JP6152593B2 - Control device for automatic transmission - Google Patents

Description

  The present invention relates to a control device for an automatic transmission that is mounted on a vehicle and that can reduce a sense of incongruity when an automatic transmission is performed between multiple speeds.

2. Description of the Related Art Conventionally, a control device for an automatic transmission that reduces such a shift shock is disclosed in Patent Document 1.
When detecting that the accelerator pedal has been returned to a predetermined operation amount during downshift, the control device for the automatic transmission described in Patent Document 1 reduces the fastening capacity of the release-side fastening element and currently proceeds. The internal downshift is continued, and the engine speed is maintained at the engine speed corresponding to the gear position after the downshift, so that the rotation synchronization control is maintained.

JP 2010-2039 A

However, the conventional automatic transmission control device has the following problems.
In other words, the above-mentioned rotation synchronization control can reduce the shift shock as desired when driving at normal low and medium altitudes, but the air becomes thinner when driving at high altitudes (high altitudes). Even when the vehicle is depressed at a low / medium altitude, the engine output differs between when traveling at a low altitude and when traveling at a high altitude. In the latter case, the engine output is smaller than in the former case.
Under these conditions, if the engagement pressure of the engagement elements (such as clutches and brakes) that are switched during shifting is controlled in the same way as when traveling at low and medium altitudes, the downshift time will be prolonged when traveling at high altitudes. As a result, there is a problem that the driver feels uncomfortable.

  The present invention solves the above-described problem, and the purpose of the present invention is to enable the driver even when the rotation synchronization control is performed at the time of downshift in a situation where the engine speed is difficult to increase, for example, when traveling at a high altitude. An object of the present invention is to provide an automatic transmission control device that does not give a sense of incongruity.

For this purpose, the control device for an automatic transmission according to the present invention comprises:
In a control device for an automatic transmission that performs a downshift by releasing a first fastening element and fastening a second fastening element,
An engine speed increase control means for increasing the engine speed from the speed before the downshift to the speed after the downshift when performing the downshift;
When performing a downshift with engine speed increase control by the engine speed increase control means, if the engine speed is difficult to increase, the timing after the start of the inertia phase associated with the downshift is reached. , a fastening force increase control means for increasing the engagement force of the second engagement element than when the engine speed is at the elevated situation susceptible in the downshift,
It is provided with.

  Preferably, the fastening force increase control means performs control so that the fastening force increases as the engine rotational speed is less likely to increase.

  Preferably, the fastening force increase control means controls the fastening force to be increased when the engine speed has not increased to a predetermined engine speed after a predetermined time has elapsed since the start of the downshift. Do

 Preferably, the fastening force increase control means controls the fastening force to increase as the deviation between the gear ratio after the predetermined time has elapsed from the start of the downshift and the gear ratio after the shift increases. .

  In the automatic transmission control device of the present invention, when performing the downshift, the engine speed is increased from the speed before the downshift to the speed after the downshift, When performing a downshift accompanied by a rotational speed increase control, if the engine rotational speed is difficult to increase, the fastening force of the second fastening element is made larger than when the engine rotational speed is likely to increase. Therefore, even when the engine speed is difficult to increase, for example, when traveling on high altitudes, it is possible to prevent the downshift time from being prolonged. It can eliminate the feeling of strangeness.

  In addition, the engine is controlled so that the fastening force increases as the engine speed is less likely to increase. Therefore, even in such a situation, the downshift time is prevented from being prolonged. A sense of discomfort can be further suppressed.

  In addition, when the engine speed has not increased to the predetermined engine speed after a predetermined time has elapsed since the start of the downshift, control is performed so that the fastening force is increased. Even when the increase in the engine speed is delayed without generating the engine torque, it is possible to further suppress the sense of discomfort by suppressing the downshift time from being prolonged.

  In addition, since the greater the difference between the gear ratio at the elapse of a predetermined time from the start of the downshift and the gear ratio after the shift, the greater the engagement force, the greater the difference in gear ratio. However, it is possible to further suppress the sense of discomfort by suppressing the downshift time from being prolonged.

It is a figure which shows typically the power train of the control apparatus of Example 1 of this invention, and the automatic transmission to which this control apparatus is applied. It is a figure which shows the action | operation table | surface which shows the operation state in each gear stage of the fastening element used with the automatic transmission of FIG. It is a figure which shows the part in connection with this invention among the hydraulic control apparatuses used with the automatic transmission of FIG. It is a figure which shows the flowchart of the downshift control accompanied with the rotation synchronous control performed with the control apparatus of FIG. FIG. 5 is a diagram showing an example time chart showing temporal changes in engine speed, release side command hydraulic pressure, engagement side command hydraulic pressure, etc. when downshift control with rotation synchronization control is executed along the flowchart of FIG. 4. is there.

  Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.

  First, a control device according to a first embodiment and an automatic transmission to which the control device is applied will be described with reference to FIG. These configurations are the same as those described in the above-mentioned Patent Document 1 relating to the application of the present applicant.

That is, as shown in FIG. 1, the power train of the automatic transmission (schematically showing only the upper half of the center rotation shaft) is connected to the torque converter TC with a lockup mechanism LUC connected to the output shaft of the engine Eg. Connected to drive the torque converter TC and the oil pump OP.
The automatic transmission includes four sets of single pinion type planetary gear sets including a first planetary gear G1, a second planetary gear G2, a third planetary gear G3, and a fourth planetary gear G4.

The first planetary gear G1 includes a first sun gear S1, a first ring gear R1, a first pinion P1, and a first pinion carrier PC1, and the second planetary gear G2 includes a second sun gear S2 and a second ring gear R2. , Second pinion P2, and second pinion carrier PC2, third planetary gear G3 has third sun gear S3, third ring gear R3, third pinion P3, and third pinion carrier PC3, The four planetary gear G4 includes a fourth sun gear S4, a fourth ring gear R4, a fourth pinion P4, and a fourth pinion carrier PC4.
In the above planetary gear, the first planetary gear G1 and the second planetary gear G2 constitute a first planetary gear set GS1 composed of four rotating elements connected by a first connecting member M1 and a third connecting member M3. Similarly, the third planetary gear G3 and the fourth planetary gear G4 are connected by a second connecting member M2 to constitute a second planetary gear set GS2 composed of five rotating elements.
Further, the input from the torque converter TC to the planetary gear is performed from the input shaft Input, and the output from the planetary gear is taken out from the output shaft Output.

  The automatic transmission has nine frictional engagement elements to change the connection relationship of the planetary gears, that is, input clutch C1, direct clutch C2, H & LR clutch C3, front brake B1, low brake B2, 2346. A brake B3, a reverse brake B4, a first one-way clutch F1, and a second one-way clutch F2 are provided.

  The operation of these fastening elements is performed based on the fastening table shown in FIG. In this fastening table, a circle mark indicates that the fastening element is in a fastening state, and a circle mark indicates that the fastening element is in a fastening state when a range position where the engine brake is operated is selected. Indicates that the fastening element is in the released state.

  On the other hand, the control system includes an engine controller (ECU) 10 that controls the engine Eng, a control valve unit (CVU) 30 that controls the hydraulic pressure that is supplied to and removed from the fastening elements of the automatic transmission, and an automatic that controls the CVU 30. And a transmission controller (ATCU) 20. Here, the ECU 10 and the ATCU 20 constitute the engine speed increase control means of the present invention, and the ATCU 20 and the CVU 30 constitute the fastening force increase control means of the present invention.

  The ECU 10 is connected to an accelerator pedal operation amount sensor (APO sensor) 1 for detecting an accelerator pedal operation amount, an engine rotation speed detection sensor 2, and the like, and controls engine speed and engine torque based on detection signals from these. To do.

The ATCU 20 includes a first turbine rotation speed sensor 3 that detects the rotation speed of the first carrier PC1, a second turbine rotation speed sensor 4 that detects the rotation speed of the first ring gear R1, an output shaft rotation speed sensor 5, and an inhibitor switch 6. The altitude sensor 7 and the like are connected, and an optimum gear is selected based on these signals (vehicle speed Vsp, etc.) and the accelerator pedal operation amount APO received from the ECU 10 side, and a control signal is sent to the CVU 30.
As the altitude sensor 7, in this embodiment, a global positioning satellite system (GPS) is used, and altitude information at that time is obtained from stored map information based on the detected current position of the vehicle.

  The CVU 30 has a large number of valves and solenoids, and adjusts the hydraulic pressure supplied from the oil pump OP to the hydraulically operated fastening elements (clutch C1 to C3, brakes B1 to B4) based on the control signal received from the ATCU20. Supply with pressure, or remove the supplied hydraulic pressure.

  The details of the above configuration and the operation thereof have been described in the above-mentioned Patent Document 1, and therefore the description thereof is omitted here.

