JP2576733B2 - Slip control device for vehicle direct coupling clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip control device for a vehicle direct coupling clutch.

[0002]

2. Description of the Related Art In an automatic transmission for a vehicle equipped with a fluid transmission having a direct coupling clutch such as a torque converter with a lock-up clutch or a fluid coupling with a lock-up clutch, for example, the throttle valve has an idle opening degree. There is a slip control in which the direct-coupled clutch is half-engaged so that the transmitted torque becomes a value corresponding to the rotation speed of the engine when the decelerated running is performed. A slip control device that executes slip control by feedback control and feedforward control as a kind of the slip control has been proposed. For example, Japanese Unexamined Patent Publication No.
This is the slip control device described in Japanese Patent Publication No. In the slip control, an input torque of the hydraulic power transmission, a rotation speed difference between the input side rotation speed and the output side rotation speed are detected, and a target rotation speed difference is set based on the input torque and the rotation speed difference. The differential pressure control means controls the differential pressure of the direct coupling clutch so that the target differential pressure corresponds to the target rotational speed difference. At the same time, a difference between the current rotation speed difference and the target rotation speed difference is obtained, and based on the difference, the target rotation speed difference targeted by the differential pressure control unit is corrected by the correction unit. When the deviation increases in accordance with the change in the input torque, the increase / decrease correction amount of the target rotational speed difference is increased to improve the responsiveness of the control, while when the deviation decreases, the initial target rotational speed difference is set. Thus, the convergence of the control is improved. That is, in the above-described slip control device, feedback control for controlling a differential pressure so as to obtain a target rotation speed difference and feedforward control for correcting the target rotation speed difference to increase or decrease in accordance with a change in input torque are substantially performed. Is executed.

[0003]

By the way, at the start of the above-mentioned conventional slip control device, the state shifts from the acceleration running state to the decelerating running state, so that the input shaft rotation speed of the hydraulic power transmission device rapidly decreases. However, if the slip control output is too small, the engine speed falls below the target slip amount and the fuel cut period is shortened, while if the slip control output is too large, the engine speed and turbine speed are reduced. And the inconvenience of generating a shock occurs. In addition, when the vehicle is running at a reduced speed, a delicate control output value is required because the output torque of the engine is small. For this reason, it is necessary to output an appropriate feedforward value.However, in the feedforward control of the above-described conventional slip control device, only the increase / decrease correction is performed according to the change in the input torque. There was a drawback that slip control could not be properly obtained due to the influence of aging. It is also conceivable to control the target slip amount by feedback control without relying on feedforward control, but an undershoot occurs due to a delay in the feedback system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a direct coupling for a vehicle in which the slip control of the direct coupling clutch can be appropriately obtained regardless of the individual difference of the direct coupling clutch or its aging. An object of the present invention is to provide a clutch slip control device.

[0005]

To achieve the above object, the gist of the first invention is to provide a power transmission path from an engine to driving wheels as shown in the gist diagram of FIG. In a vehicle having an interposed fluid transmission with a direct-coupled clutch, in a deceleration running state in which the throttle valve is at an idle opening, the direct-coupled clutch includes a feedforward correction term according to a previously stored control formula. (A) an engine speed detecting means for detecting an engine speed, and (b) a start of decreasing the engine speed at the start of the slip control. From that engine times
(C) an engine rotation speed decrease width determining means for determining the decrease amount of the engine rotation speed up to the minimum point of the rotation speed; and (c) the control expression so that the decrease amount of the engine rotation speed becomes a predetermined target decrease width . Controllable correction means for correcting the feedforward term . Further, the gist of the second invention is that in a vehicle having a fluid transmission with a direct coupling clutch inserted in a power transmission path from an engine to a drive wheel, in a deceleration running in which a throttle valve is an idle opening degree. Is a slip control device provided with slip control means for performing slip control of the direct-coupled clutch in accordance with a control formula stored in advance including a feedforward correction term , wherein (a) an engine speed for detecting an engine speed. Speed detection means, and (b) the start condition of the slip control is satisfied.
(C) an engine speed reduction width determining means for determining a reduction amount of the engine rotation speed until after a predetermined time has elapsed , and (c) the control expression so that the reduction amount of the engine rotation speed becomes a predetermined target reduction width . Controllable correction means for correcting the feedforward term .

