JP3296162B2 - Control device for hybrid vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for a hybrid vehicle having an internal combustion engine and an electric motor as power sources.

[0002]

2. Description of the Related Art Conventionally, a hybrid vehicle having an internal combustion engine and an electric motor as a power source of the vehicle is disclosed in Japanese Patent Laid-Open No. 5-2 / 1993.
No. 60610 proposes this.

This includes an electric motor connected to a drive shaft of an internal combustion engine, a power storage device, and a control circuit for controlling torque of the electric motor. When the vehicle is accelerating, electric energy is supplied from the power storage device to the electric motor. This assists the output of the internal combustion engine, performs regenerative braking using the electric motor as a generator during deceleration and braking, and charges the power storage device with the generated electric energy.

In this way, the kinetic energy of the vehicle during the deceleration or braking is recovered as electric energy, and the kinetic energy is used to improve the acceleration performance of the vehicle during acceleration, thereby reducing fuel consumption of the internal combustion engine. ing.

[0005]

However, when the vehicle is decelerated or braked, the engine brake of the internal combustion engine operates, and much of the kinetic energy of the vehicle is consumed as engine brake (pumping loss), and the electric power is relatively reduced. The amount of regenerative braking by the motor decreases. In other words, energy that is wasted by the engine brake of the internal combustion engine cannot be recovered, and it is inevitable that the regenerative efficiency of the electric motor is reduced accordingly.

The present invention has been proposed in order to solve such a problem. Under operating conditions such as deceleration by applying an engine brake, energy consumed as a pumping loss is recovered as electric energy. The purpose is to perform efficient hybrid operation.

[0007]

[0008]

A first invention, as shown in FIG. 20, comprises an electric motor connected to a drive shaft of an internal combustion engine, and a power storage device connected to the electric motor. In a hybrid vehicle in which electric energy is supplied from an electric storage device to an electric motor to perform auxiliary driving, regenerative braking is performed by the electric motor at the time of deceleration and braking, and the generated electric energy is charged in the electric storage device, the internal combustion engine operates at the time of deceleration fuel. Means 51 for determining that the supply is stopped, means 54 for detecting the rotational speed of the drive shaft, and calculation of the adjustable width of the braking torque by the engine brake of the internal combustion engine at the rotational speed in the fuel supply stopped state. Means 55
Means 56 for calculating a regenerative braking torque that the electric motor can generate at the same rotational speed; and a regenerative braking torque of the electric motor such that the regenerable braking torque that can be generated is at most within the calculated adjustable width. There is provided an adjusting means 57 and an engine brake adjusting means 53 for reducing the braking torque by the engine brake of the internal combustion engine in the fuel supply stopped state by an amount corresponding to the regenerative braking torque of the electric motor.

A second invention, as shown in FIG. 21, includes an electric motor connected to a drive shaft of an internal combustion engine, and a power storage device connected to the electric motor. The internal combustion engine is in a fuel supply stop state at the time of deceleration in a hybrid vehicle that performs auxiliary driving by supplying electric energy to the vehicle and performs regenerative braking by an electric motor during deceleration and braking to charge the generated electric energy to the power storage device. 51, a means 54 for detecting the rotational speed of the drive shaft, and a means 55 for calculating the adjustable width of the braking torque by the engine brake of the internal combustion engine at the rotational speed in the fuel supply stopped state. Means 56 for calculating a regenerative braking torque that the electric motor can generate at the rotation speed, and means 58 for detecting the state of charge of the power storage device. Means for detecting the temperature of the exhaust catalyst 5
9; means 60 for calculating a regenerative rate coefficient of the electric motor based on at least one of the state of charge of the power storage device and the temperature of the exhaust catalyst; and the regenerative braking that can be generated based on the regenerative rate coefficient. Means 61 for correcting the torque, means 57 for adjusting the regenerative braking torque of the electric motor such that the corrected regenerative braking torque is at most within the calculated adjustable width, and corresponds to the regenerative braking torque of the electric motor. An engine brake adjusting means for reducing a braking torque by an engine brake of the internal combustion engine when the fuel supply is stopped.

