JPH06307299A - Evaporated fuel treatment device - Google Patents

Abstract

PURPOSE:To provide an evaporated fuel treatment device capable of forming an adherence condition in an absorber case and an activated carbon chamber and of eliminating the lowering of the working capacity of activated carbon, and having excellent evaporated fuel capture capacity. CONSTITUTION:This device is provided with an absorber case 2 filled with activated carbon 4, and separately a contact bottom plate 25 contacting the liquid trap bottom surface 140 of the activated carbon chamber 11 is provided on the bottom part of the absorber case 2. The contact bottom plate 25 is provided with a middle hole and a peripheral hole, and plural slits are provided on an annular link part between both the sides. A space between the end part of the skirt part 21 of the absorber case 2 forming a vapour transit passage and the bottom surface of the activated carbon chamber 11, and a space between the contact bottom plate 25 and the liquid trap bottom surface 140 can be made in a tightly contact state by the slits.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporated fuel processing device such as a canister attached to a fuel tank of an automobile.

[0002]

2. Description of the Related Art A relatively large amount of fuel evaporates when fuel is supplied to a fuel tank of an automobile by a fuel gun.
Further, the fuel in the fuel tank and the carburetor float chamber is partially vaporized both when the vehicle is running and when it is stopped. Therefore, in order to prevent these evaporated fuels from leaking to the atmosphere, an evaporated fuel processing device filled with an absorbent is connected to these fuel tanks and the like. This absorbent is for capturing evaporated fuel. And, as the absorbent used in the evaporated fuel processing device, conventionally, mainly activated carbon has been used.

However, in the evaporative fuel processing apparatus using the activated carbon, the evaporative fuel cannot be often captured,
It occurs that vaporized fuel is released to the atmosphere. One of the main causes of this is a decrease in the vapor trapping capacity (working capacity) due to contact between activated carbon and liquid fuel. this is,
This occurs when the vaporized fuel is liquefied and vaporized on the inner wall surface of the pipe connected to the fuel vapor treatment apparatus and the space where the activated carbon does not exist in the fuel vapor treatment apparatus, and reaches the activated carbon along the inner wall surface.

Another cause is a decrease in working capacity due to adsorption of high boiling point components in fuel onto activated carbon. Among the fuel components adsorbed on the activated carbon, the low boiling point components having 4 or 5 carbon atoms or less are easily released during purging, while the high boiling point components larger than this are difficult to be released. .

Further, in order to deal with the above problem, Japanese Patent Laid-Open No.
It has been proposed to use a polymer absorbent together with activated carbon as an absorbent, as in Japanese Patent No. 227861 and US Pat. No. 4,684,382. In these, the absorbent chamber of a conventionally known evaporative fuel processing apparatus is divided into two chambers by a partition plate having a large number of pores, one chamber is filled with activated carbon, and the other chamber is filled with a polymeric absorbent. It is configured to be filled with.

The high boiling point component in the fuel vapor and the liquefied fuel are absorbed by the polymer absorbent to secure the working capacity of the activated carbon. However, in the above conventional technique (Japanese Patent Laid-Open No. 1-227861), the polymer absorbent and the activated carbon are adjacent to each other by a large number of through holes, and the evaporated fuel absorbed by the polymer absorbent evaporates over time, It is transferred and adsorbed to the adjacent activated carbon. Therefore, the adsorption capacity of activated carbon is reduced. Further, in the above-mentioned US Pat. No. 4,684,382, the vaporized fuel absorbed by the EPDM elastomer foam is vaporized, transferred to and adsorbed to the adjacent activated carbon, and the adsorption capacity of the activated carbon is reduced.

Therefore, as shown in FIGS. 5 to 7, the inventors provided a liquid reservoir at the bottom of the activated carbon chamber 11 and arranged the bottom of the absorbent case 2 filled with the polymer absorbent therein. An evaporative fuel processor was prototyped. That is, as shown in FIG. 5, this evaporative fuel treatment system includes an absorbent case 2 filled with a polymeric absorbent 3 and an activated carbon chamber 1 filled with activated carbon 4.
1, and both are connected by a skirt portion 21 provided on the outer periphery of the lower part of the activated carbon chamber 11.

