WO2005028142A1

WO2005028142A1 - Core for use in casting

Info

Publication number: WO2005028142A1
Application number: PCT/JP2004/013669
Authority: WO
Inventors: Jun Yaokawa; Koichi Anzai; Youji Yamada
Original assignee: Yamaha Hatsudoki Kabushiki Kaisha
Priority date: 2003-09-17
Filing date: 2004-09-17
Publication date: 2005-03-31
Also published as: US20060185815A1; EP1674173B1; EP2316592A1; EP1674173A4; EP1674173A1; JPWO2005028142A1; ATE496713T1; DE602004031244D1; JP4516024B2

Abstract

A salt core (2) prepared by casting a mixed material from a salt material and a ceramic material, wherein one of chlorides, bromides, carbonates and sulfates of potassium and sodium is used as the salt material, and the ceramic material is a particulate material having a density which is greater than 2.2 g/cm3 and not greater than 4 g/cm3.

Description

Specification

铸 Building core

Technical field

[0001] The present invention relates to a structure formed of a salt material that is loaded into a die used for manufacturing a non-ferrous alloy product, in particular, a die-casting die, and can withstand the high-pressure manufacturing pressure environment. It is about a core.

Background art

[0002] Conventionally, the die-casting method can mass-produce complex-shaped parts with high dimensional accuracy at low cost.

However, depending on the shape, there is a case where a collapsed production core must be used. Conventionally, as a disintegratable core, there is a so-called salt core in addition to a shell core formed using sand. This salt core is an extremely attractive choice when considering productivity.

[0003] That is, since the salt core can be removed by dissolving with hot water or steam after the completion of the production, the use of the salt core makes it possible to produce a sand core (eg, a shell core). Compared with the case of using, the labor of sanding work can be saved and the productivity can be increased. This is because in the case of the shell core, the so-called penetration phenomenon occurs in which the molten metal enters the gaps between the sand grains at the boundary surface with the core and sand cannot be removed.

[0004] For this reason, it is necessary to remove the mold force and the product, apply the product to several knockout machines to remove the internal force, and also remove the hard-to-fall sand by shot blasting. It is also a force that is difficult to put out and costs are increasing.

Such salt cores are disclosed in, for example, Japanese Patent Publication No. 48-17570 (hereinafter simply referred to as Patent Document 1), US Pat. No. 3,963,818 (hereinafter simply referred to as Patent Document 2), and US Pat. As disclosed in US Pat. No. 4,361,181 (hereinafter simply referred to as Patent Document 3) and US Pat. No. 5,154,644 (hereinafter simply referred to as Patent Document 4), sodium salt sodium chloride (NaCl) and potassium chloride ( KC1) is formed as the main material (salt material).

[0005] The salt cores disclosed in Patent Documents 1 to 3 are formed by pressing a salt (eg, sodium chloride, potassium salt, etc.) in a predetermined shape by a press molding method. , This molding It is formed by sintering an object.

The salt core described in Patent Document 4 uses sodium salt as a salt material and is formed into a predetermined shape by a die casting method.

Further, US Pat. No. 4,446,906 (hereinafter simply referred to as Patent Document 5), US Pat. No. 5,803,151 (hereinafter simply referred to as Patent Document 6), and Japanese Patent Publication No. 49-15140 (hereinafter simply referred to as Patent Reference 7), Japanese Patent Publication No. 48-8368 (hereinafter simply referred to as Patent Document 8), Japanese Patent Publication No. 49-46450 (hereinafter simply referred to as Patent Document 9), and US Pat. No. 4,840,219. A book (hereinafter simply referred to as Patent Document 10) discloses a salt core in which ceramics is mixed as a filler in a salt material!

[0006] The salt core disclosed in Patent Document 5 uses silica (SiO 2)

2 Lumina (Al 2 O 3) is used and is formed into a predetermined shape by die casting.

twenty three

The tensile strength of this salt core is described as 150-175 psi, which corresponds to 1.0-3.2 MPa. In the case of shell cores, which are the same collapsible cores, it is common to evaluate the core strength based on the values of the bending strength obtained by the bending strength test method. Can be adopted.

[0007] The bending strength is a barometer that indicates the strength of the core when a bending stress acts on the core.

When bending stress is applied, for example, when the molten metal flows into the cavity at high speed from the gate and hits the inner salt core, or when the core is installed in the mold, impact is applied to the core. Is assumed. The occurrence of such bending stress is a major factor that causes the core to break in the die casting method. Patent Document 5 does not describe this bending strength V. Although the specification says that this core was used to produce the engine block by die casting, the salt core was inferred from the lack of commercial experience. It is presumed that the transverse rupture strength that can withstand the injection speed was not strong.

[0008] In the salt core disclosed in Patent Document 6, particles such as alumina, silica sand, boron nitride (BN), and boron carbide (BC), fibers, whiskers, and the like are used as ceramics for filling. The salt core is formed by molding a mixture of the ceramic for filling and a salt material into a predetermined shape by a pressure molding method and then sintering the mixture. This patent is Seth suggests that salt cores be reinforced with various forms of ceramic materials.

[0009] The salt cores disclosed in Patent Documents 7 and 8 use alumina as a filling ceramic. The salt core disclosed in Patent Document 9 uses silica, alumina, zirconia (ZrO 2), or the like as a ceramic for filling. These patent documents 7—

2

The salt core shown in 9 is formed by construction.

[0010] In a salt core disclosed in Patent Document 10, two types of alumina having different particle sizes are mixed as a ceramic for filling into a salt material, and formed into a predetermined shape by a die casting method. The salt material used for this salt core is a mixed salt obtained by mixing sodium carbonate and sodium carbonate (Na 2 CO 3).

twenty three

[0011] As described above, a salt core using a mixed salt as a salt material is disclosed in US Pat.

No. 303761 (hereinafter simply referred to as Patent Document 11) and Japanese Patent Application Laid-Open No. Sho 50-136225 (hereinafter simply referred to as Patent Documents 12 and ヽぅ).

Patent Document 11 discloses a mixed salt composed of sodium salt and sodium carbonate as in Patent Document 10. Patent Document 12 discloses a mixed salt obtained by mixing sodium carbonate with sodium salt and sodium salt.

[0012] Further, salt materials in which ceramics are mixed in a mixed salt are disclosed in Japanese Patent Publication No. 48-39696 (hereinafter simply referred to as Patent Document 13) and Japanese Patent Application Laid-Open No. 51-50218 (hereinafter simply referred to as Patent Document 1).

4).

Patent Document 13 discloses that sodium carbonate, sodium salt, sodium chloride and potassium salt, a mixed salt that also has a potassium salt, metal oxides such as alumina and zinc oxide (ZnO), and siliceous particles such as silica sand, talc, and clay. The salt material mixed with is shown.

[0013] Patent Document 14 discloses potassium carbonate, sodium sulfate (Na SO), sodium salt sodium salt and salt.

twenty four

A salt material in which silica 'alumina' fibers and the like are mixed in a mixed salt of potassium iodide is shown.

Thus, by making the salt material a mixed salt, the salt material is formed by a single chloride, carbonate or sulfate! The melting point of the salt material can be relatively reduced as compared with the case where the temperature is low. Disclosure of the invention

Problems to be solved by the invention

[0014] The salt cores disclosed in Patent Document 1 and Patent Document 3 and Patent Document 6 described above cannot be formed into a complicated shape because they are formed by a press molding method. There was a problem. As shown in Patent Documents 4, 5, and Patent Documents 10 and 11, such a problem can be solved to some extent by forming a salt core by a fabrication method such as die casting. However, the salt core disclosed in Patent Document 4 has a problem in that the bending strength is low, and there are many restrictions on the product structure performed using the salt core.

[0015] That is, the salt core disclosed in Patent Document 4 is made of only a fragile material itself such as sodium salt sodium and potassium salt sodium (eg, bending strength of 1-11). 5MPa), so that this core is supplied with a low supply pressure of the molten metal and at a low flow rate, for example, a gravity die manufacturing method or a low pressure manufacturing method (LP) so that it is not destroyed during product manufacturing. However, it could not be used for high-pressure high-speed die casting, which is generally called die casting. In addition, the conventional die-casting method has a higher injection pressure of 40-100MPa compared to the gravity die manufacturing method or low-pressure manufacturing method, and the injection speed is high (20-100 mZ seconds at the gate speed). It is difficult to use a core other than the salt core. The supply pressure of the molten metal is high, but in the laminar flow die-casting method and the squeeze die-casting method, etc., in which the speed is kept low, the shell core with increased strength {Bending strength 3-6MPa (Max value 6MPa at present) In this case, as described above, the time required for sand removal after construction is excessively long, and the production cost is significantly increased.

[0016] In order to increase the bending strength of the salt core, as shown in Patent Documents 5 and 10 and Patent Documents 13 and 14, it is considered to mix ceramics as a reinforcing material in the salt material. Can be However, the conventional ceramic-mixed salt core was unable to achieve the expected high flexural strength. This is because ceramic materials are mainly composed of general-purpose industrial materials and natural materials (for example, alumina and silica). Therefore, the ceramic material is sufficiently dispersed in the salt material or is not present in the salt material. It is considered that the cause was that the user did not use the power. The present invention has been made to solve such a problem, and has excellent fluidity, and is formed into a core having a complicated shape by a structure such as a die casting method, a gravity mold manufacturing method, or a low pressure manufacturing method. It is another object of the present invention to provide a salt core that can be applied to a die casting method having a high bending strength as a core.

