JPH08178039A - Control device for hydraulic actuation type transmission - Google Patents

Abstract

PURPOSE: To control the feed oil pressure of a friction coupling element at the optimum value and reduce a speed change shock by obtaining the driving force during a speed change and the driving force on the assumption of no speed change, multiplying the difference of them by the gear ratio, and obtaining the coupling capacity of the friction coupling element on the coupling side in the torque phase. CONSTITUTION: An ECU detects the value corresponding to the actual output shaft torque of a transmission T during a speed change for controlling the transmission T making the speed change by switching the coupling state of clutches C1-C3, C4R as friction coupling elements. The ECU predicts the value corresponding to the output shaft torque at no speed change based on the change of the value corresponding to the output shaft torque until the actual speed change is started, obtains the difference between the torque detected value and the torque predicted value, obtains the coupling capacity of a friction coupling element to be shifted to the coupled state in consideration of the obtained torque difference and the difference of the speed change ratio before and after the speed change, controls the switching of the friction coupling element in response to the coupling capacity, and suppresses a speed change shock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a hydraulically actuated transmission, and more particularly to a hydraulically actuated transmission for a vehicle, in which the engagement force (capacity of a clutch on the engagement side in the torque phase during gear shifting is changed). ) Is accurately detected without using a hydraulic pressure detection means, and thus the hydraulic pressure supplied to the frictional engagement element can be optimally controlled to reduce the shift shock.

[0002]

2. Description of the Related Art Conventionally, in order to prevent a shock at the time of gear shifting of a hydraulically operated transmission, it has been an object to optimally control the hydraulic pressure supplied to friction engagement elements such as clutches and brakes during gear shifting. The technology is known. For example, in Japanese Unexamined Patent Publication No. 62-159842, in order to properly control the engagement state of the friction engagement element, the hydraulic pressure in the hydraulic control device is detected, and the detected value is compared with a target value to control hydraulic pressure. A technique for correcting is disclosed.

[0003]

In this type of control, the control hydraulic pressure may be the line pressure which is the original pressure, or the hydraulic pressure in the oil passage located immediately before the friction engagement element. Here, when the frictional engagement element is a rotating frictional engagement element, that is, a so-called hydraulic clutch, even if the hydraulic pressure detected in the prior art is, for example, zero, the hydraulic oil remaining in the piston chamber of the hydraulic clutch ( Centrifugal force acts on ATF) and centrifugal hydraulic pressure is generated to press the clutch piston.

That is, the detected hydraulic pressure and the actual hydraulic pressure in the piston chamber differ greatly, and as a result, the control hydraulic pressure or its correction value does not become an appropriate value, and the engagement force (capacity) of the frictional engagement element is reduced. There was a problem in that the amount of co-engagement could not be optimally controlled outside of the desired value, and a shift shock would occur. Moreover, since the hydraulic pressure sensor is expensive, it is disadvantageous in terms of cost.

Therefore, an object of the present invention is to eliminate the above-mentioned inconvenience, and without using a hydraulic sensor,
A hydraulically-operated gear shift that can properly estimate the engagement force (capacity) of the friction engagement element at the time of gear shifting and optimally control the hydraulic pressure supplied to the friction engagement element to effectively reduce gear shift shock. To provide a control device for the machine.

[0006]

In order to solve the above-mentioned object, the present invention provides a plurality of friction engagement elements according to claim 1, and inputs and outputs by switching engagement states of the friction engagement elements. In a hydraulically actuated transmission capable of establishing different gears between shafts, torque detection means for detecting a value corresponding to an actual output shaft torque of the transmission during gear shifting, and actual gear shifting are started. From a change in the value corresponding to the output shaft torque up to, a torque predicting unit that predicts a value corresponding to the output shaft torque when no gear shift occurs, a detection value of the torque detecting unit, and a predicted value of the torque predicting unit. A torque difference calculation means for obtaining a difference between the torque difference calculation means, and an engagement force calculation means for obtaining an engagement capacity of a friction engagement element that shifts to an engagement state at the time of gear shifting, based on a result calculated by the torque difference calculation means. Equipped with It was constructed as.

According to another aspect of the present invention, the engagement force calculating means includes a frictional engagement element that shifts to an engagement state by taking into consideration the difference between the gear ratios before and after the gear shift in the result calculated by the torque difference calculating means. It was constructed so as to obtain the engagement capacity.

