JPH07246450A - Die casting product and die device - Google Patents

Abstract

PURPOSE:To obtain a die casting product having high quality without shrinkage and warp by securing uniform flow of molten metal regardless of the setting positions of a sprue and a gas exhaust passage. CONSTITUTION:High parts and low parts of the flow resistance of the molten metal are alternately constituted on a forming surface 12a of either one of a fixing die or a movable die 12 by successively forming square-shaped die recessed parts 23 and projecting parts 24 so as to widen by mutually adjoining. One side direction of these square-shaped die recessed parts 23 and due projecting parts 24 is inclined to the pouring direction D of the molten metal and thereby, the poured molten metal is uniformly filled up into each part in a cavity formed with the fixing die 11 and the movable die 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to die-cast molding of a thin-walled structure, and more particularly to one having improved uniformity of molten metal flow.

[0002]

2. Description of the Related Art Die casting is a casting method in which molten metal is injected into a mold at high pressure, and the dimensional accuracy of the product is high.
Since it has high mass productivity, it has been used for various products.

Here, when the high-temperature and high-pressure molten metal is injected into the cavity formed by the fixed die and the movable die of the die casting die apparatus, the molten metal is uniformly filled in each portion in the cavity. Need to be done.

However, the gas in the cavity may remain in the product without being completely exhausted to form a cavity in the product. On the other hand, for example, conventionally, a mold gas venting means is provided in the gas exhaust path of the mold, and an openable / closable valve that can close the gas exhaust path is provided to prevent the inertial force of the molten metal during injection from increasing. By action, this valve is closed. According to this, since the gas in the cavity is forcibly discharged, it is possible to obtain an injection product without cavities.

[0005]

However, since the die-cast molding is to inject molten metal into the cavity of the mold at high speed and high pressure, it is necessary to discharge the gas in the cavity by the mold degassing means. However, the molten metal has a strong tendency to flow linearly from the gate into which the molten metal is injected to the gas discharge passage.

Such non-uniformity of molten metal flow causes minute shrinkage or warpage in the product, and depending on the product, such minute shrinkage or the like is not allowed, and therefore correction work is required. There is a problem that extra man-hours are required and the product itself becomes defective.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a uniform molten metal flow regardless of the installation location of the sprue and the gas discharge passage. By securing it, it is to obtain a high-quality die cast molded product without shrinkage or warpage.

[0008]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a thin-walled structure in which molten metal is injected into a cavity formed by a fixed mold and a moving mold, and pressure is applied to mold the molten metal. The die-cast molded article is characterized in that a rectangular concave portion and a convex portion are continuously formed so as to spread adjacent to each other on either one of the thin front and back surfaces.

Further, the molding of this molded product is carried out by injecting molten metal into a cavity formed by a fixed mold and a moving mold and applying pressure to mold it into a thin-walled structure in the die casting mold device. A rectangular mold concave portion and a mold convex portion are continuously formed so as to spread adjacent to each other on one of the molding surfaces of the mold or the moving mold, and the rectangular mold concave portion and the mold convex portion are formed. It is advisable to use a die casting mold device characterized in that the direction of one side is inclined with respect to the pouring direction of the molten metal.

Further, in the molding of the molded product, in the die casting molding method of injecting molten metal into a cavity formed by a fixed mold and a moving mold and applying pressure to mold into a thin-walled structure, On the molding surface of either the mold or the moving mold, a rectangular mold concave portion and a mold convex portion are continuously formed so as to spread adjacent to each other, and a portion having a large flow resistance and a portion having a small flow resistance are formed. By alternately arranging, and by inclining the direction of one side of the square-shaped mold concave portion and mold convex portion with respect to the molten metal injection direction, the injected molten metal is uniformly filled in each portion in the cavity. The die-cast molding method is characterized by the above.

[0011]

In the present invention thus constructed, first,
The moving mold is fitted to the fixed mold and the mold is clamped to form a cavity into which the molten metal is injected. Next, the molten metal in the heated state is injected at high temperature and high pressure to perform pouring. The injected molten metal is injected into the cavity.

