Power supply system and power supply method for transport vehicles

Abstract

To provide a power supply system and a power supply method of a transport vehicle capable of performing a stable contactless power supply to the transport vehicle without being affected by foreign matters or the like.SOLUTION: A power supply system for a transport vehicle that supplies power to the transport vehicle in a contactless manner includes: a power supply unit that is installed in an upright position for a horizontal surface and supplies power to the transport vehicle; and a power receiving unit that is provided to the transport vehicle when it is in the upright position for the horizontal surface and performs reception of power from the power supply unit when it is in a position facing the power supply unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power supply system and a power supply method for a transport vehicle that supply power to the transport vehicle in a non-contact manner. [Background technology]

[0002] At work sites such as factories, transport carts that run on tracks such as rails are used to transport intermediate and final products. For example, transport carts that transport steel materials and coils at steelworks run on tracks laid within the steelworks to transport steel materials between factories or within the factory. Electricity is often supplied to the transport carts by contact-type power supply (hereinafter also referred to as "contact power supply") using contact wires and pantographs (current collectors).

[0003] In contact power supply using a trolley wire, problems with the running of the transport cart can occur due to wear of the trolley wire or current collector, sparks caused by disconnection of the contact part, etc. Even if preventive maintenance such as regular inspection of the transport cart and trolley wire and regular replacement of parts is carried out, it is difficult to completely prevent running problems of the transport cart.

[0004] In response to this, development is underway of wireless power transmission technology (hereinafter also referred to as "wireless power supply") that supplies power to vehicles such as electric vehicles in a wireless manner. As wireless power transmission technology, methods such as an electromagnetic induction method, a magnetic resonance method, and an electric field coupling method have been proposed.

[0005] In wireless power transmission technology, when supplying power, a power supply unit having a power supply coil, a power supply electrode, etc. and a power receiving unit having a power receiving coil, a power receiving electrode, etc. are arranged to face each other. However, when non-contact power supply is applied to supply power to a transport cart, there is a problem that the gap (distance) between the power supply unit and the power receiving unit fluctuates due to vibrations such as lateral swinging of the transport cart, reducing the power supply efficiency. In addition, when wireless power transmission technology is applied to transport carts used in factories, etc., there is a problem that foreign matter such as dust adheres to and accumulates on the power supply unit and the power receiving unit, reducing the power supply efficiency.

[0006] For example, the following techniques are known for dealing with variations in the gap between the power supply unit and the power receiving unit. Patent Document 1 discloses a contactless power supply device using an electromagnetic induction method, which includes a variable step-up transformer in the power transmission circuit and switches the voltage stepwise by tap switching in response to changes in the coupling coefficient K between the power transmission coil and the power receiving coil caused by gap variations. This makes it possible to suppress variations in the induced voltage of the power receiving coil.

[0007] Patent Document 2 discloses a technology for a contactless charging system that transmits power contactlessly from a power supply coil installed on a road to a power receiving coil mounted on a vehicle, the technology including a power supply drive device that changes the attitude of the power supply coil with respect to the road, and a power receiving drive device that changes the attitude of the power receiving coil with respect to the vehicle body. This technology includes a control device that controls the power supply drive device and the power receiving drive device based on the angle between the front direction of the power supply coil and the front direction of the power receiving coil so that the power supply coil and the power receiving coil approach a state where they face each other directly. In this case, it is considered preferable that the power supply drive device and the power receiving drive device have a parallel link mechanism with six degrees of freedom.

[0008] Furthermore, for example, the following technology is known to address the decrease in power supply efficiency caused by the accumulation of dust, foreign objects, etc. in the power transmitting unit and the power receiving unit. Patent Document 3 discloses a technology in which a foreign object detection unit is provided between the power transmitting unit and the power receiving unit, which detects foreign objects when the power receiving unit receives power from the power transmitting unit, and controls the power transmitted from the power transmitting unit when a foreign object is detected by the foreign object detection unit.

[0009] Patent Document 4 discloses a non-contact power transmission device including a detector coil that is provided on a housing case of a power transmission coil and is capable of detecting metal, a temperature sensor that is capable of detecting the temperature on the housing case, and a control unit that controls power transmission to the power transmission coil and metal detection using the detector coil. In this case, the control unit controls power transmission so that power is intermittently supplied to the power transmission coil in response to a command to start power transmission, and performs metal detection using the detector coil when power is not supplied to the power transmission coil. Meanwhile, the control unit stops metal detection using the detector coil when power is supplied to the power transmission coil, and monitors the temperature with a temperature sensor at least when power is supplied to the power transmission coil. This is said to enable accurate detection of foreign objects throughout the time during power transmission. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2018-107910 A [Patent Document 2] JP 2020-36389 A [Patent Document 3] JP 2014-230299 A [Patent Document 4] JP 2015-204707 A Summary of the Invention [Problem to be solved by the invention]

[0011] However, the above-mentioned conventional techniques have the following problems.

[0012] The technology described in Patent Document 1 targets contactless power supply devices that employ an electromagnetic induction method or a magnetic resonance method, and suppresses induced voltage fluctuations in the receiving coil in response to fluctuations in the gap between the transmitting coil and the receiving coil to maintain rated output. However, since fluctuations in the gap between the transmitting unit and the receiving unit are permitted, although the induced voltage fluctuations in the receiving coil are suppressed, the problem of reduced power supply efficiency of power supplied from the transmitting coil to the receiving coil cannot be addressed. In addition, there is a problem in that the technology cannot be applied to contactless power supply devices that use an electric field coupling method.

[0013] The technology described in Patent Document 2 can suppress the variation of the gap between the power transmission coil and the power receiving coil by controlling the attitude between the power transmission coil and the power receiving coil. However, since the power transmission coil is installed on the road and the power receiving coil is controlled to face it, there is a problem that the power supply efficiency of the power supplied from the power transmission coil to the power receiving coil decreases in an environment where dust or foreign matter accumulates on the upper surface of the power transmission coil. In addition, the power supply drive device and the power receiving drive device described in Patent Document 2 have a parallel link mechanism with six degrees of freedom, and there is a problem that the movable part of the link mechanism is prone to failure in an environment where dust or foreign matter accumulates.

