The Mitsubishi Electric Shinshiro factory in Japan has manufactured motors since 1974, but model customisation makes production complex and lengthy. Since manufacturing digitalisation of their processes, customers can choose from 40,000 models available in a five-day delivery window. For those prepared to wait 15 days, the permutations increase to 2.3 billion, covering most customer needs.
According to General Manager Hiroyuki Akita, “to deliver a wide variety of products in a short period of time, our target was to tackle the long manufacturing lead time. We focused on how we handle the entire production schedule and how we could shorten each process, from the manufacturing of parts and products to the shipment of these products. To achieve this, we leveraged e-F@ctory to synchronise our complex manufacturing digitalisation processes.”
One of the key variations in motor specification is the electromagnetic performance, which affects the characteristics of the motor. They match the customer’s performance needs by varying the density of the coil windings around its iron core.
The new manufacturing process allowed them to increase productivity by reducing the time needed for complex procedures. For example, the set-up for the winding process and the winding process itself. The winding process is a mixed line where automation and manual work co-exist. The production management system gathers “work time” from both the automated machines and from the operator for each process.
Manufacturing digitalisation
Explained Noboru Shirakura, Senior Manager in charge of Manufacturing Engineering. “We wanted to determine where each process began and ended to measure the work time. Each worker’s main movements are lifting the tool and returning it, so we measured it by attaching sensors to the tool holder.”
Another key factor for a motor’s specification is the shaft that rotates inside the motor. Each shaft is customised according to motor use, and it takes time to adjust the shaft line production unit by unit. Their competitive advantage relies on the automation of the shaft machining and reducing this processing time.
Noboru Shirakura added, “The bottleneck in the shaft line was the final grinding process. We wanted to shorten this process. So we replaced part of it with turning in the preceding process. To reduce the machining performed by the grinder, the e-F@ctory process feeds real-time data from the grinder to the NC lathe to stabilise the machining accuracy.”
E-F@ctory
Factory engineers are now considering new ways to use the data collected by the e-F@ctory manufacturing digitalisation system. Chiefly, they are trying to optimise tool wear in machining equipment to help manage tool life and improve efficiency.
e-F@ctory is Mitsubishi Electric’s integrated concept to build reliable and flexible manufacturing systems. It enables users to achieve many of their high speed, information driven manufacturing aspirations.
Noboru Shirakura explained. “In the past, we set tool life spans based on our experiences. The tool wear diagnosis system automatically collects date to determine the optimal wear value, or tool life. We should be able to use tools for a longer period than before. Furthermore, this will help us reduce tool costs and reduce changeover times.”
Equally important, linking e-F@ctory to open software platform “Edgecross” allows data collected from machines of different brands or even older machine tools. This also helps them visualise machine tool data and improve productivity sooner and at a lower cost.
“The three-phase motor is a mature product, so to be competitive in the market we need a wide line up and short delivery time. Without e-F@ctory, we would not be able to provide products in such a short delivery time,” Hiroyuki Akita concluded. “By utilising data for production, we now see new opportunities to create new services in this mature market. Moreover, there is no end to making improvements in manufacturing digitalisation. And there is no end to business development.”
