JP2018133519A - Power transmission unit and magnetic member for coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission unit and a magnetic member for a coil capable of suppressing temperature rise of a power transmission unit.SOLUTION: A power transmission unit 1 includes: a power transmission coil 20 which is provided in a spiral shape around a coil axis X and transmits electric power in a noncontact manner; and a ferrite 40 provided in the power transmission coil 20 and containing a magnetic material. The ferrite 40 includes: a body 41 provided along an intersecting direction intersecting the coil axis X; and a wall portion 42 provided in the body 41, annularly formed around the coil axis X, and located inside the power transmission coil 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power transmission unit and a magnetic member for a coil.

  Conventionally, there is a power transmission unit that transmits power in a non-contact manner. The power transmission unit includes, for example, a power transmission coil formed in a spiral shape and ferrite including a magnetic material provided in the power transmission coil (for example, Patent Document 1). The power transmission unit transmits power in a non-contact manner by electromagnetic induction or magnetic field resonance using a power transmission coil.

JP 2014-49479 A

  By the way, in the conventional power transmission unit, an eddy current is generated by the magnetic force generated from the power transmission coil, and the temperature of the power transmission unit tends to rise due to the generation of the eddy current. In this respect, there is room for further improvement. is there.

  Then, this invention is made | formed in view of the above, Comprising: It aims at providing the electric power transmission unit which can suppress the temperature rise of an electric power transmission unit, and the magnetic member for coils.

  In order to solve the above-described problems and achieve the object, a power transmission unit according to the present invention is provided in a spiral shape around a coil axis and transmits power in a non-contact manner, and is provided in the power transmission coil. A magnetic member including a magnetic material, and the magnetic member is formed in a body portion formed along a direction intersecting the coil axis, and formed in an annular shape around the coil axis provided in the body portion. And a wall portion located inside the power transmission coil.

  The power transmission unit includes a communication module that performs wireless communication, the main body has an opening on the coil axis, the communication module is provided in the opening, and the wall is It is preferable to be provided so as to surround the communication module.

  Further, in the power transmission unit, the wall portion protrudes from the main body portion along a coil axis direction that is a direction along the coil axis, and when viewed from a direction orthogonal to the coil axis, It is preferable that the end on the opposite side to the main body is located on the opposite side of the main body from the power transmission coil and the communication module.

  The magnetic member for a coil according to the present invention includes a magnetic member including a magnetic material provided in a power transmission coil that is spirally formed around a coil axis and transmits electric power in a non-contact manner, and the magnetic member includes the coil It is preferable to have a main body portion formed along a direction intersecting the axis, and a wall portion provided in the main body portion and formed in an annular shape around the coil axis line and positioned inside the power transmission coil.

  The power transmission unit and the coil magnetic member according to the present invention are generated from the power transmission coil because the magnetic member includes a wall portion that is provided in the main body and is annularly formed around the coil axis and is positioned inside the power transmission coil. The magnetic force to be distributed can be suppressed from being distributed inside the power transmission coil, and the eddy current can be prevented from flowing inside the power transmission coil. As a result, the power transmission unit can suppress the temperature rise of the power transmission unit.

FIG. 1 is a perspective view illustrating a configuration example of a power transmission unit according to the embodiment. FIG. 2 is a cross-sectional view illustrating a configuration example of the power transmission unit according to the embodiment. FIG. 3 is a cross-sectional view illustrating a configuration example of the power transmission system according to the embodiment. FIG. 4 is a diagram illustrating an example of the rising temperature according to the embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

Embodiment
The power transmission unit 1 according to the embodiment will be described. The power transmission unit 1 is a unit that transmits power without contact and wirelessly communicates signals. The power transmission unit 1 functions as a power transmission side that transmits power or a power reception side that receives power. The power transmission unit 1 is used, for example, when charging a storage battery provided in a vehicle (not shown). In this case, the power transmission unit 1 on the power receiving side is installed, for example, on the bottom surface of the vehicle and connected to the storage battery of the vehicle. The power transmission unit 1 on the power transmission side is installed on the ground of a charging station (not shown) and connected to a power source, for example. The power transmission unit 1 on the power transmission side transmits power supplied from the power source to the power transmission unit 1 on the power reception side by electromagnetic induction, magnetic resonance, or the like in a state of facing the power transmission unit 1 on the power reception side. The power transmission unit 1 on the power receiving side receives the power transmitted from the power transmission unit 1 on the power transmission side, and outputs the received power to the storage battery of the vehicle. In the following description, the main configuration of the power transmission unit 1 is the same on the power transmission side and the power reception side. Therefore, the power transmission unit 1 will be described without distinguishing between the power transmission side and the power reception side unless otherwise specified.

