Air gap-insulated exhaust elbow

Abstract

The present invention relates to an air gap-insulated exhaust elbow of an internal combustion engine in a motor vehicle and a manufacturing method thereof. The exhaust elbow includes an internal element and an external element, wherein the internal element has at least two tubular hollow bodies made of plates, the hollow bodies are connected to each other in a movable manner, the external elementis separated from the internal element by an air gap, and the external element is configured as a monolithic casting, and there is no direct contact between the internal element and the external element.

Description

technical field [0001] The invention relates to an air-gap insulated exhaust elbow for an internal combustion engine in a motor vehicle, comprising an inner element and an outer element, wherein the inner element has at least two tubular hollow bodies made of plastic, wherein the hollow bodies are movably connected to one another, wherein the outer element is separated from the inner element by an air gap, wherein the outer element is formed as a one-piece cast part. Background technique [0002] The tubes in the exhaust manifold are subjected to a great thermal load, especially in gasoline motors, since the exhaust gases flowing through the exhaust manifold can have temperatures in excess of 1050° C. Air-gap-insulated exhaust manifolds are therefore known from the prior art, which are usually welded together from a plurality of high-alloy sheet parts, so that such exhaust manifolds are expensive in terms of their production costs. [0003] WO 2006 / 097187 discloses such an ...

AI Technical Summary

Problems solved by technology

The prerequisite for this concept is that the casting materials used are able to withstand the high demands and therefore high-quality, correspondingly expensive casting materials must also be used

[0006] If the solutions known from the prior art are to meet the temperature requirements for gasoline motors, these solutions are correspondingly expensive either due to the high-alloy steel castings that have to be used or due to the time-consuming welding of sheet-metal structures

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