JP3864685B2 - Aluminum wheel mold - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an aluminum wheel molding die provided with an extraction passage for residual gas in a cavity that is discharged as a molten metal is poured into a cavity.
[0002]
[Prior art]
9 is a sectional view of a vertical part of a conventional mold for forming an aluminum wheel, and FIG. 10 is a plan view seen from FF in FIG. In FIG. 9, the upper mold 4 is composed of an inner mold 42 positioned inside and an outer mold 44 positioned on the outer periphery of the inner mold 42. In addition, a gate cutting pin 9 is provided at the center of the inner mold 42, and an aluminum wheel product incorporated into the upper mold when the upper and lower molds are opened around the gate cutting pin 9 is released. In order to do this, push pins 76 are arranged at regular intervals on the inner mold 42 on a constant pitch circle.
[0003]
Further, between the outer peripheral surface portion of the inner mold 42 and the inner peripheral surface portion of the outer mold 44, the gas remaining in the cavity 10 is smoothly discharged out of the mold as the aluminum melt is poured into the cavity 10. In order to do so, a minute circular gap (gas vent passage) 78 was provided.
[0004]
[Problems to be solved by the invention]
However, there is a problem that there is no basic data for determining the size of the gap 78. That is, if the gap 78 shown in FIG. 10 is increased, the gas (air) in the cavity 10 can be easily released, but when the molten aluminum 11 is filled into the cavity 10, the molten metal 11 enters the gap 78, and finally When the filled molten metal 11 is solidified, the molten metal 11 that has entered the gap 78 is also solidified together. For this reason, since the molten metal 11 at the time of molding of the previous cycle remains solidified at the time of molding of the next cycle, the outgassing becomes incomplete, and these gases are mixed into the aluminum wheel product, resulting in product yield. There was a problem such as lowering.
[0005]
On the other hand, if the gap 78 is reduced, the gas (air) in the cavity 10 does not escape easily, and when the molten metal 11 is filled into the cavity 10, the gas is not sufficiently discharged outside the mold, and the residual gas enters the aluminum wheel product. There was a problem that the product yield was reduced due to the contamination.
[0006]
An object of the present invention is to provide a space for assisting the degassing while preventing the molten metal from being inserted into the degassing passage where the degassing is completely performed and the leading end of the degassing passage facing the cavity side. The object is to provide a mold for forming an aluminum wheel.
[0007]
[Means for Solving the Problems]
In order to solve such a problem, in the present invention, a cavity is provided between a lower mold having a gate part for casting a molten metal at the center and an upper mold provided to face the lower mold. In addition, a gate cutting pin disposed on the upper mold so as to be vertically slidable facing the gate portion, an inner mold disposed adjacent to the periphery of the gate cutting pin, and an inner mold. A push pin that pushes out the product attached to the upper mold, an outer mold disposed on the outer periphery of the inner mold, and an upper backup mold that holds both the inner mold and the outer mold and, the cavity f of the inner mold the gas remaining Ban connexion the cavity in the filling of the molten metal and gas vent passage and said inner mold from the gas vent passage provided between the outer mold provided on the inner mold Degassing provided between the mold and the extrusion pin It provided an extraction passage of the residual gas to be discharged to the upper die outside via a passage.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. In FIG. 1, 1 is a lower mold or a fixed mold, 2 is a design mold on the upper surface side of the lower mold 1, and 3 is a lower backup mold on the lower surface side of the lower mold 1, and is connected by a fastening bolt 24. Although not shown, it is attached to a lower mold holder or a fixed platen.
[0009]
Reference numeral 4 denotes an upper mold, and reference numeral 5 denotes a slide core of the upper mold 4, which is attached to an upper mold holder or a movable platen. 6 is an injection sleeve, 7 is an injection plunger, and 8 is a gate portion. FIG. 1 shows a closed state by a mold clamping device, and reference numeral 10 denotes a cavity 10 in the shape of an aluminum wheel formed between a lower mold 1, an upper mold 4 and a slide core 5. 11 is a molten metal such as an aluminum alloy that is cast and filled in the cavity 10 by the injection plunger 7.
[0010]
The lower backup mold 3 has a cylindrical recess 22 at the center, and the design mold 2 is fitted on the lower backup mold 3 so that misalignment between the design mold 2 and the backup mold 3 can be prevented. It has become. In addition, a ring-shaped cooling medium passage 12 is provided in the outer peripheral portion near the runner 30 at the bottom of the design die 2 that comes into contact with the lower backup die 3. The passage 12 is formed by combining a ring-shaped groove provided on the lower surface side of the design mold 2 and the upper surface of the lower backup mold 3, and between the ring-shaped cooling medium passage 12 and the outer periphery of the stationary mold 1. The coolant is communicated by a perforated cooling medium straight passage 12c.
