Abstract: Throttle valves are individually disposed in a plurality of intake passages of an engine. In normal operation condition of the throttle valves, a first control device controls the throttle valves according to the detection result of an operation condition detecting device to control the amounts of intake air of the individual intake passages, thereby obtaining good engine performance from low-speed to high-speed ranges. When an abnormality detecting device detects an abnormality in a throttle valve, a determination device determines a normal throttle valve, and a second control device controls only the normal throttle valve in preference to the first control device to control the intake air amount, thereby ensuring continued operation even if a malfunction occurs in one of the throttle valves.

Abstract: A direct injection-type diesel engine includes a piston head formed with a novel piston combustion chamber, with an inner wall surface composed essentially of ceramic material having a low thermal conductivity. The combustion chamber has a reduced opening diameter to enhance a squish air flow out of the clearance space between the piston and the cylinder head, and allows significant reduction of smoke, unburnt hydrocarbon and particulates in the exhaust gas, as well as minimization of thermal loss of the engine.

Abstract: A variable-volume turbocharger device comprises at least two exhaust gas passages (A), (B) different in the flow characteristics, divided by a partition wall (20) provided in a turbine housing (18), and two valve members (34a), (34b) which are actuated so as to open and shut the exhaust gas passages (A), (B). The valve members (34a), (34b) each are actuated to open and shut in response to the speed and load of an engine or the likes, whereby either one of the exhaust gas passages (A), (B) or both of them are opened to provide at least three turbine flow characteristics. An exhaust gas turbine (12) can be thereby operated with remarkably good efficiency suitably to the operating state of the engine.

Abstract: A variable-volume turbocharger device comprises at least two exhaust gas passages (A), (B) different in the flow characteristics, divided by a partition wall (20) provided in a turbine housing (18), and two valve members (34a), (34b) which are actuated so as to open and shut the exhaust gas passages (A), (B). The valve members (34a), (34b) each are actuated to open and shut in response to the speed and load of an engine or the likes, whereby either one of the exhaust gas passages (A), (B) or both of them are opened to provide at least three turbine flow characteristics. An exhaust gas turbine (12) can be thereby operated with remarkably good efficiency suitably to the operating state of the engine.