[0008]

In the hydraulically actuated transmission according to the first aspect of the present invention, a value corresponding to the actual output shaft torque of the transmission during a shift is detected, and the output shaft torque until the actual shift is started is detected. The value corresponding to the output shaft torque when a gear shift does not occur is predicted from the change in the corresponding value, the difference between the detected value and the predicted value is obtained, and based on this, the friction that shifts to the engaged state during the gear shift. Since the engagement capacity of the engagement element is obtained, the engagement capacity (force) of the friction engagement element can be obtained without using a hydraulic pressure sensor, and thus the hydraulic pressure supplied to the friction engagement element can be optimally controlled. It is also possible to reduce shift shock. Here, the "friction engagement element" means a clutch, a brake or the like.

More specifically, the engagement capacity is more specifically defined in claim 2.
As described in the section above, the engagement capacity of the frictional engagement element that shifts to the engaged state is calculated in consideration of the difference between the torque ratio and the speed ratio before and after the speed change.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an overall schematic view of a control device for a hydraulically actuated transmission according to the present invention.

Explaining below, an automatic transmission T for a vehicle
Is a main shaft MS connected to the crankshaft 1 of the internal combustion engine E via a torque converter 2 having a lockup mechanism L, and a countershaft CS connected to the main shaft MS via a plurality of gear trains. Prepare

The main shaft MS supports a main first speed gear 3, a main second speed gear 4, a main third speed gear 5, a main fourth speed gear 6 and a main reverse gear 7. The counter shaft CS has a counter first speed gear 8 meshing with the main first speed gear 3, a counter second speed gear 9 meshing with the main second speed gear 4, a counter third speed gear 10 meshing with the main third speed gear 5, A counter fourth speed gear 11 meshing with the main fourth speed gear 6 and a counter reverse gear 12 connected to the main reverse gear 7 via a reverse idle gear 13 are supported.

In the above description, when the main first speed gear 3 rotatably supported by the main shaft MS is connected to the main shaft MS by the first speed hydraulic clutch C1, the first speed gear stage is established. The 1st-speed hydraulic clutch C1 is 2nd-4th speeds.
The counter first speed gear 8 is supported via the one-way clutch COW because the counter first speed gear 8 is held in the engaged state even when the high speed shift stage is established. When the main second speed gear 4 rotatably supported on the main shaft MS is connected to the main shaft MS by the second speed hydraulic clutch C2, the second speed gear stage is established. When the counter third speed gear 10 rotatably supported by the counter shaft CS is connected to the counter shaft CS by the third speed hydraulic clutch C3, the third speed is established.

With the counter fourth speed gear 11 rotatably supported on the counter shaft CS being coupled to the counter shaft CS by the selector gear SG, the main fourth speed gear 6 rotatably supported on the main shaft MS is set to four.
Main shaft M with hydraulic clutch C4R for speed-reverse
When connected to S, the fourth gear is established. With the counter reverse gear 12 rotatably supported on the counter shaft CS being coupled to the counter shaft CS by the selector gear SG, the counter reverse gear 7 rotatably supported on the main shaft MS is used for the fourth speed-reverse. When the hydraulic clutch C4R is connected to the main shaft MS, the reverse shift speed is established. In the above, the clutch C1,
C2, C3 and C4R correspond to friction engagement elements, and in the case of the embodiment, they are hydraulic clutches that rotate, and are provided with a check valve (not shown) for discharging centrifugal hydraulic pressure.

The rotation of the counter shaft CS is
It is transmitted to the differential D via the final drive gear 14 and the final driven gear 15, and then to the drive wheels W, W via the left and right drive shafts 16, 16.

Here, the intake passage of the internal combustion engine E (not shown)
A throttle opening sensor S1 for detecting the opening θTH is provided near the throttle valve (not shown) arranged in the position. Also, near the final driven gear 15,
A vehicle speed sensor S2 that detects the vehicle speed V from the rotational speed of the final driven gear 15 is provided. Further, a crank angle sensor S3 for detecting the engine speed Ne from the rotation of the crankshaft 1 is provided near the crankshaft 1.

