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Freudenberg Sealing Technologies has developed a new concept for the manufacture of diaphragm accumulators. Its advantages are a reduced need for components, fewer process steps, shorter assembly times, a higher level of product cleanliness, and an expansion of the product portfolio into additional fields of application. These diaphragm accumulators also weigh significantly less. This is opening up new opportunities for applications in the automotive and industrial fields. The assembly concept is based on a hermetically sealed pressure chamber in which the joining of the two housing halves with the help electromagnetic pulse technology (EMPT) as well as the filling of the gas side with nitrogen takes place in a single operation. In this way, downstream filling to generate the initial gas charge is no longer necessary.

Ces travaux proposent une méthode d’assistance à la sélection des techniques d’assemblage et à l’allocation de tolérances sur les écarts géométriques des composants dans le cadre de l’assemblage de structures aéronautiques composites. Cette méthode consiste à formuler et à résoudre un problème d’optimisation multiobjectif afin de minimiser un indicateur de cout et un indicateur de non-conformité des structures assemblées. L’indicateur de coût proposé prend en compte le coût associé à l’allocation des tolérances géométriques ainsi que le coût associé aux opérations d’assemblage. Les indicateurs de non-conformités proposés sont évalués à partir des probabilités de non-respect des exigences géométriques sur les structures assemblées. Ces probabilités sont évaluées en propageant les tolérances géométriques allouées et les dispersions des techniques sélectionnées au travers d’une fonction appelée Relation de Comportement de l’assemblage (RdCa). Dans le cas de l’assemblage de structures aéronautiques composites, des exigences peuvent porter sur les jeux aux interfaces entre composants. Dans ce cas, la RdCa est évaluée par la résolution d’un problème mécanique quasi-statique non-linéaire par la méthode des éléments finis. Un méta-modèle de la RdCa est construit afin de la rendre compatible avec les méthodes probabilistes utilisées pour évaluer la non-conformité. Finalement, la définition d’un modèle structuro-fonctionnel du produit et d’une bibliothèque de techniques d’assemblage permet de construire un avant-projet de gamme d’assemblage paramétrique. Ce paramétrage permet de formuler le problème d’optimisation multiobjectif résolu à l’aide d’un algorithme génétique. / The purpose of this PhD is to develop a method to assist assembly technique selection and component geometrical tolerance allocation in the context of composite aeronautical structure assembly. The proposed method consists in formulating and solving a multiobjective optimisation problem aiming at minimising a cost indicator and a non-conformity indicator. The cost indicator account for both the cost involved by the geometrical tolerance allocation and the cost associated with the assembly operations. The proposed non-conformity indicators are evaluated according to the probabilities of non-satisfied requirements on the assembled structures. These probabilities are computed thanks to Geometrical Variation Propagation Relation (GVPR) that expresses the characteristics of the product as a function of the geometrical deviation of the components and the dispersion occurring during the assembly. In the case of composite aeronautical structures, the product characteristics can be gaps at interfaces between components. In this case, the GVPR is evaluated by solving a non-linear quasi-static mechanical problem by the mean of the finite element method. A metamodel of the GVPR is built in order to reduce the computing time and to make it compatible with the probabilistic methods used to evaluate the non-conformity. Finally, the use of a structure-functional model of the product together with an assembly technique library allows defining a parametric assembly process plan. The multiobjective optimisation problem built thanks to set of parameters defining the assembly process plan is solved using a genetic algorithm.

