JPH0314965A - Slip controller of fluid joint - Google Patents

Abstract

PURPOSE:To improve the responsiveness of control and the performance of convergence by setting a target value of differential pressure which controls slip conditions from the relation between an input torque and the input difference between input rotation and output rotation, and performing correction with deviation between the difference and the target value. CONSTITUTION:In a slip control device C of a fluid coupling A, in performing slip control by the differential pressure control between a fastening chamber of lockup clutch B and releasing chamber thereof, a differential target value is set with a setting means K, and a target differential pressure is set from the relation between an input torque and the difference between input and output rotations in correspondence with the target rotation difference preliminalily set by a setting means E based on the difference between the input torque and input and output rotation difference detected by detection means D, G. The differential pressure is controlled through differential pressure control means F. In this case, a correction means H corrects the target pressure difference in response to the deviation between the actual input-output rotational difference and the target rotational difference. It is thus possible to improve the responsiveness, convergence and stability of control against fluctuation of transmission torque and aging change.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a fluid coupling slip control device for controlling the slip state of a lock-up clutch in a fluid coupling provided with a lock-up clutch. be.

(Prior art) In general, a fluid coupling equipped with a lock-up clutch (
In a torque converter, the lock-up clutch is released at low vehicle speeds when engine torque fluctuations are transmitted to the wheels and vehicle ride comfort deteriorates, and the converter operates to have a torque increasing function and a torque fluctuation absorbing function. On the other hand, at high vehicle speeds where engine torque fluctuations are not a big problem, the lock-up clutch is engaged and the input and output shafts are directly connected, reducing energy loss due to slip in the fluid coupling and improving fuel efficiency. I am trying to make it work.

In addition, in a fluid coupling equipped with a lock-up clutch as described above, in the region of low vehicle speed and low load, it is preferable to set the lock-up state to the converter state from the point of view of improving fuel efficiency. As a result, engine torque fluctuations are directly transmitted to the wheels, causing vibrations in the vehicle body.

Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 57-33253, a lock-up clutch is used to improve fuel efficiency to some extent and reduce the transmission of torque fluctuations to suppress shift shock and vehicle body vibration. A slip control device is known that controls the converter to a predetermined slip state intermediate between a lock-up state and a converter state, thereby producing a predetermined rotation difference between input and output.

The control in the above-mentioned slip control device adjusts the differential pressure between the pressure in the engagement chamber that acts in the direction of engagement of the lockup clutch and the pressure in the release chamber that acts in the direction of release, so that the lockup clutch is brought into a predetermined slip state. A mechanism that controls differential pressure is adopted. Then, by controlling the differential pressure, the rotational speed on the input side and the rotational speed on the output side of the lockup clutch are set to a predetermined rotational speed difference, thereby achieving both fuel efficiency and running performance.

Specifically, slip control is performed using feedback control that adjusts the hydraulic pressure supplied to the lock-up clutch based on the input/output rotation difference, or control that maintains the hydraulic pressure supplied to the lock-up clutch at a set value. ing.

(Problem to be Solved by the Invention) However, in the above-described slip control of the lock-up clutch using feedback control of the rotation difference,
Depending on the magnitude of the input torque transmitted to the fluid coupling and its fluctuations, the response delay time until the rotation difference between the input and output reaches the target value may become longer, making it impossible to obtain an appropriate slip state, or causing the response speed to decrease. If the control gain in the feedback control is set large in order to increase the control gain, the control may lack stability and a hunting phenomenon may occur, or problems may arise in terms of control accuracy.

In addition, in a system that maintains the operating pressure for the lock-up clutch at a set value, if the magnitude of the input torque at the start of slip control changes depending on the engine operating state or vehicle driving state, appropriate slip control is performed. There is also a risk that they will not be able to respond to changing conditions.

In particular, in order to perform lock-up clutch slip control so that a predetermined rotational difference occurs between input and output, it is necessary to change the operating pressure supplied to the lock-up clutch in response to changes in input torque, that is, engine output. However, engine output is detected indirectly from, for example, engine speed and throttle opening, so if the throttle opening suddenly changes due to accelerator operation, the engine output will fluctuate with a delay. Therefore, an error occurs between the detected torque and the actual input torque.

Then, if control is performed directly corresponding to the detected torque,
The lock-up clutch operates close to the lock-up state before the input torque increases, inhibiting the increase in engine speed and reducing acceleration performance, or creating an unnecessarily large speed difference that reduces fuel efficiency. This may lead to problems such as a decline in
There is a possibility that sufficient responsiveness and convergence of slip control cannot be obtained.

In addition, when slip control of the lock-up clutch is performed based on various set values, these set values may be affected by errors and fluctuations in engine torque as input torque due to individual differences in the engine or changes over time, or hydraulic control. Errors and fluctuations in the actually applied pressure due to individual differences in the system or changes over time, as well as individual differences in the friction coefficient of the friction engagement member of the lock-up clutch or changes in the engagement characteristics due to changes over time, may deviate from the optimum value. ,
There also arises the problem that it cannot converge to a predetermined slip state.

