WO2012132242A1

WO2012132242A1 - Contactless power-reception device

Info

Publication number: WO2012132242A1
Application number: PCT/JP2012/001523
Authority: WO
Inventors: 宮下　功寛; 悟天利
Original assignee: パナソニック株式会社
Priority date: 2011-03-31
Filing date: 2012-03-06
Publication date: 2012-10-04
Also published as: JP2014112573A

Abstract

A contactless power-reception device (10) is attached to the bottom of a vehicle (40) and receives power wirelessly from a contactless power-feed device (20). Said contactless power-reception device (10) has: a power-reception coil (102) for receiving power wirelessly from the power-feed device (20); a first wireless circuit board (107) and first communication antenna (106) for performing short-range wireless communication with the contactless power-feed device (20); a magnetic-field blocking member (104) comprising a conductor disposed on the vehicle side of the power-reception coil (102); a metal frame (30) attached to the top of the contactless power-reception device (10) and the bottom of the vehicle (40); and an insulation member (105) that is interposed between the magnetic-field blocking member (104) and the metal frame (30) and electrically insulates said magnetic-field blocking member (104) and metal frame (30) from each other.

Description

Non-contact power receiving device

The present invention relates to a contactless power receiving apparatus in a contactless charging system for charging a secondary battery of an electric propulsion vehicle in a contactless manner, for example.

First, an example of a non-contact charging system will be described. In the non-contact charging system, in order to charge a battery installed in an electric propulsion vehicle represented by an electric vehicle or a plug-in hybrid vehicle, a non-contact power feeding device installed on the ground based on the mutual induction action of electromagnetic induction (Hereinafter referred to as “power feeding device”) transmits power in a non-contact manner to a non-contact power receiving device (hereinafter referred to as “power receiving device”) attached to the chassis of the electric propulsion vehicle.

In such a contactless charging system, when power is transmitted in a contactless manner, it is necessary to transmit information such as a charging instruction and required power between the power feeding device and the power receiving device. For this purpose, the power feeding device and the power receiving device include an antenna for short-range wireless communication (see, for example, Patent Documents 1 and 2).

For example, the signal transmission coil communication device described in Patent Document 1 is used as a communication device of a non-contact charging system for electric propulsion vehicles. This non-contact charging system includes an antenna coil that is opposed to each other through a small gap space at the time of communication, and is formed in a symmetrical shape in a power feeding device and a power receiving device. The antenna coil has, for example, a substantially 8-character shape or a loop shape. Alternatively, the antenna coil is configured so that the antenna wires are orthogonal to each other on the plane of the planar magnetic body that is wound around the planar magnetic body and faces the power feeding device or the power receiving device. The antenna coil is disposed, for example, in a central space between the power transmission coil and the power reception coil.

JP 2008-288889 A JP 2006-345588 A

By the way, when the power receiving device is mounted on the electric propulsion vehicle, the wireless communication performance between the power feeding device and the power receiving device may be deteriorated depending on the mounting position and mounting method. It is necessary to mount the power receiving device on the electric propulsion vehicle in consideration of the wireless communication performance not being deteriorated.

Therefore, an object of the present invention is to provide a non-contact power receiving apparatus that can suppress a decrease in wireless communication performance.

In order to achieve the above object, the present invention is configured as follows.

According to an aspect of the present invention, a non-contact power receiving device that is attached to a lower portion of a vehicle and receives a non-contact power supply from the non-contact power feeding device, the non-contact power receiving device receiving power from the non-contact power feeding device A power receiving coil, a wireless circuit board and a communication antenna for performing short-range wireless communication with the non-contact power feeding device, a magnetic field shielding member made of a conductor disposed on a vehicle side of the power receiving coil, and the non-contact power receiving A metal frame attached to an upper part of the apparatus and attached to a lower part of the vehicle; an insulating member interposed between the magnetic field shielding member and the metal frame to electrically insulate the magnetic field shielding member and the metal frame; A non-contact power receiving device is provided.

According to the present invention, by electrically insulating the magnetic field shielding member and the metal frame by the insulating member, the current induced in the magnetic field shielding member by the non-contact power supply from the non-contact power supply device to the non-contact power receiving device. However, it is suppressed that it flows into a metal frame. Thereby, generation | occurrence | production of the magnetic field which arises when an electric current flows into a metal frame from a magnetic field shielding member can be suppressed. As a result, it is possible to suppress deterioration in wireless communication performance between the wireless circuit board and the communication antenna and the non-contact power feeding device.

