Abstract: The invention has an object to permit to mold metal molds having a thixothropic structure by melting, agitating and weighing, injection molten metal in a melting vessel by combining separately functioning agitation means and injection means. The invention consists in supply granular metal material in a fusion vessel 11 having a weighing chamber 17 by a cylinder of required length communicating with a nozzle port at the extremity section, including rotatively an agitation means 21 inside, and wherein an injection means 22 whose extremity section is formed into an injection plunger 30 is inserted advanceably and retractably into the center section of this agitation means 21. The metal material is heat melted by an external heat. The molten metal material is accumulated in the fusion vessel by homogenizing by the agitation means 21.

Abstract: Upward variations of a molten metal level in a container for melting metallic material shall be carried out by detecting variations of a liquid level inside a detector connected to a gas-pipeline, wherein a rise in the pipeline pressure causes the liquid level to move down. Communication is established by means of a gas-pipeline 13 for inert gas between that portion of a container for melting metallic material which is above a molten metal surface 15a and that portion of a detector 16 comprising a transparent tubular container 18 which is above a liquid surface 17a. Variations of the liquid level 17a inside the detector 16 due to a rise in the pressure inside the above-mentioned gas-pipeline 13 are detected as upward variations of the level of the molten metal surface.

Abstract: A hydraulic circuit of an injection molding machine includes a 4-port servo valve having A, B, P, and T ports and adapted to drive and control an injection cylinder. The A and B ports are connected respectively to the front and rear oil chambers of the injection cylinder. The P port is connected to a hydraulic power unit. The T port is connected to an oil tank via a shutoff valve for selecting a regular mode or a differential mode. The T port is connected to the rear oil chamber via the logic valve. Alternatively, the rear oil chamber is connected to a hydraulic power unit side via the servo valve; the front oil chamber is connected to an oil tank via the shutoff valve; and the front oil chamber is connected to the P port of the servo valve via the logic valve. The above configuration eliminates or simplifies an additional braking circuit. Also, proper and accurate braking control can be performed.

Abstract: An injection molding screw is provided to prevent the materials from being left, and reduce the friction of the screw rotation and sliding only by limiting the end position of the screw flight to a certain position according to the position of the feeding opening in the heating cylinder. A screw 16 is rotationally and movably provided in a heating cylinder 10 having a nozzle at a tip end thereof. Granular metals fed from a feeding opening 13 at the rear of the heating cylinder are transferred forward by the screw rotation and melted. Melted metals metered in the end of the heating cylinder 10 are injected from the nozzle 11 by the forward movement of the screw. A rear end 19a of a screw flight 19 formed around the axis of the screw 16 is positioned below the rear edge of the feeding opening 13 at the rearmost position of the screw.

Abstract: An injection apparatus for melted metals is provided to be capable of transferring the metals, melting them by the external heat, metering and degassing by employing a reservoir to reserve metals in liquid phase for the injection screw. The injection apparatus comprises a heating cylinder having a fore end portion which communicates with a nozzle member and of which internal diameter is made smaller to serve as a metering chamber, and an injection screw installed within the heating cylinder to be movable and rotational. A tip end of the injection screw is formed in a plunger having a diameter that can insert into the metering chamber with keeping a clearance for sliding. A reservoir, for reserving melted metals in liquid phase, consisting of an axis is provided between the plunger and a feeding portion containing screw flight around the axis.

Abstract: Low-melting point metallic material is designed to be able to melt with an inclined melting cylinder installed in the condition of combining an injection member with an agitating member therein, and a molten metal is designed to be able to weigh and inject by a plunger, whereby molding accuracy and efficiency can be improved more than a die-cast. A injection mechanism 2 is constituted by a melting cylinder 11 which a weighing chamber 17 communicating with a nozzle member 15 is provided on the inside of the tip, agitating and injection means provided in the combined condition in the melting cylinder so as to rotate or, advance or retreat freely and a device driving agitating and injection means, which is arranged on an rear-end side of the melting cylinder. The injection mechanism 2 is provided obliquely in a manner that a nozzle member side is directed in a downward direction to a mold-clamping mechanism 1.

Abstract: A mold clamping method for a straight hydraulic mold clamping apparatus, wherein supply of mold clamping oil to the rear oil chamber of the mold clamping cylinder starts immediately before completion of slowing down of the mold closing process using rapid-moving cylinders, and raising the mold clamping force successively starts simultaneously with completion of the mold closing.