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  • 1.
    Al Khatib, Bayan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Vakuumlyftverktyg för Rullborrkroneben2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sandvik Mining and Rock Technology (SMRT) manufactures various roller-cone bits that are used for rock drilling. The roller-cone bit consists of three welded cones. The cones are forged and delivered from an external supplier. The roller-cone bit’s cones are collected in an EU-table then lifted into a milling machine for processing. After the milling, the roller-cone bit’s cone is lifted again to a pattern table. Today, the method used today to lift the roller cone bit’s cones is not considered optimal for the operators. To improve the ergonomics of the operators, a vacuum lifting tool has been developed. The purpose of the work is to improve ergonomics through the lifting process of roller-cone bit cones. The goal is to develop a safer lifting tool. The lifting tool must be ergonomic and easy to use. To achieve the goal, previous research was examined on risk assessments of the working positions and standard SS-EN 13155:2009 followed. The Ovako Working Posture Analyzing System (OWAS) method was used to determine which working positions are considered most stressful for operators and needed to be addressed. The result from OWAS showed that the most stressful working position is the lifting of the roller-cone bit from the EU table. The concept, that was developed, consists of a suction pin connected to a vacuum pump with a T-piece. A pressure sensor is also connected to the t-piece to control the vacuum bar for the lifting tool. With the help of a non-return valve, the maintenance of the vacuum is ensured in case of power failure. After using the lifting tool, there will be no need to lift the roller-cone bit to load and unload the lifting strap. This means that the work positions with a high risk for load damage are going to be minimized.

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  • 2.
    Asgodom, Aaron
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Effektivisering av materialflöde i mellanlagerför stångstål2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Damasteel manufactures damascus steel using a process of powder metallurgy steelmanufacturing, which is done through a gas atomization process. Due to the growthof Damasteel's business, the company has purchased a new premises next to its production facility. The intention with new premises is that it will become the new intermediate warehouse and replace the current one. Therefore, it has been rebuiltand is now equipped with a larger storage space and handling equipment. In the current intermediate warehouse, there are problems with item placement, due to thembeing placed without regard to the frequency of their consumption. There is also anissue with various items sometimes being misplaced which leads to workers pickingthe wrong material for a certain order. This can only be detected after processingthe material.The purpose of this thesis is to investigate how the new intermediate warehouse canenable more efficient material handling, material flow and traceability. The objective of this thesis is to develop and conduct item placement based on frequencyplacement and consumption. A labelling system will be implemented for efficientbatch identification, traceability and short-bit sorting. To achieve the objective andpurpose of this thesis, a literature review was conducted on material flow, workingmethods in manufacturing companies and ABC-classification. With the help of theinformation produced from the literature review, an observation was able to be conducted. Which was then followed by a current situation analysis of the workingmethods within the current intermediate warehouse and the new intermediatewarehouse. Through the method of double ABC-classification, the higher ranked articles that should be paid attention, could be sorted. In accordance with the classification, a short-term improvement proposal could be produced. It consists of strategic article placement and labelling on the bars and cantilever racks to allow efficientmaterial flow and less stress for the workers. Long-term improvement proposalsconsist of long goods paternoster that would entail efficient storage space utilizationand then can be supplemented with a roll rack if it is considered necessary.Item classification was carried out with consumption and withdrawal frequency datafrom the year 2021, only because previous years data could not be obtained. TheABC-analysis results can be different if data consisting of several years is used. Withthe help of item classification, the size of safety stock and the tied-up capital can bereduced, which can enable better inventory space utilization. The current situationanalysis can be insufficient since the executor lacks previous experience in inventorymanagement. The item placement can be evaluated in later stages when data consisting of several year’s usage can be obtained. Lifetime cost of paternoster in relationto the needs and revenue of the enterprise should be investigated. 

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  • 3.
    Bergqvist, Fredrik
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Frölander, Jonathan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Utveckling av prototyp för slipning av ändlösa stålband2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    IPCO AB is a company in Sandviken whose specializing in preparation of steel belts. For instance, welding, grinding, and straightening. In present time, the grinding machine they are using is operating with grinding paper and a high concentrated emulsion, in which causes a lot of grease in the working area. IPCO AB, from now mentioned as the company needs a prototype of a new grinding machine which fulfills the customers requirements on surface roughness. In addition, the company also wants the machine to have improvements in economy and environmental aspects. The purpose of this thesis paper is to find development options in steel grinding, and the goal is to develop an analytic prototype. 

    To meet the requirements from the company, research was made in steel grinding both with internal sources and external sources. The development of a new prototype was possible due tothe expanded area of knowledge and the guidelines from the Swedish machinery directive.

    To progress with the project, a method diagram was made simultaneous with a Gantt-schedule. In addition, a Pugh’s-matrix and a risk analysis were made to determine the best components for the machine and to compare the risks in contrast to the present machine.

    The outcome of this project is an analytic prototype in Autodesk inventor, in which follows the guidelines of the Swedish machine directive. The developed prototype is in respect to the initial purpose and goal, in which takes economy, environment and efficiency in consideration. Consider the initial conditions, the new grinding stone is equivalent to three grinding papers.

    A constant flow of the coolant liquid improves the environmental aspects since no carcinogenicparticles occur. The parameters used in this paper is based on theoretical facts had has not been tested experimentally. These parameters are liquid flow-rate, the grinding pressure and rpm. To resecure these result, an experimental study needs to be done.

