Andrzej Świątoniowski

Analysis forming the diameter reduction of the tube to the cylinder hydraulic shock absorber

The article presents the process of reducing the pipe and the influence of the shape of the tool on the geometric parameters of the cylinder. Charge material tube is precision welded cold drawn with an outer diameter o 57 mm, made of stainless E355. Reduced pipe is used for cylinder hydraulic shock absorber. Formed cylinder is part of the structure MacPherson strut front suspension vehicle. Tube reduction process is carried out with cold working by using a hydraulic press. Analysed the influence of the diameter of the tool o and profile angle transition into basic the geometric parameters of the deformed cylinder: inner diameter, wall thickness, pipe cylindrical deviation effect. The result of numerical simulation is a map of HMH stress. As well as the effect of the transition profile, angle the value of the tool diameter of the inner pipe, wall thickness and the value of cylindrical deviation effect. In this paper a comparative analysis of the outer diameter, inside diameter and cylindrical deviation effect for physical and numerical studies. Simulation of reduce tubes was carried out with DEFORM 3D software based on the finite element method. Numerical analysis allowed for a detailed knowledge of the specifics of the process and a comprehensive analysis of phenomena that are not possible to explore traditional methods.

Stamping automotive parts with clinch nut process

In this paper authors present joining by forming method for screws and nuts that is more and more used nowadays. They aim to show its basic advantages and problems that occurred during the conducted researches. They concerned both joining process as well as strength tests of a sheet and nuts junction. That process is very often carried out for UHSS and AHSS steels which usually contain decreased plastic properties and increased strength. It usually causes a problem to set up the self-clinching process. Currently, there are a few companies specialising only in this kind of processes, however correct designing of such tool requires taking into account many factors such as choose of joining method by forming and proper connector type.

Springback compensation for a vehicle’s steel body panel

This paper presents a structural element of a vehicle, that is made from High Strength Steels. Application of this kind of materials considerably reduces construction mass due to high durability. Nevertheless, it results in appearance of springback that depends mainly on used material as well as part. Springback reduction helps to reach the reference geometry of the element by using the Finite Element Method software. Authors compared two methods of optimization of die shape. The first method defines the compensation of the die shape only for OP-20 and the second multi-operation method defines the compensation of the die shape for the OP-20 and OP-50 operations. Prediction of springback by the trial-and-error method is difficult and labor-intensive. Designing of dies requires using of appropriate FEM software to make them more economic and less time-consuming. Virtual compensation methods make it possible to receive precise result in a short time. Die compensation with software application was experimentally verified by the prototype die. Therefore, springback deformation becomes a critical problem especially for the HSS steel when the geometry is complex.

The analysis of bottom forming process for hybrid heating device

Przedstawiono nietypową metodę formowania dennic o różnym przeznaczeniu, m.in. do podgrzewaczy wody lub urządzeń ciśnieniowych. Metoda ta pozwoliła na wykonanie dennicy ze stali nierdzewnej w kształcie zgodnym z normą DIN, która określa najbardziej korzystny przekrój poprzeczny dennic pod względem obciążenia ciśnieniem roboczym. Autorzy sprawdzili słuszność przedstawionej metody w sposób numeryczny i eksperymentalny, wytwarzając narzędzie do produkcji dennic o zadanej geometrii. Podczas projektowania i produkcji części wystąpiło wiele problemów, zwłaszcza nadmierne fałdowanie blachy w dużym obszarze części. Jak wykazał eksperyment, brak analizy numerycznej oraz dużego doświadczenia w projektowaniu tego typu elementów skutkowałby wykonaniem części o znacznym pofałdowaniu, które nie nadawałyby się do zamontowania w zespole z częścią walcową. Wiele narzędziowni stosuje sposób ciągnienia elementów o powierzchni kulistej poprzez dodatkowe operacje wyoblania lub stopniowania tłoczenia, co znacznie podnosi koszt produkcji części. Autorzy przedstawili i porównali dwie metody formowania przedmiotów o zarysie kulistym i parabolicznym, potwierdzając eksperymentalnie słuszność wyboru metody przewijania blachy z odpowiednią siłą docisku. Zastosowana metoda umożliwia wytwarzanie części w jednej operacji ciągnienia oraz poprzedzającej operacji wykonania okrągłego wsadu metodą cięcia laserem lub wodą. Ogranicza to koszty wytworzenia oprzyrządowania do jednego narzędzia, które może być umieszczone na dowolnej prasie o sile nacisku powyżej 2000 kN. SŁOWA KLUCZOWE: formowanie stali, analiza symulacji, MES

