JP2017067205A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle which can stop an engine by idling stop control at a time point when a vehicle speed is lowered to an idling stop execution vehicle speed irrespective of a deceleration degree of the vehicle.SOLUTION: In idling stop control, an engine is stopped in response to the establishment of an engine stop condition. The engine stop condition includes a condition that a vehicle speed is lowered to an idling stop execution vehicle speed or lower. Prior to a stop of the engine by the idling stop control, downshift control for lowering a gear change stage of an automatic transmission to a first speed stage is performed. At the execution of the downshift control, the start timing of the downshift control is determined so that the vehicle speed is lowered to the idling stop execution vehicle speed after the lapse of a prescribed downshift control time which is necessary for the downshift control after a start of the down shit control irrespective of a deceleration degree of a vehicle.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control device for a vehicle equipped with an automatic transmission.

  In recent years, so-called idling stop control has been widely adopted in vehicles using an engine as a drive source for the purpose of improving fuel efficiency. In the idling stop control, for example, the engine is automatically stopped when the brake pedal is depressed with the driver's foot, the brake is activated, and the vehicle speed drops below a predetermined idling stop execution vehicle speed (for example, about 10 km / h). The idling stop state. After the engine is automatically stopped, for example, when the foot is released from the brake pedal and the brake is released, the engine is automatically restarted.

  Some vehicles that employ idling stop control include a stepped automatic transmission (AT) as a transmission. In this model, in order to achieve quick acceleration when returning from the idling stop state (engine restart), if the automatic transmission is in a gear other than the first gear before the engine is automatically stopped, Downshift from the gear stage to the first gear stage.

  FIG. 6 is a diagram illustrating an example of temporal changes in vehicle speed, engine speed, and turbine speed before and after the start of idling stop in a conventional vehicle. FIG. 7 is a diagram illustrating another example of a temporal change in vehicle speed, engine speed, and turbine speed before and after the start of idling stop in a conventional vehicle.

  When the vehicle speed is reduced to a predetermined downshift vehicle speed while the vehicle is decelerating at the third speed, the automatic transmission starts a downshift from the third speed to the first speed (time T61). For this downshift, for example, one of the frictional engagement elements provided in the automatic transmission is switched from the engaged state to the released state. Switching from the engaged state to the released state of the friction engagement element is achieved by removing the hydraulic pressure from the friction engagement element. Therefore, the downshift control time sufficient for the hydraulic pressure to be released from the friction engagement element is set, and the engine is controlled by the idling stop control from the start of the downshift until the downshift control time elapses (time T61-T62). Automatic stop is prohibited.

  When the vehicle speed decreases moderately, as shown in FIG. 6, after the downshift control time has elapsed from the start of the downshift, the vehicle speed decreases to the idling stop execution vehicle speed (time T63), and the engine is controlled by the idling stop control. It is automatically stopped.

  However, when the vehicle speed is sharply decreased, as shown in FIG. 7, the vehicle speed decreases to the downshift vehicle speed (time T71), and the automatic transmission downshifts from the third gear to the first gear. The vehicle speed may decrease to the idling stop execution vehicle speed before the time point when the downshift control time elapses after the start (time T73). In this case, even if the vehicle speed drops to the idling stop execution vehicle speed, the engine is not automatically stopped by the idling stop control, and the engine is automatically stopped by the idling stop control when the downshift control time has elapsed from the start of the downshift. (Time T72).

  For this reason, when the vehicle speed is drastically reduced (when the vehicle deceleration is large), the engine is driven even when the vehicle speed drops below the idling stop execution vehicle speed, thereby improving the fuel efficiency by the idling stop control. There is a risk that the effect may fade.

Japanese Patent Application Laid-Open No. 2015-117738

  An object of the present invention is to provide a vehicle control device that can stop an engine by idling stop control when the vehicle speed drops to the idling stop execution vehicle speed regardless of the deceleration of the vehicle.

  In order to achieve the above object, a vehicle control device according to the present invention is a control device used in a vehicle equipped with an engine and an automatic transmission that shifts and outputs power from the engine. Vehicle speed acquisition means for acquiring the vehicle speed, and engine stop in response to establishment of an engine stop condition including one of the conditions that the vehicle speed acquired by the vehicle speed acquisition means has fallen below the predetermined idling stop execution vehicle speed The idling stop control means for executing the idling stop control and the downshift control for reducing the gear ratio of the automatic transmission to a predetermined gear ratio before the engine is stopped by the idling stop control means while the vehicle is decelerating. Downshift control means for performing downshift control from a start of downshift control to a predetermined downshift required After the control time has elapsed, as the vehicle speed obtained by the vehicle speed acquisition means is reduced to an idling stop performed vehicle speed, and a start timing determining means for determining a start timing of the downshift control.

