JP5981406B2 - Power supply device - Google Patents

Description

  The present invention relates to a power supply device that supplies electric power from a battery to an electric load, and more particularly to a power supply device that includes a voltage conversion device that stabilizes a supply voltage to the electric load.

  A vehicle is equipped with a control unit such as an ECU and various electric loads such as a lighting fixture, a display, a motor, and a solenoid, and it is necessary to supply electric power to each electric load with a stable voltage. Therefore, a DC / DC converter has been conventionally used as a voltage conversion device that controls so that a stable voltage power is supplied to the load, and the voltage is stepped up and down by the DC / DC converter to stabilize the voltage. ing.

  Also, in response to the electrification and increase in capacity of onboard equipment such as EPS and electric air conditioners, the voltage of the battery is boosted by a DC / DC converter to supply power to the motor inverter. Alternatively, in a 42V automobile power supply system including a 42V main battery and a 14V sub battery, a DC / DC converter is connected between two batteries for voltage conversion (step-up / step-down). Furthermore, in vehicles equipped with an idling stop system (ISS) that automatically stops the engine temporarily when the vehicle is temporarily stopped due to a signal, etc., a large current is supplied from the battery to the starter when the engine is restarted. For this reason, the voltage is boosted by a DC / DC converter to supply power to each electric load.

  By the way, since the DC / DC converter is provided with an inductor or the like for voltage conversion, there is a problem that when this operates, heat is generated and a relatively large power loss occurs. Therefore, for the purpose of dissipating heat during operation, heat dissipating parts such as heat dissipating plates and heat dissipating cases are installed in the DC / DC converter, which increases the size of the DC / DC converter.

  In order to reduce the power loss in the DC / DC converter, in Patent Document 1, when it is assumed that the battery voltage is lowered, the DC / DC converter boosts the voltage and supplies power to the load. When the battery voltage can be applied to the load, the power supply device is configured to supply power through the switch means without going through the DC / DC converter.

  Patent Document 2 describes a control method for stably performing idling stop using voltage compensation means as a voltage converter in a vehicle equipped with an idling stop system. Here, after a predetermined engine start condition is established and the starter means is operated, when the battery voltage falls below a predetermined set value, the voltage compensation means is operated to stabilize the voltage. Further, the operation of the voltage compensating means is prohibited when a predetermined time has elapsed since the engine was stopped, or when the starter means is not activated even when the starter means is actuated.

JP 2003-237501 A JP 2002-38984 A

  However, in the power supply device described in Patent Document 1, when it is not necessary to use a DC / DC converter, switch means for bypassing the DC / DC converter is necessary so that power can be supplied to the load without going through the DC / DC converter. However, there is a problem that heat is generated when the switch means is operated. In order to sufficiently dissipate the heat generated by the DC / DC converter and the heat generated by the switch means, it is necessary to dispose heat radiating components for the heat generation of each of the DC / DC converter and the switch means. There exists a problem that a power supply device will enlarge as a whole.

  Further, it is described that, in a vehicle equipped with the idling stop system described in Patent Document 2, the operation of the voltage compensation means is prohibited in a situation where the battery is extremely consumed when idling is stopped. However, simply disabling the operation of the voltage compensation means in consideration of the heat dissipation performance when the voltage compensation means is activated, the heat dissipation component cannot be reduced in size, which leads to the downsizing of the power supply device. Absent.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a power supply device that supplies power to an electric load with a stable voltage, has high heat dissipation, and is easy to downsize. .

In order to solve the above problems, a first aspect of a power supply device of the present invention is a power supply device used in a vehicle equipped with a battery and a plurality of electric loads, and is connected to at least one of the electric loads. Boosting or stepping down the voltage of the power supplied to at least one of the load power supply unit formed on the metal core substrate and the electric load connected to the load power supply unit. And a voltage conversion unit formed on a substrate separate from the metal core substrate, and further, heat transfer is performed between the voltage conversion unit and the load power supply unit. comprises a thermally bonded structure, the heat coupling structure is characterized in that the the metal core substrate, a connector and the substrate separate from the said metal core substrate, the thermally connects and electrically

  According to another aspect of the power supply apparatus of the present invention, the voltage conversion unit may convert the voltage of the power supplied to the electric load within a predetermined voltage range when the voltage of the battery fluctuates below a predetermined value when the engine of the vehicle is started. It is characterized by being stabilized.

