JP2010112411A - Slip control device of torque converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a lock-up clutch fastening force is made bigger than a control target value due to centrifugal pressure to deteriorate control accuracy during slip control of a torque converter. <P>SOLUTION: A lock-up clutch fastening pressure command value correction means which consists of a lock-up clutch fastening pressure command value correction computing part 111 and a lock-up clutch fastening pressure command value correction amount computing part 112, is contributable to slip control by correcting a command value P<SB>LUC</SB>to be reduced only by lock-up clutch fastening pressure command value correction amount Pcer required to eliminate an adverse effect on the slip control due to centrifugal pressure. The computing part 112 obtains a clutch torque increased by lock-up clutch fastening force increase amount from torque converter input/output rotation speeds Ne, Nt to be converted to lock-up clutch fastening pressure and taken as the correction amount Pcer. The computing part 111 uses the corrected lock-up clutch fastening pressure command value P<SB>LU</SB>obtained by reducing the command value P<SB>LUC</SB>only by Pcer for slip control. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a relative rotation between input / output elements of a torque converter used in an automatic transmission or the like, that is, slip rotation, even under conditions such as when the vehicle starts where fine slip control is required. The present invention relates to a slip converter for a torque converter that can be controlled with high accuracy while preventing adverse effects due to centrifugal pressure.

Since the torque converter performs power transmission between the input / output elements via the fluid, it performs a torque fluctuation absorbing function and a torque increasing function, but has a poor transmission efficiency.
For this reason, a lock-up type torque converter that directly connects (locks up) the input / output elements of the torque converter with a lock-up clutch under a driving condition that does not require the torque fluctuation absorbing function and the torque increasing function is today. It is used a lot.

  However, in the on / off control, whether the torque converter is in a lockup state in which the input / output elements are directly connected or in a converter state in which only the fluid transmission is performed by releasing the lockup clutch, The region that limits the slip rotation of the converter is narrow, and it is not possible to expect a sufficient improvement in transmission efficiency.

Therefore, the lock-up clutch is set to a so-called half-clutch state, and a slip control region for limiting the slip rotation of the torque converter is set in such a manner that the required minimum torque fluctuation absorbing function and torque increasing function are ensured. And
As a result, many slip control techniques for torque converters have been proposed that can limit slip rotation to even lower vehicle speeds.

  In the slip control of the torque converter, the above-mentioned minimum necessary torque fluctuation absorbing function and torque are usually obtained by adjusting the lockup clutch engagement capacity by controlling the differential pressure across the lockup clutch (lockup clutch engagement pressure). The torque converter is slip controlled so as to obtain an increasing function.

As a slip control technique for that purpose, for example, the one described in Patent Document 1 has been known.
In this slip control technique, the target engagement pressure of the lockup clutch for realizing the engagement capacity of the lockup clutch necessary for changing the actual slip rotation of the torque converter to the target slip rotation is obtained in advance by experiments or the like. Search from the relationship map between the lockup clutch engagement pressure and the lockup clutch engagement capacity,
The engagement pressure of the lockup clutch is electronically controlled so as to coincide with the target engagement pressure.
JP 2006-029444 A

  By the way, when the torque converter is slip controlled with the output speed of the torque converter being zero as in the case of starting the vehicle, the slip amount of the torque converter increases, and centrifugal force acts on the hydraulic oil in the torque converter. The generated centrifugal pressure has the following adverse effects on the slip control.

In other words, when the vehicle starts, the torque converter input rotation speed (impeller rotation speed) is significantly higher than the output rotation speed (turbine rotation speed), and the slip amount of the torque converter increases.
Due to the magnitude relationship, the pressure gradient on the release pressure side that urges the lockup clutch in the releasing direction becomes steeper than the pressure gradient on the apply pressure side that urges the lockup clutch in the fastening direction.
Centrifugal pressure generates a force that urges the lockup clutch in the direction of engagement due to the difference in pressure gradient, and makes the engagement force (engagement capacity) of the lockup clutch larger than the control target value by the urging force. Therefore, there arises a problem that the accuracy of the slip control is lowered.

Thus, when the engagement force (engagement capacity) of the lock-up clutch becomes larger than the control target value by the above urging force,
The fear that the slip rotation of the torque converter falls so as to deviate downward from the target slip rotation and, in some cases, the engine stall due to a significant decrease in the input speed of the torque converter cannot be eliminated.

As a countermeasure, it is conceivable to prevent the slip rotation of the torque converter from decreasing below the target slip rotation by feedback control.
However, in slip control at the time of vehicle start that requires delicate slip control, the feedback control response is made to be quite high (increase the control gain) in order to reliably eliminate the above-mentioned adverse effects due to centrifugal pressure. Need,
For this reason, the slip control system cannot be prevented from becoming unstable, and another problem arises that stable slip control cannot be expected.

  The present invention proposes a slip converter for a torque converter, which requires fine slip control and can eliminate the influence of centrifugal pressure even when the vehicle is started, which is easily affected by centrifugal pressure as described above. Therefore, it aims to solve the above problems.

For this purpose, a slip converter for a torque converter according to the invention is constructed as described in claim 1.
First, a slip control device as a premise of the present invention is used in a torque converter that transmits rotation from a prime mover, and adjusts actual slip rotation between torque converter input / output elements by lockup clutch engagement control.

The present invention provides the following lock-up clutch engagement pressure command value correction means for the torque converter slip control device.
The lockup clutch engagement pressure command value correcting means is configured to change the command value of the lockup clutch engagement pressure during an operation that adversely affects the slip control due to the centrifugal pressure generated by the centrifugal force acting on the hydraulic oil in the torque converter. This is to compensate for the decrease.

According to the slip control device of the present invention,
In order to correct the command value of the lock-up clutch engagement pressure in the decreasing direction during the operation in which the centrifugal pressure biases the lock-up clutch in the engagement direction and adversely affects the slip control of the torque converter,
The force applied in the lockup clutch engagement direction due to the centrifugal pressure is canceled or reduced by correcting the decrease in the lockup clutch engagement pressure command value. Can be reduced at least.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
[Constitution]
FIG. 1 shows a control system of a torque converter provided with a slip control device according to an embodiment of the present invention, wherein 1 is an engine as a prime mover, and 2 is a torque converter.

The torque converter 2 is connected between the engine 1 and an automatic transmission (not shown).
A pump impeller 2a as an input element driven by the engine 1, a turbine runner 2b as an output element coupled to the input shaft of the automatic transmission, and a lockup clutch 2c directly connecting between the pump impeller 2a and the turbine runner 2b A so-called lock-up torque converter.

The fastening force of the lock-up clutch 2c is the applied pressure Pa before and after that. And release pressure Pr Determined by the differential pressure between them (lock-up clutch engagement pressure)
Apply pressure Pa Release pressure Pr If not, the lock-up clutch 2c is released and does not directly connect between the pump impeller 2a and the turbine runner 2b,
The torque converter 2 is caused to function to perform fluid transmission in a converter state in which slip restriction is not performed.

Apply pressure Pa Release pressure Pr Higher than that, the lockup clutch 2c is fastened with a force corresponding to the differential pressure,
The torque converter 2 is caused to function in a slip control state in which slip restriction is performed according to the engagement force (lockup clutch engagement capacity) of the lockup clutch 2c.
When the differential pressure becomes larger than the set value, the lockup clutch engagement capacity increases, so that there is no relative rotation between the pump impeller 2a and the turbine runner 2b, and the torque converter 2 is operated in a lockup state with zero slip rotation. To function in the same way.

In the slip control state described above, the torque converter 2 has a converter torque due to fluid transmission caused by relative rotation (slip rotation) between the pump impeller 2a and the turbine runner 2b, and torque caused by mechanical transmission by the lockup clutch 2c (lock Torque corresponding to the sum of the up clutch engagement capacity) is transmitted, and the torque corresponding to the sum is equal to the engine output torque.
Therefore, if the converter torque is subtracted from the engine output torque, the lockup clutch engagement capacity can be obtained.
Note that the converter torque can be obtained in advance for each torque converter as a relationship between the slip rotation of the torque converter and the turbine rotation speed from the transmission performance of the torque converter.

