Chapter 1 Introduction
Definition of stamping ----a plastic forming method
Raw material----sheet metal or non-metal
Tool ----die
Equipment----press
Result----separate or deform, workpiece with shape, dimension and property.
冲压是塑性成形加工方法之一.以板料(金属,非金属)为原料,利用模具在压力机上对板料施加压力使其分离或变形获得所需零件.所需零件具有一定形状,尺寸和性能.
Basic requirement used in sheet forming
Formability, surface quality, tolerance in thickness, and economy
Basic processes
cutting processes(分离工序): shearing, blanking, punching, parting, lancing, shaving
plastic deformation processes(成形工序): bending, deep drawing, spinning, bulging, flanging
Chapter 2 Shearing, Blanking and Punching
1. Shearing
Equipment: straight parallel cutters t↑B↓
straight inclined cutters t↓B↑
2. Blanking and punching mechanism
(1) 3 deformation stages
(2) Features of sheared edges of the sheet metal
4 parts---- rollover, burnish zone, fracture, burr (reason); main affecting factors (3 aspects)
3. Blanking and punching clearance
The effect of the amount of clearance between the punch and die on the operation process
features of sheared edges
dimensional precision
force and power
die life
4. The calculating of punch and die blade size
(1) Principles of calculation: benchmarks, limit dimension
(2) Methods of calculation: separately, coordinately
(3) Steps
Punch force
(1) k =1.1~1.3 (why 3 reasons: c, t and property, cutting edges)
(2) Affecting factors (4, material, c, t, shape)
(3) Method to reduce the punch force (3, heat, staggered punches, bevel-cut edges)
Stripping force, Knock-out force, Ejecting force
Material economy
Layout: definitions: layout, technical scrap, structural scrap
classification: type of scrap (3),
Scraps: definition
functions (3, compensation, rigid sheet, protect dies)
affecting factors (4, material, shape and dimension, t, guide and stop way)

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