[0006]

[0007]

According to the first and second aspects of the present invention,
Slip control by means of engine speed reduction range determination means
To the minimum point of the engine speed that drops at the start of
Of engine speed decrease and start condition of slip control
Decrease in engine speed from the establishment until a predetermined time has elapsed
The width is determined, and the control formula correction means
The amount of decrease in engine speed that occurs at the start
The slip control means is set so as to have a predetermined target decrease width.
The feed-forward term of the control formula used in the stage has been corrected.
It is. Therefore, according to the first or second aspect of the present invention, the control formula is modified according to the individual difference and the aging of the direct coupling clutch, so that the appropriate slip control can be performed regardless of the individual difference and the aging of the direct coupling clutch. can get.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a diagram showing a vehicle power transmission device to which an embodiment of the present invention is applied. In the figure, the power of an engine 10 is transmitted to drive wheels via a torque converter 12 with a lock-up clutch 12, a stepped automatic transmission 14 composed of three sets of planetary gear units, and a differential gear device (not shown). It has become so.

The above-mentioned torque converter 12 is used for the engine 1
Pump wheel 18 connected to crankshaft 16
And a turbine wheel 22 fixed to the input shaft 20 of the automatic transmission 14 and rotated by receiving oil from the pump wheel 18, and fixed to a housing 26 which is a non-rotating member via a one-way clutch 24. Stator wheel 28
And a lock-up clutch 32 connected to the input shaft 20 via a damper 30. When the oil pressure in the release-side oil chamber 33 is higher than that in the engagement-side oil chamber 35 in the torque converter 12, the lock-up clutch 32 is disengaged. Torque is transmitted at a corresponding amplification factor. However, when the oil pressure in the engagement side oil chamber 35 is higher than that in the release side oil chamber 33, the lock-up clutch 32 is engaged, so that the input / output member of the torque converter 12, that is, the crankshaft 16 and the input The shaft 20 is directly connected.

The automatic transmission 14 includes the input shaft 20 and the output shaft 34, and one of a plurality of forward gears and a reverse gear is provided by a combination of operations of a plurality of hydraulic friction engagement devices. It is configured as a well-known stepped planetary gear set that can be selectively established. And
A shift control hydraulic control circuit 44 for controlling the gear position of the automatic transmission 14 and an engagement control hydraulic control circuit 46 for controlling engagement of the lock-up clutch 32 are provided. The shift control hydraulic control circuit 44 includes solenoid No. 1 and solenoid No. 2 as well known.
A first solenoid valve 48 and a second solenoid valve 50 which are respectively turned on and off by the first solenoid valve 4.
The clutch and the brake are selectively operated by a combination of the operations of the eighth and second solenoid valves 50, so that any one of the first to fourth gear stages is established.

The engagement control hydraulic control circuit 46 includes a linear solenoid valve 52 which is operated by a solenoid No. 3 which is a linear solenoid, a release position where the lockup clutch 32 is released, and a lockup clutch 32. And a regulator pressure P _cl generated by a clutch pressure regulator (not shown) in the shift control hydraulic control circuit 44 in accordance with the throttle valve opening. And a slip control valve 56 for controlling the source pressure. The linear solenoid valve 52 uses a constant modulator pressure P _modu generated in the shift control hydraulic control circuit 44 as a _source pressure, and uses a drive current I _sol from an electronic control unit (ECT) 42.
_Is continuously generated, and this output pressure P _lin is caused to act on the switching valve 54 and the slip control valve 56.

The switching valve 54 includes a spring 58 for urging a spool valve (not shown) toward a release side position,
The first port 60 to which the regulator pressure P _cl is supplied
A second port 62 to which the output pressure of the slip control valve 56 is supplied, and a third port 64 connected to the release-side oil chamber 33.
And a fourth port 66 connected to the engagement side oil chamber 35 and a fifth port 68 connected to the drain. When the output pressure P _lin of the linear solenoid valve 52 supplied to the switching valve 54 falls below a predetermined constant value, the spool valve element is positioned at the release side position according to the biasing force of the spring 58. , The second port 62 is closed, and the first port 60 and the third port 64 and the fourth port 66 and the fifth port 68 are communicated with each other. Therefore, when the output pressure P _lin of the linear solenoid valve 52 applied to the spool valve of the switching valve 54 falls below a predetermined value, the spool valve of the switching valve 54 is released according to the biasing force of the spring 58. And the hydraulic pressure P _off in the disengagement oil chamber 33 is set to the regulator pressure P _cl and the hydraulic pressure P _on in the engagement side oil chamber 35 is set to the atmospheric pressure. To be released. However, when the output pressure P _lin of the linear solenoid valve 52 applied to the spool valve of the switching valve 54 exceeds a predetermined value, the spool valve of the switching valve 54 resists the urging force of the spring 58. And the fifth port 68 is closed, and the first port 60 and the fourth port 66 and the second port 62 and the third port 64 are communicated with each other. For this reason, the hydraulic pressure P _on in the engagement side oil chamber 35 is set to the regulator pressure P _cl, and at the same time, the hydraulic pressure P _off in the release side oil chamber 33 is pressure-controlled by the slip control valve 56 so that the lock-up clutch 32
Is slip controlled or released.

