摘要 |
A liquid passage communicates a first reservoir of a main tank with a second reservoir storing a liquid supplied from the first reservoir, and has one end portion on the side communicating with the first reservoir, which joins with or detach from the main tank. To increase the liquid volume in the second reservoir up to a first predetermined volume, a controller feeds the liquid in the first reservoir to the second reservoir when the liquid volume in the second reservoir is less than a second predetermined volume. When the liquid volume in the second reservoir falls short of the first predetermined volume, the end portion of the liquid passage is detached from the main tank. Then, the controller determined whether the liquid volume in the second reservoir is equal to or more than the first predetermined volume. |