JPH0972409A - Speed changing controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a shock caused by tying up by limiting or stopping a boosting value or boosting control based on the generation of tying up when hydraulic pressure in the releasing side friction engaging device of a clutch to clutch speed change is temporarily boosted after the hydraulic pressure of the engaging side friction engaging device is increased. SOLUTION: The possibility of down shifting from a third to a second speed is determined (step 12). If the determination is positive, tying up detection is performed (step 13). Then, the generation tying up is determined (step 14) and if the determination is positive, the re-boosting amount of a second brake as a friction engaging device in a releasing side is reduced according to the amount of tying up (step 15). Further, the hydraulic pressure of the second brake in the releasing side is learned and controlled (step 17). On the other hand, if the determination of the generation of tying up is negative, the generation of shock at the end of speed changing is determined (step 18) and if its generation is determined, the control amount of the re-boosting control of the second brake in the releasing side is increased (step 19).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling a shift in an automatic transmission of a vehicle, and particularly to releasing one of two predetermined friction engagement devices such as a clutch and a brake and engaging the other. So-called clutch
The present invention relates to a control device that controls a two-clutch shift.

[0002]

2. Description of the Related Art Since a clutch-to-clutch shift is a shift in which two friction engagement devices are simultaneously controlled and executed, it is varied depending on the control method of these friction engagement devices, that is, the hydraulic conditions. It is possible to execute various gear shifts. For example, in the control device disclosed in Japanese Patent Laid-Open No. 62-261747, while the friction engagement device on the engagement side is maintained in the state immediately before engagement during clutch-to-clutch shift,
By controlling the hydraulic pressure of the friction engagement device on the disengagement side, the input rotation speed is initially changed with the first rate of change, and then the input rotation speed is changed with the second rate of change. The friction engagement device on the engagement side is configured to be completely engaged when the number reaches the number of synchronous rotations of the gear after the gear shift.

The control device described in this publication performs control for smoothly changing the input rotation speed by controlling only the engaging force of the friction engagement device on the release side.
It is possible to prevent a delay in control as compared with the case where the engaging forces of the friction engagement devices on both the engagement side and the release side are controlled at the same time. Further, since the input rotation speed is changed smoothly, shift shock can be improved.

[0004]

SUMMARY OF THE INVENTION The above-described conventional apparatus maintains one of the two friction engagement devices involved in gear shifting immediately before engagement, thereby substantially controlling the gear shift transition period. The object is configured to be the other friction engagement device. However, this is effective in avoiding the simultaneous control of the hydraulic pressures of the two friction engagement devices,
There is room for improvement in more effectively controlling the two friction engagement devices involved in gear shifting.

That is, when both the engaging forces of the two friction engaging devices decrease, the engine speed increases in the power-on state, and conversely, the engaging forces of the two friction engaging devices both increase. In that case, a so-called tie-up state occurs and the output torque decreases. Also, by simultaneously controlling the hydraulic pressures of the two friction engagement devices involved in clutch-to-clutch shift, and temporarily increasing the release-side hydraulic pressure at the end of the shift, the change in output torque is moderated and shift shock is reduced. Can be improved. And the conventionally known engine torque reduction control during shifting or at the end of
When used in combination with the above temporary boost control, the effect of improving gear shift shock is further enhanced.

However, when the hydraulic pressure of the disengagement side frictional engagement device is increased at the gear shift end time, if the pressure increase value is kept constant, the change of oil with time, the change of oil used or the temperature of oil is changed. There is a possibility that the engagement pressure of the disengagement side frictional engagement device, which has been increased due to the difference in viscosity due to the low pressure, becomes higher than the planned pressure, or that the pressure increase timing cannot be well controlled. In such a case, the engagement forces of the two friction engagement devices involved in the gear shift are both increased, so-called tie-up becomes prominent, the fluctuation of the output torque may increase, and the shock may increase.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a control device capable of preventing a shock due to tie-up during clutch-to-clutch shift. .

The object of the present invention is to stop the boosting control or to raise the boosting value when tie-up is detected when re-boosting the hydraulic pressure of the disengagement side frictional engagement device during clutch-to-clutch shifting. Is achieved by lowering.

[0009]

In order to achieve the above-mentioned object, the invention described in claim 1 is the first aspect of the invention.
When the clutch-to-clutch shift is performed in which the second friction engagement device is released and the second friction engagement device is engaged, at the predetermined time after the hydraulic pressure of the second friction engagement device is increased. In a shift control device for an automatic transmission that temporarily raises the hydraulic pressure of a first friction engagement device, means for detecting tie-up associated with an increase in the hydraulic pressure of the first friction engagement device, and a tie by the means. And a means for lowering the pressure increase value of the oil pressure of the first friction engagement device or stopping the pressure increase control to decrease the oil pressure of the first friction engagement device when an up is detected. It is what

Therefore, in the invention described in claim 1,
When the tie-up is detected, the hydraulic pressure of the frictional engagement device on the disengagement side is lowered, so the tie-up is eliminated and the shift shock is prevented.

According to a second aspect of the present invention, means for executing a control for reducing the input torque to the automatic transmission during the clutch-to-clutch shift, and the hydraulic pressure of the first friction engagement device are used. And a means for increasing the reduction amount of the input torque when the input torque is reduced.

