JP3304657B2 - Control device for hydraulically operated transmission - Google Patents

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 operated transmission, and more particularly, to an engagement force (capacity) of an engagement side clutch in a torque phase during a shift in a hydraulically operated transmission for a vehicle. The present invention relates to a control device for a hydraulically operated transmission which can accurately detect the shift pressure without using a hydraulic pressure detecting means, thereby reducing the shift shock by optimally controlling the supply hydraulic pressure of the friction engagement element.

[0002]

2. Description of the Related Art Conventionally, an object of the present invention is to optimally control the hydraulic pressure supplied to frictional engagement elements such as clutches and brakes during gear shifting in order to prevent shocks during shifting of a hydraulically operated transmission. The technology is known. For example, in Japanese Patent Application Laid-Open 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 the hydraulic pressure. Are disclosed.

[0003]

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

[0004] That is, the detected oil pressure and the actual oil pressure in the piston chamber are greatly different. As a result, the control oil pressure or its correction value does not become an appropriate value, and the engagement force (capacity) of the friction engagement element is reduced. There was a problem that the amount of co-meshing could not be optimally controlled out of the expected value, and a shift shock occurred. Further, since the oil pressure sensor is expensive, it is disadvantageous in terms of cost.

Accordingly, an object of the present invention is to solve the above-mentioned disadvantages, and without using a hydraulic sensor.
Hydraulically actuated shift that appropriately estimates the engagement force (capacity) of the friction engagement element during gear shifting, thereby optimally controlling the hydraulic pressure supplied to the friction engagement element and effectively reducing shift shock. Machine control device.

[0006]

The present invention to solve the above object means to provide a process according to claim 1 wherein input and output by comprising a plurality of frictional engagement elements, switching the engagement state of the frictional engagement elements In a hydraulically operated transmission capable of establishing different gear stages between shafts, torque detection means for detecting a value corresponding to an actual output shaft torque of the transmission during shifting, and actual shifting starts. A torque predicting means for predicting a value corresponding to the output shaft torque when no shift has occurred, from a change in the value corresponding to the output shaft torque up to;
Frictional engagement to shift into engagement during speed change based on the calculated result of the torque difference calculation means for obtaining a difference, and the torque difference calculation means and the predicted value of the detected value and the torque predicting means of said torque detection means engaging force estimated that to estimate the capacity of engagement elements
A constant section was composed as comprising a.

[0007] In claim 2, wherein said engaging force estimated hand <br/> stage, taking into account the difference of the calculated speed change before and after the gear ratio of the result of the torque difference calculation means, moves to the engaged state the engagement capacity of the friction engagement element is configured as you estimated.

[0008]

In the hydraulically operated transmission according to claim 1, a value corresponding to an actual output shaft torque of the transmission during a shift is detected, and the output shaft torque until the actual shift starts is detected. from the change of the corresponding value, to predict a value equivalent to the output shaft torque when the shift has not occurred, determine the difference between the predicted value and the detected value, friction to shift into engagement during speed change based thereon since it is configured as you estimate the engagement capacity of application elements, without using the oil pressure sensor, it is possible to obtain the engagement capacity (power) of the frictional engagement elements, the oil pressure supplied friction engagement element with optimal Control can also reduce shift shock. Here, the “friction engagement element” means a clutch, a brake, and the like.

[0009] More specifically, the engagement capacity is more specifically defined in claim 2.
As described in the section, and configured as Ru is estimated in consideration of the difference in speed ratio before and after the shift to the torque difference.

[0010]

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

FIG. 1 is a schematic diagram showing the entire control device of a hydraulically operated transmission according to the present invention.

In the following, an automatic transmission T for a vehicle will be described.
A main shaft MS connected to a crankshaft 1 of an internal combustion engine E via a torque converter 2 having a lock-up mechanism L, and a counter shaft CS connected to the main shaft MS via a plurality of gear trains. Prepare.