Therefore, in view of the above circumstances, the present invention provides a slip control device for a fluid coupling that improves the responsiveness of rotation difference control and converges to a predetermined slip amount by suppressing changes due to aging and the like. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the slip control device for a fluid coupling of the present invention, as shown in the basic structure in FIG. 1, uses a fluid between an input element and an output element. The fluid coupling A, which has a converter function to transmit torque, is equipped with a lock-up clutch B that can directly connect an input element and an output element.

The engagement force of this lock-up clutch B is controlled by a slip control device C equipped with a differential pressure control means F that adjusts the differential pressure between the pressure in the engagement chamber that acts in the engagement direction and the pressure in the release chamber that acts in the release direction. controlled.

The slip control device C includes an input torque detection means D that detects the input torque input to the fluid coupling A, and a target rotation difference setting means E that sets a target rotation difference of the input/output rotation difference, and the input torque Signals from the detection means D and the target rotational difference setting means E are output to the target differential pressure setting means K. The target differential pressure setting means K sets a target differential pressure corresponding to the target rotational difference based on the relationship between the preset input torque and the rotation difference of the manned horn, and sets this target differential pressure under the differential pressure control. The differential pressure control means F controls the differential pressure at the lock-up clutch B to a set differential pressure.

Further, an input/output rotation difference detection means G for detecting the current input/output rotation difference is provided, and a correction means H receiving signals from the input/output rotation difference detection means G and the target rotation difference setting means E is configured to detect the current input/output rotation difference. The configuration is such that the target differential pressure set by the target differential pressure setting means K is corrected based on the deviation between the output rotational difference and the target rotational difference.

(Function) In the slip control device for a fluid coupling as described above, in order to control the slip state by differential pressure control between the engagement chamber and the release chamber of the lock-up clutch, the target value of the differential pressure is set by the target differential pressure setting means. , detects the input torque input to the fluid coupling and the input/output rotation difference, sets a target differential pressure corresponding to a preset target rotation difference, and controls the differential pressure to reach this target differential pressure, The deviation between the current input/output rotational difference and the target rotational difference is determined, and based on this deviation, the target differential pressure set by the target differential pressure setting means, which is the target of the differential pressure control means, is corrected by the correcting means, and aging changes etc. When the deviation becomes large in accordance with this, the target differential pressure is corrected to increase or decrease to improve control convergence and obtain stable slip control.

(Example) Embodiments of the present invention will be described below along with the drawings.

FIG. 2 shows an example of a slip control device for a fluid coupling together with a power plant of a vehicle to which it is applied.

The power plant includes an engine body 10 and an automatic transmission 20
Each cylinder in the engine body 10 (four cylinders) is supplied with an air-fuel mixture formed by intake air from an intake passage 16 in which a throttle valve 14 is disposed and fuel injected from a fuel injection valve. The generated torque is transmitted to the wheels via a power transmission path including the automatic transmission 20.

In addition, in the engine main body 10, fuel supply is stopped when the engine speed is above a predetermined value and the throttle is fully idle during deceleration, and when the engine speed becomes less than the predetermined value from this fuel cut state, fuel supply is restarted. Deceleration fuel control is performed.

The automatic transmission 20 includes a fluid coupling 24 (torque converter), a multi-gear type transmission mechanism 26, speed change control solenoid valves 1 to 5 for forming hydraulic pressure used for controlling these, and lock-up control. and a pressure circuit section 30 provided with a solenoid valve 6 and a solenoid valve 7 for pressure regulation.

The fluid coupling 24 is located between an input shaft 25 to which the output of the engine body 10 is input and an output shaft 39, as shown in FIG. A converter section 27 that transmits torque via fluid and a lock-up clutch 21 that transmits torque in a directly connected state or in a slip state are arranged in parallel.

The converter section 27 includes a bomb inverter 34 as an input element fixed to a drive plate 32 that rotates together with the input shaft 25, a turbine runner 36 that rotates together with three output shafts, a stator 35 between the two, and a one-way clutch. 38, the lock-up clutch 2l includes a torsion damper 23 spline-fitted to the output shaft 39 and a coil spring 23a attached to the torsion damper 23.
The clutch plate 22 is connected to the clutch plate 22 via the clutch plate 22.