  As shown in FIGS. 1 and 2, the power transmission unit 1 includes a substrate 10, a power transmission coil 20, a communication coupler 30 as a communication module, and a ferrite 40 as a magnetic member (magnetic member for coil). ing. In order to facilitate understanding of the description, the power transmission unit 1 is illustrated with the housing removed.

  Here, the coil axis direction is a direction along the coil axis X. In the coil axial direction, the upper side in the coil axial direction is the substrate 10 side, and the lower side in the coil axial direction is the power transmission coil 20 side. The intersecting direction is a direction intersecting the coil axis direction. The orthogonal direction is a direction orthogonal to the coil axis direction.

  The board 10 constitutes an electronic circuit on which various electronic components are mounted and electrically connect the electronic parts, and is a so-called printed circuit board. The substrate 10 has a wiring pattern (print pattern) formed of a conductive member such as copper foil on an insulating layer made of an insulating material such as epoxy resin, glass epoxy resin, paper epoxy resin, or ceramic. The substrate 10 is electrically connected to the power transmission coil 20.

  The power transmission coil 20 is a coil that transmits power without contact. In the power transmission coil 20, a conductor wire through which a current flows is provided in a spiral shape around the coil axis X. The power transmission coil 20 includes a coil winding portion 21 in which a conductor wire is formed in a spiral shape, a winding start end portion 22 that is an end portion on the winding start side of the conductor wire, and an end portion on the winding end side of the conductor wire. A winding end portion 23 is provided. The power transmission coil 20 is electrically connected to the circuit of the substrate 10. For example, the power transmission coil 20 has a winding start end portion 22 and a winding end end portion 23 connected to an electronic component mounted on the substrate 10 via wiring.

  The communication coupler 30 is an antenna that performs wireless communication with the communication coupler 30 on the other side. The communication coupler 30 uses, for example, TransferJet (registered trademark), which is a proximity wireless transfer technology. The communication coupler 30 is provided in an opening 43 of the ferrite 40 described later. The communication coupler 30 includes a communication board 31, a coupling electrode 32, and a coaxial connector 33.

  The communication board 31 is formed in a rectangular shape, and a communication circuit is formed. The coupling electrode 32 is a conductive member that is connected to the circuit of the communication board 31 and accumulates charges used for communication. The coupling electrode 32 includes a circular electrode plate 32a and an electrode rod 32b extending along the coil axis direction from the approximate center of the electrode plate 32a. The coupling electrode 32 is connected to the circuit of the communication substrate 31 at the end opposite to the electrode plate 32a of the electrode bar 32b. The coaxial connector 33 is a connector that is provided on the opposite side of the communication board 31 from the coupling electrode 32 and connects a circuit of the communication board 31 and a cable (not shown).

  The ferrite 40 is a magnetic member that controls the loss of magnetic force through the magnetic force generated by the power transmission coil 20. The ferrite 40 is a member containing a magnetic material, and is, for example, a composite oxide of iron oxide and metal. The ferrite 40 is provided in the power transmission coil 20 and includes a main body 41 and a wall 42. The main body 41 is formed in a plate shape and is provided along the intersecting direction. The main body portion 41 faces the power transmission coil 20 and has a portion that overlaps the entire coil winding portion 21 when viewed from the coil axis direction. The main body 41 is composed of, for example, four rectangular and plate-like ferrite plates 41a to 41d. The main body 41 is arranged along the crossing direction (for example, the orthogonal direction) around the coil axis X so that each of the ferrite plates 41a to 41d has the opening 43 on the coil axis X. For example, the main body 41 includes a first ferrite plate 41a and a second ferrite plate 41b arranged in parallel, a third ferrite plate 41c and a fourth ferrite plate 41d arranged in parallel, and the first and second ferrite plates. 41a, 41b and third and fourth ferrite plates 41c, 41d are arranged orthogonally to form an opening 43 surrounded by the first to fourth ferrite plates 41a-41d. The communication coupler 30 is disposed in the opening 43.

  The wall portion 42 protrudes from the main body portion 41 toward the power transmission coil 20 along the coil axis direction, and is provided inside the power transmission coil 20. The wall portion 42 is formed in an annular shape around the coil axis X so as to surround the communication coupler 30. For example, the wall part 42 is comprised from the bar-shaped four ferrite rods 42a which are rectangular parallelepiped shapes. In the wall portion 42, each ferrite rod 42 a is connected in an annular shape around the coil axis X. The wall portion 42 is formed in a rectangular shape according to the shape of the rectangular communication substrate 31 of the communication coupler 30 when viewed from the coil axis direction. When the wall 42 is viewed from the crossing direction (orthogonal direction), the end 42b of the wall 42 opposite to the main body 41 is opposite to the main body 41 from the power transmission coil 20 and the communication coupler 30. Is located. For example, the end portion 42 b of the wall portion 42 protrudes downward from the electrode plate 32 a of the communication coupler 30 in the coil axis direction.

