# US 9,518,490 B2 · Exhaust gas processing device for engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,490 B2 - Document ID: US9518490B2 - Status: Granted - Kind: B2 - Application number: 14/641,577 - Filed: 2015-03-09 - Published: 2015-10-01 - Granted: 2016-12-13 - Earliest claimed: 2014-03-28 - Assignees: Kubota Corporation - Applicants: KUBOTA Corporation - Inventors: Katsuaki Arai; Takashi Onishi; Yoshikazu Takemoto; Tomoya Akitomo - Web page: https://patentgrep.com/patent/US9518490B2 ## CPC - F01N 3/2006: {Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating (by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235)} - F01N 3/0256: {the fuel being ignited by electrical means} - F01N 3/035: with catalytic reactors - F01N 3/36: Arrangements for supply of additional fuel - F01N 3/38: Arrangements for igniting - F01N 9/002: {of filter regeneration} - F01N 13/008: {Mounting or arrangement of exhaust sensors in or on exhaust apparatus (sensor arrangements for engine control F02D41/1439)} - F01N 3/103: {Oxidation catalysts for HC and CO only} - F01N 13/0097: {the purifying devices are arranged in a single housing} - F01N 2240/14: a fuel burner - F01N 2240/16: an electric heater, i.e. a resistance heater - F01N 2560/06: the means being a temperature sensor - F01N 2560/08: the means being a pressure sensor - F01N 2560/14: having more than one sensor of one kind - F01N 2610/04: the substance being hydrogen - F01N 2610/107: using glow plug heating elements - Y02T 10/12: Improving ICE efficiencies - Y02T 10/40: Engine management systems - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An exhaust gas processing device for an engine, capable of securely warming a combustion catalyst, is provided. A combustion catalyst burning gas is produced when a warming end condition for the combustion catalyst is established, which signifies the establishment of either one of a first condition or a second condition. In the first condition, an inlet temperature of a combustion catalyst is equal to or higher than an activation requirement temperature of the combustion catalyst, and further, an outlet temperature of the combustion catalyst is equal to or higher than an activation confirmation temperature of the combustion catalyst in excess of the inlet temperature of the combustion catalyst. In the second condition, the outlet temperature of the combustion catalyst exceeds a warming confirmation temperature of the combustion catalyst that is set to be higher as an engine speed is lower, for a predetermined period of time. ## Claims ### Claim 1 An exhaust gas processing device for an engine comprising: a combustible gas producer, a combustion catalyst, an exhaust processing unit, and a control unit, the exhaust gas processing device being configured such that a combustion catalyst burning gas is produced by the combustible gas producer under the control of the control unit, the resultant combustion catalyst burning gas is mixed with an exhaust gas passing an engine exhaust gas channel and catalytically burned with the combustion catalyst, and then, the exhaust gas whose temperature is increased by catalyst combustion is supplied to the exhaust processing unit, wherein the control unit allows the combustible gas producer to produce a combustion catalyst warming gas before the combustion catalyst burning gas is produced, the resultant combustion catalyst warming gas is mixed with the exhaust gas passing the engine exhaust gas channel and ignited by an igniter disposed upstream of the combustion catalyst that is thus warmed with the exhaust gas whose temperature is increased by flame combustion; the combustion catalyst burning gas is produced in the case where a warming end condition for the combustion catalyst is established; and the establishment of the warming end condition for the combustion catalyst signifies the establishment of either one of a first condition or a second condition: the first condition in which an inlet temperature of the combustion catalyst is equal to or higher than an activation requirement temperature of the combustion catalyst, and further, an outlet temperature of the combustion catalyst is equal to or higher than an activation confirmation temperature of the combustion catalyst in excess of the inlet temperature of the combustion catalyst; and the second condition in which the outlet temperature of the combustion catalyst exceeds a warming confirmation temperature of the combustion catalyst that is set to be higher as an engine speed is lower, for a predetermined period of time. ### Claim 2 (depends on 1) The exhaust gas processing device for an engine according to claim 1, wherein a target reaction temperature of a gas production catalyst in the combustible gas producer is set to be higher in the case where the combustion catalyst warming gas is produced than in the case where the combustion catalyst burning gas is produced, so that the ignition quality of the combustion catalyst warming gas is more enhanced than that of the combustion catalyst burning gas. ### Claim 3 (depends on 2) The exhaust gas processing device for an engine according to claim 2, wherein the