Filtering canister

Abstract

The present disclosure provides a filter can capable of suppressing emission of evaporated fuel to the atmosphere. One aspect of the present disclosure relates to a filter can. The filter can includes a filling port; a purge port; an atmosphere port; a main chamber connected to the filling port and the purge port; a sub-chamber connected to the atmosphere port; an intermediate chamber disposed between the main chamber and the sub-chamber in a flow path of the evaporated fuel and connected to the main chamber and the sub-chamber, respectively; a first adsorbent housed in the main chamber; a second adsorbent housed in the sub-chamber; and a third adsorbent housed in the intermediate chamber. The adsorption capacity of the third adsorbent as a whole is less than the adsorption capacity of the first adsorbent as a whole and less than the adsorption capacity of the second adsorbent as a whole.

Description

Technical Field

[0001] This disclosure relates to filter tanks. Background Technology

[0002] A filter canister is installed in the vehicle's fuel tank to prevent evaporated fuel from being released into the atmosphere. The filter canister adsorbs evaporated fuel onto an adsorbent, and the intake air is used to desorb the fuel from the adsorbent for purging, and the desorbed evaporated fuel is then supplied to the engine.

[0003] A filter canister typically has at least a main chamber connected to a filling port and a secondary chamber connected to the main chamber. Adsorbent is contained in both the main and secondary chambers. If a large amount of evaporated fuel is supplied to the filter canister from the filling port, it is possible that unadsorbed evaporated fuel in the main and secondary chambers may be discharged through the atmosphere.

[0004] Therefore, it is known that a filter canister is equipped with a blow-through prevention unit to prevent the evaporation of fuel from the auxiliary chamber from being emitted into the atmosphere (see Japanese Patent Application Publication No. 2012-36734). Summary of the Invention

[0005] In the aforementioned filter canister, the anti-surge device is positioned adjacent to the atmospheric vent. Therefore, it is possible for evaporated fuel to be released into the atmosphere.

[0006] One aspect of this disclosure preferably provides a filter canister capable of suppressing the emission of evaporated fuel into the atmosphere.

[0007] One aspect of this disclosure relates to a filter canister that adsorbs and desorbs evaporating fuel generated in a vehicle's fuel tank. The filter canister comprises: a filling port for introducing evaporating fuel; a purging port for discharging evaporating fuel; an atmospheric port open to the atmosphere; a main chamber connected to both the filling port and the purging port; a secondary chamber directly connected to the atmospheric port, or connected to the atmospheric port via another chamber; an intermediate chamber disposed between the main chamber and the secondary chamber in the flow path of the evaporating fuel, and connected to both the main chamber and the secondary chamber; a first adsorbent housed in the main chamber; a second adsorbent housed in the secondary chamber; and a third adsorbent housed in the intermediate chamber. The overall adsorption capacity of the third adsorbent is less than that of the first adsorbent and less than that of the second adsorbent.

[0008] According to the structure described above, the intermediate chamber slows down the movement of unadsorbed evaporated fuel from the main chamber to the secondary chamber. Therefore, the emission of evaporated fuel into the atmosphere can be suppressed. Furthermore, the overall adsorption capacity of the third adsorbent in the intermediate chamber is less than that of the first adsorbent and also less than that of the second adsorbent, thus enabling miniaturization of the intermediate chamber. This further suppresses the emission of evaporated fuel into the atmosphere and prevents the filter canister from becoming too large.

[0009] In one embodiment of this disclosure, the ratio L [mm] of the length of the intermediate chamber in the gas flow direction to the equivalent diameter D [mm] of the cross-section of the intermediate chamber perpendicular to the gas flow direction, L / D, can be less than or equal to 1. According to the structure described above, the ventilation resistance of the intermediate chamber can be reduced. Furthermore, since the length of the intermediate chamber can be reduced, the effect of suppressing the enlargement of the filter canister can be promoted.

[0010] In one embodiment of this disclosure, the equivalent diameter of the cross-section of the intermediate chamber perpendicular to the gas flow direction can be less than or equal to the equivalent diameter of the cross-section of the secondary chamber perpendicular to the gas flow direction, and can be less than the equivalent diameter of the cross-section of the main chamber perpendicular to the gas flow direction. According to the structure described above, the desorption capacity of the third adsorbent in the intermediate chamber can be improved. Therefore, when the evaporated fuel is adsorbed again, the adsorption effect of the intermediate chamber is enhanced, thereby promoting the suppression of evaporated fuel emissions into the atmosphere.

