Showing papers in "Cirp Annals-manufacturing Technology in 1993"
TL;DR: In this paper, the various possible routes to achieve clean machining processes are analysed and discussed and it is shown that a new and innovative approach is essential within the framework of an environmentally oriented management system and the relevant networks for data provision and analysis.
Abstract: Summary Present day machining processes are not clean. Current trends in the manufacturing world indicate that this situation will not be acceptable in the future and that extensive research and development work is essential in order to meet the future requirements of legislation. In this paper, the various possible routes to achieve clean machining processes are analysed and discussed. It is shown that the conventional approach has its limitations and that a new and innovative approach is essential within the framework of an environmentally oriented management system and the relevant networks for data provision and analysis. Processes have to be subjected to fine analysis giving deiailed consideration to the various inputs and outputs. Combined processes, alternative processes, new technologies, energy requirements etc. have to be evaluated from the environmental perspective. A first approach to the strategy required to answer the many questions which arise in relation to clean machining processes and to an integrated environmental protection policy is presented and discussed.
245 citations
TL;DR: In this article, the effect of single crystal diamond tool edge geometry on the resulting cutting and thrust forces and specific energy in the ultraprecision orthogonal flycutting of Te-Cu was made.
Abstract: Summary An experimental study of the effect of single crystal diamond tool edge geometry on the resulting cutting and thrust forces and specific energy in the ultraprecision orthogonal flycutting of Te-Cu was made. The effects of both the nominal rake angle and tool edge profile were investigated over uncut chip thicknesses from 20μm down to 10 nm. Characterization of the tool edge was performed with the use of atomic force microscopy. Both the nominal rake angle and tool edge profile were found to have significant effects on he resulting forces and energies.
182 citations
TL;DR: In this article, the root cause of high frequency, saw toothed chip formation was found to be periodic gross shear fracture extending from the free surface of the chip toward the tool tip and not adiabatic shear as commonly believed.
Abstract: With the availability of polycrystalline cubic boron nitride (PCBN) it is possible to machine very hard gears, etc. at speeds of (60–150 m/min = 200–500 fpm). When this is done using PCBN tools in face milling, Chip formation is of a cyclic saw toothed type. This type of chip formation is reviewed in relation to other types of cylic and noncyclic chip formation. The root cause of high frequency, saw toothed chip formation is found to be periodic gross shear fracture extending from the free surface of the chip toward the tool tip and not adiabatic shear as commonly believed.
181 citations
TL;DR: In this paper, a preliminary method for evaluating environmental consequences containing the major environmental effects is presented, which quantifies the term "environmental friendly" so it can be used as a “yardstick” in evaluating different technical solutions.
Abstract: Summary The Life cycle concept will become the backbone in a new industrial culture named sustainable production. Sustainability means that products are designed for their whole life cycle i.e. production, distribution, usage and disposal with minimized (acceptable) influence on the environment, occupational health and use of resources. A key element in this new engineering life cycle approach is a method/tool to assess and evaluate environmental, occupational health and resource consequences in all life cycle phases at the product development stage. In this paper a preliminary method for evaluating environmental consequences containing the major environmental effects is presented. The method outlined quantifies the term “environmental friendly” so it can be used as a “yardstick” in evaluating different technical solutions. The complex problems in the final design decisions are discussed and future perspectives outlined.
173 citations
TL;DR: The primitive building element in 3D printing is a spherical ensemble of powder particles held together by one droplet of binder as mentioned in this paper, which is used to determine the dimensional control and surface finish of 3D printed parts.
