devices 4, a pair of sensors 102d, and a power receiving unit 102e. The carriage 102 does not have a prime mover.

[0032] The cart body 102a is configured to be able to load luggage thereon. A plurality of wheels 102b, 102c are attached to the cart body 102a. The plurality of wheels 102b, 102c includes a pair of front wheels 102b and a pair of rear wheels 102c. The front wheels 102b are arranged on the side of the unmanned carrier 101 of the cart body 102a, and the rear wheels 102c are attached to the side of the cart body 102a opposite to the side of the unmanned carrier 101. That is, the front wheels 102b are attached to the front part of the cart body 102a, and the rear wheels 102c are attached to the rear part of the cart body 102a.

[0033] The front wheels 102b and the rear wheels 102c are attached to the bottom surface of the cart body 102a. The front wheels 102b are attached to the cart body 102a so as to be rotatable. That is, the front wheels 102b are free wheels. For example, the front wheels 102b are swivel casters, ball casters, or the like.

[0034] The rear wheels 102c are attached to the cart body 102a so as not to be rotatable. That is, the rear wheels 102c are fixed wheels. For example, the rear wheels 102c are fixed casters or the like.

[0035] The braking device 4 is configured to brake the rotation of the rear wheels 102c. That is, the braking device 4 is configured to brake the rotation of the fixed wheels. The braking device 4 is supplied with power from the battery 101e of the unmanned carrier 101. Specifically, the braking device 4 is supplied with power from the battery 101e by wireless power supply via the power supply unit 101f and the power receiving unit 102e.

[0036] Figure 3 is a cross-sectional view of the braking device 4. In FIG. 3, the symbol O indicates the rotation axis of the rear wheel 102c. In the following description, the axial direction is the direction in which the rotation axis O of the rear wheel 102c extends. The circumference is the circumference of a circle centered on the rotation axis O, and the diameter is the diameter of a circle centered on the rotation axis O.

[0037] As shown in FIG. 3, the braking device 4 includes an armature 41, a friction disk 42, a plurality of permanent magnets 43, a support member 44, side plates 45, a plurality of biasing members 46, and a plurality of collars 47.

[0038] The armature 41 is arranged to be axially movable. Specifically, the armature 41 moves toward the friction disk 42 or moves away from the friction disk 42. The armature 41 is arranged to be non-rotatable. Specifically, the armature 41 is arranged to be non-rotatable with respect to the support member 44. The armature 41 is arranged axially between the friction disk 42 and the permanent magnets 43.

[0039] The armature 41 is made of a magnetic material. Specifically, the armature 41 is made of steel. More specifically, the armature 41 is made of carbon steel for machine structures (e.g., S45C), hot-rolled steel for general structures (e.g., SS400), or cold-rolled steel (e.g., SPCC), etc.

[0040] The friction disk 42 is disk-shaped. The friction disk 42 is arranged to be rotatable. That is, the friction disk 42 is arranged to be relatively rotatable with respect to the armature 41. The friction disk 42 is configured to rotate together with the rear wheel 102c to be braked. The friction disk 42 faces the armature 41 axially.

[0041] The friction disk 42 is made of a non-magnetic material. Specifically, the friction disk 42 is made of stainless steel. More specifically, the friction disk 42 is made of austenitic stainless steel (e.g., SUS303, SUS304, SUS316), etc.

[0042] The friction disk 42 has a boss portion 421 and a disk main body portion 422. The boss portion 421 is cylindrical. For example, a shaft (not shown) that rotates integrally with the rear wheel 102c fits into the boss portion 421 and rotates integrally with the boss portion 421 by a key and a keyway.

[0043] The disk main body portion 422 is disposed radially outside the boss portion 421. The disk main body portion 422 is attached to the boss portion 421 so as to be axially movable. Specifically, the boss portion 421 is spline-fitted to the disk main body portion 422. Therefore, the disk main body portion 422 rotates integrally with the boss portion 421. Also, the disk main body portion 422 is axially movable with respect to the boss portion 421.

