When a reach truck moves its load sideways a sway appears in the mast. The objective of this thesis is to reduce this sway and thereby improve the load cycle time. This was done theoretically by designing new bearings for the fork carriage. Improved friction characteristics, especially lowered static friction, contributes to a lowered sway. The product development process follows the methods presented by Ulrich & Eppinger in their book Product Design and Development. The project was initiated with data gathering and function analysis which created a development roadmap for the product. The concept generation that followed ended in a slew of concepts that were evaluated together with personnel at the company. The winning concepts were developed further to a point where their function could be simulated. These simulations showed flaws in the developed concepts which resulted in a new direction for the project. A new theoretical fork carriage was to be developed alongside with a test-method used to validate using rolling element bearings in a fork carriage application. The end result is a modified fork carriage that uses rolling element bearings for sideways movement. This design has theoretically better friction properties than the original sliding bearings. The tests that were developed to validate the new design could not be performed. / När en skjutstativtruck flyttar sin last i sidled på hög höjd uppstår svaj i stativet. Det här arbetet syftar till att sänka det svajet och där med förbättra lastcykeltiden. Detta gjordes teoretiskt genom att designa nya lagringar till gaffelvagnen. Förbättrade friktionsegenskaper, framförallt sänkt statisk friktion, bidrar till sänkt svaj. Produktutvecklingsprocessen i arbetet följer Ulrich & Eppingers metoder som beskrivs i boken Product Design and Development. Arbetet inleddes med datainsamling och funktionsanalyser som skapade en övergripande plan om vilka områden på produktensom kunde förändras. Konceptgenereringen som följde slutade i en mängd koncept som utvärderades tillsammans med personal på företaget. De vinnande koncepten detaljkonstruerades sedan så dess funktion kunde simuleras. Dessa simuleringar visade brister på det framtagna konceptet vilket resulterade i att arbetet fick två nya fokusområden. En del av uppgiften blev nu att utforma en testrigg som endast skulle utvärdera validiteten i att använda rullager som lagrande element i en gaffelvagn. Den andra delen av arbetet fokuserade på att designa en teoretisk gaffelvagn som kan använda rullager men behålla all funktionalitet. Slutresultatet blev en modifierad gaffelvagn som använder rullager för sidledsförflyttning. Denna lösning ger gaffelvagnen teoretiskt bättre friktionsegenskaper. De tester som tagits fram för att validera den nya konstruktionen kunde inte utföras.

Vehicles are generally viewed as having their major environmental impact in the use phase because of combustion emissions. New technology can significantly decrease use emissions. These advantages suggest a rise in alternative vehicle drivetrains, e.g. electrical motors as well as a decrease of fossil fuel engines. It is of importance to consider what impact this technical shift might have in a lifecycle perspective. New technology requires specialised materials which in turn have substantial impacts during raw material extraction, manufacturing, and end of life. This means that the utilised materials may affect the total life cycle impact of a product. The impact can shift to other life phases and additionally give rise to impacts other than the frequently used energy consumption and climate change. The aim of this thesis is to understand how system boundaries effect environmental impact assessment. Potential life cycle assessment issues are investigated through studies of vehicle environmental impacts in different lifecycle phases and varying system boundaries. These issues are approached through several tools: LCA, Environmentally Responsible Product Assessment (ERPA), and Material Hygiene (MH). Three publications are appended to this thesis. Publication A compares two different disposal scenarios for end of life vehicles in Sweden. Publication B compares complete life cycle impacts of two dissimilar drivetrains in similar vehicles. Publication C investigates potential benefits of a concept sea vessel by comparing it with cargo transport by trucks. To fairly compare vehicles, with different drivetrain technology, it is not advisable to apply assessment that is limited to studying the use phase. Neither is it reliable to limit impact inventory to only energy use and CO2 emissions. The consequences of a narrow system-boarder are difficult to keep track of. To avoid sub-optimising and minimise risk of unawareness of trade-offs life cycle perspective is essential.