  According to another aspect of the power supply apparatus of the present invention, the load power supply unit is configured to operate the connection destination without operating the voltage conversion unit when a load current supplied to the electrical load to be connected is higher than a predetermined value. The electric load is supplied to the electric load.

  According to another aspect of the power supply apparatus of the present invention, a temperature sensor that measures the temperature of the load power supply unit, and the temperature measurement value is input from the temperature sensor to determine whether the voltage conversion unit is operable or limited. And a control unit that controls whether to operate, stop, or operate the voltage conversion unit according to a determination result by the determination unit. And

  According to another aspect of the power supply device of the present invention, a current sensor that measures a load current of the load power supply unit, and whether or not the voltage conversion unit operates or is limited by inputting the current measurement value from the current sensor. A determination unit that determines, and a control unit that controls whether to operate, stop, or operate the voltage conversion unit according to a determination result by the determination unit. Features.

  ADVANTAGE OF THE INVENTION According to this invention, while supplying power with the stable voltage to an electric load, it can provide the power supply apparatus which has high heat dissipation and is easy to reduce in size.

It is the top view and sectional drawing which show an example of a structure of the power supply device which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structure of the power supply apparatus which concerns on 1st Embodiment. It is the top view and sectional view showing an example of the composition of the power supply device concerning a 2nd embodiment of the present invention. It is a block diagram which shows the structure of the power supply apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the power supply apparatus which concerns on 3rd Embodiment. It is a block diagram which shows the connection state of the wire harness in the conventional power supply device. It is a block diagram which shows the connection state of the wire harness in the power supply device which concerns on 1st Embodiment.

  A power supply device according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. Each component having the same function is denoted by the same reference numeral for simplification of illustration and description. The present invention relates to a power supply device that supplies power to a plurality of electric loads from a battery mounted on a vehicle, and particularly to a vehicle equipped with an electric load that greatly varies a battery voltage, such as an idling stop system. A suitable power supply device is provided. In vehicles equipped with an idling stop system, the battery voltage fluctuates greatly when the engine is restarted.For electric loads that need to be supplied with a stable voltage, a large current is passed in a short time to increase the voltage. A voltage converter for stabilization is used. The voltage conversion device generates a large amount of heat when a large current is passed in a short time.

(First embodiment)
A power supply apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view and a cross-sectional view illustrating an example of the configuration of the power supply apparatus 100 of the present embodiment. The cross-sectional view shown in FIG. 5B is a cross-sectional view taken along the line AA of the plan view shown in FIG. FIG. 2 is a block diagram illustrating a configuration of the power supply apparatus 100. The power supply device 100 includes a load power supply unit 110 for supplying power from the battery 10 to a predetermined electric load 20, and a voltage conversion device 120 for stabilizing the supply voltage to the electric load 20. The voltage conversion device 120 is connected to the load power supply unit 110 via the thermal coupling structure unit 130.

  The load power supply unit 110 is, for example, a junction box (J / B) disposed between the battery 10 and the electric load 20 and is simply referred to as J / B 110 in the following description. In the present embodiment, a substrate with high heat dissipation is used for the substrate 111 of J / B110. Here, as the substrate 111, a metal core substrate having a structure in which a metal plate (metal core) 111a having high thermal conductivity is arranged in the center and sandwiched between resins is used. The board | substrate 111 is not limited to this, For example, the board | substrate provided with the bus-bar or thick copper foil etc. may be sufficient.

  When the battery voltage largely fluctuates, the voltage conversion device 120 increases or decreases the power supply voltage when it is necessary to stabilize the voltage (power supply voltage) of the power supplied to the electric load 20 within a predetermined voltage range. For example, a DC / DC converter is used. Hereinafter, a case where a DC / DC converter is used as the voltage conversion device 120 will be described, and the DC / DC converter 120 is assumed.

  In a vehicle equipped with an idling stop system, a large current is supplied to the starter in order to restart the engine after the idling stop. As a result, the battery voltage temporarily drops greatly. On the other hand, for the electric load 20 that needs to be supplied with a stable voltage, the lowered battery voltage is boosted to a predetermined voltage by the DC / DC converter 120 and supplied with power. Note that the DC / DC converter 120 may not only boost the battery voltage but also step down or both step up and step down.

