DKBA
华为技术有限公司内部技术规范
DKBA0.450.0040 REV C
钣金冲压件质量要求
Specification For Sheet-metal
Punching Part
2012年07月30日发布 20012年09月1日实施
华为技术有限公司 Huawei Technologies Co., Ltd.
版权所有 侵权必究 All rights reserved
密级：秘密
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修订声明Revision declaration
本规范拟制与解释部门：整机工程部基础平台部
本规范的相关系列规范或文件:无 相关国际规范或文件一致性：无 替代或作废的其它规范或文件：无 相关规范或文件的相互关系：无
规范号 主要起草 部门专家 整机工程部： 1、增加了自铆质量要求； 潘建军（00118387） 郭天次（0014571）许志敏（00114402），2、刷新了钣金件公差要求。 肖春秀(00053994) 黄涛（00121968）张实（00118600），钟宏辉（00121959），张润孝（00049797） MQE:陈亮（00068994） SQE:王进（00151357） DKBA0.450.0040 REV B 质量成本管理部：整机工程部: 肖春秀53994 1、将外观表面的定义引用于主要评审部门专家 修订情况 DKBA0.450.0040 REV C 基础平台部： 周伟 00123276,郑玲 00119690 DKBA0.400.0021 李俊周 00123308,魏华 00102167 2、增加了翻边攻丝的质量要求； 杨曦晨 00152131,和永超 57041 MQE：曾松来00125372 TQC：马宝兴39736 CEG：郑连东 00114949 DKBA0.450.0040 REV1.0 质量成本管理部：质量成本管理部： 肖春秀53994 盛辉21628、周伟16271 结构平台开发部：郑玲15593 MQE：陈军17658 TQC：马宝兴39736 新归档
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目 录
1.
技术要求 .............................................................. 6
1.1. 外观及表面状态一般要求 ................................................................................................................................................ 6 1.1.1. 零件的毛刺面朝向要求 ................................................................................................................................................ 6 1.1.2. 冲裁类平板零件圆角要求............................................................................................................................................. 6 1.1.3. 零件上止裂孔、工艺槽要求 ......................................................................................................................................... 7 1.1.4. 弯曲零件未注圆角R要求 .............................................................................................................................................. 7 1.1.5. 翻边攻丝质量要求 ........................................................................................................................................................ 8 1.1.6. 自铆质量要求 ................................................................................................................................................................ 9 1.1.7. 零件表面的外观要求 .................................................................................................................................................. 10 1.2. 钣金冲压件毛刺的要求 .................................................................................................................................................. 10 1.2.1. 毛刺的高度定义 .......................................................................................................................................................... 10 1.2.2. 结构件的毛刺区域分类 .............................................................................................................................................. 10 1.2.3. 钣金冲压件毛刺质量要求........................................................................................................................................... 14 1.2.4. 钣金冲压件的熔渣要求 .............................................................................................................................................. 15 1.2.5. 钣金冲压件的接刀痕的要求 ....................................................................................................................................... 15 1.3. 钣金冲压件公差要求 ...................................................................................................................................................... 15 1.3.1. 公差要求 ...................................................................................................................................................................... 15 1.3.2. 钣金件冲压公差等级代号及数值 ............................................................................................................................... 16 1.3.3. 其它说明 ...................................................................................................................................................................... 20
