# US 10,480,436 B2 · Exhaust purification system and catalyst regeneration method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,436 B2 - Document ID: US10480436B2 - Status: Granted - Kind: B2 - Application number: 15/545,643 - Filed: 2016-01-20 - Published: 2018-01-18 - Granted: 2019-11-19 - Earliest claimed: 2015-01-22 - Assignees: Isuzu Motors Limited - Applicants: Isuzu Motors Limited - Inventors: Teruo Nakada; Takayuki Sakamoto; Daiji Nagaoka - Web page: https://patentgrep.com/patent/US10480436B2 ## CPC - F02D 41/027: {to purge or regenerate the exhaust gas treating apparatus} - B01D 53/94: by catalytic processes - B01D 53/9422: {for removing nitrogen oxides by NOx storage or reduction by cyclic switching between lean and rich exhaust gases (LNT, NSC, NSR)} - B01D 53/9495: {Controlling the catalytic process} - B01D 53/96: Regeneration, reactivation or recycling of reactants - B01J 38/04: Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst - F01N 3/0814: {combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts} - F01N 3/0842: {Nitrogen oxides} - F01N 3/0871: {using means for controlling, e.g. purging, the absorbents or adsorbents} - F01N 3/20: specially adapted for catalytic conversion (F01N3/22 takes precedence) - F02D 41/0235: {in relation with the state of the exhaust gas treating apparatus (control of exhaust gas treating apparatus per se F01N)} - F02D 45/00: Electrical control not provided for in groups F02D41/00 - F02D43/00 - F01N 2430/06: by varying fuel-air ratio, e.g. by enriching fuel-air mixture - F01N 2900/08: said parameters being related to the engine - F01N 2900/1402: Exhaust gas composition - F02D 41/3005: {Details not otherwise provided for} - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - 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) ## Abstract There is provided: a NOx-occlusion-reduction-type catalyst 32 that is provided in an exhaust passage 13 of an internal combustion engine 10; a NOx purge control unit 60 that performs a NOx purge control of setting the exhaust in the rich state and reducing and purifying NOx occluded in the NOx-occlusion-reduction-type catalyst 32; and a NOx purge inhibition processing unit 70 that inhibits NOx purge control when the internal combustion engine 10 becomes a motoring state in which fuel injection is stopped, and inhibiting, when the internal combustion engine 10 has started fuel injection during the inhibition of the NOx purge control, performance of the NOx purge control from the start of the fuel injection until a predetermined period of time has elapsed. ## Claims ### Claim 1 An exhaust purification system comprising: a NOx-occlusion-reduction-type catalyst that is provided in an exhaust passage of an internal combustion engine, occludes NOx in exhaust when the exhaust is in a lean state, and reduces and purifies the occluded NOx when the exhaust is in a rich state; an electronic control unit (ECU) for: performing catalyst regeneration processing of setting the exhaust in the rich state and reducing and purifying the NOx occluded in the NOx-occlusion-reduction-type catalyst; and inhibiting performance of the catalyst regeneration processing by the ECU when the internal combustion engine becomes a motoring state in which fuel injection is stopped, and inhibiting, when the internal combustion engine has started fuel injection during the inhibition, performance of the catalyst regeneration processing from start of the fuel injection until a predetermined time period has elapsed, wherein when an increase rate in a fuel injection amount of the internal combustion engine exceeds a predetermined upper limit threshold value, the ECU inhibits performance of the catalyst regeneration processing, and when the increase rate in the fuel injection amount of the internal combustion engine decreases to the upper limit threshold value or smaller during the inhibition, the ECU inhibits performance of the catalyst regeneration processing from when the increase rate in the fuel injection amount of the internal combustion engine has decreased to the upper limit threshold value or smaller until a predetermined time period has elapsed. ### Claim 2 (depends on 1) The exhaust purification system according to claim 1, wherein when an decrease rate in a fuel injection amount of the internal combustion engine decreases below a predetermined lower limit threshold value, the ECU inhibits performance of the catalyst regeneration processing, and when the decrease rate in the fuel injection amount of the internal combustion engine recovers to the lower limit threshold value or greater during the inhibition, the ECU inhibits performance of the catalyst regeneration processing from when the decrease rate in the fuel injection amount of the internal combustion engine has recovered to the lower limit threshold value or greater until a predetermined time period has elapsed. ### Claim 3 An exhaust purification system comprising: a NOx-occlusion-reduction-type catalyst that is provided in an exhaust passage of an internal combustion engine, occludes NOx in exhaust when the exhaust is in a lean state, and reduces and purifies the occluded NOx when the exhaust is in a rich state, and a control unit, wherein the control unit operates so as to execute the following processing: catalyst regeneration processing of reducing and purifying the NOx occluded in the NOx-occlusion-reduction-type catalyst by controlling at least one of an intake flow rate and a fuel injection amount to set the exhaust in the rich state, and inhibition processing of inhibiting performance of the catalyst regeneration processing when the internal combustion engine becomes a motoring state in which fuel injection is stopped, and inhibiting, when the internal combustion engine has started the fuel injection during the inhibition, performance of the catalyst regeneration processing from start of the fuel injection until a predetermined time period has elapsed, and wherein when an increase rate in a fuel injection amount of the internal combustion engine exceeds a predetermined upper limit threshold value, the control unit inhibits performance of the catalyst regeneration processing, and when the increase rate in the fuel injection amount of the internal combustion engine decreases to the upper limit threshold value or smaller during the inhibition, the control unit inhibits performance of the catalyst regeneration processing from when the increase rate in the fuel injection amount of the internal combustion engine has decreased to the upper limit threshold value or smaller until a predetermined time period has elapsed. ### Claim 4 A catalyst regeneration method in an exhaust purification system including: an internal combustion engine; and a NOx-occlusion-reduction-type catalyst that is provided in an exhaust passage of the internal combustion engine, occludes NOx in exhaust when the exhaust is in a lean state and reduces, and purifies the occluded NOx when the exhaust is in a rich state, the method comprising: catalyst regeneration processing of reducing and purifying the NOx occluded in the NOx-occlusion-reduction-type catalyst by setting the exhaust in the rich state, and inhibition processing of inhibiting performance of the catalyst regeneration processing when the internal combustion engine becomes a motoring state in which fuel injection is stopped, and inhibiting, when the internal combustion engine has started the fuel injection during the inhibition, performance of the catalyst regeneration processing from start of the fuel injection until a predetermined time period has elapsed, wherein when an increase rate in a fuel injection amount of the internal combustion engine exceeds a predetermined upper limit threshold value, the inhibition processing inhibits performance of the catalyst regeneration processing, and when the increase rate in the fuel injection amount of the internal combustion engine decreases to the upper limit threshold value or smaller during the inhibition, the inhibition processing inhibits performance of the catalyst regeneration processing from when the increase rate in the fuel injection amount of the internal combustion engine has decreased to the upper limit threshold value or smaller until a predetermined time period has elapsed.