JPH0251701B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vertical mold clamping or vertical injection mold in which molten metal or molten resin is injected into the cavity of a vertically clamped mold from directly below the cavity. This invention relates to an injection molding device.

[Conventional technology]

Injection molding equipment such as die casting machines or injection molding machines for plastics is classified into vertical clamping molds and horizontal clamping molds according to the mold clamping direction, and into vertical injection molds and horizontal injection molds according to the injection direction. be done.

FIG. 5 is a longitudinal cross-sectional view of the main parts of a conventional vertical mold clamping and vertical injection die casting machine. 1
and a movable platen 2 that moves up and down along tie rods (not shown) installed at its four corners, and a fixed mold 3 and a movable mold 4 are fixed to both platens 1 and 2, respectively. has been done. Furthermore, a pair of cores 5 and 6 are interposed between the upper and lower molds 4 and 3 and are supported by the movable mold 4 side, and are moved forward and backward in the horizontal direction indicated by the symbol A by a drive device (not shown). It is configured. The molds 3 and 4 and the cores 5 and 6 in this example are for molding aluminum foil for vehicles.
There is a cavity 7 which is a space having the same shape as the aluminum foil between the convex part and the half-ring-shaped cores 5 and 6.
is formed. On the other hand, below the machine base to which the fixed platen 1 is fixed, an injection cylinder (not shown) is arranged so as to be able to stand up and tilt freely.
9 is a plunger that is moved up and down by this injection cylinder, and 9 is a block that is moved up and down by another cylinder on the injection cylinder side. An injection sleeve 10 into which a plunger 8 is fitted is fixed concentrically to the upper end of this block 9, and when the block 9 is raised, the injection sleeve 10 is moved to the sleeve of the stationary mold 3 as shown in the figure. It is fitted into the hole 3a.
Furthermore, the injection sleeve 10 and the block 9 are engaged in the notch 1a of the fixed platen 1, and when the block 9 is lowered, the injection sleeve 10 is pulled out from the sleeve hole 3a, and the entire injection cylinder is removed by arrow B in the figure.
It is configured to be tilted in the direction shown by , inject the molten metal 11 into the injection sleeve 10, and then stand up.

With this configuration, as shown in the figure, after the mold is clamped, the injection cylinder is tilted with the block 9 and the injection sleeve 10 being lowered, and the molten metal 11 is injected into the injection sleeve 10.
The injection cylinder is erected, the block 9 is raised, and the injection sleeve 10 is fitted into the sleeve hole 3a. When pressure oil is fed into the injection cylinder to raise the plunger 8, the plunger tip 8a, which is the head of the plunger 8, pushes up the molten metal 11 and injects it into the cavity 7. plunger tip 8
When a rises to the position indicated by the chain line 13 and stops, the filling of the molten metal 11 into the cavity 7 is completed.
After waiting for the molten metal 11 to solidify, the movable platen 2 is raised to open the mold, the cores 5 and 6 are moved outward, and the solidified product is ejected from the cavity 7. In this case, the broken line 12 in the figure is the lower end of the product, and this product includes a solidified molten metal, a so-called biscuit, at a location indicated by the reference numeral 14 between the broken line 12 and the chain line 13, which is the upper limit of the plunger tip 8a. do. This biscuit is cut in a separate process after the product is taken out.

[Problem that the invention seeks to solve]

However, in such conventional vertical mold clamping and vertical injection die casting machines, the diameter of the molten metal passage between the cavity 7 and the injection sleeve 10 is set to be smaller than the inner diameter of the injection sleeve 10 in order to remove the product after opening the mold. Since it cannot be made smaller, the biscuit becomes larger and requires more molten metal, which is not only uneconomical, but also, for example, when the surface of aluminum foil, which is indicated by the broken line 12 in the figure, becomes a decorative surface. Since this is the cut surface of the biscuit, there is a problem that the surface becomes rough or that a design cannot be freely applied to this portion using a mold. Furthermore, during casting, the shell, which is the solidified phase of the molten metal, is often pushed up by the plunger tip 8a and enters the cavity 7, which remains inside the product and deteriorates the quality of the product. Something happened. Therefore, conventionally,
In order to block the intrusion of the shell 15, attempts have been made to provide a wire mesh called punching metal at the location indicated by the broken line 12, or to fit a ring into the upper end of the inner hole of the injection sleeve 10, but these methods are troublesome to handle. Therefore, there was a problem that the amount of consumables consumed increased.