Due to the arrangement of the lock-up clutch 21, a release chamber 43 is formed on the back side of the clutch plate 22 between it and the drive plate 32, and a fastening chamber 44 is formed on the opposite side. An oil passage 42 is connected to the release chamber 43 from the hydraulic circuit section 30.
Hydraulic pressure for disengaging the clutch plate 22 is supplied through the oil passage 41 , and hydraulic pressure for engaging the clutch plate 22 is supplied to the engagement chamber 44 through the oil passage 41 . The lock-up clutch 21 is in a lock-up state in which hydraulic pressure is supplied to the engagement chamber 44 to directly connect the bomb impeller 34 and the Yuichi bottle runner 36, and in a lock-up state in which hydraulic pressure is supplied to the release chamber 43 to directly connect the bomb impeller 34 to the pump impeller 36. - Released state in which the turbine runner 34 and the turbine runner 36 are not engaged (converter state B)
Furthermore, when hydraulic pressure is supplied to both the tightening chamber 44 and the releasing chamber 43 and the differential pressure ΔP is within a predetermined range, the relative rotation between the pump impeller 34 and the turbine runner 36 is controlled. The allowable slip state is reached, and the differential pressure Δ
As P increases, the amount of slip decreases and the state approaches the close-up state. Note that the fastening chamber 44 is connected to an oil cooler 48 through an oil passage 47 in which a check valve 46 is disposed.

Parts of the hydraulic circuit section 30 that are involved in controlling the operation of the fluid coupling 24 include a lockup shift valve 51, a lockup pressure regulating valve 52, and the lockup control solenoid valve 6.
and a pressure regulating solenoid valve 7. The lock-up shift valve 51 is divided into a first subroutine 56 and a second subroutine 57 for hydraulic adjustment to boats a, d, and h.
The operation of the port switches ports b, c, e-g to open/close communication and drain. Further, the lock-up pressure regulating valve 52 switches the communication opening/closing of the point j=m and the draining by the operation of the spool 60 accompanying the oil pressure adjustment to the ports }i and n.

In the lock-up shift valve 51, the oil pressure of the oil pump 45 is made constant by the constant pressure forming part 50, and the oil pressure is regulated by the pressure regulating solenoid valve 7, and the boat a is supplied with the same. 2 spool 57
The oil pressure reduced by the constant pressure forming section 50 is supplied to the port d between the boat h, and the oil pressure of the oil pump 45 regulated by the lock-up control solenoid valve 6 is supplied to the boat h. The hydraulic pressure supply to the joint 24 is switched to switch between a converter state, a lock-up state, and a slip state. In addition, the lock-up pressure regulating valve 5
2, the throttle pressure pt regulated by the throttle pressure forming section 61 in accordance with the throttle opening is supplied to the port i.
On the other hand, the boat n is supplied with the duty control pressure Pd, which is made constant in the constant pressure forming section 50 and regulated by the pressure regulating solenoid valve 7, and the duty control pressure Pd is supplied to the boat n.
The slip amount is controlled by adjusting the differential pressure ΔP between the release chamber 4 and the release chamber 43 by adjusting :JyJ.

A description of the change in the state of the fluid coupling 24 due to the operation of the lockup shift valve 51 and the lockup pressure regulating valve 52 will be omitted here, but the details can be found in the specification of Japanese Patent Application No. 1983-27ge07 filed by the same applicant. Please refer to the description.

Further, as shown in FIG. 2, in order to control the operation of the hydraulic circuit section 30, solenoid valves 1 to 5 for speed change control, solenoid valves for lock-up control 6, and solenoid valves for pressure regulation are built into the hydraulic circuit section 30. The drive signal Ca-C is applied to the valve 7.
A control unit 100 is also provided which outputs each g.

This control unit 100 includes a throttle valve 1
A detection signal St obtained from a throttle opening sensor 81 that detects the opening degree Th of No. 4, a detection signal SV obtained from a vehicle speed sensor 82 that detects the vehicle speed V, and a shift 1 position sensor that detects the operating position of the shift lever. 83, a detection signal Sn obtained from the engine rotation speed sensor 84 that detects the engine rotation speed Ne (input rotation speed), and a detection signal Sn obtained from the engine rotation speed sensor 84 that detects the four rotation speed (output rotation speed) of the turbine runner 36. A detection signal Sm obtained from the rotation speed sensor 85, a detection signal Sa obtained from the accelerator sensor 86 which detects the amount of depression of the accelerator pedal, and an oil temperature sensor 87 which detects the temperature of the hydraulic oil supplied to the automatic transmission 8120. The obtained detection signal Su and the detection signal sb obtained from the brake sensor 88 that detects the amount of depression of the brake pedal are supplied, and other detection signals Sx necessary for controlling the automatic transmission 20 are also supplied.

The control unit 100 controls the speed change in the automatic transmission 20 and the operation of the lock-up clutch 21 with desired characteristics based on the various detection signals described above.

