Tesis sobre el tema "Punching process"

Den fjärde industriella revolutionen, även kallad Industri 4.0, drivs av ett antal teknologier som medför digitalisering och automatisering av industriella processer. Konceptet innebär en applicering av dataanalys med avancerade analytiska verktyg på stora mängder data, vilka påstås ge stora möjligheter för kvalitetsförbättringar. För att en sådan övergång ska ske är förmågan att hantera data avgörande. Trots det uppvisar många företag idag bristande användning av data för att ta beslut. Frågan är hur företag kan göra för att hantera data och utföra en transformation till Industri 4.0. För att studera det här ämnet har det här examensarbetet utförts som en fallstudie på en stansprocess hos Scania Ferruform. Genom en litteraturstudie, kvantitativ datainsamling samt observationer och intervjuer undersökte examensarbetet den nuvarande användning av data i processen. Därefter undersöktes data med statistiska verktyg för att visa på hur data kan hanteras i en process för att erhålla större kunskap om orsaker till avvikelser. Examensarbetet utredde till sist hur fortsatt arbete med datahantering kan utföras för att uppnå målet Industri 4.0.Analysverktyg har använts för att analysera över 39 000 datapunkter. Resultatet visar på att det finns utvecklingsmöjligheter vad gäller insamling, kvalitet och användning av data. Ett ramverk presenteras för hur företaget bör hantera data för att kunna utvinna ny kunskap från deras processer samt hur Ferruform fortsatt kan arbeta mot Industri 4.0.Slutligen ges rekommendationer om fortsatta studier. Resultatet av examensarbetet blir ett stöd för Ferruform i deras arbete mot mer dugliga processer och den tekniska utveckling företaget eftersträvar.<br>The fourth industrial revolution, also called Industry 4.0 is powered by several technologies which result in digitalization and automatization of industrial processes. The concept includes the application of big data and advanced analytics, which are said to provide great opportunities for quality improvements. For such a transition to take place, the ability to handle data is crucial. Despite this, many companies today show a lack of use of data to drive decision-making. The question is how companies can manage data and ultimately transition towards Industry 4.0. To research this topic this thesis has been carried out as a case study of a punching process at Scania Ferruform. Through a literature review, quantitative data collection, as well as observations and interviews, the thesis examined the current use of data in the process. Subsequently, data were examined with statistical tools to illustrate how data can be managed in a process to attain increased knowledge about causes of deviations. Lastly, the thesis explored future work towards Industry 4.0. Analysis tools have been used to analyse over 39 000 data points. The result of the study shows that there are opportunities for development in terms of collection, quality and use of data. A framework of how Ferruform should manage data in order to extract new knowledge from its processes is presented. Furthermore, an action plan is presented for a transition towards Industry 4.0. Finally, recommendations are given for further studies. The result of the thesis will be helpful for Ferruform in its transition towards more efficient processes and the technical development of which the company strives towards.

