Production machine & machine tool
Categories
Tubular ultrasonic transducer: MUST with axial excitation versus conventional with radial excitation
19 June 2023
This paper presents comparison between two excitation solutions for tubular ultrasonic transducer. The axial excitation is widespread in conventional ultrasonic transducer. The radial excitation is proposed in order to have an uniform acoustic energy all along the tube. This excitation approach is also proposed to allow the modularity by adding several tubes.
Compact, Efficient and Controllable Moving Iron Actuation Chain for Industrial Application
7 January 2016
In the field of aeronautics, some parts of aircraft engines are tricky and costly to manufacture. In the low pressure turbine very thin pieces obtained by turning require a complex support. The R&D work performed here aims at improving the manufacturing process through the reduction of vibrations and active modification of the clamping conditions. For that purpose, Cedrat Technologies has designed a new innovative Moving Iron Controllable Actuator (MICA), which is embedded on the work-piece support. In the first part, the application goals and the main particularities of the developed MICA200M magnetic actuator are presented. To be easily driven in closed loop, the force is designed to be linear with the current and independent from the interface position. The MICA200M stroke is ±2.5mm and its force constant reaches 11.6N/A for a current range of ±15A
in steady state. The nominal force of 174N for only 1 dm3 size and 3.2kg facilitates the integration and allows acceleration up to 132G in transient operation thanks to reduced 0.25kg mobile mass. In the second part, results of complete experimental characterisation are detailed. Finally, a comparison analysis is done with COTS voice coil actuators and the article concludes with the benefits of the MICA200M.
Self-tuning semi-active tuned-mass damper for machine tool chatter suppression
19 June 2023
Tuned mass dampers are simple and efficient devices for suppression of machine tool chatter, which is one of the principal effects limiting productivity in many machining processes. However, their effectiveness depends on a proper tuning of the damper dynamics to the dynamics of the machine. This involves the dynamic characterisation of the machining process, in order to identify the critical resonance frequency, and the possibility of matching the resonance frequency of the damper to frequency. The difficulty of meeting these two requirements has been limiting the use of tuned mass dampers in industrial applications.
Investigations on a directly coupled piezoactuated tool feed system for micro electro discharge machine
19 June 2023
A directly coupled piezoactuated tool feed mechanism is proposed and a prototype micro-electrodischarge machine (micro-EDM) is developed. The piezoactuator is used to feed the tool and also to sense the tool displacement from a reference position. The hysteresis behavior of the piezoactuator is also incorporated through an electromechanical model for estimating the actual tool displacement. Simulation results for piezoactuator displacement are compared with the experiment and a maximum error of 15% was observed. Further, in order to control the tool feed rate during machining, a tool feed controller based on the gap voltage feedback is developed.
Servo piezo tool SPT400MML for fast and precise machining of free forms
19 June 2023
Recent requirements for accuracy and resolution demand higher quality in the machining of precision parts in many industries—such as optics, automotive and aerospace—by free form machining. The required operations are possible by using expensive manufacturing equipment in parallel with several processes such as grinding and polishing. By using a new fast tool servo, the so-called servo piezo tool SPT400MML, driven by a piezoelectric actuator for the precision diamond turning of non-symmetrical surfaces, components can be machined with a fast motion control of the tool (diamond or carbide).
