Electric vehicle

Abstract

To provide an electric vehicle that can improve steering feel, while maintaining a proportion like a sports car.SOLUTION: An electric vehicle 100 is provided with: a driving device 20 that is provided with a motor and a speed reducer that transmits rotation by the motor to a drive shaft 21; and a steering mechanism that controls steering angles of front wheels 10 in accordance with operation of a steering wheel 15. A battery 14 is arranged across a front side and a rear side of a cabin, between a driver's seat 12 and a front passenger seat 13. The driving device 20 has a uniaxial structure and is arranged between the front wheels 10. The steering mechanism comprises a transmitting part 18, a tie-rod 19, an intermediate shaft 17, a king-pin, and a suspension arm. The tie-rod 19 is connected to a hub carrier, at a side closer to a front side of a vehicle than the king-pin. The intermediate shaft 17 connects the steering wheel 15 to the transmitting part 18 through a side surface of the driving de vice 20 in a vehicle width direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to electric vehicles. [Background technology]

[0002] Patent Document 1 discloses an electric vehicle in which a battery is disposed between the driver's seat and the passenger seat. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-520139 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for sports-type electric vehicles. In order to achieve the proportions of a sports car in an electric vehicle, it is desirable to lower the vehicle height in front of the driver's seat and passenger seat, and to lower the seating position inside the vehicle. There is also a demand for good steering feel, which is characteristic of a sports car. [Means for solving the problem]

[0005] An electric vehicle that solves the above problems drives the front wheels using electricity stored in a battery. The electric vehicle is equipped with a drive unit including a motor and a reducer that transmits rotation by the motor to a drive shaft. The electric vehicle is equipped with a steering mechanism that controls the turning angle of the front wheels in response to steering wheel operation. In the electric vehicle, the battery is located between the driver's seat and the passenger seat, spanning the front and rear of the cabin. In the electric vehicle, the drive unit has a uniaxial structure in which the reducer and the drive shaft are arranged on an extension of the rotation shaft of the motor, and is arranged between the front wheels. In the electric vehicle, the steering mechanism is located in front of the drive unit and includes a transmission unit that converts movement of the steering wheel into movement in the vehicle width direction. In the electric vehicle, the steering mechanism is located at both ends of the transmission unit in the vehicle width direction and includes tie rods that connect the transmission unit to hub carriers provided on the left and right front wheels. In the electric vehicle, the steering mechanism includes an intermediate shaft that transmits movement of the steering wheel to the transmission unit. In an electric vehicle, the steering mechanism includes a kingpin that is a rotation axis of the hub carrier. In an electric vehicle, the steering mechanism includes a suspension arm that connects the vehicle body and the kingpin. In an electric vehicle, the suspension arm is connected to the vehicle body via a plurality of bushes. In an electric vehicle, of the plurality of bushes, the bushes arranged at the front of the vehicle have higher rigidity than the bushes arranged at the rear of the vehicle. In an electric vehicle, the tie rod is connected to the hub carrier further forward of the kingpin. In an electric vehicle, the intermediate shaft passes through a side of the drive unit in the vehicle width direction and connects the steering wheel and the transmission unit. [Effects of the Invention]

[0006] The electric vehicle mentioned above has an improved steering feel while maintaining the proportions of a sports car through an ingenious layout of its equipment. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing the arrangement of a battery and its peripheral devices when viewed from above an electric vehicle according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the arrangement of the battery and its peripheral devices when the electric vehicle according to the embodiment is viewed from the side. [Figure 3] FIG. 3 is a schematic diagram showing a drive unit provided in the electric vehicle according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram showing a state in which the steering mechanism and the front wheels are connected in the electric vehicle according to the embodiment. [Figure 5] FIG. 5 is a schematic diagram showing the state of the front wheels when the electric vehicle of the embodiment is turning left at a high speed. [Figure 6] FIG. 6 is a schematic diagram showing a state of connection between the steering mechanism and the front wheels when the tie rod is connected to the hub carrier at a position rearward of the kingpin on the vehicle. [Figure 7] FIG. 7 is a diagram showing the positional relationship between the drive unit, the intermediate shaft, and the transmission unit in the electric vehicle of the embodiment. [Figure 8] FIG. 8 is a schematic diagram showing the arrangement of brake discs and brake calipers provided in the electric vehicle of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the electric vehicle will be described below with reference to FIGS. Note that directions are indicated by arrows in Figs. 1 to 8. In Figs. 1 to 6 and 8, Fr indicates the forward direction of the electric vehicle 100. In Figs. 1 to 6 and 8, Rr indicates the rearward direction of the electric vehicle 100. In Figs. 1 and 3 to 7, Rh indicates the right side as seen by a passenger facing forward in the electric vehicle 100. In Figs. 1 and 3 to 7, Lh indicates the left side as seen by a passenger facing forward in the electric vehicle 100.

