Summary of welding personal practice

Welding, also known as welding and fusion, is a manufacturing process and technology to connect other thermoplastic materials such as metals or plastics by heating, high temperature or high pressure. Let's take a look at the personal internship summary of welding for your reference only!

Even with the experience of metalworking practice, it is inevitable that I will be excited and worried when I come into contact with the new practice course of Denso Practice again. I am very excited because I had a relatively relaxed week and learned the long-awaited knowledge. I'm worried, because it's the first time I've experienced this kind of thing, and I'm afraid I can't finish the task well.

However, the week of Denso practice has been spent quietly and happily, and the middle process is really full of fun. There may be individual failures during the period, but this does not affect the overall sense of accomplishment. At the same time, in this internship, I have a deeper understanding of the process of Denso internship.

The full name of Denso practice course is electronic product assembly practice. This course is aimed at our measurement and control specialty. Its main purpose is to learn the production technology of electronic products, know and understand the basic content of electronic technology, understand the identification and testing methods of common electronic components, and master the hands-on operation ability of welding and product debugging through a complete assembly and debugging of electronic products. A kind of routine training for students in the production process of electronic products such as manual welding, assembly and debugging, so as to enrich the knowledge and skills that cannot be mastered in theoretical teaching. At the same time, the knowledge learned from theoretical teaching is applied to practical operation to improve students' knowledge and operational skills, improve their comprehensive quality and lay a good foundation for subsequent courses. During the Denso internship, our main tasks are as follows:

1, learn to identify and correctly use common electrical components;

2. Know how to measure resistance, capacitance, diode, triode, voltage and current with multimeter.

3. Know how to measure resistance, capacitance, diode, triode, voltage and current with multimeter.

4, master the manual welding and assembly technology; Learn and master the methods and steps of making and debugging simple electronic products.

5. Learn the fault analysis and troubleshooting of simple electrical equipment. These tasks run through our whole Denso practice.

The main tools we used during this period are: multimeter: used to measure resistance and judge whether the circuit is open. Iron, tin wire, suction welding torch, tweezers, screwdriver, etc. Of course, the understanding of devices is the most basic. At the beginning of the internship, the teacher did not forget to spend the whole morning telling us.

First of all, the most basic and commonly used component resistance.

Resistance is represented by "r" plus a number in the circuit, for example, R 1 is represented by the number 1. The main functions of resistors in the circuit are: shunt, current limiting, voltage division, bias and so on. Parameter identification: the unit of resistance is ohm (ω), and the unit of amplification is kiloohm (kω), megaohm (mω) and so on. The conversion method is: 1 megohm = 1000 kiloohm = 1000000 ohm. There are three methods to mark the resistor parameters, namely direct marking method, color marking method and digital marking method. Digital standard method is mainly used for small volume circuits such as patch. Color coding method refers to the method of expressing the resistance value and accuracy of resistance parameters with color rings and color points of different colors. As shown in table 1. Four-color ring method and five-color ring method are commonly used in color coding.

The four-color ring method is generally used to mark the common resistors. The meaning of color ring labeling of four-color ring resistor is: from left to right, the first and second color rings represent its effective value, the third color ring represents the multiplier, that is, the number of zeros after the effective value, and the fourth color ring represents the allowable error. Five-ring color coding method is generally used to mark precision resistors. The color scale of the four-color ring resistor means that from left to right, the first, second and third color scale represents the effective value, the fourth color scale represents the multiplier, and the fifth color scale represents the allowable deviation.

Second, capacitance. In a circuit, the capacitance is usually represented by "c" plus a number. Identification method: the identification method of capacitance is basically the same as that of resistance, which can be divided into three types: direct standard method, color standard method and digital standard method.

In addition to the above components, diodes, triodes and inductors are also commonly used. Diodes are divided into anode and cathode, and the anode with black circle at the end of the tube.

Of course, the most commonly used during the internship is the welding of components. Under limited conditions, we mainly weld by hand. In the assembly of electronic products, it is not easy to ensure the high quality of welding, because the quality of manual welding is influenced and controlled by many factors. Therefore, while mastering the theoretical knowledge of welding, we should also master the operating skills of welding skillfully.

The specific operation method of manual welding can be divided into five processes.

(1) In the preparation stage, move the welding head and welding wire to the welding point at the same time.

(2) heating the welding part, and placing the welding head on the welding part for heating.

(3) Put the solder wire on, and immediately put the solder wire in your hand on the welding part after the welding part is heated to a certain degree, so as to melt the solder wire.

