JP2011169219A - Canister - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a canister to treat gasoline vapor capable of promoting dispersion of gasoline vapor and enhancing the adsorbing efficiency of the gasoline vapor using an adsorbent by installing a buffer plate which restricts the flow of papers in an adsorption chamber. <P>SOLUTION: The buffer plate 43 furnished with a plurality of through holes 44A and 44B to put a first region and a second region in mutual communication, is installed in a cavity chamber which partitions a first adsorption chamber into the first and second regions. The buffer plate 43 is formed so that the aperture rate of the through holes 44B on the tank port side is smaller than that of the through holes 44A on the purge port side. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a canister for treating evaporated fuel (for example, gasoline vapor) generated in a fuel tank.

  A vehicle represented by an automobile or the like is provided with a canister as an evaporative fuel processing device that processes gasoline vapor (evaporated gasoline) in a fuel tank. The canister generally includes a housing formed in a hollow container shape, and an adsorbent disposed in the housing. The housing includes a tank port for sucking gasoline vapor generated in the fuel tank and an air port for sucking air. The adsorbent is configured using activated carbon or the like, and adsorbs gasoline vapor or desorbs gasoline vapor. That is, the gasoline vapor flows into the canister when the vehicle is stopped, temporarily adsorbs to the adsorbent, and is desorbed from the adsorbent by purging when the engine is operating.

  In order to improve the performance of the canister, it is effective to improve the desorption efficiency of gasoline vapor by purging. Regarding this desorption efficiency, a decrease in the temperature of the activated carbon during desorption and non-uniformity of the purge gas flow in the passage cross section are major factors that lower the desorption efficiency.

  In order to improve such desorption efficiency, for example, in the canister of Patent Document 1, the adsorbent is divided into a plurality of layers by the gaps. The presence of a gap between adjacent adsorbing layers can alleviate the propagation of heat between adjacent adsorbing layers, and as a result, the reduction in desorption efficiency due to temperature changes can be reduced.

  Further, the concentration and temperature of gasoline vapor passing through the adsorption layer in the housing are usually different at positions in the cross-sectional direction, for example, near the center and near the outer periphery. However, the concentration and temperature of gasoline vapor passing therethrough can be made uniform in the gap. Therefore, the difference in the adsorption / desorption efficiency of gasoline vapor in the cross-sectional direction is reduced, and as a result, the adsorption / desorption efficiency is improved.

JP2007-146793

  However, even with such a canister, in the adsorption layer into which gasoline vapor flows directly from the tank port, a portion (for example, a portion on the purge port side) where the gasoline vapor that has flowed in is difficult to reach occurs. Inside, there was an adsorbent material that could not substantially adsorb gasoline vapor. In particular, since the flow rate of gasoline vapor during refueling is high, sufficient diffusion does not occur in the adsorption layer, and as a result, efficient adsorption of gasoline vapor has not been achieved.

  The present invention has been made in view of such circumstances. The problem to be solved by the present invention is that in a canister for processing gasoline vapor generated in a fuel tank, the flow in the housing of the gasoline vapor that has flowed in can be controlled and diffused sufficiently, thereby making it more efficient. It is to realize the adsorption of gasoline vapor. In addition, this makes it possible to reduce the amount of adsorbent by increasing the efficiency of adsorption of gasoline vapor, thereby reducing the size of the apparatus and the manufacturing cost.

In order to solve the above problems, the canister according to the present invention employs the following means.
That is, the canister according to the first aspect of the present invention includes an adsorption chamber filled with an adsorbent for adsorbing and desorbing evaporated fuel in a fuel tank in a chamber defined by the housing, and the adsorption chamber housing. The tank port and the purge port connected to the adsorption chamber are arranged in parallel and spaced apart on the same plane of the housing, and the adsorption chamber is arranged in the first region along the flow direction of the evaporated fuel flowing from the tank port. And the second region, the canister is formed by being divided by the space portion, and the space plate has a perforated plate in which a plurality of through holes capable of communicating between the first region and the second region are formed. The through hole formed in the perforated plate is formed so that the opening rate by the through hole located on the tank port side is smaller than the opening rate by the through hole located on the purge port side. Special To.

