JP3376999B2 - Drive control device 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 which uses, as a power source, an internal combustion engine such as a gasoline engine or a diesel engine and an electric motor such as a motor or a motor / generator that outputs torque by operating with electric power. The present invention relates to a drive control device, and more particularly to a drive control device for a hybrid vehicle of a type in which both an internal combustion engine and an electric motor can be used as power sources for traveling.

[0002]

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

On the other hand, the internal combustion engine does not start only by supplying fuel, but must be forcibly rotated by an external force to start. Therefore, a motor generally called a starter is attached to the internal combustion engine. However, in the above parallel hybrid type vehicle, since the internal combustion engine can be connected together with the electric motor to the power transmission system for traveling,
The electric motor can force the internal combustion engine to rotate, thereby starting the internal combustion engine. Therefore, for example, in a low vehicle speed state such as at the time of starting, in order to prevent deterioration of exhaust gas and improve fuel economy, the vehicle is driven by an electric motor, and when the internal combustion engine is started when the vehicle speed becomes high to some extent, By transmitting the output torque of the used electric motor to the internal combustion engine, it becomes possible to start the internal combustion engine without using a starter that has been generally used in the past. In other words, the starter can be eliminated and the number of parts can be reduced.

An apparatus for controlling the starting of such an internal combustion engine is disclosed in Japanese Patent Laid-Open No. 9-193676. The device described in this publication connects an internal combustion engine to a predetermined rotary element in a planetary gear mechanism via an input clutch, connects a motor / generator to another rotary element, and outputs a third rotary element. This is a device that is premised on a drive device configured as a member. In this conventional device, while the vehicle is traveling by the output of the motor / generator, by engaging the input clutch, torque is transmitted to the internal combustion engine, which is forcibly rotated to start the internal combustion engine. ing.

[0005]

According to the above-mentioned conventional device, the internal combustion engine can be started without using the starter, but when the input clutch is engaged to rotate the internal combustion engine, the vehicle travels. Since a part of the output torque of the electric motor used for the above is consumed as torque (motoring torque and inertia torque) for rotating the internal combustion engine, 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 rotational speed of the electric motor and the rotational speed of the internal combustion engine match, the input clutch is completely engaged. It is generally done. However, even if the rotation speeds of the electric motor and the internal combustion engine match, if the change rates of the rotation speeds (rates of rotation speed increase) differ from each other, the input clutch is completely engaged. After that, one power source with a low rate of increase in rotation speed, that is, the electric motor or the internal combustion engine is dragged by the other power source with a high rate of increase in rotation speed. As a result, a situation similar to that in which the running resistance increases with the complete engagement of the input clutch occurs, and a shock may occur due to a decrease in the driving force.

Further, when the input clutch is engaged to increase the rotational speed of the internal combustion engine while the vehicle is traveling by the electric motor, and fuel is supplied to start the internal combustion engine, combustion occurs in the internal combustion engine. Output torque is
Added to torque for running. Therefore, at that time, if the input clutch has sufficient transmission torque capacity,
Since the output torque of the internal combustion engine is added to the running torque of the electric motor, the driving force suddenly increases, which may be felt as a shock.

As the input clutch, a multi-plate friction clutch that is engaged by hydraulic pressure can be used, and the above publication also exemplifies the multi-plate clutch as the input clutch. When engaging this type of clutch, the valve provided in the hydraulic circuit is switched to supply the hydraulic pressure from the hydraulic source to the clutch. In that case,
Since the line resistance is inevitably generated, there is a time delay from the instruction to engage the input clutch to the actual engagement of the input clutch.

Further, in the input clutch, there are gaps between the friction plates or between the friction plates and the piston that presses the friction plates. Therefore, when hydraulic pressure starts to be supplied to the input clutch, the gap ( Pack clearance) is clogged, and then torque is transmitted between the friction plates. Since the internal combustion engine cannot be rotated while the pack clearance is blocked, there is a time delay in the control for rotating the internal combustion engine. As described above, due to the delay factor in the mechanical structure, the response of the starting control of the internal combustion engine may be deteriorated.

Further, even if the rotational speed of the internal combustion engine becomes the rotational speed at which combustion is continuously generated by the supply of fuel, the internal combustion engine immediately generates torque by the start of supply of fuel and does not perform continuous operation. However, there may be a delay before the torque is generated due to the temperature of the internal combustion engine or the outside air temperature. Such a delay, in combination with the above-described delay of the operation of the input clutch, may deteriorate the responsiveness of the starting control of the internal combustion engine or may cause a so-called wobble feeling due to a delay in the increase of 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 by an electric motor and improving responsiveness. The purpose is to do.

[0012]

In order to solve the above-mentioned problems, the invention described in claim 1 is the one in which the output of the electric motor is transmitted to a power transmission system for traveling and the vehicle is traveling. In addition, connecting the internal combustion engine to the power transmission system ,
In the drive control apparatus for a hybrid vehicle to start the said combustion engine by the output torque of the electric motor, the start request determining means for determining a request for starting of the internal combustion engine, that there was a request for starting the internal combustion engine starting If it is determined by the request determining means, the output torque of the motor, determine Mari based on the rotation speed of the internal combustion engine to the target, or
One, the motoring torque required to the internal combustion engine to rotate, assisted also properly is to increase by torque corresponding to the torque obtained by adding the inertia torque corresponding to the rotational speed change rate of the internal combustion engine to the motoring torque And a quantity setting means.

Therefore, according to the first aspect of the present invention, when the internal combustion engine is rotated by the output torque of the electric motor in order to start the internal combustion engine, the output torque of the electric motor or the torque for rotating the internal combustion engine is insufficient. Can be detected by a decrease in the number of rotations of the motor, and the output torque of the electric motor is increased based on the detection result, so that a temporary shortage of the driving force during traveling and a shock resulting therefrom can be prevented.

