JP2004138147A - Lock-up clutch fastening force control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set adequate open control completion rotation even in different traveling circumstances such as an uphill road and a flat road. <P>SOLUTION: A slip control device comprises a lockup clutch 2c disposed between input and output elements of a torque converter 2 to transmit the power from a prime mover 1 and a hydraulic pressure control means to adjust the hydraulic pressure fed to the lockup clutch 2c and control the fastening state, and controls the slip rotation ω<SB>SLP</SB>between the input and output elements according to the fastening state of the lockup clutch 2c. The slip control device further comprises a means to perform open control to increase the lockup hydraulic pressure toward the target value as the fastening control of the lockup clutch 2c is started, a means to perform feedback control of the lockup hydraulic pressure according to the deviation between the target slip rotation ω<SB>SLPT</SB>and the actual slip rotation ω<SB>SLPR</SB>when the slip rotation ω<SB>SLP</SB>corresponding to the differential in number of rotation between the input element and the output element is not larger than a set value, and a means to correct the set value based on the change ΔN<SB>pri</SB>in the primary rotation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a torque converter slip control device used for an automatic transmission including a continuously variable transmission.
[0002]
[Prior art]
The lock-up control device of the torque converter inserted in the power transmission system of the automatic transmission including the continuously variable transmission requires a torque increasing effect and a shift shock to reduce the deterioration of fuel efficiency due to the slip of the torque converter. In the operating region where the torque converter is not set, the input and output elements of the torque converter are directly connected. This state is called a lock-up mode. In addition, a converter mode in which the input / output elements are completely opened to transmit torque through a fluid, and a lock-up clutch is half-engaged and a predetermined slip state is maintained. There are three modes including the slip mode, and the mode is appropriately switched according to the operating state. Control in the converter mode is referred to as converter control, control in the slip mode is referred to as slip control, and control in the lockup mode is referred to as lockup control.
[0003]
Generally, in slip control, immediately after the start of control, the differential pressure is increased by open control, and thereafter, the control is switched to feedback control, and a target slip rotation speed is determined from a driving state of the vehicle determined based on a throttle opening, a vehicle speed, and the like. The engagement force of the lock-up clutch is controlled so that the actual slip rotation speed of the converter becomes the target slip rotation speed.
[0004]
However, with respect to the slip control described above, the responsiveness of the actual slip to the target slip speed, that is, the response of the feedback control is uniquely determined by the transfer characteristic of the slip rotation feedback control system. However, there is a problem in that an operating state in which the state deteriorates occurs.
[0005]
In order to solve this problem, there is a method of using a target slip rotational speed correction value obtained by passing a target slip rotational speed through a compensation filter according to a vehicle operating state of a front compensator (Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent No. 3240979
[0007]
[Problems to be solved by the present invention]
However, Patent Document 1 does not mention the timing of switching from the open control to the feedback control, and the control of the slip rotation speed immediately after switching to the feedback control.
[0008]
If the timing of switching from the open control to the feedback control is bad and the lock-up differential pressure is too high or insufficient, the actual slip speed immediately after the switch greatly deviates from the target slip speed, and the engine speed is reduced. Hunting may occur.
[0009]
In particular, if the differential pressure is excessively increased at a low throttle opening, the engine rotation will suddenly drop, causing a lock-up clutch engagement shock. Lock-up release shock may be caused by suddenly returning to the converter mode.
[0010]
Therefore, depending on driving conditions, the differential pressure at the start of feedback control may be too high or may be insufficient. Due to these factors, slip rotation may deviate significantly from the target immediately after feedback control starts, and hunting of engine rotation may occur. And the like, which deteriorates drivability and merchantability.
[0011]
In view of the above, an object of the present invention is to make it possible to always set an appropriate open control end rotation even in different driving situations.
[0012]
[Means for Solving the Problems]
The present invention includes a lock-up clutch disposed between input and output elements of a torque converter for transmitting power from a prime mover, and hydraulic control means for adjusting a supply hydraulic pressure to the lock-up clutch to control an engagement state thereof. In a slip control device that controls the slip rotation between the entry output elements according to the engagement state of the lock-up clutch, open control is performed to increase the lock-up oil pressure toward the target pressure with the start of engagement control of the lock-up clutch. Means for performing feedback control of the lock-up hydraulic pressure according to the deviation between the target slip rotation and the actual slip rotation when the slip rotation corresponding to the rotation speed difference between the input element and the output element becomes equal to or less than a set value; Means for correcting the set value based on the amount of change in rotation.
