JP3706735B2 - Automatic engine stop / start control device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic engine stop / start control device for a vehicle, which saves fuel consumption by stopping an engine when a predetermined condition is satisfied during idle operation.
[0002]
[Prior art]
In a conventional vehicle using an engine as a driving source for driving, once the engine is started, it does not stop unless the driver turns off the ignition switch. For example, the engine continues wasteful idle operation while waiting for a signal and wastes fuel. There was a problem to do. To avoid this, every time the vehicle stops, the driver should turn off the ignition switch to stop the engine, but this way the driver has to repeatedly start and stop the engine, The operation is extremely troublesome.
[0003]
Therefore, in a commercial vehicle equipped with a manual transmission, the engine is automatically stopped 1 to 2 seconds after the vehicle stops, and when the depression of the clutch pedal is detected from this state, the engine is automatically restarted. Thus, it is known to reduce fuel consumption.
[0004]
[Problems to be solved by the invention]
By the way, since the engine starting power supply is used not only for supplying power to the starter motor but also for supplying auxiliary equipment, if the capacity of the engine starting power supply decreases due to power supply to the auxiliary equipment while the engine is stopped, the vehicle starts. Sometimes the starter motor becomes inoperable and the engine cannot be restarted.
[0005]
The present invention has been made in view of the above circumstances, and an object thereof is to ensure that the engine can be restarted while extending the engine engine stop time as much as possible to reduce fuel consumption. And
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 supplies electric power to an engine, engine starting means for starting the engine, engine starting means and auxiliary equipment other than the engine starting means , And an engine starting power source charged by a generator driven by the engine, a starting power source remaining capacity detecting means for detecting the remaining capacity of the engine starting power source, and a consumption for detecting the power consumption taken out from the engine starting power source. Electric power detection means, fuel supply control means for controlling fuel supply to the engine, deceleration state detection means for detecting the deceleration state of the vehicle, and fuel supply control means when the deceleration state of the vehicle is detected by the deceleration state detection means Engine output control means including means for interrupting fuel supply to the engine by the engine output control means, the engine output control means comprising: After interruption of the fuel supply by the supply control means, and detects the remaining capacity of the power supply for starting the engine by the starting power supply remaining capacity detection means, is less than a predetermined capacity capable of starting the engine said residue capacity actuates an engine start means In this case, the engine continues to be driven while the engine is automatically stopped when the remaining capacity is greater than or equal to the predetermined capacity , and the remaining capacity of the engine starting power supply when the engine automatically stops after the engine is automatically stopped. Comparing the deviation obtained by subtracting the predetermined capacity from the integrated value of the power consumption after the engine is automatically stopped, and as a result, if the deviation is larger than the integrated value, the engine is maintained in a stopped state, If the deviation is equal to or less than the integrated value, the engine is started by the engine starting means.
[0007]
According to the above configuration, after the fuel supply to the engine at the time of deceleration of the vehicle is cut off , the engine is stopped if the remaining capacity of the engine starting power source is greater than a predetermined capacity that can start the engine by operating the engine starting means. It can be determined that the engine can be restarted, and the engine can be automatically stopped to reduce fuel consumption . On the other hand, if the remaining capacity of the engine starting power source is less than the predetermined capacity, the engine is stopped. If this is done, it may be determined that the engine cannot be restarted, and the engine can continue to be driven.
[0008]
On the other hand, after the engine is automatically stopped, the deviation is calculated by subtracting the predetermined capacity from the remaining capacity of the engine starting power source when the engine is automatically stopped, and the integrated value of power consumption after the engine is automatically stopped As a result, if the deviation is larger than the integrated value, it is determined that the engine can still be restarted, and the engine can be kept stopped to save fuel consumption. If the deviation is less than or equal to the integrated value, it can be determined that the engine cannot be restarted unless the engine is started early, and the engine can be started by operating the engine starting means.
[0009]
In this way, by stopping and starting the engine while monitoring whether or not the engine starting power source has sufficient power to start the engine, the engine stop time is extended as much as possible to reduce the fuel consumption. While reducing, it is possible to reliably avoid the engine from being unable to start.
[0010]
Here, the engine starting power source corresponds to the capacitor 3 of the embodiment, the engine starting means corresponds to the starter motor 7 of the embodiment, the generator corresponds to the motor M of the embodiment, and the starting power remaining capacity detecting means is corresponds to the capacitor remaining capacity sensor S ₇ for example, the power consumption detecting means corresponds to a 12-volt power sensor S ₈ embodiment, the power consumption corresponding to 12-volt power consumption instantaneous value DVP examples The remaining capacity of the power source for starting the engine corresponds to the remaining capacity QCAP of the capacitor of the embodiment, the predetermined capacity corresponds to the capacity QCAPIDL of the capacitor necessary for starting the engine, and the deviation is the margin of the remaining capacity of the capacitor of the embodiment. Corresponds to the minute QCAPABL.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples of the present invention shown in the accompanying drawings.
[0012]
1 to 10 show a first embodiment of the present invention. FIG. 1 is an overall configuration diagram of a hybrid vehicle having an automatic transmission, FIG. 2 is an explanatory diagram of a cruise / idle mode, and FIG. 3 is an acceleration mode. FIG. 4 is an explanatory diagram of the deceleration mode, FIG. 5 is a graph for explaining engine load reduction by the assist force of the motor, FIG. 6 is a claim correspondence diagram, and FIG. 7 is a first part of a flowchart of the main routine, FIG. 8 is a second part of the flowchart of the main routine, FIG. 9 is a flowchart of the subroutine of step S17 of the main routine, and FIG. 10 is a time chart showing an example of idle engine stop control.
[0013]
As shown in FIG. 1, the hybrid vehicle includes an engine E and a motor M, and the driving force of the engine E and / or the driving force of the motor M is transmitted to the front wheels Wf and Wf as driving wheels via an automatic transmission Ta. The When the driving force is transmitted from the front wheels Wf, Wf side to the motor M side during deceleration of the hybrid vehicle, the motor M functions as a generator to generate a so-called regenerative braking force, and recovers the kinetic energy of the vehicle body as electric energy. To do.
[0014]
The drive and regeneration of the motor M are controlled by a power drive unit 2 connected to an electronic control unit 1 made of a microcomputer. The power drive unit 2 is connected with a capacitor 3 as an electric storage means composed of an electric double layer capacitor. Capacitor 3 is a module in which 12 modules each having a maximum voltage of 2.5 volts connected in series are connected in series, and the maximum voltage is 180 volts. The hybrid vehicle is equipped with a 12-volt auxiliary battery 4 for driving various auxiliary machines, and this auxiliary battery 4 is connected to the capacitor 3 via a downverter 5. The downverter 5 controlled by the electronic control unit 1 charges the auxiliary battery 4 by reducing the voltage of the capacitor 3 to 12 volts.
[0015]
Although the maximum voltage of the capacitor 3 is 180 volts, the maximum voltage actually used for preventing deterioration due to overcharge is suppressed to 170 volts, and the minimum actually used for ensuring the operation of the downverter 5 The voltage is suppressed to 80 volts.
[0016]
In addition to the power drive unit 2 and the downverter 5, the electronic control unit 1 operates a fuel supply control means 6 for controlling the fuel supply to the engine E, and a starter motor driven by the electric power stored in the capacitor 3. 7 is controlled. For this purpose, the electronic control unit 1 includes a signal from the vehicle speed sensor S ₁ that detects the vehicle speed V based on the number of rotations of the rear wheels Wr and Wr, which are driven wheels, and an engine speed sensor S that detects the engine speed Ne. ₂ , a signal from the shift position sensor S ₃ that detects the shift position (neutral position, parking position, forward travel position and reverse travel position) of the automatic transmission Ta, and a brake switch that detects the operation of the brake pedal 8. The signal from S ₄ , the signal from the capacitor remaining capacity sensor S ₇ for detecting the remaining capacity of the capacitor 3, and the signal from the 12 volt system power consumption sensor S ₈ for detecting the power consumption taken out from the auxiliary battery 4. Entered.
[0017]
The electronic control unit 1 is provided with a deceleration state detection means M1 and the engine output control means M2 (see FIG. 6), the deceleration state detecting means M1 is a change in the vehicle speed V detected by the vehicle speed sensor S _1, detected by the throttle opening sensor Based on the throttle valve closing operation, the intake negative pressure detected by the intake negative pressure sensor, etc., it is detected that the vehicle is in a deceleration fuel cut state, and the engine output control means M2 is supplied to the engine E by the fuel supply control means 6. And the engine E is stopped.
[0018]
Next, an outline of control of the engine E and the motor M in each travel mode will be described.
(1) Cruise / idle mode As shown in FIG. 2, the motor M functions as a generator driven by the engine E during cruise driving of the vehicle or during idling of the engine E. The power consumption taken out from the 12-volt auxiliary battery 4 is estimated from the power upstream of the downverter 5, and the electric power that can supplement the 12-volt system power consumption is generated by the motor M and supplied to the auxiliary battery 4 side.
(2) Acceleration mode As shown in FIG. 3, the motor M is driven by the electric power taken out from the capacitor 3 to assist the output of the engine E and the 12-volt system consumption taken out from the auxiliary battery 4 when the vehicle is accelerated. Replenish power. The assist amount generated by the motor M is determined by map search based on the remaining capacity of the capacitor 3, the shift position, the engine speed, the throttle opening, the intake negative pressure, and the like.
(3) Deceleration mode As shown in FIG. 4, when the vehicle is traveling at a reduced speed, regenerative braking is performed with the driving force transmitted back to the motor M from the front wheels Wf, Wf, which are drive wheels, and the regenerative power generated by the motor M To charge the capacitor 3 and replenish the 12-volt power consumption taken out from the auxiliary battery 4. The regenerative braking amount generated by the motor M is determined by map search based on the shift position, the engine speed and the intake negative pressure.
[0019]
FIG. 5A shows the vehicle speed V (see the thin line) and the driving / regeneration amount of the motor M (see the thick line) when the vehicle travels in the 10.15 mode. During acceleration of the vehicle, the motor M generates driving force to reduce the load of the engine E, thereby reducing fuel consumption. When the vehicle is decelerating, the motor M generates regenerative braking force. Can effectively recover kinetic energy lost by mechanical braking as electrical energy.