[0011]
The cooling medium straight passage 12c is composed of two, one cooling medium straight passage 12c is provided with a cooling medium inlet, and the other cooling medium straight passage 12c is provided with a cooling medium outlet. Reference numeral 68 denotes a partition plate for forming a cooling medium flow passage so that the cooling medium introduced from the cooling medium inlet passes through a predetermined passage and is discharged from the cooling medium outlet through the cooling medium linear passage 12c. . Further, a lid 23 is welded to the design mold 2 so that the cooling medium does not leak to the outside on the lower backup mold 3 side of the cooling medium passage 12.
[0012]
On the other hand, the upper die 4 is provided above the lower die 1 so as to face the lower die 1 and is concentrically formed on the gate cutting pin 9 located at the center and on the outer periphery of the gate cutting pin 9 An inner mold 42 is provided, and an outer mold 44 is provided concentrically on the outer periphery of the inner mold 42. The inner die 42 including the gate cutting pins 9 and the upper backup die 58 that holds both the outer die 44 are configured. In addition, when the molten aluminum is cast into the cavity 10 between the slide core 5 and the outer mold 44 and the upper backup mold 58, a gas vent passage for discharging the residual gas in the cavity 10 to the outside of the mold. 100 is provided. Reference numeral 94 denotes a portion that becomes a rim portion of the aluminum wheel.
[0013]
Next, as means for cooling the upper mold 4, the cooling medium passage 62 is directly engraved in the upper mold 4 itself, and the cooling medium passage 62 is directly formed in the upper mold 4 as shown in FIGS. 3 and 4. There is a case where a separate jacket having the cooling medium passage 62 is disposed without engraving, but here, the case where the latter separate jacket is disposed will be described.
[0014]
First, the inner diameter side of the outer mold 44 is cut into the shape of a step 45, and a jacket 60 having a ring-shaped cooling medium passage 62 is disposed directly on the step 45. In this case, an engaging portion 43 in which the outer peripheral portion of the inner die 42 is formed in a stepped shape is provided, and the engaging portion 43 is engaged with the inner peripheral step portion of the outer die 44 so that the inner die 42 does not fall. It is configured as follows. On the cooling medium passage 62, a pit hole 52 is formed in the outer mold 44 in a direction corresponding to a spoke portion of the aluminum wheel.
[0015]
A partition plate 68 is disposed so that the inlet 66 of the cooling medium passage 62 and the outlet 64 of the cooling medium passage 62 determine the flow direction of the cooling medium in the direction of 180 degrees. In addition, an intermediate partition plate 56 is disposed in the center of each of the eight potholes 52 having the bottomed portion, and can be continuously circulated through the cooling medium passage 46 through the intermediate partition plate 56 by a single flow. ing.
[0016]
As shown in FIG. 4 (1), an intermediate partition plate 56 is inserted into the central portion of the pit hole 52 so as to be divided into two while being in contact with the wall surface of the pit hole 52 having the bottomed portion. The upper end portion of the middle partition plate 56 is attached to the lift member 70 in a T shape by welding or the like. This is to prevent both end portions of the lifting member 70 from being locked to the step portion of the outer mold 44 when the middle partition plate 56 is inserted into the blind hole 52, so that the locking member 70 does not shift downward. is there. Further, the length of the intermediate partition plate 56 is such that the cooling medium passage 62 is secured between the lower end portion of the intermediate partition plate 56 and the hole 52 having the bottomed portion, and the cooling medium can be circulated by a single flow. It has become a length. Further, the holding plate 72 has a reverse concave cooling medium passage 62 therein (FIG. 4 (2)), and a heat resistant packing (for example, gasket) 71 is provided on the upper and lower portions of the holding plate 72, respectively. A lid 74 is disposed so as to overlap.
[0017]
Next, the structure of the gas vent passage for smoothly discharging the gas (air) remaining in the cavity 10 to the outside of the mold when the molten aluminum 11 is filled in the cavity 10 will be described.
First, as shown in FIG. 6, in order to provide a gas vent passage 80 between the outer peripheral surface portion of the inner mold 42 and the inner peripheral surface portion of the outer mold 44, the outer peripheral portion of the inner mold 42 is partially engraved. In addition to a polygon (here, for example, an octagon), a gas vent passage 80 is not provided in the contact portion 92 between the outer peripheral surface portion of the inner mold 42 and the inner peripheral surface portion of the outer mold 44 that is not engraved. The configuration is as shown in FIG.
[0018]
Further, as shown in FIG. 7, the lower end portion of the gas vent passage 80 on the side facing the cavity 10 has a tapered space portion 90 in which the front cross section of the lower end outer peripheral surface portion 86 of the inner mold 42 is opened to the cavity 10 side. Is forming. This is because the gas remaining in the cavity 10 is smoothly discharged to the outside of the mold by filling the molten metal 11, and by forming the taper shape, the gas is discharged smoothly and simultaneously the molten metal 11 becomes a space. This is to prevent the gas from being solidified by the portion 90 and entering the gas vent passage 80.
