JP6828778B2 - Front and rear wheel drive vehicle drive control system and its drive control method - Google Patents

Description

The present invention relates to a drive control technique for a front and rear wheel drive vehicle that provides a sufficient driving force while improving the turning performance of the vehicle and enables smooth operation.

Patent Document 1 describes a front-rear wheel-drive two-wheel drive vehicle in which a rear wheel drive source and a front wheel motor drive source are individually driven and controlled, and the motor is mounted on the steering system. In this front-rear wheel drive motorcycle, the influence on the steering of the front wheels is reduced by mounting the motor on the steering system.

Japanese Unexamined Patent Publication No. 5-16872

However, in the front / rear wheel drive two-wheeled vehicle of Patent Document 1, when the vehicle body tilts to the left or right (hereinafter, bank) when the vehicle turns, the tire contact point shifts to the inside in the turning direction from the center of the steering axis. , The increase in the driving force of the motor due to the operator opening (accelerating) the accelerator may affect the alignment torque of the steering system.

In a normal rear-wheel drive vehicle, the tire contact patch moves inward from the center of the steering axis in the turning direction when the vehicle turns, so a moment generated around the center of the steering axis due to the running resistance applied to the tire contact patch acts to steer the steering. It acts in the direction of cutting inward (turning direction). In this case, the direction of the force received by the front wheels does not change even if the operator opens the accelerator from the accelerator off.

On the other hand, in a front-rear wheel drive motorcycle as in Patent Document 1, when the operator opens the accelerator to give the driving force of the front wheels and the driving force overcomes the running resistance, the moment around the center of the steering axis is opposite. It works in the direction and acts in the direction of turning the steering wheel outward (opposite the turning direction). As a result, the direction and magnitude of the steering force required for maneuvering will change, which may give the operator a sense of discomfort.

The present invention has been made in consideration of the above-mentioned circumstances, and is a drive control technique for a front and rear wheel drive vehicle that enables smooth and stable operation by reducing the influence of the driving force applied to the steering wheels on steering. The purpose is to provide.

Drive control system of the front and rear wheel drive vehicle according to the present invention, in order to solve the problems described above, a drive wheel to the front wheels and the rear wheels, Ri one of the driving wheel steering wheel der, only the front and rear of the drive wheels It is a drive control system provided for a front-rear wheel drive vehicle that travels by moving the tire contact point to the inside of the steering axis in the turning direction when the vehicle body tilts to the left or right when the vehicle turns. When the vehicle is in the bank state, the drive control system reduces the target drive torque of the steering wheel with respect to the accelerator operation amount during the acceleration operation of the operator, as compared with the case where the vehicle is in the upright running state . It is characterized in that control is performed.

Further, the drive control method for a front / rear wheel drive vehicle according to the present invention has drive wheels on the front wheels and the rear wheels in order to solve the above-mentioned problems, and one drive wheel is a steering wheel to drive the front and rear wheels. A drive control method for a front-rear wheel-driven vehicle that runs only on wheels, with the tire contact point moved inward in the turning direction from the center of the steering axis when the vehicle body tilts to the left or right when the vehicle turns. In the front-rear wheel drive vehicle, when the vehicle is in the bank state, the target drive of the steering wheel with respect to the accelerator operation amount during the acceleration operation of the operator is compared with the case where the vehicle is in the upright running state. It is a drive control method characterized by performing control to reduce torque .

In the present invention, when the front and rear wheel drive vehicle is in the bank state, the target drive torque of the steering wheel due to the acceleration operation of the operator is reduced as compared with the case where the vehicle is in the upright running state. The effect of changes in the applied driving force on the steering behavior is reduced, and the stability of the vehicle body is further improved.

The left side view which shows the embodiment of this invention and shows the overall appearance shape of the front-rear wheel drive vehicle. A front view of the front and rear wheel drive vehicle shown in FIG. 1 as viewed from the front of the vehicle. The right side view which shows the vehicle front part of the front-rear wheel drive vehicle shown in FIG. Left side view showing the body frame structure of the front half of the front and rear wheel drive vehicle. Right side view showing the body frame structure of the front half of the front and rear wheel drive vehicle. Front view of the body frame structure of a front and rear wheel drive vehicle as viewed from the front of the vehicle. A perspective view of the body frame structure of the front half of the front and rear wheel drive vehicle as viewed from the front on the left side of the vehicle. A perspective view of the body frame structure of the front half of the front and rear wheel drive vehicle as viewed from the front on the right side of the vehicle. A plan view of the body frame structure of the front half of the front and rear wheel drive vehicle as viewed from above the vehicle. The cross-sectional view which shows the support structure of the front wheel which is a steering wheel of a front and rear wheel drive vehicle, and a motor. An enlarged cross-sectional view showing the motor cross-sectional structure of FIG. A block diagram showing a drive control system provided in a front and rear wheel drive vehicle. (A) is a front view of the cornering running state of the front and rear wheel drive vehicle as viewed from the front front, (B) is a front view of the front and rear wheel drive vehicle taken from the direction A of FIG. 13 (A), and the force during turning of the front tire. The figure which shows the working state. (A) is a map showing the relationship between the accelerator opening of the front and rear wheel drive vehicle and the signal output voltage, and (B) is an example of the drive torque command signal to the motor for driving the steering wheel. A map showing the relationship with the motor target drive torque value. A flow chart showing the flow of drive control during cornering driving by the drive control system of a front and rear wheel drive vehicle. A flow chart showing a flow of drive control when the remaining battery level for driving a motor becomes a predetermined value or less in a drive control system for a front and rear wheel drive vehicle.

Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a front-rear wheel drive vehicle according to an embodiment of the present invention, a left side view of the entire vehicle showing the appearance shape of the front-rear wheel drive vehicle, and FIG. 2 shows the front-rear wheel drive vehicle shown in FIG. 1 in front of the vehicle. 3 is a right side view showing the front half of the front and rear wheel drive vehicle of FIG. 1 as viewed from the front. In these figures, the front and rear wheel drive vehicle 10 is represented by the symbol Fw on the front side of the vehicle and the symbol Bw on the rear side of the vehicle. Is represented by the symbol R, respectively.

