JP5232079B2 - Evaporative fuel processing equipment - Google Patents

Description

  The present invention relates to a technical field of an evaporative fuel processing apparatus for processing evaporative fuel.

  As an evaporative fuel processing apparatus for processing evaporative fuel generated in a fuel tank of an internal combustion engine, an apparatus for connecting a canister containing an adsorbent such as activated carbon to the fuel tank is known. In such a device, a blocking valve for sealing the fuel tank may be provided in a passage for communicating the canister and the fuel tank (see, for example, Patent Documents 1 to 3).

  For example, Patent Document 1 discloses a technique that enables efficient processing of evaporated fuel by adjusting the flow rate of evaporated fuel by adjusting the opening of a blocking valve. Patent Document 2 discloses a technique that enables oiling work to be started at an early stage by lowering the pressure in the canister with a pump during refueling. Patent Document 3 discloses a technique for shortening the waiting time that occurs during refueling by controlling opening and closing of the blocking valve so that the pressure in the fuel tank is close to atmospheric pressure during operation of the internal combustion engine. ing.

JP 2008-184910 A JP 2006-299994 A JP 2004-156696 A

  In the evaporative fuel processing apparatus provided with the block valve as described above, the pressure in the fuel tank increases due to the generation of the evaporated fuel in the fuel tank during the period when the seal valve is closed, and the fuel tank and the canister The pressure difference with is increasing. For this reason, when the blocking valve is opened, a larger amount of evaporated fuel than the canister can adsorb per unit time flows into the canister from the fuel tank per unit time (that is, per unit time of the canister). There is a technical problem in that a large amount of evaporated fuel exceeding the adsorption capacity instantaneously flows from the fuel tank into the canister, and the evaporated fuel may leak from the canister's atmospheric port to the atmosphere.

  The present invention has been made in view of the above-described problems, for example, and an object of the present invention is to provide an evaporative fuel processing apparatus capable of suppressing leakage of evaporative fuel to the atmosphere accompanying the opening of the block valve.

In order to solve the above-described problems, an evaporative fuel processing apparatus of the present invention has a canister that can adsorb evaporative fuel generated in a fuel tank that stores fuel of an internal combustion engine, an evaporative fuel passage that communicates the fuel tank and the canister, and A sealing valve that is an electromagnetic valve provided in the evaporative fuel passage and capable of opening and closing the evaporative fuel passage, a specifying means for specifying a pressure in the fuel tank, and a specific pressure specified by the specifying means is a predetermined pressure When the reference pressure is equal to or higher than the reference pressure, the inflow amount of the evaporated fuel flowing from the fuel tank to the canister per unit time is reduced so that the pressure in the fuel tank decreases to a predetermined target pressure. so as not to exceed the adsorbable moment adsorption capacity per unit time, closing valve system for controlling opening and closing the shutoff valve based at least on the specific pressure And means.

  According to the evaporated fuel processing apparatus of the present invention, the fuel tank can be sealed by the sealing valve provided in the evaporated fuel passage, and the so-called sealed fuel tank system is configured together with the fuel tank. During operation of the fuel vapor processing apparatus of the present invention, the pressure in the fuel tank (hereinafter referred to as “tank internal pressure” as appropriate) is specified by the specifying means. It should be noted that “specific” according to the present invention is a concept that comprehensively establishes the degree of authenticity as information that can be finally referred to for control, such as detection, calculation, estimation, identification, derivation, selection, and acquisition. However, the process for that purpose is not limited in any way. For example, the identification means may be various detection means such as a pressure sensor, or may be a means capable of acquiring the tank internal pressure as an electric signal or the like as a detection result from the various detection means. Based on other index values, physical quantities, or control quantities whose correspondence is known experimentally, empirically, theoretically or by simulation, for example, by selecting a corresponding value from a map or the like, or for example performing various arithmetic processes It may be a means for estimating by applying.

  Particularly in the present invention, when the tank internal pressure is equal to or higher than a predetermined reference pressure, the blocking valve control means is configured so that the pressure in the fuel tank decreases to a predetermined target pressure, and from the fuel tank to the canister for a unit time. The closing valve is controlled to open and close based on at least the pressure specified by the specifying means so that the inflow amount of the evaporated fuel that flows in at a time does not exceed the instantaneous adsorbable amount that can be adsorbed per unit time of the canister. For example, when the tank internal pressure specified by the specifying means is equal to or higher than a predetermined reference pressure, the block valve control unit intermittently sets the block valve until the tank internal pressure decreases to a predetermined target pressure. The blocking valve is controlled to open and close so that the valve is opened during each of the reference valve opening periods. In other words, the blocking valve control means opens the blocking valve in order to cause the evaporated fuel in the fuel tank to flow into the canister and adsorb the evaporated fuel to the canister when the tank internal pressure exceeds a predetermined reference pressure. The blocking valve is controlled so as to be in a state. At this time, the closing valve is controlled to be opened and closed so that the blocking valve is intermittently opened every predetermined reference valve opening period.

  Therefore, it is possible to suppress or prevent the evaporated fuel exceeding the instantaneous adsorption capacity of the canister from flowing into the canister from the fuel tank, and to prevent the evaporated fuel flowing into the canister from leaking into the atmosphere from the canister air port. Can be prevented. Further, since the evaporated fuel flowing into the canister does not exceed the instantaneous adsorption capacity of the canister, the evaporated fuel can be adsorbed to the adsorbent such as activated carbon contained in the canister efficiently or substantially uniformly. It is possible to reduce or prevent the material from being partially biased and deteriorated.

  In one aspect of the evaporated fuel processing apparatus of the present invention, the blocking valve control means controls opening and closing of the blocking valve so that the blocking valve is intermittently opened.

  According to this aspect, when the tank internal pressure becomes equal to or higher than the predetermined reference pressure, the closing valve is controlled to be opened and closed by the closing valve control means so as to be intermittently opened for each predetermined reference valve opening period. The It should be noted that the predetermined reference valve opening period is such that, for example, the amount of evaporative fuel that flows from the fuel tank to the canister per unit time when the blocking valve is opened does not exceed the instantaneous adsorption capacity of the canister. The period is set experimentally, empirically or theoretically or by simulation.

  Therefore, it is possible to reliably suppress or prevent the evaporated fuel that has flowed into the canister from leaking from the atmospheric port of the canister to the atmosphere.

  In the aspect in which the sealing valve control means described above controls the opening and closing of the sealing valve so that the sealing valve is intermittently opened, the purge passage for communicating the intake passage of the internal combustion engine and the canister, and the purge A purge control valve provided in the passage and capable of opening and closing the purge passage; and the evaporated fuel adsorbed to the canister every opening period in which the blocking valve is opened intermittently by the blocking valve control means And calculating the total adsorption amount of the evaporated fuel adsorbed by the canister by calculating the adsorption amount for each valve opening period, and calculating by the calculation unit When the total adsorption amount reaches a predetermined adsorption limit amount, the internal combustion engine is controlled so that the internal combustion engine is started, and the purge control valve is opened. It may further comprise a purge control means for controlling the over-di control valve.

  According to this configuration, every time the valve opening period in which the blocking valve is intermittently opened, the amount of evaporated fuel adsorbed by the canister during the valve opening period and the total amount of evaporated fuel adsorbed by the canister When the calculated total adsorption amount reaches a predetermined adsorption limit amount, the internal combustion engine is started by the purge control unit and the purge control valve is opened. Thus, the purge process is executed. Therefore, it is possible to more reliably suppress or prevent the evaporated fuel that has flowed into the canister from leaking out of the canister into the atmosphere. The predetermined adsorption limit amount is based on, for example, the total amount of evaporated fuel that can be adsorbed by the canister, experimentally, empirically, theoretically, or by simulation as the total amount of evaporated fuel to be purged. Is set.