The slip control valve 56 has a spring 70 for urging a spool valve (not shown) to increase the output pressure. In order to generate a thrust toward the output pressure increasing side, a hydraulic pressure P _on in the engagement side oil chamber 35 is applied to the spool valve element, and to generate a thrust toward the output pressure decreasing side. The hydraulic pressure P _off in the release side oil chamber 33 and the output pressure P _{lin of the} linear solenoid valve 52
Are respectively acted on. For this reason, as shown in Equation 1, the slip control valve 56 sets the differential pressure ΔP (= P _on −P _off ) corresponding to the slip amount to the linear solenoid valve 5.
It operates so as to have a value corresponding to the output pressure P _{lin of} 2.
Here, in Equation 1, F is the pressure receiving area of the hydraulic P _on the urging force of the spring 70, A ₁ is spool,
A ₂ (where A ₁ = A ₂ ) is the pressure receiving area of the hydraulic pressure P _off , A ₃
Is a pressure receiving area of the output pressure P _lin .

[0014]

(Equation 1)

Therefore, in the engagement-control hydraulic control circuit 46 configured as described above, the hydraulic pressure P _on in the engagement-side oil chamber 35 and the hydraulic pressure P _off in the release-side oil chamber 33 are _equal to those in FIG.
As shown in the _figure, the output pressure P _lin of the linear solenoid valve 52
, The linear solenoid valve 52
The switching control of the switching valve 54 and the slip control of the lock-up clutch 32 after the switching valve 54 is switched to the engagement position can be respectively performed by the output pressure P _lin .

The electronic control unit 42 includes a CPU 82, a ROM
84, a RAM 86, a so-called microcomputer comprising an interface (not shown) and the like.
A throttle sensor 88 provided in an intake pipe of the engine 10 for detecting a throttle valve opening, an engine speed sensor 90 for detecting a rotation speed of the engine 10, and an input shaft for detecting a rotation speed of the input shaft 20 of the automatic transmission 14. A rotation sensor 92, an output shaft rotation sensor 94 for detecting the rotation speed of the output shaft 34 of the automatic transmission 14, and an operation position of the shift lever 96, that is, any one of the L, S, D, N, R, and P ranges is detected. from the operating position sensor 98, the signal representing the throttle valve opening theta _th, a signal indicative of the engine rotational speed N _e (pump impeller rotation speed N _P), input shaft rotational speed N _in
(Rotation speed N _{T of} turbine wheel), signal representing output shaft rotation speed N _out , operation position P of shift lever 96
A signal representing _s is supplied.
The CPU 82 of the electronic control unit 42 processes the input signal according to a program stored in the ROM 84 in advance while utilizing the temporary storage function of the RAM 86, and executes the shift control of the automatic transmission 14 and the engagement control of the lock-up clutch 32. For this purpose, the first solenoid valve 48, the second solenoid valve 50 and the linear solenoid valve 52 are controlled, respectively. In the shift control, a shift diagram corresponding to an actual shift speed is selected from a plurality of types of shift diagrams stored in the ROM 84 in advance, and a traveling state of the vehicle, for example, a throttle valve opening θ _th is selected from the shift diagram. And the vehicle speed SPD calculated from the output shaft rotation speed _Nout, the transmission gear stage is determined, and the first electromagnetic valve 48 and the second electromagnetic valve 50 are driven so as to obtain the transmission gear stage. The operation of the clutch and brake of the automatic transmission 14 is controlled to establish any one of the four forward speeds.

