JP5338982B2 - Control device for automatic transmission for vehicle - Google Patents

Abstract

Neutral control is carried out during vehicle driving while decline in drivability is suppressed. During deceleration driving when the accelerator is not pushed, a C1 clutch pressure is gradually reduced in a state where an automatic transmission (12) is left in a current gear stage (GSN) (phase 2 control), and if a starting gear ratio input rotational speed (NINS) during deceleration driving becomes equal to or less than a predetermined rotational speed (NEIDL+ß), the C1 clutch pressure is reduced such that a clutch (C1) is completely released in a state where the automatic transmission (12) is placed in a first gear stage (phase 4 control). For example, if a certain speed (V) is reached, output torque (TOUT) is gradually reduced according to the gradual reduction of the C1 clutch pressure so as to suppress the uncomfortable sensation caused by variation in deceleration speed. In addition, for example if the certain speed (V) is reached, the clutch (C1) is in a slipping state, and when the accelerator is pushed and N control during driving is thereby cancelled, a sensation of slowness upon re-acceleration can be suppressed while engagement shock is also suppressed.

Description

  The present invention relates to a control device for an automatic transmission for a vehicle that executes neutral control, and more particularly to control when executing neutral control while the vehicle is running.

  For example, when a predetermined start condition (for example, a start condition that the shift position is the forward travel “D” position, the accelerator is off, the brake is on, and the vehicle is stopped) is satisfied during idling of the engine, “D In the position, the transmission torque capacity (equivalent to engagement torque, engagement force, clutch pressure, etc.) of the vehicle start engagement device (for example, input clutch, start clutch) that is engaged when the vehicle starts is reduced. Vehicles that perform neutral control (N control) to reduce engine idling load and improve fuel efficiency by making the power transmission path from the engine to the drive wheels close to neutral (power transmission suppressed state) are well known. It has been. For example, this is the vehicle disclosed in Patent Documents 1 and 2. In such N control, for example, it is proposed that the start clutch is in a half-released state (slip state) in consideration of responsiveness of clutch engagement at the time of restart. In N control, it has also been proposed to completely release the starting clutch in order to further improve fuel efficiency. Specifically, Patent Document 1 describes that N control for completely releasing the starting clutch is executed in accordance with traffic conditions around the vehicle such as a lighting state of a traffic light received from the outside.

JP 2008-286281 A JP-A-5-79562

  By the way, the N control is started not only when the vehicle is stopped but also when the vehicle is running, aiming at further improvement of fuel consumption, that is, N during the vehicle running from the accelerator-off decelerated running to the vehicle stopping. It is conceivable to execute control (N control during traveling). However, when executing the N control during traveling, there is a possibility that an uncomfortable feeling or the like may occur due to a change in deceleration due to, for example, a decrease in engine braking force during deceleration traveling. In consideration of acceleration response at the time of reacceleration due to accelerator re-depression, it is desired to return (cancel) from N control as soon as possible while suppressing the shock associated with engagement of the starting clutch. However, unlike the case of starting the vehicle after the vehicle is stopped, the re-acceleration is performed while the vehicle speed is changing while the vehicle is decelerating. Therefore, the same control as that when starting the vehicle may not work. For example, since the vehicle is running, there is a possibility that the feeling of rising of the drive torque due to a delay in response of clutch engagement at the time of reacceleration is greater than when the vehicle starts. Further, if the clutch engagement is accelerated in order to suppress the feeling of stickiness, the engagement shock may increase. As described above, when N control is started while the vehicle is running, fuel efficiency can be improved. there is a possibility. Note that such a problem is not known, and it has not been proposed yet to start N control while the vehicle is running while suppressing a decrease in drivability as much as possible.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is an automatic transmission for a vehicle that can execute neutral control while the vehicle is running while suppressing a decrease in drivability. It is to provide a control device.

  In order to achieve the above object, the gist of the present invention is that (a) the power from the engine to the drive wheel is reduced by reducing the transmission torque capacity of the starting clutch that transmits the engine power to the drive wheel side. A control device for an automatic transmission for a vehicle capable of executing a neutral control in which a transmission path is in a power transmission restrained state, wherein (b) the automatic transmission is set to a current gear ratio during acceleration-decelerated traveling The transmission torque capacity is gradually reduced, and when the vehicle speed-related value during the decelerating traveling is equal to or less than a predetermined vehicle speed-related value, the starting clutch is released with the automatic transmission set to the gear ratio at the time of starting. Thus, the transmission torque capacity is reduced.

  In this way, during the acceleration-decelerated deceleration travel, the transmission torque capacity is gradually reduced with the automatic transmission at the current gear ratio, and the vehicle speed-related value during the deceleration travel is a predetermined vehicle speed-related value. In the case of the following, the transmission torque capacity is reduced so that the starting clutch is released with the automatic transmission set to the gear ratio at the time of starting. With the gradual decrease, the output torque (for example, engine brake torque) is gradually decreased, and the uncomfortable feeling due to the change in deceleration is suppressed. In addition, for example, when the vehicle speed is high to some extent, the starting clutch is in a slip state, and when releasing the N control during traveling by accelerator-on, it is possible to suppress the feeling of rattling during re-acceleration while suppressing the engagement shock. . Further, for example, since the output torque goes to substantially zero due to a decrease in the transmission torque capacity, even when the starting clutch is completely released during vehicle deceleration traveling, the uncomfortable feeling due to the change in deceleration is suppressed. Further, for example, when the vehicle speed is less than a predetermined vehicle speed-related value, the automatic transmission is set to the gear ratio at the time of starting and the starting clutch is released. By doing so, it is possible to suppress the feeling of slack during re-acceleration while suppressing the engagement shock. Therefore, it is possible to further improve fuel efficiency by executing neutral control while the vehicle is traveling while suppressing a decrease in drivability.

  Here, preferably, the rotational speed on the input side of the automatic transmission calculated based on the vehicle speed related value during the decelerating traveling and the gear ratio at the start of the automatic transmission is the idle rotational speed of the engine. The transmission torque capacity is reduced so as to release the starting clutch when the rotational speed is lower than a predetermined rotational speed higher than the idle rotational speed. In this way, for example, when the output torque switches from negative torque to positive torque during decelerating travel (for example, from the state where the drive wheel side rotates the input side of the automatic transmission, the input side of the automatic transmission changes the drive wheel side). Since the starting clutch is disengaged (at the time of switching to the turning state), the negative torque, which is reduced toward substantially zero due to the decrease in the transmission torque capacity, is suppressed from switching to the positive torque, and the uncomfortable feeling due to the change in output torque is suppressed. The

  Preferably, during the deceleration traveling, the transmission clutch capacity is engaged with the starting clutch prior to gradually decreasing the transmission torque capacity with the automatic transmission at the current gear ratio. The maximum transmission torque capacity is reduced to a predetermined transmission torque capacity that does not cause differential rotation in the starting clutch even when the accelerator is turned on, and the vehicle speed related value during the deceleration traveling is higher than the predetermined vehicle speed related value. The transmission torque capacity is maintained at the predetermined transmission torque capacity until the vehicle speed is less than or equal to the predetermined vehicle speed related value. In this way, for example, it is possible to promptly shift to gradually reducing the transmission torque capacity in a state where the automatic transmission is set to the current gear ratio. Further, for example, the transmission torque capacity is maintained at the predetermined transmission torque capacity until the vehicle speed related value becomes equal to or less than the second predetermined vehicle speed related value, that is, the starting clutch is kept in a regulated state at the predetermined transmission torque capacity. When the N control is canceled during traveling by accelerator-on, the transmission torque capacity can be quickly increased to the maximum transmission torque capacity without the start clutch being in a slipping state, and the feeling of rattling during re-acceleration can be suppressed. .

  Preferably, in the automatic transmission, a gear stage at the time of starting corresponding to a gear ratio at the time of starting is established by engagement of the starting clutch and the one-way clutch, and the power of the engine is transmitted by fluid transmission. When the transmission torque capacity is gradually reduced in a state where the automatic transmission is at the current gear ratio, the fluid transmission device during the decelerating traveling is transmitted to the automatic transmission through a device. When the output rotational speed of the engine becomes equal to or lower than a second predetermined rotational speed near the idle rotational speed that is higher than the idle rotational speed of the engine, the transmission torque capacity is reduced so as to release the starting clutch. Prior to this, the transmission torque capacity is maintained at a second predetermined transmission torque capacity as low as possible so that the transmission torque capacity can be quickly increased when the accelerator is on, There kinematic transmission from the current gear position to shift to any gear during the starting. In this way, for example, the output torque is switched from negative torque to positive torque due to a decrease in the vehicle speed, and it is possible to feel a shock in the gear of the driving system or to cause a sense of incongruity due to switching in the direction in which the driving force is output. In contrast to this, the transmission torque in the starting clutch is reduced to suppress such uncomfortable feeling. Further, for example, even when some transmission torque is generated in the starting clutch, the one-way clutch is idling in the gear stage at the time of starting, so that no driving force is generated and the above-mentioned uncomfortable feeling is avoided. Further, for example, the automatic transmission is set to the gear ratio at the time of starting and the transmission torque capacity is held at the second predetermined transmission torque capacity. The feeling of slacking during acceleration can be suppressed. Further, when the N control is canceled during traveling, the one-way clutch is in the idling state, so that the engagement shock does not occur even if the start clutch is suddenly engaged, and the start clutch has the second predetermined transmission torque capacity. In other words, the transmission torque capacity can be quickly increased because the motor is kept waiting in a regulated state.

