JP2023118403A - Control device of automatic transmission - Google Patents

Abstract

To improve the transmission responsiveness of a drive force, and to avoid an unintentional stop of an engine, in a situation that the viscosity of a working fluid for operating an automatic gear change becomes high, and the followability of actual pressure with respect to an indication value of hydraulic pressure is deteriorated.SOLUTION: A control device of an automatic transmission is arranged in a drive force transmission path for transmitting the power of an engine to wheels, and forms a prescribed gear change stage by changing an engagement state of a friction engagement element. The control device comprises: a traveling range standby control part for making a part of a traveling range forming element which forms a traveling range engaged before being switched to the traveling range out of the friction engagement element; and a working fluid state determination part for determining whether or not the viscosity of a working fluid for operating the friction engagement element is in a response delay state that a response delay with respect to an indication value of hydraulic pressure occurs. When the response delay state is determined, the traveling range standby control part raises an indication value of hydraulic pressure for making a brake element engaged from hydraulic pressure at which a release state of the brake element is maintained after an oil temperature of the working fluid reaches a threshold or higher.SELECTED DRAWING: Figure 5

Description

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

2. Description of the Related Art Conventionally, an automatic transmission is known that is arranged in a driving force transmission path for transmitting the output of an engine as a power source to the wheels of a vehicle. The automatic transmission is arranged downstream of the engine along the driving force transmission direction in the driving force transmission path. An automatic transmission changes the combination of engagement states of multiple frictional engagement elements to switch between a non-driving range such as a parking (P) range and a neutral (N) range and a driving range in which forward and reverse travel is possible. Switching is performed, and an arbitrary gear stage is realized.

A friction engagement element in an automatic transmission is operated by hydraulic oil (ATF: Automatic Transmission Fluid), and is brought into a desired engagement state by controlling the oil pressure. The automatic transmission engages a part of the plurality of frictional engagement element devices that are brought into an engaged state in order to realize the driving range prior to the timing at which an operation to shift to the driving range is performed. (See Patent Document 1, for example). The automatic transmission includes a brake element as a frictional engagement element, and the brake element and the clutch element correspond to some of the frictional engagement elements that are engaged to realize the driving range. There is These brake elements and clutch elements may be engaged prior to the timing of switching to the driving range. As a result, when the driver performs an operation to select the driving range, the automatic transmission can be quickly switched to the driving range with good responsiveness, and the responsiveness of transmission of driving force can be improved.

JP 2012-17822 A

By the way, depending on the environment in which the vehicle is placed, the viscosity of the hydraulic oil for controlling the automatic transmission may become high, and the followability of the actual pressure to the indicated value of the hydraulic pressure may deteriorate. When the brake element and the clutch element are to be engaged, these elements can be smoothly engaged by gradually increasing the indicated value of the hydraulic pressure. However, in a situation where the followability of the actual pressure to the indicated value of the hydraulic pressure deteriorates, it is assumed that the braking element or the like is suddenly engaged at an unintended timing.

Here, some of the elements included in the automatic transmission are linked with the engine output shaft extending from the engine, and depending on their characteristics, they affect the elements linked with the engine output shaft even in the non-driving range. Sometimes. Therefore, when the frictional engagement element such as the brake element is suddenly engaged at an unintended timing, the influence of the frictional engagement element affects the elements interlocking with the engine output shaft, which may cause the engine to stop.

Patent Document 1 does not consider any countermeasures against such a phenomenon.

Therefore, the present invention improves the responsiveness of transmission of driving force in a situation where the viscosity of the hydraulic oil that activates the automatic shift increases and the followability of the actual pressure to the indicated value of the hydraulic pressure deteriorates, and unintentionally The purpose is to prevent the engine from stalling.

