Filtering tank

Abstract

The present disclosure provides a canister. The canister is provided with a plurality of chambers, a housing member, an inflow port, an atmosphere port, and an outflow port. An adsorbent for adsorbing fuel vapor is disposed in the plurality of chambers. The housing member forms a main chamber that is one of the plurality of chambers. The inflow port and the outflow port are provided at a first end portion of the main chamber. The housing member has at least one narrowed portion that is a wall-like portion that forms a region around the first end portion in the main chamber. The at least one narrowing portion is configured so that the area of a cross-section orthogonal to the flow direction of the fluid in the main chamber is narrowed toward the first end portion.

Description

Technical Field

[0001] The present disclosure relates to filter canisters. Background Art

[0002] As described in Japanese Patent Publication No. 2013-11249, a filter canister is known, wherein a first adsorption chamber adjacent to an atmospheric port, a second adsorption chamber, and a space chamber located between the first adsorption chamber and the second adsorption chamber are arranged in a row, wherein the atmospheric port is used to allow atmospheric air to flow into the filter canister during purging. In the filter canister, when the purging air passes through the space chamber, its flow rate is reduced, thereby lengthening the contact time between the adsorbent in the second adsorption chamber and the purging air. Thus, the desorption efficiency of the fuel vapor can be improved. Summary of the invention

[0003] However, the main chamber is provided with a filling port connected to the fuel tank and a purge port for discharging fuel vapor during purging, and its volume is large. Therefore, the flow rate of the purge air is reduced due to the space, resulting in the possibility that the flow of the air may stagnate in the main chamber.

[0004] In one aspect of the present disclosure, it is desirable to facilitate smooth flow of fluid in a filter tank.

[0005] One scheme of the present disclosure is a canister configured to be installed in a vehicle having an engine, the canister having a plurality of chambers, a shell member, an inlet, an atmospheric port, and an outlet. An adsorbent for adsorbing fuel vapor is arranged in the chamber. The shell member forms a main chamber as one of the plurality of chambers. The inlet is a portion arranged at the first end of the main chamber, and the inlet is configured to allow fuel vapor to flow from a fuel tank of the vehicle into the main chamber. The atmospheric port is configured to be open to the atmosphere, and the atmospheric port is configured to be arranged in a sub-chamber as one of the plurality of chambers. The outlet is a portion arranged at the first end of the main chamber, and the outlet is configured to allow fuel vapor adsorbed in the adsorbent to flow toward the engine through the atmosphere flowing from the atmospheric port. The shell member has at least one reduction portion, and at least one reduction portion is a wall-shaped portion that forms an area around the first end in the main chamber. At least one reduction portion is configured so that the area of ​​a cross section orthogonal to the flow direction of the fluid in the main chamber decreases as it approaches the first end.

[0006] According to the above configuration, the flow of the fluid around the first end portion in the main chamber can be improved by at least one narrowing portion, thereby promoting smooth flow of the fluid in the canister.

[0007] In one embodiment of the present disclosure, at least one narrowing portion is a wall-shaped portion forming a peripheral area of ​​the first end portion of the main chamber where the inlet is provided, and at least one narrowing portion can be constructed so that the cross-section of the area decreases as it approaches the inlet.

[0008] According to the above configuration, the flow of the fluid in the area around the inlet in the main chamber can be improved by at least one narrowing portion, thereby promoting smooth flow of the fluid in the canister.

[0009] In one embodiment of the present disclosure, at least one narrowing portion is a wall-shaped portion forming a peripheral area of ​​the first end portion of the main chamber where the outflow port is provided, and at least one narrowing portion can be constructed so that the cross-section of the area decreases as it approaches the outflow port.

[0010] According to the above configuration, at least one narrowing portion can improve the flow of fluid in the area around the outflow port in the main chamber, thereby facilitating the fuel vapor accumulated in the canister to smoothly flow out from the outflow port during purging, thereby improving desorption performance.

