| Currently, auto-insert assembly technique has become one of the keys to production of electronics, especially for assembling of electronic components on printed-circuit board (PCB). However, most electronics manufacturers in China, especially the household appliance manufacturers still use the dated manual-insert assembling method. This dated assembling method has many disadvantages, including low work efficiency, high labor cost, poor producing quality (wrong-insertion, miss-insertion), and heavy management task. This thesis focused on designing of an auto-insert machine for irregular electronic components to replace the dated manual-insert assembling method. Those problems caused by the dated manual-insert assembling method are no longer problems to the auto-insert machine.This thesis introduced types and incoming ways of the commonly used electronic components, such as resistors, capacitor, and transformers. Then we analyzed technical features and working modes of RG131, AV132 (PANASONIC, abroad) and SCIENCGO 4000 series (domestic) auto-insert machines for common electronic components, particularly their automatic feeding systems and auto-insert systems. Through analyzing of manual-insert assembly line of irregular electronic components of a typical product, we elaborated technical features and existing problems of the traditional manual-insert assembling method. This thesis reviewed the present situation and the development trend of the auto-insert machines for irregular electronic components in domestic and foreign countries, aimed to solve the existing problems.Based on the design process analysis of irregular electronic component auto-insert machine, determined design parameters were requirements, carried on the division of the functions of each module, analysis main content and design theory of auto-insert machine, Analysis manufacturing technology of the standard PCB and irregular electronic component, determine the size of PCB Board and electronic component, it gave a basis for subsequent electronic components automatic insert on the PCB Board. Analyzing the freedom needed to achieve automatic insert requirements, described body structure, automatic feeding and blanking system for PCBs, automatic feeding system for irregular electronic components. Put forward the machine control system proposal based on motion control card. Analysis and put forward solutions for key technologies.Chose MKP-X2 safety capacitor (electronic component) as the study object after considering the automatic insert ability. The design of repositioning accuracy is±0.04mm、plugging efficiency is 2000-2500pcs/h、defective rate is less than 800ppm. Adopt Cartesian structure design with 6 degrees of freedom (DOF) for the auto-insert machine. Design a single automatic insert period of 1.6s, Analyzed working procedures of the auto-insert machine according to the technical requirements, and allocated working time for each procedure. Based on the feasibility of the automatic insert technologies, performed design and model selection of the machine, including the servo axis, automatic feeding and blanking system for PCBs, automatic feeding system for irregular electronic components, the compact rapid electrical servo clamping jaw. The thesis analyzed influence factors that may cause vibration of the machine, and performed improved design to reduce the vibration. Set up the calculation formula of vibrating direction angle, vibration strength and frequency of the vibrator. From the perspective of improving reliability of the machine and reducing the failure rate, a sizing mechanism is specially designed for pins of MKP-X2 component.Simulation and tests were carried out to verify and optimize the machine. By using the finite element analysis software named ANSYS, in this thesis, the modal analysis and harmonic response of the auto-insert machine are simulated. The results shown that external citation with frequency of 34.596Hz to the machine should be avoided to prevent resonance.3 sets of MKP-X2 safety capacitors were used to perform horizontal-type sizing tests, the other 3 were used to perform vertical-type sizing tests. The tests shown that the center distance tolerance zones are(-0.16,+0.04) mm and (-0.05,+0.07)mm respectively for the pins of MKP-X2 safety capacitors after horizontal-type sizing and vertical-type sizing, while the resilience values are 0-0.2mm and 0-0.1mm respectively, which mean that vertical-type sizing mechanism is more feasible for improving the insert ability. Chose different positions on the auto-insert machine (prototype) to test the repositioning accuracy, the test results are ±0.025mm and ±0.0265mm for X axis and Y axis respectively, the design requirement (±0.04mm) is fulfilled. |
PDF Full Text Request