JPH051644Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a canister for adsorbing evaporated fuel mounted on a vehicle.

(Prior art) As a type of evaporative fuel adsorption canister mounted on a vehicle, for example, Japanese Utility Model Application Publication No. 59-142459 discloses a case in which partition walls protruding into the adsorbent chamber are erected on the top and bottom surfaces of the case. This partition wall allows the evaporated fuel to pass between both sides of the case from the evaporated fuel inlet at the top of the case to the atmosphere port at the bottom of the case, creating a curved path that travels in a direction perpendicular to the reciprocating direction. A canister for adsorbing evaporated fuel is disclosed.

(Problems to be Solved by the Invention) According to the above-mentioned conventional canister, the evaporated fuel passage from the evaporated fuel inlet to the atmosphere port is a curved path, so that the passage length becomes long.

However, when the evaporated fuel flowing in from the evaporative fuel inlet advances through the adsorbent layer along the curving path formed by the partition wall, the evaporative fuel flows through the curving path so that the ventilation resistance received from the adsorbent is minimized. Since the shortest route is taken, the entire area of the adsorbent layer is not necessarily utilized effectively, and in particular, the adsorbent layer on the upper and lower surfaces of the case, the side surfaces of the case, or the corners surrounded by the partition wall is hardly utilized.

In view of these problems, it is an object of the present invention to provide a canister for adsorbing evaporated fuel that can effectively utilize the entire area of the adsorbent layer.

In order to achieve the above object, the canister for adsorbing evaporated fuel in the present invention has a pair of upper and lower partitions 12, 13 made of a porous retaining plate and a filter disposed laterally inside a case 11 to define an adsorbent chamber filled with an adsorbent between the two partitions, an upper diffusion chamber 16 is formed between the upper partition and the top surface of the case, and a lower diffusion chamber 17 is formed between the lower partition and the bottom surface of the case. A partition wall 11c is disposed vertically from the top surface of the case to divide the upper diffusion chamber into two left and right chambers, a first diffusion chamber 16a and a second diffusion chamber 16b, and the adsorbent chamber is divided into a first adsorbent chamber 16b and a second diffusion chamber 16c.
The first diffusion chamber is provided with an air vent 18, and the second diffusion chamber is provided with an evaporated fuel inlet 19 and an evaporated fuel outlet 20. Furthermore, the lower partition 13 is a single piece that is common to the two left and right adsorbent chambers, and the lower edge of the partition wall 11c is positioned away from the lower partition 13 so that a small gap is formed between it and the lower partition 13.

(Function) According to the above configuration, the evaporated fuel that has flowed into the second diffusion chamber from the evaporated fuel inlet is diffused here, and then flows into the second adsorbent chamber through the upper partition wall, and a portion of the evaporated fuel flows into the second diffusion chamber.
The remaining vaporized fuel is adsorbed and collected by the adsorbent filled in the adsorbent chamber, and the remaining evaporated fuel flows into the lower diffusion chamber through the lower partition wall. After the remaining evaporated fuel is diffused again here, it flows into the first adsorbent chamber through the lower partition wall and is adsorbed and collected by the adsorbent filled therein.

On the other hand, when negative intake pressure acts on the evaporated fuel outlet, fresh air flows into the first diffusion chamber from the atmosphere port, and this fresh air is sequentially introduced into the first adsorbent chamber, the lower diffusion chamber, the second adsorbent chamber, and the second adsorbent chamber.
The vaporized fuel flows out through the second diffusion chamber and out the vaporized fuel outlet.
When the fresh air passes through the first adsorbent chamber and the second adsorbent chamber, the evaporated fuel adsorbed by the adsorbent is separated, and the evaporated fuel flows out from the evaporated fuel outlet together with the separated evaporated fuel.

However, according to the present invention, since the adsorbent chamber is divided into two chambers on the left and right, the first adsorbent chamber and the second adsorbent chamber, the evaporated fuel passage becomes longer and the upper part of both adsorbent chambers is separated. Since a first diffusion chamber and a second diffusion chamber are formed, and a lower diffusion chamber is formed at the bottom, the evaporated fuel that flows in from the evaporated fuel inlet and the fresh air that flows in from the atmosphere port are diffused in each diffusion chamber, and then the adsorption Flows into the drug chamber. Therefore, adsorption and desorption effects are performed over the entire area of the adsorbent layer, so that the adsorption and desorption performance of the canister is improved.