O presente trabalho foi desenvolvido com objetivo de analisar, comparar e validar, pelos métodos de simulação numérica e experimental, o comportamento do processo de perfuração por puncionamento para o aço AISI4140. Esse estudo será a base para a fabricação de eixos vazados em aerogeradores de energia como, em substituição a eixos maciços usualmente obtidos por fundição. O processo de perfuração por puncionamento é relativamente simples quando comparado com processos de perfuração mais elaborados, como cortes à laser, eletroerosão, usinagem, etc. No desenvolvimento e otimização do processo de perfuração para aplicação nos referidos eixos, surge, como auxílio, o processo de perfuração por puncionamento assistido por simulação computacional pelo Método dos Elementos Finitos - FEM. Neste estudo os corpos de prova, os punções e todo ferramental do processo de perfuração em si, foram modelados computacionalmente no “software” “Simufact.Forming 12.0”, avaliando-se as melhores formas e geometrias dos punções para o processo de puncionamento. Na simulação numérica foi utilizado o aço presente na biblioteca do referido “software” que corresponde ao aço AISI4140. Os resultados presentes na análise do processo computacional de perfuração por puncinamento mostraram que os punções de geometria estreita são os que apresentaram as menores forças para perfuração dos corpos de prova quando comparados às outras geometrias (denominadas de inclinada e pontuda). Para os estudos experimentais, o ferramental proposto foi confeccionado e montado para a devida comparação com os resultados obtidos a partir da simulação computacional. Os experimentos práticos bem como as simulações computacionais, foram montados para corpos de prova cilíndricos a 1100 ºC sendo perfurados por punções a uma velocidade de 3,7 mm/s. De acordo com os dados de força e deslocamento medidos pelo equipamento de aquisição de dados, pela célula de carga e pelo transdutor potenciométrico (LVDT), pôde-se realizar uma análise e estimativa das forças máximas que cada punção exerceu sobre as peças puncionadas. Os resultados das simulações computacionais demonstraram uma variação de 14% a 23% maiores das forças máximas de puncionamento, quando comparadas com as experimentais. Este resultado mostra que o “software” de simulação computacional pode prever, com boa aproximação, a força máxima de perfuração por puncionamento dos punções com diferentes formas e geometrias. O processo de perfuração por puncionamento pode ser considerado uma forma alternativa de perfuração para confecção de furos em corpos cilíndricos que, posteriormente, serão usados para manufatura de eixos vazados pelo processo de forjamento em matriz aberta.<br>This work was developed in order to analyze, compare and validate the methods of numerical and experimental simulation, the behavior of punching a punching process for AISI4140 steel. This study will be the basis for the manufacture of hollow shafts in wind turbine energy as a substitute for solid shafts usually obtained by casting. The puncturing by puncturing process is relatively simple compared to more elaborate drilling processes such as laser cutting, spark erosion, machining, etc. The development and optimization of the drilling process for use in these axes, emerges as an aid, the drilling process by punching assisted by computer simulation by Finite Element Method - FEM. In this study the samples, the punches and tooling throughout the drilling process itself, were computationally modeled on the "software" "Simufact.Forming 12.0", evaluating the best ways and geometries of the punches for the punching process. In numerical simulation was used this steel in the library of that "software" which is the AISI4140 steel. The results presented in the analysis of the computational process of drilling by puncinamento shown that close geometry punctures are those who had the lowest forces for drilling of the specimens when compared to other geometries (called inclined and pointed). For experimental studies, the proposed tooling was made and assembled for due comparison with the results obtained from computer simulation. Practical experiments and computer simulations were assembled cylindrical specimens at 1100 ° C being pierced by a punch of 3.7 mm / s. According to the data of force and displacement measured by the data acquisition equipment, the load cell and the potentiometric transducer (LVDT), it was possible to conduct an analysis and estimate of the maximum forces exerted on each punch punched parts. The results of computer simulations have demonstrated a variation of 14% to 23% higher maximum puncture forces of, when compared with the experimental. This result shows that the "software" of computer simulation can predict with good approximation, the maximum force of drilling by punching the punches of different shapes and geometries. The punching process for punching can be considered an alternative form of drill for making holes in cylindrical objects, which subsequently will be used to manufacture hollow shafts by forging process in an open array.

碩士<br>國立高雄應用科技大學<br>機械與精密工程研究所<br>98<br>Abstract This research investigates the effect of cushion pad on punching process to further reduce the size of micro tag. Previous study has found that the punching load is too large and even causes the buckling of the cutting blade. By adding a cushion pad under the PET film for the tag this fabrication process will decrease the punching load and improve the quality of the micro tag. The micro punch for this study has a multiple parallel blade design. The blades have 180o flat-type and 70o angular-type two tip shapes. The micro punches are made using anisotropic silicon etching and LIGA-like techniques. The KMPR 1050 photoresist is chosen to achieve high aspect ratio structure and good stripability after Ni-Co electroforming. The smallest flat-type blade has a width of 5 μm, depth of 23 μm, and pitch of 30 μm. The smallest angular-type blade has a width of 8μm, depth of 30 μm, and pitch of 48 μm. The overall size of the mold is 5mm × 5mm. The finite element software DEFORM 2D is utilized to predict the required load for micro punching process with cushion pad. The study also investigates other factors such as blade tips, blade width, and PET film thickness. Both theoretical and experimental results show that the punching loads are effectively reduced by using cushion pad. The punching loads for flat-type blades drop more than 40% and there is no bulking even for blade width of 5 μm. This research demonstrates the effect of cushion pad on reduction of punching load and fabrication of 25 μm ×25 μm micro plastic tags. A higher quality of sheared edge and a lower load can be achieved by using the flat-type blades with cushion pad.

