Fuel tank treatment device

Abstract

To provide a fuel tank treatment device that maintains good balance between passages for discharge from a fuel tank to outside during fuel supply.SOLUTION: A fuel tank treatment device 11 includes: a discharge passage 16 through which gas 15 discharged from a fuel tank 13 flows; a solenoid valve 17 interposed in the discharge passage 16; and an arithmetic control section 18 that regulates an opening of the solenoid valve 17. The arithmetic control section 18 regulates the opening of the solenoid valve 17 when fuel 12 is supplied to the fuel tank 13 on the basis of a state change when the internal pressure of the fuel tank 13 is reduced.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fuel tank treatment device that regulates the flow of gas during refueling. [Background technology]

[0002] In a vehicle powered by an engine, fuel is stored in a fuel tank. When refueling a fuel tank, fuel flows into the fuel tank through a filler opening. During refueling, vaporized gas is discharged to the outside from the filler opening and drain line, and the amount of vaporized gas discharged to the outside from the filler opening and drain line is regulated by the laws and regulations of each country. To satisfy these regulations, the current practice is to balance the flow rate between a circulation line that circulates vaporized gas generated during refueling near the filler opening and the drain line. Patent Documents 1 to 3 disclose inventions related to the pressure and path of gas generated from a fuel tank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-185227 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-77422 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-317708 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned invention leaves room for improvement in terms of effectively directing gases generated from the fuel tank to the outside during refueling.

[0005] Specifically, the release path through which gas is released from the fuel tank to the outside and parts such as valves deteriorate over time. Specifically, the conduit that serves as the release path becomes crushed or deformed. If the degree of deterioration is significant, it becomes difficult to balance the flow rates of the circulation line and the drain line.

[0006] Furthermore, parts such as valves provided in the release path have a certain degree of variation in performance due to tolerances during processing, etc. This variation in performance of parts also makes it difficult to balance the flow rates between the circulation line and the drain line.

[0007] The present invention has been made in consideration of these problems, and an object of the present invention is to provide a fuel tank treatment device that maintains a good balance between the various paths through which fuel is released from the fuel tank to the outside when refueling. [Means for solving the problem]

[0008] The fuel tank treatment device of the present invention comprises a release path through which gas released from a fuel tank flows, a valve interposed in the release path, and an arithmetic control unit that adjusts the opening of the valve, and is characterized in that the arithmetic control unit adjusts the opening of the valve when fuel is being refueled into the fuel tank based on a change in state when the internal pressure of the fuel tank is reduced. [Effects of the Invention]

[0009] The fuel tank treatment device of the present invention adjusts the valve opening based on changes in the state of the fuel tank, thereby making it possible to maintain an appropriate pressure loss in the release path. In other words, the amount of gas passing through the fuel supply pipe and release path can be optimized, allowing fuel to be smoothly supplied to the fuel tank. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram showing a connection configuration of a vehicle equipped with a fuel tank processing device according to an embodiment of the present invention. [Figure 2] 5 is a flowchart showing a method for changing the opening degree of an electromagnetic valve by the fuel tank processing device according to the embodiment of the present invention. [Figure 3] 4 is a flowchart illustrating a method for estimating pressure loss in a release path by a fuel tank processing device according to an embodiment of the present invention. [Figure 4] 5 is a flowchart showing a method for estimating an adjustment value of an electromagnetic valve by a fuel tank processing device according to an embodiment of the present invention. [Figure 5] 3 is a block diagram showing a gas path when the internal pressure of the fuel tank is reduced in the fuel tank treatment device according to the embodiment of the present invention. FIG. [Figure 6A] 10 is a table used to estimate pressure loss in a release path in a fuel tank treatment device according to an embodiment of the present invention. [Figure 6B] 10 is a table used when estimating an adjustment value for the opening degree of an electromagnetic valve in the fuel tank processing device according to the embodiment of the present invention. [Figure 7] 5 is a conceptual diagram showing adjustment of the opening degree of an electromagnetic valve in the fuel tank treatment device according to the embodiment of the present invention. FIG. [Figure 8] 1 is a block diagram showing a gas path during refueling in a fuel tank treatment device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0011] A fuel tank processing device 11 according to an embodiment of the present invention will be described in detail below with reference to the drawings. In the following description, the same components are generally designated by the same reference numerals, and repeated description will be omitted.

[0012] FIG. 1 is a block diagram showing the connection configuration of a vehicle 10 equipped with a fuel tank processing device 11.