Scania verkar på en global marknad med tillverkning på flera orter och en förutsättning för att kunna garantera kvalité på de produkter som levereras, oavsett vart de produceras, är ett konsekvent tillämpat standardiserat arbetssätt vid tillverkning och montering. Monteringsbeskrivningar - eller elementblad som de benämns på Scania är en viktig del i att kommunicera detta "standardiserade arbetssätt" över hela företaget och alla desstillverkningsenheter. Det s.k. standardiserade arbetssättet är relativt väl utvecklat mellan de verkstäder som monterar samma typ av huvudkomponenter, men i ett vidare perspektiv så förekommer det mellan olika enheter såväl skillnader i presentation av data i elementblad som arbetsmetoder för att ta fram dem. Det finns därför ett uttalat behov av att standardisera såväl framtagning som presentation av data i elementblad. Syftet med detta examensarbete har varit att utveckla och testa en effektiv arbetsprocess för att tidsätta och ta fram lättförståeliga elementblad med stöd av digitala underlag. Därmed har en koppling mellan processerna för digital provmontering och framtagning av elementblad skapats. Ett förslag till arbetsmodell för framtagning av elementblad för chassimonteringen presenteras. I denna används de digitala underlagen både vid tidssättning med hjälp av standardtidssystem och för framtagning av bilder för beskrivning av monteringsoperationerna. Arbetsmodellen är anpassad till de applikationer som Scania använder idag. Resultatet av den enkät där arbetsprocessens effektivitet utvärderats visar att den har potential att leverera elementblad av högre kvalité än dagens process. / Scania operates in a global market and has manufacturing at multiple sites worldwide. Independently of where they are made, a consistently applied standardized work is a fundamental necessity to ensure the quality of their products. Assembly instructions – or element sheets as they are called at Scania, play an important role in communicating this standardized work across the entire company. The so called standardized work is relatively well established amongst production units which assembles the same type of key component, but in a wider perspective there are differences in presentation of the data in element sheets as well as the work methods used to create them. This evokes the need to standardize the creation process as well as how the data of the element sheets are presented. The purpose of this study has been to develop and test an efficient work process where digital models are used for creating element sheets with a high level of comprehensibility, and in addition for conducing predetermined motion time study (PMTS) of the activities included in them. Thus, a link between digital test assembly (DTA) and the process for creating element sheets has been established. A proposal for a work process for the creation of element sheets for the chassis assembly is presented. In this, the use of digital models while conducting PMTS as well as when extracting illustrations for describing assembly operations are fundamental. The work process is adapted to fit Scania’s existing software portfolio. The result of the survey where the work process efficiency was evaluated showed that it has the potential to deliver element sheets with a higher quality than the process of today.

The thesis is concerning rotator assembly at Indexator. A need to increase production has been seen and it can be done by implementing an optimized assembly process. In addition to the assembly process a new design on workstations and new test equipment is needed.The study resulted into three assembly process proposals. The processes were balanced, layouts were produced and Plant simulation was utilized to produce simulation models. Each proposal were analyzed based on cost, performance, ease of implementation, flexibility and worker condition. This resulted in a stationary assembly process being most promising and a 3D simulation model was produced for visualization and better understanding. The stationary assembly process has a capacity for 90 rotators per day, while reducing the amount of workers by one.The layout of the workstations was done based on the assembly process layout and further developed to make the work cell lean and ergonomic. It resulted in three workstations to perform the assembly. The test bench was developed by creating target specifications, establish a test procedure and decide components for the test bench layout. The finished test bench can measure dynamic torque, count particles to ensure cleanliness and is able to run the test unattended. / Examensarbetet handlar om montering av rotatorer på Indexator. Målet är att ta fram en optimerad monteringsprocess som kan implementeras i Indexators fabrik utan svårigheter. Den nya monteringsprocessen kommer kräva en ny design på arbetsstationerna och nya testbänkar.Fyra koncept på monteringsprocessen togs fram, baserat på monteringens behov och målsättning. Efter utvärdering så modifierades de fyra koncepten till tre förslag på monteringsprocesser. Processerna balancerades, layouter utvecklades och simuleringsmodeller producerades för varje process. Varje förslag analyserades baserat på kostnad, prestanda, implementation,flexibilitet och arbetar-förhållande. Resultatet blev en stationär monteringsprocess och en 3Dsimulering gjordes för visualisering och förståelse. Den stationära monteringsprocessen har en kapacitet på 90 rotatorer per dag och reducerar behovet av montörer.Layouten för monteringsstationerna baseras på processens layout och har modifierats för ergonomiska aspekter. Inom monteringsstationerna så utvecklades layouten för att minimera antalet onödiga rörelser för montören. Testriggens design utvecklades genom att analysera de behov som fanns, skapa en kravspecifikation samt utvärdera och besluta om testprocedur, upplägg för testrigg och dess ingående komponenter. Testriggen uppfyller målsättningen som är att kunna mäta dynamiskt vridmoment, räkna partiklar för att säkerställa renhet i rotatorn och kunna utföra testningen självgående för att frigöra montören under testprogrammet.

