Mazda Motor Corporation

Yasushi Murakami

Keiji Araki

Noriyuki Ota

Masahiko Fujimoto

Kazuya Yokota

Noriyuki Ohta

There is provided a method for starting a spark ignition engine having multiple cylinders. The method may comprise supplying air and fuel for restart into a first cylinder before said engine completely stops, and igniting the mixture of said air and said fuel in said first cylinder in response to an engine restart request, wherein said first cylinder is on an expansion stroke when said engine stops. The method may also include, after said piston in said first cylinder starts moving, injecting fuel into a second cylinder that is on a compression stroke when said engine stops, on a compression stroke where a piston of said second cylinder is moving in a direction opposite to an operative direction of said piston in said first cylinder.

Method of starting spark ignition engine without using starter motor

There is provided a method of starting a spark ignition engine having multiple cylinders. The method comprises supplying air and fuel for restart into a first cylinder before the engine completely stops, and igniting the mixture of the air and the fuel in the first cylinder in response to an engine start request. In accordance with the method, by supplying air and fuel into the first cylinder before the engine completely stops, the mixture of air and fuel in the first cylinder may be homogeneous at the time of the engine start request. Also, there may be less mixture turbulence and combustion may propagate better within the cylinder. These conditions may reduce the rate of combustion in the first cylinder after a start request is initiated. The slower combustion rate may decrease temperature of the combusted gas while the cylinder wall temperature is relatively low because the engine has stopped. As a result, the slower combustion may reduce heat loss in the first cylinder because of the smaller difference between the temperatures of the combusted gas and the cylinder wall. Consequently, more energy may be directed from the first cylinder to the crankshaft, so that the engine restart becomes more reliable.

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Hiroshima, Japan

Yasushi Murakami