Coil unit and wireless power transmission device

• US 10,014,105 B2
• Filed: 03/18/2015
• Issued: 07/03/2018
• Est. Priority Date: 03/25/2014
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Chiyo, Noritaka, Nishiyama, Tetsuya, Terasaki, Yasuhiro, Suzuki, Mitsunari
• Primary Examiner(s): Cox, Cassandra
• Application Number:
  US14/661,675
• Publication Number:
  US 20150279555A1
• Time in Patent Office: 1,203 Days
• Field of Search: None
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/363 made of electrically conductive material
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

A coil unit includes a non-magnetic conductive plate which is disposed along an axis of a coil, and a magnetic body. The magnetic body includes a first portion which is positioned in an outer side than an outline of one side of the conductive plate in the axis direction of the coil, and a second portion which is positioned in an outer side than an outline of the other side of the conductive plate in the axis direction of the coil. When viewing from the axis direction of the coil, the first and second portions are positioned on a side of the conductive plate where is opposite to a side which faces the coil.

Claims

1. A coil unit of a wireless power transmission device which wirelessly transmits power from a transmission side to a power receiving side, comprising:

a coil including a winding wire wound in a helical shape along an axis of the coil;

a non-magnetic conductive plate which (1) is disposed along the axis of the coil on one side of the coil and (2) has first and second ends; and

a magnetic body positioned on an opposite side of the non-magnetic conductive plate from the coil;

wherein;

the magnetic body includes;

a first portion which extends beyond the first end of the non-magnetic conductive plate along the axis of the coil;

a second portion which extends beyond the second end of the non-magnetic conductive plate along the axis of the coil; and

a third portion which extends between the first portion and the second portion; and

the first, second and third portions are comprised of materials such that imaginary component values of permeability of the first and second portions are smaller than an imaginary component value of permeability of the third portion.

2. A wireless power transmission device which wirelessly transmits power from a transmission coil to a power receiving coil unit facing each other, comprising:

the transmission coil includes a winding wire wound on a magnetic core; and

the power receiving coil unit includes the coil unit according to claim 1,

wherein, when viewing from a facing direction of the transmission coil and the power receiving coil unit, at least a part of the non-magnetic conductive plate of the coil unit extends beyond an end of the magnetic core.

3. A wireless power transmission device which wirelessly transmits power from first and second transmission coils to a power receiving coil unit facing each other, comprising:

the directions of magnetic fields generated when a current flows to the first and second transmission coils are reversed to each other, and are apposed;

a magnetic core which is disposed along an arrangement direction of the first and second transmission coils; and

the power receiving coil unit includes the coil unit according to claim 1,

wherein, when viewing from a facing direction of the first and second transmission coils and the power receiving coil unit, at least a part of the non-magnetic conductive plate of the coil unit extends beyond an end of the magnetic core.

4. A wireless power transmission device which wirelessly transmits power from a transmission coil unit to a power receiving coil facing each other, comprising:

the transmission coil unit includes the coil unit according to claim 1; and

the power receiving coil,

wherein the coil of the coil unit includes a magnetic core, and

wherein, when viewing from a facing direction of the transmission coil unit and the power receiving coil, at least a part of the non-magnetic conductive plate of the coil unit extends beyond an end of the magnetic core.