JP4717844B2 - Dust filter for evaporative fuel processing equipment - Google Patents

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 in Patent Document 1, the filtering member (corresponding to “filter layer 32D” in Patent Document 1) is formed in a cylindrical shape. And in 1st Embodiment (refer FIG.1 and FIG.2), air flows into the axial direction of a filtration member. Moreover, in 7th Embodiment (refer FIG. 9), air is introduce | transduced into the inside from the outer peripheral side of the radial direction of a filtration member, and flows toward the downward direction of an axial direction. In the tenth embodiment (see FIG. 13), air is introduced from the upper end side in the axial direction of the filtration member into the inside and flows inward in the radial direction. Therefore, in what introduce | transduces air into an axial direction from the upper end surface of the axial direction of a filtration member (1st Embodiment (refer FIG.1 and FIG.2) and 10th Embodiment (refer FIG.13)), It is difficult to increase or decrease the filtration area of the filter member without changing the radial dimension (outer diameter and / or inner diameter) of the filter member. Further, the flow of air flowing in the filtering member is bent from the radially inner side to the axial direction (seventh embodiment (see FIG. 9)), or the flow of air flowing in the filtering member is changed from the axial direction to the radial direction. In the case of bending inward in the direction (the tenth embodiment (see FIG. 13)), the flow of backflowing air is impaired. Therefore, dust collected on the air introduction side surface of the filtration member is removed from the backflow of air. The effect of peeling using is small.

  The problem to be solved by the present invention is an evaporative fuel that can increase and decrease the filtration area of the filter member without changing the radial dimension of the filter member, and can improve the dust separation effect due to the backflow of air It is providing the dust filter of a processing apparatus.

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 fuel vapor processing apparatus according to claim 1 of the claims, the air flowing through the air introduction path leading to the canister is filtered by passing through the filter member of the filter chamber in the casing, and the filter member As a result, dust contained in the air is collected.
Further, since the filtration member is formed in a circular arc shape, the filtration member is different from the one that introduces air in the axial direction from the upper end surface in the axial direction of the filtration member (see FIGS. 1 and 13 of Patent Document 1). The filtration area of the filter member can be increased or decreased by changing the axial dimension without changing the radial dimension (outer diameter and / or inner diameter) of the member.
In addition, since the filter is configured to flow air in the radial direction of the filter member, dust collected on one peripheral side, which is the surface on the air introduction side of the filter member, is obtained using the backflow of air. It can be easily peeled off. Therefore, the effect of separating dust due to the backflow of air can be improved as compared with a configuration in which the air flow is bent in the filtering member (see FIGS. 9 and 13 of Patent Document 1).
Therefore, it is possible to increase and decrease the filtration area of the filtration member without changing the radial dimension of the filtration member, while improving the dust peeling effect due to the backflow of air.
Also, the casing has a cylindrical shape surrounding at least a part of the periphery of the fuel filler opening opened obliquely upward of the inlet pipe of the fuel tank, and is fixed in a state of being fitted to the fuel filler. It is. Therefore, the oil filler opening of the inlet pipe can be protected from an impact during a collision using the casing.
In addition, the filtering member is arranged in a state of being spaced apart from the outer peripheral wall portion and the inner peripheral wall portion of the filtration chamber of the casing by a predetermined distance, whereby the filtration chamber is separated from the outer peripheral space portion and the inner peripheral space. The peripheral side facing the top side of the filter member is the air introduction side, the peripheral side facing the top side is the air outlet side, and the air introduced into the canister through the air introduction path is Dust in the air is collected on the peripheral side of the air introduction side of the filtration member by filtering with the filtration member, and dust collected by the backflow of air from the canister side is separated from the peripheral side of the filtration member It is good to set it as the structure made to let it fall on the internal peripheral surface of the surrounding wall part of the space part by the side of the filtration chamber.

