JP2005323455A - Drive system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact drive system for a vehicle which can cool electric equipment favorably. <P>SOLUTION: A drive shaft 106 coupled with a front wheel 108 is driven by a driving force from either an engine 100 or a motor generator 200. An inverter 300 which supplies the motor generator 200 with power is cooled by being supplied with a coolant such as cooling water or the like sent out via a pipe 304 from a water pump 302. A drive shaft 604 coupled with a rear wheel 606 is driven by a driving force from a rear motor generator 600. A rear inverter 500 for supplying the rear motor generator 600 with water is provided with a Peltier element 700. A rear inverter 500 is cooled by the Peltier effect of the Peltier element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle drive system, and more particularly, to a vehicle drive system equipped with an electric device cooled using a Peltier element.

  In recent years, as part of countermeasures for environmental problems, attention has been focused on hybrid vehicles that run with the assistance of the engine by the driving force from the motor or that run only by the driving force from the motor. Some such hybrid vehicles drive both front and rear wheels.

  Japanese Patent Laying-Open No. 2002-19482 (Patent Document 1) discloses a hybrid vehicle having front wheels driven by at least one of an engine and a motor generator and rear wheels driven by a rear motor generator. The hybrid vehicle described in Patent Document 1 is a vehicle in which a front wheel system is driven by a main drive device and a rear wheel system is driven by a sub drive device. The main drive device includes an engine and a motor generator. Torque output from the engine and motor generator is transmitted to the front wheels. The auxiliary drive device includes a rear motor generator that functions as a second prime mover, that is, a secondary prime mover. Torque output from the rear motor generator is transmitted to the rear wheels. A drive current supplied to the motor generator from a power storage device such as a battery and a generated current output from the motor generator to the power storage device are controlled by an inverter. The drive current supplied from the power storage device to the rear motor generator and the generated current output from the rear motor generator to the power storage device are controlled by the rear inverter.

According to the hybrid vehicle described in this publication, the front and rear wheels can be driven to drive the vehicle in a four-wheel running state.
JP 2002-19482 A

  Electrical devices such as inverters and rear inverters generate heat to control current. Therefore, it is necessary to cool the electric device that generates heat. For this reason, a cooling system for cooling the electric device must be mounted on the hybrid vehicle. In the hybrid vehicle, a motor and an electric device for motor control are mounted in addition to the engine. The mounting space of the vehicle is not enough even for a normal vehicle, and the mounting space of the hybrid vehicle is further limited. However, the above-mentioned publication does not describe anything about the configuration for cooling the electrical equipment.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a compact vehicle drive system that can cool an electric device well.

  A vehicle drive system according to a first aspect of the present invention is a vehicle drive system having at least a first axle and a second axle different from the first axle. This drive system is provided on the first rotating electrical machine side, not on the engine side, and controls the first rotating electrical machine, and is provided on the first rotating electrical machine that drives the first axle, the engine that drives the second axle, and the engine side. First electrical equipment. The first electric device is cooled using a Peltier element.

  According to the first invention, the first axle is driven by the rotating electrical machine, and the second axle is driven by the engine. The rotating electrical machine is controlled by an electric device. This electric device is cooled using a Peltier element. Thus, it is possible to configure a drive system that drives the first axle and the second axle and cools the electric equipment without providing a pipe for supplying the cooling medium. Therefore, even if the electrical device for controlling the rotating electrical machine is provided not on the engine side but on the first rotating electrical machine side, for example, a pipe connected to a water pump or a radiator provided in the engine room is connected from the engine room to the electrical device. Without using a large-scale cooling system that is provided, the first electric device can be cooled in a hybrid vehicle in which the mounting space is severely limited. As a result, it is possible to provide a compact vehicle drive system that can satisfactorily cool the electrical equipment.

  In addition to the configuration of the first invention, the vehicle drive system according to the second invention includes a second rotating electrical machine that drives the second axle in cooperation with the engine, and the first electric device side. Instead of the first electric device that controls the second rotating electrical machine and the refrigerant pump that is provided not on the first electric device side but on the engine side and supplies the cooling medium to the second electric device And further including. The second electric device is cooled by a cooling medium supplied by a refrigerant pump.

  According to the second invention, the second axle is driven by the second rotating electrical machine cooperating with the engine, and the second rotating electrical machine is controlled by the second electrical device. The second electric device is provided not on the first electric device side but on the engine side, and is cooled by a cooling medium supplied by a refrigerant pump that supplies the cooling medium to the second electric device. Accordingly, the second electric device can be cooled in the drive system in which the second axle is added to the engine and driven by the second rotating electrical machine. The second electric device is provided not on the first electric device side but on the engine side. Therefore, for example, even if a pipe connected to a water pump or a radiator provided in the engine room is connected to the second electric device, it is possible to prevent the total length of the pipe from becoming long. As a result, the second electric device can be cooled in a hybrid vehicle in which the mounting space is severely limited without using a large-scale cooling system.

