JPH02290659A - Vertical type injection apparatus - Google Patents

Abstract

PURPOSE:To surely separate a product from a biscuit at the prescribed position at the time of opening dies by specifying size of molten material passage between insert hole for lower die sleeve and die cavity and diameter of a pin fitting to this passage and also making reverse tapered hole widening downward of the lower part of the passage. CONSTITUTION:In a vertical type injection apparatus, the molten material passage 49 between the inner hole in the fixed sleeve 33 in which the cylindrical injection sleeve 47 in the lower die is inserted and the die cavity 8 is formed to smaller diameter than the inner hole diameter in the sleeve 47. Further, the outer diameter in the fitting part of the pin 63 fitted freely insertably to the molten material passage 49 is formed to a little smaller than the inner diameter of the molten material passage 49 and the pin 63 is supported as liftable on an upper die side and the lower side of the molten material passage 49 is made to the reverse tapered hole 49 widening downward. By this constitution, the molten material 67 is filled up into the cavity 8 from the injection sleeve 47 with a plunger tip and the pin 63 is made to project into the molten material 67 and the molten material 67 is caused to flow at every corners in the cavity 8. By this method, the product and the biscuit are always surely and easily cut off at the gate part 49a at the time of opening dies.

Description

[Detailed Description of the Invention] [Industrial Application Field] The invention relates to a vertical injection device that injects molten material into a mold cavity from directly below. [Prior Art] For example, vertical die-casting machines are often used to cast aluminum automobile disc foils because there is less gas entrainment during injection of molten metal. FIG. 3 is a schematic longitudinal cross-sectional view of the mold and injection device of this type of conventional die-casting machine. A lower mold 2 having a cylindrical convex portion is attached thereto, and a movable platen 3 that is supported by a mold clamping cylinder (not shown) and moves downward L has a low convex portion at the center. Upper mold 4 is installed. A plurality of cores 5 are inserted into the molds 2 and 4 so as to be movable horizontally from a position dividing the circumferential direction into two equal parts, and a piston of a cylinder 6 supported on the movable platen 3 side. rod 7
It is configured to move horizontally by moving forward and backward. A cavity 8 is formed by both the molds 2 and 4 and the closed core 5. Fixed platen 1
An injection sleeve 9 is inserted into and removed from below into the sleeve hole formed in the lower mold 2. A plunger tip 10 is moved back and forth into the injection sleeve 9 by an injection cylinder (not shown). They are fitted freely. 11 is the molten metal injected with the injection sleeve 9 pulled out from the sleeve hole. With the above configuration, when the plunger tip 10 is advanced after injecting the molten metal 11 into the injection sleeve and inserting it into the sleeve hole, the molten metal 11 is injected into the cavity 8, so that 1 liter of the molten metal is injected into the cavity 8. After solidifying and cooling, the movable platen 3 is raised to open the mold, and the core 5 is opened laterally, and the product solidified in the cavity is extruded by a product extrusion device (not shown) and released from the machine. Take it out.

The molten metal 11 inside the cavity 8 during such an injection operation
In order to explain the flow, the disk portion 8 of the cavity 8, which corresponds to the disk of the disk foil in FIG.
If a is schematically represented, it has a disk shape as shown in FIG.
If b is schematically represented, it has a cylindrical shape as shown in Figure 5. The molten metal 11 pushed up by the plunger tip IO flows radially through the disk portion 8a as shown by the arrow in FIG.
b hangs down by its own weight. FIG. 6 is a perspective view showing the state of the molten metal flowing in this manner, and as the molten metal 11 flowing in the above manner hangs down on the rim portion 8b, the temperature unevenness of the mold 2.4 and Uneven adhesion of mold release agent, mold 2
, 4. Scratches on the surface cause irregularities in flowability, and 6th
As shown by reference numeral 12 in the figure, the gas may be trapped in 1 liter of molten metal, so if filling is finished as it is, molten metal 11
This will entrain gas and create cavities in the molded product. If the cavity 8 is injected with the disc part 8a positioned on the L side, gas may be drawn in as described above.To avoid this, the cavity 8 is positioned so that the disc part 8a The rim part 8b should be on the lower side and the rim part 8b should be raised upwards, but in this case, the hub decorative surface of the product will be on the injection sleeve 9 side, and there will be a layer called a biscuit on this surface. Conventionally, molding has been unavoidably carried out with the disk portion 8a facing upward, since unnecessary molten metal solidification is attached and cutting it after molding impairs the aesthetic appearance of the decorative surface. [Problems to be Solved by the Invention] As described above, in the past, molding was performed with the disk portion 8a on the upper side, and therefore, in order to avoid the gas entrainment, injection must be performed at a relatively low speed. Not necessarily,
Not only does productivity decline, but for the reasons mentioned above, it is necessary to control the flow form of 1 liter of molten metal in the cavity 8 by the speed of the plunger tip 10 in order to stabilize the quality of the product. There was a problem that it could no longer be called control, and quality stability could not be measured. However, if the speed of the plunger tip 10 is used to control the injection speed, the injection speed will increase and the entrainment of the gas will increase. [Means for Solving the Problems] In order to solve these problems and scratches, the present invention makes the melt passage between the sleeve insertion hole of the lower mold and the mold cavity smaller than the inner diameter of the sleeve. The bottle is also formed to have a small diameter, and a bottle that is removably fitted into the melt passage and whose outer diameter at the fitting part is slightly smaller than the inner diameter of the melt passage can be moved up and down to the upper mold side. The lower side of the melt passage was formed into a tapered hole that widened downward. [Operation] When the plunger tip is raised by the injection cylinder, the molten material inside the sleeve is injected into the mold cavity through the molten material passage. Immediately before or after the end of injection, when the pin is lowered while applying upward force to the plunger tip and protrudes downward from the upper movable mold, the tip of the pin protrudes into the small diameter melt passage. When the pin is lowered, the melt in the melt passage near the vertical axis and in the small diameter part of the cavity is removed by the bottle and pushed into other parts of the cavity, so that the feeder action is effective. done,
The molten metal sufficiently spreads to every corner of the mold cavity, resulting in a dense product. When the melt solidifies in this state,
The solidified material in the small-diameter melt passage forms a thin-walled cylinder formed around the pin. Therefore, after the product has solidified, the bottle is raised and the mold is opened, and the product rises with respect to the upper movable mold. At this time, since the lower side of the melt passage is a tapered hole that widens downward, the vertical width of the thin cylindrical part is formed to be quite narrow, and the upper movable mold and As the product rises, the solidified material is reliably and easily severed from the thin-walled cylindrical portion, leaving the biscuit in the sleeve. [Example] This example shows an example in which the present invention is implemented in a mold opening/closing unit of a rotary die-casting machine. FIG. In these figures, the rotary die casting machine is equipped with a rotary table and three mold opening/closing units mounted at positions that divide the outer circumference into three equal parts in the circumferential direction. On the orbit of the rotating mold opening/closing unit, there are three work stations, consisting of a mold clamping/injection station, a product ejection station, and a mold cleaning/shaping agent application station, located at positions dividing the circumference into three equal parts. Each mold opening/closing unit is equipped with a mold, and each of the three stations performs mold clamping and injection, mold opening and product ejection, mold cleaning and mold cleaning. The mold release agent is sprayed, and the table stops every 120 degrees to carry out these operations.One rotation completes one cycle.The figure shows the mold clamping, one rotation, and one rotation. It shows the mold opening/closing unit and is shown in Figure 1.
On one side and below, a mold clamping device and an injection device (not shown) are installed. In the figure, the mold opening/closing unit 20 is equipped with a mounting plate 2l that is removably fixed on a rotary table (not shown), and a pair of mold opening/closing cylinders 22 erected on both left and right sides of this mounting plate 2l have hydraulic pressure. A flat wooden top plate 24 is fixedly supported at the working end of the piston rod 23 which moves up and down. As the piston rod 23 advances and retreats, the top plate 24 and the upper mold, which is a movable mold described later, are guided by four wooden guide rods (not shown) and moved up and down, thereby performing mold opening and mold matching. It is structured as follows. A sleeve support plate 26 of a lower mold, which is a fixed mold, is fixed to the mounting plate 2l, and the sleeve support plate 26 of the lower mold, which is a fixed mold, is indicated by the reference numeral 25 as a whole. A casting channel 49 for pouring molten metal in the vertical direction is formed at the center of the shaft.
an annular mold holder 30 which is fixed and held by a port 31 in contact with the lower surface and outer peripheral surface of the mold wooden body 32; The mold holder 30 is fixedly attached to the mold holder 30, and the sleeve support plate 26 fixedly holds the lower end of the fixed sleeve 33, which is disposed with its upper end surface in contact with the lower shaft center of the mold wooden body 32. did. The mold holder 30 is constructed by a plurality of cylinders 29 implanted in the sleeve support plate 26 and a push-up cylinder 89 consisting of a cylinder 90 and a piston 9l installed between the sleeve support plate 26 and the mold holder 30. The stroke is lifted so that it is separated from the sleep support plate 26. However, since there is usually no need to lift the mold holder 30, hydraulic pressure is applied to the chamber on the rod side of the push-up cylinder 89, so that the mold holder 30 and the mold wooden body 32 are This prevents it from floating up from the sleeve support plate 26. Therefore, it can be said that the mold holder 30 is substantially fixed to the sleeve support plate 26. 28 is a sleeve support plate 26
This is an annular core retaining ring fixed to the top surface with multiple bolts 27. 33 is a fixed sleeve formed in a stepped cylindrical shape, and is connected to the three members 26 , 30 .
The ring 34 is inserted into the sleeve hole formed in the sleeve support plate 26, and is prevented from coming off from the sleeve hole by a ring 34 screwed to the sleeve support plate 26. -M, on the bottom surface of the top frame 24, the entire number is 35.
A substrate 36 of an upper mold, which is a movable mold, is fixed, and the upper mold 35 has a support plate 38 integrally fixed to this substrate 36 by a plurality of ports 37, A mold holder 39 is fitted and fixed in the recessed hole 38a of this support plate 38, and a mold holder 39 is fitted and fixed in the recessed hole 39a of this mold holder 39.
It is formed by a molded wooden body 4L fixed with 40mm. Cylinder support plates 42 are fixed to the lower end flange portion of the support plate 38 at four equal intervals around the periphery. 44 is a core cylinder attached to each cylinder support plate 42, and a core 46 is fixed to the working end of the piston rod 45 of each core cylinder 44, respectively. Each core 46
In the state shown in FIG. 4, the movement is restricted by the core retaining ring 28, but when the lower surface of the mold 35 as a whole rises and exceeds the upper surface of the core retaining ring 28,
They are configured to open all at once in the radial direction when the piston rod 45 retreats. Also, when the four cores are closed as shown in Figure 1. A perfect circle is formed by the four inner peripheral surfaces. Then, the mold bodies 41 of the upper and lower molds are matched.
．． 32 and four closed cores 46 constitute a cavity 8 shown with the same reference numerals as in FIG. As is clear from a comparison between FIG. 1 and FIG.
is located at the bottom of the overall height of cavity 8. A cylindrical injection sleeve 47 supported via a block on the upper end surface of an injection cylinder (not shown) is inserted into and removed from the inner hole of the fixed sleeve 33. Branja 4 advances and retreats by
A plunger chip 48a serving as the head of No. 8 is fitted. Both sleeves 33 have the same diameter. The mold body 32 between the inner holes 33a, 47a of 47 and the cavity 8
A runner 49 is vertically provided at the axial center of the molten metal as a passage for the molten metal injected into the inner hole 33a and injected into the cavity 8 by the advancement of the plunger tip 48a.
This runner 49 is connected to the inner hole 3 formed near the cavity 8.
It is formed by a gate 49a, which is a cylindrical hole with a considerably smaller diameter than those of 3a and 47a, and a tapered hole 49b, which is formed near the inner hole 33a and widens downward. , which becomes the cosmetic surface of the product that solidifies in the cavity 8. Note that since the lower side of the melt passage, which is the runner 49, is formed into a tapered hole 49b, the vertical width of the gate 49a, which is the vertical portion, is formed to be relatively narrow. Outside the upper end of the annular rim portion 8b of the cavity 8 is a runner 50 formed in an annular shape concentric with the rim portion 8b.
is provided on the lower end surface of the mold holder 39, and the runner 50 and the rim portion 8b are communicated with each other through a plurality of radially formed gates 51. What is generally designated by the reference numeral 52 is a gas venting device for removing the gas in the cavity 8 to the outside of the machine during injection, and is located between one adjacent core 46 and is located between the upper mold 35 and the lower mold 25. This degassing device 52 is divided into a valve seat portion 53 and a cylinder portion 54. The valve seat part 53 is divided into a front side and a back side in FIG. 1, and is formed to open integrally with each core 46 on both sides. A link 57. 58 so as to be freely movable in the axial direction. This gas venting device 52 is a conventionally known cylinder type gas venting device, and includes a gas path 59 that communicates with the runner 50, and a valve 60 that opens and closes a valve seat at the end of the gas path 59. opens and gas is discharged by the pressure of the molten metal or a vacuum device, and the valve 60 is opened by the inertia of the molten metal or by an electric signal.
is constructed so that the valve is closed and the discharge of molten metal to the outside of the valve seat is blocked. Further, the cylinder portion 54 functions to ensure that the valve is closed and to hold the valve 60 in each open and closed position, and when the upper mold 35 is opened, the cylinder portion 54 moves out from the valve seat 53 by the operation of the cylinder 35 to open and close the valve. It rises together with the upper mold 35. Next, we will explain mold clamping and mold opening. Mold clamping is performed by lowering the top plate 24 from the mold matching state shown in FIG. 1 by a mold clamping cylinder (not shown) against the hydraulic pressure of the mold opening/closing cylinder 22, and the mold opening is performed when the mold clamping cylinder is withdrawn. Later, the mold opening/closing cylinder 22 is changed from the state shown in the figure.
This is done by moving the piston rod 23 forward, and the punch plate 24, upper mold 35, and gas venting device 52
etc. will rise together. When the mold is opened, the product solidified in the cavity 8 reaches the upper mold 35 and rises. Next, a description will be given of the feeder device that operates in the latter half of the injection process, the cutting device of the game 49a and the cutting device of the lunch 50 when the mold is opened, and the product extrusion device. A cylinder 61 for protruding a bottle is fixed to the center of the top plate 24, and its piston rod 62 is
It passes through the rod hole of the top plate 24 and projects downward. Reference numeral 63 is a round rod-shaped bottle that extends downward by having a screw hole screwed into the protruding screw portion of the piston rod 62,
For example, it is divided into three upper and lower stages and then joined together, and the diameter of the lower stage is slightly smaller than the diameter of the gate 49a. Note that the inner diameter of the gate 49a is, for example, 40 mm.
~60mm, the outer diameter of the bottle 63 is the gate 49a
For example, it is formed 1 to 5 mm smaller than the inner diameter of. This pin 63 is connected to a bearing 64 which is clamped and fixed to the substrate 36 and the support plate 38, a bearing 65 which is supported and fixed to the support plate 38 and the mold body 41, a mold wooden body 4l, and a mold. The cartridge 66 fixed to the wooden body 41 is pivotally supported in a shaft hole provided in each shaft hole, and as the piston rod 62 moves forward and backward with the hydraulic pressure of the cylinder 61, the pin 63 moves as shown by the solid line in FIG. It is configured to move up and down between the position and the two-dot chain line position. That is, when the pin 63 descends to the chain line position before the molten metal 67 in the cavity 8 solidifies, the bottle 63 removes the molten metal 67 and acts as a feeder, leaving a thin solidified molten metal 68 at the gate 49a. It is constructed so that the hole is penetrated through it. and,
As will be described later, the product and the biscuit 69 are separated by cutting the solidified molten material 68 when the mold is opened. In addition, pin 63
A cooling device with holes 71 for cooling water extending from the rear to the vicinity of the tip is provided inside the bottle 63, which cools the bottle 63 heated with molten metal and extends its life. When the feeder action is completed, the cooling water in the bottle 63 quickly cools the boss at the center of the disk portion 8a, which is relatively thick and difficult to cool, and the mold opens. It is designed to speed up the process, increase workability, and significantly shorten injection cycle time. Furthermore, a plurality of product extrusion cylinders 72 are fixed to the upper surface of the top plate 24, and an ejector plate 74 parallel to the top plate 24 is fixedly supported at the upper end of the piston rod 73. A plurality of pins 75 fixed to the plate 74 pass through holes in the top plate 24 and the substrate 36 and protrude downward, and then they are inserted into the extrusion plate 76 provided in the space of the support plate 38 so as to be movable up and down. It is screwed into the screw hole. Each extrusion bottle 77 is a plurality of extrusion bottles 77 whose heads are held by an extrusion plate 76 that is divided into two upper and lower parts. 78 is the mold holder 3
A hub extrusion plate 7 provided vertically movably in the space of 9.
9 and the upper end of the rim portion 8b, respectively, and when the product ejection cylinder 72 is operated after the mold is opened and the ejector plate 74 is lowered, the bottle 75 and the ejector plate 76 are brought into contact with each other.
, the extrusion pins 77, 78, the hub extrusion plate 79, and the disk portion 8a which is supported by the hub extrusion plate 79 and is also a hub portion.
The product is extruded downward from the cavity 8 through an extrusion bottle 80 that abuts on the extrusion pin 80 . The hub push-out plate 79 is guided by the guide pin 81 to move up and down, and is resiliently urged by the compression coil spring 82 to return to the raised position. Furthermore, a plurality of cylindrical stoppers 83 are provided in holes provided at positions dividing the lower end outer circumferential portion of the mold holder 39 into a plurality of equal parts in the circumferential direction, so that the holes can freely move forward and backward in the radial direction in FIG. The taper holes 83a provided in each stopper 83 are fitted with the tapered ends of the respective openings 7 and 85, which are suspended by their own weight from the extrusion plate 76, respectively. When the push-out plate 76 descends by a stroke indicated by the symbol a in FIG. 1, the push-out plate 76 and the rod 85 become one, and the rod 85 begins to descend, causing the stopper 83 to move outward due to the taper action. There is. In addition, the extrusion plate 7
The lower end of each extrusion bottle 86 is supported and suspended at a position that divides the outer circumference of the launcher 6 into a plurality of equal parts in the circumferential direction, and the lower end of each extrusion bottle 86 is in contact with the runner 50.
A circular projection 83b provided at 3 is removably inserted and seals the solidified molten metal in the runner 50, and after the stopper 83 retreats and the projection 83b comes out, the extrusion plate 76 roughly descends. The ejector bottle 86 is configured so that it begins to descend when it has descended by a stroke indicated by the reference numeral 2a in FIG. When the extrusion plate 76 starts to descend while the protrusion 83b of the stopper 83 is inserted, the product is extruded by the extrusion pins 78, 80 and cut by the gate 51, and an annular solidified product is formed inside the launcher 50. The object remains held by the protrusion 83b. After this, the stopper 83 moves with the above two strokes a, and the stopper 83 moves with the stroke 2a.
The solid matter inside the runner 50 is pushed out. 1 is a cylinder for regulating extrusion timing fixed to the upper surface of the top plate 24, and between the piston rod 88 at its upper limit and the ejector plate 74, the rod 85 is stroke a
The same gap a is provided, and the ejector plate 7
When the piston rod 4 descends and comes into contact with the piston rod 88, the descent is temporarily stopped by the control of a solenoid valve and the like, and then it descends again. In other words, this stop position is the position where the rod 85 starts to descend and the product is pushed out by a distance a, thereby preventing the lower runner 50 of the product from turning around and being pushed out. This eliminates the need to remove the lunch, which is difficult, and avoids damage to the product during removal. Next, the operation of the device configured as above will be explained.
The mold opening/closing unit 21, which has been sprayed with mold release agent and aligned at the upstream work station, is rotated by the rotation of the rotary table to the mold clamping/injection station and stopped, so that the top plate 24 is moved downward by the mold clamping cylinder. Mold clamping is performed by pressing . At the same time as mold clamping, the injection sleeve 47 into which the molten metal 69 was injected is fixed to the sleeve 3.
When the plunger tip 48 is moved forward, the molten metal 69 is injected into the cavity 8 and filled. In Figure 2, the solid line indicates the state where injection has completed. When the piston rod 62 of the pin ejecting cylinder 6l is hydraulically advanced just before or after the end of this injection, that is, before the molten metal 69 begins to solidify, the pin 63 descends and ejects from the cartridge 66, as shown in FIG. As shown by the two-dot chain line, the molten metal 69 in the gate 49a is thrust into the molten metal 69, and at this time, the protruding path of the pin 63 at the vertical axis center in the cavity 8 and the molten metal 69 in the gate 49a are removed by the pin 63. Since it flows into the cavity 8, the molten metal 69 acts as a riser and spreads to every corner of the cavity 8. In this state, the molten metal 69
However, since cooling water is flowing through the hole 7l inside the pin 63, the molten metal 69, which is the thickest part around the bottle 63 and is difficult to solidify, solidifies relatively quickly. The mold can be opened much faster. After a predetermined period of time, the product solidifies and becomes a product. After retracting the pin 63, the rotary table rotates 1200 times and the mold opening/closing unit 21 stops at the product take-out station.The piston rod 23 moves forward with the hydraulic pressure of the mold opening/closing cylinder 22, and the top plate 24 rises. Therefore, the entire upper mold 35 integrated with this rises and the mold is opened. In this case, as mentioned above, gate 4
Since the pin 63 was inserted into the pin 9a and the diameter difference between the pin 63 and the pin 49a was small, a thin cylindrical solidified molten metal was formed around the part where the pin 63 was located. Further, a tapered hole 49b is provided just below the gate 49a.
The vertical width of the thin cylindrical portion of the solidified molten metal formed between the pin 63 and the gate 49a is extremely narrow, and the solidified molten metal in the tapered hole 49b has a small diameter at the top. Since the product lOO in the cavity reaches the upper mold 35 and rises when the mold is opened, the biscuit 101 is prevented from falling out upwards by the fixing sleeve 3.
3 and the tapered hole 49b, the thin-walled cylindrical portion is easily cut, and the mold 35 rises together with the mold 35. After the mold is opened in this manner, when the piston rod 73 is moved backward by the hydraulic pressure of the product extrusion cylinder 72, the top plate 24 begins to descend. As a result, first the extrusion plate 76
The extrusion bins 77 and 78 integrated with the machine descend, and the product 100 whose tips come into contact with each other begins to be extruded from the cavity 8. At this time, as shown in FIG. 2, the projection 83b of the stopper 83
is engaged with the concave hole of the runner 50, so even if the product lOO is pushed out and descends, the launch 50 remains as it is, and the product 1
00 and the runner 50 are separated from the gate 5l. When the top plate 24 descends by the stroke a, it comes into contact with the upper end of the piston rod 88 of the cylinder 87, so the descending stops once, and after a predetermined timing, begins to descend again. When the descent is restarted, the push-out plate 76 and the rod 85 are integrated by the stroke a, so the rod 85 also descends. As the rod 85 descends, its lower end pushes the tapered hole 83a of the stopper 83, and the taper action causes the stopper 83 to retreat outward, so that the protrusion 83
b comes out of the concave hole of the runner 50. Top plate 24
continues to descend and further descends by stroke a, totaling 2
When a is lowered, the extrusion plate 76 and the extrusion bottle 80 are integrated, so the extrusion pin 86 also begins to descend and the annular runner 50 that is in contact with its lower end is extruded, as shown in Fig. fjS5 (e
) indicates this state. Next, an extrusion device (not shown) for extruding biscuits is moved between the two opened molds, and its piston rod is advanced to extrude the biscuits. The extrusion device for extruding biscuits is composed of a cylinder, a piston rod facing downward, and a moving device that moves the cylinder between the upper and lower mold bodies 41, 32 that open the mold and the lateral outside. The upper end of the cylinder is brought into contact with the lower end surface of the pin 63 retracted into the upper mold body 41, and the tip of the piston rod provided on the lower end is inserted into the lower mold body 32. By inserting the biscuit into the small diameter part and pushing down on the top of the biscuit, the biscuit falls downward. In the case of the product 100 taken out from the mold in this way, in the case of a disc foil, the lower side of the hub in the figure becomes the decorative surface, but since it only has a thin cylindrical solidified material attached thereto,
This is easy to remove, and the aesthetic appearance is not compromised even after removal. Although this embodiment shows an example in which the present invention is applied to a rotary die-casting machine, it goes without saying that the invention can also be applied to a stationary die-casting machine. It can also be applied to injection molding machines for plastics. [Effects of the Invention] As is clear from the above description, in the vertical injection device according to the present invention, the melt passage between the sleeve insertion hole of the lower mold and the mold cavity is made smaller than the inner diameter of the sleeve. The pin is formed to have a small diameter, and the pin, which is inserted into and removed from the molten material passage and whose outer diameter is slightly smaller than the inner diameter of the molten material passage, can be moved up and down toward the upper mold side. By making the lower side of the melt passage a tapered hole that expands downward, a thin solidified substance is formed in the melt passage by the action of the pin, and a downward Since there is a tapered hole that widens to , it is possible to provide a relatively narrow gate portion in the vertical direction only in the upper part in contact with the cavity in the melt passage, so that the vertical width of the thin solidified material can be As a result, the pin can be easily advanced to at least the inside of the gate portion each time, and the cutting distance of the gate portion can be shortened. When opening the mold, the product and biscuit can always be separated easily and reliably at a predetermined point. In addition, it becomes possible to mold a disc foil with a lower hub portion without compromising the aesthetic appearance of the decorative surface.