[0011] In one embodiment of the present disclosure, a plurality of reduction portions may be provided as at least one reduction portion. One of the plurality of reduction portions is a wall-shaped portion that forms a peripheral region of a first end portion of the main chamber where an inlet is provided, and one of the plurality of reduction portions may be configured such that a cross section of the region decreases as it approaches the inlet. One of the plurality of reduction portions is a wall-shaped portion that forms a peripheral region of a first end portion of the main chamber where an outlet is provided, and one of the plurality of reduction portions may be configured such that a cross section of the region decreases as it approaches the outlet.

[0012] According to the above configuration, the flow of the fluid in the area around the inlet and the area around the outlet in the main chamber can be improved. Therefore, the fluid can flow smoothly in the filter tank. In addition, the fuel vapor accumulated in the filter tank can be facilitated to flow out smoothly from the outlet when purging, thereby improving the desorption performance.

[0013] In one aspect of the present disclosure, at least one narrowing portion has a portion inclined with respect to the flow direction, and the portion may surround a region around the first end portion in the main chamber.

[0014] According to the above configuration, the flow of the fluid around the first end portion in the main chamber can be further improved by at least one narrowing portion, thereby promoting a smoother flow of the fluid in the canister.

[0015] In one embodiment of the present disclosure, at least one narrowing portion may extend in a straight line on an axial cross section, wherein the axis is a line passing through the first end portion where the at least one narrowing portion is provided and is a line extending along the flow direction, and the axial cross section is a cross section including the axis.

[0016] According to the above configuration, the flow of the fluid around the first end portion in the main chamber can be improved by at least one narrowing portion, thereby promoting smooth flow of the fluid in the canister.

[0017] In one aspect of the present disclosure, at least one constriction may be tapered.

[0018] According to the above configuration, the flow of the fluid around the first end portion in the main chamber can be improved by at least one narrowing portion, thereby promoting smooth flow of the fluid in the canister.

[0019] In one aspect of the present disclosure, a granular adsorbent may be disposed in the main chamber. At least one gap-forming portion may be provided near an inner peripheral surface of at least one narrowing portion, and the at least one gap-forming portion may have a predetermined shape.

[0020] According to the above configuration, a gap is easily formed between the gap forming portion and the granular adsorbent located around the gap forming portion, so that the ventilation resistance inside the at least one constricted portion can be reduced.

[0021] In one aspect of the present disclosure, the at least one gap forming portion may be a plate-shaped portion protruding from an inner peripheral surface of the at least one narrowing portion.

[0022] According to the above configuration, a gap is easily formed between the gap forming portion and the granular adsorbent located around the gap forming portion, so that the ventilation resistance inside the at least one constricted portion can be reduced.

[0023] In one embodiment of the present disclosure, at least one gap forming portion is a plurality of plate-shaped portions protruding from the inner circumferential surface of at least one reduction portion, and at least one gap forming portion can be arranged at approximately fixed intervals around an axis, and the axis can be a line extending along the flow direction and passing through an inlet or an outlet.

[0024] According to the above configuration, a gap is easily formed between the gap forming portion and the granular adsorbent located around the gap forming portion, so that the ventilation resistance inside the at least one constricted portion can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view of the filter tank along the flow direction of the fluid.

[0026] Figure 2 It is a cross-sectional view of the reduced portion of Modification 1 along the flow direction of the fluid.

[0027] Figure 3 It is a cross-sectional view of the reduced portion of Modification 1 along the flow direction of the fluid.

[0028] Figure 4It is a cross-sectional view of the reduced portion of Modification Example 2 along the flow direction of the fluid.

[0029] Figure 5 It is a cross-sectional stereoscopic view of the reduced portion of Modification Example 3 along the flow direction of the fluid. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0031] The embodiments of the present disclosure are not limited to the following embodiments, and can be implemented in various forms within the technical scope to which the present disclosure belongs.

