Nowadays, the development of automobiles has gradually changed from the demand of transportation to the choice of driving and handling comfort. When it comes to the sense of manipulation, it has to say the number of cylinders in the car. Of course, the larger the number of cylinders, the more horsepower will be. The bigger, the better the number of engine cylinders in the car, the better? What is its advantage?
As the car slowly turns to turbine, the development trend of small-row quantification, the general engine displacement, etc. are getting smaller and smaller. An engine of the same power, which used to be naturally inhaled by eight cylinders, will now develop at any time. It turned into a six-cylinder turbocharger. And the previous six-cylinder naturally aspirated engine is now a four-cylinder turbocharged engine.
If you want to compare the number of cylinders, and their advantages and disadvantages, you should first determine a fixed standard, such as the same displacement and the same technical level, then compare the two, can not take a 2.0 liter four cylinder The engine is compared with a 4.0-liter V8 engine, which is completely incomparable. So emphasize this point, and everyone should not come to this point.
What are the advantages of the more engine cylinders?
The first point is smoothness. Its power stroke superposition effect, for the current four-stroke engine on the car, a cycle is 720 degrees, what is 720 degrees equivalent? It is the crankshaft two turns, or its piston movement A process. If the engine is a four-cylinder, that is, four cylinders are alternately ignited, after one fire is completed, the other cylinder starts to ignite.
If the number of cylinders of the engine reaches 6 cylinders, 8 cylinders, 10 cylinders or even 12 cylinders, the power stroke stack will appear. The advantage of the power stroke stacking is that one cylinder has not been fired yet, and the other cylinder has already started. The ignition is relayed, and the power is uninterrupted. Therefore, the six-cylinder engine is a qualitative leap compared to the four-cylinder engine. The four cylinders are equally divided into four strokes, one cylinder and one stroke, and one cylinder is just after ignition. Six cylinders are equivalent to six cylinders divided equally into four strokes, so there must be some overlap, and the more the cylinders, the larger the overlapping area.
The second point has a large number of cylinders, and the increase in ride degree can improve fuel economy to a certain extent. Although the increase is limited, in the same situation, under the same displacement, the multi-cylinder engine will have less engine fuel economy than the cylinder number. The theory can be made lower. Because this engine runs more smoothly, you can achieve a lower and more stable idle speed. The lower the idle speed, what does that mean? When the vehicle is idling, the energy consumed will be smaller. Used to maintain the most basic energy of the engine, the fuel burned will be smaller.
Another point is the distribution of the efficiency characteristic of the engine's characteristic curve. In summary, the overall fuel economy is achieved if the engine is maintained at an independent output and the lower the speed and the larger the throttle opening. The higher the speed, the lower the number of friction between the piston and the cylinder wall within the unit time. On the other hand, the larger the throttle opening, the smoother the airflow passage of the intake air, so the engine is used here. The pumping air above will absorb the outside air. The smaller the energy loss of this part, the higher the fuel economy. And the multi-cylinder engine, because it is more smooth, can maintain a lower speed.
If the eight-cylinder engine is still running stably at 800 rpm, the four-cylinder engine may only be 1000 rpm under the same conditions. It has already started to shake. It has to go down one gear, make the throttle opening smaller, and make a more High speed.
Some car owners will question that the more the number of cylinders in the engine, the more parts there are, so is there more friction loss than the number of cylinders?
In fact, the number of cylinders is much less than the number of cylinders, because the four-cylinder and six-cylinder engines under the same displacement, although the six-cylinder engine is the friction between the six pistons and the cylinder, the four cylinders only have four pistons and cylinders. However, the size of each cylinder of the six cylinders will be smaller, so in the case of the same cylinder diameter and stroke ratio, the equivalent of a six-cylinder engine per unit time, the frictional area is equivalent to six of the four-cylinder engine. Four. Although the number of cylinders is large, the area of friction is small.
Another point of friction between the bearings, especially the main shaft, connects the bearing between the crankshaft and the connecting rod. The six-cylinder engine has two more bearings, is this friction even greater?
Not necessarily, the displacement of each cylinder of the six-cylinder engine is small, so the positive pressure on the bearing is also smaller, which is about four-fourths of that of the year-on-year, so although it is a six-cylinder, it is in some major components. The friction loss is almost the same.
There are many engines that have extended a new technology called closed-cylinder technology. Closed-cylinder technology can further save fuel. For example, if your engine is now eight cylinders, after shutting down four of the cylinders, it will be operated by four cylinders. In this case, it is possible to have a larger throttle opening with the same power output, which is equivalent to using four cylinders to absorb air less than the eight cylinders, and the pump power can be saved. Therefore, under the same conditions, the more the number of cylinders, the smoother it is, even if it is closed halfway, or after closing several of the cylinders, it can be smoother. This is also an advantage of more cylinders.
With the gradual improvement of technology and people's attention to environmental pollution, vehicles will gradually move from large displacement to small displacement, even new energy. Of course, if there are certain requirements for speed and handling, You can consider buying a large-displacement multi-cylinder engine and enjoying different driving pleasures. But compared to most owners, the general four-cylinder engine is completely sufficient.
