Design And Analysis Of Small Fruits Collecting Device With Flank Deployable And Foldable Mechanisms

Most fruit distribute in the subtropical and tropic zone, and usually grow in mountainous and hilly region. As the rising demand for fruit and in the adjustment of the structure of forestry in China, planting fruit trees at the flat ground has been popularized. The improvement of living standards makes labor costs increase. Therefore the fruit collection method has transformed from the manual operation into mechanical operation which is imperative. In this paper, in order to adapt to the mechanization collection of small fruit, based on the existing fruit collection equipment at home and abroad, taking the space deployable and foldable mechanisms as reference, focusing on the growing environment of the Chinese hickory trees, the design and analysis of small fruits collecting device with flank deployable and foldable mechanisms have been carried out, and the processing and manufacturing, assembly and trial, and experimental test of a prototype have been conducted. The main contents and achievements are as follows:1. Based on the Chinese hickory planting area at Lin’an, Zhejiang province, a deep investigation was conducted on the mountainous growing environment for the Chinese hickory trees and the flatground planting environment for the dwarf Chinese hickory trees. By analyzing the growing conditions of Chinese hickory trees of different ages, and investigating the height growth and canopy condition of most trees, the basic design parameters of the fruit collecting device with flank deployable and foldable mechanism were determined, and its application was analyzed. Following the planting trend of the Chinese hickory trees, and regarding the flat-ground planting of dwarf Chinese hickory trees as the key research object, the planting situations of the tree are as follows: line spacing is about 2.0m-2.5m, main fruit-bearing branch diameter distributes between 1.5m-3.7m, and the canopy is 1.5m-2.8m above the ground.2. According to the analysis of the existing fruit collecting machinery, the improved design of small fruit collecting device with flank deployable and foldable mechanisms was introduced, and the possible dead point position in the process of operation was analyzed. The device consists of three parts which are flank deployable and foldable mechanism, lifting mechanism and mobile clamping mechanism. The kinematics and dynamics of flank deployable and foldable mechanism which is the core mechanism were analyzed, and optimized the dimension which was programmed by using Matlab software. Based on the constraints of the bar size, the optimal bar size was obtained. The obtained results were used to modify the 3D model of the flank deployable and foldable mechanism. The deformation and stress of the mechanism while impacted from of the falling hickories were analyzed by finite element analysis, and then it was determined whether the strength met the requirements. The dynamic simulation of this mechanism was conducted in ADAMS, and the driving moment of the deployable and foldable mechanism was 2.64 N?m. And the simulation curve was compared with the theoretical curve, and the device was determined to be double-semicircle three-part mechanism.3. The processing and manufacturing and debugging of the prototype have been completed, and its deployable and foldable performance and collecting rate has been tested. Using the Phantom v5.1 high-speed camera to capture the trajectory of deployable and foldable mechanism, the theoretical trajectory was compared with the simulation trajectory to ensure the precision of mechanism design. A stepping motor was used as the driving motor, and the motor speed was changed to select the optimal value. Due to the season factor, maidenhair tree and winter jujube tree were chosen as the experiment subjects, and to the collecting rate was measured at 66.71% and 84.68%, respectively. The test results were analyzed and provide a reference to the subsequent improvement of device.