Vibrations of Flexible Precision Grinding Spindles

1959 ◽  
Vol 81 (3) ◽  
pp. 201-205 ◽  
Author(s):  
R. S. Hahn
Keyword(s):  
Grinding Wheel ◽  
Precision Grinding ◽  
Wheel Wear ◽  
Normal Forces ◽  
Gyroscopic Effects ◽  
Subharmonic Resonances

The effects of pulsating forces between grinding wheel and workpiece are discussed in connection with inhomogeneous wheel wear and loading. By analysis it is shown that pulsating normal forces may be caused by rotary damping and gyroscopic effects. The influence of skew-symmetric rigidity in the spindle is also discussed and the occurrence of subharmonic resonances is pointed out.

An Intelligent Prediction of Surface Roughness on Precision Grinding

2017 ◽  
Vol 261 ◽  
pp. 221-225
Author(s):  
Ning Ding ◽  
Chang Long Zhao ◽  
Xi Chun Luo ◽  
Qing Hua Li ◽  
Yao Chen Shi
Keyword(s):  
Surface Roughness ◽  
Prediction Model ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Precision Grinding ◽  
Wheel Wear ◽  
Surface Roughness Prediction ◽  
Fuzzy Neural ◽  
Roughness Prediction ◽  
Wear Condition

Precision grinding is generally used as the final finishing process, and it determines the surface quality of the machined component. It’s very difficult to achieve on-line measurement of the surface roughness. The purpose of this research was to study the surface roughness prediction and avoid the defect happening in the grinding process. A surface roughness prediction model was proposed in this paper, which presented the relationship between surface roughness and the wear condition of grinding wheel and grinding parameters. An AE sensor was used to collect the grinding signals during the grinding process to obtain the grinding wheel wear condition. Besides, a fuzzy neural network was used to obtain the prediction surface roughness. Grinding trials were performed on a high precision CNC cylindrical grinder (MGK1420) to evaluate the surface roughness prediction model. Experiment verified that the developed prediction system was feasible and had high prediction accuracy.

Precision Grinding Characteristics and Process Optimization on YG3 Cemented Carbide

2012 ◽  
Vol 602-604 ◽  
pp. 1971-1974
Author(s):  
Xun Kun Liang ◽  
Zhi Jian He
Keyword(s):  
Surface Roughness ◽  
Process Optimization ◽  
Rotation Speed ◽  
Research Result ◽  
Cemented Carbide ◽  
Grinding Wheel ◽  
Precision Grinding ◽  
Wheel Wear ◽  
Grinding Parameters ◽  
Hard And Brittle Materials

Precision grinding experiment and process optimization of YG3 cemented carbide materials was conducted with various grinding parameters using resin-bonded diamond grinding wheel. Different rotation speed of workpiece, feed rate and grinding depth were chozen in precision cross grinding. Surface roughness was measured for studying the removal mode and grinding charateristics. A set of ideal grinding parameters of YG3 cemented carbide were obtained by changing the process parameters. The research result has guiding significance for reducing the wheel wear and processing costs, improving grinding quality and efficiency while precision grinding hard and brittle materials.

The Wear of Grinding Wheels: Part 2—Fracture Wear

1971 ◽  
Vol 93 (4) ◽  
pp. 1129-1133 ◽  
Author(s):  
S. Malkin ◽  
N. H. Cook
Keyword(s):  
Wear Particle ◽  
Grinding Wheel ◽  
Wear Particles ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Grinding Forces ◽  
Wheel Wear ◽  
Important Form

The nature and extent of grinding wheel wear in precision grinding were investigated directly from the wear particles removed from the wheel. A statistical analysis of the wear particle size distributions was developed to determine the relative amounts of bond fracture, grain fracture, and attritious wear. Most of the wear consists of grain and bond fracture particles with relatively more bond fracture occurring with softer wheels. The rate at which fracture wear occurs is directly related to the grinding forces and the amount of binder in the wheel. The attritious wear, although contributing insignificantly to the total, is the most important form of wear as it is directly related to the size of the wear flats, grinding forces, and workpiece burn, and therefore controls grain and bond fracture wear.

Calculation of Effective Ground Depth of Cut by Means of Grinding Process Model

2011 ◽  
Vol 496 ◽  
pp. 7-12 ◽  
Author(s):  
Takazo Yamada ◽  
Michael N. Morgan ◽  
Hwa Soo Lee ◽  
Kohichi Miura
Keyword(s):  
Process Model ◽  
Ground Surface ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wheel Wear ◽  
Elastic Deformations ◽  
Proposed Model ◽  
Effective Depth ◽  
Grinding Machine

In order to obtain the effective depth of cut on the ground surface, a new grinding process model taking into account thermal expansions of the grinding wheel and the workpiece, elastic deformations of the grinding machine, the grinding wheel and the workpiece and the wheel wear was proposed. Using proposed model, the effective depth of cut was calculated using measured results of the applied depth of cut and the normal grinding force.

