JP2013060091A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve energy efficiency of a vehicle by effectively using the surplus electricity in a vehicle in which the electric power collected by an electric power regeneration device is saved in the battery.SOLUTION: When the state of charges of the battery is higher than the set value (step S201), and the electric power regeneration device collects the surplus electric power (step S202), the pressure of the fuel that the fuel supply device supplies to an internal combustion engine is raised by using the surplus electric power (step S203). The state whose fuel pressure is raised higher than the target is generated, and the power consumption in the fuel supply device decreases, immediately after the pressure of the fuel is raised by using the surplus electricity.

Description

  The present invention relates to a vehicle control device that stores, in a battery, electric power collected by a power regeneration device.

  Conventionally, in a hybrid vehicle, the electric power collected by the power regeneration device is stored in a high voltage battery for traveling, while the high voltage of the high voltage battery is converted to a low voltage by a DC-DC converter to charge the auxiliary battery. (For example, refer to Patent Document 1).

JP 2010-036594 A

  By the way, in a vehicle that stores the regenerated power in the battery, if the state of charge of the battery exceeds the set value and the state where charging is unnecessary (full charge state), even if excess power exceeding the power consumption is recovered In the past, there was room for further improvement in energy efficiency, such as stopping regeneration for surplus or discharging the recovered surplus power.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle control device that can effectively use surplus power and improve the energy efficiency of the vehicle.

  Therefore, in the present invention, when the state of charge of the battery that stores the power collected by the power regeneration device is higher than a set value and the power regeneration device collects surplus power, fuel is supplied using the surplus power. The pressure of the fuel supplied by the device to the internal combustion engine was increased.

  According to the above invention, the fuel pressure is increased by using the surplus power, so that the power consumption in the subsequent fuel supply device can be reduced and the energy efficiency in the vehicle can be improved.

1 is a system diagram of a hybrid vehicle in an embodiment of the present invention. 1 is a system diagram of an engine in an embodiment of the present invention. It is a flowchart which shows 1st Embodiment of fuel pump control using the regenerative energy in embodiment of this invention. It is a diagram which shows the characteristic of the target fuel pressure in the high fuel pressure mode in the said 1st Embodiment. It is a time chart for demonstrating the control characteristic of the said 1st Embodiment. It is a flowchart which shows 2nd Embodiment of fuel pump control using the regenerative energy in embodiment of this invention. It is a time chart for demonstrating the control characteristic of the said 2nd Embodiment. It is a flowchart which shows 3rd Embodiment of fuel pump control using the regenerative energy in embodiment of this invention. It is a time chart for demonstrating the control characteristic of the said 3rd Embodiment.

Embodiments of a vehicle control apparatus according to the present invention will be described below.
FIG. 1 is a diagram illustrating a system configuration of a hybrid vehicle in the embodiment.
A hybrid vehicle 101 shown in FIG. 1 includes an engine (internal combustion engine) 102 and an electric motor (AC motor) 103 as a driving source for vehicle travel.

The electric motor 103 is a motor M / generator G. When the electric motor 103 operates as an electric motor, it outputs a driving force for driving the vehicle, and operates as a generator by being rotationally driven by the engine 102 and driving wheels 105 and 105. And output power.
The driving forces of the engine 102 and the electric motor 103 are transmitted to the drive wheels 105 and 105 via the power split mechanism 104 and a reduction mechanism not shown.

Further, the power split mechanism 104 transmits the power of the engine 102 to the electric motor 103, and further transmits the kinetic energy from the speed reduction mechanism to the electric motor 103 during braking so that the electric motor 103 operates as a generator.
The inverter 106 converts the DC power stored in the high-voltage battery 107 for traveling into AC power and supplies the AC power to the electric motor 103. Also, during regenerative braking or power generation, the inverter 106 outputs AC power output from the electric motor 103 to DC. It converts into electric power and charges the high voltage battery 107 (for example, 200V battery).

Further, the DC-DC converter 108 converts the high voltage of the high-voltage battery 107 into a low voltage, supplies power to a low-voltage load 109 (for example, a fuel pump 12 to be described later), and low voltage for auxiliary equipment. A battery 110 (for example, a 12V battery) is charged.
Here, the output of the DC-DC converter 108 is controlled by the converter control circuit built in the DC-DC converter 108 so that the terminal voltage of the low-voltage battery 110 becomes constant.

A hybrid control module (HVCM) 111 with a built-in computer inputs signals such as an accelerator opening and a shift position, and calculates an engine output request value, a motor output request value, and the like according to an operating state.
Here, the HVCM 111 operates as a generator by rotating the electric motor 103 with the power transmitted from the drive wheels 105 and 105 when the vehicle is decelerated (when the accelerator is OFF), and converts the kinetic energy of the vehicle into electric energy. Then, power regeneration (regenerative braking), which is recovered by the high voltage battery 107 via the inverter 106, is performed.
Accordingly, the HVCM 111, the electric motor 103, the inverter 106, and the like constitute a power regeneration device.