碩士<br>建國科技大學<br>自動化工程系暨機電光系統研究所<br>98<br>Abstract The forming process of a gear-ball cup includes drawing and punching stages. The two stages are independent in sequence traditionally. In order to save the cost of die manufacture, it is necessary to combine the two stages to become one new stage. In this paper, the finite element method is employed in conjunction with the abductive network to design the punch height and diameter of the forming process of combined punching and drawing for a gear-ball cup. Different punch heights combined with various punch diameters of the forming process are taken into account as the process parameters in this study. A finite element-based code is utilized to investigate the material flow characteristics under different process parameters, and the abductive network is then employed to synthesize the data sets obtained from numerical simulations, thus establishing a predictive model. From this model, the suitable punch height and diameter for producing an acceptable gear-ball cup with precise inner diameter that fulfills the industrial demand can be found. Keyword: neural network, finite element simulation, combined punching and drawing.

碩士<br>國立高雄應用科技大學<br>機械與精密工程研究所<br>99<br>This study investigates the effect of various process parameters on the micro punching for micro tag fabrication. Both simulation and experimental testing are conducted to study three process parameters including cutting blade width, processing PET film thickness and aluminum cushion pad thickness. Finally, the blade width of the punch is decreased from the existing 5μm down to 3μm to further reduce the size of micro tags. Special feature of this research is only upper punching die used for micro tag fabrication. The cushion pad under the processing film is deformed accordingly as the cutting blades. It generates a shearing effect on the film. The micro punches are made by applying KMPR thick film photolithography, nickel-cobalt electroforming and mould removal processes. All the punches have a multiple parallel blade design. The blade widths are 15μm and 10μm for process parameter study and 5μm and 3μm for micro tag fabrication. The finite element software DEFORM-2D is utilized to analyze deformation and punching load during micro punching process. The PET film thickness of 16μm、 12μm、9μm、7μm and 3.5μm and aluminum cushion pad thickness of 20μm, 15μm and 10μm are used for this study. Both theoretical analysis and experimental results show that the punching load is reduced with thin blade and thin processing film. The cushion pad thickness has little effect on the punching load if its dimension is larger than the blade width. It concludes that the blade width and processing film thickness are two most important factors for micro punching process. The theoretical model for process parameter analysis is considerably improved from previous study. However, the same model has larger than expected error when applied for micro tag fabrication analysis. Since the punching machines and experimental setup used for two cases are totally different there is a need for further clarification in the future. The micro tags of 15μm×15μm are successfully fabricated using micro punch with blade width of 3μm and PET film thickness of 3.5μm and 7μm. The micro tags can be widely applied in anti-counterfeiting applications.

碩士<br>國立臺灣大學<br>機械工程學研究所<br>103<br>In the punching process, the iron loss of the electrical steel sheet will increase dramatically due to the plastic strain. So far, the iron loss effect of electrical steel sheet in the punching process may be difficult to predict and control. This effect also reduces the overall efficiency of the motor. In this research, the plastic strain of electrical steel in the punching process is determined by the working hardening theory. In order to create the plastic strain, a punching mold of stator slot was designed, including 82.0°, 86.7°, 88.0° angle between two lines and 0.25mm, 1mm, 2mm, 6mm fillet radius. Under the fixed geometry, the influence of punching speed, blank holder pressure, counter punch pressure and punching mode on hardening area are measured. The results show that the hardening area is reduced by raising the punching speed, punching with vibration mode, and punching with appropriate blank holder and counter punch pressure. In addition, under the fixed punching parameters, the influence of the angle between two lines and the fillet radius of the stator slot on hardening area are analyzed. The hardening area decreases along with the larger fillet radius and the larger angle between two lines.

碩士<br>國立高雄大學<br>電機工程學系--先進電子構裝技術產業研發碩士專班<br>105<br>Ball grid array becomes popular in advanced electronic package technology due to the demand of thinner and lighter package for 3C electronics. In convention, mechanical punching is the tool used for substrate separation of thin BGA substrate. However, issues of cracking in punching lead to low yield rate. This thesis is focused on the study of improving the punch process by the help of UV laser machining. In the experiments, parameters of laser cutting; such as laser power and cutting speed were investigated to achieve an optimized U shape of laser machining groove for the release of cracking in punching process. As a results, it showed that the laser U grooving process was effective to improve the yield of punching process. In addition, it was also found that deep groove can be achieved by higher power of UV laser cutting and was benefit to the quality of punching and the yield as well.

