JP3218758B2 - Lock-up clutch slip control device - 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 lock-up clutch which controls a slip amount by adjusting a hydraulic pressure supplied to a lock-up clutch of an automatic transmission.

[0002]

2. Description of the Related Art As a conventional slip control device for a lock-up clutch, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. 4-203560.

This slip control device calculates a control signal value (specifically, a duty ratio) corresponding to a target slip amount from engine torque, and calculates a control signal value based on a difference between the target slip amount and the actual slip amount. Is feedback-controlled to make the actual slip amount converge to the target slip amount. In addition, in this slip control device, the learning correction amount is set for each of a plurality of regions according to the throttle opening, and when the integral term of the feedback amount is equal to or more than a predetermined value and it is estimated that the control deviation is large, By correcting the learning correction amount in the corresponding area in a direction to supplement the feedback amount, and adding such a learning correction amount to the feedback control, the convergence of the actual slip amount is accelerated, and the responsiveness of the control is improved. .

[0004]

FIG. 10 is an explanatory diagram showing a control range of a control signal value with respect to a slip amount in a conventional lock-up clutch slip control device.

[0005] However, the above-described slip control device for a lock-up clutch has a control waste described below, and sufficient responsiveness cannot be expected. That is, for example, the slip amount at high load follows the characteristic shown by the solid line in the figure, and the slip amount at low load follows the characteristic shown by the broken line
Each is controlled within the range of 0 to the maximum value. In the conventional slip control device, in order to realize the slip amount, the control signal value is set in a range of 0 to 100%, and the hydraulic pressure supplied to the lock-up clutch is controlled in a range of 0 to a maximum value. are doing. However, as is apparent from the figure, in the region where the hydraulic pressure is near 0 and the maximum value (the region other than the inclined portion in the diagram), the slip amount is the maximum value or 0.
Therefore, there is a problem in that the control is delayed by the required time in this useless area and the responsiveness is reduced.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a lock-up clutch slip control device capable of preventing a control of supply hydraulic pressure to a lock-up clutch in a useless region, avoiding a control delay, and improving responsiveness. Is the subject.

[0007]

As shown in FIG. 1, a slip control device for a lock-up clutch according to the present invention comprises: an operating state determining means M1 for determining an operating state; The current lock-up clutch changes the slip amount based on the
Supply to the lock-up clutch according to the range
And learning means M2 for learning a range of control values for setting the supply pressure of the hydraulic oil, range of learned control value by said learning means M2
Hydraulic pressure setting means M3 for setting the supply hydraulic pressure based on the surroundings
And hydraulic control means M4 for controlling the actual hydraulic pressure supplied to the lock-up clutch based on the supply hydraulic pressure set by the hydraulic pressure setting means M3.

[0008]

According to the present invention, the current lock-up torque is determined based on the operating state determined by the operating state determining means M1.
According to the range in which the latch can change the slip amount,
System for setting hydraulic pressure supplied to lock-up clutch
The range of the control value is learned by the learning means M2, and the control value is obtained.
The supply oil pressure to the lock-up clutch is set by the oil pressure setting means M3 based on the range, and the actual supply oil pressure is controlled by the oil pressure control means M4.

Therefore, the hydraulic pressure supplied to the lock-up clutch is always constant regardless of the change in the operating state .
The control is performed within a minimum range necessary for controlling the slip amount of the latch , and hydraulic control in a useless region where the slip amount does not change is prevented, so that control delay can be avoided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will now be given of a slip control device for a lock-up clutch according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing an internal combustion engine and an automatic transmission to which a slip control device for a lock-up clutch according to an embodiment of the present invention is applied.

As shown in the figure, a throttle valve 3 is provided in an intake pipe 2 of an internal combustion engine 1, and the throttle valve 3 regulates the amount of intake air supplied to the internal combustion engine 1 to control the engine output. You. A transmission mechanism 7 is connected to the crankshaft 4 of the internal combustion engine 1 via a torque converter 6 of the automatic transmission 5 (separated from the internal combustion engine 1 for convenience), and the transmission mechanism 7 is a vehicle not shown. Are connected to the drive wheels via the drive system. A lock-up clutch 8 is provided in the torque converter 6, and the lock-up clutch 8 is supplied with hydraulic oil in accordance with a switching operation of a clutch control solenoid 9, and is switched between an open state and an engaged state, and In the meantime, an arbitrary slip amount (slip ratio) is adjusted.

