DESIGN OF ORIENTATION SYSTEM FOR FEEDING OF POLYGONAL PARTS USING FENCES

Abstract

Automated assembly is an essential manufacturing operation in mass production in many industries. All the assembly operations are carried out in a sequence of workstations along an assembly line. For automated assembly operation, parts are to be fed in acceptable orientation for assembly. This is achieved by using part feeders along with orientation system. A feeding system is the integration of different hardware equipments, such as hopper, parts feeder and part orientation devices. Parts feeders can generally be classified into the following classes: vibratory feeders, reciprocating feeders, disk feeders, belt feeders and flexible feeders. In this dissertation work, the design of orientation system for polygonal parts on conveyor is addressed. Polygonal parts are needed in many of the assemblies. The polygonal parts need to have certain orientation for assembly, which are generally fed to the assembly on a conveyor belt. Parts are oriented using fences on the conveyor belt. These fences are arranged at different angles on either side of the conveyor belt. The incoming parts on the conveyor may be in any random orientation, but after passing through all the fences, parts must be in a unique final orientation. In this work, an algorithm for calculating the fence angles is adopted and modified to -consider the friction between parts and fences. Fence angles have been determined based on the polygonal part geometry. The algorithm for calculating fence angles has been programmed in MATLAB. Coordinates of the vertices of the part are given as input to the program to obtain the angles of the fences with respect to the conveyor belt. When the friction is neglected in the fence angle determination, due to friction parts may not slide along the fences, which are too steeply oriented. To make the fence design more realistic, in this work, fence angles are calculated while considering friction between parts and fences. In addition to determining the fence angles, orientation system is designed for feeding polygonal parts. The design includes the calculation of the velocity of the conveyor belt for the given part feed rate. Based on the size of the parts, lengths of the fences, width of the conveyor has been calculated. Two sample studies are presented that includes a pentagonal part and a triangular part. For the pentagonal part considered, three random orientations of the part were considered to show that the fmal orientation of the part is same in all three cases. Graphical representation of the part orientation system, while parts moving through fences in three cases, were shown for better illustration.