Therefore, according to the second aspect of the invention, when the output torque cannot be reduced by increasing the engagement pressures of the two friction engagement devices involved in the clutch-to-clutch shift, the automatic transmission is changed. Since the input torque is reduced, the change in the output torque is alleviated and the shift shock becomes good.

Further, according to the invention described in claim 3, in the clutch-to-clutch shift in which the first friction engagement device is disengaged and the second friction engagement device is engaged, the second friction engagement device is engaged. In a shift control device for an automatic transmission that temporarily raises the hydraulic pressure of the first friction engagement device at a predetermined time after the hydraulic pressure of the engagement device is raised, the pressure of the first friction engagement device is increased. The means for detecting the result of the gear shift performed and the result of the gear shift detected by the means for the next clutch
And a means for reflecting the hydraulic pressure increase value of the first friction engagement device at the time of clutch shifting.

Therefore, in the invention described in claim 3,
Among the friction engagement devices involved in clutch-to-clutch gear shifting, the re-pressurization value of the hydraulic pressure of the friction engagement device on the disengagement side is updated to reflect the status of the gear shifting. The shift shock is improved by absorbing variations in the difference.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be specifically described with reference to the drawings. FIG. 1 is an overall control system diagram showing an embodiment of the present invention. An engine E, to which an automatic transmission A is connected, is configured to electrically control its output, An electronic throttle valve 13 driven by a motor 16 is provided in the intake pipe line 12. On the other hand, the depression amount of the accelerator pedal 15 for controlling the output of the engine E, that is, the accelerator opening degree is detected by a sensor (not shown), and the detection signal is input to the engine electronic control unit (E-ECU) 17. . The electronic control unit 17 includes a central processing unit (CP)
U), a storage device (RAM, ROM), and an input / output interface. The electronic control unit 17 controls the engine (E / G) rotation speed N, intake air as data for control. Quantity Q, intake air temperature,
Various signals such as a throttle opening, a vehicle speed, an engine water temperature, and a signal from a brake switch are input. Based on these data, the electronic throttle valve 13
Is controlled, and the fuel injection amount and ignition timing of the engine E are controlled.

In the automatic transmission A, the hydraulic control device 18 controls gear shifting and lockup clutch, line pressure, or engagement pressure of a predetermined friction engagement device. The hydraulic control device 18 is configured to be electrically controlled, has first to third shift solenoid valves S1,..., S3 for performing a shift, and has a first for controlling an engine brake state. 4 solenoid valve S4, linear solenoid valve SLT for controlling line pressure, linear solenoid valve SLN for controlling accumulator back pressure, linear for controlling engagement pressure of a lock-up clutch or a predetermined friction engagement device. A solenoid valve SLU is provided.

An electronic control unit (T-ECU) 19 for an automatic transmission that outputs a signal to these solenoid valves to control gear shift, line pressure, accumulator back pressure, etc.
Is provided. This electronic control unit for automatic transmission 19
Is a central processing unit (CPU) and a storage device (RA
M, ROM) and an input / output interface. The electronic control unit 19 includes throttle opening, vehicle speed, engine coolant temperature, signals from a brake switch, shift position,
A signal from a pattern select switch, a signal from an overdrive switch, a signal from a C0 sensor that detects the rotational speed of a clutch C0 described later, an oil temperature of the automatic transmission,
A signal from a manual shift switch, a signal from a torque sensor that detects output torque, and the like are input.

The electronic control unit 19 for the automatic transmission and the electronic control unit 17 for the engine are connected to each other so that data communication is possible, and the electronic control unit 17 for the engine transfers to the electronic control unit 19 for the automatic transmission. On the other hand, a signal such as the intake air amount per rotation (Q / N) is transmitted, and an instruction signal for each solenoid valve is sent from the automatic transmission electronic control unit 19 to the engine electronic control unit 17. A signal equivalent to, a signal instructing a shift speed, and the like are transmitted.

That is, the electronic control unit 19 for the automatic transmission
Is based on input data and a map stored in advance, and indicates ON / OF of a gear position and a lock-up clutch.
F, or the pressure regulation level of the line pressure or the engagement pressure is determined, and an instruction signal is output to a predetermined solenoid valve based on the result of the determination, and further, a failure determination and control based on the failure are performed. . The engine electronic control unit 17 controls the fuel injection amount, the ignition timing, the opening degree of the electronic throttle valve 13 and the like based on the input data, and also controls the fuel injection amount at the time of shifting in the automatic transmission A. The output torque is temporarily reduced by reducing the ignition timing, changing the ignition timing, or reducing the opening of the electronic throttle valve 13.

FIG. 2 is a diagram showing an example of a gear train of the above-mentioned automatic transmission A, and in the configuration shown here, it is configured to set five forward gears and one reverse gear. That is, the automatic transmission A shown here is
, A sub transmission unit 21 and a main transmission unit 22. The torque converter 20 includes a lock-up clutch 23
The lock-up clutch 23 has a front cover 25 integrated with the pump impeller 24.
(Hub) 2 integrally mounted with the turbine runner 26
7 is provided. An engine crankshaft (each not shown) is connected to a front cover 25 and an input shaft 28 to which a turbine runner 26 is connected.
Is connected to the carrier 30 of the overdrive planetary gear mechanism 29 that constitutes the subtransmission portion 21.

