JP2807495B2 - Fluid coupling slip control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a slip control device for a fluid coupling such as a torque converter provided in an automatic transmission of a vehicle.

(Prior Art) In recent years, as a torque converter constituting an automatic transmission mounted on a vehicle, an input element to which an engine output is input and an output element driven via a fluid by rotation of the input element are directly connected. A lock-up clutch provided with a lock-up clutch is known. This type of torque converter is, for example, provided that the input element and the output element are directly connected to each other by the lock-up clutch in a predetermined operating region where a torque increasing action, a shift shock absorbing action, and the like are unnecessary. However, when the input element and the output element are directly connected to each other, the engine output shaft and the transmission are mechanically coupled to each other. By the way,
Engine vibrations are more likely to be transmitted to the vehicle body via the transmission, which causes vibration and noise problems.

In order to cope with this, for example, as shown in Japanese Patent Application Laid-Open No. S60-116929, a slip control for slipping an input element and an output element of a torque converter with a predetermined rotation difference in a predetermined operation region is performed. As a result, transmission of the required vibration while preventing transmission of engine vibration to the transmission or the vehicle body is performed.

(Problems to be Solved by the Invention) By the way, as described above, the slip control in which the input element and the output element of the torque converter are slipped in a predetermined operation region to generate a predetermined rotation difference between the two elements,
By detecting the rotational speeds of the input element and the output element, respectively, and performing a feedback control of the engagement force of the lock-up clutch so that the rotational difference between the two elements, that is, the slip amount converges to a preset target value. It is customary to do so.

However, in the case of performing the feedback control of the engagement force of the lock-up clutch during the slip control as described above, the slip amount between the input element and the output element depends on the magnitude of the input torque transmitted to the input element of the torque converter. A response delay occurs until the control value converges to a preset target slip amount, which makes it difficult to quickly perform an appropriate slip control, and compares a control gain in feedback control to eliminate the response delay. If the target slip amount is set to be too large, a hunting phenomenon may occur in which the slip amount between the input and output elements greatly exceeds the preset target slip amount.

Accordingly, the present invention provides a fluid-coupling slip control device that relatively rotates an input element and an output element by a preset target slip amount in a predetermined operation range. Another object of the present invention is to provide a highly responsive slip control device capable of converging a slip amount between the two elements to a preset target slip amount.

(Means for Solving the Problems) In order to solve the above problems, the present invention is characterized in that it is configured as follows.

That is, an input element to which an engine output is input, an output element driven via a fluid by rotation of the input element,
In a slip control device for a fluid coupling, comprising a lock-up means capable of connecting the two elements in a slip state, a hydraulic supply means for supplying an operating oil pressure to the lock-up means, and an input torque transmitted to the input element is detected. And a hydraulic pressure supplied to the lock-up means based on the input torque detected by the torque detecting means, so that the slip amount between the two elements becomes a predetermined target slip amount. Hydraulic setting means for setting;
A slip amount detecting means for detecting an actual slip amount between the two elements; and, when shifting to a preset slip control area, for a predetermined period, an operating oil pressure set by the oil pressure setting means through an oil pressure supply means. The hydraulic pressure is supplied to the lock-up means, and thereafter, the hydraulic pressure is adjusted so as to converge the actual slip amount to the target slip amount according to a deviation between the actual slip amount detected by the slip amount detecting means and a preset target slip amount. Hydraulic control means for adjusting the operating hydraulic pressure supplied to the lock-up means via the supply means.

The predetermined period may be a period until the actual slip amount reaches a predetermined range with respect to the target slip amount, or a case where a predetermined time has elapsed since the shift to the slip control region.

(Operation) According to the above configuration, at the time of shifting to the preset slip control region, the hydraulic control means performs a predetermined period between the input and output elements based on the input torque detected by the input torque detection means. The operating oil pressure set by the oil pressure setting means is supplied to the lock-up means via the oil pressure supply means so that the slip amount becomes the preset target slip amount, and the slip amount between the two elements Can be quickly approached to the target slip amount, and thereafter, through the hydraulic pressure supply means according to the deviation between the actual slip amount between the two elements and the target slip amount detected by the slip amount detection means. By adjusting the operating oil pressure supplied to the lock-up means, the actual slip amount immediately converges to the target slip amount.
As a result, the input element and the output element can be relatively rotated by the target slip amount with good responsiveness and without causing the hunting phenomenon, and the slip control can be performed very well.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

