改善织针针坯断面划痕的研究-材料加工工程(金属材料)专业论文.docxVIP

东华大学硕士学位论文 东华大学硕士学位论文 万方数据 万方数据 四个外导柱能消除冲床的定位误差，提高凸凹模间隙的均匀程度，使 冲裁更平稳。四个内导柱能消除模具装配误差，使凸凹模对模更精确、 间隙更均匀；增加弹性反顶装置，在冲裁过程中将板料压紧，限制了 板料的流动和弯曲，提高了刃口附近材料的塑性，使冲件更平整、尺 寸精度和一致性高；采用小间隙圆角刃口结构，消除、延缓裂纹发生， 形成光洁冲裁面，同时也降低对模具的磨损；对凸凹模等工作零件采 用慢走丝线切割加工且“割一修四”，将可能产生的微量变形降低到 最小程度，较好地保证模板的加工表面质量和加工尺寸精度。配合零 件根据其使用要求合理选用加工方式。 2.研究模具材料对织针针坯冲裁断面划痕的影响。对比使用传统 冷冲模材料 Cr12MoV 和高合金高速钢材料 PM30 来制作模具，通过 针坯冲裁面粗糙度、最大划痕深度的测量，以及显微视图来探讨模具 材料和模具表面质量对针坯冲裁面的影响。实验结果表明：选用 PM30 材料冲裁得到的针坯冲裁面划痕较少，断面粗糙度值和最大划痕深度 值相对较低。 3. 研究模具表面粗糙度对织针针坯冲裁断面划痕的影响。采用 抛光加工方法提高模具工作面的质量，重新建立工作面。实验结果表 明：模具经过抛光加工可得到更优异的模具工作面质量，大大改善冲 裁针坯的断面划痕情况。 4.研究不同抛光时间和抛光磨粒对针坯冲裁断面质量的影响。实 验结果表明：粗磨粒有较强去毛刺、棱边倒圆效果，而细磨粒主要提 亮针坯整体的光亮度。将这两种方法进行结合，先用粗磨粒对其进行 II 粗抛 4h，以达到去毛刺、棱边倒圆，再用细磨粒对其进行抛光擦亮 5h，提高移圈针的光泽度，改善外观质量，能得到最优的针坯质量。 关键词：织针；冲裁面划痕；模具材料；模具表面质量；抛光工艺 III STUDY ON IMPROVING SECTION SCRATCH OF FINE BLANKING NEEDLES ABSTRACT Knitting needle is the main part of knitting machine, made of steel wire or steel strip by mechanical processing, used to knit the yarn into a coil and to connect the coil to the knitted fabric. The needle’s quality has important impact on product quality and production efficiency. In the knitting process, the needle’s cutting surface directly contact with the yarn, frequently occur friction, which requires the needle section smooth, no burr, no scratches, high quality of blanking section. Domestic knitting needles have rough cross section, which seriously affects the overall quality, and there is a big gap with well-known foreign companies and manufacturers. That’s why high-grade knitting industry mainly depends on import. Subsequent processing are needed after needles’ fine blanking forming, such as deburring, straightening, machining, heat treatment, but the quality of finished knitting needles’ cross section has an important link with blanking process. After blanking, there are some kinds of long and deep scratches on the cutting section. Through the subsequent polishing process can remove most scratches, but there are a few long and deep s