Estimation of Impact Loads in a Hydraulic Breaker by Transfer Path Analysis

Changheon Song,Sang Seuk Kweon,Dae Ji Kim,Young Ky Kang,Kang Won Lee,Jintai Chung

doi:10.1155/2017/8564381

Changheon Song, Sang Seuk Kweon + Show 4 more

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https://doi.org/10.1155/2017/8564381

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Abstract

The aim of this study is to estimate the impact loads delivered to the housing of a hydraulic breaker quantitatively. Striking forces caused vibrations in the equipment housing, which were experimentally measured, and frequency response functions were also found through modal impact experiments. Transfer path analysis (TPA) method of the data quantified the impact loads delivered to the housing. TPA method can analyze the relationship between the vibration energy and the transfer path of an excitation source and so explore the way in which vibrations on each path contribute to the entire vibration profile. The impact loads of each part derived by TPA method were compared with the impact loads in the chisel derived from strain gauge measurements of the striking energy. This comparison validated the TPA approach. This study describes the basic concepts and components of TPA method and also reviews its applicability to mechanical equipment that experiences impact vibrations and impact loads.

Highlights

The main load of the hydraulic breaker was applied in the vertical direction, the impact loads were delivered to the housing due to pitch, roll, and yaw motions, which arose from vibrations of the main body caused by the striking action
This study reviewed the applicability of Transfer path analysis (TPA) to conditions where strain gauges and load cells are difficult to use
The applicability of TPA was confirmed based on estimating the impact loads through operational vibration and modal impact experiments, while accounting for the impact vibrations and impact loads of the mechanical equipment

Summary

Introduction

Excavators often use them to fracture the ground or bedrock to produce materials or aggregates or to demolish structures (Figure 1(a)) [1, 2]. A hydraulic breaker comprises a directional valve to control the direction of fluid flow, an accumulator to store the hydraulic energy and to supply the required flow during operation, a back head filled with nitrogen gas, pistons for delivering the striking energy to the chisel while performing a reciprocal motion, and a chisel that breaks the subject material directly. The hydraulic breaker is mounted on an excavator by a coupler (Figure 1(b)). The hydraulic breaker is a typical attachment commonly found at industrial and construction sites. Industrial and construction equipment requires high structural stability as well as intelligence, performance, and efficiency

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