JP2008255855A - Evaporated fuel treating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an evaporated fuel treating apparatus that realizes most appropriate purge of evaporated fuel in accordance with the state of adsorption of the evaporated fuel in a canister or a change thereof. <P>SOLUTION: The evaporated fuel treating apparatus 12 includes an ORVR canister member 26 and an evaporation canister member 36, and the evaporation canister member 36 is provided with a temperature sensor 56 for detection of internal temperature. On the basis of the temperature, or the change thereof, of an adsorbent 34 housed in the evaporation canister member 36 having been detected by the temperature sensor 56, the purge in the ORVR canister member 26 and the evaporation canister member 36 can be controlled, for example, preferential purge is conducted in the evaporation canister member 36 when the amount of evaporated fuel adsorbed in the evaporation canister member 36 is large. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel vapor processing apparatus.

  In an evaporative fuel processing apparatus for processing evaporative fuel generated in a fuel tank or the like, evaporative fuel generated at the time of refueling and evaporation generated at the time of non-fuel supply such as operation (hereinafter, collectively referred to as “during operation” as appropriate) It is preferable to properly treat both fuels. For example, Patent Document 1 describes a configuration in which an oil supply canister that operates in oil supply is provided in parallel with an operation canister that operates in operation. Furthermore, in this configuration, the solenoid valve between each canister and the engine (surge tank) is controlled so that the release of fuel vapor is less in the fuel canister than in the operation canister. A configuration for reducing the influence on engine control is described.

  By the way, when evaporating fuel is actually processed, it is desired to purge (desorb) the evaporative fuel in accordance with the adsorbed state of the evaporative fuel in the canister and its change.

JP-A-63-143374

  In view of the above facts, an object of the present invention is to provide an evaporative fuel processing apparatus capable of purging evaporative fuel optimally in accordance with the adsorbed state of the evaporative fuel in the canister and its change.

  According to the first aspect of the present invention, the canister unit for refueling that adsorbs the evaporated fuel generated in the fuel tank when refueling the fuel tank is disposed in parallel with the canister unit for refueling, and at least during vehicle operation. An operating canister that adsorbs the evaporated fuel generated in the fuel tank when the fuel tank is not refueled, and a temperature sensor that is provided in the operating canister and detects the temperature inside the operating canister And a purge switching means capable of switching between the purge of the oil supply canister and the purge of the operation canister based on the detection result by the temperature sensor.

  Therefore, in this fuel vapor processing apparatus, fuel vapor generated when fuel is supplied to the fuel tank is adsorbed by the canister for fuel supply, and fuel vapor generated when fuel is not supplied is adsorbed by the canister for operation.

  The temperature inside the canister unit for operation is detected by a temperature sensor, and the purge switching means switches between purging the canister unit for refueling and purging for the canister unit for operation based on the detection result. For example, when the temperature of the canister unit for operation is rising, it can be determined that the evaporated fuel is adsorbed to the canister unit for operation. On the other hand, when the temperature of the canister unit for operation is lowered, it can be determined that the evaporated fuel is desorbed from the canister unit for operation. Based on the adsorption state of the operation canister unit determined in this way, the fuel vapor can be optimally purged by switching to either the fuel supply canister unit or the operation canister unit.

  According to a second aspect of the present invention, in the first aspect of the present invention, there is provided an atmosphere communication pipe provided in the operation canister part and used for introducing the atmosphere during purge, and provided in the operation canister part. An evaporative fuel introduction pipe for introducing evaporative fuel from the fuel tank, and the temperature sensor is disposed at a position relatively close to the atmospheric communication pipe in the operation canister portion It includes a temperature sensor, and a fuel tank side temperature sensor disposed at a position relatively close to the evaporated fuel introduction pipe in the operation canister.

  That is, at least two temperature sensors are provided in the driving canister. Moreover, the temperature sensor includes an atmospheric temperature sensor at a position near the atmospheric communication pipe and a fuel tank temperature sensor at a position near the evaporated fuel introduction pipe. Therefore, as compared with a configuration that does not include such a plurality of temperature sensors, it is possible to more accurately determine the evaporated fuel adsorption state and purge state in the operating canister unit.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the purge apparatus includes an introduction air amount sensor capable of measuring the amount of air introduced into the operation canister unit, and the purge The switching means is characterized in that the purge frequency of the canister unit for operation can be changed based on the measurement results of the temperature sensor and the introduced air quantity sensor.