The engagement control operation of the lock-up clutch 32 by the electronic control unit 42 will now be described with reference to FIGS.
This will be described in detail with reference to the flowchart shown in FIG. This flowchart is repeatedly executed at regular intervals, for example, every several to several tens of milliseconds.

In FIG. 4, at step S0, the throttle valve opening θ _th , the engine speed N _e , the input shaft speed N _in , and the output shaft speed N, which are the state variables of the running vehicle, based on the input signal. _out and the air-fuel ratio feedback correction signal F _AF are read. Then, step S1
In S4 to S4, the slip control condition at the time of deceleration traveling is determined.

First, at step S1, it is determined whether or not the throttle valve is at an idling opening. If this determination is denied, the vehicle is not decelerating, so that step S6 to be described later is performed.
The following is performed, but if affirmative, other conditions for starting the slip control during deceleration traveling are determined. That is, in step S2, it is determined whether the content of the flag FDS is "1". This flag FDS
Indicates that the slip control is being performed during deceleration running when the content is "1". Initially, the determination in step S2 is denied, so in step S3 the turbine wheel rotation speed _NT is set to the preset lower limit N
It is determined whether it is within the range of _LL1 and the upper limit value _NUL1 . If the determination in step S3 is affirmative, the content of the flag FDS is set to "1" in step S4.
Is set to For this reason, in the next control cycle,
Since the determination in step S2 is affirmative, whether the turbine impeller speed N _T is within the range of the lower limit value N _LL2 and the upper limit value N _UL2 a preset is determined in step S5. In order to form a hysteresis for preventing the determination of the slip control during deceleration from fluttering, the lower limit N
_LL1 is set slightly larger than the lower limit N _LL2 ,
The upper limit N _UL1 is set slightly smaller than the upper limit N _UL2 .

If the determinations in steps S3 and S5 are both negative, the contents of the flags FDS and FM1 are cleared to "0" in steps S6 and S7, respectively, and the count contents of the timer counter CT1 are cleared in step S8. The engagement control of the lock-up clutch 32 when cleared to "0" and in a state other than the slip control during deceleration traveling is executed in steps S9 to S14 in FIG. That is, first, in step S9, for example, it is determined whether or not the running state of the vehicle is within the previously stored engagement area shown in FIG.
If the determination in step S9 is affirmative, the driving current I of the linear solenoid valve 52 is determined in step S10.
_sol is set to the maximum value “100%”, and step S11 is performed.
, The drive current I _sol is output. As a result, as shown in FIG. 3, the hydraulic pressure P _on in the engagement side oil chamber 35 becomes the regulator pressure P _cl which is the maximum value, and the hydraulic pressure P _off in the release side oil chamber 33 becomes the minimum value. That is, since the atmospheric pressure is set, the lock-up clutch 32 is engaged.

However, if the determination in step S9 is negative, it is determined in step S12 whether or not the running state of the vehicle is, for example, within the previously stored slip control area shown in FIG. If the determination in step S12 is negative, since the traveling state of the vehicle is in a state within the release region of FIG. 7, the driving current I _sol minimum value "0 of the linear solenoid valve 52 in step S13
% ". Thereby, the hydraulic pressure P _off in the release side oil chamber 33 is set to the regulator pressure P _cl which is the maximum value, and at the same time, the hydraulic pressure P _on in the engagement side oil chamber 35 is set to the minimum value,
That is, since the pressure is set to the atmospheric pressure, the lock-up clutch 3
2 is released.

However, if the determination in step S12 is affirmative, in step S14, the torque fluctuation of the engine 10 is absorbed in order to improve the fuel economy as much as possible without impairing the drivability. The drive current I _sol of the linear solenoid valve 52 is set to a preset value, and the lock-up clutch 32 is slipped.

