JP2015048841A - Canister - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a value of ratio L/D, where L is defined as the length of adsorbent layer and D is defined as the effective section diameter D, without making a size of a casing into a large-sized one.SOLUTION: A drain side cartridge 50 mounted within the second chamber 30 has a first sub-chamber 52 and a second sub-chamber 53 communicated with each other in U-shape through an elliptical base part 57 and containing honeycomb active carbon 51 therein. The first sub-chamber 52 is formed with a communicating port 60 at a small-diameter part 52b, and the first sub-chamber 52 and an intermediate cartridge 70 are communicated with each other through the communicating port 60 and a flow passage 32. The second sub-chamber 53 is communicated with a drain port 18 through an upper end opening part 62. Evaporated fuel from the intermediate cartridge 70 flows through the flow passage 32 into the first sub-chamber 52 from the communicating port 60 and then is adsorbed into the active carbon 51, further flows through the second sub-chamber 53 and is adsorbed into the active carbon 51. Finally, air is discharged into surrounding atmosphere through the opening part 62 and the drain port 18.

Description

  The present invention relates to a canister, and more particularly to a canister that adsorbs fuel evaporated from a fuel tank of an automobile and burns the fuel when the engine is operating.

  In an automobile, a canister is used to prevent the evaporated fuel from a fuel system such as a fuel tank from being released into the atmosphere. Regulations regarding the emission of evaporated fuel to the atmosphere are strict, and in order to comply with this rule, it is necessary to reduce the emission of evaporated fuel to the atmosphere. It is known that increasing the value of the ratio L / D between the length L of the adsorbent layer and the effective cross-sectional diameter D is effective in reducing the amount of evaporated fuel released to the atmosphere. An example of a canister having a large L / D value is disclosed in Patent Document 1.

  In a canister according to Patent Document 1, a charge port connected to a fuel tank, a purge port connected to an intake manifold of an engine, and a drain port conducting to the atmosphere are provided in a casing. The interior of the casing is partitioned by a partition wall into a first chamber that communicates with the charge port and the purge port and a second chamber that communicates with the drain port, and the end of the first chamber and the second chamber The end portion of the casing is communicated by a communication passage, and a substantially U-shaped passage is formed in the casing. In the first chamber, the entire internal space is filled with activated carbon as an adsorbent, and in the second chamber, an adsorbent cartridge is loaded at the end on the drain port side, and the remaining space is filled with activated carbon. Yes. The adsorbent cartridge has a cross-section that is smaller than the cross-sectional area of the second chamber, and is filled with activated carbon. Thereby, a larger L / D value can be obtained.

Japanese Patent No. 4589422

  In recent years, environmental regulations have become stricter, and it has been required to further reduce the amount of evaporated fuel released into the atmosphere. Furthermore, it has become difficult to ensure the amount of purge air necessary for regeneration of activated carbon that has adsorbed fuel vapor due to hybridization of automobiles and the like.

  The canister disclosed in Patent Document 1 is configured such that an adsorbent cartridge filled with activated carbon in an adsorbent cartridge having a cross-sectional area smaller than the cross-sectional area of the second chamber is loaded into the second chamber. The ratio L / D of the layer length L and the effective sectional diameter D is increased, thereby reducing the amount of evaporated fuel released to the atmosphere. If the L / D is further increased for further improvement, the canister is increased in size.

  Therefore, there is a need for a canister that can suppress the diffusion of evaporated fuel to the atmosphere even with a low purge air amount without increasing the size of the canister.

The present invention has a casing in which a first chamber having a charge port and a purge port at one end and a second chamber having a drain port at one end are connected in a substantially U shape, and each chamber In the canister where the adsorbent is placed inside,
The second chamber is divided into a first region on the drain port side loaded with a drain side cartridge and a second region remaining in the longitudinal direction,
The drain-side cartridge has a first sub-chamber and a second sub-chamber arranged in parallel with each other, and these sub-chambers containing adsorbents form a substantially U-shaped flow path. It is characterized by being connected.

  In the above configuration, since the drain side cartridge provided in a partial region in the longitudinal direction of the second chamber forms a substantially U-shaped flow path, the length L of the adsorbent layer and the effective sectional diameter D The ratio L / D becomes larger.

