WO2019207689A1 - In-vehicle battery charging device - Google Patents

Abstract

This in-vehicle battery charging device (1) is provided with: a substrate (2) having a hole (21); a heat dissipating portion (11) facing the substrate (2); a heat dissipating member (12) facing the hole (21) and disposed on the substrate (2) side of the heat dissipating portion (11); and a filter unit (3) provided in the wiring between a step-down unit (22), which steps down a voltage output by a travel battery (98) when charging an accessory battery (99), and the travel battery (98). The filter unit (3) has an inductor (31) and is fixed to the substrate (2), wherein heat generated in the inductor (31) is dissipated to the heat dissipating portion (11) via the hole (21) and the heat dissipating member (12).

Description

In-vehicle battery charger

This invention relates to an in-vehicle battery charger.

A vehicle such as an electric vehicle or a plug-in hybrid vehicle has a traveling battery that outputs DC high-voltage power that is mainly used as a power source for driving power, and a DC low voltage that is mainly used as a power source for operating on-vehicle electrical equipment. And an auxiliary battery that outputs voltage power. In such a vehicle, the voltage output from the traveling battery is stepped down by a DC-DC converter, and the auxiliary battery is charged using the power of the traveling battery. When charging the auxiliary battery, a current flows from the traveling battery to the DC-DC converter, and this current generates magnetic noise. In order to suppress this magnetic noise, a filter is generally provided. However, the generated magnetic noise increases with the increase in the voltage and current of the power output from the battery for traveling. Further technical studies on the filter section are being conducted.

For example, Patent Literature 1 discloses an input terminal, an output terminal, a power conversion unit that converts a DC input voltage applied to the input terminal into a DC output voltage of a predetermined level and outputs the DC output voltage to the output terminal, and the input terminal and power A power conversion unit and a noise filter comprising a noise filter unit connected between the conversion unit, a shield plate having an insulator on both sides, a power conversion unit, a noise filter unit, and a metal case for housing the shield plate The DC-DC converter is disclosed in which the unit is stacked via a shield plate, and the negative output side of the power conversion unit, the shield plate, and the metal case are electrically connected.

JP 2016-36219 A

The filter unit generally uses an inductor wound around a magnetic core in order to suppress magnetic noise. However, as the current flowing through the coil increases, the Joule heat generated by the coil also increases. The magnetic material loses its characteristics as a magnetic material when the magnetic material itself exceeds a certain temperature. Therefore, if the temperature of the magnetic core increases due to the Joule heat generated by the coil, the inductance of the inductor decreases, and magnetic noise cannot be sufficiently suppressed.
The DC-DC converter disclosed in Patent Document 1 cannot sufficiently dissipate the Joule heat generated by the coil, so the temperature of the magnetic core rises and the performance of suppressing magnetic noise due to the inductor cannot be maintained. There was a problem.

An object of the present invention is to solve the above-mentioned problem, and to provide an in-vehicle battery charging device capable of suppressing the temperature rise of a magnetic core and maintaining the performance of suppressing magnetic noise caused by an inductor. It is said.

An in-vehicle battery charging device according to the present invention includes a board having a hole, a heat radiating part facing the board, a heat radiating member facing the hole and arranged on the board side of the heat radiating part, and an auxiliary battery. A filter unit provided between a voltage drop unit for stepping down a voltage output from the traveling battery and a traveling battery when charging, having an inductor, fixed to the substrate, and heat generated in the inductor Includes a filter part that radiates heat to the heat radiating part through the hole part and the heat radiating member.

According to the present invention, it is possible to suppress the temperature rise of the magnetic core and maintain the performance of suppressing magnetic noise caused by the inductor.

