Straddle 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 saddle-riding type electric vehicle.

Background Art

[0002] In a saddle-riding type electric vehicle that runs on the output of an electric motor, there are various arrangements of the battery for vehicle running, the control device, and the electric motor. For example, in Patent Document 1, a plurality of batteries are arranged side by side in the vertical direction between the left and right main frames, the control device is arranged between the battery and the pivot shaft, and the electric motor is arranged behind the pivot shaft of the swing arm. The front part of the motor case is fastened to the battery case and supports the front end part of the swing arm. For example, in Patent Document 2, a battery is arranged between the left and right main frames, the control device is arranged below the battery, and the electric motor is arranged in front of the pivot frame. The motor case is fastened to the pivot frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the above, when the electric motor is arranged behind the pivot shaft and the swing arm is supported by the motor case, the motor case receives the load related to the input and output of the electric motor and the load from the swing arm, so excessive rigidity is required. In this case, considering the balance with the main frame at the front part of the vehicle body, the adjustment of the strength and rigidity of the motor case becomes complicated. In particular, in a saddle-type electric vehicle which is a small vehicle, since the layout of heavy drive components such as a battery, a control device, and an electric motor has a great influence on the frame rigidity and thus the vehicle body design, there has been room for consideration.

[0005] Therefore, an object of the present invention is to provide a saddle-type electric vehicle capable of suppressing the influence on the vehicle body design due to the layout of drive components.

Means for Solving the Problems

[0006] As a means for solving the above problems, a first aspect of the present invention includes a head portion (16) that supports a steering wheel (2) so as to be steerable, a main frame (17) that extends rearward from the head portion (16), a pair of left and right pivot frames (18) that extend downward from the rear end portion of the main frame (17), and cross members (22, 23) that connect the left and right pivot frames (18) to each other, a vehicle body frame (5); a swing arm (30) that supports a drive wheel (3); and a power unit (8) that includes an electric motor (50) for driving the vehicle and is disposed rearward of 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), and the unit case (53) includes a mount portion (56) that is fastened in the vehicle longitudinal direction to the cross members (22, 23) 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). According to this configuration, by providing a mount portion on the unit case of the power unit including the electric motor for vehicle drive, which is fastened to the vehicle body frame in the longitudinal direction of the vehicle, the following effects can be obtained. That is, the connecting portion between the vehicle body frame and the power unit has a structure that can easily receive the load due to the input and output of the electric motor (the load accompanying the acceleration and deceleration of the vehicle). Therefore, the load on the fastening portion of the power unit can be reduced (dispersed), and the adjustment of the strength and rigidity of the unit case and thus the entire vehicle body can be facilitated. By supporting the pivot shaft of the swing arm with the left and right pivot frames and the unit case, compared with the case where the pivot shaft is supported only by the unit case, the adjustment of the strength and rigidity of the unit case can be facilitated and the optimization of the case rigidity can be achieved.

[0007] The second aspect of the present invention is, in the above first aspect, the cross members (22, 23) include an upper cross member (22) connecting between the upper parts of the left and right pivot frames (18), and a lower cross member (23) connecting between the lower parts of the left and right pivot frames (18). An upper fastening portion (57) fastened to the upper cross member (22) is provided at the upper part of the mount portion (56), and a lower fastening portion (58) fastened to the lower cross member (23) is provided at the lower part of the mount portion (56). The lower fastening portion (58) is fastened to the lower cross member (23) within a range closer to the vehicle width direction inner side than the upper fastening portion (57). According to this configuration, since the lower fastening portion of the unit case is fastened to the lower cross member within a range closer to the vehicle width direction inner side than the upper fastening portion, the left and right width of the lower part of the unit case can be narrowed as much as possible, and it can be easier to secure the bank angle of the vehicle body.

[0008] The third aspect of the present invention is, in the above first or second aspect, each of the left and right pivot frames (18) includes a pivot block (19) separate from the main body side of the pivot frame (18). Each of the left and right pivot blocks (19) supports the pivot shaft (33) of the swing arm (30) and is fastened in the longitudinal direction of the vehicle to the main body side of the left and right same-side pivot frames (18). According to this configuration, the pivot shaft is supported by a pivot block separate from the pivot frame body, and the pivot block is fastened to the pivot frame body in the vehicle longitudinal direction. Together with the fastening portion of the unit case, the range of the fastening portion in the vehicle longitudinal direction is widened, and the coupling rigidity of the unit case assembly including the pivot block and the pivot shaft to the main body side of the vehicle body frame can be increased. The assembly of the pivot block, the pivot shaft, and the power unit can be collectively attached to the main body side of the vehicle body frame by fastening in the longitudinal direction.

[0009] In a fourth aspect of the present invention, in the third aspect described above, steps (27) on the same left and right sides are attached to each of the left and right pivot blocks (19). According to this configuration, by supporting the steps with the left and right pivot blocks, the step load can be received by the high-strength pivot blocks. Therefore, it is possible to easily adjust the strength and rigidity on the main body side of the vehicle body frame.

[0010] In a fifth aspect of the present invention, in the third or fourth aspect described above, a plurality of types of left and right pivot blocks (19) are set with different axial center positions of the pivot shaft (33). According to this configuration, by setting a plurality of types of pivot blocks with different center positions of the pivot shaft, the pivot position can be easily made variable by exchanging the pivot blocks, and the versatility of vehicle parts can be enhanced.

[0011] In a sixth aspect of the present invention, in any one of the first to fifth aspects described above, a rear cushion (32) connected to the swing arm (30) is provided. The rear cushion (32) is disposed above the power unit (8) with the stroke direction facing the vehicle longitudinal direction. The front end portion is connected to the vehicle body frame (5) or the power unit (8) in front of the drive shaft (50a) of the electric motor (50), and the rear end portion is connected to the swing arm (30) behind the drive shaft (50a) of the electric motor (50). According to this configuration, the rear cushion is arranged to extend in the longitudinal direction of the vehicle across the drive shaft of the electric motor. The front end of the rear cushion is connected to the vehicle body frame or the power unit, and the rear end of the rear cushion is connected to the swing arm. By connecting the front end of the rear cushion to a portion where the vehicle body frame and the power unit are fastened together to enhance rigidity, the front end of the rear cushion can be supported with high rigidity without separately providing reinforcement at the connecting portion of the front end of the rear cushion. Since the rear cushion extends in the longitudinal direction of the vehicle across 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 arranged behind the pivot frame, and to suppress the rearward movement of the rear wheels and thus the increase in the wheelbase compared to the case where the rear cushion is arranged between the power unit and the rear wheels.

