JP2008202604A - Evaporative fuel handling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily change the value of a ratio L/D between the length L of an adsorbing material layer and an effective cross sectional diameter D in the whole of a device without changing the design of the whole of a casing. <P>SOLUTION: The casing 20 is provided with a charge port 21, a purge port 22, and an atmospheric air port 23, and the inside of the casing 20 is partitioned to a first filling chamber 24 and a second filling chamber 25, being communicated with each other through a connection path 26. An absorbing material cartridge 32 having a cross sectional area smaller than the inside cross section of the second charge chamber 25 is installed in an end of the second charge chamber 26 on a port 23 side thereof so as to form double-wall structure. The second filling chamber 25 including the inside of the cartridge 32 and the first filling chamber 24 are filled with activated carbon, while a non-filling space R is secured on the peripheral side of the cartridge 32. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The invention of this application 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.

  As this type of evaporative fuel processing apparatus, one as shown in FIG. 7 has been devised (see Patent Document 1).

  In this fuel vapor processing apparatus, a casing 1 is provided with a charge port 3 connected to a fuel tank 2, a purge port 6 connected to an intake manifold 5 of an engine 4, and an atmospheric port 7 connected to the atmosphere. Evaporated fuel is introduced into the casing 1 from the charge port 3 when the engine 4 is stopped. The casing 1 is filled with an adsorbent 8 such as activated carbon, and the fuel component in the fuel vapor is adsorbed by the adsorbent 8. The gas from which the fuel component is adsorbed and removed by the adsorbent 8 is released to the atmosphere through the atmosphere port 7. When the engine is operated from this state, the fuel component in the adsorbent 8 is sucked into the intake side of the engine 4 from the purge port 6, and the fuel is used for combustion of the engine 4 and is introduced through the atmospheric port 7. The adsorbent 8 is purged by the atmospheric air.

The inside of the casing 1 is partitioned by a partition wall 9 into a first filling chamber 10 that communicates with the charge port 3 and the purge port 6 and a second filling chamber 11 that communicates with the atmospheric port 7. , 11 communicate with each other through a connection path 12, and a substantially U-shaped passage is formed in the casing 1. The first filling chamber 10 is divided into front and rear by filters 13 and 14 and filled with the adsorbent 8 inside. The second filling chamber 11 is further divided into two chambers by filters 15, 16 and 17. Each of them is filled with an adsorbent 8. Therefore, the evaporated fuel introduced into the casing 1 through the charge port 3 is mainly adsorbed by the adsorbent 8 in the first filling chamber 10, and the remaining portion passes through the connection path 12 and adsorbent in the second filling chamber 11. 8 is adsorbed.
JP 2002-30998 A JP-A-5-280435

  By the way, the evaporative fuel treatment device is provided for the purpose of reducing the atmospheric emission of the evaporated fuel in the fuel tank. However, in recent years, the atmospheric emission regulation of the evaporated fuel has become stricter and the atmospheric emission amount of the evaporated fuel has been further increased. There is a demand for even less. Further, it is known that increasing the ratio L / D between the length L of the adsorbent layer and the effective cross-sectional diameter D is effective in reducing the atmospheric emission of evaporated fuel. Devices are being studied to increase the value.

  In the conventional evaporative fuel processing apparatus, it has been studied to increase the L / D. However, in order to increase the L / D, the entire casing 1 of the apparatus must be redesigned. An increase in manufacturing costs cannot be avoided.

  Currently, there is a requirement to create a plurality of specifications with different L / D values. To meet this requirement, it is necessary to prepare a plurality of facilities for separately creating a casing, and the production efficiency is reduced. There is concern about the decline.

  Furthermore, as described in Patent Document 2, there is also proposed a porous partition wall filled with a polymer absorbent material in the tank on the upstream side of the activated carbon layer in the charge direction. The intended purpose cannot be achieved.

  Therefore, the invention of this application makes it possible to easily change the value of L / D without changing the design of the entire casing, and to achieve both reduction in the amount of evaporated fuel emitted to the atmosphere and improvement in production efficiency. An evaporative fuel processing apparatus is to be provided.

  As means for solving the above-mentioned problems, the invention according to claim 1 is provided with a charge port connected to the fuel tank and a purge port connected to the intake portion of the engine on one end side of the casing. At the same time, an evaporative fuel processing apparatus is provided on the other end side of the casing, which is provided with an atmospheric port that conducts to the atmosphere, and the casing is filled with an adsorbent.