If either of the determinations in steps S3 and S5 in FIG. 4 is affirmed, steps S15 and subsequent steps shown in FIGS. 4 and 5 are executed in order to execute the slip control during deceleration traveling. You. First, step S15
Then, it is determined whether or not the content of the flag FM1 is "1". When the content of the flag FM1 is "1", the flag FM1 indicates that the correction by learning of the feedback term in the control formula described later has been completed. Initially, the content of the flag FM1 is "0", so that step S1
The judgment of 5 is denied. Therefore, in step S16, the count of the timer counter CT1 is performed, and after the content thereof is added, it is determined in step S17 whether or not the content of the timer counter CT1 has reached a preset elapsed time CA. If the determination is affirmative, it is determined in step S18 whether or not the content of the timer counter CT1 has reached a preset elapsed time CB. The timer counter CT1 is for counting the elapsed time since the start condition of the slip control during the deceleration running is satisfied. Further, as shown in the time chart of FIG. 8, the elapsed times CA and CB are erroneously determined immediately after the start because the rate of change dN _e / dt becomes zero, and as shown in Case 1 of FIG. In order to eliminate the inability to make a determination due to the change in the engine speed _Ne , a period for detecting a rapid decrease width of the engine rotation speed Ne is set. If the determination in step S15 is affirmative, the learning is once corrected and it is not necessary to perform learning again.
26 and below are executed. Further, if the determination in step S17 is negative, since the period is not necessary to detect the decrease width of the engine rotational speed N _e, likewise the step S26 following is performed.

If the determination in step S17 is affirmative and the determination in step S18 is negative, the elapsed time from the start of the slip control during deceleration traveling is determined by the C time.
A and before reaching SB, in step S19, the rate of change dN _e / d of the engine rotational speed.
with t is calculated, whether the host vehicle has reached the rate of change dN _e / dt of the engine rotational speed is zero in step S20 (the inflection point of the curve showing the engine rotational speed N _e) is determined. Thus, the rate of change of the engine speed dN
By detecting an inflection point at which _e / dt becomes zero, that is, a minimum point , the energy of the minimum point is detected in step S21 and subsequent steps.
Since the decline of the engine speed N _e generated by the slip control during deceleration from engine speed N _e is determined, in the present embodiment, Step S20 determines the range of decrease of the engine rotational speed N _e engine It corresponds to the rotation speed reduction width determining means. Change rate of engine speed dN
_{If e} / dt has not become zero yet, the above step S
The determination at 20 is denied, and step S26 and subsequent steps are executed. However, if the change of the engine rotational speed N _e by the start of the slip control during deceleration is completed, as shown in FIG. 8, the rate of change dN Te minimum point smell <br/> the engine rotational speed N _e since the _e / dt, in its minimum point determination in step S20 is affirmative, feed-Wert claim step S21 for a line of cormorants fixes the following are performed in controlled will be described later. In step S18
And the content of the counter CT1 has reached the elapsed time CB
If the judgment is made, the above steps S21 and subsequent steps are executed.
You. After step S21, the elapsed time CB is reached.
Scan during deceleration from engine speed N _e on reaching
Reduction of the engine rotational speed N _e generated by the lip control
Since the width is determined, in the present embodiment, step S1
8 also engine that determines the range of decrease of the engine rotational speed N _e
This corresponds to the rotation speed reduction width determining means.

In step S21, the engine speed N
_It is determined whether or not _e is larger than a value obtained by subtracting the first determination reference value N _C1 from the turbine rotation speed N _T (N _T −N _C1 ). If the determination of step S21 is positive, as shown in FIG. 9, since it is within the range of the A region with a small decline of the engine speed N _e, the decrease width of the engine rotational speed N _e Step S for further enlargement
22, the feedforward learning value I so far
_G feedforward by certain decrease amount I _C1 from _(i) is subtracted learning value I _{G (i)} is updated. If the determination in step S21 is negative, step S2
In 3, the engine rotation speed _Ne is equal to the turbine rotation speed N.
The value obtained by subtracting the second determination reference value N _C2 from _T (N _T -
It is determined whether it is smaller than N _C2 ). Step S2
If the third determination is affirmative, as shown in case 2 of FIG. 10 or FIG. 8, since the the range of C region decline of the engine speed N _e is increased undershoot, the engine feedforward learning value I _{G (i)} is updated by adding a predetermined increment I _C2 to it to the feedforward learning value I _{G (i)} in step S24 in order to reduce the range of decrease of the rotational speed N _e You.

