JP3482774B2 - Shift-up lock-up control device for automatic transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lockup control device for a torque converter during upshifting of an automatic transmission.

[0002]

2. Description of the Related Art An automatic transmission has a torque converter that requires a torque increasing function and a torque fluctuation absorbing function in its transmission system. However, since the torque converter causes slip between input and output elements, power transmission efficiency is increased. I cannot help getting worse.

Therefore, in today's torque converters, when shifting to an operating state that does not require the torque increasing function or the torque fluctuation absorbing function, the input / output elements are mechanically directly connected from the converter state in which the slip limitation is not performed between the input / output elements. It is often a lock-up type that can switch to the lock-up state.

In lock-up control of the torque converter, when a lock-up area is individually set for each of a plurality of shift speeds, gear shifting occurs in the lock-up state. Since a large shift shock occurs because the torque fluctuation absorbing function of the torque converter cannot be used at the time of the shift, it is common to temporarily release the lockup of the torque converter during the shift even in the lockup region. Target.

By the way, if the lockup is released each time during the shift, the fuel consumption improving effect by the lockup is lowered, and there is a disadvantage in terms of shock.

Therefore, it has been previously proposed that the lockup capacity of the torque converter is feedback-controlled such that the torque converter slip amount becomes a predetermined value, instead of completely unlocking the torque converter during gear shifting.

In such feedback control of the torque converter slip amount, the effective gear ratio represented by the input / output rotation ratio of the automatic transmission changes from the gear ratio before gear shift to the gear ratio after gear shift from the instant of the gear shift command. It is effective in the first phase (torque phase) until the start, but when the effective gear ratio is switched to the second phase (inertia phase) that changes from the gear ratio before shifting to the gear ratio after shifting,
Depending on the change width of the effective gear ratio, the slip amount measured value may exceed 0 and the polarity may be reversed regardless of the actual torque converter slip amount.

By the way, the relationship between the slip amount and the lockup capacity of the torque converter is an absolute value function that returns when the slip amount is 0. Therefore, the relationship between the slip amount and the increase or decrease of the lockup capacity is as follows. Reverse when the slip amount is 0. For this reason, when the slip amount increases to the negative side during the above phase transition, the lockup capacity increases, and the lockup of the torque converter proceeds. Therefore, the simple feedback control of the torque converter slip amount causes a problem that the original purpose of preventing the shift shock by setting the torque converter in the slip state cannot be achieved.

Therefore, when the shift shock is suppressed by feedback control of the torque converter slip amount,
It is necessary to add means for detecting the transition to the second phase and switching the control logic so as to match the above-mentioned actual situation, or to add means for switching the control logic so as to match the above-mentioned actual situation depending on whether the slip amount is positive or negative. There is. For this reason, the structure is inevitably complicated and the cost is high, and it is difficult to achieve compatibility with slip control during vehicle deceleration.

It is also conceivable to estimate the torque converter slip amount during gear shift and perform feedback control of the lockup capacity of the torque converter based on this, but in this case also the structure becomes complicated and the slip amount is also increased. When the estimated value has a large error, the torque converter shifts to the lockup side, and it is impossible to prevent shift shock.

In order to solve these problems, conventionally, as described in Japanese Patent Laid-Open No. 172239/1993, the lockup capacity of the torque converter is once set within a range in which the torque converter does not slip when a shift command is issued. With the minimum lockup capacity, the measures to prevent shift shock were proposed.

[0012]

However, since the clutch that controls the shift is slipping during the shift, the transmission input revolution cannot be obtained by multiplying the transmission output revolution by the gear ratio. Therefore, it is also impossible to obtain the slip amount of the torque converter, which is calculated as the difference between this and the engine speed. Therefore, in the measures described in the above literature, in setting the lockup capacity to the minimum value, there is no choice but to rely on feedforward control and learning control.

In the learning control, the control output cannot be determined in real time when the control is actually required, that is, the control output cannot be determined in real time. However, the actual situation was that the gear shift shock reduction effect that was aimed at could not be achieved.

