„On a new level“

Weidmüller: Output of an innovative flat spring doubled

Large increases in demand volumes for an innovative flat spring persuaded the Weidmüller Group to transfer production, together with the associated manufacturing tools, from a GRM-NC to a new LM 2000-KT. This Bihler system, which has been specially designed for mass production operations, has doubled output to 500 parts per minute and has further improved the already impressive quality of the components.

Manufacturing some 6.9 billion parts per year, the Weidmüller Group is the world’s leading supplier of solutions for electronic connecting and automation technology. The company, which was founded in 1850, has a portfolio of approximately 60,000 different parts and components for these sectors. “60 percent of our metal parts are stamped and bended parts,” explains Wladimir Enns, Head of the Stamping/Bending department at Weidmüller. “These are characterized by their outstanding component quality, high production speeds and a high technical capacity utilization level.” Bihler, with which Weidmüller has been cooperating very successfully for decades, accounts for a significant proportion of this capacity. This all started back in 1971 with a RM 35, and the company now possesses a total of 77 Bihler systems. “The performance of the machines and their low downtimes are crucial. And if a replacement part is needed from time to time, then Bihler ensures fast, reliable provisioning,” explains Enns. Even though Weidmüller still has many older Bihler systems in its machine pool, the company places great emphasis on innovation for its future development and is also equipped with the most recent Bihler technology. One recent example is a GRM-NC, which has been in productive use since 2022 and for which there are now eight LEANTOOL.

Patented “SNAP IN” system

“The acquisition of Bihler’s servo technology and LEANTOOL system marked a sea change in our stamping-and-forming strategy,” explains Enns. It brought about a significant reduction in tool costs and minimized setup types. One of the products that Weidmüller manufactures on the Bihler GRM-NC using LEANTOOL tools is the “SNAP IN” spring – a spring element that is used in the innovative “SNAP IN” connector technology. Weidmüller uses this technology in its terminal strips as well as in other components. What makes this patented system so special is that it permits the automatic insertion of conductors thanks to the automatic release and engagement of pre-tensioned springs. No tools are needed to insert the wires and so the entire process can be performed automatically by robot. According to Enns, “the crucial factor is the high precision of the springs, which have tolerances down to a hundredth of a millimeter. “We can achieve this outstanding quality without difficulty at a speed of 250 strokes per minute on our GRM-NC.”

Perfect for mass production

The Weidmüller Group has now decided to go a step further in its manufacturing technology with a new LM 2000-KT. This innovative system will be taken into service in early 2024. The machine will take over production of the millions of “SNAP IN” springs that are now required due to the product’s huge market success. Enns: “With the new LM 2000-KT, we expect to see a considerable increase in throughput from the current 250 to a future 500 parts per minute. One vital factor for us is that we will be able to use many of the tools from the GRM-NC on the LM 2000-KT. At the same time, we expect the new LM 2000-KT to bring about a further improvement in the already high quality of these components by further increasing manufacturing precision.” And this expectation is fully justified because the system has been specifically designed to achieve such ambitions: “The machine frame of the LM 2000-KT is particularly rigid and robust, and the same is true of the fully lubricated machining unit slides and the twin-seated cams,” explains Kay Wesendrup, the Bihler Key Account Manager for the Connector Industry, who has been responsible for the Weidmüller project from the very beginning.

A real bonus – compatibility

Enns sums up as follows: “We are confident that we can successfully achieve further performance and quality improvements with the new LM 2000-KT. It is the optimum solution for the efficient, high-quality production of components, while simultaneously increasing output from small to mid-sized runs and right through to very large parts volumes. Another bonus for us is the compatibility between the two systems: We can switch our tools from the LM 2000-KT back to the GRM-NC at any time, giving us extra flexibility.”