他揉捏她两乳不停呻吟a片,亚洲国产成人精品无码区99,无码jk粉嫩小泬在线观看欧美,黑人上司粗大拔不出来电影

The shell deep drawing stamping part is a cylindrical bottle shaped part that deepens the sheet metal; In deep drawing operations, the diameter of the blank is influenced by the circumference of the shell, which in turn is influenced by the flowability of the stamping material and the inward flow resistance and edge resistance of the peripheral material; When the resistance of the edge material exceeds the limit, the edge will wrinkle and become unstable. To avoid wrinkling, it is necessary for the stamped part material to flow smoothly between the punch and the blank holder. The two main reasons for deep drawing fracture are that the ratio of the diameter of the deep drawing stamping part to the diameter of the blank exceeds the limit value, and when the drawing radius is drawn from a flat blank to a shell and the shell is drawn to a smaller diameter shell, there is a limit value for the inward flow distance of the material, commonly referred to as the drawing coefficient. The ultimate drawing coefficient is influenced by factors such as the material fluidity of the stamping part, the material compression capacity, and the flow resistance caused by compression. Excessive flow resistance causes damage and wrinkling at the edge of the shell, which is the area with the weakest material resistance;