[Means for solving problems]

In order to solve these problems, the present invention provides a vertical mold clamping, vertical injection type injection molding device with a cross-sectional area smaller than the inner hole of the injection sleeve in the melt passage between the injection sleeve and the mold cavity. A shear plate for molten solidified material, which had a small hole and was divided into parts with the center of the hole as a boundary, was provided so as to be movable in the horizontal direction.

[Effect]

When the hole in the shear plate is located at the center of the melt passage and the melt is injected into the cavity, the shell generated in the injection sleeve is blocked by the hole in the shear plate and remains in the injection sleeve. After the molten material filled in the cavity solidifies, when both divided shear plates are moved in the same direction, the solidified material in the molten material passage is sheared within the holes of the shear plates, and the mold is opened. The product is held on the side of the movable mold, leaving the biscuit below the shear plate, and ejection completes the injection cycle.

〔Example〕

1 to 3 show an example in which the injection molding apparatus according to the present invention is applied to a vertical mold clamping, vertical injection type die casting machine.
The figure is a sectional view CC of FIG. 1, and FIGS. 3 a to 3 f are longitudinal sectional views of main parts shown for explaining the operation. In the figure, the vertical mold clamping and vertical injection die casting machine includes a fixed platen 21 fixed on a machine base (not shown) and a movable platen 22 that moves up and down along tie rods (not shown) installed at its four corners. Both platens 21 and 22 are equipped with
A rectangular fixed mold 23 and a movable mold 24 are each fixed. Then, a mold clamping cylinder (not shown) above the movable platen 22 closes the movable platen 2.
By raising and lowering the movable mold 24, the movable mold 24 is clamped to the fixed mold 23 and opened. Further, between the upper and lower molds 24 and 23, a pair of cores 25 and 26 having semi-circular inner circumferential surfaces are installed in the movable mold 2.
It is supported and interposed on the 4 side, and is configured to move forward and backward in the horizontal direction indicated by reference numeral D in the figure by a drive device (not shown). And mold 2 of the example
3 and 24 and cores 25 and 26 are for casting aluminum foil for vehicles, and the mold 2
A cavity 27, which is a space having the same shape as the aluminum foil, is formed between the protrusions 3 and 24 and the half-ring-shaped cores 25 and 26. On the other hand, below the machine base to which the fixed platen 21 is fixed,
An injection cylinder (not shown) is arranged so as to be able to stand up and tilt freely, 28 is a plunger that moves up and down with this injection cylinder, and 29 is a block that is moved up and down with another cylinder on the injection cylinder side. An injection sleeve 30 into which a plunger 28 is fitted is concentrically fixed to the upper end of this block 29, and when the block 29 is raised, the injection sleeve 30 is moved to the sleeve of the fixed mold 23 as shown in the figure. It is fitted into the hole 23a. Furthermore, the injection sleeve 30 and the block 29 are connected to the fixed platen 21.
It is engaged in the notch 21a of the block 29.
By lowering the injection sleeve 30 into the sleeve hole 23
a and tilt the entire injection cylinder in the direction shown by arrow E in the figure to release the molten metal 3 in the injection sleeve 30.
1 is injected and then erected. The plunger 28 has a plunger tip 28a as a head that is fitted into the inner hole of the injection sleeve 30.
The plunger 2 is equipped with an injection cylinder.
8 rises and pushes the molten metal 31 with the plunger tip 28a and injects it into the cavity 27. Reference numeral 32 denotes an auxiliary cylinder consisting of a cylinder 32a provided on the rod 28b of the plunger 28 and a piston rod 32b that moves forward and backward by pressure oil fed into the cylinder 32a. It is configured to project from the plunger tip 28a to perform feeding.

