VEHICLE TILTING

Abstract

The invention relates to a multi-stage drive tilting vehicle intended to enable easier control of rocking posture and tilting posture transitions, and thus achieve a reduction in driver burden on roads with successive curves or successive uphill and downhill sections. The control unit in this multi-stage drive tilting vehicle performs the charging / discharging cycle of the capacitor.The capacitor charge / discharge cycle includes (a) acceleration control which is performed via the motor's generator using the discharge energy from the capacitor in the latter half of the curve to assist in the transition from inclined to upright position using force from the motor, in accordance with the input of the acceleration command to the accelerator handle, and (b) regenerative braking control which is performed via the motor's generator to charge the capacitor via regenerative braking for a period of time until the latter half of curve B to recover the capacitor's energy that was depleted due to assisting in the transition from inclined to upright position in the latter half of curve A, in accordance with the release of the acceleration command on the accelerator handle.

Description

Lean vehicle

[0001] The present invention relates to a lean vehicle with a multi-speed transmission.

[0002] For example, a motorcycle is a vehicle in which the front and rear drive wheels are aligned in the direction of travel, and the vehicle body leans left and right to maintain its posture while traveling. Specifically, when turning, a motorcycle leans its body toward the center of the turn to balance centrifugal force and gravity. This lean posture is determined by the turning radius and vehicle speed. For example, for the same turning radius, a faster vehicle speed requires a larger lean angle, and for the same vehicle speed, a smaller turning radius requires a larger lean angle. A distinctive dynamic characteristic of motorcycles is their posture change during turns. At the start of a turn, the vehicle body must transition from an upright to a lean posture, and at the end of the turn, the vehicle must transition from a lean to an upright posture. During this lean posture transition, the rider's control and balance are particularly important. Furthermore, a motorcycle's pitch posture also changes when accelerating and decelerating. During acceleration, inertial force causes the front of the vehicle body to rise and the rear of the vehicle body to drop. When decelerating, the front of the vehicle drops and the rear rises. This change in pitch attitude is related to the shift in the rider's center of gravity, and particularly affects the upper body of the rider who grips the handlebars.

[0003] Various hybrid systems have been proposed to suit the dynamic characteristics of such motorcycles. For example, Patent Document 1 discloses a hybrid motorcycle equipped with a 48V lithium-ion battery and a drive motor. In this system, the drive motor provides assistance when starting off or overtaking, and the battery is charged by regenerative power generated by the drive motor when decelerating. Also, in relation to Patent Document 1, Patent Document 2 discloses a motorcycle that can be switched by operating a switch between a normal driving mode and a boost mode in which the drive motor provides assistance in response to throttle operation.

[0004] Japanese Patent No. 4633843 Japanese Patent Laid-Open No. 2024-53958

[0005] Many motorcycles employ automatic or manual multi-speed transmissions, and vehicle speed is typically adjusted by shifting gears or operating the front and rear brakes. However, these operations are required frequently on roads with continuous curves or hills and downhill sections. In particular, appropriate timing and operation amount are required when transitioning to a lean position or controlling pitch position. In hybrid systems, 48V lithium-ion batteries generally have multiple cells electrically connected in series and parallel, which tends to increase their weight. In contrast, hybrid systems are desired to provide high motorcycle maneuverability, particularly high responsiveness during cornering. Furthermore, hybrid systems are desired to better accommodate the charge / discharge cycles on roads with continuous curves and hills and downhill sections. However, the charging speed of lithium-ion batteries in conventional hybrid systems is slow enough to fully absorb the power generated by regenerative braking, which is concentrated in a short period of time, such as on a portion of a curve or a portion of an uphill section. In other words, the energy generated on a portion of a curve or a portion of an uphill section cannot be fully stored in the lithium-ion battery. Therefore, if the intake of power generated by regenerative braking and the discharge of power by assisting the vehicle during other periods, such as when turning, are repeated, the charge level of the lithium-ion battery gradually decreases over the long term, which may limit the amount of assist. Thus, in conventional hybrid systems, it is desirable to be able to further prevent situations in which the vehicle's maneuverability is reduced due to the increased weight of the lithium-ion battery, or in which sufficient assist is not achieved due to a decrease in the charge level of the lithium-ion battery. This has led to a need to reduce the increase in the frequency of operations required to operate the vehicle and maintain its posture, which occurs when situations in which gear shifting and braking are required are mixed with situations in which gear shifting and braking are not required. In particular, on roads with continuous curves and continuous ups and downs, appropriate control of the amount and timing of operation is more important to compensate for reduced vehicle responsiveness. Therefore, it is desirable to reduce the rider's burden on roads with continuous curves and continuous ups and downs.

[0006] The present invention aims to solve the above problems and provide a lean vehicle with a multi-speed transmission that is lightweight and highly responsive, thereby facilitating lean posture transitions and assist control of pitch posture, particularly on roads with continuous curves or continuous ups and downs, thereby reducing the burden on the rider.

[0007] In order to achieve the above object, according to one aspect of the present invention, a vehicle has the following configuration: (1) A multi-speed transmission type lean vehicle including a handlebar with an accelerator grip, front wheels, rear drive wheels, a front wheel brake operator for adjusting the braking force of the front wheel brakes, a rear wheel brake operator for adjusting the braking force of the rear drive wheels, an engine for generating power to drive the rear drive wheels, a multi-speed transmission provided between the engine and the rear drive wheels, a rotating electric machine provided at an end of a crankshaft of the engine for receiving power from the rear drive wheels to generate regenerative electricity and assisting in driving the rear drive wheels, a control device for controlling the rotating electric machine, and a power source electrically connected to the rotating electric machine, wherein an increase in weight of the lean vehicle is suppressed and charging and discharging of the power source is performed with a large current in a short period of time. (A) the rotating electric machine is a motor generator, and is provided at an end of the crankshaft of the engine, and is configured as the only rotating electric machine that receives power from the rear drive wheels to generate regenerative electricity and assist in driving the rear drive wheels; and (B) the power source is configured to include a capacitor without a lithium ion battery pack having a plurality of cells electrically connected in series and parallel; and the control device: even when braking force adjustment by operation of the front wheel brake operator and the rear wheel brake operator and driving force adjustment by shifting the multi-stage transmission are not performed, the vehicle speed of the lean vehicle is adjusted by the regenerative power generation and driving assistance of the motor generator, and the lean attitude and pitch attitude of the lean vehicle are assisted and controlled; and (C) when traveling on a road with a series of curves, a combination of at least two consecutive curves A and B, and when traveling on a road with a series of ups and downs, a combination of at least two consecutive ups C and downs D, the capacitor discharge and charge cycle is: (a) acceleration control by the motor generator using the discharge power of the capacitor so as to assist the transition from a lean posture to an upright posture by engine power in response to an acceleration command input to the accelerator grip in the latter half of the curve A;(b) regenerative braking control in which, up to the latter half of the curve B, the capacitor is charged by regenerative braking using the motor generator in response to release of the acceleration command from the accelerator grip, so as to recover the power of the capacitor that has decreased due to assisting the transition from a lean posture to an upright posture in the latter half of the curve A; (c) acceleration control in which, in the up C, the motor generator uses the discharged power of the capacitor to assist the engine power in response to the acceleration command input to the accelerator grip; and (d) regenerative braking control in which, in the down D, the capacitor is charged by regenerative braking using the motor generator in response to release of the acceleration command from the accelerator grip, so as to recover the power of the capacitor that has decreased due to the acceleration control in the up C, while suppressing a change in pitch posture.

