JPH02120564A - Lock-up control device for automatic transmission gear - Google Patents

Abstract

PURPOSE:To aim at improving accelerating performance as well as durability by releasing the release control when the speed ratio exceeds the set value at the releasing time of the control of a lock-up mechanism in the locking direction and resetting the control of the lock-up mechanism in the locking direction. CONSTITUTION:If the accelerating operation of an engine is detected while a lock-up mechanism 5 is controlled in the locking direction by means of a control means 30 in the fixed engine operating area, the control of the lock-up mechanism in the locking direction is released by means of a control releasing means 32. As a result, a power transmitting path becomes a path through a torque converter 2 so that the torque multiplying action is displayed and the accelerating performance is improved. During the display of the torque multiplying action, the turbine rotating speed is increased, so that the difference between the turbine rotating speed and the engine speed is reduced, the speed ratio becomes gradually larger, the torque ratio becomes smaller, and the torque multiplying action is thereby lowered. When the speed ratio exceeds the set value, the torque multiplying action is lowered, a control reset means 34 is actuated so that the lock-up mechanism 5 is controlled again to be in the locking direction by the control means 30, and thus the accelerating operation is continued.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lockup control device for an automatic transmission, and more particularly to an improvement in the lockup control device for releasing the lockup during acceleration operation to improve acceleration performance.

(Prior Art) Conventionally, as a lock-up control device for an automatic transmission of this type, there is one disclosed in, for example, Japanese Patent Laid-Open No. 140960/1983. This device is equipped with a lock-up mechanism that directly connects the input and output shafts of the torque converter, and while the basic configuration is such that the lock-up mechanism is engaged in a predetermined engine operating range, acceleration operation is not started in this predetermined engine operating range. In this case, the lock-up mechanism is released from the lock-up control and the power transmission path is passed through the torque converter, so that the torque multiplication effect of the torque converter is exerted to improve acceleration performance. .

(Problems to be Solved by the Invention) By the way, when the engagement control of the lock-up mechanism is released during acceleration operation as described above, and when the acceleration operation is detected by a change in the throttle valve opening, the following disadvantages occur. In other words, if the driver requests sudden acceleration and quickly increases the throttle valve opening and holds that opening value, even after the opening is maintained, the intake air amount is still in the process of increasing and the engine speed is The engine speed is also in the process of increasing, and the engine continues to accelerate. Therefore, if it is determined that the acceleration operation has ended when the change in the throttle valve opening degree ends, the lock-up mechanism engagement control is restarted at this point and the multiplication action of the torque converter is stopped, and the subsequent acceleration No improvement in sexual performance can be expected. Moreover, since the lock-up mechanism is re-engaged while the engine speed is increasing, the facing of the lock-up mechanism is severely worn, leading to a decrease in its durability.

The present invention has been made in view of the above, and its purpose is to improve acceleration performance and to increase the torque multiplication by making the torque converter exert the torque multiplication effect for a long time during engine acceleration. The purpose is to suppress wear on the facing of the lock-up mechanism and improve its durability as the action takes longer.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, after the torque converter exhibits the torque multiplication effect during acceleration operation, the torque converter is operated until the torque multiplication effect is almost eliminated. We will continue to release the lock-up mechanism fastening control. In this case, the torque multiplication effect (torque converter torque ratio) changes the speed ratio (-turbine speed/engine speed) to a large value side, as seen from the speed ratio-torque ratio characteristic shown in Figure 6. Since it has a characteristic of gradually decreasing as the torque increases, by detecting the speed ratio, it is possible to detect a situation where the torque multiplication effect is almost eliminated.

In other words, the specific solution of the present invention is based on an automatic transmission equipped with a torque converter 2 and a lock-up mechanism 5 that directly connects the input and output shafts of the torque converter 2, as shown in FIG. . Then, the predetermined engine operation 1Bri
a control means 30 for controlling the lock-up mechanism 5 in the tightening direction in the predetermined engine operation region; an acceleration operation detection means 31 for detecting acceleration operation of the engine in the predetermined engine operation region; A control release means 32 is provided for releasing the fastening direction control of the lock-up mechanism 5 by the control means 30 during operation. Furthermore, speed ratio detection means 33 for detecting the speed ratio of the torque converter 2;
When the speed ratio detected by the speed ratio detecting means 33 exceeds a set value when the locking direction control of the lock-up mechanism 5 is released by the control releasing means 32, the releasing control of the control releasing means 33 is released and the control means 30 The structure includes a control return means 34 for returning control of the fastening direction of the lock-up mechanism 5.

