Patent ID: 12257905

MODES FOR CARRYING OUT THE INVENTION

A detailed description will hereinafter be made on an exemplary embodiment with reference to the drawings. In the following description, a vehicle front-rear direction will simply be referred to as a “front-rear direction,” a vehicle front side will simply be referred to as a “front side,” and a vehicle rear side will simply be referred to as a “rear side.” A vehicle width direction is a right-left direction of the vehicle, a vehicle left side will simply be referred to as a “left side,” and a vehicle right side will simply be referred to as a “right side.” In addition, in the right-left direction, the left side at the time when the front side is seen from the rear side will be referred to as left, and the right side at such time will be referred to as right.

FIG.1is a block diagram illustrating a drive system of an electric vehicle according to the exemplary embodiment.FIG.2is a plan view schematically illustrating a power unit.FIG.1andFIG.2schematically illustrate a drive system of a vehicle1, and arrangement of each component does not limit actual arrangement of each of the components.

The vehicle1is a series hybrid vehicle. The vehicle1includes a power unit P that is constructed of an electric drive unit10for driving the vehicle1by using electric power and an engine body8for generating the electric power. The electric drive unit10has a drive motor5that drives the vehicle by using the electric power, a reduction drive6that reduces power from the drive motor5and outputs the reduced power, and a generator7that generates the electric power to be supplied to the drive motor5.

An engine has the engine body8and engine-related components. The engine body8is primarily used to drive the generator7for the electric power generation, and the power for driving the vehicle1is generated by the drive motor5. The power generated by the drive motor5is shifted by the reduction drive6, and is thereafter transmitted to drive wheels92(front wheels herein) via a differential91.

The vehicle1includes a high-voltage battery B1and a low-voltage battery B2. The high-voltage battery B1is charged with electricity that is generated by the generator7. An electric power generation inverter102is provided between the generator7and the high-voltage battery B1. The electric power generation inverter102is electrically connected to the generator7and the high-voltage battery B1. The generated electricity from the generator7is supplied to the high-voltage battery B1via the electric power generation inverter102. A motor inverter101is provided between the drive motor5and the high-voltage battery B1. The motor inverter101is electrically connected to the drive motor5and the high-voltage battery B1. The motor inverter101converts the electricity from the high-voltage battery B1into the electric power for driving the drive motor5, and outputs the electric power to the drive motor5. ADC/DC converter103is provided between the high-voltage battery B1and the low-voltage battery B2. The DC/DC converter103is electrically connected to the high-voltage battery B1and the low-voltage battery B2. The electricity from the high-voltage battery B1is supplied to the low-voltage battery B2via the DC/DC converter103. The generated electricity from the generator7is supplied to the low-voltage battery B2via the electric power generation inverter102and the DC/DC converter103. The motor inverter101, the electric power generation inverter102, and the DC/DC converter103integrally constitute an electric power conversion unit100.

FIG.3is a perspective view in which a power unit compartment2is seen from a front left side. As illustrated inFIG.2andFIG.3, the vehicle1includes a right and left pair of body side frames31in a front portion thereof, and the right and left pair of the body side frames31at least extends in the front-rear direction and is arranged on both sides in the vehicle width direction. A subframe34that has a side member34aextending in the front-rear direction is fastened to a lower portion of each of the body side frames31.

The power unit P is disposed in the power unit compartment2that is formed by the body side frames31and the subframes34. The power unit P is supported between the right and left body side frames31,31via support members38, each of which is provided to the respective body side frame31.

The electric power conversion unit100, in which the motor inverter101, the electric power generation inverter102, and the DC/DC converter103are integrated, is disposed above a drive unit housing9for accommodating the drive motor5, the reduction drive6, and the generator7. The engine-related components such as an air cleaner106, an oil filter107a, an oil cooler107b, and the low-voltage battery B2are arranged above the engine body8.

FIG.4is a front view of the power unit P. The drive motor5, the reduction drive6, and the generator7are accommodated in the drive unit housing9. The drive unit housing9is integrally formed by coupling a first housing11, a second housing12, a third housing13, and a fourth housing14in the vehicle width direction. In detail, the second housing12and the third housing13in substantially cylindrical shapes, each of which extends in the vehicle width direction, are coupled to each other, and openings on both of right and left sides thereof are closed by the first housing11and the fourth housing14. In this way, the drive unit housing9is constructed. In an upper portion of the third housing13, an actuator105is arranged near the front. In addition, an engine case15that accommodates the engine body8is integrated with the drive unit housing9.

The first housing11, the second housing12, the third housing13, the fourth housing14, and the engine case15are integrated such that cylindrical circumferential wall portions with substantially the same diameter are coupled in a continuous manner. In particular, upper end portions of the first housing11, the second housing12, the third housing13, the fourth housing14, and the engine case15continue such that the circumferential wall portions are substantially flush. In this way, the drive motor5, the reduction drive6, the generator7, and the engine body8are integrally arranged in this order in the vehicle width direction of the power unit compartment2such that heights thereof are substantially the same.

FIG.5is a view schematically illustrating an end surface that is taken along a plane corresponding to line V-V inFIG.2, andFIG.6is a view schematically illustrating an end surface that is taken along a plane corresponding to line VI-VI inFIG.2. InFIG.5andFIG.6, structures of the drive motor5, the reduction drive6, the generator7, and the engine body8are omitted or simplified.

In the drive unit housing9, the first housing11is located on the outermost side in the vehicle width direction and faces the body side frame31and the subframe34. In an upper portion of the first housing11, a right end portion of the power unit P is supported by the support member38. The first housing11is provided with a first bearing section21a. The first bearing section21arotatably supports a tip20aon one side of a motor shaft20.

The second housing12is coupled to a left side of the first housing11. A cylindrical internal space of the second housing12is partitioned in the vehicle width direction by a partition wall12a. In a substantially central portion of the partition wall12a, a through hole12bis provided to allow the motor shaft20to pass therethrough in the vehicle width direction. On the right side of the partition wall12a, the drive motor5is arranged in a drive motor accommodating section5athat is formed by the first housing11and the second housing12. On the left side of the partition wall12a, the reduction drive6is arranged in a reduction drive accommodating section6athat is formed by the second housing12and the third housing13. In addition, the partition wall12ais provided with a fifth bearing section62aat a position behind the motor shaft20. The fifth bearing section62arotatably supports one end portion of an intermediate shaft62of the reduction drive6.

The third housing13is coupled to the left side of the second housing12. The third housing13has a partition wall13ain a right end portion thereof, and the partition wall13apartitions the third housing13in the vehicle width direction into the reduction drive accommodating section6aand a generator accommodating section7a. In a substantially central portion of the partition wall13a, a through hole13bis provided to allow the motor shaft20to pass therethrough in the vehicle width direction. A boss is formed in a circumferential edge portion of the through hole13b, and the boss is projected to both of the right and left sides from the partition wall13a. A second bearing section21bis provided to an end portion on the reduction drive accommodating section6aside of the through hole13b. The second bearing section21brotatably supports the motor shaft20. A third bearing section51ais provided to an end portion on the generator accommodating section7aside of the through hole13b. The third bearing section51arotatably supports one end portion of a generator shaft50. In addition, the partition wall13ais provided with a sixth bearing section62bat a position behind the motor shaft20. The sixth bearing section62brotatably supports the other end portion of the intermediate shaft62of the reduction drive6.

On the left side of the partition wall13a, the fourth housing14is coupled to the third housing13. On the left side of the partition wall13a, the generator7is arranged in the generator accommodating section7athat is formed by the third housing13and the fourth housing14. The fourth housing14is provided with a fourth bearing section51b. The fourth bearing section51brotatably supports the other end portion of the generator shaft50. The fourth housing14is integrally constructed with the engine case15that is located adjacently and on the left side thereof.

The engine case15is coupled to the left side of the drive unit housing9. A left end portion of the engine case15is separated from the body side frame31and the subframe34. In an upper portion of the engine case15, a left end portion of the power unit P is supported by the support member38. The upper end portion of the engine case15is at substantially the same height as an upper end portion of the drive unit housing9.

In the drive unit housing9and the engine case15described above, a rotary shaft80of the engine body8, the generator shaft50of the generator7, and the motor shaft20of the drive motor5extend in the vehicle width direction and are arranged on the same straight line.

The drive motor5includes a rotor and a stator (not illustrated) in addition to the motor shaft20. A rotating magnetic field is generated when three-phase AC power is supplied to the stator, and the rotor and the motor shaft20are rotated by the rotating magnetic field.

The tip20aon the one side of the motor shaft20is rotatably supported by the first bearing section21a, and the motor shaft20runs across the drive motor accommodating section5afrom the first housing11, passes through the partition wall12aof the second housing12, and enters the reduction drive accommodating section6a.

A tip20bon the other side of the motor shaft20runs through the through hole13bfrom the reduction drive accommodating section6aand passes through the partition wall13a. The tip20bon the other side of the motor shaft20is formed to reach the generator accommodating section7afrom the reduction drive accommodating section6a.

In the reduction drive accommodating section6a, the motor shaft20is integrally formed with an input shaft61of the reduction drive6. The input shaft61receives a rotational force of the drive motor5. At a position behind the motor shaft20, the intermediate shaft62of the reduction drive6is arranged to be substantially parallel to the motor shaft20. An unillustrated gear is disposed between the input shaft61and the intermediate shaft62. The intermediate shaft62transmits the power, which is reduced by the gear, to an output shaft (not illustrated).

The generator7includes a rotor and a stator (not illustrated) in addition to the generator shaft50. When the generator shaft50and the rotor are rotated by the power of the engine body8, the stator generates the electric power due to electromagnetic induction.