The carrier 3 in this planetary gear mechanism 29
A multi-plate clutch C0 and a one-way clutch F0 are provided between the first gear 0 and the sun gear 31. The one-way clutch F0 is engaged when the sun gear 31 rotates forward relative to the carrier 30 (rotation in the rotation direction of the input shaft 28). A multi-disc brake B0 for selectively stopping the rotation of the sun gear 31 is provided.
The ring gear 3 which is an output element of the subtransmission portion 21
2 is connected to an intermediate shaft 33 which is an input element of the main transmission unit 22. Further, an NC0 sensor 34 for detecting the rotation speed of the multi-plate clutch C0 is provided.

Therefore, in the sub-transmission portion 21, the entire planetary gear mechanism 29 rotates integrally with the multi-plate clutch C0 or the one-way clutch F0 in the engaged state, so that the intermediate shaft 33 has the same speed as the input shaft 28. At low speed. When the brake B0 is engaged and the rotation of the sun gear 31 is stopped, the speed of the ring gear 32 is increased with respect to the input shaft 28 and the ring gear 32 is rotated forward, so that a high gear is established.

On the other hand, the main transmission section 22 includes three sets of planetary gear mechanisms 40, 50, and 60, and their rotating elements are connected as follows. That is, the sun gear 41 of the first planetary gear mechanism 40 and the sun gear 51 of the second planetary gear mechanism 50 are integrally connected to each other, and the ring gear 43 of the first planetary gear mechanism 40 and the carrier 52 of the second planetary gear mechanism 50 are connected to each other. The three members of the third planetary gear mechanism 60 and the carrier 62 are connected, and the output shaft 65 is connected to the carrier 62. Further, the ring gear 53 of the second planetary gear mechanism 50 is connected to the sun gear 61 of the third planetary gear mechanism 60. A torque sensor 67 for detecting the output torque is attached to the output shaft 65.

In the gear train of the main transmission unit 22, it is possible to set a reverse gear and four gears on the forward side, and clutches and brakes therefor are provided as follows. First, the clutch will be described. The ring gear 53 of the second planetary gear mechanism 50 and the third gear
A first clutch C1 is provided between the sun gear 61 of the planetary gear mechanism 60 and the intermediate shaft 33, and the sun gear 41 of the first planetary gear mechanism 40 and the sun gear 51 of the second planetary gear mechanism 50 and the intermediate shaft are connected to each other. A second clutch C2 is provided between the clutch 33 and the second clutch C2.

Next, the brake will be described. The first brake B1 is a band brake, and the sun gears 41 and 5 of the first planetary gear mechanism 40 and the second planetary gear mechanism 50.
It is arranged to stop the rotation of 1. A first one-way clutch F1 and a second brake B2, which is a multi-plate brake, are arranged in series between the sun gears 41 and 51 (that is, the common sun gear shaft) and the casing 66. One-way clutch F1 has sun gears 41 and 5
1 is engaged when it is about to rotate in the reverse direction (rotation in the direction opposite to the rotation direction of the input shaft 28). The third brake B3, which is a multi-plate brake, is connected to the first planetary gear mechanism 4
0 and the casing 66. As a brake for stopping the rotation of the ring gear 63 of the third planetary gear mechanism 60, a fourth brake B4, which is a multi-plate brake, and a second one-way clutch F2 are provided.
6 are arranged in parallel. The second one-way clutch F2 is adapted to be engaged when the ring gear 63 is about to rotate in the reverse direction.

In the above-described automatic transmission A, it is possible to set five forward speeds and one reverse speed by engaging and disengaging each clutch and brake as shown in the operation table of FIG. In FIG. 3, a circle indicates an engaged state, a circle indicates an engaged state during engine braking, a triangle indicates either engaged or disengaged, and blanks indicate a disengaged state.

As shown in the operation table of FIG. 3, the second
The shift between the third speed and the third speed is performed by a clutch that changes both the engaged and released states of the second brake B2 and the third brake B3.
Two-to-clutch speed change. In order to smoothly perform this gear shift, the hydraulic circuit shown in FIG. 4 is incorporated in the hydraulic control device 18 described above.

In FIG. 4, reference numeral 70 indicates a 1-2 shift valve, reference numeral 71 indicates a 2-3 shift valve, and reference numeral 72 indicates a 3-4 shift valve. The communication state of each port of these shift valves 70, 71, 72 at each shift speed is determined by the respective shift valves 70, 71, 7
2 as shown below. The numbers indicate the respective gears. A third brake B3 is connected via an oil passage 75 to a brake port 74 that communicates with the input port 73 at the first speed and the second speed among the ports of the 2-3 shift valve 71. An orifice 76 is interposed in this oil passage, and the orifice 76 and the third brake B3
A damper valve 77 is connected between and. The damper valve 77 sucks a small amount of hydraulic pressure to perform a buffering action when the line pressure is suddenly supplied to the third brake B3.

