JPH0599322A - Speed change control device for automatic transmission - Google Patents

Abstract

PURPOSE:To perform control of resetting torque down by the proper timing. CONSTITUTION:A device has first sensor for detecting a rotational speed of the first rotary member 1 with the rotational speed increased in the case of the first speed change and decreased in the case of the second speed change and a second sensor 4 for detecting a rotational speed of the second rotary member 2 of decreasing its rotational speed in the case of the first speed change. A speed change end decision means 5, which decides end timing of the first speed change based on an output of the first sensor 3 and further the end timing of the first speed change based on an output of the second sensor 4 in the case of generating the second speed change before deciding the end timing of the first speed change, is provide. An input torque resetting means 6, which resets input torque by releasing reduction control of input torque of the first speed change based on deciding the end timing of the first speed change by this speed change end decision means 5, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling a shift in an automatic transmission for a vehicle, and more particularly to a shift control device which also controls input torque during a shift.

[0002]

As is well known, in automatic transmissions for vehicles,
The gear shift is executed by changing the engagement / disengagement state of the friction engagement device such as a clutch or a brake, but if the engagement / disengagement timing of the friction engagement device involved in the gear shift is inappropriate, The output shaft torque fluctuates greatly and the gear shift shock worsens, or the friction engagement device slides excessively to reduce its durability, or the gear shift time increases and the gear shift feeling deteriorates. .. Therefore, conventionally, an accumulator is arranged in the oil passage that supplies oil pressure to the friction engagement device, and the back pressure is controlled,
Alternatively, the timing of engagement / disengagement of the friction engagement device is optimized by means such as switching the orifice, and further, the engine torque is reduced during gear shifting to reduce the torque applied to the friction engagement device performing the switching operation. As a result, the operation timing is optimized.

If the input torque to the automatic transmission is reduced by lowering the engine torque or the like, the output torque is also reduced.
It is preferable that the input torque reduction control (torque down control) be accurately limited during the shift, and therefore, it is preferable that the input torque be restored to the original torque without largely deviating from the end of the shift. That is, since the torque down control needs to be performed in synchronization with the shift, it is sufficient to control the return of the torque according to the end of the shift.
Therefore, for example, in the invention disclosed in Japanese Patent Laid-Open No. 56-35857, the determination of the end of gear shift and the control of torque recovery are performed based on the turbine speed. However, depending on the configuration of the gear train, it may not be possible to directly detect the turbine speed or the speed of the input shaft connected to the turbine due to space limitations, and therefore, for example, Japanese Patent Laid-Open No. 63-17130. In the invention described in (1), the torque recovery control is performed according to the rotational speed of the clutch that connects the input shaft and the auxiliary transmission unit that is the transmission unit for overdrive.

Further, conventionally, a timer (guard timer) has also been used to complement the failure of sensors, and in the invention disclosed in Japanese Patent Laid-Open No. 61-129341, the guard timer is set. The torque recovery control is performed as time passes.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Since the clutch of the sub-transmission unit described in Japanese Patent No. 7130 has a high frequency of being engaged and rotating together with the input shaft, generally, the end of the shift and the timing of torque recovery are determined based on the rotational speed of the clutch. You can However, for example, in the one disclosed in Japanese Patent Application Laid-Open No. 64-15560, which shifts the main transmission portion and the sub-transmission portion simultaneously or together, the clutch is disengaged at the second speed to rotate the clutch drum. Because it can be stopped
When a so-called multiple shift in which the shift from the third speed to the second speed is performed following the shift from the fourth speed to the third speed, the rotation speed of the clutch drum whose rotation speed is to be detected is the rotation speed at the third speed. Therefore, the rotational speed of the clutch does not reach the rotational speed of the third speed that determines the end of gear shift and the timing of torque recovery, and the torque down control is continued. In such a case, the timing for controlling the torque recovery is determined by the guard timer described above, but the original purpose is to complement the fact that the guard timer cannot control the output from various sensors. Therefore, the set time is generally set to a length to start the control after the timing of control by the output of the sensor.Therefore, if the judgment of torque recovery is made by the guard timer, the delay of torque recovery is delayed. This causes a disadvantage that the shift feeling is deteriorated.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a shift control device for an automatic transmission capable of terminating the torque down control at the time of shifting, that is, controlling the torque restoration at appropriate timing. It is intended.

