JPH04113071A - Locking force control device for fluid coupling - Google Patents

Abstract

PURPOSE:To effectively reduce the generation of shock and improve the responsiveness of locking force control by providing an initial control quantity correcting means for correcting the initial control quantity at the time of starting locking force increasing control according to a measured time. CONSTITUTION:A locking force control unit for a fluid coupling having a lockup means 5 for directly connecting the input and output shafts of a fluid coupling and controlling the locking force of the lockup means 5 to a set value by a predetermined set control area is aimed. A locking force control means 30 for gradually increasing the locking force of the lockup means 5 from an initial locking force corresponding to an initial control quantity and a time measuring means 31 for measuring the time required until the locking force of the lockup means 5 controlled thereby becomes the set value in the set control area are provided. Thus, according to the time measured by the time measuring means 31, the initial control quantity at the time of starting the locking force increasing control in the locking force control means 30 is corrected by an initial control quantity correcting means 32.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in controlling the fastening force of a fluid coupling by adjusting the rotational speed difference between the input and output shafts of the fluid coupling using a lock-up clutch.

(Prior Art) Conventionally, a lock-up clutch that directly connects the input and output shafts of a fluid coupling is provided as a fastening force control device for a fluid coupling, as disclosed in Japanese Utility Model Application Publication No. 57-150655. When controlling the clutch to the engagement side in the above range, the control duty rate for the solenoid valve for controlling the operation of the clutch is gradually increased from around zero value, so that the lock-up clutch is gradually engaged and the lock-up clutch is engaged. It is known that the shock caused by the fastening operation is reduced.

(Issue 8 to be solved by the invention) However, in the conventional method described above, since the control duty rate for the solenoid valve gradually increases from around zero value, although the shock can be effectively reduced, it takes a long time to complete the engagement. The disadvantage is that it takes time and responsiveness is reduced.

Therefore, for example, it is possible to set the initial control duty rate to be output to the solenoid valve relatively large in order to reduce the shock and achieve good response. Even if the settings are good, there will be drawbacks such as large variations due to engine output torque and the characteristics of the solenoid valve, such as the tightening operation being too early and causing a shock, or conversely being too slow and reducing responsiveness. .

The present invention has been made in view of the above, and its purpose is to perform the engagement operation with less shock, in a short time, and with good responsiveness when the lock-up clutch is fully engaged or engaged to a set engagement force. The goal is to always ensure that

(Means for Solving the Problems) In order to achieve the above object, the present invention sequentially corrects the initial control amount of the lock-up clutch engagement force control.

In other words, the specific solution of the present invention, as shown in FIG. The subject is a fastening force control device for a fluid coupling that controls the force to a set value. and a fastening force control means 30 for gradually increasing the fastening force of the lockup means 5 from the initial fastening force corresponding to the initial control amount when the lockup means 5 shifts from the open state to the setting control area; a time measuring means 31 for measuring the time until the fastening force of the lockup means 5 controlled by the control means 30 reaches a set value in the set control region; The present invention is configured to include an initial control amount correction means 32 for correcting the initial control amount at the start of the fastening force increase control in the control means 30.

(Function) With the above configuration, in the present invention, each time the locking force of the lockup means 5 is controlled to the set value after entering the setting control area,
The time it takes for the fastening force to reach the set value is measured, and if this time is long, the initial control amount is repeatedly corrected to increase the initial fastening force, so the next fastening operation will be shorter than the previous one. It is concluded over time and responsiveness gradually improves.

On the other hand, when the time it takes for the fastening force to reach the set value is short and shock is likely to occur, the initial control amount is repeatedly corrected to weaken the initial fastening force, so the next time it will take a longer time than the previous time. The shock can be effectively reduced.

