A Study on a High-Speed NC Gear Grinding Machine Using a Screw-Shaped CBN Wheel

1994 ◽  
Vol 116 (4) ◽  
pp. 1163-1168 ◽  
Author(s):  
T. Emura ◽  
L. Wang ◽  
A. Arakawa
Keyword(s):  
High Speed ◽  
Wave Length ◽  
Ccd Camera ◽  
Grinding Wheel ◽  
Direct Drive ◽  
Two Phase ◽  
Basic Study ◽  
Cbn Wheel ◽  
Gear Grinding ◽  
Grinding Machine

This paper describes a basic study for designing a high-speed NC gear grinding machine using a screw-shaped CBN wheel. Gear grinding machines using screw-shaped grinding wheels are quite prevalent. However, their productivity is not high, because the rotary speed of their spindles is very low. Therefore, the authors raised the maximum rotary speeds of the grinding spindle and the workspindle to 12,000 rpm and 3,000 rpm, respectively, in order to use a high-speed multithread CBN wheel. A magnetic scale whose wave length is long but pitch accuracy is high enough was used for detecting such a high-speed rotation. Since the wave length of the scale is long, a high-resolution interpolation using two-phase type PLL proposed by Emura was used. Both spindles are direct-drive type for removing backlash. When we grind gears, the initial setting between rotary angles of grinding wheel and work is required. The authors tried to automatically set the initial rotary angles by using a CCD camera.

A Study on a High-Speed NC Gear Grinding Machine Using Screw-Shaped CBN Wheel

1992 ◽  
Author(s):  
T. Emura ◽  
L. Wang ◽  
A. Arakawa
Keyword(s):  
High Speed ◽  
Reduction Gear ◽  
Grinding Wheel ◽  
Magnetic Head ◽  
Two Phase ◽  
Cbn Wheel ◽  
Gear Grinding ◽  
Phase Type ◽  
Rotary Speed ◽  
Grinding Machine

Abstract This paper describes a basic study for the development of a high-speed NC gear grinding machine using screw-shaped CBN wheel. Gear grinding machines using screw-shaped grinding wheel have already developed by Reishauer and others. However, their productivity is not high, because they use one thread type grinding wheel and the rotary speed of the workspindle is very low. The maximum rotary speed of the grinding spindle developed by the authors is 12,000 rpm and that of workspindle is 3,000 rpm. They are enough speed for gear grinding. The desired accuracy for an angle sensor of grinding spindle is more than 20 ″pp in the case of the multithread type grinding wheel. The ordinary shaft encoder cannot respond at such a high-speed. Therefore the authors used a magnetic scale of high-accuracy and an induction type magnetic head. After experiments, it became clear that two-phase type PLL proposed by T. Emura is useful for detecting low level signals obtained from the magnetic head. Since the maximum rotary speed of the workspindle is raised to 3,000 rpm, we cannot use any reduction gear. Thus a direct-drive method with an inertial damper was used. The workspindle is controlled by using the two-phase type PLL. When we grind gears, the initial setting between rotary angles of grinding wheel and work is required. The authors tried to automatically set the initial rotary angles by using a CCD camera and a microcomputer.

A PC-Based Synchronous Controller for NC Gear Grinding Machines Using Multithread CBN Wheel

1999 ◽  
Vol 123 (4) ◽  
pp. 590-597 ◽  
Author(s):  
T. Emura ◽  
L. Wang ◽  
M. Yamanaka ◽  
H. Nakamura ◽  
Y. Kato ◽  
...  
Keyword(s):  
Analog Circuits ◽  
High Speed ◽  
Production Costs ◽  
Two Phase ◽  
Pitch Accuracy ◽  
High Productivity ◽  
Cbn Wheel ◽  
Gear Grinding ◽  
Phase Type ◽  
Grinding Machines

This paper describes a synchronous controller for high-productivity NC gear grinding machines that use a screw-shaped CBN wheel of multithread. The authors developed a high-precision controller for productive-type NC gear grinding machines in 1995. Because it was based on analog circuits, it required very complex electrical circuits. In this paper, we propose a PC-based synchronous controller to decrease production costs and add useful functions to it. The most useful one added this time is a function to increase pitch accuracy of gear ground with the multithread CBN wheel. Next useful one is a function to attain high-accuracy initial meshing between gear and CBN wheel. Because grinding-spindle and work spindle rotate at a high-speed, two-phase type PLL is applied to the controller. Grinding experiments showed that the newly developed controller has excellent performance.

