JP2001012271A - Automatic stop/start device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic stop/start device for an engine which can sufficiently obtain the merit of saving of fuel consumption, reduction of emission, etc., by immediately stopping the engine with no necessity for troublesome operation when a stop condition of the engine is effected. SOLUTION: When a stop condition is effected, a signal is generated over a prescribed time by a signal generating means (step S2 to step S6), when foot brake operation is released by a driver during generation of this signal (step S8), an engine is stopped to be based on an engine stop command of a stop intention decision means (step S14), thus the engine is immediately stopped when the brake operation is released, and this release operation relates to driving operation of a vehicle, so that the operation can be very naturally practicable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic stop / start system for an engine for automatically temporarily stopping the engine when the vehicle stops.

[0002]

2. Related Background Art Conventionally, an automatic stop / start device has been put to practical use in which an engine is automatically temporarily stopped when a vehicle is stopped at a traffic light or the like to reduce fuel consumption and emission. I have. This type of automatic stop and start device
For example, when a preset engine stop condition such as vehicle speed = 0, a neutral shift position, a clutch connection, etc. is satisfied, the engine is stopped, and then, when a preset engine start condition, such as clutch disengagement, is satisfied. The engine is started to prepare for starting of the vehicle.

[0003] The above-described engine stop / start processing is executed even in a situation where the vehicle repeatedly starts and stops slightly, such as during traffic congestion. In this case, the engine stop time is extremely short, so that the automatic stop is performed. In addition to the advantages described above, there is a problem that the start is delayed due to the start of the engine. Therefore, for example, in the automatic stop and start device described in Japanese Patent Application Laid-Open No. 9-42006, the engine stop is prohibited until a predetermined time elapses even if the engine stop condition is satisfied. Measures have been taken to avoid unnecessary engine stoppage by continuing operation. As another proposal, a switch for instructing the driver to stop the engine is provided in the driver's seat, and a measure to stop the engine on condition that the engine stop condition is satisfied and the switch is operated by the driver is also considered. Have been.

[0004]

However, in the above-described automatic stop / start device at the preceding stage, even if the engine stop condition is satisfied, the engine is not stopped until a predetermined time elapses. There was a problem that the effect of reduction was not obtained and the merit was reduced by half. Further, in the automatic stop / start device at the subsequent stage, a switch operation completely unrelated to the driving operation is required every time the engine is stopped, so that the operation is complicated.

It is an object of the present invention to automatically stop an engine without complicated operations when an engine stop condition is satisfied, and to obtain an engine with sufficient advantages such as fuel economy and emission reduction. It is to provide a stop / start device.

[0006]

In order to achieve the above object, according to the present invention, the engine is stopped by the engine stop means when the stop condition is satisfied, and the engine is stopped by the engine start means when the start condition is satisfied. A signal generating means for generating a signal for a predetermined time when a stop condition is satisfied, and when a specific operation related to the driving operation of the vehicle is performed during the signal generation. And means for determining the intention to stop the engine.

Therefore, a signal is generated by the signal generating means when the stop condition is satisfied, and when a specific operation is performed during the generation of the signal, the engine stop means operates based on the stop command of the stop intention determination means. Since the engine is stopped, the driver can select the continuation or stop of the operation of the engine according to whether or not to execute the specific operation during the signal generation.

If the specific operation is executed in response to the signal generation, the engine is immediately stopped, so that the fuel saving and emission reduction effects can be obtained from that point, and the specific operation is performed on the vehicle. , The engine can be stopped without performing a complicated operation only by performing a very natural operation.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an automatic stop / start device for a gasoline engine will be described below. As shown in the overall configuration diagram of FIG. 1, a manual transmission 2 is connected to the engine 1 of the present embodiment.
Are connected to the drive wheels of the vehicle via a differential device (not shown). The engine 1 is provided with an ignition plug 3 and a fuel injection valve 4 for each cylinder. As is well known, fuel is injected from the fuel injection valve 4 into intake air introduced into each cylinder, and the ignition plug 3 ignites the fuel. By doing so, the engine 1 is driven.

In the passenger compartment, an input / output device (not shown), a storage device (ROM, RAM, BURAM, etc.) for storing control programs and control maps, etc., and a central processing unit (C
An ECU (engine control unit) 11 having a PU, a timer counter, and the like is provided. On the input side of the ECU 11, a shift position sensor 12 for detecting a shift position of the transmission 2, a vehicle speed sensor 13 for detecting a vehicle speed V, and a connection state of a clutch (not shown) provided between the engine 1 and the transmission 2 are detected. A clutch sensor 14, a brake sensor 15 for detecting an operation state of a foot brake of the vehicle, an accelerator sensor 16 for detecting an operation state of an accelerator of the vehicle,
And various other sensors and switches.

