Tibor Krenický

Diagnostic and Experimental Valuation on Progressive Machining Unit

The main effort of each technological process is not only to reduce the costs, but also to reduce the impact on the environment. The technology of abrasive water jet is one of the methods of division and cutting materials with the lowest impact on the environment, since water is the cutting tool, in our case with the addition of an abrasive. The aim of the measurement was the observation (examination) and evaluation of the vibration impact on the technological head in the technology of abrasive water jet when changing the selected technological parameters, namely the feed rate of the technological head. The experiments were carried out on one kind of material - steel HARDOX 500 with a thickness of 10 mm. The impact of the change of the technological head’s feed rate (100, 50, mm/min) on the size of the vibration acceleration amplitude and its frequency were examined. A database was created from the measured vibration values on the technological head and from that database the data was evaluated in selected softwares (LabVIEW, SignalExpress a Microsoft Excel). Graphical dependencies, frequency spectra covers and covers comparison graph were created from which new findings and conclusions were formulated.

Impact of an Excessive Wear of Bearing on the Mechatronic Devices

The article studies, based on the evaluation of the experimental research, effectiveness of independent and combined interaction of selected methods when diagnosing bearing of the mechatronic device in course of 6 months. During this time the general overhaul of the device was carried out, where the measurements, analyses and evaluations were focused on run-in and a shorter after run-in period of the bearing.

Diagnostics of Production Systems Operation Based on Thermal Processes Evaluation

The paper describes a method of prediction values consistently transient events that can be described by a mathematical function. This article focuses on the thermal process. This allows a reasonable time to take appropriate control plot in the desired values of the variables borders. The article contains the results of the simulation and plot comparison of simulation results with the measured value.

Monitoring of Vibrations in the Technology of AWJ

Vibrations of cutting head act as co-factor causing striation of machined work-piece surface, deteriorating its surface quality. In this paper, measurement and evaluation of vibrations generated during the AWJ machining is performed using specialized diagnostic systems. In conclusion, means to minimize influence of cutting-head vibrations on the machined work-piece surface quality are discussed.

Analysis of the Effects of Factors in Relation to Vibration of Technological Head during the Splitting of Construction Steels through Hydro-Abrasive Splitting

The article is focused on the evaluation of the effects of factors of the high-speed hydro-abrasive stream technology during the splitting of construction steels 12 050 and 11 523 through a factor experiment. The experiment examined the effect and significance of two selected factors (type of material and movement speed of the technological head). Measured results are depicted through graphic and numerical relations, based on which new knowledge and recommendations for operators is formulated.

Introduction into the Issue of Water Jet Machining

The ways of searching for methods of increase of efficiency of the process of machining by water jet, of shortening the time inevitable for cutting the individual components with preservation of the quality of the machined area or of reduction of vibration size have not been completed yet. Vice versa, the technology—besides the unlimited assortment of sectile material—disposes a tool without negative effect upon a workpiece or environment and has become a progressive technology in the course of the last years. The infinite or progressive technology of machining by abrasive water jet has gained an importance by adding the abrasive substances. High speed of outflowing water jet with admixture of abrasive allows intensive, economic and ecological machining of almost all industrial materials.

Methodology of Measurement and Examining Methods

The methodology of measurement contains the basic information on performance of measurement of the magnitude of acceleration of technological head vibrations of the selected technical system in the time and frequency domain without the use of abrasive fraction and with the application of narrow fraction of abrasive. The chapter is divided into several basic parts:

Assessment of Measurement of Vibration Sizes

The files of the individual measurements of the structure mentioned in Sect. 5.2.1 contain the assessment of magnitudes of amplitudes of acceleration of the technological head vibrations along with the related frequency spectra under the change of abrasive mass flow, type of abrasive and of narrow fraction of abrasive grain in case of machining of abrasion-resistant steel of K 13—HARDOX 500 type.

Utilization of Knowledge of the Individual Measurements of Vibration Sizes

In general, the technical condition of equipment in operation deteriorates in the course of the time. Deterioration of technical condition represents the consequence of the influence of factors with negative effect. The fundamental factors include increased stress, temperature, dust nuisance and vibrations. Monitoring of the parameters allows obtaining basic objective data inevitable for assessment of the condition of equipment or for correction of negative condition. The operative condition of equipment requires the values to range within the specified limits.

Analysis of Particle Size

Grain materials represent the most frequent form of the solid occurrence, and therefor, the grain composition ranks among basic information characterizing the properties of the substances.