Patent ID: 8276372

Claim:
An exhaust emission control device, comprising: a casing incorporated in an exhaust passage; a first post-treatment device, through which exhaust gas flows for cleanup, disposed within the casing, the casing having an outlet connected with a downstream exhaust passage extending in a direction different from an axis of said casing; and an outlet chamber encasing the outlet of the casing in a range to provide spacing to an open end and outer periphery of the outlet of the casing, said outlet chamber intervening between the outlet of the casing and the downstream exhaust passage, wherein a flow cross section of the outlet chamber gradually decreases from the casing outlet to the downstream exhaust passage, whereby the outlet chamber is constructed as an upstream end of a gas gathering chamber for gathering exhaust gas from an outlet of the first post-treatment device, at least a portion of a flow cross section of the outlet chamber is defined by a first annular gap between an outer diameter of the casing and an inner diameter of the outlet chamber, the outer diameter of the casing defines an inner diameter of the first annular gap, and the inner diameter of the outlet chamber defines an outer diameter of the first annular gap.