JP6727475B2 - Vehicle battery charger - Google Patents

Description

The present invention relates to a vehicle battery charger.

BACKGROUND OF THE INVENTIONVehicles such as electric vehicles and plug-in hybrid vehicles mainly use a driving battery that outputs high-voltage DC power as a power source for driving power, and a low-voltage DC battery that is mainly used as a power source for operating in-vehicle electrical equipment. And an auxiliary battery for outputting electric power of voltage. 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 electric power of the traveling battery. When charging the auxiliary battery, a current flows from the running battery to the DC-DC converter, but this current causes magnetic noise. A filter is generally provided to suppress this magnetic noise, but the magnetic noise generated is increasing with the increase in the voltage of the electric power output from the battery for running and the increase in the current. Further technical studies on the filter section are being conducted.

For example, in Patent Document 1, an input terminal, an output terminal, a power converter 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, the input terminal and the power The power conversion unit and the noise filter are provided with a noise filter unit connected between the conversion unit, a shield plate having an insulator on both sides, a power conversion unit, the noise filter unit, and a metal case that houses the shield plate. There is disclosed a DC-DC converter in which the negative electrode side output end of the power conversion unit, the shield plate and the metal case are electrically connected to each other via a shield plate.

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 properties as a magnetic material when the magnetic material itself exceeds a certain temperature. Therefore, when the temperature of the magnetic core rises due to the Joule heat generated by the coil, the inductance of the inductor decreases and it becomes impossible to sufficiently suppress magnetic noise.
In the DC-DC converter disclosed in Patent Document 1, since the Joule heat generated by the coil cannot be sufficiently radiated, 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.

The present invention is to solve the above-mentioned problems, and an object of the present invention is to provide an on-vehicle battery charger capable of suppressing the temperature rise of the magnetic core and maintaining the performance of suppressing the magnetic noise due to the inductor. I am trying.

An on-vehicle battery charging device according to the present invention includes a board having a hole, a heat radiating section facing the board, a heat radiating member facing the hole and arranged on the board side of the heat radiating section, and an auxiliary battery. A step-down unit that steps down the voltage output from the running battery when charging, and a filter unit that is provided between the wiring of the running battery and has an inductor, and a portion of the inductor passes through the hole. When the battery for charging is charged, the filter is fixed to the substrate so as to project toward the heat radiating unit, and the heat generated in the inductor is radiated to the heat radiating unit through the hole and the heat radiating member. The conversion unit that converts the voltage output from the AC power supply into the DC voltage, the step-down unit, and the filter unit are stacked and arranged .

According to the present invention, the performance of suppressing the temperature rise of the magnetic core and suppressing the magnetic noise due to the inductor can be maintained.

FIG. 3 is a block diagram showing an example of a configuration of functional blocks of the vehicle-mounted battery charging device according to the first embodiment. FIG. 3 is an external view showing an example of a configuration of the board in the vehicle-mounted battery charging device according to the first embodiment as seen from a direction orthogonal to the board surface. FIG. 3 is an external view showing an example of a configuration in which the filter unit in the vehicle-mounted battery charging device according to the first embodiment is fixed to the substrate shown in FIG. 2 as seen from a direction orthogonal to the substrate surface. FIG. 4 is an external view showing an example of a configuration of the vehicle-mounted battery charging device according to the first embodiment as seen from a direction of an arrow Z in a cross section taken along line XY shown in FIG. 3. FIG. 5A is a block diagram showing an example of functional blocks of a vehicle-mounted battery charging device in which a conversion unit is added to the vehicle-mounted battery charging device according to the first embodiment. FIG. 5B is an external view showing an example of the positional relationship between the conversion unit, the step-down unit, and the filter unit in the vehicle-mounted battery charging device shown in FIG. 5A.

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

Embodiment 1.
FIG. 1 is a block diagram showing an example of the configuration of functional blocks of the vehicle-mounted battery charging device 1 according to the first embodiment.
The configuration of the functional blocks of the on-vehicle battery charging device 1 according to the first embodiment will be described with reference to FIG.

The on-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 charging the auxiliary battery 99. The step-down unit 22 steps down the voltage output from the traveling battery 98 to charge the auxiliary battery 99 by a switching method represented by a chopper method, for example.
The traveling battery 98 is, for example, a high-voltage secondary battery having an output voltage of about 400 V, which is composed of a lithium ion battery. The traveling battery 98 is a battery that mainly supplies electric power for driving the motor when the vehicle travels.
The auxiliary battery 99 is, for example, a low-voltage secondary battery having an output voltage of about 12 V, which is composed of a lead storage battery. The auxiliary battery 99 is a battery that mainly supplies electric power for operating in-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 wiring 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 reduced. .. 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. 2 described later.
The filter unit 3 has a Y capacitor 35 and an X capacitor 37 mounted on the substrate 2 to remove noise.

