JP2003083210A - Device for controlling start of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for a controlling start of an engine capable of starting the engine stably without making a diver worry about the delay of the engine starting. SOLUTION: ECU power supply is turned on (point T1). After a starter which is turned on (point T2), the time after the ECU power supply is turned on becomes more than the set time which is decided depending on a first judgment threshold C1. When the time of the starter switch ON becomes more than set time which is decided depending on a second judgment threshold C2 (point T3), a starter relay is turned on and the operation of the starter is begun. Afterward, the starter relay is maintained in turning on even if the starter switch is turned off (point T4) and the operation of the starter is continued. When the engine complete explosion is judged (point T5), the starter relay is turned off and the operation of the starter is stopped. Thereby, because ECU controls the operation of the starter automatically so as to operate the system effectively and start the engine shortest, the driver can start the engine stably without worrying about the delay of the engine starting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting control device for an engine, which enables a stable starting without causing a driver to worry about a delay in starting the engine.

[0002]

2. Description of the Related Art Conventionally, there is a technique of automatically controlling the operation of a starter by an electronic control unit for controlling the engine in order to enable stable starting of the engine. In this automatic starter control, when the driver turns on the power of the electronic control unit by turning on the ignition switch,
The operation of the starter switch from OFF to ON by the driver is detected by the electronic control unit, and the starter is automatically operated with a predetermined delay time to start the engine.

The delay time until the starter operation is
When the engine is started, the preparation time for the system to function effectively, for example, the time until the air-fuel ratio sensor such as the O2 sensor arranged in the exhaust system is activated by the built-in heater, the fuel injected from the injector is well atomized. Since the engine negative pressure cannot be obtained at the time of starting, the assist air to be supplied is determined by the air filling time for pressurizing and supplying. Further, although the engine can use gasoline and alcohol, as a delay time until the starter operates, as disclosed in Japanese Patent Application Laid-Open No. 5-26087 by the present applicant, the fuel pump is driven before the starter operates. Then, there is time until the alcohol concentration distribution of the fuel is made uniform by the fuel circulation.

[0004]

However, for a driver who has a habit of operating the starter when the electronic control unit is turned on, there is a delay time between the electronic control unit being turned on and the actual starter operation. However, there is a problem that the engine start time is felt long.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an engine start control device that enables a stable start without causing the driver to worry about the delay in engine start. .

[0006]

In order to achieve the above object, the invention according to claim 1 is characterized in that the time after power-on of an electronic control unit for controlling an engine has passed a first set time or more, and a starter is provided. Engine start condition determining means for determining whether or not an engine start condition for keeping the starter switch for operating the engine ON for a second set time or longer is satisfied, and whether or not the engine has completely exploded. When it is determined that the complete explosion determination means for determining and the engine starting condition are satisfied, the starter is operated, and thereafter, the operation of the starter is continued regardless of the on / off state of the starter switch, and the engine complete explosion is determined. And a starter control means for stopping the starter when the determination is made.

According to a second aspect of the invention, in the first aspect of the invention, the starter switch is a push button type switch which is turned on by a pressing operation.

That is, according to the first aspect of the invention, the first time after the power is turned on to the electronic control unit for controlling the engine is first.
When the set time of is exceeded and the time for turning on the starter switch for operating the starter continues for the second set time or more, the starter is operated, and thereafter,
Until the engine is judged to be a complete explosion, the starter operation continues regardless of the on / off state of the starter switch, and when it is judged to be an engine complete explosion, the starter is stopped so that the driver only turns on the starter switch once. so,
The engine is automatically started without worrying about the delay in starting the engine, and stable engine starting is possible.

In this case, it is desirable that the starter switch is a push button type switch which is turned on by pressing operation as in the second aspect of the present invention. It enables a stable engine start without worrying about time.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 relate to an embodiment of the present invention, FIG. 1 is a circuit configuration diagram of an engine control system, and FIG.
Is a flow chart of the starter control routine, and FIG. 3 is a time chart for starting the engine.

