United States Patent (19)
`Yamazaki et al.
`
`54 EVAPORATIVE FUEL PROCESSING DEVICE
`75 Inventors: Kazumi Yamazaki; Koichi Hidano;
`Teruo Wakashiro; Takeshi Hara, all
`of Wako; Tomoyuki Kawakami, Haga,
`all of Japan
`73) Assignee: Honda Giken Kogyo Kabushiki
`Kaisha, Tokyo, Japan
`
`(21) Appl. No.: 317,804
`22 Filed:
`Oct. 4, 1994
`30
`Foreign Application Priority Data
`Oct. 4, 1993
`JP
`Japan .................................... 5-248245
`(51) Int. Cl. ................................. F02M 33/02
`52 U.S. Cl. .........
`... 123/520; 123/519
`58 Field of Search ..................................... 123/520,521,
`123/518, 519, 516, 198 D; 55/387
`References Cited
`U.S. PATENT DOCUMENTS
`4,790,283 12/1988 Uranishi .................................. 123/520
`4,815,436 3/1989 Sasaki .......
`123/520
`4,887,578 12/1989 Woodcock
`123/519
`4,951,643 8/1990 Sato ..........
`123/520
`5,056,494 10/1991 Kayanuma .............................. 123/516
`5,337,721
`8/1994 Kasuya .................................... 123/519
`
`56)
`
`
`
`III IIII
`US005456237A
`11
`Patent Number:
`5,456,237
`(45) Date of Patent:
`Oct. 10, 1995
`
`5,393,329 2/1995 Inagaki ou e o so as a w w
`
`a
`
`so a a as a ww. 1231519 R
`
`FOREIGN PATENT DOCUMENTS
`... 123/519
`4121451 4/1992 Japan ......
`123/519
`4153556 5/1992 Japan ......
`... 123/519
`5195884 8/1993 Japan ......
`5280435 10/1993 Japan ..................................... 123/519
`Primary Examiner-Carl S. Miller
`Attorney, Agent, or Firm-Nikaido, Marmelstein, Murray &
`Oram
`ABSTRACT
`57)
`In an evaporative fuel processing device, a canister is
`divided into first, second, third and fourth chambers by
`partition walls. A control valve is provided in a communi
`cation passage which connects the second and third cham
`bers to each other. A first charge passage is connected to an
`upper space in a fuel tank and to a port in the third chamber,
`and a second charge passage is connected to a fuel supply
`valve for the fuel tank and to a port in the first chamber.
`Further, a purge passage is connected to an intake passage of
`an internal combustion engine and to a port in the first
`chamber. The control valve is connected to an electronic
`control unit, and opened during refueling and during trav
`eling of a vehicle and closed during parking of the vehicle.
`Thus, it is possible to reliably prevent an evaporative fuel
`from being released to the atmosphere, while the capacity of
`the canister to a minimum.
`
`5 Claims, 7 Drawing Sheets
`
` MAHLE-1021
`U.S. Patent No. RE38,844
`
`

`

`US. Patent
`U.S. Patent
`
`Oct. 10, 1995
`Oct. 10, 1995
`
`Sheet 1 of 7
`Sheet 1 of 7
`
`5,456,237
`5,456,237
`
`
`
`
`
`

`

`U.S. Patent
`US. Patent
`
`Oct. 10, 1995
`Oct. 10, 1995
`
`Sheet 2 of 7
`Sheet 2 of 7
`
`5,456,237
`5,456,237
`
`FIG.2A
`FIG.2A
`
`Swami/”MC
`Jr/Az/I/c
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`

`

`U.S. Patent
`US. Patent
`
`
`
`Oct. 10, 1995
`Oct. 10, 1995
`
`Sheet 3 of 7
`Sheet 3 of 7
`
`5,456,237
`5,456,237
`
`
`
`

`

`US. Patent
`U.S. Patent
`
`Oct. 10, 1995
`Oct. 10, 1995
`
`Sheet 4 of 7
`Sheet 4 of 7
`
`5,456,237
`5,456,237
`
`
`
`FIG.4C
`
`FG4B
`FIG.4B
`
`
`
`
`
`FIG.4D
`
`FIG.4D
`
`
`
`
`

`

`US. Patent
`U.S. Patent
`
`Oct. 10, 1995
`Oct. 10, 1995
`
`Sheet 5 of 7
`Sheet S of 7
`
`5,456,237
`5,456,237
`
`
`
`t
`
`FIG.5
`
`

