During Feeding Of Metal To Mold Patents (Class 164/457)
  • Patent number: 6186219
    Abstract: A control system and method for controlling a low-pressure die casting machine wherein the pressure within the dies more accurately tracks the desired recipe pressure. The control system senses pressure in the dies and compares the sensed pressure to desired pressure. Should the difference between the sensed pressure and the desired pressure be indicative of a problem in the casting operation, subsequent casting cycles are prevented. Should the difference between the sensed pressure and the desired pressure be indicative of a potential catastrophic failure, the current casting cycle is immediately terminated, thereby minimizing the possibility of catastrophic failure. The control system has commercially available and easily replaceable components and, thus, can be quickly repaired to reduce machine downtime should any component fail.
    Type: Grant
    Filed: April 20, 1999
    Date of Patent: February 13, 2001
    Assignee: Honda of America Mfg., Inc.
    Inventor: Richard D. Zimmerman, II
  • Patent number: 6176294
    Abstract: After a cavity 2 of a die-casting mold 1 is evacuated to exclude gases, oxygen gas is blown into the cavity 2 until an internal pressure of the cavity exceeds the atmospheric pressure, and then a molten metal 5 is forcibly injected into the cavity 2. The cavity 2 is evacuated to a degree of vacuum less than 100 millibar through a suction nozzle 11. The oxygen gas is blown through a nozzle 14 into the cavity 2 so as to fill the cavity 2 with the oxygen gas at an internal pressure higher than the atmospheric pressure. When the molten metal 5 is injected into the cavity 2 clarified in this way, inclusion of gases is perfectly prohibited. As a result, obtained die-cast products are free from defects such as blowholes or porosity caused by inclusion of gases and so useful as functional members as well as structural members.
    Type: Grant
    Filed: July 13, 1999
    Date of Patent: January 23, 2001
    Assignee: Nippon Light Metal Co., Ltd.
    Inventors: Yukio Kuramasu, Takaaki Ikari
  • Patent number: 6148898
    Abstract: A pouring method and a pouring plant are described. Mould sections (15) are produced piecewise with cavities at two opposite ends thereof. The mold sections are combined in a line (15A-15D), wherein the cavities define a mold cavity (15a) having an exposed pour cup (30). The line of mold sections is advanced incrementally by drive means (16, 162) through an increment length that corresponds to the length of the mold sections (15), to and through a molding station (50). The true lengths of the produced sections (15) are measured and registered. The difference in length between the first mold section (15D) in the line (15A-15D) that lies immediately upstream of a pour cup (30), where a pouring operation was last carried out, and the last mold section (15A) in the line is calculated.
    Type: Grant
    Filed: June 1, 1998
    Date of Patent: November 21, 2000
    Assignee: Selcom AB
    Inventors: Eric Sjodahl, Soren Nilsson
  • Patent number: 6148902
    Abstract: A vacuum die casting system has three die casting machines connected to a single vacuum system, all of which is controlled by a programmable logic controller. The controller allows any two of the machines to be operatively connected to the vacuum system so that the casting operation of those two machines are performed under vacuum. The controller comprises six address relays, a sixteen channel input card, a processor, a sixteen channel output card, an interface and two high speed counter cards. The result is an efficient, reliable, and economical vacuum die casting system.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: November 21, 2000
    Assignee: Outboard Marine Corporation
    Inventors: Michael D. Zielinski, Edward M. Nelson, Walter H. Yelczyn, David M. Regenauer
  • Patent number: 6125918
    Abstract: The invention relates to a method for measuring the amount of liquid metal contained in a tiltable casting furnace. A reference curve is established for the amount of metal contained in the furnace and the tilt angle of the furnace. This reference curve is established by first calculating a theoretical curve based on the geometry of the furnace and then correcting the theoretical curve based on the volume of metal used between one tilt angle and a greater tilt angle. The amount of metal contained in the furnace is read from the reference curve after the curve has been corrected for any deviation between actual metal level and reference metal level.
    Type: Grant
    Filed: February 25, 1998
    Date of Patent: October 3, 2000
    Assignee: Industriell Informasjonsteknologi AS
    Inventor: Arnulf Berge
  • Patent number: 6082438
    Abstract: A vacuum valve control system for a vacuum die casting machine that controls the opening and closing of a vacuum valve. The system comprises an input device for entering certain values, a detecting device for determining the position and speed of an injection plunger, a processor to calculate when the injection plunger has reached particular values for position and speed and a control device for opening and closing the vacuum valve when the particular values have been reached. The processor includes two counting devices, one to calculate the position of the injection plunger and one to calculate the speed of the plunger. The control device includes solid state relays which energize a solenoid to open the vacuum valve when the plunger has reached a certain position. The solid state relays also deenergize the solenoid to close the vacuum valve when either another particular position of the plunger has been reached or when the plunger is approaching a certain speed.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: July 4, 2000
    Assignee: Outboard Marine Corporation
    Inventors: Michael D. Zielinski, Edward M. Nelson
  • Patent number: 6026995
    Abstract: An apparatus for producing thin solidified alloy pieces having a container 53 for accommodating an alloy melt 57, the container having an opening in an upper portion of the container, drive means 2 for titling the container for providing a flow of the alloy melt from the container, control means 4 for controlling the drive means, a cooling roll 55 for cooling and solidifying the alloy melt from the container into thin pieces, and flow stabilizing means 54 for guiding the alloy melt from the container onto the cooling roll in a substantially constant flow, wherein the control means includes memory means for storing tilting angular velocity commands for tilting the container, and commanding means for reading the tilting angular velocity commands in the memory means and for activating the drive means in accordance with the commands so read, wherein the tilting angular velocity commands in the memory means have been pre-set based on theoretical quantity of the alloy melt remaining in the container at each of a pl
    Type: Grant
    Filed: July 24, 1998
    Date of Patent: February 22, 2000
    Assignee: Santoku Metal Industry Company, Ltd.