Ultra-High Speed Grinding Using a CBN Wheel for a Mirror-Like Surface Finish

2005 ◽  
Vol 291-292 ◽  
pp. 67-72 ◽  
Author(s):  
M. Ota ◽  
T. Nakayama ◽  
K. Takashima ◽  
H. Watanabe
Keyword(s):  
Surface Finish ◽  
High Speed ◽  
High Efficiency ◽  
Ground Surface ◽  
Machining Process ◽  
Grinding Wheel ◽  
Cbn Wheel ◽  
Ultra High Speed ◽  
High Speed Grinding ◽  
Grinding Conditions

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.

Research on Forms of Grinding Allowance Based on NC Form Grinding Cylinder Gear

2010 ◽  
Vol 42 ◽  
pp. 276-279
Author(s):  
Hong Xia He
Keyword(s):  
Numerical Control ◽  
Grinding Wheel ◽  
Axial Section ◽  
Gear Grinding ◽  
Form Grinding ◽  
Section Shape ◽  
Grinding Machine

The machining principle and characteristics of form grinding cylinder gear are introduced as well as the characteristics of form grinding machine in this paper. By analyzing and comparing three kinds of grinding allowance for cylinder gear grinding, a reasonable and effective axial section shape is determined in experience, which is a practical profile to shape the axial section of grinding wheel for numerical control grinding cylinder gears.

scholarly journals Study on Development of Servo-Spindle for NC Gear Grinding Machine Using Screw-Shaped CBN Wheel.

1995 ◽  
Vol 61 (587) ◽  
pp. 2988-2995
Author(s):  
Takashi Emura ◽  
Hisashi Nakamura ◽  
Masashi Yamanaka ◽  
Lei Wang ◽  
Yasushi Teshigawara
Keyword(s):  
Cbn Wheel ◽  
Gear Grinding ◽  
Grinding Machine

Analysis and Measurement of Effective Flow-Rate in Flood Grinding

2009 ◽  
Vol 626-627 ◽  
pp. 159-164 ◽  
Author(s):  
Chang He Li ◽  
Ya Li Hou ◽  
Yu Cheng Ding ◽  
Bing Heng Lu
Keyword(s):  
Boundary Layer ◽  
Flow Rate ◽  
High Speed ◽  
Good Description ◽  
Volumetric Flow Rate ◽  
Grinding Wheel ◽  
Work Surface ◽  
Grinding Fluid ◽  
Grinding Conditions ◽  
Grinding Machine

In the grinding process, grinding fluid is delivered for the purposes of chip flushing, cooling, lubrication and chemical protection of work surface. Due to high speed rotating grinding wheel, the boundary layer of air around the grinding wheel restricts most of the grinding fluid away from the grinding zone. Hence, conventional method of delivering grinding fluid that flood delivery is not believed to fully penetrate this boundary layer and, thus, the majority of the grinding fluid is deflected away from the grinding zone. The flood grinding typically delivers large volumes of grinding fluid was ineffective, especially under high speed grinding conditions. In the paper, a theoretical model is presented for flow of grinding fluid through the grinding zone. The model shows that the flow rate through the contact zone between the wheel and the work surface depends on wheel porosity and wheel speed as well as depends on nozzle volumetric flow rate and fluid jet velocity. Furthermore, the model was tested by a surface grinding machine in order to correlate between experiment and theory. Consequently, the effective flow-rate model was found to give a good description of the experimental results and the model can well forecast the effective flow-rate in flood delivery grinding.

