On the problem of adsorbing objects with micro vacuum pumps
When using a miniature vacuum pump for object adsorption, it actually uses the pump to vacuum the suction cup and then sucks the object. Therefore, you must choose a true miniature vacuum pump, such as PK, PC series
It is theoretically possible to calculate the size of the adsorption force. Methods as below: F≈10 ̄ ̄ ̄² (101P absolute pressure) S sucker area In the above formula,
F: Theoretical adsorption force, unit: Kgf (kg force)
P absolute pressure: is the absolute vacuum degree of the micro vacuum pump, the unit is KPa (kPa)
S sucker area: the effective area of the sucker, the unit is cm² (square centimeter)
For details about unit conversion, see From the above formula, it can be seen that the size of the adsorption force is theoretically independent of the flow rate of the pump, but in actual use it is related to the flow parameter. The reason is as follows: because the air circuit system cannot achieve theoretical sealing, there is always a certain amount of leakage. In this case, the larger the flow rate of the miniature vacuum pump, the smaller the proportion of leakage, which is more conducive to the pump maintaining a higher vacuum degree, thereby obtaining a greater adsorption force. For example, if there are two pumps with the same ultimate vacuum degree, pump A has a flow rate of 1 L/min, and pump B has a flow rate of 20 L/min. Similarly, in the case of a leakage of 0.1 L/min, the vacuum degree of pump A will decrease a lot. Because the leakage of 0.1 L/min is too large for it. However, the leakage of 0.1 L/min is not a big deal for pump B, and it can still maintain a high vacuum. Therefore, although the vacuum degree of the two is the same, in practice, the adsorption force produced by the B pump is greater.
Therefore, the vacuum and flow must be considered at the same time when the pump is selected. It is impractical to only focus on the vacuum index. Regarding the speed of the adsorption time, please refer to: About the release of the object after being attracted. When it is necessary to release the sucked object, the pump must be stopped first, and the vacuum must not be continued. After the pump stops, the object may not fall off immediately, because the pump has a certain pressure holding capacity, and the vacuum will continue to be maintained for a while. To release immediately, the gas system should add another branch, connect an on-off valve, stop the pump and open the valve at the same time, immediately eliminate the vacuum of the gas system, so that the object can be reliably released.