ELECTRIC VEHICLE OF THE STRAIGHT SEAT TYPE

Abstract

Electric vehicle of straddle seat type, including: a front wheel (FW) and a rear wheel (RW); a head tube (11) which carries a steering mechanism (18) for steering the front wheel (FW); a main frame (12) which is connected to the head tube (11) and extends in the longitudinal direction of the vehicle; a motor unit (30) with an electric motor (31) which outputs a driving force to rotate the rear wheel (RW); a battery (16) that supplies energy to the motor unit (30); and a swing arm (19) which is rotatably supported by a pivot axis (125) provided on the main frame (12), wherein the swing arm (19) rotatably supports the rear wheel (RW), wherein the motor unit (30) and the battery (16) are supported by the main frame (12) between the front wheel (FW) and the rear wheel (RW), the main frame (12) comprises a left and a right pair of sections (12L, 12R), the motor unit (30) is arranged in a top view of the vehicle between the pair of left and right sections (12L, 12R) and in a side view of the vehicle is arranged overlapping the main frame (12), characterized by the fact that an axial direction of a motor shaft (311) of the electric motor (31) and the direction of a vehicle width are aligned with each other and the motor shaft (311) is arranged above the axis of rotation (125) and the swing arm (19) and in the longitudinal direction of the vehicle to the rear.

Description

TECHNICAL AREA

[0001] The present invention relates to a straddle type electric vehicle BACKGROUND TECHNOLOGY

[0002] A known straddle-seat type electric vehicle using an electric motor as a power source includes a straddle-seat type electric vehicle installed with a battery that supplies power to an electric motor, and a control unit that controls the power supplied from the battery to the electric motor (e.g., WO 2012 / 063291 A1). US 2012 / 0103706 A1 describes an electric vehicle having a vehicle frame, an electric motor, and a swing arm pivotally supporting a rear wheel at its rear end. A drive shaft transmits the driving force of the electric motor to the wheel. The vehicle frame and the swing arm are connected to each other via a suspension. The electric motor is arranged in a longitudinal arrangement in which a rotating drive shaft is oriented in a front-rear direction of the vehicle, and the electric motor is arranged offset from the center of the vehicle in the width direction.The suspension is arranged under the electric motor and the drive shaft and on the inner sides of the electric motor and the drive shaft in the vehicle width direction and overlaps the positions of the electric motor and the drive shaft in the front-rear direction.

[0003] US 2012 / 0 111 651 A1 describes a saddle-type electric vehicle equipped with a drive battery and a conveniently located motor unit. The drive battery is mounted directly beneath a main frame portion of a vehicle frame, and the motor unit is rigidly attached to the vehicle frame. The motor unit comprises a motor body disposed beneath a pivoting connection of a rear swing arm, and at least a portion of the motor body is disposed behind the pivoting connection. SUMMARY OF THE INVENTION TECHNICAL PROBLEM

[0004] In a straddle-seat electric vehicle, where power is supplied from a battery to an electric motor, the range depends on the battery's capacity. Therefore, it is desirable to have space to accommodate a larger battery.

[0005] An object of the present invention is to provide a straddle-seat type electric vehicle in which more space can be ensured for accommodating a battery. SOLUTION TO THE PROBLEM

[0006] According to the present invention, there is provided an electric vehicle of the straddle type, comprising a front wheel and a rear wheel; a head tube carrying a steering mechanism for controlling the front wheel; a main frame connected to the head pipe and extending in the longitudinal direction of the vehicle; a motor unit with an electric motor that outputs a driving force to rotate the rear wheel; a battery that supplies the motor unit with energy; and a swing arm rotatably supported by a pivot axis provided on the main frame, the swing arm rotatably supporting the rear wheel, the motor unit and the battery are carried by the main frame between the front wheel and the rear wheel, the main frame comprises a pair of left and right sections, the engine unit is arranged between the pair of left and right sections in a plan view of the vehicle and is arranged overlapping the main frame in a side view of the vehicle, and an axial direction of a motor shaft of the electric motor and the direction of a vehicle width are aligned with each other and the motor shaft is arranged above the axis of rotation and the swing arm and rearward in the vehicle longitudinal direction. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0007] According to the present invention, a straddle-seat type electric vehicle is provided in which more space can be ensured for accommodating a battery. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a left side view of a straddle type electric vehicle according to an embodiment. Fig. 2 is a cross-sectional view along line II of Fig. 1, with some components omitted. Fig. 3 is a front view schematically illustrating a motor unit according to an embodiment. Fig. 4 is a rear view schematically showing a motor unit of Fig. 4 shows. Fig. 5 is a plan view of the motor unit of Fig. 4, which schematically shows an inner area. Fig. 6 is a left side view of a straddle type electric vehicle illustrating an arrangement portion of a motor unit. Fig. 7 is a left side view of a straddle type electric vehicle according to another embodiment. DESCRIPTION OF EMBODIMENTS