[0012] The seventh aspect of the present invention is, in the sixth aspect described above, that the swing arm (30) includes a pair of left and right arm bodies (36) and an arm connecting portion (37) that connects the left and right arm bodies (36). The left and right arm bodies (36) are bent so as to be convex upward in a side view of the vehicle, the arm connecting portion (37) connects between the upper end portions of the left and right arm bodies (36), and inside the arm connecting portion (37), a link mechanism (31) that connects the rear end portion of the rear cushion (32) and the swing arm (30) is arranged. According to this configuration, the left and right arm bodies of the swing arm are formed in a convex upward bent shape, and the upper end portions of the left and right arm bodies are connected by the arm connecting portion. Since the arm connecting portion is arranged closer to the upper side of the swing arm, it is possible to efficiently connect the left and right arm bodies while avoiding the power unit behind the pivot frame, and it becomes easier to connect the rear end portion of the rear cushion arranged above the power unit. Since a link mechanism for connecting the rear end portion of the rear cushion is arranged inside the arm connecting portion, the degree of freedom in setting the suspension characteristics can be increased by the link mechanism, and the link type rear suspension can be configured compactly.

[0013] The eighth aspect of the present invention is that, in any one of the first to seventh aspects above, the vehicle body frame (5) includes 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), and a front wall portion (26c) connecting the front ends of the left and right side wall portions (26a), and is provided with a box-shaped portion (26). According to this configuration, by providing a box-shaped portion including left and right side wall portions, a bottom wall portion, and a front wall portion below the left and right main frames of the vehicle body frame, it can be used as a support structure for the battery mounted between the left and right main frames. As a result, the structure for supporting the battery can be deleted or simplified to reduce the number of parts, and the rigidity of the vehicle body frame on which the heavy battery is mounted can be increased by the box-shaped portion.

[0014] The ninth aspect of the present invention is that, in the eighth aspect above, it is provided with a control device (90) for controlling the drive of the electric motor (50), and the control device (90) is fastened to the lower surface of the bottom wall portion (26b) of the box-shaped portion (26). According to this configuration, by fastening the control device to the lower surface of the box-shaped portion of the vehicle body frame, the structure for supporting the control device can be deleted or simplified to reduce the number of parts, and the bottom wall portion of the box-shaped portion is reinforced by the fastening of the control device, and the rigidity of the vehicle body frame can be further increased.

[0015] The tenth aspect of the present invention is that, in any one of the first to ninth aspects above, when viewed in the vehicle longitudinal direction, the electric motor (50) is arranged at a height overlapping the control device (90). According to this configuration, by arranging the control device and the electric motor at a height where they overlap each other, not only the battery mounted inside the box-shaped portion and the control device are brought closer to each other, but also the control device and the electric motor are brought closer to each other, thereby shortening the power lines between the battery, the control device, and the electric motor, and concentrating the mass by concentrating the arrangement of heavy objects.

[0016] In the eleventh aspect of the present invention, in any one of the first to tenth aspects, the electric motor (50) and the drive wheel (3) are connected via an endless transmission member (73), and a tensioner (75) for applying 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, it is possible to efficiently apply tension 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-riding type electric vehicle capable of suppressing the influence on the vehicle body design due to the layout of the driving parts.

Brief Description of the Drawings

[0018]

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Mode for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the directions such as front, rear, left, and right are the same as those in the vehicle described below unless otherwise specified. Also, in the figures used in the following description, an arrow FR indicating the front of the vehicle, an arrow LH indicating the left side of the vehicle, an arrow UP indicating the upper side of the vehicle, and a line CL indicating the center of the vehicle body left and right are shown at appropriate positions.

[0020] FIG. 1 is a left side view of an electric two-wheeler (saddle-riding type electric vehicle) 1 according to an embodiment. As shown in FIG. 1, the electric two-wheeler 1 according to the embodiment is an on-road type saddle-riding type electric vehicle, and aims to reduce the size and weight of the vehicle body, concentrate the mass, and lower the center of gravity. The electric two-wheeler 1 includes a front wheel 2, a rear wheel 3, a front wheel suspension system 4, a vehicle body frame 5, a vehicle body cover 6, a rear wheel suspension system 7, a power unit 8, a battery unit 80, and a PCU (control device) 90.

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

[0022] FIG. 2 is a left side view of the main part of the electric two-wheeler 1, FIG. 3 is a perspective view of the rear wheel suspension system 7 and the power unit of the electric two-wheeler 1, and FIG. 4 is a perspective view further showing the vehicle body frame 5 in FIG. 3. Referring to FIGS. 1, 2, and 4, the vehicle body frame 5 includes 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 of the vehicle body and is provided singly at the front end of the vehicle body frame 5. The head pipe 16 rotatably supports the stem pipe by inserting it. The head pipe 16 is not limited to a cylindrical shape, and appropriate concavities, convexities, openings, etc. may be formed as appropriate.

[0024] A pair of main frames 17 branch out left and right from the upper part of the head pipe 16 and extend rearward and downward. The front parts of the pair of main frames 17 obliquely extend rearward and outward in the vehicle width direction behind the head pipe 16 in a plan view seen from above, and then curve and extend rearward. The rear parts of the pair of main frames 17 linearly extend along the front-rear direction in a plan view seen from above. The front parts of the pair of main frames 17 have an up-down width equivalent to the axial length of the head pipe 16 in a side view. The rear parts of the pair of main frames 17 are formed so that the up-down width becomes narrower toward the rear and downward in a side view.

[0025] A pair of pivot frames 18 extend downward from the rear end parts of the main frames 17 on the same side left and right respectively. A pivot shaft 33 extending in the vehicle width direction is installed between the intermediate parts near the upper part in the up-down direction in the pair of pivot frames 18. Note that "intermediate" used in the embodiment means not only the center between both ends of the object but also the range inside between both 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 in the vehicle width direction of the upper cross member 22, a pair of left and right upper fastening parts 22a for fastening the upper part of the mount part 56 of the unit case 53 of the power unit 8 are provided.

