Analiza značajki signala sila rezanja i jakosti struja pogonskih motora kod bušenja nehomogenih kamena

master's thesis

• Title (english): Cutting force and motor drve current analysis indriling of inhomogeous stone materials
• Author: Andreja Leonela Vojvodić
• Mentor: Toma Udiljak (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2015-12-01, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

Kamen je jedan od prirodnih materijala koji se svakodnevno koristio od najranijih početaka čovječanstva. Danas se koristi kao građevni materijal, a u većini drugih slučajeva ima dekorativnu i zaštitnu zadaću. Kao i kod drugih materijala, kombinacija mehaničkih, fizičkih, kemijskih svojstava uvjetuju mogućnost obrade i uporabe kamena.

Nemoguće je, zbog njegove heterogene strukture, odrediti točne vrijednosti parametara kojim bi proces obrade bio najučikovitiji. Tako npr. svrdlo pri bušenju nailazi na nekoliko različitih struktura kamena koje se međusobno razlikuju po svojstvima, posebno tvrdoći i bušivosti. Bušivost ukazuje na lako ili otežano prodiranje svrdla u materijal pa dobra procjena bušivosti rezultira dobrom procjenom tvrdoće obrađivanog materijala. U procesu obrade materijala odvajanjem čestica, rezni dio alata se troši. S obzirom na to, svrdlo je za vrijeme rada podvrgnuto mehaničkim, toplinskim i kemijskim opterećenjima koja uzrokuju promjenu geometrijskog oblika oštrice tj. njezinu istrošenost.

Što veći stupanj automatizacije procesa i predviđeni otpis alata ima svoje prednosti kao što su: smanjenje vremena potrebnog za zamjenu alata i izbjegavanja mogućih oštećenja stroja pri istrošenju alata, što je ujedno i pozitivno s ekonomske strane. Praćenjem stupnja istrošenosti, moguće je isplanirati proces s optimalnom potrošnjom energije, maksimalnim životnim vijekom alata i najvećom produktivnošću te učinkovitošću.

U radu je opisan utjecaj tvrdoće kamena na učinkovitost procesa bušenja i trošenje oštrice svrdla. Cilj pokusa je bio analizirati signale sila rezanja i jakosti struja pogonskih motora te procijeniti utjecaj tvrdoće na učinkovitost procesa. Uzorci kamena veće ili manje tvrdoće, podvrgnuti su ciklusima trošenja i mjerenja, kako bi se na kraju iz mjerenih vrijednosti tvrdoće procijenilo njihovo međudjelovanje.

Abstract (english)

Stone is one of the natural materials that are being used from the earliest beginnings of humanity. Today it is used as a building material, and in many cases stone has a decorative and protective role. As it is with other materials, a combination of mechanical, physical and chemical properties condition the ability of stone to process and use.

It is impossible, because of its heterogeneous structure, to determine the correct parameters which make the process of treatment stone most effective. For example, the drill when drilling encounters several stone structures that differ in properties, especially hardness and drillability. Drillability indicates easy or difficult penetration of the drill into the material and a good estimation of drillability results in a good estimation of the materials hardness. When processing materials, the cutting part of the tool is being spent. Given that, the drill during operation is subjected to mechanical, thermal and chemical loads that may change the geometry of the blades.

A higher degree of process automation and provided tool life has its advantages, suchas reducing the time required for tool change and to avoid possible machine damage caused by the tool wear. That is also positive from the economic point of wiew. By monitoring the degree of tool wear, it is possible to schedule a process with optimal power consumption, maximum tool life and highest productivity and efficiency.

This paper describes the influence of rock hardness on the efficiency of the drilling process and tool wear. The aim of the experiment was to analyze signals of cutting forces and motor drive current and evaluate the impact of hardness on the process effectiveness. Samples of stone with different values of hardness were subjected to wear and measurement cycles. In the end, the measured values of hardness were taken into account to evaluate their interaction.

• Keywords: kamen; tvrdoća; bušenje; trošenje
• Keywords (english): stone; hardness; drilling; tool wear
• Language: croatian
• URN:NBN: urn:nbn:hr:235:193094
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 15:21:03