Study on the Thermal Characteristics Simulation and Error Compensation of Long Rail of Heavy Numerically-Controlled Machine Tool

2014 ◽  
Vol 577 ◽  
pp. 187-191
Author(s):  
Ming Yue Xiao ◽  
Zhong Ping Hua ◽  
Shui Sheng Cheng
Keyword(s):  
Finite Element ◽  
Machine Tool ◽  
Error Compensation ◽  
Thermal Deformation ◽  
Thermal Characteristics ◽  
Machining Accuracy ◽  
Guide Rail ◽  
Ansys Software ◽  
Working Process ◽  
Main Factors

In the working process of numerically-controlled machine tool, the generation of heat by friction between the guide rail and the workbench will cause the thermal deformation under the high temperature, which impacts on the machining accuracy of machine tool. Through the finite element modeling for the guide rail of machine tool by the ANSYS software, the thermal characteristics is simulated in the process of guide rail, then the main factors of thermal deformation is analyzed, finally the corresponding measures focusing on the error compensation is proposed.

Thermal Characteristics Finite Element Analysis and Temperature Rise Experiment for High Speed Motorized Spindle

2011 ◽  
Vol 52-54 ◽  
pp. 1206-1211 ◽  
Author(s):  
Huai Xing Wen ◽  
Mei Yan Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Machine Tool ◽  
Temperature Rise ◽  
High Speed ◽  
Thermal Characteristics ◽  
Analysis Model ◽  
Ansys Software ◽  
Motorized Spindle ◽  
Element Analysis

The thermal characteristics of the motorized spindle determines maching qualities and cutting capabilities, and is one of the important factors influencing the precision of the high speed NC machine tool. To improve the performance of the high speed machine tool, it is important to study the thermal characteristics of the motorized spindle. It had been studied in two ways: one is finite element analysis by Ansys software, in which the finite element analysis model was built. According to the actual working condition, the heat source and the heat transfer coefficient of every part are calculated. On this basis, the temperature field and temperature rises were gotten in Ansys software. The other way is temperature rises experiment on the motorized spindle test platform. The result was shown in the form of curve. These two ways shown the same result: the highest temperature rise appears in the area of electromotor, then followed by the rolling bearing .The result provides the necessary theory basis for optimizing the structure of the motorized spindle and establishes a basis for the research and application about the high speed spindle.

Thermal Characteristics Analysis of Nuclear Power CNC Wheel Groove Milling Machine Based on Finite Element

2013 ◽  
Vol 816-817 ◽  
pp. 1100-1104
Author(s):  
Zhi Wei Li ◽  
Dan Lu Song
Keyword(s):  
Finite Element ◽  
Machine Tool ◽  
Nuclear Power ◽  
Optimization Design ◽  
Thermal Structure ◽  
Thermal Characteristics ◽  
Machining Accuracy ◽  
Accuracy Evaluation ◽  
Milling Machine ◽  
Element Analysis

For nuclear power CNC wheel groove milling machine in the work under the influence of a variety of heat sources, establish the finite element model of machine, using finite element analysis software ANSYS, analysis and thermal-structure coupling of heat source in the processing state mechanism, thermal key points out machine, the effect of deformation on the machine geometric accuracy evaluation of heat, and the machine thermal optimization analysis of corresponding, deformation of machine in the three direction. The results show that: the machine in machining spindle heat is an important factor affecting the machining accuracy of machine tools, and heat through various ways to machine tool bed, causing warping, guide rail bending, through this analysis provides reference for analysis and optimization design for the machine tool thermal deformation.

Analysis and Optimization of Thermal Characteristics for NC Lathe Spindle System

2011 ◽  
Vol 341-342 ◽  
pp. 291-295
Author(s):  
Ru Fu Hu ◽  
Xiao Ping Chen ◽  
Huan Xin Yao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Rise ◽  
High Speed ◽  
Thermal Deformation ◽  
Thermal Characteristics ◽  
Machining Accuracy ◽  
Spindle System ◽  
Modeling And Analysis ◽  
Mechanical Coupling

Improving thermal characteristics is a crucial approach for increasing machining accuracy of NC lathe. Modeling and analysis of thermal characteristics to a high speed NC lathe were implemented by using finite element method in this paper. Based on this, temperature rise characteristic of the whole spindle system was obtained. The thermal deformation of spindle system due to thermal-mechanical coupling was calculated. Layout and parameter were optimized for the radiating plate of spindle box. And this leads to a considerable reduction in the run-out error of spindle head. The optimization result reaches the expected goal.