Automatic transmission 20 by this control unit 100
When controlling the speed change and the operation of the lock-up clutch 21), the control area is determined from the shift pattern shown in FIG. 4, which is mapped and stored in the built-in memory of the control unit 100. judge. This shift pattern is represented by the throttle opening Th on the vertical axis and the vehicle speed V on the horizontal axis, and the range of each gear at the time of upshifting is the upshift shift line Ua, Ub, Uc.
, and when the area changes, it is an upshift. On the other hand, the area of each gear during downshifting is shown by downshift shift lines Dd, De, and Df, and when the area changes, it is a downshift. It's time. In addition, the inside of the lock-up operating line Lg (4th gear) and Li (3rd gear), which are set in the region of relatively high vehicle speed and low throttle opening, is the lock-up region when transitioning to the lock-up state. Release from the up state is at the lock-up release line Lh (4th gear). It is indicated by Lj (3rd speed), and the time when the range changes is the time when the lock-up state is activated and the lock-up state is controlled to be released. moreover,
The inside of the slip control execution line Rj, which is set in the area of relatively low vehicle speed and low throttle opening, is the slip control area, and slip control is started when the line shifts to this area, and is set outside of this. This control is performed so that the slip control is canceled when the vehicle moves to an area outside the slip control release line Rk.

Then, the control unit 100 controls the above-mentioned shift line U.
If it is detected from the determination of a-Uc and Dd-Df that a shift-up condition or a shift-down condition is established, a drive signal Ca-Ce is selectively sent out to switch the gear stage in the transmission mechanism 26. , performs speed change control.

Further, if neither the lockup operating condition nor the slip control condition described below is satisfied, the supply of drive signals Cf and Cg to the lockup control solenoid valve 6 and the pressure regulating solenoid valve 7 is stopped. As a result, both the solenoid valves 6 and 7 are closed, the lock-up shift valve 51 and the lock-up pressure regulating valve 52 are in the position shown by the solid line in FIG. 3, and the hydraulic pressure regulated by the four regulator valves is directly transferred to the release chamber. 43 and the fastening chamber 4
4 is discharged to the oil cooler 48, the lock-up clutch 21 is released, and the converter section 27 transmits torque.

Further, when the lockup operating condition is satisfied, the drive signal Cf is supplied to the lockup control solenoid valve 6 to open it, and the pressure regulating solenoid valve 7 is closed by stopping the drive signal Cg.

As a result, the lock-up shift valve 51 is at the position indicated by the chain line.
The lock-up pressure regulating valve 52 is in the position indicated by the solid line, and the hydraulic pressure regulated by the regulator valve 49 is supplied to the engagement chamber 44, while the hydraulic pressure in the release chamber 43 is discharged to the oil van.
The lock-up clutch 21 is in a fastened state, resulting in a lock-up state in which input and output are directly connected.

On the other hand, if the throttle opening Th and the vehicle speed ■ are in the slip control region and the steady slip control condition is established, or if the shift up condition is established and the shift slip control condition is established, and if the throttle opening is When the deceleration slip control condition is established when the engine speed is decelerating to a predetermined value or higher with the engine fully closed, the drive signal Cf is supplied to the lock-up control solenoid valve 6 to open it, and the pressure regulating solenoid valve 7 is operated to a predetermined opening degree by supplying a drive signal Cg having a duty of 20% or more and an f value d.

As a result, in the lockup shift valve 51, the first subroutine 56 is at the position indicated by the solid line and the second subroutine 57 is at the position indicated by the chain line. The hydraulic pressure regulated by the regulator valve 49 is supplied to the engagement chamber 44, and the hydraulic pressure regulated by the regulator valve 49 is supplied to the release chamber 43. is supplied with reduced hydraulic pressure according to the duty value, and the lock-up clutch 21 outputs an input/output rotation difference ΔN between the input shaft 25 and the input shaft 25 according to the differential pressure ΔP obtained by subtracting the hydraulic pressure in the release chamber 43 from the hydraulic pressure in the engagement chamber 44. A slip state is created between the shaft 39 and the shaft 39.

In this case, the differential pressure ΔP is calculated from the throttle pressure pt, the duty control pressure Pd, and the biasing force Fa of the spring 62, and when CI + c2 is a constant, ΔP=C1
(P t P d) +F a/Cz,
Differential pressure ΔP is defined by throttle pressure pt and duty control pressure Pd. The throttle pressure Pt is formed to have the characteristics shown in FIG. 5, for example, with respect to the throttle opening Th.
d is formed to have the characteristics shown in FIG. 6, for example, with respect to the duty value d of the drive signal Cg. As a result, the differential pressure ΔP becomes larger as the throttle opening Th and the duty value d become larger, as shown in FIG. .

