Rigid body dynamics in optimization of the machine tool vibroisolation

Modern design of the machine tool treats the suspending parts as a crucial element of the effective vibration isolation. Therefore the suspending items are specifically developed and subjected to extensive tests before being applied on real objects. These elements ensure accurate levelling and appropriate vibration damping. Usually selection of inadequate support element causes intensive disturbing effects in machining. The paper presents dynamics analysis of the machine tool suspended on flexible mountings. The overall analysis is conceived on a rigid body dynamics. This method enables selection of an optimal supporting configuration. Further on such an effective suspension design prevents a need for expensive monitoring of the dynamic characteristics of the mechanical system, i.e. machine tool and supports. The paper explores dynamics of a real, flexibly supported machine tool. Results are obtained with the assistance of the "SUPPORT" software. Finally the theoretical and computational statements are approved throughout extensive site measurements on the machine tool body with appropriate instrumentation

Application of CAD/CAE/CAM Systems in Permanent-Mold Casting Improvement

This paper presents the application of CAD/CAE/CAM systems at the improvement of the manufacturing the flotation balls for grinding ore. Flotation balls need to satisfy the appropriate requirements in terms of dimensional, chemical, mechanical and physical properties. These properties are directly related to technology of ball manufacturing, in this case - permanent-mold casting technology. Software tolls from the group of CAD/CAE/CAM systems were used for designing the casting parts, casting and feeding systems, mold and simulation of permanent-mold casting process. Based on results of casting process simulation the casting process in real industrial conditions was realized. After the casting process, testing of casting parts has been performed. The testing gave satisfactory results, so the presented methodology, based on CAD/CAE/CAM systems, is acceptable for manufacturing program in foundry

CAD/CAM DESIGN AND GENETIC OPTIMIZATION OF FEEDERS FOR SAND CASTING PROCESS

The paper proposes methodology of feeder design and optimization for sand casting process. Casting part is a part of excavator buckets, i.e. holder of the cutting tooth. Process of design and optimization is based on the application of the rules, which are the result of many years of work researchers in the field of metal casting. Computer Aided Design (CAD) is used as a methodology in the design of feeders. Genetic Algorithm (GA) as an artificial intelligence technique is used in the optimization process of the feeder geometry. Computer Aided Manufacturing (CAM) is used as methodology that involves numerical simulation of the casting process. Numerical simulation is used to verify the validity of the optimized geometry of the feeding system

Rigid body dynamics in optimization of the machine tool vibroisolation

Suvremeni razvoj alatnih strojeva tretira oslonce kao presudne elemente u vibroizolaciji. Zbog toga su oslonci posebno razvijeni i podvrgnuti opsežnim testovima prije primjene na realnim objektima. Oni osiguravaju precizno niveliranje i amortizaciju vibracija. Neodgovarajući izbor oslonaca uzrokuje neželjene efekte u procesu obrade. Rad prezentira analizu dinamike alatnog stroja oslonjenog na fleksibilne oslonce. Ukupna analiza je koncipirana na dinamici krutih tijela. Ova metoda omogućava izbor optimalne konfiguracije oslanjanja. Ovako efikasan razvoj oslanjanja eliminira potrebu za skupim nadzorom strojnog sustava, tj. alatnog stroja i oslonca. U radu je dana analiza dinamike fleksibilno oslonjenog alatnog stroja u realnim uvjetima. Rezultati su dobiveni pomoću softvera SUPPORT. Konačno, teorijski i računarki rezultati potvrđeni su opsežnim mjerenjima na alatnom stroju, odgovarajućom mjernom opremom.Modern design of the machine tool treats the suspending parts as a crucial element of the effective vibration isolation. Therefore the suspending items are specifically developed and subjected to extensive tests before being applied on real objects. These elements ensure accurate levelling and appropriate vibration damping. Usually selection of inadequate support element causes intensive disturbing effects in machining. The paper presents dynamics analysis of the machine tool suspended on flexible mountings. The overall analysis is conceived on a rigid body dynamics. This method enables selection of an optimal supporting configuration. Further on such an effective suspension design prevents a need for expensive monitoring of the dynamic characteristics of the mechanical system, i.e. machine tool and supports. The paper explores dynamics of a real, flexibly supported machine tool. Results are obtained with the assistance of the "SUPPORT" software. Finally the theoretical and computational statements are approved throughout extensive site measurements on the machine tool body with appropriate instrumentation

Koncept napredne tehnologije izrade specijalne tehnološke opreme za procesnu industriju

The paper deals with the manufacturing technology of refiner plates that are used for preparing the paper pulp in the paper industry. The manufacturing technology consists of casting, heat treatment, machining and balancing. Special attention is given to the selection of materials used for casting of the refiner plate segments, and to defining the appropriate heat treatment in order to make the tools with optimal technical characteristics. Defining the technological parameters for the process of plain grinding of the refiner plate as well as noting the few negative effects occurring during the grinding process are presented in the paper. The paper also pays attention to the influence of machining technology on the micro-surface of the cutting elements, because it has a significant influence not only on the cutting edge but even on the surface quality and the total consumption of energy in the cutting process.U radu je opisana tehnologija izrade diskastih pločastih noževa koji se koriste za pripremu papirne mase - pulpe u industriji papira i celuloze. Tehnologija izrade sastoji se iz lijevanja, toplinske obrade, strojne obrade i uravnoteženja. Naročita pažnja u ovom radu posvećena je definiranju materijala koji se koristi za lijevanje pločastih noževa i projektiranju odgovarajuće termičke obrade kako bi dobili alate potrebnih tehničkih karakteristika. Definiranje tehnoloških parametara za proces ravnog brušenja pločastih noževa i neke negativne pojave u procesu brušenja također su dati u ovom radu. Rad ukazuje na utjecaj tehnologije obrade na mikropovršinu reznih elemenata, a koja ima bitan utjecaj kako na rezni rub tako na kvalitetu površine i ukupan utrošak električne energije u procesu mljevenja

