JP2011120389A - Vehicle-mounted power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle-mounted power converter for achieving miniaturization of itself without impairing heat dissipation performance. <P>SOLUTION: A charger 210 is mounted on an upper surface 111 of a heat sink 110, and a DC-DC converter 310 is mounted on a lower surface 112 (rear surface) of the heat sink. With this configuration, the main amount of heat is supplied from the surface 111 of a charger side during charging (not running), and the main amount of heat is supplied from the surface 112 of the DC-DC converter side during running. Accordingly, the position of a heat source to be supplied to the heat sink 110 is changed depending on whether the vehicle is being charged or running, and the high amount of heat is not simultaneously supplied from both the surfaces. Thus, the amount of heat generation is reduced on one surface of the heat sink, so that a heat dissipation area can be sufficiently ensured in accordance with the reduction, and scale-up of the heat sink 110 can be avoided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle-mounted power conversion device, and is particularly suitable for use in downsizing the device without impairing the heat dissipation performance of the vehicle-mounted power conversion device.

  In recent years, in-vehicle devices (power windows, power steering, fuel pumps, lighting devices, audio, etc.) of automobiles are each provided with an ECU (Electric Control Unit), and electric control is performed according to a command signal of the ECU. Yes. Such in-vehicle devices (motors, illumination lamps, speakers, etc.) are supplied with electric power from a sub-battery mounted on an automobile, whereby each is appropriately controlled.

  Further, HEVs (Hybrid Electric Vehicles) that appropriately select the system of the electric motor and the internal combustion engine and give power to the drive wheels have been put into practical use. Furthermore, along with advances in technological development related to in-vehicle batteries, long-distance running with battery power becomes possible, and in response, HEV (Hybrid Electric Vehicle) equipped with a plug-in charging mechanism will be commercialized. It is. In addition, an EV (Electric Vehicle) has been introduced in which the internal combustion engine is excluded from the configuration of the vehicle and the vehicle is driven only by the electric motor. Hereinafter, plug-in HEVs and EVs are referred to as plug-in electric vehicles. On the other hand, when they are referred to as vehicles, internal-combustion engine vehicles (vehicles that generate driving force only by the engine) and HEVs (regardless of the charging method) and It refers to all EV drive system vehicles.

  The plug-in electric vehicle includes a main battery that supplies electric power to the wheel driving electric motor and a sub-battery that is provided to drive the in-vehicle device. Of these, the main battery is connected to an in-vehicle charger that generates charging power for high voltage. When commercial power and a command from the host ECU are given to the in-vehicle charger, the main battery is converted from the commercial power. The main battery is charged with the charging power. On the other hand, the sub-battery is connected to a DC-DC converter that generates charging power for low voltage. When a command from an ECU provided in the sub-battery is given to the DC-DC converter, the sub-battery is output from the DC-C converter. The sub battery is charged by the charged power.

  In both the in-vehicle charger and the DC-DC converter, components such as transistors generate heat, so that the generated heat is dissipated through a heat sink.

  For example, Japanese Patent No. 3468424 (Patent Document 1) introduces an apparatus in which heat-generating circuit elements are mounted on both surfaces of a heat sink. Such a device has a main battery that supplies a high power of several hundred volts to the traveling motor, an inverter circuit that converts the strong power from the main battery into alternating current power, and drives the traveling motor, and charges the main battery. The battery pack includes a charger, a sub-battery that supplies weak power of about 12 V to the in-vehicle device, and a DC-DC converter that converts power from the main battery and charges the sub-battery. Such a gazette shows that the power transistors of the inverter circuit are appropriately arranged on both sides of the heat sink, and that the DC-DC converter is mounted on one side of the heat sink together with the power transistor. Further, the description of the publication suggests that a charger is mounted on the heat sink.

  Japanese Patent No. 3166423 (Patent Document 2) introduces a cross-sectional structure of a heat sink. The heat sink has a two-piece structure in which an inner fin is formed on a bottom plate and an upper heat sink structure and a lower heat sink structure face each other. In the heat sink, when both structures are combined, a refrigerant flow path is formed by the inner fin and the bottom plate of the heat sink. Also, in this publication, as a conventional technique, a heat sink in which both inner fins have the same arrangement pitch and the tips of the inner fins are in contact with each other is introduced. Furthermore, as an embodiment of the invention, a heat sink in which the arrangement pitch of both inner fins is slid by a half pitch and the bottom plate is brought into contact with the tip of the inner fin is introduced.

Japanese Patent No. 3468424 Japanese Patent No. 3166423

  However, in the technology according to Patent Document 1, when the plug-in electric vehicle is run, the output power of both the inverter circuit and the DC-DC converter may be controlled at nearly 100%. It is necessary to have heat dissipation performance that can dissipate the maximum amount of heat at the same time, and the technology that generates heat simultaneously on both sides (front and back) of the heat sink will lead to an increase in the size of the heat sink in order to secure a heat dissipation area. Problems arise.