First, a schematic configuration of a power plant of a vehicle to which the present invention is applied and a control system thereof will be described with reference to FIG.
The power plant includes an engine 10 and an automatic transmission 20. The engine 10 includes an intake system 11 for supplying intake air to a combustion chamber, a fuel system (not shown) for supplying fuel, and exhaust gas generated in the combustion chamber. An exhaust system (not shown) for discharging gas is provided, and the intake system 11 is provided with a throttle valve 12 for controlling an intake air amount.

On the other hand, the automatic transmission 20 reduces the output of the torque converter 30 connected to the output shaft of the engine 10 and the output of the torque converter 30 at a speed ratio selected by switching the power transmission path. (Not shown), and a hydraulic control unit 50 for selectively engaging a plurality of frictional engagement elements provided on the transmission gear mechanism 40 and switching the power transmission path. I have.

The torque converter 30, as described in detail below,
It has a pump as an input element coupled to the output shaft of the engine 10, a turbine as an output element to the transmission gear mechanism 40 side, and a lock-up clutch for mechanically coupling these components. A converter state for transmitting power from the pump to the turbine via a fluid, a clutch is fastened, a lock-up state for directly connecting the pump and the turbine, and the clutch is further slipped,
It is possible to switch between a slip state in which the pump and the turbine are relatively rotated by a required slip amount.

The hydraulic control unit 50 has five solenoid valves 51... 51 for speed change control, and first and second solenoid valves 52 and 53 for lock-up control. And these solenoid valves 51 ... 51, 52, 53
Is provided with a controller 60 for controlling the operation of.

The control 60, the signals S ₁ from the throttle opening sensor 61 for detecting an opening degree of the throttle valve 12 in the engine 10, the signal S ₂ from the vehicle speed sensor 62 for detecting a vehicle speed of the vehicle, engine 10 the signal S ₃ from the engine speed sensor 63 for detecting a rotational speed of a signal S ₄ from the turbine speed sensor 64 for detecting the rotational speed of the turbine in the torque converter 30, detects the operation position of a shift lever Signal S ₅ from shift position sensor 65
And a signal S ₆ from an accelerator sensor 66 for detecting the amount of depression of the accelerator pedal, a signal S ₇ from an oil temperature sensor 67 for detecting the temperature of hydraulic oil supplied to the automatic transmission 20, and a depression of the brake pedal. the signal S ₈ from a brake sensor 68 for detecting an amount, other various signals S _x required for the control are input, respectively. The controller 60 controls the solenoid valves according to the operation state indicated by the signals.
The transmission control signals S ₉ ... S ₉ and the lock-up control signals S ₁₀ and S ₁₁ are output to 51... 51, 52, and 53, respectively, to change the power transmission path of the transmission gear mechanism 40. The lock-up control of the torque converter 30, that is, switching to the converter state, the lock-up state and the slip state, and each control for adjusting the slip amount in the slip state are performed.

Here, the shift control and the lock-up control will be briefly described. The controller 60 includes a shift pattern preset using the throttle opening and the vehicle speed as parameters as shown in FIG. 3, and a throttle pattern shown in FIG. Opening sensor
61 and compared with the actual state of operation represented by the detected throttle opening and the vehicle speed by the vehicle speed sensor 62, the shift-up line U ₁ ~ constituting the operating state shift pattern
U ₃ is shifted up shift speed when traversed the high vehicle speed side, and as to shift down the gear position when the across each downshift line D ₁ to D ₃ in the low vehicle speed side, for the shift and it outputs a shift control signal S ₉ to the solenoid valve 51 ... 51. In addition, the controller 60, as shown in FIG.
Similarly, the lock-up pattern in which the lock-up area L and the slip control area S are set in advance using the throttle opening and the vehicle speed as parameters is compared with the driving state indicated by the actual throttle opening and the vehicle speed. When the torque converter 30 belongs to the region L or the slip control region S, the torque converter 30 is set to the lock-up state or the slip state, and the converter region C other than these regions L and S is set to the converter state. Control signal to the first solenoid valve 52
And it outputs the S _10. In particular, in the slip control region S, the second solenoid valve is controlled so that the pump and the turbine of the torque converter 30 rotate relatively with a required slip amount.
Control signal for adjusting lockup clutch engagement force to 53
And it outputs the S _11. Note that the lock-up area L is 3
The execution lines Lj and Sj for the lock-up state or the slip state are provided corresponding to the shift-up line U and the shift-down line D shown in FIG. Release lines Lk and Sk are set to release. The throttle opening sensor 61 detects the fully closed state of the throttle valve 12 and the deceleration slip control is performed during a deceleration state in which the engine speed detected by the engine speed sensor 63 is larger than a predetermined value. It has become.

