A method for diagnosing an electric brake system is disclosed. The method for diagnosing an electric brake system, which includes a reservoir, a master cylinder, a first backup flow path, a second backup flow path, a first cut valve, a second cut, a simulation device, a hydraulic pressure supply device, a first hydraulic flow path, a second hydraulic flow path, a hydraulic control unit, and an electronic control unit configured to control the hydraulic pressure supply device and the valves on the basis of hydraulic pressure information and displacement information of the brake pedal, comprising a first diagnosis mode of: closing the first cut valve and the second cut valve when the pedal effort is not provided to the brake pedal; operating the hydraulic pressure supply device to generate hydraulic pressure at the hydraulic control unit; measuring the hydraulic pressure in the first or second hydraulic circuit; and comparing the measured hydraulic pressure with a first reference pressure to diagnose abnormality of the valves.

An electric brake system is disclosed. The electric brake system comprises an electronic control unit configured to control a hydraulic pressure supply device and valves on the basis of hydraulic pressure information and pedal displacement information and including a circuit board on which a plurality of electronic elements are mounted, and the hydraulic pressure supply device configured to generate hydraulic pressure using a rotational force of a motor that is activated in response to an electrical signal output from the electronic control unit, wherein the circuit board and a housing of the hydraulic pressure supply device contact each other to transfer heat generated at the plurality of electronic elements to the housing of the hydraulic pressure supply device.

A hydraulic braking system for a bicycle may include a hydraulic control device that is configured with multiple timing ports positioned within a stroke of a piston of the hydraulic control device. The multiple timing ports are located at different positions along an operational and/or axial length of a cylinder of the hydraulic control device.

Disclosed herein is a master cylinder for a brake system. The master cylinder for a brake system comprises a cylinder body in which a bore is formed, at least one piston provided to be movable forward and backward in the bore, a hydraulic chamber pressurized by the piston, an oil port connected to a reservoir and configured to supply oil to the hydraulic chamber of the cylinder body, and a sealing member installed in the cylinder body and configured to block a flow of oil between the oil port and the hydraulic chamber according to a movement of the piston, wherein the piston includes a piston groove having an inclined surface in contact with the sealing member and a plurality of piston holes formed along an outer circumferential surface of the piston groove configured to communicate the oil port with the hydraulic chamber.

A primary piston of molded plastic material equipped with a metallic insert and having grooves, mounted in a master cylinder comprising at least a primary piston and a secondary piston mounted in the bore hole of the master cylinder. These pistons can create pressure, respectively, in a primary pressure chamber and in a secondary pressure chamber due to the action of a push rod on the primary piston.

A primary piston of molded plastic material equipped with a metallic insert and having grooves, mounted in a master cylinder comprising at least a primary piston and a secondary piston mounted in the bore hole of the master cylinder. These pistons can create pressure, respectively, in a primary pressure chamber and in a secondary pressure chamber due to the action of a push rod on the primary piston.

A brake fluid reservoir is connected to a master cylinder by a neck which is arranged in an upper chamber of the master cylinder. Holes extend through a surface of a piston, opening to a pressure chamber. The piston extends through a bore hole of the master cylinder. A drill hole extends through an interior wall of the master cylinder, opening into the bore hole, thereby providing communication between the fluid reservoir and the pressure chamber. A floating orifice plate is arranged within the upper chamber, between the neck of the brake fluid reservoir chamber and the drill hole, such that the orifice plate forms a baffle that limits a flow rate of liquid from the brake fluid reservoir chamber to the pressure chamber; and includes supports pressing against a surface of the interior wall of the master cylinder and arranged around the first side of the drill hole.

A brake fluid reservoir is connected to a master cylinder by a neck which is arranged in an upper chamber of the master cylinder. Holes extend through a surface of a piston, opening to a pressure chamber. The piston extends through a bore hole of the master cylinder. A drill hole extends through an interior wall of the master cylinder, opening into the bore hole, thereby providing communication between the fluid reservoir and the pressure chamber. A floating orifice plate is arranged within the upper chamber, between the neck of the brake fluid reservoir chamber and the drill hole, such that the orifice plate forms a baffle that limits a flow rate of liquid from the brake fluid reservoir chamber to the pressure chamber; and includes supports pressing against a surface of the interior wall of the master cylinder and arranged around the first side of the drill hole.

An electric brake device includes a first slave piston which is housed in a cylinder body and generates hydraulic pressure in a first hydraulic chamber by moving forward, a motor which transmits a driving force to the first slave piston, and a restriction pin which is inserted and secured to the cylinder body in a direction perpendicular to an axial direction of the cylinder body and restricts a backward position of the first slave piston when a hydraulic pressure is applied from an outside to the first hydraulic chamber, wherein the restriction pin is inserted and secured to the cylinder mechanism in the direction perpendicular to the axial direction of the cylinder main body. Further, a clearance is formed between an inner peripheral wall of the cylinder body and a first groove portion and second groove portion which are formed on an outer surface of the restriction pin.

An electric brake device includes a first slave piston which is housed in a cylinder body and generates hydraulic pressure in a first hydraulic chamber by moving forward, a motor which transmits a driving force to the first slave piston, and a restriction pin which is inserted and secured to the cylinder body in a direction perpendicular to an axial direction of the cylinder body and restricts a backward position of the first slave piston when a hydraulic pressure is applied from an outside to the first hydraulic chamber, wherein the restriction pin is inserted and secured to the cylinder mechanism in the direction perpendicular to the axial direction of the cylinder main body. Further, a clearance is formed between an inner peripheral wall of the cylinder body and a first groove portion and second groove portion which are formed on an outer surface of the restriction pin.