Papers by Keyword: Ultra-High Speed Grinding

Abstract: 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.

Abstract: According to broken edges and cracks emerging in traditionally machining cemented carbides (CP1) materials, this paper carried out some experimental researches on high and ultra-high grinding process for these materials, and considered the effect of process parameters on grinding forces, surface roughness, surface quality; discusses the calculation of the single grinding average normals force and relationship with maximum undeformed chip thickness and theoretical critical normal loads; probes the removal mechanisms of cemented carbide in high/ultra-high grinding process.

Abstract: The future development of the manufacturing is using VR technology to make the machining simulation before the actual machining process made. The machining simulation of Ultra High-speed Grinding Machine Tool is researched in this paper. Firstly, using UG/NX software and VRML, the geometric modeling of machine tool is modeled. Secondly, through using Java and Javascript language, the operation and display of machining process of ultra high-speed grinding are realized. The main technologies include NC codes compiling, collision detection and material removal. Thirdly, the example of machining simulation using virtual ultra high-speed grinding machine tool can be obtained in the paper. Compared to other CNC machining simulation methods, the method in the paper has reality display, rich features, a good man-machine interaction, etc., and it does not rely on expensive CAD/CAM software. The system files generated by the machining simulation have the small size and can be transferred on the network easily.

Abstract: In order to further improve machining quality of superhard materials, it was presented that adds a squeeze film damper on the wheel spindle of ultrahigh speed grinder as a assistant elastic sustain to attenuate the vibration of the wheel spindle. Work principle of squeeze film damper was analyzed; the squeeze film pressure distribution was researched through simulation and damper parameters effect on damping coefficient was studied. Base on the theory research the damper was designed and experiments was done. Experimental result shows the amplitude of the grinding wheel spindle can be reduced 20% and machining quality of superhard materials can be improved 10%～20%. Research works provides a new method for superhard materials machining.

Abstract: For improving grinding quality of ultrahigh speed grinding a new design method for ultrahigh speed grinding spindle is put forwarded based on squeeze film damping technology. Working principle of squeeze film damper of ultrahigh speed grinding spindle is study and differential equations of motion of the ultrahigh speed grinding wheel spindle with a squeeze film damper are set up according to d'Alembert principle. Effects of design parameters of the damper on the motion section of the spindle are studied by the way of simulation based on it. Research works show that the dynamic characteristic of ultrahigh speed grinding spindle can be improved well through adding a squeeze film damper. Research works provides a new technology for the design of the ultrahigh speed grinding spindle system.

Abstract: A remote fault diagnosis method for ultrahigh speeding grinding based on multi-agent is presented. The general faults of ultrahigh speed grinding are analyzed and diagnosis model based on multi-agent is established, the dialogue layer, problem decomposition layer, control layer and problem solving layer in the process of diagnosis are studied and the knowledge reasoning model of fault diagnosis is set up based case-based reasoning (CBR) combining rule-based reasoning (RBR). Based on theoretical research, a remote fault diagnosis system of ultrahigh speed grinding is developed. Results of the system running prove the theory is correctness and the technology is feasibility.

Abstract: Ultrahigh speed grinding is a kind of high efficient metal cutting method. In order to improve ability of ultrahigh greed grinding wheel spindle to resist vibration and grinding quality, an ultrahigh speed grinding spindle system with a squeeze film damper (SFD) was designed based on the theory of squeeze film damping technology. Pressure distribution and squeeze film stiffness characteristic of SFD was study by the method of simulation. Based on theory study an ultrahigh speed spindle system with a SFD was designed and experiments were done. The study results show that application of SFD technology can effectively restrain vibration which is caused by the imbalance quality when the grinding wheel spindle turning at ultrahigh speed. And the speed of the grinding spindle is higher and the effect of attenuation of SFD to grinding spindle is better. Research works provides a new technology for the design of the ultrahigh speed grinding spindle system.

Abstract: In order to improve the attenuation ability of grinding wheel spindle and manufacturing quality of workpiece, an ultrahigh speed grinding spindle system with a SFD was designed based on the theory of squeeze film damping, and a series of experiments were done. The study results show that the application of SFD technology can effectively restrain vibration which is caused by the imbalance quality when the grinding wheel spindle turning at ultrahigh speed. And the speed of the grinding spindle is higher and the effect of attenuation of SFD to grinding spindle is better. Research works provides a new technology for the design of the ultrahigh speed grinding spindle system.

Abstract: The balance precision of grinding wheel is a key technical parameter in ultra-high speed grinding process. The actual standard for the balance precision of rigid rotor is not fit for the thin ultra-high speed grinding system well. The unbalance factors affected on the ultra-high speed grinding wheel and its system were analyzed, and its effects on the machining quality in the process were also discussed. The theory and select principle of the balance precision for ultra-high speed grinding wheel system were studied. The test of dynamic performance was performed for the thin ultra-high speed CBN grinding wheel system whose structure was optimized. The groundwork to establish the standard of balance precision for thin ultra-high speed grinding system was offered.

Abstract: Remote control and fault diagnosis of ultrahigh speeding grinding is studied, which is based on the theory of rough set. Knowledge acquisition and reduction rule of fault diagnosis, realization method of remote control for ultrahigh speed grinding are studied, diagnosis model is established. Based on the theoretical research and ultrahigh speed grinder with a linear speed of 250 m/s, the remote control and fault diagnosis system of ultrahigh speed grinding is developed. Results of the system running show that the environment is improved, the mental pressure of workers is relieved and the efficiency is improved. At the same time, it proves that the ability to diagnosis and the accuracy of diagnosis for the ultrahigh speed grinding are improved and the time for diagnosis is shortened by applying rough set.