Reference numeral 78 is a B-3 control valve, and the engagement pressure of the third brake B3 is directly controlled by this B-3 control valve 78. That is, the B-3 control valve 78 includes a spool 79, a plunger 80, and a spring 81 interposed therebetween, and an oil passage 75 is connected to an input port 82 opened and closed by the spool 79. Output port 8 that is selectively communicated with input port 82
3 is connected to the third brake B3. Further, the output port 83 is connected to a feedback port 84 formed on the distal end side of the spool 79. On the other hand, among the ports 85 of the 2-3 shift valve 71, a port 86 that outputs the D range pressure at the third or higher speed is provided through a hydraulic passage 87 to the port 85 that opens at the place where the spring 81 is disposed. Are in communication. A lockup clutch linear solenoid valve SLU is connected to a control port 88 formed on the end side of the plunger 80.

Therefore, the B-3 control valve 78
Is configured such that the pressure regulation level is set by the elastic force of the spring 81 and the hydraulic pressure supplied to the port 85, and the elastic force of the spring 81 increases as the signal pressure supplied to the control port 88 increases. There is.

Further, reference numeral 89 in FIG. 4 denotes a 2-3 timing valve. The 2-3 timing valve 89 has a spool 9 having a small diameter land and two large diameter lands.
0 and a first plunger 91, and a first plunger 9 with a spring 92 and a spool 90 interposed therebetween.
1 and a second plunger 93 arranged on the opposite side. An oil passage 95 is connected to a port 94 at an intermediate portion of the 2-3 timing valve 89, and the oil passage 95
Of the ports of the 2-3 shift valve 71, it is connected to a port 96 which is communicated with the brake port 74 at the third or higher speed.

Further, the oil passage 95 is branched on the way to open a port 97 between the small diameter land and the large diameter land.
Is connected via an orifice. The port 98, which is selectively communicated with the port 94 at the intermediate portion, is the oil passage 9
9 is connected to the solenoid relay valve 100. The lock-up clutch linear solenoid valve SLU is connected to the port opened at the end of the first plunger 91, and the second brake B2 is passed through the orifice at the port opened at the end of the second plunger 93. Connected.

The oil passage 87 is for supplying and discharging hydraulic pressure to and from the second brake B2, and a small diameter orifice 101 and an orifice 102 with a check ball are interposed in the middle thereof. Further, the oil passage 103 branched from the oil passage 87 has a large diameter orifice 10 provided with a check ball that opens when the pressure is exhausted from the second brake B2.
4 is interposed, and this oil passage 103 is connected to an orifice control valve 105 described below.

The orifice control valve 105 is a valve for controlling the exhaust pressure speed from the second brake B2, and the port 107 formed in the intermediate portion so as to be opened and closed by the spool 106 has the second brake B2.
The oil passage 103 is connected to a port 108 formed below the port 107 in the figure. A port 109 formed above the port 107 to which the second brake B2 is connected in the drawing is a port that is selectively communicated with the drain port, and the port 109 is connected to the port 109 via an oil passage 110. The port 111 of the B-3 control valve 78 is connected. The port 111 is a port that is selectively communicated with the output port 83 to which the third brake B3 is connected.

Of the ports of the orifice control valve 105, a control port 112 formed at the end opposite to the spring for pressing the spool 106 is connected to the port 114 of the 3-4 shift valve 72 via the oil passage 113. ing. This port 114 outputs the signal pressure of the third solenoid valve S3 at the shift speed of the third speed or lower, and the fourth speed.
It is a port for outputting the signal pressure of the fourth solenoid valve S4 at a shift speed higher than the high speed. Further, an oil passage 115 branched from the oil passage 95 is connected to the orifice control valve 105, and the oil passage 115 is selectively connected to the drain port.

Incidentally, the port 11 for outputting the D range pressure at the second or lower speed in the 2-3 shift valve 71.
6 through the oil passage 11 at the port 117 opening at the position where the spring 92 is arranged in the 2-3 timing valve 89.
8 are connected. Also 3-4 shift valve 72
Of these, a port 119, which is communicated with the oil passage 87 at a speed lower than the third speed, is connected to the solenoid relay valve 100 via an oil passage 120.

In FIG. 4, reference numeral 121 denotes an accumulator for the second brake B2, and the back pressure chamber thereof is supplied with the accumulator control pressure adjusted according to the hydraulic pressure output by the linear solenoid valve SLN. There is. The accumulator control pressure is configured to increase as the output pressure of the linear solenoid valve SLN decreases. Therefore, the second brake B
The transitional hydraulic pressure for engagement / disengagement 2 is such that the lower the signal pressure of the linear solenoid valve SLN, the higher the transition pressure.

Reference numeral 122 represents a C-0 exhaust valve, and reference numeral 123 represents an accumulator for the clutch C0. C-0 exhaust valve 1
Numeral 22 operates to engage the clutch C0 to apply the engine brake only in the second speed in the second speed range.

Therefore, according to the hydraulic circuit described above,
If the port 111 of the B-3 control valve 78 communicates with the drain, the engagement pressure of the third brake B3 can be directly regulated by the B-3 control valve 78, and the regulation level can be adjusted by the linear solenoid valve. SLU
Can be changed by If the spool 106 of the orifice control valve 105 is in the position shown in the left half of the figure, the second brake B2 can be communicated with the oil passage 103 through this orifice control valve 105, so that the large diameter orifice 104 is used. Exhaust pressure is possible and therefore the drain speed from the second brake B2 can be controlled.

