JP2615889B2 - Line pressure control device for automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line pressure control device for an automatic transmission, and more particularly to a device for appropriately controlling a line pressure during a gear shift.

(Prior Art) An automatic transmission employs various types of friction elements (clutches, brakes, etc.) of a transmission gear mechanism by selectively hydraulically operating a line pressure to select a predetermined shift speed and change the operated friction elements. The shift to the next gear is performed.

For this reason, if the line pressure is too high, the transient engagement capacity of the friction element becomes excessively large, causing a large shift shock.If the line pressure is too low, the transient engagement capacity of the friction element becomes excessively small and the friction element slips. As a result, the life is shortened. Accordingly, it is necessary to appropriately control the line pressure. Conventionally, for example, as described in “Automatic Transmission RE4R01A Model Maintenance Manual” (A261C07) issued by Nissan Motor Co., Ltd. The line pressure is controlled by determining the drive duty of the line pressure control solenoid based on the engine throttle opening from each of the different table data.

However, in such a conventional line pressure control device,
Line pressure control solenoid has product variation,
When the characteristics change over time, or when the friction element has a variation in the product or when the friction material changes over time, the line pressure deviates from the proper value even with the same solenoid drive duty in the former case, and the line pressure in the latter case. Even if the pressure is controlled as intended, it may not be an appropriate value for the friction element, and in any case, excessive or insufficient line pressure may cause a large shift shock or shorten the life of the friction element.

Incidentally, for example, as shown in FIG. 10, a case where the automatic transmission of the document by a reduction in engine throttle opening degree upshift from the first speed to the second speed OFF the shift solenoid from ON instantaneously t ₁ As can be seen, when the line pressure is low, the second speed selection pressure, which is based on the line pressure, rises as shown by the solid line to engage and advance the corresponding friction element, and the input / output rotation speed ratio N _T / The gear ratio represented by N _O N _T : input speed, N _O : output speed changes from the first speed equivalent value to the second speed equivalent value as shown by the solid line, and the transmission output torque changes as shown by the solid line. On the other hand, when the line pressure is high, the operation waveform becomes as shown by the dotted line. Therefore, it can be determined from the time during which the gear ratio N _T / N _O is changing, that is, the inertia phase time T, whether or not the line pressure is an appropriate value in consideration of the above-mentioned variation and aging. From this viewpoint, 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. Detecting, based on signals from those sensors, the inertia phase time measuring means measures the time during which the gear ratio represented by the ratio between the input and output rotational speeds is changing, and the line pressure adjusting means, A line pressure control device that controls the line pressure during the shift so that the inertia phase time becomes a target value has been proposed. According to such a device, it is possible to constantly perform line pressure control according to the actual situation of the automatic transmission. In addition, it is possible to avoid occurrence of a large shift shock and a shortened life of the friction element due to excessive or insufficient line pressure.

(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, a vehicle equipped with the above automatic transmission also includes an air conditioner, and an output shaft of an engine which is a drive source of the automatic transmission can be connected to a compressor of the air conditioner via a clutch. In this case, during the operation of the air conditioner, the clutch is engaged and a part of the output of the engine is used for driving the compressor. Therefore, even when the throttle opening of the engine is the same, during the operation of the air conditioner, The drive input of the automatic transmission is reduced as compared to when the automatic transmission is not operating.

Further, when the vehicle equipped with the automatic transmission also includes a power steering device, and the output shaft of the engine, which is the drive source of the automatic transmission, is also coupled to the oil pump of the power steering device, A part of the output of the engine is used to drive the oil pump during the turning of the wheel, and therefore, even when the engine throttle opening is the same, the power steering device is not operated during the turning of the steering angle by a certain degree or more. The drive input of the automatic transmission decreases as compared with the middle.

Further, even when the engine is operating in an extremely low atmospheric pressure state, such as when the vehicle equipped with the automatic transmission runs in a mountainous area at a high altitude, even when the engine throttle opening is the same, the engine is operated under the normal atmospheric pressure. , The drive input of the automatic transmission decreases.

The characteristics of the drive input of the automatic transmission with respect to the engine throttle opening (the drive input increases as the throttle opening increases) show that the engine operates under the normal atmospheric pressure, and only the auxiliary equipment for the operation of the automatic transmission operates. If the characteristic of the other drive is changed as in the above case, the required amount of the transient engagement capacity of the friction element is changed, so that the measured inertia phase time is also different from the case of the characteristic in the normal state. It will be.

