Engine fuel vapor treating apparatus

An apparatus for treating fuel vapor generated in a fuel tank, said apparatus having a canister which has a vapor inlet communicating with the tank, a vapor outlet communicating with an engine by way of a purge line and an air intake passage, a gas outlet communicating with the atmosphere and an adsorbent layer member which has a plurality of adsorbents, wherein the fuel vapor is introduced to the canister through the vapor inlet, fuel components contained in the fuel vapor are collected by the adsorbent layer member and residual gas of the fuel vapor is discharged to the atmosphere through the gas outlet, and wherein the collected fuel components are purged into the air intake passage through the vapor outlet and the purge line during an operation of the engine, said apparatus comprising:

• a breather line for introducing the fuel vapor massively generated in the tank when the fuel is supplied to the tank;
• a partition means for defining a plurality of chambers in the canister;
• said partition means having a plurality of holes for the communication of the chambers with each other;
• said adsorbent layer member being divided by the partition means into two separated layers;
• each of said holes having an inner diameter smaller than a smallest diameter of the adsorbents;
• and
• said breather line having an area in cross section at most identical to the total area of the holes.

An apparatus for treating fuel vapor generated in a fuel tank, said apparatus having a canister which has a vapor inlet communicating with the tank, a vapor outlet communicating with an engine by way of a purge line and an air intake passage, a gas outlet communicating with the atmosphere and an adsorbent layer member which has a plurality of adsorbents, wherein the fuel vapor is introduced to the canister through the vapor inlet, fuel components contained in the fuel vapor are collected by the adsorbent layer member and residual gas of the fuel vapor is discharged to the atmosphere through the gas outlet, and wherein the collected fuel components are purged into the air intake passage through the vapor outlet and the purge line during an operation of the engine, said apparatus comprising:

• a breather line for introducing the fuel vapor massively generated in the tank when the fuel is supplied to the tank;
• a partition means for defining a plurality of chambers in the canister;
• said partition means having a plurality of holes for the communication of the chambers with each other;
• said adsorbent layer member being divided by the partition means into two separated layers;
• each of said holes being formed in an elliptical shape having a minor axis smaller than a smallest diameter of the adsorbents and a major axis substantially equal to a length of the partition means;
• and
• said breather line having an area in cross section at most identical to the total area of the holes.