The present invention solves the above problems,
Based on the fact that there is an absolute value function relationship with the lockup capacity as described above, and that the learning control is unavoidable due to monitoring the torque converter slip amount, the torque converter slip during shifting The control is not the torque converter slip amount, but the
The engine speed at the time of commanding an upshift
The target rotational speed obtained by adding a constant offset value and the engine rotational speed, which has a limit function having dead zones at the upper and lower limits with respect to the lock-up capacity, is used as a control input to perform slip control of the torque converter. The purpose is to solve the problem.

Incidentally, the engine speed may not respond to the increase or decrease of the lockup capacity in the dead zone, but the increase / decrease relationship does not reverse with respect to the increase or decrease of the lockup capacity. The problem of having to switch can be eliminated.

However, performing the slip control of the torque converter by using the engine speed as a control input during the gear shift as described above is effective only in the case of so-called upshift gear shift in which the engine speed is lowered by the gear shift. At the instant of the shift command for the upshift, the control input for slip control is switched from the torque converter slip amount to the engine speed.

[0017]

For the above purpose, the first
A lockup control device for an automatic transmission according to the present invention is a shift-up control device for an automatic transmission, wherein engine rotation is input through a lockup-capable torque converter. , Setting a target speed obtained by adding a predetermined offset amount to the engine speed at the time of commanding the upshift
At the same time, the engine speed is low due to the upshift shifting.
When you start to lower the engine speed from the target speed
The torque converter's
It is characterized in that the lockup is controlled by the release side .

According to a second aspect of the present invention, there is provided a lockup control device for an automatic transmission during shifting, wherein
The invention is characterized in that the engine speed at the time of the upshift gearshift command is obtained by multiplying the transmission output speed at the time of the upshift gearshift command by the gear ratio before gear shift.

According to a third aspect of the present invention, there is provided a lock-up control device for an automatic transmission, which is the shift-up lock-up control device according to the third aspect of the present invention. It is characterized in that the torque converter slip is reduced as the slip amount increases.

According to a fourth aspect of the present invention, there is provided a lock-up control device for an automatic transmission during a shift, in which the engine speed at the time of an up-shift gear shift command is determined based on the engine speed at the time of an up-shift gear shift command. It is configured to terminate the lockup control of the torque converter that maintains the engine speed at the target speed when the engine speed drops to the gear ratio change start determination engine speed determined by subtracting the offset amount of It is characterized by.

According to a fifth aspect of the present invention, there is provided a lockup control device for an automatic transmission during shifting, which is characterized in that, in any one of the first to third inventions, the engine speed at the time of an upshift gearshift command, Gear ratio change start judgment corresponding to a predetermined internal division point between the engine speed and the engine speed after gear shift calculated from the gear ratio after gear shift. The lockup control of the torque converter for maintaining the target rotation speed is terminated.

According to a sixth aspect of the present invention, in a shift-up lockup control device for an automatic transmission according to the sixth or fifth aspect, the engine speed at the time of the upshift gearshift command is upshifted. The present invention is characterized in that the transmission output speed at the time of a gear shift command is obtained by multiplying the gear ratio before gear shift.

According to a seventh aspect of the present invention, there is provided a lock-up control device for an automatic transmission during a shift, wherein the command value of the lock-up control is a shift shock. The torque converter lock-up control for maintaining the engine speed at the target rotation speed is terminated when the value corresponding to the slip state of the torque converter can be suppressed.

According to an eighth aspect of the present invention, there is provided a lockup control device for an automatic transmission during shifting, in which the engine rotational speed reaches the target rotational speed according to any one of the first to seventh inventions. It is characterized in that a predetermined offset value is added to the lockup control command value of the torque converter at the time to obtain the lockup control command initial value.

According to a ninth aspect of the present invention, there is provided a lockup control device for an automatic transmission during shifting, which maintains the engine rotational speed at the target rotational speed according to any one of the fourth to seventh inventions. The present invention is characterized in that a predetermined offset value is added to the lockup control command value of the torque converter when the lockup control of the torque converter is terminated to obtain the lockup control command initial value.

