JP3216539B2 - Fuel supply device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for supplying fuel to an internal combustion engine. More specifically, the present invention relates to a fuel supply device for an internal combustion engine that discharges fuel from a fuel tank by a pump and pressure-feeds the fuel to the internal combustion engine, and that adjusts the fuel pressure according to the operating state of the internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as a device for supplying fuel to an internal combustion engine (engine) mounted on a rear-wheel drive type and a four-wheel drive type vehicle, a device as shown in FIG. Technology ”). This device has a fuel tank 6
1, a fuel pump 62, a jet pump 63, a fuel line 64, and a return line 65. In order to avoid interference with a propeller shaft (not shown), the tank 61 has a saddle shape, and the storage chamber 6 divided into two by a recess 70.
6,67. The fuel pump 62 and the jet pump 63 arranged in the first storage chamber 66
8 is supported by the tank 61. Fuel pump 62
Is connected to a delivery pipe (both not shown) via a filter and a pressure regulator. A return line 65 extending from the pressure regulator is connected to the jet pump 63. The connection hose 69 whose one end is connected to the jet pump 62 has the other end arranged in the second storage chamber 67.

[0003] The fuel discharged by the pump 62 passes through a fuel line 64, a filter and a pressure regulator, and is sent to a delivery pipe at a constant pressure. The pressure regulator adjusts the fuel pressure to be constant with respect to the intake pressure in an intake manifold (not shown). The regulator returns the excess fuel (return fuel) due to the adjustment of the fuel pressure to the first storage chamber 66 through the return line 65 and the jet pump 63. Here, when the return fuel passes through the jet pump 63, a negative pressure is generated inside the pump 63. The fuel in the second storage chamber 67 flows to the first storage chamber 66 via the connecting hose 69 by the suction force due to the negative pressure. Thus, even if the saddle-shaped tank 61 is used, the first storage chamber 66
One fuel pump 62 provided in both storage chambers 6
All the fuel in 6,67 can be discharged.

On the other hand, Japanese Patent Laying-Open No. 57-108427 discloses an apparatus having a configuration different from that of the first prior art described above (hereinafter referred to as "second prior art"). As shown in FIG. 7, the pressure regulator and the return line 65 are omitted in this device. This device includes an injector 74 provided in an engine 72 and a computer 73 for controlling an electric pump 75. In order to supply a required amount of fuel stored in the tank 71 to the engine 72, the computer 73 controls the valve opening time of the injector 74 according to the operating state of the engine 72. At the same time, the computer 73 changes the amount of fuel discharged from the fuel pump 75 into the operating state of the engine 72, in particular, the intake air amount Q and the rotation speed N of the engine 72.
Control is performed according to E. That is, the computer 73 controls the fuel pressure supplied to the injector 74 according to the operating state of the engine 72. In this device, since the conventional return line and pressure regulator are omitted, the configuration of piping and the like can be simplified.

[0005]

However, in the second prior art apparatus, there is no return fuel returned from the engine 72 to the tank 61. Therefore, the jet pump 63 described above cannot be applied to this device, and a tank having a plurality of storage chambers such as the saddle-shaped tank 61 described above cannot be applied. Therefore,
A device as shown in the second prior art is a rear-wheel drive type and a four-wheel drive type.
It cannot be applied to a wheel drive type vehicle, and the application range of this device is limited.

The present invention has been made in view of the above circumstances, and has as its object to provide a storage chamber in which one fuel pump is disposed and a storage chamber in which no fuel pump is disposed. In the fuel supply device, which controls the fuel pressure supplied to the internal combustion engine by controlling the fuel supply, the fuel stored in all the storage chambers can be supplied to the internal combustion engine by a pump. It is to provide a device.

[0007]

According to a first aspect of the present invention, as shown in FIG. 1, the fuel in a tank M1 is discharged by a pump M2 while discharging the fuel in a tank M1. A fuel supply device for controlling the pressure of the fuel supplied to the internal combustion engine M3 by controlling the pump M2, wherein the tank M1 includes a plurality of storage chambers M4 and M5.
And a pump M for that one particular reservoir M4
2, a branch passage M6 for returning a part of the fuel discharged from the pump M2 in the specific storage room M4 to the specific storage room M4, and a storage room M5 other than the specific storage room M4. A communication passage M for communicating the branch passage M6 with each other.
7 and the action force of the fuel flowing through the branch passage M6, the fuel in the storage chamber M5 other than the specific storage chamber M4 is connected to the communication path M7.
Means M for transferring to a specific storage room M4 through
8, an opening / closing means M9 provided in the branch passage M6 for opening and closing the passage M6, and a pump M2 so that the fuel pressure supplied to the internal combustion engine M3 becomes a target pressure according to the operating state of the internal combustion engine M3. Control means M1 for controlling the
0 and opening / closing means M for shutting off fuel flowing from the pump M2 to the branch passage M6 in accordance with the operation state of the internal combustion engine M3.
9 is provided with a second control unit M11 for controlling the control unit 9.

According to the above configuration, the plurality of storage chambers M4,
In a state where fuel is stored in M5, the operation of the pump M2 causes the fuel in the specific storage chamber M4 to be pumped and supplied to the internal combustion engine M3. The first control means M10 controls the amount of fuel discharged from the pump M2 such that the fuel pressure becomes a target fuel pressure according to the operation of the internal combustion engine M3. When the second control means controls the opening / closing means M9, the branch passage M6 is selectively opened / closed.