[0032] [(1) Structure of filter tank]

[0033] The canister 1 of this embodiment is mounted on a vehicle (see Figure 1 The canister 1 has an outer shell 10 made of resin forming the outer peripheral surface of the canister 1, and a main chamber 20 and a sub-chamber 30 are provided inside the outer shell 10. An adsorbent 4 for adsorbing fuel vapor is arranged in the above chambers. In addition, the number of chambers in the canister 1 can be, for example, three or more.

[0034] The adsorbent 4 may be, for example, granular or powdered activated carbon, or fibrous activated carbon aggregates or honeycomb carbon containing activated carbon. The adsorbent 4 is not limited to activated carbon, and may be composed of various materials capable of adsorbing fuel vapor.

[0035] An inlet 11, an outlet 12, and an air port 13 are provided at the end of the outer shell 10. Hereinafter, the side of the outer shell 10 of the filter tank 1 on which the inlet 11, the outlet 12, and the air port 13 are provided is referred to as the port side. In addition, the outer shell 10 has an opening on the side opposite to the port side. The opening is closed by a cover member 14. Hereinafter, the side opposite to the port side (in other words, the side on which the cover member 14 is provided) is referred to as the cover side.

[0036] [2.Main chamber]

[0037] The main chamber 20 forms a substantially rectangular parallelepiped space extending from the port side to the cover side, and an inlet 11 and an outlet 12 are provided at an end portion on the port side (hereinafter referred to as a first end portion F), and the inlet 11 and the outlet 12 allow the main chamber 20 to communicate with the outside of the filter tank 1 (see Figure 1). In addition, the shape of the space in the main chamber 20 is not limited to a roughly rectangular parallelepiped shape, and may be, for example, a roughly cylindrical shape. In addition, the end portion of the cover side of the main chamber 20 (hereinafter referred to as the second end portion S) is connected to the connecting passage 15. In the main chamber 20, fuel vapor and the purge air (hereinafter also referred to as fluid) described later flow in directions in which the first end portion F and the second end portion S are opposite to each other. The main chamber 20 is formed by the shell member 10 and includes a main body 21 and two reduction portions 22.

[0038] The main body portion 21 extends from the second end portion S of the main chamber 20 toward the port side and is a wall-shaped portion surrounding the main chamber 20 from the side surface.

[0039] The two reduction portions 22 extend from the end of the main body 21 on the port side toward the port side, and are wall-shaped portions that form the main chamber 20. Each reduction portion 22 is configured so that the area of ​​a cross section orthogonal to the flow direction of the fluid in the main chamber 20 (hereinafter referred to as an orthogonal cross section) decreases as it approaches the port side (in other words, the first end F side). The two reduction portions 22 are provided corresponding to the area around the inlet 11 and the area around the outlet 12, respectively, and the two reduction portions 22 surround the area around the corresponding port in the main chamber 20 from the side, so that the orthogonal cross section of the area decreases as it approaches the corresponding port.

[0040] In addition, the two reduction portions 22 are arranged in a direction perpendicular to the flow direction of the fluid at the end portion of the main body 21 located on the port side, more specifically, along the arrangement direction of the main chamber 20 and the sub-chamber 30. The first end F of the main chamber 20 is composed of the ends located on the port side of the two reduction portions 22. The inlet 11 and the outlet 12 are respectively provided at the end of each reduction portion 22 (in other words, at each first end F).

[0041] A filter 23 is provided at each first end F of the main chamber 20, and a filter 24 is provided at the second end S. Furthermore, an adsorbent 4 is arranged between the two filters 21 located on the port side and the filter 24 located on the cover side. In addition, a permeable porous plate 25 is arranged between the filter 24 located on the cover side and the connecting passage 15, and a coil spring 16 is arranged between the porous plate 25 and the cover member 14. The coil spring 16 presses the porous plate 25 toward the port side.