  Preferably, the second predetermined transmission torque capacity is a transmission torque capacity as low as possible capable of transmitting the idle torque of the engine. In this way, for example, the shock of the gear of the drive train due to the output torque being switched from negative torque to positive torque, the sense of incongruity due to switching in the direction in which the drive force is output, etc. are appropriately suppressed. When canceling the N control during traveling by accelerator-on, the transmission torque capacity can be quickly increased.

1 is a skeleton diagram illustrating a configuration of an automatic transmission provided in a vehicle to which the present invention is applied. FIG. 2 is an operation chart for explaining a combination of operations of friction engagement devices when a plurality of gear stages of the automatic transmission of FIG. 1 are established. It is a block diagram explaining the principal part of the electrical control system provided in the vehicle in order to control the automatic transmission etc. of FIG. FIG. 4 is a circuit diagram relating to a linear solenoid valve that controls the operation of each hydraulic actuator for clutches and brakes in the hydraulic control circuit of FIG. 3. It is a functional block diagram explaining the principal part of the control function of the electronic control apparatus of FIG. It is a figure which shows an example of the relationship (engine torque map) calculated | required experimentally beforehand and memorize | stored by using the throttle valve opening as a parameter. It is a figure which shows an example of the shift map used for determination of the gear stage of the automatic transmission of FIG. FIG. 4 is a flowchart for explaining a control operation for executing a running N control while suppressing a main part of the control operation of the electronic control device of FIG. 3, that is, a decrease in drivability. FIG. It is a time chart corresponding to the control action of FIG. FIG. 9 is a time chart when the traveling N control is canceled during the control operation of FIG. 8, and is a diagram illustrating an example when returning from phase 1 control; FIG. 9 is a time chart when the traveling N control is canceled during the control operation of FIG. 8, and is a diagram illustrating an example of returning from phase 2 control. FIG. 9 is a time chart when the traveling N control is canceled during the control operation of FIG. 8, and is a diagram illustrating an example when returning from phase 3 control; FIG. 9 is a time chart when the traveling N control is canceled during the control operation of FIG. 8, and is a diagram illustrating an example when returning from phase 4 control;

  Preferably, in the automatic transmission, for example, a plurality of gear stages (shift stages) are alternatively achieved by selectively connecting rotating elements of a plurality of sets of planetary gear units by an engagement device. Various planetary gear type automatic transmissions having four forward speeds, five forward speeds, six forward speeds, and more, and a pair of variable whose transmission diameters function as power transmission members are variable. A so-called belt-type continuously variable transmission that is wound around a pulley and continuously changes its transmission ratio steplessly, a pair of cones that rotate around a common axis, and a plurality of rotation centers that can rotate around the axis A so-called traction-type continuously variable transmission or engine shaft in which a plurality of rollers are clamped between the pair of cones and the transmission angle is made variable by changing the intersection angle between the rotation center of the rollers and the shaft center. And output shaft Constituted by an automatic transmission capable of transmitting power to the electric motor is mounted on a hybrid vehicle of a so-called parallel type provided in etc.. Further, the mounting posture of the automatic transmission with respect to the vehicle may be a horizontal installation type such as an FF (front engine / front drive) vehicle in which the axis of the automatic transmission is in the width direction of the vehicle. It may be a vertical installation type such as an FR (front engine / rear drive) vehicle in the longitudinal direction.

  Preferably, for example, in the neutral control of a vehicle equipped with a planetary gear type automatic transmission, the engagement devices are all set in a slipping state or a releasing state in a known “R” or “D” position, or in an automatic transmission. This is executed by forming a neutral state of the automatic transmission in which the power transmission path in the automatic transmission is interrupted, for example, by setting any one of the engagement devices for forming the gear stage to the slip state or the release state. The Further, for example, neutral control of a vehicle equipped with a belt type continuously variable transmission or a traction type continuously variable transmission includes well-known engagement devices and gear devices provided in a power transmission path from the engine to driving wheels. This is executed by forming the neutral state of the power transmission path by setting the engaging device in the forward / reverse switching device to the slip state or the release state. Further, for example, the engagement device provided in the power transmission path is set to the slip state or the release state separately from the engagement device included in the planetary gear type automatic transmission and the engagement device included in the forward / reverse switching device. Neutral control is also performed by forming a state.

  Preferably, as the engagement device, a friction engagement device such as a multi-plate or single-plate clutch or brake that is engaged by a hydraulic actuator is widely used. The oil pump for supplying the hydraulic oil for engaging the hydraulic friction engagement device may be driven by a driving power source for traveling to discharge the hydraulic oil, but is disposed separately from the driving power source, for example. It may be driven by a dedicated electric motor provided. The hydraulic control circuit including this hydraulic friction engagement device responds by supplying the output hydraulic pressure of a linear solenoid valve as an electromagnetic valve device directly to the hydraulic actuator (hydraulic cylinder) of the hydraulic friction engagement device, for example. Although it is desirable from the standpoint of performance, the shift control valve (shift control valve) is controlled by using the output hydraulic pressure of the linear solenoid valve as the pilot hydraulic pressure, and the hydraulic oil is supplied from the control valve to the hydraulic actuator. You can also. The linear solenoid valve is provided, for example, corresponding to each of a plurality of hydraulic friction engagement devices, but a plurality of hydraulic solenoid valves that are not simultaneously engaged, engaged, or controlled to be released. When a friction engagement device exists, various modes are possible, such as providing a common linear solenoid valve for them. In addition, it is not always necessary to perform the hydraulic control of all the hydraulic friction engagement devices with the linear solenoid valve. Some or all of the hydraulic control may be pressure control means other than the linear solenoid valve, such as duty control of the ON-OFF solenoid valve. You can go there. Further, the clutch or brake may be an electromagnetic engagement device such as an electromagnetic clutch or a magnetic powder clutch in addition to the hydraulic friction engagement device.

  Preferably, an internal combustion engine such as a gasoline engine or a diesel engine is widely used as the engine. Further, an electric motor or the like may be used in addition to this engine as a driving power source for auxiliary traveling.

  In this specification, “supplying hydraulic pressure” means “applying hydraulic pressure” or “supplying hydraulic oil controlled to the hydraulic pressure”.

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

  FIG. 1 is a skeleton diagram illustrating a configuration of a vehicular automatic transmission 12 (hereinafter, automatic transmission 12) provided in a vehicle 10 to which the present invention is applied. FIG. 2 is an operation table for explaining an operation state of the friction engagement device when a plurality of gear stages GS (shift stages GS) of the automatic transmission 12 is established. This automatic transmission 12 is suitably used for an FF vehicle mounted in the left-right direction (horizontal) of the vehicle 10, and is a transaxle case 14 (hereinafter, case 14) as a non-rotating member attached to the vehicle body. Inside, a first transmission unit 18 mainly composed of a single pinion type first planetary gear device 16, a double pinion type second planetary gear device 20, and a single pinion type third planetary gear device 22 are mainly used. As a Ravigneaux-type second transmission unit 24 on a common axis C, and the input shaft 26 is rotated and output from the output gear 28. The input shaft 26 corresponds to an input rotating member of the automatic transmission 12. In this embodiment, the input shaft 26 is a turbine shaft of a torque converter 32 as a fluid transmission device that is rotationally driven by an engine 30 that is a driving force source for traveling. It is configured integrally with. The output gear 28 corresponds to the output rotating member of the automatic transmission 12, and in this embodiment, for example, meshes with the diff ring gear 35 to transmit power to the differential gear device 34 shown in FIG. The counter drive gears constituting the counter gear pair are engaged with the counter driven gear arranged coaxially with the differential drive pinion constituting the final gear pair. In the automatic transmission 12 and the like configured as described above, the output of the engine 30 is output from the vehicle power transmission device 11 including the torque converter 32, the automatic transmission 12, the differential gear device 34, the pair of axles 36, and the like. Are sequentially transmitted to the left and right drive wheels 38 (see FIG. 3). The automatic transmission 12 and the torque converter 32 are substantially symmetrical with respect to the center line (axial center) C, and the lower half of the axial center C is omitted in the skeleton diagram of FIG.

  The torque converter 32 includes a pump impeller 32p connected to the crankshaft 31 of the engine 30, a turbine impeller 32t connected to the automatic transmission 12 via a turbine shaft (corresponding to the input shaft 26) of the torque converter 32, and The stator impeller 32s is prevented from rotating in one direction by a one-way clutch, and power is transmitted between the pump impeller 32p and the turbine impeller 32t via a fluid. That is, in the torque converter 32 of the present embodiment, the pump impeller 32p corresponds to the input rotating member, and the turbine impeller 32t corresponds to the output rotating member, and the power of the engine 30 is transferred to the automatic transmission 12 side via the fluid. Communicated. Further, a lockup clutch 33 is provided between the pump impeller 32p and the turbine impeller 32t, that is, between the input and output rotating members of the torque converter 32. Further, the pump impeller 32p is supplied with an operating hydraulic pressure as a source pressure for controlling the shift of the automatic transmission 12, controlling the operation of the lockup clutch 33, or supplying lubricating oil to each part. A mechanical oil pump 40 generated by being driven to rotate by 30 is connected.

  The automatic transmission 12 corresponds to the combination of any of the connected states of the rotating elements (sun gears S1 to S3, carriers CA1 to CA3, ring gears R1 to R3) of the first transmission unit 18 and the second transmission unit 24. Six forward gear stages (forward shift stages) from the first speed gear stage “1st” to the sixth speed gear stage “6th” are established, and one reverse gear stage (reverse gear stage) of the reverse gear stage “R” is established. ) Is established. As shown in FIG. 2, for example, in the forward gear stage, the first speed gear stage is engaged by the engagement of the clutch C1 and the brake B2, and the second speed gear stage is engaged by the engagement of the clutch C1 and the brake B1, and the clutch C1 is engaged. The third gear is set by engagement with the brake B3, the fourth gear is set by engagement of the clutch C1 and the clutch C2, and the fifth gear is set by engagement of the clutch C2 and the brake B3. The sixth gear is established by engaging the brake B1. Further, the reverse gear stage is established by the engagement of the brake B2 and the brake B3, and the clutch C1, C2 and the brakes B1 to B3 are all released to be in the neutral state.

