Power supply device

Abstract

To provide a power supply device that is able to remove with a simple configuration a foreign object.SOLUTION: A power supply device includes: a power supply coil installed on a ground surface or a floor surface of a parking area; a foreign-object removal unit installed on the power supply coil; a moving unit connected to the foreign-object removal unit, installed inside a wheel stopper of the parking area so as to be movable in a depth direction of the parking area, and configured to be moved by an automobile entering the parking area; and a return mechanism configured to return the moving unit to an original position.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power supply device that can remove foreign objects and safely supply power wirelessly to an electric vehicle. [Background technology]

[0002] Electric vehicles, which use large-capacity lithium-ion batteries as drive batteries and drive motors with the power stored in the drive batteries, are becoming more popular. Wireless power transfer, which transfers power wirelessly rather than via a power cable, has been put into practical use as a method of powering the drive batteries installed in electric vehicles.

[0003] In wireless power transfer, an electric vehicle must be moved so that its power transmission coil faces a power transfer coil installed in a space that the electric vehicle can access. Foreign objects can also enter the power transfer area due to wind or abandonment. If a magnetic foreign object exists between the power transfer coil and the opposing power transfer coil, the AC magnetic field generated by the power transfer coil is converted into heat by the foreign object, reducing power transfer efficiency and raising the temperature of the foreign object, posing a safety issue.

[0004] For this reason, wireless power transfer has been designed to stop power transfer when a foreign object is detected between the power transfer coil and the power transmission coil. However, if power transfer cannot be performed until the foreign object is removed once the foreign object is detected, power transfer opportunities will be lost for a long period of time. Patent Document 1 proposes removing the foreign object by tilting the cover of the power transfer coil or generating air with a blower when the foreign object is detected. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-059239 Summary of the Invention [Problem to be solved by the invention]

[0006] A configuration that specifically provides a mechanism for detecting foreign objects and an electrically operated foreign object removal device for removing foreign objects increases the complexity of the control of these mechanisms and the size of the device, resulting in increased costs.

[0007] An object of the present invention is to provide a power supply device that can remove foreign matter with a simple configuration. [Means for solving the problem]

[0008] A power supply device according to one embodiment of the present disclosure includes a power supply coil installed on the ground or floor of a parking area, a foreign object removal unit installed on the power supply coil, a moving unit connected to the foreign object removal unit, installed inside the wheel chocks of the parking area so as to be movable in the depth direction of the parking area and moved by vehicles entering the parking area, and a return mechanism that returns the moving unit to its original position.

[0009] In the power supply device disclosed herein, when an electric vehicle entering a parking area pushes the moving unit against the wheel chock, the foreign object removal unit that moves integrally with the moving unit removes foreign objects from the upper surface of the power supply coil. No specific mechanism or control is required for the foreign object removal unit. [Effects of the Invention]

[0010] According to the present disclosure, foreign objects on the power supply coil are automatically removed by parking the electric vehicle in a parking area. Neither a foreign object detection mechanism nor an electrically operated foreign object removal device is required, and foreign object removal can be achieved with a simple configuration. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view of a power supply device according to a first embodiment. [Figure 2] 4 is a schematic diagram illustrating foreign matter removal by a foreign matter removal unit of the power supply device according to the first embodiment. FIG. [Figure 3] FIG. 2 is a block diagram showing a configuration related to control of the power supply device. [Figure 4] 10 is a flowchart illustrating an example of a control procedure performed by a control unit. [Figure 5] FIG. 10 is a schematic perspective view of a power supply device according to a second embodiment. [Figure 6] 10 is a schematic diagram illustrating foreign matter removal by a foreign matter removal unit of a power supply device according to a second embodiment. FIG. [Figure 7] FIG. 10 is a schematic perspective view of a power supply device according to a third embodiment. [Figure 8] 10 is a schematic diagram illustrating foreign matter removal by a foreign matter removal unit of a power supply device according to a third embodiment. FIG. [Figure 9] FIG. 10 is a schematic perspective view of a power supply device according to a fourth embodiment. [Figure 10] FIG. 10 is a schematic diagram illustrating foreign matter removal by a foreign matter removal unit of a power supply device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present disclosure will be specifically described with reference to the drawings showing embodiments thereof.

[0013] (First embodiment) FIG. 1 is a schematic perspective view of a power supply device 1 of the first embodiment. The power supply device 1 includes a power supply coil 11 installed at the back of a parking area A, and a housing 12 surrounding the power supply coil 11. The housing 12 is made of aluminum, for example. The power supply coil 11 is installed on the ground or floor of the parking area A with its axis in the vertical direction. As shown in FIG. 1, the housing 12 has a flat rectangular parallelepiped shape. The power supply coil 11 is provided inside the housing 12.

[0014] The power supply device 1 includes a foreign object removal unit 13 that is a substantially flat plate that covers the upper surface of the housing 12 of the power supply coil 11. The foreign object removal unit 13 is a rectangular flat plate that covers the rectangular upper surface of the housing 12. The width of the foreign object removal unit 13 is substantially the same as the width of the housing 12. The foreign object removal unit 13 may have any shape that allows it to fit between both wheels of the electric vehicle and to slip under the electric vehicle. The foreign object removal unit 13 may be made of a durable non-magnetic material such as resin, and may be made of aluminum. The foreign object removal unit 13 need not be made of a magnetic material as long as it is configured to be sufficiently separated from the area above the power supply coil 11.

[0015] A moving part 14 is connected to the foreign object removal part 13. The moving part 14 is located inside the wheel chocks C of the parking area A and is approximately parallel to the wheel chocks C. The moving part 14 has a length in the width direction of the parking area A that allows it to be pushed by both wheels of the electric vehicle. The moving part 14 is, for example, in the shape of a square bar, as shown in FIG. 1. The length is at least longer than the distance between the two wheels of the electric vehicle, preferably longer than the outer width of the tires, and is long enough to allow both wheels of the electric vehicle entering the parking area A to come into contact with it simultaneously. The shape of the moving part 14 is not limited to a square bar, but may also be an M-shape with recesses where the two wheels come into contact. Casters or bearings are provided on one side of the moving part 14 facing the ground or floor to facilitate movement relative to the ground or floor. The moving part 14 is not limited to casters or bearings, and any other device can be used as long as it facilitates smooth movement between the moving part and the ground or floor.

[0016] The moving unit 14 is not limited to a configuration in which it is pushed into the tire of the electric vehicle, but may be a configuration in which it is pushed into a frame provided at the bottom of the electric vehicle.

[0017] The foreign object removal unit 13 is connected to one side surface of the moving unit 14 at approximately the center thereof. The foreign object removal unit 13 and the moving unit 14 move together in the vehicle length direction. The total length of the foreign object removal unit 13, the moving unit 14, and the parking area A in the depth direction is slightly longer than the distance from the rear side surface of the housing 12 of the power feeding coil 11 to the front side surface of the wheel chock C. Due to this length, even when the moving unit 14 is moved to the rearmost position relative to the wheel chock C, the front edge of the foreign object removal unit 13 is located on the top surface of the housing 12.

[0018] A return mechanism 15 that returns the moving unit 14 to its original position is provided between the wheel chock C side of the moving unit 14 and the wheel chock C. The return mechanism 15 may be an expandable body such as a spring, or may have a piston-like structure. The return mechanism 15 contracts while the moving unit 14 is pressed into and fixed to both front wheels or both rear wheels of the electric vehicle, and expands and returns to its original state when the fixation by the electric vehicle is loosened, causing the foreign object removal unit 13, which moves integrally with the moving unit 14, to return to a position covering the top surface of the housing 12.

[0019] FIG. 2 is a schematic diagram of foreign object removal by the foreign object removal unit 13 of the power supply device 1 of the first embodiment. FIG. 2 shows a side view of the power supply device 1. FIG. 2A shows the state when an electric vehicle has not entered parking area A. As shown in FIG. 2A, garbage, fallen leaves, etc. may fly into parking area A. FIG. 2B shows the state when the electric vehicle has entered parking area A and the moving unit 14 has started to move. As shown in FIG. 2B, when the tire T of the electric vehicle comes into contact with the moving unit 14, it pushes the moving unit 14 toward the wheel chock C.

[0020] FIG. 2C shows the state in which the tire T of the electric vehicle pushes the moving unit 14 into the wheel chock C. As shown in FIGS. 2B and 2C , when the moving unit 14 is pushed into the wheel chock C, the foreign object removal unit 13, which moves as a unit, moves toward the wheel chock C, and no dirt or fallen leaves remain on the top of the power supply coil 11 and its housing 12, which were previously covered. In this way, foreign objects are automatically removed when the electric vehicle enters the parking area. No electrically operated foreign object removal device, such as a driving lid or blower, is required. This reduces the risk of a decrease in the efficiency of power transmission from the power supply coil 11 to the power receiving coil of the electric vehicle, and improves safety.

[0021] The power supply device 1 may be provided with a detection unit 16 that detects when the moving unit 14 is pushed all the way in. The detection unit 16 may use, for example, a piezoelectric sensor to detect when the moving unit 14 abuts against the wheel stopper C, or may detect the expansion and contraction of the return mechanism 15.

