Home | deutsch  | Legals | Data Protection | Sitemap | KIT
Patrick Bollig

M.Sc. Jan Klose

Team leader gearing technology
department: Manufacturing and Materials Technology
office hours: To be agreed
room: 104, Geb. 10.92
phone: +49 1523 9502590
Jan KloseTwl8∂kit edu

76131 Karlsruhe
Kaiserstraße 12


M.Sc. Jan Klose

Areas of Research:

  • Analysis and development of high performance manufacturing processes
  • Wirbeln von Gewinden und Schrauben
  • Titanbearbeitung im unterbrochenen Schnitt
  • Kinematiksimulation

 

 

General Tasks:

Publications

[ 1 ] Klotz, S.; Klose, J.; Sellmeier, V. & Schulze, V. (2017), "Variantenanalyse zur Effizienzsteigerung beim Wirbeln mit synchronem Drehen". PIA - Prozessketten im Automobilbau, eds. Denkena, B., pp. 121-129.
Abstract:
PIA - Prozesskette im Automobilbau, Tagung bei DMG Mori in Bielefeld vom 03. – 04.07.2017, Vorstellung des Themas "Variantenanalyse zur Effizienzsteigerung beim Wirbeln mit synchronem Drehen".

[ 2 ] Zanger, F.; Sellmeier, V.; Klose, J.; Bartkowiak, M. & Schulze, V. (2017), "Comparison of Modeling Methods to Determine Cutting Tool Profile for Conventional and Synchronized Whirling". Procedia Cirp, eds. Elsevier, pp. 222-227.
Abstract:
The determination of cutting tool profiles for machining operations with coupled rotational kinematics like gear and screw generation can be a complex task which is executed by either numerical or analytical methods. The cutting tool profile for whirling is derived from process parameters and desired workpiece geometry by both a numerical dexel-based model and an analytical model based on the condition of tangential motion. The models are adapted to a process variant of whirling with synchronized rotation of tool and workpiece and compared regarding accuracy, computation time and geometrical flexibility.

[ 3 ] Segebade, E.; Klose, J.; Gerstenmeyer, M.; Zanger, F. & Schulze, V. (2017), "Mechanical surface modification using cutting inserts". Proceedings of the 13th ICSP, eds. International Scientific Committee for Shot Peening, pp. 219-224.
Abstract:
The objective of this work is presenting the foundation of a true integration of mechanical surface modification and machining. This “fusion” entails mechanical surface modification parallel to the cutting process using the cutting insert as tool. While it may seem, that something similar can be achieved through classical vibration assisted machining (VAM), this is definitely not the case. The resulting relative velocity between cutting insert and workpiece will ensure the process to be firmly rooted in cutting rather than hammering of the workpiece. Since creating a setup suitable to address this issue is a big challenge in itself, it is prudent begin by establishing the general feasibility of the process. The first priority is therefore proving that cutting inserts can be used to induce surface layer states similar to those achieved by MHP-processes. The presented work addresses this validation of mechanical surface treatment using cutting inserts regarding topography, residual stresses and work hardening by model experiment.

[ 4 ] Vargas, B.; Klose, J.; Zanger, F. & Schulze, V. (2019), "Simulative and Experimental Investigation of Gear Skiving with Reduced Axis Crossing Angles ". GETPRO, eds. Forschungsvereinigung Antriebstechnik e.V. (FVA), pp. 235-244.
Abstract:
Gear skiving has been increasingly used in the production of internal gears and shows high potential to manufacture external gears with adjacent shoulders. In order to avoid tool – workpiece collision, it is possible to minimize the length of tool overrun by reducing the axis crossing angle. However, the process kinematics changes with this reduction, representing a big challenge to the process design. In order to fulfill the lack of detailed knowledge and establish its industrial practice, simulative and experimental studies with axis crossing angles Σ between 5° and 15° were conducted. A three-dimensional kinematic simulation of gear skiving based on penetration calculation was carried out to demonstrate the influence of the process parameters on the local cutting conditions. The results show that the local rake angle reaches extremely negative values at the tooth tip of the cutting tool, which is usually characterized by the highest wear rates and therefore is critical for tool life. In order to relieve the local rake angles inherent to the unfavorable kinematics, both the tool geometry and the process can be optimized. Therefore, the simulations demonstrate how the constructional rake angle and the multiple infeed strategy can positively influence the local rake angle. In order to investigate how the local cutting conditions influence the cutting forces, wear behavior and tool life, tests with single-toothed tools were conducted for different axis crossing angles. The influence of the infeed strategy, tool rake angle and maximum uncut chip thickness on the local cutting conditions were investigated and different wear behaviors for axis crossing angles less than 10° were observed, suggesting a process limit regarding tool life. For smaller angles, the influence of the investigated parameters is very pronounced and the process design is limited to a narrow but still existing parameter window.

