MM Science Journal, March 2022

March 2022

ROBOTIC GRIPPER ACTUATED USING THE SHAPE MEMORY ALLOY ACTUATORS

MICHAL KELEMEN, TATIANA KELEMENOVA, IVAN VIRGALA, LUBICA MIKOVA, ERIK PRADA, MARTIN VARGA, JAN SEMJON, MAREK SUKOP, RUDOLF JANOS
Keywords: gripper | actuator | shape memory alloy | manipulator | mechanism

The article deals with the design of a gripper for a manipulator. The use of a shape memory alloy actuator, which is excited by heating by means of an electric current, is proposed for driving the gripper jaws. Variant solutions of the gripper kinematics and the final design of the gripper arrangement are solved. A gripper kinematics simulation is created to find a suitable gripper geometry.

USE OF HOLOGRAPHIC INTERFEROMETRY FOR MONITORING HEAT TRANSFER

ELENA PIVARCIOVA
Keywords: heat transfer | wood | holographic interferometry

In the paper is described possibility of holographic interferometry in research of heat transfer above samples. Experiments with utilization of this method enable to explain many of actions going in environment and in phase interface between material and this environment in transport of heat. The presented experiments are aimed at verifying the possibilities of safe thermal loading of wood using with me (…)

EXTRACTION OF METHANE GAS DURING BROWN COAL MINING AND POSSIBILITY OF ITS USAGE

ERIKA SKVAREKOVA, MIROSLAV RIMAR, JAN KIZEK, KATARINA TEPLICKA, MARIAN SOFRANKO, MARTIN LOPUSNIAK
Keywords: coal deposits | extracted mine gas | degassing station | gaseousity of CH4 | cogeneration

Coal mining is still proceeding in some countries today, although EU countries have agreed to move to a carbon-neutral economy by 2050. Mine gases were developed during coalification. The quantity of gas inside the coal deposits depends on the: level of coalification, quantity of colliery tip and on conditions, which have contributed to the keeping of gas inside the coal deposits. Mine gases are endan (…)

AN IMPACT OF THE STEEL-CONCRETE COMPOSITE SUPPORTING STRUCTURE ON THE DYNAMIC PARAMETERS OF THE MACHINING CENTER

DOMINIK HERMANSKY, JIRI MAREK
Keywords: Machine tool | chatter | steel-concrete composite

A self-excited vibration, called “chatter”, is a main limiting factor in chip-forming metal machining. The reduction of machining productivity, worsened machined surface quality and the reduction of lifetime of the machine tool parts, particularly the cutting tool itself, occur as a result of the chatter. There are more ways to suppress this undesired effect of machining. The most common and simplest va (…)

COMPUTER ANALYSIS OF THE TECHNOLOGICAL PROCESS OF A SELECTED COMPONENT'S PLASTIC INJECTION

PETR BARON, MAREK KOCISKO, EDUARD FRANAS
Keywords: computer simulation | plastic injection | polymer | quality prediction.

The article describes an optimization methods analysis in the technological process of plastic injection using the simulation tool Autodesk Moldflow Adviser. The Polyethylene 120J was the material used in production of the plastic part analyzed. Following the simulations, deficiencies affecting the quality of the final part were identified. Modifications were gradually made both in the cover's design an (…)

UTILIZATION OF OPERATIONAL PARAMETERS MONITORING TO ECONOMICAL AND SAFETY DRIVE OF VEHICLES

JINDRICH PAVLU, MARTIN PEXA, JAKUB CEDIK, VLADIMIR JURCA
Keywords: diesel. | rapeseed oil methyl ether | biofules | capacitive probe | driving style of driver

The paper is focused on the issue of measuring the amount of fuel in the tank of truck, construction and agriculture machine. The gradual expansion of of the share of the biocomponent in diesel fuel results in greater measurement errors via the capacitive probe in the fuel tank. The proposed solution, which uses three electrodes leads to increased accuracy in measuring of the amount of fuel in the tank. (…)

DESIGN SOLUTIONS OF THE MECHANICAL PRESSES LEADING TO IMPROVEMENT OF THEIR TECHNICAL PARAMETERS WHILE IMPROVING THEIR ENERGY DEMANDS

MARTIN ZAHALKA, MILAN CECHURA, VACLAV KUBEC
Keywords: press | forming | CAD | Energy Efficiency | press stand

The article states that the significant improvement of technical parameters for mechanical crank presses of the current concept is already very limited. Significant improvements in technical parameters can be made at the cost of changing the design concept. To substantiate this statement, an analysis of the current situation is performed and the possibility of successful improvement of technical paramet (…)

STRESS-STRAIN MEASUREMENT IN HEAVY LIQUID METALS

MICHAL CHOCHOLOUSEK, ZBYNEK SPIRIT, ZDENEK FULIN
Keywords: Heavy liquid metal | strain | extensometer | mechanical properties | testing cell

The mechanical testing in heavy liquid metals is performed in order to obtain information about the influence of the liquid metal on Generation IV candidate construction materials. For testing in heavy liquid metal environment, it is required to test comparably with standards of mechanical testing in air at high temperatures. The paper summarizes the approach to the measurement of mechanical properties (…)

COMPARATIVE STUDIES OF EDM PROCESS CONDUCTIVE LAYER ON SILICON NITRIDE WITH BRASS AND COPPER ELECTRODES

PATITTAR NAKWONG, APIWAT MUTTAMARA
Keywords: electrical discharge machining | Electrode | Silicon Nitride | Brass | Copper

Insulating materials are now subjected to precision electrical discharge machining (EDM) using an assisting electrode method (AEM). The electrode materials usually comprise copper, graphite and copper alloys that have high melting temperature and excellent electrical and thermal conductivity. A brass electrode is known as a humble electrode. Performances of brass and copper pipe electrodes were compared (…)

PREVENTION OF ACCIDENTS AT WORK AND OCCUPATIONAL DISEASES BY IMPLEMENTATION OF ERGONOMICS

PETRA MARKOVA, MARIA HOMOKYOVA, FILIP PRAJ, MILOS CAMBAL
Keywords: work | employee | Ergonomics | occupational injury | occupational disease | work environment factors | costs

The paper deals with the connection between accidents and occupational diseases due to the weak application of ergonomics in business practice. Applying the principles of ergonomics in the day-to-day running of companies in primary prevention makes it possible to prevent the occurrence and exacerbation of difficulties in the musculoskeletal system of the employees concerned, which can ultimately avert t (…)

VERIFICATION OF THE TORQUE GAUGES

TATIANA KELEMENOVA, MICHAL KELEMEN, IVAN VIRGALA, LUBICA MIKOVA, ERIK PRADA, MARTIN VARGA, JAN SEMJON, MAREK SUKOP, RUDOLF JANOS, PETER TULEJA, PETER MARCINKO
Keywords: torque | gauges | etalon | uncertainty | torque wrench

The article deals with the methodology of verification of mechanical and electronic torque gauges. Legislative metrological requirements are set for these gauges and the verification process for these types of gauges is also set. The working standard is used to verify two selected torque gauges and then the suitability of these gauges is assessed. Measurement uncertainties are identified to determine th (…)

COMPARISON OF POROSITY OF CASTS PRODUCED BY HPDC AND VPDC TECHNOLOGIES

STEFAN GASPAR, JAN MAJERNIK, MIROSLAW TUPAJ, MARTIN PODARIL
Keywords: Vacuum Pressure Die Casting (VPDC) | High Pressure Die Casting (HPDC) | porosity | Gas Entrapment | Zinc Alloys

The die casting technology enables the production of complex casts with good mechanical properties and high repeatability of the production within narrow tolerance limits. However, the casts are showing signs of porosity to some extent, which may reduce their mechanical and qualitative properties. The presented article solves the problem of reducing the porosity f the high pressure die casts by vacuumin (…)

ROBOTIC ARM DESIGN, DEVELOPMENT AND CONTROL FOR PRINTING CEMENT MIXTURES

JOSEF BROUSEK, TOMAS PETR, LEOS BERAN, TOMAS MYSLIVEC, DANIEL KAJZR, ROBERT VOZENILEK, MARTIN DIBLIK, LAURI RISTOLAINEN
Keywords: robotic arm design | robot design | generative design | printing cement mixtures | concrete printing | 3D printing

New innovative approaches for building construction are being developed around the world. One of these is printing cement mixtures for which various machines are now being developed. This paper deals with the design of an experimental robotic arm for research into cement mixture printing. A generative design approach was used and discussed in its development. The results describe the solutions obtained (…)

THERMAL-DEFORMATION BEHAVIOR OF THE COMPOSITE MATERIAL BED

DOMINIK HERMANSKY
Keywords: Machine tool | machine tool bed | thermal deformation | steel-concrete composite

The thermal stability of the machining centers plays a major role in ensuring the production repeatability. All machine tools producers take various steps to ensure it. One of the ways to permanently maintain and stabilize the behavior of the machine tool is the use of active cooling and the choice of appropriate material of which the individual parts of the supporting system are made. In most cases, ma (…)

AUTOMATION OF PARTIAL TASKS IN THE DESIGN OF ROBOTIC ARMS

ZDENEK ZEMAN, MILAN MIHOLA, JIRI SUDER, ADAM BOLESLAVSKY
Keywords: automation | Equipment design | robotics | mechatronics

The design of robotic arms is a demanding process, especially in terms of the demands placed on developers' knowledge and experience and the time required for the design. Therefore, the development aimed to create procedures for possible automation of some of the individual tasks of the robotic arm design process, which are further applied in the development of a software tool for the automation of part (…)