JPS62137467A - Lockup control device of automatic transmission - Google Patents

Abstract

PURPOSE:To eliminate incompatible feeling with the driving condition after an engine is warmed up and improve fuel economy by changing vehicle speed range where lockup action is performed to a vehicle speed range which is higher than normal. CONSTITUTION:A lockup control means 05 is arranged for performing lockup control based on a lockup schedule determined by both a vehicle speed condition and an engine output condition. The lockup control means 05 is provided with a temperature sensor 06 as an input sensor in a drive train of an engine. It is further made to perform the lockup control by making the drive train directly connected in a speed range higher than normal when a temperature signal showing a cold engine is inputted. With this constitution, incompatible feeling with the driving condition after the engine is warmed up can be eliminated and fuel economy is also improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a lock-up control device for an automatic transmission that performs lock-up control of a fluid coupling such as a torque converter used in an automatic transmission under predetermined control conditions. Regarding.

(Prior Art) Conventionally, as a lock-up control device for an automatic transmission, for example, there is a lock-up control device as described in "Nirasan Automatic Transaxle Maintenance Request Form (FOZA Type)" (published by Nissan Motor Co., Ltd. on February 9, 1980). devices are known.

As shown in FIG. 7, this conventional device includes a torque converter 1001 having a two-way up crank 1000;
A lock-up control valve 1002 that activates or de-activates the lock-up and pull-crunch 10oO, and a 3rd speed vehicle speed cant valve 1 that determines the lock-up vehicle speed in 3rd gear.
003, a 4th speed vehicle speed cut valve 1004 that determines the lockup vehicle speed in 4th gear, and a lockup timing valve 1005 that instantly releases the long-up mode together with the lockup control valve 1002 and prevents shift shock during 3H4 shifting. Lock-up control solenoid valve 100 that inhibits lock amplifier when energized
6, an engine coolant temperature sensor 1007, and a control unit 1008. Therefore, in this conventional device, the shift schedule and lock-up schedule shown in FIG. The lock-up is activated when the vehicle speed exceeds the specified speed.

Note that during lockup, converter pressure is supplied only to the torque converter chamber, and the lockup clutch 1000 is engaged, as shown in FIG.

Furthermore, in 3rd and 4th gears, even if the vehicle speed and accelerator opening are within the lock-up range, if a signal indicating a coolant temperature of 50°C or less is input from the engine coolant temperature sensor 1007, An energization signal is output from the control unit 1008 to the lock-up control solenoid valve 1006, and as shown in FIG. 8, the lock-up is controlled by supplying converter pressure to both the torque converter chamber and the lock-up clutch chamber. It is forbidden.

(Problem to be Solved by the Invention) However, in such a conventional lock-up control device, lock-up is prohibited even when driving at high speed unless the engine cooling water temperature reaches 50°C or higher. Because of this, the noise and driving performance felt very strange compared to the driving condition after the engine warmed up.
Moreover, there was a problem in that it was inferior in terms of fuel efficiency.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and to achieve this purpose, the present invention employs the following solving means.

The solution of the present invention will be explained with reference to the conceptual diagram of the claim shown in FIG. A lock-up control device for an automatic transmission comprising a lock-up means 4 for directly connecting the lock-up means 4 and a lock-amp control means 5 for controlling the lock amplifier based on a lock-up schedule determined by vehicle speed conditions and engine output conditions. Lockup control means 5
As an input sensor, a temperature sensor 6 provided in the engine drive system is included, and the input surface of the temperature signal indicating when the engine is cold is provided with a lock-up control means 5 for performing lock-up control to directly connect the drive at a higher speed than usual.

(Function) Therefore, in the lock-up control device for an automatic transmission of the present invention, instead of prohibiting the long amplifier operation when the engine is cold, as described above, the lock-up operation is performed in a vehicle speed region higher than normal. By using a means of control to change the speed to the previous one, it eliminates the feeling of discomfort with the driving state after the engine has warmed up, and if the engine enters a high-speed driving state within a short period of time after starting the engine, the lock-up operation will be activated. This can also improve fuel efficiency.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In describing this embodiment, a lock-up control circuit incorporated in a hydraulic control device used in an automatic transmission of an automobile will be taken as an example.