`

`US. Patent
`U.S. Patent
`
`Oct. 10, 1995
`Oct. 10, 1995
`
`Sheet 6 of 7
`Sheet 6 of 7
`
`5,456,237
`5,456,237
`
`
`
` :JI
`
`V'-
`wer
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`

`

`1.
`1
`EVAPORATIVE FUEL PROCESSING DEVICE
`EVAPORATIVE FUEL PROCESSING DEVICE
`
`5,456,237
`5,456,237
`
`5
`5
`
`10
`10
`
`15
`15
`
`20
`20
`
`25
`25
`
`30
`30
`
`35
`35
`
`40
`40
`
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`1. Field of the Invention
`The present invention relates to an evaporative fuel pro
`The present invention relates to an evaporative fuel pro-
`cessing device including a canister for adsorbing an evapo
`cessing device including a canister for adsorbing an evapo-
`rative fuel generated in a fuel tank of a vehicle.
`rative fuel generated in a fuel tank of a vehicle.
`2. Description of the Prior Art
`2. Description of the Prior Art
`FIG. 5 illustrates a prior art evaporative fuel processing
`FIG. 5 illustrates a prior art evaporative fuel processing
`device, in which a first charge passage 01, a second charge
`device, in which a first charge passage 01, a second charge
`passage 02 and a purge passage 03 are connected to one of
`passage 02 and a purge passage 03 are connected to one of
`end faces of a canister in which an adsorbent is accommo-
`end faces of a canister in which an adsorbent is accommo
`dated. An atmosphere-opened passage 04 is defined in the
`dated. An atmosphere-opened passage 04 is defined in the
`other end face. The first charge passage 01 is connected to
`other end face. The first charge passage 01 is connected to
`an upper space in a fuel tank Tthrough a two-way valve 05,
`an upper space in a fuel tank T through a two-way valve 05,
`and the second charge passage 02 is connected to a breather
`and the second charge passage 02 is connected to a breather
`tube of the fuel tank T through a fuel supply valve 06.
`tube of the fuel tank T through a fuel supply valve 06.
`Further, the purge passage 03 is connected to an intake
`Further, the purge passage 03 is connected to an intake
`passage of an internal combustion engine through a purge
`passage of an internal combustion engine through a purge
`valve 07 which is controlled for opening and closing by an
`valve 07 which is controlled for opening and closing by an
`electronic control unit U.
`electronic control unit U.
`With such a prior art evaporative fuel processing device,
`With such a prior art evaporative fuel processing device,
`an evaporative fuel generated during parking or traveling of
`an evaporative fuel generated during parking or traveling of
`a vehicle is charged to the canister C through the first charge
`a vehicle is charged to the canister C through the first charge
`passage 01, and an evaporative fuel generated during refu
`passage 01, and an evaporative fuel generated during refu—
`eling into the vehicle is charged to the canister C through the
`eling into the vehicle is charged to the canister C through the
`second charge passage 02. The evaporative fuel charged to
`second charge passage 02. The evaporative fiiel charged to
`the canister C is purged into the intake passage 08 through
`the canister C is purged into the intake passage 08 through
`the purge passage 03.
`the purge passage 03.
`FIG. 6 illustrates another prior art evaporative fuel pro
`FIG. 6 illustrates another prior art evaporative fuel pro-
`cessing device, in which a first canister Ca is interposed
`cessing device, in which a first canister Ca is interposed
`between a first charge passage 01 and a first purge passage
`between a first charge passage 01 and a first purge passage
`03a, and a second canister Cb is interposed between a
`03a, and a second canister Cb is interposed between a
`second charge passage 02 and a second purge passage 03b.
`second charge passage 02 and a second purge passage 03b.
`Purge valves 07a and 07b are provided in the first and
`Purge valves 07a and 07b are provided in the first and
`second purge passage 03a and 03b, respectively and are
`second purge passage 03a and 03]), respectively and are
`controlled for opening and closing by an electronic control
`controlled for opening and closing by an electronic control
`unit U.
`unit U.
`With this evaporative fuel processing device, an evapo
`With this evaporative fuel processing device, an evapo-
`rative fuel generated during parking and traveling of a
`rative fuel generated during parking and traveling of a
`45
`vehicle is charged to the first canister Ca through the first
`vehicle is charged to the first canister Ca through the first
`45
`charge passage 01, and an evaporative fuel generated during
`charge passage 01, and an evaporative fuel generated during
`refueling into a vehicle is charged to the second canister Cb
`refueling into a vehicle is charged to the second canister Cb
