JP2539007B2 - Line pressure control device for automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a line pressure control device for an automatic transmission, and more particularly to a device for appropriately controlling the line pressure during gear shifting.

(Prior Art) An automatic transmission has various friction elements (clutch, brake, etc.) of a speed change gear mechanism, which are selectively hydraulically actuated by line pressure to select a predetermined shift speed and change the actuating friction element. Shift to the gear position of.

For this reason, if the line pressure is too high, the transitional engagement capacity of the friction element becomes too large, causing a large shift shock, and if the line pressure is too low, the transitional engagement capacity of the friction element becomes too small and the friction element slips. As a result, the service life is shortened. Therefore, it is necessary to properly control the line pressure, and the applicant of the present invention previously mentioned in the patent application (3) filed on July 19, 1988, that
The gear ratio represented by the ratio between the input and output speeds of the speed change gear mechanism is detected and the inertia phase time, which is the time during which the gear ratio is changing, is measured. In this case, we proposed a line pressure control device that controls the increase / decrease of the appropriate amount by learning and corrects the line pressure with the correction amount so that the target value is determined for each type of gear change and engine throttle opening, which is the case time. ing.

On the other hand, an automatic transmission can normally select a manual shift by operating a select lever, and
In some cases, the shift pattern of automatic shifting can be changed from a normal economy pattern to a power pattern that shifts at a higher engine speed by operating the pattern selection switch. Since the vehicle speed at the time of shifting is different between the case of performing the manual shifting and the shifting of the power pattern and the shifting of the economy pattern, the vehicle speed at the time of shifting is different even with the same throttle opening, and therefore the target value is originally different.

For this reason, in the above conventional device, measurement is performed during a shift under a condition different from the precondition of the target value of the inertia phase time (for example, if the target value is compatible with the shift in the economy pattern, the condition is the shift in the economy pattern). It is assumed that the learning control of the correction amount is not performed during the inertia phase time, which prevents the line pressure from being corrected incorrectly due to erroneous learning.

(Problems to be Solved by the Invention) The inventors of the present application have found the following points to be improved while further studying the above-mentioned device.

That is, in the above line pressure control device, although erroneous learning can be prevented when shifting is performed under conditions different from the precondition of the target value, learning control is performed even during shifting under conditions different from the precondition. Since the correction of the line pressure is executed based on the correction amount adjusted by, the correction may cause the line pressure during shifting to become improper and cause a shift shock.

The present invention provides an apparatus that advantageously solves such problems.

(Means for Solving the Problems) As shown in FIG. 1, a line pressure control device for an automatic transmission according to the present invention selectively hydraulically operates various friction elements of a speed change gear mechanism by line pressure so that a predetermined speed is established. Of the input speed sensor and the output speed sensor of the speed change gear mechanism of the automatic transmission in which the speed change gear is changed to another speed stage by changing the friction element to be operated. Detecting each, based on the signals from those sensors, the inertia phase time measuring means measures the inertia phase time, which is the time during which the gear ratio represented by the ratio between the input and output speeds is changing, The pressure adjusting means performs learning control of the correction amount so that the inertia phase time becomes a target value according to the type of shift, and corrects the line pressure during the shift by the correction amount. In a line pressure control device for a dynamic transmission, different pattern shift signal output means for detecting and outputting a signal in the case of a shift in a shift pattern different from the shift pattern on which the target value is set, And a correction enable / disable determining means for restricting the learning control of the correction amount based on the inertia phase time and the correction of the line pressure during the shift of the line pressure adjusting means based on the signal from the different pattern shift signal output means. It is characterized by

(Operation) In such a device, the speed change gear mechanism selectively hydraulically operates various friction elements by the line pressure to select a predetermined shift speed, and the supply power is increased / decreased and output at this shift speed.
Then, the transmission gear mechanism is shifted to another gear by changing the friction element that is hydraulically operated.

During this shift, the input rotation sensor and the output rotation sensor respectively detect the input rotation speed and the output rotation speed of the transmission gear mechanism, and the inertia phase time measuring means
Based on the signals from both of these sensors, the inertia phase time, which is the time during which the gear ratio represented by the ratio between the input and output speeds of the transmission gear mechanism, is measured. Then, the line pressure adjusting means performs learning control of the correction amount such that the inertia phase time becomes a target value according to the type of shift, and corrects the line pressure during the shift by the correction amount.

