Method and apparatus for measuring effects of exhaust gas recirculation deposits

#1. Field of the Invention

#The present invention generally relates to exhaust system testing devices and methods and, more particularly, toward methods and devices for testing exhaust gas recirculation systems.

#2. Description of Related Art

#These and further features of the invention will be apparent with reference to the following detailed description and drawings, wherein:

#FIG. 1 schematically illustrates a testing system according to the present invention;

#FIG. 2 schematically illustrates a first testing jig according to the present invention;

#With reference to FIG. 1, a testing system according to the present invention is shown. The testing system includes a testing jig 10 that is connected to an exhaust 12 of an automobile engine 14. The engine exhaust 14 includes a catalytic converter 16 that preferably is disposed between the engine 14 and the testing jig 10. However, it is noted that in some circumstances it may be desirable to remove the catalytic converter 16. The testing jig 10 is connected to a downstream exhaust assembly 15 via an exhaust pipe 17. The engine 14 and testing jig 10 are preferably disposed in an environmentally controlled room 18 and the engine 14 is mounted to a dynometer 20, which is well known in the art. The environmentally controlled room 18 permits the engine 14 and testing jig 10 to be operated at a constant temperature in a consistent atmosphere, and will remove random variables from the testing procedure.

#The testing jig 10 according to a first preferred embodiment is schematically shown in FIG. 2 and includes a main branch 22, a test branch 24, and a control branch 26. The main branch 22 is preferably formed from a material that resists deposits from oxidation, such as 18 CrCb alloy steel, so as to provide a stable platform for several testing procedures. The main branch 22 extends generally longitudinally and defines an inlet section 22a, an outlet section 22b, and a main section 22c. The inlet section 22a is connected to the main section 22c by a first fitting 28, while the main section 22c is connected to the outlet section 22b by a second fitting 30. The first and second fittings 28, 30 also serve to connect the main branch 22 to the test branch 24 and the control branch 26, as will be described more fully hereinafter.

#The inlet and outlet sections 22a, 22b include flange-type fittings 32, 34 to facilitate their securement to other portions of the system. For example, the flange-type fitting 32 at the inlet section 22a facilitates attachment to an outlet pipe of the catalytic converter 16, while the flange-type fitting 34 at the outlet section 22b facilitates attachment to the downstream exhaust pipe 17. Further, each of the inlet and outlet sections 22a, 22b includes one or more pressure sensors and temperature sensors to facilitate determination and monitoring of these parameters by a controller (not shown).