JP2023157095A - fuel supply device - Google Patents

Abstract

To more appropriately determine whether high-concentration vapor is generated in a fuel tank or not.SOLUTION: A fuel supply device includes a fuel tank for storing fuel, a fuel pump for supplying the fuel in the fuel tank into a fuel passage, and a control device which uses feedback control using a proportional term and an integration term on the basis of a difference between fuel pressure as pressure of fuel and a target fuel pressure to control the fuel pump. The control device determines that high-concentration vapor is generated in the fuel tank when a state in which the integration term is equal to or higher than a prescribed value continues for a prescribed time or longer. Accordingly, it is possible to more appropriately determine whether the high-concentration vapor is generated in the fuel tank or not.SELECTED DRAWING: Figure 2

Description

The present invention relates to a fuel supply device, and more particularly to a fuel supply device including a fuel tank and a fuel pump.

BACKGROUND ART Conventionally, as this type of fuel supply device, one including a fuel tank, a fuel pump, and a surge tank has been proposed (see, for example, Patent Document 1). The fuel tank stores fuel. The fuel pump supplies fuel to the fuel passage (fuel pipe). The surge tank temporarily stores vapor generated within the fuel tank. With this device, when the fuel supply device is located at a predetermined altitude or higher, the fuel temperature in the fuel tank is above the predetermined temperature, and the pressure in the surge tank is below the predetermined pressure, It has been determined that a high concentration of vapor is being generated.

Special Publication No. 6-31576

However, in fuel supply systems that are not equipped with a temperature sensor that directly detects the fuel temperature in the fuel tank, the above method cannot be used, and it is not possible to use the above method. This causes the inconvenience that it cannot be determined. In order to eliminate these inconveniences, a method can be considered in which, instead of fuel temperature, another physical quantity correlated with fuel temperature is used to determine whether or not a high concentration of vapor is occurring within the fuel tank. However, with this method, if the predicted correlation between fuel temperature and other physical quantities deviates from the actual correlation for some reason, it is difficult to accurately determine whether a high concentration of vapor is occurring in the fuel tank. It becomes impossible to judge.

The main purpose of the fuel supply device of the present invention is to more appropriately determine whether or not high-concentration vapor is generated within a fuel tank.

The fuel supply device of the present invention employs the following means to achieve the above-mentioned main purpose.

The fuel supply device of the present invention includes:
a fuel tank for storing fuel;
a fuel pump that supplies the fuel in the fuel tank to a fuel passage;
a control device that controls the fuel pump using feedback control using a proportional term and an integral term based on the difference between the fuel pressure as the pressure of the fuel and the target fuel pressure;
A fuel supply device comprising:
The gist of the control device is to determine that high-concentration vapor has occurred in the fuel tank when a state in which the integral term is equal to or greater than a predetermined value continues for a predetermined time or more.

In the fuel supply system of the present invention, the fuel pump is controlled using feedback control using a proportional term and an integral term based on the difference between the fuel pressure as the fuel pressure and the target fuel pressure. When the integral term continues to be equal to or greater than a predetermined value for a predetermined period of time or more, it is determined that high concentration vapor has occurred in the fuel tank. When a high concentration of vapor occurs in the fuel tank, a vapor lock occurs in which the fuel pressure does not rise to the target fuel pressure even though the fuel pump is being driven. At this time, since the integral term becomes large, if the integral term remains at a predetermined value or more for a predetermined period or longer, a high concentration of vapor is generated in the fuel tank, and such a vapor lock occurs. It is thought that there are. Therefore, when the integral term is greater than or equal to a predetermined value for a predetermined period or longer, it is determined that high-concentration vapor has occurred in the fuel tank. It can be determined whether or not it has occurred. Here, the "predetermined value" may be a threshold value of the integral term for determining whether or not the integral term has become large because the fuel pressure does not rise to the target fuel pressure even though the fuel pump is being driven. . The "predetermined time" is a time threshold for determining whether the state in which the integral term has exceeded a predetermined value is due to the occurrence of high concentration vapor in the fuel tank.

In such a fuel supply device of the present invention, the control device controls the control device when a predetermined condition including at least that the fuel in the fuel tank is in a predetermined state where it is easy to vaporize is satisfied, and when the predetermined condition is not satisfied. Nevertheless, when a state in which the integral term is equal to or greater than the predetermined value continues for the predetermined time or more, it may be determined that high-concentration vapor has occurred in the fuel tank. In this way, it is possible to more appropriately determine whether or not high concentration vapor is occurring within the fuel tank. Here, the "predetermined state" may be when the atmospheric pressure is low and the fuel temperature is high, for example, when the vehicle is in a high-temperature environment at a high altitude.

