Patent ID: 8801110

Claim:
A vehicle brake device in which a first piston that is operated directly by a drive source and a second piston that is a free piston operated indirectly in response to operation of the first piston are disposed in tandem within a cylinder main body, a first fluid pressure chamber formed between the first piston and the second piston is connected to first wheel cylinders of front-side left and right wheels or rear-side left and right wheels, and a second fluid pressure chamber formed between the second piston and the cylinder main body is connected to second wheel cylinders of left and right wheels on a side different from the first wheel cylinders, wherein the vehicle brake device comprises: a first pump supplying brake fluid of the first fluid pressure chamber to the first wheel cylinders; and a second pump supplying brake fluid of the second fluid pressure chamber to the second wheel cylinders; a first electromagnetic valve controlling the state of communication between a suction side of the first pump and the first fluid pressure chamber; a second electromagnetic valve controlling the state of communication between a discharge side of the first pump and the first fluid pressure chamber; a third electromagnetic valve controlling the state of communication between a suction side of the second pump and the second fluid pressure chamber; and a fourth electromagnetic valve controlling the state of communication between a discharge side of the second pump and the second fluid pressure chamber, wherein the second electromagnetic valve and the fourth electromagnetic valve have a variable degree of opening.