Characteristics Of Machine Tool Research Articles

The Analysis on Dynamic Characteristics and the Structural Optimization of HRG Polishing Machine Tool

The dynamic characteristics of machine tool directly affect machining accuracy of the final parts. Taking the self-developed HRG ultra-precision polishing CNC machine tool as the research object, the simplified finite element model is established with the finite element analysis software to do the dynamic analysis and the natural frequency is detected as the index of the dynamic performances. Based on the comparative analysis of the natural frequency and vibration modes, the gantry and the supporting frame are recognized as structural weaknesses of the machine tool, and then the modal test is done to verify simulation results. Eventually the structural weaknesses are optimized effectively. The 1st order nature frequency of the optimized gantry and the optimized supporting frame is increased 75.5% and 80.8% respectively so that they have better dynamic performances, resulting in offering higher workpiece quality and process stability.

Static Analysis and Dynamic Analysis of CNC Machine Center Based on ANSYS

The static characteristic and dynamic characteristic of machine tool is one of the most important factors that affect the performance of machine tool, and it will affect the manufacturing final performance of the machine tool, and it is also an important index to evaluate the machine tool of high performances. Based on finite element structure analysis software ANSYS, the analyses of static and dynamic characteristics of VDL-1000 were conducted. The influencing factors to working accuracy were pointed out and a way was proposed to improve the structure of the machine center. All these can provide an important theoretical basis for the design and optimization of the machine center.

Research and Application of NC Machine Tool Energy Consumption Control Optimization

The numerical control machine tool, which is a typical energy-using product, because there are all sorts of energy loss and auxiliary functions, has low efficiency in machining process. Author makes a study of NC machine tool energy consumption controlling. With simens840Dsl numerical control system as an example, based on the analysis of CNC system control principle, according to processing characteristic of the part, the macro program is wrote to optimize dynamic characteristics of NC machine tool. According to the machine idle time in different work condition, three energy-saving control profiles are formulated, including machine standby, NC standby, auto shut off. By the formulation of the corresponding PLC control logic, low energy consumption of intelligent control of NC machine tool is realized. Integrate PAC3200/4200 multi-function meter in NC machine tools, quantitative measurement and analysis of energy consumption for numerical control system and ancillary equipment can be implemented, and machine tool real-time energy data can be obtained. This scheme has been successfully applied in long-men portable CNC machine tools, and obtained the ideal effect: to realize the optimize control of energy consumption, improve the performance of the machine tool, become more market competitiveness.

Computer Numerical Control Machine Tool and its Development Trend

CNC machine tools are the key equipment in the equipment manufacturing industry, which is related to the national economic construction and strategic position, and is an important symbol reflecting the national comprehensive level. This article analyzes the emergency and characteristics of CNC machine tools and its development trend such as high precision, high speed, high reliability, complex, intelligent, flexibility, integration and openness.

Track Smoothness of Moving Axis Considering Kinematical Characteristics of Machine Tool

In multi-axis NC (Numerical Control) machining for a complex part, high feed rate may bring shock to moving axes and influence the machining quality of the part. Firstly, velocity, acceleration and jerk kinematical characteristics are worked out according to the displacement curve of a moving axis. Secondly, the acceleration curve segments which need to be smoothed are found out according to the value of jerk, and these segments are smoothed with B-spline method. Then the smoothed velocity and displacement can be calculated through numerical integration method to get the new displacement curve of the moving axis. Finally, a test example is given to demonstrate the promising use of the proposed solution. The method presented by this paper can effectively decrease the acceleration shock of machine tool and improve the machining quality of part surface.

Dynamic Characteristics of Five-Axis CNC Machine Tools

According to the five-axis CNC machine tools, the main components are put to flexible and a rigid-flexible virtual prototype has been established. The influence on the machine tool stability is analyzed. The reliable theoretical basis has been provided for the structure optimization. Results are shown that simulation analysis based on a rigid-flexible coupling model is more accurate to show dynamics characteristics of machine tools.

The Research of the Dynamic Characteristics of Horizontal Jig Boring Machine

Modal analysis is one way of studying the dynamic characteristics of the mechanical. In order to study the dynamic characteristics of machine tool,numerical machine model is set up with finite element analysis software,of which validity is verified by experimental modal analysis.The experimental test also provide the boundary conditions, so as to further structure modification and dynamic characteristic design

Research on Experiment Modal Parameters Identification of Parallel Manipulator

The dynamic characteristics of parallel 3-TPT machine tool are researched by experiment in this paper. Firstly, the parameters of dynamic characteristic were identified by theoretical analysis. Then vibration model of Parallel Manipulator was built and formed vibration system for experiment analysis. Then, the modal experiment method and steps were introduced, and the experiment parameters also were identified according to the experiment results. The result dates showed that the result dates are validated. So the method is feasible by experimental verification, which provides reference for dynamic optimal design

