TBM Cutting Tool Wear Detection System Based On Displacement Sensor

The hob is the main tool for TBM shield machine to undertake rock breaking tasks during underground tunneling.Hob wear is unavoidable in the construction process.When the hob is seriously worn,it is necessary to change the hob in time to ensure the normal operation of the TBM.Therefore,how to accurately detect the wear condition of hob in working condition and how to help construction personnel to grasp the right time to change the hob is particularly important.The research of hob wear measurement system in TBM operation process has become a major research direction of TBM tunneling technology.In this paper,a measuring system based on displacement sensor is designed to detect the wear of the hob in the driving process.Through the analysis of the testing data,it provides a powerful reference for the construction personnel to change the knife,so as to improve the efficiency and safety of the TBM work.After analyzing the bad environment of the system,the basic structure of the TBM hob,the working principle and the possible form of wear failure in the process of rock breaking,the inductive proximity sensor is selected as the detecting device of the detection system.Beceuse the detection distance is constant when the sensor detects the same metal object,the detection system controls the sensor probe head to close or far away from the hob ring through the linear displacement platform driven by the MCU.In its motion,the sensor output switch signal is captured and the relative displacement of the linear displacement platform is recorded at this time.Through theoretical deduction,the amount of hob wear is transformed into the relative displacement of the displacement platform in the detection system.By analyzing the displacement of the corresponding displacement platform,we indirectly grasp the wear condition of the hob,so as to realize the detection of the wear quantity of the hob.In this paper,the hardware and software modules of the detection system are introduced in detail,and the hysteresis characteristics of the inductive proximity switch sensor are analyzed,and a variety of hob wear detection strategy is proposed.Finally,through experimental analysis,the validity of the detection principle is verified,and the conclusion that the detection accuracy of the detection system meets the actual use requirements is obtained.