Abstract: A hydrostatic bearing spindle device includes: a spindle includes tapered portion having tapered radial receiving surface and flange having first thrust receiving surface and second thrust receiving surface formed at rear side from first thrust receiving surface; first thrust bearing has first thrust bearing surface facing first thrust receiving surface; second thrust bearing has second thrust bearing surface facing second thrust receiving surface; radial bearing facing tapered radial receiving surface; rotation regulator regulates relative rotation of one of first thrust bearing and second thrust bearing with respect to the other; and housing has first screw groove which is screwed with first thrust bearing and second screw groove which is screwed with second thrust bearing. Second screw groove has larger screw pitch than first screw groove does when tapered portion expands rearward, and first screw groove has larger screw pitch than second screw groove does when tapered portion expands frontward.

Abstract: 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.

Abstract: A hydrostatic bearing spindle device includes: a spindle includes tapered portion having tapered radial receiving surface and flange having first thrust receiving surface and second thrust receiving surface formed at rear side from first thrust receiving surface; first thrust bearing has first thrust bearing surface facing first thrust receiving surface; second thrust bearing has second thrust bearing surface facing second thrust receiving surface; radial bearing facing tapered radial receiving surface; rotation regulator regulates relative rotation of one of first thrust bearing and second thrust bearing with respect to the other; and housing has first screw groove which is screwed with first thrust bearing and second screw groove which is screwed with second thrust bearing. Second screw groove has larger screw pitch than first screw groove does when tapered portion expands rearward, and first screw groove has larger screw pitch than second screw groove does when tapered portion expands frontward.

Abstract: An injection device of a light metal injection molding machine includes: a first inert gas storage part creating an inert gas atmosphere around a plunger insertion portion of an injection cylinder; a second inert gas storage part housing surplus molten metal in a melting cylinder and creating an inert gas atmosphere above the molten metal; and a first pressure adjustment part adjusting a pressure in the first inert gas storage part to a pressure equal to or less than a pressure obtained by adding a pressure, which is determined based on a value obtained by multiplying a specific gravity of the molten metal by a height difference between a highest position and a lowest position of the molten metal in a part that includes the inside of the injection cylinder and communicates with the inside of the injection cylinder, and a pressure in the second inert gas storage part.

Abstract: A light metal injection molding machine includes an injection cylinder, a seal cylinder, a plunger, and a seal mechanism having a first annular body, a second annular body and a third annular body. The first annular body is arranged in an opening of the seal cylinder, and maintains a semisolid state of a molding material in a first gap between its inner periphery surface and the plunger. The second annular body is arranged in the opening between the injection cylinder and the first annular body, and includes an anterior internal groove formed over its whole inner periphery surface and a plurality of anterior transverse holes passing through the inner periphery surface. The third annular body is accommodated into the anterior internal groove transformably in a radial direction of the plunger, and tighten the plunger by pressurization from molding material flowing into the anterior transverse holes.

Abstract: A light metal injection molding machine includes a melting unit, a material supply device, and an inert gas supplier. The material supply device includes a supply cylinder and a lower shutter. The supply cylinder includes a passage which communicates vertically, a supply opening disposed on an upper side of the passage and to which a molding material is fed, and a discharge opening which is disposed on a lower side of the passage and discharges the molding material to a material supply port of the melting unit. The lower shutter is disposed in the supply cylinder to open and close the passage, and the molding material is placed on the lower shutter when the passage is closed. The lower shutter has at least one vent-hole that allows an inert gas supplied from below the lower shutter to pass when the passage is closed.

Abstract: There is provided an injection molding machine that includes a melting device in which a molding material melts to generate a molten material; an injection device from which the molten material supplied from the melting device is injected; and a connecting member including a communication path communicating with the melting device and the injection device. The melting device includes a material supply port to which the molding material is supplied, a partition plate that partitions the inside excluding at least both ends of the melting device and extends from the side of the material supply port to the side of the communication path, and a stirrer configured to stir the molten material in a manner of circulating around the partition plate.

Abstract: There is provided a melting device including a melting cylinder that is heated to a predetermined temperature, melts a molding material supplied from a material supply port, and generates a molten material; an inert gas supply device configured to supply an inert gas onto a melting surface of the molten material and form an inert gas layer; and a low specific gravity gas supply device configured to supply a low specific gravity gas which is a gas having a different type from the inert gas and form a low specific gravity gas layer on the inert gas layer, wherein the low specific gravity gas layer has a lower specific gravity than the inert gas layer.

Abstract: 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.

Abstract: There is provided an injection molding machine including a backflow prevention device configured to perform a backflow prevention operation in which the communication path is closed to prevent a backflow of the molten material. The backflow prevention device includes a sealing seat that is provided in the communication path, a valve rod that is movable to come in contact with the sealing seat, and a fitting portion in which the sealing seat as an end is fitted to the valve rod. The backflow prevention operation includes at least one pumping operation in which a front of the valve rod moves from a position at which the front is not fitted to the fitting portion to a position at which the front comes in contact with the sealing seat.

