JP3458721B2 - Transmission 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 shift control device for an automatic transmission, and more particularly to a shift control device adapted to perform a suitable shift even when a transmission input torque changes due to an accelerator pedal operation during a shift. It is about.

[0002]

2. Description of the Related Art An automatic transmission is, for example, Nissan Motor Co., Ltd.
As described in the issued “RE4R01A Automatic Transmission Maintenance Manual”, the power transmission of the gear transmission system is performed by selectively hydraulically operating (engaging) multiple friction elements for shifting such as clutches and brakes. It is configured to determine a path (gear stage) and switch the friction element to be operated to perform gear shifting to another gear stage. Therefore, the automatic transmission has a speed change that is performed by engaging a certain friction element by increasing the hydraulic fluid pressure and simultaneously releasing another friction element by decreasing the hydraulic fluid pressure, that is, by changing over the friction elements.

In this case, the hydraulic fluid pressure (hereinafter referred to as the engagement side hydraulic fluid) related to the friction element to be engaged (hereinafter referred to as the engagement side friction element) at the time of the gear shift is increased, and the friction element to be released (hereinafter referred to as the engagement side hydraulic fluid pressure). Hereinafter, if a decrease in the hydraulic fluid pressure (hereinafter referred to as the release side frictional element) (hereinafter referred to as the release side hydraulic fluid pressure) does not proceed in a suitable correlation, a large torque pull-in may occur or the automatic transmission This causes deterioration of the shift quality, such as the engine being idle in the preceding stage or being extended during the shift.

Therefore, it is possible to individually control the hydraulic fluid pressures of all the friction elements as well as the engaging side friction element and the releasing side friction element so that the engaging side hydraulic fluid pressure and the releasing side hydraulic fluid pressure are individually controlled. A so-called direct-acting valve type automatic transmission that can be controlled is being considered. In this case, the engagement side hydraulic fluid pressure and the disengagement side hydraulic fluid pressure can be controlled without being affected by the hydraulic fluid pressures of other friction elements. The pressure can be arbitrarily controlled in time series, and the increase and decrease of both hydraulic fluid pressures can be easily promoted with a suitable correlation.

When performing time series control of the engagement side hydraulic fluid pressure and the release side hydraulic fluid pressure, for example, Japanese Patent Laid-Open No.
It is conceivable to change the hydraulic fluid pressures with a predetermined time change gradient according to the transmission input torque by using the technique described in JP-A-0-78118. Also, as its development type,
The gear change period is divided into a plurality of phases, and a suitable time-series change of the engagement side hydraulic fluid pressure and the disengagement side hydraulic fluid pressure is obtained from the transmission input torque at the start of each phase. It is also conceivable to transiently control the hydraulic fluid pressure on the release side.

[0006]

However, in any case,
Targets of the hydraulic fluid pressure on the engagement side and the hydraulic fluid pressure on the release side that were obtained once
The time series changes that are
Even if the transmission input torque changes due to the pedal operation, etc.
The following problems occur because it is used as it is. Figure 9
Stand-by phase, torque phase, inertia
At the start of the shear phase and the shift end phase
And the release side operation based on the transmission input torque at the start.
Hydraulic pressure command value P_OAnd hydraulic fluid pressure command value P on the fastening side_CThe solid line
When shifting as shown in the figure,
Instantaneous t in the bi-phase₁, And the torque phase
Midway t₂Increase throttle opening TVO (with transmission
Output torque T when the force torque increases)_Oof
Instantaneous t on the change time chart₁Transmission output torque
T_OAs is clear from the drop α of
Engine running due to lack of capacity to increase
And the instant t ₂After that, the transmission output torque T_OOriginally
As is clear from the decrease β from the value indicated by the two-dot chain line of
Due to lack of capacity for increasing transmission input torque,
Prolongs during shifting.

According to the first aspect of the present invention, even when there is a change in the transmission input torque due to an accelerator pedal operation or the like during a shift or during each phase, the hydraulic pressure is taken into account in consideration of the torque change. It is an object of the present invention to solve the above problems by proposing a gear change control device capable of transient control.

It is an object of a second aspect of the present invention to propose a shift control device for an automatic transmission, which is effective for the shift control in which the transient control of the hydraulic pressure is defined by its time change gradient. .

According to a third aspect of the present invention, the increase control of the working hydraulic pressure on the engagement side is defined by the time-varying gradient, and this gradient is made to correspond to the transmission input torque in the torque phase.
An object of the present invention is to propose a shift control device for an automatic transmission, which is particularly effective for shift control in which the gradient is made smaller than that in the torque phase during a transition transition from the torque phase to the inertia phase.

