JP2017096112A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle which can suppress a shock generated at a synchronization in which a turbine rotation number coincides with a synchronous rotation number while improving a start feeling.SOLUTION: Even if an accelerator pedal of a vehicle is operated before a clutch starts to possess a torque transmission capacity, an opening of an electronic throttle valve is set at 0% being a first opening until the clutch starts to possess the torque transmission capacity, and the throttle valve is left to be closed. After the clutch starts to possess the torque transmission capacity, the opening of the electronic throttle valve is raised to a second opening. By this constitution, torque which is outputted from an engine is raised, and acceleration rises by a start of the movement of the vehicle. The second opening is set at a constant opening at which the torque inputted into the clutch does not exceed the torque transmission capacity of the clutch.SELECTED DRAWING: Figure 9

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 (idling stop) when the brake pedal is depressed by the driver's foot, the brake is activated, and the vehicle speed is reduced to a predetermined idling stop execution vehicle speed or less. 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 (returned from the idling stop).

  Some vehicles that employ idling stop control include a stepped automatic transmission (AT) as a transmission. The automatic transmission is provided with a P range (parking range), an R range (reverse range), an N range (neutral range), and a D range (forward range). These ranges are selected by operating a shift lever disposed in the vehicle interior, and a clutch (brake) provided in the automatic transmission is engaged / released according to the selected range. Specifically, in the P range and the N range, all the clutches are released. In the R range, a specific clutch is engaged. In the D range, the clutch engaged in the R range is released, and a plurality of shift speeds are selectively configured by a combination of engagement and release of the other clutches. The clutch is engaged / released by hydraulic pressure.

  Since the mechanical oil pump driven by the engine power is stopped during idling stop, the hydraulic pressure is released from each clutch of the automatic transmission, and each clutch is released. Therefore, at the time of return from idling stop, a control device that controls the automatic transmission engages a clutch (for example, a clutch constituting the first gear when the shift lever is positioned at the D position corresponding to the D range). Engagement control is performed. Further, when returning from the idling stop, the electronic throttle valve of the engine is kept closed even if the driver depresses the accelerator pedal in order to suppress the blow-up of the rotation of the turbine runner of the torque converter.

  FIG. 10A and FIG. 10B are diagrams showing examples of changes over time in the turbine speed, the accelerator opening, the throttle opening, and the acceleration generated in the vehicle when returning from the idling stop.

  When the brake is released, the engine returns from the idling stop, so that the engine is cranked and clutch engagement control is started to supply hydraulic pressure to the clutch. When the engine is completely detonated, the engine speed increases, and the turbine speed, which is the speed of the turbine runner of the torque converter, starts to increase as the engine speed increases (time T101). Thereafter, when the filling of the oil into the clutch is completed, the piston for bringing the clutch plate and the clutch disc into pressure contact to generate a frictional force comes into contact with the clutch plate, and the clutch starts to engage while sliding (time T102). Thereafter, as the engagement of the clutch proceeds, the torque transmission capacity of the clutch increases and the turbine rotation speed decreases. When the engagement of the clutch is completed and the clutch no longer slips, the turbine rotation speed stops decreasing, and the turbine rotation speed is the first synchronous rotation speed (the output of the automatic transmission in the state where the first speed stage is configured). (The number of revolutions synchronized with the number of revolutions) (time T103).

  As shown in FIG. 10A, after the engagement of the clutch is completed, the electronic throttle valve is opened in response to the turbine rotational speed being equal to the first-speed synchronous rotational speed, and then the opening degree of the electronic throttle valve is set to the time. In the control that is gradually increased as time elapses, it takes a long time lag from when the accelerator pedal is depressed by the driver until the vehicle starts moving and acceleration starts up. Therefore, the start of the vehicle is delayed in response to the request of the driver who has depressed the accelerator pedal, and the start feeling given to the driver may be poor.

  Further, as shown in FIG. 10B, the electronic throttle valve is opened at the timing from when the clutch starts to be engaged until the engagement is completed (time T104), and then the opening of the electronic throttle valve has elapsed over time. In the control that is gradually increased along with the increase in the opening amount of the electronic throttle valve, the torque output from the engine increases, and the acceleration of the vehicle rises early. However, since the increase in the torque transmission capacity of the clutch cannot follow the increase in the torque and the turbine rotation speeds up, the vehicle acceleration due to the change in the turbine rotation speed is synchronized at the time when the turbine rotation speed coincides with the first-speed synchronous rotation speed Changes appear as a synchronous shock.

Japanese Patent Application Laid-Open No. 2015-117738

  An object of the present invention is to provide a vehicle control device that can suppress a synchronous shock that occurs at the time of synchronization in which the turbine rotational speed matches the synchronous rotational speed while improving the starting feeling.

