Apparatus for electrostatically spray-coating workpiece with paint

An apparatus for electrostatically spray-coating a workpiece with conductive paint, said apparatus comprising:

• a grounded conductive paint feed source for supplying the paint through a supply line;
• an intermediate reservoir for temporarily storing the conductive paint therein and for delivering the conductive paint stored therein to a spray gun;
• and
• an insulation mechanism for electrically insulating said conductive paint feed source from said intermediate reservoir, said insulation mechanism comprising:
• a first three-way changeover valve having first and second ports connected to said conductive paint feed source and a first flush valve respectively, and a third port connected to one end of an insulated line and capable of selectively communicating with said first and second ports;
• a second three-way changeover valve having a fourth port connected to the other end of said insulated line, and fifth and sixth ports connected to said intermediate reservoir and a waste-liquid tank respectively and said fifth and sixth ports being capable of selectively communicating with said fourth port;
• a spray gun connected via a delivery line to said intermediate reservoir;
• a discharge line branched from said delivery line via a changeover valve;
• a second flush valve selectively supplying at least cleaning liquid and air to said discharge line, said second flush valve being provided separately from said conductive paint feed source for said supply line;
• and
• means for applying a high voltage to the conductive paint between said second three-way changeover valve and said spray gun.

An apparatus for electrostatically spray-coating a workpiece with water-based conductive paint, said apparatus comprising:

• a grounded water-based conductive paint feed source;
• an intermediate reservoir for temporarily storing the water-based conductive paint therein and for delivering the water-based conductive paint stored therein to a spray gun;
• conductive paint feed means for supplying the water-based conductive paint to said intermediate reservoir from said water-based conductive paint feed means, said conductive paint feed means having an electrically-insulated portion formed in at least a part thereof;
• means for washing said electrically-insulated portion with thinner solvent;
• means for drying said electrically-insulated portion;
• leakage current measuring means provided on said electrically-insulated portion, wherein the thinner solvent for removing a resin component of the conductive paint remaining in said electrically-insulated portion can be supplied from said means for washing said electrically-insulated portion into said electrically-insulated portion when a measured value outputted by said leakage current measuring means exceeds a predetermined value;
• and
• thinner solvent feed means for supplying the thinner solvent to remove the resin components of the conductive paint, which remain in said electrically-insulated portion.