US 9,593,634 B2 · Heat release rate waveform generating device and combustion state diagnostic system for internal combustion engine

Abstract

In a diesel engine, an inside of a cylinder is divided into intra-cavity and extra-cavity regions. Ideal heat release rate waveform models, each formed of an isosceles triangle in which each oblique line gradient is a reaction rate, an area is a reaction amount and a base length is a reaction period with a reaction start temperature as a base point, are generated respectively for a vaporization reaction, low-temperature oxidation reaction, thermal decomposition reaction and high-temperature oxidation reaction of injected fuel for each region. An ideal heat release rate waveform of the reaction modes is generated by smoothing the ideal heat release rate waveform models through filtering and combining the ideal heat release rate waveforms, and is compared with an actual heat release rate waveform obtained from a detected in-cylinder pressure. A reaction mode having a deviation larger than or equal to a predetermined amount is diagnosed as being abnormal.

Claims20

Dependent claims

A heat release rate waveform generating device for a compression self-ignition internal combustion engine that carries out self-ignition combustion of fuel injected from a fuel injection valve into a cylinder, the heat release rate waveform generating device comprising:

an electronic control unit configured to:
(a) divide an inside of the cylinder into an internal region inside a cavity provided in a piston and an external region outside the cavity,
(b) generate an ideal heat release rate waveform for at least one of the regions, the fuel injected from the fuel injection valve being present in the region,
(c) generate the ideal heat release rate waveform for the internal region inside the cavity when the fuel injected from the fuel injection valve is present only in the internal region inside the cavity,
(d) generate the ideal heat release rate waveform for the external region outside the cavity when the fuel injected from the fuel injection valve is present only in the external region outside the cavity, and
(e) individually generate the ideal heat release rate waveform for each of the internal region inside the cavity and the external region outside the cavity when the fuel injected from the fuel injection valve is present in both the internal region inside the cavity and the external region outside the cavity.

3 more elements

A combustion state diagnostic system for an internal combustion engine, comprising:

an electronic control unit configured to:
(a) divide an inside of a cylinder into an internal region inside a cavity provided in a piston and an external region outside the cavity,
(b) generate an ideal heat release rate waveform for at least one of the regions, fuel injected from a fuel injection valve being present in the region,
(c) generate the ideal heat release rate waveform for the internal region inside the cavity when the fuel injected from the fuel injection valve is present only in the internal region inside the cavity,
(d) generate the ideal heat release rate waveform for the external region outside the cavity when the fuel injected from the fuel injection valve is present only in the external region outside the cavity,
(e) individually generate the ideal heat release rate waveform for each of the internal region inside the cavity and the external region outside the cavity when the fuel injected from the fuel injection valve is resent in both the internal region inside the cavity and the external region outside the cavity,
(f) generate the ideal heat release rate waveform by calculating a reaction rate, a reaction amount and a reaction period of each of a plurality of reactions of the fuel injected from the fuel injection valve for the at least one of the internal region inside the cavity and the external region outside the cavity, the injected fuel being present in the region, on the basis of an environment in the region,
(g) compare the ideal heat release rate waveform with an actual heat release rate waveform at a time when the fuel has actually reacted in the cylinder in each of the reactions, and
(h) diagnose that there is an abnormality in the reaction when there is the reaction in which a deviation of the actual heat release rate waveform from the ideal heat release rate waveform is larger than or equal to a predetermined amount.

6 more elements

Dependencies are inferred from the claim text.

Heat release rate waveform generating device and combustion state diagnostic system for internal combustion engine

Life of this patent

Heat release rate waveform generating device and combustion state diagnostic system for internal combustion engine

Life of this patent

Abstract

Claims20