[0008] According to (1), a multi-speed transmission lean vehicle has a motor generator mounted on the end of the crankshaft, configured as the sole rotating electric machine for regenerative power generation and power assist. It does not include a lithium-ion battery pack as a power source, but instead includes a capacitor. This configuration reduces the weight of the lean vehicle compared to a lean vehicle in the background art that includes a drive motor for driving the drive wheels separate from the motor generator and a lithium-ion battery pack as a power source. Furthermore, the use of a capacitor enables large current charging and discharging in a short period of time. Furthermore, placing the motor generator on the engine output shaft facilitates coordinated control of engine power and power assist provided by the motor generator. Note that capacitors have a smaller energy capacity than lithium-ion batteries, limiting their ability to provide power assist for long periods of time. However, according to (1), the vehicle's weight is reduced, partially offsetting this disadvantage. Furthermore, because the vehicle is targeted for situations requiring power assist for short periods of time, such as on roads with continuous curves and ups and downs, the limited energy capacity of the capacitor is not a major issue. In this configuration, the control device executes a capacitor discharge / charge cycle in response to an acceleration command input from the accelerator grip and release of the acceleration command. The capacitor discharge / charge cycle includes regenerative braking control using regenerative power generation by the motor / generator and acceleration control for assisting driving. In particular, even when vehicle speed is not adjusted by operating the front and rear wheel brake operators or by shifting the multi-speed transmission, the control device can adjust the vehicle speed of the lean vehicle by controlling the engine and the motor / generator, effectively assisting changes in lean attitude and suppressing changes in pitch attitude compared to changes in pitch attitude caused by, for example, braking the front wheels.

[0009] This configuration provides the following benefits. On a road with a series of curves where curve B comes after curve A, by adding driving assistance from the motor generator to engine power when accelerating in the latter half of curve A, it is possible to promote the transition from a lean posture to an upright posture. In addition, by performing regenerative power generation between curves A and B, it is possible to recover power for the next curve. On a road with a series of ups and downs, driving assistance using electric power can be achieved on up C, and on down D, it is possible to recover power through regenerative power generation and suppress changes in pitch posture. On up C, driving assistance using the recovered electric power can be achieved.

[0010] These effects provide the following advantages. First, the lean vehicle's dynamic characteristics are improved through weight reduction, timely power assist and regenerative power generation through rapid charging and discharging of the capacitor, and smoother posture changes. As a result, the rider's driving burden is reduced because vehicle speed can be adjusted through control using the motor-generator and capacitor, reducing dependency on operating the front and rear brake operators and shifting gears in the multi-speed transmission. The frequency of operation during lean posture transitions is reduced, and a more comfortable ride is achieved through pitch posture assist control. Regarding specific driving scenarios, when navigating a series of curves, the vehicle is assisted in transitioning from a lean posture to an upright posture in the latter half of Curve A by power assist, and efficient regenerative power generation and power reuse are achieved between curves. When navigating a series of ups and downs, improved drivability is achieved through power assist on the upswing C, and pitch posture changes are suppressed and regenerative power generation is achieved on the downswing D. In particular, vehicle speed adjustment, which previously relied on gearshift and braking in conventional multi-speed transmission lean vehicles, can be achieved through regenerative power generation and drive assist by the motor generator. This reduces the frequency of gearshift and braking operations, which can easily cause pitch attitude changes due to, for example, short-term speed changes or front shock absorber compression. This allows the rider to reduce the frequency of gearshift and braking operations on roads with continuous curves or continuous ups and downs, further reducing the rider's driving burden. In addition, the lightweight vehicle body and the capacitor's highly responsive charge and discharge characteristics enable precise lean attitude transitions and pitch attitude assist control. This effectively assists lean attitude and pitch attitude changes, particularly on roads with continuous curves or continuous ups and downs, effectively reducing the rider's driving burden.

[0011] In (1), the control corresponding to the two curves and the ups and downs are described separately. However, actual roads include situations such as situations with only curves, situations with only ups and downs, and situations with a combination of curves and ups and downs. In the capacitor charge / discharge cycle of (1), the control for the two curves and the control for the ups and downs may be performed independently for each driving location. Furthermore, in the control in the capacitor charge / discharge cycle of (1), when both curves and ups and downs appear in a single driving location, both controls may be performed simultaneously. In this case, the driving burden on the rider can be reduced even in situations where the driving burden on the rider is even greater, such as when driving uphill or downhill.

[0012] According to one aspect of the present invention, the lean vehicle may employ the following configuration: (2) The lean vehicle of (1), wherein the power source supplies discharge power to the motor generator at a voltage higher than a voltage supplied to an accessory of the engine.

[0013] According to (2), the power supply supplies power to the motor-generator at a higher voltage than the voltage supplied to the engine's auxiliary equipment. This configuration provides the following advantages: Supplying power at a higher voltage reduces the current required to achieve the same output. Reducing the current allows for thinner electrical wiring and connectors, resulting in a lighter overall vehicle. The size and weight of the motor-generator can also be reduced, resulting in better vehicle maneuverability. The higher voltage provides higher output characteristics for the motor-generator, enabling efficient drive assist and regenerative power generation over a wider rotational speed range. This makes lean posture transitions and pitch posture assist control easier on roads with continuous curves and continuous ups and downs. By supplying power to the motor-generator at a higher voltage according to configuration (2), many advantages are achieved, including a lighter system weight, a wider control range, and higher power efficiency. These advantages result in better maneuverability for a lean vehicle and a reduced rider burden. In particular, lean posture transitions and pitch posture assist control can be performed more smoothly on roads with continuous curves and continuous ups and downs.

[0014] According to one aspect of the present invention, the lean vehicle can employ the following configuration: (3) The lean vehicle of a multi-speed transmission type according to either (1) or (2), wherein the control device executes d-axis control when assisting the driving of the motor generator with discharge power from the capacitor.

[0015] According to (3), the control device performs d-axis control when assisting the motor-generator with power from the capacitor. This configuration provides the following advantages. First, the capacitor has high output density and fast charge / discharge characteristics, allowing it to instantly supply a large current. This allows for rapid power supply to the motor-generator, suppressing fluctuations, and achieving high responsiveness. By combining d-axis control, the motor-generator current can be quickly adjusted, enabling fast torque response. Specifically, d-axis control allows for independent control of torque and magnetic flux, allowing the required torque to be generated instantly. This results in high vehicle responsiveness during acceleration and lean attitude transitions. Furthermore, the high control accuracy also improves the accuracy of vehicle behavior assistance control. This results in more accurate lean attitude transitions and pitch attitude assist control, reducing the rider's driving burden. Furthermore, the synergistic effect of the capacitor and d-axis control results in higher motor-generator efficiency, reducing the required motor-generator size and reducing the overall system weight. As described above, the configuration of (3) realizes a large current supply from the capacitor and highly accurate torque control of the d-axis control, thereby simultaneously achieving high vehicle responsiveness and high control accuracy. This makes it easier to transition to lean posture and to control assist for pitch posture, even on roads with continuous curves or continuous ups and downs, and further reduces the driving burden on the rider.

[0016] According to one aspect of the present invention, the lean vehicle can employ the following configuration: (4) A multi-speed variable-speed lean vehicle according to any one of (1) to (3), characterized in that, when the rotational speed range of the engine is equally divided into four regions, namely, a low rotational speed region, a low-medium rotational speed region, a medium-high rotational speed region, and a high rotational speed region, the motor generator is configured to perform regenerative power generation and driving assistance at least in the low rotational speed region.

[0017] According to (4), when the engine rotational speed range is divided into four equal regions, namely, a low rotational speed region, a low-to-medium rotational speed region, a medium-to-high rotational speed region, and a high rotational speed region, the motor-generator is configured to perform regenerative power generation and power assist at least in the low rotational speed region. First, on roads with continuous curves and continuous ups and downs, vehicle speeds are kept low and speed fluctuations are small. In this driving situation, riders tend to avoid driving in the high rotational speed region, where engine torque fluctuations in response to accelerator grip operation are relatively large, and instead operate the engine in the low rotational speed region as much as possible. In the low rotational speed region of the engine, output torque tends to be relatively small, and riders may feel that more engine output is desirable during acceleration or lean posture transitions. Here, by having the motor-generator perform power assist in the low rotational speed region, it is possible to supplement engine output and achieve smooth acceleration and lean posture transitions. Furthermore, because the power assist and regenerative power generation by the motor-generator are electrically controlled, they have better controllability compared to engine control. Motor generators are highly responsive and can adjust torque increases and decreases with high precision, thereby improving the accuracy of vehicle behavior assistance control. Furthermore, engine output is low at low rotational speeds, which relatively increases the torque contribution of the motor generator's drive assist, making it easier to control. This results in smoother vehicle response to accelerator operation and facilitates lean posture transitions and pitch posture assist control. During deceleration at low rotational speeds, the motor generator can generate electricity regeneratively and store power in a capacitor. This allows for efficient maintenance of the power needed for the next acceleration or drive assist on an uphill slope. Furthermore, limiting the motor generator's operating range to the low rotational speed range allows for reductions in its size and weight, resulting in a lighter vehicle. This improves vehicle maneuverability and contributes to improved power efficiency.

