In the next two days, the factory allowed engineering students to visit the production of engine blocks.
The first step in engine block production is naturally the casting of the cylinder block.
This time, the Huanghe heavy truck was finally no longer tucked away. The students were able to see the process of wax mold processing, sand molding, and pouring of molten steel.
However, casting is really not attractive to engineering college students who have been playing with sand molds for a day or two.
However, free things are useless if you don’t watch them...
"Lao Zhou, I remember there is a technology in our metal craft textbook, which seems to be called pressure casting. Can it be used in engine casting?"
"Old He!" Zhou Yan turned around and looked helplessly at He Qiulin who had taken notes, "Didn't you see that the textbook also said that pressure casting is suitable for plastics or non-metallic materials with relatively low melting points?"
"The melting point of steel is 1,500 degrees," Zhou Yan sighed. "The cost of manufacturing a pressure pipe that can withstand such a high temperature is much higher than casting an engine block..."
"Oh," He Qiulin nodded sarcastically, but still a little unwilling to give up, "Can the engine block be cast only in sand molds?"
"Absolutely. In order to control costs, even the fourth ring and the third fork use this method!"
After the molten steel was poured into the sand mold, the platform carrying the sand mold began to shake slightly, driven by the eccentric cam...
The purpose of this is very clear to the visiting students, so that the molten iron can fully enter the model.
The next step is to demould and remove the outer sand mold from the completed casting cylinder.
Of course, there are still flaws in the process system of Huanghe heavy trucks. In order to quickly cool down the model, several workers poured cold water on the cylinder block that had not yet been demoulded...
The visiting students were all confused: Is this the so-called Six Sigma product quality control system?
"The Yellow River heavy truck is nothing more than that!"
The instructor in charge of leading the team seemed to feel a little embarrassed, and walked quickly to the workers: "The model has not completely cooled down, why do you pour cold water on it?"
"Isn't this how we usually do it?" The worker said a little unconcernedly, "The model is still less than 100 degrees, what's the matter with pouring some water on it?"
There is only a small difference between excellence and perfection.
The image of the Yellow River Heavy Truck in the minds of polytechnic students, which was not very tall, has become shorter.
After demoulding, flaw detection is required.
Seeing the huge engine block being pushed into the radiographic inspection room, Zhou Yan consciously took a step back.
"Lao Zhou, isn't that the case?"
"Everything is possible!" Zhou Yan made a free advertisement for Mou Ning.
There are indeed national standards for the intensity of radiation for radiographic flaw detection. Under the intensity specified by the national standards, radiation generally does not cause harm to the human body.
For example, the X-ray machine in the hospital will not affect your health as long as you are not tired of working and take the X-ray several times a day.
But industrial X-ray machines are different from medical ones. In order to penetrate steel, the radiation intensity of industrial X-ray machines is hundreds or thousands of times stronger than that of medical ones.
That's all. As long as you follow national standards and take precautions, it's okay...
However, it all depends on people.
Because the higher the ray intensity of the industrial X-ray machine and the stronger the penetration ability, the better the flaw detection effect will be; parts with different thicknesses require different flaw detection ray intensities.
But sometimes, in order to reduce the trouble of frequent operations, flaw detection operators will fix the radiation intensity.
In this way, some rays that could have been shielded by the shielding layer will escape and become invisible killers...
"Vitiligo is still mild. As time goes by, it is not impossible to get cancer..."
After hearing Zhou Yan's statement, everyone quietly pushed back: It involves the capital of the revolution, and there is no room for sloppiness...
"Isn't that true?" After all, there are iron-headed boys in the team, such as Zhou Yan's bitter master Zhong Wei.
It's hard to persuade a damn ghost with good words.
When Zhou Yan was doing equipment installation, he came into contact with many technicians who had radiographic inspection certificates. Quite a few of them had vitiligo. These were experienced drivers who were very concerned about their lives...
After the flaw detection of the cylinder body is completed, there is also an overall size inspection to check whether the overall size of the cylinder body meets the requirements after cooling.
This step should be redundant. The casting shrinkage rate has data that can be queried.
The inspected cylinder block was sent to the production line, where a group of workers holding files removed burrs and flash edges on the cylinder block.
The next step is the mechanical processing of the cylinder body.
Before the operation, technicians have already tested the wall thickness of the cylinder body and written the machining allowance on the processing technology card.
In the cylinder block processing workshop, the students from the Engineering University finally saw the complete turning, milling, planing, grinding, drilling and boring process: the milling machine milled away the excess thickness on the surface, the boring machine bored the outer wall of the dry cylinder liner, and the drilling machine processed the connecting cylinder head and cylinder head on the cylinder block.
Oil pan bolt holes…
In four and a half days, the students from the Engineering University finally figured out how to build the engines they had learned about.
Just when everyone thought they could see the engine assembly on Friday afternoon, Xi Dong, who was leading the team, suddenly announced that everyone should assemble.
Before getting on the bus back to his residence, Xi Dong, the head of the department, delivered a "week summary"...
"It has been a week since we visited the workshop of Huanghe Heavy Truck for internship. During this week, what you saw and heard will have any impact or inspiration on your future work. When everyone goes back
, think about it carefully..."
After Xi Dong gave a long lecture, he turned the topic to "Old Liu" from the engine professional class: "Teacher Liu, please talk about it again!"
"Okay then..." Teacher Liu, who didn't like trimming, smiled and stood on the flower bed rock, "I'll say a few more words!"
“During the practical training of the junior year, everyone has already disassembled and assembled the engine, and already has a general impression of the structure of the engine. After these few days of visiting and studying, everyone must also have an understanding of how the engine is processed.
Next week, we will visit the final assembly of the engine. During the weekend, I hope everyone can process the parts that have been visited and assemble them in their own minds..."
It's a pity that most of the students, as soon as they returned to their residences, put their swords and guns in storage, released their horses to Nanshan, and happily took a tour of Hongzhou City with their friends.
"Lao Zhou, let's go to the city center square in the afternoon?"
"I can't go," Zhou Yan rolled his eyes, "Go by yourself. If you don't want to take the bus, you can ask Squad Leader Qi to drive you there! I have given the car keys to Squad Leader Qi..."
He Qiulin still wanted to win over Zhou Yan, but Lin Junfeng stopped him with a smile: "Lin Zi, this guy will have his retest tomorrow and has to rush to the capital in the afternoon..."
"Oh, sorry, I almost forgot!"
Zhou Yan smiled, closed the laptop on the table, took off the power cord and put it into his bag, then stuffed a few clothes into his backpack and put the bag on his back: "See you later!"
"Take the test well!"
"Bon Voyage!"
After leaving the dormitory, Zhou Yan took a taxi on the roadside, went to the train station, and then took the train to the capital.
At around three o'clock in the afternoon, the high-speed train Zhou Yan was riding slowly drove into the Capital West Station.
After leaving the station, Zhou Yan walked straight along the horse path for a while, and found his Phaeton that had undergone surgery in the parking lot of a hotel.
I walked to the driver's seat and gently knocked on the window...
"Hey, dear, why did you leave the station so quickly?"
