JPH0599304A - Speed change control device for automatic transmission - Google Patents

Abstract

PURPOSE:To more properly set the initial oil pressure in a release side, so that a speed change of small shock can be always executed, by learning- correcting the initial oil pressure of a shift in the release side of a magnetic field based on a rotational speed of a rotary member before starting feedback control, after starting the shift in the release side. CONSTITUTION:A central processing unit 104 inputs a signal of a C2 sensor 120 for detecting a drum rotational speed (speed change progress condition of the first transmission part 60) Nc2 of a clutch C2 and a signal of a C0 sensor 121 for detecting a drum rotational speed (speed change progress condition of the second transmission part 40) Nc0 of a clutch C0. Before changing a tilt of Nc0 by feedback control after starting a low gear shift, Nc0s (first rotational speed) is monitored to obtain a difference alphaNc0s between this first rotational speed and a target value Ncos at this time, and a logic for judging and correcting a high/low value of initial duty ratio DS by a level of this difference is added.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission having first and second transmission parts that can be independently shifted.

[0002]

2. Description of the Related Art Conventionally, first and second independently shiftable
An automatic transmission including a transmission unit is known. In such an automatic transmission, for example, a high gear shift of the first transmission unit is achieved by engagement, and a low gear shift of the second transmission unit is achieved by release, so that an upshift is performed as a whole. I have something to do.

In this case, when the shift commands for the respective transmission units are issued at the same time, the engagement takes longer than the release, so that the low gear shift of the second transmission unit is first started. This means that the shift is started from the low gear shift in the opposite direction even though the automatic transmission is about to be upshifted, and the shift is very uncomfortable.

Therefore, in order to eliminate such a problem in the related art, the start of the actual high gear shift of the engaged first transmission portion is detected, and after the detection, the second shift gear is released. A technique for issuing a shift command for a machine part has been proposed (for example, Japanese Patent Laid-Open No. 61-99745).

Further, when the end of the low gear shift of the second transmission unit comes after the end of the high gear shift of the first transmission unit, the automatic transmission as a whole is going to upshift, but A low gear shift (downshift) will remain at the end of the upshift, which is also a very unnatural shift.

Therefore, in order to eliminate such a problem in the related art, feedback control is performed on either or both of the engagement side and the disengagement side hydraulic pressure so that the low gear shift always ends before the high gear shift. Japanese Patent Application Laid-Open No. 64-1 has proposed a technique for optimizing a shift.
5560).

According to this method, even if the low gear shift starts early because the initial hydraulic pressure for starting the shift of the second transmission unit is too low, the progress of the low gear shift can be delayed by the feedback control. Conversely, even when the initial hydraulic pressure is too high and the low gear shift starts with a delay, the progress of the low gear shift can be accelerated by the feedback control, and the shift can be optimized.

[0008]

However, if the initial hydraulic pressure on the disengagement side deviates too much from the proper value, the disengagement is rapidly performed until the correction by the feedback control catches up due to the response delay of the hydraulic pressure, for example. The problem of being broken occurs. In addition, if the deviation of the initial hydraulic pressure is larger than the correction range of the feedback control, the problem that the correction cannot be completed until the end may occur at an extreme time.

The present invention has been made in view of such conventional problems, and in optimizing the shift,
This is to solve the above problem by setting the initial hydraulic pressure on the opening side, which is one of the most important factors, more appropriately so that gear shifting with a small shock can always be executed.

[0010]

SUMMARY OF THE INVENTION The present invention is provided with first and second transmission sections that can be independently shifted in series, and shifts one transmission section by engagement of a friction engagement device.
In a gear shift control device for an automatic transmission that shifts the other transmission unit by releasing a friction engagement device to realize gear shifting in the direction of engagement as a whole, the end of the shift on the release side is the engagement side. Means for feedback controlling the shift on at least one of the disengagement side and the engagement side so as not to occur after the end of the shift, and the first rotational speed of the rotary member after the start of the shift on the disengagement side and before the execution of the feedback control. To detect the second rotational speed of the rotary member after the end of the disengagement side shift, and to learn and correct the initial hydraulic pressure for the next disengagement side shift based on the first and second rotational speeds. Means for solving the above problems are provided.

[0011]

In the present invention, in order to optimally determine the initial hydraulic pressure on the releasing side, a method of learning the initial hydraulic pressure at the next shift based on the state of the shift actually executed this time is adopted. I chose More specifically, this learning monitors the remaining shift on the engagement side at the end of disengagement from the rotational speed of the rotating member, and if the remainder on the engagement side is large, it means that the disengagement is too fast. If the remaining amount on the engagement side is small, it is judged that the release is too late, and the initial hydraulic pressure is corrected so as to decrease.

