scholarly journals Calculating the profile of intermittent grinding wheel for the sharpening teeth of the broach

2018 ◽  
Vol 224 ◽  
pp. 01003
Author(s):  
Vladimir Bogutsky ◽  
Yurij Novoselov ◽  
Leonid Shron
Keyword(s):  
Metal Cutting ◽  
Cutting Tools ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Discontinuous Surface ◽  
Thermodynamic Conditions ◽  
Cutting Zone ◽  
Grinding Operations ◽  
Process Productivity

The article shows that during the grinding of complex profile blades of metal cutting tools from tool steels, unfavorable thermodynamic conditions are created in the cutting zone and, as a result, grinding burns and cracks occur on the surface of the polished workpiece. One of the methods of controlling the temperature in the cutting zone at the final grinding operations is the use of grinding wheels with a discontinuous surface. The method of calculating the profile of the discontinuous surface of the grinding wheel presented in the article makes it possible to determine its geometric parameters taking into account the wear resistance of the grinding wheel and the heat stress of the process of treatment. The results of the verification of the proposed technique in the production conditions are given which showed that the treatment of the teeth of the broaches with a grinding wheel with a discontinuous profile, in comparison with the machining of broaches according to the traditional technology, provides a higher quality of blade surfaces, while the process productivity, compared with the factory technology, increased by 20...26%.

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.

Effect of the Coolant Lubricant Type and Dress Parameters on CBN Grinding Wheels Performance

2009 ◽  
Vol 76-78 ◽  
pp. 163-168 ◽  
Author(s):  
Taghi Tawakoli ◽  
Abdolreza Rasifard ◽  
Alireza Vesali
Keyword(s):  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Workpiece Surface ◽  
Vitrified Cbn

The efficiency of using of CBN grinding wheels highly depends on the dressing process as well as on the coolant lubricant used. The Institute of Grinding and Precision Technology (KSF) investigated the performance of vitrified CBN grinding wheels -being dressed using different parameters- while using two different grinding oils and two different water-miscible coolant lubricants. The obtained results show that the performance of the vitrified CBN grinding wheels regarding the quality of the workpiece surface, the grinding forces as well as the wear of the grinding wheel, highly depend on the dressing conditions and the type of the coolant lubricant used. Compared to the water-miscible coolant lubricants, the grinding oils show better results.

Finishing Methods of Tools Functional Surfaces

2013 ◽  
Vol 581 ◽  
pp. 18-21
Author(s):  
Imrich Lukovics ◽  
Jiří Čop
Keyword(s):  
Residual Stress ◽  
Cutting Tools ◽  
Grinding Wheels ◽  
Rotating Disc ◽  
Functional Surfaces ◽  
Machining Speed

Article shows the calculation of the stress in a rotating disc and the possibility of using proprietary forms of instruments for speed grinding. It presents the results of speed and efficient cutting tools in machining these materials alloyed with chromium. In addition, it notes the results of the influence of technological conditions on the quality of surfaces, the residual stress in the workpiece, resulting from the machining speed and the influence of technological conditions on the wear of grinding wheels. Finally, some options for the use of finishing techniques in practice are mentioned.

An Investigation of Grinding Wheel Cutting Edges

1964 ◽  
Vol 86 (4) ◽  
pp. 371-382 ◽  
Author(s):  
H. Tsuwa
Keyword(s):  
Electron Microscope ◽  
Microscopic Observation ◽  
Phase Contrast ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Abrasive Grains ◽  
Contrast Microscope ◽  
New Apparatus ◽  
Grinding Operations ◽  
Dressing Action

A new apparatus for microscopic observation and tracing of cutting edges of a wheel has been developed. The use of this apparatus allows us to visually witness the behavior of abrasive grains during the grinding operation. A phase-contrast microscope, as well as an electron microscope has been used with the new apparatus in this investigation. A method of calculating effective grain spacing to show distribution of cutting edges, as well as the cutting edge ratio to known worn conditions of grains has been completed. These aforementioned values for various grinding wheels have been studied in grinding operations and the changing aspects of them have been noted. Through these experiments, we have had helpful suggestions about grinding mechanisms; there is no self-dressing action of grains in the usual grinding work; sliding of the cutting edges takes place in the grinding, and wear of the grinding is increased by this action.

Effect of the Grinding Oil Type on CBN Grinding Wheels Performance

2009 ◽  
Author(s):  
Taghi Tawakoli ◽  
Abdolreza Rasifard ◽  
Alireza Vesali
Keyword(s):  
Heat Resistance ◽  
Surface Quality ◽  
Grinding Wheel ◽  
Work Piece ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Vitrified Cbn ◽  
Oil Type

The efficiency of the grinding process highly depends on the coolant lubricant used. In grinding with CBN grinding wheels grinding oils are used increasingly. In the last decade new grinding oils based on different oil types are brought into the market, whose effect on the CBN grinding wheels performance until now not sufficiently been investigated. The Institute of Grinding and Precision Technology (KSF) investigated the influence of four different grinding oils on the performance of vitrified CBN grinding while grinding of 100Cr6 (M.-No. 1.3505), which is a heat-treatable steel with a very good grindability, and Nimonic A80, which is a difficult to grind heat-resistance superalloy. The obtained results show that the performance of the vitrified CBN grinding wheels—while using grinding oil as coolant lubricant—regarding the quality of the work piece surface, the grinding forces as well as the wear of the grinding wheel, highly depend on the viscosity of the grinding oil. Moreover, the results show that the surface quality and the grinding forces while using different grinding oils depend significantly on the work piece material.

scholarly journals THE EFFECT OF TEMPERATURE ON THE GRINDING SURFACE QUALITY RING ROLLER

2019 ◽  
pp. 58-62
Author(s):  
Марчук В.І. ◽  
Джугурян Т.Г. ◽  
Марчук І. В. ◽  
Сачковська Л. О.
Keyword(s):  
Roughness Parameter ◽  
Response Surfaces ◽  
Effect Of Temperature ◽  
Grinding Wheel ◽  
Surface Band ◽  
Narrow Strip ◽  
Grinding Operations ◽  
Grinding Power ◽  
Experimental Researches

A series of experimental researches was carried out in the work, which confirmed the results of modeling of temperature processes in the zone of centerless intermittent grinding of billet rings. The constructed response surfaces of the dependence of the roughness parameter Ra on the grinding modes and the number of grooves of the grinding wheel form the basis of the developed technique for designing grinding operations and tool adjustments of grinding machines. The contact area of ​​the abrasive circle with the workpiece is a narrow strip of rectangular shape that moves along the workpiece surface. In this case, the temperature field can be calculated according to the scheme of a moving infinitely long surface-band source. The plan, the program and the hardware of experimental researches of the connection of design and technological factors and indicators of grinding operations with parameters of quality of grinding surfaces, temperature of grinding, power parameters of the process of grinding by discontinuous grinding circles and constructive circles have been developed.

scholarly journals New Abrasive Materials and Their Influence on the Surface Quality of Bearing Steel After Grinding

10.14311/1598 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Ondrej Jusko
Keyword(s):  
Surface Quality ◽  
Bearing Steel ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Abrasive Material ◽  
Abrasive Grains ◽  
Measurement Results ◽  
New Type

This paper focuses on the influence of various types of abrasive grains on cutting properties during the grinding process for bearing steel. In this experiment, not only conventional super-hard abrasive materials but also a new type of abrasive material were employed in grinding wheels. The measurement results were compared, and an evaluation was made of the cutting properties of the new abrasive material. The options were then evaluated for their practical applicability. The measurement results indicated that a grinding wheel with Abral and SG grains is the most suitable for grinding hardened bearing steel in order to achieve the best roughness and geometrical accuracy.