[0014] The technologies described in Patent Documents 3 and 4 address the issue of foreign objects being heated when they get between the power transmission unit and the power receiving unit, which can cause safety problems. However, transport carts that transport objects in factories such as steelworks can scatter foreign objects including dust and accumulate on the power transmission unit or the power receiving unit, which poses a problem that it is difficult to stably supply power simply by detecting foreign objects that get between the power transmission unit and the power receiving unit.

[0015] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a power supply system and a power supply method for a transport vehicle that can perform stable contactless power supply to the transport vehicle without being affected by foreign objects, etc. [Means for solving the problem]

[0016] [1] A power supply system for a transport vehicle that supplies power to the transport vehicle in a non-contact manner, the power supply system having a power supply unit that is installed in an upright position relative to a horizontal surface and supplies power to the transport vehicle, and a power receiving unit that is provided on the transport vehicle in an upright position relative to the horizontal surface and receives power supplied from the power supply unit when in a position opposite the power supply unit. [2] The power supply system for a transport vehicle described in [1], further comprising a distance adjustment unit provided in at least one of the power supply unit and the power receiving unit, and configured to adjust the distance between the power supply unit and the power receiving unit when the power supply unit and the power receiving unit are in opposing positions. [3] The power supply system for a transport vehicle described in [2], wherein the gap adjustment unit is provided in the power receiving unit and is provided at a position opposite the power supply unit across the power receiving unit when the power supply unit and the power receiving unit are in opposing positions, and the gap adjustment unit has an elastic member that applies pressure in a direction to bring the power receiving unit closer to the power supply unit, and a spacer member that extends from the power receiving unit toward the power supply unit and separates the power receiving unit and the power supply unit. [4] The power supply system for a transport vehicle described in [2], wherein the gap adjustment unit is provided in the power supply unit and is provided at a position opposite the power receiving unit across the power supply unit when the power supply unit and the power receiving unit are in opposing positions, and the gap adjustment unit has an elastic member that applies pressure in a direction to bring the power supply unit closer to the power receiving unit, and a spacer member that extends from the power supply unit toward the power receiving unit and separates the power supply unit and the power receiving unit. [5] A power supply system for a transport vehicle described in [3] or [4], wherein the elastic member is a spring member and the spacer member has a guide wheel at its tip that can rotate along the traveling direction of the transport vehicle. [6] The power supply system for a transport vehicle described in [5], further comprising a guide member for positioning the guide wheels in the vertical direction. [7] A power supply method for a transport vehicle that supplies power to the transport vehicle non-contactly, the method comprising: a traveling stopping step of stopping the travel of the transport vehicle when a power receiving unit provided on the transport vehicle in an upright position relative to a horizontal surface is in a position facing a power supply unit installed in an upright position relative to the horizontal surface; and a power supply step of supplying power from the power supply unit to the power receiving unit. Effect of the Invention

[0017] According to the present invention, stable non-contact power supply to a transport vehicle can be performed without being affected by foreign objects or the like. [Brief description of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating an example of a schematic configuration of a power supply system according to a first embodiment. [Diagram 2] 4 is a diagram showing an example of a schematic configuration of a gap adjustment unit in the first embodiment. FIG. [Diagram 3] 2 is a diagram showing a schematic configuration of a state in which power is supplied to a transportation vehicle by a power supply system in the first embodiment. FIG. [Figure 4] 13 is a diagram showing an example of a schematic configuration of a gap adjustment section in a second embodiment. FIG. [Diagram 5] 13 is a diagram showing an example of a schematic configuration of a gap adjustment section in a third embodiment. FIG. [Figure 6] 13 is a diagram showing an example of a schematic configuration of a second support member in the fourth embodiment. FIG. [Figure 7] FIG. 13 is a plan view showing a schematic configuration of a process in which a power receiving unit provided with a gap adjustment unit approaches a power supply unit while being guided by a guide member in a fourth embodiment. [Figure 8] FIG. 13 is a diagram showing an example of a schematic configuration of a state in which a power receiving unit has reached a position opposite a power supply unit in a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows an example of a schematic configuration of a power supply system 1. In Fig. 1, the directions toward the front and back of the drawing correspond to the traveling direction of a transport vehicle 20.

[0020] As shown in FIG. 1, the power supply system 1 includes a power supply device 10 and a transport vehicle 20. The transport vehicle 20 includes a power receiving device 21 and a transport cart 26. The power receiving device 21 is provided above the transport cart 26 and moves together with the transport cart 26 as the transport cart 26 travels. The power supply device 10 includes a power supply unit 11, a power source unit 12, and a charging inverter 13. The power receiving device 21 includes a power receiving unit 22, a charging controller 23, a power storage unit 24, and an inverter 25. The transport cart 26 includes an electric motor 27 and a wheel unit 28. In this embodiment, a distance adjustment unit 30 is provided in the power receiving unit 22. The distance adjustment unit 30 will be described later.

[0021] The transport vehicle 20 may travel along a track 70 laid in advance by driving the wheel section 28 of the transport cart 26. By traveling the transport vehicle 20 along the track 70, it is possible to stop the transport vehicle 20 at the position of the power supply device 10 that has been installed in advance along the track 70, and the relative positional relationship between the power supply unit 11 of the power supply device 10 and the power receiving unit 22 of the power receiving device 21 can be accurately adjusted during non-contact power supply. The transport vehicle 20 may travel on a horizontal plane G by driving the wheel section 28 of the transport cart 26.

[0022] The transporting cart 26 has an electric motor 27 for driving the wheel unit 28. The transporting cart 26 may have a power transmission device such as a transmission for transmitting the driving force from the electric motor 27 to the wheel unit 28. The transporting cart 26 may have an oil supply pump for preventing poor lubrication of the wheel unit 28 in order to maintain stable traveling. The transporting cart 26 may have a cooling fan for cooling the electric motor 27. The oil supply pump and the cooling fan may be driven by the driving force from the electric motor 27.

[0023] The electric motor 27 may be any electric motor, such as a drive motor for running the transporting cart 26 or an auxiliary motor other than a drive motor. The electric motor 27 of the transporting cart 26 may be supplied with AC power from the power storage unit 24 and the inverter 25. The transporting cart 26 may be equipped with a brake, relays used to control various devices, wireless communication devices, etc., in addition to the electric motor 27. In this case, the brakes, relays, wireless communication devices, etc. may be supplied with AC power from the power storage unit 24 and the inverter 25.