The invention of claim 2 is based on the structure of claim 1.
In addition, after starting the starting control of the internal combustion engine by connecting the internal combustion engine before Symbol driveline, the rotational speed of the internal combustion engine is equal to or greater than the reference value determined based on the number of revolutions or motor of the electric motor When the synchronous detection means detects that the rotational speed of the internal combustion engine has become equal to or higher than a reference value determined based on the rotational speed of the electric motor or the rotational speed of the electric motor. At least means for reducing the output torque of the electric motor increased to start the internal combustion engine and means for reducing the output torque of the electric motor even when the output torque of the electric motor is not increased when starting the internal combustion engine. One of the means is provided.

Therefore, according to the second aspect of the present invention, when the internal combustion engine is being rotated by the electric motor to start the internal combustion engine, the excess or deficiency of the output of the electric motor is constantly monitored as its rotational speed to output the electric power of the electric motor. When the number of rotations decreases due to lack of, the output of the electric motor is increased.
The temporary decrease in driving force and the resulting shock can be prevented . The invention of claim 3 is the same as claim 1 or
In addition to the configuration of 2, the determination result of the start request determination means
Based on the output shaft of the internal combustion engine and the output of the electric motor
The transmission torque capacity of the coupling mechanism that selectively couples the shaft is controlled.
Characterized in that it further comprises means for controlling
is there. According to the invention of claim 3, according to the invention of claim 1 or 2,
The same effect as light occurs.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION 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 electric power. Here, the internal combustion engine is, in essence, a power source that burns fuel to output power, specifically, a gasoline engine, a diesel engine, or a gas engine that uses a gaseous fuel such as hydrogen gas, Further, the type thereof is not limited to the reciprocating engine and may be a turbine engine or the like. In the following description, the internal combustion engine will be referred to as “engine”.

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

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

The power transmission system is, in essence, a mechanism for transmitting a driving force to wheels for traveling, and may not be provided with a transmission or may be provided with a transmission. If the transmission is provided, the driving force can be controlled in the power transmission system. As the transmission, it is possible to use a manual transmission that changes the transmission ratio by a manual operation or an automatic transmission that controls the transmission ratio according to the traveling state such as vehicle speed and engine load. Not only the stepped transmission that changes the gear ratio stepwise,
It is also possible to use a continuously variable transmission in which the gear ratio continuously changes. In the following example, an automatic transmission is used.

FIG. 1 is a block diagram schematically showing a drive control device according to the present invention, in which an output shaft (that is, a crankshaft) 2 of an engine 1 is a motor generator 3.
Is connected to the output shaft 4 via an input clutch 5. The input clutch 5 corresponds to the clutch means in the present invention and is a connecting mechanism for selectively connecting the output shafts 2 and 4. More specifically, as the input clutch 5, 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. In addition, 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 its supply / discharge.
Is provided.

The engine 1 in the example shown in FIG. 1 is an engine for electrically controlling ignition timing, fuel supply amount (fuel injection amount), idle speed, valve timing, etc. Control device (engine EC
U) 6 are provided. This electronic control unit 6 is a device mainly composed of a microcomputer, and is inputted with data such as intake air amount, accelerator position, engine water temperature, engine speed NE, etc., and is inputted with previously stored data and programs. It is configured to determine and output a control amount such as ignition timing based on the obtained data.

The engine 1 also includes an electronic throttle valve 7 for electrically controlling the throttle opening. The electronic throttle valve 7 is a valve whose opening is controlled by a control amount calculated based on various 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. The electronic control unit 8 is also mainly composed of a microcomputer.

The motor / generator 3 has a known structure in which a rotor integral with the output shaft 4 is rotatably arranged on the inner peripheral side of a stator having a coil, and a resolver for detecting the rotation of the rotor is provided. The rotor is normally or reversely rotated by controlling energization of the coil, and its torque is controlled, and an electromotive force is generated by rotating the rotor by an external force. . In order to control the motor / generator 3, an electronic control unit (M / G-ECU) 9 mainly including a microcomputer is provided. For example, the rotation speed (motor rotation speed) NM of the motor generator 3 is input to the electronic control unit 9 as control data.

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

Output shaft 4 of the motor / generator 3 described above
The input shaft 14 of the transmission 13 is connected to. This Figure 1
In the example shown in (1), as the transmission 13, an electronically controlled automatic transmission in which the gear ratio is controlled based on the traveling state is adopted. That is, the transmission 13 determines a gear ratio based on data such as throttle opening, vehicle speed or shift pattern, shift range, and the like, and a friction engagement device (not shown) such as a clutch or a brake to achieve the gear ratio. No.) is controlled by hydraulic pressure. An electronic control unit (T / M-ECU) 15 mainly including a microcomputer is provided for the control.

The output shaft 16 of the transmission 13 is connected to the wheels via a propeller shaft, an axle, etc. (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 the power transmission system in the present invention.

Each of the electronic control devices 6, 8, 9, 11,
Reference numeral 15 is connected to a hybrid controller (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
It is configured to control the driving force of the hybrid vehicle by comprehensively controlling the gear ratio by. That is, the hybrid controller 17 is provided with a program for inputting / outputting data required for the control and for processing the data.

A hybrid vehicle is a vehicle developed mainly for the purpose of improving fuel efficiency and cleaning exhaust gas. It runs at the output of a motor at a low vehicle speed and at a constant vehicle speed above a predetermined vehicle speed. When the vehicle travels, it travels with the output of the engine, and when a larger driving force is required, it travels with the output of the engine and the motor. Therefore, the engine is started while traveling by the motor, but when the power transmission system is configured as shown in FIG. 1 described above, the motor torque is transmitted to the engine to rotate the engine. As a result, the engine can be started.

Therefore, the drive control device according to the present invention controls the starting of the engine 1 as described below. Figure 2
Is a flow chart showing an overall control routine for controlling the engine 1 to be connected to a power transmission system for starting control of the engine 1, that is, for controlling the engagement of the input clutch 5. It is repeated every time.

First, at step 001, it is judged if 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 further driven by the motor / generator 3. At this time, the engine start request flag F1 is turned ON when the accelerator pedal (not shown) is stepped on greatly and there is a request to increase the driving force.

When the affirmative judgment 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). On the contrary, the engine start request flag F1 is OFF
Therefore, if the determination in step 001 is negative, 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 this step 003, and in this case, this routine is ended. Also, the engine start control flag F2 has already been
After turning ON, when the judgment of step 001 is made again, a negative judgment is made because the engine start request flag F1 has been switched to OFF, but since the engine start control flag F2 is already ON, step 00
An affirmative decision is made at 3.