[0013]
[Action / Effect]
According to the present invention, the slip rotation set as the open control end condition is corrected so as to change according to the rising speed of the primary rotation even at the same throttle opening degree on an uphill road or a flat road. An appropriate termination condition can be set according to.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
FIG. 1 shows a drive system of a vehicle including a torque converter provided with a slip control device according to a first embodiment of the present invention, wherein 1 is an engine as a prime mover, and 2 is a power transmitted from an engine 1 to an automatic transmission 3. The torque converter 4 is a differential gear device that transmits the power output from the automatic transmission 3 to the tire 5.
[0016]
In the torque converter 2, a pump impeller 2a as an input element driven by the engine 1 and a turbine runner 2b as an output element connected to an input shaft of the transmission 3 are provided. Power is transmitted between the input and output elements through the power supply.
[0017]
Further, a lock-up clutch 2c that rotates together with the turbine runner 2b is provided. When the lock-up clutch 2c is engaged with the pump impeller 2a, the torque converter 2 enters a lock-up state in which input and output elements are directly connected.
Reference numeral 11 denotes a lock-up control valve for controlling a differential pressure for operating the lock-up clutch 2c, and 13 denotes a signal pressure P to the lock-up control valve 13. _S Is a controller for instructing a lock-up duty D to a lock-up solenoid 13 based on a signal from each sensor.
[0018]
Here, the operation of the lock-up clutch 2c will be described with reference to FIG.
[0019]
The lock-up clutch 2c has torque converter apply pressure (hereinafter referred to as apply pressure) P on both sides thereof. _A And torque converter release pressure (hereinafter referred to as release pressure) P _R Differential pressure P _A -P _R And the release pressure P _R Is the apply pressure P _A If the pressure is higher than the lock pressure, the lock-up clutch 2c is released and the torque converter input / output element is not directly connected. _R Is the apply pressure P _A If it is lower than this, the lock-up clutch 2c is engaged and directly connects the input and output elements of the torque converter.
[0020]
In the direct connection state, the engagement force of the lock-up clutch 2c, that is, the lock-up capacity is equal to the differential pressure P. _A -P _R The lockup capacity of the lockup clutch 2c increases as the differential pressure increases.
[0021]
The differential pressure P _A -P _R Is controlled by a lock-up control valve 11, and the lock-up control valve 11 _A And release pressure P _R Are applied face to face, and the applied pressure P _A The spring force of the spring 11a in the same direction as the release pressure P _R Signal pressure P described later in the same direction as _S Act.
[0022]
The lock-up control valve 11 controls the differential pressure P so that these forces are balanced. _A -P _R To determine. Where the signal pressure P _S Is the pump pressure P _P Is generated by the lock-up solenoid 13 in accordance with the lock-up duty D output from the controller 12 using the pressure as the original pressure.
[0023]
The controller 12 receives signals indicating the running state of the vehicle and the driving state of the driver, for example, signals from an output shaft rotation sensor, a turbine rotation sensor 23, an impeller rotation sensor 22, an ATF oil temperature sensor 24, and the like. Control such as engagement and release of the lock-up clutch is performed based on this.
[0024]
The controller 12 calculates the drive duty S of the lock-up solenoid 13 by calculation in accordance with the control system configuration diagram shown in FIG. _DUTY And a correction is made in accordance with the signal from the power supply voltage sensor 28 to determine the lock-up duty D.
[0025]
FIG. 3 shows a control system configuration diagram of the controller 12, and the calculation inside the controller 12 will be described.
[0026]
In the target slip rotation calculating section (S100), the vehicle speed signal v from the vehicle speed sensor 25, the throttle opening signal TVO from the throttle opening sensor 21, the speed ratio signal ip obtained by the speed ratio calculating section 26, the ATF oil temperature sensor 24 The target slip rotation ω is set at the position where the torque fluctuation and the muffled noise are minimized based on the oil temperature signal TATF from the _SLPT To determine.
[0027]
In the actual slip rotation calculation unit (S103), the rotation speed ω of the pump impeller 2a is _IR Speed of the turbine runner 2b _TR Is subtracted from the actual slip rotation ω of the torque converter 2. _SLPR Is calculated. Here, the rotation speed of the pump impeller 2a is equivalent to the rotation speed of the engine 1, and the rotation speed of the turbine runner 2b is equivalent to the primary rotation speed.