According to a third aspect of the present invention, in the first or second aspect, the means for calculating the adjustable range of the braking torque is provided when the throttle valve at the rotational speed or the control valve of the passage bypassing the throttle valve is fully closed. Then, the adjustable width of the engine brake is calculated based on the deviation between the braking torque by the engine brake and the braking torque when the throttle valve or the control valve is fully opened.

In a fourth aspect based on the first to third aspects, the engine brake adjusting means adjusts an opening degree of a throttle valve in an intake passage or a control valve in a passage bypassing the throttle valve by applying a braking torque by an engine brake. It is configured to adjust by changing.

According to a fifth aspect of the present invention, in the first to fourth aspects, means for detecting an output torque of the internal combustion engine, and braking by an engine brake generated when the throttle valve or the control valve is fully closed in a fuel supply stopped state. Means for feedback-controlling the engine brake adjusting means so that the braking target torque obtained by subtracting the regenerative braking torque by the electric motor from the torque and the detected torque match.

[0013]

[0014]

[0015]

[0016]

According to the first aspect , the magnitude of the regenerative braking torque that can be generated by the electric motor basically depends on the rotation speed of the drive shaft at that time. Further, the adjustable width of the braking torque by the engine brake of the internal combustion engine is also determined according to the rotation speed at that time.

If the regenerative braking torque by the electric motor exceeds the adjustable range of the braking torque by the engine brake, even if the braking torque by the engine brake is reduced to the maximum, the total braking torque is accompanied by the regenerative braking. It becomes larger than the braking torque at the time of deceleration due to no engine brake, and brings a feeling of strangeness of deceleration.

Therefore, the regenerable braking torque calculated based on the rotation speed in the fuel supply stopped state is adjusted so as to be within the adjustable range of the braking torque by the engine brake, and based on this, the regenerative braking by the electric motor is performed. By doing so, the recovery efficiency of the kinetic energy at the time of deceleration is maintained at the maximum without causing a feeling of strangeness during deceleration.

In the second invention, the regenerable braking torque of the electric motor differs depending on the state of charge of the power storage device at that time. When the state of charge of the power storage device is sufficient and there is a risk of overcharging, It is better not to charge by further energy regeneration. Also, the temperature of the exhaust catalyst is low,
If the braking torque due to the engine brake is reduced by increasing the intake air amount while the fuel supply is stopped, the catalyst temperature will be further reduced, and if there is a possibility that activation will be lost, the braking torque of the engine brake will be reduced. It is better not to let it.

In view of the above, the regenerative rate coefficient is calculated based on the state of charge of the power storage device or the temperature state of the exhaust catalyst, and the braking torque that can be regenerated by the electric motor is corrected accordingly. Therefore, appropriate kinetic energy can be recovered within a range that does not impair the deterioration of the power storage device or the activation of the exhaust catalyst.

In the third aspect of the invention, the braking torque generated by the engine brake generated when the throttle valve or the control valve in the passage bypassing the throttle valve is fully closed in a state in which the fuel supply is stopped, and the throttle valve or the control valve is controlled. Since the adjustable width of the engine brake is calculated based on the deviation from the braking torque when fully opened, the braking torque by the engine brake can be adjusted most accurately.

In the fourth aspect of the present invention, as the engine brake adjusting means, the opening degree of the throttle valve or the control valve of the passage bypassing the throttle valve is controlled to adjust the magnitude of the pumping loss. Appropriate control can be performed, and no special configuration is required for the control.

According to the fifth aspect of the present invention, the feedback control is performed such that the actual output torque of the internal combustion engine in the fuel supply stopped state matches the target engine brake braking torque at that time. The combined torque of the electric motor and the regenerative braking torque exactly matches the engine brake braking torque when the throttle or the control valve is fully closed without regenerative braking, and there is no uncomfortable feeling of deceleration.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described. First, in FIG. 1, an electric motor 3 is connected to a drive shaft 4 of an internal combustion engine 1 to supply electric energy from a power storage device 6 during acceleration or the like. In response to this, the output of the internal combustion engine 1 is assisted, and regenerative braking is performed using the electric motor 3 as a generator by kinetic energy of the vehicle such as during deceleration or braking, and the generated electric energy is charged in the power storage device 6.

A motor torque control circuit 5 is provided for controlling the torque of the electric motor 3 during acceleration or deceleration.
The output torque and regenerative braking torque of the electric motor 3 are controlled based on a motor torque control signal from an electronic control unit 7 composed of a microcomputer. Note that, as the power storage device 6, a lead storage battery, a large-capacity capacitor, or the like can be used.

The intake passage 8 is provided with a throttle valve 10 whose opening is adjusted in principle by a throttle actuator 9 in accordance with the accelerator opening, and a bypass passage 11 which bypasses the throttle valve 10 has an auxiliary air amount. An AAC valve (auxiliary air amount control valve) 12 for adjusting the throttle valve is provided.
The opening of the AAC valve 12 is controlled in accordance with the operating conditions even during the regenerative rotation of the electric motor 3 by a control signal from the electronic control unit 7 as described later.

As means for detecting operating conditions and conditions of the internal combustion engine 1, a signal from a crank angle sensor 13 for detecting an engine crank angle is input to the electronic control unit 7, and further, although not shown, detects an intake air amount. Various types of sensors such as an air flow meter, a water temperature sensor for detecting an engine cooling water temperature, a temperature sensor for detecting an intake air temperature, a sensor for detecting a vehicle speed, a sensor for detecting a rotation speed of a drive shaft 4, and a sensor for detecting a temperature of an exhaust catalyst. A signal is input. The electronic control unit 7 also receives signals from a torque sensor 2 for detecting the drive torque of the drive shaft 4 for detecting the output torque of the internal combustion engine 1 and a sensor (not shown) for detecting the state of charge of the power storage device 6. To enter.

In order to detect the output torque of the internal combustion engine 1, a combustion pressure sensor is provided instead of the torque sensor 2, and the in-cylinder pressure (combustion pressure) of each cylinder is detected.
The output torque may be calculated based on this.

The electronic control unit 7 drives the electric motor 3 by supplying electric energy from the electric storage device 6 to the electric motor 3 when the vehicle is accelerating, according to the operating conditions and conditions determined based on these various signals. When the fuel supply is stopped, for example, during deceleration or braking of the vehicle, the electric motor 3 utilizes the kinetic energy of the vehicle while assisting the driving torque of the vehicle.
In order to maximize the energy recovery efficiency without changing the deceleration traveling characteristics of the vehicle, the intake air amount of the internal combustion engine 1 is controlled by rotating the
The braking torque (pumping loss) caused by the engine brake is reduced by opening and increasing the AAC valve 12 to 0, and control is performed so that the decrease corresponds to the regenerative braking torque by the electric motor 3. When the throttle valve 10 and the AAC valve 12 are opened when the fuel supply is stopped, the kinetic energy of the vehicle wastefully consumed as the engine brake is reduced, and this amount can be used as the regenerative energy of the electric motor 3, and the energy can be regenerated. Efficiency can be improved.

Hereinafter, the control operation executed by the electronic control unit 7 will be described in detail with reference to FIGS.

In FIG. 2, first, in step 1,
It is determined whether or not the running state of the vehicle is in the fuel injection stop state during deceleration of the internal combustion engine. The deceleration-time fuel injection stop state is specifically determined as shown in FIG.

That is, in Steps 21 to 23, when the vehicle speed is equal to or higher than the predetermined value, the accelerator opening is fully closed, and the rotation speed of the drive shaft is equal to or higher than the predetermined value, the deceleration-time fuel injection is stopped in Step 24. Judge that there is. If any one of them is different, it is determined that the vehicle is not in the deceleration-time fuel injection stop state, and the determination process ends. Note that this determination process may directly use the processing result regarding the fuel injection control of the internal combustion engine.

Returning to step 2 in FIG. 2, the rotational speed of the common drive shaft of the internal combustion engine and the electric motor is detected, and in step 3, the adjustable range of the braking torque by the engine brake when the internal combustion engine is decelerated is calculated.

This is specifically performed as shown in FIG. First, in step 31, the drive shaft rotation speed is read,
In step 32, an engine brake braking torque when the throttle is fully closed, which is determined according to the rotation speed at that time, is calculated.