[0008] A straddle-type vehicle according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, arrows X, Y, and Z indicate mutually orthogonal directions, where the X direction indicates the front-rear direction of the straddle-type vehicle, the Y direction indicates the vehicle width direction (lateral direction) of the straddle-type vehicle, and the Z direction indicates the vertical direction. Hereinafter, the front and rear sides in the front-rear direction of the straddle-type vehicle may be simply referred to as "front" and "rear," and the inside and outside in the vehicle width direction (transverse direction) of the straddle-type vehicle may be simply referred to as "inside" and "outside." In addition, when describing a pair of left and right members, one of the two pairs may not be illustrated, or the description of the left and right pair may be omitted. Summary of the vehicle by straddle seat type

[0009] Fig. 1 is a left side view of a straddle-type electric vehicle 1 according to an embodiment of the present invention. The same drawing is a schematic view with a main part of the straddle-type electric vehicle 1 at the center. Hereinafter, the straddle-type electric vehicle 1 may be referred to as vehicle 1.

[0010] The vehicle 1 is provided with a vehicle body frame 10 including a head pipe 11 provided in a vehicle front portion, a main frame 12 connected to the head pipe 11 and extending in the front-rear direction, a down frame 13 extending downward from the main frame 12 in the front-rear direction, and a seat frame 14 extending rearward from the main frame 12. Furthermore, the main frames 12 are connected to each other at their rear end portions, and the down frames 13 are connected to each other at their rear end portions.

[0011] Next, both Fig. 2 as well as Fig. 1 referred to. Fig. 2 is a cross-sectional view along line II of Fig. 1, with some components omitted. The main frame 12 of the present embodiment includes a main frame 12L extending from the head pipe 11 on the left side of the vehicle 1, and a main frame 12R extending from the head pipe 11 on the right side of the vehicle 1. The frames are formed separately in the vehicle width direction (left and right). The main frames 12L, 12R include a pair of left and right backbone frames 123L, 123R and a pair of left and right pivot frames 124L, 124R. Hereinafter, the pair of left and right backbone frames 123L, 123R may be simply referred to as the backbone frame 123, and the pair of left and right pivot frames 124L, 124R may be simply referred to as the pivot frame 124. (Hereinafter, left and right pairs may be treated the same.)

[0012] The backbone frame 123 of the present embodiment includes an upper portion 123a extending rearwardly and downwardly from an upper portion of the head pipe 11 with respect to the vehicle, and a lower portion 123b extending rearwardly and downwardly from a lower portion of the head pipe 11 with respect to the vehicle. The upper portion 123a and the lower portion 123b are connected at a rear end portion 126 of the backbone frame 123 or connected at a center portion. With this configuration, weight reduction and increased rigidity of the main frame 12 can be achieved.

[0013] Note that, in the present embodiment, the main frame 12 is divided left and right from the head pipe 11 and extends rearward and downward with respect to the vehicle, thereby forming the main frames 12L, 12R along the entire area of ​​the main frame 12. However, other configurations may be adopted, including configurations in which a single frame part extends rearward from the head pipe 11 and branches left and right, and configurations in which the frame part does not branch. Furthermore, in the present embodiment, the main frame 123 includes the upper portion 123a extending rearward from an upper portion of the head pipe 11 and the lower portion 123b extending rearward from a lower portion, both of which are divided left and right.However, a configuration may be used in which a single section extends rearwardly to the left and right of the head pipe 11.

[0014] The left and right pivot frames 124L, 124R are formed to extend downward from the rear end portions 126 of the backbone frames 123L, 123R, respectively, and are connected at the lower ends to the rear ends of the down frames 13. Note that the backbone frame 123 and the pivot frame 124 may be integrally formed or may be separate members connected by metallurgical bonding such as welding, mechanical joining such as screw fastening, or the like.

[0015] A pair of left and right down frames 13L, 13R are provided, which extend downward from the main frame 12 in the front-rear direction of the vehicle. The down frames 13L, 13R extend downward from the lower portions of the main frames 12 to the lower ends, extend rearward from the lower end, and are connected to the lower ends of the pivot frames 124L, 124R.

