JP5744674B2 - Fuel supply device - Google Patents

Description

  The present invention relates to a technique for supplying fuel to an internal combustion engine.

  There has been proposed a method of selectively supplying each of a high-octane fuel and a low-octane fuel separated from a raw fuel to an internal combustion engine (see Patent Documents 1 and 2).

  In addition, a technique for preventing air from entering a high-octane fuel storage tank due to low volatility of high-octane fuel compared to raw fuel has been proposed (see Patent Document 3). Specifically, the apparatus is configured such that the evaporated fuel is supplied from the raw fuel tank to the high octane fuel tank and further supplied from the high octane fuel tank to the charcoal canister.

JP 2007-278298 A JP 2009-144720 A JP 2009-203909 A

  However, as the adsorption capacity of the canister increases, a larger amount of evaporated fuel can be used more effectively for the operation of the internal combustion engine, but the capacity is limited due to the limitation of the canister mounting space in the vehicle. For this reason, when a large amount of evaporated fuel is generated, the evaporated fuel that cannot be adsorbed by the canister is discharged outside the vehicle and is wasted.

  Accordingly, an object of the present invention is to provide an apparatus that can supply fuel to an internal combustion engine while improving the utilization rate of evaporated fuel.

  The present invention provides a first fuel that is separated from a raw fuel and contains a higher octane number component than the raw fuel, and a second fuel that contains a lower octane number component than the raw fuel, or The present invention relates to an apparatus for supplying the raw fuel to an internal combustion engine selectively or simultaneously at a specified mixing ratio.

  The fuel supply apparatus of the present invention is configured to separate a raw fuel tank that stores the raw fuel, and the raw fuel supplied from the raw fuel tank into the first fuel and the second fuel. A separator; a condenser configured to condense and store the first fuel separated by the separator; and a structure configured to store the first fuel condensed by the condenser. A first fuel tank, a canister configured to adsorb evaporated fuel generated by evaporation of the first fuel, desorb the evaporated fuel and supply the evaporated fuel to the internal combustion engine, and the condenser A vacuum pump configured to suck the evaporated fuel and supply the sucked evaporated fuel to the canister; and the vacuum pump so that the vacuum pump repeats intermittent operation Characterized in that a control device for controlling the operation.

  According to the fuel supply apparatus of the present invention, the raw fuel is separated into the first fuel (high octane fuel) and the second fuel (low octane fuel) by the separator. The first fuel is supplied from the separator to the condenser in a gas phase state, and becomes a liquid phase state by being at least partially condensed in the condenser.

  Further, the evaporated fuel derived from the first fuel is sucked from the condenser by the operation of the vacuum pump, supplied to the canister, and adsorbed by the canister (more precisely, the adsorbent incorporated therein). The evaporated fuel can be desorbed from the canister and supplied to the internal combustion engine.

  Here, since the operation is controlled so that the vacuum pump repeats intermittent operation, the supply amount of the evaporated fuel to the canister is excessive, unlike the case where the vacuum pump is operating constantly or continuously. Can be avoided or suppressed. As a result, the amount of evaporated fuel that is discharged from the canister to the outside of the vehicle and the like without being supplied to the internal combustion engine is reduced, so that the utilization rate is improved.

  The fuel supply device of the present invention further includes a plurality of open / close mechanisms that open and close the condenser and the outside, and the control device includes a closed state in which the condenser is shut off from the outside, and the condenser is externally provided. The operation of each of the plurality of opening and closing mechanisms is controlled so that the open state communicating with each other is realized alternately, and the vacuum pump is operated in the closed state of the condenser, while the operation in the open state of the condenser The operation of the vacuum pump is controlled so as to stop the operation of the vacuum pump.

  According to the fuel supply apparatus having the above configuration, when the vacuum pump operates in the closed state of the condenser, the condenser is depressurized and the evaporated fuel derived from the first fuel is supplied to the canister. On the other hand, in the open state of the condenser, the raw fuel can be separated into the first fuel and the second fuel by the separator, or the first fuel can be supplied from the condenser to the first fuel tank.

  When the operation of the vacuum pump is stopped in the open state of the condenser, a situation in which the evaporated fuel derived from the first fuel is excessively supplied to the canister can be avoided. As a result, the amount of evaporated fuel that is discharged from the canister to the outside of the vehicle without being supplied to the internal combustion engine is reduced, so that the utilization rate is improved.

