JPH0379857A - Line pressure controller for automatic transmission - Google Patents

Abstract

PURPOSE:To restrain a speed change shock by conducting a learning control of a line pressure so that a speed change time may approach a target value at a range in which a happening such as a momentary rise and sudden decrease of a turbine revolution number and a sudden decrease of a torque at the time of the transition of speed change does not occur. CONSTITUTION:A line pressure learning correcting means 81 conducts a learning correction of a line pressure regulated by means of a line pressure regulating means 77 so that the speed change time of an automatic transmission detected by means of a speed change time detecting means 80 may become a target value. Also, when a happening such as a momentary rise and a sudden decrease of an automatic transmission input side revolution number, and a sudden decrease of a drive torque is detected by means of an abnormal time detecting means 82, a line pressure correcting means 83 in preference to the line pressure learning correcting means 81 corrects the line pressure so that the above happenings may not occur. Thus, an occurrence of a speed change shock is effectively restrained and also a slip of a friction element can be adequately restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a line pressure control device that corrects and controls line pressure in order to obtain appropriate gear changes in an automatic transmission.

(Prior Art) Conventionally, line pressure control devices for automatic transmissions have been used, for example, as disclosed in Japanese Patent Publication No. 63-3183, to measure the time of a gear shift performed by the operation of a friction element, and to calculate the shift time. Learning control is performed on the line pressure supplied to the friction "Ik" so that the speed change of the coal block becomes especially 11 standard, thereby keeping the speed change time constant and suppressing the speed change shock.
There are known devices in which the slippage of the friction elements is moderately suppressed.

(Problems to be Solved by the Invention) By the way, even in the case where the line pressure is learned and controlled to adjust the shift time to a constant value directly to the target as described above, there are the following disadvantages.

In other words, there are two ways to change gears in an automatic transmission: one is to change gears between a friction element and a one-way clutch, and the other is to change gears between friction elements. In the latter case, engine torque is transferred naturally and smoothly using a one-way clutch, but in the latter case, there is a difference in switching timing between the friction elements, and this causes a difference between the friction element on the releasing side and the friction element on the engaging side. Changes in torque capacity (that is, transmitted torque) during shift transitions do not respond well, and as a result, firstly, even in a situation where the torque capacity of the friction element on the disengagement side has decreased sufficiently, the torque capacity of the friction element on the engagement side decreases. When it is small, the turbine rotational speed temporarily increases and the rotational speed rises. Second, when the torque capacity of the friction element on the engagement side during torque transfer is excessive, the turbine rotational speed decreases quickly, causing a pullback in the turbine rotational speed. Thirdly, if the torque capacity of the friction element on the disengagement side is large and the torque capacity of the friction element on the engagement side increases even though it is still firmly engaged, both friction elements will be in the engaged state. Engine torque suddenly decreases, causing torque pull. If the above-mentioned turbine rotational speed rises, pulls in, or torque pulls in, an unreasonable burden is placed on the engagement of the friction elements, even if the shift time is controlled to a constant target value as in the conventional method. This results in the drawback that the durability and reliability of the friction element are reduced.

The present invention has been made in view of the above, and its purpose is to provide priority to constant control of the shift time in the event of a shift abnormality such as an increase in the turbine rotation speed as described above. The purpose is to prevent this phenomenon.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, priority is given to line pressure learning control for controlling the shift time to a target value.
The line pressure will be corrected and controlled to optimize the timing of torque transfer between the friction elements during a shift transition.

In other words, the specific angle q determining means of the present invention, as shown in FIG. A shift time detection means 80 detects the shift time, and a line pressure learning sleeve controls the line pressure adjustment means 77 to learn and correct the line pressure so that the shift time detected by the shift time detection means 80 reaches a target value. abnormality detection means for detecting a temporary increase or sudden drop in the input side rotation speed or a sudden drop in the driving torque based on the input end rotation speed of the automatic transmission during gear shifting; 82 and
When the abnormality detection means 82 detects a temporary increase or sudden drop in the input end rotational speed of the automatic transmission, or a sudden drop in the driving torque, the line pressure learning correction means 81 The configuration is such that a line pressure correction means 83 is provided which preferentially corrects the line pressure so that the above phenomenon does not occur.

