JP6870318B2 - Hybrid vehicle drive controller - Google Patents

Description

The present invention relates to a drive control device for a hybrid vehicle.

In the conventional hybrid vehicle, the technique described in Patent Document 1 is known. Further, in the hybrid vehicle described in Patent Document 1, the engine and the motor are connected via a belt. In the technique described in Patent Document 1, fuel injection is performed when the engine is started by a motor, so that fuel efficiency and exhaust performance are improved without giving a feeling of sluggishness when the vehicle starts. ..

Japanese Unexamined Patent Publication No. 2004-251221

By the way, in a configuration in which a motor and an engine are connected via a belt as in the hybrid vehicle described in Patent Document 1, when the engine is started from a state in which the vehicle is driven by the driving force of only the motor, the engine is used. May make a mistake in determining whether or not the vehicle has completely exploded.

Specifically, in the hybrid vehicle described in Patent Document 1, when it is determined that the engine has completely exploded because the engine speed exceeds a predetermined threshold, the engine is rotated by the motor during EV driving. The engine speed may exceed a predetermined threshold.

Therefore, in the hybrid vehicle described in Patent Document 1, it may be erroneously determined that the engine has completely exploded, and an engine stall occurs when the motor is stopped and the vehicle is driven by the driving force of the engine. There was a problem of doing it.

Therefore, an object of the present invention is to provide a drive control device for a hybrid vehicle that can prevent an engine stall when the engine is started from a state in which the vehicle is running by the drive torque of the motor.

In order to solve the above problems, the present invention includes an internal combustion engine, a motor, and a control unit that controls the internal combustion engine and the motor, and travels with the drive torque of at least one of the internal combustion engine and the motor. A vehicle drive control device, the output shaft of the internal combustion engine is connected to the drive shaft of the vehicle, the motor is connected to the output shaft of the internal combustion engine via a power transmission mechanism, and the control unit is the motor. When the fuel injection to the internal combustion engine is started from the state in which the vehicle is running by the driving torque of the internal combustion engine to start the internal combustion engine, the internal combustion engine is in a state where the motor is rotating with the internal combustion engine. It is determined whether or not the internal combustion engine has pre-exploded based on at least one of the engine rotation speed and the number of ignitions, and if it is determined that the internal combustion engine has pre-exploded, the drive torque of the motor is determined. When it is determined whether or not the internal combustion engine has completely exploded based on at least one of the rotation speed and the number of ignitions of the internal combustion engine in the stopped state, and it is determined that the internal combustion engine has not completely exploded. It is characterized in that a driving torque is generated in the motor to completely explode the internal combustion engine.

As described above, according to the present invention, engine stall can be prevented when the engine is started from a state in which the vehicle is running by the driving torque of the motor.

FIG. 1 is a configuration diagram showing a drive control device for a hybrid vehicle according to an embodiment of the present invention. FIG. 1 is a block diagram showing a drive control device for a hybrid vehicle according to an embodiment of the present invention. FIG. 3 is a flowchart showing a processing procedure of the drive control device of the hybrid vehicle according to the embodiment of the present invention. FIG. 4 is a timing chart showing a processing procedure of a drive control device for a hybrid vehicle according to an embodiment of the present invention.

The drive control device for a hybrid vehicle according to an embodiment of the present invention includes an internal combustion engine, a motor, and a control unit that controls the internal combustion engine and the motor, and uses the drive torque of at least one of the internal combustion engine and the motor. A drive control device for a traveling hybrid vehicle, the output shaft of the internal combustion engine is connected to the drive shaft of the vehicle, the motor is connected to the output shaft of the internal combustion engine via a power transmission mechanism, and the control unit drives the motor. When starting fuel injection to the internal combustion engine from the state where the vehicle is running by torque and starting the internal combustion engine, it is determined whether or not the internal combustion engine has completely exploded with the drive torque of the motor stopped. However, when it is determined that the internal combustion engine has not completely exploded, a driving torque is generated in the motor to completely explode the internal combustion engine. Thereby, the drive control device for the hybrid vehicle according to the embodiment of the present invention can prevent the engine stall when the engine is started from the state where the vehicle is running by the drive torque of the motor.