However, the above-described conventional line pressure control device determines the target value of the inertia phase time only in accordance with the type of shift and the throttle opening so as to be suitable at the time of shift in the case of the normal drive input characteristic, For this reason, in the conventional device, as described above, the learning control is performed even with the measured value of the inertia phase time at the time of shifting when the drive input characteristic fluctuates from that at the normal time, and as a result, a shift shock occurs. May not be sufficiently prevented.

The present invention provides an apparatus that advantageously solves this problem.

(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 a line pressure to a predetermined gear position. , The input rotation sensor and the output rotation sensor of the automatic transmission, wherein the input gear and the output gear of the transmission gear mechanism of the automatic transmission configured to shift to another gear by changing the operating friction element. The inertia phase time, which is the time during which the gear ratio represented by the ratio between the input and output rotation speeds is detected, is measured by the inertia phase time measuring means based on the signals from the sensors, and the line pressure adjustment is performed. Means for learning and controlling the line pressure during the shift so that the inertia phase time becomes a target value. A characteristic of a drive input of the automatic transmission with respect to an engine load of an engine driving the automatic transmission, which is caused by at least one of operation of a water steering device and engine operation under low atmospheric pressure. Engine load-drive input characteristic change detecting means for detecting a change from a predetermined engine load-drive input characteristic, which is a precondition for the target value of the inertia phase time, and based on the detection result of the engine load-drive input characteristic change detecting means. A control for prohibiting the line pressure adjusting means from learning control of a line pressure during a shift based on the inertia phase time when a characteristic of a drive input of the automatic transmission fluctuates from the predetermined engine load-drive input characteristic. And an availability determining means.

(Operation) In such an apparatus, the transmission gear mechanism selectively hydraulically operates various frictional elements by the line pressure to select a predetermined gear, and to increase / decrease the supplied power at this gear to output.
The speed change gear mechanism is shifted to another speed by changing the friction element that is hydraulically operated.

During this time, the input rotation sensor and the output rotation sensor detect the input rotation speed and the output rotation speed of the transmission gear mechanism, respectively. The inertia phase time measuring means measures 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, that is, the inertia phase time during the shift, based on the signals from these two sensors. . The line pressure adjusting means learns and controls the line pressure during shifting so that the inertia phase time becomes a target value.

On the other hand, the engine load-drive input characteristic fluctuation detecting means
Automatic operation of the engine that drives the automatic transmission due to at least one of operation of the compressor of the air conditioner, operation of the power steering device, and operation of the engine under low atmospheric pressure. If the characteristics of the drive input of the machine have fluctuated from a predetermined engine load-drive input characteristic which is a prerequisite for the target value of the inertia phase time, the change is detected, and the shift obtained by measuring the inertia phase time causes the fluctuation. And outputs a signal indicating whether or not the shift is performed in a state in which the automatic transmission is operating. Based on the detection result of the engine load-drive input characteristic variation detection unit, the control input / output determination unit determines whether the drive input characteristic of the automatic transmission is Learning control of the line pressure during shifting based on the inertia phase time of the line pressure adjusting means when the predetermined engine load-drive input characteristic fluctuates. Prohibition to.

Therefore, according to this device, even if the line pressure control element has a product variation, the characteristics change over time, or the friction element has a product variation, or the friction material changes over time. However, it is possible to perform line pressure control in consideration of individual differences and changes over time of these automatic transmissions, and it is possible to avoid occurrence of a large shift shock and a shortened life of a friction element due to excessive or insufficient line pressure. Of course, due to at least one of the operation of the compressor of the air conditioner, the operation of the power steering device, and the operation of the engine under low atmospheric pressure, the engine load-drive input characteristic of the automatic transmission becomes If there is a variation from a predetermined engine load-drive input characteristic which is a prerequisite for the target value of the inertia phase time, the line pressure adjusting means performs an operation based on the inertia phase time. Since the learning control of the line pressure during the speed is prohibited, and the learning control is performed only when the shift is performed with the engine load-drive input characteristic of the automatic transmission being the predetermined engine load-drive input characteristic, the inertia phase It is possible to prevent learning that may not be sufficiently appropriate using measurement values under conditions different from the prerequisites for the time target value, and it is possible to always make learning control relating to line pressure during gear shifting appropriate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