An engine control module (ECM) 112 having a built-in computer controls the output of the engine 102 in accordance with an engine output request value output from the HVCM 111.
Also, a brake control module (BCM) 113 with a built-in computer calculates a regenerative request value of the electric motor 103 and outputs it to the HVCM 111. Also, the braking force of the hydraulic brake device 114 according to the actual amount of regenerative energy. To control.

Further, the battery monitoring module (BMM) 115 with a built-in computer calculates an SOC (State Of Charge) indicating a charging state (remaining capacity ratio) of the high voltage battery 107 from the current value and voltage value of the high voltage battery 107. And output to the HVCM 111.
SOC = {remaining capacity (Ah) / full charge capacity (Ah)} × 100

As described above, the state of charge SOC is calculated to be larger as the high voltage battery 107 is closer to full charge (charge completion state).
The HVCM 111 controls energy regeneration during deceleration based on the state of charge SOC output from the BMM 115, and controls engine output to charge the high voltage battery 107.

FIG. 2 is a system diagram of the engine 102.
In FIG. 2, the engine 102 includes a fuel injection valve 3 in the intake passage 2, and the fuel injection valve 3 injects fuel into the intake passage 2 of the engine 102.

The fuel injected by the fuel injection valve 3 is sucked into the combustion chamber 5 together with air through the intake valve 4 and ignited and burned by spark ignition by the spark plug 6. The combustion gas in the combustion chamber 5 is discharged to the exhaust passage 8 through the exhaust valve 7.
An electronically controlled throttle 10 that is opened and closed by a throttle motor 9 is disposed upstream of the portion of the intake passage 2 where the fuel injection valve 3 is disposed, and the intake air amount (output) of the engine 102 is determined by the opening of the electronically controlled throttle 10. ).

The engine 102 also includes a fuel supply device 13 that pumps the fuel in the fuel tank 11 to the fuel injection valve 3 by the fuel pump 12.
The fuel supply device 13 includes a fuel tank 11, a fuel pump 12, a pressure regulator (pressure regulating valve) 14, an orifice 15, a fuel gallery pipe 16, a fuel supply pipe 17, a fuel return pipe 18, a jet pump 19, and a fuel transfer pipe 20. Including.

The fuel pump 12 is an electric pump that rotationally drives a pump impeller with a motor, and is provided in the fuel tank 11.
One end of the fuel supply pipe 17 is connected to the discharge port of the fuel pump 12, the other end of the fuel supply pipe 17 is connected to the fuel gallery pipe 16, and the fuel supply port of the fuel injection valve 3 is connected to the fuel gallery pipe 16. Connected.

The fuel return pipe 18 is branched from the fuel supply pipe 17 in the fuel tank 11, and the other end of the fuel return pipe 18 is opened in the fuel tank 11.
The fuel return pipe 18 is provided with a pressure regulator 14, an orifice 15, and a jet pump 19 in this order from the upstream side.

The pressure regulator 14 includes a valve body 14 a that opens and closes the fuel return pipe 18 and an elastic member 14 b such as a coil spring that presses the valve body 14 a toward the valve seat upstream of the fuel return pipe 18.
The pressure regulator 14 opens when the fuel pressure FUPR supplied to the fuel injection valve 3 is higher than the set pressure (valve opening pressure), and causes the fuel in the fuel supply pipe 17 to pass through the fuel return pipe 18. Relief in the fuel tank 11 causes the fuel pressure FUPR to decrease toward the set pressure, and the valve closes when the fuel pressure FUPR falls below the set pressure.

As described above, the pressure regulator 14 opens when the fuel pressure FUPR becomes higher than the set pressure, but the orifice 15 provided on the downstream side of the pressure regulator 14 enters the fuel tank 11 via the fuel return pipe 18. The returned fuel flow is throttled. For this reason, the fuel pressure FUPR can be increased to a pressure exceeding the set pressure by increasing the amount of fuel discharged from the fuel pump 12 beyond the return flow rate.
Note that the amount of fuel (relief flow rate) returned to the fuel tank 11 by the fuel return pipe 18 is reduced to such an extent that the fuel pressure can be increased to the fuel pressure FUPR exceeding the set pressure of the pressure regulator 14 by controlling the discharge amount of the fuel pump 12. For example, the pressure regulator 14 can have a function of reducing the flow rate (relief flow rate) without providing the orifice 15.

The jet pump 19 transfers the fuel through the fuel transfer pipe 20 by the flow of fuel returned into the fuel tank 11 through the pressure regulator 14 and the orifice 15.
The fuel tank 11 is a so-called saddle type fuel tank in which a part of the bottom surface is raised and the bottom space is divided into two regions 11a and 11b, and the suction port of the fuel pump 12 opens into the region 11a. If the fuel in the region 11b is not transferred to the region 11a side, the fuel in the region 11b will remain.

