Waste reduction possibilities in a manufacturing process

In this paper the manufacturing process of a high load-bearing capacity gear is introduced. These gears are built into truck and bus transmission systems and are machined at a high level of accuracy. The process has particular importance not only because the accuracy has to be ensured but because the machining of precision components requires relatively complicated processes. Here the process was described and quantified for a given component. The focus was on one-piece flow of components and its effect on decreasing lead time. On the basis of the analysis it was shown that one-piece flow can significantly decrease the lead time but the time spent with material handling increases, which results in a load on the operator or the material handling equipment. Therefore, multi-variable optimization is needed. The available results can be used for improvement of manufacturing processes of other component groups manufactured by similar technology

Chip removal characteristics with constant chip cross-sectional area and different ap/fz ratios in face milling

A main development direction in production engineering is the of the enhancement productivity of machining procedures among the increasing of the accuracy and the improvement of surface quality. Since the sizes of blanks are getting closer to the final prescribed dimensions of the parts, the depth of cut and/or the number of passes decreases. Therefore, the improved productivity in face milling can be achieved by the increase of the cutting speed and/or the feed rate values. Due to the spread use of high speed milling procedures the possibilities in the cutting speed increase are more or less applied, so the study of feed rate intensification came into view

Comparative study of material removal in hard machining of bore holes

Kod tehnološkog planiranja postupaka u strojnoj obradi tvrdih površina potrebno je uzeti u obzir nekoliko čimbenika. Jedan je čimbenik sustav geometrijskih dimenzija elemenata. Mogući postupci za osiguranje potrebne točnosti i kvalitete površina i/ili njihova (ekonomska) učinkovitost mogu također biti pod utjecajem geometrijskih dimenzija. U radu se brzina skidanja materijala i obrade površine istražuju u odnosu na otvrdnute unutarnje cilindrične površine. Ti se parametri odnose na rad u jedinici vremena. Vrijednosti parametara se analiziraju kod različitih geometrijskih dimenzija provrta. Istraživanja se provode za postupke strojne obrade tvrdih površina s različitim umetcima kao i kombinacijom te obrade i postupka brušenja, a vrijednosti se daju uz konvencionalno (poprečno) brušenje kao osnove za usporedbu.In the technological planning of hard machining procedures, several factors of the component have to be considered. One factor is the system of geometrical dimensions of the components. The potential procedures capable of providing the required accuracy and quality specified to the surfaces, and/or their (economical) efficiency can also be influenced by the geometrical dimensions. Beyond the generally prevailing time study, in the present paper the material removal rate and the surface rate are investigated referring to hardened internal cylindrical surfaces. These parameters are referred to the unit operation time. The values of the parameters are analysed at different bore geometries. The investigations are performed for hard machining procedures with different inserts, as well as a combined hard machining and grinding procedure, and values are given with conventional (traverse) grinding as the basis of the comparison

Analysis of Tool Life Functions in Hard Turning

The relation between the technological parameters of cutting and the tool life is important information that has been described by several functions since the publication of the Taylor formula. Although the vc-T cutting speed-tool life curve has local extremes, the Taylor formula can describe correctly only its monotone decreasing phase, and this is typical also for the vc-T function proposed by different researchers. This paper describes the results of studies aimed at analysing the relationship proposed by Kundrák and applicable throughout the interval of the vc-T curve. It introduces cutting speed ranges, analyses their boundaries and explores the relationship between constants of the new vc-T formula and the exponent k of the Taylor formula valid for section III. These findings were verified by experiments executed on hardened steel type 100Cr6 (HRC 60 ± 2) by K10 type CBN tool

Investigating the impact of feed and cutting speed on cutting forces for the increase of surface removal rate in face milling

Face milling is used for the manufacturing of engineering surfaces. A significant part of the produced surfaces pertains to flat surfaces with high quality. Surface quality, in turn, is connected to the machining conditions used in the process. In this paper, the influence of feed and cutting speed on cutting forces is experimentally investigated, with a view to increase surface removal rate A w (mm²/min) of the process. The experimental results are treated with ANOVA, indicate a high influence of the feed on all components of the cutting force. With the analysis, optimum conditions may be obtained with the aim of lower cutting forces

Examination of 2D and 3D surface roughness parameters of face milled aluminium surfaces

Material removal with a rotating cutting tool has a series of special characteristics due to the movement relations. For face milling, looped cycloids occur, which also affects the roughness characteristics of the machined surface. This article analyses how the values of 2D and 3D roughness parameters change in symmetrical milling of flat surfaces of aluminium parts in planes parallel to the feed direction

Investigation of cutting force in face milling

The increase of cutting applied in finishing processes can be achieved first of all by increasing the cutting speed and feed. In face milling, if feed fz per tooth is increased and/or the shape of the chip cross section is changed, the load of the cutting edges changes and influences the cutting forces and the actual efficiency. In this paper, the cutting force arising in chip removal and changing under the influence of the increased feed is analysed

Effect of cutting data selection on productivity in face milling

Face milling as a cutting procedure is used for high productivity manufacturing of prismatic components. In the automotive industry, characterized by mass production, the enhancement of productivity is a primary goal for manufacturing companies. There is a wide range of methods for increasing productivity. This paper analyses how productivity can be increased by the mach ining time, material removal rate and surface rate by choosing the appropriate cutting data. Cutting experiments were carried out for machining prismatic components and the change in machining time was analysed. It was proved that within the performance limits of the WGMT (Workpiece – Gadget – Machine – Tool) system a significant amount of manufacturing time and therefore cost can be saved while the geometric accuracy and surface quality of the component remain as specified in the blueprint

Az abrazív vízsugaras vágás alkalmazhatósága forgácsoló megmunkálási műveletekre

Today the waterjet is unparalleled in many aspects of cutting and has changed the way many products are manufactured. The abrasive waterjet (AWJ) is capable of a variety of operations. Waterjet cutting is a cold cutting process that does not cause fracturing in the material. Almost any material can be machined by waterjet cutting. While it is often used for cutting larger objects into pieces, extension of its application to free form surfaces is also being investigated from a number of angles. This article discusses the machining of a rotating body using alternative AWJ operations. Due to the excellent properties of the abrasive water jet, this process has potential for use in cutting machining.Napjainkban a vízsugár páratlan a vágási eljárások számos vonatkozásában, és megváltoztatta sok termék gyártásának módját. Az abrazív vízsugár többféle műveletre is képes. A vízsugaras vágás legnagyobb előnye más eljárásokkal szemben, hogy ez egy hideg vágási eljárás, mely nem okoz roncsolódást az anyagban, és gyakorlatilag bármilyen anyag vágására alkalmas. Darabolásra elterjedt a használata. Sokirányú kutatás folyik alkalmazásának kiterjesztésére alakos felületek megmunkálására. A cikk az alternatív abrazív vízsugaras műveletek közül a forgástest megmunkálását tárgyalja részletesebben, hiszen az abrazív vízsugár kiváló tulajdonságai miatt esélyes, hogy ezt az eljárást forgácsoló megmunkálásként is alkalmazzák

Az abrazív vízsugaras vágás alkalmazhatósága forgácsoló megmunkálási műveletekre

Absztrakt: Napjainkban a vízsugár páratlan a vágási eljárások számos vonatkozásában, és megváltoztatta sok termék gyártásának módját. Az abrazív vízsugár többféle műveletre is képes. A vízsugaras vágás legnagyobb előnye más eljárásokkal szemben, hogy ez egy hideg vágási eljárás, mely nem okoz roncsolódást az anyagban, és gyakorlatilag bármilyen anyag vágására alkalmas. Darabolásra elterjedt a használata. Sokirányú kutatás folyik alkalmazásának kiterjesztésére alakos felületek megmunkálására. A cikk az alternatív abrazív vízsugaras műveletek közül a forgástest megmunkálását tárgyalja részletesebben, hiszen az abrazív vízsugár kiváló tulajdonságai miatt esélyes, hogy ezt az eljárást forgácsoló megmunkálásként is alkalmazzák. Abstract: Today the waterjet is unparalleled in many aspects of cutting and has changed the way many products are manufactured. The abrasive waterjet (AWJ) is capable of a variety of operations. Waterjet cutting is a cold cutting process that does not cause fracturing in the material. Almost any material can be machined by waterjet cutting. While it is often used for cutting larger objects into pieces, extension of its application to free form surfaces is also being investigated from a number of angles. This article discusses the machining of a rotating body using alternative AWJ operations. Due to the excellent properties of the abrasive water jet, this process has potential for use in cutting machining