JP7391107B2 - straddle vehicle - Google Patents

Description

The present invention relates to a straddle-type vehicle.

For example, Patent Document 1 discloses a straddle-type vehicle. The straddle-type vehicle disclosed in Patent Document 1 is a motorcycle equipped with an engine start control device. The straddle-type vehicle disclosed in Patent Document 1 includes an engine and an alternating current generator starter (ACG starter). The ACG starter is a permanent magnet generator. The ACG starter is provided at one end of the engine crankshaft. That is, the rotor of the ACG starter is fixed to the crankshaft. The engine is started by driving the ACG starter. When starting the engine, a voltage of 48V is supplied to the ACG starter.

International Publication No. 2018/180650

A straddle-type vehicle is configured such that the posture of the vehicle is controlled by the weight shift of the driver during driving. Therefore, from the viewpoint of operability and running performance, straddle-type vehicles are required to have a compact body.
For example, as shown in Patent Document 1, an ACG starter of a straddle-type vehicle is connected to a crankshaft without using a speed reduction device such as a gear or a 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 can be made more compact.

An ACG starter provided on the crankshaft without a reduction gear is required to output a larger torque when driving the crankshaft than when connected to the crankshaft via a reduction gear.
Straddle-type vehicles are required to have a compact vehicle body while increasing the torque output from a permanent magnet generator provided on the crankshaft without a reduction gear.

SUMMARY OF THE INVENTION An object of the present invention is to provide a straddle-type vehicle that can increase the torque output by a permanent magnet generator provided on a crankshaft without using a speed reducer, while making the vehicle body more compact.

For example, in the straddle-type vehicle disclosed in Patent Document 1, the ACG starter is driven with a high voltage of 48V. As a result, the ACG starter of Patent Document 1 is capable of outputting a larger torque than, for example, a case where the ACG starter is driven by a 12V voltage that has been used in existing straddle-type vehicles.
In addition to the ACG starter, the straddle-type vehicle is equipped with an electric auxiliary machine. Electric auxiliary equipment used in existing straddle-type vehicles and supplied with a 12V system voltage generally cannot be driven at a 48V system high voltage.
For example, in order to operate such an existing electric auxiliary machine, the straddle-type vehicle disclosed in Patent Document 1 is required to have a 12V power source for the electric auxiliary machine, in addition to the 48V power supply. The saddle type vehicle disclosed in Patent Document 1 is equipped with both a 48V battery and a 12V battery.
As a result, a straddle-type vehicle as shown in Patent Document 1 has both a 48V battery and a 12V battery, and a 48V By installing a voltage converter between the system and the 12V system, the size becomes larger. In other words, the car body cannot be made more compact.

The present inventor has developed an electric auxiliary machine for a straddle-type vehicle that can be driven in order to increase the torque output by a permanent magnet generator installed on the crankshaft without using a speed reducer and to make the vehicle body more compact. I paid attention to the voltage level.
Many of the electric auxiliary machines used in straddle-type vehicles have a nominal voltage of 12V. However, the inventor's investigation has revealed that most of the maximum operating voltages of electric auxiliary equipment for straddle-type vehicles, which have a nominal voltage of 12V, have a voltage margin greater than 60% with respect to the operating voltage. Do you get it. That is, most electric accessories with a nominal voltage of 12V cannot operate at 48V or 24V, for example, but can operate at 15V or more and less than 19V.

Therefore, the inventor considered the following.
When the permanent magnet generator installed at one end of the crankshaft generates electricity, an inverter electrically connected to the permanent magnet generator and the power storage device supplies the power storage device with a 18V grid voltage of 15V or more and less than 19V. While applying the 18V system voltage to charge the power storage device, the 18V system voltage is applied to the electric auxiliary machine to operate the electric auxiliary machine.

The voltage for charging the power storage device is a 18V system voltage of 15V or more and less than 19V. That is, the 18V system voltage for charging the power storage device is higher than 12V.
When starting or assisting the engine, the permanent magnet generator can receive a supply of 18V grid voltage, which is higher than 12V, from the power storage device. Therefore, a permanent magnet generator can output a larger torque than a 12V generator.

By operating the electric auxiliary equipment at the 18V system voltage while charging the power storage device at the 18V system voltage, the power storage device corresponding to the 12V system voltage can be omitted. Therefore, the body of the straddle-type vehicle can be made compact.
Therefore, the vehicle body can be made more compact while increasing the torque output by the permanent magnet generator provided on the crankshaft without a reduction gear.

A straddle-type vehicle according to each aspect of the present invention, which was completed based on the above findings, has the following configuration.

(1) A straddle-type vehicle,
The straddle-type vehicle is
wheels and
an engine that has a crankshaft and outputs torque for driving the wheels generated by a combustion operation from the crankshaft;
A 12V electric auxiliary machine that has a nominal operating voltage of 12V and operates upon receiving electric power;
a permanent magnet generator that is provided at one end of the crankshaft, has a permanent magnet, starts or assists the engine by rotating the crankshaft, and generates electricity by being driven by the engine;
A power storage device that stores electricity;
an inverter that is electrically connected to the permanent magnet generator and the power storage device and includes a plurality of switching units that control the current output from the permanent magnet generator,
The inverter applies a 18V system voltage of 15V or more and less than 19V, which is generated by the permanent magnet generator provided at one end of the crankshaft without a reduction gear, to the power storage device to control the power storage device. While charging, the 18V system voltage is applied to the 12V system electric auxiliary machine to operate the electric auxiliary machine.

When the permanent magnet generator of the saddle type vehicle in the above configuration generates electricity, the inverter electrically connected to the permanent magnet generator and the power storage device applies a 18V system voltage of 15V or more and less than 19V to the power storage device. While charging the power storage device, the 18V system voltage is applied to the 12V electric auxiliary machine to operate the 12V electric auxiliary machine.
The voltage for charging the power storage device is a 18V system voltage of 15V or more and less than 19V. That is, the 18V system voltage for charging the power storage device is higher than 12V. In this case, a power storage device compatible with 18V system voltage can be employed.
When starting or assisting the engine, the permanent magnet generator can be driven with a 18V grid voltage greater than 12V. Therefore, the permanent magnet generator provided at one end of the crankshaft can output a larger torque than in the case of 12V supply.
Since the 12V system electric auxiliary equipment operates at the 18V system voltage while the power storage device charges at the 18V system voltage, the power storage device corresponding to the 12V system voltage and the converter that converts the voltage between the two systems can be omitted. Therefore, the body of a straddle-type vehicle having a permanent magnet generator provided at one end of the crankshaft can be made compact.
As described above, according to configuration (1), the vehicle body can be made more compact while increasing the torque output by the permanent magnet generator provided on the crankshaft without using a speed reducer.

(2) The straddle-type vehicle according to (1),
The 12V electric auxiliary machine is an engine auxiliary machine that operates to cause the engine to perform combustion.

