Expertise produces optimal feeding systems
The feedability analysis and its influencing factors
Smartphones, cars or computers: product life cycles are getting shorter and shorter. Despite this, every new product still requires appropriate production equipment, which in turn, also needs to be planned and realised all the more quickly, as in the case of assembly systems which include feeding technology. A great deal of information and many parameters must be taken into consideration in order to achieve an optimal result in the interaction of the various components for smooth processing. Their many years of experience, ingenuity and the rapid availability of their standardised modules mean that DEPRAG SCHULZ GMBH is a global player in the market of feeding technology. Thomas Lederer, Application Specialist for Screwdriving Technology and Automation at DEPRAG has answered some questions on this topic in order to explain the various backgrounds and contexts for the feedability of fasteners and optimal design.
Interviewer: Supply of fasteners, such as screws, via a feed hose is the preferred method of feeding, because it currently offers the best processing reliability and the shortest cycle times. Whether feeding via feed hose is actually possible, is decided by the experts at DEPRAG after a feedability analysis. How does such an analysis take all eventualities into consideration?
Lederer: The central question is whether automatic feeding of the screws via a feed hose is possible and if not, is it possible to make a simple change to the screw geometry to allow feeding via a feed hose? An approximation formula is one option used to test feedability via a feed hose (see image 1). This is the initial step in determining feedability. In the formula, the relation between the screw length to the screw head diameter is determined and from this, the probable angle of a fastener’s slanted position in the feed hose can be calculated. If the resultant angle is marginal, our specialists come into play. Using a dimension sheet of the screw, it is possible to determine the exact slanted angle of the screw in the feed hose using CAD software. Nevertheless, even with a negative result, feedability can often still be achieved through small changes to the screw geometry, such as the reduction of the head diameter or an increase in the screw shaft length. If making alterations to the dimensions of the screw is not an option, the Pick-and-Place procedure is the best choice. This feeding technology moves the fastener to a clearly defined position, allowing the screwdriving tool to target and pick up the fastener using vacuum, magnetism or a gripper device. Pick-and-Place feeding technology can also be used to supply other components, such as O-rings or labels.
