Whether it's a plougher, a rice transplanter, a harvester. In fact, the structure is simple.

Outsiders think it's impossible to build these. 、

But for people who study physics, especially those who understand mechanics, this is fundamentally the easiest question. Don't even think about it.

However, the most important issue is still the cost.

Machinery used in agriculture only needs three aspects: low cost, durable leather without maintenance, and strong power.

It is not difficult to solve the two problems of durable leather and strong power.

But it's not easy to solve the problem of low cost.

If you want to use it for agricultural machinery, you must at least make it affordable for farmers, right? What's the point if it's more expensive than the rent of a cow? The biggest significance is that the price of beef has been reduced......

Li Zhen lived in a mobile courtyard.

In fact, both the Institute of Electromagnetism and the Institute of Aviation have no way to help in this matter.

There is a specialization in the art industry. In the manufacture of agricultural machinery, only the mobile institute can help.

Ma Jianbin said: "In terms of cost, the cost of a two-stroke engine is lower than that of a four-stroke. But the fuel consumption is too great. ”

One student said: "Fuel consumption can be reduced in a four-stroke engine, but the cost of a four-stroke engine is definitely higher than the income from arable land." It's not okay. ”

"Wanted to solve this problem. Actually, it's not that hard. ”

Li Zhen raised his eyebrows: "Why isn't it difficult?" ”

The student who said this said: "First of all, you have to know where the four-stroke engine is expensive. Knowing the problem, you can solve the problem. ”

Ma Jianbin drew a few strokes on the paper and said: "The main parts of this four-stroke engine are actually valuable in the cylinder process. The cylinder is a precision part, and it is not possible to move the knife on the cylinder. Some other exhaust facilities, compressed air facilities can be changed. But this electronic ignition system, to be honest, is expensive. ”

Li Zhen looked at the drawings, he didn't know the cost of these things before.

Ask, "How much does a regular four-stroke engine cost?" ”

"It's about a thousand hardware coupons."

Li Zhen was silent for a while: "What about the cost of the cylinder?" ”

"Cars are generally four-cylinder, and the cost of one cylinder is more than 200. By the way, the number of cylinders can be compressed, and we can make a two-cylinder engine. ”

"How much does an electronic lighter cost?"

Ma Jianbin said: "The cost and maintenance of this electronic lighter are quite expensive. With the current industrial technology of Shin-Kyushu, the price of electronic lighter systems cannot be low. The battery costs a lot of money, and there are spark plugs, which are more sophisticated systems than the cylinder process. An electronic lighter system costs no less than six hundred. That's why steam cars are cheap and cars are expensive. The steam car does not have these complicated processes, although the power is not good, but others love to use it. ”

Li Zhen waved his hand: "Deleted the idea of ignition system." ”

"Huh? Removed the ignition system? So what to do? Wouldn't that be waste? ”

Li Zhen said in a deep voice: "Use a manual compression ignition system." Fuel is replaced with diesel. That solves the problem. The cost is half as low. ”

"Diesel?"

Everyone frowned.

In fact, I am no stranger to this fuel, because of petroleum refining technology, there are more things refined.

You've tried diesel engines before. But because gasoline is more in line with the electronic ignition system, everyone put down the diesel.

Everyone is still well aware of the difference between gasoline and diesel. Truth be told, diesel is cheaper than gasoline.

The cost of diesel gasoline is actually about the same. But the main thing is that diesel can exert more power and last longer, so in terms of energy saving, diesel is cheaper than gasoline.

The only drawback is that as soon as the diesel burns, black smoke rises everywhere. This is also the reason why everyone does not mainly study diesel engines.

However, everything that exists has its value and reason. Finally, the diesel engine is still used.

Ma Jianbin frowned and said, "Compression ignition...... To tell the truth, the Mobile Institute had abandoned the project before. Now to re-study it, it will take a lot of time. After all, the first road is convenient and fast, so the first road is the EDM system. Now when I go back and study compression ignition from scratch, I don't know how much effort it will take and how many experiments will be done. ”

Li Zhen was silent for a while and said, "The compression ignition engine is not difficult. You only need to grasp a few principles, and with your experience in building so many engines, you can make a point. ”

"Please also remind Master Li."

Li Zhen pondered for a while and began to recall some of the principles that Zhang Zhi had taught him before.

I used to think that the diesel engine probably didn't come in handy, and the mobile yard was busy all the time, so I never said it.

Now that it was going to come in handy, he really had to think about it.

After a moment of silence, Li Zhen said:

"First of all, the principle of this compression ignition engine is that it must act on diesel. Because diesel has a low ignition point, it can be burned by compression. ”

Everyone nodded.

They know that diesel has a low spontaneous ignition point. But again, the fluidity of diesel is too poor. Not as smooth as gas.

"It's actually not that hard. It only needs to let the mixture of diesel and air be compressed by a powerful force once, so that the temperature rises, and it can push the cylinder to work. The principle behind is similar to that of a steam engine, the cylinder is driven by the crank connecting rod, and when it runs back, it naturally completes another compression. At first, you only need to do the compression manually, and after the operation, you can use the automatic compression. ：”

"So in terms of principle, it's actually not difficult at all. I'll draw a picture. ”：

As he spoke, Li Zhen walked to the blackboard and drew a chalk chapter to a diesel tractor that was more common in that era, mainly drawing the rocker-type way of ignition.

Seeing this rocker pose, Ma Jianbin and others suddenly realized.

It's not hard.

It's really not that hard.

Its principle is really too simple compared to the gasoline engine of electric lighter.

All of this is based on the characteristics of diesel.

Diesel has worse evaporation and fluidity than gasoline, so diesel engines cannot form combustible gases outside the cylinder like gasoline engines, so they can burn with a spark plug. The spark plug is a bit not.

However, the combustible mixture of the diesel engine can only be formed in the cylinder, and the diesel fuel is injected into the cylinder through the fuel injector near the end of the compression stroke. At this time, the cylinder is mainly hot air, and the small oil droplets of diesel fuel are heated, evaporated, diffused, and mixed with the air to form a combustible mixed gas, and finally spontaneously ignited and burned.

And the key point is actually that rocker.

The joystick is shaken by manpower, and the internal machinery is driven to generate mechanical pressurization. This is the perfect solution to this problem.