[0022] 3 is a block diagram showing a configuration related to control of the power supply device 1. The power supply device 1 includes a control unit 100, a power supply device 101, and a communication circuit 102. The power supply device 101 is connected to the power supply coil 11 and a detection unit 16, and the control unit 100 controls ON / OFF of power supply from the power supply device 101 to the power supply coil 11.

[0023] The control unit 100 is configured using a processor and a memory. The control unit 100 is connected to the detection unit 16, and controls ON / OFF of power supply from the power supply device 101 to the power supply coil 11 depending on the state detected by the detection unit 16. As described above, the detection unit 16 is, for example, a piezoelectric sensor, and detects that the moving unit 14 has been pushed into the electric vehicle.

[0024] The communication circuit 102 realizes wireless communication with a power receiving device mounted on the electric vehicle. The communication circuit 102 communicates using Bluetooth (registered trademark), for example. The standard of wireless communication by the communication circuit 102 is not limited to Bluetooth. The communication circuit 102 may also perform wireless communication with other wireless communication devices, for example, devices mounted on the electric vehicle.

[0025] 4 is a flowchart showing an example of a control procedure performed by the control unit 100. While receiving power from a commercial power source via the power supply device 101, the control unit 100 repeatedly executes the following processing.

[0026] The control unit 100 determines whether the moving unit 14 is being pushed by the electric vehicle using the detection unit 16 (step S101).

[0027] If it is determined that the moving unit 14 is not being pushed by the electric vehicle (S101: NO), the control unit 100 returns the process to step S101 after a predetermined waiting time has elapsed.

[0028] If it is determined that the moving unit 14 is being pushed into the electric vehicle (S101: YES), the control unit 100 starts a communication connection with the power receiving device of the electric vehicle through the communication circuit 102 (step S102) and determines whether communication is possible (step S103). In S103, the control unit 100 may verify whether the communication partner is authentic using authentication information.

[0029] If it is determined that communication is possible (S103: YES), the control unit 100 starts power feeding from the power feeding coil 11 (step S104). Thereafter, the control unit 100 determines, using the detection unit 16, whether the moving unit 14 is being pushed by the electric vehicle and whether power feeding to the battery of the electric vehicle to be fed is required (step S105). If it is determined in step S105 that the moving unit 14 is in contact with the electric vehicle and power feeding is required (S105: YES), the control unit 100 continues power feeding and returns the process to S105.

[0030] If it is determined that the moving unit 14 is not pushed in or does not require power supply (S105: NO), the control unit 100 stops the power supply to the power supply coil 11 to terminate power supply (step S106), disconnects the communication connection (step S107), and ends the process. After that, the control unit 100 returns the process to step S101 and waits again until a new electric vehicle enters the parking area A.

[0031] In step S105, if the control unit 100 determines that the moving unit 14 is being pushed by the electric vehicle but is not in a state where power supply is required, the control unit 100 stops power supply (S106), but may maintain the communication connection so that power supply can be resumed.

[0032] If it is determined that communication is not possible (S103: NO), the control unit 100 stops communication (step S108), determines that the vehicle parked in parking area A is not a target for wireless charging (step S109), and ends the process. If it is determined in step S103 that communication is not possible, the process does not need to be resumed until the electric vehicle moves out of the corresponding parking area.

[0033] In this way, the power supply device 1 of this embodiment is capable of detecting that the electric vehicle has stopped and automatically starting power supply by using the mechanism of the moving unit 14 and the detection unit 16 that detects the pushing of the moving unit 14. Note that it is not essential to use the detection unit 16 to determine the timing to start power supply as shown in Figures 3 and 4. For example, the control unit 100 may execute a process to start power supply when an operation to start power supply is received from an operation unit provided in the power supply device 1.

[0034] (Second embodiment) 5 is a schematic perspective view of the power supply device 1 of the second embodiment. The hardware configuration and processing procedure of the power supply device 1 of the second embodiment are the same as those of the first embodiment, except for the configuration of the foreign matter removal unit 13 described below. Therefore, among the configurations of the power supply device 1 of the second embodiment, the configurations common to the first embodiment are assigned the same reference numerals and detailed description thereof will be omitted.

[0035] 5, in the power supply device 1 of the second embodiment, the foreign object removal unit 13 has a rectangular flat plate shape similar to that of the first embodiment, and has a barb 131 erected on the front edge along the direction perpendicular to the moving direction. This makes it possible to more reliably prevent foreign objects that were on the flat-plate foreign object removal unit 13 from remaining on the power supply coil 11 by moving the foreign object removal unit 13 integrally with the moving unit 14.

