JP5810966B2 - Control device for automatic transmission - Google Patents

Description

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

  Conventionally, vehicles equipped with an automatic transmission between an engine and drive wheels have become widespread. As this type of automatic transmission, one having a fluid transmission mechanism connected to an engine and an automatic transmission mechanism connected to drive wheels connected in series is widely known. As a fluid transmission mechanism, a mechanism including a hydraulic lockup clutch capable of directly connecting an input side and an output side is widely used. The lockup clutch engages or releases between the input side and the output side of the fluid transmission mechanism by a lockup differential pressure that is a differential pressure between the engagement side hydraulic pressure and the release side hydraulic pressure.

  In this automatic transmission control device, there is one that controls the engagement and disengagement of the lockup clutch by continuously changing the lockup differential pressure of the lockup clutch by controlling the linear solenoid valve (for example, patent) Reference 1). In addition, this automatic transmission control device employs flex start control in which a lock-up clutch is slid to start.

  In this automatic transmission control device, when starting the flex start control, the flex start control is performed after executing the precharge control in which the linear solenoid valve is in a standby state instructed with a predetermined command pressure. According to this automatic transmission control device, it is possible to improve control responsiveness and fuel efficiency with respect to flex start control.

JP 2011-106506 A

  However, the conventional automatic transmission control device does not consider garage control when the shift position is switched from the stop position to the travel position. Further, the conventional automatic transmission control device does not consider the case where the linear solenoid valve that controls the lock-up clutch and the linear solenoid valve that controls the starting clutch such as the C1 clutch of the automatic transmission mechanism are shared. It was.

  For this reason, when the linear solenoid valve that controls the lock-up clutch and the linear solenoid valve that controls the starting clutch of the automatic transmission mechanism are shared, an attempt to shift from the garage control to the flex start control is as follows. A problem occurs.

  That is, since the starting clutch is in the engaged state at the end of the garage control, the oil supply pressure Pslu from the linear solenoid valve that controls the starting clutch is high. For this reason, if the control device of the automatic transmission tries to start the flex start control immediately after the garage control ends, high pressure oil is supplied from the linear solenoid valve to the lockup clutch, and the lockup clutch is There was a problem of sudden engagement and shock.

  In order to avoid sudden engagement of the lockup clutch, a signal is input to the linear solenoid valve so as to lower the oil supply pressure from the linear solenoid valve to, for example, 0 MPa after the garage control is finished, If the lock-up clutch is slid, it takes a long time from the end of the garage control to the start of the flex start control. If the driver depresses the accelerator pedal before starting the flex start control and starts the vehicle, the control device of the automatic transmission starts the vehicle without performing the flex start control. There was a problem to do.

  In recent years, in particular, in order to improve fuel efficiency, it is desired that flex start control can be executed quickly even in the extremely low speed region. When shifting from garage control to flex start control, the fuel consumption can be improved by shifting in a short time. It is desired to improve drivability through restraint.

  The present invention has been made to solve such a problem. In a vehicle equipped with an automatic transmission, an automatic transmission that can achieve both improved fuel efficiency and improved drivability in the transition from garage control to flex start control. An object is to provide a control device.

In order to achieve the above object, a control device for an automatic transmission according to the present invention includes (1) a fluid transmission mechanism coupled to a drive source of a vehicle, and an automatic transmission mechanism coupled to the fluid transmission mechanism and drive wheels. The fluid transmission mechanism includes: an input shaft coupled to the drive source; an output shaft coupled to the automatic transmission mechanism; and the input shaft and the output shaft. A lock-up clutch that switches a transmission state between an engagement state to engage, a release state to release the input shaft and the output shaft, and a slip state to slip the input shaft and the output shaft at a predetermined slip ratio; The automatic transmission mechanism is connected to the input shaft connected to the fluid transmission mechanism, the output shaft connected to the drive wheel, the input shaft connected to the fluid transmission mechanism, and the drive wheel. engagement between the output shaft which is Anda starting clutch for switching a transmission state between the released state to release between the engaged state and the hydraulic power transmission mechanism coupled to the drive wheel and the coupling input shaft the output shaft that the locking The up clutch is controlled by the differential pressure between the engagement side hydraulic pressure and the release side hydraulic pressure, and the start clutch is controlled by the start clutch pressure of the supplied oil, and the start clutch is moved from the released state to the stop state when the vehicle is stopped. A control device for an automatic transmission, capable of executing garage control to switch to an engaged state, and capable of executing flex start control for bringing the lock-up clutch into the sliding state when the vehicle starts. And an adjustment valve that adjusts the starting clutch pressure, and when shifting from the garage control to the flex start control, The adjustment pressure of the adjustment valve is lowered to a set pressure larger than 0 so that the lock-up clutch is in the released state, and then the adjustment pressure is increased to bring the lock-up clutch into the sliding state. To do. In this specification, the release state of the starting clutch includes not only complete release but also a state in which power is transmitted with slipping, such as half-engagement.

  With this configuration, the control device for the automatic transmission reduces the adjustment pressure to a set pressure greater than 0 at which the lockup clutch is released by controlling the adjustment valve when shifting from the garage control to the flex start control. . That is, the control device for the automatic transmission reduces the adjustment pressure to such a level that the lockup clutch can maintain the released state without reducing the adjustment pressure to 0 MPa. Then, the control device for the automatic transmission reduces the adjustment pressure so that the lockup clutch is in the released state, then increases the adjustment pressure to make the lockup clutch in the sliding state, and starts the flex start control.

  As a result, the control device for the automatic transmission can reduce the garage control as compared with the conventional case where the adjustment pressure is reduced to 0 MPa after the garage control is finished and then the adjustment pressure is increased again to start the flex start control. It is possible to shorten the time until the adjustment pressure is increased again after completion. Therefore, the control device for the automatic transmission can start the flex start control earlier than the conventional one after the garage control.

  In addition, according to the automatic transmission control device, after the garage control is finished, the flex start control is performed after the adjustment pressure is lowered so that the lockup clutch is in the released state. The occurrence of shock can be suppressed. Thus, according to the automatic transmission control device, the transition from the garage control to the flex start control can be realized more quickly than before, and the smooth transition with the occurrence of shock suppressed can be realized.

  In the control device for an automatic transmission described in (1) above, (2) the set pressure is configured so that at least the engagement force of the lockup clutch is not generated.

  With this configuration, the control device of the automatic transmission can reduce the adjustment pressure to a set pressure that does not generate the engagement force of the lockup clutch after the garage control is completed. For this reason, when the flex start control is started, the lock-up clutch shifts from a state where there is no engagement force to a slip state, so that the occurrence of a shock can be suppressed.

