JP2002027611A - Drive controller for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent impact and delay at start, when the internal combustion engine of a hybrid vehicle is started during driving on power from the motor thereof. SOLUTION: The drive controller for hybrid vehicle, when the hybrid vehicle is driven by transmitting the output of the motor to the power transmission system for driving thereof, is to couple the internal combustion engine with the power transmission system to start the internal combustion engine. The drive controller is provided with a start request judging means for judging requests for starting the internal combustion engine, and an assist amount setting means, that when the start request judging means judges that a request to start the internal combustion engine has been made, increases the output torque of the motor by a motoring torque determined, based on the target number of revolutions of the internal combustion engine or a torque equal to torque obtained by adding an inertial torque which corresponds to the rate of change in the number of revolutions of the internal combustion engine to the motoring torque (Step 074).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a hybrid vehicle using an internal combustion engine such as a gasoline engine or a diesel engine and an electric motor operating by electric power such as a motor or a motor generator to output torque. The present invention relates to a drive control device, and more particularly to a drive control device for a hybrid vehicle that can use both an internal combustion engine and an electric motor as power sources for traveling.

[0002]

2. Description of the Related Art A hybrid vehicle is a vehicle that has been developed in order to improve the deterioration of exhaust gas and the reduction of fuel consumption when the vehicle is driven only by an internal combustion engine, and also serves as a motor or a generator that generates a running torque by electric power. The motor-generator is a vehicle equipped with an internal combustion engine. As this type of vehicle, a so-called series hybrid vehicle that uses an internal combustion engine only as a power source for power generation and a so-called parallel hybrid vehicle that can use the internal combustion engine as a power source for traveling are known.

On the other hand, an internal combustion engine cannot be started only by supplying fuel, but must be started by forcibly rotating it by an external force. Therefore, a motor generally called a starter is attached to the internal combustion engine. However, in the above-described parallel hybrid type vehicle, since the internal combustion engine can be connected to the power transmission system for traveling together with the electric motor,
The internal combustion engine is forcibly rotated by the electric motor, so that the internal combustion engine can be started. Therefore, for example, in a state of low vehicle speed such as at the time of starting, in order to prevent deterioration of exhaust gas and improve fuel efficiency, the vehicle is driven by an electric motor, and when the internal combustion engine is started at a time when the vehicle speed is increased to a certain extent, the running If the output torque of the electric motor used is transmitted to the internal combustion engine, it becomes possible to start the internal combustion engine without using a conventionally used starter. In other words, it is possible to eliminate the starter and reduce the number of parts.

An apparatus for performing such start control of an internal combustion engine is described in Japanese Patent Application Laid-Open No. 9-193676. The device described in this publication connects an internal combustion engine to a predetermined rotating element of a planetary gear mechanism via an input clutch, connects a motor generator to another rotating element, and further outputs a third rotating element. This is a device based on a driving device configured as a member. In this conventional apparatus, the torque is transmitted to the internal combustion engine by engaging the input clutch while the vehicle is running by the output of the motor / generator, and the internal combustion engine is started by forcibly rotating it. ing.

[0005]

According to the above-mentioned conventional apparatus, the internal combustion engine can be started without using a starter. However, when the input clutch is engaged to rotate the internal combustion engine, the running of the internal combustion engine is stopped. A part of the output torque of the electric motor used for the power consumption is consumed as torque (motoring torque and inertia torque) for rotating the internal combustion engine, so that the driving force temporarily decreases. That is, the running torque decreases with the engagement of the input clutch,
This could be felt as a shock.

On the other hand, after the internal combustion engine is started, the vehicle is driven by the electric motor and the internal combustion engine. Therefore, after the rotation speed of the electric motor and the rotation speed of the internal combustion engine match, the input clutch is completely engaged. It is common to do. However, even if the rotation speeds of the electric motor and the internal combustion engine are the same, if the rates of change of the rotation speeds (increase rates of the rotation speeds) are different from each other, the input clutch is completely engaged. Later, one power source with a low speed increase, i.e. an electric motor or an internal combustion engine, will be dragged by the other power source with a high speed increase. As a result, a situation similar to that in which the running resistance increases with the complete engagement of the input clutch occurs, and there is a possibility that a shock due to a drop in the driving force may occur.

In addition, when the input clutch is engaged to increase the rotation speed of the internal combustion engine while the vehicle is running by the electric motor, combustion is generated in the internal combustion engine when the internal combustion engine is started by supplying fuel. Output torque is
It is added to the torque for running. Therefore, if the input clutch has sufficient transmission torque capacity at that time,
Since the output torque of the internal combustion engine is added to the running torque of the electric motor, the driving force sharply increases, which may be felt as a shock.

Incidentally, as the input clutch, a multi-plate type friction clutch which is engaged by hydraulic pressure can be used, and the aforementioned publication also discloses a multi-plate clutch as an input clutch. When this type of clutch is engaged, a valve provided in the hydraulic circuit is switched, and hydraulic pressure is supplied to the clutch from a hydraulic pressure source. In that case,
Since line resistance is inevitably generated, there is a time delay from when the input clutch is instructed to when the input clutch is actually engaged.

Further, in the input clutch, a gap is formed between the friction plates or between the friction plate and a piston pressing the friction plate. When the hydraulic pressure starts to be supplied to the input clutch, first, the gap ( Pack clearance) is clogged, and then the torque is transmitted between the friction plates. Since the internal combustion engine cannot be rotated while the pack clearance is blocked, a time delay occurs in control for rotating the internal combustion engine. As described above, due to a delay factor in the mechanical structure, the response of the start control of the internal combustion engine may be deteriorated.

Further, even if the rotation speed of the internal combustion engine becomes a rotation speed at which combustion is continuously generated by the supply of fuel, the internal combustion engine does not immediately generate torque and start continuous operation upon the start of fuel supply. In some cases, a delay may occur before the generation of torque due to the temperature of the internal combustion engine, the outside air temperature, or the like. Such a delay, in combination with the above-described delay of the operation of the input clutch, may deteriorate the responsiveness of the start control of the internal combustion engine, or may cause a so-called sluggish feeling due to a delay in increasing the driving force. .

The present invention has been made in view of the above circumstances, and provides a drive control device capable of preventing a shock when starting an internal combustion engine while traveling with an electric motor and improving responsiveness. It is intended to do so.

[0012]

Means for Solving the Problems and Action Therefor To solve the above-mentioned problems, the invention described in claim 1 is provided when the vehicle is traveling by transmitting the output of the electric motor to a power transmission system for traveling. In a drive control device for a hybrid vehicle that starts the internal combustion engine by connecting the internal combustion engine to the power transmission system, a start request determination unit that determines a request for starting the internal combustion engine, and a request for starting the internal combustion engine. If it is determined by the start request determining means that the motor is running, the output torque of the electric motor is changed to a motoring torque determined based on a target rotational speed of the internal combustion engine or the motoring torque is set to the rotational speed of the internal combustion engine. And an assist amount setting means for increasing the torque by an amount corresponding to a torque obtained by adding an inertia torque corresponding to the rate of change of the assist amount.

According to the first aspect of the present invention, when the internal combustion engine is rotated by the output torque of the electric motor to start the internal combustion engine, the shortage of the output torque of the electric motor or the torque for rotating the internal combustion engine is determined. , And the output torque of the electric motor is increased based on the detection result, thereby preventing a temporary shortage of driving force during traveling and a shock resulting from the shortage.

According to a second aspect of the present invention, when the vehicle is traveling by transmitting the output of the electric motor to a power transmission system for traveling,
In a drive control device for a hybrid vehicle that connects an internal combustion engine to the power transmission system and starts the internal combustion engine, after starting the internal combustion engine by connecting the internal combustion engine to the power transmission system, Synchronization detection means for detecting that the rotation speed is equal to or greater than a rotation speed of the electric motor or a reference value determined based on the rotation speed of the electric motor, and a rotation speed of the internal combustion engine based on the rotation speed of the electric motor or the rotation speed of the electric motor. Means for decreasing the output torque of the motor increased to start the internal combustion engine when the synchronization detection means detects that the predetermined value has become equal to or greater than the determined reference value; Means for reducing the output torque of the electric motor even when the output torque is not increased. Than it is.