These aspects and features of the present invention will become apparent from the following description taken in conjunction with the preferred embodiments with reference to the accompanying drawings. In this drawing,
Schematic diagram showing a non-contact charging system according to the present invention The figure which shows the inside of the electric power receiving apparatus and electric power feeding apparatus which are shown in FIG. Detailed view of the inside of the power receiving device of FIG. Detailed view of the inside of the power supply device of FIG. Detailed view of the metal frame shown in FIG. 1 is a schematic diagram showing an example of a wireless communication system mounted on the electric propulsion vehicle shown in FIG. Schematic diagram showing an example of a wireless communication system that performs in-vehicle-in-vehicle communication mounted on the electric propulsion vehicle shown in FIG. The figure which shows the attachment state of the power receiving apparatus and metal frame of a comparative example The figure which shows the loop electric current and magnetic field which generate | occur | produce when a metal frame is connected to the power receiving apparatus of the comparative example shown in FIG. The figure which shows the loop electric current and magnetic field which generate | occur | produce when the metal frame of a different shape is connected to the power receiving apparatus of a comparative example The figure which shows another connection method of a magnetic field shielding member and an insulation member

FIG. 1 is a schematic diagram showing a non-contact charging system S according to the present invention. As shown in FIG. 1, the non-contact charging system S includes a non-contact power feeding device (hereinafter referred to as “power feeding device”) 20 and a non-contact power receiving device (hereinafter referred to as “power receiving device”) 10. ing. This non-contact charging system S is used, for example, for charging an electric propulsion vehicle (hereinafter referred to as “vehicle”) 40. In this case, the power receiving device 10 is mounted on the vehicle 40, and the power feeding device 20 is installed on the ground, for example. However, the power supply device 20 is not limited thereto, and may be configured to be buried in a parking space, for example, or to be movable below the vehicle 4.

FIG. 2 is a diagram schematically showing the inside of the power receiving device 10 and the power feeding device 20 shown in FIG. FIG. 2 illustrates a state where the power receiving device 10 and the power feeding device 20 are arranged to face each other, that is, a state in which power is supplied from the power feeding device 20 to the power receiving device 10 in a contactless manner.

FIG. 3 is a diagram showing details of the inside of the power receiving device 10 of FIG. 3A is a top view of the power receiving device 10, FIG. 3B is a side view of the power receiving device 10 viewed from the side of the vehicle 40, and FIG. 3C is a power receiving device 10 viewed from the rear of the vehicle 40. FIG. FIG. 4 is a diagram showing in detail the inside of the power feeding device 20 of FIG. 4A is a top view of the power feeding device 20, FIG. 4B is a side view of the power feeding device 20 viewed from the side of the vehicle 40, and FIG. It is the front view of the electric power feeder 20 seen from.

As shown in FIGS. 2 and 3, the power receiving device 10 includes a load circuit 101, a power receiving coil 102, a ferrite 103, a magnetic field shielding member 104 made of a conductor, an insulating member 105, and a first communication antenna. 106, a first wireless circuit board 107, and a first antenna feed line 108.

The power receiving coil 102 generates electric power by receiving a magnetic field generated by a power transmission coil 108 of the power feeding device 20 described later, that is, receives power from the power feeding device 20 in a non-contact manner. The load circuit 101 includes a rechargeable battery that is charged with power generated by the power receiving coil 102, a rectifier circuit that supplies the power generated by the power receiving coil 102 to the rechargeable battery, and the like.

The ferrite 103 and the magnetic shielding member 104 are disposed on the vehicle side of the power receiving coil 102. As a result, a magnetic field generated by a power transmission coil 108 of the power supply device 20 described later is prevented from spreading to the vehicle side of the power reception coil 102.

The insulating member 105 is a member made of an insulating material, and is disposed on the vehicle side of the magnetic shielding member 104. As shown in FIG. 2, the insulating member 105 is fixed to a portion of the magnetic field shielding member 104 facing the vehicle 40 by connecting members 115 (a) to 115 (d) such as bolts.

As shown in FIG. 4, the power feeding device 20 includes a power transmission coil 109, a metal base 110, a second communication antenna 111, a second wireless circuit board 112, a second antenna power supply line 113, And a high-frequency power source 114.

