Highly integrated hydraulic active feed unit for micro manufacturing with favorable ratio of build and work space

• Applicant: Professor Dr.-Ing. Jürgen Fleischer
• Subject Area: Production Automation and Assembly Technology ; Metal-Cutting and Abrasive Manufacturing Engineering
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 172403840

Current machine tools for micromachining are assembled with known kinematics and tested components. For this reason they feature unfavorable build spaces in comparison to the workpieces, high energy consumptions and large interfering contours reducing the complexity of the workpiece. Therefore the aim of the research priority program SPP 1476 is to develop adapted machine tools or machine tool chains out of newly derived components.Within the first grant period a miniaturized, functional highly integrated hydraulic feed unit was developed at the Institute of Production Science. This feed unit combines a high damping hydrostatic guideway with a hydraulic linear actuator featuring high force density. With this set up the hydraulic fluid is used multifunctional for propulsion, guidance and temperature control and enables a compact design.In the second grant period it is targeted to combine respectively recombine the developed modules to machine tools or machine tool chains. In so doing the developed feed unit faces new requirements: In combination respectively recombination of modules to machines, the inaccuracies of the modules itself, but also out of the combination have to be compensated. These inaccuracies add up to a large error at the tool-center-point. Besides the error compensation an ad hoc start-up procedure and a fast control integration of the feed unit into the machine is required.Therefore the hydraulic feed unit of the first grant period shall be enhanced and enabled consequently for the combination and recombination of small machine tools for small workpieces.The hydrostatic guideway with constant throttles of the first grant period cannot compensate errors. However it is basically able to compensate internal errors, errors out of the combination and recombination as well as errors of other modules. Therefore it has to be enhanced with actively controlled throttles. Actively controlled throttles shall be implemented into the feed unit. With the help of this, active hydrostatic guidance system, internal errors, errors out of the combination and recombination as well as errors of other modules shall be compensated in five degrees of freedom.Besides the error compensation a fast an ad hoc start-up procedure after the combination and recombination is required. Therefore a microcontroller shall be implemented into the feed unit. This microcontroller enables the control of the feed unit and the storage and exchange of data, required for the main control as well as the other modules. This data consists out of the characteristics of the modules as well as its errors. Besides a simulation model shall enable the determination and optimization of the controller as well as the compensation parameters of the active feed unit.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1476: Small Machine Tools for Small Work Pieces