JPH1190607A - Vertical type casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cast a casting product without mixing oxide by confining an oxide film on the surface of a molten metal into a molten metal pool, at the time of supplying the molten metal. SOLUTION: A vertical type casting method is provided with a fixed die 1 at the lower side, a movable die 2 at the upper side, an injecting device at the lower side of the fixed die 1 and further, a molten metal pool 13 having a shape that a bowl having a larger inlet diameter by a little bit than the diameter of a circular gate 12 at the upper part movable die 2 having the same core as the circular gate 12 of the fixed die 1. An oxide film on the surface of a molten metal 22 rising from the circular gate 12 at the time of casting, is confined into the molten metal pool part 13 by proving a gap 14 between the fixed die 1 and the movable die 12 at this molten metal pool part to a position lower by a little bit than a runner so as not to mix the oxide into the product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical casting method for injecting a molten metal into a mold cavity from directly below.

[0002]

2. Description of the Related Art When manufacturing aluminum products by casting, in the case of parts requiring strength, a vertical die casting machine is often used in order to prevent entrapment of gas during casting of molten metal. As for a method of manufacturing an aluminum wheel for automobiles, for example, as described in Japanese Patent Publication No. 3-4297, casting using a gate having a diameter smaller than the sleeve diameter and a pin having a diameter slightly smaller than the gate inner diameter has already been performed. Although used, it was not always sufficient to prevent the inclusion of oxides and the entrapment of gas.

When casting a general part, as shown in FIG. 21, a casting sleeve 3 and a casting gate 1 are used.
Numeral 2 is provided at a location away from the cavity 11 provided between the fixed mold 1 and the movable mold 2, and the inner diameter of the sleeve 3 is directly used as the gate because the biscuit (feeder) as the gate is not related to the product shape. Used and the biscuits can be removed with the product so that small gate diameters are not normally used. In FIG. 21, 4 is a plunger tip, 5 is a plunger, 6 is a fixed platen, 7 is a movable platen, 8 is a tie bar, 9 is a tie bar nut, 10
Is a side gate.

[0004]

The sleeve 3
When casting with the gate 12 having the same diameter as the inner diameter of the injection cylinder, the force of the injection cylinder is sufficiently transmitted and the removal of the biscuit is easy, but when the molten metal is poured into the sleeve 3, an oxide film and a sleeve generated on the surface are formed. The chill layer generated by cooling on the inner surface of No. 3 was mixed into the product together with the casting and caused a defect.

Therefore, it is possible to prevent an oxide film on the surface of the molten metal poured into the sleeve, which causes a product defect, and a chill layer, ie, a solidified layer, generated by cooling on the inner surface of the sleeve from being mixed into the product. It is necessary to prevent entrapment of gas in the section.

[0006]

According to the present invention, in order to solve such a problem, an injection device is provided below a lower fixed mold, an upper movable mold and a fixed mold, and a fixed mold is provided. In the upper movable mold, which is concentric with the circular gate, an inlet diameter is slightly larger than the diameter of the circular gate. By providing the gap of the movable mold at a position slightly lower than the runner, the oxide film floating on the surface of the molten metal that rises from the circular gate during casting rises immediately above, is sealed in the well, and is filled with the circular gate outlet and hot water. An oxide film was not formed from a gap between the bottom entrance of the reservoir and the oxide, so that oxides were prevented from being mixed into the product.

When it is desired to completely prevent the oxide film from flowing out of the gap, as shown in FIG. 2, a portion forming a water reservoir is separated into a movable mold and a water reservoir slidable vertically. I do. In this case, when the tip of the molten metal having the oxide film rises in the circular gate, lower the water reservoir insert so that the gap between the circular gate outlet and the lower end entrance of the molten metal becomes zero, and the tip of the molten metal is When there is no longer any possibility that the oxide film will come out of the gap after entering the basin, the nest is pulled up to feed the molten metal free of the oxide film into the cavity.

As one of the methods, a tub insert is pressed against a lower fixed mold by a spring force or an air cylinder or a hydraulic cylinder, and when the molten metal is filled in the basin, it is pushed up by a reaction force of the filling pressure. A gap is formed, and the molten metal free of the oxide film can be fed into the cavity.