The high frequency power supply 114 outputs high frequency power to the power transmission coil 109. The power transmission coil 109 is connected to a high frequency power source 114 and generates a high frequency magnetic field when high frequency power is supplied from the high frequency power source 114.

The first communication antenna 106 of the power receiving apparatus 10 and the second communication antenna 111 of the power supply apparatus 20 exchange signals (perform short-range wireless communication). For example, a signal for detecting misalignment between the power transmission coil 109 and the power receiving coil 102 or a signal for synchronizing control of the power feeding device 20 and the power receiving device 10 is the first communication antenna 106 and the second communication. The data is exchanged with the antenna 111 for use.

The first communication antenna 106 is a loop antenna that transmits a magnetic field corresponding to a signal. The first communication antenna 106 is also disposed in the vicinity of the power receiving coil 102 and is electrically connected to the first radio circuit board 107 via the first antenna feed line 108. On the other hand, the second communication antenna 111 is a loop antenna that receives the magnetic field generated by the first communication antenna 106. The second communication antenna 111 is also disposed in the vicinity of the power transmission coil 109 and is electrically connected to the second wireless circuit board 112 via the second antenna feed line 113.

Note that the first communication antenna 106 may receive a magnetic field, and the second antenna 111 may transmit the magnetic field.

Further, the first communication antenna 106 and the second communication antenna 111 are not limited to a loop shape, and may be a linear shape or a plate shape.

As shown in FIG. 2, the power receiving device 10 is mounted (attached) to the lower portion of the vehicle 40 via the metal frame 30. FIG. 5 is a detailed view of the metal frame 30. 5A is a top view of the metal frame 30, FIG. 5B is a side view of the metal frame 30 viewed from the side of the vehicle 40, and FIG. It is the front view of the metal frame 30 seen from.

The metal frame 30 is for absorbing an impact applied to the power receiving device 10 due to a rear-end collision with a moving body that has moved from the rear of the vehicle 40, or a collision with a stone or a wheel stop during traveling or parking.

Further, as shown in FIG. 2, the metal frame 30 is for attaching the power receiving device 10 to the lower part of the vehicle 40. The metal frame 30 is attached to the upper part of the power receiving device 10 and attached to the lower part of the vehicle 40. Specifically, the power receiving apparatus 10 is attached to the metal frame 30 in a state where the magnetic field shielding member 104 and the metal frame 30 are electrically insulated by the insulating member 105 interposed between the magnetic field shielding member 104 and the metal frame 30. It has been. In order to facilitate the work of mounting the power receiving device 10 on the vehicle 40, the power receiving device 10 and the metal frame 30 are preferably integrated.

As shown in FIG. 5, the metal frame 30 has a frame shape and is composed of four square bars 401 (a) to 401 (d). A square bar 401 (b) extending in the width direction of the vehicle 40 is connected between the ends of the square bars 401 (c) and 401 (d) extending in parallel to the front-rear direction of the vehicle 40 on the front side of the vehicle 40. Yes. The square bar 401 (a) is connected to the lower part of the rear side end of the vehicle 40 of the square bars 401 (c) and 401 (d). Further, connecting members 114 (a) to 114 (d) (see FIG. 2) such as bolts for connecting the power receiving apparatus 10 and the vehicle 40 pass through the square bars 401 (c) and 401 (d). Through holes 402 (a) to 402 (d) are formed. The through holes 402 (a) to 402 (d) preferably have long hole cross sections so that the power receiving device 10 can be attached to different types of vehicles 40.

Further, as shown in FIG. 1, since the vehicle 40 travels with the power receiving device 10 suspended, the metal frame 30 needs to have strength that can withstand this. Therefore, the metal frame 30 is made of a metal material such as aluminum or iron. Furthermore, the metal frame 30 mounted on the vehicle 40 is preferably as light as possible. For example, the square bars 401 (a) to 401 (d) of the metal frame 30 are made hollow and connected to each other by welding or screws. Further, the square bars 401 (a) to 401 (d) may be connected so that the internal spaces of the square bars 401 (a) to 401 (d) are communicated with each other.

Further, as shown in FIG. 2, a third communication antenna 116 is mounted on the vehicle to which the power receiving device 10 is attached. The third communication antenna 116 is connected to the third wireless circuit board 117 via the third antenna feed line 118 and is arranged on the inner side or the outer side of the vehicle 40. As shown in FIG. 6, the third antenna 116 communicates with an external fourth communication antenna 501. The fourth communication antenna 501 is connected to the fourth circuit board 502 via the fourth antenna feed line 503. In this case, the third antenna 116 is, for example, a transmission antenna for a smart entry system or a reception antenna for a terrestrial digital TV.