The fuel supply device of the present invention includes a first opening / closing mechanism that opens and closes a primary recovery path for supplying the first fuel from the separator to the condenser, and the condenser to the first fuel tank. On the other hand, a second opening / closing mechanism for opening / closing a secondary recovery path for supplying the first fuel, and a third opening / closing mechanism for opening / closing a path for supplying air or evaporated fuel from the outside to the condenser. The control device further comprises: a primary state as a closed state of the condenser in which the first opening / closing mechanism, the second opening / closing mechanism, and the third opening / closing mechanism are closed; and the first opening / closing mechanism is opened. On the other hand, the secondary state as the open state of the condenser in which the second opening and closing mechanism and the third opening and closing mechanism are closed, and the second opening and closing mechanism and the second state in which the first opening and closing mechanism is closed Opening of the condenser with the third opening / closing mechanism open It said first opening and closing mechanism so 3 and order state is implemented in the order as, and controlling the operation of said second opening and closing mechanism and the third opening and closing mechanism.

  According to the fuel supply apparatus having such a configuration, in the primary state, the condenser is decompressed by the operation of the vacuum pump to be in a negative pressure state, and the evaporated fuel derived from the first fuel is supplied to the canister. Subsequently, in the secondary state, the raw fuel is separated into the first fuel and the second fuel by the separator. Further, in the tertiary state, the first fuel is supplied from the condenser to the first fuel tank.

  The operation of the vacuum pump is stopped in each of the secondary state and the tertiary state. Thereby, the situation where the evaporative fuel derived from the first fuel is excessively supplied to the canister can be avoided. As a result, the amount of evaporated fuel that is discharged from the canister to the outside of the vehicle without being supplied to the internal combustion engine is reduced, so that the utilization rate is improved.

  The fuel supply device according to the present invention is configured such that the evaporated fuel is supplied from the canister to the condenser through the third opening / closing mechanism in an open state.

  According to the fuel supply apparatus having such a configuration, at least a part of the evaporated fuel derived from the first fuel stored in the canister can be supplied to the condenser and can be supplied to the first fuel tank after being condensed. As a result, when the third opening / closing mechanism transitions from the closed state to the open state, it is possible to avoid a situation where the evaporated fuel present in the condenser is unnecessarily discharged to the outside of the vehicle and the like. Furthermore, the utilization rate of the evaporated fuel supplied from the first fuel tank to the canister is improved.

  The fuel supply apparatus according to the present invention is configured such that the evaporated fuel is supplied from the first fuel tank to the canister.

  According to the fuel supply apparatus having the above configuration, the evaporated fuel derived from the first fuel filling the first fuel tank can be supplied to the internal combustion engine after being supplied to the canister. The utilization rate is improved.

  The fuel supply device of the present invention further comprises a pressure sensor for measuring the internal pressure of the condenser, and the control device reduces the internal pressure of the condenser represented by the output signal of the pressure sensor, While the transition from the primary state to the secondary state is realized on the condition that the first negative pressure or less, the internal pressure of the condenser represented by the output signal of the pressure sensor is increased, The first opening / closing mechanism, the second opening / closing mechanism, and the transition from the secondary state to the tertiary state on the condition that the second negative pressure is higher than the first negative pressure. It is configured to control the operation of the third opening / closing mechanism.

  According to the fuel supply apparatus of the said structure, according to the pressure of the condenser measured using a pressure sensor, opening / closing of each opening-closing mechanism and operation | movement of a vacuum pump are controlled. Accordingly, the operation period of the vacuum pump can be appropriately controlled from the viewpoint of promoting the separation of the first fuel and the second fuel by the separator while avoiding the waste of the evaporated fuel.

  The fuel supply apparatus according to the present invention is configured such that the evaporated fuel desorbed from the canister is supplied to the separator.

  According to the fuel supply apparatus having the above configuration, the evaporated fuel discharged from the canister to the outside of the vehicle without being supplied to the internal combustion engine is reduced, and the utilization rate is improved.

  The fuel supply apparatus of the present invention is configured such that the canister is heated by the heat of condensation of the first fuel generated in the condenser.

  According to the fuel supply apparatus having such a configuration, the canister can be heated to promote the desorption of the evaporated fuel from the canister and be supplied to the internal combustion engine, so that the utilization rate of the evaporated fuel can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The structure explanatory drawing of the fuel supply apparatus as one Embodiment of this invention. The flowchart showing the procedure of a negative pressure control process. Explanatory drawing regarding supply of the fuel accompanying a negative pressure control process, and evaporative fuel. The comparison explanatory view about the recovery rate of separated fuel.