`through the second charge passage 02. The evaporative fuels
`through the second charge passage 02. The evaporative fuels
`charged to the first and second canisters Ca and Cb are
`charged to the first and second canisters Ca and Cb are
`purged into the intake passage 08 through the first and
`purged into the intake passage 08 through the first and
`second purge passages 03a and 03b.
`second purge passages 03a and 0312.
`In the evaporative fuel processing device shown in FIG.
`In the evaporative fuel processing device shown in FIG.
`5, the evaporative fuel generated in the fuel tank T during
`5, the evaporative fuel generated in the fuel tank T during
`refueling is supplied to the canister C through the second
`refueling is supplied to the canister C through the second
`charge passage 02 to charge the canister C at a high
`charge passage 02 to charge the canister C at a high
`concentration (see FIG. 7A). Thereafter, when the vehicle
`concentration (see FIG. 7A). Thereafter, when the vehicle
`travels, the purge passage 03 is evacuated into a negative
`travels, the purge passage 03 is evacuated into a negative
`pressure, causing air to be introduced through the atmo
`pressure, causing air to be introduced through the atmo-
`sphere-opened passage 04 into the canister C, thereby purg
`sphere‘opened passage 04 into the canister C, thereby purg—
`ing the canister C. In this case, when the time of traveling of
`ing the canister C. In this case, when the time of traveling of
`the vehicle is long, the purging of the canister is completely
`the vehicle is long, the purging of the canister is completely
`performed, but when the time of traveling of the vehicle is
`performed, but when the time of traveling of the vehicle is
`short, only a left half of the canister C near the atmosphere
`short, only a left half of the canister C near the atmosphere-
`opened passage 04 is purged and hence, the concentration of
`opened passage 04 is purged and hence, the concentration of
`fuel adsorbed in the left half is reduced into a lower level,
`fuel adsorbed in the left half is reduced into a lower level,
`but the concentration of fuel adsorbed in the right half is
`but the concentration of fuel adsorbed in the right half is
`maintained at a higher level (see FIG. 7B).
`maintained at a higher level (see FIG. 7B).
`
`60
`60
`
`50
`50
`
`55
`55
`
`65
`65
`
`2
`2
`When the vehicle is parked to discontinue the purging, the
`When the vehicle is parked to discontinue the purging, the
`adsorbed fuel of the higher concentration in the right half of
`adsorbed fuel of the higher concentration in the right half of
`the canister C is diifused into the left half, so that the
`the canister C is diffused into the left half, so that the
`concentration of the adsorbed fuel in the entire canister C is
`concentration of the adsorbed fuel in the entire canister C is
`brought into a medium level (see FIG.7C). Thereafter, when
`brought into a medium level (see FIG. 7C). Thereafter, when
`the evaporative fuel is supplied through the first charge
`the evaporative fuel is supplied through the first charge
`passage 01 to the canister C due to an increase in tempera
`passage 01 to the canister C due to an increase in tempera—
`ture in the fuel tank T, there is caused a problem that the
`ture in the fuel tank T, there is caused a problem that the
`evaporative fuel supplied cannot completely be adsorbed to
`evaporative fuel supplied cannot completely be adsorbed to
`the canister C which has already been charged at the medium
`the canister C which has already been charged at the medium
`concentration, and such evaporative fuel may be released
`concentration, and such evaporative fuel may be released
`through the atmosphere-opened passage 04 to the atmo
`through the atmosphere-opened passage 04 to the atmo—
`sphere. (see FIG. 7D).
`sphere. (see FIG. 7D).
`In the evaporative fuel processing device shown in FIG.
`In the evaporative fuel processing device shown in FIG.
`6, the two first and second canisters Ca and Cb are required,
`6, the two first and second canisters Ca and Cb are required,
`resulting not only in a complicated structure, but also in a
`resulting not only in a complicated structure, but also in a
`problem that the first canister Ca does not at all contribute
`problem that the first canister Ca does not at all contribute
`to the adsorption of the evaporative fuel generated in a large
`to the adsorption of the evaporative fuel generated in a large
`amount during refueling. Therefore, it is necessary to insure
`amount during refueling. Therefore, it is necessary to insure
`a large capacity for the second canister Cb and thus, the
`a large capacity for the second canister Cb and thus, the
`entire canister must be enlarged.
`entire canister must be enlarged.
`