[0020]
FIG. 5B shows the intake negative pressure corresponding to the load of the engine E. The thick line is the case where the assist by the motor M is performed, and the thin line is the case where the assist by the motor M is not performed. . In general, the thick line is located below the thin line, and it can be seen that the assist force of the motor M contributes to the load reduction of the engine E.
[0021]
By the way, a general vehicle cuts the fuel when decelerating, and when the engine speed drops to the idle speed, the fuel cut is stopped so that the engine E does not stop and the supply of fuel that can maintain the idling operation is resumed. It is supposed to be. However, in this embodiment, the engine E is stopped without returning the fuel supply following the fuel cut when a predetermined operating condition is satisfied, and the fuel supply is returned when the predetermined operating condition is not satisfied. By going and restarting the engine E, the engine E is stopped as much as possible during idle operation to further reduce fuel consumption.
[0022]
Next, the configuration of the idle engine stop control device of the present embodiment will be described based on FIG.
[0023]
The capacitor 3 supplies power to an electric load composed of various auxiliary machines including the starter motor 7 and is charged by a motor M that is driven by the engine E and functions as a generator. The remaining capacity of the capacitor 3 is detected by the capacitor remaining capacity sensor S _{7, and the} power consumption taken out from the capacitor 3 to the electric load is detected by the 12-volt power consumption sensor S ₈ .
[0024]
Even if the engine E is stopped based on the remaining capacity of the capacitor 3 detected by the capacitor remaining capacity sensor S ₇ and the power consumption detected by the 12-volt system power consumption sensor S ₈ , the electronic control unit 1 It is determined whether or not the engine E can be restarted by operating the starter motor 7 with electric power. When there is a surplus in the power of the capacitor 3, the fuel supply control means 6 prohibits resumption of fuel supply from the fuel cut and stops the engine, thereby reducing fuel consumption. When there is not enough power in the capacitor 3, the fuel supply control means 6 resumes the fuel supply from the fuel cut and maintains the idle operation without stopping the engine E. At this time, if the engine E has already stopped, the starter motor 7 is operated to start the engine E, thereby avoiding that the engine E cannot be started due to insufficient power of the capacitor 3.
[0025]
Next, specific contents of the idle engine stop control of the vehicle shown in FIG. 1 will be described based on the flowcharts of FIGS. 7 and 8.
[0026]
First, when the starter switch is OFF in step S1, that is, when the engine is not started by the driver, the starter switch OFF → ON determination flag F in step S2. The state of FCMGST is determined. Starter switch OFF → ON judgment flag F when the ignition switch is turned ON The initial value of FCMGST is “0”. After that, when the engine is started by the driver in step S1 and the starter switch is turned on, the starter switch OFF → ON determination flag F in step S15. FCMGST is set to “1” and remains set to “1” until the ignition switch is turned off.
[0027]
Accordingly, since the driver turns on the ignition switch and turns on the starter switch, the answer to step S2 is “0” and the process proceeds to step S13. Therefore, the engine start in step S12 described later is executed. There is nothing. That is, in this vehicle, as described later, the engine stop during idle operation and the subsequent engine start are performed regardless of the operation of the starter switch by the driver, but the driver first turns on the starter switch to run the vehicle. Unless indicated by intention, the engine E is not automatically started, thereby avoiding useless engine start and saving fuel consumption.
[0028]
Thus, when the driver turns on the starter switch in step S1, the starter switch OFF → ON determination flag F in step S15. After FCMGST is set to “1” and a reverse travel position determination delay timer tmSFTR described later is set in step S16, the process proceeds to step S11. In step S11, the comparison engine speed Ne detected by the engine speed sensor S ₂ is the engine stall judgment rotation speed NCR, if a Ne <NCR in the engine E is stopped, the starter motor 7 at step S12 It starts automatically and starts engine E. As a result, when the engine E starts and Ne ≧ NCR, the engine start in step S12 is passed and the process proceeds to step S13.
[0029]
Subsequently, in step S13, an idle engine stop control execution flag F Set FCMG to "0". Idle engine stop control execution flag F The FCMG is used to identify whether or not the engine E is to be stopped during idle operation. When it is set to “0”, the fuel supply is resumed following the fuel cut and the engine E is idle. Although it is maintained in the operating state, when it is set to “1”, the restart of the fuel supply following the fuel cut is prohibited by the command of the engine output control means M2 (or the amount of the idle operation cannot be maintained). The engine E is stopped without performing idle operation (only fuel is supplied). The idle engine stop control execution flag F The FCMG is set to “1” in step S18 when a predetermined condition to be described in detail later is satisfied. In subsequent step S14, a vehicle speed determination flag F, which will be described later, is provided. FCMGV is set to “0”.
[0030]
When the starter switch is turned off after the driver turns on the starter switch and starts the engine E in step S1, the starter switch OFF → ON determination flag F is already set in step S2. Since FCMGST is set to “1”, the process proceeds to step S3. In step S3, if the shift position detected by the shift position sensor S ₃ is not in the reverse drive position, sets the reverse drive position determination delay timer tmSFTR in step S4, also if the shift position is the reverse drive position in step S3 In step S5, it is determined whether or not the reverse travel position determination delay timer tmSFTR has expired after a predetermined time (for example, 0.5 seconds) has elapsed. As a result, if the reverse travel position determination delay timer tmSFTR is not up in step S5, the process returns to step S1, and if the time is up, the process proceeds to step S11.
