Spinning Defect Tree: Wrinkles, Wall Drift & Buckling
旋压缺陷根因树：起皱、壁厚不均与失稳
标签：根因树, 起皱, 壁厚, 失稳, 废品分析
旋压废品按三问定位：①法兰起皱→旋轮走刀覆盖不足或转速过低（φ300 mm 紫铜坯 ≥600 rpm），同时检查尾顶压力，顶紧不足会先塌边后起皱；②壁厚"一侧薄一侧厚"→旋轮轨迹与芯模间隙不均，或单道次减薄率超 25% 使薄壁失稳，把超薄处退回上一道次补旋；③整体喇叭口失稳→道次间未退火或终道次进给过快（>0.8 mm/r）。某灯具厂按此树给每台车床配"道次卡"后，1.0 mm 黄铜灯罩废品率从 12% 降到 3%。
Three questions sort spinning scrap: (1) flange wrinkles — roller coverage too sparse or speed too low (φ300 mm copper needs ≥600 rpm); check tailstock force too, a loose blank buckles before it wrinkles. (2) Wall thin on one side — roller-to-mandrel gap uneven, or pass reduction over 25% destabilising thin walls; send the thin zone back a pass. (3) Bell-mouth collapse — skipped inter-pass anneals or final feed over 0.8 mm/r. One lighting shop added a pass card per lathe and dropped 1.0 mm brass shade scrap from 12% to 3%.