JPH05312259A - Speed change controller for automatic transmission - Google Patents

Abstract

PURPOSE:To provide a speed change controller of an automatic transmission for detecting output shaft torque in the speed change to control oil pressure in an engaging means, in which shocks in the speed change on high level are reduced always in up-shift speed change irrespective of dispersion of a control system. CONSTITUTION:A first speed change hydraulic control means f1 is provide which obtains fixed output shaft torque as required irrespective of dispersion of a control system by feed-back controlling oil pressure in a high speed stage friction engaging means (b) or low speed stage engaging means (c) so that after the start of the speed change deviation of an actual torque change rate from a preset desired torque change rate is recuced. Also, a second speed change hydraulic control means f2 is provided which is similarly feed-back controlled with respect to the actual output shaft torque value obtained every sampling time and the desired output shaft torque value preset at sampling time intervals in place of the actual torque change rate and preset desired torque change rate.

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 which detects an output shaft torque during upshifting and controls the hydraulic pressure of an engaging means.

[0002]

2. Description of the Related Art Conventionally, many applications have been filed for detecting the input shaft torque or the output shaft torque during gear shifting to control the hydraulic pressure of the engaging means. Among them, as a shift control device for an automatic transmission that detects the output shaft torque at the time of shifting and controls the hydraulic pressure of the engaging means, for example, Japanese Patent Laid-Open No. 2-2569.
The one described in Japanese Patent No. 59 is known.

The above-mentioned conventional sources show a technique for reducing shift shock by detecting the output shaft torque of an automatic transmission and correcting and controlling the engagement speed of a clutch or a brake according to the output shaft torque. There is.

[0004]

However, in the above conventional shift control device for an automatic transmission, the actual torque value (or acceleration value) is compared with the set value, and based on the magnitude relation, Since the hydraulic pressure rise (duty ratio) per unit time is controlled to be changed, there are problems listed below.

(1) It is an open loop control, and the output shaft torque does not meet the demand.

(2) The output shaft torque is not constant due to the influence of changes over time and variations in the friction coefficient of the friction engagement means, and variations in the hydraulic control device.

The present invention has been made in view of the above problems. In a shift control device for an automatic transmission, which detects an output shaft torque during a shift and controls the hydraulic pressure of an engaging means, an upshift shift is performed. At the same time, the challenge is to always achieve a high level of shift shock reduction regardless of variations in the control system.

[0008]

In order to solve the above-mentioned problems, in the shift control device for the automatic transmission according to claim 1, the deviation between the actual torque change rate and the preset target torque change rate after the shift is started. Feedback control of the hydraulic pressure of the high speed friction engagement means or the low speed engagement means so as to reduce the first speed hydraulic pressure control means for obtaining a constant output shaft torque as required regardless of variations in the control system. Was established.

That is, as shown in the claim correspondence diagram of FIG. 1 (a), an output shaft torque detecting means a for detecting the output shaft torque of the automatic transmission, and a high speed step friction engaging means b for achieving a high speed step. , A low-speed gear engagement means c for achieving a low-speed gear that is one gear lower than the high-speed gear, and an up-shift gear shift for switching from the low-speed gear engagement means c to the high-speed frictional engagement means b The shift start determination detecting means d for detecting the start determination, and after detecting the shift start determination, the output shaft torque value is sampled from the output shaft torque detecting means a at a predetermined sampling time to obtain the torque change rate per unit time. The torque change rate calculating means e and the high speed step friction engaging means b or the low speed step so as to reduce the deviation between the actual torque change rate from the torque change rate calculating means e and the preset target torque change rate. Characterized in that it includes a first shift hydraulic pressure control unit f1 for feedback control of the oil pressure of the engagement means c.

In order to solve the above-mentioned problems, in a shift control device for an automatic transmission according to a second aspect of the present invention, the actual output shaft torque value obtained at each sampling time after the start of gear shifting and the target output preset to the sampling time interval. By feedback controlling the hydraulic pressure of the high-speed stage friction engagement means or the low-speed stage engagement means so as to reduce the deviation from the shaft torque value,
A second speed change hydraulic control means is provided to obtain a constant output shaft torque as required regardless of variations in the control system.

