A clamping device (14) comprises a pressure receiving platen (24), a stationary platen (20), a movable platen (22), a toggle mechanism (28), and a drive device (37). A first position detector (38a) detects the operation amount of the movable platen (22) based on the position of a crosshead (26); a pressure detector (35) detects the actual clamping force of a mold (19); and a second position detector (43) detects the actual position of the movable platen (22). A control portion (50) has first correction means correcting the operation amount of the movable platen (22) at the time of a minute mold opening operation based on the actual clamping force and on the set clamping force, and second correction means correcting the operation amount of the movable platen (22) at the time of the minute mold opening operation based on the operation amount of the movable platen (22) and on the position of the movable platen (22).

In one aspect, there is provided an injection molding system configured to operate in a plurality of cycles. The system comprises, amongst other things, a controller that is configured for performing a comparison of a variable pressure setpoint with a target pressure value. The controller is configured to, when the target pressure value is less than the variable pressure setpoint by at least a predetermined lower bound, (i) decrease the variable pressure setpoint to a reduced variable pressure setpoint and (ii) not further decrease the variable pressure setpoint from the reduced variable pressure setpoint until the pump assembly operates for a plurality of stabilizing cycles at the reduced variable pressure setpoint.

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.

A clamping device (14) comprises a pressure receiving platen (24), a stationary platen (20), a movable platen (22), a toggle mechanism (28), and a drive device (37). A first position detector (38a) detects the operation amount of the movable platen (22) based on the position of a crosshead (26); a pressure detector (35) detects the actual clamping force of a mold (19); and a second position detector (43) detects the actual position of the movable platen (22). A control portion (50) has first correction means correcting the operation amount of the movable platen (22) at the time of a minute mold opening operation based on the actual clamping force and on the set clamping force, and second correction means correcting the operation amount of the movable platen (22) at the time of the minute mold opening operation based on the operation amount of the movable platen (22) and on the position of the movable platen (22).

When an injection molding machine performs molding, the mold clamping force on the mold is adjusted on the basis of a mold displacement of the mold or the injection peak pressure and injection foremost position so that the molding is performed without causing flash and by an appropriate mold clamping force with which energy can be reduced. The amount of mold displacement and also the injection peak pressure and the injection foremost position are monitored during automatic operation. If there occurs no mold displacement change exceeding a threshold or if there occurs no injection peak pressure anomaly or injection foremost position anomaly exceeding thresholds, the automatic operation is continued. If the mold displacement change occurs or if the injection peak pressure anomaly and the injection foremost position anomaly occur, the operation of the injection molding machine is stopped.

A method and apparatus for injection molding of plastic material into a cavity of a mold by means of at least one injector whose opening and closing occurs through an electronic control unit and wherein an undesired opening of the mold caused by any overpressure of the plastic material injected into the cavity of the mold is detected by means of transducers and corrected by means of the electronic control unit. The transducers are arranged outside the cavity of the mold.

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.