[0019]
As shown in FIG. 5, reference numerals 80, 82 and 84 denote gas vent passages, and the gas remaining in the recavity 10 passes through the space 90 → the gas vent passage 80 → the gas vent passage 82 → the gas vent passage 84. Are discharged outside the mold. The gas vent passage 84 is a gap disposed between the extrusion pin 76 and the inner mold 42 and the upper backup mold. However, the lower partial region of the inner mold 42 on the cavity 10 side is connected to the extrusion pin 76. The inner mold 42 has a structure having a minute gap for sliding of the push pin 76.
[0020]
If a gas vent passage that allows the residual gas in the cavity 10 to be smoothly discharged is provided here, the molten metal 11 enters the gap between the extrusion pin 76 and the inner mold 42 and solidifies as it is. This is to prevent the push pin 76 from moving up and down and becoming unable to perform the original product pushing function. The gas vent passage 82 is a lateral gas vent passage connecting the upper end portion of the gas vent passage 80 and the lower end portion of the gas vent passage 84.
[0021]
Here, a method for forming an aluminum wheel using the mold for forming an aluminum wheel of the present invention will be described.
[0022]
During the series of casting / molding operations from injection and filling of the molten aluminum 11 into the cavity 10 and from the cooling of the mold to the removal of the cast product, the cooling medium introduced from the cooling medium inlet in the lower mold 1 (For example, water) is continuously circulated from the cooling medium outlet through the cooling medium direct passage 12 c from the beginning to the end, and a one-fold flow is generated in the hole 52 through the intermediate partition plate 56.
[0023]
First, when the mold is clamped and the injection plunger 7 is advanced by the injection cylinder while the injection sleeve 6 into which the molten aluminum 11 has been injected is joined to the lower backup mold 3, the molten aluminum 11 is pressed against the injection plunger 7. Then, it is cast and filled into the cavity 10. At this time, in the initial stage of casting and filling the molten aluminum into the cavity 10, most of the gas remaining in the cavity 10 is discharged from the gas vent passage 100, but the molten aluminum is completely filled in the rim portion 94. After that, the gas remaining in the cavity 10 is sequentially discharged as gas a flowing through the gas vent passage 80, gas b flowing through the gas vent passage 82, and gas c flowing through the gas vent passage 84 to the outside of the mold.
[0024]
When filling of the molten aluminum 11 into the cavity 10 is completed and most of the residual gas is discharged out of the mold, the molten metal 11 is inserted into the space portion 90 and subsequent degassing becomes impossible. When casting and filling of the molten metal 10 into the cavity 10 is completed, the upper and lower molds 1 and 4 are cooled and the molten metal 11 is solidified to cast a cast product made of an aluminum wheel material. The cast product is cut by the gate cutting pin 9 at the gate portion 8 of the lower mold 1 and taken out from the upper mold 4.
[0025]
When the filling of the molten aluminum 11 into the cavity 10 is completed, the mold is cooled and the molten metal 11 filled in the cavity 10 is solidified, but the tip of the copper rod 15 is cooled by the continuous circulation of the cooling medium, When the temperature gradient is generated in the copper rod 15 and the molten metal 11 is solidified by a high heat transfer coefficient, solidified soot and sensible heat are released. In particular, since the amount of heat released from the vicinity of the gate portion 8 and the cavity surface 13 having a cast shape is large, it is necessary to bring the cooling medium passage 12 closer to cool this heat. Mold cracking may occur due to poor adhesion and thermal stress.
[0026]
For this reason, the lower mold 1 is provided with a hole 16 directed toward the cavity surface 13, and a copper rod 15 having a circular cross section with a high thermal conductivity is attached thereto. The cross-sectional shape of the copper rod 15 is not limited to a circular shape, and a cross-sectional shape can be freely selected in addition to a quadrilateral, a hexagon, and an octagon.
[0027]
After the copper rod 15 is first installed in the hole 16, the copper rod 15 is heated when the molten metal is cast into the cavity 10, and the copper rod 15 contracts when the mold is cooled after filling with the molten metal. In this way, the copper rod 15 is attached to the inner surface of the hole 16 by an interference fit or attached to the surface of the copper rod 15 in the axial direction so that the copper rod 15 does not slide down toward the cooling medium passage 12 due to expansion / contraction by heating / cooling of the copper rod 15. Along with this, a screw is engraved and a screw similar to the copper rod 15 is engraved on the inner surface of the hole 16 so that the copper rod 15 can be screwed into the hole 16 and mounted.
