These mechanical design experiences, the master will never tell you in his life!

Mechanical design runs through the whole process of design, manufacturing, use and maintenance, and the negligence of design will always be reflected in these aspects, and it is easy to judge whether it is successful or not. In the process of design, it is greatly affected by manufacturing, that is, good design cannot be separated from manufacturing, and the more you understand manufacturing, the more it will help to improve the design level.

The design of the drawings, put into production, I have not seen many can be immediately processed and assembled according to the drawings, in the process of drawing review, process and other processes to find a large number of problems are very common, including the so-called "senior" senior engineer, the chief engineer to come up with the drawings, or after many meetings to study and discuss the results of repeated discussions. There are many reasons, the standardization of the drawing, the level of the viewer is one thing, but the designer's lack of understanding of the manufacturing process is the main reason.

The easiest way to do this is to grab a drawing of something you designed, and can you tell you how it was made? Casting, forging, turning, pliers, milling, planing, grinding, just like this, it is definitely not possible, who has been in the machinery factory for a few years does not know? For example, how to divide the casting, how to put the gate riser, what kind of casting defects may occur, whether the part structure will lead to accidents during heat treatment, how to optimize the part structure, the cutting process, virtualized in the mind, a total of how many knives are used, the speed, the amount of cutters, and even where the iron filings fly, the order of each tool, the whole process of the operation of the lathe, miller, grinder, and so on, can be regarded as having a better foundation.

It is not that you must be able to play lathes, milling machines, and welding, but you must know the characteristics of these operations and fully consider them in the design. As a person engaged in mechanical design, this is stronger than shaking the lathe and burning electric welding, so that there is a place to live. In this way, in the design process, some unreasonable structures will be avoided, and the quality of the design will naturally improve a lot, but it is not enough, a technician with ten or eight years of experience can put forward a more mature detail plan than you (although the overall design coordination they can't do), but how many sleepless nights to design such a result, isn't it Sven sweeping the floor? The only solution, read more books. What others summarize is usually combined with production, and it is the crystallization of hard work. Learn with questions, and you can digest them if you think about them. Never again say "just ensure concentricity" such a stupid answer, the point is that you have pointed out the way to ensure concentricity, or even the mistakes of your predecessors. At this time, no one calls you Xiao Qian and Xiao Zhao anymore, and even the boss calls you Qian Gong and Zhao Gong, which is quite respectable. Touching the chin, the beard has grown, the diaper has been lost, the child has called his mother, and the sense of accomplishment has also come.

However, design is always for use, good design must have a little bit of humanity, design a set of process equipment, a trial production, high efficiency and high quality, the boss to make a glass of celebration wine. After a few days, I found that people abandoned it because the operator scolded my mother. It's painful to use. And there are a lot of details to pay attention to, if he was an operator, he wouldn't still be an operator if he considered so many factors. The design is not conducive to use, it is facing elimination, there are many complete sets of equipment, such as the engine and gearbox of the car and the like are "very good" when running normally, but one of the small keyways, a bearing position, something is broken, the whole can not be used, the factory only sells the whole piece, to the accessories are not sold, there is really no place to add their own strengthening, change a few factories to buy, put a bunch, users have to stay away, set up a technical transformation project - poor technical transformation.

As long as you have been in the machinery industry for a long time, you will see and hear of it. The use is inseparable from maintenance, and good design cannot ignore maintenance. In a large-scale production line, the key equipment, a total of two maintenance a year, but each time the equipment has to be unloaded eight pieces, forklift jack crowbar eighteen weapons are not enough, the masters also have to use their own brains to play a few good special household goods to serve, resulting in the loss of production has exceeded the value of the equipment itself, it is really a wordless ending. A set of large-scale equipment only because of the replacement of an oil seal or something, to almost completely decompose the whole machine, the use of the unit does not scold the design is to do the offspring of the thing is strange, it is really the sadness of the designer.

We should not only stand on the basis of manufacturing, but also innovate, but we must learn to inherit. Now, the whole society is emphasizing innovation, but we can't just emphasize innovation and look down on the original things. There are two types of innovation, one is the recombination of the old elements that make up things, and the other is the addition of some new elements to the old elements. So, no matter what, it's undeniable that something innovative always contains some shadow of something old. Just as philosophy says, new things are born out of affirmation, and negation is produced in affirmation. For example, we humans, although we are said to be the pride of nature, in fact, 99% of our genes are the same as gorillas.

If human beings do not have a 1% breakthrough on the basis of inheriting the genes of gorillas, the emergence of human beings is unimaginable, if someone says that I have ambition and do not need to inherit the genes of gorillas, and I make a 100% pure human gene myself, then you will not be able to make a human in another 100 million years. Therefore, we can't completely abandon the old things for the sake of innovation. The original thing is like a dish, and innovation is like a little seasoning, with such a little seasoning, the taste of the dish is more delicious. But no one wants vegetables for the sake of pure deliciousness, just a plate of fried seasonings. Therefore, we emphasize innovation, but we must not forget inheritance, only inheritance, no innovation, that is conformism, and only innovation, no inheritance, that is a castle in the air.

