JP2010036808A - Vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid type vehicle for effectively suppressing vibration caused by the power fluctuation of an engine. <P>SOLUTION: A power unit 3 is provided with: an engine 25; a power generator 27 for generating a power with the power of the engine 25; an electricity accumulation unit 55 for accumulating a power to be generated by the power generator 27; and an electric motor 26 for generating a power with electricity accumulated by the electricity accumulation unit 55. A power control unit 65 controls the power generation load of the power generator 27 and the generation torque of the electric motor 26 so that the power fluctuation of the engine 25 is compensated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle using an engine and an electric motor as power sources.

2. Description of the Related Art A hybrid type vehicle that can transmit a driving force generated by an engine and an electric motor to a driving shaft in common is known. For example, Patent Document 1 discloses a parallel hybrid vehicle. In a parallel hybrid vehicle, only the electric motor is used as a power source in an operation region where the load is small, and the engine is started when the load increases. Therefore, it may be necessary to start the engine with a heavy load during traveling. Due to the torque fluctuation at the start of the engine, vibration occurs. In the invention of Patent Document 1, a torque for suppressing vibration at the time of engine start is generated from an electric motor.
Japanese Patent No. 3454167

In the prior art of Patent Document 1, vibration at the time of starting the engine is suppressed, but no countermeasure is taken against vibration generated from the engine after starting.
However, torque fluctuations also occur during the combustion cycle of the engine, and vibration due to the torque fluctuations may be a problem. In particular, an engine mounted on a two-wheeled vehicle has a small number of cylinders and a single-cylinder engine may be mounted, so that torque fluctuation during a combustion cycle is large. Therefore, in order to improve passenger comfort and quietness, it is preferable to suppress engine vibration even in a steady operation state after starting.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a hybrid type vehicle that can effectively suppress vibration caused by engine power fluctuation.

  A vehicle according to the present invention includes a drive shaft that supports wheels, an engine, a generator that generates power using the power of the engine, a power storage unit that stores power generated by the power generator, and power stored in the power storage unit. An electric motor that generates motive power, a transmission mechanism that transmits motive power of the engine and the electric motor to a drive shaft, and a power generation load of the generator and a torque generated by the electric motor so as to compensate for power fluctuations of the engine. Power control unit to control.

  According to this configuration, electric power is stored in the power storage unit by driving the generator with the power of the engine. The electric motor is driven by the electric power stored in the power storage unit. The power of the engine and the electric motor is transmitted to the drive shaft by the transmission mechanism. Thus, a hybrid type vehicle is configured. The generator load of the generator and the generated torque of the electric motor (hereinafter referred to as “motor torque”) are controlled so as to compensate for engine power fluctuations. Thereby, the vibration resulting from the engine power fluctuation can be suppressed, and the comfort of the passenger and the quietness of the vehicle can be enhanced. Of course, not only when the engine is started, but also in a steady operation state after starting, control of the power generation load and motor torque can compensate for engine power fluctuations and suppress vehicle vibration.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a side view for explaining the configuration of a motorcycle that is a vehicle according to an embodiment of the present invention, showing a configuration in which exterior parts such as a front cover, a leg shield, and a side cover are removed. Yes.
The motorcycle 1 includes a body frame 2, a power unit 3, a front wheel 4, and a rear wheel 5. A head pipe 6 is provided at the front portion of the vehicle body frame 2. A front fork 7 is supported on the head pipe 6 so as to be swingable in the left-right direction. A front wheel 4 is pivotally supported at the lower end of the front fork 7. A handle 8 for steering the motorcycle 1 is fixed to the upper end of the front fork 7.

  A saddle type seat 9 for two persons is attached to the rear upper part of the body frame 2. A unit swing type power unit 3 is attached to the rear lower portion of the body frame 2 so as to be freely movable up and down. More specifically, a pair of suspension members 10 are provided on the left and right below the rear part of the body frame 2. The power unit 3 is provided with a pair of left and right pivot portions 11. Each pivot portion 11 includes a pivot shaft 12 extending in the left-right direction. The pivot shaft 12 is inserted through an insertion hole formed in the suspension member 10. Thus, the power unit 3 is supported with respect to the vehicle body frame 2 so as to be swingable up and down around the pivot shaft 12. A rear wheel 5 is pivotally supported at the rear end of the power unit 3.