    Inventors: Kazuhiko Yamamoto, Takayuki Shibamoto, Yasuhiko Nakamura, Yasuki Mitsushima, Shigezi Sasaki
  • Patent number: 5993704
    Abstract: For exactly determining the switchover point when producing plastic injection mouldings, two pressure sensors are arranged successively at intervals in the flow direction of the inflowing material, so that the material reaches them at different points in time, and pressure curves (p.sub.1, p.sub.2) are recorded inside the mould cavity. From the measured pressures, the differential pressure is derived. When passing from volumetric filing to compression, the pressures in the mould cavity (p.sub.1, p.sub.2) undergo an abrupt rise (U1, U2). This is reflected in a steep drop of the differential pressure formed, its gradient experiencing a change of sign (V). This indicates that the switchover point has been reached, at which the filling phase must give way to the holding pressure phase.
    Type: Grant
    Filed: March 31, 1998
    Date of Patent: November 30, 1999
    Assignee: K.K. Holding AG
    Inventor: Christopherus Bader
  • Patent number: 5988260
    Abstract: A method for controlling injection in a die casting machine and apparatus for the same capable of producing high-quality die-casting products, which are not produced with fins, even in a high-speed cast or the use of the die with a low precision. A pressurizing controllable valve (21) is a flow adjustable type. A main spool (211) is structured to have a two-way valve (212) with a check-valve function and a position detector (213) for controlling servo, so that the flow of hydraulic fluid charged to a pressurizing cylinder device 20 is not controlled to be switched between ON-OFF but is allowed to adjustably flow, and a pressurizing process is controlled in response to a fin critical curve, thereby fins are previously avoided to be produced, thus producing the high-quality die-casting productions.
    Type: Grant
    Filed: March 5, 1997
    Date of Patent: November 23, 1999
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Norihiro Iwamoto, Hiroshi Kitamura
  • Patent number: 5957192
    Abstract: A method and an apparatus for controlling an injection of a die-casting machine, the apparatus having an open-shut valve for opening and shutting a hydraulic channel through which hydraulic fluid is discharged from a boost cylinder device and a boost cylinder flow-control valve for regulating a flow of the hydraulic fluid discharged from the boost cylinder device. When a highly viscous molten material is injected toward a casting mold and the molten material reaches a gate of the casting mold, an injection resistance is increased. At this time, by regulating the hydraulic channel with the control valves to discharge the hydraulic fluid in accordance with a predetermined program, the boost cylinder device applies further pressure to the injecting piston to assist injection process, thereby preventing inappropriate change in injection speed. Consequently, the open-shut valve is opened to conduct ordinary pressure boosting pressure process.
    Type: Grant
    Filed: November 25, 1998
    Date of Patent: September 28, 1999
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Hiroshi Kitamura, Makoto Tsuji, Noboru Fujiyoshi
  • Patent number: 5924470
    Abstract: Aluminum parts are cast in a plurality of permanent-type or semi-permanent-type molds, the molds being preheated to a predetermined temperature before starting the casting operation, and being provided with temperature sensors and a logic device which produces a blocking signal for the casting system when the temperature of the mold is below a predetermined casting temperature in order to minimize the number of scrap castings due to uneven or low mold temperature. Hot gases are created and flowed through the interior of the mold, by a burner and hood shaped to fit over at least some mold openings.
    Type: Grant
    Filed: October 28, 1996
    Date of Patent: July 20, 1999
    Assignee: Tendora Nemak, S.A. de C.V.
    Inventors: Onofre Costilla-Vela, Salvador Valtierra-Gallardo, Oscar Garza-Ondarza
  • Patent number: 5913358
    Abstract: The casting apparatus has a holding furnace for holding a reservoir of molten material, at least one smaller pumping furnace also for holding a reservoir of molten material and a casting cavity connected to the pumping furnace by one or more feed pipes. The pumping furnace is provided with a pressurizing assembly for applying a pressure to force the molten material from the pumping furnace into the casting cavity. The pumping furnace and holding furnace are contiguous and are connected by a non-return valve which prevents the flow of molten material from the pumping furnace to the holding furnace during pressurization but which allows the flow of molten material from the holding furnace to the pumping furnace after pressurization.
    Type: Grant
    Filed: June 7, 1996
    Date of Patent: June 22, 1999
    Assignee: Hi-Tec Metals Ltd.