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

[0028] Referring to FIG. 1, the vehicle body frame 5 further includes a rear frame 24 that supports the seat 9 for the occupant to sit on. The rear frame 24 is detachably fixed, for example, by bolt fastening or the like, with its front end portion on the upper side of the rear portion of the left and right main frames 17. A step bracket 27a that supports the left and right steps 27 is detachably fixed by bolt fastening to the rear portions of the left and right pivot frames 18.

[0029] FIG. 5 is a front view of the main part of FIG. 4 as seen from the front, FIG. 6 is a perspective view of the configuration of FIG. 2 as seen from the obliquely upper rear side, and FIG. 7 is a perspective view of the vehicle body frame 5 as seen from the obliquely upper rear. Referring to FIGS. 1, 2, and 6, the vehicle body frame 5 mounts a battery unit 80 for running between the left and right main frames 17 behind the head pipe 16 and in front of the left and right pivot frames 18. The battery unit 80 is insertable and removable from above within a 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 body frame 5 supports a power unit 8 for vehicle running behind the left and right pivot frames 18. The power unit 8 includes an electric motor 50 and a speed reducer 51, and houses these electric motor 50 and speed reducer 51 in an integrated unit case 53. The power unit 8 is fastened and fixed to the bulkhead portion 25 formed by the left and right pivot frames 18 and the upper and lower cross members 22, 23 in the vehicle body frame 5 from the rear side of the vehicle. Even with a configuration in which the power unit 8 is supported behind the left and right pivot frames 18, by arranging the battery unit 80 closer to the head pipe 16, the front-rear weight distribution can be optimized.

[0031] Referring to FIG. 1, the vehicle body cover 6 covers the vehicle body frame 5 and the like. The vehicle 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 range extending from the front of the head pipe 16 to the left and right sides, and the left and right side portions further extend rearward to cover the side portions of the vehicle body from the outside in the vehicle width direction. The rear cowl 42 covers the range extending rearward from the left and right side portions of the rear frame 24. The seat 9 is disposed on the rear cowl 42.

[0032] The seat front cover 43 is formed so as to bulge upward the space between the left and right main frames 17 in front of the seat 9. The seat front cover 43 is shaped like a tank cover that mimics a fuel tank. The seat front cover 43 forms a knee grip portion that is sandwiched between the knees of the occupant sitting on the seat 9. The upper part of the battery unit 80 is accommodated inside the seat front cover 43. The seat front cover 43 covers the upper part of the battery unit 80 from above. The under cowl 44 is continuous with the lower part of the front cowl 41 and covers the lower part of the vehicle body from below.

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

[0034] The link mechanism 31 includes a link arm 34 extending in the vertical direction and a link member 35 having an inverted triangular shape in side view. The link arm 34 is disposed inside an upward protruding portion (arm connection portion 37) formed at the front upper part of the swing arm 30 in side view. The link arm 34 extends downward from the inside of the upward protruding portion, and the lower end portion is rotatably connected to a link connection portion 53a at the rear end portion of the unit case 53. The upper end portion of the link arm 34 is rotatably connected to the rear end top portion of the link member 35. The front end top portion of the link member 35 is rotatably connected to the upward protruding portion of the swing arm 30. The rear end portion of the cushion unit 32 is rotatably connected to the lower end top portion of the link member 35. The front end portion of the cushion unit 32 is rotatably connected to a cushion front connection portion 56d of the mount portion 56. Due to the action of the link mechanism 31, a progressive effect can be obtained, such that the cushion stroke is reduced when the rear load is small and the swing of the swing arm 30 is small, and the cushion stroke is increased when the rear load is large and the swing of the swing arm 30 is large.

[0035] The rear cushion 32 is provided inside the vehicle width direction at the rear part of the vehicle body (for example, on the vehicle body left - right center CL). The rear cushion 32 is formed in a cylindrical shape with a compression coil spring disposed on the outer periphery of the damper cylinder, and is arranged in a horizontal posture with its axial direction generally along the vehicle front - rear direction. The rear cushion 32 is disposed above the power unit 8 and extends in the front - rear direction. The cushion front connection portion 56d connecting the front end portion of the rear cushion 32 is located near the upper fastening portion 57 (the fastening portion to the vehicle body frame 5) of the mount portion 56 and shares the strength and rigidity near the upper fastening portion 57.

[0036] The rear cushion 32 is set such that the angle θ (the angle of the central axis) with respect to the vertical line VL in a side view, for example, is in the range of 45 degrees to 120 degrees. The rear cushion 32 is arranged so as to be accommodated within the vertical width of the swing arm 30. The rear cushion 32 is arranged substantially horizontally while avoiding the large-diameter electric motor 50 arranged behind the pivot frame 18. Thereby, without the arrangement of the rear cushion 32 affecting the wheelbase, the stroke amount of the rear cushion 32 and thus the damper capacity are ensured. By suppressing the vertical height of the arrangement position of the rear cushion 32, the space under the seat becomes available, and it can also be applied to vehicles with a low seat height.

[0037] The power unit 8 includes an electric motor 50 for driving the vehicle, a speed reducer 51 (not shown) that reduces the output of the electric motor 50, an output shaft 70 that outputs the power of the electric motor 50 decelerated by the speed reducer 51, and a unit case 53 that houses the drive parts such as the electric motor 50 and the speed reducer 51. The power unit 8 is configured as an integrated unit including the electric motor 50, the speed reducer 51, the output shaft 70, and the unit case 53.

[0038] The electric motor 50 is arranged such that the axial direction of its drive shaft (motor drive shaft) 50a is along the vehicle width direction. A gear type speed reducer 51 is arranged on one side (left side) in the left-right direction of the electric motor 50. The output shaft 70 extends in the vehicle width direction, and its left end portion 70a protrudes outside the unit case 53. The output shaft 70 is located on the upper front side of the motor drive shaft 50a in a side view. In the power unit 8, the output shaft 70 and the motor drive shaft 50a are provided on separate axes from each other. Depending on the configuration of the speed reducer 51 and the like, the output shaft 70 and the motor drive shaft 50a may be provided coaxially with each other.

[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 is disposed on the left side portion of the motor case 54 and houses the speed reducer 51, and a mount portion 56 provided at the front portion of the unit case 53.