FIG. 3 shows a hydraulic circuit diagram of a part related to the present invention in the CVU 30.
Therefore, here, the hydraulic circuit supplied mainly to the low brake B2, the input clutch C1, the H & LR clutch C3, and the 2346 brake B3 will be described.

  The CVU 30 includes an oil pump OP, a pressure regulator valve 31 that regulates the line pressure, and a manual valve 32 that switches a supply path to each fastening element. The discharge pressure of the oil pump OP is adjusted according to the opening degree of the drain port of the pressure regulator valve 31 controlled by the solenoid SOL to become a line pressure. The line pressure is supplied to each fastening element or the like according to the oil passage switched in the manual valve 32.

  The low brake B2 is frictionally fastened by pressing a plurality of first friction plates 33 and second friction plates 34, which are alternately arranged, by the pressing force of the pistons 35 and 36, respectively. The pistons 35 and 36 are integrally formed with a first piston 35 having a small pressure receiving area and a second piston 36 having a large pressure receiving area. Accordingly, the first hydraulic chamber 37 that applies hydraulic pressure to the first piston 35 and the second hydraulic chamber 38 that applies hydraulic pressure to the second piston 36 can be supplied with hydraulic pressure independently, and each shift stage to be fastened. Either one or both of the first piston 35 and the second piston 36 selected according to the pressure is a pressing force determined by the product of the hydraulic pressure and the pressure receiving area, and the engagement capacity of the low brake B2 at that time .

  The hydraulic circuit of the low brake B2 includes a pressure regulating valve 39 that regulates the hydraulic pressure supplied to the low brake B2, a first switching valve 40 that opens and closes a hydraulic supply oil passage to the first hydraulic chamber 37, and a second hydraulic chamber 38. A second switching valve 41 that opens and closes the hydraulic supply oil passage is provided.

Note that the valve opening degree of the pressure regulating valve 39 is controlled according to the operation amount of the linear solenoid 50. The first switching valve 40 establishes communication between the pressure regulating valve 39 and the first hydraulic chamber 37 in accordance with the signal pressure input to the ON / OFF solenoid 51, and the hydraulic chamber and drain port of the input clutch C1. Between the first position in which the valve is in communication and the pressure regulating valve 39 and the first hydraulic chamber 37 are not in communication, the first hydraulic chamber 37 is in communication with the drain port, and the hydraulic chamber of the input clutch C1 and the pressure regulating valve 41 is switched to any one of the second positions where the communication is established.
Here, the solenoid 51 is controlled to be OFF while the oil pressure is generated in the input clutch C1 (while the oil pressure command is being issued), and ON when the oil pressure command for the input clutch C1 is zero.

    The second switching valve 41 uses the hydraulic pressure supplied to the input clutch C1 and the direct clutch C2 as a signal pressure, and the hydraulic pressure is supplied to the input clutch C1 and the direct clutch C2 between the pressure regulating valve 39 and the second hydraulic chamber 38. When the hydraulic pressure is supplied to the input clutch C1 or the direct clutch C2, the first position is set to the communication state when not connected, and the second position is set to the non-communication state when the hydraulic pressure is supplied to the input clutch C1 or the direct clutch C2.

    Similarly, the hydraulic circuit of the input clutch C1, the H & LR clutch C3, and the 2346 brake B3 includes the pressure regulating valves 42, 43, 43, 44 for regulating the hydraulic pressure supplied to the respective engagement elements, and the valve opening of each pressure regulating valve. Linear solenoids 52, 53, and 54 to be controlled are included.

    The line pressure supplied from the manual valve 32 to the hydraulic circuit of the low brake B2 is regulated by the pressure regulating valve 39 to become the low brake operating hydraulic pressure. The low brake operating hydraulic pressure is not supplied when both the first switching valve 40 and the second switching valve 41 are in the second position, and one of the first switching valve 40 and the second switching valve 41 is the first. Is supplied to the first hydraulic chamber 37 or the second hydraulic chamber 38 via the switching valve in the first position, and the first switching valve 40 and the second switching valve 41 are When both are in the first position, the first hydraulic chamber 37 and the second hydraulic chamber 38 are supplied.