[0028]
In the pre-compensator (S101), the target slip rotation ω _SLPT Is passed through a compensating filter set so as to have a response intended by the designer, so that the target slip rotation correction value ω _SLPTC Is calculated.
[0029]
In the slip rotation deviation calculation unit (S102), the first target slip rotation correction value ω _SLPTC1 And actual slip rotation speed ω _SLPR And slip rotation deviation ω _SLPER To
ω _SLPER = Ω _SLPTC −ω _SLPR ... (1)
It is calculated from:
[0030]
In the slip rotation command value calculation unit (S104), the slip rotation deviation ω _SLPER In order to eliminate the first slip rotation command value ω, a feedback compensator configured by proportional / integral control (hereinafter, PI control) _SLPC To
ω _SLPC = K _P ・ Ω _SLPER + (K _I / S) ・ ω _SLPER ... (2)
K _P : Proportional control constant
K _I : Integral control constant
S: Differential operator
It is calculated from:
[0031]
The slip rotation gain calculation unit (S106) calculates the current turbine rotation speed ω from the map shown in FIG. _TR Slip rotation gain g corresponding to _SLPC Search for and ask. FIG. 10 shows the slip rotation gain g against the turbine speed. _SLPC This is a map in which the slip rotation gain g increases as the turbine rotation speed increases. _SLPC Is set to be small.
[0032]
In the target converter torque calculation unit (S105), the turbine rotation speed ω _TR When the slip rotation command value ω _SLPC Target converter torque t for achieving _CNVC To
t _CNVC = Ω _SLPC / G _SLPC ... (3)
It is calculated from:
[0033]
The engine torque estimating unit (S108) uses the engine full performance map shown in FIG. 11 to calculate the engine torque map value t from the engine speed Ne and the throttle opening TVO. _ES , And the dynamic characteristics of the engine are added to the time constant T. _ED Is passed through the filter in the case of the first-order lag, and the estimated engine torque t _EH To
t _EH = ｛1 / (1 + T _ED ・ S)｝ ・ t _ES ... (4)
It is calculated from:
[0034]
In the target lock-up clutch engagement capacity calculation unit (S107), the engine torque estimation unit t _EH From the target converter torque t _CNVC Is subtracted from the target lock-up clutch engagement capacity t. _LU Is calculated.
[0035]
t _LU = T _EH -T _CNVC ... (5)
The lock-up clutch engagement pressure command value calculation unit (S109) calculates the current target lock-up clutch engagement capacity t from the lock-up clutch capacity map shown in FIG. _LU Lockup clutch engagement pressure command value P for achieving _LUC Search for.
[0036]
In the solenoid drive signal calculation section (S110), the actual lock-up clutch engagement pressure is determined by the lock-up clutch engagement pressure command value P _LUC Lock-up duty S _DUTY To determine.
[0037]
Next, of the control contents in the control unit 12, the slip rotation ω for determining the end of the open control, which is the point of the present invention, _SLPEND The correction method based on the change amount ΔNpri of the primary rotation will be described with reference to the flowchart of FIG.
[0038]
This is a method in which when shifting from the torque converter mode to the lock-up mode, the pressure is increased by the open control until a predetermined lock-up differential pressure is reached, and thereafter the mode is switched to the slip control to smoothly shift to the lock-up mode. This shows a method of applying the present invention in the setting of slip rotation set as a condition for switching from control to slip control.
[0039]
In step S1, the slip rotation ω for determining the end of the open control in step S9 described later. _SLPEND Is calculated, the amount of change ΔNpri of the primary rotation required when calculating the value of
[0040]
The amount of change ΔNpri is a difference between the primary rotation Npri at a preset time difference, and is calculated by the following equation when it is set to, for example, 100 ms.
[0041]
ΔNpri = current Npri−Npri before 100 ms (6)
Subsequently, in step S2, it is determined based on the throttle opening TVO, the vehicle speed v, and the like whether or not the control to be performed is slip control. If it is determined that the slip control is performed, the process proceeds to step S5. If it is determined that there is not, the process proceeds to step S3. In the present embodiment, it is determined that the slip control is started when the vehicle speed becomes 5 km / h or more.
[0042]
In step S3, it is determined in the same manner as described above whether the control to be performed is lock-up control. If it is determined that lock-up control is performed, the process proceeds to step S4, and if it is determined that lock-up control is not performed. Proceeds to step S18.
[0043]
In step S4, it is determined whether or not the lock-up control has shifted to the complete lock-up mode (the differential pressure command value is maximum). If the shift can be performed, the lock-up is completed, and the process proceeds to step S17.