In FIG. 1, reference numeral 1 is an engine, reference numeral 2
Is a transmission connected to the output shaft of the engine 1, and reference numeral 3 is a starter for starting the engine 1. The starter 3 of the engine 1 and various actuators and sensors described below are electronic control units (ECU). ) 20 and the engine 1 is controlled. The ECU 20 is the CPU 2
1, ROM22, RAM23, backup RAM2
4, a counter / timer group 25, and an I / O interface 26 are mainly configured by a microcomputer connected to each other via a bus line, and a constant voltage circuit 27, I for supplying a stabilized power supply to each part. Drive circuit 28 and A / D connected to the I / O interface 26
Peripheral circuits such as the converter 29 are built in.

The constant voltage circuit 27 is connected to the battery 31 via the first relay contact of the power supply relay 30 having two circuit relay contacts, and is also directly connected to the battery 31, and the ignition switch 32 is connected to the constant voltage circuit 27. When the contact of the power relay 30 is closed by being turned on, power is supplied to each part in the ECU 20 while the ignition switch 32 is turned on.
Regardless of whether it is ON or OFF, backup RAM2 is always available.
Supply power to 4 for backup. Furthermore, the starter 3 is connected to the battery 31 via a relay contact of the starter relay 33. The second of the power relay 30
A power line for supplying power from the battery 31 to each actuator is connected to the relay contact of.

The input port of the I / O interface 26 includes an ignition switch 32, an idle switch 4 which is turned on when a throttle valve (not shown) of the engine 1 is fully closed, a knock sensor 5 for detecting knocking of the engine 1, a crank angle. A crank angle sensor 6 for detecting the cylinder speed, a cylinder discrimination sensor 7 for discriminating a fuel injection target cylinder or an ignition target cylinder, a vehicle speed sensor 8 for detecting a vehicle speed, a starter switch 9 and the like are connected. The starter switch 9 is a push-button type switch that is disposed in the instrument panel portion, steering portion, or the like of the passenger compartment. When the engine 1 is started, the starter switch 9 is pushed for a predetermined period of time, and the starter control by the ECU 20 controls the engine 1
Will start.

Further, an input port of the I / O interface 26 is provided with an throttle opening sensor 10 for detecting a throttle opening and an intake air for detecting an intake air amount via an A / D converter 29. The quantity sensor 11, the cooling water temperature sensor 12 for detecting the cooling water temperature, the O2 sensor 13 for detecting the air-fuel ratio, etc. are connected, and the battery voltage VB is input and monitored.

On the other hand, at the output port of the I / O interface 26, each relay coil of the power relay 30 and the starter relay 33, an idle for controlling the idle speed by finely adjusting the air amount of the intake system during idle operation. A rotation speed control valve (ISC valve) 14, an injector 15 for injecting fuel into the intake pipe, etc. are connected through a drive circuit 28, and the ignition coil (not shown) is intermittently energized to spark the spark plug. Igniter 16 for discharging
Are connected.

The CPU 21 processes the detection signals from the sensors and switches input via the I / O interface 26, the battery voltage, etc., according to the control program stored in the ROM 22, and stores them in the RAM 23. Based on the data, various learning value data stored in the backup RAM 24, fixed data stored in the ROM 22, etc., the control amount such as the fuel injection amount and the ignition timing is calculated, and the engine for the fuel injection control, the ignition timing control, etc. Take control.

In this case, the ECU 20 manages the starting of the engine 1 by automatically controlling the starter 3 when the ignition switch 32 and the starter switch 9 are turned on by the driver's operation. In this starter control, whether or not an engine start condition is satisfied in which the time after the power supply to the ECU 20 is turned on for the first set time or longer and the time for turning on the starter switch 9 continues for the second set time or longer is satisfied. When it is determined that the engine start condition is satisfied, the starter relay 33 is turned on to operate the starter 3 and crank the engine 1. Then, after cranking the engine 1, depending on the result of the complete explosion determination of whether or not the engine 1 has completed the explosion, the starter relay 33 is kept on even if the starter switch 9 is turned off until the engine complete explosion. Then, the operation of the starter 3 is continued, and when it is determined that the engine has completely exploded, the starter 3 is stopped.

That is, the ECU 20 has the functions of the engine starting condition determining means, the complete explosion determining means, and the starter control means according to the present invention. Specifically, the functions of each means are controlled by the starter control routine shown in FIG. To be realized. Below, E
The processing relating to the engine start control by the CU 20 will be described with reference to the flowchart of the starter control routine of FIG.

