Arbetet är ett utvecklingsprojekt som inriktar sig på utveckling av ett nytt avstickskär till bearbetning av smådetaljer. Avstickskäret ska optimeras för användning inom längdsvarvar vilket gör att problem som bland annat överhäng och nedböjning sätts i fokus. Arbetet är utfört på WhizCut AB i Helsingborg med syftet att minska materialåtgången som uppstår vid avstick av diametrar som är mindre än 13 mm. Det ska göras genom att utveckla och konstruera ett stickstål som kan användas under samma förhållande som konventionella system men med en mindre skärbredd. Den mindre skärbredden gör att materialåtgången minskas vilket är en fördel för massproduktion alternativt produktioner med exklusiva material som bland annat titan och rostfritt stål. Metoder som används är femstegsmetoden för produktutveckling där brainstorming används for att få fram nya idéer och konkurrenternas lösningar på liknande problem undersöks. För att säkerställa produktens styrka och även jämföra med konventionellt system används balkteori och FE-analys med hjälp av Inventor Professional 2020. Resultatet är ett tvåskärigt skär med båda skäreggarna riktade mot arbetstycket, detta gör att överhänget för processen kan minskas med mer än 30% samtidigt som böjstyvheten för skäret ökar med mer än 50%. Ett minskat överhäng och ökad böjstyvhet gör att skäret kan användas i tuffare miljöer med högre skärhastighet och matning för ökad produktivitet eller ersätta konventionella system med ett smalare skär. Det smalare skäret minskar konsumenternas materialåtgång vilket leder till att både konsument och miljön vinner på detta koncept. / This project focuses on developing a new system for parting of small parts.The tool must be optimized for usage in a swiss type lathe which concludes that problems including overhang and bending of the cutting edge has a majorpart in this project. This project is carried out at WhizCut AB with the purpose to reduce material waste during parting off operations at maximum diameter 13 mm. This will be done by developing a parting off tool that can be used under the same conditions as conventional tools but with a reduced cuttingwidth. The reduced cutting width results in reduced material waste which is anadvantage mass production and production in exclusive materials such as titanium and stainless steels. Methods that are used during the project is a fivestep development process that includes brainstorming to generate new ideasand competitors solutions to similar problems is looked into. To ensure that thestrength of the product and also compare with the conventional system calculations for beam theory and FEA-analyses is used in Inventor Professional 2020. The result is a two-cutting edge insert with both edges located against the workpiece, this makes it possible to reduce the overhang with more than 30% and a the same time increase the stiffness of the insert with more than 50%. Due to reduction in overhang the insert can be used in more demandingenvironments with increased cutting data or replace conventional system witha more narrow tool without changing the cutting parameters. The more narrow tool reduces material waste which is profitable for both end user and theenvironment.

PURPOSE: To analyze surface roughness, the edge chipping of different CAD/CAM bur milled dental materials (bar and crown design of 1.0mm and 1.5mm thickness), correlate the effect of machining damage on the material strength, compare the flexural strength of bur milled versus sectioned CAD/CAM blocks and evaluate the tool wear after milling. MATERIALS AND METHODS: Five dental CAD/CAM materials were used: Lithium disilicate glass-ceramic (IPS e.max CAD), Leucite-reinforced glass-ceramic (IPS Empress CAD), Feldspathic porcelain (Vitablocs Mark II), Feldspar ceramic-polymer infiltrated (Enamic), and composite resin (Lava Ultimate). Ten rectangular bars with dimensions of 4 mm × 2 mm × 14 mm were milled using a new set of burs for each material. Then, ten crowns of each material with thicknesses of 1.0 mm and 1.5 mm were milled after scanning a standard aluminum die with corresponding marginal thickness. The bars surface roughness was measured. Then, three specimens were selected for the edge chipping analysis using (SEM). Thereafter, 3-point bend test was used to test the flexural strength of bur milled and saw cut bars with the same dimensions. For the crowns, load to failure test was used. One-way ANOVA and Tukey HSD post hoc tests to determine the difference between the groups using JMP13.0 with α=0.05. RESULTS AND CONCLUSIONS: The surface roughness and edge chipping was significantly affected by the material composition. Comparison of the flexural strength of bur milled to sectioned bars, IPS e.max CAD and IPS Empress CAD show statistically significant less flexural strength (p<0.001). A strong correlation was found between the decrease in flexural strength and the chipping length on the central tensile side of the bur milled materials (R2=0.62, p=0.01). Crown thickness significantly affects the edge chipping as 1.5 mm crown thickness has more edge chipping than 1.0 mm crowns. However, no correlation is found between the load to failure test for the crown design and the edge chipping for 1.5mm and 1.0 mm thickness crowns. Tool wear is significantly affected by the material type. / 2021-07-31

This diploma thesis focuses on the design of new technology for the production of a given part by company Poppe + Potthoff s.r.o. The thesis is divided into three parts. The first part is a theoretical analysis of individual operations that are necessary for the production of the given part. The second part deals with the analysis of the current technological process of production. In the third part, a new technological process is proposed. In the end, there is a technical and economic evaluation performed, where both variants are compared.