(Effects of the Invention) As explained above, according to the fastening force control device for a fluid coupling of the present invention, each time the fastening force of the lockup means is controlled in the setting control region, the fastening force reaches the set value. Since the initial control amount for the fastening force control is successively corrected according to the time required for the lockup to be applied, the initial control amount can be set to an appropriate value to effectively reduce the shock caused by the fastening operation to the set fastening force of the lockup means. It is possible to improve the responsiveness of the fastening force control of the means.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows the internal structure and hydraulic circuit of the main parts of the automatic transmission. In the figure, 1a is an engine output shaft, 2 is a torque converter as a fluid coupling that transmits the power of the engine output shaft 1a to a subsequent stage, and the torque converter 2 is
Pump 2 connected to engine output shaft 1a and rotating integrally
a, and a turbine 2b disposed facing the pump 2a.
and a stem 2C disposed between the two to increase torque, and the front end of the converter output shaft 2d is connected to the turbine 2b, and the converter output shaft 2d is connected to the front end of the converter output shaft 2d.
A transmission gear mechanism (not shown) having, for example, four forward speeds and one reverse speed is connected to the rear end portion.

In addition, in the torque converter 2, a lock is provided between the pump 2a and the converter case 3 in front of the pump 2a to directly connect the input/output shaft of the torque converter 2, that is, the engine output shaft 1a and the converter output shaft 2d. An up clutch 5 is arranged. The lock-up clutch 5 has a fastening side space 5 formed behind it.
It is pressed in the fastening direction (to the left in the figure) by the hydraulic pressure in a, and conversely in the opening direction by the hydraulic pressure in the open side space 5b formed in the front.

Further, the illustrated hydraulic circuit A has a function of engaging and disengaging the lock-up clutch 5, and controlling the engagement force. In the hydraulic control circuit A, 10 is a lock-up control valve that controls the engagement force of the lock-up clutch 5.

The control valve 10 is connected to an engagement pressure passage 11 that communicates with the engagement side space 5a of the lock-up clutch 5, and an opening pressure passage 12 that communicates with the release side space 5b. A line pressure passage 13 for supplying hydraulic pressure to the line pressure passage 12 is connected in communication with the drain boat 10c. Further, the right side of the spool 10a of the control valve 10 is connected to the open pressure passage 1 through the passage 14.
2, and the opening pressure acts on it. On the other hand, the spool 10a
On the left side of the figure, a spring 10b is compressed to urge the spool 10a to the right in the figure, and a pilot pressure passage 15 is connected thereto. A duty solenoid valve SQL is arranged in the pilot pressure passage 15. The duty solenoid valve SQL completely drains the pilot pressure passage 15 when the control duty rate is 0%, and completely closes the pilot pressure passage 15 when the duty rate is 100%.

And the above lock-up control valve]0
When controlling the fastening force, the biasing force of the spring 10b and the duty solenoid valve SOL are located on the left side of the spool 10a in the figure.
The total pressure Pd including the pilot pressure adjusted in acts on the right side, and the opening pressure PR of the lock-up clutch 5 acts on the right side.
When Pd is PR, the spool 10a moves to the left in the figure to connect the opening pressure passage 12 to the drain boat 10c to lower the opening pressure, and connects the line pressure passage 13 to the pressure passage 11.
By communicating with P d > P and increasing the engagement pressure, the engagement force of the lock-up clutch 5 is increased.
When R, the spool 10a moves to the right in the figure (position shown) to cut off communication between the open pressure passage 12 and the drain boat 10c, and then connect the line pressure passage 13 to the open pressure passage 12. , the opening pressure is increased to reduce the engagement force of the lock-up clutch 5, and the above operations are repeated to control the engagement force of the lock-up clutch 5 to a value corresponding to the control duty rate of the duty solenoid valve SQL. I have to.

Therefore, as shown in FIG. 3, the duty solenoid valve SQL
When the control duty rate is 100%, the lock-up clutch 5 is completely opened, and as the duty rate decreases from 100%, the opening pressure decreases and the differential pressure ΔP between the engagement pressure and the opening pressure increases. Therefore, the engagement force of the lock-up clutch 5 increases, and the lock-up clutch 5 is completely engaged when the force is 0%.

In the hydraulic circuit shown in FIG. 2, 20 is a lock-up modifier valve, which includes a line pressure passage 13' branched from the line pressure passage 13, a pilot pressure passage 21, and the lock-up control valve 10. are connected to modifier pressure passages 22 for pressing the spools 1°a leftward in the figure, and a spring 20b is compressed at the lower end of the spool 20a, and the duty solenoid valve SQL is connected to the upper end of the spool 20a. The pilot pressure in the pilot pressure passage 15 whose pressure is regulated acts. When the duty rate of the duty solenoid valve SQL reaches around 096, the pilot pressure decreases greatly and the spool 20
By moving upward in the figure with the urging force of the spring 20b, the line pressure passage 13' is communicated with the modifier pressure passage 22, and the spool 10a of the lock-up control valve 10 is moved to the left end in the figure by line pressure. This ensures complete engagement of the lock-up clutch 5 by firmly pressing the lock-up clutch 5 against the lock-up clutch 5.