[Front and rear wheel drive vehicles]
The front-rear wheel drive vehicle 10 shown in FIGS. 1 to 3 is composed of, for example, a scooter-type motorcycle, and is provided with a front wheel 11 at a lower front portion of the vehicle body and a rear wheel 12 at a lower rear portion thereof. The front wheels 11 function as steering wheels that are steered via the steering mechanism 14 and the link type suspension device 15 (or bottom arm type suspension device) by the rotation operation of the handle 13. The link type suspension device 15 is provided with a motor 16 for driving the drive wheels, and the front wheels 11 also function as drive wheels.

On the other hand, the rear wheels 12 are non-steering wheels and are driven by an engine (not shown) mounted on the vehicle body of the front / rear wheel drive vehicle 10. Therefore, the rear wheels 12 also function as driving wheels.

Therefore, in the front and rear wheel drive vehicle 10 of the present embodiment, the steering wheels are the front wheels 11 driven by the motor, the non-steering wheels are the rear wheels 12 driven by the engine, and the rear wheels 12 driven by the engine by the front wheels 11 driven by the motor. It is a front and rear wheel drive motorcycle that assists. The driving parts of the vehicle are composed of the engine and the motor 16, and the suspension parts of the vehicle are composed of the link type suspension devices 15 and 18 and the shock absorber 55.

Such a front-rear wheel drive vehicle 10 has excellent traction performance due to the front and rear driving wheels, so that stable running performance can be obtained even on a snowy road or a wet road surface, and the ability to run on rough roads is improved. Can be done. Further, the hybrid drive of the motor 16 and the engine makes it possible to achieve both excellent acceleration performance and fuel efficiency.

An engine (not shown) is mounted on the vehicle body of the front-rear wheel drive vehicle 10 shown in FIG. 1, and the driving force of this engine is transmitted to the axles of the rear wheels 12 via a power transmission mechanism (not shown).

The swing arm 17 is swingably supported by a frame pivot (not shown) located at the lower center of the vehicle body of the front / rear wheel drive vehicle 10. Further, the swing arm 17 constitutes a link type suspension device 18 (or a bottom arm type suspension device) that rotatably supports the rear wheel 12 at the rear end portion. The swing arm 17 may be composed of a unit swing type engine in which an engine is installed in the upper part on the front side of the arm and the engine and a power transmission mechanism are integrally provided.

A cowling 20 as a front cover is provided on the front portion of the front and rear wheel drive vehicle 10, and a windscreen 21 is installed above the cowling 20 so as to extend rearward and upward. On the rear side of the cowling 20, the vehicle body is sequentially covered with the leg shield 22, the body side cover 23, and the rear cover 24, and a vehicle body cover that covers the entire vehicle body is configured. The seat 25 is installed above the body side cover 23 and the rear cover 24.

Further, the upper portion of the front wheels 11 which are the steering wheels is covered with the front fender 27, and the headlamp 28 is provided above the front fender 27. Left and right winkers 29 are provided at the lower portions on both sides of the headlamp 28.

The upper portion of the rear wheel 12, which is a non-steering wheel, is covered with the rear fender 31, and the tail lamp 32 is provided above the rear fender 31.

In FIG. 1, reference numeral 35 is a center stand, and reference numeral 36 is a side stand. Reference numeral 37 is a driver step, and reference numeral 38 is a companion step.

[Vehicle front structure]
On the other hand, the front portion of the front / rear wheel drive vehicle 10 is configured as shown in FIGS. 4 to 5. In the front / rear wheel drive vehicle 10, a head pipe 41 is provided at the front end of the vehicle body frame 40 having a down frame structure. A steering shaft 43 constituting the steering mechanism 14 is rotatably provided on the head pipe 41, and the top of the steering shaft 43 is connected to the steering wheel 13. The steering mechanism 14 rotatably supports the steering shaft 43 in the head pipe 41. A front fork 44 is connected to the lower part of the steering shaft 43 below the head pipe 41.

The front fork 44 extends downward so that the fork portions 45a and 45b branched to the left and right straddle the rear side of the front wheel 11. The left and right fork portions 45a and 45b of the front fork 44 are composed of rod-shaped members, and are not provided with a telescopic suspension mechanism. The lower parts of the left and right fork portions 45a and 45b are bent forward of the vehicle, pivots 47 are provided at the lower ends of the left and right fork portions 45a and 45b, and the left and right arm portions of the swing arm 50 are provided on the left and right paired pivots 47. 51a and 51b are swingably supported. The front wheels 11, which are steering wheels, are supported by the arm portions 51a and 51b. In this way, the link type suspension device 15 constitutes a bottom link type or bottom arm type support mechanism for the front wheels 11.

[Front wheel link suspension system]
The link-type suspension device 15 for the front wheels 11 is provided on the vehicle body side with the front fork 44 fixed to the lower part of the steering mechanism 14 of the front and rear wheel drive vehicle 10.

The front fork 44 is bifurcated to the left and right, and a pair of left and right fork portions 45a and 45b are fixed at the left and right bifurcated portions. The lower parts of the fork portions 45a and 45b are connected and integrated with each other by a substantially U-shaped bridge frame 46 that bypasses the rear portion of the front wheel 11 to improve mechanical and physical strength and maintain sufficient rigidity. Will be done.

Further, in the link type suspension device 15 of the steering wheel, the arm portions 51a and 51b of the swing arm 50 extend from the pivot 47, which is the swing fulcrum, to the front side of the vehicle on both sides of the front wheel 11, and the front ends of the arm portions 51a and 51b. The front wheel 11 is supported on the portion.

Further, the left and right arm portions 51a and 51b of the swing arm 50 are integrally connected and reinforced by a substantially U-shaped bridge frame 52 whose rear end portions detour so as to straddle the rear of the front wheel 11. A motor 16 is provided on either the left or right arm portion, for example, the front end portion of the left arm portion 51a, as shown in FIG. The other right arm portion 51b of the swing arm 50 supports the wheel shaft of the front wheel 11 as shown in FIG.