[0016] In the present embodiment, the down frame 13 extends downward from a lower part of the main frame 12. However, a configuration in which the down frame 13 extends downward from the head pipe 11 may be adopted. Furthermore, the down frame 13 is formed divided into the down frame 13L and the down frame 13R along the entire area of ​​the down frame 13. However, a configuration in which a single frame extends downward from the head pipe 11 or the main frame 12 and then branches to the left and right may also be adopted.

[0017] The seat frame 14 is provided extending rearward from the main frames 12L, 12R and includes a pair of left and right seat rails 141 supporting a seat 4. Furthermore, a pair of left and right support frames 142 are provided extending downward from the pair of left and right seat rails 141 and connected to the main frames 12 and the pair of left and right seat rails 141. The pair of left and right support frames 142 are each provided with a mounting portion 143 to which a pair of left and right suspensions 21 are mounted. Note that, in the present embodiment, the rear suspension 21 is a pair of left and right ones. However, a link-type suspension may be provided between the engine unit 30 and the rear wheel RW to connect a single rear suspension and a rear swing arm 19 through a link.

[0018] The head pipe 11 supports a steering mechanism 18 for steering a front wheel FW. The steering mechanism 18 includes a steering shaft 181 rotatably supported on the head pipe 11, an upper bridge 182 fixed to an upper end portion of the steering mechanism 18, and a lower bridge 183 fixed to a lower end portion of the steering mechanism 18. The upper bridge 182 is provided with a handlebar 184 for the rider to steer the front wheel FW. A pair of left and right front forks 185 are supported by the upper bridge 182 and the lower bridge 183. The front forks 185 extend forward and downward with respect to the vehicle, and the front wheel is rotatably supported at its lower ends.

[0019] The rear swing arm 19 at a front end portion is rotatably supported by a pivot shaft 125 provided in the pivot frame 124. A rear wheel RW is rotatably supported at a rear end portion of the rear swing arm 19, and the rear wheel RW is rotationally driven by a chain 23 wound around a drive gear 323 of a motor unit 30 and a driven gear 22 of the rear wheel RW. The rear swing arm 19 includes a pair of left and right portions, and the left and right portions include, at their upper portions, support portions 191 that support the rear wheel suspensions 21, the rear wheel suspensions 21 damping the vibration.

[0020] Next, the Fig. 3 to 5 and the Fig. 1 and Fig. 2 is referred to. Fig. 3 is a front view schematically showing the motor unit 30. Fig. 4 is a plan view schematically illustrating an inner portion of the motor unit 30. Fig. 5 is a plan view schematically showing an inner portion of the motor unit 30.

[0021] The motor unit 30 includes an electric motor 31 that outputs a driving force to rotate the drive sprocket 323. Furthermore, the electric motor 31 is housed in a motor housing part 31a. In the present embodiment, the axial direction of a motor shaft 311 of the electric motor and the vehicle width direction are aligned, and the drive sprocket 323, which forms the output part of the motor unit 30, is arranged with its end face facing left.

[0022] The motor unit 30 also includes a deceleration section 32 for decelerating the driving force for rotating the electric motor 31. The deceleration section 32 includes a motor housing part 32a projecting outward from the motor housing part 31a in the vehicle width direction, a reduction gear 32b for decelerating the rotation of the motor shaft 311, and an output shaft 322 for outputting a rotational driving force after deceleration via the reduction gear 32b. In the present embodiment, the output shaft 322 is provided downward from the motor shaft 311 and forward from the motor shaft 311 in the vehicle longitudinal direction. Furthermore, the drive sprocket 323 is fixed to the output shaft 322 of the deceleration section 32.

[0023] An oil pan 33 is formed at a lower portion of the engine unit 30. The oil collected in the oil pan 33 is sucked by an oil pump 34 and discharged to lubricate and cool the internal portion of the engine unit 30. The oil supplied to the internal portions of the engine unit 30 is returned to the oil pan 33 by natural dripping.

[0024] The motor unit 30 contains, in its upper region and on the side where the delay section 32 is arranged, a vent chamber 37 for connecting the motor unit 30 to the environment and for gas-liquid separation. The motor unit 30 also contains an oil filter 36 that removes impurities from the oil circulating in the motor unit 30.

