JP4048766B2 - Hybrid vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hybrid vehicle including a traveling motor that accumulates electric power generated by a generator in a battery and operates by feeding power from the battery.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is known a hybrid vehicle equipped with an engine and an electric motor and achieving high efficiency, reduction of exhaust gas, and the like by operating those power sources simultaneously or individually depending on the situation. Such hybrid vehicles are roughly classified into series type hybrid vehicles and parallel type hybrid vehicles. Among these, in the series hybrid vehicle, an electric motor is used as a drive source of the vehicle. This electric motor is operated by power supply from a battery, but since there is a limit to the distance that can be continuously traveled by one charge, charging can be performed even during traveling by operating a separately mounted engine. .
[0003]
In a series-type hybrid vehicle, generally, the remaining amount of the battery while the vehicle is traveling is monitored by a control device such as an ECU. The generator is automatically activated and stopped according to the remaining amount of the battery. For example, when the remaining amount of the battery falls below a certain value while the vehicle is running, the engine is operated by the control device, and the insufficient power is generated by the generator. On the contrary, when the remaining amount of the battery exceeds a certain value, the engine is stopped by the control device, and power generation is not performed, thereby preventing problems such as overcharging.
[0004]
[Problems to be solved by the invention]
However, the series-type hybrid vehicle described above is problematic because the generator may not be appropriately activated and stopped according to the usage mode of the vehicle.
For example, when the remaining battery level is below a certain value, starting a series hybrid vehicle will start the engine uniformly to generate power even when the user's destination is very close. Will be. However, if the destination is very close, it is possible to travel with only the electric motor even if the remaining battery level is low, and the user wants to travel cleanly and quietly with only the electric motor. There is a case. Nevertheless, if the engine is started each time the vehicle is started, it will not only run as desired by the user, but it will also cause an increase in exhaust gas and a deterioration in fuel efficiency. Met.
[0005]
The present invention has been made to solve such a problem, and an object of the present invention is to provide a hybrid vehicle capable of operating and stopping a generator more appropriately in accordance with a use mode of the vehicle.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the invention as described in each claim is configured.
The hybrid vehicle according to claim 1 is an engine, a generator that is driven by the engine to generate electric power, a battery that accumulates electric power generated by the generator, and a traveling vehicle that is operated by power supply from the battery. And a motor. The power generator includes a switching unit that switches the power generation by the power generator to a power generation mode and a non-power generation mode. When the switching unit is switched to the no power generation mode, power generation by the power generator is stopped. Thereby, the user can arbitrarily stop the generator only by operating the switching means constituted by, for example, a changeover switch, and can operate and stop the generator more appropriately according to the usage mode of the vehicle. Can do. For example, when the distance to the destination is very close, the vehicle can be quietly driven only by the traveling motor without operating the generator.
[0007]
The hybrid vehicle according to a second aspect of the present invention includes travel state detection means for detecting whether or not the vehicle is traveling. Then, when the switching unit is switched to the power generation mode and the traveling state detection unit detects that the vehicle is not traveling, power generation by the generator is stopped by the control unit or the like.
When the vehicle is not running, that is, when the vehicle is stopped, the battery can be charged by conducting power from an outlet of the household power supply, etc., so it is necessary to operate even the generator There is no. According to the hybrid vehicle of the second aspect, since the generator is automatically stopped in such a case, wasteful generation of exhaust gas, wasteful consumption of fuel, and the like are prevented.
[0008]
According to a third aspect of the present invention, the hybrid vehicle includes a charging state detection unit that detects whether or not a battery charger that charges power from the outside is being charged. Then, when the switching unit is switched to the power generation mode and the charging state detection unit detects that the charger is being charged, the control unit or the like stops the power generation by the generator. When the battery is charged by the charger, the power generation by the generator is not required. According to the hybrid vehicle of the third aspect, since power generation by the generator is automatically stopped in such a case, wasteful generation of exhaust gas, wasteful consumption of fuel, and the like are prevented.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a hybrid vehicle 1 in the present embodiment.