[0013] Vehicle 10 is a means of transportation equipped with an engine. For example, vehicle 10 is an engine vehicle, an EV (Electric Vehicle), an HEV (Hybrid Electric Vehicle), a PHEV (Plug-in Hybrid Electric Vehicle), etc. Vehicle 10 may also be an EV equipped with an engine as a range extender.

[0014] The fuel tank treatment device 11 is a device that appropriately controls gas 15 generated from a fuel tank 13 during refueling. The fuel tank treatment device 11 mainly comprises a release path 16, an electromagnetic valve 17, and an arithmetic control unit 18. Here, the electromagnetic valve 17 corresponds to the valve recited in the claims.

[0015] The fuel tank 13 is a device that stores fuel 12 to be supplied to an engine (not shown). The fuel 12 may be, for example, gasoline, diesel, or mixed oil.

[0016] The fuel filler pipe 19 is provided on the top of the fuel tank 13. The fuel filler pipe 19 is a generally cylindrical device and is disposed so as to communicate between the fuel tank 13 and the outside. A nozzle of a fuel filler gun is inserted into the fuel filler pipe 19 when fuel 12 is being supplied to the fuel tank 13. The outer end of the fuel filler pipe 19 is sealed by a lid 26.

[0017] The internal pressure sensor 21 is a device that measures the pressure inside the fuel tank 13. An electric signal indicating the internal pressure of the fuel tank 13 measured by the internal pressure sensor 21 is transmitted to the calculation control unit 18.

[0018] The arithmetic control unit 18 is made up of a CPU, RAM, ROM, timer, etc., and executes predetermined arithmetic control processing based on input signals, etc., input from the internal pressure sensor 21, etc. The arithmetic control unit 18 adjusts the opening of the electromagnetic valve 17, and as will be described later, adjusts the opening of the electromagnetic valve 17 when fuel 12 is supplied to the fuel tank 13 based on a state change when the internal pressure of the fuel tank 13 is reduced. The arithmetic control unit 18 also has a memory unit, and this memory unit stores programs for executing each process of the fuel tank processing device 11, which will be described later.

[0019] The release path 16 is a path through which the gas 15 released from the fuel tank 13 flows. The release path 16 is a conduit that connects the vent valve 14 with the outside of the fuel tank 13 and is configured to allow the gas 15 released from the fuel tank 13 to flow through. The release path 16 is a pipe or the like made of synthetic resin, metal, or the like. The gas 15 is evaporated gas from the fuel 12, air present in the fuel tank 13, or a mixture of evaporated gas and air.

[0020] In the release path 16, from the upstream side in the flow of the gas 15, an FCV 28, a vent valve 14, an electromagnetic valve 17, a canister 20, an ELCM 23, a drain filter 22, and the like are installed.

[0021] The fuel path 27 is a pipe that branches off from the portion of the discharge path 16 where the canister 20 is disposed. The fuel path 27 is a pipe or the like made of synthetic resin, metal, or the like.

[0022] The FCV 28 is a valve for selectively cutting off the fuel supply, and is also called a fuel cut valve.

[0023] The vent valve 14 is disposed inside the fuel tank 13 in which the fuel 12 is stored. The vent valve 14 is a valve that closes when the liquid level of the fuel 12 inside the fuel tank 13 reaches a certain level or higher, thereby preventing the fuel 12 from leaking out.

[0024] The electromagnetic valve 17 is a device that is installed in the release path 16. The electromagnetic valve 17 is connected to an output terminal of the calculation control unit 18. The opening and closing operation and opening degree of the electromagnetic valve 17 are steplessly and linearly controlled by the calculation control unit 18. As will be described later, the opening degree of the electromagnetic valve 17 when refueling is set to a degree that allows the refueling operation to be smooth while appropriately controlling the amount of gas 15 that is released to the outside from the fuel supply pipe 19 and the release path 16.

[0025] The canister 20 contains an adsorbent made of activated carbon or the like inside. The adsorbent allows the canister 20 to adsorb vaporized fuel contained in the gas 15 that is discharged from the fuel tank 13 and flows through the release path 16.

[0026] The ELCM 23 is also called a pressure-reducing leak check module. The ELCM 23 is a device that checks the fuel tank 13 and the canister 20 for leaks.

[0027] The drain filter 22 is a filter for purifying the gas 15 passing through the discharge path 16 .

