When NC apprentices have a task system

Chapter 87 Electrical Discharge Machining

After a while, Xu Yang's headache finally disappeared, and he also learned more about EDM.

The original electric spark machine, referred to as EDM.

It is a mechanical processing equipment, mainly used for electric discharge machining.Widely used in the manufacture of various metal molds and mechanical equipment.EDM is a special processing method that uses the electric erosion effect generated by the pulse discharge between the two poles immersed in the working fluid to erode conductive materials.

When performing EDM, the tool electrode and the workpiece are respectively connected to the two poles of the pulse power supply, and immersed in the working fluid, or the working fluid is filled into the discharge gap.The tool electrode is controlled to feed to the workpiece through the gap automatic control system. When the gap between the two electrodes reaches a certain distance, the pulse voltage applied to the two electrodes will break down the working fluid and generate spark discharge.

A large amount of heat energy is instantly concentrated in the micro-channel of the discharge. The temperature can be as high as more than [-] degrees Celsius, and the pressure also changes sharply. As a result, a small amount of metal material on the working surface at this point immediately melts and vaporizes, and explodes into the working fluid. In the process, it condenses rapidly to form solid metal particles, which are taken away by the working fluid.At this time, a tiny pit trace is left on the surface of the workpiece, the discharge pauses for a short time, and the working fluid between the two electrodes returns to the insulating state.

Immediately afterwards, the next pulse voltage breaks down at another point where the two electrodes are relatively close to each other, generating spark discharge, and repeating the above process.In this way, although the amount of metal removed by each pulse discharge is very small, because there are tens of thousands of pulse discharges per second, more metal can be removed, which has a certain productivity.

Under the condition of maintaining a constant discharge gap between the tool electrode and the workpiece, while the workpiece metal is being etched, the tool electrode is continuously fed to the workpiece, and finally a shape corresponding to the shape of the tool electrode is machined.Therefore, as long as the shape of the tool electrode and the relative movement between the tool electrode and the workpiece are changed, various complex profiles can be processed.Tool electrodes commonly use corrosion-resistant materials with good conductivity, high melting points, and easy processing, such as copper, graphite, copper-tungsten alloy, and molybdenum.During the machining process, the tool electrode also suffers loss, but it is less than the amount of workpiece metal removal, and is even close to no loss.

As the discharge medium, the working fluid also plays the role of cooling and chip removal during the machining process.Commonly used working fluids are media with low viscosity, high flash point and stable performance, such as kerosene, deionized water and emulsion.EDM is a kind of self-excited discharge, and its characteristics are as follows: There is a high voltage between the two electrodes of spark discharge before discharge, when the two electrodes are close to each other, after the medium between them is broken down, spark discharge occurs immediately.Along with the breakdown process, the resistance between the two electrodes decreases sharply, and the voltage between the two electrodes also decreases sharply.The spark channel must be extinguished in time after maintaining a short period of time (usually 10-7-10-3s) in order to maintain the "cold pole" characteristics of the spark discharge (that is, the heat energy converted by the channel energy has no time to be transmitted to the depth of the electrode), so that Channel energy acts on a very small range.The effect of the channel energy can cause the electrode to be corroded locally.The method of dimensional machining of materials by using the corrosion phenomenon generated during spark discharge is called EDM.

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It can be said that CNC machining is inseparable from EDM.

At this moment, Xu Yang felt very happy. He never expected that he could learn the technology of EDM by moving a few workpieces. It was really a waste of money.

"Xiao Xu, I'm going out to smoke a cigarette to relieve fatigue, you can watch for a while, if the situation is not right, you can immediately press the emergency stop button."

Yi Tianya patted Xu Yang on the shoulder suddenly and said.

"Okay!" Xu Yang smiled lightly.

"Thanks, I will teach you EDM when I have time."

After Yi Tianya finished speaking, he got into the toilet.

When Xu Yang saw this scene, he just shook his head, because he saw that during the working hours of Donghai Mold Factory, several employees took time to go to the toilet to smoke to refresh themselves every once in a while.

In fact, Xu Yang didn't like this habit. In the morning, Xu Yang wanted to go to the toilet, and someone happened to come out of the toilet to smoke. When he went in, there was a strong smell of smoke mixed with the smell of feces that had not dissipated, which made him He almost choked and vomited.

He swore at that time that the next time he went to the toilet, he would have to wait for a while before the previous one came out, and then go in. The sour taste was too unforgettable.

"Ding! Trigger the task of NPC EDM master Yi Tianya: help to watch EDM. Task completion reward: money +100! Experience +100! Favorability +10! System fault repair +0.1%!"

Xu Yang has become accustomed to the tasks assigned by the system.

It's just that Xu Yang didn't expect that Yi Tianya smoked for so long, and soon finished the first workpiece.

Originally, at this time, Xu Yang had already completed the task assigned by Master Yi, and he could also drink saliva or something.

But when he looked at where the electric spark machine stopped, wasting time, suddenly a bold idea popped up in Xu Yang's heart, that is, to operate it while no one is there?
As soon as this bold idea emerged, it immediately occupied Xu Yang's entire brain, and suddenly he found that he could not control his body anymore.

In the next second, Xu Yang subconsciously picked up the hexagonal wrench as if possessed, removed the processed workpiece, and then fixed another unprocessed workpiece.

By meter!

Score!

Set up the processing parameters.

Power on!
There was no sense of disobedience in the whole process, and Xu Yang came back to his senses after doing all this.

"Wucao, what's wrong with me?"

Xu Yang couldn't help but feel scared when he thought of his unintentional actions just now.

He didn't understand why he would do EDM?
But Xu Yang also had to admit that he seemed to enjoy the fun of doing it himself, as if it was as normal as eating with ordinary people.

With the first one, there will be the second one, and the third one. Xu Yang can't stop now, and the more he works, the harder he works.

It is said that Yi Tianya became addicted to cigarettes, so he had to go to the toilet to smoke one, so as to relieve fatigue and refresh himself.

He didn't do this before, but now the factory is about to close down, and he hasn't paid wages for more than half a year, so everyone has lost the enthusiasm they used to have, and has become more and more lazy and depraved.

Even so, Yi Tianya did not forget the principles of being a machinist, so he asked Xu Yang to keep an eye on the machine to prevent accidents.

Originally, Yi Tianya finished smoking a cigarette and was about to wash his hands and go out, but his wife called, thinking about work but not in a hurry, so he simply chatted for a while, and then walked out of the toilet leisurely.

Just as Yi Tianya came out of the toilet, he suddenly glanced at him casually, and his face changed drastically in the next moment. At that time, his legs and feet were numb and he almost fell to the ground.

That's right.

Yi Tianya happened to witness the scene where Xu Yang did it, which frightened him a lot.

You must know that in Yi Tianya's perception, Xu Yang is just a newly recruited CNC apprentice, a pure newbie who knows nothing.

Therefore, Yi Tianya was very worried about Xu Yang's unauthorized flashlight machining, what if he got hurt?
There are countless work-related injuries in machining, and they are either dead or disabled. There are really too many bloody examples.

Thinking of this, Yi Tianya didn't care about the numbness of his legs and feet, and hurried over. Just when he was about to reprimand Xu Yang, he swallowed the words and couldn't help but gasp.

"hiss!"

　Rejuvenating the country through industry, CNC technology!
　　
　
(End of this chapter)