Further, in the fuel supply device of the present invention, when the control device determines that high concentration vapor has occurred in the fuel tank, the control device determines that the target fuel pressure is determined to be that high concentration vapor has occurred in the fuel tank. It may be higher than when it is not used. In this way, the vapor in the fuel pump and the fuel passage can be crushed by the fuel pressure, and vapor lock can be eliminated.

The fuel supply processing device of the present invention is the fuel supply device of the present invention in any of the above-mentioned aspects, that is, basically, a fuel tank for storing fuel and a fuel passage that supplies the fuel in the fuel tank. and a control device that controls the fuel pump using feedback control using a proportional term and an integral term based on a difference between a fuel pressure as the pressure of the fuel and a target fuel pressure. , a fuel supply device in which the control device determines that a high concentration of vapor has occurred in the fuel tank when a state in which the integral term is equal to or greater than a predetermined value continues for a predetermined time or more;
a vaporized fuel processing device having a canister connected to the fuel tank via a vapor passage; and a purge passage connecting the canister and an intake pipe of an engine;
The purpose is to have the following.

Since the fuel supply processing device of the present invention includes the fuel supply device of the present invention in any of the above-mentioned aspects, the effect of the fuel supply device of the present invention can be achieved, that is, a high concentration of vapor can be more appropriately contained in the fuel tank. This has the effect of being able to determine whether or not it has occurred.

In this case, the predetermined condition may be that a purge concentration, which is a ratio of vapor to the amount of gas supplied to the intake pipe, is equal to or higher than a predetermined concentration. In this way, it is possible to more appropriately determine whether or not high-concentration vapor is occurring within the fuel tank. Here, the "predetermined concentration" may be a purge concentration threshold value for determining whether or not high concentration vapor is generated in the fuel tank.

1 is a configuration diagram schematically showing the configuration of an automobile 10 equipped with a fuel supply processing device as an embodiment of the present invention. 7 is a flowchart showing an example of a high vapor determination routine executed by the electronic control unit 70. FIG. It is an explanatory view showing an example of area A1. 4 is an explanatory diagram for explaining line L1 in FIG. 3. FIG.

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a block diagram schematically showing the structure of an automobile 10 equipped with a fuel supply processing device as an embodiment of the present invention. As shown in the figure, the automobile 10 of the embodiment includes an engine 12, a fuel supply device 42, a vaporized fuel processing device 50, and a drive wheel 64a, which is connected to the crankshaft 14 of the engine 12 and via a differential gear 62. 64b, a starter (not shown) for starting the engine 12, and an electronic control unit 70 for controlling the entire vehicle. The fuel supply device of the embodiment mainly includes the fuel supply device 42 and the electronic control unit 70.

The engine 12 is configured as an internal combustion engine that uses fuel such as gasoline or diesel oil from the fuel tank 40 to output power through four strokes: intake, compression, expansion, and exhaust. This engine 12 sucks air purified by an air cleaner 22 into an intake pipe 23, passes it through a throttle valve 24, and injects fuel from a fuel injection valve 26 on the downstream side of the throttle valve 24 in the intake pipe 23. and fuel. Then, this air-fuel mixture is sucked into the combustion chamber 29 through the intake valve 28 and exploded and combusted by electric sparks from the ignition plug 30. The reciprocating motion of the piston 32, which is pushed down by the energy of the explosive combustion, is converted into the rotational motion of the crankshaft 14. Convert. Exhaust gas discharged from the combustion chamber 29 to the exhaust pipe 34 via the exhaust valve 33 is discharged to the outside air via the purification device 35. The purification device 35 includes a catalyst (three-way catalyst) 35a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

The fuel supply device 42 is configured to be able to supply the fuel in the fuel tank 40 to the fuel injection valve 26. This fuel supply device 42 includes a fuel passage 43, a fuel pump 44, a relief passage 45, and a relief valve 46. The fuel passage 43 is connected to the fuel injection valve 26. The fuel pump 44 supplies fuel in the fuel tank 40 to the fuel passage 43.

