VERTICAL DIE CASTING METHOD AND APPARATUS

Abstract: A vertical die casting apparatus comprises a mold clamping unit having a mold axis and a tilting injection unit (60). The mold clamping unit in corporation with a machine base (100) is made to swing about a rotation axis from a normal horizontal axis position at which the mold axis extends horizontally and the injection unit is actuated for a vertical injection, to a vertical axis position at which the mold axis extends vertically, and a dis­ integratable core (10) incorporated in the mold to define a mold cavity.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved injection molding method according to claim 1 and apparatus according to claim 4 for producing a cast product of aluminum or the like, particularly preferable when a disintegratable core or a sand core is set to a mold at every casting shot. 2. Description of the Related Art A cast product having an undercut portion or a cavity is generally prepared by a gravity casting machine, which is a casting machine having a relatively low pressure, or a low-pressure molding machine, while utilizing a sand core formed by solidifying a casting sand by a phenolic resin or the like. The low-pressure casting machine, however, is defective in that the casting cycle is long, the thickness of a cast product cannot be reduced, and it is difficult to stabilize the quality of the cast product. Recently, however, it has become possible to perform the molding operation by a high-pressure casting machine by utilizing a disintegratable core such as a sand core, by which the melt is prevented from intruding into the core and the injection molding method is improved. The high-pressure casting machine is classified as a lateral casting system or a vertical casting system, according to the casting direction. The lateral casting system was a lateral die casting machine, and the casting machine used by the vertical casting system is classified as a vertical clamping type on a lateral clamping type. The high-pressure casting machine of the vertical casting system, for example that described in German Patent No. DE-B-2705607, upon which the preambles of claims 1 and 4 are based, gives especially excellent results in that, since the contact area between the metal and the melt cast in a casting sleeve is small, there is little reduction of the temperature of the melt and the intrusion of a gas into the casting sleeve is inhibited. In the molding method and casting machine using a disintegratable core, the disintegratable core must be easily attached to the molds, the melt must run correctly during the casting operation, and defects such as blow holes formed by an intrusion of gas into a molded product and cavities such as ingot pipings caused by solidification and contraction, must not be formed. The disintegratable core must not be broken during the casting operation, there must be no intrusion of the molten metal into the sand core, i.e., melt intrusion, the core must be easily removed after the casting operation, and no sand must remain on the cast product. As pointed out hereinbefore, the high-pressure casting machine is classified as the lateral clamping type or the vertical clamping type, according to the clamping direction, and as the lateral casting system or the vertical casting system according to the casting direction. In the lateral clamping type, since the melt is filled in the rising state in the cavity, there is less intrusion of gas than in the vertical clamping type during the casting operation, and since a gas vent formed on the parting face of the mold is not clogged before completion of the filling operation, casting defects such as blow holes do not occur. In the vertical casting system, since the contact area between the metal and the melt cast in the casting sleeve is smaller than in the lateral casting system, there is less reduction of the temperature of the melt, and since the intrusion of gas does not occur in the injection sleeve during the casting operation, casting defects such as blow holes do not occur. Accordingly, for the above-mentioned reasons, a high-pressure casting machine of the vertical casting system and lateral clamping type is most widely used as the high-pressure casting machine using a disintegratable core. Although a product having a high casting quality can be produced by this casting machine, the attachment of the disintegratable core to the molds is cumbersome, and particularly when the disintegratable core is supported by a movable core, since the disintegratable core must be suspended in the air, and thus is not precisely positioned, the disintegratable core can be easily broken by collision with the mold. Furthermore, when the skirt portion of the disintegratable core is inserted into the supporting portion of the mold, the sand constituting the skirt portion is eroded by rubbing on the mold and intrudes into the melt during the casting operation to form defects, and thus it is difficult to easily obtain a good product. Moreover, in principle, automation of the attachment of the disintegratable core is impossible. SUMMARY OF THE INVENTION A primary objet of the present invention is to overcome the above-mentioned disadvantages and greatly improve the quality of a molded product prepared by using a disintegratable core and to provide a casting machine in which automatic