Therefore, the jet pump 19 applies a negative pressure to the fuel transfer pipe 20 by the flow of fuel returned into the region 11a of the fuel tank 11 through the pressure regulator 14 and the orifice 15, and the fuel transfer pipe 20 opens. The fuel in the region 11 b is guided to the jet pump 19 through the fuel transfer pipe 20 and discharged into the region 11 a together with the return fuel from the pressure regulator 14.
In the present embodiment, the jet pump 19 is provided as described above. However, when the fuel tank 11 is not a so-called saddle type, that is, the bottom space of the fuel tank 11 is not separated, the fuel is supplied from the suction port of the fuel pump 12. When the fuel in the tank 11 can be sucked without remaining, the jet pump 19 and the fuel transfer pipe 20 can be omitted.
Alternatively, a fuel supply device that does not include the fuel return pipe 18, the pressure regulator 14, the orifice 15, and the jet pump 19 may be used.

The ECM 112 controls fuel injection by the fuel injection valve 3, ignition by the spark plug 6 (energization to the ignition coil), and controls the opening degree of the electronic control throttle 10 according to the engine output request value output from the HVCM 111. Control.
A fuel control module (FCM) 30 including a computer includes a drive circuit (transistor circuit for turning on and off the motor current) of the fuel pump 12 and controls power supply to the fuel pump 12.

The ECM 112 and the FCM 30 are configured to be able to communicate with each other, and the ECM 112 transmits a signal indicating a drive duty (operation amount) of the fuel pump 12 to the FCM 30.
The drive duty (%) of the fuel pump 12 is an operation amount for controlling the voltage of the motor that rotationally drives the fuel pump 12, and indicates the energization time ratio (on-time ratio) per cycle, and the drive duty increases. As a result, the average applied voltage of the motor increases, and the discharge pressure (discharge flow rate) of the fuel pump 12 increases.

The ECM 112 inputs signals output from various sensors.
Examples of the various sensors include a fuel pressure sensor 33 that detects the fuel pressure FUPR in the fuel gallery pipe 16, an accelerator opening sensor 34 that detects an accelerator pedal depression amount (accelerator opening) ACC (not shown), and intake air of the engine 102 An air flow sensor 35 for detecting the flow rate QA, a rotation sensor 36 for detecting the rotational speed NE of the engine 102, a water temperature sensor 37 for detecting the cooling water temperature TW (engine temperature) of the engine 102, and the engine 102 according to the oxygen concentration in the exhaust gas. An air-fuel ratio sensor 38 for detecting the air-fuel ratio A / F is provided.

The ECM 112 calculates the basic injection pulse width TP based on the intake air flow rate QA and the engine speed NE, and corrects the basic injection pulse width TP in accordance with the fuel pressure FUPR at that time, while the air-fuel ratio sensor 38. An air-fuel ratio feedback correction coefficient LAMBDA for approximating the actual air-fuel ratio to the target air-fuel ratio based on the output of the engine is calculated, and the basic injection pulse width TP corrected according to the fuel pressure FUPR is further calculated. Then, the final injection pulse width TI is calculated.
At the injection timing of each cylinder, an injection pulse signal having an injection pulse width TI is output to the fuel injection valve 3 to control the fuel injection amount and the injection timing by the fuel injection valve 3.

Further, the ECM 112 calculates the ignition timing (ignition advance value) based on the basic injection pulse width TP indicating the load of the engine 102, the engine speed NE, and the like, and spark discharge is performed by the spark plug 6 at the ignition timing. In this manner, the energization to the ignition coil (not shown) is controlled.
Further, the ECM 112 calculates the target opening degree of the electronic control throttle 10 from the engine output request value output from the HVCM 111 and energizes the throttle motor 9 so that the actual opening degree of the electronic control throttle 10 approaches the target opening degree. Control.

Further, the ECM 112 calculates the target calculated according to the fuel pressure FUPR detected by the fuel pressure sensor 33 and the operating conditions of the engine 102 (engine start, cooling water temperature TW, acceleration, engine load, engine speed, engine stop, etc.). Based on the fuel pressure TGFUPR, the drive duty DUTY (target applied voltage) of the fuel pump 12 is calculated so that the actual fuel pressure FUPR approaches the target fuel pressure TGFUPR, and a signal indicating this drive duty DUTY (%) is transmitted to the FCM 30. To do.
The drive duty can be calculated as the sum of a feedback amount calculated based on a deviation between the target fuel pressure TGFUPR and the actual fuel pressure FUPR and a basic amount corresponding to the target fuel pressure TGFUPR.

Then, the FCM 30 performs duty control on the drive circuit (transistor for turning on and off the motor current) of the fuel pump 12 based on the instruction signal of the drive duty DUTY received from the ECM 112 side, and controls power supply to the fuel pump 12. .
The low voltage battery 110 is connected to the FCM 30 via a power relay (pump relay) 43, and the drive circuit built in the FCM 30 supplies power to the low voltage battery 110 connected via the power relay 43. Then, power is supplied to the fuel pump 12. On / off of the power relay 43 is controlled by the ECM 112.

Thus, the fuel pump 12 is a low-pressure load 109 that receives power supply from the low-voltage battery 110. The low-pressure load 109 includes the fuel injection valve 3 and the control module 112, 30, 111, 113, 115, and the like.
As described above, the ECM 112 and the FCM 30 drive the fuel pump 12 using the low-voltage battery 110 as a power source so that the actual fuel pressure FUPR approaches the target fuel pressure TGFUPR. In this embodiment, the fuel pump 12 is controlled. In order to effectively use regenerative energy, control is added.