By the way, when this learning is actually executed, one problem occurs as a real problem. As described above, because feedback control is performed, for example, even if the initial hydraulic pressure on the disengagement side is low and the shift on the disengagement side would end earlier than usual, the feedback control is performed. Since the correction is performed by the control so as to delay the progress of the shift on the disengagement side, the remaining amount on the engagement side is always the same at the end of the shift on the disengagement side, and even its qualitative tendency is not necessarily the initial hydraulic pressure. The point is that it may not match the height of.

In the present invention, in consideration of this point, the first rotational speed of the rotary member after the start of the shift on the disengagement side and before the execution of the feedback control and the disengagement are set as the base parameters for the learning correction. Both the second rotation speed of the rotating member at the end of the side shift is taken into consideration. As a result, both the state before the feedback control is executed and the state after the feedback control are executed can be reflected in the learning correction, and the learning can be performed with extremely high accuracy.

The rotating member for detecting the first rotation speed does not necessarily have to be the same as the rotating member for detecting the second rotation speed.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 shows an overall outline of an automatic transmission for a vehicle to which this embodiment is applied.

This automatic transmission has a torque converter 20 as its transmission portion and a second transmission portion 40.
And a first transmission unit 60 having three forward gears and one reverse gear.

The torque converter 20 includes a pump 2
1, a turbine 22, a stator 23, and a lockup clutch 24. The pump 21 is connected to the crankshaft 10 of the engine 1, and the turbine 22 is connected to the second transmission unit 4
0 is connected to the carrier 41 of the planetary gear set.

In the second transmission section 40, a planetary pinion 42 rotatably supported by the carrier 41 meshes with a sun gear 43 and a ring gear 44. In addition, between the sun gear 43 and the carrier 41,
A clutch C ₀ and a one-way clutch F ₀ are provided, and a brake B ₀ is provided between the sun gear 43 and the housing Hu.

The first transmission section 60 is provided with two rows of front and rear sides as a planetary gear unit.
This planetary gear device has a common sun gear 61, ring gears 62 and 63, planetary pinions 64 and 65, respectively.
And carriers 66 and 67.

The ring gear 44 of the second transmission section 40 is connected to the ring gear 62 via a clutch C ₁ . A clutch C ₂ is provided between the ring gear 44 and the sun gear 61. Further, the carrier 6
6 is connected to the ring gear 63, and the carrier 66 and the ring gear 63 are connected to the output shaft 70.

On the other hand, the carrier 67 and the housing Hu
A brake B ₃ and a one-way clutch F ₂ are provided between the sun gear 61 and the housing Hu, and a brake B ₂ is provided between the sun gear 61 and the housing Hu via the one-way clutch F ₁ . A brake B ₁ is provided between the sun gear 61 and the housing Hu.

This automatic transmission is provided with the transmission section as described above, and the throttle sensor 10 for detecting the throttle opening which reflects the load state of the engine 1.
0, and a central processing unit (ECU) 104 to which signals from the vehicle speed sensor 102 for detecting the vehicle speed are input, electromagnetic solenoid valves S _{1 to} S ₄ in the hydraulic control circuit 106, and electromagnetic proportionality according to a preset shift pattern. Valve SLu
, And SLn are driven and controlled, and as shown in FIG. 3, engagement of respective clutches, brakes and the like is combined to perform gear shift control.

In FIG. 3, a circle mark indicates that the clutch or the brake is engaged, and a circle mark indicates that the brake is engaged in order to activate the engine brake when the engine is driven from the wheel side. Which indicates that.

The electromagnetic solenoid valves S ₁ and S ₂ are
As shown in FIG. 4, the first and second shift valves that control the first to third speed states of the first transmission unit 60 are controlled, and the electromagnetic solenoid valve S ₃ is controlled to the second speed state. The third shift valve that switches between the high speed side and the low speed side of the transmission unit 40 is controlled, and the electromagnetic solenoid valve S ₄ controls the lockup clutch 24 of the torque converter 20.

The solenoid proportional valve SLu is the central processing unit 1
According to the magnitude of the load current controlled by 04, an excessive engagement pressure (drain pressure) of the brake B ₀ is adjusted and controlled together with a B ₀ control valve (not shown). The solenoid proportional valve SLn can adjust and control the transient engagement pressure of the brake B ₂ together with an accumulator (not shown) capable of controlling the back pressure. In addition, each solenoid proportional valve SLu,
Since the hardware structure of SLn engagement pressure adjustment / control itself is the same as the conventional one, its description is omitted.

As is apparent from FIG. 3 described above, in the automatic transmission according to this embodiment, for example, shifting from the second speed stage to the third speed stage is performed by the brake B ₂ of the first transmission section 60. And the reverse shift in the second transmission unit 40 by releasing the brake B ₀ of the second transmission unit 40.