According to the straddle-type vehicle having the above configuration, the engine auxiliary equipment operates at a system voltage of 18V. Engine auxiliary equipment exhibits capabilities according to the voltage supplied. Therefore, according to the straddle-type vehicle having the above configuration, the combustion operation capability of the engine is improved compared to a case where the engine operates at 12V, for example.

(3) The straddle-type vehicle according to (2),
The engine auxiliary equipment includes an injection device that injects fuel toward or inside the engine, and an ignition device that ignites the fuel inside the engine.

According to the straddle-type vehicle having the above configuration, the injection device and the ignition device operate at a system voltage of 18V. For example, the higher the voltage supplied to an ignition device, the more likely it is to produce a strong ignition spark. Furthermore, the higher the voltage supplied to the injection device, the greater the magnetic force acting on the built-in solenoid. Therefore, injection can be easily controlled. Therefore, according to the saddle type vehicle having the above configuration, the fuel injection and ignition capabilities are improved compared to a case where the vehicle operates at 12V, for example.

(4) A straddle-type vehicle according to any one of (1) to (3),
The permanent magnet generator includes a rotor that has a plurality of magnetic pole parts made of the permanent magnets and is connected to one end of the crankshaft without a reduction gear;
A stator core in which a plurality of slots are formed at intervals in a circumferential direction of the permanent magnet generator, and a stator having a winding provided to pass through the slots,
The number of the magnetic pole parts 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 rotational speed of the rotor is greater than when the number of magnetic pole portions is smaller than the number of teeth.
The angular velocity is the angular velocity in terms of electrical angles based on the repetition period of the magnetic poles. When the angular velocity is high, the inductance of the winding is high. Moreover, the angular velocity further increases as the rotational speed of the rotor increases. The inductance of the winding impedes the flow of current through the winding. Therefore, although the induced electromotive voltage increases as the rotational speed of the rotor increases, the large inductance of the winding suppresses an excessive increase in the current output from the generator.
Therefore, according to the saddle type vehicle having the above configuration, the power storage device can be charged to a higher rotational speed of the crankshaft than when the number of magnetic pole portions is smaller than the number of teeth. Therefore, wasteful consumption of power can be suppressed.

(5) A straddle-type vehicle according to any one of (1) to (3),
The permanent magnet generator includes a rotor that has a plurality of magnetic pole parts made of the permanent magnets and is connected to one end of the crankshaft without a reduction gear;
a stator having a stator core in which a plurality of slots are formed at intervals in a 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 a detection winding provided at a position facing the plurality of detected parts and provided separately from the stator winding;
Equipped with

The rotor is connected to one end of the crankshaft without a reduction gear. Therefore, the rotor position detection device can accurately detect the rotational position of the rotor and the rotational position of the crankshaft.
A rotor position detection device having a detection winding provided separately from the stator winding has better heat resistance than, for example, a Hall IC. Further, since a rotor position detection device having a detection winding electromagnetically detects a detected portion different from a permanent magnet, the rotor position detection device has a higher degree of freedom in arrangement than, for example, a Hall IC. Therefore, the engine can be downsized while allowing precise control of the engine and permanent magnet generator.

(6) A straddle-type vehicle according to any one of (1) to (5),
The engine further includes a crankcase configured to be internally lubricated with oil;
The permanent magnet generator is provided at a position where it comes into contact with the oil.

According to the straddle-type vehicle having the above configuration, the power storage device can be charged without wasting power in a range up to a high rotational speed of the crankshaft compared to, for example, a case using a 12V system voltage. Therefore, in such a permanent magnet generator, the temperature of the stator winding does not or cannot easily rise above the oil temperature, so even if the permanent magnet generator is placed in contact with the oil, the temperature of the stator winding does not become higher than the oil temperature. Evaporation can be suppressed.
For example, when a permanent magnet generator is placed in an environment where it comes into contact with oil, it is usually necessary to increase the size of the oil cooling mechanism. However, according to the straddle-type vehicle having the above configuration, it is possible to suppress or avoid increasing the size of the cooling mechanism. Therefore, the vehicle body can be made more compact.

(7) A straddle-type vehicle according to any one of (1) to (6),
The inverter supplies electric power from the power storage device to the permanent magnet generator while the straddle-type vehicle is running, and causes the permanent magnet generator to assist rotation of the crankshaft.

According to the straddle-type vehicle having the above configuration, the permanent magnet generator can be driven with a system voltage of 18V, which is higher than 12V, while the straddle-type vehicle is running. Therefore, the crankshaft can be driven to a higher rotational speed than, for example, when driven at 12V. Therefore, compared to the case of driving with 12V, for example, acceleration by the engine can be assisted up to a higher rotational speed. Furthermore, the vehicle body can be made more compact than, for example, when a power storage device other than a 12V power storage device is provided.

(8) A straddle-type vehicle according to any one of (1) to (7),
The power storage device includes a plurality of power storage units that are always electrically connected to each other in series and each of which stores power.

According to the saddle type vehicle having the above configuration, the configuration of the power storage device for receiving the supply of 18V system voltage can be easily adjusted by the number of power storage units connected in series. The power storage device can be configured with a compact number of power storage units while being compatible with the 18V system voltage.

(9) A straddle-type vehicle according to any one of (1) to (8),
The 12V nominal operating voltage of the 12V electric auxiliary machine is determined by the display regarding the 12V electric auxiliary machine, the structure and material of the 12V electric auxiliary machine, and the operation and/or function of the 12V electric auxiliary machine. identified by at least one element selected from the group consisting of:

According to the above configuration, it is possible to accurately and easily determine whether or not a 12V system electric auxiliary machine in general is to be supplied with an 18V system voltage in a straddle type vehicle.

Permanent magnet generators have permanent magnets. For example, a configuration in which the rotor is provided with a coil instead of a permanent magnet is different from the permanent magnet generator in this configuration. Permanent magnet generators are not included in 12V electric auxiliary equipment.
A permanent magnet generator does not require a field coil or a slip ring, so it can be made smaller than, for example, an alternator that has a field coil in its rotor.

A permanent magnet generator generates electricity by starting an engine and being driven by the engine, for example. However, the permanent magnet generator is not particularly limited, and may, for example, assist the started engine without starting the engine. When the permanent magnet generator starts the engine and generates electricity by being driven by the engine, the crankshaft can be driven with a large torque by the 18V system voltage at the time of starting the engine.

A permanent magnet generator includes, for example, an outer rotor and an inner rotor. When equipped with an outer rotor, it is easy to arrange the detected portion of the rotor on a long circumference. In this case, it is easy to detect the rotational positions of the outer rotor and the crankshaft with high accuracy. Further, it is easy to downsize while maintaining the inertia of the rotor. However, the permanent magnet generator is not particularly limited, and may include an inner rotor and an outer rotor, for example. Further, the permanent magnet type generator may be an axial type in which the teeth of the stator and the magnets of the rotor face each other in the axial direction.

The 12V electric auxiliary machine is an electric device related to the operation of a straddle-type vehicle. The 12V electric auxiliary equipment is, for example, an injection device and an ignition device. The 12V electric auxiliary machine is not limited to this, and may be, for example, a fuel pump or a cooling fan.
Engine auxiliary equipment is equipment that directly contributes to the combustion operation of the engine. Engine auxiliary equipment is, for example, an injection device and an ignition device.

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

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

A straddle-type vehicle has an engine and wheels as driving wheels. The wheels of the straddle-type vehicle receive mechanically transmitted torque output from the crankshaft of the engine to drive the straddle-type vehicle. For example, a type of vehicle in which engine torque is not mechanically transmitted to the wheels is not included in the straddle-type vehicle of the present invention. For example, neither so-called pure electric vehicles nor series electric vehicles are included in the straddle-type vehicle of the present invention.

A 12V electric auxiliary machine is a device that is mounted on a straddle-type vehicle and operates by receiving power supply. The 12V electric auxiliary equipment is, for example, a fuel pump, a fuel injector, an ignition device, an engine starting motor, a lamp, or a combination thereof.

The ignition device includes, for example, an injection coil.

The nominal operating voltage is the "standard voltage of the system" (Japanese Industrial Standard (JIS) C4605). In other words, the nominal operating voltage is a voltage that represents the operating voltage of the 12V electric auxiliary machine. Therefore, the nominal operating voltage is a voltage at which the 12V electric auxiliary machine can operate. In a straddle-type vehicle, the voltage supplied to the 12V electric auxiliary equipment may vary. Note that the nominal operating voltage is also simply referred to as nominal voltage.

The nominal operating voltage of the 12V electric auxiliary equipment is lower than the rated voltage. The rated voltage is sometimes referred to as the maximum rated voltage.

The nominal operating voltage is the "voltage for designing equipment" (JIS C0366). In other words, the nominal operating voltage is a representative value set to express the characteristics of the 12V electric auxiliary machine. The nominal operating voltage is also the "nominal voltage applied to electrical components" (JIS D5005).

In general, the nominal operating voltage of 12V electric auxiliary equipment installed in straddle-type vehicles that mechanically transmit engine power to the wheels is 6V, 12V, or 24V (JIS D5005 ).
This corresponds to the fact that the nominal operating voltage of the battery mounted on the saddle type vehicle is 6V, 12V, or 24V.

The 12V nominal operating voltage of the 12V electric auxiliary machine is determined by the display regarding the 12V electric auxiliary machine, the structure and material of the 12V electric auxiliary machine, and the operation and/or function of the 12V electric auxiliary machine. identified by at least one element selected from the group consisting of: The display regarding the 12V electric auxiliary equipment shall be made, for example, on the 12V electric auxiliary equipment itself, the packaging container of the 12V electric auxiliary equipment, the instruction manual of the 12V electric auxiliary equipment, or the specifications of the 12V electric auxiliary equipment. be exposed. When "12V" is written as an indication regarding the 12V electric auxiliary machine, the 12V electric auxiliary machine is specified as having a nominal operating voltage of 12V.

In addition, if the specifications or instruction manual of the saddle type vehicle indicates the nominal operating voltage of the power storage device that is connected to the 12V electric auxiliary equipment without going through a voltage converter, that value should be It can be said to be the nominal operating voltage of the machine. For example, a 12V electric auxiliary machine operated by a battery having a nominal operating voltage of 12V has a nominal operating voltage of 12V. These displays are also examples of displays related to the 12V electric auxiliary machine.

Furthermore, if the nominal operating voltage is indicated in the specifications or instruction manual of the power storage device that is connected to the 12V electric auxiliary equipment without going through a voltage converter, that value is the nominal operating voltage of the 12V electric auxiliary equipment. It can be said that. This display is also an example of a display regarding the 12V electric auxiliary machine. Here, the nominal operating voltage of the power storage device is "a value determined as a guideline for the voltage between terminals obtained when the battery is used under normal conditions." (Wikipedia (https://ja.wikipedia .org/wiki/%E5%85%AC%E7%A7%B0%E9%9B%BB%E5%9C%A7))

Further, the 12V nominal operating voltage of the 12V electric auxiliary machine can also be specified by the structure and material of the 12V electric auxiliary machine. For example, if 12V electric auxiliary machine A has the same material and structure as 12V electric auxiliary machine B, which has a nominal operating voltage of 12V, regardless of the display regarding 12V electric auxiliary machine A, 12V electric auxiliary machine A may be specified as having a nominal operating voltage of 12V. In this case, the 12V electric auxiliary machine A has the same appearance as the 12V electric auxiliary machine B, for example, except for the "indication regarding the 12V electric auxiliary machine." Further, the 12V nominal operating voltage of the 12V electric auxiliary machine can also be specified by the operation and/or function of the 12V electric auxiliary machine. For example, if 12V electric auxiliary machine A achieves the same operation and/or function under the same conditions as 12V electric auxiliary machine B, which has a nominal operating voltage of 12V, the display regarding 12V electric auxiliary machine A, or Regardless of the structure and material, the 12V electric auxiliary machine A can be specified to have a nominal operating voltage of 12V. The sameness of operation and function here is evaluated not only qualitatively but also quantitatively. Quantitative identity is not limited to the same, and may be substantially the same. Substantive here is a concept that allows for tolerances during design and/or errors during manufacturing. In addition, the concept is to allow a difference of ±10% in parameters related to the operation and function of a 12V electric auxiliary machine, more preferably ±8%, still more preferably ±5%, Particularly preferred is ±3%. Note that there is no need to strictly distinguish between operation and function. For example, the identity of the operation and/or function of a fuel pump may be specified by the operation of moving parts within the fuel pump, or may be specified by the amount of liquid pumped (ie, function).

The power storage device includes, for example, a battery and a capacitor connected in series to the battery. The battery is, for example, a lead battery. The capacitor is, for example, an electric double layer capacitor (EDLC). For example, when the voltage of the capacitor exceeds the upper limit voltage set for the capacitor, the power storage device suppresses the current input to the capacitor without electrically disconnecting the capacitor, and reduces the current input to the power storage device. It may also include a circuit that supplies the battery.
However, the power storage device is not particularly limited. For example, a power storage device may not have a circuit that supplies current to a battery instead of a capacitor. The capacitor may also be, for example, a lithium ion capacitor, an electrolytic capacitor, or a tantalum capacitor. Further, the battery may be, for example, a lithium ion battery or a nickel metal hydride battery. Further, the power storage device may be configured with a battery without a capacitor.

The terminal voltage of the capacitor changes depending on the power stored in the capacitor. For example, the capacitor is connected to the 18V grid voltage even if the terminal voltage of the capacitor drops significantly below 18V as a result of a reduction in the power of the capacitor connected to the 18V grid voltage.

