JP2001095102A - Series hybrid motor-driven vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a series hybrid motor-driven vehicle which can reduce the engine sound and vibrations when the car body of the stock is stopped or runs at a low speed. SOLUTION: A series hybrid motor-driven rolling stock is provided with a vehicle speed sensor 15 which detects the running speed of the vehicle, a target number-of-revolution value outputting means (output request generating section 18) which outputs the target number of revolutions of an engine corresponding to the vehicle speed, and a number-of-revolution detecting means (number-of-revoltion detector 11) which detects the number of revolutions of the engine. The vehicle is also provided with an engine control means (generated energy control amplifier 19) which controls the detected number-of-revolution value of the engine so that the value may become coincident with the number-of- revoltion value of the engine. The target number-of-revolution outputting value means which outputs the target number-of-revolution value of the engine is constituted so that the target number-of-revolution value outputted from the means may become larger as the vehicle speed increases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a series hybrid electric vehicle provided with a charging device for driving wheels by a motor and charging a battery by an engine driven generator.

[0002]

2. Description of the Related Art Conventionally, this type of electric vehicle charging device has
The engine is started when the remaining capacity of the battery that supplies power to the motor decreases, and the battery is charged with the power generated by the generator driven by the engine. The engine speed is controlled according to the remaining capacity of the battery. The control of the engine speed is performed irrespective of the vehicle speed.

[0003]

In the conventional electric vehicle configured as described above, in a state where the remaining capacity of the battery is low, even when the vehicle body is stopped by a signal, for example, the engine is not operated. Spin at high speed. For this reason, compared to a vehicle that drives wheels by an engine, engine noise during stoppage or low-speed running and vibration accompanying driving are significantly increased. In general, when a person who is accustomed to an engine-driven vehicle drives this kind of vehicle, the engine rotates at a high speed when stopped or running at a low speed, giving a sense of incongruity.

The present invention has been made in order to solve such problems, and a series hybrid system capable of reducing engine noise and vibration when the vehicle body is stopped or running at low speed. It is an object to provide an electric vehicle.

[0005]

In order to achieve this object, a series hybrid electric vehicle according to the present invention comprises:
A vehicle speed sensor for detecting a vehicle speed, a target engine speed value output unit for outputting a target engine speed corresponding to the vehicle speed detected by the vehicle speed sensor, an engine speed detection unit, and an engine speed by the engine speed detection unit Engine control means for controlling the detected value to be equal to the target engine speed value, wherein the target engine speed value output means is configured to increase the output target engine speed value as the vehicle speed increases. Things. According to the present invention, the engine speed is reduced when the vehicle is stopped or running at low speed, and the battery is charged by operating the engine when running at high speed.

A series hybrid electric vehicle according to a second aspect of the present invention is the series hybrid electric vehicle according to the first aspect, wherein the engine control means controls the engine speed to exceed a predetermined engine starting speed. When the vehicle speed falls below a predetermined engine stop speed, the engine is stopped. According to the present invention, the engine stops when the vehicle is stopped or when the vehicle speed is lower than the set vehicle speed, and engine noise and vibration are not generated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a series hybrid electric vehicle according to the present invention will be described below in detail with reference to FIGS. Here, an embodiment in which the present invention is applied to an electrically assisted bicycle that assists human power with the power of a motor will be described. FIG. 1 is a block diagram showing a configuration of a charging system of a series hybrid electric vehicle according to the present invention;
FIG. 2 is a flowchart for explaining the operation at the time of charging,
FIG. 3 is a flowchart for explaining the operation at the time of mode determination, FIG. 4 is a flowchart for explaining the operation of the target charging power detection means, and FIG. 5 is a graph showing the relationship between the vehicle speed and the amount of power generation. 6 is a graph for obtaining the engine speed from the vehicle speed, FIG. 7 is a graph for obtaining the maximum power generation from the remaining capacity of the battery, and FIG. 8 is a forcible reduction of the power generation output command based on the battery temperature. It is a graph for calculating an amount.