[0024] The power supply unit 12 of the power supply device 10 is a supply source of power supplied to the transport cart 26 of the transport vehicle 20. The power supply unit 12 may be, for example, a system power supply and may be configured to be capable of supplying a three-phase 200V AC voltage. The charging inverter 13 converts the frequency of the AC power supplied from the power supply unit 12 to a frequency suitable for power supply for contactless power supply. The frequency suitable for contactless power supply differs depending on the method of wireless power transmission. For example, in the electromagnetic induction method, the 50 Hz or 60 Hz AC voltage supplied from the power supply unit 12 may be converted to a frequency of 5 to 10 kHz. In the magnetic resonance method, the 50 Hz or 60 Hz AC voltage supplied from the power supply unit 12 may be converted to a frequency of about 100 to 15 MHz. In the electric field coupling method, the 50 Hz or 60 Hz AC voltage supplied from the power supply unit 12 may be converted to a frequency of 100 to 3000 kHz.

[0025] As shown in FIG. 1, power supply unit 11 is installed in an upright state with respect to horizontal plane G. Here, "upright state" refers to a state in which power supply unit 11 is arranged so that the normal direction of the plane of power supply unit 11 formed in a planar shape is approximately horizontal to horizontal plane G. Specifically, power supply unit 11 may be arranged so that the angle between the normal line of the plane forming power supply unit 11 and horizontal plane G is 0 to 30°. The angle between the normal line of the plane forming power supply unit 11 and horizontal plane G is preferably 0 to 10°. In addition, it is preferable that the normal line of the plane forming power supply unit 11 is perpendicular to the traveling direction of transport cart 26 at the position where power is supplied to transport cart 26 of transport vehicle 20.

[0026] The power receiving unit 22 of the power receiving device 21 is provided on the transport vehicle 20 in a state in which it stands upright with respect to the horizontal plane G. The "standing upright state" refers to a state in which the power receiving unit 22, which is formed in a planar shape, is arranged so that the normal direction of the plane is approximately horizontal to the horizontal plane G. Specifically, the power receiving unit 22 may be arranged so that the angle between the normal to the plane forming the power receiving unit 22 and the horizontal plane G is 0 to 30°. The angle between the normal to the plane forming the power receiving unit 22 and the horizontal plane G is preferably 0 to 10°. In addition, it is preferable that the normal to the plane forming the power receiving unit 22 is in a position where it is possible to supply power to the transport cart 26 of the transport vehicle 20, and is perpendicular to the traveling direction of the transport cart 26. As a result, when the transport vehicle 20 stops at the position of the pre-installed power supply device 10, the power receiving unit 22 of the power receiving device 21 and the power supply unit 11 of the power supply device 10 are opposed to each other, making it possible to supply power from the power supply unit 11 to the power receiving unit 22.

[0027] The power receiving unit 22 receives AC power supplied from the power supply unit 11 in a contactless manner. In this case, when an electromagnetic induction method is used as the wireless power transmission technology, the power receiving unit 22 may include a power receiving coil. In the case of using a magnetic resonance method, the power receiving unit 22 may include a capacitor in addition to a secondary coil for forming a resonance circuit. In the case of using an electric field coupling method, the power receiving unit 22 may include a secondary coil in addition to a power receiving electrode that forms a capacitor.

[0028] The charging controller 23 converts the AC power received by the power receiving unit 22 into DC power. That is, the charging controller 23 includes a filter circuit and a rectifier. The filter circuit suppresses harmonic noise in the AC power received by the power receiving unit 22. The filter circuit may be configured, for example, by an LC filter including an inductor and a capacitor. The rectifier rectifies the AC power received by the power receiving unit 22 to convert it into DC power.

[0029] The power storage unit 24 stores the power rectified by the charging controller 23. The power storage unit 24 may be configured with a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The voltage of the power storage unit 24 may be, for example, about 200 V. A relay may be provided between the charging controller 23 and the power storage unit 24. The relay is turned on (ON) when the power storage unit 24 is charged by the supply of power from the power supply device 10.

[0030] The inverter 25 converts the DC power stored in the power storage unit 24 into AC power required to drive the electric motor 27 of the transport cart 26. The electric motor 27 may be driven by the power supplied from the inverter 25.

[0031] The power receiving device 21 and the power supply device 10 may have antenna equipment capable of wireless communication with each other. Then, while the transportation vehicle 20 is traveling, various information collected by the transportation vehicle 20 may be temporarily collected by the power receiving device 21, and then the various information may be transmitted to the power supply device 10 by wireless communication. By having the antenna equipment, various information regarding the transportation vehicle 20 can be collected, and the traveling state of the transportation vehicle 20 can be monitored in real time.

[0032] The antenna equipment may be used to detect that power supply unit 11 and power receiving unit 22 are in a close proximity to each other and are facing each other. For example, the antenna equipment may detect that power supply unit 11 and power receiving unit 22 are in a close proximity to each other, and release the interlock for starting power supply when a predetermined positional relationship is reached.

[0033] Power supply unit 11 supplies power to power receiving unit 22 of power receiving device 21 in a contactless manner. Specifically, power supply unit 11 supplies power to power receiving unit 22 when it is located opposite power receiving unit 22. In other words, power receiving unit 22 receives power from power supply unit 11 when it is located opposite power supply unit 11. That is, power supply unit 11 and power receiving unit 22 form a pair to perform contactless power supply.

[0034] A known technology as a wireless power transmission technology can be applied to the non-contact power supply between the power supply unit 11 and the power receiving unit 22. Examples of the wireless power transmission technology include an electromagnetic induction method, a magnetic resonance method, and an electric field coupling method. The electromagnetic induction method is a method in which an AC magnetic field generated by a power transmission coil is passed through a power receiving coil to generate an AC current by electromagnetic induction in the power receiving coil. In this case, the power transmission coil constitutes the power supply unit 11, and the power receiving coil constitutes the power receiving unit 22. The magnetic resonance method is a method in which power is transmitted to the power receiving coil by resonance caused by vibration of a magnetic field generated by the power transmission coil. In this case, the power transmission coil constitutes the power supply unit 11, and the power receiving coil constitutes the power receiving unit 22. The electric field coupling method is a method in which a capacitor is formed with a power transmission electrode and a power receiving electrode facing each other, and AC power is transmitted wirelessly from the power transmission electrode to the power receiving electrode by passing a high-frequency current through the capacitor. In this case, the power transmission electrode constitutes the power supply unit 11, and the power receiving electrode constitutes the power receiving unit 22.

[0035] In any contactless power supply, the power supply unit 11 and the power receiving unit 22 are arranged at a predetermined distance (gap) from each other, thereby enabling contactless power supply. In addition, the opposing area between the power supply unit 11 and the power receiving unit 22 may be increased in order to increase the amount of power supplied. For example, the power supply unit 11 and the power receiving unit 22 may be configured as an integrated member (pad) by arranging coils or electrodes on the same plane and covering them with an insulating housing case. In this case, a power transmission pad that houses a power transmission coil or a power transmission electrode functions as the power supply unit 11, and a power receiving pad that houses a power receiving coil or a power receiving electrode functions as the power receiving unit 22.

[0036] In this embodiment, even in an environment where foreign matter such as dust is scattered around, by arranging power supply unit 11 in an upright state with respect to horizontal plane G as shown in Fig. 1, it is possible to prevent accumulation of foreign matter on the plane of power supply unit 11 and prevent a decrease in power supply efficiency. Similarly, by arranging power receiving unit 22 in an upright state with respect to horizontal plane G, it is possible to prevent accumulation of foreign matter on the plane of power receiving unit 22 and prevent a decrease in power receiving efficiency. Furthermore, in this embodiment, because power supply unit 11 and power receiving unit 22 are arranged in an upright state with respect to horizontal plane G, it is easy to visually inspect power supply unit 11 and power receiving unit 22, making it easy for workers to determine whether maintenance inspection is necessary.

[0037] Next, the gap adjustment unit 30 according to the present invention will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of a schematic configuration of the gap adjustment unit 30. Fig. 2(a) shows a schematic front view of the gap adjustment unit 30. Fig. 2(b) shows a schematic plan view of the gap adjustment unit 30. Fig. 2(c) shows a schematic side view of the gap adjustment unit 30.

[0038] In the power supply system 1, when the power supply unit 11 and the power receiving unit 22 are positioned facing each other (see FIG. 1), it is preferable that a distance adjustment unit 30 that adjusts a distance D between the power supply unit 11 and the power receiving unit 22 is provided in at least one of the power supply unit 11 and the power receiving unit 22. FIG. 2 shows an example of a configuration in which the distance adjustment unit 30 is provided in the power receiving unit 22.

[0039] 2, the gap adjustment unit 30 has an elastic member 31, a spacer member 32, a front support member 33, and a rear support member 34. When the power supply unit 11 and the power receiving unit 22 are in a position facing each other (see FIG. 1), the surface of the power receiving unit 22 opposite the side facing the power supply unit 11 is fixed to the front support member 33. The front support member 33 is supported between the power receiving unit 22 and the rear support member 34 provided on the transport cart 26 via the elastic member 31. That is, the elastic member 31 is provided at a position opposite the power supply unit 11 across the power receiving unit 22, and applies pressure in a direction to bring the power receiving unit 22 closer to the power supply unit 11.

[0040] The elastic member 31 is a member that, when subjected to an external force via the front support member 33, is displaced so as to contract in proportion to the external force, and that recovers (returns to its original state) when the external force is removed. Rubber, spring members, etc. may be used as the elastic member 31. The rubber used as the elastic member 31 is preferably an elastic rubber in which the elastic modulus and mechanical strength are adjusted by adding sulfur to raw rubber. The spring used as the elastic member 31 may be a coil spring, a leaf spring, a disc spring, etc. As the coil spring, it is particularly preferable to use a compression coil spring. This is because a compression coil spring has a high degree of freedom in designing the outer diameter, free height, allowable load, spring constant, etc. of the spring.

[0041] It is preferable to use a plurality of compression coil springs in order to suppress fluctuations in the distance D between the power supply unit 11 and the power receiving unit 22. For this reason, in this embodiment, a plurality of elastic members 31 (compression coil springs) are provided between the front support member 33 and the rear support member 34. Furthermore, when the front support member 33 and the rear support member 34 form a rectangular plane, it is preferable to arrange the elastic members 31 (compression coil springs) at the four corners of the rectangle.

[0042] The size of the elastic member 31 maintains its initial uncontracted length when not subjected to an external force. The size of the elastic member 31 maintains a contracted length that is shorter than the initial length when subjected to an external force. The contracted length of the elastic member 31 decreases in inverse proportion to the magnitude of the external force acting on the elastic member 31. The initial length of the elastic member 31 may be designed in advance based on the contracted length assumed when the power supply unit 11 and the power receiving unit 22 are positioned opposite each other, taking into account the distance D between the power supply unit 11 and the power receiving unit 22.

[0043] As shown in FIG. 2, the interval adjustment unit 30 has a spacer member 32 that separates the power receiving unit 22 and the power supply unit 11 when the power supply unit 11 and the power receiving unit 22 are in opposing positions (see FIG. 1). Specifically, the spacer member 32 has a long length H so that the front support member 33 that supports the power receiving unit 22 and the other support member (not shown in FIG. 2) that supports the power supply unit 11 are not too close to each other. This makes it possible to prevent contact between the power supply unit 11 and the power receiving unit 22. In addition, the spacer member 32 preferably has a guide wheel 32a at the tip that can rotate along the traveling direction of the transport vehicle 20. By having the guide wheel 32a, it is possible to reduce the contact resistance between the other support member 80 provided on the power supply unit 11 and the spacer member 32 when the transport vehicle 20 travels and stops. That is, the spacer member 32 extends from the power receiving unit 22 toward the power supply unit 11, and separates the power receiving unit 22 from the power supply unit 11. The spacer member 32 may be made of a metal member to ensure strength.