No description available.

Sustainable manufacturing is making products from processes which have minimal environmental impact, energy and resource efficient, economically viable and safe for consumers and society as whole. Achieving sustainability in manufacturing would mean infusing sustainability methods on product process and system level. On the process level, machining technology is one of the most widely extended processes in the industry. One way to attain sustainability in this technology is by adopting efficient management of Metal Working Fluids (MWF). In this purpose to reduce the amount of MWF starts Minimum Quantity Lubrication (MQL), where very small quantity of fluid is applied to the cutting zone with maximum precision. Moreover, addition of nanoparticles to these ´minimum quantity lubricants´ further enhances its tribological properties leading to higher reduction in friction and temperature in the machining process.The main objective of this thesis is to study the performance of cooling-lubricating fluids and these fluids modified with nanoparticles, how the use of this new lubricants improves the results obtained in material process technologies, particularly in turning. This project is being supported by the company LetsNano AB, providing the lubricants enhanced with nanoparticles and the funding, and Accu-Svenska AB, providing base oil and MQL technology.The experiments are carried out at Kungliga Tekniska Högskolan (KTH), at Institutionen för Industriell Produktion (IIP) laboratory. The turning process was tested with two different workipiece materials: hardened steel (Toolox® 44) provided by SSAB, and grey cast iron (Scania case study material). Two different tooling systems, due to the different materials. One provided by Mircona AB, and the other given directly by Scania, provided by Sandvik AB and Cermatec AB. The MQL system is a high-performance booster provided by Acuu-Svenska AB. The lubricant is a vegetable oil that will also be the base for the Nanofluids (NF). This Nanofluids and produced and developed by LetsNanoAB.The study revealed an encouraging potential of moving from conventional (dry) cooling techniques to the vegetable oil based MQL. Machining performance of MQL was encouraging as in most of the cases the systematic reduction in tool wear reveals a better machinability. The contribution of this work for Scania could help them to take the decision and move to more sustainable machining processes. To prove the potential of the nanotechnology in this kind of processes further study is needed, and it is going to be tested at IIP facilities in near future. The implementation of this technology brings more challenges that should considered a study of the hazards of the technology (emissions, fire and explosion, noise, skin…) necessary safety measures (cleaning, operator instruction, skin protection…) and modifications in the machine tools system beyond the process only. This could also be a next step in the further study of this research. / Hållbar tillverkning gör produkter från processer som har minimal miljöpåverkan, energi och resurseffektiv, ekonomiskt genomförbar och säker för konsumenterna och samhället som helhet. Att uppnå hållbarhet i tillverkningen skulle innebära infusion av hållbarhetsmetoder på produktprocess och systemnivå. På processnivå är bearbetningsteknologi en av de mest utbredda processerna inom branschen. Ett sätt att uppnå hållbarhet i denna teknik är genom att anta effektiv hantering av metallbearbetningsvätsko (MWF). I detta syfte för att minska mängden MWF startas Minimalsmörjning (MQL), där mycket liten mängd vätska appliceras på skärzonen med maximal precision. Dessutom ökar tillsatsen av nanopartiklar till dessa "minimala smörjmedel" ytterligare sina tribologiska egenskaper vilket leder till högre minskning av friktion och temperatur i bearbetningsprocessen.Huvudsyftet med denna avhandling är att studera prestanda av kylsmörjande vätskor och dessa vätskor modifierade med nanopartiklar, hur användningen av de här nya smörjmedlen förbättrar resultaten som erhållits i materialteknik, särskilt vid vridning. Projektet stöds av företaget LetsNano AB, vilket ger smörjmedlen förbättrad med nanopartiklar och finansieringen, och Accu-Svenska AB, som erbjuder basolja och MQL-teknik.Experimenten utförs vid Kungliga Tekniska Högskolan (KTH) vid Institutionen för Industriell Produktion (IIP). Vridprocessen testades med två olika material: Härdat stål (Toolox® 44) som SSAB levererade och grått gjutjärn (Scanias fallstudiematerial). Två olika verktygssystem, på grund av olika material. En som tillhandahålls av Mircona AB och den andra som ges direkt av Scania, tillhandahållen av Sandvik AB och Cermatec AB. MQL-systemet är en högpresterande booster som tillhandahålls av Acuu-Svenska AB. Smörjmedlet är en vegetabilisk olja som också kommer att vara basen för Nanofluiderna (NF). Dessa Nanofluider och produceras och utvecklas av LetsNanoAB.Studien avslöjade en uppmuntrande potential att flytta från konventionell (torr) kylningsteknik till den vegetabiliska oljebaserade MQL. Maskinens bearbetningsförmåga var uppmuntrande, eftersom i de flesta fallen den systematiska minskningen av verktygsslitaget visar bättre bearbetning. Arbetet med detta arbete för Scania kan hjälpa dem att fatta beslut och flytta till mer hållbara bearbetningsprocesser. För att bevisa nanoteknikens potential i denna typ av processer krävs ytterligare studier, och det kommer att bli testat vid IIP-anläggningar inom en snar framtid. Genomförandet av denna teknik ger fler utmaningar som bör övervägas en studie av farorna med tekniken (utsläpp, brand och explosion, buller, hud ...) nödvändiga säkerhetsåtgärder (rengöring, operatörsinstruktion, skydd mot huden ...) och modifikationer i verktygsmaskinerna system utöver processen bara. Detta kan också vara nästa steg i den fortsatta studien av denna forskning.

