Pressing device on punching machine

According to the material pressing device on the punching machine, a material pressing cylinder assembly comprises a cover plate and a cylinder barrel, a nitrogen spring and the cylinder barrel are fixed to the cover plate, and the nitrogen spring is located in the cylinder barrel; the nitrogen spring cylinder is characterized in that a gas inlet is formed in the right upper portion of the cylinder barrel, a gas outlet is formed in the left lower portion of the cylinder barrel, a spiral flow guide part is arranged between the outer surface of the nitrogen spring cylinder body and the inner wall of the cylinder barrel, and gas entering the cylinder barrel from the gas inlet flows in a surrounding mode along the outer surface of the nitrogen spring cylinder body and is exhausted from a gas outlet hole. 一种冲孔机上的压料装置，它的压料缸组件包括盖板和缸筒，在盖板上固定有氮气弹簧和缸筒，氮气弹簧位于缸筒的内部；其特征是在缸筒的右上部设有进气口，在缸筒的左下部设有出气口，在氮气弹簧缸体的外表面和缸筒的内壁间设置有螺旋导流件，从进气口进入缸筒的气体沿氮气弹簧缸体的外表面环绕流动由出气孔排出。