[0044] As described with reference to FIG. 2, in this embodiment, the interval adjustment unit 30 has a configuration in which an elastic member 31 that applies pressure in a direction in which the power supply unit 11 and the power receiving unit 22 approach each other and a spacer member 32 that separates the power supply unit 11 and the power receiving unit 22 are combined. Therefore, when the power supply unit 11 and the power receiving unit 22 are in a position facing each other, the spacer member 32 can keep the power supply unit 11 and the power receiving unit 22 in a positional relationship that is not too close to each other. In addition, when the transport vehicle 20 stops so that the interval between the power supply unit 11 and the power receiving unit 22 exceeds the interval D (see FIG. 1), the elastic member 31 can move the power receiving unit 22 in a direction in which it approaches the power supply unit 11. Specifically, by designing the initial length of the elastic member 31 to be longer in advance, it becomes easier to move the power receiving unit 22 in a direction in which it approaches the power supply unit 11 even if the power receiving unit 22 is far away from the power supply unit 11. Therefore, the power receiving unit 22 provided with the gap adjustment unit 30 can be adjusted to an appropriate position with respect to the position of the power supply unit 11. Then, the gap D between the power supply unit 11 and the power receiving unit 22 can be adjusted within an appropriate range, and fluctuations in the gap D can be suppressed, thereby enabling stable contactless power supply to the transport vehicle 20.

[0045] Here, the appropriate distance for the distance D between the power supply unit 11 and the power receiving unit 22 differs depending on the type of wireless power transmission technology (contactless power supply). In the electromagnetic induction type and the electric field coupling type, the distance D is preferably 10 to 100 mm. In the magnetic resonance type, the appropriate range of the distance D is wide, so the distance is preferably 10 to 3000 mm. For this reason, it is preferable to adjust the length H of the spacer member 32 and the thickness in the opposing direction of the power supply unit 11 and the power receiving unit 22 to appropriate sizes in advance so that the distance D between the power supply unit 11 and the power receiving unit 22 is appropriate for each type of wireless power transmission technology (contactless power supply).

[0046] Next, a configuration for supplying power to the transportation vehicle 20 by the power supply system 1 according to the present invention will be described with reference to Fig. 3. Fig. 3 shows a schematic configuration diagram of a state in which the power supply system 1 supplies power to the transportation vehicle 20.

[0047] First, when it becomes necessary to supply power to the transport cart 26, the transport vehicle 20 travels along the track 70 and moves to a position where the power supply device 10 is arranged. After that, the transport vehicle 20 is stopped at a position where the power supply unit 11 of the power supply device 10 and the power receiving unit 22 of the power receiving device 21 of the transport vehicle 20 face each other. FIG. 3 is a schematic front view showing the state of the power supply device 10 and the transport vehicle 20 when the transport vehicle 20 is stopped. Then, as shown in FIG. 3, the distance D between the power supply unit 11 and the power receiving unit 22 is appropriately adjusted by the distance adjustment unit 30 when the power supply unit 11 and the power receiving unit 22 are in a position where they face each other.

[0048] In this case, even if vibrations such as lateral swaying of the transport vehicle 20 occur when the transport vehicle 20 runs and stops, the vibrations are absorbed by the elastic force of the elastic member 31 in the distance adjustment unit 30, suppressing fluctuations in the distance D between the power supply unit 11 and the power receiving unit 22. Furthermore, because the spacer member 32 of the distance adjustment unit 30 abuts against the other support member 80 that supports the power supply unit 11, contact between the power supply unit 11 and the power receiving unit 22 is avoided even if vibrations occur in the transport vehicle 20, and damage to the power supply system 1 due to contact between the components can be prevented.

[0049] Furthermore, because power supply unit 11 and power receiving unit 22 are installed in an upright state relative to horizontal plane G, accumulation of foreign matter such as dust on the plane of power supply unit 11 and power receiving unit 22 can be avoided, preventing a decrease in power supply efficiency. Also, because power supply unit 11 and power receiving unit 22 are arranged in an upright state relative to horizontal plane G, visual inspection of power supply unit 11 and power receiving unit 22 becomes easy, making it easy for workers to determine whether maintenance inspection is required.

[0050] In a state where the power supply unit 11 and the power receiving unit 22 face each other, the power supply unit 11 supplies power to the power receiving unit 22. The power supply from the power supply unit 11 to the power receiving unit 22 may be executed on the condition that no abnormality occurs in each device constituting the power supply system 1 and that the power storage unit 24 of the power receiving device 21 is not fully charged. In addition, when the power supply unit 11 and the power receiving unit 22 have an antenna facility, it may be confirmed using the antenna facility whether the power supply unit 11 and the power receiving unit 22 are in a predetermined positional relationship, and after it is confirmed that the predetermined positional relationship is established, power supply from the power supply unit 11 to the power receiving unit 22 may be started after a preset time (0.5 to 3 seconds) has elapsed.

[0051] On the other hand, if the conditions for starting power supply are not met, an error signal may be sent from the power supply device 10 or the power receiving device 21 to notify that the conditions for power supply are not met. This allows the operator of the transport vehicle 20 to investigate the cause of the error signal being sent and take measures to satisfy the conditions for power supply.

[0052] As described above, the power supply system 1 in this embodiment may be used to perform a power supply method for the transport vehicle 20 that supplies power to the transport vehicle 20 in a non-contact manner. Specifically, the power supply method for the transport vehicle 20 may include a travel stopping step of stopping the travel of the transport vehicle 20 when the power receiving unit 22, which is provided on the transport vehicle 20 in an upright state with respect to a horizontal plane G, is located at a position facing the power supply unit 11, which is provided in an upright state with respect to the horizontal plane G, and a power supply step of supplying power from the power supply unit 11 to the power receiving unit 22.

[0053] <Second embodiment> Next, a second embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of a schematic configuration of a gap adjustment unit 40 in the second embodiment. Fig. 4(a) shows a schematic configuration diagram in a state where the power supply unit 11 and the power receiving unit 22 are positioned to face each other. Fig. 4(b) shows a schematic configuration diagram in a state where the power supply unit 11 and the power receiving unit 22 are positioned to face each other and are adjusted to a position where a gap D suitable for contactless power supply is maintained. Note that, with regard to each configuration in the second embodiment that is the same as that in the first embodiment, the same reference numerals are used and the description thereof is omitted.

[0054] In the second embodiment, the power supply system 1 may include a distance adjustment unit 40 in the power supply unit 11 that adjusts a distance D between the power supply unit 11 and the power receiving unit 22 when the power supply unit 11 and the power receiving unit 22 are positioned opposite each other. Fig. 4 shows an example of a configuration in which the distance adjustment unit 40 is provided in the power supply unit 11.

