In the past, the auto giants were proud to be able to produce 12-cylinder self-priming engines. Once upon a time, V8 and V6 were the standard for luxury cars. However, in the past two years, with the global flag of 'energy saving and emission reduction', As the national 4-stage fuel limit indicator is approaching and the “double-point” policy is about to be fully implemented, the companies have responded to the call, just like playing 'chicken blood' and launched a series of intense, 'no lower limit' small Displacement warfare, the engine 'smallization' represented by the three-cylinder, 'reasonable streamlining', has become a new trend in the development of internal combustion engines after turbocharging.
The three-cylinder engine has returned to the rivers and lakes, and a new round of competition has started.
When it comes to the 'three-cylinder machine', many people are not very impressed by it. The horsepower is small, the vibration is large, and the low-speed noise is huge. It is the inherent impression of the Chinese people on the three-cylinder engine. As a result, many people now mention the three-cylinder engine. Naturally considered to be 'a backward product'.
However, in the past 30 years, Hedong, thirty years of Hexi, no one thought that the three-cylinder engine that we used to be rejected by us has gradually become the 'toon' of GM, Ford, BMW and other major manufacturers.
Since 2010, Ford, PSA and other car companies have already introduced 1.0T, 1.2T and other small displacement three-cylinder turbocharged engines in the European market to replace the original 1.2L-1.6L naturally aspirated engine. Engine models, such as the Focus, Carnival, Peugeot 308 and other models have gained high recognition in the European market.
Similarly, the 'three-cylinder machine' war has spread to the Chinese market. For luxury brands, BMW is the most aggressive. The i8 is the first to carry a 1.5T three-cylinder turbocharged engine to the current 1 Series sedan, a 2 Series wagon, BMW. The X1, and even the current BMW 3 Series are equipped with 1.5T three-cylinder engines. In terms of joint venture brands, GM's Buick brand has been fully equipped with a three-cylinder engine in the Chinese market, which was launched in October last year, Xinyinglang, Yuelang and GL6. It can be said that it is the most determined joint venture brand for the three-cylinder technology layout in China.
Volkswagen and Toyota are slower than competitors, but the development of the three-cylinder machine has not slackened. According to foreign media reports, Volkswagen will launch a new 1.0L and 1.0T two-cylinder engine products in the overseas version of the new POLO, while Toyota announced that the Corolla with a 1.5T three-cylinder engine will be available soon.
It can be seen that Volkswagen, General Motors, Ford, Honda, PSA and other manufacturers have launched three-cylinder models, including luxury brands like BMW and Volvo.... Even Ferrari has developed a The three-cylinder supercharged engine has a power of 160 hp!
Then, why did the car companies start to develop three-cylinders?
First, under the big environment, engine miniaturization has become a trend. Nowadays, the whole world is calling for energy conservation and emission reduction. The EU, the United States, and China have also introduced increasingly strict emission regulations. In China, for example, the country's new country IV The standard will be implemented in 2020, and the standard will be set to 5L/100km. In order to achieve this goal, it is undoubtedly an effective way to promote hybrid power and reduce the number of cylinders. Whether developing small turbocharged engines or hybrids In these two technical directions, the three-cylinder engine is the best choice. After all, the three-cylinder engine is designed to allow both the horse to run and the horse to eat less.
Second, the technology is becoming more and more mature. In fact, some foreign manufacturers have already had the experience of successful development of the three-cylinder machine, which also makes it a qualitative improvement in the field of engine technology, more mature and leading, in order to catch up with the opponent, Many manufacturers have also begun to develop the field of three-cylinder technology. Under the support of many new technologies, it is no longer the past 'ugly duckling'. The problems of jitter and noise in the past three-cylinder engines have been very Great improvement.
Third, the three-cylinder engine has a congenital advantage. Some people say that since the small displacement is fuel-efficient, why do you have to stick to the three-cylinder? Isn't it better to do a four-cylinder small-displacement engine, and the problem of jitter and noise can be obtained? Effective solution. In fact, the same size of the small displacement four-cylinder engine is not as good as the three-cylinder engine in terms of fuel economy.
Nissan has experimented with a 1.2-liter four-cylinder engine that has been expanded from the original single-cylinder 300ml to 400ml, and the four-cylinder has become a three-cylinder. The thermal efficiency of the engine has increased by 2%. The cylinder is expanded to 500ml, and the thermal efficiency is still There is a 0.5% increase, and the thermal efficiency brought about by the expansion of the cylinder has dropped significantly. It is concluded that the closer the engine cylinder volume is to 0.5L, the higher the thermal efficiency.
Tests have shown that the optimal displacement of a single cylinder is between 0.33L and 0.5L, so for a 1.0L to 1.5L engine, a three-cylinder engine is actually the best choice. This is why all three-cylinder engines on the market. The reason why its displacement is below 1.5L. In some respects, although the three-cylinder machine now erodes part of the market of four-cylinder machines, it is limited by the concept of consumption, the limitation of congenital structure, etc. The machine is currently unable to replace the four-cylinder engine.
In summary, with the increasingly strict emission standards, the constant change of manufacturers' technology and the inherent advantages of the three-cylinder engine itself make the three-cylinder engine return to people's field of vision once again.
Has the three-cylinder machine removed the 'lagged' label?
Some people think that the three-cylinder is one less than the four-cylinder, so the cost will be greatly reduced. In fact, this is not the case. No matter the R&D expenses required to develop a three-cylinder engine, it is guaranteed to be less than a four-cylinder engine. Under the premise of one cylinder, the same power output, and better fuel economy, so more new technology and higher cost material blessing and assistance are needed.
