The combustion chamber receiver is one of the important and key components of the engine, and is also the full life part of the engine. The so-called full life part is from the start of the new engine manufacturing and factory production, and it must be used until the end of the engine's life. It is generally not replaced in the middle.

Such a full-life part will have cracks during the first overhaul. This is not a normal phenomenon. If cracks occur during the third overhaul, it may be acceptable.

Zhang Can also saw the crack and felt a slump in his heart. Zhang Can said, "Boss, this is not normal. This is the first overhaul of the engine."

Li Tianfeng also clicked a little and recalled the engine design in his mind. In Li Tianfeng's opinion, there would be no problem with the design of the combustion chamber receiver.

So, Li Tianfeng asked: "Mr. He, there are 20 engines for turboshaft D engines, and there are 30 engines that have been repaired. Check it out. Is it accidental if there are cracks on the installation side of the combustion chamber receiver?"

Li Tianfeng attaches great importance to this matter and must be investigated clearly.

He Baitao is the technical deputy general manager of Qingshi Manufacturing Base. He Baitao said: "Boss, there are already 28 engines for overhauling. I will check the combustion chamber receivers of these 28 engines immediately."

He Baitao immediately went to check, while Li Tianfeng and others surrounded the combustion chamber receiver and looked carefully. Li Tianfeng even asked for a magnifying glass and looked at it very carefully with the magnifying glass.

After looking at it, Li Tianfeng said: "This should be a fatigue crack. During the use of the combustion receiver, fatigue occurs on the installation side, especially hot and cold fatigue, so this crack appears."

Hu Donghai next to him is the deputy general manager of the production of Qingshi Production and Manufacturing Base. Hu Donghai said: "Boss, what are we doing now? It is definitely not possible to re-weld the combustion chamber receiver."

Repair welding of cracks is definitely not possible. The accuracy requirements for the installation edge are very high. Not only are there precision positioning holes on it, but the flatness requirements for the installation edge itself are also very high. If the welding is repaired, there will be welding deformation, which will affect the accuracy.

Li Tianfeng looked at Zhang Can and said, "Zhang Can, what do you think you should do? How to repair it?"

Zhang Can has not been engaged in technical work for several years, but the technology has not been abandoned. Seeing Li Tianfeng asking himself, Zhang Can said, "Boss, in this case, you can only drill cracks on the edge of the installation."

Li Tianfeng said: "Yes, you can only drill a crack hole. When drilling a small hole of one millimeter at the tail of the crack, the crack will not continue to crack. This is the most effective and simplest way to repair it."

Hu Donghai next to him immediately understood this and nodded.

Not only did the combustion chamber receiver, Li Tianfeng picked up the receiver. After looking at other aspects, he thought to himself, there is no reason, how could there be cracks?

After looking at it, he saw that all other parts were normal, Li Tianfeng didn't believe it. He personally took a micrometer and measured the thickness of the mounting edge of the receiver.

Li Tianfeng said in his heart: "Sure enough, the thickness of the installation edge is beyond the difference, and the thickness design of the installation edge is 4±0.025. In fact, it is about 5 threads thinner."

It turned out that the size was too poor, which should be the main reason for the excessive difference. Zhang Can finally understand it in his heart.

He Baitao was also very efficient and came here soon. "Boss, I checked it all. It was just an accident. The combustion chamber receivers of other engines were all normal, and none of them had cracks."

Li Tianfeng nodded, "The size of this combustion chamber receiver is extremely poor, so there are slight cracks. Mr. He, check it out, why does this receiver have an extremely poor?"

He Baitao soon became clear. He clearly recorded the engine's resume book. When this engine was assembled, the combustion chamber receiver was an extra-difference piece, with an extra-difference in the thickness and size of the installation side wall, but an inspection technician handled it and used it as it was.

Li Tianfeng was slightly dissatisfied and said in a deep voice: "Mr. Zhang, please emphasize discipline and inspect the processing authority of the technician. You can only deal with the excessive difference of general size. For this wall thickness, it is obviously an important dimension. Such excessive difference of dimensions must be submitted to the non-conforming product review committee for processing."

Zhang Can nodded quickly, "Boss, let's send a document to clarify it immediately. In addition, as a classic case, we will post this matter."

Li Tianfeng nodded in agreement. Tianfeng Technology Company has tens of thousands of employees. If management is not strengthened, some things will inevitably occur. In terms of management, especially technical management, Li Tianfeng dare not relax. This incident can be just a case to inform everyone and warn everyone.

The maintenance of aircraft engines is gradually getting on track, and Li Tianfeng often comes to see it. The one who runs the most diligently is the designers of the aviation engine R&D center and the designers of the turboshaft D engine, who often come here.

The purpose of everyone here is to take a look at the various parts of the turboshaft D engine after 3,000 hours of use. Based on these situations, the design and optimization of the turboshaft D engine is designed and improved.