combustible gas producer is provided with a heater, and the control unit allows the gas production catalyst to be warmed by heat generated by the heater before the combustion catalyst warming gas is produced with the gas production catalyst, and the energization to the heater is ended after a lapse of a predetermined period of time after the energization to the heater is started: in contrast, the control unit allows the igniter to be started to be energized before the ending, so that the igniter is pre-heated before the combustion catalyst warming gas is produced. ### Claim 4 (depends on 3) The exhaust gas processing device for an engine according to claim 3, further comprising a PM accumulation amount estimator for the combustion catalyst, wherein in the case where a predetermined combustion catalyst reproduction requirement condition is satisfied based on a PM accumulation estimation value of the combustion catalyst, the control unit allows the combustible gas producer to produce a combustion catalyst reproducing gas, the resultant combustion catalyst reproducing gas is mixed with the exhaust gas passing the engine exhaust gas channel and is ignited by the igniter, and PM accumulated on the combustion catalyst is burned and removed with the exhaust gas whose temperature is increased by the flame combustion, thus reproducing the combustion catalyst. ### Claim 5 (depends on 4) The exhaust gas processing device for an engine according to claim 4, further comprising an ignition status detector for the igniter, wherein the control unit allows the combustible gas producer to produce a re-igniting gas in the case where the ignition status detector detects that the combustion catalyst reproducing gas is not ignited, and a target reaction temperature of the gas production catalyst in the combustible gas producer in the case where the re-igniting gas is produced is set to be higher than that in the case where the combustion catalyst reproducing gas is produced, so that the ignition quality of the re-igniting gas is more enhanced than that of the combustion catalyst reproducing gas. ### Claim 6 (depends on 2) The exhaust gas processing device for an engine according to claim 2, further comprising a PM accumulation amount estimator for the combustion catalyst, wherein in the case where a predetermined combustion catalyst reproduction requirement condition is satisfied based on a PM accumulation estimation value of the combustion catalyst, the control unit allows the combustible gas producer to produce a combustion catalyst reproducing gas, the resultant combustion catalyst reproducing gas is mixed with the exhaust gas passing the engine exhaust gas channel and is ignited by the igniter, and PM accumulated on the combustion catalyst is burned and removed with the exhaust gas whose temperature is increased by the flame combustion, thus reproducing the combustion catalyst. ### Claim 7 (depends on 6) The exhaust gas processing device for an engine according to claim 6, further comprising an ignition status detector for the igniter, wherein the control unit allows the combustible gas producer to produce a re-igniting gas in the case where the ignition status detector detects that the combustion catalyst reproducing gas is not ignited, and a target reaction temperature of the gas production catalyst in the combustible gas producer in the case where the re-igniting gas is produced is set to be higher than that in the case where the combustion catalyst reproducing gas is produced, so that the ignition quality of the re-igniting gas is more enhanced than that of the combustion catalyst reproducing gas. ### Claim 8 (depends on 1) The exhaust gas processing device for an engine according to claim 1, further comprising a PM accumulation amount estimator for the combustion catalyst, wherein in the case where a predetermined combustion catalyst reproduction requirement condition is satisfied based on a PM accumulation estimation value of the combustion catalyst, the control unit allows the combustible gas producer to produce a combustion catalyst reproducing gas, the resultant combustion catalyst reproducing gas is mixed with the exhaust gas passing the engine exhaust gas channel and is ignited by the igniter, and PM accumulated on the combustion catalyst is burned and removed with the exhaust gas whose temperature is increased by the flame combustion, thus reproducing the combustion catalyst. ### Claim 9 (depends on 8) The exhaust gas processing device for an engine according to claim 8, further comprising an ignition status detector for the igniter, wherein the control unit allows the combustible gas producer to produce a re-igniting gas in the case where the ignition status detector detects that the combustion catalyst reproducing gas is not ignited, and a target reaction temperature of the gas production catalyst in the combustible gas producer in the case where the re-igniting gas is produced is set to be higher than that in the case where the combustion catalyst reproducing gas is produced, so that the ignition quality of the re-igniting gas is more enhanced than that of the combustion catalyst reproducing gas.