  In order to achieve the above object, a vehicle control apparatus according to the present invention includes an engine, a torque converter, a hydraulic circuit and an engagement element that is engaged by hydraulic pressure supplied from the hydraulic circuit, and the power from the engine is received. A control device used in a vehicle equipped with an automatic transmission that is input via a torque converter, and controls engagement of an engagement element by controlling a hydraulic circuit when the engine is started. The throttle valve provided in the engine is closed until the engagement control means to be executed and the engagement element starts to have a torque transmission capacity by the engagement control. After the engagement element starts to have the torque transmission capacity, the throttle valve And a throttle control means for increasing the torque input to the engagement element to a constant opening that does not exceed the torque transmission capacity of the engagement element.

  According to this configuration, when the engine is started, the engagement control for engaging the engagement element of the automatic transmission is executed. When the filling of the oil into the engagement element is completed by the engagement control, the engagement element starts to have a torque transmission capacity. Even if an accelerator operating member such as an accelerator pedal of a vehicle is operated before the engagement element starts to have torque transmission capacity, the throttle valve provided in the engine is closed until the engagement element starts to have torque transmission capacity. To be left. After the engaging element starts to have a torque transmission capacity, the opening of the throttle valve is raised to a certain opening. As a result, the torque output from the engine increases and the acceleration starts when the vehicle starts to move. The constant opening is set to an opening at which the torque input to the engagement element does not exceed the torque transmission capacity of the engagement element. Therefore, even if the opening degree of the throttle valve is increased to a constant opening degree, it is possible to suppress the blow-up of the rotation (turbine rotation) of the turbine runner of the torque converter.

  Therefore, it is possible to improve the start feeling by shortening the time lag from the start of the engine to the start of the vehicle, but at the time of synchronization when the turbine rotation speed matches the synchronous rotation speed by suppressing the blow-up of the turbine rotation Synchronous shock can be suppressed.

  The vehicle may be a vehicle that executes idling stop control that stops the engine when a predetermined engine stop condition is satisfied and restarts the engine when the brake is released.

  In this case, the start feeling at the time of return from the idling stop can be improved, and the synchronous shock that occurs at the time of synchronization in which the turbine rotational speed matches the synchronous rotational speed can be suppressed.

  According to the present invention, it is possible to improve the start feeling by shortening the time lag from the start of the engine to the start of the vehicle, but the turbine rotation speed matches the synchronous rotation speed by suppressing the blow-up of the turbine rotation. Synchronous shock that occurs during synchronization can be suppressed.

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 skeleton figure which shows the structure of the drive system of a vehicle. It is a figure which shows the state of each engagement element in P range, R range, N range, and D range. It is a flowchart which shows the content of engagement control. It is a figure which shows an example of the time change of the instruction | command hydraulic pressure of a clutch at the time of a return from an idling stop, an engine speed, a turbine speed, and the acceleration which arises in a vehicle. It is a figure which shows the example of a setting of a turbine determination value. It is a figure for demonstrating the result of complete explosion determination in the case of accelerator off, and turbine rotation determination. It is a figure for demonstrating the result of the complete explosion determination in the case of accelerator on, and a turbine rotation determination. It is a flowchart which shows the content of throttle control. It is a figure which shows an example of the time change of the turbine rotation speed at the time of a return from an idling stop, an accelerator opening degree, a throttle opening degree, and the acceleration which arises in a vehicle. It is a figure which shows the example of the time change of the turbine rotation speed in the prior art example of throttle control, an accelerator opening degree, a throttle opening degree, and the acceleration which arises in a vehicle. It is a figure which shows the example of the time change of the turbine rotation speed in the other conventional example of throttle control, an accelerator opening degree, a throttle opening degree, and the acceleration which arises in a vehicle.

  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 drive wheels (for example, left and right front wheels) of the vehicle 1 via a torque converter 3 and a stepped automatic transmission (AT) 4. The engine 2 includes an electronic throttle valve 71 for adjusting the amount of intake air into the combustion chamber of the engine 2, an injector (fuel injection device) 72 that injects fuel into the intake air, and an ignition plug 73 that generates electric discharge in the combustion chamber. Etc. are provided. Further, the engine 2 is provided with a starter (not shown) for starting the engine 2.

  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.

  The engine ECU 11 is connected to an accelerator sensor 21, an engine speed sensor 22, a throttle opening sensor 23, and the like.