    That is, as shown in the engagement table of FIG. 2, the low brake B2 is engaged only at the 1st to 3rd speeds, but the optimum engagement capacity of the low brake B2 differs depending on the shift speed. Therefore, since the torque ratio (sharing torque) is large at the first speed and the second speed among the first to third speeds, a larger fastening capacity is required between the first friction plate 33 and the second friction plate 34. Yes, both the first switching valve 40 and the second switching valve 41 are in the first position. At the third speed, since the torque ratio is relatively small, a large fastening capacity is not required between the first friction plate 33 and the second friction plate 34, and only the first switching valve 40 is in the first position. The second switching valve 41 is controlled to be in the second position.

In such an automatic transmission, for example, when downshifting from the 4th speed to the 3rd speed, the engaged H & LR clutch C3 is released and the low brake B2 is engaged . Here, the release-side H & LR clutch C3 corresponds to the first engagement element of the present invention, and the engagement-side low brake B2 corresponds to the second engagement element of the present invention.
If the H & LR clutch C3 and the low brake B2 are engaged at the same time in switching between the two engagement elements, an interlock or the like will occur, causing a sudden deceleration G in the vehicle, or the parts will be damaged in the worst case. To do. Therefore, simultaneous engagement of the H & LR clutch C3 and the low brake B2 is avoided by the first and second switching valves 40, 41.

    On the other hand, the ATCU 20 receives detection signals from the first turbine rotation speed sensor 3, the second turbine rotation speed sensor 4, the output shaft rotation speed sensor 5, the inhibitor switch 6, the APO sensor 1, and the like, and receives solenoids 50 to 54 of the CVU 30. Etc. are controlled. For example, the gear position is determined using a shift line map stored in the ATCU 20 based on the vehicle speed and the accelerator pedal operation amount.

Here, of these ATCU20 controls, the downshift control for performing the rotation synchronization control related to the present invention will be described. The downshift includes a downshift based on various causes. In this embodiment, a manual downshift performed by a driver's select lever operation during driving will be described as an example with reference to the flowchart of FIG. .
In this control, each time change of the engine speed, the engine rotation synchronization control flag, the gear ratio, the release side command pressure, and the engagement side command pressure is shown in the time chart of FIG.

First, in step S1, it is determined whether or not a downshift command accompanied by rotation synchronization control is output.
This determination is made based on the vehicle speed signal, the accelerator operation amount signal, the current gear position, the inhibitor switch 6 and the like.
If the determination result in step S1 is YES, the process proceeds to step S2, and if NO, the process returns to the first step without performing rotation synchronization control.
In the present embodiment, as described above, the manual operation in which the driver has moved the select lever to the shift-down traverse position will be described for the case where the inhibitor switch 6 detects and a downshift command is issued.

  In step S2, the current altitude of the host vehicle is detected from the altitude sensor. Then, it progresses to step S3.

    In step S3, an engagement side instruction oil pressure signal (precharge control signal) instructing supply to the hydraulic chamber to the fastening element to be engaged, and an instruction to drain oil from the hydraulic chamber of the fastening element to be released. A release-side command hydraulic pressure signal and an engine rotation synchronization control flag signal for increasing the engine speed so that the engine speed of the engine Eg becomes the speed after shifting are output. Then, it progresses to step S4.

In step S4, the increasing gradient of the engagement side command hydraulic pressure is set according to the height of the altitude detected in step S2. These relationships are stored in advance in the ATCU 20 as a map.
Then, it progresses to step S5.

  In step S5, it is determined whether a predetermined time has elapsed since the start of shifting. The predetermined time is a time for starting to increase the engagement-side command hydraulic pressure when the altitude is not high altitude and the vehicle is traveling on a low ground. If the determination result is YES, the process proceeds to step S6, and if NO, the process proceeds to step S8.

  In step S6, the gears change from the turbine rotational speed detected by the first turbine rotational speed sensor 3, the second turbine rotational speed sensor 4, and the turbine rotational speeds detected by the output shaft rotational speed sensor 5 and the output rotational speed. A ratio is calculated at any time, and it is determined whether or not the calculated gear ratio has reached a predetermined gear ratio. The predetermined gear ratio is a gear ratio immediately before reaching the gear ratio after the shift. If the determination result is YES, the process proceeds to step S7, and if NO, the process returns to step S5.

  In step S7, the hydraulic pressure supplied to the fastening element on the fastening side is raised to the maximum pressure, and a complete fastening process for completely fastening the fastening element on the fastening side is performed. Then, it returns to the beginning of this control.

  On the other hand, in step S8, it is determined whether or not the calculated gear ratio has reached a predetermined gear ratio. If the determination result is YES, the process proceeds to step S7, and if NO, the process proceeds to step S9.

