Method for electromagnetic valve frequency conversion and current control of automatic transmission

Abstract

The invention discloses a method for electromagnetic valve frequency conversion and current control of an automatic transmission. The method comprises control at a clutch/brake oil-way pressure regulation stage and control at a clutch/brake oil-way pressure maintenance stage, wherein an electromagnetic valve carrier valve control technology is adopted for the clutch/brake oil-way pressure regulation stage and current control is adopted for the pressure maintenance stage, and whole-course frequency conversion control of the electromagnetic valve is realized; the electromagnetic valve carrier valve control technology is adopted for the clutch/brake oil-way pressure regulation stage so that the response speed and the response precision of the electromagnetic valve are improved; the current control is adopted for the clutch/brake oil-way pressure maintenance stage, so that current change, caused by circuit voltage change, is avoided, and self-adaptive control of current is realized; besides, the current control is adopted for the clutch/brake oil-way pressure maintenance stage, so that extra heating or electromagnetic force reduction, caused by current change, of the electromagnetic valve is avoided, and the reliability of the electromagnetic valve during working is improved.

Description

technical field [0001] The invention belongs to the technical field of vehicle transmission, and in particular relates to a frequency conversion and current control method for a solenoid valve of an automatic transmission. Background technique [0002] Modern automatic transmissions use solenoid valves to regulate or maintain pressure in the hydraulic oil circuit for gear shifting or clutch locking and unlocking. However, if the vehicle frequently shifts gears or maintains a certain gear for a long time, the solenoid valve needs to be energized for a long time, which will cause the solenoid valve to heat up, resulting in failure or shortening the service life, increasing the maintenance cost of the vehicle. [0003] In order to solve the above problems, current automatic transmission solenoid valves generally adopt frequency conversion control technology, that is, low-frequency control is used in the clutch / brake oil circuit pressure regulation stage to achieve precise press...

AI Technical Summary

Problems solved by technology

However, due to changes in the vehicle's driving conditions and environment, the battery voltage and circuit voltage will fluctuate. If the high-frequency control method is used in the pressure maintenance stage, the solenoid valve current will change with the fluctuation of the circuit voltage, causing the electromagnetic force to occur. Changes lead to heat, and more seriously, the electromagnetic force decreases due to the decrease of the current, causing the solenoid valve to open or close, and the pressure of the oil circuit leading to the clutch / brake controlled by the solenoid valve drops, resulting in disengagement or clutch / brake The transmitted torque fluctuates, which affects the ride comfort and safety of the vehicle

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