[0044] FIG. 4 is a side view of the braking device 4 with the armature 41, the friction disk 42, and the side plate 45 removed. As shown in FIGS. 3 and 4, the support member 44 supports the permanent magnet 43. Specifically, the support member 44 has a plurality of first accommodation recesses 441 and a plurality of second accommodation recesses 442. The support member 44 supports the permanent magnet 43 by accommodating the permanent magnet 43 in the first accommodation recess 441. Also, the support member 44 supports the biasing member 46 by accommodating the biasing member 46 in the second accommodation recess 442.

[0045] The first accommodation recesses 441 are arranged at intervals in the circumferential direction. The second accommodation recess 442 is arranged between a pair of adjacent first accommodation recesses 441 in the circumferential direction. In the present embodiment, the plurality of first accommodation recesses 441 and the plurality of second accommodation recesses 442 are alternately arranged in the circumferential direction.

[0046] The first accommodation recess 441 opens axially toward the armature 41. Also, the first accommodation recess 441 opens radially inward. The second accommodation recess 442 opens axially toward the armature 41.

[0047] The support member 44 is fixed to the carriage body 102a. The support member 44 is fixed to the carriage body 102a by bolts 49 or the like. Therefore, the support member 44 is non-rotatable. Also, the support member 44 is non-movable in the axial direction.

[0048] The support member 44 is made of a non-magnetic material. For example, the support member 44 is made of stainless steel, aluminum, or an aluminum alloy.

[0049] As shown in FIG. 3, the side plate 45 is arranged at an interval from the support member 44 in the axial direction. The armature 41 and the friction disk 42 are arranged between the side plate 45 and the support member 44 in the axial direction.

[0050] The side plate 45 is disk-shaped. The side plate 45 is fixed to the support member 44. For example, the side plate 45 is fixed to the support member 44 by a plurality of bolts 48. Therefore, the side plate 45 is non-rotatable relative to the support member 44 and non-movable in the axial direction.

[0051] The side plate 45 is made of a magnetic material. Specifically, the side plate 45 is made of steel. More specifically, the side plate 45 is made of carbon steel for machine structures (e.g., S45C), hot-rolled steel for general structures (e.g., SS400), or cold-rolled steel (e.g., SPCC). Note that the side plate 45 may be made of a non-magnetic material. In this case, the side plate 45 can be made of stainless steel. Specifically, the friction disk 42 can be made of austenitic stainless steel (e.g., SUS303, SUS304, SUS316).

[0052] Color 47 is arranged axially between side plate 45 and support member 44. Color 47 is cylindrical. Bolt 48 extends through color 47. This color 47 maintains the spacing between side plate 45 and support member 44. Also, color 47 is arranged within notch 411 of armature 41. For this reason, armature 41 is in interference with color 47 and cannot rotate.

[0053] As shown in FIGS. 3 and 4, biasing member 46 biases armature 41 axially toward friction disk 42. Biasing member 46 is, for example, a coil spring. Biasing member 46 is arranged axially between a pair of adjacent permanent magnets 43. Specifically, biasing member 46 is arranged within second receiving recess 442 of support member 44. A part of biasing member 46 protrudes from second receiving recess 442 toward armature 41.

[0054] Biasing member 46 is arranged radially inward with respect to bolt 48 for fixing side plate 45 and bolt 49 for fixing support member 44. In a radial view, biasing member 46 overlaps bolt 48 or bolt 49.

[0055] Biasing member 46 is preferably composed of a magnetic material. Note that biasing member 46 may be composed of a non-magnetic material.

[0056] Permanent magnet 43 is configured to move armature 41 axially when power from battery 101e is supplied. Permanent magnet 43 switches between an adsorbed state and a non-adsorbed state. That is, by applying a signal from the outside, permanent magnet 43 can be made to enter the adsorbed state or the non-adsorbed state. Permanent magnet 43 is configured to adsorb armature 41 and move it axially when it enters the adsorbed state. In the present embodiment, permanent magnet 43 moves armature 41 away from friction disk 42 axially.

[0057] Each permanent magnet 43 is arranged in the circumferential direction. The permanent magnet 43 is disposed within the first receiving recess 441 of the support member 44.

[0058] The permanent magnet 43 has a first magnet 431, a second magnet 432, a pair of yokes 433, and a coil 434. The pair of yokes 433 are arranged at intervals from each other. Specifically, the pair of yokes 433 are arranged at intervals from each other in the circumferential direction. Each yoke 433 is plate-shaped. Each yoke 433 is arranged so as to face the circumferential direction.

