According to time, it can be divided into three stages, namely, from ancient society to17th century, the origin of mechanical design and the ancient mechanical design stage, from17th century to the end of World War II, and the modern mechanical design stage. According to its content, it can be divided into intuitive design stage, empirical design stage and theoretical design stage. The two kinds of division are one-to-one correspondence, that is, the development history of mechanical design is divided from different angles. Each stage has obvious characteristics in design theory, method and manufacturing technology. We divide the history of mechanical design into three stages according to time. 1. 1 Origin and ancient mechanical design The archaeological discoveries in China in modern times have proved some legends and records. In Hemudu, Yuyao, Zhejiang, and Zhengpei, Khan Lee, Henan, quite exquisite farm tools such as stone shovels made seven or eight thousand years ago were found. There are many records about the use and manufacture of machines in China ancient books. It can be seen that "the Yellow Emperor, Yao and Shun have made great contributions, chopping wood is a ship, chopping wood is a thunderbolt, and chopping wood can't help", "Leading a cow to ride a horse, leading a gentleman far away" and "breaking wood as a pestle and digging the ground as a spoon". Cars, boats, farm tools and many household appliances were invented in ancient China more than 4,000 years ago. There is a "golden chariot" in the forty-seventh hexagram "sleepy" in Zhouyi, which refers to a luxurious carriage decorated with copper. Rizo, a scholar in Qing Dynasty, said that "the Six Classics are all history". We can see that in ancient China literature, mechanical products are closely related to people's lives everywhere. In the book Tao Te Ching in the Spring and Autumn Period and the Warring States Period, there is a saying that "30 spokes are a hub, like the sun and the moon", while the No.2 bronze chariot unearthed from the Qin tomb has 30 spokes. According to statistics, at that time, cars used 30 spokes per wheel, but the number of spokes was regulated. In addition, China also made many inventions in weapons, textile machinery, farm tools and ships in ancient times. By the Qin and Han Dynasties (22 BC1to 220 AD), China's mechanical design and manufacturing had reached a fairly high technical level, which was in a leading position in the world at that time and occupied a very important position in the history of mechanical engineering in the world. In ancient China, mechanical inventions, designers and manufacturers were unified. There are many famous people whose achievements represent the design level of machinery in China at that time. During the Tang Dynasty, China carried out economic, cultural and scientific exchanges with many countries, and had frequent trade exchanges with Southeast Asia, South Asia, Arabia and the east coast of Africa, which had a great impact on China and other countries in the world. Due to the development of trade, it is required to increase commodities, thus improving production equipment and making great progress in mechanical design. Paper, textile, agriculture, mining, ceramics, printing and dyeing, weapons, etc. All of them have made new progress, and the level of mechanical design has also improved by a big step. Meng Qian Bi Tan written by Shen Kuo in Song Dynasty recorded many scientific achievements and reflected the scientific level at that time. Other countries in the world also have many mechanical achievements. However, most of these designs are based on the designer's experience and lack of necessary and accurate theoretical calculation. 1.2 Modern mechanical design 65438+The rise of navigation, textile, watch and other industries in Europe in the 7th century raised many technical problems. 1644, the "Institute of Philosophy" was established in Britain, the experimental research society and the Berlin society were established in Germany, 1666, and research institutions were also established in France and Italy. Galileo (1564~ 1642), an Italian who worked in these institutions, published the laws of free fall, inertia and the motion of throwing objects, and conducted bending experiments on lintels. Newton, an Englishman, put forward three laws of family motion 1688, and he put forward a formula for calculating the viscous resistance of fluid, which laid the foundation of classical mechanics. Hooke's law was established by Englishman Hooke, and the stress and strain of elastic body should be proportional within a certain range; In 1705, Bo worked hard to put forward the differential equation of beam bending, and established and developed modern mechanical design theory (also known as conventional mechanical design theory) on the basis of classical mechanics, which provided strong technical and theoretical support for the rapid development of mechanical industry in18th century industrial revolution. 1764, the Englishman Watt invented the steam engine, which provided powerful impetus for textile, mining, smelting, shipbuilding, food, railway and other industries, promoted the demand for machinery in many industries, and made the machinery industry develop rapidly. Mechanization has rapidly increased productivity and entered the era of industrial revolution. During this period, many requirements were put forward for mechanical design, and the load, speed and size of various machines were greatly improved, so the theory of mechanical design also developed rapidly on the basis of classical mechanics. Material mechanics, elastic mechanics, fluid mechanics, mechanical mechanics. Fatigue mechanics, fatigue strength theory and experimental stress analysis methods have achieved a lot and established their own discipline system. 