# US 2018/0023503 A1 · Control device for 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 2018/0023503 A1 - Document ID: US20180023503A1 - Status: Published application - Kind: A1 - Application number: 15/547,973 - Filed: 2016-01-29 - Published: 2018-01-25 - Earliest claimed: 2015-02-05 - Assignees: Hitachi Automotive Systems, Ltd. - Applicants: Hitachi Automotive Systems, Ltd. - Inventors: Shingo KIMURA; Tomoaki HORII; Mitsuru NAGASE; Shirou YAMAOKA; Ryo KUSAKABE; Takaki ITAYA - Web page: https://patentgrep.com/patent/US20180023503A1 ## CPC - F02D 41/40: with means for controlling injection timing or duration - F02D 41/20: Output circuits, e.g. for controlling currents in command coils - F02D 41/402: {Multiple injections} - F02D 41/26: using computer, e.g. microprocessor - F02D 2041/2003: {using means for creating a boost voltage, i.e. generation or use of a voltage higher than the battery voltage, e.g. to speed up injector opening} - F02D 2041/2051: {using voltage control} - F02D 2041/2058: {using information of the actual current value} - F02D 2200/0602: Fuel pressure - F02D 2200/50: said parameters being related to the vehicle or its components - F02M 69/046: {for injecting into both the combustion chamber and the intake conduit} - Y02T 10/40: Engine management systems - 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) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract Provided is a control device for an internal combustion engine, the control device enabling the suppression of variations in the amount of fuel injected by injection while the boost voltage is charging, without offsetting the injection timing. A boost circuit (211) boosts a first voltage supplied from a battery (201), and supplies a boosted second voltage to a fuel injection device (214). Switches (212, 213) switch the second voltage supplied to the fuel injection device from the booster circuit on and off. Computation devices (204, 207) control the switches. Each computation device comprises: an estimation unit that, before the initial fuel injection in a combustion cycle, estimates the second voltage for all of the fuel injection times in the combustion cycle; and a correction unit that corrects the amount of fuel injected for each fuel injection time depending on the estimated second voltage. ## Claims ### Claim 1 A control device for an internal combustion engine, the control device comprising: a boost circuit which boosts a first voltage supplied from a battery and supplies a boosted second voltage to a fuel injection device; a switch which turns the second voltage supplied from the boost circuit to the fuel injection device on and off; and a computation device which controls the switch, wherein the computation device includes: an estimation unit which estimates the second voltage at all fuel injection timings during one combustion cycle, before the initial fuel injection during the one combustion cycle; and a correction unit which corrects a fuel injection quantity at each fuel injection timing depending on the estimated second voltage. ### Claim 2 (depends on 1) The control device for the internal combustion engine according to claim 1, wherein the estimation unit estimates the second voltage at all the fuel injection timings during the one combustion cycle for all cylinders, before the initial fuel injection during one combustion cycle of a certain cylinder. ### Claim 3 (depends on 1) The control device for the internal combustion engine according to claim 1, wherein the estimation unit estimates the second voltage at the fuel injection timing, based on the quantity of electric power supplied to the boost circuit, the quantity of electric power consumed when the fuel injection device performs the fuel injection once, and the number of times of fuel injection during the one combustion cycle. ### Claim 4 (depends on 1) The control device for the internal combustion engine according to claim 1, wherein the estimation unit estimates the second voltage at the fuel injection timing, based on the second voltage at a predetermined timing before the initial fuel injection during the one combustion cycle, a rate of change in the second voltage when the fuel injection device performs the fuel injection once, a rate of change in the second voltage when the boost circuit is charged after the fuel injection device performs the fuel injection once, and the number of times of fuel injection during the one combustion cycle. ### Claim 5 (depends on 1) The control device for the internal combustion engine according to claim 1, wherein the estimation unit estimates the second voltage at the fuel injection timing, based on a boosted voltage drop quantity indicating a drop quantity of the second voltage when the fuel injection device performs the fuel injection once in a state in which the boost circuit is fully charged, the time to reach a peak current which is a maximum value of the drive current after the drive current is supplied to the fuel injection device, a restoration reference time indicating the time until the boost circuit is fully charged after the second voltage starts to drop when the fuel injection device performs the fuel injection once in a state in which the boost circuit is fully charged, and the number of times of fuel injection during the one combustion cycle. ### Claim 6 (depends on 1) The control device for the internal combustion engine according to claim 1, wherein the estimation unit sets the restoration reference time depending on the first voltage and the temperature of the control device. ### Claim 7 (depends on 6) The control device for the internal combustion engine according to claim 6, wherein the temperature of the control device is a substrate temperature of the control device or the temperature of the boost circuit. ### Claim 8 (depends on 6) The control device for the internal combustion engine according to claim 6, wherein the estimation unit sets the restoration reference time, depending on the averaged value of the first voltage. ### Claim 9 (depends on 6) The control device for the internal combustion engine according to claim 6, wherein the estimation unit sets the restoration reference time so that the restoration reference time increases as the first voltage decreases, and the estimation unit sets the restoration reference time so that the restoration reference time increases as the temperature of the control device increases. ### Claim 10 (depends on 1) The control device for the internal combustion engine according to claim 1, wherein the correction unit performs correction to increase the fuel injection pulse width, in a case where the estimated second voltage is smaller than a reference voltage indicating the voltage when the boost circuit is fully charged. ### Claim 11 (depends on 10) The control device for the internal combustion engine according to claim 10, wherein the reference voltage is a voltage of the boost circuit which is measured before the fuel injection device injects fuel, after turning an ignition switch from off to on. ### Claim 12 (depends on 1) The control device for the internal combustion engine according to claim 1, wherein the correction unit performs correction to decrease the fuel injection pulse width, in a case where the second voltage is larger than the reference voltage indicating the voltage when the boost circuit is fully charged.