    Inventor: Geoffrey Allan Chadwick
  • Patent number: 5887641
    Abstract: An injection device of a die casting machine including an injecting cylinder, in which a piston connecting to a piston rod is slidably thrust into a cylinder body and in which pressurized oil is fed to the side of the piston from a pressurized oil source and flows out from the side of the piston rod, and a servo valve controlling an injection speed of the injection cylinder device by controlling the amount of flow of pressurized oil that flows out from the injecting cylinder. The servo valve is directly attached to the cylinder body of the injecting cylinder and a flow channel connecting the injecting cylinder and servo valve is shortened.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: March 30, 1999
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Norihiro Iwamoto, Yukio Mizota, Masayuki Takamura
  • Patent number: 5875832
    Abstract: The apparatus includes a cylinder for holding molten material and a plurality of molds each having a plurality of cavities for receiving molten material. As the cylinder is rotated by a driving mechanism, the molten material is passed through a plurality of holes in a cylindrical wall which surrounds the holding area where the molten material is located, and into the cavities in the molds, which are transported in series beneath the cylinder as the cylinder rotates.
    Type: Grant
    Filed: February 21, 1996
    Date of Patent: March 2, 1999
    Assignee: Dale L. Haberny
    Inventors: Steven H. Senser, Dale L. Haberny
  • Patent number: 5855239
    Abstract: A method for controlling the injection of a die casting machine in which immediately after molten metal is injected into a cavity of metal molds at a high speed, the pressure oil in the chamber at the rod side of an injection cylinder is discharged into a tank side to commence the increase in pressure. A reference point for a switching-over position where a high speed charge is switched over to the increase in pressure is determined by computing a necessary length along the path for keeping the increased charging pressure on the basis of the supplied molten metal quantity during the previous injection process and subtracting the length from the length between the starting position and the position of limit of the forward movement at the previous injection process.
    Type: Grant
    Filed: December 9, 1996
    Date of Patent: January 5, 1999
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Norihiro Iwamoto, Hiroshi Yokoyama, Tai Matsuda
  • Patent number: 5792378
    Abstract: A method and apparatus for pouring molten metal in a crucible over a pouring lip of the crucible and into an opening in a mold is disclosed. The crucible and the mold are inside a chamber under vacuum, and the crucible is supported on a holder which is rotatable about first and second, spaced-apart, parallel, horizontal axes. The location of the first axis is selected so that over a limited arc the pouring lip moves primarily horizontally over a preselected distance such as 12-18 inches. The second axis is located so that tilting of the crucible about it causes the molten liquid to flow over the pouring lip. When the molten metal is to be poured, the manually or computer controlled actuators tilt the crucible about the first and second axes to position the lip so that the stream of metal flows into the mold opening at a predetermined rate.
    Type: Grant
    Filed: August 2, 1996
    Date of Patent: August 11, 1998
    Assignee: Lockheed Martin Advanced Environmental Systems, Inc.
    Inventors: Stanley E. Christensen, Richard E. Whitman
  • Patent number: 5769151
    Abstract: Methods for controlling the superheat of the stream of molten metal from an electroslag refining apparatus is taught. The methods include the introduction of unrefined metal into an electroslag refining process apparatus in which the unrefined metal is first melted at the upper surface of the refining slag. The molten metal is refined as it passes through the molten slag. The refined metal is collected in a cold hearth apparatus having a skull of refined metal formed on the surface of the cold hearth for protecting the cold hearth from the leaching action of the refined molten metal. A cold finger bottom pour spout or exit orifice is formed at the bottom of the cold hearth to permit dispensing of molten refined metal from the cold hearth.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: June 23, 1998
    Assignee: General Electric Company
    Inventors: William Thomas Carter, Jr., Mark Gilbert Benz, Robert John Zabala, Bruce Alan Knudsen, Paul Leonard Dupree
  • Patent number: 5758714
    Abstract: A ladle is rotationally tilted around its rotation shaft and the rotation center of the rotation shaft is moved along a locus deviating from the predetermined arc locus with its center at an imaginary initial pouring center which is set at or adjacent to a molten metal falling start point in the pouring spout of the ladle and, at the same time, the imaginary initial pouring center of the spout is moved while maintaining a fixed relationship with the rotation center of the rotation shaft, whereby the molten metal is poured to a fixed position in the pouring cup of the mold.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: June 2, 1998
    Inventors: Jiro Sato, Kenitsu Yoshida, Kouichi Banno
  • Patent number: 5697424
    Abstract: In an automatically operating molding and casting plant comprising a molding station (01) for producing molds (not shown) by compressing mold sand, a pouring station (05) and an extraction station (10), the main new feature is one or a number of video cameras (03, 09) depicting one or a number of process steps and/or the results of same, transmitting the corresponding image information to central control means (13, 14, 15), in which the image information is compared to "ideal" image information, e.g. image information previously read-in and based on a process step proceeding correctly, and which on the basis of the results of the comparison controls the affected stations in such a manner that undesired operational states or defective castings are avoided.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: December 16, 1997
    Assignee: Dansk Industri Syndikat A/S
    Inventors: Henrik Holm Ferdinandsen, Martin B.o slashed.jlund-Pedersen
  • Patent number: 5671797
    Abstract: A pressure casting method is disclosed, which permits sufficient pressurizing effect to be obtained for the entire molten metal by varying the speed of advancement of a pressurizing pin according to the state of solidification of the molten metal during pressurizing. In pressure casting using a pressure casting apparatus, while charged molten metal is solidified, it is pressurized by causing advancement of the pressurizing pin into a cavity of the die. During this time, the reaction force received by the pressurizing pin from the molten metal is measured by a pressure sensor, and the speed of advancement of the pressurizing pin is varied through control of the opening degree of a flow control valve according to the measured reaction force. While the reaction force during the progress of solidification of molten metal is high, the flow control valve is controlled to a high opening degree to provide for a high speed of advancement of the pressurizing pin so as to apply a high pressurizing force.
