JP2005074461A - Molding manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding manufacturing method capable of manufacturing a molding of excellent material characteristic and strength at low cost in relatively simple processes. <P>SOLUTION: Molten metal 11a is poured into molds 1 and 2 and cooled while primary pressure P1 is being applied thereto to mold a semi-molding 11b in a semi-solidified or solidified state. At least part of the semi-molding 11b is plastically deformed to manufacture a molding 11 while secondary pressure P2 larger than the primary pressure P1 is being applied to the molds 1 and 2 without taking out the semi-molding 11b from the molds 1 and 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a manufacturing method for manufacturing various molded articles using a non-ferrous metal such as an aluminum alloy or a magnesium alloy.

  As a method of manufacturing various molded products using such non-ferrous metals, a “casting method” using a mold is generally used, and the molten metal injected into the mold is solidified by applying pressure to form a cast structure. There is also a known casting method for manufacturing products, and there is also known a “die forging method” in which a solid material is plastically deformed to produce a molded product with a forged structure (casting and forging are too common) And no patent literature suitable for citation).

However, it is known that internal defects such as segregation, shrinkage, porosity, etc. are known to occur in molded products by conventional casting methods. Even casting methods that solidify by applying pressure to the molten metal apply too high pressure. Since this is not possible, internal defects may occur and there are problems in terms of material properties and strength.
In that respect, according to the die forging method, it is possible to obtain a molded product that is satisfactory in terms of material properties and strength without occurrence of internal defects. However, a solid material corresponds to a desired molded product in advance. It is necessary to form in a shape, and in some cases, it is necessary to gradually forge to a molded product using a plurality of dies, which has the disadvantage that the manufacturing process becomes complicated and the manufacturing cost increases. .

  The present invention pays attention to such conventional problems, and its purpose is molding that can produce a molded product that is inexpensive in a relatively simple process and that is excellent in terms of material properties and strength. It is in providing the manufacturing method of goods.

  The first characteristic configuration of the present invention is that a mold into which a molten metal is injected is cooled while applying a primary pressure, and a semi-solid product or a semi-molded product in a solid state is cast, and the semi-molded product is removed from the mold. The molded product is manufactured by plastically deforming at least a part of the semi-molded product while applying a secondary pressure larger than the primary pressure to the mold without taking it out.

According to the first characteristic configuration of the present invention, the semi-molded product in a semi-solid state or a solid state is cast by cooling the mold into which the molten metal has been injected while applying a primary pressurizing force. A semi-molded product having a shape close to that of the product and having no internal defects can be obtained.
Then, without removing the semi-molded product from the mold used for casting, a secondary pressure greater than the primary pressure is applied to the mold to plastically deform at least a part of the semi-molded product. Manufacturing.
As a result, while simplifying the manufacturing process and reducing the cost, it is possible to manufacture a molded product excellent in both material characteristics and strength at a low cost.

  The second characteristic configuration of the present invention resides in that a molded product having a cast structure is produced by plastically deforming only a part of the semi-molded product by applying the secondary pressure.

According to the second characteristic configuration of the present invention, a molded product having a cast structure is manufactured by plastically deforming only a part of the semi-molded product by applying a secondary pressurizing force. In addition to being able to produce a product, it is possible to produce a cast product according to the desired dimensions at a low cost.
In other words, when a cast product is manufactured using a mold, an amount of molten metal corresponding to the volume of the cast product may be injected into the mold. It is very difficult. Therefore, in the past, a slightly larger amount of molten metal was poured and casted, and then finished into a product with a desired dimension by machining, and finishing work by machining was indispensable.

However, according to the second characteristic configuration of the present invention, only a part of the half-molded product is plastically deformed by the secondary pressurizing force. Therefore, by forming the surplus portion by the plastic deformation, a cast product having a desired size is obtained. Can be manufactured.
Specifically, a large amount of molten metal is poured into a mold to cast a semi-molded product, and then a secondary pressurizing force is applied to form a cast product of a desired size, while the surplus portion is plastically deformed. It escapes into the mold and forms a surplus part. As a result, the cast product has the desired dimensions, and after that, it is only necessary to cut off the surplus part, eliminating the need for machining work that was indispensable in the past, and producing a cast product with high dimensional accuracy at low cost. It can be done.