Although not shown, the body frame 2 has the front side of the head pipe 6 covered with a front cover, the rear side of the head pipe 6 covered with a leg shield, and the lower periphery of the seat 9 covered with a side cover. It has been broken.
FIG. 2 is an enlarged side view of the power unit 3, and FIG. 3 is a plan view showing a partial cross section of the power unit 3. The power unit 3 includes a hybrid prime mover unit 20 (hereinafter simply referred to as “prime mover unit 20”) and a transmission case 22 in which a continuously variable transmission mechanism 21 is housed, and these are integrated.

  The prime mover unit 20 includes an engine 25, an electric motor 26, and a generator 27. The engine 25 is, for example, a water-cooled single cylinder engine, and is configured by coupling a crankcase 30, a cylinder block 31, and a cylinder head 32. That is, the cylinder block 31 is coupled to the crankcase 30, and the cylinder head 32 is coupled to the cylinder block 31. A crankshaft 34 is rotatably accommodated in the crankcase 30. A piston 36 is coupled to the crankshaft 34 via a connecting rod 35. The piston 36 is accommodated in the cylinder block 31 so as to be slidable back and forth. A spark plug 37 is disposed on the cylinder head 32. The discharge part of the spark plug 37 faces a combustion chamber into which a mixture of air and fuel is introduced.

  The crankshaft 34 is disposed along the left-right direction of the motorcycle 1. An electric motor 26 is coupled to a right end 34 a that is one end of the crankshaft 34. The electric motor 26 can apply torque to the crankshaft 34. Further, the left end 34 b which is the other end of the crankshaft 34 is coupled to the continuously variable transmission mechanism 21. Further, a generator 27 is coupled to a middle portion of the crankshaft 34 near the left end 34b. The generator 27 generates electric power by the rotation of the crankshaft 34.

  The continuously variable transmission mechanism 21 includes a driving sheave 38, a driven sheave 39, and an endless V-belt 40 wound around the sheave 38, and these are housed in the transmission case 22. The transmission case 22 includes a case main body 23 and a case cover 24 (not shown in FIG. 2) that is detachably attached to the case main body 23. The case body 23 is integrally formed on the left side of the crankcase 30 and extends to the center of the rear wheel 5.

The drive sheave 38 includes a fixed sheave 38a fixed to the left end 34b of the crankshaft 34, and a movable sheave 38b provided closer to the generator 27 than the fixed sheave 38a. A V-belt 40 is accommodated in a V-shaped groove formed between the fixed sheave 38a and the movable sheave 38b.
The fixed sheave 38a is fixed to the crankshaft 34 so that it cannot move in the axial direction of the crankshaft 34 nor can it rotate relative to the crankshaft 34. That is, the relative position with respect to the crankshaft 34 is invariable and rotates together with the crankshaft 34. The movable sheave 38b can be moved in the axial direction of the crankshaft 34, but is attached to the crankshaft 34 so that it cannot rotate relative to the crankshaft 34. More specifically, a key 41 is formed on the outer peripheral surface of the crankshaft 34 along the axial direction. The movable sheave 38b has a boss through which the crankshaft 34 is inserted in the center, and a key groove that engages with the key 41 is formed on the inner peripheral surface of the boss. That is, the movable sheave 38 b is splined to the crankshaft 34.

  The driven sheave 39 includes a fixed sheave 39 a and a movable sheave 39 b, which are mounted on a driven shaft 45 that is pivotally supported at the rear end portion of the transmission case 22. The fixed sheave 39a is provided so that it can rotate relative to the driven shaft 45 but cannot move in the axial direction of the driven shaft 45. The movable sheave 39b is provided so as to rotate together with the fixed sheave 39a and to be movable in the axial direction of the driven shaft 45. More specifically, a boss 43 is formed in the center of the fixed sheave 39a, and a driven shaft 45 is inserted through the boss 43. Further, the boss 43 of the fixed sheave 39a is inserted through the boss formed at the center of the movable sheave 39b. A key (not shown) is formed on the boss 43 of the fixed sheave 39 a along the axial direction of the driven shaft 45. A key groove that engages with the key is formed on the inner peripheral surface of the boss of the movable sheave 39b. That is, the movable sheave 39b is splined to the boss 43 of the fixed sheave 39a. The movable sheave 39b is urged toward the fixed sheave 39a by the compression coil spring 46.

  The rotation of the fixed sheave 39 a is transmitted to the driven shaft 45 via the centrifugal clutch 48. The centrifugal clutch 48 is engaged when the rotational speed of the fixed sheave 39a reaches a predetermined rotational speed, and transmits the rotation of the fixed sheave 39a to the driven shaft 45. The rotation of the driven shaft 45 is decelerated by a speed reduction mechanism including the main shaft 49, transmitted to the drive shaft 50, and transmitted to the rear wheel 5 attached to the drive shaft 50.

Thus, the power of the engine 25 and the electric motor 26 is commonly applied to the crankshaft 34. The power is transmitted to the driven sheave 39 via the driving sheave 38 and the V-belt 40, and further transmitted from the driven sheave 39 to the driving shaft 50 via the centrifugal clutch 48 and the like. ing.
Although illustration is omitted, a centrifugal mechanism is disposed inside the movable sheave 38b (on the side opposite to the fixed sheave 38a). This centrifugal mechanism includes a cam plate and a roller weight. The cam plate is disposed so as to face the movable sheave 38b and has a cam surface that approaches the movable sheave 38b as the distance from the crankshaft 34 increases. The roller weight is disposed between the cam surface of the cam plate and the movable sheave 38b.

As the crankshaft 34 rotates, the roller weight rotates around the crankshaft 34. At this time, the roller weight is moved away from the crankshaft 34 by the centrifugal force, and the interval between the cam plate and the movable sheave 38b is increased. Thereby, the movable sheave 38b moves toward the fixed sheave 38a.
As the movable sheave 38b moves in the axial direction of the crankshaft 34, the width of the V groove formed between the fixed sheave 38a and the movable sheave 38b changes. In accordance with this, the distance from the crankshaft 34 of the V belt 40 changes, and the winding diameter changes. Specifically, the higher the rotation of the crankshaft 34, the closer the movable sheave 38b approaches the fixed sheave 38a, and accordingly, the winding diameter of the V-belt 40 increases.

  The winding diameter of the V belt 40 in the driven sheave 39 also changes according to the change in the winding diameter of the V belt 40 in the driving sheave 38. Specifically, when the winding diameter at the driving sheave 38 is increased, the movable sheave 39 b is displaced away from the fixed sheave 39 a against the spring force of the compression coil spring 46 in the driven sheave 39. On the other hand, when the winding diameter at the driving sheave 38 is reduced, the movable sheave 39 b approaches the fixed sheave 39 a by the spring force of the compression coil spring 46 in the driven sheave 39. In this way, the ratio of the winding diameter of the V-belt 40 between the driving sheave 38 and the driven sheave 39 changes, and the reduction ratio from the crankshaft 34 to the driven shaft 45 changes.

  FIG. 4 is a block diagram for explaining an electrical configuration related to the power unit 3. The power unit 3 includes an engine 25, an electric motor 26, and a generator 27. A power storage unit 55 is coupled to the generator 27. The power storage unit 55 is used as a power source for the electric motor 26. The power storage unit 55 is made up of a battery, a capacitor, and the like, stores power generated by the generator 27, and can supply the stored power to the electric motor 26.

  The operations of the engine 25, the electric motor 26, and the generator 27 are controlled by an electronic control unit (ECU) 60. The electronic control unit 60 includes a computer that operates according to a predetermined program. When the computer operates according to the program, the electronic control unit 60 can operate as a plurality of function processing units. Specifically, the electronic control unit 60 realizes functions as a rotation speed detection unit 61, an ignition timing detection unit 62, a crank angle detection unit 63, a misfire determination unit 64, and a power control unit 65. Furthermore, the function of the power control unit 65 includes a function as a power generation load control unit 66 and a function as an electric motor control unit 67.