  Further, when a device without an inverter circuit is configured, it is conceivable to mount both a charger and a DC-DC converter on one surface of the heat sink. In such a case, although the space is secured on the other surface (back surface) of the heat sink and the heat radiation area is secured, the circuit device is concentrated on the one surface, which also leads to an increase in the size of the heat sink.

  Furthermore, if both the charger and DC-DC converter are mounted on one side of the heat sink, and the power transistor of the inverter circuit is placed in the free space on the other side (back side), the free space in the heat sink is effectively utilized. However, since the DC-DC converter and the inverter circuit may be simultaneously driven during traveling, as a result, heat is simultaneously supplied from both sides of the heat sink. The problem that it will be converted into a problem arises.

  Further, in the prior art described in Patent Document 2, as shown in FIG. 9, when the machining accuracy by machining is poor, or when thermal expansion is biased, the total length (Hf1 + Hf2) of the abutting inner fin is If it becomes longer than the total length (Hw1 + Hw2) of the side wall of the heat sink, a gap S is formed between the contact surfaces Sf of the side wall. In this case, the flow rate of the refrigerant passing through the ventilation path is reduced, so the heat dissipation effect of the heat sink is reduced. Problems occur. Further, even in the embodiment described in Patent Document 2, if a problem occurs in the dimensions of the side wall and the inner fin of the heat sink, the heat dissipation effect of the heat sink is reduced as before.

  On the other hand, regarding the technique of Patent Document 2, if the inner fin is shortened and a clearance is provided around the tip of the fin, the airtightness at the contact surface Sf of the side wall is ensured. It is possible to avoid the decrease. However, since the heat sink made into the two-piece structure has no contact surface via the inner fin, the heat transfer effect between the structures is reduced. Here, when the heat generation amounts of the two power conversion devices are different, the heat amount is transferred to the portion where the temperature gradient in the heat sink is in an equilibrium state. Therefore, depending on the shape of the heat sink structure, the contact between both heat sink structures Heat is transferred across the surface. In this case, if a clearance is provided around the tip of the inner fin, there is a problem that the contact area between both heat sink structures is reduced and the effective heat dissipation action is hindered. In addition, such a heat sink is not mentioned at all in the same publication (Patent Document 2) where a preferred form on the contact surface other than the inner fin should be studied.

  In view of the above problems, an object of the present invention is to provide a vehicle-mounted power conversion device that can realize downsizing of the device without impairing heat dissipation performance.

  In order to solve the above problems, the present invention has the following configuration of an in-vehicle power converter. That is, a heat sink, a charger that is mounted on one surface of the heat sink and converts the commercial power to charge the main battery, and is mounted on the other surface symmetrically provided on the one surface And a DC-DC converter that converts the output power of the main battery to charge the sub-battery.

  Moreover, in this invention, it is good also as a structure of the following vehicle-mounted power converter devices. That is, a heat sink, a charger that is mounted on one surface of the heat sink and that charges the main battery, and a battery that is mounted symmetrically on the one surface. A DC-DC converter that converts the output power of the main battery to supply power to the in-vehicle device is used.

  Preferably, the heat sink has a side wall and an inner fin, and a refrigerant flow path is formed by the side wall and the inner fin.

  Preferably, the heat sink includes a first structure portion including the one surface and a second structure portion including the other surface.

  Preferably, the inner fin is formed with a clearance around the inner fin, and the side wall is formed by direct contact between a part of the first structure part and a part of the second structure part. And

  Preferably, the inner fin of one structure portion of the inner fins has a plate thickness thinner than the gap between the inner fins of the other structure portion facing each other, and the cross section of the inner fin of the one structure portion is the inner fin Suppose that it arrange | positions in the range of the gap | interval of mutual.

  Preferably, the heat sink further includes a middle pillar portion formed in an inner region surrounded by the side wall, and a refrigerant flow path is formed by the side wall, the inner fin, and the middle pillar portion. To do.

  Preferably, the heat sink includes a first structure portion including the one surface and a second structure portion including the other surface, and a middle pillar portion in which a part of both structure portions is in direct contact with each other. The middle pillar portion is arranged between both the side walls.

  According to the in-vehicle power converter according to the present invention, the charger is mounted on one surface of the heat sink, and the DC-DC converter is mounted on the other surface (back surface) of the heat sink. The main amount of heat is supplied from the surface on the charger side, and the main amount of heat is supplied from the DC-DC converter side during traveling. Therefore, the position of the heat source supplied to the heat sink changes depending on whether it is charging or traveling, and a high amount of heat is not supplied from both sides at the same time, so the amount of heat generated on one side of the heat sink decreases, and heat is released accordingly. A sufficient area can be secured, and an increase in the size of the heat sink can be avoided.

  In addition, in the case where only the charger and the DC-DC converter are configured without mounting the inverter circuit, the charger and the DC-DC converter are distributed to each surface of the heat sink, so that the heat sink can be reduced in size. Thereby, size reduction of the vehicle-mounted power converter is realized.

