JP2008208821A - Dust filter for evaporating fuel treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit rise of ventilation resistance while improving filtering performance. <P>SOLUTION: A dust filter 40 is provided with a downstream side filter member 64 collecting duct contained in air flowing in an atmospheric air introduction route in an evaporating fuel treatment device, an upstream side filter member 67 arranged in an upstream side of the downstream side filter member 64 and having coarser mesh than mesh of the downstream side filter member 64, and a bypass passage 57 bypassing part of air flowing to an upstream side of the downstream side filter member 64 from upstream side of the upstream side filter member 67. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention mainly relates to a dust filter of an evaporative fuel processing device installed in a vehicle such as an automobile.

  Conventionally, in an evaporative fuel processing apparatus, the adsorbent in the canister may be clogged by dust contained in the atmosphere. For this reason, in the thing of patent document 1, the filter which collects the dust so-called dust contained in air | atmosphere is provided in the air introduction | transmission opening | mouth of the canister.

JP 2003-252071 A

According to the filter of Patent Document 1, only a filter member made of a foam material that collects dust contained in the air flowing through the atmosphere introduction path is disposed. Therefore, if the filter member is made finer, the filtration performance is improved, but the ventilation resistance is increased. Conversely, if the filter member is made coarser, the increase in the ventilation resistance is suppressed, but the filtration performance is lowered. . For this reason, there is a problem that it is difficult to achieve both filtration performance and suppression of increase in ventilation resistance.
The problem to be solved by the present invention is to provide a dust filter for an evaporative fuel treatment apparatus that can suppress an increase in ventilation resistance while improving filtration performance.

The above-described problem can be solved by a dust filter of an evaporative fuel processing apparatus having the gist of the configuration described in the claims.
That is, according to the dust filter of the evaporated fuel processing apparatus according to claim 1 of the claims, of the dust contained in the air flowing through the atmosphere introduction path, large dust is collected by the upstream filtering member, and Small dust is collected from the downstream filtration member. For this reason, dust can be collected stepwise by the upstream filtration member and the downstream filtration member, and the filtration performance can be improved. Further, since the amount of dust collected by the downstream filtration member is reduced, an increase in the ventilation resistance of the downstream filtration member can be suppressed. In addition, by providing a bypass passage that bypasses a part of the air flowing from the upstream side of the upstream filtering member to the upstream side of the downstream filtering member, when the air is allowed to flow entirely through the upstream filtering member In comparison, an increase in ventilation resistance can be suppressed. Therefore, it is possible to suppress an increase in ventilation resistance while improving the filtration performance.

  Further, according to the dust filter of the fuel vapor processing apparatus according to claim 2 of the claims, the filtration passage for disposing the upstream filtration member is formed on the ground side in the vertical direction with respect to the bypass passage. For this reason, the filter member on the upstream side of the filter passage disposed on the ground side in the top-and-bottom direction can easily collect heavy dust, and the dust having a small weight can be collected by the filter member on the downstream side through the bypass passage. It is easy to collect. Therefore, dust in the air can be collected efficiently.

  Moreover, according to the dust filter of the evaporative fuel processing apparatus of claim 3, the upstream side of the casing formed in a shape surrounding at least a part of the periphery of the fuel inlet of the inlet pipe of the fuel tank is provided. The filter member and the downstream filter member are accommodated. Therefore, the oil filler opening of the inlet pipe can be protected from an impact during a collision using the casing.

  Next, the best mode for carrying out the present invention will be described with reference to examples.

[Example 1]
The dust filter of the evaporative fuel processing apparatus concerning Example 1 of this invention is demonstrated. In this embodiment, for convenience of explanation, the dust filter will be described after the outline of the evaporated fuel processing apparatus is described. In addition, FIG. 1 is a block diagram which shows an evaporative fuel processing apparatus.
As shown in FIG. 1, an evaporative fuel processing apparatus 10 includes a canister 20 provided in the middle of a purge path 18 that connects a fuel tank 12 mounted on a vehicle such as an automobile and an intake pipe 16 of an engine (internal combustion engine) 14. The evaporative fuel is adsorbed by the adsorbent 22 inside. Depending on the operating state of the engine 14, the purge valve 24 provided in the purge path 18 is opened and closed. Thereby, the evaporated fuel adsorbed by the adsorbent 22 in the canister 20 is introduced into the intake pipe 16 through the purge path 18.

