Dynamic Characteristic And Experimental Study Of Twin Boom Anchor Cable Drilling With Rubber Tyred Traction

Bolt-anchor support is a fast,safe and economical support method for coal mine roadways.It suspends the soft coal roof on the upper stable rock strata,so as to improve the overall strength and stability of the roadway roof.Bolter is supporting equipment for drilling roadway roof and lateral wall and installing bolt in underground coal mine.Its technology is relatively mature,which greatly improves the bolt support speed.However,the single boom bolter is always used in the construction of anchor cable drilling in domestic coal roadway at present.This drilling method of anchor hole requires close operation by workers,which has great restrictions and safety hazards.Some mining areas tried to use bolter implement anchor cable hole,but the effect was not satisfactory.Ordinary bolter is difficult to meet the requirements of drilling anchor.Thereby,it has become an urgent problem to study the safe and fast vehicle-mounted anchor support equipment and improve the speed of anchor cable hole-forming for the current underground roadway support.In this paper,the characteristics of CMM series bolter and rubber tyred trucks for crossheading were comprehensively considered.The drilling dynamic characteristics of anchor cable drilling such as torque,rotation speed and thrust were analyzed and calculated.The general technical scheme of hydraulic anchor cable drilling with rubber tyred was determined.The structure and the hydraulic system of anchor cable drilling were designed.Three-dimensional model of anchor cable drilling was established by Solid Works software.The underground working conditions of the anchor cable drilling are bad,the load is complex and changeable,and its working reliability is directly related to the performance of anchor cable drilling.Based on the theory of multi-rigid body dynamics and ADAMS software,this paper established the physical model and the topological relationship of anchor cable drilling.Considering the different working conditions of no-load state and virtual loading,the force distribution of main moving parts during the whole working cycle of anchor cable drilling were studied.The approximate real performance parameters of kinematics and dynamics of anchor cable drilling were obtained.The results show that the load state of the lowest position of platform is the worst case.The maximum force of left and right lifting cylinder can reach 1.29e5 N,and the force of front and rear connecting rods is also larger.It provides data support for analyzing the strength and durability of vehicle parts and the initial setting of hydraulic system.In the process of drilling coal rock with drill bit and drill rod,the anchor drill system will generate serious vibration problems,which will affect the service life of the drill rig.In this paper,the modal analysis theory was applied to analyze the natural frequency and modal shape of the constraint mode of single drill rig,the constraint mode of two drill rig hitting roof simultaneously,and the constraint mode of two drill rig hitting lateral wall and roof respectively.The influence of exciting vibration of drill rig caused by the interaction between drill bit and coal seam and rotating motion of drill motor on hole-forming accuracy of anchor drilling system working process were expounded.The results show that the resonance of anchor cable drilling can be avoided by controlling the rotation speed of drill box between 450 and 500 rpm.When studying the mechanical properties of anchor cable drilling,the finite element method is helpful to give effective direction prediction and evaluation.Based on the loads on the structural parts of the multi-body dynamic analysis of anchor cable drilling and the actual working conditions parameters and loads of the coal roadway obtained from the investigation,static strength of the key components of anchor cable drilling such as the drill mast,the drill stand,the chain device and the slide mechanism under complex working conditions were checked and analyzed by ANSYS Workbench software.So then,the structure can be modified and optimized to improve the reliability and adaptability of anchor cable drilling under various extreme conditions.In addition,the ultimate tensile load test of roller chain was carried out,and the quantitative conclusions with practical engineering application were obtained.In order to study the distribution state and variation law of system pressure,flow rate and rotational speed with load under actual working condition;this paper carried out external field no-load hydraulic system performance experiment and drilling pseudo-coal rock wall performance experiment respectively,and constructed the external field test system of anchor cable drilling.The experiment results show that the dynamic parameters of anchor cable drilling should be adjusted in time according to the different rock Protodyakonov coefficient when drilling hole.The order of magnitude of the test data is basically the same as the simulation curve.The research work and conclusions of this paper can provide theoretical basis and reference for the selection calculation,dynamic response characteristic analysis and design of the finalized structure of anchor cable drilling.