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Mold component design and selection

Posted by: Fymicohuang 2021-10-08 Comments Off on Mold component design and selection

1) Determine the size of the die.
The blanking die uses an integrated die and a wire cutting machine. When the die position is placed on the die holder, the pressure center and handle center should overlap according to the pressure center data. The dimensions are calculated according to the relevant formula.

Mold thickness H = KL = 0.38 × 30 = 11.4 (mm)
Mold thickness H = 15mm
Mold wall thickness c = (1.5 ~ 2) H = (22.5 ~ 30) mm
Set mold wall thickness to c = 25mm
Die width B = L + 2c = 30 + 25 × 2 = 80 (mm)
Set die width B = 80mm
Die length L = L + 2S2 = 30 + 2 × 25 = 80 (mm)
Set the die length to L = 80mm
Die dimensions L x B x H = 80 mm x 80 mm x 15 mm

2) Select a typical combination
The shape of the punch is 80mm x 80mm x 15mm, and the typical combination is 80x80x180 to 220 (GB2873.2-81).
7.2 Concave design
1) The position of the hole. Gets the position created from the layout.
2) Aperture type. Obtained with a leading edge size.
3) Blade foam. Straight tube type, reverse hole expansion, vertical wall height inspection 1-26 is 10 mm.
4) Pinhole. The size, number and location of each screw and pin hole is in the standard standard combination GB2873.2.
5) Material and technical requirements. The material is CrWMn, the heat treatment temperature is 60 to 64HRC, and the surface roughness is as shown in the figure below.
6) Drawing of mold parts. The design results are plotted as recesses as shown below. Drawing of mold parts

7.3 Punched punch design
1) Punch check. The cross section of the punch is large and the strength and rigidity cannot be checked.
2) Structural form of punch. The circular interface punch is trapezoidal and uses standard GB2873.2. Fixed with a fixing plate.
3) The size of the working part of the punch. Obtained with a leading edge size.
4) Calculate the length of the punch. Check standard GB2873.2 and calculate punch fixing plate = 20mm, hollow pad h2 = 12mm, punch thickness h3 = 25mm, L = h1 + h2 + h3 = 12 + 4 + 31 = 47mm.
5) Material and technical requirements. The material is selected from T10A and the heat treatment hardness is 58-62HRC.
6) Drawing of punch parts. Drawings of mold parts are derived from the design results shown below.

Punching parts diagram

2. Punch and die the design
1) Punch and die wall thickness. The minimum wall thickness of punch and die (75-40) / 2 = 17.5mm meets the minimum wall thickness requirement of flip chip composite type.
2) Structural form of punch and die. For the straight type, the shape is obtained from the position where the die-cut pattern is punched out. Fixing method: Fixing with screw fixing plate;
3) Dimensions of the working part of the punch and die. Obtained from the calculation of edge size.
4) Calculate the length of the convex and concave shapes. Cross section h1 = 20mm, unloading plate h2 = 14mm, elastic part mounting height t h3 = 20mm, unloading plate is higher than uneven die 1mm, standard to get a fixed plate with punch length See GB2873.2 for various combinations.
L = h1 + h2 + t-1 = 53mm

5) Material and technical requirements. The material is Cr12, the heat treatment hardness is 58 to 62HRC, and the surface roughness is as follows.
6) Draw the convex and concave parts. The design results are plotted in concave and concave as shown in the following figure.

Diagram of convex and concave parts

3. Design of unloading parts
1) Unloading plate design
The unloading steel sheet is made of 45 steel and has a quenching hardness of 40-45 HRC. The contour of the unloading plate is the same as the contour of the blanking die and is 15 mm thick.
2) Select the unloading screw
Four unloading screws are attached to the unloading plate. The nominal diameter is 12 mm and the threads are M12 * 55 mm. The end of the unloading screw should have enough moving space for normal unloading operation. After removing the screw, the unloading screw plate must exceed 1 mm of the end face of the mold. If an error occurs, a washer should be installed between the screw and the drain plate to adjust the drain screw plate.

4. Select mold base and other parts
Formwork specifications are selected according to the external dimensions of the mold. Select two sets of guide sleeves and guide posts, large and small.
The guide column d / mm × L / mm is Φ32 mm × 2000 mm.
The guide sleeve d / mm × L / mm × D / mm is Φ32 mm × 110 mm × 45 mm.
The upper mold thickness H1 is 40 mm, the rear plate thickness is 10 mm, the fixed plate thickness is 20 mm, the unloading plate thickness is 14 mm, the die thickness is 25 mm, and the lower mold thickness is 45 mm.
Mold closing height H
H = 40 + 10 + 20 + 14 + 25 + 45-2 = 152 (mm)

5. Check the mold closing height and the related parameters of the press
5.1 Check the height of the closed type
Must meet mold closing height H.
Hmin-H1 + 10 ≤ H ≤ Hmax-H1-5 (Equation 8-1)
Where the maximum closure height of the Hmax press;
Hmin-Minimum closing height of the press.
H1 pad thickness.
According to the selected printing press J23-25, the parameter list of the inspection press is
Hmax = 320mm, Hmin = 180mm, H1 = 50mm
Import the above data into Equation 7-1 and
140 <H <265
After mold closing height H = 207 mm, open press J23-25 ​​meets the requirements in the range of 140 mm to 265 mm.

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