JPH0712211A - Shift control device for automatic transmission - Google Patents

Abstract

(57) [Summary] [Purpose] In the case of performing feedback control of the friction element operating pressure using the correction rate represented by the ratio of the target value of the transmission input rotation change rate and the actual measurement value, a sufficient shift shock from the first time A control mode is proposed in which a reducing effect is obtained. [Structure] The first time of control is step 84, in which the initial feedback correction rate α _i at the time of the previous shift is set as the feedback correction rate α and this α _i is used. After that, the feedback correction rate α obtained in step 88 is used. Is used as it is, the working pressure target value Po is corrected in step 85, and the working pressure P of the friction element is calculated. Therefore, when the operating pressure P of the friction element is calculated, the operating pressure can be determined from the first time in such a manner that the shift shock is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear shift control device for appropriately controlling hydraulic fluid pressure of a friction element that is operated during gear shifting of an automatic transmission.

[0002]

2. Description of the Related Art The hydraulic fluid pressure of a friction element during shifting is
If this is too high, frictional element engagement shock, so-called shift shock, occurs, while if it is too low, the gear shift is extended and so-called shift delay occurs. Therefore, it is necessary to properly control the hydraulic fluid pressure of the friction element, but as the conventional hydraulic fluid pressure control for the countermeasure against the shift shock, for example, Japanese Patent Laid-Open No. 1-2615 can be used.
The one described in Japanese Patent No. 59 was generally used.

That is, the output rotation speed of the torque converter during shifting, that is, the transmission input rotation speed Ni is monitored, and the working fluid of the friction element is focused so as to be focused as desired during shifting, for example, as shown in FIG. 5 (a). The pressure was feedback-controlled.

[0004]

However, in such a conventional shift control device, there is a restriction on the calculation capability of the shift control controller and the responsiveness of the solenoid valve, so that the first control is executed at the start of calculation. It is when 50 msec to 100 msec has passed from the instant. To add to FIG. 5A, assuming that the above feedback control is started at the instant t ₁ when the inertia phase is started, the transmission input rotation speed Ni is read from this and the first feedback control is performed based on this. What is actually performed is the instant t ₂ after the response delay described above from the instant t _{1 at which the} inertia phase starts.

For this reason, conventionally, from the instant t ₁ to the instant t ₂
Until then, the feedback control disabled state continues, and the transient change state of the friction element working hydraulic pressure during this period is determined by the shift control hydraulic circuit that is hardware.

Therefore, in the past, strict tuning of hardware was indispensable as a countermeasure against shift shock, and the number of man-hours for development and manufacturing of an automatic transmission was large, and the cost was high in this respect.

[0007] Further, even with such tuning,
Note that there is no guarantee that sufficient shift shock processing will be performed.
Depending on the situation, as shown in FIG.₁ A moment
Time t ₂ During the period when feedback control cannot
Peak torque is generated as seen in the waveform of force torque To
And I was inevitable that a shift shock would occur.

The present invention proposes a hydraulic fluid pressure control system for a friction element that can sufficiently reduce the shift shock during the period in which the feedback control cannot be performed, so that the shift shock can be reliably reduced, and at the same time, the hardware can be reduced. The purpose is to eliminate the cost disadvantage by eliminating the need for strict tuning of wear.

[0009]

To this end, the speed change control device of the present invention, as shown in the concept of FIG. 1, is capable of selecting a predetermined shift speed by selective hydraulic operation of a friction element, and the operation of the friction element. In the automatic transmission equipped with the pressure adjusting means for performing feedback control using the feedback correction rate represented by the ratio of the target value of the transmission input rotation change rate and the actual measurement value during the speed change of the hydraulic pressure, the The initial correction rate storage means for updating and storing the first feedback correction rate, and the feedback correction rate for the first time updated by the initial correction rate storage means as the feedback correction rate at the first time of the feedback control. An initial correction rate command means for commanding the pressure means is provided.

[0010]

The automatic transmission selects a predetermined shift speed by selectively hydraulically operating the friction element. The pressure-adjusting means during the gear-shift control feedback-controls the hydraulic pressure of the friction element based on a feedback correction rate represented by a ratio between a target value and a measured value of the transmission input rotation change rate.

By the way, the initial correction rate storage means updates and stores the first feedback correction rate each time such a shift is performed, and the initial correction rate command means uses the above-mentioned feedback correction rate as the feedback correction rate at the first time of the feedback control. The initial feedback correction rate at the time of the previous shift updated by the initial correction rate storage means is instructed to the pressure adjusting means.