[0031]
The meaning is as follows. In the vehicle of this embodiment, when the brake pedal 8 is depressed and the idle engine stop control is executed, if the foot is released from the brake pedal 8, the idle engine stop control is stopped and the engine E is automatically restarted. When the vehicle equipped with the automatic transmission Ta starts up, but repeats the creep pedal 8 ON / OFF operation repeatedly to creep into the garage, etc., and turns backward, the brake pedal 8 is turned ON / OFF. If engine E repeatedly stops and restarts, there is a problem that smooth reverse creep running becomes difficult. If the brake pedal 8 is depressed to switch from forward travel to reverse travel when entering the garage or the like, the engine E is stopped by the idle engine stop control. If the engine E is not restarted unless it is released, there is a problem that delicate reverse creep travel is not smoothly performed.
[0032]
However, in this embodiment, when the shift position is in the reverse drive position in step S3, the process proceeds to steps S11 and S12. If engine E is stopped at that time, the engine is quickly restarted, and in step S13, the idle engine is started. Stop control execution flag F Since FCMG is set to “0” and the idling engine stop control is stopped, the above-described problems can be solved by maintaining the engine E in the idling operation state. In addition, the above control is not executed unless the time for which the shift position is in the reverse drive position becomes 0.5 seconds or more counted by the reverse drive position determination delay timer tmSFTR. Therefore, the reverse drive is instantaneously executed in the process of operating the select lever. It is possible to avoid unnecessary control when the position is established.
[0033]
Subsequently, in step S6, the vehicle speed determination flag F The state of the FCMGV is determined. Vehicle speed judgment flag F FCMGV, immediately after the vehicle has started moving are set to "0", at the next step S7, the vehicle speed V detected by the vehicle speed sensor S ₁ is predetermined vehicle speed (e.g., 15km / h) becomes equal to or larger than, the step S8 With vehicle speed judgment flag F FCMGV is set to “1”. Therefore, unless the vehicle speed V exceeds 15 km / h in step S7, the process always proceeds to step S13 and the idle engine stop control execution flag F Since FCMG is set to “0” and the idle engine stop control is stopped, the idle engine stop control is not executed.
[0034]
The meaning is as follows. If the execution of the idle engine stop control is allowed when the vehicle creeps at extremely low speed while turning on / off the brake pedal 8 when entering the garage or in a traffic jam, the engine E is turned on when the brake pedal 8 is turned on / off. Stopping and restarting are repeatedly performed, and as a result, smooth running may not be possible. However, the above problem can be solved by prohibiting the execution of the idle engine stop control when the vehicle speed V is less than 15 km / h.
[0035]
In subsequent step S19, when the deceleration state detecting means M1 detects that the vehicle is in a decelerating state, the process proceeds to step S9. If the shift position is in the neutral position or the parking position in step S9, or the shift is performed in step S9. position even in the forward drive position, when the brake switch S ₄ and the brake pedal 8 is depressed is oN at step S10, the capacitor remaining capacity determination flag F goes to step S17 The state of FCMGCAP is determined.
[0036]
Capacitor remaining capacity determination flag F The FCMGCAP identifies whether or not the remaining capacity of the electric power stored in the capacitor 3 is sufficient to restart the stopped engine E. In step S17, the remaining capacity determination flag F If FCMGCAP is set to “1”, it is determined that the remaining capacity of the capacitor 3 is sufficient for restarting the engine E, and the process proceeds to step S18 to execute the idle engine stop control execution flag F. FCMG is set to “1”. As a result, the fuel supply control means 6 prohibits the resumption of fuel supply following the fuel cut based on a command from the engine output control means M2, so that when the engine speed Ne decreases to the idle speed, the engine E Be stopped. On the other hand, the capacitor remaining capacity determination flag F in step S17. If FCMGCAP is set to “0”, it is determined that the remaining capacity of the capacitor 3 is not sufficient to restart the engine E, and an idle engine stop control execution flag F is determined in step S13. FCMG is set to “0”. As a result, the fuel supply control means 6 resumes the fuel supply following the fuel cut as usual, so that the idling operation is permitted when the engine speed Ne decreases to the idle speed.
[0037]
As described above, when the shift position is in the neutral position or the parking position or during braking in which the brake pedal 8 is depressed even if the shift position is in the forward travel position, the engine E is stopped without being idled. Therefore, unnecessary idle operation of the engine E can be minimized and the fuel consumption can be reduced to the maximum. However, as described above, when the shift position is in the reverse travel position, when the vehicle speed V is less than 15 km / h, and when the remaining capacity of the capacitor 3 does not have enough room to restart the engine E. The execution of the idle engine stop control is prohibited.
[0038]
FIG. 10 is a time chart showing an example of idle engine stop control.
[0039]
The brake switch S ₄ is turned ON, the driver stepped on the brake pedal 8 to time t ₁ during cruising of the vehicle, the idle engine stop control execution flag F At the same time that FCMG is set to “1”, fuel cut by the fuel supply control means 6 is executed, and the vehicle speed V gradually decreases. It is a time t ₂ Oite engine speed Ne is reduced to idle speed, the idle engine stop control execution flag F Since FCMG is set to “1”, the fuel supply control means 6 does not resume fuel supply, and as a result, the engine E stops without performing idle operation. When the driver removes his / her foot from the brake pedal 8 at time t ₃ and the brake switch S ₄ is turned OFF, the idle engine stop control execution flag F At the same time that FCMG is set to “0”, fuel cut by the fuel supply control means 6 is completed and fuel supply is resumed, the engine E is started, and the vehicle can run again.
