JP7235897B2 - straddled vehicle - Google Patents

Description

The present invention relates to a straddle-type vehicle.

For example, Patent Literature 1 discloses a straddle-type vehicle. The straddle-type vehicle of Patent Document 1 is a hybrid vehicle. The straddle-type vehicle of Patent Document 1 includes an engine, an ACG starter (alternating current generator starter), a first battery, and a second battery.
ACG starters are permanent magnet generators. The ACG starter is provided at one end of the crankshaft of the engine. The engine is started by driving the ACG starter. The first battery is a 48V battery that supplies power to the ACG starter. The second battery is a low-voltage 12V battery that supplies power to a plurality of auxiliary devices. The ACG starter functions as a generator. A first battery is charged. In addition, electric charge resulting from the voltage of the first battery is accumulated in the capacitor. This charge is charged to the second battery via the converter.
The first battery of the straddle-type vehicle disclosed in Patent Document 1 starts the engine by supplying electric power to the ACG starter. When the remaining capacity of the first battery is less than the set value, the power supplied from the second battery drives the ACG starter.

WO2018/180650

A straddle-type vehicle is configured such that the posture of the vehicle is controlled by shifting the weight of the driver during running. Therefore, from the viewpoint of operability and running performance, straddle-type vehicles are required to have a compact body.
Straddle-type vehicles are required to have a compact body while suppressing deterioration in engine starting performance.
For example, as shown in Patent Document 1, an ACG starter for a straddle-type vehicle is connected to a crankshaft without a reduction gear such as a gear or belt pulley. Therefore, the structure of the unit including the engine and the ACG starter is simple, and the body of the straddle-type vehicle is made compact.

The ACG starter, which is provided on the crankshaft without a speed reducer, outputs a large amount of torque when driving the crankshaft with engine starting performance, compared to when it is connected to the crankshaft via a speed reducer. Desired.
Straddle-type vehicles are required to have a compact vehicle body while suppressing deterioration in engine start-up or assist performance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a straddle-type vehicle capable of reducing the size of the vehicle body while suppressing deterioration in engine start-up or assist performance by a permanent magnet generator provided on a crankshaft without a speed reducer.

According to the straddle-type vehicle disclosed in Patent Document 1, for example, the first battery outputs 48V to start the engine. When the remaining capacity of the first battery is less than the set value, the power source is switched from the first battery to the second 12V battery. The first battery that outputs 48V for starting the engine contains more cells than a 12V battery and is generally larger than a battery that outputs 12V. As a result, the saddle-ride type vehicle as shown in Patent Document 1 is rather large in spite of having an ACG starter connected to the crankshaft without a reduction gear. In other words, the vehicle body cannot be made compact.

The inventor of the present invention has devised a method for effectively utilizing two types of power storage units.
In addition to the first power storage unit that has a maximum rated voltage of 12 V or more and stores electric power, the inventors studied a second power storage unit that is always connected in series with the first power storage unit. The second power storage unit was set to have a maximum charge rate higher than the maximum charge rate of the first power storage unit. The inventor further added a current maintaining circuit that maintains a state in which a charging current flows to the first power storage unit that causes a voltage drop so that the voltage applied to the second power storage unit does not exceed the upper limit voltage of the second power storage unit. investigated.
As a result, while the first power storage unit is being charged, the first power storage unit is not electrically disconnected and the voltage applied to the second power storage unit does not exceed the upper limit voltage set for the second power storage unit. A state in which the charging current flows to the power storage unit can be maintained.

Further, Japanese National Publication of International Patent Application No. 2014-510657 discloses a first voltage supply unit and a power storage unit provided in an automobile. According to this publication, since the power storage unit is disconnected depending on the state of the switch, the maximum voltage for power generation may be directly applied to the first voltage supply unit. Automobiles such as those shown in Japanese National Publication of International Patent Application No. 2014-510657 are generally equipped with an alternator whose output can be adjusted with a field current.
On the other hand, a saddle-ride type vehicle is equipped with a permanent magnet type motor generator, so that the installed power generating means can be made compact. However, unlike an alternator, a permanent magnet motor generator cannot adjust the power generated by the field current.
However, by configuring the current maintaining circuit to cause a voltage drop without electrically disconnecting the second power storage unit, the remaining voltage applied to the first power storage unit is suitable for charging the first power storage unit. can be suppressed.

The power storage device includes a first power storage unit and a second power storage unit having a maximum rated voltage of 12 V or higher, and the first power storage unit and the second power storage unit are always connected in series, so that when the power storage device discharges , can output voltages greater than 12V. As a result, the permanent magnet motor generator and the inverter can be driven with a voltage higher than 12V when the engine is started or assisted. A combination of the second power storage units makes it easy to output a voltage higher than 12V.
Moreover, by adjusting the type and configuration of the second power storage unit combined with the first power storage unit and the voltage of the current maintaining circuit, the voltage when the power storage device discharges can be adjusted according to the capabilities and requirements of the permanent magnet motor generator. The output can be easily adapted. That is, it is possible to easily set a voltage higher than the voltage of the first power storage unit as the output voltage of the power storage device.

The maximum charging rate of the second power storage unit is set to be greater than twice the maximum charging rate of the first power storage unit. Therefore, when the current flowing through the second power storage unit during charging of the power storage device also flows through the first power storage unit, the charging rate of the second power storage unit to full charge tends to be higher than the charging rate of the first power storage unit. That is, for example, the second power storage unit is charged in a shorter period than the first power storage unit. Therefore, the power storage device can output a voltage higher than 12 V even while the power storage device is being charged after being discharged, and can recover to a state in which a large voltage can be output in a short time after the start of charging.

Therefore, the permanent magnet type motor generator can be driven with a voltage higher than 12V when the engine is started or assisted.

For example, the first voltage supply unit and the power storage unit in JP-A-2014-510657 are connected in series. The voltages from both the first voltage supply unit and the power storage unit connected in series are supplied to electrical equipment that requires stabilization of the applied voltage. When the engine is started or assisted, the first electric machine, which is the starting motor, is supplied with electric power only from the first voltage supply unit, out of the first voltage supply unit and the storage unit. The first voltage supply unit is a 12V battery. This limits the maximum voltage supplied to the starter motor to 12V.

On the other hand, when the starting motor is supplied with electric power from the first power storage unit and the second power storage unit connected in series, the starting motor can output a large torque as compared with the case of 12 V or less. Also, the starter motor can drive the crankshaft to higher rotational speeds. Therefore, the starting performance or assist performance of the straddle-type vehicle can be improved.

The power storage device can output a voltage higher than 12V due to the combination of the first power storage unit and the second power storage unit. Therefore, neither the first power storage unit nor the second power storage unit need to independently output a voltage higher than 12V. Therefore, in a configuration for driving a permanent magnet type motor generator with a voltage higher than 12 V, for example, in the case where at least one of the first power storage unit and the second power storage unit is compatible with a voltage higher than 12 V as in Patent Document 1, In comparison, the volume of the power storage device can be reduced.

Moreover, the voltage between the power storage device and the permanent magnet motor generator is higher than 12 V both when the power storage device is discharged and when the power storage device is charged. Therefore, when transmitting electric power, the current flowing between the power storage device and the permanent magnet motor generator can be reduced. Therefore, loss due to current can be reduced. Also, as described above, the second power storage unit is charged in a shorter period than the first power storage unit. Also, since the first power storage unit is a battery, the amount of voltage drop due to discharge is smaller than that of the second power storage unit. That is, the voltage drop of the first power storage unit due to discharge is suppressed. Therefore, the power storage device can output a large voltage obtained by adding the voltage of the second power storage unit to the voltage of the first power storage unit in a short time after the start of charging from the discharged state of the power storage device.

Since the power storage device can output a large voltage, the wiring distance between the power storage device and the inverter permanent magnet motor generator can be set long for a certain allowable range of loss. As a result, the degree of freedom in layout of the power storage device and the inverter in the vehicle body is increased, so that the arrangement positions of the power storage device and the inverter can be adjusted so as to reduce the waste of space that occurs when the power storage device and the inverter are arranged. Therefore, the vehicle body can be made compact.

The straddle-type vehicle according to each aspect of the present invention completed based on the above knowledge has the following configuration.

(1) A straddle-type vehicle,
The straddle-type vehicle
wheels and
an engine having a crankshaft for outputting torque from the crankshaft for driving the wheels generated by combustion operation;
a permanent magnet motor generator provided at one end of the crankshaft, having a permanent magnet, starting or assisting the engine by rotating the crankshaft, and generating power by being driven by the engine;
a first power storage unit that is a battery that has a maximum rated voltage of 12 V or more and stores electric power;
a second power storage unit always connected in series with the first power storage unit with respect to the permanent magnet motor generator and having a maximum charge rate higher than twice the maximum charge rate of the first power storage unit;
a plurality of switching units that are electrically connected to the second power storage unit always connected in series with the first power storage unit and the permanent magnet motor-generator, and that control current output from the permanent magnet motor-generator; an inverter equipped with
When the engine is started or assisted, the permanent magnet type power storage unit is provided at one end of the crankshaft from the first power storage unit and the second power storage unit that are connected in series via the inverter without a speed reducer. While causing the motor generator to output a current and generating power from the permanent magnet type motor generator, the inverter charges at least the first power storage unit without electrically disconnecting the second power storage unit. a current maintaining circuit that maintains a state in which a charging current flows to the first power storage unit so that the voltage applied to the second power storage unit does not exceed an upper limit voltage set for the second power storage unit;
Prepare.

