阅读说明：本技术 一种急刹车工况下液力变矩器的控制方法 (Control method of hydraulic torque converter under emergency brake working condition ) 是由 刘强 高龙 曹永� 宗伟 郭太民 杨磊 王洪志 吴玉德 王圣涛 李志宗 于 2020-08-04 设计创作，主要内容包括：本发明公开了一种急刹车工况下液力变矩器的控制方法,包括液力变矩器处于闭锁状态,监测变速箱挡位信号、获取转速信号并计算出转速变化率,转速变化率达到一定值后强制打开液力变矩器,通过监测挡位和刹车程度,提前强制打开液力变矩器,采用压力补偿和时间补偿控制液力变矩器打开,在保护发动机不熄火的前提下,最大限度的保证驾驶的安全性和舒适性。(The invention discloses a control method of a hydraulic torque converter under a sudden braking working condition, which comprises the steps that the hydraulic torque converter is in a locking state, a gear signal of a gearbox is monitored, a rotating speed signal is obtained, a rotating speed change rate is calculated, the hydraulic torque converter is forcibly opened after the rotating speed change rate reaches a certain value, the hydraulic torque converter is forcibly opened in advance by monitoring the gear and the braking degree, the hydraulic torque converter is controlled to be opened by adopting pressure compensation and time compensation, and the safety and the comfort of driving are ensured to the maximum extent on the premise that an engine is protected from being extinguished.)

1. A control method of a hydraulic torque converter under a sudden braking working condition is characterized by comprising the following steps: comprises that

The hydraulic torque converter is in a locked state, a gear signal of the gearbox is monitored, a rotating speed signal is obtained, the rotating speed change rate is calculated, and the hydraulic torque converter is forcibly opened after the rotating speed change rate reaches a certain value;

comprises that

Step 101, start, then enter step 102;

step 102, judging whether the hydraulic torque converter is in a locked state, if so, entering step 103, otherwise, entering step 108;

103, acquiring a gear signal of the gearbox from TCU software, and entering step 104;

step 104, acquiring a rotating speed signal from an output shaft sensor, and entering step 105;

step 105, calculating the change rate of the rotating speed according to the rotating speed signal, and entering step 106;

step 106, judging whether the change rate of the rotating speed reaches the limit value of forcibly opening the hydraulic torque converter or not by combining the gear of the gearbox, if so, entering step 107, otherwise, returning to step 103;

step 107, turning on the hydraulic torque converter, and then entering step 108;

and step 108, ending.

2. The method for controlling the torque converter under the condition of sudden braking as claimed in claim 1, wherein: in step 106, the limit for forcing the torque converter on is:

when the gear of the gearbox is 1 gear and 2 gears, and the change rate of the rotating speed is lower than minus 180rpms, the hydraulic torque converter enters an open state;

when the gear of the gearbox is 3, 4 or 5, and the change rate of the rotating speed is lower than-400 rpms, the hydraulic torque converter enters an open state;

and when the gear of the gearbox is 6 gears and 7 gears, and the change rate of the rotating speed is lower than-500 rpms, the hydraulic torque converter enters an open state.

3. The method for controlling the torque converter under the condition of sudden braking as claimed in claim 1, wherein: in step 107, the torque converter control from lockup to lockup includes time compensation and pressure compensation.

4. A method of controlling a torque converter in a hard braking condition as claimed in claim 3, wherein: when the gear is fixed, the smaller the change rate of the rotating speed is, the larger the pressure compensation value is, and P_dropThe smaller the value; when the rotating speed change rate is the same, the lower the gear is, the larger the pressure compensation value is, and P_dropThe smaller the value;

when the gear is fixed, the smaller the change rate of the rotating speed is, the larger the time compensation value is, and T_P2The smaller the value; when the change rate of the rotating speed is constant, the lower the gear is, the larger the time compensation value is, and T_P2The smaller the value.

5. The method for controlling the torque converter under the condition of sudden braking as claimed in claim 4, wherein: in 1 gear, when the rotating speed change rate is between-500 and-180 rpms, the pressure compensation value range is between-1.5 and-0.5 bar,P_dropin the range [ 0, 1 ] bar;

in gear 2, when the speed change rate is between-500 and-250 rpms, the pressure compensation value range is between-1.5 and-0.5 bar, P_dropIn the range [ 0, 1 ] bar;

in 3 gear, when the rotation speed change rate is between-500 and-400 rpms, the pressure compensation value range is between-1 and-0.5 bar, P_dropIn the range [ 0.5, 1 ] bar;

in 4-gear, when the change rate of the rotating speed is [ - ∞ -500 ] rpms, the pressure compensation value is-0.5 bar, P_dropIs 1 bar.

6. The method for controlling the torque converter under the condition of sudden braking as claimed in claim 4, wherein:

in 1 gear, when the change rate of the rotating speed is between-500 and-180 rpms, the time compensation value is between-500 and-300 ms, and T_P2Is [ 0,200 ] ms;

in gear 2, when the change rate of the rotating speed is between-500 and-250 rpms, the time compensation value is between-500 and-100 ms, and T_P2Is [ 0,400 ] ms;

in 3 gear, when the change rate of the rotating speed is between-500 and-400 rpms, the time compensation value is between-300 and-100 ms; t is_P2Is [ 200,400 ] ms;

in 4-gear, when the change rate of the rotating speed is [ - ∞ -500 ] rpms, the time compensation value is-100 ms, T_P2Is 400 ms.

Technical Field

The invention belongs to the technical field of hydraulic torque converter control methods, and particularly relates to a control method of a hydraulic torque converter under a sudden braking working condition.

