基于多体动力学的圆盘式开沟机虚拟仿真与功耗测试

Virtual Simulation and Power Test of Disc Type Ditcher Based on Multi-body Dynamics

目前圆盘式开沟机功率消耗主要通过理论计算或样机试制后的田间试验等方法得出,测试结果受环境、设备精度影响较大,为此提出了利用虚拟测试平台评估圆盘式开沟机功率消耗的方法。首先建立圆盘式开沟机工作部件的ANSYS动力学模型,并进行边界约束条件和载荷设置,分别模拟圆盘式开沟机在开沟深度400 mm、前进速度0.8 km/h、刀盘转速180 r/min和开沟深度500 mm、前进速度1.5 km/h、刀盘转速220 r/min 2种工况下的功率消耗,仿真结果为31.26 kW和32.67 kW;然后构建相同工况的田间功耗测试系统,测得的实际功耗为33.57 kW和35.41 kW,仿真值与实测值相对误差分别为6.88%和7.73%,验证了该种测试方法的准确性和可行性。最后分别选取3种开沟深度、2种前进速度和3种刀盘转速因素组成18种开沟工况,对其进行仿真分析,结果表明:刀盘转速在200 r/min时,无论前进速度高低,圆盘式开沟机均具有最低的功耗。

Aiming at the problem of that the power consumption of disc type ditcher is difficult to test,a virtual test platform evaluation disc type ditcher set power consumption method was proposed. Firstly,the dynamics model of disc type ditcher was established. In order to shorten the operation time, the secondary characteristics such as chamfer,fillet and connection were omitted. The boundary conditions and loads were set up. The virtual simulation of power consumption in disc type ditcher was carried out with trenching depths of 400 mm and 500 mm,forward speeds of 0. 8 km / h and 1. 5 km / h,rotation speeds of 180 r / min and 220 r / min,respectively. The power curve of ditch process showed that at the beginning of soil cutting,power consumption was increased quickly,the reason for which was a great deal of power consumption was needed during the process of soil deformation and broken. After that the power consumption was tended to be stable,for the reason of which was the binding force was tended to be less after the soil particle was destroyed. Then the field power test system was built and the relative errors were 6. 88% and 7. 73%,respectively,compared with simulation results. The accuracy and feasibility of the proposed method were verified. Finally,totally 18 conditions（ three trenching depths,two forward speeds,and three rotating speeds） were selected to carry out the simulation. The results showed that with a certain trenching depth,the disc type ditcher had an increasing linear relationship with forward speed and rotation speed. With a certain ditching depth and forward speed,the lowest power consumption was appeared at rotation speed of 200 r / min. Moreover,with a large trenching depth and forward speed,theeffect of rotation speed on power consumption was obvious. When the rotary speed was 200 r / min,both low and high speeds,disc type ditcher had the lowest power consumption value. According to comparison at rotary speed of 219 r / min in different ditching depths and forward speeds,the power consumption at rotary speed of 200 r / min was decreased by 8. 5 kW,9. 6 kW and 4. 6 kW,the results provided a theoretical basis for power consumption measurement of rotary ditcher.