Set sail1992

Chapter 244

Not to mention the warm reception of the prefectural committee and administrative office after the group arrived in Langya, it became an official document after writing it down. It was not until two days later that Vice President Zhao, Professor Xu and others came to China in the bus provided by the prefectural committee. Teng Machinery Manufacturing Co.

Although I heard from Zhang Qihang before coming here that the old factory area and the new factory area have entered the final stage of equipment debugging, but seeing this small factory in front of us, which is not much bigger than the factory run by the street, Professor Xu and Vice President Zhao and others were still very emotional: "Xiao Zhang, is your engine produced under such conditions?"

Zhang Qihang was very proud, he made a "please" gesture, and said to Vice President Zhao and the professors: "Dean, teachers, don't think our factory is a bit crude, but our production The equipment is quite good, and they are all good machine tools provided by domestic large-scale machine tool manufacturers such as Jiyiji and Jijiji, and the machining accuracy is among the best among domestic machine tools."

Vice President Zhao, Professor Xu, Professor Wang and others are naturally no strangers to Jiyiji, Jijiji, these old domestic machine tool manufacturers. These are the famous "Eighteen Machine Tool Sisters" in China. Now I heard Zhang Qihang say so , all the teachers are very surprised: In this humble factory, all kinds of processing equipment used come from such old big factories as Shungeng No. [-] Machine Tool Factory and Shungeng No. [-] Machine Tool Factory?

Vice President Zhao nodded with a smile, looking forward to it: "Oh? Then I have to take a good look...Xiao Zhang, can we go into your workshop to have a look?"

Zhang Qihang refused because he was stupid, he nodded hurriedly: "Of course it's okay, um... Teachers, let's go to the exhibition room first, and then go to the workshop later?"

No one refused, all the teachers were nodding, and everyone was a little curious, wanting to see what products Zhang Qihang and his company had.

When you come to the exhibition room, the first thing you see is a red-clothed exhibition table facing the door. There are two engines on the exhibition table. The structures of the two engines seem to be similar. , but the engine on the left is obviously more refined.

Since you are teaching engine-related courses, you professors are no strangers to internal combustion engines. Seeing the obviously more refined engine, Professor Xu said in surprise, "Huh...", walked forward two steps quickly, and looked carefully. After sizing it up, Professor Xu looked up at Zhang Qihang in surprise: "Qihang, is this engine your CJ60?"

It's not that Professor Xu recognized the difference between CJ50 and CJ60, but that there are explanatory plates in front of the two engines.

Not only Professor Xu, several other professors and Vice President Zhao also looked at this CJ60 engine curiously.

"is teacher."

Zhang Qihang nodded.

"You said before that you redesigned the shape of the piston and combustion chamber of the CJ60?" Professor Wang said with bright eyes, "Hurry up and let me have a look..."

Before Professor Wang finished speaking, Professor Li had already picked up a piston from another exhibition table next to this exhibition table, and looked at it carefully: "This is the new piston you designed? The one on it These two pits... set sail, what is the compression ratio of your CJ60?"

As soon as Professor Wang said these words, several other professors also pricked up their ears.

As we all know, the higher the compression ratio of the engine, the higher the energy can be squeezed out, so in today's world, the compression ratio of gasoline engines has become higher and higher. For example, the compression ratio of the Suzuki AX100 motorcycle is only 6.6:1, while the Jialing JH70 motorcycle The compression ratio of the car has reached 8.5:1, and for the Suzuki GS125 motorcycle, the compression ratio has reached 9.3:1.

Although the higher the compression ratio, the better, but for gasoline engines that use "ignition" as the combustion method, there is no way to increase the compression ratio blindly. The higher the compression ratio, the easier the engine knocks. How to deal with the compression ratio and knocking The relationship between earthquakes has become a headache for internal combustion engine engineers and technicians.

There is no groove on the top of the piston of the CJ50 engine, because the compression ratio of the CJ50 engine is not high, barely 6:1, so there is no need to make a fuss about the piston, but there are two fine lines on the top of the piston of the CJ60 in front of you. The small grooves are processed. Obviously, compared with the CJ50, the compression ratio of the CJ60 has been improved, and the increase is not a little, but a lot.

Under the watchful eyes of several teachers, Zhang Qihang did not hesitate, he nodded cheerfully: "The compression ratio of CJ60 is 7.2:1."

"7.2:1?" Professor Wang couldn't help frowning when he heard this: "A two-stroke engine has such a high compression ratio...how do you ensure that the engine won't detonate?"

"It's the combustion chamber."

"The combustion chamber?" Professor Wang's eyes lit up, "How do you say it?"

Zhang Qihang didn't hold back, and directly picked up an engine cylinder head of a CJ50 engine from the exhibition table on the side and showed it to the professors: "Teachers, you can see that the combustion chamber of the CJ50 engine is basically a hemispherical shape. Bar?"

Everyone nodded.

In fact, there is no need to look at it at all. As the motorcycle engine with the largest output in China in recent years, the CJ50 engine itself has been used as a textbook by many colleges and universities with internal combustion engine majors. Professor Wang, Professor Li and others are already familiar with this engine. Can't be more familiar, how can Zhang Qihang say it?

From a structural point of view, the top of the cylinder of a scavenging two-stroke engine, especially a single-cylinder two-stroke motorcycle engine, does not have the intake valve and exhaust valve of the four-stroke engine that we are familiar with, and there is only one spark plug, so the whole The shape of the top of the combustion chamber is particularly clear and obvious, it looks like an inverted bowl, that is, hemispherical.

"I redesigned the combustion chamber of the CJ50 to form a tumble flow in order to let the mixed gas swept up, and this is what it looks like," Zhang Qihang said while picking up the cylinder head of the CJ60 engine next to him, and at the same time showed it to Teachers, look: "The shape of the new combustion chamber has changed from the original hemispherical shape to a shape between the hemisphere and the roof ridge. According to our actual verification results, this shape of the combustion chamber can make the mixture gas Proudly more complete combustion, and in the case of increasing the compression ratio to 7.2:1, the use of 89 gasoline will not cause knocking."

It's one thing to hear it, but another thing to see it with your own eyes. Everyone is an expert in the field of internal combustion engines, so they naturally know that things are not as simple as Zhang Qihang said?The shape of the combustion chamber is finally determined after precise and rigorous calculations. Did you change it if you wanted to?Moreover, you, an undergraduate student, want to redesign the shape of the combustion chamber. Are you afraid that your brain will be burnt out?

But now it's really done?

This is not only unbelievable, it is outrageous!
(End of this chapter)