[0059] The yoke 433 projects from the support member 44 toward the armature 41 in the axial direction. Although not particularly limited, the amount of projection of the yoke 433 from the support member 44 is, for example, about 0.1 to 0.2 mm. Note that the yoke 433 may not project from the support member 44 and may be flush with the support member 44.

[0060] The yoke 433 projects radially inward from the first receiving recess 441. Although not particularly limited, the amount of projection of the yoke 433 from the first receiving recess 441 is, for example, about 2 to 3 mm. Note that the yoke 433 may not project radially inward from the first receiving recess 441.

[0061] The yoke 433 is made of a magnetic material. The yoke 433 is made of, for example, steel. More specifically, the yoke 433 is made of carbon steel for machine structural use (for example, S45C, S50C), or hot-rolled steel for general structure use (for example, SS400), etc.

[0062] The first magnet 431 is disposed between the pair of yokes 433. The first magnet 431 is in contact with each yoke 433. The first magnet 431 has a higher coercive force than the second magnet 432. The first magnet 431 is configured not to reverse magnetization even when a pulse current is passed through the coil 434. The first magnet 431 is, for example, a neodymium magnet, or a samarium cobalt magnet, etc.

[0063] The first magnet 431 has a magnetization direction along the circumferential direction. That is, the magnetization direction of the first magnet 431 is from one yoke 433 to the other yoke 433 of the pair of yokes 433. In a pair of adjacent permanent magnets 43, each first magnet 431 is arranged such that the magnetization directions are different from each other. For example, in one first magnet 431, the pole on the side closer to the other first magnet 431 is the N pole, and in the other first magnet 431, the pole on the side closer to the one first magnet 431 is the N pole. By arranging them in this way, it is possible to suppress the flow of magnetic flux between a pair of adjacent permanent magnets 43.

[0064] The second magnet 432 is arranged between the pair of yokes 433. The second magnet 432 is in contact with each yoke 433. The second magnet 432 has a coercive force weaker than that of the first magnet 431. The second magnet 432 is configured to reverse magnetization by passing a pulsed current through the coil 434. The second magnet 432 is, for example, an alnico magnet or the like.

[0065] The first magnet 431 and the second magnet 432 are arranged in the radial direction. In the present embodiment, the first magnet 431 is arranged radially inside the second magnet 432. Note that the first magnet 431 may be arranged radially outside the second magnet 432.

[0066] The coil 434 is wound around the first magnet 431 and the second magnet 432. Note that the coil 434 may be wound only around the second magnet 432 and not around the first magnet 431. The coil 434 is arranged between the pair of yokes 433.

[0067] The coil 434 is completely accommodated within the first accommodation recess 441 in the axial direction. On the other hand, in the radial direction, the coil 434 protrudes radially inward from the first accommodation recess 441. Note that the coil 434 may be completely accommodated within the first accommodation recess 441 in the radial direction.

[0068] Coil 434 is connected to the power receiving unit 102e. Specifically, coil 434 is connected to the battery 101e via the power receiving unit 102e and the power feeding unit 101f. Coil 434 is configured to magnetize and reverse the second magnet 432 by passing a pulsed current through it. Note that even if a pulsed current is passed through coil 434, the first magnet 431 will not magnetize and reverse.

[0069] <Sensor> As shown in FIGS. 1 and 2, the sensor 102d is configured to detect the braking state of the braking device 4. Specifically, the sensor 102d is provided on any one of the yokes 433. The sensor 102d detects whether the braking device 4 is in a state of braking the rotation of the rear wheel 102c by detecting the magnetic flux density of the magnetic flux leaking from the yoke 433. The sensor 102d is, for example, a Hall sensor. The sensor 102d outputs the detection result to the control unit 101g. Based on the detection result of the sensor 102d, when the control unit 101g determines that the magnetic flux density leaking from the yoke 433 is less than a predetermined value, it determines that the permanent magnet 43 is in an adsorbed state, that is, the braking device 4 is not in a braking state. On the other hand, based on the detection result of the sensor 102d, when the control unit 101g determines that the magnetic flux density leaking from the yoke 433 is equal to or greater than a predetermined value, it determines that the permanent magnet 43 is in a non-adsorbed state, that is, the braking device 4 is in a braking state.

