Zhuang Qianding heard this and said with a smile: "Yu Sheng, go and help me get a barrel blank."
Yu Hua nodded and turned around to get the gun barrel blank. Here, Zhuang Qianding came to the lathe with a deep-hole gun drill, put in a three-jaw chuck and fixed it firmly, and then adjusted the coolant and lubricant nozzles to a reasonable level.
Location.
This processing is different from the past. Since the hardness of the deep hole gun drill is exactly the same as the hardness of the gun barrel blank, the drilling operation must be cautious and detailed. The feed speed cannot be too fast and the work must be done slowly and carefully.
Generally speaking, the hardness of the tool must be at least twice greater than the hardness of the workpiece in order to achieve cutting processing. Four times or more is the best, but this does not mean that the tool and workpiece cannot be processed if the hardness is the same. The most common situation is the wear of deep hole gun drills.
It will just be very big.
Drill bit wear is severe and previous processing cannot be performed, which are two completely different concepts.
A few minutes later, all preparations for barrel processing were completed, and the barrel blank was positioned and fixed.
Zhuang Qianding starts the lathe, the deep-hole gun drill on the main spindle rotates at a low speed, and the gun barrel blank placed on the tool rest and tailstock is fed smoothly.
"Zhi!" When the drill bit and the blank made slight contact, a sharp friction sound came out. In an instant, a circle of metal debris appeared again and fell on the workbench. Coolant and lubricant were quickly sprayed on the contact surface to lower the temperature.
Improve lubricity.
Yu Hua stood aside and carefully observed the condition of the workpiece and drill bit.
Because Zhuang Qianding's movements are very delicate and the feed amount is controlled extremely well, there are no machining accidents. The deep hole drill bit feeds in steadily, and circles of metal debris emerge from the drilled hole.
Two centimeters.
Five centimeters.
Eight centimeters.
The machine tool coolant nozzle is adjusted to the maximum pressure state, which continues to impact the contact surface like high-pressure water droplets, lowering the temperature and bringing out metal debris.
High temperature and difficulty in chip removal are the most serious problems in the field of deep hole processing. The advantage of deep hole gun drilling is that the coolant nozzle can enter the hole to perform cooling operations and avoid excessive temperature damage to the workpiece and drill bit.
The entire drilling process is slow and rigorous. As the hole depth reaches more than 20 centimeters, Zhuang Qianding directly adjusts the spindle speed to the lowest gear.
Don't seek speed, just stability.
Time passed by, and when the hole depth reached 40 centimeters, Zhuang Qianding stopped the lathe, paused drilling, and then redirected the gun barrel blank so that the other end that had not yet been drilled faced the deep hole gun drill.
Since the length of the deep hole gun drill is not enough, Zhuang Qianding can only adopt this secondary drilling method. The disadvantage is that if an error occurs, the entire gun barrel blank will basically be scrapped.
"The length of the deep-hole gun drill should be about 1 meter. In this way, a 60-centimeter-long gun barrel can be drilled and formed in one step, thus avoiding secondary drilling." Yu Hua carefully observed the drilling process and analyzed the currently exposed parts.
Record the processing problem in your mind and think about it silently.
The deep hole gun drill is not long enough, which is a problem.
In addition, the insufficient hardness of the gun drill material is also a problem.
Proposing ideas, conducting experiments, recording defects, and finding solutions is the process of scientific research.
The processing of the barrel continued. Thanks to Professor Zhuang Qianding's excellent skills, the secondary drilling accuracy was extremely high. Soon, the last 20 centimeters of the entire barrel blank broke through, and the tolerances for the same axis were extremely small.
Gun holes appear.
After the gun hole was drilled, Professor Zhuang Qianding asked Yu Hua to record the steps and precautions of the entire operation. He used the tool to measure the drilling accuracy. After getting the parameters, he breathed a sigh of relief.
This is the most important step for successful gun hole drilling.
Yu Hua carefully recorded the steps and related data of the barrel processing, and measured the deep hole gun drill. The wear was relatively large, but within a controllable range.
After the recording was completed, Zhuang Qianding immediately replaced the reamer and reamed the gun hole for final finishing.
Finally, the reamed barrel blank has a straight and smooth 7.92mm inner hole.
"Sure enough, it was successful. Although it was time-consuming and labor-intensive, it is much better than being unable to process it."
Zhuang Qianding held this 7.92mm gun barrel, which was as smooth as a work of art, with both hands. He looked at it carefully, admired it carefully, and exclaimed in admiration. Recalling the aggrieved scene, he couldn't help but said: "If I had thought of this method earlier, I would have been better."