  The function of the rotational speed detection unit 61 is to calculate the rotational speed of the crankshaft 34 from the output signal of the crank angle sensor 57. The crank angle sensor 57 is attached to the engine 25 and outputs a signal representing the crank angle of the crankshaft 34 (the rotation angle of the crankshaft 34). The function of the ignition timing detection unit 62 is to detect the operation timing of the spark plug 37, that is, the timing at which the air-fuel mixture in the combustion chamber of the engine 25 is ignited. The function of the crank angle detection unit 63 is to calculate the crank angle based on the output signal of the crank angle sensor 57. Based on the calculated crank angle, the ignition timing detection unit 62 detects the ignition timing. The function of the misfire determination unit 64 is to determine whether combustion has occurred or combustion has failed (whether it has misfired) from the change in rotational speed immediately after the ignition timing.

  The function of the power generation load control unit 66 is to control the power generation load (load torque applied to the crankshaft 34) by the power generator 27. More specifically, the power generation load control unit 66 controls the power generation load by the generator 27 according to the stroke and the rotation speed of the engine 25. The power generation load can be controlled by controlling the amount and phase of the field current, for example.

The function of the electric motor control unit 67 is to control the torque generated by the electric motor 26. More specifically, the electric motor control unit 67 controls the torque generated by the electric motor 26 according to the stroke and the rotational speed of the engine 25.
FIG. 5 is a diagram showing an example of the relationship between the rotational speed and engine average torque in a single cylinder engine. The combustion cycle of a four-cycle engine includes an intake stroke, a compression stroke, a combustion stroke (expansion stroke), and an exhaust stroke. The engine average torque is an average value of instantaneous torque generated by the engine 25 in the combustion stroke, the exhaust stroke, the intake stroke, and the compression stroke.

The engine average torque depends on the rotational speed of the engine 25. Specifically, the engine average torque shows a mountain-shaped change with respect to the rotational speed, and takes a maximum value at a predetermined rotational speed (for example, 5000 rpm). The maximum value of the engine average torque is, for example, about 20 Nm.
FIG. 6 is a diagram showing an example of fluctuations in rotational speed during a combustion cycle of a single cylinder four-cycle engine. Ignition of the air-fuel mixture in the combustion chamber is performed at the end of the compression stroke. Thereby, the rotational speed of the engine 25 is rapidly accelerated in the subsequent combustion stroke, and decelerated from the exhaust stroke to the compression stroke. The instantaneous acceleration torque in the combustion stroke is, for example, about 200 Nm.

  The continuously variable transmission mechanism 21 needs to be designed to have sufficient durability in consideration of the average torque and the instantaneous torque output to the crankshaft 34. More specifically, when designing the strength of the key 41 provided on the crankshaft 34 and the key provided on the driven sheave 39, the average torque and instantaneous acceleration torque output to the crankshaft 34 are calculated. It is necessary to consider. Therefore, if the output torque of the engine 25 appears on the crankshaft 34 as it is, the strength of the continuously variable transmission mechanism 21 is considered so as to have sufficient durability in consideration of the engine average torque and the instantaneous acceleration torque. Design needs to be made.

  FIG. 7A shows fluctuations in the engine instantaneous torque and engine average torque generated by the engine 25. The engine instantaneous torque rises sharply during the combustion stroke and decreases during the subsequent exhaust stroke, intake stroke, and compression stroke. More specifically, in the combustion stroke, an engine instantaneous torque larger than the engine average torque is generated. However, the engine instantaneous torque in the exhaust stroke, the intake stroke, and the compression stroke is lower than the engine average torque and has a negative period. Exists. In particular, the instantaneous engine torque at the end of the compression stroke has a relatively large negative value. In the combustion stroke, the engine instantaneous torque rises steeply in the initial stage. Then, the engine instantaneous torque tends to decrease after reaching a peak (maximum point) in the first half of the combustion stroke, and becomes zero at the end of the combustion stroke.

  FIG. 7B is a diagram for explaining the power generation load that varies due to the control by the power generation load control unit 66. The load torque (power generation load) applied to the crankshaft 34 by the generator 27 is a torque in a direction that prevents the engine 25 from rotating, that is, a negative value. This power generation load is controlled to a relatively large negative value in the combustion stroke in which the engine instantaneous torque increases. The power generation load in the subsequent exhaust stroke, intake stroke, and compression stroke is controlled to zero. More specifically, the fluctuation of the power generation load in the combustion stroke follows the characteristics obtained by reversing the fluctuation of the engine instantaneous torque. However, the power generation load is controlled so as to cancel the engine instantaneous torque at a certain ratio (for example, 50%) instead of canceling all the engine instantaneous torque by the power generation load. As a result, in the combustion stroke, it is possible to apply drive torque to the crankshaft 34 while relaxing the instantaneous engine torque. Then, electric power corresponding to the power generation load is generated from the power generator 27 and accumulated in the power storage unit 55.

