JP2022074666A - Evaporation fuel treatment device - Google Patents

Abstract

To early recover adsorption performance by improving desorption performance of each of a first canister and a second canister in an evaporation fuel treatment device having the first canister adsorbing evaporation fuel during refueling and the second canister adsorbing evaporation fuel during parking.SOLUTION: An evaporation fuel treatment device includes: a three-way valve 52 opening a first vapor passage 50 communicated with a first canister 30 from a fuel tank 13 during refueling and opening a second vapor passage 54 communicated with a second canister 40 from the fuel tank 13 during parking; and a purge valve 62 opening both purge passages 60, 64 communicated with an intake passage 15 from both of the canisters 30, 40 during purge. The evaporation fuel treatment device also includes: a first heater 76 capable of heating a first adsorbent 32 of the first canister 30; and a second heater 78 capable of heating a second adsorbent 42 of the second canister 40. A temperature of the first adsorbent 32 heated by the first heater 76 is higher than that of the second adsorbent 42 heated by the second heater 78.SELECTED DRAWING: Figure 1

Description

The techniques disclosed herein relate to evaporative fuel treatment equipment. More specifically, the present invention relates to an evaporative fuel processing device that purges evaporative fuel generated in a fuel tank of a vehicle such as an automobile into an intake passage of an internal combustion engine.

Conventionally, for example, there is an evaporative fuel processing apparatus described in Patent Document 1. The evaporative fuel processing device is for operation, which has a canister for refueling having an adsorbent for adsorbing evaporative fuel generated in the fuel tank during refueling and an adsorbent for adsorbing evaporative fuel generated in the fuel tank during operation of the internal combustion engine. Equipped with a canister. Evaporated fuel (vapor) generated in the fuel tank during refueling is adsorbed on the adsorbent of the canister for refueling. Further, the evaporated fuel generated in the fuel tank during the operation of the internal combustion engine is adsorbed on the adsorbent of the canister for operation.

Japanese Unexamined Patent Publication No. 63-143374

By the way, it is effective to heat the adsorbent in order to recover the adsorbent performance at an early stage by improving the desorption performance of the adsorbent. Further, the suitable temperature for improving the desorption performance of the canister for refueling and the canister for operation is different. However, in the conventional example, no measures have been taken to improve the desorption performance of the adsorbents of the canister for refueling and the canister for operation to recover the adsorbent performance at an early stage.

The problem to be solved by the technique disclosed herein is an evaporative fuel treatment comprising a first canister that adsorbs the evaporative fuel of the fuel tank during refueling and a second canister that adsorbs the evaporative fuel of the fuel tank during parking. The purpose of the apparatus is to improve the desorption performance of each of the first canister and the second canister in order to recover the adsorption performance at an early stage.

In order to solve the above problems, the techniques disclosed in the present specification take the following means.

The first means is an evaporative fuel processing device that purges the evaporative fuel generated in the fuel tank of the vehicle into the intake passage of the internal combustion engine, and has a first adsorbent that adsorbs the evaporative fuel of the fuel tank at the time of refueling. The fuel is provided by opening a canister, a second canister having a second adsorbent that adsorbs the evaporated fuel of the fuel tank when parked, and a first vapor passage that communicates from the fuel tank to the first canister at the time of refueling. A switching means for closing the first vapor passage and opening the second vapor passage at the time of parking while closing the second vapor passage communicating from the tank to the second canister, and the intake passage from the first canister at the time of purging. A first purge passage communicating with the fuel and a second purge passage communicating from the second canister to the intake passage are opened, while a purge valve for closing the first purge passage and the second vapor passage is provided except during purging. A first heating means capable of heating the first adsorbent and a second heating means capable of heating the second adsorbent are provided, and the first adsorption by heating the first heating means is provided. The temperature of the material is higher than the temperature of the second adsorbent by heating of the second heating means, which is an evaporative fuel processing apparatus.

