JP5841360B2 - Evaporative fuel processing equipment - Google Patents

Description

  The present invention relates to an evaporative fuel processing apparatus typified by a canister that absorbs and desorbs evaporative fuel generated in a fuel tank of an automobile, for example.

  In an automobile using gasoline as fuel, a canister is generally used as an evaporative fuel treatment device in order to suppress the evaporative fuel in the fuel tank from being released into the atmosphere.

  The canister purges the inside of the canister with the air introduced from the canister air port by adsorbing the evaporated fuel generated from the fuel tank when the vehicle is stopped to the adsorbent made of activated carbon and sucking air through the canister when the engine is running. The adsorbed fuel vapor is desorbed and burned in the engine. And by this purge, the adsorption performance of the adsorbent is restored by desorption of the evaporated fuel, and the evaporated fuel can be adsorbed favorably repeatedly.

  For example, in Patent Document 1, a plurality of filling chambers filled with an adsorbent are formed in parallel in a casing, and a gas passage formed in the casing is configured to be U-shaped as a whole. A canister is disclosed in which a relatively long gas passage is formed in a relatively compact casing.

  Here, the flow of gas composed of air, evaporative fuel, and the like in the filling chamber filled with activated carbon is such that the wall boundary where the inner wall of the filling chamber contacts the activated carbon is at the center of the wall where the activated carbon contacts. Easy to flow. This is because the gap formed between the inner wall surface of the filling chamber and the activated carbon at the wall boundary is larger than the gap formed between the activated carbons at the center, and the ventilation resistance at the wall boundary is relatively This is because the gas easily flows through the wall boundary portion.

  On the other hand, if the fluid has the same ventilation resistance, the fluid also has the property of flowing through the shortest path from the inlet to the outlet.

JP 2007-146793 A

  Accordingly, like the above-mentioned canister of Patent Document 1, two or more filling chambers filled with activated carbon are formed in the casing, and these filling chambers are connected in series so that a U-shaped gas flow is formed in the casing. When the path is defined, the gas flow easily changes on the inner peripheral side of the curved portion of the flow path curved portion where the direction of the gas flow direction changes by 180 degrees or on the wall boundary of the filling chamber. The gas does not easily flow to the outer peripheral side of the curved portion of the flow path bending portion where the path becomes long or to the central portion of the filling chamber having a relatively high ventilation resistance.

  In other words, in a canister in which a U-shaped gas flow path is defined in the casing, if the gas flow in the filling chamber is biased, non-uniform adsorption / desorption of evaporated fuel will occur in the filling chamber. As compared with the case where the gas flow in the filling chamber is not biased, there is a possibility that the desorption performance and the adsorption performance of the evaporative fuel processing apparatus may be relatively lowered.

  Therefore, in the evaporated fuel processing apparatus of the present invention, the first and second filling chambers filled with the adsorbent for adsorbing and desorbing the evaporated fuel are formed in parallel in the casing, and one end side of the first filling chamber. A charge port connected to the fuel tank and a purge port connected to the intake system of the engine are connected, and an atmospheric port communicating with the atmosphere is connected to one end of the second filling chamber. The one end of the second filling chamber is located on the side of one end of the first filling chamber, the other end of the second filling chamber is located on the side of the other end of the first filling chamber, The other end of the filling chamber and the other end of the second filling chamber communicate with each other through a connection passage formed in the casing, and the connection passage communicates with the first filling chamber via a first screen member having air permeability. The second screen member is communicated with the second screen member having air permeability. A U-shaped gas flow path is formed in the casing from the one end side of the first filling chamber to the connection passage to one end side of the second filling chamber. A first flow path regulating member that biases one screen member toward one end of the first filling chamber; and a second flow path that biases the second screen member toward one end of the second filling chamber. A first restricting member, wherein the first flow passage restricting member allows a gas flowing in the center of the first filling chamber to flow easily in the center of the first filling chamber. An opening hole is formed, and the second flow path regulating member is a second opening hole that allows a gas flow in the center of the second filling chamber so that the gas flowing in the second filling chamber can easily flow in the center. It is characterized by being formed.

In the first flow path regulating member, a portion other than the first opening hole serves as a first blocking wall that blocks a gas flow between the first filling chamber and the connection passage, and the first opening Gas flow is allowed only from the hole, and the second flow path regulating member has a second portion that blocks the gas flow between the second filling chamber and the connection passage except for the second opening hole. becomes blocking wall, the flow of actual gas from the second opening holes that is allowed.

In addition, the first flow path regulating member has a funnel shape, and has a cylindrical first base end portion having the first opening hole and one end extending over the entire outer periphery of the first screen member. A first extension portion having a tapered shape, the other end being continuous with the first base end portion, and a plurality of second support members for supporting the first screen member on an inner wall surface of the first extension portion. 1 protruding wall is formed radially, the second flow path regulating member has a funnel shape, a cylindrical second base end portion having the second opening hole, and one end of the second screen member is an outer peripheral edge of the second screen member A second extended portion having a tapered shape, the other end being continuous with the second base end portion, and an inner wall surface of the second extended portion having the second screen a plurality of second protruding wall for supporting the member that are radially formed.

  According to the present invention, the gas flowing in the casing can easily flow in the center of the first filling chamber and the second filling chamber, so that it is possible to suppress a decrease in the desorption performance and adsorption performance of the evaporated fuel processing device, Overall, it is possible to improve the performance of the evaporated fuel processing apparatus.

  And as for the 1st, 2nd flow-path control member, if parts other than a 1st opening hole and a 2nd opening hole respectively become the interruption | blocking wall which interrupts | blocks the gas flow between a filling chamber and a connection channel | path. The gas flowing in the casing can flow more easily in the center of the first filling chamber and the second filling chamber.

  Further, the first and second flow path regulating members are provided with a plurality of first and second projecting walls in a radial manner, so that the first and second flow path regulating members are the entirety of the first and second screen members. Can be stably supported.

Explanatory drawing which showed typically the whole structure of the evaporative fuel processing apparatus which concerns on this invention. The perspective view of the flow-path control member which is the principal part of this invention. Explanatory drawing which showed typically the whole structure of the evaporative fuel processing apparatus of a comparative example. Explanatory drawing which showed typically other embodiment of the flow-path control member. Explanatory drawing which showed typically other embodiment of the flow-path control member. Explanatory drawing which showed typically other embodiment of the flow-path control member. Explanatory drawing which showed typically the reference example of the flow-path control member. Explanatory drawing which showed typically the reference example of the flow-path control member.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an evaporative fuel processing apparatus 1 (hereinafter referred to as a canister 1) according to a first embodiment of the present invention.

  The casing 2 of the canister 1 is made of a resin material, and generally includes a main case 3 and a cap 4 that closes an opening on the other end side in the longitudinal direction of the main case 3.

  The main case 3 is an abbreviation in which a purge port 5 connected to an intake system of an engine (not shown) and a charge port 6 connected to a fuel tank (not shown) are provided adjacent to each other at the center on one end side. A cylindrical elongated first cylindrical portion 7 and an elongated second cylindrical portion 9 provided with an atmospheric port 8 communicating with the atmosphere at the center on one end side are provided. The other end of the first tubular portion 7 and the other end of the second tubular portion 9 are each open and closed by the cap 4 described above.

  The first cylindrical portion 7 and the second cylindrical portion 9 are arranged so as to be adjacent to each other. More specifically, one end of the second cylindrical portion 9 is positioned on the side of one end of the first cylindrical portion 7, and the second cylindrical portion 9 is positioned on the side of the other end of the first cylindrical portion 7. The other end is located. The main case 3 has a substantially box-shaped rectangular parallelepiped shape as a whole.

  First and second filling chambers 12 and 13 having a circular cross section filled with activated carbon 11 as an adsorbent for adsorbing and desorbing evaporated fuel are contained in the first cylindrical portion 7 and the second cylindrical portion 9. Are formed respectively.

