Mould-closing unit for an injection moulding machine, and method for locking a force transmission element

A mold closing unit for an injection molding machine for processing plastics and other plasticisable materials, comprising

• a stationary platen, p1 a movable platen which is movable in relation to the stationary platen and which forms a mold clamping space between the movable platen and the stationary platen for the purpose of receiving injection molds, and which is movable along a closing direction, for closing and opening the injection mold,
• a mold moving device configured to move the movable platen into and out of mold closure of parts of an injection mold that is received between the platens,
• at least one force transmitting element, which is connected to one platen of the movable platen or the the stationary platen and, at its end spaced from the one platen, has an actuable portion that is associated with the other platen of the movable platen or the stationary platen and is actuable for an operative engagement,
• at least one locking device that is associated with the other platen and is movable into positive operative connection with the actuable portion when the parts of the injection mold are in a mold closure position, for the purpose of applying a closing force,
• wherein the at least one locking device comprises at least one floating collet chuck that is movable into positive operative connection with the actuable portion for the purpose of locking the at least one force transmitting element and the other platen during mold closure, and at the same time is connected to at least one piston of a piston-cylinder unit configured to apply the closing force,.
• wherein the locking device comprises at least one unlocking element that is arranged in the at least one collet chuck and a cylindrical chamber that is configured to put the unlocking element under load for the purpose of opening the collet chuck, and
• wherein when the unlocking element abuts by its end face against the tie bar, high-pressure opening of the injection mould is configured to be generated from this cylindrical chamber.