| 摘要 |
<p>PURPOSE:To obtain an always proper supercharge pressure corresponding to the engine operation state by open-controlling a pressure adjusting valve for the pressurized air which acts into the pressure chamber of the actuator for a waste gate valve by each duty value set in a plurality of engine operation regions. CONSTITUTION:In an exhaust turbosupercharger 4, a bypass passage 24 which makes a detour around an exhaust turbine 8 is formed in an exhaust passage 12, and the inlet 26 is opened and closed by a waste gate valve 30. The waste gate valve 30 is driven by an actuator 32 including a diaphragm 36 which divides an atmosphere chamber 40 and a pressure chamber 38 into which the supercharge pressure in an intake passage 10-2 on the downstream side of a compressor 6 is introduced through a pressure introducing passage 48. In this case, the middle part of the pressure introducing passage 48 is allowed to com municate to an intake passage 10-1 on the upstream side of the compressor through a pressure controlling passage 52 having a pressure control valve 54 interposed, and the pressure control valve 54 is open-controlled according to each duty valve set in a plurality of engine operation regions.</p> |
