preface
Speaking of diesel engines, you may have seen this picture:
A group of elderly people blew gloves on the tractor, started a smoke-emitting engine, and then the balloon exploded, and their faces were covered with black diesel black smoke.
Some people may just take it as a paragraph.
However, as the boss of the technology UP master, I found through the data that the core technology of the diesel engine for tractors has long been mastered abroad.
The next questions are:
What are the advantages of diesel engines over gasoline engines?
What is the core technology of the diesel engine?
How does domestic manufacturing break the monopoly of foreign countries?
diesel engine
First, Whale wants to say that not all diesel engines are as huge, dumb, and black as tractors. They also need some tricks to reduce tailpipe emissions. Second, if the whales want to make the diesel engine more efficient, they must understand the difference between it and other machines. 1. What is the difference between a diesel engine and an engine? For example, from tanks to locomotives, from ships to heavy-duty trucks, they are all powered by diesel engines.
So, why do these things use diesel engines?
This brings us the benefits of a diesel engine with a high compression ratio, more torque, more power and better fuel economy.
Diesel engines have more in common with gasoline engines than four-stroke engines.
What is a four-stroke?
That is, each work cycle goes through four strokes: intake, compression, work, and exhaust.
Specifically, this is:
First, the vehicle starts with the intake stroke and moves downward through the open intake piston, sucking air into the cylinder while injecting fuel.
Then there is the compression stroke, where when the valve is closed, the piston moves upward to compress the oil and gas mixture. When the engine speed exceeds the specified value, the mixture will burn up to form a high temperature and high pressure air flow; at the same time, the pressure in the cylinder is increased due to the opening of the exhaust valve, which produces a huge expansion force and pushes the crankshaft to rotate. Then there's the work stroke, when the gas mixture ignites, forcing the piston back to the bottom of the cylinder.
Finally, there is the exhaust stroke, when the flammed oil-gas mixture is pushed out of the cylinder by the piston from the exhaust valve.
The difference between diesel engines
The difference is in how to ignite the air and the fuel.
Diesel engine is diesel, its viscosity is higher than gasoline, not easy to volatilize, and the ignition point is higher than gasoline. Because the diesel engine uses fuel injection and combustion methods when working, it can make the fuel mixed together completely; at the same time, it can reduce exhaust emissions into the atmosphere; and it can also save oil energy. The mixture in the cylinders of diesel engines is pressure-fired, and the higher the pressure, the higher the temperature, which means that the diesel engine does not need an ignition system.
While the gasoline engine is igniting, the fuel in the cylinder will be ignited by an electric spark plug.
Therefore, the compression ratio of diesel engines is higher than that of gasoline engines.
Diesel engines also don't have throttle valve bodies, which means that when we press the throttle, the diesel engine's injectors inject more diesel, generating more power.
Gasoline engines have a valve body, which means that when we press the throttle, you open the throttle, allowing more air to flow into the engine. But if the throttle is not opened, then the engine will not work because the combustion inside the engine is not sufficient. That's why the throttle is closed. In fact, the problem is very simple. Just press the throttle to the bottom. The more air, the more fuel the injector will deliver, the more fuel, the greater the power.
Diesel core technology
Although diesel engine oil has so many advantages, one of the biggest disadvantages is the problem of pollution, to put it bluntly, it will produce black smoke.
But this is not a problem with diesel engines, but more because the mainland once lagged behind diesel engine technology.
Most of today's diesel engines use electronically controlled diesel high-pressure common rail systems.
Maybe people are a little confused about the word.
How to understand this system?
If the engine is the "heart" of the car, then the system is the "heart" and "brain" of the diesel engine.
It is no exaggeration to say that it is the most difficult and high-precision system for diesel engine processing.
Let me talk to you specifically.
The high-pressure common rail system consists of an electronic control unit, a high-pressure oil pump, a common rail tube, an electronically controlled injector and various sensors.
Here's how it works:
The high-pressure oil pump is driven by a diesel engine, which injects fuel into the common rail and maintains high pressure, and then controls the injection through the high-speed solenoid valve of the injector, which can stably adjust and maintain the oil supply pressure, so as to achieve an accurate high-pressure injection effect.
In particular, the terms high pressure and common rail.
The high pressure is used because it puts the pressure on the injection system three times that of a conventional diesel engine. It has the following advantages: first, the injection volume is high; second, the spray penetration distance is long, which is conducive to reducing fuel consumption and reducing pollutant emissions; third, the fuel consumption rate is low. Compared to the 60-70 MPa of conventional diesel engines, engines below MPa have the advantages of high-pressure atomization and full combustion, which improves power and ultimately saves fuel.