Here, the pair of left and right fork portions 45a and 45b of the front fork 44 are composed of rod-shaped members, and as shown in FIGS. 4 and 7 in the vehicle body side view, the vehicle rear side (Bw side) with respect to the motor 16. It is arranged outside the outer edge of the motor. The front fork 44 is required to have a large rigidity, but by providing the left and right fork portions 45a and 45b on the outside with respect to the outer edge of the motor 16, the left and right forks are not affected by the size, shape and layout of the motor 16. The forks 45a and 45b can be made thicker, which makes it easier to improve the rigidity. Further, by making the width of the left and right fork portions 45a and 45b in the vehicle width direction narrower than the width in the vehicle width direction of the conventional telescopic front fork, the width of the front fork 44 can be kept compact and at the same time operability can be improved. Can be improved.

Further, as shown in FIGS. 3 to 5 and 7 to 9, the swing arm 50 has the front fork 44 side support points of the left and right arm portions 51a and 51b, that is, the pivot 47 on the vehicle rear side (Bw) of the motor 16. On the side), which is provided on the outside with respect to the outer edge of the motor. In this way, the front fork 44 does not directly support the wheel shaft of the front wheel 11, but is arranged offset to the rear side of the vehicle with respect to the rotation shaft of the front wheel 11, and the pivot 47 which is the swing shaft of the swing arm 50. Is positioned away from the motor 16. Therefore, unlike the conventional case, the front wheel 11 is not directly supported by the lower part of the telescopic front fork, and even if the motor 16 becomes large, the expansion of the width of the wheel shaft of the front wheel 11 can be suppressed.

Further, the swing arm 50 is arranged so that the pivot 47 is inside the outer edge of the front wheel 11 in the front wheel radial direction in the vehicle body side view. As a result, the fork portions 45a and 45b of the front fork 44 are arranged so as to approach the wheel shaft of the front wheel 11 while avoiding the motor 16, and the front shock absorber 55 is located on the opposite side of the motor 16. Even when the front wheel 11 is offset only to the right side (one side on the left and right), the twist of the swing arm 50 can be suppressed as much as possible and the support stability of the front wheel 11 can be improved.

Further, since the front fork 44 is arranged so as to extend in the vertical direction apart from the front wheel axle on the vehicle rear side (Bw side) in the vehicle body side view, the front fork 44 requires rigidity. The weight can be brought closer to the center side in the front-rear direction of the vehicle body, and the operability can be improved.

[Front shock absorber and braking device]
A mounting bracket is provided on one of the left and right arm portions of the swing arm 50, for example, the upper tip of the right arm portion 51b near the wheel axis, and between this mounting bracket and the upper front mounting bracket of the right fork portion 45b of the front fork 44. The front shock absorber 55 is attached to the wheel.

Further, a motor 16 is provided on the left side of the front wheel 11, and a braking device 56 is provided on the right side. The braking device 56 includes a brake caliper 57 attached to the right arm portion 51b of the swing arm 50, a brake disc 58 attached to the right wheel hub of the front wheel 11, and a brake pad 59 provided on the brake caliper 57. .. The braking device 56 brakes by the brake pads 59 sandwiching the brake disc 58.

Here, in the front / rear wheel drive vehicle 10 of the present embodiment, the link type suspension device 15 is used for suspending the front wheels 11 which are the steering wheels. By adopting this structure, it is not necessary to provide a telescopic fork portion having cushioning mechanisms on both the left and right sides unlike the conventional telescopic front fork, and the front shock absorber 55 can be attached to the swing arm 50, for example, the right arm portion 51b. It is possible to have a suspension structure that is placed only on the floor. As shown in FIGS. 6 to 9, a heavy motor 16 is located on the left side (L side) of the front wheel 11 with the steering center axis Sc of the steering shaft 43 sandwiched between the left and right sides, and the front wheel 11 on the opposite side is located. A front shock absorber 55 (which is lighter than the motor 16) and a braking device 56 are provided on the right side (R side), respectively. By separately mounting the motor 16, the front shock absorber 55, and the braking device 56 on the left and right arm portions 51a and 51b of the swing arm 50, respectively, the left and right weight balance around the steering shaft 43 of the vehicle is improved. It will be easier to keep.

Further, the front fork 44 is provided on the vehicle rear side of the motor 16 and the front shock absorber 55, and the left and right pair of fork portions 45a and 45b of the front fork 44 do not straddle the motor 16 and the front shock absorber 55. Therefore, the width of the front fork 44 in the vehicle width direction can be made narrower and more compact than that of the conventional telescopic front fork.

Further, since the front shock absorber 55 can be arranged only on one side of the swing arm 50, for example, the right arm portion 51b, even if the motor 16 is provided on the left arm portion 51a as shown in FIGS. 6 to 9. The front shock absorber 55 can be easily arranged on the right arm portion 51b without interfering with the motor 16.

Moreover, by not providing the front shock absorber on the left arm portion 51a, there are less restrictions on the layout and size of the motor 16, and the degree of freedom in the arrangement of the motor 16 and the design of the motor parts is further improved. Can be done.

Further, unlike the conventional telescopic front fork in which the motor is sandwiched between the suspension mechanisms on both the left and right sides, the front wheels 11 are supported by the left and right arm portions 51a and 51b of the narrow swing arm 50 to form a link type. The width of the suspension device 15 in the vehicle width direction can be narrowed. As a result, the inertia around the steering center axis Sc during steering of the steering wheel 13 can be suppressed to a small value, and the operability is improved.

In this way, by mounting the front wheel shaft side mounting position of the single front shock absorber 55 on the right arm portion 51b of the swing arm 50, the degree of freedom of mounting is improved and the optimum layout around the front wheel shaft is facilitated. Can be done.

For example, as shown in FIGS. 4 and 5, when viewed from the side of the vehicle body, the single front shock absorber 55 has a mounting portion with the other side arm portion of the swing arm 50, for example, the right arm portion 51b, from the outer edge of the motor 16. Is also provided inside. By arranging the mounting position so as to overlap the motor 16 in this way, the motor 16 and the shock absorber 55, which are heavy objects, are gathered and arranged near the front wheel axle, and the inertia during steering is suppressed to improve the operability. Can be made to.

