English 
Views: 201 Author: Site Editor Publish Time: 2023-08-22 Origin: Site
The use of industrial vacuum suction cups on automated production lines has become commonplace due to their convenience. In order to find the most suitable suction cup for optimum performance, it is essential to know how to calculate the vacuum suction force.
The basic formula F = PxA is used to calculate the force of a suction cup with.
F is the holding force (or vacuum force of the suction cup).
P is the pressure
A is the contact area (the size of the suction cup surface).
This is derived from the definition of pressure, i.e. P = F / A.
Explain the vacuum force equation F = PxA
Gravity and friction are the two main forces that make vacuum suction work. Gravity pulls the molecules in the air towards the earth, creating atmospheric pressure, while the suction cup and the vacuum pump create a pressure difference that connects the two surfaces.
The suction cups touch the surface of the workpiece, creating a sealed space. A vacuum jet or vacuum pump pulls the air out of the suction cup.
By removing the air pressure from the suction cup, a vacuum pressure is created on the surface of the workpiece. The difference in air pressure is used to calculate the holding force of the vacuum chuck.
Calculation of the holding force
Theoretically, the calculation of the suction force is influenced by these factors
Type of material of the workpiece (steel, glass or wood ......)
Surface properties (smooth, flat, rough or oily...)
Size of the workpiece
Mass of the workpiece m (by multiplying the length, width, height and density)
Acceleration of the system (m/s²)
Gravitational acceleration (9.81 m/s²)
Calculating the mass, holding and breaking forces is the first step in helping to design a suitable industrial vacuum chuck.
The calculation of forces also requires attention to the coefficient of friction μ, the safety factor S, the position of the gripper and the direction of movement (vertical or horizontal).
Safety factor S
In the decomposition formula for calculating the vacuum forces, a safety factor S or safety value S is added to prevent possible accidents during the operation of the vacuum equipment.
The safety value S is regulated according to the characteristics of the workpiece surface and the position of the suction device as follows.
A minimum value of 1.5 is applied to smooth and tightly compacted material workpieces.
Between 1.5 and 2.0 for horizontal suction grip positions where the applied load acts vertically on the suction cup.
For heterogeneous workpieces, porous materials or rough surfaces, at least 2.0.
The safety value S should also be 2.0 or higher for workpieces with oil, in a vertical suction grip position, or moving in a rotating motion.
Friction coefficient μ
Another key factor to consider when calculating vacuum forces is the friction that defines the tangential force.
The vacuum pressure formula uses the coefficient of friction μ to describe the resistance between the workpiece surface and the suction cup.
Unlike the safety factor S, the exact specification of the coefficient of friction μ can only be determined by appropriate experimentation.
This value varies depending on the material of the workpiece and the characteristics of its surface.
The following are theoretical guideline values for reference
For oily surfaces: μ equals 0.1
For wet surfaces: μ varies from 0.2 to 0.3
For most materials (e.g. metal, wood, stone, glass). μ equals 0.5
For rough surfaces: μ equals 0.6