FIG. 2 is an external view showing an example of a configuration of the board 2 in the vehicle-mounted battery charging device 1 according to the first embodiment as seen from a direction perpendicular to the board surface.
FIG. 3 is an external view showing an example of a configuration in which the filter unit 3 in the vehicle-mounted battery charging device 1 according to the first embodiment is fixed to the substrate 2 shown in FIG. It is a figure.
FIG. 4 is an external view showing an example of the configuration of the on-vehicle battery charging device 1 according to the first embodiment when the cross section taken along the line XY shown in FIG. 3 is viewed from the arrow Z.
The configuration of the on-vehicle battery charging device 1 according to the first embodiment will be described with reference to FIGS.

The on-vehicle battery charging device 1 includes a substrate 2, a heat dissipation part 11, a heat dissipation member 12, a filter part 3, a container 13, a second heat dissipation 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.

The board 2 is a wiring board for electrical wiring. The substrate 2 has a hole 21.
The heat dissipation part 11 faces the substrate 2. The heat dissipation portion 11 is, for example, a part of an aluminum die casting case that houses the substrate 2. The heat dissipation part 11 radiates a part of the heat generated inside the on-vehicle battery charging device 1 to the outside. The heat dissipation part 11 may be water-cooled by the cooling water flowing in the cooling water passage 19 as shown in FIG. 4, for example.
The heat dissipation member 12 is, for example, a heat dissipation sheet that is arranged on the substrate 2 side of the heat dissipation unit 11 so as to face the hole 21. The heat dissipation member 12 is in close contact with the heat dissipation unit 11. The heat generated by the filter unit 3 is conducted to the heat radiating unit 11 via the heat radiating member 12 and radiated by the heat radiating unit 11.

The filter unit 3 has 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 conducting wire 36 wound around one part of the magnetic core 32 with the magnetic core 32 having a donut shape as a core, and another part facing the part of the magnetic core 32. It has a coiled wire 36 and two coils 33 formed by. In FIG. 3, the portion that looks like a rib is the coil 33. The winding directions of the respective coils 33 are such that the directions of the magnetic flux generated by the electromagnetic induction phenomenon when the currents simultaneously flow through the respective coils 33 are opposite to each other. The filter unit 3 is fixed to the substrate 2 with screws, bolts, etc., and the heat generated in the inductor 31 is radiated to the heat radiating unit 11 via the hole 21 of the substrate 2 and the heat radiating member 12.

A part of the inductor 31 protrudes toward the heat dissipation portion 11 through the hole 21 of the substrate 2. With this configuration, the vehicle-mounted battery charging device 1 can be downsized in the direction orthogonal to the substrate surface. Since the on-vehicle battery charging device 1 is often arranged under the seat of the vehicle or the rear cargo room, downsizing in the direction orthogonal to the substrate 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, for example, ceramics having high thermal conductivity such as aluminum nitride and silicon carbide. Further, the container 13 is filled with the second heat radiation member 14. The second heat dissipation member 14 is formed of, for example, silicone having high thermal conductivity. The second heat radiation member 14 contacts the inductor 31 housed in the container 13 and the container 13. Since a large amount of electric current flows through the coil 33, the conductor 36 used for the coil 33 is generally a thick conductor 36 having a wire diameter of, for example, 1.6 mm and is used. It is difficult to obtain a sufficient contact surface between them. However, by filling the container 13 with the second heat dissipation member 14 as described above, the heat generated in the inductor 31 is reliably transferred to the container 13 via the second heat dissipation member 14. Further, since the second heat radiating member 14 is formed of silicone, the vibration resistance is improved, and the heat generated in the inductor 31 is stably transmitted through the second heat radiating member 14 to the container 13 while the vehicle is traveling. Will be reliably transmitted to.

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. With this configuration, not only the filter portion 3 but also the container 13 is fixed to the substrate 2, so that the vibration resistance is improved and the filter portion 3 can be prevented from peeling off from the substrate 2. Further, with such a configuration, the heat generated in the inductor 31 is reliably transmitted to the heat radiating portion 11 via the second heat radiating member 14, the container 13, and the heat radiating member 12 while the vehicle is traveling. , 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 portion 11. However, with this configuration, the Y capacitor 35 and the heat radiating portion 11 are further connected. The stray capacitance between the two increases, and the noise filter effect of the inductor 31 improves.

The configuration of the on-vehicle battery charging device 1 according to the first embodiment has been described above with reference to FIGS. 2, 3, and 4, but the configuration is not limited to this.

For example, the flange portion 15 of the container 13 is not an essential component. For example, the container 13 may be fixed to the heat radiating portion 11 by sandwiching the heat radiating member 12 arranged in the heat radiating portion 11 without providing a flange for fixing the container 13.