  When the battery voltage temporarily drops greatly when the engine is restarted, a large current is also temporarily passed through the DC / DC converter 120 in order to stabilize the voltage. Since the DC / DC converter 120 uses a heat generating component 121 such as an inductor, a large amount of heat is generated in the heat generating component 121 for a short time when a large current is temporarily passed.

  In the power supply apparatus 100 of this embodiment, in order to equalize the heat generated in the DC / DC converter 120 and efficiently dissipate the heat, the heat coupling structure 130 is used to generate heat from the DC / DC converter 120. Heat is transferred to B110. As a result, the heat generated by the DC / DC converter 120 is equalized to the J / B 110 and can be dissipated. In FIG. 1, a metal core substrate is also used for the substrate 122 of the DC / DC converter 120. In this case, heat is efficiently transferred from the metal core 122a of the substrate 122 to the metal core 111a of the substrate 111 on the J / B 110 side. The thermal coupling structure 130 is preferably configured as described above.

  Although FIG. 1 shows an example in which a metal core substrate is used as the substrate 122 of the DC / DC converter 120, the present invention is not limited to this, and another heat transfer means for transmitting heat generated in the heat generating component 121 is used. May be provided. In that case, the heat coupling structure 130 may be connected to another heat transfer means of the DC / DC converter 120.

  The thermal coupling structure 130 has a structure that allows good heat transfer between the DC / DC converter 120 and the J / B 110. For example, a heat pipe can be used as the heat coupling structure 130 capable of performing good heat transfer. Or you may form using a heat conductive resin material.

  The thermal coupling structure 130 may be configured to perform good heat transfer between the DC / DC converter 120 and the J / B 110, and to electrically connect the DC / DC converter 120 and the J / B 110. Is possible. In that case, a connector can be used as the thermal coupling structure 130, and a connector with improved heat transfer characteristics can be obtained. As an example, a connector in which the conductor portion is thickened (the cross-sectional area of the conductor is increased) can be obtained. Or it is also possible to set it as the connector provided with the thermal coupling part formed with the metal. By using such a connector, the DC / DC converter 120 can be electrically connected to the J / B 110, and both can be thermally connected to facilitate temperature equalization.

  The power supply device 100 according to the present embodiment can supply power to an electric load with a stable voltage using the DC / DC converter 120, has high heat dissipation, and can be easily downsized. .

(Second Embodiment)
A power supply apparatus according to a second embodiment of the present invention will be described below with reference to FIGS. FIG. 3 is a plan view and a cross-sectional view illustrating an example of the configuration of the power supply device 200 of the present embodiment. The cross-sectional view shown in FIG. 5B is a cross-sectional view taken along the line AA of the plan view shown in FIG. FIG. 4 is a block diagram illustrating a configuration of the power supply apparatus 200. In the power supply device 200 of the present embodiment, a relay 212 for a heat generating component is arranged in the J / B 210.

  The relay 212 is used, for example, to turn on / off the use of the DC / DC converter 120. That is, when the supply voltage to the electric load 20 is stabilized using the DC / DC converter 120, the relay 212 is brought into a connection state in which electric power is supplied from the J / B 210 to the electric load 20 via the DC / DC converter 120. Is activated. On the other hand, when there is no need to stabilize the supply voltage to the electric load 20 or when the operation of the DC / DC converter 120 is not possible, the relay 212 is operated in a connection state that bypasses the DC / DC converter 120.

  Generally, in a vehicle equipped with an idling stop system, idling stop is not performed when power supply to an electric load is excessive. This is because if the idling stop is performed when the power supply to the electric load is large, the charging rate of the battery decreases while the engine is stopped, and the power supply necessary for the electric load may not be performed when the engine is restarted. Because there is. In the power supply apparatus 200 of the present embodiment, when the idling stop is not performed, the relay 212 can be operated so as to bypass the DC / DC converter 120.

  When the relay 212 is operated by passing a current in order to switch the connection state of the DC / DC converter 120, the relay 212 generates heat temporarily, and this heat is transmitted to the substrate 211 to be equalized. Since the relay 212 and the DC / DC converter 120 do not operate simultaneously, the heat generated from the relay 212 and the heat generated from the DC / DC converter 120 are not transmitted to the substrate 211 at the same time. Accordingly, the substrate 211 only needs to have a heat dissipation characteristic that can radiate heat by equalizing the larger one of the heat generation amount from the relay 212 and the heat generation amount from the DC / DC converter 120, and the substrate 211 is larger. There is no need to

  In the above, the case where the relay 212 is provided on the board 211 and the heat generated from the relay 212 is soaked has been described. However, the invention is not limited to the heat generated from the relay 212. For example, a circuit pattern on the board 211 (not shown) Alternatively, a large current may flow temporarily to generate heat. In this case, as long as the heat generation of the substrate 211 does not occur simultaneously with the heat generation in the DC / DC converter 120, it is possible to dissipate heat by equalizing the temperature as described above, and it is not necessary to increase the size of the substrate 211.

