Saddle-type electric vehicle

Abstract

To provide a straddle type electric vehicle that is able to restrict the influence of the layout of driving components on the design of a vehicle body.SOLUTION: A straddle type electric vehicle includes: a vehicle body frame 5 having a head pipe 16, a main frame 17, a pair of left and right pivot frames 18, and upper and lower cross members 22, 23 connecting the left and right pivot frames 18 to each other; a swing arm 30; and a power unit 8 disposed behind the left and right pivot frames 18. The power unit 8 includes a unit case 53 accommodating an electric motor 50. The unit case 53 includes a mount portion 56 fastened to the upper and lower cross members 22, 23 in directions toward front and rear of the vehicle, between the left and right pivot frames 18. A pivot shaft 33 of the swing arm 30 is supported by the left and right pivot frames 18 and the mount portion 56.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a straddle-type electric vehicle. [Background Art]

[0002] In a straddle-type electric vehicle that travels by output of an electric motor, there are various arrangements for the vehicle driving battery, control device, and electric motor. For example, in Patent Document 1, a plurality of batteries are arranged vertically side by side between left and right main frames, the control device is arranged between the battery and a pivot shaft, and the electric motor is arranged behind the pivot shaft of a swing arm. A front portion of the motor case is fastened to the battery case and supports a front end portion of the swing arm. For example, in Patent Document 2, a battery is arranged between left and right main frames, a control device is arranged below the battery, and an electric motor is arranged in front of a pivot frame. A motor case is fastened to the pivot frame. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2020-97312 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2012-91595 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] By the way, in the configuration described above, when an electric motor is arranged behind a pivot shaft and the swing arm is supported by the motor case, the motor case receives loads related to input and output of the electric motor and also receives loads from the swing arm, so excessive rigidity is required. In this case, when also considering the balance with the main frame at the front part of the vehicle body, adjustment of the strength and rigidity of the motor case becomes complicated. In particular, in the case of small, saddle-type electric vehicles, the layout of heavy drive components such as batteries, control devices, and electric motors has a significant impact on frame rigidity and, consequently, the vehicle body design, so there was room for further consideration.

[0005] Therefore, the present invention aims to provide a saddle-type electric vehicle that can minimize the impact of the layout of drive components on the vehicle body design. [Means for solving the problem]

[0006] As a means of solving the above problems, a first aspect of the present invention includes a vehicle body frame (5) having a head portion (16) that supports steering wheels (2) in a steerable manner, a main frame (17) extending rearward from the head portion (16), a pair of left and right pivot frames (18) extending downward from the rear end of the main frame (17), and cross members (22, 23) connecting the left and right pivot frames (18) together, a swing arm (30) that supports the drive wheels (3), and an electric motor (50) for driving the vehicle. The vehicle comprises a power unit (8) positioned behind the pivot frame (18) in a side view of the vehicle, the power unit (8) includes a unit case (53) housing an electric motor (50), the unit case (53) includes a mounting portion (56) fastened to a cross member (22, 23) between the left and right pivot frames (18) in the front-rear direction of the vehicle, and the pivot axis (33) of the swing arm (30) is supported by the left and right pivot frames (18) and the mounting portion (56). This configuration provides the following advantages by equipping the power unit case, which includes the electric motor for vehicle drive, with mounting parts that are fastened to the vehicle frame in the longitudinal direction of the vehicle. Specifically, the connection between the vehicle frame and the power unit has a structure that can easily withstand the load caused by the input and output of the electric motor (load associated with the acceleration and deceleration of the vehicle). This reduces (distributes) the load on the fastening parts of the power unit, making it easier to adjust the strength and rigidity of the unit case and, consequently, the entire vehicle body. By supporting the pivot axis of the swingarm with the left and right pivot frames and the unit case, it is possible to optimize the case rigidity by making it easier to adjust the strength and rigidity of the unit case compared to when the pivot axis is supported by the unit case alone.

[0007] A second aspect of the present invention is, in the first aspect described above, the cross members (22, 23) include an upper cross member (22) connecting the upper parts of the left and right pivot frames (18) and a lower cross member (23) connecting the lower parts of the left and right pivot frames (18). The upper part of the mounting portion (56) is provided with an upper fastening portion (57) fastened to the upper cross member (22), and the lower part of the mounting portion (56) is provided with a lower fastening portion (58) fastened to the lower cross member (23) in a range that is inward in the vehicle width direction from the upper fastening portion (57). With this configuration, the lower fastening portion of the unit case is fastened to the lower cross member within a range that is more inward in the vehicle width direction than the upper fastening portion, which makes it possible to narrow the left-right width of the lower part of the unit case as much as possible, and makes it easier to secure the bank angle of the vehicle body.

[0008] A third aspect of the present invention is that, in the first or second aspect described above, each of the left and right pivot frames (18) is provided with a separate pivot block (19) relative to the main body side of the pivot frame (18), and each of the left and right pivot blocks (19) supports the pivot axis (33) of the swing arm (30) and is fastened to the main body side of the pivot frame (18) on the same side in the vehicle longitudinal direction. In this configuration, the pivot shaft is supported by a separate pivot block relative to the pivot frame body, and the pivot block is fastened to the pivot frame body in the vehicle's longitudinal direction. This expands the range of fastening points in the vehicle's longitudinal direction, including the fastening points of the unit case, thereby increasing the rigidity of the unit case assembly, including the pivot block and pivot shaft, to the vehicle frame body. The assembly of the pivot block, pivot shaft, and power unit can be attached together to the vehicle frame body by fastening in the longitudinal direction.

[0009] A fourth aspect of the present invention is that, in the third aspect described above, steps (27) on the same side are attached to each of the left and right pivot blocks (19). With this configuration, the steps are supported by left and right pivot blocks, allowing the step load to be borne by the high-strength pivot blocks. This makes it easier to adjust the strength and rigidity of the main body of the vehicle frame.

[0010] A fifth aspect of the present invention is that, in the third or fourth aspect described above, multiple types of left and right pivot blocks (19) are provided, each having a different axial position of the pivot axis (33). With this configuration, by setting up multiple types of pivot blocks with different pivot axis center positions, the pivot position can be easily varied by replacing the pivot block, thereby increasing the versatility of vehicle parts.

[0011] A sixth aspect of the present invention is a rear cushion (32) connected to a swing arm (30) in any one of the first to fifth aspects described above, wherein the rear cushion (32) is positioned above the power unit (8) in a posture in which the stroke direction is oriented in the front-rear direction of the vehicle, with its front end connected to the vehicle frame (5) or power unit (8) in front of the drive shaft (50a) of the electric motor (50), and its rear end connected to the swing arm (30) in rearward of the drive shaft (50a) of the electric motor (50). In this configuration, the rear cushion is positioned to extend in the longitudinal direction of the vehicle, straddling the drive shaft of the electric motor. The front end of the rear cushion is connected to the vehicle frame or power unit, and the rear end of the rear cushion is connected to the swingarm. By connecting the front end of the rear cushion to the area where the rigidity is increased by fastening the vehicle frame and power unit, the front end of the rear cushion can be supported with high rigidity without the need for additional reinforcement at the connection point of the front end of the rear cushion. Since the rear cushion extends in the longitudinal direction of the vehicle, straddling the drive shaft of the electric motor above the power unit, it is possible to efficiently secure the stroke amount of the rear cushion while avoiding the power unit located behind the pivot frame. Furthermore, compared to the case where the rear cushion is positioned between the power unit and the rear wheel, the rear wheel setback and thus the increase in wheelbase can be suppressed.

