Device for monitoring an exhaust gas catalytic converter for an internal combustion engine

Abstract

A device for monitoring an exhaust gas catalytic converter in the exhaust system of an internal combustion engine, includes a measuring apparatus that is arranged in the exhaust system in such a way that, in the greatest part of the operating range of the internal combustion engine, it assumes a temperature that is correlated with a temperature of the exhaust gas catalytic converter. The measuring apparatus has a temperature-sensitive component with a temperature-dependent characteristic component parameter that changes either abruptly at a predetermined transition temperature or temperature range, or continuously in a predetermined way as a function of the temperature. A control and evaluation unit connected to the measuring arrangement detects the characteristic component parameter and/or a change in the latter, and correlates it with an aging state of the exhaust gas catalytic converter.

1 .- 9 . (canceled) 
   
   
       10 . A device for monitoring an exhaust gas catalytic converter in the exhaust system of an internal combustion engine, said device comprising:
 measuring apparatus arranged in the exhaust system such that, in at least a predominant part of the operating range of the internal combustion engine, it assumes a temperature that is correlated with a temperature of the exhaust gas catalytic converter; and   a control evaluation unit that is coupled in communication with the measuring apparatus; wherein   the measuring apparatus has a temperature-sensitive component with a temperature dependent characteristic component parameter that changes either abruptly at a predetermined transition temperature or temperature range, or continuously in a predetermined way as a function of temperature; and   the control and evaluation unit can detect the characteristic component parameter and/or a change in the characteristic component parameter.   
   
   
       11 . The device as claimed in  claim 10 , wherein the measuring apparatus is fixedly connected to one of the exhaust gas catalytic converter, and a housing in which the exhaust gas catalytic converter is arranged. 
   
   
       12 . The device as claimed in  claim 10 , wherein the change that occurs in the characteristic component parameter is irreversible. 
   
   
       13 . The device as claimed in  claim 10 , wherein the change that occurs in the characteristic component parameter comprises a structural transformation of a material constituent of the temperature-sensitive component. 
   
   
       14 . The device as claimed in  claim 10 , wherein the temperature-sensitive component of the measuring apparatus is a passive electrical structural element. 
   
   
       15 . The device as claimed in  claim 10 , wherein the temperature-sensitive component is produced by thick-film technology. 
   
   
       16 . The device as claimed in  claim 10 , wherein the measuring apparatus comprises a plurality of temperature-sensitive components, and one of the following is true:
 individual temperature-sensitive components differ from one another in terms of the transition temperature or temperature range of their characteristic component parameter; and   individual temperature-sensitive components have characteristic component parameters that change in time in a different way, as a function of the temperature.   
   
   
       17 . The device as claimed in  claim 10  wherein, the temperature-sensitive component is designed in such a way that the transition temperature or temperature range of its characteristic component parameter is correlated with a permissible upper operating temperature of the exhaust gas catalytic converter, or the change in the characteristic component parameter which occurs in the course of time is correlated with a parallel-running aging of the exhaust gas catalytic converter.