The molten metal injected into the cavity has a portion having a large flow resistance and a portion having a small flow resistance, which is formed by continuously forming a rectangular die concave portion and a die convex portion on the molding surface of the die. Alternately proceed. As a result, the molten metal is extremely uniformly filled in the respective parts of the cavity while spreading two-dimensionally. Next, after the mold is opened between the fixed mold and the movable mold, the mold is peeled off, and a high-quality die cast molded product without shrinkage or warpage is molded.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a schematic vertical sectional view of a die casting mold apparatus according to an embodiment of the present invention, FIG. 2A is a view of the moving mold shown in FIG. 2C is a partially enlarged view of the molding surface of the moving mold, and FIG. 2C is a sectional view taken along the line BB of the moving mold.

As shown in FIG. 1, the die casting mold apparatus of this embodiment has a fixed mold 11 and a movable mold 12,
They are attached to the fixed platen 13 and the movable platen 14, respectively.

The movable platen 14 is constructed so as to be movable in the horizontal direction in the figure by a driving means (not shown). By moving the movable platen 14 toward the fixed platen 13, the movable mold 12 is fitted to the fixed mold 11,
The mold is clamped.

With this mold clamping, a cavity 15 into which molten metal is injected by the fixed mold 11 and the moving mold 12.
Is formed. Further, the introduction path 16 communicating with the gate 17 for injecting the molten metal, and the cavity 15 before forming
A gas discharge passage 18 is formed for discharging the gas existing therein.

A nozzle 19 is attached to the inlet of the introduction passage 16. The present embodiment is of a hot chamber type, and the pressurizing chamber (not shown) connected to the nozzle 19 is always heated by a heat retaining furnace (not shown) attached to the present apparatus. When pouring, the nozzle 1
Molten metal is injected from 9 at high temperature and high pressure.

In the case of this embodiment, this molten metal is
Uses magnesium alloy. Since magnesium alloy is lightweight and has high strength, it can be made light and thin, and it also has the effect as an electromagnetic shield, is recyclable, and has good heat dissipation properties. It is used a lot. For example, JIS standard M
DI1D (magnesium alloy ingot for die casting, type 1D) is used, and the chemical composition of this ingot is Al: 8.5-
9.5%, Zn: 0.45-0.9%, Mn: 0.17% or more, S
i: 0.08% or less, Cu: 0.015% or less, Ni: 0.001%
Hereinafter, Fe: 0.004% or less, and the balance is Mg. The molten metal is not limited to the magnesium alloy, and other materials such as aluminum alloy can be used in the present invention.

The gas discharge passage 18 is provided with a mold degassing means 21. This mold degassing means 21
Is a well-known technique, which has a gas discharge valve (not shown), and the molten metal injected into the cavity 15 of the mold at a high speed causes only the gas in the cavity 15 to pass through the valve to the outside. The valve is automatically closed by the action of a large inertial force of the molten metal that has been discharged into the gas and subsequently entered into the gas to prevent the molten metal from leaking to the outside. Further, a plurality of extruding pins 22 ... Are provided,
The mold of the molded product is used at the time of peeling.

As shown in FIG. 2A, the moving die 12
An introducing passage 16 for guiding the molten metal ejected from the nozzle 19 is formed in the T-shaped groove. The cavity 1 formed by the molding surface 12a of the movable mold 12 and the molding surface 11a of the fixed mold 11 from the introduction path 16
Gate 1 for injecting molten metal into 5 (see FIG. 2 (c))
7 are provided at 4 places. On the other hand, two gas exhaust ports 25 are provided at the end portion on the opposite side of the molding surface 12a so as to face the gates 17, and communicate with the gas exhaust passage 18. In addition, the number of the gates 17 and the gas exhaust ports 25 installed is appropriately set depending on the product.

In the present embodiment, in particular, as shown in FIG. 2A, the mold concave portion 23 and the mold convex portion 24 (see FIG. 2) are spread on the molding surface 12d of the movable mold 12 so as to be adjacent to each other. Two
(See (b)) are continuously formed.

