Dual wall exhaust manifold and method of making same

Abstract

The present invention provides an improved dual-wall exhaust manifold assembly. The assembly has inner shells welded together and welded to an inlet flange. Outer shells are inserted into a counterbore of the inlet flange. An outlet flange is slid over the inner shell. The inner shell and the outer shell are inserted into the counterbore of the outlet flange. The outer shells are welded together and to the outlet and inlet flanges. The inlet counterbore and the outlet flange counterbore separate the inner and outer shells.

Description

RELATED APPLICATIONS [0001] This non-provisional application claims the benefit of U.S. Provisional Patent Application No. 60 / 756,238, entitled “DUAL WALL EXHAUST MANIFOLD,” filed Jan. 3, 2005, which is hereby incorporated by reference in its entirety.FIELD OF ART [0002] The present invention relates generally to exhaust manifolds, and more specifically, to dual-wall exhaust manifolds for use with internal combustion engines. BACKGROUND OF THE INVENTION [0003] Many modern high performance engines generate extremely hot gas emissions. As these emissions are expelled from the engine and pass through the exhaust manifold, the hot emissions heat the exhaust manifold or pipes to increasingly high temperatures. Such high temperatures cause the temperature of the tubes to elevate resulting in discoloration of the tubes. As such, some component designs utilize a dual wall construction that utilizes an air gap between the inner and outer tubes. Known dual wall manifolds utilize spacers and s...

AI Technical Summary

Benefits of technology

[0008] A dual wall exhaust manifold assembly is provided. The manifold has an outer shell and an inner shell spaced apart to allow for an air gap between the shells. To ease in manufacture and assembly, the inlet flange and the outlet flange have counterbores. The counterbore of the outlet flange aids in spacing the inner shell and the outer shell. The inner shell is connected to the outlet flange with a slip fit joint. The counterbore of the outlet flange provides an area to weld the outer shell to the outlet flange. The counterbore of the inlet flange allows space for welding the inner shell to the inlet flange. Advantageously, the manifold assembly of the present invention eliminates components typically required for manufacture of a dual wall exhaust manifold, such as stub tubes and spacers.

Problems solved by technology

Many modern high performance engines generate extremely hot gas emissions.

As these emissions are expelled from the engine and pass through the exhaust manifold, the hot emissions heat the exhaust manifold or pipes to increasingly high temperatures.

Such high temperatures cause the temperature of the tubes to elevate resulting in discoloration of the tubes.

However, use of stub tubes, spacers and the related labor associated with these components is costly.

Furthermore, manufacturing costs of a manifold assembly can be significant, and a continual need in the industry is to reduce these manufacturing costs.

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