  In the control device for an automatic transmission according to (1) or (2), (3) a lockup clutch control unit that supplies the differential pressure and controls the differential pressure by the adjustment pressure; And a starting clutch control unit that supplies the starting clutch pressure and controls the starting clutch pressure by the adjustment pressure.

  With this configuration, the control device for the automatic transmission can control the differential pressure supplied to the lockup clutch by controlling the adjustment pressure supplied to the lockup clutch control unit, and can also supply the adjustment pressure supplied to the starting clutch control unit. The starting clutch pressure can be controlled by controlling. For this reason, it is possible to execute engagement and release of the lockup clutch and the start clutch by simple control while sharing the control valve for the lockup clutch control unit and the start clutch control unit.

  In the control device for an automatic transmission according to the above (1) or (3), (4) the automatic transmission mechanism is a continuously variable transmission having a forward / reverse switching mechanism, and the starting clutch is It is configured to be a forward clutch provided in the forward change machine. With this configuration, the control device for the automatic transmission can start the flex start control earlier in the continuously variable transmission after the end of the garage control.

  In the automatic transmission control device according to (1) or (3), (5) the automatic transmission mechanism is a stepped transmission having a plurality of clutches and brakes, and the starting clutch is The stepped transmission is configured to be the most clutch on the drive source side. With this configuration, the control device for the automatic transmission can start the flex start control earlier in the stepped transmission after the end of the garage control than before.

  According to the present invention, there is provided a control device for an automatic transmission that can improve both fuel efficiency and drivability in a transition from garage control to flex start control in a vehicle equipped with an automatic transmission. Can be provided.

It is the schematic which shows the vehicle carrying the control apparatus of the automatic transmission which concerns on embodiment of this invention. 1 is a schematic skeleton diagram showing a transmission equipped with a control device for an automatic transmission according to an embodiment of the present invention. It is a block diagram which shows schematic structure of the hydraulic control apparatus which concerns on embodiment of this invention. 1 is a hydraulic circuit diagram showing a schematic configuration of a main part of a hydraulic control apparatus according to an embodiment of the present invention. It is a flowchart which shows operation | movement of the control apparatus of the automatic transmission which concerns on embodiment of this invention. It is a time chart which shows operation | movement of the control apparatus of the automatic transmission which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the configuration will be described.

  As shown in FIG. 1, the vehicle 10 according to the present embodiment includes an engine 11 as a drive source, a transmission 20 as an automatic transmission, a hydraulic control device 30, a differential mechanism 40, and a drive shaft 43. Drive wheel 45 and ECU (Electronic Control Unit) 100. In the present embodiment, the control device for the automatic transmission includes the ECU 100, and includes a torque converter 50 as a fluid transmission mechanism and a continuously variable transmission 70 as an automatic transmission mechanism, which will be described later. The transmission 20 is controlled.

  The engine 11 is composed of a power device that is a known internal combustion engine that outputs power by burning a mixture of hydrocarbon fuel such as gasoline or light oil and air in a combustion chamber of a cylinder (not shown). . The engine 11 is configured to reciprocate the piston in the cylinder by intermittently repeating intake, combustion, and exhaust of the air-fuel mixture in the combustion chamber, and rotate the crankshaft 15 connected to the piston. The fuel used for the engine 11 is not limited to gasoline or light oil, but may be an alcohol fuel containing alcohol such as ethanol. The crankshaft 15 is connected to the transmission 20 and transmits power generated by the engine 11 to the transmission 20.

  The hydraulic control device 30 supplies the oil as hydraulic oil to the transmission 20 and controls the transmission 20 by adjusting the hydraulic pressure of the supplied oil. The hydraulic control device 30 switches hydraulic circuits and controls hydraulic pressure by a plurality of solenoid valves and the like controlled by the ECU 100.

  The drive shaft 43 has a left drive shaft 43L and a right drive shaft 43R. The drive wheel 45 has a left drive wheel 45L and a right drive wheel 45R. The differential mechanism 40 transmits the power transmitted from the transmission 20 to the left drive wheel 45L by rotating the left drive shaft 43L, and transmits the power to the right drive wheel 45R by rotating the right drive shaft 43R. It has become. Thus, the differential mechanism 40 absorbs the difference in the rotational speed between the left drive wheel 45L and the right drive wheel 45R when traveling on a curve or the like.

  The drive wheel 45 includes a metal wheel attached to the drive shaft 43 and a resin tire attached to the outer periphery of the wheel. The drive wheel 45 is rotated by the power transmitted by the drive shaft 43 and causes the vehicle 10 to travel by the frictional action between the tire and the road surface.

  The ECU 100 includes a central processing unit (CPU) as a central processing unit, a read only memory (ROM) that stores fixed data, a random access memory (RAM) that temporarily stores data, and an input interface. An output interface (none of which is shown), an EEPROM (Electrically Erasable and Programmable Read Only Memory) composed of a rewritable nonvolatile memory, and a communication means. The ECU 100 is a vehicle electronic control device that supervises overall control of the vehicle 10.

  For example, the ROM stores a control program, a map, and the like of the automatic transmission according to the present embodiment, and functions as a storage device. The CPU executes arithmetic processing based on the control program and map stored in the ROM. In the present embodiment, the control program for the automatic transmission is executed at predetermined time intervals (for example, 10 ms) by the ECU 100.

  As a program stored in the ROM, for example, a garage control program for switching the forward clutch 64 from the disengaged state to the engaged state when the shift position is switched from the P position or the N position to the D position when the vehicle 10 is stopped, for example. is there. Moreover, as a program memorize | stored in ROM, there exists a flex start control program which makes the lockup clutch 53 a sliding state, for example when the vehicle 10 starts.

  Examples of the map stored in the ROM include a map indicating the relationship between the lockup differential pressure ΔP and the adjustment pressure Pslu, and a map indicating the relationship between the adjustment pressure Pslu and the secondary pressure Psec. Further, the map stored in the ROM includes a primary sheave pressure Pin of an input side hydraulic cylinder 73 of a primary pulley 72, a belt clamping pressure Pd of an output side hydraulic cylinder 78 of a secondary pulley 77, and a continuously variable transmission 70, which will be described later. There is a map showing the relationship between the transmission ratio of the vehicle and the opening of the accelerator pedal 12. Further, the map stored in the ROM includes a map representing an optimum fuel consumption line for obtaining a required torque and a required engine speed at which the target engine output can be achieved with an optimum fuel consumption, a belt clamping pressure Pd, a transmission ratio γ, an accelerator There is a map showing the relationship between the opening of the pedal 12 (hereinafter also referred to as the accelerator opening Acc) and the primary sheave pressure Pin.

  The RAM temporarily stores calculation results by the CPU, data input from various sensors described later, and the like. Further, for example, data that should be saved when the engine 11 is stopped is stored by an EEPROM, a backup memory, or the like that is configured by a non-volatile memory.

  In addition, the ECU 100 measures an elapsed time after the forward clutch 64 is switched to the engaged state when the garage control program is executed. The ECU 100 controls an SC output that is an electric signal for executing the garage control. Further, the ECU 100 controls an SLU output that is an electrical signal for controlling the adjustment pressure Pslu by outputting it to the second linear solenoid valve 340. In addition, the ECU 100 controls an SL output that is an electric signal for controlling the lockup switching valve 420. The ECU 100 outputs these electric signals to a predetermined electric circuit, solenoid valve or the like, and controls each part.

  The CPU, RAM, ROM, input interface, and output interface are connected to each other via a bus. Various sensors are connected to the input interface, and signals detected by these sensors are input. For example, a solenoid valve or the like constituting the hydraulic control circuit 31 (see FIG. 3) is connected to the output interface. The ECU 100 inputs signals from various sensors from the input interface, performs calculations by the CPU with reference to the RAM and ROM as necessary, and outputs from the output interface, thereby executing various controls according to the present embodiment. It is supposed to be.

  The vehicle 10 includes a crank sensor 81, a shift sensor 82, a drive shaft rotational speed sensor 83, an accelerator opening sensor 84, and a brake sensor 88.

  The crank sensor 81 is configured by a crank position sensor that can detect a crank position and a crank angle of the crankshaft 15 to detect an engine rotation speed signal. The crank sensor 81 detects the rotation speed of the crankshaft 15 and converts it into a signal, and inputs the signal to the ECU 100. The ECU 100 acquires the rotational speed of the crankshaft 15 represented by the detection signal input by the crank sensor 81 as the engine rotational speed Ne.

  The shift sensor 82 detects which shift position the shift lever 21 is in various shift positions such as parking (P), reverse (R), neutral (N), drive (D), and low (L). It consists of a shift position sensor. Here, the P position is a shift position at which the shift range of the transmission 20 is set to the parking range. Shift positions other than the P position such as the D position, the N position, and the R position are shift positions that set the shift range of the transmission 20 to a movable range. The shift sensor 82 detects the shift position of the shift lever 21 and converts it into a signal, and inputs the signal to the ECU 100.

  The drive shaft rotational speed sensor 83 detects the rotational speed of the left drive shaft 43L, converts it into a signal, and inputs the signal to the ECU 100. The ECU 100 calculates the traveling speed of the vehicle 10 based on a detection signal representing the rotation speed of the left drive shaft 43L input by the drive shaft rotation speed sensor 83. In the present embodiment, the drive shaft rotational speed sensor 83 detects the rotational speed of the left drive shaft 43L, but is not limited thereto, and may detect the rotational speed of the right drive shaft 43R. Good.

  The accelerator opening sensor 84 is arranged in the vicinity of the accelerator pedal 12 operated by the driver's stepping on, and detects the accelerator opening Acc. The accelerator opening sensor 84 is composed of a linear accelerator position sensor that can obtain an output voltage having a linear relationship with the depression amount of the accelerator pedal 12. The accelerator opening sensor 84 detects the accelerator opening Acc, converts it into a signal, and inputs the signal to the ECU 100. The ECU 100 acquires the accelerator opening Acc represented by the detection signal input by the accelerator opening sensor 84 as an output of the engine 11.

  The brake sensor 88 is disposed in the vicinity of the brake pedal 41 operated by the driver's depression, and detects the depression amount of the brake pedal 41. The brake sensor 88 is constituted by a linear brake position sensor that can obtain an output voltage that is linearly related to the depression amount of the brake pedal 41. The brake sensor 88 detects the depression amount of the brake pedal 41, converts it into a signal, and inputs the signal to the ECU 100.

  Next, the configuration of the transmission 20 will be described with reference to FIG.

  The transmission 20 includes a torque converter 50, a continuously variable transmission (hereinafter simply referred to as CVT: Continuously Variable Transmission) 70, and a reduction gear mechanism 80. The power output from the engine 11 is transmitted to the differential mechanism 40 through a power transmission path of torque converter 50 → CVT 70 → reduction gear mechanism 80, and distributed to the left drive wheel 45L and the right drive wheel 45R. Yes.

  The torque converter 50 is connected to the engine 11 of the vehicle 10. The torque converter 50 includes a pump impeller 51p, a turbine runner 51t, a stator 51s, a front cover 52, an input shaft 50a connected to the crankshaft 15 of the engine 11, and a turbine shaft as an output shaft connected to the CVT 70. 54 and a lock-up clutch 53.

  The pump impeller 51p is connected to the crankshaft 15 via the front cover 52. The turbine runner 51t is connected to the forward / reverse switching machine 60 of the CVT 70 via the turbine shaft 54. The stator 51s is rotatably supported by a non-rotating member via a one-way clutch.

  The pump impeller 51p and the turbine runner 51t are provided to face each other. Opposite portions of the pump impeller 51p and the turbine runner 51t are each provided with a large number of blades and filled with oil. As a result, power is transmitted between the pump impeller 51p and the turbine runner 51t via oil.

  A lockup clutch 53 is provided on the turbine runner 51t. The lockup clutch 53 is attached so as to rotate integrally with the turbine shaft 54 and is configured to be movable in the axial direction of the turbine shaft 54. A release side oil chamber 55 is formed between the lockup clutch 53 and the front cover 52. A release-side oil passage 56 communicates with the release-side oil chamber 55 (see FIG. 4). An engagement side oil chamber 57 is formed between the lockup clutch 53 and the turbine runner 51t. An engagement side oil passage 58 and a drain oil passage 59 communicate with the engagement side oil chamber 57.

  The lock-up clutch 53 engages the input shaft 50a and the turbine shaft 54, disengages the input shaft 50a and the turbine shaft 54, and makes a predetermined slip between the input shaft 50a and the turbine shaft 54. The transmission state is switched between a slipping state that causes slipping at a rate.

  The lockup clutch 53 is driven by a lockup differential pressure ΔP (= Pon−Poff) as a differential pressure between the engagement side hydraulic pressure Pon in the engagement side oil chamber 57 and the release side hydraulic pressure Poff in the release side oil chamber 55. It moves in the direction and is switched to one of three states: an engaged state, a released state, and a sliding state with respect to the front cover 52. The lock-up clutch 53 is designed to improve fuel efficiency by integrally connecting the pump impeller 51p and the turbine runner 51t and rotating them together.

