JPH0246364A - Operating oil pressure setting method for speed change hydraulic operating clutch - Google Patents

Abstract

PURPOSE:To invariably obtain the desired speed change characteristic by calculating the hydraulic force required for hydraulic operating clutches to obtain the coupling torque of the desired speed change characteristic and subtracting the hydraulic force corresponding to the centrifugal oil pressure from it to set the operating oil pressure at the time of a speed change. CONSTITUTION:A controller 30 presets the coupling torque required for the hydraulic operating clutches 11c-15d of a speed change mechanism 10 coupled at the time of a speed change by a shift lever 45, the hydraulic force required to obtain this coupling force is calculated in the static state of the hydraulic operating clutches. The centrifugal hydraulic distribution generated in the hydraulic operating clutches 11c-15d by the rotation at the time of a speed change is subtracted from this hydraulic force, the operating oil pressure of the hydraulic operating clutches is set, the corresponding operating oil pressure is generated by a hydraulic control valve 20. A constant speed change is invariably controlled, the desired speed change characteristic can be invariably obtained.

Description

Detailed Description of the Invention A. Object of the Invention (Field of Industrial Application) The present invention provides an automatic transmission in which gears are changed by switching a power transmission path by engagement of a hydraulically operated clutch. The present invention relates to a method of setting oil pressure for hydraulically actuated clutch actuation.

(Prior Art) Automatic transmissions for automobiles and the like are configured to automatically change gears depending on the driving condition to obtain desired driving characteristics. For this reason, it is a good practice to have a shift map in which upshift lines and downshift lines are set for each shift based on the relationship between vehicle speed and engine output, and to perform shift control by comparing the driving conditions to this shift map. k) As an example of such speed change control, for example,
There is one disclosed in Japanese Patent No. 189354.

The configuration of an automatic transmission includes a power transmission means (for example, a plurality of gear trains) that constitutes a plurality of power transmission paths, and a plurality of transmission means (for example, a plurality of hydraulic (operating clutch) and a means (for example, a hydraulic control valve) for controlling the operation of this transmission means, and when the driving condition crosses the shift-up line or the shift-down line, the shift-up or shift-down line is activated. Issues a gear change command for downshifting, operates a solenoid valve based on this gear change command, controls the operation of a hydraulic control valve, engages and operates one of the hydraulically operated clutches,
It is common to select a power transmission path using a predetermined gear train to change gears.

When changing gears in this way, the pre-shift stage (the speed stage set by the power transmission path (gear train) that was selected until the shift command was issued) and the post-shift stage (the speed stage selected based on the shift command) Since the speed reduction ratio (gear ratio) is different from the speed set by the transmission path, it is important to control the speed change so that there is no shift shock or shift delay.

Therefore, at the time of shifting, the latch engagement torque capacity is calculated based on the engine torque transmitted from the engine to the hydraulically operated clutch for the second stage of shifting, so as to obtain the desired shifting characteristics without shifting lock or shifting delay, The hydraulic pressure is controlled so that this engagement torque capacity is obtained.

Furthermore, an accumulator is connected to the hydraulically operated clutch,
A valve (orifice control valve, Timing valves, etc.) are often installed to optimize gear shift timing (for example,
0-211152).

(Problem to be Solved by the Invention) In this case, with respect to the clutch engagement torque capacity required during gear shifting, the hydraulic pressure required to obtain this torque capacity is the pressing force of the piston of the hydraulically operated clutch generated by this hydraulic pressure. It was calculated from the coefficient of friction of the friction plate of the hydraulically operated clutch. However, hydraulically operated clutches are often installed on the rotating shaft of a transmission, and in such cases, the hydraulically operated clutch itself is rotated, and within the hydraulic chamber of this clutch, the centrifugal force generated by this rotation is generated. There is a problem in that centrifugal hydraulic pressure is generated. For this reason, even if the hydraulic pressure supplied to the hydraulic clutch is the same, for example, when shifting at high speed,
There is a problem in that the oil pressure in the hydraulic chamber of the hydraulically operated clutch becomes larger than in the case of a shift during low-speed driving, and a shift shock may occur.