2. 检验规则 ............................................................. 22
2.1. 检验类别 .......................................................................................................................................................................... 22 2.1.1. 一般检验 ...................................................................................................................................................................... 22 2.1.2. 补充检验 ...................................................................................................................................................................... 22 2.2. 检验原则 .......................................................................................................................................................................... 22 2.3. 检验规定 .......................................................................................................................................................................... 22
图目录
图 1 折弯件毛刺方向示意图.................................................. 6 图 2 平板件的尖角示意图.................................................... 6 图 3 止裂孔直径示意图...................................................... 7 图 4 工艺槽口示意图........................................................ 7
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图 5 翻边攻丝示意图........................................................ 8 图 6 薄板连接用带锥台翻边攻丝孔结构示意图.................................. 8 图 7 自铆连接示意图........................................................ 9 图 8 钣金件毛刺示意图..................................................... 10 图 9 户外机柜类A、B类区域判断示意图....................................... 12 图 10 室内机柜类A、B类区域判断示意图...................................... 13 图 11 插箱类A、B类区域判断示意图.......................................... 13 图 12 拉手条及面板等小五金类A、B类区域判断示意图.......................... 14 图 13 盒式类A、B类区域判断示意图.......................................... 14 图 14 倒角高度示意图...................................................... 15
表目录
表 1 平板件圆角半径r值..................................................... 6 表 2 普通翻边高度H值和螺纹最少反复打入次数................................ 8 表 3 薄板连接用带锥台翻边攻丝孔翻边高度H值和螺纹最少反复打入次数.......... 9 表 4 自铆参数表............................................................ 9 表 5 自铆连接点最小承力表.................................................. 9 表 6 毛刺高度的极限值..................................................... 15 表 7 钣金公差数值表...................................................... 16
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钣金冲压件质量要求
Specification For Sheet-metal Punching Part
范 围Scope:
本规范规定了华为的钣金冲压件（表面处理前）的质量要求、检验规则。
本规范适用于华为所有的钣金冲压件（表面处理前），设计图中有注明的要求以设计图为准，图中未注明的按此规范为准。
简 介Brief introduction：
规定了钣金冲压件(零件级)的质量要求及检验规则。
关键词Key words：
外观、表面状态、工艺槽口、圆角半径、A类区域、B类区域、毛刺、毛刺高度
华为技术文件优先级说明：
华为产品生产执行的技术文件有：华为图纸、华为企业标准规范、通信设备行业标准、中国国家标准、国际标准。这些标准的优先级别从高到低依次为：华为图纸--华为企业标准规范--通信设备行业标准--中国国家标准--国际标准。如果各级文件之间有不一致的地方，应按最高级别的文件执行。
在华为企业标准规范中，产品专用标准优先于通用技术标准。
术语和定义Term&Definition： 缩略语Abbreviations 英文全名 Full spelling A类区域 B类区域 毛刺 毛刺高度 毛刺面 1级表面 Class A Area Class B Area Burr Height Of Burr Surface of Burr Class 1 Surface 中文解释 Chinese explanation 在钣金供应商交货时，产品在正常工作位置手能触膜到的边角区域；以及设计图中特别要求的部位。 不属于A类的区域都为B类区域 指板料冲裁后留在冲裁件断面边缘锋利的凸起， 指板料冲裁后留在冲裁件断面边缘锋利的凸起的高度 指边缘有毛刺的冲裁件平面。对于落料，毛刺面是接触凸模的平面；对于冲孔，毛刺面是接触凹模的平面。 重要外观表面，体现产品外观形象，具有装饰性，可以直接正视到的主要外观表面。主要包括机柜、插框（包括一体化机箱和数通机箱）、无线射频模块、盒式结构、拉手条等的正面和正面上主要零部件的外表面、机柜前门开门后的正视面、高度小于、等于1.8米的机柜顶面（如Hert中机柜顶面）等。 2级表面 Class 2 Surface 主要外表面，半装饰性的经常可见的外观表面。主要包括机柜方孔条正面、机柜外部侧面、机柜后面、插框（包括2019-7-21