In addition, by arranging the mounting positions slightly apart from the front wheel axles, the motor 16 can be easily arranged while avoiding the occupied area in the vehicle width direction, and can be easily arranged in the vehicle width direction, and eventually in the front wheel axle direction. Width can be suppressed. Further, by arranging the mounting position on the wheel shaft side downward, it is possible to secure a sufficient stroke length, excellent shock absorption, and improve vehicle body stability and comfort.

Further, the braking device 56 is arranged together with the single shock absorber 55 on the opposite side of the motor 16, that is, on the right side of the front wheel 11. Therefore, as shown in FIG. 6, in addition to arranging the motor 16 and the motor support structure on the left side of the front wheel 11 and the single shock absorber 55 on the right side of the front wheel 11 with respect to the steering central axis Sc. By arranging the braking device 56 on the right side as well, it is possible to maintain a good left-right weight balance of the vehicle with respect to the heavy motor 16.

In addition, since the motor 16 and the braking device 56 are distributed and arranged on the left and right sides of the front wheel 11, even if the outer diameter of the motor 16 is increased, there are few restrictions on the mounting of the braking device 56, and both can be mounted freely. The degree can be improved.

Although the braking device 56 is shown as an example composed of the brake caliper 57, the brake disc 58, and the brake pad 59, the braking device may be composed of a brake drum, a brake shoe, or the like.

[Motor mounting structure]
As shown in FIGS. 7 to 9, the motor 16 for driving the front wheels 11 is installed on the swing arm 50 of the link type suspension device 15 provided in the lower part of the steering mechanism 14. The motor 16 is attached to either the left or right arm portion of the swing arm 50, for example, the left arm portion 51a. In the motor 16 attached to the left arm portion 51a, the motor body 60 is covered with the motor cover 61 from the outside of the vehicle when viewed from the side of the vehicle. The motor cover 61 is integrally fixed to the tip of the left arm portion 51a of the link type suspension device 15, and is fixed to the vehicle body side via the swing arm 50 and the front fork 44.

The motor 16 is composed of a motor main body 60, a motor cover 61, and an inner cover 62, and the inner cover 62 is fastened to the motor cover 61 with a plurality of motor mounting bolts 63 with the motor main body 60 inside and integrated. The motor 16 is installed on one of the left and right sides of the front wheel 11, which is a steering wheel, for example, on the left side.

[Motor structure]
The swing arm 50 is swingably supported under the link type suspension device 15 of the steering wheel, and the motor 16 provided on one arm portion of the swing arm 50, for example, the left arm portion 51a, is shown in FIGS. 10 and 11. It is configured as shown. The motor main body 60 housed in the motor cover 61 has a stator 65 fixed to the motor main body 60 and a rotor 66 that faces the stator 65 and is supported by the motor main body 60 so as to be relatively rotatable. Is rotationally integrated with the motor (internal) shaft 67. The motor shafts 67 are provided side by side in the axial direction so as to form a common shaft with the wheel shafts 68 of the front wheels 11.

The motor shaft 67, which is rotationally integrated with the rotor 66, is rotatably supported on both sides in the axial direction by bearings 69a and 69b. The motor shaft 67 of the motor 16 has a sun gear portion and meshes with the planetary gear 70. The planetary gear 70 meshes with a ring gear 79 that is provided on the outside thereof and does not rotate. The planetary gear carrier 71 is integrally provided at the end of the wheel shaft 68 on the motor side to hold the planetary gear 70 rotatably, and rotates coaxially with the motor shaft 67 by the rotational movement of the planet gear 70 around the motor shaft 67. Both sides of the wheel shaft 68 in the axial direction are rotatably supported by bearings 72a and 72b, and the wheel shaft 68 and the motor shaft 67 are provided so as to be relatively rotatable by bearings 69b.

Then, by driving the motor 16, the rotational driving force of the rotor 66 is decelerated from the motor shaft 67 by the planetary gear 70 and transmitted to the wheel shaft 68, and further transmitted to the wheel hub 74 via the power transmission member 73, and the front wheels. 11 is driven. Here, the motor 66 is driven to assist, for example, the engine.

As shown in FIGS. 10 and 11, the wheel spokes 76 connecting the wheel rim 75 of the front wheel 11 and the wheel hub 74 are curved in an arc shape as a whole, and the motor 16 is installed in the curved recess of the wheel spokes 76. Wheel. A boss 77 projecting outward from the front wheel 11 is formed on the wheel spoke 76 or the wheel hub 74, and the brake disc 58 is attached to and fixed to the protruding boss 77. Reference numeral 78 is an oil seal.

[Rear wheel link suspension system]
By the way, in the front and rear wheel drive vehicle 10 of the present embodiment, as shown in FIG. 1, the rear wheels 12, which are non-steering wheels, function as engine-driven drive wheels. The rear wheel 12 is oscillatingly supported by a bottom arm type suspension device or a link type suspension device 18. The link-type suspension device 18 has a swing arm 17 that is swingably supported around a frame pivot (not shown) at the lower center of the vehicle body of the front / rear wheel drive vehicle 10. The swing arm 17 extends to the rear side of the vehicle, the arm portion is branched to the left and right from the middle, and the rear wheel 12 is supported by the rear end portions of the left and right arm portions.

In the front and rear wheel drive vehicle 10, an engine (not shown) is suspended on a vehicle body frame below the seat 25, and the driving force of this engine is transmitted to the rear wheels 12 via a power transmission mechanism such as a chain mechanism or a belt mechanism, and the rear wheels. 12 is driven. The engine may be provided on the upper front side of the swing arm 17. When the engine is provided on the swing arm 17, the driving force of the engine is transmitted to the rear wheels 12 via the power transmission mechanism of the stepless change mechanism and the reduction mechanism. The swing arm 17 is configured as a unit swing type engine.

Further, a single rear shock absorber (not shown) is provided between the left and right arm portions of the swing arm 17 and the vehicle body frame 40.

