JPH07323367A - Method of manufacturing product having hollow passage - Google Patents

Abstract

(57) [Summary] [Purpose] The hollow passage formed in the product is long,
Even if the route has a complicated small diameter, it is possible to manufacture the product reliably and with high accuracy. [Structure] A product having a hollow passage with a small diameter inside the main body is manufactured in the following process. A step of forming part pieces 10, 11, 12 of the product body including a part of the hollow passage, and the hollow passages 2a, 2b, 2c formed in these part pieces to the remaining hollow passage portions of the product body to be continuous, A step of arranging the ceramic members 13 and 14 having a shape corresponding to the air passage portion, arranging these partial pieces and the ceramic member in the mold 15, a step of pouring the metal melt 16 into the mold 15, and a metal melt 16
After the solidification, the solvent causes the ceramic members 13, 14 to
A step of dissolving and removing.

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 capable of easily and highly accurately manufacturing a product having a hollow path of a complicated path by casting, and have applied for a patent (Japanese Patent Application No. 5-320125). Japanese Patent Application No. 6-24061).
In the methods disclosed in these patent applications, a core having a shape corresponding to the hollow path of the product is formed from a ceramic material, the core is placed in a mold to cast the product body, and then the ceramic is made by a solvent. It is characterized by dissolving and removing the core.

[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 first invention is a method for producing a product having a hollow passage having a small diameter inside a main body, which is configured to include the following steps. . A step of forming a partial piece of the product body including a part of the hollow passage. A ceramic member having a shape corresponding to the hollow passage portion is provided in the remaining hollow passage portion of the product body to be continued from the hollow passage formed in the partial piece. Then, placing these pieces and the ceramic member in the mold that forms the rest of the product body. Pouring the molten metal into the mold. After the molten metal has solidified, the ceramic member is dissolved and removed by the solvent. Process

A second aspect of the present invention is a method for producing a product having a hollow passage having a small diameter inside the main body, which is configured to include the following steps. Step of forming the product body by dividing it into a plurality of divided pieces so as to cut the hollow passage at an appropriate position Step of combining the divided pieces Inserting a removable or removable intermediate material into the hollow passage and filling the ceramic member Step of solidifying by joining step of joining adjacent surfaces of each divided piece with an adhesive step of disappearing or removing the intermediate material to form a cavity in the ceramic member in the hollow passage step of dissolving and removing the ceramic member with a solvent

A third aspect of the present invention is a method of manufacturing a product having a hollow passage having a small diameter inside a main body, which is configured to include the following steps. Step of forming the product body by dividing it into a plurality of divided pieces so that the hollow passages are cut at appropriate positions.Along with combining the divided pieces, a ceramic leak-preventing member is connected to the hollow passages in each divided piece or at the formation portion. Placement process Joining adjacent surfaces of each divided piece with an adhesive Step of dissolving ceramic leak preventer with solvent

[0008]

In the first to third inventions, each of the partial pieces or the divided pieces of the product body including a part of the hollow passage is individually formed. As a result, even if the hollow path of the entire product is long or complicated, the hollow path can be divided into partial pieces or divided pieces to form a short and simple path. Can be manufactured.

In the first aspect of the invention, a ceramic member is disposed in the hollow passage portion of the main body to be continued from the hollow passage formed in the partial piece that is a part of the product body, Then, the remaining body portion is cast by casting the ceramic member. The ceramic member used at this time corresponds to a part of the hollow passage formed in the product body,
Therefore, it is possible to make the shape short and simple enough to withstand the pressure received from the molten metal. The product body formed by the above casting has a structure in which a ceramic member is present in a part of the hollow passage. Therefore, if the ceramic member is dissolved and removed with a solvent, it is possible to form a hollow passage in which no foreign matter remains.

Further, in the second and third inventions, the individually formed divided pieces are combined, and an adhesive such as a brazing material is filled between the adjacent surfaces of the divided pieces to join them. At this time, the adhesive filled between the adjacent surfaces of the divided pieces may enter the hollow passages from the communicating portions of the hollow passages formed in the divided pieces and remain as foreign matter. If the amount of this foreign substance (adhesive) is small, 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, in the second invention, when the divided pieces are combined and joined with an adhesive, a ceramic member is filled in the hollow passage to prevent the adhesive from entering the hollow passage. ing. The filled ceramic member is
After the adhesive for joining the divided pieces has solidified, it can be dissolved and removed using a solution such as caustic soda, so that it does not remain as foreign matter in the hollow passage.