`SUMMARY OF THE INVENTION
`SUMMARY OF THE INVENTION
`Accordingly, it is an object of the present invention to
`Accordingly, it is an object of the present invention to
`reliably prevent the evaporative fuel from being released to
`reliably prevent the evaporative fuel from being released to
`the atmosphere, without an unneeded increase in capacity of
`the atmosphere, without an unneeded increase in capacity of
`the canister.
`the canister.
`To achieve the above object, according to a first aspect
`To achieve the above object, according to a first aspect
`and feature of the present invention, there is provided an
`and feature of the present invention, there is provided an
`evaporative fuel processing device comprising a canister, a
`evaporative fuel processing device comprising a canister, a
`charge passage connected to a fuel tank and to the canister,
`charge passage connected to a fuel tank and to the canister,
`and a purge passage connected to an intake passage of an
`and a purge passage connected to an intake passage of an
`internal combustion engine and to the canister, in which an
`internal combustion engine and to the canister, in which an
`evaporative fuel generated in the fuel tank is supplied to the
`evaporative fuel generated in the fuel tank is supplied to the
`canister through the charge passage and adsorbed to an
`canister through the charge passage and adsorbed to an
`adsorbent accommodated in the canister, and an evaporative
`adsorbent accommodated in the canister, and an evaporative
`fuel released from the adsorbent is supplied into the intake
`fuel released from the adsorbent is supplied into the intake
`passage of the internal combustion engine through the purge
`passage of the internal combustion engine through the purge
`passage, wherein the device further comprises a first and a
`passage, wherein the device further comprises a first and a
`second adsorbent accommodating space defined in the can
`second adsorbent accommodating space defined in the can-
`ister, a communication passage for connecting the first and
`ister, a communication passage for connecting the first and
`second adsorbent accommodating spaces to each other, a
`second adsorbent accommodating spaces to each other, a
`control valve provided in the communication passage, and a
`control valve provided in the communication passage, and a
`control means for causing the first and second adsorbent
`control means for causing the first and second adsorbent
`accommodating spaces to be connected to each other by the
`accommodating spaces to be connected to each other by the
`control valve during refueling into the fuel tank.
`control valve during refueling into the fuel tank.
`With the first feature, it is possible to insure a sufficient
`With the first feature, it is possible to insure a sufiicient
`adsorbent capacity by using both the adsorbent accommo
`adsorbent capacity by using both the adsorbent accommo-
`dating spaces during refueling when a large amount of
`dating spaces during refueling when a large amount of
`evaporative fuel is generated, and to prevent the evaporative
`evaporative fuel is generated, and to prevent the evaporative
`fuel from being released to the atmosphere.
`fuel from being released to the atmosphere.
`In addition to the first feature, according to a second
`In addition to the first feature, according to a second
`aspect and feature of the present invention, the charge
`aspect and feature of the present invention,
`the charge
`passage comprises a first charge passage through which the
`passage comprises a first charge passage through which the
`evaporative fuel generated during a time other than refueling
`evaporative fuel generated during a time other than refueling
`is guided to the second adsorbent accommodating space, and
`is guided to the second adsorbent accommodating space, and
`a second charge passage through which the evaporative fuel
`a second charge passage through which the evaporative fuel
`generated during refueling is guided to the first adsorbent
`generated during refueling is guided to the first adsorbent
`accommodating space.
`accommodating space.
`With the second feature, it is possible to increase the
`With the second feature, it is possible to increase the
`adsorption efficiency of the adsorbent accommodated in
`adsorption efiiciency of the adsorbent accommodated in
`each of the adsorbent accommodating spaces.
`each of the adsorbent accommodating spaces.
`In addition to the first feature, according to a third aspect
`In addition to the first feature, according to a third aspect
`and feature of the present invention, the control means
`and feature of the present invention,
`the control means
`causes the first and second adsorbent accommodating spaces
`causes the first and second adsorbent accommodating spaces
`
`