    Type: Grant
    Filed: August 17, 1995
    Date of Patent: September 30, 1997
    Assignees: Toyota Jidosha Kabushiki Kaisha, Gifu Seiki Kogyo Kabushiki Kaisha
    Inventors: Mikiya Nozaki, Mitsuhiro Karaki, Mitsuru Inui, Takehito Futamura, Akira Saitoh
  • Patent number: 5662159
    Abstract: A method and an apparatus of controlling the injection of a die casting machine can be used for any existing metal molds without requiring the use of a metal charge front sensor and shift the speed of advancement of the plunger rod to initiate a forced speed reduction of the plunger at a right timing regardless of variances in the charge of molten metal so that the machine may stably produce quality die cast products. Such a method of controlling the injection of a die casting machine for injecting molten metal fed to an injection sleeve into a metal mold by means of an injection plunger 100 to charge the metal mold with molten metal comprises the steps of detecting the pressure of the plunger rod charging the metal mold with molten metal; determining that the molten metal has arrived the gate section, or injection port, of the metal mold at a time when the detected pressure gets to a predetermined value; and controlling the injection speed on the basis of the time.
    Type: Grant
    Filed: March 26, 1996
    Date of Patent: September 2, 1997
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Norihiro Iwamoto, Masayuki Takamura
  • Patent number: 5630466
    Abstract: A blank is prepared of a thixotropic metal material and the blank is reheated to a semi-solid state to obtained a liquid fraction corresponding to a desired viscosity for shaping, while determining the power used in the reheating. The reheated blank is transferred to a forging press including a forging stamp or to a pressure die casting machine including an injection plunger. The resistance of the material to the forging stamp or the injection plunger is determined and defined as a set point value and the blank is shaped by the forging stamp or pressure die casting machine. A subsequent blank of the thixotropic metal material is shaped by the forging press or the pressure die casting machine, and the power used in reheating is regulated to maintain the resistance at the set point value.
    Type: Grant
    Filed: August 14, 1995
    Date of Patent: May 20, 1997
    Assignee: Aluminium Pechiney
    Inventors: Michel Garat, Willem Loue
  • Patent number: 5623984
    Abstract: The disclosed method of controlling a pressurizing pin, which serves to replenish for the necessary locality with molten metal during solidification of molten metal charged in the cavity, features that the operation of the molten metal replenishment by the pressurizing pin is caused when it is detected that the volume of non-solidified metal has become less than the volume effective for obtaining a molten metal replenishment effect. It is thus possible to obtain efficient replenishment for the necessary locality with molten metal by using a pressurizing pin which is limited in size and stroke.
    Type: Grant
    Filed: June 23, 1995
    Date of Patent: April 29, 1997
    Assignees: Toyota Jidosha Kabushiki Kaisha, Gifu Seiki Kogyo Kabushiki Kaisha
    Inventors: Mikiya Nozaki, Mitsuhiro Karaki, Mitsuru Inui, Takehito Futamura, Akira Saitoh
  • Patent number: 5622217
    Abstract: Operation can be switched from low- or high-speed injection process to intensified-pressure injection process by using only one accumulator, and an injection cylinder is composed of a single-acting cylinder, so that the space can be saved, and intensified-pressure surge can be reduced. A coaxial small-diameter portion is formed on the pressure surface side of a piston of the accumulator, a hydraulic oil discharge passage having an inside diameter corresponding to the outside diameter of the small-diameter portion is provided coaxial with the piston, and a passage is provided for guiding intensified-pressure oil in a cylinder chamber of the accumulator.
    Type: Grant
    Filed: September 14, 1995
    Date of Patent: April 22, 1997
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Norihiro Iwamoto, Yutaka Nakamura
  • Patent number: 5617911
    Abstract: A method and apparatus for the accurate formation of a three-dimensional article comprises providing a supply of substantially uniform size droplets of a desired material wherein each droplet has a positive or negative charge. The supply of droplets is focused or aligned into a narrow stream by passing the droplets through or adjacent an alignment means which repels each droplet toward an axis extending through the alignment means. The droplets are deposited in a predetermined pattern at a predetermined rate onto a target to form the three-dimensional article without a mold of the shape of the three-dimensional article. A supply of support material is provided in a predetermined pattern adjacent the deposited droplets. The support material receives a further supply of droplets which form a part of the three-dimensional article.