Such a molten metal casting apparatus is provided with a device for reducing the diameter of the molten metal passage and shearing the solidified molten metal. That is, the fixed mold 23 has an upper plate 23 formed in a rectangular shape that is stacked one on top of the other and joined with bolts.
b and a lower plate 23c, and the lower plate 23c
As shown in FIG. 2, there is a central guide hole 33 formed in a substantially square concave shape, and sliding grooves 34 and 35 on both sides formed in a concave shape with a smaller width.
are provided continuously, and these guide holes 3
3 and the sliding grooves 34, 35 have cylindrical shapes with upward openings closed by the upper plate 23b. and,
A shear plate 36 for solidified molten metal is movably fitted into the cylindrical guide hole 33 and the sliding grooves 34, 35. This shearing plate 36 has a sleeve hole 37 into which the injection sleeve 30 is fitted, a molten metal hole 38 having the same diameter as the inner hole of the injection sleeve 30, and a constricted hole 39 having a considerably smaller diameter than the inner hole of the injection sleeve 30. They are formed concentrically in this order from the side, and the shear plate 36 connects these holes 37, 38, 3.
It is divided into a shearing plate (right) 40 and a shearing plate (left) 41 with the center of 9 as a boundary. These shearing plates (right) 40 and shearing plates (left) 41 each have a guide portion 40 that is slidably fitted into the guide hole 33.
a, 41a, and sliding portions 40b, 41b that slidably fit into the sliding grooves 34, 35 are formed into a T-shape, and the fitting tolerance of the guide portions 40a, 40b is 0.5 mm on one side. Furthermore, the fitting tolerance of the sliding parts 40b and 41b is set to about 0.1 mm or less on both sides. The shearing plates 40 and 41 configured in this manner are fixed to piston rods 42a and 43a of cylinders 42 and 43 respectively mounted on the lower plate 23c of the fixed mold 23, and are driven by the respective cylinders 42 and 43. is configured to be moved. In this embodiment, the stroke of the right cylinder 42 is approximately 15 degrees to the left from the position shown in the figure.
mm, and the stroke of the left cylinder 43 is set to approximately 30 mm to the left from the position in the figure. When injecting the molten metal into the cavity 27, pressure is applied to the head end side of the left cylinder 43, pushing the shear plates 40 and 41 to the right in the figure, and the shoulder 40c of the right shear plate 40 is pressed against the fixed plate. The shear plates 40 and 41 are pressed against the shoulder portion 23d of the lower plate 23c of the mold 23, and movement of the shear plates 40 and 41 to the right in the figure is restricted. Of course, this movement to the right can also be restricted by the right cylinder 42, but
If the shoulder portions 23d and 40c are used in this way, the position setting adjustment of the shear plates 40 and 41 during injection can be performed reliably and easily. With this structure, when the molten metal 31 filled into the cavity 27 is solidified, pressure is applied to the head end side of the cylinder 42, or pressure is applied to the head end side of the cylinder 42 and the rod end side of the cylinder 43. At the same time, pressure is applied to the shear plate (right) 40 and shear plate (left) 41, which move approximately 15 mm to the left in the figure, shearing the solidified molten material. After this, pressure is applied to the rod end side of the cylinder 42 and the rod end side of the cylinder 43, and the shear plate (right) 40 and the shear plate (left) 41 are both moved approximately 15 mm in a direction away from each other, causing shearing. The biscuits are separated from the shear plates 40 and 41 to ensure that they fall. Further, on both the front and rear sides of the fixed mold 23, a pair of cylinders 44 and 45 are provided as regulating members for regulating the movement of the shear plates 40 and 41 in a direction perpendicular to the movement direction.
a, 45a are fitted into rod holes provided in the lower plate 23c of the fixed mold 23, and by applying pressure to the head end side, the tips of the piston rods 43a, 44a are moved to the center of the shear plates 40, 41. It is configured to be pressed against the end surface of the part. When the shearing plates 40, 41 move, the piston rods 44a, 45a move back and the shearing plates 40, 41 move backward.
Move away from 0,41. Note that a runner hole 46 is located between the cavity 27 and the constriction hole 39 in the upper plate 23.
It is perforated in b.