  A third characteristic configuration of the present invention resides in that a molded product having a forged structure is produced by plastically deforming the semi-molded product by applying the secondary pressure.

  According to the third characteristic configuration of the present invention, since the semi-molded product is plastically deformed by applying a secondary pressurizing force to produce a molded product having a forged structure, Due to the plastic flow due to the effect, it becomes a homogeneous and fine forging structure, and forging with high dimensional accuracy, which is the final product, can be manufactured at low cost by performing casting and forging in a series of operations using the same mold. .

  A fourth characteristic configuration of the present invention is that the molten metal is a molten aluminum alloy.

  According to the fourth characteristic configuration of the present invention, since the molten metal to be injected into the mold is a molten aluminum alloy, for example, a cast product and a forged product made of a heat resistant aluminum alloy having excellent heat resistance, and corrosion resistance. Cast products and forged products having various characteristics such as those made of aluminum alloy or high-strength aluminum alloy can be manufactured.

  A fifth characteristic configuration of the present invention is that the primary pressure is 50 to 250 MPa, and the secondary pressure is 100 to 1000 MPa.

  According to the fifth characteristic configuration of the present invention, when using a molten aluminum alloy, the primary pressure is 50 to 250 MPa and the secondary pressure is 100 to 1000 MPa. It is possible to reliably produce castings and forgings made of aluminum alloy having characteristics and strength.

Embodiments of a method for producing a molded article according to the present invention will be described with reference to the drawings.
This manufacturing method is a method for manufacturing various molded products such as cast molded products and forged molded products using non-ferrous metals such as aluminum alloys and magnesium alloys, and particularly requires high strength and dimensional accuracy. It is suitable for manufacturing a molded product, and a manufacturing method of a cast product in the first embodiment and a manufacturing method of a forging product in the second embodiment will be described.

(First embodiment)
As shown in FIG. 1, a cast product is manufactured by using a die composed of a lower die 1 and an upper die 2, and the lower die 1 is a bottom plate 3 and a cylinder installed on the bottom plate 3. Side mold 4 and a bottom mold 5 installed in the side mold 4 so as to be movable in the vertical direction. The bottom mold 5 is moved up and down by a piston rod 6 interlocked with a cylinder (not shown). It is configured to be possible.
In the vicinity of the upper surface of the bottom mold 5, a cooling path 7 for cooling water is provided, and a water inlet path 7 a and a water outlet path 7 b communicating with the cooling path 7 are provided across the bottom plate 3 and the bottom mold 5. The bottom mold 5 is cooled by allowing cooling water to flow therethrough.
Furthermore, if necessary, the side mold 4 can also be provided with a cooling path, and although not shown, the bottom mold 5 and the side mold 4 are provided with heating means for preheating.

The upper mold 2 includes a first upper mold 8 that can be inserted into the side mold 4 of the lower mold 1, a second upper mold 9 that is configured to be relatively movable in the vertical direction, and the like. 9 are respectively linked to a pressurizing device (not shown).
A cooling path 10 for cooling water is also provided near the lower surface of the first upper mold 8, and an inlet path 10 a and an outlet path 10 b communicating with the cooling path 10 are provided in the first upper mold 8, and the cooling path The first upper mold 8 is cooled by passing cooling water through 10. Although not shown, the first upper mold 8 is also provided with heating means for preheating.

Next, a method for producing a cast product using the molds 1 and 2 will be described.
First, the upper and lower molds 1 and 2 are preheated by a heating means not shown, and a non-ferrous metal melt 11a such as an aluminum alloy or a magnesium alloy is injected into the lower mold 1 as shown in FIG. To do.
Then, as shown in FIG. 1B, the primary pressure P1 is applied to the first and second upper molds 8 and 9, respectively, and the cooling paths 7 and 10 of both molds 1 and 2 are applied. While the molds 1 and 2 are cooled by flowing cooling water, the molds 1 and 2 are used to cast a semi-solid or solidified semi-molded product 11b.

