An exhaust gas heat transfer unit is disclosed having a heat exchanger including a bypass duct, an inflow diffuser with an exhaust gas inlet, and an outflow diffuser with an exhaust gas outlet. The heat exchanger and the bypass duct are assigned a control apparatus which diverts the exhaust gas flow through the heat exchanger and/or the bypass duct.

An exhaust manifold apparatus for routing an exhaust gas produced by an internal combustion engine is described. The manifold includes a manifold log with a log wall that defines a log bore. The log bore is in fluid communication with an upstream opening of the manifold log and a downstream opening of the manifold log. An inlet runner includes a runner wall that defines a runner bore in fluid communication with the log bore. The inlet runner is engaged to the manifold log at a stress point, which also includes at least one stiffening rib disposed on an interior surface of the log wall and/or the inlet runner wall.

The present disclosure provides a method for molding a pipe body that can inexpensively mold a pipe body having a tapered portion radially outwardly projecting relative to a large-diameter portion. The method for molding a pipe body comprises: molding of a tubular body by bending an unfolded stock so as to wrap a core metal; and removal of the core metal from inside the tubular body. The core metal comprises a first core metal piece for molding a projecting portion of the tapered portion. During the molding of the tubular body, the first core metal piece at least partly abuts on an inner surface of the projecting portion of the tapered portion, and does not abut on an area of the inner surface of the large-diameter portion located in an opposite side of a central axis of the large-diameter portion from the projecting portion.

A manifold system for an internal combustion engine, having a housing, which is designed as a collecting manifold and which has two inlet openings and an outlet opening for the flow connection of two outlets of an internal combustion engine to an exhaust system and at most two connection openings provided on the housing for connecting a double-shell inner air-gap-insulated manifold. An exhaust system is developed in such a way that, at the same time, the tone of the exhaust gas noise and thus of the exhaust system is optimized over a plurality of important rotational speed ranges of the internal combustion engine by a modular assembly. For this purpose, at least one separate inner air-gap-insulated manifold having a connection opening, an inlet opening, and an outlet opening is provided, which is connected to the housing by the outlet opening, and at least one separate outer air-gap-insulated manifold having an inlet opening and an outlet opening is connected to the connection opening of the inner air-gap-insulated manifold. All air-gap-insulated manifolds are completely formed of sheet metal, and each air-gap-insulated manifold has a separate one- or multi-part inner shell and a one- or multi-part separate outer shell. All inner air-gap-insulated manifolds are structurally or geometrically identical and all outer air-gap-insulated manifolds are structurally or geometrically identical, wherein the inner air-gap-insulated manifolds are not structurally identical and not geometrically identical to the outer air-gap-insulated manifolds.

An exhaust manifold apparatus for routing an exhaust gas produced by an internal combustion engine is described. The manifold includes a manifold log with a log wall that defines a log bore. The log bore is in fluid communication with an upstream opening of the manifold log and a downstream opening of the manifold log. An inlet runner includes a runner wall that defines a runner bore in fluid communication with the log bore. The inlet runner is engaged to the manifold log at a stress point, which also includes at least one stiffening rib disposed on an interior surface of the log wall and/or the inlet runner wall.

An exhaust manifold apparatus for routing an exhaust gas produced by an internal combustion engine is described. The manifold includes a manifold log with a log wall that defines a log bore. The log bore is in fluid communication with an upstream opening of the manifold log and a downstream opening of the manifold log. An inlet runner includes a runner wall that defines a runner bore in fluid communication with the log bore. The inlet runner is engaged to the manifold log at a stress point, which also includes at least one stiffening rib disposed on an interior surface of the log wall and/or the inlet runner wall.

A manifold system for an internal combustion engine, having a housing, which is designed as a collecting manifold and which has two inlet openings and an outlet opening for the flow connection of two outlets of an internal combustion engine to an exhaust system and at most two connection openings provided on the housing for connecting a double-shell inner air-gap-insulated manifold. An exhaust system is developed in such a way that, at the same time, the tone of the exhaust gas noise and thus of the exhaust system is optimized over a plurality of important rotational speed ranges of the internal combustion engine by a modular assembly. For this purpose, at least one separate inner air-gap-insulated manifold having a connection opening, an inlet opening, and an outlet opening is provided, which is connected to the housing by the outlet opening, and at least one separate outer air-gap-insulated manifold having an inlet opening and an outlet opening is connected to the connection opening of the inner air-gap-insulated manifold. All air-gap-insulated manifolds are completely formed of sheet metal, and each air-gap-insulated manifold has a separate one- or multi-part inner shell and a one- or multi-part separate outer shell. All inner air-gap-insulated manifolds are structurally or geometrically identical and all outer air-gap-insulated manifolds are structurally or geometrically identical, wherein the inner air-gap-insulated manifolds are not structurally identical and not geometrically identical to the outer air-gap-insulated manifolds.

The present disclosure provides a method for molding a pipe body that can inexpensively mold a pipe body having a tapered portion radially outwardly projecting relative to a large-diameter portion. The method for molding a pipe body comprises: molding of a tubular body by bending an unfolded stock so as to wrap a core metal; and removal of the core metal from inside the tubular body. The core metal comprises a first core metal piece for molding a projecting portion of the tapered portion. During the molding of the tubular body, the first core metal piece at least partly abuts on an inner surface of the projecting portion of the tapered portion, and does not abut on an area of the inner surface of the large-diameter portion located in an opposite side of a central axis of the large-diameter portion from the projecting portion.

An exhaust manifold apparatus for routing an exhaust gas produced by an internal combustion engine is described. The manifold includes a manifold log with a log wall that defines a log bore. The log bore is in fluid communication with an upstream opening of the manifold log and a downstream opening of the manifold log. An inlet runner includes a runner wall that defines a runner bore in fluid communication with the log bore. The inlet runner is engaged to the manifold log at a stress point, which also includes at least one stiffening rib disposed on an interior surface of the log wall and/or the inlet runner wall.

An assembly unit 1 of an exhaust system has at least one and particularly two connection funnels 2 made of cast material and a pipe 3. The at least one connection funnel 2 has a pipe socket 21 and at least one bracket 22. The bracket 22 is arranged outside of the pipe socket 21. A connection section 31 of the pipe 3 is fastened to the bracket 22 of the at least one connection funnel. The pipe socket 21 extends beyond the connection section 31 of the pipe 3 into the interior of the pipe 3 and is spaced apart from an inner wall of the pipe 3 by at least the simple wall thickness of the pipe 3.