It is an object of a fourth aspect of the present invention to propose a shift control device for an automatic transmission, which is effective for the shift control in which the transient control of the hydraulic pressure is defined by its final command value. .

A fifth aspect of the present invention is to propose a shift control device for an automatic transmission, which is suitable when the engine is torque down to prevent shift shock.

[0012]

For these purposes, first, a shift control device for an automatic transmission according to the first aspect of the present invention engages a certain friction element by increasing hydraulic fluid pressure and at the same time operates another friction element. has a shift performed by released by reduction of hydraulic fluid pressure, the release-side hydraulic fluid of the engagement side hydraulic fluid pressure and release to be friction element engagement to be frictional element Saishi to perform gear shifting in response to shift command be controllable to pressure individually, the variable
The hydraulic pressure on the engaging side is pre-set within a predetermined time from the speed command.
Charge and the hydraulic pressure on the release side drops to the initial pressure
In the automatic transmission that allows
One by one check the change of the transmission input torque to, the strange
The transmission is turned on during the period from the speed command until the specified time elapses.
When the force torque changes, immediately release the hydraulic fluid on the release side.
Change only the pressure to a value according to the transmission input torque, and
If there is a change in the transmission input torque between the lapse of the fixed time and the end of the shift , immediately set at least one of the engagement side hydraulic fluid pressure and the release side hydraulic fluid pressure to a value corresponding to the transmission input torque. It is characterized in that it is configured to change to.

In a shift control device for an automatic transmission according to a second aspect of the present invention, in the first aspect of the present invention, the change of the engagement side hydraulic fluid pressure or the release side hydraulic fluid pressure is achieved by changing the time change gradient of the hydraulic fluid pressure. It is characterized by having done.

In a shift control device for an automatic transmission according to a third aspect of the present invention, in the second aspect, the engagement side hydraulic fluid pressure is increased in a torque phase at a gradient according to a transmission input torque.
During the transition from the torque phase to the inertia phase, if the gradient is to be increased with a smaller gradient than the torque phase, there is a change in the transmission input torque while the hydraulic fluid pressure on the engagement side is increased with the smaller gradient. When
It is characterized in that the engaging-side hydraulic fluid pressure is increased with the gradient obtained in the same manner as in the torque phase.

A shift control device for an automatic transmission according to a fourth aspect of the present invention is configured such that, in the first aspect of the invention, the change of the engagement side hydraulic fluid pressure or the release side hydraulic fluid pressure is achieved by changing a final command value of the hydraulic fluid pressure. It is characterized by having done.

A shift control device for an automatic transmission according to a fifth aspect of the present invention is the shift control device for an automatic transmission according to any one of the first aspect through the fourth aspect, when the engine in the preceding stage of the automatic transmission is torque down to prevent shift shock. It is characterized in that the change control of the engagement side working fluid pressure or the release side working fluid pressure is performed by excluding the change of the transmission input torque due to the above.

[0017]

According to the first aspect of the invention, a certain friction element is tightened.
For over switching shift performed when the fastened by an increase in binding side hydraulic fluid pressure to the other friction elements simultaneously is released by reduction in the release-side hydraulic fluid pressure, the fastening between the shift command for a predetermined time
Pre-charge the hydraulic fluid pressure on the side and release the hydraulic fluid on the release side.
Decrease pressure to initial pressure. And involved in this shift
From the gear change command to the end of the gear change, the change in the transmission input torque is checked one by one and until the above specified time has elapsed from the gear change command.
When there is a change in the transmission input torque, corresponding only the disengagement side hydraulic fluid pressure to the transmission input torque immediately value during in
To the end of the shift after the above specified time has elapsed.
When there is a change in the transmission input torque during that period, at least one of the engagement side hydraulic fluid pressure and the release side hydraulic fluid pressure is immediately changed to a value corresponding to the transmission input torque.

According to the configuration of the first invention, the gear shift command
From the precharge time until the above specified time elapses
When there is a change in the transmission input torque, the release side hydraulic fluid pressure
Change to a value according to the transmission input torque, and then change
When there is a change in the speed input torque, the working hydraulic pressure and
At least one of the hydraulic fluid pressure and the hydraulic fluid pressure on the release side
Since the value is changed to a value corresponding to the transmission input torque, the transmission input torque can be changed by operating the accelerator pedal, etc.
This changes in torque every time the
If it is one, only the hydraulic fluid pressure on the release side is
If it comes after, hydraulic pressure of the engaging side and hydraulic fluid of the releasing side
At least one of the pressures always corresponds to the transmission input torque
The hydraulic pressure can be changed, and the transmission
Even if the input torque changes , excess or deficiency of the friction element engagement capacity does not occur, and it is possible to prevent the idling of the engine, the extension during the shift, and the drawing of a large torque.