The above object is an automatic transmission that is arranged in a driving force transmission path that transmits the power of an engine, which is a driving source, to wheels, and that changes the engagement state of a plurality of frictional engagement elements to form a desired gear stage. wherein the driving range standby control performs driving range standby control in which some of the driving range forming elements forming the driving range are engaged before switching to the driving range among the plurality of friction engagement elements. and a hydraulic oil state for determining whether or not the viscosity of the hydraulic oil that operates the frictional engagement element is in a response delay state that causes a delay in response to the indicated value of the hydraulic pressure when the travel range standby control is started. a determination unit, wherein the running range standby control unit determines that the viscosity of the hydraulic oil is in a delayed response state, and the oil temperature of the hydraulic oil is equal to or higher than a predetermined threshold value. This is achieved by a control device for an automatic transmission that raises a command value of hydraulic pressure for engaging a braking element included in the driving range forming element later from a hydraulic pressure that maintains the disengaged state of the braking element.

In the automatic transmission control device described above, the travel range standby control unit determines that the oil temperature of the hydraulic oil is equal to or higher than a predetermined threshold value when it is determined that the viscosity of the hydraulic oil is in a delayed response state. In addition, after a predetermined waiting period for waiting with the indicated value of the hydraulic oil pressure as the state before the start of engagement, the indicated value of the hydraulic pressure for engaging the brake element included in the travel range forming element is set. It can be set as the aspect raised.

Further, in the automatic transmission control device described above, the standby period set when it is determined that the response is delayed is such that the viscosity of the hydraulic oil when the traveling range standby control is started is equal to the indicated value of the hydraulic pressure. A mode longer than the waiting period set when in the following response tracking state can be employed.

The invention disclosed in the present specification improves the responsiveness of transmission of driving force in a situation where the viscosity of the hydraulic oil that activates the automatic shift increases and the followability of the actual pressure to the indicated value of the hydraulic pressure deteriorates. It is possible to avoid stopping the engine without

FIG. 1 is a schematic diagram that schematically illustrates an example of the configuration of a hybrid vehicle that includes a control device for an automatic transmission according to an embodiment. FIG. 2(A) is a schematic diagram showing an example of an automatic transmission, and FIG. 2(B) is a schematic diagram showing elements that cause rotation speed fluctuations due to engagement of a brake B2 in an automatic transmission. (C) is a skeletal diagram showing elements that cause an inertia change due to engagement of a brake B2 in the automatic transmission. FIG. 3 is a diagram showing the relationship between the gear stage realized by the automatic transmission shown in FIG. 2 and the disengaged state of the frictional engagement elements. FIG. 4 is a flowchart showing an example of control executed by the automatic transmission control device of the embodiment. FIG. 5 is an example of a time chart showing changes in each value associated with control executed by the control device for an automatic transmission according to the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, in the drawings, the dimensions, ratios, etc. of each part may not be illustrated so as to completely match the actual ones. In some drawings, details may be omitted.

(embodiment)
[Vehicle configuration]
FIG. 1 is a schematic configuration diagram of a hybrid vehicle (hereinafter simply referred to as "vehicle") 1 to which the present invention is applied. The vehicle 1 includes a driving force transmission path 10 from an engine 12 to wheels 24 and an ECU (Electronic Control Unit) 100 that performs various controls of the vehicle 1 . The ECU 100 functions as a control device for the automatic transmission 17, as will be detailed later.

In the driving force transmission path 10, a K0 clutch 13, a motor generator (MG) 14, a torque converter 15, a motor generator (MG) 14, a torque converter 15, a K0 clutch 13, a motor generator (MG) 14, and a An oil pump 16 and an automatic transmission (A/T) 17 are provided. The driving force transmission path includes a propeller shaft 19 connected to the output shaft 18 of the automatic transmission 17, a differential gear device 20 connected to the propeller shaft 19, and an axle connected to the differential gear device 20. 21. Axles 21 are provided on both sides of the differential gear device 20, and wheels 24 are mounted respectively.

When the K0 clutch 13 is engaged, the power of the engine 12 is supplied from the engine output shaft 22 connecting the engine 12 and the K0 clutch 13 to the K0 clutch 13, the torque converter 15, the transmission input shaft 23 and the automatic transmission. 17. The power of the engine 12 is transmitted from the automatic transmission 17 to the wheels 24 through the propeller shaft 19 , the differential gear device 20 and the axles 21 in sequence.