As shown in FIGS. 5 to 7, the skirt portion 21 has a vapor transfer passage 210 which connects the lower portion of the absorbent case 2 and the activated carbon chamber 11 to each other. Also, the skirt part 2
As shown in FIG. 8 which will be described later, No. 1 has a lower end portion 215 that is open at the bottom and is in close contact with the bottom surface 13 of the activated carbon chamber 11. The vapor transfer passage 210 of the skirt portion 21 is formed in two directions in a semi-annular shape by the semi-annular walls 211 and 212 (FIGS. 6 and 7).

The absorbent case 2 is shown in FIGS.
As shown in FIG. 5, a contact bottom plate 25 that contacts the liquid storage bottom surface 140 of the liquid storage portion 14 of the activated carbon chamber 11 is provided inside the skirt portion 21. The contact bottom plate 25 has a central hole 26 and a plurality of peripheral holes 27 provided around the central hole 26, as shown in FIG. And the central hole 26 and the peripheral hole 27
A ring-shaped connecting portion 251 is provided between and.

Also, the annular connecting portion 251 and the peripheral hole 2
A rib 252 that divides the peripheral hole 27 into four is provided between the outer peripheral edge 253 and the outer peripheral edge 253. The contact bottom plate 25 has a downwardly concave shape, and a suction member 28 for sucking up the liquid fuel accumulated in the liquid reservoir 14 is disposed therein (FIG. 5).

On the other hand, the activated carbon chamber 11 has, as shown in FIGS. 5 and 7, a concave liquid reservoir 14 which is lower than the bottom 13 at the bottom thereof. The liquid reservoir portion 14 has a liquid reservoir bottom surface 140 with which the contact bottom plate 25 of the absorbent case 2 abuts. The activated carbon chamber 11 is filled with activated carbon between the perforated plates 190 and 193.

Next, when the evaporated fuel is absorbed and captured in the evaporated fuel processing apparatus, the evaporated fuel 80 (solid arrow) evaporated from the fuel tank 82 is supplied to the valve 15
1, through the introduction pipe 15, enters the absorbent case 2, and is absorbed by the polymer absorbent 3. Further, the evaporated fuel 80 that has not been absorbed here is from below the absorbent case 2 as shown in FIG.
Through the lower space chamber 145 below the activated carbon chamber 11.

Then, the vaporized fuel 80 passes through the perforated plate 190 and rises, and is absorbed by the activated carbon 4 in the activated carbon chamber 11. On the other hand, when desorbing (purging) the absorbed evaporated fuel, the air 60 (dotted line arrow) is introduced from the atmospheric pipe 17 by the negative pressure in the engine intake passage 85.
The air 60 enters the absorbent case 2 through the activated carbon chamber 11, the lower space chamber 145, and the vapor transfer passage 210 in the skirt portion 21 of the absorbent case 2. In addition, the air 6
0 enters the engine intake passage 85 through the purge pipe 16 and the valve 161.

The air 60 desorbs the vaporized fuel absorbed by the activated carbon 4 and the polymer absorbent 3 during the circulation, and sends the vaporized fuel into the engine through the engine intake passage 85. In addition, the liquid reservoir 14 of the activated carbon chamber 11
At, the liquid fuel condensed and liquefied in the activated carbon chamber flows down and accumulates. The liquid fuel is quickly sucked up by the suction material and is absorbed and captured by the polymer absorbent 3.

In the absorbent case 2, the first important thing is that the lower end portion 215 of the skirt portion 21 is
Is that it is in close contact with the bottom surface 13 of the activated carbon chamber 11. This close state is not formed (FIG. 8 described later)
And from the bottom of the absorbent case 2 to the lower chamber 1 of the activated carbon chamber 11.
The evaporated fuel 80 leaks directly to 45.

That is, since the skirt portion forms a vapor passage, if vaporized fuel directly leaks, the function of the vapor passage is to reduce the diffusion area and lengthen the diffusion distance to reduce the diffusion speed. It will be damaged. Then, the fuel vapor easily migrates from the absorbent case to the activated carbon chamber, and the working capacity of activated carbon decreases. Secondly, in the absorbent case 2, the second important point is that the contact bottom plate 25 of the absorbent case 2 surely contacts the liquid reservoir bottom surface 140 of the liquid reservoir portion 14.

If this contact is not sufficient (FIG. 7, which will be described later), the liquid fuel accumulated between the contact bottom plate 25 and the bottom surface 140 of the liquid is promptly absorbed into the polymer absorbent 3 by the suction material 28. Liquid fuel remains without being pumped in the direction. Therefore, when the vehicle suddenly starts or stops, liquid fuel moves to the activated carbon chamber, which causes deterioration of the activated carbon. As is known from the above, it is necessary that the lower end portion 215 of the skirt portion 21 and the bottom surface 13 of the activated carbon chamber 11 and the contact bottom plate 25 and the liquid storage bottom surface 140 are arranged in contact with each other. .

