JP3010653B2 - Transmission control device for automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission that limits the output of an engine during a shift to reduce a shift shock, and particularly to an engine in an upshift. At the start of the output reduction.

<Prior art> As one of automatic transmissions for vehicles, the supply and discharge of pressure oil to and from frictional engagement elements such as clutches and brakes connected to rotating elements such as a plurality of rotating drums and gears are controlled. There is known a device in which the gear ratio is automatically switched in accordance with the driving state of the vehicle by selectively engaging the friction engagement elements of the vehicle.

In the case of such an automatic transmission, since the driver continues to depress the accelerator pedal regardless of the shift operation by the automatic transmission, the release timing of the release-side friction engagement element and the engagement-side friction engagement element If the engagement timing is not appropriate, there is a disadvantage that the engine speed rapidly increases when the friction engagement element on the engagement side at which the shift ends is engaged, and a large shift shock occurs. Therefore, in general, the control oil pressure supplied after the transmission of the shift start signal is set to an optimum value based on the throttle opening at this time, the engine speed, the vehicle speed, or the like, or the rotation change rate of the rotating element during the shift. Controls the hydraulic pressure supplied to the frictional engagement element so that follows the target change rate set in advance.

In recent years, an output control device that forcibly reduces the output of the engine regardless of the amount of depression of the accelerator pedal by the driver has been considered, and this output control device is used to reduce shift shock during shifting by the automatic transmission. That, Tokubo Sho 63
-53388. According to this, the control oil pressure is supplied to the friction engagement element on the engagement side as usual during the gear shifting operation by the automatic transmission, and in parallel with this, the output of the engine is output regardless of the amount of depression of the accelerator pedal by the driver. This is forcibly suppressed, and the inertia torque of the engine during gear shifting is reduced to reduce shock when the friction engagement element is engaged.

The timing for starting the output reduction of the engine at the time of this shift operation is set based on, for example, the rotation change rate of the engine, or set after a fixed time after outputting the shift start signal, or during an upshift, Select the time when the difference between the speed of the transmission input shaft calculated based on the speed before the shift and the speed of the transmission output shaft and the actual speed of the transmission input shaft reaches a predetermined value, etc. are doing.

As means for reducing the output of the engine, it is common to delay the ignition timing, reduce the intake air amount or the fuel supply amount, or stop the fuel supply or change the supercharging pressure or the air-fuel ratio. However, as a special type, there is also known a type in which the compression ratio of the engine is reduced.
As the means for reducing the amount of intake air, a supercharger such as a throttle device or a variable resonance supercharger operated by an actuator or a variable intake device can be used.

<Problem to be Solved by the Invention> The method of suppressing the shift shock of the automatic transmission using the output control device can increase the durability of the friction engagement element and can operate regardless of the magnitude of the engine output. There is an advantage that one automatic transmission can also be used. In this case, it is desirable that the timing to start the output reduction of the engine is the time when the engagement of the new friction engagement element actually starts from the viewpoint of reducing the shift shock.

However, in the prior art, as described above, the start point of the output reduction of the engine is set based on the rotation change rate of the engine, or set at a fixed time after outputting the shift start signal, or During the shift, the difference between the actual speed of the transmission input shaft and the speed of the transmission input shaft, which is calculated based on the speed before the shift and the speed of the transmission output shaft, reaches a predetermined value. It is the time when it was done.

For this reason, in the conventional method, there is a possibility that the control timing may be shifted due to variations in the hydraulic pressure at the time of gear shifting and changes with time of the friction engagement element and the like. Further, when the start point of the output reduction of the engine is selected based on the rotation speed of the transmission input shaft, in addition to the start of the output reduction after the engagement of the new friction engagement element is started, Due to the calculation delay of the calculation device, the change in the torque of the transmission output shaft in the initial stage of the shift becomes relatively steep, and the shift shock cannot be sufficiently reduced.

<Means for Solving the Problems> A shift control device for an automatic transmission according to the present invention includes a transmission input shaft to which a driving force from an engine having output control means is input, and a shift for outputting the driving force to driving wheels. Speed change control means for switching a speed ratio by engaging or disengaging a plurality of frictional engagement elements provided between the frictional engagement element and a hydraulic pressure for supplying a control hydraulic pressure set to the frictional engagement element In a shift control device for an automatic transmission including a supply unit, an acceleration state detection unit that determines an acceleration state of the vehicle, a shift-up signal is output by the shift control unit, and the acceleration state is detected by the acceleration state detection unit. When it is determined that the actual shift start is started immediately after the engagement of the engagement-side frictional engagement element is started. Last detection Means for outputting a signal for reducing the engine output to the output control means when it is determined by the means to determine immediately before the actual shift start timing. A rotational speed change rate detecting means for detecting a rotational speed change rate of the machine input shaft, wherein the rotational speed change rate detected by the rotational speed change rate detecting means changes to a positive range or less. It is characterized in that it is determined that it is immediately before the actual shift start timing.

