JP2906931B2 - Engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine
Control to keep the engine speed below a specified value
Related to the device .

[0002]

2. Description of the Related Art In an engine for an automobile or the like, a control is performed to detect an abnormality of the engine such as a failure of an air flow meter or a disconnection of a control circuit and to control the engine speed to a predetermined value or less. There is something to prevent a secondary failure (reference material: "ECCS engine", Nissan Motor Co., Ltd. Sales Training Center, Showa 6
(Issued April 3rd).

FIG. 5 is a flowchart showing a control program executed by a conventional engine control device when an abnormality of an engine is detected. The control program is executed at regular intervals when an abnormality of the engine is detected.

First, at step 11, a detected value n of the engine speed is set to a predetermined regulation value Ncut (for example, 1800).
rpm) or more, and when the engine speed n reaches the regulation value Ncut, the process proceeds to step 12 to control the fuel supply to be stopped, and the fuel supply is continued in the revolution range lower than the regulation value Ncut. I do. As a result, the engine speed is kept lower than the regulation value Ncut.

[0005]

By the way, in a vehicle having an automatic transmission, gear position switching control is performed according to a map set in advance according to the engine load and the engine speed. Upshifting from the low gear position to the high gear position is basically performed by increasing the engine speed beyond a predetermined value.

However, as shown in FIG. 6, when an abnormality in the engine is detected during traveling in a low-speed gear and control is performed to suppress the engine speed to a predetermined value Ncut or less,
There is a problem that the rotation speed of the automatic transmission does not increase to the speed at which the upshift is performed, the low-speed gear position is not switched to the high-speed gear position, and the vehicle cannot travel at a practical speed with the low-speed gear. .

In view of the above problems, the present invention provides a control device for an engine mounted on a vehicle equipped with an automatic transmission, which can sufficiently increase the vehicle speed while suppressing the engine speed when an engine abnormality is detected. The purpose is to:

[0008]

The present invention SUMMARY OF], as shown in FIG. 1, the means 21 for detecting the anomalies engine, the automatic transmission of the engine rotational speed when detecting an abnormality of the engine
An engine speed regulating means 22 to keep below a predetermined value which is set lower than the shift-up rotational speed, a means 23 for detecting a gear position of the automatic transmission, in a running state automatic transmission is in low gear position the engine There is provided delay means 24 for delaying the control for suppressing the rotation speed to a predetermined value or less by a predetermined delay time.

[0009]

When the automatic transmission detects a malfunction in the engine while the vehicle is in the low gear position, the engine speed is automatically shifted by delaying the control for keeping the engine speed below a predetermined value by a predetermined delay time. The automatic transmission is sequentially switched from the low gear position to the high gear position, and the vehicle speed can be sufficiently increased.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 2, 1 is an engine body, 2 is an intake passage, 3 is an exhaust passage, 4 is an intake valve, and 5 is an exhaust valve.

Reference numeral 7 denotes a fuel injection valve for injecting fuel into the intake passage 2, and reference numeral 8 denotes an ignition plug for igniting an air-fuel mixture in a combustion chamber 9.

A control device 11 is provided for controlling the amount of fuel injected from the fuel injection valve 7 and for controlling the ignition timing of an ignition device 10 for igniting the ignition plug 8.

The control device 11 adjusts the fuel injection amount from the fuel injection valve 7 to an optimum injection amount according to the operating conditions.
Basically, the calculation is performed in accordance with the intake air amount detected by the air flow meter 12 and the engine speed detected by the speed sensor 13.

The control device 11 basically adjusts the ignition timing of the spark plug 8 according to the fuel injection pulse width corresponding to the engine load and the engine speed so that the optimum ignition timing is obtained according to the operating conditions. And calculate.

Further, the control device 11 detects an abnormality of the engine such as a failure of the air flow meter 12 or a disconnection of a circuit, and stops the fuel supply so as to suppress the engine speed to a predetermined value or less when the engine 1 is abnormal. Perform control. This prevents high-speed operation when the engine 1 is abnormal, and prevents a secondary failure from occurring.