According to the first means, at the time of refueling, the first vapor passage is opened and the second vapor passage is closed by switching the switching means. Therefore, the evaporated fuel in the fuel tank can be adsorbed on the first adsorbent of the first canister. Further, at the time of parking, the first vapor passage is closed and the second vapor passage is opened by switching the switching means. Therefore, the evaporated fuel in the fuel tank can be adsorbed on the second adsorbent of the second canister. Further, at the time of purging, the first purge passage and the second purge passage are opened by opening the purge valve. Therefore, the evaporated fuel can be purged from the first canister and the second canister into the intake passage of the internal combustion engine.

Further, the temperature suitable for improving the desorption performance of the first adsorbent of the first canister is higher than the temperature suitable for improving the desorption performance of the second adsorbent of the second canister. Therefore, since the temperature of the first adsorbent of the first canister due to the heating of the first heating means is higher than the temperature of the second adsorbent due to the heating of the second heating means, the first adsorbent and the first adsorbent are used, respectively. It can be heated to a temperature suitable for improving the desorption performance. Therefore, it is possible to improve the desorption performance of each of the first canister and the second canister and to recover the adsorption performance at an early stage.

The second means is an evaporative fuel processing device of the first means, and the first heating means and the second heating means are evaporative fuel processing devices that utilize the heat of the exhaust system of the internal combustion engine.

According to the second means, it is not necessary to use a dedicated heating device.

The third means is the evaporative fuel processing apparatus of the first means, and the first heating means is a first heat storage material made of a phase change substance that exchanges heat with the first adsorbent, and the second. The heating means is a second heat storage material composed of a phase change substance that exchanges heat with the second adsorbent, and the first heat storage material has a phase change temperature higher than the phase change temperature of the second heat storage material. It is an evaporative fuel processing device.

According to the third means, the latent heat due to the phase change of the first heat storage material is used to suppress the temperature rise and temperature decrease of the first adsorbent, thereby adsorbing while improving the desorption performance of the first adsorbent. Performance can be improved. Further, by utilizing the latent heat due to the phase change of the second heat storage material to suppress the temperature rise and temperature decrease of the second adsorbent, the desorption performance of the second adsorbent is improved and the adsorption performance is improved. Can be done. Further, by accommodating the first heat storage material in the first canister, it is possible to suppress the increase in size of the first canister. Further, by accommodating the second heat storage material in the second canister, it is possible to suppress the increase in size of the second canister.

The fourth means is an evaporative fuel processing apparatus according to any one of the first to third means, wherein the adsorption capacity of the first canister is larger than the adsorption capacity of the second canister. ..

According to the fourth means, a large amount of evaporative fuel extruded from the fuel tank at the time of refueling can be collected by the first canister. Further, since the amount of evaporative fuel in the fuel tank during parking is smaller than that during refueling, the second canister can be downsized by making the adsorption capacity of the second canister smaller than the adsorption capacity of the first canister. can.

The fifth means is the evaporative fuel processing apparatus of any one of the first to the fourth means, and the first purge route including the first canister and the second purge route including the second canister are the same. It is an evaporative fuel processing device having ventilation resistance.

According to the fifth means, it is possible to equalize the purge amount of the evaporated fuel purged from the first canister and the second canister at the time of purging.

According to the technique disclosed herein, a first evaporative fuel processing apparatus comprising a first canister that adsorbs evaporative fuel in the fuel tank during refueling and a second canister that adsorbs evaporative fuel in the fuel tank during parking. It is possible to improve the desorption performance of each of the canister and the second canister and to recover the adsorption performance at an early stage.

It is a block diagram which shows the evaporative fuel processing apparatus which concerns on Embodiment 1. It is sectional drawing which shows the turbocharger and both canisters which concerns on Embodiment 2. FIG. FIG. 2 is a cross-sectional view taken along the line III-III in FIG. It is a side view which shows the 1st canister. It is a side view which shows the 2nd canister. It is a front view which shows the turbocharger and both canisters which concerns on Embodiment 3. FIG. It is a side view which shows the exhaust pipe and both canisters which concerns on Embodiment 4. FIG. It is a block diagram which shows the evaporative fuel processing apparatus which concerns on Embodiment 5.

