Patent ID: 8801112
Filing Date: 2014-08-12
Classification: B60T

Abstract:
1. A brake device comprising: a mechanical pressure regulating part including: a high-pressure source which is connected to the high-pressure port and the first pilot pressure input port, and which accumulates fluid pressure of a brake fluid pumped by an electric pump; a low-pressure source which is connected to the low-pressure port and the first pilot pressure input port, and which supplies lower pressure than the high-pressure source; an electrically-operated pilot pressure generating part which includes a pressure boost control valve for controlling flow of the brake fluid between the high-pressure source and the first pilot pressure input port, and a pressure reduction control valve for controlling flow of the brake fluid between the low-pressure source and the first pilot pressure input port, and which outputs desired fluid pressure to the first pilot pressure input port by controlling the flow of the brake fluid with the pressure boost control valve and the pressure reduction control valve; wherein the pressure boost control valve is a control valve of a normally closed type, and the pressure reduction control valve is a control valve of a normally open type; a mechanical pilot pressure generating part which is connected to a second of the pilot pressure input ports, and which generates the pilot fluid pressure corresponding to an operating amount of a brake operating member; wherein the mechanical pilot pressure generating part is connected to the second pilot pressure input port which communicates with the first pilot fluid pressure chamber formed by the first piston driven by the output fluid pressure from the mechanical pilot pressure generating part, wherein the electrically-operated pilot pressure generating part is connected to the first pilot pressure input port which communicates with the second pilot fluid pressure chamber formed by the second piston driven by the output fluid pressure from the electrically-operated pilot pressure generating part, and wherein the first piston driven by the output fluid pressure from the mechanical pilot pressure generating part is also driven by movement of the second piston driven by the output fluid pressure from the electrically-operated pilot pressure generating part.