Production machine & machine tool
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Actuators in adaptronics: piezoelectric actuators
19 June 2023
Piezoelectric actuators have increased their number of application in adaptronics over the past decade [1]. They can be used with several drive and control strategies and they are more adapted to mechatronics applications requiring bandwidth, accuracy and/or lightweightness. The purpose of this paper is to recall the different existing piezo actuators, the different drive and control techniques and finally review several applications in machine tools, optics.
Amplified Piezo Actuator APA® with viscoelastic material for machine tool semi active damping system
8 January 2016
Modern machine tools must achieve a high precision for a better surface texture and higher flexibility for wide range of machining requirements. To fulfill these requirements, a semi-active damping system for a new generation of machine tools is proposed. The new concept is partially based on the Amplified Piezo Actuators APA® from CEDRAT Technologies. With these actuators, the dynamic behavior (stiffness and damping) of structural body components of machine tools can be controlled and adjusted to the optimum parameters. To reduce the transfer of vibrations through the active elements, a viscoelastic material was used. This article presents test results performed on the APA® with viscoelastic material. A significant reduction of the vibrational amplitude at resonance frequency was observed with additional material. The optimized quantity of viscoelastic
material reduces the full stroke of the actuator only by 10 percent. At the same time, the viscoelastic material has reduced the amplitude at resonance frequency by more than double. The designed actuator obtains a blocking force of 8.5kN. Results obtained from the tests performed on the machine tool showed significant surface texture improvement with use of the amplified piezoelectric actuator.
Amplified piezo actuators enhancement for active vibration control
7 June 2018
Amplified Piezo Actuators (APA®) from CEDRAT TECHNOLOGIES are known to be compact and especially performing in dynamic applications. The recent evolutions realized on the APA® and drive electronics allow them to address active damping better than magnetic proof mass in terms of the Force to Volume ratio above some 10Hz. The dynamic capability of the APA® has been improved thanks to preload method enhancement. Research has successfully shown the possibility to achieve a high dynamic force level similar to the static blocked force of the piezo actuator. This technical progress coupled with an amplified motion makes possible the generation of high mechanical proof mass load at relatively low frequency. It produces a force higher than 100N in a volume of Ø40x75mm within a range of [100-300Hz]. This paper presents relevant uses of APA® for active damping in machining applications. Several machining case studies are reported integrating Amplified Piezo
Actuators within the spindle head, inside the cutting tool or beside the workpiece clamp.
Development of the plain bearing and flexure bearing MICA300CM actuator
7 May 2018
The MICATM linear actuator family (Moving Iron Controllable Actuator) is being continuously improved at CEDRAT TECHNOLOGIES (CTEC) for applications needing high controllable stroke, force, and power. The MICA300CM is a new actuator model, having improved configuration based on cylindrical shape. A first version based on plain bearing offers up to 12mm stroke and 300N continuous force with a weigh of only 3kg. A second version is based on new frictionless flexure bearings. The former one is especially designed to achieve zero maintenance over several years of operation, with high efficiency, infinite resolution, and high controllability performance. This version of the MICA300CM has been derived to offer a proof mass configuration, for vibrationcancellation applications on machining processes. A latest version is also currently under design, and prototyping, specifically for reciprocating power piston applications, such as compressors, pressure wave generators, and pumps. Its high efficiency, ultra-long lifetime capability, and compactness, makes it perfectly suitable for embedded thermal machines based on Stirling, Joules Thomson, and Rankin Thermodynamic cycles. This paper presents this 4 design concepts, their test results and perspective for applications.
Tool adaptor for active vibration control in turning operations
19 June 2023
A tool adaptor with built-in active vibration damping device to dynamically stabilize the turning process is presented in this paper. It can be used in standard CNC-lathes and allows the usage of off-the-shelf tool heads. The vibration compensation system is based on a multilayer piezoactuator that is in collocation with a piezoelectric force sensor. An analogue controller based on the integral force feedback method is used for active damping.
High power force oscillator and drive electronics
19 June 2023
This paper presents the development of one amount the largest piezo actuator ever designed based on low voltage PZT. This actuator is able to provide more than 20kN of force in dynamic operation (60kN in static operation). The purpose of low frequency vibration generation is to improve the quality of parts production in the field of manufacturing and machining process.