Abstract: An injection device of a light metal injection molding machine includes: a first inert gas storage part creating an inert gas atmosphere around a plunger insertion port of an injection cylinder; a second inert gas storage part housing surplus molten metal in a melting cylinder and creating an inert gas atmosphere above the molten metal; and a first pressure adjustment part adjusting a pressure in the first inert gas storage part to a pressure equal to or less than a pressure obtained by adding a pressure, which is determined based on a value obtained by multiplying a specific gravity of the molten metal by a height difference between a highest position and a lowest position of the molten metal in a part that includes the inside of the injection cylinder and communicates with the inside of the injection cylinder, and a pressure in the second inert gas storage part.

Abstract: A light metal injection molding machine includes a melting unit, a material supply device, and an inert gas supplier. The material supply device includes a supply cylinder and a lower shutter. The supply cylinder includes a passage which communicates vertically, a supply opening disposed on an upper side of the passage and to which a molding material is fed, and a discharge opening which is disposed on a lower side of the passage and discharges the molding material to a material supply port of the melting unit. The lower shutter is disposed in the supply cylinder to open and close the passage, and the molding material is placed on the lower shutter when the passage is closed. The lower shutter has at least one vent-hole that allows an inert gas supplied from below the lower shutter to pass when the passage is closed.

Abstract: A light metal injection molding machine includes an injection cylinder, a seal cylinder, a plunger, and a seal mechanism having a first annular body, a second annular body and a third annular body. The first annular body is arranged in an opening of the seal cylinder, and maintains a semisolid state of a molding material in a first gap between its inner periphery surface and the plunger. The second annular body is arranged in the opening between the injection cylinder and the first annular body, and includes an anterior internal groove formed over its whole inner periphery surface and a plurality of anterior transverse holes passing through the inner periphery surface. The third annular body is accommodated into the anterior internal groove transformably in a radical direction of the plunger, and tighten the plunger by pressurization from molding material flowing into the anterior transverse holes.

Abstract: There is provided an injection molding machine including a backflow prevention device configured to perform a backflow prevention operation in which the communication path is closed to prevent a backflow of the molten material. The backflow prevention device includes a sealing seat that is provided in the communication path, a valve rod that is movable to come in contact with the sealing seat, and a fitting portion in which the sealing seat as an end is fitted to the valve rod. The backflow prevention operation includes at least one pumping operation in which a front of the valve rod moves from a position at which the front is not fitted to the fitting portion to a position at which the front comes in contact with the sealing seat.

Abstract: There is provided a melting device including a melting cylinder that is heated to a predetermined temperature, melts a molding material supplied from a material supply port, and generates a molten material; an inert gas supply device configured to supply an inert gas onto a melting surface of the molten material and form an inert gas layer; and a low specific gravity gas supply device configured to supply a low specific gravity gas which is a gas having a different type from the inert gas and form a low specific gravity gas layer on the inert gas layer, wherein the low specific gravity gas layer has a lower specific gravity than the inert gas layer.

Abstract: There is provided an injection molding machine that includes a melting device in which a molding material melts to generate a molten material; an injection device from which the molten material supplied from the melting device is injected; and a connecting member including a communication path communicating with the melting device and the injection device. The melting device includes a material supply port to which the molding material is supplied, a partition plate that partitions the inside excluding at least both ends of the melting device and extends from the side of the material supply port to the side of the communication path, and a stirrer configured to stir the molten material in a manner of circulating around the partition plate.

Abstract: An injection apparatus in a cold chamber die casting molding machine, where a melting device of the injection apparatus includes a billet supplying device for replenishing a light metal material in the form of a billet, a melting cylinder for melting the billet from its front end and forming a molten metal for several shots, an inserting device for inserting a billet into the melting cylinder, and a plunger injection device. The amount of a molten metal for one shot is measured via an opening and shutting device of a molten metal feeding member and is fed from the melting device to the plunger injection device. In particular, the sealing of the molten metal in the melting cylinder is achieved by the contact of the side surface of a portion of the billet having an enlarged diameter with the hole of the cylinder, or by the contact of a circular solidified material formed in a circular groove in a cooling sleeve with the billet.

Abstract: An injection device for a light metal injection molding machine includes a melting device for melting light metal material into molten metal, plunger injection device for carrying out injection of molten metal using a plunger after the molten metal is metered into an injection cylinder from the melting device, connecting member including a connecting passage for connecting the melting device and the plunger injection device, and backflow prevention device for preventing backflow of molten metal by opening and closing the connecting passage.

Abstract: An injection apparatus in a cold chamber die casting molding machine, where a melting device of the injection apparatus includes a billet supplying device for replenishing a light metal material in the form of a billet, a melting cylinder for melting the billet from its front end and forming a molten metal for several shots, an inserting device for inserting a billet into the melting cylinder, and a plunger injection. The amount of a molten metal for one shot is measured via an opening and shutting device of a molten metal feeding member and is fed from the melting device to the plunger injection device. In particular, the sealing of the molten metal in the melting cylinder is achieved by the contact of the side surface of a portion of the billet having an enlarged diameter with the hole of the cylinder, or by the contact of a circular solidified material formed in a circular groove in a cooling sleeve with the billet.

Abstract: An injection device for a light metal injection molding machine includes a melting device for melting light metal material into molten metal, plunger injection device for carrying out injection of molten metal using a plunger after the molten metal is metered into an injection cylinder from the melting device, connecting member including a connecting passage for connecting the melting device and the plunger injection device, and backflow prevention device for preventing backflow of molten metal by opening and closing the connecting passage.