JP3354197B2 - Fluid coupling fastening force control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling a lock-up clutch engagement force of a fluid coupling (torque converter).

[0002]

2. Description of the Related Art Generally, in the control of a torque converter, in order to prevent a shock from occurring at the time of shifting, a slip-up in which the lock-up clutch is half-engaged before a lock-up state in which the lock-up clutch is completely engaged. Control is performed. Further, in a region below the no-load line where a load is applied to the engine from the wheels, the torque converter is normally in a converter state, and such slip control is not performed.

[0003]

Here, even in an area below the no-load line in which the converter is in a converter state, in an area where the throttle opening is small, the lock-up clutch is half-engaged from the viewpoint of improving fuel efficiency. There is a control device that performs deceleration slip control. Since the deceleration slip control aims at improving the fuel efficiency of the vehicle, it is preferable that the engagement force of the lock-up clutch in the deceleration slip control be large. In such a control device, when the throttle opening decreases from a value exceeding the no-load line to become equal to or lower than the no-load line and further enters the deceleration slip region, the engagement state of the lock-up clutch changes. In such a case, a deceleration shock may occur, giving the driver an uncomfortable feeling. Therefore, there is a demand for an engagement force control device that can increase the engagement force of the lock-up clutch in deceleration slip control without causing a deceleration shock.

[0004] The present invention has been made in response to such a demand, and the present invention has been made in view of the above-mentioned circumstances. It is an object to provide a control device.

[0005]

According to the present invention, slip control for variably controlling the lock-up clutch engagement force is performed in a first region where the throttle opening is equal to or less than a predetermined value, and a load is applied from the wheels to the engine. In such a region below the no-load line, the torque converter is in the converter state, and in the deceleration slip region where the throttle opening is small, the engagement control device for the fluid coupling further variably controls the engagement force of the lock-up clutch. The initial value of the lock-up clutch engagement force when the throttle opening is reduced from the portion of the first region where the throttle opening is larger than the no-load line is changed from the throttle opening larger than the predetermined value to the throttle opening on the high vehicle speed side. Initial stage of the lock-up clutch engagement force when the degree is reduced Fastening force control apparatus for a fluid coupling and sets greater is provided.

In the first region where the throttle opening is larger than the no-load line, since the torque converter is slip-controlled, the difference in rotation between the input side and the output side of the torque converter is not large. Further, in this portion, since the no-load line is located on the low throttle opening side as compared with the high vehicle speed side, the region where the converter state is between the no-load line and the deceleration slip region is narrow. Accordingly, while the throttle opening is decreasing, the time of the converter state between the slip control and the deceleration slip control becomes extremely short. Therefore, even when the initial value of the engagement force of the lock-up clutch at the time of entering the deceleration slip control is set to be large, fuel efficiency is improved by increasing the engagement force of the lock-up clutch without causing a deceleration shock. .
On the other hand, when the throttle opening is larger than the predetermined value, the torque difference between the input side and the output side is large because the torque converter is in the converter state. Further, on the side where the vehicle speed is high, since the no-load line is located on the high throttle opening side, the width of the region in the converter state between the no-load line and the deceleration slip region is wide. Therefore, while the throttle opening is decreasing, there is a relatively long converter state before the deceleration slip control is started. In the converter state, since the rotation difference between the input side and the output side of the torque converter is large, the initial value of the engagement force of the lock-up clutch at the time of entering the deceleration slip control is set small so as not to cause a deceleration shock. I have.

[0007]

FIG. 1 is a schematic diagram showing the overall configuration of an embodiment of the present invention. The output of the engine 1 is transmitted to drive wheels (not shown) via the automatic transmission 2. The automatic transmission 2
It comprises a torque converter 3 and a planetary gear type multi-stage transmission mechanism 4. The torque converter 3 includes a lock-up clutch (which will be described later). By controlling the duty solenoid 5 for lock-up, the lock-up clutch is turned on (engaged), turned off (disengaged), or half-clutched. State. The relationship between the duty ratio of the duty solenoid 5 and the engagement force of the lock-up clutch is set, for example, as shown in FIG.

The automatic transmission mechanism 4 includes, for example,
By changing the combination of excitation and demagnetization of the plurality of shift solenoids 6 as known, a desired shift stage can be obtained. In addition, each solenoid 5,
Numeral 6 is for switching the operation mode of the hydraulic actuator for lock-up or shifting. Signals from the sensors 11 to 16 are input to the control unit 10 which is controlled using a microcomputer. The throttle opening sensor 11 detects the throttle opening of the engine 1, the vehicle speed sensor 12 detects the vehicle speed, and the engine speed sensor 1
Reference numeral 3 denotes an engine speed, that is, a speed of a pump as an input member of the torque converter 3, a gear position sensor 14 detects a current gear position of the automatic transmission 2, that is, a gear position, and a turbine speed sensor 15 detects a turbine speed. The rotation speed, that is, the rotation speed of the output member of the torque converter 3 is detected, and the oil temperature sensor 16 detects the temperature of the hydraulic oil for the lock-up clutch. The output from the control unit 10 to each of the solenoids 5 and 6 is performed.