Este trabalho teve como objetivo propor uma metodologia para otimizar o planejamento de processos de montagem final da indústria automotiva. A metodologia proposta foi elaborada com base na revisão bibliográfica e no Mapeamento de Processos Críticos da atividade de planejamento de processos de montagem final durante o desenvolvimento de produtos, tendo como referência a subsidiária brasileira de uma montadora. A metodologia proposta consiste em aplicar o PFMEA (Process Failure Mode and Effect Analysis) associado às seguintes ferramentas de qualidade: Brainstorming, Benchmarking, Lições Aprendidas, Sistemas À Prova de Erros, Diagramas de Causa e Efeito e 5 Por Quês. Neste trabalho foi adotada a realização de uma pesquisa explicativa com metodologia de pesquisa-ação. Foram criados procedimentos para que a metodologia proposta fosse aplicada experimentalmente na unidade de análise deste trabalho. A fase de coleta de dados foi feita através de três estudos de caso. Com base nos resultados obtidos, foram analisados os benefícios da aplicação da metodologia proposta e os procedimentos para formar equipes para realizar estudos de PFMEA, no contexto da Engenharia Simultânea. Foi observado que a aplicação da metodologia proposta por este trabalho proporcionou importantes benefícios para o planejamento de processos de montagem final, a especificação técnica de equipamentos de montagem e o desenvolvimento de produtos. / The objective of this work was to propose a methodology to optimize the general assembly process planning of automotive industry. The proposed methodology was elaborated based on bibliographic revision and a Critical Process Mapping regarding general assembly process planning activity during product development, referring to a Brazilian automaker subsidiary. The proposed methodology consists in applying PFMEA (Process Failure Mode and Effect Analysis) associated with the following quality tools: Brainstorming, Benchmarking, Lessons Learned, Error Proof Systems, Cause and Effect Diagrams, and 5 Why’s. Explicative research with action research method was adopted in this work. Procedures were created to experimentally apply the proposed methodology to the analysis unit of this work. The data collect phase was performed through three case studies. Based on the experimental results, advantages of the proposed methodology and PFMEA team formation were analyzed, in the context of Simultaneous Engineering. It was observed that the implementation of the proposed methodology provided important benefits to general assembly process planning, assembly equipment technical specification and product development.

In an attempt to reduce costs and improve customer satisfaction, manufacturers have been adopting strategies such as Delayed Product Differentiation (DPD) while managing broader product lines. In this study, first a general framework on DPD is formed in the light of basic articles in the literature. The vanilla box assembly process which is a special form of modular design type of DPD is modeled and analyzed. In the vanilla box assembly process, inventory is stored in a special form of semi-finished products, called vanilla boxes, that can serve more than one final product. We model the vanilla box assembly process considering the costs of inventory and unsatisfied demand under the capacity limitations, stochastic demand and bill of material requirements. We formulate the model as an extensive form of stochastic integer program in which stochastic demand is modeled using a set of demand scenarios each of which is assigned a probability of occurrence. The model is solved as a standard integer programming model that minimizes the expected value of the objective function. The impact of product demand scenarios, common component levels, shortage penalty cost to holding cost ratio levels and capacity restrictions on the total cost and fill rates is studied. We compare the performance of vanilla box assembly process to assemble-to-order process and provide insights on their performances. Computational results indicate that the vanilla box assembly process is a promising alternative to the assemble-to-order process in most of the problem instances.