Further, in the front / rear wheel drive vehicle 10 of the present embodiment, the rear wheels 12 may be driven by a motor instead of being driven by an engine. When the rear wheel 12 is driven by a motor, for example, a motor is provided on one arm portion of the swing arm 17, and a single rear shock absorber provided between the other arm portion and the vehicle body side is provided. As shown in FIG. 9, the center of gravity of the motor is provided on either the left or right side in the vehicle width direction with respect to the vehicle body center line BCL, for example, on the left side, and a single rear shock absorber and braking device are provided on the right side on the opposite side. Provided.

[Drive control system for front and rear wheel drive vehicles]
In the front and rear wheel drive vehicle 10, the drive source of the front wheels 11 is the motor 16, and the drive source of the rear wheels 12 is the engine. In the front / rear wheel drive vehicle 10, for example, as shown in FIG. 1, the motor output and the engine output are controlled by the drive control system 80 mounted below the seat 25 or below the rear end of the seat rail of the vehicle body.

As shown in FIG. 12, the drive control system 80 controls an engine control unit (hereinafter referred to as an ECU) 81 that controls engine output by controlling engine ignition timing, fuel injection amount, injection time, and the like, and motor output. It is provided with a motor control unit (hereinafter referred to as an MCU) 82. The front and rear wheel drive vehicle 10 includes an electric throttle valve and a fuel injection (FI) system, and the engine, motor, and the like are controlled by the ECU 81. The drive control system 80 is resistant to vibration and water and has high weather resistance so that the core ECU 81 and MCU 82 are composed of a computer, the internal base is covered with resin, and the front and rear wheel drive vehicles 10 can be used. Has been done.

The front and rear wheel drive vehicle 10 has a throttle position sensor 85 that measures the throttle valve opening as various sensors 88 of the fuel injection system, an intake pressure sensor 86 that measures the intake air amount, and an O ₂ concentration in the exhaust gas in each part of the vehicle body. Vehicles equipped with sensors such as the O ₂ sensor 87 for measurement, and further equipped with a mission mechanism, are equipped with a gear position sensor 90 for measuring the gear coefficient, an accelerator position sensor 92 for measuring the accelerator operation amount of the operator, and a motor. A motor hole sensor 94 that detects the rotor position, a vehicle gyro sensor 95 that is an angular speed sensor of the vehicle body, a vehicle acceleration sensor 96 that measures the acceleration of the vehicle body, a battery status sensor 97 that measures the remaining battery level, and the like are provided.

Of these, the sensor signals of the various fuel injection system sensors 88, the gear position sensor 90, and the accelerator position sensor 92 are input to the ECU 81. The ECU 81 estimates the output state of the engine based on each sensor information, and controls the engine output such as the optimum throttle valve opening degree, ignition timing, and fuel discharge amount in order to obtain the target drive torque with respect to the accelerator position sensor output. As a result, the target drive torque of the rear wheels 12 is controlled.

Further, the sensor information of the accelerator position sensor 92, the motor hole sensor 94, the vehicle gyro sensor 95, the vehicle acceleration sensor 96, and the battery status sensor 97 is input to the MCU 82. The MCU 82 estimates the output state of the motor and the remaining battery level based on each sensor information, and further estimates the vehicle motion state including the inclination angle (bank angle) of the vehicle. Then, the target drive torque of the motor 16 according to the vehicle motion state is determined by using the accelerator position sensor output and the estimation result of the vehicle motion state, and the inverter and the battery (both not shown) are based on the motor target drive torque. Control. As a result, the target drive torque of the front wheels 11 is controlled.

On the other hand, the MCU 82 and the ECU 81 are linked to each other to control the operation. The MCU 82 determines the required drive torque for the engine based on the motor target drive torque and sends it to the ECU 81. The ECU 81 corrects the target drive torque of the engine by using the required drive torque for the engine, and controls the engine output.

Further, the range of the motor target drive torque can be determined by the MCU 82 based on the increase in the engine target drive torque set by the ECU 81. In this case, the ECU 81 determines the engine target drive torque with respect to the accelerator opening, estimates the increase in the rear wheel target drive torque at this time, and sends it to the MCU 82. Based on the obtained increase in the target drive torque for the rear wheels, the MCU 82 controls the target drive torque for the motor so that the target drive torque for the front wheels falls within a range that is sufficiently smaller than the increase.

[Overview of vehicle drive control]
As described above, in the front / rear wheel drive vehicle 10, when the operator performs an acceleration operation while the vehicle body is tilted and turned (hereinafter, cornering running), the steering is steered by the increasing driving force of the front wheels 11. A moment in the direction opposite to the direction may act to give the operator a sense of discomfort, but in the drive control system 80 of the present embodiment, the target drive torque of the front wheels 11 (and the rear wheels 12) during the acceleration operation of the operator This problem is solved by appropriately performing adjustment control.

In the front / rear wheel drive vehicle 10 of the present embodiment, the MCU 82 of the drive control system 80 estimates the bank angle α of the vehicle based on the sensor information of the vehicle gyro sensor 95 and the vehicle acceleration sensor 96, and the operator during cornering travel. When there is an acceleration operation such as the throttle opening operation, the control is performed so as to reduce the target drive torque of the front wheels 11 as compared with the case where the same acceleration operation is performed during the upright running.

Further, in the front-rear wheel drive vehicle 10 of the present embodiment, the MCU 82 of the drive control system 80 is controlled so as to increase the reduction range of the target drive torque with respect to the acceleration operation of the operator as the bank angle of the vehicle increases. ..

By controlling the motor target drive torque by the MCU 82 of the drive control system 80 in this way, the influence of the increase in the driving force of the front wheels 11 due to the acceleration operation of the operator during cornering driving on the steering behavior is reduced, and the driver's discomfort is eliminated. Then, it can be operated with a feeling similar to that of a normal rear-wheel drive two-wheeled vehicle.

In addition, by changing the motor target drive torque for acceleration operation between the bank state and the upright running state of the vehicle, in the upright running state, the responsiveness of the motor 16 and the controllability of the low-speed torque are utilized to exert the acceleration force. , The change in the behavior of the handle 13 during cornering running can be suppressed, and stable running can be obtained.