In the straddle-type vehicle having the above configuration, the first power storage unit and the second power storage unit having a maximum rated voltage of 12 V or more are always connected in series, so that when the power storage device discharges, a voltage higher than 12 V is output. can do. Note that the power storage device includes a first power storage unit and a second power storage unit. As a result, the permanent magnet motor generator and the inverter can be driven with a voltage higher than 12V when the engine is started or assisted. A combination of the second power storage units makes it easy to output a voltage higher than 12V.
Moreover, by adjusting the type and configuration of the second power storage unit combined with the first power storage unit, the voltage when the power storage device discharges can be easily adapted to the capacity and required output of the permanent magnet motor generator. can.
The maximum charging rate of the second power storage unit is set to be greater than twice the maximum charging rate of the first power storage unit. Therefore, when the current flowing through the second power storage unit during charging of the power storage device also flows through the first power storage unit connected in series with the second power storage unit, the charging rate for full charge of the second power storage unit is It tends to be higher than the charging rate in one power storage unit. That is, for example, the second power storage unit is charged in a shorter period than the first power storage unit. For this reason, even when the power storage device is once discharged and then discharged while being charged, the power storage device can output a voltage higher than 12V.
The state of charge of the second power storage unit changes in a shorter period than that of the first power storage unit. The current maintenance circuit causes a voltage drop so that the second power storage unit does not exceed the upper limit voltage of the second power storage unit. In the straddle-type vehicle having the above configuration, the current maintaining circuit maintains the state in which the charging current flows to the first power storage unit so that the second power storage unit does not exceed the upper limit voltage of the second power storage unit. Therefore, for example, the charging state of the first power storage unit can be continued even after the charging of the second power storage unit is finished.

In addition, in the straddle-type vehicle having the above configuration, the permanent magnet motor generator can be driven at a voltage higher than 12 V when the engine is started or assisted. can output large torque. Also, a permanent magnet motor-generator can drive the crankshaft to higher rotational speeds. Therefore, deterioration in performance can be suppressed in a straddle-type vehicle having a permanent magnet generator provided at one end of the crankshaft.

The power storage device can output a voltage higher than 12V due to the combination of the first power storage unit and the second power storage unit. Therefore, neither the first power storage unit nor the second power storage unit needs to output a voltage higher than 12V. Therefore, in a configuration for driving a permanent magnet type motor generator with a voltage higher than 12 V, for example, in the case where at least one of the first power storage unit and the second power storage unit is compatible with a voltage higher than 12 V as in Patent Document 1, In comparison, the volume of the power storage device can be reduced.

Moreover, the voltage between the power storage device and the permanent magnet motor generator is higher than 12 V both when the power storage device is discharged and when the power storage device is charged. Therefore, when transmitting electric power, it is possible to reduce the current flowing between the power storage device and the permanent magnet motor generator. Therefore, loss due to current can be reduced. Therefore, the wiring distance between the power storage device and the inverter permanent magnet motor generator can be increased for a certain allowable range of loss. As a result, the degree of freedom in layout of the power storage device and the inverter in the vehicle body is increased, so that the arrangement positions of the power storage device and the inverter can be adjusted so as to reduce the waste of space that occurs when the power storage device and the inverter are arranged. Therefore, the vehicle body can be made compact.
Thus, according to the straddle-type vehicle having the above configuration, the straddle-type vehicle having the permanent magnet generator provided at one end of the crankshaft can be made compact while suppressing deterioration in engine starting or assist performance. can be

(2) In the straddle-type vehicle of (1), the upper limit voltage of the second power storage unit is lower than the maximum rated voltage of the first power storage unit.

According to the straddle-type vehicle having the above configuration, when the power storage device is charged, the second power storage unit is likely to be charged in a shorter period than the first power storage unit. Therefore, the second power storage unit is charged in a charging period shorter than the charging period of the first power storage unit that outputs a voltage of 12V or higher. Therefore, it is possible to utilize the second power storage unit even after a short charging period.

(3) The straddle-type vehicle of (1) or (2),
While the inverter charges at least the first power storage unit, a second voltage, which is the voltage applied to the second power storage unit, is lower than the first voltage applied to the first power storage unit.

According to the straddle-type vehicle having the above configuration, the second voltage is lower than the first voltage. Therefore, the voltage of the power storage device can be adjusted without changing the type of the electric auxiliary machine that receives voltage from the power storage device and the inverter.

(4) A straddle-type vehicle according to any one of (1) to (3),
The straddle-type vehicle includes a capacitor connected in parallel with the first power storage unit, which is a battery.

In the first power storage unit of the straddle-type vehicle having the above configuration, even when the charge capacity is reduced due to deterioration, for example, the maximum rated voltage is prevented from decreasing, so that the capacitor can be charged at the maximum rated voltage. Therefore, when the engine is started or assisted, electric power can be output to the permanent magnet type motor-generator together with the charge charged in the capacitor.

(5) A straddle-type vehicle according to any one of (1) to (4),
A permanent magnet type motor generator includes a rotor having a plurality of magnetic pole portions made up of the permanent magnets;
a stator core having a plurality of slots spaced apart in the circumferential direction of the permanent magnet motor generator and a stator having windings passing through the slots;
The number of the magnetic pole portions is greater than the number of the plurality of teeth.

According to the straddle-type vehicle having the above configuration, the angular velocity relative to the rotation speed of the rotor is greater than in the case where the number of magnetic pole portions is smaller than the number of teeth.
The angular velocity is an angular velocity with respect to an electrical angle based on the repetition period of the magnetic poles. The higher the angular velocity, the higher the inductance of the winding. Also, the angular velocity further increases as the rotational speed of the rotor increases. The inductance of the windings impedes the flow of current through the windings. Therefore, although the induced electromotive voltage increases as the rotational speed of the rotor increases, the excessive increase in current output from the generator is suppressed by the large inductance of the winding.
Therefore, according to the straddle-type vehicle having the above configuration, the power storage device can be charged up to a higher rotation speed of the crankshaft than when the number of magnetic pole portions is smaller than the number of teeth. Therefore, wasteful consumption of electric power can be suppressed.

(6) A straddle-type vehicle according to any one of (1) to (4),
A permanent magnet generator has a plurality of magnetic pole portions made up of the permanent magnets, and is connected to one end of a crankshaft without a reduction gear.
a stator having a stator core in which a plurality of slots are spaced in the circumferential direction of the permanent magnet generator and a stator winding provided to pass through the slots;
a plurality of detected parts provided on the rotor at intervals in the circumferential direction;
a rotor position detection device having detection windings provided at positions facing the plurality of detected portions and provided separately from the stator windings;
Prepare.

(7) A straddle-type vehicle according to any one of (1) to (6),
The engine further comprises a crankcase configured to be internally lubricated with oil,
The permanent magnet type motor generator is provided at a position in contact with the oil.

According to the straddle-type vehicle having the above configuration, the power storage device can be charged within a range up to a high rotational speed of the crankshaft without wasting electric power. Therefore, in such a permanent magnet motor-generator, the temperature of the stator winding does not or hardly becomes higher than the temperature of the oil. Evaporation can be suppressed.
For example, when the permanent magnet motor generator is placed in an environment where it contacts oil, it is usually required to increase the size of the cooling mechanism. However, according to the straddle-type vehicle configured as described above, it is possible to suppress or avoid an increase in the size of the cooling mechanism. Therefore, the vehicle body can be made more compact.

(8) A straddle-type vehicle according to any one of (1) to (7),
The inverter supplies electric power from the first power storage unit and the second power storage unit to the permanent magnet motor generator while the straddle-type vehicle is running, and assists the permanent magnet motor generator in rotating the crankshaft. .

According to the straddle-type vehicle configured as described above, the permanent magnet motor generator can be driven at a voltage higher than 12V while the straddle-type vehicle is running. Therefore, the crankshaft can be driven to a higher rotational speed than when driven at 12V, for example. Therefore, acceleration by the engine can be assisted up to higher rotational speeds than when driving at 12V, for example. Furthermore, the vehicle body can be made more compact than when a power storage device other than, for example, a 12V power storage device is provided.

The first power storage unit is, for example, a battery. The first power storage unit is, for example, a lead battery. However, the first power storage unit is not particularly limited, and may be, for example, a lithium ion battery.

The second power storage unit is, for example, a capacitor. The second power storage unit is, for example, a lithium ion capacitor. However, the second power storage unit is not particularly limited, and may be, for example, an electric double layer capacitor or an electrolytic capacitor. Also, the second power storage unit may be, for example, a battery. The second power storage unit may be, for example, a lithium-ion battery (for example, SCiB (registered trademark)) using a carbon material for the negative electrode, or a nickel-metal hydride battery. Note that the power storage device includes a first power storage unit, a second power storage unit, and a current maintenance circuit. The power storage device may include another power storage unit. Other power storage units include, for example, a capacitor connected in parallel with the first power storage unit. The power storage device does not necessarily have to be unitized as a whole. In other words, the power storage units forming the power storage device do not necessarily need to be physically integrated. Each power storage unit may be separately installed at different positions in the straddle-type vehicle while being electrically connected to each other.

The maximum charge rate is the maximum charge rate allowed by the power storage unit. The charge rate represents the speed of charging. The unit is C. In the case of constant current charging measurement, 1C is defined as the magnitude of the current that fully charges the capacity of the battery in 1 hour. For example, if the capacity of the battery is 2Ah, 1C is 2A.

