On the third day of the internship, the students from the Engineering University finally got to see something with a slightly technical content, the engine crankshaft.
In this era, Huanghe's heavy-duty truck products are still mainly mining heavy-duty trucks, so the engines are basically in-line six-cylinder diesel engines, so the crankshaft of the core transmission device is more than 1.2 meters long.
Originally, Zhou Yan thought he could see all the processing technology of the crankshaft.
But after the visit started, Zhou Yan found that his imagination was too simple: the forging and heat treatment before the engine crankshaft processing had been skipped, and the factory did not want the students to see it at all.
A curved crankshaft is hoisted into position using a crane, placed on the machine tool, started up, and processing begins...
"That's it?"
After watching the lively classmates for several days, I felt that my emotions were being played with.
"Paying attention to everything is a lesson!" Zhou Yan smiled and glanced at the crankshaft being cut, then looked back at Lin Junfeng, "Let me ask you a question, where is the most vulnerable position on the crankshaft to be damaged?"
"It should be the shaft shoulder, right?"
The shoulder is the transition area between the connecting rod and the crankshaft. In order to control the overall size of the engine, the shoulder cannot be machined too thick.
However, it cannot be machined too thin, because the shoulder is the place where bending and torsional stress is most concentrated on the crankshaft.
"What is produced here is heavy-duty trucks, and the requirements for the overall size of the engine are not too high. But if you put it in a car, there will be very few in-line six-cylinder engines." Zhou Yan smiled, "With the same materials,
The longer the crankshaft, the lower the maximum torque it can withstand..."
"So there are V6 and V8 engines?"
"V-type engines have relatively low material requirements for crankshafts, and whether it is the crankshaft or the connecting rod, due to structural reasons, the design margin reserved is very high," Zhou Yan smiled, "However, the V6 and V8
The engine block is more troublesome to process..."
After a while, Lin Junfeng came back to his senses and looked at Zhou Yan curiously: "Old Zhou, why are you telling me this?"
"Are we in our class?" Zhou Yan glanced around the engine parts shop and sighed slightly, "Although everyone is studying engines, not many can eventually work in this industry..."
"How is that possible?" Lin Junfeng was a little unconvinced.
"Most of my classmates will go back to their hometowns to work after graduation." Zhou Yan glanced at He Qiulin who was staring at the machine tool in the distance. "Take Lin Zi for example. Although his home is near Changchun, he can get into a car.
The probability of the industry is a bit low..."
"Jita?"
"Well," Zhou Yan nodded, looking at Lin Junfeng with a smile, "in comparison, the engineering majors of universities in mountain cities are relatively weak..."
Lin Junfeng smiled self-deprecatingly: "According to your statement, aren't our professional courses in vain?"
"The professional basic courses we learned, such as engineering thermodynamics, heat transfer, and fluid mechanics, are quite practical!"
"Oh, by the way..." Lin Junfeng suddenly turned around and asked Zhou Yan in a low voice, "How sure are you of the re-examination for the postgraduate entrance examination?"
"Eighty-nine points, as you know, my English is not bad, and I can get some points for interview speaking. There is a teacher in the interview team at Beijing Capital Airlines, I should know..." Zhou Yan smiled and thought for a moment,
"By the way, Lao Lin, if there is an opportunity for you to join an automobile company, the workplace is a bit far from home. Where would you like to go?"
Lin Junfeng was a little confused by Zhou Yan's inexplicable question and replied: "Far from home? Then you have to look where you are!"
“Guangdong or Hunan!”
"Guangdong?" Lin Junfeng's eyes lit up, "Guangdong is fine. My parents both work there. If there are suitable jobs, it will be pretty good there!"
After a while, Lin Junfeng regained his composure, pushed Zhou Yan gently, and asked in a low voice: "Lao Zhou, don't tell me, do you have connections in Guangdong?"