On the other hand, the different pattern shift signal output means outputs a signal when the shift for measuring the inertia phase time is a shift pattern of a type different from the shift pattern premised on the setting of the target value (including the case of manual shift). Upon detecting it, a signal is output, and the correction possibility determining means, based on the signal from the different pattern shift signal output means, learning control of the correction amount based on the inertia phase time of the line pressure adjusting means and during the shift. Both line pressure corrections are regulated.

Therefore, according to this device, it is possible to perform line pressure control that takes into account individual differences and changes over time in the automatic transmission, and operating conditions of the automatic transmission of the transmission, and a large shift shock is generated due to excess or deficiency of the line pressure. It is possible to avoid shortening the life of friction elements and friction elements, and even if the automatic transmission has multiple types of shift patterns, the shift pattern that measures the inertia phase time is the shift pattern that is the prerequisite for setting the target value. Other than the case of gear shifting in the same type of shift pattern, that is, when the target value is set on the assumption that gear shifting is performed in economy pattern, for example, gear shifting in power pattern or manual When performing a shift, the learning control of the correction amount based on the inertia phase time measured during the shift and the correction amount Since the line pressure is not corrected during shifting, erroneous learning due to using the measured value of the inertia phase time during shifting in a shift pattern different from the shift pattern used to set the target value is prevented. It is possible to always control the line pressure during shifting with the above-mentioned type of shift pattern to be appropriate, and even when shifting with a shift pattern of a type different from the above-mentioned type of shift pattern, an incorrect line Since it is possible to prevent the pressure from being corrected, it is possible to sufficiently prevent the occurrence of a shift shock.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

FIG. 2 shows a power train control system of an automobile incorporating a device of an embodiment of a line pressure control device of the present invention, 1 is an electronically controlled fuel injection engine, 2 is an automatic transmission, 3 is a differential gear, and 4 is a drive. The wheels.

The engine 1 has an engine control computer 5,
This computer includes a signal from an engine rotation sensor 6 for detecting an engine speed N _E , a signal from a vehicle speed sensor 7 for detecting a vehicle speed V, a signal from a throttle sensor 8 for detecting an engine throttle opening TH, and an engine. A signal or the like from the intake air amount sensor 9 for detecting the intake air amount Q is input. The computer 5 determines the fuel injection pulse width T _P based on these input information, and commands this to the engine 1,
Further, the ignition timing of a spark plug (not shown) is determined and an ignition timing control signal T _I is supplied to the engine 1. The engine 1 is supplied with an amount of fuel corresponding to the fuel injection pulse width T _P, and is operated by burning this fuel by ignition of an ignition plug that is timed to the rotation of the engine.

Further, the automatic transmission 2 includes a torque converter 10 and a speed change gear mechanism 11 in tandem, and inputs engine power to the input shaft 12 via the torque converter 10. The input rotation of the transmission to the shaft 12 is accelerated and decelerated according to the selected speed of the transmission gear mechanism 11 to reach the output shaft 13, from which the drive gear 4 is passed through the differential gear 3 to drive the vehicle. it can.

Here, the speed change gear mechanism 11 incorporates various friction elements (not shown) such as clutches and brakes that determine the transmission path (gear stage) from the input shaft 12 to the output shaft 13, and these various friction elements are used for line pressure. It is assumed that the hydraulic pressure is selectively actuated by P _L to select a predetermined shift speed, and that the shift to another shift speed is performed by changing the friction element to be actuated.

For this shift control, a shift control computer 14 and a control valve 15 are provided here. The computer 14 selectively turns on the shift solenoids 15a and 15b for gear shift control in the control valve 15, and the lines are selectively connected to various friction elements so that the corresponding shift speed is selected by the combination of ON and OFF of these shift solenoids. Controls shift control by supplying pressure P _L. The shift control computer 14 also controls the line pressure control duty solenoid 16 in the control valve 15 by the drive duty D to control the line pressure P _L in the control valve 15 (the line pressure increases as the duty D increases). It shall be controlled as intended by the invention. For the shift control and the line pressure control, a signal from the vehicle speed sensor 7 and a signal from the throttle sensor 8 are input to the computer 14, and the rotation speed N _{T of the} shaft 12 is also input.
A signal from an input rotation sensor 17 for detecting the rotation speed and a signal from an output rotation sensor 18 for detecting the rotation speed N _O of the shaft 13 are input.