  In one preferred embodiment, the drain port side end of the second sub-chamber communicates with the drain port, and the drain port side end of the first sub-chamber is connected to the drain side cartridge and the second port. This communicates with the second region through a gap between the side wall surface of the chamber.

  Preferably, a communication port is opened on a side surface of the drain port side end portion of the first sub-chamber.

  In such a configuration, for example, when the evaporated fuel is adsorbed, the evaporated fuel that has passed through the second region flows into the drain port side end portion of the first sub-chamber through the gap, and the second sub chamber Flows U-shaped into the chamber.

  In one preferred embodiment, an intermediate cartridge containing an adsorbent is loaded in the second region.

  In such a configuration, the value of the ratio L / D between the length L of the adsorbent layer and the effective sectional diameter D can be set as appropriate in both the drain side cartridge and the intermediate cartridge according to the required specifications. It becomes.

  According to the present invention, the value of the ratio L / D between the length L of the adsorbent layer and the effective cross-sectional diameter D can be further increased within a limited size, and without increasing the size of the canister, Emissions to the atmosphere can be effectively reduced.

1 is a longitudinal sectional view of a canister according to the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. The perspective view in the resin molded product single-piece | unit of a drain side cartridge. Similarly top view. Sectional drawing along line VV of FIG. The front view of a drain side cartridge. The side view of a drain side cartridge. The longitudinal cross-sectional view of a drain side cartridge. Explanatory drawing which shows the flow of the fuel vapor at the time of adsorption | suction. Explanatory drawing in the cross section along the surface orthogonal to the cross section of FIG. Explanatory drawing which shows the flow of the purge gas at the time of detachment | desorption. Explanatory drawing in the cross section along the surface orthogonal to the cross section of FIG. The longitudinal cross-sectional view of the 2nd Example of the canister of this invention. FIG. 14 is a cross-sectional view along a plane orthogonal to the cross section of FIG. 13. The longitudinal cross-sectional view of the 3rd Example of the canister of this invention. FIG. 14 is a cross-sectional view along a plane orthogonal to the cross section of FIG. 13.

  An embodiment of the canister 10 according to the present invention will be described in detail with reference to FIGS. In the following description, for ease of understanding, terms such as “up”, “down”, “left”, and “right” are used on the basis of the posture of FIG. The mounting posture is not limited to that shown in FIG.

  As shown in FIGS. 1 and 2, the canister 10 includes a casing 12 that is integrally formed of a synthetic resin material. The casing 12 includes a first chamber 20 having a charge port 14 connected to a fuel tank (not shown) and a purge port 16 connected to an engine intake portion (not shown) at the upper end, and a drain port 18 communicating with the atmosphere. A second chamber 30 provided at the upper end, and a communication path 40 communicating the lower end of the first chamber 20 and the lower end of the second chamber 30 with each other are provided. The first chamber 20, the communication passage 40, and the second chamber 30 form a substantially U-shaped passage inside the casing 12. The communication passage 40 is configured in a passage shape by attaching a separate cover 13 to the lower end opening of the casing 12.

  The first chamber 20 having a rectangular cross section is defined by an upper filter 22 disposed at each end on the charge port 14 and purge port 16 side and a lower filter 23 disposed on the end on the communication path 40 side. The first space portion 24 is provided. The lower filter 23 is supported by a perforated plate 25, and the perforated plate 25 is biased upward by a spring 27. The first space 24 is filled with granular activated carbon 29 as an adsorbent.

  The second chamber 30 having a rectangular cross section has a smaller cross section than the first chamber 20, and has a cross sectional area that is approximately one half of the cross sectional area of the first chamber 20. A drain-side cartridge 50 is loaded in an upper region (on the drain port 18 side) of the second chamber 30, and an intermediate cartridge 70 is loaded in a lower region (the communication path 40 side). A filter 36 supported by a porous plate 35 is disposed at the lower end of the intermediate cartridge 70, and the porous plate 35 is urged upward by a spring 37.

