JPH09112356A - Canister for vaporizing fueltreatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent sinking and deviation of a heat accumulation body and to improve adsorption performance and desorption performance of activated carbon. SOLUTION: Porous plates 16 and filter members 17 are disposed in a lamination state at both the upper and lower ends of a cup-form case body 11 and a space between opposite filter members 17 forms an adsorption chamber C2 . In the adsorption chamber C2 , activated carbon layers A formed of a pellet-form activated carbon 18 and pellet-form heat accumulation substances 19 having thermal conductivity and a specific heat higher than those of the activated coal are alternately disposed and stacked in a plurality of stages in such a manner that a topmost part and a lowermost part form the activated carbon layer A, and the stacked body is held in such a state to be energized in an up state through the force of a coil spring 20 on a cover body 12. Heat generated at the activated carbon 18 during adsorption of vaporizing fuel is absorbed by the heat accumulation substances 19 and meanwhile, during desorption, the heat of the heat accumulation substance 19 is transferred to the activated carbon 18 and adsorption performance and desorption performance of the activated carbon are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a canister for adsorbing evaporated fuel generated in a fuel storage chamber such as a fuel tank mounted on a vehicle.

[0002]

2. Description of the Related Art Generally, in a vehicle, a vaporized fuel generated in a fuel storage chamber such as a fuel tank or a float chamber of a carburetor is used as a carbon canister (hereinafter simply referred to as a canister) when the vehicle is stopped or traveling due to pollution control measures. Guided air is adsorbed on activated carbon, which is an adsorbent, and when the vehicle is running, the negative pressure in the intake pipe is used to take in the atmosphere into the canister, and the adsorbed fuel is released to bring the engine into the operating state with the control valve interposed. It is designed to be sent to the intake pipe.

A canister C used in the above system is as shown in FIG. 5, which comprises an iron plate or a cup-shaped case body 1 made of a synthetic resin such as nylon, polypropylene, or polyethylene, and a lid body 2 for closing the open end thereof. Therefore, the stepped end wall 1a on the evaporative fuel intake side is provided with an inlet pipe 3 connected to the fuel tank or the float chamber of the carburetor and an outlet pipe 4 for the separated fuel connected to the intake pipe by piping members. On the other hand, the lid 2 has an atmospheric pipe 5 for taking in the atmosphere.
The inside of the case body 1 is provided with an evaporative fuel introduction chamber C ₁ or an atmosphere introduction chamber C ₃ of a required area at both ends on the end wall side and the lid side, and is the same as the case body. A perforated plate 6 made of an iron plate or a synthetic resin and a filter member 7 made of a nonwoven fabric or an open-cell urethane resin are arranged so as to overlap with each other with the filter member 7 inside, and the space between the two filter members 7 has a required volume. _{It is 2} .

The adsorption chamber C ₂ is filled with a predetermined amount of particulate activated carbon 8. Generally, the activated carbon generates heat during adsorption of the evaporated fuel and its temperature rises to lower its adsorption ability. When the adsorbed fuel is desorbed, heat is taken away and the temperature is lowered to lower the desorption ability. Therefore, the activated carbon 8 has a particle shape made of iron or other minerals having a higher thermal conductivity and specific heat. The heat storage body 9 is mixed and filled in the adsorption chamber C ₂ , thereby absorbing the heat of the activated carbon at the time of adsorption and supplementing the heat to the activated carbon at the time of desorption so as to prevent the adsorption and desorption performance of the evaporated fuel from decreasing. An apparatus according to Japanese Patent Laid-Open No. 63-246462 has been proposed.

[0005]

By the way, in the above-mentioned conventional apparatus, the activated carbon 8 and the regenerator 9 such as iron are randomly mixed, so that the activated carbon 8 in the form of particles and the regenerator are stored in the case body 1. When filling or using 9 the heat storage body 9 having a much larger specific gravity than the activated carbon 8 is likely to sink and be unevenly distributed downward, and it is difficult to evenly distribute the activated carbon 8 and the heat storage body 9. If the distribution of H is not uniform, the effect of suppressing the temperature change of the activated carbon 8 at the time of adsorbing and desorbing the evaporated fuel is great in the portion where the mixing ratio of the heat storage body 9 is large, but the amount of the activated carbon 8 decreases and the mixing ratio increases. In the portion where the amount is small, the effect of suppressing the temperature change of the activated carbon 8 is small, so that the sufficient performance as a canister cannot be exhibited.