In step S9, the increasing gradient of the engagement-side command hydraulic pressure is set to a gradient according to the difference between the gear ratio after a predetermined time has elapsed and the gear ratio after the shift. This gradient is set separately from the gradient set based on the altitude, and is set so that the gradient increases as the deviation increases.
Subsequently, the process returns to step S8.

The above is the flow of the downshift control accompanied with the rotation synchronization control. An example of the temporal change of the gear ratio, the hydraulic pressure, etc. at this time will be described with reference to FIG.
In FIG. 5, the downshift control at high altitude traveling with the rotation synchronization control of the present embodiment is indicated by a solid line, and the engine speed is maintained even if a predetermined time elapses during traveling on a flat ground at low and medium altitudes. The downshift control when the vehicle does not rise is indicated by a one-dot chain line, and the downshift control at the time of traveling at high altitude without the rotation synchronization control of this embodiment is indicated by a broken line.

  When a downshift command is issued from ATCU 20 at time t1 (step S1), an engine rotation synchronization control flag rises (for example, is set to a value of 1) and is output to ECU 10, so that the engine speed becomes the speed after shifting. Control to increase the engine speed. Further, the release side instruction hydraulic pressure signal is output to the CVU 30 so that the hydraulic chamber of the release side engagement element becomes zero, and the engagement side instruction oil pressure is started so as to start the precharge of the hydraulic pressure to the hydraulic chamber of the engagement side engagement element. A signal is output to CVU 30 (step S3). In this precharge, the piston of the fastening element on the fastening side overcomes static friction and moves as a slightly higher hydraulic pressure within a short period of time from time t1, and a signal is output immediately after this to achieve a lower constant hydraulic pressure. .

  At time t2 when a little time has elapsed from time t1 due to the draining of oil from the release side fastening element and precharging to the fastening side fastening element, the gear ratio starts to change, and the shift in the inertia phase is started. As a result, the gear ratio starts to increase, and the rotational speed of the engine Eg starts to increase.

  At time t3, the precharge to the fastening side fastening element is completed, the command hydraulic pressure to the fastening side fastening element is increased with a gradient corresponding to the detected altitude (step S2), and output to the CVU 30 (step S4). Therefore, after time t3, the engagement-side command hydraulic pressure gradually increases. At this time, the engine speed and gear ratio continue to increase.

  At time t4 (within a predetermined time: step S6), the gear ratio reaches the predetermined gear ratio (step S6). Then, complete fastening of the fastening side fastening element is started (step S7). Therefore, the hydraulic pressure to the fastening side fastening element is increased to a maximum pressure with a higher gradient than before.

  At time t5 immediately after this, the gear ratio reaches the gear ratio after the shift. At this time, the engine rotation synchronization control flag is set to 0, and the rotation synchronization control of the engine Eg is also terminated.

  At time t6, the engagement side engagement command pressure is increased to the maximum value, and the downshift control is completed.

  On the other hand, if the engine Eg speed does not increase to the predetermined engine speed even after a predetermined time (time from time t1 to time t7) while traveling on flat ground, the engagement side command pressure is increased from time t7. The precharge constant pressure is increased with a gradient corresponding to the gear ratio (step S9).

  When the gear reaches a predetermined gear ratio at this time t4 ′ due to this pressure increase (step S8), the specified hydraulic pressure on the engagement side is increased with a larger gradient to complete engagement (step S7).

Then, at time t6 ′, the downshift control ends.
The above is an example of downshift control with engine rotation synchronization control according to the present embodiment.

On the other hand, in the downshift control during high altitude travel without the downshift control during high altitude travel according to the present invention, as shown by the broken line in FIG. 5, the gear ratio is predetermined at time t4 ″ later than the time t6 ′. From this point in time, the designated hydraulic pressure on the engagement side is increased with a larger gradient and complete engagement is performed.
Therefore, the downshift control is completed at a later time t6 ''.

As can be seen from the above description, the control device for the automatic transmission according to the present embodiment can obtain the following effects.
In other words, when performing a downshift, the engine speed is increased from the speed before the downshift toward the speed after the downshift, and when traveling at a high altitude (a situation where the engine speed is difficult to increase). In this case, since the fastening force of the fastening element of the fastening element to be fastened is larger than that in the case of low-altitude travel (a situation where the engine speed tends to increase), downshifting during high-altitude travel Prolonging time can be suppressed, and thereby, it is possible to prevent the driver from feeling uncomfortable at the time of downshifting when traveling at a high altitude.