As shown in FIG. 1, the hybrid vehicle 1 according to the present embodiment includes a traveling motor 11 that rotates by power feeding from a battery 10 as a drive source. An axle 12 is connected to the output shaft of the traveling motor 11 via a differential gear 16, and wheels 15 are provided at both ends of the axle 12 to constitute a drive system of the hybrid vehicle 1.
Note that the hybrid vehicle 1 is not necessarily provided with the axle 12 or the differential gear 16. For example, the present invention can be applied even when the traveling motor 11 is built in the hub of the wheel 15 and configured as a wheel-in motor.
[0010]
A DC motor is used as the traveling motor 11, and a battery 10 is provided as a power source for the traveling motor 11. The battery 10 is a rechargeable secondary battery such as a nickel metal hydride battery or a sealed lead battery, but other types of secondary batteries may be used. The electric power stored in the battery 10 may be used as a power source for an ECU (electronic control unit) 4 that controls the entire hybrid vehicle 1 and other devices such as a lighting device.
[0011]
The hybrid vehicle 1 is equipped with an engine 20 as a power source separate from the traveling motor 11. The engine 20 is a normal gasoline engine, but a diesel engine or an engine that burns other fuel may be used.
The engine 20 in the present embodiment does not work as a power source for directly rotating the axle 12 but rather as a power source for rotating the generator 21 to generate electricity. A generator 21 is connected to the output shaft of the engine 20, and the kinetic energy of the engine 20 is taken out as electrical energy by the generator 21. The generator 21 and the battery 10 are connected via an inverter (not shown), and the electric power generated by the generator 21 is converted into a direct current and then charged to the battery 10. .
The engine 20 and the generator 21 are electrically connected to the ECU 4, and the operation and stop timing of the generator 21 is controlled based on a control signal issued from the ECU 4. This ECU 4 corresponds to “control means” in the present invention. Details of the control will be described later.
[0012]
A voltage detector 13 and a charger 3 are electrically connected to the battery 10.
The voltage detector 13 detects the output voltage of the battery 10 and transmits it to the ECU 4. The ECU 4 monitors the output voltage of the battery 10 based on the transmission signal from the voltage detector 13. The ECU 4 also monitors the state of charge (SOC) of the battery 10 by monitoring the output voltage of the battery 10. That is, when the state of charge of the battery 10 changes, the output voltage of the battery 10 also changes correspondingly. Based on a certain correlation between the state of charge and the output voltage, the battery 10 is charged. The state is determined by using a means such as calculation. For example, when the power charged in the secondary battery decreases, the output voltage value generally decreases accordingly, but based on the correlation between the state of charge SOC and the output voltage. The charge state of the battery 10 is monitored by the ECU 4 as needed.
[0013]
The charger 3 is a charger for charging the battery 10 with the electric power guided from the external power source 30 instead of the electric power generated by the generator 21. For the charger 3, for example, a known charger that can be charged by converting an alternating current into a direct current is used. As the external power source 30, for example, a household 100V power outlet is used, but other external power sources such as a commercial power outlet may be used.
The charger 3 and the ECU 4 are electrically connected. The ECU 4 determines whether or not the charger 3 is “charging”. Specifically, a current value flowing from the charger 3 toward the battery 10 is monitored by the ECU 4, and it is determined whether charging by the charger 3 is performed based on the magnitude of the current value. For example, if the current value flowing from the charger 3 toward the battery 10 is “0”, it is determined that charging by the charger 3 is not performed. That is, this ECU 4 also corresponds to “charge state detection means” in the present invention.
[0014]
A rotation speed detector 17 is connected to the output shaft of the traveling motor 11. The rotational speed detector 17 is provided to detect the rotational speed and rotational speed of the traveling motor 11 per time, and is constituted by an encoder, for example. The rotational speed detector 17 and the ECU 4 are electrically connected, and the rotational speed of the traveling motor 11 is monitored by the ECU 4 based on a detection signal transmitted from the rotational speed detector 17.
