JP4353075B2 - Fuel consumption reduction control device - Google Patents

Description

  The present invention relates to a fuel consumption reduction control device that automatically stops an engine when a predetermined stop condition is satisfied, and automatically starts the engine when another predetermined start condition is satisfied.

  When the vehicle is controlled to reduce fuel consumption by the fuel consumption reduction control device, if the vehicle stops at an intersection or the like, the engine is automatically stopped under a predetermined stop condition, and then under a predetermined start condition. By restarting the engine, it is possible to save fuel and improve exhaust emissions.

  If the driver can know the amount of fuel saved by automatically stopping the engine by the fuel consumption reduction control, the willingness to save fuel is improved. In view of this, an invention has been proposed in which the ratio of the automatic stop time to the total travel time is obtained to determine a measure of fuel consumption savings during normal travel (see, for example, Patent Document 1).

Further, an invention has been proposed in which the fuel consumption during idling immediately before the engine is stopped is obtained, and the fuel saving amount is predicted and presented to the driver by the product of the time during which the engine is automatically stopped and the fuel consumption. (For example, refer to Patent Document 2). In the invention described in Patent Document 2, the fuel saving amount can be accurately predicted and displayed to the driver, so that the awareness of fuel saving can be improved.
Japanese Patent Publication No. 5-26018 JP 2000-205030 A

  However, the invention described in Patent Document 2 presents a fuel saving amount when the engine is stopped, and does not prompt the driver to save fuel consumption.

  In fuel consumption reduction control, the engine automatically stops according to certain conditions such as the vehicle speed and the engine speed, but depending on the type of vehicle and the driving conditions, the driver's operation such as a shift operation may stop the engine. It may be necessary to satisfy the condition. In such a vehicle or traveling state, there is a case where the fuel consumption control is possible, but the driver does not perform a predetermined operation, so the engine is not stopped and the fuel consumption is not reduced.

  In view of the above problems, an object of the present invention is to provide a fuel consumption reduction control device that can prompt the driver to perform an operation for stopping the engine when the engine can be stopped.

In order to solve the above problem, the present invention stops the engine until a predetermined condition based on the state of the vehicle is satisfied when an automatic engine stop condition is satisfied and a predetermined operation of the vehicle is detected. In the fuel consumption reduction control device, when the automatic stop condition is satisfied but the predetermined operation is not detected, the engine stoppable time is measured, and the product of the stoppable time and the idling fuel consumption is calculated. A predictive saving fuel amount calculating means; and a predictive saving fuel amount display means for displaying the predicted saving fuel amount calculated based on the stoppable time during measurement that changes every moment .

  According to the present invention, when the engine can be stopped, it is possible to provide a fuel consumption reduction control device that can prompt the driver to perform an operation for stopping the engine.

In one form of the present invention, the predicted savings fuel amount calculating means, said a stoppable time was possible stopping of the engine when the operation is detected, the idling is the fuel consumption per unit time of idling The predicted saving fuel amount is calculated based on the fuel consumption amount . The time during which the engine can be stopped may be measured after determining the presence or absence of a predetermined operation by the driver, or may be started from a state where the engine can be stopped.

  In one embodiment of the present invention, when a predetermined operation is detected, a saved fuel amount calculating unit that calculates a reduced fuel consumption amount and a saved fuel amount calculated by the saved fuel amount calculating unit are displayed. And a fuel amount display means.

  According to the present invention, even when the engine is stopped, the reduced fuel consumption can be displayed, so that the willingness to save fuel can be improved.

  When the engine can be stopped, a fuel consumption reduction control device that can prompt the driver to perform an operation for stopping the engine can be provided.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an entire engine drive system to which a fuel consumption reduction control apparatus suitable for the present invention is applied. The engine drive system of FIG. 1 automatically stops the engine when a predetermined stop condition is satisfied, and restarts the engine when a predetermined restart condition including depression of an accelerator pedal is satisfied while the engine is automatically stopped. The fuel consumption reduction control can be executed.

The engine drive system includes an engine 2, an engine electronic control unit (hereinafter referred to as an engine ECU) 5, an eco-run electronic control unit (hereinafter referred to as an eco-run ECU) 6, and an ABS (anti-skid brake system) electronic control unit (hereinafter referred to as an “eco-run ECU”). , Referred to as brake ECU) 7.

  The engine 2 is provided with an alternator 21 and a starter 22, and power is supplied from the battery 19 to the starter. In addition, power is supplied from the battery to the auxiliary machine load 18 which is an in-vehicle device such as accessories.

  The engine ECU 5 includes a CPU, a ROM, and a RAM, performs processing such as calculation based on various input signals, and outputs various signals to the engine 2 and the eco-run ECU 6.

