JPH09229177A - Control device of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent shock at down-shifting to be made in synchronization with the engine speed. SOLUTION: A control device concerned is for automatic transmission to perform the clutch-to-clutch shifting and the equal speed shifting and equipped with a shift judging means to judge the clutch-to-clutch shifting (Step 11) and a revolving speed control judging means to judge execution of the control to raise the revolving speed of a drive motive (Step 12) at the time of shifting judged by the shift judging means. The arrangement further includes pressure rice control means to alter the controlling contents (Steps 15 and 18) of increasing temporarily the engaging pressure of a disengage side frictional engagement device at the ending time of shifting in accordance with existence of the incremental control of the revolving speed of the drive motive to be judged by the revolving speed control judging means.

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 an automatic transmission, and more particularly to a control device for executing control for reducing shift shock together with control of a driving force source such as an engine or a motor. is there.

[0002]

2. Description of the Related Art A shock at the time of gear shift in a vehicle equipped with an automatic transmission is caused by an inertia torque of a rotating element including an engine, and therefore, a clutch that is engaged or disengaged to perform a gear shift is generally used. By controlling the hydraulic pressure of friction engagement devices such as brakes and brakes, the inertia torque is absorbed by these friction engagement devices to reduce shift shock. On the other hand, in the power transmission system from the transmission to the drive wheels, a twist may occur due to a change in the driving force due to the shift, and a torque may be generated due to the restoration of the twist. At the end timing, the output torque of the automatic transmission is reduced to suppress the twist generated in the power transmission system.

As a control method therefor, a so-called clutch, which simultaneously changes the engagement / release states of two friction engagement devices, is used.
During a two-clutch shift, the engagement pressure of the disengagement side frictional engagement device is temporarily increased at the end of the shift, and both frictional engagement devices have a torque greater than a predetermined value. It is considered to reduce the output torque (see Japanese Patent Application No. 7-70672).

Further, in order to prevent a shock due to an abrupt increase in braking torque due to engine braking, conventionally known is control for increasing the engine speed during downshifting. This is a control called constant speed shift.When the downshift is performed, the throttle valve is electrically controlled to increase the throttle opening by more than the depression amount of the accelerator pedal. Increase to the synchronous speed at the gear. In this state, the downshift is executed, and then the throttle opening is decreased to gradually increase the braking force. An apparatus for performing this type of control is disclosed in, for example, Japanese Patent Laid-Open No.
In the invention described in this publication, the throttle opening is increased by detecting the downshift at the time of the downshift with the throttle valve closed, thereby increasing the engine speed. During a constant speed shift that synchronizes with the rotation speed of the gear after the downshift, it prevents or suppresses the rise of the line pressure due to the temporary increase of the throttle opening, and the friction engagement device suddenly moves during the downshift. It is configured to prevent shock due to having torque capacity.

[0005]

The temporary increase in the release pressure of the disengagement side frictional engagement device at the above-mentioned shift end time of the clutch-to-clutch shift is caused by the input rotation speed and the shift stage after the shift. This is executed by increasing the release pressure to a preset value when the deviation from the synchronous speed reaches a predetermined value. The boost value is set to a value that does not cause excess or deficiency in the reduction of output torque, but if constant speed shift is performed as described above, throttle opening is performed in order to increase the rotation speed of the engine (driving force source). Since the driving force source, that is, the output of the engine (input of the automatic transmission) is increased accordingly, even if the release pressure of the disengagement side frictional engagement device is increased at the end of the shift, The output torque cannot be reduced sufficiently, and as a result, the output torque becomes large and the power transmission system is twisted, which may cause a shock.

In order to prevent this, the clutch
It is possible to set the pressure increase value of the disengagement side frictional engagement device at a somewhat high value at the end timing of the clutch gear shifting, but in that case, the pressure increase value of the disengagement side frictional engagement device is achieved during a shift other than the constant speed shift. The value may become excessive, and as a result, the output torque may drop significantly at the end of gear shift and shock may occur.

