Patent ID: 8763384

Claim:
An exhaust gas apparatus of an internal combustion engine, provided with an exhaust gas pipe at the downstream side of an internal combustion engine in the exhaust gas direction of an exhaust gas flow, the exhaust gas pipe having an upstream opening end at one end portion thereof and connected with a sound deadening device at the upstream side in the exhaust gas direction of the exhaust gas flow, and a downstream opening end at the other end portion thereof for exhausting the exhaust gas flow to the atmosphere, the exhaust gas apparatus comprises; a valve body having a swing shaft connected with the exhaust gas pipe to perpendicularly extend with respect to the center axis of the exhaust gas pipe and to be positioned outwardly of the center axis of the exhaust gas pipe and spaced apart from the center axis of the exhaust gas pipe, the valve body being adapted to receive only the exhaust gas flow flowing in the exhaust gas pipe and to be swingable around the center axis of the swing shaft to allow the passage cross-sectional area of the exhaust gas pipe to be varied, in which the valve body is formed with a pair of guide portions at the both widthwise end portions of the valve body perpendicularly extending to the center axis of the exhaust gas pipe, the guide portions projecting from the both widthwise end portions of the valve body toward the downstream side of the exhaust gas direction of the exhaust gas flow, and a throttle unit for throttling the passage cross-sectional area of the exhaust gas pipe to a predetermined passage cross-sectional area when the valve body receives the flow amount of the exhaust gas flow flowing in the exhaust gas pipe in response to the operation state of the internal combustion engine to be swung around the center axis of the swing shaft in the case of an air column resonance being generated in the exhaust gas pipe, in which the throttle unit is constituted by at least part of a projection portion provided at the lower end portion of the valve body to project from the lower end portion of the valve body toward the downstream side of the exhaust gas direction of the exhaust gas flow.