The third communication antenna 116 communicates with the fifth communication antenna 601 in the vehicle as shown in FIG. The fifth communication antenna 601 is connected to the fifth circuit board 602 via the fifth antenna feed line 603. In this case, the third antenna 116 in FIG. 7 is, for example, an antenna for Bluetooth (registered trademark) or a wireless LAN (Local Area Network) of a short-range wireless system.

According to such a configuration, the signal (current) output from the first wireless circuit board 107 flows to the loop-shaped first communication antenna 106 made of a conductor. A magnetic field is generated by the current flowing in the loop portion. The generated magnetic field is received by the second communication antenna 111. At this time, a part of the magnetic field induces the magnetic shielding member 105, and a current flows through the magnetic shielding member 105.

FIG. 8 shows a state in which the power receiving device 50 of the comparative example that does not include the insulating member 105 is attached to the metal frame 30. The power receiving device 50 of the comparative example has the same configuration as that of the power receiving device 10 except that the insulating member 105 is not provided.

As shown in FIG. 8, the power receiving device 50 of the comparative example is attached to the metal frame 30 in a state where the magnetic field shielding member 104 and the metal frame 30 are in contact with each other. Therefore, the magnetic field shielding member 104 and the metal frame 30 are electrically connected. Therefore, when a current is induced in the magnetic field shielding member 104 as described above, the current flows from the magnetic field shielding member 104 to the metal frame 30.

Then, as shown in FIG. 9, a loop current I for generating the magnetic field H flows. The loop current I flows along the opening L formed by the power receiving device 50 and the metal frame 30. Specifically, the opening L is formed by a part of the square bar 401 (a), a part of the square bar 401 (c), a part of the square bar 401 (d), and the magnetic field shielding member 104 of the power receiving device 50. Is done.

As shown in FIG. 9, when a loop current I flows along the opening L and a magnetic field H is generated along with this, the wireless communication performance between the first communication antenna 106 and the second communication antenna 111 is reduced. descend. Further, the magnetic field H also deteriorates the wireless communication performance between the third communication antenna 116 and the fourth communication antenna 501 (or the fifth communication antenna 601). When the frequency of the magnetic field H generated by the loop current I is substantially the same as the frequency used in wireless communication, the magnetic field distribution changes between the antennas due to the magnetic field H, which affects the reception level of the antenna. As a result, the wireless communication performance is degraded. On the other hand, when the frequency of the magnetic field H and the radio communication frequency are far from each other, the reception sensitivity of the receiver of the radio circuit board is lowered, and the radio communication performance is lowered.

The loop current I that generates the magnetic field H that affects wireless communication in this way flows not only in the form of the opening L shown in FIG. 9 but also along various forms of openings formed by the power receiving device and the metal frame. . FIG. 10 shows a state where a metal frame 30 ′ having a shape different from that of the metal frame 30 is attached to the power receiving device 50 of the comparative example. 10 includes square bars 401 (c) ′, 401 (d) ′ and square bars 401 (c) ′ extending from the power receiving device 50 of the comparative example to the rear side of the vehicle 40 and parallel to each other. , 401 (d) ′ and a square bar 401 (a) ′ connected to the lower part of the rear end portion of each vehicle 40. The metal frame 30 ′ is electrically connected to the magnetic field shielding member 104 of the power receiving device 50. A loop current I flows along the opening L 'formed by the metal frame 30 and the power receiving device 50, and a magnetic field H that affects wireless communication is generated.

On the other hand, as shown in FIG. 2, in the power receiving device 10 of the present embodiment, the magnetic shielding member 104 and the metal frame 30 are electrically insulated by the insulating material 105. For this reason, even if a current is induced in the magnetic shielding member 104 by the magnetic field generated by the power transmission coil 109 of the power feeding device 20, the current does not flow from the magnetic shielding member 104 to the metal frame 30. Therefore, as shown in FIG. 5, the loop current I does not flow along the opening L formed by the power receiving device 10 and the metal frame 30. Thereby, generation | occurrence | production of the magnetic field which causes the fall of wireless communication performance is suppressed. As a result, the first communication antenna 105 and the second communication antenna 110 can perform good short-range wireless communication. Then, the first communication antenna 105, the second communication antenna 110, the first radio circuit board 107, and the second radio circuit board 112 are passed through the magnetic field shielding board 104 by a magnetic field generated by the power transmission coil 109. It is possible to design without considering the effect of flowing. As a result, it is possible to realize a reduction in design time and development cost for wireless communication.