In the second aspect of the invention, since the change of the engagement side hydraulic fluid pressure or the release side hydraulic fluid pressure in the first aspect of the invention is achieved by the change of the temporal change gradient of the hydraulic fluid pressure, the transient control of the hydraulic fluid pressure is performed. It is possible to provide a shift control device that is effective for the shift control defined by the time change gradient.

In the shift control device according to the third aspect of the invention, the hydraulic pressure on the engagement side is increased with a gradient according to the transmission input torque in the torque phase, and a gradient smaller than the torque phase during the transition from the torque phase to the inertia phase. To raise. Then, if there is a change in the transmission input torque while increasing the engagement-side hydraulic fluid with the small gradient, the engagement-side hydraulic fluid is increased with the gradient obtained in the same manner as in the torque phase. .

According to the third aspect of the invention, since the rising gradient of the working hydraulic pressure on the engagement side is reduced below the gradient corresponding to the transmission input torque in the torque phase during the transition transition from the torque phase to the inertia phase, the inertia is increased. It is possible to smoothly start the phase. Then, when there is a change in the transmission input torque while the engagement-side hydraulic fluid pressure is being increased by the reduced small gradient, the increase gradient of the engagement-side hydraulic fluid pressure is set in the same manner as in the torque phase. Since the obtained large gradient is obtained, the following operational effects can be obtained. In other words, when the transmission input torque changes (increases) as described above, the rising gradient of the working hydraulic pressure on the engaging side is corrected within a small range in response to the change in torque. Since the transition from the torque phase to the inertia phase is in transition, the response delay may have a large effect, and the increase in the engagement capacity of the friction element cannot keep up with the increase in the transmission input torque, which delays the progress of the inertia phase. In the case where the increasing gradient of the hydraulic fluid pressure on the engagement side is set to a large gradient obtained in the same manner as in the torque phase as in the third aspect of the invention, the increase in the engagement capacity of the friction element can be made in time with the increase in the transmission input torque. Therefore, it is possible to avoid the above-mentioned problem that the progress of the inertia phase is delayed.

In the fourth aspect of the invention, since the change of the engagement side hydraulic fluid pressure or the release side hydraulic fluid pressure in the first aspect of the invention is achieved by changing the final command value of the hydraulic fluid pressure, the transient control of the hydraulic fluid pressure is performed. It is possible to provide a shift control device effective for the shift control defined by the final command value.

In the fifth aspect of the present invention, when the engine in the preceding stage of the automatic transmission is torque down to prevent a shift shock, the change in the transmission input torque due to the torque down is excluded and the engagement side hydraulic fluid pressure or release is performed. Change control of side hydraulic pressure. When the engagement-side hydraulic fluid pressure or the release-side hydraulic fluid pressure is changed in response to a change in the transmission input torque when the engine is torque down to prevent shift shock, the gear shift is performed at the start and end of torque reduction. Although a peak torque called “angle” is generated in the machine output torque to deteriorate the shift quality, in the case of the fifth aspect of the invention, the change in the transmission input torque due to the torque down is excluded to exclude the engagement side hydraulic pressure or the release side actuation. Since the change control of the hydraulic pressure is performed, the generation of such peak torque can be avoided.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a power train of a vehicle equipped with a shift control device for an automatic transmission according to an embodiment of the present invention. 1 is an engine, 2 is an automatic transmission, and the power train of the vehicle is configured by tandem connection thereof. To do. The engine 1 has an accelerator pedal 3 operated by a driver.
It is assumed that the output is adjusted by the throttle valve 4 whose opening degree increases from full closing to full opening as the pedal is depressed, and the engine output is input to the automatic transmission 2 via the torque converter T / C.

