Industrija je pod sve većim pritiskom financijske krize, globalne
konkurencije, strožih zakona o zaštiti okoliša, lanaca ponude i potražnje.
Da rješavajući ova pitanja, održivi trend razvoja mora ...osigurati sinergiju
na svim razinama / poljima, uključujući i obrade. Ovaj rad promovira
održivu proizvodnju putem suvremene tehnologije u vidu alternativnog
kriogenog procesa obrade. Prikazani su eksperimentalni rezultati
komparativne kriogene obrade u odnosu na konvencionalne procese,
kroz analizu: sila rezanja, trošenja alata, temperature i troškove. Ovaj rad
dokazuje da kriogene tehnologije imaju visok potencijal za smanjenje
troškova i poboljšanje konkurentnosti smanjenjem potrošnje resursa, dakle,
omogućuje manje otpada, a ima manji ekološki i društveni utjecaj. Rezultati
ovog rada potvrđuju da alternativna održiva kriogena obrada omogućava
ispunjenje uvjeta za održivost: ekonomsku, socijalnu i ekološku, u odnosu
na konvencionalnu obradu.
Ovaj se članak bavi reorganizacijom slobodnih površina i ocjenom kompleksnosti modela slobodnih površina, grupirajući određena površinska geometrijska svojstva unutar zatvorenih površina, koristeći ...samoorganizirajuću Kohonenovu neuronsku mrežu (SOKN). Neuronske mreže pokazale su se kao prikladan alat za razmatranje svih topoloških nelinearnosti koje se pojavljuju kod slobodnih površina. Vrijednosti koordinata oblaka točaka raspodijeljenih nad određenom površinom korišteni su kao svojstveni opis, što je nadalje vodilo prema SOKN-u, gdje su ustanovljeni reprezentativni neuroni za zakrivljenost, nagib i prostorno-površinska svojstva. Na temelju ovoga pristupa reorganizirane su granice zatvorenih površina na takav način da metode površinske obrade daju najbolje moguće rezultate spram površinske hrapavosti. Granice tih površina određene su prema Gaussovoj i prosječnoj zakrivljenosti kako bi se postigao glatki prijelaz između zatvorenih površina te kako bi se na taj način očuvala ili čak unaprijedila željena zakrivljenost i glatkoća površine, (C2 i G2). Pokazano je da se reorganizacijom granica s obzirom na zakrivljenost, nagib i prostornu raspodjelu točaka, poboljšava kvaliteta obrađene slobodne površine. Pristup je eksperimentalno potvrđen na 22 modela slobodne površine koji su reorganizirani SOKN-om i površinski obrađeni određenim metodama. Rezultati pokazuju poprilično dobro poboljšanje prosječne vrijednosti površinske hrapavosti Ra za reorganizirane strukture u usporedbi sa neorganiziranim slobodnim površinama.
Cilj je ovog rada dati prikaz smjernica u ostvarenju održive proizvodnje stvaranjem kriogenih uvjeta radi postizanja viših perfomansi u obradi, manjeg utjecaja na okolinu i ljude, povećanja ...sigurnosti itd. Istraživanjem se prikazuju pojedinosti o kriogenim fluidima i njihovoj upotrebi u postupcima strojne obrade kao alternativno sredstvo emulzijama na bazi ulja. U radu su dane pojedinosti o tekućem dušiku i načinima njegove primjene u strojnoj obradi, poznatim kao kriogeni procesi strojne obrade. Istraživanje je provedeno eksperimentalno pri obradi legura za rad na visokim temeperama na bazi volframa i na taj način dan značajan znanstveni doprinos u postupcima održive proizvodnje. Eksperimentalni i analitički rezultati potvrđuju da kriogena tehnologija strojne obrade ima dobar potencijal za smanjenje troškova i poboljšanje konkurentnosti, smanjenje potrošnje sirovina, smanjenje otpada, manji utjecaj na okolinu i ljude, ispunjavajući uvjete održivosti: ekonomske, socijalne i okoliš u odnosu na konvencionalne postupke strojne obrade.