  As shown in FIG. 3, the power transmission unit 1 </ b> A is disposed to face the counterpart power transmission unit 1 </ b> B along the coil axis direction. That is, the communication coupler 30 of the power transmission unit 1A and the communication coupler 30 of the power transmission unit 1B are disposed so as to be communicable with each other, and the power transmission coil 20 of the power transmission unit 1A and the power of the power transmission unit 1B are arranged. The transmission coil 20 is disposed so as to face the power transmission. The power transmission unit 1A and the power transmission unit 1B are arranged opposite to each other with no obstacle between the power transmission unit 1A and the power transmission unit 1B, or between the power transmission unit 1A and the power transmission unit 1B. There may be a case where the non-conductive member is interposed between the two with the obstacle interposed therebetween. The power transmission unit 1A and the power transmission unit 1B have substantially the same configuration, and function as a transmission side that transmits an electrical signal or a reception side that receives an electrical signal, depending on the usage. Further, the power transmission unit 1A and the power transmission unit 1B function as a power transmission side that transmits power or a power reception side that receives power, depending on the usage.

  Next, an operation example of the power transmission unit 1 (1A, 1B) will be described. An example in which the power transmission unit 1A transmits an electric signal and receives electric power, and the power transmission unit 1B receives an electric signal and transmits electric power will be described.

  The communication coupler 30 of the power transmission unit 1 </ b> A accumulates electric charge in the coupling electrode 32 when an electric signal is input from a cable connected to the coaxial connector 33. In a state where the power transmission unit 1A and the power transmission unit 1B face each other in the coil axis direction, the communication coupler 30 of the power transmission unit 1A uses the charge accumulated in the coupling electrode 32 as an electrical signal as the communication coupler 30 of the power transmission unit 1B. Send to. The communication coupler 30 of the power transmission unit 1 </ b> B receives the electrical signal transmitted from the communication coupler 30 of the power transmission unit 1 </ b> A and outputs the electrical signal via a cable connected to the coaxial connector 33.

  In addition, an AC power supply (not shown) supplies power to the power transmission coil 20 of the power transmission unit 1B via a circuit for power transmission. When a current flows through the power transmission coil 20, a magnetic field is generated, and a current flows through the power transmission coil 20 of the power transmission unit 1A by the induced electromotive force generated by the magnetic field, and the power is transmitted.

  Next, rising temperatures of the power transmission coil 20 and the communication coupler 30 will be described by comparing the embodiment and the comparative example. The power transmission unit (not shown) according to the comparative example is a power transmission unit in which the wall portion 42 of the ferrite 40 is not provided.

  As illustrated in FIG. 4, the rising temperature T1 of the transmission-side communication coupler 30 according to the embodiment is lower than the rising temperature T2 of the transmission-side communication coupler according to the comparative example, and the reception-side communication coupler according to the embodiment. The temperature rise T3 of 30 was lower than the temperature rise T4 of the communication coupler on the receiving side according to the comparative example. In addition, the temperature rise T5 of the power transmission coil 20 on the power transmission side according to the embodiment is lower than the temperature rise T6 of the power transmission coil on the power transmission side according to the comparative example, and the power transmission coil 20 on the power reception side according to the embodiment. The rising temperature T7 was lower than the rising temperature T8 of the power transmission coil on the power receiving side according to the comparative example. Thus, in the power transmission unit 1 according to the embodiment, the temperature rise of the communication coupler 30 on the transmission side and the reception side is lower than that of the power transmission unit according to the comparative example, and the power transmission coils on the power transmission side and the power reception side are reduced. The rising temperature of 20 decreased.

  As described above, according to the power transmission unit 1 according to the embodiment, the power transmission coil 20 provided in a spiral around the coil axis X and transmitting power in a non-contact manner, and the magnetic material provided in the power transmission coil 20 are used. Including ferrite 40. The ferrite 40 includes a main body 41 provided along a crossing direction intersecting the coil axis X, and a wall provided in the main body 41 and formed in an annular shape around the coil axis X and positioned inside the power transmission coil 20. 42. Thereby, the power transmission unit 1 can suppress the magnetic force generated from the power transmission coil 20 from being distributed inside the power transmission coil 20 by the wall portion 42 of the ferrite 40. Therefore, the power transmission unit 1 can suppress an eddy current that generates a magnetic field that cancels the fluctuation of the magnetic field caused by the power transmission coil 20 from flowing inside the power transmission coil 20, and thus suppresses a temperature rise of the power transmission coil 20. Can do. As a result, the power transmission unit 1 can suppress the temperature rise of the power transmission unit 1.