(Constitution)
The fuel supply device shown in FIG. 1 includes a raw fuel tank 10, a separator 20, a condenser 30, a first fuel tank 40, a canister 50, and an ECU (electronic control unit (control device)) 70. And. The fuel supply device is mounted on the vehicle, and is configured to supply fuel to the internal combustion engine 60 that is also mounted on the vehicle.

  In the raw fuel tank 10, normal or commercially available gasoline supplied through the fuel filler is stored as the raw fuel F0. The raw fuel F0 stored in the raw fuel tank 10 is boosted to a specified pressure by the high pressure supply pump 12 and then supplied to the internal combustion engine 60.

  The raw fuel F0 is boosted to a specified pressure by the high-pressure supply pump 12, heated by the heater 16, and then sent to the separator 20. When the raw fuel tank 10 and the heater 16 are shut off by the three-way valve 14, the raw fuel F0 is returned to the raw fuel tank 10 via the radiator 26 without passing through the separator 20. The heater 16 includes a heat exchanger that exchanges heat between the cooling water of the internal combustion engine 60 and the raw fuel. The heater 16 may be constituted by an electric heater instead of or in addition to this.

  When the raw fuel F0 stored in the raw fuel tank 10 evaporates, an evaporated fuel V containing hydrocarbons and ethanol is generated. The evaporated fuel V is supplied from the raw fuel tank 10 to the canister 50.

  The separator 20 is configured to separate the raw fuel F0 into a first fuel F1 and a second fuel F2 according to a pervaporation method (PV (pervaporation)). The separator 20 includes a separation membrane 21 that selectively permeates a high-octane component in raw fuel (gasoline), and a high-pressure chamber 22 and a low-pressure chamber 24 that are separated by the separation membrane 21 (not shown). .

  The first fuel F1 is a high-octane fuel having a higher content of high-octane components than the raw fuel F0, and is, for example, an alcohol such as ethanol. The second fuel F2 is a low-octane fuel having a lower content of high-octane components than the raw fuel F0.

  Specifically, the high-pressure and high-pressure raw fuel F0 is supplied to the high-pressure chamber 22 of the separator 20, while the low-pressure chamber 24 is maintained in a negative pressure state, thereby being contained in the raw fuel F0. The high octane component permeates the separation membrane 21 and leaches into the low pressure chamber 24. When the amount of the high octane number component of the raw fuel F0 increases, the octane number of the permeate fluid increases. Therefore, the first fuel F1 containing a large amount of high octane number components from the low pressure side of the separation membrane 21 and having a higher octane number than the raw fuel F0 is recovered. Can be done.

  On the other hand, since the amount of high octane number component contained in the raw fuel F0 flowing through the high pressure chamber 22 decreases as it goes downstream, the second fuel F2 having a low high octane number component content and a lower octane number than the raw fuel F0 is the high pressure chamber 22. Remain in. The second fuel F2 flowing out from the separator 20 is cooled in the radiator 26 and then supplied to the raw fuel tank 10.

  Further, the operating conditions of the separator 20 such as the temperature of the separation membrane 21, the temperature and supply amount of the raw fuel F0, the pressure of the high pressure chamber 22, and the pressure (negative pressure) of the low pressure chamber 24 are controlled. As a result, the separation speed or the recovery amount of the first fuel F1 and the second fuel F2 by the separator 20 changes.

  For example, the temperature of the separation membrane 21 can be adjusted by controlling the temperature of the raw fuel F0 supplied to the separator 20 by the heater 16. Further, the pressure of the high pressure chamber 22 can be adjusted by pressurizing the raw fuel F0 by the operation of the high pressure supply pump 12. Furthermore, the pressure in the low-pressure chamber 24 can be adjusted by the pressure reduction of the condenser 30 by the operation of the vacuum pump 36.

  Note that the second fuel F2 may be supplied to a second fuel tank (not shown) separate from the raw fuel tank 10 and stored in the second fuel tank. Further, the second fuel F2 stored in the second fuel tank may be supplied to the internal combustion engine 60 instead of the raw fuel F0.

  The condenser 30 is provided in the middle of a recovery path connecting the low pressure chamber 24 of the separator 20 and the first fuel tank 40, and is configured to condense the first fuel F1. The condenser 30 is configured by, for example, an air-cooled or water-cooled tank or reservoir.

