Some Considerations in Parts Feeding for Automated Equipment
The first operational step in any type of automated assembly, inspection, or processing machine is feeding the parts under consideration into that machine. Many different types of loading options exist, each with its own merits and drawbacks that make it more or less suited to a given part and cycle time. In this post we’ll take a look at some of the more common options for automatic parts loading.
Vibratory bowl feeding is generally the first thing that comes to mind when people think of automated parts feeding and is generally regarded of as the best ROI in terms of the end result, the cost of the system, and the human effort required to load the system. When the application is right this is a great method of automatically loading parts but is does have its limitations. Part geometry and material can make this method difficult if not impossible. Part finish can be marred, disfigured, or otherwise damaged as a result of tumbling inside the bowl. Complex parts can also increase the likelihood of bowl feeder jamming.
Rotational magazine loading is an attractive method when parts cannot be adequately handled by a bowl feeder due to geometry or damage concerns. In theory this method allows total uptime of the machine provided the empty magazines are refilled in a timely manner. The drawback here is that the parts are generally loaded by hand so consideration must be made regarding the throughput of the machine and the time required to fully load the magazine.
Automated tray picking is generally used when maintaining the surface finish and appearance of the part is of the utmost concern or with very complex parts that cannot be stacked in a rotational magazine. This method either requires a sizable footprint for the parts tray staging or a method of automatically replacing empty parts trays with full ones. Empty trays can also be replaced manually. A pick/place robot for handling the parts is employed here so depending on the part and tray geometry the system can sometimes be complex.
Infeed conveyors can be used for very long, large, or otherwise ungainly parts. These systems ensure proper part singulation and orientation but can take up a large footprint and still require manual loading of the parts on the conveyor.
Recirculating conveyors with vision guided pick/place robots are great for fully automatic high throughput of complex parts that cannot be bowl fed. In the system shown to the right a hopper feeds a conveyor with a vision guided pick/place robot located at its end. Any parts not selected by the robot are recirculated back into the main hopper to be presented again. Like bowl feeders these systems require minimal human handling but can have a sizable footprint.
It is plain to see that many options exist for how a part will be loaded into an automated machine with each of these methods having its pros and cons. We’ll take a closer look at each of these methods in future posts.