For security reasons, the elders' dormitories are located in the courtyard of the Joint Processing Center. [Full text reading] In addition, the equipment of the joint processing center has not been used by naturalized migrant workers until now - to operate this equipment, at least workers must have a foundation in old time and space high school mathematics, and at most, they must be B diploma holders. Can't play well.
Zhan Wuya's dormitory is a suite, with a small bedroom inside and a living room and studio outside. In fact, it is more of a conference room. Factory veterans often discuss technical issues here. In the middle of the house is a large Eight Immortals table, surrounded by wicker chairs and benches. There is a bench against the wall, with a vise fixed on it. There is also a locked tool cabinet - inside are his personal tools.
After the siren sounded at six o'clock in the afternoon, Zhan Wuya first checked the fire protection and safety conditions of the joint processing center workshop and the pipe products warehouse, making sure that the power supply had been cut off and all the doors and windows were locked. This is a daily routine. As the manufacturing director and director of the General Machinery Factory, he holds the keys to these two places and is directly responsible. Zhan Wuya knew that there was little danger of being destroyed by force. What he feared most was safety accidents, especially fires.
After everything was in order, he asked his female apprentice to go to the Elders' Cafeteria to buy supper and drinks for the night, and prepare to work at night so that everyone could continue to work on the problem - the female apprentice was actually his maid. Zhan Wuya felt that he had been living in the factory for a long time, and it was useless. It's no use having a maid, so just stay with me and work as an apprentice. If you can't do fitter, you can make a lathe or something.
Taking advantage of the fact that everyone hasn’t come yet. Zhan Wuya took several damaged chains taken from the workshop to the workbench outside, turned on the workbench light and carefully inspected the fractures of the chain. I looked at it with a magnifying glass for a while. He himself is engaged in heat treatment. Although he does not understand metallography, his years of experience have allowed him to find some skills in this area. After studying the fracture for several minutes, I felt that it was still a problem with the stress of the material.
After a while everyone came and looked at the broken chain link again and again. Discuss how to increase the strength of the chain. It should be said that this time the Machinery General Factory was determined to take down this link in the industrial chain. Zhan Wuya personally engaged in heat treatment - a large heat treatment furnace was specially built. Steel obtained from the Ministry of Metallurgical Industry is also the best product that steel mills can produce.
But the results were still unsatisfactory. Everyone gathered around the large number of chains and looked at them again and again, adding a few words to the discussion from time to time. Liang Xin took the vernier caliper, measured the chain links one by one, and wrote down the data on a piece of paper. Sun Li checked whether there were any scratches on the chain section by section... Everyone was busy studying the chain in their hands from all angles. There was no discussion before an opinion was formed - the hypothesis also requires physics. evidence as basis. Zhan Wuya's female apprentice added tea to them, and from time to time helped light the fire and empty the full ashtrays.
By midnight, everyone finally came up with a unified technical analysis conclusion: the chain is unevenly stressed. The main cause of the problem is manufacturing process issues.
The process flow of chain manufacturing in the Machinery General Plant is to first forge and shape the blank, then anneal to remove stress, then perform cutting, then normalizing and surface treatment, and finally assembly.
"I just checked many links of chains. The tolerances are not very ideal. Some are large, and the average error in size is still relatively large. According to GB standards, the limit tolerance of chain rings of this size cannot be greater than this. This shows that during the cutting process The prestressed problem in the chain is more serious than we imagined." Liang Xin said, "A small amount of tolerance accumulates, causing concentrated stress on certain links of the chain and eventually breaking."
Sun Li said: "I think it should be processed first and then heat treated. Even if it consumes a few tools, it will be accounted for - after all, we can always solve the problem of tools in the future, and they are not disposable consumables that cannot be replenished after they are used up. In addition, , forging should be left to the arsenal, where the forging machines are larger than here. In such a high-intensity industrial chain, the larger the tonnage of the forging machine, the better."
"We can't solve the problem of manufacturing hard tools on lathes for a while. I don't know if we can finish it before the end of the First Five Year Plan." Zhan Wuya said with a frown. Hard tools require alloy steel materials, especially rare metals such as tungsten, cobalt, tantalum and niobium - these things are not available anywhere. Alloy steel cutting tools have high requirements for metallurgy and processing technology. The hard cutting tools on various machine tools currently used by the Ministry of Machinery Industry completely rely on the old space-time products in stock. They are only used in less demanding processing and cutting. Machinery factory-made ones are used. of carbon steel knives.
Zhan Wuya thought again and again: "This is indeed a reason, but lathes all rely on good tools. Making chains right now is not just about making a few chains. I can't worry about recklessly consuming tools before there are clear qualified hard tools for mass production." I think we should start from three aspects: tolerance control, forging and heat treatment. After cutting, heat treatment is performed to eliminate stress."
