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1

The necessity for using of valves made of light materials in camless valve timing of internal combustion engines

Zbierski K., Siczek K.

Journal of KONES

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2009

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Vol. 16, No. 4

521-530

EN

The essence of the camless valve timing for combustion engine has been discussed in the article. It has been put the attention on the different criteria of distinction for such valve timings. The characteristic features of the camless electric and hydraulic valve timing has been discussed. Basing on the valve lift course the possibility of changes for values of geometrical parameters for valve timing has been explained. The performance of electric and hydraulic valve timing has been described with the help of schematic diagrams. It has been put the attention on significant differences between them. The specific, possible to generation, values of the loading valve forces have been presented. Next, the problems connecting with the increasing of the force loading valve and with the decreasing of masses for moving elements of valve timing have been discussed. The masses of valves made of steel, of TiAl alloy and of ceramic composites have been compared. It has been proven, basing on the camless magnetoelectrical valve timing case, that the valve mass influences the combustion engine speed. It was found that the use of lightweight valves instead of steel valves in the camless valve timing of combustion engines can give the decreasing of the valve mass about 50% in respect to the steel valve mass. The use of lightweight valves instead of steel valves in the camless valve timing, with the same geometry, allows to obtain the maximal engine speed which is greater about 11% in respect to the case of combustion engine with classic steel valves. Thanks to lightweight valves it is possible to decrease the pressure values ofoperating fluid in the hydraulic systems of the drives.

2

The control of valve timing with magnetoelectric actuators

Siczek K., Kuchar M.

Journal of KONES

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2009

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Vol. 16, No. 3

357-365

EN

The new control algorithm for the valve timing in camless combustion engine is presented in the article. The magnetoelectric actuators have been used in the valve timing for analyzed popular combustion engine. Each titanium valve has been connected with the coil of actuator. Such coil can move in the magnetic field, generated in magnet circuit containing sintered Nd-Fe-B magnets, the core, pole shoes and air gaps. The movement of coil can occur when current flows in the coil winds and then electrodynamic force is generated. The nonlinear curves of generated electrodynamic force versus displacement of coil - valve assembly and vs. current in the coil have been computed using FEM method and presented in the article. The new mathematical model has been elaborated to calculate valve lift vs. coil lift for different coil currents and dynamic parameters of the coil. The values of current in coil should be controlled by the elaborated algorithm with the feedback. This algorithm has been based on tracing of position points of valve, during valve movement. The modelled course of valve lift vs. time has been first elaborated, for the needed rpm of engine. Next the first approximated current pulse train has been generated, the movement of the coil - valve assembly could be obtained. The calculated position of valve has been compared with the valve position from modelled course of valve lift vs. time. Basing on obtained difference of valve lift, the next current pulse train has been corrected in such a way, to obtain in any moment the closest position of valve to the one from modelled course. The obtained courses of valve lift vs. time for different modelled courses of valve lift vs. time and vs. rpm of engine have been presented in the article.

3

Motion properties of hydraulically actuated valve train

Zbierski K., Smoczyński M.

Journal of KONES

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2009

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Vol. 16, No. 3

517-526

EN

This paper shows motion properties of hydraulically actuated engine valve train. The experimental model of the hydraulic valve drive is to be presented in this paper. It consists of parts: engine valve, hydraulic actuator and electric control hydraulic distributor, which control the flow of supply oil to the hydraulic actuator. It is hydraulic single-acting drive for valves of internal combustion engines. The methodology of the experimental research is to be explained. The measurements of the valve movement for the different supply pressures and for different opening distributor times were realized in this research. The recorded valve motion was base to detail analysis of velocity and acceleration of the engine valve motion. The researches show possibility of short opening time for typical valve of the high-speed internat combustion engine. Called attention to high speed and stroke against seat, while valve is closing. Especially called attention to possibility to formatting of the course of the valve lift. It may be used for better load exchange in internal combustion engines. The paper points out on the power supply of the system with the working pressure about 15 MPa what gives: smaller delay movement of the timing valve, quicker its opening, and also the large value of stroke of the timing valve.

PL

W artykule opisano właściwości ruchu zaworu rozrządu wymuszanego hydraulicznie. Zaprezentowano model doświadczalny składający się z zaworu rozrządu, siłownika hydraulicznego i rozdzielacza sterującego przepływem oleju zasilającego siłownik hydrauliczny. Jest to model hydraulicznego napędu zaworu jednostronnego działania. Uzasadniono przyjętą metodykę badań oraz przeprowadzono pomiary przebiegów wzniosu zaworu przy różnych wartościach ciśnień zasilających siłownik hydrauliczny i różnych czasach otwarcia rozdzielacza. W oparciu o zarejestrowane przebiegi wzniosów zaworu przeprowadzono szczegółową analizę prędkości i przyspieszeń zaworu. Pokazano możliwość uzyskania krótkiego czasu otwarcia dla typowego zaworu szybkoobrotowego silnika spalinowego. Zwrócono uwagę na dużą prędkość i uderzenie zaworu o gniazdo w chwili jego zamykania. Zwrócono także uwagę na stosunkowo dużą możliwość kształtowania krzywej wzniosu. Może zostać ona wykorzystana dla polepszenia wymiany ładunku w tłokowych silnikach spalinowych. Artykuł zwraca uwagę na zasilaniu układu ciśnieniem roboczym o wartości około 15 MPa, co daje: mniejsze opóźnienie ruchu zaworu rozrządu, szybsze jego otwieranie, a także dużą wartość skoku zaworu rozrządu.

4

Rozrząd bezkrzywkowy czterosuwowego silnika spalinowego na tle rozrządu krzywkowego

Zbierski K., Smoczyński M.

Archiwum Motoryzacji

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2007

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Nr 3

247-271

PL

W artykule omówiono istotę bezkrzywkowego rozrządu czterosuwowego silnika spalinowego oraz aktualny stan badań w dziedzinie rozrządów bezkrzywkowych. Skupiono sie przede wszystkim na rozrządach elektrycznych, eksponując elektryczny rozrząd magnetoelektryczny, skonstruowany wg polskiej koncepcji. Ten rozrząd porównano z mechanicznym rozrządem krzywkowym posługując się ich właściwościami kinematycznymi i dynamicznymi. Dzięki temu wykazano na przykładzie rozrządu magnetoelektrycznego, że rozrząd bezkrzywkowy ma wiele zalet, jakich nie posiadają najbardziej nowoczesne mechaniczne rozrządy krzywkowe.

EN

The paper presents essence of four-stroke engine camless valve timing and up-to-date camless valve timing investigation state. It has been concentrated on electrical valve timing, especially magneto-electric valve timing, as Polish idea. This magneto-electric valve timing has been compared with cam valve timing, using of their kinematics and dynamic properties. It has been shown on magneto-electric valve timing example, that camless valve timing has many good points in comparison with up-to-date cam valve timing.