That is, as shown in the claim correspondence diagram of FIG. 1B, an output shaft torque detecting means a for detecting the output shaft torque of the automatic transmission, and a high speed gear friction engaging means b for achieving a high speed gear. , A low-speed gear engagement means c for achieving a low-speed gear that is one gear lower than the high-speed gear, and an up-shift gear shift for switching from the low-speed gear engagement means c to the high-speed frictional engagement means b A shift start determination detecting means d for detecting a start determination, an output shaft torque value sampling means g for sampling an output shaft torque value from the output shaft torque detecting means a after the shift start determination is detected, and the output shaft torque value sampling means g; The deviation between the actual output shaft torque value obtained at every sampling time from the output shaft torque value sampling means g and the target output shaft torque value set in advance at the sampling time interval is made small. Characterized in that a second shift hydraulic pressure control unit f2 for feedback control of the hydraulic pressure of the high speed stage friction engagement element b or slow Dangakarigo means c.

[0012]

The operation of the present invention will be described.

When the shift start determination detecting means d detects a shift start determination of an upshift shift for switching from the low speed engagement means c to the high speed friction engagement means b,
The torque change rate calculating means e samples the output shaft torque value at a predetermined sampling time from the output shaft torque detecting means a for detecting the output shaft torque of the automatic transmission after detecting the shift start determination, and outputs the torque per unit time. The rate of change is required.

Then, in the first shift oil pressure control means f1, high speed friction engagement is performed so as to reduce the deviation between the actual torque change rate from the torque change rate calculation means e and the preset target torque change rate. The hydraulic pressure of the means b or the low speed engagement means c is feedback-controlled.

Therefore, the hydraulic pressure is feedback-controlled so that the actual torque change rate matches the target torque change rate, so that the high-speed frictional engagement means b varies with time and the first shift hydraulic pressure control means f1 varies. It is possible to eliminate the influence of the above, and as a result, it is possible to obtain a constant output shaft torque as required.

The operation of the invention according to claim 2 will be described.

When the shift start judgment detecting means d detects a shift start judgment of an upshift shift for switching from the low speed engagement means c to the high speed friction engagement means b,
In the output shaft torque value sampling means g, the output shaft torque value is sampled at a predetermined sampling time from the output shaft torque detecting means a for detecting the output shaft torque of the automatic transmission after detecting the shift start determination.

In the second shift oil pressure control means f2, the actual output shaft torque value obtained from the output shaft torque value sampling means g at every sampling time and the target output shaft torque value set in advance at the sampling time interval are set. The oil pressure of the high-speed stage frictional engagement means b or the low-speed stage engagement means c is feedback-controlled so as to reduce the deviation.
Therefore, the hydraulic pressure is feedback-controlled so that the actual output shaft torque value matches the target output shaft torque value.
It is possible to eliminate the influence of variations in the shift oil pressure control means f2, and as a result, it is possible to obtain a constant output shaft torque as required.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

First, the structure will be described.

FIG. 2 is an overall system diagram of an automatic transmission to which the shift control device of the embodiment of the present invention is applied.

In FIG. 2, reference numeral 1 is a throttle sensor, and 2 is a throttle sensor.
Is a speed sensor, 3 is an automatic transmission control unit, 4 is an automatic transmission, 5 is a torque sensor (corresponding to output shaft torque detecting means), 6 is an internal combustion engine control unit, 7 is an internal combustion engine, and 8 is a control valve unit. is there.

FIG. 3 is a gear train diagram of an automatic transmission to which the shift control device according to the embodiment of the present invention is applied.

In FIG. 3, 11 is a torque converter,
12 is an oil pump, 13 is an input shaft, 14
Is a band brake (corresponding to low speed gear engaging means), 15 is a reverse clutch, 16 is a high clutch (corresponding to high speed gear friction engaging means), 17 is a front sun gear, 18 is a front pinion, 19 is a front internal gear, 20 is a front planet carrier, 21 is a rear sun gear, 2
2 is a rear pinion, 23 is a rear internal gear, 24
Is a rear planet carrier, 25 is a forward clutch, 26 is a forward one-way clutch, 27 is an overrun clutch, 28 is a low one-way clutch, 29
Is a low & reverse brake, 30 is a parking pole,
Reference numeral 31 is a Perkingi gear, and 32 is an output shaft.

