Control method for hydraulic torque converter under working condition of emergency braking

Abstract

The invention discloses a control method for a hydraulic torque converter under the working condition of emergency braking. The control method comprises the steps that when the hydraulic torque converter is in a locking state, a gear signal of a gearbox is monitored, a rotation speed signal is obtained, the rotation speed change rate is calculated, and after the rotation speed change rate reachesa certain value, the hydraulic torque converter is forced to be opened. By monitoring the gear and braking degree, the hydraulic torque converter is forced to be opened in advance, the hydraulic torque converter is controlled to be opened by pressure compensation and time compensation, and under the premise of protecting an engine from stalling, the safety and comfort of driving can be ensured tothe maximum extent.

Description

technical field [0001] The invention belongs to the technical field of hydraulic torque converter control methods, and in particular relates to a hydraulic torque converter control method under sudden braking conditions. Background technique [0002] The working state of the hydraulic torque converter has two working conditions: open and locked. The existing technology mainly realizes opening and locking through the control diagram of the hydraulic torque converter. When it is in the open state, it can increase the torque. To improve power performance, it is a flexible connection at this time, but because it is oil transmission, the efficiency will be low. The open working condition is generally used when the vehicle is started in a low gear (1st gear and 2nd gear) or when the accelerator is accelerating. When it is in the locked state, the internal lock-up clutch enters the locked working condition, and the engine power can be 100% transmitted to the transmission, which has...

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Problems solved by technology

[0002] The working state of the hydraulic torque converter has two working conditions: open and locked. The existing technology mainly realizes opening and locking through the control diagram of the hydraulic torque converter. When it is in the open state, it can increase the torque. To improve the power performance, it is a flexible connection at this time, but because it is oil transmission, the efficiency will be low. The open working condition is generally used when the vehicle starts in low gear (1st and 2nd gear) or accelerates with a large accelerator.

When it is in the locked state, the internal lock-up clutch enters the locked working condition, and the engine power can be 100% transmitted to the transmission, which has high efficiency, but at this time it is a hard connection and cannot play the role of torque increase. The locked working condition is generally used for High gear (3rd gear and above) normal driving, long working conditions and cycle

[0003] In the process of realizing the present invention, the inventor found the following disadvantages in the prior art: when the hydraulic torque converter is in the working condition from locking to opening, if the pressure drops too fast, relative to the entire power system, it will be hard-wired. There is no transition period to the soft connection, and the whole vehicle will have the problem of slowing down the car; if it is still locked in a low gear, the vehicle speed is still or very low, the engine speed will be lowered, and the engine will even be pulled and stalled. In some cases, if the pressure drops too slowly, it will cause untimely unlocking, and there will be a safety hazard of engine flameout

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