Kinematics Simulation of Grinding Process Based on Virtual Wheel Model and Micro-Cutting Analysis

Author(s):  
Xuekun Li ◽  
Yiming Kevin Rong

Grinding is a special machining process with large number of parameters influencing each other. Any grinding process involves six basic microscopic wheel-workpiece interaction modes in terms of grain cutting, plowing, and sliding, as well as bond-workpiece friction, chip-workpiece friction, and chipbond friction. And quantification of all the 6 modes immensely enhances understanding and managing of the grinding processes. In this paper, the kinematics simulation is presented to imitate the grinding wheel surface moving against the workpiece under specified grinding conditions. The grinding wheel surface is imported from the fabrication analysis based grinding wheel model of previous work. During each simulation iteration step, it provides the number of contacting grains, contact cross-section area for each grain, and resultant workpiece surface condition. Through retrieving the specific force value from the single grain cutting simulation, the cutting force and plowing force can be calculated. This model can also be potentially used in the time dependent behavior and thermal analysis of grinding processes.

2022 ◽  
Vol 16 (1) ◽  
pp. 12-20
Author(s):  
Gen Uchida ◽  
Takazo Yamada ◽  
Kouichi Ichihara ◽  
Makoto Harada ◽  
Tatsuya Kohara ◽  
...  

In the grinding process, the grinding wheel surface condition changes depending on the dressing conditions, which affects the ground surface roughness and grinding resistance. Several studies have been reported on the practical application of dressing using prismatic dressers in recent years. However, only a few studies that quantitatively evaluate the effects of differences in dressing conditions using prismatic dresser on the ground surface roughness and grinding resistance have been reported. Thus, this study aims to evaluate quantitatively the effect of the difference in dressing conditions using the prismatic dresser on the ground surface roughness and grinding resistance by focusing on the dressing resistance. In the experiment, dressing is performed by changing the dressing lead and the depth of dressing cut with a prismatic dresser, and the ground surface roughness and grinding resistance are measured. Consequently, by increasing the dressing lead and the depth of dressing cut, the ground surface roughness increased, and the grinding resistance decreased. This phenomenon was caused by the increase in dressing resistance when the dressing lead and the depth of dressing cut were increased, which caused a change in the grinding wheel surface condition. Furthermore, the influence of the difference in dressing conditions using the prismatic dresser on the ground surface roughness and grinding resistance can be quantitatively evaluated by using the dressing resistance.


2005 ◽  
Vol 291-292 ◽  
pp. 67-72 ◽  
Author(s):  
M. Ota ◽  
T. Nakayama ◽  
K. Takashima ◽  
H. Watanabe

There are strong demands for a machining process capable of reducing the surface roughness of sliding parts, such as auto parts and other components, with high efficiency. In this work, we attempted to grind hardened steel to a mirror-like surface finish with high efficiency using an ultra-high speed grinding process. In the present study, we examined the effects of the work speed and the grinding wheel grain size in an effort to optimize the grinding conditions for accomplishing mirror-like surface grinding with high efficiency. The results showed that increasing the work speed, while keeping grinding efficiency constant, was effective in reducing the work affected layer and that the grinding force of a #200 CBN wheel was lower than that of a #80 CBN wheel. Based on these results, a high-efficiency grinding step with optimized grinding conditions was selected that achieved excellent ground surface quality with a mirror-like finish.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Feng ◽  
Bin Yao ◽  
BinQiang Chen ◽  
DongSheng Zhang ◽  
XiangLei Zhang ◽  
...  

Interaction of process and machine in grinding of hard and brittle materials such as cemented carbide may cause dynamic instability of the machining process resulting in machining errors and a decrease in productivity. Commonly, the process and machine tools were dealt with separately, which does not take into consideration the mutual interaction between the two subsystems and thus cannot represent the real cutting operations. This paper proposes a method of modeling and simulation to understand well the process-machine interaction in grinding process of cemented carbide indexable inserts. First, a virtual grinding wheel model is built by considering the random nature of abrasive grains and a kinematic-geometrical simulation is adopted to describe the grinding process. Then, a wheel-spindle model is simulated by means of the finite element method to represent the machine structure. The characteristic equation of the closed-loop dynamic grinding system is derived to provide a mathematic description of the process-machine interaction. Furthermore, a coupling simulation of grinding wheel-spindle deformations and grinding process force by combining both the process and machine model is developed to investigate the interaction between process and machine. This paper provides an integrated grinding model combining the machine and process models, which can be used to predict process-machine interactions in grinding process.