An input shaft rotation speed sensor S4 for detecting the input shaft rotation speed NM of the transmission is provided near the main shaft MS through rotation thereof, and the transmission shaft rotation sensor S4 is provided near the counter shaft CS through rotation thereof. An output shaft rotation speed sensor S5 for detecting the output shaft rotation speed NC is provided. Further, P, R, N, D4, D3, and P3 are located near the shift lever (not shown) mounted on the floor of the vehicle driver's seat.
A shift lever position sensor S6 for detecting the position selected by the driver among the seven types of positions 2 and 1 is provided.

A torque meter S for detecting the driving force (driving torque) TDS is provided near the drive shaft 16.
7 is provided. The outputs of these sensors S1 etc. are EC
U (electronic control unit).

The ECU includes a CPU 17, a ROM 18 and a RAM
The microcomputer 19 is composed of 19, an input circuit 20, and an output circuit 21, and the output of the sensor S1 and the like is input into the microcomputer via the input circuit 20. In the microcomputer, the CPU 17 determines the shift position (shift stage), and through the output circuit 21, the shift solenoid SL of the hydraulic control circuit O.
By energizing / de-energizing 1 and SL2, a shift valve (not shown) is switched to release / engage a hydraulic clutch at a predetermined gear stage.

Symbols SL3 and SL4 are an ON / OFF control solenoid for the lockup mechanism L of the torque converter 2 and a capacity control solenoid. In addition, the symbol S
L5 is a linear solenoid for clutch hydraulic pressure control.

FIG. 2 is a flow chart showing the operation of the control device for the hydraulically actuated transmission according to the embodiment.
Is a timing that indicates the clutch engagement capacity, etc.
It is a chart.

Before entering the explanation of the figure, the operation will be summarized. As described above, since centrifugal hydraulic pressure is generated in the case of the hydraulic clutch, even if the hydraulic pressure in the hydraulic control device is detected. It does not necessarily indicate the actual hydraulic pressure, and causes the control value or its correction value to deviate from an appropriate value to cause a shift shock, and the hydraulic pressure sensor is expensive and the friction engagement element rotates. As described above, the detected value does not necessarily become the actual value.

Therefore, in this embodiment, the input shaft torque TT during shifting is shown in the timing chart of FIG.
Paying attention to the fact that reversing (indicated by reference character a) resembles the engagement capacity TON (indicated by reference sign b) of the engagement side clutch, that is, pulling in the output torque of the transmission is the engagement of the friction engagement element. With the recognition that it is caused by the increase in capacity, the capacity of the torque phase is estimated without using hydraulic pressure.

Referring to the flow chart of FIG. 2, the driving force (torque) during shifting, that is, the actual input shaft torque TT (t) is first calculated in S10. Here, t indicates time.

Specifically, the actual input shaft torque TT (t) is obtained as a value converted on the main shaft MS as follows. TT (t) = 2 * TDS (t) / (ifinal * ioff * [eta]) FIG. 4 shows the used parameters. Here, TDS :, torque acting on the drive shaft 16 obtained via the torque meter S7 at time t, ifinal
: Final gear ratio, η: Transmission efficiency (for example, 0.9 in consideration of various losses such as stirring resistance).

In FIG. 4, TON: engagement capacity of the engaging side clutch, TOFF: engagement capacity of the releasing side clutch, TIN:
Torque acting on the transmission input shaft (main shaft MS), TOUT: Torque acting on the transmission output shaft (counter shaft CS), ion: Destination gear ratio, ioff
: Indicates the gear ratio of the current gear stage. In addition, the reason for multiplying 2 in the formula is that it is assumed that the torque output from the transmission is evenly transmitted to the left and right drive shafts.

Next, in S12, the input shaft torque TE (t) is calculated on the assumption that no gear shift has occurred, that is, when no gear shift has occurred.

The input shaft torque TE is obtained by multiplying a torque ratio (amplification factor of the torque converter 2) by a value retrieved from the detected engine speed and engine load such as intake pressure or throttle opening according to a predetermined characteristic, and calculating the torque phase. It is obtained by calculating the transmission input torque at the start point. The input torque TE after that time is obtained by linear interpolation as shown in the figure.
The input torque TE may be calculated by multiplying the detected drive shaft torque TDS by the gear ratio.

Next, in S14, TE obtained in S12 is calculated.
TT (t) obtained in S10 is subtracted from (t) to obtain the difference TONa between them.
(t) is obtained, and the process proceeds to S16, and the obtained difference is multiplied by the gear ratio to obtain the engagement capacity Ton (t) of the friction engagement element on the engagement side.