In the above-described automatic transmission, the second brake B2 is released and the third brake B3 is engaged at the second speed, and the second brake B2 is engaged and the third brake B3 is engaged at the third speed. Since the gears are engaged, the shift between the second speed and the third speed is a clutch-to-clutch shift in which the two brakes B2 and B3 are operated together. Therefore, in the shift control device according to the present invention, the engagement pressure of the second brake B2 and the third brake B3 involved in the shift at the time of power-on downshift from the third speed to the second speed will be described below. To control.

FIG. 5 schematically shows the control routine, and it is judged whether or not the downshift from the third speed to the second speed is output as the control start condition (step 1), and the shift is output. If not, the routine exits without any particular control. On the contrary, from the third speed to the second
If the shift to the high speed is output, that is, if the result of the determination in step 1 is "yes", the process proceeds to step 2 and it is determined whether or not the control end condition is satisfied.

This control termination condition is the input rotation speed (turbine rotation speed or rotation speed of a member integrated with the turbine) NC0.
A predetermined time elapses from when the rotational speed reaches a rotational speed obtained by subtracting a predetermined rotational speed (for example, 50 rpm) from the synchronous rotational speed of the second speed (output rotational speed multiplied by a gear ratio of the second speed). , Or that a gear shift to a gear other than the second gear is output, and either condition is satisfied,
The control end condition is satisfied.

When the shift from the third speed to the second speed is output, the 2-3 shift valve 71 is switched and
The input port 73 communicates with the brake port 74.
Therefore, through the oil passage 75 and the orifice 76, the third
Hydraulic pressure is supplied to the brake B3, and its engagement pressure is B-3.
The pressure is adjusted by the control valve 78.

On the other hand, since the oil passage 87 communicating with the second brake B2 is communicated with the drain through the port 86, the pressure is discharged from the second brake B2. The transient hydraulic pressure of the second brake B2 is changed by the accumulator control valve 105. That is, the third brake B3 is engaged while adjusting its engaging pressure, and the second brake B2 is released while adjusting its engaging pressure.

If the result of the determination in step 2 is "no",
That is, when the control end condition is not satisfied, it is determined whether the sweep control start condition is satisfied (step 3).
This sweep control is a control for temporarily gradually increasing (increasing) the hydraulic pressure of the second brake B2, which is the disengagement side frictional engagement device at the time of downshifting to the second speed, and specifically, the duty of the linear solenoid valve SLN. This is done by gradually changing the ratio. Also, this sweep control is executed immediately before the end of the shift, and therefore the control start condition is
The vehicle speed is equal to or lower than a predetermined vehicle speed, and the input rotation speed NC0 exceeds the rotation speed lower than the synchronous rotation speed of the second speed by a predetermined reference value, or the current input rotation speed NC0 and the synchronous rotation speed. That is, the ratio of the difference between the number of rotations and the increase rate of the input rotation speed is below a predetermined reference value. It should be noted that these reference values are values that are set in advance as a map according to parameters indicating the traveling state such as vehicle speed and throttle opening.

If the above sweep control start condition is not satisfied, that is, if the result of the determination in step 3 is "no", the basic hydraulic pressure control is executed (step 4). The control target of the basic hydraulic control is directly the signal pressure of the linear solenoid valve SLN, and thus the engagement pressure of the second brake B2 is ultimately controlled, as in the above-mentioned sweep control. This basic hydraulic pressure control is executed unless the above-mentioned sweep control start condition is satisfied. Therefore, the basic hydraulic pressure control is immediately executed by the output of the shift from the third speed to the second speed, and the output of the linear solenoid valve SLN. The signal pressure is increased, and the back pressure of the accumulator 121 for the second brake B2 is reduced to a predetermined constant pressure.

Therefore, immediately after the speed change from the third speed to the second speed is output, the engagement pressure is reduced by exhausting the pressure from the second brake B2, and the oil accumulated in the accumulator 121 causes a predetermined low pressure. Maintained at. The engagement pressure of the third brake B3 is maintained at a low pressure by lowering the signal pressure sent from the linear solenoid valve SLN to the B-3 control valve 78 to lower the pressure regulation level of the B-3 control valve 78. It Therefore, since the engagement pressures of these two brakes B2 and B3 are both low, the input rotational speed NC0 rapidly increases, and the shift proceeds.
In this way, the engine torque reduction control is executed at the end timing of the inertia phase when the rotation speed of the rotating member changes. The control method for reducing the engine torque is as described above, such as delaying the ignition timing.

When the gear shift progresses and the input rotational speed NC0 increases, the engagement pressure of the third brake B3 is increased,
The engagement pressure is almost sufficient to achieve the second speed. Specifically, this is executed by increasing the output pressure of the linear solenoid valve SLN and increasing the pressure regulation level of the B-3 control valve 78.

Around this, the sweep control is executed when the above-described sweep control start condition is satisfied (step 5). That is, the output pressure of the linear solenoid valve SLN is gradually reduced, and the back pressure of the accumulator 121 for the second brake B2 is gradually increased. At this point, since the third solenoid valve S3 is outputting the signal pressure, the hydraulic pressure is being supplied to the control port 112 of the orifice control valve 105, so that the port 107 communicating with the second brake B2 is It is closed and the pressure is exhausted from the second brake B2 through the small orifices 101 and 102.

