JPH0781630B2 - 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 excessive and a large shift shock occurs, 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. For example, in the past, "Automatic Transmission RE4RO1A Type Maintenance Manual" (A261CO7) issued by Nissan Motor Co., Ltd. in March 1987 was used.
As described in (1), the line duty is controlled by determining the drive duty of the line pressure control solenoid based on the engine throttle opening based on different table data during shifting and non-shifting.

However, in such a conventional line pressure control device, when the line pressure control solenoid has variations in the product, when the characteristics change over time, or when the friction element has variations in the product, the friction material ages. When there are changes, it is not possible to cope with them sufficiently.In the former case, the line pressure deviates from the proper value even with the same solenoid drive duty, and in the latter case, even if the line pressure is controlled as intended, it will be an appropriate value for the friction element. In either case, there is a possibility that a large shift shock or a shortened life of the friction element may occur due to excess or deficiency of the line pressure.

By the way, for example, as shown in FIG. 9, in the case where the automatic transmission of the above document shifts the shift solenoid from ON to OFF at the instant t ₁ due to the decrease of the engine throttle opening degree to shift up from the first speed to the second speed, As can be seen, when the line pressure is low, the second speed selective pressure, which is based on this line pressure, rises as shown by the solid line and the corresponding friction element is engaged and advanced, and the input / output speed ratio N _T / of the transmission gear mechanism is increased. The gear ratio represented by N _O N _T : input speed, N _O : output speed changes from the 1st speed equivalent value to the 2nd speed equivalent value as shown by the solid line, and the transmission output torque becomes as shown by the solid line. In contrast to this, when the line pressure is high, the operation waveform is as shown by the dotted line. Therefore, it is possible to determine from the time during which the gear ratio N _T / N _O is changing, that is, the inertia phase time T, whether the line pressure is an appropriate value in consideration of the above-mentioned variations and changes over time. From this point of view, the present applicant has previously described in Japanese Patent Application No. 62-327452 the input rotation speed and the output rotation speed of the transmission gear mechanism of the automatic transmission described above by the input rotation sensor and the output rotation sensor, respectively. Detecting, based on the signals from these sensors, the inertia phase time measuring means measures the time during which the gear ratio represented by the comparison between the input and output rotational speeds is changing, and the lie pressure adjusting means, We have proposed a line pressure control device that controls the learning of the line pressure during the shift so that the inertia phase time becomes a target value according to the type of shift. The learning control of the line pressure can be performed, and it is possible to avoid the occurrence of a large shift shock and the reduction of the life of the friction element due to the excess or deficiency of the line pressure.

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

That is, among the automatic transmissions installed in the vehicle,
When the power-on upshift is performed, the ignition timing is delayed by the computer for controlling the engine that drives the automatic transmission, as disclosed in Japanese Patent Laid-Open No. 60-260749 by the present applicant. There is a device that reduces the shock of gear shift by controlling the engine output so that the engine output is slightly reduced only during the gear shift. If the water temperature is too low or the power supply voltage is too low, the engine output may decrease excessively, so the engine control computer does not retard the ignition timing. Does not happen.

However, when the conventional line pressure control device is applied to an automatic transmission including the above-described gear shift shock reducing device, when the engine output control is always performed when a gear shift of a type for performing engine output control is performed. The target value of the inertia phase time of was compared with the measured inertia phase time, and the line pressure was learned and controlled. Therefore, the engine control computer measured when the ignition timing was not retarded. There was a risk that it would not be possible to sufficiently prevent the occurrence of a gear shift shock, because it was determined that the inertia phase time was too long and erroneous learning was performed to raise the line pressure excessively.

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. Is selected to change the friction element to be operated to shift to another shift speed, and the output of the drive source for driving the shift gear mechanism is made different during shifting and non-shifting, depending on the type of shifting. An input rotation sensor and an output rotation sensor respectively detect the input rotation and the output rotation speed of the transmission gear mechanism of the automatic transmission configured to perform drive source output control, and based on the signals from these sensors, the inertia phase The time measuring means measures an inertia phase time, which is a time during which the gear ratio represented by the ratio between the input and output speeds is changing, and the line pressure adjusting means measures the inertia phase time. In a line pressure control device that controls a line pressure during a shift so that a time becomes a target value according to the type of shift, the shift in which the inertia phase time is measured is of a type that performs the drive source output control. A drive source output non-control signal output means for outputting a signal indicating that the shift is not performed by the drive source output control, and the line pressure adjusting means based on the signal from the drive source output non-control signal output means. And a control restricting means for restricting control of the line pressure during shifting based on the inertia phase time.