[0007]

The present invention achieves the above object by being configured as shown in FIG. That is, the present invention increases the number of revolutions during the first shift from the first shift stage to the second shift stage and during the second shift from the second shift stage to the third shift stage. An automatic transmission having a first rotating member 1 whose rotational speed is reduced and a second rotating member 2 whose rotational speed is reduced during the first gear shift, and which controls input torque reduction during gear shifting. In the shift control device of A, a first sensor 3 for detecting the rotation speed of the first rotating member 1, a second sensor 4 for detecting the rotation speed of the second rotating member 2, and the first shift Is determined based on the output of the first sensor 3, and when the second gear shift occurs before the end of the first gear shift is determined, the end of the second gear shift is determined based on the output of the second sensor 4. The end-of-shift determination means 5 for determining the end of the first shift and the end-of-shift determination means 5 for the end of the first shift And it is characterized in that it comprises an input torque returning means 6 which releases the reduction control of the input torque of the first shift based on the determined returning the input torque.

[0008]

In the automatic transmission A of the present invention, the second rotary member 1 is used during the first shift from the first shift stage to the second shift stage.
The number of rotations of the second rotating member 2 increases, and the number of rotations of the second rotating member 2 decreases. Further, at the time of the second shift from the second shift stage to the third shift stage, the rotation speed of the first rotating member 1 decreases.
Then, control for reducing the input torque is performed at least in the first shift. The rotation speeds of the first rotating member 1 and the second rotating member 2 are respectively detected by the first sensor 3 or the second sensor 4, and when the first gear shift occurs, the first When the rotation speed of the rotary member 1 increases and the output of the first sensor 3 reaches a predetermined value, the gear shift end determination means 5 determines that the end of the first gear shift has been reached. If the second gear shift from the second gear stage to the third gear stage starts after the first gear shift occurs and before the gear shift end determination means 5 determines the end of the first gear shift, The end determination unit 5 determines the end of the first shift based on the output of the second sensor 4. Then, when the shift end determination unit 5 determines the end of the first shift, the input torque restoring unit 6 releases the input torque reduction control to restore the input torque.

[0009]

1 is a block diagram showing an embodiment of the present invention, in which an automatic transmission A connected to an engine E has a transmission mechanism. As a torque converter 21 having a lock-up clutch 20, a second speed change unit 30 having a set of planetary gear mechanisms, and a first speed change unit 40 for setting a plurality of forward speeds and reverse speeds by two sets of planetary gear mechanisms. And are provided.

The second transmission section 30 is for performing two-stage switching between high (H) and low (L), and the carrier 31 of the planetary gear mechanism is connected to the turbine runner 22 of the torque converter 21. And also this carrier 31
Between the sun gear 32 and the sun gear 32, a clutch Co and a one-way clutch Fo are provided in parallel with each other, and a brake B is provided between the sun gear 32 and the housing Hu.
o is provided.

The sun gears 41, 42 in each planetary gear mechanism of the first transmission unit 40 are provided on a common sun gear shaft 43, and in the planetary gear mechanism on the left side (front side) of the first transmission unit 40 in the drawing. Ring gear 44 and second
A first clutch C1 is provided between the gear unit 30 and the ring gear 33, and a second clutch C2 is provided between the sun gear shaft 43 and the ring gear 33 of the second gear unit 30. The carrier 45 of the planetary gear mechanism on the left side of the drawing and the ring gear 46 of the planetary gear mechanism on the right side (rear side) of the first transmission unit 40 are integrally connected, and
The output shaft 47 is attached to the carrier 45 and the ring gear 46.
Are connected.

The first brake B1 which is a band brake is provided on the outer peripheral side of the clutch drum of the second clutch C2 so as to stop the rotation of the sun gear shaft 43, more specifically, the sun gear shaft 43 and the housing. A first one-way clutch F1 and a second brake B2 are arranged in series with Hu, and a second one-way clutch F2 with a carrier 48 and a housing Hu in the planetary gear mechanism on the rear side. The third brake B3 is arranged in parallel.

