The punching and cutting process of the pipe is shown. When the press block slides down, the tip of the cutting edge contacts with the tube wall, so that the tube wall is elastically deformed. As the cutting continues, the pressure increases gradually. When the pressure reaches a certain value, the plastic deformation occurs at the contact point between the edge of the blade and the tube wall. At the same time, the edge of the blade starts to press the material.
With the increase of the degree of edge pressing, a high concentration of stress and strain results in the instant brittle fracture of the material, and the edge of the blade enters the lumen. Then, the cutting edge and the die side begin to shear the tube wall until the tube is completely cut off.
In order to reduce the pipe squashed phenomenon, usually die made of a peach, so before punching the pipe in the left and right die strong clip anti deformation produces a certain amount to the (the top of the tube wall, and then by cutting out). Knife punching, star P can reduce the defects the pipe cutter is squashed.
Analysis of the punching process shows that when the tube is cut, the chip is formed inwards. At this point, the die can not afford to shear, pipe flattening phenomenon at this time, and therefore should try to shorten the process, to this end, the cutter curve shape must be done fine and long, but the strength is bad, easy to break.
若做出的刀刃形状宽而短，则切刀强度好，但切屑易向内形成，使压扁现象严重。不利于冲切过程进行。因此，合理确定切刀曲线 形状及尺寸。是冲切法成败的关键。If the blade is wide and short in shape, the cutter is of good strength, but the chip is easy to form inwards, causing the flattening to be severe. Detrimental to the punching process. Therefore, the shape and size of cutter curve should be determined reasonably. Is the key to the success or failure of punching method..