[0044]
If the shift has not been completed, the process proceeds to step S5 in order to perform control to shift to the lock-up mode using slip control.
[0045]
In step S5, if the previous control state is the converter control, the process proceeds to step S6; otherwise, the process proceeds to step S8.
[0046]
In step S6, based on the flowchart of FIG. 5 described later, an initial differential pressure is set according to the current throttle opening from the map of FIG. 13 set in advance.
[0047]
Then, in step S7, a state flag (F) indicating that the boost operation by the open control is being executed is set.
[0048]
As described above, in steps S6 and S7, the preparation for starting the boosting process by the open control only at the first time when the operation region shifts from the converter mode to the slip mode or the lockup mode is performed, and the second and subsequent times are not performed.
[0049]
In step S8, the end slip rotation ω for determining whether or not the boost operation by the open control may be ended. _SLPMAP Is calculated from the map of FIG. 14 according to the current throttle opening. FIG. 14 shows the end slip rotation ω with respect to the throttle opening. _SLPMAP Is the map in which the end slip rotation ω _SLPMAP Is constant up to a predetermined throttle opening, but when it exceeds it, the end slip rotation ω is proportional to the throttle opening. _SLPMAP Is also set to be high.
[0050]
Subsequently, in step S9, a reference primary rotation change amount ΔNpri_STD with respect to the current throttle opening is calculated from the map of FIG. FIG. 16 is a map in which the reference primary rotation change amount ΔNpri_STD is set with respect to the throttle opening. The reference primary rotation change amount ΔNpri_STD is set to increase as the throttle opening increases.
[0051]
Then, a deviation ΔNpri_ERR from the actual primary rotation change amount ΔNpri is calculated.
ΔNpri_ER = ΔNpri−ΔNpri_STD (7)
And the correction amount ω corresponding to this deviation is obtained from the map of FIG. _SLPADJ Is calculated, and the map value of the open end rotation calculated in step S8 is
ω _SLPEND = Ω _SLMAP + Ω _SLPADJ ... (8)
And the slip rotation ω for determining the end of the open control actually used. _SLPEND Is calculated. FIG. 17 shows the corrected slip rotation ω with respect to the primary rotation change deviation ΔNpri_ERR. _SLPADJ Is set, and when the primary rotation change amount deviation ΔNpri_ERR is positive, the corrected slip rotation ω _SLPADJ Is negative, and when the primary rotation change amount deviation ΔNpri_ERR is negative, the corrected slip rotation ω _SLPADJ Is positive, and when the absolute value of the primary rotation change amount deviation ΔNpri_ERR increases, the corrected slip rotation ω _SLPADJ Is also set to be large.
[0052]
Note that the reference primary rotation change amount ΔNpri_STD is a primary rotation change amount on a flat road obtained in advance by simulation based on a vehicle specification table or measurement by actual photographing.
[0053]
In step S10, it is determined whether or not the boost operation by the open control is currently being executed based on the flag (F) set in step S7. If the boost operation is being executed (F = 1), the process proceeds to step S11. If the boost operation is not being performed (F = 0), the process proceeds to step S16.
[0054]
In step S11, the slip rotation ω for determination calculated in step S9 is obtained. _SLPEND And the current slip rotation ω _SLPR And compare with
ω _SLPR ≤ω _SLPEND ... (9)
In the case of, the slip rotation starts to respond to the differential pressure command by the boosting operation, it is determined that the differential pressure control can be performed, the boosting operation by the open control ends, the process proceeds to step S14, and the switching to the feedback control is performed. Perform processing.
[0055]
If expression (9) is not satisfied, it is determined that the slip rotation has not yet responded to the increase in the differential pressure command, and the process proceeds to step S12.
[0056]
In step S12, the boost amount per unit time during the open control is set in accordance with the current throttle opening from the preset map of FIG.
[0057]
FIG. 15 is a map in which the boost amount is set with respect to the throttle opening, and the boost amount is set to increase in proportion to the throttle opening.
[0058]
The unit time is equivalent to a control cycle. For example, when the open control is performed every 20 ms, the boost amount per 20 ms is set.
[0059]
In this embodiment, when the throttle opening is zero, the boost amount is set to 0.0012 MPa per 20 ms, and when the throttle opening is fully opened, the boost amount is set to 0.0035 MPa per 20 ms.