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  • 4.
    Clark, Eric
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering.
    Olsson, David
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Utveckling av arbetsprocess för effektivare produktutveckling: Tillämpad på standardisering av helautomatiskt snabbfäste till hjullastare2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In order to be competitive in the market, companies are forced to develop new strategies that can be adapted to ever-increasing customer requirements. The purpose of the work was to streamline product development for companies in the manufacturing industry. The objective was to develop an efficient work process for product development and apply the process to a project where a standardized fully automatic quick coupler for smaller wheel loaders would be developed for the company OilQuick.The thesis was divided into two parts. The first part deals with the development of a work process based on existing research. The second part deals with the application of the work process. Data for the application was collected through market research, meetings with customers and Reverse Engineering. Customer requirements were ranked using the Best-worst method and translated into technical specifications using the method QFD (House of Quality).Three concepts were generated based on the resulting requirements from the QFD. According to the customer requirements, the quick coupler had to be compliant with at least four different wheel loader brands in the weight span from five to eight tons. This meant that all three concepts were based on modular design, both to facilitate modifications between the wheel loader brads and to minimize the number of details that needed to be modified. All three of the concept's attachment brackets had standardized dimensions that fitted all examined wheel loader models. To determine which concept that best met the customer requirements the Fuzzy TOPSIS method was used. The final concept was adjusted based on OilQuick's requirements before the finished result was presented.The results showed that the work process was efficient and reliable and that the developed concept proposal indicates that it is possible for the company to standardize the interface between wheel loaders and attachments. With modular design the quick coupler can be adapted to the wheel loader brands that were studied. To ensure that the quick coupler can be applied to a larger variety of wheel loaders, it is necessary to examine and take measurements of more wheel loader brands before further development.

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    Utveckling av arbetsprocess för effektivare produktutveckling
  • 5.
    Erikanders, Jens
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Olsson, Oskar
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Arbetsmetodik för konstruktion av stålkonstruktioner med hänsyn till miljö och ekonomi2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Summary

    Global warming is a commonly known problem based on the amount of greenhouse gas emissions; a change is therefore necessary for important ecosystems not to be disrupted. The steel industry sector accounts for the largest environmental impact of Swedish industry, which makes it one of the most important areas for improvements to be made [1]. To reduce the environmental impact, a method is required which also lowers the cost of the product.

    This study resulted in a methodology by using proven methods and comparing against a reference construction. The following methods that were used to satisfy the customer requirements and striving towards environmental and economic sustainability were: Topology optimization, modular construction, Design for Manufacture and Assembly, Lean Construction, Design for Environment was discussed.

    A situation analysis was preformed to create a basis for the implementation of the methods. Application of the methods was carried out by mapping the concepts in an environment-cost-diagram with the reference. The methods were evaluated by interpreting the diagram and Pughs matrix, the evaluation resulted in a methodology that was applied through a final concept.

    The work resulted in a methodology, which is presented in a shortend verision: (1) Clear customer requirements; (2) several concepts with the goal of reducing variation and simplifying; (3) evaluating the concept's possibilities for modularization; (4) over all best concepts is selected; (5) Stress Analysis on the selected concept to make adjustment on oversized parts; (6) apply DfMA advise, reduce the number of parts that require lifting equipment during assembly.

    The method was validated by creating a concept with the final methodology. The concept met the same requirements as the reference construction. Part of the reference construction has eariler been made concepts of, which led to ideas of the earlier made concepts were taken on to the final concept. This led to certain margin of error in the validation. If other reference constructions were available, validation could’ve be done differently.

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  • 6.
    Forsberg, Sara
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Framtagning av rutin och standard för riskbedömning av ny arbetsutrustning: Tillämpad på BillerudKorsnäs2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When new work equipment is installed a risk assessment must be implamented to avoid accidents and incidents. Currently, BillerudKorsnäs i Gävle, is not sure whether their risk assessments are performed correctly. By developing a routine and standard where AFS 2006:4, use of work equipment, is implemented, it will be easier to fullfill the requirements for new work equipment. The purpose of this thesis is to reduce occupational injuries and contribute to a sustainable industry with the goal to develop a standard for risk assessment and a routine for how risk management can be performed correctly. Then apply the new routine and standard at BillerudKorsnäs. To achive the purpose and goals, a literature study was carried out. It was based on previous research within the steps of the risk management process. An analysis of the current situation at BillerudKorsnäs was perfomed. The current situation analysis consisted of a questionnaire and document analysis. The methods provided the opportunity to compare and combine theory with practice in order to develop a routine and standard for risk assessment.The resulting rutine was divided into four parts. Checklist for the project managers, before the risk assessment, identification of the risks and conrols and follow-up. The risk identification includes a risk assessment standard. The FMEA method is used to undentify consequences, estimate risks and to find a solution. The routine and standard should facilitate the risk management process and make it clear what work that needs to be done and which risks needs to be adressed.To make the routine and standard user-friendly, they are developed in Word and Excel. Several companies have access to Microsoft Office packages and will therefore be able to use the routine and standard for risk assessment. Which makes it possible to easily implement AFS 2006:4 in the security work. By using the routine and standard in risk assessment of new work equipment, accidents are reduced. 