  In the aspect in which the blocking valve control means controls the opening and closing of the blocking valve so that the blocking valve is intermittently opened, the blocking valve control means intermittently opens the blocking valve. The valve opening period may be changed according to the fuel property of the fuel in the fuel tank.

  According to this configuration, for example, winter fuel (ie, winter fuel) having higher volatility (ie, easier to evaporate) than summer fuel (ie, summer fuel) is stored in the fuel tank in summer. In such a case, the closing valve control means makes the valve opening period for intermittently opening the closing valve shorter than the valve opening period when summer fuel is stored in the fuel tank in summer. To do. Therefore, it is possible to more reliably suppress or prevent the fuel vapor exceeding the instantaneous adsorbable amount of the canister from flowing into the canister from the fuel tank. Therefore, the evaporative fuel that has flowed into the canister can be more reliably suppressed or prevented from leaking from the atmospheric port of the canister to the atmosphere. The “fuel property” according to the present invention means the degree of evaporating fuel (that is, volatility).

  The effect | action and other gain of this invention are clarified from the form for implementing invention demonstrated below.

It is a mimetic diagram of a vehicle provided with an evaporation fuel processing device concerning a 1st embodiment. It is a flowchart which shows the flow of the opening / closing control of the blocking valve in 1st Embodiment. It is a flowchart which mainly shows the flow of calculation of the adsorption amount in 1st Embodiment. It is a flowchart which shows the flow of control of execution of the purge process in 1st Embodiment. It is a graph which shows the relationship between the adsorption amount of the fuel vapor adsorbed by the canister, and the purge amount. It is a graph which shows a time-dependent change of the tank internal pressure after the opening / closing control of a blocking valve was started, and the total adsorption amount of the vaporization fuel adsorbed by the canister. It is a graph which shows the relationship between the amount of oil supply, and the adsorption amount of the evaporative fuel adsorbed by the canister. It is a schematic diagram of the vehicle provided with the evaporative fuel processing apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the flow of the opening / closing control of the blocking valve in 2nd Embodiment. When the closing valve opening period is set to a predetermined reference opening period β, the tank internal pressure after the opening / closing control of the closing valve is started and the total adsorption amount of the evaporated fuel adsorbed by the canister over time It is a graph which shows a change. It is a graph which shows the relationship between the amount of fuel supply, and the adsorption amount of the evaporative fuel adsorbed by the canister in the case where the fuel in a fuel tank is winter fuel and the case where it is summer fuel. It is a graph for demonstrating opening and closing control of the blocking valve in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
The evaporated fuel processing apparatus according to the first embodiment will be described with reference to FIGS. 1 to 7.

  First, an overall configuration of a vehicle provided with an evaporated fuel processing apparatus according to the present embodiment will be described with reference to FIG.

  FIG. 1 is a schematic view of a vehicle equipped with an evaporated fuel processing apparatus according to this embodiment.

  In FIG. 1, a vehicle 10 equipped with an evaporated fuel processing apparatus according to the present embodiment includes an engine 200, a motor generator 600, a fuel tank 300, a canister 400, and an ECU 100.

  The vehicle 10 is configured as a so-called parallel type hybrid vehicle in which an engine 200 and a motor generator 600 that functions as an electric motor and a generator are mounted as driving sources for traveling. Engine 200 and motor generator 600 are connected to each other via a power transmission mechanism (not shown). The vehicle 10 performs HV (hybrid vehicle) traveling that travels by the driving force of both the engine 200 and the motor generator 600 and EV (Electric Vehicle) traveling that travels by the driving force of the motor generator 600 only when the engine 200 is stopped. It can be selectively performed. The vehicle 10 may be a vehicle that uses only the engine 200 as a drive source.

  The engine 200 is an example of an “internal combustion engine” according to the present invention, and is a gasoline engine that uses gasoline as fuel and is configured to function as one of the drive sources of the vehicle 10. The engine 200 burns an air-fuel mixture of fuel and intake air (that is, air guided from the outside) inside the cylinder, and converts the internal piston motion generated according to the explosive force into a rotational motion, thereby converting the vehicle 10. Is configured to be drivable. The engine 200 is not limited to a gasoline engine, and may be a diesel engine using light oil as a fuel or a bi-fuel engine that can use a mixed fuel of alcohol and gasoline.

  The engine 200 is provided with an intake passage 210 for guiding intake air from the outside to the inside of the cylinder. An air cleaner 220 is disposed in the intake passage 210 to purify air sucked from the outside. A throttle valve 212 for adjusting the amount of intake air into the cylinder is disposed on the downstream side (cylinder side) of the air cleaner 220 in the intake passage 210. In the engine 200, the intake air sucked from the outside by the intake passage 210 and the fuel injected from the injector 214 which is a fuel injection device are mixed (that is, an air-fuel mixture is formed), and this air-fuel mixture is combusted. .

  The fuel tank 300 is a fuel tank for storing the fuel of the engine 200. The fuel tank 300 is provided with an inlet pipe 310 that is a pipe for supplying fuel into the fuel tank 300. A fuel cap 312 is detachably attached to the oil filler port 311 of the inlet pipe 310. A check valve 313 that prevents the fuel in the fuel tank 300 from flowing back through the inlet pipe 310 and flowing from the fuel tank 300 toward the fuel filler 311 is provided at the end of the inlet pipe 310 opposite to the fuel filler 311. It has been. A vent line 320 is connected in the vicinity of the oil filler port 311 of the inlet pipe 310. The vent line 320 is provided in order to return the evaporated fuel in the fuel tank 300 to the vicinity of the fuel inlet 311 of the inlet pipe 310 and reduce the amount of air entering the fuel tank 300 from the fuel inlet 11 during fueling.

  A fuel pump 330 and a remaining amount sensor 340 are disposed in the fuel tank 300. The fuel pump 330 is a pump device configured to suck up fuel stored in the fuel tank 300. A feed pipe 350 reaching the injector 214 of the engine 200 is connected to the fuel pump 330, and fuel sucked up by the fuel pump 330 is supplied to the injector 214 via the feed pipe 350. The remaining amount sensor 340 is a float type liquid level sensor, and is configured to detect the remaining amount of fuel in the fuel tank 300 (hereinafter referred to as “fuel remaining amount” appropriately). . The remaining amount sensor 340 is electrically connected to the ECU 100 described later. The remaining amount of fuel detected by the remaining amount sensor 340 is referred to by the ECU 100 at a constant or indefinite period.

  Connected to the upper part of the fuel tank 300 is an evaporation line 360 that is an example of an “evaporated fuel passage” according to the present invention, which communicates a canister 400 described later and a fuel liquid level upper space in the fuel tank 300. An ORVR valve (Onboard refueling vapor recovery valve) 371 and a COV (Cut Off Valve) 372 are provided at a connection portion between the evaporation line 360 and the fuel tank 300. The ORVR valve 371 is configured to close when the liquid level rises during refueling, and to block communication between the evaporation line 360 and the fuel tank 300. Further, the ORVR valve 371 is configured to block the communication between the evaporation line 360 and the fuel tank 300 even when the vehicle falls or the like, and the fuel in the fuel tank 300 does not leak to the outside via the evaporation line 360. ing. The COV 372 is arranged in parallel with the ORVR valve 371 and is configured to block communication between the evaporation line 360 and the fuel tank 300 when the liquid level rises further than the ORVR valve 371. The COV 372 maintains the open state even after the ORVR valve 372 is closed when the liquid level rises during refueling. However, the COV 372 is closed when the liquid level reaches the COV 372 due to the fluctuation of the liquid level caused by turning of the vehicle. The communication between the evaporation line 360 and the fuel tank 300 is cut off, and the fuel in the fuel tank 300 is not leaked to the outside through the evaporation line 360.

