During the 23-day production practice, we have been to Hangzhou General Machine Tool Factory, Hangzhou Secret Machine Tool Processing Factory, Shanghai Valve Processing Factory, Shanghai Volkswagen Automobile Factory and Hangzhou Engine Factory to learn about the production situation of these factories, all kinds of knowledge related to this major, the work situation of workers in various factories and so on. For the first time, I personally felt the application of knowledge and practice, the application of sensors in air conditioning equipment, the application of electronic technology in machinery manufacturing, the application of precision machinery manufacturing in machinery manufacturing and so on. The combination of theory and practice is an eye-opener for us and a preliminary test of what we have learned before. Through this production practice, the theoretical knowledge learned has been further consolidated and deepened, which makes up for the deficiency of single theory teaching in the past and lays a good foundation for the subsequent professional course study and graduation design.
Hangzhou General Machine Tool Works
On July 3rd, we came to the first stop of internship, Hangzhou General Machine Tool Factory, which belongs to Hangzhou Machine Tool Group. This factory mainly produces M-class grinders 7 130h and 7 132h, which is one of the relatively large machine tool factories in China at present. During the internship, we first heard a series of safety matters and precautions. Safety is always the first issue in mechanical engineering practice.
At the end of the next period, we are divided into three groups, which are engaged in production practice in general machine workshop, special plane workshop and processing workshop respectively. In the switchboard workshop, the workshop leader showed us their production line, and explained in detail the processing and assembly technology of the main parts of the surface grinder, the power drive of the whole machine and a series of structures of the internal hydraulic system. I should be most interested in the hydraulic system of the surface grinder, which is divided into oil supply institutions. Executive mechanism, auxiliary mechanism and control mechanism. From different angles, the hydraulic system can be divided into different forms. According to the oil circulation mode, the hydraulic system can be divided into open system and close system. Open system means that the hydraulic pump sucks oil from the oil tank, the oil drives the hydraulic actuator after passing through various control valves, and the oil returns to the oil tank through the reversing valve. The system has a simple structure and can play the role of cooling the oil tank and precipitating impurities. However, oil often comes into contact with air, which makes air easily penetrate into the system, leading to unstable mechanism movement and other consequences. The open system has large oil tank and good self-priming performance of oil pump. In close system, the oil inlet pipe of the hydraulic pump is directly connected with the oil return pipe of the actuator, and the working fluid circulates in the pipeline of the system in a closed way. Its structure is compact, there is less chance of contact with air, and air is not easy to penetrate into the system, so the transmission is stable. However, the close system open system is complex, because there is no oil tank, the oil cooling and filtering conditions are poor. In order to compensate for the leakage in the system, a small flow make-up pump and oil tank are usually needed. Due to the high technical requirements and high cost of closed system, considering the economic problem, the surface grinder adopts the starting system and adds shock absorbers to balance the system. Almost all modern construction machinery adopts hydraulic system, which is combined with electronic system and computer control technology and becomes an important part of modern construction machinery. How to design a good hydraulic system? It is the key technology to improve the level of China's machinery manufacturing industry. In the workshop of special plane, our research on the special structure, feed mechanism and processing range of special plane grinder is further deepened, which is more beneficial than asking the master for the principle of power transmission. In the processing workshop, we have a more accurate perceptual knowledge of the planer and shaper, and listened to the master's talk about the five parts of the machine tool: bed, column and grinding head.
Through the internship in Tongji factory, I learned the basic situation of manufacturing industry at present. It's a pity that I can't do more practical operations because of the unique technical proficiency and high risk in the mechanical industry. However, I observed the production, processing and assembly process of various parts of a machine tool, which brought to life a lot of knowledge I learned from books and understood the specific application of this major in some technical manufacturing aspects.
Hangzhou precision machine tool factory
On July 8th, we went to Hangzhou Precision Machine Tool Factory under Hangzhou Machine Tool Group. As the name implies, Hangzhou Precision Machine Tool Factory is a big factory that produces some machine tools with high machining accuracy and high technical requirements. Mainly processing some high-precision small parts or some high-precision machine tools, such as M-class and MM-class surface grinders. Because of the high processing requirements and sophisticated machines, some of them have to be served in a constant temperature environment. Only in this way can the working performance of the machine tool be guaranteed.