[0012] A seventh aspect of the present invention is, in the sixth aspect described above, the swing arm (30) comprises a pair of left and right arm bodies (36) and an arm connecting portion (37) that connects the left and right arm bodies (36) to each other, the left and right arm bodies (36) are curved so as to be convex upward when viewed from the side of the vehicle, the arm connecting portion (37) connects the upper ends of the left and right arm bodies (36), and a link mechanism (31) that connects the rear end of the rear cushion (32) to the swing arm (30) is arranged inside the arm connecting portion (37). In this configuration, the left and right arm bodies of the swingarm are bent in an upward convex shape, and the upper ends of the left and right arm bodies are connected by an arm connecting section. Since the arm connecting section is positioned towards the top of the swingarm, it efficiently connects the left and right arm bodies while avoiding the power unit behind the pivot frame, and also makes it easier to connect the rear end of the rear cushion, which is positioned above the power unit. A link mechanism for connecting the rear end of the rear cushion is positioned inside the arm connecting section, which increases the degree of freedom in setting the suspension characteristics and allows for a compact link-type rear suspension configuration.

[0013] An eighth aspect of the present invention is that, in any one of the first to seventh aspects described above, the vehicle frame (5) includes a box-shaped portion (26) comprising a pair of left and right side wall portions (26a) extending downward from each of the left and right main frames (17), a bottom wall portion (26b) connecting the lower ends of the left and right side wall portions (26a) together, and a front wall portion (26c) connecting the front ends of the left and right side wall portions (26a) together. With this configuration, a box-shaped section, including the left and right side walls, bottom wall, and front wall, is provided below the left and right main frames of the vehicle body frame. This box-shaped section can be used as a support structure for the battery mounted between the left and right main frames. This reduces the number of parts by eliminating or simplifying the structure for supporting the battery, and the rigidity of the vehicle body frame, which houses the heavy battery, can be increased by the box-shaped section.

[0014] A ninth aspect of the present invention is, in the eighth aspect described above, a control device (90) for controlling the drive of an electric motor (50), wherein the control device (90) is fastened to the lower surface of the bottom wall (26b) of the box-shaped portion (26). With this configuration, by fastening the control device to the underside of the box-shaped section of the vehicle frame, the structure supporting the control device can be eliminated or simplified, thereby reducing the number of parts. Furthermore, the bottom wall of the box-shaped section is reinforced by the fastening of the control device, further increasing the rigidity of the vehicle frame.

[0015] A tenth aspect of the present invention is that, in any one of the first to ninth aspects described above, the electric motor (50) is positioned at a height that overlaps with the control device (90) when viewed from the front-rear direction of the vehicle. With this configuration, the control device and the electric motor are positioned at overlapping heights, which not only brings the battery and control device, both mounted inside the box-shaped section, closer together, but also brings the control device and the electric motor closer together. This shortens the power lines between the battery, control device, and electric motor, and also concentrates mass by concentrating heavy components.

[0016] In an eleventh aspect of the present invention, in any one of the first to tenth aspects above, the electric motor (50) and the drive wheel (3) are connected via an endless transmission member (73), and a tensioner (75) that applies tension to the transmission member (73) is supported by the unit case (53) of the power unit (8). According to this configuration, by supporting the tensioner for the transmission member on the unit case, tension can be efficiently applied to the transmission member in the vicinity of the power unit. Effects of the Invention

[0017] According to the present invention, it is possible to provide a saddle-ride type electric vehicle that can suppress the influence of the layout of driving components on vehicle body design. Brief Description of the Drawings

[0018] [Figure 1] It is a left side view of the electric two-wheeled vehicle according to the embodiment. [Figure 2] It is a left side view of essential parts of the above electric two-wheeled vehicle. [Figure 3] It is a perspective view of a rear wheel suspension system and a power unit of the above electric two-wheeled vehicle. [Figure 4] It is a perspective view further showing a vehicle body frame in FIG. 3. [Figure 5] It is a front view of the essential parts of FIG. 4 as seen from the front. [Figure 6] It is a perspective view of the configuration in FIG. 2 as seen from an obliquely upper rear side. [Figure 7] It is a perspective view of the vehicle body frame as seen from an obliquely upper rear side. [Figure 8] It is a left side view showing essential parts of the rear wheel suspension system. [Figure 9] It is a left side view including a partial cross-section of the rear wheel suspension system. [Figure 10] It is a front view of the swing arm. [Figure 11] It is a rear view of the swing arm. [Figure 12] It is a top view of the swing arm. [Figure 13]This is a perspective view of the lower part of the mounting section. [Figure 14] This is a perspective view showing a modified example of the connection terminal section and the recessed section. [Figure 15] This is a perspective view corresponding to Figure 3, which shows a first modified example of the embodiment. [Figure 16] This is a front view of the rear suspension system of the first modified example described above. [Figure 17] This is a right side view of the main part of the first modified example shown in the figure. [Figure 18] This is a perspective view of the area around the pivot adjuster of the first modified example shown above. [Figure 19] This is a perspective view showing the vehicle frame of a second modified embodiment. [Figure 20] This is a front view of the vehicle frame of the second modified example shown above. [Modes for carrying out the invention]

[0019] Embodiments of the present invention will be described below with reference to the drawings. Unless otherwise specified, directions such as front, rear, left, and right in the following description are the same as the directions of the vehicle described below. In addition, in the drawings used in the following description, arrows FR indicating the front of the vehicle, LH indicating the left side of the vehicle, UP indicating the top of the vehicle, and CL indicating the center of the left and right sides of the vehicle are shown in appropriate places.

[0020] Figure 1 is a left side view of the electric two-wheeled vehicle (saddle-type electric vehicle) 1 of the embodiment. As shown in Figure 1, the electric two-wheeled vehicle 1 of this embodiment is an on-road type saddle-type electric vehicle, and is designed to be small and lightweight, with concentrated mass and a low center of gravity. The electric motorcycle 1 comprises a front wheel 2, a rear wheel 3, a front suspension system 4, a body frame 5, a body cover 6, a rear suspension system 7, a power unit 8, a battery unit 80, and a PCU (control unit) 90.

[0021] The front suspension system 4 comprises a pair of left and right front forks 10 that pivotally support the front wheel 2 at their lower ends, a top bridge 11 and a bottom bridge 12 provided between the upper parts of the pair of front forks 10, and a stem pipe (not shown) provided between the top bridge 11 and the bottom bridge 12 and inserted into the head pipe 16. The front wheel 2 is steerably supported by the head pipe 16 of the vehicle frame 5 via the front suspension system 4. For example, a steering handle (not shown) is mounted on the top bridge 11. In this embodiment, a telescopic front fork 10 is exemplified as the front suspension of the electric motorcycle 1, but the configuration is not limited to this. For example, the front suspension may be of other types, such as a link type using a swing arm.