attachment of the disintegratable core is possible. According to a first aspect of the present invention, there is provided a die casting machine comprising a mold clamping unit defining a mold axis, the mold clamping unit incorporating a platen and a mold half detachably mounted thereon, the platen and mold half being stationary relative to the said mold axis, and a counter part platen and a second mold half detachably mounted thereon, the counter part platen and second mold half being movable along the mold axis before combining both said mold halves at parting faces thereof to form a mold defining a mold cavity to be filled with a melt, an injection unit for injecting the melt into the said mold cavity, said injection unit having a casting sleeve through which the melt is injected and being swingably mounted on a machine base, and a tilting means connected rotatably to both said injection unit and machine base for tilting said injection unit from a vertical position in which the melt is to be injected upwardly to a tilted position in which a fresh melt is supplied to said casting sleeve, characterised in that the said mold forms a mold gate at the parting faces extending perpendicularly to said mold axis, through which gate the melt may enter the cavity, said mold clamping unit is swingably mounted on the said machine base for rotation about a rotation axis provided at the stationary platen and extending perpendicular to said mold axis on a horizontal plane, the mold clamping unit being swingable from a horizontal axis position in which said mold axis extends horizontally and said mold stationary and movable platens of said clamping unit lie on said machine base to receive aninjection of the melt into said cavity through said mold gate, to a vertical axis position where said mold axis extends vertically and said stationary platen of said mold clamping unit stands on said machine base, and a means connected rotatably to both said machine base and the stationary platen is provided for driving said mold clamping unit for rotation about said rotation axis. Preferably the die casting machine is provided with a stopper means at said movable platen for holding said mold clamping unit at said horizontal axis position, so that said tilting injection unit when standing vertically on said machine base is located between said stopper means and said rotation axis. Preferably the driving means comprises a piston-cylinder unit rotatably mounted on said machine base for actuating a piston rotatably connected to said stationary platen. Preferably means are provided for positioning at least one mold core relative to said mold when said mold is provided with said core therein at said vertical axis position. Preferably the core positioning means comprises a product separating means mounted to said stationary platen or said stationary mold half for driving axial pins through pin holes formed in said stationary mold half to push a cast or molded product after said movable mold half is separated from said stationary mold half and a means for actuating said product separating means so that axial projections of said push pins from said stationary mold are maintained to thereby support said core from below when provided in said mold at said vertical axis position. Preferably the die casting machine further comprises a mold core unit outside said mold opposite to the side of said mold gate for providing a second mold core in said mold, which second core is movable into said mold along a line perpendicular to said mold axis through a hole formed by the parting faces, said stationary mold having a recess formed in the inner surface at the mold gate side for receiving one end of said first mentioned core while temporarily supported by said push pins, and said second core has a groove formed to face the parting face of said movable mold for receiving the opposite end of said first core supported by said push pins in cooporation with said recess when said second core is moved from an outer position to an inner one, said first core being clamped at said opposite end for completion of the provision of said first core in said mold, after said projected pins are withdrawn from an inner position to an outer one, by both said second core and movable mold half therebetween when said mold halves are joined, at said vertical axis position. Preferably the first core is disintegratable, for instance it may be made of sand with a resin cover. Preferably the tilting injection unit comprises a first piston-cylinder unit for injecting the melt, a plunger rod connected to said piston, a sleeve frame connected to said casting sleeve, and a second piston-cylinder unit where said sleeve frame forms a movable cylinder and said cylinder of said first piston-cylinder unit forms a stationary piston, for activating said sleeve frame with said casting sleeve to move upward relative to said first piston-cylinder unit at said horizontal axis position so that said casting sleeve communicates with said mold gate for the upward injection. According to a second aspect of the present invention, there is provided a vertical die casting method using an apparatus comprising a machine base, a mold clamping unit having a mold axis, a mold half movable along the mold axis, another mold half stationary relative to the mold axis so that both mold halves may be joined