Therefore, according to the second aspect of the present invention, when the internal combustion engine is rotated by the electric motor to start the internal combustion engine, whether the output of the electric motor is excessive or insufficient is constantly monitored as the number of revolutions, and the output of the electric motor is monitored. If the number of rotations decreases due to lack of power, the output of the motor increases,
A temporary decrease in driving force and a shock resulting therefrom are prevented.

[0016]

Next, the present invention will be described more specifically. The drive control device of the present invention is a device for controlling the drive force of a hybrid vehicle including two types of power sources, that is, an internal combustion engine and an electric motor that operates and outputs power. Here, the internal combustion engine is, in short, a power source that outputs power by burning fuel, specifically, a gasoline engine, a diesel engine, or a gas engine using a gaseous fuel such as hydrogen gas. Further, the type is not limited to the reciprocating engine, but may be a turbine engine or the like. In the following description, the internal combustion engine is referred to as "engine".

The motor may be any power source having a function of operating and outputting electric power, and various motors such as an AC permanent magnet synchronous motor and a DC motor can be used. Can use a motor / generator that also has a function of generating power by being driven by an external force. Further, an electric motor and a generator can be used together. The example described below is an example using a motor generator as the electric motor.

The hybrid vehicle to which the present invention is applied is:
This is a hybrid vehicle in which an internal combustion engine is rotated by an output of an electric motor, and fuel is supplied when the rotation speed of the internal combustion engine reaches a predetermined rotation speed to start the internal combustion engine. That is, it is a so-called parallel-type hybrid vehicle in which the internal combustion engine and the electric motor are connected together to a power transmission system for traveling, and can travel by their respective outputs.

The power transmission system is essentially a mechanism for transmitting the driving force to the wheels for traveling, and may or may not have a transmission. If a transmission is provided, it is possible to control the driving force in the power transmission system. As the transmission, a manual transmission that changes the transmission ratio by a manual operation or an automatic transmission whose transmission ratio is controlled according to a running state such as a vehicle speed and an engine load can be used. Not only a stepped transmission that changes its gear ratio step by step,
A continuously variable transmission in which the gear ratio continuously changes can also be used. The following example shows an example using an automatic transmission.

FIG. 1 is a block diagram schematically showing a drive control device according to the present invention, in which an output shaft (ie, a crankshaft) 2 of an engine 1 includes a motor generator 3.
, Via an input clutch 5. The input clutch 5 corresponds to a clutch means in the present invention, and is a connecting mechanism for selectively connecting the output shafts 2 and 4. More specifically, a friction clutch of a type in which friction plates are brought into contact with each other by hydraulic pressure to have a transmission torque capacity and the transmission torque capacity increases in accordance with the supplied hydraulic pressure is used as the input clutch 5. And a wet multi-plate clutch can be used. A control device (not shown) for electrically controlling the hydraulic pressure to the input clutch 5 and the supply and discharge thereof
Is provided.

The engine 1 in the example shown in FIG. 1 is an engine of a type that electrically controls ignition timing, fuel supply amount (fuel injection amount), idle speed, valve timing, and the like. Control device (engine EC
U) 6 are provided. The electronic control device 6 is a device mainly composed of a microcomputer, and receives data such as an intake air amount, an accelerator position, an engine water temperature, and an engine speed NE, and inputs data and programs stored in advance. The control amount such as the ignition timing is determined and output based on the data.

The engine 1 has an electronic throttle valve 7 for electrically controlling the throttle opening. The opening of the electronic throttle valve 7 is controlled by a control amount calculated based on various amounts of data such as a depression amount of an accelerator pedal (not shown) and a mode signal selected by a mode selection switch. . An electronic control unit (electronic throttle ECU) 8 for performing the control is provided. This electronic control unit 8 is also constituted mainly by a microcomputer.

The motor / generator 3 has a known structure in which, for example, a rotor integrated with the output shaft 4 is rotatably arranged on the inner peripheral side of a stator having a coil, and further includes a resolver for detecting rotation of the rotor. By controlling the energization of the coil, the rotor rotates forward or backward, the torque thereof is controlled, and the rotor is rotated by an external force to generate an electromotive force. . In order to control the motor generator 3, an electronic control unit (M / G-ECU) 9 mainly composed of a microcomputer is provided. The electronic control unit 9 receives, for example, the rotation speed (motor rotation speed) NM of the motor generator 3 as control data.

Further, a battery 10 for supplying a current to the motor generator 3 and storing the electric power generated by the motor generator 3 is provided. This battery 10
Electronic control unit (battery ECU) 11 mainly composed of a microcomputer for controlling discharge and charge of the battery
Is provided.

The output shaft 4 of the motor / generator 3
The input shaft 14 of the transmission 13 is connected to the transmission 13. This figure 1
In the example shown in FIG. 1, an electronically controlled automatic transmission in which the gear ratio is controlled based on the running state is employed as the transmission 13. That is, the transmission 13 determines a gear ratio based on data such as a throttle opening, a vehicle speed, a shift pattern, and a shift range, and a frictional engagement device (not shown) such as a clutch or a brake so as to achieve the gear ratio. ) Is controlled by hydraulic pressure. For the control, an electronic control unit (T / M-ECU) 15 mainly including a microcomputer is provided.

The output shaft 16 of the transmission 13 is connected to wheels via a propeller shaft or axle (not shown). Therefore, the transmission 13, the propeller shaft connected to the transmission 13, the output shaft 4 of the motor generator 3, and the like correspond to a power transmission system in the present invention.

Each of the above electronic control units 6, 8, 9, 11,
Reference numeral 15 is connected to a hybrid control device (HV-ECU) 17 mainly composed of a microcomputer so as to mutually communicate data. The hybrid control device 17 controls engagement / disengagement of the input clutch 5 and transmission torque capacity, control of fuel supply timing and fuel supply amount of the engine 1, and drive / regeneration and output torque of the motor / generator 3. Control, transmission 13
, And controls the driving force of the hybrid vehicle. That is, the hybrid control device 17 inputs and outputs data required for the control and has a program for data processing.

A hybrid vehicle is a vehicle developed mainly for the purpose of improving fuel efficiency and purifying exhaust gas. The hybrid vehicle runs with the output of a motor at a low vehicle speed, and runs at a constant vehicle speed above a predetermined vehicle speed. The power source is selected according to the traveling state, such as traveling with the output of the engine when traveling, and traveling with the output of the engine and the motor when greater driving force is required. Therefore, the engine is started when the vehicle is running by the motor. When the power transmission system is configured as shown in FIG. 1, the motor torque is transmitted to the engine to rotate the engine. Thus, the engine can be started.

Therefore, the drive control device according to the present invention controls the start of the engine 1 as described below. FIG.
Is a flowchart showing a control for connecting the engine 1 to the power transmission system for starting control of the engine 1, that is, an overall control routine for controlling the engagement of the input clutch 5, and this routine is performed for several milliseconds. It is repeatedly executed every time.

First, at step 001, it is determined whether or not the engine start request flag F1 is ON. The request for starting the engine 1 is determined by a subroutine (not shown). Specifically, when the vehicle speed reaches a predetermined vehicle speed while traveling with the output of the motor generator 3 or when the charge amount of the battery 10 decreases, the vehicle is traveling with the motor generator 3. At this time, the engine start request flag F1 is turned ON when the accelerator pedal (not shown) is greatly depressed and a drive force increase request is made.

If an affirmative determination is made in step 001 because the engine start request flag F1 is on, the engine start control flag F2 is turned on (step 00).
2). Conversely, the engine start request flag F1 is turned off.
Therefore, if a negative determination is made in step 001, it is determined whether the engine start control flag F2 is ON (step 003). If both the engine start request flag F1 and the engine start control flag F2 are OFF because there is no engine start request yet, a negative determination is made in step 003, and in this case, this routine ends. Also, the engine start control flag F2 has already been set.
Is turned on, and the determination in step 001 is made again, a negative determination is made because the engine start request flag F1 has been turned off. However, since the engine start control flag F2 has already been turned on, 00
A positive determination is made at 3.

After the engine start control flag F2 is turned on in step 002, or if an affirmative determination is made in step 003, the hydraulic pressure processing of the input clutch 5 (step 004) and the motor torque processing (step 00)
5) Perform engine torque processing (step 006) and downshift start permission processing (step 007). In addition, each process of these steps 004 to 007 will be described later.