After the engine start control flag F2 is turned ON in the above step 002, or when an affirmative judgment is made in step 003, the hydraulic pressure process of the input clutch 5 (step 004) and the motor torque process (step 00).
5), engine torque processing (step 006) and downshift start permission processing (step 007). Each processing of these steps 004 to 007 will be described later.

Then, it is judged whether or not the engagement end judgment 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 the power transmission system, the engine 1 is in a state where it continues to rotate by the supply of fuel, or the torque of the motor / generator 3 is reduced accordingly. It can be determined that the input clutch 5 is completely engaged by starting the operation. And this step 0
If a negative determination is made in 08, that is, if the engagement of the input clutch 5 is not completed, this routine is exited and the processing of steps 004 to 007 is continued. On the contrary, if the positive determination is made in step 008 because the engagement of the input clutch 5 is completed,
The control for switching the engine start control flag F2 to OFF and the ON signal of the engagement end determination flag F3 are output (step 009), and the engagement process of the input clutch 5 is completed.

When there is a request for starting the engine 1, the engine 1 is rotated by the motor torque by engaging the input clutch 5 and connecting the engine 1 to the power transmission system. In that case, the driving force changes suddenly. The hydraulic pressure of the input clutch 5 is controlled as described below in order to prevent a shock due to 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 along with the execution of the routine shown in FIG.
Therefore, in step 011 it is judged whether or not this subroutine is executed for the first time. When the hydraulic pressure process for engaging the input clutch 5 is started, an affirmative decision is made in this step 011. On the contrary, when the hydraulic pressure process for engaging the input clutch 5 has already started, FIG. Since the routine shown in FIG. 5 is executed for the second time and thereafter, a negative determination is made in step 011.

When the affirmative decision is made in step 011, the fast / quick fill flag (FQF flag) F4 is turned ON (step 012) and then 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.

The FQF flag F4 is a flag which is set to 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 ended. Also, this initial hydraulic pressure supply control is
In order to quickly close the gap between the friction plates (not shown) of the input clutch 5 and the gap between the piston (not shown) and the friction plate, a preset high hydraulic pressure is supplied as the initial hydraulic pressure. Control. In step 013, it is determined whether or not the FQF flag F4 is ON in order to determine the start or end of the initial hydraulic pressure supply control.

If the FQF flag F4 is ON due to the determination that the input clutch 5 is started to be engaged, step 0
When the determination in step 13 is affirmative, in which case it is instructed to output the fast quick fill hydraulic pressure (FQF hydraulic pressure) as the initial hydraulic pressure (step 014). Input clutch 5
An electrically controllable valve such as a duty solenoid valve (linear solenoid valve) can be used as a means for controlling the hydraulic pressure of the solenoid valve. When such a solenoid valve is used, the control of step 014 is performed. Is a control for temporarily increasing the command signal. The command signal is a signal having a predetermined value. The command signal does not have to be a fixed value, and may be a value (that is, a variable) set as a map value according to conditions such as oil temperature.

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

On the contrary, if the affirmative determination is made in step 015 because the downshift is determined, the supply time of the initial hydraulic pressure for the downshift (command time).
It is determined whether T1 'has passed (step 01).
7). These command times T1 and T1 'are times during which the command signal for supplying the initial hydraulic pressure is continuously output, and the command time T1 for normal time is the command time T for downshift.
It is set shorter than 1 '(T1 <T1'). That is, when the downshift is determined, the supply time of the initial hydraulic pressure becomes long.

When a positive determination is made in step 016 or step 017, that is, when 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 set to O.
Set to N (step 019). On the contrary, the command times T1 and T1 'do not elapse so that the step 01
6 or when a negative decision is made in step 017,
Steps 108 and 019 are skipped and the process proceeds to step 020. That is, the supply control of the initial hydraulic pressure (FQF hydraulic pressure) is continued.

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

At step 020, it is judged if the low pressure standby oil pressure flag F6 is ON. It is a flag that is turned on while the input clutch 5 is on standby in the incompletely engaged state after the supply of the initial hydraulic pressure described above. Therefore, 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 the fully engaged state is maintained, and a negative determination is made in step 020 after the low pressure standby control is completed.

If the affirmative determination is made in step 020 because the low pressure standby hydraulic pressure flag F6 is ON, it is determined whether the power-on downshift flag F5 is ON (step 021). The determination in step 021 is made in the same manner as the determination in step 015 described above. If a negative determination is made in step 021, a command signal for setting the standby hydraulic pressure for normal time is output (step 022). On the contrary, step 02
If the determination is affirmative in step 1, a command signal for setting the standby hydraulic pressure for downshift is output (step 02).
3).

Here, the standby hydraulic pressure is a hydraulic pressure required to make the input clutch 5 stand by in an incompletely engaged state after supplying the initial hydraulic pressure to the input clutch 5. Further, the incomplete engagement state is, for example, an engagement state in which the output torque does not change because the transmission torque capacity is slightly smaller than the loaded torque, or the hydraulic pressure slightly increases, and the load torque is increased. This is an engaged state in which the transmission torque capacity is more prevailing and the output side changes in rotation. Then, the standby hydraulic pressure for downshift is set higher than the standby hydraulic pressure for normal operation.

Therefore, when the downshift is judged, the input clutch 5 is brought into a state closer to the completely engaged state. The command for the low-pressure standby hydraulic pressure is specifically issued by outputting a pulse signal to a duty solenoid valve (linear solenoid valve) that is hydraulic pressure control means. Further, the command signal may be changed according to the oil temperature, in addition to the difference between the normal time and the downshift.

After the control of the standby hydraulic pressure is started as described above, the engine speed NE is set to the predetermined reference speed N1.
It is determined whether or not (step 024). This reference rotation speed N1 is a small value close to zero, and therefore, in this step 024, it is judged whether or not the engine 1 has started to rotate. If a positive determination is made in step 024 as the engine 1 starts rotating,
Learning control of the initial hydraulic pressure supply time (FQF time) is executed (step 025). This learning control will be described later. Further to the learning control, the low pressure standby hydraulic pressure flag F6 is controlled to be OFF (step 027), and the hydraulic pressure sweep up flag F7 is controlled to be ON (step 028).

