Chrysler Corporation

Daimlerchrysler Corporation

Sandra N Thomson

William B Blomquist

Yi Cheng

Gregory J Dykstra

Brian John Nelson

Patrick T McCourt

A method of controlling a proportional purge solenoid is provided to improve low flow resolution. The method includes looking-up a primary duty cycle corresponding to purge current in a three-dimensional surface by using purge flow and vacuum level as inputs. Should the primary duty cycle fall below a lowest allowable purge current threshold value, a secondary purge duty cycle (i.e., an on/off pattern of the primary duty cycle) is obtained from a two-dimensional table by using the actual calculated purge flow as an input. The two-dimensional table includes a sequence of program loops subdivided into a delay region wherein the purge flow and vacuum level data are learned, an updating region wherein the purge current of the three-dimensional surface is updated, and a control region wherein the primary duty cycle is toggled between on and off states. When the current program loop falls within the delay region, a recorded primary duty cycle is output. When the current program loop falls within the updating region, the primary duty cycle is applied at a time determined during the last program sequence. When the current program loop falls within the control period, the primary duty cycle is applied at a time when the current program loop number equals a program loop number of the two-dimensional surface corresponding to the actual calculated purge flow.

Duty cycling feature for the proportional purge solenoid to improve low

The present invention provides an apparatus for controlling air flow within an internal combustion engine comprising a secondary air passage. The secondary air passage system includes an air inlet channel directing air flow to the air assist valve and an air outlet channel directing air flow from the air assist valve. The air outlet channel communicates with a plurality of fuel injector tips which are disposed within the engine. An air bypass circuit is interposed between the air inlet channel and the air outlet channel to provide an alternate air channel which is independent of the air assist valve. An engine controller electronically communicates with the air assist valve for causing the air assist valve to vary between its open and closed modes.

Bi-modal air assist injection system

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Rochester Hills, MI, United States of America

Sandra N Thomson