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

The engine 1 includes an engine control computer 5,
The computer signal from a throttle sensor 8 for detecting signals from an engine speed sensor 6 for detecting an engine speed N _E, a signal from a vehicle speed sensor 7 for detecting a vehicle speed V, an engine throttle opening degree 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. Computer 5 supplies or commands it to the engine 1 determines the fuel injection pulse width T _P on the basis of these input information, a not shown ignition timing control signal to the engine 1. Engine 1 is supplied with fuel in an amount corresponding to the fuel injection pulse width T _P, operated by combusting the fuel in timed with the rotation of the engine.

The automatic transmission 2 includes a torque converter 10 and a transmission 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 increased / decreased according to the selected shift speed of the transmission gear mechanism 11, reaches the output shaft 13, and reaches the drive wheels 4 via the differential gear 3 from the output shaft to allow the vehicle to travel. it can.

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

Here, a shift control computer 14 and a control valve 15 are provided for this shift control. The computer 14 selectively turns on the shift control shift solenoids 15a and 15b in the control valve 15, and selectively connects various friction elements so that the corresponding shift speed is selected by a combination of ON and OFF of the shift solenoids. Supply pressure P _L to control shift control. The shift control computer 14 also performs duty control of the line pressure control duty solenoid 16 in the control valve 15 with the drive duty D to obtain the line pressure P _L in the control valve 15 (the line pressure increases as the duty D increases). Control shall be performed as intended by the invention. Signal from the vehicle speed sensor 7 is in the shift control and the line pressure control for the computer 14, addition to the signal respectively input from the throttle sensor 8, the rotational speed N _T of the shaft 12
And a signal from an output rotation sensor 18 that detects the number of rotations 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, such a cooling device 19 to sense it when in operation, even if the signal A _C from a cooling device operation switch 23 is input to the shift control computer 14.

The vehicle herein further includes a power steering device 24 that applies a steering assist force to a steering device that steers a steering wheel (not shown) by turning a steering wheel (not shown), and an oil pump that is a hydraulic source of the power steering device 24. 25 is drivingly coupled to the output shaft of the engine 1 via a pulley 26 and the belt 22. The power steering device 24 is operated by the oil pump 25 to discharge while the steering reaction force against the steering of the steering wheel is small. By draining the oil, the driving force of the oil pump 25 is reduced, and when the steering angle of the steering wheel increases and the steering reaction force increases, the operating oil pressure is generated by the oil pump 25 by switching a valve (not shown). A steering assist force is provided from the operating oil 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.

Additionally here, the shift control computer 14, also inputs signals from the atmospheric pressure sensor 27 for detecting the atmospheric pressure A _P.

The computer 14 executes the control programs shown in FIGS. 3 to 5 to perform the line pressure control and the shift control.

First, a description will be given of the line pressure control program of FIG. 3 which is repeatedly executed by the periodic interruption. In step 30, it is checked whether or not a later-described flag FLAG1 is "1" to determine whether or not a shift is being performed. As a result, if the shift is not in progress (FLAG1 = 0), in step 31, a line corresponding to the throttle opening TH is obtained from the non-shift duty table 1 having a characteristic as shown by a solid line A in FIG. the pressure control solenoid drive duty D and table look-up, then the drive duty D is output to the solenoid 16 in step 32, controls 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 shift is in progress (FLAG1 = 1), in step 33, the speed differs depending on the type of shift, such as the shift speed, upshift / downshift, etc. This is also indicated by the dotted line B in FIG. The line pressure control solenoid drive duty D corresponding to the throttle opening TH is looked up in a table from the shift table 2 having the characteristic shift, and then, in step 34, the shift is increased due to excessive line pressure, in particular, shift shock is likely to occur. It is checked whether or not the shift is a shift, and if it is not an upshift, the apparatus of this example outputs the drive duty D to the solenoid 16 as it is in step 32. On the other hand, in the case of an upshift, in step 35, for example, the seventh control which is written in the RAM for each type of shift by learning control described later.
A line pressure control solenoid drive duty correction amount Δ corresponding to the throttle opening TH from a correction amount table as shown in the figure.
D is looked up and then at step 36 D + ΔD
The output to the solenoid 16 to control the line pressure P _L to the value for the shift.