The branch passage M6 is controlled by the second control means M11.
Is opened, a part of the fuel discharged by the pump M2 is supplied to the branch passage M6. The amount of fuel required by the internal combustion engine M3 when the load is relatively small is smaller than the amount of fuel required when the load is relatively large. Therefore, when the load is small, the pump M2 supplies a sufficient amount of fuel to the internal combustion engine M3 and also supplies fuel to the branch passage M6. In a state where the branch passage M6 is closed by the second control means M11, the pump M2
Is supplied to the internal combustion engine M3. As described above, the second control unit M11 controls the branch passage M6.
, The internal combustion engine M3 and the branch passage M6
The amount of fuel supplied to is adjusted.

Here, when the fuel flows through the branch passage M6, an acting force of the fuel, for example, a negative pressure is generated in the branch passage M6. The transfer means M8 is operated by the action force of the fuel.
Fuel stored in a storage room M5 other than the specific storage room M4 is sucked through the communication path M7 and transferred to the specific storage room M4. Fuel transferred from the storage chamber M5 other than the specific storage chamber M4 is supplied to the internal combustion engine M3 by the pump M2. Thus, the fuel stored in the plurality of storage chambers M4 and M5 can be supplied together to the internal combustion engine M3.

In order to achieve the above object, according to a second aspect of the present invention, in the configuration similar to that of the first aspect shown in FIG. When the target pressure in the means M10 becomes equal to or higher than a predetermined value, the opening and closing means M9 is controlled to shut off the fuel flowing through the branch passage M6.

According to the above configuration, in addition to the same operation as the first invention, when the target pressure calculated by the first control means M10 becomes equal to or higher than a predetermined value, for example, when the internal combustion engine M3 is accelerated. When the amount of fuel required by the internal combustion engine M3 increases, as in the case of the second control means M11, the opening and closing means M9
To close the branch passage M6. Therefore, the fuel flowing through the branch passage M6 is shut off, and
Is no longer supplied with fuel, and all fuel discharged by the pump M2 is supplied to the internal combustion engine M3.

Accordingly, the amount of fuel supplied to the internal combustion engine M3 is increased by the amount flowing to the branch passage M6. Thus, even when the amount of fuel required for the internal combustion engine M3 increases, the pump M2 can supply a sufficient amount of fuel to the internal combustion engine M3.

[0014]

FIG. 2 is a block diagram showing an embodiment of a fuel supply system for an internal combustion engine according to the first and second aspects of the present invention.
This will be described in detail with reference to FIGS.

FIG. 2 is a schematic configuration diagram showing a fuel supply device of this embodiment. This device includes a fuel tank 11 storing fuel therein, an electric fuel pump 12 contained in the tank 11, a branch passage 13 for returning a part of the discharged fuel to the tank 11, and An electromagnetic valve 14 for opening and closing the branch passage 13, a jet pump 15 for generating a negative pressure by fuel flowing through the branch passage 13, and a communication passage 16 connected to the jet pump 15. Tank 1
1 has a saddle shape having a concave portion 17 in the center of the lower end, and has first and second storage chambers 18 and 19 separated from each other by the concave portion 17 on both left and right sides. Here, the first storage room 18
Constitutes a specific storage chamber of the present invention. Both storage rooms 18,1
Numerals 9 communicate with each other in a communication chamber 20 at the upper part of the concave portion 17. The tank 11 is attached to the vehicle so as to straddle the components of the drive system and the components of the exhaust system in the recess 17. Since the tank 11 has such a shape, when the fuel level is lower than the communication chamber 20, the fuel is stored in the first storage chamber 18 and the second storage chamber 19.
And divided into.

The pump 12 is supported on the tank 11 via a bracket (not shown). The pump 12 has a built-in DC motor (not shown) and an impeller (impeller: not shown) driven by the motor. When the motor is driven by the energization and the impeller is rotated, the pump 12 operates and the fuel in the tank 11 is sucked up by the pump 12 and discharged from the discharge port 21 thereof. The amount of fuel discharged from the pump 12 is determined based on the voltage value supplied to the motor, that is, the rotation speed of the impeller driven by the motor. The fuel pressure PF is determined by the amount of fuel discharged from the pump 12.

A fuel line 22 extending from a discharge port 21 of the pump 12 extends outside the tank 11 through an upper lid 23 of the tank 11. This line 22 is a fuel filter 2
4 and further connected to the delivery pipe 25. A plurality of injectors 26 provided on the delivery pipe 25 are arranged corresponding to each cylinder of an internal combustion engine (gasoline engine) 27. Each injector 26 is a nozzle with an electromagnetic valve, and opens when energized and closes when energized. Intake passage 2 connected to engine 27
8 guides air to each cylinder of the engine 27. Intake passage 2
The throttle valve 29 provided on the opening 8 selectively opens and closes the passage 28 by operating in conjunction with the operation of an accelerator pedal (not shown). By adjusting the opening degree (throttle opening degree) TA of the valve 29,
The amount of air (intake amount) Q to be taken into each cylinder of the engine 27 through the intake passage 28 is adjusted.

The fuel line 22 after the fuel filter 24
In the (branch portion 30), a branch passage 13 is provided for returning fuel to the first storage chamber 18. Branch passage 13
Jet pump 1 as a transfer means of the present invention
5 is provided, and the fuel flowing through the branch passage 13 is supplied to the pump 1
5 and is returned to the first storage chamber 18.