  According to this configuration, in the idling stop control, the engine is stopped in response to the establishment of the engine stop condition. The engine stop condition includes at least a condition that the vehicle speed has dropped below a predetermined idling stop execution vehicle speed.

  Prior to engine stop by idling stop control, downshift control is executed to reduce the gear ratio of the automatic transmission to a predetermined gear ratio. Thereby, when the engine is restarted, the automatic transmission constitutes a predetermined gear ratio, so that the vehicle can be accelerated (started) quickly.

  When executing the downshift control, the start timing of the downshift control is determined so that the vehicle speed decreases to the idling stop execution vehicle speed after a predetermined downshift control time required for the downshift control has elapsed from the start of the downshift control. Is done. Therefore, even if the vehicle speed drops to the idling stop vehicle speed, the downshift control is not continued, and it is avoided that the engine stop by the idling stop control is prohibited because the downshift control is continued. it can. Therefore, if conditions other than the vehicle speed in the engine stop condition are satisfied, the engine can be stopped immediately in response to the vehicle speed decreasing to the idling stop execution vehicle speed. As a result, it is possible to satisfactorily ensure the effect of improving fuel consumption by the idling stop control.

  The time from the start of the downshift control until the vehicle speed decreases to the idling stop execution vehicle speed is shorter as the deceleration of the vehicle is larger. Therefore, the start timing of the downshift control is determined to be earlier as the vehicle deceleration is larger. When the vehicle deceleration is large, the driver intends to decelerate the vehicle suddenly, so the downshift control is started at an early timing and the engine brake is activated early because the gear ratio of the automatic transmission is lowered. However, the impact on drivability is small.

  Therefore, regardless of vehicle deceleration, the engine can be stopped by idling stop control when the vehicle speed drops to the idling stop execution speed while ensuring drivability, and the effect of improving fuel efficiency by idling stop control is ensured. can do.

  The automatic transmission may be a stepped automatic transmission.

  When the automatic transmission is a stepped automatic transmission, the predetermined gear ratio may be a gear ratio of the first gear. That is, when the automatic transmission is a stepped automatic transmission, the downshift control may be a control for downshifting the shift stage of the automatic transmission from a shift speed other than the first speed to the first speed. .

  The automatic transmission is a stepped automatic transmission. When one of the frictional engagement elements provided in the automatic transmission is switched from the engaged state to the released state, the automatic transmission is changed from a gear stage other than the first gear stage. The structure which switches to 1st gear stage may be sufficient.

  In this case, the downshift control time may be the time required for the friction engagement element to switch from the engagement state to the release state, and in order to ensure that the residual oil is removed from the friction engagement element at that time. It is also possible to add the extra time.

  The downshift control means starts the downshift control in response to the vehicle speed acquired by the vehicle speed acquisition means decreasing to the downshift vehicle speed, and the start timing determining means is necessary for the downshift control from the start of the downshift control. After the predetermined downshift control time has elapsed, the downshift control start timing is determined by variably setting the downshift vehicle speed so that the vehicle speed acquired by the vehicle speed acquisition means decreases to the idling stop execution vehicle speed. It may be configured to.

  In this case, when the deceleration obtained from the vehicle speed acquired by the vehicle speed acquisition unit is equal to or greater than a predetermined value, the start timing determination unit sets the downshift vehicle speed to be variable, and the deceleration is less than the predetermined value. Alternatively, the downshift vehicle speed may be set to a fixed value.

  According to the present invention, the engine can be stopped by the idling stop control at the time when the vehicle speed is reduced to the idling stop execution vehicle speed while ensuring drivability regardless of the deceleration of the vehicle. As a result, it is possible to secure both the drivability and the effect of improving the fuel consumption by the idling stop control.

