Karakterizacija hrupnosti popolnoma avtomatskega kavnega aparata

Kolar, Klemen (author), Ocepek, Domen (mentor), Čepon, Gregor (comentor)

Magistrsko delo obravnava zmanjšanje hrupa popolnoma avtomatskega kavnega aparata, saj tiho obratovanje pomembno vpliva na uporabniško izkušnjo v gospodinjskem okolju. Namen dela je bil z inženirskim pristopom določiti glavne vire hrupa, analizirati poti prenosa vibracij in predlagati konstrukcijsko izboljšavo. V delu so bile najprej preučene teoretične osnove akustike, psihoakustike in merjenja zvočne moči. Eksperimentalni del je obsegal meritve zvočne moči po standardu ISO 3744 ter frekvenčno analizo signalov z metodama hitre Fourierjeve transformacije in analize s konstantno relativno pasovno širino. Na podlagi rezultatov je bila kot ključni sklop za nadaljnjo obravnavo izbrana vodna črpalka. Z dodatnimi meritvami in namenskim preizkuševališčem je bilo ugotovljeno, da pomemben del hrupa nastane zaradi mehanskega prenosa vibracij na ohišje aparata, predvsem prek membrane. Na osnovi teh ugotovitev je bila zasnovana konstrukcijska rešitev, usmerjena v zmanjšanje prenosa vibracij in posledično znižanje ravni hrupa aparata.

• Language: Slovenian
• Keywords: akustika, zvočna moč, popolnoma avtomatski kavni aparat, vibracije, hrup, črpalka, ISO 3744, konstrukcijska izboljšava
• Work type: Master's thesis/paper
• Organization: FS - Faculty of Mechanical Engineering
• Year: 2026
• PID: 20.500.12556/RUL-187984
• Publication date in RUL: 17.09.2026

Secondary language

• Language: English
• Title: Noise characterization of a fully automatic coffee machine

Abstract

This Master’s thesis addresses noise reduction on a fully automatic coffee machine, as quiet operation has an important influence on the user experience in a household environment. The aim of the thesis was to use an engineering approach to identify the main noise sources, analyse the vibration transmission paths, and propose a structural improvement. First, the theoretical background of acoustics, psychoacoustics, and sound power measurement was examined. The experimental part included sound power measurements according to the ISO 3744 standard and frequency analysis of the signals using fast Fourier transform and constant percentage bandwidth methods. Based on the results, the pump was selected as the key assembly for further analysis. Additional measurements and a dedicated test rig showed that a significant part of the noise is caused by mechanical transmission of vibrations to the machine housing, mainly through the membrane. Based on these findings, a structural solution was designed with the aim of reducing vibration transmission and consequently lowering the noise level of the machine.

• Keywords: acoustics, sound power, fully automatic coffee machine, vibrations, noise, pump, ISO 3744, structural improvement