"SMART ASSEMBLY" - The ability to do work and verify the result at the same time.
Assembly of precision parts with tight tolerances has always been challenging for several reasons;
1. Assembly requires precise variable control of press/pull forces and positioning. More and more tolerances are moving to lower than 10 gram/micron range.
2. Open loop assembly has always been considered unacceptable hence the wide spread development of a variety of sensors that can check success or failure of an operation. But the application of these sensors is not easy and most often a secondary check - since they are integrated into the actuator actually performing the work.
SMAC Corporation has had major success applying its “SMART ASSEMBLY” technology at major consumer products manufacturers around the world as well as in automotive and packaging applications. SMAC’s Moving Coil Actuators can programmable control force, velocity, and position AND can feed back in real time the success of the operation in terms of force applied and position achieved. It can even detect and decide if precise final adjustment is required and then do this.
Here is a video example showing a 2 piece assembly using a SMAC Moving Coil Actuator.
Great success has been reported by many high volume makers of precision products. A cell phone manufacturer was able to reduce a 30% scrap rate of a key component made of of 8 less in parts to less than 2 %. This was by replacing pneumatic slides with SMAC LCA 50 actuators. The 30 % scrap was caused basically by a combination of overly high press forces and imprecise press in position. That was eliminated by the SMAC device. The remaining scrap was caused by out of spec parts and the SMAC device can recognize this failure in real time as well.
Another interesting application is in precision wire welding used in air bags. Here both pneumatic cylinders and electric ball screw actuators caused problems. The former due to lack of precise force control and high impact force. The latter due to the fact the the wire position moves as heat is applied and thus contact force drops since the ball screw can not quickly adapt to this change
SMAC’s MCA, with its patented “Softland” ability and programmable force combined with real time feedback of change of position (the shaft tracks the wire movement due to heat) has resulted in nearly 100% perfect welds and also the ability to detect failure.
Use of SMAC’s SMART ASSEMBLY technology has enabled several large pneumatic valve manufactures to not only make near perfect assembly of precision valves but also to reduce tolerance stack-ups bad “Center” the stack-up so that valves are not assembled and shipped on the edge of the stack-up. This greater reduces premature field failure.