Automatic start-stop control device for internal combustion engine

Abstract

When a restart is requested in a period wherein the rotation speed of an engine descends within a rotation speed range in which the engine can be restarted without a starter (the engine can be restarted by only a fuel injection), during a fuel cutoff for an idling stop control, an independent return control is performed, i.e., an initial fuel injection is performed immediately and asynchronously before being returned to a synchronous fuel injection, and a starter-less start by which the engine is restarted by only a fuel injection without using a starter, is performed. Thus, when a request for restart arises, the asynchronously injected fuel is sucked to a cylinder in an air intake stroke, and is ignited in the vicinity of a subsequent compression TDC, to generate an initial combustion (initial ignition). Accordingly, the initial ignition can be generated one stroke earlier than ever before.

Description

technical field [0001] The present invention relates to an automatic stop and start control device for an internal combustion engine. The automatic stop and start control device for an internal combustion engine has the function of: When the restart request is met, the function of restarting the internal combustion engine immediately. Background technique [0002] In recent years, the number of vehicles equipped with automatic engine stop-start control systems (so-called idle stop control systems) has been increasing for the purpose of low fuel consumption and low emissions. With conventional general idle stop control systems, when the driver stops the vehicle, the fuel injection is stopped (fuel cut) to automatically stop the engine, and then the driver performs an operation to start the vehicle (brake release). During operation, accelerator pedaling operation, etc.), the starter or the motor that is also used as the starter is automatically energized to turn the crankshaf...

AI Technical Summary

Problems solved by technology

[0014] As a corresponding countermeasure, in the conventional system, it is necessary to estimate that the decrease in engine rotation from the generation of the restart request to the generation of the initial explosion is relatively large, and correspondingly, the determination threshold of the rotation speed that can be started without a starter is set to a relatively low value. As a result, the speed range that can be started without a starter will be reduced, so that the range of use of the starter will be increased, and the number of times the starter will be started will increase.

Moreover, in the case of restarting with a starter, the restart is carried out after the engine is stopped, or even if it is a constant mesh starter, until the engine speed drops below the lower limit of the speed that can be started without a starter. Restarting cannot be performed up to the starting speed range, so if Figure 4 As shown, it will take time from the generation of the automatic stop request to the completion of the restart, and the driver will feel the delay (slowness) of the restart.

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