Next, a description will be given of the shift control and the line pressure control solenoid drive duty correction amount control of FIG. 4 which are also repeatedly executed by the periodic interruption. First, at step 40, it is determined whether or not FLAG1 is 1; Is checked, and if the vehicle is not shifting (FLAG1 = 0), in step 41, a required gear position corresponding to a combination of the vehicle speed V and the throttle opening TH is determined based on a predetermined normal shift pattern.

In the next step 42, it is checked whether or not the gear should be shifted according to whether or not the requested gear is different from the currently selected gear. FLAG1 = 1 and solenoids 15a, 15b
Are switched to ON or OFF to execute the shift to the required gear position. Further, the current turning angle S _{A is set} to the maximum turning angle S _Amax .

When the gear is being shifted (FLAG1 = 1) in step 43, in the next control, the process proceeds from step 40 to step 44 to determine whether S _Amax . ≧ S _A, that is, the current value of the steering angle.
It is checked whether or not S _A has increased from the maximum steering angle value S _Amax . As a result, if S _A has not increased (S _Amax . ≧ S _A ), it has not changed or if it has increased (S _Amax . < S _A ), step 45
After setting S _Amax . To the increased current value S _A , the process proceeds to the next step 46. As a result, the maximum steering angle during gear shifting is peak-held at the maximum steering angle S _Amax .

In step 46, the timer T ₁ for measuring the shift time is incremented (increment), checks whether or not the next inertia phase at step 47. Hitting this check, the gear ratio gear ratio represented by input and output rotational speed ratio N _T / N _O is corresponding to the speed after the shift from the gear ratio corresponding to the speed of the previous transmission of the transmission gear mechanism 11 It is determined that the inertia phase is being changed during the change. And wherein the timer T ₂ is incremented (increment) in the inertia phase during the step 48, by skipping inertia phase after step 48, to measure the inertia phase time timer T _2.

In the next step 49, it is checked whether or not the inertia phase has been completed (the shift has been completed).
At 50, a flag for resetting the flag FLAG1 to 0 in response to the end of the shift and executing learning control for correcting data of the correction amount table in the RAM shown in FIG.
Set FLAG2 to 1.

In this manner, while the shift is terminated and thereafter no shift is performed, the control proceeds to step 51 via steps 40 to 42,
Since FLAG2 = 1 as described above, step 52 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 this step 52, the learning availability subprogram shown in FIG. 5 (a) and the learning control subprogram shown in FIG. 5 (b) are sequentially executed, and first, in step 60 of FIG. 5 (a). The maximum steering angle S _Amax . During the immediately preceding shift is equal to or greater than a predetermined value S _AS (S _Amax . ≧ S _AS ) at which a large force is required to drive the oil pump 25 of the power steering device 24. or check to a flag indicating a learning whether or not unless the result S _AS more FLAG3
Is maintained at 0 in order to perform learning control, and
On the other hand, if it is equal to or _larger than SAS, FLAG3 is set to 1 in step 62 so that learning control is not performed.

State in step 61 the cooling device operation switch 23 is checked whether the ON state by the signal A _C, a FLAG3 if not result ON state is maintained at 0, the process proceeds to step 62, if the ON state Since there is a possibility that the compressor 20 of the cooling device 19 is being driven, FLAG3 is set to 1 in step 63.

In step 62, the atmospheric pressure A _P is the output of the engine 1 by checking whether or not significantly reduced begins below a predetermined value _{A PS (A P <A PS} ), be at the result A _PS below F
The LAG3 was maintained at 0 terminated, whereas this subprogram, after setting the FLAG3 if less A _PS 1, and ends this subroutine.

