Tibor Szalay

Budapest University of Technology and Economics · Department of Manufacturing Science and Engineering

Today’s technological advancements aim to make small-sized, compact products. This trend creates requirements for higher accuracy of cutting processes, where the minimum uncut chip thickness presents itself as a technical limit of removing chip in a controllable way. The following research aims to estimate the minimum uncut chip thickness and how i...

In CNC milling, the feed rate scheduling is a frequently used method to increase machining quality and efficiency. Among the benefits of feed rate scheduling, this paper focuses on controlling the tool load and optimizing the machining time. Although the advantages of feed rate scheduling are undeniable, some areas remain still to be addressed. In...

In the automotive industry robots are widely used in the entire range of the production. In most cases, the isolation of the robots from human involvement can be easily achieved, by physically separating the production line or its elements from the workers (for example by a fence). In other cases, e.g.: in testing, measuring, quality control, mixed...

Since the appearance of computers, engineers recognized their potential. Due to this fact, engineers are utilizing computer usage during their daily tasks. When it comes to analysis, simulation is one of the most valuable tools an engineer can apply. In this paper a mixed integer programming-based description and a discrete event-based model is pre...

For high-speed machining, special tool paths are required wherewith the tool load is well-controlled, and the path is sufficiently smooth. One of the most effective solutions for controlling the tool load is to keep the cutter engagement constant. For this purpose, advanced tool path generating cycles are available in CAM systems. In case of slot m...

This book comprises the select proceedings of the International Conference on Future Learning Aspects of Mechanical Engineering (FLAME) 2020. This volume focuses on several emerging interdisciplinary areas involving mechanical engineering. Some of the topics covered include automobile engineering, mechatronics, applied mechanics, structural mechani...

In the case of 2.5D rough milling operations, machining efficiency can significantly be increased by providing a uniform tool load. This is underpinned by the fact that uniform load has a positive effect on both tool life and machining time. Unfortunately, conventional contour-parallel tool paths are unable to guarantee uniform tool loads. However,...

Contour parallel milling strategy is still widely used in 2.5D roughing operations. However, in the case of equidistant tool paths, the tool load strongly depends on the contour's shape. The paper presents how the cutter engagement can be determined for different contour milling conditions to describe the interaction between the workpiece and the m...

The prevalence of micro-holes is widespread in mechanical, electronic, optical, ornaments, micro-fluidic devices, etc. However, monitoring and detection tool wear and tool breakage are imperative to achieve improved hole quality and high productivity in micro-drilling. The various multi-sensor signals are used to monitor the condition of the tool....

Prior to a critical value of uncut chip thickness (UCT) or the so-called minimum uncut chip thickness (MUCT), the micro milling process is affected by ploughing which causes deterioration of surface quality and reduction of tool life. Stringent surface quality is the major concern during micro milling of P-20 die steel as it has wide application in...

Nowadays, modern measurement technologies are essential parts of the modern production lines. In case of size control of the manufactured parts, besides accuracy and speed, taking into account industry 4.0 approach, the integration of the measurement results into the quality system, the feedback and the statistical processing of them are the greate...

The term Industry 4.0 refers to the fourth generation of industrial revolution, that can be derived from the closer cooperation between automatization and information technology, as well it is the collective name of the period leading to a fundamental change in production methods. However, there are a number of factors that may be considered in ord...

It is a well-established fact that when equidistant tool paths are used for 2.5D milling operations tool load varies based on the functions of path curvature. This phenomenon makes the optimal selection of cutting parameters more difficult, and the local load peaks are also detrimental to machining stability and tool life. Numerous publications add...

Automated stone manufacturing has undergone considerable development in recent years. Thanks to international research dealing with the cutting, sawing and grinding of different natural stones, processing time shortens and tool-life lengthens. However, the process of stone milling has not been extensively examined yet, primarily because of the nove...

Carbon fibre reinforced polymer (CFRP) composites have excellent specific mechanical properties, these materials are therefore widely used in high-tech industries like the automobile and aerospace sectors. The mechanical machining of CFRP composites is often necessary to meet dimensional or assembly-related requirements; however, the machining of t...

Carbon fibre-reinforced plastic (CFRP) is an often-used structural material in the high-tech industries, like aerospace, wind turbine, sport, automobile, robotics and military. Due to both the growing application area of composites, and the advanced construction requirements, the used thickness of the CFRP plates increases, and the necessity of dri...

