TBM Integrated Cutter System And Its Actuator Design

It is estimated that by 2022,the total length of tunnels such as subways,highways and railways in China will exceed 10,000 kilometers,and tunnel boring machines is important construction equipment.The roadheader breaks the rock through the cutter on the cutterhead.During the construction process,The problem of personnel safety and restricting the efficiency of tunneling brought by frequent inspection and replacement of cutter.It is imperative to realize the efficient and safe operation mode of the “machine substitution” of the cutter change operation.Traditional cutter fasteners are numerous and discrete,and their shapes and sizes are different.Designing an automatic cutter change actuator for this structure and the cutter change actuator will be very cumbersome,and the actuator design will be very difficult.Before designing a cutter changer,it is essential to design an integrated cutter system for machine operation and its cutter changer.In view of the above problems,the main work of the research carried out in this paper is as follows:(1)The characteristics of the four traditional cutter structures applied on the market are analyzed.According to the idea of integrating cutter,locking block and bolt,three integrated structure system solutions with different structures are proposed.Seven performance indicators for integrated cutter evaluation for machine cutter change operation: static stiffness,static strength,weight,three-dimensional size,extraction size,disassembly action and pre-tightening force.Comparing and analyzing the various indicators of the three integrated structural schemes,the traditional cutter scheme and the BOUYGUES company's scheme,an optimal cutter change scheme is obtained.Through the 3D printing technology processing scale model,the structure is re-optimized for the physical model,and the scaled sample of the final solution is processed.(2)On the basis of designing a new type of cutter seat which is convenient for machine operation,the change of pre-tightening force of the structure under the condition of vibration is studied experimentally,and the vibration tightening experiment for the structure of cutter base is designed.After 20 hours of vibration,when the vibration acceleration is 3g,the percentage of the pre-tightening force of the conventional cutter is 1.76 times that of the new type of cutter;when the vibration acceleration is 10 g,the percentage of the residual value of the conventional cutter residual preload is 2.69 times that of the new type of tool.That is to say,the new cutter seat is superior to the conventional tool holder in resisting the pre-tightening force over a long period of time.(3)For the design of the integrated cutter system structure,combined with the TBM's changeable cutter space limitation,the end-operating actuator of the cutter change robot was designed.Design actuator structures include: gripping,bolt tightening,telescoping,and rotational freedom.Static check for the design structure and key components through finite element software The maximum deformation of the actuator under the working condition is 1.2738 mm,and the maximum stress is 103.97 MPa.Based on the Lagrangian method,the dynamic equation of the actuator is established.The ode45 method is used to solve the differential equation of motion,and compared with the motion response of Adams simulation software.The maximum relative error of the derived dynamic equation solution and the Adams virtual simulation result is 0.11 %.(4)A scale bench for verifying the function of the TBM cutter changer and actuator was designed.Taking a certain type of TBM of the North Heavy Industry as the scale object,the main space limitation condition during the cutter change is retained,and the cutter of the entire cutter change range is simulated by a single cutter box with adjustable polar angle,polar diameter and pitch angle.The test stand structure includes a polar angle adjustment mechanism,a pole diameter adjustment mechanism,and a pitch angle adjustment mechanism.After the prototype of the test bench was built,the main design parameters were measured and verified.Except for the overall design size,the main parameter adjustment indicators were within the design range.