Wyniki wyszukiwania - Biblioteka Nauki

1

Synthesis of sequential control algorithms for pneumatic drives controlled by monostable valves

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Dworzak Ł. , Mikulczyński T.

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2009

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tom Vol. 9, iss. 3

35-40

EN

Application of the Grafpol method [1] for synthesising sequential control algorithms for pneumatic drives controlled by monostable valves is presented. The developed principles simplify the MTS method of programming production processes in the scope of the memory realisation [2]. Thanks to this, time for synthesising the schematic equation can be significantly reduced in comparison to the network transformation method [3]. The designed schematic equation makes a ground for writing an application program of a PLC using any language defined in IEC 61131-3.

2

Analysis and assessment of measurements results of electric power demand in a model vacuum-assisted moulding installation

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Smyksy K. , Wrona R. , Brzeziński M. , Ziółkowski E.

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tom Vol. 12, iss. 4

135-140

EN

In this article the main problems related with the proper choice of the design and operation parameters of vacuum installation in vacuum moulding system have been discussed. In such system a vacuum are generated using electric-driven vacuum pumps. The aim of the experiment is to evaluate the performance of a vacuum system basing on registered plots of selected electric power parameters of the power-supplying system of the pumps with parallel measurements instantaneous values of pressure in selected points of model stand. The measurements system for power-supply unit has incorporated the recorders of instantaneous current and voltage values. Following the suitable numerical procedure, the experimental data are analysed to yield mathematical relationships between the variations of the generated vacuum pressure levels and variations of selected electric power parameters. According to the authors, the applied measurements system of the parameters of a vacuum-assisted installation may become an effective and easy practical method of evaluating the performance of such installations, used also in industry.

3

Propozycje mechanizacji wybranych procesów odlewniczych

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Gregoraszczuk M. , Fedoryszyn A. , Smyksy K.

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tom Vol. 50, z. 4

121-126

PL

W artykule przedstawiono propozycje rozwiązań mechanizacji wybranych procesów odlewniczych łącznie z charakterystykami stanowisk badawczych. Zaprezentowano projekty przenośników a zwłaszcza podajników, procesów przygotowania materiałów i mas formierskich, rozwiązań formowania oraz wybijania odlewów. Skrótowo przestawiono opracowania i nowatorskie rozwiązania oraz obliczenia przenośników, podajników wibracyjnych, śrubowych, pneumatycznych i pneumatyczno-grawitacyjnych, a także oryginalnego rozwiązania przenośnika wibro-fluidyzacyjnego. Po wcześniejszych pracach dotyczących zastosowania fluidyzacji w procesach suszenia i chłodzenia piasków oraz mas formierskich, opracowano i opatentowano nową, wyjątkowo skuteczną, a zarazem uniwersalną metodę oddzielania różnorodnych zanieczyszczeń. Opracowano projekt, wykonano urządzenie oraz zrealizowano kompleks-we badania. Uzyskano w pełni miarodajne i pozytywne rezultaty skuteczności tej metody. W odniesieniu do procesu formowania, podkreślono możliwości i korzyści wytwarzania form i rdzeni z piasków powleczonych żywicą, z wykorzystaniem fluidyzacji. Ujęto skrótowo aktualne, obszerne i oryginalne prace teoretyczne i badawcze formierek impulsowych. Opracowano prototypowe rozwiązania głowic impulsowych przeznaczonych do zastąpienia mechanizmów wstrząsowych, ciągle szeroko eksploatowanych formierek wstrząsowo-prasujących umożliwiając dalszą ich eksploatację. Na szczególne podkreślenie zasługuje nowa, ekologiczna, pneumatyczna metoda niskociśnieniowego wybijania odlewów. Opracowano koncepcję, zaprojektowano i wykonano stanowisko badawcze wraz z niezbędną aparaturą do badań szybkozmiennych parametrów procesów. Pozytywne i sprawdzone rezultaty tej metody stanowiły podstawę jej opatentowania oraz opracowania urządzenia, a w dalszej kolejności koncepcji zmechanizowanego impulsowego niskociśnieniowego wybijania odlewów. Opisane w tym artykule urządzenia modelowe spełniają także funkcje dydaktyczne.