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  • 7.
    Gutå, Emil
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Rytkönen, Gustav
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Analys av hur spänningen i förspända skruvförband påverkas av belastningar2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is a thorough analysis of how the bolt pretension of a clamped mount changes underexternal loads. The analyzed mount is named 3611 in MAFI’s product catalog. The purpose of thisstudy was to ensure that the bolt pretension remains within acceptable values and thereby minimizingthe risk of unexpected failures. The goal was to perform a thorough investigation of how the loadsaffect the mount's bolt pretension.Two simulation models for the clamp bracket were created as the mounting can be done on differentstructures. The models represent two types of generally used structures, pipe and steel angle bar. Thesimulations were performed in a computer program called Ansys where the models were created to beas close to reality as possible. The loads were divided into three different scenarios, sideways,gravitational and combined load. For the combined load scenario the models were exposed to bothsideways and gravitational load at the same time. The purpose of the simulations was to see how thebolt pretension changes when exposed to loads in different directions. Lastly, experiments wereperformed in order to confirm the results from the simulations.Results from the simulation and experiments differentiated less than ten percent except for oneexperiment. With a variation below ten percent, this means that the results are most likely credible. Byanalyzing the results from the simulations and experiments it can be concluded that the bolt pretensionwill increase in one bolted connection and decrease in the other when the mount is exposed tosideways and combined load. Based on the results of the work, it is concluded that there is a risk of abreakdown because the pretension clearly increases and that the wind load is dynamic in reality.Further tests should be performed in order to investigate the risk of fatigue-related breakdowns whendynamic loads are present.

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  • 8.
    Holmqvist, Tobias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Tesfamariam, Simon Kidane
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Konceptframtagning av lyftverktyg för byte av stödrullar i varmbandhaspel2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the hot-rolling mill VVV04 in Sandvik, there is down coiler unit that rolls the hotrolled strip. The down coiler unit has four wrapper rolls, these rolls acts as a support by pressing the hot-rolled strip over a major central axis. These wrapper rolls need to be replaced about once a year due to wear and tear, each roll weighs approximately 380 kg. at present, the wrapper rolls are lifted with lifting straps and lever block chain hoist. A new lifting tool is needed due to the current method of replacing the wrapping roll is not considered sufficiently safe from the point of view of the working environment. A literature study was carried out to assess the requirement to be met for the lifting tool to obtain CE-marking. The literature study also investigated ergonomic methods for assessing working positions. Development of the concept was done with a simplified version of the method described by Karl T Ulrich and Steven Eppinger. The concept was divided into three parts; grip, movement and attachment. The concept was created using a combination of brain writing and brainstorming over several meetings. Concept selection was done using a selection matrix called Pugh’s Matrix. To gain an understanding of the risks mechanics face when replacing wrapper rolls, an asis analysis was conducted. The developed concept was checked with FEM analysis and with manual calculations and showed very good safety margins. The work positions that are evaluated in the literature study are not improved from OWAS point of view, but several of the work steps are eliminated and made more efficient, which leads to increased safety for the mechanics, the lifting tool introduces a new working position with a lower risk. This lifting tool improves the working environment of the mechanics by increasing safety when changing the wrapper rolls and reducing physical stresses on the mechanics. Further work is to assess which material is most suitable and what changes to the concept are needed to simplify the production of the components.                 

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  • 9.
    Jansson, Fredrik
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Kring, Gustav
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Framtagning av portabel mätutrustning för kontroll av brädtjocklek inom sågverksindustrin2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    USNR is a multinational company manufacturing saw equipment. Occasionally they need to visit their customers to calibrate, and control delivered equipment. By measuring the thickness of sawed boards and evaluating the data, the saw equipment can be calibrated properly. The measuring operator uses a vernier caliper to identify a board’s thickness along its length. It is not unusual that the measuring operator needs to bend, kneel, or lay down during this operation. Using a vernier caliper as a tool for thickness measuring requires skill and there is a risk for human errors. Measuring boards using this method results in non-ergonomic postures, wasted time and unreliable measuring data. The earlier mentioned problems suggest a customized measuring equipment suited for thickness measuring of boards.

    The purpose of this study is to simplify calibration and control of equipment in the lumber manufacturing industry. The goal is to design a measuring equipment which fulfil requirements and wishes. To accomplish this, a literature study about standardization, modularization and measuring methods was carried out. The process of designing the measuring equipment was completed by using methods for product development. Initially, aA problem clarification was done and through a current situation analysis, after which requirements and wishes were specified. Based on the literature study, a suitable measuring method was chosen for the measuring equipment. Three concepts were modeled in CAD, these were evaluated with the help of a decision matrix to select which concept to detail design. For the chosen concept, design solutions were created to meet the set requirements and wishes.

    The measuring equipment consists of a frame with laser sensors and four modules of retractable tables designed with standardized components. The frame is movable along the tables because of integrated roller guidance. The function of the measuring equipment is based on fixing a board on top of the tables upon which the frame is sliding and registering the thickness along the length of the board. The measuring equipment is mobile and transportable.

    The use of standardized components gathered from CAD-databases enabled a rapid design process and a modular measuring equipment. To ensure all requirements and wishes are met, a prototype needs to be developed. With a prototype, the measuring equipment’s accuracy and stability can be verified under real conditions.

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  • 10.
    Lind, Elias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Västerbo, Erik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    En arbetsmodell för intervallplanerat underhåll: Planering och kostnadsberäkning för underhållsarbete2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna studie har genomförts hos en uppdragsgivare som verkar inom livsmedelsindustrin. Studien genomfördes då en av deras maskiner i produktionslinan har återkommande haverier. Maskinen är det sista steget i paketeringen och kallas för tejpnedtryckare. Den fäster en tejpremsa på förpackningarna för att försegla förpackningen under tillverkningsprocessen samt att konsumenterna kan återförsegla förpackningen vid användning. Maskinens oplanerade stopptid står för 2,4 procent av den totala produktionstiden och ett genomsnittligt avhjälpande underhållsarbete på tejpnedtryckaren tar två timmar. När studien genomfördes fanns det ingen tydlig plan för hur förebyggande underhåll på maskinen skulle utföras för att minska de haverier som inträffar. Syftet med denna studie är att minska den stopptid som uppstår på grund av haverier vid tejpnedtryckaren och målet med denna studie är därför att presentera en arbetsmodell för planering och kostnadsberäkningar av underhållsarbete.

