Abstract
In the construction site, an electric hammer, a type of hand held vibrating tool, is used to crush concrete, asphalt and so on. The frequent user of this tool is at high risk for developing the hand-arm vibration syndrome because of excessive exposure to hand-arm vibrations. In order to prevent the disease, it is required to keep the vibration of the tool’s gripes as low as possible. The purpose of the present study is the development of a very low-vibrational electric hammer using self-synchronization phenomena in order to address the problem of the hand-arm vibration syndrome. In this study, a prototype electric hammer based on the impact model with two oscillators, which has been developed as synchronous vibration generating mechanism, is developed. The availability of the synchronous vibration generated in the prototype experimental apparatus is investigated based on sand compaction tests and numerical computations. In addition, the experiment for measuring the daily vibration exposure values and the impact forces was conducted to estimate the machine performance.
