Characteristics Study On A Vibration Reducing Seat Of Roadheader

Cantilever roadheader is widely used in tunnel,coal mine and other fields because of its advantages such as fast tunneling speed,high working efficiency,flexible operation,low cost and low labor intensity.In order to improve mining efficiency,roadheader is developing towards large-scale and intelligent direction.With the increase of the power of the roadheader,the vibration of the roadheader becomes more and more severe,and the working conditions of the roadheader?no load and cutting?are bad,which leads to the seat?usually using rigid seat?and the vibration of the body,which leads to poor driving comfort and easy fatigue.Increase the incidence of accidents.In order to solve this problem,this subject relies on Shanxi Jincheng science and technology plan project"Research and Development of Viscoelastic Damping and Buffering Device for Underground Roadheader in Coal Mine",aiming at the vibration comfort problem of roadheader seat,the following research is carried out:1.Comparing the vibration of the seat under different working conditions through the test of cutting artificial rock wall with the whole machine of roadheader.The results show that seat vibration has a great influence on driver's comfort.Among them,the driving comfort in the drilling and vertical conditions is the worst,which is“uncomfortable”,which reduces the driver's work efficiency and affects the driver's physical and mental health.2.Taking a vertical axis tunneling machine as the research object,based on its structural characteristics,actual working state and load transmission path,the basic assumptions are made,and the overall machine-seat damping model of the roadheader considering the cutting effect is constructed.The international standard ISO 2631 is chosen as the evaluation index of driving comfort.3.The main vibration sources of roadheader under different working conditions are determined by analyzing the working conditions of no-load and cut-off working conditions respectively.According to the national standard of road roughness GB7031-86 and the force condition of the cutting head,the road load and the cutting head load under the no-load condition and the cutting-off condition are obtained by MATLAB program simulation,and the spectrum analysis of the load is carried out.It is found that the load vibration energy is mainly concentrated between 0?25Hz and belongs to the low frequency and heavy load type.4.Under no-load condition,the influence of roadheader driving speed and road grade on driving comfort is analyzed.The analysis shows that the faster the speed,the worse the driving comfort;the higher the road level,the better the driving comfort.If the original rigid seat is used,the driving comfort is"relatively uncomfortable"when driving at high speed on Class F pavement;when driving at medium speed on Class G pavement,the driving comfort has reached"uncomfortable"and even reached"extremely uncomfortable"when driving at high speed.5.Based on the sensitive vibration frequency of the human body,the stiffness-damping value range of the system is determined.By calculating the driving comfort of different stiffness-damping parameters under various working conditions,it is concluded that the“no discomfort feeling”stiffness-damping value range under the cutting condition is:the stiffness coefficient k₅ is greater than 700 000 N/m,and The damping coefficient c₅ is greater than 34 000 N·s/m.Three sets of parameters were compared to analyze the vibration dissipation capability of the original rigid seat and the damper seat.The results show that under the no-load,sweep and drilling conditions,the damper seat has an acceleration root mean square compared to the original rigid seat.The reduction rate was 57.3%,74.5%and 74.9%,respectively,and the vibration transmission rate of the body to the seat was reduced by 40.0%,19.3%and 20.0%,respectively.Spectrum analysis shows that the first-order frequency of cutting force corresponds to the peak frequency of seat response,which is the main load component affecting seat comfort.The research results in this paper can provide theoretical basis and method for the development of high performance damping cushion seat for roadheader.