(Function) With the above configuration, in the present invention, the lock-up mechanism 5 is controlled in the fastening direction by the control means 30 in a predetermined engine operating range (completely fastened or at a predetermined rotational speed between the input and output shafts of the torque converter 2). (including both fastening force control that causes a difference), when accelerated engine operation is detected,
The fastening direction control of the lock-up mechanism 5 is released by the control release means 32. As a result, the power transmission path becomes a path via the torque converter 2, and its torque multiplication effect is exerted, thereby improving acceleration performance.

Then, while the torque multiplication effect is exerted, as the turbine rotation speed increases and the difference with the engine rotation speed decreases, the speed ratio gradually increases and the torque ratio gradually decreases.
The torque multiplication effect decreases.

When the speed ratio exceeds the set value, the torque multiplication effect is small (torque ratio is small), and at this point, the control return means 34 is activated and the lock-up mechanism 5 is redirected in the fastening direction by the control means 30. The acceleration operation will be continued in this state.

In that case, in a situation where the torque multiplication effect is effective (a situation where the speed ratio is below the set value), the fastening direction control of the lock-up mechanism 5 is reliably released, so that the torque multiplication effect is maintained for as long as possible during acceleration operation. is effective, the response to the driving stone's acceleration operation at the initial stage of acceleration is increased, and acceleration performance can be improved.

Moreover, the period during which the lock-up mechanism 5 is controlled to open (
Since the period during which the torque multiplication effect is effective becomes longer, wear of the facing of the lock-up mechanism can be suppressed.

(Effects of the Invention) As explained above, according to the lock-up control device for an automatic transmission according to the present invention, when the engine is accelerated in an operating range in which the lock-up mechanism is controlled in the engagement direction, the torque of the torque converter is multiplied. The lock-up mechanism is reliably controlled to open while the lock-up mechanism is in effect, and the torque multiplication effect is maintained for as long as possible, increasing the acceleration at the beginning of acceleration operation and improving the follow-up response to the driver's acceleration operation. It is possible to improve acceleration performance. Furthermore, the opening control time of the lock-up mechanism can be extended, wear of the facing can be suppressed, and its durability can be improved.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 to F.

FIG. 2 shows the structure and hydraulic control circuit of the torque converter section of the automatic transmission. In the figure, 1 is an engine output shaft, 2 is a torque converter that transmits the power of the engine output shaft 1 to a subsequent stage, and the torque converter 2 is connected to the engine output shaft 1 and rotates integrally with a pump 2a. ,
A turbine 2b disposed facing the pump 2a, and a stator 2 disposed between the two to perform torque multiplication.
The front end of a converter output shaft 3 is connected to the turbine 2b, and the rear end of the converter output shaft 3 is equipped with a gear mechanism (not shown) having, for example, four forward speeds and one reverse speed. ) are concatenated.

Further, in the torque converter 2, the turbine 2b
A lock-up clutch (lock-up mechanism) 5 that directly connects the input/output shaft of the torque converter 2, that is, the engine output shaft 1 and the converter output shaft 3, is arranged between the converter case 4 and the converter case 4 in front of the converter case 4. The lock-up clutch 5 is biased in the direction of engagement (rightward in the figure) by the hydraulic pressure in the engagement-side hydraulic chamber 5a formed at the rear thereof, and conversely opened by the hydraulic pressure in the opening-side hydraulic chamber 5b formed at the front. It is biased in the direction.

Further, the hydraulic control circuit A has a function of engaging and disengaging the lock-up clutch 5 and controlling the engagement force. In the hydraulic control circuit A, 10 is a lock-up control valve that adjusts the supply of oil to the lock-up clutch 5. The lock-up control valve 10 includes a spool 10a that slides from side to side in the drawing within its internal space, and a spring 10b that urges the spool 10a to the right in the drawing. Also, line pressure introduction port 1 where line pressure is introduced.
0c, and a line pressure supply boat 10d that communicates with the introduction boat 10c and supplies line pressure, and the line pressure supply boat 10d is communicatively connected to the engagement side hydraulic chamber 5a of the lock-up clutch 5. There is. Furthermore, it has a pressure regulating boat 10e and a tank boat 10r, which are connected in communication with the opening side hydraulic chamber 5b of the lock-up clutch 5, and the hydraulic pressure PI of the pressure regulating boat 10e is connected to the left end of the spool 10a via a hydraulic passage 11. It's working. Further, oil is supplied to the right end of the spool 10a in the figure through a hydraulic passage 12, and a tank 14 is connected to the hydraulic passage 12 through a tank passage 13. , a duty solenoid valve SO opens and closes the tank passage 13.
I, is interposed.

