Patent ID: 9194341
Filing Date: 2015-11-24
Classification: F02B,F02M,Y02T

Abstract:
1. A multistage turbocharging system comprising: a first turbocharger including a low-pressure stage compressor and a low-pressure stage turbine and configured to be supplied with exhaust gas discharged from an internal combustion engine; a second turbocharger including a high-pressure stage compressor and a high-pressure stage turbine and configured to be arranged more on the upstream in the flow of the exhaust gas than the first turbocharger; and an exhaust bypass valve device provided with a valve assembly including a valve body and a washer and configured to perform opening and closing of a bypass flow passage that supplies the exhaust gas discharged from the internal combustion engine to the first turbocharger by bypassing the turbine impeller of the second turbocharger, the valve body being configured to open and close an opening of the bypass flow passage, the washer being configured to fix the valve body to a mounting portion coupled via a shaft portion; wherein the thickness of at least either one of the valve body and the washer being set to be greater than the minimum width of a flow passage from the valve assembly to the turbine impeller of the first turbocharger, and wherein the minimum width of the flow passage is located to prevent either the valve body or the washer from reaching the turbine impeller of the first turbocharger.