In these figures, the reference numeral 1 designates an electric assist bicycle according to this embodiment. The electric assisted bicycle 1 has a force (stepping force) for depressing the pedal A,
The resultant of the power of the motor 2 is transmitted to the rear wheels 3 by the power transmission device B.
And drive the rear wheel 3 to travel. The power of the motor 2 is increased and decreased in proportion to the pedaling force. When the human power due to the treading force is set to 1, the power of the motor 2 can be freely set to 2, 3 or 0.7, 0.5, etc., but is set to 1 here. In addition, this electric assist bicycle 1
Is equipped with a charging device 6 for charging a battery 4 for supplying power to the motor 2 by an engine-driven motor generator 5 and for supplying power to the motor 2, and adopts a series hybrid structure. The motor 2, the motor generator 5, and the engine 7 are formed as one unit as a power unit C.

The motor generator 5 has both functions of a motor and a generator, is used as a starter motor when starting the engine 7, and generates electric power when charging the battery 4 or supplying power to the motor 2. Used as a machine. An inverter is connected between the motor generator 5 and the battery 4.
With the converter 8 interposed, the inverter / converter 8
A circuit is used for switching the mode of use of the motor generator 5 by the current control amplifier 9 and the speed control amplifier 10 connected to. The output value (speed feedback value) of the rotation speed detector 11 for detecting the rotation speed of the motor generator 5 is input to the speed control amplifier 10, and the current value (current) flowing through the motor generator 5 is input to the current control amplifier 9. Feedback value). These amplifiers 9, 10
Controls the current flowing through the inverter / converter 8 based on a command value sent from the mode determination unit 12 described later. The command value is sent when the engine is started or stopped, and when the engine is in a steady operation. When the command value for starting the engine is input to the speed control amplifier 10, the inverter
Electric power is supplied from the converter 8 to the motor generator 5 so that the motor generator 5 functions as a starter motor. At this time, the current control amplifier 9 controls the current flowing through the motor generator 5 by feedback control. When a command value for stopping the engine is input from the mode determining unit 12, the command is transmitted to the actuator driving unit 20, and the ignition system of the engine is cut off. When the engine speed is reduced by the ignition cut and becomes equal to or less than the set engine speed, the current flowing through the inverter / converter 8 is cut off again until the engine start command value is input to the speed control amplifier 10, and the battery power is used. This prevents the motor generator 5 from rotating.

When a command value for steady-state operation is input, a generator speed corresponding to generator speed data transmitted from a vehicle speed-generator speed map reference unit indicated by reference numeral 13 in FIG. The inverter / converter 8 is controlled so that the motor generator 5 rotates. The engine 7 is connected to the motor generator 5 (here, it is directly connected, but a speed reduction device or a speed increasing device may be interposed).
As a result, this is equivalent to feedback control of the engine speed. The vehicle speed-generator rotation speed map reference unit 13 reads the target rotation speed of the motor generator 5 corresponding to the current vehicle speed from the vehicle speed-rotation speed command value map shown in FIG. 6, and performs speed control as generator rotation speed data. Send it to the amplifier 10. In FIG. 6, when the vehicle speed increases and reaches the vehicle speed v1, the engine 7 is started by the motor generator 5 functioning as a starter motor, and the motor generator 5
The target generator rotation speed is set to r1 so that the engine 7 directly connected to the engine 7 is rotated at the rotation speed r1. As the vehicle speed increases, the target generator speed is gradually increased. When the vehicle speed reaches v2, the motor generator 5 starts generating power and the target generator speed is set to r2. Further, when the vehicle speed becomes v2 or higher, the target generator rotation speed is increased at a predetermined rate with respect to the increase in the vehicle speed. To be maintained. The graph showing the command value of the target generator speed is f. When the vehicle speed decreases, the target generator rotation speed is reduced according to the graph f. When the vehicle speed reaches v2, the motor generator 5 stops generating power, and when the vehicle speed further decreases and reaches the vehicle speed v1, the engine 7 is stopped.
On the other hand, when the remaining capacity of the battery 4 falls below a predetermined value,
In order for the motor generator 5 to start power generation at a small vehicle speed of v2 ', the target generator speed is set to r2. The rate of increase of the target generator speed with respect to the increase of the vehicle speed is set to be larger than when the remaining capacity of the battery 4 is equal to or higher than a predetermined value, and the vehicle speed v3 'reaching a certain target generator speed r3 is the vehicle speed v3. Set smaller. The graph showing the command value of the target generator speed at this time is f '. When the vehicle speed decreases, the target generator speed is set to decrease according to the graph f 'in the same manner as described above. This map is stored in the memory 14 in advance. The vehicle speed is
Detected by the vehicle speed sensor 15.