  Therefore, purging can be performed more optimally by changing the purge frequency of the canister for operation based on the temperature of the canister for operation and the amount of air introduced into the canister for operation Become. For example, when the time during which the temperature drop of the operating canister is stable is long with respect to the integrated value of the introduced air volume, the evaporated fuel that is adsorbed by the operating canister and not desorbed (so-called heel) Therefore, it is possible to increase the purge frequency of the operating canister unit.

  Since the present invention has the above-described configuration, it is possible to optimally purge the evaporated fuel in accordance with the adsorption state of the evaporated fuel in the canister and the change thereof.

  FIG. 1 shows a fuel vapor processing apparatus 12 according to a first embodiment of the present invention. The fuel vapor processing apparatus 12 has two housings, a first housing 14 and a second housing 16.

  Inside the first housing 14, filter membranes 18A and 18B made of a nonwoven fabric or the like are provided in parallel to the one end wall 14A and the other end wall 14B. The second housing 16 is also provided with filter membranes 20A and 20B made of a nonwoven fabric or the like in parallel with the one end wall 16A and the other end wall 16B.

  A partition wall 22 is provided in the first housing 14, and one space (space closer to the second housing 16) defined by the partition wall 22 and the two filter films 18A and 18B is, for example, An adsorbent 24 made of granular activated carbon is filled into an ORVR canister section 26. The other partitioned space (the space farther from the second housing 16) is filled with, for example, an adsorbent 28 formed by kneading activated carbon with a binder, thereby forming the blow-off prevention unit 30.

  Here, the adsorbent 24 is set so as to have a higher ability to adsorb evaporated fuel as compared to the adsorbent 28. Further, the adsorbent 28 is set to have a higher ability to release the adsorbed evaporated fuel than the adsorbent 24. Further, the adsorbent 28 is set to have a smaller resistance (airflow resistance) when the gas passes than the adsorbent 24.

  In addition, between the other end wall 14 </ b> B and the filter film 18 </ b> B is a communication portion 32 that communicates the ORVR canister portion 26 and the blow-through prevention portion 30.

  The second housing 16 is filled with an adsorbent 34 made of, for example, granular activated carbon that is substantially the same as the ORVR canister portion 26 to form an evaporation canister portion 36.

  The one end wall 14A of the first housing 14 and the one end wall 16A of the second housing 16 are connected to a fuel tank (not shown) at positions corresponding to the ORVR canister portion 26 and the evaporation canister portion 36, respectively. 48 is branched, and branch pipes 42A and 42B are connected to each other. A vapor switching valve 50 is provided at a branch portion of the evaporated fuel introduction pipe 48. As shown in FIG. 2, the vapor switching valve 50 is duty-controlled by the control device 52 so as to selectively send the evaporated fuel generated in the fuel tank to one of the ORVR canister unit 26 and the evaporation canister unit 36. It has become.

  An atmospheric communication pipe 54 is branched to the one end wall 14A of the first housing 14 (a position corresponding to the blow-off preventing portion 30) and the other end wall 16B of the second housing 16, and branch pipes 54A and 54B are connected to each other. And open to the atmosphere. An air introduction switching valve 64 is provided at a branch portion of the air communication pipe 54. As shown in FIG. 2, the air introduction switching valve 64 is duty-controlled by the control device 52, and either the air in the first housing 14 (the blow-through prevention unit 30 and the ORVR canister unit 26) or the evaporation canister unit 36 is discharged. To be sent selectively.

  Purge discharge pipes 42A and 42B are connected to one end wall 14A of the first housing 14 (a position corresponding to the ORVR canister portion 26) and the other end wall 16A of the second housing 16, respectively. The purge discharge pipes 42A and 42B are joined together to form one purge discharge pipe 42, which leads to an engine air supply system (not shown).

  A purge switching valve 62 is provided at the junction of the purge discharge pipes 42A and 42B. As shown in FIG. 2, the purge switching valve 62 is duty-controlled by the control device 52 and sends evaporated fuel from one of the ORVR canister unit 26 and the evaporation canister unit 36 to the engine (not shown) via the purge discharge pipe 42. It is like that.

  As shown in FIG. 1, the evaporation canister unit 36 is provided with a temperature sensor 56 capable of detecting the temperature of the internal adsorbent 34. The temperature data detected by the temperature sensor 56 is sent to the control device 52 as shown in FIG.

  Further, a fuel tank (not shown) is also provided with a fuel remaining amount sensor 58 (see FIG. 2) for detecting the fuel remaining amount in the fuel tank. Fuel remaining amount data from the fuel remaining amount sensor 58 is also sent to the control device 52.