The present invention has been made in view of the above circumstances, and provides a control device capable of reducing shift shock in an automatic transmission that performs constant-speed shift and clutch-to-clutch shift. The purpose is.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a gear shifting operation in which a predetermined friction engagement device is released and another friction engagement device is engaged. The engagement pressure of the disengagement side frictional engagement device is temporarily increased at the end of the gear shift after the engagement of the mating side frictional engagement device is started, and the rotational speed is selectively and temporarily increased during the gear shift. In a control device for an automatic transmission connected to a driving force source, shift determining means for determining the shift for releasing the predetermined friction engagement device and releasing the other friction engagement device,
A rotation speed control determining means for determining whether or not to execute control for increasing the rotation speed of the driving force source during the shift determined by the shift determining means; and the driving force source determined by the rotation speed control determining means. And a boost control means for changing the control content for temporarily increasing the release pressure of the disengagement side frictional engagement device at the shift end timing, depending on whether or not there is an increase control of the rotational speed of the. It is a thing.

Therefore, according to the present invention, the shift judging means judges what is called clutch-to-clutch shift, and whether or not the control for increasing the rotational speed of the driving force source is carried out at the time of shifting based on the judgment, that is, the driving force. The presence or absence of control for increasing the rotation speed of the source is judged by the rotation speed control judging means. Further, during the clutch-to-clutch shift determined by the shift determining means, the release pressure of the disengagement side frictional engagement device is temporarily increased at the end of the shift. The boosting duration is changed according to the presence / absence of the increase control of the rotation speed of the driving force source determined by the rotation speed control determination means. Therefore, the release pressure increase control of the disengagement side frictional engagement device at the end of the shift becomes suitable for the input torque to the automatic transmission, and as a result, the output torque is reduced without excess or deficiency, and the shift shock is improved. Become.

[0010]

Next, the present invention will be described more specifically with reference to the drawings. First, an engine (driving force source) E and an automatic transmission A which are the objects of the present invention will be described. FIG. 6 is an overall control system diagram of the engine E to which the automatic transmission A is connected. The output is electrically controlled, and an electronic throttle valve 13 driven by a servomotor 16 is provided in the intake pipe 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, is detected by a sensor (not shown), and the detection signal is sent to an engine electronic control unit (E-ECU) 1.
7 has been entered. The electronic control unit 17 includes a central processing unit (CPU) and a storage device (RAM, RO
M) and an input / output interface. The electronic control unit 17 includes, as control data, engine (E / G) rotation speed Ne, intake air amount Q, intake air temperature, throttle air Various signals such as an opening, a vehicle speed, an engine water temperature, and a signal from a brake switch are input. The opening of the electronic throttle valve 13 is controlled based on these data, and the engine E
The fuel injection amount and the ignition timing are controlled.

In the automatic transmission A, the hydraulic control device 18 controls the shift and the lockup clutch, the line pressure, or the 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 sports mode switch, a signal output from a constant speed shift switch, etc. are input (for example, Japanese Patent Laid-Open No. 6-
309527, Japanese Patent Application No. 7-215892).

Here, the sports mode switch is a switch for selecting a mode for executing a gear shift by a manual operation or a switch for outputting a gear shift signal by a manual operation, and is arranged on a shift device, an instrument panel or the like not shown. . Further, the constant speed shift switch is a switch for downshifting one step by manual operation, and is attached to an appropriate position such as a central portion of the steering wheel. When the downshift is performed by operating these switches, the electronic throttle valve 13 is opened more than the depression amount of the accelerator pedal 15 based on the output signal from the engine electronic control unit 17, and the engine speed Ne is downshifted. A so-called constant speed shift control for increasing the synchronous speed to a later gear is executed.

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 / Ne) 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. 7 is a diagram showing an example of a gear train of the above-described 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 the 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, that is, the input rotation speed, is provided.

Therefore, in the auxiliary transmission portion 21, the entire planetary gear mechanism 29 rotates integrally when the multi-plate clutch C0 or the one-way clutch F0 is engaged, 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 has three sets of planetary gear mechanisms 40, 50, 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.

In the gear train of the main transmission section 22, a reverse gear and four forward gears can be set, and a clutch and a brake for this 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. 8, the mark 係 合 indicates the engaged state, the mark 時 に indicates the engaged state during engine braking, the mark △ indicates either engaged or released, and the blank indicates the released state.

As shown in the operation table of FIG. 8, 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 shift, a hydraulic circuit shown in FIG. 9 is incorporated in the above-described hydraulic control device 18.

In FIG. 9, 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.

