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

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.

Author(s):  
Dennis Freiburg ◽  
Rouven Hense ◽  
Petra Kersting ◽  
Dirk Biermann

Milling is a machining process in which material removal occurs due to the rotary motion of a cutting tool relative to a typically stationary workpiece. In modern machining centers, up to and exceeding six degrees of freedom for motion relative to the tool and workpiece are possible, which results in a very complex chip and force formation. For the process layout, simulations can be used to calculate the occurring process forces, which are needed, e.g., for the prediction of surface errors of the workpiece, or for tool wear and process optimization examinations. One limiting factor for the quality of simulation results is the parametrization of the models. The most important parameters for milling simulations are the ones that calibrate the force model, as nearly every modeled process characteristic depends on the forces. This article presents the combination of a milling simulation with the Broyden–Fletcher–Goldfarb–Shanno (BFGS) optimization algorithm for the fast determination of force parameters that are valid for a wide range of process parameters. Experiments were conducted to measure the process forces during milling with different process parameters. The measured forces serve as basis for tests regarding the quality of the determined force parameters. The effect of the tool runout on the optimization result is also discussed, as this may have significant influence on the forces when using tools with more than one tooth. The article ends with a conclusion, in which some notes about the practical application of the algorithm are given.


Author(s):  
Petru A. Pop ◽  
Gheorghe Bejinaru-Mihoc ◽  
Ioan Olaru

The machining of cylindrical gears by gear shaping with gear wheel-cutter has accompanied of known cutting errors met at rolling gears cutting: pitch error, total pitch error, profile tooth error, circular runout, etc. The technical papers consider that two aspects can analyze gears shaping precision with gear wheel-cutter: first by the analysis of profile gear cutting errors, and second by profile gear cutting errors in “closing zone of teeth gear”, with a main factor according of stiffness machine tools. The analysis of stiffness machine has done with the values displacements and relative rotations of machine subassemblies to a fixed datum system and two mobile datum systems, in dependence of load applied during idle running or gear shaping process, could be defined three stiffness’s: static, quasi-static and dynamic stiffness. During the cutting process, the variation predictable distance between cutter axe and wheel-workpiece axe is important. This study is carrying out by stiffness machine analysis in radial direction of OY axe. The paper has proposed a method of quasi-static stiffness machine determination of gear shaping process with wheel-cutter. During cutting process occurs altering positions between subassemblies of ram-toolholder and rotated table, even is used finishing working conditions. The research has done by an integration system “force-displacement”, formed by a dynamometer adaptable of gear machine-MD 250, which allowing the acquisition of cutting forces on three axes and displacements of ram-toolholder-workpiece during machining process. The measurement has done in “closing zone of gear”, respectively the outside of that, due to determination of stiffness machine tools. In addition, this research presented the assessing of working accuracy of gear shaping machine with gear wheel-cutter.


2012 ◽  
Vol 21 (S6) ◽  
pp. 860-867 ◽  
Author(s):  
Christoph Reutlinger ◽  
Carol Hasler ◽  
Klaus Scheffler ◽  
Philippe Büchler

1987 ◽  
Vol 5 (1) ◽  
pp. 92-101 ◽  
Author(s):  
J. A. A. Miller ◽  
A. B. Schultz ◽  
G. B. J. Andersson

2016 ◽  
Vol 686 ◽  
pp. 39-44 ◽  
Author(s):  
Józef Gawlik ◽  
Joanna Krajewska-Śpiewak ◽  
Wojciech Zębala

The chip-forming precision machining process plays a significant role in the mechanical technology. In planning of machining operation, it is crucial to supply the information about the possible minimal value of the machining allowance. For the technologist, when planning the machining operation, it is important to define the minimal thickness of cutting layer correctly. This article presents a new method of describing the start of decohesion process in a workpiece, meaning the determination of the minimal thickness of cutting layer based on the AE signal generated in the cutting zone. The research conducted on the turning of an alloy steel and the analysis of the AE signal strength confirmed that the proposed method opens new possibilities in quickening the identification of the minimal thickness of cutting layer under normal machining conditions.


2019 ◽  
Vol 109 (09) ◽  
pp. 650-655
Author(s):  
C. Menze ◽  
D. Becker ◽  
T. Stehle ◽  
H.-C. Möhring ◽  
N. Helfesrieder ◽  
...  

Industrieroboter bieten eine große Flexibilität und einen großen Arbeitsraum bei verhältnismäßig geringen Investitionskosten. Gegenüber spanenden Werkzeugmaschinen sind die Steifigkeiten und Bahngenauigkeiten von Robotern jedoch geringer. Dennoch bieten sie für die Holzbearbeitung großes Potential, da die Prozesskräfte gewöhnlich kleiner und die Toleranzen höher sind als im Metallbereich. Dieser Beitrag stellt einen Vergleich der erzielbaren Bauteilqualitäten bei der Holzbearbeitung mit Industrierobotern und Bearbeitungszentren vor.   Industrial robots provide great flexibility and a large working area at relatively low investment costs. However, their stiffness and path accuracy are generally lower compared to machine tools. Still, they offer high potential for woodworking, as the process forces are usually smaller and the tolerances higher than in the metal industry. This paper presents a comparison of the achievable component qualities in woodworking with industrial robots and machining centers.


2013 ◽  
Vol 371 ◽  
pp. 431-435 ◽  
Author(s):  
Claudiu Obreja ◽  
Gheorghe Stan ◽  
Lucian Adrian Mihaila ◽  
Marius Pascu

With a view of increasing the productivity on CNC machine tools one of the main solution is to reduce, as much as possible, the auxiliary time consumed with the set-up and replacement of the tools and work pieces engaged in the machining process. Reducing the total time of the tool changing process by the automatic tool changer system can be also achieved through minimizing the number of movements needed for the actual exchange of the tool, from the tool magazine to the machine spindle (the optimization of the tool changing sequences). This paper presents a new design method based on the tree-graph theory. We consider an existing automatic tool changing system, mounted on the milling and boring machining centre, and by applying the new method we obtain all the possible configurations to minimize the tool changing sequence of the automatic tool changer system. By making use of the method proposed we obtain the tool changing sequences with minimum necessary movements needed to exchange the tool. Reconfiguring an existing machine tool provided with an automatic tool changer system by making use of the proposed method leads to obtaining the smallest changing time and thus high productivity.


Sign in / Sign up

Export Citation Format

Share Document