The relief passage 45 is connected to the fuel passage 43 and the fuel tank 40. The relief valve 46 is provided in the relief passage 45 and closes when the pressure of the fuel in the fuel passage 43 (fuel pressure Pf) is less than the valve opening pressure Pfrv of the relief valve 46. The valve opens when is equal to or higher than the valve opening pressure Pfrv. When the relief valve 46 opens, a portion of the fuel in the fuel passage 43 is returned to the fuel tank 40 via the relief passage 45. In this way, the pressure of the fuel in the fuel passage 43 is suppressed from becoming excessive.

The vaporized fuel processing device 50 is configured to be able to perform purge that supplies vaporized fuel gas (purge gas) containing vaporized fuel generated within the fuel tank 40 to the intake pipe 23 . This vaporized fuel processing device 50 includes an introduction passage (vapor passage) 51, a blocking valve 52, a canister 53, a purge passage 55, and a purge valve 56.

The introduction passage (vapor passage) 51 is connected to the fuel tank 40 and the canister 53. The blocking valve 52 is provided in the introduction passage (vapor passage) 51 and is configured as a normally closed type electromagnetic valve.

The blockage valve 52 is a flow rate regulating valve, and when the valve is closed, it blocks the introduction passage (vapor passage) 51 to cut off communication between the fuel tank 40 and the canister 53, and when the valve is open, it closes the introduction passage (vapor passage) 51. The flow rate of gas flowing through 51 is adjusted. The blocking valve 52 includes a valve seat (not shown) formed in the casing, a valve body (not shown) disposed in the casing so as to be movable in the axial direction, and a valve guide (not shown) disposed in the casing. A stepping motor 52b is connected to the valve body via a stepping motor 52b. The stepping motor 52b moves the valve body forward and backward in the axial direction with respect to the valve seat. As the stepping motor 52b operates, the valve body approaches the valve seat, and a sealing member (not shown) of the valve body comes into contact with the valve seat, thereby closing the sealing valve 52. Further, as the stepping motor 52b operates, the valve body separates from the valve seat, and a sealing member (not shown) of the valve body separates from the valve seat, thereby opening the sealing valve 52. The stepping motor 52b is controlled by an electronic control unit 70.

The canister 53 is connected to an introduction passage (vapor passage) 51 and a purge passage 55, and is open to the atmosphere via an atmosphere opening passage 54. The inside of the canister 53 is filled with an adsorbent such as activated carbon that can adsorb vapor (vaporized fuel) from the fuel tank 40 . The atmosphere opening passage 54 is provided with an air filter (not shown).

The purge passage 55 is connected to the canister 53 and the intake pipe 23 downstream of the throttle valve 24 . The purge valve 56 is provided in the purge passage 55 and is configured as a normally closed type electromagnetic valve. This purge valve 56 is controlled by an electronic control unit 70.

This vaporized fuel processing device 50 performs purging by adjusting the opening degree of the purge valve 56 when the blockage valve 52 is in the open state. Specifically, the purge gas containing vapor (vaporized fuel) generated in the fuel tank 40 is controlled to flow through an introduction passage (vapor passage) 51, a canister 53, and a purge passage 55 using the negative pressure in the intake pipe 23. is supplied to the intake pipe 23 with the adjustment of. Therefore, the engine 12 can draw a mixture of air and fuel (fuel from the fuel injection valve 26 and vapor (vaporized fuel) from the vaporized fuel processing device 50) into the combustion chamber 29.

The electronic control unit 70 is configured as a microprocessor centered on a CPU, and in addition to the CPU, includes a ROM for storing processing programs, a RAM for temporarily storing data, a flash memory for storing and retaining data, and an input. Equipped with an output port. Signals from various sensors are input to the electronic control unit 70 via input ports.

