Error Size of the Helix (screw) Groove by Grinding

2011 ◽  
Vol 496 ◽  
pp. 19-24
Author(s):  
Karel Jandečka
Keyword(s):  
Present Article ◽  
Analytical Method ◽  
Grinding Wheel ◽  
Theoretical Studies ◽  
Spiral Groove ◽  
Grinding Wheels ◽  
Know How ◽  
Foreign Companies ◽  
Grant Agency ◽  
Helical Grooves

This paper presents further results in addressing this issue and builds upon the results obtained within the project GACR No. 101/07/0751 (research was supported by Czech Grant Agency), and the findings and information obtained from grant project GACR No. 101/05/2562. The problems are oriented to the production and sharpening of rotary tools, especially because all the know-how is owned by foreign companies. The main chapter is devoted to "Solution of the dependance of undercutting of the helical grooves on the grinding wheel diameter, its thickness and depth of the cut" at zero thickness of the grinding wheel. This method is an original analytical method for calculating the undercutting and is a part of the theoretical studies of the grinding helix slot. Then follows a passage, which defines the actual width of the spiral groove profiles at various grinding wheels. The present article summarizes only part of a broad range of problems in the area.

Revisiting Harold Pinter’s The Caretaker: a Semiotic Study of the Dramatis Personae

2019 ◽  
Vol 16 (1B) ◽  
Author(s):  
Khaled Besbes
Keyword(s):  
Present Article ◽  
Analytical Method ◽  
Comprehensive Analysis ◽  
Positive Outcomes ◽  
Semiotic Analysis ◽  
Sign Systems ◽  
Semiotic Approach ◽  
Stage Props

Abstract: The present article sought to offer a semiotic analysis of Pinter’s The Caretaker’s characters as signifers in their own right. The article also aimed at studying the play’s dramatis personae as loci of multi-coded expressions, with a focus on the various modes of signifcation associated with them. Using semiotics as an analytical method, the author explored the linguistic and paralinguistic features of the characters’ discourses as signs in relation to the play’s pivotal themes, their kinesic and body expressions as indexical signs, as well as their distinctive proxemic behavior(s) onstage. Some attention was also given to the characters’ handling of stage props and the special meanings attached to them as replicators of character personality. The results of the discussion showed that using a semiotic approach to analyze The Caretaker’s characters can yield positive outcomes in terms of comprehensive analysis and interpretation of the characters as dynamic unities of interrelated sign-systems. Keywords: Pinter, semiotics, dramatis personae, linguistic, kinesic, proxemic

scholarly journals Performance of Norton Quantum Grinding Wheels

2016 ◽  
Vol 686 ◽  
pp. 125-130 ◽  
Author(s):  
Miroslav Neslušan ◽  
Jitka Baďurová ◽  
Anna Mičietová ◽  
Maria Čiliková
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Bearing Steel ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Removal Rates ◽  
Surface Burn ◽  
Conventional Grinding

This paper deals with cutting ability of progressive Norton Quantum grinding wheel during grinding roll bearing steel 100Cr6 of hardness 61 HRC. Cutting ability of this wheel is compared with conventional grinding wheel and based on measurement of grinding forces as well as surface roughness. Results of experiments show that Norton Quantum grinding wheels are capable of long term grinding cycles at high removal rates without unacceptable occurrence of grinding chatter and surface burn whereas application of conventional wheel can produce excessive vibration and remarkable temper colouring of ground surface. Moreover, while Norton Quantum grinding wheel gives nearly constant grinding forces and surface roughness within ground length at higher removal rates, conventional grinding wheel (as that reported in this study) does not.

The Three-Dimensional Surface Topographic Characterisation of Diamond Grinding Wheels

2010 ◽  
Vol 126-128 ◽  
pp. 690-695
Author(s):  
David Lee Butler
Keyword(s):  
Measurement Techniques ◽  
Three Dimensional ◽  
Surface Measurement ◽  
Grinding Wheel ◽  
Profile Measurement ◽  
Detailed Knowledge ◽  
Grinding Wheels ◽  
Diamond Grinding ◽  
Insight Into ◽  
Dimensional Surface

Surface measurement using three-dimensional stylus instruments is a relatively new technique that offers numerous advantages over more traditional profilometry methods. The information generated is, unlike profile measurement, less subjective and more statistical providing additional insight into the surface structure. One application of surface measurement that has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into surface interactions between the wheel and workpiece as well as enabling improved control of the grinding process in general. In this paper four diamond grinding wheels of 91 and 181 micron grit size were subjected to differing dressing conditions to produce varying final wheel topographies. Three-dimensional surface measurement techniques were employed to quantitatively characterise the topographic change and provide an aerial estimation of the number of cutting grains. The results demonstrate that the techniques can distinguish between a worn and dressed wheel. In addition, the parametric values generated from the various surfaces can aid the user in determining when re-dressing is required.

New Active Online Balancing Method for Grinding Wheel Using Liquid Injection and Free Dripping

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Xining Zhang ◽  
Xu Liu ◽  
Huan Zhao
Keyword(s):  
Grinding Wheel ◽  
Time Varying ◽  
Residual Liquid ◽  
Grinding Wheels ◽  
Abrasive Particles ◽  
Balance Condition ◽  
Liquid Injection ◽  
Grinding Machines ◽  
The Relationship

Grinding is a vital method in machining techniques and an effective way to process materials such as hardened steels and silicon wafers. However, as the running time increases, the unbalance of grinding wheels produce a severe vibration and noise of grinding machines because of the uneven shedding of abrasive particles and the uneven adsorption of coolant, which has a severe and direct impact on the accuracy and quality of parts. Online balancing is an important and necessary technique to reduce the unbalance causing by these factors and adjust the time-varying balance condition of the grinding wheel. A new active online balancing method using liquid injection and free dripping is proposed in this paper. The proposed online balancing method possesses a continuous balancing ability and the problem of losing balancing ability for the active online balancing method using liquid injection is solved effectively because some chambers are full of liquid. The residual liquid contained in the balancing chambers is utilized as a compensation mass for reducing rotor unbalance, where the rotor phase is proposed herein as a target for determining the machine unbalance. A new balancing device with a controllable injection and free dripping structure is successfully designed. The relationship between the mass of liquid in the balancing chamber and the centrifugal force produced by liquid is identified. The performance of the proposed method is verified by the balancing experiments and the results of these experiments show that the vibration of unbalance response is reduced by 87.3% at 2700 r/min.

scholarly journals INVESTIGATION OF THE PROCESS OF DOUBLE-SIDED GRINDING OF TORCHES OF PUSHERS WITH DIFFERENT DIAMETRERS

2018 ◽  
pp. 86-93
Author(s):  
Oleksandr Lytvyn ◽  
Kalchenko Dmytro Kalchenko
Keyword(s):  
Large Scale ◽  
Maximum Diameter ◽  
Grinding Wheel ◽  
Universal Method ◽  
Grinding Wheels ◽  
Processing Efficiency ◽  
Agricultural Engineering ◽  
Grinding Machines ◽  
Precision Of Processing ◽  
Different Diameters

Urgency of the research. In machine tools, automotive, agricultural engineering, manufacturing, where it is necessary to ensure high accuracy of surfaces of parts with different diameters of faces, it is required to adhere to high requirements for the quality of geometric sizes, roughness and accuracy of molding. Target setting. Grinding of end surfaces of parts with different diameters of faces, is carried out on two-sided end-grinding machines. The specific gravity of grinding in the total complexity of mechanical processing is constantly increasing and at the present stage it is about 30 % in the machine tool industry, in the automotive industry more than 38% of the total complexity of processing. Actual scientific researches and issues analysis. On the two-sided end-grinding machines of the Saturn company (Germany) the processing of round ends of parts is done with a circular feed to the processing area. Abrasive wheels are used without calibrating plots, which requires a lot of processing to obtain the required precision, which reduces the productivity of grinding. The disadvantage of the method is that the processing of parts with different face diameters is not considered. Uninvestigated parts of general matters defining. It is necessary to improve the processing efficiency of parts by developing the methods of two-sided polishing of the ends of pushers with different diameters oriented grinding wheels with and with-out calibrating sections, and also the rotation or without rotation of the workpiece on the calibration section, at least one revo-lution. The research objective. Improving the accuracy of finishing the end surfaces of parts of various diameters with grinding wheels, is achieved by the fact that the shaping of the ends of the smaller diameter is performed by the maximum diameter of the flat end of one circle, and the shaping of the end face of a larger diameter – the calibration section of the second circle, the length of which is equal to the diameter of the larger end and filled with diamond pencil, which moves along a radius, which coincides with the radius of the location of the axes of the parts in the feed drum. The statement of basic materials. In order to ensure the processing of parts in one pass and the necessary precision of processing, in large-scale and mass production, a grinding method oriented circles with calibrated sections with one-sided arrangement of ends of one diameter is used. The calibration sections are then made of different lengths, depending on the diameter, respectively, larger and smaller. Conclusions. The universal method of practical application of model of accuracy of shaping of ends of parts of different diameters, oriented grinding circles with and without calibration plots has been suggested. The presented method simplifies the grinding of the grinding wheel. It does not require special editing and allows to use regular editing.

scholarly journals A new motivation: the television in the school

Comunicar ◽  
2005 ◽  
Vol 13 (25) ◽  
Author(s):  
Ana-Luisa Fernandes-Gonçalves
Keyword(s):  
Present Article ◽  
The Internet ◽  
Complex World ◽  
Critical Attitude ◽  
Know How ◽  
The Third ◽  
World Today ◽  
The Family ◽  
The World ◽  
Excessive Consumption

The present article is about the presence of the tv in the society, in general, and its potential as an important agent, such as the family and the school, on the children’s and young people’s development and education. Nowadays we live in a complex world of images with sound, the most of them transmitted by the tv, the cinema and the internet. The infantile universe is full of those images. This way we structured this article in four parts, refering some of the contents related with this subject. The first part describes the presence of the television in the children's daylife and their relationship with the magic box, even the identification that they make with its favourites characters, in order to understand the space that the TV occupies in their lives. The second part presents the different messages transmitted by the television. It is important to analyze the main risks and advantages of television, that is to say, in spite of some programs show bad values, foment the excessive consumption, expose the children to an atmosphere of violence and pornography, also entertains, accompanies, educates, informs, favours the access to the culture and allows to unite the family around a program. At last the third part, this one outlines the necessity to put the tele as a curricular resource in the school, to teaches the students how to analyze, how to criticize and to think about the texts and the news of the world today. The television, considered a powerful tool, is decisive in the communication, such in the formation of values and ideas as in the culture transmission. The function of the school is not to remain far from this factor, but to try to meditate, to understand and to decide its impact, in a better way, on the development of the children and youngs. As conclusion we can add that we’ve tried to aim some strategies that educators and parents will be able to work, united to the children and the youngs, so they could have a new look of the Tv’s world and that they could know how to make their own selection and how to have a critical attitude before the watched product.La presente comunicación se refiere a la presencia de la tele en la sociedad en general y a su potencial como agente importante de formación y educación, junto con la escuela y la familia, en la vida de los niños y de los jóvenes. Actualmente vivimos inmersos en un mundo complejo de imágenes con sonido, que recibimos muy especialmente a través de la tele, del cine y de Internet, los cuales hacen parte del cotidiano del universo infantil. Así, a fin de organizar algunos de los contenidos desde los que es posible enfocar el tema, estructuramos este artículo en cuatro partes. La primera parte describe la presencia de la tele a diario de los niños y su relación con la caja mágica, incluso la identificación que hacen de sus personajes favoritos, a fin de comprender el espacio que ocupa la tele en su cotidianidad. La segunda parte presenta los distintos mensajes transmitidos por la tele. Es importante analizar las principales riesgos y ventajes de la televisión, o sea, a pesar de algunos programas muestran antivalores de la tele: fomentar excesivamente el consumo, exponer a los niños a un ambiente de violencia y pornografía también entretiene, acompaña, educa, informa, favorece el acceso a la cultura y permite unir a la familia en torno a un programa. Cuanto a la tercera parte, plantea la necesidad de incorporar la tele como recurso curricular en la escuela, para que enseñe a los alumnos a analizar crítica y reflexivamente los textos mediáticos. La televisión es considerada como una herramienta poderosa, determinante en la comunicación, tanto en la formación de valores e ideas, como en la transmisión de cultura; la función de la escuela no es permanecer ajena a este factor, pero procurar reflexionar para comprender y decidir mejor su impacto en el desarrollo de los niños y jóvenes. Como conclusión podemos añadir que hemos tratado de apuntar algunas estrategias que educadores y padres podrán trabajar junto con los niños y los jóvenes, para que éstes tengan una nueva mirada del mundo de la tele y para que sepan hacer su propia selección y tener una actitud crítica ante el producto visionado.

Development of Vitrified Bond CBN Wheel for Internal Precision Grinding of the Air-Conditioner Compressor Piston Hole

2006 ◽  
Vol 304-305 ◽  
pp. 29-32 ◽  
Author(s):  
Hang Gao ◽  
Y.G. Zheng ◽  
W.G. Liu ◽  
Jian Hui Li
Keyword(s):  
Cost Effective ◽  
Grinding Wheel ◽  
Manufacturing Cost ◽  
Air Conditioner ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Grinding Performance ◽  
Compressor Piston ◽  
Vitrified Bond ◽  
Cbn Grinding Wheel

Manufacturing of vitrified bond CBN wheels for internal precision grinding of the air-conditioner compressor piston hole is still big challenge to all of the domestic manufacturers. Recently, by choosing pre-melting mixed CBN abrasives and a proper sintering process, a cost-effective method was conceived to produce grinding wheels of comparative quality. The grinding performance of wheels was evaluated with a series of internal precision grinding of compressor piston hole. Experimental results show that the vitrified bond CBN grinding wheel produced by this method has better grinding performance, and can be substitute to the same type of grinding wheels imported. But the manufacturing cost is only 60% of the wheel imported according to estimation.