1:1 cloning may be considered by many people to be the safest and least hassle-free way to design. But as someone in the design industry, cloning is a shameful thing. The so-called one copy, two changes and three creations. It concisely summarizes the growth path of designers. When you first get started, you can only copy, but at the same time of plagiarism, you have to desperately understand the intention and thinking of the original designer, understand the transmission of the whole machine, the interconnection between the various devices, and the interrelationship between each part. I only know how to draw it, and pull a few lines on it, probably feel that the precision of the machine is relatively high, so I try my best to lift the accuracy up to 0.005, 0.002, and the signature on the drawing is not ashamed in the design column. The things that claim to be engaged in are very sophisticated. This kind of so-called mechanical design engineer is everywhere.

Imitating good works is a must for every designer. But to do design, you must have your own ideas, people must also have their own distinctive personality, for a long time, they have formed their own style, and the cultivation of style is directly related to a person's artistic quality and personal accomplishment. The things made by a wordy person are so wordy, the things made by a stingy person are a little family, and the machine made by an irresponsible person is as irresponsible as that person's virtue. To have your own design concept and design style is different, so that the things that come out have a unique soul. Connoisseurs will know at a glance that this is a masterpiece of care.

When you accumulate experience in plagiarism, you should learn with a negative attitude. Consult the information, read more classic design cases, and design taboos, and compare them with some things that you have been exposed to, and you will have a great improvement. It is possible to perform the operation on an existing machine. For example, improve the added value of the machine, improve more functions, and make the whole machine have higher reliability. This can cater to high-end customers, or streamline the structure, retain some common features, reduce costs, and meet the needs of customers who can't afford it and don't need it. In this way, you can be called to start doing mechanical design. It's hard to say whether you can become a world-class inventor, hehe. But with my years of experience and knowledge, it is not difficult to combine, mutate, graft, and create something new. Instead of spending a lifetime studying advanced topics such as perpetual motion machines, or engaging in so-called patents that inexplicably cannot create any value, it is better to use your limited life to do something that can leave a mark on this beautiful planet. When the time comes, he will be old and dying, and when he is dying, he will still think that after living for so many years and making so many machines running on the earth, it is enough to laugh at Jiuquan.

A real mechanical design engineer needs ten years or even more than ten years of training. It is also necessary to have considerable talent and to be diligent and to be able to cultivate people. Genius is equal to 99% diligence + 1% effort, in fact, it does not mean that as long as you work hard, you will achieve something. This sentence is that if a person does not have that 1% talent for a certain profession, no matter how hard he works, it is useless. Diligence is a way to discover one's own talents, and it is one of the necessary conditions for achievement, but not the whole thing. Definitely not. machine

The principle of material selection of mechanical parts should consider the requirements of three aspects

1. Requirements for use (primary consideration):

1) The working conditions of the parts (vibration, impact, high temperature, low temperature, high speed, high load should be treated with caution); 2) The limitation of the size and quality of the parts; 3) The importance of the parts. (Relative importance to the reliability of the whole machine)

2. Process requirements:

1) Blank manufacturing (casting, forging, cutting plates, cutting rods);

2) machining;

3) heat treatment;

4) Surface treatment

3. Economic requirements:

1) Material price (comparison between the cost of ordinary round steel and cold-drawn profiles, precision casting, precision forging blank cost and processing cost,);

2) processing batch and processing costs;

3) Utilization rate of materials (such as the specifications of plates, bars, and profiles, and make reasonable use of them)

4) Substitution (try to replace relatively expensive rare materials with cheap materials, such as replacing copper sleeves with ductile ink in some wear-resistant parts, replacing some sets of turning processing with oil-impregnated bearings, and replacing steel gears or copper worm gears with nylon when the speed load is not large, etc.).

Also, consider the availability of local materials

1. The basic requirements of mechanical design

a) Pay attention to the coordination and balance of the functional requirements of the machine!

b) Requirements for machine economy Design economy, put into production and market in a short period of time, recover the consumption during development, and even design and manufacture The use economy should have the best performance-to-price ratio (the product starts to earn in small batches, and then changes it better)

2. The basic requirements for the design of mechanical parts

a) Work normally and reliably within the predetermined working period to ensure the various functions of the machine;

b) To reduce the production and manufacturing costs of parts as much as possible;

c) Adopt as many common standard parts as possible in the market;

d) For products that may be serialized, consider the versatility of parts at the beginning of the design as much as possible, and if they cannot be universal, they should be similar in structure as much as possible, so as to reduce the process arrangement of the manufacturing process and the workload of fixture tooling design.

This is the end of the explanation of mechanical design, and you are welcome to add.