[0009] <Arrangement of Battery 14 and Drive Device 20> Fig. 1 shows the arrangement of the battery 14 and its peripheral devices when the electric vehicle 100 is viewed from above. Fig. 2 shows the arrangement of the battery 14 and its peripheral devices when the electric vehicle 100 is viewed from the direction Lh in Fig. 1.

[0010] As shown in Fig. 1, the electric vehicle 100 includes a battery 14. As shown in Figs. 1 and 2, the battery 14 is disposed across the front and rear of the cabin between a driver's seat 12 and a passenger seat 13. The battery 14 contains a plurality of battery cells. The battery 14 stores electricity in the battery cells.

[0011] As shown in Fig. 1, a drive unit 20 is disposed between the left and right front wheels 10. As shown in Fig. 1, in the electric vehicle 100, one drive unit 20 is disposed on each of the Rh side and Lh side in Fig. 1. In Fig. 1, the drive unit 20 disposed on the Rh side is connected to the right front wheel of the front wheels 10 via a drive shaft 21. In Fig. 1, the drive unit 20 disposed on the Lh side is connected to the left front wheel of the front wheels 10 via a drive shaft 21.

[0012] Fig. 3 shows the configuration of the drive unit 20 when the electric vehicle 100 is viewed from above. Specifically, Fig. 3 shows the configuration of the drive unit 20 disposed on the Rh side in Fig. 1. Therefore, the front wheel 10 shown in Fig. 3 is the right front wheel.

[0013] 3, the driving device 20 includes a motor 25 and a reducer 26. In the driving device 20, the motor 25 and the reducer 26 are enclosed in a housing 27.

[0014] 3, the reducer 26 includes a sun gear 30, a planetary carrier 33 that rotatably supports a plurality of pinion gears 31, and a ring gear 32. In other words, the reducer 26 includes a planetary gear mechanism.

[0015] As shown in Fig. 3, in the drive unit 20, the motor 25 is connected to a sun gear 30 in the reducer 26. In the reducer 26, a pinion gear 31 supported by a planetary carrier 33 is disposed between the sun gear 30 and a ring gear 32. The pinion gear 31 meshes with both the sun gear 30 and the ring gear 32. In the reducer 26, the ring gear 32 is fixed to a housing 27.

[0016] As shown in Fig. 3, the planetary carrier 33 is connected to the drive shaft 21. In the drive device 20, the rotation generated by the motor 25 is transmitted in this order to the sun gear 30, the planetary carrier 33, and the drive shaft 21. At this time, due to the difference in the number of teeth of the sun gear 30, the pinion gear 31, and the ring gear 32, the rotation generated by the motor 25 is decelerated before being transmitted to the drive shaft 21. In this way, the reducer 26 decelerates the rotation of the motor 25 before transmitting it to the drive shaft 21.

[0017] The dashed line in Fig. 3 indicates the rotation axis of the rotation generated by the motor 25. As shown in Fig. 3, in the driving device 20, the speed reducer 26 and the drive shaft 21 are disposed on an extension of the rotation axis of the motor 25. In other words, the driving device 20 has a uniaxial structure in which the rotation axis of the motor 25, the rotation axis of the speed reducer 26, and the rotation axis of the drive shaft 21 are aligned on a single straight line, aligning the rotation axes into one.

[0018] As shown in FIGS. 1 and 3, the drive shaft 21 is connected at one end to the drive unit 20 and at the other end to the front wheels 10. As described above, one drive unit 20 is disposed on each of the Rh and Lh sides in FIG. 1. In FIG. 1, the drive unit 20 disposed on the Rh side rotates the right front wheel through the drive shaft 21. In addition, in FIG. 1, the drive unit 20 disposed on the Lh side rotates the left front wheel through the drive shaft 21. Thus, in the electric vehicle 100, the front wheels 10 are drive wheels.

[0019] Electricity stored in the battery 14 is supplied to the motor 25. The motor 25 generates rotation using the supplied electricity. The rotation generated by the motor 25 is then transmitted to the front wheels 10 via the reducer 26 and the drive shaft 21, causing the front wheels 10 to rotate. In this way, the electric vehicle 100 drives the front wheels 10, which are the drive wheels, using the electricity stored in the battery 14.

[0020] As described above, the drive unit 20 shown in Fig. 3 is the drive unit 20 arranged on the Rh side in Fig. 1. In Fig. 3, which shows the drive unit 20 arranged on the Rh side, the motor 25, the reducer 26, the drive shaft 21, and the front wheels 10 are arranged in this order in the direction from the center of the vehicle toward the Rh side.

[0021] 1, the order in which the motor 25, the reducer 26, the drive shaft 21, and the front wheels 10 are arranged is the opposite of that in FIG. 3. That is, in the direction from the center of the vehicle toward Lh, the order is motor 25, reducer 26, drive shaft 21, and front wheels 10. In this way, in the electric vehicle 100, the order is motor 25, reducer 26, drive shaft 21, and front wheels 10 in the vehicle width direction.