  Furthermore, by adopting various structures that secure the heat radiation area of the heat sink, the heat sink can be further miniaturized and the in-vehicle power converter can be miniaturized while receiving the benefits of the above-described effects.

The figure which shows the circuit structure of the vehicle-mounted power converter device which concerns on embodiment. The figure which shows the circuit structure of the other vehicle-mounted power converter device which concerns on embodiment. The figure which shows the structure of the vehicle-mounted power converter device which concerns on embodiment. The figure which shows the internal structure of the vehicle-mounted power converter device which concerns on embodiment. The figure which shows the thermal radiation path | route of the vehicle-mounted power converter device which concerns on embodiment. The figure which shows the structure of the vehicle-mounted power converter device which concerns on Example 1. FIG. The figure which shows the distribution path cross section of the heat sink in the vehicle-mounted power converter device which concerns on Example 2. FIG. The figure which shows the distribution path cross section of a heat sink in case the tolerance of an inner fin is remarkable. The figure which shows the distribution path cross section of the heat sink in the vehicle-mounted power converter device which concerns on Example 3. FIG. The figure which shows the thermal radiation path | route in the heat sink of the vehicle-mounted power converter device which concerns on Example 3. FIG. The figure which shows the thermal radiation path | route in the heat sink of the vehicle-mounted power converter device which concerns on Example 3. FIG. The figure which shows the distribution path cross section of the heat sink in the vehicle-mounted power converter device which concerns on Example 4. FIG. The figure which shows the distribution path cross section of the heat sink in the vehicle-mounted power converter device which concerns on another example. The figure which shows the structure of the vehicle-mounted power converter device which concerns on Example 5. FIG. The figure which shows the distribution path cross section of the heat sink in the vehicle-mounted power converter device which concerns on Example 5. FIG. The figure which shows the distribution path cross section of the heat sink in the vehicle-mounted power converter device which concerns on another example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a circuit configuration of a power supply system in a plug-in electric vehicle (plug-in HEV, EV). In the drawing, a commercial power source and an external plug, which are externally configured, are shown for convenience. The commercial power supply Alt distributes commercial power, and the household power supply distributes 100 to 200 V (50 kHz / 60 kHz) from the power company. The external plug Pga is connected to the commercial power supply Alt and applies the commercial power described above.

  As shown in the figure, the power supply system C includes a vehicle-side plug Pgb, a charger 210, a main battery Vbm, a DC-DC converter 310, a sub-battery Vbs, in-vehicle devices L1, L2,..., And each ECU (Electric Control Unit). And are appropriately wired by power supply lines La and Lb and signal lines Lp and Lq.

  The vehicle-side plug Pgb is provided in the body portion of the plug-in electric vehicle, and is connected to the external plug Pga when charging the main battery Vbm.

  The charger 210 includes a first control circuit 213 and a first power element circuit unit 204, and receives commercial power from the vehicle-side plug Pgb. When the charger 210 receives the command signal SG1, an internal circuit operates in accordance with the signal to convert commercial power into charging power of several hundred volts. Such charging power is applied to the power supply lines La and Lb at the subsequent stage to charge the main battery Vbm.

  The main battery Vbm is charged by the charger 210 and supplies power of, for example, DC 200V.

  The DC-DC converter 310 includes a second control circuit 313 and a second power element circuit unit 304, and receives high-voltage power from the main battery Vbm. When the DC-DC converter 310 receives the command signal SG2, an internal circuit operates in accordance with the signal, and converts the high voltage power from the main battery Vbm to weak power of about 12V to 14V. Such weak electric power is applied to the power supply lines La and Lb at the subsequent stage to charge the sub battery Vbs.

  The sub-battery Vbs is charged by the weak electric power from the DC-DC converter 310 and supplies, for example, DC 12V power.

  Each of the in-vehicle devices L1, L2,... Is connected in parallel to the sub battery Vbs and is driven by weak electric power of about 12V to 14V received from the sub battery Vbs. Such in-vehicle devices refer to devices that are electrically controlled, such as power windows, power steering, fuel pumps, and lighting devices.

  The host ECU 30 is an information processing apparatus including a microcomputer, a memory circuit, and the like. The host ECU 30 centrally manages various types of information in the vehicle, and based on the information, in-vehicle devices (charger 210, wiper, fuel motor, illumination lamp) , Audio, etc.) are directly or indirectly controlled. In the control of the charger 210, the host ECU 30 receives necessary information such as voltage value information of the main battery Vbm, and based on the information, performs an arithmetic processing on the command signal SG1 to be transmitted to the charger 210. In some cases, control signals for the in-vehicle devices L1, L2,.

  The sub-battery ECU 40 manages the supply voltage of the sub-battery Vbs. When the supply voltage decreases, the sub-battery ECU 40 generates and outputs a command signal SG2, and requests the charging operation of the DC-DC converter 310. Then, when the supply voltage of the sub battery Vbs returns to a normal value, the output of the command signal SG2 is stopped and the operation of the DC-DC converter 310 is stopped.

  The power supply system C configured as described above operates as follows. That is, during the charging operation, when the external plug Pga is connected to the vehicle-side plug Pgb, the command signal SG1 is output from the host ECU 30, and the charger 110 drives the internal circuit to count the input commercial power. Convert to 100 volts DC power. On the other hand, since the plug-in type electric vehicle is stopped, the DC-DC converter 310 hardly receives an operation command to the in-vehicle device.

  On the other hand, when the driver runs the plug-in electric vehicle, the sub-battery ECU 40 outputs a command signal SG2 according to consumption of the sub-battery Vbs, and the DC-DC converter 310 is driven. On the other hand, since the charger 210 is running, the external plug Pga is removed from the vehicle-side plug Pgb, and the command signal SG1 for prompting the charging operation is not received from the host ECU 30.

  The power supply system according to the present embodiment may be configured as shown in FIG. That is, the sub battery Vbs may be omitted from the power supply system described above, and power may be directly supplied to the in-vehicle device.

  In this case, the DC-DC converter 310 receives the command signal SG2 from the in-vehicle device, and appropriately outputs weak electric power based on the signal.

  3 and 4 show the configuration of the above-described in-vehicle power converter. As illustrated, the in-vehicle power converter 1 includes a heat sink 110, a charger 210, and a DC-DC converter 310.

  The heat sink 110 is made of a material having high thermal conductivity such as an aluminum plate or a copper plate, and the width or length of the plate body is set so as to have an appropriate heat radiation area. Further, fins or the like may be provided in order to enhance the heat dissipation effect. Hereinafter, one surface 111 of the heat sink is referred to as an upper surface, and the other surface 112 provided symmetrically on the upper surface 111 is referred to as a lower surface 112.

  As shown in FIG. 3, the charger 210 includes a case 211, a first control circuit 213, and a power element circuit unit 204. The charger 210 is mounted on the upper surface 111 of the heat sink 110, and contains a heat-generating element such as a power transistor 204d, a diode, a capacitor, a coil transformer (not shown), and a filter circuit, a rectifier bridge, and a PFC circuit. A buck-boost power conversion circuit or the like is appropriately configured.

  The case 211 accommodates at least the first control circuit 213 and the power element circuit unit 204 in order to realize the above-described circuit. A heat radiating plate 205 having high thermal conductivity is exposed on the upper surface 111 of the case 211, and the heat radiating plate 205 is in direct contact with the upper surface 111 of the heat sink. Further, the structure of the case 211 is made of an insulating resin material, and a connector part 212 having connector terminals is formed. As shown in FIG. 3, the connector terminal 202a includes a signal terminal 202a1, an input terminal 202a2, and an output terminal 202a3. A command signal SG1 is applied to the signal terminal 202a1, and a battery or a power source is applied to the input terminal 202a2. From the output terminal 202a3, and the power converted by the charger is output from the output terminal 202a3.

  The first control circuit 213 includes a control IC 203a and other necessary electrical elements. Further, printed wiring is provided on the substrate, and the signal terminal 202a1 is solder-connected to the printed wiring. With this configuration, when the command signal SG1 is input to the signal terminal 202a1, the first control circuit 213 transmits the command signal SG1 to the control IC 203a via the printed wiring. At this time, the control IC 203a converts the command signal SG1 into an appropriate form, and then outputs a signal obtained by such processing to drive and control the power transistor 204d.

  As shown in the figure, the power element circuit unit 204 has an insulating substrate 204a bonded to a heat radiating plate 205 via a heat radiating resin. A printed wiring 204b is formed on the insulating substrate 204a, and the printed wiring 204b has a power transistor 204d mounted thereon via a solder layer 204c. In addition, as described above, various functional circuits other than the power element circuit unit 204 are accommodated in the case 211, and these circuits act to convert the input power to a desired power. Convert it. That is, when the first control circuit 213 operates in response to the command signal SG1, each functional circuit including the power element circuit unit 204 operates, whereby input power is appropriately converted and a desired value is obtained. Output power.

  In the charger 210 having such a configuration, when the command signal SG1 is applied to the signal terminal 202a1, the first control circuit 213 drives the power transistor 204d according to the signal. At this time, the input power is converted into output power by the power element circuit unit 204 and other functional circuits, and the output power is output from the output terminal 202a3.

  Here, when the power transistor 204d and other heat generating elements are driven, heat is generated in the elements. The amount of heat is guided to the heat sink 110 through the heat radiating plate 205, and heat exchange is performed at an appropriate place on the heat sink 110. That is, since the heat generated from the heat generating element is transmitted to the outside, the heat generating element is free from damage to the element.

  The DC-DC converter 300 includes a case 311, a second control circuit 313, and a power element circuit unit 304, and generates and outputs weak electric power of about 14 V to 12 V in order to supply power to the sub-battery or the in-vehicle device. . And since these structures are general structures like the charger 210, the description thereof will be omitted.

  FIG. 5 shows a transmission path of the heat amounts Ht1 and Ht2 transmitted to the heat sink. However, for the sake of convenience, the illustration of the components other than the power transistor in the configurations of both power conversion units is omitted. Further, it is assumed that a temperature gradient is generated from the transistor toward the end of the heat sink inside the heat sink 110.

  FIG. 5A shows a scene in which a commercial power source is connected to an in-vehicle connector (not shown) and the charger 210 is driven. In this case, since the power transistor 204d is driven, heat is generated in the transistor 204d, and the heat is diffused and guided to the heat sink 110, and is transmitted to the low temperature side according to the temperature gradient inside the heat sink. Heat exchange. On the other hand, the plug-in electric vehicle is not running because it is being charged, and on-vehicle devices (power window, power steering, fuel pump, lighting equipment, etc.) mounted on the plug-in electric vehicle are hardly operated. . For this reason, almost no amount of heat is generated from the transistor 304d, so that almost no heat is supplied to the heat sink.

  On the other hand, when the charging of the main battery is completed and the travel of the plug-in electric vehicle is started, the charger 210 stops and the amount of heat from the power transistor 204d decreases as shown in FIG. Then, since the in-vehicle device is driven according to the driver's operation or the command from the control unit of the plug-in electric vehicle, the electric power stored in the sub-battery is reduced according to this operation. In response to this, the sub-battery ECU 40 outputs a command signal SG2 to drive the DC-DC converter 310 so as to charge the sub-battery Vbs. In such a case, since the power transistor 304d is driven, a heat amount is generated in the transistor 304d, and the heat amount is heat-exchanged at a low temperature via the heat sink 110. In the present embodiment, the sub-battery ECU issues an operation command for the DC-DC converter 310. However, the present invention is not limited to this, and the output voltage (or the divided voltage value) of the sub-battery Vbs is the control circuit 313. The control circuit 313 may drive the DC-DC converter in accordance with an input signal from the sub-battery.

  As described above, according to the in-vehicle power conversion device 1 according to the present embodiment, the charger 210 is mounted on the upper surface 111 of the heat sink 110, and the DC-DC converter 310 is mounted on the lower surface 112 (back surface) of the heat sink. Therefore, the main amount of heat is supplied from the surface 111 on the charger side during charging (during non-traveling), and the main amount of heat is supplied from the surface 112 on the DC-DC converter side during traveling. Therefore, the position of the heat source supplied to the heat sink 110 changes depending on whether it is charging or traveling, and a high amount of heat is not supplied simultaneously from both sides, so the amount of heat generated on one side of the heat sink decreases, and accordingly A sufficient heat radiation area is ensured, and an increase in size of the heat sink 110 can be avoided.

  In addition, when only the charger 210 and the DC-DC converter 310 are configured without mounting an inverter circuit, the charger 210 and the DC-DC converter 310 are distributed to each surface of the heat sink. As a result, downsizing of the in-vehicle power conversion device 1 is realized.

  Furthermore, in this embodiment, when an inverter circuit is mounted on the heat sink, it is preferable that the power transistor constituting the inverter circuit is mounted on the surface on the DC-DC converter side. That is, since the inverter circuit and the DC-DC converter 310 are circuits that are driven during traveling, with this configuration, the heat sink 110 has one of the surfaces on which the heat source is mounted depending on whether it is traveling or charging. The heat radiation area is sufficiently secured on the other surface.

  In the present embodiment, even if the power transistor of the inverter circuit is mounted on the surface on which the charger 210 is mounted, if the heat source during traveling and the heat source during charging are appropriately distributed, The effect is achieved within a certain range.

  In the present embodiment, a plug-in electric vehicle in which a charger is mounted on the vehicle is described. However, the in-vehicle power converter described in the claims is not limited to this technology. For example, the in-vehicle power converter described in the claims is also applied to a power supply system in which a charger is omitted from an electric vehicle or a hybrid vehicle, and the vehicle is charged by a high-speed charger provided as an external facility. obtain. In this case, a relay device composed of a power transistor may be provided between the in-vehicle connector and the main battery, and the DC power supplied from the high-speed charger is DC-DC converted to a preferable value. There may be a case where a DC-DC conversion circuit for adjusting the charging voltage is provided. In these cases, the relay device or the DC-DC conversion circuit is mounted on one surface of the heat sink, and the DC-DC converter 310 is mounted on the other surface of the heat sink, so that the vehicle-mounted power conversion device according to the present modification is provided. Then, the same effects as described above are exhibited.

  Hereinafter, various structures for securing the heat radiation area of the heat sink will be described by way of examples. Since these examples have the configuration according to the embodiment, the heat sink can be further downsized and the in-vehicle power converter can be downsized while receiving the benefits of the above-described effects.

  FIG. 6 shows a new power conversion device in which the heat sink described above is modified. In the power conversion device 3, the heat sink is replaced with one having an inner fin. Since the other configuration is the same as the configuration according to the embodiment, the same reference numerals are given and the description thereof is omitted.