[0011] In one embodiment of this disclosure, the filter canister may further include a flow path component and a spring. The flow path component is connected to the end of the main chamber located opposite the filling port, and the spring presses the flow path component toward the main chamber. An intermediate chamber may be disposed inside the flow path component. According to the structure described above, an intermediate chamber can be formed using a portion of the flow path structure. Therefore, it is possible to promote the suppression of filter canister enlargement.

[0012] In one embodiment of this disclosure, a connecting passage may be provided to connect the main chamber and the auxiliary chamber. An intermediate chamber may be disposed within the connecting passage. According to the structure described above, an intermediate chamber can be formed using a portion of the connecting passage. Therefore, it is possible to promote the suppression of large-scale filter tanks.

[0013] In one embodiment of this disclosure, the connecting passage may have a bend that turns the flow direction of the gas. An intermediate chamber may be disposed within the bend. According to the structure described above, the construction of the main chamber and the auxiliary chamber can be the same as in conventional constructions.

[0014] In one embodiment of this disclosure, the connecting passage may have a straight portion arranged in a straight line with the sub-chambers. The intermediate chamber may be disposed within the straight portion. According to the structure described above, the intermediate chamber is easily disposed and the third adsorbent is easily retained.

[0015] Furthermore, "the equivalent diameter of the cross-section perpendicular to the gas flow direction" refers to the diameter of a perfect circle with area S that is the same as the cross-section of each chamber perpendicular to the gas flow direction (D = (S / π)). 1 / 2 ×2) The average value in the direction of gas flow in each chamber. Attached Figure Description

[0016] Figure 1 This is a schematic cross-sectional view of the filter tank in the embodiment.

[0017] Figure 2A yes Figure 1 A schematic three-dimensional view of the flow path components in the filter tank.

[0018] Figure 2B yes Figure 2A A schematic cross-sectional view at the IIB-IIB line.

[0019] Figure 3A yes Figure 1 A schematic cross-sectional view at line IIIA-IIIA.

[0020] Figure 3B yes Figure 1 A schematic cross-sectional view at line IIIB-IIIB.

[0021] Figure 4 Is with Figure 1 Schematic cross-sectional view of filter tanks in different implementations.

[0022] Figure 5 Is with Figure 1 Schematic cross-sectional view of filter tanks in different implementations.

[0023] Figure 6 yes Figure 5 A schematic perspective view of the isolation pore grid in the filter tank. Detailed Implementation

[0024] The embodiments illustrated in this disclosure will now be described with reference to the accompanying drawings.

[0025] [1. First Embodiment]

[0026] [1-1. Structure]

[0027] Figure 1 The filter canister 1 shown adsorbs and desorbs evaporated fuel generated in the vehicle's fuel tank.

[0028] The filter tank 1 has a filling port 2A, a purging port 2B, an atmospheric port 2C, a main chamber 3, a secondary chamber 4, an intermediate chamber 5, a connecting passage 6, a first adsorbent 7, a second adsorbent 8, and a third adsorbent 9.

[0029] <port>

[0030] The filling port 2A is connected to the vehicle's fuel tank via a pipe. The filling port 2A is configured to guide the evaporated fuel generated in the fuel tank into the filter canister 1.

[0031] The purge port 2B is connected to the intake manifold of the vehicle's engine via a purge valve. The purge port 2B is configured to discharge evaporated fuel from the filter canister 1 and supply the evaporated fuel to the engine.

[0032] Atmospheric port 2C is connected to the vehicle's fuel inlet via a pipe and is open to the atmosphere. Atmospheric port 2C discharges the gas from which evaporated fuel has been removed into the atmosphere. In addition, atmospheric port 2C desorbs the evaporated fuel adsorbed in filter canister 1 by introducing outside air (i.e., purging air) (i.e., purging).

[0033] <Main Room>

[0034] The main chamber 3 contains the first adsorbent 7 and adsorbs the evaporated fuel introduced from the filling port 2A. In addition, the main chamber 3 discharges the adsorbed evaporated fuel from the purge port 2B.

[0035] The main chamber 3 is defined by a first filter 3A, a second filter 3B, and a third filter 3C disposed inside the housing 10 of the filter tank 1. The first filter 3A separates the filling port 2A connected to the main chamber 3 from the adsorbent storage space of the main chamber 3. The second filter 3B separates the purging port 2B connected to the main chamber 3 from the adsorbent storage space of the main chamber 3.