Therefore, the hydraulic fluid pressure of the friction element can be controlled from the initial period in which feedback control cannot be performed in such a manner that the shift shock is sufficiently reduced, and the shift shock is reliably reduced. By eliminating the need for strict tuning of the hardware and reducing the man-hours for development and manufacturing of the automatic transmission, the cost disadvantage of the conventional device can be eliminated.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. 2 and 3 are a gear shift mechanism and a shift hydraulic circuit of an automatic transmission equipped with a shift control device according to an embodiment of the present invention.

First, to explain the gear shift mechanism of FIG. 2,
It has input / output shafts I and O coaxially, and three planetary gear sets 3, 4, and 5 are coaxially interposed between these input / output shafts. The planetary gear set 3 is a simple planetary gear set including a sun gear 3S, a ring gear 3R, a plurality of pinions 3P meshed with these gears, and a carrier 3C that rotatably supports the pinions, and the planetary gear sets 4 and 5 are also respectively Sun gear 4S, 5
S, ring gears 4R, 5R, a plurality of pinions 4P, 5
A simple planetary gear set including P and carriers 4C and 5C.

As a friction element that determines the power transmission paths of the above-mentioned three planetary gear sets, that is, the gears, the following 2 will be described.
Provide 1 clutch and 3 brakes. Of the two clutches, the low clutch L / C is the sun gear 4S, 5
It is assumed that the rotating member serving as the connection of S is properly connected to the input shaft I, and the high clutch H / C is appropriately connected to the carrier 4C to the input shaft I. The input shaft I is attached to the sun gear 3S and the output shaft O is attached to the carrier 5C.

Of the three brakes, the band brake B / B is to appropriately fix the ring gear 3R to the transmission case 6, and the second brake S / B is a rotating member which is a combination of the carrier 3C and the ring gear 4R. Is fixed to the transmission case 6 as appropriate, and the reverse brake R / B is configured such that the rotating member that connects the carrier 4C and the ring gear 5R is appropriately fixed to the transmission case 6. The carrier 4C and the ring gear 5
The rotating member that becomes the R coupling is further correlated with the transmission case 6 so that the rotation in the direction opposite to the input rotation is blocked by the low one way clutch L / OWC.

The above-mentioned gear speed change mechanism selectively moves the friction elements in accordance with the logical table shown in the figure to perform the engaging operation (the circle indicates the operation), so that the forward drive speed is changed in the forward automatic speed change travel (D) range. The first to fifth speeds can be selected, and the reverse gear can be selected in the reverse travel (R) range. In addition, N and P in this table represent the neutral range and the parking range in which power transmission is not performed.

Next, the shift control hydraulic circuit shown in FIG. 3 for controlling the shift of the gear shift mechanism in accordance with the engagement logic of FIG. 2 will be described.

Reference numeral 11 denotes an oil pump, which converts the hydraulic oil from this to a predetermined line pressure and outputs it to the line pressure circuit 12.
On the other hand, the line pressure of the circuit 12 is reduced to a constant converter pressure by the torque converter regulator valve 13 and output to the circuit 14. The converter pressure of the circuit 14 is controlled by the lock-up control valve 15 in the flow direction toward the torque converter T / C, while it is supplied to the lubrication section 17 via the oil cooler 16, and further the electromagnetic switching lubrication control valve 18 is supplied.
It is supplied to the lubrication parts 19 and 20 under the flow rate control by.

The torque converter T / C is inserted between the input shaft I of the gear transmission mechanism shown in FIG. 2 and an engine (not shown) to transmit engine power to the input shaft I. The torque converter T / C has an AP and a release chamber RL, and when the lock-up control valve 15 is in the state shown in the drawing, the converter pressure of the circuit 14 flows in a direction from the former apply chamber AP to the latter release chamber RL.
Is in a lock-up state in which its input and output elements are directly connected, and the converter pressure in the circuit 14 is changed from the release chamber RL to the apply chamber A when the lock-up control valve 15 is in a state opposite to that shown in the drawing.
When flowing in the reverse direction toward P, the torque converter T / C is assumed to be in the converter state where the direct connection between its input and output elements is released.

On the other hand, the line pressure of the circuit 12 is reduced to a constant pilot pressure by the pilot valve 21 and then the circuit 22.
Is output to the lockup control valve 1
5 and the electromagnetic proportional lockup gain control valve 23. The lock-up gain control valve 23 regulates the pilot pressure of the circuit 22 and applies it to the lock-up control valve 15 as appropriate, and thereby the lock-up control valve 15 is added.
Shall cause the above-mentioned state changes.

