First, the purpose and requirements of internship
Purpose of practice: To understand the general operation process of * * * cable factory, to be familiar with the specific process of cable production, and to learn the daily management of cable factory. Through practice, we can understand the general management mechanism of production enterprises, establish perceptual knowledge of enterprises, and lay the foundation and preparation for entering social work in the future.
Internship requirements:
1. Obey the arrangement and guidance of teachers and enterprise staff, be orderly and polite, and abide by the relevant regulations of the factory.
2. Listen carefully to the staff's explanation and introduction, ask questions modestly in time, and make suggestions politely.
3. Seriously study the relevant knowledge of cable factory, including cable production process, sales process, enterprise management, etc. Summarize your own harvest and experience and write an internship report.
Two. The specific arrangement of the internship process
1. Get to know the general process of * * cable factory and general cable manufacturing in advance by searching information on the Internet.
2. Arrive at the * * cable factory under the unified leadership of the teacher.
3. Listen to the brief introduction of the enterprise staff to the cable factory, and learn about its products and matters needing attention during the visit.
4. Under the leadership of the staff, we visited the cable manufacturing process on the spot and listened to the introduction of the staff, so that we had a more vivid understanding of the specific cable manufacturing process, production equipment, production requirements and matters needing attention.
5. Go back to school collectively and write an internship report.
Text of internship report:
The ultimate goal of learning is application. Only by linking the theoretical knowledge of learning with life practice and applying it to social practice can learning achieve its ultimate goal. The college has always attached importance to practice, advocated practice, and strived to create and provide opportunities for students to participate in practice. So the college organized an internship visit to the enterprise for us this time. Thanks to the "careful arrangement" of the leading teachers of the college, let us know about the enterprise and society in advance.
This time we visited the * * cable factory.
On the day of visiting the internship, it happened to rain heavily, but this did not reduce the students' expectations. In order to integrate theory with practice, have a more specific understanding of the production and operation of enterprises, and have a deeper understanding and understanding of society, everyone earnestly completed this day's internship.
We started early and arrived at our destination-* * cable factory. When I arrived, the first thing I noticed was the lush trees everywhere in the factory. Today, with more and more attention paid to the environment, the greening of this factory undoubtedly left a deep impression on me first. A good working environment is very important. At that time, I thought that creating a good working environment for workers should also be an important aspect of factory management, which shows that the cable factory has an important management concept of people-oriented.
After a while, an enthusiastic worker in the factory gave us a vivid lesson first. He first gave us a brief and vivid overview of the factory, and told us the main products of the cable factory, the main technology and matters needing attention in cable manufacturing, the market and sales of the products, and some management work and management concepts of the factory. Then, he also reminded us of all aspects that should be paid attention to in our next visit. In this unique classroom, in this classroom away from school textbooks and into social enterprises, I really benefited a lot. This class gave me a perceptual knowledge of the production process of production enterprises, specifically the production process of cables, which made an important premise for my next visit. At the same time, this class also made me feel the rigorous style, innovative production guidance, people-oriented management concept and quality service attitude of * * Cable Factory.
However, "seeing is believing", practice produces true knowledge, so it is more important to visit the factory workshop, which is also the main content of our internship. After a class, all of us can't wait to visit the details of the production workshop. Then, we divided into several groups, each led by a staff member of the enterprise, and visited the factory workshop according to the product production steps to understand the cable manufacturing process.
Under the leadership of the staff, we finally came to the "real factory"-the workshop. The first thing you see is a big red banner that says "safety first". Indeed, in any case, safety is always the most important, especially in the production of large equipment and machinery such as cables, and safety issues cannot be ignored. Safety comes from long-term vigilance, and accidents come from instant paralysis. I have seen this civilized slogan in many places in the workshop. The staff told us that the factory always attaches great importance to safety issues in line with the people-oriented concept and ensures that all production work is carried out in a safe environment. Today, more and more attention is paid to management, and people's management ability has also attracted much attention. Enterprises' concern for workers' safety undoubtedly laid an important foundation for the management of enterprises' production and other aspects. Each workshop also has a "green passage" to ensure the safety of our visit; I also noticed that every workshop has fire extinguishers at regular intervals.