Further, in the drive control system 80, the driving forces of the front and rear wheels are linked to each other, and control is performed so that a sufficient driving force can be obtained from the rear wheels 12 even if the increase in the driving force of the front wheels 11 is limited. When the motor target drive torque is controlled by the MCU 82 of the drive control system 80 and the front wheel target drive torque is reduced, the engine target drive torque is increased by the ECU 81 to increase the rear wheel target drive torque. At this time, the ECU 81 controls so as to increase the rear wheel target drive torque based on the limit of the front wheel target drive torque controlled by the MCU 82. For example, the rear wheel target drive torque is increased up to the front wheel target drive torque limit.

As a result, the driving control is performed so that the driving force of the rear wheels 12 increases by the amount that limits the increase in the driving force of the front wheels 11 when the vehicle is banked, so that a sufficient acceleration force can be obtained as in the upright running state. ..

Further, in the drive control system 80, the ECU 81 determines the engine target drive torque with respect to the accelerator opening to control the rear wheel target drive torque in response to the acceleration operation when the vehicle is banked, while increasing the rear wheel target drive torque. Based on this, the MCU 82 performs reduction control of the motor target drive torque so that the front wheel target drive torque falls within a range sufficiently smaller than the increase in the rear wheel target drive torque. As a result, the accuracy of the driving force distribution control of the front and rear wheels can be improved without providing an additional sensor on the engine side, and the amount of front wheel assist by the motor can be increased.

On the other hand, in the drive control system 80 of the front and rear wheel drive vehicle 10 of the present embodiment, even when the vehicle is running in an upright state, when the remaining amount of the battery for driving the motor is less than a certain value, the power consumption is suppressed and the battery is charged. For this purpose, the MCU 82 controls to reduce the front wheel target drive torque. On the other hand, the ECU 81 acquires the motor output limit from the MCU 82, and controls to increase the rear wheel target drive torque up to this limit.

In this way, in the drive control system 80, when the remaining battery level is low, the output of the motor 16 is reduced to suppress power consumption, and instead, the engine speed is increased to improve the output, thereby shifting the battery to a charged state. It becomes easy to keep the driving force of the entire vehicle at a desired driving force.

[Maneuvering characteristics when driving front wheels]
From here, we will explain what kind of effect the above-mentioned control has and how it is performed concretely. In the front / rear wheel drive vehicle 10, as shown in FIG. 13A, in the bank state during cornering, the tire contact patch Td of the front wheels 11 which are the steering wheels is inside (IN side) in the turning direction from the steering shaft center Sc. Therefore, in a normal rear-wheel drive vehicle, when the throttle is opened, the moment around the steering axis center Sc is in the Mi direction due to the running resistance Rr that acts on the tire contact patch Td in the direction opposite to the traveling direction. It works to generate a force that rotates inward in the turning direction.

However, when a driving force D is applied to the front wheels and the driving force D overcomes the running resistance Rr, the moment M around the center Sc of the steering shaft acts in the opposite direction (Mo direction), and the steering is outside the turning direction (OUT). A rotating force is generated on the side). Note that G is the front center of gravity of the front and rear wheel drive vehicle, and reference numeral T is a trail point at the center Sc of the steering shaft. Reference numeral l is a distance in the width direction between the steering shaft center Sc and the front tire contact patch Td.

In the case of a normal rear-wheel drive vehicle, even if the operator opens the accelerator to accelerate in the bank state, the direction of the force does not change, and only the increase or decrease in running resistance acts. When front-wheel drive is used, when the operator opens the accelerator and accelerates in the bank state, as shown in FIG. 13B, when a driving force D that overcomes the running resistance Rr applied to the tire contact surface Td is generated, The direction of the steering torque required for maneuvering will change, and in a vehicle in which the driving force D is added to the steering wheels, the moment M = {distance l × (driving force D-running resistance force Rr) around the center Sc of the steering shaft. } Acts in the Mo direction in FIG. 13B, so that the steering changes its behavior in response to a force that rotates outward in the turning direction.

Therefore, in the vehicle in which the driving force D is added to the front wheels 11, the steering behavior changes depending on the magnitude of the change in the driving force D with respect to the traveling resistance force Rr in the bank state. However, the front and rear wheel driving of the present embodiment In the vehicle 10, when the vehicle is in the bank state, the front wheel target drive torque is reduced as compared with the upright running state by controlling the MCU 82 of the drive control system 80 as described above, so that the steering axis center Sc is relative to the steering axis center Sc. The moment M in the Mo direction exerted by the driving force D is suppressed. Therefore, the influence on the steering behavior is alleviated, and good turning performance can be obtained with a feeling similar to that of a conventional rear-wheel drive vehicle.

[Flow of vehicle drive control]
FIG. 14 illustrates an output map that controls a target drive torque command to the motor 16 when the front wheels 11 are driven by the motor. FIG. 14A is a map showing the relationship between the accelerator opening degree detected by the accelerator position sensor 92 and the output voltage as the target drive torque command signal. FIG. 14B is a map showing the relationship between the accelerator opening degree and the motor target drive torque value in a predetermined range.

In FIG. 14B, the solid line P shows the relationship between the accelerator opening degree and the motor target drive torque value in the upright running state. On the other hand, the dotted line Q shows the relationship between the motor target drive torque value and the accelerator opening at a predetermined bank angle. As shown in the solid line P, the target drive torque value of the motor 16 during upright running increases linearly as the accelerator opening increases, and is set to be constant when the accelerator opening exceeds a predetermined position S. However, the target drive torque value in the bank state is set lower than the target drive torque value in the upright running state at the same accelerator opening as shown by the dotted line Q, and the reduction width increases as the accelerator opening increases. Moreover, when the accelerator opening exceeds the predetermined position R (smaller than S), the target drive torque value becomes constant. By the way, the target drive torque value in the bank state is set to be similar to the above-mentioned dotted line Q for an arbitrary bank angle α, but the larger the bank angle α is, the more the target drive torque value in the upright running state (solid line P). The amount of reduction is expanded.

In this way, the motor target drive torque value for the operator's accelerator operation in the bank state of the vehicle is suppressed to a smaller value than in the upright driving state to reduce the front wheel target drive torque, thereby suppressing changes in steering behavior and the vehicle body. Stability can be improved.

