AUTOMATIC COLOR CHANGING DEVICE

PROBLEM TO BE SOLVED: To automate color changing control for a coating material, by providing specific constitution in an automatic color changing device, for automatically supplying the coating material by color to an extruder wherein the powder-like coating material is made viscous by an extruding screw to be extrudingly coated on a core line to be traveled. SOLUTION: This device is provided with a material supplying means 6 for supplying plural coating materials C, changed by color, to the material charging part 2b of a extruder 2, a photodetector 8 provided on a material charging part 2b and detecting the charging upper and lower limits H and L of the coating material C to be charged, a measuring tool 7 for measuring the length of an electric wire extrudingly coated by the extruder 2, and a rotation frequency detector 10 for detecting the rotation frequency of an extruding screw 9. Moreover an operation controller 11 is provided which is receiving pulse signals from the measuring tool 7 and the rotation frequency detector 10 and a signal from the photodetector 8 to control the material supplying means 6. Consequently, constant observing is eliminated in the case of changing color, and even an electric wire or cable, having a short size and many color kinds, can be produced with proper productivity.