| 主权项 |
1. A fuel vapor processing apparatus comprising:
a main canister having a main canister case, at least a first adsorption chamber defined in the main canister on an outlet side, and a first adsorption material contained in the first adsorption chamber; a trap canister having a trap case having a second adsorption chamber defined therein and containing a second adsorption material, the second adsorption chamber communicating with the first adsorption chamber of the main canister, so that break-through gas discharged from the first adsorption chamber is introduced into the second adsorption chamber and flows through the second adsorption material in a gas flow direction; wherein:
the second adsorption chamber includes a gas introduction side and a gas outlet side located downstream of the gas introduction side along the gas flow direction;the trap case comprises an introduction side tubular portion having a gas introduction port connected to an outlet of the main canister, an outlet side tubular portion having a gas outlet port open to an atmosphere, and an intermediate tubular portion, wherein the introduction side tubular portion is in communication with the outlet side tubular portion through the intermediate tubular portion;each of the introduction side tubular portion and the outlet side tubular portion has a respective passage cross sectional area that is substantially uniform and unvarying along the gas flow direction, wherein the passage cross sectional area of the outlet side tubular portion is smaller than the passage cross sectional area of the introduction side tubular portion;the intermediate tubular portion is tapered such that a passage cross sectional area of the intermediate tubular portion gradually decreases from the introduction side tubular portion toward the outlet side tubular portion; a first partition member disposed within the introduction side tubular portion at the introduction side of the second adsorption chamber; and second partition member disposed within the outlet side tubular portion at the outlet side of the second adsorption chamber; wherein each of the first partition member and the second partition member has a gas permeability, and wherein the first partition member is freely movable within the trap case in the gas flow direction toward the second partition member; a temperature control device configured to control a temperature of the second adsorption material; wherein the first adsorption material has a first fuel adsorption ability; and wherein the second adsorption material has a second fuel adsorption ability higher than the first fuel adsorption ability. |