Automation of calculations of cutting modes taking into account the wear of cubic boron nitride tools when applying solid lubricants

2021 ◽  
pp. 67-70
Author(s):  
Keyword(s):  
Boron Nitride ◽  
High Speed ◽  
Solid Lubricant ◽  
Cubic Boron Nitride ◽  
High Speed Steel ◽  
Solid Lubricants ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Ceramic Bond ◽  
Calculation System

The effect of a solid lubricant on the wear of cubic boron nitride grinding wheels on a ceramic bond of different hardness and grain size in the processing of high-speed steel is investigated. The dependences of the change in the wear of cubic boron nitride on the parameters of the processing mode are determined. An automated calculation system is proposed to control the consumption of cubic boron nitride grinding wheels in production conditions. Keywords: solid lubricant, grinding, high speed steel, cubic boron nitride grinding wheel, consumption, wear, grinding mode. [email protected]

scholarly journals Internal Cylindrical Grinding Process of INCONEL® Alloy 600 Using Grinding Wheels with Sol–Gel Alumina and a Synthetic Organosilicon Polymer-Based Impregnate

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 115 ◽  
Author(s):  
Wojciech Kapłonek ◽  
Krzysztof Nadolny ◽  
Krzysztof Rokosz ◽  
Jocelyne Marciano ◽  
Mozammel Mia ◽  
...  
Keyword(s):  
Sol Gel ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Alloy 600 ◽  
Abrasive Tool ◽  
Grinding Wheels ◽  
Impregnation Process ◽  
Organosilicon Polymer ◽  
Internal Cylindrical Grinding ◽  
Abrasive Tools

The development of modern jet engines would not be possible without dynamically developed nickel–chromium-based superalloys, such as INCONEL® The effective abrasive machining of above materials brings with it many problems and challenges, such as intensive clogging of the grinding wheel active surface (GWAS). This extremely unfavorable effect causes a reduction in the cutting ability of the abrasive tool as well as increase to grinding forces and friction in the whole process. The authors of this work demonstrate that introduction of a synthetic organosilicon polymer-based impregnating substance to the GWAS can significantly improve the effects of carrying out the abrasive process of hard-to-cut materials. Experimental studies were carried out on a set of a silicon-treated small-sized sol–gel alumina 1-35×10×10-SG/F46G10VTO grinding wheels. The set contained abrasive tools after the internal cylindrical grinding process of INCONEL® alloy 600 rings and reference abrasive tools. The condition of the GWAS after the impregnation process was studied, including imaging and measurements of its microgeometry using confocal laser scanning microscopy (CLSM), microanalysis of its elemental distribution using energy dispersive X-ray fluorescence (EDXRF), and the influence of impregnation process on the grinding temperature using infrared thermography (IRT). The obtained results confirmed the correctness of introduction of the impregnating substance into the grinding wheel structure, and it was possible to obtain an abrasive tool with a recommended characteristic. The main favorable features of treated grinding wheel concerning the reduction of adhesion between the GWAS and grinding process products (limitation of the clogging phenomenon) as well as reduction of friction in the grinding process, which has a positive effect on the thermal conditions in the grinding zone.

Research on Grinding Temperature of Nano ZrO2 Ceramics Using Diamond Grinding Wheel Dressed by Elliptic Ultrasonic Vibration

2010 ◽  
Vol 42 ◽  
pp. 313-316 ◽  
Author(s):  
Jin Xue Xue ◽  
Bo Zhao
Keyword(s):  
Comparative Analysis ◽  
Ceramic Material ◽  
Ultrasonic Vibration ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Grinding Wheels ◽  
Vibration Method ◽  
Diamond Grinding Wheel ◽  
Diamond Grinding

In order to investigate the influence of dressing methods on grinding temperature, two kinds of diamond grinding wheels dressed by traditional dressing(TD) and elliptic ultrasonic vibration dressing(ED) respectively were used to grind the same nano-ceramic material. Through grinding experiments, the comparative analysis of the grinding temperature was conducted. The results show that diamond grinding wheel dressed by elliptical ultrasonic vibration method can decrease the grinding temperature.

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