JP7790261B2 - fuel supply device - Google Patents

Description

The present invention relates to a fuel supply system, and more particularly to a fuel supply system equipped with a fuel tank and a fuel pump.

Conventionally, this type of fuel supply system has been proposed to include a fuel tank, a fuel pump, and a surge tank (see, for example, Patent Document 1). The fuel tank stores fuel. The fuel pump supplies fuel to a fuel passage (fuel piping). The surge tank temporarily stores vapor generated in the fuel tank. This system determines that a high concentration of vapor is being generated in the fuel tank when the fuel supply system is located at a high altitude above a predetermined altitude, the fuel temperature in the fuel tank is above a predetermined temperature, and the pressure in the surge tank is below a predetermined pressure.

Special Publication No. 6-31576

However, in fuel supply systems that do not have a temperature sensor that directly detects the fuel temperature in the fuel tank, the above method cannot be used, resulting in the inconvenience of being unable to properly determine whether a high concentration of vapor is being generated in the fuel tank. To resolve this issue, a method can be considered that uses, instead of fuel temperature, another physical quantity that is correlated with fuel temperature to determine whether a high concentration of vapor is being generated in the fuel tank. However, with this method, if the correlation between the predicted fuel temperature and the other physical quantity deviates from the actual correlation for some reason, it will no longer be possible to properly determine whether a high concentration of vapor is being generated in the fuel tank.

The primary purpose of the fuel supply device of the present invention is to more accurately determine whether a high concentration of vapor is being generated in the fuel tank.

The fuel supply device of the present invention employs the following measures to achieve the above-mentioned primary objective.

The fuel supply device of the present invention comprises:
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 with 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 comprising:
The control device determines that a high concentration of vapor has been generated in the fuel tank when the integral term remains equal to or greater than a predetermined value for a predetermined period of time.

The fuel supply system of the present invention controls the fuel pump using feedback control with a proportional term and an integral term based on the difference between the fuel pressure (as fuel pressure) and the target fuel pressure. When the integral term remains above a predetermined value for a predetermined period of time or longer, it is determined that a high concentration of vapor has been generated in the fuel tank. When a high concentration of vapor has been generated in the fuel tank, vapor lock occurs, in which the fuel pressure does not rise to the target fuel pressure despite the fuel pump being driven. Because the integral term increases in this state, when the integral term remains above a predetermined value for a predetermined period of time or longer, it is considered that a high concentration of vapor has been generated in the fuel tank, and vapor lock has occurred. Therefore, by determining that a high concentration of vapor has been generated in the fuel tank when the integral term remains above a predetermined value for a predetermined period of time or longer, it is possible to more accurately determine whether a high concentration of vapor has been generated in the fuel tank. Here, the "predetermined value" may be, for example, a threshold value for the integral term used to determine whether the integral term has increased because the fuel pressure has not risen to the target fuel pressure despite the fuel pump being driven. The "predetermined time" is a time threshold used to determine whether the state in which the integral term has exceeded a predetermined value is due to the generation of high-concentration vapor in the fuel tank.

In the fuel supply system of the present invention, the control device may determine that a high concentration of vapor has been generated in the fuel tank when a predetermined condition is met, which at least includes a predetermined state in which the fuel in the fuel tank is likely to vaporize, and when a state in which the integral term is equal to or greater than the predetermined value continues for the predetermined time or longer even when the predetermined condition is not met. This makes it possible to more accurately determine whether a high concentration of vapor has been generated in the fuel tank. Here, examples of the "predetermined state" include when the atmospheric pressure is low and the fuel temperature is high, such as when the vehicle is in a high-temperature environment at high altitude.

Furthermore, in the fuel supply system of the present invention, when the control device determines that a high concentration of vapor has been generated in the fuel tank, the control device may increase the target fuel pressure compared to when it has not determined that a high concentration of vapor has been generated in the fuel tank. This allows the fuel pressure to crush vapor in the fuel pump and fuel passages, thereby eliminating vapor lock.

The fuel supply processing device of the present invention is a fuel supply device according to any of the above-described aspects of the present invention, i.e., a fuel supply device basically comprising a fuel tank for storing fuel, a fuel pump for supplying the fuel in the fuel tank to a fuel passage, and a control device for controlling the fuel pump using feedback control with a proportional term and an integral term based on the difference between a fuel pressure as the pressure of the fuel and a target fuel pressure, wherein the control device determines that a high concentration of vapor has been generated 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 longer;
a vaporized fuel processing device having a canister connected to the fuel tank via a vapor passage and a purge passage connecting the canister to an intake pipe of an engine;
The gist of the project is to provide the following:

This fuel supply processing device of the present invention is equipped with any of the fuel supply devices of the present invention described above, and therefore achieves the effect of the fuel supply device of the present invention, namely, the ability to more accurately determine whether a high concentration of vapor is being generated in the fuel tank.