  The accelerator sensor 21 outputs a detection signal corresponding to the operation amount of an accelerator pedal (not shown) operated by the driver. 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 outputs a pulse signal synchronized with the rotation of the engine 2 (rotation of the crankshaft) as a detection signal. 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 throttle opening sensor 23 outputs a detection signal corresponding to the opening (throttle opening) of the electronic throttle valve 71.

  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 information acquired from detection signals of various sensors and / or various information input from other ECUs. The throttle valve 71, injector 72, spark plug 73, and the like are controlled.

  A shift position sensor 24, a turbine speed sensor 25, and the like are connected to the ATECU 12.

  The shift position sensor 24 outputs a detection signal corresponding to the position of the shift lever (select lever). As positions of the shift lever, for example, a P position (parking position), an R position (reverse position), an N position (neutral position), and a D position (drive position) are provided. The P position, R position, N position and D position correspond to the P range, R range, N range and D range, respectively. The shift lever can be shifted between the P position, the R position, the N position, and the D position, and switching of the range can be instructed by the shift operation.

  The turbine speed sensor 25 outputs a pulse signal synchronized with the rotation of the turbine runner 32 (see FIG. 2) of the torque converter 3 as a detection signal. The ATECU 12 converts the frequency of the pulse signal input from the turbine rotation speed sensor 25 into a turbine rotation speed that is the rotation speed of the turbine runner 32.

  The AT ECU 12 changes the range or gear position of the automatic transmission 4 based on information acquired from detection signals of various sensors and / or various information input from other ECUs. A valve included in a hydraulic circuit 74 for supplying hydraulic pressure to the engine is controlled.

  The valves include a C2 solenoid valve 75 for controlling the hydraulic pressure supplied to the clutch C2 (see FIG. 2). As the C2 solenoid valve 75, a valve capable of controlling the output hydraulic pressure by a current value, for example, a linear solenoid valve is used.

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

  The brake sensor 26 outputs a detection signal corresponding to an operation amount of a brake pedal disposed in the vehicle interior.

  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 as a detection signal from the electromagnetic pickup. Since the frequency of the pulse signal corresponds to the vehicle speed, the brake ECU 13 converts the frequency of the pulse signal input from the vehicle speed sensor 27 into the vehicle speed.

  The brake ECU 13 controls the brake actuator 76 and the like based on information obtained from detection signals of various sensors (the amount of operation of the brake pedal, the vehicle speed of the vehicle 1) and / or various information input from other ECUs. The braking force applied to the wheels from each brake is controlled so that the vehicle 1 is braked in a state where the posture of the vehicle 1 is kept stable.

  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 (idling stop) 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, a restart request is output from the IDSECU 14 to the engine ECU 11. In response to this restart request, the engine ECU 11 restarts the engine 2 (returns from idling stop).

<Configuration of drive system>
FIG. 2 is a skeleton diagram showing the configuration of the drive system of the vehicle 1.

  The torque converter 3 includes a pump impeller 31, a turbine runner 32, and a lockup clutch 33. An output shaft (E / G output shaft) of the engine 2 is connected to the pump impeller 31, and the pump impeller 31 is provided so as to be integrally rotatable around the same rotation axis as the E / G output shaft. ing. The turbine runner 32 is provided to be rotatable about the same rotation axis as the pump impeller 31. The lockup clutch 33 is provided to directly connect / separate the pump impeller 31 and the turbine runner 32. When the lockup clutch 33 is engaged, the pump impeller 31 and the turbine runner 32 are directly connected, and when the lockup clutch 33 is released, the pump impeller 31 and the turbine runner 32 are separated.

  When the E / G output shaft is rotated in a state where the lockup clutch 33 is released, the pump impeller 31 rotates. When the pump impeller 31 rotates, an oil flow from the pump impeller 31 toward the turbine runner 32 is generated. This oil flow is received by the turbine runner 32 and the turbine runner 32 rotates. At this time, the amplifying action of the torque converter 3 occurs, and the turbine runner 32 generates a power larger than the power (torque) of the E / G output shaft.

  When the lockup clutch 33 is engaged, when the E / G output shaft is rotated, the E / G output shaft, the pump impeller 31 and the turbine runner 32 are rotated together.

  An oil pump 5 is provided between the torque converter 3 and the automatic transmission 4. The pump shaft of the oil pump 5 is provided so as to be rotatable integrally with the pump impeller 31. Thereby, when the pump impeller 31 is rotated by the power of the engine 2, the pump shaft of the oil pump 5 rotates and the oil pump 5 generates hydraulic pressure. The hydraulic pressure generated by the oil pump 5 is supplied to the hydraulic circuit 74.

  The automatic transmission 4 is a four-speed AT having a shift speed of 4 forward speeds and 1 reverse speed. The automatic transmission 4 includes an input shaft 41, an output shaft 42, a center shaft 43, and a Ravigneaux type planetary gear mechanism 44.

