Method of controlling recirculation of exhaust gas of internal-combustion engine

Abstract

Abstract PURPOSE:To prevent NOx from being exhausted in large amount during warming-up, by recirculating the exhaust gas from the starting of the warming-up till a prescribed period has passed after air-fuel ratio feedback control is started by an exhaust gas sensor. CONSTITUTION:A controller 70 into which values detected by an intake air amount sensor 19, a rotational angle sensor 65, a water temperature sensor 63, an O2 sensor 64, etc. are inputted controls the time during which a fuel jetting valve 70 is opened and also controls to open or close a negative pressure control valve 49 for introducing negative pressure into an exhaust gas recirculation amount controlling diaphragm apparatus 42. The controller 70 after it is started starts fuel amount feedback control to a theoretical air-fuel ratio that is based on the value detected by the O2 sensor when the temperature of cooling water is for example 50 deg.C or above, but it opens the negative pressure control valve 49 to recirculate the exhaust gas when the time from the starting thereof to the start of the controlling of the feedback is within a prescribed period, the temperature of the cooling water is for example 20 deg.C or above, the rotational frequency is, for example, 1,800-2,800rpm, and the intake of air is within a prescribed range.

Inventors

• 👤 Yoshiyasu Ito
• 👤 嘉康 伊藤
• 👤 Yuji Takeda
• 👤 武田　勇二
• 👤 Toshio Suematsu
• 👤 末松　敏男

Bibliographic Details