# US 2014/0190447 A1 · Control system for a multi-fuel 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 2014/0190447 A1
- Document ID: US20140190447A1
- Status: Published application
- Kind: A1
- Application number: 14/240,093
- Filed: 2011-08-24
- Published: 2014-07-10
- Earliest claimed: 2011-08-24
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Inventors: Masahiko MASUBUCHI
- Web page: https://patentgrep.com/patent/US20140190447A1

## CPC

- F02D 41/403: {with pilot injections}
- F02D 13/0238: {by shifting the phase, i.e. the opening periods of the valves are constant}
- F02D 19/024: {by controlling fuel injectors}
- F02D 19/0647: {the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME]}
- F02D 19/0692: {Arrangement of multiple injectors per combustion chamber}
- F02D 19/081: {Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other}
- F02D 41/0025: {Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures}
- F02D 41/1475: {Regulating the air fuel ratio at a value other than stoichiometry}
- F02D 41/30: Controlling fuel injection {(F02D41/182, F02D41/24 take precedence)}
- F02D 41/0027: {the fuel being gaseous (non-electrical control F02D19/02)}
- F02D 2200/0611: Fuel type, fuel composition or fuel quality
- F02D 2200/101: Engine speed
- F02D 2200/1015: Engines misfires
- Y02T 10/12: Improving ICE efficiencies
- Y02T 10/30: Use of alternative fuels, e.g. biofuels
- 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

The present invention is intended to suppress generation of a misfire and an increase in the amount of emission of HC, in a multi-fuel internal combustion engine of compression ignition type using, as fuels, a liquid fuel which can be ignited by compression and a gas fuel which is lower in ignitability than the liquid fuel. In the invention, in the same operating state, in cases where the liquid fuel and the gas fuel are caused to combust with the liquid fuel being used as an ignition source, the equivalent ratio of a mixture in a cylinder is made to increase, in comparison with the case where only the liquid fuel is caused to combust, and the rate of the increase of the equivalent ratio with respect to the case where only the liquid fuel is caused to combust is made smaller, when an engine load is low in comparison with the time when the engine load is high, and when an engine rotational speed is low in comparison with the time when the engine rotational speed is high.

## Claims

### Claim 1

A control system for a multi-fuel internal combustion engine of compression ignition type which uses a liquid fuel being able to be ignited by compression, and a gas fuel being lower in ignitability than the liquid fuel,
wherein an equivalent ratio control unit is provided which increases an equivalent ratio of a mixture in a cylinder, in the same operating state, in cases where the liquid fuel and the gas fuel are caused to combust with the liquid fuel being used as an ignition source, the equivalent ratio of a mixture in a cylinder is made to increase, in comparison with the case where only the liquid fuel is caused to combust, and the rate of the increase of the equivalent ratio with respect to the case where only the liquid fuel is caused to combust is made smaller, when an engine load is low in comparison with the time when the engine load is high, and when an engine rotational speed is low in comparison with the time when the engine rotational speed is high.

### Claim 2 (depends on 1)

The control system for a multi-fuel internal combustion engine as set forth in claim 1, wherein when the engine load is equal to or less than a prescribed load and the engine rotational speed is equal to or less than a prescribed rotational speed, in cases where the liquid fuel and the gas fuel are caused to combust, said equivalent ratio control unit decreases the equivalent ratio of the mixture in the cylinder, as compared with the case where only the liquid fuel is caused to combust.

### Claim 3 (depends on 1)

The control system for a multi-fuel internal combustion engine as set forth in claim 1, further comprising:
a composition detection unit that detects a composition of the gas fuel;
wherein in cases where the liquid fuel and the gas fuel are caused to combust, said equivalent ratio control unit changes a rate of increase at the time of increasing the equivalent ratio of the mixture in the cylinder more than in the case where only the liquid fuel is caused to combust, in accordance with the composition of the gas fuel detected by said composition detection unit.

### Claim 4 (depends on 2)

The control system for a multi-fuel internal combustion engine as set forth in claim 2, further comprising:
a composition detection unit that detects a composition of the gas fuel;
wherein in cases where the liquid fuel and the gas fuel are caused to combust with the liquid fuel being used as the ignition source, said equivalent ratio control unit changes a rate of increase or a rate of decrease at the time of increasing or decreasing the equivalent ratio of the mixture in the cylinder more than in the case where only the liquid fuel is caused to combust, in accordance with the composition of the gas fuel detected by said composition detection unit.