The Rise of Heavy Industry 1980

After talking to Hu, Wang and Zhang continued to examine the design of the CC20-3.

From an engineer's point of view, inspection is not as simple as looking at the eyes, but all about data.

After most of the day's work, Zhang Miaomiao has completed part of the calculation. Using these theoretical data as a basis, some optimization directions can be found.

The first is the wall thickness of the chassis.

The thickness of the CC20-3 chassis is 4.5 mm, and Zhang's calculations show that this value is determined by the bearing housing. Because the monolithically cast chassis contains a bearing housing, the original design had to increase the overall thickness of the chassis in order to meet the stress conditions of the housing.

At the same time, Zhang Miaomiao also reversely calculated the Dolson's chassis, which is also 4.5 mm thick, and its bearing housing is designed in the same way as the CC20-3.

Zhang Miaomiao used the idea of variable curvature fillet to recalculate the position of the bearing seat of the chassis, and found that the thickness of the chassis could be reduced to 4.2 mm.

Reduced from 4.5 mm to 4.2 mm, don't underestimate this measly 0.3 mm.

The chassis is the largest part of the entire gearbox, and thinning down means less weight, which means that raw material costs can be reduced.

In addition to the cost benefits, the reduction in the weight of the gearbox can also achieve the purpose of optimizing the powertrain.

"This alone is not enough to defeat the competition! We have to dig out some other solutions!" Zhang Miaomiao looked scrappy.

"The next point I can break through is the coaxiality of the housing. Wang Chaoyang said.

"Hmm......"

Zhang Miaomiao nodded, she also realized that the coaxiality of the bearing seat was a potential breakthrough.

Because in the calculation of shaft and bearing life, the coaxiality of the bearing seat has a great influence. In the current scheme, because of the integral casting molding, the assembly surface of the bearing seat is processed by machine tooling, and the coaxiality is set to 0.05, which means that the axis distance of the inner hole of a pair of bearing housing cannot be greater than 0.05 mm.

This requirement has reached the limit of processing accuracy of Changhai Agricultural Machinery. Changhai Agricultural Machinery deliberately imported equipment from Italy to be realized.

Zhang Miaomiao knew that if she could improve this accuracy, the overall performance of the gearbox would be greatly improved, but she was not sure if it could be achieved.

"Machining is not the only way to improve accuracy, the quality of the casting is also important. Seeing Zhang Miaomiao frowning, Wang Chaoyang said.

"Oh, I remember, you said last time about castings, reducing internal stress and reducing machining deformation...... But I don't understand it too much...... "Zhang Miaomiao was a little embarrassed.

"If you don't understand, just ask, don't be embarrassed with me. Wang Chaoyang smiled and said, "Let me ask you first, what do you think

is the internal situation after the casting is demolded?" "......" Zhang Miaomiao shook his head

, the casting is iron, what else can be the internal situation?" "Just imagine, the molten iron in the molten state is poured into the sand mold to cool, and the cooling speed must be different, the outer cooling is fast, and the internal cooling is slow, which leads to the casting iron ...... In particular, the interior of the cast iron on the back wall is like a myriad of springs. These 'springs' restrain each other and do not show force to the outside world, but ......

" "But once machining begins and the balance is broken, these 'springs' begin to be dishonest and will lead to deformation, right?"

"

What are the ways to reduce internal stress, I said it last time, do you remember?" Wang Chaoyang asked.

"......" Zhang Miaomiao's cheeks were slightly red, and she shook her head.

"There are two common methods, one is to release the internal stress through long-term natural placement, and the other is to comply with the law of internal stress from the design perspective to achieve the purpose of reducing or even eliminating the internal stress. Wang Chaoyang said.

"Oh, I remember, you did. Zhang Miaomiao said.

"Listen to me later, you can take notes. Wang Chaoyang said.

Zhang Miaomiao glanced at him with slanted eyes, and then flattened her mouth: "Teacher Wang, let me listen to it next time?" "

Don't wait for class, I can teach you at any time." Wang Chaoyang said.

Zhang Miaomiao glared and said, "Teacher Wang is really tireless."

Wang Chaoyang said: "The main thing is that you won't have too much." "

You!"

After getting acquainted with Wang Chaoyang after all, Zhang Miaomiao would occasionally scold him, especially when Wang Chaoyang put on a condescending attitude to educate people, he especially wanted to scold him.

But just like now, the effect is obviously not good, Zhang Miaomiao is very curious, where does this person's self-confidence come from!

"Then according to you, CC20-3 gearbox chassis, which way should be used to eliminate internal stress?" Since it had no effect, Zhang Miaomiao simply continued to talk about business.

"Neither of the above methods is suitable. Wang Chaoyang slowly walked to the center of the office, looked at the CC20-3 chassis and said, "The natural internal stress elimination efficiency is too low and is not suitable for the current situation, and the monolithically cast chassis needs to contain bearing seats and sealing surfaces, and the design method of equal wall thickness is not suitable." "

What then?"

"Internal stress can be relieved by manual means.

"What does this mean?" Zhang Miaomiao became, the more confused she became.

"Don't worry, I'll explain it to you in detail tomorrow. Wang Chaoyang said.

"Why wait for tomorrow?" Zhang Miaomiao thought that Wang Chaoyang was deliberately hanging people's appetites, and she couldn't help but feel a little resentful. Wang Chaoyang smiled, pointed to the sky outside and said, "Because it's too late, it's getting dark, let's go eat first."

Zhang Miaomiao realized that it was already dark.

The two of them simply cleaned up, left the office, and prepared to go to the factory canteen to eat. Zhang Miaomiao's mind was still about optimizing the chassis, and she basically didn't talk much along the way.

As he approached the door of the cafeteria, someone suddenly shouted from behind.

"Brother Chaoyang!" Wang

Chaoyang turned around and found Chen Xianglong trotting this way. This childhood friend, who looked like a beggar when they first met, now changes into a Changhai Agricultural Machinery overalls and looks much more energetic.

Before and after coming closer, Chen Xianglong said hello, glanced at Zhang Miaomiao, and then said respectfully: "Hello sister-in-law." "

Sister-in-law...... Zhang Miaomiao is rigid.

"Brother Chaoyang, you haven't had dinner yet, it just so happens that I haven't eaten either, let's go out to eat together, I'll have a treat! Brother Chaoyang, you have helped me a lot this time, my thank you so much!" Chen

Xianglong couldn't help but pull Wang Chaoyang out, and when he saw Zhang Miaomiao standing in place, he said loudly: "Let's go

, sister-in-law, don't be polite to me!" Zhang Miaomiao is about to explode on the spot, how can she become a sister-in-law in this confusion! Which is your sister-in-law?

Under Chen Xianglong's warm hospitality, Wang Chaoyang and Zhang Miaomiao solved dinner at the noodle restaurant at the entrance of the factory, each with a bowl of Yangchun noodles, a total of three cents, which Chen Xianglong rushed to pay.

Listening to Chen Xianglong's own account, after he entered Changhai Agricultural Machinery, he was assigned to the workshop as a temporary porter, although it was temporary, but he also had an income of fifty yuan a month, and he was in charge of food and housing, which was much better than his previous days of starvation and fullness.

The squad leader with Chen Xianglong is not bad, and after knowing Chen Xianglong's situation, he took the initiative to lend him 20 yuan, so that there is basically no problem with paying his salary next month.

Hearing this, Wang Chaoyang felt comforted, but still reminded: "Xianglong, after having this stable job, you are not allowed

to gamble again!" Chen Xianglong patted his chest and said: "If you gamble again, I will be a bastard!"