The control unit 10 basically includes a CP
In addition to having a U, ROM, RAM, and CLOCK (soft timer), it has an A / D or D / A converter and an input / output interface. These are known configurations when a microcomputer is used. The shift characteristics (map) and the like used in the following description are the same as those of the control unit 10.
It is stored in the OM.

FIG. 2 shows a structure of a torque converter with a lock-up clutch and a hydraulic circuit for controlling the same. The torque converter 3 is fixed to one side of a case 33 connected to the engine output shaft 32, and has a pump (input member) 34 integrally rotating with the engine output shaft 32, and a case 33 facing the pump 34. A turbine 35 (output member) rotatably provided on the other side of the inside and rotatably driven via hydraulic oil by the rotation of the pump 34, and is provided between the pump 34 and the turbine 35. And a lock-up clutch 37 interposed between the turbine 35 and the case 33 when the speed ratio of the turbine rotation speed to the engine speed is equal to or less than a predetermined value. The rotation of the turbine 35 is output by the turbine shaft 38 and input to the transmission gear mechanism 4. When the lock-up clutch 37 is connected to the turbine shaft 38 and fastened to the case 33, The engine output shaft 32 and the turbine shaft 38 are directly connected via the case 33.

The oil discharged from the oil pump 50 is guided to the main line 39 of the torque converter 3 via a pressure regulating valve 51 controlled by the solenoid 21.
Lock-up valve 40 and converter in-line 41
And is introduced as hydraulic oil via the The lock-up clutch 37 is constantly urged in the engagement direction by the pressure of the hydraulic oil, and a lock-up release line 4 guided from the lock-up valve 40 is provided in a space 42 between the lock-up clutch 37 and the case 33.
The lock-up clutch 37 is released when hydraulic pressure (release pressure) is introduced into the space 42 from the line 43. Further, a converter outline 46 for sending hydraulic oil to an oil cooler 45 via a pressure holding valve 44 is connected to the torque converter 3.

The lock-up valve 40 includes a spool 40
a and a spring 40b for urging the same to the right as viewed in the drawing, and a pressure regulating port 40d and a drain port 40e to which the main line 39 is connected on both sides of the port 40c to which the lockup release line 43 is connected. Are provided. Also, on the drawing of the lock-up valve 40,
A control line 47 for applying a pilot pressure to the spool 40a is connected to an end on the right side. A drain line 48 branched from the control line 47 is connected to a solenoid (duty solenoid valve) 5 as slip amount adjusting means. Is installed. This solenoid 5
Changes the drain line 48 continuously and variably from fully open to fully closed according to an input signal (duty ratio). This pilot pressure is applied to the spool 40a of the lock-up valve 40 in a direction opposite to the biasing force of the spring 40b, and the spool 40a is provided with a lock-up release line 4 in the same direction as the biasing force of the spring 40b.
3, the spool 40a moves due to the relationship between the hydraulic pressure and the urging force, and the lock-up release line 43 is moved to the main line 39.
(Pressure adjusting port 40d) or the drain port 40e. Note that when the duty ratio is the maximum value, the drain amount from the control line 47 is maximized, and the pilot pressure or the release pressure is minimized, whereby the lock-up clutch 37 is completely engaged, and the duty ratio is reduced to the minimum value. In this case, the drain amount is minimized and the pilot pressure or the release pressure is maximized.
Is completely released. When the duty ratio is an intermediate value between the maximum value and the minimum value, the lock-up clutch 37 is in a half-clutch state.

FIG. 3 is a diagram showing a shift characteristic and a lock-up characteristic in which the horizontal axis indicates the vehicle speed and the vertical axis indicates the throttle opening, and FIG. 4 is an enlarged view of a part of the control region of FIG. FIG. The control unit 10 performs shift control and lockup control based on shift characteristics and lockup characteristics as shown in FIG. In FIG. 3, a region B is a lock-up ON region where the lock-up clutch 37 is completely engaged, and a region C on a higher load side than the region B is a lock-up OFF region where the lock-up clutch 37 is completely released. is there. A region (first region) A set on a lower vehicle speed side than the region B causes the lock-up clutch 37 to slip and the lock-up clutch engagement force with the difference between the rotational speeds of the input side and the output side of the torque converter 3 as the target value. Is a slip region in which feedback control is performed. These areas A, B, and C are separately set for acceleration or deceleration. Note that the shift control itself is performed in the same manner as in the related art. In addition, the regions where the throttle opening degrees of these regions A and B are minute are deceleration slip regions. In FIGS. 3 and 4, this deceleration slip region is deliberately described on the minus side for clarity, but actually, the lowermost plus side region of the regions A and B in FIGS. It is located in.

In the lock-up control, slip control is performed when the lock-up clutch 37 shifts between the engaged state and the released state. That is,
The engagement force of the lock-up clutch 37 gradually changes in order to suppress torque fluctuations in the output section of the automatic transmission 2. As shown in FIG. 4, when the throttle opening decreases from the point X1 in the slip control region to the point X2 in the deceleration slip over the no-load line 50, the lock-up clutch 37 enters a semi-engaged state. In this case, the hydraulic pressure (or oil amount) serving as the release pressure supplied to the lock-up clutch 37 is set to R1 by the control unit 10. On the other hand, in a region on the higher vehicle speed side than the point X1 and on a higher load side than the slip control region, the throttle opening is set to the point Y1.
The hydraulic pressure (or oil amount) serving as the release pressure to be supplied to the lock-up clutch 37 when the pressure drops to the point Y2 within the deceleration slip through the no-load line 50 is set to R2 by the control unit 10. Here, R1> R2
It is.

That is, the hydraulic pressure supplied when the throttle opening shifts from the point X1 in the slip control region to the point X2 in the deceleration slip, that is, when returning from a state where the throttle opening is a small opening. Hydraulic pressure R supplied to
1 is larger than the hydraulic pressure supplied when the throttle opening decreases from the point Y1 to the point Y2, that is, the hydraulic pressure R2 supplied when returning from a state where the throttle opening is large, and therefore, lockup The clutch 37 is engaged with a larger engagement force.

FIG. 5 is an example of a flowchart for operating the fluid coupling fastening force control device according to the present invention.
First, the control unit 10 controls the throttle opening sensor 11
From the vehicle speed sensor 12 to the vehicle speed V
From the engine speed sensor 13 to the engine speed Ne
From the turbine speed sensor 15 to the turbine speed Nt
Are read (step 100).

Next, the control unit 10 determines whether or not the read throttle opening θ is smaller than 1/16 which is the set opening in the deceleration slip control region (step 110). If the result of this determination is YES, the set time T is replaced by (T + 1) (step 1).
20).

On the other hand, if the determination is NO, the set time T is set to 0 (step 130). Then
The control unit 10 determines whether or not the vehicle is in the deceleration slip operation region based on the read throttle opening θ and vehicle speed V based on the diagram shown in FIG. 3 (step 14).
0).

If the determination result is NO, that is, if the vehicle is not in the deceleration slip region, the process returns to step 100, and the above steps are repeated. On the other hand, when the determination result is YE
If it is S, the control unit 10 further determines whether the set time T is longer than a predetermined time α (for example, α = 2 seconds) (Step 150).

If the result of this determination is YES, the duty value D1 at the start of the deceleration slip control is changed to D1.
= A is set (step 160). On the other hand, if the determination result is NO, the duty value D2 at the start of the deceleration slip control is set to D2 = B (step 17).
0). Here, each of the duty values A and B is set so that B> A. Therefore, as shown in FIG. 6, the lock-up fastening force for the duty value D1 = A is larger than the lock-up fastening force for the duty value D2 = B. That is, the lock-up fastening force for the duty value D1 = A is set in the lock-up fastening direction,
The lockup fastening force for the duty value D2 = B is set in the lockup release direction.

[0021]

As described above, according to the fluid coupling engagement force control device of the present invention, it is possible to achieve both an increase in the engagement force of the lock-up clutch in the deceleration slip control and a reduction in the deceleration shock. It is possible to provide an apparatus for controlling a fastening force of a fluid coupling.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing an entire embodiment of a fastening force control device for a fluid coupling according to the present invention.

FIG. 2 is a schematic diagram showing a torque converter and a hydraulic circuit thereof.

FIG. 3 is a characteristic diagram showing a shift characteristic and a lock-up characteristic.

FIG. 4 is an enlarged view of a part of FIG. 3;

FIG. 5 is an example of a flowchart of a fastening force control device for a fluid coupling according to the present invention.

FIG. 6 is a diagram showing a relationship between a lock-up fastening force and a duty ratio.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 61/14

Claims (1)

(57) [Claims] A first valve having a throttle opening smaller than a predetermined value;
Slip control for variably controlling the lock-up clutch engagement force is performed in the region, and the torque converter is set to the converter state in a region below the no-load line where a load is applied from the wheels to the engine, and the deceleration slip in which the throttle opening is minute is small. In a region, the lock-up clutch engagement force variably controls the fluid coupling engagement force control device, wherein the lock when the throttle opening is reduced from a portion of the first region where the throttle opening is larger than the no-load line. A fluid characterized in that an initial value of the up-clutch engagement force is set to be larger than an initial value of the lock-up clutch engagement force when the throttle opening is reduced from a throttle opening larger than the predetermined value on a high vehicle speed side. Joint fastening force control device.