Chatter suppression techniques in metal cutting

Collaboration Mechanisms to Increase Productivity in the Context of Industrie 4.0

Machine tools for large parts

Recent progress of chatter prediction, detection and suppression in milling

Materials in machine tool structures

Damping models for machine tool components of linear axes

Cooling systems are used in machine tools e.g. for the cooling of the spindle, the drives, the cooling lubricant, the control cabinet and the hydraulic system. Cooling systems are one of the main consumers of energy of machine tools. This paper analyses and compares different decentral cooling systems with regard to their power consumption for an exemplary machining centre. To achieve this, the power consumption of the exemplary machining centre is analysed for different operating conditions. On the one hand a cooling system is analysed that from the perspective of energy efficiency represents state-of-the-art technology. And on the other hand a unit is examined whose energy consumption has been optimized. Besides power, displacement of tool centre point and further values as pressure, flow rate and temperature are monitored for the different machining conditions and cooling systems.

Energy Efficient Cooling Systems for Machine Tools

Holistic modelling of process machine interactions in parallel milling

Chatter in machining processes is strong dependent on the dynamic compliance behaviour of the machine tool and workpiece. The critical cutting depth where cha tter occurs is in inverse proportion to the absolut e value of the negative real part of the complex dynamic co mpliance response function of the machine tool. The refore, while designing a machine tool, its dynamic behavio ur should be investigated and optimized, e.g. by us ing the finite element method. If further design optimizati on are not possible, active damping systems might h elp avoiding chatter of the machine tool. Active dampin g systems can compensate the dynamic displacements between tool centre point of the machine tool and w orkpiece by applying dynamically correlated externa l energy (e.g. compensation forces) onto the machine structu re. Next to an explanation of the general idea and systemization of active damping systems, this paper gives examples of recent research activities in th e field of active damping systems for machine tools of the Laboratory for Machine Tools and Production Enginee ring (WZL) of Aachen University, Germany. The main chall enges while designing active damping systems for machine tools are carved out.

Avoiding chatter by means of active damping systems for machine tools

Until now the methods of experimental substructuring are rarely adopted in the machine tool sector, except for receptance coupling of tools and tool holders. In this paper, the methods are adopted to predict a general modification of a machine tool structure by coupling experimental and numerical models. This approach seems appropriate, since most design changes of machine tools affect only some part of the structure. Additionally, single components of a machine tool are easier to simulate than the complete machine tool, since they include less joints, which are usually difficult to parameterize. This contribution evaluates the proposed method, when it is applied to a single axis test bench. The slide is taken as the modified component—thus its dynamics are modeled analytically—and the remaining assembly is modeled experimentally. Particular emphasis is put on the modeling of the interfaces of the linear guides connecting the slide to the frame. Both a fixed connection between slide and frame and a linear spring-damper joint are adopted. Moreover, the dynamics of the assembly are predicted, for different positions of the slide. As a reference, the dynamics of the test bench are measured, when the slide is mounted.

Stephan Bäumler

Papers

Damping models for machine tool components of linear axes

Energy Efficient Cooling Systems for Machine Tools

Holistic modelling of process machine interactions in parallel milling

Avoiding chatter by means of active damping systems for machine tools

Prediction of Dynamics of Modified Machine Tool by Experimental Substructuring