Therefore, when the back pressure of the accumulator 121 increases and the amount of oil pushed out from the accumulator 121 increases, the orifice 10
When the amount of oil pushed out from the accumulator 121 becomes larger than the amount of oil drained through 1, 102, the engagement pressure of the second brake B2 starts to increase. In the present invention, the engagement pressure of the second brake B2 is gradually increased (sweep up) almost simultaneously with or immediately after the engagement pressure of the third brake B3 is increased as described above.

By thus increasing the engagement pressure of the second brake B2, the two brakes B2 and B3 both have a torque capacity, and a so-called tie-up state occurs. As a result, the action of reducing the output shaft torque occurs. That is, the third brake B for setting the second speed
Since 3 is almost completely engaged, the output shaft torque tends to rapidly increase to the torque according to the gear ratio in the second speed, but the torque transmitted to the output shaft by the second brake B2 is Since it is responsible for a part, rising of the output shaft torque is suppressed.

At a point in the middle of the above-mentioned sweep control, more specifically, a predetermined time after the engagement pressure of the second brake B2 is increased and the input rotation speed NC0 reaches a predetermined rotation speed, The third solenoid valve S3 outputs a signal pressure to switch the orifice control valve 105.
That is, the port 107 communicates with the port 108, and the second brake B2 is provided with the oil passage 10 having the large diameter orifice 104.
It is connected to 3. Therefore, the accumulator 12
The back pressure of 1 is gradually increased while the second brake B is increased.
Since the orifice of the drain path from 2 is enlarged,
The hydraulic pressure of the second brake B2 is maintained at a slightly increased value, and the tie-up state described above is maintained. The output signal pressure of the linear solenoid valve SLN is maintained at that pressure after being increased to a predetermined pressure.

Thus, after the output shaft torque slowly increases and the input speed NC0 approaches the second speed synchronous speed,
When a predetermined time has elapsed, the above-described control end condition is satisfied, and the result of the determination in step 2 is "yes", whereby the control is ended (step 6). Specifically, the linear solenoid valve SLN is controlled based on a control routine other than the control described above.

Note that the engine torque reduction control is performed by the return control when the input rotational speed NC0 increases to the predetermined rotational speed and then a predetermined time elapses.
The torque reduction amount is controlled to be zero within a predetermined time.

The above control will be described with reference to the time chart shown in FIG. 6. The shift output is performed at time t1 when a predetermined time has elapsed from time t0 when the determination of shift from the third speed to the second speed is established. As a result, the 2-3 shift valve 71 is switched, so that the engagement pressure of the second brake B2 is reduced and the engagement pressure of the second brake B2 is reduced.
The hydraulic pressure is supplied to and the engagement pressure is increased to the pressure in the low pressure standby state. Second and third brakes B2, B
As the engaging pressures of 3 are both controlled to be low, the input rotation speed NC0 starts to increase gradually, and the output shaft torque To also gradually increases.

On the other hand, the linear solenoid valve SLN is controlled by the above-mentioned basic hydraulic pressure control in order to set the engagement pressure of the second brake B2 to a predetermined low pressure. That is, the control value is maintained at the predetermined level.

The sweep control of the linear solenoid valve SLN is started at time t2 when the input rotational speed NC0 increases and the above-mentioned sweep control start condition is satisfied, and the control amount (duty ratio) is changed stepwise.

When the input speed NC0 increases and approaches the second speed synchronous speed, the torque down control of the engine is executed (time t3). Immediately after that, at time t4, the engagement pressure of the third brake B3 is increased to a level where it is almost completely engaged, and the output shaft torque To starts to increase accordingly, but with the sweep control of the linear solenoid valve SLN. As a result, the engagement pressure of the second brake B2 is increased (at time t5) and maintained at a predetermined engagement pressure, so that the gradient of increase in the output shaft torque To becomes gentle.

At time t6 in the process, the engine torque return control is started, and the output of the signal pressure of the third solenoid valve S3 is stopped. Then, t when the control end condition is satisfied
At 7th point, the sweep control of the linear solenoid valve SLN is terminated, and the second brake B2 is rapidly released.

Explaining the relationship between the respective hydraulic pressures in this process, B3 which is the engagement pressure of the third brake B3 at time t0.
The pressure is much lower than the B2 pressure which is the hydraulic pressure of the second brake B2, and after the time t1, the B3 pressure is gradually increased and the B2 pressure is gradually decreased. And at time t2, B
2 Pressure is maintained slightly higher than B3 pressure. At time t6, the B2 pressure is set to be slightly higher than the pressure at time t2 and lower than the pressure at time t0.
The 3 pressure is set higher than the B2 pressure at time t0.

Therefore, according to the above-mentioned control device, since the second and third brakes B2 and B3 are maintained at a low hydraulic pressure after the gear shift output and the gear shift is rapidly advanced, a delay in gear shift or a rattling sensation caused by it is caused. It can be prevented. After the shift progresses to increase the engagement pressure of the third brake B3 on the engaging side, the hydraulic pressure of the second brake B2 on the releasing side is increased for a predetermined period, so that the increase in the output shaft torque is alleviated. As a result, shift shock is reduced. Further, since the engine torque reduction control is also performed, the increasing tendency of the output shaft torque is further alleviated and the shift shock becomes better.