[0042] [3. Sub-chamber]

[0043] The sub-chamber 30 is adjacent to the main chamber 20, has a smaller volume than the main chamber 20, and has an elongated cylindrical shape extending from the cover side to the port side (see Figure 1). In addition, the shape of the sub-chamber 30 is not limited to a cylindrical shape, and may be, for example, a prism shape. An atmospheric port 13 is provided at the end of the sub-chamber 30 located on the port side (hereinafter referred to as the first end F), and the atmospheric port 13 connects the sub-chamber 30 with the outside of the filter tank 1. A filter 31 and a filter 32 are respectively arranged at the first end F of the sub-chamber 30 and the end located on the cover side (hereinafter referred to as the second end S), and an adsorbent 4 is arranged between the filter 31 and the filter 32. In addition, the second end S of the sub-chamber 30 is connected to the connecting channel 15, and a porous plate 33 is arranged between the filter 32 located on the cover side and the connecting channel 15. In addition, similar to the main chamber 20, a coil spring 17 is arranged between the porous plate 33 and the cover member 14, and the coil spring 17 presses the porous plate 33 toward the port side.

[0044] Furthermore, the connection passage 15 is provided along the cover member 14 , and the connection passage 15 connects the main chamber 20 and the sub-chamber 30 to each other. Therefore, inside the canister 1 , the fluid can go back and forth between the main chamber 20 and the sub-chamber 30 via the connection passage 15 .

[0045] Moreover, similarly to the main chamber 20 , in the sub-chamber 30 , the fluid flows in the direction in which the first end F and the second end S are opposed to each other.

[0046] [4.Port]

[0047] The inlet 11 is connected to the fuel tank of the engine of the vehicle (see Figure 1 ). Fuel vapor generated in the fuel tank flows into the canister 1 through the inlet 11 and is adsorbed by the adsorbent 4 in each chamber. Thus, fuel is accumulated in the canister 1.

[0048] In addition, the outflow port 12 is connected to the intake pipe of the engine of the vehicle, and the atmospheric port 13 is connected to the outside of the vehicle and is open to the atmosphere. Moreover, due to the negative intake pressure of the engine, air (in other words, purge air) flows into the interior of the canister 1 through the atmospheric port 13. Due to the inflow of the purge air, the fuel vapor adsorbed on the adsorbent 4 is desorbed, and the desorbed fuel vapor flows from the outflow port 12 to the intake pipe together with the purge air. Thus, the fuel vapor adsorbed on the adsorbent 4 is purged to remove it, and the adsorbent 4 is regenerated.

[0049] [5. Detailed structure of the reduction section]

[0050] Each of the narrowing portions 22 is disposed adjacent to the first end portion F and is formed into a tapered shape as an example (see Figure 1). Specifically, the orthogonal cross-section of each reduction portion 22 is roughly circular. Of course, the orthogonal cross-sectional shape of the reduction portion 22 is not limited to this, and in addition to the roughly circular shape, it can be, for example, roughly elliptical or roughly polygonal. In addition, the axial cross-section of each reduction portion 22 is inclined relative to the flow direction of the fluid in a manner that approaches the axis A as it approaches the port side, and extends in a straight line. The portion of the reduction portion 22 that is inclined relative to the flow direction of the fluid surrounds the area around the first end F, and the reduction portion 22 in the main chamber 20 is provided in this area. In addition, the axial cross-section refers to a cross-section that is parallel to the axis A and includes the axis A. In addition, the axis A refers to a virtual straight line that passes through the inlet 11 or outlet 12 (in other words, the first end F) corresponding to the reduction portion 22 and extends along the flow direction of the fluid.

[0051] In addition, the reduction portion 22 may be provided only for one of the inlet 11 and the outlet 12. In this case, the area around the inlet 11 or the outlet 12 where the reduction portion 22 is not provided may be surrounded by a cylindrical portion having a substantially constant orthogonal cross-sectional shape (in other words, extending substantially along a straight line).

[0052] [6. Modification 1]

[0053] The reduction portion 22 may be provided at a position away from the first end portion F where the inlet 11 and the outlet 12 are provided (see Figure 2 ). Specifically, for example, a reduced portion 22 and a straight portion 26 may be provided around the first end F.

