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AssigneesHitachi, Ltd., Hitachi Car Engineering Co., Ltd.
InventorsYoshiyuki Yoshida, Hidefumi Iwaki, Toshio Hori, Kentarou Shiga, Yoshikuni Kurashima
Estimating the term…
In a direct injection engine capable of reducing an amount of NOx discharged as much as possible, realizing EGR in a large amount, and enlarging a stable burning limit, fuel injection valves for directly injecting fuel into combustion chambers are arranged, ignition plugs are provided in the combustion chambers to face the same, intake ports for generating a tumble gas flow in the combustion chambers are provided. The intake ports are compartmented by partitions into high velocity port portions having a high flow velocity of intake air and low velocity port portions having a low flow velocity of intake air, passage valves for opening and closing the port portions are arranged near upstream ends of the low velocity port portions, and an EGR passage for introducing an EGR gas is connected to the low velocity port portions.
A direct injection engine comprising intake ports for supplying an air and an EGR gas to combustion chambers, fuel injection valves directly injecting a fuel, and ignition plugs, and wherein the air and the EGR gas are supplied to the combustion chambers such that the air having a large flow velocity and the EGR gas having a small flow velocity generate a tumble gas flow so as to provide a state of distribution, in which near the ignition plugs, an air-fuel ratio is on a rich side with a less fresh air and a much EGR gas, and with distance from the ignition plugs, the air-fuel ratio comes to a lean side with a much fresh air and a less EGR gas.
A direct injection engine, comprising combustion chambers in which are arranged fuel injection valves directly injecting a fuel and ignition plugs, and intake ports configured to generate a tumble gas flow composed of an air and an EGR gas in the combustion chambers, and partitions compartmenting the respective intake ports into a high velocity port portion having a high intake flow velocity and a low velocity port portion having a low intake flow velocity, wherein passage valves for opening and closing the port portions are arranged near upstream ends of the low velocity port portions so as to generate a negative pressure in the low velocity port portions, and EGR passages for introduction of the EGR gas are connected to the low velocity port portions.
A method of effecting stratified charge combustion in a direct injection engine, in which an air and an EGR gas are supplied to combustion chambers and a fuel is directly injected into the combustion chambers, the method comprising the step of effecting stratified charge combustion by producing through a tumble gas flow a state of distribution, in which near ignition plugs in the combustion chambers, an air-fuel ratio is on a rich side with a less fresh air and a much EGR gas, and with distance from the ignition plugs, the air-fuel ratio comes to a lean side with a much fresh air and a less EGR gas.
Dependencies are inferred from the claim text.