Servo Press Installs Bearings in Wheel Assemblies
Since 1985, Staufermatic Maschinenbau GmbH has made a name for itself worldwide in two specialties. One is designing and manufacturing special-purpose machinery for assembly, riveting, drilling, leak testing, safety and press-fitting. Another is developing and building assembly plants, primarily for the automotive industry.
In early 2017, Staufermatic finished building a new plant for a German manufacturer of wheel carriers, which keep the front wheels on the car steady and allow drivers to safely change direction. According to Holger Zilian, managing director at Staufermatic, the plant took about a year to build, and its production lines feature equipment that ensure 100-percent quality control and traceability through each assembly process.
On one line are four workstations where rubber bearings are press-fit into the wheel carriers. At three of the stations, a NCFN joining module from Kistler Instrument Corp. press-fits the bearings, and a Kistler maXYmos NC system monitors, evaluates and documents all X-Y characteristics of the process.
“Press-fitting the bearings involves fixed dimensions, so maximum precision is required,” explains Zilian. “This cannot be achieved with conventional hydraulic systems. MaXYmos guarantees 100 percent quality because force-displacement monitoring is used to measure and evaluate every part that passes through the process.”
Zilian says that Staufermatic selected Kistler’s joining module and monitoring system because of past success using the products. He also likes that maXYmos allows free programming and simple integration of multiple assembly units, and enabled mechanical engineers to easily meet the OEM’s requirements for assembly line volume, part quality, footprint and budget.
During bearing press-fitting, the maXYmos system sends real-time data (force-displacement, torque-angle, pressure-time, and other process variables) to the OEM’s master computer. The data is displayed as an X-Y curve on a color touch screen, and indicates whether a part is good or bad. Each lot is identified by a Data Matrix code, ensuring accurate and immediate documentation for traceability.
“Our end-to-end process monitoring guarantees consistent traceability, which is a fundamental prerequisite for Industry 4.0,” says Zilian. “Enhanced flexibility [is also] extremely important in the automotive industry. The result is that our customer saves time and money on production. Both factors are critical to market success in the future.”
The maXYmos comes in NC, TL and BL versions. MaXYmos NC is used with NC joining modules, and its motor is controlled by the servo amplifier IndraDrive. This drive features a power section with firmware, a parameter set, a safety zone box and all cables.
Both the TL and BL systems feature a sequencer mode that verifies the quality of a production step, a multistage production process, a subassembly or an entire product. The mode optimizes cycle time, maximizes repeat accuracy, minimizes downtime and increases machine availability. All three versions enable early detection of quality variations in the production process. They also feature programs that set up quickly, and integrated sequence control so complex test processes can be mapped without external PLC programming. The model TL also has evaluation objects that support additional applications such as switch testing.
For more information on joining modules and X-Y monitoring systems, call 248-668-6900 or visit www.kistler.com.