On the other hand, when the 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 pressure timer is equal to or more than a predetermined reference value (step 026). ). This is a control by a so-called guard timer, and is a control for preventing the standby hydraulic pressure control from continuing unnecessarily for a long time. Therefore, when a positive determination is made in step 026, the process immediately proceeds to step 027 to end the standby pressure control. On the other hand, when the determination in step 026 is negative, the standby pressure control is to be continued, so steps 027 and 028 are skipped and step 0 is skipped.
Proceed to 29. 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 voltage standby control has ended.

The learning control of the FQF time will be described here. As described above, the initial hydraulic pressure is supplied so as to close the gap (pack clearance) in the input clutch 5 and bring it to the state immediately before the start of engagement. However, if the initial hydraulic pressure supply time is short, the pack clearance will not be sufficiently blocked. No
On the contrary, 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 becomes excessively early. Therefore, the initial hydraulic pressure supply time (FQF time) is increased or decreased based on the time from the end of the initial hydraulic pressure supply until the engine 1 starts to rotate, and is set to an appropriate value.

Specifically, the control is performed as shown in FIG.
That is, FIG. 6 shows a subroutine for learning the FQF time, and in the step 018, the FQF flag F4
It is determined whether the time from turning OFF the engine 1 until the rotational speed NE of the engine 1 becomes equal to or higher than the reference rotational speed N1 and an affirmative judgment is made in step 024, that is, the engine starting time T2 exceeds a preset reference time τ1. (Step 051). If a negative determination is made in step 051 because the engine start time T2 is less than or equal to the reference time τ1, 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.

The engine starting time T2 is the second reference time τ
If it is less than 2, the engine 1 starts to rotate 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 decision is made in step 052, the predetermined value ΔT1 is subtracted from the FQF time T1, and the FQF time T decided in step 016 is determined.
Shorten 1 (step 053). That is, the supply time of the next initial hydraulic pressure is shortened to bring the input clutch 5 closer to the released state.

On the other hand, the engine starting time T2 is the first
Since it is longer than the reference time .tau.1, the torque is not sufficiently transmitted to the engine 1 via the input clutch 5 when the affirmative determination is made in step 051.
Therefore, in this case, the FQF time T1 has a predetermined value ΔT1.
Is added 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 close to the engaged state. If the engine start time T2 is proper between the reference times τ1 and τ2, 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. When the control of step 053 or step 054 is performed, the process proceeds 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 started to rotate after the standby oil pressure control was started as described above. When this is detected, the sweep-up control is started. Specifically, as shown in FIG. 4, it is determined whether the hydraulic sweep up flag F7 is ON (step 029). If the hydraulic sweep-up control has started, an affirmative decision is made in step 029, and if the hydraulic sweep-up control has not started or has already finished, a negative decision is made in step 029.

Since the sweep up control for gradually increasing the oil pressure of the input clutch 5 is started, step 029 is executed.
If the affirmative decision is made in step 3, it is decided whether or not the power-on downshift flag F5 is ON (step 03).
0). The step 030 is a judgment step similar to the steps 015 and 021 described above. If the affirmative determination is made in step 030 because the downshift is determined, it is determined whether the engine speed NE is lower than a predetermined reference value N2 (step 031).

This reference value N2 is, for example, a value around the idling speed. Therefore, when the affirmative judgment is made in this step 031, the engine speed NE is increased although the driving 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 in order 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 is not determined, or if the power-on downshift is determined, the engine speed NE is equal to or higher than the reference speed N2. Therefore, when a negative determination is made in step 032, the sweep up gradient of the hydraulic pressure of the input clutch 5 is set to
A normal gradient smaller than the gradient set in step 032 is set (step 033). It should be noted that the normal sweep-up gradient set in step 033 is set in advance so that a delay in engine start control does not occur and the driving force does not decrease due to a rapid increase in engine speed. It is a gradient. Therefore, it is until the engine speed NE reaches the above-mentioned reference value N2 that the gradient of the sweep-up is increased because the downshift is determined.

After the sweep-up gradient is set in step 032 or step 033, the hydraulic pressure command value of the input clutch 5 is swept up according to the set gradient (step 034). Specifically, the duty ratio for controlling the hydraulic 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 continues for a predetermined time. Is determined (step 035). This reference value N3 is a relatively small value, and therefore, at step 035, it is judged whether or not the engine speed NE is substantially synchronized with the speed (motor speed) NM of the motor / generator 3. .

When the engine speed NE is synchronized with the motor speed NM and a positive determination is made in step 035, the hydraulic pressure 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 ended, and the 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 a reference value N3 or more, or when the engine speed NE does not substantially match the motor speed NM, that state does not continue. A negative determination is made in step 035. In this case, step 036 and step 03
Skip 7 and proceed to step 038. That is, the hydraulic sweep-up control is continued. If the hydraulic sweep up flag F7 is OFF, step 029
If a negative determination is made at step 308, the hydraulic pressure sweep-up control itself is not executed, so that step 038 is immediately executed.
Proceed to.

At step 038, it is judged if the maximum oil pressure flag F8 is ON. When the hydraulic pressure sweep-up control of the input clutch 5 is completed, this flag F8 is turned ON. In other cases, that is, when the hydraulic pressure 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 decision 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 making the duty ratio of the command signal maximum or minimum. The maximum oil pressure flag F8 is OF
If the determination is negative in step 038 because it is F, step 039 is skipped, the process proceeds to step 040, and the control immediately before that is continued.

Next, at step 040, it is judged if the engagement end judgment flag F3 of the input clutch 5 is ON or not,
If the flag F3 is not ON, the control for maximizing the hydraulic pressure command value is continued. On the contrary, if the determination flag F3 for the end of engagement of the input clutch 5 is ON, step 04
If the affirmative judgment is made with 0, the hydraulic pressure maximum flag F8 is set to O.
After switching to FF, it returns.