Next, the configuration of the torque converter 30 and the configuration of a hydraulic circuit of a portion related to lock-up control in the hydraulic control unit 50 will be described with reference to FIG.

First, a torque converter 30 includes a pump 32 fixed inside a case 31 and a turbine 33 rotatably supported in the case 31 so as to face the pump 32.
And a stator 34 interposed between the pump 32 and the turbine 33. The case 31 is connected to the engine output shaft 13 so that the case 31 and the pump 32
And the turbine 33 is driven by the rotation of the pump 32 via the hydraulic oil in the case 31, and
When the ratio of the turbine rotation speed to the pump rotation speed at that time is equal to or less than a predetermined value, the torque transmitted from the pump 32 to the turbine 33 is increased by the action of the stator. The rotation of the turbine 33 is output to the transmission gear mechanism 40 (see FIG. 2) via the turbine shaft 35.

The torque converter 30 includes the turbine 33
A lock-up clutch 36 is provided on the back of the case 31 so as to face the inner end surface 31a of the case 31. The lock-up clutch 36 is biased toward the case inner end face 31a by the oil pressure of the internal pressure chamber 37 inside the case 31, and connects the pump 32 and the turbine 33 when fastened to the face 31a. This allows
The engine output shaft 13 and the turbine shaft 35 are mechanically connected, and the torque converter 30 enters a lockup state. The lock-up clutch 36 has an operating pressure (release pressure) in a release chamber 38 provided between the lock-up clutch 36 and the case inner end surface 31a.
Is supplied, the turbine 33 is separated from the inner end face 31a and the turbine 33 is driven via the fluid, whereby the torque converter 30 enters a converter state in which the torque is increased. Further, the lock-up clutch 36 slips with respect to the case inner end surface 31a when the fastening force on the case inner end surface 31a is reduced due to the adjustment of the release pressure, whereby the torque converter 30 disconnects the turbine 33 and the pump 32 from each other. A slip state occurs in which a relative rotation is performed by a predetermined slip amount.

On the other hand, a hydraulic circuit 70 related to lock-up control in the hydraulic control unit 50 adjusts the release pressure in a slip state with a lock-up shift valve (hereinafter, referred to as a shift valve) 71 that switches between the above states. A lock-up pressure regulating valve (hereinafter referred to as a pressure regulating valve) 76, and these valves 71, 76 are driven through the operation of the first and second solenoid valves 52, 53 for lock-up control. It has become.

The shift valve 71 includes a first spool 72 disposed on the right side in the drawing, a second spool 73 disposed on the left side,
A spring 74 is disposed on the left side of the second spool 73 and biases both spools 72, 73 to the right. The right end of the first spool 72 has a large-diameter pressure receiving land.
72a is provided. Further, a first control port a is provided at the right end of the shift valve 71, a second control port b is provided at the left end, and a third control port is provided at a portion of the intermediate portion opposed to the first and second spools 72 and 73. c are provided respectively.
The first control port a has a first control line 82 directly led from the discharge side of the oil pump 81, and the second control port b has a constant pressure forming part 83 also from the discharge side of the oil pump 81. A second control line 84 led through the
A third control line 85 branched from an upstream portion of the second control line 84 is connected to the control port c, and drain ports 82a, 84a are connected to the first and second control lines 82, 84, respectively. The first solenoid valve 52 and the second solenoid valve 53 for lock-up control described above are arranged in these ports 82a and 84a, respectively.

