JP2001159321A - Control device for internal combustion engine for vehicles - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent overdischarge of a battery and improve fuel efficiency while securing restart performance after an idle operation stop of an internal combustion engine for a vehicle. After the idle operation is forcibly stopped when the vehicle is stopped, the power of the electronically controlled throttle system is turned off after a lapse of a set time, and the opening of the throttle valve is mechanically set to an opening required for restarting the engine. (S1 to S5), when the accelerator operation is performed and the restart condition is satisfied, the electric motor is driven, cranking and fuel injection are restarted, and the engine is restarted.
After the complete explosion, control is performed such that the opening of the throttle valve gradually approaches the target opening corresponding to the accelerator operation amount (S6 to S)
9). Thus, overdischarge of the battery when the engine is stopped can be prevented, and the fuel efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled throttle system for electronically controlling the opening of a throttle valve, and forcibly stopping an idle operation of an engine when the vehicle is stopped, and driving an electric motor by operating an accelerator after the stop. An idle stop / restart system that restarts the engine and starts the vehicle.
The present invention relates to a vehicular internal combustion engine including:

[0002]

2. Description of the Related Art In recent years, to reduce fuel consumption and improve exhaust gas purification,
2. Description of the Related Art There is known an idle stop / restart system in which an idle operation of an engine is forcibly stopped when the engine is stopped, an electric motor is driven by an accelerator operation after the stop, the engine is restarted to restart the vehicle.

In a vehicular internal combustion engine provided with such a system, the electronically controlled throttle system is provided in order to prevent a sudden start due to a sudden opening of a throttle valve in response to depression of an accelerator pedal when the vehicle restarts. When the vehicle is stopped, the throttle valve opening is set to the opening required at the time of restart, and at the time of restart, the opening is maintained until the idle rotation speed is reached, and then the opening is adjusted according to the amount of depression of the accelerator pedal. There has been proposed a technique for controlling the opening so as to gradually increase the opening (see Japanese Patent Application Laid-Open No. 8-193,531).

[0004]

However, in the above-mentioned prior art, when the idle operation stop state at the time of stopping the vehicle continues for a long time, power is supplied to the electronically controlled throttle system without charging the battery in the engine stop state. As a result, the battery may be over-discharged, and the fuel efficiency is also reduced.

The present invention has been made in view of such conventional problems, and is intended to control a vehicle internal combustion engine capable of smoothly restarting while preventing overdischarge during idling operation when the vehicle is stopped. It is intended to provide a device.

[0006]

According to the present invention, as shown in FIG. 1, an electric actuator which opens and closes a throttle valve by an electric actuator so as to reach a target opening in accordance with an engine operating condition. A throttle control system, and an idle stop / restart system that forcibly stops idle operation of the engine when the vehicle is stopped, drives an electric motor by operating an accelerator after the stop, restarts the engine, and starts the vehicle. In an internal combustion engine for a vehicle, the opening of the throttle valve when the power of the electronically controlled throttle system is turned off is set to an opening for supplying an air amount necessary for restarting the engine to the engine. Means for shutting off the power of the electronically controlled throttle system when the engine is forcibly stopped.

According to the first aspect of the present invention, when the vehicle is stopped, the idle operation of the engine is forcibly stopped by stopping the fuel injection or the like by the idle stop / restart system, and the electronically controlled throttle system is turned off by the power supply shutoff means. Is turned off, whereby the opening of the throttle valve is set by the restart opening setting means to an opening for supplying an amount of air required for restarting the engine to the engine.

As described above, since the power supply of the electronically controlled throttle system is turned off during the forced stop of the idle operation, overdischarge of the battery is prevented. When the vehicle is restarted by operating the accelerator, the opening of the throttle valve is set to the opening for supplying the engine with the amount of air necessary for restarting the engine, so that the vehicle can be prevented from suddenly starting.

Further, the invention according to claim 2 is characterized in that the power supply shut-off means turns off the power of the electronically controlled throttle system after a forced stop operation of the engine.

According to the second aspect of the present invention, the opening of the throttle valve can be quickly increased by delaying the power-off operation of the electronically controlled throttle system in response to the forcible stop operation of the idle operation such as the stop of the fuel injection. Thus, it is possible to prevent the occurrence of a deceleration shock caused by reducing the amount of air necessary for restarting the engine to the opening for supplying the engine, and to smoothly stop the operation.

According to a third aspect of the present invention, the delay time for turning off the power of the electronically controlled throttle system with respect to the forcible stop operation of the engine by the power supply shutoff means is set according to the intake negative pressure of the engine. It is characterized by that.

