JPS6034567A - Lockup control device of automatic transmission for automobile - Google Patents

Abstract

PURPOSE:To improve the fuel economy by providing an operating condition detection means and a differential rotational speed detection means so that even when there is a slight differential rotational speed between a drive shaft and a driven shaft, they are brought into a lockup condition smoothly and quickly. CONSTITUTION:A lockup solenoid control device is provided with an operating condition detection means to detect a predetermined operating condition in which a lockup is possible and a differential rotational speed detection means to detect a differential rotational speed between the engine speed and a turbine speed. When under a predetermined operating condition and the differential rotational speed is below the first set value, the lockup solenoid is continuously turned ON, and when under a predetermined operating condition and the differential rotational speed is above the first set value but below the second set value, the lockup solenoid is intermittently turned ON. Since the lockup condition is attained smoothly and quickly from a condition where there exists a differential rotational speed in this manner, the lockup condition can be lengthened to further improve the fuel economy.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a lock control device for an automatic transmission for an automobile.

BACKGROUND TECHNOLOGY As conventional automatic transmissions for automobiles, under predetermined operating conditions (for example, when driving at high speeds above a certain vehicle speed), the number of revolutions of the drive shaft on the engine side and the number of revolutions of the driven shaft are almost the same. In some cases, there is a lock-up mechanism that connects the drive shaft and the driven shaft without going through a torque converter, eliminating energy loss caused by going through a torque converter, and thereby improving fuel efficiency.

An example of an automatic transmission equipped with such a lock-up mechanism will be explained with reference to FIG.

The torque converter consists of a case 2 that is fixed to and rotates on a drive shaft 1 on the engine side, a pump impeller 3 attached to the case 2, a turbine runner 5 attached to a driven shaft 4, and a one-way flange 6. supported stator 7
With the rotation of the pump impeller 3, the oil flowing from the pump impeller 3 into the turbine runner 5 rotates the turbine runner 5, and the oil flowing out of the turbine runner 5 is directed by the stator 7 in a direction that does not interfere with the rotation of the pump impeller 3. and smoothly enters the pump impeller 3, thereby transmitting power.

The lock-up mechanism is provided with a lock-up plate 9 having a tarante phasing 8 facing the inner wall of the case 2. The lockup plate 9 is integral with a torsion damper 10, and the torsion damper 10 is fixed to the clutch hub II.

The clutch hub 11 is spline fitted to the driven shaft 4, so that the lock amplifier plate 9 is movable in the axial direction and moves in response to the pressures P, P2 in the chambers 12, 13 on both sides.

Here, the pressure P+ in the chamber 12 is the Humbata pressure, which is controlled to be approximately constant.

An oil passage 14 communicating with the chamber 13 is connected to a lock-up control valve 15.
It is connected to the converter pressure introduction path 16 and the drain path 17 through the lock-up control valve 15, and when the lock-up control valve 15 is moved to the right in the figure, the oil path 14 and the converter pressure introduction path 16 are connected to each other. As a result, P2=P, and the lock amplifier plate 9 moves to the right in the figure, separates from the inner wall of the case 2, and enters the serial number state (non-lockup state).

Further, when the lock-up control valve 15 is moved to the left in the figure, the oil passage 14 and the drain passage 17 are in communication with each other.
As a result, (2)<P+ (P2=O), the lockup plate 9 moves to the left in the figure and comes into pressure contact with the inner wall of the case 2, resulting in a lock amplifier state. In this state, the rotation of the case 2 by the drive shaft 1 is prevented by the lock-up plate 9.
is transmitted to the driven shaft 4 via.

A pressure operating chamber 18 is provided on the end face of the lock amplifier control valve 15.
A line pressure introduction path 19 is connected to this pressure working chamber 18 . A drain path 2o is provided in the middle of the line pressure introduction path 19, and this drain path 2o is connected to a lock-up solenoid 2o.
1 is provided. The lock-up solenoid 21 is turned on and off by a lock amplifier control unit 22.

Therefore, by turning off the lock-up solenoid 21 to open the drain passage 2o and turning off the line pressure acting on the lock-up control valve I5 from the pressure operating chamber 18, the lock-up control valve 15 is moved to the right in the figure. , the lock-up solenoid 21 is turned on and the drain path 2o is turned on.
By shutting off the lock-up control valve 15 and turning on the line pressure acting on the lock-amp control valve 15 from the pressure-operated chamber 18, the lock-up control valve 15 can be moved to the left in the figure to enter the lock-amp state.

However, in such conventional automatic transmissions with a lock-up mechanism, since the control was simply on/off, there was a problem of shock when switching to the lock-up state, and the difference in rotational speed between the drive shaft and driven shaft caused a problem. The problem is that you can't lock it up when it's small enough.

<Purpose of the Invention> In view of these conventional problems, the present invention provides a system that allows the drive shaft and the driven shaft to smoothly and quickly shift to a lock-up state even when there is a certain degree of rotational speed difference between the drive shaft and the driven shaft. The purpose of this is to lengthen the lock amplifier time and further improve fuel efficiency.

<Configuration of the Invention> Therefore, as shown in FIG. 2, the present invention provides an operating condition detection means for detecting a predetermined operating condition that can be locked up for controlling a lockup solenoid, and an operating condition detection means that detects a predetermined operating condition that can be locked up, and an engine rotation speed and a turbine rotation speed. A rotation speed difference detection means for detecting the difference in rotation speed from the runner rotation speed, and an on-signal generator that continuously turns on the lock-up solenoid when the rotation speed difference is less than a first set value under predetermined operating conditions. and a duty signal transmitting means for intermittently turning on the lock-up solenoid when the rotational speed difference is greater than or equal to a first set value and less than a second set value under predetermined operating conditions.