The vehicle here also comprises a cooling device 19, which has a compressor 20 for compressing the refrigerant.
Is drivingly connected to the output shaft of the engine 1 via a pulley 21 and a belt 22 with a built-in clutch.
Is activated by the ON operation of the cooling device operation switch 23, the clutch is appropriately engaged, and the compressor 20 is operated by the driving force of the engine 1.

Here, the signal A _C from the cooling device operating switch 23 is also input to the shift control computer 14 in order to detect when the cooling device 19 is operating.

The automobile here further includes a power steering device 24 that applies a steering assist force to a steering device that steers steering wheels (not shown) by steering a steering wheel (not shown). An oil pump that is a hydraulic source of the power steering device 24 is provided. 25 is drivingly coupled to the output shaft of the engine 1 via a pulley and the belt 22. The power steering device 24 is a hydraulic oil discharged by the oil pump 25 while the steering reaction force against the steering of the steering wheel is small. By draining the oil pump 25, the driving force of the oil pump 25 is reduced, and when the steering angle of the steering wheel is increased and the steering reaction force is increased, operating pressure is generated by the oil pump 25 by switching the valve (not shown) The steering assist force is brought from hydraulic pressure.

Here, when the power steering device 24 is in operation, that is, when the operating oil pressure is generated by the oil pump 25, a steering angle for detecting the steering angle S _A of the steering wheel is also detected in order to detect the operating oil pressure. The signal from the sensor 26 is also input to the computer 14.

In addition, here, in order to detect a decrease in engine output due to an excessive decrease in atmospheric pressure, the shift control computer 14
In addition, a signal from the atmospheric pressure sensor 27 that detects the atmospheric pressure A _P is also input.

Further, here, in order to perform engine output control for reducing shift shock, the engine control computer 5
To, thereby enabling input and a retard instruction signal R the inertia phase signal I _F from the shift control computer 14 receives a signal from the coolant temperature sensor 28 for detecting the water temperature T _W of the cooling water of the engine 1 Also, the retard execution signal R _A from the engine control computer 5 can be input to the shift control computer 14.

In addition, the automatic transmission 2 in this case has an economy pattern that shifts at a relatively low vehicle speed at each throttle opening TH to keep the engine speed low and to improve fuel economy, and at each throttle opening TH. , Two types of shift patterns are selectively used: a power pattern that shifts at a relatively high vehicle speed to keep the engine speed at a high level, and that makes the vehicle responsive to a throttle pedal operation good, and Therefore, here, the signal S _P from the shift pattern selection switch 29 is also input to the computer 14.

Further, the computer 14 indicates that the driver has the automatic transmission 2
A signal M _S from the inhibitor switch 30 indicating that manual shift is performed by operating a select lever (not shown)
Also enter.

Further, here, in order to detect a case where the engine state during shifting includes a power-off state in which the required amount of the transitional engagement capacity of the friction element of the transmission gear mechanism 11 is different from the power-on state, the throttle valve is detected. The signal I _S from the idle switch 31 that turns ON when the engine throttle opening TH is close to fully closed is also input to the computer 14, and in addition,
A signal from the hydraulic oil temperature sensor 32 is also input to the computer 14 in order to detect the case where the inertia phase time is longer than usual because the hydraulic oil temperature T _O of the automatic transmission 2 is too low.

Then, the computer 14 executes the control programs shown in FIGS. 3 to 6 to perform the line pressure control and the shift control.

First, the line pressure control program of FIG. 3 which is repeatedly executed by the timed interrupt will be described. In step 40, it is checked whether or not a gear change is in progress depending on whether a flag FLAG1 described later is 1 or not. As a result, if non-shifting is in progress (FLAG1 = 0), in step 41, the line corresponding to the throttle opening TH from the non-shifting duty table 1 written in the RAM, for example, as shown by the solid line A in FIG. The pressure control solenoid drive duty D is looked up in a table, and then in step 42 this drive duty D is output to the solenoid 16 to control the line pressure P _L to a normal value for non-shifting.

