JP6035155B2 - Coil device for contactless power transformer - Google Patents

Description

  The present invention relates to a coil device of a non-contact power supply transformer that supplies power to a moving body such as an electric vehicle in a non-contact manner, and improves heat dissipation characteristics and eliminates a temperature rise during power supply.

Conventionally, as a system for charging a battery of an electric vehicle or a plug-in hybrid vehicle, as shown in FIG. 12, a secondary coil (receiving coil) 102 of a non-contact power supply transformer mounted on the floor of the vehicle, A system has been developed in which a primary coil (power transmission coil) 202 installed on the side is opposed to feed power from the ground side to the vehicle side in a contactless manner.
In Patent Document 1 below, as shown in FIG. 13, in order to increase the allowable amount of positional deviation and gap fluctuation between the primary side coil and the secondary side coil of this charging system and to reduce the size of the coil. Further, it is described that a “double-sided coil” in which a coil 11 is wound around a plate-like ferrite core 10 is used. In this double-sided coil, the main magnetic flux passing through the ferrite core 10 enters and exits through the magnetic pole portions at both ends of the core.

Patent Document 2 described below describes using a coil having an H-shaped ferrite core as shown in FIG. 14 in order to further reduce the size and weight of a double-sided coil. In this coil, the winding 11 is wound around a portion corresponding to the horizontal bar of the H-shaped core, and the parallel portions 12 on both sides of the H-shaped core serve as magnetic pole portions.
As shown in FIG. 15, the primary side coil device and the secondary side coil device used in the actual charging system have a hollow coil bobbin 14 made of an insulator having a guide groove formed on the outer periphery thereof. The winding is wound along the guide groove, and both ends of the core member inserted into the hollow portion of the hollow coil bobbin 14 are configured to contact the ferrite member forming the magnetic pole portion (Patent Document 3 below). .

JP 2010-172084 A JP 2011-50127 A JP 2012-151111 A

  The double-sided coil can be reduced in size, but the heat capacity is reduced accordingly, so that the temperature is likely to rise due to iron loss in the core portion and copper loss in the winding. In order to obtain a double-sided coil that can supply high power, heat dissipation measures are indispensable.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a coil device for a non-contact power supply transformer that has excellent heat dissipation characteristics and can suppress a temperature rise during power supply.

The present invention is a coil device that constitutes a primary side coil or a secondary side coil of a non-contact power supply transformer, and has an insertion hole through which the core of the coil is inserted at the center, and a winding is wound around the outer periphery. The coil bobbin includes a square-shaped coil bobbin, and the coil bobbin includes a plurality of divided members made of aluminum or copper. The square-shaped coil bobbin is opposed to the counterpart coil. Part of the aluminum base plate arranged on the opposite side of the side, the outer peripheral surface excluding the portion that contacts the aluminum base plate of the rectangular coil bobbin, and the contact surfaces of the divided members that contact each other are insulating paint The core and the coil bobbin covered with the insertion hole are in contact with each other, and the aluminum base plate and the coil bobbin are in contact with each other without any insulating paint. And features.
In this coil device, the heat generated by the iron loss of the core portion and the copper loss of the winding is efficiently discharged to the outside through the coil bobbin and the aluminum base plate made of metal having high thermal conductivity. Moreover, since the coil bobbin is divided into a plurality of divided members and the divided members are insulated from each other, even if the coil bobbin blocks the leakage magnetic flux from the core, an increase in loss due to eddy current is suppressed.

In the coil device of the present invention, the guide groove of the winding is formed on the outer periphery of the rectangular coil bobbin, and the part where the guide groove of the coil bobbin is not formed and the part between the adjacent guide grooves are made of an aluminum base. It is comprised so that a board may be contacted.
Therefore, the heat transmitted to the coil bobbin is efficiently discharged to the outside through the aluminum base plate.

In the coil device of the present invention, the dividing member is a member obtained by dividing a rectangular coil bobbin in a direction perpendicular to the longitudinal direction of the insertion hole and in a direction parallel to the longitudinal direction.
In this way, by dividing the coil bobbin into a large number of divided members, loss due to eddy current can be suppressed.

In the coil device according to the present invention, the casing in which the rectangular coil bobbin is accommodated covers the surface facing the counterpart coil, and the resin cover having the opposite surface opened, and the resin cover opening. A rectangular coil bobbin configured with an aluminum base plate to be closed and housed in the housing contacts the aluminum base plate of the housing.
Therefore, the heat generated by the iron loss of the core part and the copper loss of the winding is efficiently discharged to the outside from the aluminum base plate on the back surface of the casing.

  The coil device of the non-contact power supply transformer of the present invention has excellent heat dissipation characteristics and can effectively suppress the temperature rise during power supply.