In this case, the predetermined condition may be that the purge concentration, which is the ratio of vapor to the amount of gas supplied to the intake pipe, is equal to or greater than a predetermined concentration. This has the effect of more accurately determining whether a high concentration of vapor is occurring in the fuel tank. Here, the "predetermined concentration" may be, for example, a purge concentration threshold value for determining whether a high concentration of vapor is occurring in the fuel tank.

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

Next, we will explain how to implement the present invention using examples.

Figure 1 is a schematic diagram showing the configuration of an automobile 10 equipped with a fuel supply processing device according to one embodiment of the present invention. As shown, the automobile 10 of the embodiment includes an engine 12, a fuel supply device 42, a vaporized fuel processing device 50, a transmission 60 connected to the crankshaft 14 of the engine 12 and to drive wheels 64a, 64b via a differential gear 62, 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 primarily consists of the fuel supply device 42 and the electronic control unit 70.

The engine 12 is an internal combustion engine that uses fuel such as gasoline or diesel fuel from a fuel tank 40 to generate power through four cycles: intake, compression, expansion, and exhaust. The engine 12 draws purified air into an intake pipe 23, passes it through a throttle valve 24, and injects fuel from a fuel injection valve 26 downstream of the throttle valve 24 into the intake pipe 23, mixing the air and fuel. This mixture is then drawn into a combustion chamber 29 via an intake valve 28 and explosively combusted by an electric spark from an ignition plug 30. The reciprocating motion of a piston 32, which is pushed down by the energy of the explosive combustion, is converted into rotational motion of the crankshaft 14. Exhaust gas is discharged from the combustion chamber 29 through an exhaust valve 33 into an exhaust pipe 34 and then discharged into the atmosphere via a 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 supply fuel from within the fuel tank 40 to the fuel injection valve 26. The 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 from within 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 fuel pressure (fuel pressure Pf) in the fuel passage 43 is less than the valve opening pressure Pfrv of the relief valve 46, and opens when the fuel pressure in the fuel passage 43 is equal to or greater than the valve opening pressure Pfrv. When the relief valve 46 opens, some of the fuel in the fuel passage 43 is returned to the fuel tank 40 via the relief passage 45. In this way, the fuel pressure in the fuel passage 43 is prevented from becoming excessive.

The vaporized fuel processing device 50 is configured to perform purging, supplying vaporized fuel gas (purge gas) containing vaporized fuel generated in the fuel tank 40 to the intake pipe 23. This vaporized fuel processing device 50 includes an introduction passage (vapor passage) 51, a shutoff valve 52, a canister 53, a purge passage 55, and a purge valve 56.

The inlet passage (vapor passage) 51 is connected to the fuel tank 40 and the canister 53. The shut-off valve 52 is provided in the inlet passage (vapor passage) 51 and is configured as a normally closed electromagnetic valve.

The shut-off valve 52 is a flow control valve that, when closed, closes the inlet passage (vapor passage) 51, blocking communication between the fuel tank 40 and the canister 53, and, when open, regulates the flow rate of gas flowing through the inlet passage (vapor passage) 51. The shut-off valve 52 includes a valve seat (not shown) formed in the casing, a valve element (not shown) disposed within the casing for axial movement, and a stepping motor 52b disposed within the casing and connected to the valve element via a valve guide (not shown). The stepping motor 52b moves the valve element axially back and forth relative to the valve seat. Operation of the stepping motor 52b moves the valve element toward the valve seat, causing a sealing element (not shown) of the valve element to abut against the valve seat, thereby closing the shut-off valve 52. Operation of the stepping motor 52b also moves the valve element away from the valve seat, causing the sealing element (not shown) of the valve element to move away from the valve seat, thereby opening the shut-off valve 52. The stepping motor 52b is controlled by the electronic control unit 70.

The canister 53 is connected to the intake passage (vapor passage) 51 and the purge passage 55, and is open to the atmosphere via the atmosphere vent passage 54. The interior 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 vent 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 electromagnetic valve. This purge valve 56 is controlled by the electronic control unit 70.