[0036] The third filter 3C separates the internal space of the main chamber 3, which is connected to the flow path component 11, from the adsorbent storage space of the main chamber 3. The first spring 12 presses the third filter 3C toward the filling port 2A and the purging port 2B via the flow path component 11.

[0037] The first filter 3A, the second filter 3B, and the third filter 3C are configured such that the first adsorbent 7 cannot pass through the first filter 3A, the second filter 3B, and the third filter 3C, while allowing the gas to pass through the first filter 3A, the second filter 3B, and the third filter 3C. That is, filters 3A, 3B, and 3C clamp the first adsorbent 7 within the main chamber 3.

[0038] <Deputy Office>

[0039] The secondary chamber 4 houses the second adsorbent 8. The secondary chamber 4 is connected to the main chamber 3 via the intermediate chamber 5 and the connecting passage 6, so that gas can flow freely between the secondary chamber 4 and the main chamber 3. The secondary chamber 4 is arranged in parallel to the main chamber 3 in the radial direction of the main chamber 3, such that the gas flow direction is parallel to the main chamber 3.

[0040] The sub-chamber 4 is defined by a first filter 4A and a second filter 4B disposed inside the housing 10 of the filter canister 1. The first filter 4A separates the atmospheric port 2C connected to the sub-chamber 4 from the adsorbent storage space of the sub-chamber 4. The second filter 4B separates the connecting passage 6 from the adsorbent storage space of the sub-chamber 4.

[0041] The second spring 14 presses the second filter 4B toward the atmospheric opening 2C via a resin-made grid-like perforated element 13. The first filter 4A and the second filter 4B, which define the sub-chamber 4, have the same function as the filters 3A, 3B, and 3C in the main chamber 3.

[0042] <Intermediate Room>

[0043] The intermediate chamber 5 houses the third adsorbent 9, and the intermediate chamber 5 is positioned between the main chamber 3 and the auxiliary chamber 4 in the flow path of the evaporated fuel.

[0044] The intermediate chamber 5 is defined by a first filter 5A and a second filter 5B disposed inside a resin-made flow path component 11, wherein the flow path component 11 is connected to the end of the main chamber 3 located opposite to the filling port 2A (i.e., the third filter 3C). That is, the intermediate chamber 5 is disposed inside the flow path component 11. Figure 2A as well as Figure 2B As shown, the flow path component 11 has a tapered portion 11A and a cylindrical portion 11B.

[0045] The conical portion 11A is a part having an internal space 11C that tapers towards the side opposite to the main chamber 3. The first spring 12 presses the conical portion 11A towards the third filter 3C (see reference). Figure 1 That is, the first spring 12 presses the flow path component 11 toward the main chamber 3.

[0046] The internal space 11C of the conical portion 11A is provided with ribs 11D. Ribs 11D are formed in a grid shape to allow the vaporized fuel F to pass through. Ribs 11D support the first filter 5A.

[0047] The cylindrical section 11B is connected to the opposite end of the conical section 11A located in the main chamber 3. The cylindrical section 11B is a tube with a circular cross-section. A portion of the internal space of the cylindrical section 11B forms the intermediate chamber 5.

[0048] The first filter 5A separates the internal space 11C of the conical section 11A from the adsorbent storage space of the intermediate chamber 5. The second filter 5B separates the connecting passage 6 from the adsorbent storage space of the intermediate chamber 5.

[0049] The first filter 5A and the second filter 5B are respectively disposed inside the cylindrical portion 11B. In addition, the third spring 16 presses the second filter 5B toward the main chamber 3 via the lattice-shaped hole member 15 made of resin. The first filter 5A and the second filter 5B that define the intermediate chamber 5 have the same functions as the filters 3A, 3B, and 3C in the main chamber 3.

[0050] The intermediate chamber 5 is connected to the main chamber 3 via the internal space 11C of the tapered portion 11A. In addition, the intermediate chamber 5 is connected to the auxiliary chamber 4 via the space forming the communication path 6. That is, there are buffer spaces where no adsorbent is disposed between the intermediate chamber 5 and the main chamber 3, and between the intermediate chamber 5 and the auxiliary chamber 4. Through this buffer space, the emission of the evaporated fuel to the atmosphere can be delayed.

