The most important concept of manufacturing is precision. There are two concepts in it, one is machining accuracy and the other is measuring accuracy.
How to reflect the size that the designer is hoping for is the machining accuracy, and how to know the size of the machining is the measurement accuracy. Both of these precisions are directly dependent on the accuracy of the machining machine or the working machine of the measuring machine. The machining accuracy of mechanical equipment will only be lost without increasing. The 1/100 mm precision machine can only process workpieces with an error of 1/100 mm or more, so even if the assembly error is not considered, the medium machining accuracy is used. Machines assembled with machined parts can only reach lower precision. To consume parts assembled into medium-precision machines, only high-precision machining machines can be used.
According to this principle, to manufacture high-precision machining machines, only ultra-high-precision machining machines can be used. This raises a question: how the so-called "ultra-precision machining machinery" is manufactured and manufactured. The answer may be unpredictable. "Ultra-precision machining machines" are made by hand. When it comes to "precision", it is reminiscent of the technical terms of "computer" and "digital". In theory, precision has nothing to do with those fashionable terms. Before those fashionable terms were presented, humans could have reached high precision. It is. The most important influence on the precision of the machining machine is the rail portion. The moving part of the machine is limited by the guide rail, and the accuracy of the guide rail directly determines the accuracy of the mechanical movement. The sliding surface of the ultra-precision mechanical guide is called "absolute plane" and requires an accuracy of 1/10000 mm or more. Now there is no mechanical machine capable of processing such an absolute plane, which can only be processed by hand.
Anyone who has seen the sliding surface of a high-precision machine tool guide knows that the so-called "absolute plane" is not a smooth mirror, but a plane that has a regular pattern, and those patterns are the blades of the craftsman who made this plane. Traces underneath.
The absolute plane manufacturing process is like this: Xu Zhenjia, a craftsman with experience, uses a blade to level the plane obtained by roughing, and while he is scooping out the plane of the demand, he still makes a contrast plane, and then on the control plane. Apply the color and slide the processing plane on the control plane. At this time, the color part on the processing plane and the color part on the control plane are the higher parts on the two planes, and the demand is shoveled again. The process is repeated abruptly, from time to time the color of the two planes is up to the uniform, and the knife marks left on the plane are just as the lubricating oil groove, double-edged. But this is not an absolute plane, because it is assumed that the same curvature between the two faces will produce the same effect. This is just that the two faces are intact and cannot be guaranteed to be flat, so another reference plane is required. . Generally speaking, when machining an absolute plane, it is necessary to process three planes at the same time. In the three planes, the two sides are divergent, and the absolute plane is calculated.
The companies that normally use the absolute planes required for this type of process machinery are mainly in Germany, Switzerland and Japan, which is why these countries can consume high-precision mechanical equipment. This kind of precision processing company in Japan is mainly concentrated in the area around the 43 degree north latitude of Niigata Prefecture. There is a climatological reason here. The Japanese craftsmanship was learned from the Germans. At that time, when the government selected the address of the precision processing industry, the climate was selected to be similar to the 43 degree north latitude in Germany. The humidity is small and the temperature is also coiled at around 20 degrees Celsius, which is most suitable for precision machining. At that time, there was no air-conditioning equipment. It is unimaginable to install air-conditioning equipment in the consumer workshop. Therefore, it is necessary to pay attention to the temperature difference when selecting the site. The material expansion and contraction caused by the temperature difference has a great influence on the manufacture and assembly of precision products.
The temperature difference not only affects the workpiece, but the bed of the ultra-precision grinder that I have seen does not use ordinary cast iron, but uses granite to reduce the influence of temperature difference. These enterprises are basically small companies with several people to dozens of people. It is said that small workshops are not too hot, but apart from these small workshops, world-renowned mechanical brands such as Yasuda, Mori and Makino cannot be established. The Japanese economy has been sluggish for more than a decade, but these companies that are engaged in the manufacture of sliding planes have never been affected. Because this industry is the most fundamental of manufacturing, demanding technology and rich experience, it has only been Not enough, no excess. In particular, as the range of applications of electronic technology expands from time to time, the demand for high-precision processing machinery will only increase from time to time without reducing.