According to a tenth aspect of the present invention, there is provided an eighth aspect of the lock-up control device for an automatic transmission during shifting.
In the invention or the ninth invention, the offset value is learned and controlled so that a time required for the engine speed to converge to the target speed becomes a predetermined time.

[0027]

According to the first aspect of the present invention, during the upshifting of the automatic transmission, the target rotational speed obtained by adding a predetermined offset amount to the engine rotational speed at the time of commanding the upshift is set, and Upshift
If the engine speed starts to decrease,
Based on the rotational speed deviation obtained by subtracting the engine rotational speed from
The lockup of the torque converter is controlled to the release side . Therefore, even if the upshift is performed in the lockup range, the torque converter is put in the slip state, and the upshift is not executed while the torque converter is kept in the lockup state. Can be prevented.

By the way, when the torque converter is put into the slipping state as described above, the engine speed is maintained at the target speed obtained by adding a predetermined offset amount to the engine speed at the time of the upshift gear shift command. The slip state is caused in this manner, and as a result, the torque converter is slip controlled with the engine speed that is in the relation of the limit function having the dead zones at the upper and lower limits for the lockup capacity as the control input. It is possible to eliminate the above-mentioned problem that the logic needs to be switched. In addition, when the engine speed is used as the control input as described above, the control only needs the feedback control, and the learning control is not always necessary. Due to this, in real time, there is no error due to convergence residuals or erroneous learning, and The shock reduction effect can be achieved exactly as intended.

In the second aspect of the invention, the engine speed at the time of the upshift gearshift command is obtained by multiplying the transmission output speed at the time of the upshift gearshift command by the gear ratio before gearshift, so that the upshift gearshift is induced. Even if the engine speed at the time of an upshift gear shift command varies depending on the throttle operation method, the target speed of the engine can be made to match the actual situation, and the shift shock mitigating effect of the first aspect of the invention can be further ensured. Can be something.

In the third aspect of the present invention, the offset amount of the engine speed is reduced as the torque converter slip amount when the upshift gearshift command is increased, so that the torque converter slip amount when the upshift gearshift command is issued is sufficient. However, it is possible to eliminate the adverse effects that the torque converter is further made to be a converter tendency, the fuel consumption is deteriorated due to the excessive slip amount, and the re-lockup after the gear shift has a large response delay.

According to the fourth aspect of the present invention, when the engine speed decreases to the gear ratio change start determination engine speed obtained by subtracting a predetermined offset amount from the engine speed at the time of an upshift gear change command, the engine speed is set to the engine speed. The lockup control of the torque converter for maintaining the target rotation speed is ended.

In this case, it is possible to prevent the lock-up of the torque converter from being completely released during the slip control, and the re-lock-up after the end of the shift has a large response delay. Therefore, it is possible to eliminate the adverse effect that the fuel efficiency is deteriorated.

According to the fifth aspect of the invention, a gear corresponding to a predetermined internal division point between the engine speed at the time of the upshift gear shift command and the engine speed after gear shift calculated from this engine speed and the gear ratio after gear shift. Ratio change start determination When the engine speed drops to the engine speed, lockup control of the torque converter for maintaining the engine speed at the target speed is terminated. In this case, the control end timing can be more matched to the actual situation, and the above-described operational effect of the fourth invention can be made more prominent.

In the sixth invention, the fourth invention or the fifth invention
According to the invention, the engine speed at the time of the upshift gearshift command is obtained by multiplying the transmission output speed at the time of the upshift gearshift command by the gear ratio before gearshift. Even if the engine speed at the time of gear change command is different,
The target speed of the engine can be made to match the actual situation, and the above-described action and effect of the fourth invention or the fifth invention can be further ensured.

In a seventh aspect of the invention, lockup control of the torque converter for maintaining the engine speed at the target number of revolutions according to any one of the first to third aspects,
The lockup control is ended when the command value reaches a value corresponding to the slip state of the torque converter capable of suppressing shift shock.

Also in this case, like the fourth invention, it is possible to prevent the lockup of the torque converter from being completely released during the slip control of the torque converter.
It is possible to eliminate the adverse effect that the re-lockup after the completion of the gear shift has a large response delay and the fuel consumption is deteriorated.