Therefore, if the synchronous control is not properly executed, the shift shock may increase. Therefore, the solenoid proportional valves SLu and SLn are used to engage the brake B ₂ of the first transmission unit 60 and release the brake B ₀ of the second transmission unit 40 during the shift from the second speed stage to the third speed stage. Control of.

In FIG. 2, reference numeral 110 is a shift position sensor, which is operated by a driver to operate N, D,
R is for detecting the position, 112 is a pattern select switch for selecting E (economical traveling), P (power traveling), etc. Further, 114 is a water temperature sensor for detecting the engine cooling water temperature. Reference numeral 116 denotes a foot brake, and 118 denotes a brake switch for detecting the operation of the side brake.

Here, in this embodiment, as shown in FIGS. 2 and 4, in addition to these input signals to the central processing unit 104, the drum rotation speed of the clutch C ₂ (first transmission unit 60). Of the C ₀ sensor 121 for detecting the signal of the C ₂ sensor 120 for detecting N _c2 and the drum rotation speed of the clutch C ₀ (the gear changing state of the second transmission unit 40) N _c0 . The signal is also input.

FIG. 5 is a time chart when the upshift from the second speed stage to the third speed stage is executed in the apparatus of the above embodiment.

[0032] P _b0 in Fig. 5 is a hydraulic action of the brake B ₀ to release, as described above, the current value to the electromagnetic proportional valve SLu (duty ratio) by DSLU, can control that level. Increasing the current value DSLU, acting hydraulic P _b0 reduced pressure, P _b0 is boosted by lowering.

The shift sequence is as follows.

First, P _b0 is changed to D by the shift command (t ₁ ).
slu = Ds (duty ratio corresponding to initial hydraulic pressure: hereinafter simply referred to as initial duty ratio) is maintained at a level, while
At the same time, the hydraulic pressure supply to the brake B ₂ is started. The hydraulic phase supply to the brake B ₂ starts the inertia phase of the high gear shift of the first transmission unit 60 (substantial shift period in which the rotation speed of the rotating member changes) (t ₂ ), and the first transmission unit 60 C2 which is one of the rotating members of
The rotation speed N _{c2 of the motor} starts changing. First by this change
When the start of the inertia phase of the transmission is detected (
t ₃ ), the value of Dslu is gradually increased from the initial duty ratio Ds, and the working oil pressure P _b0 of the brake B ₀ is gradually reduced from the initial oil pressure P _b0s .

As a result, the low gear shift of the second transmission unit 40 is started (t ₄ ), and the rotation speed N _c0 of the clutch C ₀ which is one of the rotating members of the second transmission unit 40 starts to change. When the start of the low gear shift is detected by the change of N _c0 (t ₅ ), the gradual increase of Dslu is finished, and this time, the target value N _c0 °, N of the rotation change starting from N _c0 and N _c2 at that time is started. _c2 ° is set for each N _c0, N _c2, real N _c0, N _c2 is P _b0, P _b2 is controlled along these (feedback control).

Eventually, N _c1 (= ih × N ₀ + ρ × N _c2 ) -N will be the time when the low gear shift of the second transmission unit 40 is completed.
It is detected by monitoring that _c0 becomes equal to or less than a predetermined value (t ₆ ), N _c2e at this time is monitored, and the initial duty ratio Ds of the next shift is changed depending on this value (second rotation speed). Learning control based on N _c2e ).

Here, consider a case where the level of the initial duty ratio Ds is too high (when the initial oil pressure P _b0s is too low). If there is no feedback control, the rotation changes as shown by the broken line and N at the end of the low gear shift
_{Since c2e} should have become large, the correction amount for the next determination of the initial duty ratio Ds must also become large accordingly.

Actually, however, N _c0 and N _c2 changes as shown by the solid line due to the effect of the feedback control, and N _c2e at the end point t ₆ of the low gear shift is small, so the correction amount of the initial duty ratio Ds is also small. Get smaller. For this reason,
There is a possibility that the learning speed of the initial duty ratio Ds will decrease or that no learning will be performed in some cases. When the initial duty ratio Ds is high (the initial hydraulic pressure _Pb0s is low), the low gear shift progress speed immediately after the start of the low gear shift causes a large drop in the output shaft torque, which is not preferable in terms of shift shock.

As described above, the reason why N _c2e does not match the appropriate learning amount at the end time t _{6 is} that the initial duty ratio Ds is low as long as the feedback control is executed (the initial hydraulic pressure P
_{If b0s} is high), the same happens.

Therefore, in this embodiment, N _c0s (first rotation speed) is monitored after the low gear shift is started and before the inclination of N _c0 is changed by the feedback control, and this and the target value N at this time are monitored. _Find the difference αN _c0s from _c0s °,
A logic for determining / correcting whether the initial duty ratio Ds is high or low depending on the size is added (learning control based on the first rotation speed N _c0s ).

