Parking brake system

A parking brake system that uses a locking device to maintain a parking release condition, comprising:

• a control lever that is rotatably connected to an exterior of a transmission;
• a shift cable, one end of which is rotatably connected to an end of the control lever;
• the locking device that is connected to the other end of the shift cable and selectively maintains the parking release condition;
• and
• a parking device that includes a piston member in a cylinder and that is connected to the end of the control lever and uses hydraulic pressure to move the control lever and the shift cable such that the parking release condition is maintained,
• wherein the locking device includes:
• a locking lever that is connected to the other end of the shift cable and selectively rotated by the shift cable;
• a locking pin that is slidably disposed in the locking lever to ascend and descend relative to the locking lever;
• a locking spring that elastically supports the locking pin;
• and
• a detent that is disposed at an upper end side of the locking pin wherein an engagement position of the locking pin with the detent is varied by rotation of the locking lever according to a stage of a shift speed.