[0018] According to one aspect of the present invention, the lean vehicle can employ the following configuration: (5) A multi-speed transmission lean vehicle according to any one of (1) to (4), wherein the power source supplies to the motor generator (i) discharged power from the capacitor electrically connected in series with a battery that supplies power to accessories of the engine, or (ii) discharged power from the capacitor configured not to receive discharged power from a battery that supplies power to accessories of the engine.

[0019] According to the configuration (5), the power supply supplies one of the following discharge power to the motor-generator: (i) discharge power from a capacitor electrically connected in series with a battery that supplies power to engine accessories; or (ii) discharge power from a capacitor configured not to receive power from the battery that supplies power to engine accessories. This configuration first increases the number of options for the power supply configuration, thereby providing greater flexibility in vehicle design. Specifically, the option of connecting the capacitor in series with the battery or arranging it as a capacitor independent of the battery allows for optimal space efficiency and weight distribution in the vehicle. Furthermore, the power supply system design allows for flexible combinations of the engine accessory battery and the capacitor, thereby optimizing the voltage level and current capacity and maximizing the performance of the motor-generator. Furthermore, by configuring the capacitor not to receive power from the battery, the capacitor's charge / discharge cycle can be specialized for driving assistance and regenerative power generation of the motor-generator. This allows for efficient use of the capacitor's power and achieves high power efficiency. In contrast, a configuration in which the capacitor is connected in series with the battery allows for increased overall voltage, resulting in high power supply efficiency for the motor-generator. This is expected to improve the performance of the motor generator while reducing the weight of the entire system and improving space efficiency. As described above, the configuration of (5) provides high design freedom for the power supply and space, and has the effect of optimizing the performance and efficiency of the entire vehicle. This makes it possible to achieve good maneuverability for a lean vehicle and reduce the driving burden on the rider. In particular, the flexible design of the power supply system allows for optimal vehicle weight balance and space allocation, making it easier to transition between lean positions and assist control of pitch positions, even on roads with continuous curves and continuous ups and downs.

[0020] According to one aspect of the present invention, a lean vehicle can employ the following configuration: (6) A multi-speed transmission lean vehicle according to any one of (1) to (4), characterized in that the motor generator (iii) is configured to perform regenerative power generation and driving assistance in a rotational speed range of the engine that is equal to or less than half of the entire rotational speed range, or (iv) is provided with an L variable mechanism that varies the inductance L of the motor generator.

[0021] According to (6), the motor generator has one of the following configurations: (iii) It is configured to perform regenerative power generation and drive assist in a rotational speed range that is equal to or less than half of the engine's rotational speed range; or (iv) It is equipped with an L variable mechanism that varies the inductance L of the motor generator. This configuration provides the following effects: (iii) In the case of a configuration that operates in a range equal to or less than half of the engine's rotational speed range: First, by limiting the operating range of the motor generator to equal to or less than half of the engine's rotational speed range, the design of the motor generator can be optimized. Since operation in the high rotational speed range is not required, the size and weight of the motor generator can be reduced, resulting in a lighter vehicle. This provides high vehicle maneuverability and improves responsiveness during cornering and lean transitions. Furthermore, by limiting the operating range, the motor generator can be easily controlled, reducing the complexity of the control device. This results in high reliability of the entire system and contributes to cost reduction. Furthermore, because the motor generator does not operate in the high rotational speed range, wear and heat problems associated with high-speed rotation are reduced, resulting in greater durability of the motor generator and related components. (iv) In the case of a configuration with an L variable mechanism: By varying the inductance L, the characteristics of the motor generator can be optimized according to the driving situation. Specifically, it is possible to achieve high torque by increasing the inductance in the low rotational speed range and high efficiency by decreasing the inductance in the high rotational speed range. This allows the performance of the motor generator to be optimized over a wide rotational speed range, expanding its range of application. At the same time, by making the inductance variable, it is possible to suppress the increase in size and maintain a lightweight motor generator without increasing its size or weight. Furthermore, optimizing the inductance allows the motor generator to achieve high efficiency and reduce power loss. This effectively utilizes the power from the capacitor and improves power efficiency. Furthermore, by adjusting the inductance, the torque output from the motor generator can be controlled with greater precision, thereby improving the accuracy of vehicle behavior assistance control.This allows for smoother lean posture transitions and pitch posture assist control, reducing the rider's driving burden. Effect common to (iii) and (iv): As described above, the configuration of (6) reduces the weight of the motor-generator by limiting the operating range and varying the inductance, resulting in good vehicle maneuverability. Furthermore, variable inductance optimizes performance, enabling effective drive assistance and regenerative power generation over a wide rotational speed range, thereby expanding the range of operation. Furthermore, high motor-generator efficiency is achieved, enabling efficient use of power from the capacitor, resulting in high power efficiency. Additionally, limiting the operating range and adjusting the inductance facilitates control, improving system reliability. This allows for more precise assist control of vehicle behavior, resulting in smoother lean posture transitions and pitch posture assist control, reducing the rider's driving burden. This is particularly effective on roads with continuous curves and ups and downs.

[0022] The terminology used herein is for the purpose of defining particular embodiments only and is not intended to limit the invention. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed components. As used herein, the use of the terms "including," "comprising," or "having," and variations thereof, identifies the presence of stated features, steps, operations, elements, components, and / or equivalents thereof, but may include one or more of the steps, operations, elements, components, and / or groups thereof. As used herein, the terms "attached," "connected," "coupled," and / or equivalents thereof are used broadly and encompass both direct and indirect attachments, connections, and couplings. Furthermore, "connected" and "coupled" are not limited to physical or mechanical connections or couplings, but can include direct or indirect electrical connections or couplings. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms, such as those defined in commonly used dictionaries, should be interpreted to have a meaning consistent with the relevant technology and the context of this disclosure, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein. It is understood that numerous techniques and processes are disclosed in the description of the present invention. Each of these has distinct advantages, and each can be used with one or more, or in some cases all, of the other disclosed techniques. Therefore, for clarity, this description will refrain from unnecessarily repeating every possible combination of individual steps. Nevertheless, the specification and claims should be read with the understanding that all such combinations are within the scope of the present invention and claims. A new lean vehicle is described herein. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the present invention.However, it will be apparent to one skilled in the art that the present invention may be practiced without these specific details. The present disclosure is to be considered as an example of the present invention and is not intended to limit the invention to the specific embodiments illustrated by the following drawings or description.

[0023] A lean vehicle is a straddle-type vehicle in which the driver sits astride a saddle. A lean vehicle is a lean vehicle that turns in a lean position. A lean vehicle leans toward the center of turning when turning. A lean vehicle is, for example, a motorcycle or a three-wheeled motorcycle. Examples of such a vehicle include scooter-type, moped-type, off-road-type, and on-road-type motorcycles. Furthermore, a straddle-type vehicle is not limited to a motorcycle, and may be, for example, a three-wheeled or four-wheeled buggy known as an ATV (All Terrain Vehicle), a snowmobile, or the like. A multi-speed transmission-type lean vehicle is a lean vehicle that has a multi-speed transmission.

[0024] The front wheel brake operator is, for example, a brake lever. The rear wheel brake operator is, for example, a brake pedal. However, the rear wheel brake operator is not particularly limited and may be a lever. Inputting an acceleration command to the accelerator grip is, for example, applying an operating force to the accelerator grip to rotate the accelerator grip. Releasing the acceleration command to the accelerator grip is, for example, releasing the operating force applied to the accelerator grip so that the accelerator grip returns to its original rotation.

[0025] The engine may be an internal combustion engine, for example a single-cylinder engine or a multi-cylinder engine, for example a four-stroke engine or a two-stroke engine.