Next, it is determined whether the engagement end determination flag F3 of the input clutch 5 is ON (step 008).
Since the input clutch 5 is a clutch for connecting the engine 1 to a power transmission system, the engine 1 is kept rotating by supplying fuel, or the torque of the motor generator 3 is reduced accordingly. It is possible to determine that the input clutch 5 has been completely engaged, for example, by starting the engagement. And this step 0
If a negative determination is made in 08, that is, if the engagement of the input clutch 5 has not been completed, the process exits from this routine and continues the processing of steps 004 to 007. On the other hand, if the determination of step 008 is affirmative because the engagement of the input clutch 5 has been completed,
Control for switching the engine start control flag F2 to OFF and output of an ON signal for the engagement end determination flag F3 are performed (step 009), and the engagement process of the input clutch 5 is ended.

When a request to start the engine 1 is made, the engine 1 is rotated by the motor torque by engaging the input clutch 5 and connecting the engine 1 to a power transmission system. The hydraulic pressure of the input clutch 5 is controlled as described below in order to prevent the shock caused by the above. 3 to 5 show a subroutine for hydraulic processing of the input clutch which is interrupted in step 004.

This subroutine is repeatedly executed at intervals of several milliseconds in accordance with the execution of the routine shown in FIG.
Therefore, in step 011, it is determined whether this subroutine is executed for the first time. If the hydraulic pressure processing for engaging the input clutch 5 is started, the determination is affirmative in step 011, and conversely, if the hydraulic pressure processing for engaging the input clutch 5 is already started, FIG. Since the execution of the routine shown in FIG. 5 is performed for the second time or later, a negative determination is made in step 011.

If an affirmative determination is made in step 011, the fast quick fill flag (FQF flag) F 4 is turned on (step 012), and the process proceeds to step 013. If the hydraulic pressure processing of the input clutch 5 has already been started and a negative determination is made in step 011, the process immediately proceeds to step 013.

Here, the FQF flag F4 is a flag which is set ON until the supply of the initial hydraulic pressure (FQF hydraulic pressure) for engaging the input clutch 5 is started and the supply control is completed. In addition, this initial hydraulic pressure supply control
In order to quickly fill the gap between the friction plates (not shown) and the gap between the piston (not shown) and the friction plates in the input clutch 5, a preset high oil pressure is supplied as the initial oil pressure. Control. In step 013, it is determined whether or not the FQF flag F4 is ON to determine the start or end of the supply control of the initial hydraulic pressure.

If the start of engagement of the input clutch 5 is determined and the FQF flag F4 is ON, step 0
In step 13, an affirmative determination is made, and in that case, a command to output a fast quick fill hydraulic pressure (FQF hydraulic pressure) as an initial hydraulic pressure is issued (step 014). Input clutch 5
As a means for controlling the hydraulic pressure, an electrically controllable valve such as a duty solenoid valve (linear solenoid valve) can be used. When such a solenoid valve is used, the control in step 014 is performed. Is a control for temporarily increasing the command signal. The command signal is a signal having a predetermined value. Note that this command signal does not need to be a fixed value, and may be a value (ie, a variable) set as a map value according to conditions such as oil temperature.

Next, the power-on downshift flag F5
Is ON (step 015). That is, when the accelerator pedal is depressed and it is determined that a downshift should be performed, the flag F5 is turned ON. The control of the flag F5 is performed by the electronic control unit 15 for the automatic transmission. Then, since this flag F5 is OFF, step 0 is executed.
If a negative determination is made in step 15, it is determined whether or not the supply time (command time) T1 of the initial hydraulic pressure in the normal state has elapsed (step 016).

Conversely, if the determination is affirmative in step 015 because the downshift has been determined, the supply time (command time) of the initial hydraulic pressure for the downshift
It is determined whether T1 'has elapsed (step 01).
7). These command times T1 and T1 'are times during which the command signal for supplying the initial oil pressure is continuously output, and the command time T1 for the normal time is changed to the command time T for the downshift.
It is set to be shorter than 1 '(T1 <T1'). That is, when the downshift is determined, the supply time of the initial hydraulic pressure becomes longer.

If an affirmative determination is made in step 016 or step 017, that is, if the time for supplying the initial pressure has elapsed, the FQF flag F4 is turned off (step 018), and the low-pressure standby hydraulic pressure flag F6 is turned off.
N is set (step 019). On the contrary, since the command times T1 and T1 'do not elapse, step 01 is performed.
6 or if a negative determination is made in step 017,
The process proceeds to step 020, skipping steps 108 and 019. That is, the supply control of the initial oil pressure (FQF oil pressure) is continued.

The process also proceeds to step 020 if a negative determination is made in step 013 because the FQF flag F4 is OFF. That is, in this case, since the supply of the initial oil pressure has been completed, steps 014 to 019 are not executed.

In step 020, it is determined whether the low-pressure standby hydraulic pressure flag F6 is ON. After the supply of the initial hydraulic pressure is completed, the flag is set to ON while the input clutch 5 is kept in the incompletely engaged state. Accordingly, the hydraulic pressure supplied to the input clutch 5 is controlled to disable the input clutch 5. An affirmative determination is made in step 020 while maintaining the complete engagement state, and a negative determination is made in step 020 after the low-pressure standby control ends.

If an affirmative determination is made in step 020 because the low-pressure standby hydraulic pressure flag F6 is ON, it is determined whether or not the power-on downshift flag F5 is ON (step 021). The determination in step 021 is performed in the same manner as the determination in step 015 described above. If a negative determination is made in step 211, a command signal for setting the standby hydraulic pressure for normal use is output (step 022). Conversely, step 02
If an affirmative determination is made in step 1, a command signal for setting the standby hydraulic pressure for downshifting is output (step 02).
3).

Here, the standby hydraulic pressure is a hydraulic pressure required to wait the input clutch 5 in an incompletely engaged state after supplying the initial hydraulic pressure to the input clutch 5. In addition, the incompletely engaged state is, for example, an engagement state in which the transmission torque capacity is slightly smaller than the applied torque so that a rotation change on the output side does not occur, or a slight increase in the hydraulic pressure causes the load torque to decrease. This is an engagement state in which the transmission torque capacity is greater and a rotation change occurs on the output side. Then, the standby hydraulic pressure for downshift is set higher than the standby hydraulic pressure for normal operation.

Therefore, when a downshift is determined, the input clutch 5 is brought into a state closer to the fully engaged state. The low-pressure standby hydraulic pressure command is specifically issued by outputting a pulse signal to a duty solenoid valve (linear solenoid valve) as hydraulic control means. The command signal may be changed depending on the oil temperature, in addition to being different between the normal time and the downshift.

After the control of the standby oil pressure is started as described above, the engine speed NE is reduced to a predetermined reference speed N1.
Is determined (step 024). The reference rotation speed N1 is a small value close to zero, and therefore, in this step 024, it is determined whether or not the engine 1 has started to rotate. If an affirmative determination is made in step 024 because the engine 1 starts rotating,
Learning control of the supply time (FQF time) of the initial hydraulic pressure is executed (step 025). This learning control will be described later. Further, following the learning control, the low-pressure standby hydraulic flag F6 is controlled to be turned off (step 027), and the hydraulic sweep-up flag F7 is controlled to be turned on (step 028).

On the other hand, if a negative determination is made in step 024 because the engine 1 does not start rotating, it is determined whether or not the count value of the standby hydraulic timer has become equal to or greater than a predetermined reference value (step 026). ). This is a control by a so-called guard timer, and is a control for preventing standby hydraulic pressure control from continuing for an unnecessarily long time. Therefore, if an affirmative determination is made in step 026, the process immediately proceeds to step 027 to end the standby pressure control. Conversely, if a negative determination is made in step 026, it means that the standby pressure control should be continued, so that steps 027 and 028 are skipped and step 0
Go to 29. It should be noted that even if a negative determination is made in step 020 because the low-pressure standby oil pressure flag F6 is OFF, the process immediately proceeds to step 029. This is because the low-pressure standby control has been completed.

