Ing Ind - Inf (Mag.)(ord. 270) - BV (483) MECHANICAL ENGINEERING - INGEGNERIA MECCANICA
097499 - FUNCTIONAL MECHANICAL DESIGN
The course provides the guidelines to functional mechanical design, focusing on main issues related to industrial automatic machines.
Main objectives of the teaching are:
- knowledge of basics on motion planning (how to design motion curves and how to optimze them according to different applications);
- knowledge of mechanisms (linkages and cams) to transform the motion;
- methodologies to analyse and synthesize plane and spatial mechanical devices;
- knowledge of industrial actuators and metodologies to size them according to the performance required;
- tools and methods for modeling a complex machine and to carry out its synthesis according to the requirements of the application;
- criteria to evaluate the correctness of a design choice
To bring students closer to the industrial world, some themes will be treated in collaboration with industrial companies leaders in the field.
Risultati di apprendimento attesi
** Knowledge and understanding
- knows the problems associated with the motion of a machine - knows the most common mechanisms used in the industrial field for the transformation of motion and the realization of complex movements - knows the most widespread industrial actuators and knows how to select them
** Ability to apply knowledge and understanding
- can design a motion law in accordance with the requirements of the application - can perform analysis and synthesis of the main mechanisms used in industry (cams and linkages) - can size an actuation system for moving a machine
** Autonomy of judgment
The student: - can independently evaluate the correctness of the design choices - can find alternative design solutions to a complex problem - can discuss and critically support his design choices
The functional design of a mechanical system. Introduction to motion law design, motion laws, mechanisms and actuation system classification.
Motion law. Motion law definition for the automation industry and properties of the acceleration diagram. Motion law adimensionalization and characteristic coefficient definition (velocity coefficient, acceleration coefficient, jerk coefficient, etc). Analysis of the principal requirements in motion law design (maximum acceleration limit, maximum velocity limit, ecc) with reference to the basic motion law. The improvement of motion law (basic motion law modified and polynomial motion law). Limits to the improvement attainable.
Cam Mechanisms . Description and analysis of cam mechanisms used in the industrial automation with particular reference to the manufacturing environment by means of a selection of industrial case studies. Pressure angle definition and undercutting analysis. Kinematic analysis of cam mechanisms through the inversion of motion and equivalent mechanisms. Cam profile determination for radial cam with translating roller follower, translating flat-faced follower and with oscillating roller follower. Methodologies to reduce the cam dimensions. Contact typologies between cam and follower: force close cam joint, form close cam joint and joint with “clearance ramps”. Reference to devices capable of modifying the movements of cam mechanisms.
Linkage Mechanisms: Definition and classification of linkage mechanisms based on the number of the links (four bars mechanisms, five bars mechanisms, etc.). Kinetostatic analysis and kinetostatic duality: transmission angle and generalized transmission ratio. Kinematic analysis of a linkage mechanism by means of vector closure equation and the Newton-Raphson method (coupler curve plotting for a four bar mechanism). Introduction to methods for direct and indirect kinematic synthesis of linkage mechanisms. Reference to kinematic optimisation. Quick return mechanisms and mechanisms with delays (superimposition of the dead centres method) and force multiplier mechanisms. Introduction to compliant mehanisms.
Actuators: Electrical motors used in automation: catalogue reading and typical problems in choosing electrical motors. Motor-reducer sizing methodology: accelerating factor and load factor, transmission ratio choosing and check of motor-reduce choice. Pneumatic actuators for industrial machines: devices and design of elementary circuits.
Modalità di valutazione
The exam is an oral test. Students will be asked to demonstrate their knowledge on main topics of the course and their ability in practically solve some design issues related to the analysis/synthesis of mechanical systems. During the exam students are supposed to motivate and to support their choices in a critical way.
P.L. Magnani, G. Ruggieri, MECCANISMI PER MACCHINE AUTOMATICHE, Editore: Utet, Anno edizione: 1986, ISBN: 9788802040240
Tipo Forma Didattica
Ore di attività svolte in aula
Ore di studio autonome
Laboratorio Di Progetto
Informazioni in lingua inglese a supporto dell'internazionalizzazione
Insegnamento erogato in lingua
Disponibilità di materiale didattico/slides in lingua inglese
Disponibilità di libri di testo/bibliografia in lingua inglese
Possibilità di sostenere l'esame in lingua inglese
Disponibilità di supporto didattico in lingua inglese