JPH07764Y2 - Lockup controller for automatic transmission - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lockup control device for an automatic transmission mounted on a vehicle, and more particularly to a lockup control device adapted to perform a coast lockup with engine braking. .

2. Description of the Related Art Generally, an automatic transmission used in a vehicle such as an automobile is well known, and the structure thereof is, for example, the actual construction of Shokai 60-167.
There is something like that disclosed in No. 847. by the way,
In such automatic transmissions, engine power is input via a torque converter, but some engine output is lost in the torque converter depending on operating conditions, so some of the lockup clutches are lost. There is a converter that prevents the converter function from being performed in some operating areas. As described above, in an automatic transmission having a lock-up function, the lock-up, that is, the transmission is directly connected to the engine during a high-speed operation and the fuel consumption rate is significantly improved. That is, there is a lockup (coast rollup) during coasting when the accelerator is off, so that the engine brake works at high speed.

Problems to be Solved by the Invention However, when the engine brake is applied in this coast-lock-up state, a reverse torque is applied to the engine from the drive wheel side. Therefore, when the accelerator pedal is depressed again due to the necessity of acceleration during the coast-up, the positive torque is transmitted from the engine to the drive wheels. For this reason, there has been a problem that a large torque is generated in the lockup clutch due to a torque that is rapidly reversed when the accelerator is turned on.

Therefore, in view of the above problems, it is an object of the present invention to provide a lockup control device for an automatic transmission that reduces the reverse torque that acts on the lockup clutch when the accelerator is turned on from the coast lockup. .

Means for Solving the Problems In order to achieve the above object, the lockup control device for an automatic transmission according to the present invention includes a lockup clutch b which can be directly connected to an engine a as shown in FIG. Prepare,
In the lock-up control device of the automatic transmission c in which the coast locks up when the accelerator is off and the engine brake acts at this time, the accelerator-on detecting means d for detecting that the accelerator pedal is depressed during the coast lock-up. And the accelerator-on detection means d
When the accelerator pedal depression is detected, the lock-up operation means e is turned off to prohibit the complete lock-up state of the lock-up clutch b, and actually after the off signal is output to the lock-up operation means e. Has a timer g for which the time required for releasing the lockup clutch b is preset, and is set between the time when the off signal is output to the lockup actuating means e and the time set by the timer elapses. , Engine output control means f
And an engine control means h for outputting a fuel cut signal to reduce the engine output.

In the lock-up control device for an automatic transmission according to the present invention having the above-described structure, when the accelerator-on detecting means d detects the accelerator-on during the coast lock-up, the lock-up operating means e is turned off to lock the accelerator. By prohibiting the complete lock-up state of the up clutch b, the lock-up clutch b is in a half-clutch state or in a disengaged state, and the impact on the lock-up clutch b at the time of torque reversal is significantly reduced.

Further, the timer g of the engine control means h is preset with the time required from the output of the off signal to the lockup actuating means e to the actual release of the lockup clutch b. When the accelerator ON is detected by the accelerator ON detecting means d, the engine output is reduced for a predetermined time by the fuel cut signal provided from the engine control means h to the engine output control means f, so that the lockup clutch b is retained. The reverse torque itself that acts is also reduced, and the impact that acts on the lockup clutch b is alleviated until the lockup clutch b actually enters the half-clutch state or the disengaged state.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

That is, FIG. 2 shows a lockup control device 10 for an automatic transmission according to an embodiment of the present invention, in which 12 is an engine, 14 is an automatic transmission, and 16 is a torque converter provided between the engine 12 and the automatic transmission 14. Is. The torque converter 16 is provided with a lockup clutch 18, and when the lockup clutch 18 is connected (lockup), the output of the engine 12 is directly input to the transmission 14 without going through the converter function of the torque converter 16. On the other hand, when the lockup clutch 18 is disconnected, the engine output is input to the transmission 14 via the converter function.
In the half-clutch state of the lockup clutch 18, the engine output is input to the transmission 14 through both the sliding frictional force of the lockup clutch 18 and the converter function.
By the way, the operation of the lock-up clutch 18 is performed by the hydraulic oil supplied or drained from the lock-up control valve 20, and the switching control of the lock-up control valve 20 is performed. The lockup solenoid 22 as an operating means is turned on and off. For example, the lockup solenoid 22 is an automatic transmission control device.
When the drive signal from 24 is turned on, the lockup control valve 20 is switched to the drain side, and the converter pressure on the left side of the lockup piston 18a is discharged from the drain port 20a, so that the lockup clutch 18 is connected. On the other hand, when the lock-up solenoid 22 is turned off, the lock-up control valve 20 is switched to the hydraulic oil supply side so that the port 2 is provided on the left side of the lock-up piston 18a.
Since the converter pressure is supplied from 0b, the lockup clutch 18b is separated.

The automatic transmission control device 24 for driving the lock-up solenoid 22 receives an ON / OFF signal from an idle switch 26 as an accelerator ON detection means, receives a vehicle speed signal from a vehicle speed sensor 28, or a throttle sensor.
The throttle opening signal from 30 is input.

Further, the ON / OFF signals of the idle switch 26 are also input to the engine control unit 32, and the engine control unit 32 is input with the lockup signal from the automatic transmission control unit 24. When the lock-up signal is an ON signal indicating a lock-up state and the idle switch 26 is ON, that is, when the clutch pedal is released, the engine control device 32 causes the automatic transmission 14 to make the coast lock-up state. It comes to judge that it is in a state.