In view of these problems, the present invention has been developed to improve the hydraulic pressure of a hydraulically operated clutch so that a constant speed change control can be performed regardless of differences in the rotation of the hydraulically operated clutch, that is, differences in vehicle speed and engine rotation. The purpose is to provide a way to configure the settings.

Structure of the Invention (Means for Solving the Problems) To achieve this object, the method of the present invention includes setting in advance the engagement torque required for the hydraulically operated clutch that is engaged during gear shifting. At the same time, calculate the hydraulic pressure required to obtain this engagement torque with the hydraulically operated clutch in a stationary state, and subtract from this hydraulic pressure the centrifugal hydraulic bone generated inside the hydraulically operated clutch due to rotation during gear shifting. The hydraulic pressure of the operating clutch is set.

(Example) Preferred examples of the present invention will be described below with reference to the drawings.

First, with reference to FIG. 1, the configuration of an automatic transmission in which gear change is controlled using a hydraulically operated clutch that is operated using a hydraulic pressure set by the method of the present invention will be described. In this transmission AT, engine output transmitted from an output shaft 1 of the engine via a torque converter 2 is shifted by a transmission mechanism 10 having a gear train forming a plurality of power transmission paths. is output to. Specifically, the output of the torque converter 2 is output to an input shaft 3, and five sets of gear trains are arranged in parallel with each other between this input shaft 3 and a counter shaft 4 arranged parallel thereto. The output gear train 5 is further arranged between the counter shaft 4 and the output shaft 6.
It is output to the output shaft 6 via a and 5b.

The five gear trains arranged between the input shaft 3 and the counter shaft 4 are a single gear train 11a, flb, a double gear train 12a, 12b, and a triple gear train 13a, 13b.
Quadruple gear trains 14a, 14b and reverse gear train 15
a, 15 b, and 15 c, and each gear train includes a hydraulically operated clutch 11e+ 12c+ 13c+ for transmitting power by the gear train.
14c+15d are arranged. Note that a one-way clutch lid is disposed in the first gear IINm. Therefore, by selectively operating these hydraulically operated clutches, it is possible to select power transmission by any one of the five gear trains to perform a speed change.

The operation control of the five sets of hydraulically operated clutches tic to 15d is carried out from a hydraulic control valve 20 to a hydraulic line 21.
This is done by hydraulic pressure supplied and discharged via a to 21e.

The hydraulic control valve 20 is operated by operating a manual valve 25 connected via a wire 45a to a shift lever 45 operated by the driver, operating two solenoid valves 22 and 23, and operating a linear solenoid valve 56. Ru.

The solenoid valves 22.23 are connected to the signal lines 31a, 3
The linear solenoid valve 56 is turned on and off by an operation signal sent from the controller 30 via 1b.
is activated by a signal sent from the controller 30 via the signal line 31c. A rotation signal from a first rotation sensor 35 that detects the input side rotation speed of the hydraulically operated clutch based on the rotation of the reverse gear 15c is sent to this controller 30 via a signal line 35a, and the rotation signal of the output gear 5b is sent to the controller 30. A rotation signal from the second rotation sensor 32 that detects the output side rotation speed of the hydraulically operated clutch based on the engine throttle 41 is sent via the signal line 32a.
A throttle opening signal from a throttle opening sensor 33 that detects the opening of the engine is sent via a signal line 33a.

Shift control in the transmission configured as described above will be explained.

The speed change control is performed according to a shift range set by the manual valve 25 in the hydraulic control valve 20 in response to the operation of the shift lever 45. These shift ranges include, for example, P, R, N, D, S, and 2 ranges, and in the P and N ranges, all hydraulically operated clutches 110 to 15d are disengaged and the transmission is in a neutral state. In the R range, the reverse hydraulically operated clutch 15d is engaged to set the reverse gear, and in the D, S, and 2 ranges, a shift is performed based on the shift map.

As shown in FIG. 2, this shift map has a shift-up line Lu and a shift-down line Ln as shown in the graph in which the vertical axis shows the throttle opening θTH and the horizontal axis shows the vehicle speed V. When the driving condition determined by the engine throttle opening and vehicle speed crosses the upshift line Lu toward the right side, an upshift is performed, and after the upshift, the downshift line Lo is moved toward the left side. When it crosses the road, it will downshift.