In the eighth aspect of the present invention, the lockup control command initial value is obtained by adding a predetermined offset value to the lockup control command value of the torque converter when the engine speed reaches the target rotation speed. Even when the torque converter is in the complete lockup state at the time of the shift / shift command, the torque converter can be quickly put into a predetermined slip state to speed up the control convergence.

In the ninth aspect of the invention, the lockup control command value of the torque converter at the time of ending the lockup control of the torque converter for maintaining the engine speed at the target speed is locked by adding a predetermined offset value. Since the up control command is set to the initial value, the same operational effect as in the eighth aspect can be achieved in this case as well.

In the tenth invention, the offset value in the eighth invention or the ninth invention is learned and controlled so that the time required for the engine speed to converge to the target speed becomes a predetermined time. The effects of the eighth invention and the ninth invention can be made more remarkable.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a shift-up lock-up control device for an automatic transmission according to an embodiment of the present invention. In FIG. 1, 1 is an engine and 2 is an automatic transmission. The automatic transmission 2 receives the rotational power of the engine 1 via the torque converter 3, changes the input rotation at a gear ratio according to the selected gear, and transmits it to the output shaft 4.

Here, the engine 1 is provided with a throttle valve 6 whose opening is increased by depressing an accelerator pedal 5 operated by a driver, and sucks air in an amount corresponding to the opening of the valve 6 and the engine speed. To do. The engine 1 includes a fuel injection valve and an ignition device (not shown) provided for each cylinder, and these are controlled by an engine controller (not shown). As is well known, this engine controller controls the opening of an unillustrated fuel injection valve so that the air-fuel ratio becomes a stoichiometric air-fuel ratio to supply fuel to the engine 1, and at the same time, operates the engine through an unillustrated ignition device. It is assumed that the ignition plug of a predetermined cylinder is ignited with a predetermined timing to control the operation of the engine 1.

On the other hand, in the automatic transmission 2, the shift solenoids 11 and 12 in the control valve 10 are turned on,
The first to fourth speeds are selected depending on the combination of OFF, and the torque converter 3 uses the duty D of the lock-up solenoid 13 in the control valve 10 to lock the torque converter input / output elements (not shown). It is assumed that the up-clutch piston can be in a lock-up state in which it is mechanically directly connected, or can be in a converter state in which the direct connection is released. Here, the duty D of the lockup solenoid 13 is a lockup control command value, and as the torque D increases, the engagement force (lockup capacity) of the lockup clutch piston is gradually increased to shift the torque converter 3 from the converter state to the lockup state. Slip control shall be performed.

ON / OFF of shift solenoids 11 and 12
F, and the duty D of the lockup solenoid 13
Controls these with the transmission controller 14, and the controller 14 is provided with an opening TV of the throttle valve 6.
A signal from a throttle opening sensor 15 that detects O, a signal from an engine rotation sensor 16 that detects the rotation speed N _e of the engine 1, and a gear shift that detects the rotation speed N _o of the transmission output shaft 4 are input. The signals from the machine output rotation sensor 17 are input respectively.

The transmission controller 14 executes a shift control program (not shown) on the basis of the above various input information to control the shift of the automatic transmission 2 through ON / OFF of the shift solenoids 11 and 12, and 2 to 4
Execute the shift-up lockup control program shown in
Through the duty D of the lockup solenoid 13, the lockup control during shifting of the torque converter 3, which is the object of the present invention, is performed as described later.

First, the gear shift control will be briefly described. The controller 14 controls the throttle opening TV detected by the sensor 15.
From O and the vehicle speed that can be obtained from the transmission output speed N _o detected by the sensor 17, a suitable shift speed is calculated based on a shift map that is not shown, and the preferred shift speed and the currently selected shift speed are calculated. If they match, the shift solenoids 11 and 12
If the ON and OFF states are not changed and if they do not match, the shift solenoids 11 and 12 are switched ON and OFF so as to obtain the suitable shift speed, thereby shifting to the suitable shift speed.

