本发明涉及一种塑料型材热切割装置的刀片张紧结构,包括机架、刀架和刀片;刀架通过直线导轨机构可升降地固定在机架上;刀片一端与刀架固连,另一端固定在滑块上,刀架上设有与滑块配合的滑槽,滑槽沿刀片热胀伸长方向设置;还包括滑块驱动装 The utility model relates to a blade tensioning structure of a plastic profile thermal cutting device, which comprises a machine frame, a knife holder and a blade; the knife holder is fixed on the machine frame in a movable way by a linear guide mechanism; one end of the knife blade is fixedly connected with the knife holder, Fixed on the slider, the tool holder is provided with a slider cooperating with the chute, the chute along the expansion direction of thermal expansion blade set; also includes a slider drive