The figure which shows the coil bobbin of the primary side coil which concerns on embodiment of this invention (figure seen from the front side) The figure which shows the division | segmentation member of the coil bobbin of FIG. The figure which looked at the coil bobbin of Drawing 1 from the back side The figure which shows the coil bobbin of the secondary side coil which concerns on embodiment of this invention (figure seen from the front side) The figure which looked at the coil bobbin of Drawing 4 from the back side The figure which shows the division | segmentation member of the coil bobbin of FIG. The figure which shows the state which installed the coil bobbin of FIG. 1 on Al base board The figure which shows the state which installed the coil bobbin of FIG. 4 on the Al base board 1 is a top view of a housing that houses the coil bobbin of FIG. Side sectional view of the housing of FIG. The perspective view of the housing | casing of FIG. Diagram showing a contactless power supply system for automobiles Diagram showing double-sided coil The figure which shows the double-sided winding coil which has an H-shaped core Diagram showing a conventional coil bobbin

FIG. 11 shows a housing in which the coil device of the present invention is accommodated. The housing that houses the primary coil and the housing that houses the secondary coil have substantially the same shape.
FIG. 11A is a view of the housing as viewed from the side facing the counterpart coil (hereinafter referred to as the front side), and FIG. 11B is from the opposite side (hereinafter referred to as the back side). It is the figure which looked at the housing | casing. The front side of the housing is covered with a resin cover 21, and the opening on the back side of the resin cover 21 is closed with an aluminum (Al) base plate 22. The Al base plate 22 is provided with a lead-out port 23 for leading out the electric wire at the coil end.
The resin cover 21 of the housing is formed of resin so as not to prevent the passage of the main magnetic flux flowing between the counterpart coil. In addition, the Al base plate 22 is made of a metal having high thermal conductivity in order to prevent leakage magnetic flux from passing through the housed coil and to improve heat dissipation characteristics.

FIG. 1 shows a rectangular coil bobbin 30 of a primary side coil as viewed from the front side. The rectangular coil bobbin 30 is made of Al, and is configured by combining eight Al dividing members 31 shown in FIG. The divided member 31 corresponds to a member obtained by dividing the rectangular coil bobbin 30 into two in the longitudinal direction, divided into two in the lateral direction, and further divided into two in the thickness direction.
This rectangular coil bobbin 30 has two insertion holes 32 through which the core of the coil is inserted, and a ferrite core is inserted into each insertion hole 32. Both ends of the inserted ferrite core protrude from the insertion hole 32 and come into contact with the ferrite member constituting the magnetic pole part.
A winding guide groove 33 is formed on the outer periphery of the rectangular coil bobbin 30.

FIG. 3 shows a rectangular coil bobbin 30 of the primary coil viewed from the back side.
The outer periphery of the rectangular coil bobbin 30 and the joint surface between the divided members 31 are covered with an insulating paint.
However, as shown in FIG. 3, the inside of the insertion hole 32 and the back side portion that contacts the Al base plate 22 of the housing, that is, the contact portion 34 where the guide groove 33 is not formed, and the adjacent guide groove 33. Insulating paint is not provided on the standing part 35 between the two.

The reason why the divided members 31 are insulated from each other is to prevent eddy current from being generated in the coil bobbin even if the coil bobbin made of Al blocks the magnetic flux leaking from the core, thereby increasing the loss due to eddy current. Is suppressed.
Moreover, the reason why the inside of the insertion hole 32 is not covered with the insulating paint is to efficiently transfer heat due to iron loss generated in the ferrite core to the Al coil bobbin, and to the Al base plate 22 of the casing. The reason why the contact surface of the contacting coil bobbin is not covered with the insulating paint is to efficiently escape to the outside through the Al base plate 22 after the heat of the ferrite core and the heat of the copper loss of the winding are transferred to the coil bobbin. is there.

4 shows the square coil bobbin 40 of the secondary coil viewed from the front side, and FIG. 5 shows the square coil bobbin 40 of the secondary coil viewed from the back side. Similar to the rectangular coil bobbin 30 of the primary side coil, the rectangular coil bobbin 40 of the secondary side coil is configured by combining eight Al divided members 41 shown in FIG. The divided member 41 corresponds to a member obtained by dividing the rectangular coil bobbin 40 into two in the longitudinal direction, divided into two in the lateral direction, and further divided into two in the thickness direction.
In addition, the rectangular coil bobbin 40 is coated with an insulating paint on the outer periphery except for the back side portion that contacts the Al base plate 22 of the casing, similarly to the rectangular coil bobbin 30 of the primary side coil. The joint surface is covered with an insulating paint. In this square coil bobbin 40, the contact portion 42 on the back side shown in FIG. 5 contacts the Al base plate 22.