(Operation) In such a device, the transmission 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, if the type of shift is predetermined,
The automatic transmission performs drive source output control that makes the output of the drive source different from that during non-shifting. 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. 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 rotational speeds of the transmission gear mechanism is changing based on the signals from these sensors. Then, the line pressure adjusting means controls the line pressure during the shift so that the inertia phase time becomes a target value according to the type of shift.

On the other hand, the drive source output non-control signal output means is such that the shift in which the inertia phase time is measured is of a type in which the drive source output control is performed and the drive source output control is not performed. The control regulation means regulates the learning control of the line pressure during the shift of the line pressure adjustment means based on the inertia phase time, based on the signal from the drive source output non-control signal output means. To do.

Therefore, according to this device, even if there is product variation in the line pressure control element or characteristics change over time, or if there is product variation in the friction element or friction material change over time, these It is possible to perform line pressure control that takes into account individual differences and changes over time in automatic transmissions, and it is possible to avoid the occurrence of large gear shift shocks and shortened friction element life due to excess or deficiency of line pressure, as well as the inertia phase. If the type of shift for which the time has been measured is of the type that performs drive source output control, only when the condition for setting the target value of the inertia phase time corresponding to that type of shift is met, that is, for example, for the drive source When the target value is set under the conditions for output control, learning control based on the measured inertia phase time is performed only when drive source output control is actually performed. Is performed, to prevent erroneous learning by using the measured values of the inertia phase time in the conditions different from the setting conditions of the target value, it is possible to makes it always proper to control the line pressure during shifting.

(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 includes an engine control computer 5, which 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, and an engine throttle opening TH. The signal from the throttle sensor 8 for detecting, the signal from the intake air amount sensor 9 for detecting the engine intake air amount Q, etc. are input. The computer 5 determines the fuel injection pulse width T _P based on these input information, commands this to the engine 1, further determines the ignition timing of the spark plug (not shown), and supplies the ignition timing control signal T _I to the engine 1. To do. The engine 1 is supplied with an amount of fuel according to the combustion 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, here is a computer for shift control.
14 and control valve 15 are provided. Computer
14 selectively turns on shift control shift solenoids 15a and 15b in the control valve 15 and selectively selects line pressure to various friction elements so that a corresponding shift stage is selected by a combination of ON and OFF of these shift solenoids. Supply P _L to control shift control. 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. A signal from the vehicle speed sensor 7 and a signal from the throttle sensor 8 are input to the computer 14 for the shift control and the line pressure control, respectively, and a signal from an input rotation sensor 17 for detecting the rotation speed _NT of the shaft 12 and Number of rotations of shaft 13
The signal from the output rotation sensor 18 for detecting N _O is input.

Further, here, in order to perform engine output control for reducing shift shock, the engine control computer 5
Thereby enabling input and the retard instruction signal R from the transmission control computer 14 and the inertia phase signal I _F, coolant temperature sensor 19 for detecting the water temperature T _W of the cooling water of the engine 1
Input the signal from the
To the retard execution signal from the engine control computer 5
R _A can be input.

Then, the computer 14 executes the control programs shown in FIGS. 3 to 5 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 30, 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 (FLAG1 = 0), step 3
In step 1, the line pressure control solenoid drive duty D corresponding to the throttle opening TH is tabled up from the non-shifting duty table 1 having the characteristics shown by the solid line A in FIG. Then, in step 32, the drive duty D is output to the solenoid 16 to control the line pressure P _L to the normal value for non-shifting.

On the other hand, if the result of the above check indicates that the gear is in the middle of shifting (FLAG = 1), then in step 33, it differs depending on the type of gear shifting such as gear stage, upshift / downshift, etc. This is also indicated by dotted line B in FIG. 6 in RAM.
The line pressure control solenoid drive duty D corresponding to the throttle opening TH is looked up from the shift duty table 2 having the characteristic as shown in FIG. It is checked whether or not the upshift gear shift is likely to occur, and if it is not the upshift gear shift as a result, in the device of this example, the drive duty D is determined in step 32.
Is output to the solenoid 16 as it is. On the other hand, in the case of the upshift gear shift, in step 35, the line pressure corresponding to the throttle opening TH is calculated from the correction amount table shown in FIG. The control solenoid drive duty correction amount ΔD is looked up, and then, in step 36, D + ΔD is output to the solenoid 16 to control the line pressure P _L to a value for shifting.

Next, the shift control and line pressure control solenoid drive duty correction amount control of FIG. 4 which is also repeatedly executed by the timed interrupt will be described. First, at step 40, the flag FL
Check whether AG1 is 1, that is, whether gear shifting is in progress,
If the gear is not being shifted (FLAG1 = 0), in step 41, it is checked whether or not a delay skip flag FLAG4, which will be described later, is 1, and if FLAG4 = 1 is not established, then in step 42, a predetermined normal shift pattern is set. Based on, the required shift speed corresponding to the combination of the vehicle speed V and the throttle opening TH is determined.

