# US 10,502,175 B2 · Control device for internal combustion engine and method of estimating combustion chamber-wall temperature of internal combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,175 B2 - Document ID: US10502175B2 - Status: Granted - Kind: B2 - Application number: 15/760,654 - Filed: 2017-12-15 - Published: 2019-02-07 - Granted: 2019-12-10 - Earliest claimed: 2016-12-19 - Assignees: Hitachi Automotive Systems, Ltd. - Applicants: Hitachi Automotive Systems, Ltd. - Inventors: Yuichi Toyama; Shigeyuki Sakaguchi; Atsushi Murai - Web page: https://patentgrep.com/patent/US10502175B2 ## CPC - F02P 5/045: {combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02)} - F02D 13/0234: {changing the valve timing only} - F02D 15/02: by alteration or displacement of piston stroke - F02D 35/026: {using an estimation} - F02D 41/123: {the fuel injection being cut-off} - F02D 41/18: by measuring intake air flow - F02D 41/32: of the low pressure type {(F02D41/3082 takes precedence)} - F02P 5/15: Digital data processing - F02D 13/0238: {by shifting the phase, i.e. the opening periods of the valves are constant} - F02D 41/047: {Taking into account fuel evaporation or wall wetting; (special correction after fuel cut-off F02D41/126)} - F02D 2041/001: {for engines with variable valve actuation} - F02D 2200/021: Engine temperature - F02D 2200/022: Estimation of engine temperature - F02D 2200/101: Engine speed - F02P 5/152: dependent on pinking (detecting or indicating knocks in internal-combustion engines G01L23/22) - Y02T 10/12: Improving ICE efficiencies - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract In a control device for an internal combustion engine and a method of estimating a combustion chamber-wall temperature of an internal combustion engine of the invention, a difference between a wall temperature of the combustion chamber and a cooling water temperature is set according to an integrated value of the intake air amount of the internal combustion engine after start of the fuel-cut, and the estimated value of the wall temperature of the combustion chamber during the fuel-cut is obtained based on the difference and the cooling water temperature. ## Claims ### Claim 1 A control device for an internal combustion engine, comprising: a fuel-cut unit that performs fuel-cut for stopping supply of fuel to a combustion chamber in a deceleration operation of an internal combustion engine; a wall temperature estimating unit that estimates a wall temperature of the combustion chamber; and a combustion control unit that controls combustion of the internal combustion engine based on an estimated value of the wall temperature of the combustion chamber, the wall temperature estimating unit setting a difference between the wall temperature of the combustion chamber and a cooling water temperature according to an integrated value of an intake air amount of the internal combustion engine after start of the fuel-cut, and obtains the estimated value of the wall temperature of the combustion chamber during the fuel-cut based on the difference and the cooling water temperature. ### Claim 2 (depends on 1) The control device for an internal combustion engine according to claim 1, wherein the wall temperature estimating unit uses a difference between the estimate of the wall temperature of the combustion chamber at the time of start of the fuel-cut and the cooling water temperature as an initial value, and reduces the difference according to an increase in the integrated value. ### Claim 3 (depends on 1) The control device for an internal combustion engine according to claim 1, wherein the wall temperature estimating unit changes the estimated value of the wall temperature of the combustion chamber during the fuel-cut to a greater value as a rotational speed of the internal combustion engine is higher. ### Claim 4 (depends on 1) The control device for an internal combustion engine according to claim 1, wherein the internal combustion engine includes a variable valve device that varies opening and closing timings of an intake valve, and the wall temperature estimating unit changes the estimated value of the wall temperature of the combustion chamber during the fuel-cut to a greater value as the closing timing of the intake valve is closer to a bottom dead center. ### Claim 5 (depends on 1) The control device for an internal combustion engine according to claim 1, wherein the internal combustion engine includes a variable compression ratio device that adjusts a mechanical compression ratio by changing the volume of the combustion chamber, and the wall temperature estimating unit changes the estimated value of the wall temperature of the combustion chamber during the fuel-cut to a greater value as the mechanical compression ratio is higher. ### Claim 6 A method of estimating a combustion chamber-wall temperature of an internal combustion engine, the method comprising: a step of measuring a cooling water temperature of an internal combustion engine; a step of measuring an intake air amount of the internal combustion engine; a step of estimating a wall temperature of a combustion chamber during a combustion operation of the internal combustion engine; a step of performing fuel-cut for stopping supply of fuel to the combustion chamber in a deceleration operation of the internal combustion engine; a step of obtaining a difference between an estimated value of the wall temperature of the combustion chamber at the time of start of the fuel-cut and the cooling water temperature; a step of obtaining an integrated value of the intake air amount after the start of the fuel-cut; a step of reducing data of the difference according to an increase in the integrated value; and a step of obtaining an estimated value of the wall temperature of the combustion chamber during the fuel-cut based on a measured value of the cooling water temperature and the data of the difference. ### Claim 7 (depends on 6) The method of estimating a combustion chamber-wall temperature of an internal combustion engine according to claim 6, further comprising: a step of changing the estimated value of the wall temperature of the combustion chamber during the fuel-cut to a greater value as a rotational speed of the internal combustion engine is higher. ### Claim 8 (depends on 6) The method of estimating a combustion chamber-wall temperature of an internal combustion engine according to claim 6, wherein the internal combustion engine includes a variable valve device that varies opening and closing timings of an intake valve, and the method further comprising: a step of changing the estimated value of the wall temperature of the combustion chamber during the fuel-cut to a greater value as the closing timing of the intake valve is closer to a bottom dead center. ### Claim 9 (depends on 6) The method of estimating a combustion chamber-wall temperature of an internal combustion engine according to claim 6, wherein the internal combustion engine includes a variable compression ratio device that adjusts a mechanical compression ratio by changing the volume of the combustion chamber, and the method further comprising: a step of changing the estimated value of the wall temperature of the combustion chamber during the fuel-cut to a greater value as the mechanical compression ratio is higher.