Patent ID: 7926443
Filing Date: 2011-04-19
Classification: B05B

Abstract:
1. An electrostatic coating apparatus, comprising: a coating machine for spraying paint to a coating object, said coating machine including an air motor rotationally driven by drive air, a rotational shaft rotated by said air motor, a rotary atomizing head provided at a distal end of said rotational shaft for spraying paint supplied through a paint supply valve while being rotated by said rotational shaft, and a shaping air ring provided on an outer side of said rotary atomizing head and having air outlet holes for spouting shaping air to form a paint spray pattern; a high voltage generator for boosting a power supply voltage to generate a high voltage and for outputting said high voltage to said coating machine; a power supply voltage control unit for controlling a power supply voltage to be supplied to said high voltage generator; a high voltage control unit for outputting a setting signal to set a power supply voltage for said power supply voltage control unit and for controlling a high voltage to be output by said high voltage generator; full return current detection means for detecting a full return current that flows through said high voltage generator and for outputting the detected full return current as a full return current detection value; leakage current detection means for detecting a flow of a leakage current that does not pass through said coating object and for outputting the detected leakage current as leakage current detection values, said leakage current detection means including a drive air passage current detector for detecting a current that flows along a drive air passage for supplying said drive air, a shaping air passage current detector for detecting a current that flows along a shaping air passage for supplying said shaping air, and a supply valve drive air passage current detector for detecting a current that flows along a supply valve drive air passage to drive open and close said paint supply valve, and said leakage current detection values including said detected current that flows along the drive air passage, said detected current that flows along the shaping air passage, and said detected current that flows along the supply valve drive air passage; power supply cutoff means, associated with said high voltage control unit, for outputting a cutoff signal to said power supply voltage control unit to cut off the supply of said power supply voltage after deterioration of insulation for said coating machine is determined by employing the full return current detection value output by said full return current detection means and the leakage current detection values output by said leakage current detection means; alarm means for outputting an alarm that said reduction of insulation has occurred in said coating machine after reduction of insulation at an initial stage is determined by employing the leakage current detection values output by said leakage current detection means; and object current calculation means, associated with said power supply cutoff means, for subtracting a sum of the leakage current detection values output by said leakage current detection means from the full return current detection value output by said full return current detection means and calculating an object current that flows between said coating machine and said coating object.