Hereinafter, the drive control device for the hybrid vehicle according to the embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, a vehicle 1 equipped with a drive control device for a hybrid vehicle according to an embodiment of the present invention includes an engine 2, a power supply system 3, and an ECU (Electronic Control Unit) 4 as a control unit. Has been done.

The engine 2 includes a piston, a cylinder, a connecting rod, etc. (not shown), and is a four-cycle engine that performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while the piston makes two reciprocations in the cylinder. It is composed of.

The engine 2 is provided with a fuel injection device 55 for injecting fuel and an ignition device 56 for igniting a mixture of fuel and air. The fuel injection device 55 and the ignition device 56 are electrically connected to the ECU 4 and are controlled by the ECU 4.

The piston housed in the cylinder is connected to the crankshaft 2a as an output shaft via a connecting rod. The connecting rod is adapted to convert the reciprocating motion of the piston into the rotational motion of the crankshaft 2a.

A transmission 23 is connected to the engine 2. The transmission 23 shifts the rotation of the crankshaft 2a of the engine 2 at a predetermined gear ratio and transmits it to the drive shaft 25 as a drive shaft via a differential gear (not shown) or the like so as to rotate the left and right wheels 26. It has become.

The transmission 23 is composed of, for example, a CVT (Continuously Variable Transmission), and the CVT automatically shifts continuously steplessly by a set of pulleys around which a metal belt (not shown) is wound. In FIG. 1, only the two wheels 26 are shown, and the remaining two wheels are not shown.

The power supply system 3 includes a main battery 31, a sub-battery 32, a motor 33, and a switch (SW) circuit 34.

The main battery 31 is composed of, for example, a lead storage battery. The main battery 31 is electrically connected to the motor 33 via a switch circuit 34. The main battery 31 is provided with a battery status sensor 31a. The battery status sensor 31a detects the charge / discharge current, voltage, and battery temperature of the battery 31. The battery status sensor 31a is connected to the ECU 4. The ECU 4 can detect the charging state of the main battery 31 by the output of the battery status sensor 31a.

The sub-battery 32 is composed of, for example, a lithium ion storage battery. The sub-battery 32 is electrically connected to the motor 33 via a switch circuit 34. The sub-battery 32 is provided with a battery status sensor 32a. The battery status sensor 32a is connected to the ECU 4. The ECU 4 can detect the charging state of the sub-battery 32 by the output of the battery state sensor 32a.

The switch circuit 34 selects and connects at least one of the main battery 31 and the sub battery 32 as a power source for supplying electric power to the motor 33. The switch circuit 34 connects the motor 33 to the main battery 31 and the sub battery 32 under the control of the ECU 4.

The motor 33 is a motor having a function as an alternator that generates electricity by driving the engine 2 in addition to the function as a starter for starting the engine 2. The motor 33 is driven by electric power supplied from at least one of the main battery 31 and the sub battery 32. The motor 33 controls the output torque according to the torque command signal output by the ECU 4.

The motor 33 is connected to the crankshaft 2a of the engine 2 via a power transmission mechanism 29 so as to be able to transmit power to each other. The power transmission mechanism 29 is wound around a motor pulley 33b connected to a rotor shaft 33a of a motor 33, a crankshaft pulley 2b connected to a crankshaft 2a of an engine 2, a crankshaft pulley 2b, and a motor pulley 33b. It consists of a hung belt 28. The power transmission mechanism 29 decelerates the rotation of the motor 33 and transmits it to the engine 2.

The ECU 4 is composed of a computer unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an input port, and an output port.

The ROM of the ECU 4 stores various control constants, various maps, and the like, as well as a program for causing the computer unit to function as the ECU 4. That is, when the CPU executes the program stored in the ROM, the computer unit functions as the ECU 4.

In addition to the above-mentioned battery status sensor 31a and battery status sensor 32a, various sensors such as an engine speed sensor 51, a vehicle speed sensor 52, an accelerator opening sensor 53, and a brake switch 54 are connected to the input port of the ECU 4. ..

The engine speed sensor 51 detects the engine speed of the engine 2. The vehicle speed sensor 52 detects the speed of the vehicle 1 from the rotation speed of the wheels 26 and the like.

The accelerator opening sensor 53 detects an accelerator opening, which is an opening of an accelerator pedal (not shown) operated by the driver, for example, when an acceleration is requested.