[0025] A battery 16 stores the power supplied to the motor unit 30. A control unit 40 performs power supply control (drive control) with the battery 16 as a power source for the motor unit 30, and particularly for the electric motor 31, in accordance with an acceleration operation and the like by the driver. The motor unit 30 and the control unit 40 are connected by an electrical connector 42, and power is supplied to the motor unit 30 from the control unit 40 via the electrical connector 42. In the present embodiment, cables are used as the electrical connector 42. However, another connector such as a bus bar capable of transmitting electrical signals may be used. In addition, the motor unit 30 and the control unit 40 generate heat during driving.However, a heat exchanger 24 and a circulating coolant cool the motor unit 30 and the control unit 40, thereby preventing the motor unit 30 and the control unit 40 from reaching a high temperature. Arrangement configuration of the motor unit and the control unit

[0026] It will be Fig. 1 and Fig. 2. In the present embodiment, a casing part 10a of the battery 16 is mainly defined by the main frames 12 and the down frames 13. In the present embodiment, the casing part 10a on the left side in the vehicle width direction is defined by the head pipe 11, the main frame 12L, and the down frame 13L connected in a loop-like shape, and the casing part 10a on the right side in the vehicle width direction is similarly defined by the head pipe 11, the main frame 12R, and the down frame 13R connected in a loop-like shape. With this loop-shaped frame, the protective effect of the sides of the battery 16 can be increased. The lower boundary of the casing part 10a is defined in the vertical direction by the down frames 13 and, on the upper side when the body frame 10 is opened, by a cover member 17.

[0027] Furthermore, the battery 16 is arranged between the backbone frames 123L, 123R as viewed from the top of the vehicle, and is supported by the backbone frames 123L, 123R and the down frames 13L, 13R via a fixing structure not shown. Furthermore, only the battery 16 is arranged to protrude higher than the backbone frames 123 and is covered by the cover member 17. Since the battery 16 protrudes higher than the backbone frames 123, a larger battery can be installed.

[0028] In the present embodiment, the following structure is used to provide more space for the battery 16 within the housing 10a. In other words, in the present embodiment, the motor unit 30 is arranged overlapping the main frame 12 in a side view of the vehicle, and the motor shaft 311 of the electric motor is arranged upward and rearward in the vehicle longitudinal direction from the rotation axis 125 provided on the rotating frame 124. Thus, the space between the main frames 12 in the housing 10a can be used as a space for arranging the motor unit 30, so that the remaining space can be used as a battery housing space. In the present embodiment, the motor unit 30 is arranged overlapping a rear part of the spine frame 123 and the rotating frame 124. When the motor unit 30 is arranged overlapping the rotating frame 124, the motor unit 30 can be arranged further rearward.This allows more space to be created for the battery 16 on the front side of the housing part 10a. Furthermore, the battery 16 can be arranged in the part on the front side of the housing part 10a up to a lower end region defined by the downward frame 13. In this way, the battery 16 can be arranged further toward the lower side, thereby lowering the center of gravity.

[0029] In the present embodiment, the motor shaft 311 is also arranged upward and rearward from the rotation axis 125. Thus, a part of the motor unit 30 is arranged outside the housing part 10a. This allows more housing space for the battery 16 to be created within the space of the housing part 10a. Since the motor shaft 311 is arranged behind the rotation axis 125, the battery 16, which is a heavy object, can also be arranged centrally with respect to the main frame 12. This allows the center of gravity of the vehicle to be set more centrally in the front-rear direction. Furthermore, since the motor shaft 311 is arranged above the rotation axis 125, the motor unit 30 can be protected from external interference such as flying stones and other flying debris.

[0030] Note that in the present embodiment, the motor unit 30 overlaps the backbone frame 123 and the pivot frame 124 in a side view of the vehicle. However, configurations in which the motor unit 30 overlaps only the backbone frame 123 or only the pivot frame 124 may be used.

[0031] It will be Fig. 6 referred to. Fig. 6 is a left side view of the straddle-seat type electric vehicle, illustrating a location area of ​​the motor unit. In the present embodiment, the motor shaft 311 of the motor unit 30 is located within an area A surrounded by the backbone frame 123, the seat rail 141, and the support frame 142 in a side view of the vehicle. Since the motor unit 30 can be located in the space below the seat 4 in this way, more space can be created for the battery 16 in the space within the housing part 10a.

[0032] Note that in the present embodiment, the motor unit 30 is arranged downward from the seat rail 141 in a side view of the vehicle and overlaps the support frame 142. However, other configurations may be used, including a configuration in which the motor unit 30 is arranged above the support frame 142 and overlaps the seat rail 141, or a configuration in which the motor unit 30 is arranged overlapping the seat rail 141 and the support frame 142.