[0026] The rotating electric machine is, for example, a motor generator. The motor generator is a rotating electric machine that combines the functions of a motor and a generator. The motor generator is, for example, a permanent magnet type that generates a magnetic field using a permanent magnet. The motor generator is, for example, an outer rotor type. However, the motor generator is not particularly limited and may be, for example, an inner rotor type. Furthermore, the permanent magnet motor generator may be, for example, a radial gap type or an axial gap type. The functions of the rotating electric machine and the motor generator are not limited to a motor and a generator. The rotating electric machine and the motor generator may also have the function of a starter that starts an engine, for example.

[0027] The control device includes, for example, a processor that executes a program and a memory that stores the program and data. The control device is realized, for example, by the processor executing a program stored in the memory. However, the structure of the control device is not particularly limited, and may be, for example, a logic circuit that processes data without relying on a processor or a program. The control device may also have, for example, a function to control the engine. However, the control device is not particularly limited, and may be, for example, a separate device from the control device that controls the engine.

[0028] The execution / non-execution of the capacitor discharge / charge cycle may be switchable. For example, the execution / non-execution of the capacitor discharge / charge cycle can be selected manually by the rider of a lean vehicle. Such selection of execution / non-execution is performed, for example, by an ON / OFF operation of a capacitor discharge / charge cycle mode selector switch. Furthermore, the execution / non-execution may be automatically switched by a control device. For example, the automatic switching by the control device may be linked to, for example, current position data and map data, and automatic switching may be performed based on the terrain (road shape), such as winding roads.

[0029] D-axis control is the control of the current in the windings so that a d-axis current component that weakens the magnetic field generated by the permanent magnets of the motor generator flows through the windings. However, the control method is not particularly limited, and any method can be used as long as the control results in a current component that weakens the magnetic field flowing through the windings.

[0030] Two consecutive curves A and B are two curves that are encountered in sequence during driving, among a plurality of curves such as a switchback. Two consecutive curves A and B may be connected via a straight section between the curves A and B. Two consecutive up curves C and down curves D may also be connected via a straight section between the up curves C and down curves D.

[0031] According to the present invention, by configuring a lean vehicle to be lightweight and highly responsive, it is possible to provide a multi-speed transmission lean vehicle that facilitates lean posture transitions and pitch posture assist control, particularly on roads with continuous curves and continuous ups and downs, thereby reducing the burden on the rider.

[0032] FIG. 10 is a diagram illustrating a lean vehicle according to a first embodiment. FIG. 11 is a flowchart illustrating capacitor discharge / charge cycle control executed by a control device. FIG. 12 is a block diagram illustrating a configuration according to a second embodiment. FIG. 13 is a vector diagram illustrating the relationship between the voltages of a motor generator according to a third embodiment. FIG. 14 is a graph illustrating control according to a fourth embodiment. FIG. 15 is a block diagram illustrating a power supply configuration according to a fifth embodiment. FIG. 16 is a diagram illustrating operation and configuration according to a sixth embodiment.

[0033] Hereinafter, a lean vehicle according to an embodiment will be described with reference to the drawings. Note that the embodiment described below is merely an example. The present invention should not be construed as being limited in any way by the embodiment described below.

[0034] [First embodiment] Fig. 1 is a diagram illustrating a lean vehicle according to a first embodiment. Part (a) of Fig. 1 is a schematic side view of the lean vehicle. Part (b) of Fig. 1 is a block diagram illustrating a schematic configuration of a hybrid system of the lean vehicle. Part (c) of Fig. 1 is a conceptual diagram illustrating a combination of two consecutive curves. Part (d) of Fig. 1 is a diagram illustrating acceleration control and regenerative braking control. Part (e) of Fig. 1 is a conceptual diagram illustrating a combination of consecutive downhill and uphill curves.

[0035] The lean vehicle 10 shown in Figure 1 includes a handlebar 101, a front wheel 12b, a rear drive wheel 12a, a front wheel brake operator 17, a rear wheel brake operator 18, an engine 11, a multi-speed transmission 13, a rotating electric machine 14, a control device 15, and a power source 16.

[0036] An accelerator grip 19 is provided on the handlebar 101. The rear drive wheels 12a are wheels that provide driving force for the lean vehicle 10 to travel. The rear drive wheels 12a are also simply referred to as drive wheels 12a. The front brake operator 17 adjusts the braking force of the brakes on the front wheels 12b. The front brake operator 17 is provided, for example, on the handlebar 101 of the lean vehicle 10. The front brake operator 17 has, for example, a lever that is operated by the hand of the rider of the lean vehicle 10. The rear brake operator 18 adjusts the braking force of the brakes on the rear drive wheels 12a. The rear brake operator 18 has, for example, a pedal that is operated by the foot of the rider of the lean vehicle 10.

[0037] The engine 11 generates power to drive the drive wheels 12a. The engine 11 is an internal combustion engine. The engine 11 generates power by burning a mixture containing air and fuel. The engine 11 has a crankshaft 11a. The engine 11 outputs power as rotation of the crankshaft 11a. At least a portion of the power output from the engine 11 is transmitted to the drive wheels 12a as mechanical power.

[0038] The multi-speed transmission 13 is provided between the engine 11 and the drive wheels 12a. The multi-speed transmission 13 has a plurality of selectable gears and a neutral position. The multi-speed transmission 13 changes the speed of the rotation output from the engine 11 at a gear ratio corresponding to the selected gear and transmits the rotation to the drive wheels 12a. In this way, the multi-speed transmission 13 adjusts the driving force by changing gears.

[0039] The rotating electric machine 14 is provided at an end of the crankshaft 11a of the engine 11. The rotating electric machine 14 receives power from the drive wheels 12a to generate regenerative electricity. The rotating electric machine 14 also assists in driving the drive wheels 12a. The rotating electric machine 14 receives power supplied from an external source and applies rotational force in the rotation direction of the crankshaft 11a of the engine 11 operating in combustion mode. In this way, the rotating electric machine 14 assists in driving the drive wheels 12a by receiving the power supply. The rotating electric machine 14 can also generate electricity by receiving power from the engine 11 operating in combustion mode. The rotating electric machine 14 is, for example, a motor generator. Hereinafter, the rotating electric machine 14 will also be referred to as the motor generator 14.

[0040] The control device 15 controls the rotating electric machine 14. The control device 15 is configured as a computer having a central processing unit (CPU) that executes a program and a memory that stores the program and the execution results of the program. The central processing unit executes the program, thereby controlling the rotating electric machine 14 by the control device 15.

[0041] The power supply 16 is electrically connected to the rotating electric machine 14. More specifically, the power supply 16 is electrically connected to the rotating electric machine 14 via the control device 15. The power supply 16 has an electricity storage function. The power supply 16 exchanges power with the rotating electric machine 14. That is, the power supply 16 supplies power to the rotating electric machine 14 by discharging. The power supply 16 also charges by receiving power from the rotating electric machine 14.

[0042] The lean vehicle 10 is configured as follows (A) and (B) so that an increase in the weight of the lean vehicle 10 is suppressed and the power supply 16 is charged and discharged with a large current in a short time. (A) The rotating electric machine 14 is a motor generator and is provided at the end of the crankshaft 11a of the engine 11. Furthermore, the rotating electric machine 14 is configured as the only rotating electric machine that receives power from the drive wheels 12a to generate regenerative electricity and assist in driving the drive wheels 12a. (B) The power supply 16 is configured to include a capacitor 16c without a lithium-ion battery pack in which multiple cells are electrically connected in series and parallel. More specifically, the power supply 16 does not include a lithium-ion battery pack. The power supply 16 includes a capacitor 16c.

[0043] The control device 15 adjusts the vehicle speed of the lean vehicle 10 and performs control so that the lean posture and pitch attitude of the lean vehicle 10 are assisted and controlled even when the brake force is not adjusted by operating the front wheel brake operator 17 and the rear wheel brake operator 18, and the driving force is not adjusted by shifting the multi-speed transmission 13. Specifically, the control device 15 executes a capacitor discharge and charge cycle so that the vehicle speed of the lean vehicle 10 is adjusted and the lean posture and pitch attitude of the lean vehicle 10 are assisted and controlled by the regenerative power generation and drive assistance of the motor generator 14. More specifically, the control device 15 executes the capacitor discharge and charge cycle for a combination of at least two consecutive curves A and B when traveling on a road with a series of curves. The control device 15 also executes the capacitor discharge and charge cycle for a combination of at least two consecutive downhill and downhill curves D and C when traveling on a road with a series of ups and downs.