Hereinafter, control (drive control means) of the fuel pump 12 for effectively using the regenerative energy will be described with reference to the flowchart of FIG.
The routine shown in the flowchart of FIG. 3 is a routine executed by the ECM 112 that has obtained information about the state of charge and the amount of energy recovered by regenerative braking from the HVCM 111. However, the HVCM 111 can execute the routine shown in the flowchart of FIG. 3 and output an instruction to the ECM 112.

First, in step S201, it is determined whether or not the SOC indicating the charging state of the high voltage battery 107 is higher than the set value SLSOC (whether or not the high voltage battery 107 is fully charged).
The set value SLSOC is a threshold value for determining whether or not the charging of the high voltage battery 107 is substantially completed, and further electric power cannot be recovered, and the charging state SOC at that time is When the value is higher than the set value SLSOC, it indicates that charging of the high voltage battery 107 is substantially completed, and further power cannot be recovered. In other words, the set value SLSOC is a lower limit value of the state of charge SOC that is determined as not requiring charging.

When the state of charge SOC is lower than the set value SLSOC, the charging of the high voltage battery 107 is not completed, the charging of the high voltage battery 107 is necessary, and the electric motor 103 is operated as a generator during deceleration. The surplus energy (surplus power) excluding the consumed energy at that time from the collected electric energy (regenerative power) can be stored in the high voltage battery 107.
On the other hand, when the state of charge SOC is higher than the set value SLSOC, the high voltage battery 107 is not required to be charged (in other words, the remaining capacity is close to the full charge capacity), and surplus electrical energy is reduced. Even if it is recovered, it cannot be stored in the high voltage battery 107.

If it is determined in step S201 that the state of charge SOC is lower than the set value SLSOC, the surplus of the recovered energy can be stored in the high voltage battery 107, and the surplus power can be stored in the fuel supply device (fuel pump). It is not necessary to consume in 12).
Therefore, when the state of charge SOC is lower than the set value SLSOC, the process proceeds to step S204, where the low target fuel pressure TGFUPRL is set according to the operating condition of the engine 102, and the actual fuel pressure FUPR approaches the low target fuel pressure TGFUPRL. As described above, the fuel pressure control (low fuel pressure mode) for calculating the drive duty DUTY (target applied voltage) of the fuel pump 12 is performed. At this time, the high voltage battery 107 is charged with the electric power recovered by energy regeneration and / or the electric power generated by increasing the output of the engine 102.

On the other hand, if the state of charge SOC is higher than the set value SLSOC and surplus power is generated due to energy regeneration, if the surplus power cannot be recovered by the high voltage battery 107, the process proceeds to step S202.
In step S <b> 202, it is determined whether or not it is a condition that power exceeding the power consumption can be recovered by energy regeneration and surplus power is generated. In other words, in step S202, if the amount of regenerative energy is not suppressed in energy regeneration for converting kinetic energy into electrical energy, is there more power that can be recovered than the power consumption (in the low fuel pressure mode) at that time? Judge whether or not.

The conditions for generating surplus power are the cases where surplus power is actually generated and discharging the surplus power, and the conditions for enabling energy regeneration to the extent that surplus power is generated. And the case where the amount of energy regeneration is suppressed so as not to occur.
If surplus power does not occur, i.e. if the recoverable power at that time is less than or equal to the power consumption, or if surplus power is generated but the amount is not sufficient to do the work, step Proceeding to S204, the fuel pressure control in the low fuel pressure mode is performed.

As the fuel pressure control mode, the above-described low fuel pressure mode and a high fuel pressure mode in which the fuel pressure is higher than that in the low fuel pressure mode are set. By selecting the pressure mode, the power consumption in the fuel pump 12 is suppressed relatively low, and the regenerative power is applied to the power consumption at that time.
On the other hand, if surplus power is generated, that is, if the power that can be recovered at that time is greater than the power consumption, even if all of the power that can be regenerated is applied to the power consumption at that time, the regenerative power In addition, the high voltage battery 107 is in a fully charged state, and the remaining regenerative power (surplus power) cannot be stored in the high voltage battery 107, so that the amount of regenerative power is reduced or the surplus power is discharged. It becomes necessary to do.

Therefore, in step S202, when it is determined that the power that can be recovered at that time is greater than the power consumption and surplus power is generated, the recovered power is effectively used while promoting the conversion of kinetic energy into electric energy. Accordingly, the process proceeds to step S203 to switch to the high fuel pressure mode.
In step S203, the target fuel pressure TGFUPRH higher than the low target fuel pressure TGFUPRL in the low fuel pressure mode in step S204 is set, and the drive duty DUTY of the fuel pump 12 is set so that the actual fuel pressure FUPR approaches the high target fuel pressure TGFUPRH. Fuel pressure control is performed to calculate (target applied voltage).