[0018]

However, the above vaporized fuel processing device has the following problems. That is, the absorbent case 2 and the activated carbon chamber 11 have variations in size due to their manufacture. Therefore, in both of the above contact portions, one of them may be in a close contact state, but the other may not be in a close contact state.

In FIG. 7, the lower end portion 215 of the skirt portion 21 and the bottom surface 13 of the activated carbon chamber 11 are in close contact with each other, but a gap G1 is formed between the contact bottom plate 25 and the liquid bottom surface 140. Is shown. On the other hand, FIG. 8 shows the contact bottom plate 2
5 and the liquid storage bottom surface 140 are in close contact with each other, but a gap G2 is formed between the lower end portion 215 of the skirt portion 21 and the bottom surface 13 of the activated carbon chamber 11.

In view of the above-mentioned conventional problems, the present invention can form an intimate state of the above two places in the absorbent case and the activated carbon chamber, and does not reduce the working capacity of the activated carbon, and is excellent in trapping evaporated fuel. It is an object of the present invention to provide a vaporized fuel processing device having the capability.

[0021]

The present invention has an absorbent case filled with a polymeric absorbent, and an activated carbon chamber in which the absorbent case is inserted and arranged and which is filled with activated carbon. The absorbent case is in communication with each other so that the evaporated fuel can be transferred, and the fuel storage device and the engine intake passage are communicated with the absorbent case by an evaporated fuel introduction pipe and a purge pipe, respectively, to the activated carbon chamber. Is an evaporative fuel processing apparatus equipped with an atmosphere opening means,
The activated carbon chamber has a concave liquid reservoir at a bottom portion thereof which is lower than the bottom surface. On the other hand, the absorbent case is located below the outer periphery of the main body, and the vapor transfer along the outer peripheral shape and communicates with the activated carbon chamber. The skirt has a skirt that forms a passage, the skirt has an open bottom and a lower end that contacts the bottom surface of the activated carbon chamber. Also has a contact bottom plate at the inner lower part that comes into contact with the bottom surface of the liquid in the liquid reservoir of the activated carbon chamber. In the evaporated fuel processing device, a plurality of slits are provided in the section.

What is most noticeable in the present invention is that a skirt portion forming the vapor transfer passage and the contact bottom plate are provided in the lower portion of the absorbent case, and the central hole and the peripheral hole are provided in the contact bottom plate, and A slit is provided in the annular connecting portion of the contact bottom plate.

The slit of the annular connecting portion cuts the annular connecting portion and has a gap of 1 to 3 mm.
The annular connecting portion is located between the central hole and the peripheral hole, and has a plurality of peripheral holes. In addition, a plurality of ribs connecting the annular connecting portion and the outer peripheral edge are provided between the peripheral holes. The slits are formed at a plurality of places in the annular connecting portion (see FIG. 3).

The contact bottom plate has a concave shape so as to enter the liquid reservoir of the activated carbon chamber. Further, it is preferable that the contact bottom plate has some elasticity. As a result, when the absorbent case is assembled to the activated carbon chamber, the ribs are easily deformed, and the close contact state is more effectively formed.

The steam transfer passage provided in the skirt is
This is a passage for passing the fuel vapor but not the liquid fuel in the evaporated fuel introduced into the absorbent case by the introduction pipe. Further, since the vapor transfer passage is provided around the absorbent case, the distance becomes long. Therefore,
Fuel vapor is also retained during this time, and evaporative fuel rarely reaches the activated carbon chamber.

[0026]

In the present invention, the evaporated fuel introduced by the introduction pipe is first absorbed by the polymer absorbent. Then, only the vaporized fuel not absorbed by the polymer absorbent enters the activated carbon chamber through the vapor transfer passage of the skirt and is adsorbed by the activated carbon. On the other hand, at the time of purging, the atmospheric air sequentially passes through the activated carbon chamber, the vapor transfer passage, and the absorbent case to separate the evaporated fuel absorbed by the activated carbon and the polymer absorbent, and at the same time, to purge with the evaporated fuel. It is led out to the engine intake side through a pipe.