In this example, the shift performed in this manner is classified into five shift modes as described below. Note that each number corresponds to the number in the figure.

■SYU mode: A mode in which an upshift is performed while the power is off (for example, a shift up by releasing the accelerator while driving) ■SYD mode: A mode in which a downshift is performed while the power is on (for example, a kickdown) ■ IPU mode: A mode in which an upshift is performed with the power on (e.g., an upshift during acceleration) ■IPD mode: A mode in which a downshift is performed by manual lever operation, etc. with the power off (e.g., when the shift lever is (downshift that occurs when switching from D range to S range) ■EPD mode: A mode in which the power is off and the vehicle speed decreases before a downshift is performed (for example, when driving, the accelerator pedal is released and the vehicle coasts and the vehicle speed decreases. Note that IPD mode and EPD mode are the same as far as the accelerator state and shift type are concerned, but IPD mode is used when the driver operates the lever expecting a downshift. The EPD mode is a case where automatic downshifts are performed in response to changes in driving conditions. For this reason,
In IPD mode, the tolerance level of shift shock is relatively large, but in EPD mode, this tolerance level is small. Also, depending on the car, for example, the D button and the
There is a button, and there are times when you press the D button to set relaxed shifting characteristics, and press the S button to set sporty shifting characteristics, but when the power is turned off or downshifted in conjunction with the button switching operation, , it is appropriate to assume that the driver did not intend to downshift, and in this case, the EPD mode is set.

Although only one shift-up line and one shift-down line are shown in FIGS. 2 and 2, in reality, a plurality of shift-up lines and a plurality of shift-down lines are set depending on the number of gears.

In the gear shift map shown in FIG.
An actuation signal is output to the solenoid valves/L/bu 22 and 23 via 1b, and the hydraulic control valve 2o is actuated in response to this, and each hydraulically operated clutch lie~15d
Hydraulic pressure is supplied and discharged to perform upshifts or downshifts.

This hydraulic control valve 20 will be explained with reference to FIG. 3.

In this control valve 20, hydraulic oil from the oil sump 7 supplied from the pump 8 is guided to the regulator valve 50 via the line 101.
0 to adjust the line pressure to a predetermined level. This line pressure is led to the manual valve 25 via the line 110, and as the manual valve 25 operates and the various valves in the control valve 20 operate, the line pressure increases to the hydraulically operated clutches llc, 12c, 13C11
It is selectively supplied to clutches 4c and 15d depending on the driving conditions, and the operation of each clutch is controlled.

Here, first, various valves within the control valve 20 will be explained. The check valve 52 is disposed downstream of the regulator valve 50 and prevents the oil pressure of the lubricating oil sent to the lubrication section of the transmission through the line 102 from exceeding a predetermined pressure. The modulator valve 54 reduces the line pressure sent through the line 103 to create a predetermined modulator pressure, and supplies hydraulic fluid at this modulator pressure to the torque converter 2 through the line 104.
The line 1 is supplied to a lock-up clutch control circuit (not shown) for lock-up clutch control.
05 through the first and second solenoid valves 22.2
3 for shift valve operation control.

The manual valve 25 is operated in conjunction with a shift lever 45 operated by the driver.

It is located at any one of six positions R, N, D, S, and 2, and selectively supplies line pressure from line 110 to lines 25a to 25g according to each positive line.

1-2 shift valve 60.2-3 shift valve 62.3
-4 shift valve 64 is manual valve/l/fu 25
The first and second solenoid valves 22.2 when in any of the D, S, 2 positions.
Lines 1゜6a to 106 according to the ON/OFF operation of 3.
The operation of the clutches 11c, 1 for 1st to 4th gears is controlled by the action of modulated pressure supplied through f.
This is a valve that controls supply and discharge of line pressure to 2c+ 13c+ 14c.