The operation of the die casting machine configured as described above will be explained based on FIGS. 3a to 3f. In FIG. 3a, the injection sleeve 30 has been lowered together with the block 29, and the plunger 28 has been lowered within the injection sleeve 30. Further, the injection sleeve 30 is filled with a predetermined amount of molten metal 31 injected while the injection sleeve 30 is tilted. The piston rod 42a of the cylinder 42 shown in FIG. 2 is retracted, and the piston rod 43a of the cylinder 43 is
is moving forward, and the shoulder 40c of the shear plate 40 is pressed against the shoulder 23d of the lower plate 23c of the fixed mold 23. Also, the piston rods 44a, 45a of the cylinders 44, 45 are moving forward, and the shear plates 40, 45a are moving forward.
1 is pressed. In this state, the block 29 was raised by a cylinder (not shown), and the injection sleeve 30 was inserted into the sleeve hole 23a of the fixed mold 23 and the sleeve hole 37 of the shear plates 40, 41, as shown in FIG. 3b. Afterwards, when the plunger 28 is raised by the injection cylinder, the plunger tip 28a pushes up the molten metal 31 and injects it into the cavity 27. At the end of injection, the piston rod 32b of the auxiliary cylinder 32 rises and protrudes from the plunger tip 28a to perform feeding. The shell generated within the injection sleeve 30 during injection is transferred to the shear plate 4
It is restricted from rising at the peripheral edge of the constricted hole 39 of 0.41 and is compressed into a bellows shape, so that it does not enter into the cavity 27. When filling the cavity 27 with the molten metal 31, the high heat of the molten metal 31 causes the shear plate 4 to
0 and 41 try to thermally expand, and a large pressure of 1000 Kg/cm ² acts on the inside of the shear plates 40 and 41 due to the injection of the molten metal 31, causing the shear plates 40 and 41 to expand thermally.
41 tries to bulge outward, but since the piston rods 44a, 45a of the cylinders 44, 45 are pressed against the side surfaces of the shearing plates 40, 41 by cylinder pressure, the shearing is prevented by the injection of the riser. Board 4
0 and 41 are swollen and their guide portions 40a and 41a
etc. will not be pressed against the guide hole 33 etc. and seize it, or its sliding will be prevented. In addition, the shear plates 40 and 41 will not be deformed and the constricted hole 39 will open, and the movement of the shear plates 40 and 41 will become heavy during the subsequent shearing operation of the solidified molten metal, and burrs and solid matter will not be eaten. No congestion occurs. In this case, pressure is acting on the head end side of the piston rod 43a of the opening/closing cylinder 43 of the shearing plate (left) 41.
is pushed to the right, shoulder 4 of shear plate (right) 40
The shear plate 4
0 and 41 do not move in the opening/closing direction either. Of course, in this case, pressure may be applied to the head end side of the opening/closing cylinder 42 of the shear plate (right) 40 to restrict its movement to the right.

After the molten metal 31 in the cavity 27 solidifies and the injection sleeve 30 is lowered, the front and rear cylinders 4
The piston rods 44a and 45a of 4 and 45 are moved back, and the shear plates 40 and 41 are released from the pressure. And the piston rod 42a of the right cylinder 42
For example, when the piston rod 43a of the cylinder 43 is moved forward by about 15 mm and at the same time the piston rod 43a of the cylinder 43 is moved back by the same amount, the solidified molten metal is sheared from the boundary between the runner hole 46 and the constriction hole 39, as shown in FIG. 3c. . In this case, the shear plates 40, 41 are not pressed by the piston rods 44a, 45a, and therefore move smoothly.

Next, prior to mold opening, as shown in FIG. 3d, the piston rod 42a of the right cylinder 42 is moved back, for example, by about 15 mm to its original position before being advanced, and at the same time, the piston rod 43 of the left cylinder 43 is moved back.
For example, move a further by 15 mm than the position shown in Figure 3 c.
When the shearing plates 40, 41 on both sides are moved back to a certain extent, they separate from the sheared compound, so-called biscuit 47, attached to them, and the biscuit 47 falls. At this time, as shown by the chain line in FIG. 3d, a convex portion is provided at the tip to fit into the concave portion on the lower surface of the biscuit 47 (the hole formed when the tip of the piston rod 32b of the auxiliary cylinder 32 operates during the feeder operation). The formed biscuit support rod 47a is attached to the biscuit 47.
If the shear plates 40 and 41 are opened by pressing against them from below to support the biscuit 47 and prevent it from moving left and right, the biscuit 47 will escape even when the force of the biscuit 47 and the shear plates 40 and 41 is strong. This allows the biscuit to fall reliably downward. FIG. 3e shows the biscuit 47 falling, and after the biscuit 47 has fallen, the piston rod 43a of the cylinder 43 is advanced, for example, by about 30 mm, as shown, to return it to its original position at the time of injection.

Then, as shown in FIG. 3f, the movable platen 22
When the mold is opened by raising the mold, the product in the cavity 27 is held on the movable mold 24 side and rises, so the cores 2 on both sides rise together with the movable mold 24.
After opening 5 and 26 outward and separating them from the product, when a protrusion pin of a protrusion device (not shown) is lowered, the product 48 falls. Therefore, the product 48 is received by an arm of a product unloading device (not shown) and transported outside the machine.
discharge. One casting cycle is completed by clamping the mold after taking out the product. The removed product 48 comes with a runner 49, so either cut it off with a cutting tool on a lathe or provide a thin wall at the base of the runner 49 and punch it with a punch or the like from the direction shown by arrow F in Figure 3f. Alternatively, the runner 49 may be folded.