Here, the relationship among the converter torque, slip rotation, and turbine rotation speed, which can be obtained in advance from the transmission performance of the torque converter, will be described.
As illustrated in FIG. 3, when the ratio of the slip rotation ω _SLP to the converter torque T _CNV is defined as the slip rotation gain g _SLP , the slip rotation gain g _SLP is expressed by the following equation.
g _SLP = ω _SLP / T _CNV (1)
Then, Such as when defining the slip rotation gain g _SLP, the turbine rotation speed ωt As the slip rotation gain g _SLP is illustrated in solid lines in FIG. It was confirmed that it changed according to.

Note by the torque converter slip rotation gain g _SLP turbine speed ωt 3 It may be a steady slip rotation gain that does not change depending on.

In this embodiment, the applied pressure Pa is applied to perform slip control of the torque converter based on the above principle. And release pressure Pr The slip control system that determines the following is configured as follows.
Slip control valve 11 in FIG. 1, apply pressure Pa according to the signal pressure P _S from the lock-up solenoid 13 is duty-controlled by the transmission controller 12 And release pressure Pr Is to decide
The slip control valve 11 and the lockup solenoid 13 are well known as shown in FIG.

That is, the lock-up solenoid 13 has a constant pilot pressure Pp Signal pressure Ps as the solenoid drive duty D from controller 12 increases To be high.
On the other hand, the slip control valve 11 has the above signal pressure Ps. And the released release pressure Pr In one direction, and the spring force of the spring 11a and the feedback pressure Pa applied in the other direction. Receive
With increasing signal pressure P _S, the apply pressure Pa And release pressure Pr Differential pressure between (Pa −Pr The engagement pressure of the lock-up clutch 2c represented by) is continuously changed from a negative value to a positive value as indicated by the scale on the horizontal axis of FIG.

Here, lock-up clutch engagement pressure (Pa −Pr ) Negative value is Pa <Pr Means that the lockup clutch 2c is released and the torque converter 2 is put into the converter state.
Conversely, the lock-up clutch engagement pressure (Pa −Pr ) Is positive, the engagement capacity T _LU of the lock-up clutch 2c increases as the value increases as shown in FIG. 10, greatly limiting the slip rotation of the torque converter 2, and finally the torque converter 2 This means that the lock-up state is established by completely engaging the clutch 2c.

In the transmission controller 12, as shown in FIG.
A signal from the power supply voltage sensor 14 for detecting the power supply voltage Vb of the lockup solenoid 13;
A signal from the impeller rotation sensor 15 for detecting the rotational speed ωi (rad / s) of the pump impeller 2a;
A signal from the turbine rotation sensor 16 for detecting the rotation speed ωt (rad / s) of the turbine runner 2b;
A signal from the output shaft rotation sensor 17 for detecting the output shaft rotation speed ωo of the automatic transmission (from which the vehicle speed VSP is calculated);
A signal from the throttle opening sensor 18 for detecting the throttle opening TVO of the engine 1,
Hydraulic oil temperature TEMP of torque converter 2 (automatic transmission) And a signal from the oil temperature sensor 19 for detecting.

  The transmission controller 12 further communicates with the engine controller 21 to receive engine information such as the engine speed Ne (rpm), the engine speed ωe (rad / s), and the estimated engine torque Te. To do.

[Slip control]
The transmission controller 12 determines the drive duty D of the lock-up solenoid 13 based on the above input information and performs the slip control of the torque converter 2 by calculating along the functional block diagram shown in FIG. .
The drive duty D is supplied to the lock-up solenoid 13 shown in FIG. 1, and slip control of the torque converter 2 described in detail below is performed by the duty drive.

The calculation performed by the transmission controller 12 along the functional block diagram shown in FIG. 2 will be described below.
The target slip rotation calculating unit 101 calculates the vehicle speed VSP, the throttle opening TVO, the hydraulic oil temperature TEMP, and the transmission gear ratio i _P (the ratio of the transmission input shaft rotation speed ωi to the transmission output shaft rotation speed ωo). ), The slip rotation of the torque converter that can suppress the engine rotation is set as the target slip rotation ω _SLPT within a range in which torque fluctuations and noise are not generated.

