JP2008106610A - Evaporated fuel treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the deterioration of emission due to purge failure in the vicinity of the center of an adsorption layer. <P>SOLUTION: The evaporated fuel treatment device 1 has a first fuel adsorption part 2 which includes a plurality of adsorption layers and a second fuel adsorption part 3 which accommodates and holds a honeycomb activated carbon 11. The first fuel adsorption part 2 includes a charge port 7 and a purge port 8. The second fuel adsorption part 3 includes an atmospheric port 14 communicating to the atmosphere, and is equipped with a honeycomb activated carbon accommodation part 18 and an atmosphere introduction side end 13 having the atmospheric port 14. A baffle plate 38 (agitation means) for agitating air introduced in a honeycomb activated carbon accommodation part 18 is arranged in the atmosphere introduction side end 13. Thus, a flow velocity distribution in a cross-section direction of the honeycomb activated carbon 11 is substantially uniform at purge so that the honeycomb activated carbon 11 can be effectively purged even though a purge air amount is small. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an evaporated fuel processing apparatus that adsorbs fuel evaporated from a fuel tank of an automobile and burns the fuel when the engine is operating.

  In an automobile using gasoline as fuel, a canister is generally used as an evaporative fuel processing device in order to suppress the evaporative fuel in the fuel tank from being released to the atmosphere.

  The canister purges the interior of the canister with the air introduced from the canister air port by adsorbing the evaporated fuel generated from the fuel tank when the vehicle is stopped to the adsorbent made of activated carbon and sucking air through the canister when the engine is running. The adsorbed fuel vapor is desorbed and burned in the engine. Then, by this purging, the adsorption performance of the adsorbent can be restored, and the evaporated fuel can be adsorbed favorably repeatedly.

  By the way, in recent years, environmental regulations have become stricter, and canisters are required to improve performance. In order to improve the performance of the canister, it is effective to improve the desorption efficiency of the evaporated fuel by purging. As means for improving the desorption efficiency, it is known to increase the ratio L / D between the length L of the activated carbon layer and the effective sectional diameter D of the activated carbon layer.

  Especially in the activated carbon layer on the atmosphere port side, the value of L / D is increased and the volume of the activated carbon layer is decreased to increase the purge air amount per unit volume (the amount of air for purging the canister). Thus, it is known that the desorption efficiency of this portion can be improved and the evaporated fuel that cannot be captured by the activated carbon layer on the upstream side (purge port side and charge port side) can be efficiently captured (patent) Reference 1).

  On the other hand, it has become difficult to secure purge air for purging the canister. For example, in a vehicle equipped with a hybrid engine, when the motor is driven, the engine is not driven and intake is not performed. Therefore, it is very difficult to purge the canister during this time.

  Thus, when the purge air amount is insufficient, the above-mentioned L / D value is increased in the activated carbon layer on the atmosphere port side to improve the canister performance, thereby responding to the shortage of the purge air amount. However, there is a problem that the ventilation resistance increases as the value of L / D increases.

Therefore, Patent Document 2 discloses a technique that uses honeycomb activated carbon instead of providing an activated carbon layer on the atmosphere port side. As described above, when the honeycomb activated carbon is used, the L / D value can be increased on the atmosphere port side, and the increase in the ventilation resistance can be reduced.
JP 2004-1000069 A Japanese Patent Laid-Open No. 10-37812

  By the way, even if honeycomb activated carbon is used, the ventilation resistance is not zero. In order to reduce the ventilation resistance while ensuring a desired L / D value, it is necessary to increase the effective cross-sectional diameter D of the honeycomb activated carbon. However, when the effective sectional diameter D of the honeycomb activated carbon is increased, the flow near the center of the cross section is good, but the air is less likely to flow toward the outer peripheral side of the cross section. That is, there is a possibility that the purge is insufficient at the portion where the air flow is bad, and the evaporated fuel remains and worsens the emission.