  Further, according to the dust filter of the fuel vapor processing apparatus according to claim 2, the coarseness of the filter member has a gradient that roughens the upstream side in the air flow direction and fines the downstream side. It is. Therefore, dust can be collected in stages, and filtration performance can be improved. Moreover, the increase in the ventilation resistance of the filtration part can be suppressed by reducing the amount of dust collected in the fine filtration part on the downstream side. Therefore, it is possible to suppress an increase in ventilation resistance while improving the filtration performance.

Moreover, according to the dust filter of the evaporative fuel processing apparatus according to claim 3, the casing communicates with the space portion on the ground side of the filtration chamber and on the inner peripheral surface of the peripheral wall portion of the space portion on the ground side. A dust trap chamber is provided for storing dust falling.

  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, the evaporative fuel processing apparatus 10 uses evaporative fuel by an adsorbent 22 in a canister 20 provided in the middle of a purge line 18 that communicates a fuel tank 12 and an intake pipe 16 of an engine (internal combustion engine) 14. To adsorb. The purge valve 24 provided in the purge line 18 is opened / closed according to the operating state of the engine. Thereby, the evaporated fuel adsorbed by the adsorbent 22 in the canister 20 is introduced into the intake pipe 16 through the purge line 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. The inlet pipe 30 and the fuel tank 12 are communicated with each other by a breather line 35.

  The canister 20 prevents the evaporated fuel generated in the fuel tank 12 from being released into the atmosphere through the atmosphere introduction line 26 by adsorbing the evaporated fuel 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 line 18 using the intake pipe negative pressure when the purge valve 24 is open. At that time, air is introduced through the atmosphere introduction line 26. The air introduction line 26 alleviates pressure fluctuations generated in the fuel tank 12 by introducing air into the fuel tank 12 from the atmosphere 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 inlet 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 inlet 31. The dust filter 40 of the present embodiment communicates with the atmosphere side end portion of the atmosphere introduction line 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 line 26. By doing so, it is provided to remove dust in the atmosphere. 2 is a cross-sectional view showing the dust filter, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. 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 and a filtering member 44.
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 46, a semi-cylindrical outer peripheral wall portion 47 that is parallel to the outer peripheral side of the inner peripheral wall portion 46 at a predetermined interval, an inner peripheral wall portion 46, and an outer peripheral portion. A hollow space surrounded by both peripheral end wall portions 48 and 49 (see FIG. 2) closing both ends in the circumferential direction of the wall portion 47, the inner peripheral wall portion 46 and the outer peripheral wall portion 47, and both the peripheral end wall portions 48 and 49. An arc-shaped upper and lower end plate portions 50 and 51 (see FIG. 3) for closing both opening end surfaces in the axial direction (the front and back direction in FIG. 2), and a semi-cylindrical sealed internal space Forming.

  As shown in FIG. 3, the internal space of the casing 42 is separated from the upper filtration chamber 54 and the lower dust by a partition wall portion 52 that is parallel to the lower end plate portion 51 at a predetermined interval. It is partitioned into a trap chamber 55. The casing 42 has a coupling structure with a plurality of divided bodies, and is configured by coupling the plurality of divided bodies to each other such that the filtration member 44 is disposed in the filtration chamber 54. In addition, the casing 42 is fixed to the oil supply port 31 with appropriate fixing means such as screwing means and clip means (not shown) while being 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 FIG. 3). Therefore, when the dust filter 40 is mounted on the vehicle, as shown in FIG. 3, the filtration chamber 54 is disposed on the top side (upper side), and the dust trap chamber 55 is disposed on the ground side (lower side). At the same time, the filtering member 44 (described later) 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).

  As shown in FIG. 2, a first support piece 57 that protrudes radially outward and extends in the axial direction is formed on one end side (left end side in FIG. 2) of the inner peripheral wall portion 46 in the circumferential direction. . The distal end portion of the first support piece 57 extends to the radial intermediate portion of the filtration chamber 54. A second support piece 58 that protrudes inward in the radial direction and extends in the axial direction is formed on the other end side in the circumferential direction of the outer peripheral wall portion 47 (right end side in FIG. 2). The distal end portion of the second support piece 58 extends to the radial intermediate portion of the filtration chamber 54.

