How to calculate die blank holder force

1. For separation process:
calculation of punching force

in blanking process, punching force refers to the general term of
, unloading force, pushing force and pushing force. Punching force is the main basis for selecting
and also the necessary data for die design<

1.
calculation

is the pressure exerted on the sheet by the punch in the blanking process, which changes with the depth of the punch into the material. The blanking force F can be calculated as follows:
F = KLT τ
where f -- blanking force, N
k -- coefficient; Considering the wear of
cutting edge, fluctuation of clearance between punch and die (variation or uneven distribution of values), lubrication, variation of
and thickness tolerance and other factors,
is generally set as 1.3
L -- total length of blanking periphery, mm
T -- material thickness, mm< br /> τ—— Material
, MPa
when
cannot be found τ It can be used
σ B substitute τ， In this case, the approximate calculation method of k = 1 is adopted. That is,
F = Lt σ B
where σ B -- material
, MPa

2. Calculation of unloading force, pushing force and pushing force
after blanking, the force required to scrape the material from the punch is called unloading force; The force required to push the part or scrap from the die is called pushing force; The force required to eject the part from the die is called ejecting force. In the actual proction, it is generally calculated as follows:
unloading force F = k unloading f punching
pushing force F = NK pushing f punching
pushing force F = k jacking f punching
where f punching -- blanking force, N
k unloading - unloading force coefficient, whose value is shown in the table
k push -- push force coefficient, whose value is shown in the table
k top -- the force coefficient of the top part, whose value is shown in the table
n -- the quantity of parts or scrap accumulated in the die (n = H / T); H is the height of the straight edge; T is the material thickness.

2.

Blanking force is the pressure exerted by the punch on the sheet metal in the blanking process. It changes with the depth of the punch into the material (punch stroke). Generally speaking, the blanking force refers to the maximum value of the blanking force, which is one of the important basis for selecting the press and designing the die. When blanking with ordinary flat edge die, the blanking force F is generally calculated as follows:

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. All forces have to be calculated. If it's blanking, blanking, pushing force, jacking force, etc. should be calculated. Together, I don't know what type of stamping you are talking about. As for the selection press, it's better to choose one whose rated pressure is twice of the blanking pressure

5. It's Wang Yijiu

6. The pressure of the stamping die is related to the strength of the material, the thickness of the material and the circumference of the punch edge.

7. 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 (m
PA) × Number of molar cavities

8. Surface area of ring s = 4* π^ 2*r*(R+r)