  In the vehicle drive system according to the third invention, in addition to the configuration of the first or second invention, the second axle and the engine are provided in the front portion of the vehicle. The first axle and the first rotating electrical machine are provided at the rear of the vehicle.

  According to the third invention, in the vehicle in which the second axle and the engine are provided in the front part of the vehicle, and the first axle and the first rotating electrical machine are provided in the rear part of the vehicle, it is possible to satisfactorily cool the electrical equipment. It is possible to provide a compact vehicle drive system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
With reference to FIG. 1, a vehicle equipped with a drive system according to a first embodiment of the present invention will be described. This vehicle includes an engine 100, a motor generator 200, an inverter 300, a battery 400, a rear inverter 500, and a rear motor generator 600.

  Engine 100 burns a mixture of fuel and air to rotate a crankshaft (not shown) to generate driving force. The driving force generated by engine 100 is transmitted to at least one of CVT (Continuously Variable Transmission) 104 and motor generator 200 via power switching mechanism 102. The driving force transmitted to the CVT 104 is transmitted to the front wheel 108 via the drive shaft 106. As a result, the front wheel 108 is driven.

  Motor generator 200 is a three-phase AC rotating electric machine. The motor generator 200 is driven by the driving force of the engine 100 transmitted through the power switching mechanism 102 to generate power. Further, during regenerative braking of the vehicle, the motor generator 200 is driven by the front wheels 108 via the CVT 104 and the drive shaft 106 to generate electric power. Electric power generated by motor generator 200 is converted from AC power to DC power by inverter 300 and stored in battery 400.

  On the other hand, when the vehicle starts or accelerates, the electric power stored in battery 400 is supplied to motor generator 200 via inverter 300. As a result, the motor generator 200 generates a driving force. The driving force of the motor generator 200 is transmitted to the front wheels 108 via the power switching mechanism 102, the CVT 104, and the drive shaft 106 at the front of the vehicle. Thus, motor generator 200 causes the vehicle to travel or assists engine 100. The voltage may be adjusted by a converter to supply power to motor generator 200 or battery 400.

  The inverter 300 generates heat when converting electric power. Therefore, it is necessary to cool the inverter 300. The inverter 300 is cooled by being supplied with a cooling medium such as cooling water sent from the water pump 302 via the pipe 304. The cooling water is supplied to the motor generator 200 via the inverter 300, and then heat is exchanged with the air by the radiator 306 to be cooled. Water pump 302 may be driven by electric power or may be driven by the driving force of engine 100.

  Engine 100, power switching mechanism 102, CVT 104, motor generator 200, inverter 300, water pump 302, pipe 304, and radiator 306 are provided in the engine room at the front of the vehicle. Therefore, inverter 300 is provided not on the rear inverter 500 side but on the engine 100 side.

  The battery 400 is an assembled battery configured by connecting a plurality of battery modules in which a plurality of battery cells are integrated in series. Note that a capacitor may be used instead of the battery 400.

  The electric power stored in the battery 400 is stepped down by the DC / DC converter 402 and then supplied to the auxiliary battery 404. The electric power stored in the auxiliary battery 404 is supplied to the auxiliary equipment of the vehicle. The battery 400 is provided, for example, below the rear seat of the vehicle or inside the trunk room at the rear of the vehicle.

  Rear inverter 500 converts electric power stored in battery 400 from direct current power to alternating current power, and supplies it to rear motor generator 600. On the other hand, during regenerative braking of the vehicle, AC power generated by rear motor generator 600 is converted to DC power and supplied to battery 400. The rear inverter 500 is provided, for example, below the rear seat of the vehicle or inside the trunk room at the rear of the vehicle. Therefore, rear inverter 500 is provided not on engine 100 side but on rear motor generator 600 side.

  The rear inverter 500 generates heat when converting electric power. Therefore, the rear inverter 500 needs to be cooled. The rear inverter 500 is provided with a Peltier element 700. The rear inverter 500 is cooled by the Peltier effect of the Peltier element. In addition, you may make it cool electric apparatuses other than the rear inverter 500, such as a converter, for example.

  Rear motor generator 600 is a three-phase AC rotating electric machine. Rear motor generator 600 is provided at the rear of the vehicle so as to be coupled to drive shaft 604 at the rear of the vehicle. When starting or accelerating the vehicle, the rear motor generator 600 is supplied with a DC current supplied from the battery 400 after being converted into an AC current by the rear inverter 500. As a result, rear motor generator 600 generates a driving force. The driving force of rear motor generator 600 is transmitted to rear wheel 606 via drive shaft 604. As a result, the vehicle travels by driving the rear wheels 606.