Further, 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. 9 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 in the middle 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 / discharging hydraulic pressure to / 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, in the 2-3 shift valve 71, the port 11 for outputting the D range pressure at the shift speed of the second speed or lower.
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. 9, reference numeral 121 denotes an accumulator for the second brake B2, to the back pressure chamber of which the accumulator control pressure adjusted according to the hydraulic pressure output by the linear solenoid valve SLN is supplied. 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 indicates a C-0 exhaust valve, and reference numeral 123 indicates 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 automatic transmission described above, 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. 10 schematically shows a control routine at the time of shifting in the normal power-on state, and it is judged whether or not the downshift from the third speed to the second speed is output as the control start condition. However, if the shift is not output (step 1), this routine is exited without performing any control. On the contrary, if the shift from the third speed to the second speed is output, that is, if the result of the determination in step 1 is "yes", the process proceeds to step 2 to determine whether the control end condition is satisfied. Is judged.

This control termination condition is the input rotational speed (turbine rotational speed or rotational 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 operated to change over,
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, the oil passage 87, which communicates with the second brake B2, is communicated with the drain through the port 86, so 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 engagement pressure, and the second brake B2 is released while adjusting its release 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 control is executed unless the above-mentioned sweep control start condition is satisfied. Therefore, the basic hydraulic control is executed immediately by the output of the shift from the third speed to the second speed, and the output of the linear solenoid valve SLN is output. 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 shift from the third speed to the second speed is output, the pressure is exhausted from the second brake B2 to reduce its engagement pressure, 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.

Before or after this, the sweep control start condition is satisfied, whereby the sweep control is executed (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 release pressure of the second brake B2 starts to increase. In the present invention, the release pressure of the second brake B2 is gradually increased almost at the same time as or immediately after the engagement pressure of the third brake B3 is increased as described above.

By thus increasing the release 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 performing the above-mentioned sweep control, more specifically, a predetermined time after the release pressure of the second brake B2 is increased and the input rotation speed NC0 reaches a predetermined rotation speed, 3 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 input shaft speed NC0 approaches the synchronous speed of the second speed while the output shaft torque slowly increases,
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.

In the engine torque reduction control, the return control is performed when a predetermined time has elapsed after the input speed NC0 has increased to the predetermined speed.
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. 11. When a predetermined time elapses from the time point t0 when the determination of the shift from the third speed to the second speed is established, t1
Shift output is performed at the time point. Along with that, the 2-3 shift valve 71 is switched, so that the engagement pressure is reduced by exhausting the pressure from the second brake B2, and also the third brake B2.
The hydraulic pressure is supplied to 3 and the engagement pressure is increased to the pressure in the low pressure standby state. Second and third brakes B2,
As the engagement pressure of B3 is controlled to be low, the input rotational speed NC0 starts to gradually increase, 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 (at 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-described control device, after the shift output, the second and third brakes B2 and B3 are maintained at a low hydraulic pressure to allow the shift to proceed rapidly. 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. 12, a map for low temperature is used until the engine water temperature and the oil temperature rise above a predetermined reference temperature α ° C., and the engine water temperature and the oil temperature are 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) in the reference temperature for switching maps in this way,
Hunting can be prevented.

The above-described example of the shift control is an example of downshifting from the third speed to the second speed in the power-on state in which the accelerator pedal 15 is depressed, but the downshift from the third speed to the second speed is performed. The shift also occurs when the vehicle speed decreases in the power-off state in which the electronic throttle valve 13 is closed, or when the sport mode switch or the constant speed shift switch is manually operated.

An example will be described below. FIG. 1 is a flowchart for explaining the downshift from the third speed to the second speed by dividing it into three modes, and processing of an input signal including reading of data, determination of failure of sensors and switches ( After performing step 10), the so-called clutch-to-clutch shift is determined to be a downshift from the third speed to the second speed (step 11). This step 11 corresponds to the shift determining means of the present invention. If a negative determination is made here, the routine returns without performing any control, and if an affirmative determination is made, it is determined whether or not the mode is the sports mode. (Step 12).

As described above, the sport mode is a gear shift mode in which gear shifting is executed based on switch operation. As the form of the switch, the shift device is provided with each gear position, and each gear is turned on by a shift lever. Equipped with a switch that can be used, or that sets the sports mode state, and in that state the upshift switch or downshift switch is turned on by the shift lever, and also the up / down switch on the steering wheel, instrument panel, etc. Some are provided. Therefore, the judgment in step 12 is
It may be performed by determining whether or not signals are output from these switches.

When a negative determination is made in step 12 because the downshift is accompanied by a change in the running state, it is determined whether or not the power is on (step 13). That is, it is determined whether or not the electronic throttle valve 13 is open and the vehicle is driven by the output of the engine E. This can be determined based on the throttle opening.