at parting faces thereof to form a mold defining a mold cavity to be filled with a melt, and an injection unit for injecting the melt upwardly into the mold cavity, the injection unit being movable between a melt receiving position and a melt injection position, characterised in that at every casting shot, the mold clamping unit is swung about a horizontal rotation axis perpendicular to the mold axis from a horizontal mold axis position to a vertical mold axis position, at least one mold core is inserted into the mold cavity when the mold clamping unit is at said vertical mold axis position, the mold clamping unit is returned to said horizontal mold axis position, and the melt is injected upwardly from said injection unit into the mold cavity through a mold gate formed at the parting faces with the mold clamping unit in said horizontal mold axis position. Preferably the mold clamping unit is provided with a product separating means for driving axial pins through pin holes formed in the stationary mold half to push out a cast or molded product after the movable mold half is separated from the stationary mold half, further comprising a step of activating the product separating means at said vertical mold axis position so that axial projections of the push pins from the stationary mold half are maintained for the subsequent step of inserting the core into the mold cavity, such that the core is supported from below by the projecting push pins facilitating positioning of the core relative to the mold. Preferably, the core is disintergratable, for instance it may be made of sand with a resin cover. Since the casting device or appartus of the present invention is the vertical type, gas does not intrude when the melt rises within the casting sleeve. Furthermore, when the melt is cast in the cavity, the melt is filled in the cavity while rising from the lower portion of he cavity, thus expelling any gas. The air vent formed on the parting faces of the mold halves is not clogged before completion of the filling, and accordingly, the gas is effectively discharged to the outside of the mold throughout the filling operation. If the casting operation is carried out by using the disintegratable core in the above-mentioned manner, a good molded product in which a formation of low holes or ingot pipings is substantially eliminated can be obtained without breaking the disintegratable core. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows two partially sectional longitudinal views of a vertically die casting apparatus according to the present invention, at a horizontal axis position (H) illustrated by solid lines and at a vertical axis position (V) illustrated by dotted lines, respectively; Fig. 2 is a cross sectional view of the apparatus at the horizontal axis position (H), taken along the line II-II of Fig. 1; Fig. 3 is a side view showing the apparatus at the horizontal axis position (H), viewed in a direction of the arrow III of Fig. 1; Fig. 4 is a partially sectional view of the apparatus at the vertical axis position (V), illustrated by solid lines; and Figs. 5A, 5B, 5C, 5D, 5E and 5F are sectional view diagrams showing, in this order, steps for forming a process of providing a mold comprised of stationary and movable core at the vertical axis position (V) of the casting apparatus according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 shows the longitudinal section of a die casting machine, and illustrates the pressure casting method using a disintegratable core 10 according to the present invention. The structure of the die casting machine is first described with reference to Fig. 1, Fig. 2, Fig. 3, and Fig. 4. The die casting machine comprises a mold clamping device 20, an injection device or unit 60, and a machine base 100 on which the respective devices are arranged and which is secured to a floor surface 130. The mold clamping device or unit 20 is provided with a stationary platen 21 on one end and a mold clamping cylinder platen 23 on the other end. The four corners of each of the stationary platen 21 and mold clamping cylinder platen 23 are clamped by nuts 24 to form a column 25. A movable platen 22 is supported on the column 25 in such a manner that the movable platen 22 can be advanced and retracted relative to the stationary platen 21 by a mold clamping cylinder 26 attached to the mold clamping cylinder platen 23. A stationary mold half 27 and a movable mold half 28 are attached to the stationary platen 21 and the movable platen 22, respectively, so that the molds are openably and closably combined, with split parting faces 29 as the boundary thereof. Both mold halves 27 and 28 define a cavity 30 having the same shape as that of a cast product, a constricted portion or mold gate 31 subsequent to the cavity 30, a large-diameter hole portion-32 opened downward below the constricted portion 31 subsequent thereto, and a casting sleeve-fitting hole 33, which are divided by the parting face 29. An air vent 34, which is a shallow groove for discharging the gas in the cavity 30 to the outside of the mold at the casting operation, is formed on the parting face 29. The stationary mold half 27 is provided with a push device 35 comprising a push pin 36 for pushing out a product from the mold, a push pin cylinder 40 secured to the stationary platen 21 to actuate the push pin 36, a push connecting