The importance of conducting efficient product development is growing steadily as traditional market boundaries diminish and are replaced by global market conditions. Digital product development builds on the foundation that digital mock-ups replace physical mock-ups, and this has the potential for strongly improving the efficiency of the product development process. This is a rather drastic change compared to the conventional way of conducting product development, and it cannot be implemented overnight. It requires the extended enterprise to rely on geometry based product models. Business excellence is therefore partially synonymous with managing these models and making them available, and relevant, to different activities throughout the product development process. This thesis deals with the establishment of two key expressions, Geometry Management Process and Geometry Based Product Information. The objective is to improve the utilisation of Geometry Based Product Information by supporting the product development process with adequate methods, tools and processes for managing this type of information. This objective is partly realised by the elimination of rework in the downstream activities of traditional design departments. There are numerous influencing factors and the research approach has been to collect these factors into four separate but correlating domains. The consistency in the approach stems from the fact that all research work is conducted with a geometrical perspective on all types of activity, requirement and process. The methodology is elaborated through participation and surveys of real cases in ongoing projects and activities when developing heavy-duty trucks. / <p>Godkänd; 2001; 20070313 (ysko)</p>

This licentiate thesis considers modelling, simulation and experimental investigation of a rammer compactor machine. The purpose is to develop an efficient and verified method for simulation of rammer compactor machines that can be used in the product development process. The experience gained through this work is also intended to be useful for studying other types of dynamic compactor machines. Rammer compactor machines perform impact soil compaction, which is very efficient compared to static compaction. They are often used in places where a high degree of compaction is needed and the space for operation is limited. The complexity of this machine type makes design optimisation through traditional prototype testing impractical. This has pointed to the need for a theoretical model and simulation procedure for prediction of the dynamic behaviour of the machine. To be useful for optimisation as design parameters are changed during product development the theoretical model and simulation procedure must be verified. By concurrently working with theoretical modelling, simulations, experimental verifications, and optimisation an efficient analysis support for product development is achieved. This co-ordination works both ways in an iterative manner. Experimental investigations are used to verify theoretical models and simulations. Theoretical models and simulations are used to design good experiments. This Complete Approach concept makes better decisions possible earlier in the development process, resulting in decreased time-to-market and improved quality. In this thesis, the Complete Approach concept is applied on a rammer soil compactor machine. An introductory iteration is described. The good agreement between theoretical and experimental results indicates that the theoretical model and simulation procedure should be useful for introductory optimisation studies. Reasons for the discrepancy are discussed and suggestions for improvements of both the theoretical model and the experimental set-up in coming iterations are given. / Godkänd; 2001; 20070228 (ysko)

This thesis deals with material parameter estimation for non-linear material models, which is an extremely important part of a finite element analysis. The aim of this work is to both estimate parameters and to quantify the their accuracy. The latter enable a total assessment of how the accuracy at different stages in i.e. the life prediction process affects the final estimated life. Thereby it is also possible to estimate the cost and value of improvements in material data in the different stages of the calculation. The thesis comprises an introductory part and two appended papers. The first paper discusses the influence on parameters and estimated life dependent on the choice of cost-function in the optimisation process. In the second a method for stress integration with regard to transverse recovery is discussed. / Godkänd; 1999; 20070320 (ysko)

This work covers integrated computer-aided applications for design and analysis in particular different integrated design systems for thermal and structural simulations. Two different design systems have been integrated to improve efficiency in product development, i.e. reduced lead-time and higher quality of the product. In the design systems CFD are used as input to FEA and vice versa. The integrated design systems have been demonstrated in two different thermal-structural applications and been evaluated in industrial situations. / <p>Godkänd; 1999; 20070403 (ysko)</p>

Godkänd; 1996; 20080328 (ysko)

The transport industry needs to change. Since the start of industrialism, fossil emissions from vehicles and transport have increased exponentially. Emissions affect both humans, animals and nature. This need to be reduced to stop global warming.This report presents a solution for the transport industry that enables completely environmentally neutral transport and fuel – hydrogen and fuel cells.The project team has examined technical parts of the fuel cell industry to determine how to create such an efficient fuel cell system as possible. The goal of the project is to carry out sustainable integration of fuel cells in a vehicle product that uses batteries as primary energy storage. Today’s consumption and use of lithium-ion batteries will pose future challenges, the group therefore wants to develop a proactive product that results in an extended lifespan and creates benefits by combining two technologies. The report handles the entire development process from idea to finished product with a final part before a market introduction.This result has become a prototype vehicle that is ready for hydrogen operation. An implementation plan has also been developed for how to implement fuel cells and hydrogen in an existing or future electric vehicle. The result is thus a comprehensive solution for how to transition to fully sustainable transport.With a concrete result and sustainable development in focus, the project team has created a product that will show leadership and inspire the transport industry to change and transform towards hydrogen gas energy.