  On the upper surface of the fuel tank 300, a pressure sensor 345, which is an example of the “specifying means” according to the present invention, is provided. The pressure sensor 345 is a pressure sensor configured to be able to detect the pressure in the fuel tank 300 (that is, the tank internal pressure). The pressure sensor 345 is electrically connected to the ECU 100. The tank internal pressure detected by the pressure sensor 345 is referred to by the ECU 100 at a constant or indefinite period.

  A fuel temperature sensor 346 is provided on the lower surface of the fuel tank 300. The fuel temperature sensor 346 is a temperature sensor configured to be able to detect the temperature of the fuel in the fuel tank 300 (hereinafter referred to as “fuel temperature” as appropriate). The fuel temperature sensor 346 is electrically connected to the ECU 100. The fuel temperature detected by the fuel temperature sensor 346 is referred to by the ECU 100 at a constant or indefinite period.

  The evaporation line 360 is provided with a valve member 380. The valve member 380 includes a blocking valve 381 provided in the evaporation line 360, a bypass passage 389 provided to bypass the blocking valve 381 with respect to the evaporation line 360, and a mechanical valve 382 provided in the bypass passage 389. doing.

  The blocking valve 381 is an electromagnetic valve configured to be able to open and close the evaporation line 360 by an opening / closing operation. When the closing valve 381 is in the closed state, the evaporation line 360 is closed (that is, blocked), and the communication between the fuel tank 300 and the canister 400 is blocked. When the blocking valve 381 is in the open state, the evaporation line 360 is opened (that is, opened), and the fuel tank 300 and the canister 400 communicate with each other. The closing valve 381 is electrically connected to the ECU 100, and its opening / closing operation is controlled by the ECU 100 (more specifically, the closing valve control unit 120 described later).

  The mechanical valve 382 is not connected to the ECU 100, and is configured to open when the pressure on the fuel tank 300 side of the mechanical valve 382 in the bypass passage 389 is equal to or higher than a predetermined valve opening pressure.

  The canister 400 is an adsorption device provided with an adsorbent 410 such as activated carbon capable of adsorbing and holding the evaporated fuel (that is, vapor) generated in the fuel tank 300 therein. The canister 400 is connected to three types of pipes, the above-described evaporation line 360, the atmosphere communication pipe 420, and the purge pipe 430.

  The atmosphere communication pipe 420 is a tubular member that communicates the space outside the vehicle 10 (in other words, the atmosphere) with the canister 400. The atmosphere communication pipe 420 is evaporated by the adsorbent 410 out of the gas flowing into the canister 400 via the evaporation line 360 when a purge control valve 440 described later is closed and the above-described blocking valve 381 is opened. The clean air remaining after the adsorption of the fuel is guided to the outside of the vehicle, and when the purge control valve 440 is opened and the blocking valve 3381 is closed, the outside air is guided to the canister 400 from the outside of the vehicle. Yes.

  The purge pipe 430 is an example of a “purge passage” according to the present invention. One end is connected to the lower side of the canister 400 and the other end is connected to the downstream side of the throttle valve 212 in the intake passage 210. Is the passage.

  Here, the “purge gas” is a mixture of the outside air appropriately guided through the atmosphere communication pipe 420 and the evaporated fuel adsorbed and held by the adsorbent 410 (that is, if the adsorption amount of the evaporated fuel is zero, the outside air Itself). Such purge gas is supplied to the intake passage 210 via the purge pipe 430 during operation of the engine 200, and the evaporated fuel contained in the purge gas is used for combustion in the engine 200. Hereinafter, a series of processes in which the evaporated fuel adsorbed by the canister 400 is used for combustion in the engine 200 as described above is appropriately referred to as “purge process”.

  The purge pipe 430 is provided with a purge control valve 440 that is a VSV (Vacuum Switching Valve). The purge control valve 440 is an example embodiment that corresponds to the “purge control valve” according to the present invention. The valve body of the purge control valve 440 is a directional concept based on the flow direction of the purge gas when the engine 200 is not in operation, the upstream side and the downstream side of the purge control valve 440 (the upstream side and the downstream side in this case). The upstream side means the canister 440 side, and the downstream side means the intake passage 210 side), and is biased by an elastic body such as a coil spring so as to stop at a blocking position where the communication with the upstream side is blocked. On the other hand, when the engine 200 is in an operating state, a negative pressure is formed in the intake passage 210 mainly during the intake stroke. Due to this negative pressure, the valve body position of the purge control valve 440 as VSV is changed from the shut-off position, and the upstream side and the downstream side of the purge control valve 440 communicate with each other. As a result, the outside air is guided by the engine negative pressure through the atmosphere communication pipe 420, and the outside air is appropriately mixed with the evaporated fuel held in the adsorbent 410 on the way to the purge pipe 430, The above-described purge gas is supplied to the intake passage 210 through the purge pipe 430. The purge control valve 440 is electrically connected to the ECU 100, and its opening / closing operation is controlled by the ECU 100 (more specifically, a purge control unit 130 described later). The purge control valve 440 is configured as a VSV in the present embodiment, but the configuration is not limited to the VSV. The purge control valve 440 may be configured as, for example, an electromagnetically controlled valve device including a valve body that is driven by an electromagnetic actuator or the like.

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and is configured to be able to control the entire operation of the vehicle 10.

  Particularly in the present embodiment, the ECU 100 includes an adsorption amount calculation unit 110, a blocking valve control unit 120, and a purge control unit 130.

  The adsorption amount calculation unit 110 canister 400 (every time is referred to as “blocking valve opening period” as appropriate) during which the closing valve 381 is intermittently opened by the closing valve control unit 120 described later. More specifically, the adsorption amount of the evaporated fuel adsorbed by the adsorbent 410) is calculated, and the calculated adsorption amount for each closing valve opening period is integrated to adsorb the canister 400. The total adsorption amount of the evaporated fuel can be calculated.

  More specifically, the adsorption amount calculation unit 110 first determines the fuel temperature detected by the fuel temperature sensor 346, the remaining fuel amount detected by the remaining amount sensor 340, and the tank internal pressure detected by the pressure sensor 345. The evaporation in the fuel tank 300 based on the volume of the space in the fuel tank 300 (that is, the volume excluding the volume occupied by the remaining amount of fuel in the volume in the fuel tank 300; hereinafter referred to as “space volume” as appropriate). The fuel concentration (hereinafter referred to as “evaporated fuel concentration” as appropriate) is calculated. Next, the adsorption amount calculation unit 110 calculates the inflow amount (that is, the flow rate) of the evaporated fuel per unit time flowing from the fuel tank 300 to the canister 400 during the closing valve opening period based on the calculated evaporated fuel concentration. calculate. Next, the adsorption amount calculation unit 110 calculates the adsorption amount of the evaporated fuel that is adsorbed by the canister 400 during the closing valve opening period based on the calculated flow rate and the length of the closing valve opening period. The adsorption amount calculation unit 110 calculates the total adsorption amount of the evaporated fuel adsorbed on the canister 400 by accumulating the adsorption amount of the evaporated fuel calculated for each block valve opening period. In the following, a value corresponding to the total adsorption amount of the evaporated fuel adsorbed on the canister 400 calculated by accumulating the adsorption amount for each closing valve opening period by the adsorption amount calculation unit 110 is referred to as “adsorption”. It is appropriately referred to as “quantity integrated value”.

  The blocking valve control unit 120 is configured to be able to open and close the blocking valve 381. When the tank internal pressure is equal to or higher than a predetermined reference pressure, the blocking valve control unit 120 evaporates so that the tank internal pressure decreases to a predetermined target pressure and flows from the fuel tank 300 to the canister 400 per unit time. The blocking valve 381 is controlled to open and close so that the inflow amount of fuel does not exceed the instantaneous adsorbable amount that can be adsorbed per unit time of the canister 400. At this time, the blocking valve control unit 120 controls the opening and closing of the blocking valve 381 so that the blocking valve 381 is intermittently opened. The closing valve control unit 120 controls opening / closing of the closing valve 381 based on at least the tank internal pressure detected by the pressure sensor 345.