  According to this canister, the presence of the perforated plate between the first region and the second region can partially inhibit the flow of gasoline vapor, resulting in the diffusion of gasoline vapor in the adsorption chamber. Can be promoted. Further, since the perforated plate is formed so that the opening ratio is small on the tank port side, the gasoline vapor flowing from the tank port easily flows to the purge port side having a large opening ratio. By regulating the flow of the gasoline vapor in the adsorption chamber in this way, the gasoline vapor can be diffused to a portion where the conventional gasoline vapor has not reached and can be adsorbed by the adsorbent. Therefore, according to this canister, it is possible to reduce the amount of adsorbent required by improving the adsorption efficiency of gasoline vapor, thereby realizing miniaturization of the canister and reduction in manufacturing cost.

  A canister according to a second invention is the canister according to the first invention, wherein the adsorbent filled in the first region of the adsorption chamber is crushed coal.

  According to this canister, since the adsorbent filled in the first region is crushed coal having a small particle size, the airflow resistance is large compared to a case where granulated coal having a large particle size is filled. Therefore, it is possible to promote sufficient diffusion of the gasoline vapor by reducing the flow rate of the gasoline vapor, and as a result, it is possible to improve the adsorption efficiency.

  A canister according to a third invention is a canister according to the first or second invention, wherein the adsorption chamber is filled with an adsorbent mixed with a heat storage material.

  According to this canister, since the adsorbent is mixed with the heat storage material, the temperature rise or temperature drop of the adsorbent during adsorption or desorption of gasoline vapor can be mitigated. Therefore, it is possible to reduce a decrease in the adsorption / desorption performance of the adsorbent due to a temperature change.

  A canister according to a fourth aspect is the canister according to the third aspect, wherein the mixing ratio of the heat storage material to the adsorbent is such that the first region is smaller than the second region.

  In a canister provided with a perforated plate, the flow of purge gas in the adsorption chamber is also restricted, so there is a concern that the desorption efficiency of gasoline vapor in the second region will be lowered. However, according to the present invention, since the mixing ratio of the heat storage material to the adsorbent in the second region is larger than the mixing rate in the first region, it is possible to improve the gasoline vapor desorption efficiency in the second region. Further, it is possible to compensate for a decrease in desorption efficiency due to the provision of the porous plate.

  A canister according to a fifth invention is a canister according to any one of the first to fourth inventions, wherein a heater is disposed on the side of the perforated plate having a smaller aperture ratio in the second region of the adsorption chamber. It is characterized by.

  In the second region of the adsorption chamber, since the flow rate of the purge gas is reduced by providing the porous plate toward the side where the aperture ratio of the porous plate is smaller, the adsorption efficiency of the adsorbent is greatly reduced. However, according to the present invention, since the heater is disposed on the side of the aperture plate where the aperture ratio is small in the second region, it is possible to mitigate the temperature decrease of the adsorbent when the gasoline vapor is desorbed by the heater. It is possible to alleviate a decrease in desorption efficiency in the region. Therefore, even if the flow rate of the purge gas is reduced by providing the perforated plate, the gasoline vapor can be sufficiently desorbed from the adsorbent.

A canister according to a sixth invention is a canister according to any one of the first to fourth inventions, wherein a second adsorption chamber different from the adsorption chamber is connected to the second region of the adsorption chamber. And an atmospheric port is provided in the second adsorption chamber.
According to the present invention, the gasoline vapor that has flowed into the canister can be more reliably adsorbed by the adsorbent, and the amount of gasoline vapor discharged into the atmosphere can be reduced.

According to the canisters according to the first and second inventions, the gasoline vapor can be diffused in the adsorption chamber by regulating the flow of the gasoline vapor, and the gasoline vapor can be efficiently adsorbed to the adsorbent. As a result, the required amount of adsorbent can be reduced, thereby realizing a reduction in the size of the canister and a reduction in manufacturing cost.
According to the canister according to any one of the third to fifth aspects of the invention, the desorption efficiency in the adsorption chamber, particularly in the second region, is improved so that the gasoline can be sufficiently used even with the flow rate of the purge gas reduced by providing the perforated plate. The vapor can be detached from the adsorbent.
According to the sixth invention, gasoline vapor that cannot be adsorbed by the adsorbent in the adsorption chamber can be adsorbed by the adsorbent disposed in the second adsorption chamber different from the adsorption chamber. The amount of gasoline vapor discharged can be reduced.