The engine 7 has a fuel supply valve and a throttle valve (not shown) connected to electric actuators 16 and 1.
7 for driving. These actuators 16 and 17 and an engine ignition device (not shown)
Is set so that the output request value (target charging power) generated by the output request generation unit indicated by reference numeral 18 in FIG. 1 matches the generated power of the motor generator 5 (charging power supplied to the battery 4). Control. The output request generation unit 18 receives the data of the remaining battery capacity from the remaining battery power detection unit 22, and derives a generator output command value from the map of FIG. The output request generation unit 18 further sends a value obtained by subtracting the forced reduction amount derived from the map of FIG. 8 based on the battery temperature from the command value to the power generation amount control amplifier 19 as an output request signal. The power generation amount control amplifier 19 performs PI control so that the difference between the battery output feedback values is eliminated using the output request value sent from the output request generation unit 18 as a command value, and sends a control signal to the actuator drive unit 20. The actuator drive unit 20 drives the two actuators 16, 17 and the ignition device according to the control signal. The battery output feedback value is calculated by the output calculator 21 based on the voltage between the terminals of the battery 4 and the charge / discharge current, and sent to the power generation control amplifier 19. That is, the power generation control amplifier 19 controls the charging device 6 so that the charging power matches the target charging power. The output request generation unit 18 constitutes a target charging power detection unit according to the present invention, and the power generation amount control amplifier 19 constitutes a charging control unit according to the present invention.

When the output request generator 18 generates an output request signal, in this embodiment, the remaining capacity (SOC) of the battery 4 is maintained at 70% in order to prevent the battery 4 from being overcharged. Like that. The remaining capacity is obtained by the battery remaining amount detection unit 22 based on the voltage between the terminals of the battery 4, the charge / discharge current, and the battery temperature. If the remaining capacity is less than 70%, the charging power is set based on the remaining battery capacity-power generation output command value map shown in FIG. This map indicates the amount of chargeable electric power with respect to the remaining capacity, and is stored in the memory 14 in advance.

The mode determining section 12 divides the driving state of the electric assisted bicycle 1 into a plurality of driving modes and sends various command values to the speed control amplifier 10 and the output request generating section 18 for each mode. The data input to the mode determination unit 12 includes the vehicle speed data detected by the vehicle speed sensor 15, the remaining capacity of the battery 4 detected by the battery remaining amount detection unit 22, and the rotation speed detector 11 of the motor generator 5. And the stand position data detected by the stand sensor 23. The stand sensor 23 detects whether the stand 24 is being used.

Next, the operation of the electric assisted bicycle 1 constructed as described above will be described with reference to the flowcharts shown in FIGS. When a not-shown main switch (power switch) of the electric assist bicycle 1 is turned on, first, step S1 in the flowchart shown in FIG.
In step S2, after waiting 5 ms in step S2, the mode determining unit 12 performs mode determination in step S3.

The mode determination is performed as shown in the flowchart of FIG. First, as shown in step 100 of the figure, it is determined whether or not the stand 24 is in use and whether or not the remaining capacity of the battery 4 exceeds 80%. If any one of these conditions is satisfied, YES is determined and the routine proceeds to step 101.
In step 101, the rotation speed (rotation speed) of the motor generator 5 is set to 0, the opening of the fuel supply valve and the throttle valve of the engine 7 is set to fully closed, and the ignition device is turned off.
Set to F. Then, the routine proceeds to step 102, where the current mode is set to the engine stop mode. If the determination in step 100 is NO, it is determined in step 103 whether the current mode is the engine stop mode. If the determination is YES, the process proceeds to step 104, and the determination is NO. In this case, the process proceeds to step 105.
In step 104, the rotation speed of the motor generator 5 is set to 0, the opening of the fuel supply valve and the throttle valve of the engine 7 is set to fully closed, and the ignition device is set to OFF. Then, in step 106, it is determined whether or not the current vehicle speed is higher than the engine starting speed. When the determination is YES, the process proceeds to step 107, and when the determination is NO, the process proceeds to step 102. Step 105
Then, it is determined whether or not the current mode is the engine starting mode.

