Electric automobile

Abstract

An electric vehicle is provided with: a drive device provided with an electric motor and a speed reducer that transmits rotation generated by the electric motor to a drive shaft; and a steering mechanism that controls a steering angle of the front wheel in accordance with an operation of the steering wheel. The battery is disposed between the driver's seat and the passenger seat across the front and back of the cab. The driving device is of a single-shaft structure and is arranged between the front wheels. The steering mechanism includes a transmission portion, a tie rod, an intermediate shaft, a kingpin, and a suspension arm. The tie rod is connected to the hub frame at a position forward of the kingpin relative to the vehicle. The intermediate shaft connects the steering wheel and the transmission unit through a side surface of the drive device in the vehicle width direction.

Description

Technical Field

[0001] This invention relates to electric vehicles. Background Technology

[0002] An electric vehicle was disclosed in Japanese Patent Application Publication No. 2023-520139. This electric vehicle has a battery located between the driver's seat and the front passenger seat. Summary of the Invention

[0003] [The problem the invention aims to solve]

[0004] There is a demand for sporty electric vehicles. In electric vehicles, to achieve proportions suitable for sports cars, it is desirable to lower the height of the section in front of the driver and front passenger seats, and to lower the seating position within the cabin. In addition, a level of steering feel suitable for sports cars is also desired.

[0005] [Methods used to solve problems]

[0006] The electric vehicle disclosed herein is configured to use electricity stored in a battery to drive the left and right front wheels. It includes: a drive unit comprising an electric motor and a reducer configured to transmit rotation generated by the electric motor to a drive shaft; and a steering mechanism configured to control the steering angle of the front wheels based on steering wheel operation. The battery is distributed between the driver's and passenger's seats, with the reducer and drive shaft arranged along the rotation axis of the electric motor on a single-shaft structure and positioned between the front wheels. The steering mechanism includes: a transmission section located in front of the drive unit, configured to convert steering wheel operation into vehicle-width direction operation; and a steering tie rod. The transmission unit comprises two ends located in the vehicle width direction, connecting the wheel hubs of the front wheels to the transmission unit; an intermediate shaft configured to transmit the steering wheel's movement to the transmission unit; a kingpin serving as the rotation axis of the wheel hubs; and suspension arms connecting the vehicle body to the kingpin. The suspension arms are connected to the vehicle body via multiple bushings, including a front bushing and a rear bushing. The rear bushing is positioned further rearward than the front bushing, and the front bushing has higher rigidity than the rear bushing. The steering tie rod is connected to the wheel hubs at a position further forward than the kingpin. The intermediate shaft passes through the side of the drive unit in the vehicle width direction and connects the steering wheel to the transmission unit. Attached Figure Description

[0007] Figure 1 This is a schematic diagram showing the configuration of the battery and a plurality of devices around an electric vehicle according to one embodiment, viewed from above.

[0008] Figure 2 It means to observe from the side. Figure 1 A schematic diagram of the configuration of the battery and several surrounding devices in an electric vehicle.

[0009] Figure 3 It means Figure 1 A schematic diagram of the drive system of an electric vehicle.

[0010] Figure 4 It means in Figure 1 A schematic diagram illustrating how the steering mechanism is connected to the front wheels in an electric vehicle.

[0011] Figure 5 It means Figure 1 A diagram illustrating the movement of the front wheels of an electric vehicle when making a left turn at high speeds.

[0012] Figure 6 This is a schematic diagram showing the connection between the steering mechanism and the front wheels when the steering tie rod is connected to the wheel hub frame at a position further back than the kingpin.

[0013] Figure 7 It means Figure 1 A diagram showing the positional relationship between the drive unit, intermediate shaft, and transmission unit in an electric vehicle.

[0014] Figure 8 It means Figure 1 A schematic diagram of the configuration of multiple brake discs and multiple brake calipers in an electric vehicle. Detailed Implementation

[0015] The following is for reference Figures 1-8 One implementation method of an electric vehicle is described.

[0016] In the following explanation, terms related to orientation or direction, such as "front," "rear," "up," "down," "right," and "left," are defined based on electric vehicle 100.

[0017] exist Figures 1-6 and Figure 8 In the text, "Fr" indicates the forward direction of the electric vehicle 100. Figures 1-6 and Figure 8 In the text, "Rr" indicates the rear of electric vehicle 100. Figure 1 and Figures 3-7 In the text, "Rh" indicates the right side as viewed from the front of the electric vehicle 100. Figure 1 and Figures 3-7 In the text, "Lh" indicates the left side as viewed from the front of the electric vehicle 100.