A hydraulic circuit 50 for supplying and discharging hydraulic pressure to and from the clutches Co, C1, C2 and the brakes Bo, B1, B2, B3 is provided. This hydraulic circuit 50
Is a first to a third solenoid valve S1, S2, S3 for executing the first to fifth speed shifts, and an ON / OFF (engagement / release) of the lockup clutch 20. A lock-up solenoid valve SL and a back pressure solenoid valve SN for controlling the back pressure of an accumulator (not shown) are provided.

These solenoid valves S1, S2, S
An electronic control unit (ECU) 51 is provided for controlling 3, SL, SN and for controlling engine torque. This electronic control unit 51 is mainly composed of a central processing element, a memory element and an input / output interface, and each solenoid valve S1, S2, S3, SL,
As data for controlling SN and engine E, a vehicle speed signal detected by a vehicle speed sensor 52, a throttle opening signal detected by a throttle opening sensor 53 attached to the engine E, a shift output from a shift lever position sensor 54. Position signal, shift pattern selection switch 55 for power mode, economy mode, etc.
Pattern select signal output from the water temperature sensor 5
6, the engine water temperature signal detected, the brake signal output from the foot brake switch 57 and the side brake switch 58, the signal from the Co sensor 59 that detects the rotational speed Nco of the clutch Co of the second speed change unit 30, the first speed change C2 for detecting the rotational speed Nc2 of the second clutch C2 of the section 40
A signal or the like from the sensor 60 is input.

FIG. 3 shows the clutches Co, C1, C2 and the brakes Bo, B1, B2, in the above automatic transmission A.
In the engagement operation table of B3, ○ marks are engaged, blank columns are released,
The mark Δ indicates engagement during engine braking.

The electronic control unit 51 determines the shift stage to be set mainly based on the shift map and the vehicle speed and the throttle opening according to the shift pattern selected by the shift pattern selection switch 55, and the determination is made. Based on the result, the solenoid valves S1, S2, S3 are appropriately turned on / off to set the respective shift stages shown in FIG.
Then, at the time of shifting, a signal is output from the electronic control unit 51 to the engine E, and torque reduction control is performed. Specifically, this is performed by delaying the ignition timing of the engine E or reducing the fuel injection amount. The determination as to whether to end the engine torque reduction control (torque down control) (torque return control) is normally made based on the output of the Co sensor 59, but the rotation speed of the clutch Co in the second speed change section 30 is determined. When a so-called multiple shift occurs in which the torque is reversed from the increase to the decrease, the torque return control is determined based on the output of the C2 sensor 60.

FIG. 4 is a flowchart showing a torque control routine in the case of downshifting from the fourth speed to the third speed and downshifting from the third speed to the second speed.
In step 1, it is judged whether or not the signal for instructing the shift from the third speed to the third speed is output. If the result of the judgment is "no", then the control routine is exited, and "yes".
If so, it proceeds to step 2 and determines whether or not to perform the torque down control at the time of downshifting from the fourth speed to the third speed. As an example, this is performed depending on whether or not the rotational speed Nco of the clutch Co satisfies the following equation.

Nco ≧ No × i−α1 where No is the number of revolutions of the output shaft 47, i is the gear ratio at the third speed, and α1 is a constant. That is, in the downshift from the fourth speed to the third speed, as shown in the operation table of FIG. 3, the first speed change unit 40 is changed from the third speed to the third speed while the second speed change unit 30 is kept low (L). Since the shift is executed in two stages, the rotational speed Nco of the clutch Co tries to increase to a rotational speed of a value obtained by multiplying the rotational speed No of the output shaft 47 by the speed change ratio i in the third speed. Therefore, step 2 is a process for determining the time point at which the engine speed reaches a speed lower by a predetermined constant α1 than the time point at which the engine speed reaches the third speed, that is, the time point in synchronization with the third speed. The control process is continued until it becomes "Yes", and when the judgment result becomes "Yes", the torque down control at the time of downshifting from the fourth speed to the third speed is started (step 3). As described above, this is performed by delaying the ignition timing of the engine E or reducing the fuel injection amount based on the output signal from the electronic control unit 51. At the same time, a timer (guard timer) T is started to count time (step 4). Furthermore, in step 5, the third
It is determined whether or not the speed is synchronized. As an example, this is performed depending on whether or not the rotational speed Nco of the clutch Co satisfies the following equation.

