65905 - Mechanical Design and Drafting Applications (A-K)

Learning outcomes

The course aims at providing the students with the acquisition of basic skills for drawing all the main machine or plant components and understanding drawings already made by others. After a brief introduction to the geometrical bases, it treats, according to the italian standards, the rules and norms for the right representation of each component, by accounting for the function it plays into the device or assembly and for the cycle it experiences during its manufacturing.

Practical training is provided by letting the Student to utilize drafting standard tools, CAD tools and hand sketches. So the Student himself becomes skilful in correlating shape, function and productive processes in developing designs and modeling of the main components in industrial and mechanical machines and plants.

Course contents

Immediately below, main arguments of this course are reported.

Introduction. Conventional and unconventional tools for design and drafting. Use of standard line types and lettering. Utilization of formats and drawing scale.

Descriptive Geometry

Basic geometrical constructions.

Ortographic Mongian projections.

True shape representation of planar surfaces arbitrarily oriented with respect to orthographic projection planes. Sectional views of solids.

Intersections among solids.

Axonometric Pictorial parallel projections (hints).

Design process, standards, dimensioning and error restriction

Standards in technical design and drafting. First and third angle projections and sectional view standard methods. Dimensioning. Renard number series. Design process: assembly and single component drawings. Fuctional dimensioning. Production process influence on shape and dimensioning of mechanical components. Fabrication and control dimensioning.

Dimensional tolerancing. Transfer criteria from functional dimensioning to fabrication dimensioning. Measurement and restriction of component surface roughness.

Description and conventional representation of component assemblies devoted to specific tasks

Fasteners and connections. Threaded fasteners. Keys. Splines. Rivets. Welds. Adesive joints.

Guides and bearings. Journal bearings. Rolling contact bearings. Lubrication.

Mechanical Transmission. Shafts, clutches, couplings, belts and pulleys, roller chains, gears, cams, etc.

Readings/Bibliography

Direct references to theory lessons

The teaching material, provided by the teachers and referring directly to the lessons, can be found onvirtuale.unibo.it (ex iol.unibo.it).

In the same site some previous exams are included at disposal for the Students.

Reference books

Manfè, Pozza, Scarato, Disegno meccanico, vol. 1, 2, 3, ed. Principato, Milano.

Conti, Disegno tecnologico, vol. 1, 2, ed. Pitagora, Bologna.

Chirone, Tornincasa, Disegno Tecnico Industriale, ed. Il Capitello,

Sandro Barone, Alessandro Poli, Armando V. Razionale, Maurizio Berretta, Disegno tecnico industriale, CittàStudi Edizioni. Torino.

Sobrero, Corso di Disegno, solo vol. 1, ed. Pitagora, Bologna.

In-depth books

UNI M1, Norme per il disegno tecnico, vol. 1,2, pubblicato a cura dell'Ente Nazionale Italiano di Unificazione. piazza Armando Diaz 2, 20123 Milano.

Filippi, Disegno di Macchine, vol. 1, 2, ed. Hoepli, Milano.

Straneo, Consorti, Disegno di Costruzioni Meccaniche, vol. 1, 2, ed. Principato, Milano.

Teaching methods

Course configuration:
- theorethical room classes (6 CFU);
- practical laboratory activities (inside the other module, 'Applicazioni di Disegno Meccanico T', 6 CFU, which also belongs to the integrated course).

Attending classes is considered an important task for the Student, allowing him to understand how drawings must be performed. Teacher makes a lot of examples during theorethical lessons and takes with him many mechanical actual assemblies and components at disposal for the Students to be seen in classroom.

Laboratories are similarly important, because Teachers stay among Students explaining mistakes and giving them suggestions. For this reason, Teachers record frequency during Laboratories.

Lack of frequency to CAD laboratories implies for the Students a further individual CAD test.