Modelling, Identification and Control of Thermal Deformation of Machine Tool Structures, Part 2: Generalized Transfer Functions

1998 ◽  
Vol 120 (3) ◽  
pp. 632-639 ◽  
Author(s):  
S. Fraser ◽  
M. H. Attia ◽  
M. O. M. Osman
Keyword(s):  
Finite Element ◽  
Machine Tool ◽  
Real Time ◽  
Thermal Deformation ◽  
Transfer Functions ◽  
Design Stage ◽  
Machining Accuracy ◽  
Deformation Problem ◽  
Machine Tool Structure ◽  
Machine Tool Structures

With the ever increasing demand for higher machining accuracy at lower cost, thermal deformation of machine tool structures has to be minimized at the design stage, and compensated for during operation. To compensate for this type of error, two real-time process models are required to identify the magnitude of the transient thermal load and to estimate the relative thermal displacement between the tool and the work piece. Special considerations should be given to the solution of the first ill-posed inverse heat conduction model IHCP. In this paper, the concept of generalized modelling is extended to the thermal deformation problem. The results of this analysis is used to develop expressions for the generalized transfer functions of the thermal, and thermal deformation response of the machine tool structure. These transfer functions are the basic building blocks for real-time solution of the IHCP and then the deformation problem. The latter acts as a feed-back signal to the control system. Finite element simulation of the temperature field and the thermal deformation of a machine tool structure confirmed that the generalized transfer function approach can reproduce the accuracy of the finite element model but two orders of magnitude faster.

Effect of guide rail profile errors on the motion accuracy for a heavy-duty hydrostatic turntable

2019 ◽  
Vol 233 (15) ◽  
pp. 5350-5362 ◽  
Author(s):  
Yongsheng Zhao ◽  
Hongchao Wu ◽  
Congbin Yang ◽  
Ligang Cai ◽  
Zhifeng Liu
Keyword(s):  
Machine Tool ◽  
Reynolds Equation ◽  
Machining Accuracy ◽  
Guide Rail ◽  
Heavy Duty ◽  
Motion Equations ◽  
Rotating Speed ◽  
Proposed Model ◽  
Reaction Forces ◽  
Profile Errors

The motion accuracy of hydrostatic turntable is the key in improving the machining accuracy of heavy-duty machine tool. However, the motion accuracy of hydrostatic turntable depends not only on the offset load but also on the rotating speed of the turntable as well as the profile errors of the guide rails. In this paper, a simulation model is developed to analyze the effect of guide rail profile errors on the motion accuracy of hydrostatic turntable. The reaction forces of preload thrust bearing and hydrostatic circular oil pads are obtained based on the Reynolds equation of the lubricant film. The motion equations of hydrostatic turntable are derived in which the profile errors of two guide rails are considered. The results show that the motion accuracy of hydrostatic turntable can be affected by wavelength, amplitude of profile errors and speed, and offset load of turntable. Finally, the motion accuracy of heavy-duty hydrostatic turntable used in XCKA28105 type turning and milling composite machine tool is obtained by using the presented method. Comparing with the experimental results, the proposed model can be used to predict the machining accuracy caused by the profile errors of guide rails for any heavy-duty hydrostatic turntable.

Error correction technique for numerical control machine tools based on the simplex method

2021 ◽  
pp. 095440542110281
Author(s):  
Hongwei Liu ◽  
Rui Yang ◽  
Pingjiang Wang ◽  
Jihong Chen ◽  
Hua Xiang
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Simplex Method ◽  
Tool Path ◽  
Repeated Measurements ◽  
Numerical Control ◽  
Machining Accuracy ◽  
Correction Technique ◽  
Fluctuation Range ◽  
Nc Machine

The objective of this research is to develop a novel correction mechanism to reduce the fluctuation range of tools in numerical control (NC) machining. Error compensation is an effective method to improve the machining accuracy of a machine tool. If the difference between two adjacent compensation data is too large, the fluctuation range of the tool will increase, which will seriously affect the surface quality of the machined parts in mechanical machining. The methodology used in compensation data processing is a simplex method of linear programming. This method reduces the fluctuation range of the tool and optimizes the tool path. The important aspect of software error compensation is to modify the initial compensation data by using an iterative method, and then the corrected tool path data are converted into actual compensated NC codes by using a postprocessor, which is implemented on the compensation module to ensure a smooth running path of the tool. The generated, calibrated, and amended NC codes were immediately fed to the machine tool controller. This technique was verified by using repeated measurements. The results of the experiments demonstrate efficient compensation and significant improvement in the machining accuracy of the NC machine tool.

Aero-Engine Blade Deformation Control of Milling Process

2011 ◽  
Vol 308-310 ◽  
pp. 1198-1204
Author(s):  
Hui Xian Chen ◽  
Hao Li ◽  
Hai Tao Feng ◽  
Min Juan Du
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Error Compensation ◽  
Leaf Blade ◽  
Tool Path ◽  
Iterative Solution ◽  
Helical Milling ◽  
Machining Accuracy ◽  
Element Simulation ◽  
Compensation Plan

The leaf blade manufacture precision's influencing factors are numerous, and they have coupling relationship each other. So it is difficult to peel out a single factor on the influencing regularity of the blade's machining accuracy. By researching the engine blades of helical milling state under the existing fixture, the leaf blade deformable model based on the instantaneous milling strength was established. Meanwhile, the off-line multi-level error compensation plan was proposed based on the processing surface static error forecasts and compensation. In order to revise the primitive NC tool path code and eliminate the processing distortion inaccuracy, the elastic deformity on each knife position spot is solved on the basis of iterative solution, using the finite element simulation and milling strength model. By using ANSYS finite element simulation, it receives the real-time error compensation of the tool path. And then The experiment has proven the accuracy and the usability of the compensation plan.

Thermal Deformation Analysis for the Guideway of Large-Type CNC Lathe Based on Finite Element Method

2011 ◽  
Vol 58-60 ◽  
pp. 198-204
Author(s):  
Feng Shou Zhang ◽  
Don Gyan Wang ◽  
Jian Ting Liu ◽  
Feng Kui Cui
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Thermal Deformation ◽  
Thermal Characteristics ◽  
Thermal Error ◽  
Deformation Analysis ◽  
Element Analysis ◽  
Large Type ◽  
Cnc Lathe ◽  
Optimizing Design

Friction between the guideway and the bench of large-type CNC lathe will cause thermal deformation of the guideway, which causes processing error of the lathe，thereby reduces machining precision of the workpiece. The authors establish the mathematical model of temperature field and thermal deformation of the guideway in the work process, numerically simulate the guideway thermal characteristics by ANSYS finite element analysis software, and obtain the distribution regularities of temperature field and thermal deformation and their major influencing factors, which provide a theoretical basis for optimizing design and thermal error compensation design of the lathe guideway.

scholarly journals Effect of Supply Cooling Oil Temperature in Structural Cooling Channels on the Positioning Accuracy of Machine Tools

2019 ◽  
Vol 35 (6) ◽  
pp. 887-900 ◽  
Author(s):  
K.-Y. Li ◽  
W.-J. Luo ◽  
M.-H. Yang ◽  
X.-H. Hong ◽  
S.-J. Luo ◽  
...  
Keyword(s):  
Machine Tool ◽  
Thermal Deformation ◽  
Thermal Error ◽  
Machining Accuracy ◽  
Feed System ◽  
Positioning Accuracy ◽  
Cooling Channels ◽  
Position Accuracy ◽  
Machine Tool Accuracy ◽  
Volume Method

ABSTRACTIn this study, the thermal deformation of a machine tool structure due to the heat generated during operation was analyzed, and embedded cooling channels were applied to exchange the heat generated during the operation to achieve thermal error suppression. Then, the finite volume method was used to simulate the effect of cooling oil temperature on thermal deformation, and the effect of thermal suppression was experimentally studied using a feed system combined with a cooler to improve the positioning accuracy of the machine tool. In this study, the supply oil temperature in the structural cooling channels was found to significantly affect the position accuracy of the moving table and moving carrier. If the supply oil temperature in the cooling channels is consistent with the operational ambient temperature, the position accuracy of the moving table in the Y direction and the moving carrier in the X and Z directions has the best performance under different feed rates. From the thermal suppression experiments of the embedded cooling channels, the positioning accuracy of the feed system can be improved by approximately 25.5 % during the dynamic feeding process. Furthermore, when the hydrostatic guideway is cooled and dynamic feeding is conducted, positioning accuracy can be improved by up to 47.8 %. The machining accuracy can be improved by approximately 60 % on average by using the embedded cooling channels in this study. Therefore, thermal suppression by the cooling channels in this study can not only effectively improve the positioning accuracy but also enhance machining accuracy, proving that the method is effective for enhancing machine tool accuracy.

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