Design Of Caragana Korshinskii Stubble Cutter And Its Cutting Test Stand

Caragana korshinskii(C.K.)is a kind of xerophytic shrub in arid and desert areas,which is mainly used for soil and water conservation,wind prevention and sand fixation.Due to the growth characteristics of C.K.,it is necessary to carry out the flat stubble operation once every 3-5 years.The stubble after the flat stubble is required to be free of stubble,burns and tears,so as to achieve the purpose of rejuvenating C.K.in the next year,otherwise it will cause its growth retardation or even death.However,in the actual operation of C.K.flat stubble,the unreasonable selection of mechanical parameters of flat stubble will cause problems such as uneven stubble and large power consumption.Therefore,this paper focuses on the way of circular saw cutting flat stubble,starts with the main influencing factors of the quality of C.K.flat stubble,and uses the methods of finite element simulation analysis and practical test to reduce the cutting power consumption and improve the stubble quality.The main contents of this paper are as follows:(1)Study on biomechanical properties of C.K..Firstly,the moisture content and density of C.K.grown for 3～5 years were measured.The results showed that the moisture content of C.K.in October is 31.35%,the air dry density is 0.735 g/cm3,the total dry density is 0.595 g/cm3,and the basic density is 0.565 g/cm3;Secondly,the tensile and compression tests of C.K.were carried out.When the moisture content of C.K.was 20.8%,the axial tensile strength of wood was 135.96 MPa and that of cortex was 19.24 MPa;The axial compressive strength is 19.24 MPa,the radial compressive strength is 30 MPa,and the chord compressive strength is 20.67 MPa;(2)Development of C.K.cutting test-bed.According to the overall design requirements and design principles of the cutting test-bed,two design schemes are completed,and the final design scheme is determined through comparison and selection,and the prototype is processed and manufactured.The cutting test-bed integrates two flat stubble cutting modes,namely,disc sawing and reciprocating cutting.It is mainly composed of cutting device,feeding device,clamping device and control and data acquisition system.The cutting motor speed is 0～2890 r/min,the feeding speed is 0～0.89 m/s,and the sawing angle is continuously adjustable within 0～45°;(3)Finite element simulation of saw blade parameters.Firstly,according to the simplification principle of cutting system model,the cutting system model is established in ABAQUS finite element simulation software,and then the rationality of the model is verified.The results show that the model is reliable.Finally,the main parameters of the circular saw blade are selected,and the simulation model is used to explore the influence of the saw blade parameters on the cutting power and section quality.The results show that when the outer diameter of the saw blade is 355 mm and the inner diameter is 30 mm,the cutting effect will be better if the alternating tooth circular saw blade with front angle of 20°,back angle of 15°,tooth thickness of 3 mm and 100T is selected;(4)Sawing test research.Using the independently developed C.K.cutting test-bed,the single factor test is carried out first,and then according to the single factor test results,the sawing speed of 45 m/s,the feed speed of 80 mm/s and the sawing angle of 5° are selected as the zero horizontal points.The box Behnken test theory method is used to design the three factor three level orthogonal regression test.The regression model is established by using design expert software and the variance and response surface analysis are carried out The results show that the model is reliable.Finally,through multi-objective optimization analysis and experimental verification,the optimal combination of working parameters is obtained as follows:sawing speed v1=45.07 m/s,feed speed v2=80.73 mm/s,sawing angle,at this time,the cutting power is 23.53 W,and the section quality is 7.34%.The C.K.cutting test-bed designed in this paper can solve the problems of difficult data collection and high cost in field test.The test results can provide theoretical support for the reasonable selection of parameters of C.K.stubble machinery.