3 is a block diagram showing an example of a functional block configuration of the in-vehicle battery charging device according to Embodiment 1. FIG. It is an outline figure showing an example of composition which looked at a substrate in an in-vehicle battery charging device concerning Embodiment 1 from a direction which intersects perpendicularly with a substrate surface. FIG. 3 is an external view showing an example of a configuration in which the filter unit in the in-vehicle battery charging device according to Embodiment 1 is fixed to the substrate shown in FIG. 2 as viewed from a direction perpendicular to the substrate surface. FIG. 4 is an external view showing an example of the configuration of the in-vehicle battery charging device according to the first embodiment when a cross section taken along line XY shown in FIG. FIG. 5A is a block diagram illustrating an example of functional blocks of an in-vehicle battery charging apparatus in which a conversion unit is added to the in-vehicle battery charging apparatus according to Embodiment 1. FIG. 5B is an outline view illustrating an example of an arrangement relationship among the conversion unit, the step-down unit, and the filter unit in the in-vehicle battery charging device illustrated in FIG. 5A.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an example of the functional block configuration of the in-vehicle battery charging device 1 according to the first embodiment.
With reference to FIG. 1, the functional block configuration of the in-vehicle battery charger 1 according to the first embodiment will be described.

The in-vehicle battery charging device 1 includes a step-down unit 22 and a filter unit 3.

The step-down unit 22 is a circuit that steps down the voltage output from the traveling battery 98 when the auxiliary battery 99 is charged. The step-down unit 22 steps down the voltage output from the traveling battery 98 and charges the auxiliary battery 99 by, for example, a switching method represented by a chopper method.
The traveling battery 98 is, for example, a high-voltage secondary battery having an output voltage of about 400 volts, which is composed of a lithium ion battery. The traveling battery 98 is a battery that supplies electric power for driving a motor mainly when the vehicle travels.
The auxiliary battery 99 is, for example, a low-voltage secondary battery having an output voltage of about 12 volts, which is composed of a lead storage battery. The auxiliary battery 99 is a battery that mainly supplies electric power for operating on-vehicle electrical equipment such as a hybrid system and a navigation system.

The filter unit 3 is a magnetic noise filter that is provided between the step-down unit 22 and the traveling battery 98 and that reduces magnetic noise generated when the voltage output from the traveling battery 98 is stepped down. . The filter unit 3 has two coils 33, and the two coils 33 form a common mode choke coil 34 described later.

The step-down unit 22 and the filter unit 3 are mounted on a substrate 2 shown in FIG.
The filter unit 3 includes a Y capacitor 35 and an X capacitor 37 mounted on the substrate 2 in order to remove noise.

FIG. 2 is an outline view showing an example of the configuration of the substrate 2 in the in-vehicle battery charging device 1 according to Embodiment 1 as viewed from the direction perpendicular to the substrate surface.
FIG. 3 shows an example of a configuration in which the filter unit 3 in the in-vehicle battery charging device 1 according to the first embodiment is fixed to the substrate 2 shown in FIG. 2 as viewed from the direction orthogonal to the substrate surface. FIG.
4 is an outline view showing an example of the configuration of the in-vehicle battery charging device 1 according to the first embodiment when the cross section along the line segment XY shown in FIG.
The configuration of the in-vehicle battery charging device 1 according to the first embodiment will be described with reference to FIGS.

The in-vehicle battery charging device 1 includes a substrate 2, a heat radiating part 11, a heat radiating member 12, a filter part 3, a container 13, a second heat radiating member 14, and a step-down part 22. Although not shown in FIGS. 2, 3, and 4, the step-down unit 22 is mounted on the substrate 2 on the right side of the drawings in FIGS. 3 and 4, for example.

The substrate 2 is a wiring substrate that performs electrical wiring. The substrate 2 has a hole 21.
The heat radiating part 11 faces the substrate 2. The heat radiating part 11 is, for example, a part of an aluminum die-cast case that accommodates the substrate 2. The heat radiating part 11 releases a part of the heat generated inside the in-vehicle battery charger 1 to the outside. For example, as shown in FIG. 4, the heat radiating unit 11 may be water-cooled by cooling water flowing in the cooling water channel 19.
The heat radiating member 12 is, for example, a heat radiating sheet that faces the hole portion 21 and is disposed on the substrate 2 side of the heat radiating portion 11. The heat dissipation member 12 is in close contact with the heat dissipation portion 11. The heat generated by the filter unit 3 is conducted to the heat radiating unit 11 through the heat radiating member 12 and is radiated by the heat radiating unit 11.

