Methods of monitoring and controlling a molding process using a sensed change in strain provided by a strain gauge are provided. A target strain profile is created for a molding process of a molding apparatus. An upper and lower deviation limit from the target strain profile for the molding process is provided. If a sensed change in strain exceeds a deviation limit, an alarm is activated.

An injection molding apparatus includes a support that supports a molding die including an upper die and a lower die, and an injection unit that injects a molding material toward a cavity defined by the upper die and the lower die. In the state in which the molding die is supported by the support, the injection unit, the upper die, and the lower die are arranged sequentially from above in the vertical direction. The injection unit includes a rotating flat screw having a groove forming surface in which a groove is formed, a barrel having a flat screw facing surface facing the groove forming surface and having a communication hole into which the molding material flows, and a heater that heats a material supplied to the space between the groove forming surface and the flat screw facing surface, plasticizes at least part of the material through the rotation of the flat screw and the heat produced by the heater to produce the molding material, and delivers the molding material to the communication hole.

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.

A method for adjusting the closing force of a mold of a plastics processing machine. In order to work with an optimized closing force, the method comprises the steps of: a) in a first production cycle: Closing the mold with a nominal initial closing force and recording the mold deformation caused thereby and calculating the deformation work introduced by the mold deformation; b) in a subsequent further production cycle: Closing the mold with a reduced closing force and recording the resulting mold deformation and calculating the deformation work introduced by the mold deformation; c) Recording the determined deformation work versus the closing force, carrying out a linear extrapolation of the course of the deformation work versus the closing force and determining a reduced closing force which is at a predetermined percentage value of one of the previously determined deformation work; d) Carrying out the subsequent further production cycle with the determined reduced closing force.

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.

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.

An injection molding includes: a clamping mechanism (conversion mechanism and toggle mechanism) for moving a fixed platen that retains a fixed die toward a fixed platen that retains a fixed die to bring the fixed die and the movable die into contract, and generating a clamping force therebetween; a drive source (mold opening/closing motor) for driving the clamping mechanism; a clamping force detection unit for detecting the clamping force; an elongation value detection unit for detecting an elongation value indicating the amount of elongation of a tie bar that extends as the clamping force is generated; and an abnormality determination unit for determining an abnormality in the injection molding machine on the basis of the ratio of the elongation value and the clamping force.

An opening/closing device (14) includes: a stationary platen (20), a movable platen (22) capable of moving toward or away from the stationary platen (20), an opening/closing mechanism (28) having a plurality of toggle links (30, 31, 32) at least one (32) of which is connected to the movable platen (22); a driving device (37) including a cross head (26) connected to at least one (30) of the toggle links and capable of moving the movable platen (22), and a control portion (50). The control portion (50) is configured to control the cross head (26) such that the movable platen (22) moves at fixed speed during fine die-opening operation.

A technique for providing assistance in setting the time to increase the clamping force is provided. A control device of an injection molding machine includes a clamping control part and a monitoring part. The clamping control part is configured to change, in a filling step of filling the inside of a mold device with a molding material during clamping, a set value of clamping force from a first set value to a second set value that is larger than the first set value, at a predetermined pressurizing timing in the middle of the filling step. The monitoring part is configured to monitor changes in the actual value of the clamping force due to changes in the set value of the clamping force.

A mold-clamping device includes a fixed mold plate including a fixed mold; a movable mold plate including a movable mold; a hydraulic cylinder allowing the movable mold plate to approach or be separated from the fixed mold plate; a hydraulic pressure supply source supplying a hydraulic fluid to the hydraulic cylinder; and a control unit performing driving control on the hydraulic pressure supply source. The control unit includes a flow rate decrease control unit for deceleration for decreasing a flow rate of the hydraulic fluid according to a deceleration gradient set in advance when a movement of the movable mold plate is decelerated according to the deceleration gradient, and a flow rate increase control unit for controlling the flow rate of the hydraulic fluid to increase when the flow rate of the hydraulic fluid is decreased according to the deceleration gradient by the flow rate decrease control unit.