(4) Take out the solder wire, and when the solder wire melts to a certain amount, quickly empty the solder wire.

(5) Remove the soldering iron. Remove the soldering iron when the solder diffuses to a certain extent.

Familiar with these basic operations and processes, the rest of the time is manual operation.

The first day: the teacher explained the purpose and task of the practice, demonstrated the welding method, distributed the practice tools in groups, and the students learned the reading and measurement of common components, welding knowledge, and practiced the welding process with universal plates.

The next day: solder a circuit with a universal board, as shown in figure 1, and learn how to burn and write programs with a single-chip burner. After the welding is completed and the test is correct, the single chip microcomputer can be loaded into the program written by the teacher for verification. And gate adopts 74LS2 1. Please refer to the component data sheet for accurate connection. Note: Digit tubes A, B, C, D, E, F, G and dp are connected to P2.0-P2.7 in turn. To be honest, this is the most difficult operation I think. Many people have experienced several failures.

On the third day, everyone sent out four sets of electronic product welding kits for welding and assembly exercises, to understand the working principle of the kits and to weld and debug them. However, perhaps for simple reasons, our group ended in one morning. In the afternoon, the teacher sent us a patch component to practice, and sent us the original version of the next day in advance, so let's get familiar with it first. We practiced nine-way running water lights, voice-activated LED melody lights, electronic lucky dials, and patch component practice boards.

On the fourth day, four sets of welding kits for electronic products were distributed in groups of four people for welding debugging, and the quality of welding kits served as an important basis for scoring this internship. Components include 4-digit electronic clock, 8-way answering machine, infrared proximity switch and tube radio. I chose the infrared proximity switch.

The fifth day: the teacher checks the welding of the test suite, the students demonstrate the work of electronic products on the spot, and the students write the internship report. Students tidy up welding tools and clean the laboratory.

During the whole internship, I completed the assembly of multi-function key control digital tube, nine-way running water light, voice-activated led melody light, electronic lucky dial and infrared proximity switch. Among them, the function of the multifunction key for controlling the digital tube is to press K3, and the digital tube starts to display. Press switch K 1 plus 1, press switch K2 minus 1, and press switch K4 to turn off the nixie tube. The function of the nine-way running water lamp is to connect the power supply, and the LED lamp flashes from left to right. The flicker frequency can be controlled by adjusting the potentiometer. Voice-activated LED melody light, as the name implies, is connected to the power supply, and the LED light flashes with the sound level. Electronic lucky wheel, that is, pressing a switch can produce a random light.

Finally, the most important finished product is the infrared proximity switch, which proves that I scored a lot in the whole internship process. I have a special feeling for this assembled product. It caused my mood to fluctuate throughout my internship. At the beginning, the assembly was successfully completed, and I was very confident in the finished product. Of course, the result didn't disappoint me. I decisively realized the function: turn on the power and the red light is on. When my hand approaches, another green light lights up at the same time, and when my hand leaves, the green light goes out. I am glad to see that the prototype I assembled has realized its function.

However, good things always go through twists and turns. But the next day, when it was officially accepted, my product suddenly stopped working. At that time, my heart was half cold, and I think this time is over. I can't help it. I checked it again and never found it. Finally, I had to break the jar and let the teacher check it. But when I came around, I also found that other students had the same situation, and my mind was balanced. But when the teacher pointed out the problem to us, I suddenly got excited. Such twists and turns have left a profound impact on me.

Through this Denso internship, I learned a lot, not only in my study, but also in my life. In a word, I successfully completed my undergraduate study task, that is, I learned the basic use of soldering iron and was able to complete simple circuit assembly. At the same time, I learned more about the function of each component and strengthened my hands-on ability. But in my opinion, I have also gained a lot in my life.

Through my own assembly, I understand that an electronic device is obtained through sweat, and its intrinsic value is far higher than its appearance. Through the teacher's evaluation of my work, I almost became a negative textbook, which made me understand that you should never underestimate your eyes, or even the most basic skills will not come out. For example, I used to think that my skills were very good and it was easy to meet the teacher's requirements, so I ignored the practice of solder joints. When I got it in front of the teacher, I found that everything was self-righteous. Therefore, in the future study, we should learn lessons, not behind closed doors, but exchange experiences with each other to make up for our own shortcomings. This is my biggest gain!

Finally, Denso practice is not only a discipline, but also a door to life. Studying hard only completes the basic task, and feeling and summing up with your heart is the biggest gain.

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