[0018] In recent years, artificially synthesized ceramics and the like (kaolin is re-melted, pulverized, and classified; for example, pulverized synthetic mullite. Kaolin is granulated and sintered by a rotary kiln for classification. For example, a sintered product of synthetic mullite, precipitated by the flux method, and flux is removed and classified, for example, aluminum borate, and deposited and classified by the gas phase method, for example, silicon carbide nitride Is produced.

Conventionally, these artificially synthesized materials are used as reinforcement materials for reinforced plastics, as heat-resistant piston materials, used as brake materials as an alternative to asbestos, or developed for aerospace. This is an industrial material that has not been developed as a ceramic for strengthening salt cores.

However, a variety of products having various densities, particle sizes, shapes, and the like are commercially available, and the heat resistance and strength stability are remarkably improved as compared with conventional ceramics. The present inventors have reexamined whether these materials can be used as ceramics for salt reinforcement and arrived at the present invention.

Means for solving the problem

[0019] In order to achieve this object, a production core according to the present invention is a production core formed by producing a mixed material of a salt material and a ceramic material.

, And potassium or sodium Shioi匕物, bromides, carbonates, and any one of sulfates, the ceramic material is artificially synthesized density 2. 2 g / cm ³ greater than 4g / cm ³ It has the following granularity.

[0020] The production core according to the second aspect of the present invention is the production core according to the first aspect, wherein the ceramic material is made of a material having a density of 2.79 gZcm ^{3 to} 3.15 gZcm ³ . It is a synthetic mullite.

The manufacturing core according to the invention described in claim 3 is the manufacturing core according to claim 1, wherein the ceramic material is aluminum borate having a density of 2.93 gZcm ^3. is there.

[0021] The production core according to the invention set forth in claim 4 is a production core formed by production of a mixed material of a salt material and a ceramic material, wherein the salt material is made of potassium or potassium. Any one of sodium chloride, bromide, carbonate, and sulfate, wherein the ceramic material has an artificially synthesized particle diameter of 150 m or less and has a granular shape. is there.

The structural core according to the invention as set forth in claim 5 is a structural core formed by forming a mixed material of a salt material and a ceramic material, wherein the salt material is a potassium or sodium salt. Ceramide, bromide, carbonate, or sulfate, and the ceramic material is synthetic mullite, aluminum borate, boron carbide, silicon nitride, silicon carbide, aluminum nitride, titanate. The aluminum cordierite and the alumina exhibit any one of granularity.

[0022] A structural core according to claim 6 is a structural core obtained by forming a mixed material of a salt material and a ceramic material by structure, wherein the salt material is potassium or Any one of sodium chloride, bromide, carbonate, and sulfate is used, and the ceramic material is aluminum borate, silicon nitride, silicon carbide, potassium hexatitanate, potassium titanate 8 And whisker of any one of zinc oxide.

The manufacturing core according to the invention described in claim 7 is the manufacturing core according to the invention described in claim 6, wherein the ceramic material is aluminum borate whisker.

[0023] The production core according to the invention according to claim 8 is a production core formed by producing a mixed material of a salt material and a ceramic material, wherein the salt material is potassium or a mixed salt obtained by adding a carbonate or sulfate of potassium or sodium with respect to sodium Shioi匕物, the ceramic material, artificially synthesized density 2. 2 g / cm ³ greater than 4g / cm ³ It has the following granularity.

The production core according to the ninth aspect of the present invention is the production core according to the eighth aspect, wherein the ceramic material is made of a material having a density of 2.79 g / cm ³ to 3.15 g / cm ^3. Mullite.

The manufacturing core according to the invention described in claim 10 is the same as the manufacturing core according to claim 8. In the manufacturing core, the ceramic material was aluminum borate having a density of 2.93 gZcm ³ .

The manufacturing core according to the invention according to claim 11 is a manufacturing core formed by manufacturing a mixed material of a salt material and a ceramic material, wherein the salt material is made of potassium or sodium. A mixed salt obtained by adding a carbonate or a sulfate of potassium or sodium to a salted sardine, wherein the ceramic material has an artificially synthesized particle diameter of 150 μm or less and has a granular shape. It is.

[0025] A production core according to the invention as set forth in claim 12, is a production core formed by production of a mixed material of a salt material and a ceramic material, wherein the salt material is made of a ceramic. Alternatively, a mixed salt obtained by adding potassium or sodium carbonate or sulfate to sodium chloride is used, and the ceramic material is made of synthetic mullite, aluminum borate, boron carbide, silicon nitride, silicon carbide, It has a granular shape of any one of aluminum nitride, aluminum titanate, cordierite, and alumina.

[0026] A production core according to the invention according to claim 13 is a production core formed by production of a mixed material of a salt material and a ceramic material, wherein the salt material is made of a ceramic. Alternatively, a mixed salt obtained by adding a carbonate or a sulfate of potassium or sodium to a sodium chloride is used, and the ceramic material is made of aluminum borate, silicon nitride, silicon carbide, potassium hexatitanate, 8 Whisker of any one of potassium titanate and zinc oxide.

[0027] The core for production according to the invention described in claim 14 is the core for production according to the invention described in claim 13, wherein the ceramic material is aluminum borate whisker. The manufacturing core according to the invention according to the invention is the manufacturing core according to any one of the inventions described in claims 8 to 14, wherein the mixed salt is prepared by mixing salt salt and sodium carbonate. It was formed.

The invention's effect

[0028] As described above, according to the present invention, a salt core in which a ceramic material is sufficiently dispersed in a salt material can be formed by fabrication. Therefore, the core for production according to the present invention has a characteristic that it can be removed by water (including hot water and steam) after the production, and can be formed into a complicated shape by the production. Strengthening materials that have both strength and ceramic material strength will increase the bending strength more than expected. For this reason, the manufacturing core according to the present invention can be used, for example, in a conventional casting machine, which has been difficult in the past. Therefore, the degree of freedom of construction can be improved.

According to the second aspect of the present invention, a salt core in which synthetic mullite is sufficiently dispersed in a salt material can be formed by forging.

According to the third aspect of the present invention, a salt core in which aluminum borate is sufficiently dispersed in a salt material can be formed by forging.

[0030] According to the invention set forth in claim 4, a salt core in which the ceramic material is sufficiently dispersed in the salt material can be formed by forging.

Therefore, the core for production according to the present invention has a characteristic that it can be removed by water (including hot water and steam) after the production, and can be formed into a complicated shape by the production. Strengthening materials that have both strength and ceramic material strength will increase the bending strength more than expected. For this reason, the manufacturing core according to the present invention can be used, for example, in a die-casting machine, which has been difficult in the past, and is also handled with special care when mounting it on other types. Since there is no necessity, the degree of freedom of construction can be improved.

[0031] According to the invention set forth in claim 5, a salt core sufficiently reinforced by a ceramic material having a granular shape can be formed.

Therefore, the core for production according to the present invention has a characteristic that it can be removed by water (including hot water or steam) after the production, and can be formed into a complicated shape by the production. As for the strength, the bending strength is increased more than expected by the reinforcing material, which is a granular ceramic material. For this reason, the manufacturing core according to the present invention can be used not only in a die-casting machine, for example, which has been difficult in the past, but also needs to be handled with special care when mounting it on other types. Because there is no, the degree of freedom of construction can be improved. Since one type of ceramic material is used, the salt core is dissolved in water. The ceramic material is collected and reused.

[0032] According to the invention set forth in claim 6, it is possible to form a salt core sufficiently stiffened by a whisker of ceramic material strength.

Therefore, the core for production according to the present invention has a characteristic that it can be removed by water (including hot water or steam) after the production, and can be formed into a complicated shape by the production. The strength is sufficiently strengthened by the whisker, which also has the strength of the ceramic material, and the bending strength is increased more than expected. For this reason, the manufacturing core according to the present invention can be used not only in a conventionally difficult die-casting machine, for example, but also with special care when mounting it on other types. Since there is no need to handle, the degree of freedom of construction can be improved. In addition, since one type of ceramic material is used, the salt core is dissolved in water to recover the ceramic material, which can be reused.

According to the invention described in claim 7, a salt core sufficiently reinforced by aluminum borate whiskers can be formed by structure.

[0033] According to the invention of claim 8, a salt core in which a ceramic material is sufficiently dispersed in a salt material made of a mixed salt can be formed by structure.

Therefore, the core for production according to the present invention has a characteristic that it can be removed by water (including hot water or steam) after the production, and can be formed into a complicated shape by the production. As for the strength, the bending strength will be increased more than expected by the strengthening material which is a ceramic material. For this reason, the manufacturing core according to the present invention can be used not only in, for example, a die-casting machine, which has been difficult in the past, but also needs to be handled with special care when mounting it on other types. Therefore, the degree of freedom of construction can be improved.