Furthermore, the transmittable torque Ts as the maximum torque that can be transmitted from the input 1dl25 to the three output shafts when the lock-a-knob clutch 21 is engaged is the clutch plate 2
For the friction coefficient μ of 2, the effective radius r, and the engagement area A, it can be expressed as Ts-ΔPI1μ●●A, and the value becomes larger as the differential pressure ΔP becomes larger. The input torque Ti of the fluid coupling 24 is equal to the engine generated torque Te transmitted to the input shaft 25, and if it is larger than the transmittable torque Ts, the input/output rotation difference ΔN will occur. The relationship between the input torque Ti and the input/output rotational difference ΔN is expressed by the solid lines I to ■ in Fig. 8 when the temperature of the hydraulic oil is, for example, 90°C and the differential pressure ΔP is set to 1 to 4 kg/cm2 as a parameter. The characteristics are as shown in .

From the above, when slip control is performed on the lock-up clutch 21 in the fluid coupling 24, it is first detected that the steady slip control condition has been established even though the shift slip control condition has not been established. In this case, the value of the engine generated torque Te is detected based on the throttle opening Th and the engine speed Ne.

Note that the value of the engine generated torque Te is obtained from a map set in advance according to the throttle opening Th and the engine speed Ne. For example, as shown in FIG. 9, the engine speed Ne is plotted on the horizontal axis. and throttle opening Th
Curve al-86 with (J/8~8/8) as a parameter
It is indicated by.

The value of the engine generated torque Te detected in this way is corrected for the oil temperature to obtain the transmitted torque T. The correction coefficient K1 is set to a larger value, and the transmission torque Tr is determined by multiplying the engine generated torque Te by this correction coefficient K1.

Furthermore, the above transmission 1・lux T' is the throttle opening Th
It is corrected by the amount of change in . This correction changes the detection of the engine output torque Te to the engine speed N as described above.
It is calculated from the map of e and throttle opening Th, but if the amount of change in throttle opening Th, that is, the speed of change, is large during acceleration when the accelerator opening is suddenly depressed, the actual increase in engine output will be delayed, and the map will change. This is to correct the deviation from the value so that the larger the throttle opening change amount, the smaller the value of the transmitted torque Tr. This correction is performed by calculating the amount of change ΔTh in the throttle opening Th from the difference from the previous throttle opening, and when this change ΔTh is a positive value and acceleration is occurring, the amount of change ΔTh in the throttle opening Th is calculated from a map as shown in FIG. A correction coefficient Kz, which is set to a smaller value of 1 or less as the amount of change ΔTh increases, is determined, and the transmission torque Tr is multiplied by this correction coefficient K2 to correct it. It should be noted that when the throttle opening change amount ΔTh increases, it deviates from the steady slip control region shown in FIG. 4.

And, corresponding to the value of the transmission torque Tr, between the input shaft 25 and the output I11139 in the fluid coupling 24,
A predetermined target rotational difference number that reduces energy loss and absorbs torque fluctuations generated by the engine.
, for example, the value of the differential pressure ΔP is set so as to produce 80 to 150 rpm, and the input torque Ti and the input/output rotation difference Δ in FIG.
The relationship between N and differential pressure ΔP is read from a map and set, and the target rotational difference No. is set optimally from the viewpoint of control responsiveness and convergence according to the current input/output rotational difference ΔN. Set to value.

To set this target rotational difference No., calculate the input/output rotational difference ΔN by subtracting the output rotational speed from the input rotational speed (engine rotational speed Ne), read the target rotational difference No. (initial value), and calculate the difference ΔN− between the two. Figure 11 or 12 depending on the value of No.
Search the correction value α or β from the diagram map and set the target rotational difference N.
The correction is made by adding or subtracting from o. The correction value α is a correction value when the input/output rotational difference ΔN is larger than the target rotational difference No by a predetermined value or more, and is a correction value that corrects the target rotational difference No lower to increase the differential pressure ΔP and decrease the input/output rotational difference ΔN. This improves responsiveness. In addition, the correction value β is a correction value when the input/output rotation difference ΔN is smaller than the target rotation difference No by a predetermined value or more, and the target rotation difference No is corrected higher to reduce the differential pressure ΔP and increase the input/output rotation difference ΔN. The objective is to improve responsiveness in the direction of increasing the rotational speed, and ultimately converge to the optimum target rotational difference No.

Furthermore, the map characteristic for determining the target differential pressure ΔP shown in FIG. - When the value of No exceeds the set value, the input/output rotation difference ΔN and the input torque Ti are shown in FIG.
Characteristic line I to find the target differential pressure ΔP using as a parameter
~ ■ are corrected upward or downward as indicated by chain lines or dashed lines, and the target differential pressure is corrected in response to changes in characteristics due to individual differences in fluid couplings, aging, wear of friction members, etc., and the optimum state is achieved. I try to adapt to changes.