The brake switch 54 detects whether or not a brake pedal (not shown) is depressed. The brake switch 54 outputs an on signal when the brake pedal is depressed, and outputs an off signal when the brake pedal is not depressed.

On the other hand, various control objects such as the engine 2, the motor 33, and the switch circuit 34 are connected to the output port of the ECU 4.

As shown in FIG. 2, the ECU 4 fuels the engine 2 based on the detection signals of the battery status sensor 31a, the battery status sensor 32a, the engine rotation speed sensor 51, the vehicle speed sensor 52, the accelerator opening sensor 53, and the brake switch 54. It controls the injection device 55, the ignition device 56, and the motor 33. Specifically, the ECU 4 controls the fuel injection state of the fuel injection device 55, the ignition state of the ignition device 56, and the motor torque of the motor 33.

Depending on the driver's request or the vehicle condition, the ECU 4 runs the engine running with the driving torque (engine torque) of the engine 2, EV running running with the driving force of the motor 33 (motor torque), or the engine 2 and the motor 33. HEV running, which runs with both driving torques of the above, is carried out. Therefore, the vehicle 1 constitutes a hybrid vehicle that travels with the driving torque of at least one of the engine 2 and the motor 33.

Here, during EV traveling, the ECU 4 generates a drive torque in the motor 33 in a state where the fuel injection of the engine 2 is stopped and the operation of the engine 2 is stopped. During EV travel, the engine 2 is rotated by the belt 28 along with the motor 33.

The ECU 4 controls the switch circuit 34 so that the sub-battery 32 is connected to the motor 33 and the main battery 31 is connected to another electric load (not shown) during EV traveling. Here, the electric load includes an air conditioner, a meter, and lights (not shown).

The ECU 4 controls the switch circuit 34 so that the sub-battery 32 is connected to the motor 33 and the electric load and the main battery 31 is not connected to either the motor 33 or the electric load during HEV travel.

The ECU 4 starts the engine 2 when a predetermined engine starting condition is satisfied during EV traveling. The engine starting condition includes, for example, that the amount of depression of the accelerator pedal is equal to or more than a predetermined amount, and that the SOC (State Of Charge) of the main battery 31 and the sub battery 32 is less than a predetermined value.

When the engine start condition is satisfied during EV traveling, the ECU 4 starts fuel injection by the fuel injection device 55 to start the engine 2, and determines whether or not the engine 2 has completely exploded.

Here, in the vehicle 1 of the present embodiment, since the engine 2 rotates with the motor 33 during EV traveling, the engine speed exceeds the threshold value for the complete explosion determination due to the rotation with the motor 33. In that case, there is a possibility that the engine 2 is erroneously determined to have been completely detonated even though it has not been completely detonated. Therefore, when the engine 2 is started from the EV running and the transition to the HEV running, the engine stall may occur due to the stop of the motor 33.

Therefore, in this embodiment, the ECU 4 determines whether or not the engine 2 has completely exploded while the drive torque of the motor 33 is stopped. Further, when the ECU 4 determines that the engine 2 has not completely exploded, the ECU 4 generates a drive torque in the motor 33 to completely explode the engine 2.

Here, the ECU 4 determines that the engine 2 has completely exploded when the number of ignitions of the engine 2 reaches the predetermined number of times in a state where the rotation speed of the engine 2 exceeds a predetermined value. The ECU 4 may determine that the engine 2 has completely exploded when the rotation speed of the engine 2 exceeds a predetermined value.

When the ECU 4 generates a drive torque in the motor 33 to completely explode the engine 2, the number of ignitions of the engine 2 reaches a predetermined number while the rotation speed of the engine 2 continues to exceed a predetermined value. , It is determined that the engine 2 has completely exploded.

The engine starting process by the drive control device of the hybrid vehicle according to the present embodiment configured as described above will be described with reference to FIG. The engine starting process described below is performed during EV driving. Further, this engine starting process is repeated at preset time intervals.

In step S1, the ECU 4 repeatedly determines whether or not the engine start condition is satisfied. When the engine start condition is satisfied, in step S2, the ECU 4 starts fuel injection to the engine 2.

Next, in step S3, the ECU 4 repeatedly determines whether or not the engine speed exceeds a predetermined value. When the engine speed exceeds the predetermined value, in step S4, the ECU 4 determines whether or not the number of ignitions of the engine 2 exceeds the predetermined number. The number of ignitions in step S4 is the number of ignitions since the start of fuel injection into the engine in step 2.