  The fuel tank 12 is provided with an inlet pipe 30 having a fuel filler port 31. The inlet pipe 30 is a pipe for introducing fuel into the fuel tank 12 from the fuel filler port 31, and the fuel filler port 31 is opened obliquely upward. A cap 33 is detachably attached to the fuel filler port 31. Further, the inlet pipe 30 and the fuel tank 12 are communicated with each other by a breather path 35.

  The canister 20 prevents the evaporated fuel from being released into the atmosphere through the atmosphere introduction path 26 by adsorbing the evaporated fuel generated in the fuel tank 12 with an adsorbent 22 made of activated carbon or the like. It is. The evaporated fuel adsorbed by the canister 20 is burned by the engine 14 by being introduced into the intake pipe 16 through the purge path 18 using the intake pipe negative pressure when the purge valve 24 is open. At that time, air is introduced through the air introduction path 26. The air introduction path 26 reduces pressure fluctuations generated in the fuel tank 12 by introducing air from the atmosphere into the fuel tank 12 or discharging air from the fuel tank 12 to the atmosphere. The pressure fluctuation generated in the fuel tank 12 includes, for example, a negative pressure caused by fuel consumption, temperature drop, purge, and the like, and a positive pressure caused by the generation of evaporated fuel due to temperature rise, fuel fluctuation, and the like. In FIG. 1, reference numeral 37 denotes a throttle valve, 38 denotes an air cleaner, and 39 denotes an air cleaner element.

  Thus, the oil filler 31 of the inlet pipe 30 is provided with a dust filter 40 having a shape surrounding at least a part of the periphery of the oil filler 31. The dust filter 40 of the present embodiment communicates with the atmosphere side end portion of the atmosphere introduction path 26 disposed in the periphery of the oil filler port 31 of the inlet pipe 30, and filters the air introduced into the atmosphere introduction path 26. By doing so, it is provided to remove dust in the atmosphere. 2 is a sectional view showing the dust filter, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 is a schematic diagram showing the outline of the dust filter, and FIG. FIG. 6 is a side sectional view schematically showing the air outlet side. Each drawing is accompanied by an orientation. In addition, about front and rear, right and left, it can change suitably.

  As shown in FIGS. 2 and 3, the dust filter 40 includes a casing 42. The casing 42 is made of, for example, resin and has a semi-cylindrical shape surrounding the lower half side of the oil filler port 31 of the inlet pipe 30 (see FIG. 1) over almost a half circumference. It is a filler opening arrangement part. The casing 42 includes a semi-cylindrical inner peripheral wall portion 43, a semi-cylindrical outer peripheral wall portion 44 that is parallel to the outer peripheral side of the inner peripheral wall portion 43 at a predetermined interval, an inner peripheral wall portion 43, and an outer peripheral portion. A hollow space surrounded by both peripheral end wall portions 45 and 46 (see FIG. 2) that closes between both end surfaces in the circumferential direction of the wall portion 44, and the inner peripheral wall portion 43, the outer peripheral wall portion 44, and both the peripheral end wall portions 45 and 46. It has arc-shaped upper and lower end plate portions 47 and 48 (see FIG. 3) for closing both opening end surfaces in the axial direction (the front and back direction in FIG. 2), and the hollow portion forms a semi-cylindrical shape. It is a sealed internal space.

  A first partition wall 50 extending in the radial direction and extending in the axial direction between the inner peripheral wall 43 and the outer peripheral wall 44 on one end side (left end side in FIG. 2) of the casing 42 in the circumferential direction. Is formed. The upper edge portion of the first partition wall portion 50 is joined to the upper end plate portion 47, and the lower edge portion thereof is opposed to the lower end plate portion 48 at a predetermined interval ( (See FIGS. 4 and 5.) As a result, the internal space of the casing 42 is communicated with the upstream air passage 53 and the downstream air through the air passage communication portion 52 between the lower end plate portion 48 and the first partition wall portion 50. It is divided into a passage 54.