Examples of signals input to the electronic control unit 70 include a crank angle θcr from a crank position sensor 14a that detects the rotational position of the crankshaft 14 of the engine 12, and a water temperature sensor 15 that detects the temperature of the cooling water of the engine 12. The cooling water temperature Tw can be mentioned. A cam that detects the throttle opening TH from the throttle position sensor 24a that detects the opening (position) of the throttle valve 24, and the rotational position of the intake camshaft that opens and closes the intake valve 28 and the exhaust camshaft that opens and closes the exhaust valve 33. The cam angles θci and θco from the position sensor 16 can also be mentioned. The intake air amount Qa from the air flow meter 23a installed upstream of the throttle valve 24 in the intake pipe 23, the intake temperature Ta from the temperature sensor 23b installed upstream of the throttle valve 24 in the intake pipe 23, The front air-fuel ratio AF1 from the front air-fuel ratio sensor 37 installed on the upstream side of the purification device 35 in the exhaust pipe 34, and the rear air-fuel ratio sensor 38 installed on the downstream side of the purification device 35 in the exhaust pipe 34. The rear air-fuel ratio AF2 can also be mentioned. Tank internal pressure Pt, which is the pressure inside the fuel tank 40, from a pressure sensor 40a attached to the fuel tank 40, and fuel from a fuel pressure sensor 43p attached near the fuel injection valve 26 (for example, a delivery pipe) in the fuel passage 43. The fuel pressure Pf, which is the pressure of the fuel in the passage 43, and the rotation speed Np of the fuel pump 44, which is detected from the rotation speed sensor 44b attached to the fuel pump 44, can also be cited. The opening degree Osv of the shutoff valve 52 is detected by the shutoff valve position sensor 52a which detects the opening degree (position) of the blockade valve 52, and the opening degree of the purge valve 56 is detected by the purge valve position sensor 56a which detects the opening degree (position) of the purge valve 56. Opv can also be mentioned. Examples include the ignition signal IG from the ignition switch 80 and the shift position SP from the shift position sensor 82 that detects the operating position of the shift lever 81. The accelerator opening degree Acc from the accelerator pedal position sensor 84 which detects the amount of depression of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 which detects the amount of depression of the brake pedal 85, and the vehicle speed V from the vehicle speed sensor 88. , and the atmospheric pressure Pout from the atmospheric pressure sensor 89.

Various control signals are output from the electronic control unit 70 via an output port. The signals output from the electronic control unit 70 include, for example, a control signal to the throttle valve 24, a control signal to the fuel injection valve 26, a control signal to the spark plug 30, a control signal to the fuel pump 44, and a blockage valve. 52 and a control signal to purge valve 56. Further, a control signal to the transmission 60 and a control signal to a starter (not shown) can also be cited.

The electronic control unit 70 calculates the rotation speed Ne of the engine 12 based on the crank angle θcr from the crank position sensor 14a. Further, the electronic control unit 70 calculates the load factor (the air actually taken in in one cycle with respect to the stroke volume per one cycle of the engine 12) based on the intake air amount Qa from the air flow meter 23a and the rotational speed Ne of the engine 12. (volume ratio) KL is calculated.

In the automobile 10 of the embodiment configured in this manner, the electronic control unit 70 controls the operation of the engine 12 based on the required load factor KL* of the engine 12 based on the accelerator opening Acc and the vehicle speed V, and specifically controls the throttle control. It performs intake air amount control that controls the opening degree of the valve 24, fuel injection control that controls the amount of fuel injected from the fuel injection valve 26, ignition control that controls the ignition timing of the spark plug 30, and the like. Further, the electronic control unit 70 also controls the fuel pump 44 of the fuel supply device 42 and the blockade valve 52 and purge valve 56 of the vaporized fuel processing device 50.

In the operation control of the engine 12, in the intake air amount control, the electronic control unit 70 sets the target opening degree TH* of the throttle valve 24 based on the required load factor KL* of the engine 12, and sets the target opening degree TH* is used to control the throttle valve 24. In fuel injection control, the target injection amount Qf* is set by multiplying the basic fuel injection amount Qfb based on the rotation speed of the engine 12 and the intake pipe pressure by a correction coefficient based on various sensor values that detect the state of the engine 12. , the fuel injection valve 26 is controlled so that the amount of fuel injected from the fuel injection valve 26 becomes the target injection amount Qf*. In the ignition control, the electronic control unit 70 sets a target ignition timing Ti* of the ignition plug 30 based on the rotation speed Ne and the load factor KL of the engine 12, and controls the ignition plug 30 using the set target ignition timing Ti*. Control. In controlling the blockade valve 52, when the tank internal pressure Pt (gauge pressure) is below a threshold value Ptref, which is slightly higher than 0 kPa, the blockade valve 52 is controlled to be in the closed state, and when the tank internal pressure Pt is higher than the threshold value Ptref. , controls the blocking valve 52 so that it is in the open state. In controlling the purge valve 56, when the purge condition is satisfied, the purge valve 56 is controlled to be in the open state and the above-mentioned purge is executed, and when the purge condition is not satisfied, the purge valve 56 is controlled to be in the closed state. Control. As the purge condition, for example, a condition is used in which the cooling water temperature Tw is equal to or higher than a threshold value, the operation of the engine 12 is being controlled (such as fuel injection control), and the blocking valve 52 is in an open state.