Este trabalho teve como objetivo propor uma metodologia para otimizar o planejamento de processos de montagem final da indústria automotiva. A metodologia proposta foi elaborada com base na revisão bibliográfica e no Mapeamento de Processos Críticos da atividade de planejamento de processos de montagem final durante o desenvolvimento de produtos, tendo como referência a subsidiária brasileira de uma montadora. A metodologia proposta consiste em aplicar o PFMEA (Process Failure Mode and Effect Analysis) associado às seguintes ferramentas de qualidade: Brainstorming, Benchmarking, Lições Aprendidas, Sistemas À Prova de Erros, Diagramas de Causa e Efeito e 5 Por Quês. Neste trabalho foi adotada a realização de uma pesquisa explicativa com metodologia de pesquisa-ação. Foram criados procedimentos para que a metodologia proposta fosse aplicada experimentalmente na unidade de análise deste trabalho. A fase de coleta de dados foi feita através de três estudos de caso. Com base nos resultados obtidos, foram analisados os benefícios da aplicação da metodologia proposta e os procedimentos para formar equipes para realizar estudos de PFMEA, no contexto da Engenharia Simultânea. Foi observado que a aplicação da metodologia proposta por este trabalho proporcionou importantes benefícios para o planejamento de processos de montagem final, a especificação técnica de equipamentos de montagem e o desenvolvimento de produtos. / The objective of this work was to propose a methodology to optimize the general assembly process planning of automotive industry. The proposed methodology was elaborated based on bibliographic revision and a Critical Process Mapping regarding general assembly process planning activity during product development, referring to a Brazilian automaker subsidiary. The proposed methodology consists in applying PFMEA (Process Failure Mode and Effect Analysis) associated with the following quality tools: Brainstorming, Benchmarking, Lessons Learned, Error Proof Systems, Cause and Effect Diagrams, and 5 Why’s. Explicative research with action research method was adopted in this work. Procedures were created to experimentally apply the proposed methodology to the analysis unit of this work. The data collect phase was performed through three case studies. Based on the experimental results, advantages of the proposed methodology and PFMEA team formation were analyzed, in the context of Simultaneous Engineering. It was observed that the implementation of the proposed methodology provided important benefits to general assembly process planning, assembly equipment technical specification and product development.

This thesis addresses the problem of achieving better convergence between different phases (here design and manufacturing) of the product development cycle. The use of liaison has been proposed to better integrate the product and assembly process. Two facets of integration have been addressed in this thesis. One is concurrent evolution of the process model with the product model and the second is associativity between product model and process model. A liaison data structure has been proposed, which is set of geometric entities, associated with one or more assembly process that acts as an interface between the product model and process model. As the liaison data is not available explicitly in the product model, a set of algorithms have been developed and implemented to identify and extract the geometric entities defined in the liaison data structure from assembly model. The proposed algorithms can identify and extract liaisons for riveting, welding, bolt fastening, screw fastening, adhesive bonding (gluing) and blind fastening. The developed algorithms have been implemented and tested. The process model needs to evolve with the product model concurrently so that any mistakes or infeasibility in the process model can be flagged right away. The use of liaison enables the construction of process model as the product model is fleshed out. A framework based on liaison has been proposed and implemented to demonstrate the concurrent evolution of product and process model. Linking the changes in the product model to flag the changes (or at least identify the need for changes) in the process model forms the associativity problem. The liaison has been used for maintaining associativity between the product and process model. A framework has been proposed for maintaining associativity between product model and process model that makes use of expert knowledge or tribal knowledge to track impact of changes in product model or process model. An aircraft wing box has been used as an example to illustrate and validate the proposed approaches. Finally the thesis concludes by summarizing contributions of the research and outlining future work.

The aim of this diploma thesis is processing of the design of the assembly line for assembling of water ventilation systems of thermoregulation of an engine. The proposal is comprised of determination of the line cycle time, required number of workers and a creation of three possible options of assembly line solution. The final variant will be chosen by using a multi-criterion evaluation.