  Between the inner peripheral wall portion 43 and the outer peripheral wall portion 44 between the peripheral end wall portion 45 on the one end side in the circumferential direction of the casing 42 (left end side in FIG. 2) and the first partition wall portion 50, there is a diameter. A second partition wall 55 extending in the direction and extending in the axial direction is formed. The upper edge portion of the second partition wall portion 55 is opposed to the upper end plate portion 47 with a predetermined interval, and the lower edge portion is opposed to the lower end plate portion 48 with a predetermined interval. (See FIGS. 4 and 5). Thereby, the air passage 53 on the upstream side of the casing 42 is partitioned into two branch passages. Of the two branch passages, the branch passage on the first partition wall portion 50 side is set as the filtration passage 56, and the branch passage on the peripheral end wall portion 45 side is set as the bypass passage 57. A space between the upper end plate portion 47 and the second partition wall portion 55 is a communication portion 58 on the inlet side of the upstream air passage 53, and the lower end plate portion 48 and the second partition wall portion 55 are connected to each other. A communication portion 59 on the outlet side of the upstream air passage 53 is formed between the wall portion 55 and the wall portion 55. The communication part 59 on the outlet side communicates with the air passage communication part 52. The inlet-side communication portion 58 corresponds to “upstream side of the upstream filtration member” in the present specification. Further, the communication part 59 on the outlet side corresponds to “an upstream side of the downstream filtering member” in the present specification.

  An air inlet 60 that opens the communication portion 58 on the inlet side to the atmosphere is formed in an upper portion of the peripheral end wall portion 45 on one end side in the circumferential direction of the casing 42 (left end side in FIG. 2) (see FIGS. 4 and 4). See FIG. As a result, air in the atmosphere is introduced into the communication portion 58 on the inlet side through the air inlet 60 (see arrow Y1 in FIGS. 4 and 5). The air inlet 60 can be set at an arbitrary position as long as it is a wall portion facing the communication portion 58 on the inlet side.

  As shown in FIG. 2, in the downstream air passage 54, a first support piece 61 that protrudes radially outward and extends in the axial direction is provided on the inner peripheral wall portion 43. It is formed so as to be parallel to the portion 50 at a predetermined interval. The front end edge of the first support piece 61 is opposed to the outer peripheral wall portion 44 with a predetermined interval. Further, a second support piece 62 that protrudes radially inward and extends in the axial direction is provided on the outer peripheral wall portion 44, and the peripheral end wall portion on the other end side (right end side in FIG. 2) in the circumferential direction of the casing 42. It is formed to be parallel to 46 with a predetermined interval. The leading edge of the second support piece 62 is opposed to the inner peripheral wall portion 43 with a predetermined interval.

  An air outlet 63 that opens an air outlet 66 (described later) of the downstream air passage 54 is provided at the lower portion of the peripheral wall 46 on the other end side in the circumferential direction of the casing 42 (right end in FIG. 2). It is formed (see FIG. 2). The air outlet port 63 communicates with the atmosphere side end of the atmosphere introduction path 26 (see FIG. 1). As a result, the air in the downstream air passage 54 flows out to the atmosphere introduction path 26 (see FIG. 1) through the air outlet 63 and is further introduced into the canister 20. The air outlet 63 can be set at any position as long as the wall faces the air outlet 66 (described later) of the downstream air passage 54 in the casing 42.

  As shown in FIG. 2, a downstream filtering member 64 is disposed in the downstream air passage 54. The downstream filter member 64 is formed by bending a filter material made of filter paper, nonwoven fabric or the like into a pleat shape. One end portion (left end portion in FIG. 2) 64a in the circumferential direction of the downstream filtration member 64 is joined in a state of being fitted to the first support piece 61. Further, the other end portion (the right end portion in FIG. 2) 64 b in the circumferential direction of the downstream filtration member 64 is joined in a state of being fitted to the second support piece 62. Moreover, the upper edge part of the downstream filtration member 64 is joined to the said upper end plate part 47, and the lower end edge is joined to the said lower end plate part 48 (refer FIG. 3). Thereby, the downstream filtration member 64 completely traverses the inside of the downstream air passage 54. Therefore, the downstream air passage 54 is partitioned into two spaces by the downstream filter member 64. Out of the two space portions, the space portion on the outer peripheral side of the downstream filtration member 64 serves as the air introduction portion 65 communicating with the air passage communication portion 52, and the space portion on the inner periphery side thereof serves as the air outlet port. The air outlet 66 is in communication with the air outlet 63 (see FIG. 2).

  An upstream filtration member 67 is disposed in the filtration passage 56 of the upstream air passage 53. The upstream filtering member 67 is formed in a block shape by a filtering material made of a foaming material such as urethane having air permeability. Further, the upstream filtration member 67 is fully loaded in the filtration passage 56 in the upstream air passage 53.