The mold concave portion 23 and the mold convex portion 24 formed on the molding surface 12a of the movable mold 12 are shown in FIGS.
As shown in FIG. 3, the shape of the mold is a rectangular shape.
It is formed so as to be inclined with respect to the injection direction D of the molten metal from 7 toward the gas outlet 25.

As described above, in the thin-walled die casting mold device, a portion having a large flow resistance (a portion corresponding to the mold concave portion 23) and a portion having a small melt flow resistance (a portion corresponding to the mold convex portion 24) are alternately formed. As a result, the molten metal alternately advances through the portions having a large flow resistance and the portions having a small flow resistance, and as shown by the arrow in FIG. Each part of is uniformly filled.

The length of one side of the rectangular mold concave portion 23 and the mold convex portion 24 and the inclination angle with respect to the injection direction D are set to a length of 30 mm and an inclination angle of 45 °, but are not limited thereto. However, it can be set appropriately. Therefore, in the present embodiment, the shape of the mold concave portion 23 and the mold convex portion 24 is formed into a substantially square shape as shown in FIG. 2B, but the shape is not limited to this and may be a square shape. For example, the shape may be a rhombus or a rectangle, and the corners of a quadrangle may be formed in a predetermined R shape.

FIG. 3 (a) is a schematic perspective view of a die-cast molded product molded by using the die-cast mold device shown in FIG. 1, and FIG. 3 (b) is a C-shaped die-cast molded product.
It is sectional drawing which follows the C line.

The die-cast molding 31 is used, for example, as a case member of precision equipment, and corresponds to the mold recess 23 formed on the molding surface 12a of the movable mold 12 on the inner surface of the bottom wall 32. Then, the convex portion 33 and the concave portion 34 corresponding to the die convex portion 24 are formed. In this embodiment, the thickness of the convex portion 33, that is, the standard thickness t is about 2 mm, and the step d between the convex portion 33 and the concave portion 34 is about 0.2 mm.
Is set to. However, the standard thickness t and the step d
Is appropriately set according to product specifications and the like. On the other hand, the bottom wall 32
The outer surface, that is, the lower surface in the figure, can be formed into an extremely smooth surface without unevenness, and when finished as a product, a predetermined surface treatment or the like is performed.

Next, the operation of this embodiment will be described. First,
By moving the movable platen 14 toward the fixed platen 13, the movable mold 12 is fitted to the fixed mold 11, and the mold is clamped. The state of FIG. 1 shows the state after mold clamping, and the fixed mold 11 and the movable mold 12 form a cavity 15 into which molten metal is injected.

Next, the molten metal in a heated state is injected from the nozzle 19 toward the introduction path 16 at high temperature and high pressure, whereby pouring is performed. The injected molten metal is injected into the cavity 15 from the sprue 17 through the introduction passage 16.

Here, only the gas in the cavity 15 is first discharged to the outside by the mold degassing means 21 by the molten metal injected at a high speed, and the molten metal that has subsequently entered the gas is Due to the action of inertial force, a valve (not shown) is automatically closed to prevent leakage to the outside.

The molten metal injected into the cavity 15 from each sprue 17 alternately has a portion having a high melt flow resistance (a portion corresponding to the mold concave portion 23) and a small portion (a portion corresponding to the mold convex portion 24). Proceed to. As a result, the molten metal is uniformly filled in each portion inside the cavity 15 while spreading two-dimensionally as shown by the arrow in FIG.

Next, the movable platen 14 is moved to the right in the figure by a driving means (not shown) to open the mold, and the push-out pin 22 is operated to peel off the mold. In this way, the die cast molding 31 as shown in FIG. 3 is molded.

As described above, in the die casting mold apparatus of the present embodiment, the rectangular mold concave portion 23 and the mold convex portion 24 are spread on the molding surface 12a of the movable mold 12 so as to be adjacent to each other.
Since the molten metal is formed continuously, the portions having large and small molten metal flow resistances are alternately arranged, and moreover, the direction of one side of the rectangular mold recess 23 and the mold projection 24 is set with respect to the pouring direction of the molten metal. Since the molten metal is inclined, the molten metal alternates between the portion having a large melt flow resistance and the portion having a small melt flow resistance. Therefore, the molten metal can be extremely uniformly filled in each portion in the cavity 15 while being diffused two-dimensionally.