[0060]
In the following step S13, the differential pressure command value during the open control is calculated by adding the boost amount per unit time calculated in step S12 to the current differential pressure command value.
[0061]
On the other hand, in step S14, a control system initialization process is performed to end the boost operation by the open control and switch to the feedback control.
[0062]
In the initialization process, the actual slip rotation ω at the time of switching the output of the precompensator (S101) to the feedback control in the control system configuration diagram of FIG. _SLPR And the feedback compensator in the slip rotation command value calculation unit (S104) is also initialized by the slip rotation corresponding to the actual differential pressure.
[0063]
In the following step S15, the flag (F) indicating that the boost operation is being performed by the open control is cleared, and the process proceeds to step S16.
[0064]
In step S16, a feedback control calculation based on the control system configuration diagram of FIG. 3 is performed to calculate a differential pressure command value during slip control.
[0065]
For example, when performing a drive slip (in a state where the accelerator is ON and the engine speed Ne is higher than the primary speed Npri), the target slip calculation unit (S100 in FIG. 2) performs the target slip rotation ω. _SLPT Is set to 40 rpm, and 0 rpm is set when the lock-up state is set. Then, the set target slip rotation ω _SLPT The feedback control system operates so as to coincide with the following.
[0066]
As described above, the differential pressure command value at the time of the open control is set in steps S10 to S13, the switching process from the open control to the feedback control is performed in steps S10, S11, and S14 to S16. To calculate the differential pressure command value at the time of feedback control.
[0067]
Step S17 is a state where the fastening operation (complete lockup) in the lockup control is completed and the differential pressure is maintained at the maximum value. Step S18 is a state in which the release operation (unlock-up) of the lock-up clutch in the converter control is completed, and the differential pressure is kept at the minimum pressure.
[0068]
Next, an example of a method for setting the initial differential pressure in step S6 in FIG. 4 will be described with reference to the flowchart in FIG.
[0069]
First, in step S50, a preset initial differential pressure value (hereinafter, a map value) is read from the map of FIG. 13 according to the current throttle opening. FIG. 13 is a map in which an initial differential pressure is set with respect to the throttle opening. The initial differential pressure is constant from the fully closed throttle to the opening A, and the initial differential pressure is proportional to the throttle opening between the opening A and the opening B. The pressure is set to be high, and the initial differential pressure is set to be constant until the opening degree B or more is fully opened.
[0070]
In step S51, the current differential pressure is compared with the map value. If the current differential pressure is larger than the map value, the process proceeds to step S52, where the current differential pressure is selected as the initial differential pressure.
[0071]
If the current differential pressure is equal to or less than the map value, the process proceeds to step S53, and the map value is selected as the initial differential pressure.
[0072]
As a result, even when the map value set in advance becomes an operation state lower than the current differential pressure, a value equal to or higher than the current differential pressure can always be set as the initial differential pressure.
[0073]
If the primary rotation change amount ΔNpri is configured to be performed only during the slip control, a normal change amount cannot be grasped immediately after the shift to the slip control, and corresponds to the measurement period of the primary rotation change amount ΔNpri. Normally, the boosting amount cannot be set until the time for which the control mode has elapsed. However, in the present embodiment, the calculation is always performed in step S1 regardless of the current control state. Even immediately after shifting to the up control or the slip control, since the change amount ΔNpri has been calculated, the slip rotation correction amount ω in step S9 has been calculated. _SLPADJ Can be calculated normally.
[0074]
FIG. 6 shows a timing chart of the embodiment described above.
[0075]
In addition, in the engine rotation and the primary rotation in FIG. 6, the thick line indicates the case of the uphill road and the thin line indicates the case of the flat road, and both have the same throttle opening.
[0076]
After the vehicle starts, if the vehicle speed exceeds 5 km / h at time t1, it is determined that the slip control is to be started in step S2, and after step S5, an initial differential pressure for lockup is set in step S6.
[0077]
Until time t2, the lock-up control pressure is increased by open control based on the boost amount set in FIG. 15 (the boost amount increases proportionally as the throttle opening increases). Thereafter, the primary rotation speed Npri increases, and the engine rotation speed Ne decreases toward the primary rotation speed Npri.
[0078]
Actual slip rotation speed ω which is a deviation between engine rotation speed Ne and primary rotation speed Npri _SLPR When the rotation speed becomes equal to or lower than the switching speed to the feedback control, the open control is switched to the feedback control. At this time, if the vehicle is traveling on a flat road, the primary rotation speed Npri increases as shown by a thin line, and the primary rotation change amount ΔNpri at this time is substantially equal to the reference primary rotation change amount ΔNpri_STD set in FIG. Since they coincide with each other, the slip rotation speed for open control termination determination calculated in step S8 is equal to the ω set in the map of FIG. _SLPMAP It becomes.
