Fuel vapor processors

Abstract

A fuel vapor processor has a fuel tank, a canister, a vapor pipe, a recovery pipe, an air pipe, a suction device, a vapor pipe valve, an air pipe valve, and a pressure regulator. The vapor pipe leads fuel vapor generated in the fuel tank to the canister for trapping the fuel vapor in the canister. The recovery pipe recoveries the fuel vapor desorbed from the canister into the fuel tank. The air pipe communicates the canister with the atmosphere. The suction device is disposed on the recovery pipe for desorbing the fuel vapor trapped in the canister. The pressure regulator is communicated with the air pipe between the air pipe valve and the canister in order to allow gas flow from the atmosphere toward the canister. During desorption of the fuel vapor due to the suction device, the vapor pipe valve and the air pipe valve are closed, and negative pressure is kept in the canister such that the fuel vapor is desorbed from the canister and fresh air is led into the canister via the pressure regulator.

Dependencies are inferred from the claim text.