[0022] Figure 2 is a left side view of the main part of the electric motorcycle 1, Figure 3 is a perspective view of the rear suspension system 7 and power unit of the electric motorcycle 1, and Figure 4 is a perspective view of Figure 3 with the vehicle frame 5 further shown. Referring to Figures 1, 2, and 4, the vehicle frame 5 comprises a head pipe 16, a pair of left and right main frames 17, a pair of left and right pivot frames 18, an upper cross member 22 connecting the upper parts of the left and right pivot frames 18, and a lower cross member 23 connecting the lower parts of the left and right pivot frames 18.

[0023] The head pipe 16 is located at the center CL of the left and right sides of the vehicle body and is provided as a single unit at the front end of the vehicle body frame 5. The head pipe 16 is rotatably supported by the stem pipe through which it is inserted. The head pipe 16 is not limited to a cylindrical shape, and may have irregularities or openings formed on it as appropriate.

[0024] The pair of main frames 17 branch off to the left and right from the top of the head pipe 16 and extend downward and rearward. In a plan view from above, the front part of the pair of main frames 17 extends diagonally outward in the vehicle width direction and behind the head pipe 16, then curves and extends rearward. In a plan view from above, the rear part of the pair of main frames 17 extends linearly along the front-rear direction. In a side view, the front part of the pair of main frames 17 has a vertical width equivalent to the axial length of the head pipe 16. In a side view, the rear part of the pair of main frames 17 is formed so that its vertical width narrows towards the rear and lower.

[0025] A pair of pivot frames 18 each extend downward from the rear ends of the main frames 17 on the same side. A pivot shaft 33 extending in the vehicle width direction is installed between the upper intermediate portions of the pair of pivot frames 18 in the vertical direction. In this embodiment, "intermediate" means not only the center between the two ends of the object, but also the inner range between the two ends of the object.

[0026] The upper cross member 22 extends in the vehicle width direction above the pivot shaft 33 and connects the upper parts of the pair of pivot frames 18. On the outer side of the upper cross member 22 in the vehicle width direction, there is a pair of left and right upper fastening parts 22a that fasten the upper part of the mounting part 56 of the unit case 53 of the power unit 8.

[0027] The lower cross member 23 extends in the vehicle width direction below the pivot shaft 33 and connects the lower parts of a pair of pivot frames 18. A single lower fastening portion 23a is provided at the center of the lower cross member 23 in the vehicle width direction, which fastens the lower part of the mounting portion 56 of the unit case 53 of the power unit 8.

[0028] Referring to Figure 1, the vehicle frame 5 further includes a rear frame 24 that supports the seat 9 for the occupant. The rear frame 24 is detachably fixed, for example, at its front end to the upper rear of the left and right main frames 17 by bolt fastening or the like. Step brackets 27a that support the left and right steps 27 are detachably fixed to the rear of the left and right pivot frames 18 by bolt fastening.

[0029] Figure 5 is a front view of the main part of Figure 4, viewed from the front; Figure 6 is a perspective view of the configuration of Figure 2, viewed from the diagonal upper rear; and Figure 7 is a perspective view of the vehicle body frame 5, viewed from the diagonal upper rear. Referring to Figures 1, 2, and 6, the vehicle frame 5 has a battery unit 80 for driving located behind the head pipe 16 and in front of the left and right pivot frames 18, between the left and right main frames 17. The battery unit 80 is designed to be removable from above within the space formed between the left and right main frames 17 in a plan view. The battery unit 80 is protected from external disturbances from the outside in the vehicle width direction by being sandwiched between the left and right main frames 17 from the outside in the vehicle width direction.

[0030] The vehicle frame 5 supports the power unit 8 for vehicle operation at the rear of the left and right pivot frames 18. The power unit 8 comprises an electric motor 50 and a reduction gear 51, and these electric motor 50 and reduction gear 51 are housed in a single unit case 53. The power unit 8 is fastened and fixed from the rear side of the vehicle to the bulkhead portion 25 formed by the left and right pivot frames 18 and upper and lower cross members 22 and 23 of the vehicle body frame 5. Even with the power unit 8 supported behind the left and right pivot frames 18, the front-to-rear weight distribution can be optimized by positioning the battery unit 80 closer to the head pipe 16.

[0031] Referring to Figure 1, the body cover 6 covers the body frame 5, etc. The body cover 6 includes a front cowl 41, a rear cowl 42, a seat front cover 43, and an under cowl 44. The front cowl 41 covers the area from the front of the head pipe 16 to the left and right sides, and the left and right sides extend further rearward, covering the sides of the vehicle body from the outside in the width direction. The rear cowl 42 covers the area extending from the left and right sides of the rear frame 24 to the rear. The seat 9 is positioned on top of the rear cowl 42.

[0032] The front seat cover 43 is formed to bulge upward in the space between the left and right main frames 17 in front of the seat 9. The front seat cover 43 is designed to resemble a fuel tank. The front seat cover 43 forms a knee grip area that is held between the knees of the occupant seated on the seat 9. The upper part of the battery unit 80 is housed inside the front seat cover 43. The front seat cover 43 covers the upper part of the battery unit 80 from above. The undercowl 44 is located below the front cowl 41 and covers the lower part of the vehicle from below.

[0033] Figure 8 is a left side view showing the main part of the rear suspension system 7, and Figure 9 is a left side view including a partial cross-section of the rear suspension system 7. Referring to Figures 8 and 9, the rear suspension system 7 includes a swing arm 30 that pivotally supports the rear wheel 3 at its rear end, a link mechanism 31 connected to the front upper part of the swing arm 30, and a rear cushion 32 that spans between the link mechanism 31 and the upper cross member 22. The swingarm 30 is positioned below the rear of the vehicle body and extends in the front-rear direction. The front end of the swingarm 30 is supported by a pair of pivot frames 18 and a mounting portion 56 of the unit case 53, via a pivot shaft 33, so as to be able to swing up and down. The mounting portion 56 is the fastening point between the vehicle body frame 5, the power unit 8, the swingarm 30, and the rear cushion 32, and makes it easy to obtain the support rigidity of the pivot shaft 33.

[0034] The link mechanism 31 comprises a link arm 34 extending in the vertical direction and a link member 35 shaped like an inverted triangle in side view. The link mechanism 31 is positioned inside the upper projection (arm connecting portion 37) formed on the front upper part of the swing arm 30 in side view. The link arm 34 extends downward from inside the upper projection, and its lower end is rotatably connected to the link connecting portion 53a at the rear end of the unit case 53. The upper end of the link arm 34 is rotatably connected to the rear top of the link member 35. The front top of the link member 35 is rotatably connected to the upper projection of the swing arm 30. The rear end of the cushion unit 32 is rotatably connected to the lower top of the link member 35. The front end of the cushion unit 32 is rotatably connected to the cushion front connecting portion 56d of the mount portion 56. The link mechanism 31 provides a progressive effect, reducing the cushion stroke when the rear load is small and the swing arm 30 is oscillating slowly, and increasing the cushion stroke when the rear load is large and the swing arm 30 is oscillating slowly.

[0035] The rear cushion 32 is located on the inner side of the vehicle width direction at the rear of the vehicle body (for example, on the center CL of the left and right sides of the vehicle body). The rear cushion 32 is formed in a cylindrical shape with a compression coil spring arranged on the outer circumference of a damper cylinder, and is positioned in a horizontal position with its axial direction generally aligned with the vehicle's longitudinal direction. The rear cushion 32 is positioned above the power unit 8 and extends in the longitudinal direction. The front cushion connecting portion 56d, which connects the front end of the rear cushion 32, is located near the upper fastening portion 57 (fastening portion with the vehicle body frame 5) of the mount portion 56, and shares the strength and rigidity of the upper fastening portion 57.

