Electric vehicle

Abstract

To provide an electric vehicle capable of improving safety in a state of collision from the rear side.SOLUTION: An electric vehicle includes: a pair of trailing arms which is mounted on rear wheels and a vehicle body and is separated from each other in a vehicle width direction; an intermediate beam for connecting the pair of trailing arms; a drive shaft which is positioned on the rear side of the intermediate beam and is configured to drive the rear wheels; a motor generator which has a rotor with a central axis of rotation extending in a direction crossing a central axis of rotation of the drive shaft and is positioned on the rear side of the drive shaft; a deferential gear which is configured to transmit rotation of the rotor to the drive shaft; and a fuel tank or a battery which is positioned on the front side of the intermediate beam.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric vehicle.

Background Art

[0002] In an electric vehicle such as a hybrid car or an electric car, a motor generator drives wheels via, for example, a differential gear and a drive shaft. For example, Patent Document 1 discloses an electric vehicle in which a motor drives wheels via a pinion and a ring gear.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an electric vehicle, a motor generator and a fuel tank or a battery may be arranged in the vicinity of each other. For example, when the electric vehicle is rear-ended, the motor generator may collide with the fuel tank or the battery.

[0005] An object of the present invention is to provide an electric vehicle capable of improving safety when rear-ended.

Means for Solving the Problems

[0006] To achieve the above object, an electric vehicle according to the present invention includes a pair of trailing arms each attached to a rear wheel and a vehicle body and spaced apart from each other in the vehicle width direction, an intermediate beam connecting the pair of trailing arms, a drive shaft located behind the intermediate beam and configured to drive the rear wheel, a motor generator having a rotor whose central axis of rotation extends in a direction intersecting the central axis of rotation of the drive shaft and located behind the drive shaft, a differential gear configured to transmit the rotation of the rotor to the drive shaft, and a fuel tank or a battery located in front of the intermediate beam. A muffler for reducing noise, The electric vehicle includes: the intermediate beam is located between the motor generator and the fuel tank or the battery, and the motor generator is arranged such that the central axis of rotation of the rotor extends in the front-rear direction intersecting the vehicle width direction. and the muffler is arranged side by side with the motor generator in the vehicle width direction .

[0007] According to this configuration, when the electric vehicle is rear-ended, the intermediate beam can receive the motor generator and prevent the motor generator from reaching the fuel tank or the battery. Therefore, the electric vehicle can prevent the motor generator from damaging the fuel tank or the battery when the electric vehicle is rear-ended, and improve safety.

[0008] Further, in the electric vehicle according to the present invention, at least a part of the intermediate beam is located at the same height as the motor generator in the vertical direction.

[0009] According to this configuration, when the electric vehicle is rear-ended, the intermediate beam can more reliably receive the motor generator and prevent the motor generator from damaging the fuel tank or the battery.

[0010] Further, the electric vehicle according to the present invention further includes a power control unit that controls the motor generator, and the power control unit is arranged side by side with the motor generator in the vehicle width direction.

[0011] According to this configuration, the electric vehicle can reduce the size in the front-rear direction of the E-Axle including the power control unit and the motor generator, as compared with the case where the power control unit is arranged in parallel with the motor generator in the front-rear direction.

Effect of the Invention

[0012] According to the present invention, when the electric vehicle is rear-collided, it is possible to prevent the motor generator from damaging the fuel tank or the battery, and improve safety.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the electric vehicle will be described with reference to FIGS. 1 to 3. In this specification, the components according to the embodiments and the description of the components may be described in a plurality of expressions. The components and the description thereof are examples and are not limited by the expressions in this specification. The components may be specified by different names from those in this specification. Also, the components may be described by expressions different from those in this specification.

[0015] FIG. 1 is a schematic plan view showing a part of an electric vehicle 10. In the present embodiment, the electric vehicle 10 is a hybrid vehicle (HV). Note that the electric vehicle 10 may be a plug-in hybrid vehicle (PHEV), an electric vehicle (EV), a fuel cell vehicle (FCV), or another type of vehicle that uses electricity for driving force.