Carbon fibre-reinforced polymer (CFRP) composite laminates have good specific material properties, these composites are therefore widely used by the high tech industries. Machining operations are often necessary in order to achieve dimensional requirements. However, CFRP is a difficult-to-cut material due to its non-homogenous and anisotropic featu...

Carbon fibre-reinforced plastic (CFRP) has good specific mechanical properties, it is, therefore, an often used structural material in the high-tech industries. Due to the anisotropy and inhomogeneity of CFRP, the machining properties are highly depending on the cutting directions. Based on previous experimental works, a new trochoid tool patch was...

Many applications are available for the syntactic and semantic verification of NC milling tool paths in simulation environments. However, these solutions – similar to the conventional tool path generation methods – are generally based on geometric considerations, and for that reason they cannot address varying cutting conditions. This paper introdu...

Tool condition monitoring systems are essential in micro-milling applications. A tool’s slenderness requires high-precision monitoring systems for online measurements. In most cases, tool health is indirectly estimated by processing and analyzing the cutting process parameters. In that sense, the main challenge lies in the proper selection of the p...

Though the circular pocket milling seems to be an old manufacturing task, but it is nice to have through investigation among the different machining strategies, because in spare part production a frequent repeatable shape behaviour. As usual, at pocket milling the roughing operation is critical, because the excess material is in closed area to the...

The miniaturization of parts of devices is continuously growing, therefore the micro machining processes, such as micro milling is gaining more importance, too. The aim of micro milling is preparing of structures in size range of 1…999 µm. The kinematics and tool geometry are very similar to that at conventional milling, but there are many differen...

The micro electrical discharge machining is a novel technology applicable for the production of geometries which cannot be made by any other technologies assuming the material is electrically conductive. The machining of electrically conductive ceramics becomes possible by this way. Hole machining into these materials has high importance, however t...

The machining behaviour of carbon fibre-reinforced polymer (CFRP) is not a very extensively researched topic. With respect to this material, it must be noted that it is difficult to find its analogy in traditional metal machining because of its non-homogenous and anisotropic features. With the help of the latest technology, it is possible to machin...

Parts made by powder metallurgy generally do not require subsequent machining operations. However, further machining of these sintered parts cannot be avoided in case of special, complex geometries. The goal of the research discussed in this paper is to create an easy-to-use, time-efficient and cost-efficient method to describe the secondary machin...

Specific cutting force is a frequently used parameter to classify and describe the energetic environment of mechanical machining operations. It defines the ratio of cutting forces and theoretical chip section during machining. This definition makes it possible to create general technological models for precise process planning. Classical models of...

Micro scale machining process monitoring is one of the key issues in highly precision manufacturing. Monitoring of machining operation not only reduces the need of expert operators but also reduces the chances of unexpected tool breakage which may damage the work piece. In the present study, the tool wear of the micro drill and thrust force have be...

The miniaturization of parts of devices is continuously growing, therefore the micro machining processes, such as micro milling is gaining more importance, too. The aim of micro milling is preparing of structures in size range of 1…999 µm. The kinematics and tool geometry are very similar to that at conventional milling, but there are many differen...

Production features of micromachining ceramic workpieces using electrical-discharge machining are studied. The effect of pulse duration, breakdown voltage, voltage gain factor, peak current strength, and working voltage for electrical-discharge machining of VOK71 ceramic workpieces on roughness at the bottom of a channel and electrode-tool end wear...

This article discusses technological aspects of the micromachining of semifinished products made of a high-density electrically conducting ceramic with the use of electrical discharge machining (EDM). It is established that an increase in pulse frequency during the EDM cutting of channels in semifinished products made of an oxide-carbide ceramic is...

Powder metallurgy is one of the possible competitive options among those up-to-date replication technologies that are able to produce final shapes with no need for subsequent machining. However, there are some special geometries which require the subsequent machining of certain parts produced by powder metallurgy. These include grooves, threads and...

Nowadays there are many applications in NC technology to investigate the tool path in simulation environment. However, these semantic and syntactic analyzes don't give any information about the cutting conditions which can be continuously vary during the machining. This paper will be introduce our developed method to solve this missing engineering...

Pocket machining can be considered as complicated and difficult manufacturing task because of the closed cutting geometry. Although the machining of the simple shaped pockets such as circle, square, rectangle or regular convex polygons can be solved using the NC cycles, both the NC macros and the CAM algorithms approach the pocket manufacturing pro...

