Patent attributes
Embodiments of the invention are directed towards a trap canister for adsorbing fuel vapor contained in breakthrough gas discharged from a main adsorbent canister. The main adsorbent canister is connected to a fuel tank has a case defining an adsorption chamber therein and an adsorbent filled in the adsorption chamber. The case has a first end open to the atmosphere and a second end for introducing breakthrough gas into the adsorption chamber. The adsorbent filled in the adsorption chamber adsorbs the fuel vapor contained in the breakthrough gas. The trap canister further has a bypass path for bypassing the adsorption chamber and a valve configured to block the bypass path and to allow for opening during refueling. This prevents the fuel vapor from flowing into the atmosphere during normal operation while also decreasing pressure loss during refueling.