In this starter control routine, the ECU 20 is powered on when the ignition switch 32 is turned on, and the initialization process (clearing various count values and flags excluding the data stored in the backup RAM 24) is completed, and then a predetermined time is elapsed. (For example, 10ms
This is a routine executed every ec). First, in step S1, it is determined whether or not the engine 1 has reached the complete explosion state. In the present embodiment, the engine speed NE is used as a parameter for the complete explosion determination, and this engine speed NE is compared with the complete explosion speed N1 (for example, 350 to 500 rpm). Since the intake pipe pressure changes as the engine starts, the intake pipe pressure may be used as a parameter for the complete explosion determination.In addition, the complete explosion determination may be made by the change of the exhaust temperature of the engine and the change of the battery voltage. May be.

At the beginning of the routine when the ECU 20 is powered on and the routine is started, NE <N1 is satisfied because the starter 3 is not operating, and steps S1 to S2 are performed.
Proceed to and clear the complete explosion duration time count value CNTKB for measuring the duration of the complete explosion state (CNTKB ←
0), in step S3, the ECU power ON time count value CNT ECUON for measuring the elapsed time after the power supply to the ECU 20 is turned on, and the first determination threshold value C1 (the determination threshold value that determines the first set time; ~ 2sec equivalent value)
Compare with. As a result, if CTECUON ≧ C1, jump to step S5, and
<C1, in step S4, the time count value CNECUON after turning on the ECU power is counted up (CN
TECUON ← CTECUON + 1), step S5
Go to.

In step S5, the starter switch ON continuation time count value CNTSTSW for measuring the ON time of the starter switch 9 and the second value are used to check the time when the starter switch 9 is pressed (ON).
The determination threshold value (determination threshold value that determines the second set time; for example, a value equivalent to 0.5 sec) is compared. And CN
If TSTSW <C2, it is checked in step S6 whether or not the starter switch state STSW indicating the ON / OFF state of the starter switch 9 is ON.

As a result, when STSW = OFF,
From step S6 to step S7, the starter switch ON duration count value CNTSTSW is cleared (CNTSTSW ← 0), and in step S8 the starter relay 33 is turned off and the routine exits. Also, ST
When SW = ON, steps S6 to S9
To, starter switch ON continuous time count value C
Count up NTSTSW (CNTSTSW ← C
NTSTSW + 1), and in step S8, the starter relay 33 is turned off and the routine is exited.

After that, when the ON time of the starter switch 9 reaches the time determined by the second judgment threshold value C2 and CNTSTSW ≧ C2 in step S5, the process proceeds from step S5 to step S10, and the ECU power ON time count value CNECUON is set. It is checked whether or not the first judgment threshold value C1 is exceeded. And CNT ECUON <
In the case of C1, in step S8 described above, the starter relay 33 is maintained in the OFF state and the routine is exited.
If ON ≧ C1, in step S11, the starter relay 33 is turned on to start the operation of the starter 3, and the routine exits.

That is, the elapsed time after the power supply to the ECU 20 is equal to or longer than the first set time determined by the first determination threshold C1, and the duration of the starter switch ON is determined by the second determination threshold C2. When the set time is exceeded, the starter relay 33 is turned on and the starter 3
By starting the operation of, the misjudgment due to temporary noise or the like is prevented and the chattering of the judgment is prevented. The first determination threshold value C1 and the second determination threshold value C2 are obtained in advance by simulation or experiment in consideration of the characteristics of the control system, and are stored in the ROM 22 as fixed data, so that the system functions effectively. In the state, for example, the O2 sensor 13 is activated by the built-in heater, and in the system that supplies the assist air to the injector 15, the assist air is ready to be pressurized, and the driver turns on the starter switch 9. The starter 3 is operated in a minimum time from, and the value is set so that the driver does not feel uncomfortable.

After starting the operation of the starter 3, step S1
In the case where NE <N1 and the engine speed does not reach the complete explosion speed, CNT ECUON ≧ C1 and CNTSTS
If W ≧ C2, steps S2 to S3, S
After 5 and S10, the process proceeds to step S11, the ON state of the starter relay 33 is maintained, and the starter switch 9 is turned off.
Even if the starter 3 is operated, the operation of the starter 3 is continued. When NE ≧ N1 in step S1, the process proceeds from step S1 to step S12, and the complete explosion continuation time count value CNTK
It is checked whether or not B has reached the third determination threshold value C3 (equivalent value of 0.2 to 2 sec), and if CNTKB <C3, the process proceeds to step S13 and the complete explosion duration time count value CNTKB is counted up. ((CNTKB ← CNTK
B + 1), with the starter relay 33 kept ON,
Exit the routine.

After that, the state of NE ≧ N1 continues and CN
When TKB ≧ C3, it is determined that the engine has completely exploded. That is, by determining the complete explosion only when the engine speed is equal to or higher than the complete explosion speed for the time determined by the third determination threshold value C3, erroneous determination due to noise or the like is prevented, and determination hunting is performed. To prevent. Then, when the complete explosion is determined, the process jumps from step 12 to step S7, and the starter switch ON duration time count value CNTS
After clearing TSW, the starter relay 33 is turned off to stop the operation of the starter 3 in step S8, and the routine is exited.

The above processing flow will be described with reference to the time chart of FIG. First, at time T1, the driver turns on the ignition switch 32 to turn on the power to the ECU 20, and at time T2, the push button starter switch 9 is turned on by the driver's pressing operation.
It is checked whether or not the elapsed time after the CU power is turned on and the duration of the starter switch ON have reached the set time determined by the first determination threshold C1 and the set time determined by the second determination threshold C2, respectively.

Next, the elapsed time after turning on the ECU power is equal to or longer than the set time determined by the first determination threshold C1, and the duration of the starter switch ON is the second determination threshold C.
When the set time determined by 2 is exceeded (time point T3), the starter relay 33 is turned on, the operation of the starter 3 is started, and the engine is cranked. After the starter relay 33 is turned on, even if the starter switch 9 is turned off by the release of the push button by the driver (at time T
4), engine complete explosion is determined (in the present embodiment, the third determination threshold C when the engine speed NE is equal to or higher than the complete explosion speed N1).
When it continues for more than the time determined by 3, the starter relay 33 is kept ON and the operation of the starter 3 is continued until it is determined that the engine has completely exploded, thereby enabling a reliable engine start. Then, when it is determined that the engine has completely exploded (time T5), the starter relay 33 is turned off and the operation of the starter 3 is stopped.

As a result, the driver turns on the starter switch 9 once after turning on the ignition switch 32.
The ECU 20 automatically controls the operation of the starter 3 so that the system can function effectively and the engine can be started in the shortest time, so that the driver does not have to worry about the delay in starting the engine and the engine can be started stably. Therefore, it is possible to contribute to the reduction of exhaust emission.

[0030]

As described above, according to the present invention, the operation of the starter is automatically controlled by the driver simply turning on the power to the electronic control unit and turning on the starter switch once. It is possible to obtain a stable engine start without worrying about the start delay, and it is possible to contribute to the reduction of exhaust emission.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an engine control system.

FIG. 2 is a flowchart of a starter control routine.

[Fig. 3] Time chart of engine start

[Explanation of symbols]

1 engine 3 starter 9 starter switch 20 electronic control unit (engine starting condition determination means, complete explosion determination means, starter control means) C1 first determination threshold value (determination threshold value that determines a first set time) C2 second determination threshold value (Judgment threshold value that determines the first set time)

Claims (2)

[Claims] 1. A second set time period in which a time after turning on a power to an electronic control unit for controlling an engine has passed a first set time period or more and a starter switch for operating a starter is in an ON state. When the engine starting condition determining means for determining whether or not the engine starting condition to be continued is satisfied, the complete explosion determining means for determining whether or not the engine has completely exploded, and when it is determined that the engine starting condition is satisfied , Activating the starter, and then continuing the operation of the starter regardless of the on / off state of the starter switch, and a starter control means for stopping the starter when it is determined that the engine has completely exploded. A characteristic engine starting control device. 2. The engine start control device according to claim 1, wherein the starter switch is a push button type switch that is turned on by a pressing operation.