The automatic transmission 2 directly controls the working hydraulic pressure to be supplied to friction elements such as a hydraulic clutch and a hydraulic brake that determine the power transmission path (shift stage) of the gear transmission system. As a result, the control valve 5 for gear shift control is provided with the hydraulic fluid pressure duty solenoids 6, 7, and 8 as many as the number of the friction elements. These hydraulic fluid pressure duty solenoids 6, 7, and 8 individually control the hydraulic fluid pressures of the corresponding friction elements to selectively engage and actuate the friction elements so that the automatic transmission 2 is operated at a predetermined gear. Allow it to be in the selected state. Then, the automatic transmission shifts and outputs the engine power at a gear ratio according to the selected shift stage.

The drive duty of the duty solenoids 6, 7 and 8 is determined by the controller 11, and this controller outputs a signal from the throttle opening sensor 12 for detecting the opening TVO of the throttle valve 4 and the automatic transmission 2. From the signal from the output rotation sensor 13 that detects the output rotation speed N _o , from the engine rotation sensor 14 that detects the engine rotation speed N _e, and from the input rotation speed sensor 15 that detects the transmission input rotation speed N _i. Input the signal and.

The controller 11 inputs the above-mentioned input information.
2 based on the control program shown in FIG.
Shift control shall be performed as shown below. First step 21
At throttle opening TVO and transmission output rotation
Number N _oRead, and the transmission output speed N_oTo vehicle speed
Calculate VSP.

In the next step 22, shift determination is performed as follows. That is, based on the vehicle speed VSP and the throttle opening TVO, a shift stage suitable for the current driving state is obtained from a planned shift pattern not shown, and the thus-obtained preferable shift stage and the currently selected shift stage are obtained. If and are in agreement, the control is ended without changing the speed as a matter of course. If the current selected shift speed is different from the preferred shift speed, the control proceeds to step 23 to issue a shift command, and the drive duty of the duty solenoids 6, 7, 8 is changed to change the selected shift speed from the selected shift speed. The friction element is released and engaged so that the gear is shifted to a suitable gear.

By the way, in the present embodiment, of the above-mentioned gear shifts, the frictional elements to be engaged from the disengaged state (engagement side frictions) are the gearshifts performed by interchanging the friction elements (here, upshift gearshifts, but downshift gearshifts are also possible). Element) hydraulic fluid command value P _C and hydraulic fluid command value P of the friction element (release side friction element) to be released from the engaged state
_O is determined as in FIG. 7 from FIGS. In the following description, the hydraulic fluid pressure command value P _C for the engagement side friction element will also be simply referred to as the engagement side hydraulic fluid pressure command value P _C, and the hydraulic fluid pressure command value P _O for the disengagement side friction element will simply be referred to as the disengagement side hydraulic fluid command. Also called the value P _O.

In the present embodiment, as shown in FIG. 7, the gear shift period from the gear shift command instant t ₁ to the gear shift end instant t _{13 is} calculated from the gear shift command instant t ₁ to the engagement side hydraulic fluid pressure command value P _C. The first phase until the instant t ₃ when the precharge time Δt _pr to be kept at the charge pressure P _pr elapses, the second phase until the instant t ₈ when the torque phase ends and the inertia phase starts thereafter, and the inertia phase starts. From instant t ₈ to instant t when the inertia phase ends
A third phase of up to _11, divided into the fourth phase from the inertia phase end instant t ₁₁ to the shift end instant t _12, the engagement side hydraulic fluid for each phase pressure command value P _C and disengagement side hydraulic fluid pressure command value Let P _o be controlled.

FIG. 3 shows the control of the first phase.
It is started at the time of gear change command
Connection side hydraulic fluid command value P_CPrecharge pressure P_prWhen set to
Both release hydraulic pressure command value P_OIs the engine speed N
_eAnd transmission input speed N _iFrom the well-known method
Transmission input torque T_iInitial pressure P corresponding to_OITowards low
Let me down. Here, the release side hydraulic fluid command value P_OSlope of decline
Is the precharge time Δ to prevent its undershoot.
t_prMargin time Δt added to_aInstant t_FourSolution to
Discharge side hydraulic fluid command value P_OIs the initial pressure P_OISomething like
And

At the next step 32, the shift command instant t ₁
From the time t _{3 at} which the precharge time Δt _pr elapses, the step 3 is performed until the time t ₃ is reached.
By returning the control to step 31 via step 3 or steps 33 and 34, the engagement side hydraulic fluid command value P _C is maintained at the precharge pressure P _pr and the release side hydraulic fluid command value P _O is initialized. Decrease towards pressure P _OI . In step 33, it is determined whether or not the transmission input torque T _i has changed. If there is a change, then in step 34, for example, the initial pressure P _OI as shown at the instant t ₂ in FIG. The value is changed to a value corresponding to the changed transmission input torque T _i, and the decreasing gradient of the disengagement side hydraulic fluid command value P _O is changed as shown by the two-dot chain line after the instant t ₂ . When it is determined in step 32 that the shift command instant t ₁ has reached the instant t _{3 at} which the precharge time Δt _pr has elapsed, the control advances to step 35, and the second
Start the phase.