  Accordingly, in the evaporated fuel processing apparatus according to claim 1 of the present invention, the first fuel adsorption in which the adsorption layer made of the adsorbent for adsorbing and desorbing the evaporated fuel is arranged in the first flow path formed inside. And a second fuel adsorbing portion in which an adsorbing layer made of an adsorbent that adsorbs and desorbs the evaporated fuel is disposed in a second flow path formed inside, the first fuel adsorbing portion, A charge port connected to the fuel tank and a purge port connected to the intake system of the engine are provided at a position on one end side of the first flow path, and the second fuel adsorbing portion is connected to the second flow path. The first fuel adsorbing portion and the first fuel adsorbing portion are arranged so that the other end side of the first flow path is continuous with one end side of the second flow path. In the evaporative fuel processing apparatus connected to the second fuel adsorbing unit, the second fuel adsorbing unit is an adsorbent. A honeycomb activated carbon housing portion in which the honeycomb activated carbon is housed and held, and an air introduction side end portion having an air port, and the air introduction side end portion is introduced into the honeycomb activated carbon housing portion via the air port. Stirring means for stirring the air is disposed. As a result, the air that has flowed into the second fuel adsorbing portion at the time of purging flows into the honeycomb activated carbon after being stirred by the stirring means, and therefore flows not only near the center of the cross section of the honeycomb activated carbon but also on the outer peripheral portion of the cross section . Therefore, the air flowing in from the atmospheric port flows through the entire cross section of the honeycomb activated carbon.

  According to a second aspect of the present invention, in the evaporative fuel processing apparatus according to the first aspect, the stirring means is a baffle plate disposed so as to face the air inlet of the air port.

  As a result, the air flowing in from the atmosphere introduction port collides with the baffle plate, and then changes the direction by approximately 90 ° toward the outer peripheral side of the atmosphere introduction side end. That is, the baffle plate stirs the air flow that flows from the air inlet and tries to go straight.

  According to a third aspect of the present invention, there is provided the evaporative fuel processing apparatus according to the first or second aspect, wherein the second fuel adsorbing portion has a passage cross-sectional area at the end portion on the atmosphere introduction side where the passage of the honeycomb activated carbon housing portion is cut off. It is formed so as to be larger than the area, and a step is formed inside the second fuel adsorbing portion at a boundary portion between the air introduction side end portion and the honeycomb activated carbon housing portion. Thereby, the air introduced at the time of purging and colliding with the baffle plate changes the flow direction to the outer peripheral side of the atmospheric introduction side end and collides with the inner peripheral surface of the atmospheric introduction side end to become the downstream side. Dust contained in the agitated air is captured at the step at the boundary between the air introduction side end and the honeycomb activated carbon housing part.

  According to the present invention, the air flowing into the second fuel adsorbing portion at the time of purging is stirred by the stirring means, and the flow velocity distribution in the cross-sectional direction of the honeycomb activated carbon becomes substantially uniform. Activated carbon can be efficiently purged. In other words, the honeycomb activated carbon located closest to the atmosphere in the adsorption layer can obtain good adsorption performance even with a small purge air amount. For this reason, it is possible to prevent the emission from deteriorating due to the residue of the evaporated fuel on the honeycomb activated carbon.

  According to the second aspect of the present invention, the air flowing in from the atmospheric port is surely changed in direction by about 90 ° by the baffle plate, flows toward the outer peripheral side of the atmospheric introduction side end, and the incoming air is stirred. The

  According to the third aspect of the present invention, when the agitated air flows into the honeycomb activated carbon accommodating portion, the agitated air is stepped at the boundary portion between the air introduction side end and the honeycomb activated carbon accommodating portion. Inside dust can be captured.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram showing the overall configuration of the evaporative fuel processing apparatus 1, and FIG. 2 is an explanatory diagram of a second fuel adsorption unit in the evaporative fuel processing apparatus 1. 3 and 4 are explanatory views of the air introduction side end 13 which will be described later.

  As shown in FIG. 1, the evaporative fuel processing apparatus 1 is roughly configured by a first fuel adsorption unit 2 and a second fuel adsorption unit 3 connected to the first fuel adsorption unit 2 via a hose 4. Yes.

  In the present embodiment, the first casing 5 of the first fuel adsorbing unit 2 and the second casing 6 of the second fuel adsorbing unit 3 are separated, and the relatively large first fuel adsorbing unit 2 A second casing 6 of the second fuel adsorbing portion 3 is externally attached to the first casing 5.

  The first fuel adsorbing portion 2 has a first flow path (not shown) that is a single flow path formed therein, and a plurality of adsorbed layers that adsorb and desorb evaporated fuel in the first flow path. (Not shown) is arranged. These adsorption layers are made of an adsorbent made of activated carbon or the like.