  The intermediate cartridge 70 is formed in a rectangular box shape from a synthetic resin material, and the filter 36 covers the opening at the lower end. A plurality of (for example, four) openings 76 are formed on the upper surface of the intermediate cartridge 70, and a plurality of protrusions projecting upward are provided in order to secure a predetermined distance from the drain side cartridge 50. A pier 72 is erected. Further, an O-ring 75 that seals between the intermediate cartridge 70 and the side wall surface 31 of the second chamber 30 is disposed on the outer peripheral surface of the lower end of the intermediate cartridge 70. A filter 78 made of urethane or the like is disposed at the upper end of the intermediate cartridge 70 so as to cover the opening 76. A granular activated carbon 71 is filled as an adsorbent in a space defined between the upper filter 78 and the lower filter 36.

  Next, the drain side cartridge 50 will be described in detail with reference to FIGS. In the drain-side cartridge 50, a cylindrical first sub-chamber 52 and a cylindrical second sub-chamber 53 that are arranged in parallel with each other are integrally formed of a synthetic resin material. At the upper ends of the first sub-chamber 52 and the second sub-chamber 53, there are an end wall 54 extending in the horizontal direction, and a first flange extending outward on the same plane as the end wall 54 55 and an oval mounting portion 56 projecting upward on the end wall 54 are provided.

  Lower ends of the first sub-chamber 52 and the second sub-chamber 53 are connected to an oval base 57, and a second flange 58 is provided at the lower end of the oval base 57. The bottom surface of the oval base 57 is open, and a separate cover 68 is welded to the bottom surface opening as shown in FIGS. As a result, the first sub-chamber 52 and the second sub-chamber 53 communicate with each other through the space in the oval base 57, and a passage that is substantially U-shaped is formed in the drain side cartridge 50. Is formed.

  As shown in FIGS. 3 and 5, the first sub-chamber 52 is located between the cylindrical main body 52a, the end wall 54 and the main body 52a, and has a smaller diameter than the main body 52a. Part 52b. The upper end of the first sub-chamber 52 is closed by the end wall 54. As shown in FIG. 5, a plurality of (for example, four) rectangular communication ports 60 arranged in the circumferential direction are formed in the side surface of the small diameter portion 52b. Similarly, the second sub-chamber 53 includes a cylindrical main body portion 53a, and a small-diameter portion 53b that is located between the end wall 54 and the main body portion 53a and has a smaller diameter than the main body portion 53a. The upper end of the second sub-chamber 53 is opened by two semicircular openings 62 provided in the end wall 54. Unlike the first sub-chamber 52, the small diameter portion 53b is not provided with a communication port 60.

  A packing 63 is mounted on the outer peripheral surface of the mounting portion 56 as a seal member (see FIGS. 6 to 8). As shown in FIGS. 1 and 2, a filter 64 a is loaded in the small diameter portion 52 b of the first sub-chamber 52 so as to cover the communication port 60. Similarly, the small diameter portion 53b of the second sub-chamber 53 is loaded with a filter 64b so as to cover the opening 62 of the second sub-chamber 53. The first sub-chamber 52 and the second sub-chamber 53 are loaded with the honeycomb activated carbon 51 formed into a columnar shape as an adsorbent together with the cylindrical packing 65 and the cylindrical cushioning material 66. Yes. A lower filter 67 is loaded in the oval base 57, and the lower end of the honeycomb activated carbon 51 is supported by the lower filter 67. Each of the filters 64a, 64b, 67 is made of a foamed material such as urethane.

  Next, a state where the drain side cartridge 50 and the intermediate cartridge 70 are loaded in the second chamber 30 will be described with reference to FIGS.

  The cross section of the second chamber 30 is reduced in a step shape at the upper end portion where the drain port 18 is formed. An cartridge support wall 80 having an oval shape is formed inside the upper end portion, and a shoulder portion 82 is formed at a transition portion having a step shape. The drain side cartridge 50 is positioned with the mounting portion 56 including the packing 63 inserted into the cartridge support wall 80 and the first flange 55 abutting against the shoulder portion 82. The peripheral edge of the second flange 58 at the bottom of the drain side cartridge 50 and the peripheral edge of the cover 68 are separated from the side wall surface 31 of the second chamber 30, and the periphery of the drain side cartridge 50 and the side wall surface 31 of the second chamber 30. There is a gap between them. This gap becomes the flow path 32 between the intermediate cartridge 70 and the drain side cartridge 50.