Further, in the shift control device for an automatic transmission according to the present invention, in the shift control device for an automatic transmission according to claim 1, the acceleration state detecting means detects the rotation speed change rate detected by the rotation speed change rate detection means. Is larger than the predetermined value.
It is characterized in that it is determined that the vehicle is in an acceleration state when the speed is equal to or more than a predetermined value.

<Operation> As a result, when it is determined that the vehicle is accelerating due to the output of the upshift signal, the rate of change of the rotation speed of the transmission input shaft changes to a positive or lower range, and the actual speed is increased. A signal for reducing the engine output is output when it is determined that it is immediately before the gear shift start timing, so that the output of the engine is reduced simultaneously with the start of engagement of the frictional engagement element on the engagement side, and the transmission output is reduced. It is possible to maintain a gradual change in the torque of the shaft, thereby preventing a sudden increase in the engine output and suppressing the occurrence of a shift shock.

<Embodiment> As shown in FIG. 1 showing a schematic structure of a portion of an automatic transmission in an embodiment of a shift control device for an automatic transmission according to the present invention, a crankshaft 12 of an engine 11 is provided with an impeller 14 of a torque converter 13. Are integrally connected. The torque converter 13 includes the impeller 14, the turbine 15, and the stator 16
And the one-way clutch 17, the stator 16 is coupled to the transmission case 18 via the one-way clutch 17, and the one-way clutch 17 causes the stator 16 to rotate in the same direction as the crankshaft 12. The rotation in the opposite direction is not allowed. Then, the torque transmitted to the turbine 15 is transmitted to an input shaft 19 of a gear transmission that achieves a forward four-speed reverse one-speed stage disposed at the rear of the torque converter 13.

This gear transmission includes three sets of clutches 20, 21, 22; two sets of brakes 23, 24; a set of one-way clutch 25; and a set of Ravigneaux-type planetary gear mechanism 26. The planetary gear mechanism 26 includes a ring gear 27, a long pinion gear 28, a short pinion gear 29, a front sun gear 30, a rear sun gear 31, and a carrier 32 rotatably supporting the pinion gears 28 and 29 and rotatably fitted to the input shaft 19. It is composed of

The ring gear 27 is connected to an output shaft 33, and the front sun gear 30 is a kick down drum 34 and a front clutch.
The rear sun gear 31 is connected to the input shaft 19 via the rear clutch 21. The carrier 32 is connected to the transmission case 18 via a low reverse brake 24 and a one-way clutch 25 disposed in parallel with each other, and a four-speed clutch disposed at the rear end of the gear transmission. It is connected to the input shaft 19 via 22.

The kick down drum 34 has a kick down brake.
The torque transmitted through the Ravigneaux-type planetary gear mechanism 26 is transmitted from the drive gear 35 fixed to the output shaft 33 to the drive shaft side of the drive wheels (not shown) by being integrally connected to the transmission case 18 by the drive shaft 23. Is done.

Each of the clutches 20 to 22 and the brakes 23 and 24, which are friction engagement elements, is constituted by a hydraulic device including an engagement piston device or a servo device, and is connected to the impeller 14 of the torque converter 13 by an oil. It is operated via a hydraulic control device 37 by the pressure oil generated by the pump 36.

The detailed configuration and operation are described in, for example,
No. 54270, JP-A-58-46248 or JP-A-61-46248
As is well known in Japanese Patent No. 31749, etc., the selective engagement of each friction engagement element is performed according to the position selected by the driver of the select lever provided in the driver seat (not shown) and the driving state of the vehicle. Various gear stages are automatically achieved via the hydraulic control device 37 based on commands from an electronic control unit (hereinafter referred to as ECU) 38 for controlling the operating state of the engine 11. It has become.

The select pattern by the select lever is P
(Parking), R (reverse), N (neutral), D (forward three-stage automatic transmission or forward four-stage automatic transmission), 2 (forward two-stage automatic transmission), L (first speed fixed). By operating an auxiliary switch (overdrive switch) (not shown) with the select lever selected to the D position, it is possible to switch between forward three-speed automatic shift and forward four-speed automatic shift.

