JP2572667B2 - Vertical injection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vertical injection device for injecting a melt into a mold cavity from directly below.

2. Description of the Related Art For example, casting of aluminum disk wheels for automobiles is often performed by a vertical die casting machine because of a small amount of gas entrainment during injection of molten metal. FIG. 5 is a schematic sectional view of a mold and an injection device of this type of conventional die casting machine. Referring to FIG. 5, a fixed platen 1 fixed on a machine base has a central portion. A lower mold 2 having a cylindrical convex portion is mounted on a movable platen 3 which moves up and down while being supported by a mold clamping cylinder (not shown). The mold 4 is mounted. Reference numeral 5 denotes a plurality of cores movably inserted in the horizontal direction from a position dividing the circumferential direction into two halves between the two dies 2 and 4, and a piston of a cylinder 6 supported on the movable platen 3 side. The rod 7 is configured to reciprocate in the horizontal direction by reciprocation.
A cavity 8 is formed by the two dies 2 and 4 and the closed core 5. An injection sleeve 9 is provided in a sleeve hole formed in the fixed platen 1 and the lower mold 2.
The plunger tip 10 is removably inserted into the injection sleeve 9 by an injection cylinder (not shown). 11
Is a 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 the molten metal 11 is injected into the injection sleeve and inserted into the sleeve hole, the molten metal 11 is injected into the cavity 8, so that the molten metal 11 is After being solidified and cooled, the movable platen 3 is raised, the mold is opened, the core 5 is opened to the side, and the solidified product in the cavity is extruded by a product extruder (not shown) and the machine is extruded. To take out.

The molten metal 11 in the cavity 8 in such an injection operation
In order to explain the flow of the disk, the disk portion 8a of the cavity 8 which is the disk equivalent portion of the disk wheel in FIG.
6 is a disk shape as shown in FIG. 6, and a rim portion 8b of the cavity 8 which is a rim equivalent portion is a cylindrical shape as shown in FIG. is there.
The molten metal 11 pushed up by the plunger tip 10 flows radially through the disk portion 8a as shown by the arrow in FIG. 6, and then hangs down the rim portion 8b by its own weight as shown by the arrow in FIG. FIG. 8 is a perspective view showing the state of the molten metal flowing in this manner. The molten metal 11 flowing as described above hangs down the rim portion 8b, and the temperature unevenness of the molds 2, 4 at this time is reduced. Since unevenness of the release agent and flaws on the surfaces of the molds 2 and 4 cause unevenness in the flow of the molten metal, gas may be confined by the molten metal 11 as shown by reference numeral 12 in FIG. At the end, the molten metal 11 entrains the gas to form a nest.

As described above, when the cavity 8 is injected with the disk portion 8a positioned on the upper side, the gas may be engulfed as described above. What is necessary is just to make the rim portion 8b rise upward from now on, and the hub decorative surface of the product becomes the injection sleeve 9 side, and unnecessary melt solidified material called biscuit is provided on this surface. Is attached, and cutting after molding will impair the aesthetic appearance of the decorative surface. Conventionally, molding has been performed with the disk portion 8a facing upward.

[Problems to be Solved by the Invention] As described above, in the related art, since the molding is performed with the disk portion 8a facing upward, the injection is performed at a relatively low speed in order to avoid the entrainment of the gas. In addition to reducing the productivity, the flow form of the molten metal 11 in the cavity 8 must be controlled at the speed of the plunger tip 10 in order to stabilize the quality of the product. However, there is a problem that the control cannot be said to be controllable for the above-mentioned reason, and the quality cannot be stabilized. However, if the speed is controlled by the speed of the plunger tip 10, the injection speed increases and the entrainment of the gas increases.

Further, the conventional device is not sufficient as a device capable of easily obtaining a dense product and separating the biscuit remaining in the injection sleeve after the injection from the product and easily removing the biscuit.