  The condenser 30 is connected to the suction side of a vacuum pump (negative pressure pump) 36. The inside of the condenser 30 is controlled to a negative pressure state by the operation of the vacuum pump 36, and can be in a lower pressure state than the vapor pressure of the first fuel F1. The evaporated fuel V containing alcohol such as ethanol, which is generated by the evaporation of the first fuel F1, is supplied to the canister 50 and the like by the operation of the vacuum pump 36. The condenser 30 is provided with a pressure sensor (not shown) for measuring the internal pressure.

  A primary recovery path that connects the separator 20 and the condenser 30 is provided with a first opening / closing mechanism 31 that opens and closes the path. When the first opening / closing mechanism 31 is opened, the low pressure chamber 24 of the separator 20 and the condenser 30 are communicated with each other, and when the first opening / closing mechanism 31 is closed, the separator 20 and the condenser 30 are shut off. .

  A secondary recovery path that connects the condenser 30 and the first fuel tank 40 is provided with a second opening / closing mechanism 32 that opens and closes the path. When the second opening / closing mechanism 32 is opened, the condenser 30 and the first fuel tank 40 are communicated with each other, and when the second opening / closing mechanism 32 is closed, the condenser 30 and the first fuel tank 40 are shut off. .

  The condenser 30 and an air source canister 50 are connected, and a third opening / closing mechanism 33 is provided in the connection path. By opening the third opening / closing mechanism 33, the evaporated fuel V adsorbed by the canister 50 is introduced into the condenser 30. In addition, the path | route which connects the condenser 30 and external air is provided, the 3rd opening / closing mechanism 33 is provided in the said path | route, and it comprises so that external air may be introduce | transduced into a condenser by opening the 3rd opening / closing mechanism 33. May be. Further, a path connecting the condenser 30 and the first fuel tank 40 is provided separately from the secondary recovery path, and the third opening / closing mechanism 33 is provided in the path, and the third opening / closing mechanism 33 is opened. The vaporized fuel V may be introduced into the condenser.

  Each of the opening / closing mechanisms 31 to 33 is configured by, for example, an electromagnetic valve.

  The first fuel tank 40 stores the first fuel F1 separated from the raw fuel F0 by the separator 20. The first fuel F1 stored in the first fuel tank 40 is supplied to the internal combustion engine 60 after being boosted to a specified pressure by the high pressure supply pump 42.

  When the first fuel F1 stored in the first fuel tank 40 evaporates, an evaporated fuel V containing alcohol such as ethanol is generated. The first fuel tank 40 and the canister 50 are connected, and the evaporated fuel V is supplied from the first fuel tank 40 to the canister 50 through the connection path. The raw fuel tank 10 and the first fuel tank 40 may be connected so as to be able to supply the evaporated fuel V from one to the other, or may be connected so as to be able to supply the evaporated fuel V to each other.

  The canister 50 contains an adsorbent such as activated carbon, and in addition to the alcohol contained in the evaporated fuel V, hydrocarbons are adsorbed by the adsorbent. Thereby, the evaporated fuel V can be separated into alcohol and hydrocarbons and other components such as nitrogen.

  The separated air containing nitrogen or the like is discharged from the canister 50 to the outside of the vehicle. On the other hand, when the internal combustion engine 60 is operated and the intake pipe 61 is in a negative pressure state, alcohol and hydrocarbons adsorbed by the adsorbent in the canister 50 are supplied to the intake pipe 61 on the downstream side of the throttle valve 613, and It burns after being introduced into the combustion chamber. The discharge path connected to the canister 50 is provided with a flow rate adjusting valve 52 for adjusting the flow rate of the evaporated fuel V in the discharge path.

  The canister 50 may be configured to be heated by the condensation heat of the first fuel F1 generated in the condenser 30 and to maintain the temperature within a temperature range that can sufficiently exhibit the adsorption performance of the evaporated fuel V. . For example, the flow path of the medium may be configured such that the canister 50 is heated by the cooling medium of the condenser 30.

  An intake pipe 61 connected to the combustion chamber of the internal combustion engine 60 is provided with an intake valve 611, a fuel injection device 612, and a throttle valve 613. When the intake valve 611 is opened, the intake pipe 61 and the combustion chamber communicate with each other, and when the intake valve 611 is closed, the intake pipe 61 and the combustion chamber are shut off. The throttle valve 613 is configured to adjust the intake air amount of the internal combustion engine 60.