The operation table of FIG. 2 summarizes the relationship between the gear stages GS and the operation states of the clutches C1 and C2 and the brakes B1 to B3, where “◯” indicates engagement and “◎” indicates engine braking. Only represents engagement. Since the one-way clutch F1 is provided in parallel to the brake B2 that establishes the first gear stage “1st”, it is not always necessary to engage the brake B2 when starting (acceleration). That is, it is sufficient to engage only the clutch C1 when starting, and for example, only the clutch C1 is engaged when returning from the neutral control described later. Thus, the clutch C1 functions as a starting clutch. The gear ratio γGS (= the rotational speed N _IN of the input shaft 26 / the rotational speed N _OUT of the output gear 28) of each gear stage GS is determined by the first planetary gear device 16, the second planetary gear device 20, and the third planetary gear device. Each gear ratio of the gear unit 22 (= the number of teeth of the sun gear / the number of teeth of the ring gear) is appropriately determined by ρ1, ρ2, and ρ3.

  The clutches C1 and C2 and the brakes B1 to B3 (hereinafter simply referred to as the clutch C and the brake B unless otherwise distinguished) are controlled by a hydraulic actuator such as a multi-plate clutch or a brake. This is a hydraulic friction engagement device that transmits the motive power to the drive wheel 38 side. The engagement and release states of the clutches C and the brakes B are switched by excitation, non-excitation, and current control of the linear solenoid valves SL1 to SL5 (see FIGS. 3 and 4) in the hydraulic control circuit 110. The transient engagement hydraulic pressure at the time of release is controlled.

FIG. 3 is a block diagram for explaining a main part of an electrical control system provided in the vehicle 10 for controlling the engine 30, the automatic transmission 12, and the like. In Figure 3, the vehicle 10, for example power transmission suppressing power transmission path from the engine 30 to lower the C1 clutch pressure P _C1 is engaging pressure corresponding to the transmission torque capacity of the clutch C1 to the drive wheels 38 An electronic control device 50 including a control device capable of executing neutral control to be in a state is provided. The electronic control unit 50 includes a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like, for example, and the CPU stores a program stored in the ROM in advance using a temporary storage function of the RAM. Various control of the vehicle 10 is executed by performing signal processing according to the above. For example, the electronic control unit 50 performs output control of the engine 30, shift control of the automatic transmission 12, torque capacity control of the lockup clutch 33, and the like, and engine control for engine control is performed as necessary. The apparatus is divided into a hydraulic control apparatus for shifting control of the automatic transmission 12, a hydraulic control apparatus for controlling hydraulic pressure of the lockup clutch 33, and the like.

In the electronic control unit 50, for example, a signal representing the hydraulic oil temperature TH _OIL which is the temperature of the hydraulic oil (for example, a known ATF) in the hydraulic control circuit 110 detected by the hydraulic oil temperature sensor 52 is detected by the accelerator opening sensor 54. A signal indicating the accelerator opening degree Acc, which is an operation amount of the accelerator pedal 56 as an acceleration request amount (driver request amount) for the vehicle 10 by the driver, and a rotation speed of the engine 30 detected by the engine rotation speed sensor 58. a signal indicative of the engine rotation speed N _E, a signal representing the cooling water temperature TH _W of the engine 30 detected by a coolant temperature sensor 60, a signal representing the intake air quantity Q of the engine 30 detected by an intake air amount sensor 62, a throttle valve Shin representing the throttle valve opening theta _TH is a degree of opening of the electronic throttle valve detected by the opening sensor 64 , A signal representative of the output speed N _OUT is the rotational speed of the output gear 28 corresponding to the vehicle speed V detected by the vehicle speed sensor 66, in a foot brake operation is a service brake, which is detected by a brake switch 68 (depressing in ) Indicating the operation (brake on) B _ON of the foot brake pedal 70, indicating the lever position (operation position, shift position) P _SH of the shift lever 74 detected by the lever position sensor 72, turbine rotation speed sensor A signal representing an output rotational speed of the torque converter 32 detected by 76, that is, a turbine rotational speed N _T that is a rotational speed of the turbine shaft (that is, an input rotational speed N _IN that is a rotational speed of the input shaft 26) is supplied. .

Further, the electronic control unit 50, for example, as an engine output control command signal S _E for the output control of the engine 30, driving signals to a throttle actuator for controlling the opening and closing of the electronic throttle valve in accordance with the accelerator opening Acc In addition, an injection signal for controlling the fuel injection amount injected from the fuel injection device, an ignition timing signal for controlling the ignition timing of the engine 30 by the igniter, and the like are output. Further, for example, as a hydraulic control command signal S _P output for shift control of the automatic transmission 12, the excitation of the linear solenoid valve SL1~SL5 the hydraulic control circuit 110 to switch the gear position GS of the automatic transmission 12, the non-excitation valve command signals for controlling the (hydraulic pressure command signal, oil pressure command value, the drive signal), etc. or a hydraulic command signal to the linear solenoid valve SLT for Gosuru the regulation control such as the first line pressure P _L1 is output . Further, for example, engagement of the lock-up clutch 33, release, slip _N S as a lock-up control command signal _{S L} for controlling the ₍₌ N E -N _T), a solenoid valve provided in the hydraulic control circuit 110 A hydraulic pressure command signal for driving the SL and the linear solenoid valve SLU is output to the hydraulic pressure control circuit 110.

  The shift lever 74 is disposed in the vicinity of the driver's seat, for example, and is manually operated to five lever positions “P”, “R”, “N”, “D”, or “S” as shown in FIG. It has become so. The “P” position (range) releases a power transmission path in the automatic transmission 12, that is, a neutral state (neutral state) in which the power transmission in the automatic transmission 12 is interrupted, and is mechanically output by the mechanical parking mechanism. This is a parking position (position) for preventing (locking) the rotation of 28. The “R” position is a reverse travel position (position) for making the rotation direction of the output gear 28 of the automatic transmission 12 reverse. The “N” position is a neutral position (position) for achieving a neutral state in which power transmission in the automatic transmission 12 is interrupted. Further, the “D” position is a shift range (D range) that allows the automatic transmission 12 to shift, and uses all the forward gears from the first speed gear stage “1st” to the sixth speed gear stage “6th”. This is a forward travel position (position) at which automatic shift control is executed. The “S” position is a forward travel position (position) in which manual shift can be performed by switching among a plurality of types of shift ranges that limit the change range of the gear steps, that is, a plurality of types of shift ranges with different gear ranges on the high vehicle speed side. is there.

  The “D” position is an automatic transmission mode, which is a control mode in which automatic transmission control is performed in the range from the first gear to the sixth gear as shown in FIG. The “S” position is a lever position to be selected, and the automatic transmission control is executed within a range not exceeding the highest speed gear of each shift range of the automatic transmission 12 and the shift changed by manual operation of the shift lever 74 It is also a lever position for selecting a manual shift mode that is a control mode in which the manual shift control is executed based on the range (that is, the highest speed gear stage). In this embodiment, the shift range on the highest speed side is set (shift range fixed) by operating the shift lever 74 to the “S” position, but based on the operation of the shift lever 74. The gear position (gear stage) may be designated (gear stage fixed). In this case, every time a manual shift operation is performed in the automatic transmission 12, the shift control is executed so that a desired gear stage corresponding to the operation is obtained.

FIG. 4 shows a main part of the hydraulic control circuit related to the linear solenoid valves SL1 to SL5 for controlling the operation of the hydraulic actuators (hydraulic cylinders) ACT1 to ACT5 of the clutches C1 and C2 and the brakes B1 to B3 in the hydraulic control circuit 110. FIG. In FIG. 4, the hydraulic pressure supply device 112 adjusts the first line hydraulic pressure P _L1 using the hydraulic pressure generated from the mechanical oil pump 40 (see FIG. 1) that is rotationally driven by the engine 30 as a source pressure. a regulator valve (first pressure regulating valve) 114, a secondary regulator valve (second pressure regulating valve) 116 for pressurizing the second line pressure P _L2 tone as source pressure the hydraulic pressure discharged from the primary regulator valve 114, a throttle valve opening Since the first line hydraulic pressure P _L1 and the second line hydraulic pressure P _L2 are regulated according to the engine load or the like represented by θ _TH or the intake air amount Q, the signal pressure is applied to the primary regulator valve 114 and the secondary regulator valve 116. a linear solenoid valve SLT for supplying P _SLT, first line pressure _{P L} And a modulator valve 118 for pressurizing is regulated to a constant value a modulator pressure P _M as source pressure. Further, the hydraulic pressure supply device 112 includes a manual valve 120 that can switch an oil path mechanically or electrically based on an operation of the shift lever 74. The manual valve 120, for example, when the shift lever 74 is operated to the "D" position or "S" position, outputs the first line pressure P _L1 inputted as a drive oil pressure P _D, the shift lever 74 is "R when operated to "position, and outputs the first line pressure P _L1 inputted as a reverse pressure P _R, when the shift lever 74 is operated to the" P "position or the" N "position, shuts off the hydraulic pressure of the output to (leads to drive hydraulic _{P D} and the reverse hydraulic _{P R} to the discharge side). Thus, the hydraulic pressure supply device 112, the first line pressure _{P L1,} second line pressure _{P L2,} modulator pressure _{P M,} and outputs a drive oil pressure _{P D,} and reverse hydraulic _{P R.}

The hydraulic control circuit 110 is provided with linear solenoid valves SL1 to SL5 (hereinafter referred to as linear solenoid valves SL unless otherwise specified) corresponding to the hydraulic actuators ACT1 to ACT5. Hydraulic actuators ACT1, ACT2, ACT3, the ACT5, the corresponding linear solenoid valve SL1, SL2, SL3, SL5, the drive oil pressure _{P D} supplied from each of the hydraulic pressure supply device 112 is the command signal from the electronic control unit 50 The pressures are adjusted to C1 clutch pressure P _C1 , C2 clutch pressure P _C2 , B1 brake pressure P _B1 , and B3 brake pressure P _B3 , which are the engagement hydraulic pressures (clutch pressure, brake pressure) according to (hydraulic command value), respectively. Supplied directly. Further, each hydraulic actuator ACT4 adjusts the first line hydraulic pressure P _L1 supplied from the hydraulic pressure supply device 112 to the B2 brake pressure P _B2 corresponding to the command signal from the electronic control device 50 by the corresponding linear solenoid valve SL4. Pressurized and supplied directly. Incidentally, the hydraulic actuator ACT5 brake B3, either the B3 brake pressure P _B3 or the reverse hydraulic pressure P _R pressure regulated by the linear solenoid valve SL5 is adapted to be supplied via the shuttle valve 122.

