JP3126823B2 - Semi-molten metal forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semi-molten metal forming apparatus which mainly heats a light alloy to a semi-molten state, puts it into a die, presses with a punch, and feeds the light alloy to a cavity formed in a mold. And a device for reducing oxides mixed in the material sent from the die to the cavity as much as possible.

[0002]

2. Description of the Related Art In general, a molding method in which a metal material is heated to a semi-molten state, and is pressed by a punch and a die and fed into a mold is already known. One of the issues with this type of technology is that when the material is heated to a semi-molten state, the oxide film attached to the surface enters the mold with the material,
The purpose is to prevent oxides from being mixed in the composition of a product to lower its quality, and various improvements have been made to improve this.

That is, these techniques are roughly classified into two types. One is to carry out all steps from a heating step to a pressure forming step in a molding chamber in an inert gas atmosphere. There is an attempt to remove an oxide film during molding (for example, Japanese Patent Publication No. 2-51703).

[0004] However, the former is excellent in achieving the purpose of avoiding the formation of an oxide film in the heating process, but has the disadvantage that the apparatus becomes large and the operating cost increases. The latter is extremely excellent in that it can avoid the enlargement of the equipment and excessive initial investment, but at present, there are many points to be improved in the details of the process and equipment, in which the applicant has previously mentioned. As shown in FIG. 5, a recess P for drawing an oxide film is formed in a punch P entering a die hole D, or a runner R opening in the die hole D as shown in FIG.
(Japanese Patent Application Nos. 4-89366 and 4-15).
No. 2835).

[0005]

However, there is no epoch-making method for solving this problem at once.
Steady improvements are required.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an unprecedented apparatus for minimizing the problem that the oxide film adhering to the outer peripheral surface of the billet B is drawn into the runner R as much as possible. A punch for pressing a billet inserted into a die hole, and a runner for guiding the billet pressed by the punch to the cavity from the bottom of the die hole to a cavity of a semi-molten metal forming apparatus, wherein: Multiple irregularities on the wall in a direction substantially perpendicular to the axis
There is a characteristic in the point formed. The recess may be a groove. Ma
The projection may be a hemispherical projection.

[0007]

When a billet is inserted into a die hole and pressed with a punch, a non-oxidized material having good fluidity and being in a semi-molten state breaks an oxide film on the surface and flows into the runner. At this time, the oxide film adhered to the surface of the billet is strongly pressed against the surface of the uneven die hole by the pressure of the non-oxidized material inside. As a result, part of the oxide film escapes into the concave portion, so that even if the punch advances, it does not move in the advancing direction and remains in the die hole. When the pressing process of the billet by the punch reaches the end, most of the material in a semi-molten state with good fluidity flows into the runner, but the oxide film does not flow into the runner until this time, and it enters the die hole. Stop.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows a molding machine 1 for semi-molten metal. The molding machine 1 comprises a press machine comprising a punch 2 and a bed 3 and a mold 4 mounted on the bed 3. The mold 4 is composed of a lower mold 4a and an upper mold 4b which can be divided into upper and lower parts. The upper mold 4b is further composed of a left and right two-part mold, and a cavity 5 is formed therein. 4 c is a pin forming a part of the cavity 5. Reference numeral 6 denotes a die hole formed in the upper end surface of the mold 4, and the bottom thereof communicates with the cavity 5 through a runner 7. B is a billet made of aluminum as a material.

