"None?" Liu Hai looked at the empty workshop in surprise, "Maybe it was moved somewhere else, and the logistics department should have a record!" Let's ask! Liu Hai glanced at Zhong Lin and said helplessly. Let's go back and ask! Zhong Lin was also helpless! The two of them returned to the city, and then to Shenyang! "Comrade, I would like to inquire, it turned out that there was a workshop in the place where we captured the Japanese 240-mm cannon, and there were several lathes in it, where did it go now?" Liu Hai asked the comrades in the logistics database. "I'll check!" The comrades of the information section rummaged through the filing cabinet for a long time and told Liu Hai a piece of news that shocked Liu Hai: after the Liberation War, those heavy artillery pieces were returned to the furnace because they were too heavy, leaving only one as a sample, and the lathes in the workshop were pulled to the steel mill because they were too old and because they were imported from the Soviet Union! The only good news for Liu Hai is that he was only pulled to the steel mill last month, and it is very likely that it has not been returned to the furnace now because the lathe is too big!

Liu Hai and Zhong Lin hurried to the Fengtian Iron and Steel Factory. "Fuck!" Engineer Zhong scolded, "Take everything back to the furnace, why don't you take all the machine guns back to the furnace!" "I'm used to this kind of thing, when I was developing heavy artillery, I finally made heavy artillery and heavy artillery shells and sent them down, and as a result, some bastard chiefs divided the cannon as a rifle, and some guard companies had a 155 heavy cannon!" Bangs smiled wryly and shook his head! "What's the matter, these fools have ruined all the good things!" Engineer Zhong said! "Let's go to the steel mill first and see if it's back, if not, if we don't, if we go back, we'll have to go to the big brother of the Soviet Union!" Bangs said. "The Soviets won't give it to us, because we won't buy them because we built it!" Engineer Zhong said.

Fortunately, when Liu Hai and Engineer Zhong rushed to the steel mill, the steel mill was very difficult to cut because the lathe was too large, so it was piled up at the bottom of the scrap warehouse, waiting for the opportunity to talk about it! "Dig it out!" Engineer Zhong was so anxious that he shouted! Dozens of workers came up and it took a long time to dig out the machine tool! After inspecting it, Bangs found that although the lathe was a little old, it still worked! "Great, this lathe, this is the mechanical milling machine, with which we can cut qualified steel plate groove lines!" Bangs said excitedly. "Hurry, hurry! Pull it back! Engineer Zhong hurriedly called the steel factory to send a car to pull this baby lathe back! Along the way, the bangs were carefully inspected in the car, and then a method of imitation was sketched! "Great!" Bangs think!

After the two of them moved the lathe back, they imitated it according to this Japanese-made milling machine! The experimental base has its own casting workshop, which brings great convenience to the imitation work! Under the guidance of Engineer Zhong, the foundry quickly imitated the sample! Liu Hai looked at the imitation sample, and personally operated two milling machines to cut groove lines on the steel plate! But the result disappointed the bangs, and the cutting effect of the imitation sample and the original product was too different! "Engineer Zhong, what is the reason for this?" Bangs asked. "The manufacturing accuracy of the original product is very high, our precision is not high, and it is a thousand miles away from it! Let's do it all over again! Engineer Zhong said. What should I do, I can't use a ruler to measure this casting, even if I can use a ruler to measure, this accuracy is not enough! Bangs said. Think about it, there's always a way! ”

Just when Liu Hai and Engineer Zhong were at a loss, an old worker in the foundry workshop suggested that the mold should be erected when casting, and then the most traditional hanging wire in China should be used to measure, and the vertical line is the most accurate in what tool to use! When Engineer Zhong heard this, he immediately took the old worker to conduct the experiment together! Liu Hai, Engineer Zhong and the old worker found a lot of practical problems in the actual operation, and the three of them used their brains to solve them one by one, and after four days of hard work, they finally made an imitation at one time! Bangs experimented again, and the results were pleased to find that this method is very effective, although the milling machine made this time is not as fine as the original, but the cutting effect is very close, and it can be manufactured and cut! "It's finally done!" Engineer Zhong said with relief.

But things are not so simple, after the slot wire cutting of the steel plate, the problem of forging forming is exposed again! Forgings are mainly used for load-bearing structural parts. Due to the characteristics of the rocket for one-time use, the proportion of cast integral structural parts is greater than that of other aircraft. Most of the castings are precision castings of magnesium and aluminum alloys, which are generally used as thin-shell components with complex shapes and accurate dimensions, such as the wing surface of small rockets, the cabin of the overall structure and the flap shell, etc., but there is no ready-made mold for this forging, and the mold can only be redesigned according to the appearance of the Soviet-style *! In order to speed up, after applying for the superior, Liu Hai transferred the technical backbone of Fengtian Iron and Steel Plant, and several old workers with mold manufacturing experience to carry out technical research together! After more than 100 tests and failures, Liu Hai and others finally created a qualified mold in accordance with the specifications and appearance of the Soviet-style rocket artillery.

