First, the purpose of production practice
Production practice is an indispensable part of the whole teaching activity and one of the main links of practical teaching. Through production practice, the following objectives can be achieved:
1. Through production practice, students can get practical training and gain more perceptual knowledge, thus increasing their deeper understanding of theoretical knowledge and creating good conditions for future theoretical study.
2. Prepare for studying specialized courses through production practice. On the premise of having finished the basic courses of theory and technology, through production practice, students can understand the actual situation of their major, establish the necessary perceptual knowledge, and lay a good foundation for learning professional courses from practice.
3. Combine theory with practice. Theoretical sources and practice must be tested by practice at the same time. Compared with specialized courses and basic courses, it is closer to actual production and more intuitive. Through production practice, we can better link professional courses with production practice, really learn professional courses well, and flexibly use theoretical knowledge to solve problems in actual production, so as to adapt to a good foundation for future work as soon as possible.
4. Get ready for the future work as soon as possible. Through production practice, students learn about the organization, basic situation, management mode and development prospect of factories, industry research institutes and other units. At the same time, it can better cultivate students' labor skills and innovative consciousness.
Second, the production practice schedule
The internship time spans three weeks (July1August-August 4).
Internship arrangement:
July 18 to July 2 1, assembly workshop of Guilin Air Conditioning Factory;
July 24-July 28: Sheet Metal Workshop of Guilin Air Conditioning Factory;
From July 30th to August 3rd, the cold dispersion workshop of Guilin Air Conditioning Factory;
August 4th, Guilin Central Plaza (visit the underground central air conditioning system).
Third, the production practice place and its introduction
< 1 >, overview
Guilin Air Conditioning Machinery Factory, located in the international tourist city of Guilin, is a medium-sized state-owned enterprise. The former Ministry of Electronic Machinery Industry is a key enterprise that produces air dehumidifiers, air conditioners and other refrigeration equipment, and is a member of the National Refrigeration and Air Conditioning Industry Association. It is also the only enterprise in Guangxi that has obtained the production license of unit air conditioner and air dehumidifier. Our factory was established in August, 1966, located in the center of Guilin, with convenient transportation. The factory has a production area of 49,666 square meters, including 20,236 square meters in luoshan road and 29,430 square meters in the suburb of Hongtouling. The building area is 30,647 square meters, including 29,692 square meters of standard workshop and 945 square meters of office space; The original value of fixed assets was 39.84 million yuan. Guilin Air Conditioner Factory is a diversified group enterprise, with wholly-owned or joint ventures such as Guixing Fan Coil Factory, Radio Special Equipment Factory, Vietnam Superstar Electric Company, Zhejiang Air Conditioner Company, Guixing Air Conditioner Installation Company and Guilin Jingui Hotel. At present, there are 40 employees1person, retirees 109, and 292 employees, including technical secondary school education or above 102.
The factory began to produce air conditioning and refrigeration products from 197 1. After more than 30 years of practice, we have trained a group of professional technical and production business backbones and accumulated rich experience in technology, production and management. Air conditioning and refrigeration products have been serialized, and now we mainly produce more than 80 series products, such as air dehumidifier, constant temperature and humidity machine, unit air conditioner, wall-mounted room air conditioner, air-cooled hot and cold water unit and vehicle air conditioner. Our products have won many national and autonomous region excellent product awards. The enterprise won the first national reputation award of domestic famous brand air conditioners, and was rated as an advanced unit of economic benefit in Guangxi Zhuang Autonomous Region and an advanced enterprise at the autonomous region level for four consecutive years, and passed the ISO900 1 international quality system certification on August, 2004.
After the large-scale technical transformation in the Seventh Five-Year Plan and the Eighth Five-Year Plan, the factory introduced advanced equipment such as multifunctional automatic punch, numerical control automatic punch, pipe bender, complete automatic plastic spraying equipment and testing equipment from Japan and the United States, basically improved the process equipment and processing equipment of air-conditioning and refrigeration products, and the degree of processing automation reached over 85%, effectively improving product quality and production capacity. At present, the annual production capacity reaches 6.5438+200,000 units.
< second >, main products
The products produced by Guilin Air Conditioner Factory are mainly used to adjust the air environment. There are more than 80 varieties in 6 series, including: dehumidifier series, room air conditioners (on-hook series and cabinet series), unit air conditioners (air-cooled cabinet air conditioners, water-cooled cabinet air conditioners, constant temperature and humidity machines and marine air conditioners), automobile air conditioners, hot and cold water units and fan coil units. At present, products are divided into four categories according to their main uses:
1, dehumidifier series
Our factory has been producing dehumidifiers since 1970s. All products adopt brand-name fully enclosed compressors, high-pressure fans and high-efficiency heat exchangers, and the technical level is in a leading position in China. In order to adapt to the change of market environment, our factory has intensified the development of dehumidifiers and enriched the product line. The newly developed vehicle CFZ2.0DC dehumidifier and household environmental protection fluorine-free dehumidifier CFZ0.4D dehumidifier have been put on the market. At present, the dehumidifier series has been expanded to 13 specification, with 22 models.