Here, the first solenoid valve 52 is connected to the controller 60.
ON by the control signal S ₁₀ from, is turned OFF, open the ON at the drain port 82a, OFF during closing the port 82a.
Further, the second solenoid valve 53 is turned on in a very short cycle,
A duty solenoid valve that repeats OFFT,
Drain port 84a in accordance with the control signal S ₁₁ is duty ratio indicated from the controller 60 (the ratio of the ON time in one cycle)
, The control pressure in the second control line 84 is adjusted to a lower pressure as the duty ratio increases.

On the other hand, the pressure regulating valve 76 includes a spool 77 and a spring 78 that is disposed on the left side of the spool 77 in the drawing and urges the spool 77 to the right side, and is branched from the second control line 84. A line 86 is connected to a first control port d provided at the right end of the valve 76, and a throttle pressure line 88 led from a throttle pressure forming part 87 is connected to the valve 76.
76 are connected to second control ports e provided at the left end. Here, the throttle pressure forming section 87
It is connected to a main line 90 led from a regulator valve 89 for adjusting the discharge pressure of the oil pump 81 to a predetermined line pressure, and adjusts the line pressure to a throttle pressure corresponding to the throttle opening of the engine.

An input port f to which the main line 90 is connected and a shift valve 71 are provided at the center of the pressure regulating valve 76.
An oil pressure adjusting unit is provided by arranging an output port g connected to a relay line 91 leading to the drain port h adjacent to the output port g. Then, the control pressure in the second control line 84 to the line 86 adjusted according to the duty ratio of the second solenoid valve 53 and the throttle pressure are introduced into the first and second control ports d and e, respectively. Accordingly, in the pressure regulating valve 76, the spool 77 is displaced left and right due to the force relationship between these pressures and the urging force of the spring 78, and as the spool 77 displaces rightward from the position shown in FIG. As the control pressure in one control port d decreases, the line pressure introduced into the input port f is adjusted to a lower pressure and supplied from the output port g to the shift valve 71 side.

Here, the lock-up control operation of the hydraulic circuit 70 will be described. First, when the first solenoid valve 52 is OFF and the duty ratio of the second solenoid valve 53 is 0, the first and second control lines 82, 84, the drain ports 82a, 84a are closed, and the first and second control ports a,
A control pressure is introduced into the pressure control valve b and the first control port d of the pressure regulating valve 76. At this time, in the shift valve 71, the control pressure in the first control port a acting on the large-diameter pressure receiving land 72a of the first spool 72 overcomes the control pressure in the second control port b and the urging force of the spring 74. Therefore, the first and second
The spools 72 and 73 are located on the left side as shown. Therefore, the lock-up release chamber 38 in the torque converter 30
A release line 92 communicating with the pressure regulator valve 76 communicates with a relay line 91, and the internal pressure chamber 37 of the torque converter 30.
Is connected to an oil cooler 95 having a drain action via a line 94. Also, pressure regulating valve 76
In this case, a large control pressure is introduced into the first control port d, and the spool 77 of the valve 76 is located at the leftmost position as shown in the figure, so that the line pressure from the main line 90 is input without being reduced. The fluid is discharged from the port f to the output port g, and is introduced as a release pressure from the release line 92 to the lock-up release chamber 38 of the torque converter 30 via the relay line 91 and the shift valve 71. As a result, the lock-up clutch 36 is released, and the torque converter 30 enters the converter state.

When the first solenoid valve 52 is turned on, the first solenoid valve 52 is turned on.
When the drain port 82a of the control line 82 is opened and the duty ratio of the second solenoid valve 53 is 0, the second control line
When the drain port 84a of the valve 84 is closed, in the shift valve 71, the first and second spools 72, 72 are controlled by the control pressure and the spring 74 introduced into the second control port b.
73 moves to the right. At this time, the lock-up clutch 36 is engaged by connecting the engagement line 93 to the main line 90 and the release line 92 to the drain port of the shift valve 71, and the torque converter 30
Is locked up.

