Evaporated fuel processing device

Abstract

To prevent steam from adhering to activated carbon of a canister.SOLUTION: In the evaporated fuel processing device 50 of the present invention, when the humidity acquired by the humidity sensor 60 is equal to or higher than the threshold value while the purge control for supplying the purge gas containing the evaporated fuel purged from the canister 52 to the engine 10 is being performed, the control unit 70 controls the cooling device 57 to cool the air flowing into the canister 52 through the first open-to-atmosphere passage 55a, thereby preventing water vapor from adhering to the activated carbon of the canister 52.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an evaporated fuel treatment device. [Background technology]

[0002] A device is known that prevents evaporated fuel from being released into the atmosphere by adsorbing evaporated fuel generated in a fuel tank in a canister and supplying purge gas containing the purged evaporated fuel from the canister to the engine.

[0003] Patent Document 1 discloses an evaporated fuel processing mechanism that purges evaporated fuel adsorbed in a canister together with air into the intake system of an internal combustion engine via a purge valve. The evaporated fuel processing mechanism in Patent Document 1 is equipped with an air inlet passage that introduces air into the canister, and when purging evaporated fuel into the intake system, air is introduced into the canister through the air inlet passage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-60645 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the fuel vapor treatment mechanism of Patent Document 1, when humidity is high, such as on rainy days, it is expected that air containing a large amount of water vapor will flow into the canister through the air intake passage. If air containing a large amount of water vapor flows into the canister and a large amount of moisture adheres to the activated carbon in the canister, the canister's ability to adsorb and desorb fuel vapor may decrease.

[0006] The present invention has been made in view of the above-mentioned problems, and has as its object to prevent water vapor from adhering to activated carbon in a canister. [Means for solving the problem]

[0007] The present invention provides an evaporative fuel treatment device having a canister that temporarily adsorbs evaporative fuel in a fuel tank, an atmospheric open passage connected to the canister, a cooling device arranged on the atmospheric open passage and powered by power supplied from a battery, an acquisition means for acquiring humidity information of the outside air, and a control unit for controlling the cooling device, wherein the control unit is characterized in that when performing purge control to supply purge gas containing evaporative fuel purged from the canister to an internal combustion engine, if the humidity acquired by the acquisition means is above a threshold value, the control unit controls the cooling device to cool the air flowing into the canister through the atmospheric open passage. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent water vapor from adhering to the activated carbon of the canister. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a schematic configuration of a vehicle equipped with an evaporated fuel treatment device of a first embodiment. [Figure 2] 10 is a flowchart illustrating an example of processing by a control unit. [Figure 3] FIG. 10 is a diagram showing a schematic configuration of a vehicle equipped with an evaporated fuel treatment device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] In this embodiment of the present invention, an evaporated fuel treatment device 50 includes a canister 52 that temporarily adsorbs evaporated fuel in a fuel tank 40, a first atmosphere-open passage 55a that is connected to the canister 52, a cooling device 57 that is disposed in the first atmosphere-open passage 55a and is driven by power supplied from a battery 58, a humidity sensor 60 that acquires humidity information about the outside air, and a control unit 70 that controls the cooling device 57. When purge control is being performed to supply purge gas containing evaporated fuel purged from the canister 52 to the engine 10, if the humidity acquired by the humidity sensor 60 is equal to or higher than a threshold value, the control unit 70 controls the cooling device 57 to cool the air flowing into the canister 52 through the first atmosphere-open passage 55a. This prevents water vapor from adhering to the activated carbon in the canister 52. [Example]

[0011] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. <First Example> Fig. 1 is a diagram showing the schematic configuration of a vehicle equipped with an evaporated fuel treatment device 50 according to a first embodiment. Note that Fig. 1 is simplified for the sake of convenience in explaining this embodiment, and components that are normally included in a vehicle are assumed to be included even if they are not shown in the figure. The vehicle according to this embodiment includes an engine 10 as an internal combustion engine, an intake passage 20, an exhaust passage 30, a fuel tank 40, an evaporated fuel treatment device 50, and the like.

[0012] Engine 10 performs a series of strokes consisting of an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke. Engine 10 has a combustion chamber 12 in which a piston 11 is housed so that it can reciprocate, an ignition plug 13 disposed within combustion chamber 12, an intake valve 15 located between combustion chamber 12 and an intake port 14, and an exhaust valve 17 located between combustion chamber 12 and an exhaust port 16. The configuration of engine 10 is not particularly limited, and various known engines can be used.

