VARIABLE INDUCTANCE COIL DEVICE

PURPOSE:To realize water cooling for all areas permitting flow of a high frequency current in view of using for a high power by holding a coil with a driving arm which rotates around the center axis of both ends of short-circuitted conductor and cooling a conductor by supplying water into said short-circuitted conductor through a water supply and exhausting tube. CONSTITUTION:When a driving arm 12 is pushed upward against a spring 16 with a sliding piece 17 by driving a motor 20 in the driving arm holding devices 13 at both sides of driving device 14 and the motor 20 is forced to stop, a short- circuited conductor 11 provided at the end of driving arm 12 is separated from the coil lines 8 like arcs. When the motor 20 is rotated reversely and thereby the driving arm 12 is lowered, the short-circuited conductor 11 is pressurisingly in contact with the coil 8, owing to the spring 16. The upper and lower positions of arm sliding piece 17 are restricted by the upper position detector 18 and the lower position detector 19. The coils 8, 9 and short-circuitted conductor 11 are provided with the water supply and exhaust tube 15 for water cooling through supply of water. As a result, a tuning coil even in such a scale as being heated up to 160-200 deg.C by the air cooling does not exceed a temperature of 40 deg.C.