Means for Solving the Problems In order to solve such problems, in the present invention, at least the mold cavity in the melt passage between the injection sleeve insertion hole of the lower mold and the mold cavity is provided. Is formed in a small-diameter portion smaller than the inner hole diameter of the injection sleeve, and a pin provided so as to be freely inserted into and removed from the small-diameter portion of the melt passage is supported on the upper mold side so as to be able to move up and down, and take out the biscuit. In order to be able to perform easily, it can be inserted between the opened upper mold and the lower mold, the upper end side of which is in contact with the lower end surface of the upper mold, and the piston rod provided on the lower end side. A biscuit extruding device was provided which was provided so that its tip could be inserted into the small diameter portion of the lower mold.

[Operation] When the plunger tip is raised by the injection cylinder, the melt in the injection sleeve is injected into the mold cavity via the melt passage. Immediately before or immediately after the end of injection, when the plunger tip is lowered while applying a force in the upward direction to project downward from the upper movable mold, the protruding tip of this pin is inserted into the small-diameter melt passage. When the pin descends, the melt in the melt passage near the vertical axis in the cavity and in the small-diameter portion is removed by the pin and pushed into another portion in the cavity. The molten metal spreads to every corner of the mold cavity, and a dense product can be obtained.

When the melt is solidified in this state, the solidified material in the melt passage of the small diameter portion becomes a thin inner cylindrical shape formed around the pin. Then, after solidifying the product, raising the pin and then opening the mold, the product rises with respect to the upper movable mold, and the thin cylindrical solidified product is left from the thin cylindrical portion while leaving a biscuit in the injection sleeve. Easy and reliable cutting.

Next, the product is extruded from the opened upper mold, taken out of the machine, and the injection sleeve is moved laterally away from the lower mold and the fixed platen. It is inserted between the lower molds and supplies a pressure fluid to the chamber on the head side of the cylinder. Then, first, the upper end of the cylinder is brought into contact with the lower end of the upper mold, and then the tip of the piston rod provided at the lower end is charged into the small-diameter melt passage of the lower mold, and The biscuit remaining on the lower side is pushed down.

[Embodiment] This embodiment shows an example in which the present invention is applied to a mold opening / closing unit of a rotary die casting machine. FIG. 1 is a longitudinal sectional view of the mold opening / closing unit in which the invention is implemented, and FIG. FIGS. 3 and 4 are explanatory views of the operation of the present apparatus.

In these figures, the rotary die casting machine
It has a rotary table and three sets of mold opening / closing units mounted at positions that divide the outer periphery into three equal parts in the circumferential direction. The three work stations including a mold clamping / injection station, a product removal station, and a mold cleaning / release agent application station are respectively disposed at positions that divide the circumferential direction into three equal parts. A mold is mounted on each mold opening / closing unit. At each of the three stations, mold clamping and injection, mold opening and product removal, and cleaning of the mold and spraying of a release agent are performed. The operation is stopped at every rotation of the table 120 °, and these operations are performed. One rotation completes one cycle. The figure shows the mold opening / closing unit stopped at the mold clamping / injection station, and a mold clamping device and an injection device (not shown) are arranged above and below in FIG.