The hygiene of the factory is also worth lamenting. No matter where I went, I didn't see any waste paper, any junk that I shouldn't have, or any sundries piled up. Although the factory looks a little old because of its long history, its clean environment makes me feel brand new. Working in such an environment, I think everyone is willing to contribute a little more, everyone will feel comfortable and everyone will do their best.
During the visit, I also felt the company's encouragement to workers, high requirements for quality and the goal of continuous improvement of products, which can be seen from the slogans of civilized spirit posted everywhere. "Improve our own competitiveness and establish a sense of customer requirements", "Quality is in my hands and customers are in my heart" and "continuous improvement is the eternal goal". It is not difficult to see that this cable factory has established a strong market concept, strives to improve market competitiveness with high-quality products, and expands market share through continuous improvement of production technology. The staff also told us that quality control is an important principle of enterprise production, continuous improvement and innovation is an important strategy of enterprise development, and winning the market is their ultimate goal.
During the visit, I learned that the 1 10kV cross-linked cable developed by 1999 * * cable has passed the new product and new technology appraisal (that is, two appraisals) and scientific and technological achievements appraisal jointly organized by the State Bureau of Machinery Industry and the State Power Company, and has been well received by experts. In the same year, 1 10kV XLPE cable was listed by the State Economic and Trade Commission as the second batch of main equipment and products needed for the construction and transformation of urban rural power networks and recommended products by production enterprises. In 2000, 1 10kV XLPE cable won the * * Provincial Excellent New Product Award. The 220kV cross-linked cable developed by the company passed the type tests of the National Electrical Equipment Testing Center and the National Wire and Cable Testing Center respectively in May 2000, and the main performance indexes of the products are higher than the requirements of national standards and IEC standards. In June, 2003165438+1October, it successfully passed the one-year prequalification in Wuhan High-voltage Experimental Research Institute. The passing of the pre-qualification test of 220kV cross-linked cable indicates that the cable production technology level of * * Company has reached a new level. This reminds me of a sentence: product quality is the life of an enterprise. The success of * * Cable Co., Ltd. is not only related to its sophisticated equipment and advanced technology, but also inseparable from its consistent quality management policy of "taking customers as the center, establishing brand awareness, scientific management and innovation and improvement". * * Cable not only introduces sophisticated equipment and advanced technology, but also combines equipment and technology well, plus scientific management and innovative improvement, thus producing high-quality products.
During the whole visit, the staff patiently introduced each production step to us with a positive attitude and patiently answered the questions raised by the students. From his work attitude, we can also peep into the work style of the whole enterprise, that is, positive, rigorous and serious.
Although this internship seems to be a simple visit, it has played a great role in understanding a person. It broadens our horizons and gives us a more specific understanding of things. Through the study of theoretical knowledge, what we know is often only a vague concept, and it is difficult to have a clear understanding and concrete understanding of the thing itself, while practice can make us see the thing itself clearly. Through this internship, I really realized the production process of the enterprise and how to apply the theoretical knowledge learned in the textbook to practice. Looking at the big machines in the workshop and listening to the staff introduce their functions, I found that there is still a big gap between theory and practice, which makes me more aware of the importance of practice and pay attention to it.
Seeing the rigorous and meticulous work of the workers in the workshop, I have always adhered to the spirit of struggle, and I feel the basic qualities that a social person should have. Through practice, we can better understand the difference between school and society, and make psychological preparations for entering the society in the future. Through the efforts of workers, we can see that the competition in society is fierce, and the pressure after entering the society may be incalculable when studying at school. Therefore, the internship also enables us to establish the belief of continuous learning and hard work. Moreover, we should find opportunities to participate in social practice, turn theory into practical action in social universities, and be a person accepted by society. Through practice, you can better cultivate your ability to bear hardships and stand hard work, know how to be a man, and improve your communication ability and handling ability.