  In addition, the inner part of the casing on the other end side where the atmospheric port is provided has a cross section that is separate from the casing and smaller than the cross sectional area of the part, and gas can flow at both ends. This portion is made into a double wall structure by loading a cylindrical adsorbent cartridge formed on the outer surface of the casing, and the outer portion of the adsorbent cartridge has an outer portion at the end located on the charge port and purge port side. In addition to forming a flange having the same shape as the inner surface of the casing, a cylindrical portion is formed at the end located on the atmosphere port side, and a cylindrical wall is provided in a stepped portion in the portion of the casing where the atmosphere port is disposed. The flange portion is inscribed in the inner peripheral surface of the casing, and the cylindrical portion is fitted to the cylindrical wall of the casing, so that the gap between the casing and the adsorbent cartridge is obtained. Adsorbent was isolated form the unfilled space that does not flowing gas if there are no be filled.

  According to the second aspect of the present invention, the interior of the casing is formed so as to be separated from the first filling chamber and the second filling chamber, and the ends of the first filling chamber and the second filling chamber are communicated with each other. A character-shaped passage is formed, and a charge port connected to the fuel tank and a purge port connected to the intake portion of the engine are provided on the other end side of the first filling chamber, and the second filling is performed. On the other end side of the chamber, an evaporative fuel processing apparatus is provided, which is provided with an atmospheric port that conducts to the atmosphere, and the first and second filling chambers are filled with an adsorbent.

  Then, in the inner part of the other end side where the atmospheric port is provided in the second filling chamber, it is separate from the casing forming the second filling chamber and from the cross-sectional area of the part of the second filling chamber. A cylindrical adsorbent cartridge having a small cross section and formed so as to allow gas to flow at both ends is used to make the portion a double wall structure. A flange having an outer shape that is substantially the same shape as the inner surface shape of the portion of the second filling chamber is formed at the end located at one end of the filling chamber, and a cylindrical portion at the end located at the other end of the second filling chamber While forming a cylindrical wall in a stepped manner at the other end side where the atmospheric port is arranged in the second filling chamber, and inscribed the flange portion on the inner peripheral surface of the second filling chamber, The second filling chamber is formed by fitting the tubular portion to the cylindrical wall of the second filling chamber. Between the formation to which the casing with the adsorbent cartridge was isolated form the unfilled space adsorbent neither flowing gas if there are no be filled.

  The invention described in claim 3 clarifies that the adsorbent cartridge in the invention described in claim 1 or 2 is filled with granular activated carbon in advance.

  In these inventions, the ratio L / D between the length L of the adsorbent layer and the effective cross-sectional diameter D is guaranteed at least by the L / D of the adsorbent filling portion of the adsorbent cartridge. Since the adsorbent filling portion of the cartridge has a smaller cross-sectional area than the other adsorbent filling portions in the casing and the D value of the L / D is small, the L / D value is easily set large. Can do. Therefore, the L / D value of the entire apparatus can be easily changed with respect to those not loaded with an adsorbent cartridge by loading an adsorbent cartridge having a different L / D value without changing the casing design. it can.

  In particular, since the adsorbent cartridge is loaded in the casing so that the flange contacts the inner wall of the casing, a space defined by the flange of the adsorbent cartridge is formed in the casing. Therefore, the assembly of the apparatus can be easily advanced by filling the space thus formed with the adsorbent. Further, the flange of the adsorbent cartridge can regulate backlash in the casing and also functions as a guide when the cartridge is inserted into the casing. Furthermore, since the contact area with respect to the inner wall of a casing is small, the sliding resistance at the time of an assembly | attachment can be made small.

  Further, since the cylindrical portion of the adsorbent cartridge is attached to the cylindrical wall on the casing side, the air introduced from the atmospheric port and the evaporated fuel in the casing do not pass through the outer peripheral side of the adsorbent cartridge, and the inside of the adsorbent cartridge Will pass. As a result, the intended function of the adsorbent cartridge can be reliably exhibited.

