| 1. |
- Anderberg, Staffan, 1981-
(författare)
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A study of process planning for metal cutting
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Process planning as a function for competitiveness is often neglected. However, as an intermediary between product development and manufacturing, it holds a key function in transforming product specifications and requirements into a producible process plan. Demands and requirements should be met concurrently as manufacturing costs and lead times are minimised. The focus of this thesis is the act of process planning, where the use of better methodologies, computer-aids and performance measurements are essential parts. Since process planning has the function of transforming demands and requirements, changing customer and regulative requirements are vital to regard. Since environmentally benign products and production increases in importance, the research presented in this thesis includes a CNC machining cost model, which relates machining costs to energy consumption. The presented results in this thesis are based on quantitative and qualitative studies in the metal working industry. This thesis has contributed to an enhanced understanding of process planning to achieve better performance and important areas for improvements. Despite a 50 year history of computerised process planning aids, few of these are used in the industry, where manual process planning activities are more common. Process planning aids should be developed around the process planner so that non-value adding activities, such as information management and documentation are minimised in order to allow more resources for value adding activities, such as decision making. This thesis presents a study of systematic process planning in relation to perceived efficiency. This correlation could however not be verified, which opens up for further studies of other possible explanations for process planning efficiency. Process planning improvements in the industry are difficult to make, since there is little focus on process planning activities and limited knowledge about actual performance hereof. This means that measures taken regarding process planning development are difficult to verify.
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| 2. |
- Anderberg, Staffan, 1981-, et al.
(författare)
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A survey of metal working companies’ readiness for process planning performance measurements
- 2009
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Ingår i: IEEE International Conference on Industrial Engineering and Engineering Management, IEEM 8-11 sep, 2009, Hong-Kong. - 9781424448708 ; , s. 1910-1914
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Konferensbidrag (refereegranskat)abstract
- The paper presents an investigation regarding the potential and the readiness for implementing performance indicators and performance measurement systems of the process planning work for metal working companies. The paper is based on a questionnaire survey distributed to process planners in the Swedish metal working industry. The main outcome of the investigation is a foundation for understanding the implementation of performance measures of the process planning work for CNC machining. The survey revealed a few strengths and short comings in the studied companies.
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| 3. |
- Anderberg, Staffan, 1981-, et al.
(författare)
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CNC machining process planning productivity – a qualitative survey
- 2009
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Ingår i: Proceedings of <em>The International</em> 3'rd <em>Swedish Production Symposium</em>, SPS 09. - 9789163360060 ; , s. 228-235
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Konferensbidrag (refereegranskat)abstract
- Process planning is the link between design and manufacturing and consequently an important function, since it influences many of the company objectives. However, many companies have little knowledge about their process planning function and the efficiency is thus not optimal. The paper focuses on the automation level of process planning as a mean to improve process planning efficiency. Six CNC machining companies was interviewed and accordingly analysed through a five dimensional automation level model to understand their process planning work. The main findings are that the automation level is low and concurrent engineering is lacking in many of the investigated companies.
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| 4. |
- Anderberg, Staffan, 1981-, et al.
(författare)
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Production preparation methodology in Swedish metal working industry - a State of the Art investigation
- 2008
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Ingår i: Swedish Production Symposium, Stockholm 18-20 November 2008. Proceedings. - Stockholm : The Swedish Production Academy. ; , s. 443-450
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This article presents a brief state of the art in the Swedish metal working industry regarding the production preparation process for the machine centre. The article is based on a relationship model from which a questionnaire was developed. The model incorporates the perceived preparation process efficiency, the amount of systematic preparation work, in relation to the companies’ premises as possible causes. The investigation is based on a general hypothesis that a more systematic approach in the preparation process leads to higher preparation process efficiency. This hypothesis was supplemented by two more hypotheses and additional analyses to create an understanding of the situation. The main finding in this investigation is that there appear to be no relationship between increased ystematic preparation work and perception of higher preparation efficiency. The investigation also indicates that many metal working companies have little knowledge about the performance of their preparation process and that there is an efficiency improvement potential of nearly 30%.
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| 5. |
- Beno, Tomas, et al.
(författare)
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Green machining : improving the bottom line
- 2009
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this paper is to present how Green machining can be established in the metal working industry for taking immediate actions towards a more environmental friendly manufacturing, but also to address areas for research in order to advance towards a more sustainable manufacturing industry. An often overlooked approach is to use the knowledge about the specific cutting energy and its dependency upon machining parameters in order to establish a machining strategy that leads towards a more energy efficient production, but also contributes to increased productivity and thereby improving the bottom line as well. The paper has a production preparation perspective and thus presents the areas where a green machining strategy is applicable.
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| 6. |
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| 7. |
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| 8. |
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| 9. |
- Daghini, Lorenzo
(författare)
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Theoretical and experimental study of tooling systems : passive control of machining vibration
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Vibration control has been and still remains a subject of primary importance in modern manufacturing industry. To be able to remove high volumes of material in shorter time as well as to be able to get the right quality of the parts at the first time are goals that many shops would like to achieve. Tooling systems, and especially cantilever tools, and cantilever structural units of machine tools are the least rigid components of machining systems and therefore the most prone to vibration. Boring tools are often encountered as rotating tools in machining centres or as stationary tools in internal turning. In this thesis the focus is on internal turning. Internal turning is widely known as a very delicate operation and it is often carried out with cutting parameters far from optimal, from a productivity point of view, due to limitations imposed by vibration. Another type of tooling system whose functionality is impaired by vibration is the parting-off tool. The design of damped parting-off tool is one of the focus of this thesis as well. Vibration control has the purpose to achieve an efficient energy dissipation of a vibrational system. Basically this is achieved by controlling the damping of the system. Since damping involves the conversion of energy associated with a vibration to other forms, there are several mechanisms to remove energy from a vibrating system. Typically these mechanisms are divided in two classes: 1. Mechanisms that convert mechanical energy to heat, i.e. passive damping. 2. Mechanisms that transport energy away from vibrating systems, i.e. active damping. Both these techniques have been used during the years and both have been giving excellent results. The active vibration control mechanisms are more expensive and not suitable for machining due to the cables they necessitate that could interfere with the machining operation. This work proposes an original approach to vibration damping in machining systems, the objects of vibration dissipation being the structural components on the link between turret and cutting insert. The idea is to use composite materials to create damping interfaces between and within the different structural components. Different clamping system designs are being compared in order to see how these influence the performance of the machining system and different cutting inserts have been compared for machining hardened steel. The newly designed components have been going through both extensive off-line (modal analysis) and on-line dynamic testing (machining test) and the results show that the new tool holders used in combination with hydrostatic clamping system are the most optimal solution among the tested ones. The new design for the turret has been giving promising results and more can be achieved by bringing minor changes to it, these changes are being implemented at the time of writing this thesis.
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| 10. |
- Repo, Jari, 1976-, et al.
(författare)
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New Aspects on Condition Monitoring of Machine Tools and Machining Processes
- 2009
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Ingår i: The Swedish Production Symposium (SPS'09). ; , s. 27-33
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A general trend within the manufacturing community and in particular the aerospace industry is that the requirements on the manufacturing of components are subjected to ever tighter tolerances and surface integrity restrictions. In order to fulfil these requirements a lot of effort has been carried out to non destructive testing of the produced part. However, the final objective in the first place must be to assure a robust process. One way to achieve a robust process is to continuously monitor it. This may require additional sensors which increase complexity and adds cost. This paper presents suggestions and experimentally achieved results into the extended use of already existing sensors in the machine tool. The basic idea is to show how these sensors can provide additional information about the machine tool itself and how they can be used for monitoring the process as well as to support maintenance activities. The Poincaré analysis method is applied to the position encoder signals to reveal the underlying dynamics when the machine tool structure is excited with a periodically varying load.
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