Next, to explain the lock-up control during shifting in FIGS. 2 to 4, the controller 14 first determines in step 21 in FIG. 2 from the shifting flag whether shifting is in progress or non-shifting is in progress. . If the gear shift is not being performed, in step 22, the drive duty D of the lock-up solenoid 13 is determined and output so that the slip amount represented by the difference between the input and output rotational speeds of the torque converter becomes a predetermined slip amount according to the operating state. Perform feedback control. Next, at step 23, for lock-up control at the time of up-shift gear shifting which is the object of the present invention, an initialization flag, which will be described later, is turned on and the control ends.

If it is determined in step 21 that the gear shift is in progress, in step 24 whether the gear shift is an upshift gear shift,
Determine if it is a downshift. If it is a downshift, it is not a shift for which lockup control is aimed at by the present invention, so the control proceeds to step 25, where the drive duty of the lockup solenoid 13 is controlled by the lockup control for the downshift. D is determined and output to the solenoid 13.

When it is determined in step 24 that the shift is an upshift shift, the lockup control during shift of the torque converter, which is the object of the present invention, is performed by the processes of steps 26 to 33 as follows. That is, in step 26, it is determined whether or not the entry into the loop is the first one depending on whether or not the initialization flag is ON, and if it is the first, steps 27 and 28 are executed only once, 28
By turning off the initialization flag in step 2, steps 27 and 28 are skipped after the second time.

Here, in step 27, the following initialization control is executed by the processing shown in FIG. In step 41 of FIG. 3, the gear ratio before shifting is multiplied by the current transmission output rotational speed N _o to obtain the engine rotational speed at the time t ₁ of the upshift gearshift command of FIG. 5, which is also shown in FIG. The torque converter target slip amount α (offset amount) for the lockup control at the time of upshift shifting is added to calculate the engine speed target value N _e0 for the lockup control at the time of upshift shifting.

Next, at step 42 of FIG. 3, the engine speed N _eS for judging the start of the gear ratio change (start of the second phase) also shown in FIG. 5 is set to the internal dividing point of 2: 8 between the engine speeds before and after the gear shift. Determine as the corresponding engine speed. That is, the sum of the value of gear ratio before gear shift × current transmission output speed N _o × 8 and the value of gear ratio after gear shift × current transmission output speed N _o × 2 is divided by 10. Thus, the engine speed N _eS for determining the start of the gear ratio change (start of the second phase) is obtained.

In the next step 43, the lock-up control command value at the end of the previous lock-up control for up-shift gear shifting and the value obtained by multiplying the command value corresponding to the target slip amount by the safety factor are added. Then, the initial value of the lockup control command value is calculated.

Then, in step 44, it is judged whether or not the current lockup control command value is larger than the initial value of the lockup control command value. If the current lockup control command value is larger, step 45. The lock-up control command value is updated to the above initial value, and if not larger, step 45 is skipped to select the smaller one of the current value and the initial value as the lock-up control command value. Next, at step 46, the upshift shift lockup control end flag is turned off in order to monitor the end of the upshift shift lockup control as described later.

In the next step 29 of FIG.
By the processing of step 1, the end determination of the lockup control during upshift is performed as follows. In other words, first step 5
1, it is determined whether or not the engine speed measurement value N _e is equal to or less than the gear ratio change start determination engine speed N _eS , that is, whether the gear ratio change is started at the instant t ₁ in FIG. To determine. If it is determined that the gear ratio change has started, then in step 52, an upshift shift lockup control end flag for ending the upshift shift lockup control is turned on.

Even when it is determined in step 51 that the measured engine speed N _e is not equal to or less than the gear ratio change start determination engine speed N _eS , the current lockup control command value D is locked during deceleration in step 53. If it is determined that it is less than or equal to the minimum fastening force equivalent command value,
In step 52, the lockup control end flag during upshifting is turned on.

When it is determined in step 51 that the gear ratio change has not started, and when it is determined in step 53 that the lockup control command value D is not equal to or less than the deceleration lockup minimum fastening force equivalent command value. , The control is ended as it is, and the lockup control end flag during upshift is not changed.