According to the third aspect of the invention, by setting the delay time according to the intake negative pressure of the engine, it is possible to set the minimum delay time necessary for a smooth stop of the operation while ensuring a fuel efficiency improvement effect. .

According to a fourth aspect of the invention, when the engine is restarted, the opening degree of the throttle valve and the amount of air required for restarting the engine are determined until the restart of the engine by the electric motor is completed. The opening degree to be supplied to the engine is maintained, and after the restart is completed, control is performed to gradually approach the opening degree according to the accelerator operation amount.

According to the fourth aspect of the present invention, a smooth restart can be performed while preventing a sudden start of the vehicle.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a system configuration according to an embodiment of the present invention.

The accelerator operation amount sensor 1 detects an accelerator operation amount (accelerator operation amount) depressed by a driver. The crank angle sensor 2 generates a position signal for each unit crank angle and a reference signal for each cylinder stroke phase difference, and measures the number of occurrences of the position signal per unit time, or measures the reference signal generation cycle. Thus, the engine speed is detected.

The air flow meter 3 detects the amount of air taken into the internal combustion engine 4. The water temperature sensor 5 detects a cooling water temperature of the engine. The engine 4 is provided with a fuel injection valve 6 which is driven by a fuel injection signal and injects fuel, and a spark plug 7 which is mounted in a combustion chamber and ignites. A valve 9 is provided, and an actuator 11 is provided which can electronically control the valve opening by driving the throttle valve 9 via a lever 10 connected to the valve shaft. Thus, an electronically controlled throttle system is configured.

The lever 10 has springs 1 on both sides.
2 and the spring 13 are connected, and in a state where the energization of the actuator 11 is turned off, the throttle valve 9 is held at a predetermined opening at a position where the urging forces of the two springs 12 and the spring 13 are balanced. It has become so. Here, the predetermined opening degree is set to an opening degree corresponding to supplying the engine 4 with an air amount necessary for restarting the engine 4 whose operation is stopped when the vehicle is stopped, which will be described later. For example, assuming that the opening set at the time of starting by a normal operation of the starter switch is the maximum opening (about 10 to 15 °) in the idle rotation speed control, the opening required for restart at the time of starting the vehicle is The opening is set to be sufficiently small (for example, about 5 °). This configuration corresponds to the restart opening degree setting means of the present invention.

The throttle valve 9 is provided with a throttle opening sensor 14 for detecting the opening of the throttle valve 9 and an idle switch 15 for detecting an idle position integrally with or separately from the throttle opening sensor 14. Have been.

In addition, a parking switch 16 for detecting a parking brake operation, a shift position sensor 17 for detecting a shift lever position of a transmission, a vehicle speed sensor 18 for detecting a vehicle speed, and the like are provided.

Further, an electric motor 19 for starting the engine 4 is provided. Detection signals from the various sensors are input to a control unit 20, and the control unit 20 controls the throttle valve 9 via the actuator 11 in accordance with an operation state detected based on a signal from the sensors. The opening degree is controlled, the fuel injection valve 6 is driven to control the fuel injection amount (fuel supply amount), the ignition timing is set, and the normal engine control for igniting the ignition plug 7 at the ignition timing is performed. .

When the control unit 20 detects that the vehicle is stopped, the control unit 20 stops fuel injection to the engine 4 to forcibly stop the idle operation, and drives the electric motor 19 by operating the accelerator after the vehicle is stopped. Restart the engine and start the vehicle. This function corresponds to an idle stop / restart system.

Further, as the control according to the present invention,
When the idle operation is forcibly stopped when the vehicle is stopped, the power supply to the actuator 11 is cut off by turning off the power of the electronically controlled throttle system. As a result, the throttle valve 9 is set to the opening corresponding to supplying the engine 4 with the amount of air necessary for restarting. This function corresponds to power supply shutoff means.

Hereinafter, the control at the time of stopping and restarting according to the present invention will be described with reference to the flowchart shown in FIG. In step (denoted as S in the figure, the same applies hereinafter) 1, it is determined whether or not a stop condition for forcibly stopping the idle operation has been detected. Specifically, the parking switch 16, shift position sensor 17, vehicle speed sensor 18
For example, based on the parking brake is applied,
Further, it is assumed that the shift lever is in the neutral position or the parking position, and the vehicle speed is set to the stopped state (substantially 0).

If a stop condition is detected in step 1, the program proceeds to step 2 in which fuel injection of the engine 4 is stopped to forcibly stop idling. In step 3, the elapsed time after the idle operation stop operation is measured.

In step 4, it is determined whether the elapsed time has reached a set time. Here, the set time is set to a time required for the negative pressure to be sufficiently reduced by the deceleration damper control for gradually decreasing the opening of the throttle valve 9 after the stop operation of the idle operation.

