Wyniki wyszukiwania - BazTech

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Kształtowanie hydromechaniczne rur na stanowisku badawczym TH

Sadłowska H.

Prace Naukowe Politechniki Warszawskiej. Mechanika

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2013

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z. 253

69

2

Lateral extrusion of tailor welded aluminum alloy pipes with a lost core of low temperature melting alloy

Ohashi T., Liu G.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 32, nr 1

61-65

EN

Purpose: In this paper, the authors employ tailor welded aluminum alloy pipes for lateral extrusion process with a lost core to perform a hollow light-weight-part. Design/methodology/approach: The pipe is welded longitudinally by YAG-laser. “The lateral extrusion process with a lost core (LELC)” consists of lateral extrusion of pipes with a soluble solid core, called the “lost core”, which serves as a plastic mandrel. The process proceeds as follows. First, the pipe cavity is filled with the liquid low temperature melting material composing the lost core. The liquid is then solidified to form the soluble core of the pipe. The material is compressed longitudinally as a composite billet as well as forging, and extruded in the lateral direction. After the pipe is deformed, the lost core is melted and removed. s. The bulge by the LELC is carried out by extruding the material for the lateral direction, however the simple bulge by hydro-forming is done by internal pressure. Findings: The LELC process can make a hollow product having uneven wall thickness without the deformation concentrating on a thinner part of the material, because the circumferential deformation of the material will be performed by its meridian strain. Practical implications: The authors have developed LELC process in which the lost core consists of low-temperature melting alloys and have tried to apply the process to perform bulge process with a tailor-welded pipe having two different wall thickness. Originality/value: Optimum volume distribution is important for light-weight-parts, and employment of tailor-welded blanks is effective technique in sheet metal forming. Combination of employment of hollow shape and tailor-welded blanks seems to be hopeful.

3

FE analysis of tube forming process with experimental verification

Mandic V., Stefanovic M., Zivkovic M., Grujovic N., Misic B.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

303--306

EN

Purpose: of this paper: The paper presents some results of extensive investigation of steel seam-welded tubes forming process, by applying combined treatment of material narrowing and expansion. The objective of executed numerical FE and experimental investigations was to determine the optimal technology for production of tubular product at simple tools and at the standard forming processing machines, without defects and with demanded dimensional accuracy. Design/methodology/approach: Tube forming was done in one phase, in tool with two shaping spherical parts, that enables the expansion of the specimen’s central zone and the filling of the die due to narrowing of the specimen ends, when certain conditions are achieved and with appropriate combination of influential process parameters (outer diameter, height and tube’s wall thickness, as well as friction conditions). Series of physical and numerical FE experiments was performed. Findings: Optimal dimensions of tubular product, with required process stability, were obtained this way. Also, results of experiments pointed out that the best process stability and die filling is achieved with specimens whose surfaces had previously been chemically treated. Results of numerical FE simulations of process are quite verified by experiments. Practical implications: Obtained results have practical significance in solving similar processing problems. It also enables to investigate and broaden the knowledge on stability of these kinds of processes, beyond the scope of experimental investigations. Tubular product that is subjected to numerical-experimental investigation in this paper is prepared by narrowing it at both ends thus excluding the possibility to apply holder inside the tube. Originality/value: Proposed method offers possibility for production of tubular products at simple forming machines and tools, without complex and expensive hydroforming equipment.

4

Obwiedniowe walcowanie rur.

Knap F., Kruzel R.

Rudy i Metale Nieżelazne

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2002

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R. 47, nr 10-11

497-499

PL

Metoda obwiedniowego walcowania przeprowadzana jest na prototypowym urządzeniu skonstruowanym do celów badawczych w Instytucie Modelowania i Automatyzacji Procesów Przeróbki Plastycznej. Kształtowanie rur (w tym również rur stożkowych) odbywa się pomiędzy czterema walcami toczącymi się po obwodzie tej rury. Walce wraz z urządzeniem przesuwają się wzdłuż osi obracającej się rury. Jednocześnie zmniejsza się stopniowo ich wzajemna odległość, a tym samym wzrasta nacisk walców na metal. Przeprowadzono badania redukcji grubości ścianki przy obwiedniowym walcowaniu rur, z zastosowaniem walców o kształcie stożków ściętych.

EN

Envelope rolling of tubes is performed at the prototype machine which has been designed for the research purposes at the Institute of Modeling and Automation of Metal-Forming Processes. Tubes forming, including tapered tubes, takes place between four rolls moving along tube perimeter. The rolls shift together with the machine along the axis of a rotating tube, and the distance between them gradually decreases so that the rolls pressure on the metal formed increases. Tests were made with reducing wall thickness during envelope tubes rolling with the use of truncated cone shaped rolls.