Here, the learning control of the FQF time will be described. As described above, the initial hydraulic pressure is supplied in order to close the gap (pack clearance) in the input clutch 5 and bring the state immediately before the start of engagement. However, if the supply time of the initial hydraulic pressure is short, the pack clearance is sufficiently blocked. Without
On the other hand, if the supply time of the initial hydraulic pressure is long, the input clutch 5 is engaged early and the rotation start of the engine 1 is excessively early. Therefore, the supply time (FQF time) of the initial hydraulic pressure is increased or decreased based on the time from when the supply of the initial hydraulic pressure ends to when the engine 1 starts to rotate, and is set to an appropriate value.

More specifically, the control is performed as shown in FIG.
That is, FIG. 6 shows a subroutine for learning the FQF time.
Is turned off, the time from when the engine speed NE of the engine 1 becomes equal to or higher than the reference engine speed N1 to when an affirmative determination is made in step 024, that is, whether the engine start time T2 exceeds the preset reference time τ1 is determined. Is performed (step 051). If the engine start time T2 is shorter than the reference time τ1 and a negative determination is made in step 051, the process proceeds to step 052 and the engine start time T2
Is less than the second reference time τ2. Here, the second reference time τ2 is a value (τ1> τ2) shorter than the first reference time τ1.

When the engine start time T2 is equal to the second reference time τ
If it is less than 2, the timing at which the engine 1 starts to rotate is too early. This is because the supply time (FQF time) T1 of the initial hydraulic pressure (FQF hydraulic pressure) is long, and the initial hydraulic pressure is excessively supplied to the input clutch 5 and the engagement is progressing. Therefore, if an affirmative determination is made in step 052, the predetermined value ΔT1 is subtracted from the FQF time T1 to obtain the FQF time T determined in step 016.
1 is shortened (step 053). That is, the supply time of the next initial hydraulic pressure is shortened, and the input clutch 5 is brought closer to the disengaged state.

On the other hand, when the engine start time T2 is the first
If the answer is affirmative in step 051, the torque is not sufficiently transmitted to the engine 1 via the input clutch 5.
Therefore, in this case, a predetermined value ΔT1 is added to the FQF time T1.
To increase the FQF time T1 determined in step 016 (step 054). That is, the supply time of the next initial hydraulic pressure is lengthened to bring the input clutch 5 closer to the engaged state. If the engine start time T2 is between the reference times τ1 and τ2 and is appropriate, the FQF time T1 is not increased or decreased, and the detected engine start time T2 is stored as it is (step 055). To return. If the control in step 053 or step 054 has been performed, the flow advances to step 055 to store the engine start time T2.

Next, the sweep-up control of the hydraulic pressure of the input clutch 5 will be described. This control is a control for smoothly increasing the engine speed NE by gradually increasing the oil pressure of the input clutch 5, and the engine 1 starts rotating after the standby oil pressure control is started as described above. Is detected, the sweep-up control is started. Specifically, as shown in FIG. 4, it is determined whether or not the hydraulic sweep-up flag F7 is ON (step 029). If the hydraulic sweep-up control has started, an affirmative determination is made in step 029, and if the hydraulic sweep-up control has not started or has already ended, a negative determination is made in step 029.

Since the sweep-up control for gradually increasing the hydraulic pressure of the input clutch 5 has been started, step 029
If the determination in step 3 is affirmative, it is determined whether the power-on downshift flag F5 is ON (step 03).
0). Step 030 is a determination step similar to steps 015 and 021 described above. If an affirmative determination is made in step 030 because a downshift has been determined, it is determined whether the engine speed NE is lower than a predetermined reference value N2 (step 031).

The reference value N2 is, for example, a value on the order of the idling speed. Therefore, if an affirmative determination is made in step 031, the engine speed NE is increased even though the drive force is required to be increased by the downshift.
Is low, the sweep-up gradient of the hydraulic pressure of the input clutch 5 is increased to raise the engine speed NE to the target speed in a short time (step 032). The control for increasing the sweep-up gradient may be continued until the engine speed NE is synchronized with the motor speed NM.

On the other hand, if a negative determination is made in step 030 because the power-on downshift has not been determined, or the power-on downshift has been determined, but the engine speed NE is equal to or higher than the reference speed N2. Accordingly, when a negative determination is made in step 032, the sweep-up gradient of the hydraulic pressure of the input clutch 5 is
The normal gradient is set smaller than the gradient set in step 032 (step 033). It should be noted that the normal sweep-up gradient set in step 033 is predetermined so that a feeling of delay in engine start control does not occur and a decrease in driving force due to a rapid increase in the engine speed does not occur. The gradient. Therefore, the slope of the sweep-up is increased by the determination of the downshift until the engine speed NE reaches the reference value N2.

After the sweep-up gradient is set in step 032 or step 033, the hydraulic command value of the input clutch 5 is swept up according to the set gradient (step 034). Specifically, the duty ratio for controlling the oil pressure of the input clutch 5 is gradually increased or decreased. When the hydraulic pressure of the input clutch 5 is swept up, the torque transmitted from the motor generator 3 to the engine 1 gradually increases.
E gradually approaches the rotation speed of the motor generator 3.

Therefore, in step 035 following step 034, it is determined whether or not the state in which the absolute value of the difference between the engine speed NE and the speed NM of the motor generator 3 is smaller than the reference value N3 has continued for a predetermined time. Is determined (step 035). This reference value N3 is a relatively small value. Therefore, in step 035, it is determined whether or not the engine speed NE is substantially synchronized with the rotation speed (motor rotation speed) NM of the motor generator 3. .

If an affirmative determination is made in step 035 because the engine speed NE is synchronized with the motor speed NM, the hydraulic sweep-up flag F7 is turned off (step 036), and the hydraulic pressure maximum flag F8 is turned on.
(Step 037). That is, the sweep-up control of the hydraulic pressure of the input clutch 5 is terminated, and control for setting the hydraulic pressure to the maximum value is started.

On the other hand, when the engine speed NE is lower than the motor speed NM by the reference value N3 or more, or when the state does not continue even if the engine speed NE substantially matches the motor speed NM, A negative determination is made in step 035. In this case, step 036 and step 03
Skip to step 7 and proceed to step 038. That is, the hydraulic pressure sweep-up control is continued. Also, since the hydraulic sweep-up flag F7 is OFF, the process proceeds to step 029.
If a negative determination is made in step 038, then the hydraulic pressure sweep-up control itself is not executed, so that step 038 is immediately executed.
Proceed to.

At step 038, it is determined whether or not the oil pressure maximum flag F8 is ON. When the sweep-up control of the hydraulic pressure of the input clutch 5 is completed, the flag F8 is controlled to be ON. In other cases, that is, when the hydraulic sweep-up control is continued or the control for maximizing the hydraulic pressure is completed. If so, this flag F8 is set to OFF. Therefore, if the hydraulic pressure sweep-up control is completed and the hydraulic pressure maximum flag F8 is set to ON, an affirmative determination is made in step 038, in which case the input clutch 5
The control for maximizing the hydraulic pressure is executed (step 03).
9). That is, the control command value of the hydraulic pressure of the input clutch 5 is set to the maximum. Specifically, the hydraulic pressure of the input clutch 5 is increased to the line pressure by setting the duty ratio of the command signal to the maximum or the minimum. Note that the oil pressure maximum flag F8 is set to OFF.
If the result is F, and a negative determination is made in step 038, the process skips step 039 and proceeds to step 040, where the control immediately before that is continued.

Next, at step 040, it is determined whether or not the engagement end determination flag F3 of the input clutch 5 is ON.
If the flag F3 is not ON, the control for maximizing the hydraulic command value is continued. On the other hand, if the determination flag F3 of the end of the engagement of the input clutch 5 is ON, then the step 04
If the result is 0, the hydraulic pressure maximum flag F8 is set to O.
After switching to FF, return.

FIG. 7 shows a time chart when the above control is executed. Engine start request flag F
When 1 is turned on at time t1, the engine start control flag F2 and the FQF flag F4 are turned on at the same time. Then, a command value for controlling the hydraulic pressure of the input clutch 5 to the initial hydraulic pressure (FQF hydraulic pressure) is output, and the control is continued for a predetermined FQF time T1. By performing this initial oil pressure control, the oil pressure of the input clutch 5 increases as shown by a thin solid line in FIG. 7 and reaches a pressure equivalent to the standby oil pressure.