Further, the ECU 4 determines whether or not the hybrid vehicle 1 is traveling based on the rotational speed of the traveling motor 11 detected by the rotational speed detector 17. For example, if the rotational speed of the traveling motor 11 is “0” or a value that is very low enough to be regarded as “0”, it is determined that the hybrid vehicle 1 is “stopped”. That is, the ECU 4 also corresponds to “running state detection means” in the present invention.
[0015]
The ECU 4 in the present embodiment is constituted by a microcomputer, and transmits a control signal to the engine 20, the generator 21, the traveling motor 11 and the like, and controls the operating states of these devices according to predetermined conditions. .
The ECU 4 is connected to a selector switch 6 for switching the power generation by the generator 21 between a power generation mode (hereinafter referred to as “HEV mode”) and a non-power generation mode (hereinafter referred to as “PEV mode”). When the HEV mode is selected by the changeover switch 6, the operating state of the generator 21 is controlled according to a predetermined condition. On the contrary, when the PEV mode is selected by the changeover switch 6, the generator 21 is stopped without following a predetermined condition or the like.
In addition, a system activation switch 5 for activating a vehicle system that monitors and controls the entire hybrid vehicle 1 is connected to the ECU 4. The system activation switch 5 is linked to the key switch of the hybrid vehicle 1. When the key is inserted into the vehicle and rotated to the “ON” position, the vehicle system is activated and the hybrid vehicle 1 can run. It becomes a state.
Note that the changeover switch 6 and the system activation switch 5 may be installed as an integrated switch in conjunction with the key switch of the vehicle, or may be installed as separate switches in the vehicle interior.
[0016]
In the hybrid vehicle 1 configured as described above, how the operating state of the generator 21 is controlled by the ECU 4 will be described with reference to the flowchart of FIG.
[0017]
The control process shown in the flowchart of FIG. 2 will be described in detail below.
The flowchart shown in FIG. 2 shows the procedure of the control process in the case where “the rotational speed of the traveling motor 11” and “the charging state of the charger 3” are monitored by the ECU 4 together.
First, in the process of step S11, the ECU 4 determines whether or not the system activation switch 5 is “ON”. If it is determined that the system activation switch 5 is “ON” (YES), the process proceeds to the next step S12. If it is determined that the system activation switch 5 is not “ON” (NO), the process proceeds to step S20, and the “generator stopped state” process is performed. In the “generator stopped state” process, a process for keeping the generator 21 stopped or for stopping the already activated generator 21 is performed.
[0018]
Next, in the “vehicle system activation state” process in step S12, a process for activating a vehicle system for monitoring and controlling the entire hybrid vehicle 1 is performed. Specifically, power for starting the vehicle system is supplied from the battery 10 or the like, or processing for initializing setting values for controlling various devices provided in the vehicle is performed.
When the processing of “vehicle system activation state” ends, the process proceeds to step S13.
[0019]
In the “travelable state” process in step S13, a process for making the hybrid vehicle 1 actually travelable is performed. Specifically, to supply power to various operating devices such as speedometers, fuel meters, power window systems, power steering systems, sensors, etc., or to activate by sending an activation signal Processing is performed.
When the “travelable state” process in step S13 ends, the process proceeds to step 14.
[0020]
In the process of step S14, based on the detection signal transmitted from the rotational speed detector 17, it is determined whether or not the rotational speed of the traveling motor 11 is “0”. When it is determined that the rotational speed of the traveling motor 11 is “0” (YES), the process proceeds to the “generator stopped state” process in step S20, and the generator 21 is stopped. When it is determined that the rotational speed of the traveling motor 11 is not “0” (NO), the process proceeds to the next step S15. Note that the fact that the rotational speed of the traveling motor 11 is “0” does not mean that the rotational speed of the output shaft of the traveling motor 11 must be strictly “0”. For example, if the rotational speed is close to “0” to such an extent that the hybrid vehicle 1 can be recognized as being stopped, it can be determined that it is “0” and the process can proceed to step S20.