The target slip rotation ω _SLPT of the torque converter thus obtained is directed to the pre-compensator 102.
The precompensator 102 includes a reference model (compensation filter) 102A having a transfer function G _R (s) that can obtain a target slip control response intended by the designer, and a transfer function G _M (s). Feedforward compensator (compensation filter) 102B.
However, it is assumed that the transfer function G _M (s) of the feedforward compensator (compensation filter) 102B is expressed by the following equation.
G _M (s) = G _R (s) / P (s) (2)
P (s): Transfer function that models the slip rotating part to be controlled

The target slip rotation ω _SLPT is passed through these reference model 102A and feedforward compensator 102B, respectively.
By passing the target slip rotation ω _SLPT through the _reference model 102A, the first target slip rotation correction value ω _SLPTC1 is calculated,
ω _SLPTC1 ＝ G _R (s) × ω _SLPT・ ・ ・ (3)
The second target slip rotation correction value ω _SLPTC1 is calculated by passing the target slip rotation ω _SLPT through the feedforward compensator 102B.
_{ω SLPTC2 = G M (s)} × ω SLPT ··· (4)

The actual slip rotation calculation unit 103 calculates the actual slip rotation ω _SLPR of the torque converter 2 by subtracting the turbine rotation speed ωt of the turbine runner 2b from the impeller rotation speed ωi of the pump impeller 2a.
The impeller rotational speed ωi is equivalent to the engine rotational speed ωe, and the turbine rotational speed ωt is equivalent to the input rotational speed of the transmission.

In slip rotation deviation computing unit 104, a first target slip rotation correction value omega _SLPTC1, slip rotational deviation omega _SLPER between the actual slip rotation omega _SLPR,
ω _SLPER = ω _SLPTC1 − ω _SLPR (5)
Calculated by

In the slip rotation command value calculation unit 105, first, the slip rotation deviation ω _SLPER is passed through the feedback compensator 105A constituted by a PI controller (P: proportional control, I: integration control), and this slip rotation deviation ω _{SLPER is passed.} First slip rotation command value ω _SLPC1 for eliminating the _above is obtained.
ω _SLPC1 ＝ Kp ・ ω _SLPER ＋ （Ki / s) ・ ω _SLPER
＝ G _CNT (s) × ω _SLPER・ ・ ・ (6)
Kp: Proportional control constant
Ki: integral control constant s: differential operator Next, the above-described second target slip rotation correction value ω _SLPTC2 is added to the first slip rotation command value ω _SLPC1 to obtain a final slip rotation command value ω. _{Calculate SLPC} .
ω _SLPC = ω _SLPC1 + ω _SLPTC2 (7)

In the slip rotation gain computing unit 106, based on the map corresponding to FIG. 3, the current turbine speed .omega.t, determined by searching the current slip rotation speed gain g _SLP.
The target converter torque calculation unit 107 calculates the target converter torque T _CNVC for achieving the slip rotation command value ω _SLPC based on the current turbine rotation speed ωt.
T _CNVC = ω _SLPC / g _SLP ... (8)
Calculated by

The engine torque estimation unit 108 first uses the engine performance diagram illustrated in FIG. And the engine output torque steady value Tes from the throttle opening TVO,
Next, the engine torque steady value Tes is filtered through a filter whose time constant T _ED corresponds to the dynamic delay of the engine, and the engine torque Te after the filter processing is estimated as an engine torque closer to the actual value. To do.
Te = [1 / (1 + T _ED · s)] Tes (9)

In the target lock-up clutch engagement capacity calculation unit 109, the target converter torque calculation unit 107 calculates the slip converter command value (ω _SLPC ) target converter torque T _CNVC obtained by the equation (8), and the engine estimated as described above. Target lock-up clutch engagement capacity T _LU from torque Te
T _LU = Te−T _CNVC ... (10)
Calculated by

Lockup clutch engagement pressure command value calculating section 110, based on the lockup clutch torque capacity map corresponding to FIG. 5, the current target lockup clutch engagement capacity T _LU, achieve this goal lockup clutch engagement capacity T _LU The lock-up clutch engagement pressure command value P _LUC is searched for.
Incidentally in this embodiment, without using the lock-up clutch engagement pressure command value P _LUC as the slip control of the torque converter, in order to achieve the object of the present invention, the lock-up clutch engagement pressure command value P _LUC It contributes to slip control by correcting as follows.

