# US 8,464,687 B2 · Control device for compressed self-ignition type 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 8,464,687 B2 - Document ID: US8464687B2 - Status: Granted - Kind: B2 - Application number: 13/318,558 - Filed: 2010-04-21 - Published: 2012-03-08 - Granted: 2013-06-18 - Earliest claimed: 2009-05-12 - Assignees: Hitachi Automotive Systems, Ltd. - Applicants: Hiromu Kakuya; Kengo Kumano; Shiro Yamaoka - Inventors: Hiromu Kakuya; Kengo Kumano; Shiro Yamaoka - Web page: https://patentgrep.com/patent/US8464687B2 ## CPC - F02D 41/3035: {a mode being the premixed charge compression-ignition mode} - F02D 41/3064: {with special control during transition between modes} - F02D 41/3076: {with special conditions for selecting a mode of combustion, e.g. for starting, for diagnosing} - F02B 1/12: with compression ignition (with fuel-air charge ignited by compression ignition of an additional fuel F02B7/00) - F02B 23/104: {the injector being placed on a side position of the cylinder} - F02B 2075/125: {Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber} - F02D 13/0253: {Fully variable control of valve lift and timing using camless actuation systems such as hydraulic, pneumatic or electromagnetic actuators, e.g. solenoid valves} - F02D 41/1454: {the characteristics being an oxygen content or concentration or the air-fuel ratio} - Y02T 10/12: Improving ICE efficiencies - 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) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An object is to provide a control device and control method for a compressed self-ignition type internal combustion engine, which can reduce torque variation due to misfire when the air-fuel ratio varies during compressed self-ignition type combustion, and thereby effectively use the potential for reducing fuel consumption. As the combustion mode, a spark-ignition type combustion mode by use of an ignition plug and a compressed self-ignition type combustion mode which utilizes a pressure increase in a combustion chamber in association with upward movement of piston are selectively set depending on an operational state of the engine, and when the air-fuel ratio in the compressed self-ignition type combustion mode is rich, a regional upper limit of the compressed self-ignition type combustion region is changed toward the lower engine torque side, and when the air-fuel ratio is lean, the regional upper limit is changed toward the higher engine torque side. ## Claims ### Claim 1 A control device for a compressed self-ignition type internal combustion engine, for use in an internal combustion engine having: an injector for directly injecting fuel into a combustion chamber; and an ignition device for igniting the fuel injected into the combustion chamber, the control device for a compressed self-ignition type internal combustion engine being configured such that a spark-ignition type combustion mode in which fuel sprayed from the injector is ignited by the ignition device to burn the fuel to actuate the internal combustion engine, and a compressed self-ignition type combustion mode, in which the fuel injected from the injector is caused to burn by a pressure rise in association with upward movement of a piston making up the combustion chamber, are switched depending on whether or not the working state of the internal combustion engine is in a compressed self-ignition type combustion region in which the compressed self-ignition type combustion mode is stably performable, which is determined by a torque and an engine rotational speed, and that when an air-fuel ratio which is a mass ratio between an air quantity and a fuel quantity introduced into the combustion chamber while the compressed self-ignition type combustion mode is performed is richer than a predetermined value, an upper limit of torque of the compressed self-ignition type combustion region is changed toward a direction in which the upper limit decreases, and that when the air-fuel ratio is richer than the predetermined value while the compressed self-ignition type combustion mode is performed, and there is a demand for increasing torque to be not less than an upper limit of the compressed self-ignition type combustion region while the compressed self-ignition type combustion mode is performed, the torque is increased in a spark-ignition type combustion mode, after the torque is increased in the compressed self-ignition type combustion mode with a quantity of torque to be increased in the compressed self-ignition type combustion mode being decreased to be less than a quantity of torque to be increased when the air-fuel ratio is the predetermined value with reference to torque before there is the demand for increasing the torque. ### Claim 2 (depends on 1) The control device for a compressed self-ignition type internal combustion engine according to claim 1, wherein the air-fuel ratio is determined based on an output signal of a sensor for detecting air-fuel ratio, which is provided in the downstream of the exhaust valve. ### Claim 3 (depends on 1) The control device for a compressed self-ignition type internal combustion engine according to claim 1, wherein the air-fuel ratio is determined based on an output signal of any one of sensors provided in the internal combustion engine, including: a sensor for measuring a flow rate of air passing through an intake pipe; a sensor for measuring pressure in an intake pipe; a sensor for measuring temperature of airflow quantity that flows into the combustion chamber; a sensor for measuring an atmospheric pressure; a sensor for measuring an engine temperature of the internal combustion engine; a sensor for measuring a flow rate of the fuel that flows through the injector; and a sensor for measuring pressure to be applied to the fuel to inject the fuel from the injector. ### Claim 4 (depends on 1) The control device for a compressed self-ignition type internal combustion engine according to claim 1, wherein when the air-fuel ratio while the compressed self-ignition type combustion mode is performed is leaner than the predetermined value, the upper limit of torque of the compressed self-ignition type combustion region is changed toward a direction in which the upper limit increases. ### Claim 5 A control device for a compressed self-ignition type internal combustion engine, for use in an internal combustion engine having: an injector for directly injecting fuel into a combustion chamber; and an ignition device