When the select lever is held at each position of the select pattern, how the respective friction engagement elements work is as shown in the operation element diagram of FIG. In the reference symbols in the drawing, the mark ○ indicates that the clutch is engaged by hydraulic operation, while the mark ● indicates that the clutch is engaged only when L (first speed fixed) is selected. This indicates that a mechanically engaged state is established when (forward three-stage automatic shift or forward four-stage automatic shift) or 2 (forward two-stage automatic shift) is selected.

For example, when shifting from 1st gear to 2nd gear, the rear clutch
In addition to the engagement of 21, the kick-down brake 23 is newly engaged, and as shown in FIG. 3 showing a schematic structure of a main part of a hydraulic circuit in the hydraulic control device 37 at this time,
A kick-down servo 39 for controlling the operation of the kick-down brake 23 is connected to a 1-2 shift valve 40 via an oil passage 41. The 1-2 shift valve 40 is connected to a shift control valve 42 and a shift control valve. The valve 43 is connected via oil passages 44 and 45, respectively.

A pair of non-energized closed shift control solenoid valves 46 and 47 for controlling the operation of the shift control valve 43 at the first speed.
Since the oil passages 48 and 49 are both open and the oil passages 48 and 49 are opened, the center spool 50 of the shift control valve 43 is displaced to the left in FIG. 3 and the spool 51 of the 1-2 shift valve 40 is connected to the oil port EX as shown in FIG.
It is displaced to the left. As a result, the oil passage 41 becomes 1-2
The piston 53 is returned to the right side in FIG. 3 by the spring force of the compression coil spring 52 of the kick down servo 39 in communication with the oil drain port EX of the shift valve 40, and the kick down brake
23 has been disengaged. Also, the ECU is attached to one of the two oil passages 54 and 55 connected to the shift control valve 42 and is connected to the ECU.
The duty ratio of the non-energized closed hydraulic control solenoid valve 56 that is duty-controlled by 38 is set to 100%, and no oil pressure acts on the oil passage 54. As a result, the spool 57 of the shift control valve 42 is displaced to the left in FIG.
44 communicates with the oil drain port EX of the shift control valve 42.

When performing an upshift from this state to the second speed, the ECU 38 operates one of the shift control solenoid valves 46 to block the oil passage 48 based on the traveling conditions of the vehicle, so that the center spool 50 of the shift control valve 43 In FIG. 3, the pressure oil from the oil pump 36 (hereinafter referred to as line pressure) is displaced to the right and shifted by 1-2 from an oil passage 58 connected to the shift control valve 43 through an oil passage 45. It is delivered to valve 40. Therefore, the spool 51 of the 1-2 shift valve 40 is displaced to the right in FIG.
-2 It communicates via the shift valve 40. On the other hand, since the duty ratio of the hydraulic control solenoid valve 56 is reduced by the ECU 38, the line pressure acts on the oil passages 54 and 55, and the spool 5 of the shift control valve 42
Due to the pressure receiving area difference of 7, the spool 57 is displaced to the right in FIG. 3, and the oil passages 44 and 55 communicate with each other via the shift control valve 42. As a result, the line pressure from the oil passage 55 is supplied to the kick down servo 39 through the oil passages 44 and 41, and the piston 53 is moved to the third position.
In the figure, the kick down brake 23 is displaced to the left to tighten the kick down drum 34.

As shown in FIG. 4 showing the control concept of the engine 11 in the present embodiment, a base end portion of an intake pipe 60 is connected to a combustion chamber 58 of the engine 11 via an intake valve 59. The tip of 61 is connected to the combustion chamber 58 via an exhaust valve 62.
An air cleaner element 63 is provided at the tip of the intake pipe 59.
Is mounted.

In the middle of the intake pipe 60, a throttle body 67 incorporating a throttle valve 66 for changing the opening degree of an intake passage 65 formed by the intake pipe 60 and adjusting the amount of intake air supplied into the combustion chamber 58 is provided. Is interposed. As shown in FIG. 4 and FIG. 5 showing an enlarged cross-sectional structure of a cylindrical portion of the throttle body 67, both ends of a throttle shaft 68 to which a throttle valve 66 is integrally fixed are rotated on the throttle body 67. It is freely supported. An accelerator lever 69 and a throttle lever 70 are coaxially fitted to one end of the throttle shaft 68 projecting out of the intake passage 65.

A bush 72 and a spacer 73 are interposed between the throttle shaft 68 and the cylinder portion 71 of the accelerator lever 69, whereby the accelerator lever 69 is rotatable with respect to the throttle shaft 68. Further, the washer 74 and the nut 75 attached to one end of the throttle shaft 68 prevent the accelerator lever 69 from coming off the throttle shaft 68. An accelerator pedal 76 operated by the driver is connected to the accelerator lever 69 via a cable 77, and the accelerator lever 69 rotates with respect to the throttle shaft 68 according to the amount of depression of the accelerator pedal 76. It has become.

