Definition, place and role of fixtures in mechanical engineering. Structure of the technological system. Role of fixtures in the technological system. Main components of a fixture. Basic requirements and classification of fixtures.
Mounting workpieces in fixtures. Definition of mounting. Selection of supporting surfaces. Conventional representations of positioning diagrams. Establishment of locating datums. Positioning of rectangular and cylindrical workpieces.
Types of locating elements used in fixtures. Standardised locating elements.
Types of locating elements used in fixtures. Non-standardised locating elements. Influence of workpiece mounting on machining accuracy.
Study of positioning errors. Influence of dimensional tolerances, angular deviations and functional clearances between locating elements and workpieces on machining accuracy. Clamping of workpieces in fixtures.
Sources of clamping force. Determination of clamping forces in mechanical fixtures. Wedge fixtures and wedge-and-plunger mechanisms.
Screw-and-nut clamping mechanisms and commercially available screw fixtures. Cam clamping mechanisms and commercially available cam fixtures.
Lever clamping mechanisms: single-arm and articulated lever mechanisms. Commercially available lever mechanisms. Elastic bush clamping mechanisms.
Determination of clamping forces for pneumatic, hydraulic, vacuum, magnetic and electromagnetic actuation. Pneumatic actuation of fixtures: operating principles, actuation diagrams and actuator components.
Commercially available pneumatic clamping mechanisms. Vacuum-operated fixtures: operating principles, actuation diagrams and commercially available solutions. Hydraulic actuation of fixtures.
Hydraulic actuation: operating principles, hydraulic circuit diagrams, components and commercially available clamping mechanisms. Magnetic and electromagnetic actuation of fixtures.
Construction and operation of centring mechanisms. Requirements for centring mechanisms. Types of self-centring fixtures. Fixtures for machining rotational workpieces.
Construction and operation of fixtures for clamping prismatic workpieces. Modular fixtures.
Special methods for clamping complex workpieces. Tool holders for machine tools. Fixture design methodology.
II. Laboratory Works
Supporting and clamping workpieces in jigs.
Determination of clamping errors when machining prismatic workpieces in fixtures.
Determination of locating errors when machining prismatic workpieces clamped on two perpendicular surfaces.
Determination of positioning errors when machining workpieces mounted on mandrels.
Determination of positioning errors when machining workpieces mounted on two pins.
Determination of centring errors when machining workpieces mounted on prisms.
Determination of clamping errors when positioning workpieces on support pins.
Study of the influence of handle dimensions in threaded clamping devices on the deformation of low-stiffness workpieces.
Alignment of fixtures and workpieces in the manufacturing system and establishment of the workpiece origin for machining.
Study of the positioning accuracy of rotational workpieces in fixtures.
Study of the deformation of low-stiffness plate-type components when clamped in fixtures.
Design and operation of indexing fixtures.
Study of specialised pneumatically operated fixtures.
Operation of grippers.
III. Project
Project assignment: design of a special fixture for positioning and securing reference point PD no. ___.
Conceptual design of three alternative solutions.
Constructional design. Functional analysis and verification of compliance with positioning and clamping requirements.
Structural design. Analysis of the manufacturability of component parts.
Preparation of fixture assembly and operating instructions. Evaluation of the calculation report.
Detailed design and preparation of the project's technical documentation.
Assessment of project completeness.
ECTS credits
6
Teaching Language
English
Exam Language
English
Support Materials Language
English
Basic Learning Outcomes
Course categorized
Managing Entity (faculty)
Faculty of Industrial Engineering, Robotics and Production Management (UTCN)
