Research On The Influence Of Micro-cone Hole Processing On The Performance Of Piezoelectric Atomization Devic

Piezoelectric atomization is a process of dispersing liquid into fine particles by piezoelectric drive technology.Piezoelectric atomizer is widely used in inhalation therapy,inkjet printing,spray cooling,biomedicine,spray processing and other fields because of its simple structure,low production cost and portability.Compared with the traditional ultrasonic atomizing device,the micro-tapered hole atomizing device uses piezoelectric ceramics as the driving source,which has the advantages of simple structure,easy to carry,high atomizing efficiency and low production cost.In order to obtain atomized droplet groups with small particle size and uniform distribution,most of the studies on micro-cone-hole atomizer have focused on the optimization of piezoelectric driving parameters and the optimization of atomizer structural parameters.However,the metal atomizer with micro-cone-hole group is the core component of micro-cone-hole atomizer,and the influence of cone hole processing technology and manufacturing accuracy on the performance of the atomizer has not been mentioned.Therefore,this topic will take the machining process of the cone-hole group on the micro-cone-hole atomization plate as the research object.Through experiments,the influence of the current methods and processes of laser processing of cone-holes in the industry on the machining accuracy of micro-cone-hole is studied.Theoretical models are established to find the key factors affecting the machining accuracy,and improvement methods are proposed.The atomization performance of the improved atomizer was tested by experiment.Specific work contents are as follows:(1)The structure and parameters of atomizer and atomizer are investigated.The measuring method of cone-hole of metal sheet is analyzed.A multi-aperture measurement method based on machine vision is proposed,which eliminates the subjective factors in the measurement process and greatly improves the measurement efficiency and reliability.(2)The diameter of atomizing plate used in atomizing industry was measured by the method mentioned above.The measurement results show that,compared with the machining set value,the mean deviation of the diameter of the large hole and the small hole of the atomizing plate used in the industry at present is 15.15% and 14.33%,and the variance deviation is 59.69% and 110.00%.The mean deviation and the variance deviation of the large hole are much larger than the allowed value,indicating that the diameter of the cone hole has a great deviation from the preset value.Therefore,there are interference factors in the processing process.(3)The mathematical model of laser processing is established.In order to determine the interference factors mentioned above and quantitatively analyze the influence of each factor on the aperture deviation of the final machining,a vibrationaperture model of the laser processor is established.The model of laser machining under three processes is established.The final aperture can be determined by the aperture of the first process determined by the internal algorithm of the laser.It lays a foundation for quantitative analysis of the influence of internal and external parameters on the aperture machining deviation.According to the above model and experiment,it is determined that the aperture machining deviation caused by external vibration in this study is 0.61 um,accounting for 20.13% of the total deviation.Due to the large initial spot diameter caused by the laser internal algorithm,the aperture error accounts for68.32% of the total error.(4)Based on the above two influencing factors,the improvement method is given.For the influence of external vibration,the vibration interference caused by external environment is reduced by installing a damper on the laser processor;For the influence of internal machining algorithm,the suitable initial machining spot diameter is derived through the laser machining model of microcone-hole under three processes,so as to reduce the machining error.The diameter of the cone hole of the metal sheet after redrilling is measured.The experiment shows that the deviation of the big end aperture and small end aperture of the improved atomization plate cone hole is reduced to 4.60%and 4.33%,and the variance is reduced to 3.75% and 3.20%,both the mean deviation and variance deviation are within the allowable range,thus verifying the feasibility of the improved method.(5)Test the atomization performance of the atomizer before and after the improvement.Through modal simulation and sweep frequency experiment,8 suitable operating frequency points were selected to carry out subsequent experiments on atomization rate,atomization height and atomization particle size,among which atomization particle size was the most important index.The experimental results show that the diameter of atomized plate decreases by 6.28%.The reduction of atomized particle size has important significance and broad application prospect in the field of inhalation therapy.