Lines 106a and 106b are the first solenoid valve 22
and the line 10 through the orifice 22a.
5, and therefore, when the first solenoid valve 22 is de-energized, the port to the drain side is closed and hydraulic oil with modulated pressure is supplied from the line 105 to the lines 108a and 106b. When the energization is on, the port to the drain side is opened and the pressure in the lines 108a, 108b becomes almost zero. Moreover, the lines 106C to 106f are connected to the second solenoid valve 23
and the line 10 through the orifice 23a.
5, and when the second solenoid valve 23 is de-energized, the port to the drain side is closed and hydraulic oil with modulated pressure is supplied from the line 105 to the lines 106C to 106f, and the above-mentioned When the power is on, the port to the drain side is opened and the line 106
The pressure from c to 106f becomes almost zero.

Here, the line 106a is connected to the right end of the 1-2 shift valve 60, and the line 106b is connected to the 2-3 shift valve 62.
The line 106C is connected to the left end of the 1-2 shift valve 60, the line 106e is connected to the right end of the 3-4 shift valve 84, and the line 108f is connected to the left end of the 2-3 shift valve 62. Note that line 108e,
106f is connected to the second solenoid valve 23 via a manual valve. For this purpose, the first and second solenoid valves 22.

23, each line 108a~
1-2.2-3 if supply and discharge of modulated pressure from line 105 to 108f is controlled.

The operation of the 3-4 shift valves E30, 62.84 can be controlled, thereby selectively applying the line pressure supplied from the line 110 via the manual valve 25 to each hydraulically operated clutch llc, 12c, 13c+14c. It is possible to supply the desired speed and perform the desired speed change.

This control valve 20 has first to fourth orifice control valves 70, 72, 74, 76, and these orifice control valves control the release of the hydraulic pressure in the hydraulic chamber of the front clutch during gear shifting, and the hydraulic pressure of the rear clutch. This is done at the same time as the oil pressure in the room increases. The first orifice control valve 70 controls the hydraulic release timing of the third gear clutch when shifting from third gear to second gear, and the second orifice control valve 72 controls gear shifting from second gear to third gear or from second gear to fourth gear. The hydraulic release timing of the 2nd speed clutch is controlled by the 3rd orifice control valve 74, and the hydraulic release timing of the 4th speed clutch is controlled by the 3rd orifice control valve 74 when shifting from 4th speed to 3rd speed or from 4th speed to 2nd speed. 3 when shifting from 3rd to 4th speed by control valve 76
The hydraulic release timing of the speed clutch is controlled.

Furthermore, each hydraulically operated clutch 11c+12c+13
Accumulators 81, 82 and 83, 84 having pressure receiving chambers communicating with the hydraulic chamber of c+ 14c are provided,
The pressure receiving chamber of each of these accumulators and the piston member 81a
, 82a, 83a+ Lines 121, 122, 123, 124 are connected to the opposing back pressure chambers via 84a.
is connected to linear solenoid valve 56 via lines 120a, 120b and 120.

The linear solenoid valve 56 is
By controlling the current supplied to the linear solenoid 56a, the operating force thereof can be controlled, and the magnitude of the hydraulic pressure (control pressure Ptl()) supplied to the line 120 can be controlled. Therefore, by controlling the current applied to the linear solenoid 56a, it is possible to control the oil pressure in the back pressure chamber of each of the accumulators 81 to 84, thereby freely controlling the oil pressure in the oil pressure chamber of the engagement clutch. be able to.

The clutch brake control valve 78 is disposed on the line from the manual valve 25 to the 1-2 shift valve 60, and is connected to the near solenoid valve 5 described above.
This valve operates in response to the control pressure PTH regulated by 6.

For this reason, each hydraulically operated clutch 11c+ 12c, 13c, 14c via each shift valve 60, 82, 84
The line pressure supplied to the clutch pressure control valve 78 is controlled according to the control pressure PTH applied to the clutch pressure control valve 78. Note that the control pressure Pt□ is controlled to be a pressure corresponding to the engine output except when shifting, and therefore the line pressure for each clutch operation is
The pressure can be as low as possible to obtain the required torque capacity corresponding to the engine output.

In the hydraulic control valve 20 configured as described above, each of the above-mentioned valves is operated as appropriate by the operation of the manual valve 25 by operating the shift lever 45 and the on/off operation of the solenoid valve 22.23, so that each hydraulically operated clutch 11Cs 12 ct 13 c,
14c is selectively controlled to supply line pressure, and automatic gear shifting is performed.