    För att uppfylla studiens mål och syfte användes olika metoder. Det första som gjordes var att samla in data med hjälp av observationer, intervjuer och uppdragsgivarens databas. Utifrån datainsamlingen skapades det sedan ett Ishikawadiagram som visade vilka felkällor det finns till haverierna. Efter det utfördes en parvis jämförelse mellan felkällorna för att rangordna felen i hur allvarlig konsekvensen av ett haveri är. För att validera rangordningen av felkällorna gjordes en FMEA vid sidan av Ishikawadiagrammet. Efter felkällorna rangordnats beräknades dessa i en Weibullmodell för att få ut ett intervall för förebyggande underhåll. För att se underhållsarbetet ur ett ekonomiskt perspektiv utfördes beräkningar för att se vilken typ av underhållsarbete som ska utföras.

    Metoderna sammanfattades till en arbetsmodell som kan användas för att utreda och implementera underhåll på utrustning som saknar tillståndsbaserad övervakning. Arbetsmodellen består av en instruktion för hur modellen ska användas och kalkylark för kostnads- och intervallberäkningar. Stegen i modellen är genomförda i denna studie för att säkerställa att det är genomförbart och att det går att applicera på en maskin utan tillståndsbaserad övervakning.

    Felkällornas haveridatum var tvetydiga då underhållsrapporterna från uppdragsgivaren var mycket bristfälliga och svåra att tyda. Det var inte alltid möjligt att utläsa hur eller vad underhållet var utfört på. Detta medför att trovärdigheten för Ishikawadiagrammets, FMEA:ns och intervallberäkningarnas resultat är låg. FMEA, Ishikawadiagrammet och parvis jämförelse ingår inte i den slutgiltiga arbetsmodellen då de var överflödiga. 

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  • 11.
    Lindström, Emil
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Omkonstruktion av skrotkap till Sandvik ånggeneratorrör2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sandvik's production of steam generator pipes, products occasionally arise that do not meet the standard for Sandvik's requirements. This leads to possible risks in connection with manual cutting with an angle grinder and bundling of pipes that can lead to a collapse during transport. The purpose of the work is then to create a concept for a redesign of existing scrap shear from strip manufacturing, so that it can flatten and cut the steam generator pipes.

    As much as is reasonable of the machine must be preserved. Based on analyzes, the lever, attachments for hydraulic cylinders and engine, outlets from the machine and scraps were redesigned. As larger materials were to be processed, more power was needed in both rolling and cutting. Then essential parts need to be redesigned larger to provide space for newly purchased details.

    Increased power requirements, mainly for the redesigned lever, mean that more space is required for purchase components and stronger materials. The frame needs to be completely redesigned. Some purchase components such as bearing housings and the entire construction for the shears can be reused, but it is recommended to design a new machine for the larger forces and use larger roll diameters.

    Further future work that is recommended is to contact the company Hiak for production of sound covers as the machine's sound level is above the approved level, and to perform new assessments of the machine due to CE requirements for redesign and new production of machines, and a cost estimate for the redesign any cost.  

  • 12.
    Lundberg, Sven-Erik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Capital estimation for rolling mill projects2020In: Der Kalibreur, ISSN 0022-796X, no 80, p. 5-15Article in journal (Refereed)
  • 13.
    Lundberg, Sven-Erik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    The Making, Shaping and Treating of Steel: Long Products Volume2017Collection (editor) (Other academic)
    Abstract [en]

    This book provides a detailed description of what long products are, how they are classified, how they are produced, as well as the types of equipment that produce long products. The volume provides a comprehensive overview of long product production from describing the roll pass design, to the different shapes and sections, to the manufacturing of wire and wire products, to tubular products, and finally to high-alloy steel semi-finished products by casting and ingots.

  • 14.
    Löfbom, Thomas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Produktionskapacitetsökning i slipkapanläggning: Beräkning av effektbehov vid slipkapning2020Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Koproma engineering AB is a technology company that designs turnkey plants in the foremost steel industry. Part of Koproma's product range includes cutting machines, mainly abrasive cut-off machines. These machines are used to cut super duplex stainless steel materials. The machine owner of one of these cutting machines intends to cut larger materials than the current plants capacity.

    The purpose of this work is to investigate the power requirement when cutting duplex stainless steel materials with an abrasive cutting disc. The result should be used to redesign the current cutting plant, in order to meet the demand for the increase in production capacity. The purpose is also to see how the redesign affects resource utilization, efficiency, and plant utilization.

    By analyzing the process data for the current plant, the necessary data were established to validate the mathematical models, which were identified in a literature study on abrasive cutting. Product development methods such as morphological matrix and evaluation matrix VDI 2225 were used for concept generation and concept evaluation, respectively. This resulted in two definitive concept proposals.

    The desired increase in production capacity requires a nominal power of about 225 kW. By using super-thin cutting discs, the material removal rate is kept down, which also leads to reduced cutting power. The proposed electric motor has a rated power of 200 kW, which during instantaneous overload can withstand the power peaks the cutting process requires. This provides a design that is better utilized regarding engine power, without reducing accessibility or plant efficiency.

    Rotating the workpiece during cutting increases the effective cutting diameter of the disc. This means that number of cuts per disc increase by about 45 percent, which increases the lifespan of the disc. This means that the cutting machine increases its utilization of available resources. Based on the expected consumption of cutting discs, as well as the increased lifespan, an annual cost savings of over one and a half million SEK can be made.