[0018] <Configuration of Battery 14 and Drive Unit 20>

[0019] Figure 1 This indicates the configuration of the battery 14 and several surrounding devices when viewed from above in an electric vehicle 100. Figure 2 Indicates from Figure 1 The left side of the image shows the configuration of the battery 14 and several surrounding devices of the electric vehicle 100.

[0020] like Figure 1 As shown, the electric vehicle 100 includes a battery 14. Figure 1 and Figure 2 As shown, the battery 14 is positioned between the driver's seat 12 and the passenger seat 13, distributed around the front and rear of the cab. Multiple battery cells are housed within the battery 14. The battery 14 stores electrical energy within these battery cells.

[0021] like Figure 1 As shown, a drive unit 20 is disposed between the left and right front wheels 10. Figure 1 As shown, in electric vehicle 100, with the center in the vehicle width direction as the reference, in Figure 1 A drive unit 20 is configured on each of the right and left sides of the center. Figure 1 In the middle, the drive unit 20, located on the right side, is connected to the right front wheel of the plurality of front wheels 10 via a drive shaft 21. Figure 1 In the middle, the drive unit 20, located on the left side, is connected to the left front wheel of the plurality of front wheels 10 via a drive shaft 21.

[0022] Figure 3 This shows the structure of the drive unit 20 when viewed from above the electric vehicle 100. Specifically, Figure 3 Indicates in Figure 1 The structure of the drive unit 20 located on the right side. Figure 3 The front wheel 10 shown is the right front wheel.

[0023] like Figure 3 As shown, the drive unit 20 includes a motor 25 and a reducer 26. In the drive unit 20, the motor 25 and the reducer 26 are surrounded by a housing 27.

[0024] like Figure 3 As shown, the reducer 26 includes a sun gear 30, a planetary carrier 33 supporting multiple pinions 31 for rotational movement, and a ring gear 32. The reducer 26 has a planetary gear mechanism.

[0025] like Figure 3 As shown, in the drive unit 20, the motor 25 is connected to the sun gear 30 in the reducer 26. In the reducer 26, a pinion 31, supported on the planetary carrier 33, is positioned between the sun gear 30 and the ring gear 32. The pinion 31 meshes with both the sun gear 30 and the ring gear 32. In the reducer 26, the ring gear 32 is fixed to the housing 27.

[0026] like Figure 3 As shown, a drive shaft 21 is connected to the planetary carrier 33. In the drive unit 20, the rotation generated by the motor 25 is transmitted in the order of the sun gear 30, the planetary carrier 33, and the drive shaft 21. The sun gear 30, pinion 31, and ring gear 32 have different numbers of teeth, therefore the rotation generated by the motor 25 is transmitted to the drive shaft 21 after being reduced in speed. The reducer 26 reduces the rotation generated by the motor 25 before transmitting it to the drive shaft 21.

[0027] Figure 3 The single-dotted line in the diagram represents the rotation axis of motor 25. For example... Figure 3 As shown, in the drive unit 20, the reducer 26 and the drive shaft 21 are arranged on the rotation axis of the motor 25. The rotation axis of the motor 25, the rotation axis of the reducer 26, and the rotation axis of the drive shaft 21 are aligned in a straight line. Therefore, the drive unit 20 has a single-axis structure with a single rotation axis.

[0028] In electric vehicle 100, the front wheels 10 are the drive wheels. For example... Figure 1 and Figure 3 As shown, the drive shaft 21 is connected to the drive unit 20 at one end and to the front wheel 10 at the other end. Figure 1 In the middle, the drive unit 20, located on the right side, rotates the right front wheel via the drive shaft 21. Figure 1 In the middle, the drive unit 20, located on the left side, rotates the left front wheel via the drive shaft 21.

[0029] The electric motor 25 is supplied with the power stored in the battery 14. The electric motor 25 rotates due to the supplied power. The rotation generated by the electric motor 25 is transmitted to the front wheel 10 through the reducer 26 and the drive shaft 21, causing the front wheel 10 to rotate. In this way, the electric vehicle 100 uses the power stored in the battery 14 to drive the front wheel 10.

[0030] Figure 3 The drive unit 20 shown is in Figure 1 The drive unit 20 is located on the right side. Figure 3 In the middle, in the direction from the center of the width of the electric vehicle 100 toward the right, there are arranged in sequence an electric motor 25, a reducer 26, a drive shaft 21, and a front wheel 10.