The second phase is as shown in FIG. 4, and first, at step 41, the engagement side working hydraulic pressure command value P _C is
For example, the pressure is reduced to the standby pressure P _ST which is set to the pressure equivalent to the return spring of the friction element. In the next step 42, the engagement-side hydraulic fluid command value P _C is increased at a constant standby pressure ramp gradient θ ₁ , and the release-side hydraulic fluid command value P _O is continuously reduced to the initial pressure P _OI. ,
Decrease at release side ramp slope θ ₂ .

Then, in step 43, the transmission enters and leaves the transmission.
Force rotation ratio (N_i/ N_O) Gear ratio g_rIn Figure 7
Indicates the inertia phase start judgment gear ratio g₁Became
Whether or not the moment t when the inertia phase starts₈Leading to
Check whether or not. If not, step
Instantaneous t at 44₃To standby pressure control time Δt_bHas passed
It is checked whether or not it is done, and in step 45, 4 → 5
Gear shifting and transmission input torque T_iIs greater than or equal to a predetermined value
To check. Standby pressure control time Δt_bHas passed
No, again 4 → 5 shift and T_i≧ If not a predetermined value
The control is returned to step 42, and the engagement side hydraulic fluid command value P_C
The standby pressure ramp gradient θ₁And raise
Both release hydraulic pressure command value P _OThe release side run
Slope θ₂Lower with.

In step 44, the standby pressure control time Δt
_When it is determined that it is after the torque phase start instant t _{6 when b} has passed, in step 46, the engagement side hydraulic fluid command value P _C is increased by the torque phase ramp gradient θ ₃ corresponding to the transmission input torque T _i. reduces the release-side hydraulic fluid pressure command value P _O at the torque phase ramp slope theta ₄ as the gear ratio g _r is the torque phase target gear ratio. In step 47, the gear ratio g _r is checked whether whether it is the inertia phase start determination gear ratio g _1, or from the instantaneous t ₃ maximum allowable time for the second phase Delta] t _C has elapsed.

If it is determined in step 45 that the transmission is 4 → 5 and the transmission input torque T _i is equal to or greater than a predetermined value, then in step 48, it is dealt with based on the large transmission input torque T _i . Fastening side hydraulic fluid command value P
_Calculate the torque phase ramp slope θ ₅ of _C and set it to θ ₃
Then, step 46 is executed. in this case,
The decrease gradient θ ₄ of the disengagement side hydraulic fluid command value P _O in step 46 is the same as described above, but the increase gradient θ ₃ of the engagement side hydraulic fluid command value P _C is θ ₅ obtained in step 48.
To 4 when the transmission input torque T _i is large.
→ 5 gear shifts and a changeover upshift gear that is also suitable for 雖 are performed. Explaining a case where the transmission input torque T _i becomes large at the instant t ₅ in FIG. 7 during the 4 → 5 shift, for example, the rising gradient of the engagement side hydraulic fluid command value P _C is θ as shown by the chain double-dashed line. _It switches from ₁ to θ _5, which is steeper than θ ₃ .

[0037] or determines that the gear ratio g _r becomes inertia phase start determination gear ratio g ₁ at step 47, from the instantaneous t ₃ until determining instant t ₈ the maximum allowed time Delta] t _C of the second phase has elapsed In the meantime, after going through step 49,
Alternatively, by returning the control to step 46 through steps 49 and 50, the engagement side working hydraulic pressure command value P _C is continuously increased as described below, and the release side working hydraulic pressure command value P _O is continued as described above. Lower to. In step 49, it is determined whether or not the transmission input torque T _i has changed, and if there is a change, in step 50, for example, as shown in FIG.
As shown at the instant t ₇ , the engagement side hydraulic fluid command value P _C
The torque phase ramp gradient θ ₃ is changed to a gradient according to the changed transmission input torque T _i, and the rising gradient of the engagement side working hydraulic pressure command value P _C is indicated by a two-dot chain line after the instant t _7. Change.

