Patent ID: 7192099

Claim:
A brake device comprising: a brake cylinder, a reservoir arranged and constructed to accumulate a working liquid discharged from the brake cylinder, a pump arranged and constructed to transfer the working liquid accumulated within the reservoir, a master cylinder arranged and constructed to receive the working liquid discharged from the pump, and a pulsation-reduction device arranged and constructed to reduce pulsation in pressure of the working liquid discharged from the pump before the discharged working fluid communicates with the master cylinder, wherein the pulsation-reduction device comprises: a valve device disposed in a communication channel connecting the downstream side of the pump to the master cylinder, the valve device comprising: a spool movable in response to a difference in pressure between a pump side of the communication channel and a master cylinder side of the communication channel, wherein the movement of the spool functions to open and close at least a part of the communication channel, wherein the pulsation-reduction device further comprises: a buffer chamber defined in the communication channel, and a cylinder disposed within the buffer chamber, wherein the buffer chamber is separated by the cylinder into a first sub-chamber communicating with a discharge side of the pump, and a second sub-chamber communicating with the master cylinder, wherein the first sub-chamber and the second sub-chamber communicate with each other via a communication passage that defines a part of the communication channel, wherein the spool is slidably disposed within the communication passage; wherein an orifice channel is defined between an outer wall of the spool and an inner wall of the communication passage, and wherein the orifice channel is configured so as to permit or prevent communication between the first and second sub-chambers in response to movement of the spool relative to the communication passage.