JP2002106406A - Device for controlling starter of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a starter of an engine which can properly control to start the engine, followed by starting of firing, even though in case of starting the engine by mortoring with a motor. SOLUTION: Crank shaft 16 of the engine 2 is connected with a pulley 20, through a magnetic clutch 28. To the pulley 20, driving power supplied from the motor generator 30 through a belt 22 and the pulley 26. To this motor generator 30, an electric power is supplied from a battery 34 after being regulated by an inverter 32. When starting the engine 2, at first rotating speed is given to the engine 2 by the driving power of the motor generator 30. Then in the firing stage, an instructive value of the objective rotating speed for the engine 2 is preset as to the rotating speed for the engine 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine start control device, and more particularly, to a device for controlling the start of an engine by applying a driving force to the engine by an electric motor at the start of the engine and then firing the engine. .

[0002]

2. Description of the Related Art In a so-called hybrid vehicle having an electric motor, which is supplied with electric power from a battery or the like, as a drive source, in addition to the engine, when starting the engine, the engine is motored by the electric motor, and then a mixture of the air-fuel mixture is supplied. Ignition, that is, firing is performed. For example, as described in Japanese Patent Application Laid-Open No. 9-222064, when starting the engine, first, an engine target rotation speed is calculated according to various operating states such as an engine water temperature and an electric load. Next, the engine is first motored by the electric motor, and the opening of the throttle valve is controlled to a value corresponding to the target rotation speed. Then, when the rotation speed of the engine is increased by the motoring, the firing of the engine is started. By controlling the rotation speed of the engine to the target rotation speed according to the operating conditions by the electric motor in this way, fluctuations in the rotation speed due to the start of the engine are suitably suppressed, and stable engine start control can be performed. Become like

[0003]

In the above technique, when the maximum rotation speed of the motor is reduced due to a shortage of the power supply of the battery or the like, the rotation speed of the engine motored by the motor is reduced to the operating state. In some cases, it is necessary to start the firing of the engine without reaching the target rotation speed set in accordance with the above.
However, if there is a large difference between the actual rotation speed of the engine and the target rotation speed at the start of such firing, the actual rotation speed of the engine may increase sharply, causing a shock to occur.

[0004] The present invention has been made in view of the above circumstances, and an object thereof is to appropriately suppress the engine from rising due to the start of firing even when the engine is started by performing motoring with an electric motor. It is an object of the present invention to provide an engine start control device capable of performing the following.

[0005]

The means for achieving the above object and the effects thereof will be described below. The invention according to claim 1 is an apparatus for controlling the start of the engine by starting firing after motoring the engine by an electric motor connected to an output shaft of the engine, wherein the start of the firing is controlled by the motor. The gist of the invention is to provide a starting rotation speed setting means for setting a target rotation speed of the engine based on an actual rotation speed of the engine during the motoring.

According to the above structure, the target rotation speed of the engine at the start of firing is set based on the actual rotation speed of the engine at the time of motoring of the electric motor. The difference between the target engine speed at the time and the target engine speed can be reduced. Therefore, it is possible to prevent the engine from blowing up at the start of firing.

When the target rotational speed at the start of firing is controlled based on the actual rotational speed at the time of motoring, the target of the engine at the time of motoring is controlled. It is desirable to set the rotation speed based on the actual rotation speed of the engine during the motoring.

According to a third aspect of the present invention, in the second aspect, the intake air amount during the motoring is controlled in accordance with the set target rotation speed during the motoring. .

According to the above configuration, even during motoring, the amount of intake air is controlled in accordance with the target rotational speed of the engine, so that a sudden change in the amount of intake air when shifting from motoring to firing is suppressed. As a result, it is possible to suppress instability of the engine rotation speed such as a hunting phenomenon caused by such a sudden change in the amount of intake air.

According to a fourth aspect of the present invention, in the first aspect of the invention, the starting rotation speed setting means sets the target rotation speed at the time of starting the firing or at the time of the motoring. The gist of the present invention is to set the rotation speed equal to the actual rotation speed of the engine during ringing.

According to the above configuration, the target rotation speed is set equal to the actual rotation speed of the engine at the time of motoring by the startup rotation speed setting means. Can be suppressed.

According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the target rotation speed is set in accordance with an operation state of the engine when firing of the engine is started. The gist of the present invention is to provide a gradual change means for gradually changing the speed.