for igniting the fuel injected into the combustion chamber, the control device for a compressed self-ignition type internal combustion engine being configured such that a spark-ignition type combustion mode in which fuel sprayed from the injector is ignited by the ignition device to burn the fuel to actuate the internal combustion engine, and a compressed self-ignition type combustion mode, in which the fuel injected from the injector is caused to burn by a pressure rise in association with upward movement of a piston making up the combustion chamber, are switched depending on whether or not the working state of the internal combustion engine is in a compressed self-ignition type combustion region in which the compressed self-ignition type combustion mode is stably performable, which is determined by a torque and an engine rotational speed, and that when an air-fuel ratio which is a mass ratio between an air quantity and a fuel quantity introduced into the combustion chamber while the compressed self-ignition type combustion mode is performed is richer than a predetermined value, an upper limit of torque of the compressed self-ignition type combustion region is changed toward a direction in which the upper limit decreases, and that when the air-fuel ratio is leaner than the predetermined value while the compressed self-ignition type combustion mode is performed, and there is a demand for increasing torque to be not less than an upper limit of the compressed self-ignition type combustion region while the compressed self-ignition type combustion mode is performed, torque is increased in the spark-ignition type combustion mode, after torque is increased in the compressed self-ignition type combustion mode with a quantity of torque to be increased in the compressed self-ignition type combustion mode being increased to be more than a quantity of torque to be increased when the air-fuel ratio is the predetermined value with reference to torque before there is the demand for increasing the torque. ### Claim 6 A control device for a compressed self-ignition type internal combustion engine, for use in an internal combustion engine having: an injector for directly injecting fuel into a combustion chamber; and an ignition device for igniting the fuel injected into the combustion chamber, the control device for a compressed self-ignition type internal combustion engine being configured such that a spark-ignition type combustion mode in which fuel sprayed from the injector is ignited by the ignition device to burn the fuel to actuate the internal combustion engine, and a compressed self-ignition type combustion mode, in which the fuel injected from the injector is caused to burn by a pressure rise in association with upward movement of a piston making up the combustion chamber, are switched depending on whether or not the working state of the internal combustion engine is in a compressed self-ignition type combustion region in which the compressed self-ignition type combustion mode is stably performable, which is determined by a torque and an engine rotational speed, and that when an air-fuel ratio which is a mass ratio between an air quantity and a fuel quantity introduced into the combustion chamber while the compressed self-ignition type combustion mode is performed is richer than a predetermined value, an upper limit of torque of the compressed self-ignition type combustion region is changed toward a direction in which the upper limit decreases, and that when the air-fuel ratio while the compressed self-ignition type combustion mode is performed is richer than the predetermined value, and there is a demand for increasing torque to be not less than an upper limit of the compressed self-ignition type combustion region while the compressed self-ignition type combustion mode is performed, torque is increased in the spark-ignition type combustion mode, after torque is increased in the compressed self-ignition type combustion mode with a period during which the torque is increased in the compressed self-ignition type combustion mode being reduced with reference to a period during which the compressed self-ignition type combustion mode is continued before there is the demand for increasing torque. ### Claim 7 A control device for a compressed self-ignition type internal combustion engine, for use in an internal combustion engine having: an injector for directly injecting fuel into a combustion chamber; and an ignition device for igniting the fuel injected into the combustion chamber, the control device for a compressed self-ignition type internal combustion engine being configured such that a spark-ignition type combustion mode in which fuel sprayed from the injector is ignited by the ignition device to burn the fuel to actuate the internal combustion engine, and a compressed self-ignition type combustion mode, in which the fuel injected from the injector is caused to burn by a pressure rise in association with upward movement of a piston making up the combustion chamber, are switched depending on whether or not the working state of the internal combustion engine is in a compressed self-ignition type combustion region in which the compressed self-ignition type combustion mode is stably performable, which is determined by a torque and an engine rotational speed, and that when an air-fuel ratio which is a mass ratio between an air quantity and a fuel quantity introduced into the combustion chamber while the compressed self-ignition type combustion mode is performed is richer than a predetermined value, an upper limit of torque of the compressed self-ignition type combustion region is changed toward a direction in which the upper limit decreases, and that when the air-fuel ratio is leaner than the predetermined value while the compressed self-ignition type combustion mode is performed, and there is a demand for increasing torque to be not less than an upper limit of the compressed self-ignition type combustion region while the compressed self-ignition type combustion mode is performed, the torque is increased in the spark-ignition type combustion mode, after torque is increased in the compressed self-ignition type combustion mode with a period during which torque is increased in the compressed self-ignition type combustion mode being extended with reference to a period during which the compressed self-ignition type combustion mode is continued before there is the demand for increasing the torque.