For example, the GM and PSA three-cylinder engines are all aluminum cylinders, and the versatile Ecotec 1.0T three-cylinder engine also features an electronic actuator turbocharger, oil cooler, piston cooling nozzle, and central variable When the cross-flow separation and cooling integrated exhaust manifold and a series of new technologies are added to improve performance, the cost of the Buick three-cylinder engine is 40% higher than that of the four-cylinder engine. Yes, three-cylinder engine It is 'minus and not simple'. It is not that the cylinder is reduced by one, and the cost is down.
Then, with the support of many new technologies, the defects of the three-cylinder engine's past jitter and noise are really improved.
First of all, the problem of jitter. The reason why the three-cylinder engine is shaken is because there is one less cylinder, which makes the three-cylinder engine often unstable when outputting power. When the piston of the four-stroke three-cylinder engine is working, its crankshaft The angle is 120 degrees, there are always two cylinders running at the same time, and the other cylinder is operated separately, so that the crankshaft is stronger and the force is not balanced enough, so that the force generated by the two cannot be completely offset, so it will inevitably appear. Jitter phenomenon.
In the face of such defects, the current mainstream method of manufacturers is to cancel the traditional balance shaft, and use a small-sized crankshaft to offset and reduce the torsional vibration of the engine-side active flywheel, thus achieving better vibration control. This is the case with the Ecoboost 1.0T three-cylinder engine, and Ford has worked hard on the crankshaft counterweight to offset the center of gravity of the weights of the 1, 3 cylinder cranks by 30° to counteract the torque.
The versatile Ecotec three-cylinder engine is even more powerful. On a conventional basis, a pendulum-type dual-mass flywheel different from the traditional dual-mass flywheel is used, which uses a pendulum-type centrifugal pendulum reciprocating action to counteract and reduce the offset from the engine side. The torsional vibration of the active flywheel. Therefore, in theory, the universal Ecotec three-cylinder engine can minimize jitter.
Of course, there is noise in the presence of jitter. In addition to the need to do enough homework on the engine, how to prevent vibration from entering the car and reducing noise is also considered more for a three-cylinder engine than a four-cylinder engine.
Taking the Buick GL6 as an example, in addition to the use of ultra-quiet belts and the addition of soundproofing materials such as soundproof covers, engineers have also spent a lot of time on the connection between the engine and the body. Instead of using the most common rubber block suspension, A higher cost hydraulic suspension is used to achieve a better soft connection between the engine and the body. The three-cylinder engine is equipped with a three-point suspension system with hydraulic support, so that the vibration of the engine can be blocked. Suspend the system to further reduce noise.
Finally, on how to improve the dynamic performance, it is also a user's concern. It is well known that the three-cylinder machine is congenitally less than one cylinder, resulting in insufficient intake air and low torque. Therefore, the start-up performance of the three-cylinder engine is obviously not as good as the traditional one. Four-cylinder engine, so the three-cylinder machine will be more difficult when climbing. However, with the popularization and advancement of technologies such as direct injection and turbocharging in the cylinder, the three-cylinder engine has insufficient power at low speed. The problem, its power output performance even exceeds some traditional 1.6L, 2.0L four-cylinder engine.
Take the 1.3T three-cylinder machine in the GM Ecotec powertrain as an example. Its mission is to replace the previous generation 1.4TEcotec four-cylinder turbocharged engine. From the data point of view, its maximum output power is 163 hp. Compared with the 1.4TEcotec engine, it has a 23% increase and a maximum torque of 230 Nm, which is 15% higher than the 1.4TEcotec engine. It can be said that the traditional four-cylinder naturally aspirated engine is no exception in terms of power and torque. Is in the wind.
In fact, the GM three-cylinder engine has a big advantage over its competitors. No matter the universal 1.0TEcotec or the 1.3TEcotec three-cylinder machine, the intelligent dual-injection technology is used, through the synergy of the two injectors on the top of each cylinder. Injection, to ensure the even distribution of atomized fuel in the engine cylinder, to reduce the occurrence of the fuel wet wall. In addition, the two injectors through the valve injection to cool the mixture in the cylinder, also solved the previous small displacement The three-cylinder turbocharged engine has always faced a short-term risk of knocking.
At the same time, the higher performance ECU also plays a small role. GM's new Ecotec series of small displacement three-cylinder engines include the center-mounted DVVT dual variable valve timing system, intelligent thermal management system, intelligent start-stop system. , intelligent ignition coil, intelligent variable displacement oil pump, electronic throttle, etc. In the maximum optimization of engine performance, it also has outstanding contributions to fuel economy and clean emissions.
Therefore, on the whole, the three-cylinder machine does not lose the four-cylinder machine. In particular, there is no obvious abnormality in the actual performance of the power performance and the same displacement four-cylinder, and the fuel consumption is further reduced. Therefore, the consumer is for the three-cylinder engine. The degree of recognition is also gradually increasing. The data shows that Buick Hideo, Yuelang, GL6 and other models equipped with a new generation of three-cylinder machines have been listed since the fourth quarter of 2017. As of June this year, the market has sold more than 280,000 units. The trend is that the three-cylinder engine is not a flood of beasts, but an inevitable trend in the current environment. In the future, it is expected to become the mainstream of the industry like a turbocharged engine instead of a naturally aspirated engine.
Of course, the three-cylinder machine is currently facing challenges, especially the concept of consumption. Many consumers choose to remove the three-cylinder machine when they choose a car. How to let the market and consumers accept the technology upgrade and performance improvement 3. The three - cylinder machine is a subject that every car company faces.
