How to calculate the force of U-shaped die

1. With a few more holes, the material section coefficient w changes. The bending moment diagram is made according to the stress direction. δ= There is this calculation method in t / W material mechanics.

2. Here is a calculation method, no case, hope to help you. Taking the bending of U-section as an example, this paper discusses the relationship between the length expansion of non plate bending (such as bending of angle steel, channel steel, etc.) and the bending degree, bending scheme and die structure, and obtains the calculation formula for design reference through theoretical derivation and experimental verification. 1. When the bending degree is small (R / h = 10), the locus of the strain neutral layer coincides with the center of the bending blank section. In other words, the formula l can be used for any angle of internal bending= π( R+b-Z0)(180 °-β)/ one hundred and eighty °， The formula l can be used when bending at any angle= π( R+Z0) α/ one hundred and eighty ° Where Z0 = ey = (1+ π R2-l2-4R2- δ/ 4l1+2l2+2 π R2+ πδ)δ+ 2(l1+R2)2+( π- 3)R22/4l1+2l2+2 π R2+ πδ 2. When the bending degree is large (R / h ＜ 10), the strain neutral layer does not pass through the section center of gravity and moves to the inside. The displacement coefficient X 'of the neutral layer in this kind of bending can be replaced by the displacement coefficient X of the corresponding plate bending by the value of R / h or R / (2z0). When bending at any angle, the unfolding length is L= π( R+2Z0x) α/ one hundred and eighty ° When the inner bending angle is arbitrary, the unfolding length is L= π[ R+H-2Z0(1-x)](180 °-β)/ one hundred and eighty ° 3. In the case of flanging before bending, the center of gravity distance is taken as the calculation basis of neutral layer position. First, calculate the value of R / h. Secondly, the corresponding calculation formula is selected according to the bending degree. In the case of bending first and flanging later, the calculation method of bending unfolding length should be plate bending. Only when determining the position of neutral layer, the relationship between neutral layer and bending degree should be considered, that is, when the relative bending radius R / T ≥ 5 and when the relative bending radius R / T < 5. 4. When the die structure is non pressure material, its bending mode is flanging and bending, so it should be calculated by step flanging and bending method. When the die structure is pressed, the appropriate calculation formula is selected according to the comparison of pressing force and free bending force. 5. By analyzing the mechanism of bending and springback, the influencing factors of springback value are indicated. At the same time, starting from the determination of springback angle of plate bending, this paper analyzes the calculation basis of how to determine the springback angle of type material bending, and puts forward the calculation method and calculation steps of determining the springback value of type material bending.

3. The calculation formula of punch pressure P = kltf
where k is the blanking coefficient, generally 1.3
L is the circumference of the proct after stamping, unit: mm
t is the material thickness, in mm
F is the shear strength of the material, in MPa

4. The solid part is divided from the outer edge of the center of the U-shaped section, half of which is in the upper die; Half in the bottom mold
the outer surface of the hollow core is the same as above, and the inner surface is designed to be side core pulling in the form of chain link.

5. The standard calculation formula provided by Sumitomo of Japan:

clamping force = (proct area + runner area) cm2 x material coefficient kgf / cm2
the material coefficient is as follows:
PC as = 300-500 kgf / cm2
PA PP PE ABS = 400-600 kgf / cm2
POM PMMA = 600-1000 kgf / cm2
PC = 800-1200 kgf / cm2
when glass fiber (GF) is added 100-200kgc / cm2

6. Injection quantity and clamping force are for injection molding machine, which has nothing to do with the mold
determination of clamping force
clamping force (also known as clamping force) is an important parameter of injection molding machine, that is, clamping force applied to the mold by injection molding machine. The clamping force, like the injection volume, reflects the ability of machining procts to a certain extent, and is often used as the main parameter to indicate the size of machine specifications
according to the vertical projection area of the injection molded part on the template (head plate or second plate), the, Calculation of clamping force P:
clamping force = clamping force constant x projection area of the proct
i.e. P = KP. S
where p-clamping force (T)
s-vertical projection area of the proct on the template (cm2)
KP clamping force constant (T / cm2)
KP plastic name KP
PS 0.32 nylon 0.64 ~ 0.72
PE 0.32 acega l)
PP 0.32 glass fiber 0.64 ~ 0.72
ABS 0.30 ~ 0.48 other engineering plastics 0.64 ~ 0.8

for example:
suppose that the projection area of a proct in the vertical direction of the head plate or the second plate is 410cm2, and the proct material is PE, calculate the required clamping force
from the above formula, the formula is as follows:
P = KP. S = 0.32x410 = 131.2 (tons)
for the sake of stable proction and safe loading of injection molding machine, the clamping force of general injection molding machine is 1.17 times larger than the actual clamping force of procts
therefore, 131.2x1.17 = 153.5 (tons) injection molding machine should be 160 tons< The first mock exam is the br / > injection volume, which is the density of the material and the weight of the material required for the proct. The first mock exam is that the injection volume is 70g, then the injection molding machine needs 100g injection tube. The actual volume of the injection is 70% of the volume. Too large is easy to make insufficient, too small material is easy to decompose at high temperature for a long time.

7. For distilled water U-tube, read the difference between the two tubes. Generally, a small cell (the minimum scale of 1 mm) is 9.8 PA, which can be calculated according to this.

8. It has a lot to do with the material and the thickness of the material. The matching of the concave convex die and the size of the blank holder force are very complex. So we have to be specific to the workpiece to calculate, there are a lot of empirical values.

9. I'm in a mold & book& lt; Practical course of injection mold design & gt& gt; The formula for calculating the clamping force is as follows:
clamping force ≥ bulging force ÷ 80%
bulging force = proct projection area × Cavity pressure (MPA) × Number of molar cavities

10.

1. Determine the amount of injection --- assuming that the theoretical weight of the part is 80g. The maximum injection volume of screw barrel is calculated, and the selection range is 80 / 0.75 = 107g to 80 / 0.25 = 320G. The size range of screw barrel of injection molding machine is 107 ~ 320

2. Determine the clamping tonnage --- calculate the clamping tonnage = (proct orthographic projection area (CM) * beer number + runner area) * material viscosity coefficient

material viscosity coefficient: General PP 0.3 ~ 0.4 PA / PC / POM 0.65 ~ 0.75. You can check online

3. Determine the size of the clamping mechanism according to the size of the mold base