[0040]
Next, referring to the flowchart of FIG. The setting of FCMGCAP (see step S17 in the flowchart of FIG. 7) will be described.
[0041]
First, in step S61, the engine rotational speed Ne detected by the engine speed sensor S ₂ as compared to the engine stall judgment rotation speed NCR, a Ne ≧ NCR if the operating state the engine E, in step S62, the capacitor remaining by subtracting the capacitor 3 capacity QCAPIDL required to start the engine E from the remaining capacity QCAP of the capacitor 3 detected by the capacitive sensor S _7, and calculates the margin QCAPABL remaining capacity of the capacitor 3. In step S63, the 12-volt system power consumption integrated value DVPSUM is set to zero.
[0042]
On the other hand, if the engine E is stopped in the step S61, in step S64, 12-volt power sensor S 12-volt power consumption instantaneous value detected in ₈ DVP (i.e. instantaneous power taken out of the auxiliary battery 4 Value) is added to the previous value DVPSUM (n-1) of the 12-volt system power consumption integrated value DVPSUM to calculate the current value DVPSUM (n) of the 12-volt system power consumption integrated value DVPSUM. In step S65, the 12-volt system power consumption integrated value DVPSUM (n) calculated in step S64 is multiplied by the unit conversion coefficient KDVP to calculate the 12-volt system power consumption integrated value conversion result QDVP.
[0043]
In subsequent step S66, the remaining capacity QCAPABL of the capacitor 3 calculated in step S62 is compared with the 12-volt system power consumption integrated value conversion result QDVP calculated in step S65. When the engine E is stopped, the capacitor 3 is no longer charged, and the 12 volt system power consumption (that is, the 12 volt system power consumption integrated value conversion result QDVP) is taken out of the capacitor 3, so that the remaining capacity QCAP of the capacitor 3 gradually increases. Decrease.
[0044]
Thus, if the 12 volt system power consumption integrated value conversion result QDVP is less than the remaining capacity QCAPABL of the capacitor 3 in step S66, that is, the remaining capacity QCAP of the capacitor 3 is the capacitor 3 required for starting the engine E. If the capacity QCAPIDL is exceeded, it is determined that the engine E can be started with the electric power of the capacitor 3, and the capacitor remaining capacity determination flag F is determined in step S67. Set FCMGCAP to “1” to allow execution of idle engine stop control. On the other hand, if the 12 volt system power consumption integrated value conversion result QDVP is equal to or larger than the remaining capacity QCAPABL of the capacitor 3 in step S66, that is, the remaining capacity QCAP of the capacitor 3 is the capacity of the capacitor 3 required for starting the engine E. If it is less than or equal to QCAPIDL, it is determined that there is a possibility that the engine E cannot be started by the electric power of the capacitor 3, and the capacitor remaining capacity determination flag F is determined in step S68. FCMGCAP is set to “0” to prohibit execution of idle engine stop control.
[0045]
As described above, the permission and prohibition of the execution of the idle engine stop control are determined while monitoring the remaining capacity QCAP of the capacitor 3 that drives the starter motor 7, and therefore the remaining capacity QCAP of the capacitor 3 is insufficient and the engine E cannot be started. It is possible to reduce the fuel consumption by maximally executing the idle engine stop control while reliably avoiding the above.
[0046]
FIGS. 11 to 14 show a second embodiment of the present invention, FIG. 11 is an overall configuration diagram of a hybrid vehicle equipped with a manual transmission, FIG. 12 is a first part of a flowchart of a main routine, and FIG. FIG. 14 is a time chart showing an example of idle engine stop control.
[0047]
The hybrid vehicle of the first embodiment shown in FIG. 1 is provided with an automatic transmission Ta, whereas the hybrid vehicle of the second embodiment shown in FIG. 11 is provided with a manual transmission Tm. Further, the electronic control unit 1 of the hybrid vehicle of the second embodiment includes a signal from the clutch switch S ₅ that detects the operation of the clutch pedal 9 and a throttle opening sensor S ₆ that detects the opening of the throttle valve 10. Signal. Configurations other than those described above are the same as in the first embodiment.
[0048]
Next, specific contents of the idle engine stop control of the second embodiment will be described based on the flowcharts of FIGS. 12 and 13.
[0049]
First, when the starter switch is OFF in step S21, that is, when the engine is not started by the driver, the starter switch OFF → ON determination flag F in step S22. The state of FCMGST is determined. Starter switch OFF → ON judgment flag F when the ignition switch is turned ON The initial value of FCMGST is “0”. After that, when the engine is started by the driver in step S21 and the starter switch is turned on, the starter switch OFF → ON determination flag F in step S34. FCMGST is set to “1” and remains set to “1” until the ignition switch is turned off.