A permanent magnet motor generator functions as a generator. Also, the permanent magnet motor generator functions as a motor. A permanent magnet motor generator can function as the starting motor for the engine. The permanent magnet type motor generator is not particularly limited, and for example, it may not function as a starter motor and may have a function of assisting the drive by the engine during acceleration of the straddle-type vehicle. Also, the permanent magnet motor generator may have, for example, both the function of assisting the drive by the engine and the function of the starting motor.

A permanent magnet motor generator, for example, receives electric power to drive a crankshaft of an engine. A permanent magnet motor generator is connected to a crankshaft, for example, without a clutch. In this case, the permanent magnet type motor generator can start the engine even if the clutch is in the power disengaged state. Further, the permanent magnet motor generator can generate power even when the straddle-type vehicle is in a stopped state.

The connection configuration of the permanent magnet motor generator is not particularly limited, and for example, a clutch or transmission may be interposed between the crankshaft and the permanent magnet motor generator. In this case, the permanent magnet motor generator can accelerate the straddle-type vehicle regardless of the state of the engine. Also, the permanent magnet motor generator can generate power from the wheels regardless of the state of the engine. In this case, the straddle-type vehicle may have a starter motor separate from the permanent magnet motor generator.

A permanent magnet motor generator has a permanent magnet. For example, the configuration in which the rotor is provided with field coils instead of permanent magnets is different from the permanent magnet type motor generator in this configuration.

“Electrically disconnecting” means opening a part of a closed electric power circuit including a target, for example, by operating a switch or a relay. “Electrically disconnecting” also includes switching a transistor that forms a closed circuit from a conducting state to a non-conducting state. In contrast, "without electrical disconnection" means maintaining a closed circuit of electrical power including the object. The state of "without electrical disconnection" includes a state in which no current flows through the object. For example, if the object is a charged capacitor and a voltage equal to the voltage across the capacitor is applied to the capacitor, no current flows through the capacitor, but it is not electrically disconnected.

The engine is, for example, a single-cylinder engine, a two-cylinder engine, an uneven-combustion three-cylinder engine, or an uneven-combustion four-cylinder engine. The engine is, for example, an engine with less than three cylinders. A two-cylinder engine may be a differential combustion engine having two cylinders. An example of an unequal interval combustion engine having two cylinders is a V-type engine. However, the engine is not particularly limited, and may be an equal interval combustion type multi-cylinder engine.

A straddle-type vehicle refers to a vehicle in which the driver sits astride a saddle. A straddle-type vehicle is a vehicle provided with a saddle-type seat. A straddle-type vehicle is a vehicle in which a driver rides in a riding style. A straddle-type vehicle is an example of a vehicle. A straddle-type vehicle is, for example, a vehicle that leans into turns, and is configured to lean toward the center of a curve when turning.
A straddle-type vehicle is, for example, a motorcycle. Motorcycles are not particularly limited, and examples thereof include scooter, moped, off-road, and on-road motorcycles. Moreover, the straddle-type vehicle is not limited to a motorcycle, and may be, for example, a tricycle. Further, the straddle-type vehicle may be, for example, an ATV (All-Terrain Vehicle).

The terminology used herein is for the purpose of defining particular embodiments only and is not intended to be limiting of the invention.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed constructs.
As used herein, the use of the terms "including,""comprising," or "having," and variations thereof, refers to the described features, steps, operations, While specifying the presence of elements, components and/or their equivalents, it can include one or more of steps, actions, elements, components and/or groups thereof.
As used herein, the terms "attached", "coupled" and/or their equivalents are used broadly and include both direct and indirect attachment and coupling unless otherwise specified. encompasses
Unless defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
Terms such as those defined in commonly used dictionaries are to be construed to have a meaning consistent with their meaning in the context of the relevant technology and this disclosure, and are expressly defined herein. not be construed in an ideal or overly formal sense unless explicitly stated.
In describing the invention, it is understood that techniques and numerous steps are disclosed.
Each of these has individual benefits, and each can also be used with one or more, or possibly all, of the other disclosed techniques.
Therefore, for the sake of clarity, this description refrains from unnecessarily repeating all possible combinations of individual steps.
Nevertheless, the specification and claims should be read with the understanding that all such combinations are within the scope of the invention and claims.
A new straddle-type vehicle is described herein.
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the invention.
However, it will be obvious to those skilled in the art that the present invention may be practiced without these specific details.
The present disclosure should be considered exemplary of the invention and is not intended to limit the invention to the specific embodiments illustrated by the following drawings or description.

According to the present invention, it is possible to realize a straddle-type vehicle that can be made compact while suppressing deterioration in engine starting performance.

1 is a diagram schematically showing a straddle-type vehicle according to an embodiment of the present invention; FIG. 2 is a block diagram showing a configuration example of a current maintenance circuit shown in FIG. 1; FIG. FIG. 2 is a chart showing an outline of voltage changes during charging of an example of the voltage of the first power storage unit and the second power storage unit shown in FIG. 1 ; FIG. (A) is a side view showing a first modification of the arrangement of a power storage device in a straddle-type vehicle. (B) is a side view showing a second modification of the arrangement of the power storage device in the straddle-type vehicle. FIG. 2 is a diagram schematically showing a straddle-type vehicle and an electrical system as an application example of the embodiment shown in FIG. 1; FIG. 6 is a partial cross-sectional view schematically showing the schematic configuration of the engine unit shown in FIG. 5; FIG. 7 is a cross-sectional view showing a cross section perpendicular to the rotation axis of the permanent magnet motor generator shown in FIG. 6; FIG. 11 is a chart showing an outline of voltage changes during charging of a second application example having different types of second power storage units; FIG. 2 is a diagram showing an example of a variation of the power storage device shown in FIG. 1; FIG. 2 is a block diagram showing a variation of the electrical configuration of the straddle-type vehicle shown in FIG. 1; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

FIG. 1 is a diagram schematically showing a straddle-type vehicle according to one embodiment of the present invention. Part (a) of FIG. 1 is a side view of a straddle-type vehicle. Part (b) of FIG. 1 is a block diagram showing a schematic electrical configuration of the straddle-type vehicle shown in Part (a).

A straddle-type vehicle 1 shown in FIG. The straddle-type vehicle 1 also includes an electric auxiliary machine L. As shown in FIG. The power storage device 4 includes a first power storage unit 41 , a second power storage unit 42 , and a current maintenance circuit 43 . That is, the straddle-type vehicle 1 includes wheels 3a and 3b, an engine 10, a permanent magnet motor generator 20, a first power storage unit 41, a second power storage unit 42, a current maintenance circuit 43, and an inverter 21. Prepare.
The straddle-type vehicle 1 also includes a vehicle body 2 . FIG. 1 shows a lean vehicle as an example of the straddle-type vehicle 1 . A lean vehicle leans leftward during a left turn, and leans rightward during a right turn.

The wheels 3a, 3b provided in the straddle-type vehicle 1 include a front wheel 3a and a rear wheel 3b. The rear wheels 3b are drive wheels.

The engine 10 has a crankshaft 15 .
Engine 10 outputs power through crankshaft 15 . The engine 10 outputs torque from the crankshaft 15 for driving the wheels 3b. The wheels 3b receive power from the crankshaft 15 and cause the straddle-type vehicle 1 to travel.
Power output from the engine 10 can be transmitted to the wheels 3b via, for example, a transmission and a clutch.

The electric auxiliary machine L is an electric device mounted on the straddle-type vehicle 1 . The electric auxiliary machine L operates by being supplied with electric power.
The electric auxiliary machine L is, for example, an engine auxiliary machine that operates to cause the engine 10 to perform combustion. The engine accessories include, for example, a fuel injector 18 and an ignition device 19 (see FIG. 6). The fuel injection device 18 injects fuel toward or within the engine 10 . The ignition device 19 ignites the fuel inside the engine 10 .

Permanent magnet motor generator 20 is provided at one end of crankshaft 15 .
Permanent magnet type motor generator 20 has a permanent magnet. More specifically, the permanent magnet motor generator 20 includes a permanent magnet section 37 made of permanent magnets.
Permanent magnet motor generator 20 also serves as a starter for starting engine 10 . Permanent magnet type motor generator 20 is a permanent magnet type starter generator. Permanent magnet motor generator 20 starts engine 10 by rotating crankshaft 15 . Permanent magnet motor generator 20 is also driven by engine 10 to generate power.

The power storage device 4 is a device capable of charging and discharging electricity. The power storage device 4 stores electric power.
The power storage device 4 outputs the charged power to the outside. The power storage device 4 supplies electric power to the permanent magnet motor generator 20 . The power storage device 4 supplies electric power to the permanent magnet motor generator 20 when the engine 10 is started. Further, for example, after the engine 10 is started, the power storage device 4 is charged with electric power generated by the permanent magnet motor generator 20 .