Hereinafter, embodiments for carrying out the techniques disclosed in the present specification will be described with reference to the drawings.

[Embodiment 1]
The evaporative fuel processing device according to the present embodiment is mounted on a vehicle such as an automobile equipped with an internal combustion engine (engine). FIG. 1 is a block diagram showing an evaporative fuel processing apparatus.

(Configuration of evaporative fuel processing equipment)
As shown in FIG. 1, the engine system 10 of the vehicle is provided with an evaporative fuel processing device 20. The engine system 10 includes an engine 12 which is an internal combustion engine, and a fuel tank 13 for storing fuel supplied to the engine 12. An air cleaner 16, a throttle device 17, and the like are provided in the intake passage 15 leading to the engine 12. The evaporative fuel processing device 20 includes a first canister 30 and a second canister 40 that collect the evaporative fuel (vapor) generated in the fuel tank 13.

The first canister 30 is formed by filling the first canister case 31 with the first adsorbent 32. The first adsorbent 32 is made of activated carbon capable of adsorbing evaporative fuel. The first canister case 31 has a tank port 31a, a purge port 31b, and an atmospheric port 31c.

One end of the first atmospheric passage 34 is connected to the atmospheric port 31c, and the other end of the atmospheric passage 34 is open to the atmosphere via the first air filter 35. A first on-off valve 37 for opening and closing the atmospheric passage 34 is provided in the middle of the first atmospheric passage 34. The first on-off valve 37 is composed of a solenoid valve.

The second canister 40 is formed by filling the second canister case 41 with the second adsorbent 42. The second adsorbent 42 is made of activated carbon capable of adsorbing evaporative fuel. The second canister case 41 has a tank port 41a, a purge port 41b, and an atmospheric port 41c. The first adsorbent 32 and the second adsorbent 42 may be the same adsorbent or different adsorbents.

One end of the second atmospheric passage 44 is connected to the atmospheric port 41c, and the other end of the atmospheric passage 44 is open to the atmosphere via the second air filter 45. A second on-off valve 47 for opening and closing the atmospheric passage 44 is provided in the middle of the second atmospheric passage 44. The second on-off valve 47 is composed of a solenoid valve.

The adsorption capacity of the first canister 30 is larger than the adsorption capacity of the second canister 40. For example, the adsorption capacity of the first canister 30 is set to 2 to 6 times the adsorption capacity of the second canister 40.

The fuel tank 13 and the first canister 30 are communicated with each other via a first vapor passage 50 that guides the evaporated fuel (vapor) of the fuel tank 13 to the first canister 30. Further, the fuel tank 13 and the second canister 40 are communicated with each other via a second vapor passage 54 that guides the evaporated fuel (vapor) of the fuel tank 13 to the second canister 40.

The first vapor passage 50 includes a three-way valve 52, a tank-side vapor passage portion 55, and a first canister-side vapor passage portion 56. The three-way valve 52 is an electromagnetic three-way valve and has an inlet 52a, a first outlet 52b, and a second outlet 52c. The three-way valve 52 is configured to be switchable between a first communication state in which the inlet 52a and the first outlet 52b communicate with each other and a second communication state in which the inlet 52a and the second outlet 52c communicate with each other. The three-way valve 52 corresponds to the "switching means" as used herein.

One end of the tank-side vapor passage 55 is connected to the fuel tank 13, and the other end of the vapor passage 55 is connected to the inlet 52a of the three-way valve 52. One end of the vapor passage portion 56 on the first canister side is connected to the first outlet 52b of the three-way valve 52, and the other end of the vapor passage portion 56 is connected to the tank port 31a of the first canister 30.

The second vapor passage 54 includes a three-way valve 52, a tank-side vapor passage portion 55, and a second canister-side vapor passage portion 58. The three-way valve 52 and the tank-side vapor passage portion 55 are shared by both vapor passages 50 and 54. One end of the vapor passage portion 58 on the second canister side is connected to the second outlet 52c of the three-way valve 52, and the other end of the vapor passage portion 58 is connected to the tank port 41a of the second canister 40.