Further, in FIG. 2, 23 is a lock-up control solenoid, which is disposed in the pilot pressure passage 21, and when the lock-up clutch 5 is fully opened (the spool 10a of the lock-up control valve 10 is By draining the pilot pressure passage 21 at the right end in the figure), the pilot pressure that presses the spool 10a of the lock-up control valve 10 to the left in the figure is eliminated, ensuring complete opening of the lock-up clutch 5. It is something.

In addition, 24 is a converter relief valve that is interposed in the line pressure passage 13 and drains the line pressure when the line pressure exceeds a set pressure.

As shown in FIG. 4, the lock-up clutch 5 controls the input/output of the torque converter 2 within a slip region as a set control region surrounded by a solid line in an operating region determined by vehicle speed Vsp and throttle valve opening TVO. Axis 1a
, 2d, the lock-up clutch 5 is feedback-controlled to a predetermined engagement force so as to maintain the rotational speed difference between 2d and 2d at the set value, and when it moves from this area to outside the area surrounded by the broken line in the figure, it is in a fully open state. controlled by. In addition, when controlling the fastening force within the slip area surrounded by the solid line above, at the beginning of transition to this area, the initial control duty rate corresponding to the initial fastening force is set for the duty solenoid valve SQL in FIG. 2 above. After outputting B (see Fig. 3), as shown in Fig. 5, the control duty rate is gradually decreased from this initial value B, and the engagement force of the lock-up clutch 5 is controlled to be gradually strengthened. be done.

Therefore, with the above configuration, when the lock-up clutch 5 shifts from the open state to the slip region, the engaging force control is such that the engaging force of the lock-up clutch 5 is gradually increased from the initial engaging force corresponding to the initial control ff1B. It constitutes means 30.

Next, correction of the initial control amount B in the engagement force control of the lock-up clutch 5 will be explained based on the flowchart of FIG.

Start and lock-up clutch 5 in step S1.
The slip signal that is outputted at this time is OFF to determine whether or not it is the beginning of transition from the fully open state to the above-mentioned slip region.
→ It is determined whether the output is ON or not, and if the output is ON, the throttle valve opening TVO is read in step S2, and the timer starts counting time in step S3, and the elapsed time has passed since the transition to the slip region. Start measuring time.

After that, in order to understand the change in the engine speed NE due to the engagement force control of the lock-up clutch 5, in step S4, the current engine speed NEo41 and the previous engine speed N9 are compared, and NEn + + < N
When Ell is reached, the timer ends the time count in step S, and the measured time, that is, the time t from immediately after the shift to the slip region until the engine speed starts to decrease is grasped. Then, in steps S6 and S7, this measured time t is compared with the target value to. As shown in Fig. 7, this target value to differs depending on the throttle valve opening TVO when the shift to the slip region occurs. It is set for a long time in order to effectively reduce the If the measured time of t>to is longer, the initial duty control value B for the duty solenoid valve SQL is decreased to B-α in order to strengthen the initial fastening force in step S8.

On the other hand, if the measurement time of t<to is shorter, the initial duty control value B is increased to B+α so as to weaken the initial fastening force in step S9. finish.

Therefore, in the control flow shown in FIG.
,, S3 to S5 measure the time t until the input side rotational speed (that is, engine rotational speed) of the torque converter 2 stops increasing by the engagement force control of the lock-up clutch 5 after entering the slip region. indirectly, until the engagement force of the lock-up clutch 5 reaches the set engagement force value of the engagement force feedback control corresponding to the situation where the rotational speed difference between the input and output shafts of the torque converter 2 is the set value in this slip region. A time measuring means 31 is configured to measure the time of . Furthermore, in steps 56 to S of the same control flow, the duty initial value B of the duty electromagnetic valve SQL is corrected, so that the fastening force control means 30 performs the tightening operation according to the time t measured by the time measuring means 31. An initial control amount correction means 32 is configured to correct the initial control amount at the start of force increase control.