[0026] Then, since when the determination in step S23 is negative, as shown in FIG. 11, the range of decrease of the engine rotational speed N _e is a suitable just within the B region, decline of the engine speed N _e is not varied. Then, after execution of step S23 or step S22 or S24, in step S25, the content of the flag FM1 indicating that the learning has been corrected is set to "1". The first judgment reference value N _C1 and the second judgment reference value N _C2 are for judging whether or not the rotational speed reduction range of the engine is within the B region which is the target value. As shown,
The first criterion value N _C1 and the second determination reference value N _C2, as described above B area is substantially equal area and turbine rotational speed N _T, each set predetermined value lower than the turbine impeller speed N _T Have been. In addition, as shown in case 1 of FIG. 8, when the reduction of the engine rotational speed N _e is gentle, the determination in step S18 is affirmative, the area determination in steps S21 and S23 is carried out at that time.

In the following step S26, the feedforward basic value I _{F / F} ′ is stored in advance in the relation [I _{F / F} ′ =
f ₁ ( _NT )] based on the actual turbine wheel rotational speed _NT , and in step S27, the learning value _{IG (i)} (correction value) is added to the feedforward basic value _{IF / F} '. Is added, the feedforward control value _{IF / F} (= _{IF / F} '+ _{IG (i)} ) is calculated.

Next, in step S28, the target slip rotational speed N _slip ^T is stored in advance in a relation [N _slip ^T = f
₂ (N _T , θ _th )] to the actual turbine wheel rotation speed N
It is calculated based on _T. This relationship is obtained experimentally in advance to absorb the torque fluctuation of the engine 10 and improve the fuel economy as much as possible during traveling in the slip control region of FIG. 7, for example, as shown in FIG. It is. Then, in step S29, the actual slip rotation speed N _slip is calculated from Expression 2, and in step S30
Then, the control deviation ΔN _d is calculated from Expression 3.

[0029]

(Equation 2)

[0030]

(Equation 3)

In step S31, a feedback control value I _{F / B} is calculated from the PID control equation shown in equation (4).
Then, in step S32, as shown in Expression 5, the feedforward control value and the feedback control value I
By adding _{F / B} , a control value in slip control of the lock-up clutch, that is, a drive current I _sol for driving the linear solenoid valve 52 is calculated. The control expression shown in Expression 5 is for executing the slip control so that there is no response delay and the control deviation ΔN _d is eliminated.

[0032]

(Equation 4)

[0033]

(Equation 5)

In the control formula of the above equation (5), the first term on the right side is a feedforward control term that is corrected by learning so that the decrease in the engine speed due to the start of the slip control during deceleration running becomes the target value. The second term on the right side is a PID feedback control term for performing PID control to eliminate the deviation ΔN. Therefore, the slip control based on the control formula of Expression 5 is configured as shown in a control block diagram shown in FIG.

As described above, in the present embodiment, in steps S21 to S24 corresponding to the control type correcting means, the range of decrease in the engine rotational speed which occurs at the start of the slip control during deceleration traveling is set to a predetermined target. The control formula shown in the above equation 5 is modified so as to have a decrease width.
That is, the feedforward term of the control formula is corrected by learning so that the actual decrease in the engine rotational speed that occurs at the start of the slip control during deceleration traveling becomes a predetermined target decrease value (a value in the B region). Is done. Therefore, according to the present embodiment, since the control formula is modified according to the individual difference and the aging of the lock-up clutch 32, regardless of the individual difference and the aging of the lock-up clutch 32,
Slip control during proper deceleration traveling can be obtained.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 14 shows steps S17 through S17 in FIG.
An example in which 20 is replaced with a new step S20 'is shown. In the figure, in step S20 ', the elapsed time CT from the start of the slip control during deceleration traveling is shown.
It is determined whether 1 has reached a predetermined reference value CJ. The criterion value CJ, like changes in the range of decrease of the engine rotational speed N _e is capable shown, for example, FIG. 8
Or is set to the elapsed time value shown in FIG. 11, the determination in step S20 'is adapted to be a region determined based on the engine rotational speed N _e when it is affirmative. In this embodiment, the step S20 'corresponds to the engine speed reduction width determining means.

[0038] According to this embodiment, the engine rotational speed the engine rotational speed N by being area determination based on the engine rotational speed N _e at which certain age CJ from the start of the slip control has elapsed during deceleration _Since it is determined whether or not the decrease width of _e is a predetermined target decrease width, the same effect as in the above-described embodiment can be obtained. In addition,
The first criterion value N _C1 and the second criterion value N _C2 used for region determination may be shifted as necessary.

Although the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, in the above-described embodiment, the automatic transmission 14 having the torque converter 12 with the direct coupling clutch
However, the automatic transmission may be provided with a fluid coupling with a direct coupling clutch. In short, any automatic transmission having a fluid transmission having a direct coupling clutch may be used.