  As shown in the drawing, the heat sink 120 has side walls 123 and inner fins 124 formed therein. The side wall 123 has a lateral airtightness so that the refrigerant does not flow outside from the refrigerant inflow side IN to the outflow side OUT. The inner fins 124 are formed of plate-like bodies having a predetermined thickness along the direction of passage of the refrigerant, and a plurality of inner fins 124 are arranged at an appropriate pitch. That is, the refrigerant flow path is formed by the side wall 123 and the inner fin 124. As described above, since a plurality of inner fins are formed, a sufficient heat radiation area is ensured inside the heat sink, and heat exchange is effectively performed.

  Even in the heat sink according to the present embodiment, the heat sink is formed of a material having good thermal conductivity such as aluminum, and the manufacturing method thereof is manufactured by casting or machining. However, in the case of casting, there is a possibility that the refrigerant leaks from the porous nest. Therefore, in the case where the refrigerant is a liquid fluid, it is preferably manufactured from a rolling material or the like.

  As described above, according to the power conversion device 3 according to the present embodiment, since the plurality of inner fins 124 are formed inside the heat sink 120, a sufficient heat radiation area is ensured, and heat exchange with the refrigerant is effectively performed.

  Further, since the airtightness of the heat sink 120 is maintained, the fluid used as the refrigerant forcibly passes through the refrigerant distribution path without leaking to the outside of the heat sink even when the flow rate is increased. Heat exchange in the distribution path is effectively performed, and thus the heat sink 120 can be downsized.

  However, since the technique of the first embodiment has a one-piece structure, it is very difficult to process the heat sink. Therefore, in this embodiment, a manufacturing method and a structure of a heat sink that solves such a problem will be introduced. Note that FIG. 7 shows a state in which the refrigerant cross section is observed.

  As shown in FIG. 7A, the heat sink 130 according to the present embodiment includes a first structure portion 130 a that includes one surface 131 and a second structure portion 130 b that includes the other surface 132. That is, a two-piece structure including a structure for mounting the charger 210 and a structure for mounting the DC-DC converter 310 is adopted.

  As for the 1st structure part 130a, the side wall formation body 133a is formed in the both ends of the baseplate part 136a at substantially right angle. The side wall forming body 133 a has a predetermined plate thickness and forms a part of the side wall 133. In the first structure portion 130a, a plurality of fin forming bodies 134a are formed substantially in parallel between both side wall forming bodies 133a. Further, in the present embodiment, the processing is performed so that the height dimension of the end portion of the side wall forming body 133a substantially matches the height dimension of the end portion of the fin forming body 134a.

  The second structure portion 130b includes a bottom plate portion 136b, a side wall forming body 133b, and a fin forming body 134b, and the shape thereof is substantially the same as the configuration of the first structure portion 130a.

  Since the first structure portion 130a and the second structure portion 130b divide the inside of the ventilation path, the fin forming body appears on the surface of the structure portion and can be manufactured by a machine tool. In addition, processing from a plate material can be performed by a machine tool, and the problems caused by the above-described cast product are also solved.

  FIG. 7B shows a state in which the first structure portion 130a and the second structure portion 130b are assembled. As shown in the drawing, the heat sink 130 is in a state where both the side wall forming body and the fin forming body are in contact with each other and are in direct contact with each other, and the inner fin 134 and the side wall 133 are formed by both the forming bodies. The charger 210 is mounted on one surface 131 formed in the first structure portion 130a, and the DC-DC converter 130 is mounted on the other surface 132 formed in the second structure portion 130b. .

  In the present embodiment, both structural parts are sealed and welded, thereby preventing the refrigerant from flowing out. However, as long as the seals of both the structural portions are ensured, the sealing portion may be provided by providing an O-ring at the contact portion without being limited to such a configuration.

  As described above, according to the power conversion device 4 according to the present embodiment, since the refrigerant flow path in the heat sink 130 is divided between the upper and lower mounting surfaces, it is possible to machine the internal structure constituting the inner fin and the like. Become.

  However, in the power conversion device 4 according to the second embodiment, the contact portions of the fin forming bodies 134a and 134b and the side wall forming bodies 133a and 133b are formed by machining such as a cutting machine. Will occur. When the pitches of both inner fins are aligned, if the sum of the height dimensions of the side wall forming bodies 133a and 133b is longer than the sum of the height dimensions of the fin forming bodies 134a and 134b, one side wall forming body 133a is formed. As shown in FIG. 8, a gap S is formed in the contact surface Sf between the other side wall forming body 133a and depending on the degree, it is difficult to perform welding or other sealing contact.

  Therefore, in the heat sink according to the present embodiment, when the pitches of both inner fins are aligned with each other, the height of the inner fins 144a and 144b formed in both structural portions is set to the height of the side wall forming bodies 143a and 143b. As shown in FIG. 9A, it is preferable that a vertical clearance be formed around the inner fin, particularly at the tips of the inner fins 143a and 143b. In this embodiment, the structure parts are in direct contact with each other by the side wall structure.