`

`5,456,237
`5,456,237
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`10
`10
`
`15
`15
`
`20
`20
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`25
`25
`
`3
`3
`to be put into communication with each other by the control
`to be put into communication with each other by the control
`valve during releasing of the evaporative fuel from the
`valve during releasing of the evaporative fuel from the
`canister.
`canister.
`With the third feature, in releasing the evaporative fuel
`With the third feature, in releasing the evaporative fuel
`from the canister, the first and second adsorbent accommo-
`from the canister, the first and second adsorbent accommo
`dating spaces are put into communication with each other by
`dating spaces are put into communication with each other by
`the control valve and therefore, it is possible to release the
`the control valve and therefore, it is possible to release the
`adsorbed fuels in both the adsorbent accommodating spaces
`adsorbed fuels in both the adsorbent accommodating spaces
`together,
`together.
`In addition to the first feature, according to a fourth aspect
`In addition to the first feature, according to a fourth aspect
`and feature of the present invention, the control means
`and feature of the present invention,
`the control means
`causes the first and second adsorbent accommodating spaces
`causes the first and second adsorbent accommodating spaces
`to be put out of communication with each other by the
`to be put out of communication with each other by the
`control valve during parking of the vehicle.
`control valve during parking of the vehicle.
`With the fourth feature, it is possible to prevent the
`With the fourth feature,
`it is possible to prevent the
`evaporative fuel from being diffused from the first adsorbent
`evaporative fuel from being diffused from the first adsorbent
`accommodating space having a higher concentration of
`accommodating space having a higher concentration of
`evaporative fuel adsorbed into the second adsorbent accom
`evaporative fuel adsorbed into the second adsorbent accom-
`modating space having a lower concentration of evaporative
`modating space having a lower concentration of evaporative
`fuel adsorbed, and to prevent the evaporative fuel from
`fuel adsorbed, and to prevent the evaporative fuel from
`being released from the second adsorbent accommodating
`being released from the second adsorbent accommodating
`space to the atmosphere during traveling of the vehicle.
`space to the atmosphere during traveling of the vehicle.
`In addition to the first feature, according to a fourth aspect
`In addition to the first feature, according to a fourth aspect
`and feature of the present invention, the adsorbent accom
`and feature of the present invention, the adsorbent accom-
`modated in the first adsorbent accommodating space has a
`modated in the first adsorbent accommodating space has a
`characteristic that is liable to adsorb high boiling point
`characteristic that is liable to adsorb high boiling point
`components of the fuel, and the adsorbent accommodated in
`components of the fuel, and the adsorbent accommodated in
`the second adsorbent accommodating space has a charac
`the second adsorbent accommodating space has a charac-
`teristic that is liable to adsorb lowly-boiling components of
`teristic that is liable to adsorb lowly-boiling components of
`the fuel.
`the fuel.
`With the fifth feature, it is possible to effectively adsorb
`With the fifth feature, it is possible to effectively adsorb
`any of the highly- and lowly-boiling components of the fuel.
`any of the highly- and lowly-boiling components of the fuel.
`The above and other objects, features and advantages of
`The above and other objects, features and advantages of
`the invention will become apparent from the following
`the invention will become apparent from the following
`description of preferred embodiments taken in conjunction
`description of preferred embodiments taken in conjunction
`with the accompanying drawings.
`with the accompanying drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`BRIEF DESCRIPTION OF THE DRAWENGS
`FIG. 1 is an illustration of the entire arrangement of an
`FIG. 1 is an illustration of the entire arrangement of an
`evaporative fuel processing device according to a first
`evaporative fuel processing device according to a first
`embodiment of the present invention;
`embodiment of the present invention;
`FIGS. 2A-2E are views for explaining the operation of
`FIGS. 2A—2E are views for explaining the operation of
`the first embodiment;
`the first embodiment;
`FIG. 3 is an illustration of the entire arrangement of an
`FIG. 3 is an illustration of the entire arrangement of an
`evaporative fuel processing device according to a second
`evaporative fuel processing device according to a second
`embodiment of the present invention;
`embodiment of the present invention;
`FIGS. 4A-4B are views for explaining the operation of
`FIGS. 4A—4B are views for explaining the operation of
`the second embodiment;
`the second embodiment;
`FIG. 5 is an illustration of the entire arrangement of a