[0054] The reduced portion 22 has a tapered shape, and as one example, the ends of the reduced portion 27 on the cover side and the port side are formed with roundness.

[0055] The straight portion 26 is a portion extending along the flow direction of the fluid on the axial cross section. In other words, the straight portion 26 is a cylindrical shape extending substantially in a straight line. The orthogonal cross section of the straight portion 26 is substantially constant, and its shape is substantially the same as the end surface of the first end F forming the main chamber 20. In addition, the straight portion 26 extends from the first end F to the cover side, and the reduction portion 22 is provided at the end of the straight portion 26 located on the cover side. Moreover, the end of the reduction portion 22 located on the cover side is connected to the main body 21.

[0056] In addition, the shape of the reduction portion 22 is not limited to a cone, and can be set as needed. In addition, a plurality of reduction portions 22 can be provided around the first end portion F. Specifically, Figure 3 As shown, as an example, the reduced portions 22A, 22B may be stepped portions extending in a direction perpendicular to the flow direction of the fluid. That is, the reduced portions 22A, 22B may be inclined at approximately 90° relative to the flow direction of the fluid.

[0057] In addition, if Figure 3 As shown, two first reduced portions 22A, a second reduced portion 22B, and first to third straight portions 26A to 26C having a stepped shape may be provided around the first end F. That is, the first straight portion 26A is provided so as to extend from the first end F of the main chamber 20 toward the cover side, and the first reduced portion 22A is provided at the end of the first straight portion 26A located on the cover side. Furthermore, the second straight portion 26B is provided so as to extend from the end of the first reduced portion 22A located on the outer peripheral side toward the cover side, and the second reduced portion 22B is provided at the end of the second straight portion 26B located on the cover side. Furthermore, the third straight portion 26C is provided so as to extend from the end of the second reduced portion 22B located on the outer peripheral side toward the cover side, and the end of the third straight portion 26C located on the cover side is connected to the main body 21.

[0058] [7. Modification 2]

[0059] The reduction portion 22 may be provided corresponding to the inlet 11 and the outlet 12 (see Figure 4 That is, a reduction portion 22 may be provided in the main chamber 20, and the reduction portion 22 may be provided to extend from a first end portion F of the main chamber 20 where the inlet 11 and the outlet 12 are provided to the cover side.

[0060] exist Figure 4 As an example, the reduction portion 22 is tapered and is disposed adjacent to the first end F. However, the shape, position, and number of the reduction portion 22 may be set as needed. That is, similar to the second modification, the reduction portion 22 may be disposed away from the first end F, or may have a stepped shape. In addition, similar to the first modification, a straight portion and a plurality of reduction portions 22 may be disposed around the first end F.

[0061] [8. Modification 3]

[0062] The granular adsorbent 4 may be arranged in the main chamber 20, and at least one void-forming portion having a predetermined shape may be provided near the inner circumferential surface of the reduction portion 22. In addition, the granular adsorbent 4 may be, for example, granular activated carbon particles. The particles may have various shapes, such as a roughly cylindrical or spherical shape. In addition, in the case where the main chamber 20 is provided with two reduction portions 22, the void-forming portion may be provided in both or one of the two reduction portions 22.

[0063] Specifically, as an example, Figure 5As shown, a plurality of gap forming portions 27 can be arranged to protrude from the inner peripheral surface of the tapered reducing portion 22 toward the axis A of the port adjacent to the reducing portion 22. Each gap forming portion 27 extends along the flow direction of the fluid, and the shape of its cross section orthogonal to the flow direction of the fluid is a rectangular shape as an example. That is, each gap forming portion 27 is plate-shaped. In addition, each gap forming portion 27 is arranged at approximately fixed intervals around the axis A. In addition, the plurality of gap forming portions 27 are the same as the reducing portion 22 and the shell part 10, and are all made of resin, and the plurality of gap forming portions 27 can be formed as one body with the reducing portion 22 and the shell part 10.