[0036] FIG. 6 is a schematic diagram of foreign object removal by the foreign object removal unit 13 of the power supply device 1 according to the second embodiment. FIG. 6 shows a side view of the power supply device 1. FIG. 6A shows a state when an electric vehicle has not entered parking area A. As shown in FIG. 6A, trash may fly into or be abandoned in parking area A. The trash may include empty cans, which are rolling and magnetic. FIG. 6B shows a state in which the electric vehicle has entered parking area A and the moving unit 14 has begun to move. FIG. 6C shows a state in which the tire T of the electric vehicle has pushed the moving unit 14 into the wheel chock C. As shown in FIGS. 6B and 6C, when the moving unit 14 is pushed into the wheel chock C, the foreign object removal unit 13, which moves as a unit, moves toward the wheel chock C. At this time, as shown in FIG. 6C, the rolling trash is also collected by the barb 131 provided on the foreign object removal unit 13, and no trash or fallen leaves remain on the upper part of the power supply coil 11 and its housing 12, which were previously covered. This reduces the risk of a decrease in the efficiency of power transmission from the power supply coil 11 to the power receiving coil of the electric vehicle, and improves safety.

[0037] (Third embodiment) 7 is a schematic perspective view of a power supply device 1 of the third embodiment. The configuration of the power supply device 1 of the third embodiment is the same as that of the first embodiment except for the foreign matter removal unit 13. Therefore, among the configurations of the power supply device 1 of the third embodiment, the configurations common to the first embodiment are assigned the same reference numerals and detailed description thereof will be omitted.

[0038] 7, the foreign object removal unit 13 in the power supply device 1 according to the third embodiment is made up of a brush 132 and a handle 133. The foreign object removal unit 13 does not cover the upper surface of the housing 12 of the power supply coil 11. However, it can remove rolling foreign objects, is lightweight, and allows the brush 132 to be easily replaced, making it easy to maintain. The brush 132 has a width that covers the width of the housing 12 of the power supply coil 11, and the handle 133 has a length that corresponds to the length of the housing 12 of the power supply coil 11 in the depth direction.

[0039] FIG. 8 is a schematic diagram of foreign object removal by the foreign object removal unit 13 of the power supply device 1 of the third embodiment. FIG. 8 shows a side view of the power supply device 1. FIG. 8A shows a state when an electric vehicle has not entered parking area A. As shown in FIG. 8A, trash may fly into or be abandoned in parking area A. The trash may include empty cans, which are rolling and magnetic. FIG. 8B shows a state in which the electric vehicle has entered parking area A and the moving unit 14 has begun to move. FIG. 8C shows a state in which the tire T of the electric vehicle has pushed the moving unit 14 into the wheel chock C. As shown in FIGS. 8B and 8C, when the tire T of the electric vehicle pushes the moving unit 14 toward the wheel chock C, the foreign object removal unit 13, which moves as a unit, moves toward the wheel chock C. At this time, the brush 132 also collects the rolling trash, and no trash or fallen leaves remain on the upper part of the power supply coil 11 and its housing 12, which were previously covered. This reduces the risk of a decrease in the efficiency of power transmission from the power supply coil 11 to the power receiving coil of the electric vehicle, and improves safety.

[0040] (Fourth embodiment) 9 is a schematic perspective view of a power supply device 1 according to the fourth embodiment. The hardware configuration and processing procedure of the power supply device 1 according to the fourth embodiment are the same as those of the first embodiment, except for the configurations of the foreign matter removal unit 13, the moving unit 14, and the return mechanism 15. Therefore, among the configurations of the power supply device 1 according to the fourth embodiment, the configurations common to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0041] 9, in the power supply device 1 of the fourth embodiment, the foreign object removal unit 13 has a rectangular flat plate shape like that of the first embodiment, but is twice as long in the depth direction and has a window 134 on the front side. In addition, a moving unit 14 is also connected to the front side of the rectangular flat plate-shaped foreign object removal unit 13. The foreign object removal unit 13 and the two moving units 14 move together in the depth direction of the parking area A.

[0042] 9, the return mechanism 15 of the power supply device 1 of the fourth embodiment is composed of a fixed part 151, a wheel stopper C, and two moving parts 14. When the moving part 14 on the rear side abuts against the wheel stopper C, it cannot move any further rearward, and similarly, the moving part 14 on the front side is fixed by the vertical surface on the rear side of the fixed part 151 and cannot move any further forward. The foreign object removal part 13 and the two moving parts 14 move back and forth in the depth direction together between the fixed part 151 and the wheel stopper C.