We won’t be helpless in the face of these embryonic materials.”
This 7.92 mm caliber barrel is assembled with China's most advanced infantry standard weapon - the Chinese formal rifle.
"Professor Zhuang, this is a problem exposed by this method. The hardness and length of the drill bit need to be solved." Yu Hua nodded, then handed over the laboratory notebook and said to Zhuang Qianding.
"This is not a problem of methods, but a problem of our weak industrial strength. For a long time, the Chinese steel industry has been unable to smelt gun steel. The barrel blanks of the Hanyang-made rifles produced by the Hanyang Arsenal and the medium-sized rifles produced by the Gongxian Arsenal
They were all purchased abroad." Zhuang Qianding put down the barrel of his gun, took the notebook and checked it, nodded affirmatively, and said.
"Do we need to perform rifling processing?" Yu Hua heard this and nodded silently. What Zhuang Qianding said was basically true, and this was the core reason why he had to master the oxygen blowing furnace and electroslag remelting technology.
If you want to make guns and cannons, you must first make materials.
If there are no gun barrel blanks and barrel blanks that meet the performance, make a hammer gun.
"The rifling processing is not urgent at the moment. There is no broach in the laboratory. I am not familiar with this. I will make all these barrels and send them to the Gongxian Arsenal."
Zhuang Qianding shook his head and replied: "This method is adapted to local conditions and the processing efficiency is not low. Without a vertical drill, a single lathe can drill and process at least 10 gun barrel blanks every day. I will use this method
Write three related papers and sign them all as the second author."
"Student, thank you, professor." Yu Hua was startled when he heard this. He did not refuse, but bowed and thanked him.
Since I am a person of true nature, I don’t need anything else, but I have to be the second author of three papers.
This is simply a waste of money, don't be a fool.
The second work is just right for Yu Hua’s current status.
"However, I will still have to take elective courses in the future. Don't really give me a blank paper during the exam."
Zhuang Qianding smiled and joked: "Also, you don't have to hand in your homework. Today's processing method is the best homework for me."
"Students definitely don't." Yu Hua shook his head. How could he not go to class? Although his understanding of mechanical engineering has gradually deepened, it is far from the level of a master.
Only with a high enough academic level in mechanical engineering can Yu Hua engage in research on oxygen blowing furnaces, which is not yet ready.
Looking at the humble and polite Yu Hua, Zhuang Qianding shook his head and said with a smile: "Okay, that's it for the time being. You go back to rest first, and I want to go back and rest too."
…
The experience of processing gun barrels in the mechanical hall is not known to outsiders. Yu Hua's life is still as peaceful as before. He studies discrete logarithms every day, writes encryption algorithms and algorithm password tables, and the progress continues to improve, and is about to be completed.
On this day in mid-June, a major event happened in Beiping City. Xinhua News Agency published a medical book called "The Barefoot Doctor's Manual" by Zhang San. The price was three yuan per copy and the total number of words was as high as 2.6 million.
Character.
Once the Barefoot Doctor's Handbook was released, it immediately caused a sensation inside and outside Peiping. Anyone who is eager for medical resources needs this medical masterpiece, which is like a Confucian classic.
There is no other way. The medical knowledge in the Barefoot Doctor's Handbook is really important. Although Yu Hua originally deleted many drugs and diseases that were not suitable for this era, such as penicillin, antibiotics, insulin, family planning, etc., there are still very many
Various treatments and diagnostic methods for many diseases.
For ordinary people, this is a precious medical resource book. In critical moments, the knowledge above can be used to save the lives of family members.
For doctors and medical-related practitioners, this is simply a medical masterpiece at the Analects level, which can be used as a teaching material to improve their medical skills.
It contains not only traditional Chinese medicine and various prescriptions, but also Western medicine and treatment methods. It contains 2.6 million words of content, which can be read at once, and the gold content is not too high.
The most important thing is that the price of this book is only three yuan.
sensation!
After the release of Barefoot Doctor, it caused an unprecedented sensation.
In a very short period of time, the name Zhang Sanhe's Barefoot Doctor's Manual spread to the ears of hundreds of thousands of people in Peiping. The first batch of 5,000 copies of the Barefoot Doctor's Manual published by Xinhua News Agency were sold out.
Paper is expensive in Beiping!
PS: I’ve updated 10,000 today, and I’m a little tired. This chapter has been specially updated on the 28th. There will be no updates during the day and night. Basically, I have to wait for the 29th. I’m so tired. I’m really sorry.