Further, the salt core is a mixed salt of a salt material, and has a relatively low melting point. For this reason, the temperature at the time of manufacturing this salt core can be lowered, and the manufacturing cost of the salt core can be reduced. Further, a salt core with small wrinkles formed on the core surface can be provided.

[0034] According to the invention as set forth in claim 9, a salt core in which synthetic mullite is sufficiently dispersed in a salt material composed of a mixed salt can be formed by structure. According to the invention of claim 10, a salt core in which aluminum borate is sufficiently dispersed in a salt material composed of a mixed salt can be formed by a structure.

According to the eleventh aspect of the present invention, a salt core in which a ceramic material is sufficiently dispersed in a salt material made of a mixed salt can be formed by structure.

According to the twelfth aspect of the present invention, the granular ceramic material is sufficiently dispersed in the salt material having mixed salt strength, and a salt core sufficiently reinforced by the ceramic material can be formed. .

Therefore, the core for production according to the present invention has a characteristic that it can be removed by water (including hot water or steam) after the production, and can be formed into a complicated shape by the production. As for the strength, the bending strength is increased more than expected by the reinforcing material, which is a granular ceramic material. For this reason, the manufacturing core according to the present invention can be used not only in a die-casting machine, for example, which has been difficult in the past, but also needs to be handled with special care when mounting it on other types. There is no way to improve the freedom of construction.

Further, the salt core is a mixed salt of a salt material, and has a relatively low melting point. For this reason, the temperature at the time of manufacturing this salt core can be lowered, and the manufacturing cost of the salt core can be reduced. Furthermore, salt cores with small wrinkles formed on the core surface Can be provided.

According to the invention as set forth in claim 13, the salt material, which is also a ceramic, is sufficiently dispersed in the salt material, which is a mixed salt, and a salt core which is sufficiently strengthened by the whiskers can be formed.

[0038] According to the invention as set forth in claim 14, the whisker force made of aluminum borate is sufficiently dispersed in the salt material having a mixed salt force, and a salt core sufficiently reinforced by the whiskers can be formed. it can. For this reason, a strong salt core having a low melting point and can be formed by forging.

According to the invention of claim 15, potassium chloride and sodium carbonate are easily available and inexpensive. Therefore, according to the invention, the production core made of the salt material composed of the mixed salt is used. Manufacturing costs can be reduced.

Brief Description of Drawings

FIG. 1 is a perspective view showing a cylinder block when manufactured using the manufacturing core according to the present invention.

FIG. 2 is a graph showing a relationship between a mixed amount of synthetic mullite and bending strength.

FIG. 3 is a graph showing a relationship between a mixed amount of synthetic mullite and bending strength.

FIG. 4 is a view showing a bending test piece. FIG. 5 is a graph showing a relationship between a bending test piece and a bending force.

FIG. 6 is a graph showing the relationship between the amount of aluminum borate mixed and the transverse rupture strength.

FIG. 7 is a graph showing the relationship between the mixing amount of silicon nitride and the bending strength.

FIG. 8 is a graph showing the relationship between the mixing amount of silicon carbide and bending strength.

FIG. 9 is a graph showing the relationship between the mixing amount of aluminum nitride and the transverse rupture strength.

FIG. 10 is a graph showing the relationship between the amount of boron carbide mixed and the transverse rupture strength.

FIG. 11 is a graph showing the relationship between the mixing amount of aluminum titanate and spinel and the transverse rupture strength.

FIG. 12 is a graph showing the relationship between the mixed amount of alumina and the transverse rupture strength.

FIG. 13 is a graph showing the relationship between the amounts of all ceramic materials shown in the first to eighth embodiments and the transverse rupture strength.

FIG. 14 is a graph showing the relationship between the mixing amount of all the ceramic materials shown in the first to eighth embodiments and the bending strength.

FIG. 15 is a diagram showing conditions for mixing potassium salt and ceramic materials.

[16] FIG. 16 is a diagram showing the relationship between the mixing ratio of the granular ceramic material and the fluidity. FIG. 17 is a diagram showing the relationship between the mixing ratio of the granular ceramic material and the fluidity. [18] FIG. 18 is a diagram showing the relationship between the mixing ratio of the granular ceramic material and the fluidity.

[FIG. 19] FIG. 19 is a graph showing the relationship between the mixing amount of aluminum borate whis force and bending strength.

FIG. 20 is a graph showing the relationship between the mixing amount of the silicon nitride force and the silicon carbide force and the transverse rupture strength.

FIG. 21 is a graph showing the relationship between the mixing amount of potassium titanate powder and bending strength.

FIG. 22 is a graph showing the relationship between the mixing amount of the Zi-Dani zinc wiping force and the transverse rupture strength.

[FIG. 23] FIG. 23 is a graph showing the relationship between the mixing amount of all the forces and the bending strength shown in the ninth to twelfth embodiments.

[FIG. 24] FIG. 24 is a diagram showing a relationship between a mixing ratio of ceramics force and fluidity.

[Figure 25] Figure 25 shows the mixing of potassium bromide or sodium bromide with aluminum borate power. It is a graph which shows the relationship between quantity and bending strength.

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment)

Hereinafter, an embodiment of a manufacturing core according to the present invention will be described in detail with reference to FIGS.

FIG. 1 is a perspective view of a cylinder block manufactured by using the manufacturing core according to the present invention, and the figure is drawn in a partially broken state. 2 and 3 are graphs showing the relationship between the amount of synthetic mullite mixed and the bending strength, FIG. 4 is a diagram showing the bending test piece, and FIG. 5 is a graph showing the relationship between the weight of the bending test piece and the bending strength. It is a graph which shows a relationship.

In FIG. 1, what is indicated by reference numeral 1 is an engine cylinder block manufactured using a salt core 2 as a manufacturing core according to the present invention. The cylinder block 1 is for forming a water-cooled four-cycle four-cylinder engine for a motorcycle, and is formed into a predetermined shape by a die casting method. The cylinder block 1 according to the present embodiment has a cylinder body 4 having four cylinder bores 3, 3,... And an upper crankcase 5 extending downward from the lower end of the cylinder body 4 and integrally formed. The upper crankcase 5 has a lower crankcase (not shown) attached to a lower end thereof, and rotatably supports a crankshaft (not shown) in cooperation with the lower crankcase.

[0042] The above-mentioned cylinder body 4 is a V, so-called closed deck type, and has a water jacket 6 formed therein using the salt core 2 according to the present invention. The water jacket 6 includes a cooling water inlet 8 formed in a cooling water passage forming portion 7 projecting from one side of the cylinder body 4 and extending in the direction in which the cylinder bores 3 are arranged, and a cooling water passage forming portion 7. A cooling water distribution passage (not shown) formed inside; a main cooling water passage 9 which is communicated with the cooling water distribution passage and is formed so as to cover the periphery of all cylinder bores 3; The communication passage 10 extends upward from the cooling water passage 9 in the figure and opens to the mating surface 4 a at the upper end of the cylinder body 4.

That is, the water jacket 6 supplies the cooling water flowing from the cooling water inlet 8 to the main cooling water passage 9 around the cylinder bore through the cooling water distribution passage. Cooling water in cylinder head (not shown) from 9 through communication passage 10 It is configured to lead to the passage. By forming the water jacket 6 in this manner, the cylinder body 4 has a ceiling 10 of the cylinder body 4 except that the communication passage 10 of the water jacket 6 is opened on the mating surface 4a at the upper end to which the cylinder head is connected. It is now covered by a wall (the wall that forms the mating surface 4a), resulting in a closed deck configuration.

[0044] The salt core 2 for forming the water jacket is formed in a shape in which respective parts of the water jacket 6 are integrally connected. In FIG. 1, the shape of the salt core 2 (the shape of the water jacket 6) is drawn in a state where a part of the cylinder body 4 is broken so that it can be easily understood.

The salt core 2 is formed into a water jacket 6 by a die casting method using a core material composed of a mixture of a salt material and a ceramic material described later. As shown in FIG. 1, the salt core 2 according to this embodiment has a passage forming portion 2a that forms a cooling water inlet 8 and a cooling water distribution passage, and an annular shape that surrounds four cylinder bores 3. The portion 2b and a plurality of convex portions 2c projecting upward from the annular portion 2b are all integrally formed. The communication passage 10 of the water jacket 6 is formed by these projections 2c. As is well known, the salt core 2 is supported at a predetermined position in a mold (not shown) by a skirting board (not shown) at the time of fabrication, and is dissolved by hot water or steam after the fabrication. And remove.

[0045] The salt core 2 is removed after fabrication by immersing the cylinder block 1 in a water tank (not shown) in which hot water is stored. By immersing the cylinder block 1 in the water tank in this way, the passage forming portion 2a of the salt core 2 and the convex portion 2c exposed on the mating surface 4a come into contact with the hot water and dissolve, and this dissolving portion gradually disappears. And finally all parts are dissolved. In this core removing step, hot water or steam can be sprayed with a hole force and pressure in order to promote the dissolution of the salt core 2 remaining in the water jacket 6. In this salt core 2, a skirting board can be inserted instead of the convex portion 2c at a portion where the convex portion 2c is formed.