FIG. 1 is a cross-sectional view of a canister according to the first embodiment. FIG. 2 is a top view of the buffer plate in the canister of FIG. FIG. 3 is a top view of the buffer plate according to the second embodiment. FIG. 4 is a top view of the buffer plate according to the third embodiment. FIG. 5 is a cross-sectional view of a canister according to the fourth embodiment. FIG. 6 is a cross-sectional view of a canister having only the first adsorption chamber according to the present invention.

Hereinafter, a first embodiment for carrying out the present invention will be described with reference to the drawings. The canister described below is an evaporative fuel processing apparatus installed in an automobile or the like, and processes gasoline vapor (evaporated fuel) generated in the fuel tank.
First, the canister 10 will be described with reference to FIG. FIG. 1 is a cross-sectional view of the canister 10.
The canister 10 shown in FIG. 1 processes gasoline vapor (evaporated gasoline) generated in a fuel tank (not shown). The canister 10 includes a housing 20 and an adsorbent 30 disposed in the housing 20.

As shown in FIG. 1, the housing 20 is formed in a hollow container shape. The housing 20 is provided with three ports that communicate between the inside and outside of the housing 20.
That is, the housing 20 is provided with a tank port 21 for introducing gasoline vapor generated in the fuel tank into the canister 10. The tank port 21 is connected to the fuel tank via a hose (not shown).
Further, a purge port 22 for discharging gasoline vapor from the canister 10 to the outside is provided in the housing 20 in parallel and spaced apart from the tank port 21 on the same plane. The purge port 22 is connected to the engine via a hose (not shown).
In addition, the housing 20 is provided with an atmospheric port 23 for introducing outside air as the atmosphere into the canister 10. The atmospheric port 23 is connected to an outside air inlet through a hose (not shown).

A partition wall 24 is provided in the housing 20 so as to be demarcated into two spaces of the first adsorption chamber 11 and the second adsorption chamber 12. The partition wall 24 is provided so as to be integrated with the housing 20.
A tank port 21 and a purge port 22 are connected in communication with the first adsorption chamber 11 separated by the partition wall 24, and an atmospheric port 23 is connected in communication with the second adsorption chamber 12. The first adsorption chamber 11 and the second adsorption chamber 12 are in communication with each other via a communication chamber 13 disposed on the opposite side to the three ports 21, 22, and 23 described above.

  In addition, the first adsorption chamber 11 is formed with a void chamber 42 defined by filters 40 and 41 made of nonwoven fabric or the like, and the first adsorption chamber 11 is along the flow direction of the gasoline vapor flowing from the tank port 21. The first region 11A and the second region 11B are divided by the gap chamber 42.

  In order to prevent the gasoline vapor that has flowed into the housing 20 from the tank port 21 from escaping from the purge port 22 adjacent to the tank port 21, the first adsorption chamber 11 is inserted between the tank port 21 and the purge port 22. A partition wall 25 protruding toward the center is provided.

When the gasoline vapor is adsorbed, the gasoline vapor enters the housing 20 from the tank port 21, moves sequentially to the first adsorption chamber 11, the communication chamber 13, and the second adsorption chamber 12, and exhausts from the atmospheric port 23. Is done.
Conversely, when the gasoline vapor is discharged, the atmosphere (outside air) enters the housing 20 from the atmosphere port 23 and sequentially moves to the second adsorption chamber 12, the communication chamber 13, and the first adsorption chamber 11. The air is exhausted from the purge port 22.
That is, the canister 10 has a U-shaped flow structure in which the gasoline vapor flow direction is U-shaped.

