Digitization Methods of Grinding Pins for Technological Process Planning

The paper presents different techniques for digitizing grinding pins and discusses the use of digitalized pins and the results of measurements in technological process planning (TPP), focusing on the challenges of the digital era. It describes the potential of different measuring devices, taking into account the digitization of a real tool shape into virtual 2D and 3D models. The following methods for measuring grinding pins are presented in the study: contact and non-contact coordinate measurements – performed on coordinate measuring machines (CMM); optical measurements on microscopes (i.e. focus-variation technique); optical measurements using tool presetters; optical measurements with measuring arm; laser micrometer measurements; and laser triangulation sensor measurements. Moreover, the use of testers which are applied in contour measurements is analyzed. On the basis of the presented methods, taking into account their possibilities and limitations, we discuss how the obtained digital data can be used in the planning of technological processes.publishedVersio

Comparative analysis of the vibrations of a different kind of engine mounted in the same new motor vehicles

The paper presents the results of tests carried out on two spark-ignition engines: 1.4BZ 90CV CD and 1.4BZ 120CV CD installed in new Fiat Bravo (model 198, version 54A) motor cars. The latter engine model (120CV) was equipped with a supercharging system. The research consisted in comparing engine vibrations measured in specific and representative points. In order to determine the vertical component vibrations, the measurements were performed via a mirror. A PSV-400 laser Doppler vibrometer made by Polytec was used to measure vibration velocities. The vibrometric system directly measures two quantities: displacement and velocity. In the investigated case, vibration velocity is the variable which supplies better diagnostic information. Vibrations were measured for the car standing on its wheels and for the car jacked up to reduce the influence of the car vibration damping systems on the measurement results. The latter are presented in the form of comparative diagrams. Moreover, the fast Fourier transform was used to determine the frequency distribution. Prior to that signal was subjected to conditioning operations using parametric windowing and filtering. Interesting conclusions emerge from the obtained results and on their basis the effect of the drive unit on the behaviour of the car body can be assessed for different engine types and rotational speeds. It is shown that the way in which the engine is mounted affects the vibrations of the car

Ecological assessment of city buses operation with selected fuel stabilizers

W artykule przedstawiono rezultaty z badań emisyjnych autobusów miejskich spełniających normę Euro V (konwencjonalnego z silnikiem o zapłonie samoczynnym) w warunkach drogowych z zastosowaniem wybranych preparatów do paliw i ole-jów. Badania przeprowadzono z wykorzystaniem mobilnej aparatury do pomiaru emisji spalin podczas ruchu pojazdów. Testy wykonywano na odcinku kilkudziesięciu kilometrów w warunkach jazdy miejskiej oraz pozamiejskiej podczas normalnej eksploatacji. Badania takie były wymuszone przez pojawiające się problemy eksploatacyjne (w wyniku pogorszonych właściwości operacyjnych jednostki napędowej), zgłaszane przez użytkowników takich pojazdów. Problemy dotyczą głównie zagadnień regeneracji filtrów cząstek stałych, a jednocześnie są związane ze zwiększonym przebiegowym zużyciem paliwa. Skutkuje to pogorszeniem również parametrów ekologicznych takich pojazdów, a w związku z tym, że są one wykorzystywane główne w aglomeracjach miejskich wpływają na jakość życia mieszkańców. Rozwiązaniem tych zagadnień – według autorów artykułu – może być zastosowanie preparatów do paliw i olejów silnikowych, które pozytywnie wpływają na proces spalania, a jednocześnie dodatkowo oddziałują na polepszenie pracy – stosowanych w takich pojazdach – systemów oczyszczania spalin.The article presents the results of emission research of city buses that meet the Euro V standard (conventional with a compression ignition engine) in road conditions with selected additives for fuels and oils. Tests were carried out using the mobile equipment for measuring the exhaust emissions of vehicles. The research was performed on a stretch of several kilometers in urban and rural driving conditions during normal operation. Such studies were forced by emerging operational problems (as a result of degraded operating characteristics of the drive unit), reported by users of such vehicles. The problem are mainly associated with regeneration of particulate filters and also increased fuel consumption. This results in the deterioration of ecological parameters of the vehicles, and consequently, because they are used in a major urban agglomerations, affects the quality of people life. The solution of these issues – according to the authors of the article – can be application of preparations for fuels and oils, which improve the combustion process, while also affect the improvement of aftertreatment systems operation – used in such vehicles

Vehicle vibration in human health

Fast development of technology over the last decades has contributed to the adverse effects that may affect human health (both physical and mental). Such negative effects may include noise and vibration. These phenomena are accompanied by most of the technological processes. Need for more efficient and productive processes is causing rising trend in intensifying of these phenomena. It is unavoidable to increase efficiency without increasing the operating speed of machinery and equipment. The main goal of this paper is to carry out NVH (noise, vibration and harshness) analysis of engines; compression-ignition engine (diesel) and spark-ignition engine (gasoline) equipped in the same type of vehicle. But purpose is laying on presented methodology, not results of researches (but of course it will be presented too) which often (mainly) is made for failure detections. This paper will also cover influence of the engine mounting on generated acoustic vibrations followed by comparative NVH analysis of states occurring in diesel and gasoline engine. Scope of the work: a) theoretical introduction, b) presentation of vibration measurement (using LDV: Laser Doppler Vibrometry), c) NVH analysis in two types of engines, d) comparison of results, e) conclusions

Testing of internal combustion engines of motorcycles with the use of thermal imaging methods

The internal combustion engine should be rated for the thermal loads that come from different sources. Thermal analysis is important both for design purposes and for evaluating the conditions of its use. Very good results are obtained by a combination of non-invasive measurement techniques, such as research using infrared thermal imaging techniques [3, 11]. The purpose of the study was to determine the engine thermal load by evaluating the average temperature on the outside surface of the engine at many of its points for two selected motorcycle engines with similar displacement capacities. For many reasons, such as ecology, durability, engine strength and thermal performance when heating and cooling are critical. To accomplish this task, a thermographic technique for indirect evaluation has been used, thus creating the possibility of measuring the temperature in a dynamic manner. These are accurate measurements and most importantly do not interfere with the construction of the object under investigation. The engine was tested during operation according to external and load characteristics. As a result of the work, graphs of temperature curves of heating and cooling of the tested engines were compiled. The article presents a methodology for measuring the temperature fields of outer surface engines. The collected material will be used in the future for studying the equable load on the cylinders, and as accurately as possible determine the conditions of movement such as power, revolutions, flow rates, temperatures and pressures

Selected remarks about real driving emissions tests

Nowe procedury badawcze wyznaczania emisji drogowej zanieczyszczeń spalin dla pojazdów osobowych mają wejść w życie w 2017 roku. Od kilku lat Komisja Europejska zajmuje się opracowaniem nowych procedur, których celem jest wykonywanie badań w warunkach drogowych. Ma to na celu określenie rzeczywistych wartości emisji spalin, co nie zawsze odzwierciedla poziom emisji spalin w warunkach laboratoryjnych. Dokładne procedury badawcze emisji zanieczyszczeń w rzeczywistych warunkach ruchu (RDE – Real Driving Emissions) nie zostały jeszcze uchwalone (w odróżnieniu do pojazdów ciężarowych, dla których takie uwarunkowania już funkcjonują), jednakże istnieją propozycje, które obecnie są analizowane przez główne ośrodki badawcze w Europie. Propozycje te różnią się między sobą, m.in. sposobem wyznaczania emisji drogowej zanieczyszczeń, oraz metodyką badań uwzględniającą np. pomiar emisji drogowej węglowodorów. W artykule porównano wyniki emisji spalin uzyskiwane w testach drogowych z wykorzystaniem najnowszych propozycji legislacyjnych odnoszących się do samochodów osobowych. Uzyskane wyniki przedstawiono w odniesieniu do następujących metod pomiarowych: metoda klasyczna wyznaczania emisji drogowej związków szkodliwych – wykorzystuje się wszystkie dane pomiarowe wyznaczając masę związków szkodliwych i przebytą drogę podczas testu; metoda uśredniania okien pomiarowych (MAV – moving average windows), zwana również w literaturze metodą EMROAD, w której wyznacza się okna pomiarowe (na podstawie danych o emisji dwutlenku węgla z testu WLTC) i na ich podstawie wyznacza się emisję drogową w teście RDE; metoda kategoryzacji mocy (Power Binning), zwana w literaturze jako CLEAR – Classification of Emissions from Automobiles in Real driving, wyznacza się emisję spalin na podstawie kategoryzacji mocy podczas testu RDE.New test procedures for determining exhaust emission from passenger vehicles will be introduced in 2017. For several years, the European Commission has been developing new procedures, which aim is to perform tests in road conditions. The purpose is to determine the real value of emissions, which are not always reflected by the level of emissions obtained in the laboratory. Proper and accurate procedures for determining emissions in real traffic conditions (RDE – Real Driving Emissions) have not yet been approved (as opposed to Heavy-Duty Vehicles for which such conditions already exist), but there are proposals that are currently being analyzed by major research centers in Europe. There are many differences between those proposals such as determining road emission or research methodology related to emission measurement of hydrocarbons. The work compares the results of emissions measured in road tests using the latest legislative proposals related to passenger cars. The results are shown in relation to the used measurement method: classic method of determining exhaust emission; uses all measurement data determining the mass of harmful compounds and distance traveled during the test; method of averaging the measuring windows, also in the literature called EMROAD method, which determines the measurement windows (on the basis of carbon dioxide emissions from the WLTC test) and on its basis determines the road emission in RDE test; generalized method of instantaneous power (Power Binning), known in the literature as CLEAR – Classification of Emissions from Automobiles in Real driving, determines road emissions on the basis of generalized instantaneous power during the RDE test

Impact analysis of air humidity on operating parameters of diesel engine

A major problem in the combustion diesel engines is the different distribution of the mixture of air and fuel and also temperatures inside the combustion chamber. It helps the formation of points of the high and low oxygen concentration in the combustion chamber of the engine. In areas with a high concentration of oxygen, the combustion process produces very harmful NOx, and in places with low oxygen concentration, as a result of incomplete fuel combustion particles are created in the form of soot. This not regular distribution of the mixture of air and fuel and temperatures in the combustion chamber affect the limited maximum engine power and efficiency at his every operating cycle. One method for improving the combustion process is feeding into the engine air with high relative humidity. The study was conducted on a chassis dynamometer at the Department of Vehicles Engineering Wroclaw University of Technology. For the purposes of the study determined the external characteristics, including maximum engine power and maximum engine torque at different air relative humidity and quite similar air temperature. Analysis of the results of research shows that high air relative humidity has a positive effect on the work parameters of the diesel engine