Then, based on the map (FIG. 8) corrected as described above, the differential pressure ΔP is determined from the relationship between the target rotational difference No. and the transmitted torque T'. The corresponding duty value Dk is determined according to the characteristics shown in Figure 7, and the final output duty value d is determined by the deviation ΔN between the input/output rotational difference ΔN and the target rotational difference No to ensure the stability of the control system. The amount of change in the read duty value Dk is reflected by the value -No. In other words, the duty value d is determined based on the above deviation Δ
From N-No, the value of the correction coefficient F1+FZ is searched from a map as shown in FIG. 13. In addition, an update value ΔD is calculated using the calculation formula described in detail in the flowchart below using the duty value Dk obtained this time, the previous value Dk{, and the value Dk-2 from the previous time, and is added to the previous value Dk-1. to determine the final duty value d.

The control unit 100 then outputs a drive signal Cg having a duty value d corresponding to the set differential pressure ΔP.
is formed and supplied to the pressure regulating solenoid valve 7 for steady slip control.

The processing of the control unit 100 is shown in FIGS. 14 to 18.
This will be explained along the flowchart in the figure.

FIG. 14 shows the main routine of slip control. After the control starts, the type of slip control is determined in step S1, and whether it is steady slip S2, deceleration slip S3, or shifting slip S4 is determined in the control area shown in FIG. 18, which will be described later. The determination is made in accordance with the slip condition determined in the determination routine.

First, in the case of steady slip control S2, step S5
Then, the engine output torque Te is determined based on the detected engine speed Ne and the throttle opening Th based on the characteristics shown in FIG. After starting the timer T in step S6, the engine output torque T is determined in step S7.
e is corrected by the correction coefficient Ki according to the oil temperature,
This is to find the transmission torque Tr (input torque Ti).

Next, in step S8, the transmission torque T' is corrected by the amount of change ΔTh of the throttle opening Th, that is, the rate of change, based on the characteristics shown in FIG. This suppresses the deviation due to the delay in rising.

Then, in step S, the differential pressure map shown in FIG. 8 is corrected, and the detailed steps are shown in FIG. 15. First, in step S22, the input/output rotation difference ΔN is calculated as follows.
The turbine rotational speed Nt (output rotational speed) is subtracted from the engine rotational speed Ne (input rotational speed) to obtain the target rotational speed difference No. in step S23. Subsequently, in step S24, a deviation ΔN-No between the two is calculated, and in step S25, it is determined whether or not the deviation ΔN-No is positive. This judgment is YES
In this case, it is determined in step 82B that the input/output rotation difference ΔN
is larger than the target rotational difference No. by a predetermined value F1 or more, in step S27, the characteristic lines I to ■ in FIG. 8 are changed to chain lines 1' to
Map correction is performed in the direction of increasing the target differential pressure ΔP as shown in (2)'. Thereby, when the actual rotational difference ΔN is larger than the target rotational difference No, the target differential pressure ΔP is increased to correct the slip amount to be reduced.

On the other hand, when the determination in step S25 is No, it is determined in step S28 that the input/output rotation difference ΔN is the target rotation difference N.
If the predetermined value F2 or more is smaller than o, step S2'l
Then, map correction is performed on the characteristic lines I to ■ in FIG. 8 in the direction of decreasing the target differential pressure ΔP as indicated by broken lines I' to ■'. As a result, even though the actual rotational difference ΔN is smaller than the target rotational difference No, the target differential pressure ΔP is lowered to correct the slip amount to be reduced.

Subsequently, in step Sll (FIG. 14), the differential pressure ΔP is determined, and the detailed steps are shown in FIG. 16. First, in step S30, the input/output rotational difference ΔN is calculated by calculating the turbine rotational speed Nt from the engine rotational speed Ne, and in step S31, the initial value of the target rotational difference No (for example, 1
50 rpm).

Then, in step S32, a deviation ΔN-No between the two is calculated, and in step S33, it is determined whether or not the deviation ΔN-No is positive. If this determination is YES, step S34
It is determined that the input/output rotational difference ΔN is greater than the target rotational difference No. by the predetermined value E. If the deviation ΔN is larger than
-No value, the correction value α is searched from the map in FIG.
Subtract it from to correct it to a smaller value. On the other hand, when the determination in step S33 is NO, if the input/output rotational difference ΔN is smaller than the target rotational difference No by a predetermined value E2 or more in the determination in step S37, in step 338 the deviation ΔN−No.
Based on the absolute value of , the correction value β is searched from the map of FIG. 12, and in step S39, this correction value β is added to the target rotation difference No. to correct it to a larger value.

Further, if the determination in step S34 or S37 is No, and after correcting the target rotation difference No. as described above,
In step S4Q, the value of the differential pressure ΔP is determined from the relationship between the target rotational difference No. and the transmission torque Tr using the map shown in FIG.

Then, the process proceeds to step S12, and the corresponding duty value Dk is determined from the differential pressure ΔP and the throttle opening Th based on FIG. 7, and the duty value d to be finally output is calculated in step S13. d is output to the solenoid valve 7 in step S21 to drive it.