When the process proceeds to step S203, the power consumption in the fuel pump 12 increases and the overall power consumption increases. Therefore, when energy regeneration is performed in a range where no surplus power is generated, the energy to be regenerated is consequently obtained. When the amount (regenerative power amount) is increased and the surplus power is discharged, the power to be discharged is reduced.
In the processing in step S203 (high fuel pressure mode), a map for low fuel pressure mode referred to in step S204 and surplus power are used as a map in which the target fuel pressure TGFUPR is stored in accordance with the operating state, so as to use step S203. As the target fuel pressure TGFUPR corresponding to the same operating condition, the value in the map for the high fuel pressure mode is higher than the value in the map for the low fuel pressure mode. This can be achieved by setting it to a high value.

Further, the low target fuel pressure TGFUPRL determined in the low fuel pressure mode in step S204 can be increased and corrected to the high target fuel pressure TGFUPRH for the high fuel pressure mode used in step S203.
Further, while the low target fuel pressure TGFUPRL determined in step S204 is changed according to the engine operating conditions, the high target fuel pressure TGFUPRH determined in step S203 may be set to a constant value unrelated to the engine operating conditions. it can.

In step S203, as shown in FIG. 4, the higher the surplus power, the higher the target fuel pressure TGFUPRH can be set.
That is, even if the surplus power is used up, if the high target fuel pressure TGFUPRH cannot be reached, the power stored in the low voltage battery 110 is used and the power stored in the high voltage battery 107 is used. Is used to charge the low-voltage battery 110, but if the power required to reach the high target fuel pressure TGFUPRH is less than the surplus power, part of the energy that can be regenerated is wasted. Will do.

Therefore, if the higher target fuel pressure TGFUPRH is set to a higher value as the surplus power is larger, it is possible to suppress the need for more power than the surplus power for boosting, and more of the power that can be regenerated is effective. Available.
When the target fuel pressure TGFUPR is changed to a higher value, the drive duty of the fuel pump 12 is increased so that the actual fuel pressure FUPR follows the increase change of the target fuel pressure TGFUPR, and the applied voltage of the fuel pump 12 is increased to a higher value. As a result, the actual fuel pressure FUPR increases and changes toward the high target fuel pressure TGFUPRH after the change.

That is, the power consumption of the fuel pump 12 is increased by shifting from the low fuel pressure mode to the high fuel pressure mode, and the regenerative power surplus in the low fuel pressure mode is consumed by shifting to the high fuel pressure mode. Is possible.
The increase in power consumption due to the shift to the high fuel pressure mode is supplied by the DC-DC converter 108. Since energy regeneration is performed at this time, as a result, the recovered electrical energy is reduced. The fuel pump 12 is supplied for boosting.

That is, if it is not shifted to the high fuel pressure mode, surplus power that cannot be stored in the high voltage battery 107 is generated. Therefore, the regenerative power amount is reduced to reduce the surplus power amount or the surplus power is discharged. However, if the mode is shifted to the high fuel pressure mode, the power consumption in the fuel pump 12 increases due to the pressure increase. As a result, the energy regeneration is performed without reducing the amount of regenerative power, and the surplus Electric power can be reduced.
Here, the power consumption increased in the fuel pump 12 for boosting is applied in the low fuel pressure mode by the power that can be recovered but not recovered or the power that was to be discharged. It does not reduce performance.

  However, when the target fuel pressure TGFUPR is reduced by switching from the high target fuel pressure TGFUPRH (high fuel pressure mode) to the low target fuel pressure TGFUPRL (low fuel pressure mode) under the condition that no surplus power is generated even in the low fuel pressure mode. Until then, the actual fuel pressure FUPR is made to follow the high target fuel pressure TGFUPRH, so the actual fuel pressure FUPR is higher than the low target fuel pressure TGFUPRL. In order to reduce the fuel pressure FUPR higher than the low target fuel pressure TGFUPRL, the applied voltage (drive duty) of the fuel pump 12 is maintained at the low target fuel pressure TGFUPRL as a result of feedback control. The power consumption of the fuel pump 12 is reduced by lowering (including the applied voltage = 0V).

That is, when the state of charge SOC is higher than the set value SLSOC and surplus power cannot be stored in the high voltage battery 107, for example, the braking force distribution of the hydraulic brake is increased to reduce the regenerative energy amount (regenerative power amount), If the excess power is reduced, the electric energy (electric power) that can be originally recovered is wasted.
Therefore, by increasing the fuel pressure FUPR, the power consumption of the fuel pump 12 is increased, the electric energy that can be recovered is effectively used, and the recovered electric energy is converted into pressure and stored, so that the pressure is increased. While lowering to near the low target fuel pressure TGFUPRL, the power consumption of the fuel pump 12 is reduced and the energy efficiency of the vehicle is improved.

  In step S203, it is sufficient to increase the fuel pressure FUPR using regenerative energy. In step S203, the fuel duty FUPR is fixed to a drive duty (applied voltage) stored in advance as a value that causes the fuel pressure FUPR to increase. be able to. The driving duty to be fixed is a value higher than the value corresponding to the low target fuel pressure TGFUPRL in the low fuel pressure mode set in step S204, and may include 100%.

