Overview:

The orbital riveter is a semi-automatic assembly station.  The station is based on a standard lean assembly station that has been upgraded with a simple PLC control system and a simple pneumatic mechanism.

Process Description:

Assemblies are loaded onto the assembly mandrel. A pneumatic clamp closes to lock the assembly in place.  While the clamp is closing, the Y-Axis slide retracts to bring the first pin under the orbtiformer.

With the nest in place, the X and Y axis slides are pneumatically locked to minimize vibration. The orbitforming head begins to rotate, and then descends and the peen contacts the pin.  The combination of pressure and rolling motion schmooshes the pin material outwards, creating the head.

When the first head is formed, the orbitformer retracts, the locks are released, and the pneumatic slide moves to the second position. The locks are then engaged, the process repeats to form the second head.  When the process is complete, the locks are released, and the stage moves to the load position.

Technical Challenge:

One has to be concerned with vibration during the orbitforming process. The rotation of the orbitformer and the lateral forces exerted by the peen can cause vibration.  This vibration may just be annoying, or it may cause the part to wobble relative to the peen, and lead to quality problems.

In this case, due to the lean nature of the solution, we opted for the smallest head that could form the peen, and made sure that the entire mechanism was rigidly tied together through the tooling plates.  We also locked the pneumatic slides to ensure that they didn't act like springs, allowing some small movement of the workpiece.