JP2004182171A - Vehicle control device - Google Patents

Abstract

A control device for an internal combustion engine that prevents deterioration in drivability due to a decrease in the supercharged amount of a turbocharger due to a decrease in the amount of power stored in a power storage device.
An electric turbo (3) drives an electric motor with electricity supplied from a battery (5) to supply compressed air to an engine (2). The controller 4 controls the supercharging amount of the electric turbo 3 and the gear ratio of the transmission 6 based on the charge amount of the battery 5. When the charge amount of the battery 5 is small, the speed ratio of the transmission 6 is increased and the supercharging amount of the electric turbo 3 is reduced. Conversely, when the charge amount of the battery 5 is large, the gear ratio of the transmission 6 is reduced, and the supercharging amount of the electric turbo 3 is increased.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle control device that controls an internal combustion engine and a transmission in a vehicle.
[0002]
[Prior art]
The turbocharger supercharges the intake air of the engine in order to obtain high-output engine output characteristics.However, the turbocharger has a problem that the boost pressure does not rise well in a low rotation range where the exhaust energy is small. is there. In order to improve this point, an electric motor (motor) is incorporated in a turbine or a compressor of the turbocharger, and a turbocharger with an electric motor that obtains a desired supercharging pressure by forcibly driving the turbine or the compressor with the electric motor has been developed. . In the case of an electric motor, the electric motor can also function as a generator that converts energy given to the electric motor into electric energy. Therefore, when the driving force of the electric motor is not required during deceleration operation or the like, the electric motor incorporated in the turbocharger generates electric power by using exhaust gas from the engine and recovers exhaust energy as electric energy.
[0003]
As a control device of this type of turbocharger, there is, for example, a control device of a turbocharger with a rotating electric machine and a charging mechanism disclosed in Japanese Patent Application Laid-Open No. 6-257452. In this control device, an opening / closing means is provided between the battery and the generator of the rotating electric machine, and when the rotating electric machine is electrically driven, the opening / closing means is opened to supply a low voltage to the auxiliary equipment from the battery having a reduced charged amount. In the power generation operation, the opening / closing means is closed to appropriately charge the electric machine from the generator to the battery.
[0004]
[Patent Document 1]
JP-A-6-257452 [0005]
[Problems to be solved by the invention]
However, in the control device described in Patent Document 1, the drive amount of the electric motor is determined regardless of the amount of charge of the battery (the amount of charge of the power storage device). For this reason, when the charge amount of the battery decreases, the supercharging amount of the turbocharger with electric motor decreases even if the accelerator opening of the driver is constant, and in this state, the engine torque decreases and the vehicle torque decreases. Drive torque decreases. This reduction in the driving torque increases the accelerator opening to request the driver to increase the torque, and does not return until the downshift is performed in the transmission. In this case, depending on the amount of charge of the battery, even when the accelerator opening is the same, the feeling of acceleration is different, and there is a problem that drivability is deteriorated.
[0006]
Therefore, an object of the present invention is to provide a control device for an internal combustion engine that prevents deterioration in drivability due to a decrease in the supercharged amount of a turbocharger due to a decrease in the amount of power stored in a power storage device.
[0007]
[Means for Solving the Problems]
A vehicle control device according to the present invention that has solved the above-described problems includes a turbocharger to which an electric motor is attached, and drives the electric motor with electricity supplied from a power storage device connected to the electric motor, while driving an electric machine generated by the electric motor. A control device for an internal combustion engine having a turbocharger with a motor that charges a power storage device, wherein a control unit controls a speed ratio of a transmission connected to the internal combustion engine and a supercharging amount of the turbocharger based on a power storage amount in the power storage device. It is.
[0008]
In the control device for an internal combustion engine according to the present invention, the supercharging amount of the turbocharger is controlled based on the charged amount of the power storage device, and at the same time, the speed ratio of the transmission provided in the internal combustion engine is controlled. . Therefore, it is possible to select a gear ratio that matches the amount of power stored in the power storage device, so that good drivability can be maintained regardless of the amount of power stored in the power storage device.
