Patent ID: 8695338

Claim:
An exhaust gas control apparatus for an engine with a turbocharger comprising: a turbine housing having a turbine accommodating chamber therein: a turbine wheel movably supported in the turbine accommodating chamber and rotated by exhaust gas from the engine; a first passage and a second passage formed in the turbine housing for introducing the exhaust gas from the engine into the wheel accommodating chamber, the first and second passages being formed by dividing an exhaust gas flow-in passage into two passages in a rotational direction of the turbine wheel; a bypass passage formed in the turbine housing so that the exhaust gas from the engine flowing through the bypass passage bypasses the wheel accommodating chamber; a first valve and a second valve, each of which is movably provided in the turbine housing so as to control flow amounts of exhaust gases respectively flowing through the first and second passages and the bypass passage by an opening and/or closing movements of the respective first and second valves; a valve interlocking mechanism having a cam member for interlocking the first and second valves with each other so as to independently open and/or close the first and second valves from each other; and an actuator for driving the first and second valves by way of the cam member, wherein the cam member has a rotational axis rotatably supported by the turbine housing, a first driving portion formed at the rotational axis and directly couple to the first valve so that the first valve is rotated in a synchronized manner with rotation of the cam member, and a second driving portion having a cam groove coupled to the second valve so that the second valve is rotated in accordance with the rotation of the cam member and in an operational pattern different from that of the first valve, and wherein the exhaust gas control apparatus further comprises: a cam angle sensor for detecting a rotational angle of the cam member; a supercharging pressure sensor for detecting a supercharging pressure; and an electronic control unit, configured to estimate respective opening degrees of the first and second valves based on the rotational angle of the cam member detected by the cam angle sensor, set a target supercharging pressure based on the respective opening degrees of the first and second valve, and operate the actuator in order that the supercharging pressure detected by the supercharging pressure sensor is controlled at the target supercharging pressure.