  The fuel injection device 612 is disposed between the intake valve 611 and the throttle valve 613, and is configured to selectively inject one of the raw fuel F0 and the first fuel F1 into each cylinder of the internal combustion engine 60. Has been. Note that the fuel injection device 612 may be configured to inject both the raw fuel F0 and the first fuel F1 into the respective cylinders of the internal combustion engine 60 at the same time with a specified mixture ratio. A mixed gas of air sucked into the intake pipe 61 and fuel injected from the fuel injection device 612 is introduced from the intake pipe 61 into the combustion chamber of each cylinder.

  When the second fuel tank is provided, the fuel injection device 612 selectively selects one of the first fuel F1 and the second fuel F2, or both of them at the same time with a specified mixture ratio, and each cylinder of the internal combustion engine 60. May be configured to inject.

  The evaporated fuel V sucked from the condenser 30 by the operation of the vacuum pump 36 is directly supplied from the discharge side of the vacuum pump 36 to the intake pipe 61 on the downstream side of the throttle valve 613. The evaporated fuel V may be supplied directly from the first fuel tank 40 to the intake pipe 61 of the internal combustion engine 60.

  The intake pipe 61 is provided with a turbocharger 65, a venturi gas mixer 651, and a purge pump 652 on the upstream side of the throttle valve 613. The evaporated fuel V can be supplied from the canister 50 to the intake pipe 61 via the purge pump 652 and the turbocharger 65.

  The internal combustion engine 60 may be a naturally aspirated engine instead of the engine with the turbocharger 65. In this case, the evaporated fuel V may be supplied from the canister 50 to the intake pipe 61 on the downstream side of the throttle valve 613 through a purge control valve (not shown).

  The control device 70 is configured by a programmable computer. The control device 70 receives output signals of various sensors for detecting various states of the fuel supply device, such as a pressure sensor that outputs a signal corresponding to the pressure P of the condenser 30. The control device 70 is programmed to execute “negative pressure control processing” to be described later. In addition to fuel injection control and ignition timing control of the internal combustion engine 60, the control device 70 adjusts the operating conditions of the separator 20, adjustment of fuel supplied to the internal combustion engine 60, operation control of each pump, and each valve. It is programmed to execute arithmetic processing necessary for opening / closing or adjusting the opening degree.

  “Programmed” means that an arithmetic processing unit such as a CPU, which is a component of a computer, reads out software in addition to necessary information from a memory or recording medium such as a ROM or a RAM, It means that it is comprised so that an arithmetic processing may be performed according to.

(function)
The function of the fuel supply apparatus having the above configuration will be described. Specifically, the “negative pressure control process” is repeatedly executed by the control device 70 according to the procedure described below.

  First, in the primary state of the condenser 30 (closed state (first opening / closing mechanism 31... Closed, second opening / closing mechanism 32... Closed, third opening / closing mechanism 33... Closed)), the operation of the vacuum pump 36 is started ( FIG. 2 / STEP002).

  As a result, as shown in FIG. 3A, the evaporated fuel V (gas) is discharged from the condenser 30 (see the arrow), and the condenser 30 is decompressed. The evaporated fuel V is supplied to the canister 50 and the like.

  It is determined whether or not the pressure P of the condenser 30 has reached the first negative pressure P1 or less (FIG. 2 / STEP004). “Negative pressure” is defined as a negative value based on atmospheric pressure or normal pressure. That is, the absolute value increases as the pressure is lower than the atmospheric pressure.

  When the determination result is affirmative (FIG. 2 / STEP004... YES), the operation of the vacuum pump 36 is stopped and the first opening / closing mechanism 31 is opened (FIG. 2 / STEP006).

  Note that the operation of the vacuum pump 36 may be stopped and the first opening / closing mechanism 31 may be opened after the first designated time has elapsed since the operation start of the vacuum pump 36 (see FIG. 2 / STEP002) (see FIG. 2 / STEP006). .

  As a result, the first opening / closing mechanism 31 is opened while the second opening / closing mechanism 32 and the third opening / closing mechanism 33 are closed (hereinafter referred to as “secondary state”). Separation of the fuel F1 and the second fuel F2 is started. As shown in FIG. 3B, the first fuel F <b> 1 is supplied from the separator 20 to the condenser 30. At least a part of the first fuel F1 is stored after being condensed (phase transition from the gas phase to the liquid phase) in the condenser 30 in a negative pressure and cooled state. Further, when the vacuum pump 36 is stopped, the evaporated fuel V increases in the condenser 30 and the condenser 30 is pressurized.