  Further, according to the power transmission unit 1, the communication coupler 30 that performs wireless communication is provided, the main body 41 has the opening 43 on the coil axis X, and the communication coupler 30 is provided in the opening 43, and the wall The unit 42 is provided so as to surround the communication coupler 30. Accordingly, the power transmission unit 1 can suppress the magnetic force generated from the power transmission coil 20 from affecting the communication coupler 30 by the wall portion 42 of the ferrite 40. Therefore, the power transmission unit 1 can suppress the eddy current from flowing through the communication coupler 30, and thus can suppress the temperature rise of the communication coupler 30. As a result, the power transmission unit 1 can suppress the temperature rise of the power transmission unit 1.

  Further, according to the power transmission unit 1, when viewed from the direction orthogonal to the coil axis X, the end 42 b of the wall 42 opposite to the body 41 is projected from the main body 41 along the coil axis direction. The power transmission coil 20 and the communication coupler 30 are located on the side opposite to the main body 41. Thereby, the power transmission unit 1 can effectively suppress the magnetic force generated from the power transmission coil 20 from being distributed inside the power transmission coil 20 and can effectively suppress the communication coupler 30 from being affected. .

[Modification]
Next, a modification of the embodiment will be described. Although the board | substrate 10 demonstrated as what is a printed circuit board, it is not limited to this. For example, the substrate 10 may be an insert bus bar substrate or the like in which a conductive metal bus bar is built in an insulating resin material and various circuits are configured by the bus bar.

  Moreover, although the ferrite 40 demonstrated the example comprised from several ferrite plates 41a-41d, it is not limited to this. The ferrite 40 may be composed of a single ferrite plate, and a hole may be formed in the ferrite plate to provide an opening 43, and a wall 42 may be provided around the opening 43.

  Moreover, although the wall part 42 demonstrated the example formed in a rectangular shape when it sees from a coil axial direction, it is not limited to this. For example, the wall portion 42 may have another polygonal shape, or may be circular or elliptical.

  Moreover, although the wall part 42 demonstrated the example comprised from the some ferrite rod 42a, it is not limited to this. For example, the wall portion 42 may be integrally formed with the main body portion 41.

  In addition, the end 42b of the wall 42 is located on the opposite side of the main body 41 from the power transmission coil 20 and the communication coupler 30, and the end 42b is further provided on the opposite side of the main body 41. Even if it made it protrude, the raise temperature of the communication coupler 30 and the electric power transmission coil 20 hardly changed. As a result, the power transmission unit 1 has the largest protrusion amount in a state in which the end portion 42b of the wall portion 42 is located (projected) on the opposite side of the main body portion 41 from the power transmission coil 20 and the communication coupler 30. The size can be reduced by reducing the number.

[Reference example]
As a reference example, when the wall portion 42 of the ferrite 40 is provided only in the power transmission unit 1 on either the power transmission side or the power reception side, the temperature of the power transmission unit 1 on the side where the wall portion 42 of the ferrite 40 is not provided is It rose significantly. For this reason, it is difficult to provide the wall portion 42 only on the ferrite 40 of the power transmission unit 1 on either the transmission side or the reception side, and the wall portion on the ferrite 40 of the power transmission unit 1 on both the transmission side and the reception side is difficult. 42 must be provided.

1, 1A Power transmission unit 10 Substrate 20 Power transmission coil 30 Communication coupler 40 Ferrite 41 Main body 42 Wall 42b End 43 Opening X Coil axis

Claims (4)

A power transmission coil provided in a spiral around the coil axis and transmitting power in a contactless manner;
A magnetic member provided on the power transmission coil and including a magnetic material,
The magnetic member is
A main body formed along a direction intersecting the coil axis;
A wall portion provided in the main body portion and formed in an annular shape around the coil axis and located inside the power transmission coil;
A power transmission unit comprising: A communication module that performs wireless communication is provided.
The main body has an opening on the coil axis,
The communication module is provided in the opening,
The power transmission unit according to claim 1, wherein the wall portion is provided so as to surround the communication module. The wall is
When projecting from the main body along the coil axis direction, which is a direction along the coil axis, and viewed from a direction orthogonal to the coil axis, the end of the wall opposite to the main body is The power transmission unit according to claim 2, wherein the power transmission unit is located on a side opposite to the main body portion from the power transmission coil and the communication module. A magnetic member including a magnetic material provided in a power transmission coil that is formed in a spiral shape around the coil axis and transmits power in a non-contact manner,
The magnetic member is
A main body formed along a direction intersecting the coil axis;
A wall portion provided in the main body portion and formed in an annular shape around the coil axis and located inside the power transmission coil;
The magnetic member for coils characterized by having.

Images