[0021]
In the process of step S15, it is determined whether or not the selector switch 6 has been switched to the “HEV mode”. When the changeover switch 6 is switched to the “HEV mode” (YES), the process proceeds to the next step S16. When the changeover switch 6 is not switched to the “HEV mode” (that is, in the “PEV mode”) (NO), the process proceeds to the “generator stopped state” process in step S20, and the generator 21 is stopped. Is done.
[0022]
In the process of “generator startable state” in step S16, a process for making the generator 21 ready for actual start is performed. Specifically, a process for supplying power to the generator 21 to be in a standby state and setting the power generation state immediately when the generator 21 is rotated by the engine 20 is performed.
When the “generator startable state” processing in step S16 is completed, the process proceeds to step S17.
[0023]
In the process of step S <b> 17, it is determined based on the signal transmitted by the voltage detector 13 whether or not the state of charge SOC of the battery 10 is equal to or less than the “required power supply level”. The “required power supply level” refers to a level serving as a reference for determining that charging is required because the power remaining in the battery 10 is reduced. For example, 60% of the total amount of power that can be stored in the battery 10 can be set as the “required power supply level”.
When it is determined that the state of charge is equal to or lower than the “power supply level” (YES), the process proceeds to the next step S18. When it is determined that the state of charge is not equal to or lower than the “required power supply level” (NO), the process proceeds to the “generator stopped state” process in step S20, and the generator 21 is stopped.
[0024]
In the process of step S18, it is determined whether or not the charger 3 is “charging”. When it is determined that the charger 3 is “charging” (YES), the process proceeds to step S20 and the generator 21 is stopped. If it is determined that the charger 3 is not “charging” (NO), the process proceeds to the next step S19.
[0025]
In the process of step S19, an activation signal is transmitted to the engine 20. As a result, the engine 20 is started, and the electric power generated by the generator 21 is supplied to the battery 10.
When the process of step S19 or step S20 ends, the control process shown in the flowchart of FIG. 2 ends [return]. The control process shown in the flowchart of FIG. 2 may be executed a plurality of times as necessary, for example, when a program for executing such a control process is periodically read by the ECU 4.
[0026]
As described above, according to the control process shown in the flowchart of FIG. 2, when the changeover switch 6 is switched to the “PEV mode”, the ECU 21 determines that the generator 21 does not determine other conditions. Will be stopped. Thereby, for example, when the destination to be moved is very close, and the user wants to run the hybrid vehicle 1 with only the running motor 11 without starting the engine 20 or the generator 21, The user can drive the hybrid vehicle 1 as such only by switching the changeover switch 6 to the “PEV mode”. On the other hand, when the user wants to travel the hybrid vehicle 1 while generating power by operating the engine 20 or the generator 21 when moving to a far destination, the user switches the switch 6 The hybrid vehicle 1 can be made to travel as such only by switching to “HEV mode”. When it is not necessary to operate, the engine 20 and the generator 21 can be stopped, so that it is possible to reduce the generation amount of exhaust gas such as CO ₂ and fuel consumption.
[0027]
Further, according to the control process shown in the flowchart of FIG. 2, when it is determined in step S <b> 14 that the rotational speed of the traveling motor 11 is “0” (YES), that is, the hybrid vehicle 1 is stopped. If determined, the generator 21 is stopped in the process of step S20.
In general, when the hybrid vehicle 1 is stopped, the battery 10 can be charged by connecting the charger 3 to an external power source 30 (for example, an outlet of a household power source). Therefore, there is no need to bother the generator 21 and charge the battery 10. According to the control process shown in the flowchart of FIG. 2, when it is not necessary to operate such a generator 21, the generator 21 is automatically stopped by the ECU 4. As a result, it is possible to expect the effect of reducing the amount of exhaust gas generated from the engine 20 and the amount of fuel consumed.
[0028]
Further, according to the control process shown in the flowchart of FIG. 2, when it is determined in step S18 that the charger 3 is “charging” (YES), the generator 21 is stopped in the process of step S20.
When the charger 3 is “charging”, it is not necessary to charge the battery 10 twice until both the engine 20 and the generator 21 are operated. According to the control process shown in the flowchart of FIG. 2, when it is not necessary to operate such a generator 21, the generator 21 is automatically stopped by the ECU 4. As a result, it is possible to expect the effect of reducing the amount of exhaust gas generated from the engine 20 and the amount of fuel consumed.
[0029]
The present invention can be implemented even in the case where one or both of Step 14 and Step S18 are not performed in the control processing shown in the flowchart of FIG.
For example, in the control process shown in the flowchart of FIG. 2, even when the process of determining whether or not the rotational speed of the traveling motor 11 is “0” in step S <b> 14 is not performed, By simply switching the switch 6 to the “PEV mode”, the hybrid vehicle 1 can be run without generating power by the generator 21. Thereby, it is possible to drive the hybrid vehicle 1 quietly, and it is possible to reduce the generation amount of exhaust gas and the consumption amount of fuel.
Further, for example, even in the case where it is not determined in step S18 whether or not the charger 3 is “charging”, the user only switches the changeover switch 6 to “PEV mode”. The hybrid vehicle 1 can be run with the generator 21 stopped. Thereby, it is possible to drive the hybrid vehicle 1 quietly, and it is possible to reduce the generation amount of exhaust gas and the consumption amount of fuel.
[0030]
In the embodiment, an example in which the present invention is applied to a series-type hybrid vehicle has been described. However, the present invention is not limited to this. The present invention can be applied to a parallel type hybrid vehicle, and can also be applied to a series / parallel type hybrid vehicle combining a series type and a parallel type.
[0031]
In the embodiment, the example in which the present invention is applied to a passenger vehicle type or an electric vehicle type hybrid vehicle has been described. However, the present invention is not limited to this. The present invention is also applicable to other “vehicles” such as trucks, motorcycles, trains and the like.
[0032]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a hybrid vehicle capable of operating and stopping the generator more appropriately according to the usage mode of the vehicle.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a hybrid vehicle in an embodiment.
FIG. 2 is a flowchart showing a procedure of control processing in a case where “the number of revolutions of a traveling motor” and “the charging state of a charger” are monitored by the ECU.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle 3 ... Charger 4 ... ECU (control means)
5 ... System start switch 6 ... Changeover switch (switching means)
DESCRIPTION OF SYMBOLS 10 ... Battery 11 ... Traveling motor 13 ... Voltage detector 17 ... Speed detector 20 ... Engine 21 ... Generator

Claims (3)

An engine, a generator driven by the engine to generate electric power, a battery for storing electric power generated by the electric generator, a traveling motor operated by power supply from the battery, and a remaining capacity of the battery Control means for controlling the power generation of the generator to maintain the level, and a hybrid vehicle comprising:
A switching means for switching the power generation by the generator between the power generation mode and the no power generation mode is provided, and when the switching means is switched to the no power generation mode, the control means stops the power generation by the generator regardless of the battery capacity. A hybrid vehicle characterized by that. The hybrid vehicle according to claim 1,
A traveling state detecting means for detecting whether or not the vehicle is traveling;
A hybrid vehicle characterized in that power generation by the generator is stopped when the switching means is switched to the power generation mode and the travel state detection means detects that the vehicle is not traveling. A hybrid vehicle according to claim 1 or claim 2,
Charge state detection means for detecting whether or not a charger for charging power from the outside to the battery is being charged,
A hybrid vehicle characterized in that power generation by the generator is stopped when the switching means is switched to the power generation mode and the charging state detection means detects that the charger is being charged.

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