Abstract:
Jujube pit removing is the key technology of dried jujube deep processing. Currently, it is very common that the dried jujube pit extractor has a lot of defects. We designed a chained pneumatic punching automatic dried jujube pit removing machine to solve the existing technical problems. The whole machine was composed of a chain roller for feeding, a camera for collecting the images of jujubes transmitted on the conveyor, locating mechanism, and a jujube pit mechanism with spinning inserting rod driven by an intermittent cylinder. All of them were controlled by an embedded microchip. The feeding mechanism was mainly supported by a rolling conveyor chain. The locating mechanism worked in conjunction with the feeding mechanism. The lower conveyor chain of the feeding mechanism and the upper roller of the locating mechanism consisted of a synchronous clamping and a locating roller device. The dried jujube pit removing machine was made up of a magnetic valve, a driving damping cylinder, sets of rotary inserting rods and knockout rods, a speed-regulating rotary driven motor, a sliding table, and an air compressor. The embedded microchip controlling the whole jujube pit removing system was formed by STM32F407 image processor, STM32F103 coprocessor, Shanghai LJ12A3-4-Z/BX 3-way NPN sensor and HBS860H stepping motor. The whole structure could be divided into 3 parts according to the operating process, which included the jujube feeding area, the detecting area, and the clamping and jujube pit removing area. Under the programmatic control of microcontroller, the jujubes were transported by the chain roller. The elastic strip was fixed at the bottom of the feeding hopper, and the rubbing roller rotated to realize the individual directional arrangement of the jujube. The camera was adopted for image detection of the automatic alignment of the jujubes, and collected synchronous information from the camera was transmitted to the coprocessor and analyzed timely. The jujube with location information was conveyed to the jujube pit removing area, and the jujube was clamped by the synchronous roller. The coprocessor controlled the stepper motor to achieve directional intermittent stop and realize accurate alignment of the jujube in the jujube pit removing area. The inserted rods were launched and completed the jujube pit removing promptly in the transitory pause. Dried jujube pits were carried unceasingly by the roller conveyor chain and output directly. And the whole operating circle of the automatic jujube pit removing was completed. The dried jujubes used in the test were those whose diameter ranged from 20-30 mm and longitudinal ranges from 35-45 mm. The result showed that the average directional ratio was 98.3%, jujube pit removing rate was at least 93.75%, and the average crushing rate was 1.46%. In this paper, the automatic feeding jujube pit extractor achieved high efficiency of feeding jujubes one by one, meeting the demand of accurate detection and location. And it realized fast and efficient dried jujube pit removing and smooth unloading. According to the test results, the chained pneumatic punching automatic dried jujube pit removing machine adopted the chained roller conveying mechanism to realize the automatic orientation and feeding of the jujubes individually. The elastic bump roller which fit the size, shape and other characteristics of the dried jujube reduced the central height error of different sizes. The image detection working with the upper and lower roller clamping device were controlled by the embedded microchip to achieve high precision of locating and reduce the probability of invalid jujube pit removing operation at the same time. The whole machine realized the purpose of automatic feeding, accurate location and effective jujube pit removing.