# US 11,441,471 B2 · Exhaust purifying apparatus and method for controlling exhaust purifying apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,471 B2 - Document ID: US11441471B2 - Status: Granted - Kind: B2 - Application number: 17/319,091 - Filed: 2021-05-13 - Published: 2021-11-25 - Granted: 2022-09-13 - Earliest claimed: 2020-05-19 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Takahiro Sadamitsu - Web page: https://patentgrep.com/patent/US11441471B2 ## CPC - F01N 9/002: {of filter regeneration} - F01N 3/0253: {adding fuel to exhaust gases} - F01N 3/027: using electric or magnetic heating means - F01N 3/035: with catalytic reactors - F01N 3/2026: {directly electrifying the catalyst substrate, i.e. heating the electrically conductive catalyst substrate by joule effect} - F01N 2240/16: an electric heater, i.e. a resistance heater - F01N 2250/02: filtering and catalytic conversion - F01N 2260/04: for regeneration or reactivation, e.g. of catalyst - F01N 2390/02: using electric components only - F01N 2900/0602: Electrical exhaust heater signals - F01N 2900/08: said parameters being related to the engine - F01N 2900/1602: Temperature of exhaust gas apparatus - F01N 2900/1606: Particle filter loading or soot amount - 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 A controller controls energization of a filter and a fuel addition valve in an exhaust purifying apparatus. The controller executes a filter regeneration process when an electrical resistance value between two electrodes fixed to an outer surface of the filter is less than a predetermined regeneration determination value. The controller executes a soot burning process when the electrical resistance value is greater than or equal to the regeneration determination value and less than a soot burning determination value, which is set in advance to be larger than the regeneration determination value. ## Claims ### Claim 1 An exhaust purifying apparatus comprising: a filter device, the filter device including: a particulate matter trapping filter arranged in an exhaust pipe of an internal combustion engine, the particulate matter trapping filter being made of an electrically conductive material; and two electrodes fixed to an outer surface of the particulate matter trapping filter; a resistance value obtaining unit including a controller configured to obtain an electrical resistance value between the two electrodes; an energy supplying unit configured to supply energy converted into heat received by the particulate matter trapping filter; and the controller further configured to execute a filter regeneration process and a soot burning process, the filter regeneration process eliminating soot deposited in the particulate matter trapping filter with the energy supplied by the energy supplying unit, the soot burning process eliminating soot deposited in a gap portion between the particulate matter trapping filter and the exhaust pipe with the energy supplied by the energy supplying unit, wherein a total amount of the energy supplied by the energy supplying unit during the filter regeneration process is larger than a total amount of the energy supplied by the energy supplying unit during the soot burning process, and the controller is configured to execute the filter regeneration process when the electrical resistance value obtained by the resistance value obtaining unit is less than a predetermined first determination value and execute the soot burning process when the electrical resistance value is greater than or equal to the predetermined first determination value and less than a second determination value that has been set in advance to be larger than the predetermined first determination value. ### Claim 2 (depends on 1) The exhaust purifying apparatus according to claim 1, wherein an execution time of the filter regeneration process is longer than an execution time of the soot burning process. ### Claim 3 (depends on 1) The exhaust purifying apparatus according to claim 1, wherein the filter regeneration process is executed on a condition that a load on the internal combustion engine is greater than or equal to a predetermined value. ### Claim 4 (depends on 1) The exhaust purifying apparatus according to claim 1, wherein the particulate matter trapping filter supports an oxidation catalyst that expedites oxidation of unburned fuel in exhaust gas, and the energy supplying unit is configured to supply, as the energy, unburned fuel added to the exhaust gas before flowing into the particulate matter trapping filter. ### Claim 5 (depends on 1) The exhaust purifying apparatus according to claim 1, wherein the controller is configured to execute the soot burning process when a decrease in an insulation resistance between the particulate matter trapping filter and the exhaust pipe is detected. ### Claim 6 A method for controlling an exhaust purifying apparatus that includes a filter device, wherein the filter device includes: a particulate matter trapping filter arranged in an exhaust pipe of an internal combustion engine, the particulate matter trapping filter being made of an electrically conductive material; and two electrodes fixed to an outer surface of the particulate matter trapping filter; the method comprises: obtaining an electrical resistance value between the two electrodes; supplying energy converted into heat received by the particulate matter trapping filter; and executing a filter regeneration process and a soot burning process, the filter regeneration process eliminating soot deposited in the particulate matter trapping filter with the energy supplied, the soot burning process eliminating soot deposited in a gap portion between the particulate matter trapping filter and the exhaust pipe with the energy supplied, a total amount of the energy supplied during the filter regeneration process is larger than a total amount of the energy supplied during the soot burning process, and the method further comprises executing the filter regeneration process when the electrical resistance value between the two electrodes is less than a predetermined first determination value and executing the soot burning process when the electrical resistance value between the two electrodes is greater than or equal to the first determination value and less than a second determination value that has been set in advance to be larger than the first determination value.