  The purge control unit 130 is configured to be able to control execution of the purge process described above. Specifically, the purge control unit 130 performs purge when the total adsorbed amount of evaporated fuel (that is, the adsorbed amount integrated value) calculated by the adsorbed amount calculating unit 110 reaches a predetermined adsorption limit amount. The engine 200 and the purge control valve 440 are controlled so that the processing is executed. That is, the purge control unit 130 controls the engine 200 so that the engine 200 starts when the adsorption amount integrated value calculated by the adsorption amount calculation unit 110 reaches a predetermined adsorption limit amount, and also performs purge control. The purge control valve 440 is controlled so that the valve 440 is opened.

  Next, the operation of the fuel vapor processing apparatus according to this embodiment will be described with reference to FIGS. 2 to 7 in addition to FIG.

  First, opening / closing control of the blocking valve in the evaporated fuel processing apparatus according to the present embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 2 is a flowchart showing a flow of opening / closing control of the blocking valve in the present embodiment.

  In FIG. 2, first, the ECU 100 determines whether or not the vehicle 10 is traveling on an EV (step S100).

  If it is determined that the vehicle is not traveling in EV (step S100: No), the subsequent operation process is not performed and the process ends. That is, the blocking valve 381 is kept closed by the blocking valve control unit 120.

  On the other hand, when it is determined that the vehicle is traveling in EV (step S100: Yes), the ECU 100 determines whether or not the tank internal pressure is equal to or higher than a predetermined reference pressure A [kPa] (step S110).

  When it is determined that the tank internal pressure is not equal to or higher than the predetermined reference pressure A (that is, the tank internal pressure is less than the predetermined reference pressure A) (step S110: No), the subsequent operation process is not performed and the process ends. That is, the blocking valve 381 is kept closed by the blocking valve control unit 120.

  On the other hand, when it is determined that the tank internal pressure is equal to or higher than the predetermined reference pressure A (step S110: Yes), the adsorption amount calculation execution flag is turned on by the ECU 100 (step S120). Here, the adsorption amount calculation execution flag is a flag indicating whether or not the adsorption amount calculation unit 110 of the ECU 100 calculates the adsorption amount. When the adsorption amount calculation execution flag is in the ON state, the adsorption amount When the calculation of the adsorption amount by the calculation unit 110 is executed and the adsorption amount calculation execution flag is OFF, the calculation of the adsorption amount by the adsorption amount calculation unit 110 is not executed. The calculation of the adsorption amount by the adsorption amount calculation unit 110 will be described later with reference to FIG.

  Next, the ECU 100 turns on the blocking valve drive flag (step S130). Here, the block valve driving flag is a flag indicating whether or not the block valve 381 is controlled to be opened and closed by the block valve control unit 120 of the ECU 100. When the block valve driving flag is in the ON state, the block valve control flag is controlled. When the block valve 381 is controlled to be opened and closed by the unit 120, and the block valve drive flag is OFF, the block valve 381 is not controlled by the block valve control unit 120 and the block valve 381 is controlled. The valve 120 is kept closed by the section 120.

  When the blocking valve drive flag is turned on (step S130), the opening / closing control of the blocking valve 381 by the blocking valve control unit 120 is started (step S140). That is, the closing valve control unit 120 operates the closing valve 381 to open the closing valve 381 that has been closed.

  Next, the blocking valve control unit 120 determines whether or not the closing valve opening period is equal to or longer than a predetermined reference opening period α [second] (step S150). That is, the blocking valve control unit 120 determines whether or not a predetermined reference valve opening period α has elapsed since the blocking valve 381 that was in the closed state has been opened.

  When it is determined that the closing valve opening period is not equal to or longer than the predetermined reference opening period α (that is, the closing valve opening period is less than the predetermined opening period α) (step S150: No), the step is again performed. The operation process according to S130 is performed by the ECU 100.

  On the other hand, when it is determined that the closing valve opening period is equal to or longer than the predetermined reference opening period α (step S150: Yes), the closing valve control unit 120 closes the closing valve 381 in the opened state again. After setting the valve state, it is determined whether or not the tank internal pressure is equal to or lower than a predetermined target pressure B [kPa] or the adsorption amount integrated value D is equal to or greater than a predetermined adsorption limit amount X (step S160).

  The tank internal pressure is less than or equal to the predetermined target pressure B, or the adsorption amount integrated value D is not greater than or equal to the predetermined adsorption limit amount X (that is, the tank internal pressure is greater than the predetermined target pressure B and the adsorption integrated value D is the predetermined adsorption). If it is determined that it is smaller than the limit amount (step S160: No). The operation process according to step S130 is performed again by the ECU 100. That is, the opening / closing control of the blocking valve 381 by the blocking valve control unit 120 is continued. That is, the blocking valve control unit 120 determines that the tank internal pressure is equal to or lower than the predetermined target pressure B or the adsorption amount integrated value D is equal to or higher than the predetermined adsorption limit amount X (in other words, the tank internal pressure is higher than the predetermined target pressure B). The block valve 381 is opened so that the block valve 381 is intermittently opened by a predetermined reference valve open period α during a period of time during which the integrated adsorption value D is larger and smaller than the predetermined adsorption limit amount. Open / close control.

  On the other hand, when it is determined that the tank internal pressure is equal to or lower than the predetermined target pressure B, or the adsorption amount integrated value D is equal to or greater than the predetermined adsorption limit amount X (step S160: Yes), the ECU 100 sets the adsorption amount calculation execution flag. The OFF state is set, and the calculation of the adsorption amount by the adsorption amount calculation unit 110 ends (step S170). Subsequently, the ECU 100 sets the blocking valve drive flag to the OFF state (step S180), and the opening / closing control of the blocking valve 381 by the blocking valve control unit 120 is stopped (step S190). At this time, the blocking valve 381 is closed.

  Next, calculation of the adsorption amount by the adsorption amount calculation unit 110 and control of execution of the purge process by the purge control unit 130 will be described with reference to FIGS. 3 and 4.

  FIG. 3 is a flowchart mainly showing a flow of calculation of the adsorption amount by the adsorption amount calculation unit 110.

  In FIG. 3, the adsorption amount calculation unit 110 determines whether or not the above-described adsorption amount calculation execution flag is ON (step 200).

  When it is determined that the adsorption amount calculation execution flag is not in the ON state (that is, in the OFF state) (step S200: No), the calculation of the adsorption amount by the adsorption amount calculation unit 110 is not executed.

  On the other hand, when it is determined that the adsorption amount calculation execution flag is in the ON state (step S200: Yes), the calculation of the adsorption amount by the adsorption amount calculation unit 110 is started, and first, the fuel remaining amount is measured ( Step S210). That is, the remaining fuel amount detected by the remaining amount sensor 340 is referred to by the adsorption amount calculation unit 110.

  Subsequently, the fuel temperature in the fuel tank 300 is measured (step S220). That is, the fuel temperature detected by the fuel temperature sensor 346 is referred to by the adsorption amount calculation unit 110.

  Next, the evaporated fuel concentration in the fuel tank 300 is calculated by the adsorption amount calculation unit 110 (step S230).

  Next, the flow rate of the evaporated fuel (that is, the inflow amount of evaporated fuel per unit time flowing from the fuel tank 300 to the canister 400) during the closing valve opening period is calculated by the adsorption amount calculation unit 110 (step S240). .

