Product design suitable for assembly.

Peterka, Jozef ; Senderska, Katarina ; Vaclav, Stefan 等

1. INTRODUCTION

The effective assembly assumes a product that responds to the requirements of manipulation and joining of separate parts into higher units (subassemblies and final products). In order to take in the consideration all aspects the designers need to understand to the assembly processes and procedures. The development of the complex products is teamwork. The basic problem, which we must to concern, is how the parts behave during the transport, manipulation, joining and testing. In this context are in the foreground different properties of the parts and components as by evaluation of their function.

2. PRODUCT DESIGN BACKGROUND

To ensure the required product function it is possible to design the product by various concepts often by using of entire different concepts and design principles (Vaclav 2005). By comparison of two products, that ensure the same function in the same range and in a comparable quality (so that they have a comparable utility value) can be observed great differences. It can be used not only other design principles but also other materials, forms and dimensions of the parts and components. The products have often other relative position of the parts and components, other tolerance limits and etc (Lotter & Wiendahl 2006). According to the design quality it is then possible to produce and to assemble the product relatively simply without serious technical problems and by relatively low costs or in the limit case is the production and also the assembly complicated or unacceptable from the point of view costs. A lot depends also on the production batch size. The design of a product with a great batch size should be differ from the design of the same product to the piece or robotized assembly (Boothroyd & Dewhurst 2006). The significance of the product design and their influence to production and assembly can be confirmed also by following data. Independently from the product kind are in the design process specified more than 70% manufacturing cots including costs of the assembly. 70-80% of the possible savings are depended on the product design, 10-20% are depended on the changes of technology, production means, fixtures and tools. 5-10% are connected with changes of the organization.

3. METHOD AND TOLL TO PRODUCT ANALYSIS FROM THE POINT OF VIEW ASSEMBLY

For the product design analysis from the point of view assembly was proposed a method issued from the decision analysis. The basis of this approach is a set of rules and recommendations for the assembly and the collection of questions. The analysis and evaluation is divided into four steps: product, parts, joints and assemblies. The method assumes to answer at five main questions in all four steps. The "answer" is a point evaluation and an own creative proposal that can be inspired so by existing stored proposal for similar products, parts, joints or assemblies as by the set of rules and recommendations (IPA 2007).

The developed access tool is dedicated to analysis of medium complex mechanical products and was tested at several products (Senderska 2006).

Main functions:

* Refill and modify the contained rules and recommendations.

* The evaluating questions/criteria selection and definition.

* Definition of the point values for decision analysis.

* Product/products analysis.

* Analysis of the parts, joint and subassemblies.

The conception enables also to modify the material, part symmetry, kind of the joint and other parameters assortment. The whole system is opened for further modification for instance as comparison of two or more variants of the products, evaluation from the point of view disassembly etc. For better information the system can include also drawings, 3D models or photographs of the products, parts, joints and subassemblies.

On the figure 1 is shown the main screen for the product data input.

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The figure 2 shows the screen with processed data and recommendations to product change.

In this system was created some default reports. On the figure 3 is shown an output report of the product analysis. From the data and analysis results contained in this system can be created various reports according to the requirements.

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The basic of this approach is a list of rules and recommendation for product design from the point of view assembly. The system is created so that in time of the system using can be the rules, recommendation and examples continuously refilled. On the figure 4 is shown the screen with the list of rules and appropriate examples.

The questions can also be modified or changed. On the figure 5 is shown the screen to creation of a relation between questions and defined rules. By changes in this filed must be clearly that the obtained results can be depended on the putted questions. This must be considered in the case of comparison of such results that was obtained by using different questions.

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4. TOPICS TO FURTHER RESEARCH

In this phase of the development is performed an augmented verification in several directions. First augmented verification is oriented to the tool using for the analysis of various assembled products. The target is to verify the scope of the tool using from the point of view product variety. The second researched aspect is the possibility of the integration into the general procedure of the assembly process and system design and planning. The further considered characteristic is the product design change supporting. The main goal is to become the impulses and experiences from the industry. Important can be also the integration into the education. On the basis of the obtained answers to the above putted questions can be considered also the toll modification, selection of the other program tool or Internet publishing.

5. CONCLUSION

Experiences with creation and application of the developed tool to product design analysis from the point of view assembly show, that it is one of the possible directions in the design for assembly supporting. The tool can be easy used, modified and refilled. Important in also, that by this tool can be stored and managed any previous proposed solution of part, joint assemblies or product changes.

Acknowledgements

This paper was elaborated in the frame of the projects: Objective method of assembled product design and assembly system VEGA No.: 1/3163/06 and Innovative education materials for bachelor study line Automobile manufacturing KEGA No.: 3/6342/08 Supported by Ministry of Education of the Slovak Republic. We are indebted for support.

6. REFERENCES

Boothroyd, G. & Dewhurst, Inc. (2006). Design For Assembly, Available from: http://www.dfma.com Accessed: 03-04

Fraunhofer institute (IPA) (2007). Design For Assembly and Manufacturing, Stuttgart, Available from: www.ipa.fhg.de Accessed: 2007-08-05

Lotter, B. & Wiendahl, H.P. (2006). Assembly in Production Industrial, ISBN 13978-3-540-21413-7 s.531, Springer, Berlin Heidelberg, New York

Senderska, K.; (2006). Approaches and Tools to Evaluation Support of Product Construction for Assembly, In: Inovations Transfer, SjF TU, pp. 214-215, ISBN 80-8073701-0, Kosice

Vaclav, S. (2005). What is the Assembly? Proceedings of 13th International Scientific Conference CO-MAT-TECH 2005, pp. 1289-1294 ISBN 80-227-2286, Trnava