Coil unit and wireless transmission device

Abstract

A coil unit includes a non-magnetic conductive plate which is disposed in an arrangement direction of first and second coils have reverse winding direction to each other, 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 arrangement direction of the first and second coils, and a second portion which is positioned in an outer side than an outline of the other side of the conductive plate in the arrangement direction of the first and second coils. When viewing from the arrangement direction of the first and second coils, the first and second portions are positioned on a side of the conductive plate where is opposite to a side which faces the first and second coils.

Description

technical field [0001] The invention relates to a coil unit and a wireless power transmission device. Background technique [0002] In recent years, in order to supply power without mechanical contact such as cables, the wireless power transmission technology that utilizes the electromagnetic induction between the primary (power transmission) coil and the secondary (power reception) coil facing each other has attracted people's attention. attention, it is predicted that it will be widely used as a power feeding device for charging secondary batteries mounted on electric vehicles (EV: Electric Vehicle) and plug-in hybrid electric vehicles (PHEV: Plug-in Hybrid Electric Vehicle) use. [0003] However, when wireless power transmission technology is applied as a power feeding device that feeds electric power to electric vehicles, etc., it is conceivable that the positional relationship between the power transmission coil installed on the ground, etc., and the power reception co...

AI Technical Summary

Problems solved by technology

However, when a coil is helically wound on a magnetic core, a magnetic flux is easily generated to go around a place away from the coil, so there is a problem that an unnecessary leakage magnetic field is likely to be formed at a place away from the coil.

Especially when the wireless power transmission technology is applied to the charging device in power electronic equipment such as electric vehicles, due to the requirement of large power transmission, a large current needs to flow through the coil, so the strength of the leakage magnetic field formed at a place far away from the coil will also increase. There is concern about causing electromagnetic wave disturbances and causing adverse effects on surrounding electronic devices, etc.

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