[0031] Regarding Figure 1 The drive unit 20, electric motor 25, reducer 26, drive shaft 21, and front wheel 10, which are located on the left side, are arranged in the same order as... Figure 3Conversely, the electric motor 25, reducer 26, drive shaft 21, and front wheel 10 are arranged sequentially in the direction from the center of the vehicle width direction of the electric vehicle 100 toward the left. Thus, in the electric vehicle 100, the electric motor 25, reducer 26, drive shaft 21, and front wheel 10 are arranged sequentially in the vehicle width direction.

[0032] like Figure 3 As shown, the drive shaft 21 is connected to the planetary carrier 33 inside the housing 27. Figure 3 As shown, the housing 27 has a central portion 28 and an end portion 29.

[0033] The central section 28 surrounds the electric motor 25 and the reducer 26.

[0034] like Figure 1 As shown, in the housing 27, the end portion 29 is positioned outwards in the vehicle width direction relative to the central portion 28. (As...) Figure 3 As shown, end 29 surrounds the portion of drive shaft 21 connected to reducer 26. (As...) Figure 3 As shown, the drive shaft 21 protrudes from the end 29 of the housing 27 and is connected to the front wheel 10.

[0035] <Structure of Steering Mechanism 41>

[0036] The electric vehicle 100 is equipped with a steering mechanism 41. The steering mechanism 41 controls the turning angle of the front wheels 10 according to the operation of the steering wheel 15.

[0037] The steering mechanism 41 includes a column 16, an intermediate shaft 17, a transmission part 18, and left and right steering tie rods 19.

[0038] like Figure 1 and Figure 2 As shown, the pillar 16 is connected to the steering wheel 15. The pillar 16 fixes the position of the steering wheel 15. The pillar 16 is connected to the intermediate shaft 17. The pillar 16 transmits the movement of the steering wheel 15 to the intermediate shaft 17.

[0039] like Figure 1 and Figure 2 As shown, the intermediate shaft 17 is connected to the column 16 at one end and to the transmission unit 18 at the other end. The intermediate shaft 17 transmits the movement of the steering wheel 15 to the transmission unit 18.

[0040] like Figure 1 and Figure 2 As shown, the transmission unit 18 is positioned in front of the drive unit 20. Figure 2 In the diagram, the dashed line passing through the transmission section 18 indicates the center of the transmission section 18 in the height direction. For example... Figure 2 As shown, the center of the transmission section 18 in the height direction is located below the drive shaft 21. That is, the transmission section 18 is positioned below the drive shaft 21.

[0041] The transmission unit 18 converts the movement of the steering wheel 15 into movement in the vehicle width direction. A rack and pinion gear is provided inside the transmission unit 18. In the transmission unit 18, the pinion gear rotates according to the movement transmitted from the intermediate shaft 17. The rack moves in the vehicle width direction as the pinion gear rotates, thereby converting the movement of the steering wheel 15 into movement in the vehicle width direction.

[0042] Figure 4 The diagram shows the connection between the right front wheel and the steering mechanism 41 when viewed from above in relation to the electric vehicle 100. The connection between the left front wheel and the steering mechanism 41 is such that... Figure 4 A left-right reversal method.

[0043] The left and right front wheels 10 are equipped with wheel hub brackets 34. For example... Figure 1 As shown, the steering tie rod 19 is positioned at both ends of the transmission section 18 in the vehicle width direction. Figure 4 As shown, the steering tie rod 19 connects the wheel hub brackets 34 of the left and right front wheels 10 to the transmission unit 18.

[0044] The steering mechanism 41 has left and right kingpins 35, left and right suspension arms 36 and electric power steering system 42.

[0045] like Figure 4 As shown, the kingpin 35 is mounted on the wheel hub bracket 34. The kingpin 35 is the rotation axis of the wheel hub bracket 34.

[0046] The suspension arm 36 supports the kingpin 35 by connecting the body of the electric vehicle 100 to the kingpin 35. The suspension arm 36 has a V-shape.

[0047] The suspension arm 36 is connected to the vehicle body via multiple bushings 37. For example... Figure 4 As shown, the suspension arm 36 connected to the right front wheel is connected to the vehicle body via two bushings 37 arranged in a longitudinal direction. The two bushings 37 include a front bushing 37A and a rear bushing 37B located further rearward than the front bushing 37A. The front bushing 37A has higher rigidity than the rear bushing 37B.

[0048] like Figure 4 As shown, the steering tie rod 19 is connected to the wheel hub bracket 34 in front of the kingpin 35.

[0049] In the steering mechanism 41, the electric power steering system 42 reduces the force required to operate the steering wheel 15. The electric power steering system 42 includes a power steering motor 22.

