Patent ID: 7350399
Filing Date: 2008-04-01
Classification: F02M

Abstract:
1. A leakage detecting device for an evaporating fuel processing apparatus, the leakage detecting device detecting leakage of evaporating fuel in a ventilation apparatus that includes a fuel tank and a filter, the filter absorbing fuel evaporating in the fuel tank, the leakage detecting device comprising: an electric pump that includes a motor portion and a pump portion for generating at least one of pressurizing force and de-pressurizing force, wherein the electric pump produces a pressure difference between an inside of the ventilation apparatus and an outside of the ventilation apparatus in accordance with said at least one of pressurizing force and de-pressurizing force to detect a leakage condition of the ventilation apparatus, the leakage detecting device further comprising: rotation speed controlling means for controlling rotation speed of the motor portion; a pressure detecting means that is connected between the electric pump and the fuel tank, and is adapted to detecting pressure in the ventilation apparatus and the pressure difference; and a reference detecting means for detecting a reference pressure difference which is produced using the electric pump to generate the at least one of pressurizing force and de-pressurizing force through a reference orifice, wherein the rotation speed controlling means detects rotation speed of the motor portion, and the rotation speed controlling means corrects the rotation speed of the motor portion such that the reference pressure difference coincides with a predetermined pressure difference, and the leakage detecting device further comprising: rotation speed storing means for storing the rotation speed of the motor portion, which is corrected by the rotation speed controlling means, as a detecting rotation speed, wherein the rotation speed of the motor portion is controlled at the detecting rotation speed when the leakage condition of the ventilation apparatus is detected.