Automotive OEMs and Tier 1s are increasingly separating specific assembly processes from the main production line as part of their lean manufacturing model. This approach often reduces waste and production costs for the individual process, while maximizing overall production efficiency.

In late 2013, Weidplas (formerly Weidmann Plastics Technology AG) implemented lean manufacturing at its Treuen, Germany, plant as a way to produce mechanical assemblies with zero defects. Weidplas is a worldwide Tier 1 automotive supplier of plastic components.

For many years, Weidplas assembled and tested various types of mechanical assemblies on its main production line. With its implementation of lean manufacturing, however, the company decided to pull these two processes off the main line and perform them at a manual workstation.

Flexible Montagetechnik GmbH (FMT), a distributor of Bosch Rexroth framing, developed the workstation over a five-month period in conjunction with the Kistler Group. Collaboration between the two companies has taken place since 2008, especially for projects that require process monitoring.

The workstation features an integrated
Kistler maXYmos BL force-displacement measuring system for quality assurance. To increase productivity, workstation height can be quickly adjusted so the worker easily reaches all tools and bins.

One type of mechanical assembly built and tested at the workstation is an air damper control unit. It consists of eight components that are inserted one after the other into an error-proof fixture. One component, a splint, is then pressed into place.

To ensure proper splint installation, the measuring system captures the X-Y (force-displacement) data from the pressing process, converts it into a graph, and compares it with the press target limits set by Weidplas.

If the press value is within target limits, a green box is displayed on the system monitor to indicate pass. If the value is outside the limits, red is displayed to indicate fail. This color coding enables
workers to remove faulty parts from production at an early stage, ensuring consistent product quality and zero defects.

At any time, users can immediately access the system’s curve history database. The system also features a fieldbus interface for exchanging signals, and an Ethernet interface for fast data export and remote maintenance. Profibus DP or EtherNet/IP protocols are optional.

 For more information on force-displacement measuring systems, call 248-668-6900 or visit www.kistler.com.