It is a figure which shows the structure of the principal part of the vehicle by which the control apparatus which concerns on one Embodiment of this invention is mounted. It is a flowchart which shows the flow of the process for determining execution of downshift control. It is a flowchart which shows the flow of a downshift vehicle speed setting process. It is a figure which shows an example (example in case deceleration is small) of the time change of the vehicle speed before and behind idling stop start, an engine speed, and a turbine speed. It is a figure which shows the other example (example in case deceleration is large) of the time change of the vehicle speed before and behind idling stop start, an engine speed, and a turbine speed. It is a figure which shows an example (example in case deceleration is small) of the time change of the vehicle speed before and behind the idling stop start in the conventional vehicle, an engine speed, and a turbine speed. It is a figure which shows the other example (example in case deceleration is large) of the time change of the vehicle speed before and behind the idling stop start in the conventional vehicle, an engine speed, and a turbine speed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Vehicle configuration>
FIG. 1 is a diagram illustrating a configuration of a main part of a vehicle 1 on which a control device according to an embodiment of the present invention is mounted.

  The vehicle 1 is an automobile that uses the engine 2 as a drive source.

  The output of the engine 2 is transmitted to driving wheels (for example, left and right front wheels) of the vehicle 1 via the torque converter 3 and the automatic transmission 4. The engine 2 is provided with an electronic throttle valve for adjusting the amount of intake air into the combustion chamber of the engine 2, an injector (fuel injection device) that injects fuel into the intake air, and an ignition plug that generates electric discharge in the combustion chamber. It has been. The engine 2 is also provided with a starter for starting the engine 2. The automatic transmission 4 is a stepped automatic transmission.

  The vehicle 1 includes a plurality of ECUs (Electronic Control Units) having a configuration including a CPU, a ROM, a RAM, and the like. The ECU includes an engine ECU 11, an ATECU 12, a brake ECU 13, and an IDS (idling stop) ECU 14. The plurality of ECUs are connected so as to be capable of bidirectional communication using a CAN (Controller Area Network) communication protocol.

  An accelerator sensor 21 and an engine speed sensor 22 are connected to the engine ECU 11.

  The accelerator sensor 21 inputs a signal corresponding to an operation amount of an accelerator pedal (not shown) to the engine ECU 11. Based on the signal input from the accelerator sensor 21, the engine ECU 11 sets the ratio of the operation amount to the maximum operation amount of the accelerator pedal, that is, 0% when the accelerator pedal is not depressed, and the accelerator pedal is depressed to the maximum. The accelerator opening, which is a percentage with the time as 100%, is calculated.

  The engine speed sensor 22 inputs a pulse signal synchronized with the rotation of the engine 2 (rotation of the crankshaft) to the engine ECU 11. The engine ECU 11 converts the frequency of the pulse signal input from the engine speed sensor 22 into the speed of the engine 2 (engine speed).

  The engine ECU 11 is an electronic device provided in the engine 2 for starting, stopping and adjusting the output of the engine 2 based on numerical values obtained from signals inputted from various sensors and various information inputted from other ECUs. Control throttle valves, injectors and spark plugs.

  A shift position sensor 23, a turbine speed sensor 24, and the like are connected to the ATECU 12.

  The shift position sensor 23 inputs a signal corresponding to the position of the shift lever (select lever) to the ATECU 12. As positions of the shift lever, for example, a P position, an R position, an N position, and a D position are provided. The P position, the R position, the N position, and the D position correspond to the P range (parking range), R range (reverse range), N range (neutral range), and D range (forward range), respectively. The shift lever can be shifted between the P position, the R position, the N position, and the D position, and the shift range can be instructed by the shift operation.

  The turbine speed sensor 24 inputs a pulse signal synchronized with the rotation of the turbine runner of the torque converter 3 to the ATECU 12. The ATECU 12 converts the frequency of the pulse signal input from the turbine rotation speed sensor 24 into a turbine rotation speed that is the rotation speed of the turbine runner.

  The ATECU 12 is based on numerical values obtained from signals inputted from various sensors and various information inputted from other ECUs, etc., and the vehicle running state (speed stage, throttle opening, vehicle speed, turbine speed, shift position). Etc.) and a valve included in the hydraulic circuit 25 for supplying hydraulic pressure to each part of the automatic transmission 4 (see FIG. (Not shown).

  A brake sensor 26 and a vehicle speed sensor 27 are connected to the brake ECU 13.

  The brake sensor 26 outputs a signal corresponding to the amount of operation of the brake pedal disposed in the vehicle interior, and the brake ECU 13 acquires the amount of operation of the brake pedal based on the signal input from the brake sensor 26. .

  The vehicle speed sensor 27 includes, for example, a rotor made of a magnetic material that rotates as the vehicle 1 travels, and an electromagnetic pickup provided in non-contact with the rotor. Each time the rotor rotates by a certain angle, a pulse signal is output from the electromagnetic pickup, and the pulse signal is input to the brake ECU 13. Since the frequency of the pulse signal corresponds to the vehicle speed, the brake ECU 13 can obtain the frequency of the pulse signal input from the vehicle speed sensor 27 by converting it to the vehicle speed.

  The brake ECU 13 controls the brake actuator 28 and the like based on the amount of operation of the brake pedal, the vehicle speed of the vehicle 1, various information input from other ECUs, etc., and the vehicle 1 is kept in a stable posture. The braking force applied to each wheel from each brake is controlled so that the vehicle 1 is braked.

  The vehicle 1 has an idling stop function. The IDSECU 14 performs idling stop control that is control for the idling stop function. As information necessary for the idling stop control, information such as the vehicle speed and the operation amount of the brake pedal is input to the IDSECU 14 from the brake ECU 13.

  In the idling stop control, when the brake pedal is operated (depressed) while the vehicle 1 is traveling, the IDSECU 14 repeatedly determines whether or not a predetermined engine stop condition is satisfied. The engine stop condition is, for example, a condition that the vehicle speed is a predetermined idling stop execution vehicle speed (for example, 10 km / h) or less and the brake pedal is operated for a certain time or more. When the engine stop condition is satisfied, an IDS request is output from the IDSECU 14 to the engine ECU 11, and the engine 2 is automatically stopped by the engine ECU 11.

  While the engine 2 is automatically stopped by the idling stop control, it is repeatedly determined whether or not a predetermined engine restart condition is satisfied. The engine restart condition is, for example, a condition that the operation of the brake pedal is released (the driver's foot is released from the brake pedal) while the engine 2 is automatically stopped. When the restart condition is satisfied, the IDSECU 14 outputs a restart request to the engine ECU 11, and the engine ECU 11 restarts the engine 2.

<Downshift control>
In the vehicle 1, before the engine 2 is automatically stopped by the idling stop control, when the shift stage of the automatic transmission 4 is other than the first speed stage, the automatic transmission 4 is controlled by downshift control before the engine 2 is automatically stopped. The gear stage is downshifted from a gear stage other than the first gear to the first gear.

  FIG. 2 is a flowchart showing a flow of processing for determining execution of downshift control.

  In order to determine execution of the downshift control, the ATECU 12 repeatedly executes the process shown in FIG. 2 while the vehicle 1 is traveling.

  In the process shown in FIG. 2, it is determined whether or not the vehicle 1 is traveling at a reduced speed (step S1).

  When the vehicle 1 is traveling at a reduced speed (YES in step S1), it is determined whether or not the shift stage of the automatic transmission 4 is a shift stage other than the first speed stage (step S2).

  When the gear stage of the automatic transmission 4 is a gear stage other than the first gear stage (YES in step S2), a precondition for automatically stopping the engine 2 by the idling stop control (a precondition for idling stop execution) is satisfied. Is determined (step S3).

  The precondition for the idling stop is the remaining condition where the conditions related to the vehicle speed are omitted from the engine stop condition. That is, when the engine stop condition includes a condition that the vehicle speed is equal to or lower than a predetermined idling stop vehicle speed and a condition that the brake pedal is operated for a certain time or more, the precondition for idling stop is Is operated for a certain period of time.

  If the precondition for idling stop is satisfied (YES in step S3), a downshift vehicle speed setting process for setting the downshift vehicle speed is executed (step S4). By the downshift vehicle speed setting process, the downshift vehicle speed is variably set according to the deceleration of the vehicle 1. The downshift vehicle speed setting process will be described later.

  After the downshift vehicle speed setting process, it is determined whether or not the vehicle speed has decreased to the downshift vehicle speed (step S5).

  Until the vehicle speed decreases to the downshift vehicle speed, the processes of steps S1 to S5 described above are repeated.

  Then, when the vehicle 1 continues to decelerate, the speed of the automatic transmission 4 is a speed other than the first speed, and the vehicle speed decreases to the downshift speed while the precondition for idling stop is satisfied (step The execution of the downshift control is determined and the downshift control is started (step S6).

  In the downshift control, for example, a friction engagement element (engaged at a gear stage other than the first gear (a gear before downshifting to the first gear) and released to constitute the first gear ( Clutches and brakes) and the valves included in the hydraulic circuit 25 of the automatic transmission 4 are controlled, so that the hydraulic pressure is released from the target frictional engagement elements and the frictional engagement elements are engaged. To the released state. The minimum time required for switching the friction engagement element from the engaged state to the released state is substantially constant. Therefore, the downshift control time required for the downshift control is to ensure that the residual oil is removed from the frictional engagement element during the minimum time required for switching the frictional engagement element from the engaged state to the released state. Is set to a certain time including a margin time (a time necessary for reliably eliminating residual oil in the friction engagement element). When the downshift control time elapses from the start of the downshift control, the downshift control is terminated. From the start to the end of the downshift control, the automatic stop of the engine 2 by the idling stop control is prohibited.