  The filter member 44 is formed by bending a filter material such as filter paper or nonwoven fabric into a pleated shape. The filtration member 44 is accommodated in the filtration chamber 54. One end portion (left end portion in FIG. 2) 44a in the circumferential direction of the filtering member 44 is joined in a state of being fitted to the first support piece 57. Further, the other end portion (right end portion in FIG. 2) 44 b in the circumferential direction of the filtering member 44 is joined in a state of being fitted to the second support piece 58. Moreover, the upper edge part of the filtration member 44 is joined to the said upper end plate part 50, and the lower end edge is joined to the said partition wall part 52 (refer FIG. 3). The inside of the filtration chamber 54 is partitioned into two space portions by the filtration member 44. Of the two space portions, the space portion on the outer peripheral side of the filtering member 44 is the space portion 60 on the air introduction side, and the space portion on the inner periphery side is the space portion 62 on the air outlet side (see FIG. 2 and FIG. 2). (See FIG. 3).

  An air opening 64 that opens the space 60 to the atmosphere is formed in the wall of the casing 42 facing the space 60 on the air introduction side (see FIG. 2). Thereby, air in the atmosphere is introduced into the space 60 on the air introduction side of the filtration chamber 54 through the atmosphere opening 64 (see arrow Y1 in FIG. 2). The air opening 64 can be set at any position as long as it is a wall portion facing the space portion 60 on the air introduction side in the casing 42.

  An air outlet 66 that opens the space 62 is formed in a wall portion facing the space 62 on the air outlet side of the casing 42 (see FIG. 2). The air outlet port 66 communicates with the atmosphere side end of the atmosphere introduction line 26 (see FIG. 1). As a result, the air in the space 62 on the air outlet side of the filtration chamber 54 flows out to the atmosphere introduction line 26 (see FIG. 1) through the air outlet 66 and is further introduced into the canister 20. The air outlet 66 can be set at an arbitrary position as long as it is a wall portion facing the space 62 on the air outlet side of the casing 42.

  As shown in FIG. 3, the partition wall 52 of the casing 42 is formed with a communication port 68 that allows the space 60 on the air introduction side of the filtration chamber 54 and the dust trap chamber 55 to communicate with each other. The communication port 68 is opened so as to contact the inner peripheral surface of the outer peripheral wall portion 47. The communication port 68 is formed at least in the vicinity of the lowermost part in the circumferential direction of the outer peripheral wall 47. The communication port 68 may be one opening hole that is continuous in the circumferential direction, or may be a plurality of opening holes that are intermittently formed in the circumferential direction. The communication port 68 corresponds to the “inlet portion of the dust trap chamber” in this specification.

  On the inner peripheral surface of the outer peripheral wall portion 47 in the dust trap chamber 55, a rib-like backflow prevention wall 70 that blocks the communication port 68 in a dam shape is formed. The backflow prevention wall 70 protrudes radially inward from near the lower side of the partition wall portion 52 and extends in the circumferential direction. Further, the backflow prevention wall 70 has a protruding height higher than the opening height of the communication port 68 and is inclined so as to be gently separated from the partition wall portion 52 toward the tip thereof. The backflow prevention wall 70 corresponds to “backflow prevention means” in this specification.

  In the dust filter 40, the air flows into the space 60 on the air introduction side through the atmosphere opening 64 (see FIG. 2) (see arrow Y1 in FIG. 2). The air is filtered by passing through the filter member 44 in the radial direction from the outer peripheral side to the inner peripheral side, and flows out to the space portion 62 on the air outlet side (see arrow Y2 in FIGS. 2 and 3). ). Further, the filtered air flows out through the air outlet 66 (see arrow Y3 in FIG. 2). The air is introduced into the canister 20 through the air introduction path 26 as shown in FIG.

  Further, dust is collected on the outer peripheral side of the filtering member 44 facing the space portion 60 on the air introduction side. Since the outer peripheral side of the filter member 44 is directed to the ground side in the vertical direction on the installation of the dust filter 40, the dust collected on the outer peripheral side is caused by gravity, vehicle vibration, positive pressure during refueling, etc. It peels and falls on the internal peripheral surface of the outer peripheral wall part 47 (refer arrow Y4 in FIG. 3). Further, dust is stored by dropping into the dust trap chamber 55 through the communication port 68 (see arrow Y5 in FIG. 3). At this time, the dust flows over the backflow prevention wall 70 and enters the lower space, thereby preventing or reducing the backflow of the dust (denoted by reference numeral D).