  As described above, according to the present invention, the casing is loaded with the adsorbent cartridge having a smaller cross-sectional area of the adsorbent filling portion than the inner cross section of the other adsorbent filling portion in the passage. The L / D value of the entire apparatus can be easily changed by exchanging the adsorbent cartridge without changing the whole. Therefore, it is possible to achieve both reduction in the amount of evaporated fuel emitted into the atmosphere and improvement in production efficiency.

  Next, embodiments of the present invention will be described with reference to the drawings.

  First, the first embodiment shown in FIGS. 1 to 3 will be described. In FIG. 1, 20 is a casing of the evaporative fuel processing apparatus formed of a resin material. A charge port 21 connected to the fuel tank and a purge port 22 connected to the intake portion of the engine are provided on one end side of the casing 20, and an air port 23 communicating with the atmosphere is provided on the other end side of the casing 20. Each is provided. Further, the inside of the casing 20 is divided into a first filling chamber 24 that communicates with the charge port 21 and the purge port 22 and a second filling chamber 25 that communicates with the atmospheric port 23. , 22, 23 are connected to each other through the connection path 26. Therefore, a substantially U-shaped passage is formed in the casing 20 by the first filling chamber 24, the connection path 26, and the second filling chamber 25. The second filling chamber 25 is formed in a smaller cross section than the first filling chamber 24, and has a cross-sectional area of approximately one half of the cross-sectional area of the first filling chamber 24.

  Filters 27a and 27b are disposed at positions facing the charge port 21 and the purge port 22 of the first filling chamber 24, respectively, and are supported by the porous plate 28 at the end of the first filling chamber 24 on the connection path 26 side. A filter 29 is arranged. The perforated plate 28 is slidably fitted to the inner wall of the first filling chamber 24 and is urged by the spring 30 toward the ports 21 and 22. And between the filters 27a and 27b and the filter 29, the activated carbon 31 which is an adsorbent is filled. This activated carbon filling portion is hereinafter referred to as “first activated carbon layer 31A”.

  On the other hand, the end of the second filling chamber 25 on the atmosphere port 23 side, that is, the other end side of the casing 20 is loaded with an adsorbent cartridge 32 to be described later, and the end of the second filling chamber 25 on the connection path 26 side. Similar to the first filling chamber 24, a filter 34 supported by the perforated plate 33 is disposed in the part. The perforated plate 33 forms an end wall together with the filter 34, is slidably fitted to the inner wall of the second filling chamber 25, and is urged toward the port 23 by a spring 35. The adsorbent cartridge 32 and the filter 34 are filled with activated carbon, and the adsorbent cartridge 32 is similarly filled with activated carbon 31. Hereinafter, the activated carbon filling portion between the adsorbent cartridge 32 and the filter 34 is referred to as “second activated carbon layer 31B”, and the activated carbon filling portion in the cartridge 32 is referred to as “third activated carbon layer 31C”.

  Here, the first activated carbon layer 31A and the second activated carbon layer 31B are movable because the end walls (the porous plates 28 and 33 and the filters 29 and 34) are urged by the springs 30 and 35. The amount of filled activated carbon can be arbitrarily adjusted according to the specifications. On the other hand, the activated carbon filling amount of the cartridge 32 is fixed.

  Incidentally, in this example, the adsorbed layers 31A, 31B, 31C are filled with granular activated carbon 31 such as crushed charcoal and formed charcoal. A large heat storage material such as aluminum or ceramic may be mixed and filled at random, or may be alternately arranged in layers and filled. Alternatively, the adsorbent and the heat storage material may be preliminarily solidified together with a binder to form particles, and the mixture may be filled as adsorbing layers 31A, 31B, and 31C. When the heat storage material is filled together with the adsorbent in this way, the adsorption performance can be improved by absorbing the heat of the adsorbent with the heat storage material when the fuel vapor is adsorbed, and stored with the heat storage material when the evaporated fuel is desorbed. The temperature decrease of the adsorbent can be suppressed by the generated heat, thereby increasing the amount of evaporated fuel desorbed from the adsorbent. In the following description of the other embodiments, repeated description is omitted, but the adsorbent filling portion (adsorption layer) is filled with the heat storage material in the above-described form, or the heat storage material mixture is granular. It is the same that may be filled.

