Avoiding Collision Damage of Motor Spindles through an Innovative Overload Protection System

2014 ◽  
Vol 1018 ◽  
pp. 357-364 ◽  
Author(s):  
Matthias Berger ◽  
Dennis Korff
Keyword(s):  
Machine Tools ◽  
Contact Forces ◽  
Protection System ◽  
Current Status ◽  
Working Space ◽  
Overload Protection ◽  
Main Components ◽  
Machine Structure

Different causes lead to unforeseen contact situations between moving components in the working space of machine tools. These collisions can result in damage of the machine components. High cost and machine downtime are the consequences. This article presents a solution for the reduction of contact forces in case of collision. The damages of the machine structure and the main components like the motor spindle can be successfully avoided. Further a modified mechanism with higher stiffness and better process properties of the protection system will be described and compared to the current status.

Last-Verlagerungsverhalten von Kugelgewindetrieben/Load displacement behavior on ball screws

2020 ◽  
Vol 110 (05) ◽  
pp. 295-298
Author(s):  
Christian Brecher ◽  
Florian Kneer ◽  
Stephan Neus
Keyword(s):  
Machine Tools ◽  
Machining Process ◽  
Ball Screw ◽  
Elastic Displacement ◽  
Technical Paper ◽  
Process Forces ◽  
Displacement Behavior ◽  
Load Displacement ◽  
Machine Structure

Die axiale Steifigkeit von Kugelgewindetrieben ist wesentlich für das Betriebsverhalten von Werkzeugmaschinen. Während der Bearbeitung werden die Prozesskräfte über den Kugelgewindetrieb in die Maschinenstruktur übertragen. Kugelgewindetriebe tragen daher maßgeblich zur Qualität und Produktivität von Werkzeugmaschinen bei. Dieser Beitrag beschreibt eine Methode zur messtechnischen, prüfstandsgebundenen Ermittlung des Last-Verlagerungsverhaltens an Kugelgewindetrieben.   The axial elastic displacement of ball screws are essential for the operating behavior of machine tools. During machining, process forces must be transmitted to the machine structure via the ball screw. Ball screws contribute significantly to the quality and productivity of machine tools. This technical paper describes a methodology for the metrological determination of the load-displacement behavior on ball screws.

Research on Modal Analysis of Precision Micro Slitting Turn-Milling Machine Tool Based on Hammer Experimental Method

2019 ◽  
Vol 295 ◽  
pp. 67-72
Author(s):  
Zhong Peng Zheng ◽  
Xin Yang Jiang ◽  
Xin Jin
Keyword(s):  
Machine Tool ◽  
Modal Analysis ◽  
Experimental Method ◽  
Machine Tools ◽  
Processing Parameters ◽  
Milling Machine ◽  
Vibration Model ◽  
Vibration Modal ◽  
Turn Milling ◽  
Machine Structure

In order to improve the dynamic stability of precision micro slitting turn-milling machine tools, reduce or avoid the vibration problem during the cutting process, optimize the machine structure and processing parameters, the modal analysis of precision micro slitting turn-milling machine tool based on hammer experimental method was researched. In this paper, by analyzing the mechanism of precision micro slitting turn-milling machine tools, the multi degree-of-freedom mathematical vibration model of precision slitting turn-milling machine tools is constructed. The precision micro turn-milling machine tool is analyzed based on the hammer experiment analysis. The modal analysis obtained the first five natural frequencies and resonance speeds of the precision micro slitting turn-milling machine tool,including ST26, NN-25UB8K2 and NN-20UB87. The research results show that hammer experimental method can evaluate the vibration modal analysis of precision micro slitting turn-milling machine tools to some extent. The experimental modal analysis results guide and optimize the structural design and processing technology of precision micro slitting turn-milling machine tools.

scholarly journals A Framework for Enhancing ICT Competency of Universities in Sri Lanka

2015 ◽  
Vol 10 (5) ◽  
pp. 45 ◽  
Author(s):  
Champa Hewagamage ◽  
K. Priyantha Hewagamage
Keyword(s):  
Learning Environment ◽  
Knowledge Workers ◽  
Virtual Learning ◽  
Virtual Learning Environment ◽  
Qualitative Assessment ◽  
Current Status ◽  
Sri Lankan ◽  
Infrastructure Development ◽  
Job Tasks ◽  
Main Components

In the current information society, the need for securing human resources acquired with ICT competency is becoming a significant factor. Information Communication Technology (ICT) competency describes more than awareness or driving license level of using computing facilities and networking services to carry out different tasks. Undergraduates of a university will become knowledge workers in the society and they should acquire the knowledge, skills and attitudes using the modern ICT technology to carry out their job tasks effectively. This paper presents the current status of ICT Competency in Sri Lankan Universities with respect to both the knowledge and skill requirements of knowledge workers in the job market. However, there are several obstacles are affecting this development and the paper discuss the qualitative assessment of these obstacles in detail. In this study, we propose a new framework for enhancing the ICT Competency among a large number of undergraduates in the University system. This framework consists of two main components namely Infrastructure Development and Virtual Learning Environment. In the component, Infrastructure Development new facilities are provided such as computers, networks and Internet facilities, human resource management and other support services in order to solve the problems identified. Under the Virtual Learning Environment, we propose three levels for undergraduates to address the curriculums of ICT competency. The first two levels are declared with respect to the common ICT Competency Certification and level 3 is declared considering special requirements of curriculum or subject streams.

scholarly journals Working Space of Parallel Mechanism Type Machine Tools and its Simplified Expression.