  In the present embodiment, the lockup clutch 53 is in a released state when the lockup differential pressure ΔP is a negative pressure. The lockup clutch 53 is engaged when the lockup differential pressure ΔP is the maximum positive pressure. Further, the lockup clutch 53 is in a slipping state when the lockup differential pressure ΔP is 0 or more and less than the maximum positive pressure.

  The CVT 70 includes a forward / reverse switching device 60, a primary pulley 72, a secondary pulley 77, a belt 75, an input shaft 70 a connected to the torque converter 50, and a secondary shaft 79 as an output shaft connected to the drive wheels 45. And. CVT 70 is connected to torque converter 50 and drive wheel 45.

  The forward / reverse switching machine 60 is constituted by a double pinion type planetary gear device. The forward / reverse switching machine 60 includes a sun gear 61, a carrier 62, a ring gear 63, a forward clutch 64 as a start clutch, and a reverse brake 66.

  Sun gear 61 is coupled to turbine shaft 54 of torque converter 50. The carrier 62 is rotatably connected to the respective rotation shafts of the first pinion gear 67 and the second pinion gear 68 provided between the sun gear 61 and the ring gear 63 and is connected to the primary shaft 71 which is an input shaft of the CVT 70. Has been.

  The forward clutch 64 is provided between the carrier 62 and the sun gear 61, and engages between the input shaft 70 a and the secondary shaft 79 and releases between the input shaft 70 a and the secondary shaft 79. The transmission state is switched between the release state and the release state. The forward clutch 64 is configured to switch the transmission state between the engaged state and the released state by the starting clutch pressure Pc of the supplied oil. The reverse brake 66 is provided between the ring gear 63 and the housing 65, and is switched between an engaged state and a released state by hydraulic pressure.

  In the forward / reverse switching machine 60, when the forward clutch 64 is engaged and the reverse brake 66 is released, the sun gear 61, the carrier 62, and the ring gear 63 are rotated together, and the turbine shaft 54 is moved to the primary shaft. 71 is directly connected. Thereby, the driving force in the forward direction is transmitted from the turbine shaft 54 to the primary shaft 71, and finally transmitted to the drive wheels 45.

  In the forward / reverse switching machine 60, the ring gear 63 is fixed when the forward clutch 64 is disengaged and the reverse brake 66 is engaged. For this reason, the carrier 62 rotates in the opposite direction via the first pinion gear 67 and the second pinion gear 68 with respect to the rotation direction of the sun gear 61 that rotates integrally with the turbine shaft 54. Therefore, since the primary shaft 71 connected to the carrier 62 is rotated in the reverse direction with respect to the turbine shaft 54, the reverse driving force is transmitted to the driving wheel 45.

  The belt 75 is wound around V grooves formed in the primary pulley 72 and the secondary pulley 77, respectively. The CVT 70 transmits power by using a frictional force between the inner wall portion of the V groove of the primary pulley 72 and the secondary pulley 77 and the belt 75. The CVT 70 is connected to the drive wheel 45.

  In this embodiment, as means for controlling the clamping force to the belt 75 from the primary pulley 72 and the secondary pulley 77, the oil pressure of the oil supplied to the pulleys 72 and 77 is controlled.

  The primary pulley 72 includes a movable sheave 72 a, a fixed sheave 72 b, and an input side hydraulic cylinder 73. The movable sheave 72a is provided so as to be rotatable integrally with the primary shaft 71 and movable in the axial direction. The fixed sheave 72b is provided so that it can rotate integrally with the primary shaft 71 and cannot move in the axial direction. The input side hydraulic cylinder 73 moves the movable sheave 72a in the axial direction by the primary sheave pressure Pin.

  The primary pulley 72 can change the V groove width between the primary pulley 72 and the fixed sheave 72 b by moving the movable sheave 72 a in the axial direction by the input side hydraulic cylinder 73. The primary pulley 72 changes the effective diameter, that is, the winding diameter of the belt 75 by changing the V groove width.

  The secondary pulley 77 includes a movable sheave 77 a, a fixed sheave 77 b, and an output side hydraulic cylinder 78. The movable sheave 77a is provided so as to be rotatable integrally with the secondary shaft 79 and movable in the axial direction. The fixed sheave 77b is provided so that it can rotate integrally with the secondary shaft 79 and cannot move in the axial direction. The output-side hydraulic cylinder 78 moves the movable sheave 77a in the axial direction by the belt clamping pressure Pd.

  The secondary pulley 77 can change the width of the V groove between the secondary pulley 77 and the fixed sheave 77 b by moving the movable sheave 77 a in the axial direction by the output-side hydraulic cylinder 78. The secondary pulley 77 changes the effective diameter, that is, the winding diameter of the belt 75 by changing the V groove width.

  The V-groove widths of the primary pulley 72 and the secondary pulley 77 are changed by the hydraulic pressure of oil supplied from the hydraulic control device 30 to the input-side hydraulic cylinder 73 and the output-side hydraulic cylinder 78, and the winding diameter of the transmission belt 75 is changed. Has been changed. The CVT 70 can change the actual gear ratio steplessly by controlling the thrust applied in the axial direction of the primary pulley 72 and the secondary pulley 77.

  In the CVT 70 of the present embodiment, the primary sheave pressure Pin of the input side hydraulic cylinder 73 is controlled by the hydraulic control circuit 31, whereby the V groove width of the primary pulley 72 is changed and the winding diameter of the belt 75 is changed. The Thereby, ECU 100 can continuously change the transmission gear ratio γ of CVT 70 (= the rotational speed Nin of primary shaft 71 / the rotational speed Nout of secondary shaft 79).

  Further, in the CVT 70 of the present embodiment, the belt clamping pressure Pd of the output side hydraulic cylinder 78 is controlled by the hydraulic control circuit 31, so that the belt clamping pressure from the secondary pulley 77 is prevented from causing the belt 75 to slip. Be controlled.

  The CVT 70 according to the present embodiment includes a primary pulley 72 that transmits rotational power from the engine 11 and has a variable groove width, a secondary pulley 77 that transmits rotational power to the drive wheels 45 and has a variable groove width, and a primary pulley. 72 and a belt 75 wound around the secondary pulley 77. The CVT 70 changes the belt clamping pressure from the primary pulley 72 and the secondary pulley 77 to the belt 75 by supplying oil to at least one of the primary pulley 72 and the secondary pulley 77. Further, the CVT 70 continuously controls the speed ratio γ by changing the effective winding diameters of the primary pulley 72 and the secondary pulley 77.