Therefore, unlike the prior art, the molten metal is not linearly flowed from the spout to the gas discharge path to cause non-uniformity of the molten metal flow, and high quality die casting without shrinkage or warpage. You can get the goods. In addition, extra man-hours for correction work are unnecessary, and product defects are reduced, so that productivity is significantly improved. Moreover, since the rectangular recess and protrusion are continuously formed in the molded product, the rigidity is enhanced. That is, the ribs can be partially omitted, and therefore, the dents and strains caused by the ribs can be avoided.

It should be noted that the embodiments described above are described for facilitating the understanding of the present invention, and not for limiting the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design changes and equivalents within the technical scope of the present invention.

For example, in the above-mentioned embodiment, the present invention has been described by taking hot chamber type die casting as an example, but the present invention is also applicable to a cold chamber type.
In addition, the mold concave portion 23 and the mold convex portion 24 are
Although they are continuously formed so as to spread adjacent to each other, the present invention is not necessarily limited to strictly continuous ones. For example, while separating the mold protrusions 24 by a slight distance. It is also possible to form so as to spread over the whole.

[0036]

As described above, according to the present invention, it is possible to fill the respective portions in the cavity extremely uniformly while allowing the molten metal to diffuse two-dimensionally. Therefore, unlike the conventional case, the molten metal does not flow in a straight line to cause non-uniformity of the molten metal flow, and it is possible to obtain a high-quality die cast molded product without shrinkage or warpage. In addition, extra man-hours for correction work are unnecessary, and product defects are reduced, so that productivity is significantly improved. Moreover, since the rectangular recess and protrusion are continuously formed in the molded product, the rigidity is enhanced. That is, the arrangement of the ribs can be partially omitted, and therefore, it is possible to avoid the dents and strains caused by the ribs.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a die casting mold device according to an embodiment of the present invention.

2A is a view of the moving mold shown in FIG. 1 viewed from the direction A, FIG. 2B is a partially enlarged view of the molding surface of the moving mold, and FIG. 2C is the same moving mold. It is sectional drawing which follows the BB line of a type | mold.

3 (a) is a schematic perspective view of a die-cast molded product molded by using the die-cast mold device shown in FIG. 1, and FIG. 3 (b) is a sectional view of the same die-cast molded product taken along the line C-C. It is a figure.

[Explanation of symbols]

11 ... Fixed mold, 12 ... Moving mold, 15 ... Cavity, 23 ... Mold concave part, 24 ... Mold convex part, 31 ... Die cast molded article, 33 ... Projection part, 34 ... Recessed part, D ...
Direction of molten metal injection.

Claims (3)

[Claims] 1. A die-cast molded product having a thin-walled structure formed by injecting molten metal into a cavity formed by a fixed mold and a moving mold and applying pressure to the mold, wherein either one of the front and back surfaces of the thin wall is formed. A die-cast molded article, characterized in that a rectangular concave portion and a convex portion are continuously formed so as to spread adjacent to each other. 2. A die casting mold apparatus for injecting molten metal into a cavity formed by a fixed mold and a movable mold, and applying pressure to mold the structure into a thin-walled structure. On either molding surface,
The rectangular mold concave and convex parts are continuously formed so as to spread adjacent to each other, and one side of the rectangular mold concave and convex parts is inclined with respect to the molten metal injection direction. A die-casting mold device characterized by being made. 3. A die casting molding method in which molten metal is injected into a cavity formed by a fixed mold and a movable mold, and pressure is applied to mold into a thin-walled structure, wherein either the fixed mold or the movable mold is used. On one molding surface,
The rectangular mold concaves and convexes are continuously formed so as to spread adjacently to each other, and the portions having large and small melt flow resistance are alternately formed. The die casting method according to claim 1, wherein the direction of one side of the portion is inclined with respect to the injection direction of the molten metal so that the injected molten metal is uniformly filled in each portion in the cavity.