Patent ID: 7430856
Filing Date: 2008-10-07
Classification: F01N,F02B,Y02T

Abstract:
1. A pressure detection mechanism, provided in an exhaust emission control device for an internal combustion engine, wherein the exhaust emission control device includes an N amount of catalytic elements, N being an integer of 2 or more, and the catalytic elements are arranged in series from a first catalytic element to the Nth catalytic element oriented from upstream close to the internal combustion engine to downstream comprising: an upstream pressure detection portion provided in a space between the first catalytic element and an Mth catalytic element, M being an integer of 2 or more equal to or less than N; a downstream pressure detection portion provided downstream of the Mth catalytic element, wherein blockage of the Mth catalytic element is detected based on a pressure detected by the upstream pressure portion and a pressure detected by the downstream pressure detection portion; and a controller; wherein at least one catalytic element provided upstream of the upstream pressure detection portion is a NOx storage reduction catalytic element; wherein the upstream pressure detection portion is provided in a space between an M-1th catalytic element and the Mth catalytic element; and wherein said at least one catalytic element provided upstream of the upstream pressure detection portion is in constant communication with exhaust gas from the internal combustion engine.