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  • 15.
    Märs, Robert
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Kranse, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Utveckling av hjälpmedel för bränsledränering till helikoptermodell Airbus H145 D22020Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The helicopter model Airbus H145 D2 requires a daily inspection of the fuel. The inspection means that a small amount of fuel is drained and inspected from the drainage points located under the helicopter. This is currently done by crawling in under the helicopter, which isn’t ergonomic and may involve some risks.

    The purpose of this paper is to improve the working environment for the inspector with the goal of developing a functional prototype of a tool. To achieve this, previous research is used on risk assessment of work postures and the use and development of prototypes in a development process. Prototypes was manufactured, tested and evaluated to ease the design process. Risk analyzes using the risk assessment method Ovako Working Posture Analysis System, OWAS, was performed both with and without the tool.

    The developed prototype tool consists of a frame that can be pushed under the helicopter. On the frame is a pillar lift with a platform that can be raised and lowered using a combination of a lever and a clamping handle. The existing drainage tool is placed on the platform and thus the drainage valves can be opened and the fuel drained out. With the tool, the inspector no longer needs to crawl in under the helicopter. Work positions with an increased risk have been reduced from about 90 to 20 percent.

    The prototypes shows the advantages of using rapid prototyping methods early in the development and to risk analyze ideas already in the development process.

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  • 16.
    Norell, Adam
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Hajo, Darav
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Jämförelse av torr bearbetning och minimalsmörjningseffekter på fräsning av austenitiskt rostfritt stål2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Milling and other intermittent metal cutting operations often cause thermal fatigue in the cutting tools used. This type of wear is more severe during machining of heat resistant alloys such as austenitic stainless steel because of more extreme temperature variations during the cutting procedure. This phenomenon is further accelerated by employing flood cooling. Milling of stainless steel is therefore usually performed dry. Dry cutting is, however, not without its share of problems, since high temperatures develop in the cutting zone which adversely affect tool life and to which extent the productivity can be increased via higher cutting speeds or feed rates. Parts that take longer to manufacture are not only bad for business economics, but also for the environment due to higher energy consumption.Minimum quantity lubrication is a method that uses minimal quantities of oil dispersed as aerosol toward the cutting edge. This lubricates the tool-workpiece interface which minimizes frictional heat. This way, the total heat during cutting can be reduced while also avoiding the extreme temperature variations associated with flood cooling. The purpose of this thesis is to study and compare the performance of dry cutting and minimum quantity lubrication during face milling of austenitic stainless steel, 1.4301.The tool wear rates of the cutting tools and surface quality of the machined workpiece were compared for the two cutting environments. Of particular interest was the question whether the material removal rate could be increased with the usage of minimum quantity lubrication without adversely impacting the tool life or workpiece surface quality.A full factorial design of experiments was created, and the comparison of dry machining and minimum quantity lubrication was done by face milling with PVDcoated carbide inserts. An optical stereo microscope was used for the analysis of rake and flank wear after roughly 3 minutes of cutting tool engagement. Surface roughness of machined part was measured with a measuring stylus, and the temperature of the workpiece was measured with embedded thermocouples.The results show that minimum quantity lubrication reduces the temperature in the cutting zone, which for stainless steel means that the cutting speed should be increased to avoid the formation of built-up edges. At the same time, the material removal rate is increased, and productivity is affected positively.

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  • 17.
    Olsson, Hannes
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Larsson, Martin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Utveckling och optimering av gripmekanism för självcentrerande stöddocka2021Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    Self-centering steady rest are used to increase stability as well as precision during metal turning. This becomes extra important when the cutting operation is present at a long distance from the workpiece holding device. Current steady rests have a limited gripping range which leads to various sizes in order to satisfy customer needs. By developing a steady rest with a larger gripping range, less sizes would be needed to satisfy these needs.

    The purpose of this work is to increase the gripping range of an existing steady rest and increase its competitiveness on the global market. The aim is to develop a steady rest with market-leading performance by using modern optimization techniques. A market analysis was conducted which led to the conclusion that a 15 percent increase of the current gripping range was needed to be market leading. The current design of the steady rest was optimized with three different optimization algorithms which led to a performance increase of about eight percent. In order to identify alternative designs to the self-centering mechanism, four concepts where developed. These concepts were based on ideas generated through a brainstorming session. One of the four concepts was selected using criterions specified by the project’s client for further optimization and development. The final concept consists of arms with two cam curves and a center piece with four cam followers. By positioning these cam followers for gripping small and large workpieces respectively, a larger gripping range is possible. Further development included a similar optimization as well as implementation and modelling in CAD. The final steady rest resulted in a 23 percent increase in gripping range with a slight increase in length and depth.

    Optimization has proven to be a useful tool for developing high-performance mechanical products. During the optimization, a better understanding for the product and the problem at hand could be made by studying which design variables limits the performance of the steady rest. The mathematical formulation and optimization of the product can however be time consuming and challenging for mechanical design engineers. The gripping range of the presented steady rest is big enough to replace several sizes which is profitable for the environment, the customer as well as the manufacturer. This leads to the insight that optimization can be a powerful tool to develop more sustainable mechanical products.

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  • 18.
    Oskarsdottir, Alex
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering. HIG.
    Produktutveckling av en medicinteknisk arbetstol2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I syfte att bidra till en högre sysselsättningsgrad och ökad livskvalitet hos individer med kroniska nervsmärtor i ben och rygg har en produktutveckling av en medicintekniskarbetsstol genomförts. Som referensobjekt användes en prototyp som kombinerar funktioner på ett sådant sätt att stolen bidrar till minskad kotkompressionoch minskat tryck över nerver i ben. Målet var att skapa en digital prototyp med realistisktutformade mekaniska system, materialval samt produktionsmetoder.

