Papers by Keyword: Grinding Machine

Abstract: The vibration of grinding wheel spindle will significantly reduce the machining quality and machining accuracy of precision grinding. In order to suppress the grinding wheel rotor vibration effectively, the Spray-Typed online dynamic balance system for specific grinding wheel spindle was designed composed of terminal balance, hydraulic system and control system. To achieve the amount of spindle unbalance accurate extraction and liquid volume control, using hydraulic system to achieve the balance of the terminal of the liquid loading and using high-performance DSP chip as a control method. A segmented spindle online dynamic balance method , combining the advantages of influence coefficient method and coordinate rotation optimization method was proposed. The method can fast approaching the goal of balancing and meet the local precise adjustment of the balance weight. At last, the online dynamic balance experiment of grinding wheel spindle is carried out in the industrial field, the grinding spindle vibration displacement amplitude decreased from 17.8 to 7.7 before and after balance, fall by as much as 55%, which verifies the validity and feasibility of the system.

Abstract: Manufacture of ultra-precision micro-structured freeform surface relies on the high precision of machine tools. Precision, stability and repeatability of the Z-axis are the key factors of the high precision machine tools. The key component of the Z-axis is the ram, and its stiffness and stability have a crucial influence on the final precision. This paper demonstrated the structure optimization of the ram using finite element method based on ANSYS and the results were achieved to illustrate how the optimization variables affect the stiffness and deformation of the ram. Finally, the local three optimal design points were displayed and one of the most appropriate candidate points was chosen as the new design.

Abstract: A finite element model of an ultra-precision grinding machine that can have high precision and high stiffness is constructed and structural analysis is done with equivalent stiffnesses of linear motion guides by after structural design and the deformation of the grinding machine is obtained. In order to reduce the deformation of the grinding machine that causes bad influence, structural complement is conducted by adding ribs at the lower part of the column. Also, the straightness of the grinding machine is improved by lifting that the base side of the column.

Abstract: As a new process, the abrasive belt grinding plays an increasingly important role in the field of machining. It meets a variety of processing requirements. The concept of abrasive belt grinding and its working principle were introduced, and a new type of abrasive belt grinding equipment for removing the rust on steel wire surface was designed. Some key experiments for testing grinding force，the metal removal rate，belt wear rate、grinding ratio，grinding depth and wire speed were studied. The research work provides rational parameters for the pretreatment of rust removal in metal wire drawing processing.

Abstract: As a harmful impurity, Pyrophyllite must be remove in synthetic diamond purification process. It commonly use chemical method. A trial research is made on the removing of pyrophyllite impurity in synthetic diamond by physical method. As a result, after synthetic diamond materials containing pyrophyllite are selectively interground in the ball grinding machine, the pyrophyllite is effectively broken and removed from the coarse – medium grade diamond only by physical method, but diamond quality is not affected.

Abstract: A novel diaphragm-control restrictor (DCR) is proposed for improving the performance of the hydrostatic-bearing spindle used in machine tools. The unique function of the proposed DCR is the wide adjustability of its restrictor characteristic. A two-step restriction system is adopted for the DCR; a spool restrictor is used as the first step restrictor. By changing the restrictor resistance of the spool restrictor, the effect of the active control in the DCR, the second step restrictor, can be altered. The proposed DCR is incorporated into a hydrostatic bearing supporting a precision spindle, and the performance of the bearing is analyzed. Numerical and experimental analyses show that the stiffness of the hydrostatic bearing with the proposed DCR can be five times as large as a conventional hydrostatic bearing of the same dimensions. Analysis of the dynamic compliance shows that the effect of the active control can be observed up to 20Hz. These results show that the proposed DCR is useful for improving the performance of the hydrostatic-bearing spindle in precision applications.

Abstract: Blade is the key part of aeroengine. The main method for grinding blade is manual operation, which is inefficient. A new machine for grinding both sides of blade synchronically is proposed in this paper to improve the efficiency and machining accuracy. The modal analysis for the machine is demonstrated using ANSYS and the modal testing experiments verify the theoretical analysis.

Abstract: Permanent magnet linear synchronous motors (PMLSM) offer several advantages over their rotary counterparts in many precision manufacturing applications requiring linear motion, which can achieve a much higher speed and a higher position accuracy. However, linear motors are more sensitive to disturbance and parameter variations. Furthermore, the linear motor systems are subject to significant nonlinear effects due to friction and force ripple. A sliding mode controller with an adaptive disturbance observer is processed to achieve high accuracy in the presence of external disturbance and parameter uncertainty. The position control for the gringding machine of a PMLSM feed drive using the proposed control strategies is illustrated. Simulation results show that the proposed controllers provide high-performance dynamic characteristics and are robust with regard to external load disturbance.

Abstract: The value of grinding angle of grinding machine directly affects working efficiency and processing precision of gear grinding machines. A mathematical model of Generating Motion is established by analyzing and studying working principle and machining processes of the grinding machine. Equations of Generating Motion had been determined when the grinding machine was working. Then the relationship between grinding angle and Generating Motion was gotten and the optimal value of the grinding angle was finally obtained.

Abstract: The dynamic model of machine tool structure is the basic of its dynamic analysis and dynamic optimization. The determination of joint interface stiffness and damping of grinding machine structures is one of key problems to dynamic analysis of machine tools. A method to identify interface dynamic parameters of grinding machine structures using measured transfer function data and optimization technique is presented in this paper. Finally, do the whole machine modal analysis with method and finite element method, contrast the experimental and theoretical results, proved this finite element model can stimulate the dynamic performance of the whole machine effectively, it is of practical value of engineering application.