  Further, the dust filter 40 is provided on the atmosphere introduction path of the canister 20 (in this embodiment, the end portion on the atmosphere introduction side of the atmosphere introduction line 26) (see FIG. 1). As a result, dust is collected by the filtering member 44 (see FIGS. 2 and 3) when the canister 20 is under negative pressure, and the dust is peeled off or dropped from the filtering member 44 due to the positive pressure of the canister 20 ( (See arrow Y4 in FIG. 3). Therefore, it is possible to effectively collect dust by the filtering member 44 and peel off the dust from the filtering member 44. The path through which air flows in the dust filter 40 and the atmosphere introduction line 26 correspond to the “atmosphere introduction path” in this specification.

According to the dust filter 40 of the fuel vapor processing apparatus 10 described above, the air flowing through the atmosphere introduction line 26 is filtered by passing through the filtering member 44, and dust contained in the air is collected by the filtering member 44.
Further, since the filtration member 44 is formed in an arc shape in cross section, it is different from that in which air is introduced in the axial direction from the upper end surface of the filtration member 44 in the axial direction (see FIGS. 1 and 13 of Patent Document 1). The filtration area of the filter member 44 can be increased or decreased by changing the axial dimension without changing the radial dimension (outer diameter and / or inner diameter) of the filter member 44.
In addition, since the filter is configured to flow air in the radial direction of the filter member 44, dust collected on one peripheral side, that is, the outer peripheral side, which is the air introduction side surface of the filter member 44, is removed. It can be easily peeled off using a reverse flow. Therefore, as compared with a configuration in which the air flow is bent in the filtering member 44 (see FIGS. 9 and 13 of Patent Document 1), the dust peeling effect due to the backflow of air can be improved.
Therefore, it is possible to increase and decrease the filtration area of the filtration member 44 without changing the radial dimension of the filtration member 44, while improving the dust peeling effect due to the backflow of air.

  Moreover, the casing 42 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 such as a collision by using the casing 42. In addition, by changing the casing 42 into 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 almost the entire circumference, the oil supply of the inlet pipe 30 against an impact at the time of a collision or the like. The protection performance of the mouth 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.

  In addition, when the dust filter 40 is installed, a circumferential side that is directed to the ground side (lower side) of the filtering member 44 in the top-and-bottom direction, that is, the outer circumferential side is defined as an air introduction side. Therefore, by collecting dust on the peripheral side (outer peripheral side) of the air introduction side directed to the ground side in the top and bottom direction of the filter member 44, the dust is grounded due to gravity, vehicle vibration, positive pressure during refueling, and the like. Can be easily peeled off or dropped. This is effective for suppressing an increase in ventilation resistance of the filter member 44.

  In addition, the filtration member 44 is formed in an arc shape in cross section, and is filtered by flowing air in the radial direction from the outer peripheral side to the inner peripheral side of the filtration member 44 (in FIG. 2 and FIG. 3, the arrow Y2). reference.). That is, by setting a surface for collecting dust on the outer peripheral side of the filter member 44 formed in a circular arc shape in cross section, the area of the surface for collecting dust of the filter member 44 can be increased.

  Moreover, the dust peeled off from the filter member 44 is stored in the dust trap chamber 55 through the space 60 on the air introduction side (see FIG. 3). The backflow of dust stored in the dust trap chamber 55 is prevented or reduced by the backflow prevention wall 70. Therefore, it is possible to avoid the dust peeled off from the filtering member 44 from being accumulated in the space 60 on the air introduction side. For this reason, the raise of the ventilation resistance of the filtration member 44 can be suppressed.