On the other hand, if the result of the above check is that the gear is in the middle of shifting (FLAG1 = 1), then in step 43, it differs depending on the type of gear shifting such as gear stage, upshift / downshift, etc. This is also as shown by the dotted line B in FIG. The line pressure control solenoid drive duty D corresponding to the throttle opening TH is looked up from the characteristic duty table 2 for shifting, and then at step 44, the shifting is particularly likely to cause a shift shock due to excessive line pressure. It is checked whether or not it is a shift gear shift, and if it is not an up shift gear shift as a result, in the device of this example, the drive duty D is output to the solenoid 16 as it is in step 42. On the other hand, in the case of the up-shift gear shift, in step 45, the flag FLAG3 indicating whether learning control is possible is checked, and the FLA indicating learning is possible.
When G3 = 0, in the next step 46, the line pressure control corresponding to the throttle opening TH is made from the correction amount table as shown in FIG. Solenoid drive duty correction amount ΔD
Then, in step 47, D + ΔD is output to the solenoid 16 to control the line pressure P _L to a value for shifting, and if FLAG3 = 1 indicating non-learning, the process proceeds to step 42 and the drive duty D is left unchanged. Output to solenoid 16.

Next, the shift control and line pressure control solenoid drive duty correction amount control of FIG. 4, which is also repeatedly executed by a timed interrupt, will be described.
Whether FLAG1 is 1 or not, that is, whether or not gear shifting is in progress, and if non-gear shifting (FLAG1 = 0), in step 51, it is checked whether delay skip flag FLAG4, which will be described later, is 1 or not, and FLAG4 = 1 Otherwise, determines the required gear speed that corresponds to the combination of the vehicle speed V and the throttle opening TH based on the shift pattern selected on the basis of the signal S _P output from the shift pattern selection switch 29 at the subsequent step 52.

Here, the shift pattern selection switch 29 can be selectively operated to "auto" or "power", and the shift control computer 14 _confirms that the signal SP from the switch 29 has been operated to "auto". In the case shown, the economy pattern is normally used, and when the stepping speed of the throttle pedal is equal to or higher than the set value determined according to the throttle opening TH and the vehicle speed V, the power pattern is changed and the throttle opening TH is changed. While returning to below a certain level and returning to the economy pattern after a certain period of time, only the power pattern is used when the signal S _P indicates that the signal is operated to “power”.

In step 52, the inhibitor switch 30
It is also checked whether or not the manual shift is performed on the basis of the signal M _S from, and in the case of the manual shift, the required shift speed is limited to the low shift speed (for example, the first speed or the second speed).

In the next step 53, it is checked whether or not the gear shift should be performed depending on whether or not the requested gear is different from the currently selected gear, and if the gear shift should be made as a result, the flag FLAG4 is set to 1 in step 54. And the timer T ₁ for measuring the delay time is reset to 0, and the flag FLAG
Reset 3 to 0. By executing this step 54,
When step 51 is executed next time, steps 52 to 56 are skipped and the process proceeds to step 57, and the delay time can be measured.

In step 55, it is determined whether or not engine output control is necessary based on the type of shift from the current shift stage to the required shift stage determined in step 52. That is, in this embodiment, the type of shift is a constant throttle opening TH
In the case of a power-on upshift gear shift operation performed in response to an increase in the vehicle speed V below, the engine output torque is slightly reduced in order to reduce the gear shift shock caused by the inertia torque of the speed change gear mechanism 11. If the type of shift is the power-on upshift shift in step 55, the routine proceeds to step 56, where the retard instruction signal R for reducing the engine output torque is output, while in the case of other shifts, steps 56 and 57 are executed. Skip and do not perform engine output control. Whether or not the shift is in the power-on state is determined by the signal I _S from the idle switch 31,
If the idle switch 31 is not in the ON state, the throttle opening TH is not in the fully closed state, so it is determined that the shift is in the power-on state.

Then, the engine control computer 5, which receives the retard instruction signal R, checks the cooling water temperature T _W and the power supply voltage (battery voltage), and the cooling water temperature T _W is less than a predetermined temperature or the power supply voltage is less than a predetermined value. In this case, if the ignition timing is delayed, the output torque of the engine 1 may be excessively reduced or the engine 1 may be stopped. Therefore, the retard execution signal R _A is not output, and the ignition timing is advanced normally. However, if the cooling water temperature T _W is equal to or higher than the predetermined temperature and the power supply voltage is equal to or higher than the predetermined value, the retard execution signal R _A is output because there is no fear of the above.