[0064] Of course, the shape and arrangement of each gap forming portion 27 can be set as needed. Specifically, for example, each gap forming portion 27 can be a rib-shaped portion protruding from the inner circumferential surface of the reduction portion 22 and extending along the flow direction of the fluid. In addition, each gap forming portion 27 can also extend in a direction different from the flow direction of the fluid. In addition, each gap forming portion 27 can be a rod-shaped portion protruding from the inner circumferential surface of the reduction portion 22. Each gap forming portion 27 can be set at a specific position of the inner circumferential surface, rather than being set circumferentially around the axis A.

[0065] In addition, when the straight portion 26 is provided adjacent to the reduced portion 22 , each gap forming portion 27 may be provided to straddle the reduced portion 22 and the straight portion 26 .

[0066] In addition, the top of each gap forming portion 27 extends along the boundary of the front region 20A. In addition, the front region 20A refers to a region extending from the end surface of the first end F in the main chamber 20 where the inlet 11 or the outlet 12 is formed to the cover side along the flow direction of the fluid. The front region 20A is a columnar region, and the shape of the cross section of the front region 20 orthogonal to the extension direction of the front region 20 is substantially the same as the end surface. Of course, the shape of the top of each gap forming portion 27 is not limited to this, and can be set as needed.

[0067] In addition, the plurality of gap forming portions 27 may be configured as a component separate from the reduction portion 22. That is, the plurality of gap forming portions 27 may be formed separately from the reduction portion 22 and mounted to the inner circumferential surface of the reduction portion 22 or arranged near the inner circumferential surface. In addition, a gap forming portion may be provided in the inner circumferential surface of the reduction portion 22 in the same manner. In addition, at least one gap forming portion may be provided in the reduction portion 22 of Modification 1 and Modification 2 in the same manner.

[0068] [9. Effect]

[0069] (1) In a chamber having a port in a canister, a region where the fluid flows relatively well is considered to be a region that spreads out in a roughly fan-shaped manner from the port along the flow direction of the fluid. Therefore, around the port of the chamber, the flow of the fluid may stagnate in a region surrounding the side wall of the chamber from the side, and this region may become an ineffective space where the adsorbent cannot fully adsorb and desorb the fuel vapor.

[0070] In this regard, according to the above-mentioned embodiment, the dead space can be reduced by providing the reduction portion 22 at the first end F of the main chamber 20, and the flow of the fluid around the first end F in the main chamber 20 can be improved. Therefore, it is possible to promote the smooth flow of the fluid in the canister 1. As a result, the desorption performance of the fuel vapor adsorbed on the adsorbent can be improved. Moreover, due to the improvement of the desorption performance, the fuel vapor can be effectively accumulated using a small amount of the adsorbent 4, thereby improving the adsorption performance of the fuel vapor.

[0071] (2) In addition, it is conceivable that the flow velocity of the purge air around the outflow port 12 of the main chamber 20 may decrease when purging is performed. In view of this, by providing the narrowing portion 22 around the outflow port 12, it is possible to suppress the decrease in the flow velocity of the purge air around the outflow port 12 of the main chamber 20. Therefore, it is possible to promote the smooth outflow of the fuel vapor accumulated in the canister 1 from the outflow port 12 when purging is performed, thereby improving the desorption performance.

[0072] (3) In addition, the inclined portion of the narrowing portion 22 surrounds the area around the first end F of the main chamber 20 where the corresponding port is provided. Therefore, in the main chamber 20, the flow of the fluid around the first end F can be further improved. Thus, the fluid can flow more smoothly in the canister 1.

[0073] (4) Furthermore, since the narrowing portion 22 is tapered, the flow of the fluid around the first end F of the main chamber 20 can be improved. Therefore, the fluid can flow smoothly in the canister 1.

[0074] (5) Furthermore, by providing the space forming portion 27 in the reduced portion 22, a space can be formed around the space forming portion 27 and the granular adsorbent abutting against the space forming portion 27. Therefore, the ventilation resistance inside the reduced portion 22 can be reduced.