"Master Liu, now we have reached the most rare step!" Engineer Zhong said. "You said sheet metal molding!" Bangs asked. "Yes, there are three methods of sheet metal forming, spinning, rolling and drawing bending" "Although I didn't specifically learn sheet metal forming when I was in Germany, I have heard of it" Liu Hai said "The powerful spinning process can be used to make parts such as solid combustion rocket shells, conical skin of the head and spherical box bottoms. Spinning requires a large spinning force, and a special powerful spinning machine tool is used to add a spinning force of hundreds to thousands of knewtons to the point surface where the rotary wheel, plate and mold tire are in contact, and the metal material is strongly extruded to make it flow thinner. For example, a blank with a thickness of four millimeters can be spun into a workpiece with a thickness of one millimeter at a time, and the error is within 0.5 millimeters. The surface finish of the spinning parts can reach the level of seven, and the strength of the material can also be improved" "I didn't expect Master Liu to know this, amazing!" Engineer Zhong looked at the bangs approvingly! But the problem is that we don't have such a good spinning machine! Bangs said.

"There is also a method called stretch bending, which we should be able to use other methods to replace the ready-made machine!" Engineer Zhong said: Stretch bending forming includes stretching and bending processes. There are special stretch bending forming equipment such as skin drawing machines and profile stretch bending machines, etc., which are used to manufacture sheet and profile parts with large surface and profile dimensions. When stretch bending forming, the end of the plate or profile blank is clamped with a chuck, and the material stress reaches the yield limit in the pre-stretching and bending is carried out according to the male mold, so that all the inner surface of the blank is attached to the male mold, so as to improve the accuracy of the part. The key to the stretch bending process is to prevent the part from breaking due to excessive tension! "We can strengthen the forging press, and then change it, and it is estimated that it can be replaced!" Engineer Zhong said. "Don't say it, do it!"

Liu Hai and Zhong Engineer once again entered the busy, using the ready-made forging press to carry out the bending process, after all, these are special tools, want to replace each other, not only to have hands-on ability, but also to have a strong creative ability, in the face of almost a poor and white situation, Liu Hai and Zhong Engineer tirelessly carried out experiments, and six days passed, and finally transformed the forging press into a four-like that can replace the bending equipment! Liu Hai fell asleep on the forging press tiredly, and Engineer Zhong also lay on the toolbox! At this time, the head of the Northeast Military Region, who was extremely concerned about the self-development, came to express his condolences and understand the progress! When the chief came in and saw the appearance of the two people, he stopped the comrades who were going to wake them up, and instructed him to order that the food in the experimental base should have meat every day in the future, and Liu Hai and Engineer Zhong would provide the nutrition of a chicken every day!

"Division Commander Liu, the * on the front line is almost gone, and the * on the Soviet side has been delayed in arriving for a long time, and now... Said the personnel of the logistics headquarters of the experimental base. "Okay, I got it!" Liu Hai said: "How much stock do we have at the moment?" "There are still a few thousand more on the front line, and less than a thousand are left in the logistics warehouse! It's a good thing that no new campaign has been launched now, otherwise it would have been troublesome! Said someone from the logistics department. I can't set the exact time, but there will be at most half a month before the sample comes out, and if it is made on a large scale, it will take at least two months! Bangs said. The head of the headquarters is very anxious and hopes that we can come up with qualified * samples one day sooner! "We'll do our best!" Bangs can only say that, because it really can't be set! In addition, Liu Hai knows very well that rocket artillery is different from artillery, and artillery can also fire burst and fire rapidly, but rocket artillery, a suppressive covering firearm, does not have sufficient logistics support, and it cannot exert its power at all!

"Engineer Zhong, are we now handing over the results that have come out to the steel mill, so that they can copy these lathe tools and tools like this, and when the time comes, the tools and machinery will be guaranteed!" Bangs suggested. "Yes! In addition, I also propose to organize a special production organization for rocket artillery shells, and find a special person to do this to ensure the progress! Engineer Zhong said. Yes, I'll go to the General Logistics Department and ask them to make overall arrangements! Bangs said. Okay, go and come back, I'm finishing the design of a little sweeping, and when you come back, we can proceed to the sheet metal forming process! Engineer Zhong said. Good! I'll be there right away! Bangs said.