Control apparatus for an internal combustion engine

Abstract

A control apparatus for an internal combustion engine can control an actual operating characteristic with high precision by shortening a response time thereof. The control apparatus capable of changing an actual phase angle of a camshaft by an OCV includes a crank angle sensor for detecting a crank angle of a crankshaft and generating a crank angle signal, an actual phase angle detection section for detecting the actual phase angle of the camshaft, an air flow sensor and a throttle position sensor for detecting an operating state of the engine, a target phase angle calculation section for calculating a target phase angle based on the operating state, and a phase angle feedback control section for calculating an operation amount to the OCV so as to make the actual phase angle coincide with the target phase angle. The phase angle feedback control section calculates the operation amount in synchronization with the crank angle signal.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a control apparatus for changing the operating characteristic of an internal combustion engine in accordance with the operating state thereof, and more particularly, it relates to a control apparatus for an internal combustion engine which servers to control, for example, the opening and closing timing (valve timing) of an intake valve and an exhaust valve by changing the phase angle of a camshaft with respect to that of a crankshaft of the internal combustion engine.[0003]2. Description of the Related Art[0004]Conventionally, there has been known a control apparatus for an internal combustion engine which can change the operating characteristic of the internal combustion engine by means of an actuator.[0005]Hereinafter, reference will be made, as an example, to a case where the operating characteristic of an internal combustion engine is the phase angle of a camshaft with respect to tha...

AI Technical Summary

Benefits of technology

[0023]Accordingly, the present invention is intended to obviate the problems as referred to above, and has for its object to provide a control apparatus for an internal combustion engine which is capable of shortening a control delay time thereby to decrease the response time of an actual engine operating characteristic, and of controlling the actual engine operating characteristic with a high degree of precision.

[0025]According to the control apparatus for an internal combustion of the present invention, since the operation amount feedback control section calculates the amount of operation for the actuator in synchronization with the crank angle signal, there is no deviation between the detection timing of the actual engine operating characteristic and the execution timing of the phase angle feedback control, and the control delay time is shortened, so the gain of the phase angle feedback control can be set to a large value, thereby making it possible to shorten the response time of the actual phase angle.

[0026]In addition, the amount of operation for the actuator is always calculated based on the latest actual engine operating characteristic, so it is possible to control the actual engine operating characteristic with high accuracy.

Problems solved by technology

As a result, there is a possibility that a control delay time until the start of operation of the valve timing variable mechanism might be lengthened.

In the known valve timing control apparatus for an internal combustion engine, the gain of the phase angle feedback control can not be set to a large value, so there has been a problem that the response time of the actual phase angle becomes relatively long.

In addition, when the internal combustion engine is rotating at low rotational speed, the amount of operation for the valve timing variable mechanism is repeatedly calculated based on the same actual phase angle that was previously detected and is different from a current actual phase angle until the current or fresh actual phase angle is detected and updated, so there has also been a problem that the control accuracy of the actual phase angle is reduced.

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