[0013] The intake passage 20 is a passage that guides intake air taken in from outside the vehicle to the combustion chamber 12 via the intake port 14. The intake passage 20 is formed, for example, by an intake pipe. A fuel injector 21 is arranged in the intake passage 20.

[0014] The fuel injector 21 injects fuel pressure-fed from the fuel tank 40 into the intake passage 20. The fuel injector 21 adjusts the amount of fuel injected under the control of the control unit 70. Note that the fuel injector 21 is not limited to injecting fuel into the intake passage 20, and may be configured to inject fuel into the combustion chamber 12.

[0015] The exhaust passage 30 is a passage through which exhaust gas burned in the combustion chamber 12 is discharged to the outside air of the vehicle via the exhaust port 16. The exhaust passage 30 is formed by, for example, an exhaust pipe. Fuel tank 40 stores liquid fuel to be supplied to fuel injector 21. Note that, in fuel tank 40, evaporated fuel (vapor) is generated from the liquid fuel.

[0016] The vehicle also includes an evaporated fuel treatment device 50 for supplying evaporated fuel to the intake passage 20 without discharging it into the atmosphere. The evaporated fuel treatment device 50 includes a vapor passage 51, a canister 52, a purge passage 53, a first atmosphere release passage 55a, a second atmosphere release passage 55b, a humidity sensor 60, a control unit 70, and the like.

[0017] The vapor passage 51 is a passage that guides evaporated fuel generated in the fuel tank 40 to the canister 52. The vapor passage 51 is formed by a pipe that connects the fuel tank 40 and the canister 52 to each other. The canister 52 temporarily adsorbs the evaporated fuel generated in the fuel tank 40. The canister 52 has activated carbon therein as an adsorbent, and adsorbs the evaporated fuel that flows in from the fuel tank 40 through the vapor passage 51.

[0018] The purge passage 53 is a passage that supplies purge gas containing evaporated fuel purged from the canister 52 to the intake passage 20 of the engine 10. The purge passage 53 is formed by a pipe that connects the canister 52 and the intake passage 20. A purge valve 54 is disposed in the purge passage 53. The purge valve 54 adjusts the flow rate of purge gas supplied to the intake passage 20 through the purge passage 53. The purge valve 54 adjusts the flow rate of the purge gas based on the control of the control unit 70.

[0019] The first atmosphere release passage 55a and the second atmosphere release passage 55b are passages that communicate with the canister 52 and are open to the atmosphere. When purge gas is being supplied to the engine 10, air flows into the canister 52 through the first atmosphere release passage 55a. On the other hand, when purge gas is not being supplied to the engine 10 and evaporated fuel flows from the fuel tank 40 into the canister 52 in an amount that exceeds the adsorption capacity of the activated carbon in the canister 52, the evaporated fuel in the canister 52 is released through the second atmosphere release passage 55b.

[0020] Additionally, a first shut-off valve 56a and a second shut-off valve 56b are disposed in the first atmosphere release passage 55a and the second atmosphere release passage 55b, respectively. The first shut-off valve 56a and the second shut-off valve 56b close the passage to prevent air from flowing in from either the first atmosphere release passage 55a or the second atmosphere release passage 55b. That is, when the first shut-off valve 56a is closed to close the first atmosphere release passage 55a, the second shut-off valve 56b is opened to communicate between the canister 52 and the outside air through the second atmosphere release passage 55b. On the other hand, when the second shut-off valve 56b is closed to close the second atmosphere release passage 55b, the first shut-off valve 56a is opened to communicate between the canister 52 and the outside air through the first atmosphere release passage 55a. The first closing valve 56a and the second closing valve 56b open and close under the control of the control unit .

[0021] A cooling device 57 is disposed in the first atmosphere open passage 55a. The cooling device 57 cools the air flowing into the canister 52 through the first atmosphere-open passage 55a. The cooling device 57 is configured as a refrigerant cycle including a compressor that compresses the cooling water as a refrigerant, an electronic pressure regulating valve that adjusts the pressure to obtain a desired temperature, and the like. When the air flowing into the canister 52 through the first atmosphere-open passage 55a is humid, the cooling device 57 cools the air in the first atmosphere-open passage 55a, thereby condensing and removing the water vapor in the air.

[0022] The cooling device 57 is driven by power supplied from a battery 58 provided in the vehicle. Specifically, the battery 58 supplies the power necessary to drive the compressor of the cooling device 57 and to energize the electronic pressure regulating valve. The cooling device 57 is driven under the control of a control unit 70.

[0023] Further, a heat exchanger 59 is disposed in the first atmosphere open passage 55a. The heat exchanger 59 heats the air that has flowed into the canister 52 through the first atmosphere-open passage 55a and from which water vapor has been removed by the cooling device 57, by exchanging heat with the exhaust system. The heat exchanger 59 is disposed on the canister 52 side of the first atmosphere-open passage 55a relative to the cooling device 57. The heat exchanger 59 is configured by bringing a part of the exhaust passage 30 and a part of the first atmosphere-open passage 55a into close proximity. In this way, by being placed close to a part of the exhaust passage 30, the heat exchanger 59 can receive heat from the exhaust system.

[0024] The humidity sensor 60 acquires humidity information of the outside air and transmits the acquired humidity information to the control unit 70. The humidity sensor 60 is disposed near the opening of the first atmosphere open passage 55a, but may also be disposed near the opening of the second atmosphere open passage 55b.

[0025] The control unit 70 controls the entire vehicle. The control unit 70 can be, for example, an ECU (Electronic Control Unit). The control unit 70 has a hardware configuration including a CPU, ROM, RAM, etc. The ROM stores programs and predetermined information for controlling the engine 10, the evaporative fuel treatment device 50, etc. The RAM is a work memory that temporarily stores programs and data. The CPU reads out the programs stored in the ROM, expands them into the RAM, and executes them to control the engine 10, the evaporative fuel treatment device 50, etc.

[0026] In the evaporated fuel treatment device 50 configured as described above, evaporated fuel generated in the fuel tank 40 is guided to the canister 52 via the vapor passage 51 and temporarily adsorbed by the canister 52. When the engine 10 starts, the intake passage 20 becomes negative pressure, so that by opening the purge valve 54, purge gas containing evaporated fuel purged from the canister 52 is supplied to the intake passage 20 via the purge passage 53. The purge gas supplied to the intake passage 20 mixes with a mixture of intake air taken in through the intake passage 20 and fuel injected from the fuel injector 21, and then flows into the combustion chamber 12 of the engine 10. Therefore, the evaporated fuel contained in the purge gas is combusted in the combustion chamber 12, preventing the evaporated fuel from being released from the fuel tank 40 into the atmosphere.

[0027] Meanwhile, as the purge gas is supplied to the intake passage 20, a negative pressure is created inside the canister 52, causing air to flow into the canister 52 through the first atmosphere release passage 55a or the second atmosphere release passage 55b. At this time, if the air flowing into the canister 52 is humid, a large amount of water vapor will adhere to the activated carbon in the canister 52.

[0028] The control unit 70 of this embodiment controls each component of the evaporated fuel treatment device 50 so that water vapor does not adhere to the activated carbon in the canister 52. Specific processing by the control unit 70 will be described below with reference to the flowchart in Fig. 2. The flowchart in Fig. 2 is implemented by the ECU, which is the control unit 70, executing a program.

[0029] In S11, the control unit 70 determines whether or not the engine 10 has been started. If the engine 10 has been started in response to an instruction from a vehicle occupant, the control unit 70 proceeds to S12. On the other hand, if the engine 10 has not been started, the control unit 70 waits until the engine 10 is started.

[0030] In S12, the control unit 70 performs control so as not to drive the cooling device 57, and to close the first atmosphere release passage 55a and open the second atmosphere release passage 55b. Specifically, the control unit 70 performs control so as not to supply electricity from the battery 58 to the cooling device 57. The control unit 70 also performs control so as to close the first shut-off valve 56a and open the second shut-off valve 56b.

[0031] In S13, the control unit 70 determines whether purge control is being performed, in which purge gas containing evaporated fuel purged from the canister 52 is supplied to the intake passage 20 via the purge passage 53. Specifically, the control unit 70 determines that purge control is being performed if the purge valve 54 is open. On the other hand, the control unit 70 determines that purge control is not being performed if the purge valve 54 is closed. If purge control is being performed, the process proceeds to S14.