So, what is the point of common track?
The common track is to supply fuel to each injector at the same time through a common fuel supply pipe, and the amount of fuel injected is accurately calculated by the car's electronic controller unit ECU, which you can understand as the car's brain.
Then the same quality and pressure of fuel is supplied to the fuel injector at the same time, so that the engine runs more smoothly, optimizes the comprehensive performance of the diesel engine, reduces vibration, fuel consumption and reduces emissions, and changes the image of the diesel engine "noisy and smoke-filled".
Domestic production breaks the monopoly of foreign countries
Germany, the United States, Japan and other countries occupy a huge share in the domestic market of high-pressure common rail systems for electric diesel engines, such as Bosch AG of Germany, Continental Company of Germany, Delphi Company of the United States, Denso of Japan and other companies.
They have long enjoyed a near-monopoly position, especially in Germany, where Bosch once held a market share of up to 85%.
So, is there such a business in China?
How far have we come?
The above is about the introduction of Wuxi Wuxi Oil Pump Nozzle Research Institute, after the introduction, we will come together to understand the Wuxi Wuding Pump Pipe Research Institute.
Founded in 1980, Wuwu is the only industry research institute directly under china's machinery industry.
In 2005, more than 200 units successfully developed a diesel electromechanically controlled high-pressure common rail fuel system and installed it on a truck, successfully completing a 1500 km trouble-free road test.
This makes China the fourth country in the world to master this technology after the United States, Germany and Japan.
How difficult is the development of this system?
The difficulties can be said to be reflected in all aspects, the two most difficult places, one is the control system, the other is the manufacturing technology. Control systems and manufacturing technologies are difficult to break through, but that doesn't stop the fact that there is a huge gap between them. Because control systems and manufacturing technology are inseparable, and the former is the basis of the latter; the latter determines whether the former can be successfully realized. In particular, the latter is the industry with the highest requirements for the machining accuracy of the electronically controlled common rail system in the global manufacturing industry, and no industry can surpass it.
For example, the electronically controlled common rail system has several couplings that can withstand pressures of more than 2000 kg, move flexibly, do not leak, and have a clearance of only 2 to 3 microns.
What is this concept?
This is equivalent to two cups being round with a diameter tolerance of less than 100 nanometers, which is undoubtedly a challenge to achieve complete consistency in machining.
In an interesting episode, Germany's industry leader Bosch invites oil-free companies to visit their factories. This company is a well-known car manufacturer in Germany, and its products enjoy a high reputation in the market for high quality and low price. But before the financial crisis, its performance was not good. Why is this happening? At the time, the Doctor's production line was highly automated, using robots and even accomplishing simple tasks in plain English.
But the head of the Oil-Free Research Institute was not intimidated by the automation equipment, but felt that we had to develop the technology, so he went back to the institute and began to overcome these problems.
On the one hand, we employ domestic and foreign experts as process consultants to put forward the shortcomings of the process, on the other hand, we train and develop the relevant personnel, through the introduction of equipment and ourselves, to produce products that meet our needs.
Step by step, the diesel electromechanically controlled high-pressure common rail system was developed.
feel
Some people may say, "I don't buy diesel cars, it doesn't seem to affect me!" ”
It's not like that.
We used to ride on diesel cars, which felt like the vibration noise on the tractor was too loud to replace a gasoline car, but now with a high-pressure common rail system, the vibration will drop, almost like a gasoline engine.
Diesel engines began to replace gasoline engines in large quantities, and the reliability, power and economy of diesel engines were very good, exceeding 50% when the proportion of diesel engines in Europe was the highest.
For example, armored vehicles, tanks, military vehicles, warships and other military equipment, as long as the use of diesel engines, high-pressure common rail system can be.
Without their own high-pressure common-orbit systems, they rush to buy foreign products, which, frankly, threatens national defense security.
It can be said that the development of the diesel engine industry has a great impact on China's industry, agriculture, transportation, national defense construction and people's lives.
Of course, in addition to the above-mentioned non-existent units, there are other domestic enterprises doing the same thing.
Although we have not really mastered the most advanced and core high-voltage common rail system technology, Minke Whale believes that through the efforts of many domestic enterprises, we have not only promoted the development of independent research and development, but also made great contributions to the technological progress of the engine industry.
Whale believes that in the near future, we will be able to pick up this top pearl of diesel engine class!