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缩略语Abbreviations 英文全名 Full spelling 中文解释 Chinese explanation 一体化机箱和数通机箱）、无线射频模块的外部侧面和后面及防护网等处经常被打开的可视面等。小五金件、机柜机箱附件等均定义为2级表面。 3级表面 Class 3 Surface 次要外表面和内表面，不是以装饰为目的，表面质量要求不高的结构表面。主要包括机柜、插框（包括一体化机箱和数通机箱）、无线射频模块、盒式结构、拉手条等的内表面和底面、高度大于1.8米的机柜顶面以及安装支架、绑线架、内部框架、内部焊件的所有表面等。除1、2级表面外的表面均为3级表面。
1. 技术要求
1.1. 外观及表面状态一般要求
1.1.1. 零件的毛刺面朝向要求
毛刺面朝向零件里面，如图1：
图 1 折弯件毛刺方向示意图
特殊情况：按编码级分析零件之间的装配关系，零件的毛刺面应在里面或非功能面；如“L”型的零件为滑道，则毛刺面应在零件的外面，与上图相反。
1.1.2. 冲裁类平板零件圆角要求
图样上未注明的外形和内缘小于或等于90°的尖角处应制成圆角（见错误！未找到引用源。），其圆角半径r按0规定。
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图 2 平板件的尖角示意图 表 1 平板件圆角半径r值
材料厚度 t 圆角半径r≤ ≤0.3 0.2 >0.3~0.5 0.3 >0.5~1 0.5 >1~2 1 >2~3 1.5 >3 0.5t 1.1.3. 零件上止裂孔、工艺槽要求
当设计文件或图样上注明允许开止裂孔或工艺槽口时，其止裂孔直径和工艺槽口尺寸，按下列要求选择：
1、止裂孔直径d（见图3）不大于2t；
图 3 止裂孔直径示意图
2、工艺槽口尺寸L和b（见04）；
当t＞0.5mm时，1mm＜b≤1.5 t （如1.5t<1，则b=1）； 当t≤0.5mm时，b=1mm。 L≥t+r+0.5b
图 4 工艺槽口示意图
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1.1.4. 弯曲零件未注圆角R要求
当图样上未注明弯曲半径时，允许按内弯曲半径R不大于t（t为材料厚）且最小值为0.2。
1.1.5. 翻边攻丝质量要求
1、普通翻边高度H值和螺纹寿命满足以下要求：
图 5 翻边攻丝示意图
表 2 普通翻边高度H值和螺纹最少反复打入次数
螺纹规格 板厚T 0.8 M3 1.0 1.2 1.5 1.0 M4 1.2 1.5 M5
2、 薄板连接用的带锥台翻边攻丝
该翻边攻丝孔用于薄板连接的场景，实现M3国标沉头螺钉在0.8、1.0mm板材上不凸出板面,使翻边高度H值和螺纹寿命满足以下要求
1.2 1.5 翻边高度H （公差+0.3～0） 1.8 2 2.2 2.4 2.4 2.6 3 2.4 2.7 0.3 内圆角R 最大值 最少反复打入次数 12 30 30 30 30 30 30 30 30 2019-7-21
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图 6 薄板连接用带锥台翻边攻丝孔结构示意图
表 3 薄板连接用带锥台翻边攻丝孔翻边高度H值和螺纹最少反复打入次数
螺纹 规格 <0.8 0.8 M3 钢 1.0 ≥1.2
3、 翻边后孔边不允许有裂纹、口部不齐等缺陷。不需采用带锥台翻边攻丝，即可实现沉头螺钉无凸出
Φ2.5 Φ2.5 材料 板厚T 翻边后底孔内径D1(参考) 沉头孔大径D3 最少反复 （公差+0.2～0） (公差±0.1) 打入次数 不允许 M3 翻边攻丝 2.5 2.5 Φ4.5 Φ4.5 12 30 翻边高度H 不需采用带锥台翻边攻丝，即可实现沉头螺钉无凸出 1.1.6. 自铆质量要求
1、自铆工艺参数参照以下表和图：
表 4 自铆参数表
序号 1 2 3 4
被铆板厚T2 0.6 0.8 1 1.2 翻边孔高度h 1.1 1.2 1.4 1.6 2019-7-21
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图 7 自铆连接示意图
2、铆合孔内不允许有铁屑存在，自铆处不允许出现铆偏（肉眼可视），裂纹数不超过3条。
3、板厚T2≥0.8mm时，铆合后表面不允许凸起；被铆板厚T2＜0.8mm时，被铆板不沉孔，允许表面凸起，凸起高度不超过T1。
4、铆合后两板之间能承受拉力符合下表要求。
表 5 自铆连接点最小承力表
T1+T2 拉力
0.8+0.8及以下 0.8+1.0 ≥250N ≥350N 1.0+1.0 1.0+1.2及以上 ≥450N ≥600N 1.1.7. 零件表面的外观要求
按相应产品（机箱、机柜、拉手条等）质量要求。
1.2. 钣金冲压件毛刺的要求
1.2.1. 毛刺的高度定义
毛刺高度是指冲裁后冲件断面边缘锋利的凸起的高度（h），详见0。
图 8 钣金件毛刺示意图
1.2.2. 结构件的毛刺区域分类
根据毛刺的要求将结构件的边角分为A类区域和B类区域：
A类区域：在钣金供应商交货时，产品在正常工作位置手能触膜到的边角区域；以及设计图中特别要求的部位，包括但不限于以下特殊位置：
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需要过线缆的孔或槽； 连接器的安装孔； 有相对滑动的边角。
B类区域：不属于A类的区域都为B类区域。
结构件A类区域和B类区域的判断原则举例说明如下，如03：
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图 9 户外机柜类A、B类区域判断示意图
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图 10 室内机柜类A、B类区域判断示意图
图 11 插箱类A、B类区域判断示意图
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图 12 拉手条及面板等小五金类A、B类区域判断示意图
图 13 盒式类A、B类区域判断示意图
1.2.3. 钣金冲压件毛刺质量要求
A类区域：
A类区域须将毛刺去除干净，用棉纱手套去检验，如有棉纤维残留在冲压件上则认为不合格。 B类区域：
B类区域的毛刺高度需在0的极限值内，供应商可根据0中的极限值制订不同的标准样板，用标准样本比对或在显微镜下量测毛刺高度是否符合要求。
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表 6 毛刺高度的极限值
材料抗拉强度（Mpa） ＞100～250 ＞250～400 ＞400～630 ＞0.4 ～0.7 0.12 0.08 0.05 ＞0.7 ～1.0 0.17 0.13 0.07 板材厚度 ＞1.0 ～1.6 0.25 0.18 0.11 ＞1.6 ～2.5 0.37 0.26 0.16 ＞2.5 ～4.0 0.54 0.37 0.3
去除毛刺后的倒角要求：
去除毛刺后的状态为斜角或圆角，斜角和圆角需满足以下要求，如图14所示：
图 14 倒角高度示意图
1.2.4. 钣金冲压件的熔渣要求
对于通过熔化方式（如laser切割、等离子切割等）获得零件外形及内孔而产生的熔渣必须去除干净。
1.2.5. 钣金冲压件的接刀痕的要求
冲压过程中产生的接刀痕可接受，凸起高度不超过板厚的15%。
1.3. 钣金冲压件公差要求
1.3.1. 公差要求
1、图纸尺寸注明了公差值的按图纸公差要求
2、未注尺寸公差一般在二维图技术要求作了如下说明：“未注尺寸公差参照DKBA4031钣金工艺设计规范中钣金件公差设计f级或m级精度要求”， f级或m级公差值见表7：
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1.3.2. 钣金件冲压公差等级代号及数值
钣金冲压件公差等级分为两级，即f级和m级，f级的要求要高于m级。
表 7 钣金公差数值表
特征分类 尺寸分类 特征示意图 f级(精密精度) ≤63 ±0.10 63~160 ±0.15 160~400 ±0.20 400~1000 - >1000 - ≤63 ±0.15 63~160 ±0.20 m级(中等精度) 160~400 ±0.30 400~1000 - >1000 - 圆孔直径 孔间距 孔边距 直边距 ±0.10 ±0.15 ±0.20 ±0.25 ±0.30 ±0.15 ±0.20 ±0.30 ±0.40 ±0.50 冲裁特征 ±0.10 ±0.15 ±0.20 ±0.25 ±0.30 ±0.15 ±0.20 ±0.30 ±0.40 ±0.50 ±0.10 ±0.15 ±0.20 ±0.25 ±0.30 ±0.15 ±0.20 ±0.30 ±0.40 ±0.50 冲裁角度 ① ±0°30' ±0°30' ±0°30' - - ±1.0° ±0°30' ±0°30' - -