If YES is determined in step 105, the process proceeds to step 107, and if NO is determined, the process proceeds to step 108. In step 107, the rotation speed of the motor generator 5 is set to the rotation speed at the time of starting the engine, the fuel supply valve and the ignition device of the engine 7 are set to the ON state, and the opening of the throttle valve is set to the opening at the time of starting. Set to. Thereafter, the process proceeds to step 109, where it is determined whether or not power is being generated by detecting the current flowing through the motor generator 5.
Step 110 if the motor generator 5 is generating power.
Then, if the motor generator 5 is functioning as a starter motor, the routine proceeds to step 111, where the current mode is set to the engine starting mode.

In step 108, it is determined whether or not the current mode is the engine steady mode. If the determination is YES, the process proceeds to step 110, and if the determination is NO, the process proceeds to step 112. In step 110, the rotation speed of the motor generator 5 is set to the rotation speed based on the vehicle speed-motor rotation speed map shown in FIG. 6, the fuel supply valve and the ignition device of the engine 7 are set to the ON state, and the throttle valve Set the opening to the opening corresponding to the required output value. Thereafter, in step 113, it is determined whether or not the current vehicle speed is lower than the engine stop speed. Step 11
If YES is determined in step 3, the process proceeds to step 114, and if NO is determined, the process proceeds to step 115 to set the current mode to the steady mode.

In step 112, it is determined whether or not the current mode is the engine stopped mode. If the result of this determination is YES, the process proceeds to step 114, where NO
If so, the process proceeds to step 116. In step 114, the number of revolutions of the motor generator 5 is set to 0, the opening of the fuel supply valve and the throttle valve is set to fully closed, and the ignition device is set to OFF. Then, the routine proceeds to step 117, where the current mode is set to the engine stopped mode. In step 116, an abnormal process is performed. In this abnormality processing, all the actuators and the ignition device of the charging device 6 are turned off, and an alarm lamp (not shown) provided on the vehicle body is turned on. After performing the abnormality processing control in this way, in step 118, the current mode is set to the abnormality mode.

Step 102 in the flowchart of FIG.
After setting the current mode in steps 111, 115, 117, and 118, the process proceeds to step S4 in the flowchart of FIG.
Controls the speed (charging power) of the motor generator 5. Next, in step S5, the output request generator 18 obtains an output request value. The output request value is obtained as shown in the flowchart of FIG. First, it is determined in step 200 of the flowchart shown in FIG. 4 whether a command to stop the engine 7 has been issued. If it is determined as YES,
Proceeding to step 201, the output required value of the motor generator 5 is set to 0, and if it is determined as NO, step 20 is executed.
Proceeding to 2, it is determined whether the battery temperature is between the upper limit and the lower limit.

If the determination in step 202 is NO, the process proceeds to step 201, and if the determination is YES, the process proceeds to step 203 to determine whether the remaining capacity of the battery 4 exceeds 70%. . If the result of this determination is YES, the operation proceeds to step 201, and if it is NO, the operation proceeds to step 204. In step 204, the output required value of the motor generator 5 is set to a value determined based on the remaining battery capacity-power generation output command value map shown in FIG.

After setting the output request value in this way, FIG.
In step S6 of the flowchart shown in FIG. 7, the power generation amount control amplifier 19 obtains control values such as the opening degrees of the fuel supply valve and the throttle valve of the engine, the ignition timing of the ignition device, and the like with the output required value as a target. A control signal is sent to the actuator drive unit 20 to make the actuator 1
6, 17 and the ignition device are controlled. Then, step S2
And the above control is repeated.

