JPS61130660A - Lock-up control system for automatic transmission - Google Patents

Abstract

PURPOSE:To suppress the temperature rise of operating oil even in the full open condition of accelerator by controlling the lockup at the time of kick-down in accordance with the temperature condition of operating oil. CONSTITUTION:When an accelerator is in the full open condition, the output signal of oil temperature sensor 51 is input in a microcomputer 53 to compare with a prescribed value. If the operating oil temperature of a torque converter 1 is greater than a prescribed value or in a high temperature, a lockup control signal is output by the microcomputer 53 to demagnetize a lockup control solenoid 9. Thus, the lockup operating condition can be maintained by the governor pressure supplied through a piping 12 in the llckup again.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lock-up control device for an automatic transmission.

(Prior art) As a conventional hydraulic circuit for an automatic transmission, there is a hydraulic circuit as shown in Fig. 5 (Nissan automatic transaxle maintenance manual PO2A type page 71 (February 1980, published by Nippon Motors)) ,,This is a forward 4 with automatic drive.
In the hydraulic circuit for fast reverse 1st speed, (D4→D,) indicates kickdown. 1 is a torque converter/9-torque, 2 is an oil pump, 3 is a low clutch, 4 is a high clutch, a 5-key rear clutch, 6 is a low-grade reverse gear, 7 is a torque converter regulator, 8 is a lock Up accumulator no. 9, 9 is lock-up control solenoid, 1
0 is lock-up timing pulp, 11 is lock-up control knob 9, 12 is detent & fail 7-f/
Serp% 13 is the throttle nozzle 214 is manual/no-ru f, 15t1 1 is 1 knee'/ng pulp, 16 is gas/Rsu/serzo, 17 is 1-2 shift nozzle, 18 is 2-3 shift nozzle Luzo,】9 is 3-4 shift pulse f120 is 3-2 downshift pulp, 21 is 3
-2 timing pulp, 22 is 2-4 timing knob, 23 is 4-3 timing knob, 24 #i8R timing knob, 25 is select timing knob, 26 is noseku-atsuzonoru, 27 is 4 -3-2 Day Ray No No Ruzo, 28 is Cut No No Tsuku No No Rub, 29
Fi pressure modifier knob, 30 is pressure regulator knob, 31 is 3rd gear vehicle speed output %, 32 is 4th gear vehicle speed connector, 33 is controller 1134 is low clutch accumulator knob , 35 is an OD release solenoid, and shuttle pulp 3
6,37°38.39,40. Chetsukunolup 41,
These are connected by piping with 42° and 43 interposed.

Then, at a specific shift position exceeding a set vehicle speed, the pump impeller 300, which is an input element of the torque converter 1, and the turbine runner 101, which is an output element, are mechanically connected to enter a lock-up operating state.

In other words, Da + D4 shift position exceeding the set vehicle speed (
lock-up region), and when the water temperature switch and accelerator fully closed switch (not shown) are OFF, the lock-up control solenoid 9 is OFF, and the line pressure of the arrangement 110 and 111 of the 3rd and 4th speed cutout nozzles 31 and 32 is The governor pressure as a counter pressure to the line pressure is acting through the pipe 112 from the gas/naparso 6, so that the lower side of the lock-up control nozzle 1 is connected through the pipe 113 or 1]8. Nonondosase 3
During kickdown in the lock-up region (accelerator opening approximately 7/7 8 or higher), the plunge input gear 120 of the fuel safety valve 12 pushes the detent connected to the accelerator pedal by a link mechanism as shown in FIG. Line pressure as pressure is applied to piping 117 and shuttle pulp 3
6 acts on the 3rd and 4th speed vehicle speed cut-offs 31 and 32, cuts off the line pressure supply to the lock-up timing nozzle lO through piping 113, 118, and controls lock-up through piping 113, 118. The line pressure supply to the nozzle 11 is cut off, and the plunger 121Fi of the lock-up control nozzle 11 is lowered by the spring force.

