JPH11285808A - Cast-in method - Google Patents

Abstract

(57) [Summary] [Object] To obtain a cast-in product such as a hydraulic circuit having a hollow interior without a gap between the cast-to-be-filled material and the cast-in material. [Structure] A flux is applied to an aluminum alloy member to be a to-be-stuffed material, and then set in molds 3 and 4, and a molten metal of a casting-use aluminum alloy to be a to-be-stuffed material is poured into the mold. As the material to be cast, an aluminum alloy pipe material 2 on which a heat insulating coating layer or an artificial oxide film is formed can be used. Further, in order to promote the fusion of the to-be-stuffed material and the to-be-stuffed material, the pipe material 1 provided with the thin flange 2 at a position near the surface of the as-stuffed product can be used as the to-be-stuffed material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for casting an aluminum alloy member with a casting aluminum alloy so that no gap is formed between the material to be cast and the cast material.

[0002]

2. Description of the Related Art Casting an aluminum alloy to be cast (hereinafter referred to as a to-be-cast material) with an aluminum alloy as-cast material is a very advantageous method in consideration of the later scrap processing. Particularly, an aluminum material manufactured by consuming a large amount of power is advantageous from the viewpoint of effective use of resources and energy. The melting temperature of the aluminum alloy surface is about 2
A dense and strong oxide film reaching 000 ° C. is formed. If such an aluminum alloy member having an oxide film is cast as it is, poor joining is likely to occur between the to-be-cast material and the as-cast material at the portion where the oxide film remains. Therefore,
When casting an aluminum alloy member, the oxide film on the surface of the aluminum alloy member to be cast as a material to be cast is removed and plated with Ni, Cr, Zn, or the like, which is effective for improving the bonding property. 5-293626, JP-A-64-
No. 75161). The high-melting-point metal coating layer of Ni, Cr or the like also prevents the heat of the molten cast-in material from being directly transmitted to the cast-in-fill material, and also has an effect of suppressing erosion and dissolution of the cast-in-fill material.

[0003]

[0005] Although the joining property between the cast material and the cast material is improved by plating with Ni, Cr, Zn or the like, the plated layer is formed by the cast material due to the difference in thermal expansion. May be peeled off. Therefore, when manufacturing a cast-in product having a hollow interior such as a hydraulic circuit, a gap that may cause oil leakage may occur near a place where a pipe used as a cast-receiving material comes out of the cast-in material. There is. In addition, a step of removing the oxide film from the surface of the material to be cast and performing a plating process is required, so that the manufacturing cost increases. Furthermore, when the recycled cast-in product is redissolved, Ni, Cr, Zn, and the like are mixed as impurities into the aluminum alloy, which adversely affects the properties of the aluminum alloy. Therefore, a process for removing and reducing impurities is required, and the recyclability is reduced.

[0004]

SUMMARY OF THE INVENTION The present invention has been devised to solve such a problem, and has an object to improve the affinity of a to-be-stuffed material with respect to a to-be-stuffed material, or to partially remove a to-be-stuffed material. Ni,
An object of the present invention is to provide a cast-in product in which plating of Cr, Zn, or the like is not required, and the cast-to-be-formed material is bonded to the cast-in material with good adhesion by a simple method. In order to achieve the object, the method of the present invention is to apply a flux to a part of an aluminum alloy member to be a to-be-stuffed material, set it in a mold, and melt the aluminum alloy for casting as a to-be-stuffed material. Is poured into a mold. An aluminum alloy pipe material on which a heat insulating coating layer or an oxide film is formed, except for a portion to be brought into close contact with the cast-in material, can be used as the to-be-stuffed material. In this case, it is preferable that the flux is applied to both ends of the pipe material and then set in a mold.
In addition, in order to promote the fusion of the cast-in-place material and the cast-in-place material, an aluminum alloy pipe material provided with a thin flange at a position near the surface of the cast-in product can be used as the cast-in place material. . In this case, it is preferable to apply a flux to the flange portion and form a heat-insulating coating layer or an oxide film on other portions.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a hydraulic circuit manufactured by the as-cast method, since oil leakage easily occurs at a place where a pipe material as a to-be-filled material comes out of the as-cast material, especially at this location, the as-stuffed material is used as a pipe. It is required to be bonded to the material with good adhesion. In the present invention, in order to improve the jointability at this point (indicated by A in FIG. 3), a flux is applied to the pipe material or a flange having a small heat capacity is formed so as to easily fuse with the cast-in material. The flux can be applied to other surfaces or the entire surface of the pipe material as long as the flux is applied to a necessary portion. The type of flux applied to the cast-in material is not particularly limited, and a fluoride, a chloride, a mixture of fluoride and chloride, or the like is used. Chloride-based flux has a higher melting point than fluoride-based flux, and is inferior in corrosiveness, spreadability, permeability and the like. In this regard, the use of a fluoride-based flux is preferred. It is desirable to use a flux having a particle size of 100 μm or less, more preferably 75 μm or less. However, if the particle size is 1 μm or less, it is too fine and handling becomes difficult.