2, household air conditioning series
Household air conditioners have been produced since 1992, and now 1 1 series products have been formed. With good quality and excellent after-sales service, the products have established a good brand image of Guixing in Guangxi and surrounding areas. Guixing brand household air conditioner was recommended by Guilin Consumers Association 200 1, and Guilin Air Conditioning Machinery Factory was trusted by consumers.
3, medium-sized cabinet commercial air conditioning series
The medium-sized cabinet commercial air-conditioning series produced by our factory refers to air-cooled and water-cooled cabinet air-conditioning products with refrigeration capacity ranging from 20000 kcal/hour to 65438+ 100000 kcal/hour. LD36 water cooler air conditioner won the fourth prize of Guilin Science and Technology Progress in 1998 and the third prize of outstanding achievements of new products in the autonomous region. The Guixing brand air conditioner per unit area produced by our factory was selected as qualified product by the State Bureau of Quality and Technical Supervision, and the qualified product certificate was issued by China Quality Inspection Association, which was incorporated into the 200 1 annual national supervision and spot check qualified product set.
4, special air conditioning series
Special air conditioning series refers to constant temperature and humidity machines, marine air conditioners, automobile air conditioners and various air conditioners with special environmental requirements. This series of products is difficult to form a batch because of the scattered market, but its high technical content fully shows the scientific research and manufacturing technical level of our factory. The marine water-cooled air conditioner developed in 2000 was welcomed as soon as it entered the market. With the development of automobile industry, the market demand for automobile air conditioners is increasing. Our factory seizes this market opportunity, constantly improves and perfects the product quality of automobile air conditioners, and completes the modification and development of products in time. The newly developed KQZN-D 16 (semi-top) automobile air conditioner has been put on the market in batches, and the market prospect is considerable.
Fourth, the internship content
As the saying goes, "I feel shallow at the end of the article, and I don't know if this should be done." If you want to have a deep understanding of things, you must experience them personally, so that you can integrate theory with practice and deepen your understanding of things. So for me, this internship is an opportunity to experience production practice, so I will cherish this opportunity. Personally, first of all, internship is a familiar and unfamiliar word to me, because I have experienced many internships in my student career for more than ten years, but this time it is so different. He will comprehensively test my abilities in all aspects: study, life, psychology, body, thought and so on. It is like a touchstone to test whether I can apply the theoretical knowledge I have learned to practice. It is related to whether I can succeed in this challenging society in the future, and it is also the key to building confidence, so my investment in it is also 100%.
The intense three-week internship life is over, and I have gained a lot in these three weeks. It is necessary to sum up after the internship. First of all, through more than one month's internship and practice, I have learned a lot of practical knowledge. The so-called practice is the only criterion for testing truth. Under the premise of production safety, we experienced the pain and joy of production personally within our power.
The destination this time is Guilin Air Conditioning Factory, which has a long history. Its predecessor was 1966 Guilin Radio Special Equipment Factory, and there was only one in Guangxi. At that time, it mainly produced compressors and related air conditioning equipment. 1986 was changed to Guilin air conditioning plant, which has been used ever since. As a manufacturer with a long history in the air-conditioning industry, its technical ability is certain, so we chose it.
This practice is mainly based on production practice, which is an important practical teaching link for studying industrial engineering, aiming at broadening horizons, enhancing professional awareness and consolidating understanding of professional courses. The practice mode is mainly to experience the production process with the master and understand the production process. The students visited the production workshop and engaged in production with the master.
On the first day of internship, the factory director first emphasized the safety issues and paid attention to the safety regulations that must be observed in the production process, and then told us about the company. Because it was the first internship, everyone was more excited and full of energy. They were divided into three groups, and each group was assigned to the cold workshop, sheet metal workshop and assembly workshop for internship, and each workshop did it. Then changed the workshop in turn. First, I was assigned to the sheet metal workshop. The so-called sheet metal workshop mainly produces and processes the shell of air conditioner. The sheet metal workshop is divided into plastic spraying area, numerical control machine tool area, common machine tool area, cold pressing area and welding area.
The following are the safety technical requirements that should be paid attention to when practicing in each district.
I. Assembly workshop
The assembly workshop assembles air conditioning accessories into machines. Except for some connecting copper pipes, shells and some internal connectors, other important parts of our factory are bought from outside, such as compressors.