  The first fuel adsorbing section 2 has a charge port 7 connected to a fuel tank (not shown) and a purge port 8 connected to the intake system of the engine at a position on one end side of the first flow path. In addition, the first intermediate port 9 connected to the second fuel adsorbing portion 3 via the hose 4 is provided at a position on the other end side of the first flow path. In the present embodiment, the first flow path is folded back in the first casing 5, and the charge port 7, purge port 8, and first intermediate port 9 of the first fuel adsorbing unit 2 are connected to the first casing. 5 is provided on one end side (upper side in FIG. 1).

  As shown in FIG. 2, the second fuel adsorbing unit 3 has a second flow path 10 that is a single flow path formed therein, and adsorbs and desorbs evaporated fuel in the second flow path 10. A columnar honeycomb activated carbon 11 is disposed. The second fuel adsorbing unit 3 has a second intermediate port 12 connected to the first intermediate port 9 of the first fuel adsorbing unit 2 through the hose 4 at a position on one end side of the second flow path 10. And an atmosphere port 14 communicating with the atmosphere at the atmosphere introduction side end 13 which is the other end side of the second flow path 10.

  The second casing 6 of the second fuel adsorbing portion 3 includes a main case member 15 having a substantially constant thickness and a substantially stepped cylindrical shape, and the other end side of the main case member 15, that is, the second casing 6. A substantially bottomed cylindrical cover member 16 assembled to the opening on the other end side (upper side in FIGS. 1 and 2), and an atmospheric port 14 is formed in the cover member 16.

  The main case member 15 has a cylindrical second intermediate port 12, a cylindrical second intermediate port base 17, and a cylinder in which the honeycomb activated carbon 11 is accommodated and held in order from one end side (the lower side in FIGS. 1 and 2). A cylindrical main case member other end portion 19 that forms the atmosphere introduction side end portion 13 together with the honeycomb activated carbon housing portion 18 and the cover member 16 is formed. The main case member 15 is formed so that the respective axes of the second intermediate port 12, the second intermediate port base portion 17, the honeycomb activated carbon housing portion 18, and the main case member other end portion 19 coincide with each other. The second intermediate port base portion 17 is formed to have a larger diameter than the second intermediate port 12, the honeycomb activated carbon housing portion 18 is formed to have a larger diameter than the second intermediate port base portion 17, and the main case member other end portion 19 is The diameter is larger than that of the honeycomb activated carbon accommodating portion 18.

  As shown in FIGS. 1 to 4, a groove 20 is formed in the other end portion 19 of the main case member, and one end side of the main case member 15 from the groove 20, that is, one end side of the second casing 6. A bead 21 protrudes from the inner peripheral surface (the lower side in FIGS. 1 and 2).

  The inner diameter of the honeycomb activated carbon accommodating portion 18 is larger than the outer diameter of the honeycomb activated carbon 11. On the other hand, the honeycomb activated carbon 11 is wound with a first screen member 22 made of a rectangular plate-shaped nonwoven fabric, and at one end 11a of the honeycomb activated carbon 11 (the lower end in FIGS. 1 and 2), A cylindrical seal member 23 is attached. The seal member 23 is formed in a stepped shape so that the inner peripheral surface thereof engages with the end surface of the one end portion 11a of the honeycomb activated carbon 11, and the outer peripheral surface that is in close contact with the inner peripheral surface of the honeycomb activated carbon accommodating portion 18 has a pleated shape. Is formed.

  The first screen member 22 is in close contact with the inner peripheral surface of the honeycomb activated carbon housing portion 18 to regulate the radial movement of the honeycomb activated carbon 11 within the honeycomb activated carbon housing portion 18 and to impact the honeycomb activated carbon 11 from the outside. It functions as a cushioning material.

  The seal member 23 seals between the outer peripheral surface of the honeycomb activated carbon 11 and the inner peripheral surface of the honeycomb activated carbon accommodating portion 18 to position and fix the honeycomb activated carbon 11, and one end portion 23 a (the lower side in FIGS. 1 and 2). Is in contact with a step 24 formed at a boundary portion between the honeycomb activated carbon accommodating portion 18 and the second intermediate port base portion 17. The seal member 23 regulates the movement of the honeycomb activated carbon 11 in the axial direction (vertical direction in FIGS. 1 and 2) of the honeycomb activated carbon 11 together with the second screen member 25 described later.

