Wyniki wyszukiwania - BazTech

1

Prototypowe urządzenie do automatycznego prostowania smukłych wyrobów drążonych

Gąsiorkiewicz Maria, Szkudelski Szymon, Bączek Marcin, Lulkiewicz Jarosław, Ziółkiewicz Stanisław

Obróbka Plastyczna Metali

|

2019

|

T. 30, nr 3

179--188

PL

W procesie wytwarzania długich wyrobów, to znaczy takich, których wymiary wzdłużne są znacznie większe od wymiarów przekroju poprzecznego (np. rury o zmiennym przekroju) pod wpływem procesów obróbczych tj.: skrawanie, kształtowanie, obróbka cieplna dochodzi do krzywienia i wypaczenia detali. W związku z tym konieczne jest wprowadzenie do procesu technologicznego operacji prostowania. Jedną z najczęściej stosowanych metod prostowania jest przeginanie odbywające się na prasach. W pracy przedstawiono zautomatyzowane urządzenie do prostowania smukłych wyrobów drążonych, zbudowane w ramach projektu realizowanego przez Sieć Badawczą Łukasiewicz – Instytut Obróbki Plastycznej wspólnie z Zakładami Mechanicznymi Tarnów. W ramach współpracy opracowano koncepcję stanowiska do prostowania opartego na korpusie ramowym. Geometria korpusu została opracowana przy wykorzystaniu modułu do analizy numerycznej. Wykonane symulacje pozwoliły na dobranie przekrojów, rozstawów i geometrii żeber oraz sposobu łączenia tak, aby odkształcenia sprężyste korpusu podczas pracy były jak najmniejsze. Powstało prototypowe urządzenie umożliwiające wykonanie na jednym stanowisku procesu prostowania, pomiaru prostoliniowości zarówno na średnicy zewnętrznej, jak i w środku otworu. Proces prostowania oparty jest na pomiarze prostoliniowości wewnątrz otworu. Aby możliwe było wprowadzenie czujnika pomiarowego do otworu, wstępnie prostowano i przegnano rurę, korzystając z pomiaru zewnętrznego. Proces prostowania kończy się po wykonaniu pomiaru wewnątrz otworu i uzyskaniu jego prostoliniowości w zakresie wymaganej tolerancji. W pracy przedstawiono również pierwsze wyniki badań prostowania, które prowadzono w celu synchronizacji pracy systemu pomiarowego ze sterowaniem.

EN

In the process of manufacturing long products, those whose longitudinal dimensions are substantially greater than the dimensions of the cross-section (e.g. pipes with variable cross-section), when processes are applied, i.e.: machining, forming, heat treatment, pieces are warped and twisted. Because of this, it is necessary to introduce a straightening operation into the technological process. One of the most commonly applied straightening methods is contraflexion on presses. This paper presents an automated machine for straightening of slender, hollowed products, built as part of a project realized by the Łukasiewicz Research Network – Metal Forming Institute jointly with Zakłady Mechaniczne Tarnów. As part of this collaboration, a concept of a straightening station based on a frame body was developed. The body's geometry was designed using a numerical analysis module. Conducted simulations made it possible to select rib cross-sections, spacing and geometry, as well as the joining method, so that the body’s elastic deformations during work were as low as possible. And so, a prototype machine enabling performance of the straightening process, linearity measurement on the exterior surface and at the center of the hole in one station was created. The straightening process is based on linearity measurement inside the hole. For it to be possible to insert a measuring sensor into the hole, the pipe was pre-straightened and contraflexed using external measurement. The straightening process ends after a measurement is taken inside the hole, and its linearity is found within the required tolerance range. This paper also presents the first results of straightening tests, performed in order to synchronize the operation of the measuring system and control.

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

|

2009

|

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

Lateral extrusion of a cross fitting with a lost core

Ohashi T., Ito H., Shinozaki K., Ito S., Watari H.

Journal of Achievements in Materials and Manufacturing Engineering

|

2007

|

Vol. 24, nr 1

413-420

EN

Purpose: Lateral extrusion process with a lost core for cross fittings is suggested. At first, cavity of tube is filled up by low temperature melting alloy. Then low temperature melting material is solidified to be the "lost core". The third, the material is extruded for lateral direction to be a cross-fittings. After deformation, low temperature melting alloy is melted and removed. The authors discuss its deform mechanism in this paper. Design/methodology/approach: Experiments and numerical analysis with ANSYS9.0. Findings: Extrusion defect is caused at the center of the cross on the inner wall of the pipe because of volume constancy when the branch diameter close to the initial pipe diameter. In such the case, contact between pipe and die surface is unstable and the branch part is not stretched enough, then it causes wrinkles. In such the case, it is better to provide more pressure against the head of branch projection. Research limitations/implications: The effect of the relationship amongst mechanical properties of the pipe and lost core is to be examined in future. We must seek better material for the lost core that is cheaper, easier to remove, clean and safer for the man and environment. Practical implications: This methodology is suitable for production of the hollow products having constant sections for lateral direction. Originality/value: The above result helps the economical production of hollow products with simple equipments.

4

Analytical and experimental study on lateral extrusion of cross fittings with a lost core

Ohashi T., Ito H., Shinozaki K., Ito S., Watari H.

Journal of Achievements in Materials and Manufacturing Engineering

|

2006

|

Vol. 18, nr 1-2

399--402

EN

Purpose: The authors discuss deform mechanism of lateral extrusion process with a lost core for cross fittings. Outline of the is as follows: At first, cavity of pipe, or channel material, is filled up by liquid of low temperaturę melting material, for instances, low temperature melting alloy, ice (or water) and wax. Then low temperature melting material is solidified to be a soluble core of pipe. Authors call this soluble core the ‘lost core [1-4].’ The third, the material is compressed longitudinally as a composite billet, and extruded for lateral direction. After deformation, low temperature melting material is melted and removed. The authors think the process is suitable for production of cross-fittings because such the product has constant sections for lateral direction. Design/methodology/approach: The authors have examined the process with experiments [1] and numerical analysis with ANSYS9.0. Findings: The feature of the process is revealed. Extrusion defect is caused at the center of the cross on the inner wall of the pipe because of volume constancy when the branch diameter close to the initial pipe diameter. In such the case, contact between pipe and die surface is unstable and the branch part is not stretched enough, then it causes wrinkles. In such the case, it is better to provide more pressure against the head of branch projection. Research limitations/implications: In future work, the effect of the relationship amongst mechanical properties of the pipe and lost core is to be examined. In addition, the authors will seek better material for the lost core that is cheaper, easier to remove, clean and safer for the man and environment. Practical implications: Throughout the above research, authors conclude the suggested process is useful for making cross fittings, and the process can be useful on the other hollow products. Originality/value: The above result helps design of the economical process for fittings. The process requires only simple equipments.