Key words: key, stamping, process, mold
Abstract: key production into mass production, the aluminum alloy material, including punching,
blanking, two working procedure, precision parts, determine the first punch blanking, after adopting
progressive die production. For mould design and calculation, and the convex model component
and its structure, die components, positioning parts, unloading and push the pieces of parts to carry
on the design, to complete the mold assembly drawing.
1. The stamping technology analysis of blank keys
As shown in figure 1, parts production to mass production, the material is 2 mm thick aluminum
alloy plate. There is hole. The artifacts including punching, blanking, two working procedure,
precision parts, all take the free size of workpiece, ordinary mold can meet.
Fig.1 Key part drawing
2. The scheme determination of stamping
The artifacts including blanking, punching and cutting edge, can have the following plan:
Scheme 1: punching blanking, after first USES the level into a mold production.
Scheme 2: blanking - bending - punching compound stamping, with composite mold production.
Focus two mould process, forming at a time. But abrasive complex, various parts of the
processing difficulty is big, need more parts and complex; Plan a need a pair of mold production
efficiency while the mould structure complex but simple geometry mould manufacturing is not
difficult, because parts by comparing these methods, the scheme adopts the scheme one is preferred.
3. The layout and sure
Stamping on the strip or sheet metal decorate a method known as the layout. Layout of the principle
is the same as the ordinary cutting. If parts are not required to rolling direction of the material, the
layout of the aim is to ensure that process needs and ensure that the workpiece cutting surface
quality under the premise of minimizing waste. In addition, for shape on both sides of the shear
plane parts quality requirements are different, the layout should put high demands on one side of the
feed direction, so that it is on the cutting quantity.


3.1 Material utilization
Actual area and blanking pieces used sheet metal area of the percentage of material utilization, it is
the technical and economic indicators of rational utilization of materials.
A step away from internal material utilization available  η under said:
0
100%
S
S
η = ×
=S/(AB) ×100%
S - actual area of artifacts;
S 0 - materials area, which includes artifacts area and waste area;
A - interval (adjacent) distance between two corresponding points of the parts; The positioning
in the design of 14.5;
B - the strip width.
3.2 Layout method
According to material utilization degree, economic layout method can be divided into waste, less
waste, and no layout three kinds of waste. According to the parts on the strip layout, layout and can
be divided into straight, oblique row, the row and mixed row, row, etc. Look from artifacts, there
are scrap layout method are all the parts of neighboring contour cutting, in the article as well as
parts and material between the sides, between the process excess stock all exist. Due to the material
on the left side, so the parts quality and mold life is higher.
3.3 Take a side
Layout between blanking pieces and when the article with the material between the side blanking
pieces left in the process waste is called on. On has two functions: one is to compensate the position
error and shear plate, to ensure rush out qualified parts; Article 2 it is can increase the stiffness,
material sent to convenient, improve labor productivity.
On width hedge cutting process and cutting quality has a great influence, on big, low material
utilization; On hour, on the strength and rigidity is not enough, will be pulled in blanking,
sometimes even unilateral pull in abrasive clearance, cause uneven blanking force, damage the
mould parts. So take a boundary value Settings should be reasonable, its value is determined by
experience. In general, hard material boundary value can be smaller, soft materials, brittle materials
by boundary value should be bigger; With manual feeding, lateral pressure device of a boundary
value can be smaller. On the value of the experience data to check the design manual.
3..4 Determine the width of materials
Under the layout scheme and boundary value was determined, can determine the strip width and the
distance between the guide plate. Should be considered in the process of feeding by the motion of
the strip material reduce side by side. To compensate for the side cut of, strip width should be add a
strip material could swing the momentum.
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4. Select the mould structure form
The mould structure is as follows in figure 2:
Fig.2 Mold structure
This design USES the typical progressive die mold. Installed in the upper die parts have the key
6 and punch punch, punch through the fixed plate punch 5, 13 with stud plate and positioning pin
and mold base on the 2 together. Installed in mold parts die of 8 and 9 with stud and the lower die
plate is fixed together, and die with guide pin 7 guide sleeve 11 guide.
4.1 Mould design calculation
4.4.1 blanking force design calculation
For ordinary flat edge blanking F = KLt τ, k- coefficient, often take 1.3, L for stamping the
perimeter, tau as shear strength MPa, t is thickness.
F = KLtτ = 1.3 * 130 * 105 * 2 = 3.5 KN
4.1.2 Press required total pressure calculation
Using pressure unloading device and a total die F  Z = 3.5+0.175+0.21=3.885KN
4.1.4 feeding interval with the material width is calculated
Feeding interval. A, A=D+a=22+2=24mm
Strip width B = 62
4.2 working parts design calculation
4.2.1 Punch component and its structure design
By a workpiece shape structure and the die structure the convex mould should be used in ordinary
punch, punch has two, respectively punch punch, punch blanking. Length L = 18 mm there are die
structure design for punch material, mould parts should have high wear resistance, and can
withstand the impact under the impact, so should have high hardness and suitable toughness.
Concrete by the same group of students collective parts for the craft analysis after draw detail
drawings with good results will be described in detail below.
4.2.2 Die components
Die hole shape with terraced, die outline dimension drawings as follows:
Die on next template fixed by screws, the positioning pin, and type are the technical
requirements for die hole axis and the top surface should be kept vertical, bottom, and top die
surface should be parallel.
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4.2.3 Holdings positioning parts
The positioning of the die parts to control the material correctly sent to the correct position of the
hair and a single embryo. Keep-off device
Is used to guarantee the blank can be smoothly inserted into the rectangular hole, should
guarantee in holes and positioning device has a certain gap between piece of rectangular hole. Size
is 14.4 * 7.4.
4.2.4 Unloading and push the pieces of parts
Discharging device one larger than the key shape hole among them, facilitate blanking.
Push the pieces of parts mainly have the effect of transmission power, to mould a certain external
force. Thereby giving impetus to the movement of mould regularly.
4.2.5 Die set
Die set consists of upper and lower die holder, mold handle and guide, guide pin, guide sleeve). Die
set has been standardized, check mechanical design manual selection side guide column formwork,
blanking pieces when the thickness is 0.8 ~ 4 mm, guide pillar and guide bush choose H7 / h6
cooperate  Ⅱ level precision die set.
Die check mechanical design manual selects the thread handle fixed mode on the handle.
4.2.6 Die shut height, die to the press
Mould the height H of mould should be between the maximum loading of press die height between
Hmin Hmax and minimum loading mode, otherwise it cannot be installed and working properly.
The following relationship:
Hmin+10mm ≤ H die ≤ Hmax-5mm