In the above configuration, after the target rotation speed of the engine at the start of firing is set based on the actual rotation speed of the engine during motoring, the target rotation speed is set based on the operating state of the engine. The rotation speed is controlled to change gradually. Therefore, according to the above configuration, it is possible to start the engine in a manner suited to the operating state while suppressing the engine from rising after the start of firing.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, when the engine accessory is operated during idle operation of the engine, only the target intake air amount is changed without changing the target rotation speed of the engine. The apparatus further includes intake air amount correction means for increasing and correcting the intake air amount in accordance with the magnitude of the electric load of the auxiliary device, wherein the intake air amount increase means comprises a target intake air during the operation of the starting rotation speed setting means or the gradual change means. When increasing the amount, the gist is to gradually increase the target intake air amount to an amount corresponding to the magnitude of the electric load of the auxiliary machine.

In the above configuration, when the engine accessory such as an air conditioner or a light is operated, the air amount correcting means reduces only the target intake air amount to the magnitude of the electric load of the auxiliary device without changing the target rotation speed of the engine. Increase accordingly. Therefore, even if the target rotation speed of the engine at the start of firing is set to the actual rotation speed of the engine at the time of motoring, and then gradually increased therefrom, the throttle opening degree according to the target intake air amount remains at the target rotation speed. The control is gradually increased from an opening larger than the opening corresponding to the rotation speed. For this reason, there is a concern that a blow-up may occur with the start of firing.

In this regard, according to the above configuration, such a problem can be suitably avoided by gradually changing the control for increasing the air amount by the air amount correcting means. In addition, even if the same gradual change operation is performed, the gradual change amount may be changed according to the magnitude of the electric load in consideration of the fact that the manner of increasing the engine rotational speed changes depending on the magnitude of the electric load.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an engine start control device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram schematically showing the configuration of an automatic engine control device according to this embodiment. In the present embodiment, the output of the engine 2 shown in FIG. 1 is output from the output shaft 8 after undergoing a predetermined change by the torque converter 4 and the gear transmission unit 6. The gear transmission unit 6 includes a plurality of planetary gear mechanisms,
This is a portion where the input driving force is shifted in five forward steps and one reverse step, and the maintenance and switching of the engagement of the gears of the planetary gear mechanism are performed by the hydraulic control unit 10.

That is, the hydraulic control unit 10 controls the engine 2
At the time of the operation, the engagement control and the switching control of the gears of the planetary gear mechanism are performed using the hydraulic oil pressurized by the oil pump 12. The oil pump 12 is driven by the power of the engine 2 and is provided between the torque converter 4 and the gear transmission 6 as shown in FIG.

On the other hand, during the automatic stop control of the engine 2, the hydraulic control unit 10 uses the hydraulic oil pressurized by the electric oil pump 14 provided near the torque converter 4 to stop the engine 2 when the engine 2 is stopped. In this case, the engagement of the gears of the planetary gear mechanism in the gear transmission unit 6 is controlled so as to correspond to the shift position for starting.

More specifically, the control of the gear transmission unit 6 by the hydraulic control unit 10 is performed by controlling the clutches C0 to C2 and the brake B of the gear transmission unit 6 shown in the skeleton diagram of FIG.
0 to B4 and the one-way clutches F0 to F2 are controlled by controlling the engagement of the hydraulically driven clutches C0 to C2 and the brakes B0 to B4 with hydraulic oil. As described above, by controlling the engagement modes of the clutches C0 to C2 and the brakes B0 to B4 using the hydraulic oil, the engagement control of the gears according to the respective gears shown in FIG. 3 is performed. In particular, during the automatic stop control of the engine 2 described above, the engagement state of the first speed gear shown in FIG. 3 is maintained corresponding to the starting shift position. If the hydraulic pressure of the hydraulic oil is not sufficient at the time of the automatic stop control of the engine 2, the clutch C1 may slip when starting, and therefore the engagement control of the clutch C1 is performed using the hydraulic oil pressurized by the electric oil pump 14. You. Thereby, a smooth start is possible without the clutch C1 slipping at the time of start.

The output of the engine 2 shown in FIG. 1 is output from the electromagnetic clutch 1 connected to the crankshaft 16.
8, and further transmitted to the belt 22 via the pulley 20. Further, a rotational force is applied to the pulleys 24 and 26 by the driving force transmitted to the belt 22. The electromagnetic clutch 18 switches between transmission and non-transmission of the driving force between the crankshaft 16 and the pulley 20.

The rotational force of the pulley 24 is supplied to an air conditioner compressor 28 used for operating the air conditioner. On the other hand, the rotational force of the pulley 26 is supplied to the motor generator 30. This motor generator 3
At 0, power is generated by the rotational force supplied from the pulley 26, and the generated power is supplied to the battery 34 via the inverter 32. Motor generator 30 also has a function as a motor. In this case, the electric power supplied from the battery 34 is
The rotation speed of motor generator 30 is variably controlled by adjusting the amount of power by means of 2.

The engine 2, the hydraulic control unit 10, the electric oil pump 14, the electromagnetic clutch 18, the motor generator 30, the inverter 32, and the electronically controlled throttle valve 2 c provided in the intake passage of the engine 2. The control is performed by an electronic control unit (hereinafter, referred to as ECU) 40. The ECU 40 includes an ignition switch 41, a vehicle speed sensor 42 for detecting a vehicle speed, and an accelerator sensor 4 for detecting an amount of depression of an accelerator pedal.
3. A brake sensor 44 for detecting whether a brake for keeping the vehicle in a stopped state is depressed, a rotation speed sensor 45 for detecting an output rotation speed of the engine 2, a water temperature sensor 46 for detecting a cooling water temperature of the engine 2, and the like. , The amount of power generated by the motor generator 30, the battery voltage, and the like.

Incidentally, during idling operation, E is determined based on the operation result of the engine 2 such as the detection result of the water temperature sensor 46 and the electric load of auxiliary devices such as the air conditioner compressor 24.
The CU 40 calculates a target rotation speed of the engine 2. Then, in order to approximate the actual rotation speed of the engine 2 to the calculated target rotation speed, a command is issued to the throttle opening of the throttle valve 2c and the fuel injection amount injected from an injector in the engine 2. The control result based on this command is reflected on the actual rotation speed detected by the rotation speed sensor 45. Thus, the rotation speed of the engine 2 is feedback-controlled.

Next, the automatic stop control of the engine 2 in the present embodiment will be described. In this embodiment,
(A) The ignition switch 41 is turned on (b) The vehicle speed sensor 42 detects that the vehicle speed is "0" (c) The accelerator sensor 43 detects that the accelerator pedal is not depressed (D) The automatic stop control of the engine 2 is performed when all the conditions such as that the brake sensor 44 confirms that the brake is depressed are satisfied for a predetermined time or more.

When the automatic stop control of the engine 2 is performed,
Fuel injection from an injector provided in the engine 2 is stopped, and ignition control by a spark plug provided in the engine 2 is also stopped. As a result, the engine 2 is stopped. Further, with the stop control of the engine 2, the drive of the electric oil pump 14 is controlled, and the hydraulic oil of the hydraulic control unit 10 is pressurized by the electric oil pump 14. Using the pressurized hydraulic oil, the hydraulic control unit 10 controls the engagement of the gears of the gear transmission unit 6 to a state corresponding to the starting shift. As a result, the vehicle can be started smoothly.

Next, the automatic start control according to this embodiment will be described. In this embodiment, (b) the vehicle speed sensor 42 detects that the vehicle speed is "0". (C) The accelerator sensor 43 detects that the accelerator pedal is not depressed. (D) Brake The automatic start control of the engine 2 is performed on condition that even one of the conditions such as the fact that the brake is depressed by the sensor 44 is not satisfied.

In the automatic start control of the engine 2, a driving force is applied to the crankshaft 16 by using the motor generator 30 described above as a motor. The driving force applied to the crankshaft 16 is transmitted to the engine 2 and the torque converter 4. As described above, at the time of the automatic start control of the engine 2 of the present embodiment, the driving force is applied to the engine 2 by the motor generator 30 without using the starter (not shown).

After the driving force is applied to the crankshaft 16 by the motor generator 30 for a predetermined period, firing is performed in the engine 2. That is, the fuel injection control and the ignition timing control of the engine 2 are started. Thus, in this embodiment,
When the engine 2 is automatically started, the driving force applied to the torque converter 4 is supplied by the motor generator 30 first, and then the switching control is performed so as to be supplied by the engine 2.

However, when the command value of the target rotation speed of the engine 2 is set to the target rotation speed in accordance with the above-described operation state when switching from the motor generator 30 to the engine 2, the actual rotation of the engine 2 during motoring is performed. A large difference may occur between the speed and the target rotation speed command value. At this time, when the throttle opening is controlled to increase so as to approximate the actual rotation speed of the engine 2 to the command value of the target rotation speed, the rotation speed of the engine 2 sharply increases and a shock occurs. It is as follows. Here, since the engagement of the gear corresponding to the starting shift is maintained in the gear transmission unit 6 in order to smoothly start as described above, this shock is likely to be transmitted to the vehicle. ing.

Therefore, in the present embodiment, the command value of the target rotation speed of the engine 2 is supplied to the engine 2 by the motoring while the engine 2 is being motored by the motor generator 30 upon starting. It is set as speed. Then, based on the command value set in this way, the throttle valve 2
The opening of c is controlled. At the time of firing, the command value of the target rotation speed of the engine 2 is set as the actual rotation speed of the engine 2 at the time of motor link. in this way,
By setting the rotation speed of the engine 2 at the time of motoring as the command value of the target rotation speed, the above-described problem associated with firing can be avoided.

In the present embodiment, after firing, control is performed such that the command value of the target rotation speed of the engine 2 is gradually approached to the target rotation speed calculated based on the operating state.

Here, transitions of the rotation speed of the engine 2 and the opening degree of the throttle valve 2c when the engine is started in this embodiment will be described with reference to FIG. As shown in FIG. 4A, when motoring of the engine 2 is performed by the motor generator 30 in accordance with the start of the engine 2, the rotation speed of the engine 2 becomes equal to the rotation speed given by the motor generator 30. Become. During this time, the opening of the throttle valve 2c is controlled to a value at which the same rotational speed can be obtained only by driving the engine. At time t1 when motoring is continued for a predetermined period, the throttle valve 2c and the like are controlled so that the rotation speed of the engine 2 becomes the rotation speed at the time of motoring even if firing is performed. Is performed smoothly.

Then, the time t when the firing is performed
From 1, control is performed to gradually approach the target rotation speed of the engine 2 calculated based on the operating state.
After that, at time t2, when the target rotation speed calculated based on the operating state is reached, normal control of the engine 2 is performed.

On the other hand, as shown in FIG.
When the engine 2 is controlled as usual, during motoring, the opening of the throttle valve 2c is fixed at the opening when the engine was stopped last time. Then, at the time t1, when the firing is performed, control is performed so as to approximate the actual rotation speed of the engine 2 to a target rotation speed (see a broken line) of the engine 2 calculated based on the operating state. Here, if there is a large difference between the target rotation speed and the rotation speed during motoring due to a low battery or the like, the throttle valve 2c is controlled to increase. The increased opening of the throttle valve 2c is larger than the opening corresponding to the target rotation speed, so that the actual rotation speed of the engine 2 rapidly rises above the target rotation speed, and the vehicle Shock will occur.

Here, the procedure of the start control of the engine 2 according to the present embodiment will be described with reference to FIG. FIG.
5 is a flowchart showing a start control procedure of the engine 2 according to the present embodiment. This routine is activated by interruption every predetermined period.

In this series of processing, first, at step 100, it is determined whether or not the motoring is being performed in accordance with the start of the engine 2. Then, when it is determined that the motoring is being performed, the process proceeds to step 110, and the variable x for temporarily storing the command value of the target rotation speed of the engine 2 is assigned to the current value assigned to the engine 2 by the motoring. The rotation speed of the engine 2 is set.

Then, after executing the processing in step 110, in step 120, the command value of the target rotation speed is set in the variable x, and this processing is temporarily ended. Then, the opening of the throttle valve 2c is controlled based on the command value of the target rotation speed.

On the other hand, if it is determined in step 100 that motoring is not being performed, in other words, if it is determined that firing has been started, the process proceeds to step 130. Then, in step 130, it is determined whether or not the variable x is smaller than the target rotation speed calculated according to the above-described operating state. When it is determined that the variable x is smaller than the target rotation speed,
In step 140, the variable x is increased by a predetermined gradual change amount, and the process proceeds to step 120.

The processing of steps 130 and 140 is as follows:
This is for gradually bringing the command value of the target rotation speed of the engine 2 closer to the target rotation speed calculated according to the operating state.

On the other hand, if it is determined in step 130 that the variable x is equal to or higher than the target rotational speed, the routine proceeds to step 150, where the variable x is set to the target rotational speed, and the routine proceeds to step 120.

After performing the processing of step 150, this routine is completed until the next start of the engine 2. According to the embodiment described above, the following effects can be obtained.

(1) During motoring, the command value of the target rotation speed of the engine 2 is set to the rotation speed given to the engine 2 by motoring, and the opening of the throttle valve 2c corresponds to the command value. By controlling the value to the set value, it is possible to smoothly transfer the driving force from motor generator 30 to engine 2 during firing.

(2) After the firing of the engine 2, the command value of the target rotation speed of the engine 2 is gradually increased to the target rotation speed calculated based on the operating state, thereby starting the engine 2. Can be performed smoothly.

The above embodiment may be modified and implemented as follows. The conditions for performing the automatic stop control and the automatic start control of the engine 2 described in the above embodiment may be appropriately changed and performed.

In the above embodiment, the command value of the target rotation speed of the engine 2 at the time of motoring and at the start of firing is set to the rotation speed given to the engine 2 by motoring. It is not necessary to make them coincide with each other, and the command value of the target rotation speed of the engine 2 may be set based on the rotation speed of the engine 2 given by the motoring.

Furthermore, it is not always necessary to set the command value of the target rotation speed of the engine 2 during motoring. In this case, control during motoring of the throttle valve 2c is not performed.

In the above embodiment, after starting the firing, the control of the throttle valve 2c is performed based on the command value of the target rotation speed of the engine 2. During the operation of the electric load of the machine, control may be performed to increase only the target air amount without changing the target rotation speed. In this case, it is desirable to gradually change the increase control amount of the air amount, such as controlling the air amount including the increase amount to be an air amount according to the command value of the target rotation speed.

In this embodiment, when the engine is automatically started, the driving force of the motor generator 30 is supplied to the torque converter 4 and the engine 2 is fired after reaching the motoring rotation speed. It is not limited to this. In short, the present invention can be applied to any engine automatic starter that includes an electric motor connected to the output shaft of the engine and can switch between the driving force by the electric motor and the driving force by the engine.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment of an engine start control device according to the present invention.

FIG. 2 is a skeleton diagram showing a configuration of a gear in the gear transmission unit of the embodiment.

FIG. 3 is a diagram showing an engagement state of gears in the gear transmission unit of the embodiment.

FIG. 4 is a time chart showing changes in the rotation speed and the throttle valve opening when the engine is started according to the embodiment.

FIG. 5 is a flowchart showing a start control procedure of the engine of the embodiment.

[Explanation of symbols]

2 ... Engine, 2c ... Throttle valve, 4 ... Torque converter, 6 ... Gear transmission unit, 8 ... Output shaft, 10 ... Hydraulic control unit, 12 ... Oil pump, 14 ... Electric oil pump, 16 ... Crank shaft, 18 ... Electromagnetic clutch, 20, 24, 26 ... pulley, 22 ... belt, 28 ...
Air conditioner compressor, 30 ... motor generator,
32 inverter, 34 battery, 40 electronic control device, 41 ignition switch, 42 vehicle speed sensor, 43 accelerator sensor, 44 brake sensor, 4
5: rotational speed sensor, 46: water temperature sensor, 2c: throttle valve.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G084 BA05 BA28 CA01 DA08 DA09 EA07 EC01 EC03 FA33 3G301 JA04 KA01 LA01 NE03 NE23 PE01Z

Claims (6)

[Claims] An apparatus for controlling the start of an engine by starting firing after motoring the engine by an electric motor connected to an output shaft of the engine, wherein the target rotation of the engine at the time of starting the firing. An engine start control device comprising: a start rotation speed setting means for setting a speed based on an actual rotation speed of the engine during the motoring. 2. The starting of the engine according to claim 1, wherein said starting rotation speed setting means sets a target rotation speed of said engine during said motoring based on an actual rotation speed of said engine during said motoring. Control device. 3. The engine start control device according to claim 2, wherein the amount of intake air during the motoring is controlled in accordance with the set target rotation speed during the motoring. Control device. 4. The starting rotational speed setting means for setting the target rotational speed at the start of firing or at the time of motoring to be equal to the actual rotational speed of the engine at the time of motoring. An engine start control device according to any one of the claims. 5. The engine start control device according to claim 1, wherein the target rotation speed is set to a rotation speed set in accordance with an operation state of the engine when firing of the engine is started. An engine start control device comprising a gradually changing means for gradually changing. 6. The engine start control device according to claim 5, wherein when the engine accessory is operated during idling operation of the engine, only the target intake air amount is changed without changing the target rotational speed of the engine. Further comprising intake air amount correcting means for increasing the amount of intake air in accordance with the magnitude of the electric load, wherein the intake air amount increasing means comprises a target intake air amount during the operation of the starting rotation speed setting means or the gradual change means. An engine start control device characterized in that when increasing the amount, the target intake air amount is gradually increased to an amount corresponding to the magnitude of the electric load of the auxiliary machine.