JPH09291838A - Compound controller for power unit and automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent shock in downshift to be performed by synchronizing the engine speed. SOLUTION: A device is so constituted that output torque of a power unit to which an automatic transmission is connected may be reduced in finishing of gear shift to be performed by the automatic transmission, and the revolution of the power unit may be increased in downshift by the automatic transmission in a state where the throttle opening is decreased. The device is provided with a gear shift detecting means (steps 11, 12) for detecting downshift in which the revolution of the power unit is increased by itself and gear shift in which increase of the revolution is not performed, and an output torque control means (steps 15, 18) for changing the content of reducing control of output torque in finishing of gear shift by the difference between gear shift detected by the gear shift detecting 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 a shift shock together with control of a power unit such as an engine or a motor. .

[0002]

2. Description of the Related Art Shock at the time of shifting in a vehicle equipped with an automatic transmission is caused by, for example, the inertia torque of a rotating element including an engine. The hydraulic pressure of a friction engagement device such as a brake is controlled, and the inertia torque is absorbed by these friction engagement devices. Further, by temporarily reducing the engine torque during shifting, the amount of energy absorbed by the friction engagement device is reduced, thereby reducing shift shock. More recently, in order to prevent a torsion caused in a drive system that transmits a driving force to a wheel due to an increase in engine output and a shock caused by restoration of the torsion, control is performed to reduce an engine torque at the end of a shift. Is starting to appear.

On the other hand, a technique for electronically controlling a throttle valve of an engine has also been developed and put into practical use. In this type of vehicle, the output of the engine is automatically controlled without operating the accelerator pedal by the driver. The engine output or the number of revolutions can be increased or decreased by itself according to the running state or control state of the vehicle such as gear shifting. An example thereof is described in JP-A-5-231525. The invention described in this publication increases the throttle opening by detecting the downshift during the downshift with the throttle valve closed.
This synchronizes the engine speed with the speed at the gear after the downshift, and on the premise of a so-called constant speed shift in which the downshift is executed in that state, the temporary opening of the throttle opening when the constant speed shift is executed. A hydraulic pressure limiting means is provided for preventing or suppressing an increase in the line pressure due to a temporary increase, and is configured to prevent a shock due to the frictional engagement device having an abrupt torque capacity during a downshift.

[0004]

In the above-described control device, for example, at the time of downshifting with the throttle valve closed, the engine speed is increased by opening the throttle opening. Increase. On the other hand, as described above, at the end of the shift, the engine torque is reduced by retarding the ignition timing or the like to prevent a shock due to the accumulation of the torsion torque in the power transmission system. Any of these controls is effective in reducing the shock at the time of gear shifting of a vehicle equipped with an automatic transmission, and it is preferable to be configured so that these controls can be executed together.

However, when the engine torque reduction control at the end of the shift is not executed, if the throttle valve is opened by the so-called constant speed shift and the engine torque increases, the inertia increases due to the increase of the engine speed, Torsional torque was accumulated in the power transmission system at the end of the shift, causing a shift shock.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device capable of effectively preventing a shift shock in a vehicle which executes the above-described constant speed shift. It is a thing.

[0007]

In order to achieve the above-mentioned object, the invention described in claim 1 connects the automatic transmission at the end timing of the shift by the automatic transmission. In a control device for an automatic transmission that reduces the output torque of the power device and increases the rotation speed of the power device during downshifting by the automatic transmission,
A shift detecting means for detecting a downshift accompanied by a control for increasing the rotational speed by the power unit and a shift without the controlling for increasing the rotational speed by the power unit, and a difference in the shift detected by the shift detecting means. Accordingly, the output torque control means for changing the content of the output torque reduction control at the end of the shift is provided.

Therefore, according to the first aspect of the invention, in the case of the downshift accompanied by the control for increasing the rotational speed of the power unit, at the end of the shift in accordance with the increase in the output torque of the power unit accompanying the control for increasing the rotational speed. Torque reduction control is performed, or the torque reduction control amount is set to substantially zero, and as a result, the rotation speed of the power unit is controlled in accordance with the downshift execution state, so gear shift shock is prevented. . On the other hand, in the case of other gear shifts, the increase control of the rotational speed of the power unit is not executed, so the torque reduction control of the power unit at the end of the gear shift is executed more largely than in the case of the above downshift, for example. To be done. Therefore, the twisting of the driving force transmission system at the end of the gear shift is prevented or suppressed, and the accumulation of the twisting torque and the shock resulting from it can be effectively prevented.

