Double closing unit of an injection molding machine has a pair of movable mold mounting plates and a stationary mold mounting plate having a pair of stationary mold faces, aligned between the pair of movable mold mounting plates. Two pairs of bar members and a pair of locking units are provided so that each locking unit couples one of the pair of movable mold mounting plates to one of the pairs of bar members. A pair of pressure cushion systems located in the stationary mold mounting plate are each connected to one of the pair of movable mold mounting plates, the pair of pressure cushion systems being independent of each other. At least one pair of fast-motion cylinders is also provided, at least one cylinder being connected between each movable mold mounting plate and the stationary mold mounting plate. The cylinders hold one of the movable mold mounting plates in a closed position when the other movable mold mounting plate is in an open position.