Patent ID: 9422893
Filing Date: 2016-08-23
CPC Classification: F02D,F02M,Y02T

Claim Text:
1. A control method for an internal combustion engine in which selective use is made of a case where a first fuel, being easy to be ignited, is singly caused to combust, and a case where a second fuel, being hard to be ignited, is also caused to combust by igniting said first fuel, wherein the first fuel is injected in a cylinder in two steps of a pilot injection and a main injection which is carried out after the pilot injection, and the second fuel is mixed with intake air before the pilot injection of said first fuel, said method comprising: a step of acquiring a combustion state of said second fuel in the case where said second fuel is also caused to combust by igniting said first fuel, from an amount of heat generated during a time period from the pilot injection of said first fuel until the main injection of said first fuel; and a step of deciding that the combustion state of said second fuel is good, and decreasing the amount of supply of the main injection of said first fuel and at the same time increasing the amount of supply of said second fuel, in cases where the amount of generated heat during a time period from said pilot injection until said main injection acquired in the step of acquiring is equal to or more than a reference amount of generated heat, and further deciding that the combustion state of said second fuel is not good, and increasing the amount of supply of said first fuel and at the same time decreasing the amount of supply of the main injection of said second fuel, in cases where the amount of generated heat during a time period from said pilot injection until said main injection acquired in the step of acquiring is less than the reference amount of generated heat.