Edge grinding process and edge checking control for screw cutter
In envelope process of cutter, profile and tool-path of cutter are complicated, and the grinding depth is variable which causes grinding force to change on a large scale and the error of edge envelope to increase. To improve cutter accuracy, the theoretical model of cutter edge and theoretical tool-path of CNC tool grinder were calculated. Closed-loop control system was designed to accomplish control of envelope process. By adjusting feed-rate, constant force grinding process is accomplished to improve the precision of edge. The methods of edge design, tool-path calculation and manufacture processing of cutter on CNC tool grinder were discussed. Machining test indicates that cutter error is 8~11μm, and coherence error of sample thickness is reduced to only 3μm, by constant force grinding.
Fuzzy Control in Profile Envelope Process of Form Cutter for Involute Gear and its Movement Control
In profile envelope process of form cutter for involute gear, the grinding depth is variable which causes grinding force to change on a large scale and the profile error of envelope to increase. To improve form cutter accuracy, a closed-loop control system was designed to accomplish control of envelope process. For complicated dynamic process, fuzzy controller is used to adjust parameters online. By measuring grinding force, characteristic information of grinding process is acquired. Regulation factor of feed rate is determined by grinding force ratio, force deviation and its change rate used as evaluation indexes. Thus, fuzzy control of constant force grinding process is accomplished. Simulation and cutter grinding test indicates that the system has high precision and stability, and reduces cutter error effectively.
Economics of General-Purpose Assembly Robots
Summary A study of the comparative economics of various automatic assembly systems using general-purpose assembly robots is described. In the study, use is made of a “typical” candidate assembly whose profile is obtained from statistical analysis of actual products submitted by interested companies. It is shown that the choice of assembly system and the various parts presentation methods depends on three main factors, namely: the annual production volume per shift, the number of parts in the product and the equipment payback period.