JPH06108933A - Canister - Google Patents

Abstract

PURPOSE:To prevent liquid phase fuel components from adhering to activated charcoal when the liquid phase fuel components existing in fuel vapor pass through the activated charcoal simultaneously with gas phase components during the treatment of fuel vapor in a canister. CONSTITUTION:A pipe 28 connected to a part for generating fuel vapor of a fuel tank or the like, and a pipe 27 for feeding gas, rid of harmful components by activated charcoal 25, to the intake system of an engine are provided in a container 16 filled with the activated charcoal 25 to form a canister 15. A liquid reservoir chamber 21 is formed at the upper part or lower part of the activated charcoal filled chambers 22, 23 of the container 16, in the state of being partitioned from the activated charcoal filled chambers 22, 23, and this liquid reservoir chamber 21 is communicated with the pipe 27 for feeding the gas to the intake system of the engine. Since the liquid phase fuel components are collected into this liquid reservoir chamber 21, the adhesion of liquid phase fuel components to the activated charcoal 25 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canister connected to a fuel tank or the like of an automobile.

[0002]

2. Description of the Related Art A canister connected to a fuel tank of an automobile has a structure in which a container is filled with activated carbon, and is suitable for directly discharging vaporized components such as fuel in the fuel tank to the atmosphere. It is connected to a storage part for a substance that generates a harmful component (hydrocarbon, etc.) that is not present, and the activated carbon adsorbs the harmful component to remove the harmful component generated from the fuel tank or the like.

Regarding the canister, for example, Japanese Patent Laid-Open No. 59
There are various structures as shown in Japanese Patent Publication No. 165854, but a typical one conventionally used will be described with reference to FIG. In the canister 1, 2 is a container, and wire nets 3 and 4 are provided on the upper and lower parts, and activated carbon 5 is filled between them (only a part of the activated carbon 5 is shown). The wire nets 3 and 4 may be nets of synthetic resin or the like, perforated plates, filter paper or the like.

A partition 6 is provided from the lower wire net 4 to the upper end of the container 2. This partition 6 and wire mesh 3,
The inside of the container 1 is composed of five chambers 7, 8, 9, 10,
It will be divided into 11. A pipe 12 having a tip open to the atmosphere is connected to the chamber 7, and a pipe 13 for sending a gas from which harmful components have been removed by the activated carbon 5 to the intake system of the engine and a fuel tank are connected to the chamber 8. A pipe 14 is connected to the part for generating the fuel vapor. The inner ends of these pipes 12, 13 and 14 are opened in the container 2 where they do not reach the wire mesh 3.

In the canister 1 having such a structure, when the fuel vapor from the portion for generating the fuel vapor such as the fuel tank enters the chamber 8 of the container 2 from the pipe 14, the fuel vapor is transferred to the wire mesh 3.
To enter the chamber 10 and the activated carbon 5 causes the hydrocarbon (H
Adverse components such as C) are adsorbed. The gas in which the harmful components have been adsorbed passes through the wire net 4 and enters the chamber 10 to the chamber 11, and then the chamber 10 again.
It enters and passes through the wire mesh 3, then from the chamber 8 through the pipe 13 to the intake system of the engine for combustion. When operating in this way, outside air is sucked into the container 2 from the pipe 12 that is open to the atmosphere.

When processing the fuel vapor in the canister 1,
Since a liquid-phase fuel component exists in the fuel vapor, this fuel component also passes through the activated carbon 5 at the same time as the gas-phase component. At this time, the liquid-phase fuel component may adhere to the activated carbon 5, and if it adheres, the adsorption performance of the activated carbon will be impaired. The generation of the liquid-phase fuel component in the fuel vapor is apt to occur when the temperature decreases, and when it occurs, there is no escape area, so that the fuel component gradually increases, and the performance of the canister is impaired. In addition, the engine body of the automobile will be affected, and the exhaust gas treatment and drivability will be adversely affected. Therefore, the length and shape of the pipe 14 are modified so that the fuel component in the liquid phase does not adhere to the activated carbon 5.

[0007]

The present invention has been made in view of this point, and even if the canister structure is improved by modifying the container structure of the canister without changing the length and shape of the pipe. It is an object of the present invention to provide a canister in which the liquid phase fuel component in the fuel vapor does not adhere to the activated carbon even if the liquid vapor fuel component enters the container.

[0008]

Means for Solving the Problems The present invention is, as a means for solving the above problems, a container having an inside filled with activated carbon and a pipe connected to a portion for generating fuel vapor such as a fuel tank, In a canister provided with a pipe for sending a gas from which harmful components have been removed by activated carbon to an intake system of an engine, and a pipe communicating with the atmosphere, at the upper or lower part of the activated carbon filling chamber of the container, the activated carbon filling chamber and The liquid storage chamber is partitioned to form a liquid storage chamber, and the liquid storage chamber is connected to a pipe for sending the gas to the intake system of the engine.

[0009]

According to this structure, when the fuel vapor is processed by the canister, when the liquid-phase fuel component present in the fuel vapor passes through the activated carbon at the same time as the vapor-phase component, the liquid-phase fuel component The components are stored in a liquid storage chamber which is provided separately from the activated carbon filling chamber, and therefore does not adhere to the activated carbon.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A canister 15 according to the present invention will be described below with reference to FIG. In the canister 15, 16 is a container, a plate 17 is horizontally provided at an upper portion inside thereof, and two wire nets 18 and 19 are provided at a lower portion and a portion near the bottom. A partition 20 is provided between the metal nets 18 and 19 in the vertical direction. As a result, inside the container 16, a liquid pool chamber 21 is provided above the plate 17, and the activated carbon filling chamber 2 is provided between the wire nets 18 and 19.
2, 23 are formed. The lower part of the wire net 19 becomes a chamber 24. The activated carbon filling chambers 22 and 23 are fully filled with activated carbon 25 (only a portion of the activated carbon 25 is shown). The wire nets 18 and 19 may be nets of synthetic resin or the like, perforated plates, filter papers, or the like.

