| 摘要 |
1299310 Recycling exhaust gas FORD MOTOR CO Ltd 25 May 1971 [27 July 1970] 16827/71 Heading F1B An I. C. engine has a recirculating valve in a passage between an exhaust means and an intake means, the valve member being controlled by a cam in a housing and a vacuum motor, attached to the cam, responding to intake manifold pressure to move the cam along one axis and linkage means connected with a throttle in the engine intake for rotating the cam about the axis in response to the position of the throttle means. Exhaust gas from exhaust pipe 32 passes through a chamber 28, which is traversed by conduits 34, 36 carrying engine coolant, and through an orifice 44, controlled by a valve 48, into a chamber 26. Engine crank-case gases also enter chamber 26 and the gases pass via passage 52 into a carburetter 12 downstream of throttle valve 18. At starting and warm-up recirculation is ineffective in reducing pollution so that, under these conditions a temperature responsive valve 68 connects vacuum chamber 66 to atmosphere permitting spring 70 to position cam 60 to close valve 48. At higher temperatures valve 68 connects chamber 66 to the intake manifold 10 to position cam 60 as shown. During idling the closed throttle 18 rotates cam 60 to close valve 48. At small accelerations the throttle movement and rising manifold pressure moves the cam to a position where valve 48 opens to provide some recirculation and at greater accelerations the rising manifold pressure progressively reduces the recirculation. |