In step 57, it is judged whether or not the retard execution signal R _A is input. If it is input, the process proceeds to step 58, in which the flag FLAG1 is set to 1 so as to indicate that the shift is in progress, and the solenoid 15a, 15b is switched between ON and OFF to execute the shift to the required shift stage, and further, the current value S _A of the steering angle is set to the maximum steering angle value S _Amax . On the other hand, if the retard execution signal R _A is not input in step 57, step
Timer T up to predetermined delay time T _1S by 59 and step 60
₁ is incremented (stepped), and it is determined by the arithmetic processing of the engine control computer 5 whether or not the retard angle is executed. Then, if the retard execution signal R _A is not input even if the timer T ₁ is equal to or more than T _1S , it is determined that the retard is not executed, that is, the engine output control is not performed, and the flag FLAG3 is set in step 61. After setting to 1, step 58
Proceed to. As a result, the flag FLAG3 is FLAG3 = 1 when the shift is of a type in which engine output control is performed and that shift control is not performed.

When the gear shift is in progress (FLAG1 = 1) in step 58 above, in the next control, the routine proceeds from step 50 to step 62, and it is determined whether S _Amax . ≧ S _A, that is, the current value of the steering angle.
It is checked whether S _A has increased from the maximum steering angle value S _Amax ., And if it has not increased as a result (S _Amax . ≧ S _A ), it remains the same, or if it has increased (S _Amax . < S _A ), step
At 63, S _Amax . _{Is set} to the increased current value S _A, and then the process proceeds to the next step 46. As a result, the maximum turning angle during the gear shift is peak-held at the maximum turning angle S _Amax .

In step 64, the learning availability determination subprogram shown in FIG. 5 is executed to compare the conditions of the current shift with the predetermined conditions of the target value T _2S of the inertia phase time described later, and if the conditions are different, , A flag FLAG3 indicating whether learning control is possible is set to 1 to indicate non-learning (FLAG3 = 1).

In this subprogram, first, at step 80, the maximum turning angle value S _Amax . During the current shift is equal to or greater than a predetermined value S _AS (S _{Amax at} which a large force is required to drive the oil pump 25 of the power steering device 24). ..Gtoreq.S _AS ), and as a result, if it is not S _AS or more, the flag FLAG3 indicating learning availability is maintained at 0 to perform learning control, and while proceeding to step 81, S If it is _AS or more, the flag FLAG3 is set to 1 in step 87 so that learning control is not performed.

In step 81, it is checked whether or not the state of the cooling device operating switch 23 is in the ON state by the signal A _C , and if it is not in the ON state as a result, the flag FLAG3 is maintained at 0, and the process proceeds to step 82 while it is in the ON state. For example, the compressor of the air conditioner 19
Since there is a possibility that 20 is being driven, the flag FLAG3 is set to 1 in step 87.

Then, in step 82, it is checked whether the atmospheric pressure A _P is a predetermined value A _PS or less (A _P ≤A _PS ) at which the output of the engine 1 starts to significantly decrease, and as a result, it must be A _PS or less. For example, keep flag FLAG3 at 0 and proceed to step 83 while A
If it is equal to or lower than _PS , the flag FLAG3 is set to 1 in step 87.

In the subsequent step 83, it is checked whether or not the idle switch 31 is ON by the signal I _S , and the idle switch 31 is turned on.
If it is ON, FLAG3 = 1 is set in step 87 to indicate that the engine state during shifting includes the power-off state, and if the idle switch is not ON in step 83, FLAG3 is set.
With = 0, the process proceeds to step 84.

At step 84, the operating oil temperature T _O of the automatic transmission 2 is a predetermined temperature at which the inertia phase time becomes longer than usual due to an operation delay in the hydraulic circuit due to the oil temperature being too low.
It is checked whether T _OS or less (T _O ≦ T _OS ), and if it is not T _OS or less as a result, the process proceeds to step 85 while FLAG3 = 0, while if T _OS or less, FLAG3 = at step 87. Set to 1.

In the following step 85, it is checked whether or not the manual shift is in progress. If the manual shift is in progress, in step 87 FLAG3
On the other hand, if the manual shift is not being performed, that is, if the automatic shift in the economy pattern or the power pattern is being performed, the process proceeds to the next step 86. Then, in step 86, it is checked whether or not the power pattern is in use. If the power pattern is in use, in step 87 FLAG
While this subprogram is ended with 3 = 1, while the economy pattern is being used, this subprogram is ended with FLAG3 = 0 and the process returns to the previous step 64.