  2 and 3 show details of the adsorbent cartridge 32. FIG. This adsorbent cartridge 32 has a cross-sectional area in a direction perpendicular to the gas flow in the second filling chamber 25, that is, a cross-sectional area of the portion of the casing 20 into which the adsorbent cartridge 32 is inserted (the portion concerned). The cartridge main body 36 is formed in a cylindrical shape with a small cross section and filled with activated carbon 31 inside, and the end of the cartridge main body 36 on the port 23 side is substantially perpendicular to the insertion direction (axial direction) of the cartridge 32. A first flange 37 that extends outward, a second flange 38 that similarly extends at the opposite end of the main body 36, and an end surface of the cartridge main body 36 on the port 23 side along the axial direction. And a cylindrical portion 39 extended. As shown in FIG. 2, a cylindrical wall 40 is formed in the air port 23 forming portion of the casing 20 so as to be stepped with respect to the inner wall of the second filling chamber 25. The first flange 37 of the adsorbent cartridge 32 is brought into contact with the step portion, and the cylindrical portion 39 of the cartridge 32 is inserted inside the cylindrical wall 40. A U-shaped packing 41 is attached to the outer peripheral surface of the tubular portion 39 as a sealing member, and the space between the tubular portion 39 and the tubular wall 40 is sealed by the packing 41. Even if the outer diameter of the cylindrical portion 39 and the inner diameter of the cylindrical wall 40 are made substantially equal without providing the packing 41, there is no practical problem.

  The cartridge main body 36 is provided with filters 42a and 42b at both ends thereof, and the activated carbon 31 is filled between the filters 42a and 42b. The filters 42a and 42b are made of flexible urethane, non-woven fabric or the like, and can allow the volume change of the third activated carbon layer 31C due to heat or the like. Further, the first flange 37 and the second flange 38 are formed so that their outer peripheral edge portions are along the inner surface shape of the second filling chamber 25, and are slidably fitted to the inner surface of the second filling chamber 25. It has come to be.

  Further, a filter 43 made of nonwoven fabric is welded and fixed to the side surface of the second flange 38 on the second activated carbon layer 31B side. The filter 43 is for holding and holding the activated carbon 31 of the second activated carbon layer 31 </ b> B, and is formed to be slightly larger than the outer peripheral edge of the second flange 38. Therefore, when the cartridge 32 is loaded into the second filling chamber 25 and the second flange 38 is fitted into the second filling chamber 25, the outer peripheral edge of the filter 43 is slightly compressed, and the passage Adhering to the inner wall, the outflow of the activated carbon 31 from the gap between the second flange 38 and the second filling chamber 25 can be reliably prevented. 2, 44 is a support pin that projects from the second flange 38 to position and support the filter 43, and 45 is provided in the opening on the port 23 side of the cartridge body 36 to support the filter 42a. It is a rib to do.

  Here, in the third activated carbon layer 31C in the adsorbent cartridge 32, the ratio L / D between the length L and the effective sectional diameter D is set to 1.5. As a result of various tests and researches, it has been found that this L / D is a value of 1.0 or more from the viewpoint of preventing the evaporated fuel from being released into the atmosphere. In this embodiment, the L / D is 1 with a margin. .5. Since the L / D value of the entire apparatus can be calculated as the sum of the L / D values of the first to third activated carbon layers 31A to 31C, the volume of the first and second activated carbon layers 31A and 31B is changed. However, the L / D value of the entire apparatus is always guaranteed to be the L / D value of the adsorbent cartridge 32, that is, 1.5 or more.

  The capacity of the third activated carbon layer 31C is set to approximately 3% of the total activated carbon layer volume. This volume ratio is desirably 10% or less even when the volumes of the first and second activated carbon layers 31A and 31B are changed.

  As described above, the cylindrical adsorbent cartridge 32 provided with the first and second flanges 37 and 38 in a part of the casing 20, more specifically, in the portion near the atmospheric port 23 in the second filling chamber 25. By being loaded, the portion has a substantially double-wall structure, and the casing 20 and the adsorbent cartridge 32 are not filled with activated carbon as an adsorbent as will be described later. In addition to the atmosphere, a non-filling space R in which no gas during charging or purging flows is formed.

  Since the evaporative fuel processing apparatus has the above-described configuration, evaporative fuel generated from the fuel tank when the vehicle is stopped is introduced into the casing 20 through the charge port 21 and is adsorbed by the activated carbon 31. Evaporated fuel is mainly composed of a mixture of hydrocarbon compound (hereinafter referred to as “HC”) gas and air, HC is adsorbed by activated carbon 31, and air passes through activated carbon layers 31 </ b> A to 31 </ b> C and atmospheric port 23. Released into the atmosphere.