In step 43, the gear ratio g_rIs inertial
Aces start judgment gear ratio g₁If you decide that
In step 51, the third phase is started and the
Gear ratio g_rDecides to start the inertia phase
Ya ratio g₁It is judged that it has become₃To the second festival
Maximum allowable time Δt_CWhen it is determined that
Starts the third phase in step 52
It The third phase started in these steps 51 and 52
5 as shown in FIG.
If the phase begins, first go to step 53
Tightening side hydraulic fluid command value P_CThe standby pressure lamp
Slope θ₁Constant shelf pressure P_C1And keep this shelf pressure
And release side hydraulic fluid command value P_OA small fixed shelf
Pressure P_O1And keep it at this shelf pressure, but step 5
If the third phase starts in 2, first step 5
4, the hydraulic fluid pressure command value P on the engagement side_CThe transmission input
Luk T_iTorque phase gradient θ according to₃Given coefficient to
Inertia phase ramp control multiplied by (less than 1)
Distribution θ ₆And the transmission input torque T_iFixed shelf according to
Pressure P_C1To the gear ratio g based on this shelf pressure._r
Feedback correction to make the desired change.
To the release side hydraulic fluid command value P_OTransmission input torque T_i
Micro constant shelf pressure P according to_O1To maintain this shelf pressure.
To have.

Work on the fastening side in step 53 or 54
Hydraulic pressure command value P_CAnd release side hydraulic fluid command value P_OPerformance of
In step 55, the transmission input torque T is calculated._iNo change
And the gear ratio g in step 56._rIs inertia
Gear ratio g ₂(Gear ratio after shifting)
Whether or not it is instant t₈To the third phase
Allowable maximum time Δt_dInstant t at which it is determined that₁₁Well
Is continuously executed, and the engagement side hydraulic fluid command value P_C
And release side hydraulic fluid command value P_OIs shown by the solid line in FIG.
Change the time series.

By the way, in step 55, the transmission is turned on.
Force torque T_iIf there is a change in
In 59, the hydraulic pressure command value P on the engagement side_CIs the gradient θ₆so
Ascending and transmission input torque T_iWhether or not
Is determined, and if so, in step 60,
Instant t₉As shown by the two-dot chain line below, the transmission input
Luk T_iHydraulic pressure command value P on the fastening side according to_CThe Turkoff
Phase gradient θ₃And recalculate this to
Waze ramp slope θ₆After setting to, control is step 5
By returning to 4, the hydraulic fluid pressure command value P on the engagement side_CFigure 7
Instant t₉Change the time series as shown by the two-dot chain line
To do so. Then, in step 59, the fastening side
Hydraulic pressure command value P_CIs the gradient θ₆Determined not to rise
Or transmission input torque T_iMust increase
If judged, in step 57, the engagement side hydraulic fluid pressure
Command value P_CAbove constant shelf pressure P_C1And release side hydraulic finger
Order P_OAbove constant shelf pressure P_O1Respectively, the instant t in FIG.
_TenAs shown by the two-dot chain line,
Force torque T_iChange the value according to. Step 56
Ya ratio g_rIs the gear ratio g for judging the end of the inertia phase₂(Weird
(Gear ratio after high speed) is reached, or an instant t₈
To the maximum allowable time Δt in the third phase_dHas passed
Instantaneous determination t₁₁When the control reaches step 58, control is performed.
And start the 4th phase as follows.

By the way, as in step 54 above.
The engagement side hydraulic fluid command value P_CInertia Phaser
Pump slope θ₆Is the transmission input torque T_iTorque according to
Phase gradient θ₃And the predetermined coefficient less than 1
If required, smooth start of inertia phase
Can be done. By the way, here is the transmission input
Luk T_iInertia phase ramp gradient when increases
θ₆Is corrected in a small range,
The input torque of the transmission increases when the engagement capacity of the friction element increases.
T_iCan't keep up with the increase. That is, the torque is
Transition period from phase to inertia phase
And the effect of delayed response more than during other periods
Is big. Then, the transmission input torque T_iAgainst the increase of
After the increase of the fastening capacity of the friction element was delayed, it began to decrease.
The engine rotation (gear ratio) increases and inertia
Phase progress is delayed. Therefore, the hydraulic fluid pressure command value on the engagement side
P_CIs the gradient θ₆Transmission input torque T while rising at_iIs increasing
If so (step 59), as in step 60
At the instant t in FIG. ₉As shown in the two-dot chain line below,
Speed input torque T_iHydraulic pressure command value P on the fastening side according to_C
Torque phase gradient θ₃And recalculate this
Nasha phase ramp gradient θ₆Set on the fastening side
Hydraulic pressure command value P_CChange the inertia phase ramp gradient of
Avoid delays in progress of inertia phase
To do. The new transmission input torque T_iAccording to
Hydraulic fluid pressure command value P_CTorque phase gradient θ₃Even strange
It is possible to change gears quickly enough that fast shock is not a problem.
Since it is a gradient, the inertia phase
Even if the pump slope is changed, the shift shock will not increase.
Absent.