The line pressure of the circuit 12 further reaches a manual valve 30, which is manually operated by the driver to a range corresponding to a desired traveling mode. Here, as the range, a parking (P) range, a reverse running (R) range, a neutral (N) range, a forward automatic running (D) range, and a second speed engine brake (2) range are set. .

The manual valve 30 is 30 in the P and N ranges.
-P, 30-N ports are connected, all output circuits of the D range circuit 31, the 2 range circuit 32, and the R range circuit 33 are drained, and the R range is in the 30-R port connection state. , D range circuit 31 and 2 range circuit 3
2 is drained, the line pressure of the circuit 12 is supplied to the R range circuit 33, the port is connected to 30-D in the D range, and the line pressure of the circuit 12 is supplied to the D range circuit 31. The range circuit 32 and the R range circuit 33 are drained, the ports 30-2 are connected in two ranges, the line pressure of the circuit 12 is supplied to the D range circuit 31 and the 2 range circuit 32, and the R range circuit 3
Drain 3

The circuit 31 includes a duty solenoid valve 34.
Is inserted into the circuit 35, the circuit 37 in which the duty solenoid valve 36 is inserted, and the circuit 39 in which the duty solenoid valve 38 is inserted. Each of the duty solenoid valves has a friction element operating hydraulic pressure that increases in proportion to the drive duty. Shall be output. The circuit 35 passes through the shuttle valve 40 and the circuit 41 together with the circuit 32, and the low clutch L / C.
It is connected to the 1st speed apply chamber 1A. The low clutch L / C has a 5th speed release chamber 5R in addition to the 1st speed apply chamber 1A and is engaged when pressure is supplied to the 1st speed apply chamber 1A. When the pressure is also supplied to the fifth-speed release chamber 5R while being supplied, the low clutch L / C is released due to the pressure receiving area of both.

The circuits 37 and 38 are connected to an electromagnetic switching type 2-4 shift valve 42, which is turned off.
In the normal state, the circuits 43 and 44 are connected to the circuit 37,
Although the circuit 45 is connected to the circuit 39 and the circuit 45 is drained, the circuits 43 and 44 are respectively drained and the circuit 45 is connected to the circuit 39 in the ON state.

On the one hand, the circuit 43 connects to the fifth clutch release chamber 5R of the low clutch L / C via an orifice 46, and on the other hand to the high clutch H / C together with the circuit 44 via an orifice 47 and a shuttle valve 48. In addition, the shuttle valve 49 is connected to the 5th speed / reverse apply chamber 5RA of the band brake B / B. The circuit 45 is also connected to the second brake S / B.

The band brake B / B has the third speed apply chambers 3A and 2 in addition to the fifth speed / reverse apply chamber 5RA.
There are 24th and 4th speed release chambers, and each apply chamber 5R
It is assumed that the fastening operation is performed by the pressure supply to A and 3A, and the engagement is released by the pressure supply to the release chamber 24R in place of these. The third speed apply chamber 3A is connected to a circuit 51 extending from the line pressure circuit 12 and having a duty solenoid valve 50 inserted therein.
It is assumed that 0 outputs the friction element hydraulic fluid pressure that increases in proportion to the drive duty. Further, the second and fourth speed release chambers 24R are connected to the circuit 52 branched from the circuit 39.

The retraction circuit 33 is the NR accumulator valve 5
While connecting to the reverse brake R / B via 3,
The band brake B / B is connected to the fifth speed / reverse apply chamber 5RA via the orifice 54 and the shuttle valve 49.

Capacity control of oil pump 11, ON / OFF control of lubrication control valve 18, lock-up gain control valve 2
3 and duty solenoid valves 34, 36, 38, 5
0 duty control, 2-4 shift valve 42 ON, OF
The F control is executed by the controller 60, and therefore the controller 60 inputs the input information 61 such as the selection range, the engine throttle opening degree, the vehicle speed, etc., which are necessary for the normal shift control, and particularly the shift according to the present invention. For control, a signal from an input rotation sensor 62 that detects the transmission input rotation speed Ni is input.