[0006] Therefore, it is an object of the present invention to maintain a constant distribution state in which the heat storage body is not unevenly settled with respect to the activated carbon so as not to deteriorate the adsorption / desorption performance as a canister for the evaporated fuel.

[0007]

Based on the above-mentioned problems, the present invention has a cup-shaped case body having at least an inlet for evaporated fuel and an outlet for desorbed fuel, and an open end thereof with or without an atmospheric air inlet. As a canister that consists of a lid that closes the case and forms an adsorption chamber in the case main body, the adsorption chamber has an activated carbon layer made of pellet-shaped activated carbon, and a pellet-shaped heat storage that has higher thermal conductivity and specific heat than activated carbon. A heat storage layer composed of a body and having a thickness smaller than that of the activated carbon layer is alternately laminated in a plurality of stages so that the uppermost part and the lowermost part are the activated carbon layer, and this is held by spring-biasing from the lid side. And interposing a net material between the activated carbon layer and the heat storage layer, the activated carbon layer and the heat storage layer are alternately stacked in a plurality of layers, and are held by spring-biasing from the lid side. And the case body And it is characterized in that broken down in the first adsorption chamber and second adsorption chamber mutually communicate with each other at the lid side by the partition walls extending lid side from the end wall.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a canister C according to the present invention, which is a cup-shaped case body 11
The lid 12 for closing the open end is made of an iron plate or a synthetic resin such as nylon, polypropylene, polyethylene or the like. The stepped end wall 11a of the case body 11 on the evaporative fuel intake side is provided with a fuel tank or a pipe member by a piping member. An inlet pipe 13 connected to the float chamber of the carburetor is provided, an outlet pipe 14 for the separated fuel connected to the intake pipe is provided, and the lid 12 is provided with an atmospheric pipe 15 for taking in the atmosphere.

Inside the case body 11, there is an end wall 11a.
1 and the lid 12 side, the case body 1 is provided with an evaporative fuel introduction chamber C ₁ or an atmosphere introduction chamber C ₃ of a required area interposed therebetween.
1, a perforated plate 16 made of an iron plate or a synthetic resin, and a filter member 17 made of a nonwoven fabric or an open-cell urethane resin are arranged so that the filter members 17 are overlapped on the inner side, respectively. The adsorption chamber C ₂ has a predetermined volume.

Inside the adsorption chamber C ₂ , a pellet-like activated carbon 18 having a diameter of about 2 mm and a length of about 3 to 4 mm or a spherical pellet of about 2 to 3 mm in diameter is provided. A heat storage material 19 which is in the form of pellets and is heavier than activated carbon and has a large thermal conductivity and specific heat, that is, a heat storage material 19 such as aluminum, alumina, iron, stainless steel, copper or ceramics, glass, etc.
However, they are filled in the following state by alternately forming layers.

In consideration of adsorption and desorption of vaporized fuel and heat conductivity, the activated carbon layer A is located at the uppermost and lowermost portions, and the heat storage layer B is located in the middle thereof. The thickness of A is 4 to 10 pieces of activated carbon 18 (if it is more than this, the heat conductivity to the heat storage material is poor, and if it is less than this, the filling amount of activated carbon is small). Of the heat accumulating body 19 is 1 to 3 pieces (if it is more than this, the amount of activated carbon is reduced and the adsorption performance is deteriorated), the layers are alternately stacked in layers and the lid 12 and A coil spring 20 arranged between the lower porous plates 17 is pressed and held upward so as to maintain a constant laminated state. In this case, the ratio of the thickness of the heat storage layer B to the activated carbon layer A is selected within the above range, but it is preferably about 1/3 to 1/2 from the viewpoint of improving the adsorption / desorption performance.

In filling the activated carbon 18 and the heat storage body 19, the case body 11 is turned upside down and the upper porous plate 16 and the filter member 17 are sequentially inserted from the open end of the case body 11 and arranged at predetermined positions. , Then a certain amount of activated carbon 18
And the heat storage body 19 are alternately filled so as to form a plurality of layers A and B, then the lower filter member 17 and the perforated plate 16 are placed, and the coil spring 20 is placed on the perforated plate 16. The lid 12 is provided, the lid 12 is applied from above, and the case 12 is airtightly joined by welding or welding.

