Chapter 90 The Road is Blue

"It's not that it's inappropriate, it's that I don't know what standard to use. Pen, fun, pavilion www. biquge。 info "Gong Nian Huai folded his hands behind his head, holding his head in deep thought.

"What standard?" The other three looked at each other, could there be any other criteria? Even if the three of them turned into roundworms in the stomach of Gong Nian Huai, they couldn't guess why Gong Nian Huai had other standards.

"What standard has the gentleman always been accustomed to?" Yan Shi blinked a few times and asked cautiously. However, even he could not remember that under the same sky, there was a second standard of weights and measures. Unless this person was not originally produced in the Great Song Dynasty.

"Haha, confused." Gong Nian Huai patted his head, didn't he use it last time when he drew the telescope frame diagram, and now try it again.

Gong Yi Nianhuai once borrowed a ruler from Fang Qiong and compared it with his Huawei P8. The Huawei P8 is 14.5 centimeters long and 7.2 centimeters wide, and one foot in the Song Dynasty is equivalent to about 32 centimeters, which is less than two centimeters shorter than later generations.

A set of such length standards will be used as a length specification for making telescope frames.

But the standard used as a measure of artillery is a bit crude. The inner and outer diameters of the artillery are accurate to the centimeter, which is a joke, and it is necessary to use millimeters.

Gong loses Nian Huai is worried about this millimeter!

Now we can only use mobile phones to compare them with the rulers of the Song Dynasty to convert them to finer scales.

Gong Nian Huai jumped up, ran back to the house, and found the ruler from his backpack, and the mark he had made on it was clearly visible.

"Ruler?" Yan Shi saw the ruler in Gong Nianhuai's hand, and his eyes were confused, this is a very ordinary wooden ruler, is it worth so much attention from him, a little gentleman?

"Sir, can you let Yuan Zhi take a look?" Yan Shi couldn't help but see how different this ruler was.

"Oh, Yan Zuotou," Gong Yi Nianhuai handed it to Yan Shi, people who are engaged in technology have this habit, and they have to see it before they can let go, "Is there a caliper in the courtyard?" ”

"Calipers?" Yan Shi held the wooden ruler in his hand, gently tapped his palm, and kept his eyes on the left and right of Gong Nian Huai.

"And how do you measure the size of the crossbow?" Gong Nian Huai sat down, looked at Yan Shi's expression, and his warm heart began to sink, and the tiles were cool.

"The mold will be issued by the Metropolitan Institute, and we can do it." Looking at the expression, I don't think there's anything wrong with this. The bows and crossbows are made by different capitals according to the uniform size, and some of the smaller ones below can only undertake the work of some small parts that are sewn and repaired.

"Yan Zuotou, come and see, I have made a few marks on this ruler, this paragraph is 7 centimeters ......, well, it means that it can be divided into seven more parts. And in each of them, there are ten points, ah, you know? You've all watched me do something, it's night, you know at night, you can't stare at people! ”

Gong Nian Huai didn't hear the reaction of the three of them, and when he looked up, he saw that the three heads were together, almost covering his head, and three pairs of black eyes were shining on the top of his head.

"Nian Huai, it's so short, and you have to divide it into ten more parts? It's enough to measure the legs of ants, you won't be so boring, right? Meng Zhijing's eyes narrowed into a slit, and he measured what kind of length it would be to divide one centimeter into ten parts.

"Sir, do you need a more precise measurement tool? What kind of ruler is a caliper? "Strict is worthy of being the head of the Academy, although the level is still 108,000 miles away from the standard in the heart of Gong Nian Huai, but the eyes of professionals are still different from Meng Zhijing.

Gong Nian Huai rolled his eyes, wouldn't it, there were vernier calipers in the Eastern Han Dynasty, but no one knew about them in the Southern Song Dynasty? Gong Nian Huai's heart sinked flickeringly, and he didn't know how long it would take to sink before he reached the bottom.

"Yan Zuotou, let me ask you, has your courtyard cast a circular member?" Gong lost Nianhuai no longer had hope, at least it seemed impossible to start casting cannons now.

"Cast. Sir, Yuan Zhi looks at the picture you drawn, it seems to be hollow, which is somewhat similar to the shell of the earth-shaking thunder. Yan Shi leaned down and carefully looked at the outline sketched by Gong Yi Nianhuai. It's just that the earth-shattering thunder is round, and the Gong Nian Huai is drawing a slender tube.

"How can you do it if you don't try?" Gong Yi Nianhuai muttered, anyway, I have to do it sooner or later, and if I do it early or late, I will do it late, so let's start now.

Gong Nian Huai went through the relationship between the ruler and the centimeter in his mind, and marked the size data of the mortar. Regardless of the length of the barrel or the inner and outer diameters, the length of the barrel is a few feet and inches, and the inner and outer diameters are expressed in fractions of inches. What, the data is too small to measure? Then measure the paper.

"Sir, these data ......." Yan Shi looked at the data on the Gong Nian Huai label, a little blind, but fortunately, Gong Nian Huai stared at the beads, and Yan Shi honestly went as a paperweight.

"Tsk," when Gong Nian Huai began to draw a three-dimensional drawing, Yan Nianhuai's mouth was slurping, and the hala was almost flowing to the top of Gong Nian Huai's head.