According to a second aspect of the present invention, the output torque of the power unit to which the automatic transmission is connected is reduced at the end timing of the shift by the automatic transmission, and the downshift is performed by the automatic transmission. In a combined control device of a power unit and an automatic transmission for increasing the rotational speed of the power unit, the contents of the output torque reduction control corresponding to the control of the rotational speed at the time of a downshift for increasing the rotational speed of the power unit. It is characterized in that it is provided with a changing means.

Therefore, according to the second aspect of the present invention, the control of the amount of reduction of the output torque and the execution timing of the reduction control according to the tendency of the change in the rotational speed of the power unit at the end of the shift, that is, the tendency of the change in the output. Since the contents are changed, the twisting of the power transmission system is suppressed at the time when the rotation speed of the rotating element such as the power unit is synchronized with the rotation speed of the gear after the downshift, and the rotation change at the time of reaching the synchronization is suppressed. It is smooth, and as a result, the shift shock can be improved.

[0011]

Next, the present invention will be described more specifically with reference to the drawings. First, the engine (power unit) E and the automatic transmission A that are the subject of the present invention will be described. FIG. 5 is an overall control system diagram of the engine E in which the automatic transmission A is connected. An electronic throttle valve 13, which is configured to electrically control the output and is driven by a servo 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, 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 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,
Signal from the pattern select switch, signal from the overdrive switch, signal from the C0 sensor that detects the rotational speed of the clutch C0, which will be described later, oil temperature of the automatic transmission, signal from the manual shift switch, signal from the sports mode switch , And signals output from the constant speed shift switch are input.

Here, the sport 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 (not shown), an instrument panel or the like. . 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 can be communicated with each other, 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. 6 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, that is, the input rotation speed, is provided.

Therefore, in the subtransmission unit 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. It will rotate 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 unit 22 is provided with 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 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 are used.
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. 7, a circle indicates an engaged state, a circle indicates an engaged state during engine braking, a triangle indicates either engaged or disengaged, and a blank indicates a disengaged state.

As shown in the operation table of FIG. 7, 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, the hydraulic circuit shown in FIG. 8 is incorporated in the hydraulic control device 18 described above.

In FIG. 8, 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. 8 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 / 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 discharge 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 figure is a port selectively communicated with a drain port. 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 communicated with the drain port.

The port 11 for outputting the D range pressure at the shift speed of the second speed or lower 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. 8, 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 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 pressure regulation level is controlled by a linear solenoid valve. SLU
Can be changed by If the spool 106 of the orifice control valve 105 is located at the position shown in the left half of the figure, the second brake B2 is connected to the oil passage 103 through the orifice control valve 105. It is possible to relieve pressure and thus control the drain speed from the second brake B2.

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. 9 schematically shows a control routine at the time of shifting in the normal power-on state, and it is judged whether or not a downshift from the third speed to the second speed is output as a 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 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 3rd speed to the 2nd speed is output, the 2-3 shift valve 71 is switched,
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 that 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 the 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, for example, by delaying the ignition timing (for example, Japanese Patent Laid-Open No. Hei 6)
-307527 publication).

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 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 input shaft speed NC0 approaches the second speed synchronous 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.

Incidentally, 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. 10. When a predetermined time elapses from the time 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 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 relation 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 and a rattling sensation due to the delay are 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 friction 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. 11, 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 shift control example 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. In addition to this, the downshift from the third speed to the second speed is performed by the electronic throttle valve 1
This also occurs when the vehicle speed decreases in the power-off state in which 3 is closed, or when the sport mode switch or constant speed shift switch is manually operated. Different controls are executed in each case.

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. After performing the processing of the input signal (step 10), the so-called clutch toe
A downshift from the third speed, which is a clutch shift, to the second speed is determined (step 11). If a negative determination is made in step 11, the process returns without performing any control, and if an affirmative determination is made, it is determined whether or not the sport mode is set (step 12). Therefore, steps 11 and 12 correspond to the shift detecting means in the present invention.

