JP3169107B2 - 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 mainly relates to a method in which a light alloy material is heated to a semi-molten state, and
The present invention relates to a molding apparatus that presses with a punch that can be inserted into the die hole, flows into a cavity formed in a molding die, and solidifies and molds in the cavity.

[0002]

2. Description of the Related Art The working method of press-feeding a metal heated in a semi-molten state into a cavity provided in a forming die by using a punch and a die is performed by the applicant in order to replace the conventional thixo-casting method. This is a relatively recently developed processing method. In other words, a billet of a metal material is rapidly heated from room temperature, and then heated at a slower rate in a high temperature region near its melting point, and then heated, then housed in a die hole, pressed with a punch, and pressed. It is formed by flowing into a cavity and molded by the applicant (Japanese Patent Application No. Hei.
89365).

[0003] Further, the applicant has found that when such a heating method in which heating near the melting point is performed slowly is performed in the atmosphere, an extremely thick oxide reaching several millimeters is generated on the surface of a billet as a material. When the molding method is carried out, the oxide is mixed into the material in a semi-molten state and flows into the cavity, thereby deteriorating the quality of the product. Means are proposed one by one (Japanese Patent Application No. Hei 4-15283).
No. 6).

[0004]

In such a forming method, it is essential that the material is heated to a high temperature near its melting point and that the heating operation near the melting point is carried out slowly and slowly. Therefore, when such a heating step and a transporting step of transferring the metal material after being heated to a semi-molten state to a die are performed in the atmosphere, the chance of contact between the material metal and air increases, and the above-described large amount of It has been difficult to avoid the problem that the oxide adheres.

Also, once an oxide film has been formed on the surface of a material during the manufacturing process, it is not always easy to separate and remove the oxide film. Since there is no way to reuse the material and it has to be discarded, the yield of the material has decreased, which has contributed to an increase in product cost.

[0006] Of course, such a problem of oxidation can be avoided by performing the step of heating the material metal and the step of transferring the material metal to the die in an inert gas atmosphere. However, it is necessary to specially provide equipment for creating such an inert atmosphere, and since the area requiring the inert atmosphere is large,
It required a large amount of capital investment.

[0007] On the other hand, as a result of the research, the applicant has found that even if the oxide film flowing into the cavity together with the metal material is mixed into the product and confined inside the product, the oxide of the oxide is not aggregated but finer. It was found that the product had an effect of imparting excellent mechanical properties to the product, as well as almost no reduction in the strength or other quality of the product. Therefore, it was considered that the oxide film was positively sent into the cavity.

However, even in this case, when the billet supplied to the die hole is pressurized by the punch, first, before being pushed into the flow path leading to the cavity, the length is reduced and the thickness is increased. Since the oxide film adhered to the surface of the billet is pressed against the inner surface of the die hole, the oxide film does not flow even if the billet itself starts flowing into the flow path, and it is difficult to flow into the cavity. Furthermore, there was a problem that the oxide film flowed in a nodular form, for example, it started flowing at a time when the flow of the unoxidized portion of the punch reached the end of the process and was finished.

[0009]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention relates to a die and a die.
A punch capable of moving back and forth into the die hole,
On the wall of the die hole located in front of the
A die that opens the flow path leading to the
Metal material pressed from the back by the punch on the wall of the hole
Of the molten metal forming device
While the surface is an inclined surface inclined toward the opening of the flow path,
Branch the downstream side of the flow path into a plurality and connect to the cavity
It is characterized by having done.

[0010]

[Action] When a billet as a metal material is heated to a semi-molten state, an oxide film is adhered to the surface, and when the billet is stored in the die hole and pressed with a punch, the tip of the billet is When supported by the support surface, it receives a strong compressive force and, when plastic deformation occurs, starts flowing smoothly into the flow path along the inclined surface that is inclined toward the flow path leading to the cavity.

