Inhaltsverzeichnis
Auswahl der wissenschaftlichen Literatur zum Thema „Heavy workpieces“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit den Listen der aktuellen Artikel, Bücher, Dissertationen, Berichten und anderer wissenschaftlichen Quellen zum Thema "Heavy workpieces" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Zeitschriftenartikel zum Thema "Heavy workpieces"
1
Qiu, Xue Song, Liang Wang, Lei Wang, Jia Qi Liu und Yu Lin Zhou. „Development of a 90°/180° Upender for Large and Heavy Workpiece by Using Airbags-Drived Flipping Worktable“. Advanced Materials Research 915-916 (April 2014): 228–35. http://dx.doi.org/10.4028/www.scientific.net/amr.915-916.228.
Der volle Inhalt der QuelleAnnotation:
There is a serious security problem in the process of workpieces flipping, which restricts the increase of production capacity in manufacturing process of large workpieces applied in nuclear power equipment. The shapes and characteristics of flipping workpieces were analyzed; the general model of workpieces outer contour was established. The design goals of heavy castings and forgings cold-work turnover mechanism were formulated based on the requirements of turning process, then the basic constraint-face was build and the geometric constraint-model was uniformed. A novelty 3- DOF planar serial mechanism of heavy upender was proposed whose overall configuration consists of three movements, that is roll, mobile, folding turn, which can realize the double function of turning 90 ° and 180 ° of large workpiece as hollow cylindrical, conical and spherical crown three types. On this basis, the airbags-drived flipping worktable was designed; Topological optimization of flipping worktable was further conducted. Its key technology will provide useful ideas and references for the development of large heavy duty positioner and turnover machine with its other related equipment.
2
Rajaraman, Mabaran, Kyle Bannerman und Kenji Shimada. „Inventory Tracking for Unstructured Environments via Probabilistic Reasoning“. Logistics 4, Nr. 3 (14.07.2020): 16. http://dx.doi.org/10.3390/logistics4030016.
Der volle Inhalt der QuelleAnnotation:
Workpiece location is critical to efficiently plan actions downstream in manufacturing processes. In labor-intensive heavy industries, like construction and shipbuilding, multiple stakeholders interact, stack and move workpieces in the absence of any system to log such actions. While track-by-detection approaches rely on sensing technologies such as Radio Frequency Identification (RFID) and Global Positioning System (GPS), cluttered environments and stacks of workpieces pose several limitations to their adaptation. These challenges limit the usage of such technology to presenting the last known position of a workpiece with no further guidance on a search strategy. In this work we show that a multi-hypothesis tracking approach that models human reasoning can provide a search strategy based on available observations of a workpiece. We show that inventory tracking problems under uncertainty can be approached like probabilistic inference approaches in localization to detect, estimate and update the belief of the workpiece locations. We present a practical Internet-of-Things (IoT) framework for information collection over which we build our reasoning. We also present the ability of our system to accommodate additional constraints to prune search locations. Finally, in our experiments we show that our approach can provide a significant reduction against the conventional search for missing workpieces, of up to 80% in workpieces to visit and 60% in distance traveled. In our experiments we highlight the critical nature of identifying stacking events and inferring locations using reasoning to aid searches even when direct observation of a workpiece is not available.
3
Qiu, Xue Song, Lei Wang, Da Xing Zeng, Jia Qi Liu und Yu Lin Zhou. „Design of the Main Parameter of Large and Heavy Workpieces Upender for Shell Units of Nuclear Power and Hydrogenation Equipment“. Applied Mechanics and Materials 389 (August 2013): 143–48. http://dx.doi.org/10.4028/www.scientific.net/amm.389.143.
Der volle Inhalt der QuelleAnnotation:
In the production process for large and heavy workpieces of Nuclear Islande equipment and Hydrogenation reactor, Turn is the important technics of the convergence of every technological process, and a direct impact on production efficiency and production safety and production quality. The researching and manufacturing of overloaded upender for large and heavy workpieces will effectively contribute to the improvement of the production capacity. The force model under maximum load conditions is established. The force of upender body in the eversion process is analyzed. The main drive torque formula for upender turnover is obtained. From the actual functioning of the overloaded upender for large and heavy workpieces, carring a maximum load, the upender flip process is dynamic simulation on ADAMS. After the results were compared with theoretical calculations showed that: the variation between the two is consistent. The main parameter for driving of upender is designed. By theoretical calculations confirming simulation with each other, in simulation model, the feasibility of using the contact vice for defining non-hinged rotation vice is verified. And a new solution is provided for adding non-hinged rotation vice constraints to a similar shstem dynamics model. In this paper work it has an engineering value for the design of large and heavy equipment.