[0050] like Figure 1 and Figure 2As shown, the power steering motor 22 is positioned forward of the drive unit 20 and is connected to the transmission unit 18. The power steering motor 22 is driven in conjunction with the movement of the steering wheel 15. The driving force of the power steering motor 22 is transmitted to the transmission unit 18, thereby reducing the force required for steering operation of the steering wheel 15. The power steering motor 22 may also have a mechanism that reduces the rotational speed of the power steering motor 22 before transmitting it to the transmission unit 18.

[0051] The driving force generated by the power steering motor 22 is transmitted to the rack in the rack and pinion of the transmission unit 18. In the electric vehicle 100, a rack-assisted electric power steering system 42 is used.

[0052] <Changes in the steering angle of the front wheel 10 of an electric car 100 while turning>

[0053] Figure 5 and Figure 4 Similarly, the connection between the right front wheel and the steering mechanism 41 when viewed from above in the electric vehicle 100 is also shown. Figure 5 This refers to the way the right front wheel of an electric vehicle 100 turns left in a high-speed region.

[0054] The movement of the steering wheel 15 is transmitted to the transmission unit 18 via the pillar 16 and the intermediate shaft 17. The transmission unit 18 converts the movement of the steering wheel 15 into movement in the vehicle width direction. In this example, the movement of the steering wheel 15 turned to the left is transmitted to the transmission unit 18. The transmission unit 18 converts the movement of the steering wheel 15 turned to the left into... Figure 5 The movement is to the left. At this time, the power steering motor 22 assists in the conversion of the movement caused by the transmission unit 18 by transmitting the driving force to the transmission unit 18.

[0055] The leftward movement output from the transmission unit 18 is transmitted to the wheel hub 34 via the steering tie rod 19. The wheel hub 34, having received the leftward movement, rotates to the left around the kingpin 35. This results in a leftward steering angle at the front wheel 10.

[0056] Thus, the steering angle of the front wheel 10 changes as the steering mechanism 41 transmits the action of the steering wheel 15 to the front wheel 10. When the electric vehicle 100 turns in the high-speed range, in addition to the steering angle change caused by the action of the steering mechanism 41, the steering angle of the front wheel 10 also changes due to the flexible steering caused by the deflection of the bushing 37.

[0057] exist Figure 5 The diagram, represented by a single-dot dashed line, illustrates a specific example of the right front wheel and steering mechanism 41 in a situation where the electric vehicle 100 is turning left at high speed without flexible steering. However, Figure 5The right front wheel and steering mechanism 41 are made to be as shown by the solid line through flexible steering.

[0058] In cornering, especially in vehicles cornering at high speeds, the front wheels 10 grip the ground against centrifugal force. Therefore, the outermost front wheel 10 relative to the cornering center generates a lateral force towards the cornering center. Figure 5 In the example, the electric car 100 turns to the left, thus generating a lateral force in the left direction on the right front wheel.

[0059] The front bushing 37A has higher rigidity than the rear bushing 37B. Therefore, a comparison... Figure 4 and Figure 5 It can be seen that when the front wheel 10 generates a lateral force, the rear bushing 37B deflects more than the front bushing 37A. At this time, the portion of the suspension arm 36 that connects to the vehicle body via the rear bushing 37B moves to the left. Therefore, as... Figure 5 As shown by the solid line, the turning angle of the front wheel 10, located on the outside of the turning center, is less than [missing information]. Figure 5 The corner indicated by the single-dotted line. That is, Figure 5 The front wheel 10 shown by the solid line is relative to Figure 5 The front wheel 10, indicated by the single-dot dash, is in a toe-out state.

[0060] In this way, in a vehicle that is traveling at high speed and turning at the same time, the front wheel 10, which is located on the outside of the turning center, becomes toe-in through flexible steering.

[0061] Figure 6 The connection between the right front wheel and the steering mechanism 41 in the comparative example is shown. In this comparative example, when viewed from above, the steering tie rod 19 is connected to the wheel hub bracket 34 at a position rearward of the kingpin 35. In this case, the transmission unit 18 is located behind the drive unit 20.

[0062] The following are those with Figure 6 The operation of the right front wheel and steering mechanism 41 in a vehicle with the right front wheel and steering mechanism 41 arranged as shown will be explained when turning left at high speeds. When the steering tie rod 19 is connected to the wheel hub bracket 34 at a position rear of the kingpin 35, the steering tie rod 19 will prevent the portion of the suspension arm 36 connected to the vehicle body via the rear bushing 37B from moving to the left. Thus, when the steering tie rod 19 is connected to the wheel hub bracket 34 at a position rear of the kingpin 35, if the steering tie rod 19 has high rigidity, it will prevent the front wheel 10 from becoming toe-in due to soft steering.

