magistrsko delo - (magistrski študij - 2. stopnja)
Matej Šilc (Author), Igor Potočnik (Mentor), Anton Poje (Co-mentor)

Abstract

Namen magistrske naloge je bil razjasniti vpliv, ki ga imajo lastnosti vlak na obremenitev voznika zgibnega traktorja s tresenjem celotnega telesa. Meritve jakosti tresenja celotnega telesa so bile opravljene na sedežu in pod sedežem zgibnega traktorja Ecotrac 120V in sicer na 50 metrskih odsekih gozdne ceste in vlake v mirovanju in med premikanjem zgibnika. Pri prazni vožnji so bile izvedene meritve pri 1000, 1500 in 2000 obratih motorja zgibnika, pri polni pa pri 1500 obratih motorja. Indeks neravnosti (HRI) se je pridobil s pomočjo terestričnega laserskega skeniranja obeh tras. Ugotovili smo, da obremenitve s tresenjem celotnega telesa naraščajo z naraščanjem grobosti podlage. Najvišje obremenitve s tresenjem (do 1,6 m/s2) smo izmerili v aksialni (Y) smeri. V splošnem je razvidno, da jakosti tresenja naraščajo v vseh smereh (X, Y, Z) in njihovi vektorski velikosti (RMS VTV). Meritve so pokazale, da so po kazalniku RMS VTV, jakosti tresenja pri prazni vožnji za od 7,4 do 28,1-krat višje kot pri mirovanju. Ugotovili smo tudi, da so glede na kazalnik RMS VTV jakosti tresenja celotnega telesa pri prazni vožnji po vlaki za od 1,5 do 2,4-krat višje kot pri prazni vožnji po cesti. Sedež zmanjšuje obremenitve v mirovanju, pri višjih hitrostih zgibnika pri prazni ter predvsem pri polni vožnji po vlaki, povečuje pa pri vožnji po cesti oz. podlagi z nizko neravnostjo ter nizkih hitrostih pri prazni vožnji. Ob predpostavki, da se jakosti tresenja po posameznih faktorjih seštevajo, smo ocenili prispevke posameznih faktorjev h končni jakosti tresenja. Tako lahko zaključimo, da je hitrost vožnje najpomembnejši dejavnik, ki vpliva na jakost tresenja celega telesa, sledi pa neravnost podlage. Ukrepi za zmanjšanje obremenjenosti s tresenjem so: prilagoditev hitrost vožnje grobosti podlage, delovanje gozdarskega stroja pod čim nižjim tlakom pnevmatik, kot to še dovoljujejo razmere za varno delo, vzdrževanje planuma vlak, izbor pravilno vzmetenega in pritrjenega sedeža, ter organizacijski ukrepi, ki zmanjšujejo čas izpostavljenosti delavca obremenitvam s tresenjem.

Keywords

Ecotrac 120V;lastnosti vlak;traktorji;vozniki;tresenje celega telesa;grobost podlage;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [M. Šilc]
UDC: 630*36:630*30(043.2)=163.6
COBISS: 4110502 Link will open in a new window
Views: 403
Downloads: 129
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Other data

Secondary language: English
Secondary title: Impact of skid trail characteristics on exposure of a skidder driver by whole-body vibration
Secondary abstract: The purpose of master thesis was to investigate the impact of characteristics of skid trails on exposure of a skidder driver by whole-body vibration. Measurements of the intensity of whole-body vibration were carried out on and under the seat of an Ecotrac 120V skidder on 50-meter sections of a forest road and a skid trail at rest and during the movement of the skidder. In case of driving empty, the measurements were performed at 1000, 1500 and 2000 rpm of the skidder motor and, in case of driving full, at 1500 rpm. Roughness index (HRI) was obtained by means of terrestrial laser scanning of both routes. We established that the exposure of whole-body vibration increases with increasing roughness of the basis. We measured the highest exposure to vibration (up to 1.6 m/s2) in axial direction. In general, it is evident that the intensity of vibration increases in all directions (X, Y, Z) and their vector magnitude (RMS VTV). Measurements showed that according to the RMS VTV indicator the vibration intensity when driving empty is 7.4 to 28.1 times higher than at rest. We also found out that the intensity of whole-body vibration when driving empty on a skid trail is 1.5 to 2.4 times higher than when driving empty on road, according to the RMS VTV indicator. Seat reduces the exposure at standstill, at higher skidder speeds when driving empty and mostly when driving full on a skid trail and increases them when driving on a road or a basis with low roughness and when driving empty at low speeds. Assuming that the intensities of vibration add up by individual factors, we evaluated the contribution of each factor to the final intensity of vibration. Thus, we can conclude that speed is the most important factor which affects the intensity of whole-body vibration, followed by the roughness of the basis. Measures for reducing the exposure to vibration are: adjustment of the driving speed to the roughness of the basis, operation of a forestry machine with tire pressure as low as conditions for safe work allow, maintenance of the skid trail foundation, selecting a properly cushioned and fixed seat and organizational measures that reduce the exposure time of a worker to the exposure to vibration.
Secondary keywords: Ecotrac 120V;skid trail characteristics;tractors;drivers;whole-body vibration;roughness of basis;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za gozdarstvo in obnovljive gozdne vire
Pages: IX f., 70 f.
ID: 11564936