[0055] 4(a), the gap adjustment unit 40 has an elastic member 41, a spacer member 42, a front support member 43, and a rear support member 44. When the power supply unit 11 and the power receiving unit 22 are in opposing positions, the surface of the power supply unit 11 opposite the side facing the power receiving unit 22 is fixed to the front support member 43. The front support member 43 is supported between the power supply unit 11 and the rear support member 44, which is fixed with respect to a horizontal plane G, via the elastic member 41. That is, the elastic member 41 is provided at a position opposite the power receiving unit 22 across the power supply unit 11, and applies pressure in a direction to bring the power supply unit 11 closer to the power receiving unit 22.

[0056] The elastic member 41, like the elastic member 31 in the first embodiment, is a member that, when subjected to an external force via the front support member 43, is displaced so as to contract in proportion to the external force, and that recovers (returns to its original shape) from the displacement when the external force is removed. The elastic member 41 may be made of rubber, a spring member, or the like. As with the elastic member 31, it is preferable to use a plurality of compression coil springs as the elastic member 41 in order to suppress fluctuations in the distance D between the power supply unit 11 and the power receiving unit 22.

[0057] The size of elastic member 41 maintains its initial uncontracted length when not subjected to an external force. The size of elastic member 41 maintains a contracted length that is shorter than the initial length when subjected to an external force. The contracted length of elastic member 41 decreases in inverse proportion to the magnitude of the external force acting on elastic member 41. The initial length of elastic member 41 may be designed in advance, taking into account the distance D between power supply unit 11 and power receiving unit 22, based on the contracted length expected when power supply unit 11 and power receiving unit 22 are positioned opposite each other.

[0058] As shown in Fig. 4(a), the interval adjustment unit 40 has a spacer member 42 that separates the power receiving unit 22 and the power supply unit 11 when the power supply unit 11 and the power receiving unit 22 are in opposing positions. Specifically, the spacer member 42 has a long length H so that the front support member 43 that supports the power supply unit 11 and the other support member 81 that supports the power receiving unit 22 are not too close to each other. Therefore, as shown in Fig. 4(b), even when the power supply unit 11 and the power receiving unit 22 are brought close to each other, contact between the power supply unit 11 and the power receiving unit 22 can be prevented. The other support member 81 that supports the power receiving unit 22 is fixed to the power receiving device 21 in the transport vehicle 20.

[0059] Moreover, it is preferable that the spacer member 42 has a guide wheel 42a at its tip that is rotatable in the traveling direction of the transport vehicle 20. By having the guide wheel 42a, it is possible to reduce the contact resistance between the spacer member 42 and the other support member 81 provided on the power receiving unit 22 when the transport vehicle 20 travels and stops. That is, the spacer member 42 extends from the power supply unit 11 toward the power receiving unit 22 and has a configuration that separates the power receiving unit 22 and the power supply unit 11. The spacer member 42 may be made of a metal member to ensure strength.

[0060] As described with reference to FIG. 4, in the second embodiment, the interval adjustment unit 40 has a configuration in which an elastic member 41 that applies pressure in a direction in which the power supply unit 11 and the power receiving unit 22 approach each other and a spacer member 42 that separates the power supply unit 11 and the power receiving unit 22 are combined. Therefore, when the power supply unit 11 and the power receiving unit 22 are in a position facing each other, the spacer member 42 can keep the power supply unit 11 and the power receiving unit 22 in a positional relationship that is not too close to each other. Furthermore, when the transport vehicle 20 stops so that the interval between the power supply unit 11 and the power receiving unit 22 exceeds the interval D, the elastic member 41 can move the power supply unit 11 in a direction in which it approaches the power receiving unit 22. Specifically, by designing the initial length of the elastic member 41 to be longer in advance, it becomes easier to move the power receiving unit 22 in a direction in which it approaches the power supply unit 11 even if the power receiving unit 22 is far away from the power supply unit 11. Therefore, power supply unit 11 provided with gap adjustment unit 40 can be adjusted to an appropriate position with respect to the position of power receiving unit 22. Furthermore, gap D between power supply unit 11 and power receiving unit 22 can be adjusted within an appropriate range, and fluctuations in gap D can be suppressed, thereby enabling stable contactless power supply to transport vehicle 20. Note that gap adjustment units that adjust the gap between power supply unit 11 and power receiving unit 22 may be provided in both power supply unit 11 and power receiving unit 22.

[0061] <Third embodiment> Next, a third embodiment of the present invention will be described with reference to Fig. 5. Fig. 5 is a diagram showing an example of a schematic configuration of a gap adjustment unit 50 in the third embodiment. Fig. 5(a) shows a schematic configuration diagram in a state where the power supply unit 11 and the power receiving unit 22 are positioned to face each other. Fig. 5(b) shows a schematic configuration diagram in a state where the power supply unit 11 and the power receiving unit 22 are positioned to face each other and are adjusted to a position where a gap D suitable for contactless power supply is maintained. Note that, with regard to each configuration in the third embodiment that is the same as that in the second embodiment, the same reference numerals are used and the description thereof is omitted.

[0062] In the third embodiment, similarly to the second embodiment, the gap adjustment part 50 is provided in the power supply unit 11. As shown in Fig. 5(a) , the gap adjustment part 50 has an elastic member 51, a spacer member 52, and a front support member 53. When the power supply unit 11 and the power receiving unit 22 are in opposing positions, the surface of the power supply unit 11 opposite the side facing the power receiving unit 22 is fixed to the front support member 53.

[0063] 5(a), an elastic member 51 is provided on the front support member 53 so as to extend from the front support member 53 toward the other support member 81 that fixes the power receiving unit 22. Furthermore, a spacer member 52 is provided at the tip of the elastic member 51 at a position where it is connected in series to the elastic member 51.

[0064] The elastic member 51, like the elastic member 41 in the second embodiment, is a member that, when subjected to an external force via the other support member 81, is displaced so as to contract in proportion to the external force, and that recovers (returns to its original shape) from the displacement when the external force is removed. The elastic member 51 may be made of rubber, a spring member, or the like.