rod 38 for connecting the push pin cylinder 40 to the push pin 36, a push connecting plate 37 for connecting the push pin 36 to the push connecting rod 38, and a push plate 39 for connecting the push pin cylinder 40 to the push connecting rod 38. Moreover, the stationary mold half 27 is further provided with a slidable movable core 41 forming a part of the stationary mold half 27 and defining a part of the cavity 30, a core cylinder 42 in which the movable core 41 is allowed to slide, and a core cylinder attachment bracket 43 for attaching the core cylinder 42 integrally to the stationary mold half 27. A stationary core 45 having a supporting groove 44 defining the cavity 30 and supporting the disintegratable core 10 is built in the stationary mold half 27 on the side of the face of the cavity 30. The supporting groove 44 is also formed on the movable core 41, and thus a disintegratable core 10 can be supported in the space of the cavity 30 by the supporting grooves 44 of the movable core 41 and a stationary core 45 forming a part of the stationary mold half. On the side opposite to the stationary mold-attaching face 46 of the stationary platen 21 are disposed a pair of rotation cylinders 102 for rotating and driving the entire mold clamping device 20 around a rotation shaft pin 102, and a pair of bearing portions 49 attached rotatably through a pin 48, integral with the stationary platen 21. A bearing portion 103 projected integrally from the machine base 100 for rotating the entire clamping device 20 by the operation of the rotation cylinders 101 and a pair of projected bearing portions 47 integrally forming the center of rotation through a pin 102, are arranged in the lower portion of the stationary platen 21. The structure of the injection device or unit 60 will now be described. The injection device 60 is connected through a rotation shaft 105 to a pair of injection device-supporting plates 104 arranged below the machine base 100 and integral therewith. The injection device 60 can swing in the longitudinal direction of the mold clamping device 20 with the rotation shaft 105 as the center. The swinging or tilting movement of the injection device 20 is accomplished by a tilting cylinder 63 having one end connected to a bracket 106 attached integrally to the machine base 106, and the other end connected to an injection cylinder 61 through a clevis 62. A piston 64 is arranged within the injecting cylinder 61, and a plunger rod 66 and a plunger tip 67 are connected to the top end of the piston 64 through a plunger coupling 65. A docking ram 68 having a shape resembling a pair of round rods and having an oil pipe path 69 piercing through the interior thereof is arranged on the injection cylinder 61 in such a manner that one end is secured to the injection cylinder 61 and the other end is fitted to an oil-introducing chamber 71 of a sleeve frame 70. A casting sleeve 73 is fixed to the upper end of the sleeve frame 70 through a sleeve coupling 72. The plunger tip 67 is slidably engaged with the interior of the casting sleeve 73. A melt 74 is poured into the casting sleeve 73 by a melt supply device, not shown in the drawings. The structure of the machine base 100 will now be described. A stopper 107 for setting the position of the erect posture of the mold clamping device 20, which rotates around the rotation shaft 102 when the disintegratable core 10 is attached to the molds or a product is withdrawn from the molds, is arranged integrally with the machine base 100 in the end portion of the machine base 100 on the side of the stationary platen 21. In the vicinity of the lower part of the stationary platen 21, a cylinder bearing 108 having the above-mentioned rotation cylinders 101 rotatably attached thereto is arranged integrally with the machine base 100. A pair of stoppers 109 for setting the position of the molding clamping device 20 when rotated to a horizontal posture or a horizontal axis position (H) are arranged on the upper face of the machine base 100 integrally therewith in the vicinity of the movable platen 22. The device 110 for preventing a rising of the mold clamping device 20 during the casting operation will now be described. A pair of setting plates 111 projected from the machine base 100 and integral therewith are arranged on the upper surface of the machine base 100 in the vicinity of the mold clamping cylinder plate 23, a cylinder 112 for preventing a rising of the mold clamping device 20 is arranged on each of the setting plates 111, and a rising-preventing pin 113 is attached to the top end of the rod of the rising-preventing cylinder 112. This pin 113 is engaged with a hole 150 projected below the mold clamping plate 23 and integral therewith at the time of injection, to prevent a rising of the mold clamping device 20. The disintegratable core 10 defining an undercut portion or cavity portion of a cast product will now be described. A sand core is molded from a sand for a shell mold, which comprises 100 parts of siliceous sand JIS No. 7 as the aggregate, 2.0 parts of a thermosetting phenolic resin as the organic binder, and 0.1 part of calcium stearate as the lubricant. The molding conditions are; a mold temperature of 270° and a calcination time of 20 seconds. Then, 1 ℓ of water is thoroughly mixed and stirred with 300 cc of colloidal silica (SiO₂ = 30%) as the binder, 10 g of sodium