There is no gas entrainment, which greatly improves the quality of the product, and there is no need to slow down the ejection speed to avoid gas entrainment, which improves productivity. In addition, since the lower side of the melt passage is made into a tapered hole that spreads downward,
After opening the mold, the biscuits in the fixed sleeve etc. can be easily pushed down and taken out. Further, since there is a gap between the bottle and the melt passage, the bottle does not hit or come into contact with the mold or the inner peripheral surface of the melt passage, and the life of the pin is extended.

Furthermore, the bottle eliminates the molten metal in the pin protrusion path and small diameter part at the vertical axis of the cavity, which acts as a feeder action and spreads the molten metal to every corner of the cavity, improving the quality of the product. It is possible to easily obtain a dense, high-strength product with no cavities. In particular, in the present invention, a pin with a diameter slightly smaller than the diameter of the melt passage can be advanced into the melt passage, so that the melt passage does not restrict the advancement limit of the bottle, and the pin is Even if it enters the molten material passage, it can move forward sufficiently, and the riser effect acting on the molten material in the cavity becomes thicker accordingly. Of course, this feeder operation can be performed before the injection operation is completed, but in that case, the injection pressure applied to the molten metal by the plunger tip passes through the narrow gap around the pin and acts on the molten metal in the cavity. Therefore, sufficient injection LiE
The force is maintained until the end of the injection operation, making it possible to obtain a more dense product.

In addition, after injection, a pin with a diameter slightly smaller than the diameter of the melt passage is advanced into the melt passage whose diameter is smaller than the inner diameter of the injection sleeve, and a thin molten solidified product is formed between them. Since the thin-walled part quickly cools and solidifies, the amount of cooling of the molten metal in the product phase 5 decreases, and even when the thick-walled biscuit part in the stationary sleeve and injection sleeve has not completely solidified, the cavity If the product part, which is comparatively 1 ton thick, is finished in m II4 L, the mold can be opened immediately. As a result, cycle times are reduced and
From this point of view as well, productivity is improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. Fig. 3 is a schematic vertical cross-sectional view of the mold and injection device, Fig. 4 is a schematic diagram of the disk section, Fig. 5 is a schematic diagram of the rim section, and Fig. 6 is an explanatory diagram showing the flow state of the molten metal. 8...Cavity, 25...
...Lower mold, 5...L mold, 33
．． 47... Sleeve, 9... Runway (melt passage), 9a... Gate, 49b... Taper part,
l...Cylinder for pin protrusion, 2...
Piston rod 7, 63...bin. Figure 3 Patent Applicant Ube Industries Co., Ltd. Figure 4'$5 Figure'$6

Claims (1)

[Claims] The molten material passage between the sleeve insertion hole of the lower mold and the mold cavity is formed to have a smaller diameter than the inner hole diameter of the sleeve, and it is fitted into this molten material passage so as to be freely inserted and removable, and the outside of the fitting part is A vertical injection device in which a pin having a diameter slightly smaller than the inner diameter of the melt passage is supported on the upper mold side so as to be able to move up and down, and the lower side of the melt passage is formed into a tapered hole expanding downward.