After that, without removing the semi-molded product 11b from the molds 1 and 2, the first upper mold 8 is applied to the second upper mold 9 while the primary pressure P1 is applied as shown in FIG. Cooling is performed while applying a secondary pressure P2 larger than the primary pressure P1.
The semi-molded product 11b in the semi-solid state or solidified state is pressurized by the action of the secondary pressure P2, and a part of the semi-molded product 11b is plastically deformed by the relative movement of the second upper mold 9 upward. The meat part 11c is formed.
Thereafter, as shown in FIG. 1 (d), the upper mold 2 and the bottom mold 5 are raised to take out the cast product 11 integrally having the surplus part 11c, and the surplus part 11c is cut off and cast. The molded article 11 having a structure is obtained.

Next, the manufacturing method of this cast product will be described more specifically with reference to the time chart of FIG. 3 and the conceptual diagram of FIG.
For example, in the case of producing a cast molded product 11 made of a heat-resistant and wear-resistant aluminum alloy (4032 alloy), the molds 1 and 2 are preheated to 150 to 300 ° C. (423 to 573 K), As shown in FIG. 4, a molten aluminum alloy 11a heated to about 750 ° C. (1023 K) is injected and pressurized by applying a pressure of about 175 MPa as the primary pressure P1.
By this primary pressurization, the molten metal 11a that has been in a liquid state changes from a semi-solid state to a solid state to become a semi-molded product 11b, and the surface temperature of the semi-molded product 11b is about 400 ° C. (673K). When the temperature reaches about 500 ° C. (773 K), the cast molding 11 is obtained by applying a secondary pressure P2 of about 460 MPa.

  Next, the second embodiment will be described. However, in order to avoid redundant description, the configurations described in the first embodiment and the configurations having the same functions are denoted by the same reference numerals and the description thereof is omitted, and the first embodiment is mainly described. A configuration different from the example will be described.

(Second embodiment)
As shown in FIG. 2, a forged product is manufactured by using a mold composed of a lower mold 1 and an upper mold 2, and the lower mold 1 includes a cylindrical side mold 4 and a side mold 4. The side mold 4 includes a first bottom mold 5a installed in a vertically movable manner, a second bottom mold 5b penetrating through the first bottom mold 5a and relatively movable in the vertical direction. The second bottom mold 5b is maintained in a fixed state, and the first bottom mold 5a is interlocked with a pressurizing device (not shown).
As in the first embodiment, the upper mold 2 includes a first upper mold 8 that can be inserted into the side mold 4 of the lower mold 1 and a second upper mold 9 that is configured to be relatively movable in the vertical direction. The upper molds 8 and 9 are respectively interlocked with a pressurizing device (not shown).

Although not shown, the cooling path 7 as shown in the first embodiment is provided in the vicinity of the top surfaces of the bottom molds 5a and 5b, and the bottom molds 5a and 5b and the side mold 4 have A heating means for preheating is provided.
Similarly, the cooling path 10 as shown in the first embodiment is also provided near the lower surface of the first upper mold 8, and heating means for preheating is also provided.

Next, a method for producing a forged product using the molds 1 and 2 will be described.
As in the first embodiment, the upper and lower molds 1 and 2 are preheated by a heating means (not shown), and as shown in FIG. 2 (a), a non-ferrous metal melt 11a such as an aluminum alloy or a magnesium alloy is used as a lower metal. Inject into mold 1.
Then, as shown in FIG. 2B, the mold 1 is applied while applying the primary pressure P1 to the first and second upper molds 8 and 9 and cooling both molds 1 and 2, respectively. , 2 is used to cast a semi-solid or solid-state semi-molded product 11b.
In addition, at the time of casting of this semi-molded product 11b, the same back pressure P3 as the primary pressure P1 is applied to the first bottom mold 5a.

