Abstract: A coupling device of the insertion or plug-in type for connecting lines which conduct flowing media, preferably pressurized fluids, to the mold halves of a molding tool in an injection molding machine. The coupling device includes a first coupling member, for example, a coupling nipple, mounted on an adapter plate of the injection molding machine and a second coupling member, for example, a coupling sleeve, mounted on a mold half of the molding tool. A locking device is used for fixing the two coupling members in an engaged position. The locking device is biased into its locking position by means of a spring and can be moved against the biasing force by means of an electromagnet from the locking position into a releasing position.