At time t2 when the FQF time T1 has elapsed, the FQ
The F flag F4 is turned off, and the low pressure standby pressure flag F
6 is controlled to be ON. At this point, the control value of the hydraulic pressure of the input clutch 5 is set to a value corresponding to the standby hydraulic pressure, and the command value is maintained. In this state, the input clutch 5 transmits the torque but is in an incompletely engaged state, so that the rotational speed NE of the engine 1 does not increase immediately. During the control for maintaining the low standby hydraulic pressure, the output torque of the motor generator 3 is increased as described later, and as a result, the engine 1 starts rotating. This is determined based on the fact that the engine speed NE is equal to or greater than the reference value N1, which is close to zero, as described above.

Then, at time t3 when the determination is made, the low-pressure standby hydraulic flag F6 is turned off, and the hydraulic sweep-up flag F7 is turned on. And input clutch 5
Is started. That is, the hydraulic pressure command value is swept up. As the engagement hydraulic pressure of the input clutch 5 gradually increases, the torque for rotating the engine 1 increases, so that the engine speed NE gradually increases. As a result, if the state in which the difference between the engine speed NE and the motor speed NM falls within the predetermined reference value N3 continues for a predetermined time, the engine speed NE becomes the motor speed NE.
At time t4, the hydraulic sweep-up flag F7 is turned off and the hydraulic maximum flag F8 is turned on. Accordingly, the hydraulic pressure of the input clutch 5 is increased to the line pressure (the original pressure of the entire hydraulic device).

Thereafter, control for switching the power source for traveling from the motor generator 3 to the engine 1 is performed, and at the same time the control is completed, the engagement end flag F3 of the input clutch 5 is turned on. At time t5, the engine start control flag F2 and the oil pressure maximum flag F8 are turned off.

On the other hand, FIG. 8 shows a time chart when the power-on downshift is determined.
In FIG. 8, if, for example, the accelerator pedal is greatly depressed and the power-on downshift flag F5 is turned on at the time t6 when a predetermined time has elapsed from the time t1 when the engine start control flag F2 was turned on by the engine start request, Initial hydraulic pressure supply control time is F for normal time
FQF time T1 for downshifting instead of QF time T1
'Is selected. Further, the standby hydraulic pressure is set to a pressure higher than the normal pressure. 8, a thick solid line indicates a command value at the time of a downshift, and a thin solid line indicates a command value at a normal time. Further, since the downshift is required, the sweep-up gradient of the hydraulic pressure of the input clutch 5 is increased more than usual. In the example shown in FIG. 8, the sweep-up gradient is increased until time t7 when the engine speed NE has increased to some extent.

Therefore, when a downshift is requested, the input clutch 5 is controlled so as to be closer to the engaged state than usual by increasing the initial hydraulic pressure supply time (FQF time) T1 '. You. Further, since the low-pressure standby hydraulic pressure is higher than normal, the transmission torque capacity of the input clutch 5 increases. As a result, since the torque transmitted to the engine 1 is large, the engine 1 starts rotating earlier than usual. After that, since the sweep-up gradient of the hydraulic pressure of the input clutch 5 is set to be larger than usual,
The torque transmitted to the engine 1 is increased earlier than usual. That is, the rotation speed of the engine 1 is quickly raised, and the synchronization of the engine rotation speed NE with the motor rotation speed NM and the start of the engine 1 are achieved early. As a result, traveling by the engine 1 is enabled at an early stage, and control in accordance with a request for increasing the driving force is achieved.

Next, the processing of the motor torque executed in step 005 will be described. This control is a control for preventing a shock due to a change in driving force and a delay in starting the engine 1. The torque control of the motor generator 3 for rotating the engine 1 and the control of the engine 1
After the start of the motor is completed. That is, FIG. 9 is a flowchart showing a motor torque processing subroutine.
It is determined whether the oil pressure maximum flag F8 is ON (step 061). As described above, this oil pressure maximum flag F8
Is a flag that is turned on when it is determined that the engine speed NE is synchronized with the motor speed NM. Therefore, if this flag F8 is on, the substantial start of the engine 1 is completed and the engine 1 rotates with its own output, and outputs torque. Conversely, if the oil pressure maximum flag F8 is OFF, it means that the engine speed NE is not synchronized with the motor speed NM.

If an affirmative determination is made in step 061 because the hydraulic pressure maximum flag F8 is ON, a predetermined time T set after the hydraulic pressure maximum flag F8 is turned ON.
It is determined whether or not 3 has elapsed (step 062).
This time T3 is the time when the engine speed NE is equal to the motor speed N
M, the fuel is supplied to engine 1 and engine 1
Is the time required for the rotation of the engine 1 to stabilize after the rotation of the engine 1 has started. Therefore, step 062 is a judgment process for judging that the engine speed NE is stable. Instead of judging the passage of time, the engine speed N
The stable state of the engine speed NE may be determined based on the detected value of E.

If an affirmative judgment is made in step 062, it means that the rotation of the engine 1 has become stable. Therefore, in this case, the motor torque command value is swept down to gradually reduce the output torque of the motor generator 3. . This is a control for switching from traveling by the motor / generator 3 to traveling by the engine 1 as described later.

On the other hand, when a negative determination is made in step 061 because the hydraulic pressure maximum flag F8 is OFF,
The assist torque calculation process (step 064), the motor torque command calculation process (step 065), and the motor rotation speed increase guard process (step 066) are performed by the motor generator 3. When starting the engine 1 while running with the power of the motor / generator 3, a torque for rotating the engine 1 is applied to the motor / generator 3. The torque required to start the engine 1 by rotating it is the assist torque.
At 64, the assist torque is calculated.

FIG. 10 is a flowchart showing a subroutine of the assist torque calculation. First, a motoring torque is obtained (step 071). The motoring torque is a torque required to rotate the engine 1, and is determined according to the structure and size of the engine 1, the number of rotations to be rotated, and the like. Therefore, in the example shown in FIG. 10, the motoring torque is determined in the form of a map using the engine speed NE as a parameter, and the map is searched based on the target engine speed NE to find the motoring torque.

Next, the rate of increase of the engine speed NE is calculated (step 072). This is calculated based on a change in the engine speed NE that occurs when the motoring torque obtained in step 071 is added to the output torque of the motor generator 3. Specifically, the engine speed NE is detected at regular intervals, and the rate of increase of the engine speed is calculated based on the difference or ratio between the previous detected value and the present detected value. An inertia torque is calculated by multiplying the engine speed increase rate thus obtained by a proportional constant (step 07).
3). In order to raise the engine speed NE to the target speed, a motoring torque and an inertia torque that causes a change in rotation are required. Therefore, the motoring torque and the inertia torque obtained as described above are calculated. In addition, an assist torque is set (step 074).

The assist torque is applied to the motor / generator 3
When the output torque is added to the output torque, an assist torque processing is performed to prevent a sudden change in the torque (step 075). The subroutine of the assist torque processing is shown as a flowchart in FIG. This assist torque processing is a transient control when increasing the output torque of the motor generator 3, and is therefore executed when the assist torque is equal to or greater than zero. That is, it is determined whether or not the assist torque is greater than zero in step 081, and if the assist torque is less than or equal to zero and a negative determination is made in step 081,
To return. On the other hand, when an affirmative determination is made in step 081 because the assist torque is larger than zero, it is determined whether or not the first routine is to be executed as the assist torque processing process started this time (step 082). .

If an affirmative determination is made in step 082, the assist counter is cleared and counting is newly started (step 083). Conversely, if a negative determination is made in step 081, the count by the assist counter has already been started. Therefore, in this case, the process proceeds to step 084, where the assist counter counts up.

Next, it is determined whether or not the count value of the assist count is smaller than a predetermined value (step 085). Here, the predetermined value is a number for equally dividing the assist torque. In other words, it is the number of times the torque is increased to increase the torque in a plurality of times to reach the final assist torque. Therefore, in step 086 following this, the ratio between the predetermined value and the count value of the assist counter is integrated into the assist counter obtained in step 074, and is set as the current target assist torque. That is, when the predetermined value is “n”, the first target assist torque is (1 / n) of the final assist torque obtained in step 074, and the second target assist torque is (2 / n) of the final assist torque. ) Is the target assist torque, and the target assist torque becomes (n / n) of the final assist torque in the last n-th operation.