Then, without removing the semi-molded product 11b from the molds 1 and 2, as shown in FIG. 2C, the first and second upper molds 8 and 9 are subjected to a secondary pressure larger than the primary pressure P1. Cooling while applying the pressure P2, and, as shown in FIG. 2 (d), with the secondary pressure P2 applied to the first upper mold 8, for example, the pressure applied to the second upper mold 9 is 1 The pressure is reduced to about the next applied pressure P1.
When the secondary pressure P2 is applied, the first bottom mold 5a is initially applied with a back pressure P3 smaller than the secondary pressure P2 (for example, the same back pressure as the primary pressure P1). When the first bottom mold 5a is lowered to the position shown in FIG. 2C, the same back pressure P3 as the secondary pressure P2 is applied.

The semi-molded product 11b in the semi-solid state or solidified state is plastically deformed and forged by the action of the secondary pressure P2, and the material characteristics are greatly improved by the deformation caused by the plastic flow. The surplus portion 11c is formed by relative movement.
Thereafter, although not shown, the upper mold 2 and the first bottom mold 5a are raised to take out the forged molded product 11 integrally having the surplus portion 11c, and the surplus portion 11c is excised to form a forged structure. The product 11 is obtained.

Also in this forged product manufacturing method, for example, in the case of manufacturing a forged molded product 11 made of a heat-resistant and wear-resistant aluminum alloy (4032-based alloy), the molds 1 and 2 are set to 150 to 300 ° C. (423 to 423). 573K), a molten aluminum alloy 11a heated to about 750 ° C. (1023K) is injected, and a pressure of about 175 MPa is applied as the primary pressure P1 to obtain a semi-molded product 11b. .
Then, when the surface temperature of the semi-molded product 11b is about 400 ° C. (673K) and the internal temperature is about 500 ° C. (773K), a secondary pressure P2 of about 460 MPa is applied to obtain the forged product 11. It is.

However, the above-described temperatures and pressures, that is, the numerical values shown in the first and second embodiments are merely examples, and in actual implementation, depending on the type of alloy used, the shape of the molded article 11, and the like. Therefore, the optimum temperature and pressure are selected.
When various experiments were conducted on this point, as shown on the right side of FIG. 4, the primary pressure P1 was within a range of 50 to 250 MPa, and the secondary pressure P2 was 100 MPa or more. It was found that it is preferable to select a pressure greater than the primary pressure P1 within the range of 100 to 1000 MPa.
The temperatures of the molten metal 11a and the semi-molded product 11b at the time of the primary pressurization and the secondary pressurization are 350 to 730 ° C. (623 to 1003 K) at the time of the primary pressurization, as shown on the left side of FIG. It was about 200-550 degreeC (473-823K) at the time of pressurization.

[Another embodiment]
In the previous embodiment, the example of manufacturing the molded article 11 made of an aluminum alloy has been described. However, in addition to aluminum and aluminum alloy, various non-ferrous metal molded articles such as magnesium and magnesium alloy are manufactured. Can be applied.
The molded product 11 to be manufactured is not particularly limited. Therefore, the mold to be used is not limited to the molds 1 and 2 shown in the previous embodiment, and has various shapes and configurations. A mold can be used.

Conceptual diagram showing the manufacturing process of castings Conceptual diagram showing the manufacturing process of forged products Manufacturing process time chart Manufacturing process state conceptual diagram

Explanation of symbols

1, 2 Mold 11 Molded product 11a Molten metal 11b Semi-molded product P1 Primary pressure P2 Secondary pressure

Claims (5)

  The mold into which the molten metal has been injected is cooled while applying a primary pressure to cast a semi-solid or solid-state semi-molded product, and the semi-molded product is removed from the mold without removing the 1 A method for producing a molded product, wherein a molded product is produced by plastically deforming at least a part of the semi-molded product while applying a secondary pressure greater than the secondary pressure.   The method for producing a molded article according to claim 1, wherein a molded article having a cast structure is produced by plastically deforming only a part of the semi-molded article by applying the secondary pressure.   The method for producing a molded product according to claim 1, wherein the molded product having a forged structure is produced by plastically deforming the semi-molded product by applying the secondary pressure.   The method for producing a molded article according to claim 2 or 3, wherein the molten metal is a molten aluminum alloy.   The method for producing a molded product according to claim 4, wherein the primary pressure is 50 to 250 MPa, and the secondary pressure is 100 to 1000 MPa.

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