The terminology used herein is for the purpose of defining particular embodiments only and is not intended to limit the invention.
The term "and/or" as used herein includes any or all combinations of one or more of the associated listed components.
As used herein, the use of the terms "including,""comprising," or "having," and variations thereof, refer to the described features, steps, operations, Although identifying the presence of elements, ingredients, and/or equivalents thereof, may include one or more of steps, acts, elements, components, and/or groupings thereof.
As used herein, the terms "attached,""coupled," and/or their equivalents are used broadly to refer to both direct and indirect attachment, and coupling, unless otherwise specified. includes.
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 should be construed to have meanings consistent with the relevant art and their meanings in the context of this disclosure, and are not explicitly defined herein. should not be construed in an ideal or overly formal sense unless otherwise specified.
It is understood that in the description of the invention, techniques and numerous steps are disclosed.
Each of these has individual benefits, and each can also be used with one or more, or in some cases 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.
In this specification, a new straddle-type vehicle will be described.
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 apparent to one skilled in the art that the invention may be practiced without these specific details.
This disclosure is to be considered as illustrative of the invention and is not intended to limit the invention to the particular embodiments illustrated in the drawings or description below.

According to the present invention, it is possible to realize a straddle-type vehicle whose body 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. 2 is a graph showing input and output voltages of the inverter 21 shown in FIG. 1. FIG. 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. FIG. 4 is a partial cross-sectional view schematically showing a schematic configuration of the engine unit shown in FIG. 3. FIG. 5 is a sectional view showing a cross section perpendicular to the rotational axis of the permanent magnet generator shown in FIG. 4. FIG. 2 is a diagram showing an example of a variation of the power storage device shown in FIG. 1. FIG.

The present invention will be described below based on embodiments with reference to the drawings.

FIG. 1 is a diagram schematically showing a straddle-type vehicle according to an embodiment of the present invention. Part (a) of FIG. 1 is a side view of the 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).

The straddle-type vehicle 1 shown in FIG. 1 includes wheels 3a and 3b, an engine 10, a 12V electric auxiliary machine L, a power storage device 4, a permanent magnet generator 20, and an inverter 21.
Further, the straddle-type vehicle 1 includes a vehicle body 2 . FIG. 1 shows a lean vehicle as an example of a saddle-ride type vehicle 1. As shown in FIG. A lean vehicle leans to the left during a left turn, and leans to the right when turning to the right.

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

The 12V electric auxiliary machine L is an electric device mounted on the straddle-type vehicle 1. The 12V electric auxiliary machine L operates upon being supplied with electric power.
The 12V electric auxiliary machine L is, for example, an engine auxiliary machine that operates to cause the engine 10 to perform combustion. The engine auxiliary equipment includes, for example, a fuel injection device 18 and an ignition device 19 (see FIG. 4). The fuel injection device 18 injects fuel toward or within the engine 10 . Ignition device 19 ignites fuel inside engine 10 .

Permanent magnet generator 20 is provided at one end of crankshaft 15 . The permanent magnet generator 20 is provided at one end of the crankshaft 15 without a reduction gear.
The permanent magnet generator 20 has a permanent magnet. More specifically, the permanent magnet generator 20 includes a permanent magnet section 37 made of permanent magnets.
The permanent magnet generator 20 also serves as a starter for starting the engine 10. The permanent magnet generator 20 is a permanent magnet starter generator. Permanent magnet generator 20 starts engine 10 by rotating crankshaft 15 . The permanent magnet generator 20 also generates electricity by being driven by the engine 10.

The power storage device 4 is a device that can charge and discharge electricity. Power storage device 4 stores electric power.
Power storage device 4 outputs the charged power to the outside. Power storage device 4 supplies electric power to permanent magnet generator 20 . Power storage device 4 supplies power to permanent magnet generator 20 when 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 generator 20. Power storage device 4 has a capacitance that can be charged with enough power to start engine 10 at least once.

Power storage device 4 operates at 18V system voltage. The power storage device 4 can be charged with a 18V system voltage. Moreover, the power storage device 4 in a charged state can output a 18V system voltage.
Power storage device 4 includes, for example, a battery. The power storage device 4 includes, for example, a plurality of power storage units that are always electrically connected in series and each stores power. Power storage device 4 is, for example, a combination of a plurality of batteries. As the configuration of power storage device 4, for example, a combination of a battery and a capacitor can be employed. That is, examples of the power storage unit include a battery and a capacitor.

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

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 section 211 of inverter 21 . Control device 60 controls the current flowing between permanent magnet generator 20 and power storage device 4 by controlling the operation of switching unit 211 of inverter 21 . Further, the control device 60 controls the operation of the permanent magnet generator 20. The control device 60 controls the voltage output from the inverter 21 using, for example, a phase control method or vector control.
For example, control device 60 causes inverter 21 to supply current from power storage device 4 to permanent magnet generator 20 in response to a signal from starter switch 6 . As a result, power is supplied from the power storage device 4 to the permanent magnet generator 20, and the engine 10 is started. After starting the engine 10, that is, after starting the combustion operation, the control device 60 controls the inverter 21 to cause the current from the permanent magnet generator 20 to flow to the power storage device 4. As a result, the power storage device 4 is charged by the power generated by the permanent magnet generator 20.
Further, even after the engine 10 is started, that is, after the combustion operation has started, the control device 60 permanently supplies the electric power of the power storage device 4 to the inverter 21 in response to the operation of the acceleration instruction section 8 (see part (b) of FIG. 3). It can be supplied to the magnetic generator 20. More specifically, while the straddle-type vehicle 1 is running, the control device 60 supplies electric power from the power storage device 4 to the permanent magnet generator 20 to assist the permanent magnet generator 20 in rotating the crankshaft 15. let Thereby, the acceleration of the straddle-type vehicle 1 by the engine 10 is assisted by the permanent magnet generator 20.

The control device 60 also has the function of an engine control section that controls fuel supply and combustion to the engine 10. The control device 60 controls the combustion of the engine 10 by controlling the operation of a 12V 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 in engine 10 by executing a program stored in memory.
Control device 60 operates using power from 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 so that it can be applied to control device 60 . The down converter is provided in the inverter 21, for example. For example, when power storage device 4 includes a battery and a capacitor, control device 60 may operate with an operating voltage that is down-converted from the battery voltage.

FIG. 2 is a graph showing input and output voltages of the inverter 21 shown in FIG.
The horizontal axis of the graph shown in FIG. 2 indicates the rotational speed of the crankshaft 15. The horizontal axis of the graph indicates the voltage that the inverter 21 outputs to the power storage device 4 and the 12V electric auxiliary machine L, and the voltage that the permanent magnet generator 20 supplies to the inverter 21. Also shown in the graph of FIG. 2 is a conventional 12V voltage level.
When the permanent magnet generator 20 generates electricity, the inverter 21 applies the 18V grid voltage to the power storage device 4 to charge the power storage device 4, as shown in the “power generation area” in FIG. The voltage is applied to the 12V electric auxiliary machine L to operate the 12V electric auxiliary machine.
The 18V grid voltage is a voltage in a range that includes 18V. The 18V system voltage is a voltage of 15V or more and less than 19V. Therefore, the 18V system voltage is different from either the 6V system voltage or the 12V system voltage used in conventional straddle-type vehicles. The 18V system voltage is also different from the 24V system voltage used in some straddle-type vehicles. Whether or not the inverter 21 outputs a voltage of 15V or more and less than 19V is measured at the output terminal of the inverter 21.

