JPS5677542A - Device for controlling recirculation of exhaust gas - Google Patents

Abstract

PURPOSE: To enable to recirculate exhaust gas always at a rate appropriate to the rate of intake- air flow independently of the level of partial vacuum developed in the intake pipe, by providing a valve for controlling the velocity of introduction of atmospheric air, which is capable of correcting the velocity of introducing atmospheric air into a vacuum introducing conduit via a vacuum controlling valve in response to the level of partial vacuum developed at the venturi.

CONSTITUTION: When a throttle valve 5 is opened to a position above a vacuum port 15, suction vacuum is introduced via a conduit 16 into a vacuum chamber 13 of an EGR control valve 7, so that a valve element 9 is moved upward together with a diaphragm 12. Resultantly, a valve port 8 is opened and pressure in a pressure chamber 18 defined in an EGR passage 6 by an orifice element 17 is raised. When this pressure in pressure chamber 18 is raised above a predetermined value, a valve element 21 of a vacuum control valve 19 is moved to the left together with a diaphragm 24, so that a valve port 20 is opened. Resultantly, atmospheric air is introduced into conduit 16 via a valve 28 for controlling the velocity of introduction of atmospheric air, which causes movement of valve element 9 to the valve closing direction, so that the amount of recirculated exhaust gas can be kept constant. Here, the control valve 28 is designed to be controlled by a diaphragm means 37 in response to the venturi vacuum.

COPYRIGHT: (C)1981,JPO&Japio