A piston for cold chamber die-casting machines includes a piston body terminating at the front with a frontal surface pushing molten metal and at least one ring seat made around the body suitable to house a respective sealing ring. An annular distribution channel is made in an intermediate annular portion of the bottom surface of the ring seat, which communicates with the frontal surface of the piston through at least two communication holes made in the piston body for flow of molten metal into the distribution channel, under the ring. The communication holes are inclined in relation to the piston axis and have a through section which increases towards the distribution channel.

A casting plunger system for a die casting machine includes a stationary system part and a system part which moves relative to the stationary system part in a respective casting cycle for the introduction of melt material into a casting mould. The moved system part has a plunger, a plunger rod and a rod drive unit, and is configured to decelerate at the end of a mould filling phase of the casting cycle under the effect of pressure on the melt material. A casting method for a die casting machine is provided with such a plunger system. The moved system part has a mass which can be adjusted variably between different casting cycles, and/or the moved system part consists of a moved main system part and an additional mass unit which is arranged so as to be movable relative to the main system part and is configured to decelerate, at the end of the mould fill phase of the casting cycle, later by a predefined delay time than the main system part.

The invention relates to a die casting ring (1) internally fitted with radial teeth (11) to be engaged into matching seats (22) provided on a piston (2). This piston-ring assembly prevents mutual rotation or axial translation, in addition to ensuring an optimal seal against infiltration of liquid metal during the die casting process. When the ring has a cutout (10), it can be mounted accurately onto the piston because the teeth (11) allow the cutout to be positioned anywhere relative to the piston.

An injection device of a light metal injection molding machine of the disclosure includes: a melting cylinder that heats and melts a billet pushed along a cylinder hole and stores molten metal; an injection cylinder that injects, by an inserted plunger, the molten metal supplied by free fall due to the own weight from the melting cylinder through a communication path that can be opened and closed; and a molten metal pot in which a molten metal supply/discharge port connected to the melting cylinder is opened at a location in the melting cylinder that does not face an opening of the communication path on the melting cylinder side, and molten metal in an amount in excess of a capacity that can be stored in the melting cylinder is stored.

A die casting machine includes a clamping device 7 which opens and closes and clamps a pair of die halves, an injection apparatus which performs injection to the pair of die halves by making a plunger move forward in a sleeve communicated with a space between the pair of die halves, and a control device which controls the clamping device and injection apparatus. The control device includes an injection control part and press-use clamping control part. The injection control part controls the injection apparatus so as to start the injection in a state where the pair of die halves face each other through a gap. The press-use clamping control part controls the clamping device so that the die contact and clamping are carried out after the start of injection. Further, the injection control part performs control for decelerating the plunger before the plunger stops.

A device for die-casting metal material, including a screw unit for bringing the material into a thixotropic state and a cylinder/piston unit fed by the screw unit for applying pressure to the thixotropic material for the die casting, wherein a thermally controllable valve is arranged between the screw unit and the cylinder/piston unit.

A flow rate control valve configuring a meter-out circuit of an injection cylinder is an overlap type where a first port starts to be opened by a spool passing through an overlapping range. The control device holds a characteristic table linking a command value of a control command to the flow rate control valve and a velocity of a plunger including also the movement of the plunger which occurs due to a gap flow even if the spool is located in the overlapping range. Further, the control device specifies the command value corresponding to the target velocity set by operation of the input device based on the characteristic table, performs open control based on this command value, then performs the feedback control for realizing the target velocity.

A molding machine for molding material is provided. The machine includes a cavity to be filled with molten metal and a conduit system leading to the cavity, thus forming a system of interconnected hollow spaces. At least one pressure member is moveable in at least part of the conduit system. A centrifugal pump in fluid communication with a reservoir of molten metal is provided, the pump providing molten metal to the hollow space receiving the at least one pressure member.

An apparatus for injecting molten metal into a die cast machine is provided. The apparatus includes a molten metal reservoir having a first open end in fluid communication with a die casting mold and a second open end. The molten metal reservoir includes at least one first cooling fluid path positioned about at least a portion of an outer surface of the molten metal reservoir and in thermal contact with the molten metal reservoir. The apparatus further includes a plunger sized to fit within the second open end. The plunger includes a plunger tip and a second cooling fluid path defined within the plunger tip and in thermal contact with the molten metal reservoir. A plurality of thermal actuators are also provided. Each of the plurality of thermal actuators controls a volume of cooling fluid flowing through one first cooling fluid path of the at least one first cooling fluid path or the second cooling fluid path.

A hot metal supply injection method includes generating a negative pressure in a cylindrical container by a negative pressure generation device, and causing molten metal to be sucked into the cylindrical container from a retention furnace, while keeping an opening portion of the cylindrical container immersed in the molten metal, arranging the opening portion of the cylindrical container in a gate of a cavity while holding the negative pressure by closing up the opening portion of the cylindrical container after moving an inner plunger tip to a tip side of the cylindrical container, and moving the inner plunger tip to a rear end side of the cylindrical container, then moving an outer plunger tip, together with the inner plunger tip, to the tip side of the cylindrical container, and filling the interior of the cavity with the molten metal through injection via the gate.