This control flow is shown in FIG.

That is, first, at step 302, it is judged if the rotational speed (second rotational speed) N _c2e of the clutch C ₂ at the end of the low gear shift is within a predetermined value A 1 -A 2. If the second rotation speed N _c2e is not within this range, the feedback control also causes the high gear shift to remain above the appropriate remaining amount at the end of the low gear shift, or to remain below the appropriate remaining amount. Since it has not been done, it is considered that this qualitative tendency is consistent with the level of the initial duty ratio Ds. Therefore, in this case, step 30
4, the learning correction is performed (reasonably large) based on the second rotation speed N _c2e .

On the other hand, the second rotation speed N _c2e is the predetermined value A1 −
If it is within A2, the second rotation speed N _c2e
As far as I see, it is considered that the feedback control worked well, so the relationship between the second rotation speed N _c2e and the amount to be learned may not necessarily match. Therefore, in this case, the learning control based on the first rotation speed N _c0s is performed.

In the learning control based on the first rotation speed N _c0s , as shown in FIG. 7, is the difference between the first rotation speed N _c0s and the target value N _c0s at that time within the range of B1-B2? The initial duty ratio Ds is learned and controlled based on the result depending on whether or not there is a case. That is, when N _c0s −N _c0s ° is smaller than the predetermined value B1, it means that the progress of the low gear shift of the second speed change base portion is too slow.
In step 08, learning correction is performed to increase the initial duty ratio Ds in order to lower the initial hydraulic pressure _Pb0s . On the other hand, when _{Nc0s- Nc0s} ° is larger than the predetermined value B2, the low gear shift progresses too fast, so the _routine proceeds from step 310 to step 312 to increase the initial oil pressure _Pb0s and the initial duty ratio Ds decreases. Corrected. As a result, the second rotation speed N _c2e is within the predetermined value A 1 -A 2, and the difference between the second rotation speed N _c0s and the target value N _{c0 s} ° at that time is between the predetermined value B 1 -B 2. The initial duty ratio Ds is unchanged only when the value is within the range. It should be _noted that this B2 may be set lower than N _c0s °.

In this embodiment, the learning control based on the specifications before the feedback is executed is used in addition to the learning control based on the specifications after the feedback is actually executed. It becomes possible to reasonably and accurately perform the learning correction in consideration of the correction ability in the feedback control.

[0046]

As described above, according to the present invention, the learning correction of the initial hydraulic pressure can be optimally executed even though the feedback control is executed, so that the shock is more stable and the shock is small. It is possible to obtain an excellent effect that the gear shift can be executed.

[Brief description of drawings]

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

FIG. 2 is an overall skeleton diagram of an automatic transmission for a vehicle to which an embodiment of the present invention is applied.

FIG. 3 is a diagram showing an engagement state of each friction engagement device of the embodiment apparatus.

FIG. 4 is a diagram showing an input / output relationship between a central processing unit and a hydraulic control device.

FIG. 5 is a diagram showing a shift characteristic realized by the apparatus of the embodiment.

FIG. 6 is a flowchart showing a control flow executed in the apparatus of the above embodiment.

FIG. 7 is a diagram showing a relationship between N _c0 and N _c0 °.

[Explanation of symbols]

40 ... second transmission unit, 60 ... first transmission unit, 104 ... CPU, 106 ... hydraulic control unit, B ₂ ... (brake engaged in the first transmission unit) brake, B ₀ ... Brake (Brake released in the second transmission unit), SLu ... Electromagnetic proportional valve for adjusting working hydraulic pressure (drain pressure) of brake B ₀ , SLn ... Electromagnetic proportional for adjusting working hydraulic pressure (engagement pressure) of brake B ₂ valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidehiro Ohba 1st Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Akira Suzuki 10th Takane Fujii Town, Aichi Prefecture Aisin A / D Abri Within the corporation

Claims (1)

[Claims] 1. A first transmission section and a second transmission section which are independently shiftable are provided in series, one transmission section is shifted by engagement of a friction engagement device, and the other transmission section is frictionally engaged. In a shift control device for an automatic transmission that shifts by releasing the coupling device and realizes a shift in the direction of engagement as a whole, the end of the shift on the release side does not end after the end of the shift on the engagement side. A means for feedback-controlling the shift on at least one of the disengagement side and the engagement side; means for detecting the first rotation speed of the rotating member after the start of the shift on the disengagement side and before the execution of the feedback control; Means for detecting the second rotation speed of the rotating member after the completion of the shift, and means for learning and correcting the initial hydraulic pressure for the next release-side shift based on the first and second rotation speeds. Shift control device for an automatic transmission, characterized in that the.