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m级(中等精度) 2019-7-21
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密级：秘密
分类 DKBA
≤63 孔到折弯边距离 (1次折弯) 直边到折弯边 距离 (1次折弯) 孔间距 (2次折弯) 折弯边到折弯边 ±0.20 ② ±0.15 ±0.15 63~160 160~400 400~1000 >1000 ≤63 63~160 160~400 400~1000 >1000 ±0.20 ±0.20 ±0.25 ±0.30 ±0.20 ±0.30 ±0.50 ±0.50 ±0.50 ±0.20 ±0.20 ±0.25 ±0.30 ±0.20 ±0.30 ±0.50 ±0.50 ±0.50 ±0.25 ② ±0.25 ② ±0.30 ② ±0.40 ② ±0.25 ±0.30 ±0.50 ±0.50 ±0.75 成型特征 距离 (2次折弯) 直边到折弯边 距离 (3次折弯) 折弯边到折弯边距离 (4次折弯) 孔间距 ±0.15 ±0.20 ±0.20 ±0.25 ±0.30 ±0.25 ±0.30 ±0.50 ±0.50 ±0.75 ±0.20 ±0.25 ±0.25 ±0.30 ±0.40 ±0.30 ±0.40 ±0.50 ±0.75 ±1.00 ±0.25 ±0.30 ±0.30 ±0.40 ±0.50 ±0.30 ±0.40 ±0.50 ±0.75 ±1.00 ±0.20 ±0.25 ±0.25 ±0.30 ±0.40 ±0.30 ±0.40 ±0.50 ±0.75 ±1.00 (4次折弯) ② ② ② ② ② 特征尺寸分类 特征示意图 f级(精密精度) 第17页, 共45页 Page 17 , Total 45
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分类 直边到直边距离 (4次折弯) 局部成型 ±0.20 ±0.25 ±0.25 ±0.30 ±0.40 ±0.30 ±0.40 ±0.50 ±0.75 ±1.00 ≤63 63~160 160~400 400~1000 >1000 ≤63 63~160 160~400 400~1000 >1000 DKBA
≤10 10~25 25~63 - - ≤10 10~25 25~63 - - 形状尺寸 ±0.15 ±0.20 ±0.30 - - ±0.20 ±0.30 ±0.50 - - 局部成型 位置尺寸 成型特征 压死边长度 压死边厚度 (无间隙) 压死边厚度 (有间隙) 折弯角度 ① ±0.5° ±0.5° ±0.5° ±0.5° ±0.5° ±1.0° ±1.0° ±1.0° ±1.0° ±1.0° ±0.20 - - - - ±0.30 - - - - 0.2 0 - - - - 0.3 0 - - - - ±0.15 - - - - ±0.30 - - - - ±0.15 ±0.20 ±0.20 ±0.25 ±0.30 ±0.20 ±0.30 ±0.50 ±0.75 ±1.00
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分类 ≤63 63~160 160~400 400~1000 >1000 ≤63 63~160 160~400 400~1000 >1000 DKBA
喷涂保护尺寸 丝印尺寸 其它特征 平面度③ (平面内少量冲裁特征) 平面度③ (平面内有成形、焊缝或密孔等特征) ±1.0 ±1.5 ±1.5 ±1.5 ±2.0 ±1.0 ±1.5 ±1.5 ±1.5 ±2.0 ±0.5 ±0.5 ±0.5 ±0.5 - ±0.5 ±0.5 ±0.5 ±0.5 - 0.3 0.5 0.8 1.5 3 0.5 0.8 1.5 3 5 0.5 0.8 1.5 3 5 0.8 1.5 3 5 7 说明：
上表适用于厚度不大于1.5mm板材，大于1.5mm厚度的板材其公差可酌情相应增加30%左右； 上表适用于冷轧板、镀锌板等常用板材，弹簧板等板材其公差可酌情相应增加； 冲密孔（通风孔）尺寸公差可参照相应冲裁尺寸公差放大；
压印、压字、加强筋、线桥、凸台、敲落孔、百叶窗等特征公差均可参照局部成形公差值； 压铆螺母/螺柱/螺钉等位置尺寸公差值在其底孔的位置尺寸公差值基础上加±0.05；
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注示为①的冲裁角度、折弯角度的尺寸分段分别指相应特征冲裁短边尺寸、折弯短边尺寸数值分段； 注示为②的公差数值根据工序调整（先折弯后冲孔）可按冲裁孔间距标注公差； 注示为③的平面度尺寸分段指平面内最大对角线长度尺寸分段； 直线度公差值可参照上表中的平面度公差值执行；
对于多于4折的折弯特征，其累积公差按每折加±0.05的精度来处理；
对于多于4折的折弯特征，可以提高其中某一折的尺寸精度，提高的精度值可参照1次折弯精度； 对于上表中未列出的特征，其尺寸公差可参照相似/相近的特征公差来处理；
1.3.3. 其它说明
钣金件尺寸及公差要求是指钣金件成品尺寸及公差，即表面处理（钝化、氧化、电镀、喷涂等）后的尺寸及公差；
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2. 检验规则
2.1. 检验类别
2.1.1. 一般检验
一般检验是指根据设计图样和工艺文件的规定，对钣金冲压件进行的外观检验、尺寸及公差配合检验及常规性能检验。
外观检验是依靠手摸、目测、光照反射、光照投影等方法对钣金冲压件的外观进行检验； 尺寸及公差配合检验是采用工具、夹具、量具，以检验钣金冲压件的尺寸、形状、位置公差； 一般检验可按工艺文件要求或采用标准样件作为对照判定的依据。
2.1.2. 补充检验
补充检验是指一般检验以外的检验。它包括硬度检验、磁性检验、弹性检验、渗透检验、无损探伤检验等。
2.2. 检验原则
钣金冲压件必须进行首件检验、巡回检验和验收检验； 钣金冲压件原则上只进行一般检验；
当设计图样或其它技术文件有具体要求时，应进行补充检验；
批量生产的钣金冲压件，按需要可进行抽检或全检，抽检的方法一般按GB 2828和GB 2829的规 进行；全检一般仅检验主要部分（包括特定的外观要求）。
2.3. 检验规定
冲裁、剪切零件的外形按最大尺寸处进行测量；内孔按最小尺寸处进行测量； 止裂孔直径及工艺槽口尺寸，只在展开料时检查，零件成形后不作检查；
加工后易变形，而在装配时能重新恢复所需几何形状的零件，其尺寸和形状误差，可在装配状态下测量，在自由状态下允许超出极限尺寸。
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1.
Contents
1. TECHNICAL REQUIREMENTS ............................................... 29
1.1. GENERAL REQUIREMENTS FOR APPEARANCE AND SURFACE ....................................................................................... 29 1.1.1. The burr surface is required to be inside the parts, as shown in Figure 1: ..................................... 29
1.1.2.
Blanked and sheared panel parts’ taper angles with outer shapes and inner edges smaller than or
equal to 90° which are not noted on the drawing should be made as fillets (as shown in Figure 2) with a radius (r) specified as Table 1. ................................................................................................................................................ 29
1.1.3. 1.1.4. 1.1.5. 1.1.6. 1.1.7.