The jet pump 15 has a venturi passage 31 communicating with the branch passage 13 and a communicating portion 32 communicating with the passage 31 so as to be substantially perpendicular to the passage 31.
And a discharge port 33 for discharging fuel flowing through the venturi passage 31. The venturi passage 31 has, at its intermediate portion, a throttle portion 34 having a smaller flow passage cross-sectional area than the others. The flow of the fuel in the venturi passage 31 increases the flow velocity of the fuel in the throttle section 34, and generates a negative pressure in the throttle section 34. The communication passage 16 has one end connected to the communication portion 32 for transferring the fuel in the second storage chamber 19 into the first storage chamber 18. The other end of the communication passage 16 is arranged in a lower part in the second storage chamber 19.

The branch passage 13 is provided with an electromagnetic valve 14 as opening / closing means of the present invention, and the passage 13 is selectively opened and closed by controlling the electromagnetic valve 14. The solenoid valve 14 is connected to an electronic control unit (ECU) 50 which will be described later.
It is driven based on 50 signals. When the solenoid valve 14 is not energized, the branch passage 13 is opened by the solenoid valve 14. When the solenoid valve 14 is energized, the solenoid valve 14
Thereby, the branch passage 13 is closed.

When the fuel pump 12 operates, the fuel in the tank 11 is discharged to the fuel line 22. After the discharged fuel (discharged fuel) removes foreign matter by a filter 24, the discharged fuel is pressure-fed to a delivery pipe 25 through a fuel line 22, and is further distributed to each injector 26 in the delivery pipe 25. At this time, the fuel pressure PF in the delivery pipe 25 is adjusted according to the amount of fuel discharged from the pump 12. The distributed fuel is supplied to each corresponding cylinder by being injected from the injector 26 when the injector 26 is opened.
By burning a mixture of fuel and air supplied to each cylinder, a crankshaft (not shown) of the engine 27 is rotated, and power is obtained in the engine 27.

When the branch passage 13 is opened by the solenoid valve 14, a part of the fuel discharged by the pump 12 is supplied to the branch passage 13, and the fuel passes through the jet pump 15 to be stored in the first storage tank. It is returned to the room 18. At this time, the fuel flows through the throttle portion 34 of the venturi passage 31 to generate a negative pressure in the throttle portion 34. Second
The fuel stored in the storage chamber 19 is sucked into the venturi passage 31 through the communication passage 16 by the suction force of the negative pressure. The sucked fuel is discharged into the first storage chamber 18 together with the fuel flowing through the branch passage 13. When the branch passage 13 is closed by the solenoid valve 14, the fuel flowing through the passage 13 is shut off. Accordingly, the suction and discharge of the fuel by the jet pump 15 are stopped.

A drive circuit 40 for driving the pump 12
Supplies the electricity charged in the battery 41 to the motor of the pump 12. In this embodiment, the maximum voltage value that the battery 41 can supply to the motor is “12
V ". The drive circuit 40 adjusts a voltage value supplied to the pump 12.

A throttle sensor 45 provided near the throttle valve 29 detects the opening degree TA of the valve 29 and outputs a signal corresponding to the degree. The sensor 45 includes a well-known idle switch (not shown). This switch is turned on when the valve 29 is fully closed, and an idle signal ID indicating that the valve 29 is fully closed.
L is output. The fuel pressure sensor 46 provided in the delivery pipe 25 detects the pressure of the fuel pressure-fed to each injector 26, that is, the fuel pressure PF in the delivery pipe 25, and outputs a signal corresponding to the magnitude. Engine 27
Is provided with a rotational speed sensor 47 provided at the engine speed NE, that is, a rotational speed of a crankshaft (not shown).
Is detected, and a signal corresponding to the magnitude of the value is output. The sensor 47 intermittently detects the rotation of the crankshaft at predetermined angles in synchronization with the rotation phase of the crankshaft, and continuously outputs the detection result as a pulse signal. A water temperature sensor 48 provided in the engine 27 detects the temperature (cooling water temperature) THW of the cooling water flowing inside the engine 27, and outputs a signal corresponding to the magnitude. An intake pressure sensor 49 provided in the intake passage 28 detects an intake pressure PM in the passage 28,
A signal corresponding to the magnitude is output. Each of these sensors 4
5 to 49 constitute operating state detecting means.

The ECU 50 constitutes the first and second control means of the present invention. The ECU 50 has an input signal processing circuit, a memory, an arithmetic circuit, an output signal processing circuit, and the like. ECU
Reference numeral 50 denotes the various sensors 45 to 49, the solenoid valve 14,
The injector 26, the drive circuit 40, and the battery 41 are connected. The ECU 50 includes the various sensors 45 to 45 described above.
The signal output from 49 is input. The ECU 50 controls the solenoid valve 14, the injectors 26, and the drive circuit 40 to execute fuel injection control and fuel supply control based on these input signals.

The fuel injection control is to control the amount of fuel injected from each injector 26 to each cylinder by controlling the valve opening time of each injector 26 according to the operating state of the engine 27. The fuel supply control means controlling the drive circuit 40 in accordance with the operation state of the engine 27 and controlling the pump 12 to control the amount of fuel discharged from the pump 12, and thus the fuel supplied to each injector 26. Adjusting the pressure PF.

FIG. 3 is a flowchart showing a "fuel injection control routine" relating to the processing contents of the fuel injection control. The ECU 50 periodically executes this routine at predetermined intervals when the engine 27 is operating.

In step 100, the ECU 50 detects various sensors 45, 47 to 49,
7, various parameters reflecting the operation state TA, IDL,
The values related to NE, THW, and PM are read as input values.

In step 110, the ECU 50 determines whether or not the engine 27 is in a deceleration operation state. E
The CU 50 makes this determination based on the idle signal IDL. Here, the throttle valve 29 is fully closed,
When the engine 27 is in the deceleration operation state, the ECU 50 shifts the processing to step 120. Throttle valve 2
9 is opened and the engine 27 is not in the deceleration operation state,
The ECU 50 shifts the processing to step 140. In this embodiment, the ECU 50 that executes the process of step 110
Corresponds to a determination unit for determining whether or not the engine 27 is in a deceleration operation state.

During the deceleration operation of the engine 27, in step 120, the ECU 50 forcibly closes each injector 26 in order to forcibly stop fuel injection into each cylinder of the engine 27, that is, to perform fuel cut. I do. In this embodiment, the ECU 50 executing the processing of step 120 corresponds to a control unit for executing a fuel cut.

In step 130, the ECU 50
The fuel cut flag XFC is set to "1" to indicate that the fuel cut is being executed, and the subsequent processing is temporarily ended. In this embodiment, the ECU 50 executing the processing of step 130 corresponds to a setting unit for setting a flag indicating that the engine 27 is in the deceleration operation state.

When the engine 27 is not in the deceleration operation state,
In step 140, the ECU 50 sets the fuel cut flag X to indicate that the fuel cut has not been executed.
Set FC to "0". In this embodiment, step 1
The ECU 50 executing the processing of 40 corresponds to a setting unit for setting a flag indicating that the engine 27 is not in the deceleration operation state.

In step 150, the ECU 50 calculates the value of the basic injection amount TAUb based on the values of the engine speed NE and the intake pressure PM. This basic injection amount TA
Ub is a value in units of time. The ECU 50 calculates the value of the basic injection amount TAUb by referring to predetermined function data using the basic injection amount TAUb, the engine speed NE, and the intake pressure PM as parameters. In this embodiment, the ECU 50 that executes the processing of step 150
Corresponds to calculating means for calculating the basic injection amount TAUb to be basically set according to the operating state of the engine 27.

In step 160, the ECU 50 calculates the value of the temperature correction coefficient KTH based on the value of the cooling water temperature THW. The ECU 50 calculates the value of the temperature correction coefficient KTH by referring to predetermined function data using the temperature correction coefficient KTH and the coolant temperature THW as parameters. In this embodiment, the ECU 50 that executes the process of step 160 corresponds to a calculation unit that calculates a temperature correction coefficient KTH for correcting the basic injection amount TAUb according to the temperature state of the engine 27.

At step 170, the ECU 50 calculates the final value of the fuel injection amount TAU by multiplying the value of the basic injection amount TAUb by the temperature correction coefficient KTH. The fuel injection amount TAU is a value in units of time, and is a value that determines the valve opening time of the injector 26.
In this embodiment, an EC that executes the processing of step 170
U50 corresponds to a calculating means for calculating the final fuel injection amount TAU by correcting the basic injection amount TAUb with the temperature correction coefficient KTH.

In step 180, the ECU 50
It is determined whether fuel injection timing has come for each cylinder. The ECU 50 determines the arrival of the injection timing based on a pulse signal related to the engine speed NE.

When the injection timing has arrived, in step 190, the ECU 50 determines the calculated fuel injection amount T
Fuel injection is executed by opening each injector 26 for a required time based on the value of AU. After ending this processing, the ECU 50 once ends the subsequent processing.
In this embodiment, the ECU 50 executing the processing of steps 180 and 190 corresponds to an execution unit for executing fuel injection at a predetermined injection timing. Further, in this embodiment, the ECU 50 that executes the “fuel injection control routine” corresponds to control means for controlling the valve opening time of the injector 26.

FIG. 4 is a flowchart showing a "fuel supply control routine" relating to the processing contents of the fuel supply control. The ECU 50 periodically executes this routine at predetermined intervals when the engine 27 is operating.

In step 200, the ECU 50 reads, as input values, values relating to various parameters TA, PF, NE and PM detected by the various sensors 45 to 47 and 49. At the same time, the ECU 50 sets the fuel cut flag XF set in the aforementioned “fuel injection control routine”.
Read the value of C.

In step 210, the ECU 50 calculates the required amount of fuel TQE required for the engine 27 based on the various parameters TA, PF, NE, and PM read out. In this embodiment, the ECU 50 that executes the process of step 210 corresponds to a calculating unit for calculating the amount of fuel required of the engine 27 based on the operating state at that time.

In step 220, the ECU 50 calculates the target discharge amount TQF of the pump 12 by adding the branch fuel amount QJP for operating the jet pump 15 to the calculated required amount TQE. In this embodiment, the ECU 50 that executes the process of step 220 corresponds to a calculating unit that calculates a target discharge amount TQF to be discharged by the fuel pump 12.

In step 230, the ECU 50 determines whether or not the fuel cut flag XFC is "1". When the flag XFC is “1”, the ECU 50 shifts the processing to step 232 because the fuel cut has been performed and the engine 27 is in the deceleration operation state.
On the other hand, when the flag XFC is “0”, the fuel cut is not performed in the fuel injection control, and the engine 27 is in the steady operation or the accelerated operation.
The CU 50 shifts the processing to step 240.

If the fuel cut flag XFC is "1" in step 230, the fuel cut is performed in the fuel injection control, and the engine 27 is in the deceleration operation state.
N is set as the target fuel pressure TPF. This value PMI
N is the minimum fuel pressure required to flow fuel to the branch passage 13.

In step 234, the ECU 50 calculates the applied voltage VFP based on the target discharge amount TQF and the target fuel pressure TPF. At this time, since the fuel amount required for the engine 27 is “0”, the target discharge amount TQF
Is the branch fuel amount QJP.

In step 236, the ECU 50 opens the branch passage 13 by stopping the power supply to the solenoid valve 14 in order to flow the fuel to the branch passage 13. On the other hand, since the engine 27 is in the steady operation or the accelerated operation in step 240 after shifting from step 230, the ECU 50 determines the engine rotational speed NE and the intake pressure P.
The target fuel pressure TPF at the time of fuel injection is calculated based on the value of M. The ECU 50 compares the target fuel pressure TPF with the target fuel pressure TPF, the engine rotational speed NE, and the intake pressure P.
It is calculated with reference to predetermined function data using M as a parameter. In this embodiment, the ECU 50 that executes the process of step 240 corresponds to a calculating unit for calculating the target fuel pressure TPF during fuel injection.

At step 250, the ECU 50
Based on the target discharge amount TQF calculated in steps 220 and 240 and the target fuel pressure TPF, the ECU 50
Calculates the applied voltage VFP to be supplied to the pump 12 by referring to function data defined using the target discharge amount TQF and the target fuel pressure TPF as parameters, as shown in the graph of FIG. When the applied voltage VFP is applied to the fuel pump 12, the fuel pump 12
Discharges a fuel amount substantially matching the target discharge amount TQF.
The actual fuel pressure PF at this time is substantially proportional to the actual discharge amount QF of the fuel pump 12.

In the graph of FIG. 5, the horizontal axis represents the target fuel pressure TPF, the vertical axis represents the target discharge amount TQF, and the relationship between the two parameters TPF and TQF and the applied voltage VFP is represented by a straight line falling to the right. In this graph, the value of the applied voltage VFP increases as the target fuel pressure TPF and the target discharge amount TQF both increase. In other words, in this step 250, the target fuel pressure TPF
And the applied voltage VFP required to drive the fuel pump 12 so as to obtain the target discharge amount TQF.
Here, since the maximum voltage of the battery 41 is “12 V”, the maximum value of the applied voltage VFP is “12 V”.
Therefore, in the graph, the value of the applied voltage VFP is “12”.
V "or more (region shown by oblique lines rising to the right)
Indicates a region where the target fuel pressure TPF and the target discharge amount TQF are not set. The upper limits of the target fuel pressure TPF and the target discharge amount TQF are set based on the performance of the fuel pump 12 used.

As described above, the branch fuel amount QJP is the amount of fuel flowing to the branch passage 13 when the solenoid valve 14 is open. For example, when the target discharge amount TQF is a predetermined value TQF
When the value is 1, the branch fuel amount QJP is supplied to the branch passage 13 when the electromagnetic valve 14 is open, and the amount (TQF1-QJ) obtained by subtracting the value of the branch fuel amount QJP from the predetermined value TQF1.
P) is supplied to the fuel line 22. In the above case, when the electromagnetic valve 14 is closed, the fuel flowing to the branch passage 13 is shut off, and all the fuel corresponding to the predetermined value TQF1 is supplied to the fuel line 22.

The target fuel pressure TPF and the target discharge amount TQF
Are respectively predetermined values TPF1 and TQF1, and FIG.
As indicated by broken lines in FIG.
1, the applied voltage VFP is determined to be "10 V" based on TQF1. Thus, the value of the applied voltage VFP is calculated based on the target discharge amount TQF and the target fuel pressure TPF. In this embodiment, the ECU 50 executing the process of step 250 determines whether the applied voltage VF applied to the fuel pump 12
It corresponds to a calculating means for calculating P.

In step 260, the ECU 50 determines whether the calculated value of the applied voltage VFP is larger than a predetermined value VFP1. If the calculated value of applied voltage VFP is larger than predetermined value VFP1, ECU 50 shifts the processing to step 270, and calculates calculated applied voltage VFP.
Is less than or equal to predetermined value VFP1, ECU 50 shifts the processing to step 236. As shown in FIG. 5, in this embodiment, the predetermined value VFP1 is set to “11.5V”. The predetermined value VFP1 can be arbitrarily changed according to the performance of the fuel pump 12. When the applied voltage VFP is smaller than the predetermined value VFP1, the amount of fuel required for the engine 27 is relatively small. In this case, the fuel discharged from the fuel pump 12 is added to the fuel line 22 and also flows to the branch passage 13. On the other hand, when the applied voltage VFP is equal to or higher than the predetermined value VFP1, the amount of fuel required for the engine 27 is relatively large. For this reason, it is necessary to supply all the fuel discharged from the fuel pump 12 to the fuel line 22. However, assuming that the fuel pump 12 is driven to the maximum and the maximum amount of fuel is discharged, a part of the fuel flows to the branch passage 13 to reliably supply the required amount of fuel to the engine 27. May not be possible. The predetermined value VFP1 is a value representing an upper limit value at which the fuel pump 12 can reliably supply the required fuel amount to both the fuel line 22 and the branch passage 13. ECU that performs the process of step 250
Reference numeral 50 corresponds to a determination unit that determines whether the calculated applied voltage VFP is higher than a predetermined value VFP1.

Shifting from step 260 to step 27
At zero, the ECU 50 closes the branch passage 13 by energizing the solenoid valve 14 in order to shut off the fuel flowing to the branch passage 13.

On the other hand, in step 236 after step 260, the ECU 50 stops the energization of the solenoid valve 14 to open the branch passage 13. Step 28 after shifting from steps 236 and 270
At 0, the ECU 50 drives the fuel pump 12 based on the calculated applied voltage VFP.

In step 290, the ECU 50
It is determined whether or not the value of the detected actual fuel pressure PF is the same as the calculated target fuel pressure TPF. Both P
If F and TPF are the same, the ECU 50 temporarily ends the subsequent processing. If the PF and TPF are different, the ECU 5
If "0", the process proceeds to step 282.

In step 292, the ECU 50 determines whether the actual value of the fuel pressure PF is higher than the target fuel pressure TPF. The fuel pressure PF is equal to the target fuel pressure TP
If F is smaller than F, then in step 294, the ECU
Numeral 50 controls the drive circuit 40 to increase the applied voltage VFP supplied to the pump 12, thereby increasing the fuel amount QF discharged from the pump 12. After that, the ECU 5
0 returns the process to step 280.

If it is determined in step 292 that the fuel pressure PF is higher than the target fuel pressure TPF, step 296 is executed.
In, the ECU 50 controls the drive circuit 40 to reduce the applied voltage VFP supplied to the pump 12, thereby reducing the fuel amount QF discharged from the pump 12. Thereafter, the ECU 50 returns the processing to step 280. That is, in steps 280 to 296, the ECU 5
0 controls the amount of fuel discharged from the pump 12 so that the actual value of the fuel pressure PF matches the calculated target fuel pressure TPF. In this embodiment, steps 234 and 25
The ECU 50 executing the processes of 0,280 to 296 corresponds to a first control unit of the present invention. Also, in this embodiment,
EC for executing the processing of steps 236, 260, and 270
U50 corresponds to the second control means of the present invention.

As described above, according to the configuration of this embodiment, when fuel is stored in the first and second storage chambers 18 and 19, the fuel in the first storage chamber 18 is supplied to the pump 1
2 to each injector 26, and fuel is injected from each injector 26, thereby
Is supplied to each of the cylinders.

Here, in the fuel injection control, the ECU
Reference numeral 50 denotes various parameters N relating to the operating state of the engine 27.
Based on the values of E, PM, THW, etc., the value of the fuel injection amount TAU required for operating the engine 27 is calculated. ECU50
Controls the amount of fuel to be injected into each cylinder by controlling each injector 26 based on the calculated value of the fuel injection amount TAU. The ECU 50 calculates the fuel injection amount TAU as the valve opening time of each injector 26. Therefore, the ECU 50 controls each injector 26 to control the amount of fuel injected from each injector 26.
Adjust the valve opening time.

In controlling the fuel supply, the ECU 50 determines various parameters NE and PM relating to the operating state of the engine 27.
The target fuel pressure TPF to be supplied to each injector 26 is calculated based on the value of. The ECU 50 controls the amount of fuel discharged from the pump 12 by controlling the drive circuit 40 so that the actual value of the fuel pressure PF detected by the fuel pressure sensor 46 matches the calculated target fuel pressure TPF. I do.

As described above, the amount of fuel supplied to each cylinder from each injector 26 is determined by the cooperation between the adjustment of the fuel pressure PF supplied to each injector 26 and the adjustment of the valve opening time of each injector 26. It is adjusted according to the operating state of the engine 27.

When the branch passage 13 is opened by the solenoid valve 14, part of the fuel discharged by the fuel pump 12 is supplied to the branch passage 13. The fuel pressure PF required by the engine 27 during steady operation and deceleration operation is lower than the fuel pressure PF required by the engine 27 during acceleration operation. For this reason, during steady operation and deceleration operation,
Even if a part of the fuel discharged from the fuel pump 12 is supplied to the branch passage 13, the fuel pressure PF supplied to the injector 26 does not become insufficient. Here, the ECU 50 calculates a target discharge amount TQF and a target fuel pressure TPF to be discharged by the fuel pump 12 based on the detected parameters NE, PM, and TA. The ECU 50 sets both parameters TQ
The voltage V supplied to the fuel pump 12 according to F and TPF
Calculate FP. The ECU 50 calculates the applied voltage VF
The branch passage 13 is opened and closed based on the size of P. That is,
The ECU 50 determines that the calculated applied voltage VFP is equal to a predetermined value VFP.
If it is larger than 1, the electromagnetic valve 14 is controlled to close the branch passage 13, and the calculated applied voltage VFP becomes the predetermined value VFP.
If it is less than or equal to 1, the electromagnetic valve 14 is controlled to
Open 3. When the branch passage 13 is closed by the solenoid valve 14, all the fuel QF discharged by the fuel pump 12 is supplied to the injector 26.