The fluoride-based flux includes a eutectic composition of 45.8 wt% KF-54.2 wt% AlF _3, a substantially complexed complex mixture including a composition range close to this, and
KAlF ₄ , K ₂ AlF ₅ , K ₃ AlF ₆ , K ₂ SiA
Complexes such as l ₄ , LiF, and CaF are used. As the chloride-based flux, specifically, BaCl ₂ , NaC
It is preferable to use l, KCl, ZnCl ₂ or the like as a main component.
Typically, there is a flux of a ternary eutectic composition of BaCl ₂ -NaCl-KCl. The flux varies depending on the component, but is 2 to 350 g / m2 on the surface of the material to be cast.
It is applied in a ratio of ² . For example, after dissolving the flux powder in a solvent such as isopropylene to form a slurry,
Spray or brush is applied to the surface of the cast-in-place material.
The flux is also applied by immersing the cast material in the slurry flux. In addition, in order to form a strong and uniform flux layer, it is preferable to employ an electrostatic coating method in which the flux is applied as powder.

[0007] When the pipe material 1 with the flux applied to the necessary portion A is set in a mold and the molten metal of the stuffed material is poured, the flux is melted by the high heat of the stuffed material, and the oxide film on the surface of the pipe material 1 is melted. Dissolve. As a result, the surface state of the pipe material 1 becomes high, and the wettability to the cast-in material is improved. Therefore, a product having no gap between the material to be cast and the material to be cast can be obtained. The bondability between cast-in and cast-in materials is
It is also improved by forming a small heat capacity flange on the cast-in-place material. For example, as shown in FIG. 1, a thin flange 2 is formed on a part of a pipe material 1 used as a to-be-filled material. When the pipe material is set in a mold such that the flange 2 is located near the surface of the cast-in product and the molten metal of the cast-in material is poured, the flange 2 is softened and melted by the high heat immediately after pouring, and the cast-in material is formed. It becomes easier to fuse. Therefore, a gap is suppressed between the to-be-cast material and the to-be-cast material, and the pipe member 1 can be used safely as a part of the hydraulic circuit.

The thin flange 2 is easily formed by holding both sides of the pipe material 1 and applying a compressive force from the holding portion to a position where the flange 2 is to be attached. For example, when a pipe material made of 3003 aluminum alloy having a diameter of 6 mm is clamped and compressed, a flange 2 having a thickness of 2 mm and a diameter of 11 mm is formed to protrude from the peripheral surface of the pipe material 1. Also,
By using an appropriate mold at the time of molding, it is possible to mold the flange 2 (FIG. 2) having a shape whose tip is directed inside the cast-in product.

The flange 2 also facilitates positioning when setting the pipe material 1 in a mold. That is, prior to casting, the pipe material 1 to be cast is placed in the cavity 5 formed by the upper mold 3 and the lower mold 4 as shown in FIG. Contact
The pipe material 1 is secured at a predetermined position in the cavity 5.
Reference numeral 6 indicates a core. Further, in the flange 2 (FIG. 2) whose tip is directed toward the inside of the cast-in product, the molten metal of the cast-in material flows into a gap formed between the flange 2 and the inner surface of the lower mold 4. The fusion is further improved, and the pipe material 1 and the cast-in material are firmly integrated. By attaching the flange 2, the joining property between the pipe material 1 and the cast-in material is improved. However, if a flux is applied to the pipe material 1 in the flange forming portion, the joining property is further improved.

When pouring a molten cast-in material, the temperature of the pipe material 1 rises due to the heat of the molten metal. However, by forming an artificial oxide film such as a heat insulating coating layer or an anodic oxide film on the pipe material 1. Erosion and erosion of the pipe material 1 are suppressed.
As the heat insulating material, nitride, oxide, boride, carbonate, phosphate, graphite, calcium carbonate, feldspar, iron oxide, boric acid, mica, chalk, talc, kaolinite, titanium oxide, etc. are used. . The oxide film preferably has a thickness of 5 to 5.
An anodized film of 50 μm is preferred. The heat insulation coating layer or the oxide film prevents high heat immediately after pouring from being directly transmitted to the to-be-cast material, and the pipe material 1 is integrated with the to-be-stuffed material without being melted.