If allowable as marked in design documents or drawings, stop holes or technical rabbets can be Parts formed by curving without a curving radius noted on the drawing can be made with an Requirements for flanging-hole with thread： ................................................................................ 30 Requirements for Riveting Quality .................................................................................................. 32 Exterior Requirements of parts ....................................................................................................... 33
open according to the following hole diameter and rabbet size. ............................................................................. 30 internally curving radius R no larger than t (thickness of materials) and no smaller than 0.2. ............................. 30
1.2. REQUIREMENTS FOR THE BURR OF SHEET-METAL PUNCHING PARTS ........................................................................ 33 1.2.1. Definition of Burr Height： ............................................................................................................ 33
1.2.2. 1.2.3. 1.2.4. 1.2.5.
Classifications of burr areas of structural parts ............................................................................. 34 Requirements for the burr quality of sheet-metal punching parts ................................................... 37 Requirements for the Slag of Sheet-Metal Punching Parts ............................................................. 38 Requirements for Tool Withdrawal Marks on Sheet-Metal Punching Parts ................................... 38
1.3. TOLERANCE REQUIREMENTS OF SHEET-METAL PUNCHING PARTS ............................................................................. 39
1.3.1. Statement ......................................................................................................................................... 39 1、 TOLERANCES IN DRAWINGS, IF SPECIFIED, SHALL ALWAYS PREVAIL. ............................................................................... 39
1.3.2. Tolerance Levels and Values ........................................................................................................... 39
Tolerance levels are classified into f and m. f allows lower tolerances than m. ............................................. 39 1.3.3.
Remarks ........................................................................................................................................... 44
2. INSPECTION RULE ...................................................... 45
2.1. INSPECTION CATEGORY .................................................................................................................................................... 45 2.1.1. General Inspection .......................................................................................................................... 45
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2.1.2. Supplementary Inspection ............................................................................................................... 45
2.2. INSPECTION RULES ........................................................................................................................................................... 45 2.3. INSPECTION PROVISIONS .................................................................................................................................................. 45
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2. Figures
Figure 1 Burr of bends ..................................................... 29 Figure 2 Taper angles of panel parts .......................................... 29 Figure 3 Diameter of stop holes .............................................. 30 Figure 4 Technical rabbet................................................... 30 Figure 5 Schematic diagram for flanging-hole with thread ......................... 31 Figure 6 Schematic diagram for flanging-hole with thread for thin sheet connected ..... 32 Figure 7 Riveting procedure................................................. 33 Figure 8 Burr height of sheet-metal structural parts .............................. 33 Figure 9 Identification of Class A and Class B Areas for outdoor cabinets ............ 35 Figure 10 Identification of Class A and Class B Areas for indoor cabinet ............. 36 Figure 11 Identification of Class A and Class B Areas for Subracks ................. 36 Figure 12 Handle bars and panel hardware for Class A and B ...................... 37 Figure 13 Identification of Class A and Class B Areas of Boxes .................... 37 Figure 14 Height of chamfer ................................................ 38
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3. Tables
Table 1 Radius (r) of taper angle ............................................. 29 Table 2 The data of height(H) and Min removable times ........................ 31 Table 3 The data of height(H) and Min removable times for flanging-hole with thread
for thin sheet connected .................................................. 32 Table 4 Riveting parameters ............................................... 32 Table 5 Minimum pulling force borne by riveted points ........................... 33 Table 6 Ultimate value of burr height (Unit: mm) ................................ 38 Table 7 Tolerance levels and values ............................................ 39
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Specifications for Sheet-metal Punching Parts
Scope
This specification covers the general quality requirements and inspection rules for Huawei sheet-metal punching parts (before surface treatment).
This specification applies to Huawei’s all sheet-metal punching parts (before surface treatment). Reference is given to the design drawings with noted requirement and to this specification if not noted in the design drawing.
Brief Introduction
This specification provides the general quality requirements and inspection rules for sheet-metal punching parts.
Keywords
Appearance, surface status, technical rabbet, fillet radius, class A area, class B area, burr, and burr height.
Revision Declaration
Statement on the Priority of Huawei Technical Documents
Huawei products are manufactured based on the following documents which are listed in order of priority: Huawei drawings, Huawei enterprise technical standards,
telecommunications industry standards, China national standards, and international standards. Shall there be discrepancy between these documents, the document of the highest priority takes precedence.
Among Huawei enterprise technical standards, specific product standards have higher priorities than general standards.
Term & Definition
Full Spelling Class A Area Chinese Explanation Corner areas touchable by hands in the normal working position of products when delivered by sheet-metal suppliers; and areas specially required in design drawings. Areas except for Class A Area Burr on the cross section of finished products when blanking sheet metal Burr height on the cross section of finished products when blanking sheet metal Class B Area Burr Height Of Burr 2019-7-21
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Full Spelling Chinese Explanation Level 1 Surface Critical surface represents the product appearance. Through this kind of decorative surface, you can directly see the major product appearance, including the outer surface of the front and of the main parts installed on the front of the cabinet, subrack (involving the integrated chassis and data communications chassis), radio frequency module, box, handle bar, and the surface that you can directly see after opening the front door of the cabinet. Level 2 Surface Major outer surface is half-decorative and is commonly seen, including the front of the mount bar on the cabinet, sides outside the cabinet, rear of the cabinet, sides outside and at rear of the subrack (involving the integrated chassis and data communications chassis) and radio frequency module, and topside of the cabinet that is lower than 1.8 m. Surfaces of the ironware and accessories of the cabinet and chassis are all defined as level 2 surfaces. Level 3 Surface Minor outer surface and inner surface. These surfaces are not decoration-oriented and not demanding on the surface quality, including the inner surface and underside of the cabinet, subrack (involving the integrated chassis and data communications chassis), radio frequency module, box, and handle bar, topside of the cabinet that is higher than 1.8m, and all surfaces of the installing support, bundling rack, inner frame, and inner solder. Surfaces that not belong to level 1 and level 2 surfaces are level 3 surfaces. 华为机密，未经许可不得扩散 Huawei Confidential 第28页, 共45页 Page 28 , Total 45
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1. Technical Requirements
1.1. General Requirements for Appearance and Surface
1.1.1. The burr surface is required to be inside the parts, as shown in 错误！未找到引用源。:
Figure 1 Burr of bends
Exceptions: the burr surface is the inner surface or non-functional surface of parts if the assembling relationship between parts is analyzed based on the coding level; the burr surface is the outer surface of parts if L-shaped parts are slideways, and opposite to the above diagram.