[0028]
Thus, the copper rod 15 is prevented from sliding down to the cooling medium passage 12 side by the expansion / contraction of the copper rod 15 by heating / cooling. In addition, it is important to increase the processing accuracy of the copper rod 15 so that a gap between the copper rod 15 and the hole 16 is not generated as much as possible, and to attach the copper rod 15 to the hole 16. By doing so, the heat of the molten metal 11 reaching the hub portion 14 is transmitted to the copper rod 16, and the portion in contact with the cooling medium (for example, water) is cooled by being transmitted through the copper rod 15 having a high thermal conductivity. Cooling of the part 14 is promoted.
[0029]
In this way, by removing a large amount of heat stored in the hub portion 14, adhesion of the release agent to the design mold 2 and thermal stress can be reduced, and the life can be extended. Note that the distance at which the tip of the copper rod 15 protrudes causes a large flow resistance in the cooling medium flowing in the cooling medium passage 12 (generally, water is desirable, but it may be used for oil, liquid nitrogen, etc.). A position that does not exist is desirable.
[0030]
-On the other hand, if the length of the hole 52 formed in the upper mold 4 is made too long and too close to the cavity 10, the spoke part is overcooled and the heat is excessively removed, which is not a desirable state. On the contrary, if the length of the pit hole 52 is too short, a large amount of heat stored in the spoke part is not removed. For this reason, it is desirable to appropriately determine the length of the hole 52 according to the thickness of the spoke part of the aluminum wheel.
[0031]
【The invention's effect】
In the present invention, a cavity is provided between a lower mold having a gate part for casting a molten metal at the center and an upper mold provided facing the lower mold, and the upper mold is opposed to the gate part. A gate cutting pin disposed slidably up and down on the mold, an inner mold disposed adjacent to the periphery of the gate cutting pin, an outer mold disposed on the outer periphery of the inner mold, An upper backup mold that holds both the inner mold and the outer mold is provided, and gas remaining in the cavity is provided between the inner mold and the outer mold as the molten metal fills the cavity. A gas vent passage provided in the inner mold from the gas vent passage and a gas exhaust passage for discharging residual gas to the outside of the mold via the gas vent passage provided between the inner mold and the extrusion pin are provided. As a result, the molten metal is inserted into the gas vent passage. Since venting can be performed entirely on Iuchi, the yield of the casting is greatly improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.
FIG. 2 is a plan view of an upper mold cut along AA in FIG. 1;
FIG. 3 is a development view when a concave cooling medium passage is formed in the outer mold.
4 (1) is a longitudinal sectional view taken along line BB in FIG. 3, and FIG. 4 (2) is a longitudinal sectional view taken along line CC in FIG.
FIG. 5 is a route diagram of a gas vent passage showing a main part of the present invention.
6 is a transverse sectional view taken along line BB in FIG.
7 is a cross-sectional view taken along line DD of FIG.
8 is a cross-sectional view taken along line EE in FIG. 6. FIG.
FIG. 9 is a longitudinal sectional view showing a gas vent passage remaining in a conventional cavity.
10 is a plan view seen from FF in FIG. 9. FIG.
[Explanation of symbols]
1 Lower mold (fixed mold)
2 Design mold 3 Lower backup mold 4 Upper mold (movable mold)
5 Slide core 6 Injection sleeve 7 Injection plunger 8 Gate portion 9 Gate cutting pin 10 Cavity 11 Molten metal 12 Cooling medium passage 12c Cooling medium direct passage 13 Cavity surface 14 Hub portion 15 Copper rod 16 Hole 22 Recess 23 Lid 23 Lid 24 Tightening bolt 30 Runway 42 Inner mold 43 Engagement part 44 Outer mold 45 Step part 52 Bore hole 56 Middle partition plate 58 Upper backup mold 60 Jacket 62 Ring-shaped cooling medium passage 64 Cooling medium outlet 66 Cooling medium inlet 68 Partition plate 70 Locking member 71 Heat-resistant packing 72 Holding plate 74 Lid 76 Extrusion pin 78 Gap 80, 82, 84 Gas vent passage 86 Inner mold lower end outer peripheral surface portion 90 Space portion 92 Contact portion 94 Rim portion 100 Gas vent passage

Claims (1)

A cavity is provided between a lower mold having a gate part for casting molten metal at the center and an upper mold provided facing the lower mold, and the upper mold is opposed to the upper mold. A gate cutting pin slidably disposed; an inner mold disposed adjacent to the periphery of the gate cutting pin; The cavity includes an outer mold disposed on the outer periphery of the inner mold and an upper backup mold that holds both the inner mold and the outer mold, and the cavity is filled with the molten metal in the cavity. A gas vent passage provided in the inner mold from a gas vent passage provided between the inner mold and the outer mold, and a gas vent path provided between the inner mold and the extrusion pin. residual gas discharged to the upper die outside via Aluminum wheels mold, characterized in that a extraction passage.

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