  Next, the operation of this embodiment will be described.

  When fuel is supplied to the fuel tank, the vapor switching valve 50 is controlled by the control device 52 so as to send the evaporated fuel to the ORVR canister unit 26 but not to the evaporation canister unit 36. The evaporated fuel is adsorbed by the adsorbent 24 of the ORVR canister unit 26, but the evaporated fuel also flows to the blow-off prevention unit 30 via the communication unit 32, so that the evaporated fuel is also adsorbed by the adsorber 28.

  In contrast, during operation, the vapor switching valve 50 is controlled by the control device 52 so as to send the evaporated fuel to the evaporation canister unit 36 but not to the ORVR canister unit 26. The evaporated fuel is adsorbed by the adsorbent 34 of the evaporation canister unit 36.

  Further, the evaporated fuel adsorbed by the ORVR canister unit 26 and the evaporation canister unit 36 is purged by the air flowing in through the atmosphere communication pipe 54. At this time, in this embodiment, purging in the ORVR canister unit 26 and the evaporation canister unit 36 can be controlled based on the temperature of the adsorbent 34 in the evaporation canister unit 36 detected by the temperature sensor 56 or a temperature change. . FIG. 3 shows a flowchart of this control as an example.

  This flow is executed as the engine is started, and is terminated at an arbitrary step when the engine is stopped. First, in step S112, based on the data sent from the fuel remaining amount sensor 58, it is determined whether or not the fuel remaining amount in the fuel tank has increased. If it is determined that the remaining amount of fuel in the fuel tank has increased, it is considered that fuel has been supplied into the fuel tank, and the process proceeds to step S114. In step S114, the ORVR canister section 26 is purged. Specifically, the atmosphere introduction switching valve 64 and the purge switching valve 62 are switched to the ORVR canister unit 26 side.

  If it is determined in step S112 that the remaining amount of fuel in the fuel tank has not increased, the process proceeds to step S116 to purge the evaporation canister unit 36. Specifically, the atmosphere introduction switching valve 64 and the purge switching valve 62 are switched to the evaporation canister unit 36 side. At this time, the evaporated fuel from the fuel tank is sent to the ORVR canister unit 26 and is adsorbed by the adsorbent 24.

  Next, in step S118, it is determined whether or not the temperature of the evaporation canister unit 36 has stabilized. That is, when the temperature of the evaporation canister unit 36 is not stable, the process returns to step S116 and the evaporation canister unit 36 is continuously purged. When the temperature of the evaporation canister unit 36 is stable, the purge is completed. Therefore, the process proceeds to step S114 and the ORVR canister unit 26 is purged (the air introduction switching valve 64 and the purge switching valve 62 are switched to the ORVR canister unit 26 side).

  Here, there is a high possibility that the evaporated fuel is sent to the evaporation canister unit 36 while the engine is being driven. Therefore, in the next step S120, it is determined whether or not the temperature of the evaporation canister 36 has increased. That is, when the temperature of the evaporation canister unit 36 is not increased, it can be determined that the amount of evaporated fuel adsorbed to the adsorbent 34 of the evaporation canister unit 36 is small, so the process returns to step S114 and continues to the ORVR canister unit 26. Purge. However, at this stage, the purge of the ORVR canister 26 may already be sufficiently performed in preparation for the next refueling.

  When the temperature of the evaporation canister unit 36 is rising, it can be determined that the amount of evaporated fuel adsorbed on the adsorbent 34 of the evaporation canister unit 36 has increased, so the routine proceeds to step S122, where the evaporation canister unit 36 is set. Purge. Thereby, it is possible to prevent excessive evaporated fuel from flowing into the evaporation canister unit 36. At this time, since the temperature of the evaporation canister 36 is raised by the heat of adsorption of the evaporated fuel, more efficient purging is possible by using this heat.

  In step S124, it is determined whether or not the temperature of the evaporation canister unit 36 is stable. When the temperature of the evaporation canister unit 36 is not stable, the process returns to step S122 and the evaporation canister unit 36 is continuously purged. When the temperature of the evaporation canister unit 36 is stable, the purge is considered to be completed. Then, the process returns to step S112.

  As described above, in the evaporated fuel processing apparatus 12 according to the present embodiment, the temperature is detected by the temperature sensor 56 provided in the evaporation canister unit 36, so that the evaporated fuel is adsorbed / desorbed to the evaporation canister unit 36 and the state thereof. The change is judged, and furthermore, based on this judgment, it is possible to optimally purge the evaporation canister unit 36 and the ORVR canister unit 26.

