深松旋耕碎土联合整地机设计与试验

为减少耕作阻力、改善土壤耕层结构、提高碎土率,该文对联合整地机的深松部件、碎土机构进行设计,设计了入土角度可控的自激振动深松铲,并建立了自激振动深松铲的运动学模型和力学模型,确定弹簧行程为15mm、负载为7 500～15 000 N,并确定了弹簧的结构参数。设计了具有二次碎土功能的笼状碎土辊,并依据农艺要求确定了其结构参数。通过室内土槽试验,验证了自激振动深松铲的减阻效果和耕作质量,并对整机的作业质量进行了田间测试。土槽试验结果表明:与对照相比,自激振动深松铲平均减阻9.22%,土壤蓬松度和土壤扰动系数分别为26.16%和77.21%,减阻效果明显,作业效果较好。田间试验结果表明:联合整地机的深松深度稳定系数、旋耕深度稳定系数、地表平整度和植被覆盖率分别为94.92%、92.50%、1.17 cm和93.36%;笼状碎土辊在整个试验过程中未出现土壤粘附和拥堵现象,碎土率为84.18%,加装普通齿状碎土辊机具的碎土率为71.41%,笼状碎土辊的碎土率提高了12.77个百分点,碎土效果明显改善。深松旋耕碎土联合整地机减阻效果明显、整地质量好,可有效改善土壤的耕层结构,降低土壤容重,提高蓄水保墒能力。

Design and test of soil preparation machine combined subsoiling, rotary tillage and soil breaking

Abstract: In order to reduce tillage resistance, ameliorate the soil layer structure and improve soil breaking rate of soil crushing roller, a combined tillage machine which has function of subsoiling, rotary tillage and soil breaking was designed in this paper. The machine mainly consists of a fixed mount to connect the subsoiler, rotary and soil crushing roller with the machine frame, the self-excited vibration subsoiler breaks the bottom of the plow pan, the rotary tiller flattens the soil and further shreds the soil, the soil crushing roller further breaks the soil thus creating a seedbed suitable for plant growth. 2 major components of machine are optimized to solve the problem of large tillage resistance and poor soil breaking effect. Firstly, the self-excited vibration subsoiler with controllable penetration angle was designed, which can avoid the problem of poor drag reduction effect and stability of tillage depth when the penetration angle of subsoiler is too large. The subsoiler produces a vibration to loosen the soil to achieve the purpose of drag reduction because of resistance changes in soil operation. In addition, the penetration angle of subsoiler is controlled to a range to maintain the stability of subsoiling depth. To ensure the compression spring can not be tilted during the subsoiling operation, and considering the problem of large load and limited installation space, the combination spring is selected as the self-excited vibration spring. Through the kinematics and mechanical model of self-excited vibration subsoiler, the deflection is 15 mm and the minimum and maximum loads are 7 500 and 15 000 N respectively, then the parameters of the combined spring was determined. Secondly, in order to realize the secondary soil-broken function, a caged soil crushing roller was designed by staggered welding of rhombic soil-broken teeth on a cylindrical drum with clearance. The soil is first broken by the outside teeth of soil-broken tooth, and the large soil will enter the cylindrical drum inside through the gap and will broken under the action of inside teeth, which can''t adhere to the cylindrical drum. The caged soil crushing roller diameter and thickness of soil-broken teeth is calculated according to the design formula of the disc harrow. To study the drag reduction effect and tillage quality of self-excited vibration subsoiler, the experiment in the soil bin is carried out, and the field experiment of operation performance of the machine is carried out. The soil bin experiment results showed that the self-excited vibration subsoiler has obvious effect on drag reduction, and the average drag reduction is 9.22%, and the soil fluffy degree and disturbance coefficient is 26.16% and 77.21% respectively. The field experiment results showed that the stability coefficient of subsoiling depth, stability coefficient of depth of soil preparation, surface flatness, vegetation coverage and soil breaking rate is 94.92%, 92.50%, 1.17cm, 93.36% and 84.18% respectively. The soil breaking rate of ordinary soil crushing roller is 71.41%, which indicates that the caged soil crushing roller can effectively improve the soil breaking effect. Moreover, the caged soil crushing roller did not appear soil adhesion and congestion during the test. All parameters meet the requirements of the work quality standards. Therefore, the machine has obvious effect of reducing resistance and quality of the soil preparation. This study can provide a theoretical reference for further research of combined tillage machine of subsoiling and rotary.