  The input shaft 41 is connected to the turbine runner 32 of the torque converter 3 and is provided so as to be integrally rotatable about the same rotation axis as the turbine runner 32.

  The output shaft 42 is provided in parallel with the input shaft 41.

  The center shaft 43 is separated from the input shaft 41 on the side opposite to the engine 2 side, and is provided on the same rotational axis as the input shaft 41.

  The planetary gear mechanism 44 includes a front sun gear 51, a rear sun gear 52, a carrier 53, a ring gear 54, a long pinion gear 55, and a short pinion gear 56. The front sun gear 51 is fitted on the center shaft 43 so as to be relatively rotatable. The rear sun gear 52 is provided on the side opposite to the engine 2 side with respect to the front sun gear 51 and is externally fitted to the center shaft 43 so as to be relatively rotatable. A center shaft 43 is connected to the carrier 53, and the carrier 53 is provided so as to be rotatable integrally with the center shaft 43. The carrier 53 rotatably supports the long pinion gear 55 and the short pinion gear 56. The ring gear 54 has an annular shape that surrounds the periphery of the carrier 53 outside the rear sun gear 52 in the rotational radial direction, and meshes with the long pinion gear 55. The long pinion gear 55 has an axial length longer than that of the short pinion gear 56, and meshes with the front sun gear 51. Short pinion gear 56 meshes with rear sun gear 52 and long pinion gear 55.

  The ring gear 54 holds the first output gear 61 so as to have a common rotation axis. The first output gear 61 is engaged with a second output gear 62 that is supported on the output shaft 42 so as not to rotate relative to the output shaft 42. A third output gear 63 is supported on the output shaft 42 so as not to rotate relative to the output shaft 42, and the third output gear 63 meshes with a ring gear 64 provided in the differential gear 6. Thereby, the rotation of the ring gear 54 is transmitted to the differential gear 6 via the first output gear 61, the second output gear 62, the output shaft 42 and the third output gear 63.

  The automatic transmission 4 includes three clutches C1 to C3, two brakes B1 and B2, and a one-way clutch F.

  The clutch C1 is switched between an engaged state (ON) for connecting the input shaft 41 and the front sun gear 51 and a released state (OFF) for releasing the connection.

  The clutch C2 is switched between an engaged state (ON) for connecting the input shaft 41 and the rear sun gear 52 and a released state (OFF) for releasing the connection.

  The clutch C3 is switched between an engaged state (on) for connecting the input shaft 41 and the center shaft 43 (carrier 53) and a released state (off) for releasing the connection.

  The brake B <b> 1 is switched between an engaged state (on) in which the front sun gear 51 is braked and a released state (off) in which the front sun gear 51 is allowed to rotate.

  The brake B <b> 2 is switched between an engaged state (on) for braking the carrier 53 and a released state (off) allowing the carrier 53 to rotate.

  The one-way clutch F allows only forward rotation of the carrier 53 (rotation in the same direction as the output shaft of the engine 2).

  FIG. 3 is a diagram illustrating states of the clutches C1 to C3, the brakes B1 and B2, and the one-way clutch F in the P range, the R range, the N range, and the D range.

  In FIG. 3, “◯” indicates that the clutches C1 to C3 and the brakes B1 and B2 are engaged. In addition, the one-way clutch F is in an engaged state that prevents the carrier 53 from rotating in the reverse direction.

  In the P range and the N range, the clutches C1 to C3 and the brakes B1 and B2 are released.

  In the R range, the clutch C1 and the brake B2 are engaged, and the clutches C2 and C3 and the brake B1 are released.

  At the first speed in the D range, the clutch C2 is engaged, and the clutches C1, C3 and the brakes B1, B2 are released.

  In the second speed in the D range, the clutch C2 and the brake B1 are engaged, and the clutches C1, C3 and the brake B2 are released.

  In the third speed of the D range, the clutches C2 and C3 are engaged, and the clutch C1 and the brakes B1 and B2 are released.

  At the fourth speed in the D range, the clutch C3 and the brake B1 are engaged, and the clutches C1, C2 and the brake B2 are released.

<Engagement control>
FIG. 4 is a flowchart showing the contents of the engagement control. FIG. 5 is a diagram illustrating an example of a change over time in the indicated hydraulic pressure of the clutch C2, the engine speed, the turbine speed, and the acceleration generated in the vehicle 1 when returning from the idling stop.

  When the engine restart condition is satisfied after the engine 2 is automatically stopped by the idling stop control, cranking of the engine 2 is started (time T1). When the shift lever is positioned at the D position, the ATECU 12 starts engagement control for engaging the clutch C2 constituting the first gear (time T1).