For economic and environmental benefits, sawmills can reduce their waste by sawing with thinner bandsaw blades. When altering the cutting tooth geometry, it is vital to monitor the sawing process in realistic wood conditions such as frozen (green), non-frozen (green) and dried. The fundamental way to monitor the sawing process is to analyse the cutting forces when single cutting teeth interact with the wood. The three cutting forces acting on a sawtooth are the main, normal, and lateral forces. The main force can be split into two: 1) cutting by the main edge and 2) cutting by the side edges (the side force). The objective of this thesis work was to examine the main, side and normal forces in different wood conditions while cutting with different tooth geometries. In sawing, it is desired for the main and side forces to be minimised, and the normal force should remain close to zero. Two abundant Scandinavian wood species were considered: Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in non-frozen, frozen and dried conditions. The heartwood and sapwood were tested separately for non-frozen and frozen wood. The altered tooth geometries were the cutting width, clearance, band thickness, and the radial and tangential clearance angles.The main force was approximately 75% lower for the narrowest cutting tooth of 1.6 mm compared to the reference 2.87 mm wide tooth used in the industry. Narrow cutting teeth could, however, result in faster tool wear and vibrations. The main force was higher in pine than spruce due to the higher density of pine. Frozen sapwood showed distinctly higher main forces. The radial and tangential clearance angles had a negligible effect on the main force. There was a slight reduction in the main force in frozen sapwood at high radial and tangential clearance angles of 6◦. In frozen sapwood, the normal force was highly negative and self-feeding was observed. The normal force was less negative for narrower cutting teeth and at high radial and tangential clearance angles of 6◦. The cutting width, clearance and radial and tangential clearance angles did not have a notable effect on the normal forces in the remaining wood conditions, and the forces remained close to zero. The elastic spring-back plays an important role in side cutting and can be as high as 4 mm. Frozen wood has less elastic spring-back and, therefore, less side cutting. The percentage of side cutting to the main force was between 55% - 75% for dried wood. Lower clearance and lower radial and tangential clearance angles resulted in more side cutting due to increased contact between the teeth and elastic spring-back.The results show that special consideration needs to be taken when sawing frozen sapwood in the winter. Furthermore, the side cutting force plays a larger role when the cutting width is reduced and in dried wood and needs to be studied in more detail to understand its impact on the cutting process better.v

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. / Cibes Lift AB säljer personhissar och använder sig i nuläget av fullskaliga hissar för demonstration vid exempelvis mässor. Nu vill de ta fram en miniatyrhiss som kan underlätta arbetet vid demonstration av Cibes A5000 och även klara av demonstration av installation av skärmväggar vilket inte nu är möjligt med den fullskaliga hissen då skaderisken är stor och installationen är permanent av skärmväggarna med poppnitsförband. För att underlätta arbetet togs systematiska metoder fram för att få en klar bild över arbetets gång vilket började med en nulägesanalys av problemet för att senare fördjupa sig i ämnet miniatyrmodeller med hjälp av en litteraturstudie. Sedan utfördes intervjuer och all data från arbetet sammanställdes och granskades med metoden kvalitetshuset för att skapa mätbara kriterier som kunde underlätta konceptförslagen och konstruktionsfasen även en riskanalys gjordes med hänsyn till att konstruera en säker produkt. När sedan koncepten var klara valdes ett av dem ut av Cibes för att sedan konstruktionen av hissen bröts ner i moduler för att arbetet skulle kunna enkelt fördelas. Resultatet av arbetet är en konstruktion av en miniatyrhiss i skala 1:3 som klarar av demonstration av drift mellan två våningar och visning av draganordningen samt installation av en skärmvägg. Konstruktionens hållfasthet är beräknad för möjlig personpåverkan som miniatyrmodellen kan utsättas för. Och en riskanalys genomfördes för att underlätta konstruktionen av en säker produkt. Något som arbetet skulle ha gynnats av är att den mer grundläggande nulägesanalysen av konstruktionen skulle lagts i ett tidigare skede i arbetet för att underlätta tidsplaneringen och förutspå eventuell hjälp som kunde tänkas behövas eller kunskap som skulle kunna läras in innan arbetet påbörjades.