[0075] [10. Other embodiments]

[0076] (1) In the above embodiment, the main chamber 20 and the reduction portion 22 are formed by the shell member 10 forming the outer peripheral surface of the filter tank 1. However, the filter tank 1 is not limited thereto, and may also include an outer shell forming the outer peripheral surface and a shell member as an inner shell disposed inside the outer shell. Furthermore, the main chamber having the reduction portion similar to that in the above embodiment may be formed by the shell member as the inner shell.

[0077] Furthermore, a plurality of main chambers arranged along the flow direction of the fluid may be provided in the canister 1. In this case, the main chambers adjacent to the inlet 11 and the outlet 12 may have the same narrowing portion 22 as in the above embodiment.

[0078] (2) In the above embodiment, the portion of the reduction portion 22 that is inclined relative to the flow direction of the fluid is formed as an area surrounding the first end F of the main chamber 20 where the corresponding port is provided. However, the inclined portion may not surround the area. In other words, the reduction portion may be provided with an inclined portion that is inclined relative to the flow direction of the fluid and a non-inclined portion that extends substantially linearly along the flow direction of the fluid. Even in the above-mentioned reduction portion, the orthogonal cross section of the area surrounded by the reduction portion in the main chamber 20 can be reduced as it approaches the corresponding port.

[0079] (3) Multiple functions of one component in the above-mentioned embodiment may be realized by multiple components, or one function of one component in the above-mentioned embodiment may be realized by multiple components. In addition, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. In addition, part of the structure of the above-mentioned embodiment may be omitted. At least part of the structure of the above-mentioned embodiment may be added to the structure of the above-mentioned other embodiment, or at least part of the structure of the above-mentioned embodiment may be replaced with the structure of the above-mentioned other embodiment.

[0080] [11. Technical ideas disclosed in this specification]

[0081] [Project 1]

[0082] A canister is installed in a vehicle having an engine, wherein the canister is characterized by comprising:

[0083] a plurality of chambers, wherein an adsorbent for adsorbing fuel vapor is disposed in the plurality of chambers;

[0084] a housing member forming a main chamber as one of the plurality of chambers;

[0085] an inlet provided at a first end portion of the main chamber and configured to allow fuel vapor to flow from a fuel tank of the vehicle into the main chamber;

[0086] an atmospheric port configured to be open to the atmosphere and provided in a sub-chamber that is one of the plurality of chambers; and

[0087] an outflow port, the outflow port being provided at the first end portion of the main chamber and being configured to allow the fuel vapor adsorbed in the adsorbent to flow out toward the engine by the atmosphere flowing in from the atmosphere port;

[0088] The housing member has at least one reduced portion, the reduced portion being a wall-shaped portion forming a region around the first end portion in the main chamber.

[0089] The reduction portion is configured such that an area of ​​a cross section perpendicular to a flow direction of the fluid in the main chamber decreases toward the first end.

[0090] [Project 2]

[0091] The filter tank according to item 1 is characterized in that:

[0092] The narrowing portion is a wall-shaped portion that forms a peripheral region of the first end portion of the main chamber where the inlet is provided, and the narrowing portion is configured such that the cross section of the region decreases toward the inlet.

[0093] [Item 3]

[0094] The filter tank according to item 1 or 2 is characterized in that:

[0095] The narrowing portion is a wall-shaped portion that forms a peripheral region of the first end portion of the main chamber where the outflow port is provided, and the narrowing portion is configured such that the cross section of the region decreases toward the outflow port.

[0096] [Item 4]

[0097] The filter tank according to any one of items 1 to 3 is characterized in that

[0098] The narrowing portion has a portion inclined with respect to the flow direction, and the portion surrounds a region around the first end portion in the main chamber.