  In the engagement control, each process described below is executed by the ATECU 12.

  First, it is determined whether or not the complete explosion determination flag provided in the RAM of the ATECU 12 is on (step S1). The complete explosion determination flag is a flag indicating whether or not the engine 2 has completely exploded. At the start of the engagement control, the complete explosion determination flag is reset to 0, so that the state of the complete explosion determination flag is turned off. When the engine 2 is cranked and the spark plug of the engine 2 is sparked, the engine 2 is completely exploded, and when the engine speed rises to a predetermined engine determination value (for example, 400 rpm), the complete explosion determination flag is set. When 1 is set, the complete explosion determination flag is turned on.

  When the state of the complete explosion determination flag is off (NO in step S1), it is next determined whether or not the state of the turbine rotation determination flag provided in the RAM of the ATECU 12 is on (step S2). . The turbine rotation determination flag is a flag indicating whether or not the turbine rotation speed has increased to a predetermined turbine determination value. At the start of the engagement control, the turbine rotation determination flag is reset to 0, so that the state of the turbine rotation determination flag is turned off. When the engine speed increases, the turbine speed increases, and when the turbine speed reaches the turbine determination value, the turbine rotation determination flag is set to 1 by turning on the turbine rotation determination flag. .

  While each state of the complete explosion determination flag and the turbine rotation determination flag is off (NO in step S2), as a filling control for speeding up the filling of the oil into the clutch C2, the target value of the hydraulic pressure supplied to the clutch C2 is used. A specified hydraulic pressure is maintained at the filling pressure (step S3, time T1-T2). The command hydraulic pressure of the clutch C2 corresponds to the current value input to the C2 solenoid valve 75 (see FIG. 1) for controlling the hydraulic pressure supplied to the clutch C2. By controlling the current value supplied to the C2 solenoid valve 75 to a current value corresponding to the filling pressure, oil is supplied to the clutch C2.

  When the engine speed increases to the engine determination value (YES in step S1), the state of the complete explosion determination flag is turned on (time T2). Then, it is determined whether or not the state of the clutch contact flag provided in the RAM of the ATECU 12 is on (step S4). The clutch contact flag is a flag that indicates whether or not a piston for generating a frictional force by pressing the clutch plate of the clutch C2 and the clutch disk is in contact with the clutch plate. At the start of the engagement control, the clutch contact flag is reset to 0, so that the state of the clutch contact flag is turned off.

  While the state of the complete explosion determination flag is on and the state of the clutch contact flag is off (NO in step S4), the command hydraulic pressure is held at the first initial pressure lower than the charging pressure (step S5, time) T2-T3). The first initial pressure is set to a value at which the shock generated by the piston of the clutch C2 coming into contact with the clutch plate does not exceed the allowable level.

  When the oil filling into the clutch C2 is completed and the piston comes into contact with the clutch plate, the clutch C2 starts to engage while slipping, so that the clutch C2 starts to have a torque transmission capacity. As the torque transmission capacity of the clutch C2 increases, the turbine speed decreases from the peak. When it is detected that the turbine rotational speed has decreased by a first predetermined amount (for example, 30 rpm), 1 is set in the clutch contact flag to turn on the state of the clutch contact flag (time T3). .

  When the state of the clutch contact flag is turned on (YES in step S4), it is determined whether or not the state of the rotation descent flag provided in the RAM of the ATECU 12 is on (step S6). The rotation drop flag is a flag indicating whether or not the turbine rotation speed has dropped by a second predetermined amount (for example, 50 rpm) larger than the first predetermined amount. At the start of the engagement control, the rotation descent flag is reset to 0, so that the state of the rotation descent flag is turned off.

  While the state of the clutch contact flag is on and the state of the rotation drop flag is off (NO in step S6), the command hydraulic pressure is held at the second initial pressure lower than the first initial pressure (step S7, Time T3-T4).

  When it is detected that the turbine rotational speed has dropped by a second predetermined amount, 1 is set in the rotation drop flag, so that the state of the rotation drop flag is turned on (time T4).

  Thereafter, the command hydraulic pressure is gradually increased from the second initial pressure by a sweep with a constant time change rate (time gradient) (step S8, time T4-T5). As a result, the engagement of the clutch C2 proceeds and the turbine rotational speed decreases.

  After the start of the sweep, it is determined whether or not the state of the synchronization detection flag provided in the RAM of the ATECU 12 is on (step S9). The synchronization detection flag is a flag indicating whether or not it is detected that the turbine rotation speed matches the first-speed synchronization rotation speed, that is, whether or not synchronization of the turbine rotation speed is detected. At the start of the engagement control, the synchronization detection flag is reset to 0, so that the state of the synchronization detection flag is turned off. The first-speed synchronous rotational speed is the rotational speed of the input shaft 41 (see FIG. 2) that is synchronized with the rotational speed of the output shaft 42 (see FIG. 2) when the shift stage of the automatic transmission 4 constitutes the first speed stage. It is.

  When the engagement of the clutch C2 progresses and the slip of the clutch C2 disappears, the turbine rotation speed stops dropping, and the turbine rotation speed matches the first-speed synchronous rotation speed. When it is detected that the turbine rotational speed matches the 1st-speed synchronous rotational speed, 1 is set in the synchronous detection flag, so that the state of the synchronous detection flag is turned on (time T5). Then, the command oil pressure is increased to the maximum pressure, and the engagement control is terminated.

<Filling control time>
FIG. 6 is a diagram illustrating a setting example of the turbine determination value.

  The turbine determination value is variably set according to the accelerator opening.

  For example, the turbine determination value is set to a larger value stepwise as the accelerator opening is larger. In a specific example, when the accelerator opening is 0%, the turbine determination value is set to 30 rpm. When the accelerator opening is within the range of 0 to 50% (not including the lower limit value and including the upper limit value), the turbine determination value is set to 50 rpm, and the accelerator opening is within the range of 50 to 100% (lower limit). If it is not including a value but including an upper limit value), the turbine determination value is set to 100 rpm.

  FIG. 7A is a diagram for explaining the results of complete explosion determination and turbine rotation determination when the accelerator is off, and FIG. 7B is for explaining the results of complete explosion determination and turbine rotation determination when the accelerator is on. FIG.

  As indicated by the solid line in FIGS. 7A and 7B, when the increase in the engine speed after the complete explosion of the engine 2 is fast, the engine engine speed is set to the engine before the time T21 when the turbine engine speed reaches the turbine determination value. The determination value is reached (time T2). Accordingly, in response to the increase in the engine speed up to the engine determination value, the command hydraulic pressure is lowered from the filling pressure to the first initial pressure.

  On the other hand, when the increase in the rotational speed after the complete explosion of the engine 2 is slow, as indicated by the two-dot chain line in FIGS. 7A and 7B, before the time T22 when the engine rotational speed reaches the engine determination value, The turbine rotation speed reaches the turbine determination value (time T21). Then, in response to the turbine rotation speed increasing to the turbine determination value, 1 is set in the turbine rotation determination flag, the turbine rotation determination flag is turned on, and the indicated hydraulic pressure is changed from the charging pressure to the first value. 1 Reduced to initial pressure.

  Therefore, regardless of the degree of increase in the number of revolutions after the complete explosion of the engine 2, it is possible to prevent the instruction oil pressure from being held at the filling pressure (filling control time) from being unnecessarily prolonged.

  Further, when the accelerator pedal is depressed (when the accelerator is on), the turbine determination value is set to a larger value than when the accelerator pedal is not depressed (when the accelerator is off). As a result, as understood from a comparison between FIG. 7A and FIG. 7B, it takes a longer time for the turbine speed to increase to the turbine determination value when the accelerator is on than when the accelerator is off. Therefore, when the accelerator is on, the time during which the command pressure is maintained at the filling pressure is longer than when the accelerator is off.

<Throttle control>
FIG. 8 is a flowchart showing the contents of throttle control. FIG. 9 is a diagram illustrating an example of a time change in the turbine rotation speed, the accelerator opening, the throttle opening, and the acceleration generated in the vehicle 1 when returning from the idling stop.

  At the time of return from the idling stop, a command is output from the AT ECU 12 to the engine ECU 11, and the throttle control shown in FIG. 8 is executed by the engine ECU 11 in response to this command.

  In the throttle control, it is determined whether or not the accelerator is on (step S11). When the accelerator opening is less than a predetermined value (for example, less than 1.0% or may be 0%), it is determined that the accelerator pedal is not depressed and the accelerator is open. When the degree is equal to or greater than the predetermined value, it is determined that the accelerator pedal is depressed and the accelerator is on.

  When the accelerator is off (NO in step S11), the throttle opening which is the opening of the electronic throttle valve 71 (see FIG. 1) is not limited, and the throttle control is terminated.

  If the accelerator is on (YES in step S11), it is determined whether or not the state of the rotation descent flag is on (step S12).