The linear solenoid valves SL1 to SL5 basically have the same configuration, and the hydraulic pressure supplied to the hydraulic actuators ACT1 to ACT5 is independently controlled by the electronic control unit 50 being independently excited, de-energized, and current controlled. To control the clutch pressures P _C1 and P C2 of the clutches _C1 and _C2 and the brake pressures P _B1 , P _B2 and P _B3 of the brakes _B1 , _B2 and _B3 , respectively. For example, if the clutch C1 as an example, C1 clutch pressure P _C1 corresponding to the drive current I _SL1 corresponding to the hydraulic pressure command value output from the electronic control unit 50 is output from the linear solenoid valve SL1. In the automatic transmission 12, for example, each gear stage GS is established by engaging a predetermined engagement device as shown in the engagement operation table of FIG. In the shift control of the automatic transmission 12, a so-called clutch-to-clutch shift is performed by, for example, re-engaging the disengagement side frictional engagement device and the engagement side frictional engagement device of the clutch C and brake B involved in the shift. The At the time of this clutch-to-clutch shift, the release transient engagement hydraulic pressure of the release side frictional engagement device and the engagement side frictional engagement device of the engagement side frictional engagement device are set so that the shift is executed as quickly as possible while suppressing the shift shock. The engagement transient engagement hydraulic pressure is appropriately controlled. For example, as shown in the engagement operation table of FIG. 2, in the upshift from the 3rd speed to the 4th speed, the brake B3 is released and the clutch C2 is engaged, so that the release transient hydraulic pressure of the brake B3 is suppressed so as to suppress the shift shock. And the engagement hydraulic pressure of the clutch C2 are appropriately controlled.

FIG. 5 is a functional block diagram for explaining the main part of the control function by the electronic control unit 50. In FIG. 5, the engine output control unit, that is, the engine output control means 80 controls the fuel injection amount by the fuel injection device for the fuel injection amount control, in addition to controlling the opening and closing of the electronic throttle valve by the throttle actuator for the throttle control, for example. and outputs an engine output control command signal S _E for controlling the ignition device such as an igniter for ignition timing control. For example, the engine output control means 80, the estimated value of the engine rotational speed N _E and engine torque T _E and the throttle valve opening theta _TH as shown in FIG. 6 as a parameter (hereinafter estimated engine torque) in advance experiments with T E _' manner sought controls the opening and closing of the electronic throttle valve so that the throttle valve opening theta _TH which target engine torque T _E ^* obtained based on the actual engine rotational speed N _E from the stored relationship (engine torque map) In addition, the fuel injection amount by the fuel injection device is controlled, and an ignition device such as an igniter is controlled. The target engine torque T _E ^* is determined by the electronic control unit 50 so as to increase as the accelerator opening Acc increases, for example, based on the accelerator opening Acc corresponding to the requested acceleration amount. Corresponds to torque. In the engine torque map as shown in FIG. 6, parameters corresponding to other engine loads such as the intake air amount Q may be used _instead of the throttle valve opening θ _TH .

The shift control unit, that is, the shift control means 82, for example, from the relationship (shift map, shift map) stored in advance with the vehicle speed V and the accelerator opening Acc as variables as shown in FIG. The shift determination is performed based on the vehicle state indicated by, and it is determined whether or not the shift of the automatic transmission 12 should be executed. Then, the shift control means 82 determines a gear stage to be shifted in the automatic transmission 12, and outputs a shift command for executing the automatic shift control of the automatic transmission 12 so that the determined gear stage is obtained. For example, the shift control means 82 engages and / or releases the hydraulic friction engagement device involved in the shift of the automatic transmission 12 so that the gear stage is achieved according to the engagement table shown in FIG. command signal and outputs the (shift output command value) _{S P} to the hydraulic control circuit 110.

In the shift map of FIG. 7, the solid line is a shift line (upshift line) for determining an upshift, and the broken line is a shift line (downshift line) for determining a downshift. The shift line in the shift map of FIG. 7 is, for example, whether or not the actual vehicle speed V crosses the line on the horizontal line indicating the actual accelerator opening Acc (%), that is, the value (shift point to be changed) on the shift line. This is for determining whether or not the vehicle speed (V _S ) has been exceeded, and is also stored in advance as a series of this value V _S, that is, the shift point vehicle speed.

The hydraulic control command signal _SP is a torque command value for controlling the engagement hydraulic pressure (clutch pressure, brake pressure) corresponding to the transmission torque capacity (clutch torque, brake torque, engagement torque) of the clutch C or the brake B. That is, a hydraulic pressure command value for generating an engagement hydraulic pressure that obtains a necessary transmission torque capacity, for example, a necessary value for releasing the release side frictional engagement device as a torque command value of the release side frictional engagement device. A hydraulic pressure command value for discharging hydraulic oil is output so that a transmission torque capacity can be obtained, and a necessary value for engaging the engagement side frictional engagement device as a torque command value of the engagement side frictional engagement device. A hydraulic pressure command value to which hydraulic oil is supplied so as to obtain a transmission torque capacity is output. Further, at the time of non-shifting in which any gear stage GS of the automatic transmission 12 is maintained, an engagement hydraulic pressure that can maintain a frictional force that can withstand the transmission input torque _TIN (that is, can secure a transmission torque capacity) is generated. The hydraulic pressure command value is output. The hydraulic control circuit 110, in accordance with the hydraulic pressure control command signal S _P by the shift control unit 82, so as the shift of the automatic transmission 12 is executed, or the current gear position GS of the automatic transmission 12 is maintained, The linear solenoid valves SL1 to SL5 in the hydraulic control circuit 110 are operated to operate the hydraulic actuators ACT1 to ACT5 of the hydraulic friction engagement device involved in the establishment (formation) of the gear stage GS.

The transmission input torque _TIN is, for example, torque input to the automatic transmission 12 via the torque converter 32, that is, transmission torque transmitted to the input side of the clutch C1. The transmission input torque T _IN is converted into an estimated engine torque TE ′ calculated based on the actual engine speed _NE and the throttle valve opening θ _TH from an engine torque map as shown in FIG. It is calculated as a torque (= T _E ′ × t) multiplied by a torque ratio t (= turbine torque T _T / pump torque T _P ). Further, the torque ratio t of the torque converter 32 is, for example, a speed ratio e (= turbine rotational speed N _T / pump rotational speed N _P (engine rotational speed N _E )), torque ratio t, efficiency η, and capacity coefficient C. Is calculated based on the actual speed ratio e from a known relationship (not shown) (a map, a predetermined operation characteristic diagram of the torque converter 32) that is experimentally obtained and stored in advance.

  Here, in the vehicle 10 of the present embodiment, for example, neutral control is executed in order to reduce the idling load of the engine 30 while the vehicle is stopped. In this neutral control, for example, when a predetermined neutral control condition set in advance is satisfied, the power transmission path in the automatic transmission 12 is suppressed by setting the clutch C1, which is a starting clutch, to a predetermined slip state or released state. This is control for setting the state (that is, the state substantially equivalent to the power transmission cutoff state or the power transmission cutoff state). The predetermined slip state of the clutch C1 is a state equivalent to a disengaged state in which there is a slight slip but little engagement load is generated, that is, there is almost no transmission torque capacity.

Specifically, the neutral control condition determination unit, that is, the neutral control condition determination unit 84 determines whether or not a predetermined neutral control condition is satisfied at the travel position of the shift lever 74, for example. That is, the neutral control condition determination means 84 is a neutral control execution determination means that sequentially determines whether or not to start execution of neutral control by determining whether or not a predetermined neutral control condition is satisfied. The predetermined neutral control condition is, for example, that the vehicle 10 is stopped, the accelerator pedal 56 is not depressed, and the foot brake pedal 70 is depressed. For example, when the lever position P _SH is the “D” position, the neutral control condition determination means 84 is a predetermined vehicle speed zero determination value for determining whether the vehicle is stopped, and the accelerator opening Acc is accelerator-off. When a predetermined opening degree zero determination value for determination and a signal indicating operation (ON) B _ON is output from the brake switch 68, it is determined that the neutral control condition is satisfied.

Further, the neutral control condition determining means 84 determines whether or not to release (end) the neutral control by determining whether or not the predetermined neutral control condition is satisfied during the neutral control by the neutral control means 86 described later. This is also a neutral control release determination means for sequentially determining whether or not to return from neutral control. For example, the neutral control condition determining unit 84 is a predetermined unit that determines that, for example, the lever position P _SH is operated from the “D” position or the accelerator pedal 56 is depressed during the neutral control by the neutral control unit 86. In the case of brake-off in which the signal indicating the operation (ON) B _ON is no longer output from the brake switch 68 or the brake opening is not made, the neutral control release start is determined.