Minimum number of hours to validate frequency depends on laboratory timetable pertaining to the specific academic year and it is specified, at the beginning of the course, by the Teacher who holds classes in the Laboratory module.

Assessment methods

A common exam is due for both this module (Disegno Meccanico T) and for that of Applicazioni di Disegno Meccanico T, which, both, constitute the integrated course (corso integrato, C.I.) of Disegno Meccanico e Automatico T (12 CFU).

Exam consists in a written test (compulsory for admission to the speech) and a speech (oral test).

a) Written test relative to the integrated course (Disegno Meccanico e Automatico T) consists of two parts:

a1) Written theoretical test, structured in some theorethical questions (whose exact number is suited to the difficulty of the peculiar arguments considered); it is obviously foreseen to perform drawings, which each Student can, at his choice, perform with instruments or in free hand (at this stage, the Student cannot read texts, notepads, tables or manuals); the form suitable to the development of this part of the written exam is provided by the teacher; Student has 1 hour and 30 minutes to perform this task;

a2) Graphic test, consisting in a 2D drawing ('virtual extraction' of a component from an assigned assembly); the component must be represented in accordance with the rules of the technical drawing (during this phase, the Student can read texts, notes, tables and manuals); of course it is prevented to the Student to make any connection to the computer network; each Student can, at his choice, perform his task with instruments or in free hand; Student has another 1 hour and 30 minutes to perform this second task; in this part of the written test, paper support (A4 or A3 formats, depending on the peculiar component) must be provided by the Student himself;

The whole written test lasts about 3 hours (1 hour and 30 minutes for each part and about 5 minutes of break between the two parts).

Results of the written test are published inside the current exam's Teams/Zoom Chat.

Admission to oral test is conditioned upon being successful in written test; Student must reach 18/30, which is the mean score obtained in the two parts of the written test (each of one is measured on a base of thirty).

Results of written test are provided before the next oral test, which is usually after about a week from the written test; timetable of the oral tests (exactly as that of the written tests) are at disposal of the Student in web site of Almaesami [https://almaesami.unibo.it/almaesami/welcome.htm] ; in any case, positive results to the written test are considered valid until the winter session of the next solar year (that is, before the beginning of the next cycle of lessons), so Students, which succed in written test, can afford oral test in every session until the winter session of the next solar year (included).

Lack of frequency to CAD laboratories implies for the Students a further individual CAD test.

Minimum number of hours to validate frequency depends on laboratory timetable pertaining to the specific academic year and it is specified, at the beginning of the course, by the Teacher who holds classes in the Laboratory module.

b) Oral test consists of some questions concerning the topics covered in the program, which, of course, involve the execution of drawings; the exact number of the questions depends on results of the written test and the value of the drawings performed in laboratory during the year, which the Student must take with him at the oral test (CAD drawings must be brought in a printed version). Global score depends on answers to the oral tests, value of the drawings performed in laboratory during the year, score obtained in the written test.

IMPORTANT NOTES

Student must book his exam in Almaesami [https://almaesami.unibo.it/almaesami/welcome.htm] web site.

Results of the written test can be found inside the current exam's Teams/Zoom Chat .

In summary, the Student must bring, during the written test, the necessary tools for drawing; can carry the texts, notes, drawings, etc., considered useful (exclusively for the second part of the written test) and must bring a pair of uncompiled paper sheet in both A3 and A4 formats (always for the second part of the written test). Obviously, no web or phone connections are allowed.

During the oral test, the student must bring the necessary tools for drawing and all the drawings carried out during the year (both those made freehand or with tools, and those made to the CAD, printed in the appropriate paper format).

Teaching tools

Slides, models for drawings to be performed during laboratory sessions and other information can be found on virtuale.unibo.it (former iol.unibo.it).

Links to further information

http://www.diem.ing.unibo.it/diem/cali/DMA_meccanica/DMAcalimecAttuale.html

Office hours

See the website of Leonardo Frizziero

See the website of Alessandro Ceruti