Abstract: Three Dimensional Printing is a process for creating parts directly from a computer model. 3D Printing builds parts in layers by spreading a layer of powder and then selectively joining the powder in the layer by ink-jet printing of a binder material. After all layers are printed, the layer loose of powder is removed to reveal the finished part. Application areas include ceramic molds for metal castings, directly printed parts for end-use and for use as tooling, ceramic preforms for metal matrix composites, structural ceramic parts, and others. 3D Printing is a member of a group of layer manufacturing techniques which have the primary distinguishing feature of creating parts by the controlled addition (rather than subtraction) of material. The primitive building element in 3D Printing is a spherical ensemble of powder particles held together by one droplet of binder. Ballistic effects are important in the formation of primitives due to kinetic energy associated with the incoming droplet. Stitching together of droplets forms surfaces and hence determines surface finish. Vertical dimensional control is determined in pan by the compression of powder layers by subsequently applied powder. These physical mechanisms help to determine the dimensional control and surface finish of 3D Printed parts.
152 citations
TL;DR: In this article, the authors present the present situation of the European machine tool industry and the control manufacturers as well, as with the motivation to start with the design of a vendor-neutral open control system.
Abstract: Summary This contribution deals with the present situation of the European machine tool industry and the control manufacturers as well, as with the motivation to start with the design of a vendor-neutral open control system. The problems of configuration and control-internal Communication are discussed and solutions are given. Furthermore, the ESPRIT project OSACA is presented which aims at the specification of vendor-neutral standards for open control systems.
126 citations
TL;DR: In this paper, the cumulative distribution plot on a normal probability graph is used to characterize the texture of a plateau-enhanced cylinder liners for internal combustion engines, and an alternate approach is proposed based on analyzing the cumulative distributions of the normal probability graphs.
Abstract: The plateau honing operation is being widely used for finishing of cylinder liners for internal combustion engines Plateau honing has been shown to significantly reduce the costly running-in period due to the fact that very little further modification of the texture is required once the liner is put into operation In order to better understand, control, and ultimately “engineer” plateau honed surfaces, a comprehensive means of characterizing this texture is required In this paper the techniques currently used are briefly reviewed and an alternate approach is proposed The proposed approach is based on analyzing the cumulative distribution plot on a normal probability graph
118 citations
TL;DR: In this paper, a new methodology called FBS (Function-Behavior-State) modeling is proposed to deal with functional design, and a computer tool to support functional design based on the FBS modeling is described.
Abstract: Summary Although functional design (or conceptual design) is crucial to whole design processes, traditional CAD technology based on geometric modeling does not support this process because of difficulty of dealing with function. This paper proposes a new methodology to deal with function. Called FBS (Function-Behavior-State) modeling, and describes a computer tool to support functional design based on the FBS modeling. Importance and advantages of the FBS modeling is clarified by demonstrating two examples. One is the design of functionally redundant machines and the other is the automatic generation of control software for mechatronics products.
108 citations
TL;DR: In this article, a set of models pertinent for realizing virtual manufacturing environment is induced and discussed in some details as a kernel, where product models represent every artifact which appears during manufacturing, and process models are associated with them to derive their properties and behaviour.
Abstract: Summary For coping with severe requirements for future manufacturing systems, it is effective to model necessary product behaviour and associated manufacturing processes by computer as precisely as possible, and to predict potential problems for product functionality and manufacturability before making real manufacturing. This approach is called as virtual manufacturing. In this paper, a set of models pertinent for realizing virtual manufacturing environment is induced. Among them product and process models are discussed in some details as a kernel. Product models represent every artifact which appears during manufacturing, and process models are associated with them to derive their properties and behaviour. Some examples are given to show the effectiveness of virtual manufacturing.
96 citations
TL;DR: In this article, an integrated process planning model (IPPM) is introduced, which integrates process planning and job shop scheduling by means of distributed approach which is different from current nonlinear and alternative process planning approaches.