FIG. 7 shows a time chart when the above-described control is executed. Engine start request flag F
When 1 is turned on at time t1, the engine start control flag F2 and 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 hydraulic pressure control, the hydraulic pressure of the input clutch 5 increases as shown by the thin solid line in FIG. 7, and reaches the pressure of the standby hydraulic pressure.

FQ at the time t2 when the FQF time T1 has elapsed
F flag F4 is turned off and low pressure standby pressure flag F
6 is controlled to ON. At this time, 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 is transmitting torque but is in an incompletely engaged state, so that the engine speed NE of the engine 1 does not immediately increase. During the control for maintaining the low-pressure standby hydraulic pressure, the output torque of the motor / generator 3 is increased as described later, and as a result, the engine 1 starts to rotate. This is judged based on the fact that the engine speed NE becomes equal to or higher than the reference value N1 close to zero as described above.

At time t3 when the determination is established, the low pressure standby oil pressure flag F6 is turned off and the oil pressure sweep up flag F7 is turned on. And input clutch 5
The oil pressure sweep-up control is started. That is, the hydraulic command value is swept up. Since the torque for rotating the engine 1 increases as the engagement hydraulic pressure of the input clutch 5 gradually increases, the engine speed NE gradually increases. As a result, when the difference between the engine speed NE and the motor speed NM is kept within the predetermined reference value N3 for a predetermined time, the engine speed NE becomes the motor speed N.
When it is determined that the hydraulic pressure is synchronized with M, the hydraulic pressure sweep-up flag F7 is turned off and the hydraulic pressure maximum flag F8 is turned on at time t4. Along with this, the hydraulic pressure of the input clutch 5 is increased to the line pressure (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 as the end of the control, the engagement end flag F3 of the input clutch 5 is turned ON. At time t5, the engine start control flag F2 and the hydraulic pressure maximum flag F8 are turned off.

On the other hand, FIG. 8 shows a time chart when the judgment of the power-on downshift is established.
In FIG. 8, when the engine start control flag F2 is turned on in response to an engine start request, and the power-on downshift flag F5 is turned on at time t6 when a predetermined time has elapsed from time t1, for example, Initial hydraulic pressure supply control time is F for normal time
FQF time T1 for downshift instead of QF time T1
'Is selected. In addition, the standby hydraulic pressure is set to a pressure higher than the normal pressure. Of the solid lines showing the input clutch command value in FIG. 8, the thick solid line shows the command value at the time of downshift, and the thin solid line shows the command value at the normal time. Further, since the downshift is required, the sweep-up gradient of the hydraulic pressure of the input clutch 5 is increased as compared with the normal time. In the example shown in FIG. 8, the sweep-up gradient is increased until time t7 when the engine speed NE has risen to some extent.

Therefore, when there is a downshift request, the input time of the initial hydraulic pressure (FQF time) T1 'becomes longer, so that the input clutch 5 is controlled to be closer to the engaged state than in the normal state. It Further, since the low-pressure standby hydraulic pressure is higher than that in the normal state, the transmission torque capacity of the input clutch 5 becomes large. As a result, the torque transmitted to the engine 1 is large, so that the engine 1 starts to rotate at an earlier time than the normal time. After that, since the sweep up gradient of the hydraulic pressure of the input clutch 5 is set to be larger than the normal time,
The torque transmitted to the engine 1 is increased faster than usual. That is, the rotation speed of the engine 1 is rapidly raised, and the synchronization of the engine rotation speed NE with the motor rotation speed NM and the start-up of the engine 1 are achieved early. Along with this, the traveling by the engine 1 becomes possible at an early stage, and the control that meets the demand for increasing the driving force is achieved.

Next, the motor torque processing executed in step 005 will be described. This control is a control for preventing a shock and a delay in starting the engine 1 due to a change in driving force. The torque control of the motor / generator 3 for rotating the engine 1 and the engine 1 are performed.
And the gradual reduction control of the torque of the motor-generator 3 after the start of the above is completed. That is, FIG. 9 is a flowchart showing the motor torque processing subroutine.
It is determined whether the maximum oil pressure flag F8 is ON (step 061). As described above, this hydraulic maximum flag F8
Is a flag that is ON-controlled by determining that the engine speed NE is in synchronization with the motor speed NM. Therefore, if this flag F8 is ON, the substantial start of the engine 1 is completed and the engine is 1 rotates by its own output and outputs torque. On the contrary, if the maximum oil pressure flag F8 is OFF, it means that the engine speed NE has not reached the motor speed NM.

If an affirmative decision 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 3 has elapsed (step 062).
At this time T3, the engine speed NE is the motor speed N
In synchronization with M, fuel is supplied to engine 1
Is the time required for the rotation of the engine 1 to stabilize after starting to rotate. 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 is changed.
The stable state of the engine speed NE may be determined based on the detected value of E.

When the affirmative judgment is made in step 062, the rotation of the engine 1 is stabilized. 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 control for switching from traveling by the motor / generator 3 to traveling by the engine 1, as will be described later.

On the other hand, when the maximum hydraulic pressure flag F8 is OFF and a negative determination is made in step 061,
An assist torque calculation process (step 064), a motor torque command calculation process (step 065), and a motor rotation speed increase guard process (step 066) are performed by the motor / generator 3. When the engine 1 is started while traveling 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, this assist torque is calculated.

FIG. 10 is a flow chart showing the subroutine of the assist torque calculation. First, the 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 and the number of rotations to rotate. 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 obtain the motoring torque.

Next, the rate of increase of the engine speed NE is calculated (step 072). This is calculated based on the 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 engine speed increase rate is calculated based on the difference or ratio between the previous detected value and the present detected value. The inertia torque is calculated by multiplying the engine speed increase rate thus obtained by a proportional constant (step 07).
3). In order to increase the engine speed NE to the target speed, the motoring torque and the inertia torque that causes the rotation change are necessary. Therefore, the motoring torque and the inertia torque obtained as described above are used. In addition, the assist torque is set (step 074).

The assist torque is supplied to the motor / generator 3
When the output torque is added to the output torque, the assist torque is processed to prevent a sudden change in the torque (step 075). FIG. 11 is a flow chart showing the subroutine of this assist torque processing process. This assist torque processing process is a transient control when increasing the output torque of the motor generator 3, and therefore is executed when the assist torque is zero or more. That is, in step 081, it is determined whether or not the assist torque is greater than zero, and if the assist torque is less than or equal to zero and a negative determination is made in step 081,
I will return. On the other hand, if the affirmative determination is made in step 081 because the assist torque is greater than zero, it is determined whether or not the first routine is executed as the processing of the assist torque started this time (step 082). .

When an affirmative decision is made in step 082, the assist counter is cleared and counting is newly started (step 083). On the contrary, if a negative determination is made in step 081, it means that the counting by the assist counter has already been started. Therefore, in this case, the process proceeds to step 084 to count up by the assist counter.

Then, it is determined whether or not the count value of the assist count is smaller than a predetermined value (step 085). Here, this predetermined value is a number that evenly divides the assist torque. In other words, it is the number of times the torque is increased in order to increase the torque in a plurality of times to reach the final assist torque. Therefore, in the subsequent step 086, the ratio between the predetermined value and the count value of the assist counter is integrated into the assist counter obtained in step 074 to obtain 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 final n-th time.

Steps 081 to 086
When the count value of the assist counter reaches the above-mentioned predetermined value by performing the above control a plurality of times, step 085
If NO, the process returns to step 086 without performing the control. Therefore, the assist torque is gradually increased.

In order to rotate the engine 1 to start it, the torque to which the assist torque is added is applied to the motor.
It is necessary to output by the generator 3. The torque control of the motor generator 3 for that purpose is performed by the motor torque command calculation processing 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 the motor torque command value (step 091). Specifically, the M / G-ECU 9 and / or the battery ECU 1
1 controls the current value for the motor generator 3.

The assist torque mentioned above is a torque based on the inertia torque calculated from the motoring torque obtained from the map and the rate of change of the engine speed NE at that time. The output torque of the motor / generator 3 may be insufficient due to such reasons. This situation appears as a decrease in the engine speed NE and may be felt as a feeling of deceleration. So in this case,
Increase the motor torque command value. Step 066
Is a control step therefor, and its specific content is shown in FIG.

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

On the other hand, if the affirmative judgment is made in step 102, it means that the motor rotation speed NM has decreased, so the absolute value of the motor rotation speed increase amount obtained by the calculation is multiplied by a coefficient. Then, the rising minus guard torque is obtained (step 103). Here, the coefficient is a numerical value for replacing the absolute value of the motor rotation speed increase amount (that is, the motor rotation speed decrease amount or decrease rate) with the torque required to prevent the decrease of the motor rotation speed. It is a preset value. The rise minus guard torque thus obtained is added to the motor torque command value to obtain a new motor torque command value (step 104). Therefore, the amount of increase in torque is proportional to the rate of decrease in the motor speed NM.

By the way, the processing relating to the assist torque in steps 064 to 066 described above continues until the engine speed NE stabilizes even if the hydraulic pressure maximum flag F8 is turned on. That is, when a negative determination is made in step 062, step 06
Then, the process proceeds to step 4 and the assist torque is processed.

The motor torque command value determined in step 063 or step 066 is the engine 1
Is a value calculated by calculation based on the state of rotation of the motor, and may exceed the torque that the motor generator 3 can actually output. Therefore, the following control is executed following the control of the above step 063 or step 066. That is, it is determined whether or not 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 the upper limit value of the torque that the motor generator 3 can actually output.

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). On the contrary, if the motor torque command value is less than or equal to the motor torque guard value, and if a negative determination is made in step 067, the process proceeds to step 069 to turn off the motor torque guard flag F9.

Changes in the motor torque command value based on the above assist torque 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.
It is based on 91. By adding the assist torque to the driving torque in this way, the engine 1 can be rotated without reducing the driving force for traveling, and the driving force is reduced when starting the rotation of the engine 1 Shock can be prevented.

An example of the change in the motor torque command value when the above-described motor rotation speed increase guard processing is performed is as shown in FIG. 14, and when the motor rotation speed NM decreases, the decrease rate is multiplied by a coefficient. 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 rotation speed 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 motor torque command value corresponding to the assist torque starts to be output is changed from (a) to (e) in FIG. )-(C) changes with a predetermined slope. That is, since the motor torque does not change abruptly, a shock is effectively prevented.

By the way, as shown in the overall control chart of FIG. 2, the engine torque processing (step 006) is performed after the motor torque processing. FIG. 16 shows the engine torque processing subroutine. First, the power-on downshift flag F5.
It is determined whether or not is ON (step 111). This determination step is the same as steps 021 and 030 described above.

When an affirmative decision is made in step 111 due to the power-on downshift request, it is decided whether or not the engine speed NE is higher than a predetermined reference speed N4 (step 112). . This reference rotational speed N4 is a rotational speed lower than the motor rotational speed NM at that time, and is, for example, a value around the idle rotational speed.
In other words, the number of rotations is such that the engine 1 can continue to rotate without stall by supplying the fuel. When a negative determination is made in step 112, the process returns without performing any processing relating to the engine torque, and when a positive determination is made, step 114 is executed.
Proceed to.

On the other hand, if a negative determination is made in step 111 because downshifting is not requested, it is determined whether the hydraulic pressure maximum flag F8 is ON (step 113). As described with reference to FIG. 5, the flag F8 is a flag which is controlled to be ON when it is determined that the engine speed NE is synchronized with the motor speed NM. Therefore, if a negative decision is made in step 113,
Since the engine speed NE is not synchronized with the motor speed NM, in this case, the control relating to the processing of the engine torque is not performed and the process returns. On the other hand, if an affirmative decision is made in step 113, the engine speed N
Since E has been synchronized with the motor speed NM, the routine proceeds to step 114 in this case.

In step 114, fuel injection in the engine 1 is started. That is, when a downshift is required, fuel injection is started when the engine speed NE reaches a predetermined reference speed N4 which is about the idle speed. Further, in the normal case where the downshift is not required, the fuel injection is started by the judgment that the engine speed NE is synchronized with the motor speed NM. If the engine is not equipped with a fuel injection device, fuel supply is started.

Next, the motor torque command value is subtracted from the drive request torque to obtain the engine torque command value (step 115). The drive request torque is a torque required for traveling and is obtained based on the amount of depression of the accelerator pedal. The motor torque command value is
It is the motor torque command value obtained in steps 065 and 066 or the motor torque command value that is swept down in step 063.

The timing of the above-mentioned fuel injection is shown in FIG. 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, at the normal time when the downshift is not required, as shown by the thin solid line in FIG. 8, the fuel supply is started at time t4 when the hydraulic pressure maximum flag F8 is controlled to be ON.

Further, changes in the engine torque command value when the above engine torque processing is performed are shown in FIGS. 7, 14 and 15. The engine torque command value is controlled so that the sum of the engine torque command value and 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 that period, the motor torque command value is maintained at the immediately preceding value, and therefore, the engine torque command value is also maintained during the same period as before.

After that, since the motor torque command value is swept down, the engine torque command value is increased according to the decrease amount of the motor torque command value. As a result, the drive torque is finally satisfied by the engine torque, and the motor torque command value becomes zero at that 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 keeping the driving torque 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 control. This is because there is a demand for increasing the driving force by downshifting. However, since the change in the driving force due to the downshift causes a shock, the downshift is controlled as follows when the engine 1 is rotated by the motor torque.

FIG. 17 shows a subroutine of the downshift start permission processing shown in FIG. 2. First, it is judged whether or not the power-on downshift flag F5 is ON (step 121). This determination step is the same as steps 021, 030 and 111 described above. This step 1
If the determination is negative in 21, the process returns without performing any control, and on the contrary, if the determination is positive,
It is determined whether the engine speed NE is larger than a preset reference value N4 (step 122). This reference value N4 is the same as the reference value that determines the fuel injection timing when there is a downshift request, and therefore, this step 122 basically determines whether or not the engine 1 has been substantially started. . Since the reference value N4 is different in control response between the engine 1 and the transmission 13,
It does not necessarily have to be the same, and may be different as necessary.

When a negative determination is made in step 122, the process returns without performing any particular control. On the other hand, if the affirmative decision is made in step 122, 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 while a load for rotating the engine 1 is applied to the motor / generator 3, thereby preventing a shock. Further, when the input torque to the transmission 13 is controlled at the time of gear shifting, the engine 1 is already started and outputs the torque, so that the control of the input torque becomes easy, and in this respect also, the shock due to the gear shifting can be prevented.

By the way, in the above-described example, when the assist torque is added to the motor torque, the assist torque is controlled to be 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 the assist torque is added to the motor torque, it is preferable to increase the rate of increase in the assist torque within a range that does not worsen the shock. An example will be described below.

FIG. 18 shows step 086 of the assist torque processing subroutine shown in FIG.
It is a routine replaced with 86-1. That is, the control executed in this step 086-1 is a control in which the torque of 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 obtained as the sum of the motoring torque and the inertia torque is multiplied by the skip-up rate to obtain the assist torque amount to be increased first. This skip-up rate is a value set in advance so that the amount of torque increase is such that a shock does not occur. The skip-up rate may be a fixed value, or may be a value (that is, a variable) defined in a map format using the vehicle speed as a parameter.

The assist torque is gradually increased with the motor torque command value thus skipped up as the starting point. 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 To qualitatively explain this, control is performed to repeatedly increase the remaining amount of the assist torque after skip-up by a value divided by the assist counter upper limit value.

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

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

When increasing 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
The synchronization with M is judged by the state in which the difference between the rotational speeds NE and NM is kept below a predetermined value for a certain period of time. Therefore, even if the engine speed NE temporarily exceeds the motor speed NM, the synchronization is not judged immediately. Therefore, if the motor torque added with the assist torque for rotating the engine 1 is continuously output, the motor torque becomes relatively excessive, which may cause a shock. The control shown in FIG. 19 is control for avoiding such an inconvenience.

The routine shown in FIG. 19 is a motor torque command calculation processing subroutine included in the motor torque processing of step 005 shown in FIG. First,
It is determined whether the engine speed NE is higher than the motor speed NM (step 141). As previously mentioned,
Since the assist torque is added in order to increase the engine speed NE to the motor speed NM, it is not necessary to further increase the engine speed 1 once the engine speed NE reaches the motor speed NM. Therefore, if an affirmative decision is made in step 141, the motor torque command value is set to a value corresponding to the drive request torque (step 142). On the contrary, if the engine speed NE is less than or equal to 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
In the range where the motor speed exceeds the motor 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, the motor torque obtained by adding the assist torque to the drive torque is output. as a result,
Since the assist torque is not output in the state where the engine speed NE exceeds the motor speed NM, it is possible to prevent the driving force from temporarily becoming excessive and the shock from occurring.

On the other hand, as shown in FIG. 20B, when the assist torque is continuously output regardless of the engine speed NE, the engine is driven when the engine speed NE exceeds the motor speed NM. Excess torque may result in shock.

When the engine rotational speed NE falls below the motor rotational speed NM and the assist torque is added again after the engine rotational speed NE exceeds the motor rotational speed NM, the assist torque machining process shown in FIG. It is preferable to do so. When such torque processing is performed, the motor torque gradually increases as indicated by the thick solid line in FIG. 20A, and thus shock due to a sudden change in 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. Uses the motor torque guard value as the motor torque command value. Even in that case, if the motor torque is maintained at the upper limit value, 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 driving torque for traveling, so that the driving torque increases. It may cause a shock.

FIG. 21 is a flow chart 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 the engine speed NE exceeds the motor speed NM (step 151). When the affirmative judgment is made in this step 151, it is judged whether or not 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 determination in step 152 is negative because the motor torque command value does not exceed the motor torque guard value, the motor torque command value corresponding to the drive request torque is output (step 153). That is, the state of the vehicle when the determination in step 152 is negative is that the torque that can be output by the motor / generator 3 still has a margin, and the engine speed NE is equal to the motor speed N.
Since it exceeds M, the motor torque command value is set to the command value corresponding to the drive request torque. this is,
The control is similar to that of step 142 of FIG. 19 described above.

On the contrary, when the affirmative judgment is made in step 152 because the motor torque guard flag F9 is ON, 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). 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 engine speed NE does not exceed the motor speed NM and a negative determination is made in step 151, 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 is step 143 in FIG.
The control is similar to.

FIG. 22 shows changes in the motor torque when the control of step 154 is executed and when it is not executed. FIG. 22A shows 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 limit value of the motor torque. Therefore, of the torque output by the motor / generator 3, the engine 1
The torque that was used to rotate the motor is subtracted from the motor torque by making it unnecessary, so the drive torque does not increase relatively, and therefore the drive torque temporarily increases. It is possible to prevent a shock caused by. On the other hand, step 1
When the control of 54 is not executed, as shown in FIG. 22 (B), the driving torque relatively increases in the state where the engine speed NE exceeds the motor speed NM, and this causes a shock. It may be done.

Correspondences between the specific examples described above and the configurations of the claims will be collectively described. Engine 1 described above corresponds to the internal combustion engine in the present invention, also corresponds to the motor generator 3 is the electric motor, further input clutch 5 corresponds to the coupling mechanism of the present invention, motors generator 3
The output shaft 4, the automatic transmission 1 3 that is you and connected thereto,
The output shaft 16 of that is equivalent 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, and FIG.
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 step 151 of FIG. 21 corresponds to the synchronization detecting means, and “any one of the means”.
The functionality of step 154 of step 142 and 21 in FIG. 19 is a phase equivalent, step 004 of FIG. 2, a 3
The process shown in FIG. 5 is the transmission of the connecting mechanism of claim 3.
It corresponds to the means "to control the torque capacity.

In the specific example described above, the hybrid vehicle having a structure in which the output shaft of the motor / generator is connected to the output shaft of the engine through the input clutch is used.
The present invention is not limited to the above example, and can be applied to a hybrid vehicle having a configuration in which an internal combustion engine is connected to a power transmission mechanism or an electric motor via a gear mechanism,
The point is that the drive device may be a so-called parallel hybrid type drive device. Therefore, in the case of determining the operating states of the internal combustion engine and the electric motor, in the above example, the respective rotation speeds were directly compared, but a gear mechanism is interposed between the power transmission device and the electric motor or the internal combustion engine. If so, one of the rotation speeds may be compared with a predetermined value based on the other rotation speed to determine the operating states of the electric motor and the internal combustion engine. In the first aspect, the "reference value determined based on the rotation speed of the electric motor" 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 can be maintained in the traveling state. Since the required torque is set to a torque that is determined by adding a torque determined based on the target rotation speed of the internal combustion engine, a decrease in driving force for traveling is prevented, and a shock associated with starting the internal combustion engine can be avoided. it can.

According to the invention of claim 2, according to claim 1,
Besides obtained by the invention and similar effects, when the rotation speed to start the internal combustion engine has reached a rotational speed of the electric motor, since the running until then can be maintained by the output of the internal combustion engine, the electric motor By reducing the output torque, it is possible to prevent the driving force of the hybrid vehicle as a whole from becoming excessive, to prevent shocks, and also to reduce the driving force of the hybrid vehicle as a whole before and after the start of the internal combustion engine. Becomes constant, so that it is possible to prevent a sudden change in driving force and a shock caused thereby . further
According to the invention of claim 3, the same as the invention of claim 1 or 2.
Can be obtained.

[Brief description of 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 flow chart showing an overall control routine for starting an internal combustion engine while traveling with the output of an electric motor.

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

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

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

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

FIG. 7 is a time chart showing changes in hydraulic pressure, rotation speed, and flags 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 assist torque calculation processing.

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

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

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

FIG. 14 is a time chart showing changes in the motor torque command value when control is performed to increase the assist torque 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 the assist torque is added to the 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 showing an assist torque processing subroutine.

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

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

FIG. 21 is a flowchart showing 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 the motor torque command value when the process 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.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F02D 29/02 321 F02D 29/02 321B F02N 11/00 F02N 11/00 F 11/04 11/04 D 11/08 11/08 GV (56) Reference JP-A-9-109694 (JP, A) JP-A-8-232817 (JP, A) JP-A-6-17727 (JP, A) JP-A-11-164408 (JP, A) ) JP-A-9-117012 (JP, A) JP-A-10-331749 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60L 11/14 ZHV B60K 6/04 F02D 29 / 02 F02N 11/00 F02N 11/04 F02N 11/08

Claims (3)

(57) [Claims] 1. When an output of an electric motor is transmitted to a power transmission system for traveling and the vehicle is traveling, an internal combustion engine is connected to the power transmission system so that the output torque of the electric motor causes the front
In the drive control apparatus for a hybrid vehicle to start the serial in combustion engine, and start request determining means for determining a request for starting of the internal combustion engine, it has been requested to start the internal combustion engine is determined by the start request determining means The output torque of the electric motor is determined based on the target rotational speed of the internal combustion engine.
Mari, and said motor <br/> requires an internal combustion engine to rotate Taringutoru click, also properly corresponds to the torque obtained by adding the inertia torque corresponding to the rotational speed change rate of the internal combustion engine to the motoring torque A drive control device for a hybrid vehicle, comprising: an assist amount setting means for increasing only the torque. Wherein before SL after the start of the starting control of the internal combustion engine by connecting the internal combustion engine to the driveline, reference value determined on the basis of the rotational speed of the internal combustion engine the rotational speed of the rotational speed or the electric motor of the electric motor In the case where it is detected by the synchronization detection means that the number of revolutions of the internal combustion engine becomes equal to or greater than a reference value determined based on the number of revolutions of the electric motor or the number of revolutions of the electric motor. A means for reducing the output torque of the electric motor increased for starting the internal combustion engine, and a means for reducing the output torque of the electric motor even when the output torque of the electric motor is not increased when starting the internal combustion engine, as it claimed that in claim 1 you wherein are provided at least one of the means
Hybrid vehicle drive control device. 3. Based on the judgment result of said start request judging means
The output shaft of the internal combustion engine and the output shaft of the electric motor.
Controlling the transmission torque capacity of the coupling mechanism that selectively couples
The method of claim 1, further comprising means.
Is a drive control device for a hybrid vehicle according to 2.