Intake air volume controller of internal combustion engine

Abstract

An intake air amount control system for an internal combustion engine, which controls respective amounts of intake air drawn into four cylinders #1 to #4, independently of each other, by variable inter-intake cam phase mechanisms 80, identifies intake air amount variation coefficients ¦#i, based on a model [equation (43)] defining a relationship between an estimated value Gth_est of a TH passing intake air amount and a plurality of simulation values Gcyl_OS#i, such that the estimated value Gth_est becomes equal to the TH passing intake air amount, calculates a target inter-intake cam phase ¸ssi#i_cmd, on a cylinder-by-cylinder basis, according to the identified intake air amount variation coefficients ¦#i (step 81), and calculates control input DUTY_ssi#2 to #4 to the variable inter-intake cam phase mechanisms 80 according to the target inter-intake cam phases ¸ssi#i_cmd (step 75).

Description

technical field [0001] The present invention relates to an intake air quantity control system for an internal combustion engine, which controls the respective intake air quantities drawn into a plurality of cylinders. Background technique [0002] Conventionally, as an intake air amount control system for an internal combustion engine, for example, an intake air amount control system described in Patent Document 1 is known. The engine is of a four-cylinder type, and includes: a solenoid valve mechanism provided for each cylinder for changing a valve closing timing relative to a valve opening timing of each cylinder; and a throttle mechanism. As described below, in this intake air amount control system, in order to control the idling speed, the valve closing timing of each intake valve is controlled by a solenoid valve mechanism, thereby controlling the intake air amount. More specifically, the target intake air amount for feedforward control is calculated from the target en...

AI Technical Summary

Problems solved by technology

Therefore, there is a problem that it is not possible to correct for variations in the intake air amount between cylinders

Therefore, in the engine speed control, in a very low load region (eg, idle speed region), rotation variation can be suppressed, but in a normal operation load region, torque due to variation in intake air amount between cylinders changes or rotation changes, thereby deteriorating the combustion state

As a result, drivability and exhaust emission characteristics deteriorate

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