  When the vehicle 1 is not traveling at a reduced speed (NO in step S1), the vehicle 1 is traveling at a reduced speed, but the shift stage of the automatic transmission 4 is the first speed (NO at step S2), or the vehicle 1 Is running at a reduced speed, and the speed of the automatic transmission 4 is a speed other than the first speed, but the precondition for idling stop is not satisfied (NO in step S3), downshift control is executed. Not.

  FIG. 3 is a flowchart showing the flow of the downshift vehicle speed setting process.

  In the downshift vehicle speed setting process, first, the deceleration of the vehicle 1 is calculated (step S41). The deceleration can be calculated, for example, by differentiating the vehicle speed with respect to time.

  Next, the downshift advance vehicle speed is calculated from the deceleration (step S42).

  Specifically, the amount of decrease in vehicle speed during the downshift control time is calculated by multiplying the deceleration and the downshift control time. Then, the amount of decrease is added to the idling stop execution vehicle speed, and the added value is calculated as the downshift advance vehicle speed. Thus, the greater the deceleration of the vehicle 1, the greater the amount of decrease in the vehicle speed during the downshift control time, so the downshift advance vehicle speed increases.

  Thereafter, it is determined whether the downshift advance vehicle speed is equal to or higher than the downshift normal vehicle speed (step S43). The downshift normal vehicle speed is a fixed value. When the deceleration of the vehicle 1 is less than a predetermined value, the normal downshift vehicle speed is set in advance so that the time required for the vehicle speed to decrease from the normal downshift vehicle speed to the idling stop vehicle speed is equal to or longer than the downshift control time. Has been.

  If the downshift advance vehicle speed is equal to or higher than the downshift normal vehicle speed (YES in step S43), the downshift advance vehicle speed is set to the downshift vehicle speed (step S44), and the downshift vehicle speed setting process is terminated. .

  On the other hand, if the downshift advance vehicle speed is less than the normal downshift vehicle speed (NO in step S43), the normal downshift vehicle speed is set to the downshift vehicle speed (step S45), and the downshift vehicle speed setting process is terminated. .

  FIG. 4 is a diagram illustrating an example of temporal changes in vehicle speed, engine speed, and turbine speed before and after the start of idling stop.

  From the content of the downshift vehicle speed setting process, when the deceleration of the vehicle 1 is less than a predetermined value, the normal downshift vehicle speed is set to the downshift vehicle speed. In this case, the vehicle speed of the vehicle 1 that is traveling at a reduced speed is reduced to the downshift vehicle speed (downshift normal vehicle speed) and the downshift control is started (time T41) before the vehicle speed is reduced to the idling stop execution vehicle speed. After the downshift control time has elapsed (time T42), the downshift control is terminated. Therefore, after the downshift control is completed (after the downshift control time has elapsed from the start of the downshift control), the vehicle speed is reduced to the idling stop execution vehicle speed (time T43), and the engine 2 is automatically stopped by the idling stop control. The

  FIG. 5 is a diagram illustrating another example of the temporal change of the vehicle speed, the engine speed, and the turbine speed before and after the start of the idling stop.

  From the content of the downshift vehicle speed setting process, when the deceleration of the vehicle 1 is equal to or greater than a predetermined value, the downshift advance vehicle speed is set to the downshift vehicle speed. As a result, the vehicle speed of the vehicle 1 that is traveling at a reduced speed is reduced to the downshift vehicle speed (downshift first advance vehicle speed), and after the downshift control is started (time T51), before the vehicle speed decreases to the idling stop execution vehicle speed. After the downshift control time has elapsed (time T52), the downshift control is terminated. Therefore, after the end of the downshift control (after the downshift control time has elapsed from the start of the downshift control), the vehicle speed decreases to the idling stop execution vehicle speed (time T53), and the engine 2 is automatically stopped by the idling stop control. The

  Note that the start timing of the downshift control is a point in time when the vehicle speed decreases to the downshift vehicle speed, and varies according to the downshift vehicle speed. Therefore, the setting of the downshift vehicle speed is synonymous with the determination of the start timing of the downshift control.