[0016] As shown in the respective drawings, in this specification, for convenience, the X-axis, Y-axis, and Z-axis are defined. The X-axis, Y-axis, and Z-axis are orthogonal to each other. The X-axis is provided along the vehicle width direction. The Y-axis is provided along the front-rear direction. The Z-axis is provided along the vertical direction.

[0017] Furthermore, in this specification, the X-direction (vehicle width direction), Y-direction (front-rear direction), and Z-direction (vertical direction) are defined. The X-direction is the direction along the X-axis, including the +X direction (left direction) indicated by the arrow of the X-axis and the -X direction (right direction) which is the opposite direction of the arrow of the X-axis. The Y-direction is the direction along the Y-axis, including the +Y direction (front direction) indicated by the arrow of the Y-axis and the -Y direction (rear direction) which is the opposite direction of the arrow of the Y-axis. The Z-direction is the direction along the Z-axis, including the +Z direction (upward direction) indicated by the arrow of the Z-axis and the -Z direction (downward direction) which is the opposite direction of the arrow of the Z-axis.

[0018] The electric vehicle 10 includes a vehicle body 11, a pair of rear wheels 12, a rear suspension 13, a pair of drive shafts 14, an E-Axle 15, a fuel tank 16, and an exhaust pipe (exhaust pipe) 17. Furthermore, the electric vehicle 10 includes front wheels, an engine, a battery, and various other components.

[0019] The vehicle body 11 has, for example, a chassis and a floor panel. For this reason, the vehicle body 11 has a pair of side members 21 and a pair of brackets 22. The pair of side members 21 are spaced apart from each other in the vehicle width direction and are connected to each other by, for example, cross members. Each of the pair of brackets 22 is attached to the corresponding side member 21.

[0020] The rear wheels 12, rear suspension 13, drive shafts 14, E-Axle 15, fuel tank 16, exhaust pipe 17, front wheels, engine, and battery are directly or indirectly supported by the vehicle body 11. The engine is, for example, a gasoline engine. The battery is, for example, a battery pack combined with a plurality of secondary batteries such as lithium-ion batteries.

[0021] The rear suspension 13 is a De Dion type suspension or a torsion beam type suspension. Note that the rear suspension 13 is not limited to this example. The rear suspension 13 has a pair of trailing arms 31 and an intermediate beam 32. The intermediate beam 32 may also be referred to as a torsion beam.

[0022] The pair of trailing arms 31 are spaced apart from each other in the vehicle width direction. The trailing arms 31 extend approximately in the longitudinal direction. Each of the pair of trailing arms 31 is attached to the corresponding rear wheel 12 and the corresponding side member 21. Note that the trailing arm 31 may be attached to other parts of the vehicle body 11.

[0023] For example, a rubber bush 35 is provided at the front end portion 31a of the trailing arm 31. The rubber bush 35 is connected to the bracket 22. Further, the pair of rear wheels 12 are rotatably attached to the rear end portion 31b of the corresponding trailing arm 31.

[0024] The trailing arm 31 is suspended from the vehicle body 11 via a spring. The rear suspension 13 can absorb vibrations acting in the vertical direction on the vehicle body 11 by means of the spring.

[0025] The intermediate beam 32 connects the pair of trailing arms 31. The intermediate beam 32 is attached to the trailing arm 31 at the middle of the two end portions 31a and 31b of the trailing arm 31. The intermediate beam 32 extends substantially in the vehicle width direction.

[0026] FIG. 2 is a schematic cross-sectional view showing a part of the electric vehicle 10 along the line F2-F2 in FIG. 1. FIG. 3 is a schematic rear view showing a part of the electric vehicle 10. As shown in FIG. 2, the intermediate beam 32 has a substantially U-shaped cross-section that is open substantially downward. Note that the shape of the intermediate beam 32 is not limited to this example.

[0027] A pair of trailing arms 31 connected by an intermediate beam 32 can rotate substantially integrally around a bracket 22 such that the ends 31a move in the vertical direction. The trailing arms 31 are rotatable between a standard position PS and a limit position PF. FIG. 2 shows the trailing arm 31 in the standard position PS by a solid line and the trailing arm 31 in the limit position PF by a two-dot chain line.

[0028] The standard position PS is the position of the trailing arm 31 when there is no occupant on the electric vehicle 10 and no luggage is loaded. That is, the standard position PS is the position of the trailing arm 31 when the rear suspension 13 supports only the weight of the electric vehicle 10.

[0029] The limit position PF is the position of the trailing arm 31 when the electric vehicle 10 accommodates the maximum number of occupants and luggage allowed. The end 31b of the trailing arm 31 in the limit position PF is located above the end 31b of the trailing arm 31 in the standard position PS.

[0030] As shown in FIG. 1, a pair of drive shafts 14 are located behind the intermediate beam 32. The pair of drive shafts 14 are spaced apart rearward from the intermediate beam 32. Each of the pair of drive shafts 14 extends approximately in the left-right direction and is connected to a corresponding rear wheel 12. The drive shaft 14 rotates substantially integrally with the rear wheel 12. Therefore, the drive shaft 14 can drive the rear wheel 12.

[0031] The E-Axle 15 has a motor generator (MG) 41, a transaxle (TA) 42, and a power control unit (PCU) 43. Note that the E-Axle 15 may have other components.

[0032] MG41 is located behind the intermediate beam 32 and behind the drive shaft 14. MG41 is spaced apart rearward from the drive shaft 14 and the intermediate beam 32. Note that a part of MG41 may be at the same position as the drive shaft 14 in the front-rear direction.

[0033] MG41 can function as a motor and a generator. MG41 is, for example, a permanent magnet synchronous motor. Note that MG41 is not limited to this example. MG41 has a rotor 45. Further, MG41 has a stator and other components.

[0034] The rotor 45 has, for example, permanent magnets and an output shaft. MG41 rotates the rotor 45 around the central axis Ax1. The central axis Ax1 extends substantially in the front-rear direction. The central axis Ax1 is the central axis of rotation of the rotor 45 and also the central axis of the output shaft of the rotor 45. Note that the central axis Ax1 may be slightly different from the central axis of the output shaft.

[0035] The central axis Ax1 of rotation of the rotor 45 extends in a direction intersecting the central axis Ax2 of rotation of the drive shaft 14. The central axis Ax2 is the central axis of rotation of the drive shaft 14 and also the central axis of the drive shaft 14. Note that the central axis Ax2 may be slightly different from the central axis of the drive shaft 14.

[0036] The central axis Ax2 of rotation of the drive shaft 14 extends approximately in the left-right direction. In this embodiment, the central axis Ax1 of rotation of the rotor 45 extends in a direction perpendicular to the central axis Ax2 of rotation of the drive shaft 14.

[0037] TA42 has a differential gear (diff) 46. TA42 may further have a transmission and other components. The diff 46 transmits the rotation of the rotor 45 to the drive shaft 14. A plurality of gears included in the diff 46 or other components of TA42 convert the rotation of the rotor 45 around the central axis Ax1 into the rotation of the drive shaft 14 around the central axis Ax2.

[0038] The PCU 43 is attached to, for example, the end face of the MG 41 in the left direction. Therefore, the PCU 43 is aligned with the MG 41 in the vehicle width direction. Note that the position of the PCU 43 is not limited to this example. The PCU 43 controls the drive of the MG 41. For example, the PCU 43 has an inverter and a converter.

[0039] The fuel tank 16 is located in front of the intermediate beam 32. The fuel tank 16 is spaced apart from the intermediate beam 32 in the forward direction. Note that in the front-rear direction, a part of the fuel tank 16 may be at the same position as the intermediate beam 32. For example, a part of the fuel tank 16 may cover a part of the intermediate beam 32 from above.

[0040] The fuel tank 16 stores fuel such as gasoline. Note that when the electric vehicle 10 is a battery electric vehicle, a battery is arranged in front of the intermediate beam 32 instead of the fuel tank 16. Also, when the electric vehicle 10 is a fuel cell electric vehicle, the fuel tank 16 stores hydrogen.