An engine is not designed and improved without designing and shaping. During the years of engine production, manufacturing and use, designers will continuously optimize and improve the design based on the engine situation.

After this, as time goes by and accumulates, this engine will become more and more stable, the design will become more and more perfect, the minor problems will become fewer and the quality will become better and better.

………

Songzhou City, starting from the previous two years, built a huge industrial park. In this industrial park, it is basically manufacturing enterprises, most of which are medium and small mechanical processing enterprises.

Among these, small machining enterprises mainly focus on processing parts, and there are dozens or hundreds of such medium and small machining enterprises in this industrial park.

These machining enterprises not only process auto parts and locomotive parts, but also some enterprises process aviation engine parts.

Among these companies, some companies with certain strength are processing parts for Tianfeng Technology Company and rough processing of some general parts.

Hu Dingwen is the owner of Jinxing Machinery Processing Factory. Jinxing Machinery Processing Factory can only be regarded as a small factory in this industrial park, with more than a dozen various mechanical processing equipment and less than twenty employees.

Recently, Hu Dingwen is very jealous and very confused inside. The reason is that many of the mechanical processing around him are booming, and the reason for the popularity is that he is processing parts for Tianfeng Technology Company.

The profit for processing parts for Tianfeng Technology Company is not very high, but the price is fair, the batch is stable, and the monthly settlement is on time and never defaults on processing fees. Hu Dingwen also wants to process such parts.

However, Hu Dingwen knew that his Venus Machinery Factory could not meet the requirements of Tianfeng Technology Company, so he could only be anxious and envious.

"Lao Hu, how are you doing recently? The benefits are good?"

Hu Dingwen was in his office, thinking about these things, a middle-aged man walked into Hu Dingwen's office. Hu Dingwen looked up and stood up immediately. This was his old acquaintance, the owner of a machining factory next door, Chen Guangquan.

"Mr. Chen, I can't compare to you. You have made a lot of money by processing parts for Tianfeng Technology, so I can only worry."

Chen Guangquan smiled, "It's really good to process parts for Tianfeng Technology Company. Last year, the processing costs settled by our factory from Tianfeng Technology Company reached more than 20 million."

More than 20 million!

Hu Dingwen felt envious in his heart that the output value of his Venus Machinery Factory was less than 70 million or 8 million last year.

Chen Guangquan took Hu Dingwen's expression in his eyes, smiled, and said, "Mr. Hu, we are old friends, don't blame me for not helping you. I tell you that Tianfeng Technology Company recently issued a document to put a large number of parts roughly processed outside for processing. Many machining factories have put all their efforts and tried their best to prepare for processing from Tianfeng Technology Company."

Hu Dingwen's eyes lit up, but soon became dim and he said a little discouraged: "Mr. Chen, this is the case with our Venus, and it may not meet other people's requirements."

Chen Guangquan said: "Mr. Hu, I have an idea, which is to see if you dare to do it and whether you have the courage."

Hu Dingwen said: "Mr. Chen, you said."

Chen Guangquan said: "The document of Tianfeng Technology Company said that enterprises that can handle OEM for them are divided into five levels, namely a, b, d, and e. They all have corresponding requirements. As long as you borrow a little, add a few CNC equipment, and then raise the management and recruit two or three technicians. You can basically meet the requirements of e-level companies and you can get the processing business from Tianfeng Technology Company."

Hu Dingwen hesitated for a while and was very moved, but he thought that it was too great to invest and too much risk.

Chen Guangquan said: "Mr. Hu, don't hesitate. Follow my advice. Last year, Tianfeng Technology's sales reached more than 100 billion yuan. In the coming years, I will be optimistic about Tianfeng Technology. You are still worried about not having a processing business."

Hu Dingwen thought for a while, then gritted his teeth and said, "Okay, I'll go out for a loan this time, I'll go to buy equipment now."

Like Hu Dingwen, there are many small machining factories like Songzhou City. Everyone knows that Tianfeng Technology Company not only issued special documents, but also prepared to take out the rough processing business of a large number of parts. Everyone has made every effort to sharpen their heads and try their best to prepare for processing business from Tianfeng Technology Company.

Tianfeng Technology Company did this not only completely drive the entire surrounding economy, but also won great benefits.

By processing these rough processing businesses for everyone, Tianfeng Technology Company can concentrate its main production capacity and fine-process parts, without the need to spend manpower and material resources on this rough processing without any technical content.

In this way, Tianfeng Technology Company not only saved a lot of manpower and material resources, but also greatly improved its production capacity, and maintained the monthly engine output at a scale of two or three hundred units.

This also frees up production capacity for the future production of turbofan 21 and turbofan 25 engines.

………

Two updates today, the second update is over. (To be continued)
Chapter completed!