  When the engine is in operation, the air passes through the air port 23, the activated carbon layers 31C, 31B, 31A, and the purge port 22 in order and is sucked into the engine. At that time, the HC adsorbed on the activated carbon 31 is purged by the passing air. The desorption of HC from the activated carbon 31 moves from the third activated carbon layer 31C side to the first activated carbon layer 31A side, and the desorbed HC passes through the purge port 22 and is introduced into the intake portion of the engine. Used for combustion. The adsorption capacity of the activated carbon 31 is regenerated by such a purge.

  Here, in the activated carbon layers 31A to 31C, a slight amount of HC that cannot be desorbed by such a purge remains, and the HC becomes a gas and diffuses into the activated carbon layers 31A to 31C. The fuel processing apparatus sets the L / D of the third activated carbon layer 31C in the adsorbent cartridge 32 to 1.5 so that the L / D of the entire apparatus is further increased. , And thereby the atmospheric emissions can be kept extremely low.

  In the case of this apparatus, since the capacity of the activated carbon layer 31C in the cartridge 32 is very small, approximately 3% of the total activated carbon capacity, the amount of outside air introduced through this layer 31C when the engine is operated and this layer 31C. The capacity ratio, that is, the purge bed volume is increased. For this reason, when the engine is in operation, the third activated carbon layer 31C can be sufficiently purged to reliably desorb the adsorbed fuel from the activated carbon layer 31C. Therefore, when evaporated fuel is introduced from the fuel tank, the HC gas that has passed through the second activated carbon layer 31B can be reliably adsorbed by the third activated carbon layer 31C.

  By the way, in the method of assembling the fuel vapor processing apparatus, the adsorbent cartridge 32 is manufactured in advance, and this is loaded into the second filling chamber 25 of the casing 20, and the filters 27 a and 27 b are further loaded into the first filling chamber 24. Then, the remaining parts of the first filling chamber 24 and the second filling chamber 25 are filled with activated carbon 31. Next, the filters 29 and 34, the perforated plates 28 and 33, and the springs 30 and 35 are disposed in the casing 20, respectively, and finally, a cover 20c is attached to the main body of the casing 20 and its outer peripheral edge is welded. Complete the assembly of the device.

  As described above, the evaporative fuel processing apparatus has been able to suppress the atmospheric emission of the fuel component (HC) almost completely by increasing the L / D of the entire apparatus. It is only necessary to load the adsorbent cartridge 32 into the casing 20 having the same shape as the existing one. That is, since the activated carbon filling portion (cartridge main body portion 36) of the adsorbent cartridge 32 is formed in a smaller cross section than the inner cross section of the second filling chamber 25, the L / D of the cartridge 32 itself should be easily set large. In addition, the L / D value of the entire apparatus can be ensured to be equal to or higher than the L / D of the cartridge 32 by loading the cartridge 32. Of course, it is also possible to produce the apparatus loaded with the cartridge 32 and the apparatus not loaded (equipment with different L / D) on the same line or by switching.

  And by appropriately manufacturing the adsorbent cartridge with different activated carbon layer length L and effective cross-sectional area D, it matches the engine displacement, fuel tank size, etc. It is possible to easily provide an evaporative fuel processing apparatus.

  In particular, in the case of this embodiment, the adsorbent cartridge 32 has a first flange 37 and a second flange 38 extending on both front and rear sides of the main body 36, and the side surface of the second flange 38 on the second activated carbon layer 31B side. Since the filter 43 forming the holding wall of the activated carbon 31 is welded to the second filling chamber 25, the activated carbon 31 for the second activated carbon layer 31 </ b> B is directly put into the second filling chamber 25 as long as the cartridge 32 is loaded in the second filling chamber 25. Can be filled. Therefore, the assembly efficiency of the evaporative fuel processing device can be increased.

  Further, in the case of this cartridge 32, since the first flange 37 and the second flange 38 are fitted in the second filling chamber 25, it is possible to suppress the play of the cartridge 32 after assembly, and the cartridge 32. At the time of loading, the inner surface of the second filling chamber 25 is brought into contact with only the narrow flanges 37 and 38, so that there is an advantage that the slidability of the cartridge 32 can be improved and the assembling workability can be improved.