In some cases, for example, when casting aluminum wheels for automobiles, the diameter of the circular gate of the fixed mold must be smaller than the inner diameter of the casting sleeve. In such a case, the gate needs to be cut as shown in FIGS. 3 and 4, and a gate cutting pin is provided. When the basin is fixedly mounted on the movable mold, a cutting pin is slidably attached to the movable mold to seal the oxide film in the basin and to cut the gate.

In order to completely enclose the oxide film in the basin, it is necessary to dispose a basin having a basin slidably in a movable mold and attach a cutting pin to the center of the basin. Thus, as described above, the oxide film is completely sealed in the basin and the gate can be cut.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the apparatus for carrying out the present invention are shown in FIGS. 1 to 4, and the operation sequence thereof is shown in FIGS.

As a representative example, the contents described in claim 2 will be described with reference to FIG. 2 and FIGS. 5 to 11. Reference numeral 1 denotes a fixed die, which is mounted on a horizontal fixed platen 6 at the lower part of the casting machine. Reference numeral 2 denotes a movable mold, which is attached to a movable platen 7 disposed opposite to the upper part of the fixed platen 6 so that the movable mold can be vertically moved toward and away from the fixed mold 1 to perform mold closing and mold opening. It has become.

Reference numeral 3 denotes a casting sleeve, which is attached to the injection cylinder frame via a docking frame (not shown). Reference numeral 4 denotes a plunger tip, and 5 denotes a plunger, which is attached to a rod of an injection cylinder. Both of them are tilted by a tilt cylinder of the injection cylinder as shown by a chain line in FIG. 22 can be supplied with hot water. After the molten metal 22 is supplied into the casting sleeve 3, the casting sleeve 3 is tilted to be vertical and can be docked to the fixed mold 1 as shown by a solid line in FIGS.

A vertical circular gate 12 forming a molten metal passage is provided through the center of the upper portion of the fixed mold 1 where the casting sleeve 3 is docked, and faces the circular gate 12 of the movable mold 2. A round pool 13 having a diameter slightly larger than the diameter of the circular gate 12 and having a concave shape such that a bowl having a predetermined depth is opened is provided at the lower portion. ing.

The basin 13 is attached to the tip of a basin 16 that is slidable up and down in the movable mold 2 in order to reliably capture the oxide film 23. For this reason, at the start of hot water supply, the tip abuts on the outlet surface 12a of the circular gate 12 of the fixed mold 2 to eliminate the gap 14 to prevent the outflow of the hot water, and reliably guide the oxide film 23 in the hot water into the well 13. After the trapping, the gap 14 is pulled up to an appropriate size and the molten metal 22 containing no oxide is removed from the circular gate outlet 1.
5. It is supplied to the cavity 11 through the side gate 10 so that a high quality cast product can be produced.

The nest 16 is operable by a piston 17 of a cylinder 18 for operating a nest mounted on the movable mold 2 or the movable platen 7. When the dimensions of the gap 14 can be fixed depending on the shape of the fixed mold 1 and the movable mold 2 or the properties of the molten metal 22, FIG.
As shown in (1), the basin 13 may be manufactured integrally with the movable mold 2, and in this case, it is not necessary to use the basin insert 16.
However, at this time, the structure is simplified.

When it is necessary to reduce the size of the basin due to the shape of the product or the like, a circular gate 12 having a diameter smaller than the inner diameter of the sleeve 3 is used as shown in FIGS. Most of the oxide film 23 on the surface of the molten metal 22 and most of the chill amount generated in the sleeve 3 are left in the biscuit 25 without passing through the small-diameter circular gate 12. The cutting pin 19 is used to cut the biscuit 25, and this operation is performed by the piston 20 in the cutting pin operation cylinder 21.

Next, the operation will be described.

First, the molten metal 22 poured into the sleeve 3
After the sleeve 3 is docked to the fixed mold 1, the plunger 5 is pushed up to move up the inside of the sleeve 3 and start casting (FIG. 5).