Next, what is important in the present invention is that the space between the lower end of the skirt of the absorbent case and the bottom of the activated carbon chamber, and between the contact bottom plate of the absorbent case and the bottom of the liquid reservoir of the activated carbon chamber. , Both are to be formed in close contact.

That is, in the present invention, the plurality of slits are provided in the annular connecting portion of the contact bottom plate. Therefore, when the absorbent case is inserted into the activated carbon chamber and the contact bottom plate of the absorbent case is positioned in the liquid reservoir of the activated carbon chamber, the annular connecting portion first contacts the liquid reservoir bottom surface of the liquid reservoir,
The ribs then elastically deform due to the slits.
Therefore, the lower end of the skirt portion can be arranged in close contact with the bottom surface of the activated carbon chamber.

Therefore, both the contact bottom plate and the bottom surface of the liquid reservoir, and both the lower end of the skirt portion and the bottom surface of the activated carbon chamber can be brought into close contact with each other. Therefore, an efficient effect of the vapor transfer passage, which will be described later, can be exerted, and the absorption and absorption of the liquid fuel accumulated in the liquid reservoir into the polymer absorbent can be promoted.

Further, in the present invention, the vapor transfer passage is provided in the skirt portion of the absorbent case. As a result, the migration distance of the fuel vapor between the absorbent case and the activated carbon chamber becomes long, and the evaporated fuel absorbed by the polymer absorbent does not easily migrate to the activated carbon chamber.

The mechanism by which the fuel trapped in the polymer absorbent transfers to the activated carbon is considered as follows. That is, the fuel evaporates from the polymer absorbent and the fuel vapor concentration in the absorbent case increases. On the other hand, the fuel vapor concentration in the activated carbon chamber is low. Due to this concentration gradient of the fuel vapor, the fuel vapor diffuses into the activated carbon chamber and is adsorbed by the activated carbon.

Generally, the diffusion rate is proportional to the diffusion area and inversely proportional to the diffusion distance. In the present invention, since the vapor transfer passage is provided between the absorbent case and the activated carbon chamber, the diffusion area can be reduced and the diffusion distance can be increased. Therefore, the diffusion rate of the fuel vapor can be reduced in the vapor transfer passage, and the transition of the fuel vapor from the absorbent case to the activated carbon chamber can be suppressed as much as possible. Therefore, it is possible to suppress a decrease in working capacity of activated carbon.

Further, since the vapor trapping ability of the activated carbon can be utilized close to 100%, it is not necessary to unnecessarily increase the amount of the activated carbon and the evaporative fuel processing apparatus can be downsized. As described above, according to the present invention, the above two locations in the absorbent case and the activated carbon chamber can be formed in close contact with each other, and the working capacity of the activated carbon is not reduced.
It is possible to provide an evaporated fuel processing device having an excellent evaporated fuel capturing ability.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An evaporative fuel processing system according to an embodiment of the present invention will be described with reference to FIGS. The device of this example relates to an evaporated fuel processing device for an automobile. As shown in FIG. 1, the evaporated fuel processing device 1 has an absorbent case 2 filled with a polymer absorbent and an activated carbon chamber 11 filled with activated carbon 4, and the activated carbon chamber 11 and the absorbent case 2 are provided. And are communicated with each other by a steam transfer passage 210.

Further, a fuel tank 8 as a fuel storage device
2 and the engine intake passage 85 and the absorbent case 2 are communicated with each other by an evaporated fuel introduction pipe 15 and a purge pipe 16, respectively. In addition, the activated carbon chamber 11
It is open to the atmosphere via a pipe 17.

As shown in FIGS. 1 and 2, the activated carbon chamber 11 has a concave liquid reservoir 14 at a bottom portion thereof which is lower than the bottom surface 13. On the other hand, the absorbent case 2 has a cylindrical body 2
A skirt portion 21 is formed in the lower portion of the outer periphery of 0, which follows the outer peripheral shape and forms a steam transfer passage 210 communicating with the activated carbon chamber 11. The skirt portion 21 has a lower end portion 215 whose lower portion is open and which is in close contact with the bottom surface 13 of the activated carbon chamber 11.

Further, the absorbent case 2 has a liquid reservoir 1 of the activated carbon chamber 11 at a lower inner side of the skirt 21.
4 has a contact bottom plate 25 that contacts the bottom surface 140 of the liquid reservoir. The contact bottom plate 25, as shown in FIG.
6 and four peripheral holes 27 provided around it. Also, an annular connecting portion 251 between the central hole 26 and the peripheral hole 27
Four slits 250 are provided in the.