Here, the void chamber 42 is provided with a buffer plate (perforated plate) 43 that suppresses the diffusion of gasoline vapor between the first region 11A and the second region 11B of the first adsorption chamber 11. The first region and the second region communicate with each other through a plurality of through holes provided in the. By providing the buffer plate 43, the flow of the gasoline vapor flowing in from the tank port 21 from the first region 11A to the second region 11B is restricted. For this reason, the gasoline vapor stays in the first region 11A for a longer time, diffuses to a wider range in the first region 11A, and is efficiently adsorbed by the adsorbent.
The gap chamber 42 and the buffer plate 43 are preferably positioned so that the length in the flow direction of the first adsorption chamber 11: the length in the flow direction of the first region is 3: 2 to 4: 1.

Further, the through hole of the buffer plate 43 is provided so that the aperture ratio per unit area is larger on the purge port 22 side than on the tank port 21 side. As a result, the airflow resistance when the gasoline vapor passes through the buffer plate 43 is smaller on the purge port 22 side than on the tank port 21 side, so that the gasoline vapor flowing in from the tank port 21 is directed toward the purge port 22 side having a large opening ratio. And flow easily.
When the opening ratio of the buffer plate 43 is uniform, the amount of gasoline vapor flowing in from the tank port 21 is less diffused to the purge port 22 side in the first region 11A of the first adsorption chamber 11, and the vicinity of the purge port 22 The adsorbent 30 could hardly adsorb gasoline vapor. However, by increasing the opening ratio of the buffer plate 43 on the purge port 22 side, it becomes easier for the gasoline vapor to flow to the purge port 22 side. Therefore, the adsorption in the vicinity of the purge port 22 where conventional gasoline vapor could not be adsorbed. Gasoline vapor can also be adsorbed to a part of the material. Therefore, gasoline vapor can be adsorbed by more adsorbents in the first region 11A, so that the gasoline vapor adsorption efficiency in the first region 11A can be improved.
Note that the through hole located on the tank port 21 side and the through hole located on the purge port 22 side in the above are distinguished depending on the distance between the tank port 21 and the purge port 22 of the through hole. However, when a partitioning means such as a partition wall 25 is provided between the tank port 21 and the purge port 22, the partitioning is made according to the region distinguished by the partitioning means.

As shown in FIG. 2, the through holes 44A and 44B of the buffer plate 43 have a circular cross section, and are closer to the purge port 22 side (left side in FIG. 2) than the through hole 44B on the tank port 21 side (right side in FIG. 2). 44A is formed to have a large diameter. As a result, the opening ratio of the buffer plate 43 on the tank port 21 side is larger than that on the purge port 22 side.
Here, the through hole only needs to be provided so that the opening ratio per unit area is larger on the purge port 22 side than on the tank port 21 side, and the shape and position thereof can take any configuration. .

The adsorbent 30 disposed in the first adsorption chamber 11 and the second adsorption chamber 12 is composed of granular activated carbon that adsorbs gasoline vapor, and more specifically, is composed of granulated coal, crushed coal, or the like. Yes. Here, crushed coal has a smaller particle size than granulated coal, and generally crushed coal has a particle size of about 0.7 mm to 2.0 mm, while granulated coal has a particle size of about 2.0 mm to 2.5 mm. It is. Therefore, the adsorption resistance of the adsorption chamber filled with crushed coal is larger than that of the adsorption chamber filled with granulated coal. Therefore, by filling the first region 11A of the first adsorption chamber 11 with crushed coal, the ventilation resistance in the first region 11A can be increased, and the diffusion of the gasoline vapor that has flowed in can be promoted.
In addition, although it is preferable to use crushed coal and granulated coal properly according to the purpose, the adsorbent is not necessarily required to use crushed coal and granulated coal properly. For example, either crushed coal or granulated coal is used. Both the first adsorption chamber 11 and the second adsorption chamber 12 may be filled.

A heat storage material can be mixed in the adsorbent 30 disposed in the first adsorption chamber 11 and the second adsorption chamber 12. As the heat storage material, various forms can be selectively used as long as they use a phase change material that absorbs and releases latent heat according to a temperature change.
For example, as the heat storage material, a fine heat storage material formed by encapsulating a phase change material that absorbs and releases latent heat in response to a temperature change in a microcapsule may be formed into a granular shape together with an appropriate binder. good.