FIG. 7 shows a state in which a ferrite member 51 forming a magnetic pole portion and a square coil bobbin 30 of a primary coil are installed on an Al base plate 22 of the casing, and FIG. 8 shows an Al base of the casing. A state is shown in which a ferrite member 52 forming a magnetic pole portion and a square coil bobbin 40 of a secondary coil are installed on the plate 22.
FIG. 9 is a top sectional view of a casing in which a rectangular coil bobbin 30 of a primary side coil and a ferrite member 51 forming a magnetic pole portion are housed, and FIG. 10 is a side sectional view thereof.

As shown in FIG. 10, the contact portion 34 and the standing portion 35 of the rectangular coil bobbin 30 are in contact with the Al base plate 22. Further, both end portions of the ferrite core 53 inserted into the insertion port of the rectangular coil bobbin 30 are in contact with the ferrite member 51 that protrudes from the insertion port and forms a magnetic pole portion.
The inside of the housing in which the square coil bobbin 40 of the secondary side coil is accommodated is also substantially the same as FIGS.

Thus, in this coil device, since the square coil bobbin is made of Al having high thermal conductivity, the heat generated in the core and the winding during power feeding can be easily released through the coil bobbin.
Further, since the square coil bobbin is in contact with the Al base plate, the heat transmitted to the square coil bobbin can be efficiently released to the outside through the Al base plate.
In addition, since the square coil bobbin is composed of a plurality of divided members and the divided members are insulated, the eddy current generated when the conductive metal blocks the leakage magnetic flux can be suppressed. An increase can be avoided.

Here, although Al is used as the material of the rectangular coil bobbin, copper having a high thermal conductivity may be used.
Moreover, although the example which comprises a square coil bobbin by eight division members was shown here, the division | segmentation number may be other than eight.
In addition, here, a double-sided coil including an H-shaped core is shown, but the present invention can also be applied to a double-sided coil having a rectangular core shape as shown in FIG.
Moreover, although the case where the Al base plate is the back plate of the housing is shown here, the Al base plate may not be a constituent member of the housing. In a double-sided coil, a leakage magnetic flux that bypasses the opposite side (back side) of the side facing the counterpart coil is generated, and in order to suppress the influence of this leakage magnetic flux, an electromagnetic shielding metal plate made of a non-magnetic good conductor such as an aluminum plate is used. Located on the back side of the coil. Therefore, this electromagnetic shielding metal plate may be used as the Al base plate.
Although the coil device using a ferrite core has been described here, another magnetic body having a small loss at a frequency used for non-contact power feeding, for example, an amorphous magnetic body may be used for all or a part of the core.

  Since the coil device of the present invention has high heat dissipation characteristics, it is possible to perform high-power non-contact power feeding even if it is small, and non-contact to various moving bodies such as electric vehicles and plug-in hybrid vehicles. It can be widely used for power feeding.

DESCRIPTION OF SYMBOLS 10 Ferrite core 11 Winding 12 Magnetic pole part 14 Coil bobbin 21 Resin cover 22 Al base board 23 Electric wire outlet 30 Square coil bobbin of primary side coil 31 Dividing member 32 Core insertion hole 33 Guide groove 34 Contact part 35 Standing part between guide grooves 40 Square coil bobbin of secondary coil 41 Split member 51 Ferrite member constituting magnetic pole part 52 Ferrite member constituting magnetic pole part 102 Secondary coil (power receiving coil)
202 Primary coil (power transmission coil)

Claims (4)

A coil device constituting a primary side coil or a secondary side coil of a non-contact power supply transformer,
It has an insertion hole through which the core of the coil is inserted in the center, and includes a square-shaped coil bobbin around which the winding is wound,
The coil bobbin is composed of a plurality of divided members made of aluminum or copper, and the square shape is maintained by a combination of the divided members.
A part of the square-shaped coil bobbin is in contact with an aluminum base plate disposed on the opposite side of the side facing the counterpart coil,
The outer peripheral surface of the rectangular coil bobbin excluding the portion that contacts the aluminum base plate, and the contact surfaces of the divided members that contact each other are covered with an insulating paint, and the core inserted through the insertion hole and the core A coil device comprising: a coil bobbin; and a contact between the aluminum base plate and the coil bobbin without the insulating paint.   2. The coil device according to claim 1, wherein a guide groove is formed at a winding position of the winding on an outer periphery of the rectangular coil bobbin, and the guide groove of the coil bobbin is not formed. The coil device, wherein a portion and a portion between the adjacent guide grooves are in contact with the aluminum base plate.   3. The coil device according to claim 1, wherein the dividing member divides the rectangular coil bobbin into a direction orthogonal to a longitudinal direction of the insertion hole and a direction parallel to the longitudinal direction. A coil device comprising the obtained member.   The coil device according to any one of claims 1 to 3, further comprising a casing in which the rectangular coil bobbin is accommodated, and the casing covers a surface on a side facing the counterpart coil, A resin cover having an opening on the opposite side; and the aluminum base plate closing the opening on the resin cover, wherein the rectangular coil bobbin housed in the housing is in contact with the aluminum base plate. Coil device characterized by this.