The above example shows an example in which the present invention is applied to a normal vertical mold clamping and vertical injection die casting machine, but in reality, the injection device, product ejection device, mold spray device, etc. are installed in separate stations. It is desirable to apply this method to rotary die-casting machines. That is, both molds 23 and 24 are held openable and closable at positions that divide the rotary table into three equal parts in the circumferential direction, and an injection station, a product ejection station, and a mold press station are arranged on the orbit of the rotary table. The mold stops intermittently at each station, and the injection station injects the molten metal, the product take-out station shears the biscuit 47, opens the mold, extrudes and takes out the product, and the mold spray station performs the following operations: Have them do their own spraying, etc.

FIG. 4 is a longitudinal cross-sectional view of the main parts of a die-casting machine showing another embodiment of the present invention corresponding to FIG. 1, and members having the same structure as those shown in FIGS. , and the explanation thereof will be omitted. In this example, as is clear from a comparison with FIG.
The convex portion 24a of the movable mold 24 is raised, and the fixed mold 2
The convex portion 23d of No. 3 is lowered. By doing this, the aluminum foil as a cast product is cast upside down, and the decorative surface side on which the design is applied becomes the runner 46 side. However, since the decorative surface does not have the biscuit 14 with a large diameter as shown in FIG. 5, but only a thin runner, a degree of freedom in design can be obtained.

In addition, although each of the above embodiments shows an example in which the present invention is applied to a die-casting machine for casting aluminum foil, the product is not limited to aluminum foil, and any product may be used. Further, the present invention can be applied not only to die casting machines but also to injection molding machines for plastics.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in a vertical mold clamping and vertical injection molding apparatus,
In the molten material passage between the injection sleeve and the mold cavity, a shear plate for the molten solidified material is provided which has a hole having a smaller cross-sectional area than the inner hole of the injection sleeve and is divided into sections at the center of this hole. By making it movable in the horizontal direction and making the molten material passage smaller than before, the amount of excess solidified material attached to the product is reduced, reducing the amount of molten metal consumed, making it economical. Since it is small, even if this part becomes a decorative surface, the aesthetic appearance is not impaired, and it is possible to add a design using a mold, which provides a degree of freedom in design. Furthermore, by reducing the size of the molten material passage, the molten solidified material solidified within the injection sleeve during injection is blocked by the reduced passage and does not enter the cavity, resulting in a significant improvement in the quality of the product.

[Brief explanation of drawings]

1 to 4 show an embodiment of the injection molding apparatus according to the present invention, FIG. 1 is a vertical sectional view of the main parts of a vertical mold clamping and vertical injection die casting machine to which this is applied, and FIG. Figure 1 is a cc sectional view, Figures 3 a to f are longitudinal sectional views of main parts shown to explain the operation, and Figure 4
The figure is a vertical cross-sectional view of the main part showing another embodiment of the present invention corresponding to FIG. 1, and FIG. 5 is a vertical sectional view of a conventional vertical mold clamp.
FIG. 2 is a vertical cross-sectional view of the main parts of the vertical injection die-casting machine. 23...Fixed mold, 23b...Top plate, 23c...
... Lower plate, 24 ... Movable mold, 27 ... Cavity, 28 ... Plunger, 30 ... Injection sleeve, 31 ... Molten metal, 33 ... Guide hole, 34, 35
...Sliding groove, 36... Shear plate, 39... Neck hole, 40... Shear plate (right), 40a, 41a...
Guide part, 40b, 41b...Sliding part, 41...Shear plate (left), 42, 43...Cylinder, 42a,
43a... Piston rod.

Claims (1)

[Claims] 1. In an injection molding apparatus that injects a melt in a vertical injection sleeve into a cavity of a vertically clamped mold from directly below the mold, the melt is injected into the melt passage between the injection sleeve and the cavity. A molten solidified material shearing plate having a hole having a smaller cross-sectional area than the inner hole of the injection sleeve and divided into parts with the center of the hole as a boundary is provided so as to be movable in the horizontal direction, and the small hole is inserted into the shearing plate. An injection molding apparatus characterized in that the pore size is such that the molten solidified material in the passage can be sheared by movement.