As shown in FIG. 12, the braking torque by the engine brake when fuel injection is stopped is generally
There are two types, one based on the friction of the rotating part and the sliding part, and the other based on the pumping loss according to the throttle opening. Among these, the braking torque due to the friction is almost constant and cannot be adjusted, but the braking torque due to the pumping loss Changes according to the throttle opening and can be adjusted.

As shown in FIG. 13, the magnitude of the pumping loss that occurs when the fuel injection is stopped when the throttle is fully closed changes depending on the rotational speed at that time, and the higher the rotational speed, the greater the braking torque. Therefore, the braking torque is calculated by inputting the rotation speed and the throttle opening at that time from a map in which the engine braking torque corresponding to the rotation speed and the throttle opening is set.

Similarly, in step 33, based on the rotational speed at that time, the engine brake braking torque when the throttle is fully opened is obtained from the map. As a matter of course, the braking torque by the engine brake when the throttle is fully opened is smaller than when the throttle is fully closed. Further, the braking torque changes according to the throttle opening.

In step 34, the adjustable width of the engine brake is obtained by subtracting the braking torque when the throttle is fully opened from the calculated braking torque when the throttle is fully closed. In other words, the braking torque can be changed (decreased) by this adjustable width by changing the opening of the throttle valve from fully closed to fully opened during deceleration in the fuel injection stop state.

Next, returning to step 4 in FIG. 2, the maximum value of the regenerative braking torque of the electric motor is calculated. Generally, the regenerative braking torque that can be generated by an electric motor is determined by the current rating of the motor torque control circuit, the maximum output characteristics of the motor, the battery voltage for the motor, and the like, as shown in FIG. Accordingly, as shown in FIG. 6, after the rotational speed of the drive shaft is read in step 41, the regenerative braking torque of the electric motor is referred to in the table set in FIG. From the maximum braking torque that can be regenerated.

After calculating the regenerative braking torque of the electric motor in this way, the process proceeds to step 5 in FIG. 2, and based on this, the regenerative braking torque command value of the electric motor is calculated.

This is specifically performed as shown in FIG.
That is, first, at step 51, the adjustable width of the engine brake braking torque of the internal combustion engine calculated as described above is read, at step 52, the maximum value of the regenerative braking torque of the electric motor is read, and at step 53, the magnitudes of these two are read. That is, the engine brake braking torque adjustable width is compared with the maximum value of the regenerative braking torque. If the maximum value of the regenerative braking torque is larger, the process proceeds to step 54, and the regenerative braking torque command value at that time is obtained. When a torque value equal to the engine brake braking torque adjustable width is set and the regenerative braking torque maximum value is smaller,
Proceeding to step 55, the regenerative braking torque maximum value is set as the regenerative braking torque command value.

After setting the regenerative braking torque command value by the electric motor in this way, the process returns to step 6 in FIG. 2 to adjust the engine brake braking torque of the internal combustion engine. This adjustment is specifically performed as shown in FIG.

That is, in step 61, the engine brake braking torque when the throttle is fully closed is read.
In Step 2, the command value of the regenerative braking torque is read, and Step 63
With the target value of the engine brake braking torque of the internal combustion engine,
It is determined by subtracting the regenerative braking torque command value from the engine brake braking torque when the throttle is fully closed.

In step 64, the throttle opening required for generating the braking torque by the engine brake corresponding to the target value of the braking torque is stored in a map as shown in FIG. The throttle opening is adjusted with reference to the output of the throttle opening as an input), and the opening of the throttle valve is adjusted (opened from the fully closed state) so as to match this.

That is, the sum of the braking torque target value by the engine brake (pumping loss) with the throttle opening open and the regenerative braking torque command value of the electric motor is the braking torque generated by the engine brake when the throttle is fully closed. Becomes equal to

Regarding the control of the throttle opening, as shown in FIG. 9, it is also possible to perform feedback control so as to match the target braking torque while detecting the actual braking torque.

