Patent ID: 7748216
Filing Date: 2010-07-06
Classification: F01N,F02B,Y02T

Abstract:
1. An internal combustion engine comprising: a turbocharger having a turbine disposed on an exhaust passage; an air-fuel ratio sensor including an element for contacting an exhaust gas, the air-fuel ratio sensor being disposed downstream of and in proximity to the turbine with the element positioned on or near an axis of an exhaust port of the turbine; and a bypass passage for allowing the exhaust gas to bypass a turbine wheel of the turbine, wherein: an outlet of the bypass passage opens into a part of the exhaust passage between the exhaust port and the air-fuel ratio sensor in a direction tangent to the circumference of the exhaust passage, a part of the exhaust passage between the exhaust port and the air-fuel ratio sensor is formed with a recess depressed outward in a radial direction of the exhaust passage, the recess is a groove along the circumference of the exhaust passage, and the groove is a spiral groove extending from a predetermined position between the exhaust port and the air-fuel ratio sensor to a predetermined position downstream of the air-fuel ratio sensor.