4
Šajgalík, Michal, Tomáš Pavlusík, Jozef Pilc, Matej Mikloš, Igor Daniš, Juraj Martinček und Jozef Pustay. „Identification of Residual Stress in the Production of Molding Tools by Turn-Milling Technology“. Technological Engineering 14, Nr. 1 (26.10.2017): 14–16. http://dx.doi.org/10.1515/teen-2017-0003.
Der volle Inhalt der QuelleAnnotation:
Abstract This article describes how to plan the tool path and analyze the surface of the machined part by working simultaneously on two basic operations such as milling and turning. New machine tools allow parallel processing of both multi-axis tools at the same time, it is a production technology in which the workpiece and the tool are simultaneously rotating. This relatively new turnmilling technology could be an alternative to increasing productivity in many applications. Especially in cases involving heavy-duty materials or large diameters of machined surface. The aim of this study is to explore this new technology, especially with regard to the increased precision and quality of the surface of the workpiece. Experimental results show that the combination of these two operations is suitable for precise machining of rotationally symmetrical workpieces with high surface finish.
5
Cui, Gang Wei, Feng Lan Cheng, Dong Gao, Qing Xin Ma und Yi Lei Liu. „Real-Time Compensation of Ram Thermal Elongation Errors for Heavy-Duty Numerical Control Machine Tool“. Advanced Materials Research 317-319 (August 2011): 1964–67. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.1964.
Der volle Inhalt der QuelleAnnotation:
Thermal error of machine tool is the main in total machine tool error, and obviously impairs the accuracy of the machined workpieces. Ram is a very important component of heavy-duty floor type boring-milling machine, and its thermal deformation is a significant source causing errors in machining process. Aiming at the thermal elongation of heavy type milling boring machine tool ram, the machine tool thermal errors are measured and compensated. Temperature compensation function in NC system is applied. Experiment results shows that 90% ram positioning error can be compensated.
6
Wu, Ming Yang, Yong Tian, Yao Nan Cheng, B. Wang und Y. B. Gao. „Digital Rapid Modeling Design of Heavy-Duty Cutting Blade Based on Solidworks“. Materials Science Forum 800-801 (Juli 2014): 660–65. http://dx.doi.org/10.4028/www.scientific.net/msf.800-801.660.
Der volle Inhalt der QuelleAnnotation:
Heavy machinery processing industry has its own disadvantages, that is, the large size and heavy weight of workpieces. Some of them may even weigh hundreds of tons. When processing horizontal lathe, the turning diameter of it can be as long as six meters and the vertical lathe can reach ten meters. Heavy duty cutting mainly concerns about how to improve the processing efficiency, enhance the equipment utilization and to reduce energy consumption. Therefore, this proposes a higher requirement to heavy cutting tool, especially the design of the blade is of great importance. Based on the analysis of heavy cutting blade’s structure, this dissertation uses the method of parametric design which is suitable for Solidworks, with the combination of OLE and COM technology. It also utilizes Visual Basic on the Solidworks platform for secondary development and design, and develops the fast digital modeling software design. The software can not only realize the rapid modeling of heavy cutting blade, but also shorten the design cycle and improve the efficiency of the cutting tool which benefited from the convenient design of the heavy blade, which has a significantly practical application value.
7
Cai, Li Gang, Xiang Min Dong, Zhi Feng Liu und Tie Neng Guo. „Stiffness Study of Swing Chainon Heavy Duty Deflection Angle Milling Head“. Key Engineering Materials 439-440 (Juni 2010): 1287–93. http://dx.doi.org/10.4028/www.scientific.net/kem.439-440.1287.
