JP2016050540A - Evaporation fuel treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect a valve opening start position regardless of an operating state of an engine, by detecting characteristic change indicating that an evaporated fuel flows to a downstream side of a flow rate control valve, in detecting the valve opening start position where communication of a fuel tank and a canister is started, after start of a valve opening motion of the flow rate control valve, in the evaporated fuel treatment device in which the flow rate control valve having a dead band is used as a valve on a passage connecting the canister and the fuel tank.SOLUTION: An evaporated fuel treatment device includes valve opening start position detecting means for detecting a valve opening start position of a flow rate control valve by detecting that an evaporated fuel flows to a canister from the flow rate control valve after starting a valve opening motion of the flow rate control valve, and learning means for memorizing the valve opening start position detected by the valve opening start position detecting means as a learning value in controlling the valve opening of the flow rate control valve.SELECTED DRAWING: Figure 1

Description

  The present invention uses a flow control valve having a dead zone in which communication between the fuel tank and the canister is not performed until a predetermined amount of operation is performed after the valve opening operation is started as a valve on a path connecting the fuel tank and the canister. The present invention relates to an evaporative fuel processing apparatus.

  Patent Document 1 below discloses an evaporative fuel processing apparatus that uses a flow rate control valve having a dead zone as a valve on a path connecting a fuel tank and a canister. The flow rate control valve passes through the dead zone after starting the valve opening operation until reaching the valve opening start position where the fuel tank and the canister communicate with each other. Therefore, in order to quickly perform the valve opening control of the flow rate control valve, the valve opening start position is learned in advance, and the normal valve opening control is started from the valve opening start position. For such learning, it is necessary to detect the valve opening start position, and the detection is performed by detecting a decrease in the air-fuel ratio in the air-fuel mixture sucked into the engine.

JP2011-256778A

  However, the air-fuel ratio also changes depending on the operating condition of the engine, and it may be erroneously detected if the valve opening start position is detected due to the air-fuel ratio drop. For example, when the engine load suddenly changes, the air-fuel ratio may temporarily decrease.

  In view of such a problem, an object of the present invention is to use a flow control valve having a dead zone as a valve on a path connecting a canister and a fuel tank in an evaporative fuel processing apparatus. The engine operating status is detected by detecting the valve opening start position at which the fuel tank and the canister begin to communicate with each other, and detecting a characteristic change that indicates that evaporated fuel has flowed downstream of the flow control valve. Regardless of this, it is to accurately detect the valve opening start position.

<See Figure 1>
In the first aspect of the present invention, the evaporated fuel in the fuel tank is adsorbed by the canister, the adsorbed evaporated fuel is sucked into the engine, and the valve opening operation is started as a valve on the path connecting the fuel tank and the canister. Thereafter, in the evaporative fuel processing apparatus using the flow control valve having a dead zone in which the communication between the fuel tank and the canister is not performed until the predetermined amount of operation is performed, after the opening operation of the flow control valve is started, A valve opening start position detecting means for detecting that the evaporated fuel has flowed into the canister and detecting a valve opening start position of the flow control valve, and a valve opening start position detected by the valve opening start position detecting means Learning means for storing as a learning value when performing the valve opening control.

  According to a second aspect of the present invention, in the first aspect of the invention, the valve opening start position detecting means detects a canister evaporated fuel concentration detecting means for detecting the evaporated fuel concentration in the canister, and detects a concentration of the evaporated fuel sucked into the engine. It is either an intake evaporative fuel concentration detecting means or a canister temperature detecting means for detecting a temperature rise of the canister.

  In the second invention, the canister evaporative fuel concentration detecting means can be constituted by a concentration sensor for detecting the evaporative fuel concentration in the canister. The intake fuel vapor concentration detection means can be configured by taking in the fuel vapor concentration value used in the air-fuel ratio control program of the engine. Further, the canister temperature detecting means can be constituted by a temperature sensor that detects a temperature rise of the canister.