  Further, the adsorbent cartridge 32 causes the first flange 37 to abut on the stepped portion of the cylindrical wall 40 of the casing 20, and the cylindrical portion 39 is inserted into the cylindrical wall 40 of the casing 20. Since the wall 40 is sealed with a U-shaped packing 41 and assembled in the second filling chamber 25, the fuel component that has passed through the second activated carbon layer 31B does not pass through the third activated carbon layer 31C, but the outer periphery of the cartridge 32. The problem is that the air that has traveled around the side (non-filling space R) and diffused into the atmospheric port 23 or that the air introduced from the atmospheric port 23 flows into the second activated carbon layer 31B without passing through the third activated carbon layer 31C. Does not occur. Therefore, the fuel vapor and the atmosphere can be reliably guided to the third activated carbon layer 31C.

  In addition, since the amount of fuel evaporation varies depending on the size and shape of the fuel tank, the amount of activated carbon varies depending on the specifications of the fuel tank when the evaporated fuel processing device is applied to such a vehicle having different fuel tank specifications. It is necessary to use something. In the case of the fuel vapor processing apparatus of this embodiment, the end walls (the porous plates 28 and 33 and the filters 29 and 34) of the first filling chamber 24 and the second filling chamber 25 are biased by the springs 30 and 35. Therefore, the amount of the activated carbon 31 filled in both the filling chambers 24 and 25 at the time of assembly can be arbitrarily changed according to the specifications of the fuel tank. Also in this case, the necessary L / D of the entire apparatus can be reliably guaranteed by the adsorbent cartridge 32. Therefore, this evaporative fuel processing device can easily make devices of various specifications without causing atmospheric emission exceeding the prescribed value of evaporative fuel.

  Next, a second embodiment shown in FIGS. 4 and 5 will be described.

  FIG. 4 is a partial cross-sectional view of the evaporative fuel processing apparatus. In the apparatus of this embodiment, as shown in the figure, an atmospheric port 53 communicating with the atmosphere is disposed at a 90 ° direction in the other end of the casing 20a. The cartridge 52 is bent in a substantially L shape so as to change, and the shape of the cartridge 52 is different from that of the above embodiment.

  The cartridge 52 includes a first flange 57 extending inwardly at a port 53 side end portion of the cartridge main body portion 56 in a direction substantially perpendicular to the cartridge insertion direction (axial direction) and an end on the opposite side of the main body portion 56. A second flange 58 extending outward in a direction substantially perpendicular to the cartridge insertion direction (axial direction), and a cylindrical portion 59 extending so as to protrude in the axial direction from the inner edge of the first flange 57. It has.

  As shown in FIG. 4, a cylindrical wall 50 constricted in a step shape with respect to the inner wall of the second filling chamber 25 is formed in the atmospheric port forming portion of the casing 20 a. The first flange 57 of the adsorbent cartridge 52 is brought into contact with the portion, and the cylindrical portion 59 of the cartridge 52 is inserted inside the cylindrical wall 50. An O-ring 51 as a seal member is attached to the outer peripheral surface of the cylindrical portion 59, and the space between the cylindrical portion 59 and the cylindrical wall 50 is sealed by the O-ring 51. A plurality of ribs 60 are formed integrally with the second flange 58 around the cartridge main body 56, and the outer peripheral edges of the second flange 58 and the rib 60 are in the second filling chamber 25. It is formed so as to conform to the inner surface shape of the portion, and is slidably fitted into the filling chamber 25.

  In the above description of the embodiment, a U-shaped packing or an O-ring is used as a seal member interposed between the cylindrical portion of the adsorbent cartridge and the cylindrical wall of the casing. It is also possible to use a D-shaped sealing member.

  In the above, the embodiment in which the passage in the casing is formed in a substantially U-shape has been described. However, as in the third embodiment shown in FIG. 6, the charge port 21 and the purge are arranged on one end side in the axial direction of the casing 20 b. A straight passage shape in which an air port 23 is provided on the other end side of the port 22 may be used. In this embodiment, there are two activated carbon layers, and the first activated carbon layer 31A (or the second activated carbon layer 31B) is eliminated from the first embodiment. In addition, about this embodiment, the same code | symbol shall be attached | subjected to the same part as 1st Embodiment, and the overlapping description shall be abbreviate | omitted.

