Machine Bed Support with Sliding Surface for Improving the Motion Accuracy

2016 ◽  
Vol 10 (3) ◽  
pp. 447-454 ◽  
Author(s):  
Yusaku Shirahama ◽  
◽  
Ryuta Sato ◽  
Yusuke Takasuka ◽  
Hidenori Nakatsuji ◽  
...  

The purpose of this study is to develop a new machine bed support mechanism for reducing the vibration generated during the high-speed tracking motion of numerical control machine tools. In order to achieve this, the frequency response and motion trajectory of a machine tool with the proposed machine bed, which has a sliding surface, are measured and compared with that of the conventional support. Based on the modal analysis of the machine tool structure, a mathematical model representing the influence of the machine bed characteristics on the vibration is also developed. The model consists of a bed, saddle, table, column, and spindle head. Every component has three degrees of freedom for each of the translational and rotational axes. In order to evaluate the characteristics of the machine bed, the mathematical model determines the stiffness and damping along the X-, Y-, and Z-axis between the bed and the ground. The frequency response curves simulated by using the mathematical model are compared with that of the measured ones. From the results of the experiments and simulations, it is confirmed that the vibration generated during high-speed tracking motions can be reduced by using the proposed machine bed with a sliding surface.

2016 ◽  
Vol 693 ◽  
pp. 1611-1617
Author(s):  
Bai Sheng Ye ◽  
Li Qiang Zhang

Aiming at the corner connection speed of continuous small blocks caused by their angle influences, the speed of transition is low and easy to cause vibration of machine tool. Research on the mathematical model of constant-speed linking of multiple periods is established by using the arc to smooth continuous small blocks, combined with the transition’s geometrical constraint, motion constraint, parameter calculation, the theory is to realize the method of high-speed interpolation of constant-speed linking of multiple periods. The result reveals that the effectiveness and practicability of the proposed method.


2010 ◽  
Vol 156-157 ◽  
pp. 1297-1300
Author(s):  
Xue Bin Liu ◽  
Wei Zhao ◽  
Su Chang Ma ◽  
Chong Ning Li

The numerical controlling simulation of process indicates a mapping of NC machine tool in the virtual environment, and it includes the technique of manufacture, the theories of NC machine tool, CAD, CAM, and the technique of modeling and simulating. The people can apperceive the virtual environment of 3D simulated model developed by computers, carry the NC process of parts in virtual condition before the true doing when we design or alter a project, inspect the exactitude and justification of NC program, evaluate and optimize the project of process. Thereby the intention, abridging the time of developing products, depressing the cost of manufacture, advancing the quality of products and the efficiency of Production, can be finally achieved. With the rapid development of NC technique and computer graphical technology and the extensive application of computer, NC simulation technology provide an effective tool in order to validate the NC machining program and forecast the machine process. The main purpose of this dissertation is to derive the mathematical model and to simulate the lathe tool cutter. In order to enhance the operating efficiency and the demonstration quality of the numerical control lathe simulation software, the analysis has compared a kind of shape about lathe tool cutter-- PARALLELOGRAM, has established the cutter forms, thus inferred the mathematical model of the numerical control lathe simulation on the lathe tool cutter. The cutter is display in the DELPHI software development platform based on the environments of GLSence using this derived mathematical model.


2010 ◽  
Vol 154-155 ◽  
pp. 1064-1067
Author(s):  
Li Bing Zhang ◽  
Ting Wu

A numerical control (NC) code program is usually generated by a complex CAD/CAM system, which does not include the value of the tool radius compensation. To increase the material machining accuracy within the permissible machining accuracy range, this paper presented the approach of the tool radius compensation for high-speed and high-accuracy material machining. The principle and method of the tool radius compensation were put forward and analyzed, the mathematical model of the tool radius compensation was deduced according to the correlative factors, and the algorithm of the tool radius compensation was constructed for high-speed and high-accuracy. The simulative and experimental results verified the feasibility and validity of the proposed approach.


2014 ◽  
Vol 556-562 ◽  
pp. 1354-1357
Author(s):  
Li Gong Cui ◽  
Gui Qiang Liang ◽  
Fang Shao

This paper presents a mathematical method to analyze the influence of each machine tool part deformation on the machining accuracy. Taking a 3-axis machine tool as an example, this paper divides the machine tool into the cutting tool sub-system and workpiece sub-system. Taking the deformation of lower surface of the machine bed as the research target, the mathematical model of the deformation on the displacement of the cutting point was established. In order to distribute the stiffness of each part, the contribution degree of each part on the machining accuracy was analyzed. Using this mathematical model, the stiffness of each part can be distributed at the design stage of the machine tool, and the machining accuracy of the machine tool can be improved economically.


2010 ◽  
Vol 426-427 ◽  
pp. 299-302
Author(s):  
Fa Ye Zang

Based on deeply analyzing the working principles and energy-saving theory of loader secondary regulating transmission system, regenerating the transmission system’s inertial energy by controlling constant torque was put forward. Considering large changes of the parameters of the transmission system and its non-linearity, a fuzzy control was adopted to control the transmission system, and the mathematical model of the system was established, then the simulations of the performance of the transmission system has been conducted. The conclusion was made that the inertial energy can be reclaimed and reused in the system by the application of the secondary regulation technology, and braking by controlling constant torque is stable, it can ensure the security of braking at high speed and also permits changing the efficiency of recovery by changing the braking torque. The system’s power has been reduced and energy saving has been achieved.


