CD grain machine

The invention discloses a CD grain machine which comprises a rack, a clamping mechanism, a power device for driving the clamping mechanism to rotate and a cutter shaft mechanism for driving CD grain machining on a workpiece. The clamping mechanism comprises a locating seat used for being fixedly connected to the rack and a pull rod rotationally connected to the locating seat. A clamping barrel and a clamping barrel sleeve used for locking the clamping barrel are arranged on the upper side of the pull rod. The cross section of the outer wall of the clamping barrel is round, and the outer wall of the clamping barrel is gradually increased downwards. The outer wall of the clamping barrel is sleeved with the clamping barrel sleeve, the pull rod is connected to the clamping barrel sleeve, and the clamping barrel sleeve has the motion tendency of clamping the clamping barrel downwards all the time. The cutter shaft mechanism comprises a feeding air cylinder, a locating plate connected to the output end of the feeding air cylinder, a machining cutter driven by the feeding air cylinder, a limiting datum plane and a buffer which is connected to the locating plate and located on one side of the limiting datum plane. When the machining cutter is driven by the feeding air cylinder to move towards the workpiece, the buffer is gradually close to the limiting datum plane and abuts against the limiting datum plane. According to the CD grain machine, the machining quality of the workpiece can be improved.