2000 ◽  
Vol 66 (4) ◽  
pp. 584-588
Author(s):  
Xiaoming ZHAO ◽  
Tetsuro SHIBUKAWA ◽  
Taizo TOYAMA ◽  
Kazuya HATTORI ◽  
Masaomi TSUTSUMI
Keyword(s):  
Machine Tools ◽  
Parallel Mechanism ◽  
Working Space ◽  
Type Machine

scholarly journals Characteristics of an Effective Child Protection System in the European and International Contexts

2021 ◽  
Author(s):  
Mariëlle R. Bruning ◽  
Jaap E. Doek
Keyword(s):  
Human Rights ◽  
Child Protection ◽  
Protection System ◽  
European Convention ◽  
The European Union ◽  
Rights Of The Child ◽  
European Court ◽  
Core Elements ◽  
Protection Of Human Rights ◽  
Main Components

AbstractIn the European context, an understanding that States are responsible for an effective child protection system is well established. Further, all 47 members of the CoE have adopted the European Convention for the Protection of Human Rights and Fundamental Freedoms, and all European countries have ratified the UN Convention on the Rights of the Child (CRC). Thus, States have come to understand their responsibility in terms of the child’s right to protection. The aim of this article is to explicate core elements of an effective child protection system within a child’s rights framework. This aim is accomplished by highlighting and providing analysis of the principles set forth in the CRC and further elaborated in General Comment No. 13 (2011) and by the UN Children’s Fund (UNICEF), the main components of policies and other relevant documents of the European Union (EU) and the Council of Europe (CoE), and caselaw from the European Court of Human Rights (ECrtHR) and then presenting recommendations for an effective State-run child protection system.

Optimized Design and Performance Study of High Speed Five-Axis Machine Tools

2020 ◽  
Author(s):  
Tzu-Chi Chan ◽  
Jyun-Sian Yang
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Machine Tools ◽  
High Speed ◽  
Spectral Response ◽  
Work Piece ◽  
Static And Dynamic Characteristics ◽  
Five Axis ◽  
Speed Accuracy ◽  
Machine Structure

Abstract With the development of machine tools trending toward high precision, intelligence, multi-axis, and high speed, the improvement of the processing performance and rigidity of the machine is considerably important. The objective of this study is to design of a high-speed five-axis moving-column machine tool and perform structural analysis and optimization. We study the static and dynamic characteristics of the five-axis machine tool, design and improve the mechanical structure, and optimize the structural configuration of the machine. The entire machine structure is further analyzed and enhanced to improve its static and dynamic characteristics, including static rigidity, modal, transient, and spectral response characteristics. The static and dynamic characteristics of the machine structure directly affect the machine processing performance, and further affect the work piece precision machined by the tool. Through this study, the design technology for speed, accuracy, and surface roughness of the machine tool are further improved.

Decision Method of Target Shape Position and Orientation Corresponding to Actual Objects

2017 ◽  
Vol 11 (2) ◽  
pp. 251-257
Author(s):  
Naoya Shimada ◽  
◽  
Noboru Nagashima ◽  
Keiichi Nakamoto
Keyword(s):  
Machine Tools ◽  
3D Models ◽  
Numerical Control ◽  
Target Shape ◽  
Control Programs ◽  
Decision Method ◽  
Position And Orientation ◽  
High Flexibility ◽  
Machining Operations ◽  
Machine Structure

Multi-tasking machine tools are popular owing to properties such as high flexibility and productivity. It is essential for an operator to avoid collisions between the machine structure and workpieces as machine tools realize complicated motions. Thus, a machine simulator is widely used prior to machining operations to solve this problem. However, unexpected collisions often occur in a commercial machine simulator when the setup of a workpiece or a jig differs from the 3D models created in advance. Therefore, this study proposes a machine simulator that utilizes 3D models created by measuring the shape and position of the workpiece and jig on the machine tool. In a case in which the workpiece differs from the desired workpiece, it is necessary to determine a suitable position and orientation of the target shape based on the obtained objects to modify NC (Numerical Control) programs. In this study, a decision method of the position and orientation of target shape is devised such that it corresponds to actual objects obtained by on-machine measurement.

Current Status and Technical Issues of Ultra-precision Machine Tools

2014 ◽  
Vol 31 (3) ◽  
pp. 189-197 ◽  
Author(s):  
Jeong Seok Oh ◽  
Chang-Ju Kim ◽  
Chun Hong Park ◽  
Young Jae Choi
Keyword(s):  
Machine Tools ◽  
Current Status ◽  
Precision Machine ◽  
Ultra Precision ◽  
Technical Issues ◽  
Precision Machine Tools
Sign in / Sign up

Export Citation Format

Share Document