  Thus, the downstream filtering member 64 is a main filtering member and has an eye that can appropriately collect dust contained in the air passing through the casing 42. The upstream-side filter member 67 is a sub-filter member, and captures larger dust out of dust that is coarser than the eyes of the downstream-side filter member 64, that is, dust contained in the air passing through the casing 42. Has eyes that can be collected.

  The casing 42 has a coupling structure with a plurality of divided bodies, and is configured by coupling a plurality of divided bodies to each other so as to accommodate the downstream filtering member 64 and the upstream filtering member 67. Has been. The casing 42 is fixed to the oil supply port 31 with appropriate fixing means such as screwing means and clip means (not shown) in a state where the oil supply port arrangement portion is fitted to the oil supply port 31 of the inlet pipe 30. In addition, the casing 42 is also provided in an inclined shape along the oil supply port 31 because the oil supply port 31 is opened obliquely upward (see FIGS. 3, 5, and 6). Therefore, when the dust filter 40 is mounted on the vehicle, the downstream-side filter member 64 faces the inner peripheral side (upper side in FIGS. 2 and 3) toward the top side (upper side) and the outer peripheral side (lower side in FIGS. 2 and 3). ) On the ground side (lower side) (see FIG. 2). At the same time, the bypass passage 57 is disposed on the top side (upper side), and the filtration passage 56 in which the upstream filtration member 67 is disposed is disposed on the ground side (lower side) (see FIGS. 2 and 5).

  In the dust filter 40, the atmosphere, that is, air flows into the communication portion 58 on the inlet side of the upstream air passage 53 through the air inlet 60 (see arrow Y 1 in FIGS. 2, 4 and 5). . The air flows after being divided into the filtration passage 56 and the bypass passage 57. The air flowing through the filtration passage 56 (see Y2 in FIGS. 4 and 5) is filtered by passing through the upstream filtration member 67 and flows out to the communication part 59 on the outlet side. At this time, the upstream filtering member 67 collects large dust among the dust contained in the air passing through the upstream air passage 53. Further, a part of the air flowing through the upstream air passage 53, that is, the air other than the air flowing through the filtration passage 56 (see Y3 in FIGS. 4 and 5) flows out by bypassing the bypass passage 57, thereby exiting. It flows out to the communication part 59 on the side.

  The air that has passed through the filtration passage 56 and the bypass passage 57 (see Y2 and Y3 in FIGS. 4 and 5) joins at the communication portion 59 on the outlet side, and then downstream through the air passage communication portion 52. Into the air introduction portion 65 of the air passage 54. The air is filtered by passing the filter member 64 on the downstream side from the outer peripheral side to the inner peripheral side in the radial direction, and flows out to the air outlet 66 (see arrow Y4 in FIG. 2). At this time, small dust contained in the air passing through the downstream air passage 53 is collected by the downstream filtering member 64. Further, the filtered air flows out through the air outlet 63 (see arrow Y5 in FIGS. 2, 4 and 6). The air is introduced into the canister 20 through the air introduction path 26 as shown in FIG.

  According to the dust filter 40 of the fuel vapor processing apparatus 10 described above, among the dust contained in the air flowing through the atmosphere introduction path 26, large dust is collected by the upstream filtering member 67, and small dust is downstream. It is collected from the filtration member 64 on the side (see FIG. 4). For this reason, the upstream filtering member 67 and the downstream filtering member 64 can collect dust in stages and improve the filtration performance. In addition, since the amount of dust collected by the downstream filtration member 64 is reduced, an increase in ventilation resistance of the downstream filtration member 64 can be suppressed.

  Further, in the upstream air passage 53, the air flowing from the inlet side communication portion 58 that is upstream of the upstream filtration member 67 to the outlet side communication portion 59 that is upstream of the downstream filtration member 64. A bypass passage 57 for bypassing a part is provided (see FIG. 4). Thereby, an increase in ventilation resistance can be suppressed as compared with the case where air is entirely flowed through the upstream filtering member 67. Therefore, it is possible to suppress an increase in ventilation resistance while improving the filtration performance.