In the figure, the mold opening / closing unit 20 includes a mounting plate 21 detachably fixed on a rotary table (not shown), and a hydraulic pressure of a pair of mold opening / closing cylinders 22 erected on both right and left sides of the mounting plate 21. A horizontal plate-shaped top plate 24 is fixedly supported at the working end of the piston rod 23 that moves up and down. When the piston rod 23 retreats, the top plate 24 and an upper mold, which is a movable mold described later, are guided by four guide rods (not shown) to move up and down, and mold opening and mold matching are performed. It is configured as follows. A lower mold sleeve support plate 26, which is a fixed mold generally denoted by reference numeral 25, is fixed to the mounting plate 21, and the lower mold, which is a fixed mold,
The upper surface forms a part of the surface of the mold cavity 8, and has a mold body 32 having a vertical casting path 49 for molten metal casting at an axial center portion.
And an annular mold holder 30 holding the mold body 32 fixed by bolts 31 in contact with the lower surface and the outer peripheral surface of the mold body 32, and fixing the mold holder 30 by contacting the lower surface of the mold holder 30 It was installed as possible. It is constituted by a sleeve support plate 26 to which a lower end portion of a fixed sleeve 33 which is arranged so that an upper end surface thereof is in contact with a lower axis portion of the mold main body 32 is fixed. The mold holder 30 includes a plurality of guide pins 29 implanted on the sleeve support plate 26, and a cylinder 90 mounted between the sleeve support plate 26 and the mold holder 30.
And a push-up cylinder 89 composed of a piston 91 so as to be lifted up by a small stroke so as to be separated from the sleeve support plate 26. However, normally, since it is not necessary to lift the mold holder 30, operating hydraulic pressure is applied to the chamber on the rod side of the push-up cylinder 89, and the mold holder 30 and the mold body 32 are sleeved when the mold is opened. It does not float from the support plate 26. Therefore, it can be said that the mold holder 30 is substantially fixed to the sleeve support plate 26. 28
Is an annular core stopper ring fixed to the upper surface of the sleeve support plate 26 with a plurality of bolts 27. Reference numeral 33 denotes a stepped cylindrical fixing sleeve, which is a three-member lower mold 2
It is inserted into the sleeve holes formed in 6, 30, and 32, and is prevented from coming out of the sleeve holes by a ring 34 screwed to the sleeve support plate 26.

On the other hand, on the lower surface of the top frame 24, a substrate 36 of an upper mold which is a movable mold generally indicated by reference numeral 35 is fixed,
The upper mold 35 is fixedly attached to the substrate 36, a support plate 38 having a substantially octagonal shape in plan view integrally fixed thereto with a plurality of bolts 37, and a recess 38a of the support plate 38. Mold holder 39
And the bolt 40 is fitted into the concave hole 39a of the mold holder 39.
And the mold main body 41 fixed by the above. Support plate 38
The cylinder support plate 42 is fixed to the lower end flange portion at four locations around it at equal intervals. Reference numeral 44 denotes a core cylinder mounted on each cylinder support plate 42, and a core 46 is fixed to a working end of a piston rod 45 of each core cylinder 44. The movement of each core 46 is restricted by the core stopper ring 28 in the state shown in FIG.
When the lower surface of the upper die 35 rises above the upper surface of the core stopper ring 28 due to the rise of the entire upper die 35, the piston rod 45 is retracted and simultaneously opened in the radial direction. When the four cores are closed as shown in FIG. 1, a perfect circle is formed by the four inner peripheral surfaces. The upper and lower mold bodies 41 and 32 and the closed four cores 46 form the cavity 8 indicated by the same reference numerals as in FIG. First
As is clear from the comparison between FIG. 5 and FIG. 5, in the present apparatus, the cavity 8 is turned upside down as compared with the conventional case, and the disk portion 8a is located below the entire height of the cavity 8. .

A cylindrical injection sleeve 47 supported via a block at the upper end surface of an injection cylinder (not shown) is inserted into the hole of the fixed sleeve 33 so as to be freely inserted and removed. Plunger 48 going forward and backward
The plunger tip 48a as the head of the head is fitted. Inner holes 33, 47a of both sleeves 33, 47 having the same diameter
And a runner 49 as a passage for molten metal injected into the inner hole 33a and injected into the cavity 8 by the advance of the plunger tip 48a.
Are provided in the vertical direction. The runner 49 has a gate 49a as a cylindrical hole having a considerably smaller diameter than the inner holes 33a and 47a formed near the cavity 8 and a tapered hole 49b formed downward and formed near the inner hole 33a. The lower end surface of the disk portion 8a which is formed and continues to the gate 49a serves as a decorative surface of a product solidified in the cavity 8. Since the lower side of the melt passage, which is the runner 49, is formed as a tapered hole 49b, the vertical width of the gate 49a, which is a vertical portion, is relatively narrow.