For this purpose, as shown in FIG. 2, a lockup clutch engagement pressure command value correction calculation unit 111 and a lockup clutch engagement pressure command value correction amount calculation unit 112 are provided.
The lock-up clutch engagement pressure command value correction amount calculation unit 112 corrects the lock-up clutch engagement pressure command value necessary to eliminate the adverse effects on the slip control caused by the centrifugal pressure from the engine speed Ne and the turbine speed Nt. The quantity Pcer is determined as follows.

Here, adverse effects on the slip control due to the centrifugal pressure will be considered.
When the torque converter output rotational speed (turbine rotational speed) Nt is zero and the torque converter 2 is slip-controlled as when the vehicle starts, the input rotational speed (impeller rotational speed) of the torque converter becomes the output rotational speed (turbine rotational speed). ), The slip amount of the torque converter increases,
For this reason, the centrifugal pressure generated by the centrifugal force acting on the hydraulic oil in the torque converter generates a force that urges the lock-up clutch 2c in the fastening direction for the following reason.

That is, the magnitude relationship of the rotational speed that the input rotational speed (impeller rotational speed) of the torque converter becomes higher than the output rotational speed (turbine rotational speed) is the distribution of the applied pressure Pa and the release pressure Pr with respect to the lockup clutch 2c. Nothing like that shown in Figure 6,
The pressure gradient on the release pressure (Pr) side that urges the lock-up clutch 2c in the release direction (right direction in FIG. 6) causes an apply pressure (that urges the lock-up clutch 2c in the engagement direction (left direction in FIG. 6)). It becomes steeper than the pressure gradient on the Pa side.
Centrifugal pressure generates a force that urges the lock-up clutch 2c in the direction of engagement (left direction in FIG. 6) due to the difference in pressure gradient, and the engagement force (engagement capacity) of the lock-up clutch 2c from the control target value. Is also increased by the amount of the urging force, which adversely affects the accuracy of slip control.

Thus, when the engagement force (engagement capacity) of the lockup clutch 2c becomes larger than the control target value by the above urging force,
The slip rotation ω _SLPR of the torque converter 2 falls so as to deviate below the target slip rotation ω _SLPT , and in some cases, the concern that engine stall may occur due to a significant decrease in the torque converter input rotation speed (engine speed) is also eliminated. I ca n’t.

When calculating the lockup clutch engagement pressure command value correction amount Pcer necessary for eliminating the adverse effect on the slip control due to the centrifugal pressure, the lockup clutch engagement pressure command value correction amount calculation unit 112,
First, the centrifugal pressure urges the lock-up clutch 2dc in the direction of engagement by calculating the following equation using the engine speed Ne, which is the torque converter input speed, and the turbine speed Nt, which is the torque converter output speed. Thus, the lockup clutch torque correction amount Tcer necessary to cancel the adverse effect on the slip control due to the centrifugal pressure is obtained by canceling the generated clutch torque.
Tcer = {(Ne + Nt) / 2} ² −Nt2 (11)

The lockup clutch engagement pressure command value correction amount calculation unit 112 calculates the lockup clutch torque correction amount Tcer calculated by the above equation (11) and the lockup clutch engagement pressure command necessary to realize this clutch torque correction amount. Based on the map corresponding to the characteristic diagram illustrated in FIG. 7 showing the relationship with the value correction amount Pcer, from the lockup clutch torque correction amount Tcer,
The lockup clutch engagement pressure command value correction amount Pcer necessary for realizing the clutch torque correction amount and eliminating the adverse effect on the slip control due to the centrifugal pressure is searched.