Der volle Inhalt der QuelleAnnotation:
Heavy duty deflection angle milling head is the core functional unit of heavy-duty gantry CNC machine tools. Stiffness of swing chain system is one of the important factors that determines accuracy of heavy duty deflection angle milling head. In order to improve dynamic performance and mechanical precision, the gear pair and support system of the swing chain are studied in the paper. Based on the deformation compatibility condition and the superposition theorem, the torsional deformation and stiffness of each part are analyzed, and considered the deformation of workpieces and supporting system and the interaction of them. The vulnerable segment is found out in the paper, which is valuable to amend and improve the design of milling head. At last, the curves of the relation between the swing chain stiffness and the gear parameters and bearing preload are charted, which provide the theory and technical support for digital design, optimization of the milling head and the basis for the similar driving system stiffness calculation.
8
Nedashkovskiy, K. I., A. V. Gulshin, Yu M. Averina, V. A. Naumkina, V. V. Menshikov und V. S. Boldyrev. „Investigating Corrosion Resistance of Heavy-Duty Steel Fasteners Regarding Assemblies Operating in Maritime Climates under High Pressures Power, Metallurgical and Chemical Engineering“. Herald of the Bauman Moscow State Technical University. Series Mechanical Engineering, Nr. 1 (130) (Februar 2020): 94–106. http://dx.doi.org/10.18698/0236-3941-2020-1-94-106.
Der volle Inhalt der QuelleAnnotation:
The paper presents investigation results and a technology for manufacturing fastener workpieces out of the 07Kh16N6-Sh (07Х16Н6-Ш) steel using high-temperature heat treatment. The steel undergoing our testing was additionally doped with molybdenum, as reflected in the 07Kh16N6M-Sh (07Х16Н6М-Ш) designation, which facilitated grain refinement. We implemented accelerated climate testing of bolts in order to assess the corrosion cracking resistance of 07Kh16N6-Sh (07Х16Н6-Ш), 07Kh16N6M-Sh (07Х16Н6М-Ш) and 13Kh15N4AM3-Sh (13Х15Н4АМ3-Ш) steel fasteners in maritime climates.
9
Dryba, S., J. Meißner, M. C. Prof Wanner und O. Wurst. „Hochpräzises Bearbeiten von Schiffspropellern*/High-precision machining of very large ship propellers“. wt Werkstattstechnik online 107, Nr. 03 (2017): 182–88. http://dx.doi.org/10.37544/1436-4980-2017-03-78.
Der volle Inhalt der QuelleAnnotation:
In der industriellen Fertigung sind Industrieroboter weit verbreitet [1]. Durch ihre Flexibilität und Schnittstellenvielfalt sind sie für den Ansatz Industrie 4.0 von immenser Bedeutung. Einige Bereiche der Industrie, beispielsweise Gießereien, sind bisher von dieser Entwicklung ausgeschlossen. Viele Werkstücke, die hier zu handhaben oder bearbeiten sind, überschreiten die Arbeitsräume und Lastmomente verfügbarer Industrierobotersysteme. Der Fachbeitrag beschreibt die Entwicklung eines Schwerlast-Großrobotersystems sowie dessen Applikation in einer Gießerei für große Werkstücke. The use of industrial robots is prevalent in today’s industry [1]. Due to flexible applications and a large variety of interface options, they play a vital role in implementing “Industry 4.0”. As industrial robots offering sufficiently large work spaces and handling heavy payloads are not available today, specific industrial areas, such as foundries, have been mostly excluded from this progress. This paper describes the development of a new heavy-duty industrial robot system, as well as its application in a foundry for large workpieces.
10
Gehlhoff, Felix, und Alexander Fay. „On agent-based decentralized and integrated scheduling for small-scale manufacturing“. at - Automatisierungstechnik 68, Nr. 1 (28.01.2020): 15–31. http://dx.doi.org/10.1515/auto-2019-0105.
Der volle Inhalt der QuelleAnnotation:
AbstractSmall-scale manufacturing often relies on flexible production systems that can cope with frequent changes of products and equipment. Transports are a significant part of the production flow, especially in the domain of large and heavy workpieces that requires explicit planning to avoid unnecessary delays. This contribution takes a detailed look at how to create feasible integrated schedules within a decentralised or even heterarchical architecture and which information the agents have to exchange. These schedules incorporate constraints such as the blocking-constraint. They also consider dynamic setup and operation durations while finding a good-enough solution. The proposed agent-based solution applies to a wide variety of scheduling problems and reveals positive properties in terms of scalability and reconfigurability.