The torque converter 15 is a hydrodynamic transmission device, and transmits the driving force input to the pump impeller 15a to the automatic transmission 17 side via fluid. The pump impeller 15a is an input-side rotating element that inputs the driving force of the engine 12 to the torque converter 15, and is connected to the engine 12 via the K0 clutch 13 and the engine output shaft 22 in sequence. The turbine wheel 15b of the torque converter 15 is an output-side rotating element of the torque converter 15, and is connected to the transmission input shaft 23, which is an input rotating member of the automatic transmission 17, by spline fitting or the like so as not to rotate relative to each other. . The torque converter 15 has a lockup clutch 26 . The lockup clutch 26 is a direct coupling clutch provided between the pump impeller 15a and the turbine impeller 15b, and is brought into an engaged state, a slip state and a released state by hydraulic control.

The motor generator 14 is an example of an electric motor, and has a function as a motor that generates mechanical driving force from electrical energy and a function as a generator that generates electrical energy from mechanical energy. The motor generator 14 can be used as a driving force source for driving instead of the engine 12 or for generating driving force for driving together with the engine 12 . In addition, the motor generator 14 regenerates electric energy from the driving force generated by the engine 12 and the driven force (mechanical energy) input from the wheel 24 side, and transmits the electric energy through the inverter 60. can be accumulated in the power storage device 61 . The motor generator 14 is connected to the pump impeller 15a, and power is mutually transmitted between the electric motor MG and the pump impeller 15a. Thus, like the engine 12, the motor generator 14 is connected to the transmission input shaft 23 so as to be able to transmit power.

The oil pump 16 is a mechanical pump connected to the pump impeller 15a, and controls the torque capacity of the lockup clutch 26, engages and disengages the K0 clutch 13, and supplies lubricating oil to each part of the driving force transmission path 10. Hydraulic pressure is generated for The vehicle 1 has an electric oil pump 51 in addition to the mechanical oil pump 16 . The electric oil pump 51 can obtain working oil pressure in a situation where it is difficult to obtain working oil pressure from the oil pump 16 .

The K0 clutch 13 is a wet multi-plate hydraulic friction engagement element in which a plurality of friction plates arranged in an overlapping manner are pressed by a hydraulic actuator. The K0 clutch 13 is controlled to be engaged and released by a hydraulic control circuit 50 provided with hydraulic pressure generated by the oil pump 16 as a source pressure. The K0 clutch 13 includes a pair of clutch rotating members, that is, a clutch hub and a clutch drum, which are relatively rotatable in a released state, and one of the clutch rotating members (clutch hub) is connected to the engine output shaft 22 so as not to rotate relative to each other. It is On the other hand, the other clutch rotating member (clutch drum) is connected to the pump impeller 15a of the torque converter 15 so as not to rotate relative thereto. As a result, the K0 clutch 13 rotates the pump impeller 15a integrally with the engine 12 via the engine output shaft 22 in the engaged state. On the other hand, the K0 clutch 13 blocks power transmission between the pump impeller 15a and the engine 12 in its disengaged state. Further, the K0 clutch 13 connects and disconnects the driving force transmission path 10 between the engine 12 and the motor generator 14 .

The automatic transmission 17 is arranged closer to the wheels 24 than the motor generator 14 in the driving force transmission path 10 . A K0 clutch 13 is arranged between the engine 12 and the motor generator 14. When the K0 clutch 13 is engaged, the automatic transmission 17 is connected to the engine 12 and the driving force of the engine 12 is generated. is transmitted.

The automatic transmission 17 can form a desired shift speed by changing the engagement state of a plurality of frictional engagement elements. The frictional engagement elements in the automatic transmission 17 are, for example, hydraulically operated clutches and brakes. is selectively established. The automatic transmission 17 of this embodiment is a planetary gear type multi-speed transmission. The automatic transmission 17 is a stepped transmission that performs a so-called clutch-to-clutch shift that is often used in known vehicles. The transmission input shaft 23 is a turbine shaft driven to rotate by the turbine wheel 15 b of the torque converter 15 . In the automatic transmission 17, a predetermined gear stage is established according to the driver's accelerator operation, the vehicle speed V, and the like, by controlling the engagement of the clutch and the brake.