  More specifically, the engine ECU 5 receives signals relating to accelerator on / off, accelerator opening, shift position sensor 16 from shift position, NE sensor 17 from engine speed, and the like. Further, an engine stop command signal and an engine restart command signal output from the eco-run ECU 6 are input to the engine ECU 5. The accelerator on / off signal, shift position, and engine speed input to the engine ECU 5 are input to the eco-run ECU 6.

  The eco-run ECU 6 includes a CPU, a ROM, and a RAM in the same manner as the engine ECU 5. The eco-run ECU 6 automatically stops and restarts the engine in the fuel consumption reduction control based on the status signal indicating the state of each part of the engine drive system. Outputs various command signals for execution.

  More specifically, the eco-run ECU 6 receives status signals representing statuses such as a fuel injection state, an intake air amount state, and an ignition state output from the engine ECU 5. Further, the eco-run ECU 6 receives from the clutch SW sensor 13 a clutch SW signal indicating ON / OFF of the clutch pedal, the voltage of the battery 19, the negative pressure of the vacuum booster, and the like.

  Further, the eco-run ECU 6 outputs to the engine ECU 5 an engine stop command signal for performing fuel consumption reduction control and an engine restart command signal for restarting the engine. Thereby, the engine ECU 5 outputs control signals such as fuel injection, intake air, and ignition control to the engine 2. Further, when the engine is restarted, the eco-run ECU 6 outputs a restart starter control signal to the starter.

  The eco-run ECU 6 stores the fuel consumption per unit time in the idling state (hereinafter referred to as fuel consumption during idling), and the idling fuel consumption is multiplied by, for example, the idling time. Fuel can be calculated. The eco-run ECU 6 measures the time during which the engine is stopped by the fuel consumption reduction control (hereinafter referred to as the engine stop time). Therefore, the economy saved by stopping the engine by the product of the engine stop time and idling fuel consumption. Calculate the amount of fuel.

  Further, the eco-run ECU 6 determines whether or not there is an operation by the driver when the predetermined operation by the driver is the stop condition as the engine stop condition by the fuel consumption reduction control. If the engine can be stopped if there is a driver's operation, the time during which the engine can be stopped (hereinafter referred to as the engine stoppable time) is measured, so the product of the engine stoppable time and idling fuel consumption The predicted saving fuel amount that is predicted to have been reduced is calculated.

  Further, the eco-run ECU 6 of the present embodiment is connected to the display device 20 and displays the engine stop time and the saved fuel amount or the engine stop possible time and the predicted saved fuel amount on the display device 20.

  The brake ECU 7 includes a CPU, a ROM, and a RAM similarly to the engine ECU 5. The brake ECU 7 includes a brake master pressure from the brake master pressure sensor 11, a vehicle speed from the vehicle speed sensor 12, a wheel speed signal from the wheel speed sensor 14, and a brake negative signal. A signal such as a booster cylinder negative pressure signal is input from the pressure sensor 13.

  The brake ECU 7 calculates the wheel speed and the braking slip ratio of each wheel based on the wheel speed and the vehicle speed of each wheel by a method well known in the art, and the braking slip ratio of any wheel is the reference for starting the ABS control. When the value exceeds the value (when the ABS control start condition is satisfied), the brake cylinder brake pressure is increased or decreased so that the brake slip ratio is within a predetermined range for the wheel until the ABS control end condition is satisfied. Perform skid control. The vehicle speed signal, wheel speed signal, and booster cylinder negative pressure signal input to the brake ECU 7 are input to the eco-run ECU 6.

  A control procedure when the engine is automatically stopped when a predetermined stop condition is satisfied in the engine drive system of FIG. 1 will be described. The engine stop condition by the fuel consumption reduction control is, for example, (a) the vehicle speed is zero or below a predetermined value, (b) the battery voltage is above a predetermined value, and (c) the booster cylinder negative pressure is predetermined. The engine is automatically stopped when one or more of the set conditions such as (d) the shift position is the neutral position, (e) the clutch is off, is satisfied. Is called.

  By the way, the conditions (a) to (c) are satisfied regardless of the will of the driver, such as the running or stopped state of the vehicle, but the conditions (d) and (e) are satisfied by the operation of the driver. Therefore, the automatic stop of the engine is performed automatically under conditions (hereinafter referred to as automatic stop conditions) determined independently of the driver's will as in the conditions (a) to (c) and automatically as in the conditions (d) and (e). It is divided into a condition (hereinafter referred to as an operation stop condition) that is established when there is a driver's operation (based on the driver's will) in a state where the stop condition is satisfied.

  For example, when the vehicle is an automatic transmission, the condition (d) may be an operation stop condition. When the vehicle is a manual transmission (hereinafter referred to as MT), the conditions (d) and (e) are the operation stop conditions. is there.