As the salt core 2 according to the present embodiment, for example, potassium salt salt is used as a salt material, and a synthetic mullite [3A10.2SiO {Itochu

2 3 2

Tech Co., Ltd. MM-325mesh mixed amount 40wt%}] is used. This salt core 2 In forming by the die casting method, first, a mixture of a salt material and a ceramic material is heated to melt the salt material, and the molten material is stirred by sufficiently dispersing the ceramic material to form a mixed molten metal. . Then, the mixed molten metal is injected into the mold for the salt core under high pressure to solidify, and after solidification, the mold force is removed.

[0047] In selecting synthetic mullite as a ceramic material, a plurality of synthetic mullites as shown in Table 1 below are selected from commercially available granular (powder) synthetic mullites. This was done by selecting what could be used by the following experiment.

[Table 1]

[0049] In Table 1, the product name is an indication for specifying the synthetic mullite used by the manufacturer at the time of sale. The trial mixing amount indicates the ratio of the weight of the synthetic mullite mixed with the salted mullite. From the synthetic mullites shown in Table 1, those that can be used in the production were tested. After heating the mixture to dissolve potassium salt and stirring well, the dissolution container is turned upside down and turned upside down to determine whether the molten metal flows out. Was performed by confirming. According to this experiment, a material having fluidity in the molten metal in a state where the melting container was returned as described above was selected as a material that can be manufactured. The results are shown in Table 1 and FIGS.

[0050] A crucible made of INCONEL X-750 or a high-alumina tamman tube was used as the dissolving vessel described above. The dissolution of potassium salt was carried out by placing a dissolution vessel containing potassium chloride in an electric resistance furnace and heating it in the atmosphere. The fabrication was performed by injecting the molten metal at a temperature of 800 ° C into a mold at about 25 ° C. After fabrication, in order to prevent the test piece from sticking to the mold due to heat shrinkage, about 20 seconds after the injection of the molten metal, the test piece was also taken out of the mold and cooled by air cooling at room temperature.

[0051] In this experiment, as shown in Table 1 and Fig. 15, CeraBeads # 650 exhibited fluidity at 30%, 40%, 50% and 60%. From this, it was considered that CeraBeads # 650 had sufficient fluidity when the mixing amount was 60% or less and could be manufactured, but it cannot be used for manufacturing because it precipitates at the bottom of the dissolution vessel. understood. (Table 1, Figure 15, Figure 16)

CeraBeads # 1700 was found to be fluid at 20%, 30%, 40%, 50% and 60%. From this, it is considered that CeraBeads # 1700 has sufficient fluidity when the mixing amount is 60% or less and can be manufactured.

[0052] CeraBeads # 1450 exhibited fluidity at mixing powers of 0%, 50% and 60%. This fact suggests that CeraBeads # 1450 has sufficient fluidity when the mixing amount is 60% or less, and is considered to be manufacturable. It was also confirmed that the deviation between CeraBeads # 1700 and # 1450 was dispersed in the molten potassium chloride. (Table 1, Figure 15, Figure 16)

MM-325mesh was found to be fluid at 10%, 20%, 30% and 40%. This means that MM-325mesh has sufficient fluidity if the mixing amount is 40% or less. , It is considered to be configurable. In addition, it was confirmed that MM-325mesh was dispersed in the molten salt of Shii-dani potassium. (Table 1, Figure 15, Figure 17)

[0053] With MM-200mesh, MM-150mesh, MM-IOOmesh, and SM-325mesh, fluidity was observed at mixing amounts of 20%, 30% and 40%. From this, it is considered that MM-200mesh, MM-150mesh, MM-100mesh, and SM-325mesh have sufficient fluidity if the mixing amount is 40% or less, and can be manufactured. In addition, it was also confirmed that all of these were dispersed in the molten salt of potassium salt. (Table 1, Figure 15, Figure 17)

[0054] MM35-lOOmesh has been tested only with the mixing amounts of 30% and 40%. Although fluidity is observed with this mixing amount (see Table 1, Fig. 17), the dissolution vessel It settled at the bottom (see Table 1, Figure 15), and was found to be unsuitable as a material.

MM-16mesh was found to be fluid at 20%, 30%, and 40%, but settled at the bottom of the dissolution vessel and was unsuitable as a material. In Table 1, CeraBeads is a sintered product and MM is a crushed product.

Of these ceramic materials, except for the precipitated material other than MM-16mesh, using each of the mixing amounts, a bending test piece was prepared as shown in Tables 2, 3 and 4 below, and the bending strength was measured. When the degree was determined, the results shown in FIGS. 2 and 3 were obtained.

[Table 2]

699CT0 / l700Zdf / X3d YZ ΐ Simple SOOZ OAV

£ l0 / ^ 00Zdf / X3d 33 ΐ ΐ Easy SOOZ OAV [0058] As shown in Table 2, five MM-325mesh bending test pieces were formed with five samples each having a mixing amount of 0% and 10%, and seven samples each having a mixing amount of 20% and a mixing amount of 30%. Five were made and eight were made with a 40% mixture. The bending test specimens shown in Tables 2, 3 and 4 were formed by forming into a rectangular cross-section rod with a width of 18 mm, a height of 20 mm and a length of about 120 mm as shown in Fig. 4. did. The flexural test specimens were prepared in the same manner as described above for confirming the fluidity by placing the salt and potassium in a crucible or Tamman tube made of INCONEL X-750 and heating in a furnace to dissolve the salt and potassium. After that, a well-stirred molten metal was poured into a mold. The temperature of the molten metal was 800 ° C.

[0059] The bending strength is measured by supporting the center of the bending test specimen at two points with a spacing of 50mm, and pressing a middle part of these supporting points with a pressing device having two pressing points with a spacing of 10mm. Pressing was performed by the following equation based on the load when the bending test piece was broken.

σ = 3Pm / bh ^2-

In this equation 1, σ: bending strength [MPa], Ρ: bending load [N], m = 20 mm, b = 18 mm, h = 20 mm.

As shown in FIG. 2, it was found that the bending strength of the synthetic mullite (MM-325mesh) increased almost in proportion to the mixing amount. Note that the solid line in FIG. 2 is an approximate curve drawn using the least squares method. The bending strength differs even when the mixing amount is the same, because about 10% of the cavities are formed in the test piece, and the mixing amount of the ceramic material is slightly uneven. Was the cause. In order to confirm this, bending force against the weight of the test piece was determined. As shown in FIG. 5, it was found that both of these were in a substantially proportional relationship.

[0061] Therefore, as can be seen from Fig. 2, the salt core 2 obtained by mixing synthetic mullite (MM-325mesh) with potassium chloride has a mixing amount of synthetic mullite in the range of 25% to 40%. In addition, the maximum bending strength is about 14 MPa, and the bending strength (about 8 MPa) that can be used in the die casting method is obtained. Such a fact means that the salt core 2 according to this embodiment can be used for most conventional production methods including the die casting method.

[0062] As a result, by using the salt core 2, the degree of freedom in the structure, such as the shape of the pressure at the time of pouring, can be improved. Note that the present inventors have found that the maximum core strength of the shell core, which is said to be stronger than the salt core at present, at the current technical level is about 6MP. Therefore, the target transverse rupture strength of the salt core applicable to the die casting method was set to at least 8MPa.

In addition, as can be seen from Fig. 3, other MM-16 ceramics, CeraBeads # 1700, CeraBeads # 1450, and CeraBeads # 650 also have high flexural strength similar to MM-325 mesh for ceramic materials made of synthetic mullite. It turned out to be obtained.

[0063] was able to form a salt core 2 as thus bending strength is increased, the density of the synthetic mullite ^{(2. 79g / cm 3 - 3.} 15g / cm 3) is Shioi The individual particles of synthetic mullite are substantially uniformly dispersed and solidified in the salty dangling potassium in the molten state, which is appropriately larger than the density of the dangling potassium in the molten state (1.57 gZcm ³ ), thereby solidifying the inside of the salt. This is thought to be because the crack growth is suppressed. This is evident from the fact that MM-16mesh and CeraBeads # 650, which precipitate, have high strength.

[0064] Further, since the salt core 2 is a substance in which potassium chloride as a main component is dissolved in warm water, it can be removed by being dissolved in warm water after production. That is, since the salt core 2 is removed by immersing the structure formed using the salt core 2 in, for example, warm water, when the shell core is used, for example, similarly to the conventional salt core. In comparison, the cost in the core removal process can be reduced.

[0065] Further, the ceramic material mixed with the salt core 2 is only one kind of synthetic mullite, and the salt core 2 is separated by dissolving the salt core 2 in water (hot water) as described above. . Therefore, the ceramic material can be easily reused by drying it. That is, since the ceramic material can be reused, the manufacturing cost of the salt core 2 can be reduced. If there is more than one ceramic material, even if the salt core is recovered by dissolving it in warm water, the mixing ratio of the recovered ceramic material becomes unstable and cannot be controlled, and the ceramic material cannot be reused. It becomes difficult.

(Second Embodiment)

The salt core according to the present invention can use granular aluminum borate (9A1 O. 2B O) as a ceramic material. Aluminum borate mixed with potassium salt

2 3 2 3

As a result, the bending strength as shown in FIG. 6 was obtained.

FIG. 6 is a graph showing the relationship between the amount of aluminum borate mixed and the bending strength. Figure 6 The bending strength shown was obtained by performing the experiment shown in the first embodiment using aluminum borate as a ceramic material. The line in FIG. 6 is an approximate curve drawn by using the least squares method.