[0065] Spacer member 52 has a long length H so that the distance between front support member 53 supporting power supply unit 11 and other support member 81 supporting power receiving unit 22 is not too close to each other. Therefore, even if power supply unit 11 and power receiving unit 22 are brought close to each other, contact between power supply unit 11 and power receiving unit 22 can be prevented as shown in FIG. 5(b). Other support member 81 supporting power receiving unit 22 is fixed to power receiving device 21 in transport vehicle 20.

[0066] In the third embodiment, the power supply unit 11 and the power receiving unit 22 are separated from each other by the elastic member 51 and the spacer member 52 in the configuration shown in FIG. 5. This avoids contact between the power supply unit 11 and the power receiving unit 22, and prevents damage to the power supply system 1 due to contact between the components. Furthermore, the elastic member 51 acts to suppress fluctuations in the distance D between the power supply unit 11 and the power receiving unit 22, thereby enabling stable contactless power supply to the transport vehicle 20. In the third embodiment, when the transport vehicle 20 stops so that the distance between the power supply unit 11 and the power receiving unit 22 exceeds the distance D, the elastic member 51 does not act to bring the power supply unit 11 closer to the power receiving unit 22. Therefore, this embodiment may be applied to a transport vehicle 20 that uses a wireless power transmission method that has a wide tolerance range for the upper limit value of the distance D.

[0067] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIG. 6. FIG. 6 is a diagram showing an example of a schematic configuration of the other side support member 80 in the fourth embodiment. FIG. 6(a) shows a schematic front view of the other side support member 80. FIG. 6(b) shows a schematic plan view of the other side support member 80. FIG. 6(c) shows a schematic side view of the other side support member 80. Note that, with regard to each configuration in the fourth embodiment, configurations similar to those in the first embodiment are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0068] In the fourth embodiment, the power supply system 1 includes a distance adjustment unit 30 for adjusting a distance D between the power supply unit 11 and the power receiving unit 22, which is provided in the power receiving unit 22. FIG. 6 shows an example of a schematic configuration of a second support member 80 for supporting the power supply unit 11.

[0069] On the other hand, as shown in FIG. 6, it is preferable that the support member 80 has a guide member 60 that guides the movement of the spacer member 32 when the power supply unit 11 and the power receiving unit 22 are positioned opposite each other and the distance D between the power supply unit 11 and the power receiving unit 22 is adjusted by the distance adjustment unit 30.

[0070] Specifically, when the power receiving unit 22 approaches the power supply unit 11 as the transport vehicle 20 travels, the guide member 60 guides the spacer member 32 of the distance adjustment unit 30 to a position where the power receiving unit 22 and the power supply unit 11 face each other. For this reason, the guide member 60 preferably has a concave cross section as shown in FIG. 6 so that the guide wheel 32a at the tip of the spacer member 32 can pass through. By providing the guide member 60 on the other support member 80, the spacer member 32 can be smoothly positioned in the vertical direction. Therefore, the power receiving unit 22 can be appropriately aligned with the power supply unit 11 in the vertical direction.

[0071] Furthermore, before the power receiving unit 22 approaches the power supply unit 11, the elastic member 31 causes the spacer member 32 to protrude toward the other support member 80. For this reason, in order to reduce the impact caused by contact between the spacer member 32 and the guide member 60 when the transport vehicle 20 stops, it is preferable that the guide member 60 has a guide inclined portion 61 that is inclined with respect to the traveling direction of the transport vehicle 20.

[0072] Here, the process in which the power receiving unit 22 provided with the interval adjustment unit 30 approaches the power supply unit 11 while being guided by the guide member 60 due to the travel of the transport vehicle 20 will be described with reference to Fig. 7. Fig. 7 is a plan view showing a schematic configuration of the process in which the power receiving unit 22 provided with the interval adjustment unit 30 approaches the power supply unit 11 while being guided by the guide member 60. Fig. 7(a) shows a state before the power receiving unit 22 approaches the power supply unit 11 while the transport vehicle 20 is traveling. Fig. 7(b) shows a state in which the power receiving unit 22 has reached the inclined guide portion 61 of the guide member 60. Fig. 7(c) shows a state in which the power receiving unit 22 has reached a position facing the power supply unit 11 and the transport vehicle 20 has stopped.

[0073] Here, in the state shown in Figure 7 (b), the spacing adjustment unit 30 has a rear support member 34 provided on the power receiving device 21 fixed in a width direction B perpendicular to the traveling direction A of the spacing adjustment unit 30 (corresponding to the direction in which the transport vehicle 20 travels), while the front support member 33 supporting the power receiving unit 22 inclines along the guide inclination portion 61 due to elastic deformation of the elastic member 31.

[0074] Next, the state in which power receiving unit 22 has reached a position opposite power supply unit 11 and transport vehicle 20 has stopped (see FIG. 7(c)) will be described in detail with reference to FIG. 8. FIG. 8 shows an example of a schematic configuration in the state in which power receiving unit 22 has reached a position opposite power supply unit 11. FIG. 8(a) shows a schematic front view in the state in which power receiving unit 22 has reached a position opposite power supply unit 11. FIG. 8(b) shows a schematic plan view in the state in which power receiving unit 22 has reached a position opposite power supply unit 11. FIG. 8(c) shows a schematic side view in the state in which power receiving unit 22 has reached a position opposite power supply unit 11.

[0075] As shown in FIG. 8(b) and FIG. 8(c), in the fourth embodiment, the interval adjustment unit 30 has a configuration in which an elastic member 31 that applies pressure in a direction in which the power supply unit 11 and the power receiving unit 22 approach each other and a spacer member 32 that separates the power supply unit 11 and the power receiving unit 22 are combined. Therefore, when the power supply unit 11 and the power receiving unit 22 are in a position facing each other, the spacer member 32 can be provided to keep the power supply unit 11 and the power receiving unit 22 in a positional relationship in which they are not too close to each other. Furthermore, when the transport vehicle 20 stops so that the interval between the power supply unit 11 and the power receiving unit 22 exceeds the interval D, the elastic member 31 can move the power receiving unit 22 in a direction in which it approaches the power supply unit 11. Therefore, the power receiving unit 22 provided with the interval adjustment unit 30 can be adjusted to an appropriate position with respect to the position of the power supply unit 11. In addition, fluctuations in the distance D between the power supply unit 11 and the power receiving unit 22 can be suppressed, and thus stable contactless power supply to the transport vehicle 20 can be performed. EXAMPLES

[0076] Next, the results of implementing the power supply system and method for a transport vehicle according to the present invention will be described. Specifically, a transport vehicle capable of transporting slabs of up to 75 tons was used as the transport vehicle traveling in a steelworks, and power was supplied to the transport vehicle in a non-contact manner. The supplied power was supplied to the motors for driving the centralized lubrication system, oil supply pump, and cooling fan of the transport vehicle. A three-phase 400V, 5.4kAV power supply was used as the power source.