[0043] The fixed part 151 has a slope that gradually increases from the height of the ground or floor surface to the height of the moving part 14 on the front side. The slope of the fixed part 151 makes it easier for the tires of the electric vehicle to jump over the moving part 14 on the front side when the electric vehicle enters the parking area A.

[0044] When the foreign object removal unit 13 and the two moving units 14 abut against the fixed unit 151 and are positioned on the front side, which is the initial position, the foreign object removal unit 13 covers the housing 12 of the power feed coil 11. When the foreign object removal unit 13 and the two moving units 14 abut against the ring stopper C and are positioned on the rear side, the window 134 of the foreign object removal unit 13 is positioned above the housing 12 of the power feed coil 11, creating a space above the power feed coil 11.

[0045] FIG. 10 is a schematic diagram of foreign object removal by the foreign object removal unit 13 of the power supply device 1 of the fourth embodiment. FIG. 10 shows a side view of the power supply device 1. FIG. 10A shows a state in which an electric vehicle starts to enter parking area A and a tire T climbs the slope of the fixed portion 151. Before the electric vehicle enters parking area A, as shown in FIG. 10A, garbage, fallen leaves, and the like may fly into parking area A. FIG. 10B shows a state in which the electric vehicle enters parking area A and the moving portion 14 starts to move. As shown in FIG. 10B, the tire T of the electric vehicle passes over the moving portion 14 on the front side and abuts against the moving portion 14 on the back side, pushing this moving portion 14 toward the wheel chock C.

[0046] FIG. 10C shows a state in which the tire T of the electric vehicle has pushed the moving unit 14 at the rear side into the wheel chock C. The foreign object removal unit 13, which moves integrally with the moving unit 14, moves toward the wheel chock C. In the state shown in FIG. 10C , as described above, the window 134 of the foreign object removal unit 13 is located above the housing 12 of the power feeding coil 11, creating space above the power feeding coil 11. Dust and fallen leaves move along with the foreign object removal unit 13 and do not remain above the housing 12 of the power feeding coil 11. This reduces the risk of a decrease in the efficiency of power transmission from the power feeding coil 11 to the power receiving coil of the electric vehicle, and improves safety.

[0047] 10D and 10E show the movement of the foreign object removal unit 13 and the two moving units 14 when the electric vehicle leaves parking area A. In the fourth embodiment, the return mechanism 15 does not employ a configuration in which the rear moving unit 14 returns to its original position by the return force of a spring or the like, and instead the front moving unit 14 is returned by being pushed by the tire T of the electric vehicle. FIG. 10D shows the state in which the tire T of the electric vehicle abuts against the front moving unit 14 and pushes it forward when leaving parking area A. FIG. 10E shows the state in which the tire T pushes the front moving unit 14 up to the vertical surface of the fixed unit 151. As a result, the foreign object removal unit 13 and the two moving units 14 return to their original positions.

[0048] In the fourth embodiment, foreign objects are also automatically removed when the electric vehicle enters the parking area, which reduces the risk of a decrease in the efficiency of power transmission from the power supply coil 11 to the power receiving coil of the electric vehicle and improves safety. The edge of the window 134 of the foreign object removal unit 13 in the fourth embodiment may be provided with a tab as shown in the second embodiment to prevent foreign objects from falling in.

[0049] The embodiments disclosed above are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0050] 1 Power supply device 11 Power supply coil 12. Case 13 Foreign matter removal section 131 Return 132 Brushes 133 patterns 14 Moving section 15 Return mechanism 16. Detection unit 100 control section

Claims

1. a power supply coil installed on the ground or floor of the parking area; a foreign matter removal unit disposed above the power supply coil; a moving unit that is connected to the foreign object removal unit, that is installed inside the wheel chocks of the parking area and that is movable in the depth direction of the parking area, and that is moved by automobiles entering the parking area; a return mechanism that returns the moving part to its original position; A power supply device comprising:

2. the moving portion has a width that allows it to be pushed by the vehicle entering the parking area, the foreign object removal unit has a shape that allows it to slip under the vehicle, The total length of the foreign object removal unit and the moving unit, which move together, in the depth direction of the parking area is longer than the length from an inner surface of a wheel chock of the parking area to the back side of the power supply coil. The power supply device according to claim 1 .

3. The foreign matter removal unit is a substantially flat plate that covers the upper surface of the housing of the power supply coil. The power supply device according to claim 1 .

4. A barb is provided on the upper surface of the foreign substance removal section in a direction perpendicular to the moving direction. The power supply device according to claim 3 .

5. The foreign matter removal unit has a brush at its bottom that sweeps the top surface of the housing of the power supply coil. The power supply device according to claim 1 .

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