Electric vehicle

Abstract

Provided is an electric vehicle capable of: charging a sub-battery by traveling of the vehicle; and continuing to travel by switching from a main battery to the sub-battery when the remaining charge of the main battery becomes low.　The electric vehicle according to the present invention comprises: a drive motor that rotates a drive wheel; a power generation motor that generates power by rotation of a driven wheel; a main battery that supplies power to the drive motor; a sub-battery that can store the power generated by the power generation motor; a battery state detection unit that measures the states of charge of the main battery and the sub-battery; a changeover switch that switches power supply to the drive motor between the main battery and the sub-battery; and a cutoff switch that cuts off charging of the sub-battery. When the power of the main battery becomes less than a threshold value due to traveling of the vehicle, charging of the sub-battery is cut off by the cutoff switch, and the changeover switch switches from the main battery to the sub-battery.

Description

Electric vehicle

[0001] The present invention relates to an electric vehicle, and specifically, to an electric vehicle that has a power generation motor on the front wheels to specifically charge a sub-battery, and when the storage capacity of the main battery decreases, switches to the sub-battery and further travels.

[0002] Patent Document 1 discloses a structure in which power packs 120A and 120B for driving a motor of a vehicle are provided, the vehicle travels using one power pack, and when the remaining capacity of that power pack decreases, switches to the other power pack and travels to extend the driving distance. However, Patent Document 1 does not describe charging the power packs 120A and 120B during driving.

[0003] Patent Document 2 discloses a structure in which a plurality of batteries for supplying power to a motor that drives the rear wheels are provided, and when the motor is in a state where it can supply regenerative power, regenerative power is supplied to and charges the battery with the least remaining amount among the plurality of batteries. This control is excellent in terms of recovering regenerative power, but detecting the conditions for recovering regenerative power when there is no need to drive the rear wheels by the motor and switching the power supply path are complicated. Also, converting the rotational energy of the wheels into electrical energy and storing it is not shown.

[0004] Japanese Patent Application Laid-Open No. 2004-359032 Japanese Patent Application Laid-Open No. 2022-149725

[0005] An object of the present invention is to provide an electric vehicle that can convert the rotational energy of the wheels into electricity and store it in a sub-battery during vehicle travel, and when the main battery that drives the wheels runs out, switch from the main battery to the sub-battery and make the vehicle travel.

[0006] The electric vehicle according to the present invention is an electric vehicle in which one of the front wheels and the other rear wheel is a drive wheel and the other is a driven wheel, and comprises a drive motor for rotating the drive wheel, a generator motor for generating electricity by the rotation of the driven wheel, a main battery for supplying power to the drive motor, a sub-battery capable of storing the power generated by the generator motor, a battery state detection unit provided in the main battery and the sub-battery respectively for measuring the remaining charge, a changeover switch for switching the power supply to the drive motor between the main battery and the sub-battery, and a cutoff switch for cutting off the charging from the generator motor to the sub-battery, wherein when the power of the main battery falls below a threshold due to the operation of the vehicle, the cutoff switch cuts off the charging to the sub-battery and the changeover switch switches from the main battery to the sub-battery.

[0007] Furthermore, the present invention is characterized in that a large-diameter drive wheel is attached to the driven wheel so as to rotate coaxially, a small-diameter driven wheel is attached to the rotating shaft of the power generation motor, and the drive wheel and the driven wheel are connected by a transmission belt.

[0008] Furthermore, the main battery and the sub-battery are characterized by being rechargeable from an external source via charging terminals.

[0009] The electric vehicle according to the present invention is equipped with two batteries, a main battery and a sub-battery. A generator motor converts the rotational energy of the wheels into electrical energy, which is stored in the sub-battery. Therefore, when the remaining charge of the main battery becomes low, the system can switch from the main battery to the sub-battery to supply power to the drive motor, thereby allowing the vehicle to continue running.