[0028] The CPC 24 is also referred to as a purge control solenoid valve. The opening of the CPC 24 is set according to the duty ratio of a control signal output from the calculation control unit 18. During leak diagnosis, the opening of the CPC 24 is adjusted according to the diagnosis situation. On the other hand, during normal control, the opening of the CPC 24 is controlled according to the operating state.

[0029] The intake manifold 25 is a device that distributes air to the intake ports of each cylinder of the engine (not shown here).

[0030] The vent pipe 29 is a conduit having a substantially cylindrical shape, and its upper end is connected to the middle of the fuel supply pipe 19, and its lower end is connected to the fuel tank 13. As will be described later, when fuel 12 is supplied to the fuel tank 13, gas 15 inside the fuel tank 13 circulates among the vent pipe 29, the fuel supply pipe 19, and the fuel tank 13.

[0031] FIG. 2 is a flowchart showing a method for changing the opening degree of the electromagnetic valve 17 by the fuel tank processing device 11 when fueling the fuel tank 13.

[0032] In step S10, the calculation control unit 18 estimates the pressure loss in the release path 16. Step S10 will be described in detail with reference to FIG.

[0033] In step S11, the calculation control unit 18 estimates the adjustment value of the electromagnetic valve 17. Step S11 will be described in detail with reference to FIG.

[0034] In step S12, the arithmetic and control unit 18 adjusts the opening degree of the electromagnetic valve 17. Step S12 will be described later with reference to FIGS.

[0035] After completing each of these steps, the user opens the lid 26 and fills the fuel 12 into the fuel tank 13 via the fuel filler pipe 19. After filling is complete, the user closes the lid 26.

[0036] FIG. 3 is a flowchart showing the above-mentioned step S10 in detail, that is, a flowchart showing a method for estimating the pressure loss in the release path 16 by the calculation control unit 18 of the fuel tank processing device 11.

[0037] In step S100, the calculation control unit 18 determines whether or not there is a refueling request. Here, a refueling request is, for example, an operation of a fuel filler lever, button, etc. (not shown) by an occupant or worker of the vehicle 10 to fill the fuel tank 13 with fuel 12.

[0038] If the answer is YES in step S100, that is, if there is a refueling request, the calculation control unit 18 proceeds to step S101.

[0039] If the answer is NO in step S100, that is, if there is no refueling request, the calculation control unit 18 returns to START.

[0040] In step S101, the calculation control unit 18 acquires the internal pressure of the fuel tank 13. Specifically, the calculation control unit 18 measures the internal pressure of the fuel tank 13 using the internal pressure sensor 21.

[0041] In step S102, the calculation control unit 18 measures the amount of fuel 12 present inside the fuel tank 13 using a fuel level sensor (not shown).

[0042] In step S103, the calculation control unit 18 determines the amount of air in the fuel tank 13. That is, the amount of air present in the fuel tank 13 is calculated by subtracting the volume of the fuel 12 present in the fuel tank 13 from the total volume of the fuel tank 13.

[0043] In step S104, the arithmetic and control unit 18 opens the electromagnetic valve 17 by a predetermined opening amount. Specifically, the arithmetic and control unit 18 sets the opening amount of the electromagnetic valve 17 to, for example, 50%.

[0044] Fig. 5 is a block diagram showing the situation in which the pressure in the fuel tank 13 is reduced in step S104. In Fig. 5, the path through which the gas 15 inside the fuel tank 13 is discharged is indicated by a dotted arrow. When the electromagnetic valve 17 is opened, the gas 15 present inside the fuel tank 13 is discharged to the outside of the fuel tank 13 via the discharge path 16. Specifically, the gas 15 is discharged from inside the fuel tank 13 to the outside, for example, outside the vehicle, via the electromagnetic valve 17, the canister 20, the ELCM 23, and the drain filter 22, which are installed in the discharge path 16.

[0045] In step S105, the calculation control unit 18 determines whether or not the pressure reduction in the fuel tank 13 has been completed based on the output value of the internal pressure sensor 21. For example, the calculation control unit 18 determines that the pressure reduction in the fuel tank 13 has been completed when the internal pressure of the fuel tank 13 becomes equal to atmospheric pressure.

[0046] If step S105 is YES, that is, if the depressurization of the fuel tank 13 is completed, the calculation control unit 18 proceeds to step S106.

[0047] If step S105 is NO, that is, if the pressure reduction in the fuel tank 13 has not been completed, the calculation control unit 18 returns to step S104.

[0048] In step S106, the calculation control unit 18 acquires the time required for the pressure in the fuel tank 13 to be reduced.