After listening to the explanation of the worker's master, I understand that the processing flow of general parts is as follows:
Blank-scribing-planer (technically leaving machining allowance)-rough turning-heat treatment, dressing-semi-finishing of lathe-grinding-gear machining-quenching (tooth surface)-grinding surface.
Processing technology of gear parts;
Rough turning-heat treatment-finish turning-grinding inner hole-grinding core, shaft end face-grinding the other end face-hobbing-clamping teeth-shaving-countersunk keyway-fitter-completion.
Seiki has three machining centers and several CNC machine tools for grinding heads. Numerical control machine tools are small in size, relatively cheap and convenient to process. The machining center has a tool holder and multiple tables, which can process multiple working faces at the same time, which not only avoids the error caused by misalignment of benchmarks, but also greatly improves the machining efficiency. However, the machining center is bulky, expensive, and requires higher environment, which increases the product cost.
Internship in Seiki Company has greatly enriched my knowledge of parts processing technology and expanded my knowledge. In this internship, I deeply felt the importance of CNC machine tools in mechanical manufacturing. It is a combination of electronic information technology and traditional processing technology. It integrates modern precision machinery, computer, communication, hydraulic pneumatic, photoelectric and other multidisciplinary technologies, and has the characteristics of high efficiency, high precision, high automation and high flexibility. It is an indispensable production equipment for cutting-edge industries. At present, most of China's CNC machine tools come from advanced foreign manufacturers, and China's manufacturing industry lags far behind developed countries in terms of quantity, accuracy and performance indicators, which requires us to catch up.
Shanghai Valve Factory &; Shanghai Volkswagen automobile manufacturing co., ltd
The next day, we went to Shanghai by bus, because the time was short, so this trip to Shanghai should focus on sightseeing. It is difficult to obtain ideal internship effect because of the short time in Shanghai Valve Factory. The visit to Shanghai Volkswagen Automobile Co., Ltd. let us know the development direction of machinery manufacturing industry to a certain extent, which I think is the biggest gain of this trip to Shanghai.
At present, with the application of a series of high and new technologies such as automobiles, how to better combine electronic technology with mechanical technology and realize electromechanical integration will be the top priority of future mechanical development.
Hangzhou engine factory
The last stop of our internship was Hangzhou Engine Factory, built at 1958, which was formed by the merger of Hangzhou Power Factory and garage. The factory participated in the production of the first heavy oil dyeing machine, the first tractor, the first bus and the first trolley bus in Zhejiang Province. 1992 was listed as a national key large-scale enterprise and the reputation of Zhejiang machinery 100. At present, the factory has employees 1800 people and more than 2000 professional machines. X6 130 diesel engine, WD6 15 diesel engine and step diesel engine all occupy the mainstream position in Zhejiang province, with an annual output value of 10 yuan, which is the key engine production base in Zhejiang province.
This internship, I stayed in Hangzhou Engine Factory for the longest time, lasting 12 days. I introduced the processing technology of X6 130 diesel engine cylinder block (divided into surface processing and hole processing), the processing characteristics of camshaft hole, the classification and specific application of numerical control equipment, the processing program of crankshaft and the specific working principle of the engine. On the last day, we also visited its casting department. I visited its casting production process. During my internship in this factory, I deeply realized the practical role of CNC machine tools in production and the urgent need for CNC machine tools and CNC talents in society at present. However, for some important CNC products, such as CNC lathes, milling machines, high-speed and high-precision CNC machine tools, we cannot rely too much on imports.
After nearly a month's internship, I really reached the front line of the machinery manufacturing industry, and learned about the development status and development trend of China's manufacturing industry. In the new century, science and technology will develop at a faster speed and be more closely integrated into various fields, which will greatly broaden the development direction of machinery manufacturing.
Its development trend can be summarized as "four modernizations": flexibility, agility, intelligence and informationization. Even if the process equipment and process route can meet the needs of producing various products, they can also meet the needs of rapid changes of processes and products, so that they can coordinate flexibly with the environment, make the production market shortest, make the manufacturing of enterprises flexible and agile, greatly reduce the material consumption and manpower consumption in the manufacturing process, and pursue highly automated production.