[0070] <Power receiving unit> The power receiving unit 102e is configured to receive power supplied from the outside. Specifically, the power receiving unit 102e is configured to receive the power supplied from the power feeding unit 101f. The power receiving unit 102e is configured to receive power wirelessly from the power feeding unit 101f. The power receiving unit 102e is configured to supply the received power to the braking device 4.

[0071] <Operation> The braking device 4 of the carriage 102 configured as described above operates as follows. First, in the permanent magnet 43, when the magnetization direction of the first magnet 431 is different from the magnetization direction of the second magnet 432, a magnetic circuit is formed among the pair of yokes 433, the first magnet 431, and the second magnet 432. Therefore, the permanent magnet 43 is in a non-adsorbed state.

[0072] When the permanent magnet 43 is in the non-adsorbed state, the armature 41 is pressed against the friction disk 42 by the biasing force of the biasing member 46. As a result, the friction disk 42 is sandwiched between the armature 41 and the side plate 45, and rotation is stopped. As a result, the braking device 4 brakes the rotation of the rear wheel 102c.

[0073] Next, power is supplied to the braking device 4 from the battery 101e via the power supply unit 101f and the power receiving unit 102e, and a pulse current is passed through the coil 434 of the permanent magnet 43 to reverse the magnetization of the second magnet 432. By making the magnetization direction of the second magnet 432 the same as the magnetization direction of the first magnet 431 in this way, the permanent magnet 43 becomes in an adsorbed state. That is, a magnetic circuit is formed among the pair of yokes 433, the first magnet 431, the second magnet 432, and the armature 41. As a result, the armature 41 moves axially away from the friction disk 42 against the biasing force of the biasing member 46. Since the clamping of the friction disk 42 by the armature 41 and the side plate 45 is released, the friction disk 42 becomes in a rotatable state. As a result, the braking of the rotation of the rear wheel 102c by the braking device 4 is released. Note that after reversing the magnetization of the second magnet 432, it is not necessary to pass a current through the coil 434. That is, while the armature 41 is adsorbed by the permanent magnet 43, no power is consumed.

[0074] Next, power is supplied from the battery 101e to the braking device 4 via the power supply unit 101f and the power receiving unit 102e, and a pulse current is passed through the coil 434 of the permanent magnet 43 in the direction opposite to the above, thereby magnetically inverting the second magnet 432. In this way, by making the magnetization direction of the second magnet 432 opposite to the magnetization direction of the first magnet 431, the permanent magnet 43 enters a non-adsorbing state. That is, a magnetic circuit is formed within the first magnet 431, the second magnet 432, and the pair of yokes 433, and no magnetic flux flows into the armature 41. Since the armature 41 is not adsorbed by the permanent magnet 43, it moves toward the friction disk 42 by the biasing force of the biasing member 46. As a result, the friction disk 42 is sandwiched between the armature 41 and the side plate 45 and becomes non-rotatable. As a result, the braking device 4 brakes the rotation of the rear wheel 102c. Also in this case, after magnetically inverting the second magnet 432, there is no need to pass a current through the coil 434.

[0075] <Control method> FIG. 5 is a flowchart showing an example of the control method of the control unit 101g. Hereinafter, the control method of the control unit 101g will be described with reference to FIG. 5.

[0076] The control unit 101g determines whether or not the carriage 102 is placed at a desired location (step S1). For example, the control unit 101g determines whether or not the carriage 102 is placed at a desired location from a QR code (registered trademark) attached to the floor, GPS information, etc. Note that information about the desired location is input to the control unit 101g by the user, for example.

[0077] When the control unit 101g determines that the carriage 102 is placed at a desired location, it executes a braking process (step S2). That is, the control unit 101g supplies power to the braking device 4 and sets the braking device 4 in a braking state. Thereby, the rotation of the rear wheel 102c of the carriage 102 is braked.

[0078] Next, the control unit 101g determines whether the braking device 4 is in a braking state based on the information from the sensor 102d (step S3). If the control unit 101g determines that the braking device 4 is not in a braking state (No in step S3), the braking process is executed again (step S2).

[0079] If the control unit 101g determines that the braking device 4 is in a braking state (Yes in step S3), the control unit 101g controls the coupling mechanism 101h to release the connection between the driverless transport vehicle 101 and the carriage 102 (step S4). Thereby, the carriage 102 is arranged at a desired location with the rotation of the rear wheels 102c being braked.

[0080] [Modification Example] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to these, and various modifications are possible without departing from the spirit of the present invention. Note that the following modification examples can basically be applied simultaneously.

[0081] (a) In the above embodiment, the braking device 4 was configured to separate the armature 41 from the friction disk 42 by adsorbing the armature 41 with the permanent magnet 43. However, the configuration of the braking device 4 is not limited to this.

[0082] For example, as shown in FIG. 6, the braking device 4 may be configured to press the armature 41 against the friction disk 42 by adsorbing the armature 41 with the permanent magnet 43. Hereinafter, this modification example will be described in detail. Note that the description of the configuration substantially the same as that in the above embodiment will be omitted.

[0083] The armature 41 is rotatably arranged. A rotating member 401 that rotates integrally with the rear wheel 102c is attached to the armature 41. The armature 41 rotates integrally with the rotating member 401. The biasing member 46 is arranged between the armature 41 and the rotating member 401. The biasing member 46 is attached to the armature 41 and the rotating member 401. For example, the biasing member 46 is a leaf spring or the like.

[0084] The friction disk 42 is disposed non-rotatably. Specifically, the friction disk 42 is fixed to the support member 44. For example, the friction disk 42 is fixed to the support member 44 by bolts or the like. Note that the friction disk 42 may be integrally formed with the support member 44 by one member.

[0085] The armature 41 is disposed between the rotating member 401 and the friction disk 42 in the axial direction. The friction disk 42 is disposed between the armature 41 and the permanent magnet 43 in the axial direction.

[0086] FIG. 7 is a side view of the braking device 4 with the rotating member 401, the biasing member 46, and the armature 41 removed. As shown in FIG. 7, the friction disk 42 has a plurality of through holes 423 extending in the axial direction.

[0087] A pair of yokes 433 of the permanent magnet 43 extend within the through holes 423 of the friction disk 42. The tip surface (the upper end surface in FIG. 6) of each yoke 433 is exposed toward the armature 41 through the through hole 423.

[0088] A non-magnetic friction material 424 is attached to the upper surface of the friction disk 42 (the surface facing the armature 41). For example, the non-magnetic friction material 424 is attached to the friction disk 42 by an adhesive or the like. The non-magnetic friction material 424 is a friction material having no magnetism.

[0089] A magnetic friction material 425 is attached to the tip surface of the yoke 433 (the surface facing the armature 41). For example, the magnetic friction material 425 is attached to the yoke 433 by an adhesive or the like. The magnetic friction material 425 is a friction material having magnetism.

[0090] In the brake device 4 configured as described above, when the permanent magnet 43 is in a non-adsorbed state, the armature 41 is separated from the friction disk 42 by the biasing force of the biasing member 46, so the armature 41 is rotatable. On the other hand, when the permanent magnet 43 is in an adsorbed state, the armature 41 is pressed against the friction disk 42 and thus becomes non-rotatable. As a result, the brake device 4 brakes the rotation of the rear wheel 102c. Also in this case, after reversing the magnetization of the second magnet 432, there is no need to flow a current through the coil 434. That is, while the armature 41 is adsorbed by the permanent magnet 43, no power is consumed.

[0091] Based on the detection result of the sensor 102d, when the control unit 101g determines that the magnetic flux density leaking from the yoke 433 is less than a predetermined value, it determines that the permanent magnet 43 is in an adsorbed state, that is, the brake device 4 is in a braking state. On the other hand, based on the detection result of the sensor 102d, when the control unit 101g determines that the magnetic flux density leaking from the yoke 433 is greater than or equal to a predetermined value, it determines that the permanent magnet 43 is in a non-adsorbed state, that is, the brake device 4 is not in a braking state.

[0092] (b) In the above embodiment, the brake device 4 is configured using the permanent magnet 43, but the configuration of the brake device 4 is not limited to this. For example, the brake device 4 may be an electromagnetic brake. In this case, the brake device 4 has an electromagnet instead of the permanent magnet 43. The electromagnet receives power from the battery 101e via the power receiving unit 102e and the power supply unit 101f. Also, when using an electromagnetic brake as the brake device 4, it is preferable to use a non-excitation operation type electromagnetic brake. When using an excitation operation type electromagnetic brake as the brake device 4, it is preferable that the carriage 102 has a battery.