Both theory and practice are wings of development. Theory is inseparable from practice, and practice depends on the guidance of theory. Practice is an important part of teaching and an important classroom for students to integrate theory with practice. The college organized this internship, so that we can look at theory and practice from a dialectical point of view. But at the same time, there are some regrets, that is, we can't really understand the essence of enterprise management experience and can't connect with our accounting major well. I hope that in the future practice, under the guidance of professionals, we can go deep into the professional counterpart factories to visit and study, educate the professional scope, professional objectives and professional ideas in combination with the actual situation, lay the foundation and create conditions for us to learn professional knowledge, go deep into the workshop to practice in a certain process or post, and combine the theoretical knowledge we have learned with practical activities such as production to design and conduct scientific research, so as to further deepen, consolidate and improve the theoretical knowledge we have learned and obtain knowledge for production and research. By visiting and practicing, we can further consolidate and deepen the theoretical knowledge we have learned, make up for the shortage of theoretical teaching, improve the teaching quality, and lay a good foundation for the subsequent professional course study and graduation design. Through production practice, contact with society, improve social communication ability, learn from the excellent quality and professionalism of workers' masters and engineers and technicians, cultivate students' professional quality and clarify social responsibility. This internship provided us with an opportunity to learn about factories, enterprises and companies, and enhanced our social practice ability.
Only pay attention to theoretical knowledge, only know how to "talk on paper", you will never go to the real "battlefield", even if you go to the battlefield, you will be vulnerable. In today's society, the competition is more and more fierce, and the practical ability is paid more and more attention. Therefore, on the basis of learning professional knowledge well, we should take part in more internships, link the theoretical knowledge we have learned with practical activities, improve our ability to analyze and solve practical problems, lay a foundation for our future position in society and create conditions for our further development. In a word, this internship made me realize the importance of practice, further consolidated and deepened the theoretical knowledge I had learned, and set the goal of continuous learning, continuous practice and integration of theory with practice. I will seize every opportunity to participate in the internship in the future and look for internship opportunities myself.
Other answers
According to the arrangement of graduation practice in the second semester of grade four, on the one hand, it is to review and consolidate the professional basic knowledge of the first three years, on the other hand, it is also to pave the way for the later graduation design, so that everyone can have a more comprehensive understanding of automation specialty, so this practice is more meaningful than the previous understanding practice and production practice.
On March/0/5, 2007, led by two teachers, Zhang Changsheng, a group of people visited Kunming Cable Co., Ltd. (Kunming Cable Factory). This time, I went to Kunming Cable Factory for internship, and adopted the teaching method of combining lectures with on-site visits to the factory, which overcame the difficulties of short internship time and low internship funds, and successfully completed this internship task. Through this internship, I have a comprehensive understanding of the working objects, problems and solutions of automation specialty in engineering practice. While consolidating professional knowledge, it also increases the sense of responsibility for the industry. During the internship, I also deepened the friendship between my classmates and exercised the team spirit. The professional knowledge and personal feelings of internship are summarized in the following two parts:
I. Brief Introduction of Kunming Cable Factory
Kunming Cable Co., Ltd. (Kunming Cable Factory) is the first electric cable manufacturer in China. Founded in 1936, the first conductor in China was manufactured in 1939. Known as "the cradle of wire and cable industry in China". The company is a national large-scale enterprise, 26 key backbone enterprises in the wire and cable industry and one of the largest and best economic production enterprises in 10, and one of the first enterprises to obtain the right of self-management of import and export and the designated production of industrial military products. At present, it is listed as one of the first batch of Taiwanese enterprises (groups) supported by Yunnan Province.
Figure 1: Main entrance of Kunming Cable Factory
Kunming Cable covers an area of 450,000 square meters, employs 2 100 people, has total assets of 388 million yuan, has an annual production capacity of over 30,000 tons of total conductors, and various power cables 1 10,000 kilometers, with an output value of over 450 million yuan. It can design and produce different types, varieties, specifications and models of wire and cable products according to advanced standards such as GB, IEC and BS and user requirements. Kun Cable 1995 took the lead in passing the IS0900 1 international quality system certification in Yunnan, and successfully passed the IS0900 1 review and replacement in 1998.
"Kundian" brand products produced by Kundian are not only used in special fields such as aerospace and aviation, but also widely used in key projects in China. In recent years, we have devoted ourselves to the research and development of wire and cable products with high temperature resistance, fire resistance, oil resistance, flame retardant, water resistance, low smoke, low halogen and termite resistance according to international common standards and advanced foreign standards, and constantly introduced new achievements and products.