A method of setting the engagement torque capacity of each clutch in this automatic shifting will be described below.

Figure 4 shows the main flow of setting the engagement torque capacity.
In this setting, first, the gear change command is changed from 4th gear to 4th gear in a short time.
Confirmation of interrupt processing when successive times such as 3rd speed → 2nd speed is performed (step S1). Next, it is determined which of the five shift modes shown in FIG. 2 is the type of shift (step S2), and the engagement capacity control timing and engine output restart execution timing are determined for each of these modes. etc. (step S3).

After that, the engagement torque capacity CTQ of each clutch is calculated (step 84), and this is made to correspond to each shift mode, and the clutch engagement torque capacity during gear shifting is calculated based on the timing process (step S3). Make settings.

In order to obtain this engagement torque capacity for each clutch, the control pressure PTH is controlled by the linear solenoid valve 56 to control the back pressure of each accumulator.
Correction of the preload of the spring acting on the piston of each accumulator and correction of the centrifugal oil pressure generated in the clutch hydraulic chamber due to rotation of the clutch (AOF-correction) are performed.

In this way, when the desired engagement torque capacity is set and the control pressure PTH required to obtain this torque capacity is calculated, the required energization current is I8 is searched (step S6), and this current Is is output while being feedback-controlled (step S7).

Clutch engagement torque capacity C in the above main flow
The calculation of TQ (step S4) will be explained with reference to the flowchart of FIG.

In this calculation, first, from the engine output which is preset based on the relationship between the engine speed N6 and the intake negative pressure PB, the engine output corresponding to the engine speed and intake negative pressure at that time (during gear change) is calculated. Read engine output torque ETQ (step 541). Next, during gear shifting, since engine output retardation is performed for the purpose of smooth gear shifting, the engine output is corrected by this retard (step 542). moreover,
Since the engine output is transmitted to the transmission via the torque converter, the torque amplification by the torque converter is also corrected (step 543).

When the engine torque ETQ transmitted to the transmission input shaft is calculated by the above correction, it is determined in step S44 that the current gear shift is in the inertia torque required mode (specifically, IPU and IPD modes). If it is the inertia silk necessary mode, in step 845, the inertia torque I
TQ is calculated.

Inertia torque ITQ is calculated by determining the rate of change in engine speed from the relationship between the amount of change in engine speed caused by this shift and the desired shift time required for this shift.
This refers to the torque capacity required to rotate the input side inertia of the clutch that is engaged during gear shifting in accordance with the above-mentioned rotational change rate. Therefore, this torque ITQ is calculated based on the engine rotational speed at the time of the shift, desired shift characteristics, input side inertia, etc.

In the case of the inertia torque required mode, the inertia torque ITQ calculated in step 845 is added to the engine torque ETQ to obtain the transmission input shaft torque.

Once the transmission input shaft torque is determined in accordance with each shift mode in this way, in step 348, a time-based oil temperature correction (DTQ correction) at the time of oil pressure rise is performed. Even if oil pressure is supplied to the gear shift engagement clutch at the start of gear shifting, there is a time delay until the oil reaches the clutch hydraulic chamber and the clutch starts to engage. This is a correction to shorten the above time delay by increasing the hydraulic pressure supply speed to the clutch.
It is set for a predetermined time from the start of gear shifting.

However, since this time delay varies depending on the difference in oil viscosity due to the difference in oil temperature, the amount of correction thereof differs based on the oil temperature.

Since it is the transmission input shaft torque that is calculated in this way, this is converted into the torque shared by the clutch used for shifting (step 547), and the friction coefficient μ of the clutch plate in this clutch is further calculated. The latch piston pushing force required to obtain this shared torque is calculated from the relationship with the circumferential speed V (step 848).

When the required piston pushing force is calculated in this way, the required clutch oil pressure can be calculated, so the control pressure Pt as the accumulator back pressure to generate this oil pressure can be calculated.
Set □. Note that the required clutch pressure is offset from this control pressure PTH by the preload of the accumulator spring, and furthermore, since the clutch is rotating, hydraulic pressure is generated in the clutch hydraulic chamber due to centrifugal force. The above-mentioned offset correction and centrifugal hydraulic bone correction are shown in step S5 of FIG.