[Driving range forming element]
FIG. 2A shows the configuration of the automatic transmission 17. As shown in FIG. The automatic transmission 17 changes the speed of the rotation of a transmission input shaft 23 connected to the turbine shaft of the torque converter 15 (see FIG. 1) in multiple steps and outputs it from the output shaft 18 . The automatic transmission 17 includes a single pinion first planetary gear device 52, a double pinion second planetary gear device 54, a single pinion third planetary gear device 56, and a single pinion fourth planetary gear device 58. Prepare. The first planetary gear device 52 and the second planetary gear device 54 constitute a so-called Ravigneaux type planetary gear train. The automatic transmission 17 also comprises four clutches C1-C4 and two brakes B1, B2.

Referring now to FIG. 3, there are shown combinations of gear stages realized in the automatic transmission 17 and engagement states of the respective frictional engagement elements. The automatic transmission 17 has 10 forward gear stages (first gear stage " 1st” to 10th gear “10th”). The transmission input rotation speed NIN is the rotation speed of the transmission input shaft 23, the output shaft rotation speed NOUT is the rotation speed of the output shaft 18, and the output shaft rotation speed NOUT corresponds to the vehicle speed V. FIG. The automatic transmission 17 can also select the reverse gear "R".

When the vehicle 1 starts running, the 1st gear stage is normally selected. According to FIG. 3, in the 1st gear stage, the clutch C1, the clutch C2 and the brake B2 are engaged. is realized by Further, the reverse gear stage R for moving the vehicle 1 backward is realized by engaging the clutch C1, the clutch C3, and the brake B2. Therefore, in this specification, the clutch C1, the clutch C2, and the brake B2 are elements that form the running range during forward travel. In addition, the clutch C1, the clutch C3 and the brake B2 are elements for forming a running range during reverse travel. These clutches and brakes are subjected to engagement control by changing the torque capacity, that is, the engagement force, by adjusting the pressure of a linear solenoid valve or the like in the hydraulic control circuit 50 .

Here, the properties of the brake B2 will be described with reference to FIGS. 2(B) and 2(C). In FIG. 2(B), the elements shown in bold lines are the elements that cause rotation speed fluctuations due to changes in the engagement state of the brake B2, and the elements shown in thick lines in FIG. It is an element that causes an inertia change due to a change in the engagement state of the brake B2. In FIG. 2(C), the element indicated by the thick line includes the transmission input shaft 23. Therefore, when the transmission input shaft 23 is connected to the engine output shaft 22, the inertia change is It is assumed that the engine 12 is affected. Therefore, depending on how the brake B2 is engaged, the engine 12 may be affected by the change in inertia, and as a result, the engine 12 may stop, ie, the engine may stall.

[Control device for automatic transmission]
Returning to FIG. 1, the ECU 100 included in the vehicle 1 will be described. The ECU 100 includes a so-called microcomputer having a CPU, RAM, ROM, input/output interfaces, and the like. The CPU executes various controls of the vehicle 1 by performing signal processing according to programs stored in advance in the ROM while using the temporary storage function of the RAM. The ECU 100 executes, for example, output control of the engine 12, drive control and regeneration control of the motor generator 14, shift control of the automatic transmission 17, torque capacity control of the lockup clutch 26, torque capacity control of the K0 clutch 13, and the like. The ECU 100 is configured separately for engine control, electric motor control, hydraulic control (for transmission control), etc., as required, and functions as a control device for the automatic transmission 17 in this embodiment. In the following description, the function of the automatic transmission 17 as a control device will be mainly described.

The ECU 100 includes a shift position determination section 101, a travel range standby control section 102, and a hydraulic oil state determination section 103, as shown in functional blocks in FIG.

A shift position determination unit 101 determines a shift position of a shift lever 64 such as "P", "N", "D", "R", and "S" positions detected by a shift position sensor 63 provided in the vehicle 1. .

Driving range standby control unit 102 performs driving range standby control that engages some of the driving range forming elements described above before switching to the driving range. Specifically, the driving range standby control is a state in which the shift position is in the non-driving range of "P" or "N" and the automatic transmission 17 is engaged to realize the driving range of 1st or R. This control keeps the clutch C2 and the brake B2 engaged. By engaging the clutch C2 and the brake B2 in the non-driving range, for example, if the clutch C1 is engaged when the "D" position is set after that, all the driving range forming elements for moving forward are engaged. In this state, the vehicle 1 can immediately move forward. Further, by engaging the clutch C2 and the brake B2 in the non-running range, for example, if the clutch C3 is engaged when the "R" position is set after that, all the elements for forming the running range for moving backward can be obtained. is engaged, and the vehicle 1 can immediately move backward.