Further, when the first solenoid valve 52 is ON, the first control line
When the drain port 82a of 82 is opened and the duty ratio of the second solenoid valve 53 is equal to or higher than a predetermined value (for example, 20%), and the control pressure in the second control line 84 is reduced to a predetermined value or lower. In the shift valve 71, the control pressure introduced from the third control line 85 to the third control port c is equal to the second control pressure.
By overcoming the control pressure in the control port b and the biasing force of the spring 74, the second spool 73 is located on the left side, and the first spool 72 is located on the right side by the control pressure in the third control port c. Become. At this time, the main line 90 is connected to the fastening line 93 and the relay line 91 from the pressure regulating valve 76.
Communicates with the release lines 92, respectively, and the line pressure is introduced into the internal pressure chamber 37 of the torque converter 30. At the same time, the release pressure adjusted by the pressure regulating valve 76 in accordance with the duty ratio of the second solenoid valve 53 decreases. Open room of converter 30
38 will be introduced. Therefore, the lock-up clutch 36 slips due to a decrease in the engagement force by the release pressure as compared with the lock-up state described above, whereby the torque converter enters the slip state. In this case, since the release pressure decreases as the duty ratio of the second solenoid valve 53 increases, the slip amount of the torque converter 30 decreases as the duty ratio increases.

In FIG. 5, a line 96 is a line for guiding the operating oil, which has become high temperature in the torque converter 30, to the oil cooler 95 via the pressure holding valve 97.

Next, the operation of this embodiment will be described with reference to FIGS.

First, the main program of the control operation of the lock-up clutch 36 by the controller 60 will be described with reference to the flowchart shown in FIG.
Reads various detection signals in step P _1, Step P ₂
In, it is determined whether the steady-state slip control condition is satisfied, and when it is determined that the steady-state slip condition is satisfied,
In Step P _3, it determines whether the shift operation is being performed. When the shift operation is determined not to take place, the lock-up operating condition is determined whether a condition is satisfied in the step P _4, when the lock-up operating condition is determined not to be satisfied, Step P _{At 5} , the steady slip control is executed. The steady slip control will be described later in detail with reference to FIG.

Further, in step P _3, when it is determined that during the shifting operation, the shifting operation is determined whether the upshifting in step P _6, if during shift-up operation, in step P _7, Execute the speed change slip control. This shift slip control will be described later.
This will be described in detail with reference to FIG.

On the other hand, in step P _2, when the steady slip control condition is determined not to be satisfied, it is determined whether the deceleration slip control condition is satisfied in the step P _8. When the deceleration slip control condition is determined not to be satisfied, in step P _9, when it is determined whether or not during shifting operation, it is determined that the shift operation is not performed,
Lock-up operating condition is determined whether a condition is satisfied in the step P _10, if it is determined that the condition is not satisfied,
In step P _11, it stops the output of the control signal S ₁₀ to the first solenoid valve 52 stops outputting the control signal S ₁₁ to the second solenoid valve 53 in step P _12. As a result, the hydraulic pressure is not supplied to either the internal pressure chamber 37 or the release chamber 38, and the lock-up clutch 36
Is released.

Further, in step P _10, when the lock-up operating condition is determined to be satisfied, with the step P ₁₃ is the control signal S ₁₀ to the first solenoid valve 52 is output, in step P _14, the first 2 solenoid valves 5
It stops outputting the control signal S ₁₁ to 3. Accordingly, the operating oil pressure is supplied to the internal pressure chamber 37 of the lock-up clutch 36, and a lock-up state is established in which the pump 32 and the turbine 33 are directly connected by the lock-up clutch.

Further, in step P _4, when determining that the lock-up operating condition is satisfied, it executes step P ₁₃ and S P _14. Further, in step P _9, when it is determined that during the shift operation, performs a step P _6, when the shift operation in the step P ₆ determines that a shift-up operation, as in step P ₇ is executed, and also, when it is determined not during a shift-up operation in step P _6, the step P _11, returns to the original running step P _12.

Further, in step P _8, when the deceleration slip control condition is determined to be satisfied, in step P _15, when determining whether the brake pedal is depressed, it is determined that the brake pedal is depressed, in step P _16, a third throttle opening degree of the speed change line D ₃ in the shift pattern shown in FIG. is 0 state, i.e., to shift the vehicle speed value of the case where the throttle valve 12 is fully closed at a high vehicle speed side to change the 4-3 downshift condition Te, then in step P _17,
If it is determined that the speed change operation has not been performed, deceleration slip control is executed in step ₁₈ . The deceleration slip control will be described later in detail with reference to FIG.