By controlling the charging device 6 as described above, the engine speed and the power generation amount change as shown in FIG. In FIG. 5, the horizontal axis represents time, and the vertical axis represents engine speed, vehicle speed, power generation, and power consumption. As can be seen from the figure, the engine 7 is operated in a state where the vehicle speed is higher than the engine start / stop speed, and the engine speed increases or decreases in accordance with the vehicle speed. That is, the engine speed relatively decreases when traveling at low speed, and relatively increases when traveling at high speed. The amount of power generated by the motor generator 5 is controlled based on the remaining battery level without any interference with the engine speed. The curve indicating the power consumption is wavy because the power of the motor 2 assists when the pedal is depressed, and the output of the motor 2 increases and decreases in a pulsating manner.

Therefore, the electric assisted bicycle 1 has an engine-driven charging system such that the rotation speed of the motor generator 5 matches the target engine rotation speed set to increase as the vehicle speed increases. Since the device 6 is controlled, the engine speed is reduced when the vehicle is stopped or running at low speed, and the engine 7 is operated and the battery 4 is charged when running at high speed. For this reason, engine noise and vibration at the time of stopping or running at low speed can be reduced. Further, the configuration is such that the engine 7 is started when the vehicle speed exceeds a predetermined engine start speed and the engine 7 is stopped when the vehicle speed falls below the predetermined engine stop speed. When the vehicle speed is lower than the set vehicle speed, the engine 7 stops and no engine noise or vibration is generated.

In the above-described embodiment, an example in which the present invention is applied to the electric assist bicycle 1 has been described. However, the present invention is not limited to a series hybrid electric vehicle using a motor as a power source. For example, the present invention can be applied to any vehicle.

[0025]

As described above, according to the present invention, the engine speed is reduced when the vehicle is stopped or running at low speed, and the engine is driven and the battery is charged when running at high speed. The engine noise and vibration at the time of running and at low speed can be reduced. For this reason, even if a person unfamiliar with this kind of electric vehicle drives, there is no uncomfortable feeling.

According to the second aspect of the present invention, when stopping,
The engine stops when the vehicle speed slows below the set vehicle speed,
Since no engine noise or vibration is generated, a more quiet series hybrid electric vehicle can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a charging system of a series hybrid electric vehicle according to the present invention.

FIG. 2 is a flowchart illustrating an operation during charging.

FIG. 3 is a flowchart illustrating an operation at the time of mode determination.

FIG. 4 is a flowchart for explaining the operation of a target charging power detection means.

FIG. 5 is a graph showing a relationship between a vehicle speed and a power generation amount.

FIG. 6 is a graph showing a map for obtaining an engine speed from a vehicle speed.

FIG. 7 is a graph showing a map for obtaining the maximum generated power from the remaining capacity of the battery.

FIG. 8 is a graph for obtaining a forced reduction amount of a power generation output command based on a battery temperature.

[Explanation of symbols]

1: electric assist bicycle, 2: motor, 4: battery, 5
... Motor generator, 6 ... Charging device, 7 ... Engine, 15 ...
Vehicle speed sensor, 18: output request generation unit, 19: power generation amount control amplifier.

Claims (2)

[Claims] In a series hybrid electric vehicle provided with a charging device for driving a wheel by a motor and charging a battery by an engine driven generator, a vehicle speed sensor for detecting a vehicle speed, and a vehicle speed detected by the vehicle speed sensor. A target engine speed output unit for outputting a corresponding target engine speed, an engine speed detection unit, and an engine for controlling an engine speed detection value by the engine speed detection unit to match the target engine speed. A series hybrid electric vehicle comprising: a control unit; and wherein the target engine speed output unit increases the target engine speed output as the vehicle speed increases. 2. The series hybrid electric vehicle according to claim 1, wherein the engine control means starts the engine when the vehicle speed exceeds a predetermined engine start speed, and the engine speed decreases below a predetermined engine stop speed. A series hybrid electric vehicle, characterized in that the engine is stopped when the vehicle is in a stop condition.