JPH02102358A - Canister for fuel evaporated absorption - Google Patents

Abstract

PURPOSE:To prevent the impalpable powder of absorbents from leaking into a dispersion chambers by pinching the end section of opening of a cylindrical grid which is inserted into a cylindrical case hermetically between the end section of the cylindrical case and the end section of a cover. CONSTITUTION:An evaporated fuel absorbing canister 10 is equipped with a cylindrical case 11 the right and left ends of which are opened, a pair of cylindrical grids 14 and 15 which is inserted into the cylindrical case 11 so that an absorbent chamber 13 is formed so as to be partitioned, and with covers 16 and 17 which are set in the right and left end sections of the opening of the cylindrical case 11. In both of the cylindrical grids 14 and 15, filters 18 and 19 are adhered onto each of bottom surfaces wherein a number of through holes 14a and 15a are perforated, and absorbents 12 are filled in between both of the filters 18 and 19 so that a absorbent layer is thereby formed. In this case, turn-down sections 14b and 15b are formed at the end sections of the openings of the cylindrical grids 14 and 15, hermetical connection is made in such a way each turn-down section 14b and 15b is rolled in between the end section of the opening of the cylindrical case 11 and the end section of each cover 16 and 17. This constitution thereby prevents the impalpable powder of the absorbents 12 from leaking into dispersion chambers 20 and 21.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an evaporated fuel adsorption canister mounted on a vehicle.

(Prior Art) As a type of evaporated fuel adsorption canister mounted on a vehicle, for example, Japanese Utility Model Application Publication No. 58-186828 discloses a cylindrical case with both ends open and a number of holes formed in the bottom surface. a pair of cylindrical grids each having one end open and fitted inside the cylindrical case; a filter affixed to the bottom surface of both grids; and a pair of cylindrical grids respectively attached to both open ends of the cylindrical case. an adsorbent layer is formed by filling an adsorbent between the two filters, an air vent is provided in the - side cover, and a diffusion chamber is defined between the cover and the one grid. discloses a canister for adsorbing evaporated fuel in which the other cover is provided with an evaporated fuel inlet and an evaporated fuel outlet, and a diffusion chamber is defined between the cover and the other grid.

(Problem to be Solved by the Invention) The filter is generally shaped like a cylindrical piece with a certain tightening margin so that no gap is formed between the end of the filter and the inner peripheral surface of the cylindrical case when attached to the bottom of the grid. It is manufactured in a shape that is slightly larger than the cross-sectional shape of the case.

However, if the cylindrical case has an irregular cross-sectional shape, it is difficult to obtain a uniform tightening margin over the entire circumference of the cylindrical case. A gap may be partially formed between the end of the filter and the end of the filter. When a gap is created between the end of the filter and the inner peripheral surface of the cylindrical case, fine powder of the adsorbent passes through this gap and enters between the cylindrical case and the cylindrical grid from the adsorbent chamber.

However, in the above-mentioned conventional canister, the cylindrical grid is loosely inserted into the cylindrical case, and its open end merely contacts the inner surface of the cover, and is not fixed to either the cylindrical case or the cover. . Therefore, when the thickness of the adsorbent layer is compressed by the vibration of the vehicle, the cylindrical grid moves and the open end of the cylindrical grid separates from the cover, removing the adsorbent fine particles that have entered between the cylindrical case and the cylindrical grid. There was a possibility that it would leak into the diffusion room.

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide a canister for adsorbing evaporated fuel that can prevent fine adsorbent powder from leaking into a diffusion chamber.

(Means for Solving the Problems) The present invention, which meets the above objects, includes a cylindrical case with both ends open, a number of through holes formed in the bottom surface, one end open, and a cylindrical case that is inserted into the inside of the cylindrical case. a pair of cylindrical grids, filters attached to the bottoms of both grids, and a pair of covers attached to both open ends of the cylindrical case, and an adsorbent is filled between the filters. to form an adsorbent layer, an air inlet is provided in the one cover, a diffusion chamber is defined between the cover and the one grid, and an evaporative fuel inlet and an evaporative fuel outlet are provided in the other cover, and In a canister for adsorbing evaporated fuel in which a diffusion chamber is defined between the cover and the other grid,
The gist is that the open end of the cylindrical grid is airtightly sandwiched between the open end of the cylindrical case and the end of the cover.