[0063] In order to prevent the steering tie rod 19 from hindering the front wheel 10 from becoming toe-in due to flexible steering, it is necessary to reduce the stiffness of the steering tie rod 19.

[0064] In the electric vehicle 100 of this embodiment, the steering tie rod 19 is connected to the wheel hub frame 34 at a position forward of the kingpin 35. Therefore, even if the steering tie rod 19 does not elastically deform, the outer front wheel 10 will still tend to toe in due to the difference in rigidity between the front and rear bushings 37. Thus, when the steering tie rod 19 is connected to the wheel hub frame 34 in front of the kingpin 35, the steering tie rod 19 will not prevent the front wheel 10 from becoming toe-in due to flexible steering. Therefore, compared to the case where the steering tie rod 19 is connected to the wheel hub frame 34 behind the kingpin 35, a steering tie rod 19 with higher rigidity can be provided.

[0065] <Connection method of intermediate shaft 17>

[0066] In the steering mechanism 41, the intermediate shaft 17 connects the steering wheel 15 to the transmission unit 18. Figure 7 This indicates the connection method between the intermediate shaft 17 and the transmission unit 18 when viewing the electric vehicle 100 from the front. Figure 7 The dashed line in the figure indicates the position through which the drive shaft 21 passes. Figure 7 The drive unit 20 is in Figure 1 The drive unit 20 is located on the left side.

[0067] like Figure 1 , Figure 2 , Figure 7 As shown, the intermediate shaft 17 passes through the side of the drive unit 20 in the vehicle width direction and connects the steering wheel 15 to the transmission unit 18. Figure 2 and Figure 7 As shown, the intermediate shaft 17 passes under the drive shaft 21 and connects the steering wheel 15 to the transmission unit 18.

[0068] like Figure 3 and Figure 7 As shown, the housing 27 is configured such that the end 29 is thinner than the central portion 28. (As...) Figure 7 As shown, the intermediate shaft 17 passes through the side of the central part 28 in the vehicle width direction and below the end 29 to connect the steering wheel 15 to the transmission part 18.

[0069] <Brake caliper configuration>

[0070] Figure 8 Indicates from Figure 1 The left side of the image shows the configuration of multiple brake discs and multiple brake calipers 40 in an electric vehicle 100. (Example) Figure 8 As shown, brake calipers 40 are provided on the front wheel 10 and the rear wheel 11 respectively.

[0071] exist Figure 8 In the middle, the single-dot dashed line shown for the front wheel 10 indicates from Figure 1 The image shows the position of the center of the front wheel 10 in the longitudinal direction of the electric vehicle 100 when viewed from the left side. Figure 8 As shown, the brake caliper 40 is positioned further rearward than the dotted line shown for the front wheel 10. That is, the brake caliper 40 located on the front wheel 10 is positioned on the rear side of the front brake disc 38.

[0072] exist Figure 8 In the middle, the single-dot line shown for rear wheel 11 indicates from Figure 1 The left side of the image shows the position of the center of the rear wheel 11 in the longitudinal direction of the electric vehicle 100. (Example:) Figure 8 As shown, the brake caliper 40 is positioned forward of the single-dot line shown for the rear wheel 11. That is, the brake caliper 40 located on the rear wheel 11 is positioned on the front side of the rear brake disc 39.

[0073] <The function of this implementation method>

[0074] In cornering, especially in vehicles cornering at high speeds, if the front wheel 10, located outside the cornering center, exhibits toe-in tendency, the vehicle's handling is more stable relative to steering inputs. When the tie rod 19 is connected to the wheel hub frame 34 further forward than the kingpin 35, increasing the stiffness of the tie rod 19 causes the front wheel 10, located outside the cornering center, toe-in tendency due to the difference in stiffness between the front and rear bushings 37. Conversely, when the tie rod 19 is connected to the wheel hub frame 34 further rear than the kingpin 35, elastic deformation of the tie rod 19 is necessary to induce toe-in tendency in the front wheel 10. That is, the stiffness of the tie rod 19 needs to be reduced to a level that allows the front wheel 10 toe-in tendency. However, if the tie rod 19 has low stiffness, the responsiveness to steering wheel 15 operation decreases, and the steering feel deteriorates.

[0075] A battery 14 is disposed between the driver's seat 12 and the passenger seat 13. As a result, the electric vehicle 100 can lower the seating position compared to the case where the battery 14 is installed under the floor of the driver's seat 12 and the passenger seat 13.