As described above, the sport mode is a gear shift mode in which gear shifting is performed based on switch operation. As the form of the switch, the shift device is provided with each shift speed position and each shift lever is turned on. 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
This may be performed by determining whether or not signals are output from these switches (for example, Japanese Patent Laid-Open No. 6-307527).
Reference).

If the determination in step 12 is negative 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). ). In that case,
The second brake pressure is increased (sweep up) at the end of the inertia phase. At the same time, the torque down control of the engine E is executed at the end of the shift (step 15). this is,
As one example, it is executed by retarding the ignition timing. Therefore, it is possible to effectively prevent the torsion torque from being accumulated in the power transmission system and the shock from being generated accordingly (see, for example, Japanese Patent Application No. 7-70672).

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 power is off, the boosting control of the second brake B2 on the release side as in step 15 is not executed. Therefore, the second brake pressure is changed as shown by the broken line in FIG.

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). This constant speed shift is a shift control in which the engine speed Ne is increased to the synchronous speed at the shift stage after the downshift, and the downshift is executed in this state. The electronic throttle valve 13 is set to the electronic control unit 17 for the engine. It is executed by temporarily opening by. Therefore, it is possible to prevent the deceleration for increasing the engine speed from suddenly increasing to cause a shock.

Further, the torque down control at the end of the shift is executed (step 18). This control can also be executed by retarding the ignition timing in the same manner as step 15, but the engine speed is positively increased to the optimum value for the constant speed shift. , Is set in consideration of how to increase the number of revolutions.

A conceptual example is shown in FIGS. 2 and 3. FIG. 2 shows the relationship between the rate of change in engine speed Ne (Ne dot) and the amount of torque down ΔD (torque down time ΔT), and FIG. 3 shows
As an example, the change in the engine speed Ne during the downshift from the third speed to the second speed is shown. That is, the synchronous speed of the second speed can be obtained based on the vehicle speed (or the output shaft speed) and the gear ratio of the second speed, and the engine speed Ne after the start of the downshift is relative to the synchronous speed. The change rate (Ne dot) at the time when the number of rotations becomes low by a preset value ΔNbe is detected. The time point at which the rate of change (Ne dot) is detected may be a time point that is a preset time Tbe before the time point at which the second-speed synchronous rotation speed is obtained by the synchronous prediction.

In this way, the engine speed N during shifting is
The state of the throttle opening of the engine E is indirectly detected by detecting the change of e. And the detected engine speed change rate (Ne dot)
Based on the above, the torque down amount ΔD and / or the torque down time ΔT at the time of constant speed shift can be obtained from the diagram of FIG. As shown in FIG. 2, the torque down amount ΔD and / or the torque down time ΔT at the constant speed shift are smaller than the control amount (broken line in FIG. 2) at the time of shifting in the normal power-on state ( (Solid line in FIG. 2). Therefore, the torque down signal at the time of constant speed shift is as shown by the chain line in FIG. As a result, torsional torque is prevented from accumulating in the power transmission system and a shift shock is prevented from occurring. Therefore, steps 15 and 18 correspond to the output torque control means in the first aspect of the invention and the means for changing the content of the torque down control in the second aspect of the invention.

The above-described torque down control is executed in connection with gear shifting, and the progress state of the gear shifting is greatly affected by the conditions of supply / discharge of hydraulic pressure to / from the friction engagement device involved in gear shifting. That is, when the oil temperature in the automatic transmission A is low, the viscosity of the oil (fluid) is high, so that the supply and discharge of the hydraulic pressure to the friction engagement device is delayed. Therefore, it is preferable to correct the torque down amount or the torque down time based on the oil temperature. For example, as shown in FIG. 4, it is preferable to correct the engine speed change rate (Ne dot). Specifically, the lower the oil temperature, the smaller the engine speed change rate (Ne dot) is set.
With this control, it is possible to prevent the engine E from rising because the throttle opening is not increased and the engine speed Ne is not increased when the gear shift does not proceed due to the high viscosity of the oil. .

The constant velocity shift is not limited to the downshift in the sports mode, but is performed by turning on the constant velocity shift switch. Therefore, step 12 in FIG. It may be replaced with a step (step 12 ') for determining whether or not is ON (for example, see Japanese Patent Application No. 7-215892).