`FIG. 5 is an illustration of the entire arrangement of a
`prior art evaporative fuel processing device;
`prior art evaporative fuel processing device;
`FIG. 6 is an illustration of the entire arrangement of
`FIG. 6 is an illustration of the entire arrangement of
`another prior art evaporative fuel processing device;
`another prior art evaporative fuel processing device;
`FIGS. 7A-7D are views for explaining the operation of
`FIGS. 7A—7D are views for explaining the operation of
`the prior art device shown in FIG. 5.
`the prior art device shown in FIG. 5.
`DESCRIPTION OF THE PREFERRED
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`EMBODIMENTS
`The present invention will now be described by way of
`The present invention will now be described by way of
`preferred embodiments in connection with the accompany
`preferred embodiments in connection with the accompany-
`ing drawings.
`ing drawings.
`As shown in FIG. 1 illustrating a first embodiment, a fuel
`As shown in FIG. 1 illustrating a first embodiment, a fuel
`pumped from a fuel tank Tthrough a filter 1 and a fuel pump
`pumped from a fuel tank T through a filter 1 and a fuel pump
`2 is supplied through a feed passage 3 to a fuel injection
`2 is supplied through a feed passage 3 to a fuel injection
`
`4
`4
`valve 4 of an internal combustion engine E. An upper space
`valve 4 of an internal combustion engine E. An upper space
`in the fuel tank T is connected with a downstream portion of
`in the fuel tankT is connected with a downstream portion of
`a throttle valve 6 provided in an intake passage 5 in the
`a throttle valve 6 provided in an intake passage 5 in the
`internal combustion engine E by a first charge passage 7 and
`internal combustion engine E by a first charge passage 7 and
`a purge passage 8 between which a canister C is interposed.
`a purge passage 8 between which a canister C is interposed.
`An upper end of a filler tube 9 for supplying an oil to the fuel
`An upper end of a filler tube 9 for supplying an oil to the fuel
`tank T is connected with the internal space in the fuel tank
`tank T is connected with the internal space in the fuel tank
`T through a breather tube 10. The breather tube 10 is
`T through a breather tube 10. The breather tube 10 is
`connected at its upper end to the canister C through a fuel
`connected at its upper end to the canister C through a fuel
`supply valve 11 opened for supplying the oil and a second
`supply valve 11 opened for supplying the oil and a second
`charge passage 12. A two-way valve 13 is provided in the
`charge passage 12. A two-way valve 13 is provided in the
`first charge passage 7, and a purge valve 14 comprising a
`first charge passage 7, and a purge valve 14 comprising a
`solenoid valve is provided in the purge passage 8.
`solenoid valve is provided in the purge passage 8.
`The two-way valve 13 is opened when the internal
`The two-way valve 13 is opened when the internal
`pressure in the fuel tank T is increased to exceed the
`pressure in the fuel
`tank T is increased to exceed the
`atmospheric pressure by a predetermined value and also
`atmospheric pressure by a predetermined value and also
`when the internal pressure in the fuel tank T is reduced to
`when the internal pressure in the fuel tank T is reduced to
`below the internal pressure in the canister C by another
`below the internal pressure in the canister C by another
`predetermined value, thereby put the fuel tank T and the
`predetermined value, thereby put the fuel tank T and the
`canister C into communication with each other. When the
`canister C into communication with each other. When the
`purge valve 14 is opened, the canister C and the intake
`purge valve 14 is opened, the canister C and the intake
`passage 5 are put into communication with each other, and
`passage 5 are put into communication with each other, and
`when the purge valve 14 is closed, the communication
`when the purge valve 14 is closed,
`the communication
`between the canister C and the intake passage 5 is blocked.
`between the canister C and the intake passage 5 is blocked.
`The canister Cincludes a first to fourth chambers C to C.
`The canister C includes a first to fourth chambers C1 to C4
`each having an adsorbent comprised of activated carbon
`each having an adsorbent comprised of activated carbon
`accommodated therein. The first and second chambers C1
`accommodated therein. The first and second chambers C.
`and C are partitioned from each other by a partition wall 15
`and C2 are partitioned from each other by a partition wall 15
`opened at its lower end, and the third and fourth chambers
`opened at its lower end, and the third and fourth chambers
`C and C are partitioned from each other by a partition wall
`C3 and C4 are partitioned from each other by a partition wall
`16 opened at its lower end. Further, the second and third
`16 opened at its lower end. Further, the second and third
`chambers C and C are partitioned from each other by a
`chambers C2 and C3 are partitioned from each other by a
`partition wall 17 having no opening. The first and second
`partition wall 17 having no opening. The first and second