As is well known, when the lock-up clutch 8 is released, the torque of the internal combustion engine 1 is transmitted to the speed change mechanism 7 via the torque converter 6, and when the lock-up clutch 8 is engaged, the torque converter 6 The transmission is transmitted to the transmission mechanism 7 via the lock-up clutch 8 without any intervention, while the transmission is transmitted to the transmission mechanism 7 via the torque converter 6 and the lock-up clutch 8 at a rate corresponding to the slip amount during intermediate slip control. .

An electronic control unit 11 (hereinafter simply referred to as "ECU") for controlling the lock-up clutch 8 constitutes a logic operation circuit centered on a CPU, ROM and RAM (not shown). A throttle opening sensor 12 for detecting the opening TA of the throttle valve 3, an engine speed sensor 13 for detecting the rotation speed Ne of the internal combustion engine 1, and a turbine rotation speed provided on the input side of the speed change mechanism 7 are connected. A turbine speed sensor 14 for detecting NT and an output speed sensor 15 provided on the output side of the speed change mechanism 7 for detecting the output speed NO are connected.

Then, based on the detection value of each sensor, EC
U11 appropriately sets a control signal value (specifically, a duty value) to be output to the clutch control solenoid 9, adjusts a hydraulic pressure of hydraulic oil supplied from the clutch control solenoid 9 to the lock-up clutch 8, and Control the fastening state. Further, the ECU 11 of the present embodiment performs not only the control of the lock-up clutch 8 but also the shift control of the automatic transmission 5 and the operation control including the fuel cut of the internal combustion engine 1.

Next, control processing of the slip amount of the lock-up clutch 8 by the ECU 11 of the slip control device configured as described above will be described.

FIG. 3 is a flowchart showing a control signal value calculation routine of a lock-up clutch slip control device according to one embodiment of the present invention. FIG. 4 is a flowchart of a lock-up clutch slip control device according to one embodiment of the present invention. 5 is a flowchart showing a routine for calculating a maximum slip amount, FIG. 5 is a flowchart showing a routine for calculating an upper limit control signal value of the slip control device for a lock-up clutch according to an embodiment of the present invention, and FIG. FIG. 7 is a flowchart showing a control range setting routine of the up-clutch slip control device. FIG. 7 is an explanatory diagram showing a map for calculating the maximum slip amount of the lock-up clutch slip control device according to one embodiment of the present invention. Is the upper limit control signal value of the lock-up clutch slip control device according to one embodiment of the present invention. Explanatory view showing a map for calculating, FIG. 9 is an explanatory diagram showing a control range of the control signal value with respect to the slip amount of the slip lockup clutch control apparatus which is an embodiment of the present invention.

The routine shown in FIGS. 3 to 6 is executed every 1 msec. First, the control signal value calculation routine of FIG. 3 will be described. In step S1, the ECU 11 executes a maximum slip amount calculation routine described later, and obtains a maximum slip amount MAXSLP which is a slip amount when the clutch is released shown in FIG.
Is calculated. Next, in step S2, an upper limit control signal value calculation routine described later is executed to calculate an upper limit control signal value APDUTY which is a control signal value at the time of clutch engagement.
Further, the throttle opening T detected by the throttle opening sensor 12 according to a map (not shown) in step S3.
The target slip amount TGSLP of the lock-up clutch 8 is set from A and the turbine speed NT detected by the turbine speed sensor 14. Thereafter, in step S4, a control range setting routine described later is executed, and the control range SDU set from the maximum slip amount MAXSLP, the upper limit control signal value APDUTY and the target slip amount TGSLP is set.
Within TY, an expected control signal value MDSLU is calculated from the target slip amount TGSLP. Note that the maximum slip amount MA
Each value of the XSLP, the upper limit control signal value APDUTY, and the like changes when the load state of the lock-up clutch 8 changes according to the operating state of the internal combustion engine 1, the automatic transmission 5, the vehicle, or the like. FIG. 9 shows characteristics under a high load.