Therefore, in the above embodiment, as shown in FIG. 8, when the operating state shifts to the slip region shown in FIG. 4 and the slip signal is output ON, as shown by the broken line in FIG. When the elapsed time t until the subsequent engine speed starts to decrease is short, the lock-up clutch 5 is quickly engaged to the set engagement force, and the acceleration/deceleration G becomes large.
A large shock is likely to occur, but after that, as shown by the solid line, the initial control amount B of the duty solenoid valve SQL is learned to be larger than B+α, so the initial engagement force of the lock-up clutch 5 is adjusted to a smaller value, and the above elapsed time is t is the target value t
It becomes longer towards o. As a result, the acceleration/deceleration G becomes smaller, and the shock is effectively reduced.

On the other hand, when the elapsed time t until the engine speed starts to decrease is long, as shown by the broken line in FIG.
Although the lock-up clutch 5 is slowly engaged to the half-engaged state and the acceleration/deceleration G is small and the shock is small, the fuel efficiency is reduced, but in this case, as shown by the solid line, the initial control of the duty solenoid valve SQL is B-α is learned to be small, and as a result, the elapsed time t until the engine speed starts to decrease becomes shorter toward the target value to, so the engagement speed of the lock-up clutch 5 becomes faster and responsiveness becomes higher. Become.

In the above embodiment, after the initial engagement force of the lock-up clutch 5 is controlled to the set value by the initial control amount B of the duty solenoid valve SQL at the beginning of transition to the slip region, the rotation between the input and output shafts of the torque converter 2 is controlled. Of course, the fastening force may be subjected to fitback control or feedforward control so that the difference in numbers becomes the set value.

Furthermore, in the above embodiment, after transition to the slip control region,
Although the elapsed time t until the engine speed starts to decrease is measured, in the present invention, it is only necessary to measure the time until the engagement force of the lock-up clutch 5 reaches the set target value in the slip region, and the input/output shaft It may also be the time it takes for the rotational speed difference between to reach the set value.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 8 show embodiments of the present invention, FIG. 2 is a diagram showing the specific structure around the torque converter and the hydraulic circuit of the lock-up clutch, and FIG. 3 is a diagram showing the lock-up clutch with respect to the control duty rate. FIG. 4 is an explanatory diagram of the slip region, FIG. 5 is an explanatory diagram of feedback control of the clamping force, FIG. 6 is a flow chart diagram showing correction control of the initial value of the control duty rate, and FIG. Figure 7 is a diagram showing the target time characteristics with respect to the throttle valve opening.
The figure is an explanatory diagram of the operation. 1a... Engine output shaft, 2... Torque converter (fluid coupling), 2d... Converter output shaft, 5... Lock-up clutch (lock-up means), 101. ,
Lock-up control valve, SQL...duty solenoid valve, 30... fastening force control means, 31...
Time measurement means, 32... Initial control amount correction means.

Claims (3)

[Claims] (1) A fastening force control device for a fluid coupling, which includes a lockup means that directly connects the input and output shafts of the fluid coupling, and controls the fastening force of the lockup means to a set value in a predetermined setting control region. a fastening force control means for gradually increasing the fastening force of the lockup means from an initial fastening force corresponding to an initial control amount when the lockup means shifts from the open state to the setting control region; a time measuring means for measuring the time until the fastening force of the lock-up means controlled by the control means reaches a set value in a set control region; A fastening force control device for a fluid coupling, comprising: initial control amount correction means for correcting an initial control amount at the start of fastening force increase control. (2) The fastening force control means controls the duty of the solenoid valve for adjusting the fastening force in the setting control area, and feeds back the fastening force to the target value so that the rotational speed difference between the input and output shafts of the fluid coupling becomes the set value. The time measuring means measures the time until the rotational speed on the input shaft side of the fluid coupling stops increasing in the set control area, and the initial control amount correcting means measures the duty of the solenoid valve. The fastening force control device for a fluid coupling according to claim 1, wherein the device corrects the initial value. (3) The fastening force control device for a fluid coupling according to claim (2), wherein the time measuring means measures the time until the fastening force reaches the target value of the feedback control in the set control region.