[0010] A large-diameter wheel is mounted on the driven wheel to rotate coaxially, and a small-diameter wheel is mounted on the rotating shaft of the power generation motor. The two are connected by a transmission belt, allowing the rotor of the power generation motor to rotate at a higher rotational speed (revolutions / minute) than the rotational speed (revolutions / minute) of the driven wheel. This enables the generation of a large amount of electricity.

[0011] The main battery and auxiliary battery can be charged externally via charging terminals. For example, (1) if the main battery runs out, the vehicle can be driven again by charging it externally. (2) The auxiliary battery can also be charged and driven. This ensures a driving range equal to the combined amount of electricity in the main and auxiliary batteries.

[0012] This is a structural diagram of an electric vehicle according to the present invention. This is a block diagram showing the battery configuration of an electric vehicle. This diagram shows that a large-diameter drive wheel provided on the front wheel and a small-diameter driven wheel provided on the generator motor are connected by a belt. This diagram shows the relationship between the battery and the drive motor while the vehicle is running. This is a flowchart showing the switching between the main battery and the sub-battery while the vehicle is running. This is an explanatory diagram showing that the main battery and the sub-battery 7 are charged by an external charger. This is an explanatory diagram showing that the vehicle alternates between running with the main battery driving the drive motor and the generator motor charging the sub-battery, and running with the sub-battery driving the drive motor and the generator motor charging the main battery.

[0013] Hereinafter, an embodiment of the electric vehicle 100 according to the present invention will be described with reference to the drawings.

[0014] Figure 1 is a structural diagram of the electric vehicle 100 according to the present invention. The electric vehicle 100 in this embodiment is an electric two-wheeled vehicle. However, it is not limited to this and can also be applied to electric three-wheeled vehicles and electric assist bicycles with pedals. The electric vehicle 100 is equipped with a main body 3, a front wheel 1 that is rotated by a handle, and a rear wheel 2 that is driven by a three-phase AC drive motor 5. A three-phase AC power generation motor 4 is attached to the front wheel 1. The electricity generated by the power generation motor 4 is stored in the sub-battery 7 if the sub-battery 7 is not fully charged. The drive motor 5 rotates by receiving power from the main battery 6 or the sub-battery 7. A warning lamp 22 indicating that the power of the main battery 6 has fallen below a threshold and a warning lamp 23 indicating that the power of the sub-battery 7 has fallen below a threshold are provided on the top of the handle.

[0015] Figure 2 is a block diagram showing the battery configuration of the electric vehicle 100. The battery consists of a main battery 6 and a sub-battery 7. The main battery 6, drive motor 5, and rear wheels 2 form the drive system, and in addition, the sub-battery 7, generator motor 4, and front wheels 1 form the driven system, and there is a switching system to switch between the main battery 6 and the sub-battery 7. In this configuration, the rear wheels 2 are the drive wheels and the front wheels 1 are the driven wheels.

[0016] When the electric vehicle 100 is powered by the main battery 6, power is supplied from the main battery 6 to the drive motor 5 via the changeover switch 13, causing the drive motor 5 to rotate, and this rotation is transmitted to the rear wheels 2. When the rear wheels 2 rotate, the driven front wheels 1 rotate, and the electric vehicle 100 moves. The main battery 6 has charging terminals and is a battery that can be charged from an external source.

[0017] The sub-battery 7 is charged by a generator motor 4 that generates electricity from the rotation of the front wheel 1. Since the generator motor 4 is a three-phase AC motor, the AC is converted to DC by a converter 17 and sent to the sub-battery 7 via a cutoff switch 12. When charging is sufficient and the sub-battery 7 is fully charged, the cutoff switch 12 is cut off by the switching control unit 8 and charging stops. The sub-battery 7 is equipped with a sub-battery state detection unit 14B that detects the charging state (determining whether there is power by measuring the voltage), and the state of the sub-battery 7 is sent to the switching control unit 8 by a detection signal. The sub-battery 7, like the main battery 6, also has charging terminals and can be charged from the outside.

