[YesAuto Factory Secret] Once any BMW factory overseas (compared to BMW headquartered in Germany) wanted to build an engine, the first thing was to go to Ranshut, Germany to ship the engine blanks back, but this matter The new engine plant of BMW Brilliance Tiexi, which was put into operation not long ago, was changed because it has become the most comprehensive plant in the BMW system. It is the first plant with casting technology after the Lanshut plant, which can independently produce new engines. A generation of B series engines. At present, the power system of the BMW 2 Series Wagon is derived from this, and the new domestic X1 and 3 Series are likely to be equipped with the engines here in the future.
In 2012, we visited the BMW Tiexi factory. Its highly automated, efficient vehicle manufacturing workshop and well-designed factory structure make us remember a lot. The scale of the factory is sufficient to reflect BMW's focus on the Chinese market. This year, BMW has built a world-class engine factory next door to the Tiexi plant. It is worth mentioning that the new plant is the only one in the BMW system that has three manufacturing processes and test workshops for engine casting, machining, and assembly in the same plant. The engine factory realized within. Before introducing the factory in detail, let's take a look at what new products this factory specializes in.
●The new generation of BMW three-cylinder and four-cylinder engines (B38, B48)
We have previously interpreted BMW’s new 2.0T four-cylinder engine (click here for details). We can see that the new generation of engines has not only made progress in performance and fuel efficiency, but more importantly, BMW has achieved modular production on this generation of products. Concept. Currently, this new plant produces a new generation of engines: including three-cylinder and four-cylinder gasoline engines, the code names of which are B38 and B48 respectively. Why is it so named?
The reason why BMW calls it a modular engine is that it is most intuitive to find that the cylinder size of the new-generation B series engine is the same, whether it is three-cylinder, four-cylinder, or six-cylinder, its bore × stroke is 82×94.6mm. This also allows a series of parts such as pistons, piston connecting rods, cylinder head gaskets and so on to have versatility. Of course, in addition to the cylinder block structure, fuel supply systems, cooling systems, etc. can also achieve a large proportion of common parts. In other words, just like building blocks, the hardware facilities of this new factory are also capable of producing BMW six-cylinder and eight-cylinder engines.
● Who uses the engines produced?
● Global distribution of BMW engine plants
From a global perspective, BMW has about 30 vehicle manufacturing plants, while there are only 4 traditional engine plants. One of them is a new engine plant that has just been completed and put into operation in Tiexi, Shenyang. The project was signed in August 2012. Construction started in August 2013 and it went into production smoothly after 28 months.
At present, in addition to the new engine plant in Tiexi, Shenyang, BMW also has the Munich and Ranshut plants in Germany, the Steyr plant in Austria, and the Hemshall plant in the United Kingdom. However, the only plant with a foundry is Two plants in Lancehut and BMW Brilliance in Shenyang. In addition, Shenyang Brilliance BMW's electric powertrain plant is also under construction, and it may become BMW's third new energy power plant in the world.
From the perspective of BMW's current global engine production layout, the Chinese market has become a very important base. It has many foundries that the BMW engine factory does not have. What is the level of this foundry in China? Let’s start with this foundry and talk about how the new generation of BMW B38 and B48 engines are made?
● Casting starts from a journey of a grain of sand
As early as thousands of years ago, this kind of metal thermal processing technology was already in existence in ancient China. From the bronzes and ironware unearthed in various ages, we can also see the Chinese people's skillful application of this technology, but this technology is placed in the engine. At the time of the above, the consideration is no longer the aesthetics of the appearance pattern, but the test of the mechanical properties of the cast product. In order to ensure that the residual stress, pores, and release agent of the finished product will not cause defects in the casting when the product is cooled and solidified, the casting process is proposed Extremely high requirements.
We know that the casting process is a method of casting liquid metal into a casting cavity mold suitable for the shape of the part, and after it has cooled and solidified, the part or blank is obtained. The molds for casting engines are generally made of foundry sand. The first step in casting cylinder blocks, cylinder heads and other parts is to start with a grain of sand.
Where did the used foundry sand go? 90% of the foundry sand in the new engine plant can be recycled and reused, and the remaining 10% of BMW is not wasted. They apply the 10% that cannot be recycled to construction materials, which is equivalent to achieving zero waste.
While the sand mold is being manufactured, the raw materials for casting aluminum alloy engine blocks are also being prepared at all times. The aluminum raw materials used in the production of B38 and B48 engines come from the domestic Lizhong Nonferrous Metals Company.
At this point, a piece of aluminum raw material has been turned into a qualified blank, and it has completed the task that other BMW plants could not complete except the Rangshut plant in Germany. Of course, this is only one-third of the engine production process, and then the rough parts are transported to the machining workshop.
● How to turn a blank into a part?
The casting workshop turned blocks of aluminum into rough parts of the engine block and cylinder head. However, after arriving in the machining workshop, these untrimmed guys must be properly repaired. Here, about 100 machining equipment can be used. Various processes such as turning, milling, planing, grinding, tongs, etc.
-How to omit the cylinder liner?
In the machining process, the engine will undergo a special process-arc spray cylinder inner wall, which is BMW’s LDS arc spray technology, which sprays metal wear-resistant materials on the cylinder wall, eliminating the traditional aluminum alloy engine Cylinder liner. This technology can make the cylinder wall have good wear resistance, reduce the power loss caused by friction to improve efficiency, and compared with the traditional cylinder liner, the thermal conductivity is better due to the thinner coating.
In the machining process, the cylinder wall is bored, but the required 82mm×94.6mm cylinder diameter×stroke size is not directly processed, because the cylinder inner wall needs to be cast before the arc spraying technology is applied to the cast cylinder block. Perform a “frosting” treatment, spray the inner wall with a high-pressure water gun, and use the high-speed impact of water to punch the inner wall out of the fine uneven surface. This is to make the cylinder wall rougher and make the arc sprayed coating better adhere to it. On the cylinder wall.
● The process of uniting ten thousand “pieces”
Compared with the foundry and machining workshops, there are obviously more workers in the engine assembly workshop, because some parts must be assembled manually. Like most engine factories, the entire workshop is divided into a cylinder head sub-assembly line and an assembly line Two production lines. Here, all the cylinder structure parts, the electrical parts provided by the supplier, and the wiring harness and other parts will complete a big gathering.
● The last step before going offline
After the engine is assembled, the workers will first conduct a tightness test on the engine to ensure that there are no problems such as water leakage, oil leakage, air leakage, etc., and then conduct a cold start test. It is worth mentioning that these test items are each offline The engine must be tested instead of random inspection.
In addition, the engine will be matched with a gearbox, fuel tank, cooling system, etc. to complete a 50-hour real comprehensive performance test, such as simulating various working conditions such as idling, acceleration, and constant speed during real driving to ensure each quality The parameters and performance parameters conform to the standard.
From the perspective of scale and equipment investment, BMW Brilliance’s new engine plant has undoubtedly become BMW’s world-class plant. Its only engine foundry outside of Germany has assumed the responsibility of producing the next generation of BMW engines in the future, and has since got rid of the imported engine blanks from overseas. Process. At present, the three major manufacturing workshops and inspection workshops of casting, machining and final assembly have been fully and normally put into operation. The advanced and comprehensive technological process of the new engine factory can effectively control production costs, further shorten the production cycle, and optimize production problems. Of course, we Ordinary consumers are more concerned about its excellent product quality inspection, because this is the key to whether we choose to buy a BMW. (Auto House Text/Picture Xia Zhimeng)