Further, when starting the engine 10, the inverter 21 receives a supply of 18V system voltage from the power storage device 4, as shown in the "starting region" in FIG. Permanent magnet generator 20 is driven by 18V grid voltage. More specifically, the inverter 21 supplies the permanent magnet generator 20 with a voltage waveform based on the 18V system voltage. For example, the permanent magnet generator 20 receives a voltage waveform having an amplitude of 18V that is PWM-modulated by the switching unit 211 of the inverter 21 .

The 18V system voltage for charging the power storage device 4 is higher than 12V. Therefore, as the power storage device 4, a power storage device 4 compatible with 18V system voltage can be adopted.
For example, when the rotational speed of the crankshaft 15 increases, such as during acceleration of the straddle-type vehicle 1, when the rotational speed exceeds the upper limit rotational speed at which the inverter 21 cannot control the output voltage within the target range, the inverter 21 Stop operation. For example, inverter 21 controls switching unit 211 so that the voltage applied to power storage device 4 and switching unit 211 itself does not rise excessively. For example, the inverter 21 controls the switching unit 211 to short-circuit the stator winding W of the permanent magnet generator 20. As a result, the electric power generated by the permanent magnet generator 20 is consumed by the stator winding W as heat.

Since the power storage device 4 of this embodiment is compatible with a 18V system voltage, the power storage device 4 can be charged to a higher rotational speed N1 than in the case of a conventional 12V system voltage. That is, the upper limit rotational speed of the crankshaft 15 that can charge the power storage device 4 can be set to a higher value than in the case of a 12V system voltage that has been generally employed in the past. In other words, the amount of power wasted without charging can be reduced.

Further, when starting the engine 10, the permanent magnet generator 20 can be driven with a system voltage of 18V, which is higher than the 12V that is generally employed in the past. Therefore, the permanent magnet type generator 20 can output a larger torque than in the case of 12V. Therefore, deterioration in the performance of the permanent magnet generator 20 is suppressed.

Further, since the 12V system electric auxiliary machine L operates at the 18V system voltage, a decrease in the performance of the 12V system electric auxiliary machine L is suppressed. The fuel injection device 18 (see FIG. 4), which is an example of the 12V electric auxiliary equipment L, has injection or injection stoppage controlled by the operation of a built-in solenoid. The higher the voltage supplied, the greater the magnetic force acting on the built-in solenoid. Therefore, injection can be easily controlled.
Further, the ignition device 19 (see FIG. 4), which is an example of the 12V electric auxiliary equipment L, generates electric sparks by boosting the supplied voltage at a predetermined ratio. The higher the voltage supplied, the more likely it is to generate an electrical spark.
Many of the 12V electric auxiliary machines L that have a nominal operating voltage of 12V have difficulty operating at a voltage of 24V and its fluctuation margin due to insulation performance. However, most of the 12V electric auxiliary machines L having a nominal operating voltage of 12V can be operated at an 18V system voltage.

In the saddle type vehicle 1, installation of a power storage device corresponding to the 12V system voltage can be omitted. That is, there is no need to install a plurality of power storage devices corresponding to different voltages depending on the performance of the permanent magnet generator 20 and the performance of the 12V electric auxiliary machine L. Therefore, the body of the straddle-type vehicle 1 can be made compact.

In this way, according to the straddle-type vehicle 1, the vehicle body can be made more compact while increasing the torque output by the permanent magnet generator 20 provided on the crankshaft 15 without a reduction gear.

[Application example]
Next, an application example of the embodiment will be described with reference to FIG. 3.

FIG. 3 is a diagram schematically showing a straddle-type vehicle 1 and an electrical system, which are an application example of the embodiment shown in FIG. Part (a) of FIG. 3 is a plan view of the straddle-type vehicle 1. FIG. Part (b) of FIG. 3 is a side view of the straddle-type vehicle 1. FIG. Part (c) of FIG. 3 is an actual wiring diagram schematically showing the connection of the electrical system of the straddle-type vehicle 1. As shown in FIG.
In the application examples shown in FIG. 3 and subsequent figures, elements corresponding to the embodiment shown in FIG. 1 will be described with the same reference numerals as in FIG. 1.

A straddle-type vehicle 1 shown in FIG. 3 includes a vehicle body 2. As shown in FIG. The vehicle body 2 is provided with a seat 2a for a driver to sit on. The driver sits astride the seat 2a. FIG. 3 shows a motorcycle as an example of the straddle-type vehicle 1. As shown in FIG.

The straddle-type vehicle 1 includes 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 without contacting 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 generator 20.
Engine 10 outputs power via crankshaft 15 . Engine 10 outputs torque for driving wheels 3b from crankshaft 15. 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 a displacement of less than 400 mL, for example.
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.

The permanent magnet generator 20 is driven by the engine 10 to generate electricity. The permanent magnet generator 20 shown in FIG. 3 is a magnet starter generator.
The permanent magnet generator 20 includes a rotor 30 and a stator 40 (see FIG. 4). The rotor 30 includes a permanent magnet section 37 made of a permanent magnet. The rotor 30 rotates with 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. Power storage device 4 outputs the charged power to the outside. The power storage device 4 supplies electric power to the permanent magnet generator 20 and the 12V electric auxiliary machine L. Power storage device 4 supplies power to permanent magnet generator 20 when engine 10 is started. Further, the power storage device 4 is charged with electric power generated by the permanent magnet generator 20.

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

Permanent magnet generator 20 rotates crankshaft 15 using electric power from power storage device 4 . This causes the permanent magnet generator 20 to start the engine 10.

The saddle type vehicle 1 includes a main switch 5. The main switch 5 is a switch for supplying electric power to a 12V electric auxiliary machine L (see part (c) of FIG. 3) provided in the straddle-type vehicle 1 according to its operation. The 12V electric auxiliary machine L is a comprehensive representation of devices that operate while consuming electric power, excluding the permanent magnet generator 20. The 12V electric auxiliary machine L includes, for example, a headlamp 9, a fuel injection device 18, and an ignition device 19.
The saddle type vehicle 1 includes a starter switch 6. The starter switch 6 is a switch for starting the engine 10 in response to an operation. The saddle type vehicle 1 includes a main relay 75. The main relay 75 opens and closes a circuit including the 12V electric auxiliary machine L according to a signal from the main switch 5.
The straddle-type vehicle 1 includes an acceleration instruction section 8 . The acceleration instruction section 8 is an operator for instructing acceleration of the straddle-type vehicle 1 in response to an operation. Specifically, the acceleration instruction section 8 is an accelerator grip.