  In step S203, instead of increasing the target fuel pressure TGFUPR, the fuel pressure FUPR detected by the fuel pressure sensor 33 is corrected to decrease, and the drive duty can be calculated based on the corrected fuel pressure FUPR. With such a configuration, when the drive duty is calculated based on a pressure lower than the actual fuel pressure FUPR and converged to the low target fuel pressure TGFUPRL in the low fuel pressure mode, the target fuel pressure TGFUPRL is actually low. Will converge to a higher fuel pressure.

In other words, the process of step S203 only needs to make the actual fuel pressure FUPR higher than when the process proceeds to step S204, and known means can be used as appropriate.
However, depending on the operating conditions, there are cases where the fuel pressure cannot be increased, or when the fuel pressure is increased, the operability may be reduced. In this case, the conditions of step S201 and step S202 are satisfied. Even so, the process of increasing the fuel pressure FUPR can be prohibited.

The time chart of FIG. 5 shows changes in power generation energy, fuel pressure, drive voltage of the fuel pump 12, and power consumption of the fuel pump 12 when the routine shown in the flowchart of FIG. 3 is executed.
In the time chart of FIG. 5, at time t1, if it is determined that surplus power is generated in a state where the state of charge SOC is higher than the set value SLSOC and the recovered electrical energy cannot be recovered by the high voltage battery 107, the target fuel pressure TGFUPR is increased. By changing the voltage, the voltage applied to the fuel pump 12 is increased, and the fuel pressure is increased using surplus power.

  At time t2, when the amount of power that can be recovered decreases (including recovered power = 0W) and no surplus power is generated even after returning to the low fuel pressure mode, the high target fuel pressure TGFUPRH (high fuel pressure mode) Is returned to the low target fuel pressure TGFUPRL (low fuel pressure mode), but since the actual fuel pressure FUPR is higher than the low target fuel pressure TGFUPRL at this point, the actual fuel pressure FUPR converges around the low target fuel pressure TGFUPRL from time t2. Until time t3, the driving duty (applied voltage) of the fuel pump 12 calculated by comparing the actual fuel pressure FUPR and the low target fuel pressure TGFUPRL is lower than when the low target fuel pressure TGFUPRL is maintained. As a result, power consumption in the fuel pump 12 is reduced.

  Here, the electric power consumed by the fuel pump 12 to increase the actual fuel pressure FUPR uses surplus electrical energy that has no place to go because the state of charge SOC is higher than the set value SLSOC. Although the power consumption is increasing, it does not deteriorate the fuel consumption performance. After returning to the low target fuel pressure TGFUPRL, the fuel pressure FUPR is higher than the low target fuel pressure TGFUPRL, so the power consumption of the fuel pump 12 decreases. This will contribute to improving fuel efficiency.

  By the way, when the high target fuel pressure TGFUPRH (high fuel pressure mode) is returned to the low target fuel pressure TGFUPRL (low fuel pressure mode), if the actual fuel pressure FUPR is sufficiently higher than the low target fuel pressure TGFUPRL, the target The drive control of the fuel pump 12 based on the fuel pressure TGFUPR and the actual fuel pressure FUPR can be forcibly stopped, thereby reducing the power consumption of the fuel pump 12 as compared with the case where the drive duty is gradually reduced by feedback control. This can be further reduced.

The flowchart of FIG. 6 shows a second embodiment in which the process for forcibly stopping the drive control of the fuel pump 12 is performed after the fuel pressure FUPR is increased using the surplus power of the regenerative power as described above. .
In the flowchart of FIG. 6, in steps S301 to S303, processing similar to that in steps S201 to S203 described above is performed.

That is, in step S301, it is determined whether or not the SOC indicating the state of charge of the high voltage battery 107 is higher than the set value SLSOC.
If the state of charge SOC is higher than the set value SLSOC, the process proceeds to step S302. If the condition is that surplus power is generated, the process proceeds to step S303.

In step S303, as a process for increasing the fuel pressure FUPR using surplus power, for example, the target fuel pressure TGFUPR is set to a target fuel pressure TGFUPRH higher than the low target fuel pressure TGFUPRL set in step S305 described later (high fuel pressure mode). ).
In step S303, when the process of increasing the fuel pressure FUPR using the surplus power (high fuel pressure mode) is performed, the process proceeds to step S304, and the flag F is set to 1.

If it is determined in step S301 that the state of charge SOC is lower than the set value SLSOC, or if it is determined in step S302 that it is not a condition for generating surplus power, the process proceeds to step S305.
In step S305, a low target fuel pressure TGFUPRL lower than the high target fuel pressure TGFUPRH is set according to the engine operating conditions (low fuel pressure mode).

In the next step S306, the flag F is determined.
Here, when the flag F = 1, it indicates that the process of increasing the fuel pressure FUPR was performed using the surplus power until immediately before.
If the flag F = 1, the process proceeds to step S307.

