Exhaust device of internal-combustion engine

Abstract

An exhaust device of an internal-combustion engine provided with a catalytic converter ( 8 ) arranged in an exhaust passage ( 3 ) of the internal-combustion engine ( 1 ); a fuel supply valve ( 7 ) that is arranged on the upstream side of the catalytic converter ( 8 ) and supplies fuel into the exhaust passage ( 3 ); an ignition device ( 21 ) capable of igniting the fuel supplied from the fuel supply valve ( 7 ); a pressure regulating device ( 16 ) that regulates the pressure of the fuel supplied to the fuel supply valve ( 7 ); and a controller ( 10 ) that controls the fuel supply valve ( 7 ) and the pressure regulating device ( 16 ). The controller ( 10 ) controls the fuel supply valve ( 7 ) and the pressure regulating device ( 16 ) so as to execute at least one of a plurality of injection operations having different fuel pressures from each other and performed successively, and a single injection operation performed while changing the fuel pressure.

1 . An exhaust device of an internal-combustion engine, comprising:
 a catalytic converter arranged in an exhaust passage of the internal-combustion engine;   a fuel supply valve that is arranged on the upstream side of the catalytic converter and supplies fuel into the exhaust passage;   an ignition device capable of igniting the fuel supplied from the fuel supply valve;   a pressure regulating device that regulates the pressure of the fuel supplied to the fuel supply valve; and   a controller that controls the fuel supply valve and the pressure regulating device, wherein   the controller controls the fuel supply valve and the pressure regulating device so as to execute at least one of a plurality of injection operations having different fuel pressures from each other and performed successively, and a single injection operation performed while changing the fuel pressure.   
     
     
         2 . The exhaust device of an internal-combustion engine according to  claim 1 , wherein
 the ignition device is arranged in proximity to the catalytic converter;   the controller causes the fuel supply valve to execute a plurality of injection operations having fuel pressures different from each other and performed successively;   the plurality of injection operations include a first injection operation having a first fuel pressure and a second injection operation executed after the first injection operation and having a second fuel pressure smaller than the first fuel pressure.   
     
     
         3 . The exhaust device of an internal-combustion engine according to  claim 1 , wherein
 an interval in a transverse direction of the exhaust passage between a heat generation portion of the ignition device and the fuel injection valve is smaller than an interval in the transverse direction of the exhaust passage between a collision point with which the fuel supplied from the fuel injection valve collides and the fuel injection valve.