The first canister 30 and the intake passage 15 communicate with each other via a first purge passage 60 that guides the evaporated fuel collected in the first canister 30 to the intake passage 15. The second canister 40 and the intake passage 15 communicate with each other via a second purge passage 64 that guides the evaporated fuel collected in the second canister 40 to the intake passage 15.

The first purge passage 60 includes a first canister side purge passage portion 65 and an intake passage side purge passage portion 66. One end of the first canister side purge passage 65 is connected to the purge port 31b of the first canister 30, and the other end of the purge passage 65 is connected to one end of the intake passage side purge passage 66. The other end of the intake passage side purge passage portion 66 is connected to the intake passage 15 (specifically, the passage portion on the downstream side of the throttle device 17). A purge valve 62 for opening and closing the purge passage portion 66 is provided in the middle of the intake passage side purge passage portion 66. The purge valve 62 is composed of a solenoid valve. The purge valve 62 is opened at the time of purging and closed at a time other than the time of purging.

The second purge passage 64 includes a second canister side purge passage portion 68 and an intake passage side purge passage portion 66. The intake passage side purge passage portion 66 including the purge valve 62 is shared by both purge passages 60 and 64. One end of the second canister side purge passage portion 68 is connected to the purge port 41b of the second canister 40, and the other end of the purge passage portion 68 is connected to one end of the intake passage side purge passage portion 66.

The first on-off valve 37, the second on-off valve 47, the three-way valve 52, and the purge valve 62 are controlled by an electronic control unit (ECU) 70 for controlling the engine 12. The ECU 70 corresponds to the "control means" as used herein.

The path including the first atmospheric passage 34, the first canister 30, and the first purge passage 60 involved in the air flow during purging is referred to as the first purge passage 72. Further, a path including the second atmospheric passage 44, the second canister 40, and the second purge passage 64 that are involved in the air flow during purging is referred to as a second purge passage 74. The first purge path 72 and the second purge path 74 have the same ventilation resistance. Both purge paths 72 and 74 are set to have the same (including substantially the same) ventilation resistance by, for example, adjusting the passage cross-sectional area of the pipe.

A first heater 76 including an electric heater is provided on the outer side of the first canister case 31 of the first canister 30. A second heater 78 made of an electric heater capable of heating the second adsorbent 42 is provided on the outer side of the second canister case 41 of the second canister 40. The electric power supplied to the first heater 76 and the second heater 78 is controlled by the ECU 70. Further, the temperature of the first adsorbent 32 by heating the first heater 76 is set to be higher than the temperature of the second adsorbent 42 by heating the second heater 78. This is because the temperature suitable for improving the desorption performance of the first adsorbent 32 of the first canister 30 is higher than the temperature suitable for improving the desorption performance of the second adsorbent 42 of the second canister 40. Due to the high price. The first heater 76 corresponds to the "first heating means" as used herein. The second heater 78 corresponds to the "second heating means" as used herein.

(Operation of Evaporative Fuel Processing Device 20)
Next, the operation of the evaporated fuel processing device 20 will be described.
(1) During parking While parking (engine is stopped), the three-way valve 52 is maintained in the second communication state. Further, the purge valve 62 is maintained in the closed state. Further, the first on-off valve 37 is maintained in the closed state. Further, the second on-off valve 47 is maintained in the valve open state. As a result, the evaporated fuel in the fuel tank 13 is adsorbed on the second adsorbent 42 of the second canister 40 via the second vapor passage 54. The residual air from which vapor has been removed by the adsorption is released into the atmosphere through the second atmospheric passage 44.

(2) During refueling During refueling, the ECU 70 opens the first on-off valve 37, closes the second on-off valve 47, and switches the three-way valve 52 to the first communication state from the parked state. As a result, the evaporated fuel in the fuel tank 13 is adsorbed on the first adsorbent 32 of the first canister 30 via the first vapor passage 50. The residual air from which vapor has been removed by the adsorption is released into the atmosphere through the first atmospheric passage 34.

