A Takumi Meister supports manufacturing by using reliable equipment to maintain high quality.
Takumi MeisterMakoto Yoshida
Skill: Finishing
Role: High Precision Lap
Shiwa Factory Production Department Engineering Section Maintenance Section
Technological innovations are remarkable in the field of manufacturing, such as AI, robots, and 3D printers. However, there are unknown areas that cannot be reached through technology alone.
This special feature focuses on the master craftsmen who continue to push the limits of precision and support Mitutoyo quality with their outstanding skills, and explores their skills and efforts to pass them on.
This time, we will introduce Makoto Yoshida, a master craftsman who maintains the factory's in-house production equipment and supports the manufacturing and high quality of Mitutoyo products.
Profile
Makoto Yoshida
Yoshida was born in Hiroshima Prefecture and joined Mitutoyo in 1978. He was assigned to the Quality Control Department of the Kawakaki Plant (formerly Mizonokuchi Plant), and was mainly engaged in finished product inspection work. In 1983, he was transferred to the manufacturing department and was involved in assembling measuring instruments, and was responsible for launching many new products and manufacturing high-precision in-house production equipment. Currently, he is mainly in charge of maintenance work at the Hiroshima office, where he has been certified as a "Hiroshima Meister" by Hiroshima Prefecture.
In-house production equipment for micrometers holds the key to sales
Finishing craftsman Makoto Yoshida's career began in 1978 at the Kawasaki Factory (formerly Mizonokuchi Factory). I was assigned to the quality control section, where I mainly inspected finished products, but I became interested in assembling measuring instruments, and after about five years, "I was transferred to the manufacturing section at my own request". He has been involved in the launch of numerous new products, including the digital hole test (HTD) and linear height gauge (LH600). Currently, he is mainly responsible for maintenance work such as repairing in-house equipment at the Hiroshima Office.
Mitutoyo has achieved a competitive advantage in precision by leveraging the skills of craftsmen in its high-precision in-house production equipment. Yoshida has contributed with his skills and technology. Yoshida also designed the in-house production equipment for manufacturing micrometers, which are produced in large numbers among Mitutoyo products and have a high share of sales.
Filled with the know-how of master craftsmen that is not available externally.
Yoshida worked on equipment (index machine) for drilling holes in micrometer frames. Up until then, indexing machines had an index table (rotary table) located in the center, but from an operational perspective, such as ease of work, a processing unit support was placed in the center, and a donut was placed around the outside. It has a type index table installed.
``We improved the machining accuracy of the holes for attaching parts that come into contact with the object to be measured, and thought about how we could achieve stable machining with little variation. The most difficult part was the accuracy of index positioning. However, we corrected the misalignment little by little. We also finished the parts by using scraping (*) to improve the flatness and perpendicularity of the parts.
Normally, index tables are purchased from outside sources, but Yoshida says that if you want precision, you can make them yourself. Mitutoyo's self-manufactured production equipment is packed with the know-how of craftsmen that is not available externally.
*Metal processing method that uses a chisel-like tool to finish the surface flat.
Craftsmanship applied to equipment repair
The reason Yoshida is a master craftsman is that he not only manufactures his own production equipment, but also his skill in reviving malfunctioning equipment and restoring high precision.
"When equipment malfunctions, we first conduct an equipment diagnosis. We look at frequently used parts and structures to identify weak points, and interview workers to determine the cause. Sometimes we may be wrong. It's a process of trial and error."
Using years of experience and intuition, we find faulty parts, replace parts, and make precision adjustments as the case requires. In order to achieve high accuracy, evaluation techniques that utilize measurement equipment with low error are also important. Our goal is to achieve as close to a complete restoration as possible. For this reason, Yoshida says, the important thing is to make ``correct measurements.''
The equipment malfunction suddenly occurred one day.
One day, the equipment used to manufacture micrometers suddenly malfunctioned. The equipment was not made in-house, but was a specialized machine made by an external manufacturer. The index table of this equipment suddenly stopped rotating. Workers surrounded the malfunctioning equipment and the scene was in turmoil. Since the equipment was responsible for an important process and there was no alternative equipment, it had to be restored in a short period of time.
``In order to find the cause in a short period of time, we needed to check the index part, but it was in a position that would require disassembly. When we disassembled it, we found that the motor of the index part rotates, but the rotation axis does not. Remove this word. To further investigate the cause, we disassembled the index component and discovered that rotation was not being transmitted due to wear on the biting part of the screw."
Yoshida contacted the manufacturer, but was told that the parts had been discontinued and could not be supplied, and that it would take two months to purchase new parts, so he was at a loss as to what to do.
Takumi's responsiveness
"The day after the failure, I realized that the axes of the screws were symmetrical. When I turned them around 180 degrees and reassembled them, the rotating shaft was activated, and I was able to make a temporary repair."
Disassembly and reassembly were carried out in three days, minimizing downtime. With this level of failure, Yoshida says, ``We were lucky that it only took three days.'' However, it was thanks to Takumi's unique perspective, calm handling and experience that ultimately minimized downtime dramatically.
They also cleaned parts of the car that could not be done without disassembling it, which made the improvements possible. This highlights Yoshida's impeccable response skills.
Achieving reliable inheritance through “standardization” of skills
Everyone recognizes the brilliance of Yoshida's maintenance work, but his transcendental skill in lapping three sides together is also worth mentioning.
``To ensure the precision of custom-made products, we perform finishing using three-sided rubbing lap. We rub the parts together to minimize both the heat effect and sensation of the hands during the wrapping process. During this process. it is important to have a good sense of how the hands are finishing while checking the seat (high place) of the part being fixed.
In fact, there is a story behind Yoshida's mastery of three-sided rubbing wrap. A person in charge of manufacturing a custom-made product with very high precision standards was retiring, so a successor was assigned to him for a year and taught him the technique of three-sided rubbing lap. However, he was unable to produce a product that passed the precision standards. This led to Yoshida being asked to produce this.
The project was undertaken in the absence of standardized materials and insufficient materials to serve as guidelines. It took about three months of trial and error, even for someone as skilled as Yoshida, to feel a solid response.
Based on the knowledge he gained from his experience over the past three months, Yoshida has been working on "standardization" from the perspective of skill inheritance and human resource development. In addition to the specific number of laps and finishing points, Mitutoyo also summarized the sensations of the hands in writing, which can sometimes be difficult to put into words. Instructions can be followed within the manual. In fact, the three-sided rubbing skill has been passed on smoothly, and two successors have completed inspection-passing products.
In the future, the successors will take on new initiatives to improve their own skills, such as pursuing high precision in three-sided lapping and shortening lead times.
Good relationship between craftsmen and successors
Yoshida is currently training two successors, and has built good relationships by valuing communication.
``Rather than having a hierarchical relationship, we try to work together to reach our goals. It is important to respect autonomy and encourage it, rather than telling people what to do from above.'' Communication is crucial to be able to work together. This includes asking any questions, and answering any if possible, when asked upon. Give advice where possible, and continue to support each other.
Yoshida's efforts to standardize the skills of craftsmen are a great accomplishment. When Yoshida was still young, there was no Takumi Meister system, and there were insufficient materials to guide his work. Through "standardization," skills and techniques can be passed on stably and highly accurate in-house production equipment can be maintained. It can be said that this is connected to the strength of Mitutoyo as a company.
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