  The above “temperature stability” includes, of course, the case where the temperature shows a constant value regardless of the passage of time. This includes the case where the correlation with the degree of purge of the evaporation canister 36 is considered to be low even if the temperature changes in the state. On the contrary, the “temperature increase” increases the temperature regardless of the change in the outside air temperature (or with a low relationship), and this has a high correlation with the adsorption of the evaporated fuel in the evaporator canister 36. Includes possible cases.

  FIG. 4 shows an evaporated fuel processing device 72 according to the second embodiment of the present invention. In the second embodiment, the same components and members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the evaporated fuel processing apparatus 72 of the second embodiment, the evaporation canister unit 36 includes two temperature sensors instead of the temperature sensor 56 according to the first embodiment. One temperature sensor is an atmosphere-side temperature sensor 74 disposed at a position near the other end wall 16B of the second housing 16, and the other temperature sensor is a fuel tank side temperature disposed at a position near the one end wall 16A. The sensor 76 is used. Each of these temperature sensors according to the second embodiment can detect the temperature of the adsorbent 34 locally within the evaporation canister 36, as with the temperature sensor 56 of the first embodiment. Actually, the evaporative fuel is adsorbed in the evaporator canister 36. Since desorption (purge) occurs from the one end wall 16A side and occurs from the other end wall 16B side, the temperature or temperature change of the adsorbent 34 in the evaporator canister 36 both at the time of adsorption and at the time of desorption. There is a difference. Therefore, the number and position of the temperature sensors are not particularly limited as long as this difference can be detected. However, in the present embodiment, the temperature sensors are arranged in the vicinity of the one end wall 16A and the other end wall 16B in order to perform efficient and accurate detection. ing.

  Then, as shown in FIG. 5, the temperature data detected by these two temperature sensors are all sent to the control device 52. Hereinafter, for convenience, the temperature detected by the atmosphere side temperature sensor 74 is referred to as “atmosphere side temperature”, and the temperature detected by the fuel tank side temperature sensor 76 is referred to as “fuel tank side temperature”.

  The evaporated fuel processing device 72 of the second embodiment has the same configuration as the evaporated fuel processing device 12 of the first embodiment except for the above. As in the first embodiment, when refueling the fuel tank, the vapor switching valve 50 is controlled by the control device 52 so as to send the evaporated fuel to the ORVR canister unit 26 but not to the evaporation canister unit 36. Then, the evaporated fuel flows to the ORVR canister unit 26 and the blow-through preventing unit 30. Further, during operation, the vapor switching valve 50 is controlled by the control device 52 so as to send the evaporated fuel to the evaporation canister unit 36 but not to the ORVR canister unit 26, and the evaporated fuel is sent to the evaporation canister unit 36. .

  Similarly to the first embodiment, the evaporated fuel adsorbed by the ORVR canister unit 26 and the evaporation canister unit 36 is purged by the air flowing in through the atmospheric communication pipe 54. At this time, in the second embodiment, the purge in the ORVR canister unit 26 and the evaporation canister unit 36 can be controlled using the temperatures detected by the atmospheric temperature sensor 74 and the fuel tank temperature sensor 76. it can. FIG. 6 shows a flowchart of this control as an example.

  Also in this flow, as in the first embodiment, it is executed as the engine starts, and ends in an arbitrary step when the engine is stopped. First, in step S212, based on the data from the fuel remaining amount sensor 58, it is determined whether or not the remaining amount of fuel in the fuel tank has increased. If it is determined that the fuel has increased, fuel has been supplied to the fuel tank. In step S214, the ORVR canister unit 26 is purged.

  If it is determined in step S212 that the remaining amount of fuel in the fuel tank has not increased, the process moves to step S216 to purge the evaporation canister unit 36. At this time, the evaporated fuel from the fuel tank is sent to the ORVR canister unit 26 and is adsorbed by the adsorbent 24. Up to this point, the same control as in the first embodiment is performed.

  Next, in step S218, it is determined whether or not the fuel tank side temperature is approximately the same as the air side temperature. That is, when these temperatures are not the same level, it can be considered that the purge canister 36 has not been purged. Therefore, the process returns to step S216 to continuously purge the evaporator canister 36. On the other hand, when the fuel tank side temperature is about the same as the atmosphere side temperature, it is considered that the purge is completed, and the routine proceeds to step S214 where the ORVR canister unit 26 is purged.

