Device for diagnosing a particle filter

Abstract

A device for diagnosing a particle filter attached onto a main exhaust line of an internal combustion engine, wherein the diagnosis device includes, downstream from the first particle filter, a detection filter and a sensor for measuring an output parameter of the detection filter. The detection filter is arranged in a secondary exhaust line through which a first portion of the gases from the particle filter passes, wherein a second portion of the gases from the particle filter follows the main exhaust line. The device can be used for diagnosing particle filters for an automobile having a combustion engine.

1 . A device for diagnosing a particle filter connected to a main exhaust line of an internal combustion engine, the diagnostic device comprising:
 a detection filter; and   a tool for measuring an outlet parameter of the detection filter, wherein an initial part of gases discharged from the particle filter flow through the detection filter, and a second part of the gases discharged from the particle filter flow through the main exhaust line, and the detection filter is inserted into a secondary exhaust line extending at least partially outside the main line, the secondary exhaust line having an inlet and an outlet, the secondary exhaust line inlet is connected to the main exhaust line after the particle filter.   
     
     
         2 . The device of  claim 1 , wherein the initial part of the gases corresponds to 0.1 at 70% of the gases discharged from the particle filter. 
     
     
         3 . The device of  claim 2 , wherein the initial part of the gases corresponds to 0.1 at 5%, 10%, or 15% of the gases discharged from the particle filter. 
     
     
         4 . The device of  claim 1 , further comprising an additional element situated after the particle filter, wherein the secondary exhaust line outlet is connected to the main line after the additional element. 
     
     
         5 . The device of  claim 1 , further comprising an additional element situated after the particle filter, wherein the secondary exhaust line outlet is connected to the main line between the particle filter and the additional element. 
     
     
         6 . The device of  claim 1 , wherein the secondary line outlet is connected to the main line after the detection filter. 
     
     
         7 . The device of  claim 4 , wherein the secondary exhaust line and the secondary exhaust line outlet, situated inside the additional element. 
     
     
         8 . The device of  claim 1 , wherein the secondary exhaust line outlet is connected to the main line below the secondary exhaust line inlet. 
     
     
         9 . The device of  claim 1 , wherein the secondary exhaust line inlet and the secondary exhaust line outlet are connected to the main line with the difference in pressure between the inlet and outlet of the secondary exhaust line being greater than a dynamic pressure of the gases in the main exhaust line. 
     
     
         10 . The device of  claim 1 , wherein a section of the main line includes a narrowed portion adjacent to the secondary exhaust line inlet. 
     
     
         11 . The device of  claim 1 , wherein the secondary exhaust line inlet is defined by an input section situated in the main line. 
     
     
         12 . The device of  claim 1 , wherein the detection filter includes filtration properties, and an alarm condition is generated by the measuring tool when the level of particles contained in the gases discharged from the particle filter is greater than a predetermined amount. 
     
     
         13 . The device of  claim 1 , further comprising a thermal dispersal element having a low level of loss of load and situated after the detection filter. 
     
     
         14 . The device of  claim 1 , wherein the secondary exhaust line includes a gas entry section, the gas entry section is situated in the main exhaust line after the particle filter, the detection filter is situated in the gas entry section, and a thermal dissipating element having a reduced loss of load is situated after the detection filter in the secondary exhaust line extending at least partially outside the main line. 
     
     
         15 . The device of  claim 1 , wherein the measuring tool is selected from the group consisting of a temperature sensor, a flow sensor, an output speed sensor, and an oxygen concentration sensor for measuring exhaust gases exiting the detection filter outlet. 
     
     
         16 . The device of  claim 1 , wherein the measuring tool includes a sensor situated after the detection filter in the secondary exhaust line extending at least partially outside the main line. 
     
     
         17 . The device of  claim 1 , further comprising an alarm that generates an alarm signal if a profile of the detection filter outlet parameter is different from a reference profile. 
     
     
         18 . A diagnostic method for the operation of a particle filter, the particle filter connected to a main exhaust line of an internal combustion engine, the diagnostic device including a detection filter and a means for measuring a detection filter outlet parameter, and a predetermined portion of the exhaust gas passing through the detection filter, comprising:
 detecting a change in the the detection filter outlet parameter;   comparing an outlet parameter with a calibrated reference value; and   determining a failure condition in the particle filter using an output value from the comparing step.   
     
     
         19 . The method of  claim 18 , wherein the failure condition in the particle filter is generated when the outlet parameter value varies from the calibrated reference value calibrated during a period of surveillance lasting for less than the calibrated duration. 
     
     
         20 . The method of  claim 19 , wherein the calibrated duration is representative of a timed period of use or set mileage covered. 
     
     
         21 . The method of  claim 18 , wherein the outlet parameter value is indicative of a measured or estimated value of a gradient of measured or estimated values. 
     
     
         22 . The method of  claim 18 , wherein the detection filter is situated in a secondary exhaust line, the secondary exhaust line having a gas inlet and outlet, and the gas inlet is connected to the main exhaust line after the particle filter. 
     
     
         23 . (canceled) 
     
     
         24 . The device of  claim 1 , wherein the additional element is a resonator. 
     
     
         25 . The device of  claim 1 , wherein the additional element is a muffler. 
     
     
         26 . The device of  claim 1 , wherein the secondary exhaust line outlet is connected to an air input line from the engine. 
     
     
         27 . The device of  claim 1 , wherein the secondary exhaust line outlet is discharged into the open air. 
     
     
         28 . The device of  claim 1 , wherein the measuring tool is a differential measuring device having a first sensor situated prior to the detection filter, a second sensor situated after the detection filter, and a comparator for determining a difference in pressure between an inlet parameter and the outlet parameter of the detection filter. 
     
     
         29 . The device of  claim 1 , wherein the diagnostic device is installed below the first particle filter. 
     
     
         30 . A device for diagnosing a particle filter connected to a main exhaust line of an internal combustion engine, the diagnostic device comprising:
 a detection filter; and   a tool for measuring an outlet parameter of the detection filter, wherein an initial part of gases discharged from the particle filter flow through the detection filter, and a second part of the gases discharged from the particle filter flow through the main exhaust line, and the detection filter is inserted into a secondary exhaust line extending at least partially outside the main line, the secondary exhaust line having an inlet and an outlet, the secondary exhaust line inlet is connected to the main exhaust line after the particle filter, and the secondary exhaust line inlet is defined by an input section situated in the main line.   
     
     
         31 . A device for diagnosing a particle filter connected to a main exhaust line of an internal combustion engine, the diagnostic device comprising:
 a detection filter; and   a tool for measuring an outlet parameter of the detection filter, wherein an initial part of gases discharged from the particle filter flow through the detection filter, and a second part of the gases discharged from the particle filter flow through the main exhaust line, and the detection filter is inserted into a secondary exhaust line extending at least partially outside the main line, the secondary exhaust line having an inlet and an outlet, the secondary exhaust line inlet is connected to the main exhaust line after the particle filter, and the detection filter includes filtration properties, and an alarm condition is generated by the measuring tool when the level of particles contained in the gases discharged from the particle filter is greater than a predetermined amount.