[0032] In S14, the control unit 70 receives humidity information from the humidity sensor 60 and acquires humidity information of the outside air. In S15, the control unit 70 determines whether the humidity is equal to or greater than a threshold value based on the acquired humidity information. The threshold value is set based on the humidity at which the adsorption performance of the canister 52 deteriorates. If the humidity is equal to or greater than the threshold value, the process proceeds to S16. If the humidity is less than the threshold value, the process proceeds to S17.

[0033] In S16, the control unit 70 controls the cooling device 57 to be driven, and to open the first atmosphere release passage 55a and close the second atmosphere release passage 55b. Specifically, the control unit 70 controls the cooling device 57 to be driven by supplying electricity from the battery 58. The control unit 70 also controls the first shut-off valve 56a to be opened and the second shut-off valve 56b to be closed.

[0034] Here, the process proceeds to S16 when purge control is being performed and the humidity is equal to or higher than the threshold value, so that the air flowing into the canister 52 is humid and water vapor is likely to adhere to the activated carbon in the canister 52. As in the process of S16, by opening the first atmosphere open passage 55a and driving the cooling device 57, the air flowing in from the first atmosphere open passage 55a can be cooled. Therefore, the water vapor in the air is condensed and removed from the air flowing in from the first atmosphere open passage 55a. By condensing and removing the water vapor in the air using the cooling device 57 in this way, it is possible to prevent water vapor from adhering to the activated carbon in the canister 52. Furthermore, the air from which water vapor has been removed by the cooling device 57 can be heated by the heat exchanger 59 on its way to the canister 52, thereby increasing its temperature. Therefore, heated air can be introduced into the canister 52, preventing the temperature of the activated carbon from decreasing.

[0035] On the other hand, in S17, the control unit 70 performs control so as not to drive the cooling device 57, and to open the first atmosphere release passage 55a and close the second atmosphere release passage 55b. Specifically, the control unit 70 performs control so as not to drive the cooling device 57 by not supplying electricity from the battery 58 to the cooling device 57. The control unit 70 also performs control so as to open the first shut-off valve 56a and close the second shut-off valve 56b.

[0036] Here, the process proceeds to S17 when purge control is being executed and the humidity is below the threshold value, so that the air flowing into the canister 52 is dry and water vapor is unlikely to adhere to the activated carbon in the canister 52. Therefore, even without opening the first atmosphere open passage 55a and driving the cooling device 57 as in the process of S17, it is possible to prevent water vapor from adhering to the activated carbon in the canister 52 due to the air flowing in from the first atmosphere open passage 55a. Furthermore, the air flowing in from the first atmosphere open passage 55a can be heated by the heat exchanger 59 along the way, thereby increasing its temperature. Therefore, heated air can be introduced into the canister 52, and the temperature of the activated carbon can be prevented from decreasing.

[0037] On the other hand, if it is determined in S13 that purge control is not being executed, the flow proceeds to S18. In S18, the control unit 70 performs control so as not to drive the cooling device 57, and to close the first atmosphere release passage 55a and open the second atmosphere release passage 55b. Specifically, the control unit 70 performs control so as not to drive the cooling device 57 by not supplying electricity from the battery 58 to the cooling device 57. The control unit 70 also performs control so as to close the first shut-off valve 56a and open the second shut-off valve 56b.

[0038] Here, the flow proceeds to S18 when purge control is not being performed and therefore no air is flowing into the canister 52. However, if evaporated fuel flows from the fuel tank 40 into the canister 52 in an amount greater than the adsorption capacity of the activated carbon in the canister 52, the evaporated fuel that cannot be adsorbed must be released into the atmosphere. In the process of S18, the second shut-off valve 56b is opened, and therefore the evaporated fuel that exceeds the adsorption capacity of the activated carbon is released through the second atmosphere release passage 55b. If the evaporated fuel is released through the first atmosphere release passage 55a, there is a possibility that the evaporated fuel will self-ignite in the high-temperature heat exchanger 59. Therefore, when purge control is not being performed, the evaporated fuel is released through the second atmosphere release passage 55b to prevent the evaporated fuel from self-igniting. After the processing of S16 to S18 is completed, the process returns to S13 and repeats the processing of S13 to S18 until the engine 10 is stopped.