  When it is determined that the automatic stop condition is satisfied among the engine stop conditions (a) to (e), the eco-run ECU 6 can detect that the engine can be automatically stopped when the operation stop condition is satisfied.

  In the above description, the difference in transmission has been described as an example, but whether the automatic stop condition or the operation stop condition is not determined by the difference in transmission, the engine is stopped by the driver's operation when the automatic stop condition is satisfied. The operation condition is an operation stop condition.

  Further, the conditions (a) to (e) are design matters, and there may be an automatic stop condition in addition to the conditions (a) to (c), and an operation other than the condition (d) or (e). There may be a stop condition. The eco-run ECU 6 determines whether or not these automatic stop conditions and operation stop conditions are satisfied by executing a program stored in the ROM. When the eco-run ECU 6 determines that the conditions (a) to (e) are satisfied, the eco-run ECU 6 outputs an engine stop command signal to the engine ECU 5. As a result, the engine ECU 5 outputs to the engine 2 a fuel injection signal for cutting the supply of fuel to the engine and an intake signal for cutting intake air to the engine. When there is no fuel injection or intake, the engine 2 automatically stops. When the engine 2 is automatically stopped, the eco-run ECU 6 turns on and holds a flag indicating that the engine has been automatically stopped.

  Next, processing when the engine 2 is automatically stopped and restarted when a predetermined restart condition is satisfied will be described. First, it is determined based on the flag whether or not it is an automatic stop. If the engine is not automatically stopped, the restart process is not performed so that the engine is not automatically started. When the automatic stop is in progress, the brake master pressure is monitored. When the foot brake is fully depressed, the automatic stop is continued.

  When the foot brake is not fully depressed, (x) the brake master pressure is continuously monitored. For example, when the foot brake is not depressed even after a predetermined time has elapsed, (y) the accelerator opening degree by the accelerator SW15 One or more conditions are established, such as when the accelerator is depressed more than a predetermined value by monitoring the signal, (z) when the vehicle speed signal by the vehicle speed sensor 12 is monitored and the vehicle speed exceeds a predetermined value (in the case of a hybrid vehicle) In this case, it is determined that the driver intends to travel and engine restart control is performed. Note that the restart conditions of the engine 2 listed in (x) to (z) are design matters, and the restart conditions of the engine are set based on various vehicle states. Further, the engine may be restarted when the driver performs an engine restart operation.

  In the engine restart control, the eco-run ECU 6 outputs an engine restart command signal to the engine ECU 5 and outputs a starter control signal to the starter. As a result, the engine ECU 5 outputs control signals for fuel injection, intake air, and ignition control to the engine 2 in accordance with the drive timing of the starter, so that the engine 2 is restarted.

  Next, a control procedure of fuel consumption reduction control in the engine drive system of the present embodiment will be described based on the flowchart of FIG. When the engine 2 is started, the eco-run ECU 6 determines whether an automatic engine stop condition (for example, one or all of the above (a) to (c)) is satisfied (S11). When the automatic stop condition is not satisfied (No in step S11), the eco-run ECU 6 repeats the determination in step S11.

  When the automatic stop condition is satisfied (Yes in step S11), it is then determined whether or not an operation stop condition (for example, one or all of the above (d) or (e)) is satisfied (S12). When an operation stop condition is satisfied, such as when the shift position is shifted to neutral (Yes in S12), the eco-run ECU 6 stops the engine. The eco-run ECU 6 starts measuring the engine stop time from the time when the engine is stopped, calculates the product of the engine stop time and the idling fuel consumption, and saves fuel that is saved by the automatic engine stop. The amount is calculated (S13).

  The eco-run ECU 6 displays the engine stop time during measurement and / or the calculated saved fuel amount on the display device 20 (S14). For example, the fuel saving amount is displayed together with the engine stop time that changes every moment. The engine stop time and the saved fuel amount may be displayed simultaneously or mutually.

  Next, the eco-run ECU 6 determines whether or not an operation stop condition is satisfied (S15). If the operation stop condition is satisfied (Yes in step S15), the measurement of the engine stop time, the calculation of the saved fuel amount, and the display of the engine stop time and the saved fuel amount are continued (S13, S14).

  When the operation stop condition is not satisfied, such as when the shift position is shifted to the drive position (No in Step S15), the display of the engine stop time and the saved fuel amount is reset (S16). The eco-run time immediately before the operation stop condition is satisfied is stored in the RAM of the eco-run ECU 6. When the engine is stopped (Yes in step S12), the control procedure in FIG. After the operation stop condition is not satisfied, the eco-run ECU 6 starts the engine based on whether a restart condition (for example, one or all of the above (x) to (z)) is satisfied.