On the other hand, the throttle lever 70 is fixed integrally with the throttle shaft 68, so that by operating the throttle lever 70, the throttle valve 66 is moved to the throttle shaft 68.
It rotates with it. A stopper 79 is formed on a part of the throttle lever 70 so as to be engaged with a claw 78 formed on a part of the accelerator lever 69. The claw 78 and the stopper 79 are connected to the throttle valve 66. When the throttle lever 70 is turned in the direction in which the throttle valve 66 opens, or when the accelerator lever 70 is turned in the direction in which the throttle valve 66 closes, the positional relationship is set such that they are locked to each other.

Between the throttle body 67 and the throttle lever 70, a torsion coil spring 80 for pressing the stopper 79 of the throttle lever 70 against the claw 78 of the accelerator lever 69 to urge the throttle valve 66 in the opening direction is provided with a throttle shaft 68. It is mounted coaxially with the throttle shaft 68 via a pair of cylindrical spring receivers 81 fitted to the throttle shaft 68. Also, between the stopper pin 82 protruding from the throttle body 67 and the accelerator lever 69, the claw portion 78 of the accelerator lever 69 is pressed against the stopper 79 of the throttle lever 70 so that the throttle valve 66 is pressed.
The torsion coil spring 83 urges the accelerator pedal 76 in the closing direction to give the accelerator pedal 76 a detent feeling.
Throttle shaft 68 to the cylinder 71 of the accelerator lever 69 via 84
And is mounted coaxially.

The distal end of the throttle lever 70 is connected to the distal end of a control rod 87 whose base end is fixed to the diaphragm 86 of the actuator 85. A pressure chamber 88 formed in the actuator 85 is provided with a stopper 79 of the throttle lever 70 together with the torsion coil spring 80 and a claw portion of the accelerator lever 69.
A compression coil spring 89 that urges the throttle valve 66 in the direction of opening by pressing it against 78 is incorporated. Then, the spring force of the torsion coil spring 83 is set to be larger than the sum of the spring forces of these two springs 80 and 89, whereby the accelerator pedal 76 is depressed or the pressure inside the pressure chamber 88 is reduced. The throttle valve 66 does not open unless a negative pressure greater than the sum of the spring forces of the two springs 80 and 89 is applied.

A connection pipe 91 is connected to a surge tank 90 which is connected to the downstream side of the throttle body 67 and forms a part of the intake passage 65.
The vacuum tank 92 is in communication with the vacuum tank 92, and a check valve 93 that allows only the movement of air from the vacuum tank 92 to the surge tank 90 is interposed between the vacuum tank 92 and the connection pipe 91. I have. As a result, the pressure in the vacuum tank 92 is set to a negative pressure substantially equal to the lowest pressure in the surge tank 90.

The vacuum tank 92 and the actuator 85
The pressure chamber 88 is communicated with the pressure chamber 88 via a pipe 94, and a non-energized first output control solenoid valve 95 is provided in the middle of the pipe 94. That is, the output control solenoid valve 95 incorporates a spring 98 for urging the plunger 96 against the valve seat 97 so as to close the pipe 94.

Further, a pipe 99 communicating with the intake passage 65 upstream of the throttle valve 66 is connected in the middle of a pipe 94 between the output control electromagnetic valve 95 and the actuator 85. In the middle of the pipe 99, a second output control solenoid valve 100 that is open when not energized is provided. In other words, the output control solenoid valve 100 incorporates a spring 102 for urging the plunger 101 to open the pipe 99, and opens the valve seat 103 of the output control solenoid valve 100 connected to the pipe 99. keeping.

In this embodiment, the intake negative pressure is used as the pressure fluid for operating the actuator 85. However, the actuator 85 is operated by using pressure oil or the like from the oil pump 36 interlocked with the engine 11.
It is of course also possible to operate.

The two output control solenoid valves 95 and 100 have the ECU 38
Are connected, and duty on / off of energization to the solenoid valves 95 and 100 is controlled based on a command from the ECU 38. For example, output control solenoid valve 9
When the duty ratio of 5,100 is 0%, the actuator 85
The pressure chamber 88 of the intake passage 65 upstream of the throttle valve 66
The atmospheric pressure becomes substantially equal to the internal pressure, and the opening degree of the throttle valve 66 corresponds to the depression amount of the accelerator pedal 76 on a one-to-one basis. Conversely, if the duty ratio of the output control solenoid valves 95 and 100 is 10
In the case of 0%, the pressure chamber 88 of the actuator 85 has a negative pressure substantially equal to the pressure in the vacuum tank 92, and the control rod 87 is pulled up diagonally to the left in FIG. Closed regardless of the amount of depression.