Note lockup clutch engagement pressure command value correcting characteristic line according to the amount of FIG. 7, the lock-up clutch engagement pressure command value P _LUC in starting early, actual lockup clutch engagement pressure at around the lock-up clutch (Pa-Pr) The differences are summarized based on equation (11).

Further, in FIG. 7, while the lockup clutch torque correction amount Tcer is less than the set value Tcer1, the lockup clutch engagement pressure command value correction amount Pcer is set to 0,
The set value Tcer1 is made to correspond to the lower limit value of the lockup clutch torque correction amount Tcer in which the adverse effect due to the centrifugal pressure becomes a problem.
Accordingly, the speed ratio e = Nt / Ne of the torque converter increases so that useless correction never performed in becoming not region by the lock-up clutch engagement pressure command value P _LUC problematic adverse effects of centrifugal pressure.

Lockup clutch engagement pressure command value correction operation section 111, a lock-up clutch engagement pressure command value P _LUC lowered corrected by the lock-up clutch engagement pressure command value correction amount Pcer by the following formula, corrected lockup clutch engagement pressure command _{Find the} value _PLU .
_{P LU = P LUC -Pcer ··· (} 12)

The solenoid drive signal calculation unit 113 determines a lockup solenoid drive duty D for setting the actual lockup clutch engagement pressure (Pa−Pr) to the corrected lockup clutch engagement command value _PLU ,
The drive duty D and instructs the lock-up solenoid 13 of FIG. 1, to match the torque capacity to a target lockup clutch tightening capacity T _LU, performs slip control for realizing the target slip rotational omega _SLPT.

[Effect]
By the way, the above-described slip control device of this embodiment is
Do not use the lock-up clutch engagement pressure command value P _LUC obtained by the lock-up clutch engagement pressure command value calculation unit 110 as it is for slip control of the torque converter.
While the lockup clutch torque correction amount Tcer is equal to or greater than the set value Tcer1, that is, during the operation in which the centrifugal pressure biases the lockup clutch 2c in the engagement direction and adversely affects the slip control of the torque converter 2.
The lockup clutch engagement pressure command value P _LUC is corrected to decrease by the lockup clutch engagement pressure command value correction means (the lockup clutch engagement pressure command value correction calculation unit 111 and the lockup clutch engagement pressure command value correction amount calculation unit 112). To use the corrected lockup clutch engagement pressure command value _PLU for slip control,
The force applied in the lockup clutch engagement direction due to the centrifugal pressure is canceled or reduced by correcting the decrease in the lockup clutch engagement pressure command value. Can be at least mitigated.

Such an effect will be described in detail with reference to FIGS. 8 and 9 both start at a constant accelerator pedal depression amount (throttle opening TVO) at an instant t1 from the stopped state, and then target slip rotation ω so as to suppress the engine speed increase. FIG. 5 is an operation time chart when _SLPT is set and the torque converter 2 is locked up when the vehicle speed VSP reaches a predetermined vehicle speed.

Conventionally, as shown in FIG. 8, the lock-up clutch is set so that the actual slip rotation ω _SLPR follows the standard response slip rotation ω _SLPTC1 immediately after the start t1 when the accelerator pedal is depressed to make the throttle opening TVO constant. The engagement pressure command value P _LUC is controlled and the lockup clutch 2c is slip-engaged,
Because the lockup clutch engagement pressure command value P _LUC is used for slip control as it is, the actual lockup clutch engagement pressure (Pa-Pr) is more centrifugal than the lockup clutch engagement pressure command value P _LUC due to the effect of centrifugal pressure. Increased by the amount of force applied in the clutch engagement direction.

For this reason, the engagement force (engagement capacity) of the lock-up clutch 2c becomes larger than the control target value by the above urging force,
The slip rotation ω _SLPR of the torque converter 2 falls below the standard response slip rotation ω _SLPTC1 so as to deviate downward as shown in FIG. 8, and the engine speed Ne is reduced due to the drastic decrease in the input speed of the torque converter. As shown in FIG. 8, it is significantly lower than the target engine speed Ne *, which may cause engine stall in some cases.