    En nulägesanalys på referensobjekt utfördes med analysmetoden rapid upper limbassessment som grund för den ergonomiska bedömningen. Produktkrav och marknadsbehov kartlagdes med en konkurrentanalys och sammanställdes i en qualityfunction deployment matris. Utifrån insamlad litteratur togs beslut om vilka funktioner som skulle ingå i prototypen. Stolen dimensionerades enligt antropometriska mått, en gren av ergonomin som kartlägger kroppens mått.

    Prototypen möter målen om att generera lägre kotkompression och minska smärta i ben då den försetts med funktioner som enligt evidens har den effekten. De mekaniska system som utvecklats är en gunga som kan användas synkront, alltså som möjliggör vinkling av ryggstöd och sits oberoende av varandra. Ett magstöd integrerades i armstödet och kan användas vid sittande eller med stolen som ståstödsstol. Ett vajerbasserat bromssystem och ett justerbart svankstöd konstruerades. Anpassning avstolens dimensioner kan utföras för cirka 95 procent av den svenska befolkningen.

    För konstruktionens bärande delar valdes medelkolhaltigt stål av typen ISO CS30. Produktionsmetod för dessa delar är avdunstningsmönstergjutning i sand och skärandebearbetning av halvfabrikat i kombination med svetsning. För övriga konstruktionsdelar valdes polypropen och produktionsmetoden varmformning för prototyp och förslagsvis formsprutning vid slutgiltig produktion. Stoppning görs i viskoselastisktskum och armstöd i polyuretangummi. Val baserades på hållfasthetsberäkningar,gällande standarder, hänsyn till miljö samt ekonomi.

    I förhållande till referensobjektet förbättrades placeringar av reglage ur ett ergonomiskt perspektiv. Säkerheten ökades i och med att bromssystemet förbättrats och funktionaliteten ökades genom att integrera magstödet och utveckla en synkrongunga. Som ett fortsatt arbete föreslås framtagning av ritningar och hållfasthetsanalyser på fler detaljer i syfte att sänka vikten på överdimensionerade delar. Fysisk konstruktion av en prototyp och testning av referensgrupp kan sedan bidra till insikter om produktens bärighet på marknaden.

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  • 19.
    Persson, George
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Process development for H13 tool steel powder in binder jet process2020Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Additive manufacturing brings versatility and new degree of freedom for part design and manufacturing possibilities. Binder jetting is powder bed printing technique that does not require direct energy transfer rather binding powder metal particles through mechanical entanglement by use of the organic binder. The polymer chains in the solution hardens when heated thus creating a green part. Green parts are sintered in high temperature to adhere metal powder particles together creating a solid body. Binder jetting still developing to its full potential in scalability and material portfolio. This thesis aims to contribute know how in process and material development of H13 tool steel in very fine particle size distributions from -16 µm to -10µm. Process parameters as well as sintering cycle developed specifically for H13 fine powders. With 52 samples printed, sintered in four different temperatures and analyzed material properties such as density and hardness to evaluate how particle size distributions affect printing process, densification and shrinkage in the sintering. Density of the green body has been evaluated through measurements of dimensions and weight, sintered density was analyzed by Archimedes method and light optical metallography. Trials for the processing and evaluation of the powders concluded that it is possible to use ultra-fine PSDs in binder jetting process with good results, this opens up opportunity for increased sustainability and profitability for powder manufacturing industry. Particle size distribution of -10 µm has outperformed the -16 µm in areas of relative density of the green body, sintered density and hardness. Although superior performance, the -10 µm requires higher ultrasonic intensity and lower spreading speed to achieve homogeneous powder bed. For the -16 µm powder it is worth noting that it is possible to bring up green density with further process development. Although materials presented high hardness in as printed state compared to that of PIM manufactured parts, achieved hardness is not satisfactory for the applications of the alloy and requires heat treatment corresponding to customer requirements.

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  • 20.
    Rosén, Ida
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Brink, Kristin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Arbetsprocess för hållbar utveckling av balkstrukturer i korrosiva miljöer2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When designing beam structures that will be exposed to corrosive environments, strategies for integrating sustainability aspects in the development phase are required. This is to reduce environmental impact and safety risks while considering costs. However, many of the existing tools for sustainable development require extensive expertise and resources, posing challenges for designers to work with sustainability. For beam structures subjected to corrosion, damage and impaired performance can occur, adding further difficulties to the integration of sustainability. Therefore, a clear approach is needed to make sustainable choices across all dimensions of sustainability related to corrosion in construction work, while maintaining the required strength. The purpose of this work is to develop a working process to easily and practically integrate sustainability into the development of beam structures in corrosive environments, focusing on material selection, manufacturing, and assembly, with the goal of applying and evaluating the developed working process in a case study.

    A literature review of existing methods and tools for sustainable development was conducted to assess their potential contribution to achieving the objectives of the work. Together with the theoretical framework, which included the methodology for corrosivity classification as well as selection of steel types and surface treatments, the literature review formed the basis for developing the working process. By simplifying and combining some of the studied tools, a working process was developed to integrate sustainability into the traditional product development process. The developed tools included a sustainability matrix along with an assessment matrix for pairwise comparison, to sustainably select appropriate materials for the specific corrosive environment, as well as a combined checklist for the sustainable design of beam structures linked to corrosion, safety and economics.

    The devised working process was applied in a case study, involving the development of a beam structure in a mining facility with a corrosive environment, to evaluate its effectiveness and usability. The resulting working process led to a beam structure made of painted carbon steel that met the established requirements for strength and design. The working process effectively provided an overview for material and surface treatment choices and their impact on sustainable aspects. However, there might be some uncertainty when assessing and comparing sustainability. A material with low environmental impact could simultaneously be too costly and lead to worse working conditions. The checklist developed and integrated into the workflow was a valuable tool to identify and address safety risks during assembly and manufacturing at an early stage of the development process.

