Diesel throttle valve control system - has intake passage in series with air intake manifold, and has temp. sensing vacuum cut=off and negative pressure control valves

摘要

The intake air throttle valve control system for a diesel engine greatly reduces vibration and noise and rough engine running at idling speeds. There is a throttle valve (1) in an intake passage (5) in series with the intake air manifold of the engine with the valve operated by a negative pressure responsive actuator (6) coupled to a source of negative pressure through a series-connected arrangement of a water temperature sensing valve (25), a vacuum cut-off valve (15) and a negative pressure control valve (26), the water temperature sensing valve operating to connect or disconnect the source of negative pressure to the actuator (6) in response to the temperature of the engine coolant. The vacuum cut-off valve (15) vents the connections to the actuator (6) to the atmosphere in response to an engine operating parameter such as the exhaust manifold pressure, the pressure in an oil line of the engine, or an output voltage of a generator which varies in response to the engine speed and the negative pressure control valve (26) introducing atmospheric pressure into the system in proportion to the magnitude of negative pressure in the intake manifold (5a) downstream of the throttle valve (1).