As the aluminum borate used in the experiment, three types shown in Table 5 below were selected from commercially available granular ones.

[Table 5]

Ceramic name Product name Composition Shape Manufacturer name Density (g / cm3) Particle size (μηι) Trial mixing amount (wt%) Maximum mixing amount (wt%) Aluminum borate Albolite PF03 9AI203.2B203 Shaped Shikoku Chemical Industry Co., Ltd. 2.93 2.3 10,15, x20, x30 15 Boric acid Albolite PF08 9AI203.2B203 Granular Shikoku Chemicals Co., Ltd. 2.93 7.3 10,15,20, x30 20 Boric acid Albolite PC30 9AI203.2B203 Granular Shikoku Chemicals 2.93 48.92 10,20,30,35, x40 35

X: No liquidity

S: precipitation

[0068] Of the three types of aluminum borate shown in Table 5, those that could be used in the production by judging the fluidity of the molten metal were those with 10% and 15% Albolite PF03 mixture. ,

The mixing amounts of Albolite PF08 were 10%, 15% and 20%, and the mixing amounts of Albolite PC30 were 10%, 20%, 30% and 35% (see Table 5, FIG. 16). From this,

Albolite PF03 has a mixing amount of 15% or less, Albolite PF08 has a mixing amount of 20% or less, and Albolite PC30 has a mixing amount of 35% or less. Conceivable.

[0069] It was also confirmed that these aluminum borates disperse in the molten salt of potassium salt (see Fig. 15). The density of each of these aluminum borates is 2.93 gZcm ³ , the particle size of Albolite PF03 is 2.3 μm, the particle size of Albolite PF08 is 7.3 μm, and the particle size of Albolite PC30 is The diameter is 48.92 μm.

As shown in Table 6 below, bending test pieces were prepared for each of the three types of aluminum borate having different particle diameters, and the bending strength was determined.

[Table 6]

[0071] When aluminum borate is used as a ceramic material in this way, as shown in Fig. 6, by setting the mixing amount to 10% to 20%, the transverse rupture strength may become larger than 8 MPa. understood.

Also, as shown in Fig. 6, the bending strength of aluminum borate is hardly affected by the particle size! /, That's half IJ.

Therefore, it can be said that the same effect as when the first embodiment is adopted can be obtained even when aluminum borate is used as the ceramic material as described above.

(Third Embodiment)

The salt core according to the present invention is formed of granular silicon nitride (SiN) as a ceramic material.

3 4

) Can be used. By mixing silicon nitride with potassium salt, a bending strength as shown in FIG. 7 was obtained.

FIG. 7 is a graph showing the relationship between the amount of silicon nitride mixed and the transverse rupture strength. The flexural strength shown in FIG. 7 was obtained by performing the experiment shown in the first embodiment using silicon nitride as a ceramic material. Note that the line in FIG. 7 is an approximation curve drawn using the least squares method.

As the silicon nitride used in conducting the experiment, four types shown in Table 7 below were selected from among commercially available, granular ones.

[0073] [Table 7]

Of the four types shown below: As shown in Table 7 and FIG. 17, the results were as follows: 20% and 25% of NP-600, 20%, 30% and 40% of SN-7, and They were 20%, 30%, 35% and 40%, and 10%, 20% and 25% of HM-5MF. From this, NP-600 has a mixing amount of 25% or less, SN-7 has a mixing amount of 0% or less, SN-9 has a mixing amount of 40% or less, and HM-5MF has a mixing amount of 40% or less. If the mixing amount is 25% or less, it is considered that it can be manufactured.

[0075] It was also confirmed that the four types of ceramic materials were dispersed in the molten salt of Shii-dani potassium (see Fig. 15).

NP- 600, SN- 7 and SN- 9 is density at 3. 18gZcm ^3, HM- density of 5MF is 3. 19g Zcm ^3. These four types of silicon nitride have different particle sizes.

With respect to the above four kinds of silicon nitride, bending test pieces were prepared for each mixing amount as shown in Table 8 below, and bending strength was determined.

[0076] [Table 8]

CT0 / l700Zdf / X3d 38 ΐ Simple SOOZ OAV [0077] As described above, when silicon nitride is used as a ceramic material, it was found that, as shown in Fig. 7, by setting the mixing amount to 20% or more, the transverse rupture strength became larger than 8 MPa. .

Further, as shown in FIG. 7, it can be seen that the transverse rupture strength of silicon nitride is hardly affected by the grain size.

Therefore, as described above, it can be said that the use of silicon nitride as the ceramic material has the same effect as when the first embodiment is employed.

(Fourth Embodiment)

The salt core according to the present invention can use granular silicon carbide (SiC) as the ceramic material. By mixing the silicon carbide with the potassium salt, a bending strength as shown in FIG. 8 was obtained.

FIG. 8 is a graph showing the relationship between the amount of silicon carbide mixed and the bending strength. The flexural strength shown in FIG. 8 was obtained by performing the experiment shown in the first embodiment using silicon carbide as a ceramic material. Note that the line in FIG. 8 is an approximation curve drawn using the least squares method.

As the silicon carbide used in conducting the experiment, three types shown in Table 9 below were selected from among commercially available granular materials.

[0079] [Table 9]

Judging from the fluidity of the molten metal, it was found that the three types of silicon carbide shown in Table 9 can be used for production in a mixed amount of 10%, 20%, 30%, 40% and 45% (see Fig. 18). ). For this reason, it is considered that all three types of silicon carbide can be manufactured if the mixing amount is 45% or less. It was also confirmed that these silicon carbides were dispersed in the molten salt of Shii-dani potassium (see FIG. 15). Each of these silicon carbides has a density of 3.23 g / cm ³ and different particle sizes.

As shown in Table 10 below, bending test pieces were prepared for each of the three types of silicon carbide described above, and the bending strength was determined.

[Table 10]

When using silicon carbide as a ceramic material in this way, as shown in Fig. 8, In addition, it was found that the bending strength became larger than 8 MPa by setting the mixing amount to 25% -30% or more.

Also, as shown in FIG. 8, it can be seen that the transverse rupture strength of the silicon carbide is hardly affected by the particle size.

Therefore, as described above, it can be said that the same effect as when the first embodiment is adopted can be obtained even if silicon carbide is used as the ceramic material.

(Fifth Embodiment)

The salt core according to the present invention can use granular aluminum nitride (A1N) as a ceramic material. By mixing aluminum nitride with potassium salt, a transverse rupture strength as shown in FIG. 9 was obtained.

FIG. 9 is a graph showing the relationship between the mixing amount of aluminum nitride and the bending strength. The transverse rupture strength shown in FIG. 9 was obtained by performing the experiment shown in the first embodiment using aluminum nitride as a ceramic material. Note that the line in FIG. 9 is an approximate curve drawn using the least squares method.

Aluminum nitride used in the experiment was selected from two types shown in Table 11 below from among commercially available granular ones.

[0084] [Table 11]

It was found that the two types of aluminum nitride shown in Table 11 can be used for production with a flowability of 20%, 30%, and 40% in terms of fluidity (see Table 11, FIG. 18). From this, it is considered that both types of aluminum nitride can be manufactured if the mixing amount is 40%. It was confirmed that all of these aluminum nitrides were dispersed in the molten salt of potassium salt (see FIG. 15). These aluminum nitrides all have a density of 3.25 g / cm ³ and have different particle sizes.

As shown in Table 12 below, bending test pieces were prepared for each of the two types of aluminum nitride described above, and the bending strength was determined.

[0086] [Table 12]

[0087] As described above, when aluminum nitride is used as a ceramic material, it was found that, as shown in Fig. 9, by setting the mixing amount to 15% or more, the transverse rupture strength became larger than 8 MPa.

Also, as shown in FIG. 9, the transverse rupture strength of aluminum nitride is hardly affected by the grain size.

Therefore, even if aluminum nitride is used as the ceramic material as described above, It can be said that the same effect as when the embodiment is adopted is achieved.

(Sixth Embodiment)

The salt core according to the present invention is a boron carbide (B C) which exhibits a granular shape as a ceramic material.

4 can be used. By mixing boron carbide with potassium salt, a transverse rupture strength as shown in FIG. 10 was obtained.

FIG. 10 is a graph showing the relationship between the mixing amount of boron carbide and the bending strength. The transverse rupture strength shown in FIG. 10 was obtained by performing the experiment shown in the first embodiment using boron carbide as a ceramic material. Note that the line in FIG. 10 is an approximate curve drawn using the least squares method.

As the boron carbide used in the experiment, three types shown in Table 13 below were selected from commercially available granular ones.

[Table 13]

Of the three types of boron carbide shown in Table 13, those that could also be used for the production of fluidity were # 1200 mixed with 20%, 30%, and 33.75%, and S1 and S3 Were 20%, 30% and 40% (see Table 13 and Figure 16). From this, # 1200 is mixed If the volume is 33.75% or less, SI and S3 are considered to be manufacturable if the mixing power is 0% or less. Of these three types of boron carbide, S3 was also found to be capable of precipitating in the molten potassium chloride. Other # 1200 and S1 were also confirmed to disperse (see Fig. 15). These boron carbides have a density of 2.51 g / cm ³ and different particle diameters.