At the top of the container 17, the lower end is an activated carbon filling chamber 22.
A pipe 26 whose tip is open to the atmosphere (not shown) is attached, and the lower end faces the activated carbon filling chamber 23 next to it, and the gas from which harmful components have been removed by the activated carbon 25 is supplied to the engine. Pipe for sending to the intake system of
27 is installed. In the middle of this pipe 27,
An orifice passage 27a that opens into the liquid pool chamber 21 is provided. Further, a pipe 28, the tip of which is connected to a portion for generating fuel vapor such as a fuel tank, is attached to the container 17 with its lower end facing the liquid pool chamber 21. A pipe 29 is provided between the upper part of the liquid pool chamber 21 and the activated carbon filling chamber 23 to connect them.

This canister 15 thus configured
When the fuel vapor from the fuel vapor generating portion such as the fuel tank enters the container 16 through the pipe 28, the fuel vapor enters the liquid pool chamber 21. Therefore, the liquid phase component of the fuel vapor is accumulated in the liquid pool chamber 21, and the water level thereof gradually rises. The components of the gas phase rise to the upper part in the liquid pool chamber 21 and enter the activated carbon filling chamber 23 through a pipe 29 opened at this portion. Here, the activated carbon 25 adsorbs harmful components such as hydrocarbons (HC). The gas in which the harmful components have been adsorbed passes through the wire net 19 and enters the activated carbon filling chamber 22 from the activated carbon filling chamber 23, enters the chamber 23 again, and passes through the wire net 18.
From the activated carbon filling chamber 23, this time, through the pipe 27, it is guided to the intake system of the engine and burned. When operating in this way, the outside air is sucked into the container 16 from the pipe 26 that is open to the atmosphere.

When processing the fuel vapor in the canister 15,
As described above, the liquid-phase fuel component is present in the fuel vapor and must be treated. In this embodiment, since the pipe 27 is provided with the orifice passage 27a that opens into the liquid pool chamber 21, the liquid-phase fuel component is sucked into the pipe 27 through the orifice passage 27a, and the intake system of the engine is Will be burned. As a result, the liquid-phase fuel component does not adhere to the activated carbon 25.

FIG. 2 shows another embodiment of the present invention. In this embodiment, a big difference from the above-described embodiment is that the liquid pool chamber 21 is provided in the lower portion of the container 16, more specifically, in the lower portion of the chamber 24, and therefore, the activated carbon filling chamber 23 is filled with the activated carbon. The chamber 23 is provided with a defined passage 30. The passage 30 is a chamber provided separately from the container 16.
31 and the liquid pool chamber 21 are communicated with each other, and an orifice 30a is provided at the opening in the liquid pool chamber 21. The chamber 31 is provided in the upper portion of the pipe 14 and serves to omit the pipe 13 of the embodiment shown in FIG.

The canister 15 of this embodiment thus constructed is sucked by the suction force of the purge when the liquid-phase fuel component is stored in the liquid pool chamber 21 provided at the bottom of the container 16. . The sucked liquid becomes gas due to heat or negative pressure of the engine and is purged as it is. In this embodiment, in order to prevent lowering of the adsorption efficiency and the purging efficiency, the fuel component in the liquid phase is not sucked when the suction force by the purge is small, and is sucked only when the suction force becomes large. An orifice 30a is provided at the lower end of 30. As a result, the gas-phase fuel component is less likely to be sucked from here. If a check valve 32 is provided in front of the orifice 30a of the passage 30 as shown in FIG. 3, a greater effect can be expected.

FIG. 4 shows still another embodiment of the present invention, which is a modification of that shown in FIG. In this embodiment, the liquid pool chamber 21 is integrally provided without being lowered from the chamber 24,
The orifice 30a is opened inside the liquid pool chamber 21.
There is no change in the other structures, and the functions are almost the same.

[0017]

EFFECTS OF THE INVENTION Since the present invention is the canister configured as described above, it is possible to surely prevent the fuel component in the liquid phase from adhering to the activated carbon. As a result, the durability of the canister can be improved.
Further, in connection with this, the size of the canister can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of another embodiment of the present invention.

FIG. 3 is a front view showing a partially modified example of that of FIG.

FIG. 4 is a sectional view of still another embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional canister.

[Explanation of symbols]

 15 canister 16 container 17 plate 18 wire net 19 wire net 20 partition 21 liquid pool chamber 22 activated carbon filling chamber 23 activated carbon filling chamber 24 chamber 25 activated carbon 26 pipe 27 pipe 28 pipe

Claims (1)

[Claims] 1. A container having activated carbon filled therein, a pipe connected to a portion for generating a fuel vapor such as a fuel tank, and a gas for removing harmful components by the activated carbon to send to an intake system of an engine. In a canister provided with a pipe and a pipe that communicates with the atmosphere, an upper part or a lower part of the activated carbon filling chamber of the container is formed with a liquid storage chamber that is separated from the activated carbon filling chamber, and the liquid storage chamber is filled with the gas. A canister characterized by being connected to a pipe that sends it to the intake system of the engine.