[0044] FIG. 2 is a flowchart illustrating the capacitor discharge / charge cycle control executed by the control device.

[0045] In the capacitor discharge / charge cycle control, the control device 15 executes (a) acceleration control on curves (S11), (b) regenerative braking control on curves (S12), (c) acceleration control on uphill / downhill slopes (S13), and (d) regenerative braking control on uphill / downhill slopes (S14), as shown in Fig. 2. Each control in the capacitor discharge / charge cycle control is executed depending on whether a condition, including an input to the accelerator grip 19, is satisfied.

[0046] The capacitor charge / discharge cycle control shown in Fig. 2 is executed, for example, by the rider turning on a selector switch (not shown). However, a configuration in which the capacitor charge / discharge cycle control is executed automatically by referencing current position data and map data of the lean vehicle 10 may also be adopted. By being able to switch between execution and non-execution of the capacitor charge / discharge cycle, it is possible to stop intervention of the control, for example, when traveling in a place other than a continuous curve or a continuous up-and-down road.

[0047] Part (c) of Fig. 1 shows a curved road R1 on which the lean-to-steer vehicle 10 travels. The curved road R1 includes multiple curves, including two consecutive curves, A and B. Part (e) of Fig. 1 shows a road with multiple ups and downs R2 on which the lean-to-steer vehicle 10 travels. The road with multiple ups and downs R2 includes multiple ups and downs, including a series of ups C and downs D. Part (d) of Fig. 1 shows the transition of power in the case of acceleration control and in the case of regenerative braking control. In part (d), the amount of power stored in the capacitor 16c is depicted as the amount of liquid stored in a container. The direction of power supply between the capacitor 16c and the motor-generator 14 is depicted by a thick arrow.

[0048] Each of the controls (a) to (d) executed by the control device 15 in the capacitor charge / discharge cycle control will be described with reference to parts (c) to (e) of FIG.

[0049] (a) Acceleration control on a curve is control by the motor generator 14 using the discharge power of the capacitor 16c to assist the transition from a lean posture to an upright posture by the power of the engine 11 in response to an acceleration command input to the accelerator grip 19 in the latter half As of the curve A. In the first half As of the curve A, the lean vehicle 10 is operated to assume a lean posture. In the latter half As of the curve A, the lean vehicle 10 is operated to transition from a lean posture to an upright posture. The transition from a lean posture to an upright posture requires acceleration of the lean vehicle 10. The transition from a lean posture to an upright posture is assisted by the acceleration control by the motor generator 14 using the discharge power of the capacitor 16c. The acceleration control reduces the power stored in the capacitor 16c.

[0050] (b) Regenerative braking control on a curve is control in which, during the period Bf up to the latter half of curve B, in response to the release of the acceleration command from the accelerator grip 19, the capacitor 16c is charged by regenerative braking using the motor generator 14 to recover the power lost in the capacitor 16c due to assisting the transition from a lean posture to an upright posture in the latter half As of curve A. After passing through curve A, during the period Bf up to the latter half of curve B, the lean vehicle 10 is operated to transition from an upright posture to a lean posture. The transition from an upright posture to a lean posture requires deceleration of the lean vehicle 10. The regenerative braking using the motor generator 14 in response to the release of the acceleration command from the accelerator grip 19 decelerates the lean vehicle 10 and charges the capacitor 16c. The regenerative braking control increases the power stored in the capacitor 16c. The capacitor 16c is charged to recover the power lost due to assisting the transition from a lean posture to an upright posture in the latter half As of curve A.

[0051] (c) Acceleration control during up-and-down is control by the motor generator 14 using the discharged power of the capacitor 16c so as to supplement the power of the engine 11 in response to an acceleration command input to the accelerator grip 19 in up-C. In up-C, the lean vehicle 10 is accelerated to suppress the amount of deceleration caused by up-C. The acceleration control by the motor generator 14 using the discharged power of the capacitor 16c assists in suppressing deceleration caused by the power of the engine 11. Note that in acceleration control during up-C, the purpose of the control is achieved as long as deceleration caused by up-C is suppressed, even if the lean vehicle 10 itself does not accelerate. The acceleration control reduces the power stored in the capacitor 16c.

[0052] (d) Regenerative braking control during up-and-down is control in which, during down-D, the capacitor 16c is charged by regenerative braking using the motor generator 14 so as to suppress changes in pitch attitude in response to the release of the acceleration command from the accelerator grip 19. During down-D, the lean vehicle 10 is operated to decelerate. The regenerative braking using the motor generator 14 in response to the release of the acceleration command from the accelerator grip 19 assists the deceleration control using the power of the engine 11. Note that with deceleration control during down-D, the purpose of the control is achieved even if the lean vehicle 10 itself does not decelerate, as long as acceleration during down-D is suppressed. As the deceleration control occurs, the capacitor 16c is charged. The regenerative braking control increases the power stored in the capacitor 16c. The capacitor 16c is charged to recover the power lost by assisting the acceleration during up-C.

[0053] According to this embodiment, a lean-fuel vehicle 10 equipped with a multi-speed transmission 13 includes a motor-generator 14 mounted on the end of the crankshaft 11a, which serves as the sole rotating electric machine 14 for regenerative power generation and drive assist. The power source 16 does not include a lithium-ion battery pack, but instead includes a capacitor 16c. This configuration allows for a lighter weight of the lean-fuel vehicle 10 compared to a lean-fuel vehicle such as that described in Patent Document 1, which includes a drive motor for driving the drive wheels separate from the motor-generator and a lithium-ion battery pack as a power source. Furthermore, the use of the capacitor 16c enables large current charging and discharging in a short period of time. Furthermore, placing the motor-generator 14 on the output shaft of the engine 11, i.e., on the crankshaft 11a, facilitates coordinated control of the power of the engine 11 and the drive assist provided by the motor-generator 14.

[0054] Part (f) of FIG. 1 is a graph illustrating an example of the charge amount when traveling on a road with successive curves. P represents the charge amount of the capacitor, and P' represents the charge amount for a lithium-ion battery as a reference example. The charge amount increases due to charging under regenerative braking control and decreases due to discharging under assist control. The charging rate of a lithium-ion battery is slower than that of a capacitor, so the slope of the charge increase is small. Therefore, if charging under regenerative braking control in the latter half of a curve and discharging under assist control until the latter half of the next curve are repeated, the charge amount P' of the lithium-ion battery will gradually decrease over the long term, which may limit the implementation of assist. In contrast, the capacitor 16c in this embodiment is larger than that of a lithium-ion battery, so the slope of the charge increase is steeper. Therefore, even if charging under regenerative braking control in the latter half of a curve and discharging under assist control until the latter half of the next curve are repeated, the long-term decrease in the charge amount is suppressed.

[0055] Note that the capacitor 16c has a smaller energy capacity than a lithium-ion battery, limiting its ability to provide long-term driving assistance. However, according to this embodiment, the required energy amount is reduced by reducing the vehicle's weight, partially offsetting this disadvantage. Furthermore, since the system is targeted at situations requiring short-term driving assistance, such as roads R1 and R2 with continuous curves and ups and downs, the limited energy capacity of the capacitor 16c is not a major issue. In this configuration, the control device 15 executes a capacitor discharge / charge cycle in response to an acceleration command input and release from the accelerator grip 19. The capacitor discharge / charge cycle includes regenerative braking control using regenerative power generation by the motor-generator 14 and acceleration control for driving assistance. In particular, even when vehicle speed adjustment is not performed by operating the front wheel brake operator 17 and the rear wheel brake operator 18 or by shifting the multi-speed transmission 13, the vehicle speed of the lean vehicle 10 can be adjusted and the lean posture and pitch posture can be assisted by controlling the engine 11 and the motor-generator 14.

[0056] With this configuration, on the curved road R1, when accelerating in the latter half As of the curve A, the transition from a lean posture to an upright posture can be promoted by adding driving assistance from the motor generator 14 to the power of the engine 11. Also, by performing regenerative power generation between the curves A and B, it is possible to recover some or all of the electric power for the next curve B. On the up-and-down road R2, it is possible to recover electric power through regenerative power generation on the down curve D and suppress changes in the pitch posture. On the up curve C, driving assistance can be achieved using the recovered electric power.