For details of the duty calculation of step SIO above, see Section 17.
As shown in the figure, in step 541, the deviation ΔN-No.
The value of the correction coefficient F1+FZ is searched from a map as shown in FIG. 13 based on the value of. This correction coefficient F l +
FZ is set to a larger value as the deviation ΔN-No becomes more positive and negative.

Then, the duty value Dk obtained this time is read in step S42, an updated value ΔD is obtained by calculation in step S43, and is added to the previous value Dk-1 to determine the final duty value d (S44). The calculation in step S43 is performed by multiplying the difference between the current duty value Dk and the previous value Dk-1 by a correction coefficient F1, and multiplying the difference between the previous value Dk-1 and the value Dk-2 from the previous time by a correction coefficient. It is calculated by adding the value multiplied by F2, and when the change in the state is large, the change in the duty value is increased, and when the change in the state is small, the fluctuation in the duty value d is made small to stabilize it. There is.

Next, in the case of castle speed slip control S3, step S14
Search the map for the minimum transmission torque during deceleration. During this deceleration, the engine is in a state where torque is transmitted from the wheels, so the minimum transmission torque transmitted from the wheels to the engine is determined in advance through experiments and stored in the built-in memory according to the engine speed. read out. Then, proceeding to step S6, the differential pressure ΔP is determined so as to reach a predetermined target rotational difference No corresponding to the transmitted torque,
Set the duty value d and perform deceleration slip control.

On the other hand, in the case of shift slip control S4, step S1
At Step 5, it is determined whether or not it is time to start slip control during gear shifting, and at the time of start, it is determined at Step 81G whether the immediately previous state is a slip control state, another converter state, or a lock-up state. If the previous state is the slip control state, in step 317 the duty value d is set to the value already set at that time immediately before the shift, and this value is set in step S2.
The solenoid valve 7 is driven with the duty value d being 0 during gear shifting (S21). In addition, if the previous state is converter or lockup state, step SI
In the same way as when the steady slip control condition is established in I3, the engine output torque Ti is detected from the engine speed Ne and the throttle opening Th, and in step S19, a predetermined target rotational difference No is determined by the transmission torque T' based on this. Set the differential pressure ΔP to be generated, determine the duty value d at which this differential pressure ΔP is obtained, and drive the pressure regulating solenoid valve 7 as the duty value d during gear shifting (S20, S21),
This shift slip control is performed until the shift operation is completed.

FIG. 18 shows a control region determination routine. In step S50, it is determined from the detected values of throttle opening Th and vehicle speed V whether or not the vehicle is within the steady slip control region based on the shift pattern shown in FIG. If it is within the steady slip control region, in step S51 the 4-3rd speed downshift line in which the throttle opening of the shift pattern is O is returned to the normal state, and then in step S52 it is determined whether or not the gear is being shifted. judge.

If the gear is not being shifted, the steady slip control Set
On the other hand, if the gear is being shifted, shift slip control S64 is performed when the shift is up as determined in step S53, and converter control S83 (lock-up release) is performed when the shift is down.

In addition, if it is outside the steady slip control region, step S
If the deceleration slip condition is satisfied in step S54, the operating state of the brake is determined by the on state of the brake switch. When the brake is operated, the 4th-3rd speed downshift line of the shift pattern is changed in step 35B to enhance the feeling of deceleration due to engine braking. Then, when this deceleration slip condition is satisfied, according to the shift determination in step S57, shift slip control (S64) is performed during the shift, while deceleration slip control (S65) is performed when the shift is not in progress.

Furthermore, if the deceleration slip condition is not satisfied outside the steady slip region, the 4th-3rd speed downshift line of the shift pattern is returned to the normal state in step S5g, and then it is determined whether or not the gear is being shifted in step S59. judge. and,
If the gear is not being shifted, the lock-up control (S
82), and when the lock-up region is not present, converter control (S63) is performed. Furthermore, the above step S
If the determination in step S59 is that the gear is being shifted, the shift slip control S64 is performed if the determination in step S53 is to shift up.
Converter control S83 is performed during downshift.

Based on the determination of the control mode as described above, when performing steady state, speed change, and deceleration slip control, slip control is performed based on the above-mentioned FIG. 14.

Note that converter control and lock-up control are performed using known control modes, and details are omitted.

Note that when the control unit 100 detects that the downshift condition has been satisfied, the control unit 100 stops supplying the drive signals Cf and Cg to both solenoid valves 6.7, except when the engine is in a deceleration state, This operates the lock-up clutch 21 in a released state. In addition, if it is detected that the upshift condition is established while the deceleration slip control condition is satisfied, the gear shift slip control is performed.
Further, if it is detected that the downshift conditions to 3-2nd speed and 2-1st speed have been established, the driving of both solenoid valves 6 and 7 is stopped, and the lock-up clutch 21 is released. .

