Abstract: This invention relates to an electromagnetic molten metal supply system in a die cast machine and so forth, in which an electromagnetic pump is immersed in a furnace for maintaining molten metal, and the supply tube of the pump is connected to an injection cylinder. The electromagnetic pump is provided with two groups of coils, one of which is for maintaining the molten metal and the other group of coils for supplying the molten metal, and these two coils are controlled separately.

Abstract: When molten metal within a molten metal tank is supplied to an injection sleeve of a casting machine through a molten-metal supply pipe by the operation of an electromagnetic pump, a sensor detects changes in height of the surface of molten metal within the tank as time passes, and a controller corrects the period during which the pump is driven on the basis of molten-metal surface detection signals from the sensor. The controller divides the difference in height of the surface of molten metal within the tank as between its highest level and its lowest level into a number n of regions, and drives the pump in such a controlled manner that the pump is connected to a three phase AC power source and is intermittently supplied with three-phase power having a constant voltage and a constant frequency so that the pump controls the molten-metal supply amount with its driven period serving as a molten-metal supply period.

Abstract: In a casting apparatus, an electromagnetic pump is installed above a mold cavity. A molten metal contained in a crucible is forced into the mold cavity. The electromagnetic pump acts not only to exhaust gas or air in the mold cavity but also applies a downward force to the molten metal rising above the upper surface of the mold cavity.

Abstract: In apparatus for supplying molten metal to an injection sleeve of a die cast machine from a pot containing the molten metal through a metal supply pipe, an electromagnetic pump is provided including an electromagnetic coil surrounding the molten metal supply pipe and a magnetic core inserted into the molten metal supply pipe from inside of the pot. The inner surface of the molten metal supply pipe is coated with a ceramic layer formed by centrifugal thermit method.

Abstract: In an electromagnetic pump of the type including concentric outer and inner conduits for defining a passage for molten metal, an exciting coil surrounding the outer conduit, and a magnetic core contained in the inner conduit, a cartridge electric heater is inserted into the inner conduit for preventing temperature drop of the molten metal supplied to a casting machine, for example. The electric heater may be disposed in series with the magnetic core or may be inserted into a cylindrical magnetic core.

Abstract: In a method and system of controlling an injection molding machine in which molten metal in an injection cylinder is injected into a metal mold by an injection plunger operated by an oil pressure operator and in which pressurized oil is supplied to the oil pressure operator through adjustable valve means actuated by actuator means, various factors relating to an injection condition are measured and an injection command signal is calculated based on the measured factors for providing a predetermined injection pattern. The actuator means is operated by the injection command signal so as to adjust the adjustable valve means to a degree of opening necessary to establish an optimum injection condition.

Abstract: A surface of a linear magnetic bar is subjected to such high density energy as a fine beam of laser rays, electrons, ions, plasma or an electric current to change permeability of portions subjected to the high density energy so as to form graduations spaced uniformly. A magnetic sensor is used to detect variation in the permeability, thus measuring movement, speed or acceleration of the scale relative to the magnetic sensor. The scale may be formed on a movable portion of a machine, for example a piston rod of a die casting machine or an injection molding machine.

Abstract: In apparatus for measuring injection speed of an injection molding machine having a piston rod reciprocated by an injection cylinder of the injection molding machine, a plunger rod having, at an end thereof, a plunger tip slidably received in a plunger sleeve connected to a die, and a plunger coupling for interconnecting the plunger rod and the piston rod, the plunger coupling is provided with a projection. A proximity switch detects the projection while the plunger coupling moves. In accordance with the output of the proximity switch, the speed of the plunger coupling is computed.

Abstract: Apparatus for measuring injection speeds of a die casting machine comprises a detecting device for detecting injection times at low and high speed injection strokes, calculating elements for calculating low and high injection speeds by dividing the low and high injection strokes by the injection times, and displaying elements for displaying the low and high injection speeds as average injection speeds. The injection time detecting device includes an elongated member having different magnetic characteristics, an element responsive to the characteristics to generate pulse signal, low and high speed injection limit switches, and a discriminating element for discriminating the period of the signal generated by the pulse signal generating element. The injection speeds of the die casting machine can be measured and displayed by the interrelative operations of the elements and devices described above.