Transmission Solenoid Valve for ZF

The role of the automotive transmission solenoid valve is to control the mechanical valve to complete the switching of the oil circuit and the pressure regulation of the oil circuit flow, which is controlled by the transmission electronic control module TCU. Transmission refers to the transmission, is used to change the speed and torque from the engine mechanism, can fix or shift change the output shaft and input shaft transmission ratio, which is composed of variable speed transmission mechanism and control mechanism.

Transmission types are:

1, according to the change of transmission ratio can be divided into: stepwise transmission, stepless transmission, comprehensive transmission;

2, according to the control mode can be divided into: forced control type transmission, automatic control type transmission, semi-automatic control type.

Simply put, the solenoid valve is like a faucet, with different opening, the flow of hydraulic oil through is different, and the pressure generated is different. The solenoid valve is controlled by the transmission electronic control module TCU, basically the neutral and in gear pressure is a constant value, but the opening of the solenoid valve is adjusted during the shift process to improve the smoothness of the shift.

Different solenoid valves control different clutches or brakes and play a role in different gears. Each gear is controlled by one or more solenoid valves.

The working principle and structure of the solenoid valve generally use two three-way valves, and some use three three-way valves. The transmission solenoid valve uses the reversing function of the two-way three-way solenoid valve to make the oil pressure of the brake pump reciprocate constantly around the pressurization, pressure retention and pressure relief, which can reciprocate thousands of times per second, so that the wheel is in a critical state of sliding and holding, so that the wheel has rich adhesion, so that the car does not lose control when braking.