  According to a third aspect of the present invention, in the second aspect of the invention, the valve opening start position detecting means detects when the canister evaporated fuel concentration detecting means detects that the evaporated fuel concentration in the canister is equal to or higher than a predetermined concentration. When the intake fuel vapor concentration detection means detects that the concentration of the evaporated fuel sucked into the tank is greater than or equal to a predetermined concentration, the canister temperature detection means detects that the temperature rise of the canister is greater than or equal to a predetermined temperature. If it is, the valve opening position of the flow control valve is detected as the valve opening start position.

<See Figure 2>
According to a fourth aspect of the present invention, there is provided the internal pressure sensor according to the first aspect, wherein the internal pressure sensor detects a space pressure in the fuel tank as an internal pressure, and the valve opening start position detecting means detects the internal pressure after starting the valve opening operation of the flow control valve. When the internal pressure detected by the sensor has changed, and it has been detected that evaporative fuel has flowed from the flow control valve to the canister or the evaporative fuel has been drawn into the engine after the flow control valve has started to open. The valve opening position of the flow control valve is detected as the valve opening start position.

  In the fourth invention, the valve opening start position based on the internal pressure is detected when the second-order differential value of the internal pressure is a predetermined value or more, or when the internal pressure changes by a predetermined pressure or more compared to when the flow control valve is closed. Can do. Further, the detection of the valve opening start position based on the evaporated fuel is performed when the evaporated fuel concentration in the canister is equal to or higher than the predetermined concentration, and when the evaporated fuel concentration sucked into the engine is equal to or higher than the predetermined concentration, the temperature rise of the canister is predetermined. When the temperature is equal to or higher than the temperature, it can be either when the air-fuel ratio feedback correction amount of the engine changes by a predetermined amount or more.

  According to the first to third inventions, after the opening operation of the flow control valve is started, it is detected that the evaporated fuel has flowed to the canister through the flow control valve, and the valve opening start position of the flow control valve is detected. Therefore, the valve opening start position of the flow control valve can be accurately detected without being affected by the operating state of the engine as in the conventional case of detecting the valve opening start position of the flow control valve by the decrease in the air-fuel ratio. .

  According to the fourth aspect of the present invention, the valve opening start position of the flow control valve is detected based on the change in the internal pressure of the fuel tank, and further, the evaporated fuel has flown into the canister or the evaporated fuel has been drawn into the engine. Is detected, the valve opening position of the flow control valve is finally detected as the valve opening start position. Therefore, the valve opening start position of the flow control valve can be detected more accurately.

It is a claim corresponding figure corresponding to the said 1st invention. It is a claim corresponding figure corresponding to the said 4th invention. It is a system configuration figure of a 1st embodiment of the present invention. It is a flowchart of the valve opening start position learning control processing routine of the flow control valve in the first embodiment. It is a flowchart of the valve opening start position learning control processing routine of the flow control valve in 2nd Embodiment of this invention. It is a flowchart of the valve opening start position learning control processing routine of the flow control valve in 3rd Embodiment of this invention. It is a flowchart of the valve opening start position learning control processing routine of the flow control valve in 4th Embodiment of this invention. It is a flowchart of the valve opening start position learning control processing routine of the flow control valve in 5th Embodiment of this invention. It is a time chart which shows changes, such as a valve opening amount of a flow control valve during fuel control in each above-mentioned embodiment, and fuel tank internal pressure.

<First embodiment>
3 and 4 show a first embodiment of the present invention. In this embodiment, as shown in FIG. 3, an evaporated fuel processing device 20 is added to the engine system 10 of the vehicle.

