Should the side pressure be included in the calculation of blank
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.
F impulse = KLT τ ， Where f -- blanking force, K -- coefficient; The safety factor is generally taken as 1.3 considering the wear of the cutting edge of the blanking die, the fluctuation of the clearance between the punch and the die (the variation or uneven distribution of the value), the lubrication condition, the variation of the mechanical properties of the material and the thickness tolerance, etc. L -- total length of blanking periphery, mm; T -- material thickness, mm; τ—— Material shear strength, MPa
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extended data:
stamping advantages
1. High proction efficiency, convenient operation, easy to realize mechanization and automation. This is because stamping depends on the stamping die and stamping equipment to complete the processing. The stroke times of ordinary press can reach dozens of times per minute, and the high-speed pressure can reach hundreds or even thousands of times per minute, and each stamping stroke can get a stamping part
2, stamping, stamping die ensures the size and shape accuracy of stamping parts, and generally does not destroy the surface quality of stamping parts, and the life of dies is generally longer. So stamping quality is stable, interchangeability is good, and has the same characteristics. p>
3. Stamping can process parts with large size range and complex shape, such as the second hand of clock and watch, the longitudinal beam and panel of automobile, and the cold deformation hardening effect of material ring stamping, the stamping strength and stiffness are higher
Stamping is a kind of material saving and energy-saving processing method, and the cost of stamping parts is lowThe blanking force of the stamping is 1.3 factor X (34 + 34 + 132 + 82 + 27 + 47 + 82 + 20), perimeter x 2, material thickness x 310, stress = 37 tons
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:
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:
where
F -- blanking force
L -- punching peripheral length
T -- material thickness
-- material shear strength
k -- coefficient
Thecoefficient K is a correction factor given considering the influence of the fluctuation and non-uniformity of die clearance value, the wear of cutting edge, the fluctuation of sheet metal mechanical properties and thickness in actual proction. Generally, k = 1.3
in order to simplify the calculation, the blanking force can also be estimated according to the following formula: