Method for making catalytic converters with automated substrate crack detection

Abstract

A method for making catalytic converters with automated crack detection includes forming a rigid housing, providing a substrate shaped for reception in the housing, and forming a mat shaped to cover the exterior surface of the substrate and having a thickness which creates a tight friction fit between the substrate and the housing when the same are assembled. The mat is wrapped around the substrate, and the wrapped substrate is then stuffed into the housing using a reciprocating ram or the like that extends at a relatively constant speed. The stuffing force and the ram position are measured and recorded regularly to define an array of data. The data is analyzed for any abrupt changes in the stuffing force as a function of the ram position indicating a crack in the assembled substrate.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to catalytic converters for internal combustion engine exhaust gases and the like, and in particular to a method for making catalytic converters with automated crack detection.[0002]Catalytic converters are commonly used to reduce noxious emissions in the exhaust gases of internal combustion engines, particularly those associated with vehicles. Such catalytic converters typically include a substrate made from cordierite, silicon carbide, aluminum titanate or the like, and have a honeycomb construction with axially extending, open ended cells through which the exhaust gases pass for treatment. Such substrates, which are relatively fragile or frangible, are wrapped with a mat and then stuffed into a rigid housing to create a tight friction fit between the substrate and the housing. Due to the fragile nature of the substrates, the same often develop cracks or fissures therein either during handling, prior to stuffing in the...

AI Technical Summary

Benefits of technology

[0008]The method for making catalytic converters with automated substrate crack detection is reliable, efficient, effective and particularly well adapted for the proposed use. These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings.

Problems solved by technology

Due to the fragile nature of the substrates, the same often develop cracks or fissures therein either during handling, prior to stuffing in the housing, or during the stuffing process itself.

Such cracks can severely impair the operation and effectiveness of the catalytic converter, and therefore must be detected and addressed prior to use of the catalytic converter in a vehicle.

While visual inspection of the finished catalytic converter parts does detect some such substrate cracks, such processes are relatively time-consuming, labor intensive, and are not very effective in locating internal fissures in the substrate.

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