  When the state of the rotation descent flag is OFF (NO in step S12), the throttle opening is limited to 0% that is the first opening (step S13). That is, oil is supplied to the clutch C2 by the engagement control executed at the time of return from the idling stop control, and after the turbine rotation speed is increased, the piston of the clutch C2 comes into contact with the clutch plate and the torque of the clutch C2 is increased. As the transmission capacity increases, the turbine speed decreases from the peak. The throttle opening is limited to 0% even when the accelerator is on until the turbine speed decreases by the second predetermined amount.

  When the turbine rotational speed falls by a second predetermined amount from the peak and the state of the rotation drop flag changes from off to on (YES in step S12, time T11), it is determined whether or not the state of the synchronization detection flag is on. (Step S14).

  When the state of the synchronization detection flag is OFF (NO in step S14), the throttle opening is limited to the second opening (step S15). That is, the throttle opening is limited to the second opening until the turbine rotation speed coincides with the first-speed synchronous rotation speed after the turbine rotation speed falls by the second predetermined amount (time T11-T12). The second opening is set to a constant opening at which the torque input to the clutch C2 does not exceed the torque transmission capacity of the clutch C2.

  When the turbine rotational speed matches the 1st-speed synchronous rotational speed and the state of the synchronous detection flag changes from OFF to ON (YES in step S14, time T12), the throttle opening changes for a certain time by sweeping from the second opening. It is gradually increased at a rate (time gradient) (step S16).

  When the throttle opening increases to a value corresponding to the accelerator opening (YES in step S17, time T13), the throttle control is terminated.

<Effect>
As described above, in the engagement control in which the clutch C2 of the automatic transmission 4 is engaged, the command oil pressure is raised to the filling pressure, and the command oil pressure is held at the filling pressure for a predetermined time. Thereafter, the command oil pressure is maintained at the first initial pressure until the command oil pressure is lowered from the filling pressure to the first initial pressure until the clutch C2 starts to have a torque transmission capacity. When the clutch C2 starts to have a torque transmission capacity, the indicated hydraulic pressure is lowered from the first initial pressure to the second initial pressure, and the turbine rotational speed, which is the rotational speed input to the automatic transmission 4, is a second predetermined amount from the peak. The command hydraulic pressure is maintained at the second initial pressure until the pressure falls. When the turbine speed decreases by a second predetermined amount, the command oil pressure is increased by sweeping from the second initial pressure to the maximum pressure.

  In the conventional engagement control, after the command oil pressure is held at the filling pressure, the command oil pressure is held at a constant initial pressure. On the other hand, in the engagement control by the ATECU 12, after the command oil pressure is held at the filling pressure, the command oil pressure is lowered to the second initial pressure in two stages through a period in which the command oil pressure is held at the first initial pressure. Until the clutch C2 starts to have a torque transmission capacity, in other words, until the piston of the clutch C2 comes into contact with the clutch plate, the command hydraulic pressure is maintained at the first initial pressure that is relatively high. A time lag until the clutch C2 starts to have a torque transmission capacity can be shortened. Then, after the clutch C2 starts to have a torque transmission capacity, the turbine rotational speed starts to decrease, the turbine rotational speed decreases sufficiently, and the indicated hydraulic pressure becomes relatively high until the amount of decrease reaches the second predetermined amount. The second initial pressure is reduced to a low level and maintained. Thereby, the synchronous shock which arises at the time of the synchronization in which a turbine rotational speed corresponds to 1st speed synchronous rotational speed can be suppressed.

  Therefore, at the time of return from the idling stop, the time lag from the start of cranking of the engine 2 to the start of the vehicle 1 can be shortened, and the synchronous shock generated at the time of synchronization in which the turbine rotational speed matches the first speed synchronous rotational speed is suppressed. Can do.

  In the engagement control, when the engine speed increases to the engine determination value or the turbine rotation speed increases to the turbine determination value, the command oil pressure is reduced from the charging pressure to the first initial pressure. As a result, when the increase in the engine speed at the start of the engine 2 is rapid, the engine speed increases to the engine determination value before the turbine rotation speed increases to the turbine determination value, and the indicated hydraulic pressure is reduced from the charging pressure. Reduced to the first initial pressure. On the other hand, when the increase in the engine speed at the start of the engine 2 is slow, before the engine speed increases to the engine determination value, the turbine rotation speed increases to the turbine determination value, and the indicated hydraulic pressure is increased from the charging pressure. 1 Reduced to initial pressure. Therefore, it is possible to suppress unnecessarily prolonging the time during which the indicated hydraulic pressure is maintained at the charging pressure regardless of the degree of increase in the engine speed at the time of starting the engine. As a result, it is possible to suppress excessive hydraulic pressure of the clutch C2, and it is possible to suppress a contact shock that occurs when the piston of the clutch C2 contacts the clutch plate.

  The turbine determination value is set to a larger value stepwise as the accelerator opening is larger. Therefore, the larger the accelerator opening, the longer the time during which the command hydraulic pressure is held at the charging pressure, and the time lag from the start of engagement control until the clutch C2 begins to have torque transmission capacity can be shortened. . As a result, when returning from the idling stop, the time lag from the start of cranking of the engine 2 to the start of the vehicle 1 can be further shortened, and the start feeling of the vehicle 1 according to the driver's intention can be realized.

  Even if the accelerator pedal of the vehicle 1 is operated before the clutch C2 starts to have the torque transmission capacity, the opening of the electronic throttle valve 71 remains at the first opening until the clutch C2 starts to have the torque transmission capacity. It is set to a certain 0%, and the electronic throttle valve 71 is kept closed. After the clutch C2 starts to have a torque transmission capacity, the opening degree of the electronic throttle valve 71 is raised to the second opening degree. As a result, the torque output from the engine 2 increases, and the acceleration starts when the vehicle 1 starts moving. The second opening is set to a constant opening at which the torque input to the clutch C2 does not exceed the torque transmission capacity of the clutch C2. Therefore, even if the opening degree of the electronic throttle valve 71 is raised to the second opening degree, the blow-up of the turbine rotation can be suppressed.

  Therefore, while the start feeling can be improved by shortening the time lag from the start of the engine 2 until the vehicle 1 starts to move, the turbine speed matches the 1st speed synchronous speed by suppressing the blow-up of the turbine speed. It is possible to further suppress the synchronization shock that occurs during synchronization.

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

  Each of the first initial pressure and the second initial pressure may be a fixed value or a variable value.

  For example, the first initial pressure may be variably set according to the accelerator opening. Specifically, the first initial pressure may be set to a larger value stepwise or continuously as the accelerator opening is larger. As a result, the larger the accelerator opening, the shorter the time lag from the start of engagement control until the clutch C2 begins to have torque transmission capacity, so the vehicle 1 according to the intention of the driver who operated the accelerator pedal. The starting feeling can be realized.

  For example, the second initial pressure may be variably set according to the accelerator opening. Specifically, the second initial pressure may be set to a larger value stepwise or continuously as the accelerator opening is larger. As a result, the larger the accelerator opening, the shorter the time lag from when the clutch C2 starts to have torque transmission capacity to the synchronization of the turbine speed, so the vehicle 1 according to the intention of the driver who operated the accelerator pedal. The starting feeling can be realized. The second initial pressure is a constant value, but may be gradually increased (swept) as time elapses.

  Each of the above-mentioned controls is not limited to returning from the idling stop (when the engine 2 is restarted by the idling stop control), but immediately after the engine 2 is started, the shift lever is shifted from the P position or the N position to the D position. May be executed in some cases.

  Each of the above-described sensors is merely an example of a sensor related to the present invention, and other sensors may be connected to the engine ECU 11, the AT ECU 12, the brake ECU 13, and the IDSECU 14.

  Further, some or all of the functions of the engine ECU 11, the AT ECU 12, the brake ECU 13, and the IDSECU 14 may be integrated into one ECU.

  Further, although the configuration in which the vehicle 1 is mounted with the stepped automatic transmission 4 is taken up, the present invention is a continuously variable transmission or a power split type continuously variable transmission provided with a clutch that is engaged when the vehicle starts. It can also be applied to a vehicle equipped with a machine. The power split type continuously variable transmission includes a belt-type continuously variable transmission mechanism that continuously changes power by changing a transmission ratio, and a constant transmission mechanism that changes power at a constant transmission ratio. Is a transmission that can be divided into two systems for transmission.

  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 3 Torque converter 4 Automatic transmission 11 Engine ECU (vehicle control device, throttle control means)
12 ATECU (vehicle control device, engagement control means)
71 Electronic throttle valve 74 Hydraulic circuit C2 Clutch (engagement element)

Claims (1)

An engine, a torque converter, and an automatic transmission that includes a hydraulic circuit and an engagement element that is engaged by hydraulic pressure supplied from the hydraulic circuit, and that receives power from the engine via the torque converter, are mounted. A control device used in a vehicle,
Engagement control means for controlling the hydraulic circuit of the automatic transmission and executing engagement control for engaging the engagement element of the automatic transmission when the engine is started;
The throttle valve provided in the engine is closed until the engagement element starts to have torque transmission capacity by the engagement control, and after the engagement element starts to have torque transmission capacity, the opening of the throttle valve And a throttle control means for increasing the torque input to the engagement element to a certain degree of opening that does not exceed the torque transmission capacity of the engagement element.

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