Four-freedom-degree three-finger operating parallel mechanism

The invention discloses a four-freedom-degree three-finger operating parallel mechanism which comprises a mechanism base, a movable platform, an SP-type linear driving branch and three UPUR-type finger driving branches of a completely same structure, wherein the SP-type linear driving branch and the three UPUR-type finger driving branches are connected with the mechanism base and the movable platform. One end of the SP-type linear driving branch is fixedly connected with the movable platform through a sliding pair, the other end of the SP-type linear driving branch is connected with the mechanism base through a ball pair, the three finger driving branches of the same structure are evenly arranged in a circumferential mode between the mechanism base and the movable platform, one end of a linear driving rod of each finger driving branch is connected with the mechanism base through a universal pair, the other end of the linear driving rod of each finger driving branch is connected with one end of a finger connecting rod through a universal pair, the middles of the finger connecting rods are connected with the movable platform through revolute pairs, and the other ends of the finger connecting rods are free ends. The four-freedom-degree three-finger operating parallel mechanism is simple in structure, large in three-finger pose work space, good in flexibility and large in operating force, and has the wide application prospects in the aspects such as high-end numerical control operator clamping and forging, medical treatment surgeries, outer space and deep sea exploration, military reconnaissance and rescue and dangerous article or pipe dirt removal.