Search results for "Metalworking"
showing 10 items of 49 documents
Design and control of a novel 3D casting manipulator
2010
This paper focuses on casting manipulation and presents an innovative mechanism that allows objects placed in a three-dimensional space to be reached with a relatively small robot. Casting manipulation is a technique by which a robotic end-effector is thrown and its ballistic flight is controlled through a tether cable so as to reach a target object. Previous work presented a solution that is viable only when the position of the target object is perfectly known or aligned with the throwing plane. Our work extends the technique by use of a novel mechanical design of the arm, and a suitable control scheme for the flight of the end-effector, which makes it applicable for objects placed at gene…
Visual-based Feedback Control of Casting Manipulation
2006
In this paper, we present a method to control casting manipulation by means of real-time visual feedback. Casting manipulation is a technique to deploy a robotic end-effector at large distances from the robot’s base, by throwing the end-effector and controlling its ballistic flight using forces transmitted through a light tether connected to the end-effector itself. The tether cable can also be used to retrieve the end-effector and exert forces on the robot’s environment. Previous work has shown that casting manipulation is able to catch objects at a large distance, proving it viable for applications such as sample acquisition and return, rescue, etc. In previous experiments, the position o…
Influence of the channel design on the heat and mass exchange of induction channel furnace
2011
PurposeThe purpose of this paper is to present in‐depth numerical modelling of heat and mass exchange in industrial induction channel furnace (ICF).Design/methodology/approachThe turbulent heat and mass exchange in the melt is calculated using a three‐dimensional (3D) electromagnetic model and a 3D transient large eddy simulation method. The simulation model has been verified by flow velocity and temperature measurements, which were carried out using an industrial sized channel inductor operating with Wood's metal as a low temperature model melt.FindingsThe ICF is well‐established for melting, holding and casting in the metallurgical industry. But there are still open questions regarding th…
Aspects of Improving the Cost-Performance Ratio for the Manufacturing of Small-Size Cast Parts
2010
Abstract The paper analyses some of the commercially available solutions for casting small-size metallic parts and outlines possible solutions that would reduce the cost of such systems while maintaining a high performance level. high performance level. One typical application area for small-size parts is human prosthetics, so the commercial casting machines analysed here are used mainly in this application domain. The paper shows how high-cost systems added to the machines for providing protective atmospheres can be replaced by low-cost solutions with the same results in terms of part quality. Moreover, a solution is described that avoids the typical drawbacks of the currently used casting…
Friction Stir Welding of AA6082-T6 T-joints: Process Engineering and Performance Measurement
2006
In the paper the authors present the results of a wide range of experiments on T-parts. First, friction stir welding process engineering has been developed with the aim of determining the specific process parameters that make up the soundness of the obtained T-parts. Then the performance of the obtained T-joints has been compared with T-joints obtained by metal inert gas welding and extruded T-parts. The parts have been tested utilizing a customized bending test with the aim of highlighting their behaviour both in elastic and plastic fields.
The evaluation of springback in 3D stamping and coining processes
1998
Abstract An effective predictive technique of the elastic springback in a fully 3D 90° V-punch V-die bending process is presented. This is based on a combined approach in which an explicit finite element code was used to simulate the loading phase of the process whilst an implicit procedure was used to analyse the springback phase. Two different punches with a nose radius of 4 and 8 mm were used. An increase in the springback ratio with the coining load was observed with the lower nose radius. Conversely, an increase in the springback ratio with the coining load up to a peak value (>1), corresponding to a force of about 20 kN, followed by a decrease in the springback ratio with increasing t…
Interactive simulation of one-dimensional flexible parts
2006
Computer simulations play an ever growing role for the development of automotive products. Assembly simulation, as well as many other processes, are used systematically even before the first physical prototype of a vehicle is built in order to check whether particular components can be assembled easily or whether another part is in the way. Usually, this kind of simulation is limited to rigid bodies. However, a vehicle contains a multitude of flexible parts of various types: cables, hoses, carpets, seat surfaces, insulations, weatherstrips... Since most of the problems using these simulations concern one-dimensional components and since an intuitive tool for cable routing is still needed, w…
Real-time Control of Metallurgic Processes
1996
The careful control of the liquid metal solidification and the solid shell growth is of central importance in all metallurgic processes. These have a considerable influence on the formation of cracks and other defects which can be formed in the cast material. To ensure defect free products, the liquid metal is to be cooled down according to a pattern which depends i.e. on metal grade, product dimension, cooling speed and machine design. On the other hand, the control of the liquid/solid interface is a key element in optimising the liquid solidification with respect to good productivity. So, the heat transfer plays a very important role in metallurgic casting processes, especially when casti…
Analysis and Design of Induction Liquid Metal Processes Using Advanced Numerical Modelling
2019
Comprehensive knowledge of the turbulent flows, heat and mass transfer processes in the melt of induction applications is required to realize efficient metallurgical processes. Therefore, the process oriented development, design and optimization of induction furnaces for melting and casting of metals require praxis oriented simulation and analysis of the complex in-stationary turbulent melt flows and temperature distributions as well as the heat and mass transfer processes in the liquid metal. The studies, presented in this paper, demonstrate the possibilities of using advanced three-dimensional transient numerical modelling for successful simulation of the melt flow as well as heat and mas…
Comparison of the effect of different surface treatments on the bond strength of different cements with nickel chromium metal alloy: An in vitro study
2017
Background For success of any indirect metal restoration, a strong bond between cement and the intaglio surface of metal is imperative. The aim of this study is to evaluate and compare the effect of different surface treatment on the tensile and shear bond strength of different cements with nickel–chromium alloy. Material and Methods 120 premolars were sectioned horizontally parallel to the occlusal surface to expose the dentin. Wax patterns were fabricated for individual tooth followed by casting them in nickel chromium alloy. 60 samples were tested for tensile bond strength, and the remaining 60 for shear bond strength. The samples were divided into three groups (of 20 samples each) as pe…