Steps 61 to 64 in FIG. 9 are the same as those in FIG. 8, but if the target throttle opening is calculated, the routine proceeds to step 71, where the detected torque value or calculated value of the drive shaft of the internal combustion engine is calculated. Then, the magnitude of the engine brake braking torque target value is compared with the absolute value of the detected or calculated drive shaft torque value (step 72).

In this case, the driving shaft torque of the internal combustion engine becomes a negative value because the braking is being performed by the engine brake.
If the target value of the braking torque is larger than the actual torque, the routine proceeds to step 73, in which the throttle opening is reduced by a predetermined amount to increase the effectiveness of the engine brake. On the other hand, if the actual torque is larger,
In step 4, the throttle opening is opened by a predetermined amount to weaken the effect of the engine brake.

[0049] In this way, the braking torque by the engine brake can be accurately matched with the target value.

The braking torque by the engine brake can be adjusted not only by the throttle opening but also by controlling the opening of an AAC valve that controls the intake air amount by bypassing the throttle valve.

As shown in FIG. 14, the generated braking torque varies between when the AAC valve is fully opened and when the AAC valve is fully closed, and this deviation is used to adjust the opening degree of the AAC valve. Corresponds to the adjustable width of the braking torque. Therefore, even when the throttle valve is fully closed, by forcibly opening the opening of the AAC valve, the braking torque by the engine brake can be reduced, and the regeneration efficiency by the electric motor can be increased.

The adjustment of the opening of the AAC valve can be performed in combination with the adjustment of the throttle opening, if necessary. When both are operated, the adjustable range of the braking torque by the engine brake is expanded accordingly. .

The following effects are produced by the above control.

The kinetic energy of the running vehicle is recovered by the electric motor 3 in such a condition that the vehicle is decelerated while the engine brake is being applied, that is, while the vehicle is running at a vehicle speed equal to or higher than a predetermined value, the accelerator opening is fully closed and the internal combustion engine is decelerated. This is performed when the fuel supply to the engine 1 is stopped.

In this case, when the fuel supply stop state at the time of deceleration is determined, the adjustable width of the braking torque by the engine brake of the internal combustion engine is determined based on the running conditions at that time, specifically, the rotational speed of the drive shaft. Is calculated. As shown in FIGS. 12 and 13, the adjustable width of the braking torque is an adjustment width for the braking torque due to the pumping loss excluding the braking torque due to the friction of the internal combustion engine. The maximum adjustable width changes depending on the opening degree of the valve 10, and corresponds to a braking torque difference between when the throttle is fully closed and when the throttle is fully opened.

After calculating the adjustable width of the braking torque by the engine brake, the regenerative braking torque by the electric motor 3 is determined within the adjustable width. The regenerative braking torque is determined according to the number of revolutions at that time, motor output characteristics, and the like, but is regulated so that the maximum value does not exceed the adjustable width.

Then, the opening of the throttle valve 10 is calculated so that a braking torque corresponding to a value obtained by subtracting the regenerative braking torque from the braking torque when the throttle is fully closed is generated. Open the valve 10. In this case, when the adjustable range of the braking torque matches the regenerative braking torque, the throttle valve 10 is fully opened.

When the opening of the throttle valve 10 is opened in this manner, the braking torque due to the pumping loss decreases, and the kinetic energy of the vehicle is consumed as regenerative braking torque by the electric motor 3 at least for this reduction. Accordingly, the amount of power generation increases, and the charge amount of the power storage device 6 can be increased.

However, since the regenerative braking torque by the electric motor 3 corresponds to the reduction of the pumping loss due to the opening of the throttle valve 10, the total braking torque is equal to the normal fuel without regenerative braking by the electric motor 3. The braking torque is the same as the braking torque generated by the engine brake when the supply is stopped, and the opening of the throttle valve 10 does not cause the deceleration driving characteristic to change significantly from the normal feeling of deceleration. The driver does not feel uncomfortable when decelerating, such as when the engine brake does not work or works too much.

In particular, when feedback control of the engine brake at this time is performed while detecting the actual braking torque, it is possible to accurately match the target value with the target value and to reliably prevent fluctuations in the sense of deceleration during deceleration driving. be able to.

The fuel supply is stopped at the time of deceleration by detecting the opening of the accelerator pedal.
Even if is opened, the stop of the fuel supply is not canceled halfway.

