JPH0839227A - Production of product having hollow passage - Google Patents

Abstract

PURPOSE:To surely produce a product with high precision even though a hollow passage formed in the product is long or has a complicated route of small diameter. CONSTITUTION:The product having the hollow passage of a small diameter in the inner part of a body is produced by the following process. Partial pieces of the product body including a part of the hollow passage are manufactured. Cylindrical pieces 2d, 2e each having a hollow part of the diameter the same as the hollow passage are arranged each at a position to be formed with the remaining hollow passage part of the product body continuously to the hollow passages 2a, 2b, 2c formed in these partial pieces, and these partial pieces and the cylindrical pieces are arranged in a mold. Molten metal is poured into the mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method suitable for manufacturing a product having a hollow passage having a small diameter, in particular, a hollow passage curved in a curve.

[0002]

2. Description of the Related Art When manufacturing die cast moldings and plastic moldings, a manifold (distributor) is used to distribute and feed a viscous liquid molding material to each mold. In this manifold, a hollow passage having a complicated path having branch points and corners is formed inside the main body, and the molding material can be pressure-fed through this hollow passage.

[0003] A technique for producing a product having a hollow passage having a complicated passage such as this manifold by casting is not well known. Therefore, the present applicants have previously developed a method for easily and highly accurately manufacturing a product having a hollow path with a complicated path by casting, and applied for a patent (Japanese Patent Application No. 5-320125). , Japanese Patent Application No. 6-24061
issue). The method disclosed in these patent applications is to form a core having a shape corresponding to the hollow path of the product from a ceramic material,
This core is placed in a mold to cast a product body, and then the ceramic core is dissolved and removed by a solvent.

[0004]

However, in the method using the ceramic core, when the hollow passage formed in the product is long or the passage has a complicated small diameter, the casting is performed. There is a problem that the ceramic core cannot withstand the pressure received from the molten metal.
In this respect, according to the method disclosed in Japanese Patent Application No. 6-24061,
Although the reinforcing material is inserted inside the core to increase the strength, the strength is still limited. The present invention solves such a problem, and has a hollow passage that can be reliably and accurately manufactured even if the hollow passage formed in the product is long or has a complicated small diameter. It aims at providing the manufacturing method of.

[0005]

In order to achieve the above object, the present invention is a method for manufacturing a product having a hollow passage inside a main body, which is configured to include the following steps. First step of forming a partial piece of the main body including a part of the hollow passage In the remaining hollow passage portion of the main body to be continued from the hollow passage formed in the partial piece, a tubular piece having substantially the same inner diameter as the hollow passage portion, The second step of arranging the hollow part in a state where it communicates with the hollow path in which the partial piece should be continuous, and arranging these partial piece and tubular piece in the mold forming the remaining part of the main body in the mold Third step of pouring the molten metal In the second step, for example, the partial piece and the tubular piece are connected by brazing, and then the partial piece and the tubular piece are arranged in the mold. be able to.

[0006]

According to the present invention, each piece of the product body including a part of the hollow passage is individually formed. Therefore, no matter how long the hollow path of the entire product is or how complicated it is, the hollow path can be divided into parts and formed. You can

Then, a tubular piece is arranged in a hollow passage portion of the main body to be continued from a hollow passage formed in a partial piece which is a part of the product body, and the portion piece and the tubular piece are cast and wrapped. The product body can be manufactured by casting the remaining body portion. Here, the hollow portion of the tubular piece corresponds to a part of the hollow passage formed in the product body. The tubular piece uses a metal material having a melting point higher than that of the metal melt forming a part of the product body or the same metal material as the metal melt. Further, it is preferable that the tubular piece has a short and simple shape capable of sufficiently withstanding the pressure received from the molten metal.

In the second step, when the partial piece and the tubular piece are connected by brazing, the molten brazing material may leak from the connecting end surface to the hollow road side. If this leakage of the brazing material is slight, it can be easily removed by polishing the inner surface, but if it becomes a protrusion that rises to 1 mm or more, it is not easy to remove it by polishing the inner surface. Therefore, at the time of this brazing, it is preferable to dispose a ceramic leakproof member at least in a communicating portion between the hollow passage formed in the partial piece and the hollow passage of the tubular piece. With this configuration, the leak-preventing member arranged in the hollow passage suppresses the brazing filler metal from leaking out, and a hollow passage having a smooth inner peripheral surface can be formed.

Since the ceramic leakproof member can be dissolved and removed by using a solution such as caustic soda after the partial piece and the tubular piece are connected (may be after casting), the leakproof member can be treated as foreign matter in the hollow passage. It does not remain. As a ceramic material that can be used for such a leak prevention member, there is, for example, SiO ₂ ceramics. The SiO ₂ ceramics can be dissolved by caustic soda (solvent). In addition, if unevenness is formed on the surface of the piece and casting is performed by pouring a molten metal around it, the unevenness of the piece meshes with the metal lump that has solidified around it, and It is possible to prevent rattling and falling out.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a vertical sectional view of a product manufactured by the method according to this embodiment. In this embodiment, as in a manifold, a product having a block-shaped body and a hollow passage having curved corners and branch points is manufactured. The product body 1 shown in the figure is formed of a plurality of product parts A, B, C, D, E and F. Of these, three product parts A, B, and C are part pieces 1 and 1, respectively.
Separately manufactured as 1 and 12 (see FIG. 8).