This vaporized fuel processing device 50 performs purging by adjusting the opening of the purge valve 56 when the shut-off valve 52 is open. Specifically, it utilizes the negative pressure in the intake pipe 23 to supply purge gas containing vapor (vaporized fuel) generated in the fuel tank 40 to the intake pipe 23 via the introduction passage (vapor passage) 51, canister 53, and purge passage 55, with the flow rate adjusted. 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 around a CPU, and in addition to the CPU, it is equipped with ROM for storing processing programs, RAM for temporarily storing data, flash memory for storing and retaining data, and input/output ports. Signals from various sensors are input to the electronic control unit 70 via the input ports.

Signals input to the electronic control unit 70 include, for example, the crank angle θcr from the crank position sensor 14a, which detects the rotational position of the crankshaft 14 of the engine 12, and the coolant temperature Tw from the water temperature sensor 15, which detects the temperature of the coolant for the engine 12. Other signals include the throttle opening TH from the throttle position sensor 24a, which detects the opening (position) of the throttle valve 24, and the cam angles θci and θco from the cam position sensor 16, which detects the rotational positions of the intake camshaft that opens and closes the intake valve 28 and the exhaust camshaft that opens and closes the exhaust valve 33. Other examples of the intake air quantity Qa include the intake air amount Qa from the air flow meter 23a attached upstream of the throttle valve 24 in the intake pipe 23, the intake air temperature Ta from the temperature sensor 23b attached 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 attached upstream of the purifier 35 in the exhaust pipe 34, and the rear air-fuel ratio AF2 from the rear air-fuel ratio sensor 38 attached downstream of the purifier 35 in the exhaust pipe 34. Other examples of the intake air quantity Qa include the intake air quantity ... Other examples include the opening degree Osv of the shut-off valve 52 from the shut-off valve position sensor 52a, which detects the opening degree (position) of the shut-off valve 52, and the opening degree Opv of the purge valve 56 from the purge valve position sensor 56a, which detects the opening degree (position) of the purge valve 56. Other examples include an ignition signal IG from the ignition switch 80 and a shift position SP from a shift position sensor 82, which detects the operating position of the shift lever 81. Other examples include an accelerator opening Acc from an accelerator pedal position sensor 84, which detects the depression amount of the accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86, which detects the depression amount of the brake pedal 85, a vehicle speed V from a vehicle speed sensor 88, and an atmospheric pressure Pout from an atmospheric pressure sensor 89.

Various control signals are output from the electronic control unit 70 via output ports. Examples of signals output from the electronic control unit 70 include 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, a control signal to the shut-off valve 52, and a control signal to the purge valve 56. Other examples include a control signal to the transmission 60 and a control signal to a starter (not shown).

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

In the automobile 10 of this embodiment configured as described above, the electronic control unit 70 controls the operation of the engine 12 based on the required load factor KL* of the engine 12, which is based on the accelerator pedal position Acc and the vehicle speed V. Specifically, it controls the intake air amount to control the opening of the throttle valve 24, fuel injection to control the amount of fuel injected from the fuel injection valve 26, and ignition to control the ignition timing of the spark plug 30. The electronic control unit 70 also controls the fuel pump 44 of the fuel supply device 42, and the shut-off valve 52 and purge valve 56 of the vaporized fuel processing device 50.

In the operation control of the engine 12, in intake air volume control, the electronic control unit 70 sets a target opening TH* of the throttle valve 24 based on the required load factor KL* of the engine 12 and controls the throttle valve 24 using the set target opening TH*. In fuel injection control, a target injection amount Qf* is set as a basic fuel injection amount Qfb based on the engine 12 rotation speed and intake manifold pressure multiplied by a correction coefficient based on various sensor values detecting the state of the engine 12, and the fuel injection valve 26 is controlled so that the fuel injection amount from the fuel injection valve 26 becomes the target injection amount Qf*. In ignition control, the electronic control unit 70 sets a target ignition timing Ti* of the spark plug 30 based on the engine 12 rotation speed Ne and load factor KL and controls the spark plug 30 using the set target ignition timing Ti*. When the tank internal pressure Pt (gauge pressure) is equal to or lower than a threshold Ptref slightly higher than 0 kPa, the shut-off valve 52 is controlled to be closed. When the tank internal pressure Pt is higher than the threshold Ptref, the shut-off valve 52 is controlled to be open. When the purge condition is met, the purge valve 56 is controlled to be open so that the above-mentioned purge is performed. When the purge condition is not met, the purge valve 56 is controlled to be closed. Examples of purge conditions include when the cooling water temperature Tw is equal to or higher than a threshold, operation control of the engine 12 (such as fuel injection control) is being performed, and the shut-off valve 52 is open.