  Next, the adsorption amount of the evaporated fuel during the closing valve opening period is calculated by the adsorption amount calculation unit 110 (step S250). That is, the adsorption amount calculation unit 110 opens the blocking valve based on the flow rate calculated by the operation process in step S240 and the length of the closing valve opening period (in other words, the length of the predetermined reference opening period α). The amount of evaporated fuel adsorbed by the canister 400 during the valve period is calculated. At this time, the adsorption amount calculation unit 110 calculates the adsorption amount integrated value D by integrating the adsorption amount of the evaporated fuel calculated for each block valve opening period.

  Next, the ECU 100 determines whether or not the adsorption amount integrated value D is equal to or greater than the adsorption limit amount X (step S260). Here, the adsorption limit amount X is a preset amount as the total adsorption amount of the evaporated fuel to be purged, and the evaporated fuel that canisters can adsorb experimentally, empirically, theoretically or by simulation. Is set based on the total amount.

  When it is determined that the adsorption amount integrated value D is equal to or larger than the adsorption limit amount X (step S260: Yes), the adsorption limit amount determination flag is turned on by the ECU 100 (step S270). Here, the adsorption limit amount determination flag indicates whether or not the adsorption amount of the evaporated fuel adsorbed on the canister 400 is equal to or greater than the adsorption limit amount X, in other words, whether or not the purge process by the purge control unit 130 is executed. When the adsorption limit amount determination flag is ON, purge processing by the purge control unit 130 is executed, and when the adsorption limit amount determination flag is OFF, the purge control unit 130 The purge process is not executed.

  On the other hand, when the adsorption amount integrated value D is not equal to or greater than the adsorption limit amount X (that is, the adsorption amount integrated value D is less than the adsorption limit amount X) (step S260: No), the adsorption limit amount determination flag is in the ON state. In other words, the purge control unit 130 does not execute the purge process.

  FIG. 4 is a flowchart showing a flow of control of execution of purge processing by the purge control unit 130.

  In FIG. 4, first, the purge control unit 130 determines whether or not the adsorption limit amount determination flag described above is in an ON state (step S300).

  When it is determined that the adsorption limit amount determination flag is not in the ON state (that is, in the OFF state) (step S300: No), the purge process by the purge control unit 130 is not executed.

  On the other hand, when it is determined that the adsorption limit amount determination flag is in the ON state (step S300: Yes), the engine 200 is started by the purge control unit 130 (step S310). That is, the purge control unit 130 controls the engine 200 so that the engine 200 is started. That is, when the vehicle 10 is traveling in EV and the engine 200 is stopped, if it is determined that the adsorption limit amount determination flag is in the ON state, the engine 200 is controlled to perform purge control in order to execute the purge process. It is started by the unit 130.

  Next, a purge process is executed by the purge control unit 130 (step S320). That is, the purge control unit 130 controls the purge control valve 440 so that the purge control valve 440 that has been closed is opened. Thereby, the purge process is executed.

  Next, the purge control unit 130 determines whether or not the purge amount Qp [L (liter)] is equal to or greater than the required purge amount C [L] (step S330). Here, the purge amount Qp is the amount of evaporated fuel that is desorbed from the canister 400 by the execution of the purge process and is used for combustion in the engine 200. The purge amount Qp increases as the purge processing time is increased. The required purge amount C is previously set as the minimum amount of evaporated fuel that should be desorbed from the canister 400 by the purge process when the adsorption amount of the evaporated fuel adsorbed on the canister 400 is equal to or larger than the predetermined adsorption limit amount X. It is a fixed amount.

  FIG. 5 is a graph showing the relationship between the adsorption amount of the evaporated fuel adsorbed on the canister 400 and the purge amount.

  In FIG. 5, as the purge amount Qp increases, the adsorption amount of the evaporated fuel adsorbed on the canister 400 decreases. When the purge amount Qp is equal to or greater than the required purge amount C, the adsorption amount of the evaporated fuel adsorbed on the canister 400 is almost or completely zero in practice. In other words, the required purge amount C can be determined in advance as a purge amount at which the adsorption amount of the evaporated fuel adsorbed by the canister 400 is almost zero or practically zero.

  In FIG. 4 again, when it is determined that the purge amount Qp is greater than or equal to the required purge amount C (step S330: Yes), the purge process by the purge control unit 130 is terminated (step S340). That is, the purge control unit 130 closes the purge control valve 440 and stops the engine 200. That is, the purge control unit 130 controls the purge control valve 440 so that the purge control valve 440 is closed, and controls the engine 200 so that the engine 200 is stopped.

  On the other hand, when it is determined that the purge amount Qp is not equal to or greater than the required purge amount C (that is, less than the required purge amount C) (step S330: No), the purge process by the purge control unit 130 is not terminated and continues. Is done. That is, the purge process by the purge control unit 130 is continued until the purge amount Qp becomes equal to or greater than the necessary purge amount C.

  After the purge process by the purge control unit 130 is completed (step S340), the adsorption limit amount determination flag is turned off by the ECU 100 (step S350).

  Next, the opening / closing control of the blocking valve described above with reference to FIG. 2 and the calculation of the adsorption amount described above with reference to FIG. 3 will be described with reference to FIG.

  FIG. 6 is a graph showing changes with time in the tank internal pressure and the total adsorbed amount of evaporated fuel adsorbed on the canister 400 after the opening / closing control of the blocking valve is started. In addition, the horizontal axis of the graph shown in FIG. 6 is the time from the time when the opening / closing control of the blocking valve is started.

  In FIG. 6, a solid line L1 indicates a change over time in the tank internal pressure after the opening / closing control of the blocking valve 381 is started, and a solid line L2 is adsorbed on the canister 400 after the opening / closing control of the blocking valve 381 is started. It shows the change over time of the total amount of adsorbed evaporated fuel. As a comparative example, the alternate long and short dash line R1 shows a change over time in the tank internal pressure when the block valve 381 is opened and maintained when the tank internal pressure reaches a predetermined reference pressure A. Yes. As a comparative example, an alternate long and short dash line R2 indicates the amount of adsorbed evaporated fuel adsorbed on the canister 400 when the tank internal pressure reaches a predetermined reference pressure A and the blocking valve 381 is opened and maintained as it is. The change with time is shown.

  In FIG. 6, when the tank internal pressure becomes a predetermined reference pressure A (see the point m1 on the solid line L1), the opening / closing control of the blocking valve 381 is started. That is, as described above with reference to FIG. 2, particularly in this embodiment, when the tank internal pressure is equal to or higher than the predetermined reference pressure A, the blocking valve control unit 120 causes the tank internal pressure to be equal to or lower than the predetermined target pressure B. Or until the adsorption amount integrated value D becomes equal to or greater than the predetermined adsorption limit amount X (in other words, a period in which the tank internal pressure is larger than the predetermined target pressure B and the adsorption integrated value D is smaller than the predetermined adsorption limit amount). In the middle), the closing valve 381 is controlled to be opened and closed so that the closing valve 381 is intermittently opened by a predetermined reference valve opening period α.

  That is, when opening / closing control of the blocking valve 381 is started, the blocking valve 381 is first opened for a predetermined reference valve opening period α (the period during which the valve is opened is referred to as “first valve opening period”). "To1" as appropriate), the valve is closed for the following first valve closing period Tc1, and the valve is opened for the subsequent predetermined reference valve opening period α (the period during which this valve is opened is referred to as "second valve opening"). (Referred to as “time period To2”), the valve is closed during the subsequent second valve closing period Tc2, and is opened during the subsequent predetermined reference valve closing period α (the period during which this valve is opened is referred to as “third opening”). The valve period To3 "is appropriately called), the valve is closed only for the subsequent third valve closing period Tc3, and the valve is opened for the predetermined reference valve opening period α (the period during which this valve is opened is referred to as" the first valve opening period "). 4 valve opening period To4 "as appropriate).

As indicated by the solid line L1, in the first valve opening period To1, the block valve 381 is opened, so that the tank internal pressure decreases from the predetermined reference pressure A to the pressure P1, and in the first valve closing period Tc1. When the closing valve 381 is closed, the tank internal pressure increases from the pressure P1 to the pressure P2, and during the second valve opening period To2, the closing valve 381 is opened so that the tank internal pressure is increased from the pressure P2. Decrease to pressure P3. Thereafter, similarly, the tank internal pressure decreases while repeatedly increasing and decreasing according to the opening / closing control of the blocking valve 381, and after the fourth valve opening period To4, the tank internal pressure becomes the target pressure B (see the point m2 on the solid line L1). ).
As described above, particularly in the present embodiment, when the tank internal pressure is equal to or higher than the predetermined reference pressure A, the block valve control unit 120 opens the block valve 381 in order to allow the evaporated fuel to flow from the fuel tank 300 to the canister 400. When the valve state is set, the shutoff valve 381 is controlled to open and close so that the shutoff valve 381 is intermittently opened at a predetermined reference valve opening period α, so that the fuel tank 300 flows into the canister 400 per unit time. It is possible to suppress or prevent the inflow amount of the evaporated fuel from exceeding the instantaneous adsorbable amount of the canister 400 (that is, the amount of evaporated fuel that canister 400 can adsorb per unit time). Therefore, it is possible to suppress or prevent the evaporated fuel flowing into the canister 400 from the fuel tank 300 from leaking to the atmosphere via the atmosphere communication path 420 that is the atmosphere port of the canister 400.

  Further, as described above, the opening / closing control is performed by the closing valve control unit 120 so that the closing valve 381 is intermittently opened for each predetermined reference valve opening period α, so that, for example, the tank internal pressure becomes a predetermined target pressure. Compared to the case in which the blocking valve 381 is kept open until the evaporative fuel flows into the canister 400 by a small amount, the evaporative fuel is adsorbed to the adsorbent 410 of the canister 400 efficiently or substantially uniformly. It is possible to reduce or prevent the adsorbent 410 from being partially biased and deteriorated.

  In FIG. 6, as indicated by the solid line L2, each of the first valve opening period To1, the second valve opening period To2, the third valve opening period To3, and the fourth valve opening period To4 in which the blocking valve 381 is opened. The evaporative fuel flows into the canister 400 from the fuel tank 300, and the evaporative fuel that has flowed in is adsorbed by the canister 400. On the other hand, since the evaporated fuel does not flow from the fuel tank 300 to the canister 400 during the period when the blocking valve 381 is closed, the evaporated fuel is not adsorbed by the canister 400.

  In the present embodiment, in particular, as described above with reference to FIGS. 1 and 3, the adsorption amount calculation unit 110 calculates the adsorption amount for each block valve opening period, and integrates the calculated adsorption amount. Then, an adsorption amount integrated value D as a total adsorption amount of the evaporated fuel adsorbed on the canister 400 is calculated. In the example illustrated in FIG. 6, the adsorption amount calculation unit 110 at the end of the second valve opening period To2, the adsorption amount b1 of the evaporated fuel adsorbed on the canister 400 in the first valve opening period To1, and the second valve opening period. By integrating the adsorption amount b2 of the evaporated fuel adsorbed by the canister 400 at To2, the adsorption amount integrated value D is calculated. The adsorption amount calculation unit 110 is adsorbed by the canister 400 at the end time of the third valve opening period To3, and is adsorbed by the canister 400 during the first valve opening period To1 and the adsorption amount b1 of the evaporated fuel adsorbed by the canister 400 during the second valve opening period To2. The adsorption amount integrated value D is calculated by integrating the adsorption amount b2 of the evaporated fuel and the adsorption amount b3 of the evaporated fuel adsorbed by the canister 400 in the third valve opening period To3. At the end of the fourth valve opening period To4, the adsorption amount calculation unit 110 is adsorbed by the canister 400 during the first valve opening period To1 and the adsorption amount b1 of the evaporated fuel adsorbed by the canister 400 during the second valve opening period To2. The evaporated fuel adsorption amount b2, the evaporated fuel adsorption amount b3 adsorbed on the canister 400 in the third valve opening period To3, and the evaporated fuel adsorption amount b4 adsorbed on the canister 400 in the fourth valve opening period To4 are integrated. Thus, the adsorption amount integrated value D is calculated.

  That is, for example, at the end of the fourth valve opening period To4, the adsorption amount calculation unit 110 evaporates the adsorption amount integrated value D = adsorption amount b1 + adsorption amount b2 + adsorption amount b3 + adsorption amount b4 adsorbed by the canister 400. Calculated as the total amount of fuel adsorbed.

  Therefore, it is adsorbed by the canister 400 every block valve opening period (in the example of FIG. 6, every first valve opening period To1, second valve opening period To2, third valve opening period To3, and fourth valve opening period To4). The purge control unit 130 can refer to the adsorption amount integrated value D as the total adsorption amount of the evaporated fuel.

  The adsorption amount calculation unit 110 adsorbs the evaporated fuel adsorption amount adsorbed to the canister 400 when refueling is performed (hereinafter referred to as “adsorption amount during fueling” as appropriate) for each block valve opening period. It may be configured to add up to the quantity. That is, when the fuel supply is performed, the tank internal pressure becomes equal to or higher than the predetermined valve opening pressure, and the mechanical valve 382 described above with reference to FIG. 1 is opened, so that the fuel tank 300 passes the canister 400 via the mechanical valve 382. Thus, the adsorption amount E when the fuel vapor flows in and is adsorbed by the canister 400 may be included in the adsorption amount integrated value D. That is, for example, at the end of the above-described fourth valve opening period To4, the adsorption amount calculation unit 110 calculates the adsorption amount integrated value D = adsorption amount b1 + adsorption amount b2 + adsorption amount b3 + adsorption amount b4 + refueling adsorption amount E as a canister. It may be calculated as the total adsorption amount of the evaporated fuel adsorbed by 400.

  FIG. 7 is a graph showing the relationship between the fuel supply amount and the adsorption amount of the evaporated fuel adsorbed on the canister 400.

  As shown in FIG. 7, the greater the amount of fuel supplied (the amount of fuel supplied to the fuel tank 300 during refueling), the more evaporated fuel is generated in the fuel tank 300 and the amount of evaporated fuel adsorbed on the canister 400. (That is, the amount of adsorption E during refueling) also increases.

  As described above with reference to FIGS. 3 to 5, particularly in the present embodiment, the purge control unit 130 has the adsorption amount of the evaporated fuel calculated by the adsorption amount calculation unit 110 (that is, the adsorption amount integrated value D). If it is equal to or greater than the adsorption limit amount X, a purge process is executed (that is, the engine 200 is started and the purge control valve 440 is opened).

  Therefore, the evaporated fuel flows from the fuel tank 300 to the canister 400 in a state where the evaporated fuel of the predetermined adsorption limit amount X or more is adsorbed on the canister 400, so that the evaporated fuel flows into the atmosphere via the atmosphere communication pipe 420. Leakage can be avoided.

  As described above, according to the present embodiment, when the tank internal pressure is equal to or higher than the predetermined reference pressure A, the blocking valve 381 is opened to allow the evaporated fuel to flow from the fuel tank 300 to the canister 400. In this case, the closing valve control unit 120 controls the opening and closing of the closing valve 381 so that the closing valve 381 is intermittently opened every predetermined reference valve opening period α, so that the fuel tank 300 flows into the canister 400 per unit time. It is possible to suppress or prevent the inflow amount of the evaporated fuel from exceeding the instantaneous adsorbable amount of the canister 400. Therefore, it is possible to suppress or prevent the evaporated fuel flowing into the canister 400 from the fuel tank 300 from leaking to the atmosphere via the atmosphere communication path 420 that is the atmosphere port of the canister 400. Further, when the adsorption amount integrated value D calculated by the adsorption amount calculation unit 110 is equal to or larger than the adsorption limit amount X, the purge processing by the purge control unit 130 is executed, so that the fuel flows from the fuel tank 300 into the canister 400. It is possible to more reliably suppress or prevent the evaporated fuel from leaking to the atmosphere through the atmosphere communication path 420 of the canister 400.