Next, a general molding process will be outlined with reference to FIG. First, the billet B is heated to 560 ° C. by a high-frequency heating device (not shown). At this time, the aluminum alloy is in a semi-molten state, that is, a state in which a liquid phase and a solid phase are mixed. The proportion of the liquid phase at this temperature is about 46%. The billet B in this state is inserted into the die hole 6 as shown in FIG. In the billet B, the unoxidized portion B2 inside has a higher fluidity than the oxide film B1 on the surface. Therefore, when the punch 2 comes into contact with the top surface of the billet B as shown in FIG. The unoxidized portion B2 breaks through the oxide film B1 on the surface and flows into the runner 7. In this case, the cavity 5 is somewhat cooled by the die holes 6 and the runners 7, and the cavity 5 is filled without deteriorating the fluidity due to the heat generated by the plastic deformation received when passing through the cavity (c). The time from when the billet B is extruded into the runner 7 to when the cavity 5 is filled is about 2 seconds. After filling, the molding is completed by applying a higher pressure for about 6 seconds (d). By this two-stage pressing, a product having a dense structure can be obtained.

FIG. 3 shows the inner surface of the die hole 6 according to the present invention.
As shown in the figure, the unevenness 6a is formed, and the lowering of the billet B is gently restrained. That is, in the illustrated example, the unevenness 6a is a screw groove formed on the inner surface of the die hole 6 and having a gentle inclination angle. The cross-sectional shape of the groove is quadrangular. Therefore, when the top surface of the billet B is strongly pressed by the punch 2, the oxide film adhering to the surface of the billet B is pressed and strongly pressed against the inner surface of the die hole 6. As a result, a part of the oxide film escapes into the concave portion forming the unevenness 6a, and the movement along the surface is prevented. Therefore, even if the punch 2 further descends, it does not accompany it and stops at that position.

The specific shape of the unevenness 6a is not limited to this embodiment, but has various modes. That is, the unevenness 6a is formed into a continuous groove 8 as shown in FIG. 3 and the innumerable hemispherical projections 9 as shown in FIG.
May be protruded. First, when the unevenness 6a is the groove 8, the direction of the groove 8 is not limited to the screw groove, but may be an annular groove.
The direction must be substantially perpendicular to the traveling direction of the punch 2, and if the angle is close to the traveling direction of the punch 2, the effect is almost nil. When the unevenness 6a is the groove 8, the groove 8
The cross-sectional shape of itself is also arbitrary. In the example of FIG. 3 , the shape is quadrangular, but may be triangular as shown in FIG. In the present embodiment, the width of the groove 8 was about 2 mm, and the depth was about 0.5 times the width. When the projections and depressions 6a are countless projections 9, as shown in FIG. 4B, the projections have a hemispherical shape with a diameter of about 1 mm . As a result , the oxide film
Removal was successful .

[0012]

As described above, the present invention provides a dieHole wall
Multiple irregularities formed on the surface in a direction substantially perpendicular to its axis
Because it ’s somethingWith oxide film layerIsMolded
When breadToOxide film is recessed by pressureConvex recess
And groovesInto the breadChi'sWith respect to the axial movement
Cause a large resistance,IsBreadToPressing
Oxidized parts are left behind whenAbsent
And diceInside the holeStop at. Therefore, the oxide film
It is possible to obtain molded products of excellent quality without
There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a sectional view of a molding machine .

FIG. 2 is a process chart showing a conventional molding process.

FIG. 3 is a sectional view of a die showing a main part of the present invention.

FIG. 4 (a) is an enlarged view of a main part showing a modification of the present invention.
is there. (B) An enlarged view of a main part showing another modification of the present invention.
You.

FIG. 5 is a cross-sectional view of a die according to a prior application example .

FIG. 6 is an enlarged view of a main part showing another prior application example.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B22D 18/02 B22D 17/00 B22D 17/20

Claims (3)

(57) [Claims] 1. A semi-molten metal forming apparatus comprising: a punch for pressing a billet inserted into a die hole; and a runner for guiding the billet pressed by the punch from the bottom of the die hole to a cavity. With the axis on the wall
An apparatus for forming a semi-molten metal having a plurality of irregularities formed in a direction substantially orthogonal to the metal. 2. The device according to claim 1, wherein said recess is a half of a groove.
Equipment for forming molten metal. 3. A projection according to claim 1, wherein said projection is a hemispherical projection.
An apparatus for forming a semi-molten metal, comprising: