JP4100821B2 - Injection molding equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an injection molding apparatus for injecting a material into a mold to produce a molded product, and more particularly to an injection molding apparatus for injecting a material in a low viscosity state.
[0002]
[Prior art]
At present, a great number of products, especially casing members, are made of resin by injection molding. From the viewpoint of environment and resource saving, it is desirable to make the casing from recyclable materials rather than difficult-to-recycle resins. ing. Therefore, the use of magnesium alloys is attracting attention. If magnesium alloy is used, it can be recycled, and it can be made thinner because it is stronger than resin, so it can be manufactured with a weight that is not much different from that of resin, especially when used for electronic equipment parts. Since the advantage of improving electromagnetic shielding is also obtained, the use of a magnesium alloy for an electronic device component has attracted particular attention.
[0003]
However, in the case of injection molding with a magnesium alloy, there is a problem that did not occur when injection molding with a resin. That is, when a magnesium alloy is melted for injection, the viscosity at that time leaks from a gap in a mold that is very low. In this way, the magnesium alloy that leaks from the gap between the molds that have been put together will then become hard to collect, making it difficult to separate the molds, and the next time the molds are put together, the result is that they do not fit exactly. The problem arises that the thickness of the product does not become as prescribed. As a method of solving this problem, there is a method of reducing the gap of a certain mold, but this increases the number of steps, and as a result, increases the cost.
[0004]
[Problems to be solved by the invention]
In view of the above problems, an object of the present invention is to provide an injection molding apparatus that can prevent a low-viscosity material from accumulating between mating surfaces of a mold at a low cost.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, the first bottom surface, the second bottom surface above the first bottom surface and parallel to the first bottom surface, and the first mold member first connecting the first bottom surface and the second bottom surface. A first mold member having a side surface and a first mold member second side surface extending upward from an end of the second bottom surface opposite to the first mold member first side surface;
A first lower surface slidable on the first bottom surface of the first mold member, a second lower surface slidable on the second bottom surface of the first mold member, and a first connecting the first lower surface and the second lower surface. A second mold member having a second mold member first side surface and a second mold member second side surface extending upward from an end opposite to the second mold member first side surface of the second lower surface;
Low viscosity in the gap between the first mold member second side surface and the second mold member second side surface formed when the distance between the first mold member first side surface and the second mold member first side surface is a predetermined amount. Injecting the conditioned material,
After the injected material is solidified to form a product, an injection molding apparatus that takes out the product by expanding the distance between the first side surface and the second side surface,
Forming a drain hole penetrating downward and downward from a portion of the first bottom surface of the first mold member adjacent to the first mold member first side surface;
A low-viscosity material that has entered between the second bottom surface of the first mold member and the second lower surface of the second mold member and reached between the first side surface of the first mold member and the first side surface of the second mold member. An injection molding apparatus is provided that discharges from the drain hole to the outside.
Such is configured injection molding apparatus enters the gap between the second lower surface of the second bottom surface and a second mold part of the first mold member, the first first side and a second mold part of the first mold member The low-viscosity material that has reached between the side surfaces is discharged to the outside through the drain hole. Therefore , between the second bottom surface of the first mold member and the second lower surface of the second mold member, the first of the first mold member The material accumulates between the one side surface and the first side surface of the second mold member, and between the first bottom surface of the first mold member and the first lower surface of the second mold member. Adhering to the second mold member is prevented.
[0006]
According to the second aspect of the present invention, in the first aspect of the present invention, the wall surface of the drain hole is separated from the extension line of the first side surface of the first mold member as it goes downward. The material does not adhere to the wall surface, and the material is recovered efficiently.
[0007]
In the third aspect of the invention, in the first aspect of the invention, in particular, a magnesium alloy is used for the injection material.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a view showing an embodiment of an injection molding apparatus of the present invention used when a magnesium alloy is used as an injection material.
Referring to FIG. 1, the first mold member 10 includes a first bottom surface 11, a second bottom surface 12, a first side surface 13 connecting the first bottom surface 11 and the second bottom surface 12, and a second side surface extending upward from the second bottom surface. 14 As a feature of the present invention, a drain hole 15 extending downward from a portion adjacent to the first side surface of the first bottom surface 11 is formed.
On the other hand, the second mold member 20 has a first lower surface 21, a second lower surface 22, a first side surface 23 connecting the first lower surface 21 and the second lower surface 22, and a second side surface 24 extending upward from the second lower surface. .
[0009]
The second mold member 20 is moved in the left-right direction in the drawing by means not shown, the first lower surface 21 of the second mold member 20 slides on the first bottom surface 11 of the first mold member 10, and the second lower surface 22. Slides on the second bottom surface 21 of the first mold member 10. FIG. 1 shows a state where the first side surface 23 of the second mold member 20 is in contact with the first side surface of the first mold member, and the second mold member 20 is in the leftmost position.
In this state, a gap A is formed between the second side surface 14 of the first mold member 10 and the second side surface 24 of the second mold member 20.
[0010]
The magnesium alloy melt is injected into the gap A by an appropriate means (not shown). This molten magnesium alloy has the same viscosity as water at normal temperature [magnesium viscosity is about 1.10 × 10 ⁻³ Pa · s at 700 ° C. (edited by the Japan Institute of Metals, Metal Data Book), and the viscosity of water is 20 About 1.002 × 10 ⁻³ Pa · s at ℃ (National Astronomical Observatory, Science Chronology)].
[0011]
On the other hand, each surface of the first mold member 10 and the second mold member 20 is finished with the same degree of accuracy as in the case of injection molding with resin, and the first bottom surface 11 and the second mold member of the first mold member 10 are finished. 20 between the first lower surface 21 of the first mold member 10, between the second lower surface 21 of the first mold member 10 and the second bottom surface 21 of the second mold member 20, between the first side surface 13 of the first mold member 10 and the second mold member 20. There is a gap of about ^{2 to} 3 × 10 ⁻² mm between the first side surfaces 23.
[0012]
Therefore, the magnesium alloy molten metal injected into the gap A between the second side surface 14 of the first mold member 10 and the second side surface 24 of the second mold member 20 is separated from the second lower surface 21 of the first mold member 10 and the second surface 21. The first mold member 10 passes through the gap between the second bottom surfaces 21 of the mold member 20 and then passes through the gap between the first side surface 13 of the first mold member 10 and the first side surface 23 of the second mold member 20. The first bottom surface 11 of the second mold member 20 and the first lower surface 21 of the second mold member 20 are about to enter the gap.
[0013]
However, since the drain hole 15 is formed according to the present invention, the molten magnesium alloy passing through the gap between the first side surface 13 of the first mold member 10 and the first side surface 23 of the second mold member 20 is drained. It is discharged to the outside through the hole 15. Here, as shown in the figure, the drain hole 15 is inclined to the left in the drawing so as to be away from the extension line of the first side surface 13 of the first mold member 10, and the diameter increases toward the lower side. It does not adhere by cooling and solidification on the wall surface of the hole 15.
Then, the magnesium alloy discharged to the outside from the drain hole 15 is recovered and reused.
[0014]
On the other hand, when there is no drain hole as in the present embodiment, the magnesium alloy melt accumulates and solidifies at the location marked with XXX in FIG. 2 and solidifies to form the first mold member 10 or the second mold member 20. Adhere to the surface.
As a result, for example, if the first side surface 13 of the first mold member 10 and the first side surface 23 of the second mold member 20 accumulate and solidify, the two cannot adhere to each other, and as a result, the gap A increases. As a result, the thickness of the product becomes large and stable molding cannot be performed.
[0015]
Further, between the first bottom surface 11 of the first mold member 10 and the first bottom surface 21 of the second mold member 20, or between the second bottom surface 21 of the first mold member 10 and the second bottom surface 21 of the second mold member 20. When the second mold member 20 is moved and solidified, galling occurs when the second mold member 20 is moved, and both the first mold member 10 and the second mold member 20 are damaged and durability is lowered. Further, burrs are likely to occur in a portion between the second lower surface 21 of the first mold member 10 and the second bottom surface 21 of the second mold member 20 that is continuous with the gap A.
[0016]
In the present embodiment, all the above-mentioned drawbacks are eliminated, stable molding can be performed, and the mold durability is improved.
[0017]
【The invention's effect】
According to the invention described in each claim, the low-viscosity material that has entered the gap between the first mold member and the second mold member is discharged from the drain hole, and stable molding can be performed. Also improves. Further, no particularly difficult processing is required, and this can be realized at a low cost.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a diagram for explaining a problem of a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... 1st type | mold member 11 ... 1st bottom face 12 ... 2nd bottom face 13 ... 1st side wall 14 (of 1st type member) ... 2nd side wall 15 (of 1st type member) ... Drain hole 20 ... 2nd type | mold member 21 ... 1st lower surface 22 ... 2nd lower surface 23 ... 1st side wall 24 (of 2nd type | mold member) ... 2nd side wall (of 2nd type | mold member)

Claims (3)

A first bottom surface, a second bottom surface above the first bottom surface and parallel to the first bottom surface, a first side surface of the first mold member connecting the first bottom surface and the second bottom surface, and a first of the second bottom surface A first mold member having a first mold member second side surface extending upward from an end opposite to the mold member first side surface;
A first lower surface slidable on the first bottom surface of the first mold member, a second lower surface slidable on the second bottom surface of the first mold member, and a first connecting the first lower surface and the second lower surface. A second mold member having a second mold member first side surface and a second mold member second side surface extending upward from an end opposite to the second mold member first side surface of the second lower surface;
Low viscosity in the gap between the first mold member second side surface and the second mold member second side surface formed when the distance between the first mold member first side surface and the second mold member first side surface is a predetermined amount. Injecting the conditioned material,
After the injected material is molded, an injection molding apparatus for taking out the product by expanding the distance between the first side surface and the second side surface,
Forming a drain hole penetrating downward and downward from a portion of the first bottom surface of the first mold member adjacent to the first mold member first side surface;
A low-viscosity material that has entered between the second bottom surface of the first mold member and the second lower surface of the second mold member and reached between the first side surface of the first mold member and the first side surface of the second mold member. An injection molding apparatus characterized by being discharged to the outside.   2. The injection molding apparatus according to claim 1, wherein a wall surface of the drain hole is separated from an extension line of the first side surface of the first mold member as it goes downward. 3.   2. The injection molding apparatus according to claim 1, wherein a magnesium alloy is used as the injection material.

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