For the above three types of boron carbide, bending test pieces were prepared for each mixing amount as shown in Table 14 below, and the bending strength was determined.

[Table 14]

[0092] When boron carbide is used as a ceramic material in this way, as shown in Fig. 10, the flexural strength is increased by setting the mixing amount between sample name # 1200 and sample name S1 to 20% or more. It turned out to be larger than 8MPa. In addition, as shown in FIG. 10, it can be seen that the dispersed S3 has no strength.

Therefore, as described above, it can be said that the use of boron carbide as the ceramic material has the same effect as when the first embodiment is employed.

(Seventh Embodiment)

The salt core according to the present invention can use granular aluminum titanate (Al TiO) or spinel (cordierite: MgO. Al O) as a ceramic material. This

2 5 2 3

By mixing these ceramic materials with potassium salt, a bending strength as shown in FIG. 11 was obtained.

FIG. 11 is a graph showing the relationship between the mixing amount of aluminum titanate and spinel and the bending strength. The transverse rupture strength shown in FIG. 11 was obtained by performing the experiment shown in the first embodiment using aluminum titanate and spinel as ceramic materials. Note that the line in FIG. 11 is an approximate curve drawn using the least squares method.

Aluminum titanate and spinel used in conducting the experiment were selected from commercially available, granular ones shown in Table 15 below.

[0094] [Table 15]

Ceramic name Product name Composition Shape Manufacturer name Density (g / cm3) Particle size (Mm) Trial mixing amount (WtM) Maximum mixing amount (wt%) Spinel NSP-70 -200mesh MgO.AI203 fe-shaped ITOCHU CERATECH CORPORATION 3.27 75 20,30,40, x50 40 Aluminum titanate VCAT ΑΙ2ΤΪ05 Granular vacuum ceramics 3.7- -1.0 10,20,30,40, x50 40

X: No liquidity

s: precipitation

[0095] The aluminum titanate shown in Table 15 can be used in the production of a fluid having a mixing force of 10%, 20%, 30% and 40%. It was found that 20%, 30% and 40% can be used for production (see Table 15 and Figure 18). From this, it is considered that aluminum titanate and spinel can be manufactured if the mixing amount is 40% or less. In addition, it was confirmed that both of these ceramic materials were dispersed in the molten salt of potassium salt (see Fig. 15).

Aluminum titanate density 3. 7 g / cm ^3, the particle diameter is not less, the density of the spinel is ^{^3.} 27g / cm ^3, the particle size is ⁷⁵ / zm.

For the above ceramic materials, bending test pieces were prepared for each mixing amount as shown in Table 16 below, and the bending strength was determined.

[0096] [Table 16]

When aluminum titanate and spinel are used as ceramic materials in this way, as shown in Fig. 11, by setting the mixing amount to 20% or more, the transverse rupture strength is reduced to 8 MPa. It turned out to be larger.

Therefore, it can be said that, even if aluminum titanate or spinel is used as the ceramic material as described above, the same effect as when the first embodiment is adopted can be obtained.

[0098] (Eighth Embodiment)

The salt core according to the present invention is made of alumina (Al 2 O 3) having a granular shape as a ceramic material.

2 3 can be used. By mixing alumina with potassium salt, a bending strength as shown in FIG. 12 was obtained.

FIG. 12 is a graph showing the relationship between the mixed amount of alumina and the bending strength. The flexural strength shown in FIG. 12 was obtained by performing the experiment shown in the first embodiment using alumina as a ceramic material. The lines in FIG. 12 are approximation curves drawn using the least squares method.

The alumina used in the experiment was selected from the commercially available granular ones shown in Table 17 below.

[0099] [Table 17]

From the viewpoint of fluidity, it was found that alumina having a mixed amount of 20% 30% 35% (AL-45-1) in Table 17 can be used for production (see Fig. 18). This indicates that AL-45-1 can be manufactured if the mixing amount is 35% or less, and the others can be manufactured if the mixing amount is 30% or less. Conceivable.

It was also confirmed that these aluminas were dispersed in the molten salt of Shiridani potassium (see FIG. 15). These aluminas have a density of about 4 gZcm ³ and a particle size of 0.6 μm (AL-160SG), 1 m (AL-45-1), and 3-4 μm. m (A—42—1) and 40—50 μm (A—12).

With respect to the above-mentioned alumina, a bending test piece was prepared for each mixing amount as shown in Table 18 below, and the bending strength was determined.

[Table 18]

Composition Bending load Bending strength

Composition wt% N Pa

pure KCI 0 186.255 1.55

pure KCI 0 250.024 2.08

pure KCI 0 226.274 1.89

pure KCI 0 308.725 2.57

pure KCI 0 225.850 1.88

KCI + 20% AI203 AL-45-1 20 8.68

KC! + 30¾AI203 AL-45-1 30 1037.05 8.64

KCI + 35 I203 AL-45-1 35 1116 9.30

KCI + 35 I203 AL-45-1 35 1008.67 8.41 Composition Bending load Bending strength

Composition wt¾ N MPa

pure KCI 0 186.255 1.55

pure KCI 0 250.024 2.08

pure KCI 0 226.274 1.89

pure KCI 0 308.725 2.57

pure KCI 0 22 CD5.850 1.88

KCI + 20¾AI203 A-42-1 20 871.75 7.26

KCI + 20¾AIZO3 A-42-1 20 1432.5 11.94

KCI + 30¾AI203 A-42-1 30 2118.07 17.65

KCI + 30% AI2O3 A-42-1 30 1660.75 13.84 Composition Bending load Bending strength

Composition wt% N MPa

pure KCI 0 186.255 1.55

pure KCI 0 250.024 2.08

pure KCI 0 226.274 1.89

pure KCI 0 308.725 2.57

pure KCI 0 225.850 1.88

KCI + 20 AI203 A-12 20 1093.52 9.

KCI + 20¾AI203 A-12 20 972.4 8.10

KCI + 30 I203 A-12 30 1456 12.13

KCI + 30 I2O3 A-12 '30 1540 12.83 Composition Bending load Bending strength

Composition wt% N MPa

pure KCI 0 186.255 1.55

pure KCI 0 250.024 2.08

pure KCI 0 226.274 1.89

pure KCI 0 308.725 2.57

pure KCI 0 225.850 1.88

KC1 + 20¾AI203 AL-160SG-3 20 973.75 8.11

KCI + 20 I203 AL-160SG-3 20 986.25 8.22

KCI + 30¾AI203 AL-160SG-3 30 1166.34 9.72

KCI + 30¾AI203 AL-160SG-3 30 1183.75 9.86 When alumina is used as a ceramic material in this way, as shown in Fig. 12, It was found that by setting the mixing amount to 20% or more, the transverse rupture strength was higher than 8 MPa.Therefore, even if alumina was used as the ceramic material as described above, the same as when the first embodiment was adopted. It can be said that it has an effect.

[0103] FIGS. 13 and 14 show the relationship between the mixing amount of all the ceramic materials and the bending strength shown in the first to eighth embodiments described above. As can be seen from these figures, among the above-mentioned ceramic materials, the one capable of forming the salt core having the highest bending strength was aluminum nitride.

Among the above ceramic materials, the material with the lowest material unit price is synthetic mullite, and the material with the smallest material amount (mixing amount) is aluminum borate. In other words, by using synthetic mullite or aluminum borate, it is possible to produce a salt core having high strength without reducing production costs.

[0104] It is considered that a salt core having excellent formability and high strength could be formed by using the ceramic material shown in the first to eighth embodiments for the following reasons. This is because the molten metal obtained by mixing these ceramic materials with potassium salt has fluidity, and the density of these ceramic materials is the density of potassium salt in the molten state (1.57 g / cm ³ ). This is a value that is more moderately large, and is considered to be a force capable of suppressing the crack growth inside the salt by dispersing these ceramic materials widely and uniformly in the molten potassium salt.

[0105] That is, the structure is possible because of the "fluidity", and sufficient strength is obtained because it is "dispersed". Of these factors, the influence on the “fluidity” is mainly the amount of the ceramic material mixed (wt%), and the “dispersion” is affected by the density. For this reason, even if the ceramic material is different from that shown in the first to eighth embodiments, the density is close to each of the above ceramic materials, and a molten metal having fluidity is formed. It is considered that a salt core having the same strength as that described in the above embodiment can be formed.

[0106] In order to investigate the force of the ceramic material being well dispersed in the molten salt material, according to an experiment conducted by the inventors on the mixing conditions of potassium salt and the ceramic material, FIG. As shown in Fig. 15, the ceramic material dispersed in the molten potassium salt has a minimum density of more than 2.28 g / cm ³ (boron nitride) and a maximum of 4 g / cm ³ (alumina). It was found that the maximum value of the particle size was about 150 μm.

[0107] This is because the solidification time of the molten metal and the precipitation rate of the ceramic material are closely related to dispersion. The theoretical equation for the precipitation rate is

(ρ ο- ρ ₅ ) ά ² 18 μ---'Equation 2

It is. Where V is precipitated speed [MZS], g is the gravitational acceleration 9.80 [MZS ^2], pc is the density of the Seramitsu task materials [GZcm ^3], ps is the density of the salt material in the molten state [GZcm ^3], d is The particle size [m] and μ of the ceramic material are the viscosity coefficient [Pa · s] of the salt material.