  The other end of the first filling chamber 12 and the other end of the second filling chamber 13 are connected via a connection passage 14, and the inside of the casing 2 has a substantially U-shaped passage structure that is folded back at the connection passage 14. ing.

  The connection passage 14 communicates with the other end of the first filling chamber 12 via the first screen member 15 having air permeability, and the other end of the second filling chamber 13 via the second screen member 16 having air permeability. Communicated with.

  One end side of the first filling chamber 12 communicates with the charge port 6 and the purge port 5 through a third screen member 17 having air permeability. Further, one end side of the second filling chamber 13 communicates with the atmospheric port 8 through a fourth screen member 18 having air permeability.

  Here, each screen member 15-18 consists of urethane or a nonwoven fabric, and has the function to hold | maintain, preventing the fall of the activated carbon 11 which is an adsorbent.

  The first screen member 15 is urged toward one end side of the first filling chamber 12 by the first flow path regulating member 20 that receives the spring force of the spring 19 that is an elastic member. The second screen member 16 is urged toward one end side of the second filling chamber 13 by the second flow path regulating member 22 that receives the spring force of the spring 21 that is an elastic member.

  The first flow path regulating member 20 and the second flow path regulating member 22 are members that are substantially similar to each other, and circular opening holes 23 and 24 are respectively formed in the center thereof.

  More specifically, as shown in FIGS. 1 and 2, the first flow path regulating member 20 has a funnel shape, a cylindrical first base end portion 26 having a first opening hole 23, and one end at a first end. A first extended portion 27 having a tapered shape and supporting the outer peripheral edge of the screen member 15 over the entire circumference, the other end being continuous with the first base end portion 26, and the inner wall surface of the first extended portion 27 A plurality of first projecting walls 28 that support the central portion of the first screen member 15 are formed radially.

  The outer diameter of one end of the first expansion portion 27 is set to be approximately equal to the inner diameter of the first filling chamber 12. In addition, the portion other than the first opening hole 23 in the first flow path regulating member 20, that is, the first expansion portion 27, is a first cutoff that blocks a gas flow between the first filling chamber 12 and the connection passage 14. The first flow path regulating member 20 has a structure that allows gas flow only from the first opening hole 23.

  As shown in FIG. 1, the second flow path regulating member 22 has a funnel shape, a cylindrical second base end portion 30 having a second opening hole 24, and one end that is the outer peripheral edge of the second screen member 16. A taper-shaped second extended portion 31 that is supported over the entire circumference and the other end is continuous with the second base end portion 30, and a second screen member is provided on the inner wall surface of the second extended portion 31. A plurality of second projecting walls 32 supporting the central portion of 16 are formed radially.

  The outer diameter of one end of the second expansion portion 31 is set to be substantially equal to the inner diameter of the second filling chamber 13. Further, the portion other than the second opening hole 24 in the second flow path regulating member 22, that is, the second expansion portion 31, is a second cutoff that blocks the gas flow between the second filling chamber 13 and the connection passage 14. The second flow path regulating member 22 has a structure that allows the gas flow only from the second opening hole 24.

  FIG. 3 is an explanatory view schematically showing an evaporative fuel processing apparatus as a comparative example. The same components as those of the canister of FIG. 1 described above are denoted by the same reference numerals, and redundant description is omitted. The canister 40 in this comparative example has substantially the same configuration as the canister 1 shown in FIG. 1 described above, but the first screen member 15 is first formed by a disk-like perforated plate 41 that receives the spring force of the spring 19. The second screen member 16 is biased toward one end side of the second filling chamber 13 by a disc-shaped perforated plate 42 that is biased toward one end side of the filling chamber 12 and receives the spring force of the spring 21. It has become a forceful structure.