On the other hand, the engine control device 32 outputs a drive signal to the fuel injection device 32 as an engine output control means for injecting fuel into the engine 12, and controls the fuel injection amount, that is, the engine output in accordance with the output signal. It is going to be done.

The function of the lockup control device 10 of the present embodiment having the above configuration will be described with reference to the flow chart of FIG.

That is, the lock-up control in the lock-up control device 10 is performed by a preset lock-up schedule based on the vehicle speed signal obtained by the vehicle speed sensor 28 and the throttle opening signal obtained by the throttle sensor 30. By the way, in the rockup schedule, when the vehicle is running at a high speed and the engine speed is in a relatively large range, when the pedal is released from the accelerator pedal and the coasting state is maintained, the rockup clutch 18 is connected and the engine is directly connected. The engine brake is activated. As described above, the engine braking operation in the coast lockup is judged by the idle switch 26 and the lockup signal, and in the flow chart shown in FIG. 3, the judgment is made in step 100. When it is determined in step 100 that the idle switch 26 is off or the lockup signal is off and the coastlockup is not performed, step 1 is performed.
Proceed to 01 to perform normal fuel injection control. On the other hand, when the idle switch 26 is turned on and the lockup signal is turned on, if it is determined in step 100 that the coast lockup is detected, the process proceeds to step 102, and the idle switch 26 is turned off, that is, the accelerator pedal is depressed to turn the accelerator on. Determine whether or not If the accelerator is not turned on, the process returns to step 102 again, and the accelerator is judged to be turned on. On the other hand, when it is determined that the accelerator is turned on in step 102, the process proceeds to step 103,
The automatic transmission control device 24 outputs an off signal to the lockup solenoid 22 to release the lockup, and at the same time, the engine control device 32 outputs a fuel cut signal to the fuel injection device 34 to reduce the output of the engine 12.
The time when the fuel cut signal is output is preset by the timer 33 built in the engine control device 32, and the lockup clutch 18 is actually released after the off signal is output to the lockup solenoid 22. The fuel cut signal is output only for the time until it turns off.

As described above, in this embodiment, when the accelerator is turned on in the coast lockup state, the lockup can be released and the reverse rotation torque can be prevented from acting on the lockup clutch 18, and the lockup release signal is output. Since the engine output is reduced until the lockup is actually released, the lockup clutch 18 which is still in the connected state has no torque input from the engine 12 side or the input torque is extremely small. The shock due to the reverse rotation torque will be greatly reduced.

Incidentally, although the fuel injection device 32 is used as the engine output control means in the present embodiment, the invention is not limited to this, and the ignition advance device is used as the engine output control means to prevent the coast lockup. When the accelerator is turned on, the ignition timing may be retarded by a signal from the engine control device 32, and an exhaust gas recirculation control device, an intake air amount control device, a cylinder number control device, or the like may be used as the engine output control means. The engine output may be retarded.

Further, in this embodiment, the lockup clutch 18 is disclosed to be released when the accelerator is turned on during the coast lockup, but the lockup clutch 18 is not limited to this, but the lockup clutch 18 is in a half-clutch state, that is, as a half-lockup. Good.

Effect of the Invention As described above, in the lockup control device of the automatic transmission of the present invention, when the accelerator is turned on at the time of coast lockup, the complete lockup state of the lockup clutch is set through the lockup actuation means. Since the engine output is controlled by the engine output control means so as to be decreased for a predetermined period of time, the complete lockup is prohibited so that the reverse torque acting on the lockup clutch can be alleviated. Further, the engine output is reduced for a predetermined time, that is, only after the OFF signal is output to the lock-up actuating means until the lock-up clutch is actually released, so that the lock-up clutch prohibits substantially complete lock-up. Since the engine output can be reduced until the above, the reverse torque acting on the lockup clutch which is still in the lockup state due to the output of the complete lockup inhibition signal can be remarkably reduced. Therefore, the impact due to the reverse torque when the accelerator is turned on from the coast lockup can be greatly reduced,
It has an excellent effect that the ride quality of the vehicle can be remarkably improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the concept of a lockup control device for an automatic transmission according to the present invention, FIG. 2 is a system diagram showing an embodiment of the present invention, and FIG. 3 is a program for the lockup control device of the present invention. It is a flow chart which shows one example of processing for performing. 10 …… Lockup controller, 12 …… Engine, 14 ……
Automatic transmission, 16 ... Torque converter, 18 ... Lockup clutch, 22 ... Lockup solenoid (lockup actuating means), 26 ... Idle switch (accelerator ON detection means), 32 ... Engine control device (engine control Means), 33 ... timer, 34 ... fuel injection device (engine output control means).

Claims (1)

[Scope of utility model registration request] 1. A lock-up clutch that can be directly connected to an engine, and is coast-locked up when the accelerator is off,
In the lock-up control device for the automatic transmission in which the engine brake is activated at this time, an accelerator-on detecting means for detecting that the accelerator pedal is depressed during the coast lock-up, and an accelerator pedal for detecting the accelerator pedal by the accelerator-on detecting means. When the depression is detected, the lock-up clutch is disengaged to prohibit the complete lock-up state of the lock-up clutch, and the lock-up clutch is actually released after the OFF signal is output to the lock-up clutch. A timer having a preset time required for the operation is provided, and a fuel cut signal is provided to the engine output control means from the time when the off signal is output to the lock-up operation means to the time when the timer setting time is up. Engine control means for outputting to reduce the engine output, A lock-up control device for an automatic transmission, comprising: