초록

A control actuator for a turbocharger comprises a pressure responsive diaphragm for controlling operation of a turbocharger waste gate valve in response to compressor inlet pressure during part load engine operation, and in response to tubine inlet pressure during full load engine operation.

대표청구항 ▼

In a turbocharged engine system having an engine, a turbine driven by engine exhaust gases, a compressor driven by the turbine to draw in air for supply to the engine, means forming a bypass flow path for bypass passage of exhaust gases around the turbine, and a waste gate valve for opening and clos

In a turbocharged engine system having an engine, a turbine driven by engine exhaust gases, a compressor driven by the turbine to draw in air for supply to the engine, means forming a bypass flow path for bypass passage of exhaust gases around the turbine, and a waste gate valve for opening and closing the bypass flow path, a turbocharger control actuator, comprising: an actuator housing; a flexible diaphragm mounted with said housing and cooperating therewith to define a pressure chamber; an actuator rod having one end for connection to the waste gate valve to control the position thereof, and its other end movably carried with said diaphragm; spring means for urging said actuator rod to retain the waste gate valve in a position closing the bypass flow path; and means for supplying a first control pressure to said pressure chamber at part load engine operating conditions, said first control pressure having a magnitude for causing movement of said diaphragm to displace said actuator rod for moving the waste gate valve against said spring means to a position opening the bypass flow path, said supplying means further including switch means for substantially disconnecting said first control pressure from said pressure chamber at substantially full load engine operating conditions and for supplying a second control pressure to said pressure chamber, said second control pressure having a magnitude for causing movement of said diaphragm to displace said actuator rod for moving the waste gate valve to a position closing the bypass flow path, said switch means coupling said pressure chamber to the intake of the compressor during part load engine operating conditions, and coupling said pressure chamber to ambient pressure at substantially full load engine operating conditions.