基于TRIZ理论的半径可调式林果振动采收激振器设计与试验

Design and Test of Radius Adjustable Fruit Vibration Harvesting Exciter Based on TRIZ Theory

摘要:

针对现有激振器输出的激振力幅值和频率无法独立可调，造成激振力的幅值和频率无法同时满足林果振动采收需求的问题，利用TRIZ理论构建出激振器与果树物质-场模型。根据物质-场模型和物理冲突解决问题的方法，获得偏心块式激振器激振力振幅和频率独立可调的偏心块布局，提出了四偏心块激振器和半径可调式激振器方案。并通过2种激振器设计方案的动态性能对比发现，半径可调式激振器性能更优。以柑橘树为试验对象，利用半径可调式激振器对不同的果树施加3种不同频率和振幅的激振力。结果表明增大激振力频率，果实采净率呈增大趋势。同时激振频率一定时，增大激振力幅值，果实采净率也呈增大趋势，当激振频率为19Hz、丝杠螺母行程为70mm时，果实平均采净率为86.3%。通过试验对比发现，激振频率对果实采净率影响程度大于激振力幅值的影响程度。半径可调式激振器能够改变激振力幅值，提高果实采净率。同时半径可调式激振器具有幅频独立调节特性，当激振力频率较大时，降低振幅以够防止果树损伤。

Abstract:

In order to solve the problem that the magnitude and frequency of excitation force output by existing exciter cannot be adjusted independently, the amplitude and frequency of excitation force cannot meet the demand of fruit vibration harvesting at the same time, TRIZ theory was used to construct the model of exciter and fruit tree matter-field. According to the matter-field model and the physical conflict solving method, the eccentric block layout of the excitation force amplitude and frequency of the eccentric block exciter was obtained, and the schemes of the four eccentric block exciter and the radius adjustable exciter were proposed. By comparing the dynamic performance of the two designs, it was found that the moment of inertia of the radius adjustable exciter was lower than that of the four eccentric blocks. The smaller the moment of inertia of the shaker was, the smaller the torque and power required during the rotation of the shaker was. When the four eccentric blocks were rotating, the phase angle size of each eccentric block was changed with time, so it was very difficult to adjust the size of the phase angle φ. In the radius adjustable exciter, the eccentric block and the rotating axis were relatively fixed in the radial direction, and the eccentric block radius was relatively static in the axial direction, and it was relatively easy to adjust the eccentric block radius in the axial direction. Therefore, the radius adjustable exciter was more suitable for the amplitude-frequency regulation mechanism of exciting force in the process of fruit vibration harvesting. Three different frequencies and amplitudes were applied to citrus trees. Citrus trees were used as test subjects to apply three different frequencies and amplitudes of excitation forces to different fruit trees with adjustable radius exciter. The results showed that the detachment rate of fruit was increased with the increase of the frequency of excitation force. At the same time, when the exciting frequency was constant, the amplitude of the exciting force was increased, and the detachment rate of the fruit also showed an increasing trend. When the exciting frequency was 19Hz and the stroke of the screw nut was 70mm, the average detachment rate of the fruit was 86.3%. The results showed that the effect of excitation frequency on the detachment rate was greater than that of excitation force amplitude. The radius adjustable exciter can change the amplitude of the exciting force and improve the fruit harvest rate. At the same time, the amplitude-frequency independent regulation characteristic of the radius adjustable exciter can reduce the amplitude to prevent the damage of fruit trees when the excitation force frequency was large.