  FIG. 7 (c) is a diagram showing the generated torque (motor torque) of the electric motor 26 that varies under the control of the electric motor control unit 67. The motor torque is controlled so as to compensate for the shortage during a period when the engine instantaneous torque is lower than the engine average torque, that is, during a period when the engine instantaneous torque is insufficient. Specifically, the motor torque is maintained at zero until the end of the combustion stroke. Then, the motor torque is controlled so as to fluctuate with a value larger than zero from the end of the combustion stroke. More specifically, motor torque fluctuations are controlled to compensate for the difference between the engine instantaneous torque and the engine average torque. In particular, in the exhaust stroke, the intake stroke, and the compression stroke, the engine instantaneous torque has a negative value, so that a motor torque larger than the engine average torque is generated from the electric motor 26.

  FIG. 7 (d) is a diagram illustrating a combined torque obtained by combining the instantaneous torque, the power generation load, and the motor torque of the engine 25. Excessive engine instantaneous torque mainly in the combustion stroke is suppressed by the power generation load. The motor torque mainly compensates for torque shortage in the exhaust stroke, the intake stroke, and the compression stroke. As a result, the overall combined torque gradually decreases toward the exhaust stroke after rising at the beginning of the combustion stroke, and thereafter becomes a value approximate to the average torque until the next combustion stroke.

In this way, fluctuations in the engine instantaneous torque are suppressed by the power generation load and the motor torque. In particular, even if the engine 25 is a single cylinder engine, a smooth torque output similar to that of a multi-cylinder engine is realized. As a result, vibrations can be suppressed and the motorcycle 1 can run smoothly, so that comfort can be improved and quietness can be improved.
FIG. 8 is a flowchart for explaining the operation of the electronic control unit 60, and shows a process that is repeatedly executed every predetermined control period (for example, 1/100 second). The electronic control unit 60 determines whether or not the engine 25 is in operation by checking the rotational speed of the crankshaft 34 (step S1). More specifically, the rotational speed of the crankshaft 34 is obtained by processing the output signal of the crank angle sensor 57 (function of the rotational speed detection unit 61). If the rotational speed is equal to or higher than a predetermined threshold, it is determined that the engine 25 is operating, and if the rotational speed is lower than the threshold, it is determined that the engine 25 is stopped. If the engine 25 is stopped (step S1: NO), the subsequent processing is not performed.

  When the engine 25 is in operation (step S1: YES), top dead center timing and ignition timing are detected (step S2: function of the ignition timing detection unit 62). That is, the crank angle is obtained based on the output signal of the crank angle sensor 57 (function of the crank angle detection unit 63), the time when the piston 36 reaches the top dead center is detected from the crank angle, and further, the spark plug 37 The ignition timing due to is detected.

  When the ignition timing is detected, the electronic control unit 60 next detects a change in the rotational speed of the engine 25 (a change from the previous control period) (step S3). Then, based on the detected fluctuation in the rotational speed, it is determined whether the engine 25 is burning or misfiring (step S4: function of the misfire determination unit 64). If the fluctuation of the rotational speed is a value comparable to the instantaneous rotational speed increase after ignition, the power generation load is calculated according to the rotational speed (step S5: function of the power generation load control unit 66). Based on the calculated power generation load, the power generation load of the generator 27 is controlled (step S6: function of the power generation load control unit 66). Thereby, the excessive instantaneous torque which the engine 25 generate | occur | produces mainly in a combustion stroke is suppressed.

  Further, the electronic control unit 60 calculates the motor torque (assist amount) to be applied to the crankshaft 34 in accordance with the rotational speed of the engine 25 (step S7: function of the electric motor control unit 67). The electric motor 26 is driven so that the calculated motor torque is generated (step S8: function of the electric motor control unit 67). As a result, the shortage of the instantaneous engine torque in the exhaust stroke, the intake stroke, and the compression stroke is mainly compensated.