[0033] In the present embodiment, the motor unit 30 is arranged such that the motor shaft 311 is located behind the rotation axis 125 and the output shaft 322 is located in front of the rotation axis 125. In other words, the rotation axis 125 is arranged between the motor shaft 311 and the output shaft 322 in the vehicle longitudinal direction. Also, in the present embodiment, in which a driver is standing on the vehicle 1 and the vehicle 1 is in a stopped position (where the forces acting on the vehicle body during acceleration and deceleration do not act on the vehicle body) and is upright, the axis of the rear wheel RW, the rotation axis 125 and the output shaft 322 are on a single straight line (on the straight line L of Fig. 1) Arranged in alignment. By arranging these components in a single straight line, the efficiency of power transmission can be improved.

[0034] Furthermore, the engine unit 30 is arranged, in a side view of the vehicle, such that the oil pan 33 protrudes rearward from the main frame 12. This allows airflow and the like to easily contact the oil pan 33, thereby improving the cooling effect of the oil. In the present embodiment, the engine unit 30 is arranged, in a side view of the vehicle, such that the oil pan 33 faces rearward from the swing frame 124 and protrudes downward from the support frame 142. This allows airflow and the like to easily contact the oil pan 33, thereby further improving the cooling effect of the oil.

[0035] In addition, the control unit 40 is arranged upward in a side view of the vehicle and close to the motor unit 30. Since the motor unit 30 and the control unit 40 are arranged close to each other, the electrical connector 42 connecting the motor unit 30 and the control unit 40 can be shortened. In the present embodiment, the electrical connector 42 connects a motor-side connecting portion 38 provided on a rear side (facing the right side of the vehicle in the assembled state) of the motor unit 30 to a controller-side connecting portion 48 provided on a surface of the control unit 40 facing the right side of the vehicle. However, the configuration of the connection position of the electrical connector 42 is not limited to this.For example, the electrical connector 42 can be shortened by connecting an upper surface of the motor unit 30 and a lower surface of the control unit 40. Also in the present embodiment, the control unit 40 is arranged overlapping the seat rail 141 in a side view of the vehicle. This allows the side of the control unit 40 to be protected.

[0036] An angle sensor 35 is provided inside the motor unit 30 for detecting a rotation angle of the electric motor 31. Furthermore, an upper portion of the motor unit 30 and a downward surface of the control unit 40 are connected via a wire harness 352 capable of transmitting electrical signals. An electrical signal based on a detection result of the angle sensor 35 is transmitted from the motor unit 30 to the control unit 40 via the wire harness 352. Since the wire harness 352 is provided on an upper portion of the surface of a vehicle front facing the motor unit 30, the wire harness 352 can be arranged outside a region where the rear swing arm 19 can rotate. Furthermore, since the wire harness 352 is connected to the upper portion of the motor unit 30, the wire harness 352 can be prevented from being immersed in water or the like.

[0037] The motor unit 30 is also arranged between the seat rails 141 in the top view of the vehicle. Since the motor unit 30 is arranged between the seat rails 141 in the top view of the vehicle, interference with the motor unit 30 by a passenger's legs can be prevented if the passenger's legs are jammed.

[0038] Next, the fastening structure of the engine unit 30 will be described. The engine unit 30 is fastened to a fastening portion 128 provided on the backbone frame, a fastening portion 129 provided on the pivot frame 124, and the fastening portion 143 provided on the support frame 142. Since the engine unit 30 is supported by the highly rigid vehicle body frame 10 at three points—the fastening portion 128, the fastening portion 129, and the fastening portion 143—the fastening rigidity of the engine unit 30 can be improved. Since the vehicle width-facing surface of the engine unit 30 is surrounded by the body frame 10, the protective effect of the vehicle width-facing surface of the engine unit 30 can also be increased.

[0039] In the present embodiment, the motor unit 30 includes through holes 301, 302, and 303 at positions corresponding to the attachment portions 128, 129, and 143. A fastener 501 extending in the vehicle width direction between the backbone frames 123L, 123R can be attached to the attachment portion 128. The fastener 501 is attached to the attachment portion 128 extending through the through hole 301 to attach the motor unit 30 to the backbone frame 123. Similarly, a fastener 502 is attached to the attachment portion 129 extending through the through hole 302 to attach the motor unit 30 to the rotating frame 124. Similarly, a fastening member 503 is attached to the fastening portion 143 extending through the through hole 303 to fix the motor unit 30 to the support frame 142.

[0040] Note that configurations other than the above-described configuration for fixing the motor unit 30 to the body frame 10 may be used, including, for example, a configuration for fixing the motor unit 30 to a pair of left and right parts by means of screw fastening or the like.