    Type: Grant
    Filed: September 8, 1995
    Date of Patent: April 8, 1997
    Assignee: Aeroquip Corporation
    Inventors: Robert A. Sterett, Atul M. Sudhalkar
  • Patent number: 5597032
    Abstract: A device for injection casting includes a furnace within which is position a crucible, a bell mounted atop a table into which a mold is positioned and a tube interconnecting the crucible and the mold. A device is provided to sense the level of metal within the crucible; piping is provided into the bell and the furnace for controlling the respective pressures therein and various sensors are provided in the bell, mold, tube and furnace which sense various pressures and temperatures experienced within the device during the casting operation. These sensors provide signals to a control apparatus which controls the pressure inside the furnace in order to fill the mold with metal inside the crucible and regulates the speed and pressure inside the mold. A method of operating the device is also provided.
    Type: Grant
    Filed: March 11, 1996
    Date of Patent: January 28, 1997
    Inventor: Pierre Merrien
  • Patent number: 5586435
    Abstract: A closed loop hydraulic system especially adapted as a shot control system for a die casting machine. The control system includes a voice coil driven pilot servo valve mounted to a high flow proportional valve. The control system provides a highly controllable restriction of the outflow of hydraulic fluid from a hydraulic shot cylinder which drives a shot plunger of a die casting machine. Position transducers are provided for the pilot servo valve, proportional spool valve, and shot cylinder and a control system monitors these inputs to provide closed loop control over the shot process. A hydraulic accumulator is located in each of the pressure source and return lines of the pilot servo valve and a hydraulic accumulator tank is mounted directly to the proportional valve.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: December 24, 1996
    Assignee: Servo Kinetics
    Inventor: George P. Kokalis
  • Patent number: 5566743
    Abstract: A method of injecting molten plastic or aluminum material into a cavity defined within a mold to form a desired part shape is provided. The method includes: (a) providing pressurized gas in the mold cavity prior to injection of molten material into the cavity; (b) generating a melt pressure sufficient to inject the molten material into the cavity; and (c) providing a closed loop controller to maintain a controllable difference between the melt pressure and the pressure of gas in the cavity throughout a substantial portion of a period of time during which molten material is being injected into the cavity, the difference being sufficient to inject molten material into the cavity in a manner to improve the conditions under which the material solidifies. By preloading the system with static pressure, conditions are created which allow generation, measurement and real time control of pressure difference profiles during transition of the melt throughout the injection cycle.
    Type: Grant
    Filed: January 10, 1995
    Date of Patent: October 22, 1996
    Inventor: Milko G. Guergov
  • Patent number: 5551502
    Abstract: In a low-pressure casting in which molten metal is introduced into a cavity of a casting mold under a pressure applied to the surface of the molten metal according to a preset reference pressurizing pattern, the reference pressurizing pattern is corrected when that the cavity has been filled with molten metal is detected and the pressure applied to the molten metal surface is controlled according to the reference pressurizing pattern after the correction. The pressure difference between a set pressure at a predetermined time in the reference pressurizing pattern after the correction and a set pressure at the corresponding time in the reference pressurizing pattern before the correction, is calculated and a set pressure for the period up to the time the cavity is filled with molten metal in the reference pressurizing pattern for the next casting cycle is corrected on the basis of the calculated pressure difference.
    Type: Grant
    Filed: May 12, 1995
    Date of Patent: September 3, 1996
    Assignee: Mazda Motor Corporation
    Inventors: Nobuyuki Matsubayashi, Toru Takeshita
  • Patent number: 5511605
    Abstract: A vacuum-controlling system for controlling the degree of vacuum in the vacuum system of a vacuum die-casting machine operates to: detect the degree of vacuum H at the instant of closure of the vacuum valve to the die mold cavity; compare the detected degree of vacuum H with a preset degree of vacuum Ho; correct a first position of the injection plunger for opening the vacuum valve by moving the first position in the advancing direction of the plunger by a specific distance in the case where H is higher than Ho; and correct the first position in the retracting direction of the plunger by a specific distance in the case where H is lower than Ho. By thus automatically correcting the position of the plunger for opening the vacuum valve to the optimum state, the formation of cavities or blowholes in the die-cast product is prevented, and at the same time, by maintaining the degree of vacuum in a specific state, the product quality is stabilized.
    Type: Grant
    Filed: July 7, 1994
    Date of Patent: April 30, 1996
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventor: Norihiro Iwamoto
  • Patent number: 5477907
    Abstract: An apparatus for delivering a metered shot of molten metal from a dispensing vessel through a shot tube comprises: a dispensing vessel for holding molten metal and having a shot tube for discharge of the molten metal, a reservoir of gas for pressurizing the dispensing vessel, a variable regulator for regulating the flow of gas. The regulator has a backload for varying the pressure at which the regulator regulates the flow of gas. An exhaust vent vents the dispensing vessel to the atmosphere. A supply valves opens and closes the delivery of gas to the holding vessel.
    Type: Grant
    Filed: December 10, 1993
    Date of Patent: December 26, 1995
    Assignee: Gasmac Inc.
