The research objectives of this thesis are as follows: (1) Investigate the effects of carbon content, alloying, and heat treatment of steels on white layer formation, (2) Prove/disprove that the temperature for phase transformation in machining is the same as the nominal phase transformation temperature of the steel, (3) Quantify the contributions of thermal and mechanical effects to white layer generation in machining, (4) Develop a semi-empirical procedure for prediction of white layer formation that accounts for both thermal and mechanical effects. These research objectives are realized through experimental and modeling efforts on steels. Depth and hardness measurements of the white layers formed in steels show the importance of heat treatment and carbon content on white layer formation. Measurements of workpiece surface temperature and X-Ray Diffraction characterization of the machined surfaces show that phase transformation occurs below the nominal As temperature suggesting that mechanical effects play an important role in white layer formation. The maximum workpiece surface temperature, the effective stress, and plastic strain on the workpiece surface are measured and/or calculated and shown to affect the white layer depth and amount of retained austenite. A semi-empirical procedure is developed by correlating the maximum workpiece temperature and the unit thrust force increase with white layer formation.

The aim of this thesis is the analysis of the current state in the workplace EDM and suggestion of the automation workplace in tool making "KASKO forms" including techno-economic assessment of the current and suggested solutions on the selected product and quantification of payback period.

This thesis describes the design of methodology for measuring the accuracy of robot machining. It describes the theoretical properties and classification of commercially available methods for precision measurement. In the practical part, a test workpiece is manufactured and positions and toolpaths are measured by the Pontos system. The proposals are based on the MCAE Systems company's equipment.

I takt med att CNC-fräsmaskiner blivit mer tillgängliga för allmänheten, växerbehovet av billiga alternativ till marknadsledande mätprobar (TTP). Generiska sensorer med öppen hårdvara finns tillgängliga till låga priser, men det är okäntom en sensor för under 100 kr kan användas som komponent i en mätprob, där noggrannhetskravet kan vara i storleksordningen mikrometer. Detta skulle isåfallinnebära att det finns en möjlighet att tillverka mätprobar till tillgängligare priser än dagens marknadsledande probar. Denna studie avsåg att undersöka ifall dessa sensorer var lämpade för ändamålet. Därför bedömdes ett antal Arduinokompatibla sensorer utifrån deras prestanda och lämplighet som komponent i en automatisk mätprob för arbetsstyckeslokalisering i CNC-fräsmaskiner. Sensorerna och principerna som undersöktes var: mikrobrytare, induktiva sensorer, ultraljudssensorer, IR-sensorer och kontinuitetssensorer. Sensorerna testades i en fräsmaskin och deras spridning estimerades genom att beräkna standardavvikelsen hos mätdatan. Efter en litteratursökning och intervjuer med KTHs akademiker samt den tänkta målgruppen för mätproben Stockholm Makerspace, bekräftades kravbilden på sensorn. Där belystes vikten av det låga priset på slutprodukten samt ett krav på att osäkerheten ska vara runt 0.05 mm. Mikrobrytaren konstaterades vara den lämpligaste sensorn. Detta beror på dess låga pris, oberoendet av materialet på arbetsstycket och den höga repeterbarheten. Repeterbarheten beräknades vara 5 μm med en konfidensintervall på 95%. / Since CNC-milling machines have become more accessible to the public, so has the demand for economical alternatives to the market-leading product, Trigger Touch Probes (TTP). Generic sensors with open hardware are now obtainable for a low price, but it is unknown if a sensor with a cost of under 100 SEK can be used as a component in a measuring instrument. Especially where the required accuracy lies in microns. If that is the case, it would be possible to manufacture TTP at more accessible prices than the current standard. This study aimed to answer whether the low cost sensors were suitable for this application. A number of Arduino compatible sensors were therefore evaluated in terms of performance and suitability as a component in an automated measurement probe for workpiece localization in CNC-machines. The sensors/ principles that were evaluated were: micro switches, inductive sensors, ultrasound sensors, IR-sensors, and continuity sensors. The sensors were tested in a milling machine and their statistical dispersion (scattering) were estimated by calculating the standard deviation of the data. After a literature study and interviews with academia from KTH and the intended customer, Stockholm Makerspace, the requirements on the probe were decided. The importance of the low cost of the final product were brought to attention and the requirement of a variance around 0.05 mm. The micro switch was evaluated to be the most suitable sensor due to the low price, high repeatability, and the fact that it was independent of the workpiece’s material. The repeatability was measured to be 0.0052 mm with a confidence interval of 95%.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main objective of this work is the experimental investigation of the effect that the material of the toolholder has on the temperature at tool-chip interface and on the surface temperatures of the cutting tool and toolholder. The study was conducted in dry turning of gray iron with uncoated cemented carbide inserts, using the same cutting parameters. Five toolholders had been confectioned in materials having different thermal conductivity, these being: copper, brass, aluminum, stainless steel and titanium alloy. The toolholders are identical and have the constructive aspects obtained from a commercial toolholder for turning that material. The temperature at the tool-chip interface was measured using the toolworkpiece thermocouple method and the surface temperatures in the tools and the toolholders, by conventional type T thermocouples. The system was modified in order to develop an experimental procedure for the physical compensating of the secondary and parasites thermoelectric signals (emf). Also, modifications was carried out in a conventional tailstock for use in driving the emf signal between the workpiece and a stationary conductor, but without significantly altering the stiffness of the system. The tailstock was electric insulated and a mercury bearing was mounted inside it and their internal connections were turned in reference junctions at room temperature because on otherwise it could act as secondary junctions. The calibration of the tool-workpiece thermocouple was developed in the same experimental apparatus using the modifications implemented in this system. Besides the results obtained with the investigation of the effects of the toolholder material on the surface temperatures of the tool and the tool holder and on the tool-chip interface temperature, this research also presents contributions to the use and performance of the tool-workpiece thermocouple method. / O objetivo principal deste trabalho é a investigação experimental do efeito que o material do porta-ferramenta exerce sobre a temperatura na interface ferramenta/cavaco e sobre as temperaturas superficiais da ferramenta de corte e do próprio porta-ferramenta. O estudo foi desenvolvido com a operação de torneamento cilíndrico externo de ferro fundido cinzento, a seco, com insertos de metal duro, em parâmetros de corte fixos. Cinco portas-ferramentas foram confeccionados em materiais com condutividades térmicas diferentes, sendo esses: cobre, latão, alumínio, aço inoxidável e liga de titânio. Os portas-ferramentas são geometricamente idênticos e têm as características construtivas de um porta-ferramenta comercial próprio ao torneamento daquele material. Mediu-se a temperatura na interface ferramenta/cavaco usando o método do termopar ferramenta-peça e as temperaturas superficiais na ferramenta e nos suportes, por meio de termopares convencionais do tipo T. O sistema termopar ferramenta-peça foi modificado no sentido de se desenvolver um procedimento experimental para a compensação física de forças eletromotrizes secundárias e parasitas. Destaca-se a execução de modificações em uma contra ponta rotativa convencional para o seu uso na condução do sinal da força eletromotriz entre a peça e um condutor estacionário sem, contudo, alterar significativamente a sua rigidez na fixação da peça. Nessas modificações, aplicou-se uma isolação elétrica permanente, implantou-se um mancal de mercúrio no seu interior e promoveu-se mudanças nas suas conexões internas, que poderiam agir como junções secundárias, transformando-as em junções de referência à temperatura ambiente. A calibração do sistema termopar ferramenta-peça foi desenvolvida sobre o próprio aparato experimental usando as modificações implantadas nesse sistema. Os resultados obtidos no trabalho mostram que os materiais usados nos suportes influenciam nas temperaturas superficiais da ferramenta e do porta-ferramenta, porém, que tais materiais não tem efeito significativo sobre as temperaturas da interface ferramenta/cavaco. Além disso, o trabalho apresenta, também, contribuições ao uso e calibração do método do termopar ferramenta-peça. / Doutor em Engenharia Mecânica