Power storage device 4 includes, for example, a battery that operates at 12V and a capacitor connected in series to the battery. The battery is, for example, a lead battery. The capacitor is, for example, an electric double layer capacitor (EDLC).
Furthermore, the power storage device 4 has a circuit that supplies the current that is input to the power storage device 4 when the voltage of the capacitor exceeds 6 V to the battery instead of the capacitor.

In the configuration shown in FIG. 3, power storage device 4 supplies electric power to permanent magnet generator 20 when engine 10 is started. A permanent magnet generator 20 can be driven with 18V grid voltage. Therefore, the permanent magnet generator 20 can output a larger torque than, for example, a 12V case.

As shown in part (c) of FIG. 3, the permanent magnet generator 20, the power storage device 4, the main relay 75, the inverter 21, and the 12V electric auxiliary machine L are electrically connected by a wiring J. For ease of viewing the symbols, the wiring symbol (J) is attached to a part of the wiring shown in part (c) of FIG. 3.
The wiring J is composed of, for example, a lead wire. The wiring J may be composed of a plurality of lead wires connected together. Further, the wiring J may include a connector for relaying lead wires, a fuse, and a connection terminal. Illustrations of connectors, fuses, and connection terminals are omitted. Furthermore, the actual wiring diagram in part (c) of FIG. 3 shows connections in the positive electrode region. The negative electrode region, ie, the ground region, is electrically connected via 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 via the vehicle body 2 is usually equal to or shorter than the connection of the positive electrode region by a lead wire or the like. Therefore, in part (c) of FIG. 3, 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. 3 is combined with other wiring provided in the vehicle to constitute a wire harness (not shown). Part (c) of FIG. 3 shows only the wiring J that electrically connects the devices shown in the figure.
Part (c) of FIG. 3 schematically shows the connection relationship of the wiring J between each device and the distance of the wiring J.

[Engine unit]
FIG. 4 is a partial cross-sectional view schematically showing a schematic configuration of the engine unit EU shown in FIG. 3. As shown in FIG.

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

The engine unit EU is equipped with a fuel injection device 18. The fuel injection device 18 supplies fuel to the combustion chamber by injecting fuel. The 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 chamber of engine 10.
Further, the engine unit EU is provided with an ignition device 19. The ignition device 19 includes a spark plug 19a and an ignition voltage generation circuit 19b. The spark plug 19a is provided in the engine 10. The spark plug 19a is electrically connected to the ignition voltage generation circuit 19b.
The fuel injection device 18 and the ignition device 19 are an example of the 12V electric auxiliary machine L shown in FIG. The fuel injection device 18 and the ignition device 19 are examples of engine auxiliary equipment. The fuel injection device 18 and the ignition device 19 operate at 18V system voltage.
The fuel injection device 18 and the ignition device 19 are components attached to a conventionally known engine. The fuel injector 18 and ignition device 19 operate at 12V. The maximum operating voltage, that is, the maximum rated voltage, of the fuel injection device 18 and the ignition device 19 has a voltage margin greater than 60% with respect to the nominal operating voltage of 12V. That is, the fuel injection device 18 and the ignition device 19, which operate at a basic operating voltage of 12V, can operate at 15V or more and less than 19V. Fuel injector 18 and ignition device 19 cannot operate on 24V. That is, the margin from the nominal operating voltage of the fuel injection device 18 and the ignition device 19 to the maximum operating voltage is less than 100% for 12V.

Engine 10 is an internal combustion engine. Engine 10 receives fuel supply. The engine 10 outputs power through a combustion operation of burning an air-fuel mixture. That is, the piston 13 reciprocates by combustion of the air-fuel mixture containing fuel supplied to the combustion chamber. The crankshaft 15 rotates in conjunction with the reciprocating movement of the piston 13. Power is output to the outside of the engine 10 via the crankshaft 15.
Fuel injection device 18 adjusts the power output from engine 10 by adjusting the amount of fuel supplied. The fuel injection device 18 is controlled by a control device 60. Fuel injector 18 is controlled to deliver an amount of fuel based on the amount of air supplied to engine 10. The ignition device 19 ignites a mixture of fuel and air. The fuel injection device 18 and the ignition device 19 are engine accessories that operate to cause the engine 10 to perform combustion.
Engine 10 outputs power via 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. 3).

The crankcase 11 is configured to be internally lubricated with lubricating oil (see part (b) of Figure 3). The permanent magnet generator 20 is provided at a position where it comes into contact with lubricating oil.

During four strokes, the engine 10 has a high load region in which the load to rotate the crankshaft 15 is large, and a low load region in which the load to rotate 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. Furthermore, the low load region refers to 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. When looking at the rotation angle of the crankshaft 15 as a reference, the low load area is wider than the high load area. More specifically, the engine 10 rotates in the forward direction while repeating four strokes: an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. The compression stroke has an overlap with a high load region. Engine 10 is a single cylinder engine.

FIG. 5 is a sectional view showing a cross section perpendicular to the rotational axis of the permanent magnet generator 20 shown in FIG.
The permanent magnet generator 20 will be explained with reference to FIGS. 4 and 5.

Permanent magnet generator 20 includes a rotor 30 and a stator 40. The permanent magnet generator 20 of this application example is of a radial gap type. The permanent magnet generator 20 is of an outer rotor type. That is, the rotor 30 is an outer rotor. Stator 40 is an inner stator. The rotor 30 is connected to one end of the crankshaft 15 without a reduction gear. The rotor 30 is fixed to one end of the crankshaft 15. The rotor 30 always rotates in conjunction with the rotation of the crankshaft 15.
The rotor 30 has a rotor main body portion 31. The rotor main body portion 31 is made of, for example, a ferromagnetic material. The rotor main body portion 31 has a cylindrical shape with a bottom. The rotor main body portion 31 has a cylindrical boss portion 32, a disk-shaped bottom wall portion 33, and a cylindrical 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 a winding to which current is supplied.

The rotor 30 has a permanent magnet section 37. The rotor 30 has a plurality of magnetic pole parts 37a. The plurality of magnetic pole parts 37a are formed by the permanent magnet part 37. The plurality of magnetic pole parts 37a are provided on the inner peripheral surface of the back yoke part 34. In this application example, the permanent magnet section 37 includes a plurality of permanent magnets. That is, the rotor 30 has a plurality of permanent magnets. The plurality of magnetic pole parts 37a are provided in each of the plurality of permanent magnets.
In addition, the permanent magnet part 37 can also be formed by one annular permanent magnet. In this case, one permanent magnet is magnetized so that the plurality of magnetic pole parts 37a are lined up on the inner peripheral surface.

