Abstract:
Abstract: At present, the wine grape harvesting method is still the traditional manual picking with scissor, because the grape fruit is randomly distributed among the branches, the manual harvesting is difficult and the operation efficiency is low. Therefore, mechanized harvesting of wine grape has become an urgent need. Vibration harvesting is one of the main methods of fruit harvesting at home and abroad. The mechanical harvesting of blueberries, blackcurrant, grape and other berries mainly vibrates the fruit tree by means of incentive source, so that the fruit and the connected branches produced a relative movement, the joints produced deformation and fracture, and the fruits falling. However, the domestic wine grape harvesting machines are immature, which has great damage to plant, low threshing efficiency, high fruit broken rate, low reliability and so on. In order to meet the requirements of wine grape mechanization harvest, a crankshaft vibration threshing device was put forward, the device was mainly composed of crankshaft, clamping vibration mechanism, elastic vibration rod, synchronous belt driving system, frame and so on, the driving crankshaft and the driving crankshaft were connected by a synchronous belt, and the elastic vibration monomers composed of parallel crank and rocker mechanism on both sides were in the same phase and moved synchronously in the same direction. The wine grape plant was held by the clamping vibration mechanism on both sides, and was driven to perform a regular variable motion, so that the wine grape grains fall off the grape stem. The angular displacement and angular velocity of the working parts were obtained based on the kinematics analysis of the crank and rocker mechanism. The main factors affecting the vibration operation effect were the length and angular velocity of the crank. The elastic vibrating rod were divided into straight segment and arc segment. The material of PA6 nylon and PU polyurethane with high mechanical strength, flexibility and resilience were selected as the material of vibrating rods. Based on the elastic deformation theory of the elastic vibrating rod, the maximum deformation of the elastic vibration rod was calculated, the influence of the elastic deformation of the elastic vibration rod on the amplitude was analyzed, and the amplitude of the elastic vibration rod in the vibration state was obtained. Furthermore, the clamping spacing, rotating speed and eccentricity were selected as the influencing factors, and wine grape threshing rate and broken rate were selected as the response value for three factors and three levels two Sub-regression orthogonal test design, and the regression equations to describe the relationships between the factors and assessment indexes were established by using the regression analysis and response surface analysis with the software Design-Expert 8.0.6. The optimum combination of the selected parameters was obtained and verified, and the experimental verification of the mathematical model was also conducted. The test results showed that the factors had great effects on the performance of wine grape vibration threshing device. The significant effects of rotating speed, eccentricity and clamping spacing on threshing rate were in a decreasing order. The significant effects of rotating speed, clamping spacing and eccentricity on broken rate were in a decreasing order. Verification test results indicated thtat when the clamping spacing was 193 mm, the rotating speed was 720 r/min and the eccentricity was 38.8 mm, wine grape threshing rate of the device was 93.06% and broken rate was 1.54%, which was basically consistent with the prediction results of model optimization, and the structural design was reasonable. This study provides a reference for the mechanization harvesting of wine grape and vibration harvesting of other fruits.