Accordingly, in the steady operation state and the deceleration operation state where the fuel amount TQE required by the injector 26 is relatively small (these operation states occur at a rate of 80% or more of the entire operation state), the branch passage. 13 is opened, and fuel is supplied to the passage 13. On the other hand, in the accelerated operation state where the fuel amount TQE required by the injector 26 is relatively large (this operation state occurs at a rate of less than 20% of the entire operation state), the branch passage 13 is closed. Thus, no fuel is supplied to the passage 13. As a result, the fuel amount QE supplied to the injector 26 is increased. At this time, the fuel amount QE supplied to the injector 26 temporarily exceeds the target fuel amount TQE, but the actual fuel pressure PF is reduced by the feedback control to the target fuel pressure TQE.
It is controlled to be PF. As a result, in the acceleration operation state, a sufficient amount of fuel is supplied to the injector 26. As described above, by opening and closing the branch passage 13 by the electromagnetic valve 14, the ECU 50 adjusts the amount of fuel flowing to the injector 26 and the branch passage 13.

Here, when the fuel flows through the branch passage 13, a negative pressure is generated in the jet pump 15. More specifically, as the flow velocity of the fuel increases in the throttle portion 34 in the venturi passage 31, a negative pressure is generated in the throttle portion 34. By the suction force of this negative pressure, the jet pump 15
The fuel stored in the second storage chamber 19 is sucked through the communication passage 16 and discharged to the first storage chamber 18. The transferred fuel is supplied to the injector 26 by the fuel pump 12.

In this embodiment, all the fuel stored in the second storage chamber 19 is transferred to the first storage chamber 18 by the jet pump 15 and supplied to the injector 26. Therefore, all the fuel stored in the storage chambers 18 and 19 can be supplied to the injector 26. As a result, the fuel supply device according to the present embodiment, in which the fuel pressure PF is controlled in accordance with the operating state of the engine 27, is connected to the saddle-shaped fuel tank 11 (the plurality of storage chambers 18, 1).
9) can be applied.

In this embodiment, the branch passage 13 is opened and closed based on the operating state of the engine 27, that is, based on the magnitude of the calculated applied voltage VFP. Therefore, when there is a margin in the discharge capacity of the fuel pump 12 as in the steady operation state and the deceleration operation state of the engine 27, the jet pump 15 is operated by supplying the fuel to the branch passage 13, and A transfer can take place. On the other hand, when the amount of fuel to be supplied to the injector 26 is relatively large, such as in the acceleration operation state of the engine 27,
By closing the branch passage 13, the amount of fuel supplied to the fuel line 22 can be increased. As a result, an optimal fuel amount can be supplied to the injector 26 according to the operating state of the engine 27. In the accelerated state of the engine 27, the transfer of fuel by the jet pump 15 is not performed, but such a state is for a short period of time and does not hinder the transfer of fuel from the second storage chamber 19. .

In this embodiment, the fuel pump 12 is always driven even when the fuel cut is being performed, and the fuel pump 12 sucks and discharges the fuel. Therefore, fuel always flows into the fuel pump 12 during operation of the engine 27, and the pump 12 is cooled by the flowing fuel. As a result, heat generation of the fuel pump 12 is suppressed, and generation of vapor in the fuel can be prevented. In this embodiment, while the fuel cut is being performed, the fuel pressure PF is set to the minimum fuel pressure PFMIN for flowing the fuel to the branch passage 13. For this reason,
The amount of fuel discharged by the pump 12 is minimized,
2 can save power consumption.

In this embodiment, the length of the branch passage 13 is from the branch 30 after the fuel filter 24 to the jet pump 15 in the first storage chamber 18, and the length of the tank 1
1 is stored. Therefore, the branch passage 13 is shorter than the conventional return passage (having a length from the delivery pipe to the fuel tank). For this reason, the configuration of the fuel supply device can be simplified.

The present invention can be embodied in another embodiment as follows. In the following another embodiment, the same operation and effect as the above embodiment can be obtained. (1) In the above embodiment, one fuel tank 11 is saddle-shaped and includes two storage chambers 18 and 19. On the other hand, a plurality of fuel tanks separated from each other may be used. For example, when two fuel tanks are used, one fuel tank is provided with a fuel pump and a jet pump, and the other fuel tank is opened with a communication passage communicating with the jet pump. Further, one fuel tank may include three or more storage chambers. In this case, a fuel pump and a jet pump are provided in one storage chamber, and a communication passage communicating with the jet pump is opened in each of the other storage chambers.

(2) In the above embodiment, the negative pressure generated by the fuel flowing through the jet pump 15 causes
The fuel in the second storage chamber 19 was transferred. On the contrary,
Another configuration may be used as long as the configuration is such that the fuel is transferred using the action force of the fuel flowing through the branch passage 13. For example, in this case, it is conceivable to provide a mechanism for converting the energy (potential energy and kinetic energy) of the fuel flowing through the branch passage 13 into a suction force for transferring the fuel.

(3) In the above embodiment, as shown in FIG. 5, the predetermined value VFP1 relating to the applied voltage used for controlling the opening and closing of the branch passage 13 is set to "11.5V".
On the other hand, the predetermined value VFP1 may be arbitrarily set according to the performance of the fuel pump 12. For example, when the maximum discharge amount of the fuel pump 12 is relatively small, the predetermined value VFP1 is set to be smaller than “11.5 V”. When the maximum discharge amount of the fuel pump 12 is relatively large, the predetermined value VFP1 is set. May be set higher than “11.5 V”.