  The CVT 70 can switch the shift range according to the driver's request. The shift range is switched by operating the shift position of the shift lever 21. The CVT 70 includes a P (parking) range, an N (neutral) range, a D (drive) range, an R (reverse) range, an M (manual) range (sequential range), and the like as shift ranges.

  The transmission 20 includes an input shaft rotational speed sensor 85, an output shaft rotational speed sensor 86, and a turbine torque sensor 87. The input shaft rotational speed sensor 85 detects the rotational speed Nin of the primary shaft 71, converts it into a signal, and inputs the signal to the ECU 100. The output shaft rotational speed sensor 86 detects the rotational speed Nout of the secondary shaft 79, converts it into a signal, and inputs the signal to the ECU 100. The turbine torque sensor 87 detects the torque of the turbine shaft 54, converts it into a signal, and inputs the signal to the ECU 100.

  Next, the configuration of the hydraulic control circuit 31 included in the hydraulic control device 30 will be described with reference to FIG.

  As shown in FIG. 3, the hydraulic control circuit 31 includes an oil supply unit 200, a line pressure regulating unit 300, a lockup clutch control unit 400, a forward clutch control unit 500 as a starting clutch control unit, and a sheave pressure. And a control unit 600. These are all controlled by the ECU 100.

  As shown in FIG. 4, the oil supply unit 200 includes an oil pump 210 and an oil pan 220. The oil pump 210 includes a two-port oil pump, and includes a main port 211 that can discharge high-pressure oil and a sub-port 212 that can discharge high-pressure oil or low-pressure oil.

  The line pressure regulating unit 300 includes a primary pressure regulating valve 310, a first linear solenoid valve 320, a secondary pressure regulating valve 330, and a second linear solenoid valve 340 as an adjustment valve.

  The primary pressure regulating valve 310 includes a spool valve 311 that is movable in the axial direction, and an elastic member 312 that is a compression coil spring that biases the spool valve 311 toward one side in the axial direction. The spool valve 311 has land portions 311a, 311b, and 311c.

  The primary pressure regulating valve 310 has input ports 313 and 314, drain ports 315 and 316, a feedback port 317, and a signal pressure port 318. By the operation of the spool valve 311, the opening between the input port 313 and the drain port 315 is controlled by the land portion 311b, and the opening between the input port 314 and the drain port 316 is adjusted by the land portion 311c. The

  The input port 313 communicates with the sub port 212 of the oil pump 210, and the input port 314 communicates with the main port 211 of the oil pump 210. The feedback port 317 is in communication with the main port 211 of the oil pump 210.

  In the primary pressure regulating valve 310, the urging force of the elastic member 312 and the urging force of the signal pressure port 318 due to the hydraulic pressure act on the land portion 311c in the same direction, that is, on the land portion 311a side. Further, the urging force by the hydraulic pressure of the feedback port 317 acts in the opposite direction to the urging force corresponding to the urging force of the elastic member 312 and the hydraulic pressure of the signal pressure port 318, that is, on the land portion 311c side. Thus, the primary pressure regulating valve 310 causes the spool valve 311 to move along the axis line based on the opposing force relationship between the urging force of the feedback port 317 due to the hydraulic pressure and the urging force of the elastic member 312 and the urging force of the signal pressure port 318. It is designed to move in the direction.

  In the primary pressure regulating valve 310, when the hydraulic pressure supplied from the main port 211 of the oil pump 210 increases, the hydraulic pressure acting on the feedback port 317 also increases, and the spool valve 311 moves in the direction of the land portion 311c. As a result, the oil supplied from the main port 211 passes through the drain port 316 and is supplied to the secondary pressure regulating valve 330.

  In addition, the ECU 100 sets the hydraulic pressure at which oil supplied from the main port 211 passes through the drain port 316 to the line pressure PL. Thus, the primary pressure regulating valve 310 regulates the hydraulic pressure supplied from the main port 211 to the line pressure PL.

  The first linear solenoid valve 320 regulates a source pressure (not shown) and supplies the signal pressure P1 to the signal pressure port 318 of the primary pressure regulating valve 310.

  The secondary pressure regulating valve 330 includes a spool valve 331 that is movable in the axial direction, and an elastic member 332 that is a compression coil spring that biases the spool valve 331 toward one side in the axial direction. The spool valve 331 has land portions 331a, 331b, and 331c.

  The secondary pressure regulating valve 330 has input ports 333 and 334, drain ports 335 and 336, a feedback port 337, and a signal pressure port 338. By the operation of the spool valve 331, the opening between the input port 333 and the drain port 335 is controlled by the land portion 331b, and the opening between the input port 334 and the drain port 336 is adjusted by the land portion 331c. The

  The input port 333 communicates with the drain port 315 of the primary pressure regulating valve 310, and the input port 334 communicates with the drain port 316 of the primary pressure regulating valve 310. The feedback port 337 is in communication with the drain port 316 of the primary pressure regulating valve 310.

  In the secondary pressure regulating valve 330, the urging force of the elastic member 332 and the urging force due to the hydraulic pressure of the signal pressure port 338 act in the same direction with respect to the land portion 331c, that is, on the land portion 331a side. Further, the urging force due to the hydraulic pressure of the feedback port 337 acts in the opposite direction to the urging force corresponding to the urging force of the elastic member 332 and the hydraulic pressure of the signal pressure port 338, that is, on the land portion 331c side. As a result, the secondary pressure regulating valve 330 moves the spool valve 331 along the axis line based on the opposing force relationship between the biasing force due to the hydraulic pressure of the feedback port 337, the biasing force of the elastic member 332, and the biasing force due to the hydraulic pressure of the signal pressure port 338. It is designed to move in the direction.

  In the secondary pressure regulating valve 330, as the hydraulic pressure supplied from the drain port 316 of the primary pressure regulating valve 310 increases, the hydraulic pressure acting on the feedback port 337 also increases, and the spool valve 331 moves in the direction of the land portion 331c. As a result, the oil supplied from the drain port 316 of the primary pressure regulating valve 310 passes through the drain port 336 of the secondary pressure regulating valve 330 and is supplied to the lockup clutch control unit 400.

  Further, the ECU 100 sets the oil pressure at which the oil of the line pressure PL supplied from the drain port 316 of the primary pressure regulating valve 310 passes through the drain port 336 of the secondary pressure regulating valve 330 to the secondary pressure Psec.

  The second linear solenoid valve 340 adjusts a source pressure (not shown) and supplies the adjustment pressure Pslu to the signal pressure port 338 of the secondary pressure adjustment valve 330. The hydraulic control circuit 31 can be switched to at least one of a state where the line pressure PL is larger than the secondary pressure Psec and a state where the set value of the line pressure PL is smaller than the secondary pressure Psec.