The steam transfer passage 210 of the skirt portion 21
Is formed in two directions in a semi-circular shape by semi-circular walls 211 and 212 as shown in FIG. Further, each vapor transfer passage 210 has an inlet 217 into which the evaporated fuel leaking from the absorbent case 11 enters, and an outlet 218 from which the evaporated fuel exits to the activated carbon chamber 11 side. The contact bottom plate 25 has four ribs 252 that define the peripheral hole 27 between the outer peripheral edge 253 of the peripheral hole 27 and the annular connecting portion 251.

The contact bottom plate 25 has a downwardly concave shape, in which a suction material 28 for sucking up the liquid fuel is drawn.
Are arranged (Fig. 4). The absorbent case 2 has positioning guide fins 201 on the upper portion of the skirt portion 21 as shown in FIG.

A screen lid 29 is capped on the upper part of the absorbent case 2. In addition, a spring coil 29 for pressing the absorbent case 2 downward is provided between the upper case 103 of the activated carbon chamber 11 and the upper part of the absorbent case 2.
2 is provided. Further, a ring seal 291 is provided between the upper part of the absorbent case 2 and the partition wall 196 described below to seal the two.

Further, in the storage tank 10 constituting the activated carbon chamber 11, there is provided a cylindrical partition wall 196 for partitioning the absorbent storage chamber into which the absorbent case 2 is inserted and the activated carbon chamber. The outer side of the partition wall 196 and the upper and lower porous plates 19 are
Activated carbon 4 is filled between 0 and 193. Others are the same as the above-mentioned conventional example.

Specific examples of the polymer absorbent include polypropylene, polyisoprene, polybutadiene, polyisobutylene, polystyrene, polynorbornene, polydimethylsiloxane, ethylene-propylene-diene copolymer, styrene-butadiene. There are copolymers, ethylene-propylene copolymers, isobutylene-isoprene copolymers, butadiene-acrylonitrile copolymers, and one or more of these are used.

The polymer absorbent may be an uncrosslinked polymer or a crosslinked polymer (polymer gel), and any of them can be used. The former uncrosslinked polymer is of a type that dissolves or swells in fuel, and is generally called a hydrophobic polymer. The homopolymer such as polyisoprene and the copolymer such as styrene-butadiene copolymer are is there.

The latter polymer gel is a cross-link of the above-mentioned hydrophobic polymer, and this cross-link makes the polymer gel insoluble in fuel but swellable. Here, the term "crosslinking" includes not only chemical crosslinking introduced using a crosslinking agent but also chemical self-crosslinking and physical crosslinking.

The shape of the above-mentioned polymer absorbent is not particularly limited as long as it is excellent in absorption and purging property such as powder, particles, film, thread, honeycomb, plate. In addition, in particular, a fiber-shaped absorbent having a polymer gel attached to the fiber (length 10 mm ~
50 mm) has excellent absorption and purging properties. Also,
If a lump that is too large is used, only the surface will swell, and absorption will not proceed as quickly to the inside, and the absorption capacity may decrease. Therefore, the absorbent has a diameter or thickness of 5 m.
It is preferably set to m or less.

The polymer absorbent swelled by absorbing the evaporated fuel is de-swelled in a normal process of purging the inside of the evaporated fuel processing apparatus, its evaporated fuel absorbing capacity is restored, and it is continuously used. can do. Next, as the activated carbon, activated carbon such as steam activated / granular activated carbon which is used in the conventional evaporative fuel processing apparatus is used.

Next, the function and effect will be described. First, the absorption and capture of the vaporized fuel by the polymer absorbent 3 and the activated carbon 4 and their removal (purging) are the same as in the conventional example. What is important in this example is, as shown in FIGS. 1, 2 and 4, between the lower end portion 215 of the skirt portion 21 and the bottom surface 13 of the activated carbon chamber 11 and the absorbent case 2 in the absorbent case 2. Contact bottom plate 25 and activated carbon chamber 11
That is, both of them are formed in close contact with each other.

That is, in this example, as shown in FIGS. 2 and 4, the absorbent case 2 is inserted into the absorbent storage chamber in the storage tank 10, and the contact bottom plate 25 is attached to the liquid reservoir 14 of the activated carbon chamber 11. When it is positioned at
The liquid 1 contacts the bottom surface 140 of the liquid reservoir 14.