  The second screen member 25 made of urethane has a disk shape, and is slightly compressed in the axial direction of the main case member 15 into the opening on the other end side (the upper side in FIGS. 1 and 2) of the honeycomb activated carbon housing portion 18. It is assembled in a state. The outer peripheral edge of the second screen member 25 is in close contact with the inner peripheral surface of the honeycomb activated carbon housing portion 18.

  At the boundary portion between the honeycomb activated carbon housing portion 18 and the main case member other end portion 19, a step 26 is formed over the entire circumference in the circumferential direction of the main case member other end portion 19 (honeycomb activated carbon housing portion 18). Yes.

  Further, on the inner side of the air introduction side end portion 13, on the other end side (upper side in FIGS. 1 and 2) of the main case member 15 of the step 26, on the entire circumference in the circumferential direction of the main case member other end portion 19. As a result, a step 42 is formed. The step 42 will be described later.

  As shown in FIGS. 2 to 4, the holding member 27 includes an annular base 28 that contacts the step 26, a rib 29 that extends radially from the center of the base 28 and is connected to the inner peripheral surface of the base 28, and a base And a cylindrical outer peripheral wall portion 30 rising from the outer peripheral edge of 28.

  And the front-end | tip of the outer peripheral wall part 30 is abutted by the bead 21 formed in the perimeter of the inner peripheral surface of the main case member other end part 19, and the position is being fixed. Here, since the second screen member 25 is assembled in the opening on the other end side (the upper side in FIGS. 1 and 2) of the honeycomb activated carbon accommodating portion 18 in a slightly compressed state, the pressing member 27 is the main case. The member 15 is fixed to the main case member 15 by being biased toward the other end side (the upper side in FIGS. 1 and 2).

  As shown in FIGS. 2 to 4, the cover member 16 includes a bottom wall 31 serving as the other end surface of the second fuel adsorbing portion 3, a cylindrical peripheral wall 32 having a base end connected to the bottom wall 31, and a peripheral wall And four projecting pieces 33 projecting along the axial direction of the cover member 16 from the tip of 32.

  In the center of the bottom wall 31, a circular atmospheric inlet 34 smaller than the passage cross-sectional area of the other end portion 11 b of the honeycomb activated carbon 11 is formed. A cylindrical air inlet peripheral wall 35 extending toward the lower side in FIG. 2 is connected to the air inlet 34. The atmosphere port 14 is constituted by the atmosphere introduction port peripheral wall 35 and the atmosphere introduction port 34.

  At the front end 35a of the atmosphere introduction port peripheral wall 35, four elongated extension walls 36 extending downward in FIG. 2 are formed. These four extension walls 36 are spaced apart from each other by a predetermined interval along the circumferential direction of the atmosphere introduction peripheral wall 35, and a gap 37 is formed between the adjacent extension walls 36 and 36. Yes. A disc-shaped baffle plate 38 having a diameter substantially the same as that of the air introduction port 34 is connected to the tips of these four extension walls 36 in substantially parallel to the bottom wall 31. The baffle plate 38 corresponds to a stirring means, and is arranged so as to oppose the air inlet 34 and block the flow of air introduced from the air inlet 34. The air introduced from the atmosphere introduction port 34 changes the flow direction by approximately 90 ° by colliding with the baffle plate 38, passes through the gap 37 and enters the inside of the cover member 16, that is, the inside of the atmosphere introduction side end portion 13. be introduced.

  The peripheral wall 32 is formed with claws 39 projecting outward at four locations on the circumference of the outer peripheral surface and grooves 40 on the entire circumference. The claw 39 is fitted into the four groove portions 20 formed on the outer peripheral surface of the other end portion 19 of the main case member by snap fitting, and thereby the cover member 16 is fixed to the other end portion 19 of the main case member. Has been. Further, an O-ring 41 is disposed in the groove 40, and the space between the cover member 16 and the main case member other end portion 19 is sealed.

  The protruding piece 33 is set so that the tip thereof is positioned in the vicinity of the base portion 28 of the pressing member 27, and a slight gap is set between the protruding piece 33 and the base portion 28. Therefore, even when the front end of the outer peripheral wall portion 30 is disengaged from the bead 21, the pressing member 27 is not inclined greatly because the movement is restricted by the protruding pieces 33.

