Start with the aviation industry

Chapter 49 Welding Tests
"Mr. Wang, Mr. Wang!"

Chief Lei Ke was out of breath and out of breath. He probably ran all the way here, and he looked exhausted.

He rode his bicycle all the way from the field office to the door of the sheet metal workshop, and then trotted in. A fat man weighing more than 180 kilograms, it was difficult for him.

The faulty part of the combustion chamber casing has been cut with a hole of more than 100 in length and width, which is the size of an adult's palm, and the lubricating oil pipe in the second layer of casing can be seen.

Everyone was about to take a good look to see if there were any cracks in the welded parts of the lubricating oil pipe and the lubricating oil hole of the turbine bearing seat. When Director Lei shouted, everyone froze.

What's going on here!
Chief Lei was out of breath!
Wang Tianfang was also slightly taken aback, and asked, "Xiao Lei, what made you look like this."

Lei Ke said in a long way, "Chief Wang Wang, I am an outfield technician from a certain base of our air force called. Another turboprop six engine consumes a lot of oil and needs to be returned to the factory for troubleshooting."

what!
Another engine!

There are already three of them now, and if this one is added, it will be the third one. The faces of the people at the scene changed, realizing the seriousness of the problem.

This is a big deal!
Rare serious quality problem!
Wang Tianfang's face also changed slightly. Perhaps he had guessed that sooner or later the fourth engine would consume a lot of oil, but he didn't expect it to come so soon.

The fourth one!

He suddenly felt invisible pressure, and felt that this matter was becoming more and more passive.

There are a total of twelve combustion chamber casings in this batch, and four of them have already had the same problem. Will the remaining eight have the same problem one after another?

This is very likely, and it is estimated that it will be a matter of time.

The most urgent task at the moment is to come up with a maintenance plan as soon as possible. As long as the maintenance plan is completed, even if a similar failure occurs again, the engine can be repaired quickly after returning to the factory.

Yes, the key is to come up with a reasonable and scientific maintenance plan.Wang Tian thought in his heart.

"I see. Do a good job of coordinating the engine's return to the factory for troubleshooting. As soon as the engine arrives, arrange a test run immediately, and then disassemble it."

Lei Ke said, "Okay, I will arrange everything."

After thinking about it for a while, Wang Tianfang explained, "There are a total of twelve combustion chamber casings in this batch, and there are eight more outside. You can find out which engines are installed on them and where they serve, and pay close attention to these eight. condition of each engine, especially oil consumption.”

"Okay." Chief Lei replied again.

After watching Chief Lei leave, Wang Tianfang said with a slightly solemn expression, "Have you heard that the fourth engine with the same problem may not be long before the fifth or even the sixth engine has the same problem. "

"Comrades, we must come up with a reasonable repair plan as soon as possible. Everyone work hard, and don't even think about rest at noon and night."

Invisibly, everyone felt a huge pressure.

Yes, it is necessary to come up with a reasonable and scientific repair plan as soon as possible, and time waits for no one. In addition, the military is also paying close attention to the progress of the matter.

Wang Tianfang looked at the discarded combustion chamber casing and waved his hand, "It's not too late. Immediately conduct a welding test according to the requirements of the provisional process regulations, and strive for a first-time success."

If the test is successful, then this plan can be used in the repair of the three failed combustion chamber casings, including process methods, welding parameters and so on.

If it is not successful, it will be a little troublesome. It needs to be analyzed, discussed, and then the process method and welding parameters should be adjusted before continuing the test.

If it is not smooth, the process and welding parameters need to be adjusted several times according to the situation of each welding test, which requires a lot of time and a lot of combustion chamber casings for welding tests.

What makes everyone more stressed is that there are only three days left, and there are only four scrapped combustor casings.

In any case, the welding test can only be carried out under pressure at present, and I hope it will be successful once or twice.

The incision has been made, and everyone can see the oil pipe in the second layer of the receiver, and also see this metal oil pipe that is less than the thickness of a thumb, and even see the oil pipe and the oil hole of the turbine bearing seat. Welding parts.

The experienced fitter held a cutting machine and cut a small hole in the welding part. This is the simulated fault part, and the next step is welding.

The welding master has also made preparations, holding the welding torch in his hand, inserting the welding rod through the incision and starting welding.

There was a squeaky welding sound, and the strong light from the welding was so strong that people could barely open their eyes, and everyone turned their heads sideways.

After a while, the welding was completed, and everyone turned their heads.

The welder said confidently, "Leaders, the welding has been completed."

Everyone leaned over one after another and saw the part that had just been welded.

It is worthy of being engaged in aero-engines, and it is worthy of being a high-level welding master. This level simply requires a thumbs-up.

The welding part is very beautiful, very neat, standard fish scale welding.

Perhaps welding fish scale welding is only the most basic requirement among many welders in the sheet metal workshop. The fish scale welding of this master is more beautiful than ordinary fish scale welding.

Everyone looked at the welded part and felt that it was welded well, so Wang Tianfang waved his hand and said, "Carry out dimensional inspection, especially the dimensional inspection of the turbine bearing seat."

This is very important!
After welding, it will not affect the size of other parts, especially the turbine bearing housing. This bearing housing is equipped with turbine bearings and has very high precision.

Two workers jointly lifted the combustion chamber casing to the inspection turntable, which is the highest-precision turntable in the sheet metal workshop, and is mainly used to check the runout of large parts such as the combustion chamber casing.

In everyone's eyes, these two workers are skilled in their movements and cooperate with each other tacitly. It is estimated that they do such things frequently.

First use the dial indicator to find out the axis datum of the combustion chamber casing and the horizontal datum, and then replace it with a dial gauge for further calibration, so as to ensure that the runout of the two datum surfaces is within two or three thousandths.

After the benchmark is aligned, the next step is to check the runout of the turbine bearing seat.

This bearing seat requires runout to be no more than [-]/[-], coaxiality to be within one thread, and precision requirements are very high.

A worker slowly turns the turntable, and another worker checks the bearing housing with a dial gauge.

As soon as the head of the dial gauge contacts the inner wall of the bearing seat, you can see that the pointer of the dial gauge starts to jump slightly.

With the rotation of the turntable, the jumping range of the pointer becomes larger and larger, and even tends to exceed the measurement range of the dial indicator a little.

This, this, this.
How did that happen!

The welding test failed this time. Unexpectedly, the deformation caused by welding would be so large, and the beating of the bearing seat was seven or eight wires, far exceeding the five thousandths of the design requirement.

(End of this chapter)