When the absorbent case 2 is further lowered, the rib 252 is elastically deformed due to the slit 250 provided in the annular connecting portion 251. Therefore, the lower end portion 215 of the skirt portion 21 provided on the outer periphery of the lower portion of the absorbent case 2 also comes into close contact with the bottom surface 13 of the activated carbon chamber 11.

FIG. 4 illustrates the above-mentioned effects.
In the free state, the contact bottom plate 25 is in a state of extending downward as shown by the dotted line in the figure (the figure is exaggerated for the sake of explanation). Therefore, as described above, the absorbent case 2 is inserted, and the contact bottom plate 25 becomes the bottom surface 1 of the liquid reservoir.
When the absorbent case 2 is further lowered, the ribs 252 of the contact bottom plate 25 are deformed as shown by the solid line. Therefore, as described above, the lower end portion 215 of the skirt portion can also come into close contact with the bottom surface 13.

As described above, the contact bottom plate 25 and the bottom surface 14 of the liquid reservoir are
0, and both of the lower end portion 215 of the skirt portion and the bottom surface 13 of the activated carbon chamber can be brought into close contact with each other. Therefore, the steam transfer passage 210 of the skirt portion 21
Is a bottom surface 13 of the activated carbon chamber 11 as shown in FIGS.
Can form a semi-annular passage having a closed bottom surface.

Therefore, the evaporated fuel can be retained in this passage as well, and the evaporated fuel can be prevented from flowing out to the activated carbon chamber 11. Therefore, as described above, the working capacity of activated carbon is not reduced. Further, since the contact bottom plate 25 of the absorbent case is in contact with the liquid reservoir bottom surface 140, the liquid fuel accumulated in the liquid reservoir portion 14 is easily sucked from the central hole 26 and the peripheral holes 27 through the suction material 28. It is fried and can be absorbed and captured by the polymer absorbent 3.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an evaporated fuel processing device according to an embodiment.

FIG. 2 is a sectional view of a main part of an absorbent case according to an embodiment.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is an operation explanatory view of the contact bottom plate of the absorbent case in the embodiment.

FIG. 5 is a cross-sectional view of an evaporated fuel processing device in a conventional example.

6 is a sectional view taken along the line BB of FIG.

FIG. 7 is an explanatory view showing a problem of the absorbent case in the conventional example.

FIG. 8 is an explanatory view showing another problem of the absorbent case in the conventional example.

[Explanation of symbols]

 1. ． ． Evaporative fuel treatment device, 10. ． ． Storage tank, 11. ． ． Activated carbon chamber, 13. ． ． Bottom surface, 14. ． ． Liquid reservoir, 140. ． ． Bottom of liquid reservoir, 15. ． ． Introduction pipe, 16. ． ． Purge pipe, 17. ． ． Atmospheric pipe, 2. ． ． Absorbent case, 21. ． ． Skirt part, 210. ． ． Steam transfer passage, 25. ． ． Contact bottom plate, 250. ． ． Slit, 251. ． ． Annular connecting portion, 252. ． ． Rib, 26. ． ． Central hole, 27. ． ． Surrounding holes, 3. ． ． Polymer absorbent, 4. ． ． Activated carbon,

Claims (1)

[Claims] 1. An absorbent case filled with a polymeric absorbent, and an activated carbon chamber in which the absorbent case is inserted and arranged and activated carbon is filled. The activated carbon chamber and the absorbent case are provided. The vaporized fuel is communicated with each other so that the vaporized fuel can be transferred, and the fuel storage device, the engine intake passage, and the absorbent case are communicated with each other by a vaporized fuel introduction pipe and a purge pipe, respectively, and the activated carbon chamber is provided with an atmosphere release means. In the evaporative fuel processing device provided, the activated carbon chamber has a concave liquid reservoir at a bottom portion thereof which is lower than a bottom surface thereof, while the absorbent case is provided at a lower peripheral portion of a main body with an outer peripheral shape thereof. Along with the skirt portion forming a vapor transfer passage communicating with the activated carbon chamber, the skirt portion having a lower end opening and a lower end portion contacting the bottom surface of the activated carbon chamber, Also, the absorbent case
A contact bottom plate that contacts the bottom surface of the liquid in the liquid storage portion of the activated carbon chamber is provided below the skirt portion, and the contact bottom plate has a central hole and a plurality of peripheral holes provided around the central hole. An evaporated fuel processing device, characterized in that a plurality of slits are provided in an annular connecting portion between them.