On the output side of the ECU 11, the ignition plug 3, the fuel injection valve 4, and a starter 17 for starting the engine are connected via a relay 18, and are provided in a driver's seat to emit sound or light. Actuators such as a signal device 19 for informing the driver using the automatic braking device 20 and a brake device 20 capable of automatically performing braking while the vehicle is stopped are connected. The automatic brake device 20 is a device that can operate independently of the foot brake. For example, the automatic brake device 20 is configured to increase a brake hydraulic pressure by using a hydraulic pump of an ABS system mounted on the vehicle and to brake the vehicle arbitrarily. Have been. The ECU 11 performs various controls for operating the engine 1, such as fuel injection control and ignition timing control, based on the information detected by the sensor.
The automatic stop / start control is executed when the vehicle is temporarily stopped, as described below.

Next, the processing performed by the automatic stop / start device configured as described above will be described. ECU 1 is shown in FIG.
Is executed at a predetermined control interval (for example, 10 msec). First, the ECU 11 determines whether or not a preset engine stop condition is satisfied in step S2. The following requirements are set as engine stop conditions, and it is considered that the engine stop condition is satisfied when all the requirements are satisfied.

1) The vehicle speed V = 0 is detected by the vehicle speed sensor 13 2) The clutch connection is detected by the clutch sensor 14 3) The shift position detected by the shift position sensor 12 is N (neutral) ) Position 4) Accelerator non-operation detected by accelerator sensor 16 5) Foot brake operation detected by brake sensor 15 When the vehicle is running, the above 1) to 5) are performed. Since any of the conditions is not satisfied, the determination of NO (No) is made in step S2, and the routine ends. Therefore, in this case, the automatic stop / start processing described below is not executed, and the operation of the engine 1 is continued.

On the other hand, the vehicle stops (vehicle speed V = 0), for example, when waiting for a traffic light, and the shift position is returned to the N position by the driver to stop the operation of depressing the clutch. , The accelerator is not operated), since all of the above conditions 1) to 5) are satisfied,
In step S2, a determination of YES (affirmation) is made, and
Move to S4. In step S4, a signal is generated from the signal device 19, and in subsequent step S6, it is determined in step S8 whether a preset signal time TSG has elapsed.
It is determined whether or not the operation of the foot brake has been released based on the detection of the brake sensor 15. Until the signal time TSG elapses in step S6 or the brake is released in step S8, the signal is continued by the processing in step S4. If the brake is released before the signal time TSG elapses, step S8 is performed. Then, the determination of YES is made, and the process proceeds to step S10.

In this embodiment, the signal device 19 and the EC for executing the processing of steps S4 and S6 are used.
U11 functions as a signal generating means, and the ECU for executing the processing of step S8 with the brake sensor 15
11 functions as stop intention determination means. Step S
In step 10, it is determined whether or not an accelerator operation is detected by the accelerator sensor 16, and in subsequent step S12, it is determined whether or not a preset pedal depression time TP has elapsed. When the time TP has elapsed, a determination of YES is made in step S12, and the process proceeds to step S14. Then, in step S14, the fuel injection control and the ignition timing control by another routine are stopped to stop the engine 1, and the automatic braking device 20
Is operated to brake the vehicle and prevent the vehicle from moving due to the inclination of the road surface or the like.

Thereafter, in step S16, it is determined whether a preset engine start condition has been satisfied. The following requirements are set as the engine start conditions, and it is considered that the engine start conditions are satisfied when all the requirements are satisfied. 6) The clutch disengagement is detected by the clutch sensor 14 7) The shift position detected by the shift position sensor 12 is the N position When the engine start condition is not satisfied, step S16
Then, the process returns to step S14, and this process is repeated. Therefore, the engine 1 is kept stopped unless the engine start condition is satisfied, and the braking by the automatic brake device 20 is continued. When the driver steps on the clutch, the engine start condition is satisfied,
The ECU 11 proceeds to step S18 to operate the starter 17 by exciting the relay 18 to perform cranking, and to restart the fuel injection control and the ignition timing control to start the engine 1. In step S18, the automatic braking device 20 is stopped to release the braking of the vehicle to prepare for starting, and thereafter, the routine ends.

In the present embodiment, the ECU 11 at the time of executing the processing of steps S2 and S14 functions as an engine stop means, and executes steps S16 and S14.
The ECU 11 at the time of executing the processing of 18 functions as engine starting means. On the other hand, when the signal time TSG has elapsed without releasing the brake operation in steps S6 and S8, a determination of YES is made in step S6, and the routine ends. Therefore, in this case, the engine 1 continues to operate without being stopped as described above.

Step S10 and step S1
If the accelerator operation is performed by the driver before the pedal depressing time TP elapses in step 2, a YES determination is made in step S10, and the routine ends. Pedal change time T
P is set to a time slightly longer than the normal time required to change the pedal from the brake to the accelerator, for example, about 2 seconds. Therefore, in such a situation, it is considered that the brake operation has been released in order to perform the accelerator operation with the intention of starting, and the engine 1 is continued because it is not appropriate to stop the engine 1.

