Abstract: An exhaust gas recirculation (EGR) cooler for a vehicle may include an intake pipe through which EGR gas flows; a core unit having an inlet connected to the intake pipe and may have a plurality of channels into which EGR gas flows through the intake pipe; a cooler housing that covers the core unit and through which cooling water flows to cool the cover unit; and a water jacket that covers the intake pipe, is connected to the cooler housing, and through which the cooling water flows to cool the intake pipe.

Abstract: A two-stage turbocharger apparatus includes first and second passages having different cross-sectional areas. The first and second passages are connected to an inlet end of a high-pressure turbine and are configured to supply exhaust gas discharged from an exhaust manifold of an engine to the inlet end of the high-pressure turbine. Third and fourth passages, having different cross-sectional areas, connect an outlet end of the high-pressure turbine to an inlet end of a low-pressure turbine. An EGR valve has one end connected to one of the first and second passages. A bypass line has a first end connected to the other of the first and second passages and a second end connected to one of the third and fourth passages.

Abstract: A bypass valve device of a multistage turbocharger may include a guide arm adjacently disposed at an inlet of a bypass passage and having a first end rotatably mounted through a rotating shaft, and an opening and closing valve freely rotatably coupled to a second end of the guide arm, having a valve surface which covers a cross section of the inlet, and configured to rotate at the guide arm at a time of contacting the inlet so that the valve surface face-contacts the cross section of the inlet.

Abstract: A two-stage turbocharger apparatus includes first and second passages having different cross-sectional areas. The first and second passages are connected to an inlet end of a high-pressure turbine and are configured to supply exhaust gas discharged from an exhaust manifold of an engine to the inlet end of the high-pressure turbine. Third and fourth passages, having different cross-sectional areas, connect an outlet end of the high-pressure turbine to an inlet end of a low-pressure turbine. An EGR valve has one end connected to one of the first and second passages. A bypass line has a first end connected to the other of the first and second passages and a second end connected to one of the third and fourth passages.