Abstract: Summary Functional integration has taken the foreground in the current manufacturing system development. Process planning and job shop scheduling are two main manufacturing functions involved in shop floor activities. An integrated process planning model (IPPM) is introduced in this paper. The two functions (process planning and job shop scheduling) are truly integrated by means of distributed approach which is different from current nonlinear and alternative process planning approaches. In this paper, the two functions are integrated at task stage, while the nonlinear and alternative approaches are taken place at result stage which cannot be considered as real integration but rather interface. The introduced IPPM works in three levels, based on manufacturing resource availability and real time feedback from shop floor, they are pre-planning, pairing planning, and final planning. The IPPM consists of three modules, introduced in detailed in the paper, they are: process planning module, production scheduling module, and decision making module. An example is provided to illustrate the model. This paper is to be considered as a contribution to the research efforts in process planning and integrated manufacturing.
95 citations
TL;DR: In this paper, an intelligent machining center that employs thermal actuators to actively compensate for thermal deformation has been designed, constructed and tested, which incorporates an intelligent controller, force and deformation sensors and fail-safe mechanism to protect against catastrophic failure of the system.
Abstract: An intelligent machining center that employs thermal actuators to actively compensate for thermal deformation has been designed, constructed and tested. The machining center also incorporates an intelligent controller, force and deformation sensors and fail-safe mechanism to protect against catastrophic failure of the system. Both matrix control techniques and neural network approaches to the control of the thermal deformation of the machine structure have been tested. In both cases, the measured maximum thermal deformation was controlled to a level of 10 micrometers, approximately 1/3 the level of the uncontrolled machine.
TL;DR: In this article, the electrical contact between a vibrating feeler and the inner surface of a hole is detected, and the duty cycle of the contact is measured through a controlled scan by a feeler with a constant duty cycle.
Abstract: Summary A new method for measuring inner dimensions of small holes was developed. The electrical contact between a vibrating feeler and the inner surface of a hole is detected, and the duty cycle of the contact is measured. Through a controlled scan by a feeler with a constant duty cycle, data on the ups and downs of the surface profile are obtained. Through the application of this principle, a φ 200μm hole with the depth of 700μm was successfully measured, and geometrical data such as straightness, declination and taper were obtained.
TL;DR: In this paper, the authors introduced how, by applying oil-air minimum quantity lubrication using a new oilair supply, the revolutionary parameter limit was able to be increased to approximately n*dm=1.8*106 mm/min.
Abstract: Summary The operational speed of spindle bearing systems with angular contact ball bearings is limited amongst other factors by the highest permissible rotatory speed of the bearings. The revolution parameter limit of these bearings currently lies at about n*dm= 1.5*106 mm/min if lubricated by the principle of minimum oil quantity. This paper will introduce how, by applying oil-air minimum quantity lubrication using a new oil-air supply, the revolutionary parameter limit was able to be increased to approximately n*dm=1.8*106 mm/min. On the basis of test results it shows how the application of ceramic balls or coasted bearing elements reduces the surface wear under insufficient lubrication conditions and increases the life span of the bearing.
TL;DR: In this article, the application of excimer laser radiation in a multiaxis CNC-micromachining unit with modular design is presented, which can be used to generate microstructures in ceramic and polymer surfaces.
Abstract: Excimer lasers can be used to machine metals, ceramics and polymers. UV radiation with short pulses of several 10 ns and intensities much higher than those of other sources allow machining with minimum thermal influence. The high photon, energy of excimer laser radiation facilitates a direct photolytic interaction with the material. Besides this thermal and pyrolytic interaction mechanisms also appear. Concidering on this, the removal mechanisms of certain materials are discussed. The application of excimer laser radiation in a multiaxis CNC-micromachining unit with modular design is presented. Special features of this micromachining center are the beam handling system with integrated flexible mask and energy control. The workpiece handling and all process parameters are controlled by a host computer with ergonomic user interface. The unit can be used to generate microstructures in ceramic and polymer surfaces. Furthermore, it is possible to produce micromechanical parts of these materials, also in fibre reinforced plastics.
TL;DR: In this paper, three typical colors deep blue, blue, and golden brown were analyzed and found to contain varying amounts of oxide layers consisting of FeO, Fe 2 O 3 and Fe 3 O 4.
