Exhaust valve actuation system for diesel particulate filter regeneration

Abstract

An exhaust valve actuation system ( 30 ) for initiating a regeneration event at a diesel particulate filter ( 24 ) includes an engine control module ( 42 ) associated with an engine ( 14 ). A plurality of exhaust valves ( 32 ) correspond to a plurality of engine cylinders (C 1 -C 6 ). When either a predetermined amount of back pressure or a predetermined temperature, or both, are communicated to the engine control module ( 42 ), the engine control module actuates at least one exhaust valve ( 32 ) to open. Gas or gas-fuel mixture is compressed and heated inside of the cylinder (C 1 ) corresponding to the opened exhaust valve ( 32 ). At least one exhaust valve ( 32 ) is not opened by the engine control module ( 42 ), which permits combustion inside the corresponding cylinder (C 2 ).

1 ) An exhaust valve actuation system of an engine having a plurality of cylinders for initiating a regeneration event at a diesel particulate filter of an exhaust aftertreatment system, the exhaust valve actuation system comprising:
 an engine control module associated with the engine;   a plurality of exhaust valves corresponding to the plurality of engine cylinders;   wherein when at least one of a predetermined amount of back pressure and a predetermined temperature is communicated to the engine control module, the engine control module actuates at least one of the plurality of exhaust valves to open to permit the compression of gas or gas-fuel mixture inside the corresponding cylinder, and wherein at least one of the plurality of exhaust valves is not actuated to open to permit combustion inside the corresponding cylinder.   
     
     
         2 ) The exhaust valve actuation system of  claim 1  wherein the exhaust valves are opened using high pressure oil from a high pressure oil manifold associated with the engine. 
     
     
         3 ) The exhaust valve actuation system of  claim 2  wherein the high pressure oil manifold has an injection oil gallery and an exhaust valve gallery. 
     
     
         4 ) The exhaust valve actuation system of  claim 3  further comprising a shut-off valve operable to selectively prevent and allow the fluid communication of oil from the injection oil gallery to the exhaust valve gallery. 
     
     
         5 ) The exhaust valve actuation system of  claim 4  wherein when oil is communicated to the exhaust valve gallery, a piston is displaced from a retracted position to an extended position. 
     
     
         6 ) The exhaust valve actuation system of  claim 5  wherein displacement of the piston to the extended position opens the exhaust valve. 
     
     
         7 ) The exhaust valve actuation system of  claim 1  wherein the cylinder corresponding to the at least one open exhaust valve compresses gas or gas-fuel mixture resulting in heated, compressed gas or gas-fuel mixture, and the heated, compressed gas or gas-fuel mixture is fluidly communicated out of the exhaust valve to the diesel particulate filter. 
     
     
         8 ) The exhaust valve actuation system of  claim 1  wherein the cylinder corresponding to the at least one of the plurality of exhaust valves that is not open receives an increased amount of fuel resulting in heated exhaust gas, and the heated exhaust gas is fluidly communicated out of the exhaust valve to the diesel particulate filter. 
     
     
         9 ) The exhaust valve actuation system of  claim 1  wherein when the engine control module does not open the at least one exhaust valve, the corresponding cylinder is used for combustion. 
     
     
         10 ) The exhaust valve actuation system of  claim 1  further comprising at least one of a temperature sensor for sensing the temperature at the aftertreatment system and a back pressure sensor for sensing the pressure at the aftertreatment system, wherein at least one of the temperature sensor and the back pressure sensor communicate at least one of the temperature and the back pressure to the engine control module. 
     
     
         11 ) A method of regenerating an exhaust aftertreatment system of an engine having a diesel particulate filter, the method comprising:
 providing a fluid passageway from the engine to the diesel particulate filter;   sensing and communicating at least one of a back pressure of the aftertreatment system and a temperature of the aftertreatment system to an engine control module, and comparing at least one of the back pressure and the temperature to a predetermined back pressure and a predetermined temperature, wherein on the basis of the comparison, the engine control module actuates at least one exhaust valve of a cylinder;   opening the at least one exhaust valve to compress gas or gas-fuel mixture inside of the cylinder in response to the command of the engine control module, wherein not all exhaust valves are opened by the engine control module so that combustion can continue to occur at the remaining cylinders;   fluidly communicating the compressed, heated gas or gas-fuel mixture from the cylinder corresponding to the opened exhaust valve to the diesel particulate filter to initiate regeneration; and   fluidly communicating the combusted exhaust gases from the remaining cylinders to the diesel particulate filter to initiate regeneration.   
     
     
         12 ) The method of  claim 11  further comprising the step of the engine control module deactivating a shut-off valve and permitting oil from an injector oil gallery to flow to the exhaust valve gallery. 
     
     
         13 ) The method of  claim 12  further comprising the step of permitting oil to be distributed to a piston assembly that corresponds to the cylinder having the exhaust valve to be opened. 
     
     
         14 ) The method of  claim 13  further comprising the step of displacing a piston of the piston assembly from a retracted position to a deployed position under oil pressure. 
     
     
         15 ) The method of  claim 11  further comprising the step of injecting an increased amount of fuel into the remaining cylinders for combustion. 
     
     
         16 ) The method of  claim 11  further comprising the step of opening the exhaust valve on three cylinders, and not opening the exhaust valve on three cylinders. 
     
     
         17 ) The method of  claim 11  further comprising the step of injecting fuel into the cylinder corresponding to opened exhaust valve, and fluidly communicating the injected fuel to the aftertreatment system. 
     
     
         18 ) An exhaust valve actuation system of an engine having a plurality of cylinders for initiating a regeneration event at a diesel particulate filter of an exhaust aftertreatment system, the exhaust valve actuation system comprising:
 an engine control module associated with the engine;   at least one of a temperature sensor for sensing the temperature at the aftertreatment system and a back pressure sensor for sensing the pressure at the aftertreatment system, wherein at least one of the temperature sensor and the back pressure sensor communicate at least one of the temperature and the back pressure to the engine control module;   a plurality of exhaust valves corresponding to the plurality of cylinders in the engine;   a high pressure oil manifold associated with the engine and having a shut-off valve selectively preventing oil from an injector oil gallery from flowing to an exhaust valve gallery;   wherein when at least one of a predetermined amount of back pressure and a predetermined temperature is communicated to the engine control module, the engine control module deactivates the shut-off valve, permitting oil from the injector oil gallery to flow to the exhaust valve gallery to open at least one exhaust valve, wherein at least one of the plurality of exhaust valves is not actuated to open by the engine control module to permit combustion inside the corresponding cylinder.   
     
     
         19 ) The exhaust valve actuation system of  claim 18  wherein the oil in the exhaust valve gallery displaces a piston from a retracted position to an extended position. 
     
     
         20 ) The exhaust valve actuation system of  claim 19  wherein the displacement of the piston to the extended position opens the exhaust valve.