  As a result, as shown in FIG. 9B, when the first structure portion 140a and the second structure portion 140b are joined, an appropriate clearance is formed at the tips of both inner fins in the refrigerant flow path. The side wall forming body 143a and the side wall forming body 143b come into contact with each other reliably. That is, according to the power conversion device of the present embodiment, since the vertical clearance is provided at the tip of the inner fin, even if the inner fin has a poor dimensional tolerance, the side wall forming bodies reliably come into contact with each other. The sealing property at the contact surface is ensured.

  FIG. 10 shows a case where the operation of the charger 210 is remarkable. In such a case, the power transistor 204d and the like housed in the charger 210 are driven, and the amount of heat is transmitted from these and other exothermic elements toward the first structure portion 140a. Here, since heat exchange is performed at any time in the refrigerant flow path, a temperature gradient is generated toward both the inner fins 144a and 144b when the vicinity of the power transistor 204d is used as a reference. Therefore, a part of the amount of heat is guided to each of the inner fins 144a on the first structure portion side, and heat exchange is performed with the refrigerant. Further, the remaining amount of heat guided to the first structure part is transmitted to the second structure part via the contact surfaces Sf of both structure parts because the side wall forming bodies 143a and 143b are in direct contact with each other. Is done. Thereafter, the amount of heat transferred to the second structure part is guided to the inner fin 144b provided in the second structure part, and heat is exchanged with the refrigerant also here.

  On the other hand, when the plug-in electric vehicle runs and the position of the heat source is reversed, the temperature gradient in the heat sink structure is reversed in such a scene, and the amount of heat generated in the power transistor 304d is partially as shown in FIG. It is led to each of the inner fins 144b on the second structure part side and exchanges heat with the refrigerant. Further, the remaining amount of heat is transmitted to the first structure portion via the contact surface Sf.

  That is, in the heat sink 140 according to the present embodiment, heat transfer between the structural portions is smoothly performed by the contact surface Sf on the side wall 143, and the heat dissipation function is performed using both the first structural portion 140a and the second structural portion 140b. Is effectively demonstrated. As shown in the figure, heat exchange with the refrigerant is performed not only on the surface of the inner fin, but also appropriately by the bottom plate 146 or the side wall structure.

  As described above, according to the power conversion device 5 according to the present embodiment, the amount of heat of one structure portion is smoothly transferred to the other structure portion by the contact surface Sf on the side wall. In such a case, the temperature gradient changes reciprocally inside the heat sink, and accordingly, the amount of heat is guided to the low temperature side, and the heat radiation action is effectively performed in both structures. Thereby, the heat sink 140 can be downsized.

  However, in the heat sink of Example 3, since it arrange | positions so that the front-end | tip of both inner fins may oppose, a fixed process precision is requested | required in order to form a clearance reliably. Therefore, in order to alleviate the requirement for processing accuracy to some extent, the heat sink 150 shown in FIG. Hereinafter, the direction perpendicular to the cross section of the inner fin will be described as “the inner fin arrangement direction F” or “the arrangement direction F”, and FIGS. 12 and 13 will be described.

  As shown in FIG. 12A, the plate thickness t1 of the inner fin 154a of the first structure portion 150a is thinner than the gap B2 between adjacent inner fins of the inner fins 154b of the second structure portion 150b. The plate thickness t2 of the inner fin 154b of the second structure portion 150b is thinner than the gap B1 between the adjacent inner fins of the inner fin 154a of the first structure portion 150a. Further, when both structural parts are combined, the cross section of the inner fin 154a is disposed within the range of the gap B2 between the inner fins in the second structural part 150b, and the cross section of the inner fin 154b is both structural parts. Are combined within the range of the gap B1 between the inner fins in the first structure portion 150a. More preferably, the cross section of the inner fin of the first structure portion is arranged by being slid by a half pitch with respect to the arrangement direction of the inner fins of the second structure portion.

  Thereby, as shown in FIG. 12B, when the first structure portion 150a and the second structure portion 150b are combined, the tips of the inner fins do not face each other, and the tips of the inner fins do not face each other. Thus, a sufficient clearance is formed. In this case, the height of the inner fin 154a may exceed the height dimension of the side wall structure 153a. The same applies to the inner fin of the second structure portion 150b.

  As described above, according to the power conversion device 6 according to the present embodiment, the tips of both inner fins are slid appropriately in the fin arrangement direction F, so that both tips do not face each other. A sufficient clearance is provided around the tip of the inner fin. In addition, since the heat sink 150 is appropriately brought into contact with each other, both structural portions are reliably brought into contact with each other, and the sealing function of the contact portion and the effect of transmitting the unevenly distributed heat amount are exhibited.

  As shown in FIG. 13A, the total length of the inner fins may be shorter than the side wall structure 160a or 160b. In such a case, the clearance at the tip of the inner fin is more sufficiently secured.

  Further, as shown in FIG. 13B, the total length of the inner fin may be longer than that of the side wall structure 160a or 160b. The inner fin in the figure may be formed in a range where the tip does not contact the bottom plate 166a or 166b. In such a case, the heat radiation area can be increased without affecting the outer dimensions of the heat sink.