For example, when the neutral control condition determining unit 84 determines that the predetermined neutral control condition is satisfied at the “D” position of the shift lever 74, the neutral control unit, that is, the neutral control unit 86 changes the first speed gear stage. A neutral control execution command for setting the clutch C1, which is an engagement device to achieve, to a predetermined slip state or release state is output to the shift control means 82, and the power transmission path including the automatic transmission 12 is set to the power transmission suppression state or Neutral control (N control) is executed to cut off the power transmission. The shift control means 82, according to the neutral control execution command, sets a predetermined release pattern as a set pressure during normal N control that is set in advance to bring the clutch C1 into a predetermined slip state or release state, that is, a hydraulic command for the clutch C1. outputting a clutch release command to lower the C1 clutch pressure _{P C1} to the hydraulic control circuit 110 according to the value _{S PC1.} When the power transmission in the automatic transmission 12 is suppressed or interrupted (released), the load on the rear stage (downstream side) of the torque converter 32 is suppressed, and the torque converter 32 rotates substantially integrally so that the engine 30 rotates. The idling load of the vehicle is suppressed, and fuel efficiency and NVH (noise / vibration / riding comfort) performance are improved. As described above, in the neutral control, the clutch C1 is brought into a released state (or a state just before engaging so as to be slightly slip-engaged), so that the power transmission path in the automatic transmission 12 is substantially released. At the same time, a start standby state in which the vehicle can start immediately by switching from half-engagement to engagement of the clutch C1 is set.

Further, for example, when the neutral control condition determination unit 84 determines that the neutral control release is started during the neutral control, the neutral control unit 86 sets the power transmission path including the automatic transmission 12 in a power transmission enabled state. In addition, a neutral control release command for increasing the clutch torque capacity of the clutch C1, which is the engagement side engagement device for the first gear, is output to the shift control means 82, and the neutral control is released (end). That is, return from neutral control. The shift control means 82 is a predetermined engagement pattern as a set pressure at the time of releasing the normal N control that is set in advance to bring the clutch C1 into the engaged state in accordance with the neutral control release command, that is, the hydraulic pressure command value S of the clutch C1. It outputs a clutch engagement command to raise the C1 clutch pressure _{P C1} to the hydraulic control circuit 110 according to _PC1.

  By the way, the N control is executed while the vehicle is stopped. In order to further improve the fuel efficiency, the N control is performed not only when the vehicle is stopped, but also when the vehicle is running, for example, when the vehicle is decelerated with the accelerator off. Is desired to perform. However, in N control (N running control) executed while the vehicle is decelerating, unlike the N control (normal N control) executed while the vehicle is stopped, for example, the engine braking force decreases during decelerating running. There may be a sense of incongruity due to a change in the deceleration at. In the case of re-acceleration when canceling the N control during traveling, the same return control as when re-starting from the stop of the vehicle is performed. For example, the drive torque rises due to the response delay of the clutch engagement during the re-acceleration. There is a possibility that the engagement shock will increase if the feeling of stickiness becomes larger than that at the time of restart, and if clutch engagement is made earlier in order to suppress the feeling of stickiness. As described above, when N control is started while the vehicle is running, fuel efficiency can be improved. there is a possibility.

  Therefore, in this embodiment, the following control method (control idea) is introduced in order to solve the above problems. In other words, regarding the N control during traveling, the N control during traveling is described below for the purpose of improving drivability, such as suppression of discomfort associated with execution of the N control during traveling, improvement of the feeling of stickiness when the accelerator is depressed again, and suppression of engagement shock. As shown in FIG. 4, it is divided into four states (four phases). Then, hydraulic control is performed in consideration of accelerator depressing according to each state. In the following description, for the sake of convenience, the term “clutch” includes the clutch C and the brake B, and the term “clutch pressure” corresponding to the transmission torque capacity of the clutch includes the clutch pressure and the brake pressure.

First, as the control of the state [1] (phase 1 control), for example, the current gear stage GS is formed while the accelerator stage is decelerated while the gear stage GS of the automatic transmission 12 is established. The starting clutch that is the clutch, that is, the clutch C1, and the other clutch that forms the current gear stage GS are both brought into a pressure-controlled state. This is performed as a preparation for executing the control of the state [2] to be described later, that is, a preparation for starting the gradual decrease of the clutch pressure in the control of the state [2]. Therefore, here, the clutch pressure is set so as not to slip even if the accelerator is depressed again. In other words, the clutch pressure of the clutch that forms the current gear stage GS is different from each clutch even if the accelerator is turned on from each maximum clutch pressure corresponding to each maximum transmission torque capacity for complete engagement of each clutch. The clutch pressure is reduced to each predetermined clutch pressure β corresponding to each predetermined transmission torque capacity that has been experimentally obtained and set in advance as a clutch pressure that does not cause rotation. Until the control of the state [2] is started, the clutch pressure of each clutch forming the current gear stage GS is maintained at the predetermined clutch pressure β. Further, when the accelerator is depressed again in this state [1], for example, slip (differential rotation) does not occur in each clutch forming the current gear stage GS. Is quickly increased to the maximum clutch pressure. Therefore, in this phase 1 control, the current gear stage GS is formed as it is without clutch slipping, and the uncomfortable feeling due to the change in deceleration, the feeling of jerking at the time of reacceleration, the engagement shock at the time of releasing the N control, etc. are suppressed. The Further, since the current gear stage GS is preferably formed by at least the engagement of the starting clutch, that is, the clutch C1, the vehicle speed V at which the first to fourth gear stages are formed during deceleration. The following may be used as a condition for starting the state [1]. Further, when the known fuel cut control to stop the fuel supply to the engine 30 during deceleration is executed, predetermined reset engine speed N _E and the predetermined recovery turbine rotating the fuel cut control is released it may be a condition for starting the state [1] which is equal to or less than the engine speed N _E and the turbine rotational speed N _T as below the speed N _T.

Here, the vehicle speed V will be considered. In the present embodiment, the vehicle speed V is represented by the output rotational speed N _OUT , but the rotational speed that uniquely corresponds to the vehicle speed V (N _OUT ) on a one-to-one basis is treated as an agreement with the vehicle speed V as a vehicle speed related value. For example, as a vehicle speed related value, not only the vehicle speed V (output rotation speed N _OUT ), but also the turbine rotation speed N _T (input rotation speed N _IN ) uniquely restricted by the rotation on the drive wheel 38 side, the axle 36 The rotation speed of When the gear stage GS is not completely formed because the clutch C1 is not engaged or the like, the turbine rotation speed N _T (input rotation speed N _IN ) is 1: 1 with the vehicle speed V (N _OUT ). Does not correspond. Therefore, separately from the actual turbine rotation speed _NT detected by the sensor, the turbine rotation speed N _T (input rotation speed N _IN ) converted from the output rotation speed N _OUT and the gear ratio γGS at the gear stage GS (= γGS × N _OUT ) is treated as a vehicle speed related value and is agreed with the vehicle speed V. For example, the current gear ratio input rotation speed N _INN (= γGSN × N _OUT ) calculated based on the output rotation speed N _OUT and the current gear ratio γGSN at the current gear stage GSN of the automatic transmission 12 or the output rotation speed N _The starting gear ratio input rotational speed N _INS (= γGSS × N _OUT ) calculated based on OUT and the speed ratio γGSS at the time of starting in the gear stage GSS (that is, the first gear) of the automatic transmission 12 at the time of starting Treated as a vehicle speed related value.

Following the state [1], as the control of the state [2] (phase 2 control), for example, when the current gear ratio input rotational speed N _INN becomes equal to or lower than the predetermined rotational speed 2 as the second predetermined vehicle speed related value during reduced speed traveling. In the state where the current gear stage GSN of the automatic transmission 12 is maintained, the C1 clutch pressure is gradually decreased from the predetermined clutch pressure β according to the decrease in the vehicle speed V, that is, gradually decreased, and the clutch C1 is brought into a sliding state. This gradual decrease of the C1 clutch pressure is, for example, control for weakening the engine braking force. Therefore, considering at what time point the gradual decrease is started and the gradient is gradually decreased, the uncomfortable feeling due to the change in deceleration is suppressed. A decrease gradient corresponding to a decrease in the vehicle speed V of the C1 clutch pressure at the time of the predetermined rotation 2 or gradual decrease is experimentally obtained and set in advance. Thus, the phase 2 control is, for example, a process of gradually bringing the output torque T _OUT (eg, deceleration torque including engine brake torque (negative torque)) closer to zero. Further, when the accelerator is stepped on again in this state [2], for example, the clutch C1 is in a weak slip state (weak slip state), so that blow (rotation increase) of the turbine rotational speed _NT may occur. There is sex. On the other hand, there is a concern about engagement shock if the clutch C1 is engaged early in order to suppress blowing of the turbine rotational speed _NT . Therefore, the C1 clutch pressure is increased more than in the case of the state [1], and the torque fluctuation is smoothed by the fluctuation of the output torque _TOUT . For example, the C1 clutch pressure is increased to the maximum clutch pressure with a predetermined rising gradient that is experimentally obtained in advance and set so as to suppress the engagement shock while suppressing the blow of the turbine rotational speed _NT . For the other clutch other than the clutch C1 forming the current gear stage GS, the clutch pressure is quickly increased to the maximum clutch pressure. Therefore, in this phase 2 control, the clutch C1 is brought into the slip state, so that the turbine rotational speed _NT is changed to the idle rotational speed N _EIDL of the engine 30 at a changing speed faster than the decreasing speed of the current gear ratio input rotational speed N _INN. It is lowered. In addition, since the control is performed to decrease the C1 clutch pressure from the regulated state, the control is started more quickly than when the control is started from the maximum clutch pressure. In addition, a sudden change in the output torque T _OUT is prevented. Therefore, a sense of incongruity due to a change in deceleration, a feeling of rattling during re-acceleration, an engagement shock when releasing N control, and the like are suppressed.