[0039] As described above, according to this embodiment, when the control unit 70 is executing purge control to supply purge gas containing evaporated fuel purged from the canister 52 to the engine 10, if the humidity acquired by the humidity sensor 60 is equal to or higher than the threshold value, the control unit 70 controls the cooling device 57 to cool the air flowing into the canister 52 through the first atmosphere-open passage 55a. If there is a possibility that humid air will flow into the canister 52, the cooling device 57 condenses and removes water vapor from the air, thereby preventing the water vapor from adhering to the activated carbon of the canister 52. Therefore, the evaporated fuel adsorption and desorption performance of the canister 52 can be maintained without deterioration.

[0040] Furthermore, according to this embodiment, the evaporated fuel treatment device 50 includes a heat exchanger 59 disposed on the first atmosphere-open passage 55a and closer to the canister 52 than the cooling device 57, and which exchanges heat with the exhaust system. When the humidity acquired by the humidity sensor 60 is equal to or higher than a threshold value during purge control, the control unit 70 controls the first and second close valves 56a and 56b to allow air to flow in from the first atmosphere-open passage 55a and controls the cooling device 57 to cool the air flowing into the canister 52 through the first atmosphere-open passage 55a. If low-temperature air that has passed through the cooling device 57 flows into the canister 52, the temperature of the activated carbon may decrease, resulting in a decrease in the amount of carbon desorbed from the canister 52. Therefore, by providing the heat exchanger 59 in the first atmosphere-open passage 55a, which can heat the air that has passed through the cooling device 57 by heat exchange with the exhaust system, low-temperature air can be prevented from flowing into the canister 52.

[0041] Furthermore, according to this embodiment, when the humidity acquired by the humidity sensor 60 is below a threshold value during purge control, the control unit 70 controls the first and second shutoff valves 56a and 56b to allow air to flow in through the first atmosphere-open passage 55a, and also controls the cooling device 57 so as not to be energized. When a large amount of water vapor does not flow into the canister 52, the cooling device 57 is not energized, thereby preventing excess power consumption. Furthermore, by allowing air to flow in through the first atmosphere-open passage 55a having the heat exchanger 59, a decrease in the temperature of the activated carbon can be prevented, and the desorption performance of the canister 52 can be maintained.

[0042] Furthermore, according to this embodiment, when purge control is not being performed, the control unit 70 controls the first and second shutoff valves 56a and 56b so that the second atmosphere release passage 55b communicates with the outside air. In this way, when purge control is not being performed, the evaporated fuel is released through the second atmosphere release passage 55b instead of the first atmosphere release passage 55a, thereby preventing the evaporated fuel from self-igniting.

[0043] In the above-described embodiment, S17 is described as a case in which the cooling device 57 is not driven, and control is performed so that the first atmosphere release passage 55a is opened and the second atmosphere release passage 55b is closed. However, this is not a limitation. In S17, the control unit 70 may perform control so that the cooling device 57 is not driven, and the second atmosphere release passage 55b is opened and the first atmosphere release passage 55a is closed. The case in which the process proceeds to S17 is when the air flowing into the canister 52 is dry, and therefore, even if air is flowed in from the second atmosphere release passage 55b, water vapor can be prevented from adhering to the activated carbon in the canister 52.

[0044] <Second Example> In the first embodiment, the vapor passage 51 communicates between the fuel tank 40 and the canister 52. In this embodiment, the cooling device 57 is disposed midway along the vapor passage 81.

[0045] 3 is a diagram showing a schematic configuration of a vehicle equipped with an evaporated fuel treatment device 80 according to a second embodiment. Note that the same components as those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted as appropriate. The evaporated fuel treatment device 80 has a vapor passage 81 and a return passage 91 .

[0046] The vapor passage 81 is a passage that guides evaporated fuel generated in the fuel tank 40 to the canister 52. In this embodiment, a cooling device 57 is disposed in the vapor passage 81. Here, the cooling device 57 is also used as the cooling device disposed in the first atmosphere vent passage 55a. However, this is not limited to a case where the cooling device 57 is also used as the cooling device, and the cooling device may be a different cooling device from the cooling device disposed in the first atmosphere vent passage 55a. In this way, by disposing the cooling device 57 midway in the vapor passage 81, the evaporated fuel that flows into the canister 52 through the vapor passage 81 is cooled and liquefied by the cooling device 57.

[0047] The return passage 91 is a passage for returning the liquefied fuel obtained by cooling the evaporated fuel that flows into the canister 52 through the vapor passage 81 to the fuel tank 40. The return passage 91 is formed by piping that connects the cooling device 57 and the fuel tank 40. The return passage 91 is designed so that the fuel liquefied by the cooling device 57 returns to the fuel tank 40 by its own weight.