That is, since the force of pressing the oxide film against the wall surface of the die hole is weakened as compared with the case where the support surface is not inclined, the frictional force against the oxide film is reduced.
Thus, the oxide film smoothly flows into the flow path together with the unoxidized base material portion and slides on the inclined slope toward the cavity. At this time, the oxide film is torn by friction with the inclined surface to be finely divided into pieces, and is gradually and uniformly dispersed while being caught in the base material portion.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. In the figure, reference numeral 10 denotes a semi-molten metal forming apparatus utilizing the present invention. The molding apparatus 10 includes an extruding means 20 for extruding a billet, which is a material 15 heated to a semi-molten state.
And a series of means for the material 15 pushed into the flow path 30 by the pushing means 20 to reach the cavity of the mold as the molding die 40 to be commercialized.

The extruding means 20 comprises a die 21 forming the upper part of the molding apparatus 10 and a punch 22. The die 21 is provided with a circular die hole 21a that opens upward, and the die hole 21a is located in front of the punch 22 in the traveling direction, and has an inverted conical-shaped inclined wall whose central portion is low, that is, , An inclined surface 21b is formed, and one end of the flow path 30 is opened at the center of the inclined surface 21b. An arc-shaped chamfer 23 that protrudes outward over the entire circumference is applied to the circular edge portion where the inclined surface 21b and the flow path 30 are connected so that no corner is formed, and the surface is smoothly finished. ing.

The channel 30 is formed by the pushing means 20 as described above.
And the inside of the cavity 41, and has a circular cross section. Channel 30
Has an open end on the inclined surface 21b, and the other end is branched into at least two parts by a branch part 31, or communicates with the cavity 41 through a bent part 32 bent at a substantially right angle.

The branch portion 31 has a substantially T shape.
The flow direction of the material 15 is bent at right angles and branched. The corner formed in the bent portion 32 is configured to perform an auxiliary function of dispersing the oxide film into the unoxidized portion. Further, the auxiliary function is not limited to this, and can be achieved simply by a simple structure in which the flow path 30 is bent at a right angle. That is, the flow path 3
The bent portion 32 formed at 0 shows an example of bending at such a right angle.

However, as shown in this embodiment, the other end of the branched flow path 30 is not limited to being connected to a common cavity 41 for a single product, as shown in FIG. And different cavities 4 for different products
This also includes the case where a branch is made so as to be connected to 1. In addition,
FIG. 2 shows another embodiment, and the same parts as those of this embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The mold 40 is configured as a split mold that is divided into two or more. Inside the mold 40, there is formed a cavity 41 which has a substantially similar inner surface slightly larger than the outer surface shape of the product. 42 is a cavity 41
An ejector pin for separating a product molded in the inside and cooled and solidified from the mold 40. The plurality of ejector pins 42 are supported by support means 43, and they are configured to integrally move toward and into the cavity 41.

Next, the operation of this embodiment will be described. First, the billet of the aluminum alloy as the raw material 15 is heated to a semi-molten state, that is, a temperature at which a liquid phase is generated. In this embodiment, the billet has a cylindrical shape with a diameter of about 70 mm and a height of 150 mm. This heating is performed relatively quickly until immediately before the liquid phase is formed, and relatively slowly after reaching the temperature at which the liquid phase is formed.
(Liquid phase ratio 30%) when it reaches the die hole 21a.
Transfer to By performing the heating or the subsequent transfer in the atmosphere, a thick oxide film generally reaching about 2 mm is formed on the surface of the material 15.

The billet 15 as a material is transferred by a transfer robot (not shown). And billet 15
Is a circular die hole 2 formed upward in the die mold 21.
When inserted into 1a, the punch 22 subsequently descends,
The upper surface of the billet 15 is strongly pressed. The billet 15 is deformed according to the inner surface of the die 21 and moves toward the flow path 30 opened at the center of the inclined surface 21b.