[0041] As shown in FIG. 2, in the vertical direction, at least a part of the intermediate beam 32 is located at the same height as the MG 41. In the present embodiment, in the vertical direction, at least a part of the intermediate beam 32 at the standard position PS is located at the same height as the MG 41, and at least a part of the intermediate beam 32 at the limit position PF is also located at the same height as the MG 41. That is, regardless of the position of the trailing arm 31 within the movable range, in the vertical direction, at least a part of the intermediate beam 32 is located at the same height as the MG 41.

[0042] In other words, in the vertical direction, at least a part of the intermediate beam 32 is arranged at a position overlapping the MG 41. Also, at least a part of the intermediate beam 32 is arranged so as to overlap the MG 41 in the front-rear direction.

[0043] The intermediate beam 32 is positioned between the fuel tank 16 and the MG41. Further, the intermediate beam 32 is positioned between the fuel tank 16 and the drive shaft 14, between the fuel tank 16 and the TA42, and between the fuel tank 16 and the PCU43.

[0044] As shown in FIG. 1, the exhaust pipe 17 extends approximately in the front-rear direction and discharges the exhaust gas emitted from the cylinders of the engine to the outside from the rear end of the electric vehicle 10. The exhaust pipe 17 has a muffler 51.

[0045] The muffler 51 is formed in a box shape to reduce exhaust noise. The muffler 51 is arranged side by side with the MG41 in the vehicle width direction. In this embodiment, the muffler 51 is spaced apart from the MG41 in the right direction. For this reason, the MG41 is positioned between the PCU43 and the muffler 51.

[0046] As shown in FIG. 3, at least a part of the intermediate beam 32 is positioned at the same height as the muffler 51 in the vertical direction. In this embodiment, at least a part of the intermediate beam 32 at the standard position PS is positioned at the same height as the muffler 51 in the vertical direction, and at least a part of the intermediate beam 32 at the limit position PF is also positioned at the same height as the muffler 51. That is, regardless of the position of the trailing arm 31 within the movable range, at least a part of the intermediate beam 32 is positioned at the same height as the muffler 51 in the vertical direction.

[0047] For example, when the electric vehicle 10 is a compact car, the arrangements of the rear suspension 13 and the E-Axle 15 may be restricted. Also, depending on the arrangements of the rear suspension 13 and the E-Axle 15, the size of the luggage compartment of the electric vehicle 10 may be restricted. However, the electric vehicle 10 of this embodiment can eliminate or reduce these restrictions.

[0048] For example, by arranging the MG41 behind the drive shaft 14, the intermediate beam 32 of the rear suspension 13 can be arranged near the rear wheels 12 and the drive shaft 14. Therefore, the layout of the rear suspension 13, which is a de Dion type suspension or a torsion beam type suspension, becomes easier.

[0049] Also, when the MG41 is arranged such that the central axis Ax1 extends substantially in the front-rear direction, the occupied space of the MG41 in the left-right direction becomes smaller. Therefore, it becomes possible to arrange the MG41, the PCU43, and the muffler 51 side by side in the left-right direction in the space behind the drive shaft 14, and the MG41, the PCU43, and the muffler 51 are arranged compactly around the drive shaft 14. As a result, the luggage compartment can be enlarged.

[0050] For example, when the electric vehicle 10 is collided with from behind, the MG41 moves forward. In other words, the MG41 moves toward the fuel tank 16. However, since the intermediate beam 32 is located between the MG41 and the fuel tank 16, the intermediate beam 32 receives the MG41. Similarly, the intermediate beam 32 can receive the drive shaft 14, the TA42, the PCU43, and the muffler 51.

[0051] By receiving the MG41, the intermediate beam 32 suppresses the MG41 from reaching the fuel tank 16. That is, the intermediate beam 32 serves as a wall that protects the fuel tank 16 and can suppress the MG41 from colliding with the fuel tank 16.

[0052] The MG41 may eventually reach the fuel tank 16. However, the MG41 collides with the intermediate beam 32 before reaching the fuel tank 16. Therefore, the kinetic energy of the MG41 is reduced, and the possibility of the MG41 damaging the fuel tank 16 is reduced.

[0053] In the electric vehicle 10 described above, the drive shaft 14 and the MG41 are located behind the intermediate beam 32. On the other hand, the fuel tank 16 is located in front of the intermediate beam 32. Therefore, when the electric vehicle 10 is rear-ended, the intermediate beam 32 can receive the MG41 and prevent the MG41 from reaching the fuel tank 16. Even when the intermediate beam 32 and the MG41 are not at the same height in the vertical direction, since there is a space where the intermediate beam 32 is provided, the distance between the MG41 and the fuel tank 16 becomes longer. From the above, the electric vehicle 10 can prevent the MG41 from damaging the fuel tank 16 when the electric vehicle 10 is rear-ended, and can improve safety.

[0054] In the vertical direction, at least a part of the intermediate beam 32 is located at the same height as the MG41. Therefore, when the electric vehicle 10 is rear-ended, the intermediate beam 32 can more reliably receive the MG41 and prevent the MG41 from damaging the fuel tank 16.

[0055] The PCU43 is arranged side by side with the MG41 in the vehicle width direction. Thereby, the electric vehicle 10 can reduce the size of the E-Axle 15 including the PCU43 and the MG41 in the front-rear direction compared to the case where the PCU43 is arranged in the front-rear direction with the MG41. Therefore, the E-Axle 15 can be mounted on a small vehicle, and the luggage compartment in the electric vehicle 10 can be enlarged. Furthermore, the electric vehicle 10 can reduce the damage received by the PCU43 when the electric vehicle 10 is rear-ended.

[0056] The MG41 and the muffler 51 are arranged side by side in the vehicle width direction. Thereby, the electric vehicle 10 can arrange the components around the drive shaft 14 more compactly in the front-rear direction compared to the case where the MG41 is arranged in the front-rear direction with the muffler 51. Therefore, the degree of freedom in arranging the components in the electric vehicle 10 is improved, and the luggage compartment in the electric vehicle 10 can be enlarged.

[0057] In the above description, "suppress" is defined as, for example, preventing the occurrence of an event, action, or influence, or reducing the degree of an event, action, or influence.

[0058] The embodiments of the present invention have been illustrated above. However, the above embodiments and modified examples are merely examples and are not intended to limit the scope of the invention. The above embodiments and modified examples can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the gist of the invention. Also, the configurations and shapes of each embodiment and each modified example can be partially interchanged and implemented.

Explanation of Reference Numerals

[0059] 10... Electric vehicle, 11... Vehicle body, 12... Rear wheel, 14... Drive shaft, 16... Fuel tank, 17... Exhaust pipe (ExPi), 31... Trailing arm, 32... Intermediate beam, 41... Motor generator (MG), 43... Power control unit (PCU), 45... Rotor, 46... Differential gear (Diff), 51... Muffler, Ax1, Ax2... Central axis.

Claims

1. A pair of trailing arms, each attached to a rear wheel and a vehicle body and spaced apart from each other in the vehicle width direction, an intermediate beam connecting the pair of trailing arms, a drive shaft located behind the intermediate beam and configured to drive the rear wheel, a motor generator having a rotor whose central axis of rotation extends in a direction intersecting the central axis of rotation of the drive shaft, and located behind the drive shaft, a differential gear configured to transmit the rotation of the rotor to the drive shaft, a fuel tank or a battery located in front of the intermediate beam, a muffler for reducing noise, An electric vehicle comprising: The intermediate beam is located between the motor generator and the fuel tank or the battery, The motor generator is arranged such that the central axis of rotation of the rotor extends in the front-rear direction intersecting the vehicle width direction, The muffler is arranged side by side with the motor generator in the vehicle width direction. An electric vehicle.

2. In the vertical direction, at least a part of the intermediate beam is located at the same height as the motor generator, The electric vehicle according to Claim 1.

3. A power control unit for controlling the motor generator, further comprising, The power control unit is arranged side by side with the motor generator in the vehicle width direction, The electric vehicle according to Claim 1.

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