<Example> Examples will be described below.

The configuration of the lock amplifier mechanism is as shown in FIG. Rotation speed sensors that detect each rotation speed (both not shown)
Allow the signal from to be input.

The software configuration of the microcomputer constituting the candlestick control unit 22 is as shown in the flowchart of FIG.

Explaining according to the flowchart in FIG. 3, operating conditions such as vehicle speed and gear position are read in S1, and it is determined in S2 whether these operating conditions are suitable for lock-up, that is, whether the vehicle speed is above a certain level, for example. . If it is not suitable, proceed to SIO and lock up solenoid 21.
is turned off and placed in a non-lockup state.

When operating conditions such as vehicle speed and gear position are in lock-up mode, the engine speed Ne is read in S3, and the engine speed Ne is read in S4.
The turbine rotational speed Nt is read in step S5, and the difference (absolute value) ΔN between Ne and NtO is calculated in step S5.

Then, in S6, it is determined whether the rotational speed difference ΔN is smaller than the first set value N+, and if it is smaller, the lock-up solenoid 21 is turned on in S7 to set the lock-up state.

If the rotation speed difference ΔN is equal to or larger than the first set value N1 in the determination in S6, it is determined in S8 whether the rotation speed difference ΔN is smaller than the second set value N2 (however, N2>Nl). , is small, a duty signal with a constant duty ratio (for example, 50%) is sent to the lock-up solenoid 21 in S9 to set it to a half-lock amplifier state, which will be described later.

That is, when a duty signal is applied to the lock-up solenoid 21 and it is turned on intermittently, the oil pressure in the pressure operating chamber I8 of the lock amplifier control valve I5 is controlled to an intermediate value, and the lock-up control valve 15 is moved to the left in the figure. Although it moves, it does not move completely, so the oil passage I4 is connected to the converter pressure introduction passage 16 and the drain passage 17 in a half-open state, and the pressure P2 in the chamber 13 does not completely decrease. Therefore, lock up plate 9
It is pressed against the inner wall of the case 2 with a weak force, resulting in a so-called half-clutched state. This is the semi-lock amplifier state.

If the rotational speed difference ΔN is equal to or larger than the second set value N2 as determined in S8, the process proceeds to SIO and the lock-up solenoid 21 is turned off to set the non-lock amplifier state.

Therefore, as shown in FIG.
As the turbine speed Nt approaches 1l, a half-lockup state occurs when the difference becomes smaller than N2, and as a result, the turbine speed Nt smoothly and quickly increases.
t is increased, and then when the difference becomes smaller than Nl, a normal lockup state is entered. Therefore, compared to the conventional characteristics shown by the broken line in Fig. 4, the turbine rotation speed Nt can be quickly brought close to the engine rotation speed Ne, and since this is done in a semi-locked-up state where slipping is possible, the rotation speed is smooth. It is possible to shift to the lock amplifier state. Therefore, it is possible to quickly shift from a state where there is a certain degree of rotational speed difference after a gear change to a day-up state to eliminate the rotational speed difference, and the lock-up time is lengthened accordingly, so that fuel efficiency can be improved.

<Effects of the Invention> As explained above, according to the present invention, it is possible to smoothly and quickly shift from a state where there is a difference in rotational speed to a lock-up state, thereby lengthening the lock-up time and improving fuel efficiency. The effect is that it is possible to achieve further improvements.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of an automatic transmission with a lock-up mechanism, Fig. 2 is a block diagram showing the configuration of the present invention, Fig. 3 is a flowchart showing an embodiment of the present invention, and Fig. 4 is an operation diagram. FIG. 3 is a diagram for explaining characteristics. l... Drive shaft 2... Case 3... Pump impeller 4... Driven shaft 5... Turbine runner 8...
・Clutch fading 9... Lockup play 1-11... Tarasochi hub 15... Lockup control valve 21... Lockup solenoid 22.
...Lockup Control Uni7t Patent Applicant Japan Electronics Co., Ltd. Agent Patent Attorney Fujio Sasashima

Claims (1)

[Claims] A lock amplifier plate l-, which faces the case of the torque converter rotated by the drive shaft on the engine side, is attached to the shaft of the turbine launch of the torque converter and is rotatable therewith and slidable in the axial direction; A lock-up control valve that controls hydraulic pressure that acts on the plate to move it in the axial direction, and a lock-up solenoid that turns on and off the hydraulic pressure for switching the lock-up control valve, and turns on the lock-up solenoid. In the lock amplifier control device for automatic transmissions for automobiles, which switches the lock-up control valve to a predetermined position and locks up by pressing the lock-up plate against the torque converter case, a lock-up control valve is used to control the lock-up solenoid. an operating condition detection means for detecting a predetermined operating condition; a rotation speed difference detection means for detecting a rotation speed difference between the engine rotation speed and the turbine runner rotation speed; On-signal transmitting means that continuously turns on the lock-up solenoid when the rotation speed is less than a set value, and turns on the lock-up solenoid intermittently when the rotation speed difference is greater than or equal to a first set value and less than a second set value under predetermined operating conditions. 1. A day-up control device for an automatic transmission for an automobile, characterized in that a duty signal transmitting means for transmitting a duty signal is provided.