JPH01112072A - Slip control device for torque converter - Google Patents

Abstract

PURPOSE:To perform proper control of a slip, by a method wherein, while a slip amount is increased to the set number of revolutions due to deceleration, feed forward control is made on a slip amount control means, and after it is increased to the set number of revolutions, feedback control is performed. CONSTITUTION:A control means 22 contains a deceleration slip region map, and controls a slip amount of a torque converter 1 through a slip amount regulating means 21. After a deceleration state is detected by a deceleration state detecting means 29, while a relative difference between the numbers of revolutions, i.e. a slip amount, detected by a number of revolutions of an engine sensor 27 and a number of revolutions of turbine sensor 28 is increased to the set number of revolutions, feedback control is made on the action of the slip amount regulating means 21 in a state to specify a duty factor. Thereafter, while the number of revolutions is increased to a set value and a vehicle is escaped from a deceleration state, feedback control is effected to converge a slip amount to a target value. This constitution enables proper control of a slip amount.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a slip control device for a 1-lux converter, and more particularly to a slip control device for a torque converter that improves fuel efficiency during vehicle deceleration.

(Prior Art) A conventional slip control device for a torque converter of this type is disclosed in Japanese Patent Application Laid-Open No. 61-99763. The proposed torque converter slip control device is capable of arbitrarily adjusting the amount of slip between the input and output members of the torque converter by reducing the coupling force of the direct coupling clutch interposed between the input and output members. The operation of the direct coupling clutch that adjusts the amount of slip is controlled as follows.

That is, an accelerator pedal release detection means for detecting the release of the accelerator pedal, a measuring means for measuring the duration of the release of the accelerator pedal, and a measuring means for measuring the duration of the release of the accelerator pedal;
direct-coupled clutch feedforward control means for controlling the operation of the direct-coupling clutch by a signal corresponding to a set slip of the torque converter, and the torque converter maintains the target slip amount until release of the accelerator pedal is stopped after the set time elapses; A control device is provided with a direct-coupled clutch feedback control means for feedback-controlling the direct-coupling clutch, and feedforward controls the operation of the direct-coupling clutch after the accelerator pedal is released until the release duration reaches a set value. to control the amount of slip of the torque converter. After the above-mentioned duration exceeds the above-mentioned set value, and until the release of the accelerator pedal is stopped, the operation of the direct coupling clutch is feedback-controlled to converge the slip amount of the torque converter to the target value. control.

Therefore, according to the proposal, when the engine torque fluctuation range is large immediately after the accelerator pedal is released, the slip amount of the torque converter is controlled over a set fixed period of time to absorb the large engine torque fluctuation by feedforward control. After the set time has elapsed during which the range of engine torque fluctuations becomes smaller, the amount of slip is adjusted using feedback control to converge to the minimum target value that can absorb the engine torque fluctuations during this period. Can be done.

Therefore, compared to performing slip control using only feedback control, instability of slip control such as hunting phenomenon can be prevented from occurring immediately after the accelerator pedal is released when the engine torque fluctuation range is large, and control response delay is prevented. By minimizing the time as much as possible, this prevents the engine speed from dropping suddenly during the response delay time, making it possible to further extend the fuel cut time.

(Problem to be Solved by the Invention) By the way, when the accelerator pedal is released to cause the vehicle to decelerate, the deceleration of the vehicle is affected by running resistance such as the slope angle of the running road and the weight on the vehicle. , the degree of depression of the brake pedal, etc., and the speed at which the engine speed decreases also varies accordingly.

However, in the above proposal, feedforward control is performed for a set period of time immediately after detecting the release of the accelerator pedal, without taking into account the engine speed factor, and after the set time has elapsed. Since the slip control is switched to feedback control, there is a problem in that the slip control cannot be switched from feedforward control to feedback control in response to the various reductions in engine speed.

That is, if the deceleration of the vehicle speed is large, the engine speed may drop below the fuel recovery speed before the set time elapses. In such a case, it becomes impossible to further extend the fuel cut time by feedback control near the fuel recovery rotation speed where the engine torque fluctuation range becomes small.

Additionally, if the set time is made too short to deal with this, the engine speed may still be within the range of large torque fluctuations after the set time has elapsed, and in such a case, the subsequent There is a risk that the feedback control may not be able to follow the torque fluctuation range, causing the slip control to become unstable, such as a hunting phenomenon occurring.

The present invention has been made in view of the above circumstances, and its purpose is to lengthen the fuel cut time as much as possible when the vehicle decelerates, and to minimize engine torque fluctuations at that time. The object of the present invention is to provide a highly stable torque converter slip control device that can absorb

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a slip amount adjusting means for adjusting the slip between the input and output members of a torque converter, and a slip amount adjusting means for adjusting the slip between the input and output members of the torque converter, and a slip amount adjusting means for adjusting the slip between the input and output members of the torque converter. a deceleration state detection means for detecting a deceleration state of the vehicle by depressing the vehicle, etc.; and a deceleration state detection means for detecting the deceleration state of the vehicle by the detection means until the amount of slip between the input and output members of the torque converter increases to a set rotation speed. During this period, the operation of the slip amount adjusting means is feedforward controlled with its duty rate constant, and from the time when the slip amount reaches the set rotational speed until the time when the slip amount is released from the deceleration state, the slip amount is controlled. A slip control device for a torque converter includes control means for feedback controlling the operation of the slip adjustment means so that the slip converges to a target value.

(Function) According to the present invention having the above configuration, after the deceleration state detection means detects the deceleration state of the vehicle, while the slip amount between the input and output members of the torque converter increases to the set rotation speed,
The operation of the slip base adjusting means is feedforward controlled by the control means so that its duty rate is kept constant. At this time, the slip amount is limited to an extent that can absorb the engine torque fluctuation during this time, and the slip 1 adjusting means is operated almost simultaneously with the detection of the deceleration state without any response delay time, so the slip 1 adjustment means is directly connected to the input member side. A sudden drop in engine speed is prevented, the fuel cut time is extended, and control is performed without hunting phenomena.

In addition, in such a state, when the slip level gradually increases and reaches the set rotation speed, the control means will not operate until the vehicle exits the deceleration state, such as by depressing the accelerator pedal again. The operation of the slip adjustment means is controlled by switching to feedback control so that the slip amount converges to the target value. At this time, the amount of slip is converged to the minimum target value that can absorb engine torque fluctuations during this time, and the decrease in engine speed is further slowed to extend the fuel consumption time.

(Embodiment) A preferred embodiment of the slip control device for a torque converter according to the present invention will be described in detail below with reference to the accompanying drawings.

First, the structure of the torque converter 1 and its control hydraulic circuit 2 will be explained with reference to FIG. a pump 5 that rotates integrally with the pump 5; and a turbine 6, which is an output member that is rotatably provided on the other side of the case 4 so as to face the pump 5 and is rotationally driven by the rotation of the pump 5 via hydraulic oil. , a stator 7 that is interposed between the pump 5 and the turbine 6 and performs a torque increasing action when the speed ratio of the turbine rotation speed to the pump rotation speed is below a predetermined value; and a stator 7 that is interposed between the turbine 6 and the case 4. Lock-up (directly connected) clutch 8
and has. The rotation of the turbine 6 is outputted by a turbine shaft 9 and inputted to a speed change gear mechanism (not shown), and the lock-up clutch 8 is connected to the turbine shaft 9, and the case 4 is connected to the lock-up clutch 8.
When the engine output shaft 3 and the turbine shaft 9 are fastened to each other, the engine output shaft 3 and the turbine shaft 9 are directly connected through the case 4.

Further, hydraulic oil is introduced into the torque converter 1 through a main line 10 led from an oil pump (not shown) through a lock-up valve 11 and a converter inline 12, and the pressure of this hydraulic oil is The lock-up clutch 8 is always urged in the engagement direction, and a lock-up release line 14 led from the lock-up valve 11 is connected to the space 13 between the clutch 8 and the case 4. When hydraulic pressure (release pressure) is introduced into the space 13 from the line 14, the lock-up clutch 8 is released. The torque converter 1 also includes a pressure holding valve 15.
A converter outline 17 is connected to the oil cooler 16 via the converter outline 17 for delivering hydraulic oil to the oil cooler 16.

On the other hand, the lock-up valve 11 has a spool 11a.
and a spring 11b that biases it to the right in the drawing, and a pressure regulating boat 11d and a drain boat 11e to which the main line 10 is connected on both sides of the boat 11C to which the lockup release line 14 is connected. is provided.

Also, at the right end of the valve 11 in the drawing, there is a control line 18 for applying pilot pressure to the spool 11a.
is connected to the control line 18, and a duty solenoid valve 20 is installed in a drain line 19 branched from the control line 18. This duty solenoid valve 20 is turned on and off at a duty rate according to an input signal.
By repeating FF to open and close the drain line 19 in extremely short cycles, the pilot pressure in the control line 18 is adjusted to a value corresponding to the duty rate.

Then, the pilot pressure is applied to the lock-up valve 1.
The pressure is applied to the spool 11a of the first spool 11a in a direction opposite to the biasing force of the spring 11b, and the release pressure in the lock-up release line 14 is applied to the spool 11a in the same direction as the biasing force of the spring 11b. The spool 11 is
a moves and the lockup release line 14 is communicated with the main line 10 (vA pressure boat 11d) or the drain boat 11e, so that the lockup release pressure is changed to the pilot pressure, that is, the duty solenoid valve 2.
When the duty rate is at its maximum value, the drain from the control line 18 is at its maximum, and the pilot pressure or release pressure is at its minimum. As a result, the lock-up clutch 8 is completely engaged, and when the duty rate is at the minimum value, the drain suspension is minimized, and the pilot pressure or release pressure is maximized, so that the lock-up clutch 8 is fully engaged.
is now completely released.

At a duty rate between the maximum value and the minimum value, the lock-up clutch 8 is in a slip state, and in this state, the release pressure is adjusted according to the duty rate, so that
The amount of slip of the lock-up clutch 8 is controlled.

That is, the lock-up clutch 8 and the control hydraulic circuit 2 constitute a slip amount adjusting means 21 that adjusts the slip m between the input and output members of the torque converter 1.

By the way, as shown in FIG. 1, the operation of the slip amount adjusting means 21 is controlled by a control means 22. This control means 22 is specifically an electronic controller (microcomputer), and the vehicle speed sensor 23
．． Throttle distance sensor 24. Gear position sensor 25. Water temperature sensor 26° Engine speed sensor 27. Turbine rotation speed sensor 28. Various information signals are input from deceleration state detection means 29 and the like that detect the deceleration state of the vehicle.

Specifically, the deceleration state detection means 29 is an accelerator pedal switch, and when the accelerator pedal 30 is released, the accelerator pedal switch is turned on, indicating that the vehicle has transitioned to a deceleration state. It is designed to detect.

On the other hand, the electronic controller 22 stores in advance in its ROM a fuel cut rotation speed NG for cutting fuel supply to the engine according to the engine rotation speed when the engine is decelerated, and a fuel recovery rotation speed for restarting fuel supply. number Nr, a set rotational speed NS for determining the magnitude of the relative rotational speed difference between the turbine rotational speed Nt and the engine rotational speed Ne (that is, slip ff1Na), and a region in which deceleration slip control is performed as shown in FIG. A deceleration slip area map 31 indicating a deceleration slip area map 31 is stored, and the operation of the slip amount adjusting means 21 is controlled according to the information signals inputted from the above-mentioned various sensors according to the flowcharts shown in FIGS. 3 and 4. It is supposed to be done.

Note that the deceleration slip control area map 31, not shown in FIG. A deceleration slip control area A is set. In addition, in this embodiment, the deceleration slip control area A is set within the 3rd speed range of the shift schedule, and the shift down'>speed from 4th gear to 3rd gear is higher than normal?
: It is set to the 5th speed side and matches the above V2.

Next, the control contents of this embodiment will be explained according to the flowcharts shown in FIGS. 3 and 4.

First, in step S10, the CPU of the electronic controller 22 receives R.
The initial setting from OM is the deceleration slip area map 31 and the fuel cut rotation speed Nc.

The fuel recovery rotation rllNr and the set rotation speed NS are read, and then in step 820 the engine rotation speed Ne, the turbine rotation speed Nt, the vehicle speed V, and the gear position G are read.
, water temperature T, throttle opening, and ON-OFF of the accelerator pedal switch (deceleration state detection means 30) are detected.

Next, in step S30, the accelerator pedal switch is turned on.
It is determined whether or not the vehicle is in the deceleration state Ntr3 (that is, the vehicle is in a deceleration state), and if the result is No.9, the deceleration slip control is turned off in step S40, and then the control is ended. On the other hand, if the determination in step S30 is YES, it is determined in the next step S50 whether the vehicle speed V is within the deceleration slip control region A.

If the determination in step 550 is No9, the flow of control is returned to the previous step of step S40, and then the control is terminated; if YES, in the next step 860, the water temperature T is set to the set value (for example, 80 degrees Celsius). It is determined whether or not this is the case, and if the answer is No, it is assumed that the warm-up operation has not been completed, and the process returns to the previous stage of step S40, and then the control is ended.

If the determination in step 860 is YES, then in step 870 it is determined whether the engine speed Ne is equal to or higher than the fuel cut rotation speed N0, and if this is YES,
If so, the CPU of the electronic controller controls the duty solenoid valve 2 of the slip adjustment means 21 in the next step S80.
The duty ratio is kept constant (for example, 50%) with respect to 0, and the operation control signal is outputted in a feedforward manner, and then the flow of control is returned to the previous stage of step S20. At this time, the slip MW4 regulating means 21 that receives the operation control signal presses the lock-up clutch 8 with a predetermined pressing force to absorb the slip amount between the input and output members of the torque converter 1 to absorb torque fluctuations from the engine 1. Adjust to the extent possible.

On the other hand, if the determination in step 370 is NOl, the process moves to step S90 and slip ff1Na (= l N
After e-Nt l ) is calculated, it is determined in step 8100 whether the slip amount Na is greater than or equal to the set rotational speed NS. If this determination is YES, the flow of control is returned to the previous stage of step S80, and the feedforward control described above is executed. On the other hand, step 5100
If the determination in step 8110 is No, it is determined in the next step 8110 whether or not the engine speed Ne exceeds the fuel recovery rotation speed Nr.

Then, the determination at step 8110 is No.

If so, the flow of control is returned to step 840, whereupon the control is terminated and the determination at step 5110 is YES.
, then in the next step 8120, the CPU controls the slip level adjusting means 21 by feedback so that the slip amount of the 1-lux converter 1 converges to the target value, and then the control flow returns to the stage before step 5110. It will be done.

That is, the control flowing to step $120 is processed according to the flowchart shown in FIG. 70 in this figure 4
The chart shows the feedback control number routine,
When control flows to this subroutine, first, in step 5121, a deviation 4N (=Na-No) of the slip amount Na with respect to the target slip amount NO is calculated.

Next, in step 5122, the CPU controls the control parameter A.
, 8 (constant or variable) and step 51
In step 23, feedback ff1lJ is calculated according to the following equation (i).

u=Ax, aN+84N' (i) Here, AN' is the deviation of the actual slip suspension Na obtained in step 5122 during the previous control with respect to the target slip amount NO.

Then, in step 5124, the duty rate corresponding to this feedback ff1LI is corrected In, 4.
D is set based on the map in Fig. 6, and this correction fit
, 60, the current duty rate D (=D' +, 6D) is calculated by correcting the previous duty rate D'. Thereafter, in step 5125, the CPU replaces the deviation 6N found in the current control with the previous value 2N', and in step 8126, the CPU adjusts the slip length adjustment means 21 so that the duty rate corrected as described above is obtained. An operation control signal is output to the duty solenoid valve 20.

Next, in step 5127, the CPU detects the vehicle speed ■, the engine rotational speed Ne, the turbine rotational speed Nt, and the ON-OFF state of the accelerator beggle switch, and then in step 812.
In step 8, it is determined whether or not the accelerator pedal switch is in the ON state, and if this is YES, the next step 5129
It is determined whether the vehicle speed V is in the deceleration slip region A or not. If this judgment is YES, step 513
After calculating the slip debt Na (-l Ne-Nt I ) with 0, the process returns to the upper stage of step 5110. Further, if the judgments in steps 8129 and 8130 are Ne9, the control flow is changed to step 84.
After the transition to the previous stage of 0, the control is ended.

According to the above feedback control, when the current and previous deviations, 6N, , 6N' are negative, that is, the slip INa
When is smaller than the target slip ff1No, the feedback control meter and the correction ffi,4D of the duty rate also become negative, and accordingly the duty rate decreases and the amount of drain from the duty solenoid valve 20 decreases. , spool 11a of lock-up valve 11
As a result, the lock-up clutch is controlled in the releasing direction, the slip td increases, and the target slip ff1 is increased.
N.

will come close to.

Also, on the contrary, the deviation JN of this time and the previous time.