Hydraulic oil condition determination unit 103 determines whether the viscosity of hydraulic oil for operating automatic transmission 17 is hydraulic based on the value of the outside air temperature measured by outside air temperature sensor 53 and the value of the oil temperature measured by oil temperature sensor 50a. It is determined whether it is in a response delay state in which a response delay occurs with respect to the indicated value of , or in a response follow-up state in which the indicated value of hydraulic pressure is followed. When the temperature of the hydraulic oil decreases due to the temperature of the environment in which the vehicle 1 is placed and the viscosity of the hydraulic oil increases, the fluidity of the hydraulic oil decreases and a delay in response to the indicated value of the hydraulic pressure occurs. Become.

If the driving range standby control unit 102 executes the driving range standby control and outputs an instruction value for the hydraulic pressure for engaging the brake B2 when the viscosity of the hydraulic oil is in a delayed response state, the actual hydraulic pressure It is assumed that the rise of the oil pressure is delayed with respect to the indicated value of the hydraulic pressure. Therefore, the driving range standby control unit 102 changes the content of the driving range standby control in consideration of the determination result of the hydraulic oil state determination unit 103 . The driving range standby control will be described below with reference to FIGS. 4 and 5. FIG.

[Driving range standby control]
Referring to the time chart shown in FIG. 5, it is assumed that a starter drive command for starting the engine 12 is issued at time t1. In the time period shown in the time chart shown in FIG. 5, the shift position is in the non-running range of "P" or "N." The ECU 100 starts running range standby control at the timing when the starter drive instruction is issued. The engine 12 starts rotating by cranking at time t1, and increases the rotation speed from time t2 to time t3 toward complete explosion. After time t4, the idling speed is maintained. Further, the ECU 100 issues an engagement instruction to the K0 clutch 13 at time t3. The rotation speed of the motor generator 14 starts increasing from time t3, and coincides with the engine rotation speed at time t4.

In step S1, the ECU 100 determines whether or not the engine 12 is started at extremely low temperatures. Here, starting at extremely low temperatures means that the vehicle 1 is started under an environment in which the hydraulic oil of the automatic transmission 17 is delayed in response. When the measured outside temperature is equal to or lower than a preset outside temperature threshold value, it is determined that the engine has been started at extremely low temperatures. The outside air temperature threshold is set based on the outside air temperature at which the hydraulic fluid causes a delay in response, which is determined in advance by simulation or adaptation using an actual machine. In step S1, it may be determined whether or not the engine is to be started at extremely low temperatures based on the oil temperature of the hydraulic oil, instead of determining whether the engine is to be started at extremely low temperatures based on the outside air temperature.

When the ECU 100 makes an affirmative determination (Yes determination) in step S1, the process proceeds to step S2. In step S2, the ECU 00 selects cryogenic standby control. On the other hand, when the ECU 100 makes a negative determination (No determination) in step S1, the process proceeds to step S3. The ECU 100 selects normal standby control in step S3.

Here, referring to FIG. 5 again, the ECU 100 issues an instruction to drive the electric oil pump (EOP) 51 at time t3 when the instruction to drive the starter ends. The reason why the instruction to drive the electric oil pump 51 is issued after the instruction to drive the starter is completed is that both the driving of the starter and the driving of the electric oil pump 51 involve power consumption, so they must be driven at the same timing. This is to avoid The period during which the instruction to drive the electric oil pump 51 is issued is from time t3 to time t5. This is because the engagement oil pressure instruction for brake B2 is issued at time t4. At time t4, the engine 12 starts operating, but there is a time lag before the mechanical oil pump 16 (see FIG. 1) operates and oil is discharged. Therefore, the electric oil pump 51 is operated from time t3 to time t4.

