Analysis and Simulation of Screw Joint in CNC Machine Tool

2011 ◽  
Vol 141 ◽  
pp. 203-207
Author(s):  
Ya Wei Zhang ◽  
Wei Min Zhang

CNC machine tools has always screw joints in its feed drive systems; In order to obtain good performance of CNC machine tool, it is necessary to model the screw joint with more accuracy and to research its influence on the vibration characters of the feed drive system. In this paper, the screw joint is analyzed by multi-body system theory and is modeled as flexible multi-body; Its mathematical describe of constraint condition is given by the modeling of screw joint. A revise factor is introduced into the process of FEM simulation to reflect the deformation in the screw joint. By this way, the effect of deformation in the screw joint is researched in the modeling under the ANSYS circumstance, the harmonic response under considering deformation contrast to that of without deformation. From the analysis in the simulation, it is necessary to take the deformation of screw joint into account.

2011 ◽  
Vol 5 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Burak Sencer ◽  
◽  
Yusuf Altintas ◽  

An identification technique is introduced for identifying closed loop transfer function of machine tool’s feed drive systems to be used in simulation of the tracking and contouring performance of Computer Numerical Controlled (CNC) machine tools. The identification is performed from air-cutting tests utilizing only standard G-codes containing linear motion commands. A general transfer function model is derived for representing the closed loop tracking response of the feed drive system. The model considers the drive to be controlled by commonly used controller schemes such as P-PI Cascade, PID or the Sliding Mode Controller (SMC) with feed-forward dynamic and friction compensation. The parameters of the model transfer function are fitted tominimize the discrepancy between the actual and predicted axis position on the axis. In order to guarantee the stability of the identified model transfer function, bounds on the pole locations are imposed. The resultant constrained non-linear optimization problem is solved efficiently using the Particle Swarm Optimization (PSO) method. For achieving reliable convergence of the stochastic PSO algorithm, a parameter tuning strategy is presented. Simulation and experimental studies show that the identified feed drive model captures the fundamental dynamics of the drives system accurately for simulating their closed loop response. Combined with the kinematics of the machine, contouring errors of 5-axis CNC machine tools during simultaneous multi-axis motion are predicted.


2014 ◽  
Vol 496-500 ◽  
pp. 816-822
Author(s):  
Qiang Cheng ◽  
Hong Wei Zhao ◽  
Li Gang Cai ◽  
Pei Hua Gu

Machining accuracy has always been a key problem to machine tool. Machine errors are caused by a variety of error factors among which the geometric error is a key element. An accuracy model of the 3-axis CNC machine tool is established in this paper with multi-body system (MBS).And based on the accuracy model, the mathematical model of roundness error also built up. At last, the influence of CNC machine tools turntable angle error to roundness error of machined hole is analyzed.


2016 ◽  
Vol 841 ◽  
pp. 133-138
Author(s):  
Radu Eugen Breaz ◽  
Sever Gabriel Racz ◽  
Octavian Bologa ◽  
Melania Tera

The accuracy of CNC machine-tools is heavily influenced by the correct tuning of the feed drives controllers. While an initial tuning is performed by the machine-tool manufactures, in time the values have to be changed by the user in order to preserve positioning and contouring accuracy of the machine. This paper presents a model of a CNC feed drive, for a particular CNC machine-tool, but with a high degree of generality. The objective is to provide the user the necessary knowledge, together with a simple, yet accurate simulation tool, in order to assist him in the process of tuning the controllers.


2015 ◽  
Vol 772 ◽  
pp. 229-234
Author(s):  
Radu Eugen Breaz ◽  
Octavian Bologa

This paper presents some simulation based upon a dynamic model of a feed-drive within the structure of a CNC machine tool. A DC servomotor was considered as actuation device for the feed drive. For a given set of parameters for the position controller, two fuzzy types of fuzzy controllers were tested by means of simulation. The first fuzzy controller was a proportional one, with one input and one output, while the second one was a two variables one, with two inputs and one outputp.


2010 ◽  
Vol 455 ◽  
pp. 621-624
Author(s):  
X. Li ◽  
Y.Y. Yu

Because of the practical requirement of real-time collection and analysis of CNC machine tool processing status information, we discuss the necessity and feasibility of applying ubiquitous sensor network(USN) in CNC machine tools by analyzing the characteristics of ubiquitous sensor network and the development trend of CNC machine tools, and application of machine tool thermal error compensation based on USN is presented.


2021 ◽  
Vol 2066 (1) ◽  
pp. 012113
Author(s):  
Weiwen Ye

Abstract Multi axis CNC machine tool has good linkage processing effect. Through the application of integral impeller in CNC machine tools, to improve the adaptability of CNC machine tools to complex surface processing parts, to improve the accuracy of multi axis CNC machine tools. The first part of this paper introduces the integral impeller and its machining characteristics; the second part introduces the basic NC machining process of integral impeller; the third part discusses the application of impeller in multi axis CNC machine tools from the creation of guide track, the simulation of integral impeller, software processing and generation. The purpose is to provide some reference for the processing and production of integral impeller.


Author(s):  
Xun Xu

The introduction of CNC machines has radically changed the manufacturing industry. Curves are as easy to cut as straight lines, complex 3-D structures are relatively easy to produce, and the number of machining steps that required human action has dramatically reduced. With the increased automation of manufacturing processes with CNC machining, considerable improvements in consistency and quality can be achieved. CNC automation reduced the frequency of errors and provided CNC operators with time to perform additional tasks. CNC automation also allows for more flexibility in the way parts are held in the manufacturing process and the time required to change the machine to produce different components. In a production environment, a series of CNC machines may be combined into one station, commonly called a “cell”, to progressively machine a part requiring several operations. CNC controller is the “brain” of a CNC machine, whereas the physical configuration of the machine tool is the “skeleton”. A thorough understanding of the physical configuration of a machine tool is always a priority for a CNC programmer as well as the CNC machine tool manufacturers. This chapter starts with a historical perspective of CNC machine tools. Two typical types of CNC machine tools (i.e. vertical and horizontal machining centres) are first discussed. Tooling systems for a CNC machine tool are integral part of a CNC system and are therefore elaborated. Also discussed are the four principal elements of a CNC machine tool. They are machine base, machine spindle, spindle drive, and slide drive. What letter should be assigned to a linear or rotary axis and what if a machine tool has two sets of linear axes? These questions are answered later in the chapter. In order for readers to better comprehend the axis and motion designations, a number of machine tool schematics are given.


2013 ◽  
Vol 791-793 ◽  
pp. 967-970
Author(s):  
Guo Min Lin ◽  
Miao Shang ◽  
Wen Guang Zhang

CNC machine tool fault types, repair characteristics, the principle to be followed are described. The mechanical systems, Numerical control system, servo system fault diagnosis and repair for CNC machine tools are analyzed in detail. The strategy of the hardware faults such as main spindle part, the ball screw-nut pairs, cutter and tool change device, the strategy of the software repair are proposed.


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