  In step S12, when the operation stop condition is not satisfied (No in S12), the eco-run ECU 6 starts measuring the engine stoppable time from the time when the determination in step S12 is performed, and the engine stoppable time and idling. A product with the hourly fuel consumption is calculated, and a predicted saved fuel amount that is predicted to be saved if the engine is stopped is calculated (S17). The engine stoppable time may be measured from the time when the determination in step S11 is performed.

  If the operation stop condition is not satisfied (No in S12), the engine is in the idling state, and therefore the actual fuel consumption in the idling state is not the fuel consumption during idling stored in the ROM of the eco-run ECU 6. The predicted saving fuel amount may be calculated by using it.

  Further, the eco-run ECU 6 displays on the display device 20 the engine stoppable time being measured and / or the calculated predicted saving fuel amount (S18). For example, the predicted saving fuel amount is displayed together with the engine stoppable time that changes every moment. The engine stoppable time and the predicted saving fuel amount may be displayed at the same time or may be displayed mutually.

  In steps S12 to S18, the automatic stop condition is satisfied, but the engine is in an idling state because the driver does not perform an operation to satisfy the operation stop condition. The driver can recognize that the engine can be stopped and the fuel consumption can be reduced by visually checking the engine stop possible time and / or the predicted saving fuel amount. Therefore, by displaying the engine stoppable time and / or the predicted saving fuel amount, the driver can be prompted to perform an operation for satisfying the operation stop condition. Note that a sound, an alarm sound, or the like may be used in order to reliably notify that fuel consumption can be reduced.

  Next, the eco-run ECU 6 determines whether or not an automatic stop condition is satisfied (S19). When the automatic stop condition is satisfied (Yes in step S19), the processes in steps S12 to S18 are repeated. Therefore, until the operation stop condition is satisfied, measurement of the engine stoppable time, calculation of the predicted saving fuel amount, and display of the engine stoppable time and the predicted saving fuel amount are continued.

  When the automatic stop condition is not satisfied, such as when the engine speed increases (No in step S19), the display of the engine stoppable time and the predicted saved fuel amount is reset (S20). The eco-run possible time immediately before the automatic stop condition is satisfied is stored in the RAM of the eco-run ECU 6. Thus, the control procedure of FIG. 2 ends.

  The engine stop time stored in the RAM of the eco-run ECU 6 in step S16 and the engine stop time stored in the RAM of the eco-run ECU 6 in step S20 can be referred to at the next vehicle travel, and all the past or a predetermined period of engine stop It is preferable that the time and the amount of saved fuel, as well as the time when the engine can be stopped and the estimated amount of saved fuel can be displayed.

  According to the fuel consumption reduction control apparatus of the present embodiment, when the engine can be stopped if the driver operates, the predicted saved fuel amount that can be saved by stopping the engine is displayed. An operation for stopping the engine can be prompted. Therefore, the engine can be stopped by the fuel consumption reduction control to reduce the fuel consumption.

  Further, when the engine is actually stopped, the amount of fuel saved by the engine stop can be known, so that the effect of the engine stop can be realized, and the willingness to save fuel consumption is further increased.

The block diagram showing the whole engine drive system to which the fuel consumption reduction control apparatus was applied is shown. It is a flowchart figure which shows the control procedure of the fuel consumption reduction control in an engine drive system.

Explanation of symbols

2 Engine 5 Engine ECU
6 Eco-run ECU
7 Brake ECU
12 Vehicle speed sensor 13 Clutch switch sensor 14 Wheel speed sensor 15 Accelerator switch
16 Shift position sensor 17 NE sensor 20 Display device

Claims (3)

In the fuel consumption reduction control device that stops the engine until a predetermined condition based on a state of the vehicle is satisfied when an automatic engine stop condition is satisfied and a predetermined operation of the vehicle is detected,
A predictive saving fuel amount calculating means for measuring an engine stop possible time and calculating a product of the stop possible time and fuel consumption during idling when an automatic stop condition is satisfied but the predetermined operation is not detected; ,
A predicted saved fuel amount display means for displaying a predicted saved fuel amount calculated based on the stoppable time during measurement that changes every moment ;
A fuel consumption reduction control device comprising: The predicted savings fuel amount calculating means, based on the and stoppable time was possible stopping of the engine, and the idling fuel consumption is the fuel consumption per unit time of the idling state when the operation is detected Calculating the predicted saving fuel amount;
The fuel consumption reduction control apparatus according to claim 1. A saving fuel amount calculating means for calculating a reduced fuel consumption when the predetermined operation is detected;
A saved fuel amount display means for displaying the saved fuel amount calculated by the saved fuel amount calculation means;
The fuel consumption reduction control device according to claim 1, comprising:

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