  In the canister 40 of such a comparative example, as described above, the first wall boundary where the inner wall surface of the first filling chamber 12 and the activated carbon 11 are in contact, the inner wall surface of the second filling chamber 13 and the activated carbon 11 The gap formed between the inner wall surfaces of the filling chambers 12 and 13 and the activated carbon at the boundary between the second wall surfaces contacting each other is greater than the gap formed between the activated carbons at the center of the filling chambers 12 and 13. The ventilation resistance of these wall surface boundary portions becomes relatively small, and the gas easily flows through these wall surface boundary portions. And if the fluid has the same ventilation resistance, it also has the property of flowing through the shortest path from the inlet to the outlet. Therefore, in the canister 40 of the comparative example, for example, when purging, as shown by an arrow in FIG. 3, as shown by an arrow in FIG. Gas easily flows through the boundary between the wall surfaces of the filling chambers 12 and 13.

  On the other hand, in the canister 1 of the present embodiment shown in FIGS. 1 and 2 described above, although the air resistance is relatively small at the first wall surface boundary and the second wall surface boundary, the first and first In the center of the first flow path regulating member 20 and the second flow path regulating member 22 so that the gas flowing in the two filling chambers 12 and 13 can easily flow in the center of the first and second filling chambers 12 and 13, The first and second opening holes 23 and 24 are respectively formed. In the first flow path regulating member 20 and the second flow path regulating member 22, the gas flows only from the first and second opening holes 23 and 24. It is an acceptable configuration.

  That is, when the gas flows from the connection passage 14 to the first filling chamber 12 by the purge, the gas flows into the first filling chamber 12 from the first opening hole 23 in the center of the first flow path regulating member 20, so that the first filling is performed. The gas easily flows through the center of the chamber 12, and the gas flow in the first filling chamber 12 is made uniform during the purge. When air flows from the atmospheric port 8 to the second filling chamber 13 by the purge, a path that linearly connects the atmospheric port 8 and the second opening hole 24 of the second flow path regulating member 22 flows through the second filling chamber 13. Since the gas becomes the shortest path, the gas can easily flow through the center of the second filling chamber 13, and the gas flow in the second filling chamber 13 during the purging is made uniform accordingly. In addition, when gas flows from the connection passage 14 to the second filling chamber 13 due to charging, the gas flows into the second filling chamber 13 from the second opening hole 24 in the center of the second flow path regulating member 22, so that the second filling is performed. The gas easily flows through the center of the chamber 13, and the gas flow in the second filling chamber 13 at the time of charging is made uniform. When gas flows from the charge port 6 to the first filling chamber 12 due to charging, a path linearly connecting the charge port 6 and the first opening hole 23 of the first flow path regulating member 20 flows through the first filling chamber 12. Since the gas becomes the shortest path, the gas easily flows through the center of the first filling chamber 12, and the gas flow in the first filling chamber 12 at the time of charging is made uniform.

  That is, in the present embodiment, the first and second flow path regulating members 20 and 22 make it easier for the gas flowing in the casing 2 to flow in the center of the first filling chamber 12 and the second filling chamber 13. 1, the flow of gas in the second filling chambers 12 and 13 is made relatively uniform, the decrease in the desorption performance and adsorption performance of the canister 1 is suppressed, and the performance improvement of the canister 1 is realized as a whole. be able to.

  Further, by providing the first and second flow path regulating members 20 and 22 with a plurality of first and second projecting walls 28 and 31 in a radial manner, the first and second flow path regulating members 20 and 22 The entire first and second screen members 15 and 16 can be stably supported. Therefore, in the present embodiment, a member for urging the first and second screen members 15 and 16 toward one end side of the first and second filling chambers 12 and 13, that is, the porous plate 41 in the comparative example described above. , 42 can be omitted.

The shape of the flow path regulating member applied to the present invention is not limited to the shape shown in FIGS. 1 and 2, and for example, the flow paths described above may be formed as shown in FIGS. 4 to 6 . It is possible to obtain substantially the same effect as when the regulating members 20 and 22 are used. That is, in the canister 1 in FIG. 1, a flow rate regulating member having a shape as shown in FIGS. 4 to 6 can be used instead of the flow rate regulating members 20 and 22. 7 and 8 show a reference example of the present invention.