  In the next step S220, it is determined whether or not the fuel tank side temperature has increased. If it has increased, it is further determined in step S222 whether or not the atmospheric temperature has increased. That is, when the fuel tank side temperature does not increase, or when the fuel tank side temperature does not increase but the atmospheric side temperature does not increase, it is determined that the amount of evaporated fuel adsorbed on the adsorbent 34 of the evaporation canister 36 is small. Therefore, the process returns to step S214, and the ORVR canister section 26 is continuously purged. At this stage, the purge of the ORVR canister 26 may already be sufficiently performed in preparation for the next refueling.

  On the other hand, when the temperature on the fuel tank side rises, it can be determined that the amount of evaporated fuel generated in the fuel tank and sent to the evaporation canister unit 36 has increased. After that, if it is determined that the atmospheric temperature has also increased, the process proceeds to step S224, where the evaporation canister 36 is purged. Thereby, it is possible to prevent excessive evaporated fuel from flowing into the evaporation canister unit 36. In addition, since the purge is performed in a state where the evaporated fuel is accumulated to some extent in the evaporation canister portion 36, an efficient purge can be performed. Further, at this stage, the temperature of the evaporation canister 36 is increased by the heat of adsorption of the evaporated fuel, so that more efficient purging can be performed by using this heat.

  If it is determined in step S220 that the fuel tank temperature has increased, it is subsequently determined in step S222 whether the atmospheric temperature has increased. For this reason, when it is once determined that the fuel tank temperature is rising, it is preferable to shorten the detection interval (time interval) of the fuel tank temperature so that a more accurate determination can be made.

  In step S226, it is determined whether or not the temperature on the fuel tank side is stable. If the temperature is not stable, the process returns to step S224 and the evaporation canister 36 is continuously purged. When this temperature is stable, it is considered that the purge is completed, and the process returns to step S212. The temperature used for the determination in step S226 may be the atmospheric temperature. However, considering that the purge in the evaporation canister 36 proceeds from the atmospheric side, it is better to determine the completion of the purge using the fuel tank temperature. More accurate judgment is possible.

  Thus, also in the evaporative fuel processing apparatus 72 of the second embodiment, the temperature is detected by the atmospheric temperature sensor 74 and the fuel tank temperature sensor 76 provided in the evaporation canister unit 36, so that Based on this determination, the evaporation canister 36 and the ORVR canister 26 can be optimally purged based on the determination of the adsorbed / desorbed state of the evaporated fuel and its change. In particular, compared to the first embodiment, using two temperature sensors, temperature deviation and change in the evaporation canister unit 36 can be used as a determination material, and more accurate purging becomes possible.

  FIG. 7 shows a fuel vapor processing apparatus 82 according to the third embodiment of the present invention. In the third embodiment, the configuration is substantially the same as that of the evaporated fuel processing device 72 of the second embodiment, but in addition to this, an air amount sensor 84 is provided in the atmosphere communication pipe 54, and the atmosphere communication pipe is provided. The amount of air (gas) flowing through 54 can be detected. This detection data is sent to the control device 52 as shown in FIG. The control device 52 integrates and estimates the air amount (introduced air amount) actually sent to the evaporation canister unit 36 from the air amount data sent from the air amount sensor 84 and the control status of the air introduction switching valve 64. can do. Hereinafter, this is referred to as “estimated purge air integrated amount”. Therefore, the introduction air amount sensor according to the present invention is constituted by the air amount sensor 84 and the control device 52.

  Further, in the evaporated fuel processing device 82 of the third embodiment, the temperature reduction amount (that is, the desorption amount) of the evaporation canister unit 36 with respect to the estimated purge air integrated amount is measured in the control device 52, and the temperature per unit time is measured. A circuit for storing the amount of decrease is provided. The control device 52 stores in advance a reference value for the amount of temperature decrease per unit time.

  Also in the evaporative fuel processing apparatus 82 of the third embodiment configured as described above, the evaporative fuel can be adsorbed and desorbed in the same manner as the evaporative fuel processing apparatus 72 of the second embodiment.

Furthermore, in the evaporated fuel processing device 82 of the third embodiment, the evaporated fuel (so-called heel) remaining without being purged in the evaporation canister 36 can be estimated, and the frequency of purge can be increased. That is, at any time point during engine driving, the temperature decrease amount per unit time with respect to the estimated purge air integrated amount is calculated, and this is compared with the reference value of the temperature decrease amount per unit time stored in advance. Then, when the time period during which the temperature decrease amount per unit time is stable is long with respect to the estimated purge air integrated amount (in short, the temperature decreases despite a predetermined amount of air (purge air) being sent to the evaporator canister 36 for a predetermined time). When the amount is less than the reference value), it can be considered that the heel of the evaporation canister unit 36 has increased, and therefore the frequency of purge of the evaporation canister unit 36 is increased.