Experimental Research on Parameters Identification of Dynamic Characteristic for Parallel Machine Tool

The dynamic characteristics of parallel 3-TPT machine tool are researched by experiment in this paper. Firstly, modal analysis principle of machine tool was analyzed in theory, and the parameters of dynamic characteristic were identified by theoretical analysis. Then vibration model of parallel machine tool was built and formed vibration system of rigid and flexible coupling for analysis. Then, the modal experiment method and steps were introduced, and the experiment parameters also were identified according to the experiment results. The result dates are showed that the result dates are validated. So the experiment method is feasible by experimental verification, which provides reference for dynamic optimal design.

The virtual design of machining centers for HSM: Towards new integrated tools

The virtual design of machining centers is a modern and well-known computer aided technique. Several modeling and simulation architectures, based on the lumped mass approach and on finite element method, are now well established and widely exploited worldwide. These solutions rapidly allow the basic setup of the kinematics of the feed drives and make possible a dynamic optimized dimensioning of all the main subsystems and structures of the machining center. This paper deals with research efforts aimed at developing an innovative and open design platform which allows the integration, in a user friendly framework, of the main procedures cited above with other design tools and facilities. An operator interface procedure and a package of input–output graphic routines, managed through a multilevel data base, are now active in this framework and interact with lumped mass and finite elements modules. According to these considerations the proposed tool allows to quickly and easily analyze alternative design solutions and makes possible to optimize the dynamic performances of the machine tool, helping the designer in the definition of the optimum machine tool characteristics before the manufacturing of the physical prototype. In order to demonstrate the potential of the proposed platform an example concerning the mass optimization of the Y axis of a gantry machining center is presented.

Optimum Design of Machine Tool Structures Based on BP Neural Network and Genetic Algorithm

In order to estimate and optimize the static and dynamic characteristics of machine tool, the full parameterized FEM model of it is established and studied in the paper. After the FEM analysis of bed, this paper takes a machine bed as example, presents a method of combination of BP Neural-Network(NN) and Genetic-Algorithm(GA) to optimize dynamic characteristics and realizes the structural optimization of the bed. It proved that this method takes less time, and more precision compared to traditional method.

Dynamic Characteristics of Ultra-Precision Machine Tools (Evaluation for Stiffness of Guideways by Impact Test)

This study discuss the dynamic stiffness of guideways of a ultra-precision machine tools. V-V roller guideways have been employed in ultra-precision machine tools, as they can provide very smooth motion and good straightness. Recently, general linear ball guideways are also employed in ultra-precision machine tools. In the design of the machines, it is necessary to obtain the stiffness of these guideways. Therefore an identification method of the guideway stiffness is verified in this paper. In this method, the guideway stiffness is identified from the natural frequency of the moving body. First, the impact test is carried out for an ultra-precision machine tool to obtain the vibration mode of its moving body. Next, a simple vibration model is developed based on the obtained vibration mode to identify the equivalent stiffness of the guideways. Then, the static stiffness of the guideways is measured for the verification of the identified equivalent stiffness. For further verification, natural frequencies of the moving body are calculated by FEM with the identified equivalent stiffness and compared with the measured natural frequencies. The identified equivalent stiffness agreed well with the measured static stiffness. Furthermore, the natural frequencies were calculated almost correctly with the identified equivalent stiffness.

Content Architecture and Future Trends of Energy Efficiency Research on Machining Systems

Machining systems are in enormous quantity and the potentiality for energy-saving and emission-reduction to environment is great, which also involves lots of scientific problems, so that a number of studies on energy efficiency of machining systems are being done on the international scene in recent years. The extended connotation of energy efficiency of machining systems is summarized firstly. The state of the art of energy efficiency research on machining systems is investigated through the lenses of general overview and category of research objects. Based on the review, a content architecture framework of energy efficiency research on machining system is advanced, which includes three objects(machine tools, workpieces and system), five basic technology issues(the energy efficiency of energy consumption links and energy consumption components, the modeling of energy consumption and energy efficiency, the energy efficiency characteristics of machine tools and workpieces, the evaluation of energy efficiency, and the energy efficiency monitoring and management of machining systems), two kinds of functional techniques(high-energy-efficiency operation of machining system and high-energy-efficiency design of machine tools) and two objectives(improve the energy efficiency on machining system and develop high-energy-efficiency machine tool). Finally, the future trends of the energy efficiency research for machining system are concluded, which can be detailed as integrated modeling of energy efficiency,platform construction of energy efficiency assessment, energy consumption quota of machining task, energy efficiency optimization during the operation of machining systems and energy efficiency integration during the design of machine tools.

Identification of Accuracy Characteristics Importance of Machine Tool for Parts Machinability Evaluation

Motivated by the coupling relationship between the machine tools accuracy variation process and parts cutting process,an identification method is developed,which addresses key accuracy characteristics of machine tools for parts machinability evaluation.Hidden Markov model(HMM) is constructed via regarding the accuracy variation process and cutting process as a coupling system.The coupling system state transition matrix consists of the state transition matrix for each cutting characteristics and their importance vector.The state of each cutting characteristics is given capitalizing on the relative error between the measured data and fitted value calculated from improved support vector machine(SVM).Additionally,parts machinability evaluation model is formulated,proposed to get the optimal cutting characteristic state for coupling system.Cutting characteristic importance vector is determined by the parameters estimation of HMM,taking advantage of improved quantum genetic algorithm(QGA).Meanwhile,accuracy characteristics of machine tools are identified through quality function deployment(QFD),based on the fuzzy associated matrix of coupling system and cutting characteristics importance vector.An example is given to verify the feasible and effectiveness of the method.

Theoretical Analysis and Experimental Study on Static Characteristics of the Cylindrical-spherical Joint Surfaces of Linear Ball Guide on Machine Tool

Machine tool characteristics mainly depend on the systematic stiffness properties composed of the constructional component stiffness and the joint stiffness. The joint stiffness of linear ball guide is the primary constituent portion of the system stiffness. The linear ball guide pair is composed of some slides and rails, and the joint between one slide and rail is called the joint cell of linear ball guide. A joint cell of the linear ball guide is composed of many joint surfaces, namely multi-column, multiple cylindrical-spherical joint surfaces. An analytical method is introduced for the static characteristics of the cylindrical-spherical joint surfaces based on the fundamental parameters of the joint, and which is validated by the comparison between a case study and experimental results. Therefore, the method can be used in the design and analysis of cylindrical-spherical joint surface.

Accuracy analysis of machine tools using Elastically Linked Systems

The paper introduces the concept of Elastically Linked Systems (ELS) to directly relate the machine tool positional and static accuracy to the machined part's geometric errors and form deviation. Practical implementation of the ELS concept resulted in a novel test equipment, Loaded Double Ball Bar (LDBB) which is a precision mechatronic device with variable load. The test method based on the device is able to reveal machine tool characteristics not obtainable with existing methods as for instance the variation of stiffness in the entire working space. The LDBB is used to experimentally evaluate the stiffness and the corresponding accuracy of five machine tools.

Research of Moving Table with Aluminum Foam-Filled Structure

In order to explore the changes of static and dynamic characteristics of machine tool components in which aluminum foam material was used, the characteristics of the prototype table and filled structure one was analyzed by ANSYS.It is shown that static and dynamic characteristics of machine tool can be improved by using aluminum foam-filled structure.Compared with cast iron material,the inherent frequency of table with aluminum foam-filled structure significantly improved,resonant response amplitude has decreased.It was accord with the requirements in the lightweight and high dynamic performance under the condition of ultra-high speed processing.

Toolpath Generation Method Based on Control Characteristics of Machine Tool for High-Speed and High-Accuracy Machining

Drive control of NC machine tools is based on linear interpolation. When curved surfaces are machined using linear interpolation, problems arise with the feedrate not reaching the command feedrate, machining accuracy and surface quality decreasing, etc. In order to solve such problems, a method for generating a toolpath based on the control characteristics of a machine tool is proposed. The effectiveness of the proposed method is confirmed through simulations and experiments. It is found that the proposed method can reduce the cutting time to approximately 50% of the time required when conventional CAM systems are used. The proposed method also improves surface quality.

Modal Analysis and Optimization of Spindle Box of Turn-Milling Center Based on Finite Element Method

The dynamic characteristics of machine tool may directly affect its machining capability, which is analyzed to improve the machining precision and efficiency. In this paper, the 3D finite element model of main components turn-milling center is established by using ANSYS software, and then spindle box of turn-milling center is analyzed and optimized; the natural frequencies and vibration models are obtained after analysis, which guarantee the design requirement of the machining center. Therefore it is significant to improve the design quality of machining center by using FEA software in the design process.

An Experimental Study on Working State Recognition of Machine Tools

In order to obtain the real-time working state of machine tools, this experiment extracted the characteristics of machine tools using joint time-frequency analysis and wavelet packet analysis for the total current signal collected, to distinguish which machine is running. First, use joint time-frequency analysis on signal of a single machine to get different characteristics. And find some frequency points with amplitude changing significantly, preparing for the subsequent experiment. Then use wavelet packet analysis on the total signal of more than one machine, finding more obvious characteristics of the different machines with different speeds. Thus it is easy to identify which machine is working. By this experiment, we can save labor, improve efficiency and integrate information in system conveniently.