Control of idle revolution number of internal- combustion engine

Abstract

Abstract PURPOSE:To suppress sharp variation of the number of revolution by reducing the integration term in the feedback control to perform a slow control when an engine is cold in feedback-controlling the idle revolution number by controlling the flow-rate of the intake air which detours around a throttle valve. CONSTITUTION:An idle revolution speed controlling valve 26 is interposed in a by-pass passage 24 which is installed so as to detour a throttle valve 18 in an intake passage, and is controlled during idle operation according to the difference between the engine revolution number which is obtained from the output from a crank angle sensor 44 and the aimed idle revolution number by a digital control circuit 54. When it is detected in the control circuit 54 that a feedback condition is satisfied from the cold engine state, the integration term in feedback control is set to a less value during a prescribed time from the start of the feedback control. Thus, the number of revolution is reduced slowly in the slow control and sharp variation of the number of revolution is suppressed.

Inventors

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

Bibliographic Details