[0009]
Here, in a case where the charged amount of the power storage device is equal to or less than a predetermined lower limit, it is preferable to increase the speed ratio of the transmission and reduce the supercharging amount of the turbocharger.
[0010]
As described above, when the charged amount of the power storage device becomes equal to or less than the lower limit value, the speed ratio of the transmission is increased, and the supercharging amount of the turbocharger is reduced, so that the engine output torque can be kept constant. Therefore, stable drivability can be maintained. In addition, since the amount of electricity extracted from the power storage device with a small power storage amount is small, it is possible to appropriately encourage the power storage device to recover from the power storage amount that is slightly lacking.
[0011]
Further, when the charge amount of the power storage device is equal to or more than a predetermined upper limit value, it is preferable that a speed ratio of the transmission is reduced and a supercharge amount of the turbocharger is increased.
[0012]
As described above, when the charged amount of the power storage device is equal to or less than the upper limit value, the speed ratio of the transmission is reduced, and the turbocharger is increased, so that the engine output torque can be kept constant. Therefore, stable drivability can be maintained. Further, since the amount of electricity extracted from the power storage device with a small amount of stored power is reduced, the surplus electricity of the power storage device can be preferably used.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
FIG. 1 is a configuration diagram of a vehicle including a control device according to an embodiment of the present invention. As shown in FIG. 1, a vehicle 1 according to the present embodiment includes an engine 2 that is an internal combustion engine. The engine 2 is provided with a turbocharger with electric motor (hereinafter referred to as “electric turbo”) 3 having a turbocharger with an electric motor attached thereto, and supplies compressed air to the engine 2 as appropriate. The electric turbo 3 is provided with a motor (not shown), and a battery 5 as a power storage device is connected to the motor via a controller 4 as a control device. Then, based on the control signal of the controller 4, the current from the battery 5 is supplied to the electric motor of the electric turbo 3 to drive the electric turbo 3, or the electric motor generated by the electric motor functioning as a generator at the time of regeneration Charging.
[0015]
Further, a transmission 6 including an automatic continuously variable transmission (CVT) is connected to the engine 2, and a drive shaft 7 is connected to the transmission 6. Further, front wheels 8, which are driving wheels, are attached to both ends of the drive shaft 7, and the output of the engine 2 is transmitted to the front wheels 8, 8 via the drive shaft 7 after being shifted by the transmission 6. A control signal from the controller 4 is output to the transmission 6, and the speed ratio of the transmission 6 is controlled based on the control signal.
[0016]
Further, a current sensor 9 is attached to the battery 5, and detects the magnitude of the current supplied from the battery 5 and is in the controller 4. The controller 4 obtains the amount of charge of the battery 5 (the amount of power stored in the power storage device) based on the magnitude of the current supplied from the battery 5. A vehicle speed sensor 12 is provided on a rear shaft 11 on which the rear wheels 10, 10 on the rear side are mounted, and detects a vehicle speed from the rotation of the rear shaft 11 and outputs the detected vehicle speed to the controller 4. Further, an accelerator opening sensor 13 is attached to an accelerator pedal (not shown), and detects the accelerator opening when the driver operates the accelerator, and outputs the detected accelerator opening to the controller 4. The engine 2 is provided with a rotation speed sensor (not shown) for detecting the rotation speed of the engine 2, and outputs the detected engine rotation speed to the controller 4.
[0017]
Control performed by the vehicle control device according to the present embodiment having the above configuration will be described with reference to FIGS.
[0018]
First, the controller 4 acquires the traveling state of the vehicle 1 (S1). The traveling state of the vehicle 1 includes the vehicle speed of the vehicle 1 output from the vehicle speed sensor 12, the rotation speed of the engine 2 output from the rotation speed sensor, the accelerator opening output from the accelerator opening sensor 13, and the shift of the transmission 6. It is calculated based on the ratio.
