Metalworking internship paper

(1) Fitter

On the first day, we all arrived at the metalworking internship base early, waiting for the teacher’s arrangements. Before we started, the teacher moved out a large TV , the video was played for about an hour, and it turned out to be an introduction to some key points of the metalworking internship, including some introductions to equipment and safety guidelines. The teacher repeatedly emphasized: Safety first! This sentence is engraved in the hearts of each of us, so during the week of metalworking internship, we always put safety first, operate strictly according to the regulations, never play around in the workshop, and are careful and careful not to be careless.

During the benchwork internship, we learned that the main contents of benchwork include scraping, drilling, tapping, sawing, filing, marking, etc. What to pay attention to safety, how to use files, saws and other workpieces, techniques, distances, force, etc., gradually gained a certain understanding of benchwork. Fitter is mainly manual operation and uses various tools to complete the processing, assembly and repair of parts. Compared with mechanical processing, the labor intensity is high and the production efficiency is low, but it can complete the work that is inconvenient or difficult to complete by mechanical processing. At the same time, the equipment is simple, so it is still an indispensable and important type of work in machinery manufacturing and repair work. After listening to the teacher's explanation and looking at the graphics, we started working. Take a square piece of iron and make it into a model of a certain shape. The first step is to measure the dimensions on the iron block and draw the lines. This work should not be taken lightly. If you make any mistakes, your parts will not meet the dimensions. What followed was sawing that I will never forget. I originally thought that the saw was just dragging it back and forth, it was no big deal, it was a trivial matter. But in fact, sawing also requires know-how. The sawing process does not always make the hands numb and the eyes twitchy. We must first adjust the direction of the saw kerf and apply force according to the direction of the saw kerf. When starting the saw, we should Use your left thumb to lean against the saw blade to prevent the saw blade from sliding laterally. Push the handle steadily with your right hand. The saw blade should be tilted at an angle to the workpiece, about 10 to 15 degrees. If the starting angle is too large, the saw teeth will easily break. If the starting angle is too small, the saw blade will be broken. The saw teeth are difficult to cut into and may slip and damage the surface of the workpiece. When starting the saw, the reciprocating stroke of the saw bow should be short, the pressure should be small, and the saw blade should be perpendicular to the surface of the workpiece. At the same time, when sawing, hold the saw handle with your right hand and lightly hold the front end of the bow frame with your left hand. The saw bow should reciprocate in a straight line without swinging. When pushing forward, the pressure is evenly applied. When returning, the saw blade gently slides over the workpiece. The reciprocating speed should not be too fast. The pressure and speed should be reduced before the start and end of sawing to avoid hurting the arm and breaking the saw blade. You can also add a small amount of engine oil. After sawing, you still have to file. Filing is also a tiring and painful task, but it is not difficult as long as you master the method.

First of all, you must hold the file correctly. Keeping the file in a straight motion when filing on a flat surface is the key to filing. There are two types of filing force: horizontal thrust and vertical pressure. When the file is advanced, the pressure of the front hand gradually decreases and the pressure of the back hand decreases as the pressure of the back hand increases. When the file is pushed to the middle position, the pressure of both hands is the same. When the file continues to be advanced, the pressure of the front hand gradually decreases and then the pressure increases. When the file returns, no pressure is applied. Pressure, so that our filing will be simpler and more labor-saving.

(2) Machining

After the first two days of benchwork, we had a certain understanding of the metalworking internship, so we started machining immediately. In general, machining requires us to be very serious and cautious, and there is no room for sloppiness. Tools used in machining include: turning tools, boring tools, drill bits, reamers, knurling tools, forming tools, etc. During processing, the rotational movement of the workpiece is the main movement, and the lateral or longitudinal movement of the tool relative to the workpiece is the feed movement. Turning is the most commonly used type of work in mechanical processing. Whether it is mass production, single-piece small-batch production, and mechanical maintenance, turning processing occupies a very important position. Our practice tool is to process something like a screw. Among them, the biggest difficulty is accuracy. The required error is 0.01mm. The most important thing is that the length must be very accurate. If you accidentally process too much and leave no margin, you will have to start over. Control the speed during processing, and the manual feed must be slow and even during finishing. The speed should be low.