The plurality of magnetic pole portions 37a are provided such that north poles and south poles are alternately arranged in the circumferential direction of the permanent magnet generator 20. In this application example, the number of magnetic poles of the rotor 30 facing the stator 40 is 24. The number of magnetic poles of the rotor 30 refers to the number of magnetic poles facing the stator 40. No magnetic material is provided between the magnetic pole portion 37a and the stator 40.
The magnetic pole portion 37a is provided outward from the stator 40 in the radial direction of the permanent magnet generator 20. The back yoke portion 34 is provided outward from the magnetic pole portion 37a in the radial direction. The permanent magnet generator 20 has more magnetic pole parts 37a than the number of tooth parts 45.
The rotor 30 may be an embedded magnet type (IPM type) in which the magnetic pole portion 37a is embedded in a magnetic material, but it may be a surface magnet type in which the magnetic pole portion 37a is exposed from the magnetic material as in this application example. (SPM type) is preferable.

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

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

A stator winding W is wound around each tooth portion 45 . That is, the stator windings W of multiple phases are provided so as to pass through the slots SL. In FIG. 5, the stator winding W is shown in the slot SL.

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

When the engine 10 is in operation while the straddle-type vehicle 1 is traveling, the power storage device 4 is charged by the electric power generated by the permanent magnet generator 20 . When the power storage device 4 is fully charged, the electric power generated by the permanent magnet generator 20 is not used for charging but is consumed as heat due to a short circuit in the windings, for example. In addition, when the rotational speed of the crankshaft 15 increases to such an extent that the voltage output from the inverter 21 to the power storage device 4 cannot be suppressed to 19V or less, which is the upper limit of the 18V system voltage, the inverter 21 The switching unit 211 is controlled to short-circuit the stator windings W of . The upper limit rotational speed of the crankshaft 15 that can charge the power storage device 4 can be set to a higher value than in the case of a 12V system voltage, for example.
When the generator generates electricity, the current flowing through the stator winding W is affected by the impedance generated in the stator winding W itself. Impedance is an element that obstructs the current flowing through the stator windings W. Impedance includes the product of rotational speed ω and inductance. Here, the rotational speed ω actually corresponds to the number of magnetic pole parts passing near the tooth part per unit time. That is, the rotational speed ω is proportional to the ratio of the number of magnetic poles to the number of teeth in the generator and the rotational speed of the rotor.

The permanent magnet generator 20 shown in FIG. 5 has a greater number of magnetic pole parts 37a than the number of tooth parts 45. That is, the permanent magnet generator 20 has a greater number of magnetic pole portions 37a than the number of slots SL. Therefore, the stator winding W has a large impedance. Therefore, the voltage applied to power storage device 4 is reduced compared to, for example, a case where the number of magnetic pole parts is smaller than the number of teeth. Therefore, the upper limit rotational speed of the crankshaft 15 can be set to a higher value than, for example, in the case of a 12V system voltage. Therefore, in order to increase the starting torque in the permanent magnet generator 20, a thick winding with low electrical resistance can be used.

Furthermore, in the permanent magnet generator 20, the temperature of the stator winding W does not or cannot easily rise above the temperature of the lubricating oil, so even if the permanent magnet generator 20 is placed in contact with the lubricating oil, Evaporation of lubricating oil can be suppressed. Therefore, it is possible to suppress or avoid increasing the size of the lubricating oil cooling mechanism.

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

The 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 parts 38. In other words, the rotor position detection device 50 is arranged at a position such that the plurality of detected parts 38 sequentially face the rotor position detection device 50. The rotor position detection device 50 faces the path that the detected portion 38 passes as the rotor 30 rotates. The rotor position detection device 50 is arranged at a position apart from the stator 40. In the present embodiment, the rotor position detecting device 50 is such that the back yoke portion 34 and the permanent magnet portion 37 of the rotor 30 are located between the rotor position detecting device 50 and the stator 40 and the stator winding W in the radial direction of the crankshaft 15. It is arranged so that The rotor position detection device 50 is disposed 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 a detection winding. The detection winding 51 is a winding provided separately from the stator winding W included in 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.

Power storage device 4 may be configured with, for example, one battery. For example, power storage device 4 may be configured with one battery having a nominal operating voltage of, for example, 18V. However, power storage device 4 may be configured by a plurality of power storage units.

FIG. 6 is a diagram showing an example of a variation of power storage device 4 shown in FIG. 1.

Power storage device 4 in the example shown in FIG. 6A includes a battery as first power storage unit 41 and a battery as second power storage unit 42. The power storage device 4 is provided with 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 more. For example, the first power storage unit 41 is a battery having a nominal operating voltage of 12V. For example, the first power storage unit 41 is a lead battery. The first power storage unit 41 has a capacity that can be charged with enough power to start the engine 10 at least once.
The second power storage unit 42 is always connected in series with the first power storage unit 41. Second power storage unit 42 has a maximum charging rate that is greater than twice the maximum charging rate of first power storage unit 41 . For example, the second power storage unit 42 is a battery that stores power. The second power storage unit 42 has a capacity that can be charged with enough power to start the engine 10 at least once.
Current maintenance circuit 43 allows 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 the condition. Here, "while power storage device 4 is being charged" refers to at least a time period during which first power storage unit 41 is being charged. Current maintenance circuit 43 maintains a state in which charging current flows to first power storage unit without electrically disconnecting second power storage unit 42 .
For example, the maximum charging rate of the battery as the second power storage unit 42 is greater than twice the maximum charging rate of the battery as the first power storage unit 41. The maximum rated voltage of the battery as the second power storage unit 42 is smaller than the maximum rated voltage of the battery as the first power storage unit 41. The nominal operating voltage of the battery as the second power storage unit 42 is lower than the nominal operating voltage of the battery as the first power storage unit 41.
As the power storage device 4, a configuration without the current maintenance circuit 43 can also be adopted. For example, if power storage device 4 is configured with one battery, current maintenance circuit 43 is not necessary.

The nominal operating voltage of the battery as the first power storage unit 41 is, for example, 12V. The nominal operating voltage of the battery as the second power storage unit 42 is, for example, 6V. However, the specific combination of voltages is not particularly limited, and may be, for example, a combination of 8V and 6V, a combination of 10V and 8V, a combination of 11V and 8V, or a combination of 12V and 3V. Furthermore, in anticipation of the fact that a 12V battery operates at 12.5V, a combination of 12.5V and 2.5V may be used.

Power storage device 4 in the example shown in FIG. 6(B) includes a battery as first power storage unit 41 and one capacitor as second power storage unit 42. The power storage device 4 is provided with a current maintenance circuit 43. The maximum voltage applied to one capacitor as the second power storage unit 42 is the upper limit voltage set in the 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 to the current maintenance circuit 43 is, for example, 6V. However, the upper limit voltage is not particularly limited and may be 2.5V, 3V, 8V, or 10V.

Power storage device 4 in the example shown in FIG. 6C includes a battery as first power storage unit 41 and two capacitors as second power storage unit 42. Thereby, the upper limit voltage of the current maintenance circuit 43 can be set to a voltage higher than the withstand voltage of one capacitor. Further, the second power storage unit 42 can input and output a voltage higher than the withstand voltage of one capacitor.