In the above-described embodiment, the vehicle in which the stepped automatic transmission 14 is provided after the torque converter 12 has been described. However, a continuously variable transmission may be provided.

In the engagement control hydraulic control circuit 46 of the above-described embodiment, the differential pressure ΔP (= P _on
−P _off ) is used to operate the slip control valve 56 so as to have a value corresponding to the output pressure P _lin of the linear solenoid valve 52. In this way, the differential pressure ΔP is automatically changed to the output pressure P _lin . A normal flow control valve that does not operate to a corresponding value or a duty-driven on-off type solenoid valve may be used.

The above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram showing the gist of the present invention.

FIG. 2 is a diagram showing a control device according to an embodiment of the present invention and a vehicle power transmission device to which the control device is applied;

3 is a diagram _showing an output pressure P _lin of a linear solenoid valve, an engagement side oil chamber oil pressure P _{on of a} lock-up clutch, and a release side oil chamber oil pressure P _{off in} the engagement control oil pressure control circuit of FIG.
FIG.

FIG. 4 is a flowchart illustrating a slip control operation by the electronic control device of FIG. 2 together with FIGS. 5 and 6;

FIG. 5 is a flowchart illustrating a slip control operation by the electronic control device of FIG. 2 together with FIGS. 4 and 6;

FIG. 6 is a flowchart illustrating a slip control operation by the electronic control device of FIG. 2 together with FIGS. 4 and 5;

FIG. 7 is a diagram showing a relationship used in the flowchart of FIG. 6;

FIG. 8 is a time chart for explaining the operation of the electronic control device shown in FIGS. 4 to 6;

FIG. 9 is a time chart for explaining the operation of the electronic control device shown in FIGS. 4 to 6, and shows a case where the decrease in the engine speed is small.

FIG. 10 is a time chart for explaining the operation of the electronic control device shown in FIGS. 4 to 6, and is a diagram showing a case where the decrease in the engine speed is large.

FIG. 11 is a time chart for explaining the operation of the electronic control device shown in FIGS. 4 to 6, and is a diagram showing a case where the decrease in the engine speed is appropriate.

FIG. 12 is a diagram showing a relationship used in the flowchart of FIG. 5;

FIG. 13 is a control block diagram showing a configuration of slip control of the electronic control device of FIGS. 4 to 6;

FIG. 14 is a diagram showing a main part of a flowchart in another embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 10 engine 14 automatic transmission 32 lock-up clutch (directly-coupled clutch) 42 electronic control device (slip control device) 90 engine rotation speed sensor (engine rotation speed detection means) Steps S20, S20 'engine rotation speed reduction width determination means Steps S21 to S21 S24 Control type correction means

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-1458 (JP, A) JP-A-2-195072 (JP, A) JP-A-3-61761 (JP, A) JP-A-1- 141273 (JP, A) JP-A-1-112207 (JP, A) JP 2-586 (JP, B2)

Claims (2)

(57) [Claims] In a vehicle having a fluid transmission with a direct coupling clutch inserted in a power transmission path from an engine to a driving wheel, a deceleration running in which a throttle valve is an idle opening includes a feedforward correction term in advance. What is claimed is: 1. A slip control device comprising: slip control means for performing slip control of said direct-coupled clutch in accordance with a stored control formula, wherein: an engine speed detection means for detecting an engine speed; of
Engine rotation speed reduction width determining means for determining the reduction width of the engine rotation speed from the start of the reduction to the minimum point of the engine rotation speed, and a predetermined target reduction width of the engine rotation speed. And a control-type correcting means for correcting the feed-forward term of the control type. 2. A vehicle having a fluid transmission with a direct coupling clutch interposed in a power transmission path from an engine to driving wheels includes a feedforward correction term in a deceleration running mode in which a throttle valve has an idle opening degree. in accordance with the stored controlled by a slip control device provided with a slip control means for slip control of the lockup clutch, and the engine speed detecting means for detecting an engine rotational speed, the slip control start condition given from establishment Until after
Engine rotational speed decrease width determining unit, controlled to the range of decrease of the engine rotational speed for correcting the controlled feed-forward term to be a predetermined target decline for determining the range of decrease of the engine rotational speed in the And a correcting means.