If it is determined in step 4 that the elapsed time has reached the set time, the routine proceeds to step 5, where the power supply to the actuator 11 is cut off by turning off the electric throttle system. As a result, the throttle valve 9 is set to the opening corresponding to supplying the engine 4 with the amount of air necessary for restarting. Further, since the throttle valve opening is set to the opening corresponding to the restart after the set time has elapsed, the operation can be smoothly stopped without generating a deceleration shock by the deceleration damper control.

Next, at step 6, it is determined whether or not a condition for restarting the vehicle by operating the accelerator is satisfied. Specifically, when it is detected that the shift lever is switched to the drive position and the accelerator operation is performed, it is determined that the restart condition is satisfied.

When it is detected in step 7 that the restart condition is satisfied, first, in step 6, the motor 19
To restart the fuel injection of the engine 4 while performing cranking.

In step 8, it is determined whether the restart has been completed (complete explosion). Until the restart is completed, the opening of the throttle valve 9 is maintained at the opening required for the restart. If it is determined in step 8 that the restart has been completed, the process proceeds to step 9 to drive the electronically controlled throttle system so that the opening of the throttle valve 9 gradually approaches the target opening corresponding to the accelerator operation amount. I do.

FIG. 4 shows how the throttle valve opening changes at the time of stopping and restarting. As a result, it is possible to prevent a situation in which the torque generated by the engine 4 becomes excessively large and the vehicle is suddenly started by the control based on the opening degree according to the accelerator operation amount, and the vehicle can be started smoothly.

Since the power of the electronically controlled throttle system is turned off when the vehicle is stopped while ensuring such smooth restarting performance, overdischarge of the battery when the engine is stopped can be prevented, and fuel consumption can be reduced. Also improve.

The present invention can be applied to a so-called hybrid engine in which a driving force during traveling is assisted by, for example, the starting motor or a separately provided electric motor, in addition to a vehicle using only an engine as a prime mover.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration and functions of the present invention.

FIG. 2 is an overall system configuration diagram in the embodiment.

FIG. 3 is a flowchart showing a stop and restart control routine according to the embodiment;

FIG. 4 is a flowchart showing how the throttle valve opening changes when the vehicle is stopped and restarted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Accelerator opening sensor 4 Internal combustion engine 6 Fuel injection valve 9 Throttle valve 10 Lever 11 Actuator 12 Spring 13 Spring 14 Throttle opening sensor 15 Idle switch 16 Parking switch 17 Shift position sensor 18 Vehicle speed sensor 19 Motor 20 Control unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Ichiro Fujimori 2nd Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa F-term (reference) in Nissan Motor Co., Ltd. 3G065 AA04 CA00 DA04 EA01 FA04 GA00 GA05 GA09 GA10 GA46 JA04 JA09 JA11 KA02 3G092 AA01 AA06 AA13 AB02 DC03 EA11 EA17 EA21 FA32 FA43 GA01 HA01Z HE01Z HE03Z HE08Z HF08Z HF19Z HF20Z 3G093 AA01 BA00 CA02 DA01 DA05 DA06 DA09 EA09 EC01 FA11 FA12 FB04

Claims (4)

[Claims] An electronically controlled throttle system that opens and closes with an electric actuator so as to open a throttle valve to a target opening in accordance with operating conditions of the engine, and forcibly stops idle operation of the engine when the vehicle is stopped. An idling stop / restart system for driving an electric motor by an accelerator operation to restart the engine and start the vehicle, and an opening degree of a throttle valve when a power supply of the electronically controlled throttle system is turned off. Opening degree setting means for setting an opening amount for supplying the amount of air necessary for restarting the engine to the engine, and turning off the power of the electronically controlled throttle system when the engine is forcibly stopped. A control device for a vehicle internal combustion engine, comprising: a power supply shutoff means. 2. The control of an internal combustion engine for a vehicle according to claim 1, wherein said power supply shut-off means turns off a power supply of an electronically controlled throttle system after a forced stop operation of said engine. apparatus. 3. A delay time for turning off the power of the electronically controlled throttle system in response to a forcible stop operation of the engine by the power supply shutoff means is set in accordance with the intake negative pressure of the engine. 3. The control device for a vehicle internal combustion engine according to 2. 4. When the engine is restarted, the opening of the throttle valve is maintained at an opening for supplying an amount of air required for restarting the engine to the engine until the restart of the engine by the electric motor is completed. The control device for a vehicle internal combustion engine according to any one of claims 1 to 3, wherein after the restart is completed, control is performed to gradually approach an opening degree according to the accelerator operation amount.