Kundian wire and cable product 18 times won the title of "provincial excellent product", 1994 was recommended as "domestic fine product" by China Quality Inspection Association, 1995 was recommended as "consumer trusted product" by China Consumer Foundation, and 1997 was confirmed as the first batch of famous brand products in Yunnan Province.
Second, the main products of Kunming Cable Factory
1. aluminum stranded wire and steel core stranded wire
2. XLPE insulated power cable
3. PVC insulated power cable
4. Insulated overhead cable
5. Nylon sheathed wire and cable
6. Mine cable
7. Flame-retardant cables for coal mines
Rubber insulated wires and cables up to 8.450/750.
9.450/750V and below PVC insulated wires and cables
10. Prefabricated branch cable
1 1. Local communication cable
12. PTFE insulated wire for aviation
13. Chloroplastic -46 insulated wire for aviation
14. Small cross-section installation line wrapped with tetrachloromethane film
15. Chlorine -46 insulated flexible cord
16. multi-core chlorine -46 insulated chlorine-plastic sheathed cable
17. Plastic insulated control cable
18. Electric submersible pump cable
19. heat-resistant silicone rubber insulated electrical bushing
20. Drag-resistant mobile cable for field use
2 1. 150 degrees and below motor winding leads.
Three, Kunming cable factory bare wire factory production process
The focus of our internship is the production process of Kunming Cable Factory. Engineers from bare wire branch of Kunming Cable Factory first explained the theoretical knowledge of bare wire production technology in detail, and then took us to visit the production workshop.
In the figure below, the voltage of 0- 10V is externally connected to a PLC (analog input), and the input analog signal is converted into a digital signal inside the PLC. After being processed by PLC, it is compared with the standard setting data, and then PLC outputs an analog control signal to adjust the speed of each DC motor. The DC governors connected with the DC motors controlling the wire drawing machine feed back analog signals to the PLC. Specifically, one PLC controls three DC governors and three DC governors control three DC motors. The DC governor is equivalent to the transmitter, and the DC governor feeds back the voltage signal to the PLC. The PLC used in this production line is Omron and Siemens S7-200.
The DC governor changes the armature voltage by changing the excitation, thus controlling the speed of the motor. The wire drawing machine controlled by DC governor draws 9 mm copper rod into 4- 1. 17 mm copper wire for users to use.
DC motor parameters: power: 250KW.
Excitation voltage:180v v.
Rated voltage: 440 volts
Armature current: 600A
Rated speed: 1500 rpm.
Traction machine uses rotary encoder to measure speed, and its control parameters are:
Working rate: 75KW
Excitation voltage:180v v.
Rated voltage: 440 volts
The winder adopts frequency converter to adjust the speed of squirrel cage machine.
In the picture below, the PLC on the left is Omron. From left, the first module is power supply, the second is CPU, and the rest are I/O modules.
The core control of Kunming Cable Factory is tension control, which is to strictly control the speed of the motor so that it cannot be too fast or too slow. When controlling the speed of the motor, it uses a DC controller of 590 euros.
Four. Governor of mainland 590 DC
Figure 2: 590 euro DC governor used by Kunming Cable Factory.
DC governor is a device to adjust the speed of DC engine. Its upper end is connected with AC power supply and its lower end is connected with DC motor. DC governor converts alternating current into two output DC power supplies, one for magnetizing DC motor (stator) and the other for armature (rotor) of DC motor. DC governor regulates the speed of DC motor by controlling the DC voltage of armature. At the same time, the DC motor gives a feedback current to the governor, and the governor judges the speed of the DC motor according to the feedback current, and corrects the armature voltage output if necessary, so as to adjust the speed of the motor again. All the control algorithms in 590 series are completed by the latest high-speed 16-bit microprocessor (single chip microcomputer). The structure of the control software and the working speed of the microprocessor can ensure that all the control loops can be adjusted within the conversion time of the six thyristors in the main circuit, thus ensuring that the sampling time of the current loop is less than 3.3ms(50Hz power supply) or 2.67ms(60HZ power supply), and the speed loop algorithm operation can also be completed within this time to gain advantages.
DC governor can be used for precise speed control and tension control, and is widely used in machine tools, cables, cement, plastics, paper making, steel metallurgy, sheet metal processing and other industries. It is a high-quality product with high cost performance.