The inclined surface 21b of the die hole 21a has an inverted conical shape, and the edge portion connected to the flow path 30 is smoothly finished in an arc shape without corners. As a result, there is little deformation in the radial direction and the fluid smoothly flows into the flow path 30. Then, the billet 15 in the semi-molten state flows into the flow path 30 together with the oxide film adhered to its surface. At this time, when the oxide film slides on the inclined surface 21b, the oxide film is torn by friction and becomes finer. , And are uniformly dispersed throughout.

The material 15 is deformed and flows into the channel 30,
When reaching the branch portion 31 or the bend portion 32 provided between the flow die 21 and the cavity 41, when passing through the branch portion 31, the inner corner portion receives resistance, and the mixed oxide is further reduced. While crushing finely, the material 15 itself is greatly deformed and generates heat, which increases the fluidity and efficiently crushes the crushed oxide into the inside, and then when the material 15 flows through the inclined surface 21 b and the flow path 30, Dispersion of the mixed oxides due to friction with the wall surface becomes finer and more uniform.

A flow path 30 is formed on the wall surface of the die hole located in front of the punch 22 in the traveling direction, and the periphery of the flow path 30 is attached to the surface of the material 15 by a simple structure having an inclined surface facing the flow path. The oxide that has entered 21 a is pressed by the punch 22 and abuts on the inclined surface 21 b located forward together with the material 15, and is guided by it to flow smoothly into the flow path 30 and fill the cavity 41. Therefore, the material yield is better than that of a conventional apparatus that performs molding without oxides, which can greatly contribute to reduction in product cost. Oxide flowing into the flow path 30 together with the material 15 oxidizes the surface when the oxide flows toward the flow path 30 while rubbing the inclined surface 21 b or passes through the branch portion 31 or the bent portion 32 of the flow path 30. The material is rubbed against the wall surface of the flow channel 30 to be fine, and the material 15
Dispersed and mixed into the unoxidized part of the product, so the presence of oxides in the product material does not become a drawback, but also improves its mechanical properties such as self-lubrication and abrasion resistance Can be done.

In the above embodiment, the metal material 1
5 shows an example using an aluminum alloy, but the present invention is not limited to this, and it is needless to say that the present invention can be applied to the molding of other light alloys, iron, and many other metals having a melting point.

[0024]

As described above, according to the present invention, the yield of materials is good and the product cost can be greatly reduced as compared with the conventional apparatus which removes oxides and performs molding. Also,
When passing through the branch of the flow channel, the oxide on the surface is rubbed against the wall surface of the flow channel and is fragmented, and is dispersed and mixed into the unoxidized portion of the material. This has the effect of improving mechanical properties such as abrasion.

[Brief description of the drawings]

FIG. 1, showing an embodiment of the present invention, is a cross-sectional view of a mold for forming a semi-molten metal.

FIG. 2 is a sectional view of a mold corresponding to FIG. 1 showing another embodiment.

[Explanation of symbols]

 Reference Signs List 10 molding device 15 billet 20 extrusion means 21b die 21b inclined surface 22 punch 23 arc-shaped chamfering 30 ································································· Mold

Claims (3)

(57) [Claims] 1. A die having a die and a punch capable of moving back and forth into a die hole formed in the die, wherein a flow path leading to a cavity is opened in a wall surface of the die hole located in front of the punch in a traveling direction. In a molding apparatus for semi-molten metal in which a wall surface of a die hole in which the flow path is opened is a support surface of a metal material pressed from behind by a punch, an inclined surface whose support surface is inclined toward an opening of the flow passage And while
A molding apparatus for semi-molten metal, wherein the downstream side of the flow path is branched into a plurality of parts and connected to a cavity . 2. The apparatus for forming a semi-molten metal according to claim 1, wherein a bent portion which is bent at a substantially right angle is provided in the middle of said flow path. 3. A semi-molten metal forming apparatus according to claim 1, wherein an arc-shaped chamfer bulging outward over the entire periphery is formed on a peripheral edge of a flow path opened to a bottom surface of said support surface.