Steps 081 to 086
When the count value of the assist counter reaches the predetermined value by performing the control of step 085 a plurality of times, step 085 is performed.
Is negative, and in this case, the process returns without performing the control of step 086. Therefore, the assist torque is gradually increased.

To rotate the engine 1 to start it, the torque to which the assist torque is added is applied to the motor
It must be output by the generator 3. For this purpose, the torque control of the motor generator 3 is performed by a motor torque command calculation process in step 065. FIG. 12 shows a motor torque command calculation processing subroutine. When the assist torque is determined as described above, the assist torque is added to the drive request torque for traveling at that time, and the sum is output as a motor torque command value (step 091). Specifically, M / G-ECU 9 and / or battery ECU 1
1 controls the current value to the motor generator 3.

The assist torque described above is a torque based on the inertia torque obtained from the motoring torque obtained from the map and the rate of change of the engine speed NE at that time. For example, the output torque of the motor generator 3 may be insufficient due to such factors. This situation appears as a decrease in the engine speed NE, and may be felt as a feeling of deceleration. So, in such a case,
Increase the motor torque command value. Step 066
Are the control steps for this, and the specific contents are shown in FIG.

FIG. 13 shows a subroutine for the motor speed increase guard process.
In step 1, the amount of increase in the motor speed NM is calculated. This can be determined by monitoring the motor speed NM input to the M / G-ECU 9. Next, it is determined whether or not the increase of the motor speed NM is negative (step 102). If a negative determination is made in step 102, it means that the motor speed NM has not decreased, and the routine returns without performing any particular control.

On the other hand, if an affirmative determination is made in step 102, it means that the motor speed NM has decreased, and the absolute value of the calculated motor speed increase is multiplied by a coefficient. To obtain an increase minus guard torque (step 103). Here, the coefficient is a numerical value for replacing the absolute value of the motor rotation speed increase amount (that is, the decrease amount or reduction rate of the motor rotation speed) with the torque required to prevent the motor rotation speed from decreasing. This is a value set in advance. The thus obtained increase minus guard torque is added to the motor torque command value to obtain a new motor torque command value (step 104). Therefore, the amount of increase in the torque is proportional to the rate of decrease in the motor speed NM.

Incidentally, the above-described processing relating to the assist torque in steps 064 to 066 is continued until the engine speed NE becomes stable even when the hydraulic pressure maximum flag F8 is turned on. That is, if a negative determination is made in step 062, step 06
Proceed to 4 to perform a process for the assist torque.

The motor torque command value determined in the above-mentioned step 063 or step 066 is
Is calculated based on the state of rotation of the motor generator 3, and may exceed the torque that the motor generator 3 can actually output. Therefore, the following control is executed following the control in step 063 or step 066. That is, it is determined whether the motor torque command value determined in step 063 or step 066 exceeds the motor torque guard value (step 067). This motor torque guard value is an upper limit value of the torque that can be actually output by the motor generator 3.

Therefore, if the motor torque command value exceeds the motor torque guard value, the motor torque guard value is adopted as the motor torque command value and the motor torque guard flag F9 is turned on (step 068). Conversely, if the motor torque command value is equal to or less than the motor torque guard value, and a negative determination is made in step 067, the flow advances to step 069 to turn off the motor torque guard flag F9.

Changes in the motor torque command value based on the assist torque described above are shown in FIGS. 7, 14 and 15. That is, as shown in FIG. 7, the motor torque command value is basically set to be a torque obtained by adding the assist torque to the drive torque. The output of the command value is at time t8 after the engine start control flag F2 is turned ON. This control is performed in step 0 described above.
91. By adding the assist torque to the driving torque in this way, the engine 1 can be rotated without decreasing the driving force for traveling, and the driving force when starting to rotate the engine 1 is reduced and the driving force is reduced. Shock can be prevented.

FIG. 14 shows an example of the change in the motor torque command value when the above-described motor rotation speed increase guard processing is performed. When the motor rotation speed NM decreases, the rate of decrease is multiplied by a coefficient. The added torque is added to the assist torque. As a result, the motor torque command value changes as shown by the thick solid line in FIG. Therefore, the number of revolutions of the engine 1 can be continuously increased,
It is possible to prevent a delay in starting the engine and a delay in increasing the driving force for traveling.

Further, by performing the control according to the routine shown in FIG. 11, the change in the motor torque command value when the output of the motor torque command value according to the assist torque is started is reduced as shown in FIGS. )-(C), with a predetermined gradient. That is, since the motor torque does not suddenly change, the shock is effectively prevented.

As shown in the overall control chart of FIG. 2, after the processing of the motor torque is performed, the engine torque processing (step 006) is performed. FIG. 16 shows the engine torque processing subroutine. First, the power-on downshift flag F5
Is determined to be ON (step 111). This determination step is the same as steps 21 and 030 described above.

If an affirmative determination is made in step 111 due to a request for a power-on downshift, it is determined whether or not the engine speed NE is greater than a predetermined reference speed N4 (step 112). . This reference rotation speed N4 is a rotation speed smaller than the motor rotation speed NM at that time, and is, for example, a value about the idle rotation speed.
In other words, the rotation speed is such that the engine 1 can continue to rotate without stalling by supplying the fuel. If a negative determination is made in step 112, the process returns without performing any processing relating to the engine torque. If an affirmative determination is made, the process returns to step 114.
Proceed to.

On the other hand, if a negative determination is made in step 111 because the downshift is not requested, it is determined whether or not the hydraulic pressure maximum flag F8 is ON (step 113). This flag F8 is a flag that is turned on when it is determined that the engine speed NE is synchronized with the motor speed NM, as described with reference to FIG. Therefore, if a negative determination is made in step 113,
Since the engine rotational speed NE is not synchronized with the motor rotational speed NM, in this case, the control returns without performing any control on the processing of the engine torque. On the other hand, if a positive determination is made in step 113, the engine speed N
Since E is synchronized with the motor speed NM, the process proceeds to step 114 in this case.

In step 114, injection of fuel in the engine 1 is started. That is, when a downshift is requested, fuel injection is started when the engine speed NE reaches a predetermined reference speed N4, which is approximately equal to the idle speed. In a normal case where a downshift is not required, fuel injection is started when a determination is made that the engine speed NE is synchronized with the motor speed NM. If the engine does not include the fuel injection device, the supply of fuel is started.

Next, the engine torque command value is obtained by subtracting the motor torque command value from the drive request torque (step 115). The drive request torque is a torque required for traveling, and is obtained based on an accelerator pedal depression amount and the like. The motor torque command value is
The motor torque command value obtained in step 065 or step 066 described above or the motor torque command value swept down in step 063.

FIG. 8 shows the timing of the fuel injection described above. That is, when the power-on downshift is requested and the power-on downshift flag F5 is ON, the fuel injection is started at time t8 when the engine speed NE reaches the reference speed N4, which is about the idle speed. Be started. At the same time, the fuel injection flag is set to ON. On the other hand, during a normal time when a downshift is not required, as shown by a thin solid line in FIG. 8, the supply of fuel is started at time t4 when the maximum hydraulic pressure flag F8 is controlled to be ON.

FIGS. 7, 14 and 15 show changes in the engine torque command value when the above-described engine torque processing is performed. The engine torque command value is controlled such that the sum with the motor torque command value becomes the drive request torque. In other words, the engine torque command value is increased as the motor torque command value decreases. Therefore, a predetermined time T3 from the time t4 when it is determined that the engine speed NE is synchronized with the motor speed NM until the stability of the engine speed NE is determined.
During this period, the motor torque command value is maintained at the immediately preceding value, and accordingly, the engine torque command value is also maintained at the same value as before.

Thereafter, the motor torque command value is swept down, so that the engine torque command value is increased in accordance with the decrease amount of the motor torque command value. As a result, the required driving torque is finally satisfied by the engine torque, and the motor torque command value becomes zero at time t5. At the same time, the input clutch engagement end flag F3 is turned on. That is, the power source is switched from the motor generator 3 to the engine 1 while the driving torque is kept constant. Therefore, it is possible to prevent a shock from occurring when the engine 1 is started and the power source is switched to the engine 1.