If it is determined in step S4 that the engine 25 has misfired, the processing in steps S5 and S6 (that is, control of the power generation load) is omitted, and only the assist control (steps S7 and S8) by the electric motor 26 is performed. Executed.
The transition time from generation of the power generation load to generation of motor torque may be determined according to the rotational speed of the engine 25, for example. Specifically, the rotational speed may be divided into a plurality of regions, and the transition time may be determined in advance for each region and patterned.

  FIG. 9 is a characteristic diagram for explaining an example of setting the power generation load with respect to the engine speed (step S5 in FIG. 8). As described with reference to FIG. 5 described above, the engine average torque shows a mountain-shaped change so as to have a maximum point at a predetermined rotational speed (for example, 5000 rpm). Therefore, in the example of FIG. 9, the power generation load is set so as to show the change in the mountain shape according to the rotation speed so as to correspond to the fluctuation of the engine average torque. By storing such setting values as a map, an appropriate power generation load corresponding to the engine rotation speed can be set without requiring a complicated calculation.

  FIG. 10 is a characteristic diagram for explaining a setting example (step S7 in FIG. 8) of the motor torque with respect to the engine rotation speed. As described with reference to FIG. 5 described above, the engine average torque shows a mountain-shaped change so as to have a maximum point at a predetermined rotational speed (for example, 5000 rpm). Therefore, in the example of FIG. 10, the motor torque is set so as to show a change in the chevron according to the rotational speed so as to correspond to the fluctuation of the engine average torque. By storing such setting values as a map, an appropriate motor torque corresponding to the engine rotation speed can be set without requiring complicated calculations.

As shown in FIG. 10, it is preferable to select one of the power mode, the normal mode, and the charging mode so that the electric motor 26 can be controlled.
The power mode is an operation mode in which the energy (discharge energy) generated by the electric motor 26 is larger than the energy (power generation energy) stored in the power storage unit 55 by the generator 27. This power mode is preferably automatically selected by the electronic control unit 60 when the rider performs an accelerator operation for rapid acceleration. As a result, the torque generated by the engine 25 can be supplemented by the torque generated by the electric motor 26, so that acceleration according to the rider's operation intention becomes possible.

The normal mode is an operation mode in which the energy accumulated in the power storage unit 55 by the generator 27 and the energy generated by the electric motor 26 are substantially equal. It is preferable that the normal mode is automatically selected by the electronic control unit 60 during constant speed traveling or normal acceleration.
The charging mode is an operation mode in which the energy generated by the electric motor 26 is less than the energy stored in the power storage unit 55 by the generator 27. It is preferable that the charging mode is automatically selected by the electronic control unit 60 during deceleration, idling, and when the stored power of the power storage unit 55 is low.

Thus, by appropriately selecting the operation mode of the electric motor 26, the motorcycle 1 can be driven according to the rider's intention to operate. At the same time, the energy generated by the generator 27 and accumulated in the power storage unit 55 can be appropriately used by the electric motor 26.
As described above, according to this embodiment, in the combustion stroke in which the instantaneous torque of the engine 25 increases, power is generated by the generator 27 and electric power is accumulated in the power storage unit 55. In the exhaust stroke, the intake stroke, and the compression stroke in which the instantaneous torque of the engine 25 is reduced, the electric motor 26 is driven using the electric power stored in the power storage unit 55 to compensate for the insufficient torque. Thus, the torque output to the crankshaft 34 is smoothed by dispersing the energy generated by the engine 25 in the combustion cycle. Thereby, torque fluctuation can be suppressed without impairing energy efficiency. As a result, vibration generated in the motorcycle 1 can be suppressed and quietness can be improved. This effect can be obtained not only when starting the engine 25 but also during steady operation after starting, and does not depend on the rotational speed.