In the next step 30 in FIG. 2, the lockup control end flag at the time of upshift gear shifting is set to O.
Whether the lockup control at the time of upshift gear shifting should be ended is determined by whether N or OFF. If it should not be finished yet, at step 31, the engine speed target value N _e0 for lockup control at the time of upshift gear shifting is determined _. The engine speed measurement value N _e is subtracted from this to obtain the engine speed deviation ΔN _e between the two. Then, in step 32, the lockup control command value D is determined by feedback control so that the engine speed deviation ΔN _e becomes 0, that is, the engine speed N _e is brought to the target value N _e0 , and the solenoid 13 is determined. Output to.

If it is determined in step 30 that the lockup control during upshifting should be terminated, step 33
At, the lockup control command value D to the solenoid 13 is maintained at the current value.

According to the control described above, as shown in FIG. 5, the following lock-up control during shifting is performed after the upshift shift command instant t _{1 of the} automatic transmission. That is, lockup control is performed on the torque converter that tries to maintain the engine speed N _e at the target speed N _e0 obtained by adding the predetermined offset amount α to the engine speed at the time of the upshift gear shift command. When the engine speed starts to decrease as shown in FIG. 5 due to the upshift, the lockup of the torque converter is automatically controlled to the open side.

Therefore, even in the upshift shift in the lockup region, the torque converter is put in the slip state, and the upshift shift is not executed while the torque converter is kept in the lockup state. It is possible to prevent shift shock.

By the way, when the torque converter is put into the slip state as described above, the engine speed is maintained at the target speed obtained by adding a predetermined offset amount to the engine speed at the time of the upshift command. Since the slip state is generated in the mode, as a result, the torque converter is slip-controlled with the engine speed that is in the relation of the limit function having the dead zones at the upper and lower limits with respect to the lockup capacity as the control input.
Therefore, the conventional problem that the control logic needs to be switched can be eliminated. In addition, when the engine speed is used as the control input as in the present embodiment, the feedback control is sufficient for the control, and the learning control is not necessarily required. It is possible to achieve the shift shock reducing effect accurately and exactly as intended without any error intervention due to.

Further, when calculating the engine speed at the time of the upshift gearshift command, it is determined by multiplying the transmission output speed at the time of the upshift gearshift command by the gear ratio before gearshift as in step 41 of FIG. Therefore, the following operational effects can be achieved.

That is, as shown by the solid line and the broken line in FIG. 6, even when the shift command is output at the same instant t ₁ depending on the way of operating the throttle for inducing the upshift shift for which the lockup control is to be performed. , The change mode of the engine speed N _e has a difference as indicated by ε. In other words, the change mode of the engine output differs depending on the way of operating the throttle, and the way the lockup control command value D appears is also the throttle operation. It depends on how. Even in such a case, according to the present embodiment, the output speed of the transmission at the time of the upshift gearshift command is multiplied by the gear ratio before shifting to obtain the engine speed at the time of the upshift gearshift command. N _e0 can be made to match the actual situation, and the shift shock reducing effect can be made more reliable.

Then, as in steps 42 and 51, the gear ratio change start determination engine speed N _eS corresponding to a predetermined internal dividing point between the engine speed at the time of the upshift gear shift command and the engine speed after gear shift. At the instant t ₂ in FIG. 5 at which the engine speed N _e has decreased up to, the lockup control of the torque converter for maintaining the engine speed at the target speed N _e0 is terminated, and step 33
Since the lock-up control command value D is held at the value at this time as in the above, it is possible to prevent the lock-up of the torque converter from being completely released, and the re-lock-up after the completion of the gear shift has a large response delay. With this, it is possible to eliminate the adverse effect that the fuel efficiency deteriorates.

If the response delay of the re-lockup after the completion of the shift is not a problem, as shown in FIG. 7, the shift-up lockup control is terminated at the time of shifting to the second phase. _{Alternatively} , even after the shift to the second phase, the lockup control of the torque converter that tries to maintain the engine speed at the target speed N _e0 is continued, and the lockup control command value D is allowed to continue to decrease. good.

