| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize a stable driving of a variable capacity device regardless of the engine condition, as to a negative pressure actuator to carry out the operation by a negative pressure fed from a negative driving pressure source. SOLUTION: This negative pressure actuator drives a variable capacity device 32 provided at the turbine 21 side of a variable capacity turbocharger, and a first and a second negative pressure chambers 41 and 42 are formed by partitioning the inside by a diaphragm connected to the variable capacity device 32, and the negative pressure actuator is composed by applying a negative driving pressure to both the first and the second negative pressure chambers 41 and 42. When the opening object value of the variable capacity device 32 is set depending on the engine operating condition, this opening target value is set as the pressure difference between the negative pressure of the first negative pressure chamber 41 and the negative pressure value of the second negative pressure chamber 42.</p> |