In the extremely low temperature standby control selected in step S2, the ECU 100 waits until a predetermined standby period elapses before the command value of the hydraulic pressure for engaging the brake B2 increases. In this embodiment, the period from time t4 to time t8 is set as the standby period. This standby period is set in advance by simulation or adaptation using an actual machine as a period during which the response delay of the hydraulic oil is eliminated. Referring to FIG. 5, the indicated value of the hydraulic pressure from the time t4 to the time t5, which is the initial stage of the waiting period, is higher than the indicated value of the hydraulic pressure thereafter. This is because the hydraulic fluid is not flowing in the period up to time t4, so a higher command value is given so that the hydraulic fluid that is not flowing starts to flow. This indication value instruction is similarly carried out in normal standby control, which will be described later. The indicated value of the hydraulic pressure from the time t4 to the time t8 is the state before the engagement of the brake B2 is started. set to a value. Note that this state is sometimes referred to as a packed state.

In step S4 that follows step S2, the ECU 100 determines whether or not the waiting period has elapsed, that is, whether or not time t8 has elapsed. When the ECU 100 makes an affirmative determination in step S4, the process proceeds to step S5. On the other hand, when a negative determination is made in step S4, the ECU 100 repeats the process of step S4 until an affirmative determination is made in step S4.

In step S5, the ECU 100 determines whether or not the oil temperature of the hydraulic oil (ATF oil temperature) is equal to or higher than a predetermined threshold based on the detection value of the oil temperature sensor 50a. This threshold value is set in advance as an oil temperature at which the response delay of hydraulic oil does not occur. Referring to FIG. 5, at time t7, the temperature of the hydraulic oil is higher than the threshold. When the oil temperature of the hydraulic oil becomes higher than the threshold value in this manner, the ECU 100 makes an affirmative determination in step S5. When the ECU 100 makes an affirmative determination in step S5, the process proceeds to step S6. On the other hand, when a negative determination is made in step S5, the ECU 100 repeats the processing of step S5 until an affirmative determination is made in step S5. The oil temperature of the hydraulic oil in step S5 may be estimated using a value having a correlation with the oil temperature of the hydraulic oil. The oil temperature of the hydraulic oil is, for example, the outside air temperature, the oil temperature of the hydraulic oil when the engine 12 is in operation, the amount of heat accumulated in the flow path through which the hydraulic oil circulates, changes in the temperature of the cooling water circulating through the engine 12, and the like. It can be estimated by a conventionally known method such as using a value estimated based on.

In the example shown in FIG. 5, the oil temperature of the hydraulic oil exceeds the threshold at time t7, which is earlier than time t8. It may exceed. In addition, in the present embodiment, two determination items are set, ie, whether the oil temperature of the hydraulic oil exceeds the threshold value and whether or not the standby period has elapsed. It may be set. Moreover, step S4 and step S5 may be performed in the order of step S4 and step S5 regardless of the order, or may be performed at the same time.

In step S6, the ECU 100 gradually increases the indicated value of the hydraulic pressure for engaging the brake B2 in order to apply the brake B2. Specifically, the indicated value of the hydraulic pressure is gradually increased from time t8. At time t8, the delay in the response of the hydraulic oil is resolved, and the followability of the actual pressure to the indicated value is ensured, so the brake B2 is suddenly engaged at an unintended timing, and the engine 12 stops. is avoided.

On the other hand, even in the normal standby control selected in step S3, the ECU 100 waits until the predetermined standby period elapses before the command value of the oil pressure for engaging the brake B2 increases. When the normal standby control is performed, the viscosity of the hydraulic oil is in a response follow-up state in which it follows the indicated value of the hydraulic pressure. Therefore, the standby period in normal standby control is set to a period from time t4 to time t6, which is shorter than the standby period in standby control at extremely low temperatures. That is, in the cryogenic standby control, a longer standby period is set than in the normal standby control. Note that the period from time t4 to time t6 is set as a period during which packing can be started so that engagement of the brake B2 can be completed.

In step S7 that follows step S3, the ECU 100 determines whether or not the waiting period has elapsed, that is, whether or not time t7 has elapsed. When the ECU 100 makes an affirmative determination in step S7, the process proceeds to step S6. On the other hand, when a negative determination is made in step S7, the ECU 100 repeats the process of step S7 until an affirmative determination is made in step S7. Since the contents of the processing in step S6 are the same as those after step S5, the description thereof will be omitted here.

