Brake Hydraulic Sensing Downshift Method and Structure for Automatic Transmission Vehicles

摘要

According to the present invention, since the brake pressure applied to the hydraulic brake decreases due to the weakening of the compressed air or the vacuum when the engine suddenly stops the conventional brake power supply device, an accident due to the weakening of the braking force may occur. A first step of detecting hydraulic pressure of the brake, a second process of applying power to the TCU when the brake hydraulic pressure of the first step is lower than a predetermined level, and a shift control solenoid valve turned on / off by the TCU A brake hydraulic pressure sensing downshift method of an automatic transmission vehicle having a third process of controlling the shift control valve by the SCSV and being forcibly downshifted by the SCSV, and brake oil flowing through the brake oil By the pressure switch 60 for sensing the pressure of the flow path 50 and the signal of the pressure switch 60 TCU 51 for operating an internal shift down circuit, SCSVs 51 and 52 turned on and off by the TCU 51, and SCVs controlled by the SCSVs 51 and 52 to change the vehicle speed ( 54), it detects the oil pressure of the brake and automatically shifts the engine speed of the vehicle when the engine suddenly stalls. A brake hydraulic pressure sensing downshift structure of a vehicle.