| 摘要 |
PURPOSE:To provide a prerotation device for a sequential turbo which prevents the occurrence of stepped phenomenon during switching from a primary turbo to a joint use with a secondary turbo, and is simplified in its structure and excellent in its efficiency. CONSTITUTION:Exhaust gas bypassing the waste gate valve 34 of a primary turbo 23 is fed to a secondary turbo 24 through a piping 35 for prerotation and the secondary turbo 24 is rotated by means of exhaust gas passing a waste gate. For this purpose, the outlet pressure of the primary turbo 23 is increased to a value higher than that of the secondary turbo 24 by means of line resistance itself and an exhaust resistance adding means 38, such as a fixed throttle 40. This constitution prevents lowering of efficiency through utilization of exhaust gas not utilized in the past and simplifies structure in such a way that only the piping 35 for prerotation and the exhaust gas resistance adding means 38 are provided. |
