Alteração do campo visual em função do uso de cabinas em tratores agrícolas

Abstract

RESUMO:Com o objetivo de avaliar a alteração do campo visual de um trator, ocasionada pela instalação de uma cabina, foram determinadas as áreas de visibilidade nula em função da presença ou não da mesma, para cada campo visual. Os procedimentos adotados basearam-se na norma ISO 5721-1981 -Agricultural tractors -Operator's field of vision. A cabina aumentou em 34,42% a área de visibilidade nula. A relação área de projeção do trator/área total sombreada foi de 0,075 para o trator sem cabina, e 0,057 para o trator com cabina, indicando as melhores condições de visibilidade do primeiro em relação ao segundo. No que se refere aos campos visuais, a maior redução ocorreu no campo visual dos olhos e no obtido com o movimento da cabeça, em função dos suportes da cabina e da estrutura de proteção contra o capotamento. A cabina diminui o campo de visão do operador, e adequações no projeto da estrutura avaliada são necessárias para melhorar as condições de visibilidade. PALAVRAS-CHAVE:campo visual, tratores agrícolas, ergonomia. ALTERATION OF THE VISUAL FIELD IN FUNCTION OF THE USE OF CABINS IN AGRICULTURAL TRACTORSABSTRACT: Aiming to evaluate the alteration of the visual field of a tractor occasioned by the installation of a cabin were determined the null visibility areas due to the presence or not of this structure, for each visual field. The procedures adopted were based on ISO 5721-1981 -Agricultural tractors -Operator's field of vision. The cabin increased in 34,42% the area of null visibility. The relationship projection area of tractor/total shadowed area was 0,075 to the tractor without a cabin, and 0,057 for the tractor with cabin, indicating the best conditions of visibility of the first in relation to the second. With respect to the visual area, the largest reduction happened in the eyes visual field and in the obtained with the head movement in function of the cabin supports and the rollover protection structure. The cabin decreases the operator's area of vision, and adjustments in the project of the structure evaluated are necessary to improve the visibility conditions.

<b>Safety index for agricultural tractors

“…It is worth mentioning that the use of the cabin can reduce the viewing area by up to 35%, having thus a negative influence on the visual field, as compared to a tractor without cabin (Schlosser, Dallmeyer, Debiasi, Menegas, & Nietiedt, 2011). Thus, upon selecting a tractor, one should evaluate the visibility provided by the cabin as well as check the field of view of critical points that may offer higher accident risk, such as crushing or running over; in such cases, rear view mirrors will facilitate better viewing.…”

Visibility and Posture of Operators in Harvesters With Lateral and Front Coupling Cranes

“…It is important to mention that the design of machine booths must be done considering the maximum reduction of supports that hinder the operator's field of vision concerning the workplace (SCHLOSSER et al, 2011). It should also be noted that there are machines with different design features in terms of the hydraulic crane, which can be located at the side, front or above the booth.…”