The invention discloses a top
pier holding device for a numerical-controlled
pipe bending
machine. The top
pier holding device comprises a support frame and a
convolution type clamping structure, wherein the support frame is at least provided with two openings, and the two openings are adjacent; the
convolution type clamping structure is rotatably connected to an inner cavity of the support frameand comprises a pushing
collet, a fixed clamping block, a fixed shaft and a pushing component, wherein a first semicircle groove is formed in the fixed clamping block; a shaft fixing block is fixedlyconnected to the inner wall of the support frame, and the shaft fixing block is symmetrically arranged on two sides of the inner part of the support frame; the end of the fixed shaft is fixed to the shaft fixing block; and the pushing
collet sleeves the fixed shaft, and besides, the pushing
collet performs circumferential rotation around the fixed shaft. According to the top
pier holding device disclosed by the invention, the whole equipment is simple in structure, large in clasping force and small in occupied area; after
pipe bending is completed, all structural members of the top pier holding device are lower than the lower surface of a
pipe; and according to the size of the pipe bending
radius, the whole equipment can adjust the axial position of the pushing collet.