In the control pressure chamber of the band brake 14,
Brake pressure oil passage 34 provided with a solenoid valve 33 for a brake that controls the release hydraulic pressure during upshifting from the second speed to the third speed
Are connected.

The control pressure chamber of the high clutch 16 has 2
A clutch pressure oil passage 36, which is provided with a clutch solenoid valve 35 that controls the engagement hydraulic pressure during upshifting from the third speed to the third speed, is connected.

The brake solenoid valve 33 and the clutch solenoid valve 35 are provided in the control valve unit 8 and are controlled by the duty command from the automatic transmission control unit 3.

Next, the operation will be described.

(A) Gear shifting action FIG. 4 is a shift schedule preset in the automatic transmission control unit 3, and FIG. 5 is a fastening operation table showing the engagement actions of the clutch and the brake at each shift position.

During traveling, throttle opening information and vehicle speed information are input to the automatic transmission control unit 3 from the throttle sensor 1 and the speed sensor 2.

FIG. 4 shows this throttle opening information and vehicle speed information.
When the current running state obtained from the throttle opening and the vehicle speed is within the range of the second speed, as shown in FIG. 5, the forward clutch 25 and the band brake 14 are checked. By engaging, the shift position is set to the optimum second speed for the current running state.

When at least one of the throttle opening and the vehicle speed changes and the running state obtained from the throttle opening and the vehicle speed crosses the 2 → 3 shift line, an upshift gear shift start command from the 2nd gear to the 3rd gear is issued. Is output (corresponding to the shift start determination detection means).

In response to this shift start command, the band brake 14 is released, and the high clutch 16 is engaged by shift hydraulic control which will be described later.

(B) Shift hydraulic pressure control operation FIG. 6 is a flow chart showing the flow of shift hydraulic pressure control operation performed by the automatic transmission control unit 3 at a control cycle of 20 msec in response to a shift start command (first shift hydraulic pressure control means). Equivalent). First, each step will be described.

In step 60, the target oil pressure value PASFT (n) and the target torque change rate T'SFTTRG (n) are read in from the data setting map shown in FIG.

In step 61, the hydraulic pressure output value PA ^* SFT (n)
Is calculated by correcting the target hydraulic pressure value PASFT (n) with the hydraulic pressure correction value ΔP, and a duty command for obtaining this hydraulic pressure output value PA ^* SFT (n) is output to the clutch solenoid valve 35. The hydraulic pressure correction value ΔP is obtained by converting the hydraulic pressure in step 66, which will be described later, and the first control cycle (n =
In the case of 1), ΔP = 0.

In step 62, the actual torque value TTRU (n) is read from the torque sensor 5.

In step 63, the actual torque change rate T'SFTR (n) is calculated by the following equation from the actual torque values TTRU (n + 1) and TTRU (n) read at intervals of 20 msec (torque change). Equivalent to rate calculation means).

T′SFTR (n) = {TTRU (n + 1) −TTRU (n)} / 20 ms In step 64, the actual torque change rate T′SFTR (n) and the target torque change rate T′SFTTRG (n). Is compared with.

In step 65, the target torque change rate T'S
A deviation ΔT 'between FTTRG (n) and the actual torque change rate T'SFTR (n) is calculated.

In step 66, the deviation Δ of the torque change rate is
According to the function of T ′, the magnitude of the deviation is the hydraulic pressure correction value ΔP.
Is converted to.

In step 67, the control cycle n is n = n +
Rewritten to 1.

At step 68, the hydraulic pressure correction value ΔP is ΔP.
Is set to = 0.

(C) Outline of hydraulic control FIG. 8 is a schematic explanatory diagram of hydraulic control based on the data setting map shown in FIG.

First, in the first control cycle, the routine proceeds from step 60 to step 61. At step 61, the target hydraulic pressure value PASFT (1) is used as it is as the hydraulic pressure output value PA ^* SFT (1), and at step 62, the actual value is obtained. The torque value TTRU (1) is read.