  As described above, in general, in a vehicle equipped with an idling stop system, idling stop is not performed when power supply to an electric load is excessive. When the power supply to the electric load is large, the current flowing through the substrate 211 other than the DC / DC converter 120 of the power supply device 200 increases. Therefore, heat is transferred from the substrate 211 to the DC / DC converter 120 and is soaked. Conversely, when the power supply to the electric load is small, idling stop is performed. In this case, the current flowing through the substrate 211 other than the DC / DC converter 120 of the power supply device 200 is small, and there is a thermal margin. Therefore, even if the load of the DC / DC converter 120 increases and heat is generated when the engine is restarted, the heat of the DC / DC converter 120 is transferred to the substrate 211 and is equalized. That is, in a vehicle equipped with an idling stop system, in addition to the relay 212, control is performed so that excessive heat generation of the substrate 211 does not occur simultaneously with excessive heat generation in the DC / DC converter 120. An effect of 200 miniaturization can be obtained.

  In the power supply apparatus 200 according to the present embodiment, even when a large amount of heat is generated on the substrate 211 side, as long as this does not occur simultaneously with the heat generation at the DC / DC converter 120, the power supply apparatus 100 according to the first embodiment Similarly, the substrate 211 can be soaked without increasing its size. The power supply device 200 according to the present embodiment has a configuration that realizes high heat dissipation and can be easily reduced in size, like the power supply device 100 according to the first embodiment.

(Third embodiment)
A power supply device according to a third embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a block diagram showing the configuration of the power supply apparatus 300 of this embodiment. Also in the power supply device 300 of this embodiment, as with the power supply device 200 of the second embodiment, current flows through the relay 312 on the J / B 310 side and heat is temporarily generated. However, the heat generation from the relay 312 is not limited, and any heat generation that temporarily generates large heat on the substrate 211 side may be used.

  In the power supply device 300 of this embodiment, a temperature sensor 341 for measuring the temperature of the substrate 311 in order to prevent heat generation on the substrate 311 by the relay 312 and heat generation in the DC / DC converter 120 from occurring simultaneously. , A determination unit 342 for determining whether or not the DC / DC converter 120 can operate, and a control unit 343 that controls the operation of the DC / DC converter 120. The temperature of the substrate 311 measured by the temperature sensor 341 is input to the determination unit 342 and used for predetermined determination.

  Although the temperature sensor 341 is provided here to measure the temperature of the substrate 311, the present invention is not limited to this. For example, a current sensor that measures the current flowing through the substrate 311 is provided, and the current measured by the current sensor is measured. May be used for determination by the determination unit 342.

  The determination unit 342 receives the temperature of the substrate 311 from the temperature sensor 341, and determines whether this exceeds a predetermined threshold temperature. If it is determined that the temperature of the substrate 311 exceeds the predetermined threshold temperature, the determination unit 342 outputs a request signal that prevents the control unit 343 from operating the DC / DC converter 120. Alternatively, a request signal for limiting the operation of the DC / DC converter 120 is output to the control unit 343 according to the degree to which the temperature of the substrate 311 exceeds the threshold temperature.

  The control unit 343 controls the DC / DC converter 120 so as not to operate the DC / DC converter 120 or limit the operation in accordance with the request signal input from the determination unit 342. When the control unit 343 inputs a request signal that does not operate the DC / DC converter 120, the relay 312 bypasses the DC / DC converter 120 instead of directly controlling the DC / DC converter 120 not to operate. May be controlled.

  Further, when the control unit 343 inputs a request signal for limiting the operation of the DC / DC converter 120, the output voltage of the DC / DC converter 120 is reduced from, for example, 12V to 11V, or the allowable current is reduced from 5A to 4A. And so on. Thereby, the electric energy consumed by the DC / DC converter 120 is reduced, and the heat generation in the DC / DC converter 120 can be reduced.

