| 摘要 |
PURPOSE:To prevent overrun of turbochargers or an abnormal increase of a pressure at a turbine inlet by forcibly opening an exhaust changeover valve which operates changeover valve under an unloaded racing condition of an engine. CONSTITUTION:A pressure chamber of a driving means 81 is connected to an intake passage part 14a of a throttle valve 18 on a downstream side of a compressor of turbochargers, through a changeover means 82 for pressure introduced into a driving means 81 and a holding means 83 against a compressor discharge maximum value of introduced pressure, which driving means 81 openes or closes an exhaust changeover valve 18 for operating and stopping the turbochargers 7, 8. A detecting means 84 detects an unloaded racing condition of the engine 1. When judgement means 85 detects the condition, a performing means 86 forcibly openes the exhaust changeover valve 17. Overrun etc. of the turbochargers are prevented accordingly. |