(Function) With the above configuration, in the present invention, during a shift transition,
When the turbine rotational speed temporarily increases, it is determined that the torque capacity of the friction element on the engagement side is small and the turbine rotational speed is rising, and the line pressure correction means 83
Since the line pressure can be corrected to a higher value, the torque capacity of the friction element on the engagement side at the time of torque transfer is increased, and the turbine rotational speed is effectively prevented from rising during the next gear change.

On the other hand, if the turbine rotation speed suddenly decreases, it is determined that the torque capacity of the friction element on the engagement side during torque transfer is excessive and the turbine rotation speed is being pulled in, and the line pressure can be corrected to a lower level. Therefore, the torque capacity of the friction element on the engagement side at the time of torque transfer becomes small, and the pull-in of the turbine rotational speed during the next gear change is prevented.

Furthermore, when torque is pulled in, the friction element on the side that releases the angle is in a closed state, so the change in the turbine rotational speed is small. Therefore, if the degree of change in the turbine rotational speed is small, it can be determined that torque is being pulled in, and the line pressure can be corrected to lower, thereby reducing the torque capacity of the friction element on the disengagement side at an early stage during a shift transition. As a result, torque is smoothly transferred to the friction element on the engagement side.

When the above line pressure correction is performed, the direction of the line pressure correction may be the same as the line pressure learning control direction, but the above-mentioned turbine rotational speed rise, pull-in, or torque pull-in Since the line pressure learning control is performed so that the shift time is set to the target value only in situations where no phenomenon occurs, H)l during the shift will converge as close to the target value as possible within the range where the above phenomenon does not occur.

(Effects of the Invention) As explained above, according to the line pressure control device for an automatic transmission of the present invention, the speed change is 0 within a range where the turbine rotational speed rises, pulls in, or torque pulls in during a shift transition. Since the line pressure is learned and controlled so that the distance approaches the target value, it is possible to suppress the shift shock to an H effect while preventing the occurrence of the above phenomenon, and it is also possible to moderately suppress the slippage of the friction elements, so that the line pressure is always properly controlled. It is possible to change gears.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings from FIG. 2 onwards.

FIG. 2 shows the configuration of the automatic transmission 10. 1 dynamic transmission 10 shown in the figure has four forward speeds and one reverse speed, 15 is an engine output shaft, 16 is a pump 16a connected to the engine output shaft 15, a stator 16b, and a turbine 16.
A torque converter comprising a stator 16 and c.
b is provided so as to be fixable to the case 18 via a one-way clutch 17 for preventing the stator 16b from rotating in the opposite direction to the turbine 16c. Further, 20 is a speed change gear device connected to a converter output shaft 16d connected to the turbine 16c of the torque converter 16.

The speed change gear device 20 has a Ravigneau type planetary gear mechanism 22 inside, and the planetary gear mechanism 22 includes a small diameter sun gear 23 and a large diameter sun gear 24 arranged in the front and rear, and a short pinion gear 25 that meshes with the small diameter sun gear 23. and,
The above large diameter sun gear 24 and short pinion gear 25
It consists of a long pinion gear 26 that meshes with the long pinion gear 26, and a ring gear 27 that meshes with the long pinion gear 26. The output shaft of the torque converter 6 is connected to the small diameter sun gear 23 via a forward clutch 30 disposed behind it and a first one-way clutch 31 that is connected in series to the clutch 30 and prevents reverse drive of the converter output shaft 16d. 1.6d. A coast clutch 32 is connected in parallel to the yarn path in which the forward clutch 30 and the first one-way clutch 31 are connected in series. The large-diameter sun gear 24 also includes a 2-4 brake 33 and a 2-4 brake 33 arranged diagonally rearward thereof.
4 Reverse clutch 34 located behind the brake 33
The output shaft 16d of the torque converter 16 is connected to the output shaft 16d of the torque converter 16 via. The long pinion gear 26 also includes a low and reverse brake 36 that identifies the long pinion gear 26 via its rear carrier 35, and a second brake that allows the long pinion gear 26 to rotate in the same direction as the engine output shaft]5. The one-way clutch 37 is connected in parallel, and the front carrier 38 is connected in parallel with the one-way clutch 37.
It is connected to the output shaft 16d of the torque converter 16 via a four-way clutch 39.

