Abstract: A diecasting machine capable of realizing highly precise injection of molten metal at high-speed without using an accumulator is provided, which includes: an injection cylinder for loading molten metal into a mold cavity by injection; a single two-way hydraulic pump driven by a driving motor for supplying hydraulic fluid to the injection cylinder in two directions; a hydraulic circuit for driving the injection cylinder by controlling supply of hydraulic fluid from the two-way hydraulic pump to the injection cylinder and discharge of hydraulic fluid from the injection cylinder which proceeds in accordance with movement of a piston of the injection cylinder; and a hydraulic controller for controlling rotational speed of the driving motor associated with the two-way hydraulic pump in injection/loading the molten metal and controlling torque of the driving motor in dwelling.

Abstract: A direct-acting type diecasting machine having an inexpensive and simplified hydraulic circuit is provided, which includes: a mold clamping cylinder for clamping and opening/closing a mold in a direct-acting manner; a single two-way hydraulic pump driven by a driving motor for supplying hydraulic fluid to the mold clamping cylinder in two directions; a hydraulic circuit for driving the mold clamping cylinder by controlling supply of hydraulic fluid from the two-way hydraulic pump to the mold clamping cylinder and discharge of hydraulic fluid from the mold clamping cylinder which proceeds in accordance with movement of a piston of the mold clamping cylinder; and a hydraulic controller for controlling rotational speed of the driving motor associated with the two-way hydraulic pump in opening/closing the mold at high speed and controlling torque of the driving motor in clamping the mold.

Abstract: A method of controlling a compression injection molding machine having a movable die mounted on a movable die plate including using a pressure sensor to detect a reaction force produced at the movable die by resin being injected into a die cavity. The pressure sensor is positioned between the movable die plate and a housing supporting a toggle driving mechanism that moves the movable die plate and movable die. The output of the sensor is applied to control the injection of the resin into the die cavity or the thickness of the resin. This output can also control gate cutting or resin injection speed.

Abstract: An injection molding machine using a two-disk forming mold, in which two disk substrates molded simultaneously are made uniform without unbalance in weight. The injection molding machine uses a two-disk forming mold. The mold includes two disk molding cavities independent of each other, and resin inlets provided correspondingly to the cavities respectively. In the injection molding machine, molten resin is simultaneously injected and charged into the two cavities respectively by two plasticizing/injecting units independent of each other. The operations of the two plasticizing/injecting units are controlled to make the molten resin uniform to be charged into the two cavities.

Abstract: A precision injection molding apparatus is provided with servo mechanisms in various portions of the apparatus including a resin injection portion to provide precise feedback control of resin weighing, blending, and injection of weighed and blended resin into a die cavity between closed dies, a die opening and closing portion to provide precise feedback control for driving a movable die from a spaced position into a closed position relative to a fixed die to provide the die cavity, a gate cutting portion to provide precise feedback control of gate cutting, a molding ejecting portion to provide precise feedback control of ejecting a formed molding and a molding removing portion to provide precise feedback control for removing the molding from between opened dies. Because servo mechanisms are used, there is no variation in repetitive response accuracy of motion and speed of operation can be increased in terms of cycle speeds without loss of accuracy.

Abstract: In an injection unit of an in-line screw type injection molding machine, a screw is provided rotatably in both normal and reverse directions within a heating cylinder. The screw is periodically reversed in a charging stroke with the period of normal rotation being longer than that of reverse rotation, whereby a resin material is kneaded and plasticized. As a result, the resin in a melting and pooling zone (flow zone) between the inner wall of the heating cylinder and the outer peripheral wall of the screw is effectively moved back and forth and hence plasticized and molten into a uniform molten resin.

Abstract: A method controlling the injection of a molten resin through an in-line screw type injection molding machine. The molding machine is equipped with a check ring for permitting the injection of the molten resin by an advancement of the screw and also for preventing the molten resin from flowing backward. According to the method, the screw is rotated in the normal direction to knead and plasticize a resin material and further to feed the resultant molten resin to the free end portion of the screw. The screw then retracts to meter and store a predetermined quantity of the molten resin adjacent to the free end portion of the screw. The screw is next rotated in the reverse direction to pressure of the molten resin on the rear side of the check ring lower than that of the molten resin thus metered and stored on the front side of the check ring. The screw retracts to reduce the pressure of the resin on the front side of the check ring, thereby performing a decompression stroke.

Abstract: In a toggle-type mold-clamping apparatus including at least a pair of swingable arms and toggle pins for connecting the arms in a swingable manner through toggle bushings each of which is constructed of a cylinder element and pellets embedded in a peripheral surface of the cylinder element at intervals of a certain distance so as to be exposed to an inner peripheral surface of the cylinder element, while a lubricant film of a grease mixed with fine particles of solid lubricant is applied to sliding surfaces of the toggle pins and the toggle bushings, resulting in excellent lubrication being realized in the apparatus.