Due to the execution of such a subprogram, the output torque of the engine 1 is consumed to drive the oil pump 25 and the compressor 20, or the atmospheric pressure A _P is too low while traveling in a highland, and the engine output state is the normal condition. The required state of the transitional engagement capacity of the friction element is different from that of the automatic transmission in the normal condition, which may cause the target value of the inertia phase time to be different from that in the normal condition, or the gear change to power off. If the target value of the inertia phase time is different from that in the power-on state, or if the gear shift is performed in a mode other than the economy pattern and the vehicle speed during the shift is different, the target value of the inertia phase time is the economy pattern. If it is different from that in the gear shift in the above, and the operating oil temperature T _O of the automatic transmission 2 is too low, the inertia If the time is longer than usual, FLAG3 = 1.

On the other hand, here, the target value T _2S of the inertia phase time used for learning control of the correction amount ΔD, which will be described later, is a gear shift in the power-on state, and the computer 14 requests the engine output control from the computer 5 and the computer 5 Doing that, and the engine output torque is the oil pump
25 or the compressor 20 is being driven or the atmospheric pressure A _P is too low, so the pressure does not drop too low, and the gear shifting is performed in the economy pattern, and the hydraulic oil temperature T _O is low. Under the precondition that the line pressure is not too high, the line pressure is set to a value at which the line pressure during shifting is most appropriate in terms of preventing shift shock and shortening the life of the friction element.

Therefore, in this embodiment, if gear shifting is performed under a condition different from the precondition of the target value T _2S , FLAG3 = 1 as non-learning is shown by the judgment immediately after the gear shifting command,
Steps in the line pressure control program of FIG. 3 described above
At 45, correction of the line pressure control solenoid drive duty D by the correction amount ΔD is prohibited.

It should be noted that step 64 in FIG. 4, that is, the learning feasibility determination subprogram is repeatedly executed not only immediately after the gear shift command but also during the gear shift. Therefore, even when the determination results of the above steps 80 to 86 change during the gear shift. Since FLAG3 = 1, correction of the drive duty D by the correction amount ΔD is prohibited thereafter.

In step 65 subsequent to step 64, it is checked whether or not the inertia phase is in progress, and in this check, the gear ratio represented by the input / output speed ratio N _T / N _O of the speed change gear mechanism 11 is changed before the speed change. It is determined that the inertia phase is in progress while the gear ratio corresponding to the gear is changing toward the gear ratio corresponding to the gear after the gear shift. Then, here, the timer T ₂ is incremented in step 66 during the inertia phase, and steps 66 and 67 after the inertia phase are skipped to measure the inertia phase time in the timer T ₂ .

In step 67 outputs the inertia phase signal I _F,
Thus during the inertia phase signal I _F is the inertia phase, that is, be between the output gear ratio is actually changed. Then, when the retard control execution signal R _A is output first, the engine control computer 5 appropriately delays the ignition timing only while the inertia phase signal I _F is being input to slightly increase the output torque of the engine 1. This reduces the shift shock effectively at the proper time.

In the next step 68, it is checked whether or not the inertia phase has ended (end of gear shifting). If not completed, the program ends as it is, and if completed, step
At 69, the flag FLAG1 is reset to 0 in response to the end of the shift, the flag FLAG4 is reset to 0, and the learning control for correcting the data in the correction amount table in the RAM shown in FIG. 7 is executed. FLAG2 is 1
Set to.

In this way, while the gear shifting is completed and the gear shifting is not performed thereafter, the control proceeds to step 70 through steps 50 to 53,
Since FLAG2 is set to 1 as described above, step 71 is selected and the previous data of the line pressure control solenoid drive duty correction amount ΔD shown in FIG. 8 is corrected and updated by the following learning control.

In step 71, the learning control subprogram shown in FIG. 6 is executed. First, in step 90, FLAG3 = 1
If it is not FLAG3 = 1, the previous shift was a shift under the conditions that match the preconditions of the target value T _2S of the inertia phase time.
Proceed to 91 to check if the last shift was an upshift. If the shift is not the upshift, the learning control is not performed as described above, and the process ends. On the other hand, in the case of the upshift, the target value of the inertia phase time (shift type and throttle Look up T _{2 S} from the inertia phase time target value table in RAM, and
In step 93, the line pressure control solenoid drive duty correction amount ΔD corresponding to the throttle opening TH is looked up from the above-mentioned correction amount table corresponding to the type of shift, and in step 94, the timer which is the inertia phase time. The measurement time T ₂ is compared with the above target value T _2S .

