Design And Experimental Study On The Self-Excited Vibration Subsoiler And Key Parts

Soil compaction resulting from traditional plough and rotary tillage below the normal tillage depth and large farm machinery presents a unique promble.As conservation tillage,subsoiling has been a important measure to improve soil qualities.High traction resistance and energy of the sobsoiler in the subsoiling tillage become the biggest obstacle of the subsoiling promotion.Self-excited vibration theory applied to soil tillage is the new method to reduce traction resistance and energy.This paper introduced the demestic and foreign development of the subsoiler and the designed a self-excited subsoiler based on the self-excited vibration theory.This paper used Soildworks to establish the three dimensional models and used ANSYS to analyze the statics of the key parts,and study the “soil-subsoiler” model based the EDEM method,finally conducted the field test.The main studies and conclusions are as follows:(1)According to the domestic and foreign types of the subsoiler,the self-excited subsoiler was designed based on the self-excited theory.Using solidworks to draw the three dimensional models of the whole machine.The key components,such as the self-excited springs,subsoiling part and the fixed pin of spring spindle were designed.The dimensions and types of three self-excited springs used in the test were determined.ANSYS was used to analyze the stress simulation of subsoiling part and the fixed pin of spring spindle,and analyze their equivalent stress graph,equivalent elastic strain graph and total deformation gragh.The main forced and transformative parts were strengthened to ensure their relaibility.Finally,Caxa was used to draw the two dimensional graphics,and the self-excited vibrating subsoiler was manufactured.(2)The soil particle models were established with a combination of spherical soil particle to distinguish the topsoil from the hard pan soil,the bounderline model was established between the subsoiler and the soil particle.Soil screen test and shear test were conducted to get paraments on the EDEM simulation,and EDEM was used to analyze the traction resistance in different velocity、tillage depth..The field experiment was conducted under different factors such as tillage velocity and tillage depth,and the results show that the traction resistance of the excited-vibration subsoiler was increasing with the increasing of tillage velocity and depth.(3)The filed test of the self-excited subsoiler was carried out,which take the non-vibration treatment as the controlled trials.The entire combination test was conducted to analyze the change of the traction resistance of the deep loosening shovel in different levels of different factors(tillage depth、tillage speed and spring type).The results showed that the traction resistance in vibrating treatments was smaller than that in non-vibration treatment,which indicated the self-excited vibrationg can reduce the traction resistance.The traction resistance was higher as the tillage depth or tillage speed decreasing in all differently treatment.The spring Ⅰand spring Ⅱhad more significant effect on reducing traction resistance than spring when the tillage depth Ⅲand tillage speed was small.Compared with non-vibration treatment,the traction resistance of spring Ⅱ was reduced by 47.79% when the tillage depth was 25 cm,andtillage speed was 2.5Km/h.The traction resistance of spring was reduced by 50.36% when the tillage depth was 25 cm and Ⅰtillage speed was 3Km/h compared with non-vibration treatment.What’s more,the traction resistance of spring was reduced by 65.44% when the tillage depth was 35 cm and tillage speed Ⅲwas 3.5Km/h compared with non-vibration treatment.All results indicated that types of spring had effects on the traction resistance reduction of the self-excited vibration subsoiler.(4)The subsoiling effect was evaluated by soil properties,such as soil penetration resistance,soil density,soil bulk density,soil moisture content,soil bulkiness and soil disturbance coefficient.The results showed that soil penetration resistance,soil density and soil bulk density were reduced in non-vibration treatment and self-excited vibration treatments after tillaging.Compared with non-vibration treatment,the soil penetration resistance of spring Ⅲwas reduced by 17.44% at >15-30 cm soil layer and 20.17% at 0-15 cm soil layer,while the soil penetration resistance of spring were 10.09% and 23.24%,respectively.Compared with nonⅡ-vibration treatment,soil density of spring was reduced by 6.02% at 0Ⅲ-15 cm soil layer and 16.29% at >15-30 cm soil layer,and its soil bulk density was reduced by 4.11% at 0-15 cm soil layer and 13.73% at >15-30 cm soil layer,while soil bulk density of spring waⅡ s reduced by 2.05% and 7.84%,respectively.There was no significant effect of soil bulk density between spring Ⅰand non-vibration treatment at all soil layers and of soil density between self-excited treatments and non-vibration treatment at >15-30 cm soil layer.The increment of traction resistance made spring compressed completely at deep soil layer,which made the effect of self-excited treatmen reduced.The soil moisture content of non-vibration,spring Ⅰ,springⅡ,and spring Ⅲwere 4.04%、11.27%、9.25% and 8.08% at 0-15 cm soil layer,respectively.The reduction of soil moisture content resulted form soil moisture evaporation.The soil bulkiness and soil disturbance coefficience of three travels were 16.47% and 55.49%,which met the requirements and indicated the self-excited subsoilng effct of self-excited subsoiler was good.