[0019]
Next, a required vehicle driving force and a required engine power are calculated (S2). The vehicle required driving force is calculated based on the amount of change in the accelerator opening of the accelerator pedal operated by the driver. Further, the required engine power is calculated based on a difference between the vehicle required driving force obtained here and the traveling state of the vehicle 1 calculated in step S1.
[0020]
After the required engine power is calculated, subsequently, the required power of the electric turbo is calculated (S3). The required power of the electric turbocharger is calculated based on the required power of the engine calculated in step S3, and when the required power of the electric turbo is required, a current is supplied from the battery 5 to the electric motor in the electric turbo3, The electric motor of the electric turbo is driven to operate the turbocharger.
[0021]
Then, it is determined whether the required power of the electric turbo is not 0 (S4). As a result, when it is determined that the required power of the electric turbo is 0, the process returns to step 1 and repeats the same operation without changing the transmission gear ratio. On the other hand, when it is determined that the required power of the electric turbo is not 0, the upper limit power of the electric turbo is calculated (S5). The upper limit power of the electric turbo is determined by the charge amount of the battery 5. The controller 4 calculates the charge amount of the battery 5 from the magnitude of the current supplied from the battery 5 based on the current value output from the current sensor 9. Then, the upper limit power of the electric turbo is calculated from the calculated charge amount.
[0022]
After calculating the upper limit power of the electric turbo, it is determined whether the required power of the electric turbo is larger than the upper limit power of the electric turbo limited to the charge amount of the battery 5 (S6). As a result, when the required power of the electric turbo 3 is equal to or less than the upper limit power of the electric turbo 3 limited to the charge amount of the battery 5, there is a margin in the charge amount of the battery 5, and the electric turbo 3 is reduced to the required power. Not only can it be operated together, but there is also room for the power that can be output from the electric turbo 3. Therefore, the supercharging amount of the electric turbo 3 is increased, and the gear ratio (gear ratio) of the transmission 6 is moved to the high side to lower the engine speed. By performing such control, a decrease in the torque output by the engine 2 itself due to an increase in the supercharging amount of the electric turbo 3 can be compensated for, and the surplus power reception amount of the battery 5 can be effectively consumed.
[0023]
When the required power of the electric turbo 3 exceeds the upper limit power of the electric turbo 3 limited to the charge amount of the battery 5, a current for providing the power required by the electric turbo 3 is supplied to the electric turbo 3. Can not be done. In this state, the required power of the electric turbo 3 cannot be satisfied, so that smooth acceleration and running are hindered and drivability is reduced. Therefore, when the required power of the electric turbo 3 exceeds the upper limit power of the electric turbo 3 limited to the charge amount of the battery 5, the controller 4 reduces the supercharging amount of the electric turbo 3 and The gear ratio is shifted to the low side, and control is performed so that a large torque is applied. As described above, when the current supplied from the battery 5 is small and the power provided from the electric turbo 3 is insufficient, the gear ratio of the transmission 6 is increased to increase the torque, and the discharge amount of the battery 5 is reduced. Suppress. In this way, a sufficient torque can be given to the front wheels 8, 8, so that drivability can be prevented from lowering, and a decrease in the charge amount of the battery 5 can be suppressed. , The amount of charge of the battery 5 is restored. The ratio of the gear ratio at the time of increasing the gear ratio is calculated based on the difference between the upper limit power of the electric turbo 3 limited to the insufficient charge amount of the battery 5 with respect to the required power of the electric turbo.
[0024]
When the gear ratio of the transmission 6 is shifted to the low side to increase the engine torque applied to the front wheels 8, 8, the process returns to FIG. 1, and the running state of the vehicle 1 is detected again, and the same processing is repeated.
[0025]
Thus, by adjusting the supercharging amount of the electric turbo 3 and the gear ratio of the transmission 6 according to the charge amount of the battery 5, if the accelerator opening of the accelerator operated by the driver is constant, By controlling the gear ratio of the transmission 6 and the supercharging amount of the electric turbo 3, the driving force of the vehicle 1 can be kept constant. Therefore, the driving state of the vehicle can be controlled so as not to cause deterioration of drivability. In addition, since the amount of power that can be used by the electric turbo 3 is limited according to the amount of charge / discharge of the battery 5, the charge amount of the battery 5 can be kept stable, and the battery 5 can be used stably. be able to.