Following the state [2], as the control of the state [3] (phase 3 control), for example, when the C1 clutch pressure is gradually decreased with the automatic transmission 12 in the current gear stage GSN, the vehicle is decelerating. When the actual turbine rotational speed _NT becomes _equal to or _lower than the second predetermined rotational speed (N _EIDL + α) in the vicinity of the idle rotational speed N _EIDL higher than the idle rotational speed N _EIDL of the engine 30, the clutch C1 is released. Thus, the C1 clutch pressure is reduced. However, here, in order to ensure re-acceleration performance, the C1 clutch pressure is kept at the lowest hydraulic pressure that can be adjusted. That is, the C1 clutch pressure is held at the second predetermined clutch pressure α corresponding to the second predetermined transmission torque capacity as low as possible so that the C1 clutch pressure can be quickly increased to the maximum clutch pressure when the accelerator is on. The second predetermined rotation speed (N _EIDL + α) is, for example, when the turbine rotation speed N _T is lower than the engine rotation speed N _E maintained at the idle rotation speed N _EDL during deceleration traveling, the output torque T _OUT becomes a negative torque. The torque is switched from the positive torque to the positive torque, and there is a possibility that the shock of the gear of the drive train is felt or that the driving force is changed in the direction in which the driving force is generated. Thus, a predetermined value is set to define the point in time when the transmission of the driving force is shut down, and a predetermined margin α is added to the idle rotational speed _NEIDL . For example, the second predetermined clutch pressure α is _tested in advance as a clutch pressure as low as possible within a range in which the idle torque T _EIDL output when the engine 30 is maintained at the idle speed N _EIDL can be transmitted. This is the clutch pressure that is determined and set automatically. In this phase 3 control, in addition to maintaining the C1 clutch pressure at the second predetermined clutch pressure α, the automatic transmission 12 is moved from the current gear stage GSN to the gear stage GSS ( That is, the gear is shifted to the first gear. Thus, here, in order to improve the re-acceleration performance, the shift output is set to the first gear, and the clutch C1 is kept in a pressure-controlled state. At this time, since the starting gear ratio input rotational speed N _INS is higher than the actual turbine rotational speed _NT and the one-way clutch F1 is idling, for example, even if some transmission torque is generated in the clutch C1, the driving is performed. A sense of incongruity caused by the fact that the driving force is not transmitted to the driving wheel and the driving force is switched in the direction in which the driving force is generated is avoided.

  Further, when the accelerator is stepped on again in this state [3], for example, the one-way clutch F1 is in an idling state, and the sudden engagement shock is generated even if the clutch C1 is roughly grasped, that is, suddenly engaged. Therefore, the C1 clutch pressure is quickly increased from the second predetermined clutch pressure α to the maximum clutch pressure. At this time, the automatic transmission 12 may be in the first speed gear stage and the clutch C1 may be kept in a regulated state at the second predetermined clutch pressure α, so that the C1 clutch pressure can be increased more quickly. (2) It is possible to increase the feeling from the predetermined clutch pressure α to the maximum clutch pressure, and to suppress the feeling of stickiness during re-acceleration while suppressing the engagement shock. Therefore, in the phase 3 control, a sense of incongruity due to a change in deceleration, a feeling of rattling at the time of reacceleration, an engagement shock at the time of releasing N control, and the like are suppressed.

Subsequent to the state [3], as the control of the state [4] (phase 4 control), for example, when the C1 clutch pressure is held at the second predetermined clutch pressure α, the starting gear ratio input rotational speed during deceleration traveling When N _INS is _equal to or _lower than a predetermined rotational speed (N _EIDL + β) as a predetermined vehicle speed-related value in the vicinity of the idle rotational speed N _EIDL higher than the idle rotational speed N _EIDL of the engine 30, the automatic transmission 12 is The C1 clutch pressure is reduced so that the clutch C1 is completely released in the state of the high gear. Here, in order to improve the hydraulic controllability of the clutch C1 at the time of reacceleration, that is, to release the N control during traveling by the same control as at the time of the normal N control release at the time of reacceleration, to near the piston end pressure The C1 clutch pressure is reduced. The predetermined rotational speed _{(N EIDL} + beta), for example when starting the gear ratio input speed _{N INS} falls below the engine rotational speed _{N E} to be maintained during deceleration to idle rotation speed _{N EIDL,} input side (engine 30 side ) Is switched to the direction of rotationally driving the output side (drive wheel 38 side), and the positive torque of the output torque T _OUT is transmitted to the drive wheel 38 side, whereas the clutch C1 is completely released to transmit the driving force. _Is a predetermined value that is set to define the time point when the _engine is completely shut down, and a predetermined margin β is added to the idle rotation speed _NEIDL . Further, when the accelerator is depressed again in this state [4], for example, since the clutch C1 is in a completely released state, there is a possibility that the turbine rotational speed _NT is blown (rotational increase). On the other hand, when the clutch C1 is quickly engaged in order to suppress the blowing of the turbine rotational speed _NT , a sudden torque fluctuation of the output torque _TOUT becomes a problem. Therefore, for example, the C1 clutch pressure is increased from zero (for example, near the piston end pressure) to the maximum clutch pressure while controlling the blowing amount of the turbine rotational speed _NT , as in the case of the normal N control cancellation. Therefore, in this phase 4 control, a sense of incongruity due to a change in deceleration, a feeling of rattling during reacceleration, an engagement shock when releasing N control, etc. are suppressed. The predetermined rotational speed (N _EIDL + β) as the predetermined vehicle speed-related value and the predetermined rotational speed 2 as the second predetermined vehicle speed-related value have different rotational speeds to be determined (starting gear ratio input rotational speed N _INS). differs between the current gear ratio input speed _{N INN),} if able to re terms of the vehicle speed _{V (N OUT),} towards the predetermined rotation 2 is high it is needless to say than the predetermined rotational speed _{(N EIDL} + _β).

Specifically, referring back to FIG. 5, the neutral control condition determining means 84 determines whether or not a predetermined traveling N control condition is satisfied at the traveling position of the shift lever 74, for example. In other words, the neutral control condition determination means 84 sequentially determines whether or not the execution of the running N control is started by determining whether or not a predetermined running N control condition is satisfied. It is a determination means. The predetermined traveling N control condition is, for example, that the vehicle is traveling and the accelerator pedal 56 is not depressed. For example, when the lever position P _SH is the “D” position, the neutral control condition determining unit 84 is running N when the accelerator opening Acc is a predetermined opening zero determination value for determining accelerator off. It is determined that the control condition is satisfied.

Further, the neutral control condition determination means 84 cancels the running N control by determining whether or not the predetermined running N control condition is satisfied during the running N control by the neutral control means 86 described later. It is also a traveling N control release determination means that sequentially determines whether or not (end) is performed, that is, sequentially determines whether or not to return from the traveling N control. For example, the neutral control condition determination unit 84 determines that, for example, the lever position P _SH is operated from the “D” position or the accelerator pedal 56 is depressed during the N control during traveling by the neutral control unit 86. When it becomes equal to or greater than a predetermined accelerator opening determination value, it is determined whether or not to cancel the N control during traveling.

The traveling N control progress determination unit, that is, the traveling N control progress determination means 88, for example, when the neutral control condition determination means 84 determines that the predetermined traveling N control condition is satisfied, the actual turbine It is determined whether or not the rotation speed _NT is equal to or less than a predetermined rotation 1. The predetermined rotation 1 is one of the conditions for substantially starting the N control during traveling (control in the above state [1]) by the neutral control means 86, and is, for example, the first gear stage GS during deceleration traveling. This is a predetermined turbine rotational speed _NT ′ that is experimentally determined and set in advance as the turbine rotational speed _NT corresponding to the vehicle speed V at which the first to fourth gear stages are formed. Alternatively, in another aspect, the predetermined rotation 1, for example, when a known fuel cut control during deceleration running is performed is below a predetermined reset engine speed N _E for the fuel cut control is released is a predetermined turbine speed N _{T ',} which is set preliminarily obtained experimentally as a turbine rotational speed N _T corresponding to the engine rotational speed N _E as.

Further, the running N control progress determination means 88 determines whether or not the current gear ratio input rotational speed N _INN is equal to or less than a predetermined rotation 2 during execution of the phase 1 control by the neutral control means 86 described later, for example. To do. In addition, the running N control progress determination means 88 determines that the actual turbine rotational speed _NT is equal to or lower than the second predetermined rotational speed (N _EIDL + α), for example, during execution of the phase 2 control by the neutral control means 86 described later. It is determined whether or not. Further, the running N control progress determination means 88, for example, during execution of the phase 3 control by the neutral control means 86 described later, the starting gear ratio input rotation speed N _INS becomes equal to or less than a predetermined rotation speed (N _EIDL + β). It is determined whether or not.

