JP2011084253A - Cooling system in right-left independent drive vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling system for cutting off or shielding influence of heat on motors for respectively driving right-left wheels from a heat source, in a right-left independent drive vehicle. <P>SOLUTION: This right-left independent drive vehicle has the motors MFR and MFL for individually driving the right-left wheels of making a pair of the right and left, an engine 1 and an intake part of air for cooling the engine 1. The engine 1 is isolated by a heat shielding plate 4, and the temperature-raised air taken in for cooling the engine 1 is made to flow by avoiding the motors MFR and MFL. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a vehicle configured to drive a pair of left and right wheels with electric motors provided in correspondence with each other, and particularly to a cooling device that suppresses or prevents a temperature rise of the electric motors.

  In addition to the internal combustion engine, an electric motor has come to be used as a driving force source for the vehicle, and accordingly, a motor is prepared for each wheel, and the wheels are individually driven. When the temperature of such an electric motor or a power conversion device such as an inverter or a converter electrically connected to the electric motor rises, there is a possibility that the output suppression control is activated and a desired torque cannot be output. Therefore, Patent Document 1 describes an invention that cools an electric motor or a power conversion device by sending cooling air that has passed through a radiator to a place where the electric motor or the power conversion device is mounted. In the invention described in Patent Document 1, the center portion of the front wall portion of the dash panel in the engine room is projected forward, and the cooling air that has passed through the radiator is transferred to the wheel on which the left and right wheels are mounted. The structure which cools a wheel with the cooling air by sending is described.

  As a method for cooling the in-wheel motor, a method of cooling using cooling oil is known. In Patent Document 2, in a traction motor provided in each of the left and right wheels and an in-wheel motor provided with an oil supply mechanism, temperature detection means for the traction motor is provided, and the temperature at which the efficiency of the traction motor is maximized is set as a target temperature. An invention for controlling the supply amount is described. Furthermore, as another cooling device, an inverter that drives and controls the in-wheel motor is mounted on the fender apron so that the heat generated by the inverter is dissipated to the vehicle body via the fender apron and is taken into the vehicle by the vehicle traveling. An apparatus for cooling an inverter with wind is described in Patent Document 3.

JP 2005-112113 A JP 2008-195233 A JP 2007-161111 A

  The structure described in Patent Document 1 described above cools the wheel with the cooling air that has passed through the radiator. However, since the engine is hot during traveling, the cooling water of the radiator that cools the engine may also be hot. In that case, since the outside air is heated by the radiator, the heated air is sent to the wheel. According to the experiment, the air temperature when the outside air reaches the wheel is about 40 ° C. higher than the outside air (see FIG. 6). Therefore, there is a cooling effect for a brake having a temperature of several hundred degrees C., such as a brake provided on the wheel, but it may act as a heat dissipation suppression for an in-wheel motor having a low operating efficiency. Therefore, there is room for improvement in terms of cooling the in-wheel motor.

  Further, the control device described in Patent Document 2 is configured to cool the traction motor with oil, and Patent Document 3 further cools the inverter by heat radiation to the vehicle body and heat radiation by the outside air. In addition, there is still room for improvement in terms of improving the cooling performance of the motor without considering the thermal effects of the engine and transmission mechanism installed together.

  This invention was made against the background of the above circumstances, and for the electric motors provided on the left and right wheels, to improve the durability of the electric motor by blocking the influence of heat on the electric motor from the outside of the electric motor. It is an object of the present invention to provide a cooling device that can be used.

  In order to achieve the above object, the invention of claim 1 includes a left and right motor including an electric motor that individually drives a pair of left and right wheels, a heat generation source, and an air intake for cooling the heat generation source. A left and right independent drive vehicle characterized in that in the cooling device for an independent drive vehicle, the vehicle is provided with air guiding means configured to flow the air that has been taken in to cool the heat generation source and is heated to avoid the electric motor. In the cooling device.

  According to a second aspect of the present invention, in the first aspect of the present invention, the guiding means is incorporated into the heat shield plate provided between the heat source and the electric motor and cooled to cool the heat source. It is a cooling device in a left and right independent drive vehicle characterized by being a discharge port for discharging warm air upward.

  Further, the invention of claim 3 is the flow according to claim 1 or 2, wherein the flow path of the air introduced toward the electric motor is branched so that the air flows between the electric motor and the heat generation source. A cooling device for a left and right independent drive vehicle characterized by comprising a road branching means.

  According to the first aspect of the present invention, the air whose temperature has been raised by the heat generation source flows away from the electric motor. Therefore, the temperature of the air around the motor is not affected by the heat of the heat generation source, so that the cooling performance of the motor can be ensured and the running stability of the vehicle can be maintained in a good state.

  According to the invention of claim 2, the air taken in for cooling the heat source is discharged in the direction opposite to the direction in which the wheels are mounted, that is, in the upper direction with respect to the vehicle. The same effect as the invention can be obtained.

  Furthermore, according to the invention of claim 3, since air flows between the electric motor and the heat generation source, in addition to the effects of the first and second aspects, the influence of temperature by the heat generation source can be further suppressed. .

It is the schematic of the cross section of the front part of the vehicle which shows an example of the vehicle made into object with the cooling device which concerns on this invention. It is a general view which shows the flow of the air of the cooling device concerning this invention. It is the schematic of the vehicle cross section which shows the other example of the vehicle made into object by the cooling device which concerns on this invention. It is the schematic of the vehicle front part which shows the further another example of the vehicle made into object by the cooling device which concerns on this invention. It is the schematic of the front part cross section of the vehicle which shows the further another example of the vehicle made into object by the cooling device which concerns on this invention. It is a graph which shows the experimental result which investigated the relationship between the temperature in a wheel performed with the conventional cooling structure (patent document 1), and the wind speed from a radiator.

  Next, the present invention will be described based on a specific example shown in the drawings. FIG. 1 conceptually shows an example of a vehicle front portion that can be the subject of the present invention. The vehicle shown here has motors MFR and MFL built in left and right front wheels 1FR and 1FL, respectively. In this example, the left and right rear wheels (not shown) are driven by motors MFR and MFL and are driven by a so-called hybrid device. In other words, motors MFR and MFL are provided corresponding to the left and right front wheels 1FR and 1FL that are steered by a steering device (not shown), and these motors MFR and MFL have a power generation function such as a permanent magnet synchronous motor. It is a motor provided with. Each of the motors MFR and MFL is electrically connected to a power storage device (not shown) via a controller such as an inverter (not shown). Therefore, when the vehicle is running, electric power is supplied from the power storage device to function as a motor, and during braking, the motor is forcibly rotated to generate power and charge the power storage device. Yes.

  The motors MFR and MFL provided on the left and right front wheels 1FR and 1FL are so-called in-wheel motors. A traction motor composed of a stator and a rotor, a cooling mechanism for cooling the traction motor, and the traction motor include A deceleration mechanism that increases the output torque is provided. The left and right front wheels 1FR, 1FL are provided with brakes.

  Next, the hybrid device for driving the rear wheels will be described. The engine 1 corresponding to the heat source in the present invention is provided, and the output shaft of the engine 1 is connected to the hybrid transmission (HVT / M) 2. Yes. The engine 1 is basically an internal combustion engine that obtains power by burning fuel, and examples thereof include a gasoline engine, a diesel engine, or an LPG engine. As an example of the hybrid transmission 2, a sun gear, a ring gear that is an internal gear concentrically arranged with respect to the sun gear, and a sun gear and a ring gear that are arranged between the sun gear and the ring gear. This is a so-called planetary gear mechanism in which a pinion gear meshing with each other is held rotatably and revolved by a carrier. A motor / generator is connected to the carrier, and another motor / generator is connected to the output shaft of the ring gear. Each of these motor / generators is electrically connected to a power storage device such as a battery or a capacitor via a controller such as an inverter.

  The output shaft of the planetary gear mechanism is connected to a power transmission mechanism such as a stepped or continuously variable transmission or a propeller shaft, and further to the left and right rear wheel shafts via a final reduction gear (differential gear). It is connected.

  Briefly explaining the operation of this hybrid device, the power output from the engine 1 is distributed to the motor / generator and the output shaft by the power distribution device. In this case, the motor / generator functions as a generator to give the sun gear a torque in the direction of reducing its rotation (that is, negative torque), and the rotational speed of the engine 1 is appropriately controlled by controlling the rotational speed. Can be controlled. Further, the engine 1 can be controlled to be stopped. Therefore, the power distribution device and the motor / generator can function as a continuously variable transmission or an electric torque converter. On the other hand, the electric power generated by the motor / generator is supplied to another motor / generator via a controller such as an inverter or a power storage device, and the other motor / generator operates as a motor. That is, the power distributed to the motor / generator side is transmitted to the output shaft. Therefore, the engine 1 can be operated at the optimum fuel consumption point while satisfying the output request.

  The hybrid transmission 2 including the engine 1, each motor / generator, and the planetary gear mechanism described above is mounted in an engine room. Further, as shown in FIG. 1, a radiator 3 is mounted in an engine room, and the radiator 3 cools the engine 1 in order to prevent a decrease in engine performance due to the engine 1 becoming hot. The radiator 3 is composed of a water pipe, a fin, a frame, and the like. The cooling method by connecting the water pipe of the radiator 3 and the water jacket of the engine 1 and supplying the cooling water of the radiator 3 to the engine 1 and the outside air. There is a cooling method by sending it to the engine 1 through the fins of the radiator 3. The engine 1 is configured to maintain the optimum temperature by these cooling methods.

  The apparatus of the present invention prevents the influence of heat from the engine 1 described above on the motors MFR and MFL provided on the left and right front wheels, and will be described below with reference to the drawings. FIG. 1 is a schematic view of the front portion of the vehicle as described above, and the engine 1, the hybrid transmission 2, the radiator 3, and the like are mounted in the engine room. Further, a heat shield plate 4 is arranged so as to shield the engine room and the wheel from heat. And the ventilation duct 5 is provided so that external air can be directly supplied toward a wheel from the front. Furthermore, a vent 6 (see FIG. 2) is formed in the bonnet so as to discharge the air taken into the engine room to the outside.

  With such a configuration, the engine 1 is cooled by the outside air that has passed through the radiator, and the air that has been heated by the engine 1 is discharged out of the vehicle through the vent 6 on the hood. Then, by sending air from other air supply locations to the wheel via the ventilation duct 5, the air can cool the motors MFR and MFL without being affected by the heat of the engine 1. Further, heat radiation from the engine 1 to the motors MFR and MFL is shielded by the heat shield plate 4. That is, the influence of direct heat is cut off between the engine room and the motor, and since the outside air is supplied to each of the engine 1 and the motor, the influence of indirect heat due to the air heated by the engine 1 is also prevented. be able to. Therefore, the temperature in the vicinity of the wheel can be maintained at a room temperature, and the cooling efficiency of the in-wheel motor can be improved. Note that the heat shield plate 4 only needs to be able to cut off the heat source and the motor. Therefore, the heat shield plate 4 may be one that surrounds only the engine 1 in the engine room, for example, instead of the arrangement shown in this configuration example.

  Further, the heat source in the present invention is not limited to the internal combustion engine such as the engine 1, but may be a power storage device such as a fuel cell or a battery used in an electric vehicle. An example in which the present invention is applied to an electric vehicle will be described below with reference to FIG. First, a brief description will be given of the configuration of an electric vehicle to be described in the description of an example of the present invention. Motors MFR, MFL, MRR, and MRL are provided on front, rear, left, and right wheels 1FR, 1FL, 1RR, and 1RL, respectively. Each wheel 1FR, 1FL, 1RR, 1RL is provided with a brake, a motor, etc., like each front wheel of the above-described configuration example, and the motor is a traction motor constituted by a stator and a rotor, and cooling oil for cooling the motor. Etc. Each motor MFR, MFL, MRR, MRL is electrically connected to a power storage device such as a battery or a capacitor via a controller such as an inverter (not shown). Therefore, it functions as a motor by supplying power from the power storage device, and on the contrary, it functions as a generator that generates power by forcibly rotating the motor and charges the power storage device with the generated power. Each motor outputs the number of rotations and the like under the control of an electronic control unit (ECU) (not shown) mainly composed of a microcomputer. Furthermore, this vehicle is equipped with a fuel cell 7 (FC stack) that generates electric power by a chemical reaction or the like. By appropriately selecting and supplying the electric power of the fuel cell 7 and the electric power stored in the power storage device, Each motor MFR, MFL, MRR, MRL is configured to be driven.

  In such an electric vehicle, similarly to the above-described vehicle using the internal combustion engine as a power source, the temperature of the power source such as the fuel cell 7 and the battery 8 rises due to supply of electric power or charging. A configuration for blocking the influence of the heat is shown in FIG. 3, and a broken line is the heat shield plate 4. In the example shown in FIG. 3, the fuel cell 7 and the battery 8 are mounted on the front part of the vehicle, and the heat shield 4 is disposed around the fuel cell 7 and the battery 8 so as to isolate them. Thus, by isolating the fuel cell 7 and the battery 8 which are heat sources with the heat shield plate 4, the wheel is not affected by the heat generated from them, and the cooling efficiency of the in-wheel motor can be improved. . Although not shown in FIG. 3, a ventilation port and a discharge port for cooling a heat source such as the fuel cell 7 and the battery 8 may be provided at a place where the wheel does not have an influence of heat. Similarly, it is possible to provide a vent for each wheel and cool the wheel with outside air.

  Further, in addition to the above-described two configuration examples that prevent the influence of heat by the heat shield plate 4, there are also configuration examples in which heat can be shielded by air as shown in FIGS. 4 and 5. Explaining this configuration example, first, similarly to the two configuration examples described above, the heat source 9 is mounted between the left and right wheels 1FR and 1FL or in the vicinity of either the left or right wheel. The air introduction port is provided in front of the vehicle, and the air flow path or the ventilation path is branched until reaching the wheel. One of the branched flow paths W1 passes through the wheel as it is to cool the wheel, and the other flow path W2 passes between the heat source 9 and the wheel. And the air which passed between the heat source 9 and a wheel provides a discharge port toward the inside of the wheel and upward and rearward with respect to the vehicle, and discharges or exhausts air. By setting it as such a structure, the heat emitted from the heat source 9 is discharged | emitted back by the flow of the air while reaching a wheel. Therefore, since the wheel is not affected by the heat source 9, the cooling efficiency of the in-wheel motor can be improved.

  The present invention has the above-described configuration, and a heat shield is provided between a so-called heat generation source such as an internal combustion engine or a fuel cell and an electric motor to isolate the heat source so that the electric motor is not affected by heat. It is possible to improve the cooling efficiency of the motor without raising the temperature around the motor.

  Here, the relationship between each of the above-described specific examples and the present invention will be briefly described. The internal combustion engine and the fuel cell described above correspond to the heat generation source in the invention of claim 1 and are provided on the heat shield plate and the hood. The discharge port corresponds to the guiding means in the first and second aspects of the invention. Further, the air flow path for cooling the wheel house and the air flow path flowing between the heat source and the motor correspond to the flow path branching means in the invention of claim 3.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Hybrid transmission (HVT / M), 3 ... Radiator, 4 ... Heat shield, 5 ... Ventilation duct, 6 ... Ventilation opening, 7 ... Fuel cell (FC stack), 8 ... Battery, 9 ... Heat source 1FL, 1FR, 1RL, 1RR ... wheels, W1, W2 ... flow paths, MFR, MFL, MRR, MRL ... motors.

Claims (3)

An electric motor that individually drives a pair of left and right wheels;
A heat source,
A cooling device for a left and right independent drive vehicle, comprising: an air intake for cooling the heat source;
A cooling device for a left and right independent drive vehicle, comprising air guiding means configured to flow air that has been taken in to cool the heat generation source and that has been heated to avoid the electric motor. A heat shield provided between the heat source and the electric motor, and the induction means;
The cooling device for a left and right independent drive vehicle according to claim 1, wherein the cooling device is a discharge port for discharging upwardly heated air taken in to cool the heat generation source.   A flow path branching unit for branching into a direction in which the air flow path introduced toward the electric motor passes toward the electric motor and a direction in which air passes between the electric motor and the heat generation source is provided. The cooling device in the left and right independent drive vehicle according to claim 1 or 2.

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