[0040] Referring to FIG. 8, the left end portion 70a of the output shaft 70 protrudes outside the unit case 53, and the left end portion 70a and the rear wheel 3 are connected via a chain type transmission mechanism 74. Reference numeral 71 in the figure denotes a drive sprocket attached to the left end portion 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 wound around both sprockets 71 and 72.

[0041] A tensioner 75 that applies tension to the drive chain 73 is supported below the unit case 53 of the power unit 8. The tensioner 75 brings a tensioner pulley 76 into contact with the drive chain 73 from the outer peripheral side of the winding region of the drive chain 73 in a side view. The tensioner pulley 76 is supported on the left side of the rear portion of the unit case 53 via a tensioner arm 77.

[0042] The tensioner arm 77 extends rearward along the lower side (slack side) of the drive chain 73 in a side view, and supports the tensioner pulley 76 at the rear end portion. The front end portion of the tensioner arm 77 is rotatably supported by the unit case 53, and the rear end portion is biased upward (toward the drive chain 73). The tensioner 75 brings the tensioner pulley 76 into contact with the drive chain 73 with an urging force, and applies 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 portion 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. Thereby, tension can be efficiently applied to the drive chain 73 with a small force. In the embodiment, the chain type transmission mechanism 74 is illustrated, but a belt type transmission mechanism may also be used. The tensioner 75 can be configured to correspond to transmission components such as the drive chain 73 and the drive belt.

[0043] Referring to FIG. 1, below the power unit 8, a PCU (Power Control Unit) 90 for controlling the electric motor 50 is arranged. The PCU 90 is a control device including a PDU (Power Drive Unit) which is a motor driver and an ECU (Electric Control Unit) for controlling the PDU. The PDU includes an inverter, converts the current supplied from the battery unit 80 from direct current to alternating current, and supplies power to the electric motor 50.

[0044] The PCU 90 is housed in a PCU cover 91 formed in a rectangular parallelepiped shape so as to be continuous with the lower part of the battery case 81. By providing the PCU cover 91, it is possible to suppress disturbances from reaching the PCU 90, and it is difficult for the operating noise generated by the PCU 90 to spread to the surroundings. The PCU cover 91 may be attached with a sound-absorbing material, or the cover itself may be formed of a sound-absorbing material. The lower end of the PCU 90 is at the same height as the lower end of the vehicle body frame 5 (the lower end of the lower cross member 23 in the embodiment). The periphery of the PCU 90 is covered from below by an under cowl 44 that is continuous with the lower part of 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 at 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, 23. The bulkhead portion 25 may have, for example, a wall that closes the opening portion. In this case, it is possible to make it difficult for the operating noise of the power unit 8 to reach the front (the passenger side).

[0046] The power unit 8 is arranged such that most of it excluding the mounting portion 56 is located behind the left and right pivot frames 18 in a side view. The upper part of the power unit 8 is arranged to enter inside the front part of the swing arm 30 (between the front parts of the left and right arm bodies 36) in a side view. The rear wheel suspension system 7 in FIGS. 8 and 9 shows the posture when in the unloaded 1G state (stationary state with vehicle weight applied). The lower end of the power unit 8 is at the same height as the lower end of the vehicle 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 penetrates and supports the pivot shaft 33. Since the pivot shaft 33 penetrates through it, the first pivot shaft support portion is arranged at a position avoiding the electric motor 50 in a side view. For this reason, the first pivot shaft support portion is located outside the unit case 53 in a side view. From the viewpoint of avoiding an increase in the size of the unit case 53, it is difficult to adopt a large structure capable of ensuring strength and rigidity independently. In the embodiment, by fastening the mounting portion 56 to the bulkhead portion 25, the strength and rigidity of the first pivot shaft support portion are ensured. Also, the pivot shaft 33 is supported by the mounting portion 56 and, in addition, the left and right side portions are respectively supported by the left and right pivot frames 18. Thereby, while enhancing the pivot rigidity of the swing arm 30, an increase in the size of the unit case 53 can be suppressed. The pivot shaft support portion in the left and right pivot frames 18 is referred to as the second pivot shaft support portion.

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

[0049] The battery unit 80 is arranged such that, in side view, its upper part protrudes above the main frame 17 and its lower part protrudes below the main frame 17. The part of the battery unit 80 that protrudes above the main frame 17 is covered from above by the seat front cover 43. On the outer side in the vehicle width direction of the battery unit 80, the main frame 17 is arranged so as to diagonally cross it. The part of the battery unit 80 that protrudes below the main frame 17 is covered from the left and right outer sides by the rear side portions (side cowls) of both sides of the front cowl 41.

[0050] Below the battery unit 80, the PCU 90 is arranged so as to be continuous. Thereby, the length of the high-voltage cables (positive electrode cable and negative electrode cable) extending from the battery unit 80 is suppressed. Behind the PCU 90, the power unit 8 is arranged so as to be adjacent in the front-rear direction. The PCU 90 and the power unit 8 are arranged so as to overlap each other in the vertical direction and the left-right direction when viewed from the front-rear direction. Thereby, the length of the power line (three-phase cable) between the PCU 90 and the power unit 8 is suppressed.

[0051] The PCU 90 is arranged in front of the bulkhead portion 25 and installed below the battery unit 80. Thereby, even if the PCU 90 becomes larger due to the higher output of the electric motor 50, it is avoided that the PCU 90 affects the fastening portion between the power unit 8 and the vehicle body frame 5. Thereby, it is possible to suppress the influence on the rigidity of the vehicle body frame 5 and improve the degree of freedom in vehicle body design. Compared with the case where the PCU 90 is arranged behind the bulkhead portion 25, the retreat of the rear wheel 3 and thus the increase in the wheelbase are suppressed.

[0052] FIG. 10 is a front view of the swing arm, FIG. 11 is a rear view of the swing arm, and FIG. 12 is a top view of the swing arm. Referring to FIGS. 10 to 12, the swing arm 30 includes a pair of left and right arm bodies 36 and an arm connecting portion 37 that connects the front portions of the left and right arm bodies 36 to each other. The left and right arm bodies 36 have a bent shape that bulges upward in side view. The left and right arm bodies 36 extend with, for example, a rectangular hollow cross-sectional shape along the bent shape in side view. At the front end of the left and right arm bodies 36, a cylindrical pivot support portion 38 through which the pivot shaft 33 is inserted is provided. At the rear end of the left and right arm bodies 36, a plate-shaped axle support portion 39 through which the rear wheel axle 3a is inserted is provided.

[0053] The upper end (top) of the left and right arm bodies 36 in side view is located in front 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 in side view. The inside of the arm connecting portion 37 is appropriately hollowed out, and the rear portion of the rear cushion 32 and the link mechanism 31 are accommodated inside this arm connecting portion 37.

[0054] The upper part of the power unit 8 is disposed between the front portions of the left and right arm bodies 36. Since the rear wheel 3 is disposed in proximity to the rear of the power unit 8, the arm connecting portion 37 between the left and right arm bodies 36 is provided so as to bypass above the proximity portion between the power unit 8 and the rear wheel 3. Inside the arm connecting portion 37, the rear end portion of the rear cushion 32 is connected to the link mechanism 31. The front end portion of the rear cushion 32 is connected to a cushion front connecting portion 56d on the mount portion 56 of the power unit 8.

[0055] In side view, a straight line connecting the center 33c of the pivot shaft 33 and the center 3c of the rear wheel axle 3a is indicated by reference numeral T1. The arm connecting portion 37 is located above the straight line T1 in side view. The center 50c of the motor drive shaft 50a of the power unit 8 is located below the straight line T1. The center 70c of the output shaft 70 is located below the straight line T1, but is disposed closer to the straight 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 shaft 33. The lower edge of the swing arm 30 in side view is formed below the straight line T1 and substantially parallel to the straight line T1.

[0056] The swing arm 30 is provided with arm plate portions 36a that close a triangular range in side view below each of the left and right arm bodies 36. In the swing arm 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 the same thickness as the outer wall portions on the outer side in the vehicle width direction of the arm bodies 36 on the left and right same sides. The outer surfaces of the left and right arm plate portions 36a are formed flush with the outer surfaces of the outer wall portions on the outer side in the vehicle width direction of the arm bodies 36 on the left and right same sides. The swing arm 30 has an arm shape that seemingly increases the vertical height in side view, but the skeleton part is the left and right arm bodies 36 with a bent shape.

[0057] Since the lower part of the left and right arm bodies 36 is the plate-like left and right arm plate portions 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 it is difficult for the left and right arm plate portions 36a 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 suppressed from being excessively reinforced because the left and right arm plate portions 36a are easy to bend in the so-called out-of-plane direction.

[0058] In the front part of the swing arm 30, the part above the straight line T1 in side view is formed such that the left and right width becomes narrower as it is located more upward (toward the arm connection part side 37). As a result, the left and right width near the upper end part (near the arm connection part 37) of the swing arm 30 is narrowed and becomes compact, and the influence on the arrangement of peripheral parts is suppressed. Since no protruding shape is provided below the part along the straight line T1, the influence on the vehicle body's bank angle due to the increase in the left and right width of the part is suppressed.

[0059] At the rear part of the swing arm 30, the left and right arm main bodies 36 between the arm connecting part 37 and the rear end part (axle support part 39) in the front-rear direction are formed in a curved shape convex outward in the vehicle width direction in plan view. As a result, the left and right width between the left and right arm main bodies 36 is wider in front of the vicinity of the rear wheel axle 3a, and it becomes easier to secure a clearance with transmission parts such as the drive chain 73 and the belt. Since the left and right width in the vicinity of the rear wheel axle 3a (near the lower end part of the swing arm 30) is suppressed, the influence on the bank angle of the vehicle body is suppressed.

[0060] The left and right arm main bodies 36 and the arm plate part 36a are smoothly curved so as to be continuous in an S shape in plan view, and are shaped such that stress concentration hardly occurs. The arm plate part 36a of the left arm main body 36 may be provided so as to expand in 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 part 36a functions like a chain cover, and it is possible to suppress contact of external objects etc. with the drive chain 73 and the diffusion of chain noise.

[0061] As shown in FIGS. 3 to 5, a mount part 56 that is fastened and fixed to the bulkhead part 25 of the vehicle body frame 5 is provided at the front end part of the unit case 53 of the power unit 8. The mount part 56 is formed such that the left and right width becomes narrower toward the lower part with respect to the rectangular motor case 54 and gear case 55 when viewed in the front-rear direction.

[0062] The mount part 56 includes an upper wall part 56a, left and right side wall parts 56a1, a middle wall part 56b spaced below the upper wall part 56a, and left and right inclined walls 56c extending below the left and right side wall parts 56a1, and is formed in a hollow shape as a whole. A cushion front connecting part 56d for connecting the front end part of the rear cushion 32 protrudes above the upper wall part 56a.

[0063] On the left and right other sides (the right side in the embodiment) of the left and right inclined walls 56c, a connection terminal portion 59 for connecting a three-phase cable extending from the PCU 90 is provided. The connection terminal portion 59 is disposed in a recess 59a formed so as to notch the right inclined wall 56c of the mount portion 56 (inside the mount portion 56).

[0064] FIG. 13 is a perspective view of the lower part of the mount portion 56. Referring to FIG. 13, on one side (the left side in the embodiment) of the left and right inclined walls 56c, a stand fixing portion 56e for fastening and fixing stand brackets (not shown) that support the side stand may be provided. The stand fixing portion 56e is located in the vicinity of the lower fastening portion 58 (the fastening portion with the vehicle body frame 5) of the mount portion 56 and shares the strength and rigidity in the vicinity of the lower fastening portion 58. Thereby, compared with the case where the stand fixing portion 56e is provided on the vehicle body frame 5, the design freedom of the strength and rigidity of the lower part of the vehicle body frame 5 is improved.

[0065] FIG. 14 is a perspective view showing a modification example of the connection terminal portion 59 and the recess 59a. It may be provided on the outside of the mount portion 56 (for example, the right cover of the motor case 54), like the connection terminal portion 59' and the recess 59a' shown in FIG. 14. This is because when the axial thickness of the stator of the electric motor 50 increases, the positions of the connection terminal portion 59 and the bearing change outward in the axial direction. By concentrating such changing points on the left and right outer covers of the motor case 54, it is easy to cope with increasing the parts list of the power unit 8, and cost reduction can be achieved.

[0066] Referring to FIGS. 3 to 5, a pair of left and right upper fastening portions 57 fastened to the upper cross member 22 are provided at the left and right corners on both upper sides of the mounting portion 56. A single lower fastening portion 58 fastened to the lower cross member 23 is provided at the lower end portion of the mounting portion 56. Each of the fastening portions 57, 58 abuts against the fastening portion of the bulkhead portion 25 from the rear and is fastened by a bolt along the front-rear direction. Thereby, the power unit 8 including the electric motor 50 and the speed reducer 51, the pivot shaft 33 of the swing arm 30, and the front end portion of the rear cushion 32 can be integrally attached to the bulkhead portion 25.

[0067] FIG. 15 is a perspective view corresponding to a main part of FIG. 3 showing a first modification of the embodiment, FIG. 16 is a front view of the rear wheel suspension system 7 of the first modification, FIG. 17 is a right side view of the main part of the first modification, and FIG. 18 is a perspective view around the pivot adjuster 19a of the first modification. As shown in FIGS. 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 with respect to the main body side forming most 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 along the front-rear direction. A plurality of types for making the axial center position of the pivot shaft 33 variable may be set in the pivot block 19. At this time, a plurality of types of pivot adjusters 19a selected according to the axial center position of the pivot shaft 33 are set in the first pivot shaft support portion of the mounting portion 56.

[0068] For example, the front end portions of the step brackets 27a on the same side of the left and right may be fastened and fixed to the left and right pivot blocks 19. The step bracket 27a has a V shape convex rearward in side view and supports the step 27 so as to be foldable at the rear end portion. The upper and lower front end portions of the step bracket 27a abut against the rear end portion of the pivot block 19 from the left and right outsides and are respectively fastened and fixed by bolts along the left-right direction.

[0069] By making the pivot block 19 and the step bracket 27a detachably integrated with respect to the main body side of the pivot frame 18, in a vehicle in which the power unit 8 is mounted behind the pivot frame 18, it is easy to secure a space for attaching and detaching the power unit 8, and the attaching and detaching work of the power unit 8 becomes easy.

[0070] The lower end of the mount portion 56 is fastened to the lower cross member 23 at a single point, which has the following effects. That is, the position of the lower fastening portion 58 is lowered downward to increase the distance from the upper fastening portion 57, and the fastening region of the mount portion 56 (the region surrounded by a plurality of fastening portions) is widened to gain coupling rigidity. At the same time, the lower fastening portion 58 is made into a minimum number of single points, so that the left - right width of the lower part of the vehicle body close to the ground can be suppressed.

[0071] Since the mount portion 56 is formed so as to have a narrower left - right width downward, the left - right pivot frames 18 are also formed so as to have a narrower left - right width downward. As a result, the left - right width at the lower part of the pivot frame 18 is narrowed, and the vehicle body bank angle is surely secured. The mount portion 56 that supports the pivot shaft 33 improves the pivot rigidity due to the improvement of the rigidity by the connection with the vehicle body frame 5, and is a configuration suitable for high - output vehicles.

[0072] FIG. 19 is a perspective view showing the vehicle body frame 5' of the second modification of the embodiment, and FIG. 20 is a front view of the vehicle body frame 5' of the second modification. Referring to FIGS. 19 and 20, a configuration in which the vehicle body frame 5 continuously connects from the lower surface of the head pipe 16 to the front surface of the left - right pivot frames 18 is also conceivable. As shown in FIGS. 19 and 20, the vehicle body frame 5' includes 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, and a front wall portion 26c connecting the front ends of the left and right side wall portions 26a, and is provided with a box-shaped portion 26. The box-shaped portion 26 is used as a support structure for the branch of the battery unit 80 mounted between the left and right main frames 17. The box-shaped portion 26 enhances the rigidity of the vehicle body frame 5' for mounting heavy objects (drive system components) such as the battery unit 80, the PCU 90, and the power unit 8. For example, the outer peripheral portion of the lower surface of the bottom wall portion 26b of the box-shaped portion 26 is fixed by fastening the outer peripheral portion of the PCU 90. Thereby, the bottom wall portion 26b is reinforced by the PCU 90, and the rigidity of the vehicle body frame 5' can be further enhanced.

[0073] As described above, the saddle-type electric vehicle in the above embodiment includes a head portion (head pipe 16) that supports the steering wheel (front wheel 2) so as to be steerable, a pair of left and right main frames 17 that branch left and right from the head pipe 16 and extend rearward, a pair of left and right pivot frames 18 that extend downward from the rear end portions 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 has a vehicle body frame 5, a swing arm 30 whose front end portion is supported by the left and right pivot frames 18 and whose rear end portion supports a drive wheel (rear wheel 3), and includes an electric motor 50 for driving the vehicle, and is provided with a power unit 8 disposed rearward of the left and right pivot frames 18 in a side view of the vehicle. The power unit 8 includes at least a unit case 53 that houses the electric motor 50. The unit case 53 is provided with a mount portion 56 that is fastened in the vehicle front-rear direction to the upper and lower cross members 22, 23 between the left and right pivot frames 18. The pivot shaft 33 of the swing arm 30 is supported by the left and right pivot frames 18 and the mount portion 56.

[0074] According to this configuration, by providing the unit case 53 of the power unit 8 including the electric motor 50 for vehicle drive with the mount portion 56 fastened to the vehicle body frame 5 in the longitudinal direction of the vehicle, the following effects can be obtained. That is, the connection portion between the vehicle body frame 5 and the power unit 8 has a structure that easily receives the load (the load associated with acceleration and deceleration of the vehicle) due to the input and output of the electric motor 50. For this reason, the load on the fastening portion of the power unit 8 can be reduced (dispersed), and the adjustment of the strength and rigidity of the unit case 53 and thus the entire vehicle body can be facilitated. By supporting the pivot shaft 33 of the swing arm 30 with the left and right pivot frames 18 and the unit case 53, compared with the case where the pivot shaft 33 is supported only by the unit case 53, the adjustment of the strength and rigidity of the unit case 53 can be facilitated and the case rigidity can be optimized.

[0075] In the above saddle-riding type electric vehicle, the cross members 22 and 23 include an upper cross member 22 that connects between the upper portions of the left and right pivot frames 18, and a lower cross member 23 that connects between the lower portions of the left and right pivot frames 18. The upper portion of the mount portion 56 is provided with an upper fastening portion 57 fastened to the upper cross member 22, and the lower portion of the mount portion 56 is provided with a lower fastening portion 58 fastened to the lower cross member 23. The lower fastening portion 58 is fastened to the lower cross member 23 within a range closer to the vehicle width direction inner side than the upper fastening portion 57.

[0076] According to this configuration, since the lower fastening portion 58 of the unit case 53 is fastened to the lower cross member 23 within a range closer to the vehicle width direction inner side than the upper fastening portion 57, the left and right widths of the lower portion of the unit case 53 can be narrowed as much as possible, and it is possible to easily secure the bank angle of the vehicle body. In particular, by making the lower fastening portion 58 a minimum number of points at the center in the vehicle width direction, the left and right widths of the lower portion of the vehicle body close to the ground can be suppressed as much as possible.

[0077] In the above-described saddle-riding type electric vehicle, each of the left and right pivot frames 18 includes a pivot block 19 that is separate from the main body side of the pivot frame 18, and each of the left and right pivot blocks 19 supports the pivot shaft 33 of the swing arm 30 and may be fastened in the vehicle longitudinal direction with respect to the main body side of the left and right same-side pivot frames 18.

[0078] According to this configuration, the pivot shaft 33 is supported by the pivot block 19 that is separate from the main body side of the pivot frame 18, and the pivot block 19 is fastened in the vehicle longitudinal direction with respect to the main body side of the pivot frame 18, so that the range of the fastening portion in the vehicle longitudinal direction is widened together with the fastening portion of the unit case 53, and the coupling rigidity of the unit case assembly including the pivot block 19 and the pivot shaft 33 to the main body side of the vehicle body frame 5 can be increased. The assembly of the pivot block 19, the pivot shaft 33, and the power unit 8 can be collectively attached to the main body side of the vehicle body frame 5 by longitudinal fastening.

[0079] In the above-described saddle-riding type electric vehicle, steps 27 on the same left and right sides may be attached to each of the left and right pivot blocks 19. According to this configuration, by supporting the step 27 with the left and right pivot blocks 19, the step load can be received by the high-strength pivot block 19. As a result, the vehicle body frame 5 is not affected by ensuring the strength of the step mounting portion, and the adjustment of the strength rigidity of the main body side of the vehicle body frame 5 can be facilitated.

[0080] In the above-described saddle-riding type electric vehicle, a plurality of types of left and right pivot blocks 19 may be set with different axial center positions of the pivot shaft 33. According to this configuration, by setting a plurality of types of pivot blocks 19 with different center positions of the pivot shaft 33, the pivot position can be easily made variable by replacing the pivot block 19, and the versatility of vehicle parts can be increased.

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

[0082] According to this configuration, the rear cushion 32 is arranged to extend in the vehicle longitudinal direction straddling the drive shaft 50a of the electric motor 50. The front end portion of the rear cushion 32 is connected to the power unit 8, and the rear end portion of the rear cushion 32 is connected to the swing arm 30 via the link mechanism 31. By connecting the front end portion of the rear cushion 32 to a portion where the vehicle body frame 5 and the power unit 8 are fastened and the rigidity is increased, the front end portion of the rear cushion 32 can be supported with high rigidity without separately providing reinforcement at the connection portion of the front end portion of the rear cushion 32. Since the rear cushion 32 extends in the vehicle longitudinal direction above the power unit 8 and straddles the drive shaft 50a of the electric motor 50, the stroke amount of the rear cushion 32 can be efficiently secured while avoiding the power unit 8 disposed behind the pivot frame 18. Also, compared with the case where the rear cushion 32 is disposed between the power unit 8 and the rear wheel, an increase in the retreat of the rear wheel 3 and thus an increase in the wheelbase can be suppressed. The front end portion of the rear cushion 32 can also be connected to the vehicle body frame 5 instead of the power unit 8. That is, the front cushion connection portion 56d can also be provided on the upper cross member 22 or the like.

[0083] In the above saddle-riding type electric vehicle, the swing arm 30 includes a pair of left and right arm bodies 36 and an arm connection portion 37 that connects the left and right arm bodies 36. The left and right arm bodies 36 are bent so as to be convex upward in a side view of the vehicle. The arm connection portion 37 connects between the upper end portions of the left and right arm bodies 36, and a link mechanism 31 that connects the rear end portion of the rear cushion 32 and the swing arm 30 is disposed inside the arm connection portion 37.

[0084] According to this configuration, the left and right arm bodies 36 of the swing arm 30 are formed into an upwardly convex bent 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 disposed closer to the upper side of the swing arm 30, the left and right arm bodies 36 can be efficiently connected while avoiding the power unit 8 behind the pivot frame 18, and the rear end portion of the rear cushion 32 disposed above the power unit 8 can be easily connected. Since a link mechanism 31 for connecting the rear end portion of the rear cushion 32 is disposed inside the arm connecting portion 37, the degree of freedom in setting the suspension characteristics can be increased by the link mechanism 31, and the link type rear suspension can be configured compactly.

[0085] In the above saddle-riding type electric vehicle, the vehicle body frame 5' may include a box-shaped portion 26 including 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, and a front wall portion 26c connecting the front ends of the left and right side wall portions 26a.

[0086] According to this configuration, by providing the box-shaped portion 26 including the left and right side wall portions 26a, the bottom wall portion 26b, and the front wall portion 26c below the left and right main frames 17 of the vehicle body frame 5', it can be used as a branch structure of the battery unit 80 mounted between the left and right main frames 17. Thereby, the structure for supporting the battery unit 80 can be deleted or simplified to reduce the number of parts, and the rigidity of the vehicle body frame 5' on which the heavy battery unit 80 is mounted can be increased by the box-shaped portion 26.

[0087] In the above saddle-riding type electric vehicle, a control device (PCU90) for controlling the drive of the electric motor 50 may be provided, and the PCU90 may be fastened to the lower surface of the bottom wall portion 26b of the box-shaped portion 26. According to this configuration, by fastening the PCU 90 to the lower surface of the box-shaped portion 26 of the vehicle body frame 5', the structure for supporting the PCU 90 is deleted or simplified to reduce the number of parts, and the bottom wall portion 26b of the box-shaped portion 26 is reinforced by the fastening of the PCU 90, so that the rigidity of the vehicle body frame 5' can be further enhanced.

