Electronically controlled brake device

An electronically controlled brake device for electronically controlling brake pressure according to a manual control input, comprising:

• a manual control input end having manual input means;
• a control input stroke sensor for detecting the displacement of said manual control input end;
• a dynamic pressure source;
• a reservoir;
• a dynamic pressure chamber;
• an electronic control unit for producing pressure control commands on the basis of sensor information including the information from said control input stroke sensor;
• an electronic pressure control valve operable in response to the commands from said electronic control unit to control the communication of said dynamic pressure chamber with said dynamic pressure source and with said reservoir to control the fluid pressure in said dynamic pressure chamber and to supply the output pressure of said electronic pressure control valve to said dynamic pressure chamber as input pressure to said dynamic pressure chamber;
• a dynamic pressure piston adapted to be driven under the input pressure to said dynamic pressure chamber supplied through said pressure control valve;
• a master cylinder operative in response to the movement of said dynamic pressure piston to supply static pressure to at least one brake circuit;
• and
• a push rod coupled with said manual control input end at one end thereof and adapted to be exposed to the pressure in said dynamic pressure chamber with a smaller exposure area than that of said dynamic pressure piston at the other end thereof;
• whereby, while the dynamic pressure line is functioning normally, said push rod is kept apart from said dynamic pressure piston, giving to said manual control input end a reaction force proportional to the pressure in said dynamic pressure chamber and a stroke shorter than that of said dynamic pressure piston, and if the dynamic pressure line should fail, said push rod comes into contact with said dynamic pressure piston, giving to said manual control input end a reaction force and a stroke equal to those of said dynamic pressure piston generated by the static brake circuit.