Further, in step P _17, when it is determined that the system is in gear shift operation, in step P ₁₉ shift operation 4-
3 it is judged whether or not the a downshift, 4-3 when it is during the shift down operation executes step P _7, also in the step P _19, determined to be not in 4-3 shift down operation when you performs step P _6, based on the determination result in the step P _6, subsequent steps P ₇ or step P _11, executes step P _12.

The operation of the lock-up clutch 36 depends on whether the downshift condition from the third speed to the second speed or from the second speed to the first speed is satisfied, and when the downshift condition from the fourth speed to the third speed is satisfied. The control is performed such that the states are different when the downshift operation from the third speed to the second speed or from the second speed to the first speed is performed under the condition that the deceleration slip control condition is satisfied. Since the vehicle speed is assumed to be a very low value, the value of the engine speed becomes lower than the value at which the fuel is returned, and the engine is not in the fuel cut state, whereas the fourth speed This is because, when the downshift operation from the third gear to the third gear is performed, the value of the engine speed becomes larger than the value at the time of the fuel return, and the engine is in a state where the fuel cut is performed.

Next, the steady slip control will be described with reference to the flowchart shown in FIG.

First, the controller 60 in step P _21, it is determined whether the constant slip control starting point, when it is determined that the constant slip control starting time, in step P _22, the detection signals S ₁ of the throttle sensor 61 based on the engine rotational speed indicated by the detection signal S ₃ of the throttle opening and the engine speed sensor 63 shown is, as shown in FIG. 8, the engine torque the throttle opening as a parameter
The engine torque Te is set by reading from a map indicating the relationship between Te and the engine speed Ne. Incidentally, a ₁ ~a ₆ in the map that opening the throttle opening with respect to the fully closed is set to 1 / 8,2 / 8,3 / 8,4 / 8,5 / 8,6 / 8 Each state is shown. Then, in step P _23, oil temperature sensor 6
Setting the correction factor K based on 7 temperature of the hydraulic oil is detected signal S ₇ indicates the. For example, the value of the correction coefficient K is set to 1 when the operating oil temperature is 90 ° C., set to a larger value as the operating oil temperature becomes higher than 90 ° C., and set to a smaller value as the operating oil temperature becomes lower than 90 ° C. . Then, after setting a predetermined correction coefficient K in this way, in step P _24, a target transmission torque Tr, wherein: based set by Tr = Te × K, then, in step P _25, target transmission torque Tr In order to obtain the rotation difference ΔN, the differential pressure ΔP of the working oil pressure supplied to the internal pressure chamber 37 and the release chamber 38 is set. In this case, as shown in FIG. 9, for example, the input torque Ti and the rotation difference ΔN input to the pump 32 of the torque converter 30 using the respective differential pressures ΔP as parameters while the operating oil temperature is 90 ° C. ΔP is set based on a map indicating the relationship with. After thus setting the [Delta] P, at step P _26,
The duty ratio Yn that causes the above ΔP is determined based on a map showing the relationship between the throttle opening Th and the differential pressure ΔP as shown in FIG. Then, in step P _27, and the duty ratio D determined by the step P ₂₆ Yn
Set outputs a control signal S ₁₀ to the first solenoid valve 52 in step P _28, the duty ratio D which is set in the step P ₂₇ in step P ₂₉
The control signal S ₁₁ having the output to the second solenoid valve 53. As a result, the slip amount between the pump 32 and the turbine 33 can be brought closer to the target slip amount immediately after the steady-state slip control.

On the other hand, in step P _21, if it is determined not to be normal slip control starting time, and executes step P _30, the actual slip amount indicated by the difference between the engine speed and the turbine speed at that time preset It is determined whether or not the target slip amount is within a predetermined range.
When it is determined not to have reached the predetermined range, performs feed-forward control continues with step P ₂₉ from step P ₂₂ as described above. Step P ₃₀
In, when it is determined to have reached within the predetermined range, performs the step P _31, and calculates a deviation ΔNn to the target slip amount of the actual slip amount indicated by the difference between the engine speed and the turbine speed at that time and then, in a step P _32, based on DerutaNn calculated this time and .DELTA.N _n-1 and the previously calculated, the formula: Z = a × ΔNn + B × ΔN n-1 by the correction factor Z
Calculates, on the basis of the correction factor Z, from the map shown in FIG. 11 in step P _33, obtains a correction amount ΔX of the duty ratio, in step P _34, wherein the value of the current duty ratio Yn: Yn = determined by Y _n-1 + ΔX, and executes step P ₂₉ from step P ₂₇ as described above. As a result, when the actual slip amount is larger than the target value, the duty ratio D is increased, and the pressure regulating valve 76 shown in FIG.
When the converter release pressure is adjusted to be lower, the engagement force of the lock-up clutch 36 is increased and the slip amount is reduced. When the slip amount is smaller than the target value, the duty ratio D is reduced. By increasing the release pressure, the slip amount increases, and thus the actual slip amount quickly converges to the preset target slip amount.