When refueling is completed, the ECU 70 closes the first on-off valve 37, opens the second on-off valve 47, and switches the three-way valve 52 to the second communication state. That is, it returns to the parked state. Further, the ECU 70 determines the start and end of refueling based on, for example, a signal from a lid switch that detects the opening and closing of the fuel lid of the vehicle.

(3) During purging During engine operation, that is, during purging, the ECU 70 maintains the first on-off valve 37 and the second on-off valve 47 in the valve open state, the three-way valve 52 in the second communication state, and the purge valve 62. The valve is kept closed. As a result, the evaporated fuel adsorbed on the first canister 30 and the second canister 40 is purged. That is, air is sucked into the first canister 30 from the first air passage 34 by the intake negative pressure of the engine 12, and is desorbed from the first adsorbent 32 of the first canister 30 by utilizing the air flow due to the suction. The evaporated fuel is purged to the intake passage 15 via the first purge passage 60. At the same time, air is sucked into the second canister 40 from the second air passage 44 by the intake negative pressure of the engine 12, and is desorbed from the second adsorbent 42 of the second canister 40 by utilizing the air flow due to the suction. The evaporated fuel is purged to the intake passage 15 via the second purge passage 64.

(Action / effect of Embodiment 1)
According to the evaporative fuel processing device 20, at the time of refueling, the first vapor passage 50 is opened and the second vapor passage 54 is closed by switching the three-way valve 52. Therefore, the evaporated fuel in the fuel tank 13 can be adsorbed on the first adsorbent 32 of the first canister 30.

Further, when parking, the first vapor passage 50 is closed and the second vapor passage 54 is opened by switching the three-way valve 52. Therefore, the evaporated fuel in the fuel tank 13 can be adsorbed on the second adsorbent 42 of the second canister 40.

Further, at the time of purging, the first purge passage 60 and the second purge passage 64 are opened by opening the purge valve 62. Therefore, the evaporated fuel can be purged from the first canister 30 and the second canister 40 to the intake passage 15 of the engine 12.

Further, since the temperature of the first adsorbent 32 of the first canister 30 is higher than the temperature of the second adsorbent 42 due to the heating of the second heater 78 due to the heating of the first heater 76, the first adsorbent 32 and the first adsorbent 32 are heated. Each of the adsorbents 32 can be heated to a temperature suitable for improving the desorption performance. Therefore, it is possible to improve the desorption performance of each of the first canister 30 and the second canister 40 and to recover the adsorption performance at an early stage.

As a result, it is possible to improve the so-called ORVR (Onboard Refueling Vapor Recovery) performance, which is the recovery function of vapor during refueling, and the DBL (diurnal breathing Loss) performance of the evaporated fuel released into the atmosphere from parked vehicles. can. This is suitable for vehicles having a small purge amount, for example, supercharged vehicles, hybrid vehicles and the like.

Further, since the adsorption capacity of the first canister 30 is larger than the adsorption capacity of the second canister 40, a large amount of evaporated fuel extruded from the fuel tank 13 at the time of refueling can be collected by the first canister 30. Further, since the amount of evaporative fuel in the fuel tank 13 during parking is smaller than that during refueling, the second canister 40 is made smaller by making the adsorption capacity of the second canister 40 smaller than the adsorption capacity of the first canister 30. Can be transformed into.

Further, the first purge path 72 including the first canister 30 and the second purge path 74 including the second canister 40 have the same ventilation resistance. Therefore, at the time of purging, the purging amount of the evaporated fuel purged from the first canister 30 and the second canister 40 can be equalized.

Further, the first heater 76 may be arranged in the first canister case 31. Further, the second heater 78 may be arranged in the second canister case 41. Further, the first heater 76 and / or the second heater 78 may be changed to other heating equipment.

