Punching specialists Kleiner GmbH in Pforzheim operate a large toolmaking shop for their own production activities and as a service to external customers. Thanks to their high vertical integration, they are capable of machining a wide range of components for high-quality punching tools. Wire-cutting on a Mitsubishi Electric MP1200 Connect has proved particularly effective. In unsupervised operations, the machine cuts almost all the functionally decisive components of a tool ready for installation from a single clamped plate.
Kleiner GmbH is one of several companies located in Pforzheim and environs, Germany’s heartland for punching equipment. The company has been established for many years as a high-quality and expert supplier to the automotive and electrical industries, primarily with precision parts made from steel, copper and aluminium sheet. The products include, for example, intricate plug connectors for electrical systems in motor vehicles, which are produced in large series of several million units annually. For this, Kleiner requires intricate punching tools, in most cases progressive dies with several integrated cutting and forming stages. The punching specialist in Pforzheim designs, makes and assembles these tools itself. For this purpose, it has a comprehensively equipped toolshop with currently about 60 employees. The company in Pforzheim covers the full range of services, from the optimisation of the punched components – usually in cooperation with its clients – and the design of the punching and forming tools to the production and assembly of the tools through to large-scale production on various automatic mechanical and hydraulic punching machines. Kleiner’s portfolio ranges from single-stage punching tools that produce high-precision micro-components with diameters of only a few tenths of a millimetre, executed on punching presses with 5 t press force, to complex connectors produced in large series on progressive dies up to 3000 mm long on automatic punching presses with 250 t press force. “This huge spectrum makes us the ideal supplier to the electrical, automotive and electronics industries. We have a comprehensive understanding of punching and forming processes, and our activities range from toolmaking to serial punching production operations. This makes us the perfect single-source supplier. In addition, we can also compensate for fluctuations in the economy. For example, we have been involved as experts in the development of electromobility right from the start,” explains Christian Hamann, authorised signatory and head of tooling at Kleiner.
For the toolmakers in Pforzheim, it is crucial to have and to be able to use all of today’s commonly used machining processes. “This is the only way we can act flexibly, produce tools within the shortest possible time, rework them if necessary and thus keep our series production up and running,” says Hamann. The machining techniques in Pforzheim include milling, HSC milling, turning, precision grinding, optical grinding, and die-sinking and wire-cutting EDM. ”With our own wire EDM system, we are not dependent on subcontractors. We always keep pace with the current state of the art with this latest technology as well. Which is why we invested in an MP1200 Connect wire EDM machine a few months ago,” Hamann continues.
He has been impressed by Mitsubishi Electric’s services in every respect: “In consultation with the sales manager Hans-Jürgen Pelzers, we were first given a machine to try out. Our employees were able to use it in everyday operations to get to know its special functions and superior features. We then took over the MP1200 Connect after a few weeks – what better proof of our employees’ enthusiasm for with the equipment and the way the MP1200 Connect works?”
In the opinion of Kevin Block, NC programmer and machine operator in toolmaking at Kleiner, wire cutting is highly beneficial to the production process, especially in toolmaking: “We can combine several machining operations. With the wire, we can fully cut complex geometries and shapes directly in a single production step. This machining process often even takes place unattended in evening and night shifts, eliminating the need for cumbersome, multiple machining operations – with HSC milling and subsequent grinding, for example,” he explains. This is why for the toolmakers in Pforzheim wire EDM usually proves more cost-effective and efficient than other machining processes. “Another advantage is that we can cut several components for a punching tool from a single plate and are thus able to produce many components of a tool in just one production run,” Block adds. For example, all the punches and dies for a progressive tool can be produced in a single process on the wire EDM machine. ”We also benefit here from the accuracy of the MP1200 Connect. This is because we can machine contours extremely reliably with accuracy of a few micrometres and achieve an Ra surface finish of less than 0.1 µm, enabling us to finish-machine the most common components for punching tools ready for installation,” says Block. The MP1200 Connect is ideally equipped with the standard SD-FS fine finishing generator for this purpose.
Block sees the machine’s reliability and its automatic wire threading as further key features of the MP1200 Connect. “We can program a large number of components for a process sequence on the wire EDM machine. In supervised shifts, the NC programmes are transferred to the machine, which we set up accordingly and load with plate. This is a quick and convenient process thanks to the excellent accessibility of the workspace.” The MP1200 Connect then machines the components unmanned. Block continues: “The automatic wire threading doesn’t let us down and works with almost unbelievable reliability. This makes it one of the best features of the MP1200 Connect. We can count on all the programmed components being cut overnight, for example, thus ensuring maximum flexibility for us. Time wasted due to waiting and time-consuming reworking is eliminated and the finished components are immediately ready for further processing or assembly.” At Kleiner in Pforzheim, NC programming for the entire toolshop is concentrated in one area. The NC programmers, says Hamann, benefit from the direct personal exchange of experience and the team’s accumulated expertise. For wire EDM, all work steps and cutting sequences are defined at the CAD/CAM system. The machine operator simply enters a few parameters on the machine and launches the production process. “The neat layout of the large touch screen with APP icons supports us and simplifies operation. This innovative type of operation is particularly helpful for the younger employees,” Block adds. The job scheduler that Mitsubishi Electric has integrated into the control system is also much appreciated: “This allows us to schedule different jobs for the night shift or weekend shift and plan how the MP1200 Connect is to work unattended.” Thanks to the reliable automatic wire threading, the toolmakers can be sure to have precision-machined components at the start of the next supervised work shift. To ensure that there is enough wire for the required long cuts, the MP1200 Connect in Pforzheim has an extra wire station for 20 kg wire spools. Block points out that the innovative drive system with Tubular Direct Drives and automatic collision monitoring on the MP1200 Connect also ensures dependable operation. “The risk of costly collisions with subsequent prolonged downtime and repairs, something that can always happen on wire EDM machines from other manufacturers, has been ruled out by Mitsubishi Electric,” he adds. He and Hamann agree that the MP1200 Connect from Mitsubishi Electric meets the needs of punching tool making to a tee.
Mitsubishi Electric’s wire EDM machines meet the exact requirements of the punching tool industry and come with an unbeatable price/performance ratio.
Hamann also stresses that he chose Mitsubishi Electric for economic reasons. In his view, the technical features of the MP1200 Connect are highly innovative, but rival machines also perform similarly well. However, the wire-cut EDM machines from Mitsubishi Electric prove to be significantly cheaper in terms of investment and operation. The price-performance ratio of the MP1200 Connect is unbeatable, Hamann confirms. He expects the machine in Pforzheim to pay for itself within a very short time.
Name and place of company:
250, with 60 producing
Toolmaking and punching, development and production of high-quality punching tools for the production of series components from steel, copper and aluminium sheet for external customers as well as for in-house production, punching of tiny and minute sheet metal parts, electrical contacts and connectors for electronics, and the electrical and automotive industries in large series
Göppinger Strasse 2-4
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