The tip of the hot water enters the well 13 (FIG. 6). Generally, the oxide film 23 is lighter than the melt 22 and floats on the surface of the melt 22 and is connected with a small strength. Next, as shown in FIG. 7, if the gap 14 is formed by slightly raising the hot water nest 16, the molten metal 22 flows out through the gap, but if the gap 14 is set at a position slightly lower than the side gate 10, the molten metal is melted. 22 is an oxide film 23 on the surface of the molten metal 22 in the basin 13 even if it flows out through the circular gate outlet 15.
Does not flow out without lowering to the height of the gap 14 (FIG. 8).

Next, as shown in FIG. 9, when the filling of the molten metal 22 into the cavity 11 is completed, the process waits for cooling, and then proceeds with mold opening (FIG. 10) and product removal (FIG. 11). When the possibility of the oxide film 23 flowing out of the gap 14 is small, the movable mold 2 having the shape in which the water reservoir 16 is fixed in the state of FIG.
It can also be.

Further, the diameter of the circular gate 12 is
In order to cut the biscuit 25, the cutting pin 19 must be used. The sequence in this case is shown in FIGS.

First, the molten metal 22 poured into the sleeve 3
After the sleeve 3 is docked to the fixed mold 1, the plunger 5 is pushed up to move up the inside of the sleeve 3 and start casting (FIG. 12).

The hot water enters the basin 13 (FIG. 13). At this time, the oxide film 23, which is lighter than the melt 22 and floats on the surface of the melt 22 and is connected with a small strength, enters the pool 13. Next, as shown in FIG. 14, the molten metal 22 flows out when the gap 14 is formed by slightly raising the hot water nesting member 16 as shown in FIG. 14, but if the gap 14 is set at a position slightly lower than the side gate 10, the molten metal is melted. 22 is the circular gate exit 15
The oxide film 23 on the surface of the molten metal 22 in the basin 13 does not flow to the outside without lowering to the height of the gap 14 even if it flows out through the reservoir 13 (FIG. 15).

Next, as shown in FIG. 16, when the filling of the molten metal 22 into the cavity 11 is completed, the cutting pin 19 is lowered to push the tip into the molten metal 22 to pressurize the molten metal 22 (FIG. 17). When the cutting pin 19 is subsequently lowered, the tip of the biscuit 25 is cut through the circular gate 12 (FIG. 18). Thereafter, the cutting pin 19 is raised to the original position, and the operations of opening the mold (FIG. 19) and removing the product (FIG. 20) are performed.

[0026]

As is apparent from the above description, according to the present invention, when filling the mold cavity with the molten metal, the oxide film at the tip of the molten metal is caught in the molten metal and flows out to the product side to form a defect. Can be prevented, so that a high quality cast product can be produced. On the other hand, since the oxide film is removed in the mold, an ordinary hot water supply machine can be used for the molten metal, and the use of a normally used wire mesh at the gate entrance is not required, which is a great economical advantage.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a vertical casting apparatus when a basin is formed in a movable mold according to the present invention.

FIG. 2 is a vertical cross-sectional view of a vertical casting apparatus in a case where a basin according to the present invention is installed on a basin and the basin is slidably mounted on a movable mold.

FIG. 3 is a vertical sectional view of a vertical casting device in a case where a circular gate diameter is smaller than a sleeve diameter and a basin is formed in a movable mold.

FIG. 4 is a vertical cross-sectional view of a vertical casting apparatus in a case where a circular gate diameter is made smaller than a sleeve diameter and a water reservoir is slidably mounted on a movable mold.

FIG. 5 is a sequence diagram of the vertical casting apparatus shown in FIG. 2 according to the present invention, showing an operation diagram at the time of starting casting.

FIG. 6 is a diagram showing an operation subsequent to FIG. 5;

FIG. 7 is a diagram showing an operation subsequent to FIG. 6;

FIG. 8 is a diagram showing an operation subsequent to FIG. 7;

FIG. 9 is a diagram showing an operation subsequent to FIG. 8;

FIG. 10 is a diagram showing an operation subsequent to FIG. 9;

FIG. 11 is a diagram showing an operation subsequent to FIG. 10;

12 is a sequence diagram of the vertical casting device shown in FIG. 4 according to the present invention, and is a diagram showing an operation diagram of casting start.

FIG. 13 is an explanatory view showing a continuation of the operation shown in FIG. 12 and showing a state in which a hot end enters a basin.

FIG. 14 is an explanatory view showing a continuation of FIG.