[0049] In step S107, the calculation control unit 18 calculates the pressure loss in the release path 16 when the electromagnetic valve 17 is opened by a predetermined opening amount.

[0050] The operation of the calculation control unit 18 in step S107 will be described with reference to Figures 6A and 6B. First, using the correspondence table shown in Figure 6A, the pressure loss in the release path 16 is estimated from the amount of fuel 12 inside the fuel tank 13, the time required for depressurization, and the internal pressure of the fuel tank 13.

[0051] The table shown in Fig. 6A is a correspondence table used to estimate pressure loss when depressurizing the fuel tank 13 using the fuel tank processing device 11. Such a correspondence table is also called a look-up table in which output values ​​are pre-assigned according to input information. The input values ​​in the correspondence table shown in Fig. 6A are the time required for depressurization and the internal pressure of the fuel tank 13 before depressurization. The time required for depressurization is, for example, the time required for the internal pressure of the fuel tank 13 to change to atmospheric pressure.

[0052] The output value here is the pressure loss in the discharge path 16, and is also called drain pressure loss. In this embodiment, a plurality of correspondence tables are prepared according to the amount of fuel 12 inside the fuel tank 13. For example, correspondence tables are prepared for the amount of fuel 12 in increments of one liter from 0 liters to 70 liters.

[0053] Here, the interrelationships among the time required for depressurization, the internal pressure of the fuel tank 13, the amount of fuel 12 inside the fuel tank 13, and the pressure loss in the release path 16 are very complex. Furthermore, these interrelationships cannot be uniquely determined due to factors such as the degree of clogging of the drain filter 22, the adsorption state of the canister 20, and deformation of the piping that constitutes the release path 16. In this embodiment, in consideration of these complex interrelationships, a correspondence table is prepared in advance, thereby enabling the pressure loss in the release path 16 to be estimated easily and quickly.

[0054] For example, if the amount of fuel 12 inside the fuel tank 13 is 0 liters, the time required for depressurization is 8 seconds, and the internal pressure of the fuel tank 13 is 28 kPa, the pressure loss in the release path 16 is estimated to be 1.4 kPa.

[0055] The above-mentioned step S11, that is, the step of estimating the adjustment value of the opening degree of the electromagnetic valve 17, will be described with reference to FIG.

[0056] In step S201, the calculation control unit 18 acquires the pressure loss in the discharge path 16 described above.

[0057] In step S202, the calculation control unit 18 estimates a correction value for the electromagnetic valve 17 based on the value of the pressure loss in the release path 16.

[0058] Step S202 will be described with reference to the table of Fig. 6B. Here, the upper numerical values ​​indicate the estimated pressure loss in the release path 16, and the lower numerical values ​​indicate values ​​for correcting the opening degree of the electromagnetic valve 17.

[0059] For example, in step S104 described above, it is assumed that the opening of electromagnetic valve 17 is 50% and the pressure loss of release path 16 to be set is 1.7 kPa. If the pressure loss of release path 16 estimated in step S107 described above is 1.4 kPa, referring to the diagram shown in FIG. 6B, the opening correction value is −6.0%. That is, the set opening of electromagnetic valve 17 is 44%.

[0060] 7 is a conceptual diagram showing adjustment of the opening degree of the electromagnetic valve 17 in the fuel tank processing device 11. Here, a first case and a second case are shown, in which the estimated pressure loss is different.

[0061] In the first case, the estimated pressure loss is lower than the target pressure loss. Therefore, by reducing the opening of the electromagnetic valve 17, the pressure loss in the discharge path 16 is increased to be equal to the target pressure loss.

[0062] In the second case, conversely, the estimated pressure loss is higher than the target pressure loss, so the opening of the electromagnetic valve 17 is increased to reduce the pressure loss in the discharge path 16 and make it equal to the target pressure loss.

[0063] By doing so, the pressure loss in the release path 16 can be made closer to the target pressure loss, and when refueling as described below, the gas 15 can be efficiently released to the outside via the release path 16, and further the gas 15 can be circulated in the vicinity of the fuel supply pipe 19.

[0064] 8 is a block diagram showing the path of gas 15 during refueling. Here, lid 26 is removed from fuel fill pipe 19, and the nozzle of fuel fill gun 30 is inserted into fuel fill pipe 19. In this state, fuel 12 is supplied to fuel tank 13 via fuel fill gun 30.

