Numeric expression of the quality of production technology.

Barborak, Oto ; Cervenansky, Jaroslav ; Bozek, Pavol 等

1. INTRODUCTION

Tendency to ensure car's high technical and operational parameters, and consequently successful realisation of any difficult technical system and mechanism comes out from perfect knowledge of operational conditions, knowledge of operation--technical characteristics and parameters of own system. This fact conditions to increase requests for technical level of measurement, actual time of measure results, precision of measurement results, possibility of measurement results processing, level of measurement automation i.e. measurement as method of objective quantification of physical values, or about relation between two or higher number of physical values. The analysis of results achieved in solving and car security area in the whole scale of connectivity and relations confirms that the role of laboratory verification is not replaceable in the new quality management system. A complex approach to the questions of testing in a new quality management system is getting inevitable.

The logic part of the car production process and, as the analysis of trends in car industry shows, the effect of solution in testing automation has an objective need (Stollmann, 2001). It is necessary to concern the automation data gathering about component operation mode in real conditions. It is possible to define their reliability based on gathered data about operating and component failure accepting. It is possible to design device for test tracing of components and test method after defining critical elements.

2. PROBLEMS WITH QUALITY MANAGEMENT

Today brings significant changes in product area, in all industry forwarded countries. Understanding of changes in quality is possible to characterise as a movement from clearly technical soundness to integral product quality. Pro-duct quality became significant criteria of science and research effect and big productivity reserve of common work.

This general definition of development in quality field and objective need to continually increase quality in application for cars, which reports to increasing requirements for high technical and operating parameters, requires:

* to direct systematically all related actions, i.e. arrange questions of quality management to whole creating process of gearbox,

* to complex evaluate quality, which requires to use quantitative evaluation,

* to identify quality, i.e. to evaluate reached quality level, which has basic importance to control whole creating process and innovation gearbox process,

* to compare objective gearbox parameters with comparable world level types directly by measuring of chosen parameters, or indirectly by data from progressive technical information.

Quality management is concerned as complex, if it is expanded to all fields, which can have influence the final gearbox quality, including user's operation. This system, which prevails today in all advanced countries, leads to create conditions in flow pre-production, production and after production activities by using objective methods for apply testing need (Stollmann, 2006).

2.1 Analyse of reliability influence to profitability and economic effect

Before analysis of gearbox reliability influence to economic effect, it is important to realise basic ideas of reliability theory and to check relation of coefficients quantitative reliability to economic coefficient and efficiency coefficient. Related basic ideas:

Quality of product is properties summary, expressing ability to fulfil functions, for which it is dedicated. We take into account also product economic coefficients, its outfit by accessories, spare parts etc., as well as premises, which producer creates to provide services connected to product use.

Reliability is general object attribute, reposing in ability to fulfil requested functions with keeping of values for specified operational coefficients in specified limits and in time according to technical conditions. Reliability is one of the most important groups of product quality marks.

3. RELIABILITY TRIALS METHODICS PROPOSE

Automated reliability verifying and gear mechanism life cycle is the goal of test.

It is necessary to change dimensions, eventually construction nodes of least reliable elements before test. Test methodology is deduced from the way of speed degree gearing during car running. Speed degrees gearing flow is introduced in previous part. The flow repeats always the same way with aspect to chosen speed degree.

It is necessary to assure handle control power, path length of default and path length of speed degree gear. Gear mechanism lines effort by power intensity, which is prescript in tolerances during car running and followed construction nodes, ensure fulfil these conditions (Suriansky & Nascak 2000).

Whole system is specified to follow up gear mechanism in aspect of car reliability during car running. Test commerce car measuring results are base to propose the test method about control mechanism use in aspect of number of individual speed gear. The selected ratio must be kept during testing and gear mechanism test in number, what is used and record in tables. Proposed ratio method seems to be the most suitable.

3.1 Ratio method

Ratio method comes from distribution of percentage ratio elements use of gear mechanism during speed degrees gearing. Values assigned in tables are the base of distribution. Maximum level is reached when each component of gear mechanism will be running by distribution in table one during follow-up. Mathematic interpretation of number of gear [z.sub.u] in one level and trial process is:

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (1)

Where:

[n.sub.1]-[n.sub.5]--number of gear in u-level

u--dividing level of max. number of gear,

[z.sub.1i]-[z.sub.5i.]--number of gear of individual speed degrees,

n--maximum number of speed degrees gear of related speed.

Example: if we want to follow-up gear mechanism element reliability in speed degree 5, then number of individual speed degrees gears will be:

[n.sub.1] = 97555 / 5 = 19511 times

[n.sub.2] = 114100 / 5 = 22820 times

[n.sub.3] = 154050 / 5 = 30810 times

[n.sub.4] = 91300 / 5 = 18260 times

[n.sub.5] = 18805 / 5 = 3761 times

Use coefficient estimate exactness or gear mechanism element reliability is higher, when dividing level is higher. It is important to know, same number of gears ratio in every level is kept in ratio method.

The graph of the testing method would show the ratio number of gears of speed degrees in one level. Level 5 has 5 times smaller number of gears in same ratio as a basic level. It is possible to fill this area by trial in 2 ways:

1) vertical classification,

2) horizontal classification.

3.2 Vertical classification

The level of test according to vertical classification is divided in sequence according to speed percentage use. It means, that control program give command to gear speed degree 5 and then 4, 1, 2, and 3 as the last one. It is because all gear mechanism elements would be follow-up from the speed degree which use is the smallest. We have the biggest chance, that we verify biggest number of gear mechanism elements. Mathematic total number of gear [z.sub.uV] in vertical classification, is expressed by relation:

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (2)

Where:

[n.sub.1]-[n.sub.5]--number of gear in u-level,

u--dividing level of max. number of gear,

[z.sub.1i]-[z.sub.5i]--number of gear of individual speed degrees.

Vertical classification is risky, because rest parts of gear mechanism will stay untested for example by testing 4 speed degree by failure. This negative solves trial according horizontal classification.

3.3 Horizontal classification

The test of gear mechanism elements by horizontal classification is possible to describe by a graph. All speed degrees gearing are in phase one. After that, control system gives command to test control mechanism from 4 speed degree. Test till 3 speed degrees is done the same way. It is gear separately from neutral position. We can mathematically describe the number of gears [Z.sub.uH] by horizontal classification test like this:

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (3)

Where:

[n.sub.1]-[n.sub.5]--number of gear in u-level,

u--dividing level of max. number of gear,

[z.sub.1i]-[z.sub.5i]--number of gear of individual speed degrees.

Cycle is repeating after one level of test is finished according to proposed method.

Slovak technical norms do not contain gear mechanism test method of car. That's why a space is given to this part, which will be needed to improve according to reached knowledge by test realisation.

4. CONCLUSION

To know the technical, running parameters and running conditions present the basis for evaluation, formulation of the parameters assurance of the technical level, running quality and car reliability or its components. It is important to know them in the operating mode, dynamic stress, the way of operating and use during running.

Quality requirements are increasing also requirements to function models laboratory testing, their parts, prototypes and their new components (Javorek et al., 2000). This comes out of facts. Practise in foreign countries showed, and it should be relevant, that it is profitable to sub.ect the car problem parts to further development and research. The contribution is aimed at increasing the quality level not only of the final product, but also of the time development of the car and its accessories automation testing.

Acknowledgements: The contribution was elaborated within VEGA No.1/0421/08 "Research of possible applications of non-metal and composite materials by the action members production in the production technology" carried out at Trencin Univerzity of A. Dubcek in Trencin together with related university workplaces and VEGA No. 1/0582/08 "Generalized convergence types in fuzzy environment".

5. REFERENCES

Cernecky, J.; Pivarciova,.; Dubovska, R. (2003). Holografi and her technikal aplications, Radom--Pol'sko, ISBN 80-2564-36-07, pp. 283-289

Javorek, E.; Nascak, E.; Oswald, J. (2000). Monitoring proceeding digging, Stary Smokovec, ISBN 458-235-36-5 page 87-92

Stollmann, V.; (2001). Automatization / Robotics in theory and practice, TU SjF Kosice, ISBN 673-569-364-5, page183-186.

Stollmann, V.; (2006). Progress forest techniques, In: OPTIROB 2006 : first international conference Optimization of the robots and manipulators / ed. Adrian Olaru, Mihai Stanciu, Editura Bren, Bucuresti, ISBN 973-648-572-2. --page 249-255.

Suriansky, J.; Nascak, L. (2000). Measures systems with computer, TU Zvolen, ISBN 80-228-1017-7, pages 79