  Here, the mixing rate of the heat storage material in the second region 11B can be made larger than the mixing rate in the first region 11A. By providing the buffer plate 43, the ventilation resistance when the purge gas flows from the second region 11B to the first region 11A is increased. Especially, the increase in the ventilation resistance is caused on the tank port 21 side where the opening ratio of the buffer plate 43 is small. It is remarkable. Due to the increase in the ventilation resistance, the flow rate of the purge gas is lowered, and there is a concern that the efficiency of desorbing the gasoline vapor from the adsorbent in the second region 11B is lowered. However, by increasing the mixing ratio of the heat storage material in the second region 11B as described above, the temperature drop when the gasoline vapor is desorbed from the adsorbent 30 in the second region is alleviated, and the gasoline vapor is desorbed. Efficiency can be improved.

According to the second embodiment of the present invention, as shown in FIG. 3, the buffer plate 43 has a through hole 44 </ b> C having a wide lateral width on the purge port 22 side (left side), and the tank port 21 side. On the right side, there is a through-hole 44D that is a square with a narrow width.
Further, according to the third embodiment of the present invention, as shown in FIG. 4, the buffer plate 43 is a quadrangle whose width becomes narrower toward the purge port 22 side (left side) and toward the tank port 21 side (right side). Through holes 44E, and a circular through hole 44F on the tank port 21 side (right side).
In FIGS. 2 to 4, only one of the plurality of through holes is provided with a reference numeral.

  Further, according to the fourth embodiment of the present invention, as shown in FIG. 5, the heater 45 is arranged on the tank port 21 side of the second region 11 </ b> B where the desorption efficiency is considered to be greatly reduced. By using the heater, the temperature drop when the gasoline vapor is desorbed from the adsorbent 30 can be mitigated, so that the gasoline vapor can be efficiently desorbed even with a small amount of purge gas.

It should be noted that the canister according to the present invention is not limited to the above-described embodiment, and can be appropriately changed without changing the gist of the present invention.
In the above embodiment, the canister 10 including the first adsorption chamber 11 and the second adsorption chamber 12 in the housing 20 is described as an example. However, the canister according to the present invention is such a canister. The form is not limited. For example, the canister according to the present invention has a first housing 60 having a first adsorption chamber and a second housing (not shown) having a second adsorption chamber and an atmospheric port as shown in FIG. These two housings may communicate with each other via a hose.

DESCRIPTION OF SYMBOLS 10 Canister 11 1st adsorption | suction chamber 11A 1st area | region 11B 2nd area | region 12 2nd adsorption chamber 13 Communication chamber 20, 60 Housing 21 Tank port 22 Purge port 23 Atmospheric port 24 Partition 25 Partition wall 30 Adsorbent 40, 41 Filter 42 Gap Chamber 43 Buffer plate 44 Through hole 45 Heater

Claims (6)

A chamber defined by the housing is provided with an adsorption chamber filled with an adsorbent that adsorbs and desorbs the evaporated fuel in the fuel tank. The housing of the adsorption chamber has a tank port connected to the adsorption chamber and a purge. Ports are spaced apart and arranged in parallel on the same plane of the housing, and the adsorption chamber is divided into a first region and a second region along the flow direction of the evaporated fuel flowing from the tank port by a space portion. Canister,
In the space portion, a perforated plate in which a plurality of through holes capable of communicating between the first region and the second region is formed is disposed,
The canister is characterized in that the through hole formed in the perforated plate is formed so that the opening ratio by the through hole located on the tank port side is smaller than the opening ratio by the through hole located on the purge port side. The canister according to claim 1,
The canister, wherein the adsorbent filled in the first region of the adsorption chamber is crushed coal. The canister according to claim 1 or 2, wherein
A canister characterized in that the adsorbing chamber is filled with an adsorbent mixed with a heat storage material. The canister according to claim 3, wherein
The canister characterized in that the mixing ratio of the heat storage material to the adsorbent is smaller in the first region than in the second region. The canister according to any one of claims 1 to 4, wherein
A canister characterized in that a heater is arranged on the side of the perforated plate having a smaller aperture ratio in the second region of the adsorption chamber. A canister according to any one of claims 1 to 5,
A second adsorption chamber different from the adsorption chamber is arranged connected to the second region of the adsorption chamber, and an atmospheric port is arranged in the second adsorption chamber. Canister.

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