  Next, the flow of the evaporated fuel at the time of adsorption in the canister 10 will be described with reference to FIGS.

  The evaporated fuel generated from the fuel tank when the engine is stopped is introduced into the first chamber 20 via the charge port 14 and is adsorbed by the activated carbon 29. The evaporated fuel that has not been adsorbed by the activated carbon 29 further flows into the intermediate cartridge 70 via the communication path 40. At this time, since the space between the side wall surface 31 of the second chamber 30 is sealed by the O-ring 75 provided on the outer periphery of the intermediate cartridge 70, the evaporated fuel does not pass between them, and all the intermediate cartridge 70 flows into 70. The evaporated fuel that has flowed into the intermediate cartridge 70 is adsorbed by the activated carbon 71. The evaporated fuel that has not been adsorbed by the activated carbon 71 flows out of the intermediate cartridge 70 through the opening 76 provided on the upper surface of the intermediate cartridge 70. At this time, since the lower end of the drain-side cartridge 50 positioned above is sealed by the cover 68, the evaporated fuel that has flowed out of the intermediate cartridge 70 hits the cover 68 and flows forward, backward, left, and right as indicated by arrows. change.

  Thereafter, the evaporated fuel flows upward through the flow path 32 defined between the drain side cartridge 50 and the side wall surface 31 of the second chamber 30, and is provided in the small diameter portion 52 b of the first sub-chamber 52. The drain side cartridge 50, specifically, the first sub-chamber 52 flows through the communication port 60 formed. At this time, since the gap between the mounting portion 56 and the cartridge support wall 80 is sealed by the packing 63 mounted on the outer peripheral surface of the mounting portion 56, the evaporated fuel reliably passes through the communication port 60 and the drain side cartridge. 50 can flow into.

  The evaporated fuel flowing into the first sub chamber 52 is adsorbed by the honeycomb activated carbon 51 in the first sub chamber 52. Further, after passing through the lower filter 67, the direction is changed to flow into the second sub chamber 53 and flow upward, and is adsorbed by the honeycomb activated carbon 51 in the second sub chamber 53. Finally, the purified gas flows out of the second sub-chamber 53 through the filter 64b and the opening 62 provided at the upper end, and is discharged from the drain port 18 into the atmosphere.

  Next, the flow of air (purge gas) at the time of desorption in the canister 10 will be described with reference to FIGS. The flow of the purge gas at the time of desorption is basically a flow in the opposite direction to the flow at the time of adsorption as shown in the figure. Due to the negative pressure generated in the engine intake system, air is sucked from the drain port 18 and flows into the second sub-chamber 53 through the opening 62 and the filter 64b. The air flowing into the second sub-chamber 53 flows downward, passes through the lower filter 67, then flows into the first sub-chamber 52 and flows upward, and the communication port of the first sub-chamber 52 It flows out of the drain side cartridge 50 through 60. Next, air (purge gas) flows downward through a flow path 32 defined between the drain side cartridge 50 and the side wall surface 31 of the second chamber 30, and an opening provided on the upper surface of the intermediate cartridge 70. It flows into the intermediate cartridge 70 through the portion 76. Thereafter, the intermediate cartridge 70 flows into the first chamber 20 through the communication passage 40 and flows upward, and is sucked into the engine through the purge port 16.

  As described above, according to the above-described embodiment, the drain side cartridge 50 in which the U-shaped passage is formed by the first sub-chamber 52 and the second sub-chamber 53 is used as the cartridge loaded in the second chamber 30. Thus, the value of the ratio L / D between the length L of the adsorbent layer and the effective cross-sectional diameter D can be further increased within the limited dimensions of the casing 12. In particular, in the above embodiment, the gap between the drain side cartridge 50 and the side wall surface 31 is used as the flow path 32 so that the communication port 60 on the side surface of the drain side cartridge 50 and the intermediate cartridge 70 communicate with each other. The pair of honeycomb activated carbons 51 can be arranged using the space between the intermediate cartridge 70 and the drain port 18 more effectively.