  In addition, a filtration passage 56 in which the upstream filtration member 67 is disposed is formed on the ground side in the vertical direction with respect to the bypass passage 57 (see FIG. 5). For this reason, the filter member 67 upstream of the filter passage 56 disposed on the ground side in the top-and-bottom direction can easily collect heavy dust, and the light dust can be collected downstream through the bypass passage 57. It can be easily collected by the filtering member 64. Therefore, dust in the air can be collected efficiently.

  Further, the downstream-side filter member 64 and the upstream-side filter member 67 are housed in a casing 42 formed in a shape that surrounds the lower half side of the fuel filler port 31 of the inlet pipe 30 of the fuel tank 12 over almost a half circumference. (See FIGS. 2 and 3). Therefore, the oil filler port 31 of the inlet pipe 30 can be protected from an impact at the time of a collision using the casing. The casing 42 is changed to a cylindrical shape such as a cylindrical shape or a rectangular tube shape that surrounds the oil supply port 31 of the inlet pipe 30 over the entire circumference, so that the oil supply port of the inlet pipe 30 against an impact at the time of a collision or the like. The protection performance of 31 can be further improved. In this case, the casing 42 can be set to an appropriate shape such as a C shape, a cylindrical shape, a rectangular tube shape, and a D shape in addition to the semicylindrical shape.

  Further, the downstream filtering member 64 is formed in an arc shape in cross section, and is configured to flow by flowing air in the radial direction from the outer peripheral side to the inner peripheral side of the downstream filtering member 64 (in FIG. 2). , See arrow Y4). That is, by setting a surface for collecting dust on the outer peripheral side of the downstream-side filtration member 64 formed in a circular arc shape in cross section, the area of the surface for collecting dust of the downstream-side filtration member 64 is increased. Can do.

  Further, in the installation of the dust filter 40, the outer peripheral side of the downstream filtering member 64, that is, the surface for collecting dust is directed to the ground side in the vertical direction (see FIGS. 2 and 3). Thereby, dust collected on the outer peripheral side of the downstream filtering member 64 is likely to be peeled off or dropped from the outer peripheral side of the downstream filtering member 64 due to gravity, vehicle vibration, positive pressure during refueling, or the like. An increase in the ventilation resistance of the downstream filtration member 64 can be suppressed.

[Example 2]
A second embodiment of the present invention will be described. In this embodiment, the configuration of the upstream air passage 53 including the upstream filter member 67 in the dust filter 40 (see FIGS. 2 to 5) of the first embodiment is changed, and therefore the details of the change are described. Will be described, and redundant description will be omitted. FIG. 7 is a cross-sectional view showing the dust filter, and FIG. 8 is a configuration diagram showing an outline of the dust filter.
That is, as shown in FIG. 7, the first partition wall 50 and the second partition wall 55 are omitted from the casing 42. As a result, the upstream air passage (reference numeral 153) communicates with the air passage between the outer peripheral wall portion 44 of the casing 42 and one end portion (left end portion in FIG. 7) 64a of the downstream filtration member 64. As a part (reference numeral 152 is attached), it communicates with the air introduction part 65 of the downstream air passage 54.

  As shown in FIG. 8, an upstream filtering member (reference numeral 167 is attached) is disposed in the middle portion in the vertical direction of the upstream air passage 153. The upstream filtration member 167 is formed in a block shape by a filtration material made of a foaming material such as urethane having air permeability. Further, the upstream filtering member 167 is fully loaded in the intermediate portion in the vertical direction of the upstream air passage 153. Thereby, the upstream air passage 153 is divided into two branch passages. Of the two branch passages, the lower space including the upstream-side filtration member 167 is set as a filtration passage (denoted by reference numeral 156) that also serves as the communication portion on the outlet side, and the upper space of the upstream-side filtration member 167. Is set to a bypass passage (reference numeral 157) also serving as a communication portion on the inlet side. The upper space of the upstream filter member 167 corresponds to the “upstream side of the upstream filter member” in this specification. Further, the space below the upstream filter member 167 corresponds to the “upstream side of the downstream filter member” in this specification.

