Four-freedom-degree high-speed parallel robot mechanism

The invention discloses a four-freedom-degree high-speed parallel robot mechanism which comprises a fixed frame, a moving platform, a first branched chain, a second branched chain, a third branched chain and a fourth branched chain. The first branched chain, the second branched chain, the third branched chain and the fourth branched chain are arranged between the fixed frame and the moving platform. The first branched chain and the second branched chain each comprise a rotating fork, a close frame bar, two parallel and equilong far frame bars and a rotating shaft, wherein each rotating fork is rotationally connected with the fixed frame, one end of each close frame bar is rotationally connected with the corresponding rotating fork, the other end of each close frame bar is spherically hinged to the corresponding far frame bars, each far frame bar is spherically hinged to the corresponding rotating shaft, and each rotating shaft is rotationally connected with the moving platform. The third branched chain and the fourth branched chain each comprise a close frame bar and two parallel and equilong far frame bars, wherein one end of each close frame bar is rotationally connected with the fixed frame, the other end of each close frame bar is spherically hinged to the corresponding far frame bars, and each far frame bar is spherically hinged to the moving platform. The mechanism is ingenious in design and compact in structure and can adapt to complex grabbing and releasing environments.