In step S307, it is determined whether or not the fuel pressure FUPR at that time is higher than the low target fuel pressure TGFUPRL by a threshold SL (SL> 0) or more (FUPR ≧ TGFUPRL + SL).
Even if the fuel pressure FUPR is resumed from the state where the fuel pressure FUPR is higher than the low target fuel pressure TGFUPRL by the threshold SL, and the discharge amount of the fuel pump 12 changes later, the fuel pressure FUPR It is set in advance as a lower limit value in a range that does not fall below the low target fuel pressure TGFUPRL.
In other words, if the fuel pressure FUPR at that time is in a state higher than the low target fuel pressure TGFUPRL by a threshold SL or more, it can be determined that the drive control of the fuel pump 12 can be held in a stopped state, while the fuel pressure FUPR is low. If the drive control of the fuel pump 12 is resumed after the fuel pressure TGFUPRL + the threshold SL is lowered, it can be determined that the fuel pressure FUPR may fall below the low target fuel pressure TGFUPRL due to a control response delay or the like. It is.

When it is determined in step S307 that the fuel pressure FUPR at that time is higher than the low target fuel pressure TGFUPRL by a threshold value SL or more, the process proceeds to step S308, and the drive duty based on the comparison between the fuel pressure FUPR and the target fuel pressure TGFUPR is increased. The calculation control is stopped, and the drive duty is decreased by a predetermined step width every control cycle to forcibly change it to 0% (applied voltage is 0 V), the power supply to the fuel pump 12 is cut off, and the fuel pump 12 (fuel supply device) is temporarily stopped.
While the fuel pump 12 is stopped, the power consumption of the fuel pump 12 becomes substantially zero.

  When the lower limit value (> 0%) of the drive duty is set in advance, the lower limit value can be held after the drive duty is lowered to the lower limit value. The power consumption in the fuel pump 12 can be reduced as compared with the case where the drive duty is calculated based on the comparison between the FUPR and the target fuel pressure TGFUPR.

While the fuel pump 12 is stopped, the fuel is injected into the engine 1 and the fuel is relieved from the pressure regulator 14. As a result, the fuel pressure FUPR gradually decreases and approaches the low target fuel pressure TGFUPRL.
When the fuel pressure FUPR at that time becomes lower than the low target fuel pressure TGFUPRL + threshold, the process proceeds to step S309, the flag F is reset to zero, and then the process proceeds to step S310.

When the flag F is reset to zero in step S309, the process proceeds from step S306 to step S310 from the next time.
In step S310, feedback control is performed to bring the fuel pressure FUPR close to the low target fuel pressure TGFUPRL set in step S309.

  Thereby, when the fuel pressure FUPR at that time becomes lower than the low target fuel pressure TGFUPRL + threshold value, the drive control of the fuel pump 12 based on the comparison between the fuel pressure FUPR and the target fuel pressure TGFUPR is resumed, and the drive duty is changed every control cycle. As a result of the increase, the fuel pump 12 starts to operate (or increases the discharge amount), and then the fuel pressure FUPR is set to the low target fuel pressure TGFUPRL until the conditions of step S301 and step S302 are satisfied. Feedback control for approaching is continued.

The time chart of FIG. 7 shows changes in power generation energy, fuel pressure, drive voltage of the fuel pump 12, and power consumption of the fuel pump 12 when the routine shown in the flowchart of FIG. 6 is executed.
In the time chart of FIG. 7, at time t1, the power generation energy exceeds the power consumption, and surplus power is generated. However, if the state of charge SOC at that time is higher than the set value SLSOC, the surplus power is increased to a high voltage. The battery 107 cannot be recovered.

Therefore, by performing a process of increasing and changing the fuel pressure at time t1 (a process of increasing and changing the target fuel pressure TGFUPR), the voltage applied to the fuel pump 12 is increased, and the remaining power in the regenerative power is reduced ( In other words, among the regenerative power, the power consumed for work is increased).
At time t2, the amount of power that can be recovered decreases (including recovered power = 0W), and when no surplus power is generated even after returning to the low fuel pressure mode, the target fuel pressure TGFUPR is changed from the high target fuel pressure TGFUPRH to the low target fuel pressure TGFUPRL. However, since the actual fuel pressure FUPR is higher than the low target fuel pressure TGFUPRL by a threshold SL or more, the drive duty is gradually reduced to zero by stopping the drive control of the fuel pump 12.

Then, until the fuel pressure FUPR at that time is lower than the low target fuel pressure TGFUPRL + the threshold SL, the fuel pump 12 is held in the drive stop state (drive duty = 0% (or lower limit) state), and the time t3 The driving duty is gradually increased by restarting the feedback control for bringing the actual fuel pressure FUPR close to the low target fuel pressure TGFUPRL.
Therefore, the power consumption of the fuel pump 12 is reduced within the drive stop period of the fuel pump 12 from the time t2 to the time t3, and the power consumption in the fuel pump 12 is further increased as compared with the case where the drive duty is reduced as a result of the feedback control. The fuel consumption performance of the vehicle can be further improved by reducing many.