Of course, the four development trends of machinery manufacturing industry are not separated, they are organically combined, interdependent and mutually promoting. At the same time, due to the continuous progress of science and technology, there will be new development directions. What we saw before was the development of machinery manufacturing industry on its own line. But as a part of social development, it will also be more widely integrated with other industries. The importance of machinery manufacturing industry in the 2 1 century is manifested in its globalization, networking, virtualization, intelligence and green manufacturing coordinated with environmental protection. It not only liberates human beings from heavy physical labor, but also liberates human beings from tedious mental work such as calculation and analysis, so that they have more energy to engage in high-level creative labor, intelligently improve flexibility, and make the production system have more perfect judgment and adaptability. Of course, all this needs further efforts from all of us. Practical purpose
Combine theoretical knowledge with practice, cultivate innovative spirit of daring to explore, improve practical ability, strengthen social activity ability, and learn seriously, so as to lay a solid foundation for future professional practice and work.
Unit profile
Chengdu yachuang machinery manufacturing co., ltd is a joint-stock enterprise integrating investment precision casting and numerical control machining. Founded in 1988, the company is located in Chengdu Shuangliu Jiaolonggang Industrial Zone, covering an area of15000m2, with a building area of 8500m2, fixed assets of more than 50 million yuan and more than 260 senior technicians and managers. At present, the company has the production capacity of mold design and manufacturing, investment precision casting and high-precision processing of products.
The company has always carried out the business philosophy of "scientific and technological innovation, honesty, customer first and pursuit of Excellence" and established a perfect and scientific management system. In quality management, the company strictly implements the ISO900 1:2000: 2000 system; In terms of production management, the company fully implements lean management ideas and unswervingly and effectively implements 6S management requirements; In information management, the company fully and effectively uses Kingdee's ERP system; In terms of basic management, the company implements the management concept of "getting things done every day, managing everything every day".
The company has two entity production units: investment foundry and machinery factory. The precision foundry has two advanced precision casting production lines with complete testing equipment, with an annual production capacity of 65,438+0,000 tons of precision castings. The machinery factory has more than 80 sets of ordinary and high-precision hosts and equipment, and has the ability to design and manufacture drawings, process materials and comprehensively produce large pieces.
Excellence and the pursuit of Excellence are our constant pursuit; Integrity management and win-win with customers are our business philosophy; Industry serving the country and the people is our ideal; A century's development and a foothold in the world are our goals.
Practical process
1) Safety first. For any machinery factory, safety is always the most important, so under the guidance of the internship teacher, we first carried out some safety education, as well as safety matters and matters that should be paid attention to during the internship. For example, when entering the processing workshop, sandals are not allowed to enter the factory; Pants must be worn when entering the factory; Smoking is prohibited in the factory, clothes are not allowed to open after entering the factory, coats are not allowed to hang on the body, and backpacks are not allowed to enter the factory; People should not pile up in factories and stand on the main road of production; Don't press the button or switch without the permission of the intern teacher;
2) blank selection. First of all, we came to the original parts blank processing workshop. Under the guidance of the teacher, we learned the following knowledge: parts are generally processed from rough embryos. Under the existing production conditions, the blank mainly includes castings, forgings and stamping parts. Casting is a part blank obtained by pouring molten metal into a prefabricated mold cavity, cooling and solidifying. In general machinery, the weight of castings accounts for more than 50% of the weight of the whole machine, which is the main source of blank parts. The outstanding advantage of this casting is that it can be the blank of various parts with complex shapes, especially the blank of parts with complex cavities. In addition, the cost of castings is very low. According to the teacher who instructed our internship, this is the main way for our factory to make blanks. However, its disadvantages are that in its production process, there are many processes, the quality of castings is difficult to control and the mechanical properties of castings are poor. Forging is the use of impact or pressure, the heated metal blank produces plastic deformation, thus obtaining the blank of the part. The structural complexity of forgings is often less than that of castings. However, the internal structure of forgings is good, so they have good mechanical properties. Therefore, the blanks and stamping parts used to manufacture important machine parts and tools that bear heavy load and impact load are made by plastic deformation or separation of metal plates with punches and special dies, thus obtaining the car body. Stamping is usually carried out at room temperature. Stamping parts have the advantages of light weight, good rigidity and high dimensional accuracy. In many cases, stamping parts can be directly used as parts.