Euro590 DC controller is fully digital control, and DC control is stable and reliable.
Has the following functions:
Advanced PI regulation
Magnetic field regulator
Communication ability
Regenerative and non-regenerative modes
Diagnostic function: Digitally display the working state of the whole machine, and latch the first fault.
Built-in functional modules: diameter module, taper module, torque module, speed module and other powerful functional modules.
Figure 3: The engineer introduced us to the DC controller of 590 euros.
The PLC programmer used in Kunming Cable Factory is mainly SIMATIC S7-200 produced by Siemens, Germany, in addition to the DC controller of 590 euros.
Verb (abbreviation of verb) SIMATIC S7-200
Siemens is the largest manufacturer of electronic and electrical equipment in Europe, and its SIMATIC programmable controller is in the leading position in Europe. Its first generation programmable controller is SIMATIC S3 series control system which was put into market with 1975.
1979, microprocessor technology was applied to programmable controllers, and SIMATIC S5 series was produced to replace S3 series, followed by S7 series at the end of 20th century.
The latest SIMATIC products are SIMATIC S7, M7 and C7.
SIMATIC S7-200 system consists of hardware and industrial software, as shown in the following figure:
The appearance of SIMATIC S7-200 system CPU 22X series PLC host (CPU module) is shown in the following figure:
SIMATIC S7-200 series PLC is suitable for automatic detection, monitoring and control in all walks of life and various occasions. The powerful functions of S7-200 series make it possible to realize complex control functions by independent operation or networking.
S7-200 series PLC can provide 8 kinds of CPU and 4 different basic models for your use.
Ucp221has 6 input points and 4 output points.
U CPU 222 has 8 input points and 6 output points.
U CPU 224 has 14 input points and 10 output points.
U CPU 226 has 24 input points and 16 output points.
CPU 22 1/222 has four high-speed counters (30KHz), which are programmable and have reset inputs. Two independent inputs can count up and down at the same time, and two A/B phase incremental encoders with a phase difference of 90 can be connected.
The CPU224/226 has six high-speed counters (30KHz), which have the same functions as the CPU22 1/222.
S7-200 CPU provides pulse capture function for the digital input of each host, which enables the host to capture short pulses less than one scanning period and hold them until the host reads the signal, but the pulse capture is effective only after passing through the filter. In addition, if there is more than one pulse in a given scanning period, only the first pulse can be captured. The following figure shows the pulse capture waveforms in several cases:
SIMATIC S7-200 provides the following convenient functions for all stages of automation engineering projects: hardware and communication planning, configuration and parameter allocation; User programming; Document preparation; System testing, startup and service; Process control; Filing. It is characterized in that:
Adopt a variety of standards
* * * Enjoy data management
Tool system integration
open system
Reusable program segment
Integrated diagnostic function
Figure 4: SIMATIC S7-200 used by Kunming Cable Factory.
Figure 5: The engineer is explaining the structure of the equipment to us in detail.
Six, Kunming cable factory bare wire branch control circuit and main circuit structure diagram.
Figure 6: Kunming cable factory series machines (continuous pultrusion)
All-digital DC drive devices, all-digital AC frequency conversion devices and all-digital AC cascade speed regulating devices with various power capacities produced by advanced control technologies of European and Siemens companies can realize fully automatic and intelligent control projects through PC, PLC, DCS and other control schemes and field bus connections. Products and projects are widely used in metallurgical rolling, building materials cement, power generation and distribution, intelligent buildings, scientific research institutions, paper glass, ventilation and water supply, environmental management and many other fields.
Seven. Concluding remarks
Through this internship, I really realized the importance of integrating theory with practice.
I study automation. I have learned many sets of classic theories in books, which seem easy to understand, but I have never put them into practice. Maybe I will really go to a company's production line before I realize how difficult it is. We have seen many wonderful automation technologies in teachers or books, which seem simple. Perhaps only by visiting them or going into battle in person can we realize our lack of ability and knowledge. During my internship, I broadened my horizons, increased my knowledge and realized the cruelty of social competition. What I want more is to accumulate all kinds of experience in my work and prepare for the future. Graduation practice is over, followed by intense graduation design. I believe that the experience of this field practice will play a great role in graduation project and our future work and study.