[0050]
Accordingly, since the driver turns on the ignition switch and turns on the starter switch, the answer to step S22 is “0”, and the process proceeds to step S33 through step S23. Therefore, the engine start in step S31 described later is performed. Is never executed. That is, in this vehicle, as described later, the engine stop during idle operation and the subsequent engine start are performed regardless of the operation of the starter switch by the driver, but the driver first turns on the starter switch to run the vehicle. Unless indicated by intention, the engine E is not automatically started, thereby avoiding useless engine start and saving fuel consumption.
[0051]
Thus, when the driver turns on the starter switch in step S21, the starter switch OFF → ON determination flag F in step S34. FCMGST is set to “1”, and a vehicle speed determination flag F described later in step S35. After the FCMGV is set to “0”, the process proceeds to step S30. In step S30, the comparison engine speed Ne detected by the engine speed sensor S ₂ is the engine stall judgment rotation speed NCR, if a Ne <NCR in the engine E is stopped, the starter motor 7 at step S31 It starts automatically and starts engine E. As a result, when the engine E starts and Ne ≧ NCR, the engine start in step S31 is passed and the process proceeds to step S33.
[0052]
Subsequently, in step S33, an idle engine stop control execution flag F Set FCMG to "0". Idle engine stop control execution flag F The FCMG is used to identify whether or not the engine E is to be stopped during idle operation. When it is set to “0”, the fuel supply is resumed following the fuel cut and the engine E is idle. Although the operation state is maintained, when it is set to “1”, the restart of the fuel supply following the fuel cut is prohibited, and the engine E is stopped without performing the idle operation. The idle engine stop control execution flag F The FCMG is set to “1” in step S42 when a predetermined condition to be described in detail later is satisfied.
[0053]
When the starter switch is turned off after the driver turns on the starter switch and starts the engine E in step S21, the starter switch OFF → ON determination flag F is already set in step S22. Since FCMGST is set to "1", the process proceeds to step S24 and the vehicle speed determination flag F The state of the FCMGV is determined. Vehicle speed judgment flag F FCMGV, immediately after the vehicle has started moving are set to "0", at the next step S25, the vehicle speed V detected by the vehicle speed sensor S ₁ is predetermined vehicle speed (e.g., 15km / h) becomes equal to or larger than, the step S26 With vehicle speed judgment flag F FCMGV is set to “1”. Therefore, unless the vehicle speed V exceeds 15 km / h in step S25, the process always proceeds to step S33 and the idle engine stop control execution flag F Since FCMG is set to “0” and the idle engine stop control is stopped, the idle engine stop control is not executed.
[0054]
The meaning is as follows. When the vehicle repeats low speed running and stopping at short time intervals during traffic jams, etc., the engine E stops and restarts every time the shift lever is operated between the neutral position and the forward running position with the clutch pedal 9 depressed. If it is assumed that it will be repeated, smooth running may not be possible. However, the above problem can be solved by prohibiting the execution of the idle engine stop control when the vehicle speed V is less than 15 km / h.
[0055]
In subsequent step S43, the vehicle is detected to be in the deceleration state by the reduction state detecting means M1 proceeds to step S27, the clutch switch S ₅ not clutch pedal 9 is depressed in step S27 is OFF If this is the case, that is, if the clutch is in the engaged state, the process proceeds to step S37 to execute idle engine stop control. The step when the have clutch switch S ₅ and the clutch pedal 9 is depressed is turned ON at step S27 (clutch disengaged state), is and shift position detected by the shift position sensor S ₃ in step S28 is in the neutral position proceeds to S36, where the throttle opening TH detected by the throttle opening degree sensor S ₆ is less than the throttle full-closed THIDLE, the process proceeds to step S37 to execute the idling engine stop control.
[0056]
On the other hand, even in the clutch disengaged state the clutch switch S ₅ is not ON at step S27, if the shift position is in-gear state (forward drive position or reverse drive position) in step S28, executes the idling engine stop control Without proceeding to step S29, an engine restart delay timer tmFCMG, which will be described later, is set. There also is in a clutch disengaged state the clutch switch S ₅ in the step S27 is not turned ON, and there the shift position is in the neutral position at step S28, further throttle opening TH is in the throttle full-closed THIDLE more in step S36 In this case, the process proceeds to step S29 without executing the idle engine stop control.
[0057]
The meaning is as follows. Clutch contact state where the clutch switch S ₅ is turned OFF, since the vehicle is in a state of waiting for a signal, such as if stopped, by stopping the engine E without idling, the stop frequency of the engine E It can be maximized to save fuel consumption. Also if the shift position is neutral in the clutch disengaged state where the clutch switch S ₅ is turned ON, also the driver determines that no intention to drive the vehicle, fuel consumption by stopping the engine E in the same manner as described above The amount can be saved.
[0058]
However, if the throttle opening TH is equal to or greater than the throttle fully closed opening THIDLE in step S36, that is, if the driver is stepping on the accelerator pedal, the above-described idle engine stop control is not executed. This is because when the vehicle is downshifted with a manual transmission Tm, in order to smoothly engage the clutch after the downshift, the engine speed is reduced by temporarily depressing the accelerator pedal with the clutch pedal 9 depressed. Ne may be increased. In such a case, since the idle engine stop control is being executed, if the engine speed Ne does not increase even if the accelerator pedal is depressed, there is a possibility that the shift-down operation cannot be performed smoothly. However, in this embodiment, when the accelerator pedal is depressed, the idle engine stop control is stopped. Therefore, when the accelerator pedal is depressed, the engine speed Ne can be increased and the downshift operation can be performed smoothly.