`chambers C and C define a first adsorbent accommodating
`chambers C1 and C2 define a first adsorbent accommodating
`space of the present invention, and the third and fourth
`space of the present invention, and the third and fourth
`chambers C and C define a second adsorbent accommo
`chambers C3 and C4 define a second adsorbent accommo-
`dating space of the present invention.
`dating space of the present invention.
`An evaporative fuel generated from the fuel tank during
`An evaporative fuel generated from the fuel tank during
`refueling contains a large number of high boiling point
`refueling contains a large number of high boiling point
`components. An adsorbent suitable for adsorption of such
`components. An adsorbent suitable for adsorption of such
`high boiling point components is selected as the adsorbent in
`high boiling point components is selected as the adsorbent in
`each of the first and second chambers C and C for mainly
`each of the first and second chambers C1 and C2 for mainly
`adsorbing such evaporative fuel. In addition, an evaporative
`adsorbing such evaporative fuel. In addition, an evaporative
`fuel generated from the fuel tank during traveling or parking
`fuel generated from the fuel tank during traveling or parking
`of a vehicle contains a large number of low boiling point
`of a vehicle contains a large number of low boiling point
`components and therefore, an adsorbent suitable for adsorp
`components and therefore, an adsorbent suitable for adsorp-
`tion of such low boiling point components is selected as the
`tion of such low boiling point components is selected as the
`adsorbent in each of the third and fourth chambers C and
`adsorbent in each of the third and fourth chambers C3 and
`C. The amount of evaporative fuel generated during refu
`C4. The amount of evaporative fuel generated during refu-
`eling is larger than the amount of evaporative fuel generated
`eling is larger than the amount of evaporative fuel generated
`during traveling or parking of the vehicle and hence, the
`during traveling or parking of the vehicle and hence, the
`capacity of the adsorbent in each of the first and second
`capacity of the adsorbent in each of the first and second
`chambers C and C is set at a value larger than those of the
`chambers C1 and C2 is set at a value larger than those of the
`adsorbents in the third and fourth chambers C3 and C4.
`adsorbents in the third and fourth chambers C and C.
`Two ports a and b are provided in an upper portion of the
`Two ports a and b are provided in an upper portion of the
`first chamber C in the canister C. The port a is connected
`first chamber C1 in the canister C. The port a is connected
`to the second charge passage 12, and the port b is connected
`to the second charge passage 12, and the port b is connected
`to the purge passage 8. A port c provided in an upper portion
`to the purge passage 8. A port 0 provided in an upper portion
`of the second chamber C in the canister C and a port d
`of the second chamber C2 in the canister C and a port (1
`provided in an upper portion of the third chamber C are
`provided in an upper portion of the third chamber C3 are
`connected to each other by a communication passage 18. A
`connected to each other by a communication passage 18. A
`control valve 19 comprised of a solenoid valve is provided
`control valve 19 comprised of a solenoid valve is provided
`in the communication passage 18 for opening and closing
`in the communication passage 18 for opening and closing
`the latter. Further, a porte provided in an upper space of the
`the latter. Further, a port e provided in an upper space of the
`third chamber C is connected to the first charge passage 7,
`third chamber C3 is connected to the first charge passage 7,
`and a port f provided in an upper portion of the fourth
`and a port f provided in an upper portion of the fourth
`chamber C is opened to the atmosphere.
`chamber C4 is opened to the atmosphere.
`
`30
`30
`
`35
`35
`
`40
`40
`
`45
`45
`
`50
`50
`
`55
`55
`
`60
`60
`
`65
`65
`
`

`

`5,456,237
`5,456,237
`
`5
`5
`The control valve 19 provided in the communication
`The control valve 19 provided in the communication
`passage 18 is connected to an electronic control unit U. The
`passage 18 is connected to an electronic control unit U. The
`control valve 19 is opened during traveling of the vehicle
`control valve 19 is opened during traveling of the vehicle
`and during refueling to the fuel tank T and closed during
`and during refueling to the fuel tank T and closed during
`parking of the vehicle. The purge valve 14 provided in the
`parking of the vehicle. The purge valve 14 provided in the
`purge passage 8 is connected to the electronic control unitU,
`purge passage 8 is connected to the electronic control unit U,
`and opened during traveling of the vehicle and closed during
`and opened during traveling of the vehicle and closed during
`parking of the vehicle.
`parking of the vehicle.
`The operation of the first embodiment of the present
`The operation of the first embodiment of the present
`invention having the above-described constr