Even in the second control cycle, step 60 →
In step 61, the target hydraulic pressure value P
ASFT (2) is directly used as the hydraulic pressure output value PA ^* SFT (2), and when the actual torque value TTRU (2) is read in step 62, steps 63 to 66 are performed, and the hydraulic pressure correction value Δ
P is calculated.

In the third control cycle, step 60 →
Proceed to step 61, and at step 61, the hydraulic pressure output value P
A ^* SFT (3) is obtained by correcting the target hydraulic pressure value PASFT (3) with the hydraulic pressure correction value ΔP. In the subsequent control cycle n, the hydraulic pressure output value PA ^*
SFT (n) is obtained by correcting the target hydraulic pressure value PASFT (n) with the hydraulic pressure correction value ΔP.

Therefore, as shown in FIG. 8, in the first and second control cycles, the actual torque change rate T'SFTR is
(1), T'SFTR (2) is the target torque change rate T'SFTTRG (1), T '
Although the rate of change is greater than SFTTRG (2), in the third control cycle, the actual torque change rate T'SFTR (3) is adjusted by hydraulic pressure correction.
Becomes a change rate smaller than the target torque change rate T'SFTTRG (3) and approaches the target characteristic. After that, the actual torque change rate T'SFTR (n) follows the target torque change rate T'SFTTRG (n). Will be controlled to match.

If the hydraulic pressure control is continued in the open loop without performing the hydraulic pressure correction by the feedback control, the actual torque change rate characteristic gradually deviates from the target torque change rate characteristic.

(D) Time-dependent characteristics during gear shift FIG. 9 shows a gear shift start command, an output shaft torque, a target torque change rate, an actual torque change rate, a release side hydraulic pressure, and a fastening side during an upshift from the second speed to the third speed. It is a time chart which shows each characteristic of oil pressure.

Target torque change rate TargetT 'in the middle part of FIG.
From the characteristics of the actual torque change rate RealT ', it can be seen that the actual torque change rate RealT' follows well, although there is a slight delay with respect to the target torque change rate TargetT 'within the range of the feedback control.

Looking at the characteristics of the disengagement side hydraulic pressure and the engagement side hydraulic pressure in the lower part of FIG. 9, the disengagement side hydraulic pressure without the hydraulic control shows a characteristic that it smoothly decreases, but the engagement side hydraulic pressure with which the feedback hydraulic control is performed is shown. It can be seen that is fluctuating little by little due to the oil pressure correction.

Then, the output shaft torque Tout in the upper part of FIG.
Looking at the characteristics of, the feedback hydraulic pressure control that causes the actual torque change rate RealT 'to follow the target torque change rate TargetT' is performed, so that the torque fluctuation width during the gear shift transition period is small and the gear shift shock is suppressed. I understand.

As described above, in the shift control device for the automatic transmission of the embodiment, when the upshift shift start command from the 2nd speed to the 3rd speed is output, the actual torque change rate T'SFTR (n ) And the preset target torque change rate T'S
By performing feedback control of the hydraulic pressure of the high clutch 16 so as to reduce the deviation ΔT ′ from FTTRG (n), gear shift hydraulic pressure control is performed to obtain the required constant output shaft torque Tout regardless of variations in the control system. 2 because it is a device
High clutch 16 during upshift from 3rd to 3rd
Is eliminated, and the influence due to the variation of the hydraulic control system is eliminated, and a high level shift shock reduction can always be achieved.

Although the embodiments have been described above with reference to the drawings, the specific configuration is not limited to the embodiments, and modifications and additions within the scope of the present invention are included in the present invention. Be done.

For example, in the embodiment, the example in which the feedback control of the hydraulic pressure of the engaging means is performed based on the torque change rate of the output shaft torque has been shown. However, the hydraulic pressure of the engaging means is determined by the actual output shaft torque value and the target output shaft torque value. The feedback control may be performed as an example.

The high speed friction engaging means is a multi-disc clutch,
It refers to a multi-disc brake, a band brake, etc., and the low speed engagement means is meant to include a one-way clutch and a one-way brake mechanically operating to these friction engagement means.