On the other hand, according to the slip control of this embodiment, as shown in FIG. 9, instead of the lock-up clutch engagement pressure command value P _LUC (see FIG. 8), the centrifugal control is performed so that the adverse effect due to the centrifugal pressure is eliminated. for use the corrected lockup clutch engagement pressure command value P _LU that only correction for decreased pressure (PCE R) to slip control,
Even if the actual lock-up clutch engagement pressure (Pa-Pr) is added to the centrifugal pressure (PCE R), without higher than the lock-up clutch engagement pressure command value P _LUC shown in FIG. 8, the lock-up clutch engagement It almost matches the pressure command value P _LUC .

Therefore, the engagement force (engagement capacity) of the lockup clutch 2c does not become larger than the control target value corresponding to the lockup clutch engagement pressure command value _PLUC .
As shown in FIG. 9, the slip rotation ω _SLPR of the torque converter 2 can be made to follow the _reference response slip rotation ω _SLPTC1 well.
Accordingly, the slip rotation ω _SLPR of the torque converter 2 does not fall so as to deviate greatly downward from the normative response slip rotation ω _SLPTC1 , and the engine speed Ne follows the target engine speed Ne * well as shown in FIG. Can alleviate concerns about engine stalls.

In the present embodiment, the lock-up clutch engagement pressure command value P _LUC, only correction for decreased centrifugal pressure (PCE R) with the corrected lockup clutch engagement pressure command value P _LU to fastening direction force due to the centrifugal pressure is canceled The above-mentioned effects can be obtained.
The decrease correction amount does not necessarily have to be a centrifugal pressure component (Pcer) that cancels the fastening direction force due to the centrifugal pressure. Even if the correction amount is smaller than this, the above-described effect is achieved according to the correction amount. Needless to say, it can be played.

In this embodiment, the lockup clutch torque increase amount due to the centrifugal pressure is obtained from the engine rotational speed Ne (torque converter input rotational speed) and the turbine rotational speed Nt (torque converter output rotational speed). The lock-up clutch torque correction amount Tcer necessary to offset the adverse effects of the lock-up clutch torque correction amount Tcer is converted into the lock-up clutch engagement pressure command value correction amount Pcer. to decrease correcting the command value P _LUC,
The lock-up clutch engagement pressure command value correction amount Pcer for achieving the above-described effects uses the existing engine speed Ne (torque converter input speed) signal and turbine speed Nt (torque converter output speed) signal. This is very advantageous in terms of cost in combination with the fact that it is obtained by a simple calculation and no additional sensor is required.

In calculating the lockup clutch torque increase amount (lockup clutch engagement pressure command value correction amount Pcer) due to the centrifugal pressure described above, the input speed Ne and output speed Nt of the torque converter are calculated as in the above equation (11). The lock-up clutch torque increase amount (lock-up clutch engagement pressure command value correction amount Pcer) due to the centrifugal pressure is obtained from the difference between the square value of the intermediate value and the square value of the torque converter output speed Nt. Good.
In this case, the amount of increase in the lockup clutch torque due to the centrifugal pressure (lockup clutch engagement pressure command value correction amount Pcer) can be accurately obtained, and the above-described effects can be achieved more reliably.

In this embodiment, the change characteristic of the lockup clutch engagement pressure command value correction amount Pcer with respect to the lockup clutch torque correction amount Tcer is determined as shown in FIG. 7, and the lockup clutch torque correction amount Tcer is set to the set value Tcer1 (centrifugal The lockup clutch engagement pressure command value P _LUC is reduced by setting the lockup clutch engagement pressure command value correction amount Pcer to 0 when the adverse effect due to pressure is less than the lower limit value of the lockup clutch torque correction amount. Because correction was prohibited,
Torque converter speed ratio e = Nt / Ne is large, and there is no useless correction of lockup clutch engagement pressure command value P _{LUC in} an area where centrifugal pressure does not adversely affect it. It is possible to avoid adverse effects caused by correction of the pressure command value P _LUC .

