JPH0718484B2 - Lockup control device for automatic transmission - Google Patents

Description

The present invention relates to a lockup control device for an automatic transmission.

An automatic transmission provided with a lockup clutch that directly connects the input shaft and the output shaft of the torque converter, and engages the lockup clutch in an appropriate vehicle traveling state to obtain power transmission efficiency equivalent to that of mechanical drive. Is conventionally known. The above lockup clutch is generally disclosed in
Using an electric control device as disclosed in Japanese Patent Publication No. 55-109854, control is performed so as to set a lockup state in a vehicle traveling area as shown in FIG. 1, for example.

However, if the lockup state is set only in accordance with the vehicle running state as described above, in most areas other than the area near the lockup release line (for example, point A in the example of FIG. 1), sudden acceleration occurs during traveling in the lockup state. Even if the accelerator is suddenly stepped on in order to achieve this, the lockup state is not released at all, so that the torque increasing action of the torque converter cannot be utilized and sufficient acceleration cannot be achieved.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lockup control device for an automatic transmission that solves the above inconvenience.

The lockup control device for an automatic transmission according to the present invention is, in the lockup control device provided with a controller for engaging and releasing the lockup clutch in accordance with the vehicle traveling state as described above, a change speed in the increasing direction of the engine load. An engine load change speed detection unit for detecting a state quantity other than the engine load change rate, and a state quantity detecting means for detecting a predetermined state quantity in which the vehicle acceleration becomes more remarkable as the value increases. And a signal for forcibly releasing the lockup clutch only when the changing speed in the increasing direction of the engine load is a predetermined value or more and the state quantity is a predetermined value or more in the traveling region in which the lockup clutch is engaged. A lockup releasing section for outputting is provided.

By providing the lockup releasing portion as described above, when the vehicle is suddenly accelerated, the lockup state is immediately released regardless of the traveling state of the vehicle, and the torque converter is effectively used to perform sufficient acceleration.

Further, examples of the above-mentioned state quantity include the elapsed time from the accelerator depression, the accelerator opening change amount, the accelerator stroke change amount, and the like. The lock-up release unit releases the lock-up clutch when not only the engine load change speed but also such a state amount becomes a predetermined value or more, so the degree is low even if an acceleration operation is performed. If, the lockup state is not released. Therefore, the lockup state is not frequently released and fuel consumption is not deteriorated, although it is not so necessary.

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

FIG. 2 shows a lockup control device for an automatic transmission according to an embodiment of the present invention. The torque converter A of the automatic transmission includes a pump impeller 1, a turbine runner 2,
It consists of the stator 3. The pump impeller 1 is driven by a crankshaft 6 via a converter cover 4 and a drive plate 5. On the other hand, the turbine runner 2 is spline-engaged with the output shaft 8 via the hub 7, and the stator 3
Is connected to the sleeve 10 via the one-way clutch 9. The hub 7 has a lockup clutch piston.
11 is slidably fitted to the hub 7. An annular clutch facing 11a is provided on a surface of the lock-up clutch piston 11 facing the end wall of the converter cover 4, and when the clutch facing 11a comes into contact with the end wall of the converter cover 4, the lock-up clutch clutch 11a is provided. A lockup chamber 12 and a torque converter chamber 13 are defined on both sides of the piston 11. The lockup clutch piston 11 is drivingly connected to the turbine runner 2 via a torsion damper 14. The output shaft 8 is provided with a lockup passage 8a communicating with the lockup clutch chamber 12, and the passage 8a is connected via an oil passage 15 to a lockup control valve 16 described later.

The lockup control valve 16 includes a spool 16b biased rightward in the figure by a spring 16a and four ports 16c, 16
d, 16e, 16f, and the port 16c is the oil passage 15 described above.
The port 16e is connected to the torque converter hydraulic oil supply passage 17 via an oil passage (not shown), the port 16f is connected to the oil passage 18, and the port 16d is a drain port. The oil passage 18 has a branch passage 18b communicating with the drain port 18a, and the branch passage 18b is opened and closed by the plunger 19a of the solenoid 19. That is, the plunger 19a is set to an upper position on the right side and a lower position on the left side of the center line in the figure by the excitation and demagnetization of the solenoid 19, and when set to the upper position, the branch passage 18b is closed, and when set to the lower position, the plunger 19a branches. Open the aisle 18b. Hydraulic pressure is applied to the oil passage 18 from a hydraulic pressure source (not shown).

When the solenoid 19 is energized and excited, the plunger 19a is driven to the upper position and the branch passage 18b is closed. Therefore, the spool 16b of the lock-up control valve 16 is moved to the left by the hydraulic pressure in the oil passage 18 (the position shown in the lower half of the center line in the figure).
To connect the drain port 16c to the drain port 16d. As a result, the lockup chamber 12 has a lockup passage 8a and an oil passage.
It is opened to the above drain port 16d through 15. Therefore, the lockup clutch piston 11 is installed in the torque converter chamber.
The internal pressure of the torque converter in 13 causes the torque converter internal pressure to move to the left in the drawing to press the converter cover 4 as shown in the drawing, and the lockup state in which the crankshaft 6 and the output shaft 8 are directly connected is set.