  In FIG. 3, the engine system 10 is a well-known one, and supplies an air-fuel mixture obtained by mixing fuel to air via an intake passage 12 to an engine body 11. Air is supplied with its flow rate controlled by a throttle valve 14, and fuel is supplied with its flow rate controlled by a fuel injection valve (not shown). Both the throttle valve 14 and the fuel injection valve are connected to the control circuit 16, and the throttle valve 14 supplies a signal related to the valve opening amount of the throttle valve 14 to the control circuit 16, and the fuel injection valve is opened by the control circuit 16. Being controlled. Fuel is supplied to the fuel injection valve, and the fuel is supplied from the fuel tank 15.

  The evaporated fuel processing device 20 adsorbs fuel vapor generated during refueling or fuel vapor evaporated in the fuel tank 15 (hereinafter referred to as evaporated fuel) to the canister 21 via the vapor passage 22. The evaporated fuel adsorbed by the canister 21 is supplied to the intake passage 12 on the downstream side of the throttle valve 14 via the purge passage 23. The vapor passage 22 is provided with a step motor type blocking valve (corresponding to a flow control valve in the present invention, hereinafter simply referred to as a blocking valve) 24 so as to open and close the passage 22. A purge valve 25 is provided to open and close the passage 23. The blocking valve 24 has a dead zone where the fuel tank 15 and the canister 21 are not communicated until the valve element reaches a predetermined opening after the opening operation by the step motor is started. When the valve body reaches a predetermined opening, the fuel tank 15 and the canister 21 communicate with each other. The position of the valve body that has reached the predetermined opening corresponds to the valve opening start position in the present invention.

  Activated carbon 21 a as an adsorbent is loaded in the canister 21, and the evaporated fuel from the vapor passage 22 is adsorbed by the activated carbon 21 a, and the adsorbed evaporated fuel is discharged to the purge passage 23. The canister 21 is provided with a concentration sensor 27 and a temperature sensor 29. The concentration sensor 27 detects the concentration of the evaporated fuel adsorbed on the canister 21 (hereinafter also referred to as vapor concentration), and the temperature sensor 29 detects the temperature of the activated carbon 21 a in the canister 21. An atmospheric passage 28 is also connected to the canister 21, and when an intake negative pressure is applied to the canister 21 via the purge passage 23, atmospheric pressure is supplied through the atmospheric passage 28 and evaporation through the purge passage 23. The fuel is purged. The air passage 28 sucks air from the vicinity of the fuel filler port 17 provided in the fuel tank 15.

  Various signals necessary for controlling the valve opening time of the fuel injection valve and the like are input to the control circuit 16. In addition to the valve opening amount signal of the throttle valve 14 described above, the detection signal of the pressure sensor 26 for detecting the internal pressure of the fuel tank 15 and the detection signals of the concentration sensor 27 and the temperature sensor 29 are shown in FIG. Is input to the control circuit 16. In addition to the control of the fuel injector opening time as described above, the control circuit 16 controls the closing valve 24 and the purge valve 25 in the case shown in FIG.

  Next, the learning control processing routine for the valve opening start position of the step motor type blockade valve 24 performed by the control circuit 16 will be described based on the flowchart of FIG. 4 with reference to the time chart of FIG. When the processing of this routine is executed, it is determined in step S1 whether or not a learning execution flag is set. The learning execution flag is set when the learning routine is in a state suitable for executing the learning control of the valve opening start position of the stepping motor type blocking valve 24 by a processing routine (not shown). For example, an ignition switch (not shown) that is a power switch of the vehicle is turned on and the vehicle is set in a stopped state. When the learning execution flag is set, an affirmative determination is made in step S1, and learning control is executed in the processing after step S2.

  In step S2, the blocking valve 24 is opened stepwise by a predetermined opening amount by a step motor as shown in FIG. During this time, in step S11, it is determined whether or not the time measurement counter has reached a set value. When the preset time elapses and the counter reaches the set value and the determination in step S11 is affirmative, in step S12, the vapor concentration adsorbed on the canister 21 at that time is measured and taken in by the concentration sensor 27. . In the next step S13, it is determined whether or not the vapor concentration taken in in step S12 is A% or more. The A% of the vapor concentration is detected in the canister 21 when the closed valve 24 reaches the valve opening start position, the fuel tank 15 and the canister 21 are communicated, and the evaporated fuel starts to flow from the fuel tank 15 to the canister 21. Vapor concentration is set. A% of the vapor concentration corresponds to the predetermined concentration of the present invention.