The power storage device 4 includes a first power storage unit 41 , a second power storage unit 42 , and a current maintenance circuit 43 .
The first power storage unit 41 is a battery that stores power. First power storage unit 41 has a maximum rated voltage of 12V or higher. For example, the first power storage unit 41 is a battery having a nominal voltage of 12V. For example, the first power storage unit 41 is a lead battery. The first power storage unit 41 has, for example, a maximum rated voltage of 14V. First power storage unit 41 has a capacity capable of being charged with electric power for starting engine 10 at least once.
Second power storage unit 42 is always connected in series with first power storage unit 41 . Second power storage unit 42 has a maximum charge rate that is greater than twice the maximum charge rate of first power storage unit 41 . For example, the second power storage unit 42 is a battery that stores power. Second power storage unit 42 has a capacity capable of being charged with electric power sufficient to start engine 10 at least once.
The charge rate represents the speed of charging. The unit is C [cy]. 1C is defined as the amount of current that fully charges the capacity of the battery in 1 hour. The maximum charge rate is the maximum charge rate allowed.
The combination of the first power storage unit 41 and the second power storage unit 42 is not limited to this. As described above, second power storage unit 42 has a maximum charge rate that is greater than twice the maximum charge rate of first power storage unit 41 .

Examples of the first power storage unit 41 include a battery having a maximum charging rate of 1C or less.

The type of the first power storage unit 41 is, for example, a lead battery or a lithium ion battery using a carbon material for the negative electrode.

As the second power storage unit 42, for example, a battery having a maximum charge rate of 20C or higher is used.

The types of the second power storage unit 42 are, for example, a nickel-metal hydride battery and a lithium-ion battery using lithium titanate as a negative electrode. Examples of the type of the second power storage unit 42 include a capacitor. Examples include electric double layer capacitors and lithium ion capacitors.

However, as second power storage unit 42, a device having a maximum charge rate higher than twice the maximum charge rate of first power storage unit 41 can be employed.

For example, the first power storage unit 41 is a battery with a maximum charge rate of 1C, and the second power storage unit 42 is a battery with a maximum charge rate of 40C. For example, the first power storage unit 41 is a lead battery having a maximum charge rate of 1C. For example, the first power storage unit 41 is a lead battery with a capacity of 6 Ah and a maximum charging current of 6A. In this case, the maximum charging rate of first power storage unit 41 is 1C.
The second power storage unit 42 is a nickel metal hydride battery with a maximum charge rate of 10C. For example, the second power storage unit 42 is a nickel metal hydride battery with a capacity of 1 Ah and a maximum charging current of 20A. In this case, the maximum charging rate of first power storage unit 41 is 20C.

Current maintenance circuit 43 outputs current from first power storage unit 41 and second power storage unit 42 connected in series to permanent magnet motor generator 20 via inverter 21 when engine 10 is started. In addition, current maintaining circuit 43 maintains a state in which charging current flows to first power storage unit 41 without electrically disconnecting second power storage unit 42 at least while inverter 21 charges first power storage unit 41 . .
Current maintenance circuit 43 allows a charging current to flow to first power storage unit 41 so that the voltage applied to second power storage unit 42 does not exceed the upper limit voltage set for second power storage unit 42 while power storage device 4 is being charged. maintain state. Here, “while the power storage device 4 is being charged” refers to at least the time while the first power storage unit 41 is being charged. Current maintaining circuit 43 maintains a state in which charging current flows to the first power storage unit without electrically disconnecting second power storage unit 42 .
The upper limit voltage set for second power storage unit 42 is the upper limit that can be applied to second power storage unit 42 . The upper limit voltage set for second power storage unit 42 is lower than the maximum rated voltage of second power storage unit 42 . For example, a device having a maximum rated voltage lower than the maximum rated voltage of the first power storage unit 41 is employed as the second power storage unit 42 . In this case, an upper limit voltage lower than the maximum rated voltage of first power storage unit 41 is adopted. For example, a first power storage unit 41 with a nominal voltage of 12V and a second power storage unit 42 with an upper limit voltage of 6V are employed. However, the combination of first power storage unit 41 and second power storage unit 42 is not limited to this. For example, when first power storage unit 41 with a maximum rated voltage of 14V is employed, the maximum rated voltage of second power storage unit 42 is lower than 14V. For example, the upper limit voltage of the second power storage unit 42 is lower than 14V. Also, the maximum rated voltage of first power storage unit 41 may be other than 14V. The maximum rated voltage of the first power storage unit 41 may be 28V or 7V, for example.
As the current maintaining circuit 43 , for example, a circuit connected in parallel with the second power storage unit 42 and connected in series with the first power storage unit 41 can be used. In this case, when the voltage applied to second power storage unit 42 exceeds the upper limit voltage, current maintenance circuit 43 causes the current flowing from power storage device 4 to flow to first power storage unit 41 . For example, the current maintaining circuit 43 has a circuit that detects when the voltage of the second power storage unit 42 exceeds the upper limit voltage, and a circuit that allows the current flowing from the inverter 21 to flow to the first power storage unit 41 in response to the detection. .

However, the current maintaining circuit 43 may be, for example, a number of low-voltage diodes connected in series corresponding to the upper limit voltage. Further, current maintenance circuit 43 may be connected in series with second power storage unit 42 .

The inverter 21 supplies electric power generated by the permanent magnet motor generator 20 to the power storage device 4, for example, when the engine 10 is in combustion operation. In this case, inverter 21 rectifies the current generated by permanent magnet motor generator 20 .
Inverter 21 rotates permanent magnet motor generator 20 by supplying electric power to permanent magnet motor generator 20 . Inverter 21 controls the current by controlling the on/off of the current flowing through stator winding W of permanent magnet motor generator 20 .

The inverter 21 includes a switching section 211 and a control device 60 . Control device 60 is physically integrated with inverter 21 . Control device 60 controls the voltage output from inverter 21 by controlling the operation of switching unit 211 of inverter 21 . Control device 60 controls the current flowing between permanent magnet motor generator 20 and power storage device 4 by controlling the operation of switching unit 211 of inverter 21 . Control device 60 also controls the operation of permanent magnet motor generator 20 . The control device 60 controls the voltage output from the inverter 21 by, for example, phase control method or vector control.

Control device 60 controls inverter 21 so that the voltage output from inverter 21 is lower than the sum of the maximum rated voltage of first power storage unit 41 and the maximum rated voltage of second power storage unit 42, for example. Control. Control device 60 controls inverter 21 so that the voltage output from inverter 21 is lower than the sum of the maximum rated voltage of first power storage unit 41 and the upper limit voltage of second power storage unit 42, for example. do.

For example, control device 60 causes inverter 21 to supply current from power storage device 4 to permanent magnet motor generator 20 in response to a signal from starter switch 6 . Electric power is thereby supplied from the power storage device 4 to the permanent magnet type motor generator 20, and the engine 10 is started.
When the engine 10 is started, the power storage device 4 can drive the permanent magnet type motor generator 20 with a voltage higher than 12V generally employed in the past. Therefore, the permanent magnet type motor generator 20 can output torque greater than that of 12V. Therefore, deterioration of the performance of the permanent magnet type motor generator 20 is suppressed.

After the engine 10 is started, that is, after the combustion operation is started, the control device 60 controls the inverter 21 so that the current from the permanent magnet type motor generator 20 flows to the power storage device 4 . As a result, power storage device 4 is charged with power generated by permanent magnet motor generator 20 .
After the engine 10 is started, that is, after the combustion operation is started, the control device 60 transfers the electric power of the power storage device 4 to the inverter 21 and the permanent magnet motor generator 20 according to the operation of the acceleration instruction unit 8 (see FIG. 5). can be supplied. More specifically, the control device 60 supplies electric power from the power storage device 4 to the permanent magnet motor generator 20 while the straddle-type vehicle 1 is running, and assists the permanent magnet motor generator 20 in rotating the crankshaft 15 . Let As a result, acceleration of the straddle-type vehicle 1 by the engine 10 is assisted by the permanent magnet motor generator 20 .

The control device 60 also functions as an engine control unit that controls fuel supply and combustion to the engine 10 . Control device 60 controls combustion of engine 10 by controlling the operation of electric auxiliary machine L that functions as an engine auxiliary machine.
The control device 60 includes a central processing unit and memory (not shown). Control device 60 controls combustion of engine 10 by executing a program stored in memory.
Control device 60 operates with the power of power storage device 4 . More specifically, control device 60 operates at an operating voltage that is down-converted from the voltage of power storage device 4 to apply to control device 60 . A down converter is provided in the inverter 21, for example. For example, if the power storage device 4 has a battery and a capacitor, the control device 60 may operate with an operating voltage down-converted from the voltage of the battery.

FIG. 2 is a block diagram showing a configuration example of the current maintaining circuit shown in FIG. FIG. 2 also shows the first power storage unit 41 and the second power storage unit 42 for easy understanding of the function of the current maintenance circuit. FIG. 2 shows a capacitor as an example of the second power storage unit 42 .
The example current sustaining circuit 43 a shown in FIG. 2 includes a voltage drop generator 431 . Voltage drop generation unit 431 is electrically connected in parallel with second power storage unit 42 . Since voltage drop generation unit 431 is not connected in series with second power storage unit 42 , it does not cut off the current path of second power storage unit 42 . Voltage drop generator 431 is not a switch.
Voltage drop generation unit 431 generates a voltage drop so that the voltage applied to second power storage unit 42 does not exceed the upper limit voltage set for second power storage unit 42 . More specifically, the amount of voltage drop generated by voltage drop generator 431 is substantially equal to the voltage applied to second power storage unit 42 . Therefore, the voltage drop generator 431 produces a voltage drop that does not exceed the upper limit voltage.
That is, the voltage drop generation unit 431 electrically connected in parallel with the second power storage unit 42 generates a voltage drop that does not exceed the upper limit voltage without interrupting the current path of the second power storage unit 42 .