In this research, the integration of the servomechanism control and process control for machining processes has been studied. As enabling strategies for next generation quality control, process monitoring and open architecture machine tools will be implemented on production floor. This trend brings a new method to implement control algorithm in machining processes. Instead of using separate modules for servomechanism control and process control individually, the integrated controller is proposed in this research to simultaneously achieve goals in servomechanism level and the process level. This research is motivated by the benefits brought by the integration of servomechanism control and process control. Firstly, the integration simplifies the control system design. Secondly, the integration promotes the adoption of process control on production floor. Thirdly, the integration facilitates portability between machine tools. Finally, the integration provides convenience for both the servomechanism and process simulation in virtual machine tool environment. The servomechanism control proposed in this research is based on error space approach. This approach is suitable for motion control for complex contour. When implement the integration of servomechanism control and process control, two kinds of processes may be encountered. One is the process whose model parameters can be aggregated with the servomechanism states and the tool path does not need real time offset. The other is the process which does not have direct relationship with the servomechanism states and tool path may need to be modified real time during machining. The integration strategies applied in error space are proposed for each case. Different integration strategies would propagate the process control goal into the motion control scheme such that the integrated control can simultaneously achieve goals of both the servomechanism and the process levels. Integrated force-contour-position control in turning is used as one example in which the process parameters can be aggregated with the servomechanism states. In this case, the process level aims to minimize cutting force variation while the servomechanism level is to achieve zero contour error. Both force variation and contour error can be represented by the servomechanism states. Then, the integrated control design is formulated as a linear quadratic regulator (LQR) problem in error space. Force variation and contour error are treated as part of performance index to be minimized in the LQR problem. On the other hand, the controller designed by LQR in error space can guarantee the asymptotic tracking stability of the servomechanism for complex contour. Therefore, the integrated controller can implement the process control and the servomechanism control simultaneously. Cutter deflection compensation for helical end milling processes is used as one example in which the process cannot be directly associated with the servomechanism states. Cutter deflection compensation requires real-time tool path offset to reduce the surface error due to cutter deflection. Therefore, real time interpolation is required to provide reference trajectory for the servomechanism controller. With the real time information about surface error, the servomechanism controller can not only implement motion control for contour requirement, but also compensation for the dimensional error caused by cutter deflection. In other words, the real time interpolator along with the servomechanism controller can achieve the goals of both the servomechanism and process level. In this study, the cutter deflection in helical end milling processes is analyzed first to illustrate the indirect relationship between cutter deflection and surface accuracy. Cutter deflection is examined for three kinds of surfaces including straight surface, circular surface, and curved surface. The simulation-based deflection analysis will be used to emulate measurement from sensors and update the real-time interpolator to offset tool path. The controller designed through pole placement in error space can guarantee the robust tracking performance of the updated reference trajectory combining both contour and tool path offset required for deflection compensation. A variety of cutting conditions are simulated to demonstrate the compensation results. In summary, the process control is integrated with the servomechanism control through either direct servomechanism controller design without tool path modification or servomechanism control with real time interpolation responding to process variation. Therefore, the process control can be implemented as a module within machine tools. Such integration will enhance the penetration of process control on production floor to increase machining productivity and product quality.

No / This paper presents a Knowledge-Based (KB) integrated approach for planning and designing of number of machining centres, selection of material handling system, layout and networking architecture and cost analysis for a Flexible Manufacturing Systems (FMS). The KB model can be applied for integrating the decision issues at both the planning and designing stages of an FMS for three types of layouts (single row, double row, and loop) and three MHS types (robot-conveyor, AGV-conveyor and a hybrid AGV-robot-conveyor). The KB methodology starts from a suitable information input, which includes demand per year of part types, part type’s information, machining centre’s calculation, Material Handling System (MHS) selection, machining centre’s layout selection, networking selection and financial analysis. The KB methodology is developed by using AM, an expert system shell, and contains over 1500 KB rules. The performance of the system has been verified and validated through four published and four industrial case studies, respectively. The validation results from industry show that the KB methodology is capable of considering detailed design inputs and is able to assist in designing and selecting a practical FMS. It is concluded that a KB system for the present FMS application is a viable and efficient methodology.

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No description available.

No description available.