  Until the vapor concentration reaches A%, a negative determination is made in step S13, and the processes after step S2 are repeated. Meanwhile, the valve opening amount of the blocking valve 24 is gradually increased stepwise as shown in FIG. When the vapor concentration reaches A% and step S13 is affirmatively determined, in step S21, the valve opening position of the blocking valve 24 at that time is stored as the valve opening start position. When the learning of the valve opening start position is completed in this manner, the blocking valve 24 stands by at the valve opening position immediately before the valve opening start position in preparation for normal valve opening control (pressure release control). The vapor concentration time chart and the valve opening time chart of the block valve 24 shown in FIG. When the learning control of the valve opening start position of the blocking valve 24 is completed in this way, the learning control processing routine described above is executed until the learning completion flag is set and then the learning execution flag is set in step S22. Not executed.

  As described above, the learning control of the valve opening start position of the block valve 24 is performed, and when the valve opening control is performed thereafter, the valve 24 is immediately opened from the valve opening start position stored as the learned value. The valve can be started. Further, when learning the valve opening start position, after the opening operation of the blocking valve 24 is started, it is detected from the vapor concentration of the canister 21 that the evaporated fuel has flowed to the canister 21 through the blocking valve 24, and the opening of the blocking valve 24 is performed. The valve start position is detected. Therefore, the valve opening start position of the block valve 24 can be accurately detected without being affected by the operating state of the engine as in the conventional case where the valve opening start position of the block valve 24 is detected by a decrease in the air-fuel ratio. .

<Second Embodiment>
FIG. 5 shows a second embodiment of the present invention. The feature of the second embodiment over the first embodiment is that, in the first embodiment, the fact that the evaporated fuel has flowed into the canister 21 is detected by the increase in the vapor concentration in the canister 21, whereas In the second embodiment, the fact that the evaporated fuel has flowed into the canister 21 is detected by the temperature rise of the canister 21. Specifically, instead of steps S11 to S13 in FIG. 4, steps S31 to S33 are executed in FIG. Other configurations are exactly the same, and the repetitive description of the same parts is omitted.

  In step S31, it is determined whether or not the time measurement counter has reached a set value. When the preset time elapses and the counter reaches the set value and the determination in step S31 is affirmative, in step S32, the temperature of the canister 21 measured by the temperature sensor 29 at that time is taken. In the next step S33, it is determined whether or not the temperature taken in in step S32 is B ° C. or higher. The temperature B ° C. of the canister 21 increases as the closed valve 24 reaches the valve opening start position so that the fuel tank 15 and the canister 21 communicate with each other, and evaporated fuel flows from the fuel tank 15 to the canister 21 and is adsorbed. The temperature in the canister 21 that is reached is set. The temperature B ° C. of the canister 21 corresponds to the predetermined temperature of the present invention.

  Until the temperature of the canister 21 reaches B ° C., a negative determination is made in step S33, and the processes after step S2 are repeated. Meanwhile, the valve opening amount of the blocking valve 24 is gradually increased stepwise as shown in FIG. When the temperature of the canister 21 reaches B ° C. and an affirmative determination is made in step S33, the opening position of the blocking valve 24 at that time is stored as the valve opening start position in steps S21 and S22, and the learning completion flag is set. The The time chart of the activated carbon temperature of the canister 21 and the time chart of the valve opening amount of the blocking valve 24 in FIG.

