Fault Diagnosis Research on Impact System of Hydraulic Rock Drill Based on Internal Mechanism Testing Method

Yelin Li,Xiao Wu,Youxin Luo

doi:10.1155/2018/4928438

Abstract

In the production and manufacturing process of hydraulic rock drill, there are small impact energy and low impact frequency, and a fault diagnosis method based on the internal mechanism testing and testing of the hydraulic rock drill is proposed. This method is used to test the change law of hydraulic oil in the rock drill, by retaining the test holes on the cylinder body and other important components of the hydraulic rock drill. At the same time, the mathematical method is used to deal with the test curve, and the influence of pressure pulsation characteristics of the front and rear chambers of the impact piston and the left and right valve chambers of the reversing valve on the impact performance of the rock drill is analyzed. Based on Newton’s law, the model of the impact piston and reversing valve is established. According to the velocity and other parameters of the impact piston, the size of the impact piston switch point is calculated. The coupling between the movement of the impact piston and the movement of the reversing valve is analyzed according to the model established. Comparing the results of the experimental data, the correctness of the fault diagnosis analysis method and model is verified. The effect of the fault rock drill and the improved model is compared, and the theoretical basis is provided for the fault diagnosis of the rock drill and the design of a new type of rock drill.

Highlights

Hydraulic rock drill is widely used in mining, tunneling, and building industries
Taking the hydraulic drill with no constant-pressurized chamber as an example, through the test and analysis of the coupling between the internal impact piston and the reversing valve of the rock drill, a testing method which can be applied to the manufacturing process of the rock drill can be studied, which can provide a theoretical basis for the fault diagnosis of the rock drill and the design of a new type of rock drill
Impact Principle of Hydraulic Rock Drill e drilling principle of the hydraulic rock drill is shown in Figure 1. e impact piston, the damping piston, and the shank are inside the hydraulic rock drill. e shank is

Summary

Introduction

Hydraulic rock drill is widely used in mining, tunneling, and building industries. E stress wave method is used to test the transmission effect of stress wave in the drill rod, and the impact energy of the hydraulic rock drill can be calculated by the stress wave test. E impact piston, the damping piston, and the shank are inside the hydraulic rock drill. E impact mechanism of the hydraulic rock drill is mainly composed of cylinder body, impact piston, reversing valve, and high pressure accumulator [7]. E coupling between the impact piston and the reversing valve is the key factor of the working performance of the hydraulic rock drill. E impact piston movement of the hydraulic rock drill is divided into three processes: return, stroke, and impact, and the reversing valve makes a switch of direction in time with the impact piston in the three movement processes [8]. State 8: e impact piston returns acceleration; the reversing valve stops. is state is the same as state 1 and enters the second movement cycle

Mechanism Test Design

Experimental Analysis

Fault Diagnosis Analysis

Conclusions

Impact point