JPH0156861B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a molten metal casting device for injecting molten metal into a cavity of a mold clamped in a die casting machine.

[Conventional technology]

Traditionally, many die casting machines had the mold clamping direction and the injection direction in the same direction, but in recent years, horizontal mold clamping and vertical casting machines have been introduced, which inject the molten metal from below into a horizontally clamped mold. A mold die casting machine has been developed.

This type of die casting machine is characterized by the fact that the length of the molten metal in the casting sleeve before injection is short and the temperature drop of the molten metal is small. It has many advantages, such as the small amount of cavities caused by gas in the casting sleeve due to the small amount of contact, and the fact that the injection plunger faces the inside of the cavity when filling is completed, which allows pressure to be transmitted effectively. However, there was a problem in that the molten metal solidified on the side wall surface of the casting sleeve entered the cavity due to the temperature drop during injection, degrading the quality of the product.

Therefore, the present applicant proposed a die-casting method and apparatus disclosed in Japanese Patent Publication No. 58-55859 to prevent the intrusion of the coagulated material. FIG. 7 is a cross-sectional view of the molten metal casting part, and to explain this based on the same figure, there is a fixed mold 2 and a movable mold 3 of the horizontal clamping mold joined at the dividing surface 1. A split cylindrical fixing sleeve 4 is fitted, and a casting sleeve 5 that has been raised by the lower cylinder is joined to the lower end of the fixing sleeve 4. Casting sleeve 5
A plunger 6 that moves forward and backward in the vertical direction by an injection cylinder during vertical casting is fitted inside. A small diameter constriction 9 is formed between the cavity 7 of the molds 2 and 3 and the large diameter vertical hole 8 which is the inner hole of the fixed sleeve 4.

With this configuration, when the plunger 6 is advanced after pouring metal into the casting sleeve 5 which is in the lowered position and raising it to the position shown in the figure, the molten metal inside the casting sleeve 5 is moved forward. It is cast into the cavity 7 through the vertical hole 8 and the constriction 9. A shell 10 is formed as a thin cylindrical solidified material along the inner peripheral surface of the vertical hole 8 during casting.
By compressing the shell 10 into a bellows-like shape between the plunger 6 and the step plane in front of the constriction 9, the shell 10 remains in the vertical hole 8 and prevents it from entering the cavity 7. can do. After the casting is completed, the product solidified and taken out from the cavity 7 is attached with a so-called biscuit 11, which is a solid substance left above the plunger 6, via the solid substance in the constriction part 9. This can be easily removed by breaking off the thin solid material corresponding to No. 9.

[Problem that the invention seeks to solve]

However, in such a conventional molten metal casting apparatus, when the casting sleeve 5 and the plunger 6 are lowered after completion of casting, the casting sleeve 5 and the biscuit 11 are in close contact with each other on their circumferential surfaces. Due to the coefficient of friction, the biscuit 11 may stick to the casting sleeve 5 and fall down, and the solid material may be cut off from the thin part corresponding to the constriction 9, leaving the biscuit 11 on the casting sleeve 5 side when the product is removed. Ta. Particularly, in a partial shot, which aims to obtain good casting conditions by observing the flow state of molten metal in the cavity during pouring, when pouring is attempted to stop mid-way during pouring, The plunger 6 is lowered at an appropriate position where the molten metal has been poured halfway, but in this case, the biscuit 11 is easily broken from the constriction 9 when the plunger 6 is lowered. In particular, when the plunger 6 is stopped in the middle of the casting sleeve 5, the length of the portion of the biscuit 11 remaining inside the casting sleeve 5 is always longer than the length of the fixed sleeve 5. The biscuit 11 was attached to the casting sleeve 5 and descended for a long time.