  The lockup clutch control unit 400 includes a lockup control valve 410 and a lockup switching valve 420. The lockup clutch control unit 400 supplies the lockup differential pressure ΔP and controls the lockup differential pressure ΔP with the adjustment pressure Pslu.

  The lockup control valve 410 is configured to supply the oil supplied from the secondary pressure regulating valve 330 to the lockup switching valve 420. The lockup control valve 410 has an input port 411, output ports 412 and 413, and a signal pressure port 414. The input port 411 is in communication with both drain ports 335 and 336 of the secondary pressure regulating valve 330. The signal pressure port 414 is supplied with the adjustment pressure Pslu from the second linear solenoid valve 340.

  The lock-up control valve 410 adjusts the secondary pressure Psec supplied to the input port 411 by axial movement of a spool valve (not shown) and outputs it from the output port 412, and the secondary pressure supplied to the input port 411. Psec can be switched to the engaged state in which the output port 413 is output. The spool valve moves when the second linear solenoid valve 340 inputs the adjustment pressure Pslu to the signal pressure port 414.

  The ECU 100 controls the engagement side oil pressure Pon and the disengagement side oil pressure Poff by controlling the adjustment pressure Pslu from the second linear solenoid valve 340, thereby controlling the lockup differential pressure ΔP. When the lock-up control valve 410 is in the released state, the ECU 100 controls the lock-up differential pressure ΔP to a negative pressure so that the lock-up clutch 53 is in the released state. When the lockup control valve 410 is in the engaged state, the ECU 100 controls the lockup differential pressure ΔP to the maximum positive pressure so that the lockup clutch 53 is engaged or the lockup differential pressure ΔP is locked. By controlling ΔP from 0 to less than the maximum positive pressure, the slip state is controlled by making the slip state.

  Here, the lock-up control valve 410 is in a released state when the adjustment pressure Pslu is lower than a set pressure greater than 0, and the lock-up clutch 53 is in a released state. That is, the lock-up control valve 410 is in a released state if the adjustment pressure Pslu is not lower than 0 but is lower than the set pressure. The lock-up control valve 410 is engaged when the adjustment pressure Pslu is larger than the set pressure, and the lock-up clutch 53 is switched between the slipping state and the engaging state.

  The set pressure is greater than 0 and at least does not generate the engagement force of the lockup clutch 53. Further, even when the engagement pressure is supplied to the lockup clutch 53 when the adjustment pressure Pslu is the set pressure, the set pressure is set so that the occurrence of shock is suppressed in the lockup clutch 53. Further, when the adjustment pressure Pslu is the set pressure, the set pressure is set so that the lockup clutch 53 and the forward clutch 64 can quickly shift to the engaged state by supplying the lockup clutch 53 with the engagement pressure. Has been.

  The set pressure is appropriately set depending on the configuration of each part of the lockup clutch 53 and the lockup clutch control unit 400. The ECU 100 stores a preset set pressure, for example, in a ROM. The set pressure can be set to 0.04 M when the maximum pressure of the adjustment pressure Pslu is 0.6 MPa, for example. Needless to say, these values are not limitative.

  The lockup switching valve 420 supplies oil supplied from the lockup switching valve 420 to the lockup clutch 53. The lockup switching valve 420 has input ports 421 and 422, output ports 423 and 424, and a signal pressure port 425. The input port 421 is in communication with the output port 412 of the lockup control valve 410, and the input port 422 is in communication with the output port 413 of the lockup control valve 410. The output port 423 is in communication with the release side oil passage 56 of the torque converter 50, and the output port 424 is in communication with the engagement side oil passage 58 of the torque converter 50. The signal pressure port 425 is supplied with a signal pressure P2 from a linear solenoid valve (not shown).

  The lockup switching valve 420 outputs the hydraulic pressure supplied to the input ports 421 and 422 from the output port 423 and the hydraulic pressure supplied to the input ports 421 and 422 when the spool valve (not shown) moves in the axial direction. The engagement state output from the port 424 can be switched. The spool valve moves when a linear solenoid valve (not shown) inputs the signal pressure P2 to the signal pressure port 425. The ECU 100 controls the signal pressure P2 from the linear solenoid valve, so that the lockup switching valve 420 can switch the lockup clutch 53 between the engaged state and the released state.

  The forward clutch control unit 500 includes a garage switching valve 510. The forward clutch control unit 500 supplies the starting clutch pressure Pc and controls the starting clutch pressure Pc by the adjustment pressure Pslu.

  The garage switching valve 510 supplies the oil supplied from the second linear solenoid valve 340 to the forward clutch 64. The garage switching valve 510 has an input port 511, an output port 512, and a signal pressure port 513. The input port 511 is in communication with the second linear solenoid valve 340. The output port 512 is in communication with the forward clutch 64. The signal pressure port 513 is supplied with a signal pressure P3 from a linear solenoid valve (not shown).

  The garage switching valve 510 can be switched between an operating state in which the input port 511 communicates with the output port 512 and a released state in which both ports are disconnected by axial movement of a spool valve (not shown). The spool valve moves when a linear solenoid valve (not shown) inputs the signal pressure P3 to the signal pressure port 513.

  Thus, the ECU 100 can output the starting clutch pressure Pc from the output port 512 by controlling the signal pressure P3 from the linear solenoid valve. The ECU 100 can switch the forward clutch 64 between the engaged state and the released state by controlling the starting clutch pressure Pc supplied from the garage switching valve 510.

  The forward clutch control unit 500 includes a clutch apply control valve (not shown). The clutch apply control valve adjusts the hydraulic pressure of the oil supplied to the forward clutch 64 from the adjustment pressure Pslu supplied from the second linear solenoid valve 340 or the pressure regulating valve (not shown) according to the output state of the linear solenoid valve (not shown). Switching to one of the supplied Plpms is made.

  The sheave pressure control unit 600 has a known or new configuration, and supplies the primary sheave pressure Pin to the input side hydraulic cylinder 73 of the primary pulley 72 according to an instruction from the ECU 100, using the line pressure PL as a source pressure, and also uses a secondary pulley. The belt clamping pressure Pd is supplied to 77 output side hydraulic cylinders 78.

  The control apparatus for an automatic transmission according to the present embodiment includes a torque converter 50 and a CVT 70, and can execute garage control for switching the forward clutch 64 from a released state to an engaged state when the vehicle 10 is stopped. The flex start control for making the lock-up clutch 53 in the sliding state at the time of starting 10 can be executed. In addition, the control device for the automatic transmission according to the present embodiment includes a second linear solenoid valve 340 that adjusts the lockup differential pressure ΔP and the starting clutch pressure Pc.

