Piotr Jabłoński

A Simulative Study Approach for Improving the Efficiency of Production Process of Floorboard Middle Layer

The subject of this paper is the simulation study into the improvement of the production process of floorboard middle layer. The object of our interest in the manufacturing process of wooden floorboard which consists of three layers: lower—made of softwood pieces glued together; middle—in a form a module, made of softwood slats and plywood, and hardwood upper layer. The process improvement involved a better use of raw materials in the form of plats (of variable dimension groups) by reducing losses caused by defects such as wane and knots. A simulation model of the manufacturing process was created by using DES software. Thanks to that model, buffers size and a performance of the designed systems including their anticipated breakdowns were estimated. As a result of the study, a concept of the entire production system meeting the requested production capacity and material efficiency was devised.

New Method of Machining Teeth on Unspecialised Machine Tools

In the present work, the authors describe elaborated method of machining teeth with the use of unspecialized machine tools. In the first part of the work the need to develop such a method has been shown and the drawbacks of the known methods have been indicated. Further part of the work describes the process of mathematical modelling the purpose of which was to determine the tool paths during machining. Next, the kinetics of teeth machining with the use of a universal CNC milling centre is presented. Further on, the operation of the algorithm, the user’s interface of the elaborated software and the parameters influencing the machining process have been shown. In the final part of the work, the results of examination of the obtained details have been shown on a gear wheel as an example. The origin of machining errors and their significance has been discussed. In conclusions, summary of obtained results is presented. In last paragraphs, authors discuss machining accuracy of developed method, and application possibilities of described method are emphasised as well. Performed verification proved that developed method is capable of machining gears of quality comparable with these machined with specialised equipment.

Case Study of Thermal Stress Distribution Within Coating Applied on Aluminum Plain Clutch Plate by Thermal Spray Coating Technique

In this paper, information about the durability of friction clutches under high heat conditions was described. As a way to extend their life and performance, thermal spray coating method is proposed. Process of modeling and conducting simulation in FEA (finite element analysis) environment was described. The thermal stress distribution in coating system in relation to the thickness of applied coating was investigated. Conducted simulation allowed to obtain data that presented strong correlation between coating thickness and both maximum value of Huber-Mises reduced stress and stress distribution characteristics within coating. Collected data allowed to evaluate the possibility of application of such coating on an aluminum plain clutch plate that works under high heat and dry conditions. Presented research has proven that design of such coating should especially cosnider coating thickness and thermal stress condiitons, as these factors may have strong influence on relibilty of cluth plates.

Studies of Geometric Accuracy of Polygons Machined by Polygonal Turning Technique

In this paper, characterization of shape and dimensional accuracy of polygons manufactured by polygonal turning were investigated. The theoretical value of maximum value of outline error was calculated and compared with real sample shape deviation. The data obtained from geometrical measurement of manufactured samples, geometrical characteristics, allowed to evaluate the influence of cutting parameters on machined part accuracy.

Modelling of a contact pressure distribution caused by assembly errors in a spur gear transmission

Following paper presents development and results of finite element structural simulations prepared in order to estimate contact pressure distribution on teeth flanks of gear transmission caused by assembly errors. In first paragraphs, importance of alignment precision of gear transmission components is described. As well, influence of machining and assembly errors on spur gear transmission was introduced. In last part of introduction, innovations in spur gear transmissions assembly processes were described. Process of finite element analysis preparation was presented. Preparation of FEA included development of geometrical model, boundary conditions, discretization of model and definition of external loads. Results of conducted simulations was presented. Especially, contact pressure distribution irregularities caused by misalignment of shafts were examined Obtained data covered correlations between both direction and magnitude of assembly errors with contact stress distribution along tooth length. Conducted tests proved that in case of great-module geared transmission, shaft misalignments in plane which includes gears axes has far lesser influence on contact stress distribution than misalignments in perpendicular direction.

Comparison contact and thermal imaging methods measure the temperatures of the turning blades during cutting

The paper presents a method of measuring the temperature during cutting and its impact on the machining process. The influence of temperature on the intensity of the cutting tool wear cutting and durability. Shows the measuring position, the materials used and the cutting tool. We present the results of the processing parameters, during which the measurements are made. This paper presents methods for measuring the temperature of the blade using a thermocouple and methods of radiation. It lists the advantages and disadvantages of each method.

Structural FEM Analysis of Thermal Sprayed Coatings Under Conditions of Contact Pressure and High Temperature

State of art in the field of wear resistance indicate that, coatings produced with thermal spray methods, can significantly contribute to increase wear rate under conditions of wide range of sliding speeds and varying temperature values. In the beginning of this paper mechanical properties, manufacturing technology and possible applications of thermal sprayed coatings were reviewed. Mechanical properties for selected MMC (metal-matrix composites) materials applied for such coatings were introduced. Determining both stress and deformations of HVOF anti-wear coatings was necessary in order to estimate possible use of these coatings in application on machine parts exposed to high contact pressure and increased temperature. As well, relationship between different materials participation and mechanical properties of produced coatings were mentioned. Analysis method, model and boundary conditions were stated as method of experiment. Numerous structural FEM analysis were performed in order to determine stress and deformations in model samples under conditions of contact pressure and thermal conditions. High temperature was applied in prepared simulations to verify stress and deformation of samples caused by difference in base material and coating coefficient of thermal expansion. 3D structural simulations were conducted, in order to verify stress in different sections. Finite elements size and shape were optimized for obtaining possible short time of both mesh generation and solving of numerical problems. Contact pressure conditions were assumed as same for all simulations, for increasing result comparison possibilities. Analyses were performed for different geometry of samples, differing in coating thickness and surface curvature. Simulations of coatings on both round and flat surfaces were conducted in order to designate influence of surface curvature on coating stress under conditions of contact pressure and high temperature. Results of performed simulations were presented, including detailed information about stress in various direction, deformations and shear stress in area between base material and coating. Correlations between results and geometrical parameters of model were presented, especially including curvature and thickens of coating. Discussion of obtained results and recorded correlations was presented in last paragraphs of this paper. Authors find obtained results as useful initial data in further research on field of thermal sprayed coating application on machine parts exposed to high contact pressures.

Modelling of spur gear cutting kinematics for multipurpose milling center

This paper describes process of kinematics modelling for new method of gears cutting with milling center. Need for usage of mufti-purpose machines and tools in gear cutting is described. Known methods of gear cutting with machining centers are presented. Disadvantages and problem with known methods are introduced, as well need for new method is mentioned. Preparation of kinematical model of new method of gear cutting is followed by estimation of theoretical roughness of tooth flank. In last paragraphs requirements for machines and tools prepared for application of this method are discussed, as well technological characteristics of this method is presented.

Temperature measurements of turning with WCCo-cBN composite cutting tools Thermographic and contact methods

This paper describes measurement methods of temperature machining with WCCo-cBN composite cutting tools. Both contact and thermographic methods of cutting temperature measurements have been described and compared. As well, methodology of emissivity evaluation of cutting tools materials has been mentioned. This paper also covers influence of antiwear TiAlN PVD coating on cutting temperature in reference to machining with uncoated tools.