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US 7,581,563 B2Granted
Exhaust pipe with profiled inner tube, and method of making an exhaust pipe
AssigneeBenteler Automobiltechnik GmbH
InventorChristian Smatloch
Life of this patent
Estimating the term…
Abstract
An exhaust pipe for an internal combustion engine includes an inner tube carrying a flow of exhaust gas and surrounded by an outer tube, with an insulating layer disposed between the inner tube and the outer tube. The inner tube has at least one region formed with a nub-shaped profile in contact with the flow of exhaust gas.
Claims16
An exhaust pipe for an internal combustion engine, comprising:
- an inner tube carrying a flow of exhaust gas, said inner tube having at least one region formed with a nub-shaped profile in contact with the flow of exhaust gas, wherein the profile has a wave-like configuration defined by wave troughs and wave crests, with the wave troughs and wave crests placed in offset relationship in at least one direction selected from the group consisting of circumferential direction and longitudinal direction, wherein an amplitude between the wave troughs and wave crests is smaller than or equal to 5 times a wall thickness of the inner tube;
- an outer tube in spaced-apart surrounding relationship to the inner tube;
- and
- an insulating layer disposed between the inner tube and the outer tube.
1 more element
A method of making an exhaust pipe, comprising the steps of:
- profiling a sheet metal blank with wave crests and wave troughs in offset relationship in transverse direction and in longitudinal direction and with an amplitude between the wave troughs and wave crests being smaller than or equal to 5 times a wall thickness of the sheet metal blank;
- shaping the sheet metal blank into a tubular member or to half-shells;
- connecting longitudinal edges of the tubular member or half-shells through interlocking engagement or material union;
- enclosing the tubular member with an insulating layer to produce an ensheathed tube;
- placing the ensheathed tube as an inner tube within an outer tube;
- jointly bending the inner tube and the outer tube to form a structure;
- and
- connecting the structure to attachment components.
5 more elements
Dependencies are inferred from the claim text.