US 2008/0189026 A1 · Intake air control of an internal combustion engine

Abstract

The present invention provides an intake air control capable of implementing a highly accurate constant negative pressure control with a smaller number of process steps under various environments. The intake air control is applicable to an engine having a variable valve actuation mechanism for adjusting at least a lift amount of an intake valve to control an intake air amount and a throttle valve for keeping a gauge pressure in an intake manifold at a desired gauge pressure. A reference throttle opening area is determined by referring to a first table based on a desired intake air amount. The first table defines a relation between an intake air amount and a throttle opening area under a reference gauge pressure, a reference atmospheric pressure and a reference intake air temperature. A throttle opening area for achieving the desired gauge pressure is determined by correcting the reference throttle opening area with a correction parameter derived based on the Bernoulli's law by using the desired gauge pressure, a current atmospheric pressure and a current intake air temperature.

Claims33

Dependent claims

An intake air controlling apparatus of an internal combustion engine having a variable valve actuation mechanism for adjusting at least a lift amount of an intake valve to control an intake air amount and a throttle valve for keeping a gauge pressure in an intake manifold at a predetermined desired gauge pressure, the apparatus comprising:

means for determining a reference throttle opening area by referring to a first table based on a desired intake air amount, the first table defining a relation between an intake air amount and a throttle opening area under a reference gauge pressure, a reference atmospheric pressure and a reference intake air temperature;
and
means for determining a throttle opening area for achieving the desired gauge pressure by correcting the determined reference throttle opening area with a correction parameter that is derived based on the Bernoulli's law using the desired gauge pressure, a current atmospheric pressure and a current intake air temperature.

A computer program embodied on a computer readable medium for controlling an intake air of an internal combustion engine having a variable valve actuation mechanism for adjusting at least a lift amount of an intake valve to control an intake air amount and a throttle valve for keeping a gauge pressure in an intake manifold at a predetermined desired gauge pressure, comprising the steps of:

determining a reference throttle opening area by referring to a first table based on a desired intake air amount, the first table defining a relation between an intake air amount and a throttle opening area under a reference gauge pressure, a reference atmospheric pressure and a reference intake air temperature;
and
determining a throttle opening area for achieving the desired gauge pressure by correcting the determined reference throttle opening area with a correction parameter that is derived based on the Bernoulli's law using the desired gauge pressure, a current atmospheric pressure and a current intake air temperature.

Dependencies are inferred from the claim text.

Intake air control of an internal combustion engine

Life of this patent

Intake air control of an internal combustion engine

Life of this patent

Abstract

Claims33