MMC Magazine

Delivering High Productivity and Advanced Automation That Improves Product Quality

Cutting-edge technology is essential in producing solutions to the wide range of problems that society encounters over time. Automation and manpower saving in particular will be key factors at production sites in the future. The Gifu Plant succeeded in establishing a model line capable of long-term unmanned production. We interviewed the General Manager, Nariyoshi Fukushima about frontline approaches and future targets at the Gifu Plant.

Beginning with manual machinery, solid drill production has now evolved into a sophisticated cutting-edge technology requiring no specific location or manpower

Automation aiming to improve all factors

When I joined Mitsubishi Materials and began working at the Gifu Plant in 1989, brazed-type drills were the main trend and solid drills were still under development. Most of the manufacturing processes at the plant were performed by manual machinery. For 10 to 20 years, we focused on facility investment to increase production and expand product lines. Now, solid drills have become the major product manufactured at the plant.

When the advanced automated model line project started in 2018, solid drills were the goal. The Production Technology Dept. was assigned to the project with the task of achieving improvements in manpower saving, productivity and process capabilities. Although the department was manned by a small staff, the members were highly capable.

I personally feel that three out of four major technologies - automatic measurement, automatic set-up change and automatic transfer - have already been established. Operations that had interrupted long-term continuous machining during the grinding and the sharpening processes were optimized through the introduction of unmanned operations. The only exception to this was operations required for quality assurance. This led to even greater quality stability than we had expected. What we developed at the Gifu Plant was a broadly applicable technology that could be used at any location by anyone. Therefore, we are thinking about expanding the system not only inside Japan, but also to overseas bases.

What we need to focus on now is the effective utilization of data to achieve smart operations. We have visualized the whole operation and work rates, and we are now evaluating the best way to analyse data and prevent problems. We have also started work on advanced automation lines for small-diameter solid drills, CBN tools and metal products. Another task is to prepare supervisors for future overseas expansion.

In FY2023, the Gifu Plant celebrates its 50th anniversary. I am extremely impressed with the progress that has been made over the past 30 years or so, outstanding results that were achieved through the tireless commitment of the skilled people at the Gifu Plant. We are now setting our sights on achieving our next goal, drastically improving the rate of automation at the Gifu Plant by 2030.

In-house development of the advanced NC program

For our automatic measurement system, sensors and CCD cameras are incorporated inside machinery to send data for automatic adjustment of the next tool. There were many problems to be resolved and we needed to determine the range away from median value for adjustment, and we needed to strategize our response to failed measurements. However, although we were extremely busy, we didn’t want to outsource the work because we had strived for years to build know-how, and therefore wanted to handle it ourselves. We engaged in trial and error for about a year to develop a program to establish median value adjustment technology for size. For our automatic set-up change, an NC-controlled rest is incorporated into the grinding machine. Applying our accumulated know-how to development made automation relatively smooth.

Product lines combining multiple robots

For automatic transfer, we established an integrated system that manages the schedules for different machines by providing instructions to a palette with RFID (radio frequency identification) that has a non-contact telecommunication function. Utilizing fixed-type 6-axis robot arms connecting the AMR (autonomous mobile robot) and machines achieved automatic transfer of work material between processes. We resolved issues regarding wireless telecommunication and control methods and battery life before beginning full operation in the summer of 2021. Even after that, we continued working to improve the system. In FY2022, we developed an unmanned product line that could operate for an extended period by replacing a 2-axis conveyor on the AMR with 6-axis robot arms that have a higher degree of freedom of motion.

Achieving unified cloud management

We also developed a unified cloud management system for data collected from machining devices, and we are trying the establish a learning system to the machine that uses data to predict how environmental changes will influence machining results as we promote our smart factory project. Currently, automation is only applied to the grinding and honing processes. We would like to apply the advance automation system to a broad range of machining processes and establish a product line that can unitarily manage productivity improvement, budget control for production, quality improvement and predictive maintenance via the cloud.