What is a vacuum generator

Suction cup is a kind of pneumatic element which works by reducing the air pressure in the temporary sealing space formed after contacting with the workpiece and using the pressure difference between the inside and outside.

Working principle

Material and classification

Material table

Characteristic

1、 Easy to lose. As it is generally made of rubber, it is in direct contact with objects and wears quickly, so it needs to be replaced frequently.

2、 Easy to use. No matter what material the workpiece is, it can be used as long as it can be sealed. Compared with the electromagnetic chuck, which can only be used for ordinary steel, it has outstanding advantages.

3、 No pollution. Vacuum suction cup does not produce light, heat and electromagnetic. It is especially environmentally friendly and will not pollute the environment.

4、 No damage to the workpiece. Due to its working principle and material characteristics, the vacuum suction cup will not cause any damage to the workpiece when it is adsorbed or released. Compared with hook type and wire rope type slings, the advantages of vacuum suction cup are obvious in the field of especially strict requirements for workpiece surface.

Calculation formula

1、 Calculate workpiece weight

m=L x W x H x ρ

M = mass (kg)

L = length (m)

W = width (m)

H = height (m)

ρ = density (kg / m3)

2、 Force on vacuum suction cup

1. The vacuum suction cup is horizontal and the force is vertical

Place the vacuum sucker on the horizontal workpiece and move vertically

Fth = m x (g+a) x s

FTH = theoretical grip (n)

M = mass (kg)

G = acceleration of gravity (9.81 M / S2)

A = acceleration of the handling system (m/s2)

Take emergency power off into account

S = safety factor - Minimum 1.5, rough porous and leaky surface ≥ 2.0

2. Vacuum suction level, force level

Place the vacuum sucker on the horizontal workpiece and move horizontally

Fth = mx(g+a/μ)xs = (mg+ma/μ)x s = (mg+Fa/μ)x s

FTH = theoretical grip (n)

FA = acceleration force = MxA

M = mass (kg)

G = acceleration of gravity (9.81 M / S2)

A = acceleration of the handling system (m/s2)

Take emergency power off into account

μ = friction coefficient

=0.1 oily surface

=0.2-0.3 wet surface

=0.5 wood, metal, glass, stone surface

=0.6 rough surface

S = safety factor - Minimum 1.5, rough porous and leaky surface ≥ 2.0

3. The vacuum suction cup is vertical and the force is vertical

Place the vacuum suction cup on the vertical workpiece and move vertically

Fth = m/μx(g+a)xs/y

FTH = theoretical grip (n)

FA = acceleration force = MxA

M = mass (kg)

G = acceleration of gravity (9.81 M / S2)

A = acceleration of the handling system (m/s2)

Take emergency power off into account

μ = friction coefficient

=0.1 oily surface

=0.2-0.3 wet surface

=0.5 wood, metal, glass, stone surface

=0.6 rough surface

S = safety factor - Minimum 1.5, rough porous and leaky surface ≥ 2.0

3、 Theoretical grip allocated to each suction cup

F = theoretical grip spread over each suction cup (n)

FTH = theoretical grip (n)

N = number of suction cups

CTH = theoretical weight of each suction cup (kg)

G = acceleration of gravity (9.81 M / S2)

△ P = internal and external pressure difference (bar)

Value equivalent to% vacuum

S = suction cup area (i.e. effective adsorption area) (cm2)

4、 Calculation of suction cup diameter

For circular suction cups only

D = diameter (mm)

FTH = theoretical grip (n)

N = number of suction cups

△ P = internal and external pressure difference (bar)

Value equivalent to% vacuum

Selection of suction cups

We consider it from three aspects: working environment, surface condition and operation mode. Working environment refers to corrosion, ozone, alcohol, temperature, etc.; surface condition refers to the roughness, porosity, oil, etc. of the workpiece surface; operation mode refers to the adsorption state, moving direction and operation frequency of the workpiece. According to the past experience, we will make a brief description of the application scope of various suction cups, hoping to help you in your choice.

1、 Flat suction cup

It is suitable for a wide range of applications, especially when the workpiece needs to be turned over. Compared with the corrugated suction cup, the utility model has the advantages of small volume, smaller internal space and direct connection with the vacuum generator. When it is used for thin-walled workpiece, it will not cause permanent deformation; it can also better resist radial force under high acceleration; it can be used when the suction cup is parallel or perpendicular to the horizontal plane.

2、 Corrugated suction cup

It has good buffering property and can adapt to curved surface and uneven surface. Except for automobile suction cup, it is generally not allowed to be used perpendicular to the horizontal plane.

3、 Foam sucker

It has very good softness and can be applied to the workpiece with very rough surface.

4、 Special suction cup

It is suitable for workpieces with special requirements. We can provide corresponding solutions according to your specific requirements.

5、 Manual suction cup

Different from the above pneumatic suction cup, it does not need external air source. It adsorbs the workpiece by changing the shape of the suction cup itself or extracting the air inside the suction cup with a hand pump. There are two kinds of suction cups, one is plane suction cup and the other is curved suction cup. They are mainly used for handling and fixing the workpiece with very smooth surface, such as glass, stainless steel plate and painted objects.

6、 CD sucker

Most of them are closed ring or semi closed ring, mainly made of silica gel. Dedicated to the disc industry.

7、 High temperature resistant suction cup

Up to 400 ℃ (in a short time), suitable for high temperature steel plate, aluminum plate and glass plate.

8、 Sealing strip

It's a part of the ring suction cup. It is mainly used for rough surface workpieces, such as concrete prefabricated parts, refractory bricks, rough processed natural stones and ground glass, etc.

9、 Special suction cup for suction pen

All are flat thin lip suction cups, mainly made of conductive silica gel. It is mainly used for thin and light workpieces such as integrated blocks and solar cells.

10、 Non contact suction cup

It is especially suitable for very thin, porous or surface sensitive workpieces, such as paper, chips, solar cells, thin boards, printed circuit boards and films.