In this way, since the biscuit 11 remains on the casting sleeve 5 side, not only the next pouring cannot be performed, but also the injection cylinder is opened with the biscuit 11 cut at the constriction 9 still protruding from the casting sleeve 5. When tilted, the tip of the casting sleeve 5 crosses the lower end notch of the fixed platen 25 in FIG. 2 showing the present invention, and is tilted to the molten metal supply position. The tip of the biscuit 11 collides with the cutout edge of the lower end of the stationary platen 25 and cannot be tilted. Therefore, the projecting portion of the biscuit 11 from the casting sleeve 5 is cut off using gas, and then the casting sleeve 5 is tilted to the molten metal supply position and the plunger 6 is raised to remove the remaining inside of the casting sleeve 5. The present biscuit 11 had to be extruded and removed, which was inconvenient in that it significantly reduced work efficiency.
Furthermore, if the biscuit 11 protrudes from the casting sleeve 5, even if the plunger 6 is raised with the casting sleeve 5 lowered to push out the biscuit 11 from the casting sleeve 11, the amount by which the casting sleeve 5 is lowered will be Since the tip of the biscuit 11 is small, the tip of the biscuit 11 hits the lower end plane of the constriction part 9 of the fixed mold 30, so the biscuit 11 cannot be removed from the casting sleeve 5 unless it is cut with gas.

[Means for solving problems]

In order to solve these problems, in the present invention, the molten metal passage of a horizontal mold clamping, vertical casting type molten metal pouring device is formed by a constriction and a large diameter vertical hole continuous below the constriction. A concave groove was provided on the circumferential surface of the part.

[Effect]

By joining the casting sleeve to the stationary sleeve and moving the plunger forward, the molten metal in the casting sleeve is poured into the mold cavity, and a part of the molten metal enters the groove and the constriction between the constriction and the plunger. The shell formed in between is compressed into a bellows shape and remains within the vertical hole. When the plunger is lowered after the molten metal has solidified, the biscuit formed in the vertical hole engages with the groove and remains on the fixed sleeve side without being carried along by the plunger, and when the mold is opened to take out the product. Biscuits are also taken out along with the product.

〔Example〕

1 to 3 show an embodiment of the molten metal casting apparatus according to the present invention, FIG. 1 is a cross-sectional view of the molten metal casting part, and FIG. 2 is a horizontal mold clamping type and a vertical mold type according to the present invention. A longitudinal cross-sectional view of the die-casting machine, Figure 3 is the same as Figure 2.
It is an AA sectional view. In the figure, a die casting machine 21 is equipped with a horizontal mold clamping unit 22 and a vertical casting unit 23, and the horizontal mold clamping unit 22 includes:
A machine base 24 fixed to the floor surface, a fixed platen 25 fixed to one end of the machine base 24, and an end platen (not shown) fixed to the other end of the machine base 24 so as to be movably adjustable are provided. . A column 26 connects the four corners of the fixed platen 25 and the end platen and is fixed with nuts 27. A movable platen 28 is supported on this column 26 so as to be able to move forward and backward with respect to the fixed platen 25. This movable board 2
8 and a mold clamping cylinder (not shown) on the end platen side are connected by a toggle mechanism 29. 30 is a fixed mold mounted on the fixed platen 25, whose movement in the vertical direction is regulated by a key 31, and which is positioned perpendicularly to the plane of the paper by a key 31a provided vertically in the center of the fixed platen 25;
Reference numeral 2 denotes a movable mold that is mounted on a movable platen 28 and whose movement in the vertical direction is regulated by a key 33, and both molds 30 and 32 can be opened and closed horizontally with a dividing surface 34 as a boundary. It is joined. Here, the reason why the vertical key 31a is provided between the fixed platen 25 and the fixed mold 30 on the center line of the machine is because
Easily align the horizontal center of the fixed mold 30 with the casting sleeve 52 of the vertical casting unit 23 provided below the dividing surface 34 between the fixed mold 30 and the movable mold 32 on the center line of the machine. This is because I did so.

Both molds 30 and 32 have a cavity 35 having the same shape as the cast product, and a constriction 36 continuing below the cavity 35.
and a large-diameter vertical hole 37 that continues below and opens downward are provided, separated by the dividing surface 34. At the boundary between the constriction 36 and the vertical hole 37, there is a shaft. A shell contact surface 38 is formed which is a plane orthogonal to the core. In addition, the vertical hole 3
A fixed sleeve 39 in the form of a half is fitted into the housing 7 . 40 is a product extrusion device that extrudes the cast product from inside the cavity 35.

