| Hydraulic Demolition Robot has the characteristics of remoted control operation and compact structure,which make it have incomparable advantages in dust,noise and dangerous situations compared with ordinary excavator or manual.With the acceleration of urban demolition and reconstruction and the improvement of environmental protection requirements,it has good development prospects and has become one of the hot spots in the development of domestic concrete demolition industry.The working arm device is a multi-body structure consisting of a hydraulic cylinder,a segment arm and a dismantling tool head.It is one of the key components of the dismantling robot.Based on the basic theory of mechanical dynamics,the design and analysis of the dismantling robot working arm device are carried out in this paper.Firstly,after investigation,comparison and analysis,it is pointed out that the fundamental difference between hydraulic Demolition Robot and traditional excavation machine lies in the different space position of the object of action,and the former also needs to solve the problem that the latter cannot work in the indoor or narrow space.Combining with the space characteristics of modern architecture,the space design idea of demolition robot's working arm device is put forward.To meet the overall needs,the overall three-dimensional spatial layout design was completed,and a three-dimensional virtual prototype was developed.According to the operation characteristics,it is proposed that the degree of freedom of the hydraulic disassembly robot arm device is more than that of the traditional disassembly machine.Based on this idea,the space geometric model of the hydraulic disassembly robot arm is established after simplifying the structure.The dynamic differential equation is established by the equivalent finite element method of lumped mass and inertia.The Runge-Kutta numerical solution method is used to solve the disassembly robot arm in normal condition.Force analysis under working conditions,combined with the characteristics of traditional hydraulic hammer working,the impact load of the removal robot arm is solved,which lays the foundation for the following work.Traditional piston crusher hammer produces enormous noise and problems of bushing wear,cavitation,oil leakage and red oil when it is subjected to continuous vibration.Aiming at these problems,the design scheme of a new type of high frequency vibration crusher hammer is put forward.This type of crusher hammer mainly consists of four parts: vibration absorption structure,driving mechanism,eccentric mechanism and dismantling mechanism,among which eccentric block,hydraulic motor and teeth are included.The key components such as wheels and bearings are designed,selected and checked.When the designed hydraulic Demolition Robot is equipped with the traditional hydraulic hammer,its arm mainly bears the impact load of fixed frequency.When the natural frequency of the arm itself is the same or similar to the frequency of the external impact load,the structure is liable to produce resonance,which results in excessive displacement deformation in the two areas of the cylinder mounting seat and the supporting arm of the hammer and the articulated part of the main arm.The vibration frequency of the designed high-frequency vibration crusher is 35-40 HZ.Therefore,the vibration characteristics of the crusher at 35 and 40 HZ are analyzed.It is concluded that there is a risk of serious collision between X and Z directions.Finally,according to the results of simulation analysis,the dismantling robot arm is first optimized by topology.After the failure of topology optimization,the part with excessive deformation and displacement of the arm is optimized by adding reinforcement plate.The structure and size of the high frequency vibration hammer are redesigned,and the dynamic characteristics of the two parts are found after the simulation.All of them have been significantly improved,which provides a reference for the mechanical design of this type. |
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