Journal PROCEEDINGS IN MANUFACTURING SYSTEMS |
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ISSN 2343–7472 ISSN-L 2067–9238 |
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Journal PROCEEDINGS IN MANUFACTURING SYSTEMS
□ Volume 8, Issue 4, 2013
Contents · Florina CHISCOP, Catalina ENACHE, Marius CHISCOP,
Cristian Eugen STOICA, Study for zero breakdowns and
productivity increase · Florian LOTTERSBERGER, Norbert HAFNER, Dirk JODIN, · Corina CONSTANTIN, George CONSTANTIN Empirical model of the cutting
forces in milling · Josef SEDLÁK, Zuzana FIŠEROVÁ, Josef CHLADIL, Oskar ZEMČÍK, Jiří DVOŘÁČEK, The influence of lubricants on the
durability of roller bearings · Nicolae BOIAN, Marioara Adriana BOIAN, The diagnosis of financial resources of small and midle size enterprises (SME) · Anişoara CORĂBIERU, Ştefan VELICU, Petrică CORĂBIERU, Dan Dragoş VASILESCU, · Tiberiu DOBRESCU, Nicoleta Elisabeta PASCU, Aurel Florin ARION, Improving the slicing process
characteristic parameters · Sorin Mihai CROITORU, Adrian Ion PACIOGA, · Matúš KOŠINÁR, Ivan KURIC, Cristina MOHORA, Innovative method for measurement of geometric accuracy of machine tool · Emil UDUP, Claudiu-Florinel BÎŞU, Miron ZAPCIU, Numerical
evaluation of radial deformation of main spindle bearings STUDY FOR ZERO
BREAKDOWNS AND PRODUCTIVITY INCREASE 1) PhD, Lecturer, Department
of Machines and Manufacturing Systems, University “POLITEHNICA” of Bucharest,
Romania 2) PhD Student,
Assistant, Department of Engineering Graphics and Industrial Design,
University “POLITEHNICA” of Bucharest, Romania 3) Student,
Department of Machines and Manufacturing Systems, University “POLITEHNICA” of
Bucharest, Romania 4) PhD Student, Department of Machines and Manufacturing Systems, University “POLITEHNICA” of Bucharest, Romania Abstract: Ensuring a rational
production structure and design should be a priority for anyone starting a
manufacturing architecture. This action can take place in two different
periods of time: when designing the manufacturing architecture or when the
manufacturing architecture is functional depending on products range,
manufacturing technologies, production or labour organization. The main focus
of this paper is to optimise an assembly manufacturing architecture with the
purpose of productivity increase. The optimisation process is carried out on
a vertical refrigerators assembly line from ARCTIC Company. Our case study is
based on identifying and eliminating mechanical breakdowns that occur in the
assembly line and negatively influence the productivity rates. Another
important factor we have to take into consideration is that all
sub-components manufacturing architectures must be levelled as their
productivity rates generate the assembly line productivity. Prior to
optimisation process the entire system was monitored for several months as to
determine the location, number and duration of breakdowns. A number of
solutions were proposed, implemented and validated in order to reduce the
breakdowns number and to achieve the main goal, assembly line productivity
increase. Key words: optimisation, assembly line, mechanical breakdowns, productivity,
cycle time, redesign. EFFICIENCY INDICATORS FOR BENCHMARK AND IMPROVEMENT OF ENERGY EFFICIENCY
ON AUTOMATED MATERIAL FLOW SYSTEMS 1) DI, PhD
candidate, TU Graz, Institute of Logistics Engineering ITL, Graz, Austria 2) Ass.-Prof. DI
Dr.techn., workgroup leader, TU Graz, Institute of Logistics Engineering ITL,
Graz, Austria 3) Univ.-Prof. Dr.-Ing.
habil., head of ITL, TU Graz, Institute of Logistics Engineering ITL, Graz,
Austria
Abstract:
Rising energy costs as well as ecological goals put energy efficiency on a significant level of interest
in most industries. Industrial Logistics operates a huge number of devices
and is characterized by high over all energy consumption. Therefore,
contemporary industrial applications require solutions, which are
(re)designed for high energy efficiency. Currently no general guidelines or standards exist regarding
how energy efficiency is represented in relation to logistic output. The
paper presents the basis for a benchmark system for energy efficiency of
automated in-plant systems. Through the use of Energy Efficiency Indicators
(EEI), efficiency is becoming quantifiable. Comparisons and optimization
tasks on systems can be worked out and evaluated. The focus here is on
conveyor systems for unit loads as they are commonly used for the
transportation of goods in typical logistics applications.