  It is determined whether or not the pressure P of the condenser 30 has reached a second negative pressure P2 higher than the first negative pressure P1 (FIG. 2 / STEP008). As described above, “negative pressure” is defined as a negative value with reference to the atmospheric pressure, so the absolute value of the second negative pressure P2 is smaller than the absolute value of the first negative pressure P1.

  When the determination result is affirmative (FIG. 2 / STEP008... YES), the first opening / closing mechanism 31 is closed while the second opening / closing mechanism 32 and the third opening / closing mechanism 33 are opened (FIG. 2 / STEP010). .

  In addition, after the operation of the vacuum pump 36 is stopped and the first opening / closing mechanism 31 is opened, the second opening / closing mechanism 32 and the third opening / closing mechanism are closed while the first opening / closing mechanism 31 is closed after the second designated time has elapsed. 33 may be opened (see FIG. 2 / STEP010).

  Each value of the first negative pressure P1 and the second negative pressure P2 may be changed in advance to various values, and depending on the running state (acceleration request, etc.) of the fuel supply device or the vehicle in which it is mounted, It may be changed by the control device 70. For example, the concentration or content of the first fuel F1 of the raw fuel F0 stored in the raw fuel tank 10 may be measured, and the second negative pressure P2 may be increased as the measured value is higher.

  When the first opening / closing mechanism 31 is closed, the separation of the first fuel F1 and the second fuel F2 by the separator 20 is stopped. By opening the second opening / closing mechanism 32, the first fuel F1 stored in the condenser 30 is supplied to the first fuel tank 40 as shown in FIG. As the third opening / closing mechanism 33 is opened, the evaporated fuel V is supplied from the canister 50 to the condenser 30 as shown in FIG. 3C, and the condenser 30 is pressurized to the same pressure as the first fuel tank 40. become.

  A specified time (for example, 10) is realized after the state in which the first opening / closing mechanism 31 is closed and the second opening / closing mechanism 32 and the third opening / closing mechanism 33 are opened (hereinafter referred to as “tertiary state”). It is determined whether [s]) has elapsed (FIG. 2 / STEP012). When the determination result is affirmative (FIG. 2 / STEP012... YES), both the second opening / closing mechanism 32 and the third opening / closing mechanism 33 are closed (FIG. 2 / STEP014). Thereby, after the primary state is realized again, the processing after the start of the operation of the vacuum pump 36 is repeated again (see FIG. 2 / STEP002).

(Function and effect)
According to the fuel supply device of the present invention, when the vacuum pump 36 operates in the primary state, the evaporated fuel V derived from the first fuel F1 is supplied to the canister 50 (FIG. 2 / STEP002, FIG. 3A). reference). The evaporated fuel V is adsorbed by an adsorbent incorporated in the canister 50, desorbed from the adsorbent, and supplied from the canister 50 to the internal combustion engine 60.

  After that, when the secondary state is realized, the condenser 30 and the low pressure chamber 24 of the separator 20 communicating with the condenser 30 are in a negative pressure state. Therefore, the raw fuel F0 supplied from the raw fuel tank 10 to the high pressure chamber 22 of the separator 20 is separated into the first fuel F1 and the second fuel F2 according to the PV method (FIG. 2 / STEP006, FIG. 3 (b)). The first fuel F <b> 1 is supplied from the separator 20 to the condenser 30 in a gas phase state, and is at least partially condensed in the condenser 30 to be in a liquid phase state and stored in the condenser 30.

  Further, in the tertiary state, the first fuel F1 is supplied from the condenser 30 to the first fuel tank 40 (see FIG. 2 / STEP010, FIG. 3C).

  In the secondary state (see FIG. 3B) and the tertiary state (see FIG. 3C), the operation of the vacuum pump 36 is stopped.

  Thus, since the operation of the vacuum pump 36 is controlled so as to repeat intermittent operation, unlike the case where the vacuum pump 36 is operating steadily or continuously, the evaporated fuel V with respect to the canister 50 is supplied. An excessive supply amount can be avoided or suppressed. As a result, the amount of the evaporated fuel V that is not supplied to the internal combustion engine 60 and cannot be recovered from the canister 50 and discharged to the outside of the vehicle or the like is reduced, and the utilization rate is improved.