The above duty solenoid valve Sol has a duty ratio of 1.
When the duty ratio is 00%, the tank passage 13 is always in communication; when it is 7.0%, it is always closed. By adjusting this duty rate, the opening rate of the hydraulic passage 12 to the tank 14 is adjusted, It has a function to adjust the 12 hydraulic pressure PO to the hydraulic pressure according to the duty rate. Therefore, the hydraulic pressure acting on the right end of the spool 10a (hydraulic pressure Po of the hydraulic passage 12)
and the hydraulic pressure acting on the left end (hydraulic pressure P1 of the pressure regulating boat 10e)
The spool 10a is moved left and right in relation to the biasing force SP of + spring 1 and Ob, and the pressure regulating boat 10c is alternately communicated with the line pressure introduction port 10c and the tank boat 10[', and finally The oil pressure P+ of the pressure regulating port 10e (that is, the release oil pressure of the lock-up clutch 5) is transferred to the oil pressure passage 12.
The engagement force of the lock-up clutch 5 is adjusted as the oil pressure according to the oil pressure Po. Therefore, when the duty rate is -100%, the action of the release hydraulic pressure is released and the lock-up clutch 5 is fully engaged with the maximum engagement force, and as the duty rate gradually decreases, the engagement force gradually decreases, and the duty rate is reduced. When the ratio is -0%, the release oil pressure is set to the maximum value, and the lock-up clutch 5 is completely opened.

Furthermore, FIG. 3 shows a basic electric circuit configuration for controlling the engagement force of the two-legged lock-up clutch 5.

In the figure, 20 is a CPU, and the CPU 20 includes a vehicle speed sensor 21 that detects the vehicle speed, an opening sensor 22 that detects the throttle valve opening, and a gear position that detects the gear ratio based on the current gear position. Detection signals from the sensor 23, the engine rotation speed sensor 24 that detects the engine rotation speed, and the turbine rotation speed sensor 25 that detects the turbine rotation speed are input. As shown in FIG. 4, the CPU 20 operates based on the detection signals of the above-mentioned sensors in a predetermined low engine load region (slip region) where the throttle valve opening is low among the engine operating regions determined by the vehicle speed and the throttle valve opening. Then, the duty rate of the duty solenoid valve SQL is calculated, and the lock-up control valve 10 is operated and controlled using this duty rate to control the rotation speed difference (slip amount) between the input and output shafts 1.3 of the torque converter 2 (slip amount). At the same time, the duty rate is fixed at 100% in a predetermined engine operating range (lock-up range), which is a high vehicle speed range, and the lock-up clutch 5 is fully engaged. Furthermore, in other areas, the duty rate is fixed at 0% and the lock-up clutch 5 is completely opened.

Next, the operation control of the lock-up clutch 5 will be explained based on the control flow shown in FIG.

After the start, in step S1, the engagement direction control release flag C0N (C0N- is set when the engagement direction control of the lock-up clutch 5 is released in the slip region and lock-up region).
1. After initially setting C0N-0) to C0N-0 in other settings, in step S2, read the vehicle speed V, throttle valve opening T0, engine speed Ne, and turbine speed NL from each sensor. Then, in step S3, the speed ratio e(e-N(/Ne)) of the torque converter 2 is calculated.In addition, in step S4, the current and previous throttle valve openings TVO, T
The change mTV in the throttle valve opening is calculated from the difference in VO', and in step S5, the rate of change in the throttle valve opening TVD (-TV/Δt) is calculated based on the amount of change TV and the sampling time Δt of the throttle valve opening. Calculate.