The discussion on specific processes and solutions continued until early in the morning, and everyone dispersed after having supper.
Early the next morning, chain manufacturing was resumed. After the chain blanks were completed, they were transported to the Bobu Arsenal and forged on the large forging machine in the arsenal - this is the largest tonnage forging machine owned by the Chuan Chuan Group, and all large equipment of the Chuan Chuan Group. , heavy artillery and ship keels were all forged here.
After forging is completed, the chain is transported back to the factory, where it is annealed in a heat treatment furnace and then machined. However, a tempering heat treatment is performed after cutting to eliminate the prestress generated during processing. Then carry out normalizing and surface treatment. Finally, add the threaded buckle to assemble it into a seamless chain buckle.
"Take it for inspection." Zhan Wuya looked at the completed chain and said, "Do a tensile test."
"I'll host it," Sun Li said.
"Okay, it's our own business to strictly control the situation. We're not trying to fool our customers."
"Of course." Sun Li said, "Let's go to the testing ground."
Several naturalized technicians who had been studying with the class responded, picked up the chains and walked out. The female apprentice handed Zhan Wuya a large enamel cup of tea and a towel. Zhan Wuya drank more than half the cup in one breath and wiped his sweat. Ask the female apprentice to bring some bottles of salt soda for everyone.
"Bring me two more packs of cigarettes"
Several veterans were squatting at the door of the heat treatment workshop smoking, waiting for the test results - no smoking was allowed in the workshop. This was a rule set by Zhan Wuya. The female apprentice quickly brought a few small benches. Although it was mainly naturalized migrant workers who did the work, several elders were there to supervise and guide almost every step, working for two days and two nights. Everyone's eyes are red.
After a short time, Sun Li came back with a smile on his face: "The egg is successful."
Several people cheered and stood up. Zhan Wuya was a little excited and asked again: "How is the test going?"
"We did a tensile test based on the actual working conditions of the dumper, and it passed completely. The tension was increased to 12o% before it broke." Sun Li said, "I think we can do the full machine test of the dumper right away."
"Okay, this time the test has been completed and the process manual has been compiled as soon as possible to start mass production." Zhan Wuya was very excited. Mining chains are an urgently needed product now - large-scale mines almost all use mining chains. With the foundation for manufacturing high-strength mining chains, chain production on many industrial equipment will be overcome in the future.
After the second test was successful, the General Machinery Factory improved the bucket elevator. First, an anti-reversal device with a ratchet mechanism is installed. Bucket elevators are most afraid of power interruption. During the lifting process, one side of the bucket elevator is an ascending hopper filled with materials, and the other side is a descending empty hopper after unloading the materials. After the power is interrupted, the elevator will inevitably reverse due to gravity. As the hopper reverses, the material is discharged to the bottom of the bucket elevator until it becomes full and gets stuck. Since reversal is an additive movement, it is easy to tear off the hopper, causing damage to the equipment.
Modern bucket elevators are all sealed - the purpose is to reduce the dust flying of materials during the lifting and loading and unloading process. For the sake of saving materials, the General Machinery Factory initially omitted this shell when designing the hoist. However, during the test process, everyone felt that it would be better to install it - anyway, an iron shell does not consume much material, but Can significantly reduce dust pollution. Occupational diseases caused by industrial dust cannot be solved by clinical medicine in this time and space. Besides, the dust of iron ore is also iron ore, and when it is sintered, it can be used to make steel.
However, new problems arose after the iron shell was installed. After the seal was discovered during the trial operation, it became difficult to feed and unload the hopper. The hopper was not full and could not be unloaded cleanly. Everyone quickly went to the technical archives to look for the design drawings. After a double check, it turned out that the workshop director of the sheet metal workshop responsible for manufacturing the sealed shell of the elevator had saved the trouble by omitting the suction ducts and vents at the head and bottom of the elevator.
The sealing shell is well made and the sealing is reliable, but it causes a pressure difference during the unloading and feeding process of materials, forming a negative pressure condition inside the sealing shell. Resulting in poor loading and unloading. The vents make the internal pressure of the elevator basically equal to the external pressure, and the function of the suction vents is to prevent dust from overflowing from the vents through suction, thereby avoiding waste and cleaning the environment.
"Lesson, comrades, this is a profound lesson." Zhan Wuya couldn't help reprimanding the elders publicly, but he still couldn't help but beat this example at the work meeting, "A design for industrial equipment, a All kinds of craftsmanship are a direct reflection of the experience and lessons accumulated over many years in industrial society. Anyone who wants to change it cannot change it casually. Such an imprecise attitude will cause trouble in industrial production." ..
