Pre-fill system to improve brake feel and method of increasing initial flux using the same

A pre-fill system installed between a master cylinder and a disc brake to increase an initial flux in braking, the pre-fill system comprising:

• a first housing connected with the master cylinder to receive hydraulic brake pressure and provided with a first bore having a smaller-diameter portion and a larger-diameter portion extending from the smaller-diameter portion;
• a second housing provided with a stepped second bore communicating with the first bore to be coupled with the first housing to define a hydraulic pressure chamber, the second housing being connected with the disc brake;
• a piston arranged in the first bore to be movable forward and backward and provided with an oil channel unit which has two different cross-sectional areas corresponding to the smaller-diameter portion and the larger-diameter portion and is penetrated in a longitudinal direction;
• and
• a valve assembly adapted to open and close the oil channel unit of the piston according to the hydraulic brake pressure,
• wherein, when braking is performed, the piston applies pressure to the hydraulic pressure chamber through a portion of the piston having the cross-sectional area corresponding to the larger-diameter portion among the two different cross-sectional areas to supply hydraulic pressure to the disc brake, wherein the oil channel unit includes a high-pressure hydraulic channel formed at a center of the piston, and a return channel spaced apart from the hydraulic channel, the return channel communicating with the hydraulic pressure chamber.