Outer tube of exhaust system part

Abstract

An outer tube of an exhaust system part, wherein a sheet metal material is rolled double to form it in a cylindrical shape having an inner sheet (2) and an outer sheet (3), and the circumferential end parts (2a) and (3a) thereof are crossed each other in the circumferential direction to form an overlapped portion (4). A plurality of line grooves (5) are formed between the inner sheet (2) and the outer sheet (3) so that the tip parts thereof are opposed to each other through a prescribed distance with respect to the peripheral end part of one of the inner sheet (2) and the outer sheet (3) and projected to the outside of the outer tube (1). The line grooves (5) are disposed parallel with each other along the longitudinal direction of the outer sheet (3) to form a plurality of peripheral communication passages (p). The inner and outer sheets are joined to each other at parts of the overlapped portion positioned between the adjacent line grooves (5) by welding (W).

Description

technical field [0001] The present invention relates to an outer cylinder of an exhaust system component, for example, to an outer cylinder of a muffler or an exhaust purification device. Background technique [0002] In the exhaust system of automobiles equipped with internal combustion engines, exhaust system components such as mufflers for reducing exhaust noise or exhaust purification devices for purifying exhaust gas are arranged. In order to suppress radiated sound, these exhaust system components generally use an outer cylinder formed in two or more layers. For example, in the following Patent Document 1, it is disclosed that a plate is wound around the end plate and the separator to form a cylindrical outer cylinder, and the plate is welded to the outer peripheral flanges of the end plate and the separator by laser welding from the outside of the outer cylinder. silencer. [0003] In addition, in the following Patent Document 2, there is proposed a muffler for an i...

AI Technical Summary

Problems solved by technology

However, the discharge of water vapor and the prevention of water intrusion are contradictory. As described in the above-mentioned patent document 2, although the water vapor can be discharged by using the drain channel and the through hole, the condensed water is allowed to enter the drain channel because it communicates with the inside of the muffler. Inner, that is, damage the waterproof effect of the diameter direction of the outer cylinder, and cause the accumulation of condensed water

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