[0041] In the present embodiment, the motor unit 30 is also fixed to the fixing portions of the backbone frame 123, the rotating frame 124, and the support frame 142. However, the configuration for frames provided with fixing portions is not limited thereto. For example, a configuration may be adopted in which one fixing portion is provided at two portions on the backbone frame 123 and one portion on the support frame 142, or a configuration in which one fixing portion is provided at two portions on the rotating frame 124 and one portion on the support frame 142. In the above-described configurations, the fixing portion may also be provided on the seat rail 141 instead of the support frame 142. Also, another configuration for the fixing portions may be adopted, for example, in which the fixing portions are provided on brackets or the like extending from the frames.

[0042] Furthermore, the control unit 40 is clamped between the pivot frames 124 at a portion overlapping the seat rail 141 in a side view of the vehicle via a fastening structure (not shown). Since the control unit 40 can be arranged in the space under the seat, more space can be created for the battery 16 in the housing part 10a. Furthermore, since the control unit 40 is arranged between the seat rails 141, which have high rigidity, the fastening rigidity of the control unit 40 can be improved.

[0043] Next, the configuration of a refrigeration cycle of the present embodiment will be described with reference to Fig. 1 and Fig. 2. The heat exchanger 24 according to the present embodiment is a radiator, and the coolant is a cooling liquid (coolant).

[0044] The coolant cooled at the heat exchanger 24 circulates through the interior of a first tubular member 251 to the engine unit. Here, the first tubular member 251 extends rearward from the heat exchanger 24 along the backbone frame 123R, then extends upward, then extends along a lower surface of the control unit 40, and then connects to the engine unit 30. A water jacket is formed on a rear surface (surface on the opposite side of the surface provided with the retarding portion 32 and the like) of the engine unit 30, and the coolant flows through the water jacket to cool the engine unit 30. The coolant that has passed through the water jacket is circulated to the heat exchanger 24 through the inner portion of a second tubular member 252.Here, the second tubular member 252 extends from the engine unit 30 along the backbone frame 123R and is connected to the heat exchanger. In other words, the circulation path 25 includes the first tubular member 251, the engine unit 30, and the second tubular member 252. The coolant circulates through the circulation path 25 in sequence from the heat exchanger 24, the engine unit 30, and the heat exchanger 24.

[0045] In the present embodiment, the first tubular member 251 and the second tubular member 252 pass along the side of the battery 16 at a portion extending along the backbone frame 123. Thus, the coolant can cool the battery 16 by passing through the first tubular member 251 and the second tubular member 252. Since the first tubular member 251 extends along a lower surface of the control unit, the coolant can also cool the control unit 40 by passing through the first tubular member 251.

[0046] In the present embodiment, a flexible hose is used for the first tubular member 251 and the second tubular member 252. However, a tubular metal member or the like may also be used. Note that in the present embodiment, the heat exchanger 24 is a radiator, but an oil cooler may also be used. In the case where an oil cooler is used, the first tubular member 251 and the second tubular member 252 may be connected to the internal part of the engine unit 30 so that the coolant, i.e., oil, can also lubricate the internal part of the engine unit 30. Other embodiments

[0047] In the above-described configuration, a pair of left and right rear suspensions are provided. However, a configuration with a single rear suspension can be used. Fig.7 is a diagram illustrating the arrangement configuration of a rear suspension 71 according to another embodiment.

[0048] In the present embodiment, the independent rear suspension 71, which functions as a shock absorber and dampens the vibration of a swing arm 79, is provided rearward of an engine unit 70 in the vehicle longitudinal direction. An upper attachment portion 743 provided on the engine unit 70 is fixed to an upper part of the rear suspension 71. The upper attachment portion 743 supports the rear suspension 71 and is fixed to the support frame 142 by a fixing structure not shown. Also, lower attachment portions 791, 792 provided on the swing arm 79 are fixed to a lower part of the rear suspension 71. The rear suspension 71 and the swing arm 79 are partially overlapped in a side view of the vehicle, and at the overlapped portion, the rear suspension 71 is arranged between a pair of left and right portions of the rear swing arm 79.

[0049] With this configuration, a single rear suspension 71 can be installed, thereby reducing the number of configuration components. Furthermore, since the rear suspension 71 is disposed between the left and right pairs of portions of the rear swing arm 79, the rear suspension 71 can be arranged in a central area in the vehicle width direction. This prevents configuration components from protruding outward in the vehicle width direction. Furthermore, due to the upper mounting portion 743 provided on the engine unit 70, the rear suspension 71 is arranged close to the engine unit 70. In this way, the engine unit 70 and the rear suspension 71, which are heavy objects, can be arranged close to the center in the vehicle longitudinal direction. This improves the stability of the vehicle.