Second Embodiment
Next, an evaporated fuel processing apparatus according to the second embodiment will be described with reference to FIGS.

  FIG. 8 is a schematic view of a vehicle including the evaporated fuel processing apparatus according to the second embodiment. In FIG. 8, the same components as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In FIG. 8, the evaporative fuel processing apparatus according to the second embodiment is further provided with a refueling time storage timer 700 and a block valve control unit in place of the block valve control unit 120 (see FIG. 1) in the first embodiment described above. The fuel vapor processing apparatus according to the first embodiment described above is different from the fuel vapor processing apparatus according to the first embodiment described above, and the other points are substantially the same as those of the fuel vapor processing apparatus according to the first embodiment described above.

  In FIG. 8, a refueling time storage timer 700 is a timer capable of storing a time point of last refueling (hereinafter referred to as “previous refueling time point” as appropriate) and measuring a period from the previous refueling time to the present time. The oiling time storage timer 700 is electrically connected to the ECU 100. The previous refueling time stored by the refueling time storage timer 700 and the measured period from the previous refueling time to the current time are referred to by the ECU 100 at a constant or indefinite period.

  The blocking valve control unit 120b determines the fuel property of the fuel in the fuel tank 300 based on the previous fueling time stored by the fueling time storage timer 700 and the measured period from the previous fueling time to the current time. Unlike the block valve control unit 120 in the first embodiment described above, the other points are different in that the block valve opening period in which the block valve 381 is intermittently opened is changed according to the fuel properties. The configuration is substantially the same as the closing valve control unit 120 in the first embodiment described above.

  More specifically, when the closing valve control unit 120b performs opening / closing control of the closing valve 381, whether or not the present time is summer and the previous refueling time is winter is stored by the refueling time storage timer 700. The determination is made based on the previous refueling time and the measured period from the previous refueling time to the present time. That is, the blocking valve control unit 120b determines whether or not the fuel in the fuel tank 300 is the fuel supplied in the winter (that is, the winter fuel) is carried over to the summer as it is. Further, the blocking valve control unit 120b sets a blocking valve opening period for intermittently opening the blocking valve 381 according to the determination result as a predetermined reference valve opening period α or the predetermined reference valve opening period. A predetermined reference valve opening period β shorter than the period α is set. Specifically, when it is determined that the present time is summer and the previous refueling time is winter, the block valve control unit 120b sets a block valve opening period for intermittently opening the block valve 381. A predetermined reference valve opening period β is set, and it is determined that the present time is summer and the previous refueling time is not winter (that is, the last refueling time is also summer, that is, the fuel in the fuel tank 300 is summer fuel). In this case, the closing valve opening period for intermittently opening the closing valve 381 is set to a predetermined reference opening period α. As described above, the closing valve control unit 120b is configured to change the closing valve opening period in which the closing valve is opened intermittently according to the fuel property in the fuel tank 300.

  Next, the opening / closing control of the blocking valve in the evaporated fuel processing apparatus according to the second embodiment will be described with reference to FIGS.

  FIG. 9 is a flowchart showing a flow of opening / closing control of the blocking valve in the second embodiment. In FIG. 9, the same reference numerals are assigned to the same operation processes as those according to the first embodiment shown in FIG. 2, and the description thereof will be omitted as appropriate.

  In FIG. 9, when it is determined that the tank internal pressure is equal to or higher than the predetermined reference pressure A (step S110: Yes), it is determined whether or not the current time is summer and the fuel in the fuel tank 300 is winter fuel. It is determined by the blocking valve control unit 120b (step S410). That is, the blockade valve control unit 120b determines whether the current time is summer and the previous refueling time is winter. At this time, as described above, the blocking valve control unit 120b determines based on the previous refueling time stored by the refueling time storage timer 700 and the measured period from the previous refueling time to the current time.

  When it is determined that the current time is summer and the fuel in the fuel tank 300 is winter fuel (step S410: Yes), the closing valve control unit 120b sets the closing valve opening period to a predetermined reference opening period. β is set (step S420). Note that the predetermined reference valve opening period β is shorter than the predetermined reference valve opening period α as described above.

  On the other hand, when it is determined that the current time is summer and the fuel in the fuel tank 300 is not winter fuel (that is, summer fuel), the closing valve control unit 120b sets the closing valve opening period to a predetermined standard. The valve opening period α is set (step S430).

  When the closing valve control unit 120b starts the opening / closing control of the closing valve 381 (step S140), is the closing valve opening period equal to or longer than the predetermined reference valve opening period α or β [seconds] set? It is determined whether or not (step S440). That is, the blockade valve control unit 120b determines whether or not a predetermined reference valve opening period α or β has elapsed since the blockade valve 381 that was in the closed state is opened.

  FIG. 10 shows a case where the closing valve opening period is set to a predetermined reference valve opening period β (that is, when the current time is summer and it is determined that the fuel in the fuel tank 300 is winter fuel). It is a graph of the same meaning as FIG.

  In FIG. 10, a solid line L3 indicates a change over time in the tank internal pressure after the closing valve opening / closing control is started, and a solid line L4 is adsorbed by the canister 400 after the closing valve opening / closing control is started. It shows the change over time of the total adsorption amount of the evaporated fuel.

  In FIG. 10, when the tank internal pressure becomes a predetermined reference pressure A (see the point m1 on the solid line L3), the opening / closing control of the blocking valve 381 is started. That is, when the tank internal pressure is equal to or higher than the predetermined reference pressure A, the block valve control unit 120b determines that the tank internal pressure is equal to or lower than the predetermined target pressure B, or the adsorption amount integrated value D is equal to or higher than the predetermined adsorption limit amount X. Until the closing valve 381 is intermittently opened and closed every predetermined reference valve opening period β, the closing valve 381 is controlled to open and close.

  That is, when the opening / closing control of the blocking valve 381 is started, the blocking valve 381 is first opened for a predetermined reference valve opening period β (the period during which the valve is opened is referred to as “first valve opening period”). This is referred to as “To1” as appropriate, and is closed during the subsequent first valve closing period Tc1, and is opened during the subsequent predetermined reference valve opening period β (the period during which this valve is opened is referred to as “second valve opening”). (Referred to as the period To2 ”), the valve is closed during the subsequent second valve closing period Tc2, and the valve is opened during the subsequent predetermined reference valve closing period β (the period during which this valve is opened is referred to as“ third opening ”). The valve period To3 ”is referred to as appropriate, and the valve is closed for the subsequent third valve closing period Tc3, and is opened for the subsequent predetermined reference valve opening period β (the period during which the valve is opened is referred to as“ fourth valve opening period ”). The valve opening period To4 "as appropriate), and the valve is closed during the subsequent fourth valve closing period Tc4. The valve is opened for the valve period β (the period for which the valve is opened is referred to as “fifth valve opening period To5” as appropriate), the valve is closed for the subsequent fifth valve closing period Tc5, and the predetermined reference is continued. The valve is opened only during the valve opening period β (this period when the valve is opened is appropriately referred to as “sixth valve opening period To6”).