The shifting operation of the above embodiment will be described below. The P (N) range driver wishes to park or stop, and the manual valve 30
This valve drains all of the output circuits 31, 32, and 33 while the controller is in the P range or the N range, and the controller 60 sets the drive duty of the duty solenoid valve 50 to 0% to set the pressure of the circuit 51 to 0. I have to. Therefore, all the friction elements are deactivated, and as is clear from the logic table in FIG. 2, the gear transmission mechanism in the figure is in a neutral state in which power transmission is not performed, and a parking / stopping state can be obtained as desired. it can.

When the D range driver desires forward automatic shifting, the manual valve 3
While the 0 is in the D range, this valve outputs the line pressure of the circuit 12 only to the circuit 31.

(First speed) Here, the controller 60 is
When it is determined from the input information 61 that the first speed should be selected, the drive duty of the duty solenoid valve 34 is set to a predetermined value, and the corresponding operating pressure is passed through the circuit 35, the shuttle valve 40, and the circuit 41 to the chamber of the low clutch L / C. Supply to 1A.

Therefore, the controller 60 sets the drive duty of the duty solenoid valves 36, 38, 50 to 0%.
Then, the pressure of the circuits 37, 39, 51 is set to 0, and 2-4
The shift valve 42 is off. Therefore, no pressure is supplied to the chamber 5R of the low clutch L / C, and of course no pressure is supplied to the high clutch H / C, the second brake S / B, or the band brake B / B. Further, since the manual valve 30 drains the circuit 33, no pressure is supplied to the reverse brake R / B.

Therefore, only the low clutch L / C is engaged, and as is clear from the logical table of FIG. 2, the gear transmission mechanism of FIG. 2 has the low one-way clutch L / OW.
In combination with the engagement of C, the first speed can be selected and the power transmission at this gear can be performed.

By the way, when the selection of the first speed is accompanied by the switching of the manual valve 30 from the N range to the D range, the controller 60 sets the drive duty of the duty solenoid valve 34 during the shift to the value shown in FIG. The low clutch L / C is gradually increased by the control described later.
The fastening shock, that is, the N → D select shock is reduced.

After the shift is completed, the driving duty ratio of the duty solenoid valve 34 is set to 100% to set the operating pressure of the low clutch L / C to the maximum value equal to the line pressure to prevent the clutch from slipping. .

(Second speed) When the controller 60 determines from the input information 61 that the second speed should be selected, the drive duty of the duty solenoid valve 34 is maintained at 100% and the low clutch L / C is engaged. As it is, the 2-4 shift valve 42 is turned ON, the circuits 43 and 44 are drained, respectively, and the circuit 45 is connected to the circuit 39. At the same time, the drive duty of the duty solenoid valve 38 is gradually increased by the control described later with reference to FIG. Circuit 39, 45
The second brake S / B is gradually engaged due to the increase in the internal pressure.

The fastening of the second brake S / B is as follows.
In combination with maintaining the engaged state of the low clutch L / C, FIG.
As is clear from the logical table of FIG. 5, the gear transmission mechanism shown in the figure can be switched to the second speed selection state, and the automatic transmission can be upshifted from the first speed to the second speed. Further, at the time of this shift, the drive duty of the duty solenoid valve 38 is gradually increased to gradually increase the pressure in the circuits 39 and 45, and thus the second brake S / B is gradually engaged, so that shift shock is reduced. be able to.

(Third speed) When the controller 60 determines from the input information 61 that the third speed should be selected, the drive duty of the duty solenoid valve 34 is maintained at 100% and the low clutch L / C is in the engaged state. As it is, again 2-4
While maintaining the ON state of the shift valve 42, the drive duty of the duty solenoid valve 38 is set to 0% and the second brake S / B is switched to the release state, and at the same time, the drive duty of the duty solenoid valve 50 is changed as described later with reference to FIG. The band brake B / B is gradually tightened by increasing the pressure from the circuit 51 to the apply chamber 3A of the band brake B / B by control.

This switching from the second brake S / B to the band brake B / B is combined with the holding of the engaged state of the low clutch L / C, as is apparent from the logical table of FIG. Switch the gear shift mechanism to the third speed selection state,
The automatic transmission can be upshifted from the second speed to the third speed. At the time of this shift, the drive duty of the duty solenoid valve 50 is gradually increased so that the circuit 51
The pressure inside is gradually increased, so the band brake B /
Since B is gradually engaged, shift shock can be reduced.

(Fourth speed) When the controller 60 determines from the input information 61 that the fourth speed should be selected, the drive duty of the duty solenoid valve 34 is maintained at 100% and the low clutch L / C is engaged. As it is, the drive duty of the duty solenoid valve 50 is set to 0% and the band brake B / B is switched to the release state, at the same time, the 2-4 shift valve 42 is switched to the OFF state, and the drive duty of the duty solenoid valve 38 is changed as shown in FIG. Therefore, the high clutch H / C is gradually engaged by increasing the pressure from the circuits 39 and 44 to the high clutch H / C by a control as will be described later.

