Cutting Research For Desert Shrub Regenerating Harvesting With Circular Saw

This research studied the shrub cutting capability of disc saw for the purpose of better utilizing of the desert shrub resources and to promote the research of high efficiency shrub regenerating harvesting device.Firstly,field cutting test has been made with the first generation of pedestrian controlled circular saw shrub-cutter developed in the supporting project of "Eleventh Five-year Plan",by the Institute of Technology of Beijing Forestry University.Test research about splitting and burning in shrub cutting with circular saw has been done.And the result is,the highest rate of splitting is 3.85%,and no evident phenomenon of burning,with cemented carbide saw of diameter 305mm and the linear saw speed of 46.3～51.1m/s.Sprouting has not been evidently affected by the low rate of splitting.In this research,a simulating sawing system has been developed to make sawing simulation experiments on shrub specimens.It's designed to be powered by the electric motor.Feeding speed, circular saw,rotation sawing speed can be changed.And the motor torque,feeding speed and sawing speed can be measured to research about their influence on the cutting effect and the power consumed.Experiment of sawing simulation leads to the conclusion that,there are relative different critical cut-off speed for different feeding speed,different rotation speed and different circular saw.And it can be reference in the shrub harvesting device designing.Saw with high teeth number,big saw-set,small saw thickness,and front bevel angle of 20°has a smooth cutting and relatively low critical cut-off speed. Data of torque shows that,saw with a big bevel angle has a low power consumption.The 120T saw consumes a evidently high power when working at the speed higher than 3000rpm,because of severer friction.And other saws with fewer tooth consumes power which fluctuate with thespeed within a bound.The phenomenon of wood grain on the section is mainly determined by tartness of the teeth.The phenomenon of burning results from abrasion,stick ness of matter left by cutting,high linear speed of the tooth,small saw set,big diameter,and it can be avoided as much as possible by big saw set and low speed.Selection of cutting speed and saw type should base on the principles of smooth cutting,low power consumption,and low burning and splitting rate.