[0059]
In addition, when starting a vehicle that is stopped while the idle engine stop control is being executed, the engine E automatically starts when the shift lever is in-geared by stepping on the clutch pedal 9, but the accelerator is activated prior to the operation. Since the engine E can be started by stepping on the pedal, the vehicle can be started smoothly by starting the engine E before the in-gear.
[0060]
If the clutch switch 9 is turned off in step S27, or if the throttle opening TH is less than the throttle fully closed opening THIDLE in step S36, the remaining capacity of the capacitor is determined in step S37 before the idle engine stop control is executed. Flag F The state of FCMGCAP is determined.
[0061]
Capacitor remaining capacity determination flag F The FCMGCAP is used to identify whether or not the remaining capacity of the electric power stored in the capacitor 3 is sufficient to restart the stopped engine E. In step S37, the remaining capacity determination flag F If FCMGCAP is set to “1”, it is determined that the remaining capacity of the capacitor 3 is sufficient to restart the engine E, and after setting an engine restart delay timer tmFCMG described later in step S41, In S42, the idle engine stop control execution flag F Set FCMG to "1". Capacitor remaining capacity determination flag F Since the set of FCMGCAP is the same as that described with reference to FIG. 9 of the first embodiment, the overlapping description is omitted.
[0062]
As a result, the fuel supply control means 6 prohibits the resumption of fuel supply following the fuel cut, so that the engine E is stopped when the engine speed Ne decreases to the idle speed. On the other hand, in step S37, the capacitor remaining capacity determination flag F If FCMGCAP is set to “0”, it is determined that the remaining capacity of the capacitor 3 is not sufficient to restart the engine E, and an idle engine stop control execution flag F is determined in step S33. FCMG is set to “0”. As a result, the fuel supply control means 6 resumes the fuel supply following the fuel cut as usual, so that the idling operation is permitted when the engine speed Ne decreases to the idle speed.
[0063]
As described above, as when the clutch switch S ₅ is in the OFF state (the clutch contact state), to the time the clutch switch S ₅ is in the ON state (a clutch disengaged state), where and the shift position is in the neutral state, the engine Since E is stopped without idling, it is possible to minimize unnecessary idling of the engine E and minimize fuel consumption. However, as described above, when the vehicle speed V is less than 15 km / h, when the accelerator pedal is depressed, and when the remaining capacity of the capacitor 3 is not sufficient to restart the engine E, The execution of the idle engine stop control is prohibited.
[0064]
By the way, if the remaining capacity of the capacitor 3 is not sufficient to restart the engine E in step S37, and the engine E is in a stopped state at step S30, the starter motor 7 is driven in step S31. And the engine E is restarted before it is actually not restartable. However, when the engine E is restarted, there is a problem that a large load is applied to the starter motor 7 when the clutch is in the connected state and the shift position is in the in-gear state.
[0065]
In step S38, it is determined whether the shift position is neutral or in-gear. If in-gear, the engine restart delay timer tmFCMG is set in step S40, and the process proceeds to step S33. Thereby, restart of the engine E in the in-gear state in step S31 can be avoided, and a large load can be prevented from being applied to the starter motor 7. Even if the shift position is neutral in step S38, only when the neutral state continues in step S39 until a predetermined time (for example, 2 seconds) counted by the engine restart delay timer tmFCMG elapses. The restart of the engine E in step S31 is allowed. Thereby, the engine E is restarted only when the shift position is surely neutral, and it is possible to prevent an overload from acting on the starter motor 7.
[0066]
FIG. 14 is a time chart showing an example of idle engine stop control.
[0067]
Pressing the brake pedal driver at the time t ₁ during cruising of the vehicle releases the accelerator pedal, the fuel cut is executed by the fuel supply control means 6, the vehicle speed V gradually decreases. When the time t ₂ Oite engine speed Ne is close to idle speed, the driver is a shift position to the neutral stepping on the clutch pedal 9, the idle engine stop control execution flag F Since FCMG is already set to “1” and the fuel supply from the fuel cut is not resumed, the engine E stops without performing the idle operation. Thereafter, when the driver depresses the clutch pedal 9 to shift the vehicle to the in-gear state at time t ₃ to start the vehicle, the idle engine stop control execution flag F At the same time that FCMG is set to “0”, the fuel cut by the fuel supply control means 6 is completed, the fuel supply is resumed, and the engine E is started. And Thus, when connecting the clutch at time t ₄ the vehicle may be starting.
[0068]
As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.
[0069]
For example, in the embodiment, a hybrid vehicle using the engine E and the motor M as a driving source for traveling is illustrated, but the present invention can also be applied to a vehicle using only the engine E as a driving source for traveling.
[0070]
Further, the automatic transmission Ta of the first embodiment is not limited to the stepped type, and may be a stepless type (CVT).
[0071]
In the embodiment, the engine E is stopped without returning the fuel supply following the fuel cut. However, the engine E can be stopped by setting the target engine speed to a lower speed than the idle speed. In addition to the control of the fuel supply amount, ignition control can be used in combination.