In the next step 43, it is checked whether or not a shift should be made depending on whether or not the required shift stage is different from the currently selected shift stage,
If the result is a gear change, step 44
FLAG4 is set to 1, the timer T ₁ for measuring the delay time is reset to 0, and further, the flag FLAG3 indicating whether or not the engine output control is executed is reset to 0. By executing this step 44, the next step 41
When executing, skip steps 42 to 46 and skip to step 47.
Then, the delay time can be measured.

In step 45, 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 42. That is, in this embodiment, the type of shift is caused by the inertia torque of the shift gear mechanism 11 in the case of power-on upshift shift which is performed in response to an increase in the vehicle speed V under a certain throttle opening TH of a certain size. The engine output torque shall be slightly reduced in order to reduce the shift shock caused by this.Therefore, if the type of shift is the power-on upshift shift in step 45 above, the process proceeds to step 46 and the delay for reducing the engine output torque is performed. While the angle instruction signal R is output, steps 46 and 47 are skipped and engine output control is not performed in the case of other gear shifts.

The engine control computer 5 that has input the retard instruction signal R checks the cooling water temperature T _W and the power supply voltage (battery voltage), and if the cooling water temperature T _W is less than a predetermined temperature or the power supply voltage is less than a predetermined value. Delays the ignition timing, the output torque of the engine 1 may excessively decrease or the engine 1 may stop. Therefore, the retard execution signal _RA is not output, and the ignition timing is in the normal advance state. 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 47, it is judged whether or not the retard execution signal R _A is input. If it is input, the process proceeds to step 48, 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 turned ON / OFF to execute the shift to the required shift stage, while if the retard execution signal P _A is not input in step 47, the timer T is set to the predetermined delay time T _{1S in} steps 49 and 50. Increment ₁
However, by the arithmetic processing of the engine control computer 5,
It has a judgment as to whether or not to execute retard. And timer T ₁
If the retard angle execution signal R _A is not input even if is equal to or greater than T _1S , it is determined that the retard angle is not executed, that is, the engine output control is not performed, and the flag FLAG3 is set to 1 in step 51. , Go to step 48. 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.

Since FLAG = 1 was set in step 48, the next step
When executing 40, skip steps 41-51 and step
Continue to 52.

In Steps 52, 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 corresponds to the gear stage before the speed change. It is determined that the inertia phase is in progress while the gear ratio is changing from the ratio toward the gear ratio corresponding to the gear after the gear shift. And here, step 53 during the inertia phase
The timer T ₂ is incremented by and the steps 53 and 54 are skipped after the inertia phase, whereby the timer T ₂ measures the inertia phase time.

In step 54, the inertia phase signal I _F is output, so that the inertia phase signal I _F is output during the inertia phase, that is, while the gear ratio is actually changing. 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. Then, as shown by the chain line in FIG. 9, the shift shock is effectively reduced at an appropriate time.

In the next step 55, it is checked whether or not the inertia phase is completed (shift is completed), and if not completed, the program is terminated as it is, and if completed, the step is completed.
At 56, the flag FLAG1 is reset to 0 corresponding to the end of the shift, the flag FLAG4 is reset to 0, and the learning control for correcting the data of the correction amount table in the RAM shown in FIG. 7 is executed. FLAG2 is 1
Set to.

While the gear shifting is completed in this way and the gear shifting is not performed thereafter, the control proceeds to step 57 through steps 40 to 43.
Since FLAG2 = 1 is set as described above, step 58 is selected and the previous data of the line pressure control solenoid drive duty correction amount ΔD shown in FIG. 7 is corrected and updated by the following learning control.

In step 58, the learning control sub-program shown in FIG. 5 is executed. First, in step 60, it is checked whether FLAG3 = 1 or not. If FLAG3 = 1 is not satisfied, the immediately preceding gear change controls the engine output. Since it is the type to be performed and the control has not been performed, the routine proceeds to step 61, where it is checked whether or not the last shift was an upshift shift. And if it is not an upshift,
Since the learning control is not performed as described above, the process is ended. On the other hand, in the case of an upshift shift, in step 62, shift shock prevention and a friction element are performed in the shift with the output torque of the engine 1 slightly reduced in this embodiment. Target value of inertia phase time corresponding to the desired line pressure to prevent life reduction (varies depending on the type of shift and throttle opening)
_T2S is looked up from the inertia phase time target value table in RAM, and in step 63, the line pressure control solenoid drive duty corresponding to the throttle opening TH is calculated from the correction amount table corresponding to the type of gear shift described above. The correction amount ΔD is looked up, and in step 64, the inertia phase time T ₂ is compared with the target value T _2S .