[0076] The drive unit 20 is a single-axle structure, not a dual-axle structure. In the single-axle drive unit 20, the electric motor 25 and the reducer 26 are arranged on a single axis. Compared to the dual-axle drive unit 20, the single-axle drive unit 20 has a larger dimension in the vehicle width direction, but a more compact dimension in the vehicle longitudinal and vertical directions. In order to connect the steering tie rod 19 to the wheel hub frame 34 in front of the kingpin 35, the transmission section 18 needs to be positioned in front of the drive unit 20. The electric vehicle 100 positions the transmission section 18 in the space in front of the drive unit 20, which is freed up due to the single-axle structure.

[0077] <Effects of this implementation method>

[0078] (1) Electric vehicle 100 improves steering feel while maintaining a proportion suitable for sports cars by studying the layout of the equipment.

[0079] (2) The transmission unit 18 is positioned below the drive shaft 21. The intermediate shaft 17 passes under the drive shaft 21 and connects the steering wheel 15 to the transmission unit 18.

[0080] (3) In the vehicle width direction, an electric motor 25, a reducer 26, a drive shaft 21, and a front wheel 10 are arranged sequentially. The electric motor 25 and the reducer 26 are surrounded by a housing 27. The drive shaft 21 is connected to the reducer 26 inside the housing 27. The drive shaft 21 protrudes from the end 29 of the housing 27 in the vehicle width direction and is connected to the front wheel 10. The housing 27 is configured such that the end 29, which is the part surrounding the drive shaft 21, is thinner than the central part 28, which is the part surrounding the electric motor 25 and the reducer 26. An intermediate shaft 17 passes through the side of the central part 28 in the vehicle width direction and below the end 29 to connect the steering wheel 15 to the transmission part 18.

[0081] A space is formed around the end 29 surrounding the drive shaft 21. The intermediate shaft 17 is configured to pass through the space around the end 29. As a result, the intermediate shaft 17 can be shortened as much as possible, thus achieving improved steering feel and vehicle weight reduction.

[0082] (4) Brake calipers 40 are provided on the front wheel 10 and the rear wheel 11 respectively. The brake caliper 40 provided on the front wheel 10 is located on the rear side of the front brake disc 38. The brake caliper 40 provided on the rear wheel 11 is located on the front side of the rear brake disc 39.

[0083] When the brake caliper 40 is located outside the region between the rotation axis of the front wheel 10 and the rotation axis of the rear wheel 11 of the electric vehicle 100, the brake caliper 40 is away from the center of gravity of the electric vehicle 100. Compared to a situation where multiple devices are mounted in a position away from the center of gravity and the mass is distributed in that position, the electric vehicle 100 exhibits higher cornering responsiveness when multiple devices are mounted in a position close to the center of gravity and the mass is concentrated in that position. In this embodiment, by distributing multiple brake calipers 40 between the rotation axis of the front wheel 10 and the rotation axis of the rear wheel 11, the multiple brake calipers 40 are positioned close to the center of gravity of the electric vehicle 100. As a result, the electric vehicle 100 can achieve improved cornering responsiveness.

[0084] (5) The steering mechanism 41 is equipped with an electric power steering system 42 that reduces the force required for steering operation of the steering wheel 15. The electric power steering system 42 is equipped with a power steering motor 22 that is driven according to the movement of the steering wheel 15. The power steering motor 22 is positioned forward of the drive unit 20 and is connected to the transmission unit 18.

[0085] A power steering motor 22 is installed in the transmission section 18. The power steering motor 22 is positioned in the space in front of the drive unit 20, which is freed up due to the single-shaft structure. Thus, the electric vehicle 100 can maintain a proportion suitable for a sports car while simultaneously possessing a power steering motor 22.

[0086] <Example of Change>

[0087] This embodiment can be implemented by modification as follows. This embodiment and the following modifications can be combined with each other within the scope of technical inconsistency.

[0088] The aforementioned electric vehicles 100, such as Figure 1 As shown, the driver's seat 12 is configured in Figure 1 On the left, the passenger seat 13 is located at Figure 1 On the right side. The configuration of the driver's seat 12 and the front passenger seat 13 can also be reversed.

[0089] In this case, the position of the steering wheel 15 is opposite to the center of the electric vehicle 100 in the width direction. Therefore, the positions of the pillar 16 and the intermediate shaft 17 are also opposite to the center of the electric vehicle 100 in the width direction.