The neutral control means 86, for example, determines that the actual turbine rotational speed _NT is equal to or lower than the predetermined rotation 1 by the running N control progress determination means 88, the clutch of the clutch that forms the current gear stage GS. A phase 1 control execution command for rapidly decreasing the clutch pressure from the maximum clutch pressure to each predetermined clutch pressure β is output to the shift control means 82, and the phase 1 control is executed, that is, the running N control is substantially started. To do. Further, when the neutral control means 86 determines that the current gear ratio input rotation speed N _INN has become equal to or less than the predetermined rotation 2 during execution of the phase 1 control, for example, by the running N control progress determination means 88, In a state where the current gear stage GSN of the automatic transmission 12 is maintained, a phase 2 control execution command for gradually decreasing the C1 clutch pressure from the predetermined clutch pressure β according to the decrease in the vehicle speed V is output to the shift control means 82, and the phase 2 Execute control. Further, the neutral control means 86 determines that the actual turbine rotational speed _NT has become equal to or lower than the second predetermined rotational speed (N _EIDL + α) during the execution of the phase 2 control, for example, by the running N control progress determination means 88. If so, a phase 3 control execution command for shifting the automatic transmission 12 from the current gear stage GSN to the first gear stage is issued while the C1 clutch pressure is quickly reduced to be kept at the second predetermined clutch pressure α. Output to the shift control means 82 to execute the phase 3 control. Further, the neutral control means 86 determines that the starting gear ratio input rotational speed N _INS is equal to or lower than a predetermined rotational speed (N _EIDL + β) during the execution of the phase 3 control, for example, by the traveling N control progress determination means 88. In this case, the C1 clutch pressure is quickly turned from the second predetermined clutch pressure α to zero (for example, the piston end pressure) so as to completely release the clutch C1 with the automatic transmission 12 in the first speed gear stage. A phase 4 control execution command to reduce (to quickly drain the C1 clutch pressure) is output to the shift control means 82, and the phase 4 control is executed.

Further, the neutral control means 86, for example, when the neutral control condition determination means 84 determines that the running N control is released during the execution of the phase 1 control, the clutch of the clutch that forms the current gear stage GS is determined. A phase 1 control release command for quickly increasing the clutch pressure from each predetermined clutch pressure β in the regulated state to the maximum clutch pressure is output to the shift control means 82, and the N control during traveling is released. Further, for example, when the neutral control condition determination unit 84 determines that the running N control is cancelled during execution of the phase 2 control, the neutral control unit 86 is engaged while suppressing the blowing of the turbine rotational speed _NT. The clutch pressure of the other clutch forming the current gear stage GS is increased while the C1 clutch pressure is increased to the maximum clutch pressure at a predetermined rising gradient that is experimentally obtained in advance so as to suppress the combined shock. Is output to the shift control means 82, and the running N control is released. Further, for example, when the neutral control condition determination unit 84 determines that the running N control is started to be released during the execution of the phase 3 control, the neutral control unit 86 quickly adjusts the C1 clutch pressure in the pressure adjustment state. (2) A phase 3 control release command for increasing the clutch pressure α from the predetermined clutch pressure α to the maximum clutch pressure is output to the shift control means 82 to release the N control during traveling. Further, for example, when the neutral control condition determining unit 84 determines that the running N control release is started during the execution of the phase 4 control, the neutral control unit 86 outputs a neutral control release command when the normal N control is released. Similarly, a phase 4 control release command for increasing the C1 clutch pressure from zero (for example, near the piston end pressure) to the maximum clutch pressure while controlling the blow rate of the turbine rotational speed _NT is output to the shift control means 82 to drive the vehicle. Release medium N control.

  FIG. 8 is a flowchart illustrating a control operation of the electronic control device 50, that is, a control operation for executing the N control during traveling while suppressing a decrease in drivability. For example, the control operation is about several msec to several tens msec. It is executed repeatedly with a very short cycle time. FIG. 9 is a time chart corresponding to the control operation of FIG. FIGS. 10 to 13 are time charts when the N control during traveling is canceled during the control operation of FIG. 8. FIG. 10 shows a case of returning from the phase 1 control, and FIG. When returning, FIG. 12 is a diagram showing an example of returning from phase 3 control, and FIG. 13 is a view showing an example of returning from phase 4 control. Note that the thin solid lines in FIGS. 10 to 13 show the changes in the values in FIG. 9 as they are for comparison.

In FIG. 8, first, in S10 corresponding to the neutral control condition determining means 84, it is determined whether or not a predetermined traveling N control condition is satisfied at the traveling position of the shift lever 74, for example. If the determination in S10 is negative, this routine is terminated. If the determination is affirmative, in S20 corresponding to the running N control progress determination means 88, for example, the actual turbine rotational speed _NT is equal to or less than a predetermined rotation 1. It is determined whether or not. If the determination in S20 is negative, the routine is terminated. If the determination is positive, in S30 corresponding to the neutral control means 86, for example, the clutch pressure of the clutch forming the current gear stage GS is set to the maximum clutch pressure. From the first to the predetermined clutch pressure β, phase 1 control is executed, that is, the running N control is substantially started (time t1 in FIG. 9). Next, in S40 corresponding to the traveling N control progress determination means 88, it is determined whether or not the current gear ratio input rotational speed _NINN is equal to or lower than a predetermined rotation 2, for example. If the determination in S40 is negative, this routine is terminated. If the determination is positive, in S50 corresponding to the neutral control means 86, for example, the C1 clutch is maintained while maintaining the current gear stage GSN of the automatic transmission 12. Phase 2 control for gradually decreasing the pressure from the predetermined clutch pressure β according to the decrease in the vehicle speed V is executed (at time t2 in FIG. 9). If it is determined that the N control during driving is determined to be canceled when the determination in S40 is negative (from time t1 to time t2 in FIG. 10), for example, the clutch that forms the current gear stage GS The N control during traveling is canceled by releasing the phase 1 control that quickly increases the clutch pressure from each predetermined clutch pressure β in the regulated state to the maximum clutch pressure. Next, in S60 corresponding to the traveling N control progress determination means 88, it is determined, for example, whether or not the actual turbine rotational speed _NT is equal to or lower than a second predetermined rotational speed (N _EIDL + α). If the determination in S60 is negative, the routine is terminated. If the determination is positive, in S70 corresponding to the neutral control means 86, for example, the C1 clutch pressure is quickly reduced and held at the second predetermined clutch pressure α. At the same time, phase 3 control for shifting the automatic transmission 12 from the current gear stage GSN to the first gear stage is executed (at time t3 in FIG. 9). Note that if it is determined that the N-control during travel is started when the determination in S60 is negative (from time t2 to time t3 in FIG. 11), for example, the C1 clutch pressure is increased to the maximum clutch with a predetermined upward gradient. The N control during traveling is released by releasing the phase 2 control that increases the pressure to the maximum pressure and at the same time quickly increases the clutch pressure of the other clutch forming the current gear stage GS to the maximum clutch pressure. Next, in S80 corresponding to the traveling N control progress determination means 88, it is determined whether, for example, the starting gear ratio input rotational speed N _INS is equal to or lower than a predetermined rotational speed (N _EIDL + β). If the determination in S80 is negative, this routine is terminated. If the determination is positive, in S90 corresponding to the neutral control means 86, for example, the clutch C1 is engaged with the automatic transmission 12 in the first gear. Phase 4 control is executed to quickly decrease the C1 clutch pressure from the second predetermined clutch pressure α toward zero (for example, piston end pressure) so as to be completely released (at time t4 in FIG. 9). Note that, when the determination of S80 is negative and the start of cancellation of the N control during traveling is determined (from time t3 to time t4 in FIG. 12), for example, the C1 clutch pressure is quickly adjusted in the first pressure adjustment state. 2. The N control during traveling is canceled by releasing the phase 3 control for increasing the clutch pressure α from the predetermined clutch pressure α to the maximum clutch pressure. Further, when it is determined that the running N control is released during the execution of S90 (time t4 to time t5 in FIG. 9) until the vehicle is stopped (time t4 to time t5 in FIG. 13), for example, In the same way as the neutral control release command when the normal N control is released, the C4 clutch pressure is increased from zero (for example, near the piston end pressure) to the maximum clutch pressure while controlling the blow rate of the turbine rotational speed _NT. N control during traveling is released.

As described above, according to this embodiment, the C1 clutch pressure is gradually reduced (phase 2 control) while the automatic transmission 12 is in the current gear stage GSN while the accelerator is off, and the vehicle is decelerated. C1 clutch so that the clutch C1 is completely released in the state where the automatic transmission 12 is in the first gear when the starting gear ratio input rotational speed N _INS is less than a predetermined rotational speed (N _EIDL + β). Since the pressure is reduced (phase 4 control), for example, when the vehicle speed V is at a certain level, the output torque T _OUT (for example, engine brake torque) is gradually decreased as the C1 clutch pressure gradually decreases, and the driver feels uncomfortable due to the change in deceleration. It is suppressed. In addition, for example, when the vehicle speed V is at a certain level, the clutch C1 is in a slipping state, and when releasing the N control during traveling by turning on the accelerator, it is possible to suppress the engagement shock and suppress the feeling of rattling during reacceleration. it can. Further, for example, since the output torque T _OUT tends to be substantially zero due to a decrease in the C1 clutch pressure, even if the clutch C1 is completely released during deceleration traveling, the uncomfortable feeling due to the change in deceleration is suppressed. Further, for example, when the starting gear ratio input rotational speed N _INS is equal to or lower than a predetermined rotational speed (N _EIDL + β), the automatic transmission 12 is set to the first speed gear stage and the clutch C1 is released. When the vehicle is released, the N control is released in the same manner as when the vehicle starts after the vehicle stops, so that it is possible to suppress the feeling of rattling during re-acceleration while suppressing the engagement shock. Therefore, it is possible to further improve fuel efficiency by executing neutral control while the vehicle is traveling while suppressing a decrease in drivability. Further, for example, when the output torque T _OUT is switched from negative torque to positive torque during decelerating travel (for example, from the state where the drive wheel 38 side rotates along with the input side of the automatic transmission 12, the input side of the automatic transmission 12 moves from the drive wheel 38. since the place in) the clutch C1 is switched to a state to turn the side is released, are prevented from negative torque is reduced towards substantially zero switched to positive torque by lower C1 clutch pressure, discomfort due to the output torque T _OUT changes Is suppressed.