That is, in the torque phase, as described above, the driving force TT (t) during shifting is based on the recognition that the pulling of the output torque of the transmission is caused by the increase of the engaging force of the friction engagement element. Then, the driving force TE (t) at the time of starting the actual gear shifting and assuming that the gear shifting is not performed from the driving force before that is obtained, and the difference between them, that is, the pull-in torque is obtained at any time, and The engagement capacity (torque transmission capacity) TON (t) of the engagement-side clutch in the torque phase (early shift) is calculated by multiplying the coefficient (difference in gear ratio) based on the type.

Specifically, it is calculated from the following equation. TON (t) = TONa (t) × ioff / (ioff−ion). ． Here, here, a coefficient based on the type of shift, that is, i in the above equation,
on and ioff are, for example, ion if shifting from 2nd speed to 3rd speed
Needless to say, indicates the third gear ratio and ioff indicates the second gear ratio.

By applying this, the torque TOUT on the output shaft is obtained as follows. TOUT = TOFF * ioff + TON * ion = (TIN-TON) * ioff + TON * ion = TIN * ioff-TON * (ioff-ion)

Further, the following relationships are established. TON = (TIN * ioff-TOUT) / (ioff-ion). . TOUT = TT (t) x ioff. . TIN = TE (t). . Therefore, is derived from the equation.

In this embodiment, as described above, the driving force and the gear shift during the gear shift are recognized with the recognition that the pulling of the output torque of the transmission at the initial stage of the gear shift is caused by the increase of the engaging force of the friction engagement element. If the driving force is assumed not to be performed, the driving force is calculated, then the difference between the two is calculated, and the difference in the gear ratio based on the type of shift is multiplied to calculate the engagement capacity of the frictional engagement element on the engagement side in the torque phase. Since this is done, the capacity on the engagement side in the torque phase can be accurately obtained without using an expensive hydraulic sensor. Therefore, it is possible to optimally control the hydraulic pressure supplied to the friction engagement element, and it is possible to reduce shift shock.

Although this application has been described by taking the hydraulically actuated transmission as an example, it can be applied to other types of automatic transmissions.

[0037]

In the control device for the hydraulically actuated transmission according to the first aspect of the present invention, the engagement capacity (force) of the frictional engagement element can be obtained without using a hydraulic pressure sensor. It is also possible to reduce the shift shock by optimally controlling the hydraulic pressure supplied to the elements.

In the hydraulically actuated transmission control device according to the second aspect of the present invention, the engagement capacity (force) of the friction engagement element can be obtained with higher accuracy.

[Brief description of drawings]

FIG. 1 is an explanatory diagram generally showing a control device for a hydraulically actuated transmission according to the present invention.

FIG. 2 is a flow chart showing the operation of the apparatus shown in FIG.

FIG. 3 is a timing chart for explaining the calculation work of the flow chart of FIG.

FIG. 4 is an explanatory diagram showing parameters used for calculation work of the torque transmission capacity on the engagement side in the flow chart of FIG. 2;

[Explanation of symbols]

 E Internal combustion engine T Transmission O Hydraulic control circuit C1, C2, C3, C4R Clutch (friction engagement element)

Claims (2)

[Claims] 1. A hydraulically actuated transmission comprising a plurality of friction engagement elements, wherein different gears can be established between the input and output shafts by switching the engagement state of the friction engagement elements, wherein: ． Torque detection means for detecting a value corresponding to the actual output shaft torque of the transmission during speed change, b. Torque predicting means for predicting a value corresponding to the output shaft torque when the gear shift does not occur from the change in the value corresponding to the output shaft torque until the actual gear shift starts, c. Torque difference calculation means for obtaining a difference between the detected value of the torque detection means and the predicted value of the torque prediction means, and d. Based on the result calculated by the torque difference calculation means,
A control device for a hydraulically actuated transmission, comprising: engagement force calculating means for determining an engagement capacity of a friction engagement element that shifts to an engaged state during a gear shift. 2. The engagement force calculation means obtains the engagement capacity of the frictional engagement element that shifts to the engagement state in consideration of the difference between the gear ratios before and after the gear shift, based on the result calculated by the torque difference calculation means. The control device for the hydraulically actuated transmission according to claim 1.