Nco ≧ No × i−α2 where α2 is a constant and is a value smaller than the above-mentioned constant α1. That is, the determination in step 5 is made by determining whether or not the rotational speed Nco of the clutch Co is extremely close to the rotational speed at the third speed. If the determination result is "yes", the process proceeds to step 6 and torque recovery control is performed. This is performed, for example, by returning the advance value of the ignition timing or increasing the fuel injection amount to the original amount. The above-described synchronization determination with the third speed is performed by detecting the rotation speed of the clutch Co. However, since the rotation speed is a high rotation speed, the synchronization determination and the torque recovery control associated therewith are performed at accurate timing. be able to.

On the other hand, if the decision result in step 5 is "NO", that is, if the downshift to the third speed is in progress,
It is determined whether or not the count value of the timer T has reached a predetermined value T0 (step 7). This timer T is a guard timer and serves as a backup when the synchronization judgment cannot be made due to a sensor failure or the like. Therefore, the set value T0 is sufficiently longer than the time required to complete the shift. If it is time, and if the result of the determination is "yes", then the process proceeds to step 6 and torque recovery control is performed.

If the result of the determination made in step 7 by the timer T is "no", the process proceeds to step 8 and it is determined whether or not a downshift command signal from the third speed to the second speed is output. If the result of the determination is “No”, the downshift from the fourth speed to the third speed will be continued,
The control process returns to step 5. If the result of the determination in step 8 is "yes", the process proceeds to step 9 and the third
It is determined whether or not the downshift from the second speed to the second speed has started. In the second speed, as shown in the operation table of FIG. 3, the clutch Co of the second speed changer 30 is released and the brake Bo is released.
Therefore, when the shift from the third speed to the second speed is started, the rotational speed of the clutch Co starts to decrease. Therefore, the determination in step 9 can be made when the rotational speed of the clutch Co detected this time is lower than the rotational speed of the clutch Co detected previously, and the difference exceeds a predetermined value. Further, in the third speed, the entire second transmission portion 30 rotates integrally, and the ring gear 33 and the sun gear 32 have the same rotational speed, but in the second speed, the clutch C is used.
By releasing o and engaging the brake Bo, the rotation speed of the sun gear 32 becomes lower than the rotation speed of the ring gear 33. Therefore, the rotation speed of the second clutch C2 detected by the C2 sensor 60 and the rotation speed of the output shaft 47. The number of revolutions of the first clutch C1, that is, the number of revolutions of the ring gear 33 is obtained based on the number No and the value is compared with the number of revolutions Nco of the clutch Co detected by the Co sensor 59 to make the determination in step 9. You can also This step 9
If the result of the determination is “No”, the downshift command signal from the third speed to the second speed is output, but the second speed is still in the second speed.
Since there is no downshift to speed,
If the result of the determination in step 9 is "yes", the process proceeds to step 10 and the second clutch C2 is detected by the C2 sensor 60 (that is, the rotation speed of the sun gear shaft 43) Nc2 based on the rotation speed. Determines synchronization to 3rd speed. In the third speed state, the rotation of the second clutch C2 (that is, the sun gear shaft 43) is stopped by the second brake B2. Therefore, the determination result of step 10 is that the rotation speed Nc2 detected by the C2 sensor 60 is a predetermined small value. This can be done by determining whether or not β has become less than or equal to (Nc2 ≦ β?). If the determination result is "no", the process returns to step 5, and if "yes", it means that the shift from the fourth speed to the third speed is completed, so the process proceeds to step 6 and the torque return control is performed. To do.