[0090] In the aforementioned electric vehicle 100, the intermediate shaft 17 passes through... Figure 1 The intermediate shaft 17 passes through the center portion 28 of the left-hand drive unit 20 and below the end portion 29. In the case where the driver's seat 12 and the front passenger seat 13 are configured oppositely, the intermediate shaft 17 passes through... Figure 1The steering wheel 15 is connected to the transmission unit 18 by being located on the side of the central part 28 and below the end 29 of the drive unit 20 on the right side.

[0091] In the electric vehicle 100 described above, the front wheels 10 are the drive wheels. The electric vehicle 100 can also be a four-wheel drive vehicle that drives the rear wheels 11 in addition to the front wheels 10.

[0092] In the electric vehicle 100 described above, the transmission unit 18 is positioned below the drive shaft 21. The position of the transmission unit 18 in the electric vehicle 100 is not limited to the embodiment described above. For example, the transmission unit 18 may also be positioned above the drive shaft 21.

[0093] In the electric vehicle 100 described above, the intermediate shaft 17 passes under the drive shaft 21 and connects the steering wheel 15 to the transmission unit 18. The intermediate shaft 17 in the electric vehicle 100 is not limited to the embodiment described above. For example, the intermediate shaft 17 may also pass over the drive shaft 21 and connect the steering wheel 15 to the transmission unit 18.

[0094] In the electric vehicle 100 described above, the intermediate shaft 17 passes through the side of the central portion 28 and below the end portion 29 to connect the steering wheel 15 to the transmission unit 18. The intermediate shaft 17 in the electric vehicle 100 is not limited to the embodiment described above. For example, the intermediate shaft 17 may also pass through the side of the end portion 29 to connect the steering wheel 15 to the transmission unit 18. For example, the intermediate shaft 17 may also pass through the side of the central portion 28 and above the end portion 29 to connect the steering wheel 15 to the transmission unit 18.

[0095] In the electric vehicle 100 described above, the housing 27 of the drive unit 20 has a central portion 28 and an end portion 29 that is thinner than the central portion 28. The housing 27 of the electric vehicle 100 is not limited to the embodiment described above. For example, in the housing 27, the end portion 29 may be configured to have the same thickness as the central portion 28 or be thicker than the central portion 28.

[0096] In the aforementioned electric vehicle 100, in Figure 1 In both the right-side and left-side drive units 20, the end portion 29 is made thinner than the central portion 28. In the right-side drive unit 20 where the intermediate shaft 17 does not pass through, the end portion 29 does not need to be made thinner than the central portion 28.

[0097] In the electric vehicle 100 described above, the drive shaft 21 is connected to the reducer 26 inside the housing 27 and protrudes from the end 29 to connect to the front wheel 10. Alternatively, the reducer 26 may protrude from the housing 27, and the reducer 26 and drive shaft 21 may be connected outside the housing 27. In this case, the end 29 does not surround the drive shaft 21.

[0098] The steering mechanism 41 in the electric vehicle 100 described above is equipped with an electric power steering system 42. Alternatively, the steering mechanism 41 in the electric vehicle 100 may not employ an electric power steering system 42, serving as a power steering system that reduces the force required to operate the steering wheel 15.

[0099] For example, the electric vehicle 100 may also have a hydraulic power steering system. Alternatively, the electric vehicle 100 may also have an electro-hydraulic power steering system. If the electric vehicle 100 does not use the electric power steering system 42 as its power steering system, it may also not have a power steering motor 22. For example, the electric vehicle 100 may also not have a power steering system.

[0100] In the electric vehicle 100 described above, the power steering motor 22 is positioned forward of the drive unit 20 and is connected to the transmission unit 18. The position of the power steering motor 22 in the electric vehicle 100 is not limited to the embodiment described above. In the electric vehicle 100, the power steering motor 22 may also be positioned rearward of the drive unit 20.

[0101] In the electric vehicle 100 described above, the electric vehicle 100 employs a rack-and-pinion assisted electric power steering system 42. The location of the power steering motor 22 and the structure of the electric power steering system 42 in the electric vehicle 100 are not limited to the embodiments described above.

[0102] For example, the electric vehicle 100 may also employ a pillar-assisted electric power steering system 42. In this case, the power steering motor 22 is connected to the pillar 16 and transmits driving force to the pillar 16.

[0103] For example, the electric vehicle 100 may also employ a pinion-assisted electric power steering system 42. In this case, the power steering motor 22 is connected to the pinion in the rack and pinion of the transmission unit 18, and the driving force is transmitted to the pinion.

