The spinning process is a process in which the metal plate in the high-speed rotation close to the mold is pressed with a strip-shaped tool called a “catch bar”, and the metal plate is shaped into various cylindrical products. The processing accuracy is as low as 0.1mm, and the superb technology of gradually transforming the metal plate into the shape of the product in the hands of master craftsmen is the pinnacle. “Spinning” is a metalworking process that relies heavily on the manual work of master craftsmen.
Today, I will take you into the Kitajima deep drawing factory in Japan to see how their spinning process is?
The materials used include spinning processing of metal materials such as iron, aluminum, stainless steel, copper, and brass. Sometimes precious metals such as gold, silver, and platinum are also processed. In addition, the processing of metals with relatively high hardness, which are called rare metals such as molybdenum, tungsten, tantalum, and titanium, is also increasing. From beverage can samples to satellite equipment, airplanes, parts of semiconductor manufacturing equipment, and giant satellite antennas, they perform spinning of various parts, large and small.
The metal spinning process starts with cutting a metal slab into a circle. Then install the circular metal plate and the mold on the spinning machine, let them rotate together at high speed, while applying lubricant, push the metal plate with a “stick” to make it close to the mold to complete the shaping process.
Before starting the spinning process, the metal slab is cut into circular shapes using a machine called a disc shear.
Concentrate every nerve in the whole body, while moving the legs to alternately bear the body weight, and use the stick to evenly press the blank to make it shape.
While adjusting the button position of the stick fulcrum, operate it carefully with the stick.
We saw such a huge mold in the workshop, and also saw the innermost wooden mold.
During the processing process, it is necessary to judge whether the slab is perfectly formed according to the mold according to the sound made when the metal slab is struck and the feeling from the “catch the stick”. Excessive force will cause the product to be scrapped. Therefore, master technicians need to concentrate every nerve in the whole body when performing the spinning process. pressure.
The difference between spinning process and stamping machine processing
Because metal is elastic, it will return to its original shape after being deformed. Therefore, even if an attempt is made to shape the blank by pressing it against the die, slight molding failures will occur due to this characteristic of the metal. Compared with the slow forming of balanced pressure in the “spinning process”, the blank is locally stressed when the stamping machine is processed, so this tendency is more obvious. Therefore, only the “spinning process” can be realized for metal processing that requires high precision of finished products.
In addition, the number of molds required for processing is also different between the two processes. Stamping machine processing is to sandwich the blank between a pair of molds for processing, so a pair of molds is always needed. The “spinning process” only needs one mold, thus reducing the cost of the mold. This is why the “spinning process” is often used in small-scale production such as sample processing. However, from a productivity point of view, press processing is more beneficial. For mass production that does not require high precision, Kitajima Deep Drawing Works also uses automatic spinning machines and punching machines for processing.
Where is the spinning process difficult
When processing extremely thin slabs (about 0.1mm), lightly pressing with a “catch bar” may cause deformation of parts other than the target position, so the operation must be done with caution. Conversely, when the thickness of the metal slab of some materials exceeds 5mm, it is necessary to increase the strength. Especially when processing a hard and thick metal plate, if you apply a lot of pressure with the “catch stick”, it is likely to cause damage to the lower end (the fulcrum of the lever) that supports the “catch stick”, or the “catch stick” The pointed part of the head was damaged due to the inability to withstand the force.
In addition, since the “spinning process” is a process of applying uniform pressure to the metal plate to stretch it, it requires extremely high technology to shape the metal plate into a long and large product using only the “rolling rod”. The operation of the spinning process needs to be felt, so the formed product reveals its personality. No matter how skilled a master craftsman is, when the physical condition is not good, it will inevitably affect the shaping effect of the product.
Dare to try and challenge, the product is the best advertisement
I don’t think there’s anything special about what we do. It’s just that many other companies do not want or are unwilling to undertake business, and our company has taken the lead in trying and challenging. And once a certain business is undertaken, no matter how difficult it is, it will be completed satisfactorily. Take the compliance with the delivery date as an example. Even if the actual processing operation does not progress as smoothly as the procedure imagined when receiving the order, our company will never delay the delivery. Some new customers will express surprise at the expensive price on our submitted quotation. But we are confident that the products we provide to our customers are of equal value. In fact, in the past, we have encountered customers who placed an order with a competitor with a lower quotation, but came to our company to place an order again due to poor product quality.
In addition, when the material of the blank is a rare metal, not only the processing is difficult, but also the material cost is high. Ordinary metal processing factories will choose to give up considering the risk of processing failure, but our company is always very active in undertaking such business in order to accumulate experience. Our company has no marketing staff, because we believe that as long as we can produce high-quality products, the product itself is the best advertisement.
The inheritance of craftsmanship is inseparable from the accumulation of experience
A while ago, the oldest master mechanic in our company retired. However, his technology has been passed on to craftsmen of all ages, such as 20, 30, and 40. It can be said that the technology has been well passed down. Our company has never had any spinning operation manual. Because many details depend on people’s feelings, they cannot be explained in words. New employees learn a lot from the experience of older employees while working with senior employees. It takes at least 10 years for a new employee to become an independent technician. Depending on the type and shape of the metal, the method of applying pressure is also different, and the technique can only be mastered by working hard at various processing sites and gradually accumulating.
Enjoy the making itself
Spinning starts from thinking about how to make the shape of the product entrusted by the customer. We not only make the molds by ourselves, but also process all the sticks by ourselves. Challenging things that have never been done before, and products that were considered impossible to process under the conditions of the spinning process will make people feel the value of the work. In the past, a customer commissioned us to shape and process beverage cans with very thin heads. Although the forming process can be carried out under the conditions of the spinning process, because the head diameter of the die is small, it is a big problem that the slab cannot be removed from the die after forming. After trial and error, in order to allow the product to be disassembled after forming and to be removed from the mold, we solved this problem by cutting the mold into segments in advance and connecting the molds during forming. We are not only satisfied with the Crafting a Musical Drum Body technology, but are also committed to researching the product manufacturing process, improving the processing tools, experiencing and enjoying the production process itself.
It is said that there are about 400 spinning companies in Japan, and their scale is about 10 people. Although they are small in scale, spinning is also one of the essential technologies for manufacturing small varieties of machined products. It is also considered one of the cornerstones of Japan’s precision manufacturing industry.