The purpose of the study was to establish the most important influencing parameters concerning innovation processes aimed at achieving improved business performance in the machinery and equipment ...manufacturing industry in Slovenia. A five steps research methodology was applied. Initially, a group of variables among the statistical data was selected, and then some additional variables were defined. In the third step, the variables were dispersed among the following categories: input, process, indirect output and direct output variables. In the fourth step, reciprocal correlations among particular variables were calculated prior to the final selection of the most important correlations and their interpretation. The influential input and process variables were estimated, and these indicate not only the sequence of activities but also particular areas where additional effort needs to be invested in innovation. The research limitations are related to statistical methodology since the used correlation coefficient itself does not provide any information on the direction of the cause-effect relation. Further limitations are connected with statistical data failing to cover all the important topics related to the innovation performance within a company. There are also some misleading questions/definitions in the SURS/Eurostat which partially result in subjective results. The time delay factor also represents one of the limitations of the study. Namely, a change in certain influencing parameters (e.g. R&D expenditure) normally requires a certain period of time to actually come into effect. The findings also represent a set of suggested guidelines in which enterprises, national policy leaders and also supporting environment organisations should put their efforts. The way of analysing and interpreting the data deriving from the mechanical industry are new. Besides, the results and conclusion are also original and may be applied by the aforementioned target groups.
The purpose of the study was to establish the most important influencing parameters concerning innovation processes aimed at achieving improved business performance in the machinery and equipment ...manufacturing industry in Slovenia.
A five steps research methodology was applied. Initially, a group of variables among the statistical data was selected, and then some additional variables were defined. In the third step, the variables were dispersed among the following categories: input, process, indirect output and direct output variables. In the fourth step, reciprocal correlations among particular variables were calculated prior to the final selection of the most important correlations and their interpretation.
The influential input and process variables were estimated, and these indicate not only the sequence of activities but also particular areas where additional effort needs to be invested in innovation.
The research limitations are related to statistical methodology since the used correlation coefficient itself does not provide any information on the direction of the cause-effect relation. Further limitations are connected with statistical data failing to cover all the important topics related to the innovation performance within a company. There are also some misleading questions/definitions in the SURS/Eurostat which partially result in subjective results. The time delay factor also represents one of the limitations of the study. Namely, a change in certain influencing parameters (e.g. R&D expenditure) normally requires a certain period of time to actually come into effect.
The findings also represent a set of suggested guidelines in which enterprises, national policy leaders and also supporting environment organisations should put their efforts.
The way of analysing and interpreting the data deriving from the mechanical industry are new. Besides, the results and conclusion are also original and may be applied by the aforementioned target groups.
The tool-wear of cutting tools has a very strong impact on the product quality as well as efficiency of the machining processes. Despite the nowadays high automation level in machining industry, tool ...-wear diagnostic that is measured of the machine tool, still prevent complete automation of the entire machining process. Therefore, its in line characterization is crucial. Thus the paper presents developed innovative, robust and reliable direct measuring procedure for measuring spatial cutting tool-wear in-line, with the usage of laser profile sensor. The technique provides possibility for determination of 3D wear profiles, as advantage to currently used 2D subjective techniques (microscopes, etc.). The use of proposed measurement system removes the subjective manual inspection and minimizes the time used for wear easurement. In the manuscript the system is experimentally tested on a case s tudy, with further in-depth performed analyses of spatial cutting tool-wear.
This paper describes a possible method for predicting values of orthogonal metal cutting properties such as shear angle, cutting force etc., on a basis of the well known Hollomon equation, using a ...simple compression test in order to avoid any cutting experiments. There are two possibilities: the flow stress properties can be obtained from an independent material test; or by measuring the active and passive cutting forces from the orthogonal machining test itself. This paper is concerned with a material flow stress equation, including the effects of strain (
ϵ), strain rate (
ϵ
̇
) and temperature (
T), which is one of the five equations that have to be solved in simulation analysis with the finite element method. In finding a solution for those five equations, it is necessary to dispose of flow stress properties by rearrangement of the Hollomon equation and so making it usable for cutting process investigation. The rearrangement is described in this paper.
Sustainable 3D mould design and manufacturing Kopac, J.; Balic, J.; Cus, F.
PICMET '08 - 2008 Portland International Conference on Management of Engineering & Technology,
2008-July
Conference Proceeding
Development and implementation of scientific tools and principles for designing and manufacturing of sustainable products such as 3D moulds for glass bottles blowing are very important. 3D modelling ...will be described on the cases of glass products. The mass production industry of glass blowing will be described. CAD and CAM programme will be used for technical documentation-drawings and also for cutting technology planning in moulds machining. CAM (Computer Aided Manufacturing) programme for mould machining will be prepared for application on 3-axial milling CNC machine tool. Specialities as drilling of long bores (vacuum bores) will be explained. Dry and near dry cutting will be included in machining processes as elements of sustainable manufacturing. When all machining operations are done, moulds are checked (dimensions, surface quality, fitting on other tool parts) and when the production of the bottles start, each manufactured product is thoroughly examined.
PDF