Next, here, in step 70 of FIG.
If FLAG3 is not 1, the immediately preceding shift is a shift in the case where the drive input characteristic of the automatic transmission 2 with respect to the throttle opening TH is a normal characteristic. It is checked whether the immediately preceding shift was an upshift. If it is not an upshift, the learning control is not performed as described above, so the process ends.
On the other hand, in the case of an upshift, the timer
It is checked whether T ₁ , that is, the shift time is equal to or more than a predetermined value T _1S . The measurement time of the timers T ₁ and T ₂ with respect to the line pressure control solenoid drive duty D + ΔD% at the time of shifting is shown by a solid line in FIG. 8 in the case of an upshift with normal drive input characteristics. When the control solenoid drive duty is extremely small, for example, α in the region where T ₁ ≧ T _1S , the line pressure is extremely low. Is too low and the frictional element is suddenly fastened due to a sudden increase in the selection pressure at the end of the shelf, so that the off-shelf shift shown by the dotted line α in FIG. (Solid lines β and chain lines γ in FIG. 9 indicate operation waveforms when the solenoid drive duty is a value indicated by the same reference numeral in FIG. 8). To prevent this off-shelf shift, step 72
If it is determined that T ₁ ≧ T _1S in step 73, the line pressure solenoid drive duty correction amount ΔD corresponding to the throttle opening TH at the time of shifting is determined from the correction amount table described above corresponding to the type of shifting in step 73. Look up and follow steps
At 74, the correction amount ΔD is greatly increased by 2%, and at a subsequent step 75, the table data in the RAM is rewritten to the correction amount ΔD so as to quickly escape from the T ₁ ≧ T _1S region.

In the T ₁ <T _1S region, since there is no such concern, the correction amount Δ
First, at step 76, a target value of inertia phase time (shift type) corresponding to a line pressure preferable for preventing shift shock and reducing the life of a friction element in shifting with normal drive input characteristics is performed. _T2S is looked up from the inertia phase time target value table in the RAM,
In step 77, the line pressure control solenoid drive duty correction amount ΔD corresponding to the throttle opening TH is looked up from the correction amount table described above corresponding to the type of shift, and in step 78, the inertia phase time T ₂ is determined. Compare with the target value _T2S .

The comparison results in step 78, when the T ₂ coincides with the T _2S without changing the table data in the RAM of the correction amount [Delta] D, is used as is in the line pressure control during the next shift. When T ₂ > T _2S , the line pressure is too low and the life is shortened due to the sliding of the friction element.
By executing steps 80 and 80, the table data in the RAM of the correction amount ΔD corresponding to the type of shift 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% from the previous time, so that the line pressure can be increased by that amount, and the line pressure can be brought close to an appropriate value to avoid a reduction in the life of the friction element. Conversely, T ₂ <T _2S
In the case of (1), the line pressure is too high and a large shift shock occurs due to the excessive engagement capacity of the friction element. Therefore, by executing steps 81 and 80, the table data in the RAM of the correction amount ΔD corresponding to the type of shift is changed to 0.2. % For use in line pressure control during the next shift. Accordingly, 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, so that the line pressure can be reduced by that amount, and the line pressure approaches an appropriate value to prevent a large shift shock. be able to.

The other hand, if in step 70 the FLAG3 = 1, the measured value T ₂ of the inertia phase time, an automatic transmission 2 with the drive input characteristics are varied, that is, the driving force is the oil pump 25 of the engine 1 is here And at least one of the driving of the compressor 20 or during a shift in a state where the atmospheric pressure is too low and the driving input is lower than normal at the same throttle opening degree,
On the other hand, as described above, the inertia phase time target value T _2S in this embodiment is suitable for the case where the gearshift is performed under the normal drive input characteristics, and furthermore, for example, when the drive input is reduced in the low drive input state. protected from the inertia-phase period T ₂ as a shift gear is shown in Figure 8 in the same throttle opening for only a small transient engagement capacity of the friction elements is shorter than that of the normal drive input characteristics, erroneous learning Therefore, the correction of the table data of the correction amount ΔD is not performed, FLAG3 is cleared to 0 in step 72, and this subprogram is finished as it is, and the process returns to step 52.

And thereafter, resets at step 53 the FLAG2 to 0, and waits for the next measurement value of the timer T _1, T ₂ is reset to 0.

By repeating such an operation (learning control), the line pressure solenoid drive duty correction amount ΔD changes the line pressure control solenoid drive duty D + ΔD during gear shifting to an appropriate value (inertia) regardless of the individual difference of the automatic transmission and the change with time. Continue to correct the phase time T ₂ to a value that will be the target value T _2S ), and control the line pressure during shifting to an appropriate value that does not cause a reduction in the life of the friction element or a large shift shock under any situation change. be able to.