[0104] The steering mechanism 41 in the electric vehicle 100 described above has a rack and pinion pair in the transmission section 18. On the other hand, the steering mechanism 41 in the electric vehicle 100 may also not have a rack and pinion pair in the transmission section 18. For example, the steering mechanism 41 may also have a ball nut type mechanism in the transmission section 18.

[0105] In electric vehicle 100, the connection method between suspension arm 36 and the vehicle body is not limited to... Figure 4 The manner shown. That is, the number and position of the bushings 37 configured in the electric vehicle 100 are not limited to those shown. Figure 4 As shown in the diagram.

[0106] The electric vehicle 100 described above includes two drive units 20: one connected to the right front wheel and the other connected to the left front wheel. The drive units 20 provided in the electric vehicle 100 are not limited to the embodiments described above.

[0107] For example, the electric vehicle 100 may not have two drive units 20, but instead has one drive unit 20 connected to both the right front wheel and the left front wheel. Hereinafter, the electric vehicle 100 adopting this method will be referred to as the first modified electric vehicle 100.

[0108] For example, in the electric vehicle 100, a drive shaft 21 may be configured such that it is connected to the rotation axis of the electric motor 25 provided in the left and right drive units 20 respectively. Hereinafter, the electric vehicle 100 adopting this configuration will be referred to as the electric vehicle 100 of the second modified example.

[0109] The structure of the drive unit 20 in the electric vehicle 100 is not limited to... Figure 3 As shown. For example, in the drive unit 20 of the electric vehicle 100 in the first and second modifications, in addition to the electric motor 25 and the reducer 26, a differential gear may also be provided.

[0110] • In the electric vehicle 100, the location of the brake caliper 40 is not limited to the above-described embodiments.

[0111] The brake caliper 40 located on the front wheel 10 can also be located on the front side of the front brake disc 38.

[0112] The brake caliper 40 located on the rear wheel 11 can also be located on the rear side of the rear brake disc 39.

Claims

1. An electric vehicle configured to use electricity stored in a battery to drive the left and right front wheels, comprising: The drive unit includes an electric motor and a reducer, the reducer being configured to transmit rotation generated by the electric motor to the drive shaft; and The steering mechanism is configured to control the steering angle of the front wheels based on the operation of the steering wheel. The batteries are distributed throughout the cab, between the driver's seat and the passenger seat. The drive unit has a single-shaft structure in which the reducer and the drive shaft are arranged on the rotation axis of the electric motor and are positioned between the front wheels. The steering mechanism has: A transmission unit is disposed in front of the drive device and configured to convert the steering wheel movement into movement in the vehicle width direction; Steering tie rods, disposed at both ends of the transmission unit in the vehicle width direction, connect the wheel hubs of the front wheels to the transmission unit; and The intermediate shaft is configured to transmit the steering wheel's motion to the transmission unit; Kingpin, serving as the rotation axis of the hub bracket; and The suspension arms connect the vehicle body to the kingpin. The suspension arms are connected to the vehicle body via multiple bushings. The plurality of bushings includes a front bushing and a rear bushing, the rear bushing being positioned further rearward than the front bushing, and the front bushing having higher rigidity than the rear bushing. The steering tie rod is connected to the wheel hub bracket at a position forward of the kingpin. The intermediate shaft passes through the side of the drive unit in the vehicle width direction and connects the steering wheel to the transmission unit.

2. The electric vehicle according to claim 1, wherein, The transmission unit is positioned below the drive shaft. The intermediate shaft passes under the drive shaft and connects the steering wheel to the transmission unit.

3. The electric vehicle according to claim 2, wherein, In the vehicle width direction, the electric motor, the reducer, the drive shaft, and one of the front wheels are arranged in sequence. The electric motor and the reducer are enclosed in a housing. The drive shaft is connected to the reducer inside the housing and protrudes from the end of the housing in the vehicle width direction to connect to one of the front wheels. The housing is configured such that the end portion surrounding the drive shaft is thinner than the central portion surrounding the motor and the reducer. The intermediate shaft passes through the side of the central part in the vehicle width direction and below the end to connect the steering wheel to the transmission part.

4. The electric vehicle according to any one of claims 1 to 3, wherein, Brake calipers are installed on both the front and rear wheels. The brake caliper, located on the front wheel, is positioned on the rear side of the front brake disc. The brake caliper located on the rear wheel is positioned on the front side of the rear brake disc.

5. The electric vehicle according to any one of claims 1 to 3, wherein, The steering mechanism includes an electric power steering system configured to reduce the force required to operate the steering wheel. The electric power steering system includes a power steering motor configured to drive the steering wheel according to its movement. The power steering motor is positioned forward of the drive unit and is connected to the transmission unit.

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