Then, as a result of the comparison in step 64, when T ₂ matches 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 and the life is shortened due to the sliding of the friction element. Therefore, by executing steps 65 and 66, the correction amount Δ
The table data in the RAM of D is increased by 0.2% and used for line pressure control during the next shift. Therefore, during the next line pressure control, the line pressure control solenoid drive duty D + ΔD
Is increased by 0.2% compared to 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 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 66, 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. be able to.

On the other hand, if FLAG3 = 1 in step 60, the measured T
The value of _{2 is} the case where the engine output control is a type of gear shift that is not performed, whereas the value of ₂ is the inertia phase time target value T _2S in this embodiment.
Is suitable for gear shifts for which engine output control is performed as described above, and because the transitional engagement capacity of the friction element is small in gear shifts for which engine output control is performed, even when the same throttle opening is used, As shown by the broken line in FIG. 8, the inertia phase time T ₂ becomes shorter than when the engine output control shown by the solid line is not performed. Therefore, if the learning control is executed as it is, the inertia phase time is measured even if the line pressure is originally proper. Since the value T ₂ becomes larger than the target value T _2S , the correction amount ΔD is excessively increased, and as a result, the line pressure during shifting is excessively increased as shown by a broken line in FIG. 9 to cause a shift shock. Become.

Therefore, in this case, in order to prevent the above-mentioned erroneous learning, the table data of the correction amount ΔD is not corrected, and this sub program is finished and the process returns to step 58.

Then, thereafter, in step 59, 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 such an 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 (inertia) irrespective of individual difference of the automatic transmission and aging. Continue to correct the 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 friction element life or a large shift shock under any circumstances. be able to.

Moreover, according to the device of this example, the inertia phase time target value that is suitable for the shift for which the engine output control is performed is used for the learning control, and the measurement is performed during the shift for which the engine output control is the type and the control is not performed. Since the learning control is not performed during the inertia phase time, it is possible to prevent the erroneous learning due to the engine output difference at the time of gear shift and always make the line pressure control proper during gear shift.

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 whether or not the learning control is possible is performed. The determination may be made.
That is, in the case of downshift gear shifting, increasing the output of the driving source during gear shifting can reduce gear shifting shock,
In this case, the target value of the inertia phase time adapted to the speed at which the drive source output is increased is used, and the learning control is not performed if the control is not performed by the drive source side. By doing so, erroneous learning can be prevented, and the same effect as in the above-described embodiment can be obtained in the case of downshift gear shifting.

(Effects of the Invention) Thus, according to the line pressure control device of the present invention, when the type of the shift for which the inertia phase time is measured is the type for which the drive source output control is performed, it corresponds to the type of the shift. Since the learning control based on the measured inertia phase time is performed only when the target condition setting condition of the inertia phase time is met, erroneous learning by using the measured value of the inertia phase time under the condition different from the target value setting condition Therefore, the control of the line pressure during the shift can be always made proper.

[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 5 are shift control computers in the same example. 6 is a flow chart showing a line pressure control and shift control program of FIG. 6, FIG. 6 is a characteristic diagram of a line pressure control solenoid drive duty, and FIG. 7 is a RAM for a moment regarding the correction amount of the same duty.
Fig. 8 is a diagram showing the data in Fig. 8, Fig. 8 is a diagram showing the relationship of the timer measurement time with respect to the line pressure control solenoid drive duty during shifting, and Fig. 9 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 water temperature sensor

Claims (1)

[Claims] Claim: What is claimed is: 1. Various friction elements of a speed change gear mechanism are selectively hydraulically actuated by line pressure to select a predetermined speed stage, and by changing the friction element to be operated, shifting to another speed stage is performed. Input speed and output of the speed change gear mechanism of an automatic transmission configured to perform drive source output control that makes the output of the drive source that drives the speed change gear mechanism different during shifting and during non-shifting, depending on the type The rotation speed is detected by the input rotation sensor and the output rotation sensor, respectively, and based on the signals from these sensors, the inertia phase time measuring means changes the gear ratio represented by the ratio between the input and output rotation speeds. I measured the inertia phase time,
In a line pressure control device, wherein the line pressure adjusting means controls the line pressure during the shift so that the inertia phase time becomes a target value according to the type of shift, the shift in which the inertia phase time is measured is the drive source. From the drive source output non-control signal output means, which is of a type that performs output control, and which outputs a signal indicating that the shift is not performed by the drive source output control, and the drive source output non-control signal output means. Line regulation control means for regulating the control of the line pressure during the gear shift based on the inertia phase time of the line pressure regulating means, based on the signal apparatus.