In addition, according to the apparatus of this example, the inertia phase time target value suitable for the shift with the normal drive input characteristics is used for the learning control, and the inertia phase time measured during the shift with the drive input reduced. In this case, the learning control is not performed, so that erroneous learning due to the difference in the drive input characteristics at the time of shifting can be prevented, and the control of the line pressure during shifting can always be made appropriate.

As described above, the present invention has been described based on the illustrated example. However, the present invention is not limited to the above-described example. For example, the learning control is performed not only for the upshift but also for the downshift, and whether or not the learning control is possible is determined. The determination may be made.

Further, in the above-described embodiment, when the drive input characteristic of the automatic transmission 2 is a normal characteristic, that is, the drive of the engine 1 is performed to drive the cooling device 19 and the power steering device 24 as the target value T _2S of the inertia phase time. A value that is suitable for the case where no power is consumed and the atmospheric pressure is a normal pressure is used.For example, when the cooling device 19 or the power steering device 29 is driven or when the atmospheric pressure is reduced in high altitudes. The target value may be set so as to conform to a state in which the drive input is reduced, such as at the time. In such a case, in the subprogram shown in FIG.
If the case of YES and NO is exchanged, the learning control is not performed when the preconditions of the target value and the measured value of the inertia phase time do not match, because the characteristics fluctuate in the direction in which the drive input increases. As a result, the same effects as in the previous embodiment can be obtained.

(Effects of the Invention) Thus, according to the line pressure control device of the present invention, the engine load-drive input characteristic of the automatic transmission is in a state of the predetermined engine load-drive input characteristic which is a precondition for the target value of the inertia phase time. Since the learning control is performed only when the shift is performed, the measurement value under the condition different from the precondition of the target value of the inertia phase time is used. Learning that may not be sufficiently appropriate can be prevented, and learning control on the line pressure during shifting can always be made appropriate.

[Brief description of the drawings]

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 one embodiment of the device of the present invention, and FIGS. 3 to 5 are shift control computers in the example. FIG. 6 is a characteristic diagram of a line pressure control solenoid drive duty, and FIG. 7 is an instantaneous RAM relating to a correction amount of the duty.
8 is a diagram illustrating the relationship between the line pressure control solenoid drive duty during shifting and the timer measurement time, and FIG. 9 is a diagram illustrating the solenoid drive duty indicated by α, β, and γ in FIG. FIG. 10 is a shift operation time chart showing a state of occurrence of an inertia phase during a shift operation. DESCRIPTION OF SYMBOLS 1 ... Electronic control fuel injection engine 2 ... Automatic transmission 3 ... Differential gear 4 ... Drive wheel 5 ... Computer for engine control 6 ... Engine rotation sensor 7 ... Vehicle speed sensor 8, Throttle sensor 9 ... … Intake air amount sensor 10 …… Torque converter 11 …… Transmission gear mechanism 14 …… Transmission control computer 15 …… Control valves 15a, 15b …… Transmission 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 operation switch 24 Power steering device 25 Oil pump 26 Steering angle sensor 27 Atmospheric pressure sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display F16H 59:62

Claims (1)

(57) [Claims] 1. An automatic transmission in which various frictional elements of a transmission gear mechanism are selectively hydraulically operated by a line pressure to select a predetermined gear position, and a shift to another gear position is performed by changing an operating friction element. An input rotation sensor and an output rotation sensor respectively detect an input rotation speed and an output rotation speed of the transmission gear mechanism of the transmission, and are represented by a ratio between the input and output rotation speeds based on signals from those sensors. The inertia phase time measuring means measures the inertia phase time, which is the time during which the gear ratio is changing, and the line pressure adjusting means learns and controls the line pressure during the shift so that the inertia phase time becomes a target value. In the control device, at least one of the operation of the compressor of the air conditioner, the operation of the power steering device, and the operation of the engine under low atmospheric pressure. The variation of the characteristic of the drive input of the automatic transmission with respect to the engine load of the engine that drives the automatic transmission from the predetermined engine load-drive input characteristic as a precondition for the target value of the inertia phase time due to An engine load-drive input characteristic variation detecting means for detecting, and a drive input characteristic of the automatic transmission varies from the predetermined engine load-drive input characteristic based on a detection result of the engine load-drive input characteristic variation detection means. And controllability determining means for prohibiting learning control of the line pressure during shifting based on the inertia phase time of the line pressure adjusting means. apparatus.