| Vibratory feeder is one kind of feeding construction for automatic production andassembly system. Due to good patterning performance and generality, high feedingefficiency, the feeder is widely used in automatic machining, assembly and packaging.However, the vibration source of the traditional vibratory feeder is electromagnet, whichnormally requires50Hz or100Hz in working frequency, therefore, there are disadvantageslike high power consumption and working noise, complicated structure to do adjustment,etc. With the rapid development in advanced manufacturing, the products are tending to belighter, thinner, smaller and more precise, which makes the development of novel vibratoryfeeder more and more urgent. In the end of70s in20thCentury, rectangular piezoelectricbimorph was brought up in the first time as excitation source in piezoelectric vibratoryfeeder by Japanese. In the following decades, there were series achievements coming out,and nearly10invention patents were applied in piezoelectric feeding area. And there waswide application in automation production line. Chinese researches on piezoelectricvibratory feeder started from beginning of90s last century, and there are someachievements, but no innovation compared with Japanese products, and can’t be used formass production. The paper is one task from National Project863(Project number:2006AA04Z225)“Research&Development on Vertical Driven Piezoelectric VibratoryFeeder”. Novel vibratory feeding structures on annular piezoelectric vibrator was broughtforward. Based on this novel structure as the research objects, theoretical analysis,dynamic analysis, prototype design and production, experiment study were carried out. Thecontents in this paper includes:1. Referring to plenty of research materials, the development status of thepiezoelectric vibratory feeder home and abroad was deeply investigated. The vibratoryfeeding construction was summarized, and the advantages and disadvantages of the verticaldriven piezoelectric vibrator were pointed out.2. Through discoursing upon piezoelectric ceramics related characteristic and performance parameter, the performance parameter demand was obtained. Thepiezoelectric ceramics vibraiton mode fit for the feeder were defined, and also for the thepiezoelectric vibrator type, support mode, vibratory amplify form. The work here providedthe theory foudation for the feeder structure design, theoretical analysis and experimentstudy.3. Structural design was done on vertical driven piezoelectric vibratory feeder, and thedynamic analysis was carried out on the whole vibration system, therefore, the systemresponse theoretical formula and influence factors were received. Based on the systemtheoretical analysis result, theoretical design and optimization were done on the keycomponents of the feeder.4. Basic theory on piezoelectric driven feeder to form material delivery was analyzed,and the movement form of the material during delivery was analyzed; the mechanicalmodel was establised; the condition of the material vacate and slip, the hopper parameterinfluence on the movement condition are determined. The material movement averagespeed formula was deducted.5. Investigation was done on key component—vibratory hopper, from material,structure, parameter, variety, surface treatment, production process, and so on, theoreticalanalysis was done on the hopper; the main factors about the hopper on the influence of thematerial movement was determined.6. Prototype of vertical driven piezoelectric vibratory feeder was made, and theevaluation parameter and method on the system performance were defined. Experimentwas done from four different aspects, driving signal, hopper, material and vibration, andthe results were analyzed, from which the rules of influence factors on the system vibrationwere received. Based on the experimental results, the optimization direction wasdetermined for the prototype.Combined know-how on piezoelectricity, mechanics, control science and other area inthis paper, the working mechanism and dynamics characteristics of the novel designedpiezoelectric vibratory feeder were investigated deeply, and the performance of the feederwere tested systematically. Driven mechanism of the piezoelectric vibratory feeder wasenriched by the research from this paper, which provided the theory and experimentfoundation for the feeder performance improvement and the productivity of theindependent intellectual property on piezoelectric vibratory feeder. |
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