| Carya cathayensis loved by the masses has high nutritional value.Its nuts not only has a unique taste,but also has therapeutic value.With pecans gradually become popular high grade nuts,the demand for pecan products is on the growing.But the pecan picking technology lags.Low level of mechanization seriously hindered the rapid development of pecan industry.At present,China's pecan picking way is still artificially beating the tree which is high labor intensity,high labor costs,low operating efficiency.In order to reduce the labor intensity,reduce the labor cost and improve the working efficiency,this paper systematically investigates the existing nuts picking equipment on the market,and on this basis,successfully developed high altitude portable humanoid tapping pecan picking machine.The main work of the paper is as follows:(1)The test of the separation of fruit and tree branch.The separation force of 0 °,30 ° and 60 ° in the direction of the natural growth direction of the pecan fruit was measured with a dynamometer.The size of the separation force was recorded at different angles and the specific separation of pecan fruit was observed in order to determine the kinetic mechanism parameters of the pecan picking machine,which can provide a reliable theoretical basis for the subsequent prototype production.(2)The overall design of pecan picking machine.The design of the mechanical structure of the pecan picking machine was carried out to determine the parameters of the eccentric cam mechanism and the ADAMS analysis of the flapping mechanism was carried out.The ponchoating mechanism was designed.The structural scheme of the telescopic mechanism was analyzed comprehensively and the The Pro / E software was used to prototype the pecan picking machine.At the same time,ABAQUS was used to analyze the key components of the picking machine.The first six natural frequencies and main modes of the telescopic rod were calculated.The structural design and optimization of the telescopic rod provide a reliable basis to avoid the resonance of the machine during the operation.Finally,the technical parameters of the machine are obtained.Through the theoretical analysis and calculation,the choice of the power plant and the transmission mode is determined.(3)Experimental study on pecan picking based on principle prototype.According to the experimental data,the variance analysis and regression analysis were used to study the effect of the beat frequency on the fruit yield.At the same time,the injury of shoots was observed.The results showed that the significant level was 0.05,fruit yield has a significant impact,the net rate will increase with the beat frequency increases,which is consistent with the theoretical model analysis.To meet the removal rate and ensure the buds are not damaged,the beat frequency is controlled at 10 ~ 13.33 Hz.According to the regression model equation,the average removal rate can reach to 85.1% ~ 90.3%,while the uncollected fruit can be harvested again or artificially harvested.The design and manufacture of pecan picking machine in this paper adapted to the mountain high,slope,different height of the fruit picking.With its small size and easy to carry,it can pick down the fruit on the pecan tree branches through the high efficiency of tapping.Its picking performance is better than the existing market equipment. |
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