  In each of the above embodiments, the drain side cartridge 50 is a filter having a large axial thickness in the small diameter portion 52b of the first sub chamber 52, the small diameter portion 53b of the second sub chamber 53, and the oval base portion 57. 64a, 64b, and 67, respectively, but these filters 64a, 64b, and 67 are not for preventing the adsorbent from flowing out in the present embodiment in which the adsorbent is the honeycomb activated carbon 51, but in the cross-sectional direction. Added for flow equalization. That is, the flow of the gas flowing in the U-turn shape in the drain side cartridge 50 is diffused in the cross-sectional direction by the filters 64a, 64b, and 67 so that the flow becomes more uniform.

  In the above embodiment, the O-ring 75 is used to seal between the outer peripheral surface of the lower end of the intermediate cartridge 70 and the side wall surface 31 of the second chamber 30, but the sealing member is limited to the O-ring. Alternatively, other sealing members such as a cylindrical packing may be used.

  As mentioned above, although one Example of this invention was described, this invention is not restricted to the said Example, A various change is possible.

  With reference to FIGS. 13 and 14, another embodiment of the present invention will be described. In this embodiment, as the adsorbent in the drain side cartridge 50, instead of the formed honeycomb activated carbon 51, granular activated carbon 151 having a large particle size is filled and used. The structure of the drain side cartridge 50 itself and the intermediate cartridge 70 are the same as those in the embodiment shown in FIGS.

  The granular activated carbon 151 having a large particle size includes a filter 64 a loaded in the small diameter portion 52 b of the first sub-chamber 52, a filter 64 b loaded in the small diameter portion 53 b of the second sub-chamber 53, and the oval base portion 57. Is filled in a space defined by the lower filter 67 loaded in the.

  Next, still another embodiment of the present invention will be described with reference to FIGS. In this embodiment, the lower part of the second chamber 30 is directly filled with granular activated carbon 271 instead of the intermediate cartridge 70. The drain side cartridge 50 is the same as the embodiment shown in FIGS.

  An intermediate filter 278 is disposed so as to contact the cover 68 of the drain side cartridge 50 loaded in the second chamber 30, and granular activated carbon 271 is placed in a space between the intermediate filter 278 and the lower filter 36. Is filled. The filter 36 is supported by a perforated plate 35, and the perforated plate 35 is biased upward by a spring 37.

  The activated carbons 29, 51, 71, 151, and 271 as adsorbents filled in the canister 10 can be properly used according to required specifications. For example, in some specifications, the first chamber 20, the intermediate cartridge 70, and the drain side cartridge 50 are all filled with high-performance activated carbon, and in other specifications, only the drain-side cartridge 50 is filled with high-performance activated carbon. It is possible to do.

  Further, the canister 10 of the present invention is not limited to the illustrated mounting posture. In the posture shown in FIGS. 1 and 2, the canister 10 is placed vertically so that the first sub-chamber 52 and the second sub-chamber 53 are aligned in parallel on the left and right. By mounting the canister 10 horizontally so that the second sub-chamber 53 is positioned below and the second sub-chamber 53 is positioned below, it is possible to obtain a delay effect of suppressing leakage due to the gravitational effect.

DESCRIPTION OF SYMBOLS 10 Canister 20 1st chamber 29,51,71 Activated carbon 30 2nd chamber 40 Communication path 50 Drain side cartridge 52 1st subchamber 53 2nd subchamber 57 Oval base 60 Communication port 70 Intermediate cartridge

Claims (4)

A first chamber having a charge port and a purge port at one end and a second chamber having a drain port at one end have a casing that is connected in a substantially U shape, and is adsorbed inside each chamber. In the canister where the material is placed,
The second chamber is divided into a first region on the drain port side loaded with a drain side cartridge and a second region remaining in the longitudinal direction,
The drain-side cartridge has a first sub-chamber and a second sub-chamber arranged in parallel with each other, and these sub-chambers containing adsorbents form a substantially U-shaped flow path. A canister characterized by being connected.   The drain port side end of the second sub-chamber communicates with the drain port, and the drain port side end of the first sub-chamber is connected to the drain side cartridge and the side wall surface of the second chamber. 2. The canister according to claim 1, wherein the canister communicates with the second region through a gap therebetween.   The canister according to claim 2, wherein a communication port is opened on a side surface of the drain port side end portion of the first sub-chamber.   The canister according to claim 1, wherein an intermediate cartridge containing an adsorbent is loaded in the second region.

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