[0022] 3, the drive shaft 21 is connected to a planetary carrier 33 inside the housing 27. Also, as shown in FIG. 3, the housing 27 is made up of a center portion 28 and end portions 29.

[0023] The central portion 28 is a portion that surrounds the motor 25 and the reducer 26 . As shown in Fig. 1, end portion 29 of housing 27 is located on the outer side of the vehicle in the vehicle width direction. As shown in Fig. 3, end portion 29 of housing 27 is a portion that surrounds drive shaft 21 connected to speed reducer 26. As shown in Fig. 3, drive shaft 21 protrudes from end portion 29 of housing 27 and is connected to front wheel 10.

[0024] <Configuration of steering mechanism> The electric vehicle 100 is equipped with a steering mechanism that controls the turning angle of the front wheels 10 in response to the operation of the steering wheel 15.

[0025] The steering mechanism includes, as components, a column 16, an intermediate shaft 17, a transmission unit 18, and a tie rod 19. As shown in Figures 1 and 2, the column 16 is connected to the handle 15. The column 16 fixes the position of the handle 15. The column 16 is also connected to an intermediate shaft 17. The column 16 has the role of transmitting the movement of the handle 15 to the intermediate shaft 17.

[0026] 1 and 2, the intermediate shaft 17 is connected at one end to the column 16 and at the other end to the transmission unit 18. The intermediate shaft 17 has a role of transmitting the movement of the handle 15 to the transmission unit 18.

[0027] 1 and 2, the transmission unit 18 is disposed in front of the drive unit 20. In FIG. 2, the dashed line shown on the transmission unit 18 indicates the center of the transmission unit 18 in the height direction. As shown in FIG. 2, the center of the transmission unit 18 in the height direction is lower than the drive shaft 21. In other words, the transmission unit 18 is disposed lower than the drive shaft 21.

[0028] 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 in response to the movement transmitted from the intermediate shaft 17, and the rack moves in the vehicle width direction in response to the rotation of the pinion gear, thereby converting the movement of the steering wheel 15 into movement in the vehicle width direction.

[0029] 4 shows the connection between the right front wheel and the steering mechanism when viewed from above the electric vehicle 100. The connection between the left front wheel and the steering mechanism is shown by flipping FIG.

[0030] The left and right front wheels 10 are equipped with hub carriers 34. As shown in Fig. 1, tie rods 19 are disposed on both ends of the transmission unit 18 in the vehicle width direction. As shown in Fig. 4, the tie rods 19 connect the hub carriers 34 equipped on the left and right front wheels 10 to the transmission unit 18.

[0031] In addition to the above components, the steering mechanism includes a kingpin 35, a suspension arm 36, and an electric power steering system. 4, the kingpin 35 is installed on the hub carrier 34. The kingpin 35 is the axis around which the hub carrier 34 rotates.

[0032] 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 is connected to the vehicle body via a plurality of bushes 37. As shown in Fig. 4, in this embodiment, the suspension arm 36 connected to the right front wheel is connected to the vehicle body via two bushes 37 arranged in the front-to-rear direction of the vehicle. Of the two bushes 37, the bush 37 arranged at the front of the vehicle has higher rigidity than the bush 37 arranged at the rear of the vehicle.

[0033] As shown in FIG. 4, the tie rod 19 is connected to the hub carrier 34 at a position forward of the kingpin 35 in the vehicle. In the steering mechanism, the electric power steering system reduces the force required to steer the steering wheel 15. The electric power steering system includes a power steering motor 22.

[0034] 1 and 2, the power steering motor 22 is disposed further forward in the vehicle than the drive unit 20, and is connected to the transmission unit 18. The power steering motor 22 is driven in accordance 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 to steer the steering wheel 15. The power steering motor 22 may be provided with a mechanism that reduces the speed of the rotation of the power steering motor 22 before transmitting it to the transmission unit 18.

[0035] In this embodiment, the driving force from the power steering motor 22 is transmitted to a rack in a rack-and-pinion gear provided in the transmission unit 18. In other words, the electric vehicle 100 employs a rack-assist type electric power steering system.

[0036] <Change in Turning Angle of Front Wheels 10 in Electric Vehicle 100 During Turning> Similar to Fig. 4, Fig. 5 shows the state of connection between the right front wheel and the steering mechanism when the electric vehicle 100 is viewed from above. Fig. 5 shows the state of the right front wheel when the electric vehicle 100 is turning left at a high speed.

[0037] As described above, the movement of the steering wheel 15 is transmitted to the transmission unit 18 via the column 16 and the intermediate shaft 17. The transmission unit 18 then 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 then converts the movement of the steering wheel 15 turned to the left into movement in the Lh direction in FIG. 5. At this time, the power steering motor 22 transmits driving force to the transmission unit 18, thereby assisting the transmission unit 18 in converting the movement into movement in the Lh direction.