  The step portion 42 is formed from a substantially donut-shaped space located on the outer peripheral side of the inner peripheral surface of the honeycomb activated carbon housing portion 18 in the inside of the atmosphere introduction side end portion 13. In other words, the step portion 42 is formed from a donut-shaped space sandwiched between the outer peripheral surface 33 a of the protruding piece 33 of the cover member 16 and the inner peripheral surface 19 a of the other end portion 19 of the main case member. When the air flowing in from the atmospheric port 14 is changed in direction by approximately 90 ° by the baffle plate 38 and flows into the inner peripheral side of the atmospheric introduction side end portion 13 while being stirred, it is formed between the adjacent protruding pieces 33 and 33. Through the gap 43, the stepped portion 42 is reached, and the dust contained in the air is captured by the stepped portion 42 and the stepped portion 26.

  In the step portion 42, dust contained in the air is captured mainly at a portion sandwiched between the outer peripheral surface 33 a of the protruding piece 33 and the inner peripheral surface 19 a of the main case member other end portion 19. In particular, when the axis of the second fuel adsorbing portion 3 is installed horizontally, dust can be captured in a region serving as a bottom surface of the stepped portion 42 that is a donut-shaped space. In this case, dust can be captured for a long time.

  In the present embodiment, the diameters of the air introduction port 35 and the baffle plate 38 are set to about half of the cross-sectional diameter of the other end portion 11 b of the honeycomb activated carbon 11. The distance from the air inlet 34 to the baffle plate 38 along the axial direction of the cover member 16 is set to about 20 mm, and the distance from the baffle plate 38 to the holding member 27 along the axial direction of the cover member 16 is set to about 40 mm. Has been.

  In the evaporative fuel processing apparatus 1 configured as described above, evaporative fuel generated from the fuel tank is introduced into the first fuel adsorbing unit 2 via the charge port 7 when the vehicle is stopped, and the first fuel adsorbing unit 2 The plurality of activated carbon layers and the honeycomb activated carbon 11 in the second fuel adsorption unit 3 are adsorbed. The evaporative fuel is mainly composed of a mixture of a hydrocarbon (hereinafter referred to as HC) gas and air. The HC is composed of a plurality of activated carbon layers in the first fuel adsorbing unit 2 and the second fuel adsorbing unit 3. Adsorbed by the honeycomb activated carbon 11, the air passes through the plurality of activated carbon layers in the first fuel adsorption unit 2 and the honeycomb activated carbon 11 in the second fuel adsorption unit 3 and is released into the atmosphere.

  On the other hand, when the engine is in operation, the negative suction pressure of the engine acts on the purge port 8, and the atmosphere flows into the second fuel adsorbing unit 3 from the atmospheric port 14, and enters the honeycomb activated carbon 11 and the first fuel adsorbing unit 2. A plurality of activated carbon layers are sequentially passed through and sucked into the engine. At this time, the HC adsorbed by the activated carbon 11 in the honeycomb activated carbon 11 and the first fuel adsorbing portion 2 is purged. The desorption of HC moves from the honeycomb activated carbon 11 to the activated carbon layer in the first fuel adsorbing portion 2, and the desorbed HC passes through the purge port 8 and is introduced into the intake system of the engine and burns in the engine. Used for The adsorption capability of the activated carbon layers in the first fuel adsorption unit 2 and the honeycomb activated carbon 11 in the second fuel adsorption unit 3 is regenerated by such purging.

  During such a purge, the air introduced from the atmosphere introduction port 34 collides with the baffle plate 38 and changes the direction of the flow to the outer peripheral side of the atmosphere introduction side end portion 13 to change the direction to approximately 90 °. After colliding with the inner peripheral surface of the introduction side end portion 13, it flows toward the honeycomb activated carbon accommodating portion 18. That is, the air flowing into the second fuel adsorbing unit 3 from the atmosphere introduction port 34 is agitated by colliding with the baffle plate 38. Therefore, the air introduced into the second fuel adsorbing portion 3 from the atmosphere introduction port 34 flows not only near the center of the cross section of the honeycomb activated carbon 38 but also on the outer peripheral side portion of the cross section. Accordingly, since the flow velocity distribution in the cross-sectional direction of the honeycomb activated carbon 11 of the air flowing into the second fuel adsorbing portion 3 at the time of purging becomes substantially uniform, the honeycomb activated carbon 11 is efficiently purged even with a small purge air amount. It becomes possible to do. That is, the honeycomb activated carbon 11 located on the atmosphere side can obtain good adsorption performance even with a small purge air amount. For this reason, it is possible to prevent the emission from deteriorating due to HC remaining in the honeycomb activated carbon 11.