, made in the amendment.

This AOF11 correction will be explained with reference to the flowchart of FIG. 6A.

This correction is performed when the flag FCTQ=1, which is set when the clutch engagement torque capacity CTQ is calculated. Therefore, in step S51, FCTQ=
When it is determined that the correction amount is 1, the correction amount A is determined in step S52. Fn is calculated, and the torque CTQ calculated in the CTQ calculation flow (step S4)
From this correction, flA. The value obtained by subtracting Fn is set as the clutch engagement torque capacity CTQ.

This correction amount A. Fn is a correction for the spring preload in the accumulator and the centrifugal oil pressure, but the spring preload can be understood as a constant value determined for each accumulator, and the centrifugal oil pressure is a correction for each hydraulically operated clutch connected to each accumulator. It can be grasped as a value corresponding to the square of the number of rotations. If the vehicle speed is known, the rotation speed of each hydraulically operated clutch can be determined based on the vehicle speed since the gear ratio is known. The vehicle speed is divided into ranges, and a table is set in which correction amounts corresponding to each hydraulic clutch are set in advance for each divided vehicle speed range. In this table, the average centrifugal oil pressure in each vehicle speed range,
The value is set as the sum of the spring preload correction amounts, so if you know the vehicle speed and the hydraulically operated clutch that is operating, you can calculate the required A. F. The correction amount can be read directly from this table.

The clutch engagement torque capacity CTQ after AoFn correction is set in advance to a minimum value CTQMEN and a maximum value CT Q MAX, and the corrected C
If TQ is smaller than the minimum value CTQMIN, this minimum value CTQMIN is set as the torque capacity CTQ (step 853.54), and the corrected CTQ is the maximum value CTQM.
-X, this maximum value CTQ MAX is set as the torque capacity CTQ (step 855.5
6).

The case where the engagement torque capacity CTQ is set as described above and the gears are changed will be specifically explained using the IPU and IPD modes as examples.

First, in the case of IPU mode, as shown in FIG. 7A, at time 1+, the shift up line Lu is crossed to shift to the current gear S. When a shift command from S to target gear S is issued, the shift solenoid output is changed to target gear S1 at time t2 after waiting for the judgment timer T1 to elapse.

In the case of IPU mode, when the engagement of the current gear clutch (previous gear clutch) is released, the engine rotation changes in the direction in which the input/output rotation of the target gear gear clutch (rear gear clutch) moves away from the synchronization point. Therefore, it is necessary for the rear-stage clutch to start engaging immediately in order to bring the engine rotation closer to the synchronization point.

Therefore, the energizing current I8 of the linear solenoid is set from this point on to a value corresponding to the combined torque of the engine torque ETQ and the inertia torque ITQ. However, even if the shift solenoid is switched, it takes time for the supplied hydraulic pressure to be sent to the rear-stage clutch, and there is a time delay between the engagement of this clutch and the end, so that the input/output rotation speed ratio e of the rear-stage clutch changes from time t2. Until Ll starts to change, that is, until the rear stage clutch starts engaging (t3), the torque DT is larger than the above torque (ETQ+ITQ).
A current value corresponding to Q is set, and the above-mentioned time delay can be shortened. After this, the rotation speed ratio e. At time t7 when L becomes approximately 1.0, the current value I8 is returned to its maximum value.

In this control, when a slip of more than a predetermined amount occurs in the engaged clutch, the engine output is started by a certain amount (
RK), and the input/output rotation speed ratio ecLo of the front stage clutch is a predetermined value e. Time t when R8 or higher
4, the retard RK is started, and furthermore, the input/output rotational speed ratio ec of the clutch for the second stage of shifting is the determination value e. R,J
From the time t5 when the value exceeds 8, the judgment value e eRLI+! A retard RU larger than the above-mentioned retard RK is set until the time when the retard RK is exceeded, so that engagement of the hydraulically operated clutch is smoothly completed.