When the affirmative determination is made in step 14 due to the power-on state, the shift is executed by the release control of the second brake B2 and the engagement control of the third brake B3 as described above (step 14). ). At the end of the inertia phase, pressure increasing control is executed to increase the release pressure of the second brake B2, which is the friction engagement device on the release side, for a predetermined period (step 15). This boosted value ΔPB2 is increased according to the rate of change (Ne dot) of the engine speed Ne, and its general tendency is shown by the broken line in FIG.
The boosting timing is as shown by the broken line in FIG. 3, and is executed for a predetermined time from immediately before the engine speed Ne reaches the synchronous speed of the second speed. Note that, in FIG. 11 described above, the change in the B2 pressure when the boosting control is performed according to the broken lines in FIGS. 2 and 3 is shown by a solid line. Further, since the power is on, the engine tokule reduction control such as the ignition retard control is simultaneously executed.

Therefore, according to the above-described control, the hydraulic pressure of the second brake B2 is increased at the end of the shift to reduce the output torque of the automatic transmission, so that the torsion torque is accumulated in the power transmission system and Along with this, a shock is effectively prevented.

On the other hand, if the answer of Step 13 is NO because the power is off, the second brake B2 is released and the third brake B3 is engaged to shift to the second speed. (Step 16). In this case, since the driving force from the engine E is not input to the automatic transmission A in the power-off state, the step-up control of the second brake B2 on the release side as in step 15 is not executed.

If an affirmative decision is made in step 12 due to the downshift in the sports mode,
A constant speed shift is executed (step 17). Therefore, step 12 corresponds to the rotation speed control determination means of the present invention.

In this constant speed shift, the engine speed Ne is increased to the synchronous speed at the gear after the downshift,
This is a shift control for executing a downshift in that state, and the electronic throttle valve 13 is connected to the electronic control unit 17 for the engine.
It is executed by temporarily opening by.

Further, the pressure increase control of the disengagement side frictional engagement device is executed at the timing of ending the shift (step 18). This is a control corresponding to the increase of the throttle opening θ for increasing the engine speed Ne to the synchronous speed, and the increase amount of the throttle opening θ is not particularly large.
The boost value ΔPB2 of the brake B2 is set to a smaller value than in the case of normal power-on downshift, and the boost time is shortened. This is shown by the solid lines in FIGS. The change in the B2 pressure when this control is performed is shown by the alternate long and short dash line in FIG.

Therefore, the hydraulic pressure P of the second brake B2 on the disengagement side is corresponding to the increase of the throttle opening degree accompanying the constant speed shift.
Since B2 is temporarily boosted, it is possible to perform reduction control without excess or deficiency of output torque, and as a result, it is effective that torsion torque is accumulated in the power transmission system and shock is generated accordingly. To be prevented. Therefore, step 18 and step 15 correspond to the boost control means of the present invention.

The constant speed shift is not limited to the downshift in the sports mode described above, but can be executed by turning on the constant speed shift switch described above. Therefore, step 12 in FIG. It may be replaced with a step (step 12 ') for determining whether or not the switch is a dow shift by operating a switch.

By the way, during the clutch-to-clutch shift described above, a decrease in the engine speed due to tie-up of the friction engagement device, an overshoot of the engine speed due to underlap, etc. are detected, and based on the detection result. By executing the learning control for changing the hydraulic pressure, it is possible to reduce shift shocks due to individual differences and changes in the automatic transmission over time. Such hydraulic pressure learning control is
This is also effective for controlling the release pressure of the release side frictional engagement device, which may be executed as step 19 or step 20 shown by the broken line in FIG.

In this case, since the magnitude and change of the input torque to the automatic transmission A may be different between the power-on state and the state in which the throttle opening is increased for the constant speed shift, the power may be different. It is preferable to perform learning control separately in the ON state and the constant speed shift state. For example, as shown in FIG. 4, the step-up value ΔPB2 of the second brake pressure PB2 at the time of a normal gear shift is determined by the presence or absence of the engine torque down control shown in (A) and each stage of the throttle opening θ (from 0% to 100%). The learning value is divided into eight stages), and the pressure increase value ΔPB2 of the second brake pressure PB2 at the time of shifting in the sports mode is determined by the presence or absence of the engine torque down control and the engine speed Ne shown in (B).
Change rate (Ne dot) of each state (small, medium, large, maximum)
Also, the learning is performed separately for each stage of the throttle opening θ.

Further, since the amount of decrease in the output torque becomes large in accordance with the duration of the pressure increase of the release pressure of the second brake B2,
The boosting duration ΔT may be learned and controlled. Also in that case, as shown in FIG. 5, it is divided into a normal power-on downshift and a downshift in the sports mode, and in the normal power-on state, the presence or absence of the engine torque down control shown in (A) and the throttle opening θ are shown. Each stage (0% to 10
0% is divided into 8 stages and learning is performed separately, and the boosting time ΔT at the time of shifting in the sports mode is (B)
Whether or not the engine torque reduction control is performed and the rate of change (Ne dot) of the engine speed Ne (small, medium,
(Large, maximum) and throttle opening θ are learned in each step.

In the examples shown in FIGS. 4 and 5, the presence / absence of torque reduction may be changed so as to be classified according to the torque reduction amount or the duration thereof. Further, the learning control at the time of shifting in the sports mode and the learning control at the time of shifting by operating the constant speed shift switch may be performed separately or the same learning control may be performed.

That is, the boost control means in the present invention can be configured to include means for learning control of boost control contents such as boost value and boost duration, and the learning control means is a driving force source. Learning may be performed separately for each control state.

In the above 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-described embodiment, and can be similarly applied to other gear shifts. 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. 7 and 9. Further, as the driving force source, another power output device such as an electric motor can be used instead of the engine.

[0077]

As described above, according to the present invention,
In the so-called clutch-to-clutch shift downshift, the release pressure increase control of the disengagement side frictional engagement device that is normally executed at the end of the shift is performed to increase the rotational speed of the driving force source with the downshift. Since it is changed according to the presence or absence of control, it is possible to smoothly change the input rotation speed, that is, the rotation speed of the driving force source, toward the synchronous rotation speed of the gear after the shift, and the output torque is reduced without excess or deficiency. As a result, the torsion generated in the power transmission system or the torsion torque accumulated can be reduced, and the shock caused thereby can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining control contents executed by a control device of the present invention.

FIG. 2 is a diagram showing a relationship between a pressure increase value of a release pressure of a release side frictional engagement device and an engine speed change rate in a normal mode and a sport mode.

FIG. 3 is a schematic time chart showing the timing of increasing the release pressure of the release side frictional engagement device in the normal mode and the sports mode.

FIG. 4 is an example of a map showing a learned value of a release pressure increase value of the release side frictional engagement device in a normal mode and a sports mode.

FIG. 5 is an example of a map showing learning values of a release pressure increasing time of the release side frictional engagement device in a normal mode and a sports mode.

FIG. 6 is a diagram showing an overall control system according to the present invention.

FIG. 7 is a skeleton diagram showing an example of a gear train of an automatic transmission targeted by the present invention.

FIG. 8 is a diagram showing an engagement operation table of a friction engagement device for setting each shift speed in the automatic transmission.

FIG. 9 is a diagram showing a part of a hydraulic circuit that controls an engagement pressure when performing a shift between the second speed and the third speed.

FIG. 10 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. 11 is a time chart thereof.

FIG. 12 is a diagram schematically showing operating temperature regions of a high temperature map and a low temperature map.

[Explanation of symbols]

 17 Electronic Control Device for Engine 18 Hydraulic Control Device 19 Electronic Control Device for Automatic Transmission A Automatic Transmission E Engine

Claims (1)

[Claims] 1. A predetermined frictional engagement device is released and another frictional engagement device is engaged at the time of a gear shift end time after the engagement of the frictional engagement device on the engagement side is started at the time of gear shifting for engagement. In a control device for an automatic transmission connected to a driving force source for temporarily increasing the engagement pressure of the side frictional engagement device and selectively and temporarily increasing the rotational speed during gear shifting, the predetermined frictional engagement device is provided. Shift determining means for determining the shift for releasing the coupling device and releasing the other friction engagement device, and execution of control for increasing the rotational speed of the driving force source during the shift determined by the shift determining means. Rotation speed control determining means for determining presence / absence, and release of the disengagement side frictional engagement device at the shift end timing depending on presence / absence of increase control of the rotation speed of the driving force source determined by the rotation speed control determining means Boost control that changes the control content to temporarily increase the pressure Control apparatus for an automatic transmission, characterized by comprising a stage.