The speed of engagement / disengagement of the frictional engagement devices such as the brakes B2 and B3 is affected by the speed of oil supply / discharge, and the flow speed of oil is affected by its viscosity. Therefore, the speed (timing) of engagement / disengagement of the frictional engagement device differs depending on whether the viscosity of the oil is high or low. Therefore, for the control value obtained from the map when performing the above-described control, it is possible to prepare a high temperature map and a low temperature map, and select and use one of these maps based on the temperature conditions. preferable. In that case, as shown in FIG. 7, a map for low temperature is used until the engine water temperature or the oil temperature rises above a predetermined reference temperature α ° C., and the engine water temperature or the oil temperature is used as the reference. It is preferable to use the high temperature map until the temperature falls below another reference temperature β ° C. lower than the temperature α ° C. If there is a difference (hysteresis) between the reference temperatures for switching the maps, hunting can be prevented.

As described above, when the clutch-to-clutch shift is performed, the output torque change gradient can be made gentle by increasing the hydraulic pressure of the disengagement side frictional engagement device at the end of the shift. When the value is large, the two friction engagement devices involved in the gear shift both have an engagement force of a predetermined value or more, and the tie-up state becomes remarkable, and the gear shift is caused by the decrease in the output torque and the subsequent increase in the output torque. Shocks may be exacerbated. Therefore, the control device according to the present invention described above is configured to control the re-pressurization value of the disengagement side frictional engagement device as follows.

That is, in FIG. 8, after processing the input signal (step 10), it is judged whether or not each sensor is normal (step 11). If there is an abnormality in the sensor, the data for control is not accurate, so the process returns without any particular control. If each sensor is normal, downshift from 3rd speed to 2nd speed It is judged whether or not the above judgment is established (step 12).

If a negative determination is made here, the process returns without performing any particular control, and if an affirmative determination is made, on the contrary, tie-up detection is performed (step 1).
3). Tie-up during clutch-to-clutch shifting is a phenomenon in which the output torque is reduced by the fact that both the frictional engagement device on the engagement side and the frictional engagement device on the release side have an engagement force that is greater than or equal to a predetermined level. The detection can be performed by the torque sensor 67 described above, or can be performed by a predetermined rotation speed sensor. The occurrence of tie-up is judged based on the signal obtained in this way (step 14), and when tie-up is detected, the second brake, which is the frictional engagement device on the release side, is determined according to the tie-up amount. Re-pressurization value of B2, that is, the engagement side friction engagement device
Second brake B2 after increasing the hydraulic pressure of brake B3
The increase value of the pressure PB2 is reduced according to the tie-up amount (step 15).

That is, the re-boosting value of the second brake B2 at the time of downshifting from the third speed to the second speed is set in advance to a predetermined value (nominal value) by design, and the boosting value is the actual value. If it is too high during gear shifting, tie-up will occur and this will be reduced. FIG. 9 shows an example of a map used for the control. The larger the tie-up amount is, the smaller the boosting value of the hydraulic pressure PB2 of the second brake B2 is set. As an alternative control, control may be performed in which the boosting control of the hydraulic pressure PB2 of the second brake B2, which is the disengagement side frictional engagement device, is stopped. Therefore this second
The hydraulic pressure PB2 of the brake B2 is controlled to be higher than usual when the tie-up amount is small, and is controlled to be low when the tie-up amount is large, as shown by the broken line or the one-dot chain line in FIG.

If the torque reduction amount (torque reduction amount) of the engine E can be increased, the torque reduction amount is increased (step 16). FIG. 10 shows an example of a map used for the control, in which the torque reduction amount is increased in accordance with the increase amount of the pressure increase value of the hydraulic pressure PB2 of the second brake B2. That is, the boost value of the second brake B2 on the release side becomes small, or the boost control is not performed, so that the change gradient of the output torque cannot be suppressed. Therefore, the output torque of the engine E is reduced to compensate for this. Increase the degree. In that case, an upper limit value may be set for the torque reduction amount as needed.

Further, the hydraulic pressure B2 of the second brake B2 on the releasing side
Is learned and controlled (step 17). That is, the hydraulic pressure P
B2 is changed according to the tie-up amount as described above to obtain the optimum value, which is stored as a learning value, and the next clutch
Determine the hydraulic pressure PB2 for shifting the two-clutch. A specific example is shown in FIG. 11, in which the magnitude of the throttle opening θ (grades 1 to 7), the presence / absence of engine torque down, and the oil pressure PB2 of the second brake B2 depending on whether the oil temperature is high or low.
The correction value is stored, and this value is added to or subtracted from the nominal value to obtain the next hydraulic pressure PB2. The boost value is ± 2 of the nominal value.
A guard for controlling within a predetermined limit such as limiting to 0% may be provided.

On the other hand, when the negative determination is made in step 14 because the tie-up is not detected, it is determined whether or not a shock is generated at the shift end timing (step 18). That is, if the gradient of the output torque change due to the re-boosting control of the disengagement side friction engagement device is insufficient, vibration (increase / decrease in output torque) occurs due to twisting of the power transmission system, which causes a shock. May be experienced as. Therefore, this is detected by the torque sensor 67 or the like.