(4) In the above embodiment, the ECU 50 controls the electromagnetic valve 14 to selectively open and close the branch passage 13. On the other hand, the opening degree of the solenoid valve 14 may be adjusted according to the operation state of the engine 27, and the amount of branch fuel QJP flowing through the branch passage 13 may be variable. In this case, the amount of fuel flowing to the fuel line 22 and the branch passage 13 can be adjusted to be optimal according to the operating state of the engine 27.

Further, technical ideas other than the claims that can be grasped from the above embodiment will be described below together with their effects. (A) In the fuel supply device for an internal combustion engine according to claim 1 or 2, the second control means controls the opening / closing means while the supply of fuel to the internal combustion engine is stopped, and the branching is performed. A fuel supply device for an internal combustion engine, wherein a passage is opened, and the first control means controls the pump so as to discharge fuel flowing to the branch passage.

According to this configuration, even when the fuel supply to the internal combustion engine is stopped, the fuel pump is driven, and the fuel flows to the branch passage. Therefore, even when the fuel supply to the internal combustion engine is stopped, fuel flows into the fuel pump,
The fuel pump is cooled by the flowing fuel. As a result, heat generation of the fuel pump is suppressed, and generation of vapor in the fuel can be prevented.

[0073]

According to the first aspect of the present invention,
The tank includes a plurality of storage chambers, and a pump is arranged in one of the specific storage chambers, and a part of the fuel discharged in the specific storage chamber is returned to the specific storage chamber through a branch passage, and the specific storage chamber is provided with a pump. The storage chamber other than the storage chamber and the branch passage communicate with each other through a communication path, the transfer means transfers fuel to a specific storage chamber through the communication path by suction force, and the opening and closing means opens and closes the branch passage. .

Therefore, when the branch passage is opened by the opening / closing means, a part of the fuel discharged by the pump flows to the branch passage. By the transfer means, the fuel in the storage chamber other than the specific storage chamber is transferred to the specific storage chamber through the communication passage. The transferred fuel is supplied to the internal combustion engine by a pump. Therefore, the fuel stored in the plurality of storage chambers can be supplied to the internal combustion engine by one fuel pump.

According to the second aspect of the present invention, the second control means shuts off the fuel flowing through the branch passage when the target pressure in the first control means becomes equal to or higher than a predetermined value. Therefore, the opening and closing means are controlled.

Therefore, when the target pressure becomes high, such as during the acceleration operation of the internal combustion engine, the opening / closing means closes the branch passage. As a result, the amount of fuel supplied to the internal combustion engine is increased by the amount of fuel flowing into the branch passage. As a result, when the fuel pressure required for the internal combustion engine increases, an effect that a sufficient fuel pressure can be supplied to the internal combustion engine is exhibited.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram conceptually showing configurations of first and second inventions.

FIG. 2 is a configuration diagram showing a configuration of a fuel supply device.

FIG. 3 is a flowchart illustrating a “fuel injection control routine”.

FIG. 4 is a flowchart showing a “fuel supply control routine”.

FIG. 5 is a graph showing a relationship between a fuel pressure, a pump discharge amount, and a pump applied voltage.

FIG. 6 is a configuration diagram illustrating an example of a fuel supply device including a conventional saddle-shaped tank.

FIG. 7 is a configuration diagram showing an example of a conventional fuel supply device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Fuel tank, 12 ... Fuel pump, 13 ... Branch passage, 14 ... Solenoid valve as opening / closing means, 15 ... Jet pump as transfer means, 16 ... Communication passage, 18 ... First storage as specific storage chamber Room 19, second storage room 27
... gasoline engine as internal combustion engine, 50 ... ECU
(50 constitutes first and second control means.)

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ identification code FI F02M 37/00 331 F02M 37/00 331D 37/20 37/20 U (58) Investigated field (Int.Cl. ⁷ , DB name ) F02M 37/08 F02M 37/00 301 F02M 37/00 311 F02M 37/00 331 F02M 37/20

Claims (2)

(57) [Claims] 1. A fuel supply device which discharges fuel in a tank by a pump and adjusts a fuel pressure supplied to an internal combustion engine by controlling the pump, wherein the tank comprises a plurality of tanks. Including a storage chamber, wherein the pump is arranged for one specific storage chamber, and for returning a part of fuel discharged from the pump in the specific storage chamber to the specific storage chamber. A branch passage, a communication passage for communicating a storage chamber other than the specific storage chamber and the branch passage with each other, and a fuel in a storage chamber other than the specific storage chamber by an action force of fuel flowing through the branch passage. Transfer means for transferring the fuel to the specific storage chamber through the communication passage; opening and closing means provided in the branch passage for opening and closing the passage; and a fuel pressure supplied to the internal combustion engine. First control means for controlling the pump so as to have a target pressure corresponding to the operation state of the fuel engine; and for shutting off fuel flowing from the pump to the branch passage in accordance with the operation state of the internal combustion engine. And a second control unit for controlling the opening / closing unit. 2. The fuel supply device for an internal combustion engine according to claim 1, wherein the second control unit is configured to control the branch passage when the target pressure in the first control unit becomes equal to or higher than a predetermined value. A fuel supply device for an internal combustion engine, wherein the opening / closing means is controlled to shut off fuel flowing through the fuel cell.