[0079]
Then, the actual slip rotational speed ω which is a deviation from the primary rotational speed Npri as the engine rotational speed Ne decreases. _SLPR Ends slip rotation speed ω _SLPMAP At the following time t2 ', the control is switched to the feedback control.
[0080]
On the other hand, if the vehicle is traveling on an uphill road, the primary rotational speed Npri increases as shown by the thick line, and the primary rotational change ΔNpri at this time is different from the reference primary rotational change ΔNpri_STD set in FIG. The amount of change is small. That is, the increase in the primary rotation speed Npri is slower than when traveling on a flat road. For this reason, the open control end determination slip rotation speed calculated in step S8 is ω set in FIG. _SLPMAP The difference ΔNPri_ERR between the actual primary rotation change amount and the reference primary rotation change amount set in FIG. 16 is calculated, and the correction amount ω corresponding to this difference is calculated from the map in FIG. _SLPADJ Is calculated. And the slip rotation ω for determining the end of the open control actually used _SLPEND Is calculated. This end determination slip rotation ω _SLPEND Is ω _SLPMAP Since the value is larger, the open control is switched to the feedback control at time t2 earlier than time t2 '.
[0081]
As shown in the timing chart, even when the throttle opening is the same, the ascending speed of the primary rotation is slower on an uphill road than on a flat road, but it is determined that the open control has been terminated according to the variation ΔNpri of the primary rotation Npri. Slip rotation ω _SLPEND Is set so that the differential pressure does not rise too much due to the boosting by the open control.
[0082]
As described above, the following effects can be obtained by the present embodiment.
[0083]
Even when the throttle opening is the same and the rising speed of the primary rotation Npri is different, such as on a flat road and an uphill road, the slip rotation ω set as the end condition of the open control is obtained. _SLPEND Changes according to the change amount ΔNpri of the primary rotation, so that an appropriate end condition according to the operating state can be set.
[0084]
When the map value set in advance as the initial differential pressure is lower than the current differential pressure, the current differential pressure is used as the initial differential pressure. It will not be lower. Thus, it is possible to prevent the slip control from becoming impossible due to the lock-up differential pressure becoming too low.
[0085]
Since the change amount ΔNpri of the primary rotation is always calculated irrespective of the current control state, the change amount ΔNpri has already been calculated even immediately after shifting from the converter mode to the lockup control or the slip control. Therefore, the slip rotation correction amount ω _SLPADJ Can always be calculated normally.
[0086]
Next, a second embodiment will be described with reference to the flowchart of FIG.
[0087]
In the present embodiment, by maintaining a constant correction amount, the slip rotation correction amount ω associated with the slowdown of the primary rotation change amount ΔNpri due to the start of the gear shift. _SLPADJ This is a method for compensating for the excess or deficiency of the second embodiment. Since the parts except for steps S209 to S211 are the same as those in the first embodiment, description thereof will be omitted.
[0088]
First, in step S209, it is determined whether or not the primary rotation Npri is equal to or greater than a value set in advance based on vehicle specifications and a simulation using an actual vehicle.
[0089]
If it is less than the set value, in step S210, the slip rotation correction amount ω based on the primary rotation change amount ΔNpri, as in FIG. _SLPADJ Is calculated from the map, and in step S211 the slip rotation ω for determining the end of the open control is calculated. _SLPEND Is calculated.
[0090]
If it is equal to or greater than the set value, the slip rotation correction amount ω using the map _SLPADJ Is not calculated and the process proceeds to step S211 to calculate the slip rotation correction amount ω calculated last time. _SLPADJ Using the slip rotation ω for judgment _SLPEND Is calculated.
[0091]
Thereby, the primary rotation Npri becomes substantially constant by the start of the shift, and even if the primary rotation change amount ΔNpri becomes extremely small, the slip rotation correction amount ω before the start of the shift is obtained. _SLPADJ Can be held, the slip rotation correction amount ω _SLPADJ Can be prevented from deviating from the originally intended slip control start timing due to excess or deficiency.