  In addition, since the backflow prevention wall 70 (see FIG. 3) that blocks the communication port 68 of the partition wall portion 52, which is the entrance of the dust trap chamber 55, is a backflow prevention means, the backflow prevention means has a simple configuration. can do.

[Example 2]
A second embodiment of the present invention will be described. Since the present embodiment is a modification of the dust filter 40 in the first embodiment, the changes will be described in detail, and a duplicate description will be omitted. 4 is a sectional view showing the dust filter, and FIG. 5 is a sectional view taken along line VV in FIG.
In the present embodiment, the filtering member 43 is provided on the surface side of the filtering member 44 of the dust filter 40 in the first embodiment, that is, on the outer peripheral side. For convenience of explanation, both the filtering members 43 and 44 are collectively referred to as “filtering member 45”, the filtering member 43 is referred to as “upstream filtering unit 43”, and the filtering member 44 is referred to as “downstream filtering unit”. 44 ".

  The upstream filtration part 43 is formed in a sheet shape from a filtration material made of a foaming material such as urethane having air permeability, and is joined to the outer peripheral side of the downstream filtration part 44 in a laminated manner. Thus, the downstream filtration unit 44 is a main filtration unit and has an eye that can appropriately collect dust contained in the air passing through the casing 42. Further, the upstream filtration unit 43 is a sub-filtration unit, and collects larger dust out of dust that is coarser than the eyes of the downstream filtration unit 44, that is, dust contained in the air passing through the casing 42. Has a possible eye.

  In the dust filter 40, the air (see arrow Y1 in FIG. 4) that flows into the space 60 on the air introduction side moves the upstream filtration unit 43 and the downstream filtration unit 44 from the outer circumferential side to the inner circumferential side. It is filtered by passing in the radial direction and flows out to the space 62 on the air outlet side (see arrow Y2 in FIG. 4). At this time, a large amount of dust contained in the air is collected by the upstream filtering unit 43. Then, the small dust contained in the air is collected by the downstream filtering unit 44.

  Further, dust is collected on the outer peripheral side of the upstream filtration unit 43 facing the air introduction side space 60. Since the outer peripheral side of the filter part 43 is directed to the ground side (lower side) in the vertical direction on the installation of the dust filter 40, the dust collected on the outer peripheral side is collected during gravity, vehicle vibration, and oiling. It peels off by positive pressure etc. and falls on the inner peripheral surface of the outer peripheral wall part 47 (refer arrow Y4 in FIG. 5). Further, dust is stored by dropping into the dust trap chamber 55 through the communication port 68 (see arrow Y5 in FIG. 3). At this time, the dust flows over the backflow prevention wall 70 and enters the lower space, thereby preventing or reducing the backflow of the dust (denoted by reference numeral D).

The same functions and effects as those of the first embodiment can be obtained by the dust filter 40 of the evaporated fuel processing apparatus 10 described above.
Moreover, the coarseness of the filtration parts 43 and 44 of the filtration member 45 has a gradient which makes the upstream filtration part 43 rough in the air flow direction and makes the downstream filtration part 44 fine. Therefore, dust can be collected in stages, and filtration performance can be improved. Further, since the amount of dust collected by the fine filtration unit 44 on the downstream side is reduced, an increase in ventilation resistance of the filtration unit 44 can be suppressed. Therefore, it is possible to suppress an increase in ventilation resistance while improving the filtration performance.

  Further, in the installation of the dust filter 40, the peripheral side, that is, the outer peripheral side of the upstream filtering portion 43 directed to the ground side (lower side) of the filtering member 45 in the vertical direction is defined as the air introduction side (see FIGS. 4 and 5). .) Therefore, by collecting dust on the air introduction side peripheral side (outer peripheral side) of the upstream filtration unit 43 directed to the ground side of the filter member 45 in the vertical direction, gravity, vehicle vibration, and positive pressure at the time of refueling Etc., dust can be easily dropped to the ground side. This is effective in suppressing an increase in ventilation resistance of the filter member 45.

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 filter member (downstream filter part) 44 may be a filter material such as a foam material such as urethane, in addition to a filter material such as filter paper and nonwoven fabric.