In controlling the fuel pump 44, the following equation (1) is used to control the fuel pump 44 based on the difference between the fuel pressure Pf detected by the fuel pressure sensor 43p and the target fuel pressure Pf* at predetermined time intervals (for example, every few msec). The target discharge flow rate Qp* of the fuel pump 44 is repeatedly set. Then, the fuel pump 44 is controlled using the set target discharge flow rate Qp*. In equation (1), the first term is the previously set target discharge flow rate Qp*. The second term is a proportional term in feedback control of the fuel pump 44 to bring the fuel pressure Pf closer to the target fuel pressure Pf*. "Kp" is the gain of the proportional term. The third term is an integral term in feedback control of the fuel pump 44 to bring the fuel pressure Pf closer to the target fuel pressure Pf*. "Ki" is the gain of the integral term. In this way, the target discharge flow rate Qp* of the fuel pump 44 is set using feedback control using a proportional term and an integral term based on the difference between the fuel pressure Pf detected by the fuel pressure sensor 43p and the target fuel pressure Pf*, and the fuel pump 44.

Qp*=Previous Qp*+Kp・(Pf*-Pf)+Ki・∫(Pf*-Pf)dt...(1)

Next, the operation of the automobile 10 according to the embodiment configured as described above, particularly the operation when determining whether the vapor in the fuel tank 40 has a high concentration will be explained. FIG. 2 is a flowchart showing an example of a high vapor determination routine executed by the electronic control unit 70. This routine is executed at predetermined time intervals (for example, every few milliseconds) when the shutoff valve 52 and the purge valve 56 are in the open state.

When this routine is executed, the CPU of the electronic control unit 70 executes a process of inputting the intake air temperature Ta, the atmospheric pressure Pout, the front air-fuel ratio AF1, the intake air amount Qa, and the fuel injection amount Qf (step S100). As the intake air temperature Ta, a value detected by the temperature sensor 23b is input. The value detected by the atmospheric pressure sensor 89 is input as the atmospheric pressure Pout. The value detected by the front air-fuel ratio sensor 37 is input as the front air-fuel ratio AF1. As the intake air amount Qa, a value detected by the air flow meter 23a is input. The same value as the target injection amount Qf* is input as the fuel injection amount Qf.

Next, the state point Pst of the fuel in the fuel tank 40, which is composed of the intake air temperature Ta and the atmospheric pressure Pout, is set (step S110), and the purge concentration Cp is determined from the front air-fuel ratio AF1, the intake air amount Qa, and the fuel injection amount Qf. Calculate (step S120). The purge concentration Cp is calculated as the ratio of a value obtained by subtracting the fuel injection amount Qf from the volume of fuel involved in combustion estimated from the front air-fuel ratio AF1 and the intake air amount Qa to the fuel injection amount Qf.

Next, it is determined whether the state point Pst is located within a region A1 indicating that the fuel in the fuel tank 40 is in an environment where it is likely to become vapor (step S130). FIG. 3 is an explanatory diagram showing an example of area A1. FIG. 4 is an explanatory diagram for explaining the line L1 in FIG. 3. In FIG. 4, the broken line Lpv indicates the saturated vapor curve of the fuel. The region A1 is a region in which the relationship between the atmospheric pressure Pout and the intake air temperature Ta is on the lower pressure and higher temperature side than the line L1. The position of the state point Ps of the fuel in the fuel tank 40 determined from the gauge pressure (pressure) in the fuel tank 40 and the temperature (fuel temperature) of the fuel in the fuel tank 40 is on the lower pressure and higher temperature side than the saturated vapor curve (broken line Lpv). If the fuel is in the region Apv, it can be said that the environment is such that fuel tends to become vapor. In the embodiment, since a temperature sensor for detecting the temperature of the fuel in the fuel tank 40 is not provided, the temperature of the fuel in the fuel tank 40 ( It is determined whether or not the fuel in the fuel tank 40 is in an environment where it is likely to vaporize and become vapor using the intake air temperature Ta that reflects the fuel temperature. Therefore, the temperature difference between the assumed fuel temperature (fuel temperature) in the fuel tank 40 and the intake air temperature Ta is ΔT, and instead of the saturated steam curve, the saturated steam curve is calculated by ΔT with the gauge pressure constant. Based on FIG. 3 using the moved line L1, it is determined whether the state point Pst is located within the area A1. When the state point Pst is located in the area A1, it is determined that the environment is such that the fuel in the fuel tank 40 is easily vaporized and vapor is easily generated.

