Patent ID: 8751174
Filing Date: 2014-06-10
Classification: F02M

Abstract:
1. A method for determining the cross sectional area of a leak in the liquid-containing tank device of a vehicle, in particular of a motor vehicle, the liquid influencing the pressure in the tank device by evaporation, with the following steps: generating a first pressure as a reference pressure in the tank device at a first instant (t detecting a first pressure characteristic up to a second instant (t generating a second pressure at a third instant (t detecting a second pressure characteristic up to the fourth instant (t determining the pressure gradient of the first pressure characteristic at the second instant (t determining the first pressure difference of the pressure at the second instant (t determining the second pressure difference of the pressure at the third instant (t computing the cross sectional area of the leak depending on the determined pressure gradient and the pressure differences, based on an equation: assuming that the evaporation rate is constant in the tank device, and that a leak rate is established which is proportional to the square root of the respective pressure difference.