Abstract: Summary Carbide inserts of different geometry (SNG, CNMG, CNMG-MG, CPMP, and SPMP) with a variety of coatings [CVD TiN, PVD TiN, CVD (TiCN/TiC/Al 2 O 3 ), CVD (TiCN/TiC) + PVD TiN, CVD TiC, and TiN/Al 2 O 3 , …TiCN] were used to machine AISI 1018 steel at different speeds with and without a coolant. Three typical colors deep blue, blue, and golden brown were analyzed and found to contain varying amounts of oxide layers consisting of FeO, Fe 2 O 3 and Fe 3 O 4 . Chip roots from turning/drilling operations were studied for secondary shear/built-up edge formation, and temperatures calculated and related to chip color. Chip color classification, brightness, surface roughness, waviness, roundness, and chip strain were measured and evaluated.
TL;DR: A machining scenario is a description of a machining process in which the changes of machining states are described in terms of both geometrical and physical characteristics as discussed by the authors, such as geometry of tool-workpiece contact face, cutting force, and machining error.
Abstract: A machining scenario is a description of a machining process in which the changes of machining states are described in terms of both geometrical and physical characteristics of machining processes such as geometry of tool-workpiece contact face, cutting force, and machining error. A machining scenario can be automatically generated by a model based cutting simulation. It provides useful information for pre-process optimization of cutting conditions. on-line adaptive control, and monitoring and diagnosis of abnormal occurrences. This paper describes the data structure of the machining scenario and how it can be utilized for the generation of efficient and reliable machining data and realizing intelligent machining operations. The results of experiments by a prototype system are also described to verify its effectiveness.
TL;DR: In this article, the temperature of cutting grains on the grinding wheel just after cutting is measured using a new type of infrared radiation pyrometer with optical fiber and InAs cell.
Abstract: The temperature of the cutting grains on the grinding wheel just after cutting is measured using a new type of infrared radiation pyrometer with optical fiber and InAs cell. The mean temperature of cutting grains is hardly influenced by the wheel depth of cut or the workpiece speed, but decreases with increase of the wheel speed. The maximum temperature of cutting grains at the cutting point is approximate to the melting point of the work material of steel. The change in the working conditions of cutting grains after every revolution of the wheel is observed.
TL;DR: In this paper, a linear magnetic bearing stage was proposed for X-Y wafer positioning in photolithography stages. But the magnetic bearing performance and resolution were not improved. But an advanced prototype was designed and is currently under construction.
Abstract: Summary This paper describes a linear magnetic bearing stage which controls a suspended object in six degrees of freedom. The intended application is for X-Y wafer positioning in photolithography stages. Magnetic bearings offer superior performance and resolution over existing mechanical X-Y stages. An advanced prototype magnetic bearing stage that improves the ideas verified in the existing stage has been designed and is currently under construction. The paper will also present the advanced stage design methodology used and the reasons for the decisions made.
TL;DR: In this article, an unsupervised neural network is introduced for on-line tool breakage detection in machining using multiple sensors, which performs detection by classifying the measurements either as normal or abnormal.
Abstract: An unsupervised neural network is introduced for on-line tool breakage detection in machining using multiple sensors. This neural network performs detection by classifying the measurements either as normal or abnormal. However, it performs classification by relying only on the normal category, so that it does not need to establish the abnormal category requiring samples of measurements taken at tool breakage. This Single Category-Based Classifier (SCEC) also adapts the prototype values on-line so as to continuously update the normal category, and employs the noise suppression techniques: contrast enhancement and ding, in order to cope with different levels of noise in measurements. The performance of the SCBC is evaluated in turning. Extensive tests were performed which produced six tool breakage cases. Four measurements which were clear indicators of tool breakage in these tests were used as inputs to the SCBC and to two other classifiers utilizing Kohonen's Feature Mapping and Adaptive Resonance Theory (ART2). The results indicate that the SCBC was the only classifier that could detect all of the tool breakages.