[0099] [Item 5]

[0100] The filter tank according to any one of items 1 to 4, characterized in that

[0101] The narrowing portion extends linearly in an axial cross section, wherein the axis is a line passing through the first end portion where the narrowing portion is provided and is a line extending along the flow direction, and the axial cross section is a cross section including the axis.

[0102] [Item 6]

[0103] The filter tank according to any one of items 1 to 5, characterized in that

[0104] A granular adsorbent is disposed in the main chamber.

[0105] At least one gap forming portion is provided near the inner peripheral surface of the narrowed portion, and the at least one gap forming portion has a predetermined shape.

Claims

1. A canister installed in a vehicle having an engine, wherein the canister is characterized by: a plurality of chambers, wherein an adsorbent for adsorbing fuel vapor is disposed in the plurality of chambers; a housing member forming a main chamber as one of the plurality of chambers; an inlet provided at a portion of a first end portion of the main chamber and configured to allow fuel vapor to flow from a fuel tank of the vehicle into the main chamber; an atmospheric port configured to be open to the atmosphere and provided in a sub-chamber that is one of the plurality of chambers; and an outflow port, the outflow port being provided at the first end portion of the main chamber and being configured to allow the fuel vapor adsorbed in the adsorbent to flow out toward the engine by the atmosphere flowing in from the atmosphere port; The housing member has at least one reduced portion, and the at least one reduced portion is a wall-shaped portion forming an area around the first end portion in the main chamber. The at least one reduction portion is configured such that an area of ​​a cross section perpendicular to a flow direction of the fluid in the main chamber decreases toward the first end.

2. The filter tank according to claim 1, characterized in that: The at least one narrowing portion is a wall-shaped portion that forms a peripheral area of ​​the first end portion of the main chamber where the inlet is provided, and the at least one narrowing portion is configured such that the cross section of the area decreases toward the inlet.

3. The filter tank according to claim 1, characterized in that: The at least one narrowing portion is a wall-shaped portion that forms a peripheral area of ​​the first end portion of the main chamber where the outflow port is provided, and the at least one narrowing portion is configured such that the cross section of the area decreases toward the outflow port.

4. The filter tank according to claim 1, characterized in that: A plurality of reduction portions are provided as the at least one reduction portion, One of the plurality of reduction portions is a wall-shaped portion that forms a peripheral area of ​​the first end portion of the main chamber where the inlet is provided, and one of the plurality of reduction portions is configured such that the cross section of the region decreases as it approaches the inlet. One of the plurality of reduction portions is a wall-shaped portion that forms a peripheral area of ​​the first end portion of the main chamber where the outflow port is provided, and one of the plurality of reduction portions is configured such that the cross section of the area decreases toward the outflow port.

5. The filter tank according to any one of claims 1 to 4, characterized in that: The at least one narrowing portion includes a portion inclined with respect to the flow direction, and the portion surrounds a region around the first end portion in the main chamber.

6. The filter tank according to any one of claims 1 to 5, characterized in that: The at least one narrowing portion extends linearly on an axial cross section, wherein the axis is a line passing through the first end portion where the at least one narrowing portion is provided and is a line extending along the flow direction, and the axial cross section is a cross section including the axis.

7. The filter tank according to any one of claims 1 to 6, characterized in that: The at least one narrowing portion is tapered.

8. The filter tank according to any one of claims 1 to 7, characterized in that: A granular adsorbent is disposed in the main chamber. At least one gap forming portion is provided near the inner peripheral surface of the at least one narrowing portion, and the at least one gap forming portion has a predetermined shape.

9. The filter tank according to claim 8, characterized in that: The at least one gap forming portion is a plate-shaped portion that protrudes from the inner peripheral surface of the at least one reduced portion.

10. The filter tank according to claim 9, characterized in that: The at least one gap forming portion is a plurality of plate-shaped portions protruding from the inner circumferential surface of the at least one reduction portion, and the at least one gap forming portion is arranged at approximately fixed intervals around an axis, wherein the axis is a line extending along the flow direction and passing through the inlet or the outlet.

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