In the embodiment of the present invention, the flow of drive control of the front wheels 11 and the rear wheels 12 by the drive control system 80 is, as shown in FIG. 15, first in step 1 (S1), the accelerator is opened by the acceleration operation of the operator. It is determined whether the degree is equal to or higher than a predetermined threshold. If the accelerator opening degree is less than the predetermined threshold value (No), the process returns to step 1 (S1).

If the accelerator opening is equal to or greater than a predetermined threshold (Yes), the process proceeds to step 2 (S2). Here, the bank angle α of the vehicle is estimated by the MCU 82 based on the sensor signals from the vehicle gyro sensor 95 and the vehicle acceleration sensor 96.

Next, in step 3 (S3), it is determined whether or not the estimated bank angle α of the vehicle exceeds a predetermined angle. If the bank angle α of the vehicle exceeds a predetermined angle (Yes), it is considered that the vehicle is in the bank state, and the process proceeds to step 4 (S4).

In step 4 (S4), the motor target drive torque value with respect to the accelerator opening is reduced as compared with the value in the upright running state (shift from the state of the solid line P in the graph of FIG. 14B to the state of the dotted line Q). , Control to reduce the front wheel target drive torque. Here, the reduction range of the motor target drive torque value is controlled so as to increase as the bank angle α of the vehicle increases.

In step 5 (S5), the required drive torque for the engine is determined based on the motor target drive torque reduction amount set by the MCU 82, and is sent to the ECU 81. Then, the ECU 81 uses the required drive torque for the engine to correct the engine target drive torque with respect to the accelerator opening in a direction of increasing, and controls to increase the rear wheel target drive torque. Here, the MCU 82 determines the required drive torque for the engine so that the increase in the rear wheel target drive torque is within a range in which the front wheel target drive torque reduction amount is the upper limit.

On the other hand, if the bank angle α of the vehicle does not exceed the predetermined angle (No) in step 3 (S3), it is considered that the vehicle is in an upright running state, and the process proceeds to step 7 (S7).

In step 6 (S6), contrary to step 4 (S4), the motor target drive torque value with respect to the accelerator opening is returned to the value in the upright running state (the state of the solid line P in the graph of FIG. 14B) ( Or maintain) and control the front wheel target drive torque.

In step 7 (S7), the control for increasing the engine target drive torque value with respect to the accelerator opening is finished, and the increase in the rear wheel target drive torque is finished.

In this way, the drive control system 80 controls to reduce the front wheel target drive torque with respect to the accelerator opening degree according to the magnitude of the bank angle α when the vehicle is in the bank state. As a result, even when the operator performs the acceleration operation in the bank state, it is possible to reduce the action of the moment acting in the direction opposite to the turning direction acting on the steering by the driving force of the front wheels 11, and the behavior of the steering changes. The effect is mitigated and good turning performance is obtained.

Further, when the front wheel target drive torque is reduced, control is performed to increase the rear wheel target drive torque so as to compensate for the reduction. As a result, the vehicle can obtain a stronger driving force while improving the turning performance during cornering. In addition, the increase / decrease in the driving force of the entire front and rear wheels is suppressed, and smooth acceleration without discomfort is possible.

Further, the arithmetic processing means 101 of the ECU 81 adjusts the rear wheel driving force within a range not exceeding the adjustment amount of the front wheel driving force. As a result, even during cornering driving, it is possible to obtain a driving force that is close to the original driving force of the vehicle as in the upright running state and is just enough.

Further, in the drive control system 80, although not shown in the figure, the range of the motor target drive torque is determined based on the increase in the engine target drive torque when the operator accelerates the operation in the bank state of the vehicle. You can also do it. In this case, the ECU 81 determines the engine target drive torque with respect to the accelerator opening, estimates the increase in the rear wheel target drive torque at this time, sends it to the MCU 82, and the MCU 82 calculates the increase in the obtained rear wheel target drive torque. Based on this, the reduction control of the motor target drive torque is performed so that the front wheel target drive torque falls within a predetermined range that is sufficiently small with respect to the increase. By providing this control step between steps 3 (S3) and 4 (S4) of the drive control flow of FIG. 15, for example, reduction control of the motor target drive torque can be effectively performed.

In this way, the ECU 81 determines the engine target drive torque and controls the rear wheel target drive torque, while the MCU 82 also utilizes the obtained information on the increase in the rear wheel target drive torque to reduce the motor target drive torque. By doing so, the accuracy of the driving force distribution control of the front and rear wheels can be improved without providing an additional sensor on the engine side, and the amount of front wheel assist by the motor can be increased.

Further, in the front and rear wheel drive vehicle 10 of the present embodiment, the motor 16 for driving the front wheels 11 uses a battery as a power source. The remaining state of the battery is measured by the battery status sensor 97. The measured battery level information is sent to the MCU 82 of the drive control system 80.

In the drive control system 80, drive control of the front wheels 11 and the rear wheels 12 is performed according to the remaining battery level. As shown in FIG. 16, in the drive control flow (2), first, in step 8 (S8), the MCU 82 determines whether or not the remaining battery level C is below a predetermined value based on the measured remaining battery level information. To do.

If the remaining battery level C is less than the predetermined value (Yes), the process proceeds to step 9 (S9), and control is performed to reduce the front wheel target drive torque. At this time, the MCU 82 reduces the motor target drive torque by a predetermined amount, and controls to reduce the front wheel target drive torque.

Next, in step 10 (S10), the required drive torque for the engine is determined based on the motor target drive torque reduction amount set by the MCU 82, and is sent to the ECU 81. Then, the ECU 81 uses the required drive torque for the engine to correct the engine target drive torque in the direction of increasing, and controls to increase the rear wheel target drive torque. Here, the MCU 82 determines the required drive torque for the engine so that the increase in the rear wheel target drive torque is within a range in which the front wheel target drive torque reduction amount is the upper limit.

On the other hand, if the remaining battery level C does not fall below the predetermined value (No) in step 8 (S8), the process proceeds to step 11 (S11), and contrary to step 9 (S9), the motor target drive torque value is reduced. The control is finished, and the reduction of the front wheel target drive torque is finished.

In step 12 (S12), the engine target drive torque value increase control is ended, and the rear wheel target drive torque increase is ended.

As described above, in the drive control system 80, when the remaining battery amount C for driving the motor is less than a predetermined value, the motor target drive torque is reduced to limit the driving force of the front wheels 11 in order to reduce power consumption and charge the battery. At the same time, control is performed to increase the engine target drive torque so as to increase the driving force of the rear wheels 12 up to the limit. As a result, the driving force of the entire vehicle can be maintained constant while charging the battery. The drive control based on the remaining battery level can be performed regardless of whether the vehicle is in the bank state or in the upright running state.

In the embodiment of the present invention, the front and rear wheel drive vehicle is an example of a motorcycle with one front and one wheel, but if the vehicle has a structure in which the vehicle is banked during cornering and the steering wheels are tilted, the front one wheel is used. It can also be applied to other types of saddle-mounted vehicles, such as motorcycles consisting of two rear wheels.

Further, in the embodiment of the present invention, an example of a front / rear wheel drive vehicle in which the drive source of the steered wheels is a motor and the drive source of the non-steering wheels is an engine is shown, but the drive source of the non-steering wheels is also a motor. It may be.

As described above, the embodiments of the present invention are presented as examples, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof. For example, regarding the configuration of the drive control system, in the embodiment of the present invention, an example in which the ECU and the MCU are integrated and the functions are shared inside the system is shown, but the ECU and the MCU may be configured separately. As described above, the internal configuration of the drive control system and the division of functions of each can be appropriately changed without departing from the gist of the invention.

10 ... Front and rear wheel drive vehicle (motorcycle), 11 ... Front wheel (steering wheel, driving wheel), 12 ... Rear wheel (non-steering wheel, driving wheel), 13 ... Handle, 14 ... Steering mechanism, 15 ... Link type suspension system (Bottom Arm Suspension Device), 16 ... Motor, 17 ... Swing Arm, 18 ... Link Suspension Device (Bottom Arm Suspension Device), 20 ... Cowling, 21 ... Windscreen, 22 ... Leg Shield, 23 ... Body Side Cover , 24 ... Rear cover, 25 ... Seat, 27 ... Front fender, 28 ... Head lamp, 29 ... Winker, 31 ... Rear fender, 32 ... Tail lamp, 35 ... Center stand, 36 ... Side stand, 37 ... Driver step, 38 ... Accompanied Steps for people, 40 ... Body frame, 41 ... Head pipe, 43 ... Steering shaft, 44 ... Front fork, 45a, 45b ... Fork part, 46 ... Bridge frame, 47 ... Pivot, 50 ... Swing arm, 51a, 51b ... Arm Part, 52 ... Bridge frame, 55 ... Front shock absorber, 56 ... Braking device, 57 ... Brake caliper, 58 ... Brake disc, 59 ... Brake pad, 60 ... Motor body, 61 ... Motor cover, 62 ... Inner cover, 63 ... Motor mounting bolt, 65 ... stator, 66 ... rotor, 67 ... motor (internal) shaft, 67b ... sun gear, 68 ... wheel shaft, 69a, 69b ... bearing, 70 ... planetary gear, 71 ... planetary gear carrier, 72a, 72b ... Suspension, 73 ... Power transmission member, 74 ... Wheel hub, 75 ... Wheel rim, 76 ... Wheel spoke, 78 ... Oil seal, 80 ... Drive control system, 81 ... Engine control unit (ECU), 82 ... Motor control unit ( MCU), 85 ... Throttle position sensor, 86 ... Intake pressure sensor, 87 ... O ₂ sensor, 88 ... Various fuel injection (FI) system sensors, 90 ... Gear position sensor, 92 ... Accelerator position sensor, 94 ... Motor hole sensor, 95 ... Vehicle gyro sensor, 96 ... Vehicle acceleration sensor, 97 ... Battery status sensor.

Claims (6)

A front-rear wheel drive vehicle that has drive wheels on the front and rear wheels, one of which is the steering wheel, and runs only on the front and rear drive wheels. Tires when the vehicle body tilts to the left or right when the vehicle turns. It is a drive control system installed in a vehicle that travels by moving the ground contact point to the inside of the steering shaft in the turning direction.
The drive control system is a control that reduces the target drive torque of the steering wheel with respect to the accelerator operation amount during the acceleration operation of the operator when the vehicle is in the bank state, as compared with the case where the vehicle is in the upright running state. A drive control system for front and rear wheel drive vehicles, characterized in that The drive control system for a front / rear wheel drive vehicle according to claim 1, wherein the drive control system is controlled to increase the reduction width of the target drive torque of the steering wheels as the bank angle of the vehicle increases. When the vehicle is in the bank state, the motor target drive torque value is set to be constant when the accelerator opening exceeds a predetermined position, and the motor target drive torque value is set to be constant when the vehicle is in the upright state. The drive control system for a front and rear wheel drive vehicle according to claim 1, which is set to be smaller than the target drive torque value of the motor. A front-rear wheel drive vehicle that has drive wheels on the front and rear wheels, one of which is the steering wheel, and runs only on the front and rear drive wheels. Tires when the vehicle body tilts to the left or right when the vehicle turns. It is a drive control method for front and rear wheel drive vehicles that travel by moving the ground contact point to the inside of the steering axis in the turning direction.
When the vehicle is in the bank state, the control is performed to reduce the target drive torque of the steering wheel with respect to the accelerator operation amount during the acceleration operation of the operator, as compared with the case where the vehicle is in the upright running state. Drive control method for front and rear wheel drive vehicles. The drive control method for a front / rear wheel drive vehicle according to claim 4, wherein when the vehicle is in a bank state, control is performed to increase the reduction width of the target drive torque of the steering wheels as the bank angle of the vehicle increases. .. When the vehicle is in the bank state, the motor target drive torque value is set to be constant when the accelerator opening exceeds a predetermined position, and the motor target drive torque value is set to be constant when the vehicle is in the upright state. The drive control method for a front-rear wheel drive vehicle according to claim 4, wherein the motor is set to be smaller than the target drive torque value.

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