  In the power supply apparatus 300 of this embodiment, by having the above-described configuration, it is possible to control so that large heat generation on the substrate 311 side and heat generation in the DC / DC converter 120 do not occur simultaneously. ing. Thereby, the substrate 311 can be soaked without increasing its size. The power supply device 300 according to the present embodiment has a configuration that achieves high heat dissipation and can be easily reduced in size, like the power supply device 100 according to the first embodiment.

  The power supply devices 100, 200, and 300 of the first to third embodiments described above are both connected by connecting the DC / DC converter 120 to the J / B 110, 210, or 310 using the thermal coupling structure 130. Are integrated. On the other hand, in the conventional power supply apparatus, for example, as shown in FIG. 6, the DC / DC converter 92 is connected to the J / B 91 by the wire harness 93. In the conventional example shown in FIG. 2A, the wire harness 93 connects the J / B 91 and the DC / DC converter 92, and the DC / DC converter 92 and the electric load 20, respectively. Further, in another conventional example shown in FIG. 2B, the connection between the DC / DC converter 92 and the electric load 20 is connected by the wire harness 93 via the J / B 91, and the wire harness 93 Was even longer.

  Since the wire harness 93 may act as an antenna that emits noise, the longer the wire harness 93 is, the more likely it is to be affected by noise. In addition, there is a problem that the power supply device becomes larger or heavier in order to secure a wiring space for the wire harness 93.

  On the other hand, in the power supply devices 100, 200 and 300 of the above embodiment, the J / B 110 or 210 or 310 and the DC / DC converter 120 are integrated, so that the J / B 110 or the like and the DC / DC converter 120 are integrated. A wire harness between the two is not necessary. As an example, in the power supply apparatus 100 of the first embodiment, only the DC / DC converter 120 and the electric load 20 are connected by the wire harness 30 as illustrated in FIG.

  The power supply device of the present invention can reduce the wire harness as an antenna that radiates noise, thereby reducing noise radiated from the wire harness. In addition, the wiring space of the wire harness can be reduced to reduce the size and weight of the power supply device, and the wiring work of the wire harness can be reduced.

  Note that the description in the present embodiment shows an example of the power supply device according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of the power supply device in this embodiment can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Battery 20 Electric load 30 Wire harness 100, 200, 300 Power supply device 110, 210, 310 Load power supply part (J / B)
111, 211, 311 Substrate 111a Metal core 120 Voltage converter (DC / DC converter)
121 Heat-generating component 122 Substrate 122a Metal core 130 Thermal coupling structure 212, 312 Relay 341 Temperature sensor 342 Determination unit 343 Control unit

Claims (5)

A power supply device used in a vehicle equipped with a battery and a plurality of electric loads,
A load power supply unit formed on a metal core substrate , connected to at least one of the electrical loads and supplying power from the battery;
A voltage conversion unit formed on a substrate separate from the metal core substrate, which stabilizes the voltage of power supplied to at least one of the electrical loads connected to the load power supply unit by stepping up or down ; With
Furthermore, it comprises a thermal coupling structure for causing heat transfer between the voltage conversion unit and the load power supply unit ,
The power supply apparatus according to claim 1, wherein the thermal coupling structure portion is a connector that thermally and electrically connects the metal core substrate and the substrate separate from the metal core substrate . The voltage conversion unit stabilizes the voltage of electric power supplied to the electric load within a predetermined voltage range when the voltage of the battery fluctuates below a predetermined value when the engine of the vehicle is started. The power supply device described in 1. The load power supply unit supplies power to the electrical load of the connection destination without operating the voltage conversion unit when a load current supplied to the electrical load of the connection destination is higher than a predetermined value. The power supply device according to claim 1 or 2 . A temperature sensor for measuring the temperature of the load power supply unit;
A determination unit that inputs the temperature measurement value from the temperature sensor and determines whether the voltage conversion unit operates or is limited; and
A control unit that performs control of operating or stopping the voltage conversion unit according to a determination result by the determination unit or operating the voltage conversion unit within a predetermined operating range is further provided. Or the power supply device of 2. A current sensor for measuring a load current of the load power supply unit;
A determination unit that inputs the current measurement value from the current sensor and determines whether the voltage conversion unit is operable or limited, and
A control unit that performs control of operating or stopping the voltage conversion unit according to a determination result by the determination unit or operating the voltage conversion unit within a predetermined operating range is further provided. Or the power supply device of 2.

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