  The flow path regulating member 50 shown in FIG. 4 has the same configuration as that in which the flow path regulating members 20 and 22 shown in FIGS. 1 and 2 are not provided with the protruding walls 28 and 32, and has a funnel shape. A cylindrical base end portion 52 having an opening hole 51 and a tapered extension portion that supports the outer peripheral edge of the screen member corresponding to one end over the entire circumference and the other end is continuous with the base end portion 52. 53. When such a flow path regulating member 50 is used, it corresponds to the porous plates 41 and 42 in the comparative example described above in order to stably support the entire first and second screen members 15 and 16. It is desirable that the members to be disposed be disposed between the flow path regulating member 50 and the first and second screen members 15 and 16, respectively.

  A flow path regulating member 60 shown in FIG. 5 has a stepped cylindrical shape, and supports a cylindrical base end portion 62 having an opening hole 61 and an outer peripheral edge of a screen member corresponding to one end over the entire circumference. The other end side has a cylindrical shape that is continuous with the base end portion 62 and has an expanded portion 63 that is larger in diameter than the base end portion 62.

  The outer diameter of the expansion part 63 is set to be approximately equal to the inner diameter of the filling chamber 12 or 13 arranged. Further, the portion other than the opening hole 61 in the flow path regulating member 60 serves as a blocking wall that blocks the flow of gas between the filling chamber 12 or 13 and the connection passage 14. The structure allows the gas flow only from the hole 61. When such a flow path regulating member 60 is used, it corresponds to the porous plates 41 and 42 in the comparative example described above in order to stably support the entire first and second screen members 15 and 16. It is desirable that the members to be disposed be disposed between the flow path regulating member 60 and the first and second screen members 15 and 16, respectively.

  A flow path regulating member 70 shown in FIG. 6 has a funnel shape and supports a cylindrical base end portion 72 having an opening hole 71 and an outer peripheral edge of a screen member corresponding to one end over the entire circumference. It has a so-called bell mouth-shaped extended portion 73 whose end side is continuous with the base end portion 72. The outer diameter of one end of the expansion part 73 is set to be substantially equal to the inner diameter of the filling chamber 12 or 13 arranged. Further, the portion other than the opening hole 71 in the flow path regulating member 70 is a blocking wall that blocks the flow of gas between the filling chamber 12 or 13 and the connection passage 14, and the flow path regulating member 70 has an opening. The structure allows gas flow only from the hole 71. When such a flow path regulating member 70 is used, it corresponds to the porous plates 41 and 42 in the comparative example described above in order to stably support the entire first and second screen members 15 and 16. It is desirable that the members to be disposed be disposed between the flow path regulating member 70 and the first and second screen members 15 and 16, respectively.

  Further, in the flow path regulating members 60 and 70 shown in FIGS. 5 and 6, a plurality of projecting walls that support the central portion of the screen member 15 or 16 are radially formed on the inner wall surfaces of the expansion portions 63 and 73. It may be.

  The flow path regulating member 80 shown in FIG. 7 has a disk shape, and an opening hole 81 is formed at the center thereof. The outer diameter of the flow path regulating member 80 is set to be substantially equal to the inner diameter of the filling chamber 12 or 13 arranged. Further, the portion other than the opening hole 81 in the flow path regulating member 80 serves as a blocking wall that blocks the flow of gas between the filling chamber 12 or 13 and the connection passage 14. The structure allows the gas flow only from the hole 81. When such a flow path regulating member 80 is used, the first and second screen members 15, 15 are used in the same manner as when the flow path regulating members 20 and 22 shown in FIGS. 1 and 2 are used. Members corresponding to the perforated plates 41 and 42 for urging 16 toward the one end side of the first and second filling chambers 12 and 13 can be omitted.

The flow path regulating member 90 shown in FIG. 8 has a disk shape and is formed with a plurality of opening holes 91 as a whole, but the opening ratio of the central part is larger than the opening ratios of the other parts. It is set to be. That is, the flow path regulating member 90 is a central portion other than the part divided et al also has a structure in which the gas flow is acceptable, the central portion thereof, the larger amount of gas as compared with other portions The structure is easy to distribute. Here, the aperture ratio is the ratio of the aperture area per unit area. The outer diameter of the flow path regulating member 90 is set to be approximately equal to the inner diameter of the filling chamber 12 or 13 disposed.