In this way, by adjusting the duty ratio of the output control solenoid valves 95 and 100 during shifting by the automatic transmission,
Throttle valve regardless of the amount of depression of accelerator pedal 76
The output of the engine 11 can be adjusted by changing the opening degree of the engine 66.

In this embodiment, the opening degree of the throttle valve 66 is controlled simultaneously by the accelerator pedal 76 and the actuator 85.However, two throttle valves are arranged in series in the intake passage 65, and one throttle valve is It is also possible to connect only the pedal 76 and connect the other throttle valve only to the actuator 85, and control these two throttle valves independently.

As described above, in the present embodiment, the throttle device operated by the actuator 85 is employed as the output control means of the engine 11, but in addition to the supercharger such as the variable resonance supercharger or the variable intake device, the ignition timing is delayed. Alternatively, a fuel supply amount may be reduced, a fuel supply may be stopped, a boost pressure or an air-fuel ratio may be changed, or a compression ratio of the engine 11 may be reduced. It is also possible to control the output control device in combination with the output control of the engine 11 when the drive wheels slip or the output control of the engine 11 when the vehicle turns.

On the other hand, on the downstream end side of the intake pipe 60, a combustion chamber of the engine 11 is provided.
Fuel injection nozzles 104 of a fuel injection device for injecting fuel (not shown) into 58 are provided corresponding to the respective cylinders of the engine 11 (in this embodiment, a four-cylinder internal combustion engine is assumed). Controlled fuel supply solenoid valve 105
Is supplied to the fuel injection nozzle 104 via the. In other words, by controlling the valve opening time of the fuel supply solenoid valve 105, the amount of fuel supplied to the combustion chamber 58 is adjusted so that a predetermined air-fuel ratio is achieved and the ignition plug 106 ignites in the combustion chamber 58. It has become.

The ECU 38 includes a throttle opening sensor 107 attached to a throttle body 67 for detecting the opening of a throttle valve 66, and the gear transmission attached to a transmission case 18 so as to face the fourth-speed clutch 22. Input shaft 19
An input shaft rotation speed sensor 108 for detecting the rotation speed of the vehicle, a vehicle speed sensor 109 mounted on the transmission case 18 so as to face the drive gear 35 to detect a vehicle speed, and assembled to the kick down servo 39. A kick-down servo switch (hereinafter referred to as a K / D servo switch) 111 for detecting the start of the effect of the brake band 110 of the kick-down brake 23 on the kick-down drum 34 is connected to the throttle opening sensor. 107, engine speed sensor
Output signals from the vehicle speed sensor 109 and the K / D servo switch 111 are sent.

When the automatic transmission is not shifting, the ECU 38 turns off the pair of output control solenoid valves 95 and 100, that is, sets the duty ratio to 0%.
The output of the engine 11 is controlled according to the amount of depression of the accelerator pedal 76 by the driver.

On the other hand, when a shift signal is output from the ECU 38 to the hydraulic control device 37 of the automatic transmission, for example, when a shift signal of the second speed is output during traveling at the first speed, FIG. 6 showing a flowchart of the operation at this time. As shown in FIG. 7, which shows a change state of the rotation speed of the input shaft 19 of the gear transmission, and a relationship between a rotation change rate of the input shaft 19 and a rotation state of the output shaft 33 of the gear transmission. At S1, the flag indicating that the rate of change of the rotation speed of the input shaft 19 of the gear transmission is smaller than a preset threshold value a, that is, the flag indicating that the vehicle is not accelerating, is reset to F ₁ = 0, and the engine 11 controls the output. F ₂ =
Reset to zero.

Needless to say, the threshold value a needs to be set to a value at which the rate of change in the rotation speed of the input shaft 19 can be detected.

Then, in S2, the power supply to the shift control solenoid valve 46 is stopped, and the line pressure is changed from the shift control valve 43 to the 1-2 shift valve 40.
Supply to Next, in S3, the energization of the hydraulic control solenoid valve 56 is stopped, and in S4, it is determined whether or not the K / D servo switch 111 is on. The energization of the solenoid valve 56 is turned off. in this way,
By turning off the energization of the hydraulic control solenoid valve 56 for a certain period of time, the kick-down servo 39
The line pressure is supplied as it is, and the gap between the brake band 110 of the kick down brake 23 in the released state and the kick down drum 34 is eliminated to reduce the shift time.