When the state point Pst is within the area A1, it is then determined whether the purge concentration Cp is equal to or higher than a predetermined concentration Cpref (step S140). The predetermined concentration Cpref is a value determined in advance based on experiments, analysis, machine learning, etc. as a threshold value for determining whether or not high concentration vapor is generated within the fuel tank 40. When the purge concentration Cp is less than the predetermined concentration Cpref, it is determined that high-concentration vapor is not generated in the fuel tank 40, and this routine is terminated. When the purge concentration Cp is greater than or equal to the predetermined concentration Cpref, the fuel It is determined that high concentration vapor is generated within the tank 40 (step S170), and this routine is ended.

If the state point Pst is outside the area A1, then it is determined whether the state point Pst is within the area A2 (step S150). As shown in FIG. 3, the region A2 is a region in which the relationship between the atmospheric pressure Pout and the intake air temperature Ta is on the higher pressure, lower temperature side than the line L1, and is on the lower pressure and higher temperature side than the line L2. Line L2 is the boundary between a region where no vapor is generated and a region where vapor is generated in the fuel that is most easily vaporized among multiple types of fuels with different specifications and manufacturers that can be used in the automobile 10 on the market. This is the line. Therefore, no vapor is generated in the region on the high-pressure, low-temperature side of the line L2.

When the state point Pst is outside the area A2 in step S150, it is determined that high concentration vapor is not generated within the fuel tank 40, and this routine is ended.

When the state point Pst is within the area A2 in step S150, it is then determined whether the state in which the integral term of the third term of the above equation (1) is equal to or greater than the predetermined value Vitref continues for a predetermined time tref or longer. (Step S160). Here, the predetermined value Vitref is a threshold value of the integral term for determining whether or not the integral term has become large because the fuel pressure Pf does not rise to the target fuel pressure Pf* even though the fuel pump 44 is being driven. be able to. The predetermined time tref is a time threshold for determining whether the state in which the integral term is equal to or greater than the predetermined value Vitref is due to the occurrence of high concentration vapor in the fuel tank 40. When a high concentration of vapor occurs in the fuel tank 40, a vapor lock occurs in which the fuel pressure Pf does not rise to the target fuel pressure Pf* even though the fuel pump 44 is being driven. At this time, since the integral term becomes large, if the integral term is equal to or greater than the predetermined value Vitref for a predetermined period of time tref or more, a high concentration of vapor is generated in the fuel tank 40, and such vapor lock occurs. It is thought that this is occurring. Therefore, the process in step S160 is a process for determining whether vapor is generated in the fuel tank 40 at such a high concentration that vapor lock occurs.

In step S160, when the integral term is less than the predetermined value Vitref, or when the state where the integral term is equal to or greater than the predetermined value Vitref does not continue for the predetermined time tref or more, vapor is generated in the fuel tank 40 at such a high concentration that vapor lock occurs. It is determined that this has not been done, and this routine ends.

In step S160, when the state in which the integral term is equal to or greater than the predetermined value Vitref continues for a predetermined time tref or more, it is determined that vapor is generated in the fuel tank 40 at a high concentration enough to cause vapor lock, and the fuel tank 40 is It is determined that high-concentration vapor is occurring within the engine (step S170), and this routine ends. Through such a determination, it is possible to more appropriately determine whether or not high concentration vapor is generated within the fuel tank 40.

Note that when it is determined in step S170 that a high concentration of vapor is generated in the fuel tank 40, the target fuel pressure Pf* is increased to control the fuel pump 44. Thereby, the vapor in the fuel pump 44 and the fuel passage 43 can be crushed by the fuel pressure of the fuel, and vapor lock can be eliminated.

According to the automobile 10 equipped with the fuel supply device of the embodiment described above, when the state point Pst is within the region A2 and the integral term is in a state equal to or greater than the predetermined value Vitref for a predetermined time tref or longer, the fuel By determining that high-concentration vapor is occurring within the fuel tank 40, it is possible to more appropriately determine whether high-concentration vapor is occurring within the fuel tank 40.

In the automobile 10 equipped with the fuel supply device of the embodiment, in steps S150 and S160 of FIG. 2, the state point Pst is within the region A2, and the state in which the integral term is equal to or greater than the predetermined value Vitref continues for a predetermined time tref or longer. When the fuel tank 40 is present, it is determined that a high concentration of vapor is generated within the fuel tank 40. However, if the integral term is greater than or equal to the predetermined value Vitref for a predetermined time tref or longer, it can be determined that vapor is occurring at a high concentration in the fuel tank 40 to the extent that vapor lock occurs, so step S150 is executed. Instead, it may be determined that high-concentration vapor is occurring within the fuel tank 40 when a state in which the integral term is equal to or greater than the predetermined value Vitref continues for a predetermined time tref or longer.

In the automobile 10 equipped with the fuel supply device of the embodiment, in steps S130 and S140 of FIG. 2, it is determined whether the state point Pst is within the area A1 and whether the purge concentration Cp is equal to or higher than the predetermined concentration Cpref. are doing. However, steps S150 and S160 may be executed after executing step S110 without executing steps S120 to S140.

In the automobile 10 equipped with the fuel supply device of the embodiment, the engine 12 is equipped with a fuel injection valve 26 (in-cylinder injection valve) that injects fuel into the cylinder. However, instead of or in addition to the fuel injection valve 26, a port injection valve that injects fuel into the intake port may be provided.

In the embodiment, the fuel supply device is provided in a vehicle 10 that runs using power from an engine 12. However, it may be in the form of a fuel supply device included in a hybrid vehicle that includes a motor in addition to an engine, or it may be in the form of a fuel supply device that is installed in a moving object other than a car, a factory, or the like and supplies fuel to the engine. Moreover, it may be in the form of a fuel supply device mounted on a device that operates using a fuel different from the engine.

The correspondence between the main elements of the embodiments and the main elements of the invention described in the column of means for solving the problems will be explained. In the embodiment, the fuel tank 40 corresponds to a "fuel tank," the fuel pump 44 corresponds to a "fuel pump," and the electronic control unit 70 corresponds to a "control device."

The correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of means for solving the problem is that the example implements the invention described in the column of means for solving the problem. Since this is an example for specifically explaining a form for solving the problem, it is not intended to limit the elements of the invention described in the column of means for solving the problems. In other words, the interpretation of the invention described in the column of means for solving the problem should be based on the description in that column, and the examples are based on the description of the invention described in the column of means for solving the problem. This is just one specific example.

Although the embodiments of the present invention have been described above using examples, the present invention is not limited to these examples in any way, and may be modified in various forms without departing from the gist of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICATION This invention can be utilized for the manufacturing industry of a fuel supply apparatus, etc.

10 automobile, 12 engine, 14 crankshaft, 14a crank position sensor, 15 water temperature sensor, 16 cam position sensor, 22 air cleaner, 23 intake pipe, 23a air flow meter, 23b temperature sensor, 24 throttle valve, 24a throttle position sensor, 26 fuel injection valve, 28 intake valve, 29 combustion chamber, 30 spark plug, 32 piston, 33 exhaust valve, 34 exhaust pipe, 35 purification device, 37 front air-fuel ratio sensor, 38 rear air-fuel ratio sensor, 40 fuel tank, 40a pressure sensor, 42 fuel supply device, 43 fuel passage, 43p fuel pressure sensor, 44 fuel pump, 44b rotation speed sensor, 45 relief passage, 46 relief valve, 50 vaporized fuel processing device, 51 introduction passage (vapor passage), 52 blockade valve, 52a blockade Valve position sensor, 52b stepping motor, 53 canister, 54 atmospheric release passage, 55 purge passage, 56 purge valve, 56a purge valve position sensor, 60 transmission, 62 differential gear, 64a, 64b drive wheels, 70 electronic control unit, 80 ignition switch , 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 89 atmospheric pressure sensor.

Claims (1)

a fuel tank for storing fuel;
a fuel pump that supplies the fuel in the fuel tank to a fuel passage;
a control device that controls the fuel pump using feedback control using a proportional term and an integral term based on the difference between the fuel pressure as the pressure of the fuel and the target fuel pressure;
A fuel supply device comprising:
The control device determines that high-concentration vapor has occurred in the fuel tank when a state in which the integral term is equal to or greater than a predetermined value continues for a predetermined time or more.

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