(Function) According to the above configuration, even if fine powder of the adsorbent enters between the cylindrical case and the cylindrical grid through the gap formed between the inner peripheral surface of the cylindrical case and the end of the filter, Since the open end of the shaped grid is airtightly sandwiched between the open end of the cylindrical case and the end of the cover, it is possible to prevent fine adsorbent powder from leaking into the diffusion chamber.

(Example) A first embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, a canister 10 for adsorbing evaporated fuel has a cylindrical case 11 with both left and right ends open, and an interior of the cylindrical case 11 that defines an adsorbent chamber 13 filled with an adsorbent 12 made of activated carbon powder. A pair of cylindrical grids 14, 1.5 fitted into the cylindrical case 11, a cover 16 attached to the left opening end of the cylindrical case 11, and a cover 17 attached to the right frontage end of the cylindrical case 11. There is.

Both cylindrical grids 14, 15 are open at one end and have a large number of through holes 14a, 15g in their bottom surfaces, respectively. Further, filters 18 and 19 are attached to each bottom surface, and an adsorbent 12 is filled between the filters 18 and 19 to form an adsorbent layer.

A diffusion chamber 20 is defined between the cover 16 and the cylindrical grid 14, and the cover 16 is provided with an air port 21 communicating with the diffusion chamber 20.

A diffusion chamber 22 is defined between the cover 17 and the cylindrical grid 15, and the cover 17 is provided with an evaporative fuel inlet 23 and an evaporative fuel outlet 24 communicating with the diffusion chamber 22. The adsorbent chamber 13 and each diffusion chamber 20.22 have through holes 14.
a, 15a and filter 18.1.
9 allows the adsorbent 12 to pass from the adsorbent chamber 13 to the through holes 14a, 1.
5a to the diffusion chamber 20.22.

Next, a bent part 14b is formed at the open end of the cylindrical grid 14, and the bent part 14b is sandwiched between the left open end of the cylindrical case 11 and the end of the cover 16. and each end is crimped so that the joint is airtight. Similarly, a bent portion 151+ is formed at the open end of the cylindrical grid 15, and the new bent portion 15b is formed at the open end of the cylindrical grid 15.
The cover 17 is airtightly sandwiched between the right open end of the cover 1 and the end of the cover 17.

The first embodiment has the above-described configuration, with the evaporated fuel inlet 23 connected to the fuel tank of the vehicle or the float chamber of the carburetor, and the evaporated fuel outlet 24 connected to the intake manifold. The evaporated fuel generated in the fuel tank or float chamber while the engine is stopped flows from the evaporated fuel population 23 into the diffusion chamber 22, where it is diffused and then passes through the through hole 15u and the filter 19 to the adsorbent chamber 13. It flows in and is adsorbed and collected by the adsorbent 12.

On the other hand, when the intake negative pressure generated in the intake manifold due to engine drive acts on the evaporated fuel outlet 24, the atmospheric air port 21
Fresh air flows into the diffusion chamber 20 from the vent hole 14a.
The fuel vapor flows into the adsorbent chamber 13 through the first filter 18, further passes through the diffusion chamber 22, and flows out from the evaporated fuel outlet 24. When the fresh air passes through the adsorbent chamber 13, the evaporated fuel adsorbed by the adsorbent 12 is separated, and together with the separated evaporated fuel, it flows out of the evaporated fuel outlet 24 and flows into the intake manifold.