[0088] In the above saddle-riding type electric vehicle, when viewed from the vehicle longitudinal direction, the electric motor 50 may be arranged at a height overlapping with the PCU 90. According to this configuration, by arranging the PCU 90 and the electric motor 50 at a height overlapping with each other, not only the battery unit 80 mounted inside the box-shaped portion 26 and the PCU 90 are brought close to each other, but also the PCU 90 and the electric motor 50 are brought close to each other, thereby shortening the power lines between the battery unit 80, the PCU 90 and the electric motor 50 and concentrating the mass by the concentrated arrangement of heavy objects.

[0089] In the above saddle-riding type electric vehicle, the electric motor 50 and the drive wheels (rear wheels 3) are connected via an endless transmission member (drive chain 73), and a tensioner 75 for applying tension to the drive chain 73 may be supported by the unit case 53 of the power unit 8. According to this configuration, by supporting the tensioner 75 for the drive chain 73 on 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. For example, the configuration of this embodiment may be applied to saddle-riding type vehicles other than two-wheelers. The saddle-riding type vehicles include all vehicles in which the driver rides straddling the vehicle body, including not only motorcycles (including motor bicycles and scooter type vehicles), but also three-wheel (including vehicles with one front wheel and two rear wheels, as well as vehicles with two front wheels and one rear wheel) or four-wheel (such as four-wheel buggies) vehicles. And the configuration in the above embodiment is an example of the present invention, and various modifications are possible without departing from the gist of the present invention, such as replacing the components of the embodiment with well-known components.

Explanation of Signs

[0091] 1 Electric two-wheeler (straddle-type electric vehicle) 2 Front wheel (steering wheel) 3 Driving wheel 3 Rear wheel (driving wheel) 5, 5’ Vehicle body frame 8 Power unit 16 Head pipe (head part) 17 Main frame 18 Pivot frame 19 Pivot block 22 Upper cross member (cross member) 23 Lower cross member (cross member) 26 Box-shaped part 26a Side wall part 26b Bottom wall part 26c Front wall part 27 Step 30 Swing arm 31 Link mechanism 32 Rear cushion 33 Pivot shaft 36 Arm part 37 Arm connection part 50 Electric motor 50a Drive shaft 53 Unit case 56 Mounting part 56d Cushion front connection part 57 Upper fastening part 58 Lower fastening part 73 Drive chain (transmission member) 75 Tensioner 80 Battery 90 PCU (control device)

Claims

1. A vehicle frame (5) having a head portion (16) that supports a steering wheel (2) so as to be steerable, 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 portion of the main frame (17), and cross members (22, 23) connecting the left and right pivot frames (18); A swing arm (30) that supports a drive wheel (3); A power unit (8) including an electric motor (50) for vehicle drive and disposed rearward of 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) includes a mount portion (56) that is fastened in the vehicle longitudinal direction to the cross members (22, 23) between the left and right pivot frames (18); A saddle-type electric vehicle, wherein a pivot shaft (33) of the swing arm (30) is supported by the left and right pivot frames (18) and the mount portion (56).

2. The cross members (22, 23) include an upper cross member (22) that connects between upper portions of the left and right pivot frames (18), and a lower cross member (23) that connects between lower portions of the left and right pivot frames (18); An upper fastening portion (57) that is fastened to the upper cross member (22) is provided at an upper portion of the mount portion (56); A lower fastening portion (58) that is fastened to the lower cross member (23) is provided at a lower portion of the mount portion (56); The saddle-type electric vehicle according to Claim 1, wherein the lower fastening portion (58) is fastened to the lower cross member (23) within a range closer to the vehicle width direction inner side than the upper fastening portion (57).

3. Each of the left and right pivot frames (18) includes a pivot block (19) that is separate from 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 vehicle longitudinal direction to the main body side of the pivot frame (18) on the same left or right side.

4. The saddle-type electric vehicle according to Claim 3, wherein steps (27) on the same left or right side are attached to each of the left and right pivot blocks (19).

5. The saddle-ride type electric vehicle according to claim 3, wherein a plurality of types of the left and right pivot blocks (19) are set such that the axial center positions of the pivot shafts (33) are different.

6. comprising a rear cushion (32) connected to the swing arm (30), the rear cushion (32) is disposed above the power unit (8) in a posture with the stroke direction oriented in the longitudinal direction of the vehicle, the front end portion is connected to the vehicle body frame (5) or the power unit (8) in front of the drive shaft (50a) of the electric motor (50), and the rear end portion is connected to the swing arm (30) behind the drive shaft (50a) of the electric motor (50). The saddle-ride type electric vehicle according to claim 3.

7. the swing arm (30) includes a pair of left and right arm bodies (36) and an arm connecting portion (37) connecting the left and right arm bodies (36), the left and right arm bodies (36) are bent so as to be convex upward in a side view of the vehicle, the arm connecting portion (37) connects between the upper end portions of the left and right arm bodies (36), a link mechanism (31) for connecting the rear end portion of the rear cushion (32) and the swing arm (30) is disposed inside the arm connecting portion (37). The saddle-ride type electric vehicle according to claim 6.

8. the vehicle body frame (5) includes a box-shaped portion (26) including a pair of left and right side wall portions (26a) extending below 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), and a front wall portion (26c) connecting the front ends of the left and right side wall portions (26a). The saddle-ride type electric vehicle according to claim 3.

9. comprising a control device (90) for controlling the drive of the electric motor (50), the control device (90) is fastened to the lower surface of the bottom wall portion (26b) of the box-shaped portion (26). The saddle-ride type electric vehicle according to claim 8.

10. the electric motor (50) is disposed at a height overlapping the control device (90) when viewed from the longitudinal direction of the vehicle. The saddle-ride type electric vehicle according to claim 3.

11. the electric motor (50) and the drive wheel (3) are connected via an endless transmission member (73), The saddle-riding type electric vehicle according to claim 3, wherein a tensioner (75) for applying tension to the transmission member (73) is supported by the unit case (53) of the power unit (8).

Images