Fuel tank system

摘要

Provided is a fuel tank system wherein the liquid levels of fuel in two fuel storage portions can be equally maintained, and the fuel amount in each fuel tank can be estimated with a high degree of accuracy. The fuel tank system is provided with a fuel tank in which a main tank portion and a subsidiary tank portion are formed; a siphon tube which extends from the main tank portion to the subsidiary tank portion, to transfer fuel from one tank portion to the other tank portion; and an electronic control unit (ECU) for determining whether or not the fuel is transferred via the siphon tube (in the transfer state). The ECU determines that the fuel is in the transfer state when the change rate of a sender signal is equal to or less than a predetermined threshold value (VF_th).

主权项

1. A fuel tank system for a vehicle comprising:
a fuel tank in which a first fuel storage portion and a second fuel storage portion are formed,
a siphon tube that is disposed to span the first and second fuel storage portions, and transfers fuel from either of the first and second fuel storage portions to the other of the first and second fuel storage portions,a liquid level detection unit which detects a liquid level of fuel stored in one of the first and second fuel storage portions while additional fuel is being fed into one of the first and second fuel storage portions,a transfer state determination unit which determines that fuel is in a transfer state between the first and second storage portions via the siphon tube when a rate of change in a detection value of the liquid level is not more than a first predetermined threshold, which determines that fuel is not in a transfer state between the first and second storage portions via the siphon tube when a rate of change in a detection value of the liquid level is more than the first predetermined threshold, and which also estimates an amount of fuel stored in the fuel tank based on a detection value of the liquid level detection unit, anda fuel filling state determination unit for determining that fuel is being filled into the fuel tank when the vehicle is stopped, the transfer state determination unit determines that fuel is not in the transfer state, and an amount of change in the detection value of the liquid level in a predetermined period is more than a second predetermined threshold.