scholarly journals Machining Accuracy Enhancement of a Machine Tool by a Cooling Channel Design for a Built-in Spindle

2020 ◽  
Vol 10 (11) ◽  
pp. 3991
Author(s):  
Kun-Ying Li ◽  
Win-Jet Luo ◽  
Shih-Jie Wei
Keyword(s):  
Machine Tool ◽  
Thermal Deformation ◽  
Simulation Analysis ◽  
Machining Accuracy ◽  
Manufacturing Cost ◽  
Cooling Channel ◽  
Channel Design ◽  
Warm Up ◽  
Maximum Decrease ◽  
Operational Time

This study presents a multiphysics simulation analysis that was performed for the cooling channel of a built-in spindle. The design of experiments (DOE) method was employed to optimize the dimension of the cooling channel, and a practical machining experiment was performed to validate the effect of the design. In terms of the temperature, pressure drop, thermal deformation, manufacturing cost, and initial cost considerations, the paralleling type cooling channel of the front bearing and the helical type cooling channel of the motor were adopted in the study. After the optimal design of the cooling channel was applied, the bearing temperature was reduced by a maximum decrease of 6.7 °C, the spindle deformation decreased from 53.8 μm to 30.9 μm, and the required operational time for attaining the steady state of the machine tool was shortened from 185.3 min to 132.6 min. For the machining validation, the spindle with the optimal cooling channel design was employed for vehicle part machining, the flatness of the finished workpiece was increased by 61.3%, and the surface roughness (Ra) was increased by 52%. According to the findings for the optimal cooling channel, when the spindle cooling efficiency is increased by the optimal cooling channel design, the thermal deformation and warm-up period can be reduced effectively, and the machining precision can be enhanced. This method is an efficient way to increase the accuracy of a machine tool.

scholarly journals Optimized Design of Precision EDM Machine Tool based on CAE Simulation and Modal Testing Technology

2021 ◽  
Vol 252 ◽  
pp. 02036
Author(s):  
Jianyong Liu ◽  
Yanhua Cai ◽  
Haifeng Zhang ◽  
Liantong Ding
Keyword(s):  
Machine Tool ◽  
Thermal Deformation ◽  
Simulation Analysis ◽  
Design Method ◽  
The Body ◽  
Modal Testing ◽  
Weak Links ◽  
Machining Accuracy ◽  
Optimized Design ◽  
Static Stiffness

For precision EDM equipment, in addition to the static stiffness of the body of the machine, the dynamic characteristics of the body and the ambient temperature are also the key factors that affect the machining accuracy of the workpieces. In this paper, through the modal simulation analysis of the machine tool that with the sheet metal shell, the weak points of the EDM machine tool are determined. Through thermal stress simulation analysis, the thermal deformation law of the workpieces mounting table is determined, and a solution to reduce thermal deformation is proposed. Through machine tool ODS (operating deflection shapes) test and analysis, the weak links of the machine tool's body in actual processing are determined. Through the above optimization analysis, the foundation has been laid for improving the dynamic and static accuracy of the precision machine tool. The research method in this paper makes up for the deficiency of the machine tool design method based on static stiffness.

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.

Numerical Simulation Analysis of Temperature Field for Motorized Spindle of High-Grade CNC Machine Tool Based on ANSYS

2010 ◽  
Vol 455 ◽  
pp. 33-36 ◽  
Author(s):  
C.Q. Li ◽  
Xiao Dong Zhang ◽  
Q. Zhang ◽  
H. Li
Keyword(s):  
Temperature Field ◽  
Machine Tool ◽  
High Speed ◽  
Thermal Deformation ◽  
Simulation Analysis ◽  
Transient Temperature ◽  
High Grade ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Motorized Spindle

To solve the problems that the thermal deformation of the High-Grade CNC machine tool has much effect on accuracy and quality of the produces, the structure characteristics of the high speed motorized spindle is firstly introduced in this paper. Then one type of motorized spindle and supporting structure are selected, and the thermal boundary parameters are calculated. Much more the static and transient temperature field are simulated by using FEA software ANSYS in one working condition. At last, the main measures to improve the uneven temperature field and the plans to reduce the thermal deformation are put forward, which are provided some technical bases for the equipment to achieve the high-speed and high-precision machining.

Modelling, Identification and Control of Thermal Deformation of Machine Tool Structures, Part 5: Experimental Verification

1999 ◽  
Vol 121 (3) ◽  
pp. 517-523 ◽  
Author(s):  
S. Fraser ◽  
M. H. Attia ◽  
M. O. M. Osman
Keyword(s):  
Control System ◽  
Machine Tool ◽  
Thermal Deformation ◽  
Transfer Functions ◽  
Integrated System ◽  
Design Stage ◽  
Machining Accuracy ◽  
Deformation Model ◽  
Component Structure ◽  
Artificial Heat

Machining accuracy is more often governed by thermal deformation of the machine tool structure than by static stiffness and dynamic rigidity. Since thermally induced errors cannot completely be eliminated at the design stage, the use of control and compensation systems is an inevitable course of action. Existing control systems are based on two different approaches; the use of empirical compensation function, and on-line execution of numerical simulation models. To overcome the limitations of these methods, a new control system has recently been proposed by the authors. This system, which is based on the concept of generalized modelling, incorporates a realtime inverse heat conduction problem IHCP solver to estimate the transient thermal load applied to the structure. With this information, the relative thermal deformation between the tool and the workpiece is estimated and used as a feedback control signal. In previous parts of this series, computer simulation test cases were carried out to examine the dynamic response, accuracy and stability of the system. In the present study, the performance of various components of the control system, specifically, the IHCP solver, the thermal deformation estimator, and the feedback controller are verified experimentally using a three-component structure. The results showed that the derived generalized thermoelastic transfer functions and algorithms are indeed quite accurate in predicting and controlling the transient thermoelastic response behaviour of a predominantly linear structure. The results showed that the a IHCP solver is inherently stable even when the temperature measurements are contaminated with random errors. The excellent computational efficiency of the integrated system is shown to be well suited for real-time control applications involving multi-dimensional structures, achieving a control cycle of less than 0.5 second. The experimental results showed that in real structures higher modes can be present, and therefore, a fourth order deformation model should be used to improve the prediction accuracy. The proposed PID control system, with feedforward branches, was capable of reducing thermal deformations of the order of 200 μm to levels below ±8 μm. These results also demonstrated the effectiveness of artificial heat sources as a control actuation mechanism, in spite of their inherent limitations, namely, thermal inertia, coupledness, and unidirectionality.

Cooling Channel Design for a Built-in Spindle of a Machine Tool

2020 ◽  
Vol 1500 ◽  
pp. 012031
Author(s):  
Kun-Ying Li ◽  
Win-Jet Luo ◽  
Shih-Jie Wei ◽  
Yan-sin Liao
Keyword(s):  
Machine Tool ◽  
Cooling Channel ◽  
Channel Design

Design Optimization of Machine-Tool Structures Considering Manufacturing Cost, Accuracy, and Productivity

1984 ◽  
Vol 106 (4) ◽  
pp. 531-537 ◽  
Author(s):  
M. Yoshimura ◽  
Y. Takeuchi ◽  
K. Hitomi
Keyword(s):  
Machine Tool ◽  
Design Optimization ◽  
Structural Model ◽  
Structural Models ◽  
Optimization Method ◽  
Machining Accuracy ◽  
Manufacturing Cost ◽  
Structural Members ◽  
Machine Tool Structures ◽  
Machining Productivity

This paper proposes a multiphase design optimization method using simplified structural models in order to minimize manufacturing cost of machine-tool structures under constraints of machining accuracy, machining productivity, and local deformations of structural members. The manufacturing cost is divided into three components—material cost, welding cost, and machining cost, each of which is minimized in the multiphase optimization process. The method is demonstrated on a structural model of a double-column machine tool.

Study on the Restraint Method of Thermal Deformation in the Machine Tools

2013 ◽  
Vol 797 ◽  
pp. 603-608
Author(s):  
Kyosuke Umezu ◽  
Kazuhito Ohashi ◽  
Shinya Tsukamoto
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Thermal Deformation ◽  
Estimation Accuracy ◽  
Machining Accuracy ◽  
Long Time ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Automatic Mass ◽  
Main Factor

In the NC machine tools for automatic mass production processing lines, it is demanded that high stable machining accuracy is maintained for a long time. The main factor of deterioration in machining accuracy depends on the thermal deformation of machine tool, and the measures are one of the most important issues in the machine tool design. The thermal deformation is practically estimated by the temperature changing state of machine tools based on obtained data of their thermal deformation chracteristics. The estimation accuracy of thermal deformation depends on the thermometry points of machine tool greatly. This study describes an approach to the most suitable thermometry points in machine tool to determine the effective thermal deformation measures experimentally. As a result, the existence of points where the temperature of components changed with relation to thermal deformation very closely was confirmed.

Study on Thermal Deformation of Machine Tool under Different Environment Temperature

2013 ◽  
Vol 441 ◽  
pp. 576-579
Author(s):  
Fan Jie Luo ◽  
Dan Lu Song ◽  
Zhi Wei Li ◽  
Qing Yun Jian
Keyword(s):  
Machine Tool ◽  
Thermal Deformation ◽  
Field Analysis ◽  
Machining Accuracy ◽  
Milling Machine ◽  
Element Analysis ◽  
Front End ◽  
Vertical Milling ◽  
Environment Temperature ◽  
Vertical Milling Machine

Taking XK5034 vertical milling machine as the research object, its thermal characteristic's finite element analysis has been carried out through the ANSYS. The front-end of the spindle mainly affects the machining accuracy of machine tool, so on the basis of the temperature field analysis, its thermal deformation was analyzed under different environment temperature, and the change rules between environment temperature and thermal deformation of the front of the spindle was also acquired. The results show that the influence of machine tool thermal deformation under different temperature is obvious.

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.

The Thermal Characteristics Analysis of a Super Hydrostatic Guideway

2012 ◽  
Vol 248 ◽  
pp. 162-166 ◽  
Author(s):  
Jian Hua Wang ◽  
Wei Du ◽  
Zhi Feng Liu ◽  
Li Gang Cai
Keyword(s):  
Machine Tools ◽  
Thermal Deformation ◽  
Simulation Analysis ◽  
Thermal Characteristic ◽  
Thermal Characteristics ◽  
Thermal Error ◽  
Element Model ◽  
Machining Accuracy ◽  
Characteristics Analysis ◽  
Processing Errors

This paper established the finite element model of a hydrostatic guideway. Based on the thermal characteristic simulation analysis, the temperature field and thermal deformation of the guideway were obtained. The analysis results show that the oil film temperature increment will cause thermal deformation of the guideway and processing errors. The errors will influence the machining accuracy of machine tools. The analysis results provide certain theory basis for the research on the above influence. And then the results also give certain reference for the research on the thermal error compensation of machine tools.

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