1.1.2. Blanked and sheared panel parts’ taper angles with outer shapes and inner edges smaller than or equal to
90° which are not noted on the drawing should be made as fillets (as shown in 0) with a radius (r) specified as Table 1.
Taper angleTaper angle
Figure 2 Taper angles of panel parts
Table 1 Radius (r) of taper angle
Thickness (t) 2019-7-21
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of materials Radius (r) of 0.2 0.3 0.5 1 1.5 0.5t taper angle ≤ 1.1.3. If allowable as marked in design documents or drawings, stop holes or technical rabbets can be open according to the following hole diameter and rabbet size.
1、 d, diameter of stop holes (as shown in 0), should be smaller than or equal to 2 t;
Figure 3 Diameter of stop holes
2、 L and b, sizes of technical rabbets (as shown in 0); When t > 0.5 mm, 1 mm < b ≤1.5 t (if 1.5 t < 1, b = 1) When t ≤ 0.5 mm, b = 1 mm. L ≥ t + r+0.5b
Figure 4 Technical rabbet
1.1.4. Parts formed by curving without a curving radius noted on the drawing can be made with an internally
curving radius R no larger than t (thickness of materials) and no smaller than 0.2.
1.1.5. Requirements for flanging-hole with thread：
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1、 Requirements for height(H) and Min removable times of flanging (as shown in 05)
Figure 5 Schematic diagram for flanging-hole with thread Table 2 The data of height(H) and Min removable times
High of Plate Inner diameter of flanging-hole(H) thickness(T) flanging-hole(D1) (Tolerance 0～+0.3) 0.8 1.0 M3 1.2 1.5 1.0 M4 1.2 1.5 1.2 M5 1.5
2、 Flanging-hole with thread for thin sheet connected
The flanging-hole is used in thin sheet connected, to achieve that standard countersunk head screw M3
could be sunk into the plate surface with thickness 0.8mm or 1.0 mm. Requirements for height(H) and Min removable times of flanging (as shown in 06).
Φ4.2 2.7 30 Φ3.3 Φ2.5 2.2 2.4 2.4 2.6 3 2.4 0.3 30 30 30 30 30 30 1.8 2 Min removable times (Time) 12 30 Thread Max. R 2019-7-21
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Figure 6 Schematic diagram for flanging-hole with thread for thin sheet connected
Table 3 The data of height(H) and Min removable times for flanging-hole with thread for thin sheet
connected Thread Material Inner diameter Outer High of of flanging-hole diameter of Min D1(Reference) flanging-hole(H) flanging-hole removable Plate D3 times thickness(T) (Tolerance 0～(Tolerance±(Time) +0.2) 0.1) M3 Steel <0.8 Forbid to form flanging-hole with thread of M3 0.8 1.0 ≥1.2
3、 The crazing and cracking of material is not allowed after flanging
1.1.6. Requirements for Riveting Quality
1、 0 lists some key riveting parameters.
Table 4 Riveting parameters
No. 1 2 3 4 Thickness of the Riveted Sheet (T2) 0.6 mm 0.8 mm 1 mm 1.2 mm Height of the Flanged Hole (h) 1.1 mm 1.2 mm 1.4 mm 1.6 mm Φ2.5 Φ2.5 2.5 2.5 Φ4.5 Φ4.5 12 30 Countersunk head screw M3 could be sunk into the plate surface, no need to use flanging-hole with thread. 2019-7-21
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Figure 7 Riveting procedure
2、 No iron scrap shall be found in riveting holes, and no visible deviation shall be found in riveting positions, and the number of cracks is no more than three. 3、 If the thickness of a metal sheet is greater than or equal to 0.8 mm, no bulge shall be found in the riveted surface. If a metal sheet is thinner than 0.8 mm, no dimple shall be found in the riveted surface, but embossments are allowed. 4、 After two sheets are riveted together, they must withstand the pulling force specified in 0.
Table 5 Minimum pulling force borne by riveted points
T1+T2 Pulling Force 0.8+0.8 or less ≥ 250 N 0.8+1.0 ≥ 350 N 1.0+1.0 ≥ 450 N 1.0+1.2 or greater ≥ 600 N 1.1.7. Exterior Requirements of parts The exterior requirements for metal sheet punching parts vary according to the products that the punching parts apply to, such as shelves, cabinets, and ejector levers.
1.2. Requirements for the Burr of Sheet-Metal Punching Parts
1.2.1. Definition of Burr Height：
Burr height is that which is left on the cross section of finished products for punching when blanking sheet metals, as shown in 0.
Figure 8 Burr height of sheet-metal structural parts
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1.2.2. Classifications of burr areas of structural parts
The Class A Area and Class B Area for the corners of structural parts according to burr requirements: Class A Area: touchable corner areas on the normal working position of products when delivered by sheet-metal suppliers and areas specially required in the design drawing, including but not limited to: 1、 Holes or slots for laying cables; 2、 Installation holes of connectors; 3、 Relatively sliding corners.
Class B Area: areas other than those in the Class A Area.
Identification examples of Class A Area and Class B Area of structural parts are as shown in 09, 010, 011, 012, and 013:
Corners visible when opening the door: Class A AreaFolded innersheet invisible All corners of cabling racks: when opening the door: Class A AreaClass B AreaTouchable corners: Class A AreaInstallation area of connectors: Class A Area
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Exposed corners: Class A Area
1. Unexposed corners after assembly: Class B Area2. Exposed corners after assembly: Class A Area, including but not limited to 3-13.3. Exposed corners of dismountable back door: Class A Area4. Corners of non- dismountable back door: Class B Area5. Exposed corners of square hole strips: Class A Area13. Corners of frequently operated parts: Class A Area (e.g. lever)12. Corners of binding racks: Class A Area11. All exposed corners of the front door: Class A Area10. Panel corners: Class A Area (e.g. transmission panel)6. Corners of slideway: Class A Area9. Four edges of accumulator cabinet: Class A Area; other inside corners: Class B Area8. Corners of dismountable parts: Class A Area (e.g. power protection cover and accumulator cabinet cover)7. All GPS cover boards and through holes: Class A Area
Figure 9 Identification of Class A and Class B Areas for outdoor cabinets
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1. Unexposed corners after assembly: Class B Area2. Exposed corners after assembly: Class A Area, including but not limited to 3-13.3. Exposed corners of dismountable back doors: Class A Area4. Corners of non- dismountable back doors: Class B Area DKBA
5. Exposed corners of square hole strips: Class A Area6. Corners of binding racks: Class A Area9. Exposed corners of front doors: Class A Area7. Corners around door frames: Class A Area8. Exposed corners of upper and lower enclosure frames: Class A Area
Figure 10 Identification of Class A and Class B Areas for indoor cabinet
1. Exposed corners of side plates: Class A Area8. Corners of reinforced ribs: Class B Area2. All corners of suspension loops: Class A Area7. Corners of backplate installation plates: Class A Area3. All corners of occulting bars: Class A Area4. Frontal corners of upper and 6. All corners of cabling racks: lower slideways: Class A AreaClass A Area5. Inside corners: Class B Area
Figure 11 Identification of Class A and Class B Areas for Subracks
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All corners of handle bars and panel hardware: Class A Area
Figure 12 Handle bars and panel hardware for Class A and B
1. All exposed corners: Class A Area 2. All exposed corners after opening the cover: Class A Area
Figure 13 Identification of Class A and Class B Areas of Boxes
1.2.3. Requirements for the burr quality of sheet-metal punching parts
Class A Area:
In Class A Area, burrs should be removed and cotton gloves are used for inspection. If there are any fibers remaining on the punching part, it will not be qualified. Class B Area:
Burr height in Class B Areas should be the ultimate value in 0. Suppliers can make various standard samples for comparison according to the ultimate value in 0, or check burr heights with a microscope.
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Table 6 Ultimate value of burr height (Unit: mm)
Tensile strength of materials （Mpa） ＞100～250 ＞250～400 ＞400～630 Material thickness of blanking parts ＞0.4 ～0.7 0.12 0.08 0.05 ＞0.7 ～1.0 0.17 0.13 0.07 ＞1.0 ～1.6 0.25 0.18 0.11 ＞1.6 ～2.5 0.37 0.26 0.16 ＞2.5 ～4.0 0.54 0.37 0.3
Requirements for chamfer after burr removal
Bevels and fillets after burr removal should meet the requirements as shown in 0:
Figure 14 Height of chamfer
1.2.4. Requirements for the Slag of Sheet-Metal Punching Parts
Slag in the process of obtaining parts’ shape and inner holes by melting (e.g. laser or plasma cut) should be removed.
1.2.5. Requirements for Tool Withdrawal Marks on Sheet-Metal Punching Parts
The tool withdrawal mark brought during the punching process is acceptable, but the its height is under
15% of sheet thickness.
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1.3. Tolerance Requirements of Sheet-metal Punching Parts
1.3.1. Statement
1、 Tolerances in drawings, if specified, shall always prevail.
2、 If tolerances are not provided in two-dimensional drawings, add a note specifying \
requirements specified in the DKBA4031 General Specification for Sheet-Metal Punching Parts.\ lists the f and m tolerance levels and values.
1.3.2. Tolerance Levels and Values
Tolerance levels are classified into f and m. f allows lower tolerances than m.