[0072]
Further, the travel motor M can be used as a starter motor without providing a special starter motor 7 for starting the engine E. Furthermore, the engine starting means of the present invention is not limited to the starter motor 7 and the motor M, and includes a case of so-called “push” in which the engine E is started using the kinetic energy of the running vehicle. For example, this corresponds to the case where the engine E is started in step S12 of the flowchart of FIG. 8 when the vehicle speed V is less than 15 km / h in step S7 of the flowchart of FIG.
[0073]
The engine starting power source is not limited to the capacitor 3 and may be a rechargeable battery.
[0074]
【The invention's effect】
As described above, according to the first aspect of the present invention, after the fuel supply to the engine is interrupted when the vehicle is decelerated , the remaining capacity of the engine starting power source can operate the engine starting means to start the engine. if the predetermined volume or more, and determines that it is possible restarted even to stop the engine, the engine is automatically stopped to be able to save fuel consumption, while the power for starting the engine during operation of the engine If the remaining capacity is less than the predetermined capacity, it is determined that there is a possibility that the engine cannot be restarted when the engine is stopped, and the engine can be continuously driven.
[0075]
On the other hand, after the engine is automatically stopped, the deviation is calculated by subtracting the predetermined capacity from the remaining capacity of the engine starting power source when the engine is automatically stopped, and the integrated value of power consumption after the engine is automatically stopped As a result, if the deviation is larger than the integrated value, it is determined that the engine can still be restarted, and the engine can be kept stopped to save fuel consumption. If the deviation is less than or equal to the integrated value, it can be determined that the engine cannot be restarted unless the engine is started early, and the engine can be started by operating the engine starting means.
[0076]
In this way, by stopping and starting the engine while monitoring whether or not the engine starting power source has sufficient power to start the engine, the engine stop time is extended as much as possible to reduce the fuel consumption. While reducing, it is possible to reliably avoid the engine from being unable to start.
[Brief description of the drawings]
1 is an overall configuration diagram of a hybrid vehicle equipped with an automatic transmission. FIG. 2 is an explanatory diagram of a cruise / idle mode. FIG. 3 is an explanatory diagram of an acceleration mode. FIG. 4 is an explanatory diagram of a deceleration mode. FIG. 6 is a graph corresponding to a claim. FIG. 7 is a first part of a flowchart of the main routine. FIG. 8 is a second part of a flowchart of the main routine. FIG. 10 is a time chart showing an example of idle engine stop control. FIG. 11 is an overall configuration diagram of a hybrid vehicle equipped with a manual transmission. FIG. 12 is a first part of a flowchart of the main routine. FIG. 13 is a second part of the flowchart of the main routine. Description of the sign is a time chart showing an example of a dollar engine stop control
DVP 12-volt power consumption instantaneous value (power consumption)
E Engine M Motor (generator)
Remaining capacity of QCAP capacitor (Remaining capacity of power supply for starting engine)
Capacitor capacity required to start the QCAPIDL engine (predetermined capacity)
QCAPABL Capacitance remaining capacity (deviation)
QDVP Power consumption integrated value S ₇ Capacitor remaining capacity sensor (starting power remaining capacity detection means)
S ₈ 12-volt power consumption sensor (power consumption detection means)
M1 Deceleration state detection means M2 Engine output control means 3 Capacitor (engine starting power supply)
6 Fuel supply control means 7 Starter motor (engine starting means)

Claims (1)

Engine (E),
Engine starting means (7) for starting the engine (E);
An engine starting power source (3) that supplies electric power to the engine starting means (7) and auxiliary equipment other than the engine starting means (7) and is charged by a generator (M) driven by the engine (E) )When,
Starting power remaining capacity detecting means (S ₇ ) for detecting the remaining capacity (QCAP) of the engine starting power supply (3);
Power consumption detection means (S ₈ ) for detecting power consumption (DVP) taken from the engine starting power supply (3);
Fuel supply control means (6) for controlling fuel supply to the engine (E);
Deceleration state detection means (M1) for detecting the deceleration state of the vehicle;
Engine output control means (M2) including means for shutting off the fuel supply to the engine (E) by the fuel supply control means (6) when the deceleration state detection means (M1) detects the deceleration state of the vehicle. Become
The engine output control means (M2), after interruption of the fuel supply by the fuel supply control means when the vehicle deceleration (6), the remaining capacity of the starting power remaining capacity detection means engine starting power supply (3) by (S ₇₎ (QCAP) is detected, and when the remaining capacity (QCAP) is less than a predetermined capacity (QCAPIDL) that can start the engine (E) by operating the engine starting means (7) , the engine (E) is driven. On the other hand, when the remaining capacity (QCAP) is equal to or greater than the predetermined capacity (QCAPIDL), the engine (E) is automatically stopped ,
After the automatic stop of the engine (E),
An engine (E) is obtained by subtracting the predetermined volume (QCAPIDL) from the remaining capacity of the engine starting power supply (3) when the automatic stop (QCAP) Deviation (QCAPABL), the engine (E) is from automatically stopped The integrated value (QDVP) of the power consumption (DVP) is compared. If the deviation (QCAPABL) is larger than the integrated value (QDVP) as a result, the engine (E) is maintained in a stopped state and the deviation ( An engine automatic stop / start control device for a vehicle, wherein if QCAPABL) is equal to or less than the integrated value (QDVP), the engine (E) is started by the engine starting means (7).

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