Further, according to the present embodiment, during the deceleration traveling, the C1 clutch pressure is reduced to the clutch C1 prior to gradually decreasing the C1 clutch pressure (phase 2 control) with the automatic transmission 12 at the current gear stage GSN. Is reduced to a predetermined clutch pressure β that does not cause differential rotation in the clutch C1 even when the accelerator is turned on, so that the current gear ratio input rotational speed N _INN during deceleration traveling is reduced to the predetermined rotation 2 Since the C1 clutch pressure is maintained at the predetermined clutch pressure β (phase 1 control) until the following is reached, it is possible to quickly shift to the phase 2 control, for example. Further, for example, until the current gear ratio input rotational speed N _INN becomes equal to or less than the predetermined rotation 2, the C1 clutch pressure is maintained at the predetermined clutch pressure β, that is, the clutch C1 is kept in a regulated state at the predetermined clutch pressure β. Therefore, when the N control is canceled while the accelerator is on, the C1 clutch pressure can be quickly increased to the maximum clutch pressure without the clutch C1 being in a slip state, thereby suppressing the feeling of rattling during re-acceleration. it can.

Further, according to the present embodiment, when the actual turbine rotational speed _NT during deceleration traveling is equal to or lower than the second predetermined rotational speed (N _EIDL + α) during the execution of the phase 2 control, the clutch C1 is used. Prior to lowering the C1 clutch pressure so as to release (phase 4 control), the C1 clutch pressure is as low as possible so that the C1 clutch pressure can be quickly increased to the maximum clutch pressure when the accelerator is on. While maintaining the predetermined clutch pressure α, the automatic transmission 12 is shifted from the current gear stage GSN to the gear stage GSS at the time of starting (that is, the first gear stage) (phase 3 control). physical disorder by the output torque T _oUT is switched from the negative torque to positive torque, it switched to the direction to which the driving force or feel shock of backlash of the driving system gears exits For what can cause the transmission torque in the clutch C1 is their discomfort, etc. is suppressed by being lowered. For example, even when some transmission torque is generated in the clutch C1, the one-way clutch F1 is idling in the first speed gear stage, so that no driving force is generated and the above-mentioned uncomfortable feeling is avoided. Further, for example, the automatic transmission 12 is set to the first speed gear stage, and the C1 clutch pressure is held at the second predetermined clutch pressure α. It is possible to suppress the feeling of stickiness during re-acceleration. Further, when the N control is released during traveling, the one-way clutch F1 is idling, so that even if the clutch C1 is suddenly engaged, no engagement shock is generated, and the clutch C1 has the second predetermined clutch pressure α. The C1 clutch pressure can be quickly increased because the engine is on standby in the pressure regulation state.

Further, according to the present embodiment, the second predetermined clutch pressure α is a clutch pressure as low as possible capable of transmitting the idle torque T _EIDL of the engine 30, and therefore, for example, the output torque T _OUT is positive from the negative torque. The shock of the gear of the driving system due to switching to torque, the uncomfortable feeling due to switching in the direction in which the driving force is generated, and the like are appropriately suppressed. When the N control during traveling due to the accelerator being on is released, the C1 clutch pressure can be quickly increased.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the automatic transmission 12 is an automatic transmission capable of shifting six forward speeds and one reverse speed. However, the number of shift stages and the internal structure of the automatic transmission are particularly described above. It is not limited to. That is, the present invention can be applied as long as neutral control can be performed and a predetermined engagement device is engaged when neutral control is canceled. For example, the automatic transmission 12 described above is provided with the one-way clutch F1 for establishing the first gear by merely engaging the clutch C1, but such a one-way clutch F1 is provided. The present invention can be applied even to such an automatic transmission. In the case of an automatic transmission that is not provided with such a one-way clutch F1, for example, among the phases 1 to 4 in the N control during traveling, only the phase 3 does not exist, and the same control is performed thereafter. It becomes. Further, the present invention can also be applied to a continuously variable transmission such as a belt type continuously variable transmission as an automatic transmission. In the case of a belt type continuously variable transmission or the like, for example, an engagement device capable of connecting / disconnecting a power transmission path between the engine and the belt type continuously variable transmission or a well-known forward / reverse switching device may be used. The present invention is applied to the provided engagement device or the like. In the case of a belt-type continuously variable transmission, for example, the gear ratio at the time of starting is the maximum gear ratio (minimum speed side gear ratio) γmax or the gear ratio used at the start of the vehicle corresponding to the maximum gear ratio γmax. It becomes.

Further, in the above-described embodiment, various vehicle speed related values are used for the transition determination of each phase in the running N control. However, these are only examples until the tiredness, and if the vehicle speed related values correspond one-to-one, replacement is not possible. Is possible. For example, when the gear stage GS of the automatic transmission 12 is established, the output rotational speed N _OUT (vehicle speed V) or the like may be used instead of the turbine rotational speed _NT . Needless to say, when the determination target is changed, the determination threshold is also changed accordingly.

  In the above-described embodiment, the clutch C1 functioning as the starting clutch is a hydraulic friction engagement device. However, the clutch C1 is not limited thereto, and is not limited to a magnetic clutch such as a powder (magnetic) clutch, an electromagnetic clutch, and a meshing dog clutch. You may be comprised from a powder type, an electromagnetic type, and a mechanical engagement apparatus. For example, in the case of an electromagnetic clutch, the hydraulic control circuit 110 is configured by a switching device, an electromagnetic switching device, or the like that switches an electrical command signal circuit to the electromagnetic clutch, not a valve device that switches an oil passage.

  In the above-described embodiment, the clutch C1 functioning as the starting clutch is a clutch disposed in series with the power transmission path. However, the clutch C1 is not limited thereto, and for example, a planetary gear device disposed in the power transmission path. The present invention can also be applied to a brake that prevents the rotation of one rotating element that constitutes the differential gear device in a power transmission device in which power is transmitted through the differential gear device. In other words, the starting clutch is an engaging device that is engaged when the vehicle starts, and this starting clutch includes not only the clutch but also the brake.

  Further, in the above-described embodiment, the transmission torque capacity of the starting clutch (clutch C1) is increased as the hydraulic pressure command value increases. However, the present invention is not limited thereto. For example, as the hydraulic pressure command value increases, the Even if the transmission torque capacity is controlled to be small, the present invention can be applied. Further, in the case of controlling the transmission torque capacity of the starting clutch via the actuator, for example, the transmission torque capacity of the starting clutch (clutch C1) may be controlled to increase as the action of the actuator increases. Even if the transmission torque capacity is controlled to be smaller as the action by the actuator is larger, the present invention can be applied.

  In the above-described embodiment, the torque converter 32 provided with the lock-up clutch 33 is used as the fluid transmission device. However, a fluid coupling having no torque amplification function may be used.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

12: Automatic transmission 30 for vehicle 30: Engine 32: Torque converter (fluid transmission)
38: Drive wheel 50: Electronic control device (control device)
C1: Clutch (starting clutch)
F1: One-way clutch

Claims (4)

Automatic transmission for a vehicle capable of executing neutral control in which the transmission torque capacity of a starting clutch that transmits engine power to the drive wheel side is reduced so that the power transmission path between the engine and the drive wheel is in a power transmission suppression state. A control device for the machine,
If the transmission torque capacity is gradually reduced with the automatic transmission set to the current gear ratio during acceleration-decelerated traveling, and the vehicle speed-related value during deceleration traveling is less than or equal to a predetermined vehicle speed-related value, Reducing the transmission torque capacity so as to release the starting clutch in a state where the automatic transmission has a gear ratio at the time of starting;
Prior to gradually reducing the transmission torque capacity while the automatic transmission is in the current gear ratio during the deceleration travel, the transmission torque capacity is the maximum transmission torque capacity for engaging the start clutch. To a predetermined transmission torque capacity that does not cause differential rotation in the starting clutch even when the accelerator is turned on, and a vehicle speed related value during the deceleration traveling is equal to or lower than a second predetermined vehicle speed related value that is higher than the predetermined vehicle speed related value. Until this time, the transmission torque capacity is maintained at the predetermined transmission torque capacity.   The idle rotational speed in which the rotational speed on the input side of the automatic transmission calculated based on the vehicle speed related value during the deceleration traveling and the gear ratio at the start of the automatic transmission is higher than the idle rotational speed of the engine 2. The control device for an automatic transmission for a vehicle according to claim 1, wherein the transmission torque capacity is reduced so as to release the starting clutch when the rotation speed becomes equal to or lower than a predetermined rotational speed in the vicinity. In the automatic transmission, a gear stage at the time of starting which is a gear ratio at the time of starting is established by engagement of the starting clutch and the one-way clutch,
The power of the engine is transmitted to the automatic transmission via a fluid transmission device,
When the transmission torque capacity is gradually reduced with the automatic transmission at the current gear ratio, the output rotational speed of the fluid transmission device during the deceleration traveling is higher than the idle rotational speed of the engine. When the transmission torque capacity is reduced below the second predetermined rotation speed in the vicinity of the rotation speed, the transmission torque capacity is reduced when the accelerator is turned on before the transmission torque capacity is reduced so as to release the starting clutch. 2. The second predetermined transmission torque capacity as low as possible that can be quickly raised is maintained, and the automatic transmission is shifted from the current gear to the gear at the start. Or the control apparatus of the automatic transmission for vehicles of 2.   5. The control device for an automatic transmission for a vehicle according to claim 4, wherein the second predetermined transmission torque capacity is a transmission torque capacity as low as possible capable of transmitting the idle torque of the engine.

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