Moreover, for example, the container 13 and the second fixing member are not essential configurations. For example, the heat dissipation member 12 arranged in the heat dissipation unit 11 may directly contact the inductor 31.

Further, for example, a part of the inductor 31 does not have to pass through the hole 21 of the substrate 2 and project toward the heat dissipation unit 11. As long as the heat generated in the inductor 31 is radiated to the heat radiating portion 11 via 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 arranged on the substrate 2 having the hole portion 21, the heat radiating portion 11 that faces the substrate 2, and the hole portion 21 that faces the heat radiating portion 11 on the substrate 2 side. The filter unit 3 provided between the heat dissipation member 12, the voltage lowering unit 22 that lowers the voltage output from the traveling battery 98 when charging the auxiliary battery 99, and the wiring between the traveling battery 98, The filter unit 3 has the inductor 31, is fixed to the substrate 2, and the heat generated in the inductor 31 is radiated to the heat radiating unit 11 via the hole 21 and the heat radiating member 12.
With this configuration, it is possible to suppress the decrease in the inductance of the inductor 31 by suppressing the temperature rise of the magnetic core 32, so that the performance of suppressing the magnetic noise in the filter unit 3 can be maintained.

The vehicle-mounted battery charging device 1 according to the first embodiment may include the conversion unit 23 that converts the voltage output from the AC power supply 97 into the DC voltage when the traveling battery 98 is charged.

FIG. 5A is a block diagram showing an example of functional blocks of the vehicle-mounted battery charging apparatus 1 in which the conversion unit 23 is added to the vehicle-mounted battery charging apparatus 1 according to the first embodiment described above.
In FIG. 5A, the AC power supply 97 is, for example, a household power supply having an AC voltage of 100 V to 220 V. 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, and uses the rotation of a motor driven by chemical energy such as gasoline or light oil as the power source when the vehicle travels. , It may be an alternator.
The conversion unit 23 converts the AC voltage output by the AC power supply 97 into a DC voltage and charges the traveling battery 98.

FIG. 5B is an outline view showing an example of the positional relationship between the conversion unit 23, the step-down unit 22, and the filter unit 3 in the vehicle-mounted battery charging device 1 shown in FIG. 5A.
In FIG. 5B, the in-vehicle battery charging device 1 includes the conversion unit 23, the step-down unit 22, and the filter unit 3 which are stacked. As shown in FIG. 5B, inside the vehicle-mounted battery charger 1, between the conversion unit 23 and the step-down unit 22 and the filter unit 3, the conversion unit accommodation unit 25 and the step-down unit accommodation unit 25 are provided by the heat dissipation unit 11 and the like. It may be divided into 24.
Since the on-vehicle battery charging device 1 is often arranged under the seat of the vehicle or under the rear cargo room, when the converter 23, the step-down part 22 and the filter part 3 are stacked and arranged, the step-down voltage is reduced. It is necessary to reduce the size in the direction in which the part 22 and the filter part 3 are stacked, and a structure in which a part of the inductor 31 projects toward the heat dissipation part 11 through the hole part 21 of the substrate 2 is effective.

In addition, within the scope of the present invention, it is possible to modify any of the constituent elements of the embodiment or omit any of the constituent elements of the embodiment.

It can be applied to the vehicle-mounted battery charging device according to the present invention.

DESCRIPTION OF SYMBOLS 1 Vehicle-mounted battery charger, 2 Board, 3 Filter part, 11 Heat dissipation part, 12 Heat dissipation part, 13 Container, 14 2nd heat dissipation part, 15 Flange part, 19 Cooling water channel, 21 Hole part, 22 Step-down 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 lead wire, 37 X capacitor, 97 AC power supply, 98 running battery, 99 Battery for auxiliary equipment.

Claims (3)

A substrate having holes,
A heat dissipation portion facing the substrate;
A heat radiating member facing the hole and arranged on the substrate side of the heat radiating portion;
A filter unit provided between a wiring for connecting the battery for traveling and a voltage lowering unit for reducing the voltage output by the battery for traveling when charging the battery for auxiliary equipment, and having an inductor. The part is fixed to the substrate so as to project toward the heat dissipation part through the hole part, and the heat generated in the inductor is radiated to the heat dissipation part through the hole part and the heat dissipation member. A filter part,
Equipped with
A converter for converting voltage AC power is output when charging the driving battery to a DC voltage, for placing a car the step-down unit and the filter unit, is you being disposed by stacking Battery charger. A container that accommodates a part of the inductor therein and is filled with a second heat dissipation member is provided.
The second heat dissipation member is in contact with the inductor and the container,
The in-vehicle battery charging device according to claim 1 . The container includes a flange portion,
The in-vehicle battery charger according to claim 2 , wherein the flange portion is fixed to the substrate in a state where the outside of the container and the heat dissipation member are in contact with each other.

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