In controlling the fuel pump 44, the target discharge flow rate Qp* of the fuel pump 44 is repeatedly set at predetermined time intervals (e.g., every few msec) using the following equation (1) based on the difference between the fuel pressure Pf detected by the fuel pressure sensor 43p and the target fuel pressure Pf*. The fuel pump 44 is then 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 the 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 the 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 and controlled using feedback control with 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*.

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

Next, we will explain the operation of the automobile 10 of this embodiment, particularly the operation when determining whether the vapor concentration in the fuel tank 40 is high. Figure 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 (e.g., every few milliseconds) when the shut-off valve 52 and purge valve 56 are open.

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

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

Next, it is determined whether the state point Pst is located within region A1, which indicates that the fuel in the fuel tank 40 is in an environment where it is likely to vaporize (step S130). Figure 3 is an explanatory diagram showing an example of region A1. Figure 4 is an explanatory diagram for explaining line L1 in Figure 3. In Figure 4, the dashed line Lpv indicates the saturated vapor curve of the fuel. Region A1 is a region where the relationship between atmospheric pressure Pout and intake air temperature Ta is lower-pressure and higher-temperature than line L1. The fuel in the fuel tank 40 is in an environment where it is likely to vaporize if the position of state point Ps, which is determined by the gauge pressure (pressure) in the fuel tank 40 and the temperature (fuel temperature) of the fuel in the fuel tank 40, is in region Apv, which is lower-pressure and higher-temperature than the saturated vapor curve (dashed line Lpv). In this embodiment, since no temperature sensor is provided to detect the temperature of the fuel in the fuel tank 40, the intake air temperature Ta, which reflects the temperature of the fuel in the fuel tank 40, is used instead of the temperature of the fuel in the fuel tank 40 to determine whether the environment in the fuel tank 40 is prone to vaporization and generation of vapor. Therefore, the temperature difference between the assumed fuel temperature in the fuel tank 40 and the intake air temperature Ta is defined as ΔT, and instead of the saturated vapor curve, line L1, which is obtained by shifting the saturated vapor curve by ΔT while maintaining a constant gauge pressure, is used to determine whether state point Pst is located within region A1. When state point Pst is located within region A1, it is determined that the environment in the fuel tank 40 is prone to vaporization and generation of vapor.

If the state point Pst is within region A1, the routine then determines whether the purge concentration Cp is equal to or greater than a predetermined concentration Cpref (step S140). The predetermined concentration Cpref is a threshold value determined in advance through experiments, analysis, machine learning, etc., as a threshold for determining whether a high concentration of vapor is being generated in the fuel tank 40. If the purge concentration Cp is less than the predetermined concentration Cpref, it is determined that a high concentration of vapor is not being generated in the fuel tank 40, and the routine is terminated. If the purge concentration Cp is equal to or greater than the predetermined concentration Cpref, it is determined that a high concentration of vapor is being generated in the fuel tank 40 (step S170), and the routine is terminated.

If state point Pst is outside region A1, it is next determined whether state point Pst is within region A2 (step S150). As shown in Figure 3, region A2 is a region on the high-pressure/low-temperature side of line L1 in the relationship between atmospheric pressure Pout and intake air temperature Ta, and a region on the low-pressure/high-temperature side of line L2. Line L2 marks the boundary between a region where vapor is not generated and a region where vapor is generated for the most vaporizable fuel among the multiple types of fuels available for commercially available automobiles 10, which vary in specifications and manufacturers. Therefore, vapor is not generated in the high-pressure/low-temperature region on the high-pressure/low-temperature side of line L2.

If, in step S150, the state point Pst is outside region A2, it is determined that high concentration vapor is not being generated in the fuel tank 40, and this routine is terminated.

If the state point Pst is within region A2 in step S150, the process then determines whether the integral term of the third term in equation (1) above is equal to or greater than a predetermined value Vitref for a predetermined time tref or longer (step S160). Here, the predetermined value Vitref may be an integral term threshold value used to determine whether the integral term is large because the fuel pressure Pf does not rise to the target fuel pressure Pf* despite the fuel pump 44 being driven. The predetermined time tref is a time threshold value used to determine whether the integral term being equal to or greater than the predetermined value Vitref is due to the generation of a high concentration of vapor in the fuel tank 40. If a high concentration of vapor is generated in the fuel tank 40, vapor lock occurs, in which the fuel pressure Pf does not rise to the target fuel pressure Pf* despite the fuel pump 44 being driven. Because the integral term becomes large in this case, if the integral term is equal to or greater than the predetermined value Vitref for a predetermined time tref or longer, it is considered that a high concentration of vapor is generated in the fuel tank 40, causing vapor lock. Therefore, step S160 determines whether a high concentration of vapor is being generated in the fuel tank 40 such that vapor lock may occur.

If, in step S160, the integral term is less than the predetermined value Vitref, or if the integral term does not remain at or above the predetermined value Vitref for a predetermined time tref or longer, it is determined that the concentration of vapor generated in the fuel tank 40 is not high enough to cause vapor lock, and this routine is terminated.

If, in step S160, the integral term remains equal to or greater than the predetermined value Vitref for a predetermined time tref or longer, it is determined that a high concentration of vapor is being generated in the fuel tank 40, to the extent that vapor lock may occur, and the routine is terminated after determining that a high concentration of vapor is being generated in the fuel tank 40 (step S170). This type of determination makes it possible to more accurately determine whether a high concentration of vapor is being generated in the fuel tank 40.

If step S170 determines that a high concentration of vapor is occurring in the fuel tank 40, the target fuel pressure Pf* is increased to control the fuel pump 44. This allows the vapor in the fuel pump 44 and fuel passage 43 to be crushed by the fuel pressure, thereby eliminating vapor lock.

In a vehicle 10 equipped with the fuel supply system of the embodiment described above, when state point Pst is within region A2 and the integral term remains at or above the predetermined value Vitref for a predetermined time tref or longer, it is determined that a high concentration of vapor is being generated in the fuel tank 40, thereby making it possible to more accurately determine whether a high concentration of vapor is being generated in the fuel tank 40.

In a vehicle 10 equipped with the fuel supply system of the embodiment, in steps S150 and S160 of FIG. 2, if the state point Pst is within region A2 and the integral term remains above the predetermined value Vitref for a predetermined time tref or longer, it is determined that a high concentration of vapor is being generated in the fuel tank 40. However, if the integral term remains above the predetermined value Vitref for a predetermined time tref or longer, it can be determined that a high concentration of vapor is being generated in the fuel tank 40 to the extent that vapor lock may occur. Therefore, it is also possible to skip step S150 and determine that a high concentration of vapor is being generated in the fuel tank 40 when the integral term remains above the predetermined value Vitref for a predetermined time tref or longer.

In a vehicle 10 equipped with the fuel supply system of this embodiment, steps S130 and S140 in FIG. 2 determine whether the state point Pst is within area A1 and whether the purge concentration Cp is equal to or greater than the predetermined concentration Cpref. However, steps S150 and S160 may be performed after step S110 without performing steps S120 to S140.

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

In the embodiment, the fuel supply device is provided in an automobile 10 that runs using power from an engine 12. However, it may also be provided in a hybrid automobile that has a motor in addition to an engine, or in a fuel supply device installed in a moving object other than an automobile, such as a factory, that supplies fuel to an engine. It may also be provided in a fuel supply device mounted on a device that runs on a fuel other than an engine.

The following explains the correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section. In the embodiment, the fuel tank 40 corresponds to the "fuel tank," the fuel pump 44 corresponds to the "fuel pump," and the electronic control unit 70 corresponds to the "control device."

The correspondence between the main elements of the Examples and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, as the Examples are examples used to specifically explain the form for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the Examples are merely specific examples of the invention described in the "Means for Solving the Problem" section.

The above describes the form for carrying out the present invention using examples, but the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the present invention.

This invention can be used in industries such as fuel supply device manufacturing.

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 Revolution speed sensor, 45 Relief passage, 46 Relief valve, 50 Vaporized fuel treatment device, 51 Inlet passage (vapor passage), 52 Blocking valve, 52a Shutoff valve position sensor, 52b stepping motor, 53 canister, 54 atmosphere 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 with 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 comprising:
The control device determines that a high concentration of vapor has been generated in the fuel tank when a predetermined condition is met indicating that the fuel in the fuel tank is in an environment where vapor is likely to be vaporized and vapor is likely to be generated, and when a condition is met indicating that a high concentration of vapor has been generated in the fuel tank, and when a state in which the integral term is equal to or greater than a predetermined value continues for a predetermined time or longer even though the predetermined condition is not met.