Next, another embodiment of the present invention shown in FIG. 3 will be described. In this embodiment, the energy regeneration characteristic of the electric motor 3 is adjusted according to the state of charge of the power storage device 6 and the temperature of the catalyst. It is.

In this figure, steps 1 to 4
2 is the same as that of FIG. 2, but after calculating the maximum value of the regenerative braking torque of the electric motor in step 4, the process proceeds to steps 11 to 13, where the state of charge of the power storage device and the temperature of the exhaust catalyst are detected. Calculate the regeneration rate coefficient according to.

This prevents the electric storage device from being overcharged or overdischarged due to regenerative braking of the electric motor, and prevents the electric power from being discharged when the temperature of the catalyst for purifying the exhaust gas of the engine is low and the activation is insufficient. This is to prevent a decrease in the temperature of the catalyst caused by increasing the intake air when the fuel supply is stopped for the motor regenerative braking.

Specifically, this is performed as shown in FIG. That is, in step 81, the terminal voltage of the power storage device is read,
Based on this, the state of charge is determined with reference to a state of charge table as shown in FIG. 15 (step 82).

The maximum voltage at which there is a risk of overcharging when the terminal voltage of the power storage device is higher, and the minimum voltage at which there is a risk of overdischarging below the terminal voltage are determined. As shown in FIG. If the voltage is below the minimum voltage, the charging state is 0%,
If it is higher than the maximum voltage, it is set to 100%.

When a lead battery is used as the power storage device, the state of charge may be detected from the internal resistance of the power storage area, the specific gravity of the electrolyte, and the like.

Next, at step 83, the temperature of the exhaust catalyst is read, and it is determined whether or not the temperature of the exhaust catalyst is equal to or higher than a predetermined value corresponding to a temperature at which the catalyst is sufficiently activated.
If it is equal to or greater than the predetermined value, the process proceeds from step 85 to 86,
Based on the state of charge, the regeneration rate coefficient is calculated with reference to a table as shown in FIG.

The regeneration rate coefficient is, for example, 100% when the state of charge is between 0% and a predetermined value close to 100%, and becomes zero when the state of charge is 100% above the predetermined value. The characteristic is set to decrease to However, the present invention is not limited to this, and any characteristic may be used as long as the regeneration rate coefficient decreases as the state of charge increases.

On the other hand, if the exhaust catalyst temperature is equal to or lower than the predetermined value, the routine proceeds to step 87, where the regeneration rate coefficient is set to 0, and the processing is terminated. This is to prevent a decrease in the catalyst temperature due to an increase in the amount of intake air when the fuel supply is stopped when the catalyst temperature is low. In this state, regenerative braking by the electric motor is prohibited, and the throttle opening is Is kept fully closed.

After calculating the regeneration rate coefficient in this way,
Returning to step 14 in FIG. 3, the regenerative braking torque command value of the electric motor is calculated. This is specifically performed as shown in FIG.

In steps 51 and 52, step 5 in FIG.
Similarly to steps 1 and 52, the adjustable range of the engine brake braking torque of the internal combustion engine and the maximum value of the regenerative braking torque of the electric motor are read, and further, at step 91, the above-mentioned regeneration rate coefficient is read.

In step 92, the regenerative rate coefficient is multiplied by the adjustable range of the engine brake braking torque to obtain
It is determined whether this value is smaller than the maximum value of the regenerative braking torque.

If the result of the multiplication is smaller than the maximum value of the regenerative braking torque, the routine proceeds to step 93, where the result of the multiplication is directly used as the regenerative braking torque command value. The maximum torque value is used as the command value.

FIG. 17 shows the relationship between the regenerative braking torque command value of the electric motor and the target value of the engine brake braking torque of the internal combustion engine in relation to the regeneration rate coefficient.
As the regeneration rate coefficient increases, the ratio of the regenerative braking torque of the electric motor to the total braking torque increases.

After setting the command value of the regenerative braking torque in this way, in step 15 of FIG. 3, the throttle opening is opened in accordance with the command value, and the engine brake braking torque of the internal combustion engine is adjusted.

