| 1. |
- Anderberg, Cecilia, 1963-, et al.
(författare)
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Liner surface improvements for low friction piston ring packs
- 2014
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Ingår i: Surface Topography : Metrology and Properties. - Bristol : Institute of Physics (IOP). - 2051-672X. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- The development of engine components in the automotive industry is governed by several constraints such as environmental legislation and customer expectations. About a half of the frictional losses in an internal combustion engine come from the interactions between the piston assembly and cylinder liner surface. The tribological considerations in the contact between the piston ring and cylinder liner have attracted much attention over the past few decades. Many non-conventional cylinder liner finishes have been, and are being, developed with the aim to reduce friction losses and oil consumption, but the effects of the surface finish on piston ring pack performance is not well understood. One way of reducing friction in the cylinder system is to reduce the tangential load from the piston ring pack, focusing on the oil control ring. However, the side-effect of this is a disappointingly increased oil consumption. In this study a number of different cylinder liner surface specifications were developed and implemented in test engines with the aim of maintaining the level for oil consumption when decreasing the tangential load for the piston ring pack. To improve our understanding of the result, the same surfaces were evaluated in elastic and elasto-plastic rough contact and hydrodynamic flow simulation models. It is shown that oil consumption is strongly related to surface texture on the cylinder liners and at lower speeds (900–1200 rpm), a 'rougher surface' with a high core (e.g. Sk) and valley roughness (e.g. Svk) results in higher oil consumption. At the medium speed range (1200–3600 rpm), oil consumption continues to dominate for the 'rough' surfaces but with a visible influence of a lower oil consumption for a decreased roughness within the 'rough' surface group. 'Smooth' surfaces with a 'smooth' core (Sk), irrespective of the valley component (Svk), show similar oil consumption. For engine speeds above 3600 rpms, an increase in plateau roughness results in higher oil consumption. Throughout the study, standard roughness parameters were computed to compare with the results from engine testing and simulation. Future work will be directed to continuous optimization between oil consumption and friction. Improving the understanding of the functional cylinder system surfaces' ability to form oil films in the cylinder system opens up opportunities, not only in reducing the tangential load of piston ring packs but also in optimizing oil viscosity in order to reduce friction.
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| 2. |
- Anderberg, Cecilia, et al.
(författare)
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Low friction and emission cylinder liner surfaces and the influence of surface topography and scale
- 2019
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Ingår i: Tribology International. - Kidlington : Pergamon Press. - 0301-679X .- 1879-2464. ; 133, s. 224-229
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Tidskriftsartikel (refereegranskat)abstract
- A low friction piston ring pack, with tangential load halved, was tested in engines with four different cylinder liner finishes. Oil consumption, oil temperature and liner surface temperature were monitored at different load and speed levels, under similar test conditions. The two smoother surfaces generally kept lower oil consumption compared to the two rougher ones. Results were correlated using an area-fractal analysis. The relative area of the surface was calculated at different scales and the result was compared with the level of oil consumption for the different liner surfaces at different engine speeds. It was found that oil consumption was strongly correlated with scale for areas of above 1000 μm2 and below 20 μm2. © 2018
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| 3. |
- Anderberg, Cecilia, et al.
(författare)
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Wear Resistance of Smooth Automotive Cylinder Liner Surfaces
- 2005
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Ingår i: World Tribology Congress III, Volume 2. - New York, NY : ASME Press. - 0791842029 ; , s. 603-604
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Konferensbidrag (refereegranskat)abstract
- Demands for decreased environmental impact from vehicles are resulting in a strong push for decreased engine oil, fuel consumption and weight. New machining and coating technologies have offered ways to attack these problems. Engine oil and fuel consumption are to a great extent controlled by the topography of the cylinder liner surface and it is therefore important to optimise this surface. Recent engine tests have shown a reduction in oil consumption when using cylinder liners with a smoother finish than that given by the current plateau honing. However, engine manufacturers are hesitant to introduce smoother liner surfaces because of fears of severe wear and scuffing. There is also the possibility that smoother liner surfaces may be more sensitive to the choice of piston ring finishes. This paper therefore seeks to investigate the functional performance and resistance to wear of these smooth cylinder liners and the mating top ring surfaces. Copyright © 2005 by ASME
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| 4. |
- Barth, Henrik, 1971-, et al.
(författare)
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From Traditional Manufacturing to Digital Manufacturing : Two Swedish Case Studies
- 2023
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Ingår i: Innovation - Research and Development for Human, Economic and Institutional Growth. - Rijeka : InTech. - 9781837689965 - 9781837689972 - 9781837689989
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Bokkapitel (refereegranskat)abstract
- Digital manufacturing can produce new and advanced tools more rapidly and at lower cost than traditional manufacturing. This new technology means manufacturers need to develop innovative business models adapted to this change in the manufacturing landscape. With digital manufacturing, companies have both an opportunity and a challenge. They can enter new markets where large-scale production provides competitive advantage. They can enter niche markets that become more attractive as old boundaries and structures lose relevance. Yet their additive manufactured components must meet the same standards set for conventional manufactured components. However, we know little about how companies manage this change as they make the transition from traditional manufacturing to digital manufacturing. This chapter presents two co-creation digital manufacturing projects between university researchers and Swedish companies. In each project, the goal was to develop sustainable and efficient digital production methods that offer tailor-made product solutions. Various technical methods used in the projects are described as materials, and prototypes are developed, tested, and analyzed.
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| 5. |
- Barth, Henrik, 1971-, et al.
(författare)
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The use and abuse of 3D-printing from a business model perspective
- 2016
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Konferensbidrag (refereegranskat)abstract
- The paper analyses changes in user activities and behaviour across different types of actors following the introduction of 3D printers. 3D printing, or additive manufacturing, has been claimed to disrupt manufacturing, allowing firms to move from prototyping to full-scale end-part production and replacement part production in a one-step process. 3D printing has many different uses, for example, the manufacturing of toys, shoes, lamps and fashion accessories, and by implication many different types of users and buyers. There are few empirical studies on the types of uses and users of 3D, hampering our understanding in what ways the 3D printers may change the behaviour of users, and whether 3D printers affect the likelihood and the nature of entrepreneurship or business model innovation. To investigate this, a model was created based on the 3DP literature. The model is applied on a distributor customer database and four interview-based illustrative case studies. The empirical findings show that the use of 3DP a) lowers the knowledge and resource barriers for experimentation and entrepreneurial entry, b) increases product and concept prototyping in product development, c) provides a potential for business model innovation by expanding the boundaries of the firm upstream and downstream, and d) becomes a ticket for entrepreneurial entry. Based on our results, the paper suggests that the potential of 3D printers alter user innovative activities is high but most of the potential is latent.
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| 6. |
- Barth, Henrik, 1971-, et al.
(författare)
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The use and abuse of 3D printing - Towards a mobile business model framework
- 2019
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Ingår i: International Journal of Engineering Research and Applications. - Ghaziabad : International Journal of Engineering Research and Applications. - 2248-9622. ; 9:11, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- The paper aim to clarify changes in user activities and behaviour across different types of actors following the development of 3D printers. It proposes a mobile business model and outlining the features of development for direct digital manufacturing.The exploratory study show that the use of 3D printing a) lowers the knowledge and resource barriers for experimentation and entrepreneurial entry, b) increases product and concept prototyping in product development, c) provides a potential for business model innovation by expanding the boundaries of the firm upstream and downstream, and d) becomes a ticket for entrepreneurial entry
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| 7. |
- Berglund, Johan C, 1978, et al.
(författare)
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Milled die steel surface roughness correlation with steel sheet friction
- 2010
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Ingår i: CIRP Annals - Manufacturing Technology. - Bern : Elsevier BV. - 1726-0604 .- 0007-8506. ; 59:1, s. 577-580
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Konferensbidrag (refereegranskat)abstract
- This work investigates correlations between the surface topography of milled steel dies and friction with steel sheet. Several die surfaces were prepared by milling. Friction was measured in bending under tension testing. Linear regression coefficients (R^2) between the friction and texture characterization parameters were tested. None of the height, spacing, material volume, void or segmentation parameters showed good correlations. Developed area, rms surface gradient, relative area and complexity showed strong correlations (R^2 > 0.7). For area-scale fractal complexity the correlation increases markedly at scales below 200 μm^2, with a maximum R^2 of 0.9 at 50 μm^2.
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| 8. |
- Berglund, Johan C, 1978, et al.
(författare)
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Surface Finish and Roughness Measurement in Die and Mould Manufacturing
- 2008
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Ingår i: Proceedings of the 2'nd Swedish Production Symposium. ; , s. 385-391
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Konferensbidrag (refereegranskat)abstract
- In die and mould manufacturing, the method used for quality control of finished surfaces is usually visual and tactile inspection of the finish, which is not easily quantifiable. In this study, an evaluation of the connection between surface finish appearance and measured surface roughness was carried out using scale-sensitive fractal analysis to find functional correlations and to determine suitable cut-off limits for functional data filtration. A selection of ball nose end mills in combination with two different tool steels (hardness 39 and 47 HRC) were used to manufacture surfaces that were measured. It was found that the method employed in this study for evaluating functional correlations and designing filters worked well. It was also found that there is a correlation between the surface roughness parameter Sq and the surface finish appearance and that this correlation is stronger in certain wavelengths on the surface.
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| 9. |
- Bergman, Martin, 1985-, et al.
(författare)
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Surface appearance and impression
- 2012
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Ingår i: Proceedings of the International Conference on Kansei Engineering and Emotion Research. - Tainan : Department of Industrial Design, National Cheng Kung University. - 9789860324884
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Konferensbidrag (refereegranskat)
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| 10. |
- Bergman, Martin, 1985-, et al.
(författare)
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Surface design methodology : challenge the steel
- 2013
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Ingår i: Metrology and Properties of Engineering Surfaces, 2013. - Bristol, UK : Institute of Physics Publishing (IOPP). ; 483:1, s. Art. no. 012013-
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Konferensbidrag (refereegranskat)abstract
- The way a product or material is experienced by its user could be different depending on the scenario. It is also well known that different materials and surfaces are used for different purposes. When optimizing materials and surface roughness for a certain something with the intention to improve a product, it is important to obtain not only the physical requirements, but also the user experience and expectations. Laws and requirements of the materials and the surface function, but also the conservative way of thinking about materials and colours characterize the design of medical equipment. The purpose of this paper is to link the technical- and customer requirements of current materials and surface textures in medical environments. By focusing on parts of the theory of Kansei Engineering, improvements of the companys' products are possible. The idea is to find correlations between desired experience or «feeling» for a product, -customer requirements, functional requirements, and product geometrical properties -design parameters, to be implemented on new improved products. To be able to find new materials with the same (or better) technical requirements but a higher level of user stimulation, the current material (stainless steel) and its surface (brushed textures) was used as a reference. The usage of focus groups of experts at the manufacturer lead to a selection of twelve possible new materials for investigation in the project. In collaboration with the topical company for this project, three new materials that fulfil the requirements -easy to clean and anti-bacterial came to be in focus for further investigation in regard to a new design of a washer-disinfector for medical equipment using the Kansei based Clean ability approach CAA. © Published under licence by IOP Publishing Ltd.
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