Methodology of Minimum Energy Starting for SI Engine

In a general purpose of small SI engine, it is required to reduced fuel consumption under the operating conditions of repeated start and stop. In other words, the energy distribution during starting from 0 rpm to idling speed is an important factor of information. The SI engine needs to be driven by the motor at the starting, and its electrical energy must be minimized. However, the engine itself needs to accelerate during starting, and its electrical energy is affected by compression, friction and moments of inertia. The purpose of this research is to clarify experimentally the starting condition that minimizes this electrical energy. This research has made it possible to divide and measure the frictional and compressional loss and the loss due to the moment of inertia during engine acceleration. Specifically, the effect of the moment of inertia was eliminated by using a motor to keep the engine in a constant state of rotation. This allows the electrical energy used by friction to be determined. The electrical energy used by the moment of inertia can also be determined by comparing it to the electrical energy used when the engine is started from a stopped state. Moreover, the effect of compression can be evaluated with the moment of inertia and friction of each engine parts. The way of minimum energy starting of small engine will be suggested in this research.