[0057] These actions firstly achieve, in terms of maneuverability of the lean vehicle 10, higher responsiveness due to the lighter weight, timely drive assist and regenerative power generation due to the rapid charging and discharging of the capacitor 16c, and smoother attitude changes. As a result, in terms of the driving burden on the rider, vehicle speed can be adjusted by control using the motor-generator 14 and the capacitor 16c, so dependency on operation of the front wheel brake operator 17 and the rear wheel brake operator 18 and on shifting the gears of the multi-speed transmission 13 can be reduced. The operational burden during transitions to a lean attitude is reduced, and a better ride comfort can be obtained through assist control of the pitch attitude.

[0058] As specific effects for each driving scenario, on consecutive curves A and B, high maneuverability is achieved through power assist in the transition from a lean posture to an upright posture in the latter half of curve A, as well as efficient regenerative power generation and power reuse between curves. On consecutive up-and-down roads R2, high drivability is achieved through suppression of pitch posture changes and regenerative power generation on the downhill road D, and power assist on the uphill road C. In particular, vehicle speed adjustment, which relies on gear shifting and braking in conventional multi-speed transmission lean vehicles, can be achieved through regenerative power generation and power assist by the motor-generator 14. As a result, on roads R1 and R2 with consecutive curves and up-and-down roads, the rider can reduce the frequency of gear shifting and braking, further reducing the rider's driving burden. In addition, the lightweight vehicle body and the highly responsive charge / discharge characteristics of the capacitor 16c enable precise lean posture transition and pitch posture assist control, which was not possible with conventional lean vehicles. This effectively assists the rider in changing the lean and pitch attitudes, particularly on roads R1 and R2 that have successive curves and successive ups and downs, and effectively reduces the rider's driving burden.

[0059] Second Embodiment FIG. 3 is a block diagram showing a configuration according to a second embodiment.

[0060] The hybrid system HV of the lean vehicle 10 shown in FIG. 3 includes an auxiliary device 21 and an auxiliary power supply 22. The auxiliary device 21 is a device for causing the engine 11 to perform combustion. The auxiliary device 21 is electrically driven. The auxiliary device 21 includes, for example, a fuel supply device and an ignition device. The auxiliary power supply 22 supplies power to the auxiliary device 21. The auxiliary power supply 22 is, for example, a battery. The power supply 16 supplies power to the motor generator 14 at a voltage higher than the voltage supplied to the auxiliary device 21. These are the main differences from the first embodiment. Hereinafter, differences from the first embodiment will be mainly described, and elements common to the first embodiment will be denoted by the same reference numerals and will not be described again.

[0061] According to this embodiment, power is supplied to the motor-generator 14 at a higher voltage than the voltage supplied to the accessories 21, thereby reducing the current required to achieve the same output. Reducing the current allows for thinner electrical wiring and connectors, thereby reducing the overall weight of the lean vehicle 10. The size and weight of the motor-generator 14 can also be reduced, resulting in improved vehicle maneuverability. The high voltage provides higher output characteristics for the motor-generator 14, enabling efficient drive assistance and regenerative power generation over a wider rotational speed range. This further facilitates lean posture transitions and pitch posture assist control on roads R1 and R2 with continuous curves and ups and downs. The configuration of this embodiment, in which power is supplied to the motor-generator 14 at a high voltage, provides many benefits, including a lighter hybrid system (HV), a wider control range, and higher power efficiency. These benefits enable the lean vehicle 10 to achieve improved maneuverability and reduce the rider's driving burden. In particular, on roads R1 and R2 that have successive curves and successive ups and downs, the transition of the lean attitude and the assist control of the pitch attitude can be performed more smoothly.

[0062] Third Embodiment FIG. 4 is a vector diagram showing the relationship between voltages of a motor generator according to a third embodiment.

[0063] In this embodiment, the control device 15 executes d-axis control when using the discharge power from the capacitor 16c to assist in driving the motor-generator 14. The d-axis control is a control implemented in the vector control of the motor-generator 14. The d-axis control controls the current in the windings so that a current component that weakens the magnetic flux due to the magnetic poles of the motor-generator 14 flows through the windings. In the d-axis control, the d-axis current component is controlled among the d-axis and q-axis current components defined with respect to the rotor position in the rotating coordinate system of the motor-generator 14. The d-axis in the rotating coordinate system is the direction along the magnetic poles of the rotor. The above points are the main differences from the first embodiment. Hereinafter, differences from the first embodiment will be mainly described, and elements common to the first embodiment will be denoted by the same reference numerals and will not be described again.

[0064] In the vector diagram of FIG. 4 , Vhigh represents the magnitude of the voltage of the power supply 16. E represents the induced electromotive force. Id represents the d-axis current component, which is the field-weakening current. Iq represents the q-axis current component. The induced electromotive force E is suppressed by the voltage drops Iq·R and Iq·Lω caused by the q-axis current Iq, and the voltage drops Id·R and Id·Lω caused by the d-axis current Id. R is the resistance component of the winding, L is the inductance, and ω is the angular velocity in electrical angle. The q-axis current Iq responds to the occasional torque demands of the motor-generator 14. By using d-axis control, the induced electromotive force E can be significantly suppressed by Id·Lω.

[0065] In the configuration of this embodiment, first, the capacitor 16c has high output density and fast charge / discharge characteristics, allowing it to instantaneously supply a large current. This allows for rapid power supply to the motor-generator 14, suppressing fluctuations and achieving high responsiveness. By combining d-axis control, the current of the motor-generator 14 can be quickly adjusted, enabling fast torque response. Specifically, d-axis control allows for independent control of torque and magnetic flux, allowing the required torque to be generated instantly. This results in higher vehicle responsiveness during acceleration and lean attitude transitions. Furthermore, higher control accuracy allows for more precise assist control of the lean attitude transitions and pitch attitude, reducing the rider's driving burden. Furthermore, the synergistic effect of the capacitor 16c and d-axis control results in higher efficiency of the motor-generator 14, allowing for a reduction in the required motor-generator 14 size, thereby reducing the overall weight of the hybrid system HV. As described above, the configuration of this embodiment realizes a large current supply from the capacitor 16c and highly accurate torque control of the d-axis control, thereby simultaneously achieving high responsiveness and high control accuracy for the lean vehicle 10. This makes it easier to transition to a lean posture and to control the assist of the pitch posture, even on roads R1 and R2 that have successive curves and successive ups and downs, and makes it possible to further reduce the driving burden on the rider.

[0066] Fourth Embodiment FIG. 5 is a graph illustrating control according to a fourth embodiment.

[0067] In this embodiment, when the rotational speed range of the engine 11 up to its maximum rotational speed Nmax is divided into four equal regions: a low rotational speed region F1, a low-to-medium rotational speed region F2, a medium-to-high rotational speed region F3, and a high rotational speed region F4, the motor-generator 14 is configured to perform regenerative power generation and drive assist at least in the low rotational speed region F1. The control device 15 in this embodiment performs regenerative power generation and drive assist for the motor-generator 14 at least in the low rotational speed region F1. The above points are the main differences from the first embodiment. Hereinafter, differences from the first embodiment will be mainly described, and elements common to the first embodiment will be designated by the same reference numerals and will not be described again.

[0068] On roads R1 and R2 with successive curves and ups and downs, vehicle speeds are kept low and speed fluctuations are small. In these driving conditions, the rider tends to avoid excessive engine torque fluctuations in response to the operation of the accelerator grip 19 and operate the engine 11 in the low rotational speed region F1 as much as possible. In the low rotational speed region F1 of the engine 11, output torque is likely to decrease, and a decrease in engine power may be felt during acceleration or transition to a lean posture. According to this embodiment, the motor-generator 14 performs drive assist in the low rotational speed region F1, thereby supplementing the output of the engine 11 and achieving smooth acceleration and transition to a lean posture. Furthermore, because the drive assist and regenerative power generation by the motor-generator 14 are electrically controlled, they have better controllability than control of the engine 11. The motor-generator 14 has high responsiveness and can adjust torque increases and decreases with high precision, allowing for more precise assist control of the behavior of the lean vehicle 10. Furthermore, in the low rotational speed region F1, engine output is small, and the torque contribution rate of the drive assist from the motor-generator 14 increases relatively, making control easier. This allows the lean vehicle 10 to respond smoothly to accelerator operation, facilitating lean posture transitions and assist control of pitch posture. During deceleration in the low rotational speed region F1, the motor generator 14 can perform regenerative power generation and store power in the capacitor 16c. This makes it possible to efficiently obtain the power needed for the next acceleration or driving assistance on an uphill slope. Furthermore, by limiting the operating range of the motor generator 14 to the low rotational speed region F1, the size and weight of the motor generator 14 can be reduced, thereby reducing the weight of the lean vehicle 10. This provides the lean vehicle 10 with higher maneuverability and also contributes to improved power efficiency.