The reduction control of the output torque of the power unit in the present invention is not limited to the ignition timing retard control described above, but may be performed by a method such as reducing the fuel supply amount or, in the case of a motor, reducing the current. Alternatively, a plurality of controls for reducing the output torque may be performed simultaneously.
In that case, an optimum value can be set as the control amount when the above-mentioned so-called constant speed shift is executed, and for example, the output torque control is performed at the end of the gear shift depending on the degree of increase in the rotational speed of the power unit. The reduction amount of the output torque of the power plant may be changed.

Further, 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 the case of performing 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. 6 and 8. The power unit may be another power unit such as an electric motor other than the engine.

The characteristic configurations of the present invention disclosed based on the above specific examples will be listed below. That is, when the content of the output torque reduction control of the power unit is changed at the end of the downshift, the content of the torque reduction control can be changed based on the rate of change of the rotational speed of the power unit.

The change of the content of the torque reduction control can be executed in the sports mode (manual shift mode) in which the shift speed is selected based on the manual operation. Alternatively, it can be executed in the case of the downshift accompanied by the so-called constant speed shift described above. Further, the oil temperature of the automatic transmission can be taken in as a parameter for changing the content of the torque down control, and the content of the torque down control can be changed according to the oil temperature.

On the other hand, when the content of the output torque reduction control is changed according to the changing state of the rotational speed of the power unit, the control is executed in the sports mode, or downshifting in the constant speed shift is performed. It is also possible to change the control content based on the oil temperature of the automatic transmission.

[0077]

As described above, according to the first aspect of the present invention, when the rotational speed of the power unit is increased in association with the downshift, the output torque reduction control normally executed at the end of the shift is performed. , The number of revolutions or the output torque of the power unit is adapted to the downshift, and the inertia force of the power unit suddenly acts as a braking force, or Torsional torque is not released after being accumulated in the power transmission system, and a shock due to gear shifting can be effectively prevented. Further, in the case of a normal gear shift other than the so-called constant speed shift, the torque reduction control at the end of the gear shift is executed, so that it is possible to prevent a shock caused by a torsion torque or the like.

According to the second aspect of the present invention, the content of the output torque reduction control, such as the amount of reduction and the duration of the reduction control, is changed according to the state of change in the rotational speed of the power unit. It is possible to more reliably prevent the twisting and the abrupt rotation change of the power transmission system at the final stage, and as a result, it is possible to effectively prevent the shock accompanying the gear shift.

[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 torque down amount and a torque down time and an engine speed change rate in a normal mode and a sports mode.

FIG. 3 is a diagram schematically showing a change in engine speed during a downshift from third speed to second speed.

FIG. 4 is a diagram showing a relationship of users used to determine an engine speed change rate with oil temperature as a parameter.

FIG. 5 is a diagram showing an overall control system according to the present invention.

FIG. 6 is a skeleton diagram showing an example of a gear train of an automatic transmission targeted by the present invention.

FIG. 7 is a diagram showing an engagement operation table of a friction engagement device for setting each shift speed in the automatic transmission.

FIG. 8 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. 9 is a flow chart schematically showing a control routine for performing a sweep control of the engagement pressure of the second brake on the release side at the time of downshifting from the third speed to the second speed.

FIG. 10 is a time chart thereof.

FIG. 11 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 (2)

[Claims] 1. An output torque of a power unit to which the automatic transmission is connected is reduced at the end of shifting by the automatic transmission, and the rotational speed of the power unit is increased during downshifting by the automatic transmission. In a combined control system of a power plant and an automatic transmission, a shift detecting means for detecting a downshift accompanied by control for increasing the number of revolutions of the power plant and a shift not involving control for increasing the number of revolutions of the power plant. And an output torque control means for changing the content of the output torque reduction control at the end of the gear shift according to the difference in gear shift detected by the gear shift detection means. Complex control device. 2. The output torque of a power unit to which the automatic transmission is connected is reduced at the end of shifting by the automatic transmission, and the rotational speed of the power unit is increased during downshifting by the automatic transmission. A combined control device of a power plant and an automatic transmission, comprising means for changing the content of the output torque reduction control in response to the control of the rotational speed of the power plant during a downshift to increase the rotational speed of the power plant. A combined control device for a power unit and an automatic transmission, characterized by: