Christian von Koenigsegg smiles: “A few years ago, a GM engineer said that we would never see an engine without a camshaft. this moment we are driving a car without a camshaft. Turns out he was wrong.” Welcome to the future.
Under the wing of Koenigsegg lives a small company called Freevalve. What they do is just incredible. You see, in engines there is such a thing as a camshaft. It has cams that open and close valves during rotation. This element has been present in engines since their inception.
The system works unquestioningly, but the valves are not always open or closed. There is an intermediate stage, which is not effective. However, engineers stubbornly think that a camshaft is the only solution available. How is it? Why not go crazy and come up with some absurd idea - for example, related to compressed air?
Freevalve engine got rid of the camshaft and housing throttle valve, replacing them with pneumatic actuators on each cylinder. This concept has been around for a long time. The ships use an electromagnetic valve opening mechanism. This means that the concept has proven itself. It remains to reduce it to the scale of something more ordinary.
This system provides completely independent control of each cylinder and each valve. If you have 4 valves, then only two open when necessary. With a conventional camshaft, this cannot be achieved. Freevalve can disable one cylinder, two, three, and so on.
Another surprising thing is that the system is able to work in different modes. On low revs the engine can be operated as a two-stroke, which greatly improves power delivery: 3000 rpm feels like 6000 rpm. The engine can work on the Miller cycle (like the Mazda Xedos 9): although it is complex, it is much more efficient. Well, plus everything, the engine can run on several types of fuel. Christian emphasized that gasoline and diesel can get along together. Of course, we are not talking about their merging into a single mixture. Two separate tanks would be a great idea.
The most impressive part, however, is that with current engines, the system will provide 30% more power and torque and 50% more fuel economy. It will also reduce the size of the engine. So a compact engine built from the ground up can compete with much larger engines.
Christian described the camshaft operation as "playing the piano with a broom", while the Freevalve is genuine "finger play". You will have a higher level of control. Since all elements work independently, one cylinder or actuator can fail and the engine will continue to run for many more years.
During a short ride in the Saab 9-5 Freevalve used to develop its technology, the Jalopnik columnist felt like normal car. Isn't that the best praise for any innovative method? At low revs, the engine feels a bit like a diesel, but over time its work smoothes out. The system works, but software engine is still in its infancy. The Swedes have to improve it, but they have time. Before us is a fifth-generation system, and a sixth is already looming on the horizon.
Christian does not believe that this technology will save the engine internal combustion from extinction, but it can significantly extend his life. Just imagine that this idea could have come to fruition 10 years ago. Where would the ICE be today?!
Candidate technical sciences D. SOSNIN.
In the scheme of the gas distribution mechanism of the Arkhangelsk there is centrifugal regulator, shifting the moments of opening and closing of valves depending on the speed of the crankshaft.
The Arkhangelsky valve opens when an electromagnet is activated and closes with a return spring.
Using two electromagnets to move the valve allows you to get rid of the return springs.
IN new design the gas distribution mechanism is located on the side of the cylinder block. The use of long solenoids increases the stroke of the valves, allowing it to be adjusted over a wide range.
Historically, it has been domestic automotive industry developed in an attempt to catch up with Western colleagues. Truly original models (they include, say, “Victory”) can be counted on the fingers. And yet, interesting developments, the introduction of which would allow our automakers to successfully compete with foreign ones, appear. We bring to the attention of readers a story about an unusual mechanism proposed by D. A. Sosnin, Associate Professor of the Department of Electrical Engineering and Electrical Equipment, Moscow Automobile and Road Engineering Institute (State Technical University). The device allows you to abandon the use in the engine of the usual camshaft and at the same time flexibly control the valve timing and valve stroke.
WHERE ELECTRONICS FAILS
Any automaker strives to ensure that the internal combustion engines (ICE) on his machines work in optimal mode: provided maximum power, torque uniformity, minimum fuel consumption, least toxicity exhaust gases. However, so far no one has been able to fully achieve this, since the improvement of some characteristics leads to the deterioration of others. Recently, however, significant progress has been made thanks to the use of automated engine control with the widespread use of electronics.
When compiling a program for the control system, the engine is entered into a stable operating mode on a special test bench and all parameters are successively corrected so that for this mode they provide the best output characteristics. The same is done in other modes. The results are recorded in permanent memory electronic block in the form of a multidimensional diagram, with the help of which control signals are subsequently formed for each of the parameters.
For example, in the integrated electronic system “Motronic” (Germany), which controls fuel injection and ignition, there are five such diagrams: to correct the ignition timing, fuel injection time, recirculation valve position (a device that returns part of the exhaust gases to the cylinder for better afterburning of fuel ), ignition coil energy storage time and throttle position. This system uses engine speed, engine torque and temperature, as well as voltage as input parameters. battery. At the output, the compliance of the engine speed with the torque and the content of carbon monoxide in the exhaust gases are controlled.
Unfortunately, the car has a system that cannot be controlled by even the most sophisticated car electronics. This is a gas distribution mechanism with a rigid kinematic connection between the crankshaft and camshaft.
Experts believe that classic engine perfect enough and if sometimes it does not work well, it is only because it “suffocates from its own exhaust”; it is worth giving the engine more oxygen, allowing it to “breathe deeply”, and there will be no alternative to it.
You can help the engine if you could shift the opening and closing moments of the valves, primarily the intake ones. I remember how back in the early 70s of the last century, Baltic racers
The republics won the competition, achieving engine speeds of up to 3000 rpm at idle and up to 8000 rpm at idle. full throttle. Subsequently, it turned out that they got hold of a camshaft template, welded the cams and then manually finished their shape. With such camshafts, engines gave out high performance(power and torque), but only on high speed. For sports cars this is good, but for the “private” it is unacceptable. Nevertheless, this fact indicates a significant role of the delay or advance of the phase of the valves.
How to make the valve open and close at the moment that corresponds to the optimal operation of the engine? It is clear that it is necessary to control the valve timing depending on the speed, position and load of the crankshaft. The traditional camshaft does not solve this problem.
Within small limits, the valve timing ratio can be adjusted using mechanical, electromechanical, hydraulic, pneumatic valve actuators. But the most promising is the electromagnetic drive, electronically controlled. With it, you can not only optimize the operation of the engine, but also expand its functionality. Thus, a four-cylinder engine can be made to act like a two- or three-cylinder by changing the order of valve operation; it works more evenly under variable loads, consumes less fuel on maximum speed at a given power. Such an engine will not have problems with changing the direction of rotation of the crankshaft.
At first glance, everything looks very simple, but for some reason solenoid valves on cars are still found only in experimental developments.
VALVE ARKHANGELSK
An attempt to implement an idea solenoid valve with flexible management was undertaken in the middle of the 20th century by Professor MADI V. M. Arkhangelsky. The electromagnets were turned on and off when the contacts connected to the camshaft cams were closed and opened. The valve was returned to its place by a spring.
In the Arkhangelsky scheme, a centrifugal regulator was provided on the camshaft. When changing the speed, it shifted the position of the cams and caused the valves to open and close ahead of time. Thus, the regulator played a role feedback. This made it possible to do without program control, which, by the way, then could not be.
Unfortunately, despite the elegance of the scheme, it was not possible to create a workable design. The fact is that the valve must operate quickly and close reliably, and therefore a return spring with high rigidity is required. Accordingly, a powerful electromagnet is needed, which consumes a significant current from onboard network car. In those days, there were no powerful semiconductor valves, and metal contacts quickly burned out when switching high currents. Finally, when the valve was closed by a return spring, the valve head hit the seat hard, which caused noise during the operation of the gas distribution mechanism and led to frequent breakdowns valves.
ONE IS GOOD AND TWO IS BETTER
You can get rid of many of the shortcomings inherent in the Arkhangelsky valve if you put two electromagnets instead of one - opening and closing. A similar scheme was developed by one of the students of Togliatti State University in a graduation project under the guidance of Doctor of Technical Sciences, Professor V. V. Ivashin.
In this version of the design, springs are not needed, and therefore electromagnets can be smaller in size and power - after all high current is consumed only when closing and opening the valves, and ten times less current is sufficient to hold them.
But most importantly, now you can do without a camshaft at all, since a programmable controller can set the response time and current strength through the electromagnet winding - electronic device, usually on a microprocessor, work manager engine and other vehicle systems.
In NAMI, under the guidance of Candidate of Technical Sciences A.N. Terekhin, they began to carry out research and design development of a gas distribution mechanism with electromagnetic drive valves based on the M-412 engine. As a result, a working model of a gas distribution mechanism with two-way electromagnets on eight valves was created. But since the beginning of the 1990s, funding has ceased, and promising development lost in the archives.
A few years ago, work on a new gas distribution mechanism was resumed at the Volga Automobile Plant under the leadership of P. M. Prusov, the chief designer of AvtoVAZ. Yes, among the topics All-Russian competition"Russian Automobile" (see "Science and Life" No. 12, 2002) was announced "Development of an electromagnetic drive system for gas distribution valves for a 16-valve VAZ engine." Two projects were submitted to the competition, but both were completely “out of business”, and they were not even considered.
Meanwhile, Japanese, American and (with the greatest success) German automakers began to work on improving the electromagnetic valve drive. Already in 2002 BMW company began testing on a real 16-valve gas distribution engine with an electromagnetic drive of all valves.
COMPETITIVE DESIGN
At the same time, the development of electromagnetic gas distribution valves was started at the Department of Electrical Engineering and Electrical Equipment of the Moscow State Technical University (GTU).
Although in the West we were not recognized as competitors: they say, “were 10 miles behind” (in the jargon of race car drivers they say that they are two laps behind, which means weaklings), but the author has patented a design that solves most of the problems inherent in electromagnetic drives.
In it, instead of bulky electromagnets mounted above the valves, long solenoids are used. The braking of the core in a long solenoid is realized not by hard stops, but by edge stops. magnetic fields, and the drive becomes silent. In addition, the valve stroke can be arbitrarily large and adjustable. The reciprocating movement from the electromagnet to the valve is transmitted through the rod and the rocker arm. Due to this, the drive can be installed not above the cylinder block, but on its side surface. As a result, the height of the engine is significantly reduced, and for cooling and lubricating the drive parts are used standard systems car.
Now it's up to the engine builders. If it is possible to translate the idea into metal, a torquey and economy car, which will also meet the most stringent requirements for exhaust cleanliness.
Hypercars Koenigsegg are cars whose production began not long ago, but they have already loudly declared themselves and found their place in the class of such cars. There were quite a few such moments in history, but these odious projects ended in failure. But he survived and competed with the luminaries of the world of super motors.
For 15 years now, Koenigsegg engineers and designers have been working on a project for a camshaftless engine that will not have a throttle. But the very fact of the absence of a throttle valve has already been proven by BMW and Fiat engineers, but they have not been able to finalize the design to perfection. The Bavarians removed the damper, installing instead electronic system intake valve controls. The Germans' problem was that they used an additional electric motor to implement their project, which complicated the entire structure and steadily led to additional breakdowns. Fiat engineers faced another problem that they still cannot solve (high pump losses). The Swedes took a different path, leaving the Bavarians and Italians in the background of history, since their system was able to control all the valves separately, independently of each other.
So what is a Swedish engine without a camshaft?
Everybody's problem big engines- gluttony. Therefore, the Swedes decided to make the engine for their hypercars economical and powerful at the same time. Many have heard about powerful Swedish engines, one 1500-horsepower engine in Agera-R is worth something, but fuel consumption and engine dimensions leave much to be desired. It was decided to take as a basis the engine developed by one American self-taught mechanic Carmelo Scuderi. The essence of the idea is that he divided the cylinders into working and auxiliary. The workers burned the fuel mixture and released the exhaust gases, and the auxiliary let the fuel in and compressed the mixture. The cylinders were connected by bypass channels, in which there were two valves - expansion and compression. The process safely dispensed with the camshaft.The Koenigsegg engineers decided to upgrade the Scuderi engine and implement everything in one cylinder, but for this they needed to develop a progressive model of the valve actuator. It must be fast, accurate and without sticking. By 2000, they built the first engine with a similar scheme of operation, which consumed methane and hydrogen. The level of emissions of harmful gases into the atmosphere was so low that only electric motors are below it. Everyone was immediately interested in such a unit, and especially its actuator, although it was bulky, pneumatic, had a lot of vibration and a high noise level. After 3 years, the engineers completely modernized it, added a hydraulic valve lock and reduced the size. It took several more years of upgrades until a fully finished prototype could be installed on standard engine. The Saab 95 became the first such car. Engine power increased by 30%, fuel consumption decreased proportionally (also by a third).
