No crankshaft, no connecting rod? Toyota detonated the new revolution in the engine!
Did you know that your variable valve timing direct injection turbocharged engine is out of date! And there are no crankshafts and connecting rods that can be operated directly by the reciprocating motion of the piston!
FreePiston EngineLinearGenerator (hereinafter referred to as FPEG), a free-piston engine linear generator that Toyota is developing, is expected to make this all happen. Think of it as a free piston engine + a linear generator. Is it the engine or the generator?
Simply put, the FPEG engine is like a gasoline generator. At present, Toyota's trial version uses a single-cylinder design, which has a larger combustion chamber and piston than a conventional fuel engine. The piston moves back and forth under the driving force generated by fuel detonation, but this time its task is not to output to the wheel. Power, but power generation.
Toyota developed FPEG to design a small device for the extended-range electric vehicle. Compared to the engines and generators used in the current extended-range electric vehicles, FPEG will greatly reduce the size and weight of the engine.
FPEG engine, cancel the crank mechanism to make piston movement more free
In fact, FPEG is not a new technology, because as early as 1959, the world's first FPEG has obtained patent certification, and FPEG is based on the basis of FPE (FreePistonEngine).
So, what is the FPEG engine? As the name implies, we can know that the piston of this engine has a higher degree of freedom, but how does it allow the piston to move freely? The reason is to cancel the crankshaft and the connecting rod structure, and Instead of air springs (AirSpring), the piston movement is controlled by the gas in the combustion chamber and the air spring (AirSpring) control, the designer can determine the pressure and volume of the air, so that the overall design tends to be liberalized. To put it simply, when the piston runs to the bottom dead center, it will encounter the blockage of the air spring and rebound, and the piston will move to the top dead center. When it reaches the top dead center, the gas thrust generated by the fuel combustion explosion will be generated. Run to the bottom of the dead, and start again.
The biggest difference between an extended-range electric vehicle and a hybrid electric vehicle is that the gasoline engine only charges the battery and does not directly participate in driving the vehicle. The world's first extended-range electric vehicle, the Chevrolet Volt (VOLT), was only retrofitted to the traditional 1.4-liter gasoline engine.
Toyota gives FPEG super high thermal efficiency
Toyota's FPEG technology is a power generation unit based on the operation of FPE. Under the traditional oil-electric system, the generator is separated from the engine body, and the generator is connected to the engine crankshaft and uses its gyrokinetic energy to generate electricity. However, Toyota's FPEG is different. Since FPEG has no crankshaft, the piston body becomes a generator. And because there is no mechanism device for the crankshaft, the volume of the engine body is thus reduced, and the construction is relatively simple.
The Toyota FPEG power generation method is operated by a permanent magnet (PermanentMagnet) mounted on the piston and a coil generator (Coil) outside the magnet. On the opposite side of the combustion chamber, the original factory fills a confined space with air to make it an air spring. This device can replace the crankshaft design, allowing the piston to rebound and move backwards when it reaches the bottom dead center. The magnets are repeatedly operated in the coil group and interacted with each other, and electricity is generated.
The working principle of FPEG is the same as that of the two-stroke engine. When the piston descends, the work is completed, and the exhaust gas is used to extrude the exhaust gas. When the piston is ascending, the fresh air is sucked in the lower part of the piston, and the compression stroke is completed, and the top dead center is reached. Complete the injection and ignition work.
Toyota said that the FPEG engine can achieve 42% thermal efficiency under continuous use. In today's world, only the best, most complicated, and most expensive gasoline engines can achieve this percentage effect, and must be under certain conditions. What's more remarkable is that the FPEG engine is only 60 cm in length and 20 cm in diameter. Such a size FPEG engine can produce 13 horsepower output, so it does not have the conditions to assemble a large large vehicle, but it is enough to drive a miniature electric car. And the FPEG engine can also work with other systems such as kinetic energy recovery systems to achieve better results.
Not only gasoline, almost any fuel can drive FPEG
Toyota said that the actual production schedule of FPEG has not yet been determined, but it also indicates that since FPEG has no crankshaft and is controlled by air springs, the compression ratio of the internal combustion engine can be freely controlled by the volume of the air spring, which means FPEG. In addition to using gasoline as a driving fuel, hydrogen fuel is also a viable option. After FPEG officially enters the automotive market in the future, the development of Hybrid models will have more possibilities, and this is undoubtedly a big profit for consumers.