[0036] The rear cushion 32 has an angle θ (angle of the central axis) with respect to the vertical line VL in a side view, for example, set in the range of 45 to 120 degrees. The rear cushion 32 is positioned so as to fit within the vertical width of the swing arm 30. The rear cushion 32 is positioned almost horizontally to avoid the large-diameter electric motor 50 located behind the pivot frame 18. This ensures that the position of the rear cushion 32 does not affect the wheelbase, and thus the stroke amount of the rear cushion 32 and, consequently, the damper capacity are secured. By keeping the vertical height of the rear cushion 32's position low, space is freed up under the seat, making it applicable to vehicles with low seat heights.

[0037] The power unit 8 includes an electric motor 50 for driving the vehicle, a reduction gear 51 (not shown) for reducing the output of the electric motor 50, an output shaft 70 for outputting the power of the electric motor 50 reduced by the reduction gear 51, and a unit case 53 for housing the drive unit including the electric motor 50 and the reduction gear 51. The power unit 8 is configured as an integrated unit including the electric motor 50, the reduction gear 51, the output shaft 70, and the unit case 53.

[0038] The electric motor 50 is positioned with its drive shaft (motor drive shaft) 50a aligned with the vehicle width direction. A gear-type reduction gear 51 is positioned on one side (left side) of the electric motor 50. The output shaft 70 extends in the vehicle width direction, with its left end 70a protruding outside the unit case 53. In a side view, the output shaft 70 is located on the upper front side of the motor drive shaft 50a. In the power unit 8, the output shaft 70 and the motor drive shaft 50a are provided on separate shafts. However, depending on the configuration of the reduction gear 51, the output shaft 70 and the motor drive shaft 50a may be provided coaxially.

[0039] The unit case 53 forms the outer shape of the power unit 8. The unit case 53 integrally includes a drum-shaped motor case 54 that houses the electric motor 50, a box-shaped gear case 55 that houses the reduction gear 51 and is located on the left side of the motor case 54, and a mounting portion 56 provided at the front of the unit case 53.

[0040] Referring to Figure 8, the left end 70a of the output shaft 70 protrudes outside the unit case 53, and this left end 70a is connected to the rear wheel 3 via a chain-type transmission mechanism 74. In the figure, reference numeral 71 denotes a drive sprocket attached to the left end 70a of the output shaft 70, reference numeral 72 denotes a driven sprocket attached to the left side of the rear wheel 3, and reference numeral 73 denotes an endless drive chain wrapped around both sprockets 71 and 72.

[0041] A tensioner 75, which applies tension to the drive chain 73, is supported at the bottom of the unit case 53 of the power unit 8. The tensioner 75 brings the tensioner pulley 76 into contact with the drive chain 73 from the outer circumference of the winding area of ​​the drive chain 73 when viewed from the side. The tensioner pulley 76 is supported on the rear left side of the unit case 53 via the tensioner arm 77.

[0042] The tensioner arm 77 extends rearward along the underside (slack side) of the drive chain 73 in a side view, and supports the tensioner pulley 76 at its rear end. The front end of the tensioner arm 77 is rotatably supported by the unit case 53, and the rear end is biased upward (towards the drive chain 73). The tensioner 75 brings the tensioner pulley 76 into contact with the drive chain 73 with a biasing force, thereby applying appropriate tension to the drive chain 73. The tensioner 75 is installed in a crescent-shaped empty space behind the gear case 55 on the left side of the motor case 54. The tensioner 75 applies tension to the drive chain 73 near the center between the output shaft 70 and the rear wheel axle 3a. This allows tension to be applied to the drive chain 73 efficiently with less force. In this embodiment, a chain-type transmission mechanism 74 is exemplified, but a belt-type transmission mechanism may also be used. The tensioner 75 can be configured to correspond to transmission components such as a drive chain 73 or a drive belt.

[0043] Referring to Figure 1, a Power Control Unit (PCU) 90 that controls the electric motor 50 is located below the power unit 8. The PCU 90 is a control device that includes a Power Drive Unit (PDU), which is a motor driver, and an Electric Control Unit (ECU) that controls the PDU. The PDU includes an inverter and converts the current supplied from the battery unit 80 from DC to AC and supplies power to the electric motor 50.

[0044] The PCU 90 is housed in a rectangular parallelepiped-shaped PCU cover 91 that is positioned below the battery case 81. The PCU cover 91 helps to suppress disturbances reaching the PCU 90 and also prevents the operating noise generated by the PCU 90 from spreading to the surroundings. The PCU cover 91 may have sound-absorbing material attached to it, or the cover itself may be made of a sound-absorbing material. The lower end of the PCU90 is at the same height as the lower end of the vehicle frame 5 (in this embodiment, the lower end of the lower cross member 23). The PCU90 is covered from below by an under cowl 44 that extends below the front cowl 41.

[0045] The power unit 8 is connected (supported) to the vehicle body frame 5 by fastening a mounting portion 56 formed on the front of the unit case 53 to the bulkhead portion 25 of the vehicle body frame 5. The bulkhead portion 25 is formed in a frame shape that opens in the front-rear direction by the left and right pivot frames 18 and the upper and lower cross members 22 and 23. The bulkhead portion 25 may have, for example, a wall that closes the opening. In this case, the operating noise of the power unit 8 can be made less likely to reach the front (occupant side).

[0046] In a side view, the power unit 8 is positioned mostly behind the left and right pivot frames 18, excluding the mounting portion 56. The upper part of the power unit 8 is positioned so as to fit inside the front of the swing arm 30 (between the front parts of the left and right arm bodies 36) in a side view. Figures 8 and 9 show the rear wheel suspension system 7 in the unloaded 1G state (stationary state with vehicle weight added). The lower end of the power unit 8 is at the same height as the lower end of the body frame 5 (lower cross member 23). The lower end of the power unit 8 is covered from below by the rearward extension of the under cowl 44.

[0047] The mounting portion 56 is provided with a first pivot shaft support portion that supports the pivot shaft 33 by passing it through it. The first pivot shaft support portion is positioned to avoid the electric motor 50 when viewed from the side, as the pivot shaft 33 passes through it. For this reason, the first pivot shaft support portion is located on the outside of the unit case 53 when viewed from the side. From the viewpoint of avoiding an increase in the size of the unit case 53, it is difficult to make the first pivot shaft support portion a large structure that can secure strength and rigidity on its own. In this embodiment, the strength and rigidity of the first pivot shaft support portion are ensured by fastening the mounting portion 56 to the bulkhead portion 25. In addition to being supported by the mounting portion 56, the pivot shaft 33 is also supported on its left and right sides by the left and right pivot frames 18, respectively. This makes it possible to increase the pivot rigidity of the swing arm 30 while suppressing an increase in the size of the unit case 53. The pivot shaft support portions on the left and right pivot frames 18 are referred to as the second pivot shaft support portions.

[0048] Referring to Figures 1, 2, and 6, the battery unit 80 is a rectangular parallelepiped that is elongated in the vertical direction and is housed in a battery case 81 of the same shape. The battery unit 80 obtains a predetermined high voltage by connecting, for example, multiple unit batteries in series. The battery unit 80 is formed to fit between the inner surfaces in the vehicle width direction of the left and right main frames 17 in a plan view.