2 to 4 show these partial pieces 10, 1.
1 shows an example of a method for manufacturing 1, 12. This method utilizes the “method for producing a product having a hollow passage” disclosed by the present applicant in Japanese Patent Application No. 5-320125. That is, first, the ceramic member 3 is used to manufacture the core 4 having a shape corresponding to the hollow passage 2a formed in the partial piece 10 (see FIG. 2). Here, it is preferable to insert in the core 4 an intermediate material 5 formed of a material that can be removed by an operation such as heating or can be melted and removed. Suitable materials for this intermediate material 5 include
For example, there are cord materials made by twisting cotton threads, brazing materials, urethane resin materials, low melting point and soft metal materials such as aluminum alloys and lead alloys. The core 4 shown in FIG. 2 is formed of a cord material made by twisting cotton yarn.

Next, the mold 6 for forming the partial piece 10 is formed.
Is prepared (see FIG. 3), the core 4 is placed in the mold 6, and then the metal melt 7 (the metal material forming the product body 1) is poured. At this time, the intermediate material 5 in the core 4 is burned by the heat of the molten metal 7, and a cavity 8 is formed in the core 4 as shown in FIG. Inside the partial piece 10 manufactured in this way, the core 4 made of a ceramic member is provided in the hollow passage 2a.
Remains. Therefore, the core 4 is dissolved and removed by a solvent 9 such as caustic soda to form the hollow passage 2a inside the partial piece 10 (see FIG. 4). The pieces 11, 12 can likewise be produced separately.

When the hollow passage in the segment has a simple shape, various processes conventionally known without using the method disclosed in Japanese Patent Application No. 5-320125. It can also be produced by the method. 9 and 10
Shows a method of manufacturing a partial piece using a split mold.
That is, the divided piece 10 having a shape obtained by dividing the partial piece 10 into two pieces.
1, 102 are cast using split molds. These divided pieces 101 and 102 have a shape obtained by vertically cutting the hollow passage 2a portion of the partial piece 10. Since the hollow passage 2a portion is exposed on the surface, it can be manufactured by a general casting method. it can. Therefore, according to this method, as described above, it is not necessary to dispose the core 4 made of ceramics and to melt the core 4 after casting. Then, after the divided pieces 101 and 102 are manufactured, they can be joined by brazing or the like to form the partial piece 10.

After the partial pieces 10, 11 and 12 are separately manufactured, the hollow passages 2a, 2b and 2c formed in the partial pieces 10, 11 and 12 and the remaining hollow passages 2d,
The tubular pieces 13 and 14 are arranged in the 2e portion (see FIG. 5).
The inner diameters of the hollow portions of the tubular pieces 13 and 14 are approximately the same as the hollow passages 2d and 2e. Also, the tubular piece 1
The lengths of 3 and 14 are set to the dimensions of the length of the hollow passages 2d and 2e, respectively, plus the connection allowance. Tubular piece 1
3 and 14 are the same materials as the partial pieces 10, 11 and 12, or a molten metal 18 used for casting the product part D described later.
It is formed of a metal material having a melting point equal to or higher than the melting point of.

On the other hand, the anchor part 10 is provided in the connection opening of the hollow passages 2a, 2b, 2c in the partial pieces 10, 11, 12.
a, 10b, 11a, 12a are formed, and the end portions of the tubular pieces 13, 14 are inserted thereinto, and the pieces 10 to 14 are formed.
Are connected to each other. The inlay parts 10a, 10
b, 11a, 12a can be formed by machining after the casting, in addition to forming the parts 10, 11, 12 during casting.

FIG. 6 is an enlarged sectional view showing this connecting portion (A portion in FIG. 5). The brazing material 11 is firmly fixed between the brazing part 11a and the end portion 13a of the tubular piece 13, and the interposition of the brazing material 15 eliminates a gap. This prevents the molten metal 18 from flowing into the hollow passage 2 in the casting of the product portion D described later.

Here, the brazing filler metal 15 is melted by heating and then cooled, so that the brazing part 11a and the cylindrical piece 1 are melted.
The end portion 13a of No. 3 is fixed without a gap. When the brazing filler metal is melted, the liquefied brazing filler metal 15 may leak from the connecting portion and may be solidified in the hollow passage 2 in a raised state.
If a large amount of this brazing filler metal 15 leaks out, it will take time to polish the inner surface in the finishing process. Therefore, in this embodiment, as shown in FIG. 7, the partial piece 11 and the tubular piece 1 are arranged.
A leak-preventing member 16 is arranged in the entire width of the hollow passage 2 located at the connection portion with the brazing material 3 so that the brazing material 15 can be melted. With this configuration, the leak preventing member 16 can prevent the melted brazing material 15 from leaking to the hollow passage 2 side.