dodecylbenzene-sulfonate as the lubricant, and 1 g of octyl alcohol as the defoaming agent, 300 g of zircon flower pulverized to a size smaller than 300 mesh is added to the solution, and the mixture is thoroughly stirred to form a slurry solution. The above-mentioned shell core is immersed in the slurry solution for 1 minute to fill surface voids of the sand core and, immediately, the sand core is dried for 30 minutes by a hot air drier at 120°C to harden the surface of the core. A slurry solution formed by thoroughly mixing and stirring 1 ℓ of a 3% aqueous solution of a water-soluble phenolic resin with 500 g of mica pulverized to a size smaller than 300 mesh, 10 g of sodium dodecylbenzene-sulfonate as the lubricant, and 1 g of octyl alcohol as the defoaming agent is brush-coated on the surface of the sand core and the sand core is dried for 1 hour by a drier at 120°C. The operation of the die casting apparatus having the above-mentioned structure will now be described, with reference to Fig. 1 and Figs. 5A to 5P. When the disintegratable core 10 is attached to the mold, in the state wherein the rotation cylinder 101 is withdrawn, the entire mold clamping device 20 takes an erect posture, i.e., the vertical axis position (V), in which the parting face 29 lies is in the horizontal direction, as indicated by two-dot chain lines in Fig. 1 and by solid lines in Fig. 4. The movable mold half 28 defining the cavity 30 is opened by retraction of the mold clamping cylinder 26 (Fig. 5A), and the movable core 41 is opened by retraction of the core cylinder 4 (Fig. 5A). In this state, oil is fed to the rod end side of the push pin cylinder 40 and the push pin 36 is projected into the cavity 30 to form a temporary supporting stand for holding the disintegratable core 10 in the cavity 30 (Fig. 5B) at a recess (27a) of the stationary mold half (27). By a device for automatically setting the disintegratable core (not shown), the disintegratable core 10 is delivered to the upper portion of the stationary mold half 27 and is arranged on the push pin 38 in a state wherein one skirt portion 51 is engaged with the supporting groove 44 of the stationary core 45 (Fig. 5C). Then, the oil is guided to the head end side of the core cylinder 42 and the movable core 41 is advanced, and thus the supporting groove 44 of the movable core 41 is engaged with the skirt portion 51 on one end of the disintegratable core 10 (Fig. 5D). The push pin 38 is then retracted and the attachment of the disintegratable core 10 to the cavity 30 is completed (Fig. 5E). Oil is then fed to the head end side of the mold clamping cylinder 26 to advance the mold clamping cylinder 26, and the clamping of the molds is completed (Fig. 5F). When the molds are clamped, the oil is fed to the head end side of the rotation cylinder 101 to rotate the entire mold clamping device 20 around the rotation shaft 102, and the mold clamping device 20 takes the horizontal posture or the horizontal axis position (H) and stops when the movable platen 22 impinges against the stopper 109. When the rotation is completely stopped, the oil is fed to the head end side of the rising-preventing cylinder 112 arranged on the machine base 100 to insert the rising-preventing pin 113 into the hole 150 of the mold clamping cylinder plate 23. In connection with the operation of the injection device 60, when the tilting device 63 pushes, i.e., when the injection cylinder 61 is tilted, the melt 74 is poured into the casting sleeve 73 by an automatic melt supply device, not shown in the drawings. On completion of the pouring of the melt 74, the oil is fed to the rod end side of the tilting cylinder 63 and the injection device 60 is rotated to an erect posture or a vertical axis position. On completion of the rotation, the oil is fed into the oil introduction chamber 71 of the sleeve frame 70 through the oil pipe path 69 of the docking ram 68, and the melt 74 in the casting sleeve 73, the casting sleeve 73, the sleeve frame 70, the plunger chip 67, the plunger rod 66, and the piston of the injection cylinder 61 are integrally elevated, and the upper face of the casting sleeve 73 is impinged against the upper face of the casting sleeve-fitting hole 32 formed by the stationary mold half 27 and movable mold half 28 and stopped. On completion of the elevation of the casting sleeve 73, the oil is fed to the head end side of the injection cylinder 61 to elevate the piston 64, and thus the melt 74 is made to rise in the casting sleeve 63 without an intrusion of gas. The piston 64 is further elevated and the melt 74 is cast in the cavity 30 vertically, but since the melt 74 is filled in the cavity in the rising state, gas does not intrude into the cavity 30. The gas in the cavity 30 is expelled by the melt 74 and is discharged to the outside of the mold through the gas-discharge vent 34 formed on the parting faces 29. When the cavity is completely filled with the melt 74, the force at the injection cylinder 61 tries to raise the entire mold clamping device 20, but any rising or rotation of the mold clamping device 20 is prevented by the rising-preventing pin 113. When solidification and cooling of the melt are completed after a predetermined time, the oil is fed to the rod end side of the injection cylinder 61 and the piston 64 is withdrawn. Midway in this withdrawal movement, the plunger coupling 