It is a system diagram which shows the control system of the torque converter provided with the slip control apparatus which becomes one Example of this invention. FIG. 2 is a functional block diagram related to a slip controller of the transmission controller in FIG. It is a characteristic diagram which shows the relationship of the slip rotation gain with respect to the turbine rotational speed of a torque converter. It is an engine whole performance characteristic diagram used for engine torque estimation. It is a characteristic diagram which shows the relationship between the lockup clutch fastening pressure of a torque converter, and a lockup clutch fastening capacity. FIG. 6 is a pressure distribution diagram showing pressure distributions of apply pressure and release pressure acting on the lockup clutch when the vehicle starts. FIG. 5 is a characteristic diagram showing a relationship between a lock-up clutch torque correction amount necessary for canceling the clutch torque due to centrifugal pressure and a lock-up clutch engagement pressure command value correction amount necessary for realizing the clutch torque correction amount. is there. It is an operation | movement time chart which shows the conventional slip control at the time of vehicle start. FIG. 9 is an operation time chart when the slip control according to the embodiment of FIG. 2 is performed under the same conditions as FIG.

Explanation of symbols

1 engine (motor)
2 Torque converter
2a Pump impeller (input element)
2b Turbine runner (output element)
2c Lock-up clutch
11 Slip control valve
12 Transmission controller
13 Lock-up solenoid
14 Power supply voltage sensor
15 Impeller rotation sensor
16 Turbine rotation sensor
17 Output shaft rotation sensor
19 Oil temperature sensor
21 Engine controller
101 Target slip rotation calculator
102 Precompensator
103 Actual slip rotation calculator
104 Slip rotation deviation calculator
105 Slip rotation command value calculator
106 Slip rotation gain calculator
107 Target converter torque calculator
108 Engine torque estimator
109 Target lock-up clutch engagement capacity calculator
110 Lock-up clutch engagement pressure designation area calculation section
111 Lock-up clutch engagement pressure command value correction calculation section (lock-up clutch engagement pressure command value correction means)
112 Lockup clutch engagement pressure command value correction amount calculation unit (lockup clutch engagement pressure command value correction means)
113 Solenoid drive signal calculator

Claims (6)

Used for torque converter that transmits rotation from prime mover,
In the slip control device for adjusting the actual slip rotation between the input and output elements of the torque converter by controlling the engagement pressure of the lockup clutch,
Lockup clutch engagement pressure command value correction means for reducing the command value of the lockup clutch engagement pressure during operation that adversely affects the slip control due to centrifugal pressure generated by the centrifugal force acting on the hydraulic oil in the torque converter. A slip control device for a torque converter, comprising: In the slip control device of the torque converter according to claim 1,
The lockup clutch engagement pressure command value correcting means is
A slip control device for a torque converter, wherein the lock-up clutch engagement pressure command value is reduced by a pressure necessary to prevent a drop in torque converter slip rotation due to the centrifugal pressure. In the slip converter of the torque converter according to claim 1 or 2,
The lockup clutch engagement pressure command value correcting means is
The lock-up clutch torque correction amount obtained from the centrifugal pressure, which is obtained from the input speed and output speed of the torque converter, is used as the lock-up clutch torque correction amount, and this lock-up clutch torque correction amount is converted into the lock-up clutch engagement pressure correction amount. Then, the slip control device for a torque converter is characterized in that the lockup clutch engagement pressure command value is reduced by this conversion correction amount. In the slip control device of the torque converter according to claim 3,
The lockup clutch engagement pressure command value correcting means is
The lockup clutch torque increase amount due to the centrifugal pressure is obtained from the difference between the square value of the intermediate value of the input speed and the output speed of the torque converter and the square value of the torque converter output speed. Torque converter slip control device. In the slip converter of the torque converter according to claim 3 or 4,
The lockup clutch engagement pressure command value correcting means is
A slip control device for a torque converter, wherein when the lockup clutch torque correction amount is less than a set value, a decrease in the lockup clutch engagement pressure command value is prohibited. In the torque converter slip control device according to claim 5,
A slip control apparatus for a torque converter, wherein a set value relating to the lock-up clutch torque correction amount is made to correspond to a lower limit value of the lock-up clutch torque correction amount in which an adverse effect due to the centrifugal pressure becomes a problem.

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