In a vehicle equipped with an automatic transmission, the engine load detected by the accelerator opening sensor 16 or the opening sensor 17 of the throttle valve 14 and the engine speed sensor 13
The gear position switching control is performed according to the contents of a preset map in accordance with the engine speed detected by the engine.
Switching from the low gear position to the high gear position is basically performed by increasing the engine speed beyond a predetermined value.

However, by performing the fuel supply stop control so that the engine speed can be suppressed to a predetermined value or less when the engine 1 is abnormal, the switching from the low-speed gear position to the high-speed gear position is not performed. There is a problem that it is not possible to run at a speed.

To cope with this, the control device 11 is provided with a sensor 15 for detecting the gear position of the automatic transmission, and when the abnormality of the engine 1 is detected while the automatic transmission is running at the low gear position, the engine 15 A control for delaying the control for suppressing the rotation speed to a predetermined value or less by a predetermined time is performed, thereby enabling switching from the low gear position to the high gear position.

FIG. 3 is a flowchart showing a control program executed by the control device 11 when an abnormality of the engine is detected. The control program is executed at regular intervals when an abnormality of the engine 1 is detected.

First, in step 1, it is determined whether or not the detected value of the engine speed is equal to or higher than a predetermined delay start determination speed Nj (for example, 1400 rpm). In a speed range lower than the delay start determination speed Nj, fuel supply is performed. To continue.

When the detected value of the engine speed is equal to or higher than the predetermined delay start determination speed Nj, the routine proceeds to step 2, where it is determined whether or not the automatic transmission is at the low gear position. If in position, step 4
When the engine speed is equal to or higher than a predetermined regulation value Ncut (for example, 1800 rpm), control to stop fuel supply is performed, and the engine speed is set to a predetermined reference value Nre.
When it is equal to or less than c (for example, 1600 rpm), the fuel supply control is performed so as to return the fuel supply.

If the engine speed is equal to or higher than the predetermined delay start determination speed Nj and the automatic transmission is at the low gear position, the process proceeds to step 3 and the predetermined speed is exceeded after the delay start determination speed Nj is exceeded. After elapse of the delay time (for example, 10 seconds), the process proceeds to step 4 to perform fuel supply control. In this way, when the abnormality of the engine 1 is detected in the running state where the automatic transmission is in the low gear position, the control for suppressing the engine speed to 1800 rpm or less is delayed by a predetermined delay time, for example, as shown in FIG. As shown, while the delay time has not elapsed, the engine speed is increased to the speed at which the automatic transmission is upshifted, and the automatic transmission is sequentially switched from the low gear position to the high gear position, which is practical. It is possible to run at different speeds.

[0024]

As described above, according to the present invention, in an engine mounted on a vehicle equipped with an automatic transmission, a means for detecting when the engine is abnormal, and suppressing the engine speed to a predetermined value or less when the engine is abnormal. Means for controlling the engine speed, means for detecting the gear position of the automatic transmission, and control for suppressing the engine speed to a predetermined value or less when an abnormality is detected in the engine while the automatic transmission is in the low gear position. Since the delay means for delaying by the time is provided, when an abnormality of the engine is detected, the upshift is performed while the engine speed is suppressed, and the vehicle can be driven at a practical speed.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims of the present invention.

FIG. 2 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart showing control contents for regulating the engine speed.

FIG. 4 is a diagram showing an example of a change in engine speed when an engine abnormality is detected.

FIG. 5 is a flowchart showing control contents for regulating an engine speed in another embodiment.

FIG. 6 is a diagram showing an example of a change in engine speed when an engine abnormality is detected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine main body 2 Intake passage 3 Exhaust passage 7 Fuel injection valve 11 Control device 15 Gear position sensor 21 Engine abnormality detection means 22 Engine speed regulation means 23 Gear position detection means of automatic transmission 24 Delay means at low gear position

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 29/00-29/06 B60K 41/00-41/28 F02D 41/00-41/40

Claims (1)

(57) [Claims] 1. A means for detecting abnormalities of engine, automatic transmission and the engine speed when an abnormality is detected in the engine
Means for restricting the engine speed to below a predetermined value set lower than the upshift speed of the engine , means for detecting the gear position of the automatic transmission, and the engine in a running state where the automatic transmission is in the low gear position. An engine control device comprising: delay means for delaying a control for suppressing the number of revolutions to a predetermined value or less by a predetermined delay time.