Further, the ring gear 27 is connected to an output gear 40 disposed in front of the ring gear 27. In the figure, 42 is a lock-up clutch that directly connects the engine output shaft 15 and the converter output shaft 16d, and 43 is an oil pump driven by the engine output shaft 15 via an intermediate dreg 44.

In the above configuration, the operating states of each clutch and brake at each gear stage are shown in the following table.

Next, a hydraulic circuit for operating each friction element of the automatic transmission 10 is shown in FIG. In the figure, 70 is a pressure valve that regulates the oil pressure from an oil pump 71 driven by the engine 1 to generate line pressure, and 72 is a manual valve that is linked to a select lever manually operated by the driver. Although not shown, a friction element of the automatic transmission 10 is connected to the manual valve 71 through a plurality of shift valves so that the pressure can be supplied and discharged.

The pressure regulating valve 70 has a spool 70a and a spring 70b that biases the spool 70a to the right in the figure with a biasing force SP, and the hydraulic pressure P from the ura pump 71 acts on the right end of the spool 70a in the figure. However, line pressure 2 is applied to the left oil chamber 70c.
Control pressure for J adjustment is applied. Then, the spool 70a is minutely moved left and right depending on the magnitude relationship between the total pressure T (target line pressure) of this control pressure and the urging force Sp (target line pressure) and the oil pressure P.
The line pressure passage 72 and the drain passage 73 are adjusted for communication/blocking, and the oil pressure P is adjusted to a total of 31 pressures T (11 standard line pressure).

As a configuration for generating control pressure, the oil chamber 70c
An oil passage 75 is connected to the oil passage 75, and hydraulic pressure obtained by reducing the discharge pressure of the oil pump 71 with a pressure reducing valve 76 acts on the oil passage 75. is connected, and the line pressure is adjusted in magnitude by adjusting the opening ratio of the oil passage 75 to the oil tank and adjusting the control pressure by the ON-OFF operation of the duty solenoid valve SQL. It constitutes line pressure adjustment means 77.

Next, to explain the line pressure control shown in FIG. 4, it is checked in step S1 whether or not the gear is being shifted, and if the determination is No, the line pressure is controlled outside of gear shifting, that is, the line pressure is adjusted to the throttle opening. and the pressure value is controlled according to the turbine rotation speed. On the other hand, if the determination in step s1 is YES, in step S3 a line pressure control routine during gear shifting shown in FIG. 5 is executed, and further, in step S4 it is checked whether an upshift is to be performed. If the determination in step S4 is YES, then in step S5 the line pressure control routine based on learning during the shift 0 shown in FIG. 9 is carried out, and if the determination in step S4 is NO.
In the case of (downshift), the line pressure is corrected by learning the revving speed. Correct pressure.

Next, line pressure control during gear shifting in FIG. 5 will be explained. In this routine, first, it is checked in step SAI whether or not there is an upshift. When shifting up, the throttle opening degree is read in step SA,-, and the line positive P crossing is determined in step SA3 according to the gear position before and after the shift and the throttle opening degree.

In this way, the line pressure at the time of upshifting can be adjusted appropriately by 1 to 2 J. In other words, the shock at the time of upshifting is related to the engine output and gear position depending on the throttle opening, and in particular, the shared torque and capacity of the friction elements that are switched during gear shifting differ depending on the gear position. If the line pressure is set regardless of the 2! J cannot be adjusted. Therefore, in this embodiment, the line pressure at the time of upshifting is shown in Fig. 6 (a).
), values corresponding to the line pressure for each combination of gears before and after the shift are stored as a map in the memory in the control unit, and the line pressure is determined from this map. Therefore, conventionally, the line pressure is set to a relatively high value that can prevent all friction elements from slipping, as shown by the two-dot chain line in Fig. 6(b), but in this embodiment, As shown by the solid line, the line pressure is set to a value that is lower than before and differs depending on the gear position.

Further, if the determination in step SAI is No, that is, a downshift, it is checked in step SA4 whether or not it is a downshift from 3rd gear to 2nd gear, and if the determination is YES, steps SA, 5 to 5 are performed. Calculate the line pressure by sA3, and if No, line pressure control outside the shift (4th
Proceed to step S, =) in the figure. The reason why this is done is that at 1 o'clock when downshifting from 3rd gear to 2nd gear, the 2-4 brake 33 is engaged at the same time as the 3-4 clutch 39 is released, so M adjustment of the engagement timing is required. However, during other downshifts, only the 3-4 clutch 39 or 2-4 brake 33 is released, and 2J adjustment of the engagement timing by line pressure is not required.