Similarly, as shown in FIG. 7, a predetermined offset value β is added to the lockup control command value D ₀ of the torque converter when the engine speed N _e reaches the target speed N _e0. It is recommended to use the lockup control command initial value. In this case, when the torque converter is completely locked up during the upshift, and the lockup capacity is excessively large, as shown by the broken line in the figure, the torque converter is quickly placed in the predetermined slip state. Then, the offset value β for determining the lock-up control command initial value is set to a predetermined time as the time required for the engine speed N _e to converge to the target speed N _e0. Needless to say, it is more preferable if the learning control is performed so that

The initial value of the lockup control command is shown in FIG.
As shown in, the engine speed N_eIs the target speed N
_e0Torque converter lockup trying to keep on
Instant when control is terminated (instantaneous start of gear ratio change) t₂To
Torque converter lock-up control command value specified
Initialize the lockup control command by adding the offset value γ
It can also be a value. Of course, this offset value γ
Like the offset value β described above, the engine speed N _eIs the above
Target speed N_e0The time required to converge to
Needless to say, it is more preferable to control learning so that
not.

In the embodiment shown in FIG. 8, in determining the gear ratio change start instant (second phase start instant) t ₂ , the engine speed at the upshift gear shift command instant t ₁ is determined by the speed measurement accuracy and the rotation speed measurement accuracy. Even when the disturbance is taken into consideration, the time when the gear ratio change start instant (second phase start instant) t ₂ is determined to be when the offset amount δ at which it can be determined that the engine rotation change due to the gear shift has sufficiently started.

[0068] Then, in this embodiment, the t ₂ (initial instant of the second phase) the gear ratio change initial instant, the lock-up control of the torque converter to be maintained engine speed to the target rotational speed N _e0 After that, the lockup control command value D is held at the value at this time. As a result, it is possible to prevent the lockup of the torque converter from being completely released, and the relockup after the end of the gear shift has a large response delay, eliminating the adverse effect of degrading fuel consumption. can do.

FIG. 9 shows the engine speed as the target speed N _e0.
FIG. 9 shows another determination mode of the gear ratio change start instant (second phase start instant) t _{2 at which} the lockup control of the torque converter to be maintained at is ended. In the present embodiment, when the command value D of the lockup control reaches the value D _S corresponding to the slip state of the torque converter capable of preventing shift shock, the gear ratio change start instant (second
It is decided that it is t _{2 when the} phase starts).
Also in this case, the determination can be accurately made.

In each of the above embodiments, the offset amount α to be added to the engine speed at the time of the upshift gear shift command is set to a constant value in calculating the engine speed target value N _e0. If the same is applied even when the torque converter slip amount at the time of the upshift gearshift command is already large, the lockup release becomes too large to meet the demand for gearshift shock prevention, which leads to deterioration of fuel economy and This causes an adverse effect that the subsequent re-lockup has a large response delay.

In order to eliminate this adverse effect, when the torque converter slip amount at the time of the upshift gear shift command is small, the lockup control command value D is increased by increasing the offset amount α of the engine speed as shown by the broken line in FIG. As shown by the broken line in the figure, the offset amount α of the engine speed is reduced as the torque converter slip amount at the time of the upshift gear shift command is increased, and the torque converter slip amount at the time of the upshift gear shift command is set to a certain value or more. 10 is small, the engine speed offset amount α is set to 0 as shown by the solid line in FIG. 10, and the lockup control command value D is given as shown by the solid line in FIG.

In this case, although the torque converter slip amount at the time of the upshift gear shift command is sufficient, the torque converter is not further made to be in the converter tendency, and the excessive slip amount causes deterioration of the fuel consumption, and the gear shift. It is possible to eliminate the above-mentioned adverse effect that the subsequent re-lockup has a large response delay.

[Brief description of drawings]

FIG. 1 is a control system diagram of an automatic transmission including a lock-up control device during shifting according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a lockup control program executed by a transmission controller in the same embodiment.

FIG. 3 is a flowchart showing a subroutine relating to initialization processing related to lockup control during shift in the program.

FIG. 4 is a flowchart showing a subroutine relating to a lockup control end determination process of the same shift.

FIG. 5 is a time chart used for explaining the operation of the lockup control during a shift.