The leak prevention member 16 is made of a ceramic material (eg, SiO ₂ ceramics) that can be dissolved by a predetermined solvent (eg, caustic soda). After brazing the connecting portion between the partial piece 11 and the tubular piece 13, the solvent is poured into the hollow passage 2 to dissolve and remove the leak prevention member 16.
The removal and removal of the leak preventive member 16 may be performed at any time after brazing. However, in the casting of the product portion D, which will be described later, there is a possibility that a part of the brazing material 15 will be softened again by the heat received from the molten metal 18, so that it is preferable to perform the casting after the casting of the product portion D.

The connecting portions of each piece other than the connecting portion between the partial piece 11 and the tubular piece 13 are also connected in the same manner as described above. The partial pieces 10, 11 and 12 and the tubular pieces 13 and 14 connected to each other in this manner are arranged in the mold 17. Here, the mold 17 is the remaining part of the product body 1 (product part D in FIG. 1).
It has a size and shape that can be formed. Part pieces 10,1
1, 12 are product parts A in FIG.
It is placed at a position corresponding to B and C. At this time, the tubular piece 1
Hollow portions 3 and 14 are hollow passages 2d and 2e shown in FIG.
Is arranged at a position corresponding to.

Subsequently, a molten metal 18 (a metallic material forming the product body 1) is poured into the mold 17 (see FIG. 8).
Then, after the molten metal 18 is solidified, it is taken out from the mold 17 and a finishing step such as polishing the inner surface of the hollow passage 2 is performed to complete the product body 1.

By appropriately changing the length of the tubular piece, it is possible to easily manufacture a plurality of types of products that differ only in the opening position of the hollow passage. For example, the opening position of the material supply port in the manifold varies depending on the size of the mold connected to it. Therefore, only the product parts A, B, and C shown in FIG.
By adjusting the opening positions of the hollow passages 2b and 2c (corresponding to the opening positions of the material supply ports) according to the length of 4, various manifolds having different opening positions of the material supply ports can be easily manufactured at low equipment cost. It can be manufactured.

If a concave portion or a convex portion is formed on the surface of each of the partial pieces 10, 11 and 12, when the casting shown in FIG.
Since the molten metal 18 enters into the concave portions and the convex portions, it is possible to manufacture a product in which there is no risk of rattling or falling out of the respective segment pieces 10, 11, 12. Even if fine irregularities are formed by forming the surfaces of the respective segment pieces 10, 11, 12 to be rough, the same effect can be obtained.

The present invention is not limited to the above-described embodiments, and it goes without saying that the products that can be manufactured are not limited to those of the form shown in FIG. The present invention
For example, the effect is particularly exerted in the production of a product having a curved corner or a hollow passage having a branch point, but the invention can be used in the production of a product having a straight hollow passage as required. Further, if the tubular piece is formed in a curved shape, a hollow path curved by the hollow portion of the tubular piece can be formed in the product.

[0024]

As described above, according to the present invention,
Even if the hollow path formed in the product is long or has a complicated small diameter, the product can be manufactured reliably and highly accurately.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a product manufactured according to an embodiment of the present invention.

FIG. 2 is a view showing a method of manufacturing a partial piece according to the embodiment of the present invention, which is a vertical sectional view showing a first step of the method.

FIG. 3 is a vertical sectional view showing a second step in the same manner.

FIG. 4 is a vertical sectional view showing a third step as well.

FIG. 5 is a vertical cross-sectional view showing a step of connecting a partial piece and a tubular piece according to the embodiment of the present invention.

6 is a cross-sectional view showing an enlarged part A of FIG.

FIG. 7 is a vertical cross-sectional view showing a brazing filler metal leakage preventing means in the connecting step shown in FIG.

FIG. 8 is a vertical sectional view showing a casting process in the example of the present invention.

FIG. 9 is a front view showing another method of manufacturing the segment according to the embodiment of the present invention.

FIG. 10 is a side view of the same.

[Explanation of symbols]

 1: Product main body 2: Hollow passage 10, 11, 12: Partial piece 13, 14: Cylindrical piece 15: Brazing material 16: Leak prevention member 17: Mold 18: Molten metal

Claims (4)

[Claims] 1. A method of manufacturing a product having a hollow passage inside a main body, comprising: forming a partial piece of the main body including a part of the hollow passage; and continuing from the hollow passage formed in the partial piece. In the remaining hollow passage portion of the main body, a tubular piece having an inner diameter substantially the same as that of the hollow passage portion is arranged in a state where the hollow portion communicates with the hollow passage to which the portion piece should be continuous. A method for manufacturing a product having a hollow passage, comprising: placing a tubular piece in a mold forming the remaining portion of the main body; and pouring a molten metal into the mold. . 2. The hollow passage according to claim 1, wherein the partial piece and the tubular piece are connected by brazing, and then the partial piece and the tubular piece are arranged in the mold. The manufacturing method of the product which has. 3. A brazing material between the partial piece and the tubular piece, with a ceramic leakproof member arranged at least in a communicating portion between the hollow path formed in the partial piece and the hollow path of the tubular piece. The method for manufacturing a product having a hollow passage according to claim 2, wherein the connection is made by attachment. 4. The method for producing a product having a hollow passage according to claim 1, wherein unevenness is formed on a surface of the partial piece.