When filling the adsorbent, before attaching the lower partition wall, turn the case upside down and fill the adsorbent from the lower end of both adsorbent chambers. It is necessary to install the lower partition wall after equalizing the height of the partition wall, but the lower edge of the partition wall is positioned at a distance from the lower partition wall so that a slight gap is formed between the partition wall and the lower partition wall. Therefore, when filling the adsorbent, the adsorbent goes over the lower edge of the partition wall and is filled flush across both chambers, making leveling work easy and ensuring that both finished surfaces are made even.

(Example) An example of the present invention will be described below based on the drawings.

In Fig. 1, a canister 1 for adsorbing evaporated fuel
0 has a case 11 consisting of a case body 11a with an open bottom and a bottom cover 11b attached to the bottom to cover the opening, and inside the case body 11a, a pair of upper and lower partition walls 12 and 13 are provided between both sides. It is installed horizontally. The partition walls 12 and 13 form an adsorbent chamber 15 in which the adsorbent 14 is filled between the partition walls 12 and 13, and an upper diffusion chamber 16 is formed between the upper partition wall 12 and the upper surface of the case body 11a. Furthermore, a lower diffusion chamber 17 is formed between the lower partition wall 13 and the bottom cover 11b.

Both partition walls 12 and 13 include porous retaining plates 12a and 13a each having a large number of through holes, and a filter 12.
The upper diffusion chamber 16 and the adsorbent chamber 15 communicate with each other via the upper partition wall 12, and the lower diffusion chamber 17 and the adsorbent chamber 15 communicate with each other via the lower partition wall 13. Further, the upper diffusion chamber 16 and the adsorbent chamber 15 are connected to a partition wall 1 that is vertically disposed from the upper surface of the case body 11a.
1c into two chambers on the left and right: a first diffusion chamber 16a and a second diffusion chamber 16b, and a first adsorbent chamber 15a and a second adsorbent chamber 15b. This partition wall 1 is located between the first diffusion chamber 16a and the second diffusion chamber 16b.
1c, the first diffusion chamber 16a is provided with an atmosphere port 18, and the second diffusion chamber 16b is provided with an evaporated fuel inlet 19 and an evaporated fuel outlet 20. Further, a gap of a predetermined width X is formed between the lower end of the partition wall 11c and the lower partition wall 13.

The present embodiment has the above-described configuration, and the evaporated fuel inlet 19 is connected to the fuel tank of the vehicle or the float chamber of the carburetor, and the evaporated fuel outlet 20 is connected to the intake manifold. The evaporated fuel generated in the fuel tank or float chamber while the engine is stopped flows into the second diffusion chamber 16b from the evaporated fuel inlet 19 and is diffused there, then passes through the upper partition wall 12 to the second adsorbent chamber 1
5b, a part of which is adsorbed and collected by the adsorbent 14 filled in the second adsorbent chamber 15b, and the remaining vaporized fuel passes through the lower partition wall 13 and flows into the lower diffusion chamber 17.
flows into. The remaining evaporated fuel is diffused again here and then passes through the lower partition wall 13 to the first adsorbent chamber 15.
a, and is adsorbed and collected by the adsorbent filled therein.

On the other hand, when the intake negative pressure generated in the intake manifold due to engine drive acts on the evaporated fuel outlet 20, fresh air flows into the first diffusion chamber 16a from the atmosphere port 18, and this fresh air is sequentially introduced into the first adsorbent chamber 15a, Lower diffusion chamber 17, second adsorbent chamber 15b, second diffusion chamber 1
The vaporized fuel exits from the vaporized fuel outlet 20 through 6b. Then, when the fresh air passes through the first adsorbent chamber 15a and the second adsorbent chamber 15b, the evaporated fuel adsorbed by the adsorbent 14 is separated, and together with the separated evaporated fuel, it flows out from the evaporated fuel outlet 20 and the intake air is Flows into the manifold.

As explained above, according to this embodiment, the adsorbent chamber 15 is divided into the first adsorbent chamber 15a and the second adsorbent chamber 15a.
Since it is divided into two chambers, left and right, the evaporated fuel passage becomes longer, and the area in which the adsorbent layer can be used becomes wider.

In addition, a first diffusion chamber 16a and a second diffusion chamber 16b are formed in the upper part of both adsorbent chambers 15a and 15b, respectively, and a lower diffusion chamber 17 is formed in the lower part, so that the evaporated fuel flowing in from the evaporated fuel inlet 19 and the atmosphere Fresh air flowing in from the mouth is diffused in each diffusion chamber and then flows into each adsorbent chamber. Therefore, the adsorption action and desorption action take place throughout the entire area of the adsorbent layer, thereby greatly improving the performance of the canister.