  On the other hand, at the time of regenerative braking of the vehicle, the rear motor generator 600 is driven by the rear wheels 606 via the drive shaft 604 to generate electric power. The electric power generated by rear motor generator 600 is converted from AC power to DC power by rear inverter 500 and stored in battery 400. It is noted that power may be supplied to rear motor generator 600 and battery 400 by adjusting the voltage with a converter.

  The Peltier element 700 is supplied with electric power stored in the auxiliary battery 404. When electric power is supplied, the Peltier element moves heat on the joint surface side with the rear inverter 500 to a surface opposite to the joint surface. Thereby, rear inverter 500 is cooled.

  The inverter 300 and the rear inverter 500 will be further described with reference to FIG. A capacitor 800 is connected in parallel with the inverter 300 between the inverter 300 and the battery 400. Capacitor 800 smoothes power between inverter 300 and battery 400.

  The inverter 300 includes six IGBTs (Insulated Gate Bipolar Transistors) 310 to 360, six diodes 311 to 361 connected in parallel to each IGBT so that current flows from the emitter side to the collector side of the IGBT, Six IGBT drive circuits 312 to 362 that are connected to the IGBTs and that drive the IGBTs based on signals generated by the control circuit 370 are included. In order to correspond to each phase (U phase, V phase, W phase), IGBT 310 and IGBT 320, IGBT 330 and IGBT 340, and IGBT 350 and IGBT 360 are connected in series, respectively. The inverter 300 converts AC power into DC power or converts DC power into AC power by turning on / off each IGBT.

  A capacitor 900 is connected in parallel with the rear inverter 500 between the rear inverter 500 and the battery 400. Capacitor 900 smoothes the electric power between rear inverter 500 and battery 400.

  As with the inverter 300, the rear inverter 500 includes six IGBTs 510 to 560, six diodes 511 to 561 connected in parallel to each IGBT so that current flows from the emitter side to the collector side of the IGBT, Six IGBT drive circuits 512 to 562 that are connected to the IGBTs and drive the IGBTs based on signals generated by the control circuit 570 are included. In order to correspond to each phase (U phase, V phase, W phase), IGBT 510 and IGBT 520, IGBT 530 and IGBT 540, and IGBT 550 and IGBT 560 are connected in series, respectively. The rear inverter 500 converts AC power into DC power or converts DC power into AC power by turning on / off each IGBT.

  The control circuit 370 and the control circuit 570 calculate each IGBT on / off ratio (duty ratio) based on the depression amount of an accelerator pedal (not shown), the opening degree of a throttle (not shown), and the like. The IGBT is driven with the set duty ratio.

  With reference to FIG. 3, inverter 300 and capacitor 800 will be further described. Capacitor 800 is held in capacitor case 802. The positive electrode and the negative electrode of capacitor 800 are connected to inverter 300 by a positive electrode bus bar 804 and a negative electrode bus bar 806, respectively.

  The inverter 300 is held on the lower surface of the inverter case 372 via an insulating sheet. The inverter case 372 includes a plurality of cooling fins 374 provided so as to protrude upward from the lower surface of the concave portion opened upward. The recess of the inverter case 372 is sealed with the lower surface of the capacitor case 802.

  Cooling water is circulated in a space surrounded by the inverter case 372, the cooling fins 374 and the capacitor case 802. That is, the cooling passage 376 is formed by being surrounded by the inverter case 372, the cooling fins 374 and the capacitor case 802. The cooling water flows into the cooling passage 376 from an inlet (not shown) provided in the inverter case 372 and flows out from an outlet (not shown) provided in the inverter case 372. A cooling medium other than cooling water may be circulated. Inverter 300 is cooled by heat exchange with cooling water flowing into cooling passage 376. For example, an electric device other than the inverter 300 such as a converter may be cooled.

  With reference to FIG. 4, rear inverter 500 and capacitor 900 will be further described. Rear inverter 500 and capacitor 900 are housed in inverter case 572 together with control circuit 570. The upper opening of the inverter case 572 is sealed with a cover 574.

  Rear inverter 500 and capacitor 900 are connected by a DC input bus bar 576. The DC input bus bar 576 is connected to the input connector 578. DC input bus bar 576 is connected to battery 400 via input connector 578.

  An output bus bar 580 is connected to the rear inverter 500 on the opposite side of the connecting portion between the rear inverter 500 and the DC input bus bar 576. The output bus bar 580 is connected to the output connector 582. Output bus bar 580 is connected to rear motor generator 600 via output connector 582.