[0018] The changeover switch 13 switches whether the power supplied to the drive motor 5 comes from the main battery 6 or the sub-battery 7. The main battery 6 is equipped with a main battery state detection unit 14A that detects the charge state, and the state of the main battery 6 is sent to the switching control unit 8 by the output signal of the main battery state detection unit 14A. For example, if the power of the main battery 6 falls below a threshold, the switching control unit 8 switches the changeover switch 13 from the main battery 6 to the sub-battery 7.

[0019] Figure 3 shows that a large-diameter drive wheel 9 on the front wheel 1 and a small-diameter driven wheel 10 on the power generation motor 4 are connected by a belt 16. The drive wheel 9 is attached to the axle 15 of the front wheel 1, and the driven wheel 10 is attached to the rotating shaft 11 of the power generation motor 4. As a result, since the small-diameter driven wheel 10 is connected to the large-diameter drive wheel 9, the rotational speed of the rotor of the power generation motor 4 per unit time can be made greater than the rotational speed of the front wheel 1, and a large amount of power can be generated. On a downhill slope, the front wheel 1 rotates at high speed, so the charging of the sub-battery 7 proceeds efficiently.

[0020] Figure 4 shows the relationship between the battery and the drive motor while the vehicle is running. (A) shows that the drive motor 5 is driven by the main battery 6 and the electric vehicle 100 is running. At this time, the rotational energy of the front wheel 1 is converted into electricity by the generator motor 4 and stored in the sub-battery 7. (B) shows that the drive motor 5 is driven by the sub-battery 7 and the electric vehicle 100 is running. At this time, the connection between the generator motor 4 and the sub-battery 7 is cut off by the cut-off switch 12, so the sub-battery 7 is not charged by the generator motor 4.

[0021] Figure 5 is a flowchart showing the switching between the main battery 6 and the sub-battery 7 while the vehicle is running. When the electric vehicle 100 is instructed to run by a lever on the handlebars, the drive motor 5 is driven by the power of the main battery 6 and the vehicle starts running (S10). As a result, the rear wheels 2 rotate and the electric vehicle 100 moves (S11). The main battery 6 is assumed to be charged from an external source before running. When the electric vehicle 100 has traveled a certain distance, the power of the main battery 6 decreases, so the switching control unit 8 checks whether the power of the main battery 6 has fallen below a threshold (S12).

[0022] If the power of the main battery 6 falls below a threshold, the warning lamp 22 on the top of the handlebars (see Figure 1) lights up (S13). Then, the changeover switch 13 is switched from the main battery 6 to the sub-battery 7 (S14). Also, charging of the sub-battery 7 by the generator motor 4 is stopped (S15). Charging of the sub-battery 7 is stopped by shutting off the cutoff switch 12. Since power is supplied to the drive motor 5 from the sub-battery 7, the electric vehicle 100 can continue to run (S16).

[0023] When the electric vehicle 100 has traveled a certain distance, the power of the sub-battery 7 decreases, so the switching control unit 8 checks whether the sub-battery 7 has fallen below a threshold (S17). If the sub-battery 7 is below the threshold, the warning lamp 23 (see Figure 1) lights up (S19). Since it is no longer possible to travel any further, the operation ends here.

[0024] Returning to the judgment in S12, if there is still power remaining in the main battery 6, it is checked whether the sub-battery 7 is fully charged or not (S20). If the sub-battery 7 is not fully charged, the generator motor 4 charges the sub-battery 7 (S22). If the sub-battery 7 is fully charged, the generator motor 4 stops charging the sub-battery 7 (S21). This is done by turning on the cutoff switch 12.