This, for example, as shown in FIG. 10, up the automatic transmission 2 by the vehicle speed increases the engine throttle opening degree constant from the first speed to the second speed and OFF one of the shift solenoids 15a from ON instantaneously t ₁ Looking at the case of shifting gears, when the line pressure is appropriate, the second speed selection pressure with this as the original pressure rises as shown by the solid line and the corresponding friction element is engaged and advanced.
The gear ratio of the speed change gear mechanism 11 changes from the value corresponding to the first speed to the value corresponding to the second speed as shown by the solid line, and the transmission output torque changes as shown by the solid line, but if the line pressure is too low, there is one point. The operation waveform becomes as shown by the chain line, and the inertia phase time T ₂ is shortened in accordance with the increase of the line pressure control solenoid drive duty D + ΔD, and accordingly the increase of the line pressure, as shown in FIG. This is because it is possible to determine whether or not the line pressure is appropriate by comparing the target value T _2S, which is the inertia phase in this case, with the measured inertia phase time T ₂ .

As a result of the comparison in step 94, when T ₂ coincides with T _2S , the table data in the RAM of the correction amount ΔD is not changed and used as it is for the line pressure control during the next shift.
However, when T ₂ > T _2S, the line pressure is too low, as shown by the alternate long and short dash line in Fig. 10, and the life is shortened due to the sliding of the friction elements. The table data in the RAM of the corresponding correction amount ΔD is increased by 0.2% and used for line pressure control during the next shift. Therefore, at the time of the next line pressure control, the line pressure control solenoid drive duty D + ΔD is increased by 0.2% from the previous time, and the line pressure can be increased by that amount, and the line pressure can be brought close to an appropriate value as shown by the solid line in FIG. It is possible to avoid shortening the life of the friction element. On the other hand, when T ₂ <T _2S , the line pressure is too high and a large shift shock is generated due to the excessive engagement capacity of the friction element.
By executing 96, the correction amount ΔD corresponding to the type of shift
The table data in the RAM of is reduced by 0.2% and used for line pressure control during the next shift. Therefore, the line pressure control solenoid drive duty D + ΔD at the time of the next line pressure control is reduced by 0.2% from the previous time, and the line pressure can be reduced by that amount, and the line pressure can be brought close to an appropriate value to prevent a large shift shock. You can

The other hand, in the case of step 90 in FLAG3 = 1, the value of T ₂ measured is because it is intended during shifting under conditions different from the assumptions of the target value T _2S, when it executes the learning control, Even if the line pressure is originally proper, the measured value T ₂ of the inertia phase time differs from the target value T _2S , so the correction amount Δ
Since D will be increased or decreased unnecessarily, and the line pressure during shifting will be improper, which will cause a shift shock. Therefore, in order to prevent such erroneous learning, the table data of the correction amount ΔD is not corrected, The sub program is finished as it is, and the process returns to step 71.

Then, thereafter, in step 72, the flag FLAG2 is reset to 0, the value of the timer T ₂ is reset to 0, and the next measurement is awaited.

By repeating the above-described operation (learning control), the line pressure solenoid drive duty correction amount ΔD is the line pressure control solenoid drive duty D + ΔD during gear shifting, and the line pressure is an appropriate value (regardless of individual differences of the automatic transmission or change over time). Continue to correct the inertia phase time T ₂ to a value that makes it the target value T _2S ), and control the line pressure during shifting to an appropriate value that will not cause a reduction in the life of friction elements or a large shift shock under any circumstances. can do.

Moreover, according to the device of this example, only when the shift for measuring the inertia phase time T ₂ is a shift under the condition that meets the precondition of the target value T _2S , the line being changed is used by using the correction amount ΔD. Since the pressure is corrected and learning control of the correction amount ΔD based on the measurement time T ₂ is performed after the shift is completed, the inertia phase time T ₂ measured under a condition different from the precondition of the target value T _2S is used. Of course, learning can be prevented, and during shifting under conditions different from the above prerequisites, for example, a condition in which the output torque of the engine 1 is consumed to drive the oil pump 25 and the compressor 20 and falls below the normal state. Even when the gear is changed down, if the correction value ΔD is corrected as it is, the line pressure is increased as shown by the broken line in FIG. 10 to cause a gear shift shock. As shown by the chain double-dashed line in the figure, the occurrence of shift shock can be sufficiently prevented.

