Contactless charging system

Abstract

To provide a contactless charging system that can perform contactless charging without using wireless communication. [Solution] The contactless charging system of the present invention is a contactless charging system that charges a power storage device by non-contacting the transmission of power from the primary transmission coil of a power transmission device to the primary receiving coil of a power receiving device, and comprises a protective cover that is openable and closable on the power receiving device, an actuator that is electrically connected to the primary receiving coil and opens and closes the protective cover, a secondary transmission coil provided on the protective cover and electrically connected to the primary receiving coil so as to be movable together with the protective cover, a secondary receiving coil provided on the power transmission device so as to face the secondary transmission coil when the opening of the protective cover is complete, and a current sensor that detects the current flowing through the secondary receiving coil. The current sensor detects the current flowing through the secondary receiving coil, which has been non-contactually received from the secondary transmission coil, and detects that the opening of the protective cover is complete.

Description

Technical Field

[0001] The present invention relates to a non-contact charging system.

Background Art

[0002] In Patent Document 1, by performing wireless communication between a charging device mounted on a vehicle and a power supply device provided on the ground, when the parking of the vehicle is completed and the charging device is located above the power supply device, it is detected that non-contact charging is possible, and power is supplied non-contact from the power supply coil of the power supply device to the power receiving coil of the charging device, and a non-contact charging system for charging a secondary battery mounted on the vehicle and electrically connected to the charging device is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the non-contact charging system disclosed in Patent Document 1, since construction of a complex system etc. is necessary for wireless communication, there is room for improvement.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a non-contact charging system capable of performing non-contact charging without performing wireless communication.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the contactless charging system according to the present invention is a contactless charging system that transmits power in a contactless manner from a primary power transmission coil of a power transmission device installed on the ground to a primary power receiving coil of a power receiving device installed on a vehicle, and charges a power storage device installed on the vehicle and electrically connected to the power receiving device, and is characterized by comprising: a protective cover that is openable and closable with respect to the power receiving device; an actuator electrically connected to the primary power receiving coil and used for opening and closing the protective cover; a secondary power transmission coil provided on the protective cover and electrically connected to the primary power receiving coil so as to be movable together with the protective cover; a secondary power receiving coil installed on the power transmission device so as to face the secondary power transmission coil when the opening of the protective cover is completed; and a current sensor for detecting the current flowing through the secondary power receiving coil. The system is characterized by detecting the completion of the opening of the protective cover by detecting the current flowing through the secondary power receiving coil, which has been received in a contactless manner from the secondary power transmission coil, using the current sensor. [Effects of the Invention]

[0007] The contactless charging system according to the present invention has the effect of enabling contactless charging when the vehicle is parked and the receiving device is positioned above the power transmission device, without requiring wireless communication between the power transmission device and the power receiving device, by detecting when the protective cover has been opened. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows an example of a schematic configuration of a contactless charging system according to an embodiment. [Figure 2] Figure 2 shows the opening operation of the protective cover provided on the power receiving device. [Figure 3] Figure 3 shows the protective cover in its fully opened state. [Figure 4] Figure 4 is a graph showing the current value of the secondary power receiving coil detected by the current sensor. [Modes for carrying out the invention]

[0009] The following describes embodiments of the contactless charging system according to the present invention. However, the present invention is not limited to these embodiments.

[0010] Figure 1 is a diagram showing an example of a schematic configuration of a contactless charging system 1 according to an embodiment.

[0011] The contactless charging system 1 according to this embodiment comprises a power transmission device 2 installed in a parking space on the ground and a power receiving device 3 installed in a vehicle. The contactless charging system 1 is a system that charges a battery, which is a power storage device mounted in the vehicle and electrically connected to the primary power receiving coil 31 via a power line, by transmitting power from the primary power transmission coil 21 of the power transmission device 2 to the primary power receiving coil 31 of the power receiving device 3 in a contactless manner when the vehicle is parked in the parking space such that the power receiving device 3 is positioned above the power transmission device 2.