  In the automatic transmission control apparatus according to the present embodiment, the adjustment pressure Pslu of the second linear solenoid valve 340 is larger than 0 so that the lockup clutch 53 is in a released state at the time of transition from garage control to flex start control. After the pressure is lowered to the set pressure, the adjustment pressure Pslu is raised to bring the lock-up clutch 53 into a sliding state.

  Next, the operation will be described.

  The ECU 100 executes processing of the following automatic transmission control program at predetermined time intervals of, for example, 10 ms. Here, a case where the driver operates the shift lever 21 while the vehicle 10 while the engine 11 is operating, switches the shift position from the P position to the D position, and the ECU 100 executes the garage control program. explain.

  As shown in FIG. 5, the ECU 100 determines whether or not a condition for ending the garage control program is satisfied (step S1). Whether the condition for ending the garage control program is satisfied is determined by the ECU 100 based on, for example, whether a predetermined time has elapsed after the forward clutch 64 is switched to the engaged state. When ECU 100 determines that the condition for terminating the garage control program is not satisfied (step S1; NO), ECU 100 returns the process to the main routine.

  When ECU 100 determines that the condition for terminating the garage control program is satisfied (step S1; YES), ECU 100 turns off the SC output and stops garage control (step S2). Then, the ECU 100 switches the clutch apply control valve so that the hydraulic pressure supplied to the forward clutch 64 is changed from the adjustment pressure Pslu so far to Plpm supplied from a pressure regulating valve (not shown) (step S3).

  The ECU 100 turns off the SLU output after switching the clutch apply control valve (step S4). Thereby, the adjustment pressure Pslu from the second linear solenoid valve 340 gradually decreases (step S5). Here, even if the adjustment pressure Pslu decreases, Plpm is supplied to the forward clutch 64, so the forward clutch 64 is maintained in the engaged state.

  The ECU 100 determines whether or not the adjustment pressure Pslu is less than or equal to a release threshold value as the set pressure of the lockup clutch 53 (step S6). The adjustment pressure Pslu is calculated by the ECU 100 based on, for example, a map showing the relationship between the adjustment pressure Pslu and the secondary pressure Psec. When the ECU 100 determines that the adjustment pressure Pslu is not less than or equal to the release threshold (step S6; NO), the ECU 100 determines again whether or not the adjustment pressure Pslu is less than or equal to the release threshold of the lockup clutch 53 (step S6). ).

  When the ECU 100 determines that the adjustment pressure Pslu is equal to or less than the release threshold (step S6; YES), the ECU 100 turns on the SL output (step S7). Then, ECU 100 switches lockup switching valve 420 to the engaged state (step S8).

  Further, ECU 100 turns on the SLU output by fast fill control (step S9). Thereby, the flex start control is started, and the adjustment pressure Pslu is increased (step S10). Further, the engagement pressure of the lockup clutch 53 increases due to the increase of the adjustment pressure Pslu (step S11). Therefore, the ECU 100 can start the vehicle 10 with the lock-up clutch 53 in the sliding state while maintaining the forward clutch 64 in the engaged state.

  Next, in the vehicle 10 in which the shift position of the shift lever 21 is switched from the P position to the D position and the garage control is executed, the operation when shifting to the flex start control will be described with reference to the time chart shown in FIG. To do.

  As the garage control is executed by the ECU 100, the adjustment pressure Pslu rises to the complete engagement pressure Pslu1. Here, since the engine speed Ne is about the idling speed and the engine torque is small, the engagement pressure Pslu1 is suppressed to a hydraulic pressure that is slightly higher than that at which the forward clutch 64 is completely engaged in order to improve fuel efficiency. Yes.

Since the adjustment pressure Pslu is supplied to the forward clutch 64, the starting clutch pressure Pc becomes Pslu1. Therefore, the forward clutch 64 is completely engaged. ECU 100 determines that the condition for ending the garage control program at T ₀ is satisfied, turns off the SC output, and ends the garage control.

  Then, the ECU 100 switches the clutch apply control valve so that Plpm is supplied to the forward clutch 64. Here, since the engine torque is increased by the start of the subsequent flex start control, Plpm is set to a sufficiently high hydraulic pressure, for example, about 1 to 1.2 MPa in order to increase the engagement force in the forward clutch 64. As a result, the starting clutch pressure Pc becomes Plpm, and the fully engaged state of the forward clutch 64 is maintained.

ECU100, in _{T 1} of the after switching clutch apply control valve turns off the SLU output. When the ECU 100 turns off the SLU output, the adjustment pressure Pslu from the second linear solenoid valve 340 gradually decreases. That is, before turning off the SLU output and reducing the adjustment pressure Pslu, the ECU 100 switches the clutch apply control valve to maintain the engaged state of the forward clutch 64 by Psml.

ECU100, in _{T 2} for adjusting pressure Pslu reaches a release threshold, to turn on the SL output. Then, ECU 100 switches lockup switching valve 420 to the engaged state. Moreover, ECU 100 is in _{T 3} after switching the lockup switching valve 420 into engagement, to turn the fast fill control SLU output. As a result, the flex start control is started and the adjustment pressure Pslu increases.

  Further, the engagement pressure of the lockup clutch 53 increases due to the increase of the adjustment pressure Pslu. Therefore, the ECU 100 can start the vehicle 10 with the lock-up clutch 53 in the sliding state while maintaining the forward clutch 64 in the engaged state.

  Here, a comparative example in which the flex start control is started after the adjustment pressure Pslu has decreased to 0 MPa as in the prior art will be described.

In this case, as indicated by a one-dot chain line in FIG. 6, the ECU 100 turns on the SL output at T ₃ when the adjustment pressure Pslu reaches 0 MPa. Then, ECU 100 switches lockup switching valve 420 to the engaged state. Further, ECU 100, in _{T 4} after switching the lockup switching valve 420 into engagement, to turn the fast fill control SLU output. Thereby, the flex start control is started.

  The time from the end of the garage control to the start of the flex start control is only the time A in the present embodiment, while the comparative example requires a longer time B. Therefore, the ECU 100 according to the present embodiment can shorten the time from the end of the garage control to the start of the flex start control as compared with the conventional case.

  As described above, according to the control device for an automatic transmission according to the present embodiment, the ECU 100 locks up by controlling the second linear solenoid valve 340 during the transition from the garage control to the flex start control. The adjustment pressure Pslu is reduced to a release threshold value at which the clutch 53 is released. That is, the control device for the automatic transmission can bring the lock-up clutch 53 into the released state without reducing the adjustment pressure Pslu to 0 MPa. Then, after the lock-up clutch 53 is released, the ECU 100 raises the adjustment pressure Pslu to bring the lock-up clutch 53 into a sliding state and starts flex start control.