  Since such a flow rate regulating member 90 allows gas to flow through the entire surface, the first flow rate regulating member 90 is compared with the flow path regulating members 20, 22, 50, 60, 70, 80 shown in FIGS. Although the gas flow in the second filling chambers 12 and 13 is less likely to be relatively uniform, the opening ratio of the central portion is larger than the opening ratio of the other portions, so that the first and second fillings are performed. The gas flow in the chambers 12 and 13 can be made relatively uniform to some extent. In the case where such a flow path regulating member 90 is used, the first and second screen members 15, 15, as in the case where the flow path regulating members 20 and 22 shown in FIGS. 1 and 2 are used. Members corresponding to the perforated plates 41 and 42 for urging 16 toward the one end side of the first and second filling chambers 12 and 13 can be omitted.

DESCRIPTION OF SYMBOLS 1 ... Canister 2 ... Casing 3 ... Main case 4 ... Cap 5 ... Purge port 6 ... Charge port 7 ... 1st cylindrical part 8 ... Atmospheric port 9 ... 2nd cylindrical part 11 ... Activated carbon 12 ... 1st filling chamber 13 ... Second filling chamber 14 ... Connection passage 15 ... First screen member 16 ... Second screen member 20 ... First flow path regulating member 22 ... Second flow path regulating member 23 ... First opening hole 24 ... Second opening hole 26 ... 1st base end part 27 ... 1st extension part 28 ... 1st protrusion wall 30 ... 2nd base end part 31 ... 2nd extension part 32 ... 2nd protrusion wall

Claims (1)

First and second filling chambers filled with an adsorbent for adsorbing and desorbing evaporated fuel are formed in parallel in the casing, and a charge port connected to a fuel tank is provided at one end of the first filling chamber. An evaporative fuel processing apparatus connected to a purge port connected to an intake system of the engine, and connected to an atmosphere port communicating with the atmosphere on one end side of the second filling chamber;
One end of the second filling chamber is located on a side of one end of the first filling chamber, and the other end of the second filling chamber is located on a side of the other end of the first filling chamber. The other end of the chamber communicates with the other end of the second filling chamber through a connection passage formed in the casing, and the connection passage communicates with the first filling chamber through a first screen member having air permeability. In addition, the second filling chamber communicates with the second screen member having air permeability, and reaches the one end side of the second filling chamber from the one end side of the first filling chamber to the connection passage in the casing. In the fuel vapor processing apparatus in which a U-shaped gas flow path is defined,
A first flow path regulating member that biases the first screen member toward one end of the first filling chamber;
A second flow path regulating member that urges the second screen member toward one end side of the second filling chamber,
The first flow path regulating member has a funnel shape, and has a first opening hole that allows gas flow in the center so that the gas flowing in the first filling chamber can easily flow in the center of the first filling chamber. A cylindrical first base end portion having one end and a tapered first extension portion that supports the outer peripheral edge of the first screen member over the entire circumference and has the other end continuous with the first base end portion. And the portion other than the first opening hole serves as a first blocking wall that blocks the flow of gas between the first filling chamber and the connection passage, and the gas flows only from the first opening hole. A plurality of first projecting walls that support the first screen member are radially formed on the inner wall surface of the first extension portion;
The second flow path regulating member has a funnel shape, and has a second opening hole that allows gas flow at the center so that the gas flowing through the second filling chamber can easily flow through the center of the second filling chamber. A cylindrical second base end portion having one end and a tapered second extension portion having one end supporting the outer peripheral edge of the second screen member over the entire circumference and the other end continuing to the second base end portion And the portion other than the second opening hole serves as a second blocking wall that blocks the flow of gas between the second filling chamber and the connection passage, and the gas flows only from the second opening hole. An evaporative fuel processing apparatus , wherein a flow is allowed, and a plurality of second projecting walls that support the second screen member are radially formed on an inner wall surface of the second extension portion .

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