[0093] (c) In the above embodiment, the power of the brake device 4 is supplied from the battery of the automated guided vehicle 101, but the configuration of the brake device 4 is not limited to this. For example, the carriage 102 may have a battery attached to the carriage body 102a. And the power of the brake device 4 may be supplied from the battery attached to the carriage body 102a.

[0094] (d) In the above embodiment, the automated guided vehicle 101 is disposed in front of the dolly 102, but the configuration of the conveyance system 100 is not limited to this. For example, the conveyance system 100 may be configured to convey the dolly 102 in a state in which the automated guided vehicle 101 is positioned below the dolly 102.

[0095] (e) In the above embodiment, power is supplied from the power supply unit 101f to the power receiving unit 102e by wireless power supply. However, power may be supplied from the power supply unit 101f to the power receiving unit 102e by wired power supply.

[0096] (f) Although an automated guided vehicle 101 has been exemplified as a guided vehicle, the guided vehicle is not limited to the automated guided vehicle 101. For example, the guided vehicle may be an autonomous mobile robot (AMR).

[0097] (g) As shown in Fig. 8, the bogie 102 may have an intermediate wheel 102f in addition to the front wheel 102b and the rear wheel 102c. The intermediate wheel 102f is disposed between the front wheel 102b and the rear wheel 102c. In this case, the brake device 4 is configured to brake the rotation of the intermediate wheel 102f. Note that the brake device 4 may brake the rotation of the rear wheel 102c instead of the intermediate wheel 102f, or may be provided on each of the intermediate wheel 102f and the rear wheel 102c to brake the rotation of both the intermediate wheel 102f and the rear wheel 102c. [Explanation of symbols]

[0098] 4: Braking device 41:Armature 43: Permanent electromagnet 100:Transportation system 101:Automated guided vehicle 101g: Control section 101h: Connection mechanism 102: Cart 102a: Cart body 102b: Front wheel 102c: Rear wheel 102d: Sensor 102f: Intermediate wheel O: Rotation axis

Claims

1. A trolley configured to be transported by a transport vehicle, comprising: a trolley body; a plurality of wheels attached to the trolley body; a braking device configured to brake the rotation of at least one of the wheels; and the braking device includes an armature movably disposed in the axial direction of the rotation axis of the wheel; an electromagnet or a permanent magnet configured to move the armature in the axial direction; and a trolley.

2. The plurality of wheels include a swivel wheel and a fixed wheel, and the braking device is configured to brake the rotation of the fixed wheel. The trolley according to claim 1.

3. The plurality of wheels include a front wheel disposed on the transport vehicle side of the trolley body, a rear wheel disposed on the side of the trolley body opposite to the transport vehicle side, and an intermediate wheel disposed between the front wheel and the rear wheel, and the braking device is configured to brake the rotation of at least one of the intermediate wheel and the rear wheel. The trolley according to claim 1.

4. The plurality of wheels include a front wheel disposed on the transport vehicle side of the trolley body and a rear wheel disposed on the side of the trolley body opposite to the transport vehicle side, and the braking device is configured to brake the rotation of the rear wheel. The trolley according to claim 1.

5. The trolley further includes a sensor configured to detect the braking state of the braking device. The trolley according to claim 1.

6. The braking device has the permanent magnet. The trolley according to claim 1.

7. The braking device is configured to be powered from the transport vehicle. The trolley according to claim 1.

8. The braking device is configured to be powered from the transport vehicle by wireless power supply. The trolley according to claim 1.

9. A transport system comprising the trolley according to any one of claims 1 to 8, and a transport vehicle having a prime mover and connected to the trolley.

10. The transport vehicle includes a coupling mechanism configured to removably couple the transport vehicle to the trolley and a control unit configured to control the coupling mechanism, the trolley has a sensor configured to detect the braking state of the braking device, and when the control unit determines that the braking device is in a braking state based on the braking state detected by the sensor, the control unit releases the coupling between the transport vehicle and the trolley by the coupling mechanism. The transport system according to claim 9.

Images