[0077] In the embodiment, the power supply unit of the power supply device standing on a horizontal plane is provided along the track of the transport vehicle, and the power receiving unit is provided on the power receiving device provided above the transport vehicle, and the transport vehicle runs and stops along the track, so that the power receiving unit can be arranged facing the power supply unit. The power receiving unit is provided on the power receiving device in a state of standing on a horizontal plane. The wireless power transmission technology (non-contact power supply) is a method that incorporates a resonance circuit into the electromagnetic induction method. The power supply unit is three-phase AC 400V, 10kAV, and the charging inverter converts 8kAV power to a frequency of 9.7kHz. The area of ​​the power supply surface of the power supply pad of the power supply unit is 280mm x 368mm. The power receiving surface of the power receiving pad of the power receiving unit also has the same area.

[0078] The spacing between the power supply unit and the power receiving unit is set to a specification that allows contactless power supply within an allowable range of 10 to 60 mm. However, in the embodiment, the spacing adjustment unit is designed with a target spacing range of 25 to 35 mm between the power supply unit and the power receiving unit to provide more stable power supply. The spacing adjustment unit is provided in the power receiving unit. The spacing adjustment unit is configured to include an elastic member made of a compression coil and a spacer member having a guide wheel at its tip.

[0079] The charging controller connected to the power receiving unit outputs the power received by the power receiving unit at a DC voltage of 41 to 60 V. The power storage unit is made up of multiple lithium-ion batteries connected in series, enabling storage of electricity with a nominal voltage of 51.8 V and a nominal capacity of 90 Ah.

[0080] Using the above configuration, after the storage of electricity in the power storage unit was completed by non-contact power supply, the transportation vehicle started traveling. When the transportation vehicle was traveling, the power stored in the power storage unit was converted to AC power via an inverter, and the power was supplied so as to be consumed by the control panel (motor) of the transportation vehicle. Then, when the transportation vehicle traveled along a preset route (track) and stopped at a predetermined stopping position, non-contact power supply was performed to the transportation vehicle in the same manner as described above.

[0081] As a result, it was possible to suppress the fluctuation of the distance between the power supply unit and the power receiving unit without being affected by foreign matter such as dust, and to perform stable contactless power supply to the transport vehicle. Specifically, by applying the power supply system and power supply method for the transport vehicle according to the present invention, it was possible to reduce the downtime required for maintenance and inspection by 60% compared to the conventional method. [Explanation of symbols]

[0082] 1. Power supply system 10 Power supply device 11 Power supply unit 12 Power supply section 13 Charging inverter 20 Transport Vehicle 21 Power receiving device 22 Power receiving section 23 Charging controller 24 Power storage unit 25 Inverter 26 Transport Trolley 27 Electric motor 28 Wheel section 30, 40, 50 spacing adjustment section 31, 41, 51 Elastic member 32, 42, 52 Spacer members 32a, 42a, 52a Guide wheels 33, 43, 53 Front support member 34, 44 Rear support member 60 Guide member 61 Guide inclination 70 orbit 80, 81 other support member A Direction of travel B Width direction H Length of spacer member D Distance between the power source and the power receiving unit G horizontal plane

Claims

1. A power supply system for a transport vehicle that supplies power to the transport vehicle in a non-contact manner, a power supply unit that is installed in an upright state with respect to a horizontal plane and supplies power to the transport vehicle; a power receiving unit that is provided on the transport vehicle in a state in which the power receiving unit stands on a horizontal plane and receives power supplied from the power supply unit when the power receiving unit is located opposite the power supply unit; A power supply system for a transport vehicle.

2. a gap adjustment unit provided in at least one of the power supply unit and the power receiving unit, the gap adjustment unit adjusting a gap between the power supply unit and the power receiving unit when the power supply unit and the power receiving unit are positioned opposite each other; The power supply system for a transportation vehicle according to claim 1 , further comprising:

3. The interval adjustment unit is provided in the power receiving unit, When the power supply unit and the power receiving unit are positioned opposite each other, an elastic member that is provided at a position opposite to the power supply unit across the power receiving unit and that applies pressure to the power receiving unit in a direction to bring the power receiving unit closer to the power supply unit; a spacer member extending from the power receiving portion toward the power supply portion to separate the power receiving portion from the power supply portion; The power supply system for a transportation vehicle according to claim 2 .

4. the gap adjustment unit is provided on the power supply unit, When the power supply unit and the power receiving unit are positioned opposite each other, an elastic member that is provided at a position opposite to the power receiving unit across the power supply unit and that applies pressure to the power supply unit in a direction to bring the power supply unit closer to the power receiving unit; a spacer member extending from the power supply unit toward the power receiving unit to separate the power supply unit from the power receiving unit; The power supply system for a transportation vehicle according to claim 2 .

5. 5. The power supply system for a transportation vehicle according to claim 3, wherein the elastic member is a spring member, and the spacer member has a guide wheel at a tip end thereof which is rotatable in the traveling direction of the transportation vehicle.

6. 6. The power supply system for a transport vehicle according to claim 5, further comprising a guide member for positioning the guide wheels in the vertical direction.

7. A power supply method for a transportation vehicle that supplies power to the transportation vehicle in a non-contact manner, comprising: a travel stopping step of stopping travel of the transport vehicle when a power receiving unit provided on the transport vehicle in a state where the power receiving unit stands on a horizontal surface is located opposite a power supply unit provided in a state where the power supply unit stands on the horizontal surface; a power supply step of supplying power from the power supply unit to the power receiving unit; A power supply method for a transportation vehicle comprising the steps of:

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