  Further, the evaporated fuel V is supplied from the canister 50 to the condenser 30 through the open third opening / closing mechanism 33 (see FIG. 3C). Thereby, when the 3rd opening-and-closing mechanism 33 changes from a closed state to an open state, the situation where the evaporated fuel V which exists in the condenser 30 is discharged | emitted wastefully outside the vehicle is avoided. Further, the utilization rate of the evaporated fuel V supplied from the first fuel tank 40 to the canister 50 can be improved.

  The evaporated fuel V desorbed from the canister 50 is supplied to the low pressure chamber 24 of the separator 20 (see FIG. 1). For this reason, in FIG.3 (c), instead of making the condenser 30 and the 1st fuel tank 40 into the same pressure, the operation | movement which makes the condenser 30 the same pressure from the low pressure chamber 24 of the separator 20 makes low pressure The droplets of the first fuel F1 after separation in the chamber 24 can be discharged to the first fuel tank 40, and the performance of the separator 20 can be improved.

  Further, the canister 50 is heated by the condensation heat of the first fuel F <b> 1 generated in the condenser 30. Due to the heating, it is possible to promote the desorption of the evaporated fuel V from the canister 50 and supply it to the internal combustion engine 60. Therefore, the utilization rate of the evaporated fuel V can be improved.

  In FIG. 4, the recovery rate of the first fuel F1 (for example, ethanol) is compared between the example of the present invention and the comparative example. The “recovery rate” corresponds to the “utilization rate”, and is a loss due to the discharge of the first fuel F1 from the reduction amount to the outside air or the like with respect to the reduction amount of the first fuel F1 contained in the raw fuel F0. It means the ratio of the quantity minus the quantity.

  The first and second embodiments are the result of repeated negative pressure control. The comparative example is a result of continuously moving the vacuum pump without stopping. In the first embodiment, the difference between the first negative pressure P1 and the second negative pressure P2 is set larger than that in the second embodiment, and the negative pressure control cycle is relatively long according to this.

  As is apparent from FIG. 4, the recovery rate of the first fuel F1 in the first and second embodiments is higher than that in the comparative example. This means that the loss of the evaporated fuel V derived from the first fuel F1 is small by the execution of the negative pressure control, and the first fuel F1 is efficiently recovered. Further, the recovery rate of the first fuel F1 in the first embodiment is higher than that in the second embodiment. This means that the loss of the evaporated fuel V derived from the first fuel F1 is reduced and the recovery rate of the first fuel F1 is further improved by changing the negative pressure control cycle.

(Other embodiments of the present invention)
In the above-described embodiment, the primary state (vacuum pump operation), the secondary state (vacuum pump operation stop), and the tertiary state (vacuum pump operation stop) are sequentially repeated for each negative pressure control period (FIG. 2). And FIG. 3). As another embodiment, after the primary state and the secondary state are alternately realized a plurality of times for each negative pressure control period, the tertiary state may be realized.

  The evaporated fuel V may be supplied from the first fuel tank 40 to the condenser 30 through the secondary recovery path when the third opening / closing mechanism 33 is omitted and the second opening / closing mechanism 32 is in the open state. Thus, the pressure of the condenser 30 can be increased through the common path, and the first fuel F1 can be supplied from the condenser 30 to the first fuel tank 40.

  In this case, the controller 70 continuously repeats the state in which the first opening / closing mechanism 31 and the second opening / closing mechanism 32 are closed and the state in which one of the first opening / closing mechanism 31 and the second opening / closing mechanism 32 is open. May be realized. The vacuum pump 36 is operated when the first opening / closing mechanism 31 and the second opening / closing mechanism 32 are closed, while the vacuum pump 36 is operated when one of the first opening / closing mechanism 31 and the second opening / closing mechanism 32 is open. The operation may be stopped.

  According to the fuel supply apparatus having the above configuration, the vacuum pump 36 operates in a state where the first opening / closing mechanism 31 and the second opening / closing mechanism 32 are closed, whereby the condenser 30 is brought into a negative pressure state and the first The evaporated fuel V derived from the fuel F1 is supplied to the canister (see FIG. 3A).

  Thereafter, the raw fuel F0 is separated into the first fuel F1 and the second fuel F2 by the separator 20 with the first opening / closing mechanism 31 open and the second opening / closing mechanism 32 closed (FIG. 3 ( b)). Alternatively, after the first opening / closing mechanism 31 is closed and the second opening / closing mechanism 32 is opened, the first fuel F1 is supplied from the condenser 30 to the first fuel tank 40, while evaporating. The fuel V is supplied from the first fuel tank 40 to the condenser 30 (see FIG. 3C).