  The filter member (upstream filter part) 43 may be made of a filter material such as filter paper or nonwoven fabric, in addition to a filter material made of foam such as urethane. In addition, the upstream filtering unit 43 and the downstream filtering unit 44 of the filtering member 45 may be made of different filtering materials, and not only different filtering members but also the same filtering material. You can also. The coarseness of the filter member 45 only needs to have a gradient that is rough on the upstream side in the air flow direction and fine on the downstream side, and the filtration of the two-layer filtration parts 43, 44 or three or more layers is sufficient. In addition to having a stepwise gradient depending on the part, it can also be changed continuously. Further, the upstream filtration unit 43 and / or the downstream filtration unit 44 are not limited to a single layer, but can be formed into two or three layers. Further, the downstream filtration unit 44 and the upstream filtration unit 43 may be arranged at a predetermined interval. Moreover, a filtration member can also be comprised in three or more layers by adding another filtration member to the filtration part 43 of an upstream, and the filtration part 44 of a downstream.

As the backflow prevention means, in addition to the fixed backflow prevention wall 70 of the above embodiment, a movable backflow prevention wall that is opened and closed using a rubber-like elastic material, a spring material, etc., a check valve such as a flap valve Etc. can also be considered. In the above embodiment, the outer peripheral side of the filtering member 44 or the filtering member 45 is the air introduction side and the inner peripheral side of the filtering member 44 or the filtering member 45 is the air outlet side. The inner peripheral side of the member 45 may be the air introduction side, and the outer peripheral side of the filtering member 44 or the filtering member 45 may be the air outlet side. Further , the dust trap chamber 55, the backflow prevention wall 70, 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 sectional drawing which shows the dust filter concerning Example 2 of this invention. FIG. 5 is a cross-sectional view taken along line VV in FIG. 4.

Explanation of symbols

10 Evaporative Fuel Treatment Device 12 Fuel Tank 26 Air Introduction Line (Atmosphere Introduction Route)
30 Inlet pipe 31 Refueling port 40 Dust filter 42 Casing 43 Filtration member (upstream filtration section)
44 Filtration member (downstream filtration section)
45 Filtration member

Claims (3)

Evaporated fuel which is provided on an air introduction path leading to a canister in an evaporative fuel processing apparatus of a vehicle and which stores a filter member for filtering air introduced into the canister through the air introduction path in a filter chamber in a casing. A dust filter of a processing device,
The filtration member is formed in a circular arc shape, and is configured to flow by flowing air in the radial direction of the filtration member ,
The casing has a cylindrical shape surrounding at least a part of the periphery of the fuel filler opening opened obliquely upward of the inlet pipe of the fuel tank, and is fixed in a state of being fitted to the fuel filler;
The filtration member is disposed in a state of being spaced from the outer peripheral wall portion and the inner peripheral wall portion of the filtration chamber of the casing by a predetermined distance so that the inner space of the filtration chamber is separated from the outer peripheral space portion and the inner peripheral wall portion. Divided into a space part on the side,
The circumferential side directed to the ground side in the top-to-bottom direction of the filtering member is an air introduction side, and the circumferential side directed to the top side is an air outlet side,
The air introduced into the canister through the atmosphere introduction path is filtered by the filter member, whereby dust in the air is collected on the air introduction side of the filter member, and the air from the canister side is collected. The evaporated fuel treatment is characterized in that the collected dust is separated from the peripheral side of the filter member by the backflow of the filter member and dropped onto the inner peripheral surface of the peripheral wall portion of the space portion on the ground side of the filter chamber. Equipment dust filter. It is a dust filter of the evaporative fuel processing apparatus according to claim 1,
The dust filter for an evaporative fuel processing apparatus, wherein the coarseness of the filter member has a gradient that roughens the upstream side in the air flow direction and fines the downstream side. It is a dust filter of the evaporative fuel processing device according to claim 1 or 2,
The casing is provided with a dust trap chamber for storing the dust falling on the inner peripheral surface of the peripheral wall portion of the ground space and communicating with the ground space of the filtration chamber. A dust filter for a fuel vapor processing apparatus.

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