| 摘要 |
A structure of a drum brake is provided to reduce an initial operation pressure of the drum brake by supplying working fluid to a return spring, which is divided into two sections such that a length of the spring is changed. A structure of a drum brake comprises a drum(21), a lining installed at inner left/right sides of the drum, a return spring(23), a back plate, a first plate(31), a first piston(32), a cylinder(33) installed on the entire surface of the back plate, a second piston(34) and a second plate(35). The return spring is connected to the lining at an upper part and a lower part thereof and is divided in the middle portion thereof. The back plate covers the drum from a rear side of the drum brake and supports the return spring. The first plate is installed at a back surface of the back plate and contains working fluid(41). The first piston is installed on the first plate to be pressed by the working fluid. The second piston is installed on the cylinder while disposing the return spring at a front side of the drum brake, and operates according to an operation of the first piston. The second plate is connected to the return spring and rotates according to a linear movement of the second piston.
|