As a result, torque converter pressure is introduced into the lock-up chamber 102 of the torque converter 10 through the pipes 114, 115, and 116, releasing the lock-up.

(Problem to be Solved by the Invention) However, in such conventional hydraulic circuits for automatic transmissions, lock-up is always released at the time of kickdown, and the torque increasing effect of the torque controller 1 is utilized. At that time, the pump impeller 10
The problem is that there is a relative rotation difference between the turbine runner 101 and the turbine runner 101, which causes the hydraulic oil to be agitated, causing the temperature of the hydraulic oil to rise, which not only deteriorates the hydraulic oil but also causes a malfunction of the transmission. was there.

(Means and effects for solving the problems) In view of the above-mentioned conventional problems, the present invention controls the lock-up at the time of kick-down by controlling the temperature condition of the hydraulic oil.
This solution solves the above problem, and its configuration includes a torque converter in the power transmission system, and a lock-up control solenoid is controlled by a lock-up control signal to mechanically connect the input/output elements of the torque converter. A lock-up control device for an automatic transmission includes an accelerator full-open detection means for detecting the accelerator full-open position, an oil temperature detection means for detecting the temperature of hydraulic oil, a detection of the accelerator full-open position by the accelerator full-open detection means, and an oil temperature detection means for detecting the accelerator full-open position. This lock-up control device for an automatic transmission has means for detecting that the temperature of hydraulic oil is higher than a set value and for outputting a block-up control signal.

Therefore, even if the accelerator is fully open (kick down), the lock-up state is maintained as long as the temperature of the hydraulic fluid is higher than the set value, thereby suppressing the temperature increase due to stirring of the hydraulic fluid.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the arrangement of components according to an embodiment of the present invention, and the same parts as in the conventional system are given the same reference numerals. 50
Detent 17 is the part that is linked to the accelerator pedal.
The accelerator full-open switch, which is the accelerator full-open detection means provided on the fail-safe no-no-ruzo 12, detects the accelerator full-open position fi (approximately 7/8 opening degree or more) of the plunger 120 of the //or f12, and turns it on.

Outputs an OFF signal. 51 is a torque controller for detecting the temperature of hydraulic oil in a hydraulic circuit for an automatic transmission.
The hydraulic oil temperature is detected as an analog signal by an oil temperature sensor installed at the 5 oil temperature sensors installed.

Any oil temperature detection means such as an ON/OFF type switch that detects the set value may be used. And shuttle valve 36
The pipe 117 connecting the Detent Island Failsafe Nourso 12 is closed.

A microcomputer 53 outputs a lockup control signal to control the lockup control solenoid 9. The microcomputer 53 has a basic configuration consisting of an input section, an output section, a central processing section, and a storage section, and sends a processed signal to the lock-up control solenoid 9.

The flowchart of this invention is shown in FIG.
First, check the presence or absence of the detection signal of the fully open accelerator switch 5o (■). Accelerator fully open (kickdown state)
If so, the output signal of the oil temperature sensor 51 is converted into a digital signal via the A/D converter 54, inputted to the microcomputer 53, and compared with the set value. If the temperature of the hydraulic oil in the torque converter 1 is higher than the set value, that is, the temperature is higher than the set value, a lock-up control signal for maintaining the lock-up is output from the microcomputer 53 and the lock-up control solenoid 9 is demagnetized. This lockup control signal is maintained as long as the above conditions are met. In the lock-up region, the lock-up operating state is maintained by the governor pressure supplied from the pipe 112 (see FIG. 3).

If the temperature of the hydraulic oil is lower than the set value, a lock-up release signal is output from the microcomputer 53 [F],
The lock-up control solenoid 9 is energized and the line pressure opposite to the governor pressure in the pipe 112 is supplied to the 3rd and 4th vehicle speed cut nozzles 31 and 32 through the pipes 110 and 111 and the shuttle nozzle 36 to release the lock-up (
(See Figure 1.4).

If the accelerator is not fully open, the process shifts to other lock-up control conditions [F]. Here, other lock-up control conditions for releasing the lock-up in contrast to the basic operation of lock-up in the lock-up region include when the vehicle is traveling at a speed higher than the set speed, when the accelerator is fully closed, when the hydraulic oil temperature is lower than a predetermined value, etc. be. If the vehicle is coasting at a speed higher than the set speed, engine vibrations are transmitted to the vehicle body through the power transmission system rather than maintaining lockup, causing jerky vibrations and worsening ride comfort. The number of fuels increases and fuel consumption worsens. Therefore, it is desirable to detect this coasting driving state (accelerator fully closed state) and release the lockup. Next, when the hydraulic oil temperature is low, shift shock is likely to occur in the automatic transmission, and the shock is transmitted to the vehicle body via the locked-up torque converter.
Furthermore, in a torque converter in a locked-up state, the agitation effect of the hydraulic oil decreases, preventing the oil temperature from rising. Therefore, it is desirable to release the lockup by detecting a drop in the temperature of the hydraulic oil.

In the embodiment described above, even if the electrical system breaks down, the hydraulic circuit will not be affected, so the 3, 4-speed cut A loop 31,
The lock-up can be released by lowering the pressure through the pipe x12'# to 32, and even if the hydraulic circuit breaks down, the electric circuit will not be affected, so the lock-up control solenoid 9 can be energized. By supplying line pressure opposite to the governor pressure acting on the pipe 112 to the 3rd and 4th speed vehicle speed cut valves 31 and 32, the lockup can be released. Therefore, fewer electrical or hydraulic circuits (
As long as one of the two is functioning normally, it is possible to avoid a constant lock-up state in which the other is unable to run, which is advantageous in terms of fail-safety.

It goes without saying that the present invention can be applied to a lock-up control device having a structure in which the lock-up control valve is controlled by the lock-up release state or by demagnetizing the lock-up control solenoid.

(Effect of the invention) As understood from the above explanation, according to this invention,
Even when the accelerator is fully open (kick down), the lock-up state is maintained as long as the hydraulic oil temperature is higher than the set value, and the temperature rise of the hydraulic oil is suppressed, resulting in deterioration of the hydraulic oil, malfunction of the transmission, etc. You can get the effect of being able to avoid it.

[Brief explanation of drawings]

FIG. 1 is a layout diagram of components according to an embodiment of the present invention;
FIG. 2 is a flowchart, FIG. 3 is an explanatory diagram showing the lock-up operating state, FIG. 4 is an explanatory diagram showing the energizing state of the lock-up control solenoid, and FIG. #g5 is a circuit diagram showing the conventional structure. l: Torque converter, 7: Torque converter regulator valve, 9: Lock-up control solenoid,
lO2 lock-up timing I/rev, 11; lock-up control pulp, 12: detent fail-safe pulp, 13: throttle valve, work 6: gap/rozo, 3 to 3rd speed vehicle speed cut valve, aZ: 4th speed vehicle speed Katsutonoruso, 36: Shuttle pulp, 50: Accelerator full open switch (accelerator full open detection means), 51: Oil temperature sensor (oil temperature detection means), 53: Microcomputer, 1
00: Pump impeller (input element), 101: Turbine runner (output element), 102: Lock-up chamber, 111
゜11! , 114, 115, 116, 117: Piping,
120: Zoranja agent Patent attorney front 1) Toshiyuki ~ Figure 2 +12

Claims (1)

[Claims] 1. In a lock-up control device for an automatic transmission that includes a torque converter in the power transmission system and mechanically connects the input/output elements of the torque converter by controlling a lock-up control solenoid using a lock-up control signal, the fully open position of the accelerator is detected. Lock-up is achieved by a fully open accelerator detecting means, an oil temperature detecting means detecting the temperature of the hydraulic oil, a fully open accelerator position being detected by the fully open accelerator detecting means, and a fact that the temperature of the hydraulic oil is higher than a set value by the oil temperature detecting means. 1. A lock-up control device for an automatic transmission, comprising means for outputting a control signal.