On the contrary, when the solenoid 19 is demagnetized, the plunger 19a
Moves to the lower position and the branch passage 18b is opened. Then, the oil pressure of the oil passage 18 is released to the drain port 18a, and the spool 16b of the lockup control valve 16 moves to the right position (the position shown in the upper half of the center line in the figure) by the urging force of the spring 16a, and the port 16c. To port 16e. Thereby,
The torque converter internal pressure acting on the port 16e through the oil passage communicating with the hydraulic oil supply passage 17 causes the lockup chamber
In addition to 12, the lockup chamber 12 is a torque converter chamber.
It is set to the same pressure as 13. As a result, the pressure of the lockup clutch piston 11 on the converter cover 4 is released,
The direct connection state between the crankshaft 6 and the output shaft 8 is released.

Hereinafter, a control device for engaging and releasing the lockup clutch piston 11 with respect to the converter cover 4 by turning on and off the solenoid 19 will be described. A vehicle speed sensor 20 and an accelerator opening sensor 21 are provided to detect the vehicle running state, and the vehicle speed signal S ₁ and the accelerator opening signal S ₂ of these sensors 20, 21 are input to a lockup determination circuit 22. The vehicle speed sensor 20 is composed of a combination of a magnet and a pick-up coil fixed to the output shaft of the automatic transmission,
Alternatively, the engine speed or the turbine speed of the torque converter may be detected. The accelerator opening sensor 21 is composed of a circuit or the like having a variable resistance operated by an accelerator pedal.

The lock-up determination circuit 22 has been generally used for lock-up control from the past. For example, based on the setting as shown in FIG. 1 described above, when the vehicle traveling state is in the lock-up region, A level signal "1" is output, and a low level signal "0" is output when the vehicle traveling state is in the non-lockup area. The output of the lockup determination circuit 22 is input to the AND gate 23. The solenoid 19 turns on when a signal "1" is input from the AND gate 23, and when a signal "0" is input.
It turns off.

The accelerator opening signal S ₂ of the accelerator opening sensor 21 is input to the lockup determination circuit 22 as described above, and also input to the differentiating circuit 25, and the differential output of the differentiating circuit 25.
S ₂ ′ is input to the negative terminal of the comparator 26. Comparator 26
Compares the setting changeable reference signal V _r with the differential output S ₂ ′, and when the differential output S ₂ ′ is below the reference signal V _r , that is, when the accelerator opening speed is below a predetermined value, the signal “1” is output.
On the contrary, when the accelerator opening speed exceeds a specified value, differential output
When S ₂ ′ becomes equal to or higher than the reference signal V _r , the signal “0” is output.
The output of the comparator 26 is input to the OR gate 27.

The differential output S ₂ ′ is input to the comparator 26 as described above and also input to the plus terminal of the comparator 28. Comparator 28
When a positive differential output S ₂ 'is entered, i.e. outputs a signal "1" when the accelerator is opened, and inputs the one-to bracts multivibrator 29. When the signal "1" is input, the one-shot multivibrator 29 outputs a high level signal "1" for a predetermined time t, and returns the output to "0" after the predetermined time t has elapsed.

As described above, the comparator 26 outputs the signal "1" unless the accelerator is opened (that is, is rapidly accelerated) at a large opening speed equal to or higher than the predetermined value. Therefore, the comparator 26 of the one-shot multivibrator 29 OR gate 27 regardless of output
The output becomes "1". Therefore, if the vehicle is traveling in the lockup area at this time and the output of the lockup determination circuit 22 is "1", the output of the AND gate 23 becomes "1" and the solenoid 19 is turned on. Then, the lockup clutch piston 11 is engaged with the converter cover 4.

Of course, if the vehicle is traveling in the non-lockup area, the output of the lockup determination circuit 22 becomes "0", so the output of the AND gate 23 becomes "0" regardless of the output of the OR gate 27.
Then, the lockup clutch piston 11 is released from the converter cover 4.

The output of the comparator 26 becomes "0" when a rapid acceleration is performed so that the accelerator opening speed becomes a predetermined value or more. But the comparator
Due to the action of 28 and the one-shot multi-vibrator 29, the signal "1" is input from the one-shot multi-vibrator 29 to the OR gate 27 for a predetermined time t after the accelerator is depressed, so the predetermined time after the accelerator is depressed. t
During this period, the output of the OR gate 27 is always "1". Even after the output of the one-shot multivibrator 29 is switched to "0" after the elapse of the predetermined time t, if the output of the comparator 26 is "0", the output of the OR gate 27 is "0". From AND
Output "0" of the gate 23, if the vehicle output of the solenoid drive signal S ₃ be run is stopped by Rotsukuatsupu region, Russia look up class Tutsi is forcibly released. With the release of the lockup clutch,
Power is transmitted through the torque converter A, and the torque increasing action of the torque converter A is utilized to perform sufficient acceleration. Although the accelerator pedal is fast,
When the amount of depression is small, even if the accelerator is opened at an opening speed higher than a predetermined value within an extremely short time below the predetermined time t, the output of the one-shot multivibrator 29 is "1". Because there is an OR gate
27 output becomes "1", and unnecessary lock-up release is not performed when traveling in the lock-up area.

As is clear from the above description, in the present embodiment, the accelerator opening sensor 21 and the differentiating circuit 25 constitute an engine load change speed detecting section, and the comparator 28 and the one-shot multivibrator 29 have a predetermined state quantity. That is, the state quantity detecting means for detecting the time after the accelerator is depressed is configured.

The setting device of the above embodiment controls the lockup clutch drive signal to release the clutch at the time of sudden acceleration, but it is also possible to forcibly release the lockup clutch by other methods. is there. FIG. 3 shows a control device for canceling the lockup during traveling in the lockup region by correcting the signal indicating the vehicle traveling state. The lockup determination circuit 40 includes an accelerator opening signal S _{10 from} the accelerator opening sensor 41 and a vehicle speed sensor 42.
A vehicle speed signal S ₁₁ is input, but whether to the Rotsukuatsupu in accordance with the vehicle traveling state is determined vehicle speed signal S ₁₁ is input to Rotsukuatsupu determination circuit 40 through the subtractor circuit 43 to be described later. The accelerator opening speed detection circuit 44 is composed of the above-mentioned differentiating circuit 25 and the like, and inputs the accelerator opening speed signal S ₁₃ to the function generating circuit 45. The function generation circuit 45 inputs the subtraction signal S ₁₄ according to the accelerator opening speed signal S ₁₀ to the subtraction circuit 43 through the analog gate 46. In the subtraction circuit 43, the vehicle speed signal S ₁₁ is corrected to a lower speed side by the subtraction signal S _{14 as} the accelerator opening speed is higher, and is input to the lockup determination circuit 40 as a corrected vehicle speed signal S ₁₁ ′. That is, referring to FIG. 1, since the vehicle speed is corrected to the low speed side (left side in the drawing), even if the vehicle is actually traveling in the rockup region, the rockup determination circuit
40 determines that it is traveling in the non-lockup area and forcibly releases the lockup. The analog gate 46 is a comparison circuit 47 that determines that the accelerator opening change is greater than or equal to a predetermined amount.
Output S ₁₅ and the output of the accelerator stroke detection circuit 48 that determines that the accelerator stroke change is more than a predetermined amount
The output S ₁₇ of the AND gate 49 to which S ₁₆ is input is opened and closed, and a slight accelerator change is ignored, and the vehicle speed signal S ₁₁ is corrected only when the actual acceleration is performed.

In both of the above-mentioned two embodiments, the circuit for releasing the lockup at the time of sudden acceleration is constituted by a hard circuit, but it is also possible to perform the signal processing by using a microcomputer to release the lockup. It is possible.

As described in detail above, the lockup control device for an automatic transmission according to the present invention automatically releases the lockup when a rapid acceleration is performed even during traveling in the lockup region, and effectively increases the torque of the torque converter. Will be used to fully enhance the acceleration performance of the vehicle.

[Brief description of drawings]

FIG. 1 is a graph showing an example of a lockup setting region of an automatic transmission with a torque converter, FIG. 2 is a system diagram showing one embodiment of the present invention, and FIG. 3 is a block showing another embodiment of the present invention. It is a figure. A ... Torque converter, 4 ... Converter cover 6 ... Crank shaft, 8 ... Output shaft 16 ... Lock-up control valve, 19 ... Solenoid 20, 42 ... Vehicle speed sensor 21, 41 ... Accelerator position sensor 22 , 40 …… Lockup judgment circuit 23 …… AND gate, 25 …… Differentiation circuit 26 …… Comparison circuit, 43 …… Subtraction circuit 44 …… Accelerator opening speed detection circuit 45 …… Function generation circuit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Keiji Boda 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Toyo Kogyo Co., Ltd. (56) References JP-A-57-69165 (JP, A) JP-A-SHO 57-76360 (JP, A) JP-A-55-129648 (JP, A) JP-A-57-184754 (JP, A) Practical application Sho-57-19254 (JP, U)

Claims (1)

[Claims] 1. A torque converter, a lockup clutch that directly connects an input shaft and an output shaft of the torque converter, a controller that controls engagement and disengagement of the lockup clutch according to a vehicle running state, and an engine load. An engine load change speed detection unit that detects a change speed in an increasing direction, and a predetermined state quantity other than the engine load change speed, in which the vehicle acceleration becomes more significant as the value increases. In the traveling area in which the state quantity detecting means and the lockup clutch are engaged, the lockup clutch is forced only when the changing speed in the increasing direction of the engine load is a predetermined value or more and the state quantity is a predetermined value or more. A lockup control unit for an automatic transmission, comprising: a lockup release unit that outputs a release signal to the lockup control unit.