  The adsorption amount calculation unit 110 calculates an adsorption amount for each closing valve opening period, and integrates the calculated adsorption amount, thereby obtaining an adsorption amount as a total adsorption amount of the evaporated fuel adsorbed on the canister 400. The integrated value D is calculated. In the example illustrated in FIG. 10, for example, at the end of the sixth valve opening period To6, the adsorption amount calculation unit 110 has the adsorption amount integrated value D = adsorption amount b1 + adsorption amount b2 + adsorption amount b3 + adsorption amount b4 + adsorption amount b5 + adsorption amount. b6 is calculated as the total adsorption amount of the evaporated fuel adsorbed by the canister 400. Further, the adsorption amount calculation unit 110 integrates the adsorption amount of the evaporated fuel adsorbed by the canister 400 when fueling is performed (that is, the adsorption amount at the time of fueling) to the adsorption amount for each closing valve opening period. May be configured. That is, for example, at the end of the above-described sixth valve opening period To6, the adsorption amount calculation unit 110 performs the adsorption amount integrated value D = adsorption amount b1 + adsorption amount b2 + adsorption amount b3 + adsorption amount b4 + adsorption amount b5 + adsorption amount b6 + refueling time. The adsorption amount E may be calculated as the total adsorption amount of the evaporated fuel adsorbed on the canister 400.

  FIG. 11 is a graph showing the relationship between the fuel supply amount and the adsorption amount of the evaporated fuel adsorbed on the canister 400 in comparison between the case where the fuel in the fuel tank 300 is winter fuel and the case where it is summer fuel. .

  As shown in FIG. 11, for example, winter fuel is more volatile than summer fuel, and therefore, when the fuel in the fuel tank 300 is winter fuel, it is adsorbed by the canister 400 than when it is summer fuel. Large amount of adsorption.

  Therefore, without taking any measures, the closing valve opening period for intermittently opening the closing valve is a fixed period (for example, corresponding to summer fuel) regardless of the fuel properties of the fuel in the fuel tank 300. When the current time is summer and the fuel in the fuel tank 300 is winter fuel, the canister 400 can be adsorbed instantaneously during the closing valve opening period. There is a possibility that the evaporated fuel exceeding the amount flows into the canister 400 from the fuel tank 300 or 300.

  However, according to the present embodiment, as described above, the closing valve control unit 120b determines that the current time is summer and the fuel in the fuel tank 300 is winter fuel, the closing valve opening period. Is set to a predetermined reference valve opening period β that is shorter than a predetermined reference valve opening period α (that is, a reference valve opening period when the fuel in the fuel tank 300 is summer fuel). In addition, it is possible to suppress or prevent the evaporated fuel exceeding the instantaneous adsorbable amount of the canister 400 from flowing into the canister 400 from the fuel tank 300. Therefore, it is possible to more reliably suppress or prevent the evaporated fuel that has flowed into the canister 400 from leaking from the atmospheric communication passage 420 of the canister 400 to the atmosphere.

<Third Embodiment>
A fuel vapor processing apparatus according to the third embodiment will be described with reference to FIG.

  In the fuel vapor processing apparatus according to the third embodiment, the closing valve control unit 120 (see FIG. 1) responds to the amount of fluctuation in the tank internal pressure (hereinafter referred to as “tank internal pressure change” as appropriate) during the closing valve opening period. Unlike the evaporated fuel processing apparatus according to the first embodiment described above, the remaining configuration is substantially the same as that of the evaporated fuel processing apparatus according to the first embodiment described above.

  FIG. 12 is a graph showing the relationship between the tank internal pressure change amount and the closing valve opening period for explaining the opening / closing control of the closing valve in the third embodiment.

  In FIG. 12, in this embodiment, when the closing valve control unit 120 performs opening / closing control for intermittently opening the closing valve 381, the closing valve control unit 120 is based on the tank internal pressure change amount during the immediately preceding closing valve opening period. Change the length of this blockade valve opening period. Specifically, when the tank internal pressure change amount during the immediately preceding closing valve opening period is the change amount ΔP1, the current closing valve opening period is set to the period TL, and during the immediately preceding closing valve opening period. In the case where the tank internal pressure change amount is a change amount ΔP2 larger than the change amount ΔP1, the current closing valve opening period is set to a period TM shorter than the period TL, and the tank during the immediately preceding closing valve opening period is set. When the internal pressure change amount is the change amount ΔP3 larger than the change amount ΔP2, the current closing valve opening period is set to a period TS shorter than the period TM. That is, in this embodiment, the closing valve control unit 120 sets the current closing valve opening period to periods TL and TM having different lengths according to the magnitude of the tank internal pressure change amount during the immediately preceding closing valve control period. And switch between TS. In other words, when the change in the tank internal pressure during the immediately preceding closing valve control period is relatively steep, the closing valve control unit 120 sets the current closing valve opening period to a relatively short period TS, If the change in the tank internal pressure during the shut-off valve control period is moderate, the current valve opening period is set to a medium length TM, and the tank internal pressure change during the previous shut-off valve control period Is relatively moderate, the current closing valve opening period is set to a relatively short period TS.

  According to the evaporated fuel processing apparatus according to the present embodiment configured as described above, therefore, the evaporated fuel exceeding the instantaneous adsorbable amount of the canister 400 can be more reliably suppressed or prevented from flowing into the canister 400 from the fuel tank 300. Can be prevented. Therefore, it is possible to more reliably suppress or prevent the evaporated fuel that has flowed into the canister 400 from leaking from the atmospheric communication passage 420 of the canister 400 to the atmosphere.

  In this embodiment, the configuration in which the closing valve opening period is set to any one of the three types of periods having different lengths has been described as an example. However, the closing valve opening periods have different lengths. You may comprise so that it may be set in either of several periods more than three types.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. The apparatus is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 100 ... ECU, 110 ... Adsorption amount calculation part, 120, 120b ... Sealing valve control part, 130 ... Purge control part, 200 ... Engine, 210 ... Intake passage, 300 ... Fuel tank, 340 ... Remaining amount sensor, 345 ... Pressure sensor, 346 ... Fuel temperature sensor, 360 ... Evaporation line, 380 ... Valve member, 381 ... Block valve, 382 ... Mechanical valve, 400 ... Canister, 420 ... Atmospheric communication path, 430 ... Purge piping, 440 ... Purge control Valve, 600 ... motor generator, 700 ... oiling time memory timer

Claims (4)

A canister capable of adsorbing evaporated fuel generated in a fuel tank for storing fuel of an internal combustion engine;
An evaporative fuel passage for communicating the fuel tank and the canister;
A blocking valve which is an electromagnetic valve provided in the evaporated fuel passage and capable of opening and closing the evaporated fuel passage;
A specifying means for specifying the pressure in the fuel tank;
When the specific pressure specified by the specifying means is equal to or higher than a predetermined reference pressure, the pressure in the fuel tank is reduced to a predetermined target pressure and from the fuel tank to the canister per unit time. A closing valve control means for controlling the opening and closing of the closing valve based on at least the specific pressure so that the inflow amount of the evaporated fuel flowing into the canister does not exceed an instantaneous adsorbable amount that can be adsorbed per unit time of the canister. An evaporative fuel processing apparatus comprising:   The evaporative fuel processing device according to claim 1, wherein the blockade valve control unit controls the opening and closing of the blockade valve so that the blockade valve is intermittently opened. A purge passage communicating the intake passage of the internal combustion engine and the canister;
A purge control valve provided in the purge passage and capable of opening and closing the purge passage;
The adsorption amount of the evaporated fuel adsorbed to the canister is calculated for each valve opening period in which the block valve is intermittently opened by the block valve control means, and the adsorption for each calculated valve opening period. Calculating means for calculating a total adsorption amount of the evaporated fuel adsorbed on the canister by integrating the amount;
When the total adsorption amount calculated by the calculation means reaches a predetermined adsorption limit amount, the internal combustion engine is controlled so that the internal combustion engine is started, and the purge control valve is opened. The evaporative fuel processing apparatus according to claim 2, further comprising: purge control means for controlling the purge control valve.   The evaporative fuel processing device according to claim 2 or 3, wherein the blocking valve control means changes a valve opening period in which the blocking valve is opened intermittently according to a fuel property of the fuel in the fuel tank. .

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