Investigating operator vibration exposure time of 13 hp power tiller fuelled by diesel and biodiesel blends

Abstract

One of the most useful agricultural machinery is power tiller; this kind of tractor is widely used in small fields. The operators of this kind of machinery are exposed to high level of vibration. Long time working with these machinery causes dynamic disorders, damaging different parts of the body, digestion disorders and vascular diseases. In this research, vibration acceleration of 13hppower tiller was collected in 5 levels of engine speed and 6 kinds of consumed fuel blends investigating the power tiller vibration exposure time. The data were analyzed by factorial tests with completely random design. The results showed that reciprocal effect of fuel and engine speed are prominent in 1% level. The working conditions of the power tiller operator fall into the highest class of risk according to ISO 5349-2 (2001) and in less than 4 years White Finger Syndrome may have induced in 10% of operators. Results of experiments revealed that the exposure time decreases with increase in engine speed especially in 1,800 and 2,200 rpm. The reason is the vibration intensification that happened in handle of power tiller in 1,800 rpm engine speed so it reduced the exposure time severely. The latency period for the appearance of vibration-induced White Finger Syndrom in biodiesel 10%, 15% and 20%, respectively, so using diesel fuel can be replaced by these three kinds of fuel in power tillers.

Keywords

• white finger
• vibration acceleration
• highest class of risk
• working conditions