[0038] The movement in the Lh direction output by the transmission unit 18 is transmitted to the hub carrier 34 via the tie rod 19. The hub carrier 34, to which the movement in the Lh direction is transmitted, rotates in the Lh direction around the kingpin 35 as the rotation axis. As a result, a turning angle in the Lh direction is generated in the front wheel 10.

[0039] In this way, the turning angle of the front wheels 10 changes as the steering mechanism transmits the movement of the steering wheel 15. When the electric vehicle 100 is turning at high speeds, in addition to the change in turning angle due to the action of the steering mechanism, the turning angle of the front wheels 10 also changes due to compliance steer caused by the bending of the bushing 37.

[0040] The dashed-dotted line in Fig. 5 shows a specific example of the state of the right front wheel and steering mechanism in the absence of compliance steering when electric vehicle 100 is turning left at high speed. In other words, the right front wheel and steering mechanism in Fig. 5 would have been in the state shown by the dashed-dotted line in response to the movement of steering wheel 15, but are now in the state shown by the solid line due to compliance steering.

[0041] When a vehicle is turning, particularly at high speeds, the front wheels 10 grip the ground against centrifugal force, causing a lateral force to be generated on the outer front wheel 10 in a direction toward the center of the turn, i.e., toward the inside of the vehicle. In the example of Figure 5, the electric vehicle 100 is turning left, so a lateral force is generated on the right front wheel in the direction of Lh.

[0042] As described above, of the two bushes 37, the bush 37 disposed at the front of the vehicle has higher rigidity than the bush 37 disposed at the rear of the vehicle. Therefore, as can be seen by comparing Figures 4 and 5, when a lateral force is applied to the front wheel 10, the bush 37 disposed at the rear of the vehicle bends more than the bush 37 disposed at the front of the vehicle. At this time, the portion of the suspension arm 36 that is connected to the vehicle body by the bush 37 disposed at the rear of the vehicle moves in the Lh direction. As a result, the outer front wheel 10 toes out as shown by the solid line in Figure 5, rather than the turning angle corresponding to the movement of the handlebars 15 as shown by the dashed line in Figure 5.

[0043] In this way, when a vehicle is turning while traveling at a high speed, the outer front wheel 10 will toe out due to compliance steer. 6 shows, as a comparative example, a state of connection between the right front wheel and the steering mechanism when the tie rod 19 is connected to the hub carrier 34 rearward of the kingpin 35 when viewed from above the vehicle. In this case, the transmission unit 18 is disposed rearward of the drive unit 20.

[0044] Consider a case where a vehicle equipped with a right front wheel and steering mechanism connected as shown in Figure 6 turns left at high speeds, as in Figure 5. If the tie rod 19 is connected to the hub carrier 34 rearward of the kingpin 35, the tie rod 19 will inhibit movement in the Lh direction of the portion of the suspension arm 36 that is connected to the vehicle body by a bushing 37 disposed rearward of the vehicle. In other words, if the tie rod 19 is connected to the hub carrier 34 rearward of the kingpin 35, and the tie rod 19 has high rigidity, the tie rod 19 will inhibit toe-out of the front wheel 10 due to compliance steer.

[0045] In order to prevent the tie rod 19 from interfering with the toe-out caused by compliance steering of the front wheels 10 when the tie rod 19 is connected to the hub carrier 34 behind the kingpin 35 of the vehicle, the rigidity of the tie rod 19 needs to be reduced.

[0046] As described above, in the electric vehicle 100 of this embodiment, the tie rod 19 is connected to the hub carrier 34 further forward than the kingpin 35. When the tie rod 19 is connected to the hub carrier 34 further forward than the kingpin 35, the outer front wheel 10 will be toe-out even if the tie rod 19 does not elastically deform due to the difference in rigidity between the bushings 37 at the front and rear of the vehicle. In this way, when the tie rod 19 is connected to the hub carrier 34 further forward than the kingpin 35, the tie rod 19 does not hinder the toe-out of the front wheels 10 due to compliance steering. In other words, when the front wheels 10 are toe-out due to compliance steering, if the tie rod 19 is connected to the hub carrier 34 further forward than the kingpin 35, a tie rod 19 with higher rigidity can be installed than if it is connected at the rear of the vehicle.

[0047] <Connection of the intermediate shaft 17> In the steering mechanism, intermediate shaft 17 connects handle 15 and transmission unit 18. Fig. 7 shows the connection between intermediate shaft 17 and transmission unit 18 when electric vehicle 100 is viewed from the front of the vehicle. The dotted line in Fig. 7 indicates the position where drive shaft 21 passes. Furthermore, drive unit 20 in Fig. 7 is the drive unit 20 arranged on the Lh side in Fig. 1.

[0048] 1, 2, and 7, the intermediate shaft 17 passes through the side of the drive unit 20 in the vehicle width direction to connect the handle 15 and the transmission unit 18. Also, as shown in FIGS. 2 and 7, the intermediate shaft 17 passes below the drive shaft 21 to connect the handle 15 and the transmission unit 18.