Next, based on the flowchart shown in FIG. 12, referring to the shift slip control operation by the controller 60, the controller 60 in step P _41, it is determined whether or not the shift slip control starting time, transmission slip If it is determined that the control has started, step P
_{At 42} , it is determined whether or not the lock-up clutch 36 is in a slip state. Then, when it is determined that the slip state, in step P _43, with the duty ratio D is set to a value Y _n-1 previously set, and outputs a control signal S ₁₀ to the first solenoid valve 52 in step P ₄₄ in step P _45, a control signal S ₁₁ a second solenoid valve 53 with a duty ratio D which is set in the step P ₄₃
Output to

On the other hand, the lock-up clutch 36 in step P ₁₄ is when it is determined that no slip state, a step P ₄₉ from step P _46, executes steps P ₂₂ in the flowchart shown in FIG. 7 as in step P _25.
Then, determine the value of the duty ratio Yn that can cause the pressure difference ΔP at the step P _50, sets the value of the duty ratio D to Yn in step P _51, a control signal S ₁₀ in step P ₅₂ to the first solenoid valve 52 outputs a control signal S ₁₁ having a duty ratio D which is set in step P ₅₁ in step P ₅₃ the second solenoid valve 53
Output to Note that the value of the differential pressure ΔP in the shift slip control is obtained in the same manner as in the case of the steady slip control shown in FIG. 7, but is smaller than the value of the differential pressure ΔP obtained in the steady slip control. .

Next, the deceleration slip control will be described based on a flowchart shown in FIG.

First, the controller 60 in step P _61, it is determined whether the deceleration slip control starting point, when it is determined that the deceleration slip control starting time, sets the engine torque Te 'in step P _62. In this case, since the torque is transmitted from the wheel side to the engine side, the torque transmitted from the wheel side to the engine side in accordance with the engine speed previously obtained by an experiment or the like and stored in the controller 60 ( Hereinafter, referred to as resistance torque)
Ask for. The resistance torque Te 'has a characteristic that increases in proportion to the square of the engine speed, for example. Thereafter, in step P _63, sets the correction coefficient K based on the temperature of the hydraulic oil detected by the detection signal S _7. The value of the correction coefficient K is, for example, 90
In the case of ° C., it is set to 1, set to a larger value as the temperature becomes higher than 90 ° C., and set to a smaller value as the temperature becomes lower than 90 ° C. Then, after thus setting a predetermined correction coefficient K, in step P _64, 'the formula: Tr' target transmission torque Tr set by = Te '× K, then, in step P _65, target transmission torque The pressure difference ΔP for obtaining the rotation difference ΔN based on Tr ′ is set based on the map shown in FIG. Thus Δ
After setting the P, in step P _66, the duty ratio Yn that can cause the [Delta] P, determined in accordance with the map shown in FIG. 10, in step P _67, the duty ratio D determined by the step P ₆₆ set Yn, and outputs a control signal S ₁₀ in step P ₆₈ to the first solenoid valve 52, a control signal S ₁₁ having a duty ratio D which is set in the step P ₆₇ in step P ₆₉ the second solenoid valve Output to 53. As a result, the slip amount of the pump 32 and the turbine 33 can be quickly brought closer to the target slip amount after the deceleration slip control.

On the other hand, in step P _61, if it is determined not to be the deceleration slip control starting time, and executes step P _70, whether the actual slip amount is within a predetermined range with respect to the slip amount of the target judge. When it is determined not to have reached the predetermined range, performs feed-forward control continues with step P ₆₉ from step P ₆₂ as described above. If it is determined in step _P70 that the actual slip amount has reached the predetermined range corresponding to the target slip amount, step _P71 is executed, and the engine speed and turbine speed at that time are determined. based on the difference between the actual calculated slip amount deviation ΔNn to the target slip amount, then in step P _72, wherein: Z = a × ΔN
calculating a correction factor Z by _{n + B × ΔN n-1} , on the basis of the correction factor Z, from the map shown in FIG. 11 in step P _73, sets the correction value [Delta] X. Then, in step P _74, wherein the value of the duty ratio D: Yn = determined by Y _n-1 + ΔX, executes steps P ₇₇ Step P ₇₉ in the same manner as described above. Thus, when the actual slip amount is within a predetermined range with respect to the target slip amount, the actual slip amount quickly converges to a preset target slip amount.

In the present embodiment, at the time of steady-state slip control or deceleration slip control, it is determined whether the actual slip amount is within a predetermined range with respect to the target slip amount,
When the actual slip amount is within a predetermined range, the process shifts to feedback control.
After the start of each slip control, the control may shift to the feedback control when a predetermined time has elapsed.

(Effects of the Invention) As described above, according to the slip control device for a fluid coupling according to the present invention, when shifting to the preset slip control region, the slip is detected by the hydraulic control means for a predetermined period by the input torque detecting means. Based on the input torque, the operating oil pressure set by the oil pressure setting means is supplied to the lock-up means via the oil pressure supply means so that the slip amount between the input and output elements becomes the predetermined target slip amount. As a result, the slip amount between the two elements can be quickly brought close to the target slip amount, and thereafter, the actual slip amount between the two elements and the target slip amount detected by the slip amount detecting means. By adjusting the operating oil pressure supplied to the lock-up means via the oil pressure supply means in accordance with the deviation from It converges on the slip amount. As a result, the input element and the output element can be rotated by the target slip amount with good responsiveness and without causing the hunting phenomenon, and the slip control can be performed extremely well.

[Brief description of the drawings]

FIG. 1 is a schematic structural view showing a slip control device for a fluid coupling according to the present invention in accordance with the claims, and FIGS.
Fig. 2 shows an embodiment of the present invention. Fig. 2 is a control system diagram of an automatic transmission, Fig. 3 is a map used in shift control, Fig. 4 is a map used in lock-up control and slip control, FIG. 5 is a schematic configuration diagram showing a structure of a torque converter and a hydraulic circuit for controlling the operation of a lock-up clutch in the torque converter, FIG. 6 is a flowchart showing a main program of a controller, and FIG. FIGS. 8 to 10 are characteristic diagrams used for slip control, respectively, FIG. 11 is a characteristic diagram of a feedback correction amount used in slip control, FIG. 12 is a flowchart diagram showing a shift slip control operation, FIG. 13 is a flowchart showing the deceleration slip control operation. 30 ... fluid coupling (torque converter), 32 ... input element (pump), 33 ... output element (turbine), 36 ... lock-up means (lock-up clutch), 60 ... torque detection means, slip amount detection Means, hydraulic control means (controller), 71 ... hydraulic supply means (lock-up shift valve), 76 ... hydraulic setting means (lock-up pressure regulating valve).

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-143265 (JP, A) JP-A-62-270864 (JP, A) JP-A-1-1102072 (JP, A) JP-A-1- 141273 (JP, A) JP-A-60-1461 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 61/14

Claims (1)

(57) [Claims] 1. A fluid coupling comprising: an input element to which an engine output is input; an output element driven via fluid by rotation of the input element; and a lock-up means capable of connecting the two elements in a slip state. A hydraulic supply means for supplying an operating oil pressure to the lock-up means, a torque detecting means for detecting an input torque transmitted to the input element, and an input torque detected by the torque detecting means. Hydraulic pressure setting means for setting the operating oil pressure supplied to the lock-up means such that the slip amount between the two elements becomes a target slip amount set in advance, and the actual slip amount between the two elements. And a hydraulic pressure set by the hydraulic pressure setting means for a predetermined period when shifting to a preset slip control area. The slip amount is supplied to the lock-up means via the feeding means, and thereafter, the actual slip amount is converged on the target slip amount in accordance with a deviation between the actual slip amount detected by the slip amount detecting means and a preset target slip amount. And a hydraulic control means for adjusting the operating hydraulic pressure supplied to the lock-up means via the hydraulic pressure supply means.