In describing the principle of operation of their motor, the Swedish designers used a funny allegory. They suggested imagining an ordinary piano-shaped engine and trying to play with a stick or a mop. And in the Koenigsegg engine, the interaction of fingers and keys was positioned directly, without an intermediary. Also, for greater persuasiveness, one can compare a mono-injection and a distributor injection system, when fuel is injected directly into working area cylinder bypassing the distribution frame. The effectiveness of individual influence on various processes in the engine has been proven for a long time and is used by many manufacturers. But how to make the valves let in and out something without special device that governs all cycles? For this, fast actuators (electronic pushers) are needed.
The control unit sends a signal to the actuator, which opens and closes the valve. The pushers are equipped with pneumatic springs with an adjustable level of stiffness and valve position sensors. The entire algorithm for the operation of cylinders and all auxiliary systems The engine is controlled by a computer, thanks to which you can change the valve timing as you like and as many times as you like. You can turn off any number of cylinders at any time.
The motor can work alternately in different cycles, depending on the tasks and the load level. It can operate in standard mode for all internal combustion engines, it can be economical, it can be super economical, it can work in a cycle with variable degree compression (Hedman cycle). These cycles cannot be implemented within the design of a standard internal combustion engine, so manufacturers have to choose. For example, the famous Hedman cycle, which can only be used with the presence electronic control lift and valve opening time, can alternately work with the Otto principle (traditional thermodynamic cycle of all engines) or Atkinson ( increased savings fuel).
The versatility of such an engine affects the fact that it can run both on gasoline with different octane ratings, and on diesel fuel. In addition, it is 30-50% more economical, a third more powerful, it has higher torque, it weighs less and is more compact in size. Light weight and compact dimensions at more power and low consumption, will give Koenigsegg hypercars a huge advantage over competitors. The issue of noise level, power consumption and vibrations remains unresolved. But of course the installation cost. The price of such engines is very high and can only be reduced by mass production on civilian cars. In addition, such an internal combustion engine can be used not only as the main one, but as an additional one in hybrid versions.
If the Swedes manage to get rid of high level noise, vibration and they will be able to optimize energy costs, then the unit will be in high demand, since such an engine is economically justified and expedient. And in the presence of stable demand and mass production, the price may fall to optimal levels.
Inventor Christian von Koenigsegg proved automotive world, the camshaft is not needed in the engine - this part is superfluous. An engine without a camshaft has a place to be in the automotive industry.
Christian was born in 1972 in Stockholm, Sweden. Even as a child, he loved to disassemble household appliances with a desire to change something in the design of the devices, and as a teenager he already established himself in his quarter as a jack of all trades and a talented craftsman.
He was the first to predict that chips would replace CDs, he even wanted to patent the design of this device, but at that time no one was interested.
He also invented a lock for fastening wooden plates, but no one understood him either, even his father, who works in the woodworking industry. Subsequently, other companies patented a similar patent and earned many millions on it.
At 22, he became involved in the creation of cars, founded the company Koenigsegg Automotive AB, and in 2002 the Koenigsegg CC car was put into production.
In 2005, this car was listed in the Guinness Book of Records as the fastest stock car(388 km/h). And his car Koenigsegg CCXR is the leader in terms of power-to-weight ratio. Automobile brands Koenigsegg One1 is the leader in acceleration, it can accelerate to a speed of 300 km/h. in 11.92 sec.
Between two elements
Christian von Koenigsegg himself drives an old Saab and smiles slyly. And the reason for his smile is simple. His car has the only old series engine in the world…. ATTENTION! Without camshaft and gas distribution mechanism, timing belt and rocker arms.
In the Saab engine, more precisely in its block head, there are native 16 valves. But each valve is controlled by a separate node, and each of these devices receives a command to close or open the valve from the engine control unit independently of the others.