In step S6, the brake B2 is subsequently engaged by starting the engagement of the brake B2. Although not described here, the clutch C2 is also engaged. Due to its structure, the clutch C2 does not cause a change in inertia, and even if it suddenly becomes engaged, the engine 12 will not stop. Therefore, the clutch C2 can be brought into the engaged state without performing special control such as when engaging the brake B2.

In this embodiment, in the non-driving range, the automatic transmission 17 engages the clutch C2 and the brake B2, which are part of the driving range forming elements, before switching to the driving range. Then, when the shift position is subsequently changed to, for example, the "D" range, the automatic transmission 17 immediately engages the clutch C1 to realize the 1st gear stage and immediately bring the vehicle 1 into the running state. be able to. Further, when the shift position is changed to the "R" range, the automatic transmission 17 realizes the reverse gear R by connecting the clutch C3 to the bearing seat, so that the vehicle 1 can be immediately reversed. .

[effect]
In this embodiment, of the plurality of friction engagement elements provided in the automatic transmission 17, the clutch C2 and the brake B2, which are part of the driving range forming elements that form the driving range, are engaged before switching to the driving range. . Therefore, the responsiveness of transmission of driving force is high. Further, when the hydraulic oil that operates the brake B2 is in a response delay state, the indicated value of the oil pressure for engaging the brake B2 is increased after the oil temperature of the hydraulic oil becomes equal to or higher than the threshold value. As a result, it is avoided that the brake B2 is suddenly engaged and the engine 12 is stopped.

The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited to these. Various modifications of these examples are within the scope of the present invention, and furthermore, the present invention can be modified. It is self-evident from the above description that many other embodiments are possible within the scope.

1 hybrid vehicle (vehicle) 10 driving force transmission path 11 transmission case 12 engine 13 K0 clutch 14 motor generator 15 torque converter 17 automatic transmission (A/T)
18 output shaft 19 propeller shaft 20 working gear device 21 axle 22 engine output shaft 23 transmission input shaft 24 wheel 50 hydraulic control circuit 50a oil temperature sensor 51 electric oil pump (EOP)
53 Outside air temperature sensor 63 Shift position sensor 100 Control device (ECU) 101 Shift position determination section 102 Driving range standby control section 103 Hydraulic oil state determination section

Claims (3)

A control device for an automatic transmission arranged in a driving force transmission path for transmitting the power of an engine, which is a driving source, to wheels, and forming a desired gear stage by changing the engagement state of a plurality of frictional engagement elements. hand,
a driving range standby control unit that performs a driving range standby control that engages some of the driving range forming elements that form the driving range among the plurality of frictional engagement elements before switching to the driving range;
a hydraulic oil state determination unit that determines whether or not the viscosity of the hydraulic oil that operates the frictional engagement element is in a response delay state that causes a delay in response to the indicated value of the hydraulic pressure when the travel range standby control is started; ,
provided with
The travel range standby control unit is included in the travel range forming element after the oil temperature of the hydraulic oil becomes equal to or higher than a predetermined threshold value when it is determined that the viscosity of the hydraulic oil is in a delayed response state. increasing the indicated value of the hydraulic pressure that engages the brake element that is engaged from the hydraulic pressure that maintains the disengaged state of the brake element;
Automatic transmission control device. When it is determined that the viscosity of the hydraulic oil is in a delayed response state, the travel range standby control unit controls the oil temperature of the hydraulic oil to be equal to or higher than a predetermined threshold value and the oil pressure of the hydraulic oil to After a predetermined waiting period for waiting for the value before the start of engagement has passed, increasing the indicated value of the hydraulic pressure for engaging the braking element included in the driving range forming element;
A control device for an automatic transmission according to claim 1. The standby period that is set when the response delay state is determined is set when the viscosity of the hydraulic oil when the travel range standby control is started is in a response follow-up state in which the viscosity of the hydraulic oil follows the indicated value of the hydraulic pressure. longer than the waiting period,
The control device for an automatic transmission according to claim 2.

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