  A Peltier element 700 is provided below the rear inverter 500 and on the lower surface of the inverter case 572. Cooling fins 702 are provided on the lower surface of the Peltier element 700. Air is supplied to the cooling fin 702 from at least one of the vehicle interior and the vehicle exterior.

  The upper surface of the Peltier element 700, that is, the joint surface between the inverter case 572 and the Peltier element 700 is a heat absorbing surface. The lower surface of the Peltier element 700, that is, the joint surface between the Peltier element 700 and the cooling fin 702 is a heat dissipation surface.

  The Peltier element 700 may be provided above the rear inverter 500 and on the upper surface of the cover 574, and the cooling fin 702 may be provided on the upper surface of the Peltier element 700. In this case, the lower surface of the Peltier element 700 is a heat absorbing surface, and the upper surface is a heat radiating surface.

  The operation of the drive system according to the present embodiment that is expressed based on the above configuration will be described.

  When the inverter 300 generates heat and the inverter 300 needs to be cooled, the cooling water sent from the water pump 302 passes through the pipe 304 and flows into the cooling passage 376. Thereby, the inverter 300 is heat-exchanged with cooling water, and is cooled.

  When the rear inverter 500 generates heat and the rear inverter 500 needs to be cooled, power is supplied to the Peltier element 700 so that heat generated in the rear inverter 500 is transmitted to the cooling fin 702 via the Peltier element 700. Is done. Heat is exchanged between the cooling fins 702 and air. Thereby, rear inverter 500 is cooled.

  As described above, in the drive system according to the present embodiment, the inverter that controls the motor generator that drives the drive shaft connected to the front wheels is cooled by supplying the cooling water. The inverter is provided in the engine room. Therefore, even if the pipe connected to the water pump and the radiator provided in the engine room is provided so as to be connected to the inverter, an increase in the total length of the pipe is suppressed. The rear inverter that controls the rear motor generator that drives the drive shaft connected to the rear wheels is cooled by a Peltier element. Thereby, the rear inverter can be cooled without supplying cooling water to the rear inverter. Therefore, it is not necessary to provide a large-scale cooling system in which a water pump and a pipe connected to the radiator provided in the engine room are provided from the engine room to the rear inverter. Therefore, the inverter and the rear inverter can be cooled with a compact configuration.

<Second Embodiment>
With reference to FIG. 5, a drive system according to a second embodiment of the present invention will be described. In the first embodiment described above, the Peltier element is bonded to the lower surface of the inverter case. However, in the present embodiment, the Peltier element is accommodated in the inverter case. The cooling fin is formed integrally with the inverter case. Other configurations are the same as those in the first embodiment. The function about them is the same. Therefore, detailed description thereof will not be repeated.

  As shown in FIG. 5, the Peltier element 700 is provided on the bottom surface in the inverter case 572 so as to be joined to the lower surface of the rear inverter 500. The cooling fins 702 are formed integrally with the inverter case 572 under the inverter case 572. Even if it does in this way, the effect similar to the above-mentioned 1st Embodiment can be acquired.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a control block diagram showing a vehicle equipped with a drive system according to a first embodiment of the present invention. It is a circuit diagram which shows an inverter and a rear inverter. It is sectional drawing which shows the inverter in the drive system which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the rear inverter in the drive system which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the rear inverter in the drive system which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  100 Engine, 106 Drive shaft, 108 Front wheel, 200 Motor generator, 300 Inverter, 302 Water pump, 304 Pipe, 306 Radiator, 372 Inverter case, 374 Cooling fin, 376 Cooling passage, 400 Battery, 500 Rear inverter, 600 Rear motor generator , 604 drive shaft, 606 rear wheel, 700 Peltier element, 702 cooling fin.

Claims (3)

A drive system for a vehicle having at least a first axle and a second axle different from the first axle,
A first rotating electrical machine that drives the first axle;
An engine that drives a second axle;
A first electric device that is provided not on the engine side but on the first rotating electrical machine side and controls the first rotating electrical machine,
The first electric device is a vehicle drive system that is cooled using a Peltier element. The drive system is
A second rotating electrical machine that drives the second axle in cooperation with the engine;
A second electric device that is provided on the engine side instead of the first electric device side and controls the second rotating electrical machine;
A refrigerant pump that is provided on the engine side instead of the first electric device side and supplies a cooling medium to the second electric device;
The vehicle drive system according to claim 1, wherein the second electric device is cooled by a cooling medium supplied by the refrigerant pump.   3. The vehicle drive according to claim 1, wherein the second axle and the engine are provided at a front portion of the vehicle, and the first axle and the first rotating electrical machine are provided at a rear portion of the vehicle. system.

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