Furthermore, since the torque output to the crankshaft 34 is smoothed, the strength design of the continuously variable transmission mechanism 21 can be made gradual, and the cost can be reduced accordingly.
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form. For example, in the above-described embodiment, an example in which the present invention is applied to a single cylinder engine has been described. However, the present invention may also be applied to a multi-cylinder engine to suppress torque fluctuation. In the above-described embodiment, a motorcycle is taken as an example of a vehicle. However, the present invention can also be applied to other forms of vehicles such as a four-wheel vehicle. In the above-described embodiment, the example in which the operation mode of the electric motor 26 is automatically selected by the electronic control unit 60 has been described. However, the operation mode may be manually switched by an operation switch. In addition, various design changes can be made within the scope of matters described in the claims.

The characteristics to be understood from the description of this specification are described below.
1. A drive shaft that supports the wheels, an engine, a generator that generates power using the power of the engine, a power storage unit that stores power generated by the power generator, and an electric motor that generates power using power stored in the power storage unit A motor, a transmission mechanism that transmits the power of the engine and the electric motor to a drive shaft, and a power control unit that controls a power generation load of the generator and a generated torque of the electric motor so as to compensate for power fluctuations of the engine Including the vehicle.

  According to this configuration, electric power is stored in the power storage unit by driving the generator with the power of the engine. The electric motor is driven by the electric power stored in the power storage unit. The power of the engine and the electric motor is transmitted to the drive shaft by the transmission mechanism. Thus, a hybrid type vehicle is configured. The generator load of the generator and the generated torque of the electric motor (hereinafter referred to as “motor torque”) are controlled so as to compensate for engine power fluctuations. Thereby, the vibration resulting from the engine power fluctuation can be suppressed, and the comfort of the passenger and the quietness of the vehicle can be enhanced. Of course, not only when the engine is started, but also in a steady operation state after starting, control of the power generation load and motor torque can compensate for engine power fluctuations and suppress vehicle vibration.

More specifically, during periods when the engine power is excessive, it is preferable to increase the power generation load and suppress the motor torque. Further, it is preferable to reduce the power generation load and increase the motor torque during a period when the engine power is insufficient. As a result, power is generated using the excessive power of the engine, and the electric power accumulated in the power storage unit by this power generation can be used for driving the electric motor in a period where the power of the engine is insufficient. In this way, vibration due to engine power fluctuation can be suppressed while improving energy efficiency.
2. The engine is a four-cycle engine that cyclically executes an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke, and the power control unit is configured to generate the engine by a power generation load of the generator in at least a part of the combustion stroke. The vehicle according to claim 1, further comprising a power generation load control unit that suppresses the power of

The engine generates a large amount of power during the combustion stroke and decreases during the other strokes. Therefore, the power of the engine can be suppressed by increasing the power generation load in at least a part of the combustion stroke. As a result, power fluctuation can be suppressed while power generation is performed using excess power in the combustion cycle. Thereby, vibration can be suppressed while improving energy efficiency. In addition, since fluctuations in power during the combustion cycle can be suppressed, fluctuations in power of the engine can be suppressed not only when the engine is started, but also in a steady operation state after the start.
3. The vehicle according to claim 2, wherein the power control unit includes an electric motor control unit that generates torque from the electric motor in the intake stroke, the compression stroke, and the exhaust stroke.

In the intake stroke, the compression stroke, and the exhaust stroke, the power generated by the engine is small. Therefore, in these processes, fluctuations in engine power can be suppressed by generating torque from the electric motor. That is, excessive power of the engine is suppressed by increasing the power generation load in at least a part of the combustion stroke, while the motor torque is compensated for the engine power shortage in the intake stroke, the compression stroke, and the exhaust stroke. . As a result, power fluctuations during the combustion cycle can be further suppressed, and vibration can be further suppressed. In addition, since the electric power generated using the excessive power of the combustion stroke can be used for driving the electric motor in the intake stroke, the compression stroke, and the exhaust stroke, energy efficiency can be increased and environmental performance can be improved. Of course, since power fluctuations during the combustion cycle can be suppressed, power fluctuations not only during engine startup but also during steady engine operation can be suppressed. Thereby, a passenger | crew's comfort and the quietness of a vehicle can be improved further.
4). The rotation speed detection unit for detecting the rotation speed of the engine, and the power generation load control unit variably sets the power generation load according to the rotation speed detected by the rotation speed detection unit. Or the vehicle according to item 3.

According to this configuration, the power generation load is variably set according to the rotational speed of the engine, whereby the power fluctuation of the engine can be further effectively suppressed.
5). The vehicle according to any one of Items 1 to 4, wherein the engine is a single cylinder engine.
In the case of a single cylinder engine, the power fluctuation during the combustion cycle is large. Therefore, by applying the feature such as the item 1 or the like, the power fluctuation can be effectively suppressed, so that the vibration can be remarkably reduced. Thereby, in a hybrid type vehicle using a single cylinder engine, it is possible to improve passenger comfort and quietness of the vehicle.
6). The electric motor control unit may variably set the generated torque of the electric motor in accordance with the rotation speed detected by the rotation speed detection unit. Thereby, the vibration resulting from the motive power fluctuation | variation of an engine can be suppressed much more effectively. Further, when the engine power shortage occurs with the increase in the rotational speed, the power shortage can be compensated by an appropriate motor torque corresponding to the rotational speed.
7). The power control unit may further include a misfire determination unit that performs a misfire determination based on a rotation speed fluctuation after ignition. In this case, it is preferable that the power generation load control unit sets the power generation load to zero when it is determined by the misfire determination unit that a misfire has occurred. When a misfire occurs, excessive power is not generated in the combustion stroke, so that the engine rotation can be promoted by setting the power generation load to zero.

1 is a side view for explaining a configuration of a motorcycle that is a vehicle according to an embodiment of the present invention. FIG. It is an enlarged side view of a power unit. It is a top view which shows the partial cross section of a power unit. It is a block diagram for demonstrating the electric constitution regarding a power unit. It is a figure which shows an example of the relationship between the rotational speed and engine average torque in a single cylinder engine. It is a figure which shows an example of the fluctuation | variation of the rotational speed in the combustion cycle of a single cylinder 4 cycle engine. (a) shows the fluctuations of the engine instantaneous torque and the engine average torque. (b) shows the fluctuation of the power generation load. (c) shows the fluctuation of the motor torque. (d) shows the combined torque obtained by combining the engine instantaneous torque, the power generation load, and the motor torque. It is a flowchart for demonstrating operation | movement of an electronic control unit. It is a characteristic view for demonstrating the example of a setting of the electric power generation load with respect to an engine speed. It is a characteristic view for demonstrating the example of a setting of the motor torque with respect to an engine speed.

Explanation of symbols

1 motorcycle 3 power unit 4 front wheel 5 rear wheel (wheel supported by drive shaft)
20 Hybrid prime mover unit 21 Continuously variable transmission mechanism (transmission mechanism)
25 Engine 26 Electric motor 27 Generator 34 Crankshaft 36 Piston 38 Drive side sheave (transmission mechanism)
39 Driven sheave (transmission mechanism)
40 V belt (transmission mechanism)
48 Centrifugal clutch (transmission mechanism)
DESCRIPTION OF SYMBOLS 50 Drive shaft 55 Power storage unit 60 Electronic control unit 61 Rotational speed detection unit 62 Ignition timing detection unit 63 Crank angle detection unit 64 Misfire determination unit 65 Power control unit 66 Power generation load control unit 67 Electric motor control unit

Claims (5)

A drive shaft that supports the wheels;
Engine,
A generator for generating electric power by the engine;
A power storage unit for storing the power generated by the generator;
An electric motor that generates power by the electric power stored in the power storage unit;
A transmission mechanism for transmitting the power of the engine and the electric motor to a drive shaft;
A vehicle comprising: a power control unit that controls a power generation load of the generator and a torque generated by the electric motor so as to compensate for power fluctuations of the engine. The engine is a four-cycle engine that cyclically executes an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke,
The vehicle according to claim 1, wherein the power control unit includes a power generation load control unit that suppresses power of the engine by a power generation load of the generator during at least a part of the combustion stroke.   The vehicle according to claim 2, wherein the power control unit includes an electric motor control unit that generates torque from the electric motor in the intake stroke, the compression stroke, and the exhaust stroke. A rotation speed detection unit for detecting the rotation speed of the engine;
The vehicle according to claim 2, wherein the power generation load control unit variably sets a power generation load in accordance with a rotational speed detected by the rotational speed detection unit.   The vehicle according to any one of claims 1 to 4, wherein the engine is a single cylinder engine.

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