Thereafter, in step S6, it is determined whether the vehicle is in the slip region shown in FIG. 4 based on the vehicle speed V and the throttle valve opening θ. If it is in the slip region, the value of the engagement direction control release flag CON is determined in step S7, and normally C
0N-0, so in step S8 the throttle valve opening change mTV is compared with a predetermined value TVXI (e.g. +Odcg) which corresponds to acceleration driving, and in step S9 the throttle valve opening change rate TVD corresponds to acceleration driving. It is compared with a predetermined value TVDX l (for example lOdeg/5ee). Here, each of the predetermined values TVXI and TVDXI is set to a small value in a low speed gear, and a large value in a high speed gear. If TV<TVXI or TVD<TVDXI, it is determined that it is not during acceleration operation, and step SIO is performed.
The engagement force of the lock-up clutch 5 is controlled by adjusting the duty D so that the slip amount between the input and output shafts of the torque converter 2 reaches the target value, and the engagement direction control release flag CON is set to C0N-0. .

On the other hand, if TV≧TVXl and -)TVD≧TVDXl, it is determined that the torque converter 2
In order to exhibit the torque multiplication effect, the duty D is set to D-0% in step SI+ to control the lock-up clutch 5 to the fully open state, and the release flag CON of the engagement direction control is set to C0N-1. Set.

Then, in step S+2, the speed ratio e of the torque converter 2 is determined, and the speed ratio e is such that the torque ratio in the speed ratio-torque ratio characteristic shown in FIG. 6 is 1.0.
If the value is less than or equal to x (e≦ex), the situation is such that the torque multiplication effect can be exerted (torque ratio≧1), so the current release control of the lock-up clutch 5 is continued in step S13. The throttle valve opening value TVO is replaced with the previous value TVO°, and the process returns to step S2.

If e>ex in step 512, the situation is such that the torque multiplication effect disappears (torque ratio is 1), so the process returns to step S+6 and the engagement force control (slip control) of the lock-up clutch 5 is performed. We will restart.

Further, if it is determined in step S6 that the vehicle is not in the slip region, it is determined in step SI4 whether or not the vehicle is in the lock-up region. If the vehicle is in the lock-up region, the same control as in the case of the slip region is performed. That is, in step S15, the value of the engagement direction control release flag CON is determined, and since it is normally C0N-0, step S15 is determined.
16, the throttle valve opening change mTl/ is set to a predetermined value TVX2.
In step S17, the throttle valve opening change rate T
VD is compared with a predetermined value TVDX2. Here, the predetermined value T
VX2. Since the lock-up region of TVDX2 is set on the high vehicle speed side with respect to the slip region, the predetermined values TVXI, TVD in the slip region are set in order to reduce the frequency of release control of the lock-up clutch 5 at the beginning of acceleration.
This is a larger value than XI. And TV<TVX2matahaT
VD < TVDX2 When the vehicle is not in acceleration operation, in step S18, the duty D is fixed at D-100% and the lock-up clutch 5 is controlled to a fully engaged state, and the engagement direction control release flag CON is set to C0N-0. Set to .

In addition, in the case of accelerated operation where TV≧TVX2 and TvD≧TvDx2, the duty D is set to D− in step SI9.
0%, the lock-up clutch 5 is controlled to be fully open, the torque multiplication effect of the torque converter 2 is exerted, and the release flag CON of the engagement direction control is set to C0.
Set to N-1. After that, in step 5211, the speed ratio e of the torque converter 2 is compared with the set speed ratio ex,
If the torque ratio of e≦eX≧1, the control to open the lock-up clutch 5 is continued to exert the torque multiplication effect. Then, if e>ex in step 52G, the torque ratio is 1, so step 518
The process returns to , and complete engagement control of the lock-up clutch 5 is resumed.

On the other hand, if the clutch is neither in the slip region nor in the lock-up region, the duty is set to DfcD-0% in step S2+, and the lock-up clutch 5 is controlled to be fully open.

Therefore, in the control flow shown in FIG. 5 above, step 8
6,510.314. The control means 30 is configured to control the lock-up clutch 5 in the engagement direction (engagement force control and complete engagement control) in the slip region and lock-up region (predetermined engine operating region) shown in FIG. 4 by S+8.
It consists of Also, steps S8, Sg, S+
6. S+7 constitutes an acceleration operation detection means 31 configured to detect acceleration operation of the engine within the predetermined engine operation region (slip region and lockup region) based on the change mTV and the rate of change TVD of the throttle valve opening. ing. Furthermore, in steps Sl+ and S+9, the control canceling means 3 cancels the engagement direction control of the lock-up clutch 5 by the control means 30 and controls it to the open state during the acceleration operation detected by the acceleration operation detection means 31.
2. In addition, in step S3, the speed ratio detection means 3 detects the speed ratio e of the torque converter 2.
3, and step S12-”S
10 and 82G-518, the control release means 3
2, the speed ratio e detected by the speed ratio detection means 33 when the lock-up clutch 5 fastening direction control is released is the set value e.
A control return means 34 is configured to release the release control of the control release means 32 and restore the engagement direction control of the lock-up clutch 5 by the control means 30 when the value exceeds x.

Therefore, in the above embodiment, for example, when the slip region exists, the engagement force of the lock-up clutch 5 is controlled, and the slip between the input and output shafts 1.3 of the torque converter 2 is controlled to the target value. .

Now, when starting υ0 speed operation from the above slip area,
As shown in FIG. 7, when the throttle valve opening increases, the engagement force control (slip control) of the lock-up clutch 5 is released, and the lock-up clutch 5 becomes completely open. As a result, the power transmission path becomes a path via the torque converter 2, and its torque multiplication effect is exerted, so that the acceleration of the vehicle is reduced when the slip control shown by the broken line in the figure is continued (speed ratio e= 0.8 to 0.9), it increases accordingly and becomes larger as shown by the solid line in the figure. When the speed ratio e is between e≦ey, there is a situation where the torque ratio is ≧1 as shown in FIG. The multiplication effect can be exerted for a maximum length of time, and the response to the driver's acceleration operation can be increased, thereby improving acceleration performance. In addition, since the release control time of the lock-up clutch 5 becomes longer, the wear of the facing can be suppressed and the durability of the lock-up clutch 5 can be improved by that much compared to the case where the engagement force is controlled.

Thereafter, as the turbine speed Nt increases, the speed ratio e increases, and when e>ey, the torque ratio becomes 1, so when e>ey, the lock-up clutch 5 is activated. The fastening force is controlled again. the result,
The acceleration operation can be continued satisfactorily under the condition of torque ratio -]. The case of acceleration operation from the slip region has been described above, but the same applies to the case of acceleration operation from the lockup region.

In the above embodiment, the lock-up clutch 5 is controlled in the engagement direction in both the slip region and the lock-up region, but the lock-up clutch 5 may be controlled to be fully engaged only in the lock-up region without providing the slip region. Of course, it can also be applied in the same way.

In addition, in the above embodiment, the change in throttle valve opening Eil
Although the acceleration driving is detected using the TV and the rate of change TVD, it may also be detected using the vehicle speed or the engine rotation speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 7 show embodiments of the present invention, FIG. 2 is a hydraulic circuit diagram for controlling the engagement force of the lock-up clutch, FIG. 3 is an electric circuit diagram for controlling the engagement force, and FIG. 5 is a flowchart of fastening direction control, FIG. 6 is a diagram showing the speed ratio-torque ratio characteristic of the torque converter, and FIG. 7 is an explanatory diagram of the operation. 1... Engine output shaft, 2... Torque converter,
3...Converter output shaft, 5...Lock-up clutch, 10...Lock-up control valve, SOL...
- Duty solenoid valve, 20... CPU, 30... Control means, 31... Acceleration operation detection means, 32... Control release means, 33... Speed ratio detection means, 34... Control return means.

Claims (1)

[Claims] (1) In an automatic transmission equipped with a torque converter and a lockup mechanism that directly connects an input/output shaft of the torque converter, a control means for controlling the lockup mechanism in the engagement direction in a predetermined engine operating range; an acceleration operation detection means for detecting acceleration operation of the engine in an engine operation region; a control release means for canceling the fastening direction control of the lock-up mechanism by the control means during the acceleration operation detected by the acceleration operation detection means; A speed ratio detection means for detecting the speed ratio of the converter, and when the speed ratio detected by the speed ratio detection means exceeds a set value when the lock-up mechanism fastening direction control by the control release means is canceled, the control release means detects the speed ratio of the converter. 1. A lock-up control device for an automatic transmission, comprising: control return means for releasing the release control and restoring control of the engagement direction of the lock-up mechanism by the control means.