[0050] Note that in the present embodiment, swingarm 79 includes the lower mounting portion at two sections. However, a configuration in which the rear suspension 71 is supported at one section may also be used. Summary of embodiments

[0051] The embodiments described above disclose at least the following vehicle. 1. The straddle type electric vehicle according to the above-described embodiment is a straddle type electric vehicle (e.g. 1) comprising a front wheel (e.g. FW) and a rear wheel (e.g. RW); a head tube (e.g. 11) supporting a steering mechanism for controlling the front wheel; a main frame (e.g. 12) connected to the head pipe and extending in the longitudinal direction of the vehicle; a motor unit (e.g. 30) with an electric motor that outputs a driving force for rotating the rear wheel; a battery (e.g. 16) that supplies the motor unit with energy; and a swing arm (e.g. 19) rotatably supported by a pivot pin (e.g. 125) provided on the main frame, the swing arm rotatably supporting the rear wheel, the motor unit and the battery are carried by the main frame between the front wheel and the rear wheel, the main frame comprises a pair of left and right sections (e.g. 12L, 12R); the engine unit is arranged between the pair of left and right sections in a plan view of the vehicle and is arranged overlapping the main frame in a side view of the vehicle, and a motor shaft (e.g. 311) of the electric motor is arranged above the axis of rotation and to the rear in the longitudinal direction of the vehicle.

[0052] According to this embodiment, the motor unit is arranged between the main frames. This allows for more space for the battery in the remaining space. This creates a straddle-type electric vehicle that allows for more space for a battery. Since the motor shaft is located behind the rotation axis, the battery, which is a heavy object, can also be positioned centrally relative to the main frame. 2. Electric vehicle of straddle type according to the embodiment described above, comprising a pair of left and right seat frames (e.g. 14) extending from the pair of left and right sections of the main frame in the vehicle longitudinal direction, wherein in a side view of the vehicle, the engine unit is arranged so that it overlaps the pair of left and right seat frames, and the seat frames are each provided with a mounting section for the motor unit (e.g. 143) which carries the motor unit.

[0053] In this design, the motor unit is supported by the seat frame. This increases the rigidity of the motor unit. 3. Electric vehicle of straddle type according to the embodiment described above, comprising a control unit (e.g. 40) which carries out the drive control of the motor unit, wherein the seat frames each comprise a seat rail (e.g. 141) and a support frame (e.g. 142) extending rearward from the main frame below the seat rail, the motor unit is supported by the support frames, and The control unit is supported by the seat rails above the motor unit.

[0054] According to this embodiment, the control unit is positioned upwards and close to the motor unit. This allows for shortening the connecting elements. Since both the motor unit and the control unit are supported by the seat frames, positional misalignment between them can also be prevented. This prevents cable breakage or similar problems in the connecting element and increases its support rigidity. 4. Electric vehicle of straddle type according to the above-described design, wherein the motor unit contains a delay section (e.g. 32), the deceleration section comprises a reduction gear (e.g. 32b) for braking a rotary drive force of the electric motor and an output shaft (e.g. 322) for outputting the rotary drive force braked by the reduction gear, the motor shaft is arranged in a side view of the vehicle in an area (e.g. A) which is surrounded by the main frame, the seat rail and the support frame, and the output shaft is arranged in front of the axis of rotation in the vehicle longitudinal direction.

[0055] In this design, the motor shaft is located in the space under the seat. This allows more space for the battery to be created in the remaining space. 5. Electric vehicle of straddle type according to the above-described design, wherein an oil pan (e.g. 33) is provided at a lower part of the engine unit, and the oil pan is positioned protruding rearward from the main frame in the vehicle's longitudinal direction.

[0056] According to this design, the oil pan is positioned protruding rearward from the main frame. This allows the oil pan to easily come into contact with airflow or similar elements, thus improving the oil's cooling efficiency. 6. Electric vehicle of straddle type according to the above-described design, wherein a rear section of the main frame is provided with a pair of left and right rotating frames (e.g. 124L, 124R), and at least a part of the motor unit is arranged between the pair of left and right rotating frames.