Background

The working state of the hydraulic torque converter has two working conditions of opening and locking, the prior art mainly realizes opening and locking through the control chart of the hydraulic torque converter, and when the working state is the opening state, the torque increasing effect can be achieved, the power performance is improved, the flexible connection is adopted, the efficiency is lower due to oil liquid transmission, and the opening working condition is generally used for starting at a low gear (1 gear and 2 gears) of a vehicle or accelerating a large oil door. When the engine is in a locking state, a locking clutch inside the engine enters a locking working condition, the power of the engine can be transmitted to the transmission by 100%, the efficiency is high, but the engine belongs to hard connection at the moment and cannot play a role in increasing torque, the locking working condition is generally used for normal driving of a high gear (3 gears and above), and the using working condition and the using period are long.

In the process of implementing the invention, the inventor finds that the prior art has the following defects: under the working condition that the hydraulic torque converter is switched from locking to opening, if the pressure is reduced too fast, compared with the whole power system, the whole power system has no transition period from hard connection to soft connection, and the problem of vehicle-skipping can occur in the whole vehicle; if the engine is in a low gear, the vehicle speed is static or very low, the engine speed is reduced, even the engine is pulled to be flameout, if the pressure is reduced too slowly, the unlocking is not timely, and the potential safety hazard of engine flameout exists.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a control method of a hydraulic torque converter under the condition of emergency braking, overcome the defects in the prior art and ensure the driving comfort to the maximum extent on the premise of protecting the engine from extinguishing fire.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a control method of a hydraulic torque converter under a sudden braking working condition comprises the steps that the hydraulic torque converter is in a locking state, a gear signal of a gearbox is monitored, a rotating speed signal is obtained, a rotating speed change rate is calculated, and the hydraulic torque converter is forcibly opened after the rotating speed change rate reaches a certain value.

Preferably, step 101 is included, the method starts, and then step 102 is entered;

step 102, judging whether the hydraulic torque converter is in a locked state, if so, entering step 103, otherwise, entering step 108;

103, acquiring a gear signal of the gearbox from TCU software, and entering step 104;

step 104, acquiring a rotating speed signal from an output shaft sensor, and entering step 105;

step 105, calculating the change rate of the rotating speed according to the rotating speed signal, and entering step 106;

step 106, judging whether the change rate of the rotating speed reaches the limit value of forcibly opening the hydraulic torque converter or not by combining the gear of the gearbox, if so, entering step 107, otherwise, returning to step 103;

step 107, turning on the hydraulic torque converter, and then entering step 108;

and step 108, ending.

Preferably, in step 106, the limit for forcing the torque converter to open is: when the gear of the gearbox is 1 gear and 2 gears, and the change rate of the rotating speed is lower than minus 180rpms, the hydraulic torque converter enters an open state;

when the gear of the gearbox is 3, 4 or 5, and the change rate of the rotating speed is lower than-400 rpms, the hydraulic torque converter enters an open state;

and when the gear of the gearbox is 6 gears and 7 gears, and the change rate of the rotating speed is lower than-500 rpms, the hydraulic torque converter enters an open state.

Preferably, in step 107, the torque converter control process from lockup to lockup includes time compensation and pressure compensation.

Preferably, when the gear is fixed, the smaller the speed change rate is, the larger the pressure compensation value is, and P is_dropThe smaller the value; when the rotating speed change rate is the same, the lower the gear is, the larger the pressure compensation value is, and P_dropThe smaller the value;

when the gear is fixed, the smaller the change rate of the rotating speed is, the larger the time compensation value is, and T_P2The smaller the value; when the change rate of the rotating speed is constant, the lower the gear is, the larger the time compensation value is, and T_P2The smaller the value.

Preferably, in 1 gear, when the rotating speed change rate is between-500 and-180 rpms, the pressure compensation value range is between-1.5 and-0.5 bar, P_dropIn the range [ 0, 1 ] bar;

in gear 2, when the speed change rate is between-500 and-250 rpms, the pressure compensation value range is between-1.5 and-0.5 bar, P_dropIn the range [ 0, 1 ] bar;

in 3 gear, when the rotation speed change rate is between-500 and-400 rpms, the pressure compensation value range is between-1 and-0.5 bar, P_dropIn the range [ 0.5, 1 ] bar;

in 4-gear, when the change rate of the rotating speed is [ - ∞ -500 ] rpms, the pressure compensation value is-0.5 bar, P_dropIs 1 bar.

Preferably, in 1 gear, when the rotating speed change rate is between-500 and-180 rpms, the time compensation value is between-500 and-300 ms, and T_P2Is [ 0,200 ] ms;

in the 2-gear, when the change rate of the rotating speed is between-500 and-250 rpms, the time compensation value is between-500 and-100 ms, and TP2 is 0,400 ms;

in 3 gear, when the change rate of the rotating speed is between-500 and-400 rpms, the time compensation value is between-300 and-100 ms; t is_P2Is [ 200,400 ] ms;

in 4-gear, when the change rate of the rotating speed is [ - ∞ -500 ] rpms, the time compensation value is-100 ms, T_P2Is 400 ms.

By adopting the technical scheme, compared with the prior art, the invention has the following advantages:

1. and the hydraulic torque converter is forcibly opened in advance by monitoring the gear and the braking degree.

2. The hydraulic torque converter is controlled to be opened by adopting pressure compensation and time compensation, so that the safety and the comfort of driving are ensured to the maximum extent on the premise of not extinguishing the engine.

Drawings

FIG. 1 is a flow chart of a torque converter from lockup to lockup in a hard braking condition according to the present invention; FIG. 2 is a timing diagram of the torque converter of the present invention from locked to unlocked.

Detailed Description

In order to more clearly understand the technical features, objects and effects of the present invention, the embodiments of the present invention will be described with reference to the accompanying drawings, and it will be understood by those skilled in the art that the following should not be construed as limiting the scope of the present invention.