Outside the upper end of the annular rim 8b of the cavity 8 is a rim
A runner 50 formed in an annular shape concentric with 8b is provided on the lower end surface of the mold holder 39. The runner 50 and the rim portion 8b are communicated by a plurality of radially formed gates 51. Numeral 52 indicates the cavity 8 at the time of injection.
A degassing device for evacuating gas inside the device, which is located between one adjacent core 46 and arranged between an upper mold 35 and a lower mold 25; 52 is divided into a valve seat 53 and a cylinder 54. And the valve seat
53 is divided into a front side and a paper back side in FIG. 1 and is formed so as to open integrally with each of the cores 46 on both sides, and a cylinder portion 54 is pivotally attached to the support plate 38. A piston rod 56 of the degassing cylinder 55 is formed to be movable in the axial direction via links 57 and 58. This degassing device
Reference numeral 52 denotes a conventionally known cylinder type gas venting device, which is provided with a gas passage 59 communicating with the runner 50 and a valve 60 for opening and closing a terminal valve seat thereof. Gas is exhausted by the pressure or evacuation device,
The valve 60 is closed by the inertia force or the electric signal of the molten metal, and the discharge of the molten metal to the outside of the valve seat is shut off. Also,
The cylinder portion 54 functions to ensure that the valve is closed and to hold the valve 60 at each of the open and closed positions. When the upper mold 35 is opened, the cylinder 35 retreats from the valve seat portion 53 by the operation of the cylinder 35 to permit opening and closing. And it rises with the upper mold 35.

Next, mold clamping and mold closing will be described. The mold clamping is performed by lowering the top plate 24 against the oil pressure of the mold opening / closing cylinder 22 by a mold clamping cylinder (not shown) from the mold matching state shown in FIG. 1, and the mold opening cylinder is retreated. Thereafter, the piston rod 23 of the mold opening / closing cylinder 22 is advanced from the state shown in the figure, and the top plate 24, the upper mold 35, the degassing device 52 and the like are integrally raised. Then, the product solidified in the cavity 8 reaches the upper mold 35 by the mold opening and rises.

Next, a feeder that operates in the latter half of the injection, a cutting device for the gate 49a, a cutting device for the runner 50, and a product pushing device when the mold is opened will be described.

A pin projecting cylinder 61 is fixed to the center of the top plate 24, and its piston rod 62 projects downward through a rod hole of the top plate 24. Reference numeral 63 denotes a round bar-shaped pin which is screwed into a projecting screw portion of the piston rod 62 and extends downward. For example, the pin is divided into three stages, upper and lower, and joined together. The diameter is slightly smaller than the diameter of 49a. When the inner diameter of the gate 49a is, for example, 40 to 60 mm, the outer diameter of the pin 63 is, for example, 1 to 5 mm from the inner diameter of the gate 49a.
It is formed small. The pins 63 are connected to the substrate 36 and the support plate.
The bearing 64 is fixed to the support plate 38, the support plate 38, the bearing 65 fixed to the support plate 38 and the mold body 41, the mold body 41, and the cartridge 66 fixed to the mold body 41, respectively. The piston rod 62 is retracted by the hydraulic pressure of the pin projecting cylinder 61 so that the pin 63 moves between the solid line position and the two-dot chain line position in FIG. It is configured to move up and down. That is, when the pin 63 is lowered to the dashed line position before the molten metal 67 in the cavity 8 is solidified, the pin 63 removes the molten metal 67 and acts as a feeder, while leaving a thin molten solidified material 68 at the gate 49a. The hole is configured to penetrate. And, as will be described later, the product and the biscuit 69
Separated by 68 cuts. A cooling device having a cooling water hole 71 extending from the rear to the vicinity of the tip is provided inside the pin 63, and the pin 63 heated by the molten metal is provided.
In order to prolong the life of the disk 8a, when the feeder operation is completed, on the contrary, by the action of the cooling water in the pin 63, the center of the disk portion 8a, which is relatively thick and hard to cool, The boss portion is cooled so that the injection cycle time can be considerably shortened, and workability and productivity can be increased.

