WO2012092820A1

WO2012092820A1 - Thermal protection control method for automatic transmission box or stepless transmission box

Info

Publication number: WO2012092820A1
Application number: PCT/CN2011/084644
Authority: WO
Inventors: 倪斌
Original assignee: 奇瑞汽车股份有限公司; 芜湖普威技研有限公司
Priority date: 2011-01-04
Filing date: 2011-12-26
Publication date: 2012-07-12
Also published as: CN102080717B; CN102080717A

Abstract

A thermal protection control method for an automatic transmission box or a stepless transmission box. A control mechanism comprises a transmission box control unit (TCU) which carries out communication through a whole vehicle CAN bus, an engine management system (EMS) and an instrument panel module (ICM), and control steps thereof comprise: measuring the temperature of oil for the transmission box; comparing the measured temperature of the oil for the transmission box with a set high-temperature threshold; and when the temperature of the oil for the transmission box is higher or lower than a corresponding high-temperature threshold, executing a corresponding protection step. Through coordination work of the TCU, the EMS and the ICM, a system can carry out operations of warning, fan operation, speed ratio control, torque restriction and the like in time, thereby effectively preventing in time the temperature of the oil for the transmission box from rising too fast or too high and providing reliable protection to normal work of a transmission box transmission mechanism and a hydraulic system.

Description

Thermal protection control method for automatic transmission or continuously variable transmission

The invention relates to the technical field of thermal protection control of an automobile transmission, and particularly relates to a thermal protection control method for an automatic transmission or a continuously variable transmission. BACKGROUND OF THE INVENTION With the rapid development of electronic technology and automatic control technology, high-performance automotive automatic transmissions are constantly being introduced to the market by domestic and foreign automobile manufacturers, and automatic transmission models bring people a relaxed, comfortable and full driving process. Azimuth "driving fun" and other feelings and low fuel consumption, low emission performance have gradually been recognized, the market automatic transmission rate is getting higher and higher, making books

The scope of use is also wider and wider.

In automotive automatic transmissions consisting of a torque converter and a planetary gear train or a pulley shifting mechanism, ATF (Automatic Transmission Fluid) not only functions as a power transmission and hydraulic control, but also a transmission mechanism. Lubrication and cooling are important working media for automatic transmissions. When the automatic transmission vehicle is driving for a long time under high temperature or high gradient conditions, the automatic transmission system maintains high load operation, and the ATF oil temperature rises to high temperature too fast, resulting in poor lubrication of the transmission mechanism and excessive leakage of the hydraulic system. The working oil pressure of the clutch and the shifting system causes malfunctions such as abnormal shifting and slippage of the steel belt. Repeatedly, it can cause irreparable damage to key components such as clutch friction plates or metal belts, which not only causes great economic losses to customers, but also affects the safety and handling of the whole vehicle.

In the process of implementing the present invention, the inventors have found that the prior art has at least the following problems:

The existing automatic transmission or continuously variable transmission oil travels for a long time under high temperature or large gradient working conditions, and the oil temperature is likely to rise too fast, resulting in malfunction and damage of the vehicle, affecting the safety of the vehicle. And handling. Summary of the invention

In order to prevent the temperature of the gearbox oil from rising too high and to ensure the normal operation of the vehicle transmission mechanism and the hydraulic system when the vehicle is running for a long time under special working conditions, the embodiment of the invention provides an automatic transmission or a continuously variable transmission. Use thermal protection control methods.

The technical solution is as follows:

A thermal protection control method for an automatic transmission or a continuously variable transmission, the method comprising: Step a: The control mechanism measures the temperature of the oil for the transmission;

Step b: comparing the measured temperature of the gearbox oil with a set high temperature threshold Π ', Π, where Τ < Τ 1 ;

When the temperature of the gearbox oil is greater than Π, the TCU (Transmission Control Unit) sends a fan operation request to the EMS (Engine Management System) via the CAN (Controller Area Network) bus. , the engine management system), the EMS receives the fan operation request and starts the fan after controlling the self-test program by the fan;

When the temperature of the gearbox oil is lower than Τ, the TCU sends a fanless operation request to the EMS through the vehicle CAN bus, and the EMS receives the fanless operation request and turns off the fan after controlling the self-test program by the fan;

Wherein, the control mechanism comprises a TCU, an EMS and an ICM ( Instrument) that communicate via a vehicle CAN bus

Control Management, Dashboard Module). In order to better achieve the above object, the embodiment of the present invention further provides the following technical solutions: The control step may further include:

Step c: comparing the measured temperature of the gearbox oil with a set high temperature threshold T2' and T2, wherein TKT2' <T2;

When the temperature of the gearbox oil is greater than Τ2, the TCU sends a gearbox indicator request to the instrument panel module ICM through the vehicle CAN bus, and after receiving the gearbox indicator request, the ICM lights up the gearbox indicator and Flashing

When the temperature of the gearbox oil is lower than T2', the TCU sends out the gearbox indicator request to the ICM via the vehicle CAN bus, and the ICM receives the extinguishing gearbox indicator request and turns off the gearbox indicator. In order to better achieve the above object, the embodiment of the present invention further provides the following technical solutions: In the step c, the method further includes:

When the temperature of the gearbox oil is greater than T2, the TCU calculates a high-speed gear ratio according to the pedal opening degree, the vehicle speed and the gear position under the current working condition, and switches the speed ratio value to the high-speed position ratio;

When the temperature of the gearbox oil is lower than T2', the TCU switches the speed ratio to the preset normal driving gear down speed ratio and exits the high speed ratio control. In order to better achieve the above object, the embodiment of the present invention further provides the following technical solutions: The control step may further include:

Step d: comparing the measured temperature of the gearbox oil with the set high temperature valves 3T3' and T3, Where Π<Τ3, Τ3 or Τ2<Τ3, <Τ3;

When the temperature of the gearbox oil is greater than Τ3, the TCU sends the calculated torque limit request value to the EMS through the vehicle CAN bus, and the EMS receives the torque limit request value and arbitrates through the torque control system. The twist request value limits the output of the torque;

When the temperature of the gearbox oil is lower than T3', the TCU sends an infinite twist request to the EMS through the vehicle CAN bus.

After receiving the infinite twist request, the EMS exits the torque limit control of the engine. In order to better achieve the above object, the embodiment of the present invention further provides the following technical solutions: in the step b, the high temperature thresholds Τ and Π are recorded in the hysteresis comparator a;

When the temperature of the gearbox oil is greater than Π, the first output value of the hysteresis comparator a is 1, and the first output value is transmitted to the TCU;

When the temperature of the transmission oil is lower than Τ, the second output value of the hysteresis comparator a is 0, and the second output value is transmitted to the TCU. In order to better achieve the above object, the embodiment of the present invention further provides the following technical solutions: in the step c, the high temperature thresholds T2 ′ and T2 are recorded in the hysteresis comparator b;

When the temperature of the gearbox oil is greater than T2, the third output value of the hysteresis comparator b is 1, and the third output value is transmitted to the TCU;

When the temperature of the gearbox oil is lower than T2', the fourth output value of the hysteresis comparator b is 0, and the fourth output value is transmitted to the TCU. In order to better achieve the above object, the embodiment of the present invention further provides the following technical solutions: In the step d, the high temperature thresholds T3 ′ and T3 are recorded in the hysteresis comparator c;

When the temperature of the gearbox oil is greater than T3, the fifth output value of the hysteresis comparator c is 1, and the fifth output value is transmitted to the TCU;

When the temperature of the gearbox oil is lower than T3', the sixth output value of the hysteresis comparator c is 0, and the sixth output value is transmitted to the TCU. The technical solution provided by the embodiment of the invention has the beneficial effects that: when the vehicle is driving for a long time under special working conditions, the control system can timely perform alarm prompting, fan operation, and coordinated operation by the TCU, the EMS, and the ICM. Speed ratio control and torque limit operation, so that the temperature of the oil of the ih gearbox is raised too fast or too high in time and in time. The normal operation of the gearbox drive and hydraulic system provides reliable protection, ensuring that the gearbox is functioning properly, ensuring proper operation of the vehicle's transmission and hydraulic system. DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described. It is obvious that the drawings in the following description are only some embodiments of the present invention. Other drawings may also be obtained from those of ordinary skill in the art in view of the drawings.

1 is a schematic structural view of a control mechanism according to an embodiment of the present invention;

2 is a block diagram of a control principle of an embodiment of the present invention. detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

As shown in Figure 1 and Figure 2, the technical solution is:

A thermal protection control method for an automatic transmission or a continuously variable transmission, the control system comprising a TCU, an EMS and an ICM communicating via a vehicle CAN bus, the control steps comprising:

Step a: The control mechanism measures the temperature of the gearbox oil;

Step b: Compare the measured gearbox oil temperature with the set high temperature thresholds Τ and ,, and Π '<T1_; when the temperature of the gearbox oil is greater than Π, the TCU passes the fan through the vehicle CAN bus. The running request is sent to the EMS. After receiving the fan running request and controlling the self-test by the fan, the EMS starts to turn on the fan and performs air cooling control on the transmission cooling system.

When the temperature of the gearbox oil is lower than Τ, the TCU sends a fanless operation request to the EMS through the vehicle CAN bus. After the EMS receives the fanless operation request and controls the self-test program through the fan, the fan is controlled to be turned off.

Step c: Compare the measured gearbox oil temperature to the set high temperature thresholds T2' and T2, and

TKT2 ' <T2;

When the temperature of the gearbox oil is greater than Τ2, the TCU sends the gearbox indicator request to the ICM via the vehicle CAN bus. After receiving the gearbox indicator request, the ICM lights up the gearbox indicator and flashes, prompts and alarms for driving. The oil temperature is too high; at the same time, the TCU calculates the high-speed ratio based on the pedal opening, the vehicle speed and the gear position under the current working conditions, and switches the speed ratio to the high-speed ratio; by reducing the engine speed and torque under the same working conditions. Reduce the working load of the continuously variable transmission and achieve the purpose of cooling. When the temperature of the transmission oil is lower than T2 ', the TCU sends the request to the ICM through the vehicle CAN bus, and the ICM receives the request to extinguish the transmission indicator light, and then extinguishes the transmission indicator; meanwhile, the TCU will The speed ratio is switched to the preset normal driving gear down speed ratio, and the high speed ratio control is exited.

Step d: Compare the measured gearbox oil temperature with the set high temperature thresholds T3' and T3, and TKT3' <T3 or T2<T3, <Τ3;

When the temperature of the gearbox oil is greater than Τ3, the TCU calculates a reasonable torque limit value based on the current oil temperature and engine torque, and sends the limit torque request value to the EMS through the vehicle CAN bus. The EMS receives the request signal and passes the torque control system. After arbitration, limit the torque output according to the limit torque request value, and prevent the oil temperature from continuing to rise by reducing the actual driving power of the vehicle;

When the temperature of the gearbox oil is lower than T3', the TCU sends an infinite twist request to the EMS via the vehicle CAN bus. After receiving the infinite twist request, the EMS exits the engine's torque limit control.

In step b, the high temperature thresholds Τ and Π are recorded in the hysteresis comparator a;

When the temperature of the gearbox oil is greater than Π, its output value is 1, and the output value is transmitted to the TCU;

When the temperature of the gearbox oil is lower than Τ, its output value is 0, and the output value is transmitted to the TCU.

In step c, the high temperature thresholds T2' and T2 are recorded in the hysteresis comparator b;

When the temperature of the gearbox oil is greater than T2, its output value is 1, and the output value is transmitted to the TCU;

When the temperature of the gearbox oil is lower than T2 ', its output value is 0, and the output value is transmitted to the TCU.

In step d, the high temperature thresholds T3 ' and T3 are recorded in the hysteresis comparator c;

When the temperature of the gearbox oil is greater than T3, its output value is 1, and the output value is transmitted to the TCU;

When the temperature of the gearbox oil is lower than T3 ', its output value is 0 and the output value is transmitted to the TCU.

The above thermal protection control methods involve both active protection and passive protection. In terms of active protection, the driver can actively take effective driving methods to prevent the transmission from continuing to overheat through the alarm of the gearbox indicator. For passive protection, the TCU, EMS and other controllers can perform the hierarchical thermal protection control mode in time. Therefore, the automatic transmission vehicle using the thermal protection control function of the embodiment of the present invention can make the customer more secure and safe to use.

Among them, the transmission control unit TCU is the main controller, which is mainly responsible for the realization of the gearbox's own functions such as speed ratio control and thermal protection control; EMS performs fan start and stop control and torque output according to the fan operation request and torque limit request from the TCU. Control; The ICM performs transmission indicator control based on the transmission indicator request from the TCU. A person skilled in the art may understand that all or part of the steps of implementing the above embodiments may be completed by hardware, or may be instructed by a program to execute related hardware, and the program may be stored in a computer readable storage medium. The storage medium mentioned may be a read only memory, a magnetic disk or an optical disk or the like. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., which are within the spirit and scope of the present invention, should be included in the protection of the present invention. Within the scope.

Claims

Claim

A thermal protection control method for an automatic transmission or a continuously variable transmission, characterized in that the method comprises: Step a: The control mechanism measures the temperature of the oil for the transmission;

Step b: comparing the measured temperature of the gearbox oil with a set high temperature threshold Π ', Π, wherein Τ < Τ 1 ;

When the temperature of the transmission oil is greater than Π, the transmission control unit TCU sends a fan operation request to the engine management system EMS through the vehicle controller area network CAN bus, and the EMS receives the fan operation request and performs self-test through the fan control. After the program, start the fan;

When the temperature of the gearbox oil is lower than Τ, the TCU sends a fanless operation request to the EMS via the vehicle CAN bus.

The EMS receives the fanless operation request and turns off the fan after controlling the self-test program by the fan;

The control mechanism includes a TCU, an EMS, and a dashboard module ICM that communicate through a vehicle CAN bus.

2. The method of claim 1, wherein the method further comprises:

Step c: comparing the measured temperature of the transmission oil with a set high temperature threshold T2 ' and T2, wherein TKT2 ' < T2;

When the temperature of the gearbox oil is lower than T2', the TCU sends a command to extinguish the gearbox indicator to the ICM via the vehicle CAN bus. After receiving the request to extinguish the gearbox indicator, the ICM extinguishes the gearbox indicator.

The thermal protection control method for the automatic transmission or the continuously variable transmission according to claim 2, wherein in the step c, the method further includes:

When the temperature of the gearbox oil is lower than T2', the TCU switches the speed ratio to the preset normal driving gear down speed ratio and exits the high speed ratio control.

4. The thermal protection control method for an automatic transmission or a continuously variable transmission according to any one of claims 1 to 3, characterized in that The method further includes:

Step d: comparing the measured temperature of the gearbox oil with a set high temperature threshold T3 ' and T3, wherein TKT3' <T3 or Τ2<Τ3, <Τ3;

When the temperature of the gearbox oil is lower than T3', the TCU sends an infinite twist request to the EMS through the vehicle CAN bus. After receiving the infinite twist request, the EMS exits the torque limit control of the engine.

The thermal protection control method for an automatic transmission or a continuously variable transmission according to any one of claims 1 to 4, wherein in the step b, the high temperature threshold Τ and Π are recorded in hysteresis In a;

When the temperature of the transmission oil is lower than Τ, the second output value of the hysteresis comparator a is 0, and the second output value is transmitted to the TCU.

The thermal protection control method for an automatic transmission or a continuously variable transmission according to claim 2 or 3, wherein in the step c, the high temperature thresholds T2' and T2 are recorded in a hysteresis comparator b;

When the temperature of the gearbox oil is lower than T2', the fourth output value of the hysteresis comparator b is 0, and the fourth output value is transmitted to the TCU.

The thermal protection control method for an automatic transmission or a continuously variable transmission according to claim 4, wherein in the step d, the high temperature thresholds T3' and T3 are recorded in the hysteresis comparator c ;

When the temperature of the gearbox oil is lower than T3', the sixth output value of the hysteresis comparator c is 0, and the sixth output value is transmitted to the TCU.