A die casting method includes a step of supplying molten metal to a plunger sleeve, and a step of advancing a plunger in the plunger sleeve, to inject the molten metal into dies. In the step of injecting the molten metal into the dies, the plunger is once retracted before being advanced, and the plunger is kept accelerated until the plunger reaches a target maximum speed when the plunger retracted is advanced.

Disclosed are an aluminum alloy for die casting that has excellent thermal conductivity and corrosion resistance, which can be used for parts requiring heat dissipation and high corrosion resistance, and a method of producing a cast aluminum alloy using the same.

Provided is an aluminum alloy for die casting that may include an amount of about 8.5 to 10.5 wt % of silicon (Si); an amount of about 3.6 to 5.5 wt % of magnesium (Mg); an amount of about 0.3 to 1.0 wt % of iron (Fe); an amount of about 0.1 to 1.0 wt % of manganese (Mn); and the balance of aluminum (Al) and inevitable impurities, all the wt % are based on the total weight of the aluminum alloy.

A pressure intensifier device for increasing pressure in a pressurized fluid chamber of a piston/cylinder unit and a casting unit provided therewith for a diecasting machine, and also an associated operating method are provided. The pressure intensifier device has a pressure intensifier cylinder and a pressure intensifier piston, which is guided in an axially movable manner in the cylinder, wherein the pressure intensifier cylinder has an outlet region, an inlet region upstream of the outlet region and a piston guiding chamber, and the pressure intensifier piston has a piston part, which is guided in the piston guiding chamber, and a piston rod, which extends from the piston part to the inlet region, in a maximally retracted release position releases a fluid connection between the inlet region and the outlet region and, in a maximally advanced blocking position, blocks this connection with a free end portion, with which it extends into the outlet region. Over a portion that can be passed through by the free end portion of the piston rod during movement from the release position into the blocking position, the outlet region has a free passage cross section for the free piston rod end portion that is at least equal in size to a rod cross section of the free piston rod end portion. Advantageously, a pressure intensifier inlet valve can be controlled independently of a pressure in the pressurized fluid chamber of the piston/cylinder unit.

A back spray system comprising an injection piston having a plunger tip (26) and a shot rod (24) with a shot rod hole (32) drilled through the length of the rod connecting a lubricating supply to a collar (30) located right directly behind the plunger tip (24). The collar (30) has a predetermined number of collar holes (40) positioned circumferentially about the collar (30) sized and positioned to dispense a precise and uniform amount of lubricant to the space between the plunger tip (24) and the shot sleeve (20). Under the collar (30) is a channel with two drilled holes (38) connected to the shot rod hole (40).

A pressure intensifier device increases pressure in a pressurized fluid chamber of a piston/cylinder unit. The pressure intensifier device has a pressure intensifier cylinder and a pressure intensifier piston, which is guided in an axially movable manner in the cylinder, wherein the pressure intensifier cylinder has an outlet region, an inlet region upstream of the outlet region and a piston guiding chamber, and the pressure intensifier piston has a piston part, which is guided in the piston guiding chamber, and a piston rod, which extends from the piston part to the inlet region, in a maximally retracted release position releases a fluid connection between the inlet region and the outlet region and, in a maximally advanced blocking position, blocks this connection with a free end portion, with which it extends into the outlet region. Over a portion that can be passed through by the free end portion of the piston rod during movement from the release position into the blocking position, the outlet region has a free passage cross section for the free piston rod end portion that is at least equal in size to a rod cross section of the free piston rod end portion. A pressure intensifier inlet valve can be controlled independently of a pressure in the pressurized fluid chamber of the piston/cylinder unit.

A die casting machine is provided with a movable platen for holding a movable mold, a stationary platen for holding a stationary mold, and tie bars inserted into insertion holes provided in the movable platen and the stationary platen, the movable platen being arranged so as to be capable of advancing to and retreating from the fixed platen along the tie bars. A hollow section is provided in at least one of the movable platen and the stationary platen.

Provided is a die casting machine and die casting machine control method that are able to change the operation of a plunger at an appropriate timing. A die casting machine operates a plunger such that the plunger moves forward, detects that molten metal extruded from a sleeve by the forward movement of the plunger has arrived at a cavity, determines a deceleration starting position and a intensification starting position for changing the operation of the plunger, using, as a reference (reference position Ls), the position of the plunger 15 at the time when it is detected that molten metal has arrived at the cavity, and, when the plunger moves to the deceleration starting position and intensification starting position, changes the operation of the plunger to operations corresponding to the respective positions.

An injection device of light metal injection molding machine and an injection control method thereof are provided, in which a melt in a supply unit is supplied into an injection unit through a communication passage, a plunger of the injection unit is retracted to measure the melt, the communication passage is closed, and the plunger is advanced to inject the melt into a mold device through an injection nozzle of the injection unit. After the injection and before the measurement, the plunger is advanced under a pressure at which the melt does not come out from the injection nozzle to make the melt in the injection unit flow back into the supply unit through the opened communication passage.

A piston of a die-casting apparatus includes: a piston tip having a generally cup-shaped body having an inner front face and an inner cylindrical surface, the inner front face having a plurality of grooves formed therein for conveying cooling fluid; and an inner piston carrier coupled to the piston tip, the carrier comprising an elongate forward portion matingly engaging the piston tip.

A plunger tip includes a main body of the plunger tip. A first cooling chamber is provided at a central region of a tip end of the main body of the plunger tip inside the main body of the plunger tip. A second cooling chamber is provided along an outer peripheral surface of the tip end inside the main body of the plunger tip. The second cooling chamber is configured such that a cooling medium is caused to flow in the second cooling chamber in priority to the first cooling chamber.