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.

In a mold clamping apparatus, a mold clamping mechanism is provided with a half nut, and a tie bar is provided with circumferential groove configured to meshed with the teeth of the half nut. A strong-force mold opening mechanism that opens molds at an initial stage of mold opening extends across a space separating a movable platen and the mold clamping mechanism and is connected to the movable platen and the mold clamping mechanism. The strong-force mold opening mechanism is set so as to have greater axial force and shorter stroke than those of a mold opening and closing mechanism. A control unit controls opening and closing of the half nut, controls the strong-force mold opening mechanism and controls the position of the half nut in such a way that the half nut is synchronized with the circumferential groove by the strong-force mold opening mechanism.

A brake control method for an injection molding machine includes the steps of obtaining mold clamping force information indicating the mold clamping force of a mold opening/closing mechanism and determining whether or not the mold clamping force of the mold opening/closing mechanism exceeds a predetermined value, based on the mold clamping force information. When the mold clamping force of the mold opening/closing mechanism does not exceed the predetermined value and when a servo amplifier cuts off the supply of power to a servomotor that drives the mold opening/closing mechanism, a brake mechanism for applying braking force to the mold opening/closing mechanism is actuated. On the other hand, when the mold clamping force of the mold opening/closing mechanism exceeds the predetermined value, the brake mechanism will not be actuated.

Mold clamping conditions, including a predetermined mold gap, a predetermined mold clamping force, a predetermined back pressure for a movable mold, a predetermined mold closing pressure, and a predetermined mold closing pressure adjustment condition associated with the compression state of a molding material, are set beforehand. At the time of molding, an injection filling process for causing the injection device to inject and fill the molding material into a mold of a mold clamping device for which the mold clamping conditions have been set is performed, and, after completion of the injection filling process, a compression process is performed on the basis of the mold clamping conditions including the mold closing pressure adjustment condition.

Provided is a molding machine including a mold opening/closing mechanism configured to move a movable platen to be attached with a movable mold to a stationary platen to be attached with a stationary mold, and a clamping mechanism to perform a clamping process, and is intended to suppress machine cost or ensure the mold opening/closing speed. The molding machine includes the mold opening/closing mechanism configured to move the movable platen to be attached with the movable mold to the stationary platen to be attached with the stationary mold, and the clamping mechanism configured to perform a clamping process. The mold opening/closing mechanism includes at least two ball screws, at least two electric motors that respectively drive the ball screws, and a ball screw nut into which each of the ball screws is inserted.

A power supply device for a molding machine with an intermediate circuit, which can be connected with at least one drive of the molding machine and is suitable for supplying the at least one drive with electrical energy; a supply module connected to the intermediate circuit; an energy storage device connected to the intermediate circuit; and a closed loop control device for closed loop controlling an energy content of the energy storage device. The energy storage device can be closed loop controlled by means of the closed loop control device so that the energy content of the energy storage device does not go outside a range, in which a power input and/or a power output of the energy storage device is essentially constant.

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.

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 brake control method for an injection molding machine includes the steps of obtaining mold clamping force information indicating the mold clamping force of a mold opening/closing mechanism and determining whether or not the mold clamping force of the mold opening/closing mechanism exceeds a predetermined value, based on the mold clamping force information. When the mold clamping force of the mold opening/closing mechanism does not exceed the predetermined value and when a servo amplifier cuts off the supply of power to a servomotor that drives the mold opening/closing mechanism, a brake mechanism for applying braking force to the mold opening/closing mechanism is actuated. On the other hand, when the mold clamping force of the mold opening/closing mechanism exceeds the predetermined value, the brake mechanism will not be actuated.

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.