  Further, when purging, the air that collides with the baffle plate 38 and flows into the inner peripheral side of the atmospheric introduction side end 13 is directed to the outer peripheral side of the atmospheric introduction side end 13. , 33 reaches the stepped portion 42 through the gap 43 formed between them and collides with the inner peripheral surface 19a of the other end portion 19 of the main case member. Therefore, in the step portion 42 that is a donut-shaped space, dust contained in the air is captured mainly at a portion sandwiched between the outer peripheral surface 33a of the protruding piece 33 and the inner peripheral surface 19a of the other end portion 19 of the main case member. can do.

  The dust contained in the air can also be captured at the step 26.

  In the above-described embodiment, the baffle plate 38 is used as the stirring means. However, the stirring means is not limited to the baffle plate 38 and, for example, a circular shape having an inner diameter substantially the same as the inner diameter of the other end portion 19 of the main case member. It is also possible to use a circular perforated plate having many through holes in the plate member as the stirring means. When the circular perforated plate is applied to the fuel vapor processing apparatus 1 of the above-described embodiment, the distance along the axial direction of the cover member 16 from the circular perforated plate to the pressing member 27 is set to about 20 mm. Thus, it is possible to obtain the same operational effects as when the above-described baffle plate 38 is used as the stirring means.

Explanatory drawing which shows the whole structure of the evaporative fuel processing apparatus which concerns on this invention. Explanatory drawing of the 2nd fuel adsorption | suction part of the evaporative fuel processing apparatus which concerns on this invention. Explanatory drawing of the 2nd fuel adsorption | suction part of the evaporative fuel processing apparatus which concerns on this invention. Explanatory drawing of the 2nd fuel adsorption | suction part of the evaporative fuel processing apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Evaporative fuel processing apparatus 2 ... 1st fuel adsorption | suction part 3 ... 2nd fuel adsorption | suction part 11 ... Honeycomb activated carbon 13 ... Atmosphere introduction side edge part 14 ... Atmospheric port 18 ... Honeycomb activated carbon accommodating part 38 ... Baffle plate (stirring means)

Claims (3)

A first fuel adsorbing portion in which an adsorbing layer made of an adsorbent that adsorbs and desorbs evaporated fuel is disposed in a first flow path formed inside;
A second fuel adsorbing portion in which an adsorbing layer made of an adsorbent that adsorbs and desorbs evaporated fuel is disposed in a second flow path formed inside,
The first fuel adsorbing portion has a charge port connected to a fuel tank and a purge port connected to an intake system of the engine at a position on one end side of the first flow path. The part has an atmospheric port communicating with the atmosphere at a position on the other end side of the second flow path,
In the evaporated fuel processing apparatus in which the first fuel adsorbing unit and the second fuel adsorbing unit are connected such that the other end side of the first channel is continuous with one end side of the second channel.
The second fuel adsorbing portion includes a honeycomb activated carbon accommodating portion in which honeycomb activated carbon as an adsorbent is accommodated and an atmosphere introduction side end portion having an atmosphere port,
An evaporative fuel processing apparatus, wherein an agitation means for agitating air introduced into the honeycomb activated carbon housing part via the atmosphere port is disposed at the atmosphere introduction side end.   2. The evaporative fuel processing apparatus according to claim 1, wherein the stirring means is a baffle plate disposed so as to face the atmosphere inlet of the atmosphere port.   The second fuel adsorbing portion is formed so that a passage cross-sectional area of the end portion on the air introduction side is larger than a passage cross-sectional area of the honeycomb activated carbon housing portion, and the air introduction side is disposed inside the second fuel adsorbing portion. The evaporative fuel processing device according to claim 2, wherein a step is formed at a boundary portion between the end portion and the honeycomb activated carbon housing portion.

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