By the way, in order to fill the adsorbent chamber 15 with the adsorbent 14, before attaching the bottom cover 11b and the lower partition wall 13, turn the case main body 11a upside down and insert the adsorbent 14 from the lower end side of the adsorbent chamber 15. After that, the lower partition wall 13 is attached and the adsorbent 14 is attached to the lower partition wall 1.
3, the adsorbent chamber 15 is held under pressure.
If the heights of the adsorbent layer 14 in the adsorbent chamber 15a and adsorbent chamber 15b are different, the adsorbent 14 cannot be pressed uniformly when the lower partition wall 13 is attached, and the lower partition wall 13
The porous holding plate 13a constituting the structure becomes easily deformable.
However, in this embodiment, since a predetermined width X is formed between the lower end of the partition wall 11c and the lower partition wall 13,
When filling the adsorbent 14, the partition wall 11c is buried in the adsorbent layer. Therefore, both finished surfaces are partition wall 1
Since it is continuous without being interrupted by 1c, it becomes easy to level both finished surfaces evenly.

Note that if the predetermined width X is too wide, a considerable amount of evaporated fuel and fresh air will not pass through the lower diffusion chamber 17 but will flow into the adjacent adsorbent chambers 15a and 15b through this gap, which will reduce the diffusion effect of the lower diffusion chamber 17. In particular, the adsorbent layer at the lower left corner of the first adsorbent chamber 15a is not utilized, and the adsorption/desorption performance (working capacity) is reduced.

FIG. 2 shows a characteristic curve showing the relationship between the working capacity and the predetermined width X obtained through experiments.
According to this experiment, the working capacity shows a high value when the predetermined width X is 5 mm or less;
Above that, it drops rapidly. Therefore, it is preferable to set the predetermined width X to 5 mm or less.

(Effect of the invention) According to the invention, the adsorbent chamber is divided into two chambers on the left and right, the first adsorbent chamber and the second adsorbent chamber, and the evaporated fuel passage is lengthened, and the upper part of both adsorbent chambers is Since a first diffusion chamber and a second diffusion chamber are formed, and a lower diffusion chamber is formed at the bottom, the evaporated fuel that flows in from the evaporated fuel inlet and the fresh air that flows in from the atmosphere port are diffused in each diffusion chamber, and then the adsorption Flows into the drug chamber. Therefore, since the adsorption and desorption effects are performed over the entire area of the adsorbent layer, it is possible to improve the adsorption and desorption performance of the canister.

In addition, there is a specified width between the lower end of the partition wall and the lower partition wall.
When filling the adsorbent with the case turned upside down, the filled surface of the adsorbent crosses the lower edge of the partition wall and becomes flush across both chambers, making the leveling process easier in one step. A uniform finished surface can be obtained in both chambers.
Since the upper and lower partition walls are made of a single piece that is common to both chambers, there is a practical advantage that the installation work to the case can be done at the same time as both chambers.

[Brief description of the drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention, and Fig. 2 is a characteristic curve showing the relationship between the width X of the gap formed between the lower end of the partition wall and the lower partition wall and the working capacity in this embodiment. It is a diagram. 10... Canister for vaporized fuel adsorption, 11...
Case, 11c...Partition wall, 12, 13...Partition wall, 14...Adsorbent, 15...Adsorbent chamber, 16...
...Upper diffusion chamber, 17...Lower diffusion chamber, 18...Atmospheric port, 19...Evaporative fuel inlet, 20...Evaporative fuel outlet.

Claims (1)

[Claims for Utility Model Registration] A pair of upper and lower partition walls 12 and 13 consisting of a porous holding plate and a filter installed horizontally inside the case 11 form an adsorbent chamber filled with an adsorbent between the two partition walls. Upper diffusion chamber 16 between the upper surfaces of the case
A lower diffusion chamber 1 is formed between the lower partition wall and the bottom of the case.
The upper diffusion chamber is divided into two chambers on the left and right, a first diffusion chamber 16a and a second diffusion chamber 16b, by a partition wall 11c formed as 7 and vertically disposed from the upper surface of the case, and the adsorbent chamber is divided into a first adsorbent chamber 15a and a second diffusion chamber 16b. Second adsorbent chamber 1
5b, and the first diffusion chamber has an air port 1.
8, and the second diffusion chamber is provided with an evaporated fuel inlet 19 and an evaporated fuel outlet 20, and the lower partition wall 13 is a single piece common to the two left and right adsorbent chambers, and the lower edge of the partition wall is A canister for adsorbing evaporated fuel, characterized in that it is positioned apart from the lower partition wall so that a slight gap is formed between the canister and the lower partition wall.