[Embodiment 2]
Since this embodiment is a modification of the first embodiment, the modified portion will be described, and the same parts as those in the first embodiment will be designated by the same reference numerals and duplicated description will be omitted. In the present embodiment, in a vehicle evaporative fuel processing device 20 (see FIG. 1) including a supercharger (turbocharger) that compresses intake air by utilizing the flow of exhaust gas, the heat of the exhaust system of the engine, that is, the turbine of the turbocharger The heat of the housing is used to heat the first canister and the second canister. 2 is a cross-sectional view showing the turbocharger and both canisters, FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2, FIG. 4 is a side view showing the first canister, and FIG. 5 is a side view showing the second canister. be. The parts to be changed in the second embodiment are designated by reference numerals in the 100s.

As shown in FIG. 2, the turbocharger 100 has a compressor housing 101, a turbine housing 102, and a bearing housing 103. The compressor housing 101 and the turbine housing 102 are concentrically connected via the bearing housing 103. The compressor housing 101 is provided in the middle of the intake passage 115. The turbine housing 102 is provided in the middle of the exhaust passage 118. A connecting shaft 105 is rotatably supported in the bearing housing 103.

The compressor wheel 107 is arranged in the compressor housing 101. Further, the turbine wheel 108 is arranged in the turbine housing 102. The compressor wheel 107 and the turbine wheel 108 are concentrically connected via a connecting shaft 105. As the turbine wheel 108 is rotated by the flow of exhaust gas, the compressor wheel 107 is rotated via the connecting shaft 105, so that the intake air is compressed.

The turbine housing 102 has a cylindrical peripheral wall portion 102a that concentrically surrounds the turbine wheel 108. The first canister 130 and the second canister 140 are arranged point-symmetrically about the axis 102L of the turbine housing 102 on the outer peripheral portion of the peripheral wall portion 102a (see FIG. 3).

As shown in FIGS. 3 and 4, the first canister case 131 of the first canister 130 is formed in a 1/4 cylindrical shape. The tank port 131a is arranged at one end in the circumferential direction of one end surface of the first canister case 131, and the purge port 131b is arranged at the other end. Atmospheric port 131c is arranged on the outer peripheral side of one end surface of the first canister case 131. The first canister case 131 is arranged concentrically with respect to the upper outer side of the peripheral wall portion 102a of the turbine housing 102 at a predetermined distance.

As shown in FIGS. 3 and 5, the second canister case 141 of the second canister 140 has basically the same configuration as the first canister case 131, and has a tank port 141a and a purge port 141b on one end surface thereof. And atmospheric port 141c is arranged. The axial length of the first canister case 131 (horizontal length in FIG. 4) is set longer than the axial length of the second canister case 141 (horizontal length in FIG. 5). As a result, the adsorption capacity of the first canister 130 is larger than the adsorption capacity of the second canister 140. The turbine housing 102 corresponds to the "first heating means" and "second heating means" as used herein.

The temperature of the first adsorbent (not shown) of the first canister 130 due to the heating of the turbine housing 102 is higher than the temperature of the second adsorbent (not shown) of the second canister 140 due to the heating of the turbine housing 102. The arrangement position, shape, and the like of the first canister case 131 and the second canister case 141 with respect to the peripheral wall portion 102a of the turbine housing 102 are set.

According to this embodiment, the first canister 130 and the second canister 140 are heated by using the heat of the turbine housing 102, so that it is not necessary to use a dedicated heating device. Further, in the first canister case 131 and the second canister case 141, the wall portion of the turbine housing 102 that receives heat may be formed of a metal material having good thermal conductivity, while the other walls may be formed of a resin material.

[Embodiment 3]
Since this embodiment is a modification of the second embodiment, the modified portion will be described, and the same parts as those of the second embodiment will be designated by the same reference numerals and duplicated description will be omitted. FIG. 6 is a front view showing a turbocharger and both canisters. As shown in FIG. 6, in the present embodiment, the first canister case 131 of the first canister 130 and the second canister case 141 of the second canister 140 in the second embodiment (see FIG. 3) are formed in a semi-cylindrical shape, respectively. It is a thing.