The generator shaft50is arranged on the generator7side of the tip20bon the other side of the motor shaft20. The one end portion of the generator shaft50is supported by the third bearing section51a, which is provided to the third housing13, and the other end portion thereof is supported by the fourth bearing section51b, which is provided to the fourth housing14. The motor shaft20and the generator shaft50are spaced apart in the vehicle width direction and arranged on a straight line.

The rotary shaft80of the engine body8is arranged on the left side of the generator shaft50. The generator shaft50and the rotary shaft80of the engine body8are spaced apart in the vehicle width direction and arranged on the straight line.

The engine body8is arranged adjacently on the left side of the generator7. The engine body8is preferably a rotary engine. The rotary engine has a vertically compact structure when compared to a reciprocating engine, which makes it easy to substantially equalize the heights of the drive motor5, the reduction drive6, the generator7, and the engine body8. For this reason, these components can be arranged compactly.

The engine-related components are arranged above the engine body8. The engine-related components include intake-related components that are arranged in front of the engine body8, fuel and oil-related components that are arranged directly above the engine body8, and the low-voltage battery B2that is arranged behind the engine body8. Examples of the intake-related components are the air cleaner106and an intake duct106a. Examples of the fuel and oil-related components are the oil filter107aand the oil cooler107b.

The intake-related components and exhaust-related components are provided in front of the engine body8. Examples of the intake-related components are the air cleaner106and the intake duct106a. Examples of the exhaust-related components are an exhaust manifold (not illustrated) and an exhaust pipe108that continues from the exhaust manifold. That is, the engine body8is a forward-intake type and a forward-exhaust type.

As illustrated inFIG.2andFIG.6, the low-voltage battery B2and the air cleaner106as the engine-related components are arranged to be projected outward from the engine body8in the vehicle width direction. More specifically, the low-voltage battery B2is arranged above the left support member38in an overlapping manner. The air cleaner106is arranged in front of the low-voltage battery B2in a manner to be projected leftward from a position above the left body side frame31. Thus, a space is provided on the lateral side of the engine body8and below the low-voltage battery B2and the air cleaner106. By using such a space, the exhaust-related components such as an exhaust pipe108extend from a position in front of the engine body8, run through the lateral side of the engine body8and below the low-voltage battery B2and the air cleaner106, and are routed behind the engine body8.

As it has been described so far, according to this embodiment, the drive motor5, the reduction drive6, the generator7, and the engine body8are integrally arranged in this order in the vehicle width direction of the power unit compartment2such that the heights thereof are substantially the same. Then, the electric power conversion unit100, in which the motor inverter101, the electric power generation inverter102, and the DC/DC converter103are integrated, is arranged above the drive unit housing9, which accommodates the drive motor5, the reduction drive6, and the generator7. The engine-related components such as the air cleaner106, the intake duct106a, the oil filter107a, the oil cooler107b, and the low-voltage battery B2are arranged above the engine body8. Since the electric power conversion unit100and the engine-related components can separately be arranged at the position above the drive unit housing9and the position above the engine body8, respectively, it is possible to compactly arrange the power unit P, the electric power conversion unit100, and the engine-related components.

In addition, the engine body8is the rotary engine, and the rotary shaft80thereof and the motor shaft20of the generator shaft50are arranged to extend in the vehicle width direction on the same straight line. Therefore, the further compact configuration can be obtained by setting the heights of the drive motor5, the reduction drive6, the generator7, and the engine body8to be substantially the same.

Furthermore, the engine body8is the forward-intake type and the forward-exhaust type. The intake-related components, such as the air cleaner106and the intake duct106a, are arranged in front of the engine body8. The oil-related components, such as the oil filter107aand the oil cooler107b, are arranged directly above the engine body8. The low-voltage battery B2is arranged behind the engine body8. In this way, it is possible to appropriately arrange the engine-related components in the front-rear direction at the position above the engine body8.

Moreover, the low-voltage battery B2, the air cleaner106, and the intake duct106aare arranged to be projected outward from the engine body8in the vehicle width direction. Accordingly, the exhaust-related components such as the exhaust pipe108can run through the lateral side of the engine body8and below the low-voltage battery B2, the air cleaner106, and the intake duct106a, and be routed behind the engine body8. Thus, the engine-related components including the exhaust-related components can be arranged compactly.

The above-described embodiment is merely illustrative, and thus the scope of the present disclosure should not be interpreted in a restrictive manner. The scope of the present disclosure is defined by the claims, and all modifications and changes falling within equivalents of the claims fall within the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

The technique disclosed herein is useful as the electric vehicle in which the power unit, the electric power conversion unit, and the engine-related components are arranged compactly.

DESCRIPTION OF REFERENCE CHARACTERS

1Vehicle2Power unit compartment5Drive motor6Reduction drive7Generator8Engine body9Drive unit housing20Motor shaft50Generator shaft80Rotary shaft100Electric power conversion unit101Motor inverter102Electric power generation inverter103DC/DC converter106Air cleaner106aIntake duct107aOil filter107bOil cooler108Exhaust pipeB1High-voltage batteryB2Low-voltage batteryP Power unit