The common structures and basic
operation functions of material flow technology are explained. Starting with
a basic definition of energy efficiency, the mathematical derivation of
Energy Efficiency Indicators is performed by the use of basic characteristics
of conveyor systems. All process steps necessary for determining the energy
efficiency indicators are described. Finally, the validity and clarity of the
EEIs is verified by an application example. Key words: energy efficiency,
industrial logistics, green logistics, benchmark system, efficiency
indicator, material flow system, conveyor system. EMPIRICAL MODEL OF
THE CUTTING FORCES IN MILLING Corina
CONSTANTIN1, George CONSTANTIN2,* 1) Eng.,
PhD, Metallurgical Enterprise for Aeronautics METAV, Bucharest, Romania 2) PhD, Prof, Machine
and Production Systems Department, University “Politehnica“ of Bucharest,
Romania Abstract:
The paper deals with some aspects of modeling milling force as
approach of the integration of multiple modeling in cutting, trying to bring
some original aspects in the empirical approach. Within the experimental
researches several experiments were conducted on the following types of
materials: steel (OLC 45 improved), aluminium alloy (7178), grey cast iron,
and titanium (purity 99%). The experimental research in milling with one
tooth on 180ş were made on a vertical machining centre, FIRST MCV 300, with
three axes, in the laboratory of Machine Tools of Machines and Manufacturing
Systems Department, Engineering and Management of Technological Systems,
University “Politechnica” of Bucharest. The main purpose of the work is to
obtain functions of two variables (cutting depth ap and feed per
tooth fz) for coefficients Kn and Kt
(specific forces) by multiple regression. They are integrated in the
tangential and normal forces Ft and Fn expressions. The
corresponding diagrams of Kn and Kt based on the
mathematical model are compared to those determined by experiments for the
four materials studied. Some comparison charts for Fx and Fy measured and simulated using
the mathematical model established are finally
presented, resulting a good approximation. Several conclusions regarding
modeling are drawn. Key words: milling, milling cutter, specific cutting force components,
tangential cutting force, normal cutting force, cutting force on axis,
measured force, simulated force, comparison. THE INFLUENCE OF LUBRICANTS ON THE DURABILITY OF ROLLER BEARINGS Josef
SEDLÁK 1,*,
Zuzana FIŠEROVÁ2, Josef CHLADIL
3, Oskar
ZEMČÍK 4,
Jiří DVOŘÁČEK 5 1) Eng.,
Ph.D., Lecturer, Faculty of Mechanical Engineering, Institute of
Manufacturing Technology, Brno, Czech Republic 2)
Eng., Ph.D. Student, Faculty of Mechanical Engineering, Institute of
Manufacturing Technology, Brno, Czech Republic 3)
Eng., PhD., Lecturer, Faculty of Mechanical Engineering, Institute of
Manufacturing Technology, Brno, Czech Republic 4)
Eng., Ph.D., Lecturer, Faculty of Mechanical Engineering, Institute of
Manufacturing Technology, Brno, Czech Republic 5)
Eng., Lecturer, Faculty of Mechanical Engineering, Institute of Machine and
Industrial Design, Brno, Czech Republic Abstract:
The paper describes the determination of various factors lubricants that affect the durability of rolling bearings or general rolling contact. Their knowledge is a prerequisite for use in calculating the life of roller bearings from two perspectives. Above all, it will be possible to determine more accurately the durability of rolling bearings or rolling contact with all the economic consequences. The deepening of this information will enable purposeful and controlled increase of rolling bearing durability. Developing a reliable calculation of the life
and durability of roller bearings or other machine nodes with rolling contact
is a long-term global problem that has recently received considerable
attention. The need for more accurate calculations with respect to operating
conditions and desired reliability of machinery and equipment is enforced by
constant rapid pace of development of most industries as well as engineering.