  At this time, the operation of the vacuum pump 36 is stopped, so that the situation where the evaporated fuel V is excessively supplied to the canister 50 can be avoided. As a result, the evaporated fuel V discharged from the canister 50 to the outside of the vehicle without being supplied to the internal combustion engine 60 is reduced, and the utilization rate is improved.

DESCRIPTION OF SYMBOLS 10 ... Raw fuel tank, 20 ... Separator, 21 ... Separation membrane, 30 ... Condenser, 31 ... First opening / closing mechanism, 32 ... Second opening / closing mechanism, 33 ... Third opening / closing mechanism, 36 ... Vacuum pump, 40 ... No. 1 fuel tank, 50 ... canister, 60 ... internal combustion engine, 70 ... ECU (control device).

Claims (8)

A first fuel that is separated from the raw fuel and contains a higher octane component than the raw fuel; and a second fuel or a raw fuel that contains a lower octane component than the raw fuel. For the internal combustion engine, either selectively or at a specified mixing ratio,
A raw fuel tank for storing the raw fuel;
A separator configured to separate the raw fuel supplied from the raw fuel tank into the first fuel and the second fuel;
A condenser configured to condense the first fuel separated by the separator;
A first fuel tank configured to store the first fuel condensed by the condenser;
A canister configured to adsorb evaporated fuel generated by evaporation of the first fuel, desorb the evaporated fuel, and supply the evaporated fuel to the internal combustion engine;
A vacuum pump configured to suck the evaporated fuel from the condenser and supply the sucked evaporated fuel to the canister;
A fuel supply device comprising: a control device that controls the operation of the vacuum pump so that the vacuum pump repeats intermittent operation. The fuel supply device according to claim 1, wherein
A plurality of opening and closing mechanisms for opening and closing the condenser and the outside;
The control device controls each operation of the plurality of opening / closing mechanisms so that a closed state where the condenser is blocked from outside and an open state where the condenser communicates with the outside are alternately realized. And a fuel supply device that controls the operation of the vacuum pump so as to stop the operation of the vacuum pump in the open state of the condenser while operating the vacuum pump in the closed state of the condenser. . The fuel supply device according to claim 2, wherein
A first opening / closing mechanism for opening / closing a primary recovery path for supplying the first fuel from the separator to the condenser;
A second opening / closing mechanism for opening / closing a secondary recovery path for supplying the first fuel from the condenser to the first fuel tank;
A third opening / closing mechanism for opening / closing a path for supplying air or evaporated fuel from the outside to the condenser;
The control device includes a primary state as a closed state of the condenser in which the first opening / closing mechanism, the second opening / closing mechanism, and the third opening / closing mechanism are closed, and the first opening / closing mechanism is open, The secondary state as the open state of the condenser in which the second opening and closing mechanism and the third opening and closing mechanism are closed, and the second opening and closing mechanism and the third opening and closing mechanism while the first opening and closing mechanism is closed The operation of the first opening / closing mechanism, the second opening / closing mechanism, and the third opening / closing mechanism is controlled so that the third state as the open state of the condenser that is open is sequentially realized. Fuel supply device. The fuel supply device according to claim 3, wherein
The fuel supply device, wherein the evaporated fuel is supplied from the canister to the condenser through the third opening / closing mechanism in an open state. The fuel supply device according to claim 4, wherein
The fuel supply device, wherein the evaporated fuel is configured to be supplied from the first fuel tank to the canister. The fuel supply device according to claim 3, wherein
A pressure sensor for measuring the internal pressure of the condenser;
The control device makes a transition from the primary state to the secondary state on the condition that the internal pressure of the condenser represented by the output signal of the pressure sensor has decreased to become the first negative pressure or less. On the other hand, the internal pressure of the condenser, represented by the output signal of the pressure sensor, has increased from the secondary state as a requirement that it has become a second negative pressure higher than the first negative pressure. A fuel supply device configured to control operations of the first opening / closing mechanism, the second opening / closing mechanism, and the third opening / closing mechanism so as to realize a transition to a tertiary state. In the fuel supply device according to any one of claims 1 to 6,
A fuel supply apparatus, wherein the fuel vapor desorbed from the canister is supplied to the separator. In the fuel supply device according to any one of claims 1 to 7,
The fuel supply device, wherein the canister is heated by the condensation heat of the first fuel generated in the condenser.

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