[0025] Figure 6 is an explanatory diagram illustrating how to charge the main battery 6 and sub-battery 7 from an external source. The main battery 6 and sub-battery 7 of the electric vehicle 100 have charging terminals 19, 19, and are charged by connecting cables 21, 21 from an external charger 20, 20. Alternatively, the main battery 6 and sub-battery 7 may be removed from the main unit 3 and charged separately. When the electric vehicle 100 is to be driven over a long distance, the main battery 6 and sub-battery 7 should be charged in advance. This allows the vehicle to travel a distance equivalent to the power of the main battery 6 and sub-battery 7. This allows for a longer distance to be traveled than when only the main battery 6 is charged and the sub-battery 7 is empty. When the electric vehicle 100 is driven after charging the main battery 6 and sub-battery 7, the drive motor 5 is initially driven by the power of the sub-battery 7. When the power of the sub-battery 7 falls below a threshold, the vehicle switches to the main battery 6 for driving. At this time, the sub-battery 7 is charged by the generator motor 4. Therefore, if the power of the main battery 6 falls below a threshold, the vehicle can continue to run using the power stored in the sub-battery 7. In this embodiment, the storage capacity of the sub-battery 7 cannot exceed the capacity of the main battery 6, so it can have a smaller capacity than the main battery 6.

[0026] In this embodiment, a configuration was described in which the power generation motor 4 is connected to the sub-battery 7 via a cutoff switch 12. However, it is also possible to configure the system so that the power generation motor 4 is connected to the main battery 6 when the cutoff switch 12 cuts off the connection between the power generation motor 4 and the sub-battery 7. As shown in Figure 2, this can be achieved by providing a line 24 that connects the power generation motor 4 and the main battery 6 via the cutoff switch 12. With this configuration, the main battery 6 can be charged by the power generation motor 4. As shown in Figure 7, it is possible to alternately perform driving operations in which the main battery 6 drives the drive motor 5 and the power generation motor 4 charges the sub-battery 7, and driving operations in which the sub-battery 7 drives the drive motor 5 and the power generation motor 4 charges the main battery 6.

[0027] The electric vehicle of the present invention is equipped with a main battery 6 and a sub-battery 7, and the sub-battery 7 is charged by a power generation motor 4 that generates electricity from the rotation of the front wheel, making it suitable for electric motorcycles and the like.

[0028] 1 Front wheel (driven wheel) 2 Rear wheel (drive wheel) 3 Main body 4 Generator motor 5 Drive motor 6 Main battery 7 Sub-battery 8 Switching control unit 9 Drive wheel 10 Drive wheel 11 Rotating shaft 12 Cut-off switch 13 Switching switch 14A Main battery status detection unit 14B Sub-battery status detection unit 15 Front wheel shaft 16 Belt 17 Converter 18 Inverter 19 Charging terminal 20 External charger 21 Cable 22 Warning lamp A 23 Warning lamp B 24 Line 100 Electric vehicle

Claims

1. An electric vehicle in which one of the front wheels and the other rear wheel is a drive wheel and the other is a driven wheel, comprising: a drive motor for rotating the drive wheel; a generator motor for generating electricity by the rotation of the driven wheel; a main battery for supplying power to the drive motor; a sub-battery capable of storing the power generated by the generator motor; battery state detection units provided in the main battery and the sub-battery, respectively, for measuring the remaining charge; a changeover switch for switching the power supply to the drive motor between the main battery and the sub-battery; and a cutoff switch for cutting off the charging from the generator motor to the sub-battery, wherein when the power of the main battery falls below a threshold due to the operation of the vehicle, the cutoff switch cuts off the charging to the sub-battery and the changeover switch switches from the main battery to the sub-battery.

2. The electric vehicle according to claim 1, characterized in that a large-diameter drive wheel is mounted on the driven wheel so as to rotate coaxially, a small-diameter driven wheel is mounted on the rotating shaft of the power generation motor, and the drive wheel and the driven wheel are connected by a transmission belt.

3. The electric vehicle according to claim 1, characterized in that the main battery and the sub-battery can be charged from an external source via charging terminals.

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