65 impinges against the sleeve frame 70. At this point, the pressure in the oil introduction chamber 71 of the sleeve frame 70 of the docking ram 68 is released, and the casting sleeve 73 and sleeve frame 70 are pressed down and are withdrawn simultaneously with the withdrawal of the piston 64. On completion of this withdrawal movement, the oil is fed to the head end side of the tilting cylinder 63 to tilt the injection device 60, and the injection device 60 is returned to the vertical axis position (H) indicated by the two-dot chain lines in Fig. 1 and solid lines in Fig. 4. The oil is then fed to the rod end side of the rotation cylinder 101 to rotate the mold clamping device 20, and the mold clamping device 20 impinges against the stopper 107 of the machine base 100 and stops in the erect state indicated by the two-dot chain lines in Fig. 1. On completion of the rotation, the oil is fed to the rod end side of the mold clamping cylinder 26 to open the mold. Furthermore, the oil is fed to the rod end side of the core cylinder 42 to retract the movable core 41, and then the oil is fed to the rod end side of the push pin cylinder 40 to push out a product left in the mold halves to outside of the mold. On completion of this push, the oil is fed to the head end side of the push pin cylinder 40 to return the push pins 36. Thus, one cycle of the molding operation is completed. As an experiment, an aluminum alloy ADC12 was cast under conditions of a melt temperature of 680°C, a metal pressure of 400 kg/cm², and a plunger speed of 50 mm/sec. The sand was removed from the molded product discharged from the mold, and it was found that no intrusion of the sand into the surface of the disintegratable sand core 10 had occurred and a high-quality molded product free of blow holes and cavities, such as ingot pipings in the interior, was obtained. As apparent from the foregoing description, if the disintegratable core is disposed in the mold halves in the state wherein the mold clamping device takes an erect posture or the vertical axis position (V) and the parting faces of the mold lie in the horizontal direction, the position of the disintegratable core in the mold cavity is precisely set, and breaking of the disintegratable core by contact with the movable core or movable mold half at the time of closing of the mold balves, or degradation of the quality of the molded product due to eroded sand, does not occur. Moreover, if the casting operation is carried out by the vertical casting apparatus at the horizontal axis position (H) with the injection device kept vertical, gas does not intrude into the melt and a molded product having a high quality can be obtained.

Claims: A vertical die casting method using an apparatus comprising a machine base (100), a mold clamping unit (20) having a mold axis, a mold half (28) movable along the mold axis, another mold half (27) stationary relative to the mold axis so that both mold halves (27, 28) may be joined at parting faces (29) thereof to form a mold defining a mold cavity (30) to be filled with a melt (74), and an injection unit (60) for injecting the melt (74) upwardly into the mold cavity (30), the injection unit (60) being movable between a melt receiving position and a melt injection position, characterised in that at every casting shot, the mold clamping unit (20) is swung about a horizontal rotation axis perpendicular to the mold axis from a horizontal mold axis position to a vertical mold axis position, at least one mold core (10) is inserted into the mold cavity (30) when the mold clamping unit (20) is at said vertical mold axis position, the mold clamping unit (20) is returned to said horizontal mold axis position, and the melt (74) is injected upwardly from said injection unit (60) into the mold cavity (30) through a mold gate (31) formed at the parting faces (29) with the mold clamping unit (20) in said horizontal mold axis position. A die casting method according to claim 1, wherein the mold clamping unit (20) is provided with a product separating means (40) for driving axial pins (36) through pin holes formed in the stationary mold half (27) to push out a cast or molded product after the movable mold half (28) is separated from the stationary mold half (27), further comprising a step of activating the product separating means (40) at said vertical mold axis position so that axial projections of the push pins (36) from the stationary mold half (27) are maintained for the subsequent step of inserting the core (10) into the mold cavity (30), such that the core (10) is supported from below by the projecting push pins (36) facilitating positioning of the core (10) relative to the mold. A vertically die casting method according to claim 1 or 2, wherein said core (10) is disintegratable and made of sand with a resin cover. A die casting machine comprising a mold clamping unit (20) defining a mold axis, the mold clamping unit (20) incorporating a platen (21) and a mold half (27) detachably mounted thereon, the platen (21) and mold half (27) being stationary relative to the said mold axis, and a counter part platen (22) and a second mold half (28) detachably mounted thereon, the counter part platen (22) and second mold half (28) being movable along the mold axis before combining both said mold halves (27, 28) at parting faces (29) thereof to form a mold defining a