The filter unit 3 includes an inductor 31 including a coil 33 and a magnetic core 32. The coil 33 forms a common mode choke coil 34. The common mode choke coil 34 has a doughnut-shaped magnetic core 32 as a core, a conductive wire 36 wound around one portion of the magnetic core 32, and other portions facing the part of the magnetic core 32. It has the coil | winding conducting wire 36 and the two coils 33 formed by. In FIG. 3, a portion that looks like a rib is a coil 33. Each coil 33 is wound in such a direction that the directions of magnetic flux generated by the electromagnetic induction phenomenon when currents flow through the respective coils 33 simultaneously are opposite to each other. The filter unit 3 is fixed to the substrate 2 with screws, bolts, or the like, and heat generated in the inductor 31 is radiated to the heat radiating unit 11 through the hole 21 and the heat radiating member 12 of the substrate 2.

A part of the inductor 31 protrudes toward the heat dissipation part 11 through the hole 21 of the substrate 2. By comprising in this way, the vehicle-mounted battery charging device 1 can be reduced in size in the direction orthogonal to the substrate surface. Since the in-vehicle battery charger 1 is often disposed under a vehicle seat or a rear cargo room, downsizing in a direction orthogonal to the board surface is particularly effective.

The container 13 is a non-conductive member that houses a part of the inductor 31 therein. The container 13 is made of ceramics having high thermal conductivity such as aluminum nitride and silicon carbide. Further, the container 13 is filled with a second heat radiating member 14. The 2nd heat radiating member 14 is formed, for example with silicone with high heat conductivity. The second heat radiating member 14 is in contact with the inductor 31 and the container 13 accommodated in the container 13. Since a large-capacity current flows through the coil 33, it is common to use a thick conductive wire 36 having a wire diameter of, for example, 1.6 mm, as the conductive wire 36 used for the coil 33. It is difficult to obtain a sufficient contact surface between them. However, as the container 13 is filled with the second heat radiating member 14 as described above, the heat generated in the inductor 31 is reliably transmitted to the container 13 via the second heat radiating member 14. Further, since the second heat radiating member 14 is made of silicone, the vibration resistance is improved, and the heat generated in the inductor 31 is stably passed through the second heat radiating member 14 even when the vehicle is traveling. Will be transmitted reliably.

The container 13 includes a flange portion 15. The flange portion 15 is fixed to the substrate 2 in a state where the outside of the container 13 and the heat dissipation member 12 are in contact with each other. By configuring in this way, not only the filter unit 3 but also the container 13 is fixed to the substrate 2, so that the vibration resistance is improved and the filter unit 3 can be prevented from being peeled off from the substrate 2. Further, with this configuration, the heat generated in the inductor 31 can be reliably transmitted to the heat radiating portion 11 via the second heat radiating member 14, the container 13, and the heat radiating member 12 even when the vehicle is traveling. The heat is released. As shown in FIG. 1, the Y capacitor 35 is originally mounted on the substrate 2 between the inductor 31 and the heat radiating part 11. By configuring in this way, the inductor 31, the heat radiating part 11, And the noise filter effect of the inductor 31 is improved.

As mentioned above, although the structure of the vehicle-mounted battery charging device 1 which concerns on Embodiment 1 was demonstrated using FIG.2, 3,4, it is not this limitation.

For example, the flange portion 15 of the container 13 is not an essential configuration. For example, the container 13 may be fixed to the heat radiating part 11 with the heat radiating member 12 disposed in the heat radiating part 11 interposed therebetween without providing a flange for fixing to the substrate 2.

For example, the container 13 and the second fixing member are not essential components. For example, the heat radiating member 12 disposed in the heat radiating portion 11 may directly contact the inductor 31.

Also, for example, a part of the inductor 31 does not need to protrude toward the heat radiating part 11 through the hole 21 of the substrate 2. If the structure is such that heat generated in the inductor 31 is radiated to the heat radiating part 11 through the hole 21 of the substrate 2 and the heat radiating member 12, a part of the inductor 31 does not necessarily protrude from the hole 21 of the substrate 2. It doesn't matter.

As described above, the on-vehicle battery charging device 1 is disposed on the substrate 2 side of the heat dissipation portion 11, the substrate 2 having the hole portion 21, the heat dissipation portion 11 facing the substrate 2, and the hole portion 21. A filter unit 3 provided between wires of the heat dissipating member 12, a step-down unit 22 that steps down the voltage output from the traveling battery 98 when charging the auxiliary battery 99, and the traveling battery 98; The filter unit 3 includes an inductor 31, is fixed to the substrate 2, and heat generated in the inductor 31 is radiated to the heat radiating unit 11 through the hole 21 and the heat radiating member 12.
By configuring in this way, it is possible to suppress a decrease in inductance of the inductor 31 by suppressing a temperature increase of the magnetic core 32, so that the performance of suppressing the magnetic noise in the filter unit 3 can be maintained.