This is the main know-how - the actuator. Each valve is controlled by such a drive-actuator. The unit is a pneumo-hydraulic-electric Koenigsegg system. The secret is that valves open with pneumatics and close with hydraulics.
The air and hydraulic lines are under constant pressure and are always ready to open or close. The electrical part of the assembly bears control function to one action or another.
Equipped with such a gas distribution system, engines are capable of developing up to 20,000 rpm from the very a high degree purging and filling cylinders with fuel mixture.
These nodes are cooled and lubricated standard systems engine.
The most, in my opinion, the highest achievement of the actuator from the Koenigsegg subsidiary Freevalve is that it can be installed on almost any car engine and even a motorcycle. And on high speed engine motorcycle with a speed of 16000 and a car with diesel engine from 3500 rpm.
Breathe full cylinders into all valves
Consider the schedule of the valves. He looks fantastic to me. Where is there at…
The red graph shows work inlet valve i.e. opening and closing. It shows that there are no soft parabolas as in conventional engines, simple and ingenious, opened - closed and no intersections with the exhaust valve (blue graph) for purge. Graphs do not intersect and have almost right angles. It is fantastic!
All volumes of gases enter and exit in a shorter period of time than in conventional engines, thanks to which the intake and exhaust phases do not intersect. Thanks to this, two times, this is a fact !!!, the environmental performance of the engine has been improved twice. This is truly a BREAKTHROUGH!
Play the piano rocker
Von Koenigsegg says that to use instead of Freevalve is to play the piano with a rocker instead of playing with your fingers.
What is programmed by the inventor for each valve?
Listed in order of importance:
- in all modes, regardless of engine speed, the intake is the most optimal volume fuel mixture, the most correct modes of opening and closing valves, which is impossible in;
- the Freevalve system allows you to change the parameters: the moment and duration of the valve opening. In this regard, in a conventional system, this is not possible, but here it is possible to revise any parameter;
- the ability to easily control engine power, turn off any cylinder, create any work program for each cylinder. In the classics, this can be done, but only through complex mechanical operations associated with mechanical switching on cams of a different camshaft configuration;
- there is no sad elliptical cam graph when the valves open and close smoothly, there are no moments when the intake and exhaust valves are open at the same time. There are no curves here, only broken lines. The actuator works quietly in this mode up to 10,000 rpm;
- And now the main thing: 30% more torque, 30% less fuel consumption and 50% less harmful exhaust!
Three cylinders, eighteen valves
Incorporating actuators into a motor design can significantly reduce its size. And that's not it. You can increase the number of valves per cylinder, and even separate the exhaust gas paths, for example, send part to the turbine, and part to the muffler. Part of the valves can be used in the compressor system.
Engine without camshaft. Down with stereotypes!
What else does such a system give. Due to the fact that the engine can be more compact, the absence of a camshaft saves space, which means that the body design can also be changed.
And the plus that was given to us significantly greater moment, i.e. power, the required horsepower can be extracted from a smaller number of cylinders, respectively, the size will become even smaller. And hide a small motor under the seat))).
This system can be installed at any time on any engine of any manufacturer, throwing out the camshaft with all personal belongings. Increase power by 30%, and this is not enough!
But the most exotic thing is to convert it to a two-stroke, while increasing the power by 2 times !!! ... just by switching the program!
Von Koenigsegg is working on the idea of a car with two tanks for different fuels, and with different systems food, gasoline and diesel, and even with the transition to biofuels.
But the top of Koenigsegg's fantasy is of course a pneumatic hybrid - it's something! What is he dreaming about?
About how, according to a special program, a certain valve configuration is set up, in which the internal combustion engine turns into a compressor.
The principle is this: when braking by the engine, air is pumped into the cylinder, accumulating pressure. And then use this air to move or accelerate the car, also use it in turbocharging, if you need to temporarily increase engine power.
Independent valves, it is also reliability. In this arrangement, the timing belt will not break and the pistons will never meet and break each other.
The same old Saab that Christian drives has already traveled 60,000 km., He has experienced heat and cold and does not feel very bad. Its block head is native, but converted to independent valves, everything superfluous has been removed from it and the necessary channels for pneumatics and hydraulics have been machined.