[0049] 3 and 7, the housing 27 is configured so that the end portions 29 are thinner than the central portion 28. As shown in Fig. 7, the intermediate shaft 17 passes along the side of the central portion 28 in the vehicle width direction and below the end portions 29, connecting the handlebars 15 and the transmission unit 18.

[0050] <40 brake caliper placement> Fig. 8 shows the arrangement of brake discs and brake calipers 40 when the electric vehicle 100 is viewed from the direction Lh in Fig. 1. As shown in Fig. 8, the brake calipers 40 are installed on the front wheels 10 and the rear wheels 11.

[0051] In Fig. 8, the dashed dotted line shown on the front wheel 10 indicates the position of the center of the front wheel 10 in the vehicle longitudinal direction when the electric vehicle 100 is viewed from the direction Lh in Fig. 1. As shown in Fig. 8, the brake caliper 40 is disposed rearward of the dashed dotted line shown on the front wheel 10. In other words, the brake caliper 40 installed on the front wheel 10 is disposed on the vehicle rear side of the front brake disc 38.

[0052] In Fig. 8, the dashed dotted line shown on the rear wheel 11 indicates the position of the center of the rear wheel 11 in the vehicle front-rear direction when the electric vehicle 100 is viewed from the direction Lh in Fig. 1. As shown in Fig. 8, the brake caliper 40 is disposed forward of the dashed dotted line shown on the rear wheel 11. In other words, the brake caliper 40 installed on the rear wheel 11 is disposed on the vehicle front side of the rear brake disc 39.

[0053] <Operation of this embodiment> When a vehicle is turning, particularly at high speeds, the vehicle's behavior in response to steering operation is stabilized if the outside front wheel 10 is toe-out. If the tie rod 19 is connected to the hub carrier 34 further forward of the kingpin 35, the difference in rigidity between the front and rear bushings 37 will cause the outside front wheel 10 to toe out if the rigidity of the tie rod 19 is high. On the other hand, if the tie rod 19 is connected to the hub carrier 34 further rearward of the kingpin 35, the tie rod 19 must be elastically deformed to toe out the outside front wheel 10. In other words, if the tie rod 19 is connected to the rear side of the hub carrier 34, the rigidity of the tie rod 19 must be low enough to allow the outside front wheel 10 to toe out when the vehicle is turning. However, if the rigidity of the tie rod 19 is low, responsiveness to steering wheel 15 operation will be reduced, resulting in a poor steering feel.

[0054] In the electric vehicle 100 described above, the battery 14 is disposed between the driver's seat 12 and the passenger's seat 13. This allows the seating position to be lower than when the battery 14 is mounted under the floor of the driver's seat 12 and the passenger's seat 13.

[0055] In this electric vehicle 100, the drive unit 20 has a single-shaft structure rather than a double-shaft structure. In the single-shaft structure drive unit 20, the motor 25 and the reducer 26 are aligned in the direction of axis extension. Although the single-shaft structure drive unit 20 is larger in the vehicle width direction than the double-shaft structure drive unit 20, the dimensions in the vehicle front-to-rear and vehicle up-and-down directions are more compact. In order for the tie rod 19 to connect to the hub carrier 34 further forward of the kingpin 35, the transmission unit 18 needs to be located forward of the drive unit 20. In the electric vehicle 100 described above, the transmission unit 18 is located in the space in front of the drive unit 20 that is freed up by the single-shaft structure.

[0056] <Effects of this embodiment> (1) The electric vehicle 100 described above has an improved steering feel while maintaining the proportions of a sports car through an ingenious layout of the equipment.

[0057] (2) In the electric vehicle 100, the transmission unit 18 is disposed below the drive shaft 21. In the electric vehicle 100, the intermediate shaft 17 passes below the drive shaft 21 and connects the steering wheel 15 and the transmission unit 18.

[0058] (3) In the electric vehicle 100, the motor 25, the reduction gear 26, the drive shaft 21, and the front wheels 10 are arranged in this order in the vehicle width direction. In the drive unit 20, the motor 25 and the reduction gear 26 are enclosed in a housing 27. The drive shaft 21 is connected to the reduction gear 26 inside the housing 27. The drive shaft 21 protrudes from an end 29 of the housing 27 on the outer side of the vehicle in the vehicle width direction and connects to the front wheels 10. The housing 27 is configured so that the end 29, which is a portion surrounding the drive shaft 21, is thinner than the central portion 28, which is a portion surrounding the motor 25 and the reduction gear 26. The intermediate shaft 17 passes along the side of the central portion 28 in the vehicle width direction and below the end 29, connecting the steering wheel 15 and the transmission unit 18.

[0059] In the housing 27 of the drive unit 20, a space is created around the end 29, which is the portion that surrounds the drive shaft 21. In the electric vehicle 100 described above, the intermediate shaft 17 is arranged so that it passes through the space around the end 29. This allows the electric vehicle 100 to have a shorter intermediate shaft 17, thereby improving the steering feel and reducing the vehicle weight.

[0060] (4) In the electric vehicle 100, brake calipers 40 are installed on the front wheels 10 and the rear wheels 11. The brake caliper 40 installed on the front wheels 10 is disposed on the rear side of the vehicle relative to the front brake disc 38. The brake caliper 40 installed on the rear wheels 11 is disposed on the front side of the vehicle relative to the rear brake disc 39.

[0061] If the brake caliper 40 is located outside the gap between the rotational axes of the front wheels 10 and rear wheels 11 of the electric vehicle 100, the brake caliper 40 will be away from the center of gravity of the electric vehicle 100. Responsiveness during cornering is improved when the equipment is mounted closer to the center of gravity and the mass is concentrated closer to the center of gravity than when the equipment is mounted farther from the center of gravity and the mass is dispersed farther from the center of gravity. In the electric vehicle 100 described above, the brake caliper 40 is located between the rotational axes of the front wheels 10 and rear wheels 11, bringing the brake caliper 40 closer to the center of gravity of the electric vehicle 100. This allows the electric vehicle 100 to improve its responsiveness during cornering.

[0062] (5) The steering mechanism includes an electric power steering system that reduces the force required to steer the steering wheel 15. The electric power steering system includes a power steering motor 22 that is driven in response to the movement of the steering wheel 15. The power steering motor 22 is disposed forward of the drive unit 20 and is connected to the transmission unit 18.

[0063] In the electric vehicle 100, a power steering motor 22 is attached to the transmission unit 18. Like the transmission unit 18, the power steering motor 22 is arranged in the space in front of the drive unit 20 that is freed up by the single-shaft structure. This allows the electric vehicle 100 to accommodate the power steering motor 22 while maintaining the proportions of a sports car.

[0064] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0065] As shown in Fig. 1, the electric vehicle 100 has the driver's seat 12 located on the Lh side of Fig. 1 and the passenger seat 13 located on the Rh side of Fig. 1. The positions of the driver's seat 12 and the passenger seat 13 may be reversed. In this case, the position at which the handle 15 is mounted is also reversed, and therefore the positions of the column 16 and the intermediate shaft 17 are also reversed.

[0066] In the electric vehicle 100 described above, the intermediate shaft 17 passes through the side surface of the central portion 28 of the drive unit 20 on the Lh side in Fig. 1 and the end of the end portion 29. If the positions of the driver's seat 12 and the passenger seat 13 are reversed, the intermediate shaft 17 passes through the side surface of the central portion 28 of the drive unit 20 on the Rh side in Fig. 1 and the end of the end portion 29, connecting the steering wheel 15 and the transmission unit 18.

[0067] In the electric vehicle 100 described above, the front wheels 10 are drive wheels. The electric vehicle 100 may be a four-wheel drive vehicle in which the rear wheels 11 are also driven in addition to the front wheels 10. In the electric vehicle 100 described above, the transmission unit 18 is disposed below the drive shaft 21. The position of the transmission unit 18 provided in the electric vehicle 100 is not limited to that described in the above embodiment. For example, the transmission unit 18 may be disposed above the drive shaft 21.

[0068] In the electric vehicle 100 described above, the intermediate shaft 17 passes below the drive shaft 21 to connect the steering wheel 15 and the transmission unit 18. The configuration of the intermediate shaft 17 provided in the electric vehicle 100 is not limited to the above embodiment. For example, the intermediate shaft 17 may pass above the drive shaft 21 to connect the steering wheel 15 and the transmission unit 18.

[0069] In the electric vehicle 100 described above, the intermediate shaft 17 passes along the side of the central portion 28 and below the end portion 29 to connect the steering wheel 15 and the transmission unit 18. The configuration of the intermediate shaft 17 provided in the electric vehicle 100 is not limited to the above embodiment. For example, the intermediate shaft 17 may pass along the side of the end portion 29 to connect the steering wheel 15 and the transmission unit 18. Furthermore, for example, the intermediate shaft 17 may pass along the side of the central portion 28 and above the end portion 29 to connect the steering wheel 15 and the transmission unit 18.

[0070] In the electric vehicle 100 described above, the housing 27 of the drive unit 20 includes a central portion 28 and end portions 29 that are thinner than the central portion 28. The configuration of the housing 27 included in the electric vehicle 100 is not limited to the above embodiment. For example, the end portions 29 of the housing 27 may be configured to be the same thickness as the central portion 28 or thicker than the central portion 28.

[0071] 1, the end portion 29 of the drive unit 20 on both the Rh side and the Lh side is configured to be thinner than the central portion 28. In the drive unit 20 on the Rh side, which does not have the intermediate shaft 17 passing through its side, the end portion 29 does not need to be thinner than the central portion 28.

[0072] In the electric vehicle 100 described above, the drive shaft 21 is connected to the reducer 26 inside the housing 27 and protrudes from an end 29 to connect to the front wheels 10. On the other hand, for example, the reducer 26 may protrude from the housing 27, and the reducer 26 and the drive shaft 21 may be connected outside the housing 27. In this case, the end 29, which is the portion of the housing 27 that is located on the outer side of the vehicle in the vehicle width direction, does not surround the drive shaft 21.

[0073] The steering mechanism of the electric vehicle 100 described above is equipped with an electric power steering system. However, the steering mechanism of the electric vehicle 100 does not have to employ an electric power steering system as a power steering system that reduces the force required to steer the steering wheel 15.

[0074] For example, the electric vehicle 100 may be equipped with a hydraulic power steering system. For example, the electric vehicle 100 may be equipped with an electro-hydraulic power steering system. If the electric vehicle 100 does not employ an electric power steering system as its power steering system, it may not be equipped with the power steering motor 22. For example, the electric vehicle 100 may not be equipped with a power steering system.

[0075] In the electric vehicle 100 described above, the power steering motor 22 is disposed 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 that in the above embodiment. In the electric vehicle 100, the power steering motor 22 may be disposed rearward of the drive unit 20.

[0076] The electric vehicle 100 employs a rack-assist electric power steering system. The position of the power steering motor 22 in the electric vehicle 100 and the configuration of the electric power steering system are not limited to those in the above embodiment.

[0077] For example, the electric vehicle 100 may employ a column-assist electric power steering system. In this case, the power steering motor 22 is connected to the column 16 and transmits driving force to the column 16.

[0078] For example, the electric vehicle 100 may employ a pinion-assist electric power steering system. In this case, the power steering motor 22 is connected to a pinion gear in a rack-and-pinion gear provided in the transmission unit 18, and transmits driving force to the pinion gear.

[0079] The steering mechanism in the electric vehicle 100 described above uses a rack and pinion gear for the transmission unit 18. However, the steering mechanism in the electric vehicle 100 described above does not have to use a rack and pinion gear for the transmission unit 18. For example, the steering mechanism may use a ball nut type for the transmission unit 18.

[0080] The manner in which the suspension arm 36 is connected to the vehicle body in the electric vehicle 100 is not limited to the manner shown in Fig. 4. In other words, the number and positions of the bushings 37 provided in the electric vehicle 100 are not limited to the manner shown in Fig. 4.

[0081] 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 configuration of the drive units 20 included in the electric vehicle 100 is not limited to the above embodiment.

[0082] For example, the electric vehicle 100 may have a drive unit 20 connected to both the right front wheel and the left front wheel, rather than having two drive units 20. Hereinafter, an electric vehicle 100 employing such a configuration will be referred to as an electric vehicle 100 of a first modified example.

[0083] For example, in the electric vehicle 100, one drive shaft 21 may be disposed so as to pass through the rotation axes of the motors 25 provided in the two drive units 20 on the left and right. Hereinafter, the electric vehicle 100 employing this configuration will be referred to as the electric vehicle 100 of the second modified example.

[0084] The configuration of the drive unit 20 provided in the electric vehicle 100 is not limited to the form shown in Fig. 3. For example, the drive unit 20 provided in the electric vehicles 100 of the first and second modified examples may include a differential gear in addition to the motor 25 and the reducer 26.

[0085] In the electric vehicle 100, the position at which the brake caliper 40 is disposed is not limited to that in the above embodiment. In the electric vehicle 100 described above, the brake caliper 40 installed on the front wheel 10 is disposed on the rear side of the vehicle relative to the front brake disc 38. On the other hand, the brake caliper 40 installed on the front wheel 10 may be disposed on the front side of the front brake disc 38 relative to the vehicle.

[0086] In the electric vehicle 100 described above, the brake caliper 40 installed on the rear wheel 11 is disposed on the vehicle front side of the rear brake disc 39. On the other hand, the brake caliper 40 installed on the rear wheel 11 may be disposed on the vehicle rear side of the rear brake disc 39.

[0087] <Additional Notes> The technical ideas that can be understood from the above-described embodiment and modified examples will be described. [Appendix 1] An electric vehicle in which the front wheels are driven by electricity stored in a battery, the vehicle comprising: a drive unit including a motor and a reducer that transmits rotation by the motor to a drive shaft; and a steering mechanism that controls the turning angle of the front wheels in response to operation of the steering wheel; the battery is disposed across the front and rear of the cabin between the driver's seat and the passenger seat; the drive unit has a uniaxial structure in which the reducer and the drive shaft are disposed on an extension of the rotation shaft of the motor and is disposed between the front wheels; the steering mechanism is disposed in front of the drive unit and includes a transmission unit that converts movement of the steering wheel into movement in the vehicle width direction, and hub caps that are disposed on both ends of the transmission unit in the vehicle width direction and are provided on the left and right front wheels. an electric vehicle comprising: a tie rod connecting a rear wheel and the transmission unit; an intermediate shaft that transmits the movement of the steering wheel to the transmission unit; a kingpin that is the pivot axis of the hub carrier; and a suspension arm that connects a vehicle body and the kingpin, wherein the suspension arm is connected to the vehicle body via a plurality of bushings, and of the plurality of bushings, the bushings arranged at the front of the vehicle have higher rigidity than the bushings arranged at the rear of the vehicle, the tie rod is connected to the hub carrier further forward of the kingpin, and the intermediate shaft passes through a side of the drive unit in the vehicle width direction, connecting the steering wheel and the transmission unit.

[0088] [Appendix 2] The electric vehicle described in [Appendix 1], wherein the transmission unit is positioned below the drive shaft, and the intermediate shaft passes below the drive shaft to connect the steering wheel and the transmission unit.

[0089] [Appendix 3] An electric vehicle as described in [Appendix 2], wherein the motor, the reducer, the drive shaft, and the front wheels are arranged in this order in the vehicle width direction, and in the drive unit, the 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 on the outer side of the vehicle in the vehicle width direction to connect to the front wheels, and the end part of the housing which surrounds the drive shaft is thinner than the central part which surrounds the motor and the reducer, and the intermediate shaft passes along the side of the central part in the vehicle width direction and below the end part, connecting the steering wheel and the transmission unit.

[0090] [Appendix 4] An electric vehicle according to any one of [Appendix 1] to [Appendix 3], wherein brake calipers are provided on the front wheels and rear wheels, the brake calipers provided on the front wheels being positioned on the rear side of the vehicle on the front brake disc, and the brake calipers provided on the rear wheels being positioned on the front side of the vehicle on the rear brake disc.

[0091] [Appendix 5] An electric vehicle as set forth in any one of [Appendix 1] to [Appendix 4], wherein the steering mechanism includes an electric power steering system that reduces the force required to steer the steering wheel, the electric power steering system includes a power steering motor that is driven in accordance with the movement of the steering wheel, and the power steering motor is disposed forward of the drive device and connected to the transmission unit. [Explanation of symbols]

[0092] 10...Front wheel 11...Rear wheel 12...Driver's seat 13…Passenger seat 14...Battery 15...Handle 16...Column 17...Intermediate shaft 18...Transmission section 19...Tie rod 20...Driver 21...Drive shaft 22...Power steering motor 25...Motor 26…Reducer 27…Housing 28...Central part 29...End 30...Sun gear 31...Pinion gear 32…Ring gear 33...Planetary carrier 34...Hub carrier 35...Kingpin 36...Suspension arm 37…Bush 38...Front brake disc 39...Rear brake disc 40...Brake caliper 100...electric vehicle

Claims

1. It is an electric vehicle that drives the front wheels using electricity stored in a battery. a drive device including a motor and a reducer that transmits rotation by the motor to a drive shaft; a steering mechanism that controls the turning angle of the front wheels in response to the operation of a steering wheel, The battery is disposed between the driver's seat and the passenger seat across the front and rear of the cabin, the drive device has a uniaxial structure in which the reducer and the drive shaft are disposed on an extension of a rotation shaft of the motor, and is disposed between the front wheels; The steering mechanism includes: a transmission unit disposed in front of the drive unit and converting movement of the steering wheel into movement in the vehicle width direction; tie rods that are disposed on both ends of the transmission unit in the vehicle width direction and connect the transmission unit to hub carriers provided on the left and right front wheels; an intermediate shaft that transmits the movement of the handle to the transmission unit; a kingpin that is a rotation axis of the hub carrier; a vehicle body and a suspension arm that connects the kingpin, the suspension arm is connected to the vehicle body through a plurality of bushings, Among the plurality of bushes, the bushes arranged at the front of the vehicle have higher rigidity than the bushes arranged at the rear of the vehicle, the tie rod is connected to the hub carrier at a position forward of the kingpin, The intermediate shaft passes through a side surface of the drive unit in the vehicle width direction and connects the steering wheel and the transmission unit. Electric car.

2. The transmission unit is disposed below the drive shaft, The intermediate shaft passes under the drive shaft and connects the steering wheel and the transmission unit. The electric vehicle of claim 1 .

3. the motor, the reducer, the drive shaft, and the front wheels are arranged in this order in the vehicle width direction, In the drive device, the motor and the reducer are enclosed in a housing, the drive shaft is connected to the reducer inside the housing, protrudes from an end of the housing on the vehicle outer side in the vehicle width direction, and is connected to the front wheels; the housing is configured so that the end portion surrounding the drive shaft is thinner than the central portion surrounding the motor and the reducer, The intermediate shaft passes along the side of the central portion in the vehicle width direction and below the end portion, connecting the handlebar and the transmission portion. The electric vehicle according to claim 2 .

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

5. The steering mechanism includes an electric power steering system that reduces the force required to steer the steering wheel, The electric power steering system includes a power steering motor that is driven in response to movement of the steering wheel, The power steering motor is disposed forward of the drive device and is connected to the transmission section. The electric vehicle according to any one of claims 1 to 3.

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