The in-vehicle battery charging device 1 according to Embodiment 1 may include a conversion unit 23 that converts a voltage output from the AC power source 97 into a DC voltage when the traveling battery 98 is charged.

FIG. 5A is a block diagram illustrating an example of functional blocks of the in-vehicle battery charging apparatus 1 in which a conversion unit 23 is added to the in-vehicle battery charging apparatus 1 according to Embodiment 1 described so far.
In FIG. 5A, an AC power source 97 is a household power source having an AC voltage of 100 to 220 volts, for example. When the vehicle is a hybrid vehicle such as a plug-in hybrid vehicle, the AC power source 97 is not limited to a household power source, but is driven by the rotation of a motor driven by chemical energy such as gasoline or light oil when the vehicle travels. Or an alternator.
The converter 23 converts the AC voltage output from the AC power source 97 into a DC voltage, and charges the traveling battery 98.

FIG. 5B is an outline view showing an example of an arrangement relationship among the conversion unit 23, the step-down unit 22 and the filter unit 3 in the in-vehicle battery charging device 1 shown in FIG. 5A.
In FIG. 5B, the in-vehicle battery charging device 1 includes a conversion unit 23, a step-down unit 22, and a filter unit 3 that are stacked. As shown in FIG. 5B, the inside of the in-vehicle battery charging device 1 includes a converter unit 25 and a step-down unit storage unit between the converter 23, the step-down unit 22 and the filter unit 3 by the heat radiating unit 11. 24 may be partitioned.
Since the in-vehicle battery charging device 1 is often disposed under a vehicle seat or a rear cargo room, particularly when the conversion unit 23, the step-down unit 22, and the filter unit 3 are stacked and disposed, It is necessary to reduce the size in the direction in which the portion 22 and the filter portion 3 are laminated, and a structure in which a part of the inductor 31 protrudes toward the heat radiating portion 11 through the hole portion 21 of the substrate 2 is effective.

It should be noted that within the scope of the invention, the present invention can be modified with any component in the embodiment or omitted in the embodiment.

The present invention can be applied to an in-vehicle battery charger.

DESCRIPTION OF SYMBOLS 1 Vehicle-mounted battery charging device, 2 board | substrate, 3 filter part, 11 heat radiation part, 12 heat radiation member, 13 container, 14 2nd heat radiation member, 15 flange part, 19 cooling water channel, 21 hole part, 22 pressure | voltage fall part, 23 conversion part , 24 step-down part accommodating part, 25 converting part accommodating part, 31 inductor, 32 magnetic core, 33 coil, 34 common mode choke coil, 35 Y capacitor, 36 conductor, 37 X capacitor, 97 AC power supply, 98 traveling battery, 99 Auxiliary battery.

Claims (5)

1. A substrate having a hole;
   A heat dissipating part facing the substrate;
   A heat dissipating member facing the hole and disposed on the substrate side of the heat dissipating part,
   A step-down unit that steps down the voltage output from the traveling battery when charging the auxiliary battery, and a filter unit provided between the wirings of the traveling battery, including an inductor, and fixed to the substrate And the filter part in which heat generated in the inductor is radiated to the heat radiating part through the hole and the heat radiating member,
   An in-vehicle battery charger characterized by comprising:
2. The in-vehicle battery charging device according to claim 1, wherein a part of the inductor protrudes toward the heat radiating part through the hole.
3. The conversion unit that converts a voltage output from an AC power source into a DC voltage when charging the battery for traveling, the step-down unit, and the filter unit are arranged in a stacked manner. In-vehicle battery charger.
4. A container in which a part of the inductor is housed and a second heat dissipating member is filled;
   The second heat dissipating member is in contact with the inductor and the container;
   The in-vehicle battery charger according to claim 2.
5. The container includes a flange portion,
   The in-vehicle battery charging device according to claim 4, wherein the flange portion is fixed to the substrate in a state where the outside of the container is in contact with the heat radiating member.

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