Authors

Abstract

To investigate the vibration characteristics of the Thinker Agricultural Machinery 4LZ-2.0 crawler-type combine harvester under operational conditions, vibration tests were conducted on the chassis frame at three different engine speeds: 2700 r/min, 1500 r/min, and 800 r/min. A static analysis was initially performed to identify regions of significant stress and deformation on the chassis frame, which guided the placement of measurement points for collecting vibration acceleration data. Subsequent processing of the acceleration data in the frequency domain revealed the variation in vibration velocity at each measurement point on the chassis frame. It was found that as the engine speed increased, the excitation frequencies from the vibrating screen and cutting platform appeared as dominant resonance frequencies at nine out of twelve measurement points on the chassis frame. By referencing the international standard ISO 20816, it was determined that most of these measurement points fell into Class D, indicating a high level of vibration severity. To mitigate the vibration of the chassis frame, two measures were implemented: enhancing the structural rigidity of the frame and reducing the area of the center of mass trajectory of the vibrating screen. Following these modifications, re-testing showed that the average vibration intensity at the three maximum vibration measurement points of the chassis in the high engine speed condition successfully decreased by 34.57% compared to the original structure.

Abstract in Chinese

为了解收割机运行状态下底盘机架振动特性，以星光农机4LZ-2.0型履带式联合收割机为研究对象，在发动机处于2700r/min,1500r/min,850r/min三种不同转速下对其底盘机架进行振动测试。首先通过静力分析找到底盘机架应力与变形较大的区域，并以此在其表面布置测点，采集振动加速度数据。通过在频域内对加速度数据进行处理得到底盘机架各测点振动速度变化情况。发现随发动机转速提升，振动筛与割台的激励频率在收割机底盘机架12个测点中9个测点作为主振频率出现。结合国际标准ISO 20816，发现这些测点大多处于振动等级最大的D级，振动强度过大。为减小收割机底盘机架振动，采取增强机架结构、减小振动筛质心运动轨迹面积两种措施。经重新测试，发动机高转速状态下底盘3个振动最大测点各方向平均振动强度较原结构成功降低34.57%。