[0065] As fuel is being refueled, part of the gas 15 inside the fuel tank 13 is released to the outside via the release path 16. In addition, part of the gas 15 circulates between the ventilation pipe 29, the fuel supply pipe 19, and the fuel tank 13.

[0066] In this embodiment, as described above, by adjusting the opening of the electromagnetic valve 17, the pressure loss in the release path 16 is made to approximate a target value. Therefore, a portion of the gas 15 is efficiently released to the outside via the release path 16. In addition, another portion of the gas 15 is efficiently circulated between the fuel tank 13, the vent pipe 29, and the fuel supply pipe 19. This makes it possible to comply with the laws and regulations of each country regarding the leakage of the gas 15 to the outside. Furthermore, the fuel 12 can be smoothly supplied.

[0067] The technical ideas that can be understood from the above-described embodiment will be described below together with their effects.

[0068] The fuel tank treatment device of the present invention includes a release path through which gas released from a fuel tank flows, a valve installed in the release path, and a calculation and control unit that adjusts the valve opening, and the calculation and control unit adjusts the valve opening when fuel is being supplied to the fuel tank based on state changes caused by reducing the internal pressure of the fuel tank.The fuel tank treatment device of the present invention adjusts the valve opening based on state changes in the fuel tank, thereby making it possible to maintain an appropriate pressure loss in the release path.In other words, fuel can be smoothly supplied to the fuel tank while optimizing the amount of gas passing through the fuel supply pipe and release path.

[0069] In addition, in the fuel tank treatment device of the present invention, the calculation control unit estimates the pressure loss in the release path based on the state change and adjusts the opening of the valve based on the pressure loss. According to the fuel tank treatment device of the present invention, even if deterioration of the pipe line in the release path occurs, the pressure loss in the release path can be appropriately adjusted depending on the condition of the release path.

[0070] In addition, in the fuel tank processing device of the present invention, the calculation control unit estimates the pressure loss in the release path based on the time required to depressurize the fuel tank, the internal pressure of the fuel tank, and the amount of fuel present in the fuel tank. According to the fuel tank processing device of the present invention, the pressure loss in the release path can be accurately estimated.

[0071] In addition, in the fuel tank processing device of the present invention, when the operation to perform refueling is performed, the calculation control unit opens the valve to release the gas from inside the fuel tank to the outside, estimates the pressure loss in the release path based on the state change when the valve is opened, and adjusts the opening of the valve based on the pressure loss when refueling the fuel tank. According to the fuel tank processing device of the present invention, by estimating the pressure loss in the release path prior to refueling and adjusting the opening of the valve based on the pressure loss, it is possible to effectively release the gas from the fuel tank to the outside and further to smoothly refuel the fuel tank.

[0072] Although the embodiments of the present invention have been described above, the present invention is not limited to these and can be modified within the scope of the present invention. In addition, the above-described embodiments can be combined with each other. [Explanation of symbols]

[0073] 10 vehicles 11 Fuel tank treatment equipment 12 Fuel 13. Fuel tank 14 Vent valve 15 Gases 16 Release Pathway 17 Solenoid valve 18 Calculation control unit 19 Fuel Pipe 20 canisters 21 Internal pressure sensor 22 Drain filter 23 ELCM 24 CPC 25 intake manifold 26 Lid 27 Fuel line 28 FCV 29 Ventilation Pipe 30 Fuel Gun

Claims

1. a release path through which gas released from the fuel tank flows; a valve interposed in the discharge path; a calculation control unit that adjusts the opening degree of the valve, The fuel tank processing device is characterized in that the calculation control unit adjusts the opening degree of the valve when refueling the fuel tank based on a state change when the internal pressure of the fuel tank is reduced.

2. The arithmetic and control unit estimating a pressure loss in the release path based on the state change; 2. The fuel tank treatment device according to claim 1, wherein the opening of the valve is adjusted based on the pressure loss.

3. The arithmetic and control unit 3. The fuel tank processing device according to claim 2, wherein the pressure loss in the release path is estimated based on the time required to depressurize the fuel tank, the internal pressure of the fuel tank, and the amount of fuel present inside the fuel tank.

4. The arithmetic and control unit When the operation for refueling is performed, By opening the valve, the gas is released from inside the fuel tank to the outside, estimating a pressure loss in the release path based on the state change when the valve is in the open state; 2. The fuel tank processing device according to claim 1, wherein the opening of the valve is adjusted based on the pressure loss when the fuel is supplied to the fuel tank.

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