TL;DR: The applicability of the plane strain compression test to simulate the flat rolling process is examined analytically and through experiments in this paper, where the authors compare the distributions of stress, strain rate and temperature in the two processes.
Abstract: The applicability of the plane strain compression test to simulate the flat rolling process is examined. analytically and through experiments. The resistance to deformation and the rise of temperature of a 6061-T6 aluminum alloy is determined in plane strain compression. A thermal-mechanical finite element model, developed to analyze both the rolling and compression processes is then introduced. Its ability to calculate the distributions of the variables is substantiated by comparing the time-temperature profiles measured during plane strain compression tests with those predicted by the model. Following next are comparisons of the distributions of stress, strain rate and temperature in the two processes, leading to the conclusion that in general, good similarity among the parameters is observed and that the plane strain compression test gives a reasonable simulation of the flat rolling process, provided the shape factors are comparable.
TL;DR: In this paper, a finite element method (FEM) is used to determine the two-dimensional potential and flux distributions in the electrolyte, in order to estimate surface erosion for a finite time-step.
Abstract: Summary The paper describes a computer package based on the FEM (Finite Element Method), which simulates the Electrochemical Machining (ECM) process. The FEM is used to determine the two-dimensional potential and flux distributions in the electrolyte, in order to estimate surface erosion for a finite time-step. Algorithms have been developed which automatically change the FE mesh, to simulate moving boundaries for tool movement and workpiece erosion. The complex flux distributions produced in the electrolyte have yielded considerable insight into the erosion process for the tool shapes used in practice.
TL;DR: In this paper, the authors present a method for life-cycle analysis of two alternative suction tubes for a vacuum cleaner, and the first approach for an "ecobalance" is outlined.
Abstract: Environmentally clean products and manufacturing technologies are vital in order to be competitive in the future. Beside functional requirements product design must be more and more oriented on ecological effects throughout the life-cycle of products. Life-cycle-analysis permits the comparison and evaluation of various alternatives from the ecological and economical point of view. The method for life-cycle-analysis is illustrated. For two alternative suction tubes for a vacuum cleaner the first approach for an “ecobalance” is outlined.
TL;DR: Combinatorial rules based on the central limit theorem (CLT) in probability theory and uncertainty interval concept are described and compared to two empirical formula rules using two precision machine error source examples reported in the literature.
Abstract: An error budget is an analysis tool for the prediction and control of the total error of a machine system for which accuracy is an important measurement of performance. The error budget concept is commonly applied in designing precision machine tools and precision measuring machines and requires application of a combinatorial rule to assess total error which is contributed to by a number of individual error components. No single generally agreed upon combinatorial rule exists for predicting maximum told error that may result from many error components, and precision machine designers often apply empirical formula rules that have evolved from practical experience. Combinatorial rules based on the central limit theorem (CLT) in probability theory and uncertainty interval concept are described in this paper and compared to two empirical formula rules using two precision machine error source examples reported in the literature. It is shown using Monte Carlo simulations that the CLT combinatorial rules and the empirical formulas adequately predict maximum total errors. However, the CLT rules provides a more rigorous methodology than an empirical formula for predicting total error. Moreover, a confidence level associated with the estimated total errors can be specified for error budgeting in precision machine design.
TL;DR: In this article, a non-contact probe module for high speed measurement of dimensions of a product is presented. And a multi-beam dynamic irradiation probe using the developed module was designed and prototyped for practical application.
Abstract: Summary The paper deals with a development of a new non-contact probe module for the high speed measurement of dimensions of a product The probe module can continuously and simultaneously detect a position and a surface normal vector with custom signal processing algorithm developed A probe module using multiple optical fibers was designed and a simulation was performed for verifying the proposed idea A probe module was also prototyped and tested A successful results were obtained and its performance coincided with the simulation For practical application, a multi-beam dynamic irradiation probe using the developed module was designed and prototyped
TL;DR: In this article, an interactive CAD/CAM system dedicated to the design and manufacture of sheet metal products, has been developed, where the product is defined based on the principles of zero thickness and zero bend radii as well as on manufacturing constraints.
