Constant-volume filling device

The invention relates to a constant volume filling device. Particularly relates to filling in the process of an automatic production line of medicines such as capsules and the like. Comprising a driving shaft, a cover plate, a constant-volume mechanism, a rubber head and a funnel, the driving shaft penetrates through the funnel to be connected with the constant-volume mechanism, the spherical surface of the constant-volume mechanism is in close fit with a ball socket of the rubber head, the cover plate is connected with the funnel, and the rubber head falls on the cover plate; material powder needing to be filled falls into a constant-volume hole of the constant-volume mechanism through the rubber head, the driving shaft rotates to drive the constant-volume mechanism to rotate, in the rotating process of a constant-volume ball in the constant-volume mechanism, the spherical surface gradually blocks a feeding port of the rubber head to stop feeding, meanwhile, along with rotation of the constant-volume mechani