With the development of mechanical manufacturing to this extent, there has been no big breakthrough in part forming, and it is basically supported by several traditional ways, even though 3D printing, which has recently been hot, is more likely to stay at the level of proofing and impractical publicity, and it has not been widely and universally applied to the field of mechanical molding, which has to be said to be a kind of sadness in the manufacturing industry.
Holding back has become a foregone embarrassment.
Of course, even if it is the traditional way of forming parts, many people do not really know it, and most of them may have little knowledge (in fact, I am also at the level of half a bucket of water).
The following is my cognitive scope to give you a “forced” popular science, welcome to check gaps and make up for gaps, hoping to have the effect of throwing bricks to attract jade.
First of all, part forming is basically divided into two categories, one is material reduction forming (removing materials), the other is increasing material forming, so far, material reduction forming is still the mainstream way of part forming.
01 Material reduction forming
There are many kinds of material reduction molding, and we mainly classify them based on the blank of the parts.
Because the final way of material reduction still depends on the means of machining, but the source of the blank of the part is very different, so the following introduction is completely based on the acquisition of the blank of the part to classify.
A. profile reduction forming
As shown in the following figure:
From the above picture, we can see that the blanks of many parts in our manufacturing process come from the reduction processing of these two kinds of profiles, and the final shape and dimensional accuracy of the parts are achieved through a variety of machining equipment.
These equipment include: wire cutting machine, lathe, milling machine, planer, boring machine, drilling machine, grinder and so on.
This molding method has the following advantages:
(1) the processing cost is low, because they are all standard materials, so the purchasing cost can be controlled.
(2) the processing cycle is short, which can be obtained by purchasing directly in the material market, and basically all of them are in stock.
(3) the quality of the material is good, because it is a standard profile, so it is more reliable in quality control.
(4) the processing adaptability is good, as long as you are not afraid of the high processing cost, you can basically process most of the shapes you want.
This kind of molding is also the most commonly used molding method at present, and many mechanical processing plants will stock such raw materials with a certain base, so that they can do the best in cost control and periodic surplus.
At the same time, this is also a kind of mechanical processing method that mechanical graduates are most likely to come into contact with. Maybe your whole life is to deal with several cycles of processing with the title of a mechanical process engineer.
Although it seems very simple, there is a lot of knowledge in it, and many people can’t get their first glimpse of it for the rest of their lives.
B. casting molding reduction processing
As shown in the following figure:
From the above picture, we can see that the blank of the part comes from casting molding, but the casting parts need to be further reduced if they want to meet the design requirements of the product.
The means and methods of processing are basically the same as those of the profiles above, except that the casting parts have the following characteristics:
(1) it can be made into all kinds of special-shaped parts, and the machining margin of reducing materials can be greatly reduced.
(2) the machining cost of the parts can be minimized, because the machining allowance of the parts can be controlled.
(3) the material selection of parts can be more flexible and have better product adaptability.
(4) there are some hidden dangers in the uniformity of materials, and it is also very difficult to remove the casting stress, and many enterprises will even cut corners in these aspects.
(5) the cost of the blank of parts is too high, especially there is a great obstacle to the manufacture of parts which can not be made in batches.
In fact, casting parts is a very dangerous job.
The enterprise where a friend once worked was a relatively large foundry. One day the crane was carrying a bowl of molten iron to cast. During the hoisting, the steel wire was broken, the molten iron was instantly poured down, and the workers below had no bones and were melted to the point where there was no slag.
My friend was so scared that he resigned and left the next day, which is a lifetime shadow that can not go away.
So I seldom visit the foundry, even if the company has arrangements, I also try not to enter the dangerous area, because I also have a shadow.
As the so-called gentleman does not stand under a dangerous wall, I warn myself that I should always stay away.
However, this kind of part forming is the mainstream way that can not be avoided in the machinery industry, especially in the forming of large-scale equipment.
Perhaps advances in automation technology can change the traditional way of this type of work and make it safe and easy, but there is still a long way to go.
C. forging forming reduction processing
As shown in the following figure:
From the picture above, we can see that the forming of parts comes from forging, which is a very old part forming process.
Ironing is the most primitive method of forging, and ironing was once a little dream of mine.
In fact, I have always had a fondness for traditional mechanical processing, and I think it is based on human technology.
In fact, the iron strike is very talented. Wei Chi Gong, the founding general of the Tang Dynasty, was a blacksmith. Mo Ye, the maker of the famous sword in ancient times, was also a blacksmith, and the founder of Longquan Sword, Mr. ou Ye Zi, was also a blacksmith.
When you reach a certain level as a blacksmith, you are not called a blacksmith, but a master, so this is a very powerful technical work.
In fact, the forging of modern technology has begun to realize automation.
About half a year ago, I visited a company and went to a forging workshop, which was beyond our understanding.
The workshop is very clean, so clean that it is extremely incommensurate with the word forging, and all forging processes are transferred and carried out through the manipulator of ABB. At the same time, the processing data also have corresponding information statistics and output, which looks like an intelligent factory.
Among them, the forging equipment left an extremely profound impact on me, because the director told us that the purchase price of that forging equipment was close to 100 million.
What is an enterprise with heavy assets? this is probably what it is.
In front of this forging equipment, what kind of luxury cars and mansions are so weak that they can hardly be mentioned.
Forged parts have the following characteristics:
(1) it can improve the microstructure and mechanical properties of the parts.
Due to the realization and recrystallization of metal after forging hot working deformation, the original coarse dendrites and columnar grains become equiaxed recrystallized structures with fine grains and uniform size.
As a result, the original materials are compacted and welded, such as segregation, porosity, porosity, slag inclusion and so on.
The microstructure is tighter and the plasticity and mechanical properties of the metal are improved.
(2) profiling forging can be carried out according to the final demand shape of the parts, so as to reduce the machining allowance of the parts and save the processing cost.
Of course, from the picture above, we can still see that forging this job is still a very dangerous job.
If it is a completely manual operation, its risk coefficient is not under the casting molding, so the intelligent factory based on automation is the fundamental direction to solve this problem, and now many enterprises have very good application cases.
We look forward to a better future.
The above three kinds of parts forming methods are more typical and general ways of reducing material forming, and they are also the most common way to use.
Basically, these three ways are the main ways that we can come into contact with in the enterprise.
02 Increasing material forming
When it comes to molding, we have to talk about 3D printing technology.
This technology has become very popular now, especially in the news media, many so-called 3D printing products subvert our perception of 3D printing cars, 3D printing pistols, 3D printing products and so on.
There is a tendency to take the place of reduced material forming.
In fact, this road is still a long way away, from the current point of view, there is no possibility, maybe this is just a good story-telling gimmick, compared with many people make money by selling the future and dreams.
We can learn about the process of 3D printing through the following group of pictures.
My understanding of 3D printing basically stays in the impression of making the first edition of the sample.
Because usually when developing products, it is true that they have used 3D printing products, but the printing effect is really unflattering.
Either the surface roughness is too bad, or the printed parts are “missing arms and legs”.
In short, there is no one to my satisfaction, and my contact is limited to the printing of plastic parts.
Maybe I am ill-informed, I am not very optimistic about this technology, maybe it does not show the potential that I am optimistic about, or maybe it is because the frog in the well, such as I have not yet had the opportunity to come into contact with those real high-end 3D printing products.
Of course, although the current technology is not perfect, but we can not deny that this is indeed a kind of part forming method in the future, and it is a means with great possibility.
From this point of view, I think we should be optimistic to understand it.
To sum up, it is based on my personal knowledge and experience of some parts forming method introduction.
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