Coil unit, wireless power transmitting device, wireless power receiving device, and wireless power transmission system

Abstract

The present invention provides a coil unit capable of suppressing a change in the inductance factors of the power feeding coil (10) even when a positional relationship between the power feeding coil (10) and the power receiving coil (20) is deviated. A coil unit (Lr) is provided with a power receiving coil (20) wound in a plane spiral shape so as to have an opening portion (20a) at a center with asmaller winding area than the power feeding coil (10); a magnetic member (21) disposed along the surface of the power receiving coil (20) on the opposite side as seen from the power supply coil (10);the magnetic member 21 is composed of a plurality of magnetic bodies (21a to 21d) that are disposed apart from each other. The magnetic bodies (21a to 21d) are arranged such that the winding portionof the power receiving coil (20) and the opening portion (20a) overlap each other in plan view. The width s1 which is a separation distance between two adjacent magnetic bodies among the magnetic bodies (21a to 21d) is 3% or more and 30% or less of the maximum width d1 of the power receiving coil (20).

Description

technical field [0001] The invention relates to a coil unit, a wireless power supply device, a wireless power receiving device, and a wireless power transmission system. Background technique [0002] In recent years, attention has been drawn to wireless power transmission technologies for charging mobile devices such as mobile devices and electric vehicles by using electromagnetic induction between opposing primary (power supply) coils and secondary (power receiving) coils. In response to this technology, research has been conducted on a technology that can transmit power with high efficiency and low loss by connecting capacitors in series or parallel to coils to form a resonant circuit. [0003] In Patent Document 1, a non-contact power transmission device that performs power transmission using the wireless power transmission technique described above is disclosed. This non-contact power transmission device is composed of a primary coil provided on a power supply side memb...

AI Technical Summary

Problems solved by technology

That is, the above-mentioned problem is that when the first coil with a relatively large winding area and the second coil with a relatively small winding area are arranged and used to face each other, if the positional relationship of these planes deviates, the The inductance varies greatly, and the result can be summarized as a change in the resonance state of the resonance circuit composed of the first coil and the second coil, and the power transmission efficiency decreases.

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