共查询到20条相似文献,搜索用时 15 毫秒
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Hyeong Jun Kim Sung Soo Ryu Seongwon Kim Hyeong Tae Kim 《International Journal of Precision Engineering and Manufacturing》2009,10(3):13-17
In this study, three ZnO-B2O3-SiO2 frit compositions with low softening point were investigated in order to lower the firing
temperature of cBN-based vitrified bonded wheel. It was tried to develop a new composition of vitrified bond with lower firing
temperature and compatible mechanical properties compared with conventional bond by evaluating the mechanical properties of
each frit composition. Suggested bonds have softening points of 500°C to 520°C and bending strengths of 60 to 90% compared
to the conventional bond. The maintenance of bending strength of bond composition even with less network former is attributed
to the growth of Gahnite, which has submicron size and relatively large thermal expansion coefficient. On the other side,
Willemite (ZnO·SiO2) with large crystalline size and low thermal expansion resulted in the deterioration of bending strength.
The Rockwell hardness used as common measure of bonding of grinding wheel showed no statistically significant difference among
frit compositions in the results. 相似文献
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从分析现有大型砂轮机构装卸实际情况入手,简单介绍了电主轴的结构,重点论述了电主轴砂轮机构自动更换砂轮的实施过程. 相似文献
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This paper combined experimentally-measured grinding wheel topography data taken around the entire circumference of the grinding wheel with a kinematic simulation of the grinding process. Several new methods were developed in order to create the resulting high-fidelity and computationally-efficient simulation. First a novel peak-removal technique was developed and applied to effectively remove erroneous peaks in the raw wheel topography data. Next a method was found to determine only the active cutting points on the wheel model by considering the kinematics of the grinding process. This new approach was able to reduce the simulation time from over twelve hours to about four seconds without losing any information about the cutting edge–workpiece interaction. The resulting predicted workpiece surface was then experimentally validated by carrying out a grinding experiment using the same grinding wheel used to develop the grinding wheel computer model and then measuring the resulting workpiece surface profile. Good agreement between simulated and experimental workpiece profiles was observed. Finally, the validated simulator was used to develop a kinematically-exact method to calculate the maximum uncut chip thickness and the simulation results were investigated for different depths of cut, wheel speeds and workpiece feeds. 相似文献
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Young-Sam Ham Dong-Hyong Lee Seok-Jin Kwon Won-Hee You Taek-Yul Oh 《International Journal of Precision Engineering and Manufacturing》2009,10(1):35-39
Oscillatory wheel load fluctuation of considerable amplitude is always observed in railway cars traveling at high speed. This
paper describes a continuous method for measuring the derailment coefficient and the forces between the wheel and rail. The
acceleration measured on the axle box indicates that the frequency of this fluctuation can be as high as 70 Hz. Continuous
measurement of wheel load using conventional methods is not possible due to this high frequency phenomenon. We have developed
a new method for continuous measurement of these forces and the derailment coefficient using two pairs of strain gauge bridges
with output phases shifted by 90°, and summing their outputs with a weighting function. This method works for measuring the
forces between wheel and rail at high frequencies. 相似文献
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Identifying the situation of grinding wheel wear and loading is a very important issue for high efficiency grinding operations.
This paper presents a new method that detects and identifies the chip loading and cutting edge wear of a grinding wheel using
the image processing toolbox of MATLAB. The different optical characters of the metal chips and the abrasive grains are analysed.
The Sobel operator is adopted to make edge detection. A sensitivity threshold based on the global condition is used to decrease
the noise. Image dilation and erosion processes are used to ensure the edge of each loaded chip is covered by a continuous
section. The ratios of chips are calculated and displayed to monitor the wheel surface working status. 相似文献
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Z. Feng X. Chen 《The International Journal of Advanced Manufacturing Technology》2007,32(5-6):452-458
Identifying the situation of grinding wheel wear and loading is a very important issue for high-efficiency grinding operations.
This paper presents a new method that detects and identifies the chip loading and cutting edge wear of a grinding wheel using
the image processing toolbox of the MATLAB package. The different optical characters of the metal chips and the abrasive grains
are analysed. The Sobel operator is adopted to make the edge detections. A sensitivity threshold based on the global condition
is used to lower the noise. Image dilation and erosion processes are used to ensure that the edge of each loaded chip is covered
by a continuous section. The ratios of chips are calculated and displayed to monitor the wheel surface working status. 相似文献
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Yon-Kyu Park Min-Seok Kim Jong-Ho Kim Dae-Im Kang Hou-Keun Song 《Journal of Mechanical Science and Technology》2006,20(7):961-971
A deadweight force standard machine is a mechanical structure that generates force by subjecting deadweights to the local
gravitational field. The Korea Research Institute of Standards and Science (KRISS) developed and installed a 100 kN deadweight
force standard machine for national force standards. It can generate forces from 2 kN to 110 kN in increments of 1 kN. The
uncertainty of the force machine was estimated and declared as 2 × 10−5. This 100 kN deadweight force machine was compared with the 500 kN deadweight force standard machine at KRISS and the 20
kN and 50 kN deadweight force standard machines at the National Metrology Institute of Japan (NMIJ). The measurement results
showed good agreement between the deadweight force machines, and the accuracy level of the 100 kN deadweight force machine
was verified. 相似文献
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通过用陶瓷结合剂CBN砂轮对45淬硬钢工件进行磨削试验,深入分析了机床特性对CBN砂轮磨削比的影响,获得了能够进行CBN砂轮高速高效磨削的机床特征参数。 相似文献
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《Measurement》2016
This paper describes the design and validation of an upgraded grinding wheel scanner system that controls the position of a Nanovea CHR-150 Axial Chromatism sensor along the x- and y-directions of the wheel surface to measure and characterize wheel surface topography. The scanner features a novel homing system that enables the wheel to be removed from the scanner, used on a grinding machine and then re-mounted and re-homed so that the same location on the wheel surface can be repeatedly measured and monitored. The average standard deviation for homing was 27.6 μm and 19.3 μm in the x- and y-directions, respectively, which is more than adequate for typical area scans of 25 mm2. After homing, the scanner was able to repeatedly measure features that were similar in size to an abrasive grain (∼200 μm diameter) with an average error of 9.3 μm and 5.9 μm in the x- and y-directions, respectively. The resulting topography measurements were compared with Scanning Electron Microscope images to demonstrate the accuracy of the scanner. A custom particle filter was developed to process the resulting data and a novel analysis technique involving the rate of change of measured area was proposed as a method for establishing the reference wheel surface from which desired wheel topography results can be reported such as the number of cutting edges, cutting edge width and cutting edge area as a function of radial depth. 相似文献