Effect of the degree of plastic deformation on the thermal electromotive force of Cu-X5crni1810 steel thermocouple

The thermal electromotive force (TEMF) and the thermal electromotive force coefficient (TEMFC) of the thermocouple consisting of a copper wire and an (X5CrNi1810) steel wire plastically deformed under tension or bending conditions were found to increase with increasing degree of plastic deformation. The increase in the degree of deformation disturbs the microstructure of steel due to increases in the density of chaotically distributed dislocations and internal microstress, resulting in a decrease in the electron density of states near the Fermi level. Through the effect of thermal energy, annealing at elevated temperatures up to 300°C leads to microstructural ordering along with simultaneous increases in the free electron density of states, TEMF and TEMFC. Based on the temporal change of the TEMF, the kinetics of microstructural ordering was determined. During the initial time interval, the process is a kinetically controlled first-order reaction. In the second time interval, the process is controlled by the diffusion of reactant species

Integrisan proces proizvodnje abrazivnih reznih elemenata bagera u rudarskoj industriji

The paper presents an integrated production process for excavator cutting elements in the mining industry based on modern software systems for the optimization and management of casting process parameters through simulations. The concept involves the virtual manufacture, practical implementation of the established technological process and quality control of final castings i.e. excavator cutting elements. The presented production methodology reduces the time required to develop and manufacture the new product compared to the traditional methods of prototype testing.Publishe

Dinamika sustava krutih tijela u optimizaciji vibroizolacije alatnih strojeva

Modern design of the machine tool treats the suspending parts as a crucial element of the effective vibration isolation. Therefore the suspending items are specifically developed and subjected to extensive tests before being applied on real objects. These elements ensure accurate levelling and appropriate vibration damping. Usually selection of inadequate support element causes intensive disturbing effects in machining. The paper presents dynamics analysis of the machine tool suspended on flexible mountings. The overall analysis is conceived on a rigid body dynamics. This method enables selection of an optimal supporting configuration. Further on such an effective suspension design prevents a need for expensive monitoring of the dynamic characteristics of the mechanical system, i.e. machine tool and supports. The paper explores dynamics of a real, flexibly supported machine tool. Results are obtained with the assistance of the "SUPPORT" software. Finally the theoretical and computational statements are approved throughout extensive site measurements on the machine tool body with appropriate instrumentation.Suvremeni razvoj alatnih strojeva tretira oslonce kao presudne elemente u vibroizolaciji. Zbog toga su oslonci posebno razvijeni i podvrgnuti opsežnim testovima prije primjene na realnim objektima. Oni osiguravaju precizno niveliranje i amortizaciju vibracija. Neodgovarajući izbor oslonaca uzrokuje neželjene efekte u procesu obrade. Rad prezentira analizu dinamike alatnog stroja oslonjenog na fleksibilne oslonce. Ukupna analiza je koncipirana na dinamici krutih tijela. Ova metoda omogućava izbor optimalne konfiguracije oslanjanja. Ovako efikasan razvoj oslanjanja eliminira potrebu za skupim nadzorom strojnog sustava, tj. alatnog stroja i oslonca. U radu je dana analiza dinamike fleksibilno oslonjenog alatnog stroja u realnim uvjetima. Rezultati su dobiveni pomoću softvera SUPPORT. Konačno, teorijski i računarki rezultati potvrđeni su opsežnim mjerenjima na alatnom stroju, odgovarajućom mjernom opremo

Simulation of the casting process - a powerfull tool for enchanced design of the cutting teeth in surface mining

Recent development in the computer simulation technology caused a tremendous influence on a rapid prototyping in casting process. These computational tools facilitate engineering work and urge moulding verification in foundries. Among dedicated software packages the MAGMASoft is selected for availability reasons. Its effectiveness is proved with the simulation of moulding process of the cutting teeth for a bucket wheel excavator Use of MAGMASoft enables a shortcut to a forceful and durable product, without internal cavities and micro-porosity. Such advancement of the moulding process is described in this paper

Possibility of obtaining favorable mechanical properties of materials for machine elements exposed to wearing and abrasion

There are several options for increase resistance to abrasive wear of parts. Inserting the cocoon into the hole of machine part that is exposed to wearing, welding on worn parts, joining by explosion of different materials or obtaining the bi-nzetal and hardening of finished parts by explosion. The results of comparative studies of the properties of wear-resistant steels for the development of parts exposed to abrasion are presented in this paper. Experiment has included the analysis of the properties of explosion hardened steel 120Mn12, as well as the skills of bimetal (50Mn7 + S355). The results show that explosion processing in case of both variants of material lead to the improved resistance of the parts to abrasive wea