According to the present embodiment, the adsorption capacities of the first canister 130 and the second canister 140 can be increased as compared with the second embodiment (see FIG. 3). Further, the lengths of the first canister case 131 and the second canister case 141 in the circumferential direction may be set to different lengths.

[Embodiment 4]
Since this embodiment is a modification of the second embodiment, the modified portion will be described, and the same parts as those in the first embodiment will be designated by the same reference numerals and duplicated description will be omitted. In this embodiment, the heat of the exhaust system of the engine 12 of the vehicle, that is, the heat of the exhaust pipe is used to heat the first canister and the second canister. FIG. 7 is a side view showing the exhaust pipe and both canisters. The parts to be changed in the fourth embodiment are designated by reference numerals in the 200 series.

As shown in FIG. 7, in the present embodiment, the turbine housing 102 of the second embodiment (see FIGS. 2 and 3) is changed to a cylindrical exhaust pipe 202. Further, the first canister 230 and the second canister 240 are arranged side by side in the axial direction of the exhaust pipe 202 at predetermined intervals. Further, in the case of the present embodiment, the first canister case 231 and the second canister case 241 are formed in a cylindrical shape. The exhaust pipe 202 corresponds to the "first heating means" and the "second heating means" referred to in the present specification.

The temperature of the first adsorbent (not shown) of the first canister 230 due to the heating of the exhaust pipe 202 is higher than the temperature of the second adsorbent (not shown) of the second canister 240 due to the heating of the exhaust pipe 202. , The arrangement position, shape, etc. of the first canister case 231 and the second canister case 241 with respect to the exhaust pipe 202 are set.

The same actions and effects as those of the second embodiment can be obtained by this embodiment as well. Further, the adsorption capacity of the first canister 130 and the second canister 140 can be increased as compared with the second embodiment (see FIG. 3).

Further, the first canister case 231 and the second canister case 241 may be formed into a semi-cylindrical shape, a 1/4 cylindrical shape, a C-shaped cylindrical shape, or the like, respectively. Further, the lengths of the first canister case 231 and the second canister case 241 in the circumferential direction may be set to different lengths. Further, the first canister case 231 and the second canister case 241 may be arranged side by side in the circumferential direction of the exhaust pipe 202.

Further, the turbine housing 102 and the exhaust pipe 202 may be changed to other members that generate exhaust heat.

[Embodiment 5]
Since this embodiment is a modification of the first embodiment, the modified portion will be described, and the same parts as those in the first embodiment will be designated by the same reference numerals and duplicated description will be omitted. FIG. 8 is a block diagram showing an evaporative fuel processing apparatus. The parts to be changed in the fifth embodiment are designated by reference numerals in the 300 series.

As shown in FIG. 8, in the present embodiment, the first canister case 31 of the first canister 30 is filled with the first adsorbent 32 and the first heat storage material 338 mixedly. The first heat storage material 338 is composed of a granular phase changing substance that exchanges heat with the first adsorbent 32. The first heat storage material 338 corresponds to the "first heating means" as used herein. Further, the first adsorbent 32 and the first heat storage material 338 may be kneaded.

The second adsorbent 42 and the second heat storage material 348 are mixed and filled in the second canister case 41 of the second canister 40. The second heat storage material 348 is composed of a granular phase changing substance that exchanges heat with the second adsorbent 42. The second heat storage material 348 corresponds to the "second heating means" referred to in the present specification. Further, the second adsorbent 42 and the second heat storage material 348 may be kneaded.

The phase change temperature, that is, the melting point of the second heat storage material 348 is, for example, 18 ° C. Further, the phase change temperature, that is, the melting point of the first heat storage material 338 has a temperature higher than the melting point of the second heat storage material 348, for example, 40 ° C.