  FIG. 14 shows a power conversion device in which the heat sink of the second embodiment is further modified. In the power conversion device 9, the heat sink is replaced with one having a middle pillar portion 185. In addition, since it is the same as that of the structure shown in Example 1 about this other structure, suppose that the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in the figure, the heat sink 180 has a middle pillar portion 185 formed in an inner region surrounded by the side wall 183 and the bottom plate. In other words, the middle column portion 185 has substantially the same form as the side wall 183, and is formed between both side walls 183. Therefore, according to the heat sink 180 according to the present embodiment, the refrigerant flow path is formed by the side walls 183, the inner fins 184, the middle pillar portion 185, and the bottom plate, and in this embodiment, the flow path is formed by two paths. Will be.

  As described above, according to the power conversion device 9 according to the present embodiment, a heat amount transmission path is newly added by the middle column portion 185, and thereby, the uneven distribution of heat amount is immediately uniformed, and the heat dissipation effect is improved. Is planned. Therefore, in the power converter 9, even if the heat source is switched in a reciprocal manner, an effective heat exchange is performed without stagnation of the amount of heat generated accordingly.

  Moreover, it is preferable that the middle pillar part of a present Example is provided directly under heat dissipation elements, such as a power transistor. As a result, the amount of heat generated in the heat dissipating element shortens the heat transfer path to the opposing structural portion, and accordingly, heat exchange within the heat sink is more effectively performed.

  Note that the power conversion device 9 according to the present embodiment may be modified to obtain a power conversion device 10 as shown in FIG. More specifically, the heat sink 190 used in the present embodiment includes a first structure 190a including one surface 191 and a second structure 190b including the other surface 192. Further, both the structural portions 190a and 190b have a middle column portion 195 partially in direct contact. The middle pillar portion 195 includes middle pillar structures 195a and 195b of both structural portions, and these structures abut against each other. Thereby, not only the two heat transfer paths on the side wall 193 but also a new heat transfer path is formed.

  Further, the middle pillar portion 195 of the present embodiment is disposed between the side walls 193 on both sides. And since this middle pillar part 195 is arrange | positioned directly under a heat radiating element, the heat transfer effect | action is performed more smoothly.

  Further, as shown in the figure, since the upper and lower layers of the heat sink are divided into two pieces, it is easy to process the internal structure such as the inner fin.

  In the case of FIG. 15, the tips of the inner fins 194a and 194b are opposed to each other, but the layout of the inner fins is not limited to such a mode. For example, as shown in FIG. 16, the structure of the heat sink 190 may be a two-piece structure, and the arrangement of the inner fins may be shifted by a half pitch. In such a case, a heat transfer path is preferably ensured and a sufficient clearance is provided at the tip of the inner fin. And since the structure of a heat sink is correctly joined by this structure, the improvement of the thermal radiation effect is achieved with all the effects mentioned above.

  In the above-described embodiment, referring to the drawings, both heat sinks are shown to have the same height. However, such dimensions may be appropriately adjusted according to the amount of power or the amount of heat generated by a power converter such as a charger or a DC-DC converter to be mounted.

DESCRIPTION OF SYMBOLS 1 In-vehicle power converter 110 Heat sink 210 Charger 310 DC-DC converter

Claims (8)

  A heat sink, a charger mounted on one surface of the heat sink and charging a main battery, and mounted on the other surface symmetrically provided on the one surface, the main A vehicle-mounted power conversion device comprising: a DC-DC converter that converts output power of a battery to charge a sub-battery.   A heat sink, a charger mounted on one surface of the heat sink and charging a main battery, and mounted on the other surface symmetrically provided on the one surface, the main A vehicle-mounted power conversion device comprising: a DC-DC converter that converts output power of a battery to supply power to a vehicle-mounted device.   The in-vehicle power converter according to claim 1, wherein the heat sink includes a side wall and an inner fin, and a refrigerant flow path is formed by the side wall and the inner fin. .   The in-vehicle power converter according to claim 3, wherein the heat sink includes a first structure part including the one surface and a second structure part including the other surface. The inner fin has a clearance formed around the inner fin,
5. The in-vehicle power conversion device according to claim 3, wherein the side wall is formed by direct contact between a part of the first structure part and a part of the second structure part. . The inner fin of one structure portion of the inner fins has a plate thickness thinner than the gap between the inner fins of the other structure portion facing each other,
The in-vehicle power conversion device according to claim 3, wherein a cross section of the inner fin of the one structural portion is disposed within a gap between the inner fins.   The heat sink further includes a middle column portion formed in an inner region surrounded by the side wall, and a refrigerant flow path is formed by the side wall, the inner fin, and the middle column portion. The in-vehicle power converter according to any one of claims 3 to 6. The heat sink includes a first structure portion including the one surface and a second structure portion including the other surface, and includes a middle pillar portion in which a part of both structure portions are in direct contact with each other. ,
The in-vehicle power conversion device according to claim 7, wherein the middle column portion is disposed between both the side walls.

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