Therefore, in this example, if the state of charge of the power storage device 6 is higher than that, there is a risk that it will be overcharged, or if the catalyst temperature is low and the fuel supply is stopped during deceleration, the intake air amount will increase. If the catalyst temperature further drops and the active state may be lost, the regenerative rate coefficient becomes 0 or smaller, and accordingly, the regenerative braking torque by the electric motor 3 becomes 0 or smaller. It is possible to reduce the amount of energy regenerated by the motor, that is, the amount of charge, prevent the power storage device 6 from deteriorating, and reduce the amount of intake air to prevent a decrease in exhaust gas temperature.

[0078]

[0079]

Effect of the Invention According to the first invention, regenerative braking torque calculated based on the rotation speed of the fuel supply stop state, and adjusted to fit within the adjustable range of the braking torque by the engine brake, which The regenerative braking by the electric motor is performed on the basis of the above, so that the braking torque does not become larger than in the engine braking state without regenerative braking, and the kinetic energy recovery efficiency at the time of deceleration is maximized without causing a feeling of deceleration. Can be maintained.

According to the second aspect of the invention, the regenerative rate coefficient is calculated based on the state of charge of the power storage device or the temperature state of the exhaust catalyst, and the braking torque that can be regenerated by the electric motor is corrected accordingly. Appropriate deceleration energy can be recovered within a range that does not impair the power storage device or activate the exhaust catalyst.

According to the third aspect of the present invention, the braking torque generated by the engine brake generated when the throttle valve or the control valve in the passage bypassing the throttle valve is fully closed in a state where the fuel supply is stopped, the throttle valve or the control valve Since the adjustable width of the engine brake is calculated based on the deviation from the braking torque when fully opened,
It is possible to adjust the braking torque by the engine brake most accurately.

According to the fourth aspect , the engine brake adjusting means controls the opening of the throttle valve or the control valve of the passage bypassing the throttle valve to adjust the magnitude of the pumping loss. The torque can be accurately controlled, and no special configuration is required for the control.

According to the fifth aspect , feedback control is performed so that the actual output torque of the internal combustion engine in the fuel supply stop state matches the target engine brake braking torque. The combined torque of the motor exactly matches the engine brake braking torque when the throttle or control valve is fully closed without regenerative braking, so that the deceleration energy can be collected most efficiently and no uncomfortable feeling of deceleration occurs.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a flowchart showing the overall control operation.

FIG. 3 is a flowchart showing an overall control operation according to the second embodiment.

FIG. 4 is a flowchart for determining a fuel supply stop state at the time of deceleration.

FIG. 5 is a flowchart for setting an engine brake adjustable width.

FIG. 6 is a flowchart for setting a regenerative braking torque of the electric motor.

FIG. 7 is a flowchart for setting a command value of a regenerative braking torque of the electric motor.

FIG. 8 is a flowchart for obtaining a throttle opening required for generating engine brake braking torque.

FIG. 9 is a flowchart for feedback-controlling a throttle opening required to generate engine brake braking torque.

FIG. 10 is a flowchart for calculating a regeneration rate coefficient of a regenerative braking torque of the electric motor.

FIG. 11 is a flowchart for setting a command value of a regenerative braking torque of the electric motor.

FIG. 12 is an explanatory diagram showing characteristics of a braking torque by an engine brake.

FIG. 13 is an explanatory diagram illustrating a braking torque characteristic by an engine brake that changes according to a throttle opening.

FIG. 14 is an explanatory diagram showing a braking torque characteristic by an engine brake that changes according to an AAC valve opening.

FIG. 15 is an explanatory diagram illustrating a relationship between a state of charge of a power storage device and a terminal voltage.

FIG. 16 is an explanatory diagram showing a relationship between a state of charge and a regeneration rate coefficient.

FIG. 17 is an explanatory diagram showing a relationship between an engine brake braking torque and a regenerative braking torque of an electric motor.

FIG. 18 is an explanatory diagram showing a regenerative braking torque of an electric motor based on a relationship with a drive shaft rotation speed.

FIG. 19 is a configuration diagram of the present invention.

FIG. 20 is a configuration diagram of the present invention.