According to the embodiment described above, during steady slip control, the differential pressure ΔP is calculated based on the map corrected according to the deviation between the actual input/output rotation difference ΔN and the target rotation difference No. According to the input torque Ti of the fluid coupling 24 corrected by By setting calculations to ensure stability, the response is an input/output rotation difference ΔN that is compatible with the operating state of the engine and that can reduce energy loss in the fluid coupling 24 and absorb torque fluctuations generated by the engine. It is possible to suppress fluctuations due to individual differences, changes over time, etc. by map correction, and to generate the map stably.

Thereby, it is possible to improve the fuel efficiency of the vehicle and to stably suppress vehicle body vibration.

Also, in the shift slip control, the differential pressure ΔP is set according to the transmission torque Tr, and slip control that is suitable for the operating state can be performed. Furthermore, in deceleration slip control, the input/output rotation difference is controlled according to the transmission torque T.
A good feeling of deceleration can be obtained by suppressing vehicle body vibration and cutting fuel for deceleration.

In the above embodiment, the actual input/output rotation difference ΔN
When the deviation between the target rotational difference No. and the target rotational difference No becomes larger than a predetermined value, the target differential pressure ΔP is corrected by correcting the map. It is possible to appropriately adopt means such as learning the state and correcting the target deviation ΔP.

Further, in the above embodiment, steady slip control is performed when it is detected that the shift pattern is in the slip control region of the shift pattern shown in FIG. 4, which is set based on the throttle opening degree and vehicle speed. The process may be performed when it is detected that either the throttle opening degree or the vehicle speed is in a specific range in the shift pattern.

(Effects of the Invention) According to the present invention as described above, when the slip state is controlled by differential pressure control between the engagement chamber and the release chamber of the lock-up clutch, the target value of this differential pressure is set by the target differential pressure setting means. , detects the input torque input to the fluid coupling and the input/output rotation difference, and controls the current input/output rotation to achieve the target differential pressure value set corresponding to the target rotation difference based on the relationship between the two. By determining the deviation between the difference and the target rotational difference and using the correcting means to correct the target differential pressure of the differential pressure control means based on this deviation, it is possible to cope with fluctuations in the transmitted torque and to adjust the speed over time. This makes it possible to perform appropriate differential pressure control in response to changes in basic characteristics, such as changes, with improved control responsiveness and good convergence and stability.

[Brief explanation of drawings]

Fig. 1 is a functional block diagram to clarify the configuration of the present invention, Fig. 2 is a schematic configuration diagram showing a slip control device for a fluid coupling in one embodiment together with a power plant of a vehicle, and Fig. 3 is the same as Fig. 2. A schematic configuration diagram showing the main parts of the example shown, FIGS. 4 to 13 are characteristic diagrams showing various control characteristics in slip control, and FIGS. 14 to 18 are flowcharts for explaining the processing of the control unit. It is. A, 24...Fluid coupling, B, 21...
Lock-up clutch, C...Slip control device, D...Input torque detection means, E...
・Target rotation difference setting means, F... Differential pressure control means,
G...Input/output rotation difference detection means, H...
Correction means, K...Target differential pressure setting means, 6...
...Solenoid valve for lock-up control, 7...
・Pressure regulating solenoid valve, 10... Engine body, 14... Throttle valve, 20... Automatic transmission, 30... Hydraulic circuit section, 43... ...
...Release room, 44...Conclusion room, 51...
・Lockup shift valve, 52...Lockup pressure regulating valve, 81...Throttle opening sensor, 8
2...Vehicle speed sensor, 100...Control unit. λMi Karo f 云L Do Bello ＼ Kamikai 1 Ni No. 9 Figure Ensemble 1 m afL Ne Enhi No. 10 Figure 11 Figure E1 A, 4 Shi 1 Ra Superintendent 2 ΔN-No E2 No. 12 Figure 14 N-NOI Fig. 13

Claims (1)

[Claims] (1) In a slip control device for a fluid coupling that can control the difference in input and output rotation by controlling the differential pressure between the engagement chamber and the release chamber of the lockup clutch and adjusting the engagement force of the lockup clutch, An input torque detection means for detecting input torque that is input, a target rotation difference setting means for setting a target rotation difference of the input/output rotation difference, and receiving signals from the input torque detection means and the target rotation difference setting means to preset the input torque. target differential pressure setting means for setting a target differential pressure in accordance with the target rotational difference based on the relationship between the input torque and the input/output rotational difference; differential pressure control means for controlling the pressure to a differential pressure; input/output rotation difference detection means for detecting the current input/output rotation difference; and signals from the input/output rotation difference detection means and the target rotation difference setting means. 1. A slip control device for a fluid coupling, comprising: correcting means for correcting a target differential pressure set by a target differential pressure setting means based on a deviation between a current input/output rotational difference and a target rotational difference.