•Harder materials need bigger clearance, more tool relief & higher speed 当剪切较硬的线材时, 需要更多的间隙, 表面退让(退剪槽)和更快的速度. •Too loose the COD / COK diameters will bend the blank and cause taper ends 剪刀/ 剪体的内孔直径太大时, 会造成线材弯曲, 线材末端缩小. •Shearing without lubricants causes short tool life 无润滑剪切会缩短模具寿命.
Assembly and setup of main dies • Basic of Cold Forming
正挤压
反挤压
打头
Assembly and setup of main dies • Basic of Cold Forming
冷锻的基础知识
A combination of discipline, skill, knowledge & continuous improvement.
10 Jan 2011
1. Assembly and setup of COD & COK 剪刀/剪模组立
Assembly and setup of COD & COK 1 Types of Shearing 剪切类型
COK: Cut Off Knife 剪刀 COD: Cut Off Die 剪体
Tool Steel 模具钢 Carbide 钨钢
Assembly and setup of COD & COK 6
1. 2. 3. 4. 5. 6.
Main Process Parameters 主要参数
Material Hardness 材料硬度 COK/COD Clearance 剪刀/ 剪体间隙 COK/COD Diameters 剪刀/ 剪体内孔直径 COK Speed 剪刀速度 Lubricants 润滑 Types of COK 剪刀类型
Assembly and setup of main dies • Types of Die Design 模具设计的类型
Solid Main Die 实心主模
Step Solid Main Die 台阶实心主模
Die-Piece / Casing / Insert
套片整装主模
Step Die-Piece / Casing / Insert
Assembly and setup of COD & COK 7 Understand Defects 缺陷分析
?
1. 2. 3. 4. 5. 6. Poor Sheared Surface: small clearance and no tool relief 剪切面粗糙: 间隙太小/ 没有表面退让 Burr: COK or/and COD worn off 毛刺: 剪刀/ 剪体磨损 Tongue: small clearance and no tool relief 舌状毛刺: 间隙太小/ 没有表面退让 Bent Blank: COK/COD diameter too big 线材弯曲: 剪刀/ 剪体内孔直径太大 Oval Shape: COK/COD diameter too big 椭圆形: 剪刀/ 剪体内孔直径太大 Big Roll-over: clearance too big and Tool worn off 曲面大: 间隙太小/ 模具磨损
模具尖角太锋利造成模具脆裂或破损
Assembly and setup of main dies • Compressive Stress 压应力
1.
0.5% hot-shrinkfit interference 0.5% 预热组合的 过盈配合量
Proper compressive stress to reduce material breathing during forming
主模组立
Assembly and setup of main dies
• • • • • • •
Basic of Cold Forming 冷锻的基础知识 Materials for Die Construction 模具的材质 Types of Die Design 模具设计的类型 Importance of Die Surface Finishing 模具表面加工的重要性 Compressive Stress 压应力 Good Die Assembly 正确安装模具 Defective Parts / Poor Die 缺陷部件 / 劣质模具
Tool Life Shorter
模具寿命较短
Some Assembly Problem
某些组装问题
Some Assembly Problem
某些组装问题
Difficult to Alignment
对齐困难
Difficult to Alignment
对齐困难
Short Die-piece Life
套片寿命短
落料无法控制 剪切方式不同 线材不直 曲面较大 成本低廉 安装简易 模具寿命较长
Assembly and setup of COD & COK 2 Basic Mechanism of Shearing (Complete Cut 全剪)
1. 2. 3. 4. 5. 6.
Need Relief Surfaces Careful Control of Clearance Difficult COK/COD Alignment Better Shear / Quality Achieve Straight Blank Small Roll-over
曲面 塑性剪切 二次断裂 / 舌状毛刺 毛刺 直线性
Assembly and setup of COD & COK 4 COD & COK Setting 安装 Relief 表面退让 （退剪槽〕
Small Radius 小圆角
Relief 表面退让 （退剪槽〕
Assembly and setup of COD & COK 5 COD & COK Materials 材料
Assembly and setup of COD & COK 2 Basic Mechanism of Shearing (Half Cut COK) 半剪
1. 2. 3. 4. 5. 6. 7.
No Control of Blank Different Shear Patterns Blank Not Straight Big Roll-over Low Cost Easy to Setup Long Tool Life
Short Die-piece Life
套片寿命短
High Cost
成本昂贵
Very High Cost
成本最昂贵
The REASON for different die designs 不同模具设计的成因
Assembly and setup of main dies • • • • • Importance of Die Surface Finishing
生产良好的冷锻件， 操作者需要 具备: 纪律, 技能, 知识和持之以 恒的进取精神。
Assembly and setup of main dies • Materials for Die Construction 模具的材质
Hot Work Steel 耐热钢
High Speed Steel 高速钢 Carbide Insert 钨钢
需要表面退让（退剪槽〕 间隙要求高 剪刀、剪体对齐困难 较好的剪切质量 剪断的线材较直 曲面小
Assembly and setup of COD & COK 3 Common Blank Quality Issue 常见的线材剪切质量问题
1
4 2 3 4 4 3
1. 2. 3. 4. 5.
Roll-over Plastic shear Secondary Fracture / Tongue Burr Straightness
Assembly and setup of main dies • Good Die Assembly 正确组装模具
Assembly and setup of COD & COK 2
1. 2. 3. 4. 5. 6.
Basic Mechanism of Shearing
Elastic Deformation 弹性变形 Roll-over 曲面 Plastic shear 塑性剪切 Initial Fracture 初始断裂 Final Fracture 最终断裂 Physical Separation 实际剪断
Contents of the Training 培训内容 • • • • • • Assembly and setup of COD & COK 剪刀/剪模组立 Assembly and setup of main dies主模组立 Assembly and setup of punches冲头组立/失效分析 Understand steel & carbide tools模具组立/材料/钨钢 Understand tool surface & friction 模具表面/摩擦系数 / Understand the effect of preform预成形分析
Clearance Too Big 间隙太大
Optimum Clearance 最佳间隙
Clearance Too Small 间隙太小
Quality Problems:- 质量问题 1. Oval Shape 椭圆形 2. Tilting 歪斜 3. Poor shear 剪切面粗糙 4. Burr 毛刺 5. Not Straight 不直