The fourth phase is as shown in FIG. 6. First, at step 61, the engagement side working hydraulic pressure command value P _C is increased at the end phase ramp gradient θ ₇ according to the transmission input torque T _i , and The release side hydraulic fluid command value P _O is reduced to 0 at the end phase ramp gradient. In the next step 62, it determines whether or not reached the shift end instant t ₁₃ that the end-phase time Delta] t _e scheduled from the inertia phase end instant t ₁₁ has elapsed, instant t ₁₃
Until step (1) is reached, the control is returned to step 61 via step 63 or steps 63 and 64 so that the engagement side working hydraulic pressure command value P _C is continuously increased at the end phase ramp gradient θ ₇ and is released. 0 hydraulic fluid pressure command value P _O at the end phase ramp slope decreases.

In step 63, the above-mentioned transmission input torque is set.
Ku T_iIs changed, and if there is a change,
0 at step 64, for example instant t in FIG.₁₂After 2
End phase ramp slope θ as seen in the dashed line₇To
Transmission input torque T after change _iChange the value according to
Fastening side hydraulic fluid command value P at step 61_CContribute to the calculation of
It Scheduled after entering the fourth phase in step 62
End phase time Δt_eInstant t₁₃Leading to
If it is determined that there is a lock, control proceeds to step 65
Hydraulic fluid pressure command value P_CIs the maximum line pressure P_LTo
Then, the shift control is ended.

In the above embodiment, when the engine in the preceding stage of the automatic transmission is torque down to prevent shift shock, the transmission input torque (T _i ) as shown in FIG. The engagement-side hydraulic fluid command value P _C and the disengagement-side hydraulic fluid command value P _O are changed in response to the change of the transmission torque. In this case, the transmission output torque T _{O is set} at the start and end of the torque reduction. It was confirmed that peak torques γ and δ called "angles" may occur and deteriorate the shift quality. Therefore, preferably, the transmission input torque change due to the above torque reduction is excluded, and the transmission input torque T _i is shown by a two-dot chain line in FIG. Perform the above-mentioned change control of P _C and the hydraulic fluid pressure command value P _{O on} the release side,
As a result, as is apparent from the waveform of the transmission output torque T _O in FIG. 7B, the gear shift is performed so that the peak torque called “angle” that is generated at the start and end of the torque down is not generated. It is good to prevent the deterioration of quality.

According to the embodiment described above, a change in the transmission input torque is checked step by step during a gear change performed by changing the friction elements, and when there is a change in the input torque (t ₂ in FIG. 7, _{t 5, t 7, t 10} , t 12), the torque
The change timing is a predetermined time Δt _pr + Δ from the shift command.
release-side work as long as the pre-charge period of up to the time of the passage of t _a
Depending on Doeki圧P _O only the changed transmission input torque T _i
The value of the above torque change occurs after that.
If there is engagement side hydraulic fluid command value P _C and release side hydraulic fluid pressure
Transmission input torque after changing at least one of the command values P _O
Since the value is changed to a value according to the torque T _i , the accelerator pedal operation etc. can be performed even after the target time-series change of the engagement side hydraulic fluid pressure command value P _C or the release side hydraulic fluid pressure command value P _O is once obtained.
Whenever the transmission input torque T _i changes due to
If the change is at the precharge time, the hydraulic pressure on the release side
_Tighten only P _O , and if the torque change is subsequent
At least the formation side hydraulic pressure P _C and the release-side hydraulic pressure P _O
One is set to the hydraulic pressure corresponding to the changed transmission input torque T _i.
It can be changed, and the transmission input
There is no excess or deficiency in the friction element engagement capacity due to changes in the torque, and the engine runs dry, is extended during a shift,
It is possible to prevent a large amount of torque from being drawn.

[Brief description of drawings]

FIG. 1 is a system diagram showing a power train of a vehicle including a shift control device for an automatic transmission according to an embodiment of the present invention and a control system thereof.

FIG. 2 is a flowchart showing a main routine of a shift control program to be executed by a controller in the same embodiment.