As described above, steps S4 to S
In the process of No. 8, the driver determines whether to continue the operation of the engine 1 (determined as YES in step S6) or stopped (determined as YES in step S8) depending on whether to continue or release the foot brake operation during the signal generation. Can be selected. Therefore, for example, when waiting for a normal traffic light, the engine 1 is stopped by intentionally releasing the brake operation to reduce fuel consumption and emission, or in a situation where starting and stopping such as traffic congestion are repeated, the brake operation is not performed. By continuing, it is possible to continue the operation of the engine 1 and avoid useless stopping of the engine. In addition, the above-mentioned signal time TSG
Is set to a time that allows the driver to determine whether to continue or stop the operation of the engine 1 with a margin, for example, about 5 seconds.

Since the engine 1 is stopped on condition that the operation of the foot brake is released, the engine 1 is immediately stopped when the driver releases the operation of the foot brake in response to the signal. . Therefore, the engine 1 can be stopped immediately after the engine stop condition is satisfied, and the fuel consumption can be saved and emission can be reduced from that point in time, as compared with the technique disclosed in Japanese Patent Application Laid-Open No. 9-42006 in which the engine stop is prohibited until a predetermined time has elapsed. The effect of reduction can be obtained.

The release of the foot brake operation is closely related to the driving operation when the vehicle is stopped. Specifically, when the vehicle is stopped, the foot brake is naturally depressed. The engine 1 is stopped simply by canceling. That is, unlike the prior art in which a switch for instructing the engine stop is provided in the driver's seat, the stepped foot brake is released without requiring a complicated switch operation completely unrelated to the driving operation. The engine 1 can be stopped simply by performing a natural operation.

Therefore, according to the start / stop / start device of the engine 1 of the present embodiment, when the engine stop condition is satisfied, the engine 1 is immediately stopped without requiring a complicated operation to reduce fuel consumption and emission. Can be sufficiently obtained. The description of the embodiment is finished above, but aspects of the present invention are not limited to this embodiment. For example, in the above-described embodiment, the release of the foot brake operation is set as the specific operation based on the premise that the foot brake is depressed when the vehicle stops, but the specific operation includes various other operations. Can be set. For example, when the foot brake operation is not set as the engine stop condition 5), the brake operation may be released when the engine stop condition is satisfied. May be set as a specific operation. In this case, the driver can select whether to stop the engine or continue the operation depending on whether or not to re-operate and release the brake during the signal generation.

Further, the requirement for clutch connection which is the engine stop condition 2) may be set as a specific operation. That is,
In this case, after stopping the vehicle, the driver steps on the clutch to return the shift position to the N position, and then determines whether to stop the engine or continue the operation depending on whether the stop condition is satisfied and the clutch is connected during signal generation. Can be selected. Further, in a vehicle with an automatic transmission, the shift switching from the D (drive) position to the N (neutral) position may be set as a specific operation, and in this case, the driver shifts during a signal generation after the vehicle stops. Can be selected to stop the engine or continue the operation depending on whether or not is switched from the D position to the N position.

On the other hand, in the above embodiment, the automatic stop / start device for the gasoline engine 1 is embodied. However, the type of the engine is not limited to this. The present invention may be applied to a hybrid vehicle in which the engine and the electric motor are combined, and may be embodied as a device for automatically stopping and starting the engine.

In the above-described embodiment, the requirements 1) to 5) are set as the stop conditions of the engine 1 and the requirements 7) and 8) are set as the start conditions. Can be arbitrarily changed according to the use of the vehicle, the type of the transmission, and the like. For example, an operation of a side brake may be added as an engine stop condition. Further, in the above-described embodiment, the automatic brake device 20 is provided to prevent the vehicle from moving when the vehicle is stopped. However, since the function thereof can be substituted by manual operation of the side brake, this device may be omitted.

[0026]

As described above, according to the apparatus for automatically stopping and starting an engine of the present invention, when a stop condition is satisfied, the engine is immediately stopped without any complicated operation, thereby reducing fuel consumption and emission. Etc. can be sufficiently obtained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram illustrating an automatic stop / start device for an engine according to an embodiment.

FIG. 2 is a flowchart illustrating an automatic stop / start routine executed by an ECU.

[Explanation of symbols]

11 ECU (engine stop means, engine start means,
Signal generation means, stop intention determination means) 15 Brake sensor (stop intention determination means) 19 Signal device (signal generation means)

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 3D037 FA13 FB00 FB05 3G092 AA01 AA05 AC03 BA10 CA02 EA13 EA14 EA17 EB06 EB09 HF05X HF08Z HF12Z HF15Z HF21Z HF26Z 3G093 AA04 AA15 DB20 DB01 EA05 EA12 EC01 FA11 FB02

Claims (1)

[Claims] An automatic stop / start device that stops an engine by an engine stop means when a stop condition is satisfied and starts the engine by an engine start means when a start condition is satisfied, wherein the stop condition is satisfied. A signal generating means for generating a signal over a predetermined period of time; and when the driver performs a specific operation related to the driving operation of the vehicle during the signal generation by the signal generating means, the engine generates the signal. An automatic stop / start device for an engine, comprising stop means for instructing a stop means to stop the engine.