[0057] This design allows the motor unit to be moved further back, creating more space for the battery at the front. 7. Electric vehicle of straddle type according to the above-described design, wherein the swing arm is provided with lower attachment sections (e.g. 791, 792) to which a lower section of a shock absorber is attached, and the motor unit is provided with an upper mounting section (e.g. 743) to which an upper section of the shock absorber is attached.

[0058] According to this embodiment, the rear suspension 71 is positioned close to the engine unit due to the upper mounting portion on the engine unit. This allows the engine unit and the rear suspension, which are heavy objects, to be positioned close to the center in the vehicle's longitudinal direction. This improves vehicle stability. LIST OF REFERENCE SYMBOLS

[0059] 1 straddle seat type vehicle, 11 head tube, 12 main frame, 12L, 12R left and right sections, 14 seat frame, 16 battery, 18 steering mechanism, 30 motor unit, 31 electric motor, 32 deceleration section, 32b reduction gear, 33 oil pan, 19 swing arm, 40 control unit, 124R, 124L left and right pivoting frames, 125 pivoting axis, 141 seat rail, 142 support frame, 143 fixing section, 311 motor shaft, 322 output shaft, 743 upper fixing section, 791, 792 lower fixing section, FW front wheel, RW rear wheel

Claims

[1] Electric vehicle of straddle type, comprising: one front wheel (FW) and one rear wheel (RW); a head tube (11) carrying a steering mechanism (18) for steering the front wheel (FW); a main frame (12) connected to the head pipe (11) and extending in the vehicle longitudinal direction; a motor unit (30) having an electric motor (31) which outputs a driving force for rotating the rear wheel (RW); a battery (16) that supplies the motor unit (30) with energy; and a swing arm (19) which is rotatably supported by a pivot axis (125) provided on the main frame (12), the swing arm (19) rotatably supporting the rear wheel (RW), wherein the motor unit (30) and the battery (16) are carried by the main frame (12) between the front wheel (FW) and the rear wheel (RW), the main frame (12) comprises a left and a right pair of sections (12L, 12R), the engine unit (30) is arranged between the pair of left and right sections (12L, 12R) in a plan view of the vehicle and is arranged overlapping the main frame (12) in a side view of the vehicle, characterized by , that an axial direction of a motor shaft (311) of the electric motor (31) and the direction of a vehicle width are aligned with each other and the motor shaft (311) is arranged above the axis of rotation (125) and the rocker arm (19) and rearward in the vehicle longitudinal direction. [2] A straddle-seat type electric vehicle according to claim 1, characterized by that it further includes: a pair of left and right seat frames (14) extending from the pair of left and right sections (12L, 12R) of the main frame (12) in the vehicle longitudinal direction, wherein in a side view of the vehicle, the engine unit (30) is arranged overlapping the pair of left and right seat frames (14), and the seat frames (14) are each provided with a fastening section (143) for the motor unit (30) which supports the motor unit (30). [3] Electric vehicle of straddle type according to claim 2, characterized by that it further includes: a control unit (40) which carries out the drive control of the motor unit (30), wherein the seat frames (14) each comprise a seat rail (141) and a support frame (142) extending rearwardly from the main frame (12) below the seat rail (141), the motor unit (30) is carried by the support frame (142), and the control unit (40) is carried by the seat rails (141) above the motor unit (30). [4] Electric vehicle of straddle type according to claim 3, characterized by , that the motor unit (30) contains a delay section (32), the deceleration section (32) includes a reduction gear (32b) for braking a rotational driving force of the electric motor (31) and an output shaft (322) for outputting the rotational driving force braked by the reduction gear (32b), the motor shaft (311) is arranged in a side view of the vehicle in an area surrounded by the main frame (12), the seat rail (141) and the support frame (142), and the output shaft (322) is arranged in front of the axis of rotation (125) in the vehicle longitudinal direction. [5] A straddle-seat type electric vehicle according to any one of claims 1 to 4, characterized by , that an oil pan (33) is provided at a lower part of the engine unit (30), and the oil pan (33) is arranged protruding rearward from the main frame (12) in the vehicle's longitudinal direction. [6] A straddle-seat type electric vehicle according to claim 1, characterized by , that a rear portion of the main frame (12) is provided with a pair of left and right rotating frames (124L, 124R), and at least a part of the motor unit (30) is arranged between the pair of left and right rotating frames (124L, 124R). [7] A straddle-seat type electric vehicle according to claim 1, characterized by , that the swing arm (19) is provided with a lower fastening section (791, 792) to which a lower section of a shock absorber is attached, and the motor unit (30) is provided with an upper fastening portion (743) to which an upper portion of the shock absorber is fastened.

Images