According to Equation 2, the precipitation velocity V is proportional to the first power of the density difference between the ceramic material and the molten salt material, and is proportional to the square of the particle size. From this, it is considered that when the particle size is larger than 150 m, the precipitation speed becomes extremely high and the ceramic material cannot be dispersed well. On the other hand, with respect to the density of the ceramic material, small influence amount for precipitation rate in comparison with the influence of the particle size, soヽof performing this experiment, greater than 4g / cm ^3, it may be a ceramic box material dispersion It can be guessed that it is possible.

[0109] Further, it was found that the relationship between the mixing amount of each ceramic material and the fluidity was as shown in Figs. Figures 16 to 18 were obtained by experiments in which a ceramic material and potassium salt were placed in a Tamman tube, melted at 800 ° C, stirred sufficiently, and then turned back down. In this experiment, the material flowing out of the molten metal Tamman tube was designated as "fluid", and otherwise, it was designated "no fluid".

[0110] Therefore, the density is larger than 2.2 gZcm ³ (= the density of boron nitride) and is 4 gZcm ³ or less and Z and the particle size is about 150 m or less. As long as it is a ceramic material that can be used, a salt core having a strength that can be used in the die casting method can be formed.

(Ninth Embodiment)

The salt core according to the present invention is made of aluminum borate whisker (9A1) as a ceramic material.

2

O.2B O), silicon nitride force (SiN), silicon carbide force (SiC), potassium titanate

3 2 3 3 4

Moisture power (K O. 6TiO), potassium 8 titanate whisker (K O. 8TiO) and oxide Lead-force (ZnO) can be used.

These ceramic wiping powers include those shown in Table 19 below.

[Table 19]

Ceramic name Product name Composition Shape Manufacturer name Density (g / cm3) Particle size (μηη) Particle size (μιη) Trial mixing amount (wt%) Maximum mixing amount (wt%) Aluminum borate Albolex M20 9AI203.2B203 Whisker Shikoku Chemicals Industrial Co., Ltd. 2.93 10-30 0.5-1.0 10,15,18.67, x20 15 Silicon nitride SNW # 1-S Si3N4 alpha Whisker Tatejo Chemical Co., Ltd. 3.18 5-200 0.1-1.6 5,7, x8 7 Carbonized Silicon SCW # 1-0.8 SiC Beta Whisker Tateho Chemical Co., Ltd. 3.18 5-200 0.05-1.5 5,7, x8, x10, x15 7

6 Potassium titanate Tismo N Κ20.6ΤΪ02 Whisker Otsuka Chemical Co., Ltd. (3.4-3.6) 3.58 10-20 0.3-0.6 5,7, x8, x10 7

8 Potassium titanate ismo D K20.8 cho i02 Whisker Otsuka Chemical Co., Ltd. (3.4-3.6) 3.58 10-20 0.3-0.6 5, 7, x8, x10 7 Zinc oxide WZ-0501 ZnO Whisker Matsushita Amtech Co., Ltd. 5.78 2-50 0.2-3.0 5,10,15, x16, x18, x20 15 x: No liquidity

s: precipitation

[0113] As shown in Table 19, it was found that aluminum borate whiskers (product name: Albolex M20) can be used for production with a mixing force of 10%, 15% and 18.67% in terms of fluidity. (See Figure 24). For these reasons, it is considered that aluminum borate whiskers can be manufactured if the mixing amount is 18.67% or less.

Silicon nitride power (product name SNW # 1—S), silicon carbide power (product name SCW # 1-0.8), potassium 6 titanate whisker (product name Tismo N), and 8 titanic acid It was found that potassium potassium (product name: Tismo D) with a mixed amount of 5% and 7% can be used for production (see Fig. 24). From this, it is considered that these whiskers can be manufactured if the mixing amount is 7% or less.

It was found that Zinc whiskers (product name WZ-0501) having a mixing amount of 5%, 10% and 15% can be used for production (see FIG. 24). From this, it is considered that zinc oxide whiskers can be manufactured if the mixing amount is 15% or less.

Of these strengths, by mixing aluminum borate whiskers with potassium chloride, the transverse rupture strength as shown in FIG. 19 was obtained.

FIG. 19 is a graph showing the relationship between the mixing amount of the aluminum borate whis force and the bending strength. The transverse rupture strength shown in FIG. 19 was obtained by performing the experiment shown in the first embodiment using aluminum borate whiskers as a ceramic material. Note that the line in FIG. 19 is an approximate curve drawn using the least squares method. In conducting this experiment, as shown in Table 20 below, a bending test piece was prepared for each mixing amount, and the bending strength was determined.

[0115] [Table 20]

Composition Bending load Bending strength

Composition wt¾ N MPa

pure KCI 0 186.255 1.55

pure KCI 0 250.024 2.08

pure KCI 0 226.274 1.89

pure KCI 0 308.725 2.57

pure KCI 0 225.850 1.88

KCI + 10! ¾Arbo M20 10 2485.750 20.71

KCI + 10! ¾Arbo M20 10 2466.75 20.56

KCI + 10! ¾7 Report M20 10 2488.75 20.74

KCI + 10% Arbo M20 10 2832.25 23.60

1 <(： 1 + 10¾; arbo << 20 10 2262.89 18.86

1 + 10! Palpo 1 «20 10 2758.00 22.98

KCI + 10¾7 Report M20 10 2624.75

1 +10! Alpo 1 «20 10 2155.35 17.96

1 <(; 1 +15!

KCI + 15S; Alpo M20 15 3722.75 31.02

1 +15! Valve 120 15 3763.50 31.36

KCI + 15¾7 Report M20 15 3973.75 33.11

KCI + 15% Arbo M20 15 3305.72 27.55

1 ((： 1 + 15¾; Arbo¾120 15 3783.02 31.53

KCI + 15% Arbo M20 15 34 11.75 28.43

KCI + 18.7% Arbo M20 18.7 4346.25 36.22

As shown in FIG. 19, when aluminum borate whiskers are used as a ceramic material, it was found that the bending strength becomes greater than 8 MPa if the mixing amount is 5% or more. Also, it was found that when the mixing amount was 18%, the transverse rupture strength was as high as 35 MPa. Therefore, even if aluminum borate whiskers are used as the ceramic material as described above, it can be said that the same effect as when the first embodiment is adopted can be obtained.

[0117] (Tenth embodiment)

By mixing a silicon nitride force or a silicon carbide whisker with potassium chloride, a transverse rupture strength as shown in FIG. 20 was obtained.

FIG. 20 is a graph showing the relationship between the mixed amount of the silicon nitride force and the mixed amount of the silicon carbide force and the bending strength. The transverse rupture strength shown in FIG. 20 was obtained by performing the experiment shown in the first embodiment using silicon nitride force or carbon carbide whisker as a ceramic material. Note that the line in FIG. 20 is an approximated curve drawn using the least squares method. In carrying out this experiment, as shown in Table 21 below, a bending test piece was prepared for each mixing amount, and the bending strength was determined. [0118] [Table 21]

[0119] As described above, when silicon nitride whisker or silicon carbide whisker is used as a ceramic material, as shown in Fig. 20, if the mixing amount is 7%, the transverse rupture strength is larger than 8MPa. It turns out.

Therefore, as described above, it can be said that the same effect as when the first embodiment is adopted can be obtained even if a silicon nitride force or a silicon carbide whisker is used as the ceramic material.

[0120] (Eleventh embodiment)

By mixing potassium hexatitanate force or potassium octa titanate whisker with potassium chloride, bending strength as shown in FIG. 21 was obtained.

FIG. 21 is a graph showing the relationship between the mixing amount of potassium titanate powder force and the mixing amount of potassium potassium titanate powder force and bending strength. The transverse rupture strength shown in FIG. 21 was obtained by performing the experiment shown in the first embodiment using potassium hexa titanate force or potassium octa titanate whisker as a ceramic material. Note that the line in FIG. 21 is an approximate curve drawn using the least squares method. Table 22 below shows the results of this experiment. [0121] [Table 22]

OAVu Ζ9 / vld0 sfc 6992

[0122] When potassium hexatitanate force or potassium octa titanate whisker is used as a ceramic material in this way, as shown in Fig. 21, if the mixing amount is 7%, the bending strength is larger than ^ MPa. It turned out to be.

Therefore, as described above, even if potassium hexatitanate power or potassium octa titanate whisker is used as the ceramic material, it can be said that the same effect as when the first embodiment is adopted can be obtained.

(Twelfth Embodiment)

The bending strength as shown in FIG. 22 was obtained by mixing Zinc whisker with potassium salt.

FIG. 22 is a graph showing the relationship between the mixing amount of the Zi-Dani zinc wiping force and the bending strength. The bending strength shown in FIG. 22 was obtained by performing the experiment shown in the first embodiment using zinc oxide whiskers as a ceramic material. Note that the line in FIG. 22 is an approximate curve drawn using the least squares method. In carrying out this experiment, as shown in Table 23 below, bending test pieces were prepared for each mixing amount, and the bending strength was determined.