  Thus, in the evaporative fuel processing device 82 of the third embodiment, it is possible to perform the purge more accurately by estimating the heel amount of the evaporation canister unit 36 and increasing the purge frequency based on this estimation. .

  In the third embodiment, the air quantity sensor 84 is provided in the branch pipe 54B of the atmosphere introduction pipe 54, so that the amount of air introduced into the evaporation canister 36 is controlled regardless of the switching state of the atmosphere introduction switching valve 64. It may be possible to detect and integrate.

  In the above description, the evaporative fuel processing apparatus of the third embodiment is the same as the evaporative fuel processing apparatus 72 of the second embodiment, and the air amount sensor 84 and the like are provided. The evaporative fuel processing apparatus 12 may be provided with an air amount sensor 84 or the like to be the evaporative fuel processing apparatus of the third embodiment.

  Moreover, in each said embodiment, although the evaporative fuel processing apparatus gave the example divided | segmented into the 1st housing 14 and the 2nd housing 16, these housings may be integrated. In addition, the present invention can be applied to a configuration in which the first housing 14 is not provided with the blow-off preventing unit 30.

It is sectional drawing which shows schematic structure of the evaporative fuel processing apparatus of 1st embodiment of this invention. It is a block diagram which shows the control system which comprises the evaporative fuel processing apparatus of 1st embodiment of this invention. It is a flowchart which shows an example of the purge process in the evaporative fuel processing apparatus of 1st embodiment of this invention. It is sectional drawing which shows schematic structure of the evaporative fuel processing apparatus of 2nd embodiment of this invention. It is a block diagram which shows the control system which comprises the evaporative fuel processing apparatus of 2nd embodiment of this invention. It is a flowchart which shows an example of the purge process in the evaporative fuel processing apparatus of 2nd embodiment of this invention. It is sectional drawing which shows schematic structure of the evaporative fuel processing apparatus of 3rd embodiment of this invention. It is a block diagram which shows the control system which comprises the evaporative fuel processing apparatus of 3rd embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Evaporative fuel processing apparatus 14 1st housing 16 2nd housing 18A, 18B Filter membrane 20A, 20B Filter membrane 22 Partition 24 Adsorbent body 26 ORVR canister part 28 Adsorbent body 30 Blow-out prevention part 32 Communication part 34 Adsorbent body 36 Evaporative canister part 42 Purge discharge piping 48 Evaporative fuel introduction piping 50 Vapor switching valve (purge switching means)
52 Control device (purge switching means)
54 Atmospheric communication pipe 56 Temperature sensor 58 Fuel level sensor 62 Purge switching valve (purge switching means)
64 Air introduction switching valve (purge switching means)
72 Evaporated fuel processing device 74 Atmospheric side temperature sensor 76 Fuel tank side temperature sensor 82 Evaporated fuel processing device 84 Air amount sensor

Claims (3)

A fuel canister for adsorbing evaporated fuel generated in the fuel tank when refueling the fuel tank;
An in-canister unit for operation that is arranged in parallel with the canister unit for refueling, and at which evaporative fuel generated in the fuel tank at the time of non-refueling to a fuel tank including at least during vehicle operation is adsorbed;
A temperature sensor that is provided in the canister unit for operation and detects the temperature inside the canister unit for operation;
A purge switching means capable of switching between the purge of the fueling canister unit and the purge of the operating canister unit based on a detection result by the temperature sensor;
The evaporative fuel processing apparatus characterized by having. An atmospheric communication pipe provided in the canister unit for operation and used for air introduction during purge;
An evaporative fuel introduction pipe provided in the canister for operation and used for introducing evaporative fuel from a fuel tank;
Have
The temperature sensor is
An atmospheric temperature sensor disposed at a position relatively close to the atmospheric communication pipe in the operation canister,
A fuel tank side temperature sensor disposed at a position relatively close to the evaporated fuel introduction pipe in the operation canister part;
The evaporative fuel processing apparatus of Claim 1 characterized by the above-mentioned. An introduced air amount sensor capable of measuring the amount of air introduced into the canister for operation;
Have
3. The purge frequency of the canister unit for operation can be changed based on the measurement results of the temperature sensor and the introduced air quantity sensor. The evaporative fuel processing apparatus of description.

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