Abstract
The automotive electronic fuel pump is installed inside a fuel tank or on the way of a tubular fuel line due to the introduction of reduced displacement. Therefore, a small d. c. motor operating the fuel pump has a distinctive feature that its commutation is carried out in gasoline. That is to say, the commutation arc of this motor ignites in gasoline environment.
Since there are few literatures dealing with the commutation arc in liquids and some trouble with the fuel delivery system directly affect vehicle's running performance itself, it is significant to make clear properties of commutation arc in gasoline. In the previous letter, basic electrical properties of commutation arc in gasoline such as the residual current, the arc duration and the arc voltage were measured and compared with those in air. In this paper, relationship between these electrical properties is calculated with a circuit equation and is in accordance with measured values. Moreover, we conclude that a contact resistance variation before arc ignition determine the smaller residual current in gasoline and, by means of the spectroscopic measurement, hydrogen dissociated from gasoline is related to the increased arc voltage in gasoline.