  In the dust filter (reference numeral 140), the atmosphere, that is, air flows through the air inlet 60 into the space above the upstream filter member 167, that is, into the bypass passage 157 (in FIGS. 7 and 8, arrows). (See Y1 '.) Part of the air is diverted to the filtration passage 156. Air flowing through the filtration passage 156 (see Y2 ′ in FIG. 8) is filtered by passing through the upstream filtration member 167. At this time, the upstream filtering member 167 collects large dust among the dust contained in the air passing through the upstream air passage 153. The air that has passed through the upstream filtering member 167 flows out to the air introduction portion 65 of the downstream air passage 54 via the space below the upstream filtering member 167. Further, a part of the air passing through the upstream filtration member 167 flows out to the air introduction portion 65 of the downstream air passage 54 without passing through the space below the upstream filtration member 167 (in FIG. 8, (See Y2 ″.) Further, a part of the air that has flowed into the bypass passage 157, that is, air other than the air flowing through the filtration passage 156 (see Y3 ′ in FIG. 8), is an air introduction portion 65 of the air passage 54 on the downstream side from the bypass passage 157. To leak.

  The air (refer to Y2 ′, Y2 ″, and Y3 ′ in FIG. 8) that has passed through the filtration passage 156 and the bypass passage 157 and has flowed into the air introduction portion 65 of the downstream air passage 54 is the above-described implementation. Similarly to Example 1, after passing through the downstream filtering member 64 in the radial direction from the outer peripheral side to the inner peripheral side, the air is filtered and flows out to the air outlet 66 (in FIGS. 7 and 8, arrows Y4), and flows out through the air outlet 63 (see arrows Y5 in FIGS. 7 and 8).

Also with the above-described dust filter 140, the same operation and effect as the dust filter 40 of the first embodiment can be obtained.
Moreover, in the casing 42, the 1st division wall part 50 and the 2nd division wall part 55 are abbreviate | omitted, and the structure of the casing 42 can be simplified.

  The present invention is not limited to the above-described embodiments, and modifications can be made without departing from the gist of the present invention. For example, the dust filters 40 and 140 of the present invention can be provided at an arbitrary position as long as they are on the atmosphere introduction path of the evaporated fuel processing apparatus 10. In addition, the downstream filtration member 64 can be made of a filtration material such as a foamed material such as urethane, in addition to a filtration material such as filter paper and nonwoven fabric. In addition, the upstream filter members 67 and 167 can be made of a filter material such as a filter paper or a non-woven fabric, in addition to a foam filter material such as urethane. Further, the downstream filtering member 64 and the upstream filtering members 67 and 167 may be made of different filtering materials. Not only the filtering members of different materials but also the filtering materials of the same material can be used. . Further, the downstream-side filtration member 64 and / or the upstream-side filtration members 67 and 167 are not limited to a single layer, but can be formed into two or three layers. Further, the casing 42, the downstream filter member 64, the upstream filter members 67, 167, and the like are not limited to those of the above-described embodiment, and can be changed to appropriate shapes.

It is a block diagram which shows the evaporative fuel processing apparatus concerning Example 1 of this invention. It is sectional drawing which shows a dust filter. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is a block diagram which shows the outline of a dust filter. It is side sectional drawing which shows the outline of the air introduction side of a dust filter. It is a sectional side view showing the outline of the air outlet side of the dust filter. It is sectional drawing which shows the dust filter concerning Example 2 of this invention. It is a block diagram which shows the outline of a dust filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Evaporative fuel processing apparatus 12 Fuel tank 26 Atmospheric introduction path 30 Inlet pipe 31 Refueling port 40 Dust filter 42 Casing 56 Filtration passage 57 Bypass passage 64 Downstream filtration member 67 Upstream filtration member 140 Dust filter 156 Filtration passage 157 Bypass passage 167 upstream filtering member

Claims (3)

A dust filter for an evaporative fuel treatment device provided on an air introduction path in the evaporative fuel treatment device,
A downstream filtration member that collects dust contained in the air flowing through the atmosphere introduction path;
An upstream filtration member disposed upstream of the downstream filtration member and having a coarser grain than the downstream filtration member;
And a bypass passage for bypassing a part of the air flowing from the upstream side of the upstream filtering member to the upstream side of the downstream filtering member. It is a dust filter of the evaporative fuel processing apparatus according to claim 1,
A dust filter for an evaporative fuel processing apparatus, wherein a filtration passage for arranging the upstream filtration member is formed on a ground side in a vertical direction with respect to the bypass passage. It is a dust filter of the evaporative fuel processing device according to claim 1 or 2,
An evaporative fuel characterized in that the upstream filtration member and the downstream filtration member are accommodated in a casing formed in a shape surrounding at least a part of the periphery of a fuel filler inlet of a fuel tank inlet pipe. Dust filter for processing equipment.

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