Balanced rotation hole -forming mechanism of counter weight

The utility model relates to a balanced rotation hole -forming mechanism of counter weight, it has driving crank and driven crank in that the frame coparallel is articulated to include, is fixed with the guide arm on driving crank, and power articulate one end is passed through the slider and is connected on the guide arm, and the power articulate other end articulates in the frame, its characterized in that, the one end of driven crank hinge in the frame, the other end of driven crank and the one end of a connecting rod are articulated, are equipped with the bunch planting pole on the other end of a connecting rod, driving crank's one end articulates in the frame, and driving crank's the other end is articulated with the one end of second connecting rod, and the other end of second connecting rod articulates the intermediate position at first connecting rod, driving crank on be fixed with drive?sprocket, be fixed with driven sprocket on the driven crank, driven sprocket passes through the chain and is connec