Further, a plurality of product extrusion cylinders 72 are fixed on the upper surface of the top plate 24,
At the upper end of 73, an ejector plate 74 parallel to the top plate 24 is fixedly supported. A plurality of pins 75 fixed to the ejector plate 74
After projecting downward through a hole between the support plate 38 and the base plate 36, it is screwed into a screw hole of an extruding plate 76 movably provided in the space of the support plate 38. Extruded plate 76 divided into upper and lower two
Each extruding pin 7 with its head sandwiched and hanging down
7, 78 have a lower end abutting on a hub extruding plate 79 movably provided in the space of the mold holder 39 and an upper end of the rim portion 8b, respectively. When the ejector plate 74 moves down and the ejector plate 74 descends, the pin 75, the pushing plate 76, the pushing pin 77, 78, the hub pushing plate 79, and the pushing supported by the hub pushing plate 79 and abutting on the disk portion 8a which is also the hub portion. The product is configured to be pushed downward from the cavity 8 via the pin 80. The hub extrusion plate 79
Is moved up and down by being guided by the guide pin 81, and resiliently returned by the compression coil spring 82 to the ascending position.

Further, a plurality of stoppers 83 formed in a columnar shape are provided at positions provided at positions where the outer periphery of the lower end of the mold holder 39 is equally divided into a plurality of parts in the circumferential direction. Mated and tapered holes provided in each stopper 83
The tapered ends of the rods 85 suspended from the extruded plate 76 by their own weights are engaged with 83a. And the extruded plate 76
Is lowered by the stroke indicated by reference character a in FIG. 1, so that the pushing plate 76 and the rod 85 become integral with each other, and the rod 85 starts to move downward, so that the stoppers 73 are simultaneously moved outward by a taper action. In addition, the lower end of each of the extruded pins 86 supported and suspended at a position that equally divides the outer peripheral portion of the extruded plate 76 in the circumferential direction is in contact with the runner 50,
A circular projection 83b provided on the stopper 83 in the concave hole of the runner 50
Is inserted so as to be freely inserted and removed, and seals the solidified molten metal in the runner 50. After the stopper 83 retreats and the projection 83b comes off, the extruding plate 76 further descends and is indicated by reference numeral 2a in FIG. When the stroke is lowered by the stroke, the push pin 86 is configured to start lowering. When the extruding plate 76 starts to descend while the projection 83b of the stopper 83 is inserted, first, the product is extruded by the extruding pins 78 and 80, cut by the gate 51, and the annular solidified material is set in the runner 50. Is projection 83
Retained in b. Thereafter, the stopper 83 moves at the stroke a as described above, and the runner 50 moves at the stroke 2a.
The solids inside are extruded.

1 is a cylinder for regulating the extrusion timing fixed to the upper surface of the top plate 24. The cylinder 85 is located between the piston rod 88 and the ejector plate 74 at the upper limit. When the ejector plate 74 descends and comes into contact with the piston rod 88, the descending stops once and then descends again by the control of an electromagnetic valve or the like. That is, this stop position is the lowering start position of the rod 85 and the position where the product is extruded by only a, so that the runner 50 does not wrap around and be extruded below the product. This eliminates the need for difficult runner removal work, thereby avoiding product damage during removal.

Between the upper mold 35 and the lower mold 25 that have opened the mold, and
The shaft core portion was provided so that an extruder 100 for extruding a biscuit for pushing down a biscuit 101 remaining under the lower mold 25 and in the gate 49a when the mold was opened was provided. As shown in FIG. 4, the extruder 100 for extruding a biscuit mold opens a cylinder 102, a rod 104 provided above the cylinder 102, a piston rod 103 facing downward, and the cylinder 102. The upper and lower mold bodies 4 are configured by a moving device 105 for moving between the upper and lower mold bodies 41 and 32 and the side outside.
1 is brought into contact with the lower end surface of the pin 63 retracted into the lower die body 3 with the tip end of the piston rod 103 provided on the lower end side.
The biscuit 101 is inserted into the small diameter portion which is the gate 49a of 2
The biscuit is pushed down by pressing down on the upper surface of the biscuit.