In the second embodiment, the drive duty gradually decreases as the drive control of the fuel pump 12 stops. However, if the drive duty is decreased stepwise, the power consumption of the fuel pump 12 can be further reduced. A third embodiment having such a configuration will be described with reference to the flowchart of FIG.
The routine shown in the flowchart of FIG. 8 differs from the routine of the second embodiment shown in the flowchart of FIG. 6 in the processing contents in step S408, but the processing contents in other steps are the same, and the processing contents are the same. Different step S408 will be described in detail.

If the actual fuel pressure FUPR is higher than the low target fuel pressure TGFUPRL by a threshold SL or more immediately after returning to the control based on the low target fuel pressure TGFUPRL from the state in which the fuel pressure FUPR is increased using the surplus power, in step S408 Then, the drive duty of the fuel pump 12 is changed stepwise to a set value (for example, 0% or a lower limit value greater than 0%).
In such a configuration, as in the second embodiment, the time to reach 0% is shortened compared to the case where the drive duty is gradually reduced to 0% (set value) based on the stop command for drive control. The power consumption of the fuel pump 12 can be further reduced.

The time chart of FIG. 9 shows changes in power generation energy, fuel pressure, fuel pump 12 drive voltage, and power consumption of the fuel pump 12 when the routine shown in the flowchart of FIG. 8 is executed.
In FIG. 9, when the amount of electric power that can be recovered at time t2 decreases (including recovered electric power = 0 W), and no surplus electric power is generated even after returning to the low fuel pressure mode, the low target fuel pressure TGFUPRL (low fuel pressure mode) However, since the actual fuel pressure FUPR is higher than the low target fuel pressure TGFUPRL by the threshold value SL and it is not necessary to discharge the fuel from the fuel pump 12, the drive duty of the fuel pump 12 is stepped from the previous value. The value is changed to a set value (for example, 0% or a lower limit value greater than 0%), and the state of minimum power consumption (including power consumption = 0 W) is reached as quickly as possible.

Then, when the fuel pressure FUPR gradually decreases and becomes lower than the low target fuel pressure TGFUPRL + threshold SL, the drive control based on the actual fuel pressure FUPR and the low target fuel pressure TGFUPRL of the fuel pump 12 is resumed for each control cycle. Increase the drive duty with a predetermined step width to converge to the low target fuel pressure TGFUPRL.
In addition, although the vehicle of the said embodiment is a hybrid vehicle, application of this invention is not limited to a hybrid vehicle. For example, in an engine including an alternator driven by an engine and a low-voltage battery charged with power generated by the alternator, for example, when the alternator generates power using surplus kinetic energy when the accelerator is off (alternator). When the surplus power is generated and the state of charge SOC of the low voltage battery is high, the surplus power can be used to increase the fuel pressure FUPR.

Further, in the above embodiment, in preparation for an operating state of a vehicle that requires atomization of fuel injected from the fuel injection valve, the fuel pump is driven to increase the fuel pressure when surplus power is generated. This has the advantageous effect of reducing the amount of unburned fuel (HC) emitted and improving the charging efficiency.
Vehicle operating conditions that require fuel atomization include when the engine is started (when the engine is cold) or when the engine is heavily loaded (when the accelerator is on). The fuel is atomized when the engine is started (when the engine is cold). As a result, vaporization of the fuel spray can be promoted to reduce the amount of unburned fuel (HC), and the fuel can be atomized at high engine loads (accelerator-on). The intake air cooling due to the vaporization of the air is promoted, and the charging efficiency can be improved (output improvement).

Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.
(A) In the vehicle control device according to any one of claims 1 to 3,
The vehicle control apparatus which raises the fuel pressure higher as the surplus power is higher.
According to the said invention, it can suppress that electric power more than surplus electric power is needed for pressure | voltage rise, and can utilize much electric power which can be regenerated.

  DESCRIPTION OF SYMBOLS 101 ... Hybrid vehicle, 102 ... Engine (internal combustion engine), 103 ... Electric motor (motor M / generator G), 106 ... Inverter, 107 ... High voltage battery, 108 ... DC-DC converter, 110 ... Low voltage battery, 111 ... Hybrid control module (HVCM), 112 ... Engine control module (ECM), 113 ... Brake control module (BCM), 114 ... Hydraulic brake device, 115 ... Battery monitoring module (BMM), 12 ... Fuel pump , 30 ... Fuel control module (FCM)

Claims (3)

In a vehicle provided with an electric power regeneration device, a battery that stores electric power collected by the electric power regeneration device, and a fuel supply device that pumps fuel to an internal combustion engine,
When the state of charge of the battery is higher than a set value and the power regeneration device recovers surplus power, the surplus power is used to increase the pressure of fuel supplied to the internal combustion engine by the surplus power. A vehicle control device having drive control means.   The vehicle control device according to claim 1, wherein the drive control unit temporarily stops driving of the fuel supply device after increasing the pressure of the fuel using the surplus power.   3. The vehicle control device according to claim 1, wherein the drive control unit reduces the drive power of the fuel supply device stepwise to a set value after increasing the pressure of the fuel using the surplus power. 4. .