Investigation of Surface Integrity on TC4-DT in High Speed Grinding with CBN Wheel

2014 ◽  
Vol 1027 ◽  
pp. 140-145
Author(s):  
Yao Guang Chen ◽  
Wen Zhuang Lu ◽  
Jun Xu ◽  
Yan Song Zhu ◽  
Dun Wen Zuo
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
High Speed ◽  
Linear Velocity ◽  
Grinding Wheel ◽  
Cbn Wheel ◽  
Increasing Trend ◽  
High Speed Grinding ◽  
Weak Influence ◽  
Quality Surface

A series of grinding experiments were carried out with CBN wheel to focus on the surface integrity of titanium alloy TC4-DT in high speed grinding . In order to get the proper process parameters to control the surface integrity of the TC4-DT, surface roughness, subsurface morphology and microhardness variations have been studied. In addition to the use of CBN wheel, scanning electron microscopy (SEM), 3-d contour instrument and microhardness tester was applied. The results show that the surface roughness is decreased obviously when grinding wheel linear velocity rises from 60m/s to 80m/s. While the grinding speed rises from 80m/s to 100m/s, the surface roughness value increases slightly. Moreover, the surface roughness value increases with the grinding depth and the increasing trend is obvious in the process of machining. The microstructure analysis shows that during high speed grinding with CBN wheels, good quality surface with 10μm grinding depth can be obtained. Table feed rate has weak influence on the grinding surface topography. The microhardness analysis indicates that surface microhardness increases sharply with the increasing of grinding wheel linear velocity in high speed grinding.

The In-Process Dressing Characteristics of Vitrified Bonded CBN Grinding Wheels

1993 ◽  
Vol 115 (1) ◽  
pp. 200-204 ◽  
Author(s):  
J. Williams ◽  
H. Yazdzik
Keyword(s):  
Cubic Boron Nitride ◽  
Matrix Material ◽  
Carbon Steels ◽  
Grinding Wheel ◽  
Scanning Electron Micrographs ◽  
Dimensional Tolerance ◽  
Wear Process ◽  
Cbn Wheel ◽  
The Matrix ◽  
Grinding Machine

When grinding carbon steels, creep-resistant materials, and other metals such a titanium, cubic boron nitride (CBN) has become recognized as the preferred choice over Al2O3 and SiC. The succes or failure of the grinding process with CBN lies in the mechanical dressing of the wheel because mechanical dressing is accompanied by very large stresses that distort the grinding wheel and deflect the grinding machine. One recent approach is to true the CBN wheel mechanically and then dress the wheel during the actual grinding manufacturing process. This work observes the dressing of vitrified bonded CBN during the actual like cycle in the production process of steel bearings. Scanning electron micrographs of CBN wheel surfaces are related to surface topography measurements of both wheel and bearing using a Tallysurf machine. In addition, the compositions of the wheel surfaces were checked using the SEM x-ray spectrography facilities. In-process dressing was determined to comprise three distinct stages: the primary or initial dressing, the secondary occurring during steady-state grinding, and finally the tertiary stage after which dimensional tolerance is lost. It was found that the life characteristics of the CBN wheel are quite different than current theories predict. Instead of the limitation of grinding being due to work material loading of the wheel and subsequent dulling of the grains, it was found that the CBN grains remain unchanged and a wear process occurs in the matrix material until the grains fall out and the wheels lose their dimensional tolerance.

New Development of Supersonic Surface Grinding Machine Tool with a Linear-Motor-Driven Table System

2016 ◽  
Vol 1136 ◽  
pp. 667-672
Author(s):  
Lu Yang ◽  
Yu Can Fu ◽  
Jiu Hua Xu ◽  
Yong Tao Liu
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
High Performance ◽  
Linear Motor ◽  
Grinding Wheel ◽  
Research Activities ◽  
High Speed Grinding ◽  
Grinding Mechanism ◽  
Speed Up ◽  
Grinding Machine

Ultra-high speed grinding (UHSG) is a significant and promising machining technology in grinding hard-to-cut materials. To find out the aerodynamics of the grinding wheel body when the airflow field has subsonic, transonic, and supersonic speed characteristics and clarify the corresponding influence on the grinding mechanism, the study is conducted to develop a supersonic grinding machine tool that is capable of being operated at extreme wheel speed up to 450 m/s and meanwhile accompanying with high grinding capability. In accordance with the main design objectives, a high performance grinding motorized spindle with maximum rotational speed 36000r/min and maximum power 28kW is developed. The linear motor feed driven system is also exploited to satisfy the requirement of maximum reciprocating speed up to 2m/s. Following plenty of specific design and performance analysis works, a prototype of supersonic grinding machine tool is finally developed. In the end, this paper also puts forward a number of further studies and prospective for the research activities on basis of the developed grinder.

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