The clutch Co, the second clutch C2, and the rotational speed Nco of the output shaft 47 during the above-described gear shift,
The changes in Nc2 and No, changes in engine torque, and changes in output shaft torque are shown in a time chart of FIG. That is, with the output of the downshift command signal from the 4th speed to the 3rd speed, the inertia phase of this downshift starts at time t1, the rotational speed Nco of the clutch Co gradually increases, and the rotational speed of the second clutch C2 increases. Nc2 gradually decreases. The output shaft torque also begins to drop. The torque down control is started at time t2 when the rotational speed Nco of the clutch Co becomes lower than the value obtained by multiplying the output shaft rotational speed No by the speed ratio i of the third speed by a predetermined constant α1.
If the downshift to third speed continues,
The rotation speed Nco of the clutch Co increases as shown by the alternate long and short dash line, and a synchronization judgment is made at the time t3 when the rotation speed reaches a rotation speed lower by a constant α2 than the synchronization rotation speed (No × i) of the third speed and the torque recovery control is performed. The engine torque gradually returns to the original torque as shown by the alternate long and short dash line.

On the other hand, when the shift from the third speed to the second speed is started at a time point t4 prior to the time point t3 when the determination of the synchronization with the third speed is made, the rotational speed Nco of the clutch Co decreases from that time point. Therefore, depending on this rotation speed Nco, the synchronization with the third speed cannot be determined, and the torque recovery control cannot be performed. In this case, the rotation speed Nc2 of the second clutch C2
Is adopted as the judgment data of the torque return control, and the synchronization to the third speed is judged at time t5 when the value becomes equal to or smaller than a predetermined small value β, and the torque return control is performed accordingly. In addition, since the gear is changed to the second speed,
The rotation speed Nc2 of the clutch C2 increases in the reverse rotation direction. In FIG. 5, the absolute value is shown.

In FIG. 5, each change in the case of performing the torque return control by the guard timer is shown by a broken line. As described above, the time set by the guard timer is sufficiently longer than the time required for shifting, so torque recovery control will be performed at time t6, which is significantly delayed from the time t5.
As a result, there is a time delay in the change of the rotation speed Nc2 of the second clutch C2 and the increase of the output shaft torque, which causes a so-called rattling feeling, which deteriorates the shift feeling. On the other hand, in the control shown in FIG. 4, the second clutch C2 detected by the C2 sensor 60 instead of the output of the Co sensor 59 is detected.
Since the synchronization determination to the third speed and the torque recovery control associated therewith are performed based on the rotation speed Nc2, the engine torque recovery timing is appropriate and the shift feeling is maintained well.

The present invention is not limited to the above embodiment, and the present invention may be configured to reduce the input torque of the automatic transmission by means other than reducing the engine torque. The present invention can be applied to a shift control device for an automatic transmission having a gear train other than the gear train shown in FIG. 2, and can also be applied to a gear shift other than the fourth gear shift to the third gear shift.

[0026]

As is apparent from the above description, according to the shift control device of the present invention, the end of the shift is determined based on the rotation speed of the first rotating member having a high rotation speed,
If a shift occurs in which the rotational speed of the rotating member decreases during the shift, the final speed of the shift is changed based on the rotational speed of the second rotating member in which the rotational speed also changes during the shift. Since the determination is made, the end of the shift can be accurately determined, and accordingly, the torque recovery control can be performed at an appropriate timing. Therefore, according to the present invention, the shift with good shift feeling is performed. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a block diagram schematically showing an embodiment of the present invention.

FIG. 3 is an operation table thereof.

FIG. 4 is a flowchart showing a torque control routine during gear shifting.

FIG. 5 is a time chart showing changes in the rotational speed, engine torque, and output shaft torque of the clutch of the second speed change unit and the second clutch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st rotating member 2 2nd rotating member 3 1st sensor 4 2nd sensor 5 End-of-shift determination means 6 Input torque return means

Claims (1)

[Claims] 1. A first gear from a first gear to a second gear
The number of revolutions increases during the shifting of the
And a second rotating member whose rotation speed decreases during the second gear shift to the second gear, and a second rotary member whose rotation speed decreases during the first gear shift. In a shift control device for an automatic transmission that performs torque reduction control, a first sensor that detects a rotation speed of the first rotating member, a second sensor that detects a rotation speed of the second rotating member, and The end of the first shift is determined based on the output of the first sensor, and based on the output of the second sensor when the second shift occurs before the end of the first shift is determined. And a shift end determination means for determining the end of the first shift, and based on this shift end determination means for determining the end of the first shift, release the input torque reduction control of the first shift and input. It is specially equipped with input torque recovery means for recovering torque. A gear shift control device for an automatic transmission.