| 摘要 |
A three-step variable valve lift system is provided to divide a low cam into a low speed section and a mid speed section, and to achieve optimum design of the cam. A three-step variable valve lift system includes a cam shaft(21); a low speed cam(32) and a high speed cam(31) mounted on the cam shaft; a rocker arm(22) arranged at sides of the low and the high speed cam; a high speed switching pad(23) arranged at one side of the rocker arm, and turned into a lost motion state when no hydraulic pressure is formed in an internal channel of the rocker arm; a low speed two-step variable roller(24) arranged at one side of the high speed switching pad, and operated in accordance with the hydraulic state of the internal channel of the rocker arm; a high speed stopper pin(29) and a low speed stopper pin(28) arranged at one side of the high speed switching pad, and operated in accordance with the level of the hydraulic pressure; and a position switching fork(25) for operating the low speed two-step variable roller through the operation of the low speed stopper pin. |
