Abstract
The purpose of the present research is to develop a hand-held vibrating tool using self-synchronization phenomena in order to address the problem of the hand-arm vibration syndrome. We focus on the development of a vibration mechanism for a tamping rammer used to compact cohesive soils and asphalt. The prototype with a generation mechanism of synchronous vibration suitable for a tamping rammer has been developed based on the mechanism of the impact model with four oscillators developed in the previous report. This model consists of an upper block and two lower blocks coupled by coil-springs, and two rotor-type oscillators are mounted on each of the lower blocks. In the present study, the availability of the synchronous vibration generated in the prototype is investigated based on sand compaction tests and a numerical computation using the shooting method. The results confirm that synchronous vibration which is able to achieve a good balance between vibration control and the excitation can be generated.