[0092]
Note that the slip rotation correction amount ω is calculated by comparing the primary rotation Npri with the above-mentioned preset value. _SLPADJ Means for detecting a phenomenon in which the rising speed of the primary rotation Npri becomes slower with the start of the shift, such as the change amount ΔNpri of the primary rotation already calculated or the actual gear ratio with the start of the shift. If so, it can be applied as the condition in step S209.
[0093]
FIG. 8 shows a timing chart of the above embodiment.
[0094]
The portion indicated by the thick line in FIG. 8 is a case where there is a change in characteristics due to individual differences and aging of the torque converter, and the thin line represents the case as designed.
[0095]
For the reasons described above, when the generated slip rotation increases, the open control end slip rotation ω _SLPEND Becomes after the start of shifting.
[0096]
Further, in such a situation, the rising speed of the primary rotation Npri slows down with the start of the shift, and the variation ΔNpri gradually decreases and eventually becomes zero.
[0097]
Here, if the correction based on the change amount ΔNpri of the primary rotation is continued, the slip rotation for determining the end of the open control is excessively corrected and deviates from the originally intended open control end timing. , The minimum required amount of the slip rotation ω for determining the end of the open control. _SLPEND Can be set.
[0098]
As described above, in the present embodiment, the following effects can be obtained.
[0099]
If the change amount ΔNpri of the primary rotation becomes extremely small, the slip rotation correction amount ω is referred to with reference to the change amount ΔNpri before the start of the shift. _SLPADJ Is calculated, the slip rotation ω for judging the end of the open control is calculated. _SLPEND Is set based on the unnecessarily small change amount ΔNpri of the primary rotation, and it is possible to prevent deviation from the originally intended slip control start timing.
[0100]
Next, a third embodiment will be described with reference to the flowchart of FIG.
[0101]
The flowchart of FIG. 9 is the same as the procedure shown in FIGS. 4 and 7 except for steps S309 to S313, but the slip rotation correction amount ω _SLPADJ The difference is that the limiter is set when holding.
[0102]
If the primary rotation Npri is smaller than the set value in step S309, the operation is as described above. If the primary rotation Npri is equal to or larger than the set value, in step S311, the held slip rotation correction amount ω is set in step S311. _SLPADJ It is determined whether or not is within the set limit.
[0103]
If it is within the limit, in step S313, the previously calculated correction amount ω _SLPADJ Using the slip rotation ω for judgment _SLPEND Is calculated.
[0104]
If it is not within the limit, in step S312, the held correction amount ω _SLPADJ And the slip rotation ω for determination calculated in step S313 _SLPEND Deviation of the slip control start timing due to excess or deficiency of the distance.
[0105]
As described above, the following effects can be obtained by the present embodiment.
[0106]
Depending on the timing at which the holding of the correction state is started, the slip rotation ω for determining the end of the open control by the correction _SLPEND May become too large and slip control may be started from an operation region that is far from the operation region of the torque converter. However, in this embodiment, since the upper limiter is set, this situation can be avoided.
[0107]
At a low throttle opening, the slip rotation ω for determining the end of the open control by the correction _SLPEND Is too small, there is a possibility that an engagement shock will occur at the time of lock-up engagement. However, in this embodiment, since the lower limiter is set, this problem can be avoided.
[0108]
In this embodiment, the slip rotation correction amount map shown in FIG. 17 is configured as one. However, in order to adapt to various operating conditions, a dedicated map corresponding to, for example, ON / OFF of the air conditioner is prepared and switched. May be used.
[0109]
Also, the slip rotation correction amount ω _SLPADJ In the case where the required correction coefficient or correction amount can be calculated, instead of a map, a characteristic expression using a deviation or ratio between the reference primary rotation change amount ΔNpri_STD and the actual change amount ΔNpri as a variable can be used.
[0110]
When performing the correction in step S9 of FIG. 4, the slip rotation correction amount ω _SLPADJ Although the map of FIG. 17 is configured as above, the same effect can be obtained by changing this to a correction coefficient and performing correction calculation.
[0111]
Slip rotation ω set as a judgment condition for termination of open control _SLPEND At which timing is established depends on the amount of change in the engine rotation (slip rotation) and the primary rotation speed due to changes in road surface conditions, but these can be estimated in advance from vehicle specifications and torque converter characteristics. Using the precondition of (1), a correction is made so that the slip rotation becomes optimal as the open control end condition.
[0112]
It is needless to say that the present invention is not limited to the above-described embodiment, and various changes can be made within the scope of the technical idea described in the claims.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a control system according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a slip control system of the torque converter of the present invention.