In the present invention, in order to promote the dissolution of the ceramic member, the intermediate member is inserted into the hollow passage together with the ceramic member. As the intermediate material, various materials that can be removed by heating or the like or that can be removed by melting or the like can be used. Suitable materials for the intermediate material include, for example, a string material formed by twisting cotton yarn, a brazing material, a urethane resin material, and a low melting point and soft metal material such as an aluminum alloy or a lead alloy. If this intermediate material is lost or removed by an operation such as heating before melting the ceramic member,
A cavity is created there. As a result, the contact area of the solvent with respect to the ceramic member increases, and dissolution is promoted.

According to the third aspect of the invention, a ceramic leak-preventing member is arranged at the communicating portion of the hollow passage in each divided piece in a combined state to prevent the adhesive from entering the hollow passage. There is. Like the second invention, the ceramic leak-proof member can be dissolved and removed by a solvent and does not remain as a foreign substance in the hollow passage.

The ceramic member and the ceramic leakproof member used in each of the above-mentioned inventions have desired strength, have the property of being dissolved by a solvent, and have heat resistance as required.
As a ceramic material having such characteristics, there is, for example, SiO ₂ ceramics. The SiO ₂ ceramics can be dissolved by caustic soda (solvent).

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of a product manufactured by the method according to the first to third embodiments described below. In these examples, a product such as a manifold in which a hollow passage having curved corners and branch points is formed in a block-shaped body is manufactured. The product body 1 shown in the figure is manufactured by dividing it into a plurality of product parts A, B, C, D which divide the hollow passage 2 respectively, as described later. In the first embodiment, three product parts A, B, C are separately manufactured as the part pieces 10, 11, 12 (see FIG. 6).

2 to 4 show these 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.
(See FIG. 3), the core 4 is placed in the mold 6, and then the metal melt 7 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 thus manufactured, the core 4 made of a ceramic member remains in the hollow passage 2a. 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 partial piece has a simple shape, it is produced by various conventionally known processing methods without using the method disclosed in Japanese Patent Application No. 5-320125. You can also do it.

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 are connected to the remaining hollow passages 2d and 2d, respectively.
The ceramic members 13 and 14 are arranged in the portion 2e (see FIG. 5). These ceramic members 13 and 14 have a shape corresponding to the hollow passages 2d and 2e, and the hollow portions 2 of the partial pieces 10, 11 and 12 that are continuous at both ends.
a, 2b, 2c. In addition, it is preferable that the ceramic members 13 and 14 have cavities formed therein within a range allowed by the strength.

The segment pieces 10 assembled in this way,
11 and 12 and ceramic members 13 and 14 into a mold 15
Place it inside. Here, the mold 15 is sized and shaped so that the remaining part of the product body 1 (product part D in FIG. 1) can be formed. The partial pieces 10, 11 and 12 are formed by the mold 15
Inside, they are arranged at the positions corresponding to the product portions A, B, C in FIG. 1, and the ceramic members 13, 14 are arranged at the positions corresponding to the hollow passages 2d, 2e in FIG.

Subsequently, a molten metal 16 is poured into the mold 15 (see FIG. 5). After the molten metal 16 has solidified, the mold 1
5, the solvent 17 is supplied from the hollow passages 2b, 2c (or 2a), and the ceramic members 13, 1
4 is dissolved and removed (see FIG. 6). Ceramics member 1
Hollow passages 2d and 2e are formed in the places where 3 and 14 have been dissolved and removed.
Are formed, thus completing the product body 1 having the hollow passage 2 as shown in FIG.

By appropriately changing the dimensions of the ceramic member, 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, in FIG.
Only the product parts A, B and C shown in FIG. 2 are mass-produced, and the hollow passages 2b and 2 depending on the dimensions of the ceramic members 13 and 14.
By adjusting the opening position of c (corresponding to the opening position of the material supply port), various manifolds having different opening positions of the material supply port can be easily manufactured at low equipment cost.

If a concave portion or a convex portion is formed on the outer peripheral surface of each of the partial pieces 10, 11 and 12, or if the outer peripheral surface is formed to be a rough surface, the molten metal melts the concave portion or the convex portion at the time of casting. Since it enters into the rough surface, 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.

Next, a second embodiment of the present invention will be described mainly with reference to FIGS. 7 and 8. In this embodiment, the product parts A, B, C, D of the product body 1 shown in FIG.
As divided pieces 20, 21, 22, 23, and these divided pieces 20, 21, 22, 23 are individually manufactured. Of these, the divided pieces 20, 21, 22 may be manufactured by the same method as the partial pieces 10, 11, 12 of the first embodiment (for example, the method shown in FIGS. 2 to 4). The split piece 23 is manufactured by, for example, casting, or the fitting portions of the split pieces 20, 21, 22 are formed by boring, and the hollow passages 2d, 2e are bored from the side surface, and thereafter unnecessary. Perforated part (2 in FIG. 7)
It can be manufactured by embedding a metal material in the f and 2g portions). A small gap for filling the adhesive is formed between the adjacent surfaces of the divided pieces 20 to 23.

