Valve system of braking device

A valve system of a braking device comprising:

• a valve that is a solenoid valve and disposed in a connection passage connected to a liquid flow passage via which a master cylinder communicates with a wheel cylinder;
• a valve-opening operation unit for performing an opening operation of the valve by applying a first operating voltage or current to the valve;
• and
• a holding operation unit for performing a holding operation for holding a open state of the valve by applying a holding voltage or current smaller than the operating voltage or current to the valve after the valve-opening operation,
• wherein the master cylinder generates a fluid pressure through an operation applied to a brake pedal;
• the wheel cylinder generates a frictional braking force through the fluid pressure;
• and the holding operation unit applies to the valve a second operating voltage or current that is larger than the holding voltage or current and allows an opening operation of the valve after applying the holding voltage or current to the valve during the holding operation.