[0026]
Next, the effect of the control according to the present invention will be described with reference to FIG.
[0027]
FIG. 3 is a graph showing the relationship between the engine speed and the engine output. FIG. 3 shows a maximum output line L when there is no supercharging by the electric turbo, and an output increase region F due to the electric turbocharging.
[0028]
Now, it is assumed that the relationship between the engine speed and the engine output torque is at the position of point A, for example. From this state, consider depressing the accelerator to increase the engine speed to the position of point C. Here, in the conventional control of the electric turbo, when the accelerator is depressed, the electric turbo is activated and the charged amount of the battery is rapidly reduced. For this reason, the output torque of the engine temporarily drops to the position of point B. Thereafter, by shifting down the transmission, the engine output torque gradually increases with an increase in the engine speed, and moves to the position of point C. Since the engine output torque fluctuates in this way, drivability is reduced.
[0029]
On the other hand, in the control according to the present invention, when the charge amount of the battery 5 is small when moving from the point A to the point C, the engine speed is increased by downshifting the transmission 6 and the electric turbo 3 Reduce supercharging. For this reason, since the output power of the electric turbo 3 is reduced, the engine speed can be increased while the engine output torque is kept constant. Moreover, it is possible to prevent an excessive load from being applied to the battery 5 having a small charge amount.
[0030]
Conversely, when moving from the point A to the point D when the charge amount of the battery 5 is large, the engine 6 is shifted down by the shift up of the transmission 6 and the supercharged amount of the electric turbo 3 is increased. For this reason, since the output power of the electric turbo 3 increases, the engine speed can be reduced while the engine output torque is kept constant. In addition, the surplus charging electricity of the battery 5 can be effectively used.
[0031]
As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to the above embodiments. For example, in the above-described embodiment, the threshold value for increasing / decreasing the gear ratio of the transmission 6 is set to the same value, while the supercharging amount of the electric turbo 3 is reduced / increased. On the other hand, while reducing the supercharging amount of the electric turbo 3, the lower limit value for increasing the gear ratio of the transmission 6, the supercharging amount of the electric turbo 3 is increased, and the gear ratio of the transmission 6 is reduced. And the upper limit value to be set individually.
[0032]
Further, in the above embodiment, an automatic continuously variable transmission is used as the transmission, but a so-called automatic transmission may be used.
[0033]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the drivability from being deteriorated due to a decrease in the supercharged amount of the turbocharger due to a decrease in the charge amount of the power storage device, and further to reduce the charge / discharge amount of the power storage device An internal combustion engine control device that can be stabilized can be provided.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating an outline of a vehicle including a control device according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a control procedure performed by a control device according to the embodiment of the present invention.
FIG. 3 is a graph showing a relationship between an engine speed and an engine output.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine, 3 ... Electric turbo, 4 ... Controller, 5 ... Battery, 6 ... Transmission, 7 ... Drive shaft, 8 ... Front wheel, 9 ... Current sensor, 10 ... Rear wheel, 11 ... Rear shaft, 12 ... Vehicle speed sensor, 13 ... Accelerator opening sensor.

Claims (3)

A turbocharger with a motor is provided. In the control device for the internal combustion engine having
A vehicle control device for controlling a speed ratio of a transmission connected to the internal combustion engine and a supercharging amount of the turbocharger based on a charged amount in the power storage device. 2. The vehicle control device according to claim 1, wherein when a charge amount of the power storage device is equal to or less than a predetermined lower limit value, control is performed to increase a speed ratio of the transmission and reduce a supercharging amount of the turbocharger. . 3. The vehicle control device according to claim 1, wherein when a charge amount of the power storage device is equal to or more than a predetermined upper limit value, a speed ratio of the transmission is reduced and a supercharge amount of the turbocharger is increased. 4. .

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