[0011]

EXAMPLE A 3000 type aluminum alloy pipe material having a diameter of 6 mm and a wall thickness of 3 mm was used as a material to be cast. The pipe material 1 is bent into a U-shape as shown in FIG. 1 and 10 pieces of a KAlF ₄ -K ₃ Al ₄ F ₆ type flux having a particle size of 50 μm are coated on the peripheral surface of 0 to 10 mm from both ends, at positions 10 mm from both ends. , 10 with a flange 2 having a thickness of 2 mm and a diameter of 11 mm, and 10 with an untreated or unprocessed one. A heat insulating material was applied to the peripheral surface of the pipe material 2 except for the flux application part A or the molding part of the flange 2. Each pipe material 1 was set in a mold as shown in FIG.
The pipe material 1 was stuffed by pouring a molten aluminum alloy to produce a hydraulic circuit. The pouring temperature was set so that the temperature of the molten aluminum alloy was 680 to 700 ° C. immediately before the entrance of the mold.

Each of the obtained cast-in products was subjected to an air leak test. In the air leak test, as shown in FIG. 4, an air supply pipe 8 having a diameter larger than that of the pipe material 2 is brought into contact with a surface portion of the cast-in product 7 in which one end of the pipe material 2 is opened. Was plugged with plug 9. Then, compressed air 10 was sent through the air supply pipe 8 to check for air leakage. If there is an air leak in this test, the pipe material 2 and the cast-in material 1
1 indicates that a gap has occurred. As can be seen from the test results in Table 1, when a pipe material 1 coated with a flux or a pipe material 1 with a flange 2 is used as a to-be-stuffed material, all of the obtained hydraulic circuits are cast-in products without air leakage. Met. On the other hand, in the case where the pipe material 1 was cast without flux application or flange forming, air leakage was detected in 8 out of 10 cast-in products. As is clear from this comparison, it was confirmed that the joining property between the pipe material 1 and the stuffed material 11 was improved by flux application or flange forming, and a stuffed product 7 having no gap between them was obtained.

[0013]

[0014]

As described above, according to the present invention, when an aluminum alloy member is cast with an aluminum alloy for casting, a flux is applied to the peripheral surface of the aluminum alloy member which is close to the surface of the cast-in product. Alternatively, by attaching a flange having a small heat capacity, the joining property with the cast-in material is improved, and a cast-in product having no gap between the cast-in material and the cast-in material is obtained. In addition, when the pipe material is used as a to-be-filled material, since the erosion when the inlay is formed by applying a heat insulating material or forming an oxide film is suppressed, a to-mold product having a hollow portion such as a hydraulic circuit can be easily manufactured. Manufactured.

[Brief description of the drawings]

Fig. 1 Flanged pipe material used as cast-in-place material

Fig. 2 Pipe material with improved shape and flange

FIG. 3 is a view for explaining that a pipe material set in a mold is cast.

FIG. 4 is an explanatory view of an air leak test.

[Explanation of symbols]

1: pipe material, 2: flange, 3: upper mold, 4: lower mold,
5: cavity, 6: core, 7: cast-in product, 8: air supply pipe, 9: plug, 10: compressed air, 11: cast-in material A: surface portion of pipe material to which flux is applied

Continued on the front page (72) Inventor Yasuhiko Hamano 43-3 Harumicho, Tomakomai City, Hokkaido Nippon Light Metal Co., Ltd. Tomakomai Factory

Claims (6)

[Claims] 1. A stuffing machine characterized in that a flux is applied to an aluminum alloy member to be a stuffing material, then set in a mold, and a molten metal of a casting aluminum alloy to be a stuffing material is poured into the mold. Method. 2. An aluminum alloy pipe material on which a heat insulating coating layer or an oxide film is formed is used as a to-be-stuffed material, a flux is applied to a part of the pipe material, and then set in a mold. Casting method characterized by pouring a molten aluminum alloy for casting into a mold. 3. An aluminum alloy pipe material provided with a thin flange at a position near the surface of the cast-in product is set in a mold as a material to be cast, and a molten aluminum alloy for casting to be a cast-in material is cast into a mold. Casting method characterized by pouring into a hole. 4. The method according to claim 3, wherein an aluminum alloy pipe material on which a heat insulating coating layer or an artificial oxide film is formed except for a flange portion is used. 5. The method according to claim 3, wherein the flux is applied to the aluminum alloy pipe material and then set in a mold. 6. A hydraulic circuit manufactured by the method according to claim 1.