Master’s thesis is dealing with safety of workpiece clamping device. In the first part we are describing possibilities of clamping workpiece on different machines, legislative conditions in EU and CR in engineering devices, and general demands that refer to harmonized standards for different types of clamping devices. The main target of the thesis are the lists of requirements for hydraulic three-jaw chucks and proposal of two chosen safety applications. The first safety application refers to safety of clamping workpiece in hydraulic chuck. The second safety application is aimed at clamping of workpiece with the help of strap clamps. There is a description of the procedure of calculation of safe tightening moment during assembly of the nut.

The aim of this work was to design the construction of transport equipment under industrial robot, pallet holder or other equipment. This manipulation device can be moved in one axis on a rigid guide. The device is designed for use in a linear manufacturing system for handling workpieces and tools. It is capable of operating two rows of machines when it is placed in the middle. The main function of this device is to extend the workspace to the carried devices. This type of construction can be used in combination with an industrial robot for other technological tasks such as welding or light machining. The main parts of this device include statically mounted beds that can be stacked behind each other to form optionally long conveyor paths and a positioning plate that moves along the path formed by these beds. An industrial robot, pallet holder or other device is attached to this positioning plate. In addition to the design itself, the thesis also includes a thorough research of the issue, further possibilities of solution in the form of concepts, verification of the structure by means of calculations and simulations and implementation of the solution into a specific production cell.

This diploma thesis deals with palletization of heavy workpieces that are used by multi-purpose machining centers. The final outcome introduces a suitable option for palletization heavy workpieces of multi-purpose machining centers. In the first part of the thesis is draft of machining centers with parameters which were chosen by exploration of market for selecting suitable solution. The second part of thesis is dealing with a detailed draft palletization made by parts of exploration of market then design palletization system and design pallet changer. The designed construction of pallet changer is dimensioned with help of analytical calculating methods and numerical simulations methods. Outcome palletization system allows automatic change of twenty tons workpieces including pallet between two storage places.

The diploma thesis deals with the usage of integrated machine vision by B&R, Smart Sensor, for metal rectangular-shaped workpiece recognition and position determinition. The description of the usage of machine vision in the industry is made, the solution concept is created and the program and the user visualisation implemented. The main outcome of this work is the VITemplate library which can be used in combination with the model-based Blob analysis implemented in Smart Sensor to control the robotic arm to successfully grab all the workpieces on the belt.

This master's thesis is focused on the technology fundamentals of machining for the use of the CNC lathe which was used for machining the required parts are made of stainless steel. In the introduction are mentioned the historical milestones related to machine tools. In the following chapter is analyzed machining process and related fact. A follow-up chapter contains the parameters common to a modern machine tool CNC machines. Followed by the practical part with the characteristics of the machined components. The next chapter includes a selection of CNC lathe for production. Continued by selecting the appropriate cutting tool and adjusting the machine for the given component. They were applied a total of three variants of production with the subsequent evaluation. In conclusion, it became established fact, for example, the advantages of the shape tools or the use of more spindles during the machining.