The specific production process of this workshop is as follows:
1. Procurement: Collect all parts, components, standard parts and fasteners according to the schedule, enter the work site and prepare all assembly tools.
2. Chassis assembly: Fix the components installed on the chassis firmly one by one according to the drawing, and pay attention to the degree of freedom that should be guaranteed after some components are installed, the installation sequence of all fastening parts and the relative position relationship of each component, so as to ensure the form and position tolerance requirements.
3. Assembly of the second floor and the skeleton: the skeleton is firmly fixed on the chassis by fastening, and the bottom of the second floor is fixed at the corresponding position of the skeleton and screwed.
4. Assembly of heat exchanger: Fix the heat exchanger on the bottom of the second floor and the frame. At this time, pay attention to adjust the assembly size to ensure smooth assembly in the future.
5. Welded pipe: All copper pipes shall be welded by oxygen. The welding shall be firm, the solder shall be uniform, and there shall be no sand holes, cracks and any missing welding phenomenon. Plate changing device, four-way valve and high-low voltage switch should be soaked in water or soaked with wet cloth for cooling. Nitrogen shielding welding is required.
6. try to leak. Nitrogen is filled into the welded pipeline system, and all products are filled with nitrogen with a pressure of 2.4MPa for immersion test. Soak in water for 5 minutes without bubbles oozing out.
7. Inspection: The inspector will be on duty to check to ensure the soaking time.
8. Pressure-stabilized leak test: After the leak test is completed, the effluent enters the work site and stands for 12 hours; Keep the pressure, stabilize the pressure. When the ambient temperature increases or decreases by 65438 0 degrees, the allowable pressure deviation is 3%. It is not allowed to exceed the pressure drop affected by temperature. Otherwise, the work of process "6" should be carried out again, and the water inflow time should be extended to 10 minute. After maintaining the pressure for 12 hours, the system depressurizes to 1.4MPa until it is deflated and vacuumized.
9. Installation of shell: Stick polyethylene soft foam board on corresponding parts according to the requirements of drawings; Then install all parts of the shell one by one, and fix all fans firmly at the same time; Finally, the front panel is positioned and installed before it is removed for the next process.
10. vacuumizing: slowly release the nitrogen in the system after the next step. When the pressure of nitrogen in the system is close to or equal to or greater than this pressure, connect a vacuum pump for vacuumizing, vacuumizing to -0. 1MPa (gauge pressure), and continue vacuumizing for 20 minutes.
1 1. inspection: the inspector will check the quality time of vacuumizing.
12. Filling * * * quality: according to the process requirements, refill the working medium for the system that has completed the previous process, and shut down the work and shut down after reaching the process specified value.
13. Panel installation: The interior of the system shall be cleaned as required, and there shall be no residual dirt and iron filings in the machine. When installing the panel, the overall appearance should be symmetrical, the gaps between the mating surfaces should be evenly distributed, and the fasteners should be firmly fixed; Magnetic steel suction parts should have sufficient suction.
14. withstand voltage insulation test: MS2675 automatic insulation withstand voltage tester produced by Nanjing Wei Min electronic instrument co., ltd is adopted.
(1). Test voltage = rated voltage? 2+ 1000;
(2) Resistance requirements: 200mv ~ 500mv；;
(3) Test holding time: 2 minutes.
15. external cleaning: treatment: the external surface of the machine body is treated, and the external surface and paint surface are required to be free from obvious damage such as bubbles, flow marks, missing coating, exposed primer and undue wrinkles. After cleaning, attach nameplate, label and trademark as required. Machines to be tested after completion.
16. debugging: the general assembly department will carry out debugging according to the process requirements, and the inspector will conduct inspection. When debugging, each unit is required to run continuously for one hour, and all performance indicators meet the standard requirements, which is qualified. After debugging, the moisture in the machine should be removed to avoid rust due to long-term storage.
Two. Sheet metal workshop
I. Plastic spraying area
(A), early manual processing technology
1. prepared
(1). Operators must wear acid-proof and oil-proof labor protection articles and prepare tools for operation.
(2) Take out normal temperature solvents (rust remover and phosphating solution) that meet the technical requirements.
(3) Prepare derusting fluid (phosphating fluid).
A, according to the ratio of solvent to water, put clean water into the corresponding pool in proportion, derusting at-106 and phosphating at-102.
B, adding the solvent into the pool, and fully and evenly stirring.
C. check whether the PH value of phosphating solution meets the requirements.
(4) Useful solutions. Before operation, remove oil stains and some stolen goods floating on the surface of the solution, and check and measure the total amount of the solution at any time. If it is not enough, the same amount of water and solvent should be replenished in time.
(5) Fill the cleaning and bleaching pool with clear water and keep it in a good flowing state, so as to remove rust and clean it after phosphating.
(6) Deliver the workpieces to be processed to the job site, and put small items in the process basket.
2. Rust removal
(1). The treated workpiece is completely immersed in the derusting solution. Note that the workpieces cannot overlap, and the soaking time is 15-20 minutes.
(2) After the parts are taken out of the derusting tank, wipe the dirt and acid residue on the surface with metal cleaning agent. If there is slight rust, polish the rust spots with 600 water sandpaper. If the parts are seriously corroded and there are many rust spots, use a rust hoe to remove the rust.
(3) cleaning the treated workpiece in a clear water overflow pool to completely remove oil slick and residual acid.
3. Phosphate antirust treatment on metal surface
(1). After degreasing, derusting and cleaning, the workpiece can be phosphatized. Completely immerse the workpieces in the phosphating tank for 10 minute, and pay attention to the fact that the workpieces in the tank cannot overlap.
(2) After phosphating, the workpiece must be cleaned in the clear water overflow pool to remove surface attachments and other stolen goods.
(3) After phosphating cleaning, the workpiece should be dried in time. Generally, it is dried in the sun or in a ventilated place, and sometimes it can be dried, that is, it is baked in a drying room at 100℃ for 10 minutes.
check
After degreasing and phosphating, there should be no oil stains and other stolen goods on the workpiece, and the surface should be rainbow or blue-purple, without yellow rust spots.
(2) Pretreatment automatic line technology
(1) preparation
Clean the impurities and oil stains on the surface of the pool, and then start the equipment to see if the heating works normally.
(2) Work
When the temperature of the cleaning agent rises to 35-40℃, turn off four groups of heating pipes, leaving only one group to continue heating. The oven temperature was raised to 100℃, and the running speed of the assembly line was adjusted to 350 rpm. Hang the workpieces on the production line, and use two hooks for each workpiece to prevent the workpieces from rotating. Turn on the spraying switch, and take out the workpiece after cleaning, phosphating spraying, passivation and baking.
(3) check
After cleaning, the workpiece should be free of oil, rust, sand, etc. (If the workpiece is seriously corroded, it should be specially derusted. )
(4) End
After work, the spray switch, oven power switch, production line switch and main power switch should be turned off.
(3) Plastic spraying process
(1) check
1. The pressure of the air compressor should be 0.3-0.5MPa, and the blown compressed air should be clean and dry;
2. The powder spraying room of electrostatic generator and the hanging tools of conveyor belt should be well grounded;
3. Whether the input and output indicator lights of the electrostatic generator are normal;
4. Whether the spray gun nozzle is blocked; Be careful not to blow powder with an air gun.
5. The fluidized bed of powder drum shall not exceed 30P. S.T powder should be kept in 2/3 position of powder barrel;
6. Whether there is a large amount of powder residue on the conveyor belt, the pneumatic belt adjustment table shall not exceed 70P. Science and technology; ;
7. Whether the hook and the transmission belt shaft are in good condition, otherwise floating objects shall be removed in time.
(2) Preparation work
1. Check whether the workpiece to be sprayed is dry and qualified, and remove the dust and stolen goods on the surface of the workpiece;
2. Operators should wear necessary labor protection articles and work shoes with good conductivity, and strictly abide by the requirements of this section;
3. Start the equipment and pay attention to the normal operation of each equipment;
4. Adjust the conveyor belt speed, oven temperature (130- 180℃), the distance between the spray gun and the workpiece and the powder spraying flow rate to make the powder spraying thickness on the surface of the workpiece meet the requirements.
(3) Operation
1. Hang the qualified chemical parts to be sprayed on the conveyor chain in front of the entrance of the nozzle chamber with a hook;
2. The workpiece enters the powder spraying room through the conveyor belt for automatic powder spraying;
3. The operator at the outlet of the powder spraying room should visually check whether there is any missing spraying place on the workpiece, and manually spray the defective part evenly;
4. After the workpiece is baked by conveyor belt, the operator takes off the hook and puts it in order for transportation.
5. After the work, it is required to cut off the power supply, and the air source will clean the workpiece site.
(4)
The surface of the workpiece should be plump and bright, with strong adhesion, smooth, soft color and no defects such as bubble leakage and wrinkling. When checking the coating, you can tap and scrape it with a metal object, and the coating should not fall off completely.
2. CNC machine tool area
(1). Operation steps of numerical control punch
1. Start: check whether the upper and lower dies are tightened, and pay attention to the allowable load strength of the upper and lower dies.