Mazda Motor Corporat Ion

Mazda Motor Corporation

Takashi Kohata

Kouji Shishime

Taiki Maiguma

Daisuke Tanaka

Yuichiro Tsumura

Hidetoshi Hashimoto

An engine system includes a combustion chamber including a cylinder, a fuel supply that supplies fuel including gasoline into the combustion chamber, circuitry configured to predict a knock will occur in the combustion chamber, and a fluid injector that injects a fluid into the combustion chamber. Further, there is circuitry configured to suppress a knock by instructing the fluid injector, when the knock is predicted to occur by the circuitry configured to predict, to inject the fluid into the combustion chamber within a period before a burned mass fraction reaches 50% after a start of combustion.

Engine system and method for suppressing knock

A method and system for predicting the occurrence of a knock which will have a predetermined intensity or higher (intense knock) in an engine that burns an air-fuel mixture of gasoline fuel. The pressure in a combustion chamber is detected during an initial stage of combustion. This pressure is compared with a preset reference value to determine whether or not the cylinder inner pressure exceeds the reference value during the combustion. When the cylinder inner pressure exceeds the reference value, it is predicted that the intense knock will occur before an end of the combustion. If the intense knock is predicted, additional fuel or other material can be injected into the combustion chamber to prevent the occurrence of the intense knock.

Method for predicting knock, method for suppressing knock, and engine system

A control device for an engine is provided, which includes a knock intensity sensor configured to detect a knock intensity, an output adjustment mechanism configured to adjust an engine output torque, and a controller configured to control the output adjustment mechanism based on the knock intensity. The controller executes a first control in which the output adjustment mechanism is controlled to reduce the knock intensity when the number of strong knocks that is the number of times the knock intensity becomes a second determination intensity or greater is a given determination number or less and when the knock intensity is greater than a first determination intensity, and executes a second control in which the output adjustment mechanism is controlled to reduce the maximum torque more than when the number of strong knocks is the determination number or less, when the number of strong knocks is greater than the determination number.

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Hatsukaichi, Japan

Takashi Kohata