According to the present embodiment, the latent heat due to the phase change of the first heat storage material 338 is used to suppress the temperature rise and temperature decrease of the first adsorbent 32, thereby improving the desorption performance of the first adsorbent 32. At the same time, the adsorption performance can be improved. Further, by utilizing the latent heat due to the phase change of the second heat storage material 348 to suppress the temperature rise and temperature decrease of the second adsorbent 42, the desorption performance of the second adsorbent 42 is improved and the adsorption performance is improved. Can be improved. Further, by accommodating the first heat storage material 338 in the first canister 30, it is possible to suppress the increase in size of the first canister 30. Further, by accommodating the second heat storage material 348 in the second canister 40, it is possible to suppress the increase in size of the second canister 40.

[Other embodiments]
The techniques disclosed herein are not limited to the embodiments described above, and can be implemented in various other embodiments. For example, the first on-off valve 37 and / or the second on-off valve 47 of the evaporative fuel processing device 20 may be omitted. Further, as the first heating means and / or the second heating means, at least two of a heating device, a member that generates exhaust heat, and a heat storage material may be used in combination.

12 engine (internal combustion engine)
13 Fuel tank 15 Intake passage 20 Evaporative fuel processing device 30 1st canister 31 1st canister case 32 1st adsorbent 40 2nd canister 41 2nd canister case 42 2nd adsorbent 50 1st vapor passage 52 Three-way valve (switching means) )
54 Second vapor passage 60 First purge passage 62 Purge valve 64 Second purge passage 70 ECU (control means)
72 1st purge path 74 2nd purge path 76 1st heater (1st heating means)
78 Second heater (second heating means)
100 Turbocharger 102 Turbine housing (1st heating means, 2nd heating means)
102a Peripheral wall 130 1st canister 131 1st canister case 140 2nd canister 141 2nd canister case 202 Exhaust pipe (1st heating means, 2nd heating means)
230 1st canister 231 1st canister case 240 2nd canister 241 2nd canister case 338 1st heat storage material (1st heating means)
348 Second heat storage material (second heating means)

Claims (5)

An evaporative fuel processing device that purges the evaporative fuel generated in the fuel tank of a vehicle into the intake passage of an internal combustion engine.
A first canister having a first adsorbent that adsorbs the evaporated fuel of the fuel tank at the time of refueling,
A second canister having a second adsorbent that adsorbs the evaporated fuel of the fuel tank when parking.
At the time of refueling, the first vapor passage communicating from the fuel tank to the first canister is opened, and at the same time, the second vapor passage communicating from the fuel tank to the second canister is closed, while at the time of parking, the first vapor passage is opened. A switching means for opening the second vapor passage at the same time as closing,
At the time of purging, the first purge passage communicating from the first canister to the intake passage and the second purge passage communicating from the second canister to the intake passage are opened, while the first purge passage and the second purge passage are opened except during purging. A purge valve that closes the vapor passage and
Equipped with
A first heating means capable of heating the first adsorbent and a second heating means capable of heating the second adsorbent are provided.
An evaporative fuel treatment apparatus in which the temperature of the first adsorbent by heating the first heating means is higher than the temperature of the second adsorbent by heating the second heating means. The evaporative fuel processing apparatus according to claim 1.
The first heating means and the second heating means are evaporative fuel processing devices that utilize the heat of the exhaust system of the internal combustion engine. The evaporative fuel processing apparatus according to claim 1.
The first heating means is a first heat storage material made of a phase changing substance that exchanges heat with the first adsorbent.
The second heating means is a second heat storage material made of a phase changing substance that exchanges heat with the second adsorbent.
The first heat storage material is an evaporative fuel treatment apparatus having a phase change temperature higher than the phase change temperature of the second heat storage material. The evaporative fuel processing apparatus according to any one of claims 1 to 3.
An evaporative fuel processing device in which the adsorption capacity of the first canister is larger than the adsorption capacity of the second canister. The evaporative fuel processing apparatus according to any one of claims 1 to 4.
An evaporative fuel processing apparatus having the same ventilation resistance as the first purge path including the first canister and the second purge path including the second canister.

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