2015 ◽  
Author(s):  
Arunachalam Narayanaperumal ◽  
Vijayaraghavan Lakshmanan

The surface quality of the ground components mainly depends on the surface condition of the grinding wheel. The surface condition of the grinding wheel changes with grinding time due to wheel wear and loading. The excessive wear and loading increases the cutting force and the temperature. This in turn affects the quality of the produced component. Hence periodic monitoring of the grinding wheel surface is essential to avoid the production of the defective components. In this paper, an attempt is made to study the changes in the grinding wheel surface condition using the laser scattered images. The simple speckle imaging arrangement is fabricated and fitted into the grinding machine to capture the images of the grinding wheel after each 100 passes. The fresh wheel expected to scatter more light due to higher roughness and porosity. On the other hand, the completely glazed and worn-out wheel scatters the light less due to smoother surface. Thus, speckle image intensity distribution captures the changes in the grinding wheel surface condition. The optical parameters evaluated from the speckle images clearly indicating the changes in the grinding wheel condition. This method can be utilized to evaluate the grinding wheel condition to improve the surface quality of the component produced.


2018 ◽  
Vol 148 ◽  
pp. 09004
Author(s):  
Paweł Lajmert ◽  
Małgorzata Sikora ◽  
Dariusz Ostrowski

In the paper, chatter vibrations in the cylindrical plunge grinding process are investigated. An improved model of the grinding process was developed which is able to simulate self-excited vibrations due to a regenerative effect on the workpiece and the grinding wheel surface. The model includes a finite-element model of the workpiece, two degrees of freedom model of the grinding wheel headstock and a model of wheel-workpiece geometrical interferences. The model allows to studying the influence of different factors, i.e. workpiece and machine parameters as well as grinding conditions on the stability limit and a chatter vibration growth rate. At the end, simulation results are shown and compared with exemplified real grinding results.


1999 ◽  
Vol 121 (4) ◽  
pp. 632-637 ◽  
Author(s):  
Xun Chen ◽  
W. Brian Rowe ◽  
D. R. Allanson ◽  
B. Mills

The grinding power is often used as a parameter for monitoring the grinding process. The power may also be used to monitor the effects of dressing. Empirical models are required to guide the selection of the dressing and grinding conditions. In this paper, the effects of dressing conditions and grinding conditions on grinding force and grinding power are reviewed. The effects of grinding conditions and dressing conditions on grinding force and grinding power are related to the shape of the idealized chip thickness. It is found that the grinding force and grinding power can be related to the dressing operation by considering the effective density of the cutting edges on the wheel surface. The semi-empirical model developed in this paper can be used to predict the variation of the grinding power during the wheel redress life cycle. Therefore the model can be used to guide the selection of dressing and grinding conditions. The potential use of the model for adaptive control of the grinding process is also described.


2016 ◽  
Vol 874 ◽  
pp. 395-400
Author(s):  
Jumpei Kusuyama ◽  
Takayuki Kitajima ◽  
Akinori Yui ◽  
Toshihiro Ito

For the backgrinding of semiconductor devices, a rotary grinding process is indispensable for achieving the required wafer thickness. The relative velocity between the grinding wheel and the wafer is maximum at the periphery of the wafer and minimum at the center of wafer. Generally, the grinding performances are discussed in terms of the ratio of the rotational speeds of the grinding wheel and the wafer. However, it is not possible to use this ratio to determine the grinding conditions for different wafer sizes grinding as this ratio does not show the difference in relative velocity. Therefore, a new relative velocity ratio was defined in this study. Then, the Si wafer grinding was performed to investigate the effect of the surface roughness and the power consumption of the grinding wheel spindle on the relative velocity ratio.


2018 ◽  
Vol 249 ◽  
pp. 03003 ◽  
Author(s):  
M A Aulestia Viera ◽  
F A Alexandre ◽  
P R Aguiar ◽  
R B Silva ◽  
E C Bianchi

The study and monitoring of the workpiece surface roughness is one of the most important parameters of the grinding process. This paper proposes a method for analysing the surface condition of ground ceramic components by means of the acoustic emission (AE) signal analysis along with frequency domain techniques. Tests were performed using a surface-grinding machine equipped with a resin-bond diamond grinding wheel, where signals were collected at 2 MHz. Alumina workpieces were machined under six different depth of cut values, covering slight, medium and severe grinding conditions. Frequency content was studied in order to select bands closely related to the process conditions. An analysis of the root mean square values (RMS) of the signals was performed, seeking for a correlation with the surface roughness. Digital filters were applied to the raw signals. The RMS values filtered for two frequency bands presented a better fitting to the linear regression, which is highly desirable for setting a threshold to detect the workpiece surface conditions and implementing into a monitoring system. Results showed that the amplitude of the signals presented different characteristics in the frequency domain according to the workpiece surface condition. It was also observed a higher spectral activity in the severe grinding conditions.


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