Insulated damped exhaust manifold
OwnerDan T. Moore, IIIinventor
Life of this patent
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Abstract
An exhaust manifold for conducting the heated exhaust gas from an internal combustion engine. The exhaust manifold has a thin noncast metal inner layer, a thicker sheet metal outer layer, and a layer of insulating material, preferably ceramic beads, between the inner and outer layers. The method of making the exhaust manifold is also disclosed. The exhaust manifold is damped, insulated, and permits quicker light off of the catalytic converter.
Claims16
An exhaust manifold for conducting heated exhaust gas from an internal combustion engine to an exhaust system, said exhaust manifold having at least one inlet and at least one outlet, said exhaust manifold comprising an inner layer of noncast metal which defines an exhaust gas passage and a surrounding outer layer of sheet metal and having means associated with said inlet for mounting said exhaust manifold to the head of an internal combustion engine, said outlet being adapted to be connected with said exhaust system, one of said layers having a first predetermined thickness and the other of said layers having a second predetermined thickness substantially different from said first predetermined thickness so that said exhaust manifold is adapted to avoid in-phase resonance, said inner layer being between about 0.006 and about 0.024 inches thick, said inner layer being spaced apart from said outer layer over at least the majority of their adjacent surface areas to form a gap therebetween, and a layer of ceramic beads in said gap.
A method of fabricating an exhaust manifold, said exhaust manifold having at least one inlet and at least one outlet, said method comprising the steps of
- forming from sheet metal a first concave member, a second concave member, a third concave member, and a fourth concave member;
- attaching said first and second concave members to each other to provide an inner layer which defines an exhaust gas passage, said inner layer being between about 0.006 and about 0.024 inches thick;
- providing an outer layer surrounding said inner layer, said outer layer being comprised of said third and fourth concave members attached to each other, one of said layers having a first predetermined thickness and the other of said layers having a second predetermined thickness substantially different from said first predetermined thickness so that said exhaust manifold is adapted to avoid in-phase resonance;
- providing a gap between said inner layer and said outer layer over at least the majority of their adjacent surface areas;
- and
- providing a layer of ceramic beads in said gap.
Dependencies are inferred from the claim text.