In the case of the IPD mode, as shown in FIG. 7B, at time t1, the shift down line Lo is crossed to the current gear S. When a shift command from to target gear S is issued, the shift solenoid output is immediately changed to target gear S. Even in the case of IPD mode, when the engagement of the current gear clutch (previous gear clutch) is released, the engine rotation changes in the direction in which the input/output rotation of the target gear gear clutch (rear gear clutch) moves away from the synchronization point. Therefore, it is necessary to start engaging the rear-stage clutch immediately.

Therefore, from this point in time t1, the energizing current Is of the linear solenoid is equal to the engine torque ETQ and the inertia torque IT.
It is set to a value corresponding to the combined torque of Q. however,
In this case as well, in order to reduce the time delay from switching the shift solenoid to the start of engagement of the rear clutch, the input/output rotation speed ratio e of the rear clutch is changed from time t. The above torque (ETQ
+ ITQ) A current value corresponding to a larger torque DTQ is set. After this, the rotation speed ratio e. At time t8 when I becomes approximately 1.0, the current value I3 is returned to its maximum value.

In this control as well, when a slip of more than a predetermined amount occurs in the engaged clutch, the engine output is started by a certain amount (
RK), and the input/output rotation speed ratio of the front stage clutch is e. LO is a predetermined value e. The time t when it becomes below RL
The retard RK is started from 3, and the input/output rotational speed ratio e of the clutch for the second stage of gear change. Ll is the judgment value e. R.D.
From the time t5 when the value falls below S, the judgment value e. A retard RD larger than the above-mentioned retard RK is set until the time when the retard becomes less than R□.

In this example, an example was shown in which the clutch pressure that determines the clutch engagement torque capacity is controlled using the control pressure PTH that acts as back pressure of the accumulator, but the present invention is not limited to this, and for example, the clutch pressure The pressure may be directly controlled by a linear solenoid valve, in which case A shown in FIG. , there is no need to correct the offset of the accumulator spring in the correction. Further, the load roll pressure may be generated by a solenoid valve whose duty ratio is controlled, instead of by the linear solenoid valve.

C9 As described in detail, according to the present invention, the engagement torque required for the hydraulically operated clutch that is engaged during gear shifting is set in advance, and the hydraulically operated clutch is in a stationary state. Calculate the hydraulic pressure required to obtain this engagement torque, and set the working hydraulic pressure of the hydraulically operated clutch by subtracting from this hydraulic pressure the centrifugal hydraulic pressure generated inside the hydraulically operated clutch due to rotation during gear shifting. Therefore, regardless of differences in the rotation of the hydraulically operated clutch during gear shifting, that is, differences in vehicle speed or engine rotation, constant gear shifting control can be performed at all times, and desired shifting characteristics can always be obtained. can.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an automatic transmission in which a hydraulically operated clutch is actuated using the hydraulic pressure set by the method of the present invention to perform gear change control, and Fig. 2 is a schematic diagram showing an automatic transmission that is used to determine a shift in the transmission. Graph showing the shift map, Figure 3 is a hydraulic circuit diagram for the above gear shift control, Figures 4 to 6 are
The figure is a flowchart showing a method for setting the engagement torque capacity and hydraulic pressure according to the present invention, and FIGS. 7A and 7B are graphs showing contents of shift control corresponding to shift modes. 2...Torque converter 10...Transmission mechanism 20.
... Hydraulic control valve 22.23 ... Shift solenoid valve 25 ... Manual valve 32.35 ... Rotation sensor 56 ... Linear solenoid valve

Claims (1)

[Scope of Claims] 1) A method for setting hydraulic pressure to be supplied to a hydraulically operated clutch that is engaged when a shift command is issued in an automatic transmission, the method comprising: obtaining desired shift characteristics during shifting; Setting an engagement torque required for the hydraulically operated clutch, and
The hydraulic pressure required for the hydraulically operated clutch to obtain this engagement torque when the hydraulically operated clutch is stationary is calculated, and from this hydraulic pressure, the centrifugal hydraulic pressure generated inside the hydraulically operated clutch due to rotation during gear shifting is calculated. A method for setting the working oil pressure of a hydraulically actuated clutch for shifting, characterized in that the actuating oil pressure of the hydraulically actuated clutch is set by reducing the hydraulic pressure corresponding to the above.