If you open the hood of a modern car, you will no longer see the engine in its classic form: a cylinder block, a head, a carburetor, pipelines, oil leaks everywhere … Outside, there is only a decorative plastic cover and is clean. Let's try to lift this veil and see what will be hidden inside the mechanical heart in the coming century. The developers of some well-known company, for example, FIAT, will help us in this. Its specialists, who have just celebrated the centenary of the company, have already begun the countdown of the next century by creating new nice words.
“Multijet” - by this neologism, FIAT designated multiphase direct injection on a diesel engine with a “Common Rail” system. The predecessor, also, incidentally, developed by FIAT, was called Unidget, and it provided two phases of fuel injection into the cylinders. The success of the system exceeded expectations - it took root on the engines of not only Italian brands, but began to multiply in other countries.
Now the FIAT has taken the next step: the injection is not divided into two, but into many stages, following one after the other during the entire combustion time of the mixture. Result? The engine efficiency is increased, its noise is reduced, and the toxicity of the exhaust is reduced by as much as 30-40%! Multijet is controlled by a new controller, which, depending on the speed, load and temperature of the engine, selects the optimal number of micro-injections and the amount of fuel supplied to the cylinder. So, say, when working at full load, soot emissions are reduced, and torque is increased. In the warm-up mode and at idle, the main focus is to reduce the noise level of the diesel engine.
"Ecodriver" is a combination of an internal combustion engine and an electric motor, tandemly connected into a single unit. A beautifully sounding word stands for Energy Conversion & Driveline Efficient Reengineering (energy conversion and economical energy recovery on the go). So, the electric motor is mounted on the ICE shaft in front of the gearbox. During the acceleration of the car, its "electric force" increases the torque, after which the electric motor goes into generator mode and recharges powerful batteries. A particularly large charging current can be obtained during braking, at the same time saving the pads from wear.
We were not mistaken when we said “batteries”: there are two of them on a car with an “Ecodriver”. One, a traditional twelve-volt, feeds low-power consumers, the second produces 36 and 150 V for the electric motor itself and for such voracious units as air conditioning or servo control. The motor generator here is so powerful that it can provide movement of the car independently. Such an electromobile mode is set by a smart host computer, primarily when driving in city traffic jams, when the harmful exhaust of an internal combustion engine reaches a maximum. It is worth starting the acceleration, as the electric motor starts the main engine to work, playing the role of a starter. By the way, a similar Continental-Tevez system called ISAD is already running on the Citroen, only there the generator is combined with a flywheel (ЗР, 1998, No. 9). Moreover, the starter-generator directly sitting on the crankshaft is now offered by almost all suppliers of components that are a little known in the automotive world, and therefore it can safely be said that the age of a starter buzzing in the morning is ending.
Ergodget (Engine & Robotized Gearbox Optimization, that is, engine and robotic gearbox optimization) is “just” a computer program linking the engine and automatic gearbox controllers. Its task is to optimally coordinate the operation of the engine and transmission, which saves up to 20% (!) Of fuel. The dynamic parameters of the FIAT-Punto equipped with an Ergodget turned out to be close to the Punto Sporting version, while the fuel consumption was only 4.5 l / 100 km compared to 7.3 l for Sporting.
VVA (Variable Valve Actuation) - Variable valve control. It is about individual control of the process of opening and closing the intake valves, which makes it possible to optimally meter the air entering each cylinder. There is still an old acquaintance - the cam shaft, but it no longer contacts directly with the valve stems. An oil-filled chamber is located between the cam and valve (Fig. 1). If it is full, the system works like a normal camshaft, but if there is less oil in the chamber, the valve opening is delayed. The electromagnetic mechanism controls the spool and can at any time suspend the opening of the intake valve or even close it with a return spring. The adjustment limits allow you to completely disable any of the inlet valves. As a result - 10-15% of fuel economy, and the engine power and torque increase by the same amount.
And now let's digress a bit from the FIAT developments, because Siemens designers went further and decided to completely abandon the camshafts in the engine of the future and control valves using powerful solenoids (Fig. 2). Here it is already possible to set any conceivable program, and for each valve individually - full scope for engine operators. But the current consumption by a system of at least 16 solenoids is so great that a powerful generator with a voltage of 42 V cannot be dispensed with, and here the Ecodriver will be very helpful.
NZEV (Near Zero Emission Vehicle - a car with close to zero exhaust). This new product is under development and, by 2003, may receive a more sonorous name. It is about eliminating the main drawback of a diesel engine - the emission of nitrogen oxides and soot particles. The reason for the formation of these harmful substances is that the combustion chamber has areas with different ratios of fuel and air and different temperatures. Near nozzles, for example, diesel fuel is relatively large, and the temperature is low. Hence the unburned soot particles. In the other part of the cylinder, on the contrary, the temperature is high and there is little fuel. Here, as a result of the "combustion" of excess air, nitrogen oxides are formed. As it turned out, between these areas there is a zone where the composition of the mixture is close to stoichiometric, that is, the amount of air exactly corresponds to the required for complete (and clean!) Combustion of diesel fuel. In NZEV technology, the first fiddle is played by the MultiJet with its time-distributed injection and VVA with optimized air supply. Expected result: particle emission at the level of 0.01 g / km and NOx below 0.1 g / km, which is 60% less than the EU standards established for 2005.
As you can see, FIAT alone offers five know-how in engine building for the coming century. But there is also a Volkswagen with its indefatigable desire for extremes (from "3-liter" cars to 18-cylinder monsters) and offering ultra-high pressure pump nozzles for diesel engines and a layered charge with a mixture of cylinders of gasoline engines. There is a BMW that is steadily improving the “Common Rail” system, there is a Peugeot that has developed a unique exhaust gas purification system … Yes, and the Japanese are not asleep with the Americans - they are building hybrid cars.
Someone may ask: well, all of this practically already exists, and then what? Is there anything else that can be changed, improved, improved in our good old internal combustion engine? It turns out that there are more than enough ideas and they relate to almost all motor components from top to bottom.
The basis of the basics - cylinders with pistons - will hardly change, unless the piston bottom is pitted with hollows of a bizarre shape. This is the designers will try to provide a given movement of the charge of the combustible mixture to optimize the combustion process. As you know, the fuller it is, the more economical the engine, the less harmful substances fly into the exhaust manifold.
In the search for the necessary forms, there remains a field of activity for “free artists”. For example, Kurt Koenig, a 61-year-old teacher from Issing (Germany), managed to get two medals at once for the invented pistons - gold and bronze - at the 1999 Geneva International Salon of Inventions! These pistons are shown in fig. 3 and, as noted, should lead to a very tangible gain both in efficiency and in the “environmental friendliness” of the ICE of the future.
The connecting rod, too, has not yet lost its original shape, although sliding bearings have given way to needle bearings, as was done in the latest motors of the Australian company Orbital. To ensure a gapless joint of the halves of the lower head of the connecting rod, it had to be … previously split, and only then screwed together again.
Single inventors go further here. Lecturer at Moscow State Technical University Bauman in Moscow "broke" the connecting rod in the middle. In V. Konyukhov’s engine (Fig. 4), the connecting rod consists of two parts connected by a hinge to which an additional transverse link from the actuator is attached. By moving this thrust according to a certain law, you can achieve amazing effects: for example, when the crankshaft rotates, the piston can remain in place or even move in the opposite direction! Using a computer, the mechanism was modeled, and incredible opportunities opened up for the inventors. By smoothly changing the magnitude of the suction stroke from zero to the maximum (and the maximum is almost twice the size of the normal piston stroke!), You can control the engine without a throttle that eats up a significant part of the power and obtain much more torque than usual. It is possible to realize a near-adiabatic duty cycle, forcing the mixture to burn at a constant volume. You can leave part of the exhaust gases in the cylinder, which will favorably affect the temperature regime, eliminate detonation and improve environmental parameters. True, the problem remains - how to control the movement of additional traction in accordance with a given program? Obviously, this task is for the future century, and if not the authors themselves, then their followers will be able to successfully solve it.
Having finished with the connecting rod, we turn to the crankshaft. Here, too, no, no, and roller bearings appear, for each neck there are up to … three connecting rods, and power take-off can be at least from the middle of the shaft.
Resourceful Russian inventors do not leave the crankshaft alone. For example, V. Bolotov from Stary Oskol invented an eccentric device that replaces a four-ball conrod sliding bearing. But the main highlight - in its design there is no more top dead center! Due to the displacement of the crankshaft axis and the cunning profile of its neck, the force from expanding gases in the extreme upper position of the piston is directed past the axis of rotation and can do useful work.
All the authors of these inventions are united by one thing: the belief that the implementation of their ideas will greatly improve all the parameters of the internal combustion engine. Will these ideas be in demand? We don’t know. But the fact that our old friend remains the object of the most active design and inventive activity is an indisputable fact. And we can rightfully recall the familiar words: “how many more wonderful discoveries …”
Fig. 1. This FIAT mechanism is already working and really brings benefits in ecology and in power characteristics.
Fig. 2. "To each valve - according to the solenoid and no shafts" - the motto of the Siemens company.
Fig. 3. Kurt Koenig’s “tricky” piston is not too difficult to manufacture, so testing its effectiveness is just around the corner.