[0049] In a side view, the battery unit 80 is positioned such that its upper part protrudes above the main frame 17 and its lower part protrudes below the main frame 17. The portion of the battery unit 80 that protrudes above the main frame 17 is covered from above by the front seat cover 43. The main frame 17 is positioned diagonally across the battery unit 80 on its outer side in the vehicle width direction. The portion of the battery unit 80 that protrudes below the main frame 17 is covered from the left and right outer sides by the rear sides (side cowls) of the front cowl 41.

[0050] Below the battery unit 80, the PCU 90 is positioned in a continuous line. This reduces the length of the high-voltage cables (positive and negative terminal cables) extending from the battery unit 80. Behind the PCU 90, the power unit 8 is positioned adjacent to it in the front-to-back direction. The PCU 90 and power unit 8 are positioned so that they overlap each other in the vertical and horizontal directions when viewed from the front-to-back direction. This reduces the length of the power lines (three-phase cables) between the PCU 90 and power unit 8.

[0051] The PCU90 is positioned in front of the bulkhead 25 and below the battery unit 80. This prevents the PCU90 from affecting the fastening between the power unit 8 and the vehicle frame 5, even if the PCU90 becomes larger due to the increased output of the electric motor 50. This reduces the impact on the rigidity of the vehicle frame 5 and improves the design flexibility of the vehicle. Compared to the case where the PCU90 is positioned behind the bulkhead 25, the rearward movement of the rear wheels 3 and consequently the increase in the wheelbase are suppressed.

[0052] Figure 10 is a front view of the swingarm, Figure 11 is a rear view of the swingarm, and Figure 12 is a top view of the swingarm. Referring to Figures 10 to 12, the swing arm 30 comprises a pair of left and right arm bodies 36 and an arm connecting portion 37 that connects the front ends of the left and right arm bodies 36. The left and right arm bodies 36 have a curved shape that is convex upward when viewed from the side. The left and right arm bodies 36 extend along the curved shape when viewed from the side, having, for example, a rectangular hollow cross-section. The front ends of the left and right arm bodies 36 are provided with cylindrical pivot support parts 38 through which the pivot shaft 33 is inserted. The rear ends of the left and right arm bodies 36 are provided with plate-shaped axle support parts 39 through which the rear wheel axle 3a is inserted.

[0053] The upper ends (tops) of the left and right arm bodies 36, when viewed from the side, are located forward of the center in the front-rear direction of the left and right arm bodies 36. The arm connecting portion 37 is provided so as to span between the upper ends of the left and right arm bodies 36 when viewed from the side. The inside of the arm connecting portion 37 is appropriately hollowed out, and the rear part of the rear cushion 32 and the link mechanism 31 are housed inside this arm connecting portion 37.

[0054] The upper part of the power unit 8 is positioned between the front ends of the left and right arm bodies 36. Since the rear wheels 3 are positioned close behind the power unit 8, the arm connecting portion 37 between the left and right arm bodies 36 is provided to bypass the area above the close proximity between the power unit 8 and the rear wheels 3. Inside the arm connecting portion 37, the rear end of the rear cushion 32 is connected to the link mechanism 31. The front end of the rear cushion 32 is connected to the front cushion connecting portion 56d on the mounting portion 56 of the power unit 8.

[0055] In a side view, the line connecting the center 33c of the pivot axis 33 and the center 3c of the rear wheel axle 3a is denoted by the symbol T1. The arm connecting portion 37 is located above the line T1 in a side view. The center 50c of the motor drive shaft 50a of the power unit 8 is located below the line T1. The center 70c of the output shaft 70 is located below the line T1, but is closer to the line T1 than the center 50c of the drive shaft 50a. The motor drive shaft 50a and the output shaft 70 are located behind the pivot axis 33. In a side view, the lower edge of the swing arm 30 is formed below the line T1 and approximately parallel to the line T1.

[0056] The swingarm 30 is provided with arm plate portions 36a that enclose a triangular area in a side view below each of the left and right arm bodies 36. In the swingarm 30, the left and right arm bodies 36 have a hollow cross-sectional shape, and the left and right arm plate portions 36a have a plate-like cross-sectional shape. The left and right arm plate portions 36a are formed in a plate shape with a thickness equivalent to the outer wall portion in the vehicle width direction of the arm body 36 on the same side. The outer surfaces of the left and right arm plate portions 36a are formed flush with the outer surfaces of the outer wall portion in the vehicle width direction of the arm body 36 on the same side. In a side view, the swingarm 30 appears to have an increased vertical height, but the skeletal part is the bent left and right arm bodies 36.

[0057] Since the lower part of the left and right arm bodies 36 is a plate-shaped left and right arm plate portion 36a, the rigidity of the swing arm 30 is not excessively increased. In particular, the longitudinal rigidity (bending rigidity in the front-rear and up-down directions) of the left and right arm bodies 36 is effectively reinforced by the left and right arm plate portions 36a because they are difficult to bend in the so-called in-plane direction. The lateral rigidity (bending rigidity in the left-right direction) of the left and right arm bodies 36 is not excessively reinforced because the left and right arm plate portions 36a are easily bent out-of-plane.

[0058] At the front of the swingarm 30, the portion above the straight line T1 in a side view is formed so that its width narrows as it moves upward (towards the arm connection part 37). This makes the width of the swingarm 30 near the upper end (near the arm connection part 37) narrower and more compact, minimizing the impact on the arrangement of surrounding parts. Since no protruding shape is provided below the portion along the straight line T1, the impact on the vehicle's bank angle due to an increase in the width of that portion is minimized.

[0059] At the rear of the swingarm 30, the left and right arm bodies 36, from the arm connecting portion 37 to the rear end (axle support portion 39) in the front-rear direction, are formed in a curved shape that is convex outward in the vehicle width direction when viewed from above. As a result, the lateral width between the left and right arm bodies 36 widens in front of the rear wheel axle 3a, making it easier to secure clearance with transmission components such as the drive chain 73 and belt. The lateral width near the rear wheel axle 3a (near the lower end of the swingarm 30) is kept low, thus reducing the impact on the vehicle's bank angle.

[0060] The left and right arm bodies 36 and arm plate portions 36a are smoothly curved in an S-shape when viewed from above, and are shaped in a way that makes it difficult for stress concentration to occur. The arm plate portion 36a of the left arm body 36 may be extended in a side view so as to cover the entire chain-type transmission mechanism 74 from the outside in the vehicle width direction. In this case, the arm plate portion 36a functions like a chain cover, suppressing contact of external objects with the drive chain 73 and preventing the diffusion of chain noise.

[0061] As shown in Figures 3 to 5, the front end of the unit case 53 of the power unit 8 is provided with a mounting portion 56 that is fastened and fixed to the bulkhead portion 25 of the vehicle frame 5. The mounting portion 56 is formed such that, when viewed in the front-rear direction, it narrows in width from side to side towards the bottom, relative to the rectangular motor case 54 and gear case 55.