This switching from the band brake B / B to the high clutch H / C is combined with the holding of the engaged state of the low clutch L / C, as is clear from the logical table of FIG. The gear shift mechanism can be switched to the fourth speed selection state, and the automatic transmission can be upshifted from the third speed to the fourth speed. At the time of this shift, the drive duty of the duty solenoid valve 38 is gradually increased so that the circuits 39, 4
The pressure in 4 is gradually increased, so that the high clutch H /
Since C is gradually engaged, shift shock can be reduced.

(Fifth speed) When the controller 60 determines from the input information 61 that the fifth speed should be selected, the above-mentioned fourth speed is selected.
In the speed selection state, the drive duty of the duty solenoid valve 38 is set to 0%, and the drive duty of the duty solenoid valve 36 is gradually increased by the control as described later with reference to FIG. A drive duty of 0% of the duty solenoid valve 38 eliminates the pressure from the circuits 39 and 44 to the high clutch H / C, but an increase in the drive duty of the duty solenoid valve 36 causes the high clutch H / C from the circuits 37 and 43 and the orifice 47. Since the operating pressure is newly supplied to C, the high clutch H / C maintains the engaged state.

On the other hand, the pressures of the circuits 37 and 43 are supplied to the release chamber 5R of the low clutch L / C via the orifice 46 and the band brake B via the shuttle valve 49.
Reach 5RA of the apply chamber of / B. Here, the low clutch L / C continues to be supplied with pressure to the apply chamber 1A, but the pressure receiving area in the release chamber 5R is larger than the pressure receiving area in the apply chamber 1A.
It is released by the pressure of. In addition, band brake B / B
Are fastened by the pressure reaching the apply chamber 5RA.

Therefore, the low clutch L / C is released and the band brake B / B is engaged while the high clutch H / C is maintained in the engaged state. The change to / B coupled with maintaining the engaged state of the high clutch H / C,
As is clear from the logical table of FIG. 2, the gear transmission mechanism of the same figure is switched to the fifth speed selection state, and the automatic transmission is changed from the fourth speed to the fifth speed.
It is possible to shift upshift to high speed. During this shift, the drive duty of the duty solenoid valve 36 is gradually increased to gradually increase the pressure in the circuits 37 and 43, and thus the band brake B / B is gradually engaged, so that shift shock is reduced. be able to.

Shift Control According to the Present Invention By the way, at the time of each of the above-mentioned upshift shifts, the controller 60 executes the control program of FIG. 4 to determine the operating pressure of the friction element to be engaged during the shift. The individual duty solenoid valves are controlled as follows.

This control program is shown in FIG. 5 when each upshift (inertia phase) is actually started.
Starting at the instant t ₁ of (a) and (b), first, at step 81, the operating pressure target value Po of the friction element is calculated. In this calculation, as usual, the operating pressure for changing the input speed of the transmission at a speed suitable for reducing the shift shock that has been set in advance is obtained, and this is set as the operating pressure target value Po.

In the next step 82, the initial feedback correction rate α for each type of shift stored as described later.
Look up a table in _i . And step 83
The following control is executed until it is determined that the shift is completed in. That is, in the first control, the initial feedback correction rate α _i is set as the feedback correction rate α in step 84. In step 85, the operating pressure target value Po of the friction element is
Is calculated by the feedback correction rate α to calculate the operating pressure P (P = Po × α) of the friction element, and the operating pressure of the friction element is controlled by the corresponding duty solenoid valve so that this value P is obtained in step 86. .

In step 87, the time change rate (d / dt) Ni of the transmission input rotation speed Ni detected by the sensor 62 is obtained, and in step 88, this input rotation change rate and preset shift shock reduction are suitable. For example, in FIG.
From the target input rotation change rate (d / dt) Nim corresponding to the change over time of the transmission input rotation speed Ni as shown in (b),
The feedback correction factor α is α = (d / dt) Nim /
(D / dt) Calculated by Ni.

In step 89, it is checked whether or not it is the first control, and only in the case of the first control, in step 90, the calculated correction rate α in step 88 is set as the initial feedback correction rate α _i , which corresponds to the type of shift. It is stored in the address of the memory and used as the material for the table lookup in step 82.