3) Processing workshop. When I came to the processing workshop, my first feeling here was that it was too big. The workshop is divided into five parts: turning, milling, fitter, NC machining and welding, covering almost all aspects of mechanical processing. There are about five or six hundred people working in different places at the same time. Although we also have metalworking practice in school, we have made some parts and have a certain understanding of machine tools, but we are really processing parts in that kind. There is a big difference. First, the machine tools in our school are of a certain age, and there are few newly processed machines in recent years. Second, in terms of speed, our processing speed is too slow. The time it takes us to process the same part is about five or six times that of these processing masters, and it is impossible to carry out industrial production at all. In the process of understanding the processing workshop, I have a deeper understanding of some machining processes; Blank-scribing-planer (technically leaving machining allowance)-rough turning-heat treatment, trimming-semi-finishing of lathe-grinding-gear machining-quenching (tooth surface)-grinding surface; Processing technology of gear parts: rough turning-heat treatment-finish turning-grinding inner hole-grinding core, shaft end face-grinding the other end face-hobbing-pliers teeth-shaving-countersunk keyway-fitter-finishing.
4) Assembly workshop. Any machine is assembled from one part after another. In the assembly workshop, about 100 people are collecting assembly parts, packaging them and sending them to the storage factory. In this workshop, the master first releases the collected parts to facilitate assembly, and determines the assembly method, assembly sequence and required tools. Then clean the parts to remove oil stains, rust and oil stains, and ensure that the surface of the machine is clean and beautiful after assembly. After the product is assembled, all aspects of the parts should be debugged to check the flexibility and sealing performance of the moving parts, and then transferred to the box for storage.
5) Quality assurance, sales and after-sales service
Finally, we came to the quality inspection department. They mainly randomly select their own products, record their data, and return to the processing workshop to correct and modify the products, so as to better produce and store qualified products. As for the sales part, according to the introduction of relevant sales departments, due to the order-based production adopted by enterprises, sales are promising all the way.
Mechanical manufacturing experience
After nearly a week's internship, I really got in touch with the front line of the machinery manufacturing industry, and learned about the development status and development trend of China's manufacturing industry. In the new century, science and technology will develop at a faster speed and be more closely integrated into various fields, which will greatly broaden the development direction of machinery manufacturing.
In the future, mechanical manufacturing will develop towards the "four modernizations", that is, flexibility, agility, intelligence and informationization. Even if the process equipment and process route can meet the needs of producing various products, they can also meet the needs of rapidly changing processes and products, so that they can coordinate flexibly with the environment, shorten the time for products to be brought to market, make the manufacturing of enterprises flexible and agile, greatly reduce the material and human consumption in the manufacturing process, and make them highly automated.
Of course, the four development trends of machinery manufacturing industry are not separated, they are organically combined, interdependent and mutually promoting. At the same time, due to the continuous progress of science and technology, there will be new development directions. What we saw before was the development of machinery manufacturing industry on its own line. But as a part of social development, it will also be more widely integrated with other industries. The importance of machinery manufacturing industry in 2 1 century lies in its globalization, networking, virtualization, intelligence and green manufacturing coordinated with environmental protection. It not only liberates human beings from heavy physical labor, but also liberates human beings from tedious mental work such as calculation and analysis, thus having more energy to engage in high-level creative labor, intelligently improving flexibility and making the production system more perfect.
The experience of this internship
What you get on paper is so shallow that you never know what you have to do. "In my short internship, I learned more about the relationship between people at work and analyzed the characteristics and methods of people by watching, asking and doing it myself. I deeply felt the superficiality of my knowledge and the lack of professional knowledge in practical application. Once you come into contact with reality, you don't know how little you know, and you really realize the meaning of "endless learning".
Our education should be more integrated with social practice, adopting a school-running mode of combining theory with practice, so as to combine classroom education with social practice, summer practice with peacetime practice, and the breadth and depth of social practice. Only by combining what you have learned and used in class, summer vacation and practice can you master it more completely.
"A journey of a thousand miles begins with a single step", which is a short and substantial practice in the past week. I think it has played a very important role in my stepping into the society and is also of great help to my future work. More importantly, consult others with an open mind, abide by organizational discipline and unit rules and regulations, and communicate with people in a civilized manner. Some basic principles of life should be conscientiously implemented in real life, and good habits should be constantly cultivated in real life. The experience, good habits and knowledge of leaders and colleagues will also be a great asset in our lives. This practice made me affirm the truth of being a man in advance. To understand the truth of being a man, how to get along with others is a basic problem in modern society. For a person who is about to enter the society, there are many things to learn. They are the best teachers. As the saying goes, "A threesome must have a teacher", and we can learn a lot from them.