Next, at step S5, a difference ΔSLP between the target slip amount TGSLP and the actual slip amount NSLP (engine speed Ne−turbine speed NT) is calculated. At step S6, the actual slip amount is calculated based on the difference ΔSLP. A feedback correction amount DFB for converging the amount NSLP to the target slip amount TGSLP is calculated. Further, in step S7, this feedback correction amount DFB is added to the expected control signal value MDSLU to calculate a final control signal value DSLU. In step S8, the final control signal value DSLU is output to the clutch control solenoid 9. This routine ends.

As a result, the hydraulic pressure supplied from the clutch control solenoid 9 to the lock-up clutch 8 is controlled according to the final control signal value DSLU, and the actual slip amount is adjusted to the target slip amount TGSLP.

When the maximum slip amount calculation routine is called in step S1 of the control signal value calculation routine as described above, the ECU 11 proceeds to step S11 in FIG. The throttle opening TA is read, and the turbine speed NT detected by the turbine speed sensor 14 is read in step S12. Next, in step S13, the ROM shown in FIG.
The maximum slip amount MAXSLP is calculated from the throttle opening TA and the turbine speed NT in accordance with the map stored in the routine, and this routine is terminated. In FIG. 7, a represents the throttle opening TA and b represents the turbine rotation speed NT.
Is read, and as a result, the maximum slip amount MAXSLP
Shows a case where c is calculated.

Further, when the upper limit control signal value calculation routine is called in step S2 of the control signal value calculation routine,
As in the maximum slip amount calculation routine described above, the ECU
11 is the throttle opening TA in step S21 of FIG.
At step S22, the turbine rotational speed NT is read, and at step S23, the upper limit control signal value APDUTY is calculated according to the map shown in FIG.

On the other hand, when the control range setting routine is called in step S4 of the control signal value calculation routine, the ECU
In step S31 of FIG. 6, the upper limit control signal value APDUTY is read in step S31 of FIG. Calculate the range SDUTY. That is, the calculated control range SDUTY indicates a range in which the slip amount changes according to the control signal value (a slope portion in FIG. 9). Next, at step S33, the maximum slip amount M
AXSLP is read, and in step S34, the control range SDUTY is divided by the maximum slip amount MAXSLP to calculate a slope TOKO of the control range SDUTY. After that, in step S35, the gradient TOKO is multiplied by the target slip amount TGSLP, and the lower limit control signal value LWDUTY is obtained.
Is added to calculate the expected control signal value MDSLU, and this routine ends.

If the operating state of the internal combustion engine 1, the automatic transmission 5, the vehicle, or the like changes, the control range SDUTY is sequentially learned in step S32, and the prospective control within the control range SDUTY is performed in step S35. The signal value MDSLU is set. Therefore, the hydraulic pressure of the clutch control solenoid 9 is always controlled within the control range SDUTY, in other words, within the minimum range necessary for controlling the slip amount, regardless of the change in the operating state. Oil pressure control in a useless area where the amount does not change is prevented, and control delay can be avoided.

As described above, in the present embodiment, the throttle opening sensor 12 and the turbine speed sensor 14 function as the operating state determining means M1, and steps S11 to S13 and step S21 serve as the control range learning means M2.
To S23, S31 and S3
The ECU 11 when executing the processing of step 2 functions as the hydraulic pressure setting means M3, and the ECU 11 when executing the processing of steps S33 to S35 functions as the hydraulic pressure setting means M4, and the clutch control solenoid 9 functions as the hydraulic control means M4.