EN

In the article suggestions of the solutions of mechanization of the chosen foundry processes together with the characteristic data of the testing stands are given. Conveyors designs and specially those concerning feeding devices, preparation processes of materials and moulding sands as well as solutions of moulding and of knocking out of castings are presented. The following problems are briefly dealt with elaborations of novel solutions as well as calculations of conveyors and various types of feeding devices (vibratory, screw, pneumatic and pneumatically-gravitational). The original solutions of vibro-fluidization conveyor is also presented. After the earlier works concerning the application of fluidization in the processes of drying and cooling sands and moulding sands, a new, exceptionally effective and at the same time universal method of separating various impurities from those sands has been elaborated and patented. A project has been made, an installation built and complex tests performed. Fully competent and advantageous results of the efficiency of this method have been obtained. In relation on the moulding processes, possibilities and advantages of manufacturing moulds and cores in resin coated sands with application of fluidization are stressed. Current, coprehensive and original theoretical and research works on impulse moulding machines are shortly discussed. Prototype solutions have been elaborated of impuls heads designed for substitution of jolting mechanism, still largely used in jolt-squeeze moulding machines making their further elaboration possible. A new, ecological, pneumatic method of low-pressure knocking out of castings deserves special attention. A concept has been elaborated, then a testing stand with a neccesary installation for testing the rapidly changing process parameters has been designed and built. Advantageous and checked results of this method have been a basis of its being patented. Then a installation has been made. Later on a concept of a mechanized impulse low-pressure knocking out of castings has been developed. The in this article described pilot installations also serve the didactic purposes.

4

Applications of monitoring of electric power parameters to performance evaluation of a model vacuum-assisted moulding installation

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Ziółkowski E. , Brzeziński M. , Wrona R. , Smyksy K. , Zyzak P.

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tom Vol. 12, iss. 2

267-272

EN

Vacuum conditions in foundry installations are generated using electric-driven vacuum pumps. The purpose of the experiment is to evaluate the performance of a vacuum-assisted system for compaction of moulding sand basing on registered plots of selected electric power parameters of the power-supplying system of the pumps. Model testing done on an experimental vacuum system installation, power-supplied from a system incorporating the recorders of instantaneous current and voltage values. Following the numerical procedure, the experimental data are analysed to yield mathematical relationships between the variations of the generated vacuum pressure levels and variations of selected electric power parameters. Registered and computed values of selected parameters: instantaneous and RMS voltage and current values, active, reactive and apparent power levels and power coefficient allow for diagnosing the adequacy and reliability of the system operation. According to the authors, the applied monitoring of the power parameters of a vacuum-assisted installation may become an effective and easy practical method of evaluating the performance of such installations, used also in foundry plants.

5

Strength measurement of impulse compacted moulding sand

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Mikulczyński T. , Ciskowski S.

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2011

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tom Vol. 11, iss. 1

79-82

EN

Analysis of impulse compaction process shows that during compaction process moulding sand is subject to deformation and changes of total pressure, measured inside compacted moulding sand, represent fading sinusoid. Measured pressure values in stationary states (after compaction process) are equal to the sum of squeezing pressure pc and the pressure resulting from compacting the sandmix pu, which expresses the obtained strength. Therefore experimental research of moulding sands were conducted. Strength factor Rc and pressure pu values were determined as a function of densening degree \delta. Analysis of presented results proves that pu pressure resulting from compacting of the moulding sand expresses compressive strength factor Rc. This confirms that developed methodology permits strength measurements of moulding sand in the mould. Moreover as it is possible to determine pu values with simulation research of developed mathematical model of impulse process it is possible to determine compressive strength factor.

6

A characteristic of design solutions for flask moulding lines

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Fedoryszyn A.

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2007

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tom Vol. 7, iss. 1

5-8

EN

Moulding machines used in manufacture of moulds from synthetic bentonite sands constitute basic equipment of mechanised stands, work centres, and production lines. In the present article, a short characteristic of this equipment was given, basing on the generally accepted criteria of classification taking into consideration novel design solutions and principles of cooperation between individual sub-assemblies. Moulding equipment offered by domestic producers was described with emphasis put on models representative of the distinguished classes and groups.