When the K / D servo switch 111 is turned off, it is determined in S5 whether or not the rate of change of the rotation speed of the input shaft 19 is equal to or greater than a predetermined threshold a.If not, the vehicle is not accelerating in S6. Is set to F ₁ = 1, and the process proceeds to step S7. On the other hand, if the rotational speed change rate of the input shaft 19 is equal to or larger than the threshold a, the process directly proceeds to step S7.

In step S7, the initial duty ratio of the hydraulic control solenoid valve 56 is set to the throttle opening sensor 10 so that the turbine 15 of the torque converter 13 has a predetermined rotation change rate.
7 and determined based on the detection signal from the vehicle speed sensor 109,
This is output to the hydraulic control solenoid valve 56. And at S8
F ₁ = 1 if it is determined whether not the F ₁ = 1, that is, when it is determined that the vehicle is accelerating, if the flag is either F ₂ = 1 indicating that this time is being output control in S9 Is determined.

Then, if it is determined that F ₂ = 1 is not satisfied, that is, if the engine 11 is not under output control, it is determined in S10 whether or not the rate of change in the rotational speed of the input shaft 19 is equal to or less than a preset threshold value b. b or less, that is, kick down brake 23
If it is determined that the tightening of the brake band 110 with respect to the kick down drum 34 has just started, S11
Starts output control for the engine 11. In particular,
Based on the detection signals from the throttle opening sensor 107 and the vehicle speed sensor 109 at this time, the ECU 38 determines the duty ratio of the output control solenoid valves 95 and 100 by calculation or according to a map set in advance, and outputs a corresponding control voltage. Output to the control solenoid valves 95 and 100. This allows the actuator
As a result, the throttle rod 66 is closed irrespective of the amount of depression of the accelerator pedal 76, and the output of the engine 11 is limited. State. Thus, the output of the engine 11 is limited, and F ₂ = 1 is set in S12.

The threshold value b may be set to an optimal value in advance based on the calculation speed of the ECU 38, control delay, or the like, or may be read from a map that is divided in advance by the throttle opening, the vehicle speed, and the like.

Next, in S13, the input shaft speed sensor 108 and the vehicle speed sensor
Based on the rotational speeds of the input shaft 19 and the output shaft 33 detected by 109, it is determined in S14 whether or not the first-speed synchronization has been lost. If the first-speed synchronization has not been lost, per unit time is determined in S15. Is determined based on the detection signals from the throttle opening sensor 107 and the vehicle speed sensor 109 at this time, and this is output to the hydraulic control solenoid valve 56 in S16, and the process returns to step S8.

If it is determined in S8 that F ₁ = 1, that is, if it is determined that the vehicle is not accelerating, the process jumps to step S14 to determine whether the first-speed synchronization has been lost without performing the control method according to the present invention. . In S9, F ₂ = 1, that is, the engine 11
Is determined to be under output control, and in S10, the rotational speed change rate 入 力 of the input shaft 19 is not less than or equal to the threshold value b, that is, the tightening of the brake band 110 with respect to the kick down drum 34 of the kick down brake 23 is not yet completed. If it is determined that it has not started, jump to the step of S13, respectively
Based on the rotation speeds of the input shaft 19 and the output shaft 33 detected by the input shaft rotation speed sensor 108 and the vehicle speed sensor 109, it is determined in S14 whether the first speed is out of synchronization, and the rotation speed change rate of the input shaft 19 is determined. Steps S15 and S16 are repeated until is less than or equal to the threshold b.

In this manner, in the routines of S13 to S16, the duty ratio of the hydraulic control solenoid valve 56 is gradually decreased until the synchronization of the first speed is released, the hydraulic pressure for the kickdown servo 39 is increased, and the synchronization of the first speed is released.

On the other hand, if it is determined that the synchronization of the first speed at S14 out, a flag indicating that it is in the output control at S17 is F ₂
= 1, that is, if F ₂ = 1 is not satisfied, that is, if it is determined that the output of the engine 11 is not being controlled, the output control for the engine 11 is performed in S18 in the same manner as the operation in S11, and in S19, F ₂
= 1 and the process proceeds to step S19. This operation is performed when it is determined in S8 that the vehicle is not accelerating, and when it is determined in S17 that F ₂ = 1, that is, when it is determined that the engine 11 is performing output control, the next S20 Jump to

Then, in S20, the throttle opening sensor 107 at this time is
Based on the detection signal from the vehicle speed sensor 109 and the change rate of the duty ratio of the hydraulic control solenoid valve 56, the change amount is determined by calculation or by a map set in advance, and this is output to the hydraulic control solenoid valve 56.