[0058]

According to the present invention of claim 1, in a shift control device for an automatic transmission, which detects an output shaft torque during a shift and controls a hydraulic pressure of an engaging means, a change in an actual torque after a shift is started. The feedback control of the hydraulic pressure of the high-speed stage frictional engagement means or the low-speed stage engagement means is performed so as to reduce the deviation between the rate and the preset target torque change rate. Since the first shift oil pressure control means for obtaining a constant output shaft torque is provided, it is possible to obtain a high level shift shock reduction at any time during upshifting, regardless of variations in the control system.

According to the second aspect of the present invention, in a shift control device for an automatic transmission which detects an output shaft torque during a shift and controls the hydraulic pressure of an engaging means, the shift control device obtains each sampling time after the start of a shift. The feedback control of the hydraulic pressure of the high-speed friction engagement means or the low-speed engagement means is performed so that the deviation between the actual output shaft torque value and the target output shaft torque value set in advance in the sampling time interval is reduced. Since the second shift hydraulic pressure control means for obtaining the required constant output shaft torque regardless of the variation of the control system is provided, at the time of the upshift, a high level shift shock reduction is always achieved regardless of the variation of the control system. The effect of being able to do is obtained.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to claims showing a shift control device for an automatic transmission according to the present invention.

FIG. 2 is an overall system diagram of an automatic transmission to which the shift control device of the embodiment is applied.

FIG. 3 is a gear train diagram of an automatic transmission to which the shift control device of the embodiment is applied.

FIG. 4 is a diagram showing a shift schedule preset in the automatic transmission control unit of the embodiment apparatus.

FIG. 5 is an engagement operation table showing engagement operations of the clutch and the brake at each shift position of the embodiment apparatus.

FIG. 6 is a flowchart showing a flow of shift hydraulic pressure control operation performed by the automatic transmission control unit of the embodiment apparatus.

FIG. 7 is a data setting map used in shift hydraulic control of the embodiment apparatus.

8 is a schematic explanatory diagram of hydraulic control based on the data setting map shown in FIG. 7.

FIG. 9 is a time chart showing each characteristic of a shift start command, an output shaft torque, a target torque change rate, an actual torque change rate, a release side hydraulic pressure, and an engagement side hydraulic pressure during an upshift shift from the second speed to the third speed. ..

[Explanation of symbols]

 a output shaft torque detecting means b high speed friction engaging means c low speed engaging means d shift start determination detecting means e torque change rate calculating means f1 first shift hydraulic pressure control means f2 second shift hydraulic pressure control means g output shaft torque value Sampling means

Claims (2)

[Claims] 1. An output shaft torque detecting means for detecting an output shaft torque of an automatic transmission, a high speed friction engagement means for achieving a high speed stage, and a low speed stage which is a shift stage lower by one than the high speed stage. Low-speed gear engagement means, a low-speed gear engagement means for switching from the low-speed gear engagement means to a high-speed gear frictional engagement means, a shift start determination detection means for detecting a shift start determination of an upshift shift, and after the shift start determination is detected, A torque change rate calculating means for sampling the output shaft torque value from the output shaft torque detecting means at a predetermined sampling time to obtain a torque change rate per unit time, and an actual torque change rate from the torque change rate calculating means in advance. First shift hydraulic control means for feedback-controlling the hydraulic pressure of the high speed friction engagement means or the low speed engagement means so as to reduce the deviation from the set target torque change rate. Shift control device for an automatic transmission, characterized in that it comprises. 2. An output shaft torque detecting means for detecting an output shaft torque of an automatic transmission, a high speed friction engaging means for achieving a high speed step, and a low speed step which is a speed step lower than the high speed step. Low speed gear engagement means, a shift start determination detection means for detecting a shift start determination of an upshift gear shifting from the low speed gear engagement means to a high speed friction engagement means, and after the shift start determination is detected, An output shaft torque value sampling means for sampling an output shaft torque value from the output shaft torque detecting means at a predetermined sampling time; an actual output shaft torque value obtained at each sampling time from the output shaft torque value sampling means; and a sampling time in advance. Feed the oil pressure of the high-speed friction engagement means or low-speed engagement means so as to reduce the deviation from the target output shaft torque value set in the interval. Shift control device for an automatic transmission, characterized in that Tsu includes a second shift hydraulic pressure control means for click control, the.