Apparatus for controlling the idling operation of an internal combustion engine

Claim 1

An apparatus for controlling the idling operation of an internal combustion engine having a closed-loop control system for controlling the amount of fuel to be supplied to a multi-cylinder internal combustion engine so as to maintain the average engine speed of the internal combustion engine at a desired target idling rotational speed, the output torque produced during the power stroke of a cylinder of said engine being influenced by the output torque of another cylinder, said apparatus comprising: a first detecting means for detecting the operation timing of the internal combustion engine; a second detecting means for producing a timing signal for determining a predetermined measurement period for each cylinder which includes that part of the combustion period during which torque is produced due to fuel combustion in a cylinder concerned during which no influence arises because of torque produced in cylinders other than the specific cylinder concerned, and only a portion of that part of the combustion period during which there is said influence because of torque produced in another cylinder such that said predetermined measurement period corresponds substantially to the minimum points of the instantaneous crankshaft speed associated with the specific cylinder concerned; a first calculating means responsive to the timing signal for calculating and producing a first data related to the output from each cylinder of the internal combustion engine; a second calculating means responsive to the first data for sequentially and repeatedly calculating and producing for every cylinder a difference data corresponding to the difference between the output from each cylinder and the output from a predetermined reference cylinder among the cylinders; a third calculating means responsive to the difference data for calculating and producing an individual cylinder control data related to the supply of fuel necessary for reducing to zero the difference shown by the difference data; an output control means for outputting the individual cylinder control data at a predetermined timing before the next fuel regulating process for the individual cylinders on the basis of the result of the detection in the first detecting means; and an adding means for supplying the individual cylinder control data to the closed-loop control system.

Claim 2

An apparatus for controlling the idling operation of an internal combustion engine having a closed-loop control system for controlling the amount of fuel to be supplied to a multi-cylinder internal combustion engine so as to maintain the average engine speed of the internal combustion engine at a desired target idling rotational speed, the output torque produced during the power stroke of a cylinder of said engine being influenced by the output torque of another cylinder, said apparatus comprising: a first detecting means for detecting the operation timing of the internal combustion engine; a second detecting means for producing a timing signal for determining a predetermined measurement period for each cylinder which includes that part of the combustion period during which torque is produced due to fuel combustion in a cylinder concerned during which no influence arises because of torque produced in cylinders other than the specific cylinder concerned, and only a portion of that part of the combustion period during which there is said influence because of torque produced in another cylinder such that said predetermined measurement period corresponds substantially to the minimum points of the instantaneous crankshaft speed associated with the specific cylinder concerned; a first calculating means responsive to the timing signal for calculating and producing a first data related to the output from each cylinder of the internal combustion engine; a second calculating means responsive to the first data for sequentially and repeatedly calculating and producing for every cylinder a difference data corresponding to the difference between the output from each cylinder and the output from a predetermined reference cylinder among the cylinders; a third calculating means responsive to the difference data for calculating and producing an individual cylinder control data related to the supply of fuel necessary for reducing to zero the difference shown by the difference data; an output control means for outputting the individual cylinder control data at a predetermined timing before the next fuel regulating process for the individual cylinders on the basis of the result of the detection in the first detecting means; and an adding means for supplying the individual cylinder control data to the closed-loop control system.