Exhaust Gas Processing Device

Abstract

In an exhaust gas processing device, an air-fuel ratio sensor is provided such that a measuring portion is located in a region surrounded by a downstream-side end surface of a TWC, an upstream-side end surface of a GPF, and an inner wall surface of a case against which the exhaust gas G that has passed through the TWC flows, that is the region a region on the GPF side of the center of the TWC.

What is claimed is: 
     
         1 . An exhaust gas processing device comprising:
 a first catalyst carrier configured to clean exhaust gas flowing along a first direction;   a second catalyst carrier configured to clean the exhaust gas that has passed through the first catalyst carrier, the exhaust gas flowing along a second direction intersecting with the first direction;   a case configured to accommodate the first catalyst carrier and the second catalyst carrier;   a sensor having a measuring portion for measuring the exhaust gas, the sensor being configured to determine the exhaust gas that has passed through the first catalyst carrier;   an outer circumference flow path provided between an outer circumferential surface of the first catalyst carrier and an inner circumferential surface of the case, the outer circumference flow path surrounding an outer circumference of the first catalyst carrier entirely; and   a dividing portion formed by the case protruded inwardly, the dividing portion being configured to divide the exhaust gas that has passed through the first catalyst carrier so as to guide the exhaust gas towards each of the second catalyst carrier and the outer circumference flow path, wherein   the case has a barrel portion configured to form the outer circumference flow path with the outer circumferential surface of the first catalyst carrier, the outer circumference flow path being configured to allow the exhaust gas to flow through,   the first catalyst carrier is accommodated in an inner case over an entirety in the first direction, the inner case being provided in the case so as to face the barrel portion such that the outer circumference flow path is sandwiched between the inner case and the barrel portion, and   the measuring portion of the sensor is arranged in a region surrounded by a downstream-side end surface of the first catalyst carrier, an upstream-side end surface of the second catalyst carrier, and an inner wall surface of the case, the inner wall surface being configured to receive the exhaust gas that has passed through the first catalyst carrier, the region being on a second catalyst carrier side of a center of the first catalyst carrier.   
     
     
         2 . An exhaust gas processing device comprising:
 a first catalyst carrier configured to clean exhaust gas flowing along a first direction;   a second catalyst carrier configured to clean the exhaust gas that has passed through the first catalyst carrier, the exhaust gas flowing along a second direction intersecting with the first direction;   a case configured to accommodate the first catalyst carrier and the second catalyst carrier;   a sensor having a measuring portion for measuring the exhaust gas at a tip, the sensor being configured to determine the exhaust gas that has passed through the first catalyst carrier;   an outer circumference flow path provided between an outer circumferential surface of the first catalyst carrier and an inner circumferential surface of the case, the outer circumference flow path surrounding an outer circumference of the first catalyst carrier entirely; and   a dividing portion formed by the case protruded inwardly, the dividing portion being configured to divide the exhaust gas that has passed through the first catalyst carrier so as to guide the exhaust gas towards each of the second catalyst carrier and the outer circumference flow path, wherein   the first catalyst carrier and the second catalyst carrier provided on an upstream of the first catalyst carrier in the first direction are accommodated in an inner case fixed within the case, and   the measuring portion of the sensor is arranged in a region surrounded by a downstream-side end surface of the first catalyst carrier, an upstream-side end surface of the second catalyst carrier, and an inner wall surface of the case, the inner wall surface being configured to receive the exhaust gas that has passed through the first catalyst carrier, the region being on the second catalyst carrier side of a center of the first catalyst carrier.   
     
     
         3 . The exhaust gas processing device according to  claim 1 , further comprising:
 an electrically heated catalyst arranged on an upstream side of the first catalyst carrier, the electrically heated catalyst having a heater for heating the exhaust gas, wherein   the exhaust gas heated and cleaned by the electrically heated catalyst is cleaned by the first catalyst carrier.   
     
     
         4 . The exhaust gas processing device according to  claim 1 , further comprising:
 a heater arranged on an upstream side of the first catalyst carrier, the heater being configured to heat the exhaust gas, wherein   the exhaust gas heated by the heater is cleaned by the first catalyst carrier.   
     
     
         5 . The exhaust gas processing device according to  claim 1 , wherein the first catalyst carrier has a metallic layer provided on the outer circumferential surface, the metallic layer being configured to be able to heat the first catalyst carrier by supplying electricity. 
     
     
         6 . The exhaust gas processing device according to  claim 1 , wherein the second catalyst carrier is arranged on a downstream side of the first catalyst carrier in a direction of a gravitational force. 
     
     
         7 . The exhaust gas processing device according to  claim 1 , wherein the measuring portion is arranged so as to face down in a direction of a gravitational force. 
     
     
         8 . The exhaust gas processing device according to  claim 1 , wherein the sensor is arranged so that the measuring portion is arranged so as to face downstream in a flowing direction of the exhaust gas. 
     
     
         9 . The exhaust gas processing device according to  claim 1 , wherein the measuring portion is arranged in a region in which the exhaust gas flows in a tangential direction with respect to a top part of the dividing portion protruding in the first direction, the exhaust gas flowing towards the second catalyst carrier by being divided by the dividing portion. 
     
     
         10 . The exhaust gas processing device according to  claim 1 , wherein
 the case has a bonded portion formed by abutting and joining plate members, and   the sensor is attached at a position avoiding the bonded portion.   
     
     
         11 . The exhaust gas processing device according to  claim 1 , wherein, when the first catalyst carrier and the second catalyst carrier are viewed from a direction intersecting with the first direction and the second direction perpendicularly, both ends of the first catalyst carrier in the first direction are located between both ends of the second catalyst carrier in the first direction. 
     
     
         12 . The exhaust gas processing device according to  claim 1 , wherein
 the case has a barrel portion configured to form the outer circumference flow path with the outer circumferential surface of the first catalyst carrier, the outer circumference flow path being configured to allow the exhaust gas to flow through, and   a guide portion configured to guide a remaining of the exhaust gas that has been subjected to division, the remaining of the exhaust gas being guided to the outer circumference flow path.   
     
     
         13 . The exhaust gas processing device according to  claim 1 , wherein a guide portion has a tilted portion tilted with respect to a flat plane orthogonal to the first direction by a predetermined angle from the dividing portion towards a downstream side in the first direction. 
     
     
         14 . The exhaust gas processing device according to  claim 1 , wherein a main body portion of the sensor is attached to a flat surface portion in a depression provided on an outside of the case by a formation of the dividing portion. 
     
     
         15 . The exhaust gas processing device according to  claim 1 , wherein the sensor is mounted from an outside of the case such that the measuring portion is positioned toward the second catalyst carrier.