[0062] The mounting section 56 comprises an upper wall section 56a, left and right side wall sections 56a1, a middle wall section 56b spaced apart below the upper wall section 56a, and left and right inclined walls 56c extending below the left and right side wall sections 56a1, and is formed in a hollow shape overall. A cushion front connecting section 56d that connects the front end of the rear cushion 32 is provided protruding from above the upper wall section 56a.

[0063] On the left and right sides of the left and right inclined walls 56c (the right side in this embodiment), there are connection terminals 59 for connecting a three-phase cable extending from the PCU 90. The connection terminals 59 are located in a recess 59a formed (on the inside of the mounting portion 56) by cutting out the right inclined wall 56c of the mounting portion 56.

[0064] Figure 13 is a perspective view of the lower part of the mounting section 56. Referring to Figure 13, a stand fixing portion 56e may be provided on one side (left side in this embodiment) of the left and right inclined walls 56c for fastening and fixing a stand bracket (not shown) that supports the side stand. The stand fixing portion 56e is located near the lower fastening portion 58 of the mount portion 56 (the fastening portion to the vehicle frame 5) and shares the strength and rigidity near the lower fastening portion 58. This improves the design freedom of the strength and rigidity of the lower part of the vehicle frame 5 compared to the case where the stand fixing portion 56e is provided on the vehicle frame 5.

[0065] Figure 14 is a perspective view showing a modified example of the connection terminal portion 59 and the recess 59a. As shown in Figure 14, the connection terminal portion 59' and recess 59a' may be provided on the outside of the mounting portion 56 (for example, on the right-side cover of the motor case 54). This is because as the axial thickness of the stator of the electric motor 50 increases, the position of the connection terminal portion 59 and the bearing changes axially outward. By consolidating these points of change on the left and right outer covers of the motor case 54, it becomes easier to accommodate an increase in the repertoire of power units 8 and to reduce costs.

[0066] Referring to Figures 3 to 5, a pair of upper fastening portions 57 are provided at the left and right corners on both sides of the upper part of the mount portion 56, which are fastened to the upper cross member 22. A single lower fastening portion 58 is provided at the lower end of the mount portion 56, which is fastened to the lower cross member 23. Each fastening portion 57, 58 abuts against the fastening portion of the bulkhead portion 25 from the rear and is fastened by bolts running along the front-rear direction. This allows the power unit 8, including the electric motor 50 and reduction gear 51, the pivot shaft 33 of the swing arm 30, and the front end of the rear cushion 32 to be mounted together on the bulkhead portion 25.

[0067] Figure 15 is a perspective view corresponding to the main part of Figure 3 showing a first modified embodiment, Figure 16 is a front view of the rear wheel suspension system 7 of the first modified embodiment, Figure 17 is a right side view of the main part of the first modified embodiment, and Figure 18 is a perspective view of the area around the pivot adjuster 19a of the first modified embodiment. As shown in Figures 15 to 18, the second pivot shaft support portion of the left and right pivot frames 18 may be configured as a separate pivot block 19 from the main body side which makes up the majority of the pivot frame 18. The pivot block 19 is fastened and fixed to the main body side of the pivot frame 18 by bolts running in the front-rear direction. Multiple types of pivot blocks 19 may be provided to allow for the adjustment of the axial position of the pivot shaft 33. In this case, multiple types of pivot adjusters 19a, selected according to the axial position of the pivot shaft 33, are provided on the first pivot shaft support portion of the mount portion 56.

[0068] The front ends of the step brackets 27a on the left and right sides may be fastened and fixed to the left and right pivot blocks 19, for example. The step brackets 27a have a V-shape that protrudes rearward in a side view, and support the step 27 at their rear end so that it can be folded down. The upper and lower front ends of the step brackets 27a abut against the rear end of the pivot block 19 from the left and right outer sides, and are fastened and fixed to each other by bolts running along the left-right direction.

[0069] By making the pivot block 19 and step bracket 27a detachable integrally with the main body of the pivot frame 18, it becomes easier to secure space for attaching and detaching the power unit 8 in vehicles where the power unit 8 is mounted behind the pivot frame 18, and the process of attaching and detaching the power unit 8 becomes easier.

[0070] The lower end of the mounting portion 56 is fastened to the lower cross member 23 at a single point, which has the following effects: By lowering the position of the lower fastening portion 58, the distance between it and the upper fastening portion 57 is increased, the fastening area of ​​the mounting portion 56 (the area surrounded by multiple fastening portions) is widened, and the joint rigidity is increased. At the same time, by making the lower fastening portion 58 the minimum number of points (one), the width of the lower part of the vehicle body close to the ground can be reduced.

[0071] Because the mounting portion 56 is formed with a narrower width from side to side towards the bottom, the left and right pivot frames 18 are also formed with a narrower width from side to side towards the bottom. As a result, the width from side to side at the bottom of the pivot frame 18 is narrowed, ensuring that the vehicle body bank angle is reliably secured. The mounting portion 56 that supports the pivot shaft 33 improves pivot rigidity by increasing rigidity through connection with the vehicle body frame 5, resulting in a configuration suitable for high-output vehicles.

[0072] Figure 19 is a perspective view showing the vehicle body frame 5' of a second modified embodiment, and Figure 20 is a front view of the vehicle body frame 5' of the second modified embodiment. Referring to Figures 19 and 20, it is also conceivable that the vehicle frame 5 is configured to continuously connect from the underside of the head pipe 16 to the front of the left and right pivot frames 18. The vehicle frame 5' shown in Figures 19 and 20 includes a box-shaped section 26 which comprises a pair of left and right side walls 26a extending downward from each of the left and right main frames 17, a bottom wall 26b connecting the lower ends of the left and right side walls 26a, and a front wall 26c connecting the front ends of the left and right side walls 26a. The box-shaped section 26 is used as a support structure for the battery unit 80 mounted between the left and right main frames 17. The box-shaped section 26 increases the rigidity of the vehicle frame 5' on which heavy components (drive system parts) such as the battery unit 80, PCU 90, and power unit 8 are mounted. For example, the outer periphery of the PCU 90 is fixed to the outer periphery of the lower surface of the bottom wall 26b of the box-shaped section 26 by fastening. As a result, the bottom wall 26b is reinforced by the PCU 90, further increasing the rigidity of the vehicle frame 5'.

[0073] As described above, the saddle-type electric vehicle in the above embodiment has a body frame 5 having a head section (head pipe 16) that supports the steering wheels (front wheels 2) in a steerable manner, a pair of left and right main frames 17 that branch off from the head pipe 16 to the left and right and extend to the rear, a pair of left and right pivot frames 18 that extend downward from the rear ends of each of the left and right main frames 17, and upper and lower cross members 22, 23 that connect the left and right pivot frames 18 to each other, and a drive wheel (rear wheel 3) whose front end is supported by the left and right pivot frames 18 and whose rear end is The vehicle comprises a swing arm 30 that supports the swing arm, and a power unit 8 which includes an electric motor 50 for driving the vehicle and is positioned behind the left and right pivot frames 18 in a side view of the vehicle. The power unit 8 includes a unit case 53 that houses at least the electric motor 50, and the unit case 53 includes a mounting portion 56 that is fastened in the front-rear direction of the vehicle to upper and lower cross members 22, 23 between the left and right pivot frames 18, and the pivot axis 33 of the swing arm 30 is supported by the left and right pivot frames 18 and the mounting portion 56.