Compensation of springback deformation in sheet metal forming analysis

Process of metal forming in automotive parts construction becomes more and more demanding due to tightened up tolerance and trials to realize very complex and in many cases unworkable design in mass production. Moreover, it is required to cut and limit costs of die production and simultaneously keep high quality. Furthermore, construction elements are more often produced from materials which belong to High Strength Steel or Ultra High Strength Steel. Application of this kind of materials considerably reduces construction mass due to high durability. Nevertheless, it results in appearance of springback effect. Springback value depends mainly on used material as well as part geometry and in extreme cases deviation value from target part might reach in some areas high level. Designing of dies requires using of appropriate Finite Element Method software to make them more economic and less timeconsuming. Therefore, analysis of forming process alone is not enough to be taken into account. During the design process, it is needed to include the die compensation to reach optimized blank sheet. Prediction of springback effect by tryout method and then correction of deviation is difficult arduous and painstaking. Virtual compensation methods make it possible to receive precise result in a short time. This way gives a huge economic advantage eliminating useless milling and allows producing of die just in time. Optimization process can relate to individual operation as well as take into consideration intermediate stages in the final result, at the same time increasing the accuracy. Die compensation with software application was experimentally verified by prototype die.

Forming of Automotive Parts with Nuts Clinch Process in Comparison to Welding of Nuts

In this paper authors present joining by forming method for screws and nuts. Self-clinching nut process was compared to a traditional nut welding method after drawing the requested shape in order to analyse quality of junction. That process is very often carried out for High Strength Steels which usually contain decreased plastic properties and increased strength. It usually causes a problem to set up the self-clinching process. Currently, there are a few companies specialising only in this kind of processes, however correct designing of such tool requires taking into account many factors such as choose of joining method by forming and proper connector type. Despite many difficulties, this method allows for joining hard welded steels and most of all for minimization of operations amount in mass production. Operations of joining by forming of nuts and screws, gives significant savings of anticipated costs with simultaneously guarantees high static and dynamic strength.

THEORETICAL AND EXPERIMENTAL ANALYSIS OF ROLL BENDING OF HALF RING OF GAS TURBINE

The article presents an analysis of forming half reinforcement ring housing the gas turbine. The ring is made of INCONEL alloy 617 material, which is based on nickel-chromium-cobalt-molybdenum alloy characterized by high strength and resistance to oxidation at high temperatures as 1100-1200°C. Square bar of dimensions 50x50 roll bending at half ring with a diameter of 1500 mm, an intermediate product is prepared for machining. The forming process is divided into two operation. The first operation is to pre-bending the rod. The second operation is to roll bending to the radius determined by the deflection. The article presents the map of reduced stress of HMH for two operations, obtained from the numerical simulation based on the finite element method. It also presents the load on the tools during the entire process. Physical tests were carried out on the device for roll bending steel profiles DURMA PBH 125. The article sets out the minimum allowances technology needed to complete half of the ring. A comparison of deviations, outside diameter of the ring, was resulting from the spring back in the study of physical and numerical simulations. We also compared the flatness deviation of the ring resulting in the research. The results of theoretical research have confirmed good agreement with physical examinations. The research provided an opportunity to develop technologies forming of half ring on the above machine of bending steel profiles.

The Influence of Cold Forming Conception on the Springback Magnitude

Cold forming, especially for steels of increased mechanical properties, encounters problem with a springback. Most of the tools require compensation of that effect, however it is not always feasible in a conventional way. In some special cases such as twisting springback, compensation of a tool remains an ineffective method of solving the problem. This paper aims to investigate the behaviour of springback deviation which may be reduced using the change of forming conception such as: crash forming, holding and stamping or stamping with pad. The results lead to an in-depth understanding of the design process and parameters for advanced high strength components. It is immensely important for tool shops which usually have only few weeks to make a tool. The essence of designing and numerical simulations must be emphasized. Without them some problems with twisting springback may be encountered during trial test what would involve labour absorbing corrections and some extra costs. Therefore, it is crucial to pay attention to forming conception, as using it we can obtain entirely different