[0048] In the evaporated fuel treatment device 80 configured as described above, a portion of the evaporated fuel flowing into the canister 52 through the vapor passage 81 is cooled by the cooling device 57 and liquefied, and the liquefied fuel can be returned to the fuel tank 40 through the return passage 91. Therefore, the evaporated fuel flowing into the canister 52 can be reduced, and the frequency with which the amount of evaporated fuel exceeds the adsorption capacity of the activated carbon of the canister 52 and is released into the atmosphere can be reduced.

[0049] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and modifications and the like are possible within the scope of the present invention. In the above-described embodiment, the control unit 70 acquires the humidity information from the humidity sensor 60, but this is not the only possible case. The control unit 70 may acquire the humidity information from an external source via a communication means provided in the vehicle.

[0050] In the above-described embodiment, the evaporated fuel treatment device 50, 80 has been described as having the first shut-off valve 56a and the second shut-off valve 56b, but is not limited to this. For example, the evaporated fuel treatment device 50, 80 may be provided with one three-way valve at the position where the first atmosphere open passage 55a and the second atmosphere open passage 55b intersect.

[0051] In the above-described embodiment, the heat exchanger 59 brings a part of the exhaust passage 30 and a part of the first atmosphere open passage 55a into close proximity to each other. However, the present invention is not limited to this. The heat exchanger 59 may be a heating device such as a heater that is driven by power supplied from the battery 58. The heating device is driven under the control of the control unit 70. When a heating device is used in the heat exchange section 59, the control section 70 controls the heating device to be turned off in S12 of the flowchart in FIG. 2 described above, turned on in S16 and S17, and turned off in S18, thereby preventing a drop in the temperature of the activated carbon and preventing excess power consumption at the same time. [Explanation of symbols]

[0052] 10: Engine 20: Intake passage 30: Exhaust passage 40: Fuel tank 50, 80: Evaporative fuel treatment device 51, 81: Vapor passage 52: Canister 55a: First atmosphere release passage 55b: Second atmosphere release passage 56a: First closing valve 56b: Second closing valve 57: Cooling device 58: Battery 59: Heat exchanger 60: Humidity sensor 70: Control unit

Claims

1. a canister that temporarily absorbs evaporated fuel in the fuel tank; an atmosphere vent passage communicating with the canister; a cooling device disposed on the atmospheric open passage and driven by power supplied from a battery; an acquisition means for acquiring outdoor air humidity information; a control unit for controlling the cooling device, The control unit An evaporative fuel treatment device characterized by, when performing purge control to supply purge gas containing evaporated fuel purged from the canister to an internal combustion engine, if the humidity acquired by the acquisition means is above a threshold value, controlling the air flowing into the canister through the atmosphere open passage to be cooled by the cooling device.

2. When the atmosphere vent passage is a first atmosphere vent passage, a second atmosphere-opening passage communicating with the canister and not including a cooling device; a shutoff valve that shuts off either the first atmosphere release passage or the second atmosphere release passage so that air does not flow in; a heat exchanger that is disposed on the first atmosphere release passage and closer to the canister than the cooling device and that exchanges heat with an exhaust system, The control unit The evaporative fuel treatment device described in claim 1, characterized in that when purge control is being performed, if the humidity acquired by the acquisition means is above a threshold value, the shut-off valve is controlled so that air flows in from the first atmosphere open passage, and the air flowing into the canister through the first atmosphere open passage is controlled so that it is cooled by the cooling device.

3. The control unit The evaporative fuel treatment device described in claim 2, characterized in that when purge control is being performed, if the humidity acquired by the acquisition means is less than a threshold value, the shut-off valve is controlled so that air flows in from the first atmosphere open passage, and the cooling device is controlled so that no electricity is applied.

4. The control unit The evaporative fuel treatment device described in claim 2, characterized in that when purge control is being performed, if the humidity acquired by the acquisition means is less than a threshold value, the shut-off valve is controlled so that air flows in from the second atmosphere open passage, and the cooling device is controlled so that no electricity is applied.

5. The control unit 5. The fuel vapor treatment device according to claim 2, wherein when purge control is not being performed, the closing valve is controlled so that the second atmosphere release passage communicates with the outside air.

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