Dissertationen zum Thema "Heavy workpieces"
1
Bezděk, Petr. „Konstrukční návrh otočného stolu s nosností 65 000 kilogramů“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443716.
Der volle Inhalt der QuelleAnnotation:
The diploma thesis deals with the design of a rotary table for machining large non-rotary workpieces up to a maximum weight of 65 000 kg. The aim of the work is to analyze and evaluate the current state of knowledge in the field of rotary tables, to create a table design according to the assignment and its 3D model with part of the drawing documentation. The theoretical part of the work searches for solutions used in the construction of rotary tables in the category of table according to the assignment. The information obtained is further used in the design of rotary table solution variants. By evaluating the weight of the required properties and their degree of fulfillment, a variant of the design solution of the table is selected, which is then designed. The individual design steps are described and explained in the text part of the work accompanied by pictures and calculations. The result of the process is a structural design of the mechanical part of the rotary table with a 3D model and partially processed drawing documentation. The contribution of the work is the summarization of relevant information for the design of rotary tables, the processed procedure of solving the design of the table and the modeled design of the rotary table. These outputs can be further treated as documentation for the production of the designed table, the development of the rotary table design to deeper details or technical development in this area.
Konferenzberichte zum Thema "Heavy workpieces"
1
Yu, Qiankun, Guolei Wang, Tianyu Ren, Xiaotong Hua und Ken Chen. „Starting Base Position Optimization in Integrated Task Planning for Mobile Manipulators Painting Large Workpieces“. In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70465.
Der volle Inhalt der QuelleAnnotation:
In order to paint large workpieces, heavy painting manipulators are always transported by mobile platforms due to their limited workspaces. To reduce the vibration of the end-effector, the base velocity of the manipulator is constant when painting. In this operation mode, the Starting Base Position (SBP) of the manipulator is important to attain the maximum manipulability and dexterity. This paper aims to optimize the SBP for painting a specified surface efficiently. An approximated decouplable model of painting manipulators is first built to get the analytically expressed inverse kinematic solutions. Then joint-level criteria for one manipulating point reflecting the manipulability and dexterity are proposed, followed by the combined criterion for a painting task about SBP with consideration of the platform velocity. Afterwards, the SBP optimization problem is translated into a least squares problem. To solve such a problem, an initial SBP value is first calculated through an algorithm based on internal penalty function method. Then a modified Levenberg-Marquardt method is employed to get the optimal SBP. Results of applications on painting a straight and an arc path indicate that the method proposed is effective and efficient.
2
Yip-Hoi, Derek. „Multi-Resolution Cutting Force Prediction Using a Quad-Tree Decomposition for Cutter/Workpiece Engagements“. In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-29003.
Der volle Inhalt der QuelleAnnotation:
Virtual Machining (VM) is the use of computers to simulate the physics of machining processes. It can be used to effectively identify problems in machining complicated workpieces and in optimizing processes. At the heart of VM is the ability to predict the cutting forces generated as the tool generates chips at the tool workpiece interface. For these predictions to be realistic two things are necessary. First, accurate representations of how the cutter engages the workpiece need to be generated along each toolpath under consideration. This is referred to as the Cutter/Workpiece Engagement (CWE). Second, a force model is needed that integrates the contribution from each element within the CWE. In this paper a new technique for integrating the force contributions is presented. It utilizes a Quad-Tree representation for the CWE. This representation provides several advantages over other approaches for integrating the force contributions. Amongst these is the ability to represent the aggregated force at different resolutions. This has the potential to reduce the time required to perform a simulation by scanning a tool path at a lower resolution to bound intervals where heavy engagements are encountered. These intervals can then be analyzed at a higher resolution for greater accuracy. Examples are presented using CWEs extracted for 2 1/2D milling operations from a component modeled on a leading CAD/CAM system.
3
Scholtes, Dominik, Stefan Seelecke, Gianluca Rizzello und Paul Motzki. „Design of a Compliant Industrial Gripper Driven by a Bistable Shape Memory Alloy Actuator“. In ASME 2020 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/smasis2020-2204.
