Founder's Thoughts: Various Measurements
Now, what is measurement?
To put it simply, it is said to be the quantification and evaluation of physical phenomena. Today, saying 'It's cold, isn't it?' does not constitute measurement. Only when we convert it to a number, like 'It's 15 degrees, so it's cold,' does it become a measurement.
However, while measuring instruments easily display numbers, determining whether they truly represent the desired data is a challenging task. Let's consider the thermometer, which is a popular tool for temperature measurement. Even within the same room, the temperature can vary depending on the measurement location. This means that even in a calm laboratory, it can be unclear which reading should be considered the room temperature.
Additionally, if we attempt to conduct engine experiments in that environment, the engine generates heat and consumes a large amount of air, causing air of different temperatures from outside to intrude. This affects engine performance, and the intake temperature changes randomly, making it impossible to measure temperature accurately, ultimately leading to a situation where the engine cannot be analyzed.
When Professor Shuhei Izumi, who moved from Mitsubishi Heavy Industries to Nagasaki University, established the Thermal Fluid Research Laboratory at the university, he set up a massive experimental facility where cooling water, fuel oil, and intake temperature were all controlled with an accuracy of less than 0.5 °C and intake pressure was less than 5 mm of water column. At first, I wondered why such equipment was necessary, but to accurately grasp the reality of combustion and engine performance, it is essential to thoroughly prepare the initial conditions, which requires a large air chamber, fuel oil tank, and cooling water tank for supply. Furthermore, at that time, we also ordered engine and dynamometer experimental equipment centered around a digital torque meter, as well as an acoustic intensity meter and acoustic analysis equipment.
By forcibly controlling those temperatures, Professor Izumi developed a combustion analysis device capable of accurately drawing pressure line diagrams, which can be considered the foundation of combustion analysis, contributing to the understanding of combustion reality. Additionally, he enabled the simultaneous online measurement and analysis of vibration noise at eight points, allowing for the analysis of changes in fuel quality, intake temperature, and cooling water temperature without using an anechoic chamber, ahead of the world.
By the way, our Utsunomiya factory has a temperature-controlled factory for precision machining. This is a story from quite a while ago, but on Mondays and Tuesdays, we suffered from the so-called Monday sickness, where many defective products were produced. Upon investigating the cause, it seemed that the temperature controller in the temperature-controlled room had been turned off on Saturdays and Sundays. The problem lies here. The air temperature inside the temperature-controlled room is said to stabilize in a matter of minutes. However, the temperature of the working materials and machines in the factory takes at least several days to stabilize. If the temperature is unstable, precision machining cannot be achieved. This is what resulted in the defective products. No matter how much we try to save electricity, we cannot turn off the power to the temperature control.
I have had a bitter experience as well. I needed the temperature function of the transverse elasticity coefficient of the torsion bar material used in torque meters, and I was measuring it inside the temperature-controlled room. However, it just wouldn't align with the expected straight line. The conclusion was that I couldn't wait long enough for the material's temperature to stabilize. In other words, it took a full day to measure a single point before it finally aligned with the curve.
Therefore, if torque meters require a level of precision where the temperature coefficient of the material becomes an issue, we have no choice but to select materials whose transverse elasticity coefficient does not change with temperature. This is because we cannot keep the temperature of the torsion bar constant. Even with work in a temperature-controlled room, it is in such a state. This illustrates how difficult it is to estimate the temperature of materials in a normal indoor environment.
From the above examples of temperature measurement, you can understand how difficult it is to know the actual temperature, no matter how much we improve the accuracy of the thermometer.
I think of myself not so much as an engineer, but as a true craftsman. The knowledge of a craftsman is not entirely something that is accumulated from reading books or being taught by seniors. Most of it comes from observing others' gaps, stealing experiences, and learning techniques through deep contemplation.
Recently, there have been many stories on television about living national treasures and those who have made significant contributions to their craft. These stories often bloom into nostalgic tales about my father, who was also my master. The content usually revolves around phrases like "my father never taught me anything" or stories about how he would silently crush my work when I brought it to him for critique. In the end, the son learns the craft by stealing the father's silhouette and mannerisms, thinking for himself and adding his own ingenuity. However, it was not through direct teaching; rather, this self-thought and ingenuity lead to the next originality, pioneering new techniques, and becoming a driving force that surpasses the father or master.
On the other hand, the skills that my father completed by stealing and learning were difficult to develop into a systematic theory on his own, so perhaps he genuinely could not teach.
I started with post-war electronic tube counters and supplied what we now call digital instruments to the machinery industry. At that time, Nissan asked me to commercialize this combustion analyzer, presenting me with a paper by Professor Daito, who was then at Osaka City University. After reading that wonderful paper, I promptly went to Osaka to obtain permission to start making it. That was my first encounter with Professor Daito. At that time, I also explained the content of Ono Sokki's products, particularly the torque meter I had just begun researching, and mentioned my struggles with the theoretical basis, where the main factors appeared in both the numerator and denominator and were canceled out.
After a while, he suddenly visited Ono Sokki in Tokyo and offered to help finalize the torque meter paper to present at the S.A.E conference in Detroit. I was surprised, but together with the professor, we spent several days at the Ono Sokki resort in Utsunomiya, and finally completed the theoretical framework and the paper.
I remember being deeply impressed by how the theoretical basis was developed in this way.
Later, Professor Daito and I received notification from S.A.E that our paper would be accepted, and at the end of Showa 39, during a time when acquiring foreign currency was difficult, I set out on a trip around Europe and America with a limit of 500 dollars. Even in an era when 1 dollar was 360 yen, traveling for two months on 500 dollars was truly a poor man's journey, where I couldn't afford to eat or drink with my own money, but I was able to successfully present the paper.
This torque meter became my life’s work and led to my degree at Kyoto University, the Purple Ribbon Medal, and many other awards. This is entirely thanks to the professor, who was also a benefactor that guided me from being a craftsman to an engineer.