JPH07696Y2 - Canister device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a canister device for adsorbing fuel vapor generated from a fuel tank mounted on a vehicle to activated carbon in a canister.

(Prior Art) In an automobile engine, fuel vapor generated from a fuel tank is adsorbed to a canister so that the fuel vapor is not released to the atmosphere while the engine is stopped. The canister contains activated carbon (charcoal), and the activated carbon adsorbs the fuel vapor,
During operation, the fuel vapor adsorbed to the canister is purged (released) from the activated carbon by the outside air introduced from the air filter provided in the canister, and the purge air containing HC is introduced into the intake passage of the engine and burned. ing.

That is, one end of the canister body containing the activated carbon communicates with the fuel tank and the intake passage of the engine, and the other end communicates with the atmosphere. Then, the activated carbon in the canister body is charged with the fuel vapor at the time of refueling the fuel tank, and the fuel vapor is purged during operation.

(Problems to be solved by the invention) However, as described above, when purging the fuel vapor adsorbed by the activated carbon inside the canister body, the evaporation heat is removed and the activated carbon is cooled. When the activated carbon is cooled, the purging ability of the activated carbon deteriorates, and there is a drawback that the required amount cannot be purged.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a canister device that can always secure a purge amount when purging fuel vapor adsorbed on activated carbon.

[Structure of the Invention] (Means and Actions for Solving the Problems) In order to achieve the above-mentioned object, this invention adsorbs fuel vapor generated from a fuel tank mounted on a vehicle to activated carbon in a canister and In the canister device for purging the fuel vapor adsorbed on the activated carbon by the introduction, and introducing the purge air into the intake passage of the engine for combustion, a communication passage for introducing the fuel vapor generated from the fuel tank to the canister in the canister. , A purge air passage for introducing purge air into the intake passage, a first atmosphere opening portion provided with a check valve that opens when the inside of the canister has a negative pressure, and a check that opens when the inside of the canister has a positive pressure A second atmosphere opening portion provided with a valve and an engine exhaust pipe connected to the first atmosphere opening portion In that a hot air suction pipe for sucking hot air around.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

1 to 3, 1 is a vehicle body, and 2 and 2
Is the rear wheel. A fuel tank 3 is mounted between the rear wheels 2 and 2, and 4 is a fuel filler port thereof. A canister 5 is installed in the vehicle body 1 located in the vicinity of the fuel tank 3. The canister 5 contains activated carbon 6 and air filters 7, 7 are provided at both ends. Further, a communication pipe 8 and a purge air outlet pipe 9 are provided at one end of the canister 5, and the communication pipe 8 communicates with the upper part of the fuel tank 3 so that the fuel vapor generated from the fuel tank 3 is introduced into the canister 5. It has become. Further, the purge air outlet pipe 9 communicates with an intake passage (not shown) of the engine via a purge air passage (not shown) to introduce purge air into the intake passage. At the other end of the canister 5, there are provided a first communication pipe 10 as a first atmosphere opening part, a communication pipe 10 and a second communication pipe 11 as a second atmosphere opening part. The first communication pipe 10 is provided with a check valve 12 which opens only in the suction direction to the canister 5, and the second communication pipe 11 is provided with a check valve 13 which opens only in the direction protruding from the canister 5. Further, a hot air suction pipe 14 is connected to the first communication pipe 10, and the hot air suction pipe 14 communicates with a heat collecting member 16 provided on a side portion of an exhaust pipe 15 of the engine. The heat of the exhaust pipe 15 is introduced into the canister 5 via the hot air suction pipe 14, and the second communication pipe 11 is open to the atmosphere.

Therefore, according to the canister device configured as described above, when the fuel tank 3 is refueled, the fuel vapor generated from the fuel tank 3 is charged into the activated carbon 6 inside the canister 5 via the communication pipe 8. At this time, since the inside of the canister has a positive pressure, the check valve 12 of the first communication pipe 10
Is closed, and the check valve 13 of the second communication pipe 11 is open, so even if the canister 5 overflows, it is released to the atmosphere without a heat source and is safe. Further, during operation, since the intake passage of the engine has a negative pressure, the check valve 13 of the second communication pipe 11 is closed and the check valve 12 of the first communication pipe 10 is opened by the suction force. Therefore, the heat of the exhaust pipe 15 is transferred to the canister 5 via the hot air intake pipe 14.
Will be introduced to. Therefore, the hot air can heat the activated carbon to improve the purging ability.

[Effect of the Invention] As described above, according to the present invention, the first air opening portion for sucking hot air and the second air opening portion for opening when the internal pressure of the canister rises are formed. Therefore, during purging, hot air is introduced from the first atmosphere opening section to improve the purging performance, and the second atmosphere opening section is opened only when the fuel vapor with a positive pressure in the canister is adsorbed. As a result, the safety can be ensured by opening to the atmosphere without a heat source, and the purging property can be improved. Further, by heating the canister using the heat of the exhaust pipe, it is possible to constantly improve the purging ability, and it is not necessary to provide a heater or the like, which is excellent in safety.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a plan view showing a lower surface of a vehicle body, FIG. 2 is a side view of the same, and FIG. 3 is a vertical side view of a canister. .. 3 ... Fuel tank, 5 ... Canister, 6 ... Activated carbon, 14 ... Hot air suction pipe, 15 ... Exhaust pipe.

Claims (1)

[Scope of utility model registration request] 1. A fuel vapor generated from a fuel tank mounted on a vehicle is adsorbed by activated carbon in a canister,
In a canister device in which the fuel vapor adsorbed on the activated carbon is purged by the introduction of outside air and the purged air is introduced into an intake passage of an engine for combustion, a fuel vapor generated from a fuel tank is introduced into the canister to the canister. A passage, a purge air passage for introducing purge air into the intake passage, a first atmosphere opening portion provided with a check valve for opening when the inside of the canister has a negative pressure, and an opening when the inside of the canister has a positive pressure A canister comprising a second atmosphere opening portion provided with a check valve for controlling and a hot air suction pipe for sucking hot air around the exhaust pipe of the engine connected to the first atmosphere opening portion. apparatus.