JPS57151033A - Exhaust gas recirculating device of engine - Google Patents

Abstract

PURPOSE:To obtain smooth acceleration in an exhaust gas recirculating device, operating a recirculating valve controller and air-fuel ratio regulating valve at accelerating operation, by delaying operation of the controller from operation of the regulating valve. CONSTITUTION:If a throttle valve 6 is rapidly opened at acceleration, the atmospheric pressure in the upstream acts on the first pressure chamber 18a, simultaneously a check valve 18d is closed, and a passage 19 is closed by a valve member 18c with negative pressure in the second pressure chamber 18b, then the negative pressure in the chamber 18b is leaked to the atmosphere from a valve 18f, with delay of a certain time, the valve member 18c is opened to release the passage to the atmosphere. Accordingly, at acceleration, intake negative pressure is applied to a passage 15 and to negative pressure chambers in valves 13, 16 via passages 14, 17, and flowing air from the valve 13 to a pressure regulating chamber 12a is stopped to increase negative pressure and increase the opening of an exhaust gas recirculating valve 9, then an air amount from the valve 16 to an air bleed device 4 is decreased, thus a fuel amount delivered from a nozzle 3 is increased. Here the spring constant of a spring 13h is higher than 16h, and this causes close timing of the valve 13 to be delayed from 16, then a recirculating amount is never increased before increase of a fuel amount.