When AN' is positive, that is, when the slip ff1Na is larger than the target slip InN0, the duty ratio is increased and the pilot pressure or lock-up release pressure is decreased, so that the lock-up clutch 8 is controlled in the engagement direction. The slip ff1Na decreases and approaches the target slip MNO as well. In addition, the deviation this time is 6N
If the sign and the previous deviation JN' are opposite, that is, slip ω
When Na has almost converged to the target slip fit No, the feedback control amount U or duty rate correction 10 will be zero or a very small value, and therefore the slip MNa will be equal to or very close to the target slip mNo. It will be maintained.

Therefore, according to the torque converter slip control device configured as described above, after the deceleration state detection means 29 detects the deceleration state of the vehicle as shown in the graph of FIG. While the relative difference with the rotational speed, that is, the slip lNa, increases to the set rotational speed Ns, the duty rate of the torque converter 1 is kept constant by feedforward control of the duty solenoid valve 20 of the slip m adjustment means 21. As a result, the direct coupling clutch 8 is pressed with a constant pressing force, and its slip m is limited to an extent that absorbs engine torque fluctuations during this period. In this state, the slip ff1Na gradually increases and when it reaches the set rotation speed NS, the control of the operation of the duty solenoid valve 20 is switched to feedback control, and after that, the accelerator pedal is depressed again to enter a deceleration state. Until this occurs, the slip INa of the torque converter 1 is adjusted so as to converge to the minimum target value that can absorb engine torque fluctuations during this period.

Therefore, it is possible to perform more appropriate slip control according to the decrease in engine speed Ne, which varies depending on the deceleration state of the vehicle, and it is possible to absorb fluctuations in engine torque while suppressing the decrease in engine speed. You will be able to extend the fuel cut time by delaying it as much as possible.

At this time, even if the switch is made from feedforward to feedback, the engine speed Ne at the time of the switch is already in a region where the engine torque fluctuation width is small, so there is a risk that hunting may occur and the control may become unstable. There are few.

In the above-described embodiment, the vehicle deceleration state detection means 29 is constituted by an accelerator pedal switch that detects the release of the accelerator pedal, but these two deceleration state detection means are composed of a brake switch that detects the release of the brake pedal. You can also replace it with a pedal switch.

(Effects) In summary, according to the present invention, after the vehicle is shifted to a deceleration state, the torque converter is turned on while the relative difference between the engine speed and the turbine speed, that is, the slip period, increases to the set speed.・The operation of the slip adjustment means that adjusts the slip speed between the output members is feedforward controlled with a constant duty rate, and the slip is controlled until the set rotation speed is reached and the vehicle exits the deceleration state. ff1
Since the operation of the WA node is feedback-controlled so that the slip period converges to the target value, the slip of the torque converter can be adjusted more appropriately according to the state of decrease in the engine speed, which varies depending on the state of deceleration of the vehicle. It is possible to extend the fuel cut time and absorb engine torque fluctuations as much as possible, thereby achieving improved fuel efficiency and reduced vibration during vehicle deceleration.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a preferred embodiment of a slip control device for a torque converter according to the present invention, FIG. 2 is a detailed diagram showing an example of a torque converter and its slip amount adjusting means, and FIG. FIG. 4 is a flowchart showing details of the feedback control stage shown in FIG. 3, FIG. 5 is a deceleration slip control area map, and FIG. 6 is a diagram showing the feedback control stage. FIG. 7 is a graph showing the timing of switching from feedforward control to feedback control by the present control device. 1...Torque converter 2...Control hydraulic circuit 4...Input member Case 6...Output member Turbine 8...Direct connection Clutch 20...Duty solenoid valve 21...Slip amount adjustment means 22...Control means 29...Deceleration state detection means Patent applicant Mazda Corporation Agent
Patent Attorney - Ken Color Shaft Circumference Patent Attorney Masatoshi Matsumoto Figure 6 + Figure 7 BUJ-Dopui Hood VJ II
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Claims (1)

[Scope of Claims] Slip amount adjusting means for adjusting the amount of slip between the input and output members of the torque converter, and deceleration state detection means for detecting the deceleration state of the vehicle by releasing the accelerator pedal or depressing the brake pedal, etc. and, after the detection means detects the deceleration state of the vehicle, the operation of the slip amount adjusting means is controlled at its duty until the slip amount between the input and output members of the torque converter increases to the set rotation speed. Feedforward control is performed with the rate constant, and the slip amount adjusting means controls the slip amount so that the slip amount converges to the target value from when the slip amount reaches the set rotation speed until the deceleration state is released. A slip control device for a torque converter, comprising: control means for feedback controlling the operation of the torque converter.