[0074] This configuration provides the following advantages by equipping the unit case 53 of the power unit 8, which includes the electric motor 50 for vehicle drive, with a mounting portion 56 that is fastened to the vehicle frame 5 in the longitudinal direction of the vehicle. Specifically, the connection between the vehicle frame 5 and the power unit 8 has a structure that can easily withstand the load caused by the input and output of the electric motor 50 (the load associated with the acceleration and deceleration of the vehicle). This reduces (distributes) the load on the fastening portion of the power unit 8, making it easier to adjust the strength and rigidity of the unit case 53 and, consequently, the entire vehicle. By supporting the pivot axis 33 of the swing arm 30 with the left and right pivot frames 18 and the unit case 53, it is possible to optimize the case rigidity by making it easier to adjust the strength and rigidity of the unit case 53 compared to the case where the pivot axis 33 is supported only by the unit case 53.

[0075] In the above-described saddle-type electric vehicle, the cross members 22 and 23 include an upper cross member 22 connecting the upper parts of the left and right pivot frames 18 and a lower cross member 23 connecting the lower parts of the left and right pivot frames 18. The upper part of the mounting portion 56 is provided with an upper fastening portion 57 that is fastened to the upper cross member 22, and the lower part of the mounting portion 56 is provided with a lower fastening portion 58 that is fastened to the lower cross member 23. The lower fastening portion 58 is fastened to the lower cross member 23 in a range that is inward in the vehicle width direction from the upper fastening portion 57.

[0076] With this configuration, the lower fastening portion 58 of the unit case 53 is fastened to the lower cross member 23 in a range that is further inward in the vehicle width direction than the upper fastening portion 57, which makes it possible to narrow the left-right width of the lower part of the unit case 53 as much as possible and makes it easier to secure the bank angle of the vehicle body. In particular, by making the lower fastening portion 58 the minimum number of points at the center in the vehicle width direction, the left-right width of the lower part of the vehicle body close to the ground can be kept to a minimum.

[0077] In the above-described saddle-type electric vehicle, each of the left and right pivot frames 18 is provided with a separate pivot block 19 relative to the main body side of the pivot frame 18, and each of the left and right pivot blocks 19 supports the pivot axis 33 of the swing arm 30 and may be fastened in the front-rear direction of the vehicle to the main body side of the pivot frame 18 on the same side.

[0078] In this configuration, the pivot shaft 33 is supported by a separate pivot block 19 relative to the main body side of the pivot frame 18, and the pivot block 19 is fastened to the main body side of the pivot frame 18 in the vehicle's longitudinal direction. This expands the range of fastening points in the vehicle's longitudinal direction, including the fastening points of the unit case 53, thereby increasing the rigidity of the connection of the unit case assembly, including the pivot block 19 and pivot shaft 33, to the main body side of the vehicle frame 5. The assembly of the pivot block 19, pivot shaft 33, and power unit 8 can be attached together to the main body side of the vehicle frame 5 by fastening in the longitudinal direction.

[0079] In the above-described saddle-type electric vehicle, steps 27 on the same side may be attached to each of the left and right pivot blocks 19. With this configuration, the step 27 is supported by the left and right pivot blocks 19, allowing the step load to be received by the high-strength pivot blocks 19. As a result, the vehicle frame 5 is not affected by the strength requirements of the step mounting section, making it easier to adjust the strength and rigidity of the main body of the vehicle frame 5.

[0080] In the above-described saddle-type electric vehicle, multiple types of left and right pivot blocks 19 may be provided, each with a different axial center position of the pivot axis 33. With this configuration, by setting up multiple types of pivot blocks 19 with different center positions of the pivot axis 33, the pivot position can be easily varied by replacing the pivot block 19, thereby increasing the versatility of vehicle parts.

[0081] In the above-described saddle-type electric vehicle, a rear cushion 32 is provided which is connected to the swing arm 30 via a link mechanism 31. The rear cushion 32 is positioned above the power unit 8 with its stroke direction facing the front-rear direction of the vehicle, its front end connected to the power unit 8 in front of the drive shaft 50a of the electric motor 50, and its rear end connected to the swing arm 30 behind the drive shaft 50a of the electric motor 50.

[0082] In this configuration, the rear cushion 32 is positioned to extend in the longitudinal direction of the vehicle, straddling the drive shaft 50a of the electric motor 50. The front end of the rear cushion 32 is connected to the power unit 8, and the rear end of the rear cushion 32 is connected to the swing arm 30 via a link mechanism 31. By connecting the front end of the rear cushion 32 to the part where the rigidity is increased by fastening the vehicle frame 5 and the power unit 8, the front end of the rear cushion 32 can be supported with high rigidity without providing additional reinforcement at the connection point of the front end of the rear cushion 32. Since the rear cushion 32 extends in the longitudinal direction of the vehicle, straddling the drive shaft 50a of the electric motor 50 above the power unit 8, it is possible to efficiently secure the stroke amount of the rear cushion 32 while avoiding the power unit 8 located behind the pivot frame 18, and compared to the case where the rear cushion 32 is positioned between the power unit 8 and the rear wheel, the rearward movement of the rear wheel 3 and consequently the increase in the wheelbase can be suppressed. The front end of the rear cushion 32 can also be connected to the vehicle frame 5 instead of the power unit 8. In other words, the cushion front connecting portion 56d can also be provided on the upper cross member 22, etc.

[0083] In the above-described saddle-type electric vehicle, the swing arm 30 comprises a pair of left and right arm bodies 36 and an arm connecting portion 37 that connects the left and right arm bodies 36 to each other. The left and right arm bodies 36 are curved so as to be convex upward when viewed from the side of the vehicle, the arm connecting portion 37 connects the upper ends of the left and right arm bodies 36, and a link mechanism 31 that connects the rear end of the rear cushion 32 to the swing arm 30 is arranged inside the arm connecting portion 37.

[0084] In this configuration, the left and right arm bodies 36 of the swingarm 30 are bent in an upward convex shape, and the upper ends of the left and right arm bodies 36 are connected by an arm connecting portion 37. Since the arm connecting portion 37 is positioned towards the upper part of the swingarm 30, it efficiently connects the left and right arm bodies 36 while avoiding the power unit 8 behind the pivot frame 18, and also makes it easier to connect the rear end of the rear cushion 32 which is positioned above the power unit 8. A link mechanism 31 for connecting the rear end of the rear cushion 32 is positioned inside the arm connecting portion 37, so the link mechanism 31 increases the degree of freedom in setting the suspension characteristics and allows for a compact link-type rear suspension configuration.

[0085] In the above-described saddle-type electric vehicle, the vehicle frame 5' may include a box-shaped section 26 comprising a pair of left and right side wall sections 26a extending downward from each of the left and right main frames 17, a bottom wall section 26b connecting the lower ends of the left and right side wall sections 26a, and a front wall section 26c connecting the front ends of the left and right side wall sections 26a.

[0086] With this configuration, a box-shaped section 26, including left and right side walls 26a, a bottom wall 26b, and a front wall 26c, is provided below the left and right main frames 17 of the vehicle body frame 5'. This allows the box-shaped section 26 to be used as a support structure for the battery unit 80 mounted between the left and right main frames 17. This reduces the number of parts by eliminating or simplifying the structure for supporting the battery unit 80, and also increases the rigidity of the vehicle body frame 5' on which the heavy battery unit 80 is mounted by the box-shaped section 26.

