Whether it's a plow, a rice transplanter, a harvester. In fact, the structures are simple.
Outsiders think that building these is a fantasy. ,
But for people who study physics, especially those who understand mechanics, this is basically the simplest question. No need to think about it at all.
But the most important issue is still the cost.
Machinery used for farming only needs three aspects: low cost, durability and no need for maintenance, and powerful power.
It is not difficult to solve the two problems of durable leather and powerful power.
But it is not a simple matter to solve the problem of low cost.
Since it is going to be used for agricultural machinery, you have to at least make it affordable for farmers, right? What’s the point if it’s more expensive than renting a cow? The biggest significance is to reduce the price of beef...
Li Zhen lived in the motor home.
In fact, neither the School of Electromagnetics nor the School of Aviation can help in this matter.
Industry specializing in surgery. When it comes to manufacturing agricultural machinery, only the Motor Vehicle 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 engine. But the fuel consumption is too high."
A student said: "A four-stroke engine can reduce fuel consumption, but the cost of a four-stroke engine is definitely higher than the income from farming. This is not possible."
"If you want to solve this problem, it's actually not difficult."
Li Zhen raised his eyebrows: "Why isn't it difficult?"
The student who said this said: "First of all, we must know why the four-stroke engine is so expensive. Once you know this problem, you can solve the problem."
Ma Jianbin drew a few strokes on the paper and said: "The main valuable part of this four-stroke engine is actually the cylinder craftsmanship. The cylinder is a precision component, and it is not possible to use a knife on the cylinder. Some other exhaust facilities, compressed air Some changes could be made to the facilities. But this electronic ignition system, to be honest, is expensive."
Li Zhen looked at the drawings. He didn't understand the cost of these things before.
Asked: “How much does a conventional four-stroke engine cost?”
"About one thousand gold coupons."
Li Zhen was silent for a while: "What about the cost of the cylinder?"
"Automobiles usually use four cylinders, and one cylinder costs more than 200. By the way, the number of cylinders can be reduced, and we can make a two-cylinder engine."
“How much does an electronic ignition system cost?”
Ma Jianbin said sternly: "The cost and maintenance of this electronic ignition are quite expensive. In terms of the current industrial technology in New Kyushu, the price of the electronic ignition system cannot be lowered. The battery requires a lot of money, as well as spark plugs, which are more expensive than cylinders. The technology needs to be more sophisticated. An electronic ignition system costs no less than 600. This is why steam cars are cheap and cars are expensive. Steam cars do not have these complicated processes. Although the power is not good, others love to use them. .”
Li Zhen waved his hand: "Delete the idea ignition system."
"Ah? Deleted the ignition system? What should I do then? Wouldn't it become useless?"
Li Zhen said in a deep voice: "Use a manual compression ignition system. Change the fuel to diesel. This solves the problem. The cost is reduced by half."
"diesel fuel?"
Everyone frowned.
I am actually not unfamiliar with this fuel, because of the oil refining technology, there are so many things that can be refined.
Everyone has tried diesel engines before. But because gasoline is more suitable for electronic ignition systems, everyone put down diesel.
Everyone is well aware of the difference between gasoline and diesel. To be honest, diesel fuel is more economical than gasoline.
The cost of diesel and gasoline is actually about the same. But the main reason is that diesel can exert greater power and last longer, so in terms of energy saving, diesel is cheaper than gasoline.
The only drawback is that when the diesel burns, it emits black smoke. This is also the reason why no one mainly studies diesel engines.
However, every thing that exists has its value and reason. After all, a diesel engine is still needed.
Ma Jianbin frowned and said: "Compression ignition... To be honest, the Motor Vehicle Institute gave up on this project before. Now it needs to be re-researched, which will take a lot of time. After all, the first way is convenient and quick, so the first one The only way out is the electric spark system. Now if we go back and study compression ignition from scratch, we don’t know how much effort it will take and how many experiments it will take.”
Li Zhen was silent for a while and said: "Compression ignition is not difficult. You only need to master a few principles. With your experience in building so many engines, it will be easy to understand."
"Master Li, please remind me."
Li Zhen pondered for a while and began to recall some of the principles Zhang Zhi had told him before.
I used to think that the diesel engine might not be of use, but the Motor Vehicle Institute was always busy, so I never said anything.
Now that this sudden move was going to come in handy, he really had to think about it.
After pondering for a moment, Li Zhen said:
"First of all, the principle of this compression ignition engine must act on diesel. Because diesel has a low ignition point, it can be burned through compression."
Everyone nodded.
They know that diesel has a low auto-ignition point. But again, the fluidity of diesel is too poor. Not as smooth as gasoline.
"This is actually not difficult. Just let the mixture of diesel and air be compressed by a powerful force to increase the temperature, and it can push the cylinder to work. The principle behind is similar to that of a steam engine. The cylinder is in Driven by the crank connecting rod, when it moves back, it will naturally complete another compression. At the beginning, it only needs to be manually compressed, and after the operation, it can be compressed automatically.: "
"So in terms of principle, it's not difficult at all. Let me draw a picture.":
As he spoke, Li Zhen walked to the blackboard and used chalk to draw a diesel tractor that was relatively common in that era. The main drawing was the rocker-type ignition method.
Seeing this rocker pose, Ma Jianbin and others suddenly realized something.
Not difficult.
It's really not difficult.
Its principle is really too simple compared to the electric ignition gasoline engine.
All of this occurs according to the characteristics of diesel.
The evaporation and fluidity of diesel are worse than that of gasoline, so diesel engines cannot form combustible mixed gases outside the cylinder like gasoline engines, so that they can be burned with a spark plug. Spark plugs don't matter.
However, the combustible mixture of a diesel engine can only be formed in the cylinder. When approaching the end of the compression stroke, diesel is injected into the cylinder through the fuel injector. At this time, the cylinder is mainly filled with hot air. The small oil droplets of diesel are heated, evaporated, diffused in the hot cylinder air, and mixed with air to form a combustible mixture, which eventually ignites spontaneously.
The key point is actually the joystick.
By manually shaking the rocker, the internal machinery is driven to produce mechanical supercharging. This will perfectly solve this problem.
(End of chapter)