FIG. 3 is a flow chart showing a control program of an engagement side hydraulic fluid command value and a disengagement side hydraulic fluid command value related to a first phase of an upshift gear shift by changing friction elements.

FIG. 4 is a flow chart showing a control program of an engagement side hydraulic fluid command value and a disengagement side hydraulic fluid command value related to a second phase of the gearshift upshift.

FIG. 5 is a flow chart showing a control program of an engagement side hydraulic fluid command value and a disengagement side hydraulic fluid command value related to a third phase of the gear shift upshift.

FIG. 6 is a flow chart showing a control program of an engagement side hydraulic fluid command value and a disengagement side hydraulic fluid command value related to a fourth phase of the gearshift upshift.

FIG. 7 is a change time chart of the engagement-side hydraulic fluid command value and the disengagement-side hydraulic fluid command value during the gearshift upshift.

FIG. 8 (a) shows the case where the engagement side hydraulic fluid command value control and the release side hydraulic fluid command value control of FIGS. 3 to 6 are executed in the case where torque reduction for gear shift shock countermeasure of the engine is performed. 3B is a time chart showing changes in the transmission output torque of FIG. 3B, ignoring changes in the transmission input torque due to the same torque reduction, and FIG. 7 is a time chart showing a change in transmission output torque when command value control is executed.

FIG. 9 is a change time chart of the engagement-side hydraulic fluid command value and the disengagement-side hydraulic fluid command value in the case where the changeover upshift gear shift is conventionally performed.

[Explanation of symbols]

1 engine 2 automatic transmission 3 accelerator pedal 4 Throttle valve 5 control valves 6 Duty solenoid 7 Duty solenoid 8 duty solenoid 11 Controller 12 Throttle opening sensor 13 Transmission output rotation sensor 14 Engine rotation sensor 15 Transmission input rotation sensor

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-8-296731 (JP, A) JP-A-9-296863 (JP, A) JP-A-9-229177 (JP, A) JP-A-10- 78118 (JP, A) JP 8-270775 (JP, A) JP 10-61757 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16H 59/00-61 / 12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (5)

(57) [Claims] 1. A simultaneously a certain friction element is fastened by an increase in hydraulic fluid pressure, having a shift performed by releasing the other friction element by lowering the hydraulic fluid pressure, a speed change in response to a shift command the release-side hydraulic pressure of the engagement side hydraulic fluid pressure and release to be friction elements of the friction element to be fastened Saishi to do a individually controllable, said clamping during a predetermined time period from said shift command
Pre-charge the hydraulic fluid pressure on the connection side and activate it on the release side
In an automatic transmission that reduces the hydraulic pressure to the initial pressure , changes from the gear change command to the end of gear change are checked step by step, and changes are made between the gear change command and the predetermined time.
When there is a change in the speed input torque, the release side is immediately released.
Only the hydraulic fluid pressure is changed to a value according to the transmission input torque, and when there is a change in the transmission input torque between the passage of the predetermined time and the end of the shift , the engagement is immediately performed. A shift control device for an automatic transmission, characterized in that at least one of a hydraulic fluid pressure on the side and a hydraulic fluid pressure on the release side is configured to be changed to a value according to a transmission input torque. 2. The shift of an automatic transmission according to claim 1, wherein the change of the engagement side hydraulic fluid pressure or the release side hydraulic fluid pressure is achieved by changing a time change gradient of the hydraulic fluid pressure. Control device. 3. The engagement hydraulic fluid pressure according to claim 2, wherein the engagement-side hydraulic pressure is increased with a gradient according to the transmission input torque in the torque phase, and with a gradient smaller than that in the torque phase during a transition from the torque phase to the inertia phase. If the transmission input torque changes while increasing the engagement side hydraulic fluid with the small gradient, the engagement side operation is performed with the gradient obtained in the same manner as in the torque phase. A shift control device for an automatic transmission, wherein the shift control device is configured to increase hydraulic pressure. 4. The shift of an automatic transmission according to claim 1, wherein the change of the engagement side hydraulic fluid pressure or the release side hydraulic fluid pressure is achieved by changing a final command value of the hydraulic fluid pressure. Control device. 5. The engine according to any one of claims 1 to 4, wherein when the engine in the preceding stage of the automatic transmission is torque down to prevent shift shock, a change in the transmission input torque due to the torque down is excluded. A shift control device for an automatic transmission, which is configured to perform change control of the engagement side hydraulic fluid pressure or the release side hydraulic fluid pressure.