Porous CNC vacuum suction cup, some people call it multi-point CNC vacuum suction cup. Compared with CNC vacuum suction cups with sealing strips, the main advantages are fast clamping, the ability to process special-shaped workpieces, and the ability to mill and mill. However, the disadvantage is that it is easy to clog, and the suction fails. Today we are going to share how the porous CNC vacuum suction cup works, and why it is easy to clog. The adsorption of the vacuum suction cup is to use the vacuum drawn into the suction cup cavity, and the pressure difference between the inside and outside of the adsorption hole is formed, so as to adsorb the workpiece on the surface of the suction cup. There is an independent spring valve in each adsorption hole of the porous vacuum suction cup, the lower part of the valve core is connected to the negative pressure bin inside the suction cup, and the upper part is connected with the atmospheric pressure. According to the change of the interface between the internal and external pressure difference, the spring valve channel is closed and opened. When no workpiece is covered on the adsorption hole, look at the schematic diagram on the left side of the figure. When the suction cup switch is opened, a pressure difference will be quickly formed at the bonnet of the valve core, and the bonnet will be firmly pressed against the sealing ring, and the adsorption hole will be closed, and the suction force will not be felt when the hand is placed on the adsorption hole. That is to say, the adsorption hole will be automatically closed when there is no workpiece.
When there is a workpiece covering the adsorption hole, look at the schematic diagram on the right side in the figure. The workpiece is isolated from atmospheric pressure to a certain extent, and the atmospheric pressure can no longer be transmitted to the bonnet, nor can the bonnet be pressed down to the spring sealing ring, and the bonnet is in a state of being bounced up by the spring. In this case, the negative pressure is conducted to the lower surface of the workpiece. A pressure difference is formed between the upper and lower sides of the workpiece, and the workpiece is firmly adsorbed. But we need to pay attention to two objective facts. First, even if the workpiece is firmly adsorbed, part of the cutting fluid will still enter the inside of the valve core, due to the presence of viscous polymers in the cutting fluid, these viscous polymers will be attached to the spring, and the spring coefficient of the spring will change or even be stuck and completely invalid after a long time. The second is that the cutting debris or powder part that is smaller than the mesh of the filter will be stuck in the mesh of the filter, which will slowly weaken the air permeability of the filter and even temporarily block. It can also cause adsorption failure. These two reasons are the main reasons for the failure of adsorption of porous vacuum suction cups. Therefore, in the actual use of suction cups, we will find that ceramics, glass, quartz, glass fiber, graphite, bakelite and other materials of workpieces are more likely to plug holes in the drilling and milling process, and the porous vacuum suction cups bought at hand are thrown aside after a short time and are no longer used. This is mainly due to the fact that the vacuum suction cups of the spring-loaded spool are more likely to get stuck in the mesh of the filter with the same particle size as the powder when faced with powdery debris. This causes poor air permeability, and the powder is not easy to clean.
Is this kind of problem really helpless? In fact, if you take a look at an article I wrote, "An article teaches you how to do a good job in vacuum suction cup selection", you will find that not all porous vacuum suction cups will be plugged in the face of ceramics, glass, quartz, glass fiber, graphite, bakelite and other materials. It is a new type of porous vacuum suction cup developed based on non-spring spool technology, so that the powdery chips drilled out can no longer cause hole plugging and interference to the adsorption hole. Of course, in the face of conventional aluminum plates, copper plates, PTFE, stainless steel, and titanium alloys, it is even easier to deal with.