Next, the operation of the device configured as described above will be described. The mold opening / closing unit 21, which has been sprayed with the mold release agent at the upstream work station and has been mold-set, circulates to the mold-clamping / injection station by rotation of the rotary table and stops. The mold is clamped by pressing. When the injection sleeve 47 in which the molten metal 69 is injected at the same time as the mold clamping is inserted into the inner hole of the fixed sleeve 33 and joined, and the plunger tip 48 is advanced, the molten metal 69 is injected into the cavity 8 and filled.
The state shown by the solid line in FIG. 2 indicates the end of the injection.

Immediately before or immediately after the end of the injection, that is, before the molten metal 69 does not start to solidify, when the piston rod 62 of the pin projecting cylinder 61 is advanced hydraulically, the pin 63 descends and projects from the cartridge 66, and FIG. As shown by a two-dot chain line, the molten metal 69 in the gate 49a is pierced. Since the molten metal 69 flows into the cavity 8, it acts as a pushing field, and the molten metal 69 spreads to every corner of the cavity 8.

In this state, the molten metal 69 starts to solidify, but since cooling water is flowing through the hole 71 inside the pin 63, the molten metal 69 around the pin 63 where the thickest part is hard to solidify is relatively small. It solidifies quickly, and the mold can be opened earlier.

After a predetermined time from the riser, solidification is finished to produce a product. Then, after retracting the pin 63, when the rotary table rotates 120 ° and the mold opening / closing unit 21 stops at the product removal station, the piston rod 23 moves forward by the hydraulic pressure of the mold opening / closing cylinder 22, and the top plate 24 rises. The upper mold 35 as a whole is lifted and the mold is opened. In this case, as described above, the pin 63 is inserted into the gate 49a, and the diameter difference from the gate 49a is small, so that the pin 63 is located, and a thin cylindrical solidified molten material is formed around the portion. The gate is formed
A taper hole 49b is provided immediately below 49a, and the pin 63
The vertical width of the thin-walled cylindrical portion of the solidified molten material generated between the gate and the gate 49a is extremely narrow, and the solidified molten material in the tapered hole 49b has a small diameter at the top so that it does not escape upward. Therefore, when the mold is opened, the product in the cavity that reaches the upper mold 35 and rises is easily cut from the thin cylindrical portion while leaving the biscuit 101 in the fixed sleeve 33 and the tapered hole 49b. , Rise with the upper mold 35.

After the mold is opened in this manner, when the piston rod 73 is retracted by the hydraulic pressure of the product extrusion cylinder 72, the top plate 24 starts to descend. As a result, first, the extrusion pins 77 and 78 integrated with the extrusion plate 76 descend, and the product with which the tip abuts starts to be extruded from the cavity 8. At this time, since the projection 83b of the stopper 83 is engaged with the concave hole of the runner 50, as shown in FIG.
The product and the runner 50 are separated from the gate 51 while 50 remains as it is. When the top rate 24 drops by the stroke a, the top rate 24 comes into contact with the upper end of the piston rod 88 of the cylinder 87, so that the lowering stops once and then starts lowering again after a predetermined timing. When the descent is restarted, the push plate 76 and the rod 85 are integrated by the stroke a, so that the rod 85 is also lowered. The lower end of the rod 85 pushes the taper hole 83a of the stopper 83, and the stopper 83 is moved outward by the taper action.
Get out of the concave hole. When the top plate 24 continues to descend and further descends by the stroke a, and the total descends by 2a, the push-out plate 76 and the push-out pin 80 become integral with each other, so that the push-out pin 86 also starts to descend, and the lower end thereof is in contact with the annular shape. The runner 50 is extruded. FIG. 3 shows this state.

At this time, the upper portion of the injection sleeve 47 has been moved down to the horizontal hot water supply position after being lowered and separated from the fixed sleeve 33. The biscuit 101 remains under the mold body 32, which is a part of the lower mold 25, and in the tapered hole 49b of the gate 49a.