  As described above, when learning control of the opening start position of the blocking valve 24 is performed, the temperature of the canister 21 is detected based on the temperature of the canister 21 after the opening operation of the blocking valve 24 starts and the flow of evaporated fuel to the canister 21 through the blocking valve 24. The valve opening start position of the blocking valve 24 is detected. Therefore, the valve opening start position of the block valve 24 can be accurately detected without being affected by the operating state of the engine as in the conventional case where the valve opening start position of the block valve 24 is detected by a decrease in the air-fuel ratio. .

<Third embodiment>
FIG. 6 shows a third embodiment of the present invention. A feature of the third embodiment over the first embodiment is that in the first embodiment, the fact that the evaporated fuel has flowed into the canister 21 is detected by an increase in the vapor concentration in the canister 21 and the block valve 24 While the valve opening start position is detected, in the third embodiment, in addition to this, a change in the internal pressure of the fuel tank 15 that occurs when the closing valve 24 is opened is detected, and both of them open the closing valve 24. When the start is detected, the blocking valve 24 is in the valve opening start position. Specifically, steps S1, S2, S21, and S22 of FIG. 4 are the same in FIG. 6, and the same reference numerals are given to the portions. On the other hand, instead of steps S11 to S13 in FIG. 4, steps S41 to S44, steps S51 to S55, and steps S61 and S62 are executed in FIG.

  In FIG. 6, when an affirmative determination is made in step S1, the process proceeds to step S41, and the fuel tank internal pressure (hereinafter also simply referred to as tank pressure) P1 at that time is measured and taken in by the pressure sensor 26. In the next step S42, it is determined whether or not the time measurement counter has reached a set value. When the preset time has elapsed, the counter reaches the set value, and the determination in step S42 is affirmative, the fuel tank internal pressure P2 at that time is measured and taken in by the pressure sensor 26 in step S43 as in step S41. . Next, in step S44, the differential pressure Vp1 between the fuel tank internal pressures P1 and P2 taken in as described above is calculated. As is apparent from FIG. 9, the differential pressure Vp1 obtained here corresponds to the amount of change per unit time of the tank pressure detected by the pressure sensor 26 in a state where the blocking valve 24 is closed.

  In the next step S2, the blocking valve 24 is opened stepwise as in the case of FIG. In subsequent steps S51 to S54, the tank pressures Pn and Pn + 1 detected by the pressure sensor 26 after the closing valve 24 starts the valve opening operation are measured and taken in, as in the above-described steps S41 to S44. It is obtained as the amount of change per unit time of tank pressure.

  In step S55, it is determined whether or not the change width between the differential pressure Vp1 obtained in step S44 and the differential pressure Vp obtained in step S54 is greater than or equal to a predetermined value. The predetermined value corresponds to the fact that the fuel tank internal pressure decreases as the closed valve 24 reaches the valve opening start position, the fuel tank 15 and the canister 21 are communicated, and the evaporated fuel starts to flow from the fuel tank 15 to the canister 21. The pressure change range is set. As shown in FIG. 9, at the timing when the tank internal pressure is Pn, Pn + 1, the change width of the differential pressure Vp with respect to the differential pressure Vp1 is substantially zero and does not exceed a predetermined value. Is repeated. When the tank internal pressure is Pn + 2, the change width of the differential pressure Vp with respect to the differential pressure Vp1 is equal to or greater than a predetermined value (the second-order differential value of the tank pressure is equal to or greater than the predetermined value). Proceed to

  In step S61, as in step S11 of FIG. 4, the vapor concentration adsorbed on the canister 21 at that time is measured and taken in by the concentration sensor 27. In step S62, as in step S13 of FIG. 4, it is determined whether the vapor concentration is A% or higher. Until the vapor concentration reaches A%, a negative determination is made in step S62, the processing from step S2 onward is repeated, and the valve opening amount of the blocking valve 24 is gradually increased stepwise. When the vapor concentration reaches A% and step S62 is affirmed, in step S21 and S22, the valve opening position of the blocking valve 24 at that time is stored as the valve opening start position, and the learning completion flag is set.

  In the case of the third embodiment, in step S55, the change width of the differential pressure Vp with respect to the differential pressure Vp1 is equal to or greater than a predetermined value (the second-order differential value of the tank pressure is equal to or greater than a predetermined value). It is determined that 24 has reached the valve opening start position. However, in step S62, it is determined that the blocking valve 24 has reached the valve opening start position for the first time in a state where the vapor concentration is A% or more and step S62 is affirmatively determined. That is, the valve opening start position is detected more reliably by determining the valve opening start position of the blocking valve 24 only when the two determination conditions are satisfied simultaneously.

<Fourth embodiment>
FIG. 7 shows a fourth embodiment of the present invention. The feature of the fourth embodiment over the third embodiment is that in the third embodiment, the fact that the evaporated fuel has flowed into the canister 21 is detected by the increase in the vapor concentration in the canister 21 and the block valve 24 Whereas the valve opening start position is detected, in the fourth embodiment, the fact that the evaporated fuel has flowed into the canister 21 is detected by the temperature rise of the canister 21 to detect the valve opening start position of the block valve 24. Is a point. Specifically, steps S71 and S72 are executed in FIG. 7 instead of steps S61 and S62 in FIG. Other configurations are exactly the same, and the repetitive description of the same parts is omitted.

  In step S71, the temperature of the canister 21 measured by the temperature sensor 29 at that time is taken. In step S72, it is determined whether or not the temperature taken in in step S71 is equal to or higher than B ° C. Until the temperature of the canister 21 reaches B ° C, a negative determination is made in step S72. However, when the temperature of the canister 21 reaches B ° C and a positive determination is made in step S72, the blocking at that time is performed in steps S21 and S22. The valve opening position of the valve 24 is stored as the valve opening start position, and the learning completion flag is set.

  In the case of the fourth embodiment, the basic content is the same as the third embodiment except that the vapor concentration is replaced by the temperature of the canister 21, and the two determination conditions are the same as described in the third embodiment. Only when they are satisfied at the same time, the valve opening start position of the blocking valve 24 is determined, thereby detecting the valve opening start position more reliably.

<Fifth embodiment>
FIG. 8 shows a fifth embodiment of the present invention. A feature of the fifth embodiment over the third embodiment is that in the third embodiment, the fact that the evaporated fuel has flowed into the canister 21 is detected by an increase in the vapor concentration in the canister 21 and the block valve 24 Whereas the valve opening start position is detected, in the fifth embodiment, the fact that the evaporated fuel has been sucked into the engine via the canister 21 is detected by the change in the air-fuel ratio feedback correction amount F / B of the engine and blocked. The valve opening start position of the valve 24 is detected. Specifically, instead of steps S61 and S62 in FIG. 6, steps S81 and S82 are executed in FIG. Other configurations are exactly the same, and the repetitive description of the same parts is omitted.

  In step S81, the air-fuel ratio feedback correction amount F / B in the air-fuel ratio control of the engine at that time is taken. In step S82, it is determined whether the air-fuel ratio feedback correction amount F / B fetched in step S81 is minus C% or less, or plus C% or more. While the engine is in steady operation, the air-fuel ratio feedback correction amount F / B is stable between minus C% and plus C%. In this state, a negative determination is made in step S82. On the other hand, when the blocking valve 24 reaches the valve opening start position and the evaporated fuel is sucked into the engine through the canister 21, the air-fuel ratio temporarily becomes rich, and the air-fuel ratio feedback correction amount F / B is minus C% or less. Therefore, an affirmative determination is made in step S82. C% of the air-fuel ratio feedback correction amount F / B corresponds to a predetermined amount of the air-fuel ratio feedback correction amount of the present invention. Thereafter, in steps S21 and S22, the opening position of the blocking valve 24 at that time is stored as the valve opening start position, and the learning completion flag is set. The change in the air-fuel ratio feedback correction amount F / B before and after the blockade valve 24 reaches the valve opening start position is shown in FIG.