More specifically, voltage drop generation unit 431 reduces the internal resistance as the voltage applied to the second power storage unit increases and approaches the upper limit voltage. Thereby, the amount of voltage drop is controlled so as not to exceed the upper limit voltage.

More specifically, the current maintenance circuit 43 a includes a voltage drop generator 431 , a voltage drop controller 432 , a feedback section 433 and a reference voltage generator 434 .
The reference voltage generator 434 generates a reference voltage related to the upper limit voltage. Voltage drop control unit 432 controls the amount of voltage drop in voltage drop generation unit 431 based on the reference voltage and the voltage applied to the second power storage unit. The feedback unit 433 reflects the output voltage of the voltage drop control unit 432 on the input.
The voltage drop generation unit 431 controls the amount of voltage drop in analog according to the voltage applied to the second power storage unit.

Note that the configuration of the current maintenance circuit 43 shown in FIG. 1 is not limited to the current maintenance circuit 43a shown in FIG. Although a bipolar transistor is shown as the voltage drop generator 431, the voltage drop generator 431 may be a current controlled device such as a field effect transistor (FET). Also, although an amplifier is shown as the voltage drop controller 432, the voltage drop controller 432 may be, for example, a digital control circuit.

FIG. 3 is a chart showing an outline of voltage changes during charging of an example of the voltage of the first power storage unit 41 and the second power storage unit 42 shown in FIG.

A combination of a battery with a nominal voltage of 12 V as an example of the first power storage unit 41 and a battery with a nominal voltage of 6 V as an example of the second power storage unit 42 is shown. The voltage of the first power storage unit 41 before charging is 11 V due to discharging. The voltage of the second power storage unit 42 before charging is 5.5 V due to discharging. Second power storage unit 42 has a maximum charge rate that is greater than twice the maximum charge rate of first power storage unit 41 .

When first power storage unit 41 and second power storage unit 42 that are connected in series are charged at 18 V, first voltage V1 of first power storage unit 41 and second voltage V2 of second power storage unit 42 increase with the lapse of charging time. rises. Since the second power storage unit 42 has a maximum charging rate greater than twice the maximum charging rate of the first power storage unit 41 , the second voltage V2 of the second power storage unit 42 is equal to the first voltage V1 of the first power storage unit 41 rises rapidly compared to That is, second power storage unit 42 is charged more rapidly than first power storage unit 41 .
Voltage VT of power storage device 4 is the sum of first voltage V1 of first power storage unit 41 and second voltage V2 of second power storage unit 42 . The voltage VT of the power storage device 4 is higher than the voltage VT' of the power storage device when the scale of the first power storage unit 41 is simply 1.5 times the size of the first power storage unit 41 without the second power storage unit, for example. For example, the time t1 from the start of charging until the voltage VT of the power storage device 4 reaches 17.5 V, which is about 95% of the charging voltage, is simply It is shorter than the time t2 until the voltage VT' of the power storage device reaches 17.5V when it is multiplied by 1.5.

In this way, the first power storage unit 41 and the second power storage unit 42 connected in series make the voltage VT of the power storage device 4 lower than, for example, the voltage VT′ when the scale of the first power storage unit 41 is simply increased. big.
As shown in the example of FIG. 3, since the second power storage unit 42 is charged in a shorter period than the first power storage unit 41, the power storage device 4 is charged from a discharged state to a large amount in a short time after charging is started. Voltage VT can be output. For example, even when the engine 10 is started at time t1, the permanent magnet motor generator 20 can be driven at 17V, which is higher than 12V generally used in the past.

The combination of 12V and 6V has been described with reference to FIG. However, in the straddle-type vehicle 1 of the present embodiment, the voltage when the power storage device 4 discharges is adjusted by adjusting the type and configuration of the second power storage unit 42 and the upper limit voltage set value of the current maintaining circuit 43. , can be easily adjusted. In other words, a voltage higher than the voltage of first power storage unit 41 can be easily set as the output voltage of power storage device 4 . For example, when a battery with a nominal voltage of 12 V is used as the first power storage unit 41, it is easy to adjust the voltage that can be output by the power storage device 4 in a short charging time after the power storage device 4 is discharged to a required voltage higher than 12 V. is.
When power storage device 4 can output a large voltage, it is permissible to increase the wiring distance of power storage device 4-inverter 21-permanent magnet motor generator 20 for a certain allowable range of loss. As a result, the degree of freedom in layout of the power storage device 4 and the inverter 21 in the vehicle body is increased.

FIG. 4A is a side view showing a first modification of the arrangement of the power storage device 4 in the straddle-type vehicle 1. FIG. FIG. 4B is a side view showing a second modification of the arrangement of the power storage device 4 in the straddle-type vehicle 1. As shown in FIG.

In a first modification shown in FIG. 4A, a power storage device 4 is arranged at the rear end portion of the vehicle body 2 . In a second modification shown in FIG. 4B, a power storage device 4 is arranged at the front end of the vehicle body 2 .
Since it is permissible to lengthen the wiring distance of power storage device 4-inverter 21-permanent magnet type motor generator 20, as shown in FIG. Layout freedom increases. Therefore, the arrangement positions of the power storage device 4 and the inverter 21 can be adjusted so as to suppress waste of space that occurs when the power storage device 4 and the inverter 21 are arranged. Therefore, the vehicle body 2 can be made compact.

Thus, according to the straddle-type vehicle 1, the vehicle body can be made compact while suppressing deterioration in engine starting performance.

[First application example]
Next, an application example of the embodiment will be described with reference to FIG.

FIG. 5 is a diagram schematically showing a saddle-ride type vehicle 1 and an electrical system as an application example of the embodiment shown in FIG. Part (a) of FIG. 5 is a plan view of the straddle-type vehicle 1 . Part (b) of FIG. 5 is a side view of the straddle-type vehicle 1 . Part (c) of FIG. 5 is an actual wiring diagram schematically showing the connection of the electrical system of the straddle-type vehicle 1 .
In the application examples shown in FIG. 5 and subsequent drawings, elements corresponding to the embodiment shown in FIG. 1 are assigned the same reference numerals as in FIG.

A straddle-type vehicle 1 shown in FIG. 5 includes a vehicle body 2 . A vehicle body 2 is provided with a seat 2a for a driver to sit on. The driver sits astride the seat 2a. FIG. 5 shows a motorcycle as an example of the straddle-type vehicle 1 .

The straddle-type vehicle 1 has front wheels 3a and rear wheels 3b. The tread surfaces of the wheels 3a and 3b of the straddle-type vehicle 1 have an arcuate cross-sectional shape in a state in which they do not contact the road surface.

The engine 10 constitutes an engine unit EU. That is, the straddle-type vehicle 1 includes an engine unit EU.
Engine unit EU includes an engine 10 and a permanent magnet motor generator 20 .
Engine 10 outputs power through crankshaft 15 . The engine 10 outputs torque from the crankshaft 15 for driving the wheels 3b. The wheels 3b receive power from the crankshaft 15 and cause the straddle-type vehicle 1 to travel. The engine 10 has a displacement of 100 mL or more, for example. Engine 10 has, for example, a displacement of less than 400 mL.
The straddle-type vehicle 1 also includes a transmission CVT and a clutch CL. Power output from the engine 10 is transmitted to the wheels 3b via the transmission CVT and the clutch CL.

Permanent magnet motor generator 20 is driven by engine 10 to generate electric power. A permanent magnet type motor generator 20 shown in FIG. 5 is a magnet type starter generator.
The permanent magnet motor generator 20 has a rotor 30 and a stator 40 (see FIG. 6). The rotor 30 includes a permanent magnet portion 37 made of permanent magnets. The rotor 30 is rotated by power output from the crankshaft 15 . Stator 40 is arranged to face rotor 30 .

The power storage device 4 is a device that can be charged and discharged. The power storage device 4 outputs the charged power to the outside. The power storage device 4 supplies electric power to the permanent magnet motor generator 20 and the electric auxiliary machine L. As shown in FIG. The power storage device 4 supplies electric power to the permanent magnet motor generator 20 when the engine 10 is started. Further, power storage device 4 is charged with electric power generated by permanent magnet type motor generator 20 .

The straddle-type vehicle 1 includes an inverter 21 . Inverter 21 includes a plurality of switching units 211 that control current flowing between permanent magnet motor generator 20 and power storage device 4 .

Permanent magnet type motor generator 20 rotates crankshaft 15 with electric power of power storage device 4 . This causes the permanent magnet motor generator 20 to start the engine 10 .

The straddle-type vehicle 1 has a main switch 5 . The main switch 5 is a switch for supplying electric power to the electric auxiliary machine L (see FIG. 5(c)) provided in the straddle-type vehicle 1 according to the operation. The electric auxiliary machine L comprehensively represents devices that operate while consuming electric power, except for the permanent magnet motor generator 20 . The electric auxiliary machine L includes, for example, a headlight 9, a fuel injection device 18, and an ignition device 19 (see FIG. 6).
The straddle-type vehicle 1 has a starter switch 6 . The starter switch 6 is a switch for starting the engine 10 according to operation. The straddle-type vehicle 1 has a main relay 75 . Main relay 75 opens and closes a circuit including electric auxiliary machine L according to a signal from main switch 5 .
The straddle-type vehicle 1 includes an acceleration instructing section 8 . The acceleration instructing unit 8 is an operator for instructing acceleration of the straddle-type vehicle 1 according to the operation. Specifically, the acceleration instruction unit 8 is an accelerator grip.