Each divided piece 2 individually manufactured in this way
The product body 1 is formed by combining 0 to 23, and the adhesive 24 is placed in the gap provided between the adjacent surfaces of the divided pieces 20 to 23 (see FIG. 7). Adhesive 24
According to the material of each divided piece 20-23, each divided piece 20-
A material that can firmly bond 23 may be appropriately selected. In this embodiment, a brazing material that melts at about 1000 ° C. is used as the adhesive 24. The divided pieces 20 to 23 are assembled in a state in which the brazing material (solid) is sandwiched between the adjacent surfaces of the divided pieces 20 to 23 at room temperature. When a viscous liquid adhesive is used, the adhesive is supplied after the ceramic member 26 is filled in the hollow passage as described later.

After that, the intermediate member 25 is inserted and arranged in the hollow passage 2, and then the ceramic member 26 is poured into the hollow passage 2. In the second embodiment, a cord material made by twisting cotton yarn is used as the intermediate material 25, and the cord material is inserted from the open end surface of the hollow passage 2 so as to extend over the entire length of the hollow passage 2. Si having heat resistance as the ceramic member 26
An O ₂ type material is used and filled in the hollow passage 2 and hardened.

After the ceramic member 26 in the hollow passage 2 hardens, the product body 1 is heated to a temperature at which the adhesive (brazing material) 24 melts. Then, the adhesive 24 is melted and spreads between the adjacent surfaces of the divided pieces 20 to 23 without a gap. At this time, since the ceramic member 26 is filled inside the hollow passage 2, there is no gap even if the melted adhesive 24 leaks to the inner surface side of the hollow passage 2. Further, when the product body 1 is heated to a temperature (about 1000 ° C.) at which the adhesive (brazing material) 24 melts, the intermediate material 25 inserted into the hollow passage 2 is burned by the heat, and the intermediate material 25 is removed. The closed portion becomes the cavity 27 (see FIG. 8).

Next, the ceramic member 26 solidified in the hollow passage 2 is dissolved and removed using a solvent 28. As described above, the SiO ₂ ceramic member 2
Since 6 can be dissolved with caustic soda, caustic soda is used as the solvent 28 in this embodiment.

The solvent 28 may be poured from the open end of the hollow passage 2. Since the burned-out portion of the intermediate member 25 becomes a cavity 27 in the hollow passage 2, the contact area of the poured solvent 28 with the ceramic member 26 is large, and as a result, the ceramic member 26 is rapidly dissolved in a short time. Can be removed. By removing the ceramic member 26 in the hollow passage 2 in this manner, it is possible to form a product having the hollow passage 2 having a smooth inner surface without leakage of the adhesive 24.

Next, referring mainly to FIG. 9, a third embodiment of the present invention will be described. Similar to the second embodiment described above, in this embodiment as well, the product parts A, B, C, D of the product body 1 shown in FIG. 1 are divided into the divided pieces 30, 31, 32, 3 respectively.
3, and these divided pieces 30, 31, 32, 33 are individually manufactured. The manufacturing method of each divided piece 30 to 33 is
Same as the second embodiment.

The product body 1 is formed by combining these divided pieces 30 to 33. At this time, the hollow passage 2 formed in one of the adjacent divided pieces 33 and 30, 31, 32.
In the b, 2c, 2d, and 2e, as shown in advance by the imaginary line in FIG.
4 is slidably inserted. The leak prevention member 34 is a ceramic material that can be dissolved with a solvent such as caustic soda, and is formed in a cross-sectional shape corresponding to the cross section of the hollow passage 2, and has a slight clearance that allows it to slide in the hollow passage 2 in the axial direction. Insert with.

Further, the divided pieces 33 and 30, which are adjacent to each other,
Hollow passages 2d, 2e, 2a formed on the other side of 31, 32
In the inside, at a position (a distance shorter than the length of the leak prevention member 34) slightly entering from the opening end of the adjacent surface,
Protrusions 35 for positioning the leak preventer 34 are provided.

The positioning projections 35 may be formed, for example, by attaching a ceramic material to the inner surface of the hollow passage or by welding solder. The protrusion 35
Is preferably a minute protrusion that does not affect the quality of the product (the accuracy of the inner surface of the hollow passage 2). Also, this protrusion 3
If 5 affects the quality of the product, it must be removed by a polishing operation later. When the protrusions 35 are made of a ceramic material, the protrusions 35 can be dissolved and removed as the leakage preventing member 34 is dissolved and removed by a solvent described later.