FIG. 15 is an explanatory view showing the operation subsequent to FIG. 14 and showing filling of the molten metal cavity.

FIG. 16 is an explanatory view showing the operation subsequent to FIG. 15 and showing completion of filling.

FIG. 17 is a diagram showing an operation continued from FIG. 16;

FIG. 18 is a view illustrating the operation following the operation in FIG. 17;

FIG. 19 is a view showing the operation following FIG. 18;

FIG. 20 is a diagram illustrating an operation subsequent to that of FIG. 19;

FIG. 21 is a schematic view of a conventional vertical casting device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fixed mold 2 movable mold 3 casting sleeve (sleeve) 4 plunger tip 5 plunger 6 fixed platen 7 movable platen 8 tie bar 9 tie bar nut 10 side gate 11 cavity 12 circular gate 12a circular gate exit surface 13 pool 14 gap 15 Circular gate outlet 16 Reservoir insert 17 Piston 18 Cylinder 19 Cutting pin 20 Piston 21 Cylinder 22 Molten metal 23 Oxide film 24 Ladle 25 Biscuit

Claims (4)

[Claims] A lower fixed mold, an upper movable mold, an injection device below the fixed mold, and a circular gate having the same diameter as an inner diameter of a casting sleeve provided in the fixed mold; A movable mold having a recessed position, which is concentric with the circular gate, has an entrance diameter slightly larger than the diameter of the circular gate, and has a recess-shaped reservoir having an opening at a lower portion above the circular gate on the movable mold side; The gap between the mold and the fixed mold is provided at a position slightly lower than the side gate, so that the oxide film on the surface of the molten metal rising from the circular gate during casting is sealed in the basin and no oxide is mixed into the product. Vertical casting method to obtain good quality cast products. 2. An injection device is provided below the lower fixed die, the upper movable die, and the fixed die, and the fixed die is provided with a circular gate having the same diameter as the inner diameter of the casting sleeve. In the upper part of the same shape as this circular gate, there is a concave-shaped reservoir with an inlet diameter slightly larger than the circular gate diameter and an open bottom at the top of the circular gate, and slides up and down with the movable mold. At the start of casting, the lower end surface of the insert is brought into contact with the lower fixed mold to eliminate the passage of the molten metal and seal the oxide film on the surface of the molten metal in the reservoir without starting to flow out. After filling the molten metal into the basin, the nest is raised to open the molten metal passage, and the molten metal without oxide film is sent to the cavity to obtain a cast product of good quality with no oxide in the product. Vertical casting method. 3. An injection device is provided below the lower fixed die, the upper movable die, and the fixed die, and the fixed die is provided with a vertical circular gate having a diameter smaller than the inner diameter of the casting sleeve. A pin having a diameter slightly smaller than the inner diameter of the circular gate is slidably provided on the movable mold so that the pin can be moved up and down in the circular gate. In which the inlet diameter is slightly larger than the circular gate diameter at the upper part concentric with the circular gate of the movable mold and the lower part of which is open at the upper part of the circular gate. A reservoir is provided on the movable mold side, and a gap formed between the fixed mold and the movable mold is provided at a position slightly lower than the side gate so that a cast product of a quality from a circular gate can be obtained at the time of casting. Vertical casting method. 4. An injection device is provided below the lower fixed die, the upper movable die and the fixed die, and a vertical circular gate having a diameter smaller than the inner diameter of the casting sleeve is provided in the fixed die. In the upper part of the movable mold, which is concentric with the circular gate, an inlet diameter is slightly larger than the circular gate diameter, and the upper part of the circular gate has a concave-shaped reservoir with a downward opening, and is vertically moved between the movable mold and the movable mold. At the start of casting, the lower end of the insert is brought into contact with the lower mold to eliminate the passage of the molten metal and to prevent the oxide film on the surface of the molten metal from flowing out to the inside of the reservoir. After filling and filling the molten metal into the basin, raise the insert to open the molten metal passage and send out the molten metal without an oxide film.The diameter of the insertion part into the circular gate at the center of the insert is slightly smaller than the inner diameter of the circular gate. A small-diameter pin is slidably provided so that the pin can be moved up and down inside the circular gate. Vertical casting method in which the feeder is finally cut at the position of the gate to obtain a cast product of good quality with no oxide in the product.