Design on High-Speed Precision Grinder

2006 ◽  
Vol 304-305 ◽  
pp. 492-496 ◽  
Author(s):  
Yu Hou Wu ◽  
L.X. Zhang ◽  
Ke Zhang ◽  
Song Hua Li
Keyword(s):  
High Speed ◽  
Servo Control ◽  
Grinding Wheel ◽  
Control Technology ◽  
Precision Grinding ◽  
Spindle Unit ◽  
Central Controller ◽  
High Speed Grinding ◽  
Dynamic Performances ◽  
Feed Unit

As one of the modern manufacture technology, high-speed precision grinding takes an important part in the modern manufacture field. With the development of the technology on high-speed spindle unit, linear precision high-speed feed unit, manufacture of grinding wheel, measurement etc, a great deal of research achievements make it possible for high-speed precision grinding. In this paper, using PMAC (Programmable Multi-Axis Controller)—PC as the central controller, a new kind of high-speed precision grinder is designed and manufactured. The servo control technology of linear motor is investigated. The dynamic performances of the machine are analyzed according to the experimental results. Elliptical workpieces have been machined with this new high-speed precision grinder. Based on these research results, a very helpful approach is provided for the precision grinding of complicated workpieces, and these results promote the development of high speed grinding too.

Development of Electroplated CBN Wheel with Cemented Carbide Base for Precision Grinding of Compressor Cylinder Vane Slot

2007 ◽  
Vol 329 ◽  
pp. 495-500
Author(s):  
Hang Gao ◽  
W.G. Liu ◽  
Y.G. Zheng
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Cemented Carbide ◽  
Grinding Wheel ◽  
Precision Grinding ◽  
Base Surface ◽  
Compressor Cylinder ◽  
Cbn Wheel ◽  
Micro Holes ◽  
Ground Surface Roughness

It is experimentally found that existing micro-holes or micro-concaves on the cemented carbide base surface of electroplated CBN wheel is one of important reasons to worsen the combining intensity of the electroplated abrasives layer with the grinding wheel base. It is well solved by sealing the holes or concaves with steam sealing method. Further more the electroplated CBN wheel with cemented carbide base for precision grinding of compressor cylinder vane slot is developed by optimizing the electroplating prescription and process. Productive grinding results show that the ground surface roughness, size precision and the wheel life have reached the advanced index of the same type of wheel imported.

scholarly journals Grinding of AISI 4340 steel with interrupted cutting by aluminum oxide grinding wheel

2015 ◽  
Vol 68 (2) ◽  
pp. 229-238
Author(s):  
Hamilton Jose de Mello ◽  
Diego Rafael de Mello ◽  
Eduardo Carlos Bianchi ◽  
Paulo Roberto de Aguiar ◽  
Doriana M. D'Addona
Keyword(s):  
Aluminum Oxide ◽  
Rotation Speed ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wheel Wear ◽  
Machined Surface ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Grinding Machine ◽  
Aisi 4340

AbstractThere has been a great advance in the grinding process by the development of dressing, lubri-refrigeration and other methods. Nevertheless, all of these advances were gained only for continuous cutting; in other words, the ground workpiece profile remains unchanged. Hence, it becomes necessary to study grinding process using intermittent cutting (grooved workpiece – discontinuous cutting), as little or no knowledge and studies have been developed for this purpose, since there is nothing found in formal literature, except for grooved grinding wheels. During the grinding process, heat generated in the cutting zone is extremely high. Therefore, plenty of cutting fluids are essential to cool not only the workpiece but also the grinding wheel, improving the grinding process. In this paper, grinding trials were performed using a conventional aluminum oxide grinding wheel, testing samples made of AISI 4340 steel quenched and tempered with 2, 6, and 12 grooves. The cylindrical plunge grinding was performed by rotating the workpiece on the grinding wheel. This plunge movement was made at three different speeds. From the obtained results, it can be observed that roughness tended to increase for testing sample with the same number of grooves, as rotation speed increased. Roundness error also tended to increase as the speed rotation process got higher for testing the sample with the same number of grooves. Grinding wheel wear enhanced as rotation speed and number of grooves increased. Power consumed by the grinding machine was inversely proportional to the number of grooves. Subsuperficial microhardness had no significant change. Micrographs reveal an optimal machining operation as there was no significant damage on the machined surface.

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.

Research on the 3-Axis CNC Ultra-Precision Grinding of Aspheric Mould

2009 ◽  
Vol 69-70 ◽  
pp. 39-43 ◽  
Author(s):  
Li Jun Li ◽  
Fei Hu Zhang ◽  
Shen Dong
Keyword(s):  
Influence Factors ◽  
Grinding Wheel ◽  
Aspheric Surface ◽  
Precision Grinding ◽  
Form Accuracy ◽  
Form Errors ◽  
Machining Test ◽  
Ultra Precision ◽  
Grinding System ◽  
Parallel Grinding

Parallel grinding is an effective method of aspheric moulds machining which is usually made of industrial ceramic such as silicon carbide (SiC) or tungsten carbide (WC), but if the spherical grinding wheel is not being with precision truing and dressing, the roughness and form accuracy of the ground aspheric surface should get worse, for this reason, in this paper, the influence factors of thoroughness and form accuracy induced by the wheel truing and dressing are studied firstly, and a new 3-axis CNC Ultra-precision grinding system which is based on the PMAC (Programmable Multi-axes Controller) is developed, through simultaneous motion of the controlled X, Z and B axis, the form errors which is induced by the grinding wheel can be improved theoretically, and the aspheric mould machining test shown that the surface roughness of Ra 0.025μm and the form accuracy of P-V 1.15μm are achieved.

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