As described above, when the power-on downshift is requested, the control of the input clutch 5, the motor torque or the engine torque is made different from the normal case. This is because there is a demand for increasing the driving force due to the downshift. However, a change in the driving force due to the downshift causes a shock to occur. Therefore, when the engine 1 is rotated by the motor torque, the downshift is controlled as follows.

FIG. 17 shows a subroutine of the downshift start permission processing shown in FIG. 2, and it is first determined whether or not the power-on downshift flag F5 is ON (step 121). This judgment step is the same as steps 21, 030 and 111 described above. This step 1
If a negative determination is made at 21, the control returns without performing any control, and if a negative determination is made,
It is determined whether the engine speed NE is greater than a preset reference value N4 (step 122). This reference value N4 is the same as the reference value for determining the fuel injection timing when a downshift request is made. Therefore, in step 122, the point is to determine whether or not the engine 1 has been substantially started. . Since the reference value N4 has a difference in the control response between the engine 1 and the transmission 13,
They need not necessarily be the same, and may be different as needed.

If a negative determination is made in step 122, the routine returns without performing any particular control. Conversely, if the determination in step 122 is affirmative, the downshift start permission flag F10 is turned on (step 1).
23). The downshift control is started by the T / M-ECU 15 based on the downshift start permission flag F10. That is, the downshift is prohibited until fuel is supplied to the engine 1 and the engine 1 is substantially started, and the downshift is started after the engine 1 is substantially started. Therefore, it is possible to prevent a change in driving force due to a downshift in a state where a load for rotating the engine 1 is applied to the motor / generator 3, thereby preventing a shock. Further, when controlling the input torque to the transmission 13 during shifting, since the engine 1 has already been started and outputs torque, the control of the input torque becomes easy, and also in this respect, the shock associated with shifting can be prevented.

In the above example, when the assist torque is added to the motor torque, the control is performed so that the assist torque is gradually increased. This is to prevent a shock due to a sudden increase in torque. On the other hand, the engine 1 is started because a large driving force is required. Therefore, when adding the assist torque to the motor torque, it is preferable to increase the assist torque increase rate within a range that does not deteriorate the shock. An example will be described below.

FIG. 18 shows step 086 of the assist torque processing subroutine shown in FIG.
This is the routine replaced by 86-1. That is, the control executed in step 086-1 is a control in which a predetermined ratio of the assist torque calculated in step 074 shown in FIG. 10 is output as the first command value, and thereafter the assist torque is gradually increased. is there. More specifically, the assist torque calculated as the sum of the motoring torque and the inertia torque is multiplied by the skip-up rate to obtain an assist torque amount to be increased first. The skip-up rate is a value that is set in advance so that the amount of torque increase is such that no shock occurs. The skip-up rate may be a fixed value, or may be a value (that is, a variable) determined in the form of a map using the vehicle speed and the like as parameters.

The assist torque is gradually increased starting from the motor torque command value skipped up as described above. That is, as described in step 086-1 of FIG. 18, the assist torque to be finally set is multiplied by (1−skip-up rate), and the value is further multiplied by the ratio of the assist counter value to the upper limit value of the assist counter. Multiply. Explaining this qualitatively, control is performed to repeatedly increase the remaining amount of the assist torque after skipping up by the value divided by the upper limit value of the assist counter.

FIG. 15 shows a change in the motor torque command value when such an assist torque command value skip-up is performed. That is, by skipping up, the motor torque command value increases from the state of (a) to the state shown in (d). In this case, the motor torque command value and the motor torque sharply increase within a certain range, but no shock occurs by setting the skip-up rate to an appropriate value. Thereafter, the motor torque command value and the motor torque increase by the value divided based on the assist counter upper limit value.

Therefore, since the torque for rotating the engine 1 increases quickly, the engine speed NE increases quickly, the engine 1 outputs the torque early, and the feeling of control delay is avoided. In FIG. 15, (a)-
The change in the motor torque command value shown in (b)-(c) is a change when the processing shown in FIG. 11 or the processing shown in FIG. 18 is not performed, and when the assist torque is large, that is, the motor torque command value If the change width is large, the output shaft torque may temporarily change greatly, causing a shock.

To increase the engine speed NE, the motor torque command value is set to a value obtained by adding the assist torque to the drive request torque, as described with reference to FIG. On the other hand, the motor speed N of the engine speed NE
Synchronization with M is determined by a state in which the difference between the rotational speeds NE and NM becomes equal to or less than a predetermined value for a certain period of time. Therefore, even if the engine speed NE temporarily exceeds the motor speed NM, synchronization is not immediately determined. Therefore, if the motor torque to which the assist torque for rotating the engine 1 is added is continuously output, the motor torque becomes relatively excessive, so that a shock may occur. The control shown in FIG. 19 is a control for avoiding such inconvenience.

The routine shown in FIG. 19 is a motor torque command calculation processing subroutine included in the motor torque processing in step 005 shown in FIG. First,
It is determined whether the engine speed NE is greater than the motor speed NM (step 141). As previously mentioned,
Since the assist torque is added to increase the engine speed NE to the motor speed NM, if the engine speed NE reaches the motor speed NM, it is not necessary to further increase the engine speed 1 further. Therefore, if an affirmative determination is made in step 141, the motor torque command value is set to a value corresponding to the drive request torque (step 142). Conversely, if the engine speed NE is equal to or less than the motor speed NM, the motor torque command value is set to a value corresponding to the torque obtained by adding the drive request torque and the assist torque (step 143).

Changes in the motor torque command value when the control shown in FIG. 19 is performed are shown in FIGS. 7 and 20 (A). As shown in these figures, the engine speed NE
Is higher than the motor rotation speed NM, the assist torque is deleted from the motor torque, and only the driving torque for traveling is output. When the engine speed NE falls below the motor speed NM again, a motor torque in which the assist torque is added to the drive torque is output. as a result,
Since the assist torque is not output in a state where the engine speed NE exceeds the motor speed NM, it is possible to prevent the driving force from becoming temporarily excessive and from causing a shock.

On the other hand, as shown in FIG. 20B, when the assist torque is continuously output regardless of the magnitude of the engine speed NE, the drive is performed when the engine speed NE exceeds the motor speed NM. Excessive torque can cause shock.

If the engine speed NE exceeds the motor speed NM and then the engine speed NE becomes lower than the motor speed NM and the assist torque is added again, the assist torque processing shown in FIG. It is preferred to do so. When such a torque processing is performed, the motor torque gradually increases as shown by the thick solid line in FIG. 20A, so that a shock due to a sudden change in the driving force can be prevented.

By the way, as described with reference to FIG. 9, there is a limit to the torque that can be output by the motor generator 3, and when the motor torque command value exceeds the upper limit torque of the motor generator 3, Adopts a motor torque guard value as a motor torque command value. Even in such a case, if the motor torque is maintained at the upper limit, the driving torque increases because the engine speed NE exceeds the motor speed NM. That is, when the engine speed NE exceeds the motor speed NM, the torque used to rotate the engine 1 of the motor torque is added to the drive torque for traveling, so that the drive torque increases. This may cause a shock.

FIG. 21 is a flowchart showing a motor torque command calculation processing subroutine when the motor torque command value has reached the motor torque guard value.
First, it is determined whether or not the engine speed NE exceeds the motor speed NM (step 151). If a positive determination is made in step 151, it is determined whether the motor torque guard flag F9 is ON (step 1).
52). The motor torque guard flag F9 is a flag that is turned ON when the motor torque command value exceeds the motor torque guard value, as described with reference to FIG.

If the motor torque command value does not exceed the motor torque guard value and a negative determination is made in step 152, a motor torque command value corresponding to the required driving torque is output (step 153). That is, the state of the vehicle when a negative determination is made in step 152 is that there is still room for the torque that can be output from the motor generator 3 and that the engine speed NE is equal to the motor speed N
Since the motor torque exceeds M, the motor torque command value is set to a command value corresponding to the required drive torque. this is,
The control is similar to that of step 142 in FIG.