As described above, in the present embodiment, the duty ratio of the hydraulic control solenoid valve 56 is changed during the output control of the engine 11 to reduce the hydraulic pressure supplied to the kick-down servo 39. There is no problem that the engagement timing of the kick-down brake 23 is earlier than usual by an amount corresponding to the reduced inertia torque, and the torque change of the output shaft 33 of the gear transmission is relatively steep. The torque change rate of the output shaft 33 can be kept gradual while decreasing. As a result, there is no danger that the output of the engine 11 will suddenly rise and a shock will occur, and it is possible to maintain good ride comfort.

Next, in S21, the input shaft speed sensor 108 and the vehicle speed sensor
Based on the number of rotations of the input shaft 19 and the output shaft 33 detected by 109, it is determined whether or not the synchronization of the second speed is completed in S22. If the synchronization of the second speed is not completed, the unit is determined in S23. The decrease rate of the duty ratio per time is determined based on the detection signals from the throttle opening sensor 107 and the vehicle speed sensor 109 at this time, and this is output to the hydraulic control solenoid valve 56 in S24.

In this manner, the second-speed synchronization is performed by increasing the hydraulic pressure for the kick-down servo 39 by gradually decreasing the duty ratio of the hydraulic control solenoid valve 56 until the second-speed synchronization is completed.

If it is determined in S22 that the second-speed synchronization has been completed, in S25 the ECU 38 turns off the output control solenoid valves 95 and 100, that is, sets the duty ratio to 0%, and depresses the accelerator pedal 76 by the driver. To return to the normal state in which the output of the engine 11 is controlled in accordance with. At the same time, the power supply to the hydraulic control solenoid valve 56 is turned off in S26, the line pressure from the oil pump 36 is supplied to the kick down servo 39, and the kick down drum 34 is completely tightened with the brake band 110 to the second speed. Completes the speed change operation.

In FIG. 7, a chain line indicates a conventional case in which the output control start timing is set based on the rotation speed of the input shaft 19 without being based on the rotation change rate of the input shaft 19 of the gear transmission. As is clear from this graph, in FIG. 7, the change in the driving torque of the output shaft 33 according to the present embodiment shown by the solid line is smaller than that of the conventional one shown by the one-dot chain line, and the shift shock can be reduced.

In the above-described embodiment, open-loop control is employed. However, it is of course possible to correct the duty ratio of the hydraulic control solenoid valve 56 by feedback control or learning control.

For example, when performing feedback control, an operation as shown in FIG. 8 may be performed instead of steps S21 to S24 shown in FIG. That is, in S27, the ECU 38 detects the input shaft 19 of the gear transmission detected by the input shaft speed sensor 108.
Set the target rate of change for the rotation speed of. Next, S28
Based on the detection signal from the input shaft speed sensor 108,
Calculate the rate of change of the rotation speed of the input shaft 19 of the gear transmission,
The deviation between this and the target change rate is determined in S29, the duty ratio corresponding to this deviation is calculated in S30, and this corrected duty ratio is output to the hydraulic control solenoid valve 56 in S31. Then, in S32, the input shaft 19 of the gear transmission is detected by the input shaft speed sensor 108 and the vehicle speed sensor 109.
And based on the rotation speed of the output shaft 33, it is determined whether or not the synchronization of the second speed is completed in S33. If the synchronization of the second speed is not completed, the process returns to S28 again, and the rotation speed of the input shaft 19 is determined. The new correction duty ratio is repeatedly output to the hydraulic control solenoid valve 56 so that the change rate follows the target change rate.

Thus, the hydraulic pressure for the kick down servo 39 is applied to the input shaft of the gear transmission until the synchronization of the second speed is completed.
Increase at the rate corresponding to the target change rate of the rotation speed of 19,
After performing the second-speed synchronization, the process proceeds to step S25 shown in FIG.

If it is determined in S33 that the second-speed synchronization has not been completed, the process returns to step S27 instead of S28, and the input shaft 1 of the gear transmission detected by the input shaft speed sensor 108.
The target change rate for the rotation speed 9 may be reset. In this case, by setting the first target change rate to a relatively large value and setting the second and subsequent target change rates to gradually smaller values, there is an advantage that the time required to complete the second-speed synchronization can be reduced. .

In the above embodiments, the upshift from the 1st gear to the 2nd gear has been described. However, it goes without saying that the present invention can be applied to other upshifts during acceleration. .