In this situation it is necessary to give designers such calculation methods
and materials that enable optimal use of the properties of roller bearings in
rotating systems of machinery and equipment. Key words: lubricant, durability, lifetime, reliability, roller bearing. THE DIAGNOSIS OF FINANCIAL RESOURCES OF SMALL
AND MIDLE SIZE ENTERPRISES (SME) Nicolae
BOIAN1,*, Marioara Adriana BOIAN2 1)
PhD, Lecturer, department of Engineering Technology and Industrial Management, University
“Transilvania”, Brasov, Romania 2)
Head of financial accounting department, Financial
Investment Company “Transilvania” SA, Brasov, Romania Abstract: The paper presents a method of diagnosing financial resources as part of
small enterprise resources analysis. Starting from general knowledge
regarding financial resources, its diagnose objectives and specific demand
for small and middle size enterprises, the paper synthesizes a model to be
used in diagnose analysis process. According to this model, we establish a
specific method of evaluation for the two criteria: profitability-liquidity
and security-risk. For each of these we present the tables with the financial
indicators. A scoring evaluation method is associated to this diagnose model
in order to facilitate setting the business level in accordance to financial
resources criterion. The score function with variables, coefficients and the
main coordinates of their choice is also presented. Following the diagnose
score, the business level is established and few methods to improve are
suggested. Finally, the paper presents a case study of a company in the field
of tourism. We assessed the business rate and setting the main conclusions
following diagnose. We added the tables containing values of indicators for
the two criteria and also the justification for the choice of coefficients
significance and the conventional score assigned for each domain of analysis. The
main conclusions regarding the case study are closing the paper. Key words: financial resources, diagnosis analysis,
profitability, liquidity, security, risk. Researches
on the superficial layers modified of
the vehicles parts and component
parts, by combined processing in liquid and solid phase Anişoara
CORĂBIERU 1, Ştefan VELICU 2,*, Petrică
CORĂBIERU 3, Dan Dragoş VASILESCU 3 1)
Lecturer., PhD, Technical University "Gheorghe Asachi" of Iasi,
Romania 2)
Prof., PhD, Polytechnic University of Bucharest, Romania 3)
Scientific Researcher II, SC Procomimpex of Iasi, Romania Abstract: The paper
presents the technological aspects of processing combined liquid and solid
phase. Combined treatment goal is to get parts and automotive components by
surface modified. Technological
aspects analyzed include: the technological principle, experimental process
flow analysis, interpretation of preliminary results. Novelty consists in obtaining superficial hardened layers of the vehicles parts
by the implementation of the processing technologies combined liquid and
solid having the following main phases: Phase 1 –superficial micro-alloying directly in the liquid
phase, achieved by the interaction of the liquid steel with the layers
deposited on the mould walls. The successive layers deposited on the mould walls have been obtained using
a paste having as base the hardening mixture with the composition of 40%
metallic powders and 60% carburizing powders; Phase 2 –hardening thermal processing id made in an induction
heating installation using treatment cycle-diagrams previously established
depending on the base material of the vehicle part and on the composition and
structure of the superficial layers obtained following the superficial
micro-alloying directly in the liquid. Phase 3 – final heat treatment, using a variant depending on the
chemical composition of the base material (vehicle part core), composition
and structure of the superficial layers and the real stress and service
conditions of the vehicle part. Key words: researches, superficial layers, combined
processing. IMPROVING THE SLICING PROCESS CHARACTERISTIC PARAMETERS Tiberiu
DOBRESCU1,*, Nicoleta Elisabeta PASCU2, Aurel Florin
ARION3 1) Assoc.
Prof., PhD, Machine and Manufacturing Systems Dpt., University “Politehnica”
of Bucharest, Romania 2) Lecturer, PhD, Engineering Graphics and Industrial Design
Dpt., University “Politehnica” of Bucharest, Romania 3)
Assistant Prof., Engineering Graphics and Industrial Design Dpt., University “Politehnica” of Bucharest, Romania Abstract:
Although
improvements in wafering techniques have produced great saving in device
manufacture, further advances in both wafer productivity and quality can be
achieved by a systems approach to the slicing operation. An ID blade is a bonded abrasive grinding wheel whitch cuts a deep,
narrow slot in the material. In the case of cutting silicon wafers, the major
objective are to make a perfectly stright cut, to remove material fast, and
to minimize subsurface wafer damage. With impetus from the semiconductor
industry, the I.D. diamond saw blade was developed to reduce kerf losses when
slicing these expensive material. This paper
presents experimental results obtained to optimize the characteristic
parameters of the slicing process of hard and brittle materials (silicon,
germanium, ceramic a.s.o.) used in the electronics industry. Experimental
data are used to optimize the slicing process of brittle materials (silicon,
germanium, ceramic, a.s.o.) to obtain some wafers of high shape and
dimensional accuracy such as the resulting wafers require a shorter
processing time through the super- finishing process. Key words: slicing, I.D. cutting, I.D. diamond wheels, silicon
wafer, productivity, quality. TESTING TITANIUM IMPLANTS Sorin
Mihai CROITORU1,*,
Adrian Ion PACIOGA2 1)
Assoc. Prof., PhD, Machines and Manufacturing Systems Dept., University
“Politehnica” of Bucharest, Romania 1)
Senior Researcher, National Institute for Research and Development in
Mechatronics and Measurement Technique of Bucharest, Romania Abstract:
Dental and orthopaedic implants are supposed to be tested from medical
and/or engineering points of view. This paper presents some engineering
experimental research the authors made, related to titanium implants produced
by the Romanian manufacturer of dental implants, Tehnomed Impex Co S.A. and
the National Institute for Research and Development in Mechatronics and
Measurement Technique of Bucharest (orthopaedic implants). Part of the
experimental research was performed in the framework of a research contract
financed by Romanian Ministry of Research and Education. The tests related to
torsion resistance after chemical treatment of the implant were performed in
order to see if the implant has the same (or at least enough) resistance even
if its wall thickness is diminished after chemical treatment and its
surface’s micro geometry is modified. In this case the implants have enough
resistance compared to the non treated implants, but the micro geometry has
lower quality because of the chemical attack. Tests related to the
crystallographic structure of the implant’s material compared the methods of
obtaining the implant: rolled bar and rapid prototyping laser sintered bar.