The processing when downshifting from 3rd gear to 2nd gear is as follows:
In step A5, the turbine rotation speed is read, and in step SA
In step 6, a baseline pressure P9o is determined according to the turbine rotation speed. In other words, when downshifting from 3rd gear to 2nd gear, when the turbine rotation speed reaches the appropriate rotation speed by releasing the three 3-4 clutches, the 2-4 brake 33
Since the timing at which the engine is engaged differs depending on the turbine rotation speed, the baseline pressure P9o corresponding to the turbine rotation speed is stored as a map in the memory in the control unit, as shown in Fig. 7, and the base line pressure P9o is The line pressure PQo is determined.

Following step SA6, step SA7. In SA8,
The line pressure is corrected according to the throttle opening change rate calculated from multiple throttle opening detection values.In other words, as the throttle opening change rate becomes faster, the engine speed (turbine speed) increases faster. Therefore, in order to speed up the engagement timing, a correction coefficient Ca is determined according to the throttle opening change speed as shown in FIG.
By multiplying this by the baseline pressure PQo, the final line pressure P intersection is determined.

Following step SA3 or step SA, step SA9 determines the duty ratio of duty 7T [valve SOL, step 5A10 sets the solenoid drive frequency, and step SA I+ sets the solenoid valve O.
N time is calculated, and the duty solenoid valve SQL is driven in step 5A12.

Next, line pressure correction by learning the shift time shown in FIG. 9 will be explained. This routine corrects the line pressure PQ obtained in step 5A3 in FIG. Since the shift time is related to the engagement speed of the friction element, the line pressure is corrected depending on the shift speed r+near. In this routine, the turbine rotation speed is read in step SBI, and the rate of change ΔN of the turbine rotation speed is calculated in step S11□. And step SB3
Compare this rate of change ΔN with the relatively large set value A,
If ΔN, ≧A, it is determined that the turbine rotational speed is in a dry blowing state, and in step 8.34, the correction coefficient CIIN is searched from the correction coefficient map shown in FIG. 10, and the rate of change ΔNT of the turbine rotational speed is determined. The larger the value, the larger the value, and step SB.
5, the baseline pressure P is multiplied by the above correction coefficient CAN to increase the line pressure.

On the other hand, in step SR), if it is not a dry blowing state where ΔNT<A, step Si1. , wait for the set time t to elapse,
After this time t has elapsed, in step SB7, the rate of change ΔN of the turbine rotation speed is compared with a negative value and a relatively large value -B,
If ΔNT≦-B, the pulling state of the turbine rotational speed is determined by 'I'11, and in step SB8, the correction coefficient CAMI is searched based on the correction coefficient map shown in FIG. 11, and the rate of change ΔNT of the turbine rotational speed is determined. The larger the negative value, the smaller the value, and in step SB5, the baseline pressure P is corrected by multiplying it by the above correction coefficient CAN1 to lower the line pressure.

If ΔN, r > -B in step SB7, then step Sll determines whether the rate of change ΔNT of the turbine rotational speed is within a predetermined range near zero (-C≦ΔN7≦D). If it is within this range, it is determined that the torque is being pulled in, and in step 5RIQ, the correction coefficient CAN2 is searched based on the correction coefficient map shown in FIG. Within this predetermined range (-C≦
ΔN7≦D), the larger the value, the smaller the value, and step S
At B'i, the baseline pressure P is adjusted by the above correction coefficient CAN2.
Make a multiplication correction to lower the line pressure.

Then, if the determination in step SB9 is NO, that is, if there is no idling or pull-in of the turbine rotation speed, and if there is no pull-in of torque, learning control of the line pressure is performed in steps 5B11 and thereafter to bring the shift time to the target value. That's it.

That is, after calculating the target turbine rotation speed after shifting from the turbine rotation speed before shifting in step 5B11, in step SBI At step 5B13, it is determined whether or not the shift is completed based on whether or not the condition that the rate of change of the turbine rotational speed - is equal to or less than a predetermined shift is satisfied, and when it is determined that the full speed is completed, the shift time T is calculated in step 5B13. .

