Research concerning the improvement of bearings quality and performances using automatic systems.

Cristea, Luciana

1. INTRODUCTION

The new idea of products' quality insurance as well the control effectiveness lay down the necessity of a strong interaction and integration among different branches of engineering. The bearing industry achieved in our country special results in the automatic inspection devices field.

The currently used automatic drive systems are manufactured for concrete service and are equipped with elementary components.

The author aimed the implementation of the newest measuring and analysis methods, essential in quality setting and insurance for bearings as main mechanic elements in the automotive industry.

The dimensional inspection automatisation is one of the present basic requirements concerning the upgrading and the retechnologizing of the manufacturing systems in all industrial fields.

The goal that the modern production system must achieve is the production with expected quality and characteristics, as well as small expenses. That tendency is visible on production systems that modified their own internal structure as well as their activities as a series of procedures aimed at defining new production systems with high performances. This task requires high flexibility and modularization in production planning and manufacturing.

The domain of the automat inspection can be considered in integral field including the classical domains of the mechanical, electronic, and computer science engineering. Bearings' production, due to the major economic implications, imposes a permanent improvement of the quality conditions, which leads to the necessity of assuring superior performances related to quality standards. As an integrated field, the automatic inspection devices includes the classic mechanic engineering, electronics and computer field in designing, control and evaluation for these systems (David 2005).

The design of improved control systems for the control automatic device has taken into account the following issues: the configuration of an automatic device with a certain number of mechanic modules--for supplying, distribution, sorting, etc, depending on the user's needs; it makes possible the checking of a larger product range from the same class or similar ones; it makes possible the checking according to one single parameter or a multi-parameter one, with many sorting possibilities of the codes, such as, the classification and the sorting in N dimensional classes according to the control criteria.

Special attention is dedicated to the analyses of dimensional control technology and product characteristics in order to segment the parts into homogenous groups of products with similarly technological characteristics based on concept of group technology.

2. EXPERIMENTAL ASPECTS

In designing the process, we emphasize that the modular control station could be organized as follows:

* All modularly and flexibly organized devices;

* Modular device designed in the most propitious way for each families of parts;

* Measuring and automation checked by an electric computer controlled device;

* High accuracy of operating;

* Interchangeable modulus;

* Different measuring and control transducers and sensors to be used;

* High productivity and efficiency.

All modular devices are defined in order to execute the control operations in correlation with all parts in group (Balachandra, 2002). In view of modulating and assuring a better flexibility and to estimate with better precision the results, the installation (fig. 1) has been designed under modular form.

The mechanical system and measurement unit of the test apparatus were designed to correlate the influential factors of parts assortment with measuring and control equipments. This system is based on client--server concept.

The user has the possibility to input data concerning his/her own application (part, measuring and process characteristics). After that, the main menu of the system works with data bases of parts, measuring and automation process, modular device projects and gives the process results for the most propitious dimensional control structure (Vetter 1994).

The automatic point allows both the measurements of heights and diameters and form deviations under both static and dynamic conditions.

The interactive work between user and server assures the possibility for varied analysis and changes of the inputs. In designing the process, we emphasize that the modular control station could be organized as follows: All modularly and flexibly organized devices;

Modular device designed in the most propitious way for each families of parts; Measuring and automation checked by an electric computer controlled device; High accuracy of operating; Interchangeable modulus; Different measuring and control transducers and sensors to be used; High productivity and efficiency (Alciatore & Histand 2005).

Figure 2 presents the block chart of this dimensional control automatic system. All modular devices are defined in order to execute the inspection operations in correlation with all parts in group.

The control point is made up of the following modules: base plate that is mounted on all the functional modules of the installation; test indicators support; interior attachment module; superior measurement module.

[FIGURE 1 OMITTED]

The point is made up of modules disposed on a base plate provided with holes and milled keyway so as to be used for all the modules. Under the base plate there are mounted the dies chasers for fixing the pieces from the inside. The indicators are designed in order to be used for measuring a large range of diameters. In order to measure the pieces' height, the control point is provided with a mobile bar that supports the indicators; a pneumatic cylinder activates the bar (Fredic, 2007). The control point may determine the controlled parameters in fixed points imposed by the control procedure but it can also assure a continuous regulation by rotating the piece in the control point. The rotating movement is determined by the rotating manner at the moment the measurement device comes into contact with the presser roller. The electronic modular systems of decision are made up of association specific to the control theme within independent modules or deification integrates designated for feed, measurement, operating and dimensional classification. For an optimal selection and configuration of the modules in automatic dimensional control systems, our team generated a special soft. We consider that the interactive design process assures the most propitious structures and realize performing control systems allowing a suitable flexibility degree in the configuration of control automatic devices in modulated systems.

[FIGURE 2 OMITTED]

This solution is achieved and tested during this first step of the project.

3. CONCLUSION

In the bearing production, performing a complete control, of high precision and productivity, stands for an essential characteristic, constitutes an essential characteristic, an indispensable factor of the scientific management of the fabrication process, as well as in maintaining and raising the product quality at a level corresponding to the requirements. Through the research carried out, there has been aimed at a particularly modern approach of the automatic control systems and at the implementation of the latest methods of measurement and analysis necessary for setting and ensuring the quality of bearings as essential mechanical elements in the framework of automotive industry. In the most quality problems during the manufacturing process, the solution has been set up accordingly to the multi-criteria analysis concerning: the necessary measuring accuracy for the tolerance size of the checked parameter, taking into account the increased uncertainty of a sufficient measuring accuracy on the acceptance-rejection decision with the respective involvement; the cost of the checking on a minimal reasonable level; the presentation way of the information raised from the measuring process, in order to reach the right shape at the right moment, necessary for different decisional factors which follow the evolution of the operating process to be stocked as an evidence of the achieved quality when necessary.

4. REFERENCES

Balachandra, R. (2002). Modular Design and Technological Innovation, Report 2002-0, Information Storage Industry Centre, Univ. of California.

Fredic, R. (2007). Towards a Methodology for Integrated Design of Mechatronic Servo Systems. In Doctoral thesis, Royal Institute of Technology, ISSN 1400-1179, Stockholm.

David G. (2005). Introduction to Mechatronics and Measurement Systems, McGraw-Hill Science/ Engineering Math; 3 edition, 2.

Vetter, G.(1994) The Dosing Handbook, Vulkan--Verlag, Essen.

Alciatore, G. & Histand, B. (2005), Introduction to Mechatronics and Measurement Systems, McGraw-Hill Science /Engineering /Math; 3 edition, 2005. http://www.tga.gov.au/devices/fs-sudman.htm, Accessed on: 2008-08-10