Next, as shown in FIG. 4, the extruder 100 is moved between the opened molds and pressurized fluid is supplied to the head side chamber of the cylinder 102. The upper end surface contacts the lower end surface of the pin 63, while the piston rod 103 moves downward. As a result, the biscuit 104 is pushed down by the action of the piston rod 103 and is pushed down. This biscuit 101 is received below and taken out of the machine. When the biscuit 101 has been extruded, the cylinder 102
The cylinder 102 and the piston rod 103 are returned to their original positions, and then the moving device 105 is supplied.
To move the entire extruder 100 for extruding a biscuit out of the machine.

In the case of a disk wheel, the product taken out of the mold in this manner has a decorative surface on the lower side of the hub in the figure, but only a thin cylindrical solidified material is attached here. Is easy to remove, and does not impair the aesthetic appearance even after the removal.

Although the present embodiment shows an example in which the present invention is applied to a rotary die casting machine, it goes without saying that the present invention can also be applied to a stationary die casting machine. Further, the present invention can be applied to an injection molding machine for plastics.

[Effects of the Invention] As is clear from the above description, according to the present invention,
In the vertical injection device, at least the mold cavity near the melt passage between the injection sleeve insertion hole of the lower mold and the mold cavity is formed in a phase diameter portion smaller than the inner hole diameter of the injection sleeve. The pin, which can be inserted into and removed from the small-diameter portion of the melt passage, is supported on the upper mold side so as to be able to move up and down. Only a thin solidified material is formed there, and the product and biscuit can be easily separated at the time of deployment, and as a result, it is possible to mold a disk foil with a lower hub part without impairing the aesthetic appearance. Therefore, the quality of the product is greatly improved without the entrainment of gas, and the injection speed does not need to be reduced to avoid entrainment of gas, so that the productivity is improved. Furthermore, the pin eliminates the protruding path of the pin at the center of the longitudinal axis of the cavity and the molten metal in the small-diameter portion. As a result, this acts as a feeder, and the magnetic field spreads to every corner of the cavity, and contains gas inside. Not get a precise product, the product quality is improved.

Further, the upper mold can be inserted between the opened upper mold and the lower mold, and the upper end is brought into contact with the lower end surface of the upper mold, and the tip end of the piston rod provided at the lower end is connected to the lower mold. Since the biscuit pushing device provided so as to be able to be inserted into the small diameter portion is provided, the biscuit remaining on the lower side of the lower mold or in the gate can be easily pushed down and taken out.

[Brief description of the drawings]

1 to 4 show one embodiment of the present invention.
1 is a longitudinal sectional view, FIG. 2 is an enlarged view of a part of FIG. 1, and FIG.
FIG. 4 and FIG. 4 are longitudinal sectional views for explaining the operation state.
5 to 8 illustrate an example of a conventional device similar to the present invention. FIG. 5 is a schematic longitudinal sectional view of a mold and an injection device, FIG. 6 is a schematic diagram of a disk portion, FIG. 7 is a schematic diagram of the rim portion, and FIG. 8 is an explanatory diagram showing a flow state of the molten metal. 8 ... cavity, 25 ... lower mold, 35 ... upper mold, 47 ... injection sleeve, 49 ... runner, 49a ... gate, 61 ... cylinder for pin projection, 62 ... piston rod , 63… pin, 100… extrusion device for biscuit extrusion, 101… biscuit, 102… cylinder, 103… piston rod, 104… rod, 105… moving device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29C 45/40 7639-4F B29C 45/40

Claims (1)

(57) [Claims] At least a portion of the melt passage between the injection sleeve insertion hole of the lower mold and the mold cavity, which is closer to the mold cavity, is formed in a small-diameter portion smaller than the inner hole diameter of the injection sleeve. A pin provided to be able to be inserted into and removed from the small diameter part of the passage is supported on the upper mold side so as to be able to move up and down, and can be inserted between the opened upper mold and lower mold. A vertical injection device comprising a biscuit extruding device which is brought into contact with a lower end surface portion of the lower die and a tip end portion of a piston rod provided on a lower end side is provided so as to be insertable into the small diameter portion of the lower mold.