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  • 21.
    Saber, Dastan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    von Thelemann, Filip
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Produktutveckling av demonstrationsmodell för Cibes A5000 hiss2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Cibes Lift AB sells personal lifts and currently uses full-scale elevators for demonstration, for example at fairs. Now they want to come up with a mini-elevator that will facilitate the work of demonstrating the Cibes A5000 and also demonstrate the installation of screen walls, which is not possible with the full-scale elevator since the risk of accidents are high and the installation is permanent by pop rivets. In order to facilitate the work, systematic methods were developed to get a clear picture of the course of action, starting with a zero-state analysis of the problem to later immerse ourself in the subject of miniature models using a literature study. Subsequently, interviews and all data from the work were compiled and reviewed with the quality house method to create measurable criteria that could facilitate the draft proposals and the design phase. A risk analysis was also made with regard to constructing a safe product. Once the concepts were completed, one of them was chosen by Cibes. Forthgoing the construction of the elevator was broken down into modules to allow the work to be easily distributed. The result of the work is a construction of a 1:3 scale miniture lift that is capable of demonstrating operation between two floors and display the inner workings of liftsystem propulsions system and installation of a screen wall. The strength of the construction is calculated for the possible impact of a person that the miniature model can be subjected to. And a risk analysis was conducted to facilitate the construction of a safe product. Something that the project would have benefited from is that the zero-state analysis of the design would have been done at an earlier stage to facilitate scheduling and predict any help that might have been needed or knowledge that could be learned before work commenced.

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  • 22.
    Sandahl, Pär
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Broman, Cornelia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Förbättringskoncept stålfront: Cibes A5000 plattformshiss2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Steel fronts is Cibes most sought after frame and door combination to the public market such as schools, malls etc. because of the robust construction. However, there are problems with manufacturing efficiency, handling, and corrosion. The problems that arise are significantly connected to the construction being delivered from a subcontractor as a complete welded sheet metal construction. In addition, they are not designed to be installed in corrosive environments.

    Through preliminary investigations how today's manufacturing takes place and what is desired in the construction a QFD was made. By weighting, the QFD presented the most important qualities which the work should fulfill. The most important quality was that the construction must be modular, followed by reduced variation and corrosion resistant alternatives.

    With the help of idea generation methods, different concepts were developed, which all but the most promising were to be eliminated. The final concept includes a modular frame where variations of modules is 39 to maintain the same amount as today´s construction with 146 frame variations. Three materials were also con-cluded for possible application in different environments. Two of the materials have a lower price than the material used today (DC01 and DX51+Z275), in addition, two of them have a higher corrosion resistance (DX51 + Z275 and SS-EN 1.4404). The strength of the concept was verified with strength analysis supplemented with FE analysis.

    The developed concept leads to more efficient manufacturing process in that fewer products need to be stored and handled. However, the material prices and the strength of the concept are appreciated to a certain extent and need to be further verified.

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  • 23. Svenningsson, Inga
    et al.
    Tatar, Kourosh
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Exploring the mechanics of adhesion in metal cutting2023In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 127, p. 3337-3356Article in journal (Refereed)
    Abstract [en]

    The deterioration of the cutting edge during machining influences production cost and productivity. The adhesion is one of the main wear mechanisms. This study delves into the adhesive mechanism in the context of turning, milling, and drilling, focusing on three different cutting materials: 34CrNiMo6, 1.437 stainless steel, and ductile iron. Building upon previous research on the adhesive process in turning, a dynamic model was developed to understand the mechanism further. The results showed that adhesion is a general phenomenon occurring in all tested work materials, but with varying intensity levels. Intermittent cuts did not greatly impact the adhesive mechanism, and cutting data, coolant, and chip breaking also showed little effect. However, the presence of graphite in ductile iron temporarily inhibited adhesion. The source of the adhesive sound was found to be the pivoting movement of the chip as it binds and rips off the cutting tool, leading to a frequency shift upon detachment. The adhesive wear was found to be a thermal mechanism, where chemical reactions between the SiO2 in the work material with the cutting tool caused thermal cracks and low-frequency fatigue.

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  • 24.
    Svenningsson, Inge
    et al.
    Driscg.
    Tatar, Kourosh
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    On the mechanism of three-body adhesive wear in turning2021In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 113, p. 3457-3472Article in journal (Refereed)
    Abstract [en]

    The paper reveals a hypothesis regarding the adhesive mechanism in metal cutting and its mechanical dynamics. One steel grade, 34CrNiMo 6, 285 HB, and one set of coatings on the cutting tool are reviewed. The adhesive mechanism is a transient vibration, including a feedback system limited by the plastic deformation in the chip. The vibration shows as a cluster of waves with stochastic duration in time. It starts up again after a stochastic lapse of silence. The cycle frequency is around 12.5 kHz and the internal excitation is twice that frequency, as the cutting speed and feed are 200 m/min and 0.2 mm, respectively. The adhesive frequency and amplitude are influenced by the cutting speed and the current wear status. The adhesion is monitored by the sound waves emanating from vibrations in the chip, the part still in the workpiece.