As described above, the slip control device of the lock-up clutch according to the present embodiment includes the throttle opening sensor 12 for detecting the throttle opening TA of the internal combustion engine 1 and the turbine for detecting the turbine speed NT of the automatic transmission 5. Based on the rotational speed sensor 14, the throttle opening TA and the turbine rotational speed NT, the current lock-up clutch 8 can change the slip amount from 0 to the maximum slip amount MAXSL.
Supply to the lock-up clutch 8 corresponding to the range of P
ECU11 for learning the control range SDUTY of the prospective control signal value MDSLU for setting the oil pressure, setting the prospective control signal value MDSLU within the learned control range SDUTY, and the prospective control signal value MDSLU set by the ECU11 And a clutch control solenoid 9 for controlling the hydraulic pressure of the hydraulic oil supplied to the lock-up clutch 8 based on the

Accordingly, the hydraulic pressure of the clutch control solenoid 9 is always controlled within the minimum necessary control range SDUTY irrespective of the change of the operation state, so that the hydraulic control in a useless area where the slip amount does not change is prevented. Responsiveness can be improved by avoiding control delay.

In the above embodiment, the maximum slip amount MAXSLP and the upper limit control signal value APDUTY are calculated based on the throttle opening TA and the turbine speed NT. However, the present invention is not limited to this. Instead, it can be calculated based on various parameters relating to the operating state of the internal combustion engine 1, the automatic transmission 5, the vehicle, or the like. Therefore, for example, instead of the throttle opening TA, an intake negative pressure indicating the load state of the internal combustion engine 1 or a value obtained by dividing the intake air amount by the engine speed Ne may be used.

In the above embodiment, the target slip amount TG
The values such as the SLP, the maximum slip amount MAXSLP, and the upper limit control signal value APDUTY were individually calculated according to one type of map. However, the present invention is not limited to this. A map having different characteristics may be prepared for each shift speed of the machine 5, and these values may be calculated according to the map corresponding to the shift speed. As a result, more precise control of the slip amount becomes possible, and deterioration of drivability due to the slip control can be prevented.

[0030]

As described above, according to the slip control device for a lock-up clutch of the present invention, the hydraulic pressure supplied to the lock-up clutch is always controlled within the minimum necessary control range irrespective of the change of the operation state. Therefore, it is possible to prevent hydraulic control in a useless region where the slip amount does not change, and to improve controllability by avoiding control delay.

[Brief description of the drawings]

FIG. 1 is a claim correspondence diagram conceptually showing the contents of one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an internal combustion engine and an automatic transmission to which a slip control device for a lock-up clutch according to an embodiment of the present invention is applied;

FIG. 3 is a flowchart showing a control signal value calculation routine of a lock-up clutch slip control device according to an embodiment of the present invention.

FIG. 4 is a flowchart showing a maximum slip amount calculation routine of a lock-up clutch slip control device according to an embodiment of the present invention.

FIG. 5 is a flowchart showing an upper limit control signal value calculation routine of the lock-up clutch slip control device according to one embodiment of the present invention.

FIG. 6 is a flowchart illustrating a control range setting routine of the lock-up clutch slip control device according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a map for calculating a maximum slip amount of a slip control device for a lock-up clutch according to one embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a map for calculating an upper limit control signal value of the lock-up clutch slip control device according to one embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a control range of a control signal value with respect to a slip amount in a lock-up clutch slip control device according to one embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a control range of a control signal value with respect to a slip amount in a conventional lock-up clutch slip control device.

[Explanation of symbols]

M1 Operating state determination means M2 learning means M3 Hydraulic pressure setting means M4 Hydraulic control means 8 Lock-up clutch 9 Clutch control solenoid 11 ECU 12 Throttle opening sensor 14 Turbine speed sensor

Claims (1)

(57) [Claims] An operating state determining means for determining an operating state, and a current lock-up clutch changes a slip amount based on the operating state determined by the operating state determining means.
Supply to the lock-up clutch according to the range
And learning means for learning the range of control values for setting the supply pressure of the hydraulic oil, before based on the range of learned control value by said learning means
A hydraulic setting means for setting a serial supply hydraulic, and wherein based on the set hydraulic pressure supplied by a hydraulic setting means, and a hydraulic pressure control means for controlling the actual hydraulic pressure supplied to the lock-up clutch Lock-up clutch slip control device.