  As a result, the ECU 100 adjusts after the end of the garage control, as compared with the conventional case where the flex start control is started by lowering the adjustment pressure Pslu to 0 MPa after the end of the garage control and then increasing the adjustment pressure Pslu again. The time until the pressure Pslu is increased again can be shortened. Therefore, the ECU 100 can start the flex start control earlier than the conventional one after the garage control. In addition, since the ECU 100 performs the flex start control after the lockup clutch 53 is released after the garage control is completed, the occurrence of the engagement shock of the lockup clutch 53 can be suppressed.

  For this reason, according to the automatic transmission control device of the present embodiment, the transition from the garage control to the flex-start control can be realized more quickly than before, and a smooth transition that suppresses the occurrence of shock can be realized. it can. Therefore, according to the automatic transmission control device of the present embodiment, it is possible to achieve both improvement in fuel efficiency and improvement in drivability in the transition from garage control to flex start control.

  Further, according to the automatic transmission control device according to the present embodiment, the release threshold is at least a pressure at which the engagement force of the lock-up clutch 53 is not generated, so that the lock-up clutch 53 is The state is shifted from the state where there is no engagement force to the slip state, and the occurrence of shock can be suppressed.

  Further, according to the automatic transmission control apparatus according to the present embodiment, ECU 100 can control lockup differential pressure ΔP by controlling adjustment pressure Pslu supplied to lockup clutch control unit 400, and forward clutch. The starting clutch pressure Pc can be controlled by controlling the adjustment pressure Pslu supplied to the controller 500. For this reason, the second linear solenoid valve 340 is shared by the lockup clutch control unit 400 and the forward clutch control unit 500, and the engagement and release of the lockup clutch 53 and the forward clutch 64 are executed by simple control. Can do.

  In the above-described automatic transmission control apparatus according to the present embodiment, the case where the shift position is switched from the P position to the D position has been described as an example of garage control. However, the control apparatus for an automatic transmission according to the present invention is not limited to this. For example, when the shift position is switched from the N position to the D position, or when the P position or the N position is switched to the R position. Can also be included.

  In the automatic transmission control device according to the present embodiment, the operation when ECU 100 shifts from the garage control to the flex start control has been described. However, the control apparatus for an automatic transmission according to the present invention is not limited to this. For example, it may be a case where a transition is made from N control to flex start control, or a case where garage control is shifted to lockup control. Good.

  In the automatic transmission control apparatus according to the present embodiment, the case where the automatic transmission mechanism is applied to the CVT 70 has been described. However, the control apparatus for an automatic transmission according to the present invention is not limited to this, and may be applied to a stepped transmission using a plurality of clutches, brakes, and gears. In this case, as the starting clutch, it is preferable to use a clutch closest to the engine 11 provided in the stepped transmission, such as a C1 clutch.

  As described above, the control device for an automatic transmission according to the present invention has an effect of achieving both improvement in fuel efficiency and drivability in a transition from garage control to flex start control in a vehicle equipped with an automatic transmission. Yes, it is useful for automatic transmission control devices.

10 Vehicle 11 Engine (drive source)
20 Transmission (automatic transmission)
45 Driving wheel 50 Torque converter (fluid transmission mechanism)
50a Input shaft 53 of fluid transmission mechanism 53 Lock-up clutch 54 Turbine shaft (output shaft of fluid transmission mechanism)
60 Forward / reverse switching machine 64 Forward clutch (start clutch)
70 CVT (automatic transmission mechanism, continuously variable transmission)
70a Input shaft 79 of automatic transmission mechanism Secondary shaft (output shaft of automatic transmission mechanism)
100 ECU (automatic transmission control device)
400 Lock-up clutch control unit 500 Forward clutch control unit (starting clutch control unit)
Pc Starting clutch pressure Pslu Adjusting pressure Pon Engagement side hydraulic pressure Poff Release side hydraulic pressure ΔP Lock-up differential pressure (differential pressure)

Claims (5)

In a control device for an automatic transmission, comprising: a fluid transmission mechanism coupled to a drive source of a vehicle; and an automatic transmission mechanism coupled to the fluid transmission mechanism and a drive wheel.
The fluid transmission mechanism includes: an input shaft coupled to the drive source; an output shaft coupled to the automatic transmission mechanism; an engagement state in which the input shaft and the output shaft are engaged; the input shaft and the input shaft; A lock-up clutch that switches a transmission state between a release state that releases an output shaft and a slip state that slips the input shaft and the output shaft at a predetermined slip ratio;
The automatic transmission mechanism includes an input shaft coupled to the fluid transmission mechanism, an output shaft coupled to the drive wheel, an input shaft coupled to the fluid transmission mechanism, and an output shaft coupled to the drive wheel. A starting clutch that switches a transmission state between an engagement state that engages between the fluid transmission mechanism and a release state that releases between an input shaft coupled to the fluid transmission mechanism and an output shaft coupled to the drive wheel, Have
The lockup clutch is controlled by the differential pressure between the engagement side hydraulic pressure and the release side hydraulic pressure, and the start clutch is controlled by the start clutch pressure of the supplied oil.
It is possible to execute garage control for switching the starting clutch from the released state to the engaged state when the vehicle is stopped, and to execute flex start control for bringing the lock-up clutch into the sliding state when the vehicle is started. A control device for an automatic transmission,
An adjustment valve for adjusting the differential pressure and the starting clutch pressure;
At the time of transition from the garage control to the flex start control, the adjustment pressure of the adjustment valve is reduced to a set pressure greater than 0 so that the lockup clutch is in the released state, and then the adjustment pressure is increased. A control device for an automatic transmission, wherein the lock-up clutch is brought into the sliding state.   2. The control device for an automatic transmission according to claim 1, wherein the set pressure is a pressure that does not generate at least an engagement force of the lockup clutch. A lock-up clutch control unit that supplies the differential pressure and controls the differential pressure by the adjustment pressure;
3. A control device for an automatic transmission according to claim 1, further comprising: a starting clutch control unit that supplies the starting clutch pressure and controls the starting clutch pressure by the adjustment pressure. 4. . The automatic transmission mechanism is a continuously variable transmission having a forward / reverse switching machine,
The automatic transmission control device according to any one of claims 1 to 3, wherein the starting clutch is a forward clutch provided in the forward / reverse switching device. The automatic transmission mechanism is a stepped transmission having a plurality of clutches and brakes,
The control device for an automatic transmission according to any one of claims 1 to 3, wherein the starting clutch is a clutch closest to the drive source included in the stepped transmission.

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