The inlet pipe 13 is used by connecting it to the fuel tank and the float chamber of the carburetor through the piping member and the outlet pipe 14 is connected to the intake pipe. The evaporated fuel generated in the fuel tank or the float chamber enters the fuel introduction chamber C ₁ of the case body 11 from the inlet pipe 13 through the piping member, is dispersed, and passes through the perforated plate 16 and the filter member 17 on the end wall side. It enters into the adsorption chamber C ₂ Te is adsorbed by the activated carbon 18 of the activated carbon layer a while passing through the activated carbon layer a and the heat storage layer B of a plurality of stages,
Also, when the vehicle is running, the atmosphere is sucked from the atmosphere pipe 15 in accordance with the operating state of the engine, enters the adsorption chamber C ₂ via the perforated plate 16 and the filter member 17 on the lid side, and sequentially passes therethrough. Activated carbon of each activated carbon layer A 18
The fuel adsorbed on the fuel cell is released and is sent to the intake pipe from the outlet pipe 14 across the other filter member 17 and the perforated plate 16.

In the process, the heat of adsorption generated on the activated carbon 18 of each activated carbon layer A at the time of adsorbing the evaporated fuel is absorbed by the heat storage body 19 of each heat storage layer B existing between the activated carbon layers A, and at the time of desorption. The heat held by the heat storage body 19 of the heat storage layer B is transferred to the activated carbon 18 of each activated carbon layer A, and the temperature rise or decrease of the entire activated carbon 18 is suppressed, and the activated carbon 1
The adsorption performance and the desorption performance of No. 8 are maintained high.

In FIG. 2, the width of the cup-shaped case body 11 and the lid 12 that closes the open end thereof is increased, and the inside thereof extends from the stepped end wall 11a on the evaporative fuel intake side to the lid 12 side. An example in which the partition wall 21 is divided into _two so as to form a first adsorption chamber C ₂ and a second adsorption chamber C ₂ ′, and the overall length of the adsorption chamber is increased to improve the performance of the canister. In this case, the end wall 11a on one side (left side in the drawing) of the partition wall 21 is provided with the inlet pipe 13 for evaporated fuel and the outlet pipe 14 for desorbed fuel, and the other side portion (right side) for intake of atmosphere. The atmospheric pipe 15 is provided, the inlet pipe 13 is connected to the fuel tank and the float chamber by the piping member, and the outlet pipe 14 is connected to the intake pipe.

Inside the end wall 11a, the partition wall 21
The one side constitutes an evaporative fuel introduction chamber C ₁ , and the other side constitutes an atmosphere introduction chamber C ₃ , and these introduction chambers C _1, C ₃ and
A perforated plate 16 and a filter member 17 are separately arranged at the boundary between the second adsorption chamber C ₂ and the adsorption chamber C ₂ ′, while a series of filter members 17 are provided on the open end side of the case body 11. The perforated plate 16 is provided, and the series of the perforated plate 16 and the lid 12 are arranged.
A communication chamber C ₄ is formed between the first and second adsorption chambers C ₂ and C ₂ ′ on the open end side so that the entire adsorption chamber is elongated. , The second adsorption chamber C ₂ ,
The activated carbon layer A and the heat storage layer B are alternately arranged in C ₂ ′ as described above, and they are compressed toward the end wall 11 a by the coil spring 20 arranged in the communication chamber C ₄ . Is held.

In this case, the evaporated fuel flowing in from the inlet pipe 13 or the atmospheric air taken in from the atmospheric pipe 15 both makes a U-turn through the communication chamber C ₄ in the case body 11, but the evaporated fuel is adsorbed. By the transfer of heat between the activated carbon 18 and the heat storage body 19 at the time of separation and at the time of separation,
Suppressing the temperature change of the activated carbon 18 and improving its adsorption capacity and desorption capacity is no different from the above example.

FIG. 3 shows that the case body 11 is of the same type as that of FIG. 1, and the adsorption chamber C ₂ between the upper and lower filter members 17 is filled with the activated carbon 18 in pellet form and the heat storage body 19 in layers. , A mesh material 22 having an opening of about 1 to 2 mm between the activated carbon layer A and the heat storage layer B as described above (a wire mesh is preferable from the viewpoint of heat conductivity, but the thickness of the mesh and the wire can be used for heat conduction). If it is selected so as not to interfere with the glass fiber,
This shows an example in which the activated carbon layers A and the heat storage layers B are alternately stacked in a plurality of layers with a synthetic fiber intervening therebetween, and in this case, the mesh of the mesh material 22 (in case of wire mesh, mesh) Heat between the activated carbon 18 and the heat storage body 19 is transmitted through the body itself and the mesh, and even if vibration or shock of the vehicle or engine is transmitted to the canister C during use, the heat storage body 19 having a large specific gravity is generated. It is possible to more surely prevent uneven settlement.