[0051] <Communication path>

[0052] The communication path 6 is a space that connects the intermediate chamber 5 and the auxiliary chamber 4. The auxiliary chamber 4 is connected to the main chamber 3 via the intermediate chamber 5 and the communication path 6. The flow path connecting the main chamber 3 and the auxiliary chamber 4 is only the flow path formed by the intermediate chamber 5 and the communication path 6.

[0053] The evaporated fuel inhaled from the filling port 2A is adsorbed by the first adsorbent 7 in the main chamber 3. The evaporated fuel not completely adsorbed in the main chamber 3 moves to the intermediate chamber 5 through the tapered portion 11A of the flow path component 11, and is adsorbed by the third adsorbent 9 in the intermediate chamber 5.

[0054] In addition, the evaporated fuel not completely adsorbed in the intermediate chamber 5 moves to the auxiliary chamber 4 through the communication path 6, and is adsorbed by the second adsorbent 8 in the auxiliary chamber 4. The gas in which the evaporated fuel has been adsorbed is discharged from the air vent 2C.

[0055] In addition, by supplying gas from the air vent 2C, the evaporated fuel adsorbed by the adsorbent in each of the auxiliary chamber 4, the intermediate chamber 5, and the main chamber 3 is discharged from the purge port 2B into the engine. Thus, the air containing the evaporated fuel is supplied to the engine.

[0056] <Dimensions of each chamber>

[0057] As Figure 1 shown, the relationship between the length L1 of the main chamber 3 in the gas flow direction, the length L2 of the auxiliary chamber 4 in the gas flow direction, and the length L3 of the intermediate chamber 5 in the gas flow direction is as shown in the following formula (1).

[0058] L2 > L3 and L1 > L3... Formula (1)

[0059] That is, the length L3 of the intermediate chamber 5 is less than the length L2 of the auxiliary chamber 4 and less than the length L1 of the main chamber 3. In addition, in the present embodiment, L2 < L1, however, it may also be L2 ≥ L1.

[0060] In addition, as Figure 3A and Figure 3B shown, the relationship between the equivalent diameter D1 of the cross-section of the main chamber 3 perpendicular to the gas flow direction, the equivalent diameter D2 of the cross-section of the auxiliary chamber 4 perpendicular to the gas flow direction, and the equivalent diameter D3 of the cross-section of the intermediate chamber 5 perpendicular to the gas flow direction is as shown in the following formula (2).

[0061] D2 ≥ D3 and D1 > D3... Formula (2)

[0062] That is, the equivalent diameter D3 of the intermediate chamber 5 is less than or equal to the equivalent diameter D2 of the auxiliary chamber 4 and less than the equivalent diameter D1 of the main chamber 3. In addition, in this embodiment, D2 < D1, however, it may also be D2 ≥ D1.

[0063] The ratio L3 / D3 of the length L3 [mm] of the intermediate chamber 5 to the equivalent diameter D3 [mm] is less than or equal to 1. On the other hand, the ratio L2 / D2 of the length L2 [mm] of the auxiliary chamber 4 to the equivalent diameter D2 [mm] and the ratio L1 / D1 of the length L1 [mm] of the main chamber 3 to the equivalent diameter D1 [mm] are both greater than 1.

[0064] <Adsorbent>

[0065] The first adsorbent 7, the second adsorbent 8, and the third adsorbent 9 each adsorb the evaporated fuel and / or butane supplied to the filter tank 1 together with air or the like. And the evaporated fuel and / or butane are desorbed by introducing external air. The desorbed evaporated fuel is supplied to the engine.

[0066] As raw materials for the first adsorbent 7, the second adsorbent 8, and the third adsorbent 9, known raw materials such as activated carbon can be used. As the activated carbon, for example, an aggregate of granular activated carbon, formed activated carbon formed into a honeycomb shape, etc., activated carbon obtained by forming fibrous activated carbon into a sheet shape, a cuboid shape, a cylindrical shape, a prismatic shape, etc. can be used.

[0067] The overall adsorption capacity of the third adsorbent 9 housed in the intermediate chamber 5 is less than the overall adsorption capacity of the first adsorbent 7 housed in the main chamber 3 and less than the overall adsorption capacity of the second adsorbent 8 housed in the auxiliary chamber 4.