FIG. 3 is a control system configuration diagram (block diagram) of the present embodiment.
FIG. 4 is a flowchart of control according to the first embodiment.
FIG. 5 is a flowchart used when setting an initial differential pressure in the first embodiment.
FIG. 6 is a timing chart showing the first embodiment.
FIG. 7 is a flowchart of control according to the second embodiment.
FIG. 8 is a timing chart of the second embodiment.
FIG. 9 is a flowchart of control according to the third embodiment.
FIG. 10 is a slip gain map.
FIG. 11 is an engine full performance map.
FIG. 12 is a lockup clutch capacity map.
FIG. 13 is an initial differential pressure setting map.
FIG. 14 is a slip rotation map for open control end determination.
FIG. 15 is a boost amount map.
FIG. 16 is a reference primary rotation change amount map.
FIG. 17 is a map of a correction amount of the slip rotation for determining the end of the open control.
[Explanation of symbols]
1 engine
2 Torque converter
2a pump impeller (input element)
2b turbine runner (output element)
2c lock-up clutch
3 automatic transmission
4 Differential gear device
5 wheels
11 Slip control valve
12 Controller
13 Lock-up solenoid
21 Throttle opening sensor
22 Impeller rotation sensor
23 Turbine rotation sensor
24 Oil temperature sensor
25 Vehicle speed sensor
26 Gear ratio calculator
27 Engine rotation sensor

Claims (9)

A lock-up clutch arranged between input and output elements of a torque converter for transmitting power from a prime mover,
Hydraulic control means for adjusting the supply hydraulic pressure to the lock-up clutch and controlling the engagement state thereof,
In a slip control device configured to control the slip rotation between the input and output elements according to the engagement state of a lock-up clutch,
Means for performing open control to increase the lock-up hydraulic pressure toward the target pressure with the start of the engagement control of the lock-up clutch;
Means for feedback-controlling the lock-up oil pressure according to the deviation between the target slip rotation and the actual slip rotation when the slip rotation corresponding to the rotation speed difference between the input element and the output element becomes equal to or less than a set value;
Means for correcting the set value based on the amount of change in the primary rotation that is equivalent to the number of revolutions of the output element. 2. The set value correction unit according to claim 1, wherein the primary rotation change amount of the flat road is set as a reference primary rotation change amount, and correction is performed according to a deviation between the reference primary rotation change amount and the primary rotation change amount of the actual vehicle. 3. Slip control device for torque converter. 3. The torque converter according to claim 2, wherein the correction unit has a correction value as a map set in accordance with a deviation between the reference primary rotation change amount and a primary vehicle rotation change amount, and calculates the correction value from the map. apparatus. 3. The torque converter control device according to claim 2, wherein the correction means calculates the correction value based on a characteristic equation using a difference or a ratio between the reference primary rotation change amount and the primary vehicle rotation change amount as a variable. 2. The torque converter control device according to claim 1, wherein the correction unit holds the correction state before the start of the shift when the primary rotation becomes substantially constant due to the shift. The correction means is configured to calculate an open control end determination slip rotation by multiplying a preset open control end slip rotation according to a throttle opening by a correction coefficient based on a primary rotation change amount. The control device for a torque converter according to claim 1, wherein a value before the start is held. The correction means is configured to calculate the open control end determination slip rotation by adding or subtracting the corrected slip rotation based on the primary rotation change amount from the open control end slip rotation set in advance in accordance with the throttle opening. The control device for a torque converter according to claim 1, wherein the control unit holds a value before the start of the shift. 8. The torque converter control device according to claim 6, wherein when the correction coefficient or the corrected slip rotation is held, an upper limit, a lower limit, or both upper and lower limits are set in the held correction state. A lock-up clutch arranged between input and output elements of a torque converter for transmitting power from a prime mover,
Hydraulic control means for adjusting the supply hydraulic pressure to the lock-up clutch and controlling the engagement state thereof,
In the slip control method, wherein the slip rotation between the input and output elements is controlled according to the engagement state of a lock-up clutch,
With the start of the lock-up clutch engagement control, open control is performed to increase the lock-up hydraulic pressure to the target pressure,
When the slip rotation corresponding to the rotation speed difference between the input element and the output element becomes equal to or less than the set value, the lock-up hydraulic pressure is feedback-controlled according to the deviation between the target slip rotation and the actual slip rotation,
A slip control method for a torque converter, wherein the set value is corrected based on a change amount of a primary rotation.

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