2020 ◽  
pp. 29-33
Author(s):  
S. V. Kondakov ◽  
O.O. Pavlovskaya ◽  
I.D. Ivanov ◽  
A.R. Ishbulatov

A method for controlling the curvilinear movement of a high-speed tracked vehicle in a skid without loss of stability is proposed. The mathematical model of the vehicle is refined. With the help of simulation modeling, a control algorithm is worked out when driving in a skid. The effectiveness of vehicle steering at high speed outside the skid is shown. Keywords: controlled skid, dynamic stability, steering pole displacement, hydrostatic transmission, automatic system, fuel supply. [email protected]


2021 ◽  
pp. 95-102
Author(s):  
K. I Barinova ◽  
A. V Dolgopolov ◽  
O. A Orlova ◽  
M. A Pronin

Flutter numerical analysis of a dynamically scaled model (DSM) of a high aspect ratio wing was performed using experimentally obtained generalized parameters of eigen modes of vibrations. The DSM is made of polymer composite materials and is designed for aeroelastic studies in a high-speed wind tunnel. As a result of the analysis, safe operation conditions (flutter limits) of the DSM were determined. The input data to develop the flutter mathematical model are DSM modal test results, i.e. eigen frequencies, mode shapes, modal damping coefficients, and generalized masses obtained from the experiment. The known methods to determine generalized masses have experimental errors. In this work some of the most practical methods to get generalized masses are used: mechanical loading, quadrature component addition and the complex power method. Errors of the above methods were analyzed, and the most reliable methods were selected for flutter analysis. Comparison was made between the flutter analysis using generalized parameters and a pure theoretical one based on developing the mathematical model from the DSM design specifications. According to the design specifications, the mathematical model utilizes the beam-like schematization of the wing. The analysis was performed for Mach numbers from 0.2 to 0.8 and relative air densities of 0.5, 1, 1.5. Comparison of the two methods showed the difference in critical flutter dynamic pressure no more than 6%, which indicates good prospects of the flutter analysis based on generalized parameters of eigen modes.


Author(s):  
Yuqing Zhou ◽  
Xuesong Mei ◽  
Gedong Jiang ◽  
Nuogang Sun ◽  
Bai Shao

Simultaneous rotary-translational (R-T) axis motion error has significant influence on multi-axis machine tool precision. To improve multi-axis machine tool precision, axis motion error measurement and trace method are investigated in this study. A sensorless R-T axis motion error measurement and trace technology based on virtual bar is proposed. Firstly, the fundamental sensorless test principle is discussed. Then, the virtual-bar-based test path of a circular test though a rotary axis and two translational axes motion is scheduled. The mathematical model of motion error is established. Furthermore, to identify the error source, spatial error charts and some advanced signal processing and feature extraction technologies, such as wavelet transform and frequency analysis, are used. The analysis of experimental results shows that it is practical and efficient to use the virtual bar and the sensorless information to estimate motion error.


2018 ◽  
Vol 152 ◽  
pp. 02001
Author(s):  
Ali Mohamed Rathiu ◽  
Mohammad Hosseini Fouladi ◽  
Satesh Narayana Namasivayam ◽  
Hasina Mamtaz

Vibration of high-speed lines leads to annoyance of public and lowering real estate values near the railway lines. This hinders the development of railway infrastructures in urbanised areas. This paper investigates the vibration response of an isolated rail embankment system and modifies the component to better attenuate ground vibration. Mainly velocity response is used to compare the responses and the applied force is of 20 kN at excitation frequencies of 5.6 Hz and 8.3 Hz. Focus was made on ground-borne vibration and between the frequency range of 0 and 250 Hz. 3D Numerical model was made using SolidWork software and frequency response was produced using Harmonic Analysis module from ANSYS Workbench software. For analytical modelling MATLAB was used along with Simulink to verify the mathematical model. This paper also compares the vibration velocity decibels (VdB) of analytical two-degree of freedom model mathematical model with literature data. Harmonic excitation is used on the track to simulate the moving load of train. The results showed that modified analytical model gives the velocity response of 75 VdB at the maximum peak. Changes brought to the mass and spacing of the sleeper and to the thickness and the corresponding stiffness for the ballast does not result in significant vibration response. Limitations of two-degree analytical model is suspected to be the cause of this inactivity. But resonance vibration can be reduced with the aid of damping coefficient of rail pad. Statistical analysis methods t-test and ANOVA single factor test was used verify the values with 95% confidence.


1965 ◽  
Vol 5 (41) ◽  
pp. 567-587 ◽  
Author(s):  
J. F. Nye

AbstractThe theory developed in previous papers to represent the response of a glacier to changes in the rate of accumulation and ablation has been used for a number of applications. A method of integrating the differential equations for a fixed frequency was programmed for a high-speed digital computer. This provides a better way of finding the frequency response than the earlier method which used series approximations or high and low frequencies. Results are given for (a) an artificial glacier showing varying amounts of diffusion of the kinematic waves, (b) South Cascade Glacier, Washington, U.S.A., as a check on previous results, and (c) Storglaciären, Kebrekaise, Sweden. The response curves of Storglaciären are very similar in shape In those of South Cascade Glacier but, since. Storglaciären moves more slowly, the curves are shifted in frequency (by a factor of two). The phase of the response at the terminus of Storglaciären plotted against frequency shows a double peak.Certain mathematical results for the artificial case of no diffusion are given in an Appendix.A computer programme was also written for calculatingλandμcoefficients and applied to South Cascade Glacier and Storglaciären.


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