When the divided pieces 30 to 33 are combined to form the product main body 1, the adhesive 24 is filled in the gap provided between the adjacent surfaces of the divided pieces 30 to 33 (FIG. 7).
reference). The adhesive 24 is used for each of the divided pieces 3 as in the second embodiment.
A material capable of firmly joining the divided pieces 30 to 33 may be appropriately selected according to the material of 0 to 33. However, when a viscous liquid adhesive is used, the leak-preventing member 34, which will be described later, is placed at a predetermined position in the hollow portion 2 and then filled. In this embodiment, a brazing material that melts at about 1000 ° C. is used as the adhesive 36.

Next, the opening 2 is formed in the hollow passages 2b and 2c.
The compressed air is supplied from h and 2i, and the hollow passage 2a
The air therein is sucked through the opening 2j, and the leak preventing members 34 fitted in the hollow passages 2 are slid until they engage with the protrusions 35, respectively. Leakage prevention member 34 engaged with the protrusion 35
Will be arranged in the communicating portions of the hollow passages 2a to 2e in each of the divided pieces 30 to 33.

In this state, the product body 1 is heated to a temperature at which the adhesive (brazing material) 36 melts. Then, the adhesive 3
6 melt | dissolves and it spreads without a gap between the adjacent surfaces of each division piece 30-33. At this time, since the leak-preventing member 34 is arranged at the communicating portion of the hollow passages 2a to 2e in each of the divided pieces 30 to 33, even if the melted adhesive 36 leaks to the inner surface side of the hollow passage 2, There are no gaps.

After that, the leakage preventing member 34 fitted in the hollow passage 2 is dissolved and removed by using a solvent such as caustic soda. The solvent may be poured from the openings 2h and 2i (or 2j) of the hollow passage 2. By removing the leak preventive member 34 in the hollow passage 2 in this manner, it is possible to form a product having the hollow passage 2 having a smooth inner surface without leakage of the adhesive 36.

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 the form shown in FIG. This 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. In addition, in each of the above-described embodiment methods,
Further, in order to improve the inner surface accuracy in the hollow passage, the ceramic member may be dissolved and removed, and then the final polishing in the hollow passage may be performed. For this finishing polishing, a polishing amount of, for example, about 0.1 mm is sufficient, and can be completed in a short time.

[0039]

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 or a divided piece manufactured in the process of the embodiment of the present invention, and 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 for explaining the first embodiment of the present invention.

FIG. 6 is a vertical cross sectional view for explaining the first embodiment of the present invention subsequent to FIG.

FIG. 7 is a vertical sectional view for explaining a second embodiment of the present invention.

8 is a vertical cross-sectional view for explaining the second embodiment of the present invention, following FIG.

FIG. 9 is a vertical sectional view for explaining a third embodiment of the present invention.

[Explanation of symbols]

 1: Product main body 2: Hollow path 10, 11, 12: Partial piece 13, 14: Ceramic member 15: Mold 16: Molten metal 17: Solvent 20, 21, 22, 23: Divided piece 24: Adhesive 25: Intermediate material 26: Ceramics member 27: Cavity 28: Solvent 30, 31, 32, 33: Divided piece 34: Leak prevention member 35: Protrusion 36: Adhesive

Claims (3)

[Claims] 1. A method of manufacturing a product having a hollow passage having a small diameter inside a main body, comprising the steps of forming a partial piece of the main body including a part of the hollow passage, and a hollow passage formed in the partial piece. A ceramic member having a shape corresponding to the hollow passage portion is arranged in the remaining hollow passage portion of the main body to be continuous, and these segment pieces and the ceramic member are arranged in a mold forming the remaining portion of the main body. A step of pouring a molten metal into the mold, and a step of dissolving and removing the ceramic member with a solvent after the molten metal has solidified, the method for producing a product having a hollow passage, . 2. A method for manufacturing a product having a hollow passage having a small diameter inside a main body, wherein the main body of the product is divided into a plurality of divided pieces so as to cut the hollow passage at an appropriate position. And a step of assembling the respective divided pieces, a step of inserting an disappearing or removable intermediate material into the hollow passage and filling and hardening a ceramics member, and adjoining adjacent surfaces of the respective divided pieces with an adhesive. A product having a hollow passage, which comprises a step, a step of eliminating or removing the intermediate material to form a cavity in the ceramic member in the hollow passage, and a step of dissolving and removing the ceramic member with a solvent. Manufacturing method. 3. A method of manufacturing a product having a small-diameter hollow passage inside a main body, wherein the main body of the product is divided into a plurality of divided pieces so as to cut the hollow passage at an appropriate position. And a step of combining the respective divided pieces, arranging a ceramic leak-proof member in a communicating portion of a hollow path in each of the divided pieces, and a step of joining adjacent surfaces of the divided pieces with an adhesive, And a step of dissolving and removing the ceramic leakproof member with a solvent, the method for producing a product having a hollow passage.