After such processing, control is returned to step 85.
Calculates the operating pressure P of the friction element (P = Po × α)
However, the first correction factor α is step 8
By the execution of step 4,
Initial feedback correction factor is α _iIs used and then
The feedback correction factor α calculated in step 88 is used.
To be

According to this control, the previous shift is performed as shown in FIG.
As described above for (a), the instant t ₁ , T₂ Between
Even if a gear shift shock occurs because the feedback control cannot be performed,
Instantaneous t when shifting the same kind of₁ , T₂ The space and the leopard,
Initial feedback correction factor for the first shift of the previous shift
α_iSince the control using is executed, as shown in FIG.
As you can see from the torque waveform
Can be reduced.

After the instant t ₂ , the feedback control of the friction element operating pressure is executed as usual using the correction factor α calculated every moment, and the transmission input rotation speed is reduced by the preset shift shock reduction. Top preferred Figure 5
By controlling the operating pressure of the friction element so that the speed changes at the speeds shown in (a) and (b), the shift shock can be reduced during this time.

When the R range driver desires backward running and sets the manual valve 30 to the R range, the circuits 31 and 32 are drained, and the line pressure of the circuit 12 is output only to the circuit 33. Circuits 31, 32
Drains are low clutch L / C, high clutch H / C,
And the second brake S / B is released to release them, and the line pressure to the circuit 33 is set to the NR accumulator valve 5
After reaching the reverse brake R / B via 3 and engaging and actuating the reverse brake R / B, the reverse brake R / B is reached through the N-R accumulator valve 53 and the orifice 54 to the apply chamber 5RA of the band brake B / B and the band brake B / B is engaged. Activate.

When the reverse brake R / B and the band brake B / B are engaged, as is apparent from the logic table of FIG. 2, the gear transmission mechanism of FIG.
The vehicle can be run backwards. At this time, N-
The R accumulator valve 53 can gradually increase the engagement pressure of the reverse brake R / B and the band brake B / B, and reduce these engagement shocks, that is, NR select shocks.

[0056]

As described above, the shift control device of the present invention is defined by claim 1.
In the feedback control of the hydraulic fluid pressure of the friction element based on the feedback correction rate represented by the ratio between the target value of the transmission input rotation change rate and the actual measurement value, as described in (1). The feedback correction rate of the first feedback control is stored and updated, and the feedback correction rate at the first time of the feedback control is configured to use the updated and stored initial feedback correction rate at the time of the previous shift. Since the hydraulic fluid pressure of the friction element is controlled in the period during which the gear shift is disabled, the gear shift shock can be sufficiently reduced, and the gear shift shock can be reliably reduced. Therefore, it is necessary to rigorously tune the hardware. The cost disadvantage can be eliminated by reducing the development man-hours and manufacturing man-hours of the automatic transmission. That.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a shift control device according to the present invention.

FIG. 2 is a schematic diagram of a gear shift mechanism of an automatic transmission equipped with a shift control device according to an embodiment of the present invention.

FIG. 3 is a shift control hydraulic circuit diagram of the same automatic transmission.

4 is a flowchart showing a shift control program executed by the controller in FIG.

5 is a change time chart of the input rotational speed and the output torque exhibited by the automatic transmission under the control of FIG.

[Explanation of symbols]

 I Input shaft O Output shaft L / C Low clutch H / C High clutch B / B Band brake S / B Second brake R / B Reverse brake 3 Planetary gear set 4 Planetary gear set 5 Planetary gear set 11 Oil pump 13 Torque converter regulator Valve 15 Lockup control valve 18 Lubrication control valve 21 Pilot valve 23 Lockup gain control valve 30 Manual valve 34 Duty solenoid valve 36 Duty solenoid valve 38 Duty solenoid valve 42 2-4 Shift valve 50 Duty solenoid valve 53 NR accumulator valve 60 Controller 62 Input rotation sensor

Claims (1)

[Claims] 1. A predetermined gear stage can be selected by selectively hydraulically operating a friction element, and the hydraulic fluid pressure of the friction element is represented by a ratio between a target value and a measured value of a transmission input rotation change rate during gear shifting. In an automatic transmission equipped with a pressure adjusting means for performing feedback control using the feedback correction factor, an initial correction factor storing means for updating and storing the first feedback correction factor at each shift, and the feedback control An initial transmission rate commanding means for instructing the pressure adjusting means the first time feedback correction rate updated by the initial correction rate storage means as the feedback correction rate at the first time is provided. Shift control device.