Table 7 Tolerance levels and values
Characteristic Diameter, Distance, or Angle Hole diameter Level f (High Precision) Picture ≤ 63 ±0.10 ±0.10 Level m (Average Precision) 400–1000 N/A > 1000 N/A ≤ 63 63–160 160–400 400–1000 > 1000 ±0.15 ±0.15 ±0.20 ±0.30 N/A N/A 63–160 160–400 ±0.15 ±0.20 Blanking Distance between two holes Distance between a hole and an edge ±0.15 ±0.20 ±0.25 ±0.30 ±0.20 ±0.30 ±0.40 ±0.50 ±0.10 ±0.15 ±0.20 ±0.25 ±0.30 ±0.15 ±0.20 ±0.30 ±0.40 ±0.50 2019-7-21
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Distance between a line and an edge ±0.10 ±0.15 ±0.20 ±0.25 ±0.30 ±0.15 ±0.20 ±0.30 ±0.40 ±0.50 Blanking angle ① ±0°30' ±0°30' ±0°30' N/A N/A ±1.0° ±0°30' ±0°30' N/A N/A
Characteristic Diameter, Distance, or Angle Distance between a hole and a bent flange (one bend) Distance between a bent flange and a flat edge (one bend) Distance between two holes (two bends) 2019-7-21
Level f (High Precision) Picture ≤ 63 63–160 160–400 400–1000 >1000 Level m (Average Precision) ≤ 63 63–160 160–400 400–1000 > 1000 ±0.15 ±0.20 ±0.20 ±0.25 ±0.30 ±0.20 ±0.30 ±0.50 ±0.50 ±0.50 Forming ±0.15 ±0.20 ② ±0.20 ±0.20 ±0.25 ±0.30 ±0.20 ±0.30 ±0.50 ±0.50 ±0.50 ±0.25 ② ±0.25 ② ±0.30 ② ±0.40 ② ±0.25 ±0.30 ±0.50 ±0.50 ±0.75 华为机密，未经许可不得扩散 Huawei Confidential 第40页, 共45页 Page 40 , Total 45
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Characteristic Diameter, Distance, or Angle Distance between two bent flanges (two bends) Level f (High Precision) Picture ≤ 63 ±0.15 Level m (Average Precision) >1000 ±0.30 ≤ 63 63–160 160–400 ±0.25 400–1000 ±0.50 > 1000 63–160 ±0.20 160–400 400–1000 ±0.20 ±0.25 ±0.30 ±0.50 ±0.75 Distance between a flat edge and a bent flange (three bends) ±0.20 ±0.25 ±0.25 ±0.30 ±0.40 ±0.30 ±0.40 ±0.50 ±0.75 ±1.00 Distance between two bent flanges (four bends) ±0.25 ±0.20 ±0.30 ±0.30 ±0.40 ±0.50 ±0.30 ±0.40 ±0.50 ±0.75 ±1.00 Distance between two holes ±0.25 ±0.25 ±0.30 ±0.40 ±0.30 ±0.40 ±0.50 ±0.75 ±1.00 (four bends) ② ② ② ② ②
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Characteristic Diameter, Distance, Picture or Angle Level f (High Precision) ≤ 63 63–160 160–400 ±0.25 25–63 ±0.30 400–1000 ±0.30 N/A N/A >1000 Level m (Average Precision) ≤ 63 63–160 160–40400–100 00 ±0.50 ±0.75 N/A N/A > 1000 ±1.00 N/A N/A Distance between two flat edges (four bends) Partial forming Height ±0.20 ±0.25 ≤ 10 10–25 ±0.40 ±0.30 ±0.40 N/A N/A ≤10 10–25 25–63 ±0.50 ±0.15 ±0.20 ±0.20 ±0.30 Partial forming Length Forming ±0.15 ±0.20 ±0.20 ±0.25 ±0.30 ±0.20 ±0.30 ±0.50 ±0.75 ±1.00 Length of a blank holding surface (zero gap) Depth of a blank holding joint (zero gap) ±0.15 N/A N/A N/A N/A ±0.30 N/A N/A N/A N/A 0.2 N/A N/A N/A N/A 0.3 0 N/A N/A N/A N/A Depth of a blank holding joint (with gap) 0 ±0.20 N/A N/A N/A N/A ±0.30 N/A N/A N/A N/A 2019-7-21
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Characteristic Diameter, Distance, Picture or Angle Level f (High Precision) ≤ 63 63–160 160–400 ±0.5° 400–1000 ±0.5° >1000 Level m (Average Precision) ≤ 63 63–160 160–40400–100 00 ±1.0° ±1.0° > 1000 ±1.0° Bending angle ① ±0.5° ±0.5° ±0.5° ±1.0° ±1.0°
Characteristic Diameter, Distance, or Angle Level f (High Precision) Picture ≤ 63 63–160 160–400 400–1000 > 1000 Level m (Average Precision) ≤ 63 63–160 160–400 400–1000 > 1000 Size of a free-of-painting area ±1.0 ±1.5 ±1.5 ±1.5 ±2.0 ±1.0 ±1.5 ±1.5 ±1.5 ±2.0 Length of a silk screen Others Flatness ③ (with little blanking processes) Flatness ③ (with forming, welding, and piercing 2019-7-21
±0.5 ±0.5 ±0.5 ±0.5 N/A ±0.5 ±0.5 ±0.5 ±0.5 N/A 0.3 0.5 0.8 1.5 3 0.5 0.8 1.5 3 5 0.5 0.8 1.5 3 5 0.8 1.5 3 5 7 华为机密，未经许可不得扩散 Huawei Confidential 第43页, 共45页 Page 43 , Total 45
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Characteristic Diameter, Distance, or Angle processes)
Level f (High Precision) Picture ≤ 63 63–160 160–400 400–1000 > 1000 Level m (Average Precision) ≤ 63 63–160 160–400 400–1000 > 1000
The table applies only to metal sheets with depths less than or equal to 1.5 mm. For metal sheets with greater depths, the tolerances increase by around 30%. The table applies only to common metal sheets, such as cold-rolled sheets and galvanized sheets. Spring sheets allow larger tolerances. Size tolerances for high-density holes (ventilation holes) can be larger than blanking tolerances.
For tolerances for imprinted marks, imprinted words, ribs, line bridges, embossments, knock-off holes, and shutters, see the tolerances for partial forming in the table.
Size tolerances for rivet nuts, studs, or screws are ±0.05 larger than those for hole sizes.
Size segments of tolerances marked with ① correspond to the lengths of the shorter blanking flange and bent flange.
Tolerances marked with ② are adjusted based the process sequence (bending first and piercing later) and can be the distance between two holes. Size segments of tolerances marked with ③ correspond to the length of the longest diagonal line on a surface. Straightness tolerances equal the flatness tolerances.
If more than four bends are applied, tolerance for each additional bend increases by ±0.05. Tolerances for listed characteristics in the table apply to similar unlisted characteristics.
NOTE1.3.3. Remarks
The sizes, diameters, and distances and their tolerances apply to finished metal sheets that have undergone surface processing, such as passivation,
oxidation, plating, and painting.
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