In this case the rapid prototyping laser sintered implant has a more compact
crystallographic structure, but the cost is greater. Key words: titanium implant, torsion, crystallographic
structure, rolled bar, rapid prototyping. INNOVATIVE METHOD FOR MEASUREMENT OF GEOMETRIC ACCURACY OF MACHINE
TOOL Matúš
KOŠINÁR1,*, Ivan KURIC2, Cristina MOHORA3 1) Eng.,
PhD Researcher, Department of Automation and Production Systems, University
of Žilina, Žilina, Slovak Republic 2)
Prof., PhD, Head of department, Department of Automation and
Production Systems, University of Žilina, Žilina, Slovak Republic 3)
Prof., PhD, Department Machines and
Production Systems, University “Politehnica” of Bucharest, Bucharest, Romania
Abstract:
The paper presents an innovative method of data processing with the
measurement device – Ballbar QC20W. The program for data transformation was
created in Visual Basic.NET and it uses Fourier transformation for spectral
analysis of measured profile. The paper presents the measuring method of CNC
machine tools using Ballbar QC20W. There is a strong connection between the
qualitative parameters of machine tools and the qualitative ones of the
products (tolerances, roughness, etc.). It is very important to hold the
stability of qualitative parameters of products as a key factor of production
quality. The accuracy machine tools evaluation and prediction are of high
interest and therefore is also importance to evaluate the accuracy of machine
tools and make prediction of possible accuracy. How to detect the accuracy of
CNC machine tools, various industries are becoming the user acceptance and maintenance
of CNC machine tools much attention to problems. The paper deals about aspects of
diagnostic accuracies CNC machine tool as well as with the possibilities of
measuring methods and CNC machine tools using multi-parametric diagnostics.
Main part evaluates possibility the geometric accuracy of CNC machine tool by
specialize developed software’s for compared with a direct (Ballbar QC20) and
indirect (Talyrond73) method of measurements. Key words: Ballbar QC20-W, geometric accuracy, data transformation, direct measurement method. NUMERICAL EVALUATION OF RADIAL DEFORMATION OF MAIN SPINDLE BEARINGS Emil UDUP1,
Claudiu-Florinel BÎŞU2,*, Miron ZAPCIU2 1)Institute National of Physics and Nuclear Engineering - Horia Hulubei, Magurele, Ilfov, Romania 2)Lecturer, PhD, Machines and Systems of Production
Department, University Politehnica of Bucharest, Bucharest, Romania 3) Professor, PhD, Machines and Systems of Production
Department, University Politehnica of Bucharest, Bucharest, Romania Abstract:
The paper presents a study on the heat generated by the bearings of a
certain type of main spindle assembly, along with the influence of the
generated temperature on the Z-Y radial deformations employing numerical
simulations as per the finite element method. Moreover, the mentioned numerical
simulations have also been subsequently extended to the spindle assembly
outfitted with a cooling system on the ball bearing location under the
housing. The maximum temperature recorded by numerical simulations on the
rear bearing was 51.2 şC while the temperature on the front bearing was 48.7
şC. After having inserted the cooling system, the on the rear bearing
temperature decreased to 20.4şC and on the front bearing the temperature
decreased to 23.4 şC. Besides, the radial deformation caused by the increase
of temperature was 3 µm at a maximum temperature of 23.4 şC, and on the rear
bearings it was 3.4 µm at a maximum temperature of 20.4 0C. Key words: spindle, bearings, thermal distribution, radial deformation, radial clearance. Electronic mail: orgcom@icmas.eu / |
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