mold cavity (30) to be filled with a melt (74), an injection unit (60) for injecting the melt (74) into the said mold cavity (30), said injection unit (60) having a casting sleeve (73) through which the melt (74) is injected and being swingably mounted on a machine base (100), and a tilting means (63) connected rotatably to both said injection unit (60) and machine base (100) for tilting said injection unit (60) from a vertical position in which the melt (74) is to be injected upwardly to a tilted position in which a fresh melt is supplied to said casting sleeve (73), characterised in that the said mold (27, 28) forms a mold gate (31) at the parting faces (29) extending perpendicularly to said mold axis, through which gate (33) the melt (74) may enter the cavity (30), said mold clamping unit (20) is swingably mounted on the said machine base (100) for rotation about a rotation axis provided at the stationary platen (21) and extending perpendicular to said mold axis on a horizontal plane, the mold clamping (20) unit being swingable from a horizontal axis position in which said mold axis extends horizontally and said mold stationary and movable platens (21, 22) of said clamping unit (20) lie on said machine base (100) to receive an injection of the melt (74) into said cavity (30) through said mold gate (31), to a vertical axis position where said mold axis extends vertically and said stationary platen (21) of said mold clamping unit (20) stands on said machine base (100), and a means (48, 49, 101, 108) connected rotatably to both said machine base (100) and the stationary platen (21) is provided for driving said mold clamping unit (20) for rotation about said rotation axis. A die casting machine according to claim 4, wherein a stopper means (109, 150, 110, 112) is provided at said movable platen (22) for holding said mold clamping unit (20) at said horizontal axis position, so that said tilting injection unit (60) when standing vertically on said machine base (100) is located between said stopper means (109, 150, 110, 112) and said rotation axis. A die casting machine according to claim 5, wherein said driving means is a piston-cylinder unit (101) rotatably mounted on said machine base (100) for actuating a piston rotatably connected to said stationary platen (21). A die casting machine according to claim 6, wherein a means is provided for positioning at least one mold core (10) relative to said mold when said mold is provided with said core (10) therein at said vertical axis position. A die casting machine according to claim 7, wherein said core positioning means comprises a product separating means (40) mounted to said stationary platen (21) or said stationary mold half (27) for driving axial pins (36) through pin holes formed in said stationary mold half (27) to push a cast or molded product after said movable mold half (28) is separated from said stationary mold half (27) and a means for actuating said product separating means (40) so that axial projections of said push pins (36) from said stationary mold (27) are maintained to thereby support said core (16) from below when provided in said mold at said vertical axis position. A die casting machine according to claim 8, comprising a mold core unit (42) outside said mold opposite to the side of said mold gate (31) for providing a second mold core (41) in said mold, which second core (41) is movable into said mold along a line perpendicular to said mold axis through a hole (34) formed by the parting faces (29), said stationary mold (27) having a recess (27a) formed in the inner surface at the mold gate side for receiving one end of said first mentioned core (10) while temporarily supported by said push pins (36), and said second core has a groove (44) formed to face the parting face of said movable mold (28) for receiving the opposite end of said first core (10) supported by said push pins (36) in cooporation with said recess (27a) when said second core (41) is moved from an outer position to an inner one, said first core (10) being clamped at said opposite end for completion of the provision of said first core (10) in said mold, after said projected pins (36) are withdrawn from an inner position to an outer one, by both said second core (41) and movable mold half (28) therebetween when said mold halves (27, 28) are joined, at said vertical axis position. A die casting machine according to claim 9, wherein said first core (10) is disintegratable and made of sand with a resin cover. A die casting machine according to any one of claims 4 to 10, wherein said tilting injection unit (60) comprise: a first piston-cylinder unit (61) for injecting the melt (74), a plunger rod (66) connected to said piston (64), a sleeve frame (70) connected to said casting sleeve (73), and a second piston-cylinder unit (68, 69, 70) where said sleeve frame (70) forms a movable cylinder and said cylinder of said first piston-cylinder unit (61) forms a stationary piston (68), for activating said sleeve frame (70) with said casting sleeve (73) to move upward relative to said first piston-cylinder unit (61) at said horizontal axis position so that said casting sleeve (73) communicates with said mold gate (31) for the upward injection.

Inventors: DANNOURA, SADAYUKI, UENO, TOYOAKI
Applicants: UBE INDUSTRIES, LTD.
Application year: 1988
Main classification: B22D17
IPC codes: B22D17