  Further, in the embodiment described above, the adsorbent cartridge is manufactured in advance and the cartridge is assembled in the casing. However, without preparing the adsorbent cartridge assembled in advance, packing or O The cartridge body with the ring assembled may be attached to the cylindrical wall in the casing, and in that state, the filter, activated carbon, and filter may be sequentially assembled to the cartridge body.

Sectional drawing which shows 1st Embodiment of invention of this application. The partial expanded sectional view of FIG. 1 which shows the same embodiment. The perspective view of the adsorption material filling cartridge which shows the same embodiment. The partial expanded sectional view which shows 2nd Embodiment of invention of this application. The perspective view of the adsorption material filling cartridge which shows the same embodiment. Sectional drawing which shows 3rd Embodiment of invention of this application. The perspective view which shows the prior art.

Explanation of symbols

20, 20a, 20b ... casing 21 ... charge port 22 ... purge port 23, 53 ... atmospheric port 24 ... first filling chamber 25 ... second filling chamber 31 ... activated carbon (adsorbent)
31A ... 1st activated carbon layer (adsorbent filling part)
31B ... 2nd activated carbon layer (adsorbent filling part)
31C ... 3rd activated carbon layer (adsorbent filling part)
32, 52 ... Adsorbent cartridge 37, 57 ... First flange (flange)
38, 58 ... 2nd flange (flange)
39, 59 ... cylindrical portion 40, 50 ... cylindrical wall R ... non-filling space

Claims (3)

A charge port connected to the fuel tank and a purge port connected to the intake portion of the engine are provided on one end side of the casing, and an air port conducting to the atmosphere is provided on the other end side of the casing. In the evaporative fuel processing apparatus in which the adsorbent is filled in the casing,
The inner part of the casing on the other end side where the atmospheric port is provided is formed separately from the casing so as to have a cross section smaller than the cross sectional area of the part and to allow gas to flow at both ends. By loading a cylindrical adsorbent cartridge, this part has a double wall structure,
The adsorbent cartridge has a flange whose outer shape is substantially the same as the inner surface shape of the portion of the casing at the end located on the charge port and purge port side, and at the end located on the atmosphere port side. While forming the tube part,
A cylindrical wall is provided in a stepped shape in the portion of the casing where the atmospheric port is disposed,
The flange portion is inscribed in the inner peripheral surface of the casing, and the cylindrical portion is fitted to the cylindrical wall of the casing, so that a gas is used unless an adsorbent is filled between the casing and the adsorbent cartridge. An evaporative fuel processing apparatus characterized in that a non-filling space that does not circulate is isolated and formed. The inside of the casing is formed separately from the first filling chamber and the second filling chamber, and a substantially U-shaped passage is formed by communicating one end portions of the first filling chamber and the second filling chamber. With
A charge port connected to the fuel tank and a purge port connected to the intake portion of the engine are provided on the other end side of the first filling chamber, and are connected to the atmosphere on the other end side of the second filling chamber. An atmospheric port is provided,
In the evaporative fuel processing apparatus in which the adsorbent is filled in the first filling chamber and the second filling chamber,
A cross section smaller than the cross-sectional area of the part of the second filling chamber is separate from the casing forming the second filling chamber in the inner part on the other end side where the atmospheric port is provided in the second filling chamber. It has a double wall structure by loading a cylindrical adsorbent cartridge formed so as to allow gas flow at both ends.
In the adsorbent cartridge, a flange having an outer shape that is substantially the same as the inner surface shape of the portion of the second filling chamber is formed at the end located on one end side of the second filling chamber, and the other end of the second filling chamber. While forming the cylindrical part at the end located on the side,
In the second filling chamber, a cylindrical wall is provided in a step shape on the other end side where the atmospheric port is disposed,
A casing and an adsorbent cartridge forming the second filling chamber by causing the flange portion to contact the inner peripheral surface of the second filling chamber and fitting the cylindrical portion to the cylindrical wall of the second filling chamber An evaporative fuel processing apparatus characterized in that a non-filling space in which no gas flows if it is not filled with an adsorbent is isolated between the two.   The evaporative fuel processing apparatus according to claim 1 or 2, wherein the adsorbent cartridge is preliminarily filled with granular activated carbon.

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