If the occurrence of shock is not detected, the routine exits from this routine, and if the shock is detected, the control amount of the re-boosting control of the second brake B2 on the release side is increased (step 19). ). Here, the control amount is a boost value and / or boost time, and as an example, the boost value and / or boost time is increased according to the magnitude of the shock. FIG. 12 shows an example of a map used in the control for increasing the boost value as the vibration amount increases.

Further, as described above, when the engine torque reduction control is performed to reduce the shock during gear shifting,
The engine torque down control is executed together with the above boost control to increase the torque down amount (step 2
0). FIG. 13 shows an example of a map used for increasing the torque reduction amount as the vibration amount increases.

In the above-described embodiment, the case of downshifting from the third speed to the second speed has been described as an example.
The present invention is not limited to the above embodiment, and can be similarly applied to other clutch-to-clutch shifts. Further, in the above embodiment, the linear solenoid valve SLN is sweep-controlled in order to increase the engagement pressure of the second brake B2 on the release side. However, in the present invention, the engagement force of the friction engagement device on the release side is changed. Various means can be adopted as the means for increasing the pressure, and for example, the line pressure may be increased, and the means is not limited to those shown in the above-mentioned embodiment. The present invention can be implemented for an automatic transmission or a control device therefor having a gear train or hydraulic circuit different from the gear train or hydraulic circuit shown in FIGS.

[0073]

As described above, according to the shift control device of the present invention, the hydraulic pressure of the disengagement side friction engagement device for so-called clutch-to-clutch shifting is increased. When the pressure is temporarily boosted after the tie-up, the boost value or the boost control is suppressed or stopped based on the occurrence of the tie-up, so that the shock due to the tie-up can be effectively prevented.

Further, when the boost value or the boost control is limited, the input torque is further reduced, so that the insufficient reduction in the torque due to the boost control can be compensated by the reduction in the input torque. As a result, the clutch toe It is possible to effectively prevent a shock when shifting the clutch.

Further, since the hydraulic pressure of the disengagement side frictional engagement device is updated by learning control, re-pressurization control of the hydraulic pressure of the disengagement side frictional engagement device at the time of clutch-to-clutch shift is performed in real time. Similarly to the case, the hydraulic pressure can be appropriately controlled to effectively prevent the shift shock.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a control system of an embodiment of the present invention.

FIG. 2 is a diagram mainly showing a gear train of the automatic transmission.

FIG. 3 is a diagram showing an operation table for setting each shift speed.

FIG. 4 is a diagram showing a part of a hydraulic circuit.

FIG. 5 is a flow chart schematically showing a control routine for performing a sweep control of an engagement pressure of a release side second brake at the time of downshifting from the third speed to the second speed.

FIG. 6 is a time chart thereof.

FIG. 7 is a diagram schematically showing operating temperature regions of a high temperature map and a low temperature map.

FIG. 8 is a flowchart showing an example of a routine for controlling a reduction in the boosted value of the disengagement side frictional engagement device based on the occurrence of tie-up.

FIG. 9 is a diagram showing a reduction amount of a boosted value according to a tie-up amount.

FIG. 10 is a diagram showing an engine torque reduction amount according to a reduction amount of a boost value.

FIG. 11 is a map showing an example of a learned value of hydraulic pressure of the disengagement side frictional engagement device.

FIG. 12 is a diagram showing the amount of increase in the boost value of the disengagement side frictional engagement device according to the amount of vibration of the output shaft.

FIG. 13 is a diagram showing an increase amount of an engine torque reduction amount according to a vibration amount of an output shaft.

[Explanation of Codes] 17 Electronic Control Device for Engine 18 Hydraulic Control Device 19 Electronic Control Device for Automatic Transmission A Automatic Transmission E Engine B2 Second Brake B3 Third Brake SLN Linear Solenoid Valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masato Kaikawa 1 Toyota-cho, Toyota-shi, Aichi Toyota Automobile Co., Ltd.

Claims (3)

[Claims] 1. A hydraulic pressure of the second friction engagement device is increased during clutch-to-clutch shifting in which the first friction engagement device is released and the second friction engagement device is engaged. In a shift control device for an automatic transmission, which temporarily increases the hydraulic pressure of the first friction engagement device at a predetermined time after the start, detects tie-up associated with the increase of the hydraulic pressure of the first friction engagement device. Means and means for lowering the hydraulic pressure of the first frictional engagement device by lowering the hydraulic pressure boosted value of the first frictional engagement device or stopping the hydraulic pressure control when the tie-up is detected by the means. A shift control device for an automatic transmission, comprising: 2. A means for executing input torque reduction control for the automatic transmission during the clutch-to-clutch shift, and the input torque when the hydraulic pressure of the first friction engagement device is reduced. The shift control device for an automatic transmission according to claim 1, further comprising: a means for increasing a reduction amount of 3. The hydraulic pressure of the second friction engagement device is increased during clutch-to-clutch shifting in which the first friction engagement device is released and the second friction engagement device is engaged. In a shift control device for an automatic transmission, which temporarily raises the hydraulic pressure of the first friction engagement device at a predetermined time after the operation, the result of the shift in which the pressure of the first friction engagement device is increased is detected. Means and means for reflecting the result of the shift detected by the means to the hydraulic pressure increase value of the first friction engagement device at the time of the next clutch-to-clutch shift. Shift control device for automatic transmission.