[ 5 ] Vargas, B.; Zapf, M.; Klose, J.; Zanger, F. & Schulze, V. (2019), "Numerical Modelling of Cutting Forces in Gear Skiving". Procedia CIRP 82, eds. Elsevier B.V., pp. 455-460.
Abstract:
Gear skiving is a high-performance machining process for gear manufacturing. Due to its complex kinematics, the local cutting conditions vary during tool engagement. Particularly, the local rake angle can reach highly negative values, which have a significant effect on the cutting force. In this paper, the Kienzle force model with additional coefficients was implemented in a numerical model to calculate local cutting forces considering the influence of local rake angle. The experimental validation based on total cutting forces shows good results and indicates an increase of model accuracy for a wide parameter range by considering the rake angle Variation.

[ 6 ] Zapf, M.; Klose, J.; Zanger, F. & Schulze, V. (2019), "Process forces and surface topography when manufacturing case-hardened gears by double flanked hard skiving". VDI Berichte 2355, eds. VDI Wissensforum GmbH, pp. 1647-1658.
Abstract:
Due to its kinematics, gear skiving offers high potential for hard finish machining of internal and external gears to substitute gear grinding. Single flanked hard machining by skiving offers stable processes, because there’s only one flank in contact during cutting, but is much less productive than double flanked machining. Double flank hard finish machining is highly productive when finishing in one process step. The complex kinematics of skiving are characterized by their asymmetric chip formation due to an irregular cutting thickness of the leading and trailing flank. In this work the influence of process parameters such as cutting velocity, axial feed and radial feed of the finishing cut on the cutting forces, the resulting gear quality, flank surface quality and chip formation is investigated. The parameter studies are carried out in an analogy process using coated cemented carbide inserts with 3 cutters. Validation of the analogy process is provided by experiments with fully toothed tools. In-process force measurements supports the accurate analysis of wear mechanisms of the cemented carbide tools and the chip formation. Process forces are high due to the hardness of the workpiece and rise with the specific cutting volume. The correlation of cutting forces and surface quality with other process parameters shows more complex parameter interaction. The results support industrial acceptance of skiving as a highly productive machining process for hard finish machining and as an alternative to gear grinding and honing.

[ 7 ] Klose, J.; Zanger, F. & Schulze, V. (2019), "Gear skiving of external gears with internally geared tools". VDI Berichte 2355, eds. VDI Wissensforum GmbH, pp. 1579-1590.
Abstract:
Gear skiving is a continuously generating machining process used to manufacture internal and external gears. The tool is a pinion like cutter that is meshing with the workpiece. Cutting conditions in skiving of internal gears are considered more beneficial due to the tool enveloping the workpiece. The skiving process of internal gears is inversed to convey the enveloping tool motion to external gear manufacturing. The internal skiving tool is similar to the tool ring in whirling. Whirling is used for finish machining of threads with high surface requirements and difficult machining parameters, like orthopedic screws from titanium alloys or lead screws from hardened steels. The goal is to take advantage of the beneficial tool engagement of the whirling process for machining of gears. The cutting conditions of gear skiving with an internal tool are simulated equivalent to whirling processes. The impact of different tool diameters and axis crossing angles on cutting thickness and feed marks are studied. The results are examined and compared to an equivalent conventional skiving process. Based on the simulations, experiments with two different internal tool rings with a single straight sided cutting insert are conducted. The results show that the enveloping tool engagement results in smaller cutting thickness, more beneficial chip flow and lower surface roughness allowing higher feeds. The inversed process variant of skiving could thus be an alternative for future machining of external gears.