Logistics of material flow in flexible manufacturing and assembly cell.

Mudrikova, Andrea ; Hruskova, Erika ; Velisek, Karol 等

1. INTRODUCTION

Automatisation has important vocation in the development of machine production. It brought new quality to production, new level of productivity, distinctive increasing of flexibility in production whereupon final increasing of quality and efficiency. Yet 50th years ago was evident that biggest potential of manufacturing was in promt reaction possibility of market requirements. Idea of constantly production costs decreasing and of making easier the workpiece production to different, led to development of flexible manufacturing system.

Last years the cell production is one of the most important studies of production organisation. By cell production is created relations between machines, there are economize production time and space. Manufacturing cells connect and study many advantages from other kinds of production as f. e. from mass production it is production frequency and from part production it is mainly production flexibility.

2. FLEXIBLE MANUFACTURING SYSTEMS

High elaborateness of technological process is characteristic for production and their secrecy. Conception of production automatisation is different by production characteristic. Automatised manufacturing systems are manufacturing devices with variant automation level. It means level with manufacturing or not manufacturing activities and with variant level of particular subsystems integration. Flexible manufacturing system (FMS) is exerted name for automatised manufacturing systems in repetitive production where is necessary high flexibility rate of manufacturing programme variance. FMS--Flexible Manufacturing System must provides for firstly follow three activities:

Manufacturing--concrete technological proces, Directing--synchronizing of mainly and accessory activities, functions of all devices that are providing for workpiece production inside FMS. One part of this area is controlling of:

--Production accuracy - particular trend of workpiece accuracy is predicted on the base of periodical enumerations

--Monitoring and diagnostic of transport and storage--resulting of storage places, of transport ways for workpieces, tools, measuring tools and accessories that are necessary for manufacturing process. (Zvolensky et al., 2008).

By organisation structure the flexible manufacturing systems are divided into:

--Flexible manufacturing cell,

--Flexible automatised line,

--Flexible automatised operation,

--Flexible automatised plant.

Flexible manufacturing cells content technological device with program directing with equipments of technological process automation that works autonomous. There are realised various cycles with connecting possibility to higher system. Workpiece containers with technological palletes, fixture devices, devices for changing tools, for waste removal and diagnostics are the automation accessories. Flexible manufacturing cell is associated with industry robot while creates robotised technological complex. Present cells are constructed as manufacturing or as assembly. They are designed with using external manipulation devices for manipulation with semifinished products or workpieces. (Zvolensky & Javorova, 2006).

3. FLEXIBLE MANUFACTURING CELL IN INSTITUTE OF MANUFACTURING SYSTEM AND APPLIED MECHANICS

Prototype of flexible manufacturing cell Fig. 1 that is in Institute of Manufacturing System and Applied Mechanics presented multifunctional manufacturing--assembly device introduces new philosophy in creating new complex production. Different from present flexible manufacturing and assembly system is in the operation area. In this operation space the final product (workpiece) is not only manufactured but assemblied too. Final workpiece is assemblied from workpieces that are manufactured in system and from workpieces that are transported to system from backround. Important innovation symbol of this concipated manufacturing--assembly system is that for manipulation and assembly is not use external industrial robot. Changeable grippers for manipulation and assembly are positioned at structure last unit of device--in this case on vertical axis parallel with operatined spindle. Realisation and utilisation of this manufacturing--assembly system conception designed as flexible manufacturing--assembly cell brings smaller built surface, lower economics and higher coefficient of manufacturing device utilisation. (Kost'al et al., 2005) It contents of these base parts:

* shelf storage device,

* rotary feeding device,

* multifunctional industry robot,

* rotary fixture device.

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

Shelf storage device (Fig. 2) is used for storage semifinished workpieces, particular workpieces and final product. By shelf storage device particular palletes are chosen and positioned to rotary feeding device. This device provides for palettes feeding into and from operational space of multifunctional industry robot. By robot are realised manufacturing and assembly operations. Manufacturing system is built on the table construction with serious kinematics that contains three electric powers. Frame is built of aluminium profiles. Three linear systems create carthesian operational place. The device is directed by industry robot. (Horvath & Danisova, 2008) For manipulation and assembly are using changeable grippers positioned at the last element. System using of efector change increases productivity and universality of complete system. Manufacturing process of workpiece consists five periods:

* Storage of semifinished products and its transport to manufacturing device,

* Semifinished product machining to final workpiece,

* Manipulation with particular elements,

* Assembly of particular elements to final product,

* Manipulation with final product and its storage before expedition. (Kost'al, 2006)

4. MATERIAL FLOW

Generaly for the resultfull running of manufacturing process is important to provide for continuous flow the material, raw material, semifinished products, and etc. By term material flow we mean organised material moving from production input throught all periods of storage, transport and manufacturing processes to output of final products. Analysis of material flow is one of the main points of the final analysis of the manipulation with materials. Next, main proposition of complete material flow analysis is for the process of material moving too. Kind, number, capacity, weight, shape and dimensions influence the kind of manipulation and defined the requirements for manipulation, transport and storage of manipulated material and product.

Principles of racional manipulation with material:

--To create striaght, as short as possible transport ways,

--To design manufacturing process and solution of disposition with reference to optimal material flow,

--If it is possible, to use gravitation for material moving,

--To make optimal quantity, sizes and weights of transported units,

--To design all manipulation, transport and storage operations as effectively as possible.

--To resolve manipulation completely it means from the view of final factory and in relation with out plant material flows,

--To use possibility of type manipulation device,

--To speculate about optimal using of transport and manipulation devices (minimum 60%),

--To respect ergonomic and syfety requirements.

For the description of material and information flow in the production of this flexible manufacturing cell must be defined it means to choose type range of the workpiece.

5. CONCLUSION

Failure--free, effectively and synoptical operations of material flow are provided for information flow. Information flow is depended on rationalization of material flow. It is in central position in logistics. Before all kinds of material movement could be and follows information. Every this steps are necessary to information flow attend and brings that information on that is possible to adopt a decisions. Mojority of problem resolution is in the optimalisation of material and information flow and their application into highest level of automation and mechanisation into manipulation and transport processes. In the material flow projecting, here is necessary to know that aim of the project is not transporting and storaging material because the price of these operations is high and the material rate is not higher by them.

Paper was created thanks to national project VEGA 1/3193/06 Multifunctional manufacturing--assembly cell.

6. REFERENCES

Horvath, S.; Danisova, N. (2008). Power elements of flexible manufacturing and assembling systems, Proceedings of International Doctoral Seminar 2008, pp. 130-136, Smolenice, Slovakia, 18. - 20. May 2008, ISBN 978-80-8096 -058-2, AlumniPress Trnava

Kosfal, P.; Javorova, A. & Zvolensky, R. (2005). Flexible assembly system with automated tool changing, Proceedings of 6th International conference Systems reducing hazards in operational processes of Machines and Equipment. KOMTECH 2005, pp. 155-162, ISBN 83-922 681-4-8, Poland, 15.-17. November 2005, Komdruk Komag Sp. z.o. o., Zakopane

Kost'al, P. (2006). Clamping device for manufacturing cell.--VEGA 1/3164/06. In: Materials Science and Technology [online].--ISSN 1335-9053.--Roc.6, c. 3

Zvolensky, R.; Javorova, A. (2006). Flexible manufacturing and assembly cell with automated tool changing system. In: RaDMI 2006: Proceedings on CD-ROM. International Conference. Budva, Montenegro, 13-17. September 2006. Trstenik: High Technical Mechanical School of Trstenik, 2006.--ISBN 86-83803-21-X.--pp. 1-6

Zvolensky, R.; Ruzarovsky, R.; Kosfal, P.(2008). Design of automated disassembly devices. In: MicroCAD 2008: International Scientific Conference. [Miskolc], 22-23 March 2008. Section K: Machine and Construction Design. --Miskolc: University of Miskolc, 2008.--ISBN 978-963661-812-4 O.--ISBN 978-963-661-822-3.-pp. 51-56