In the downshift control, the fastening force is increased as the engine speed is difficult to increase, such as the altitude is increased.
As a result, even in such a situation, it is possible to perform optimal control and to eliminate a sense of incongruity.

In the downshift control, when the engine speed has not increased to a predetermined engine speed after a predetermined time has elapsed since the start of the downshift, the fastening force is increased.
As a result, even if the target engine torque cannot be obtained after the start of the rotation-synchronized downshift and the increase in the rotational speed of the engine Eg is delayed, it is possible to prevent the downshift time from being prolonged. .

Further, the fastening force is increased as the difference between the gear ratio after the elapse of a predetermined time from the start of the downshift and the gear ratio after the shift is larger.
Thereby, even when the gear ratio deviation is large, it is possible to further suppress the downshift time from being prolonged.

  The present invention has been described based on the above embodiments. However, the present invention is not limited to these embodiments, and is included in the present invention even when there is a design change or the like without departing from the gist of the present invention. .

  For example, although the GPS is used as the altitude sensor 7 in the present embodiment, the altitude sensor 7 is not limited thereto, and for example, an atmospheric pressure sensor or the like may be used.

  In the above embodiment, the rotation synchronous downshift control is started by manual operation in the downshift direction of the driver when traveling in the coast state. However, the present invention is not limited to this, and the power-on state in which the accelerator pedal is depressed. It may be a case where the vehicle is downshifted by the vehicle, or may be a case where the ATCU 20 automatically downshifts based on the shift map based on the operation amount of the accelerator pedal and the vehicle speed.

  In the above embodiment, the fastening force is increased by increasing the command hydraulic pressure of the fastening side fastening element during the inertia phase at a predetermined gradient. For example, the fastening force can be increased by offsetting the command hydraulic pressure by a predetermined amount. Other methods such as increasing the size may be used.

  Further, in the above embodiment, the situation in which the engine speed is difficult to increase is determined based on the altitude, but the engine speed is increased by this magnitude by comparing the generated engine torque with a predetermined torque value. You may make it judge the difficult situation.

  Further, in the above embodiment, when the engine speed has not increased to the predetermined speed within a predetermined time, an instruction is given with a gradient set based on the difference between the gear ratio when the predetermined time has elapsed and the gear ratio after the shift. Although the hydraulic pressure is increased, the increasing gradient of the command hydraulic pressure may be corrected based on this deviation.

In the above-described embodiment, the case where the engine speed is difficult to increase is described as traveling at a high altitude. However, the present invention is not limited to this, and the engine speed is difficult to increase even when the altitude is not high. In such a case, the fastening force increase may be controlled.
Needless to say, the automatic transmission and the hydraulic circuit are not limited to those shown in FIGS.

1 Accelerator pedal operation amount sensor
2 Engine speed sensor
3 First turbine rotation speed sensor
4 Second turbine rotation speed sensor
5 Output shaft rotation speed sensor
6 Inhibitor switch
7 Advanced sensor
10 Engine controller
20 Transmission controller
30 Hydraulic control valve
B1 Front brake
B2 Low brake
B3 2346 brake
C1 input clutch
C2 H & LR clutch

Claims (4)

In a control device for an automatic transmission that performs a downshift by releasing a first fastening element and fastening a second fastening element,
Engine speed increase control means for increasing the engine speed from the speed before the downshift to the speed after the downshift when performing the downshift;
When downshifting with engine speed increase control by the engine speed increase control means is performed and the engine speed is difficult to increase, the timing at which the inertia phase associated with the downshift starts Later, a fastening force increase control means for controlling the fastening force of the second fastening element to be larger than when the engine speed is likely to increase during the downshift,
A control device for an automatic transmission, comprising: The control apparatus for an automatic transmission according to claim 1,
The fastening force increase control means controls the fastening force to increase as the engine speed is more difficult to increase.
A control device for an automatic transmission. In the automatic transmission control device according to claim 1 or 2,
The fastening force increase control means controls the fastening force to be increased when the engine speed has not increased to a predetermined engine speed after a predetermined time has elapsed from the start of the downshift.
A control device for an automatic transmission. The control device for an automatic transmission according to any one of claims 1 to 3,
The fastening force increase control means controls the fastening force to increase as the deviation between the gear ratio after the predetermined time elapses from the start of the downshift and the gear ratio after the shift increases.
A control device for an automatic transmission.

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