Structure Design And Process Analysis Of Vacuum Electrostatic Coating Equipment

Vacuum electrostatic coating equipment, an electrostatic spray paint equipment used in vacuum condition, is mainly applied to the coating decorations of civilian industry product and defense industries, such as automobiles, motorcycles, household appliances, toys, furniture fittings etc. The equipment and process mainly involve the mechanical industry, electrical industry, chemical industry etc. The equipment joins surface pretreatment before coating, vacuum electrostatic coating, paint curing, waste paint and solvent recovery together, so as to address certain problems existing in coating industry, namely, low efficiency, high energy consumption, poor quality, high pollution and the difficult recycling of solvent waste paint. As a consequence, people-oriented advocation is fulfilled through ensuring product quality, environmental protection, high efficiency, emission reduction and reduced production costs.During the process of developing the vacuum electrostatic coating equipment, my main job includes some of the mechanical structure design and analysis, as well as coating process research. The concrete content is as follows:Firstly, the structure of coating vacuum chamber was designed according to the requirement of vacuum electrostatic coating process. Stress and fatigue analysis of the coating vacuum chamber box was operated, and the results were taken into consideration in improving the structure of the box locality ribs. The wall thickness of vacuum chamber box was decreased from15mm to10mm; vacuum chamber back-end box structure and size of chain were studied, which met the requirements of safety of spray gun’s high-voltage electrostatic field and the intensity; the front and back vacuum chamber dodge gate the bolt shaft were analyzed in stress; as for the openings, reinforcement design was carried on; the back-end lid of vacuum box was altered to a circular arc dodge gate that facilitates fixing and maintenance of equipments; a tightened device of dodge gate was designed.Secondly, a spray gun lifting mechanism was designed. A chain drive mode was adopted, and the overall height was reduced by840mm; motor was installed outside the vacuum chamber, solving the problem of the motor cooling; a dynamic seal was designed, solving the drive shaft vacuum sealing problem.Finally, the optimum coating parameter of the vacuum electrostatic coating process was obtained via orthogonal experiments. Many factors affecting the coating quality were analyzed so as to identify a five-factor three-level orthogonal test, through range analysis of experimental data, the preliminary optimal scheme was obtained thereafter; the second experimental design arranged a three-factor two-level orthogonal test and the optimum coating parameter was obtained, that is, viscosity of paint is20s, vacuum is50000Pa, electrostatic voltage is70kV, spraying time is40s.All the designs proposed in this paper, including the coating vacuum chamber structure, spray gun lifting mechanism, the best coating parameters obtained by orthogonal test method, have been proved in actual production. In this sense, this paper can provide theoretical support for further study of the vacuum electrostatic coating equipment and vacuum electrostatic coating equipment process.