Conversely, if the motor torque guard flag F9 is ON and the determination in step 152 is affirmative, the motor torque command value corresponding to the torque obtained by subtracting the assist torque from the motor torque limit value is set. Output (Step 154). In addition, the torque subtracted from the motor torque limit value is not limited to the assist torque, and may be a predetermined value. This is because the value obtained by adding the drive request torque and the assist torque does not always exactly match the motor torque limit value.

If the result of the determination in step 151 is negative because the engine speed NE does not exceed the motor speed NM, a motor torque command value corresponding to the torque obtained by adding the assist torque to the drive request torque is output. (Step 155). This corresponds to step 143 in FIG.
Is the same control as.

FIG. 22 shows changes in the motor torque when the control in step 154 is executed and when it is not executed. FIG. 22A illustrates the above step 154.
Shows the change in the motor torque when the control is executed. When the engine speed NE exceeds the motor speed NM, the torque corresponding to the assist torque is subtracted from the motor torque limit value. Therefore, of the torque output by motor / generator 3, engine 1
Since the torque used to rotate the motor is reduced from the motor torque by making it unnecessary, the driving torque does not increase relatively, and thus the driving torque temporarily increases. Can be prevented. Step 1
When the control at step 54 is not executed, as shown in FIG. 22B, the drive torque relatively increases in a state where the engine speed NE exceeds the motor speed NM. May be done.

Here, the correspondence between the above-described specific example and the structure of the claims will be described together. The above-described engine 1 corresponds to the internal combustion engine of the present invention, the motor generator 3 corresponds to the electric motor, the input clutch 5 corresponds to the clutch means of the present invention, and the transmission 13 corresponds to the automatic transmission of the present invention. Is equivalent to The output shaft 4 of the motor generator 3, the automatic transmission 13 connected thereto and the output shaft 16 thereof correspond to the power transmission system of the present invention.

The function of step 001 shown in FIG. 2 corresponds to the start request judging means in claim 1.
The function of step 074 shown in (1) corresponds to the assist amount setting means in claim 1. Regarding claim 2, FIG.
The function of step 141 of FIG. 21 and the function of step 151 of FIG. 21 correspond to the synchronization detecting means.
Corresponds to the function of step 142 in FIG. 19 and step 154 in FIG.

In the specific example described above, a hybrid vehicle having a structure in which the output shaft of the engine is connected to the output shaft of the motor / generator via the input clutch is intended.
The present invention is not limited to the above example, and can be applied to a hybrid vehicle configured to connect an internal combustion engine to a power transmission mechanism or an electric motor via a gear mechanism,
In short, what is necessary is just to apply what is called a parallel hybrid type drive device. Therefore, when determining the operating state of the internal combustion engine and the electric motor, in the above example, the respective rotation speeds are directly compared, but a gear mechanism is interposed between the power transmission device and the electric motor or the internal combustion engine. If so, the operating state of the electric motor and the internal combustion engine may be determined by comparing one of the rotation speeds with a predetermined value based on the other rotation speed. The “reference value determined based on the number of rotations of the electric motor” in claim 1 means this.

[0119]

As described above, according to the first aspect of the present invention, when the internal combustion engine is started while traveling by the electric motor, the torque output from the electric motor is used to maintain the traveling state. Since the required torque is set to a torque obtained by adding a torque determined based on the target rotation speed of the internal combustion engine, a reduction in driving force for traveling is prevented, and a shock accompanying the start of the internal combustion engine can be avoided. it can.

According to the second aspect of the present invention, when the internal combustion engine is started and its rotation speed reaches the rotation speed of the electric motor, the running can be maintained by the output of the internal combustion engine. By reducing the output torque of the hybrid vehicle, it is possible to prevent the driving force of the hybrid vehicle as a whole from becoming excessive, to prevent shock, and to reduce the driving force of the hybrid vehicle as a whole before and after the start of the internal combustion engine. The force becomes constant, so that it is possible to prevent a sudden change in the driving force and a shock resulting therefrom.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a hybrid drive device and a control system thereof according to the present invention.

FIG. 2 is a flowchart showing an overall control routine for starting an internal combustion engine during running with the output of an electric motor.

FIG. 3 is a flowchart showing a part of a subroutine for hydraulic pressure processing of an input clutch.

FIG. 4 is a flowchart showing another part of the subroutine.

FIG. 5 is a flowchart showing still another part of the subroutine.

FIG. 6 is a flowchart illustrating a learning control routine of a supply time of an initial hydraulic pressure.

FIG. 7 is a time chart showing changes in oil pressure, rotation speed, or flag when the control shown in FIG. 2 is executed.

FIG. 8 is a time chart when a power-on downshift is requested.

FIG. 9 is a flowchart showing a motor torque processing subroutine.

FIG. 10 is a flowchart showing a subroutine of an assist torque calculation process.

FIG. 11 is a flowchart illustrating an assist torque processing subroutine.

FIG. 12 is a flowchart illustrating a motor torque command calculation processing subroutine.

FIG. 13 is a flowchart illustrating a motor rotation speed increase guard processing subroutine.

FIG. 14 is a time chart showing a change in a motor torque command value when a control for increasing an assist torque is performed as the motor rotation speed decreases.

FIG. 15 is a time chart showing a change in a motor torque command value when a torque processing process is performed when an assist torque is added to a drive torque.

FIG. 16 is a flowchart showing an engine torque processing subroutine.

FIG. 17 is a flowchart showing a downshift start permission processing subroutine.

FIG. 18 is a flowchart illustrating an assist torque processing subroutine.

FIG. 19 is a flowchart illustrating a motor torque command calculation processing subroutine.

20A is an explanatory diagram illustrating a change in a motor torque command value when the processing in FIG. 19 is performed, and FIG.
20 is an explanatory diagram showing a change in a motor torque command value when the processing shown in FIG. 19 is not performed.

FIG. 21 is a flowchart illustrating a motor torque command calculation processing subroutine.

22A is an explanatory diagram showing a change in a motor torque command value when the process of FIG. 21 is performed, and FIG.
FIG. 22 is an explanatory diagram showing a change in a motor torque command value when the processing shown in FIG. 21 is not performed.

[Explanation of symbols]

1. Engine, 2. Crankshaft, 3. Motor generator, 4. Output shaft, 5. Input clutch,
6: engine ECU, 13: transmission, 14: input shaft, 16: output shaft.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02N 11/04 F02N 11/08 G 11/08 V B60K 9/00 E (72) Inventor Kazumi Hoshiya 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 3G093 AA05 AA06 AA07 AA16 AB00 AB01 BA02 CB08 DA01 DA06 DA14 DB01 DB23 EB00 EB03 FA00 FA10 FA11 5H115 PA01 PG04 PI16 PI21 PU16 PU26 QE01 TB01 TO04

Claims (2)

[Claims] 1. A drive control device for a hybrid vehicle in which an internal combustion engine is connected to a power transmission system to start the internal combustion engine when the vehicle is traveling by transmitting an output of an electric motor to a power transmission system for traveling. In the above, start request determination means for determining a request to start the internal combustion engine, and when the start request determination means determines that there is a request to start the internal combustion engine, the output torque of the electric motor, the target A motoring torque determined based on the rotation speed of the internal combustion engine or an assist amount setting means for increasing the motoring torque by a torque corresponding to a torque obtained by adding an inertia torque corresponding to the rate of change of the rotation speed of the internal combustion engine to the motoring torque. A drive control device for a hybrid vehicle, comprising: 2. A drive control device for a hybrid vehicle that starts an internal combustion engine by connecting an internal combustion engine to the power transmission system during traveling by transmitting the output of the electric motor to a power transmission system for traveling. In the above, after the internal combustion engine is connected to the power transmission system and start control of the internal combustion engine is started, the rotation speed of the internal combustion engine becomes equal to or higher than a rotation speed of the electric motor or a reference value determined based on the rotation speed of the electric motor. A synchronous detecting means for detecting that the internal combustion engine has reached a rotational speed of the internal combustion engine or a reference value determined based on the rotational speed of the electric motor. Means for decreasing the output torque of the motor increased to start the engine, and the output torque of the motor even when the output torque of the motor is not increased when the internal combustion engine is started. Hybrid vehicle drive control apparatus characterized by comprising at least one of the means of the means for reducing the.