A mold closing unit for an injection molding machine for processing plastics and other plasticizable materials, comprising - a stationary mold carrier, - a mold carrier that is movable relative to the stationary mold carrier and forms, between itself and the stationary mold carrier, a mold clamping space for receiving injection molds and is movable in a closing direction (s-s) for the purpose of closing and opening the injection mold, - a mold drive device for bringing the movable mold carrier into and out of mold closure of parts of an injection mold which are received between the mold carriers (10, 11), - at least one force transmission element, which is connected to one of the mold carriers (11, 10) and has at its end spaced from the one of the mold carriers (11, 10) a portion that is associated with the other of the mold carriers (10, 11) and is actuable for the purpose of operative engagement, - at least one locking device that is associated with the other mold carrier (10, 11) and has a plurality of locking elements that are arranged radially in relation to the force transmission element and which, during mold closure of the parts of the injection mold, are configured to be brought into positively locking operative connection with the actuable portion for the purpose of applying a closing force, - wherein the locking device comprises at least one actuator that is movable in the closing direction (s-s) and on which, during movement of the actuator, the locking elements are configured to be brought into and out of positively locking operative connection with the actuable portion, transversely to the closing direction (s-s) in a forced guidance arrangement during mold closure, and - wherein at the same time the actuator is connected to at least one piston of a piston-and-cylinder unit, for the purpose of applying the closing force, characterized in that the forced guidance arrangement is a cam guide for the locking elements, which take the form of clamping jaws that are configured to be brought into operative connection with the actuable portion. - a stationary mold carrier, - a mold carrier that is movable relative to the stationary mold carrier and forms, between itself and the stationary mold carrier, a mold clamping space for receiving injection molds and is movable in a closing direction (s-s) for the purpose of closing and opening the injection mold, - a mold drive device for bringing the movable mold carrier into and out of mold closure of parts of an injection mold which are received between the mold carriers (10, 11), - at least one force transmission element, which is connected to one of the mold carriers (11, 10) and has at its end spaced from the one of the mold carriers (11, 10) a portion that is associated with the other of the mold carriers (10, 11) and is actuable for the purpose of operative engagement, - at least one locking device that is associated with the other mold carrier (10, 11) and has a plurality of locking elements that are arranged radially in relation to the force transmission element and which, during mold closure of the parts of the injection mold, are configured to be brought into positively locking operative connection with the actuable portion for the purpose of applying a closing force, - wherein the locking device comprises at least one actuator that is movable in the closing direction (s-s) and on which, during movement of the actuator, the locking elements are configured to be brought into and out of positively locking operative connection with the actuable portion, transversely to the closing direction (s-s) in a forced guidance arrangement during mold closure, and - wherein at the same time the actuator is connected to at least one piston of a piston-and-cylinder unit, for the purpose of applying the closing force,