A main first gear 3, a main second gear 4, a main third gear 5, a main fourth gear 6, and a main reverse gear 7 are supported on the main shaft MS. On the counter shaft CS, a counter first gear 8 meshing with the main first gear 3, a counter second gear 9 meshing with the main second gear 4, a counter third gear 10 meshing with the main third gear 5, A counter fourth gear 11 meshing with the main fourth 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 is established. 1st speed hydraulic clutch C1 is 2nd to 4th
Since the engaged state is maintained even when the gear stage is established, the first-speed counter gear 8 is supported via the one-way clutch COW. When the main second speed gear 4 rotatably supported by the main shaft MS is coupled to the main shaft MS by the second speed hydraulic clutch C2, the second speed is established. When the counter third speed gear 10 rotatably supported by the counter shaft CS is coupled to the counter shaft CS by a third speed hydraulic clutch C3, a third speed is established.

In a state where the counter fourth-speed gear 11 rotatably supported on the counter shaft CS is connected to the counter shaft CS by the selector gear SG, the main fourth-speed gear 6 rotatably supported on the main shaft MS is moved to the fourth position.
Speed-reverse hydraulic clutch C4R with main shaft M
When engaged with S, the fourth gear is established. In a state where the counter reverse gear 12 relatively rotatably supported on the counter shaft CS is coupled to the counter shaft CS by the selector gear SG, the counter reverse gear 7 rotatably supported on the main shaft MS is connected to the fourth speed-reverse gear. When the hydraulic clutch C4R is engaged with the main shaft MS, the reverse gear is established. In the above, the clutch C1,
C2, C3, and C4R correspond to the friction engagement elements. In the case of the embodiment, the clutch itself includes a rotating hydraulic clutch, and includes a check valve (not shown) for discharging the centrifugal hydraulic pressure.

The rotation of the counter shaft CS is
The power is transmitted to the differential D via the final drive gear 14 and the final driven gear 15, and then transmitted 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 in the vicinity of a throttle valve (not shown) disposed at the position. In the vicinity of the final driven gear 15,
A vehicle speed sensor S2 for detecting the vehicle speed V from the rotation speed of the final driven gear 15 is provided. Further, near the crankshaft 1, a crank angle sensor S3 for detecting the engine speed Ne from the rotation thereof is provided.

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

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

The ECU is a CPU 17, a ROM 18, a RAM
19, a microcomputer comprising an input circuit 20 and an output circuit 21. Outputs of the above-mentioned sensor S1 and the like are input into the microcomputer via the input circuit 20. In the microcomputer, the CPU 17 determines a shift position (gear position), and the shift solenoid SL of the hydraulic control circuit O through the output circuit 21.
A shift valve (not shown) is switched by exciting / de-energizing 1, SL2, and a hydraulic clutch of a predetermined gear stage is released / engaged.

Reference numerals SL3 and SL4 denote a solenoid for ON / OFF control of the lock-up mechanism L of the torque converter 2 and a capacity control solenoid. Also, 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 of the hydraulically operated transmission according to the embodiment.
Is the timing that indicates the clutch engagement capacity during shifting, etc.
It is a chart.

Before entering the description of the figure, the operation is generally summarized as described above, since a centrifugal hydraulic pressure is generated in the case of a hydraulic clutch, even if the hydraulic pressure in the hydraulic control device is detected. It does not always indicate the actual oil pressure, and the control value or its correction value may deviate from an appropriate value, causing a shift shock. In addition, the oil pressure sensor is expensive and the friction engagement element rotates. When, the detected value is not always an actual value, as described above.

Therefore, in this embodiment, the input shaft torque TT during shifting is shown in the timing chart of FIG.
Note that reversing (denoted by a) is similar to the engagement capacity TON (denoted by b) of the on-coming clutch, that is, pulling in the output torque of the transmission is performed by the engagement of the friction engagement element. With the recognition that this is caused by an increase in capacity, the capacity of the torque phase is estimated without using oil pressure.

Referring to the flowchart of FIG. 2, a driving force (torque) during shifting, that is, an actual input shaft torque TT (t) is 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) / (final × ioff × η) FIG. 4 shows the parameters used. Here, TDS: the torque acting on the drive shaft 16 obtained via the torque meter S7 at the 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 engagement side clutch, TOFF: engagement capacity of the release 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: gear ratio of the destination gear, ioff
: Indicates the gear ratio of the current gear. Further, the reason for multiplying by 2 in the equation is that it is assumed that the vehicle runs in a straight line in which the torque output from the transmission is evenly transmitted to the left and right drive shafts.