[0124] [Table 23]

In the case of using the Zi-Dai zinc whisker as a ceramic material in this way, as shown in Fig. 22, by setting the mixing amount to 15%, a salt core having high bending strength can be formed. Monkey

Therefore, it can be said that the same effect as when the first embodiment is adopted can be obtained even when the Zidani zinc whisker is used as the ceramic material as described above. FIG. 23 shows the relationship between the mixing amount of all the forces and the bending strength shown in the ninth to twelfth embodiments described above. As can be seen from FIG. 23, the aluminum borate wiping force capable of forming a salt core having the highest bending strength among the above-mentioned die forces. Further, it was found that the relationship between the mixing amount of each ceramic sheet force and the fluidity was as shown in FIG. In FIG. 24, the ceramics power and potassium salt were placed in a Tamman tube and melted at 800 ° C., then sufficiently stirred, and the tube was turned back downward. In this experiment, those that also flowed out of the molten metal S-Tamman tube were rated “fluid” and those that did not flow were “fluid”.

[0127] In each of the above-described embodiments, an example is described in which potassium salt is used as the salt material. However, in addition to potassium salt, the salt material may be sodium salt, potassium or sodium salt. Any one of bromide, carbonate, and sulfate can be used. As sodium salty sardine, sodium salty sardine (NaCl) can be used. As potassium or sodium bromide, potassium bromide (KBr) or sodium bromide (NaBr) can be used. As carbonates, sodium carbonate (Na CO) and potassium carbonate (K CO)

2 3 2 3 can be used. Potassium sulfate (K so) can be used as sulfate

twenty four

(Thirteenth Embodiment)

By using potassium bromide or sodium bromide as a salt material and mixing aluminum borate whiskers with these salt materials, a bending strength as shown in FIG. 25 was obtained.

FIG. 25 is a graph showing the relationship between the mixing amount of potassium bromide or sodium bromide and aluminum borate wiping force and the bending strength. The drawing also shows the transverse rupture strength when aluminum borate-moisture force is mixed with different salt materials. As these different salt materials, potassium salt and sodium salt were used. FIG. 25 shows the density p of each salt material in the solid state. Density p in the solid state of the potassium bromide is 2. 75g / cm ^3, a density P of the solid state sodium bromide is 3. 21g / cm ^3, the density in the solid state of Shioi匕potassium p Is 1.98 g / cm ³ and the density p in the solid state of sodium salt is 2.17 g / cm ³ c The bending strength shown in FIG. 25 was obtained by performing the experiment shown in the first embodiment using aluminum borate whiskers as a ceramic material. Note that the line in FIG. 25 is an approximate curve drawn using the least squares method. In conducting this experiment, bending test pieces were prepared for each mixing amount as shown in Tables 24 to 27 below, and bending strength was determined. Table 24 below shows the transverse rupture strength when aluminum borate is mixed with potassium bromide, and Table 25 shows the transverse rupture strength when aluminum borate is mixed with sodium bromide.

[0130] Table 26 shows the transverse rupture strength when aluminum borate was mixed with potassium salt. Table 26 shows the results of two experiments in which the mixing amount of aluminum borate whissing force and the mixing amount of aluminum borate whissing force are 3 wt% in Table 20. is there. Table 27 shows the transverse rupture strength when aluminum borate was mixed with sodium chloride.

The aluminum borate whiskers used in adopting this embodiment are the same as those described in the ninth embodiment (see FIG. 19 and Table 19).

[0131] [Table 24]

[Table 25] Composition Bending load Bending strength

Composition wt% N MPa

NaBr 0 227.20 1.89

NaBr + 3% Alpo M20 3 12 10.75 10.09

NaBr + 3% Alpo M20 3 1424.50 1 1.87

NaBr + 3% Alpo M20 3 1527.07 12.73

NaBr + 3% Alpo M20 3 2041.42 17.01

NaBr + 5% Arbo M20 5 2098.85 17.49

NaBr + 8% Alpo M20 8 2531.25 21.09

NaBr + 10% Arbo M20 10 2554.40 21.29 [0133] [Table 26]

[Table 13]

When aluminum borate whiskers are mixed with potassium bromide or sodium bromide, as shown in FIG. 25, if the mixing power is ¾wt% or more, the transverse rupture strength becomes larger than 8 MPa. It turns out. In addition, in FIG. 25, it can be seen that a salt core having high bending strength can be formed by mixing aluminum borate with sodium salt sodium.

Therefore, potassium bromide or sodium bromide is used as the salt material as described above. Thus, it can be said that the same effect as when the first embodiment is adopted can be obtained.

[0136] Further, as described above, in addition to using a single salty salt, bromide or salt as described above, a potassium salty salt or a sodium salty salt, a potassium or sodium carbonate or Mixed salts with sulfates can be used. For example, a mixed salt of potassium salt and sodium carbonate, a mixed salt of sodium salt of sodium and sodium carbonate, a mixed salt of sodium salt of sodium chloride and carbonated lithium, or a mixed salt of potassium salt and potassium sulfate And a mixed salt thereof.

[0137] By making the salt material a mixed salt in this way, a salt core having a low melting point can be formed, as is well known in the art. For this reason, the temperature at the time of manufacturing the salt core can be lowered, and accordingly, the power consumption of the manufacturing apparatus can be reduced, and the cost for manufacturing the salt core can be reduced. . In addition, salt cores formed by the above four kinds of mixed salts are less likely to cause wrinkles on the surface of the manufactured core.

Industrial applicability

[0138] The manufacturing core according to the present invention is useful for a die-casting mold.

Claims

The scope of the claims

[1] A manufacturing core obtained by forming a mixed material of a salt material and a ceramic material by manufacturing, wherein the salt material includes potassium or sodium chloride, bromide, carbonate, or sulfate. of be of any one, the ceramic material is铸造core for artificially synthesized density 2. is one that exhibits a large 4GZcm ³ following granular than 2gZcm ^3.

[2] In铸造for core according to claim 1, ceramic material has a density of 2. 79g / cm ³ - 3.铸造core for a composite mullite 15 g / cm ^3.

3. The manufacturing core according to claim 1, wherein the ceramic material is aluminum borate having a density of 2.93 gZcm ³ .

[4] A manufacturing core obtained by manufacturing a mixed material of a salt material and a ceramic material, wherein the salt material is made of potassium or sodium chloride, bromide, carbonate, or sulfate. Any one of the above, wherein the ceramic material has an artificially synthesized particle diameter of 150 μm or less and has a granular shape.

[5] A production core formed by production of a mixed material of a salt material and a ceramic material, wherein the salt material is made of potassium or sodium chloride, bromide, carbonate, or sulfate. The ceramic material is any one of synthetic mullite, aluminum borate, boron carbide, silicon nitride, silicon carbide, aluminum nitride, aluminum titanate, cordierite, and alumina. A core for production.

[6] A manufacturing core obtained by forming a mixed material of a salt material and a ceramic material by manufacturing, wherein the salt material is formed of potassium or sodium chloride, bromide, carbonate, or sulfate. And the ceramic material is any one of aluminum borate, silicon nitride, silicon carbide, potassium hexatitanate, potassium dititanate, and zinc oxide.铸 Building core.

[7] The structural core according to claim 6, wherein the ceramic material is aluminum borate wisdom.

[8] A manufacturing core obtained by forming a mixed material of a salt material and a ceramic material by manufacturing, wherein the salt material is potassium or sodium with respect to potassium or sodium chloride. Is a mixed salt obtained by adding sodium carbonate or sulfate, and the ceramic material is

, Artificially synthesized density 2. 2 g / cm ³ greater than 4g / cm ³ is also of a is铸造for core exhibits the following granular.

In铸造for core according to claim 8, the ceramic material has a density of 2. 79g / cm ³ - 3.铸造core for a composite mullite 15 g / cm ^3.

9. The manufacturing core according to claim 8, wherein the ceramic material is aluminum borate having a density of 2.93 g / cm ³ .

A forging core obtained by forming a mixed material of a salt material and a ceramic material by forging, wherein the salt material is potassium or sodium carbonate or sulfate against potassium or sodium chloride. Wherein the ceramic material has an artificially synthesized particle diameter of 150 m or less and has a granular shape. A forging core obtained by forming a mixed material of a salt material and a ceramic material by forging, wherein the salt material is potassium or sodium carbonate or sulfate against potassium or sodium chloride. Wherein the ceramic material is any one of synthetic mullite, aluminum borate, boron carbide, silicon nitride, silicon carbide, aluminum nitride, aluminum titanate, cordierite, and alumina. Manufacturing cores that are granular.

A forging core obtained by forming a mixed material of a salt material and a ceramic material by forging, wherein the salt material is potassium or sodium carbonate or sulfate against potassium or sodium chloride. And the ceramic material is a whisker of one of aluminum borate, silicon nitride, silicon carbide, potassium hexatitanate, lithium titanate, and zinc oxide.铸 Building core.

14. The manufacturing core according to claim 13, wherein the ceramic material is aluminum borate wisdom.

Claim 18. The manufacturing core according to any one of Claims 14 to 14, wherein the mixed salt is formed by potassium chloride and sodium carbonate.