Root-cause Tree: Burr & Springback on Brass
黄铜冲裁毛刺与回弹根因树
标签：根因树, 毛刺, 回弹, 间隙, 排故
毛刺与回弹联合决策树。毛刺突增按"间隙-刃口-压料"三查：①光亮带比例降到 1/4 以下说明间隙变大，重磨刃口或更换冲针；②毛刺单侧偏大是间隙不均或冲针偏磨，查导柱导套磨损；③压料板压力松会先出碎屑毛刺。回弹超差：H65 黄铜 V 形弯曲回弹角约 2–5°，按"补偿角=回弹角"修模；半硬态料回弹比软态大 30%，可改软态退火料或弯曲位加压校平（保压 0.5 s）。某端子厂用此树把排故时间从 2 h 压缩到 20 min。
A joint decision tree. Burr surge — check clearance, edge, pressure in that order: (1) burnish band below 1/4 of gauge means clearance grew; regrind or replace the punch. (2) Burr heavier on one side — uneven clearance or one-sided punch wear; inspect guide wear. (3) A loose stripper shows up first as crumbly burrs. Springback: H65 brass V-bends open 2–5°, compensate the die by that amount; half-hard springs back 30% more than soft — switch temper or add pressure-flattening with 0.5 s dwell. One terminal shop cut diagnosis from 2 h to 20 min.