Gong loses the annoyance of Nianhuai, how can it be like coming to the pigsty, it's endless.

"Sir, sir, --- Sheng, I must teach Yuan Zhi to draw this kind of picture, tsk, tsk, what, three-dimensional picture? Admittedly, admittedly, at a glance, leaping on the paper, as if alive. Tsk," Yan Shi smacked his mouth, flattering words like water in a surging ditch, reluctant to give up day and night.

"Okay, Yan Zuotou, you, don't praise me yet, come and see, can you make it?" Gong Nian Huai straightened up and looked at the three heads lying on the paper in the shape of a turtle, "Be careful, don't drip snot and tears on the paper, it's broken, I won't make up the drawing." ”

"Sir, when will the casting begin?" There was no one else in the strict eyes. Meng Zhijing? Who this person is, uh-huh, I don't know.

Just looking at Yan Cheng's expression, I'm afraid he is regretting why the public loses Nian Huai is not in such a good tone. Otherwise, it is inevitable to throw yourself into your arms. Why? If he doesn't throw himself into his arms, it is not enough to express his admiration for the public loss. This gentleman himself is determined to worship, and he is right. If you learn the same, it's enough to jump sideways.

"So you can cast it?" Gong Yi Nianhuai glanced at Yan Shi, "This hasn't started yet, continue to draw." Gong Nian Huai stretched his waist, leaned down again, and continued the unfinished work of drawing.

This time it was a mortar shell, which was much more complicated than painting a gun barrel. The bullets and shells of later generations were fired, that is, there was a primer.

At present, Gong Nian Huai has not yet made a primer, and he still has to rely on the fire rope to ignite the propellant and push the shell out of the barrel.

Therefore, the key to the mortars of the public is the sealing of the shell and the inner wall of the barrel. Is it okay for the shell to fit the inner wall tightly? No way.

Because when the propellant deflagrates in the barrel, the outer diameter of the shell will expand thermally and get stuck in the barrel. The outer diameter of a typical shell is less than a millimeter smaller than the inner diameter of the barrel. If this is the case, the sealing effect will still be unsatisfactory, that is, there will be air leakage, and the initial velocity of the gun chamber will be reduced, affecting the firing range.

Later mortar shells generally carved several threaded grooves in the centering part of the projectile body. The scientific name for these trenches is called "air-closed grooves".

Because mortar shells are generally loaded by the muzzle, that is, the front-loading gun, relying on its own gravity to slide, at a certain speed to hit the bottom of the gun pin and make the bottom fire on the bullet fire.

If the outer diameter of the mortar shell has a very close tolerance with the inner diameter of the breech, it is difficult to easily and quickly go straight down the barrel when loading.

In order to ensure sufficient gliding speed and firing speed, there must be a certain gap between the mortar shell and the wall of the breech, but the gap can not be too large, and the excessive gap is bound to affect the correct guidance of the mortar shell in the chamber and affect the accuracy, so this gap is determined to be between 0.6~0.8 mm. In order to reduce the leakage of gunpowder gas from the gap, usually in the centering part with the largest outer diameter of the projectile body, several annular grooves are used as gas-closing structures, and the air-tight grooves are mostly triangular, but also rectangular, semicircular and trapezoidal. When the high-pressure gunpowder gas passes through the trench, the speed slows down due to the formation of vortex due to expansion, so that the amount of gunpowder gas leaked is reduced, and according to different efficiency, about 85% of the propellant gas is sealed in the gun chamber, so as to play the role of sealing the gunpowder gas.

"Spindle?" Others dare not speak out to question the public loss of Nian Huai, like Zhang Yan, his identity restricts his right to speak freely, that is, he can't speak casually. And then it's strict, a little gentleman who picked it up, and he hasn't made a big bow yet, how can he say whatever he wants?

Meng Zhijing was not limited by this, he had been staring at the picture for a long time. He knew in his heart that Gong Yi Nianhuai's painting was definitely not a spindle, although it looked very similar. But Meng Zhijing thought about it for a long time and didn't come up with what it was, if people in later generations could still think of rugby. Meng Zhijing can only lean on the spindle.

Of course, the spindle is not so complicated, especially the inside, the whole is hollowed out, and it is also divided into several parts.

"What? Spindle? Gong Yi Nianhuai looked at it for a while, and smiled, "Brother Meng has good eyesight." ”

"What? Nian Huai, what are you doing with a spindle? Isn't this the three-man cannon you are talking about? "Meng Zhijing is a little blind, how can he deceive people in public.

When Gong Lose Nianhuai drew a mortar ** to the three big guys, Meng Zhijing and Zhang Yan were driven away, only knowing that Gong Lost Nianhuai drew a kind of cannon that can be operated by three people, what does it look like, and today is the first time I have seen it.

"Yan Zuotou, you take a good look, can something of this shape be made? This is like casting the shell of the Megatron Thunder. ”

"Sir, this is harder to forge than a thunderbolt." Yan Shi bit his lip, his eyes flashing with a fiery light.

"Can you cast it or can't you cast it?" Gong Yi Nianhuai asked after him.

"It can be cast, of course it can be cast. If Mr. can paint it, Yuan Zhi will go back and recruit craftsmen to start work overnight. "It's almost a pat on the chest.