Power storage device 4 in the example shown in FIG. 6(D) includes a battery as first power storage unit 41 and three capacitors as second power storage unit 42. As a result, the upper limit voltage of the current sustaining circuit 43 can be set to a voltage greater than twice the withstand voltage of one capacitor. Further, the second power storage unit 42 can input and output a voltage that is higher than twice the withstand voltage of one capacitor.

The power storage device 4 in the example shown in FIG. 6(E) further includes a parallel capacitor section 44 compared to the example shown in FIG. 6(B). Parallel capacitor section 44 is connected in parallel with first power storage section 41 . The parallel capacitor section 44 includes one capacitor. This configuration is suitable when the withstand voltage of one capacitor is higher than that of the battery serving as the first power storage unit 41.
A capacitor can generally provide power for a shorter period of time than a battery discharging the same power. The internal resistance of a capacitor is generally smaller than that of a battery. The capacitor also stores power (charge) that is substantially proportional to the voltage. A capacitor can discharge power that is generally proportional to the voltage.
Therefore, for example, after the power in the first power storage section 41 and the parallel capacitor section 44 is consumed by starting the engine, voltage can be supplied from the first power storage section 41 to the parallel capacitor section 44 . That is, the parallel capacitor section 44 can be charged with the power of the first power storage section 41. Even in a situation where the first power storage section 41 cannot independently supply the electric power required for starting the engine at the next engine start, there is a high possibility that the parallel capacitor section 44 can supply the electric power required for starting.

In the power storage device 4 shown in FIG. 6(F), a parallel capacitor section 44 is added to the example shown in FIG. 6(C).
As in the example shown in FIG. 6F, the number of capacitors that first power storage unit 41 has and the number of capacitors that parallel capacitor unit 44 has may be different. The number of capacitors that the first power storage unit 41 has and the number of capacitors that the parallel capacitor unit 44 has are selected depending on the upper limit voltage of the current maintenance circuit 43 and the maximum rated voltage of the battery as the first power storage unit 41. is possible. In the example power storage device 4 shown in FIG. 6(F), the parallel capacitor section 44 includes four capacitors.

In the power storage device 4 shown in FIG. 6(G), a parallel capacitor section 44 is added to the example shown in FIG. 6(D). In the example power storage device 4 shown in FIG. 6(G), the parallel capacitor section 44 includes three capacitors.

The number of batteries and the number of capacitors are not limited to the numbers shown in FIGS. 6A to 6G.
For example, in the power storage device 4 shown in FIG. 6G, the parallel capacitor section 44 may include six capacitors. It is easy to maintain a balance between the maximum rated voltages of the capacitors that make up the first power storage section 41 and the capacitors that make up the parallel capacitor section 44.
Furthermore, with respect to the power storage device 4, the first power storage unit 41 may include, for example, two sets of capacitors connected in parallel to each other. The capacitor set is composed of, for example, three capacitors connected in series. In this case, the capacity of first power storage unit 41 increases. For example, the parallel capacitor section 44 may further include six capacitors.
The capacitor that parallel capacitor section 44 has and the capacitor that second power storage section 42 has are of the same type. For example, capacitors with the same maximum rated voltage and capacitance are the same type of capacitor.
However, the capacitor included in parallel capacitor section 44 and the capacitor included in second power storage section 42 may be of different types.

1 Straddle type vehicle 3a, 3b Wheels 4 Power storage device 10 Engine 15 Crankshaft 20 Permanent magnet generator 21 Inverter

Claims (8)

A straddle-type vehicle,
The straddle-type vehicle is
wheels and
an engine that has a crankshaft and outputs torque for driving the wheels generated by a combustion operation from the crankshaft;
A 12V electric auxiliary machine that has a nominal operating voltage of 12V and operates upon receiving electric power;
a permanent magnet generator that is provided at one end of the crankshaft, has a permanent magnet, starts or assists the engine by rotating the crankshaft, and generates electricity by being driven by the engine;
A power storage device that stores electricity;
an inverter that is electrically connected to the permanent magnet generator and the power storage device and includes a plurality of switching units that control the current output from the permanent magnet generator,
The inverter transfers a 18V system voltage of 15V or more and less than 19V, which is generated by the permanent magnet generator provided at one end of the crankshaft without a reduction gear, to the power storage device corresponding to the 18V system voltage. applying the 18V system voltage to the 12V system electric auxiliary machine to operate the 12V system electric auxiliary machine while charging the power storage device corresponding to the 18V system voltage by applying the 18V system voltage to the 12V system electric auxiliary machine ;
The power storage device corresponding to the 18V system voltage is
A combination of a battery with a nominal operating voltage of 12V and a battery with a nominal voltage of 6V, which are always connected in series.
A combination of a battery with a nominal operating voltage of 10V and a battery with a nominal voltage of 8V, which are always connected in series.
or
A combination of a battery with a nominal operating voltage of 12V and a capacitor with a maximum voltage of 6V, which are always connected in series.
Equipped with The saddle type vehicle according to claim 1,
The 12V electric auxiliary machine is an engine auxiliary machine that operates to cause the engine to perform combustion. The straddle-type vehicle according to claim 2,
The engine auxiliary equipment includes an injection device that injects fuel toward or inside the engine, and an ignition device that ignites the fuel inside the engine. A straddle-type vehicle according to any one of claims 1 to 3,
The permanent magnet generator includes a rotor that has a plurality of magnetic pole parts made of the permanent magnets and is connected to one end of the crankshaft without a reduction gear;
A stator core having a plurality of teeth in which a plurality of slots are formed at intervals in a circumferential direction of the permanent magnet generator, and a stator having a winding provided to pass through the slots,
The number of the magnetic pole parts is greater than the number of the plurality of teeth.

A straddle-type vehicle according to any one of claims 1 to 3,
The permanent magnet generator includes a rotor that has a plurality of magnetic pole parts made of the permanent magnets and is connected to one end of the crankshaft without a reduction gear;
a stator having a stator core in which a plurality of slots are formed at intervals in a 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 a detection winding provided at a position facing the plurality of detected parts and provided separately from the stator winding;
Equipped with A straddle-type vehicle according to any one of claims 1 to 5,
The engine further includes a crankcase configured to be internally lubricated with oil,
The permanent magnet generator is provided at a position where it comes into contact with the oil. A straddle-type vehicle according to any one of claims 1 to 6,
The inverter supplies electric power from the power storage device to the permanent magnet generator while the straddle-type vehicle is running, and causes the permanent magnet generator to assist rotation of the crankshaft. A straddle-type vehicle according to any one of claims 1 to 7,
The 12V nominal operating voltage of the 12V electric auxiliary machine is determined by the display regarding the 12V electric auxiliary machine, the structure and material of the 12V electric auxiliary machine, and the operation and/or function of the 12V electric auxiliary machine. identified by at least one element selected from the group consisting of:

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