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  • 25.
    Tatar, Kourosh
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Sjöberg, Sören
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Andersson, Niklas
    Sandvik Coromant.
    Investigation of cutting conditions on tool life in shoulder milling of Ti6Al4V using PVD coated micro-grain carbide insert based on design of experiments2020In: Heliyon, E-ISSN 2405-8440, Vol. 6, no 6, article id e04217Article in journal (Refereed)
    Abstract [en]

    Tool life prediction is generally of great importance in all metal cutting processes, including milling titanium. In this paper, tool life testing was performed based on full factorial design. The cutting speed and width varied between 100 and 120 m/min, and 10 and 70 percent of tool diameter, respectively. All cutting tests were performed in Ti6Al4V under wet conditions using Physical Vapor Deposition (PVD) coated milling inserts. The wear limit was set to 0.2 mm. The data were analyzed using multiple regression analyses, where the method of least squares was applied. A mathematical tool life model was established. Roughly, for each one percent increase in cutting width, tool life decreases on average by one percent, and an increase in cutting speed by a percent leads to a decrease in tool life by four percent. The adequacy of the model was verified using analysis of variance at 95% confidence level. Tool life contour in cutting width and speed was generated from the model. The results can be used for selecting optimum cutting parameters for providing a desired tool life or maximum metal removal rates for a favored tool life.

  • 26.
    Tatar, Kourosh
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Svenningsson, Inge
    Effect of chamfer width and chamfer angle on tool wear in slot milling2022In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 120, p. 2923-2935Article in journal (Refereed)
    Abstract [en]

    The tool geometry is generally of great significance in metal cutting performance. The response surface method was used to optimize chamfer geometry to achieve reliable and minimum tool wear in slot milling. Models were developed for edge chipping, rake wear, and flank wear. The adequacy of the models was verified using analysis of variance at a 95% confidence level. Each response was optimized individually, and the multiple responses were optimized simultaneously using the desirability function approach. The Monte Carlo simulation method was applied to tolerance analysis. All milling tests were conducted at dry conditions; the chamfer width and the chamfer angle varied between 0.1 and 0.3 mm, and 10 and 30°, respectively. Optimal chamfer geometry for minimizing chipping and rake wear was small chamfer width and chamfer angle. The flank wear reached the minimum value for the tool with 0.18 mm chamfer width and 10° chamfer angle. The obtained composite model predicted good edge strength and minimum overall wear when the chamfer was 0.1 mm wide at a 10° angle. Thermal cracks were observed on the tools. They were small on the edges with the finest and least negative chamfer but were more significant on the more negative and greater chamfer. A great chamfer width and chamfer angle also resulted in insufficient chip evacuation. The results show how the edge geometry affects the tool’s reliability and wear and may help manufacturers minimize tool cost and downtime.

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  • 27.
    Teshome, Antonio
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Albin, Johansson
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Undersökning av spånkanalutgångens inverkan på spånevakuering för löstoppsborr2022Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Borrning har sedan länge varit en av de vanligast förekommande bearbetningsmetoder. Trots att det är en välkänd metod finns det kvarvarande utmaningar med processen. En av utmaningarna är spånevakueringen, förmågan att evakuera spån från borrhål under processens gång. Spånevakueringen är av stor vikt för att kunna uppnå en effektiv borrprocess och en god hålkvalité. En väl utformad borrkropp är en avgörande faktor för god spånevakuering. På uppdrag av Sandvik Coromant ska utgången på spånkanalen förbättras för en av Sandviks borrar med utbytbar spets. Endast sega och långspånande arbetsmaterial kommer undersökas i detta arbete.

     

    flertalet faktorer påverkar spånevakueringen. Däribland borrkroppsgeometri och skärvätska. Dessa två parametrar har påvisats vara avgörande för att spånevakueringen ska fungera på ett effektivt sätt. Det påvisas att en parabolisk spånkanalsgeometri medför en bättre spånevakuering än en konventionell spånkanal. Om skärvätsketillförseln är otillräcklig eller om ingen skärvätska används uppstår risker för spånstockning. När spånstockning uppstår löper borren risk för brott på grund av ökat vridmoment. Otillräcklig tillförsel av skärvätskan leder även till en ökad temperatur vid skärzonen vilket medför stora förslitningar av skäreggen.

     

    I rapporten presenteras en analys av spånevakueringsförmåga för olika utformningar på spånkanalsutgångar hos konkurrerande borrar. Åtta borrar med signifikant skillnad på spånkanalsutgången valdes att undersökas. Spånevakueringsförmågan undersöktes experimentellt genom filmning med höghastighetskamera under borrning till maximalt rekommenderat borrdjup. Materialet som användes vid testerna var S235JR. Filmerna analyserades för att etablera vilka typer av geometrier som evakuerade spånor bäst. De bäst presterande borrarna 3D-skannades för att agera som underlag för prototypframtagning. Genom att tillämpa varierande spånkanalsutgångar på annars identiska borrkroppar kan spånevakueringsförmågan isoleras till denna geometriändring. Prototypernas spånevakueringsförmåga utvärderades genom skärkraftsmätning och höghastighetsfilm. Arbetsmaterialen som användes för prototyptest var 316L och S235JR. Tre olika spånkanalsutgångar undersöktes.

     

    Analys av höghastighetsfilmningarna visar att en spånkanalsutgång som är riktad mot rotationsriktningen tangentiellt med borrkroppen erhåller en bättre spånevakueringsförmåga. Analysen visar även att en stor släppningsvinkel på spånsidan kan medföra en mer obehindrad spånevakuering. Prototypframtagningen resulterade i två borrar med spånkanalsutgångar som styr spånor främst tangentiellt vilka jämförs mot en borr med rak spånkanalsutgång. Resultatet från skärkraftsmätning stärker slutsatsen att en spånkanal som styr spån tangentiellt erhåller en bättre spånevakueringsförmåga.

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  • 28.
    Örn, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Linander, Fredric
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Mechanical Engineering.
    Konstruktion av testbänk för karaktärisering2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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