After that, in step S[lI4, the shift time T and target value T of the branch are determined. After calculating the deviation ΔT from the
Then, the correction coefficient C in FIG.
Calculate t. In other words, when the deviation △T is near zero, C
L-1, but as shown in Fig. 13, the shift time T
If 1 is short and the deviation ΔT is ffi value, set Ct<1 to reduce the line pressure, and if the shift time T2 is long and the deviation ΔT is
If is a positive value, set CL>1 to make the line positive Toso large.

Then, in step 5BI6, the line pressure P obtained above is
is corrected to P - p xc (by the above correction coefficient Ct), and this corrected line pressure P is used for the next control.

Next, the line pressure correction by learning the blow-up rotation speed in step S6 of FIG. 4 will be explained based on FIG. 15.

Read the turbine rotation speed in step SEI, and step S
In E2, the target turbine rotation speed N after the shift is determined by the turbine rotation speed before the shift. Calculate.

Thereafter, in step SE3, the rate of change in the turbine rotational speed is calculated, and in step SE4, it is determined whether the rate of change in the turbine rotational speed has become less than a predetermined value corresponding to the end of the shift, that is, point X in FIG. +XI + . The difference between the two is calculated as the number of upturning rotations ΔN (=Ns No).

Thereafter, in step SET, a correction coefficient C is determined based on the correction coefficient map shown in FIG.
n is calculated to be 1.0 or more as the revving rotational speed ΔN is a positive value, and to be 1.0 or less as the revving rotational speed ΔN is a negative value. Then, in step SE8, the baseline pressure P
By multiplying and compensating by the above correction coefficient Cn and using this compensated line pressure P for control during the next downshift, the turbine rotation speed shown by the dashed line and dashed line in FIG. Prevents blow-up and withdrawal.

Therefore, steps S, . . . in the control flow of FIG.

With SnI2, the speed change u,' from the start to the end of the speed change is caused by the operation of a friction element operated by line pressure.
A shift time detection means 80 configured to detect j fL'l T is configured. Further, in steps S and 14 to SR+6 of the same control flow, the shift time detection means 30
The gear shift time T detected at I is the target value T. Calculate the correction coefficient Ct so that
In particular, it constitutes a line pressure learning correction means 81 that performs learning control on the duty electromagnetic valve 5QL.

In addition, steps SRI to S[13, SB of the same control flow
6. S87. Shift I1.7 by S B9
Turbine rotation speed of the automatic transmission 10 at (input side l1
An abnormality detecting means 82 is configured to detect a temporary increase in the turbine rotation speed, a sudden drop, or a sudden decrease in the driving torque based on the F1 rotation speed. Further, in steps 5B41 to 5B81 Sa +o of the same control flow, when the abnormality detecting means 82 detects a temporary increase in the turbine rotation speed of the automatic transmission 10, a correction coefficient CAN (C1N≧1) is set. When the line pressure is increased and a sudden drop in the turbine rotation speed is detected, the line pressure is lowered by setting the correction coefficient CI (CANI ≦1), and when a sudden drop in the drive torque is detected,
? The line pressure learning correction means 8 sets the +iiE coefficient CAN2 (CAN2≦1) to lower the line pressure.
1, a line pressure correction means 83 is configured to correct the line pressure so that the above-mentioned phenomenon does not occur.

Therefore, in the above embodiment, as can be seen from the table above, during a 2-3 upshift, the 2-4 brake 33 releases and the three 3-4 clutches engage, causing a gap between these two friction elements. Torque is transferred.

In that case, the rate of change ΔNT of the turbine rotation speed is ΔN1≧A
When the turbine rotational speed rises as shown by the broken line in FIG. 18, the correction coefficient CAN is set to CaN>1, and the line pressure P becomes Pm p
It is corrected more highly than the calculation formula.

As a result, as shown in Fig. 19, the torque capacity of the 3-4 clutch 39 (friction element on the engagement side) increases during torque transfer during the next gear shift, so that this torque capacity and the engine torque are approximately equal. In response to the problem of uniformity, it is possible to prevent the turbine lr rotation speed from racing during the next gear change.

Conversely, when the rate of change of the turbine rotation speed is ΔNT≦−B, the 18th
As shown by the dashed line in the figure, when the pulling of the turbine +ii1 rotation occurs, the third coefficient CAN1 of the sleeve 11 is Ca
Since the line pressure P is set to Nt<1 and the line pressure P is corrected low, the torque capacity of the friction element on the engagement side at the next torque transfer will be reduced, thus preventing the turbine rotation speed from pulling in at the next gear shift. be done.

