Electrostatic coating apparatus and electric conductivity check method
An electrostatic coating apparatus includes a coating gun that sprays a coating material toward a coated matter, a high-voltage application apparatus that applies a high voltage to the coating gun, a bell-side current calculation unit that calculates a bell-side current to flow from the coating gun to the coated matter, an earth-side current measurement unit that measures an earth-side current to flow from the coated matter to the earth, and an earth check unit that detects an abnormal earth state of the coated matter, depending on a magnitude relation between the bell-side current calculated at the time of electrostatic coating and the bell-side current when the earth is properly connected, and a magnitude relation between the earth-side current measured at the time of the electrostatic coating and the earth-side current when the earth is properly connected.
1. An electrostatic coating apparatus comprising:
a coating gun that sprays a coating material toward a coated matter;
a high-voltage application apparatus that includes a bell-side current calculation unit and that applies a high voltage to the coating gun, the bell-side current calculation unit calculating a bell-side current flowing from the coating gun to the coated matter;
an earth-side current measurement unit that measures an earth-side current flowing from the coated matter to the earth; and
an earth check unit that detects an abnormal earth state of the coated matter, depending on a magnitude relation between the bell-side current calculated at the time of electrostatic coating and the bell-side current when the earth is properly connected, and a magnitude relation between the earth-side current measured at the time of the electrostatic coating and the earth-side current when the earth is properly connected.
2. The electrostatic coating apparatus according to claim 1 , wherein
the earth check unit detects the abnormal earth state of the coated matter, based on a difference between a ratio of the bell-side current and the earth-side current measured at the time of the electrostatic coating and a standard value that is set based on a ratio of the bell-side current and the earth-side current when the earth is properly connected.
3. An electric conductivity check method in an electrostatic coating apparatus, the electrostatic coating apparatus comprising: a coating gun that sprays a coating material toward a coated matter; a high-voltage application apparatus that includes a bell-side current calculation unit and that applies a high voltage to the coating gun, the bell-side current calculation unit calculating a bell-side current flowing from the coating gun to the coated matter; and an earth-side current measurement unit that measures an earth-side current flowing from the coated matter to the earth,
the electric conductivity check method comprising:
calculating the bell-side current as a first measurement value and measuring the earth-side current as a second measurement value at the time of electrostatic coating; and
detecting an abnormal earth state of the coated matter, depending on a magnitude relation between the calculated first measurement value and the bell-side current when the earth is properly connected, and a magnitude relation between the measured second measurement value and the earth-side current when the earth is properly connected.
4. The electric conductivity check method according to claim 3 , wherein
the abnormal earth state of the coated matter is detected based on a difference between a ratio of the bell-side current calculated at the time of the electrostatic coating and the earth-side current measured at the time of the electrostatic coating and a standard value that is set based on a ratio of the bell-side current and the earth-side current when the earth is properly connected.