Abstract: Summary An interactive CAD/CAM system dedicated to the design and manufacture of sheet metal products, has been developed. This paper discusses the unique method used by the system for product definition. The product is defined based on the principles of zero thickness and zero bend radii as well as on manufacturing constraints. First, the product is defined in 2-D using nominal dimensions. Then, transformation from the 2-D nominal layout to the real 3-D product is performed by means of manufacturing constraints. These constraints, including bending, welding, and critical dimensions, introduce an important aspect of design for manufacturing.
TL;DR: In this article, the FEM calibration chart for ring upsetting at room temperature is drawn when dealing with annealed Aluminium specimens of different height and the method allows the evaluation of the friction coefficient affecting the plastic flow when teflon films are interposed between dies and specimens.
Abstract: Summary FEM calibration chart for ring upsetting at room temperature is drawn when dealing with annealed Aluminium specimens of different height. The method allows the evaluation of the friction coefficient affecting the plastic flow when teflon films are interposed between dies and specimens.
TL;DR: In this paper, an ultra-precision milling machine with an air spindle with a milling tool and a three-axis feed mechanism was developed for the production of workpieces with sculptured surfaces.
Abstract: Summary The study deals with the development of an ultra-precision milling machine, which allows the production of workpieces with sculptured surfaces. Until now, a variety of precision parts have been produced by ultra-precision diamond turning machines. However, they can not cope with making sculptured surfaces, which have higher requirements. The ultra-precision milling machine developed consists of an air spindle with a milling tool and a three-axis feed mechanism. As a milling tool, a pseudo ball-endmill is designed by slightly offsetting a conventional diamond tool having a nose radius. It is found that the ultra-precision milling machine can produce workpieces with sculptured surface in surface roughness of 70 nm Rmax.
TL;DR: In this article, a methodology for estimating initial and maintenance costs for cold forging tools is presented for use of planners at the early stages of process design, when the sequence of forging operations and equipment are decided and before details of the tooling system are available.
Abstract: Identifying the most appropriate sequence of cold forging operations for a new part requires a number of technological and economical evaluations concerning loads, mechanical properties of the forged component, its producibility on the machines as well as costs for equipment and associate tooling. This paper presents a methodology for estimating initial and maintenance costs for cold forging tools. This methodology is for use of planners at the early stages of process design, when the sequence of forging operations and equipment are decided and before details of the tooling system are available.
TL;DR: In this paper, the authors describe the representation of process planning knowledge utilized in a process planner under development at the Helsinki University of Technology, which puts special emphasis on the representation and processing of group technological part families.
Abstract: Summary The paper describes the representation of process planning knowledge utilized in a process planner under development at the Helsinki University of Technology. The planner puts special emphasis on the representation and processing of group technological part families. Part families are represented on the basis of a feature model which is associated with a family-specific plan specification encoded in a block structured definition language. The plan specification can be evaluated at planning time to yield a process plan. The evaluation process encapsulates the search amongst predefined alternatives and the required consideration of part instance-specific knowledge. The work is considered a contribution to computer-aided process planning methodology.
TL;DR: In this paper, a method for estimating the groove depth in laser machining processes based on temperature measurements was discussed, where the temperature field was measured through infrared thermography, an analytical model relating temperature to groove depth was used to predict the groove depths given a temperature measurement and its location.
Abstract: Summary This paper discusses a method for estimating the groove depth in laser machining processes based on temperature measurements. The temperature field was measured through infrared thermography, an analytical model relating temperature to groove depth was used to predict the groove depth given a temperature measurement and its location. Theoretical and experimental results are compared and discussed.