<Effect>
As described above, in the idling stop control, the engine 2 is stopped in response to the establishment of the engine stop condition. The engine stop condition includes a condition that the vehicle speed has dropped below a predetermined idling stop execution vehicle speed.

  Prior to the engine 2 being stopped by the idling stop control, the downshift control for reducing the gear position of the automatic transmission 4 to the first gear is executed. As a result, when the engine 2 is restarted, the automatic transmission 4 constitutes the first gear, so that the vehicle 1 can be accelerated (started) quickly.

  When the downshift control is executed, the vehicle speed is reduced to the idling stop execution vehicle speed after a predetermined downshift control time required for the downshift control has elapsed since the start of the downshift control regardless of the deceleration of the vehicle 1. The start timing of the downshift control is determined. Therefore, even if the vehicle speed drops to the idling stop execution vehicle speed, the downshift control is not continued, and since the downshift control is continued, the stop of the engine 2 by the idling stop control is prohibited. Can be avoided. Therefore, if conditions other than the vehicle speed in the engine stop condition are satisfied, the engine 2 can be stopped immediately in response to the vehicle speed decreasing to the idling stop execution vehicle speed. As a result, it is possible to satisfactorily ensure the effect of improving fuel consumption by the idling stop control.

  The time from the start of the downshift control until the vehicle speed decreases to the idling stop execution vehicle speed is shorter as the deceleration of the vehicle 1 is larger. Therefore, the start timing of the downshift control is determined to be earlier as the deceleration of the vehicle 1 is larger. When the deceleration of the vehicle 1 is large, the driver intends to decelerate the vehicle 1 suddenly. Therefore, the downshift control is started at an early timing, and the engine brake caused by lowering the gear position of the automatic transmission 4 is early. Even if it operates, the effect on drivability is small.

  Therefore, the engine 2 can be stopped by the idling stop control when the vehicle speed is lowered to the idling stop execution vehicle speed while ensuring drivability regardless of the deceleration of the vehicle 1, and the effect of improving the fuel consumption by the idling stop control can be achieved. Can be secured.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, as an example of the engine stop condition, the condition that the brake pedal is depressed and the vehicle speed of the vehicle 1 is equal to or less than a predetermined idling stop vehicle speed is taken up, but the engine stop condition is not necessarily limited to the exemplified condition. Not. For example, a hydraulic pressure sensor that detects the hydraulic pressure generated by the brake master cylinder mounted on the vehicle is provided, and instead of the condition that the brake pedal is depressed, the hydraulic pressure detected by the hydraulic pressure sensor is equal to or higher than a predetermined pressure. The condition may be adopted. Further, other conditions than the exemplified conditions, for example, the condition that the charge amount of the battery mounted on the vehicle 1 is equal to or greater than a predetermined amount, and the steering angle (rotation angle from the neutral position) of the steering wheel is equal to or smaller than the predetermined angle. A condition such as “may be” may be added.

  In addition, the downshift control time is added to the time required for switching the frictional engagement element from the engaged state to the released state to the minimum necessary time to ensure that the residual oil is removed from the frictional engagement element. It is assumed that it is set to a certain time. This is merely an example, and the downshift control time may be set to a minimum time required for switching from the engaged state to the released state of the friction engagement element without adding a margin time.

  The automatic transmission 4 is not limited to a stepped automatic transmission, but may be a continuously variable automatic transmission (CVT).

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 4 Automatic transmission 12 ATECU (a control apparatus, a vehicle speed acquisition means, a downshift control means, a start timing determination means)
14 IDSECU (control device, idling stop control means)

Claims (1)

A control device used in a vehicle equipped with an engine and an automatic transmission that shifts and outputs power from the engine,
Vehicle speed acquisition means for acquiring the vehicle speed of the vehicle;
Idling stop control is executed to stop the engine in response to the establishment of an engine stop condition that includes one of the conditions that the vehicle speed acquired by the vehicle speed acquisition means falls below a predetermined idling stop execution vehicle speed. An idling stop control means;
Downshift control means for performing downshift control for reducing the gear ratio of the automatic transmission to a predetermined gear ratio before the engine is stopped by the idling stop control while the vehicle is decelerating;
The downshift control is performed such that the vehicle speed acquired by the vehicle speed acquisition means decreases to the idling stop execution vehicle speed after a predetermined downshift control time necessary for the downshift control has elapsed since the start of the downshift control. And a start timing determining means for determining the start timing of the vehicle.

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