侧枝激振耦合式核桃采果方法与装置研究

Lateral Branch Excitation Coupled Walnut Fruit Harvesting Method and Device

摘要:

针对现有便携式核桃侧枝振动采果装置所需采果激振力与侧枝物理特性之间耦合关系不明晰的问题，提出了侧枝激振耦合式核桃采果的方法，基于采果激振力频率与核桃侧枝固有频率相同从而形成激振耦合的理论分析，建立了激振采果参数与侧枝物理特性之间的激振耦合采果理论模型，进行了侧枝激振耦合条件下激振加速度和激振力仿真分析，设计了侧枝激振耦合式核桃采果装置，分析了侧枝激振耦合式核桃采果装置采果性能，并对侧枝激振耦合式核桃采果装置采果性能进行了试验验证。试验结果表明，采果激振力频率越接近侧枝的固有频率，侧枝与激振力之间越易形成激振耦合。对于核桃侧枝直径和激振加载位置与主枝干距离分别为：30 mm和1 313 mm、40 mm和1 552 mm、50 mm和1 686 mm，采果装置额定功率为300 W，激振力振幅为15 N，激振力频率为侧枝固有频率8.80、8.40、8.90 Hz时，侧枝振动加速度仿真值分别为69.2、56.1、72.9 m/s2，试验值分别为66.4、56.3、74.2 m/s2，两者相一致。当单枝侧枝挂果质量为2.0 kg时，采果效率可达60.0 kg/h，采净率与果实成熟度密切相关。

关键词:核桃采果机械;侧枝激振耦合;振动落果条件;激振力;采果效率

Abstract:

For the existing portable walnut side branch vibration fruit picking device required fruit picking excitation force and side branch physical characteristics of the coupling relationship between the problem is not clear, the side branch excitation coupling walnut fruit picking method was put forward, in the theoretical analysis of the picking load excitation force frequency and walnut side branch inherent frequency was the same so as to form the excitation coupling-based on the theoretical analysis of the excitation picking parameters and the side branch of the theoretical model of the physical characteristics of the coupling between the excitation picking parameters and the side branch excitation, the excitation acceleration and coupling excitation force under the coupling conditions were analyzed through simulation analysis of the side branch excitation, the side branch excitation coupling walnut fruit picking device was designed, the fruit picking performance of the side branch excitation coupling walnut fruit picking device was analyzed, and the fruit picking performance of the side branch excitation coupling walnut fruit picking device was experimentally verified. The results showed that the closer the frequency of the fruit picking excitation loading force was to the intrinsic frequency of the lateral branch, the easier it was to form an excitation coupling between the lateral branch and the excitation loading force. For the diameter of walnut lateral branches and the distance of the excitation loading position from the main branch stem were 30 mm and 1 313 mm, 40 mm and 1 552 mm, 50 mm and 1 686 mm, and the rated power of the fruit picking device was 300 W. When the amplitude of the excitation loading force was 15 N and the intrinsic frequency of the lateral branches were 8.80 Hz, 8.40 Hz and 8.90 Hz, respectively, the simulated values of lateral branch vibration acceleration reached 69.2 m/s2, 56.1 m/s2 and 72.9 m/s2, respectively, and the experimental values were 66.4 m/s2, 56.3 m/s2 and 74.2 m/s2, which were consistent with each other. When the fruit hanging mass of single lateral branch walnut was 2.0 kg, the fruit picking efficiency reached 60.0 kg/h. The walnut fruit picking net rate was closely related to the maturity.

Key words:walnut picking machinery;lateral branch excitation coupling;conditions of fruit falling by vibration;excitation force;harvesting efficiency