一. Workpieces Process Analysis
a) the workpiece material 08F, its plasticity, toughness good shear strength t = 260 ~ 360Mpa, tensile
Intensity sb for 330 ~ 450Mpa, is conducive to a variety of processes processing.
b) Work size do not have tolerance requirements, so accuracy is not high, a general part, its tolerance by IT14
Processing, mold manufacturing to bring about a series of convenience.
c) The piece belongs to the cylindrical deep drawing parts, 14 mm width on both sides of the straight edge flange, flange front-end
Has a curved section and the red one f 6 of the holes at the bottom there is a f 13 holes; workpiece cylindrical part of the
A height of 4mm, a drawing can be successful without the need for calculations to determine the number of drawing; curved part of the straight edge
Height H = 5mm> 2t, the relative bending radius r / t = 0.4 <0.5, are non-rounded bend; deep drawing parts
Easily out of the bottom of the hole, could be arranged after the drawing process.
To sum up, this piece can be cold stamping process forming.
二. Part process plan to determine
1. Mold types to determine
Workpiece tolerances IT14 level, the shape is relatively simple, but large quantities, should adopt the progressive die or compound die for
Processing.
2. Workpieces Technology program to determine
From the structure and shape of the workpiece can see, the basic processes are required for deep drawing, punching, bending, blanking and other processes.
Because the workpiece accuracy of less demanding, and high efficiency requirements from the production point of view, may be used first blanking
Preparation process of drawing blanks, and then deep drawing, punching a continuous mode, pull the workpiece to achieve the deep and bottom, and flange punching,
Last, cut waste and U-shaped pieces of curved composite mode, the completion of flange blanking and bending processes.
Therefore, the program forming process as follows: Blanking - Drawing - Punching - cut waste - bending.
This can reduce the molds, equipment and operating personnel in quantity and improving production efficiency, only three
Mold machining can be achieved. The disadvantage is the need two sets of composite mold structure is more complex and higher manufacturing costs.
Because drawing once successful, can also be used blanking, deep drawing, punching compound die, die a few
Minus two, but the process is simplified arrangements, specific process plan as follows:
Blanking - Drawing - Punching - cut waste - bending.
三. Process size calculation
1. Drawing the number and size of deep-drawing process to determine
Sheet metal thickness of 2mm, calculated according to the center line
(1) the determination of trimming margin
Flange diameter dt = (a + b + c +0.6 t) = (66-2 +10 +10 +1.2) = 85.2mm (Textbook Table
3-6) relative flange diameter of dt / d = 85.2/44 = 1.83, check materials in Table 4-3 were trimming margin d = 2.0mm, so
The actual flange diameter dt = (85.2 +2'2) »90mm.
(2) Budget blank diameter
22222
D = d1 + 2p r2d1 + 8r2 + 4d2h + 2p r1d2 + 4.56 r1 + d4 - d 3
By The figure was d1 = 24mm, d2 = 29mm, d3 = 34mm, d4 = 53mm, r1 = 2.5mm, r2 = 2.5mm, h = 5mm
Substituted into the formula too D »61mm
Deep-drawing process dimensions are as follows:
d = 46mm
0.8 () rd = D - d t = 0.8 × (90 - 46) »5.3 mm
1 p r = r = mm
h = 2mm
2. Drawing convex and concave die size calculation
(1) drawing the convex and concave die size calculation
Check materials in Table 414
Was unilateral clearance Z / 2 for the 1t; look-up table 415
Have dd = 0.08 dp = 0.05
Workpiece tolerances IT13-class, check mechanical design manual, get D = 0.39, substituting into the next two style, too
0.0 8 0.0 8
m ax 0 0 0 (0.75) d (46 0.75 0.3 9) 45.7
d D = D - D + d = - × + = +
000
m ax 0.05 0.05 (0.75) (46 0.75 0.39 2) 43.7 pp DDZ-d - - = - D - = - × - =
(2), punching, blanking punch and die edge size calculation
Punching, blanking shapes simple, the choice of exchange processing method processing convex and concave die
Precision blanking take IT11 class
Punching size:
The bottom of the hole diameter f 13mm
Zmax = 0.20t = 0.20
Zmin = 0.14t = 0.14
dd = 0.02 dp = 0.02
½ dd ½ + ½ dp ½ = 0.02 +0.02 = 0.04 <Zmax-Zmin = 0.20-0.14 = 0.06
Therefore: 00
p min 0.02 d () 13.08 p d x-d - = + D =
0.02
d min min 0 0 d = (d + xD + Z) + d d = 13.22 +
Look-up table was x = 0.75 D = 0.11
Blanking size: r off = 90mm
Zmax = 0.20t = 0.20
Zmin = 0.14t = 0.14
dd = 0.03 dp = 0.02
½ dd ½ + ½ dp ½ = 0.03 +0.02 = 0.05 <Zmax-Zmin = 0.20-0.14 = 0.06
Therefore: 0.03
d max 0 0 D = (D - x D) + d d = 89.86 +
00
p max min 0.02 () 89.72 p DD x Z-d - = - D - =
Look-up table was x = 0.75 D = 0.19
(3) curved convex and concave die size calculation
Punch radius: 0 0.5 p r = r =
Die radius: R 4t = 8 Au =
Convex and concave die unilateral gap: Z = t + D + ct = 2 + 0.09 + 0.1 = 2.19 (check materials Table 34
And 35)
Convex and concave die horizontal dimensions:
d 0.098
d max 0 0
00
p d p 0.098
L (L 0.75) 65.71
L (L 2Z) 61.33
d
d
+
- --
= - D =
= - =
3. Layout and materials utilization
The nesting blanking process according to the design, consider the mold structure is simple and easy to operate, it is a single-row layout
设计. Look-up table 214
Get a = 1.2mm, b = 2.0mm, the strip B = D + 2 a = 90 +2 +2 = 94mm, into the distance h
= D + b = 90 +1 = 91mm
Material utilization
22
0
100% / 4 100% 90 / 4 100% 74.3%
9194
S D
S B h
p p
h
×
= '=' = '=
× ×
4. Chong pressure and pressure equipment selection
Drawing force:
1 1 3.14 46 440 63.5 b F = pd ts K = × × = kN pull
F pressure = 0.25F = 16kN
Punching power:
F = KLtt = 1.3 × p × (D + 2r + r) × 350 »164kN cut side hole Bottom
Fz = F la + F pressure + F CD = 240kN
Press Nominal pressure:
Take Fg = 1.6Fz = 380kN
According to Chong pressure can be primary stamping device model JH21-45.
四. Die Sketch
Blanking, punching, drawing the following diagram of compound die
Cut waste, bending slightly compound die