Furthermore Figure 4 cases the width of the main body 11 is increased as in FIG 2, the internal and the first adsorption chamber C ₂ mutually communicated with each other in the cover 12 side by the partition wall 21 and the second adsorption chamber Divide into C ₂ ′ and lengthen the whole adsorption chamber,
In the adsorption chambers C ₂ and C ₂ ′, the activated carbon layers A and the heat storage layers B are alternately stacked in a plurality of layers with the net material 22 interposed between the activated carbon layers A and the heat storage layers B. An example is shown.

In place of the perforated plate 16 disposed in the upper part of the case body 11, a large number of spacer projections are provided from the end wall 11a of the case body, and the filter member 1 is provided inside thereof.
7, the filter member 17 may be omitted by providing a perforated plate having a small hole diameter. Further, although the present invention has been described in the above example as processing evaporative fuel generated in the fuel tank when the vehicle is stopped or running, the present invention is also used when processing evaporative fuel generated when fueling the fuel tank. In the illustrated example, the inlet of vaporized fuel, the outlet of desorbed fuel, and the inlet of atmospheric air are shown in the form of pipes, but if these are opened in the case body 11 or the lid 12, Well, it does not have to be pipe-shaped. The planar shape of the case body 11 may be a square shape, a circular shape, an elliptical shape, or the like.

[0021]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, as a canister for processing evaporated fuel in a vehicle, an adsorption chamber in a case body has an activated carbon layer made of pelletized activated carbon and a thermal conductivity and a specific heat larger than that of activated carbon. A heat storage layer composed of pellet-shaped heat storage and having a smaller thickness than the activated carbon layer is alternately stacked in multiple layers so that the uppermost and lowermost layers are the activated carbon layer, which are spring-biased from the lid side. Since the case is filled with activated carbon and the heat storage body, it is not the same as in the conventional case where they are mixed together, so the heat storage body sinks due to the difference in specific gravity. There is no fear of uneven distribution, and since the same shape and weight are put together in layers even during use, the laminated state of the activated carbon layer and the heat storage layer is maintained without being disturbed, and when adsorbing fuel or When leaving It is possible to suppress the temperature change of sex coal, it can be used for long-term to improve its adsorption capacity withdrawal capacity. By interposing a net material between the activated carbon layer and the heat storage layer, it is possible to more reliably maintain a constant laminated state of the activated carbon layer and the heat storage layer even when subjected to vibration or shock. The effect of suppressing the temperature change of the activated carbon is also increased.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of a canister according to the present invention.

FIG. 2 is a cross-sectional view of an example in which the width of the case body is increased.

FIG. 3 is a cross-sectional view of an example in which a net material is interposed.

FIG. 4 is a cross-sectional view of an example in which a net material is interposed and the width of the case body is increased.

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

[Explanation of symbols]

11 Case Main Body 12 Lid Body 13 Inlet Pipe 14 Outlet Pipe 15 Atmospheric Pipe 16 Perforated Plate 17 Filter Member 18 Activated Carbon 19 Heat Storage Material 22 Net Material A Activated Carbon Bed B Heat Storage Bed C Canister C ₂ Adsorption Chamber

Continuing from the front page (72) Inventor Kazumi Yamazaki 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside of Honda R & D Co., Ltd. (72) Takeshi Hara 1-4-1 Chuo, Wako-shi, Saitama Co., Ltd. Honda Technical Research Institute

Claims (3)

[Claims] 1. A cup-shaped case main body having at least an inlet for evaporated fuel and an outlet for desorbed fuel, and a lid for closing an open end thereof with or without an air intake.
In the canister that forms the adsorption chamber in the case body,
In the adsorption chamber, an activated carbon layer made of pellet-shaped activated carbon, and a heat storage layer having a smaller thickness than the activated carbon layer made of a pellet-shaped heat storage material having a larger thermal conductivity and specific heat than the activated carbon, and the uppermost part. A canister for evaporative fuel treatment, characterized in that a plurality of layers are alternately laminated so that the lowermost part is an activated carbon layer, and the layers are held by spring-biasing from the lid side. 2. A net material is interposed between the activated carbon layer and the heat storage layer, the activated carbon layer and the heat storage layer are alternately stacked in a plurality of layers, and the layers are biased by a spring from the lid side. The canister for processing evaporated fuel according to claim 1, wherein the canister is held. 3. The inside of the case body is divided into a first adsorption chamber and a second adsorption chamber, which communicate with each other on the lid side, by a partition wall extending from the end wall toward the lid body. A canister for processing evaporated fuel according to 1 or 2.