碩士<br>國立高雄應用科技大學<br>機械與精密工程研究所<br>103<br>This study examines the micro stamping using only the upper and lower die,when the influence of tool shape and die gap and material thickness and other factors, the material sheet quality how to choose to make punchingout the best, and discussed the influence of factors on micro stamping is the largest. When the mold gap more and more hours to do out of the mold, high accuracy and have good contraposition precision machine and its cost is very high, does not meet the commercial interests, so the discussion when there are underlying material instead of the lower die, can achieve its ownmaterial piece of good quality, if the material thickness, strength andcushion the lower pad thickness changes on micro stamping results with what effect. The characteristics of this study is micro stamping experiment using only theupper die, lower die using the underlying deformation forming, punchingsheet to achieve the effect of. Micro stamping die is used for photolithography process will be made into KMPR thick photoresistphotoresist mold, sent to the electroformed nickel cobalt alloy, and finally demoulding to obtain micro stamping tool. This study uses the DEFORM finite element software to simulate micropunch pressing process of deformation and forming load force, first by using the 2D software simulation using only the upper and lower diestamping simulation, again following pads replaced the lower die stamping,finally carried on the 3D simulation analysis, to explore the effect ofchanging the shape of tool for micro stamping. The use of edge width 15 m three and six selection cutting tool stampingthree PET material thickness and three kinds of aluminum foil in this studyto investigate the underlying thickness, when the material thickness changeand foil underlying changes, what is the impact on stamping, and the simulation analysis and experimental verification. This study examines when changing the micro stamping tool shape, whether can increase its stamping life, in order to reduce the cost of.

碩士<br>國立高雄應用科技大學<br>模具工程系碩士班<br>94<br>The technology of micro punching plays an important role in the manufacturing of micro metallic components. The micro punching process is however affected by many factors including materials, tooling and process conditions, and is difficult to be controlled. Therefore, it is highly interested in searching for a new method to improve the quality of the sheared edge as well as to reduce lead time and costs in the micro punching industry. A set of dies in order to punch a 3 mm diameter hole on metallic sheets was designed for the study. By varying the clearance between the punch and die, the force applied by the blank holder and the punch speed, micro punching experiments were carried out. The materials of the sheets are copper (C1100), stainless steel (SUS304) and high-carbon steel (SK5) and the sheet thickness is 0.1 mm. The sheared edges were then examined by a microscope with an on-line measuring system to quantify the quality of the burnishing surface. The Taguchi method was finally used to analyze the effects of process conditions on the quality of the sheared edge in micro punching. The results show that the effects of the blank holder force and the punch speed on the length of the burnishing surface are not significant. To obtain a larger burnishing surface, i.e. a higher quality of the sheared edge, it is not necessary to use a smaller clearance between the punch. The clearance should also been adjusted by the tensile strength of punching material.

碩士<br>國立高雄應用科技大學<br>模具工程系碩士班<br>95<br>The study uses a commercial simulation package and Normalized Cockcroft and Latham fracture theory to predict the sheared edge of micro punched sheet metals. Experiments and the Taguchi method are also employed to find the conditions for the best quality of the sheared edge in micro punching process. The considered metallic sheets are stainless steel, aluminum and copper with the thickness of 0.2, 0.1 and 0.05 mm. The investigated process parameters include the clearance between the punch and the die, the punch speed and the force applied by the blank holder. Tensile tests at different strain rates were performed in order to obtain the stress-strain curves for the use in the numerical simulations. A set of dies in which the clearance can be adjusted was also designed and constructed. By using the Taguchi’s orthogonal array, the values of the selected parameters were determined by the experiences from conventional punching processes. After punching experiments, the images of sheared edges were captured by the camera mounted on a microscope and analyzed by a measuring software. The results show that numerical simulation can be used to predict the sheared edges in the micro punching process if the criteria for the fracture can be appropriately defined. The material strength and the clearance between the punch and the die are main factors affecting the quality of the sheared edge. The results also help researchers to understand the behavior of forming and to improve the quality of the sheared edge in the micro punching process.