As described above and as shown in FIG. 2, the insulating member 105 is fixed to the magnetic shielding member 104 by connecting members 115 (a) to 115 (d) such as bolts. Further, as shown in FIG. 2, the insulating member 105 of the power receiving device 10 and the vehicle 40 pass through the through holes 402 (a) to 402 (d) of the metal frame 30, and the connecting member 114 (a ) To 114 (b). It is necessary to avoid electrical connection between the magnetic field shielding member 104 and the metal frame 30 via the connection members 114 (a) to 114 (d) and 115 (a) to 115 (d).

For example, when these connecting members 114 (a) to 114 (d) and 115 (a) to 115 (d) are made of a conductive material such as metal, the connecting members 114 (a) to 114 (d) It is necessary to avoid contact with the magnetic shielding member 104 and to avoid contact between the connection members 115 (a) to 115 (d) and the metal frame 30.

Alternatively, these connecting members 114 (a) to 114 (d) and 115 (a) to 115 (d) may be made of an insulating material such as an insulating resin. Furthermore, a through hole may be formed in each of the metal frame 30 and the insulating member 105, and the vehicle 40 and the magnetic field shielding member 104 may be connected by a connecting member that passes through these through holes and has electrical insulation.

Furthermore, the present invention is not limited to connecting the magnetic field shielding member and the insulating member by the connecting member. For example, as shown in FIG. 11, at least a part of the magnetic field shielding member 104, specifically, the edge of the magnetic field shielding member 104 and the surface on the metal frame 30 side may be covered with an insulating member 1001 having electrical insulation. Good. Thereby, the magnetic field shielding member 104 and the insulating member 1001 are integrated, and the magnetic field shielding member 104 contacts the metal frame via the insulating member 1001. That is, the magnetic field shielding member 104 and the metal frame 30 are electrically insulated. As a result, a connecting member for connecting the magnetic field shielding member and the insulating member is not necessary.

As shown in FIG. 3, the connection between the magnetic shielding member 104 and the insulating member 105 is made by four connection members 115 (a) to 115 (d), and the connection between the power receiving apparatus 10 and the vehicle 40 is four. Although the connection members 114 (a) to 114 (d) are used, the present invention is not limited to this. If the power receiving apparatus 10 and the metal frame 30 are connected while being electrically insulated by the insulating member 105, and the metal frame 30 is connected to the vehicle 40, the present invention determines the number of connection members and the connection method. Not limited.

Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

The disclosures in the specification, drawings, and claims of Japanese Patent Application No. 2011-077628 filed on Mar. 31, 2011 are incorporated herein by reference in their entirety. .

The contactless power receiving device of the contactless charging system according to the present invention is suitable for charging an electric propulsion vehicle that needs to suppress a decrease in wireless communication performance.

S Contactless Charging System 10 Power Receiving Device 102 Power Receiving Coil 103 Ferrite 104 Magnetic Field Shielding Member 105 Insulating Member 106 First Communication Antenna 107 First Radio Circuit Board 108 First Antenna Feed Line 20 Power Feed Device 40 Electric Propulsion Vehicle 30 Metal flame

Claims

A non-contact power receiving device that is attached to a lower part of a vehicle and receives power supply from a non-contact power feeding device in a non-contact manner,
A power receiving coil for receiving power from the non-contact power feeding device in a non-contact manner;
A wireless circuit board and a communication antenna for performing short-range wireless communication with the non-contact power feeding device;
A magnetic field shielding member made of a conductor disposed on the vehicle side of the power receiving coil;
A metal frame attached to the upper part of the non-contact power receiving device and attached to the lower part of the vehicle;
A non-contact power receiving apparatus including an insulating member interposed between the magnetic field shielding member and the metal frame and electrically insulating the magnetic field shielding member and the metal frame.
By covering at least part of the magnetic field shielding member with the insulating member, the magnetic field shielding member and the insulating member are integrated,
The non-contact power receiving apparatus according to claim 1, wherein the magnetic field shielding member is in contact with the metal frame via the insulating member.