As described above, in steps S3 and S4, the ECU 4 performs the complete explosion determination in the state where the engine 2 is being rotated by the motor 33 as the pre-complete explosion determination. Further, in steps S3 and S4, the ECU 4 determines that the engine 2 has completely exploded when the integrated value of the number of ignitions in a state where the engine speed exceeds the predetermined value at the time of ignition reaches the predetermined number of times. It has become.

When the number of ignitions exceeds the predetermined number in step S4, it is assumed that the pre-complete explosion determination is established, and in step S5, the ECU 4 stops driving the motor 33.

Next, in step S6, the ECU 4 determines whether or not the engine speed exceeds a predetermined value. When the engine speed exceeds the predetermined value, in step S7, the ECU 4 determines whether or not the number of ignitions exceeds the predetermined number. The number of ignitions in step S7 is the number of ignitions after it is determined in step S4 that the number of ignitions of the engine 2 exceeds a predetermined number of times.

As described above, in steps S6 and S7, the ECU 4 performs the complete explosion determination with the drive torque of the motor 33 stopped.

When the number of ignitions exceeds the predetermined number in step S7, it is assumed that the complete explosion determination is established, and the ECU 4 ends the current operation.

On the other hand, if the engine speed is equal to or less than a predetermined value in step S6, the ECU 4 starts driving the motor 33 in step S8. Here, the ECU 4 controls the motor 33 so that the engine speed becomes smaller than the predetermined value of the complete explosion determination.

Next, in step S9, the ECU 4 determines whether or not the engine speed exceeds a predetermined value. When the engine speed exceeds the predetermined value, in step S10, the ECU 4 determines whether or not the number of ignitions exceeds the predetermined number. The number of ignitions in step S10 is the number of ignitions after it is determined in step S9 that the engine speed exceeds a predetermined value.

As described above, in steps S9 and S10, the ECU performs the complete explosion determination in a state where the engine 2 is assisted by the driving torque of the motor 33. Further, in steps S9 and S10, the ECU 4 resets the number of ignitions to 0 when the rotation speed of the engine 2 drops below a predetermined value. Therefore, the ECU 4 determines that the engine 2 has completely exploded when the number of ignitions of the engine 2 reaches the predetermined number of times while the rotation speed of the engine 2 continues to exceed the predetermined value.

When the number of ignitions exceeds the predetermined number in step S10, it is assumed that the complete explosion determination is established in step S11, the drive of the motor 33 is stopped, and the current operation is terminated.

FIG. 4 is a timing chart for explaining the transition of the vehicle state and the like when the engine 2 is started by the engine start process of the ECU 4.

In FIG. 4, the vertical axis shows the engine speed, the motor torque, the ignition drive state, and the fuel injection state, and the horizontal axis shows the time.

At time t0, the fuel injection is off and the ignition drive state is on, and the vehicle 1 is traveling by the drive torque of the motor 33. In this state, the engine 2 is driven by the motor 33, and the engine speed changes above a predetermined value.

After that, at time t1, the start of the engine 2 is started when the engine start condition is satisfied. At this time t1, the fuel injection is turned on, the ignition drive state is turned on, and the engine speed is increased by the generation of the engine torque of the engine 2.

After that, at time t2, the pre-complete explosion determination is established (YES in step S4 of FIG. 3), so that the drive of the motor 33 is stopped and the motor torque drops.

After that, at time t3, the engine speed became equal to or less than a predetermined value (NO in step S6 of FIG. 3), so that the motor 33 was started to be driven at time t4, and the engine speed was assisted by the motor torque. To rise.

After that, at time t5, the engine speed exceeds a predetermined value (YES in step S9 in FIG. 3), and at time t6, the number of ignitions exceeds a predetermined number (YES in step S10). At time t6, the complete explosion determination was established, and it was confirmed that the engine 2 had started reliably, so that the driving of the motor 33 was stopped. After that, the ECU 4 runs the vehicle 1 by HEV running.

As described above, in the present embodiment, the crankshaft 2a of the engine 2 is connected to the drive shaft 25, and the motor 33 is connected to the crankshaft 2a of the engine 2 via the power transmission mechanism 29.