碩士<br>國立雲林科技大學<br>機械工程系碩士班<br>91<br>This paper describes a hybrid process system to integrate of micro-electro discharge machining (micro-EDM) and micro-punching that uses electrode arrays to achieve high throughput and in the machining. It explores constraints on the fabrication and usage of high aspect ratio micro-EDM fabricated electrode arrays. An array of 36 WC electrodes with 90 μm diameter was used to machine perforations in 100μm thick Cu plank.The electrode arrays can be applied to micro-punching that be used to punching with thermo-plastic material.

碩士<br>國立臺灣大學<br>機械工程學研究所<br>106<br>The iron loss of the silicon steel sheet increase due to the plastic strain and residual stress after punching process. This effect also reduces the efficiency of the motor. In the past, there is no method to realize how the punching process under different punching conditions affect the extra iron loss value. Due to the limitation of the thickness of the silicon steel sheet, punching shape and the influence area in the cutting edge after punching, the iron loss value can only be estimated by measuring the value of work hardening. In the past, it has been experimented that the difference of iron loss value can be compared by using the strain-iron loss relationship and the strain-work hardness relationship. However, it takes a lot of time and there is personal error in the test. In this study, we simulate the punching process of silicon steel sheet by the finite element method software-ABAQUS. With this software, we can compare the strain distribution and the change of iron loss in the cutting edge of silicon steel sheet made by different punching condition. The parameters discussed include the chamfer size of punch, punch speed, and punching with vibration mode. Due to the limitations of punching tools and experiment time, we could only roughly compare the difference between different punching condition before. But now, with the advantage of computer simulation, we can modify the model at any time and calculated quickly, and we can also get a large number of data. The simulation process is fine blanking, take silicon steel sheet 35CS250 as simulation object. The results show that in terms of punch chamfer size, the punch chamfer in the range of 0.15mm is the best for reducing the extra iron loss. In terms of punch speed, if the punch speed is much more fast, we will get a lower extra iron loss. In terms of vibration mode of punch, the simulation results show that the punch vibration will cause multiple impacts on the silicon steel sheet, it will increase the strain and the extra iron loss in the cutting edge, so the vibration mode does no help to improve the extra iron loss of the cutting edge.

碩士<br>國立臺灣大學<br>機械工程學研究所<br>105<br>In recent years, with the awareness of environmental protection and energy conservation, the reduction in weight of automotive structures is one of the goal of the automobile industries. At present, the using of high strength steel as the automotive structure in order to meet the strength, safety, and lightweight. However, increasing the strength of steels leads to the defects of low formability and spring back in sheet metal forming, which disadvantageous to the design of the product. While in the hot stamping process the above-mentioned forming defects could be much improved and the tensile strength of the product parts is above 1400MPa. After hot stamping, hot stamped parts generally require a subsequent shearing process such as punching, trimming, and blanking. However, it is not easy to punch hot stamped parts having high strength. The extremely high strength of hot stamped parts cause severe tool wear due to large punching load. Because of high costs for repairing punching tools, laser cutting has been used in almost all automotive industries in spite of the long process time and the high production cost, it is necessary to develop economical shearing methods for use on the hot stamped parts. In this study first focus on the mechanical punching method studies, then the finite element simulations of punching of hot stamped parts are performed to investigate the effects of the process parameters on the sheared surface quality and the maximum punching force. It is found that the punching temperature of 22MnB5 between 550°C and 650°C, the clearance is less than 12.5%, and hot semi punching depth is above 80% are suitable for the process conditions during hot stamping and simultaneous punching in a single press. The parameters from this range are applied to the study of thickening of hole edge in the simulation. The onset and progress of fatigue cracks of punched hot stamped parts are accelerated around holes due to concentration of stress, residual stress and sheared surface quality. The improvement of the quality of the sheared surface and the increasing of thickening of the hole edge improve the fatigue strength of high strength steel in the research. In this study, a punching process including thickening of a hole edge of the hot stamped parts with a punch and die shape to improve fatigue strength of the punched hot stamped parts during the hot stamping process. However, it is not easy to design cooling channels for taking out punching scraps from die, a double taper punch is designed to improve the hot semi punching depth above 90% (thickness of blank), fully punching after quenching. It is shown that the maximum punching force and production time can be reduced effectively. Finally, punches design are investigated by finite element simulation and experiment for the actual process in the future.