| 1. |
- Anderberg, Cecilia, et al.
(författare)
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Alternative descriptions of roughness for cylinder liner production
- 2009
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Ingår i: Journal of Materials Processing Technology. - Amsterdam : Elsevier. - 0924-0136 .- 1873-4774. ; 209:4, s. 1936-1942
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Tidskriftsartikel (refereegranskat)abstract
- The roughness of stratified surfaces such as cylinder liners, produced by plateau honing, is functionally important in their tribology but is notoriously difficult to characterise. An issue in manufacturing quality control related to their tribological function is the comparative ability of various roughness characterisation systems. In this paper the Rk family of parameters is compared with the Rq family as regards stability and discrimination. When coefficients of variation of the two parameter families are compared as a measure of stability, CVs of individual parameters vary between 8% and 20% but do not seem to indicate a clear advantage to either family. When the correlation of parameters within and between the two groups is computed as a measure of relative discriminative ability, many parameters are found to be highly correlated, to the point where values of Rpk and Rpq are effectively indistinguishable. The relative robustness of the parameters is also established by simulation of surface or measurement artefacts: outlying peaks and valleys, high-frequency noise, changes in stylus or skid radius, changes in high-pass filter and in assessment length. Outlying peaks cause a large increase in Rpk, while outlying valleys have little effect. The Rq parameters are more sensitive to high-frequency noise than the Rk parameters. Increasing the stylus radius reduced the valley parameters, while adding a 25 mm radius skid increased Rk and Rpq by as much as 15%. Increasing the short-wavelength cut-off from 2.5 m to 8 m reduced most parameters, particularly the peak parameters, while replacing the robust Gaussian filter used throughout by a valley-suppression filter had little effect. Finally reducing the assessment length from 17 mm to 4 mm decreased the values of many parameters by up to 11%. Increasing plateau honing time decreased plateau roughness, while increasing pressure during coarse honing increased valley roughness, but these changes could not be correlated with roughness parameters. This suggests that the optimum parameter set has not yet been found. 2008 Elsevier B.V. All rights reserved.
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| 2. |
- Anderberg, Cecilia, et al.
(författare)
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Combined SEM and Stylus Profiling Sensoring for Improved Cylinder Liner Honing
- 2006
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Ingår i: Proceedings of Austrib 06 - International Tribology Conference. - Brisbane : Queensland University of Technology. ; , s. 6-
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Konferensbidrag (refereegranskat)abstract
- The demands on decreased environmental impact from vehicles are resulting in a strong push for decreased engine oil and fuel consumption.Recent engine tests have shown a promising reduction in oil consumption when using cylinder liners with a smoother finish than the current plateau honing.One approach to produce smoother liner surfaces is to replace SiC ceramic honing stones with diamond tools. However, even though the diamond honing process results in higher productivity, improved quality control is needed to monitor the degree of cold worked material - “blechmantel” (German), and the resulting risk of increased wear and scuffing.A number of petrol and diesel engine cylinder liners have been mapped to be able to verify the quality and consequences, in terms of wear and function, of the honing process. A new mapping method, combining SEM images and quantitative image analysis with traditional 2D profilometry has been developed and tested in this study. The surface mapping method developed was employed before and after the test to study effect of running-in wear on the surface, features characterized with the SEM- and the 2D profilometer.The results show that combining SEM- and profilometric methods gives a good picture of the effects of varying the cylinder liner pressure and roughness. The core roughness decreases more for diesel liners than for petrol liners.. A probable cause is that the more severe diesel high pressure run-in conditions are able to effectively “truncate” the plateaux and remove residing plastically deformed un-cut honing residues while the less severe petrol liner conditions do not manage to remove the blechmantel and irregularities to an important extent.
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| 3. |
- Anderberg, Cecilia, et al.
(författare)
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Cylinder Liners and Consequences of Improved Honing
- 2006
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Ingår i: Proceedings of Nordtrib conference 2006, Helsingor, Danemark. ; , s. 13-
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Konferensbidrag (refereegranskat)abstract
- The demands on decreased environmental impact from vehicles are resulting in a strong push for decreased engine oil and fuel consumption. Engine oil and fuel consumption are to a great extent controlled by the topography of the cylinder liner surface.Recent engine tests have shown a promising reduction in oil consumption when using cylinder liners with a smoother finish than the current plateau honing.One approach to produce smoother liner surfaces is to replace SiC ceramic honing stones with diamond tools. However, event though the diamond honing process results in higher productivity, improved demands of quality control is needed to monitor the degree of cold worked material - “blechmantel” (German), and the resulting risk of increased wear and scuffing.A number of petrol and diesel engine cylinder liners have been mapped to be able to verify the quality and consequences, in terms of wear and function, of the honing process. A new mapping method, combining SEM images and quantitative image analysis with traditional 2D profilometry has been developed and tested in this study. The liners where tested in a reciprocating rig of 8 mm stroke and with a frequency of 10 Hz, simulating the top-dead center conditions in a running engine.The tests where carried out in high- and low pressure conditions with smooth respectively rough liner roughnesses against PVD coated piston rings. The developed surface mapping method was employed before and after the test to study effect of running-in wear on the surface, features characterized with the SEM- and the 2D profilometer.The results show that combining SEM- and profilometric methods gives a good picture of the effects of varying the cylinder liner pressure and roughness. The core roughness decrease more for diesel liners than for petrol liners. In average (rough and smooth liners) the diesel core roughness decrease 265% while the petrol liners average on a 60% decrease. Blechmantel- and Irregularities ratio show a high sensitivity to varying conditions and decrease 1180% to 100% for the diesel liners while the parameters increase between 106% to 18% for all the petrol liners. A probable cause is the more severe diesel high pressure run-in conditions are able to effectively “truncate” the plateaux and remove residing plastically deformed un-cut honing residues while the less severe petrol liner conditions not manage to remove the blechmantel and irregularities in an important extent.
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| 4. |
- 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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| 5. |
- Anderberg, Cecilia, et al.
(författare)
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Liner Surface Improvements for Low Friction Piston Ring Packs
- 2009
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Ingår i: Society of Tribologists and Lubrication Engineers annual meeting & exhibition 2009. - Red Hook, NY : Curran Associates, Inc.. - 9781615674374 ; , s. 455-459
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Konferensbidrag (refereegranskat)
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| 6. |
- 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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| 7. |
- 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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| 8. |
- 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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| 9. |
- 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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| 10. |
- 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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