A frame 41 of the vertical casting unit 23 is erected in a pit 42 provided below the mold clamp and supports the end of the machine base 24. between 26 and 4
A cast frame 44 connected by support rods 43 is provided close to the bottom surface of the pit 42. 4
Reference numeral 5 denotes an injection cylinder rotatably supported on a cast frame 44, and a plunger 47 having a plunger tip 47a on the head thereof is connected to the piston rod 46 via a coupling 48. The plunger 47 is configured to be raised and lowered by hydraulic pressure 45. 49
is a block supported by fitting a pair of rams 50 implanted in the upper end surface of the injection cylinder 45 into the ram holes, and the hole at the lower end engages with the piston rod 46. Block 49
The pressure oil introduced into the cylinder 51 provided in the block 49 and the lowering of the piston rod 46
is configured to move up and down.

A fixing sleeve 39 is attached to the upper end surface of the block 49.
A cast sleeve 5 formed into a cylindrical shape with the same center and diameter as
2 is fixed, and when the block 49 is raised by the hydraulic pressure of the cylinder 51, the casting sleeve 52
and fixed sleeve 39 are concentrically pressed together, and as block 49 descends, both sleeves 5
2 and 39 are configured to be separated from each other.

Reference numeral 53 is a tilting cylinder pivotally supported on the frame 41 side, and the working end of its piston rod is pivotally connected to the injection cylinder 45, and when the block 49 is lowered, both sleeves 39,
By operating the tilting cylinder 53 with the parts 52 separated, the entire vertical casting unit 23 is
It is configured to stand up and tilt between the casting position shown in the figure and the inclined pouring position. Reference numeral 54 designates an adjustable stopper that abuts the injection cylinder 45 to limit its rotation toward the casting position.

At the upper end of the inner circumferential surface of the fixed sleeve 39 fitted in the vertical hole 37, there is a groove 39a having a rectangular cross section that allows the molten metal to enter when the sleeve is filled with the molten metal. It is provided with an opening, so that even if the plunger 47 descends after the molten metal has solidified, the solid biscuit remains in the groove 39a.
The plunger 47 is configured so that it does not descend together with the plunger 47 once it is caught on the plunger 47.

The casting operation of the die casting machine configured as above will be explained. When the fixed mold 30 and the movable mold 32 are mounted on the fixed plate 25 and the movable plate 28, respectively, and the piston rod of the mold clamping cylinder (not shown) is advanced, the movable plate 28 is in the mold opening position.
is moved to the illustrated mold clamping position via the toggle mechanism 29, and mold clamping is performed. During this mold clamping, the piston rod 46 of the injection cylinder 45 has been lowered to the position shown in the figure, and the block 49 has been lowered from the position shown in the figure, so that both the sleeves 39, 5
2 are apart, so when the piston rod of the tilting cylinder 53 is advanced, the vertical casting unit 23
The entire body tilts, and the casting sleeve 52 comes out from below the fixed platen 25 (to the right in FIG. 2).
After injecting molten metal into the casting sleeve 52 by squeezing or the like, the tilting cylinder 53 is operated again to vertically raise the vertical casting unit 23, and pressure oil is fed into the cylinder 51 of the block 49. , the block 49 is raised and the casting sleeve 52 is concentrically pressed against the lower surface of the fixed sleeve 39.

After this, pressure oil is introduced into the injection cylinder 45 to raise the piston rod 46, and the plunger 47 is raised via the coupling ring 48 to inject the mold 3.
The mold 30,
The molten metal in the casting sleeve 52 is poured into the cavity 35 of the casting sleeve 52. In this case, the molten metal is transferred to the fixed sleeve 3
9, it also penetrates into the groove 39a. Also,
Prior to pouring the molten metal, a portion of the molten metal along the inner wall surface of the casting sleeve 52 begins to solidify, and a thin cylindrical solidified substance, a so-called shell, is generated, and as the plunger 47 rises, this shell is released from the plunger tip. 47a and the shell contact surface 38, and remains in the casting sleeve 52 even after casting.

When the casting is completed and the molten metal in the cavity 35 is solidified and cooled to become a product, the pressure oil in the cylinder 51 is removed and the block 49 is lowered to separate the casting sleeve 52 from the fixed sleeve 39. The pressure oil in the injection cylinder 45 is removed and the plunger 47 is lowered. Then, by retracting the piston rod of the mold clamping cylinder,
One cycle is completed by moving the movable platen 28 away from the fixed platen 25 to open the mold, and extruding the cast product by the product extrusion device 40.

When the plunger 47 descends before taking out the product, the upper end surface of the plunger tip 47a and the biscuit 55 formed by the solidification of the molten metal above it come into close contact, and the biscuit 55 descends with the plunger 47. However, the molten metal enters the groove 39d and the biscuit 55
Since the biscuit 55 is formed into a stepped shape that enters the groove 39a, the biscuit 55 remains on the product side and only the plunger 47 descends. As a result, cavity 35
Since the product extruded from the product includes a thin joint corresponding to the constricted portion 26 and a biscuit 55, the biscuit 55 can be easily separated from the product by breaking the thin joint with a hammer or the like.

FIG. 4 is a cross-sectional view of a molten metal casting part showing another embodiment of the present invention corresponding to FIG. It is located a little below the top edge and has a constant width around the entire circumference. By doing this, the molten metal enters the groove 39b and the biscuit remains on the product side, as in the previous embodiment.

Note that the concave groove may be provided only on the fixed mold 30 side of the fixed sleeve 39 split in half, or the groove may be provided only on the fixed mold 30 side of the half-split fixed sleeve
As shown in the cross-sectional view in the figure, the groove 39c may be provided only in a part of the entire circumference of the fixed sleeve 39.

FIGS. 6a, b, c, and d each show an embodiment for improving mold release of the product, and FIG.
9 is provided with an inclined surface 39d extending in the tangential direction of the inner hole at the joint part of the fixed mold 30 side, and this inclined surface 39d may be provided over the entire length of the fixed sleeve 39 or only on a part It may be provided. 6th
In the one shown in FIG. b, the interface 39e between the constriction part 36 and the vertical hole part is formed into a tapered shape.
In FIG. 6c, this tapered boundary surface 39e is provided only on the fixed mold 30 side. Furthermore, in FIG. 6d, the upper end surface of the plunger tip 47a is formed into an inclined surface 47b such that the fixed mold 30 side is higher. With the above configuration, all of the products shown in FIGS. 6a, b, c, and d can be easily separated from the mold when the mold is opened and the product is taken out.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in a molten metal casting apparatus, the molten metal passage is formed by a constriction and a large diameter vertical hole continuous below the constriction, and a groove is provided around the vertical hole. This not only improves the quality of the product by preventing the solidified molten metal from entering the cavity, but also prevents the molten metal from entering the concave grooves during casting, which is equivalent to the concave grooves in biscuits due to the solidification of the molten metal. The biscuits do not follow the descent of the plunger and are removed as they are attached to the product, allowing for smooth pouring and improved work efficiency as there is no need to cut the remaining biscuits. do.

[Brief explanation of drawings]

1 to 6 show an embodiment of the molten metal casting apparatus according to the present invention, FIG. 1 is a longitudinal cross-sectional view of the molten metal casting part, and FIG. A vertical cross-sectional view of the mold die casting machine, Figure 3 is the same as Figure 2.
AA sectional view, FIG. 4 is a vertical cross-sectional view of a molten metal casting part showing another embodiment of the present invention, and FIG. 5 is a cross-sectional view of a molten metal casting part showing another embodiment of the present invention. Figures 6a, b, c, and d each show other embodiments of the present invention, with Figure 6a being a cross-sectional view of the molten metal casting part, and Figures 6b to 6d being longitudinal cross-sections of the molten metal casting part, respectively. 7 are longitudinal cross-sectional views of a molten metal casting section in a conventional molten metal casting apparatus. 21... Die casting machine, 30... Fixed mold, 32... Movable mold, 34... Divided surface, 35...
... Cavity, 36 ... Constriction, 37 ... Vertical hole, 38 ... Shell contact surface, 39 ... Fixed sleeve, 39a, 39b ... Concave groove, 45 ... Injection cylinder, 47 ... Plunger, 52 ...Cast-in sleeve.

Claims (1)

[Claims] 1. In a horizontal mold clamping, vertical casting type molten metal casting device in which the molten metal in a vertical casting sleeve is poured into the mold cavity from directly below the dividing surface of a mold clamped in the horizontal direction, the said cavity and the casting A molten metal passage between the sleeve and the sleeve is formed by a constriction and a large diameter vertical hole continuous below the constriction, and a concave groove is provided on the circumferential surface of the vertical hole to allow the molten metal to enter. Molten metal casting equipment.