[0068] The "overall adsorption capacity of the adsorbent" described here refers to the value obtained by multiplying the amount of evaporated fuel that can be adsorbed per unit volume of the adsorbent by the volume of the adsorbent housed in each chamber. Therefore, the overall adsorption capacity of the adsorbent in each chamber can be adjusted by changing the adsorbent in each chamber to an adsorbent with different adsorption amounts per unit volume, and / or by changing the volume of the adsorbent housed in each chamber.

[0069] Therefore, the first adsorbent 7, the second adsorbent 8, and the third adsorbent 9 can be of the same type or different types of adsorbents.

[0070] The intermediate chamber 5 must be in a state free of adsorbed evaporated fuel after purging. Therefore, if the adsorption capacity of the intermediate chamber 5 is too high, evaporated fuel will remain after purging, affecting subsequent adsorption performance. Furthermore, from the viewpoint of miniaturizing the filter tank 1, the intermediate chamber 5 also needs to be miniaturized. Based on these considerations, the adsorption capacity of the intermediate chamber 5 is set to be lower than that of the main chamber 3. Moreover, by setting the adsorption capacity of the intermediate chamber 5 to be relatively low, the desorption of evaporated fuel from the adsorbent is improved.

[0071] [1-2. Effects]

[0072] The following effects can be obtained by implementing the methods described in detail above.

[0073] (1a) The intermediate chamber 5 slows down the movement of unadsorbed evaporated fuel from the main chamber 3 to the secondary chamber 4. Therefore, the emission of evaporated fuel into the atmosphere can be suppressed. Furthermore, the overall adsorption capacity of the third adsorbent 9 in the intermediate chamber 5 is less than that of the first adsorbent 7 and less than that of the second adsorbent 8; therefore, the intermediate chamber 5 can be miniaturized. This further suppresses the emission of evaporated fuel into the atmosphere and prevents the filter canister 1 from becoming too large.

[0074] (1b) The L3 / D3 ratio of the intermediate chamber 5 is less than or equal to 1, thereby reducing the ventilation resistance of the intermediate chamber 5. In addition, since the length of the intermediate chamber 5 can be reduced, it can promote the effect of suppressing the enlargement of the filter tank 1.

[0075] (1c) The equivalent diameter D3 of the intermediate chamber 5 is less than or equal to the equivalent diameter D2 of the secondary chamber 4, and less than the equivalent diameter D1 of the main chamber 3. This improves the desorption capacity of the third adsorbent 9 in the intermediate chamber 5. Therefore, when the evaporated fuel is adsorbed again, the adsorption effect of the intermediate chamber 5 is improved, thereby promoting the suppression of the emission of evaporated fuel into the atmosphere.

[0076] (1d) The intermediate chamber 5 is disposed inside the flow path component 11, thereby enabling the intermediate chamber 5 to be formed using a portion of the flow path structure. Therefore, it is possible to promote the effect of suppressing the enlargement of the filter tank 1.

[0077] [2. Second Implementation]

[0078] [2-1. Structure]

[0079] Figure 4The filter canister 101 shown adsorbs and desorbs evaporated fuel generated in the fuel tank. The filter canister 101 includes a filling port 2A, a purging port 2B, an atmospheric port 2C, a main chamber 3, a secondary chamber 4, an intermediate chamber 105, a connecting passage 106, a first adsorbent 7, a second adsorbent 8, and a third adsorbent 9.

[0080] The filter tank 101 includes a filling port 2A, a purging port 2B, an atmospheric port 2C, a main chamber 3, a secondary chamber 4, and adsorbents 7, 8, and 9. Figure 1 The corresponding structure in filter tank 1 is the same, therefore the same symbol is used and the description is omitted. Furthermore, in this embodiment, instead of... Figure 1 Instead of the flow path component 11, a third filter 3C separates the main chamber 3 by pressing a grid-like perforated element 111 made of resin.

[0081] <Intermediate Room>

[0082] The intermediate chamber 105 is disposed between the main chamber 3 and the auxiliary chamber 4 in the flow path of the evaporated fuel, and is connected to the main chamber 3 and the auxiliary chamber 4 respectively via space.

[0083] The intermediate chamber 105 is disposed within the bend 106A of the connecting passage 106. Specifically, the intermediate chamber 105 is separated by a first filter 105A and a second filter 105B disposed in the middle portion of the bend 106A.

[0084] The first filter 105A separates the area near the main chamber 3 of the connecting passage 106 from the adsorbent storage space of the intermediate chamber 105. The second filter 105B separates the area near the secondary chamber 4 of the connecting passage 106 from the adsorbent storage space of the intermediate chamber 105.