Then, the program proceeds to S12, in which the input shaft torque TE (t) is calculated assuming that no shift has occurred, that is, when no shift has occurred.

The input shaft torque TE is obtained by multiplying a value retrieved from the detected engine speed and the engine load such as the intake pressure or the throttle opening in accordance with a predetermined characteristic by a torque ratio (amplification rate of the torque converter 2). It is obtained by calculating the transmission input torque at the start. Note that the input torque TE after that point 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 a gear ratio.

Then, the process proceeds to S14, in which TE obtained in S12 is determined.
TT (t) obtained in S10 is subtracted from (t) to obtain a difference TONa between the two.
(t) is obtained, and the process proceeds to S16 to multiply the obtained difference by the gear ratio to obtain the engagement capacity Ton (t) of the frictional engagement element on the engagement side.

That is, as described above, in the torque phase, the driving force TT (t) during shifting is determined based on the recognition that the pull-in of the output torque of the transmission is caused by the increase in the engagement force of the friction engagement element. The driving force TE (t) at the start of the actual shifting and the driving force at the time of assuming that the shifting was not performed from the driving force before that is found, and the difference between the two, i.e., the pull-in torque, is found at any time. Is multiplied by a coefficient (difference in gear ratio) based on the type of the clutch to calculate the engagement capacity (torque transmission capacity) TON (t) of the engagement-side clutch in the torque phase (early shift).

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

More specifically, 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 relationship is established. TON = (TIN × ioff-TOUT) / (ioff-ion). . TOUT = TT (t) × ioff. . TIN = TE (t). . Therefore, the following is derived from the equation.

In this embodiment, as described above, the driving force during the shift and the shift are changed while recognizing that the pull-in of the output torque of the transmission at the beginning of the shift is caused by an increase in the engagement force of the friction engagement element. The driving force when it is assumed that the driving has not been performed is obtained, and then the difference between the two is obtained, and the engagement capacity of the frictional engagement element on the engagement side in the torque phase is obtained by multiplying the difference between the gear ratios based on the type of shift. With this configuration, the engagement-side capacity in the torque phase can be accurately obtained without using an expensive oil pressure sensor. Therefore, it is possible to optimally control the supply hydraulic pressure of the friction engagement element, and it is possible to reduce a shift shock.

Although this application has been described by taking a hydraulically operated transmission as an example, the present invention can be applied to other types of automatic transmissions and the like.

[0037]

According to the control apparatus for a hydraulically operated transmission according to the first aspect, the engagement capacity (force) of the friction engagement element can be obtained without using a hydraulic sensor, and thus the friction engagement can be achieved. It is also possible to reduce shift shock by optimally controlling the supply hydraulic pressure of the elements.

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

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing the operation of the apparatus in FIG. 1;

FIG. 3 is a timing chart for explaining a calculation operation of the flow chart of FIG. 2;

FIG. 4 is an explanatory diagram showing parameters used for calculating an engagement-side torque transmission capacity in the flowchart of FIG. 2;

[Explanation of symbols]

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

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 61/00-61/24

Claims (2)

(57) [Claims] 1. A hydraulically actuated transmission comprising a plurality of frictional engagement elements and capable of establishing different gears between input and output shafts by switching an engagement state of the frictional engagement elements, . Torque detecting means for detecting a value corresponding to an actual output shaft torque of the transmission during a shift; b. Torque predicting means for predicting a value corresponding to the output shaft torque when no shift has occurred, from a change in the value corresponding to the output shaft torque until the actual shift starts; c. Torque difference calculating means for calculating a difference between the detected value of the torque detecting means and the predicted value of the torque predicting means; and d. Based on the result calculated by the torque difference calculation means, the engagement capacity of the friction engagement element that shifts to the engagement state at the time of speed change is estimated.
Control device for a hydraulically operated transmission, characterized in that it comprises the engagement force estimating means Ru Teisu, the. Wherein said engagement force estimating means estimates the engagement capacity of the friction engagement elements in consideration of the difference in the gear ratio of the speed change before and after the calculation result of the torque difference calculation means, moves to the engaged state
Control device for a hydraulically operated transmission according to claim 1, wherein said to Rukoto.