Although the present invention has been described above based on the illustrated example, the present invention is not limited to the above example. For example, learning control is performed not only in upshifting but also in downshifting, and the learning control and line pressure are performed. It may be possible to determine whether or not to correct the above.

Further, as a material for determining whether or not the shift in which the inertia phase time is measured is different from the precondition of the target value, the shift control computer 14 itself may be used by the engine 1 as well as the above-described embodiment. Output control of the engine 1, whether the ignition timing retard amount for output control of the engine 1 is a predetermined amount, or whether the engine control computer 5 outputs a signal indicating a malfunction of the engine 1. It is also possible to use data such as whether or not.

(Effect of the invention) Thus, according to the line pressure control device of the present invention, even when the automatic transmission has a plurality of types of shift patterns, the shift for measuring the inertia phase time is a shift that is a premise for setting the target value. Except in the case of shifting with the same type of shift pattern as the pattern, learning control of the correction amount based on the inertia phase time measured during the shift and correction of the line pressure during the shifting with the correction amount are not performed. During the shift in the shift pattern of the above-described type by preventing erroneous learning due to the use of the measured value of the inertia phase time during the shift in the shift pattern of the type different from the shift pattern of the set target value The line pressure can be controlled properly at all times, and moreover,
Even during a shift with a shift pattern of a type different from the above-described shift pattern, it is possible to prevent the improper correction of the line pressure, so that the shift shock can be sufficiently prevented.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a line pressure control device of the present invention, FIG. 2 is a control system diagram of an automobile power train showing an embodiment of the present invention device, and FIGS. 3 to 6 are shift control computers in the same example. 7 is a flow chart showing a line pressure control and shift control program of FIG. 7, FIG. 7 is a characteristic diagram of a line pressure control solenoid drive duty, and FIG. 8 is a momentary RAM regarding a correction amount of the duty.
Fig. 9 is a diagram illustrating the data in Fig. 9, Fig. 9 is a relational diagram of the timer measurement time with respect to the line pressure control solenoid drive duty during shifting, and Fig. 10 is a shifting operation time chart showing the occurrence status of inertia phase during shifting. is there. 1 ... Electronically controlled fuel injection engine 2 ... Automatic transmission 3 ... Differential gear 4 ... Drive wheel 5 ... Engine control computer 6 ... Engine speed sensor 7 ... Vehicle speed sensor 8 ... Throttle sensor 9 ... Intake air amount sensor 10 …… Torque converter 11 …… Shift gear mechanism 14 …… Shift control computer 15 …… Control valves 15a, 15b …… Shift control shift solenoid 16 …… Line pressure control duty solenoid 17 …… Input Rotation sensor 18 …… Output rotation sensor 19 …… Cooling device 20 …… Compressor 23 …… Cooling device operating switch 24 …… Power steering device 25 …… Oil pump 26 …… Steering angle sensor 27 …… Atmospheric pressure sensor 28… Cooling water temperature sensor 29 Shift pattern selection switch 30 Inhibitor switch 31 Idle switch 32 Hydraulic oil Temperature switch

Claims (1)

(57) [Claims] 1. An automatic control system in which various friction elements of a speed change gear mechanism are selectively hydraulically actuated by line pressure to select a predetermined speed step, and a gear to be operated is changed to another speed step by changing the operating friction element. The input rotation sensor and the output rotation sensor detect the input rotation speed and the output rotation speed of the transmission gear mechanism of the transmission, respectively, and based on the signals from these sensors, the inertia phase time measuring means determines the input / output rotation speed. The inertia phase time, which is the time during which the gear ratio represented by the ratio between the numbers is changing, is measured, and the line pressure adjusting means adjusts the correction amount so that the inertia phase time becomes a target value according to the type of shift. In a line pressure control device for an automatic transmission, which performs learning control and corrects the line pressure during the shift with the correction amount, a shift pattern based on the premise of setting the target value. Different pattern shift signal output means for detecting and outputting a signal in the case of a shift in a different type of shift pattern, based on the signal from the different pattern shift signal output means,
A line for an automatic transmission, characterized in that: the line pressure adjusting unit includes a learning control of a correction amount based on the inertia phase time and a correction feasibility determining unit that regulates correction of the line pressure during gear shifting. Pressure control device.