[0087] In the above-described saddle-type electric vehicle, a control device (PCU90) for controlling the drive of the electric motor 50 is provided, and the PCU90 may be fastened to the lower surface of the bottom wall portion 26b of the box-shaped portion 26. With this configuration, by fastening the PCU90 to the lower surface of the box-shaped portion 26 of the vehicle frame 5', the structure for supporting the PCU90 can be eliminated or simplified, thereby reducing the number of parts. At the same time, the bottom wall portion 26b of the box-shaped portion 26 is reinforced by the fastening of the PCU90, further increasing the rigidity of the vehicle frame 5'.

[0088] In the above-described saddle-type electric vehicle, the electric motor 50 may be positioned at a height that overlaps with the PCU 90 when viewed from the front-rear direction of the vehicle. With this configuration, the PCU 90 and the electric motor 50 are positioned at heights that overlap each other, which not only brings the battery unit 80 mounted inside the box-shaped section 26 and the PCU 90 closer together, but also brings the PCU 90 and the electric motor 50 closer together. This shortens the power lines between the battery unit 80, PCU 90 and the electric motor 50, and also concentrates mass by concentrating heavy components.

[0089] In the above-described saddle-type electric vehicle, the electric motor 50 and the drive wheel (rear wheel 3) are connected via an endless transmission member (drive chain 73), and a tensioner 75 that applies tension to the drive chain 73 may be supported in the unit case 53 of the power unit 8. With this configuration, by supporting the tensioner 75 for the drive chain 73 in the unit case 53, tension can be efficiently applied to the drive chain 73 in the vicinity of the power unit 8.

[0090] It should be noted that the present invention is not limited to the above embodiments, and for example, the configuration of this embodiment may be applied to saddle-type vehicles other than two-wheeled vehicles. The saddle-type vehicles include all vehicles on which the driver straddles the vehicle body, and include not only motorcycles (including motorized bicycles and scooter-type vehicles) but also three-wheeled vehicles (including vehicles with one front wheel and two rear wheels, as well as vehicles with two front wheels and one rear wheel) or four-wheeled vehicles (such as four-wheeled buggies). Furthermore, the configuration in the above embodiment is just one example of the present invention, and various modifications are possible without departing from the spirit of the invention, such as replacing the components of the embodiment with well-known components. [Explanation of Symbols]

[0091] 1. Electric two-wheeled vehicle (saddle-type electric vehicle) 2 Front wheels (steering wheels) 3 drive wheels 3. Rear wheels (drive wheels) 5.5' frame 8 Power Units 16. Head pipe (head section) 17 Mainframe 18 Pivot Frame 19 Pivot Block 22 Upper cross member (cross member) 23 Lower cross member (cross member) 26 Box-shaped section 26a Side wall part 26b Bottom wall 26c Front wall 27 steps 30 Swingarm 31 Link mechanism 32 Rear cushion 33 Pivot Axis 36 Arm section 37 Arm connection section 50 Electric motors 50a Drive shaft 53 Unit Case 56 Mounting section 56d Cushion front connecting part 57 Upper fastening part 58 Lower fastening section 73. Drive chain (transmission component) 75 Tensioner 80 batteries 90 PCU (Control Unit)

Claims

1. A vehicle body frame (5) having a head portion (16) that supports the steering wheels (2) in a steerable manner, a main frame (17) extending rearward from the head portion (16), a pair of left and right pivot frames (18) extending downward from the rear end of the main frame (17), and cross members (22, 23) connecting the left and right pivot frames (18) to each other, A swing arm (30) that supports the drive wheel (3), The vehicle includes an electric motor (50) for driving the vehicle and a power unit (8) positioned behind the pivot frame (18) in a side view of the vehicle, The power unit (8) includes a unit case (53) that houses the electric motor (50), The unit case (53) is provided with a mounting portion (56) that is fastened to the cross members (22, 23) in the vehicle longitudinal direction between the left and right pivot frames (18), The pivot axis (33) of the swing arm (30) is supported by the left and right pivot frames (18) and the mounting portion (56) in a saddle-type electric vehicle.

2. The cross members (22, 23) include an upper cross member (22) that connects the upper parts of the left and right pivot frames (18), and a lower cross member (23) that connects the lower parts of the left and right pivot frames (18). The upper part of the mounting portion (56) is provided with an upper fastening portion (57) that is fastened to the upper cross member (22), The lower part of the mounting portion (56) is provided with a lower fastening portion (58) that is fastened to the lower cross member (23), The saddle-type electric vehicle according to claim 1, wherein the lower fastening portion (58) is fastened to the lower cross member (23) in a range that is more inward in the vehicle width direction than the upper fastening portion (57).

3. Each of the left and right pivot frames (18) is provided with a separate pivot block (19) relative to the main body side of the pivot frame (18). The saddle-type electric vehicle according to claim 1 or 2, wherein each of the left and right pivot blocks (19) supports the pivot shaft (33) of the swing arm (30) and is fastened in the front-rear direction of the vehicle to the main body side of the pivot frame (18) on the same side on both the left and right sides.

4. The saddle-type electric vehicle according to claim 3, wherein each of the left and right pivot blocks (19) is fitted with a step (27) on the same side on both sides.

5. The saddle-type electric vehicle according to claim 3, wherein the left and right pivot blocks (19) are set to be of multiple types with different axial center positions of the pivot shaft (33).

6. The rear cushion (32) is connected to the swing arm (30), The saddle-type electric vehicle according to claim 3, wherein the rear cushion (32) is positioned above the power unit (8) in a posture with its stroke direction facing the front-rear direction of the vehicle, its front end is connected to the vehicle frame (5) or the power unit (8) in front of the drive shaft (50a) of the electric motor (50), and its rear end is connected to the swing arm (30) in rear of the drive shaft (50a) of the electric motor (50).

7. The swing arm (30) comprises a pair of left and right arm bodies (36) and an arm connecting portion (37) that connects the left and right arm bodies (36) to each other. The left and right arm bodies (36) are bent so as to be convex upward when viewed from the side of the vehicle. The arm connecting portion (37) connects the upper ends of the left and right arm bodies (36), A saddle-type electric vehicle according to claim 6, wherein a link mechanism (31) is arranged inside the arm connecting portion (37) to connect the rear end of the rear cushion (32) and the swing arm (30).

8. The saddle-type electric vehicle according to claim 3, wherein the vehicle body frame (5) comprises a box-shaped section (26) including a pair of left and right side wall sections (26a) extending downward from each of the left and right main frames (17), a bottom wall section (26b) connecting the lower ends of the left and right side wall sections (26a), and a front wall section (26c) connecting the front ends of the left and right side wall sections (26a).

9. The system includes a control device (90) that controls the drive of the electric motor (50), The saddle-type electric vehicle according to claim 8, wherein the control device (90) is fastened to the lower surface of the bottom wall portion (26b) of the box-shaped portion (26).

10. The saddle-type electric vehicle according to claim 3, wherein the electric motor (50) is positioned at a height that overlaps with the control device (90) when viewed from the front-rear direction of the vehicle.

11. The electric motor (50) and the drive wheel (3) are connected via an endless transmission member (73), A tensioner (75) that applies tension to the transmission member (73) is supported in the unit case (53) of the power unit (8), as described in claim 3.

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