A trailer ABS system having a pressure modulator, comprising a relay valve 300 with a control chamber for controlling a main brake pressure supply 1 to an exhaust 3, 306 and delivery ports 301-304 to braking devices (414, fig 3), the relay valve 300 being piloted by a solenoid valve 305, by which where the pressure to the control chamber is switchable. The solenoid 305 has two positions: in the first position, the control chamber is pressurised by the control pressure 4; in the second position, the control chamber is connected to the exhaust 3, 306. A braking ECU actuates the solenoid between the two positions to achieve ABS. The solenoid 305 may be a 2/2 solenoid. A single solenoid 305 may be required. A chock/throttle 307 may control pressure to the control chamber.
Trailer brake control system
2022-10-05
Patent
Elektronische Ressource
Englisch