Der volle Inhalt der QuelleAnnotation:
Abstract Within industrial manufacturing most processing steps are accompanied by transporting and positioning of workpieces. The active interfaces between handling system and workpiece are industrial grippers, which often are driven by pneumatics, especially in small scale areas. On the way to higher energy efficiency and digital factories, companies are looking for new actuation technologies with more sensor integration and better efficiencies. Commonly used actuators like solenoids and electric engines are in many cases too heavy and large for direct integration into the gripping system. Due to their high energy density shape memory alloys (SMA) are suited to overcome those drawbacks of conventional actuators. Additionally, they feature self-sensing abilities that lead to sensor-less monitoring and control of the actuation system. Another drawback of conventional grippers is their design, which is based on moving parts with linear guides and bearings. These parts are prone to wear, especially in abrasive environments. This can be overcome by a compliant gripper design that is based on flexure hinges and thus dispenses with joints, bearings and guides. In the presented work, the development process of a functional prototype for a compliant gripper driven by a bistable SMA actuation unit for industrial applications is outlined. The focus lies on the development of the SMA actuator, while the first design approach for the compliant gripper mechanism with solid state joints is proposed. The result is a working gripper-prototype which is mainly made of 3D-printed parts. First results of validation experiments are discussed.
4
Kumanotani, Maho, Hitoshi Kusino und Keiichi Nakamoto. „Proposal of a Tool Path Generation Method to Ensure Workpiece Stiffness for Efficient Rough Machining“. In JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/lemp2020-8543.
Der volle Inhalt der QuelleAnnotation:
Abstract Recently, the demand of complex shape parts has increased in the aircraft and medical industries. In these parts machining, the displacement and vibration of workpiece that strongly affect the machining efficiency are induced due to the heavy change of the unmachined workpiece shape and stiffness during rough machining. However, it is difficult to automatically determine machining parameters of operation planning by using a commercial CAM software because there is a large number of combinations. Therefore, in order to improve the efficiency of complex parts machining, the authors proposed a determination method of workpiece shapes during rough machining based on topology optimization relevant to maximizing static stiffness. On the other hand, tool paths that directly affect the workpiece stiffness are not generated automatically to create the calculated workpiece shapes in the previous study. From these reasons, this study proposes a generation method of tool paths by using design variables obtained through the calculation of topology optimization. The tool paths are simply generated based on design variables and enables to ensure the workpiece stiffness during rough machining because design variables are strongly related to the objective function. By conducting a machining experiment assuming complex parts machining, it is confirmed that the proposed method has a potential to realize efficient rough machining.
5
Dang, Xiaobing, Kai He, Feifei Zhang, Qiyang Zuo und Ruxu Du. „A New Incremental Bending System to Form Curved Metal Plate by Experiment and Finite Element Simulation“. In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-86800.
Der volle Inhalt der QuelleAnnotation:
Bending curved metal plate is an important process for many heavy industries such as shipbuilding. It is a basic process to manufacture hull surface. The conventional method is the so-called line heating method, which is not only labor intensive but also inefficient and error-prone. We have presented a new method of incremental bending. In this paper the incremental bending system is explained from its hardware and software. A kind of curved metal plate is formed by experiment and finite element simulation. The manufactured workpiece is of high quality with smooth surface. The presented method can be successfully used to form curved metal plate. It is a highly flexible forming method. It would have a wide application in industry.
6
de Jong, Jan J., J. P. Meijaard und Volkert van der Wijk. „The Influence of Partial Force Balancing on the Shaking Moments, Contact Forces, and Precision of a Delta Robot-Like Manipulator in a Compliant Frame“. In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-86189.
Der volle Inhalt der QuelleAnnotation:
For the Delta robot, a high-speed parallel pick-and-place manipulator, base vibrations are a significant problem. Especially since the Delta robot is suspended above its workpiece, it requires a large, stiff, and heavy base frame for fast and accurate motions. Dynamic balancing of the shaking forces and the shaking moments is a known technique to reduce the dynamic loads on the base frame and to the surroundings. In this paper it is investigated how solely with partial force balancing, dynamic loads and pick-and-place accuracy of a Delta robot-like manipulator can be improved, considering also the compliance of the base frame. This is done since partial force balance solutions can be implemented relatively simply in the current Delta robot designs, whereas full force and moment balance solutions are complex to apply in practice. Numerical simulations with a representative planar model of a Delta robot-like manipulator with a compliant base frame show that with an increasing amount of force balance the shaking moments increase up to 16% for full force balance. The floor contact forces first reduce and then increase with increasing force balance. With 43% force balance the floor contact forces are minimal, giving a 63% reduction. The end-effector accuracy slightly improves with increasing force balance until full force balance yields a 31% accuracy improvement. A further increase of the force (over) balance shows a 59% improvement of end-effector accuracy for 350% force balance. These effects are mainly due to the typical design of the Delta robot base frame and the way the robot is mounted to it.
7
Nakano, Y., und H. Takahara. „Countermeasure Against Regenerative Chatter in End Milling Operations With Vibration Absorbers“. In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37818.
Der volle Inhalt der QuelleAnnotation:
Chatter can result in the poor machined surface, tool wear and reduced product quality. Chatter is classified into the forced vibration and the self-excited vibration in perspective of the generation mechanism. It often happens that the self-excited chatter becomes problem practically because this causes heavy vibration. Regenerative chatter due to regenerative effect is one of the self-excited chatter and generated in the most cutting operations. Therefore, it is very important to quench or avoid regenerative chatter (hereafter, simply called chatter). It is well known that chatter can be avoided by selecting the optimal cutting conditions which are determined by using the stability lobe of chatter. The stability lobe of chatter represents the boundary between stable and unstable cuts as a function of spindle speed and depth of cut. However, it is difficult to predict the stability lobe of chatter perfectly because the prediction accuracy of it depends on the tool geometry, the vibration characteristics of the tool system and the machine tool and the material behavior of the workpiece. In contrast, it is made clear that the stability lobe of chatter has been elevated in the wide range of spindle speed by the vibration absorber in the turning operations. However, it should be noted that none of the previous work has actually applied the vibration absorbers to the rotating tool system in the machining center and examined the effect of the vibration absorbers on chatter in the end milling operations to the best of authors’ knowledge. In this paper, the effect of the vibration absorbers on regenerative chatter generated in the end milling operations is qualitatively evaluated by the stability analysis and the cutting test. It is made clear the relationship between the suppression effect of the vibration absorbers and the tuning parameters of them. It is shown that the greater improvement in the critical axial depth of cut is observed in the wide range of spindle speed by the properly tuned vibration absorbers.
8
Petrenko, O., E. S. Geskin, G. A. Atanov, B. Goldenberg und A. Semko. „Investigation of Material Deformation by the High-Speed Water Slugs“. In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33782.
Der volle Inhalt der QuelleAnnotation:
Water constitutes an attractive manufacturing tool It is readily available and clean. The waterjets are conventionally used for surface cleaning, material removal, and surface modification. The intrinsic shortcomings of such an application are the need in the use of expensive and heavy pumping facilities and, what are more important, peculiarities of the waterjet-substrate interaction which limit material deformation by the incoming jet. These shortcomings are eliminated if the workpiece is impacted by the array of the water slugs, generated by the direct injection of high-intensity energy pulses into the water vessel (barrel) and ejection the portion of the water via the nozzle attached into the barrel. Such a device (barrel-nozzle combination) will constitute an effective and versatile manufacturing tool. Understanding of the phenomena that occur in the course of the energy injection into the water is necessary for the design of the desired device. The phenomena in question are determined by the ratio between the speed of the water in the barrel in the course of the energy injection and the speed of the shock waves in the water. If this ratio is much less than unity, the exit velocity is determined by the ratio between the cross section areas of the nozzle exit and the barrel. If the ratio in question approaches the unity, the water velocity at the nozzle exit is determined by the impact pressure. The device utilizing this principle is termed the water extruder. If however, the ratio is much more than unity the exit water velocity is determined by the superposition of shock waves developed in the fluid. This device termed the water cannon is able to accelerate the water slug to the speed far exceeding 1,000 m/sec. The numerical and experimental studies of water extruder were carried out. The numerical models were constructed and the variation of the water velocity and the water pressure in the barrel were investigated. Experimental setup for the study of the water extruder was constructed by the modification of Remington power tool. The experiments involved the piercing of metal strips. The effect of operational conditions on the maximal depth of the piecing was determined. Another series of experiments involved the study of the slug impact on plastic (lead) and brittle (concrete) materials. The effect of the stand off distance on the removal of both kinds of material was investigated. As the result the suggestions about the way of construction of the water extruders and their practical applications were made.