<Effect of the Invention> According to the shift control device for an automatic transmission of the present invention, when a shift-up signal is output and it is determined that the vehicle is in an acceleration state, the rate of change in the rotation speed of the transmission input shaft is positive. , A signal for reducing the engine output is output when it is determined that it is immediately before the actual shift start timing, so that the engagement of the engagement-side frictional engagement element At the same time as the start, the output of the engine is reduced, the change in the torque of the transmission output shaft can be kept gradual, and the effect of preventing a sudden increase in the engine output and suppressing the occurrence of a shift shock is exhibited.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a mechanism of an automatic transmission according to an embodiment of the present invention, FIG. 2 is an operating element diagram of a friction engagement element thereof, and FIG. 3 is a hydraulic circuit of a hydraulic control device in the present embodiment. FIG. 4 is a conceptual diagram of a mechanism showing a part thereof, FIG. 4 is a conceptual diagram of control in this embodiment, FIG. 5 is a sectional view showing a schematic structure of a portion of the throttle device, FIG.
FIG. 7 is a graph showing the relationship between the number of rotations of the input shaft of the gear transmission, the rate of change in rotation thereof, and the state of change in the torque of the output shaft of the gear transmission during gear shifting, and FIG. It is a flowchart. Further, in the reference numerals in the drawing, 11 is an engine, 13 is a torque converter, 18
Is the transmission case, 19 is the input shaft, 20 is the front clutch,
21 is a rear clutch, 22 is a fourth speed clutch, 23 is a kick down brake, 24 is a low reverse brake, 33 is an output shaft,
34 is a kick down drum, 36 is an oil pump, 37 is a hydraulic control unit, 38 is an electronic control unit, 39 is a kick down servo, 46 and 47 are solenoid valves for shift control, 56 is a solenoid valve for hydraulic control, and 60 is intake Pipe, 65 is the intake passage, 66 is the throttle valve, 69
Is an accelerator lever, 70 is a throttle lever, 76 is an accelerator pedal, 85 is an actuator, 87 is a control rod, 88 is a pressure chamber, 91 is a connection pipe, 92 is a vacuum tank, 94 is a pipe,
95,100 are output control solenoid valves, 104 is fuel injection nozzle, 105
Is a fuel supply solenoid valve, 106 is a spark plug, 107 is a throttle opening sensor, 108 is an input shaft speed sensor, 109 is a vehicle speed sensor, and 111 is a K / D servo switch.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI F16H 59/48 F16H 59/48 (72) Inventor Katsutoshi Usuki 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Takeo Hiramatsu 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Toshitaka Naruse 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Automotive Industries, Ltd. (56) References JP-A-61-150837 (JP, A) JP-A-2-173464 (JP, A) JP-A-1-285428 (JP, A) JP-A-61-253229 (JP, A) JP-A-60-260749 (JP, A) JP-A-60-248445 (JP, A) Patent 2543402 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 41/00- 41/28 F02D 29/00-29/06 F02D 41/00-41/40 F16H 59/00-63/48

Claims (2)

(57) [Claims] 1. A plurality of frictional engagement elements provided between a transmission input shaft to which a driving force from an engine having output control means is input and a transmission output shaft to output the driving force to driving wheels. A shift control device for an automatic transmission, comprising: a shift control unit that switches a gear ratio by engaging or disengaging a clutch; and a hydraulic pressure supply unit that supplies a control oil pressure set to the friction engagement element. An acceleration state detecting means for judging an acceleration state of the vehicle; and a shift up signal is output by the shift control means.
When the acceleration state detecting means determines that the vehicle is in an accelerated state, the actual shift is determined immediately before the actual shift start timing at which the actual shift starts after the engagement-side friction engagement element starts engaging. And a power reduction means for outputting a signal for reducing the engine output to the output control means when it is determined by the detection means immediately before the start of the actual gear shift to determine immediately before the start time of the actual gear shift. The immediately preceding actual shift detecting means includes a rotational speed change rate detecting means for detecting a rotational speed change rate of the transmission input shaft, and the rotational speed change rate detected by the rotational speed change rate detecting means is positive. A shift control device for an automatic transmission, wherein the shift control device determines that the time immediately before the actual shift start timing is changed when the shift is within a range equal to or less than a predetermined value. 2. A shift control device for an automatic transmission according to claim 1, wherein said acceleration state detecting means has a rotation speed change rate detected by said rotation speed change rate detection means which is larger than said predetermined value. A shift control device for an automatic transmission, which determines that the vehicle is in an acceleration state when the speed is equal to or more than a predetermined value.