Then, the ECU 4 is in a state where the driving torque of the motor 33 is stopped when the fuel injection to the engine 2 is started and the engine 2 is started from the state where the vehicle is driven by the driving torque of the motor 33. It is determined whether or not 2 has completely exploded. When the ECU 4 determines that the engine 2 has not completely exploded, the ECU 4 generates a drive torque in the motor 33 to completely explode the engine 2.

As a result, if it is determined that the engine 2 has not completely exploded while the drive torque of the motor 33 is stopped, the drive torque can be generated in the motor 33 and the engine 2 can be completely detonated by assisting the drive torque. it can.

As a result, engine stall can be prevented when the engine 2 is started from a state in which the vehicle is running by the driving torque of the motor 33.

Further, in the present embodiment, the ECU 4 determines that the engine 2 has completely exploded when the rotation speed of the engine 2 exceeds a predetermined value.

As a result, when the rotation speed of the engine 2 exceeds a predetermined value while the drive torque is stopped, it is determined that the engine 2 has completely exploded. Therefore, it is possible to avoid an erroneous determination of the complete explosion, and the engine stalls. Can be prevented.

Further, in the present embodiment, the ECU 4 determines that the engine 2 has completely exploded when the number of ignitions of the engine 2 reaches a predetermined number in a state where the rotation speed of the engine 2 exceeds a predetermined value.

As a result, when the number of revolutions of the engine 2 exceeds the predetermined value and the number of ignitions of the engine 2 reaches the predetermined number with the drive torque stopped, it is determined that the engine 2 has completely exploded. Therefore, it is possible to avoid erroneous judgment of complete explosion and prevent engine stall.

Further, in the present embodiment, when the ECU 4 generates a drive torque in the motor 33 to completely explode the engine 2, the engine 2 is ignited in a state where the rotation speed of the engine 2 continuously exceeds a predetermined value. When the number of times reaches a predetermined number of times, it is determined that the engine 2 has completely exploded.

As a result, when the rotation speed of the engine 2 drops below a predetermined value, the number of ignitions is reset to 0, and the drive torque generated by the motor 33 is continued, so that engine stall can be prevented.

Although the embodiments of the present invention have been disclosed, it is clear that some skilled in the art can make changes without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

1 vehicle (hybrid vehicle)
2 Engine (internal combustion engine)
2a Crankshaft (output shaft)
4 ECU (control unit)
25 drive shaft (drive shaft)
29 Power transmission mechanism 33 Motor

Claims (4)

A drive control device for a hybrid vehicle comprising an internal combustion engine, a motor, and a control unit for controlling the internal combustion engine and the motor, and traveling with the drive torque of at least one of the internal combustion engine and the motor.
The output shaft of the internal combustion engine is connected to the drive shaft of the vehicle, and the motor is connected to the output shaft of the internal combustion engine via a power transmission mechanism.
The control unit
When the fuel injection to the internal combustion engine is started from the state in which the vehicle is running by the driving torque of the motor to start the internal combustion engine,
With the motor rotating the internal combustion engine, it is determined whether or not the internal combustion engine has pre-exploded based on at least one of the rotation speed and the number of ignitions of the internal combustion engine.
When it is determined that the internal combustion engine has pre-exploded, whether the internal combustion engine has completely exploded based on at least one of the rotation speed and the number of ignitions of the internal combustion engine while the drive torque of the motor is stopped. Judge whether or not
A drive control device for a hybrid vehicle, characterized in that, when it is determined that the internal combustion engine has not completely detonated, a drive torque is generated in the motor to completely explode the internal combustion engine. The drive control device for a hybrid vehicle according to claim 1, wherein the control unit determines that the internal combustion engine has completely exploded when the rotation speed of the internal combustion engine exceeds a predetermined value. The control unit is characterized in that it determines that the internal combustion engine has completely exploded when the number of ignitions of the internal combustion engine reaches a predetermined number in a state where the rotation speed of the internal combustion engine exceeds a predetermined value. The drive control device for a hybrid vehicle according to claim 2. The control unit
When the drive torque is generated in the motor to completely explode the internal combustion engine,
A claim characterized in that, when the number of ignitions of the internal combustion engine reaches a predetermined number of times in a state where the rotation speed of the internal combustion engine continuously exceeds a predetermined value, it is determined that the internal combustion engine has completely exploded. Item 3. The drive control device for a hybrid vehicle according to item 3.

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