First, the configuration of the embodiment will be explained.

As shown in FIG. 2, the lock-up control circuit A of the embodiment includes a torque converter (Ii body joint) 10° lock-up clutch (lock-up means) 11, and an oil pump O.
/P, pressure regulator valve 1, torque converter regulator valve 2, lock-up valve 3. Pilot valve 4, lock-up solenoid valve 5,
It is equipped with an input sensor 6 and a control unit 7.

The torque converter 10 is a type of fluid coupling provided between the crankshaft (engine output 1b) 12 and the transmission input shaft (auxiliary transmission input shaft) 13, and connects the pump impeller 14, turbine runner 15, and stator 16. This is a three-element, two-phase, one-stage torque converter.

The converter chamber 17 of the torque converter 10 is constantly filled with hydraulic oil at torque converter pressure from the torque converter/heater regulator valve 2.

The lock-up clutch 11 is provided between the drive input section and the drive output section of the i-lux converter 10, and is a friction clutch means that directly connects the crankshaft 12 and the transmission input shaft 13 when the clutch is engaged. be.

The lock-up clutch chamber 19 formed between the lock-up clutch 11 and the converter shell 18 is supplied with converter pressure hydraulic oil from the lock-up valve 3 when the clutch is not engaged, and is activated when the clutch is engaged. Oil is drained.

The oil pump O/P uses a variable displacement vane pump-1, and the oil chamber C/C of the control cylinder is
It is connected to the oil passage 701 (feedback pressure oil passage) from the pressure regulator valve 1, and the position of the cam ring is controlled so that the pump discharge amount is constant above a predetermined rotation, eliminating excess flow at high rotation. The aim is to reduce energy consumption.

Pressure regulator valve l is oil pump O/
This valve has the function of adjusting the oil discharged from P to the optimum pressure (line pressure) depending on the driving condition and gear shift position.

In terms of configuration, a valve hole 101 having boats 101a to 101g, and a land 201a corresponding to the valve hole 101.
Axially movable spoo with ~201d/l/20
1 and a valve hole 101 having boats 3ola to 3o1c.
A sleeve 301 fixed therein, a plug 401 that has lands 401a to 401c corresponding to the inner diameter of the sleeve 301 and is movable in the axial direction, a spring seat 501 disposed at the top of the plug 401 in the drawing, and a spring seat. 501 and a spring 601 provided between the land 201d of the spool 201.

Lands 201b, 201c, and 20 of spool 201
1d have the same diameter, and the diameter of land 201a is smaller than these land diameters. Land 401a of plug 4゜1
has a larger diameter than the land 401b.

Bo) 101a, 1o1c, iolg, 30
1c is a drain boat. Boats 101b and 10
1e is connected to an oil passage 700 (line pressure oil passage) through which the pressure-regulated oil discharged from the oil pump O/P flows, and an orifice 800 is provided at the inlet of the bow 101b. The boat 101d is connected to an oil passage 701 (feedback pressure oil passage) that communicates with the oil chamber C/C of the oil pump O/P. 101f is the oil passage 702 (
) is connected to the lux converter pressure oil line). boat 3
01a is connected to an oil passage 705 (cutback pressure oil passage). The bow) 301b is connected to an oil passage 706 (throttle modifier pressure oil passage).

Spool 201 of this pressure regulator valve 1
, a force due to the line pressure acts on the boat 101b as a force pushing it downward in the drawing, a force acting on the spring 601 as a force pushing it upward in the drawing, a force due to cutback pressure on the boat 301a, and a force acting on the boat 301b. The force due to the pressure modifier pressure is applied. The spool 201 is operated by the balance of these forces, and when the oil pressure of the boat 1o1b gradually increases and becomes thicker than the upward force, the oil in the boat 101e flows toward the torque converter 10. The pressure in the boat 101e decreases until it balances the upward force. This drop in the pressure of the boat 101e also reduces the pressure of the boat 101b, which is communicated with the oil passage 700, so that the downward force is reduced and the spool 2
01 is pushed back upwards. In this way, spool 2
By repeating the vertical movement of 01, the boat 1O1
The oil pressure of b, that is, the oil pressure of the oil passage 700, is always regulated to balance the upward force, and so-called line pressure is obtained. Note that since the force exerted by the spring 601 is constant, the line pressure changes in accordance with the upward force exerted by the plug 401.

Torque converter regulator valve 2 is a valve that has the function of preventing torque converter pressure delivered to torque converter 10 from becoming too high.

Structurally, a valve hole 102 having bows) 102a to 102e, and a land 202 corresponding to the help hole 102.
a and 202b, and a spool 202 that is axially movable and has a communication path 202C formed therein;
2 downward in the drawing.

Boats 102a and 102b are drain boats.

Boats 102c and 102d are connected to oil passage 702 (torque converter pressure oil passage).

The boat 102e is connected to an oil passage 702 via a communication passage 202c.

A spring force from a spring 302 acts on the spool 202 of the torque converter regulator valve 2 in a downward direction in the drawing, and a force due to torque converter pressure acts in an upward direction in the drawing.

Therefore, the spool 202 repeatedly moves to a position where the vertical forces are balanced due to changes in the torque converter pressure, and the upper limit pressure of the torque converter pressure reaches a predetermined pressure while receiving a pressure reducing effect due to communication with the boat 102b, which is a drain boat. stipulated.

Note that the torque converter pressure supplied to the converter chamber 17 of the torque converter 10 is drained after passing through an oil cooler and a lubricating section.

The lock-up valve 3 is operated by a control signal (C) sent to the lock-up solenoid valve 5, and is a valve that controls the operation/non-operation of a lock-up clutch provided in the torque converter 10.

In terms of configuration, a valve hole 103 having boats 103a to 103g, and a land 203a corresponding to the valve hole 103.
-203d and an axially movable spool 203;
A sleeve 303 is provided on the land 203d of the spool 203.

Lands 203a and 203d are similar to lands 203b and 20
The diameter is smaller than that of 3c.

Boats 103a and 103c are drain boats, and an orifice 801 is provided at the exit of boat 103c. Boats 103b and 103c are connected to oil line 702 (torque converter pressure oil line), and boat) 10
An orifice 802 is provided at the entrance of 3b. Boats 103d and 103f are connected to oil passage 703 (lock-up clutch pressure oil passage). (bow) 103g is connected to an oil passage 704 (pilot pressure oil passage) having an orifice 803.

When the control signal (C) to the lock-up solenoid valve 5 is an OFF signal, the lock-up solenoid valve 5
is in the valve open state, the pilot pressure from the oil passage 704 does not act on the spool 203, and the spool 203 is in the lower position in the drawing due to the force due to the torque converter pressure from the boat 103b. Therefore, boat 103e and boat 103
d is in communication with the lock-up clutch chamber 1, and the torque converter pressure from the oil passage 702 is directly transmitted to the lock-up clutch chamber 1 via the oil passage 703.
9, and the lock-up clutch 11 becomes inactive.

t, the control signal to the lock-up remade valve 5 (
When C) is an ON signal, the lock-up solenoid valve 5 is in the valve closed state, and the valve is released from the oil passage 704.
Pyro-/) pressure is introduced to 103g, and the spool 203
is pushed upward in the drawing, and the boat 103d communicates with the boat 103c, which is a drain boat, to reduce the pressure in the oil passage 703.

This pressure drop in the oil passage 703 causes the pressure balance between the converter chamber 17 and the lock-up clutch chamber 19 at the left and right positions of the lock-up clutch 11 to collapse, and the torque converter pressure causes the lock-up clutch 11 to be in the operating state yE (engaged state IE). becomes.

The pilot valve 4 is the lock-up valve 3 marked 1r
This is a valve that has the function of creating valve operating pressure (pilot pressure).

Structurally, it has bow holes 104a to 104d, a help hole 104, and a land 204 corresponding to the valve hole 104.
a and 204b, and a communicating path 204C that communicates the end surface of the land 204b with the boats 104C and 104d into which line pressure is input, and the spool 204 is movable in the axial direction, and the spool 204 is urged downward in the drawing. A spring 304 is provided.

Boats 104a and 104b are drain boats.

The boat 104c is connected to the oil passage 704 via the strainer 404.
(Pilot pressure oil line). Bo) 104
d is connected to an oil passage 700 (line pressure oil passage).

A spring force from a spring 304 acts on the spool 204 of this pilot valve 4 in a downward direction in the drawing.
Force due to line pressure acts upward in the drawing. Therefore, due to the balance of this vertical force, the boat 104d into which line pressure is introduced repeats opening and closing, and the line pressure from the boat 104d is reduced in the boat 104c.
Pressure fluctuations are reduced by the strainer 404, and oil at a pressure suitable for valve operation is delivered to the oil passage 704, which is a pilot pressure oil passage.

The lock-up solenoid valve 5 is a valve operated by a control signal (C) from the control shaft 7, and consists of a valve solenoid 105, a valve member 205, and a valve seat 30 having a boat 305a.
5 and a drain 'Jth path 405.

Operationally, the control signal (C) is an ON signal and the valve member 2
05 closes the boat 305a, and the OFF signal causes the valve member 205 to separate from the valve seat 305.

The control unit 7 uses an on-vehicle microcomputer, and includes an input circuit 107, a RAM (random access memory) 207, a ROM (read only memory) 307, a CPU (central processing unit) 407, and a clock. It includes a circuit 507 and an output circuit 607.

As the input sensors 6, a vehicle speed sensor 106, an accelerator opening sensor 206, an engine coolant temperature sensor 306, and a gear position sensor 404 are provided.

The input circuit 107 is a circuit that converts the human power signals (v), (0), (t), and (p) from the input sensor 6 into signals that can be processed by the CPU 407.

The RAM 207 is a readable and writable memory, and input signals are written therein, and information is written in the middle of calculations by the CPU 407.

The ROM 307 is a read-only memory,
Information necessary for arithmetic processing by the CPU 407 is stored in advance, and is read out from the CPU 407 as needed.

The CPU 407 is a device that performs arithmetic processing on various input information according to predetermined processing conditions.

The clock circuit 507 is a circuit that sets the calculation processing time of the CPU 407.

The output circuit 607 is a circuit that outputs a control signal (C) to the valve solenoid 105 based on a calculation result signal from the CPU 407.

The vehicle speed sensor 106 is a sensor that detects the vehicle speed ■ and outputs a vehicle speed signal (V) corresponding to the vehicle speed V.

Accelerator opening sensor (also called throttle opening sensor)
A sensor 206 detects the accelerator opening degree A caused by pressing the accelerator pedal and outputs an accelerator opening signal (a) corresponding to the accelerator opening degree A.

The engine coolant temperature sensor 306 is a sensor that detects the temperature T of the engine coolant and outputs a temperature signal (1) according to the coolant temperature T.

The gear position sensor 406 is a sensor that detects the gear position m (gear position) in the transmission and outputs a gear position signal (p).

Note that the ROM 307 of the control unit 7 has the following information:
Control characteristic maps of shift schedules and lock-up schedules set in the relationships shown in FIG. 3 (up-shifting) and FIG. 4 (downshifting) are stored in advance, and the control characteristic maps shown in FIG. 5 are stored in advance. As shown, it is also stored in the correction value of the vehicle speed ■ according to the cooling water temperature T, and this correction value includes 0.5 when the temperature is low up to the set temperature To, and 0.5 when the temperature is high above the set temperature 10. = 1.

Next, the operation of the embodiment will be explained.

First, the lock-up control operation of the embodiment will be described with reference to the flowchart shown in FIG.

, the flow of control operation after starting the engine is step 50→
The process goes to step 51 → step 52 → step 53 → step 54. In step 54, it is determined whether the vehicle is in the lock-up area based on the corrected vehicle speed A, the accelerator opening A, and the gear position P. If it is not in the lock-up area, the process goes to step 55. If it is a lockup area, the process advances to step 56.

Note that step 50 is an input signal (V).

This is the reading step of (a), (t), and (p). In step 51, it is determined whether it is shift door, gear shift or downshift by comparing with the previous gear position, etc., and based on this determination, the control characteristic map Mu shown in FIG. 3 or the control characteristic map Mu shown in FIG. 4 is selected. This is a selection step of selecting one of Md. In step 52, a correction value K is read from the correction value map shown in FIG. 5 based on the temperature signal (1) from the engine coolant temperature sensor 306, and a correction vehicle speed v'( V'=K・
(2) This is the calculation step. Step 53 is a search step in which, based on the control characteristic map selected based on the corrected vehicle speed V'', the accelerator opening A, and the gear position P, the position of the vehicle state in the map at that time is searched. Step 54 is a judgment step in which it is determined whether the position searched in step 53 is a lock-up area or a non-lock-up area.Step 55 is a judgment step in which a control signal (c) is sent to the valve solenoid 105 by an OFF signal.
Step 56 is an output step in which a control signal (C) based on an ON signal is outputted to the pulp solenoid 105 to set the lockup in an operating state.

Therefore, when the engine is cold for a while after the engine starts and the engine cooling water temperature is below the set temperature,
The corrected vehicle speed V* becomes lower than the actual vehicle speed V due to the correction value K, and if judged based on the actual vehicle speed V, it is in the lock-up area, but if judged based on the corrected vehicle speed V7, it is out of the lock-up area, and the engine is actually cold. This is the same as changing the lockup area to a faster area than normal.

In other words, when the engine is cold, the lock-up operation is not performed at all, but when the corrected vehicle speed v7 reaches the lock-up vehicle speed due to high-speed driving, the lock-up operation is performed even when the engine is cold.

In this manner, in the lock-up control device of the embodiment, although the same control characteristic map is used, the region in which lock-up is performed is changed to a vehicle speed region higher than normal by correcting the vehicle speed V. Since the configuration is configured to perform control, it eliminates the feeling of discomfort with the driving state after the engine has warmed up, and if the engine enters a high-speed driving state within a short time after starting, a lock-up operation is performed, which reduces fuel consumption. It will also be improved in terms of aspects.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. included.

For example, in the embodiment, an engine cooling water temperature sensor is shown as a temperature sensor, but an oil temperature sensor for automatic transmission hydraulic oil,
The sensor is not limited to the embodiments as long as it is a sensor that is provided in the engine drive system and can detect when the engine is cold or when the engine is warmed up, such as a catalyst temperature sensor for a catalyst provided in the exhaust system.

In addition, in the embodiment, a control example was shown in which a lock-up region higher than usual is obtained when the engine is cold by correcting the vehicle speed using different correction values for vehicle speed at low temperature and high temperature. The map may have a characteristic that provides a correction value that increases steplessly from low to high temperatures, or multiple control characteristic maps such as a map for low temperatures and a map for high temperatures as shown in Figures 3 and 4 may be set. Then, the map may be selected from among a plurality of maps based on the detected temperature, and the control may be performed based on the selected map.

(Effects of the Invention) As explained above, in the lockup control device for an automatic transmission of the present invention, instead of prohibiting lockup operation when the engine is cold, the lockup operation region is set to a higher speed than normal. Since the vehicle speed is controlled to change to a vehicle speed range of This has the effect of improving fuel efficiency.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a claim showing a lock-up control device for an automatic transmission of the present invention, FIG. 2 is a diagram showing a lock-up control device of an embodiment of the present invention, and FIG. 3 is a shift schedule and a lock-up schedule during upshifting. Fig. 4 is a control characteristic map showing the shift schedule and lock-up schedule during downshifting, Fig. 5 is a vehicle speed correction value map, and Fig. 6 is the control unit installed in the example. Flowchart diagram showing the flow of lock-up control operation, No. 7
8 and 8 are diagrams showing a conventional lock-up control device,
FIG. 9 is a control characteristic diagram showing a shift schedule and a lock-up schedule of a conventional device. 01...Engine output shaft 02...Auxiliary transmission input shaft 03...Fluid coupling 04...Lockup means 05...Lockup control means 06...Temperature sensor

Claims (1)

[Claims] 1) A fluid coupling provided between the engine output shaft and the auxiliary transmission input shaft, a lockup means for directly connecting the input and output shafts of the fluid coupling, and vehicle speed conditions and engine output. A lockup control device for an automatic transmission, comprising: lockup control means for performing lockup control based on a lockup schedule determined by conditions; A lock-up control device for an automatic transmission, characterized in that the lock-up control device includes a temperature sensor that indicates when the engine is cold, and has lock-up control means that performs lock-up control to directly connect the drive at a higher speed than normal when a temperature signal indicating that the engine is cold is input. .