[0012] The power transmission device 2 comprises a housing 20, a primary power transmission coil 21, a secondary power receiving coil 22, a power supply unit 23, and a current sensor 24. The primary power transmission coil 21, the secondary power receiving coil 22, the power supply unit 23, and the current sensor 24 are located inside the housing 20. The primary power transmission coil 21 is positioned inside the housing 20 so as to face the primary power receiving coil 31 of the power receiving device 3 installed in a vehicle parked in a parking space. It transmits power to the primary power receiving coil 31 of the power receiving device 3 installed in the vehicle without contact. The power supply unit 23 is electrically connected to the primary power transmission coil 21, and AC power of a predetermined frequency is supplied from the power supply unit 23 to the primary power transmission coil 21. In this way, when AC power is supplied from the power supply unit 23 to the primary transmission coil 21, a magnetic field is formed between the primary transmission coil 21 and the primary receiving coil 31, and power is transmitted non-contact from the primary transmission coil 21 to the primary receiving coil 31 through this magnetic field.

[0013] The power receiving device 3 comprises a housing 30, a primary power receiving coil 31, a secondary power transmission coil 32, and a protective cover 33. The primary power receiving coil 31 is located inside the housing 30. The protective cover 33 is provided on the power receiving device 3 (housing 30) so that it can be opened and closed by moving (sliding) along the bottom surface of the housing 30.

[0014] Figure 2 shows the opening operation of the protective cover 33 provided on the power receiving device 3.

[0015] As shown in Figure 2, in the power receiving device 3, a cover drive motor 35, which is an actuator for opening and closing the protective cover 33, is provided in the housing 30. The cover drive motor 35 is electrically connected to the primary power receiving coil 31 via a power line separate from the secondary power transmission coil 32. In addition, a current sensor 34 for detecting the current flowing through the primary power receiving coil 31 is electrically connected to the power line electrically connecting the primary power receiving coil 31 and the cover drive motor 35.

[0016] A disc-shaped member 36 is pivotally supported on the output shaft 35a of the cover drive motor 35 to provide power for moving the protective cover 33. The disc-shaped member 36 is, for example, a pinion gear with external teeth formed on its outer circumference, and meshes with a rack gear provided on the side of the protective cover 33 in the direction of movement. The protective cover 33 is moved by rotating the disc-shaped member 36 with the driving force from the cover drive motor 35 while the pinion gear and rack gear are meshed. The disc-shaped member 36 may, for example, have a rubber material, which is a high-friction material, on its outer circumference. The protective cover 33 may be moved by the frictional force generated between the rubber material and the side of the protective cover 33 when the disc-shaped member 36 is rotated with the driving force from the cover drive motor 35 while the rubber material on the outer circumference of the disc-shaped member 36 is in contact with the side of the protective cover 33.

[0017] The secondary power transmission coil 32 is built into the downstream end of the protective cover 33 in the direction of its movement. The secondary power transmission coil 32 is electrically connected to the primary power receiving coil 31 via a power line so as to move together with the protective cover 33 in accordance with the opening and closing operation of the protective cover 33 relative to the housing 30. Furthermore, when the protective cover 33 is fully open relative to the housing 30 and the opening of the protective cover 33 is complete, the secondary power transmission coil 32 can reach a position opposite the secondary power receiving coil 22 provided in the power transmission device 2, i.e., above the secondary power receiving coil 22.

[0018] Figure 3 shows the state after the protective cover 33 has been fully opened.

[0019] In the contactless charging system 1 according to this embodiment, with a vehicle parked in a parking space and the power receiving device 3 positioned above the power transmission device 2, AC power is supplied from the power supply unit 23 of the power transmission device 2 to the primary power transmission coil 21, generating a magnetic field from the primary power transmission coil 21 toward the primary power receiving coil 31 of the power receiving device 3. As a result, the magnetic field formed between the primary power transmission coil 21 of the power transmission device 2 and the primary power receiving coil 31 of the power receiving device 3 causes current to flow from the primary power transmission coil 21 to the primary power receiving coil 31, which receives power from the primary power transmission coil 21 in a contactless manner. The current flowing through the primary power receiving coil 31 is detected by the current sensor 34, and based on the detection result, a control device installed in the vehicle (power receiving device 3), for example, detects that the vehicle has been parked in the parking space. At the same time, a portion of the power received by the primary power receiving coil 31 is supplied to the cover drive motor 35 via the power line, so that the cover drive motor 35 is driven and the protective cover 33 is opened.

[0020] In the contactless power charging system 1 according to the embodiment, since part of the power received by the primary power receiving coil 31 is supplied to the secondary power transmitting coil 32 via a power line, a magnetic field is generated from the secondary power transmitting coil 32 toward the power transmitting device 2 side. Then, as the opening operation of the protection cover 33 is completed, when the opening of the protection cover 33 is completed, the secondary power transmitting coil 32 of the power receiving device 3 reaches above the secondary power receiving coil 22 of the power transmitting device 2 (a position facing the secondary power receiving coil 22). As a result, due to the magnetic field formed between the secondary power transmitting coil 32 and the secondary power receiving coil 22, a current flows through the secondary power receiving coil 22 that has received power non - contact from the secondary power transmitting coil 32. Then, the current flowing through this secondary power receiving coil 22 is detected by the current sensor 24. As shown in FIG. 4, the current value of the secondary power receiving coil 22 detected by the current sensor 24 increases from during the operation of the protection cover 33 to the timing when the opening of the protection cover 33 is completed, at which time the secondary power receiving coil 22 can receive power from the secondary power transmitting coil 32. Therefore, when the current sensor 24 detects the current of the secondary power receiving coil 22, based on the detection result, for example, the control device provided in the power transmitting device 2 detects that the opening of the protection cover 33 is completed.

[0021] As described above, in the contactless power charging system 1 according to the embodiment, by detecting that the opening of the protection cover 33 is completed, without performing wireless communication between the power transmitting device 2 and the power receiving device 3 (vehicle), it can be detected by the control device of the power transmitting device 2 that the parking of the vehicle is completed and the power receiving device 3 is located above the power transmitting device 2 and is in a state where contactless power charging is possible. Then, based on this detection, in the power transmitting device 2, the control device controls the power supply device 23 and the like so that a predetermined charging power for charging the vehicle battery is output, and power is transmitted non - contact from the primary power transmitting coil 21 of the power transmitting device 2 to the primary power receiving coil 31 of the power receiving device 3, enabling contactless power charging (charging of the battery).

Explanation of Reference Numerals

[0022] 1 Contactless power charging system 2 Power transmitting device 3 Power receiving device 20, 30 Housing 21 Primary transmission coil 22 Secondary receiving coil 23 Power supply 24 Current Sensor 31 Primary receiving coil 32 Secondary transmission coil 33 Protective cover 34 Current Sensor 35 Cover drive motor 35a Output shaft 36 Disc-shaped member

Claims

[Claim 1] A contactless charging system that transmits power from a primary power transmission coil of a power transmission device installed on the ground to a primary power receiving coil of a power receiving device installed on a vehicle, and charges a power storage device installed on the vehicle and electrically connected to the power receiving device, A protective cover is provided to the power receiving device so as to be openable and closable, The actuator is electrically connected to the primary power receiving coil and is used to open and close the protective cover. A secondary power transmission coil is provided on the protective cover and is electrically connected to the primary power receiving coil so as to be movable together with the protective cover, With the protective cover fully opened, the secondary receiving coil is provided in the power transmission device so as to face the secondary power transmission coil, A current sensor for detecting the current flowing through the secondary power receiving coil, It is equipped with, The current flowing through the secondary receiving coil, which is non-contactually powered from the secondary power transmission coil, is detected by the current sensor, thereby detecting that the opening of the protective cover has been completed. A contactless charging system characterized by the following features.

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