FIG. 21 is a configuration diagram of the present invention.

[Explanation of symbols]

 51 Deceleration fuel supply stop state determination means 52 Regenerative braking torque adjustment means 53 Engine brake adjustment means

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI H02J 7/00 H02J 7/14 C 7/14 B60K 9/00 E (56) References JP-A-6-55941 (JP, A JP-A-4-88215 (JP, A) JP-A-5-59973 (JP, A) JP-A-8-230499 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 6/02 B60K 25/02 F02D 9/00-11/10 F02D 41/00-41/40 F02D 43/00-43/04 F02D 45/00 B60L 7/00-7/28

Claims (5)

(57) [Claims] An electric motor connected to a drive shaft of an internal combustion engine; and a power storage device connected to the electric motor. The electric power is supplied from the power storage device to the electric motor during acceleration to perform auxiliary driving. Means for determining that the internal combustion engine is in a fuel supply stop state during deceleration in a hybrid vehicle that performs regenerative braking by an electric motor during deceleration and braking and charges generated electric energy to a power storage device ; and rotation of the drive shaft. A means for detecting a speed, and an air-fuel ratio of the internal combustion engine at a rotational speed when the fuel supply is stopped.
Calculate the adjustable width of the braking torque by the engine brake
Means that can generate an electric motor at the same rotational speed.
Means for calculating a raw braking torque, and the calculated adjustment even if the regenerative braking torque that can be generated is maximum.
Adjust the regenerative braking torque of the electric motor so that it falls within the allowable width.
Adjusting means and fuel for the regenerative braking torque of this electric motor
Control of the internal combustion engine by the engine brake when the supply is stopped
A control device for a hybrid vehicle, comprising: engine brake adjusting means for reducing dynamic torque . 2. An electric motor connected to a drive shaft of an internal combustion engine, and a power storage device connected to the electric motor, the electric power being supplied from the power storage device to the electric motor during acceleration to perform auxiliary driving, Means for judging that the internal combustion engine is in a fuel supply stop state during deceleration in a hybrid vehicle that performs regenerative braking by an electric motor during deceleration and braking and charges generated electric energy to a power storage device; and rotation of the drive shaft. Means for detecting the speed; means for calculating the adjustable width of the braking torque by the engine brake of the internal combustion engine at the rotation speed when the fuel supply is stopped; and calculation of the regenerative braking torque that can be generated by the electric motor at the rotation speed. Means for detecting the state of charge of the power storage device or exhaust catalyst
At least one of the means for detecting the temperature of the battery , and at least the state of charge of the power storage device or the temperature of the exhaust catalyst.
To calculate the regeneration rate coefficient of the electric motor based on
And a regenerative braking torque that can be generated based on the regenerative rate coefficient.
Means for correcting the torque, and adjusting the calculated regenerative braking torque even if the
Adjust the regenerative braking torque of the electric motor so that it falls within the
Means for settling the control of a hybrid vehicle, comprising an engine brake adjusting means for reducing the braking torque by the engine brake of the internal combustion engine in an amount corresponding fuel supply stop state corresponding to the regenerative braking torque of the electric motor apparatus. 3. A means for calculating an adjustable width of the braking torque.
Is the throttle valve or throttle at that speed.
When the control valve in the passage bypassing the rottle valve is fully closed
Torque by engine brake and slot
Torque when the valve or control valve is fully opened
The adjustable width of the engine brake is calculated based on the deviation from
The control device for a hybrid vehicle according to claim 1 , wherein the control device outputs the control signal. 4. An engine brake adjusting means, comprising :
Braking torque by the on-brake
Restriction of passage to bypass lube or throttle valve
Adjustable by changing the opening of the valve
The control device for a hybrid vehicle according to any one of claims 1 to 3, wherein 5. A means for detecting an output torque of an internal combustion engine,
Throttle valve or control valve when fuel supply is stopped
Torque generated by the engine brake when the vehicle is fully closed
Target obtained by subtracting the regenerative braking torque from the electric motor from
Engage the braking torque so that it matches the detected torque.
Means for feedback controlling the gin brake adjusting means;
Apparatus as claimed in any one of claims 1 to 4, comprising a.