  In the case of the fifth embodiment, the basic content is the same as in the third embodiment except that the vapor concentration is replaced by the air-fuel ratio feedback correction amount F / B. Only when two determination conditions are satisfied at the same time, the valve opening start position of the blocking valve 24 is determined, thereby detecting the valve opening start position more reliably.

  The processes of steps S11 to S13, steps S31 to S33, steps S41 to S44, steps S51 to S55, steps S61, S62, steps S71, S72, and steps S81, S82 in the above embodiments are the valve opening start in the present invention. It corresponds to position detecting means. Moreover, the process of step S21 is corresponded to the learning means in this invention.

  As mentioned above, although specific embodiment was described, this invention is not limited to those external appearances and structures, A various change, addition, and deletion are possible in the range which does not change the summary of this invention. For example, in the above-described embodiment, the flow control valve is the step motor type block valve 24, but a ball valve having a structure in which the valve opening amount is continuously changed by the rotation of the ball-shaped valve body may be used. Moreover, in the said embodiment, although this invention was applied to the engine system for vehicles, this invention is not limited to vehicles. In the case of an engine system for a vehicle, a hybrid vehicle using both an engine and a motor may be used.

10 Engine System 11 Engine Body (Engine)
DESCRIPTION OF SYMBOLS 12 Intake passage 14 Throttle valve 15 Fuel tank 16 Control circuit 17 Refueling port 20 Evaporative fuel processing device 21 Canister 21a Activated carbon 22 Vapor passage 23 Purge passage 24 Step motor type sealing valve (blocking valve, flow control valve)
25 Purge valve 26 Pressure sensor (Internal pressure sensor)
27 Concentration sensor 28 Air passage 29 Temperature sensor

Claims (4)

The fuel vapor in the fuel tank is adsorbed by the canister, the adsorbed fuel vapor is sucked into the engine, and as a valve on the path connecting the fuel tank and the canister, after the opening operation is started until a predetermined amount of operation is performed In an evaporative fuel processing apparatus using a flow control valve having a dead zone in which communication between the fuel tank and the canister is not performed,
A valve opening start position detecting means for detecting that the evaporated fuel has flowed from the flow control valve to the canister after starting the valve opening operation of the flow control valve, and detecting a valve opening start position of the flow control valve;
An evaporative fuel processing apparatus comprising: learning means for storing the valve opening start position detected by the valve opening start position detecting means as a learning value for performing valve opening control of the flow control valve. In claim 1,
The valve opening start position detecting means is
Canister evaporative fuel concentration detecting means for detecting evaporative fuel concentration in the canister;
Inhaled evaporated fuel concentration detecting means for detecting the evaporated fuel concentration sucked into the engine,
An evaporative fuel processing apparatus which is one of canister temperature detecting means for detecting a temperature rise of the canister. In claim 2,
The valve opening start position detecting means is
When the canister vaporized fuel concentration detecting means detects that the vaporized fuel concentration in the canister is equal to or higher than a predetermined concentration,
When the intake evaporated fuel concentration detection means detects that the concentration of evaporated fuel sucked into the engine is equal to or higher than a predetermined concentration,
An evaporative fuel processing apparatus that detects a valve opening position of a flow control valve as a valve opening start position when the canister temperature detection means detects that the temperature rise of the canister is equal to or higher than a predetermined temperature. In claim 1,
It has an internal pressure sensor that detects the space pressure in the fuel tank as the internal pressure,
The valve opening start position detecting means is
When the internal pressure detected by the internal pressure sensor changes after the start of the flow control valve opening operation, and after the start of the flow control valve open operation, evaporative fuel flows from the flow control valve to the canister, or to the engine. When it detects that evaporative fuel has been inhaled,
An evaporative fuel processing device that detects a valve opening position of a flow control valve as a valve opening start position.

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