1854, the German scholar Laurex published the book Design in Mechanical Manufacturing, which separated the mechanical design dissolved in mechanics in the past and established a new scientific system based on mechanics and manufacturing, thus releasing "mechanism" and "mechanical parts design" and becoming the basic content of mechanical design. On this basis, mechanical design has developed rapidly. A lot of achievements have been made in fatigue strength, contact stress, fracture mechanics, high temperature creep, hydrodynamic lubrication, gear contact fatigue strength calculation, bending fatigue strength calculation, rolling bearing strength theory and so on. The continuous emergence of new technologies, new materials and new structures has also made great progress. The volume of the machine is reduced, the speed is improved, the performance is improved, and the calculation method and data accumulation of mechanical design have also developed greatly, reflecting the characteristics of the times. 1.3 Modern Mechanical Design After World War II, mechanics, as the theoretical basis of mechanical design, continued to develop at a more rapid speed. Tribology, reliability analysis, mechanical optimization design and finite element calculation, especially the rapid popularization of computers in mechanical design, have greatly improved the speed and quality of mechanical design. The wide application of computers in machinery and the improvement of automation make modern machines have obvious characteristics. Therefore, compared with the past, mechanical design has made epoch-making development in theory, content and method. The fierce competition in the international market is a method of modern mechanical design and a catalyst for its development. Countries all over the world gradually realize the important role of product market competition in national economic development. In the product competition, facing the flood of American products printed with "Made in America" in the German market, Germany plans to restore the reputation of German products, make "Made in Germany" popular all over the world, and put forward the slogan "der eng passist die deconstruction". Although Japan lags behind some countries in some cutting-edge scientific research, it has developed rapidly in product design, quickly got rid of the impression that "Japanese goods are not good" before World War II, and produced a large number of products needed by various countries' markets, and achieved great economic benefits. The United States and Britain have gradually realized the importance of product design. The United States put forward the slogan of "designing for competitive advantage". Some people say that "2 1 century will be the century of design". Therefore, the design of mechanical products has achieved unprecedented development in this period. At present, mechanical design is not suitable as a branch of mechanics, and should be considered as a technical discipline alongside mechanics. Modern mechanical design method is characterized by its own discipline system and special content. Its core technology has three aspects: (1) Taking the "function" of products as the core goal of mechanical design. Myers put forward that "what customers buy is not the product itself, but the function of the product", and clearly stated that "function" is the essence and soul of the product. This principle has greatly liberated the designer's mind. In order to achieve a certain function, various principles and structures can be adopted. We can see from the rapid development of timing devices, file copying equipment and communication methods in recent years that the ingenuity of designers has been brought into unprecedented play and the needs of society have been met in many ways. (2) The formation and development of "ergonomics". Mechanical work is often inseparable from people, such as cars and airplanes, and some control signals depend on human input. The limitation of the operator's reaction speed and ability must be considered, and the transmission comfort of the operator and passengers must also be considered. If a weapon designer has considered the user, although Lei is conveniently right-handed, he is also accustomed to being left-handed (called left-handed or left-handed). Although many products have developed to automation, many civilian products have low requirements for users' extraction (commonly known as "stupid"). But the competition of mechanical products is designed for human beings after all. Considering "ergonomics" is an important aspect to improve the competitiveness of products. In fact, "fooling" is an important way to deal with man-machine problems at present. (3) Establish a systematic "industrial design" discipline system. Industrial design is the designer's rational design of products in appearance, color, modeling and size proportion, which makes products more harmonious with people and the environment, thus obtaining better use effect and competitiveness.