The first step in machining is to install the tool. When installing the tool, you should pay attention to the following:

1) Align the tool tip with the top of the tailstock and ensure that the tool tip is at the same height as the axis of the car. The tool holder should be perpendicular to the working axis.

2) The extension length of the tool head is less than twice the thickness of the tool to prevent vibration during turning.

3) Tools should be padded, placed correctly, and clamped securely.

4) After installing the workpiece and tool, check whether there is interference or collision at the processing limit position.

5) When disassembling the tool and cutting, remember to lock the square tool holder first. After installing and positioning the knife, the turning process begins.

When turning the end face, you should check that the turning tool, square tool holder and bed saddle are locked on the bed, and use a small slide plate to adjust the amount of back cutting to prevent the end face from being convex outside and concave inside. Since on the end face, the diameter gradually decreases from the outside to the center, the cutting speed also gradually decreases, and the roughness value is larger. So it is best to cut from the center outward.

Finally, the workpiece is cut off. The general points to note when cutting the workpiece are:

1) The workpiece is generally clamped on the chuck, and the cutting point should be as close to the chuck as possible

2) When installing, the tool tip and the axis of the workpiece The height of the line is the same, and there is a boss left at the non-cutting point. The length of the cutting knife extending out of the tool holder should be as short as possible.

3) Minimize the gap between the moving parts of the skateboard and increase the rigidity of the tool holder so that The deformation and vibration of the workpiece are reduced.

4) Manual feed should be slow and even, and the cutting speed should be low.

(3) Thermal processing

Today is the third day. We no longer communicate at the school’s metalworking internship base. At about eight o’clock in the morning, we took the school bus together and drove to The mechanical processing factory of Gongguan actually went to the factory for actual combat this time. On the way, we saw a large and tiring sign in front of a factory: Entering a factory means giving up all freedom. After everyone saw it, they laughed in unison. Maybe this slogan is a bit ridiculous, but it does emphasize that we must abide by the rules and operate safely.

When we walked into the factory, we saw a lot of large and small machinery and equipment that we had never seen before. The teacher patiently explained them to us one by one. However, due to limited time, he only demonstrated some of the machines to us. Then we learned about electric welding, gas welding, and cutting respectively. Tell us about the importance of thermal processing in modern industry and its immeasurable core position, the advantages and disadvantages of electric welding and gas welding, and the similarities and differences between them. The teacher's patient explanation, coupled with our careful listening, made the entire internship operation The process went quite smoothly. In just a few hours, we understood some basic knowledge of thermal processing and initially learned how to operate it. This gave us a more specific understanding of our profession and also enabled us to We love our profession even more.

Conclusion

Time flies by like a flash, and the week comes to a reluctant end amidst the roar of various machines. The reason why I feel reluctant to leave is that the time is too short. This is the only regret of this internship. I really hope the school can give us more time for internship. Although we were a little tired, we were in pain and happy. Because we learned a lot of useful things. As the saying goes, practice is the only criterion for testing truth. Through a week's metalworking internship, I learned a lot of common sense about work, and also got a tempered will, which was both bitter and happy. This is another valuable asset in my college life, and it is destined to have a lot of impact on my future study and work. Big impact.

Soon we will leave the campus, enter the society, and face employment. I think the employer will not guide us step by step in detail like the teacher, but more of We need to observe and learn by ourselves. Without this ability, it will be difficult to meet future challenges. With the rapid development of science and the widespread application of new technologies, there will be many areas that we have never touched before. Only by daring to try can we make breakthroughs and innovate. Just like the machining and thermal processing we are exposed to, although it is more dangerous, every student is required to operate it and make a finished product. This exercises everyone's courage to dare to try. What the one-week metalworking internship brings to us is not only the operational skills we are exposed to, nor is it just the several abilities that we are required to exercise through several types of work, more of them require each of us to practice according to the practical skills after the internship. To understand and think about one's own situation is the fundamental purpose of this internship.