Hydro-mechanical Dampers for Testing high Cyclic Shock Loads in Preventive Health Protection

Abstract

Construction workers are exposed to harmful vibration emissions in the usage of power tools. For preventive health protection, the vibration emission is therefore regulated in the EN ISO 28927, as well as tested and optimized in the development of new power tools. The vibration emission of hammer drills and other impact driven power tools can be tested by using a steel ball energy absorber as a substitute workpiece, which reduces statistical variance and expenses in laboratory tests. The steel ball energy absorber, as the current used damper in EN ISO 28927, is not adjustable in its properties and has no variable influence to the power tools vibration emission. It is unknown, whether an adjustable damper could affect the power tools vibration emission. Therefore, a new adjustable hydro-mechanical damper for testing high cyclic shock loads was designed and tested in this study. The tests revealed that hammer drills vibration emissions can be influenced by an adjustable hydro-mechanical damper. In field tests, the used tool, tool wear or the machined workpiece influences the hammer drills vibration emissions. The new adjustable damper can improve the preventive health protection of workers, as these factors now can be taken into account in laboratory vibration testing.

Keywords: Preventive Health Protection, Vibration Emission, Testing, Power Tools, Impacts

DOI: 10.54941/ahfe1002793