[0069] Fifth Embodiment FIG. 6 is a block diagram showing a power supply configuration according to a fifth embodiment.

[0070] The power supply 16 in this embodiment supplies the motor generator 14 with either the following (i) or (ii) discharge power: (i) Discharge power from a capacitor 16c electrically connected in series with a battery 22 that supplies power to the accessories 21 of the engine 11, as shown in part (a) of FIG. 6; or (ii) Discharge power from a capacitor 16c that is configured not to receive discharge power from the battery 22 that supplies power to the accessories 21 of the engine 11, as shown in part (b) of FIG. 6. These are the main differences from the first embodiment. Hereinafter, differences from the first embodiment will be mainly described, and elements common to the first embodiment will be denoted by the same reference numerals and will not be described again.

[0071] According to this embodiment, first, the increased number of options for the configuration of the power supply 16 allows for greater vehicle design flexibility. Specifically, the option of connecting the capacitor 16c in series with the battery 22 or arranging the capacitor 16c as a separate capacitor from the battery 22 allows for optimal space efficiency and weight distribution in the lean vehicle 10. Furthermore, the power supply system can be designed with flexibility in combining the battery 22 for the engine 11's accessories with the capacitor 16c, optimizing the voltage level and current capacity and maximizing the performance of the motor-generator 14. Furthermore, by configuring the capacitor 16c so that it does not receive power from the battery 22, the charge / discharge cycle of the capacitor 16c can be specialized for driving assistance and regenerative power generation for the motor-generator 14. This allows for efficient use of the power of the capacitor 16c, resulting in higher power efficiency. In contrast, a configuration in which the capacitor 16c is connected in series with the battery 22 allows for increased overall voltage of the power supply 16, resulting in higher power supply efficiency to the motor-generator 14. This is expected to improve the performance of the motor-generator 14 while also reducing the overall system weight and improving space efficiency. As described above, the configuration of this embodiment provides greater design freedom for the power source 16 and space, resulting in the effect of optimizing the performance and efficiency of the entire lean vehicle 10. This provides greater maneuverability for the lean vehicle 10 and reduces the driving burden on the rider. In particular, the flexible design of the power supply system allows for optimal weight balance and space allocation for the lean vehicle 10, making it easier to transition between lean positions and assist control of pitch positions even on roads R1 and R2 that have successive curves and successive ups and downs.

[0072] In the configuration described in (i) above in which the power supply 16 supplies the motor generator 14 with discharged power from the capacitor 16c connected in series to the battery 22, when the motor generator 14 generates power, the power is charged into the capacitor 16c connected in series to the battery 22. However, the connection during charging is not limited to series. For example, as shown in the left diagram of part (c) of FIG. 6, discharged power from the capacitor 16c connected in series to the battery 22 is supplied to the motor generator 14. However, when the motor generator 14 generates power, the current generated by the motor generator 14 may be charged into the capacitor 16c connected in parallel to the battery 22, as shown in the right diagram of part (c) of FIG. 6. For example, the right diagram of part (c) of FIG. 6 shows a circuit during charging in which the capacitor 16c is connected in series with the DC-DC converter 23, and the series-connected capacitor 16c and the DC-DC converter 23 are connected in parallel to the battery 22. The parallel connection and series connection described above are switched by changing the state of the battery 22, the capacitor 16c, and transistor switches (not shown) connected to their periphery. During charging, a portion of the current generated by the motor-generator 14 is supplied to the battery 22, and another portion is supplied to the capacitor 16c via the DC-DC converter 23. Due to the voltage step-down effect of the DC-DC converter 23, a charge is stored in the capacitor 16c at a voltage lower than that of the battery 22. During discharging, as shown in the left diagram of part (c) of FIG. 6 , discharge power from the capacitor 16c connected in series to the battery 22 is supplied to the motor-generator 14. At this time, a high voltage corresponding to the sum of the voltages of the battery 22 and the capacitor 16c is supplied from the power source 16 to the motor-generator 14. In other words, a voltage higher than the charging voltage resulting from power generation by the motor-generator 14 can be applied to the motor-generator 14 during discharging.

[0073] Furthermore, the DC-DC converter 23 may be omitted from the circuit during charging shown in the right diagram of part (c) of Figure 6. In this case, during power generation, the same voltage is applied to the capacitor 16c and the battery 22. Then, during discharge, as shown in the right diagram of part (c) of Figure 6, a voltage twice the voltage of the battery 22 can be applied to the motor generator 14 from the capacitor 16c connected in series to the battery 22.

[0074] [Sixth embodiment] Fig. 7 is a diagram illustrating the operation and configuration according to a sixth embodiment. Part (a) of Fig. 7 is a graph illustrating the control range. Part (b) of Fig. 7 is a partial cross-sectional view of a motor generator having an L variable mechanism.

[0075] The motor generator 14 in this embodiment has either the following configuration (iii) or (iv): (iii) As shown in part (a) of Figure 7, regenerative power generation and driving assistance are performed in a low rotation speed region F11 that is less than half of the rotation speed range up to the maximum rotation speed Nmax of the engine 11. (iv) As shown in part (b) of Figure 7, an L variable mechanism that varies the inductance L of the motor generator 14.

[0076] The above (iii) is achieved, for example, by the control device 15 performing regenerative power generation and driving assistance for the motor-generator 14 in the low rotational speed region F11 shown in part (a) of Figure 7. Regarding the above (iv), part (b) of Figure 7 shows an enlarged partial cross section of the motor-generator 14 having an L variable mechanism. The motor-generator 14 includes a rotor 141 having magnetic poles and a stator 142. Part (b) of Figure 7 shows an outer rotor type motor-generator 14. The stator 142 includes a core 143a, teeth 143b, and windings 144. The windings 144 are wound around the teeth 143b. The core 143a and the teeth 143b form a magnetic path. The core 143a is rotatable in the rotational direction within an angular range corresponding to the width of the teeth 143b. For example, when the core 143a rotates relative to the teeth 143b and the area of ​​the portion facing the teeth 143b decreases, the magnetic resistance of the magnetic path passing through the winding 144 increases. Therefore, the inductance L of the winding 144 decreases. Conversely, when the area of ​​the portion facing the teeth 143b increases, the inductance L increases. The inductance L of the motor-generator 14 shown in part (b) of FIG. 7 is variable. The L variable mechanism can also be used in an inner rotor type or an axial gap type. Alternatively, the L variable mechanism can be a mechanism in which an additional electrical terminal is provided midway through the winding wound around one tooth, and the effective number of turns is changed by switching the terminal through which current flows, thereby changing the inductance L. These are the main differences from the first embodiment. Hereinafter, differences from the first embodiment will be mainly described, and elements common to the first embodiment will be denoted by the same reference numerals and will not be described again.