The power storage device 4 has, for example, a first power storage unit 41 that operates at 12 V, and a second power storage unit 42 that is connected in series with this battery. The first power storage unit 41 is, for example, a lead battery. The capacitor is, for example, an electric double layer capacitor (EDLC).
Moreover, the power storage device 4 has a current maintenance circuit 43 that supplies the current input to the power storage device 4 to the battery instead of the capacitor when the voltage of the capacitor exceeds 6V.
The power storage device 4 is charged with 18V and outputs 18V. However, the charging voltage and the output voltage also fluctuate depending on the state of charge of the power storage device 4 and the rotational speed of the crankshaft 15 . A voltage range that includes 18V is referred to as an 18V system voltage.

With the configuration shown in FIG. 5 , power storage device 4 supplies electric power to permanent magnet motor generator 20 when engine 10 is started. A permanent magnet type motor generator 20 can be driven with an 18V system voltage. Therefore, the permanent magnet motor generator 20 can output torque greater than that of 12V, for example.

As shown in part (c) of FIG. 5, the permanent magnet type motor generator 20, the power storage device 4, the main relay 75, the inverter 21, and the electric auxiliary machine L are electrically connected by wiring J. As shown in FIG. For ease of viewing the reference numerals, the wiring reference (J) is attached to part of the wiring shown in part (c) of FIG.
The wiring J is composed of, for example, a lead wire. The wiring J may be composed of a plurality of connected lead wires. Also, the wiring J may include a connector, a fuse, and a connection terminal for relaying lead wires. Illustrations of connectors, fuses, and connection terminals are omitted. Also, in the actual wiring diagram of part (c) of FIG. 5, the connection of the positive electrode region is shown. The negative or ground area is electrically connected through the vehicle body 2 . More specifically, the negative electrode region is electrically connected via a metal frame (not shown) of the vehicle body 2 . The distance of electrical connection of each device through the vehicle body 2 is usually equal to or shorter than the connection of the positive electrode region by lead wires or the like. Therefore, in part (c) of FIG. 5, the illustration of the connection of the negative electrode region by the vehicle body 2 is omitted, and the wiring of the positive electrode region will be mainly described.
The wiring J shown in FIG. 5 is combined with other wiring provided in the vehicle to form a wire harness (not shown). Part (c) of FIG. 5 shows only the wires J that electrically connect the devices shown in the figure.
Part (c) of FIG. 5 schematically shows the connection relationship of the wiring J between devices and the distance of the wiring J. FIG.

[Engine unit]
FIG. 6 is a partial cross-sectional view schematically showing the schematic configuration of the engine unit EU shown in FIG.

The engine unit EU has an engine 10 . The engine 10 includes a crankcase 11 , cylinders 12 , pistons 13 , connecting rods 14 and crankshafts 15 . The piston 13 is provided in the cylinder 12 so as to be able to reciprocate.
The crankshaft 15 is rotatably provided within the crankcase 11 . Crankshaft 15 is connected to piston 13 via connecting rod 14 . A cylinder head 16 is attached to the upper portion of the cylinder 12 . A combustion chamber is formed by the cylinder 12 , the cylinder head 16 and the piston 13 . The crankshaft 15 is rotatably supported by the crankcase 11 . A permanent magnet motor generator 20 is attached to one end portion 15 a of the crankshaft 15 . A transmission CVT is attached to the other end portion 15 b of the crankshaft 15 . The transmission CVT can change the gear ratio, which is the ratio of the rotational speed of the output to the rotational speed of the input. The transmission CVT can change the gear ratio corresponding to the rotation speed of the wheels with respect to the rotation speed of the crankshaft 15 .

The engine unit EU is provided with a fuel injection device 18 . The fuel injector 18 supplies fuel to the combustion chamber by injecting fuel. A fuel injection device 18 injects fuel into the air flowing through the intake passage Ip. A mixture of air and fuel is supplied to the combustion chambers of engine 10 .
An ignition device 19 is provided in the engine unit EU. The ignition device 19 has an ignition plug 19a and an ignition voltage generation circuit 19b. The ignition plug 19a is provided in the engine 10. As shown in FIG. The ignition plug 19a is electrically connected to the ignition voltage generating circuit 19b.
The fuel injection device 18 and the ignition device 19 are examples of the electric auxiliary machine L shown in FIG. The fuel injection device 18 and the ignition device 19 are examples of engine accessories. The fuel injector 18 and ignition device 19 operate on the 18V system voltage.

Engine 10 is an internal combustion engine. The engine 10 is supplied with fuel. The engine 10 outputs power by a combustion operation of combusting an air-fuel mixture. That is, the piston 13 reciprocates due to the combustion of the air-fuel mixture containing the fuel supplied to the combustion chamber. The crankshaft 15 rotates in conjunction with the reciprocating motion of the piston 13 . Power is output to the outside of engine 10 via crankshaft 15 .
Fuel injector 18 regulates the power output from engine 10 by adjusting the amount of fuel supplied. Fuel injector 18 is controlled by controller 60 . Fuel injector 18 is controlled to deliver an amount of fuel based on the amount of air being supplied to engine 10 . The ignition device 19 ignites the gas in which fuel and air are mixed. Fuel injectors 18 and igniters 19 are engine accessories that operate to cause engine 10 to combust.
Engine 10 outputs power through crankshaft 15 . The power of the crankshaft 15 is transmitted to the wheels 3b via the transmission CVT and the clutch CL (see part (b) of FIG. 5).

The crankcase 11 is configured so that the inside is lubricated with lubricating oil (part (b) in oil FIG. 5). Permanent magnet type motor generator 20 is provided at a position in contact with lubricating oil.

The engine 10 has, during four strokes, a high load region in which the load that rotates the crankshaft 15 is large, and a low load region in which the load that rotates the crankshaft 15 is smaller than the load in the high load region. The high load region refers to a region in which the load torque in one combustion cycle of the engine 10 is higher than the average value of the load torque in one combustion cycle. The low load region is a region in which the load torque in one combustion cycle of the engine 10 is lower than the average value of the load torque in one combustion cycle. Taking the rotation angle of the crankshaft 15 as a reference, the low load range is wider than the high load range. More specifically, the engine 10 rotates forward while repeating four strokes of an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. The compression stroke has overlap with the high load region. Engine 10 is a single cylinder engine.

FIG. 7 is a cross-sectional view showing a cross section perpendicular to the rotation axis of permanent magnet motor generator 20 shown in FIG.
The permanent magnet motor generator 20 will be described with reference to FIGS. 6 and 7. FIG.

Permanent magnet motor generator 20 has a rotor 30 and a stator 40 . The permanent magnet type motor generator 20 of this application example is of a radial gap type. Permanent magnet motor generator 20 is of the outer rotor type. That is, the rotor 30 is an outer rotor. Stator 40 is an inner stator.
The rotor 30 has a rotor body portion 31 . The rotor main body 31 is made of, for example, a ferromagnetic material. The rotor main body 31 has a cylindrical shape with a bottom. The rotor body portion 31 has a tubular boss portion 32 , a disk-shaped bottom wall portion 33 , and a tubular back yoke portion 34 . The bottom wall portion 33 and the back yoke portion 34 are integrally formed. Note that the bottom wall portion 33 and the back yoke portion 34 may be configured separately. The bottom wall portion 33 and the back yoke portion 34 are fixed to the crankshaft 15 via the cylindrical boss portion 32 . The rotor 30 is not provided with windings to which current is supplied.

The rotor 30 has a permanent magnet portion 37 . The rotor 30 has a plurality of magnetic pole portions 37a. A plurality of magnetic pole portions 37 a are formed by the permanent magnet portion 37 . A plurality of magnetic pole portions 37 a are provided on the inner peripheral surface of the back yoke portion 34 . In this application example, the permanent magnet portion 37 has a plurality of permanent magnets. That is, the rotor 30 has multiple permanent magnets. The plurality of magnetic pole portions 37a are provided for each of the plurality of permanent magnets.
It should be noted that the permanent magnet portion 37 can also be formed by one annular permanent magnet. In this case, one permanent magnet is magnetized such that a plurality of magnetic pole portions 37a are aligned on the inner peripheral surface.

A plurality of magnetic pole portions 37 a are provided such that N poles and S poles are alternately arranged in the circumferential direction of permanent magnet motor generator 20 . In this application example, the rotor 30 facing the stator 40 has 24 magnetic poles. The number of magnetic poles of the rotor 30 means the number of magnetic poles facing the stator 40 . No magnetic body is provided between the magnetic pole portion 37 a and the stator 40 .
Magnetic pole portion 37 a is provided radially outward of stator 40 of permanent magnet motor generator 20 . The back yoke portion 34 is provided radially outward of the magnetic pole portion 37a. Permanent magnet type motor generator 20 has more magnetic pole portions 37 a than the number of tooth portions 45 .
The rotor 30 may be of an embedded magnet type (IPM type) in which the magnetic pole portions 37a are embedded in a magnetic material, but may be of a surface magnet type in which the magnetic pole portions 37a are exposed from the magnetic material as in this application example. (SPM type) is preferred.

The stator 40 has a stator core ST and a plurality of stator windings W. As shown in FIG. The stator core ST has a plurality of teeth 45 spaced apart in the circumferential direction. The plurality of tooth portions 45 integrally extend radially outward from the stator core ST. In this application example, a total of 18 tooth portions 45 are provided at intervals in the circumferential direction. In other words, the stator core ST has a total of 18 slots SL formed at intervals in the circumferential direction. The tooth portions 45 are arranged at regular intervals in the circumferential direction.

The rotor 30 has more magnetic pole portions 37 a than the tooth portions 45 . The number of magnetic pole pieces is 4/3 of the number of slots.

A stator winding W is wound around each tooth 45 . That is, the multi-phase stator windings W are provided so as to pass through the slots SL. FIG. 7 shows the stator winding W in the slot SL.

Permanent magnet motor generator 20 is a three-phase generator. Each stator winding W belongs to one of the U phase, V phase, and W phase. The stator windings W are arranged, for example, in order of U-phase, V-phase, and W-phase.

When the engine 10 is in operation while the straddle-type vehicle 1 is running, the power storage device 4 is charged with electric power generated by the permanent magnet motor generator 20 . When the power storage device 4 is fully charged, the electric power generated by the permanent magnet type motor generator 20 is not used for charging and is consumed as heat due to, for example, short-circuiting of windings. Further, when the rotation speed of crankshaft 15 increases to such an extent that the voltage output from inverter 21 to power storage device 4 cannot be suppressed to the rated value, inverter 21 short-circuits stator winding W of permanent magnet motor generator 20. The switching unit 211 is controlled so as to The upper limit rotation speed of the crankshaft 15 at which the power storage device 4 can be charged can be set to a high value.
When the generator generates electricity, the current flowing through the stator windings W is affected by the impedance that occurs in the stator windings W themselves. Impedance is the element that impedes the flow of current through the stator windings W; Impedance includes the product of rotational speed ω and inductance. Here, the rotation speed ω actually corresponds to the number of magnetic pole portions that pass near the teeth per unit time. That is, the rotation speed ω is proportional to the ratio of the number of magnetic poles to the number of teeth in the generator and the rotation speed of the rotor.

The permanent magnet motor generator 20 shown in FIG. 7 has more magnetic pole portions 37 a than the tooth portions 45 . That is, the permanent magnet motor generator 20 has magnetic pole portions 37a in a number greater than the number of slots SL. Therefore, the stator winding W has a large impedance. Therefore, the voltage applied to the power storage device 4 is reduced compared to, for example, a case where the number of magnetic pole portions is smaller than the number of tooth portions. Therefore, the upper limit rotation speed of the crankshaft 15 can be set to a higher value than in the case of 12V, for example. Therefore, in order to increase the torque at the time of starting the permanent magnet type motor generator 20, thick windings with low electrical resistance can be employed.

In addition, in the permanent magnet motor generator 20, the temperature of the stator winding W does not or does not easily become higher than the temperature of the lubricating oil. Evaporation of lubricating oil can be suppressed. Therefore, it is possible to suppress or avoid an increase in the size of the lubricating oil cooling mechanism.

The rotor 30 is provided with a plurality of detected portions 38 provided on the rotor at intervals in the circumferential direction. A plurality of detected portions 38 are provided to detect the rotational position of the rotor 30 . Rotational positions of the rotor 30 and the crankshaft 15 can be precisely detected by the detected portion 38 .
The detected portion 38 is provided on the outer surface of the rotor 30 . The plurality of detected parts 38 are detected by magnetic action. A plurality of detected portions 38 are provided on the outer surface of the rotor 30 at intervals in the circumferential direction. In this embodiment, the plurality of detected portions 38 are provided on the outer peripheral surface of the rotor 30 at intervals in the circumferential direction.

A rotor position detection device 50 detects the position of the rotor 30 . The rotor position detection device 50 is provided at a position facing the plurality of detected portions 38 . That is, the rotor position detection device 50 is arranged at a position such that the plurality of detected portions 38 sequentially face the rotor position detection device 50 . The rotor position detection device 50 faces the path through which the detected portion 38 passes as the rotor 30 rotates. The rotor position detection device 50 is arranged at a position separated from the stator 40 . In this embodiment, the rotor position detection device 50 has the back yoke portion 34 and the permanent magnet portion 37 of the rotor 30 positioned between the rotor position detection device 50 and the stator 40 and stator windings W in the radial direction of the crankshaft 15 . are arranged to The rotor position detection device 50 is arranged outside the rotor 30 in the radial direction of the starter motor SG and faces the outer peripheral surface of the rotor 30 .

The rotor position detection device 50 has detection windings. The detection winding 51 is a winding provided separately from the stator winding W of the stator 40 . The stator winding W is supplied with a current that drives the rotor 30 of the starter motor SG by electromagnetic force, whereas the detection winding 51 is not supplied with a current that drives the rotor 30 of the starter motor SG.
Since the rotor position detection device 50 electromagnetically detects the detected portion 38, it has a higher degree of freedom in arrangement than, for example, a Hall IC. The engine unit EU can be downsized.

[Second application example]
FIG. 8 is a chart showing an outline of voltage changes during charging of the second application example having different types of second power storage units 42 .
In the second application example shown in FIG. 8, a capacitor is assumed as second power storage unit 42 . Note that the first power storage unit 41 is the same battery as the example shown in FIG.

A capacitor is an element that stores charges such as ions by using electrostatic force without depending on chemical reactions. Therefore, the voltage of the capacitor is approximately proportional to the amount of charge. For example, the voltage of the capacitor drops as the capacitor discharges.
Capacitors generally have a smaller capacity than batteries of equal volume. Capacitors also have a higher maximum charging current than batteries of equal volume because they store charge without chemical reactions. Therefore, the maximum charge rate of the capacitor is higher than that of the battery.
FIG. 8 shows an outline of a voltage change when charging starts from a state (time 0) in which the amount of charge in the second power storage unit 42, which is a capacitor, becomes almost 0% due to discharging.
At time 0, the second voltage V2b of the second power storage unit 42 whose charge amount is approximately 0% is approximately 0V.
Since the second power storage unit 42 has a large maximum charging rate, the second voltage V2b of the second power storage unit 42 rises rapidly. Second power storage unit 42 is charged more rapidly than first power storage unit 41 . When the second voltage V2b of the second power storage unit 42 reaches the upper limit voltage, the second voltage V2b is controlled to the upper limit voltage by the current maintaining circuit 43 . It is maintained at about 6V in the example of FIG. The second power storage unit 42 is charged more rapidly until the second voltage V2b of the second power storage unit 42 reaches the upper limit voltage than after the second voltage V2b reaches the upper limit voltage. Rapid charging is charging with a high charging speed, that is, charging with a large amount of charge per unit time. In the example shown in FIG. 8, the second power storage unit 42 is charged at a higher charging rate in the period before time t3 than in the period after time t3. On the other hand, the first power storage unit 41 is charged in a period before the time t3 at a lower charging rate than after the time t3. First power storage unit 41 is charged at a high charging rate by current from current maintenance circuit 43 in a period after time t3.

Voltage VTb of power storage device 4 is the sum of first voltage V1b of first power storage unit 41 and second voltage V2b of second power storage unit 42 . The time t3 from the start of charging until the voltage VTb of the power storage device 4 reaches 17.5 V, which is about 95% of the charging voltage, is, for example, when the scale of the first power storage unit 41 is simply 1 without the second power storage unit. It is shorter than the time t4 until the voltage VTb' of the power storage device 4 reaches 17.5V when the voltage is increased .5 times.

FIG. 9 is a diagram showing an example of a variation of power storage device 4 shown in FIG.

The power storage device 4 in the example shown in FIG. 9A includes a battery as a first power storage unit 41 and a battery as a second power storage unit 42 . A current maintenance circuit 43 is provided in the power storage device 4 .
The maximum charging rate of the battery as second power storage unit 42 is greater than twice the maximum charging rate of the battery as first power storage unit 41 . The maximum rated voltage of the battery as second power storage unit 42 is lower than the maximum rated voltage of the battery as first power storage unit 41 . The upper limit voltage of the battery as second power storage unit 42 is lower than the maximum rated voltage of the battery as first power storage unit 41 . The upper limit voltage of the battery as second power storage unit 42 is lower than the nominal voltage of the battery as first power storage unit 41 .
A nominal voltage of the battery as the first power storage unit 41 is, for example, 12V. The nominal voltage of the battery as the second power storage unit 42 is, for example, 6V. The upper limit voltage of the battery as the second power storage unit 42 is, for example, 6V. However, the specific voltage combination of the first power storage unit 41 and the second power storage unit 42 is not particularly limited. and 2.5V.

The power storage device 4 of the example shown in FIG. 9B includes a battery as the first power storage unit 41 and one capacitor as the second power storage unit 42 . A current maintenance circuit 43 is provided in the power storage device 4 . The maximum voltage applied to one capacitor as second power storage unit 42 is the upper limit voltage set in current maintenance circuit 43 . The upper limit voltage of current maintenance circuit 43 is set according to the withstand voltage of the capacitor and the maximum rated voltage of power storage device 4 . The upper limit voltage set in the current maintaining circuit 43 is, for example, 6V. However, the upper limit voltage is not particularly limited, and may be 2.5 V, 8 V, or 10 V depending on the withstand voltage of the capacitor and the power storage device 4 .

The power storage device 4 of the example shown in FIG. 9C includes a battery as the first power storage unit 41 and two capacitors as the second power storage unit 42 . This makes it possible to set a voltage higher than the withstand voltage of one capacitor as the upper limit voltage of the current maintaining circuit 43 . Also, the second power storage unit 42 can input and output a voltage higher than the withstand voltage of one capacitor.