Furthermore, as shown by the two-dot chain line in Fig. 18, when the rate of change of the turbine rotational speed is 10≦ΔN, ≦D and a small torque pull-in occurs, the correction coefficient C^N2 becomes CAN2 <
Since it is set to 1, line jfP is corrected low. As a result, the torque capacity of the 2-4 brake 33 (friction element on the disengaging side) decreases quickly at the shift transient of 0.1 f, and the engagement operation of the friction element on the engagement side is slowed down. Therefore, there is no longer a situation where both friction elements are firmly engaged at the same time, and the torque is pulled in at the same time.

Then, after preventing the above-mentioned turbine rotational speed blow-up, pull-in, and torque pull-in phenomena, the shift time T is set to the target value T by learning control. The line pressure is corrected and controlled so as to approach the target value as much as possible without causing the above phenomenon.

Therefore, it is possible to obtain an appropriate shift state by suppressing shift shock and slipping of the friction elements while preventing the turbine rotational speed from rising or falling during a shift transition, and the torque from pulling down.

In the above embodiment, the present invention is applied to the case of upshifting, but it goes without saying that it can be similarly applied to the case of downshifting.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. Figures 2 to 19 show embodiments of the present invention, Figure 2 is a skeleton diagram of an automatic transmission, Figure 3 is a surface pressure circuit diagram for adjusting line pressure, and Figures 4 and 5. is a flow chart diagram showing line pressure control, Figure 6 is a diagram showing line pressure characteristics according to the gear stage and throttle opening during upshifting, and Figure 7 is a diagram showing line pressure characteristics according to the turbine rotation speed during 3→2 downshifting. A diagram showing a line pressure map, FIG. 8 a diagram showing correction coefficient characteristics of line pressure with respect to throttle opening change rate, and FIG. 9 a flowchart diagram showing learning control of line pressure to bring the shift time to the target value. Figure 10 is a diagram showing the line pressure correction coefficient characteristics when the turbine rotation speed rises, Figure 11 is a diagram showing the line pressure correction coefficient characteristics when the turbine rotation speed is pulled in, and Figure 12 is a diagram showing the torque pull-in. Fig. 13 is an explanatory diagram of how the turbine rotation speed changes during a shift transition, and Fig. 14 shows the correction coefficient characteristics according to the deviation of the shift time from the target value. Figure 15 is a flowchart showing the line pressure learning correction according to the blow-up rotation speed, Fig. 16 is an explanatory diagram showing how the turbine rotation speed blows up at the end of the shift, and Fig. 17 is a flowchart showing the line pressure learning correction according to the blow-up rotation speed. A diagram showing the correction coefficient characteristics of the line pressure according to the deviation of the upstream rotational speed from the target value, Fig. 18 is an explanatory diagram of how the turbine rotational speed changes during a shift transition, and Fig. 19 is 2-3.
FIG. 4 is an explanatory diagram of changes in the torque capacity of the 2-4 brake band and the torque capacity of the 3-4 clutch during gear shifting. IO: Automatic transmission, SQL: Duty solenoid valve, 77: Line pressure adjustment means, 80: Shift visit detection means, 81: Line pressure learning correction means, 82:
Abnormality detection means, 83...Line pressure correction means.

Claims (1)

[Claims] (1) A line pressure adjusting means that can arbitrarily adjust line pressure, a shifting time detecting means that detects the time of shifting performed by the operation of a friction element operated by line pressure, and a shifting detected by the shifting time detecting means. and a line pressure learning correction means for learning and correcting the line pressure by controlling the line pressure adjustment means so that the time becomes the target value, and the input side rotation speed is adjusted according to the input side rotation speed of the automatic transmission during gear shifting. Abnormality detection means for detecting a temporary rise, sudden drop, or sudden drop in drive torque, and a temporary rise or sudden fall in the input side rotation speed of the automatic transmission by the abnormality detection means. , or line pressure correction means for correcting the line pressure so that the above-mentioned phenomenon does not occur, taking priority over the above-mentioned line pressure learning correction means when a phenomenon of a sudden drop in driving torque is detected. Automatic transmission line pressure control device.