Evaluation of Single Layer Hafnium Nitride Coated Tool for Metal Cutting

2016 ◽  
Vol 1815 ◽  
Author(s):  
John Henry Navarro Devia ◽  
Willian Aperador Chaparro ◽  
Jairo Cortes Lizarazo
Keyword(s):  
Tool Wear ◽  
Metal Cutting ◽  
Cutting Tools ◽  
High Speed Steel ◽  
Single Layer ◽  
Numerical Control ◽  
Process Time ◽  
Work Piece ◽  
Hafnium Nitride

ABSTRACTThe main purpose of coatings is to increase the lifetime of cutting tools, to perform continuous and economical material removal process, reducing the frequency of sharpening or replacement of the tool, which contributes to increase quality of product. Therefore, hafnium nitride (HfN) single layer coatings were deposited on High-speed steel by Magnetron Sputtering physical vapour deposition (PVD). The machining on AISI 1020 steel samples were carried out in a computer numerical control (CNC) machine, using coated and uncoated tools, the temperature of the different components were measured (steel bar and tool), due to continuous temperature measurement help to predict tool wear and the quality of finished piece [1] . In order to evaluate wear resistance and performance, not only temperature data were compared, the tool wear morphological analysis for flank wear was carried using Scanning Electron Microscopy (SEM), and work pieces roughness were checked through their surfaces in an Atomic Force Microscopy (AFM). In most of the parameters evaluated differences between the tools were identified, and results reveals that on HfN coating, occurs less wear, due the proportionality between the energy transfer and the tool deterioration, also the coating improves surface finish of the machined part; all of them are reflected in changes on process temperatures. The use of single layer HfN coating on cutting tools could increase their lifetime, improve the quality of the work piece, and even reduce process time and cost.

Methods of Considering Reliability in the Quality Evaluation Procedure for Composite Metal Cutting Tools

2015 ◽  
Vol 770 ◽  
pp. 216-220 ◽  
Author(s):  
E.V. Artamonov ◽  
D.S. Vasilega ◽  
M.S. Ostapenko
Keyword(s):  
Metal Cutting ◽  
Quality Evaluation ◽  
Cutting Tools ◽  
Cutting Edge ◽  
Evaluation Procedure ◽  
Processed Material ◽  
Thermal Compatibility ◽  
Take All

In terms of method for evaluating the quality of composite metal cutting tools, a need to regard reliability as a factor, consisting of several components, is grounded. It is discovered, that thermal compatibility of processed material and material of the tool, has a significant impact on composite cutters’ durability. So does the force of stress, created in the cutting edge. In order to take all these factors into account when evaluating the quality of metal cutting tools, the need to include stress and thermal compatibility coefficients has been proven. Means to determine the attributes needed and formulas for calculation of those coefficients had been developed. The methods we created can be used for the evaluation of both the existing tools and for the perspective tools currently being developed.

scholarly journals Research of working capacity of grinding wheels

2018 ◽  
Vol 224 ◽  
pp. 01005
Author(s):  
Tatyana N. Ivanova
Keyword(s):  
Temperature Field ◽  
Operation Mode ◽  
Grinding Wheel ◽  
Abrasive Tool ◽  
Working Capacity ◽  
Grinding Wheels ◽  
Temperature Stresses ◽  
Heating And Cooling ◽  
Abrasive Grain

The processing of materials by cutting with abrasive tool is carried out by means of thousands of grains bonded together as a single whole. The quality of abrasive tool is defined by cutting properties of abrasive grains and depends on features of spreading of temperature field in time and in abrasive grain volume. Grains are exposed to heating and cooling during work. It leads to undesired effects such as decrease of durability of grain retention in the binder, hardness, intensification of diffusion and oxidation processes between the binder and grain, the occurrence of considerable temperature stresses in the grain itself. Obtained equation which allows calculation of temperature field of grain for one rotation of grinding wheel shows that the temperature of the wheel depends on grinding modes and thermophysical properties of abrasive material. Recommendations for working capacity of grinding wheels in each operation mode and with a transition from one mode to another are given. As a result of research different dependencies were determined. They include dependencies governing the extent of influence of granularity, difference in height and concentration of grains, geometry parameters of detail to be machined and grinding wheel on machining modes and the thickness of layer cutoff by one grain.

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