Saab test drive experience: Behaves like a diesel at 3000rpm, torque is crazy.
My opinion
I am wildly delighted with this invention! Engine without camshaft!!! What potential of settings opens up.
Engine modes can be composed like music.
And what insane performance can be pulled out of a conventional engine !!!
There are no words, friends! There is no limit to human genius! An engine without a camshaft, who would have thought that this is possible!
See you online!
The eminent inventor Christian von Koenigsegg decided to prove to the entire automotive world that the gas distribution mechanism, the basis of the internal combustion engine, is nothing more than an extra expensive detail.
As a simple Swedish boy, Koenigsegg took apart household appliances, hoping to find a way to improve them. He is said to have been the first to invent audio players with on-chip memory, but in a CD-crazy world, no one listened to him. He is also credited with the idea of a snap lock for floor laminate. And again, a few years later, the invention was patented by someone else. True or not, we will not undertake to judge. But today, Christian is listened to very carefully, and he learned patent law by heart.
As a simple Swedish boy, Koenigsegg took apart household appliances, hoping to find a way to improve them. He is said to have been the first to invent audio players with on-chip memory, but in a CD-crazy world, no one listened to him. He is also credited with the idea of a snap lock for floor laminate. And again, a few years later, the invention was patented by someone else. True or not, we will not undertake to judge. But today, Christian is listened to very carefully, and he learned patent law by heart.
In 2005, a car named after Christian von Koenigsegg officially became the fastest serial car on the planet: experts from the Guinness Book of Records recorded a speed of 388.87 km / h. Koenigsegg CCXR has become the world's best sports car in terms of weight and power. Koenigsegg One:1 is the leader in the category " best overclocking”, reaching a speed of 300 km / h in just 11.92 seconds.
While the most efficient sports cars in the world break record after record, their creator drives around in an old Saab 9-5, smiling slyly. Under the hood, the “old man” has the only engine in the world that has no camshaft, no cams, no valve lifters, no notorious timing belt. And, unlike the frenzied Koenigsegg, intended only for the rich and famous, motors with individual valve drives promise to be the first truly mass creation of the Swedish inventor.
An old Saab, which got an experimental version of the timing belt with independent valves, drove 60,000 km with it, having seen both summer heat and 20-degree frosts. The cylinder head was made from the original "Saab", throwing out everything superfluous from it and turning new channels for hydraulics and pneumatics. Our colleagues from Jalopnik.com took a ride on the "old man" and noted that at speeds up to 3000 rpm it shows diesel habits - it characteristically taps the valves and produces crazy torque.
Between two elements
In the cylinder head of the test Saab, as expected, 16 valves work. Each is driven by a separate actuator and each is commanded to open or close by the engine control computer independently of the others.
The actuator is the core know-how of Freevalve, subsidiary Koenigsegg. Many developers have tried to supply each valve with an individual drive and control them independently of each other, including many world-famous automakers. The most obvious solution in the form of linear electric motors (solenoids) does not lead to the desired result: small motors do not have enough power to accelerate the valves to desired speeds(20,000 openings and closings per minute), there are problems with cooling and reliability.
Christian von Koenigsegg does not go into details of how his actuator works, but he is happy to explain the general concept of the "pneumatic-hydraulic-electric actuator". The valves are opened by pneumatics and closed by hydraulics. Both the pneumatic and hydraulic systems are constantly pressurized and ready to deliver maximum power to the valve. Task electric drive— just in time to supply air or oil to the valve. The problem of cooling and lubrication is solved by itself: the most loaded parts of the drive are serviced by the corresponding systems of the internal combustion engine itself.
The beauty of the Freevalve actuator is that it fits almost any automotive or motorcycle engine. Whether it's a high speed motor racing motorcycle, spinning up to 16,000 rpm, or a truck diesel rattling at 3,500 rpm, the same drive will fully meet their needs. The race bike valve is made of light alloy, so the energy of the actuator easily accelerates it to high speeds. The truck valve is large and heavy, but high speeds he doesn't need.
On the piano with a yoke
“Using a traditional camshaft instead of a Freevalve is like playing a piano with a rocker instead of fingers,” says von Koenigsegg. What kind of problems does the inventor want to solve by programming the behavior of each valve separately? We list them in ascending order of interest.
The most obvious: for different engine operating modes (primarily crankshaft rotation speed), there is an optimal composition of the air-fuel mixture, right moments opening and closing valves. Traditionally, this problem is solved using a variable valve timing mechanism (for example, VTEC): the entire camshaft rotates slightly relative to the timing gear (timing), and all valve opening and closing moments are shifted forward or backward.
The red graph shows the intake valve opening curve, the blue graph shows the exhaust valve. It is clearly seen that the valves stay in the fully open position for as long as possible - the graphs have an almost rectangular profile, while with a conventional timing they would be more like parabolas. The required volumes of gases pass through the Freevalve valves in less time than usual, so short intake and exhaust phases do not overlap. This is the reason for the almost two-fold improvement in environmental performance.
The problem with VTEC lies in the limited number of modes, while individually controlled valves allow you to revise the optimal set of parameters for any, even the smallest change in speed. But the main thing is that Freevalve allows you to change not only the moment, but also the duration of the valves opening.
But what if we want to flexibly control engine power by turning off part of the cylinders? IN modern engines the task is solved using a very complex mechanism: for each valve, two cams are provided that replace each other, moving along the camshaft. One cam provides regular work valve, the second is responsible for the operation of the cylinder in the "standby mode". Freevalve valves allow you to turn on any program for any cylinder at any time without any mechanical tricks.
But still the main problem The traditional timing lies in the elliptical shape of the cam, due to which the valve is almost never open or completely closed. Instead, it always either opens smoothly or closes smoothly, which lowers it. throughput. Moreover, this feature leads to the fact that at certain moments the inlet and exhaust valves are open at the same time, and this adversely affects the environmental performance of the engine.
Freevalve valves allow the cylinder head and the engine itself to be made much more compact. But this is far from the only layout advantage. It is possible to increase the number of valves per cylinder by dividing the functions between them. For example, to send one part of the exhaust to the supercharger turbine, and the other part directly to the catalyst, for environmental reasons. Special valves are also useful in order to turn the car into a pneumatic hybrid.
Christian von Koenigsegg demonstrates the valve opening curve on the monitor of a special device. It resembles a rectangle: the valve opens abruptly, is held open, and then abruptly closes. This is not the eternal sad ellipse of a traditional valve. It is especially interesting that the curve retains its angularity even for high revs(up to 10,000 rpm) - the actuator has enough power to open and close the valve really quickly.
Perhaps it was the latter feature that contributed the most to the free-valve test engine delivering impressive results in tests: it delivers 30% more torque, consumes 30% less fuel, and delivers a 50% reduction in emissions.
Down with canons!
Freevalve is more than meets the eye. Firstly, the system can significantly change the appearance of the car. Camshaft and valve lifters take up a lot of space in the cylinder head, and they weigh a lot. Four cylinder engine the Freevalve is similar in size and weight to a three-cylinder. If we take into account that independent valves give a significant increase in torque, then two cylinders can be dispensed with altogether. And then the tiny motor can be hidden even under the seat.
The system allows you to switch the engine to an exotic work cycle at any time, even Miller, like on Mazda, even Atkinson, like on Prius. Why be modest: if desired, the motor can become two-stroke in the blink of an eye, almost doubling the power! Von Koenigsegg dreams of cars with two fuel tanks and power supply systems: for gasoline and diesel. For the transition to biofuels, the flexibility of settings is also relevant.
But the most interesting fantasy of the inventor is a pneumatic hybrid. Using a special valve configuration, it is possible to turn the internal combustion engine into a compressor, which, when braking, will pump air into the cylinder, accumulating pressure. Then compressed air can be pumped into the cylinders, accelerating the car, or used as a powerful analog of a turbocharger, briefly increasing engine power.
Perhaps the most unexpected property of an engine with independent valves is reliability. Every driver is afraid of a broken timing belt: if the piston “catches up” with the valves, the same will happen in all other cylinders. An expensive cylinder head, and with it pistons, and possibly connecting rods with crankshaft will be seriously damaged.
And with Freevalve, everything is simple: no timing - no problems! If one cylinder suddenly "knocks" - all the rest will remain safe and sound.