[0085] The third spring 116 presses the first filter 105A against the second filter 105B via a resin-made grid-like perforated member 115. The second filter 105B is supported by the inner wall of the bend 106A that forms the connecting path 106.

[0086] The intermediate chamber 105 contains the same third adsorbent 9 as in the first embodiment. The relationship between the length and equivalent diameter of the intermediate chamber 105 and the length and equivalent diameter of the main chamber 3 and the sub-chamber 4 is the same as in the first embodiment.

[0087] <Connecting path>

[0088] The connecting passage 106 is a space that connects the main chamber 3 and the secondary chamber 4. The connecting passage 106 has an S-shaped bend 106A.

[0089] At the bend 106A, the flow direction of the gas that has passed through the main chamber 3 is radial (i.e., Figure 4The vertical direction) turns to a direction parallel to the gas flow direction in the main chamber 3 (i.e., the vertical direction) Figure 4 After turning left and right, it then turns radially to the main chamber 3.

[0090] As described above, the intermediate chamber 105 is disposed in the middle portion of the crank section 106A, which is the portion of the crank section 106A in which the gas flow direction is parallel to the gas flow direction of the main chamber 3. The middle portion of the crank section 106A (i.e., the intermediate chamber 105) is disposed radially between the main chamber 3 and the auxiliary chamber 4.

[0091] [2-2. Effect]

[0092] The following effects can be obtained by implementing the methods described in detail above.

[0093] (2a) An intermediate chamber 105 can be formed using a portion of the connecting passage 106. Therefore, it is possible to promote the effect of suppressing the enlargement of the filter tank 101. Furthermore, by providing the intermediate chamber 105 at the bend 106A of the connecting passage 106, the structure of the main chamber 3 and the auxiliary chamber 4 can be the same as the conventional structure.

[0094] [3. Third Implementation]

[0095] [3-1. Structure]

[0096] Figure 5 The filter canister 201 shown adsorbs and desorbs evaporated fuel generated in the fuel tank. The filter canister 201 includes a filling port 2A, a purging port 2B, an atmospheric port 2C, a main chamber 3, a secondary chamber 4, an intermediate chamber 205, a connecting passage 206, a first adsorbent 7, a second adsorbent 8, and a third adsorbent 9.

[0097] The filter tank 201 includes a filling port 2A, a purging port 2B, an atmospheric port 2C, a main chamber 3, a secondary chamber 4, and adsorbents 7, 8, and 9. Figure 4 The filter tank 101 is the same, so it is marked with the same symbol and the description is omitted.

[0098] <Intermediate Room>

[0099] The intermediate chamber 205 is disposed between the main chamber 3 and the auxiliary chamber 4 in the flow path of the evaporated fuel, and is connected to the main chamber 3 and the auxiliary chamber 4 respectively via space.

[0100] The intermediate chamber 205 is disposed within the straight section 206A of the connecting passage 206. Specifically, the intermediate chamber 205 is defined by the first filter 205A and the second filter 205B disposed within the straight section 206A.

[0101] The first filter 205A separates the area near the main chamber 3 in the straight section 206A from the adsorbent storage space in the intermediate chamber 205. The second filter 205B separates the area near the secondary chamber 4 in the straight section 206A from the adsorbent storage space in the intermediate chamber 205.

[0102] The third spring 216 presses the first filter 205A toward the sub-chamber 4 via a resin-made grid-like perforated element 215. In this embodiment, the third spring 216 also serves as a spring for pressing the second filter 4B that defines the sub-chamber 4 (i.e., Figure 4 The second spring (14) in the middle.

[0103] The second filter 205B is pressed by a resin-made isolation pore grid 213 disposed between the secondary chamber 4 and the intermediate chamber 205. Figure 6 As shown, the isolation hole grid 213 has a three-dimensional grid shape.

[0104] The isolation grid 213 allows the evaporated fuel to pass through it in the same direction as the gas flow in the sub-chamber 4. The isolation grid 213 creates a buffer space without adsorbent between the sub-chamber 4 and the intermediate chamber 205. This buffer space slows down the emission of the evaporated fuel into the atmosphere.

[0105] like Figure 5 As shown, the third adsorbent 9, the same as in the first embodiment, is disposed in the intermediate chamber 205. The relationship between the length and equivalent diameter of the intermediate chamber 205 and the length and equivalent diameter of the main chamber 3 and the sub-chamber 4 is the same as in the first embodiment.