FIG. 6 is a time chart showing time-series changes in engine speed and lock-up control command value during a shift due to a difference in throttle operation.

FIG. 7 is a time chart showing another embodiment of lockup control during shifting.

FIG. 8 is a time chart showing another embodiment of lockup control during shifting.

FIG. 9 is a time chart showing still another embodiment of lockup control during shifting.

FIG. 10 is a time chart showing yet another embodiment of lockup control during shifting.

[Explanation of symbols]

1 engine 2 automatic transmission 3 Torque converter 4 Transmission output shaft 5 accelerator pedal 6 Throttle valve 10 Control valve 11 shift solenoid 12 shift solenoid 13 Lockup solenoid 14 Transmission controller 15 Throttle opening sensor 16 Engine rotation sensor 17 Transmission output rotation sensor

Continuation of the front page (56) Reference JP-A-5-263907 (JP, A) JP-A-4-290675 (JP, A) JP-A-7-167288 (JP, A) JP-A-60-14653 (JP , A) JP-A-2-256962 (JP, A) JP-A-6-74331 (JP, A) JP-A-7-71592 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) (Name) F16H 59/00-63/48

Claims (10)

(57) [Claims] 1. An automatic transmission in which engine rotation is input through a torque converter capable of lock-up, and a predetermined offset amount is added to an engine speed at the time of commanding the upshift while the upshift is being performed by the automatic transmission. Set the target speed obtained by adding
Engine speed starts to drop due to upshifting
And subtract the engine speed from the target speed to obtain
Torque converter lock-up based on the measured rotational speed deviation.
A shift-up lockup control device for an automatic transmission, characterized in that the push-up is controlled to a release side . 2. The engine speed according to claim 1, wherein the engine rotational speed at the time of the upshift gearshift command is determined by multiplying the transmission output rotational speed at the time of the upshift gearshift command by a pre-gear gear ratio. Lockup control device for automatic transmission during shifting. 3. The automatic transmission according to claim 1 or 2, wherein the offset amount of the engine speed is reduced as the torque converter slip amount at the time of an upshift gear shift command increases. Lockup control device. 4. The gear ratio change start determination engine speed determined by subtracting a predetermined offset amount from the engine speed at the time of an upshift gear shift command according to any one of claims 1 to 3, A shift-up lockup control device for an automatic transmission, wherein lockup control of a torque converter for maintaining an engine rotation speed at the target rotation speed is terminated when the rotation speed drops. 5. A predetermined value between an engine speed at the time of an upshift gear shift command and a post-shift engine speed calculated from the engine speed and the post-shift gear ratio according to any one of claims 1 to 3. It is configured to terminate the lockup control of the torque converter that maintains the engine speed at the target speed when the engine speed decreases to the gear ratio change start determination engine speed corresponding to the internal division point of Lockup control device for automatic transmission during gear shifting. 6. The engine speed according to claim 4 or 5, wherein the engine speed at the time of the upshift gearshift command is determined by multiplying the transmission output speed at the time of the upshift gearshift command by a gear ratio before shifting. Lockup control device for automatic transmission during shifting. 7. The engine speed according to claim 1, wherein when the command value of the lockup control becomes a value corresponding to a slip state of a torque converter capable of suppressing shift shock, the engine speed is changed. A lockup control device during shift of an automatic transmission, characterized in that the lockup control of the torque converter for maintaining the target rotation speed is terminated. 8. The lockup control according to claim 1, wherein a predetermined offset value is added to a lockup control command value of the torque converter when the engine speed reaches the target rotation speed. A shift-up lock-up control device for an automatic transmission, which is configured to have a command initial value. 9. The method according to claim 4, wherein
A configuration in which a predetermined offset value is added to the lock-up control command value of the torque converter when the lock-up control of the torque converter for maintaining the engine speed at the target rotation speed is ended to obtain the lock-up control command initial value. A lockup control device for automatic transmission, which is characterized in that 10. The control according to claim 8 or 9, wherein the offset value is learning-controlled so that a time required for the engine speed to converge to the target speed becomes a predetermined time. Lockup control device for automatic transmission during shifting.