"I can only open the door for you when it comes to work," Zhou Yan nodded with a smile and patted his old friend on the shoulder, "The rest is all up to you!"
In the afternoon, the factory finally allowed a group of prospective graduates to experience a truly technical job: heat treatment.
To be more specific, quenching, more specifically, heating to 850 degrees, oil quenching.
Among the several professional skills Zhou Yangang has acquired, one is steelmaking and the other is machine tools. He is no stranger to steel processing...
As soon as Zhou Yan finished speaking, Zhong Wei, the "Master of Suffering" standing near him, whispered: "Pretend!"
What Zhong Wei didn't expect was that the instructor leading the introduction said with a smile: "What we are seeing now is the heat treatment of the crankshaft. After heating to 850 degrees, the oil is quenched..."
Zhong Wei's face suddenly turned red.
Just when Zhong Wei was feeling embarrassed, the tour guide asked again: "You are all top students from the University of Technology. Can you tell me the role of oil quenching?"
A group of students were dumbfounded, even Xi Dong, who was leading the team, was stunned.
Lin Junfeng, who was next to Zhou Yan now, turned to look at Zhou Yan and gave him an encouraging look...
receive!
"The stability of cold austenite in alloy steel is relatively high, and oil quenching is enough to ensure the occurrence of martensitic transformation; if quenched with water, the internal stress of the steel will be too large, causing cracking and scrapping of the workpiece. Moreover, the cooling speed of oil quenching
It is slower and the thermal stress is smaller, which generally does not cause the workpiece to crack or be scrapped..."
"Correct answer!" The instructor smiled and nodded, thought for a moment, and continued to ask, "This classmate, to ask a deeper question, can you tell me the approximate composition of the crankshaft?"
This is a bit overwhelming!
Zhou Yan raised his head and glanced at the commentator. He noticed something else in the other person's eyes and smiled slightly: "The 35-chromium-molybdenum aluminum used in your factory should be the crappy stuff on the street, right?"
Bad street?
The commentator's face changed slightly, but before he could speak, Zhou Yan continued: "The current international trend in crankshaft materials is to use high-strength ductile iron or as-cast pearlitic ductile iron instead of heat-treated medium carbon alloy steel. The cost is
Cheap, energy-saving, and environmentally friendly..."
The commentator didn't know how to refute Zhou Yan for a while, and just stood there in a daze, speechless.
Zhou Yan's friends secretly gave Zhou Yan a thumbs up...
Just normal operation.
Occasionally speaking out against others is good for your physical and mental health.
In the afternoon, on the way back to his residence, Zhou Yan's friends gathered around Zhou Yan proudly.
"Old Zhou, how do you know so much?"
"Be prepared," Zhou Yan chuckled, "I checked the information before coming here, but I didn't expect that guy to hit the muzzle!"
"This is really..." The friends didn't know what to say.
In order to celebrate Zhou Yan's outstanding performance during the internship, the friends invited Zhou Yan to have dinner at the restaurant in the evening. Although, in the end, Zhou Yan had to pay for it himself...
"Old Zhou, if only I were you, I would leave a deep impression on the factory, and maybe I would have a chance to stay in Huanghe Heavy Truck!"
"Old Yang," Zhou Yan raised his head and glanced at Yang Haisheng, and smiled helplessly, "Huanghe Heavy Truck has been having a hard time in the past few years. Didn't you see that the workers in the workshop all take turns?"
"impossible?"
"How is it impossible?" Zhou Yan said with disdain, "Huanghe Heavy Truck's main focus is heavy-duty trucks. But in recent years, the state has focused on coal safety and controlled production capacity. Coupled with the sudden rise of Shaanxi Automobile Delong, Huanghe Heavy Truck's market share has increased rapidly.
It’s so crowded…”
There is another point that Zhou Yan did not mention, that is, the rising logistics industry has made semi-trailer heavy trucks popular, while Huanghe Heavy Truck's products in the field of semi-trailers are basically zero...