[0106] <Connecting path>

[0107] The connecting passage 206 is a space that connects the main chamber 3 and the auxiliary chamber 4. The connecting passage 206 has a straight section 206A, which is arranged in a straight line with the auxiliary chamber 4 on the opposite side of the atmospheric opening 2C of the auxiliary chamber 4.

[0108] The gas flow direction in the straight section 206A is parallel to the gas flow direction in the sub-chamber 4. Furthermore, the gas flow direction in the straight section 206A within the sub-chamber 4 (i.e.,...) Figure 5 It overlaps with the secondary chamber 4 in the left-right direction. As described above, an intermediate chamber 205 and an isolation hole grid 213 are arranged in the straight section 206A. The intermediate chamber 205 is arranged offset from the main chamber 3 in the radial direction.

[0109] [3-2. Effect]

[0110] The following effects can be obtained by implementing the methods described in detail above.

[0111] (3a) An intermediate chamber 205 can be formed using a portion of the connecting passage 206. Therefore, it is possible to promote the effect of suppressing the enlargement of the filter tank 201. Furthermore, by providing the intermediate chamber 205 in the straight portion 206A of the connecting passage 206, it is easy to configure the intermediate chamber 205 and easy to retain the third adsorbent 9.

[0112] [4. Other Implementation Methods]

[0113] The embodiments of this disclosure have been described above; however, this disclosure is not limited to the above embodiments and can be implemented in various ways.

[0114] (4a) In the filter tank of the above embodiment, an auxiliary chamber for containing adsorbent may also be provided between the sub-chamber and the atmospheric port. That is, the atmospheric port may also be connected to the sub-chamber via another chamber (i.e., the auxiliary chamber).

[0115] (4b) The function of one constituent element in the above embodiments can be distributed among multiple constituent elements, or the functions of multiple constituent elements can be integrated into one constituent element. Furthermore, a portion of the structure of the above embodiments can be omitted. At least a portion of the structure of one embodiment can be added to the structure of other embodiments, or at least a portion of the structure of one embodiment can be substituted with the structure of other embodiments. Additionally, all forms encompassed by the technical concept defined by the statements in the claims are embodiments of this disclosure.

Claims

1. A filter canister for adsorbing and desorbing evaporated fuel generated in a vehicle's fuel tank, characterized in that, have: A filling port through which the evaporated fuel is introduced; A purge port, through which the evaporated fuel is discharged; An atmospheric vent, which opens to the atmosphere; The main chamber is connected to the filling port and the purge port; A secondary chamber, which is directly connected to the atmospheric port or connected to the atmospheric port via another chamber; An intermediate chamber is disposed between the main chamber and the auxiliary chamber in the flow path of the evaporated fuel, and the intermediate chamber is connected to both the main chamber and the auxiliary chamber. The first adsorbent is housed in the main chamber; A second adsorbent, wherein the second adsorbent is contained in the sub-chamber; as well as The third adsorbent, which is housed in the intermediate chamber, and The overall adsorption capacity of the third adsorbent is less than that of the first adsorbent and also less than that of the second adsorbent. The filter can also include flow path components and springs. The flow path component is connected to the end of the main chamber located on the opposite side of the filling port. The spring presses the flow path component toward the main chamber. The intermediate chamber is disposed inside the flow path component.

2. The filter tank according to claim 1, characterized in that, The ratio L / D of the length L of the intermediate chamber in the gas flow direction to the equivalent diameter D of the cross section of the intermediate chamber perpendicular to the gas flow direction is less than or equal to 1.

3. The filter tank according to claim 1, characterized in that, The equivalent diameter of the cross section of the intermediate chamber perpendicular to the gas flow direction is less than or equal to the equivalent diameter of the cross section of the secondary chamber perpendicular to the gas flow direction, and less than the equivalent diameter of the cross section of the main chamber perpendicular to the gas flow direction.

4. The filter tank according to claim 1, characterized in that, It also has a connecting path that connects the main chamber and the auxiliary chamber. The intermediate chamber is located within the connecting passage.

5. The filter tank according to claim 4, characterized in that, The connecting path has a bend that turns the direction of gas flow. The intermediate chamber is located within the crank section.

6. The filter tank according to claim 4, characterized in that, The connecting passage has a straight section arranged in a straight line with the sub-chamber. The intermediate chamber is located within the straight section.

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