In order to achieve high quality and productivity in microdrilling, monitoring of the prefailure phase and detection of tool breakage is very important. In the present work, vibration signals have been studied during micro drilling operations to monitor the prefailure phase of the micro-drills. These signals have been processed in time domain and t...

In this paper a Voronoi diagram based tool path generation algorithm is introduced that automatically calculates the 2.5 D rough milling path for pocket with arbitrary contour of circular and linear boundary lines. The process generate the Voronoi diagram gains special focus and the elaborated method is explained in detail. To simplify the calculat...

A study is made of the effect of the operating regime in electrical-discharge machining (EDM) on the condition and defectiveness of the surfaces of “blind” small-diameter holes drilled in parts made of an oxide-carbide ceramic. The physical pattern that is characteristic of the formation of these surfaces is determined, the morphology of the damage...

In order to achieve high quality and productivity in microdrilling, monitoring of the prefailure phase and detection of tool breakage is very important. In the present work, vibration signals have been studied during micro drilling operations to monitor the prefailure phase of the micro-drills. These signals have been processed in time domain and t...

The research described in this article was carried out for the purpose of developing a quantitative marker for defining the average edge chipping rate of milled granite surfaces and for testing and proving whether this quantitative marker can effectively be applied. Another aim of the research was to test the applicability of the developed measurem...

Work shows the entire process of palette bow tipper construction. The process of modeling, preparation and the process of production are described. Parts were prepared for processing on machines by the use of CAD/CAM software following the rules of deformation technology. With the demonstrated procedure, the production process was optimized, and th...

Micro hole machining refers to the process of drilling holes with a diameter of less than 1 millimeter. This paper compares three commonly used technologies: mechanical drilling, laser machining and electrical discharge machining. All of these techniques were analyzed based on an experimental measurement of dimensional accuracy, circularity, burr f...

Results are presented from a study of the effect of the regimes used for electrical-discharge machining on the accuracy of small-diameter holes made in parts composed of high-density ceramics. It is established that increases in the breakdown voltage, voltage gain, peak current, and working voltage have different effects on changes in the diameter...

Results are presented from a study of the effect of the technological regimes used in electrical-discharge machining on the accuracy of small-diameters holes formed in parts made of a high-density ceramic. It is established that increases in the frequency and duration of the pulses in the electrical-discharge machining of holes in an oxide-carbide...

Nowadays micro hole drilling is more and more applied machining operation. Because of less than 1 millimeter diameter, and of the relatively high thrust force, micro drills are more easily break than conventional ones. In this paper the experiences of micro drilling tests are summarize in order to demonstrate that measuring thrust force is efficien...

Machining and more specifically face milling are productive ways of material shaping. Predictive models are very important for effective: quick, easy-to-use and accurate process planning. There are many industrial and scientific researches about modelling the prominent process parameters of machining, notably the machining forces. The main cutting...

This research paper aims to investigate the drilling capabilities of the sintered powder metallurgy parts. Due to their special properties, these materials are of distinguished importance in today's world. Exploiting said properties enables us to create self- lubricant bushing as well as special alloys. In order to evaluate the investigated paramet...

This paper aims to introduce the development of a control system implemented for a force-feedback gripper mechanism, as well as the results of the experiments carried out on the device. The achievements shall be used in additional research related to medical purpose grippers, such as artificial hands. The aim of the current research is the improvem...

Nowadays, there is a growing need for parts, which are made directly to final size because of the favorable cost of the production. However technologies that keep the high geometry accuracy and good mechanical properties are required such as moulding, forming or powder metallurgy. This is the reason, why these technologies are improved continuously...

One of the advantages of powder metallurgy technology is that we may produce the final geometry of the required part saving considerable time and cost. However there are several applications that require parts need additional machining for example when the product contains threads, cross bore or slots. In these cases cutting of the hard and porous...

When the mechanistic cutting force model is applied for cutting force prediction during multi-axis milling, the accurate determination of the contact area between the cutter and the workpiece and the fast processing of the gained geometry data play an important role. During the evolution of the material removal simulation techniques the discrete z-...

The introduced cutting model uses the widely applied mechanical-dynamical differential Lagrange model together with one of the most popular experimental force model (Kienzle-Victor model) in order to provide the more accurate demonstration and simulation of cutting processes. To increase the reliability of the results the authors considered as much...

In this paper a new method for instantaneous cutting force prediction is presented, in case of sculptured surface milling. The method is executed in a highly parallel manner by the general purpose graphics processing unit (GPGPU). As opposed to the accustomed way, the geometric information of the work piece-cutter touching area is gained directly f...

The representatives of the newest generation graphics hardware are called GPGPUs (General-Purpose Graphics Processing Units), as they are suitable for executing non-graphical (e.g. general-purpose), massively parallelized computations besides the conventional graphical tasks. In 2008, at the University of Pécs, a research project started for exploi...

The appearance of general-purpose graphics processing units (GPGPUs) has opened the door to use graphics hardware for processing massively parallelized computations and simulations apart from common graphics tasks. Material removal simulation consists of a vast number of SIMD (Same Instruction on Multiple Data) operations, so it can be expected tha...

The evolution of GPUs (graphics processing units) has been enormous in the past few years. Their calculation power has improved exponentially, while the range of the tasks computable on GPUs has got significantly wider. The milestone of GPU development of the recent years is the appearance of the unified architecture-based devices. These GPUs imple...

In the paper, the air gaging system has been examined. The length measurement with pneumatic devices equipped with piezoresistive pressure sensors has been described. The conditions of the air expansion in the flapper–nozzle area would affect the stability of the air pressure in the measuring chamber, which is registered by pressure sensor. As a re...

The overall design scope of most microgrippers developed in recent years lacks a systematic mechanism design approach. Accordingly, the main objective of this investigation is to establish a new design concept in order to enhance the design scope of microgrippers. Using a systematic design procedure which particularly stresses planar compliant mech...

Importance of telepresence application increases in the field of manufacturing. In production the main activities are divided; the locations of management, design, manufacturing and services are separated sometimes to diverse countries or continents. The development of information technologies and telecommunication made possible the sense of presen...

An active research and development co-operation has been established to formulate a consortium with academic and industrial partners to work on various aspects of digitising factory IT processes. This paper details some of the research activities devoted to implementing tele-presence features with interactive multimedia solutions.

The paper presents a realized automated quality assurance system for the final assembly of a magnetic valve. The realization project joined to an international research project sponsored by the European Union however the quality assurance was not in the frame of that project. The system includes: (1) the supervision of the assembly cell and operati...

Production and application of technical surfaces have a great importance in industry. Prediction of the surface quality or selection of the appropiate machining would be useful for both of the costumer and the producer. Two different methods are introduced in this paper for providing simple tools of the production of the required surface. Applicati...

The authors, who are experts of the Technical University of Budapest Department of Production Engineering, work on the solutions of monitoring and sensoring problems in the CIM Pilot System. The results and the further tasks are discussed in this paper. Increasing the reliability and flexibility of the system were successfully realised with a share...

This study was carried out to establish the feasibility of the Fourier analysis and fuzzy logic for tool and process monitoring of a milling operation. The dynamics of the measured cutting force component and vibration of a milling machine is investigated to establish the response of the signal variations due to tool wear, tool breakage, entering,...

In the recent years the applications of artificial neural networks (ANNs) became used frequently in monitoring systems. This paper presents two possible applications of ANNs in the field of flexible manufacturing system (FMS). First the paper surveys the theory of backpropagation algorithm, then a tool breakage monitoring system is detailed and the...

When using robots in automated production it is necessary to use different end-effectors (grippers, tools, measuring units) built in the last robot wrist for handling, welding, machining, assembling, etc. the workpieces. The end-effector is one of the main parts of the robot, which connects the robot with the working environment and gives the possi...

A témakörben a pályázat támogatási évei alatt, úgy ítéljük, hogy sikerült átütő eredményeket elérni. Jelentős eredménynek tartjuk, a korábbi kutatásokra épülő új módszerek publikálását a "MECHATRONICS" (Nagy-Britannia) és a "Robotics and Computer-Integrated Manufacturing" (USA) folyóiratokban. Különösen jelentősnek tartjuk a Robotics and Computer I...

A kutató munka során azt vizsgáltuk meg, hogy az anyag szemcseméretének finomításával hogyan változik a forgácsolt felület topográfiája. Forgácsolási kísérleteinkhez ultrafinom- és szubmikronos szemcseméretű (5000-100 nm) próbatesteket állítottunk elő intenzív képlékeny-alakítással, valamint ezt kiegészítő hőkezelési eljárással. Kísérleti anyagként...