    Inventors: Henry Meyer, Jason I. Aplin
  • Patent number: 5425411
    Abstract: A method for cooling a plunger tip of a die-casting machine for maintaining a proper clearance between a plunger tip and a shot sleeve. A proper hydraulic pressure in an injection cylinder is determined at which no galling occurs in the shot sleeve. Hydraulic pressure in the injection cylinder is measured several times in a state where no molten metal exists in the shot sleeve. For example, measured is the hydraulic pressure in the injection cylinder at the time of return stroke of the plunger tip immediately after injecting operation. Average hydraulic pressure is computed based on the plurality of measured hydraulic pressure. The average hydraulic pressure is compared with the proper hydraulic pressure. If the former is greater than the latter, clearance between the plunger tip and the shot sleeve is deemed to be too small. Thus, supply amount of cooling liquid to the plunger tip is increased to reduce a diameter of the plunger tip.
    Type: Grant
    Filed: December 28, 1993
    Date of Patent: June 20, 1995
    Assignee: Ryobi Ltd.
    Inventor: Shigetake Kami
  • Patent number: 5421397
    Abstract: An improved method of and system for die casting an engine block made of aluminum is provided. Included in the system is a calorific fluid for circulating through a bore pin assembly in a preselected temperature range which is continuously maintained by a heat transfer fluid controlling device.
    Type: Grant
    Filed: January 19, 1993
    Date of Patent: June 6, 1995
    Inventors: Robert K. Hembree, Mark L. Purtee
  • Patent number: 5407000
    Abstract: An automatic handling system is described for delivering a molten metal, such as magnesium or magnesium alloys, to a casting machine. The handling system comprises a programmable logic controller (PLC) for monitoring and controlling the sequential delivery of shots of a precise quantity of molten metal from a furnace or holding pot to a shot delivery apparatus of the casting machine. In the preferred system, the PLC also monitors and/or controls the temperatures of the molten metal in the holding pot and in a metal transfer system, the operation of a pump for pumping molten metal from the holding pot to the shot delivery apparatus, and the level of metal in the pot, and the operation of the the casting machine.
    Type: Grant
    Filed: February 13, 1992
    Date of Patent: April 18, 1995
    Assignee: The Dow Chemical Company
    Inventors: William E. Mercer, II, Harvey L. King, Carl F. Baker
  • Patent number: 5388633
    Abstract: An automatic ladling system is described for delivering a molten metal to the mold or die of a molding or casting machine. The ladling system comprises a programmable logic controller (PLC) for monitoring and controlling the sequential delivery of shots of a precise quantity of molten metal from a furnace or holding pot to a shot delivery apparatus of the casting machine. In the preferred system, the PLC also monitors and/or controls the temperature of the molten metal in the holding pot, the temperature of the molten metal in a metal transfer system, the operation of a pump for pumping molten metal from the holding pot to the shot delivery apparatus, the level of molten metal in the pot, and the operation of the casting machine.
    Type: Grant
    Filed: April 15, 1993
    Date of Patent: February 14, 1995
    Assignee: The Dow Chemical Company
    Inventors: William E. Mercer, II, Carl F. Baker, Harvey L. King
  • Patent number: 5385200
    Abstract: A casting method wherein casting cycles are continuously performed with respective molds and a common mass of molten metal accommodated in a container, such that in each casting cycle, the mold cavity is filled with the molten metal through a pouring tube connected at one end to a sprue hole of the mold and immersed at the other end in the molten metal mass, due to a difference between pressures to which the mold and the container are exposed, and wherein the molten metal temperature is estimated from the detected amount of consumption of the immersed tube, and the actual molten metal temperature is regulated, on the basis of a difference between a predetermined desired temperature of the molten metal, and the estimated temperature which changes with the actual temperature.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: January 31, 1995
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Isamu Yuki, Minoru Uozumi
  • Patent number: 5381855
    Abstract: The pouring ladle can not only be tilted by a tilting drive and a cable around a permanent tilting axis in order to pour the molten metal in a mould, respectively to interrupt the pouring process, but the tilting axis can be lifted and lowered by a determined value by a lifting drive. By lifting and lowering the tilting axis, the tilting motion of the pouring ladle takes place approximately in the center of gravity of the molten metal. This permits to avoid compensating streams and wave motions of the molten metal when the pouring ladle tilts forward and backward and more definite and reliable processes are achieved, capable to be controlled, at the start of pouring and at the time of terminating the pouring. The lifting drive and the tilting drive can be utilized for further lifting the pouring ladle in order to advance the pouring ladle further toward the center of the mould at the first pouring process under holding a determined distance of security from the mould.
