A specific mold status Ac is caused in advance in which the interval of an inner portion Xi in the parting plane direction of a parting gap C between a fixed mold 2c and a movable mold 2m during the injection filling is larger than the interval of an outer edge portion Xo and the interval of the outer edge portion Xo is equal to or lower than a predetermined size Ls including 0. A molding injection pressure Pi is set as an injection pressure at which a non-defective product can be molded and a molding mold clamping force Pc is set as a mold clamping force by which a non-defective product can be molded. During the production, a mold 2 is clamped by a molding mold clamping force Pc and the clamped mold 2 is filled with the injected resin R by a molding injection pressure Pi. After a predetermined cooling time Tc has passed, a molded piece G is removed.

A time Gt from the start of an injection step until a mold clamping operation is complete is compared with an operation time Ct for a mold clamping step. For Gt<Ct, the injection step is started when a time Dt equal to a difference between Gt and Ct elapses. On the other hand, for Gt≧Ct, after the start of the injection step, a movable platen is stopped at a mold touch position until the time Dt elapses. When the time Dt elapses, the mold clamping step is started.

An injection molding machine is provided that includes a clamping force sensor that detects a clamping force of a mold, and a clamping force monitoring unit that monitors a detected value of the clamping force sensor and calculates a first mold open distance and/or a second mold open distance. The first mold open distance is calculated based on the difference between the maximum value of the detected values obtained during an injection process and a pressure holding process and the detected value obtained at the start of the injection process. The second mold open distance that is calculated based on the difference between the detected value obtained at the end of the pressure holding process and the detected value obtained at the start of the injection process.

A monitoring apparatus for molds includes a control unit connectable to a first and second sensor associable with the mold and configured for emitting respective signals representative of a deformation parameter and temperature parameter of the mold. The control unit, in order to define an alert condition, is configured for: defining a value of a threshold parameter as a function of the temperature of the mold and comparing such value of the deformation parameter with a value of a threshold parameter defined as a function of the temperature of the mold; or normalizing, at a reference temperature, the value of the deformation parameter determined at the temperature of the mold and comparing a value of a threshold parameter, defined at the reference temperature, with the value of the normalized deformation parameter at the same reference temperature. Also forming the object of the present invention is a monitoring method and a data medium.

A specific mold status Ac is caused in advance in which the interval of an inner portion Xi in the parting plane direction of a parting gap C between a fixed mold 2c and a movable mold 2m during the injection filling is larger than the interval of an outer edge portion Xo and the interval of the outer edge portion Xo is equal to or lower than a predetermined size Ls including 0. A molding injection pressure Pi is set as an injection pressure at which a non-defective product can be molded and a molding mold clamping force Pc is set as a mold clamping force by which a non-defective product can be molded. During the production, a mold 2 is clamped by a molding mold clamping force Pc and the clamped mold 2 is filled with the injected resin R by a molding injection pressure Pi. After a predetermined cooling time Tc has passed, a molded piece G is removed.

An operation screen of a magnet clamp is displayed on a controller of an injection molding machine. A mold clamping device of the injection molding machine is provided with the magnet clamp. The operation screen is for controlling the magnet clamp to perform clamping or unclamping of a mold.

A technique for suppressing molding defects is provided. A control device of an injection molding machine includes: a mold clamping control unit that controls, with respect to an actual value of a mold clamping force for pressing a stationary mold and a movable mold after pressurizing of the mold clamping force is completed and before a molding material reaches parting surfaces of the stationary mold and the movable mold, a range of increase in the actual value of the mold clamping force after the molding material reaches the parting surfaces to an upper limit or less.

To provide a new foam molding method and injection molding machine capable of solving variation in a wall thickness and a foamed state, sensor corrosion, a complexity of sensor positioning, and the like. The above-described problem is solved by a foam molding method comprising a resin filling step of filling a mold (2), clamped by a predetermined mold clamping force (Pc), with a resin (R) at a predetermined molding injection pressure (Pi), a filling stopping step of stopping the filling of the resin (R) when, while monitoring a mold gap (Lm) of the mold (2) during the filling, a predetermined mold gap value set in advance is reached, a surface layer curing and filled resin cooling step of curing a surface layer of the resin (R) for a certain time and cooling the filled resin (R) for a certain time after the filling of the resin (R) is stopped, a volume controlling step of controlling a volume increase by reducing the mold clamping force after curing the surface layer of the resin (R) for a certain time, and a taking out step of taking out a foam-molded product by opening the mold (2) after the volume control is performed and after cooling the filled resin (R) for a certain time.

In an injection molding machine that transmits driving force of a mold opening/closing servo motor to a movable platen via a ball screw to move the movable platen with respect to a stationary platen, and thereafter clamps molds by a mold clamping mechanism, provided is a control method capable of detecting a position of the movable platen at a time of continuous molding and correcting the operation start confirming position. In a method for controlling an injection molding machine that transmits driving force of a mold opening/closing servo motor to a movable platen via a ball screw to move the movable platen with respect to a stationary platen, and thereafter clamps molds by a mold clamping mechanism, other control is performed using a position A of the movable platen, the position A being detected by a position sensor at a time of continuous molding, and the position A of the movable platen is corrected.

A method of monitoring and controlling a molding clamping apparatus in an injection molding or other molding process is disclosed. The method includes creating a target strain profile, receiving a deviation limit, receiving a change in strain relating to a mold while it is closing from a first strain gauge, identifying a deviation from a target strain profile based on the output from the first strain gauge, determining that the deviation exceeds the deviation limit, and adjusting the rate or force of clamp movement. The target strain profile may have a first portion relating to a clamp closing process, a second portion relating to a filling process, and a third portion relating to a clamp opening process. The first portion relating to the clamp closing process may include an intermediate portion relating to a coining process having an intermediate clamp force setpoint.