According to the first embodiment, the fine powder of the adsorbent 12 passes through the gap formed between the inner circumferential surface of the cylindrical case 11 and the ends of the filters 18 and 19, and passes between the cylindrical case 11 and the cylindrical grid. 1
4.15 Even if the adsorbent 12 enters the opening, the fine powder of the adsorbent 12 can be prevented from leaking into the diffusion chamber 20, 22 because it is airtightly sandwiched between the ends of the adsorbent 7. Therefore, when manufacturing the filters 18 and 19, there is no need to take a tightening allowance, and the filters 18, 19,
The accuracy of one external dimension can be relaxed. Also, cylindrical case 1
Even if the cross-sectional shape of the filters 18 and 19 is irregular, there is no need to tighten them, so the assembly of the filters 18 and 19 becomes easier.

Next, a second embodiment of the present invention is shown in FIG.

The evaporated fuel adsorption canister 30 shown in FIG. 2 includes a cylindrical case 31 with both ends open, a cylindrical grid 34 with a through hole 34a formed in the bottom surface, and a cylindrical grid 35 with a through hole 35a formed in the bottom surface. , filters 38 and 39 attached to the bottom surfaces of both grids 34 and 35, and the cylindrical case 3.
A pair of covers 36.
37, and an adsorbent chamber 3 partitioned between both filters.
3 is filled with an adsorbent 12 to form an adsorbent layer.

In addition, the cover 36 is provided with an air vent 41, and the cover 36 is provided with an air vent 41.
A diffusion chamber 40 is defined between the cover 37 and the cylindrical grid 35, an evaporative fuel population 44 and an evaporative fuel outlet 43 are provided in the cover 37, and a diffusion chamber 42 is defined between the cover 37 and the cylindrical grid 35.

In the second embodiment, the cylindrical case 31, the cylindrical grid 34.35, and the cover 36.37 are all manufactured by resin molding, and the cylindrical grid 34.35 has seven run holes 34b at its open end.

35b is formed. And this 7 tank part 34b
, 35b to the open end of the cylindrical case 31 and the cover 36, 3
It is sandwiched between the end portions of 7 and is airtightly bonded by welding each joint surface.

According to the second embodiment, as in the first embodiment, fine adsorbent powder can be prevented from leaking into the diffusion chamber 40, 42, and the cylindrical case 31, the cylindrical grid 34, 35 and the cover 36 can be prevented from leaking.
．． Since each end of 37 is airtightly joined by welding, assembly is easy.

(Effects of the Invention) According to the present invention, since the open end of the cylindrical grid is airtightly sandwiched between the open end of the cylindrical case and the end of the cover, fine powder of the adsorbent is dispersed inside the cylindrical case. Even if fine adsorbent powder enters between the cylindrical case and the cylindrical grid through the gap formed between the peripheral surface and the end of the filter, it can be prevented from leaking into the diffusion chamber.

Therefore, there is no need to provide a tightening margin for the filter, so the accuracy of the external dimensions of the filter can be relaxed.

Further, even if the cross-sectional shape of the cylindrical case is irregular, there is no need to tighten the filter, so the filter assembly becomes easy and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the invention, and FIG. 2 is a sectional view showing a second embodiment of the invention. 11.31... Cylindrical case, 12... Adsorbent, 14
, 15.34.35... Cylindrical grid, 14a, 15
a, 34a, 35a...through hole, 16.1? , 36.
37...Cover 18.19.38.39...Filter, 21.41...Atmospheric port, 23.43...Evaporative fuel inlet, 24.44...Evaporative fuel outlet.

Claims (1)

[Claims] A cylindrical case with both ends open, a pair of cylindrical grids each having a number of through holes formed in the bottom surface and having one end open and inserted into the inside of the cylindrical case, each affixed to the bottom surface of both grids. The method comprises a filter and a pair of covers respectively attached to both opening ends of the cylindrical case, an adsorbent is filled between the two filters to form an adsorbent layer, and an air vent is provided in the one cover. A vaporized fuel is provided, and a diffusion chamber is defined between the cover and the one grid, an evaporative fuel inlet and an evaporative fuel outlet are provided in the other cover, and a diffusion chamber is defined between the cover and the other grid. 1. A canister for adsorption of evaporated fuel, characterized in that an open end of the cylindrical grid is airtightly sandwiched between an open end of the cylindrical case and an end of the cover.