    Type: Grant
    Filed: October 4, 1993
    Date of Patent: January 17, 1995
    Assignee: Maschinenfabrik & Eisengiesserei Ed. Mezger AG
    Inventor: Fritz Mezger
  • Patent number: 5375645
    Abstract: Shaped metal articles are produced on a continuous basis from semisolid metal preforms. The metal preforms are sequentially heated, then transferred, without substantial deformation or heat loss to a press where they are shaped in the semisolid state into shaped articles. While in the press, a ram is employed to drive the preform into a cavity of adjacent tooling to thereby shape the article. Prior to the forming operation, the ram is first advanced until it lightly engages the preform, then is withdrawn by a spaced distance to a first position defining the beginning of a stroke. Then, the ram is advanced, rapidly, from the first position against the preform to a second position contiguous with the tooling, thereby defining the end of the stroke. The spaced distance is chosen so as to preclude substantial heat drain from the preform and/or forced entry of air into the cavity and/or splashing of the semisolid metal outside of the cavity.
    Type: Grant
    Filed: January 19, 1993
    Date of Patent: December 27, 1994
    Assignee: Micromatic Operations, Inc.
    Inventors: Gordon W. Brueker, James L. Jalving
  • Patent number: 5375646
    Abstract: Casting parameters in at least one of a feeding and mold-filling and squeezing phase are controlled during a casting step in a cold-chamber die-casting machine. The casting parameters are controllable as a function of travel of a casting piston longitudinally displaceable in a shot sleeve. The quantity of molten metal filled in within the shot sleeve is determined by precise metering using a stationary optical measuring device. The metering is accomplished by beaming a measuring beam through a filling port of the shot sleeve and reflecting the measuring beam on a surface of the molten metal. The transit time of the measuring beam and the reflected beam are measured to determine a filling level and quantity of molten metal filled in. A control system is provided which controls a movement of the casting piston and a start of each phase as a function of the filling level and the associated quantity of molten metal filled in.
    Type: Grant
    Filed: September 15, 1993
    Date of Patent: December 27, 1994
    Assignee: Maschinenfabrik Mueller-Weingarten AG
    Inventors: Friedrich Stummer, Wolfgang Lutz
  • Patent number: 5372181
    Abstract: A counter pressure casting and a counter pressure casting device in which the pressures in a furnace side and a casting mold side are set to be lower than the maximum pressure of the process at a stage of the molten metal charging and increased to the maximum after the molten metal charging step. This technique provides a casting having less casting defects and improves the productivity.
    Type: Grant
    Filed: February 3, 1993
    Date of Patent: December 13, 1994
    Assignee: Hitachi Metals, Ltd.
    Inventors: Fukashi Watanabe, Shigeo Hama, Norio Minami
  • Patent number: 5365999
    Abstract: A method for the process control of a pressure diecasting machine, consisting of casting equipment (2) and a casting drive system (1), and an apparatus for carrying out the method are proposed. In order to regulate the movements both of the ram or drive plunger (8) in the pressing cylinder (7) and of the multiplier plunger (17) in the multiplier device (15) in each phase of the casting process, stepless devices (30, 31) measuring displacement and speed to determine the position or movements and also quick-adjustment servo-proportional valves (33 to 36) to regulate the movement both of the ram (8) and of the multiplier plunger (17) are provided.
    Type: Grant
    Filed: May 10, 1993
    Date of Patent: November 22, 1994
    Assignee: Maschinenfabrik Mueller-Weingarten AG
    Inventors: Friedrich Stummer, Rolf Frey, Albert Reinhardt, Wolfgang Lutz
  • Patent number: 5363899
    Abstract: A method of discriminating the quality of die-cast articles when casting an article by pressurizing and filling a molten metal into a die through an injecting sleeve using an injecting plunger. The method has the steps of measuring at least one of the operational parameters of a die temperature, a gas pressure in a die cavity, a molten metal pressure in a die cavity, an injecting sleeve temperature, an injecting plunger travel speed, and an injection plunger displacement; and discriminating the quality of a die-cast article by comparing the measured parameter value with a reference value determined on the basis of a predetermined interrelationship between the operational parameter and an allowance limit of the amount of a casting defect.
    Type: Grant
    Filed: April 23, 1993
    Date of Patent: November 15, 1994
    Assignee: Nippondenso Co., Ltd.
    Inventors: Hiromi Takagi, Fumitaka Takehisa, Mitsuyoshi Yokoi
  • Patent number: 5361826
    Abstract: A laminar flow injection molding apparatus and a laminar flow injection molding method capable of directly judging flow mode of molten metal flowing into a metal mold, either laminar flow mode or turbulent flow mode. An injection molding apparatus includes metal molds in which a runner portion, a cavity, and a gas vent passage are formed in communication with a casting sleeve. Molten metal detection members are provided in confrontation with at least one of the runner portion, the cavity and the gas vent passage. In a single injecting operation, molten metal detection signal is generated each time the molten metal is brought into contact with the detection member. The molten metal detection member is connected to a counter circuit where numbers of the detection signals are stored as a count value. A judgment circuit to which a preset value is inputted is electrically connected to the counter circuit so as to compare the count value with the preset value.
    Type: Grant
    Filed: March 4, 1993
    Date of Patent: November 8, 1994
    Assignee: Ryobi Ltd.
    Inventors: Noriyoshi Yamauchi, Hitoshi Ishida, Hirotake Usui, Yoshiaki Egoshi
  • Patent number: 5348073
    Abstract: The apparatus for producing a cast steel article has a permeable mold having a cavity, a sprue and at least one rise/run-off portion, and a vacuum apparatus, the permeable mold being provided with a hole having an opening on a mold surface near the rise/run-off portion, the vacuum apparatus being provided with a suction pipe having an opening which is brought into contact with the hole of the permeable mold, wherein the air is sucked from the hole by the vacuum apparatus, in order to conduct the casting of the article at reduced pressure.
    Type: Grant
    Filed: April 1, 1993
    Date of Patent: September 20, 1994
    Assignee: Hitachi Metals, Ltd.
    Inventors: Kimio Kubo, Naotaka Deki
  • Patent number: 5309976
    Abstract: A method of making a casting wherein a molten alloy is introduced into a mold cavity at an initial mold fill rate to partially fill the mold cavity while the mold cavity resides in a casting chamber. A solidification front is propagated through the molten alloy to provide a solidification rate. The remaining molten alloy is introduced into the mold at a second mold fill rate less than the first mold fill rate as the front propagates through the molten alloy. The second fill rate is controlled to correspond or be matched generally to the solidification rate of the molten alloy in the mold cavity.
    Type: Grant
    Filed: March 16, 1993
    Date of Patent: May 10, 1994
    Assignee: Howmet Corporation
    Inventors: Paul D. Prichard, Paul R. Aimone
  • Patent number: 5299626
    Abstract: An injection speed control valve for controlling the speed of flow of operating fluid from an operating fluid source of the die-casting machine to an injection cylinder, a pressure compensation valve for controlling the pressure of the operating fluid to a predetermined differential valve pressure to be coupled to the injection speed control valve, a bypass duct communicating the operating fluid source and the injection speed control valve, a logic valve for on-off controlling the flow of the operating fluid through the bypass duct, and a solenoid valve for on-off operating the logic valve, are provided. The speed of injection by the injection cylinder is controlled by switching the logic valve with the solenoid valve while maintaining a predetermined opening degree of the injection speed control valve.
    Type: Grant
    Filed: March 9, 1993
    Date of Patent: April 5, 1994
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventor: Norihiro Iwamoto
  • Patent number: 5297613
    Abstract: A method for producing a rotationally symmetrical body from a molding material, such as a molten metal, which comprises atomizing the molding material in liquid form through a spraying nozzle that is disposed relative to a spray receiving the sprayed molding material on an initial position of said surface, forming a level of liquid molding material on said spray receiving surface and molding material, forming a controllably rotating body of said liquid molding material while it is solidifying, said solidifying rotating body having a diameter, drawing the so-formed body downwardly from said initial position while continuing its rotation, continuously forming said body at said initial position, monitoring the diameter values of the rotating body at a plane adjacent to said initial position, and controlling said rotation by said diameter values.
    Type: Grant
    Filed: October 21, 1992
    Date of Patent: March 29, 1994
    Assignee: Mannesmann Aktiengesellschaft
    Inventors: Norbert Uebber, Hans-Joachim Kreymann
  • Patent number: 5269362
    Abstract: Herein disclosed is an automatic molten metal distribution system having a function to automatically decide what one of the reserving furnaces 31 of a plurality of casting machines 30 the molten metal 36 is to be distributed. The automatic molten metal distribution system comprises: a molten metal distributor 20 for distributing the molten metal 36 to the individual reserving furnaces 31 of the plurality of casting machines 30; cast amount metering apparatus 39 for metering the individual cast amounts cast by the casting machines 30; and distributor control apparatus 22 for controlling the distributor 20 so as to distribute the molten metal 36, when the cast amount cast by any casting machine metered by the cast amount metering apparatus 39 reaches a preset cast amount set for each of the casting machines 30, to the reserving furnace 31 of said any casting machine 30.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: December 14, 1993
    Assignee: Hitachi Metals Ltd.
    Inventor: Satoshi Yamashita
  • Patent number: 5240064
    Abstract: A method for molding a fusible core from a molten metal, including filling a mold by forcing back molten metal under pressure into the mold by means of a positive displacement pump equipped with a pressure regulator and having an output rate, total filling of the mold corresponding to a manometric height; measuring the pressure of the forced-back metal; adapting the output rate of the positive displacement pump so that the growing pressure imposed on the forced-back molten metal does not undergo any sudden variation during filling of the mold; and limiting the pressure exerted on the molten metal to a maximum pressure value which is slightly higher than the manometric height.
    Type: Grant
    Filed: May 11, 1992
    Date of Patent: August 31, 1993
    Assignee: Solvay (Societe Anonyme)
    Inventors: Michel Vansnick, Luc De Keyzer
  • Patent number: 5219409
    Abstract: The process calls for testing and monitoring the pressure levels in different parts of the die casting apparatus during a casting operation, including the die cavity itself and in positive and vacuum pressure lines. The process also includes process steps which cools a vacuum valve adjacent the die cavity and cleans the valve and lines during a casting operation. The process calls for aborting a casting operation at various time during the operation if certain measured parameters are not acceptable.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: June 15, 1993
    Assignee: Outboard Marine Corporation
    Inventors: Dave L. Campbell, George R. Clark, Frank W. Kenik, Russell J. VanRens