Zasnova in izdelava dinamsko ustrezne velike CNC naprave

Košir, Tilen (author), Slavič, Janko (mentor)

Zaključna naloga opisuje zasnovo in izdelavo velike dinamsko ustrezne CNC naprave. Zasnova je opravljena z izbiranjem konstrukcijskih rešitev preko primerjalnih matrik, s preliminarnim statičnim izračunom, ter z modalno analizo lastnih frekvenc naprave po metodi končnih elementov. Namen modalne analize je dvig najnižjih lastnih frekvenc konstrukcije že v razvojni fazi konstruiranja, s čimer se izognemo kasnejšim večjim amplitudam pomikov, ki vplivajo na kakovost obdelave izdelkov. Zaradi predvidene obdelave različnih materialov z različnimi rezalnimi orodji in obdelovalnimi parametri je vzbujevalna sila neznana, zato je bilo napravo z dinamskega vidika pred izdelavo mogoče optimirati le z dvigom najnižjih lastnih frekvenc. V delu so opisane potrebne poenostavitve naprave za ustrezno mreženje konstrukcije s končnimi elementi. Celotna naprava je bila analizirana postopoma po delih, ki so ekvivalentni konstrukcijskim podsestavom X, Y in Z osi. S pomembnimi konstrukcijskimi dodatki je bil dodelan le podsestav X osi, katerega najnižji lastni frekvenci sta bili povečani za faktor 2.1 in 3.1. Nazadnje je bila izvedena še modalna analiza celotne CNC naprave. V nadaljevanju je opisan postopek detajlnega konstruiranja CNC naprave, izvedba krmiljenja s koračnimi motorji, ter sama izdelava in montaža naprave.

• Language: Slovenian
• Keywords: CNC, mehanska nihanja, modalna analiza, metoda končnih elementov, konstruiranje, izdelava
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Publisher: [T. Košir]
• Year: 2018
• PID: 20.500.12556/RUL-102563
• UDC: 621.9.01:531.3:658.5(043.2)
• COBISS.SI-ID: 16360731
• Publication date in RUL: 02.09.2018

KOŠIR, Tilen, 2018, Zasnova in izdelava dinamsko ustrezne velike CNC naprave [online]. Bachelor’s thesis. T. Košir. [Accessed 27 March 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=102563

Secondary language

• Language: English
• Title: Design and manufacturing of dynamically optimized large CNC machine

Abstract

The final thesis describes the design and manufacture of a dynamically optimized CNC machine. The design itself was developed through initial selection of design solutions using comparison matrices, preliminary static calculations, and modal analysis of natural frequencies of the CNC machine using the finite element method. The purpose of the modal analysis was to increase the critical natural frequencies. By doing that, the vibration amplitudes were decreased, which results in increased quality of machined parts. Since the induced vibration forces were not known due to a great variety of used tools and materials it was possible to optimize the machine only by increasing the lowest natural frequencies. To ensure proper meshing of the machine elements with finite elements some significant simplifications were made in order to ensure stable and fast convergence of the results. The analysis was conducted in stages. In each stage, X, Y, or Z axis subassembly was analyzed. The optimization process resulted in an increase of two X axis's natural frequencies by a factor of 2.1 and 3.1, respectively. Finally, the whole CNC machine was analyzed. The thesis further describes the machine's detailed design, motion control using stepper motors and manufacture.

• Keywords: CNC, mechanical vibrations, modal analysis, finite element method, machine design, manufacture