Riken Forge slash manufacturing times by over 80% with WorkNC

Riken Forge, was founded in 1938 and has its headquarters in Maebashi, Gunma Prefecture, Japan. Producing high quality hot forgings for the automotive, agricultural and construction industries, the company was already very successful with a turnover of over 10 billion yen (Euro 64M), however it was seeking ways to expand its global market.

<< A set of dies used to take a week, this is now down to two days with WorkNC. >>
Hiroki Takama, Production Engineering Department, Riken Forge.

In a bid to become even more competitive in the manufacture of dies, the company initiated a project to machine hard materials directly, thereby eliminating the use of electrodes and hand polishing.

When Riken Forge evaluated new CAM systems in 2002, compatibility with its CAD software was a key consideration. Hiroki Takama from the company’s Production Engineering Department said, “WorkNC was the only system capable of opening our JAMA-IS format CAD files. It was also obvious that WorkNC was better for direct machining of dies, producing high quality NC data with customized templates – it was going to be an improvement in every way.”

Before the deployment of WorkNC, Riken Forge created toolpaths manually. Using WorkNC, die sets can now be manufactured in as little as one quarter of the previous time. Hiroki Takama, added, “It used to take two days to create NC data for one crankshaft and we often received complaints from the shop floor. Now it only takes half a day. Similarly, a set of dies used to take a week, this is now down to two days with WorkNC.”

Improving quality and reducing cycle times are at the heart of Riken Forge’s ‘innovative manufacturing’ programme. WorkNC’s finishing toolpaths, Z-Level Finishing, Optimized Z-Level Finishing and Contour Re-machining have enabled longer tools - with a length to diameter ratio of up to 10 – to be used reliably. Meanwhile, compared with the copy milling process it used previously, cycle times have been cut by over half, from 58 hours to 26.4 hours for a core and cavity. Surface finish is also improved, from 25μ in 3.5 hours to 11μ in two hours. The shortened cycle times have of course also increased tool life, making a further contribution to overall cost savings.

WorkNC’s High Torque Roughing has enabled Riken Forge to take full advantage of high speed machining for direct machining of the die. By using small depths of cut, tool load and cycle time are minimized, saving 62% of roughing time. Direct machining of the die has also eliminated EDM operations. The result is an impressive 82% reduction in the manufacturing time for a trimming die. Previously this could only be produced by EDM due to the hard stellite material used in the die’s cutting edge. Hiroki Takama, said, “Producing a part with multiple Z levels using EDM is generally a lengthy process, sometimes taking as long as 60 hours. We also encountered problems with misalignment during the EDM process and the machining of the copper electrodes.”

Hiroki Takama continued, “WorkNC has made it much easier to create CNC data. WorkNC’s machining sequence saves us a substantial number of man-hours. What’s more it creates the toolpath quickly, with a choice of re-machining paths, enabling us to improve the quality of our products. We are particularly satisfied with WorkNC’s Remachining toolpath.”

Saori Sekine from the Production Engineering Department, added, “A Z-Level Finishing toolpath is required to finish some dies. However we find that WorkNC’s 3D Drive Curve Finishing toolpath works much better for these parts. It eliminates unnecessary retracts and provides a smoother finish by machining on the surface with a constant stepover. A toolpath can be created without subsequent modification so we can leave WorkNC to calculate in batch mode overnight. When the toolpath is ready for machining the next morning, we do not even need to check the data. This is a huge advantage for us.” Riken Forge also takes full advantage of WorkNC’s customized documentation and tool holder collision checking. The software calculates the minimum tool length, ensuring that the most suitable tools are used, which in turn cuts machining times, and eliminates errors.

Mr. Shindo, the Production Engineering Department’s General Manager explained, “This year our company’s goal is to obtain even higher product quality and zero complaints. The annual turnover was 10 billion yen (Euro 64M) in 2005, and our goal for 2006 is 11 billion yen (Euro 70.5M). For die manufacture, we intend to further develop the technique of direct machining without hand polishing. We also plan to reduce the production costs for die manufacturing by 20%, and continue our investment in new equipment, which reached 800 million yen (over Euro 5M) last year.”

WorkNC is a valuable tool for Riken Forge, helping it achieve its aims of faster production and cost reduction through continual development and full deployment of the software’s powerful capabilities.