Electric parking brake
Disclosed herein an electric parking brake (EPB) that is controlled by an electrical signal and generates a parking braking force includes a caliper housing including a cylinder and a piston slidably provided in the cylinder; and an actuator installed in the cylinder to press and release the piston; wherein the actuator comprises a linear motor installed in the cylinder and having a moving member that moves linearly according to an electrical signal, and a pressing portion that is press-fitted to the moving member to move together with the moving member and presses selectively the piston.
1. An electric parking brake (EPB) that is controlled by an electrical signal and generates a parking braking force, comprising:
a caliper housing including a cylinder and a piston slidably provided in the cylinder; and
an actuator installed in the cylinder to press and release the piston;
wherein the actuator comprises:
a linear motor installed in the cylinder and having a moving member that reciprocates in a straight line according to an electrical signal, and
a pressing portion that is press-fitted to the moving member to move together with the moving member and presses selectively the piston,
wherein the moving member includes a magnet therein to reciprocate with respect to a stator.
2. The electric parking brake of claim 1 , wherein the linear motor comprises:
a motor housing installed in the cylinder;
the stator disposed in the motor housing and including a coil generating magnetic energy by an applied power.
3. The electric parking brake of claim 2 , wherein the moving member has a bar shape with a predetermined length, wherein opposite ends in a longitudinal direction thereof pass through the motor housing, one end thereof is coupled to the pressing portion, and the other end thereof is provided to pass through a rear wall of the cylinder.
4. The electric parking brake of claim 3 , wherein a guide sleeve configured to support the moving member is provided on the rear wall of the cylinder through which the moving member passes.
5. The electric parking brake of claim 4 , wherein a sealing member is provided between the moving member and the guide sleeve.
6. The electric parking brake of claim 2 , further comprising a fixing bolt passing through a rear side of the cylinder to fix the motor housing.
7. The electric parking brake of claim 1 , wherein a sealing member is provided in a bore in the cylinder to block an inflow of brake oil into the linear motor.
8. The electric parking brake of claim 7 , wherein the sealing member is provided to have a disk shape in which a through hole is formed so that the moving member passes through a center thereof.
9. The electric parking brake of claim 8 , wherein
a fixing groove recessed inwardly is formed in a bore in the cylinder, and
an outer side of the sealing member is fixed to the fixing groove.
10. The electric parking brake of claim 1 , wherein
the cylinder includes a first bore in which the linear motor is installed, and a second bore in which the piston is disposed, and
the first and second bores are formed to be stepped.