The power storage device 4 of the example shown in (D) of FIG. 9 includes a battery as the first power storage unit 41 and three capacitors as the second power storage unit 42 . This makes it possible to set a voltage higher than twice the withstand voltage of one capacitor as the upper limit voltage of the current maintaining circuit 43 . Also, the second power storage unit 42 can input and output a voltage higher than twice the withstand voltage of one capacitor.

The power storage device 4 of the example shown in (E) of FIG. 9 further includes a parallel capacitor section 44 in addition to the example shown in (B) of FIG. 9 . Parallel capacitor section 44 is connected in parallel with first power storage section 41 . The parallel capacitor section 44 has one capacitor. This configuration is suitable when the withstand voltage of one capacitor is higher than that of the battery as first power storage unit 41 .
Capacitors can generally deliver power in a shorter period of time than a battery discharging the same power. The internal resistance of a capacitor is generally less than that of a battery. Capacitors also store power (charge) that is substantially proportional to the voltage. Capacitors can discharge power that is generally proportional to their voltage.
Therefore, voltage can be supplied from the first power storage unit 41 to the parallel capacitor unit 44 after the electric power of the first power storage unit 41 and the parallel capacitor unit 44 is consumed by starting the engine, for example. That is, the parallel capacitor section 44 can be charged with the power of the first power storage section 41 . Even if the first power storage unit 41 alone cannot supply the electric power required for starting in the next engine start, it is highly possible that the parallel capacitor unit 44 can supply the electric power required for starting.

In the power storage device 4 of the example shown in (F) of FIG. 9, a parallel capacitor section 44 is added to the example shown in (C) of FIG.
As in the example shown in FIG. 9F, the number of capacitors included in first power storage unit 41 may be different from the number of capacitors included in parallel capacitor unit 44 . The number of capacitors included in the first power storage unit 41 and the number of capacitors included in the parallel capacitor unit 44 are selected according to the upper limit voltage of the current maintaining circuit 43 and the maximum rated voltage of the battery as the first power storage unit 41. is possible. In the power storage device 4 of the example shown in FIG. 9F, the parallel capacitor section 44 includes four capacitors.

In the power storage device 4 of the example shown in (G) of FIG. 9, a parallel capacitor section 44 is added to the example shown in (D) of FIG. In the power storage device 4 of the example shown in FIG. 9G, the parallel capacitor section 44 includes three capacitors.

The number of batteries and the number of capacitors are not limited to those shown in FIGS. 9A to 9G.
For example, the parallel capacitor section 44 may include six capacitors for the power storage device 4 of the example shown in FIG. 7(G). It is easy to maintain the balance between the maximum rated voltage of the capacitor that constitutes first power storage unit 41 and that of the capacitor that constitutes parallel capacitor unit 44 .
Furthermore, in contrast to the power storage device 4, the first power storage unit 41 may include, for example, two sets of capacitors connected in parallel with each other. A set of capacitors is composed of, for example, three capacitors connected in series. In this case, the capacity of first power storage unit 41 increases. Further, for example, the parallel capacitor section 44 may further include six capacitors.
The capacitor included in parallel capacitor unit 44 and the capacitor included in second power storage unit 42 are of the same type. For example, capacitors having substantially the same maximum rated voltage and capacitance are of the same type. For example, capacitors with equal nominal values of voltage and capacitance are of the same type.
However, the capacitor included in parallel capacitor section 44 and the capacitor included in second power storage section 42 may be of different types.

FIG. 10 is a block diagram showing a variation of the electrical configuration of the straddle-type vehicle shown in FIG.
In the example shown in FIG. 10 , electric auxiliary machine L receives power supply from first power storage unit 41 without receiving power supply from second power storage unit 42 .
As a result, the electric power stored in the first power storage unit 41 can be intensively supplied by driving the permanent magnet motor generator 20 . For example, when starting the engine 10, the permanent magnet motor generator 20 can be driven for a longer period.
Further, a device having a rated voltage lower than the maximum total voltage of the first power storage unit 41 and the second power storage unit 42 can be provided as the electric auxiliary machine L or a part thereof.

The main relay 75a in the example shown in FIG. 10 is of a two-circuit type compatible with both the 18V system voltage and the 12V system voltage. However, the relay is not particularly limited, and may be, for example, two independent relays. In addition to the electric auxiliary machine L, for example, some circuits of the control device 60 are supplied with power from the first power storage unit 41 without being supplied with power from the second power storage unit 42, like the electric auxiliary machine L. may be configured to receive

Also, the straddle-type vehicle may include a starter motor different from the permanent magnet motor generator 20 . That is, the straddle-type vehicle may include the permanent magnet motor generator 20 and the starter motor. In this case, the starter motor is electrically provided at the position of the electric auxiliary machine L in the example of FIG. In this case, the starter motor receives power supply from the first power storage unit 41 via a switch that interlocks with the starter switch 6 . In this case, the permanent magnet type motor generator 20 assists the starter motor to start the engine. That is, at least part of the period during which the starter motor receives power to drive the crankshaft 15 overlaps at least part of the period during which the permanent magnet motor generator 20 receives power to drive the crankshaft 15 . .
That is, the starter motor is supplied with a voltage of 12 V, for example, from the first power storage unit 41 . Permanent magnet motor generator 20 is supplied with power from first power storage unit 41 and second power storage unit 42 that are connected in series. That is, the permanent magnet type motor generator 20 is supplied with a voltage higher than 12V, for example.

However, the power supply path of the starter motor in the variation of the straddle-type vehicle is not limited to the configuration described above. For example, the starter motor may be supplied with electric power from the first power storage unit 41 and the second power storage unit 42 that are connected in series, like the permanent magnet motor generator 20 .
Further, for example, by further providing a switching unit for the power supply path, for example, when the voltage of the first power storage unit 41 is higher than the reference, the starter motor receives power supply from the first power storage unit 41, and When the voltage of the first power storage unit 41 is lower than the reference, power may be supplied from the first power storage unit 41 and the second power storage unit 42 that are connected in series.

Reference Signs List 1 straddle-type vehicle 3a, 3b wheels 4 power storage device 41 first power storage unit 42 second power storage unit 43 current maintenance circuit 10 engine 15 crankshaft 20 permanent magnet motor generator 21 inverter

Claims (8)

A straddle-type vehicle,
The straddle-type vehicle
wheels and
an engine having a crankshaft for outputting torque from the crankshaft for driving the wheels generated by combustion operation;
a permanent magnet motor generator provided at one end of the crankshaft, having a permanent magnet, starting or assisting the engine by rotating the crankshaft, and generating power by being driven by the engine;
a first power storage unit that is a battery that has a maximum rated voltage of 12 V or more and stores electric power;
a second power storage unit always connected in series with the first power storage unit with respect to the permanent magnet motor generator and having a maximum charge rate higher than twice the maximum charge rate of the first power storage unit;
a plurality of switching units that are electrically connected to the second power storage unit always connected in series with the first power storage unit and the permanent magnet motor-generator, and that control current output from the permanent magnet motor-generator; an inverter equipped with
When the engine is started or assisted, a current is output from the first power storage unit and the second power storage unit connected in series to the permanent magnet motor generator via the inverter, and a deceleration is performed at one end of the crankshaft. While the inverter is charging at least the first power storage unit by generating power from the permanent magnet motor-generator provided without an intermediary, the second power storage unit is electrically disconnected without electrically disconnecting the second power storage unit. a current maintaining circuit that maintains a state in which the charging current flows to the first power storage unit while causing a voltage drop so that the voltage applied to the power storage unit does not exceed the upper limit voltage set for the second power storage unit;
Prepare. 2. The straddle-type vehicle according to claim 1, wherein an upper limit voltage of said second power storage unit is lower than a maximum rated voltage of said first power storage unit. The straddle-type vehicle according to claim 1 or 2,
While the inverter charges at least the first power storage unit, a second voltage, which is the voltage applied to the second power storage unit, is lower than the first voltage applied to the first power storage unit. A straddle-type vehicle according to any one of claims 1 to 3,
The straddle-type vehicle includes a capacitor connected in parallel with the first power storage unit, which is a battery. A straddle-type vehicle according to any one of claims 1 to 4,
A permanent magnet type motor generator includes a rotor having a plurality of magnetic pole portions made up of the permanent magnets;
a stator core having a plurality of teeth formed with a plurality of slots spaced apart in the circumferential direction of the permanent magnet motor generator; and a stator having a winding provided to pass through the slots,
The number of the magnetic pole portions is greater than the number of the plurality of teeth.
A straddle-type vehicle according to any one of claims 1 to 4,
A permanent magnet type motor generator includes a rotor having a plurality of magnetic pole portions composed of the permanent magnets and connected to one end of a crankshaft without a reduction gear;
a stator having a stator core having a plurality of slots spaced apart in the circumferential direction of the motor generator and a stator winding provided to pass through the slots;
a plurality of detected parts provided on the rotor at intervals in the circumferential direction;
a rotor position detection device having detection windings provided at positions facing the plurality of detected portions and provided separately from the stator windings;
Prepare.

A straddle-type vehicle according to any one of claims 1 to 6,
The engine further comprises a crankcase configured to be internally lubricated with oil,
The permanent magnet type motor generator is provided at a position in contact with the oil. A straddle-type vehicle according to any one of claims 1 to 7,
The inverter supplies electric power from the first power storage unit and the second power storage unit to the permanent magnet motor generator while the straddle-type vehicle is running, and assists the permanent magnet motor generator in rotating the crankshaft. do.

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