[0077] The configuration of this embodiment provides the following benefits. (iii) In the case of a configuration that operates within a range equal to or less than half the rotational speed range of the engine: First, by limiting the operating range of the motor-generator 14 to a range equal to or less than half the rotational speed range of the engine 11, the design of the motor-generator 14 can be optimized. Because operation in the high rotational speed range F12 is unnecessary, the size and weight of the motor-generator 14 can be reduced, resulting in a lighter lean vehicle 10. This improves the maneuverability of the lean vehicle 10 and improves responsiveness during cornering and lean posture transitions. Furthermore, by limiting the operating range, control of the motor-generator 14 is simplified, reducing the complexity of the control device 15. This improves the reliability of the entire hybrid system HV and contributes to cost reduction. Furthermore, because the motor-generator 14 does not operate within the high rotational speed range F12, wear and heat problems associated with high-speed rotation are reduced, resulting in increased durability of the motor-generator 14 and related components. (iv) In the case of a configuration that includes an L variable mechanism: By making the inductance L variable, the characteristics of the motor-generator 14 can be optimized according to the driving situation. Specifically, in the low rotational speed region F11, the inductance L can be increased to achieve high torque, and in the high rotational speed region F12, the inductance L can be decreased to achieve higher efficiency. This allows the performance of the motor-generator 14 to be optimized over a wide rotational speed range, expanding its range of application. At the same time, by making the inductance L variable, the motor-generator 14 can be kept lightweight without increasing its size or weight. Furthermore, optimizing the inductance L allows the motor-generator 14 to achieve higher efficiency and reduce power loss. This effectively utilizes the power from the capacitor 16c, improving power efficiency. Furthermore, adjusting the inductance L allows the torque output from the motor-generator 14 to be controlled with high precision, enabling precise assist control of vehicle behavior. This allows for smoother lean posture transitions and pitch posture assist control, reducing the rider's driving burden.(iii) (iv) Common Effects: As described above, the configuration of this embodiment reduces the weight of the motor-generator 14 by limiting the operating range and varying the inductance L, resulting in higher vehicle maneuverability. Furthermore, varying the inductance L optimizes performance, enabling effective drive assistance and regenerative power generation over a wide rotational speed range, thereby expanding the operating range. Furthermore, higher efficiency of the motor-generator 14 is achieved, enabling efficient use of power from the capacitor 16c, resulting in higher power efficiency. Additionally, limiting the operating range and adjusting the inductance L facilitates control, improving the reliability of the hybrid system HV. This enables precise assistance control of the lean vehicle 10, enabling smoother transitions in the lean attitude and smoother assist control of the pitch attitude, reducing the rider's driving burden. This is particularly effective on roads R1 and R2 with continuous curves and ups and downs.

[0078] The above-described embodiments can be combined in any manner. For example, the second embodiment, in which discharge power is supplied to the motor generator at a voltage higher than the voltage supplied to the engine accessories, can be combined with the d-axis control of the third embodiment. Furthermore, the fourth embodiment can be combined with the motor generator that performs regenerative power generation and driving assistance in the low rotational speed range. Furthermore, the fifth embodiment can be combined with the control of supplying discharge power from a capacitor connected to the battery or from a capacitor that does not receive discharge power from the battery to the motor generator. Furthermore, the sixth embodiment can be combined with the regenerative power generation and driving assistance performed in the rotational speed range of half or less, or with the L variable mechanism. Furthermore, the third embodiment can be combined with the d-axis control of the third embodiment with the motor generator that performs regenerative power generation and driving assistance in the low rotational speed range of the fourth embodiment. Furthermore, the fifth embodiment can be combined with the control of supplying discharge power from a capacitor connected to the battery or from a capacitor that does not receive discharge power from the battery to the motor generator. In addition, the regenerative power generation and driving assistance performed in a rotational speed range of half or less of the total, or the L variable mechanism, as in the sixth embodiment, can be combined. For example, the motor-generator that performs regenerative power generation and driving assistance in a low rotational speed range as in the fourth embodiment can be combined with the control of supplying discharged power from a capacitor connected to the battery or discharged power from a capacitor that does not receive discharged power from the battery to the motor-generator as in the fifth embodiment. In addition, the regenerative power generation and driving assistance performed in a rotational speed range of half or less of the total, or the L variable mechanism, as in the sixth embodiment, can be combined. For example, the control of supplying discharged power from a capacitor connected to the battery or discharged power from a capacitor that does not receive discharged power from the battery to the motor-generator as in the fifth embodiment can be combined with the regenerative power generation and driving assistance performed in a rotational speed range of half or less of the total, or the L variable mechanism, as in the sixth embodiment.

[0079] REFERENCE SIGNS LIST 10 lean vehicle 11 engine 11a crankshaft 12a rear drive wheels (drive wheels) 12b front wheels 13 multi-speed transmission 14 motor generator (rotating electric machine) 15 control device 16 power source 16c capacitor 17 front wheel brake operator 18 rear wheel brake operator 19 accelerator grip 21 accessory 22 battery 101 handlebar

Claims

1. A multi-speed transmission type lean vehicle comprising: a handlebar equipped with an accelerator grip; front wheels; rear drive wheels; a front wheel brake operator for adjusting the braking force of the front wheel brakes; a rear wheel brake operator for adjusting the braking force of the rear drive wheels; an engine for generating power for driving the rear drive wheels; a multi-speed transmission provided between the engine and the rear drive wheels; a rotating electric machine provided at an end of a crankshaft of the engine for receiving power from the rear drive wheels, generating regenerative electricity, and assisting in the drive of the rear drive wheels; a control device for controlling the rotating electric machine; and a power source electrically connected to the rotating electric machine, wherein an increase in weight of the lean vehicle is suppressed and charging and discharging of the power source is performed with a large current in a short period of time. (A) the rotating electric machine is a motor generator provided at an end of the crankshaft of the engine, and configured as the only rotating electric machine that receives power from the rear drive wheels, generates regenerative electricity, and assists in driving the rear drive wheels; and (B) the power source is configured to include a capacitor without a lithium ion battery pack having a plurality of cells electrically connected in series and parallel, and the control device is configured to: adjust the vehicle speed of the lean vehicle by the regenerative power generation and drive assistance of the motor generator, and assist control the lean attitude and pitch attitude of the lean vehicle, even when adjustment of braking force by operation of the front wheel brake operator and the rear wheel brake operator, and adjustment of drive force by shifting the multi-stage transmission are not performed; and (C) execute a capacitor discharge / charge cycle in a combination of at least two consecutive curves A and B when traveling on a road with a series of curves, and in a combination of at least two consecutive ups C and downs D when traveling on a road with a series of ups and downs, and the capacitor discharge / charge cycle is configured as follows: (a) acceleration control by the motor generator using the discharge power of the capacitor so as to assist a transition from a lean posture to an upright posture by engine power in response to an acceleration command input to the accelerator grip in a latter half of the curve A;(b) regenerative braking control in which the capacitor is charged by regenerative braking performed by the motor generator in response to release of an acceleration command from the accelerator grip until the latter half of the curve B, so as to recover the power of the capacitor that has been reduced by assisting the transition from a lean posture to an upright posture in the latter half of the curve A; (c) acceleration control in which the motor generator uses the discharged power of the capacitor to assist the power of the engine in response to an acceleration command input to the accelerator grip in the up C; and (d) regenerative braking control in which the motor generator charges the capacitor by regenerative braking performed by the motor generator in response to release of an acceleration command from the accelerator grip in the down D, while suppressing a change in pitch posture, so as to recover the power of the capacitor that has been reduced by the acceleration control in the up C.

2. A lean vehicle of a multi-speed transmission type according to claim 1, wherein the power source supplies discharge power to the motor generator at a voltage higher than a voltage supplied to an auxiliary device of the engine.

3. A lean vehicle with a multi-speed transmission according to claim 1 or 2, wherein the control device executes d-axis control when the motor generator is assisted in driving by the discharged power from the capacitor.

4. A multi-speed transmission type lean vehicle as described in any one of claims 1 to 3, characterized in that when the engine rotational speed range is equally divided into four regions, namely, a low rotational speed region, a low-medium rotational speed region, a medium-high rotational speed region, and a high rotational speed region, the motor generator is configured to perform regenerative power generation and driving assistance at least in the low rotational speed region.

5. A lean vehicle of a multi-speed transmission type as described in any one of claims 1 to 4, wherein the power source supplies to the motor generator (i) discharge power from the capacitor electrically connected in series with a battery that supplies power to the engine's auxiliary equipment, or (ii) discharge power from the capacitor configured not to receive discharge power from a battery that supplies power to the engine's auxiliary equipment.

6. A multi-speed transmission lean vehicle as described in any one of claims 1 to 5, characterized in that the motor generator is (iii) configured to perform regenerative power generation and driving assistance in a rotational speed range of the engine that is less than half of the entire rotational speed range, or (iv) is equipped with an L variable mechanism that varies the inductance L of the motor generator.

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