JPH08276246A - Shell molding machine and casting method using it - Google Patents

Abstract

PURPOSE: To provide a shell molding machine easy in shell molding which is at least double-structure, and capable of mass production of a sleeve provided with a number of projections on its undercut part. CONSTITUTION: A metal pattern to mold shell consists of an upper pattern and a lower pattern, a plurality of inserts 12A, 12B, 12C for making goods of half-split cylindrical shape are arranged on the lower pattern, and a spiny insert inserting recessed part 16 is formed at the undercut part formed by the semi-circular surfaces 23a of the adjacent inserts 12A, 12B, 12C for making goods. A spiny insert 22 provided with the surface of the same curvature as that of the semi-circular surface 23a of the inserts 12A, 12B, 12C for making goods and provided with a number of projections on this surface is depressably provided on the spiny insert inserting recessed part 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shell molding apparatus for molding a shell mold for casting a cylindrical product such as a sleeve of a cylinder block, and a casting method using the shell mold.

[0002]

2. Description of the Related Art Generally, a cylinder block 80 is shown in FIG.
As shown in FIG. 0, a cylindrical sleeve 81 is manufactured by casting, and the sleeve 81 is placed in a cavity of a die casting mold.
A plurality of aluminum alloys are housed side by side, and a molten aluminum alloy is injected into the cavity by a die casting method.

In this case, a sleeve having a large number of projections on its surface is used in order to well bite the sleeve 81 into the aluminum alloy block body 82.
Such sleeves have been produced one by one in a cylindrical shape by casting using a sand mold made of green sand or hard sand.

[0004]

Since the sleeves having a large number of protrusions formed on the surface thereof are produced one by one in a cylindrical shape by casting using a sand mold of raw sand and time-hardening sand, it takes labor to produce them. However, there is a problem that it is inefficient and it is impossible to mass-produce two or more sleeves.

The present invention is intended to solve the above problems, and a first object thereof is to mass-produce a sleeve having at least two stations and having a large number of protrusions in its undercut portion. It is an object of the present invention to provide a shell-type molding apparatus that can easily perform shell-type molding.

A second object of the present invention is to provide a casting method using a shell mold which can reduce the number of steps as compared with the casting method using the insert core. .

[0007]

In order to achieve the above first object, a shell mold making apparatus according to the present invention comprises a mold for molding a shell mold consisting of an upper mold and a lower mold. The lower mold is arranged with a plurality of product inserts each having a half-cylindrical shape, and a spiny insert insertion recess is formed in an undercut portion formed by the arc-shaped surfaces of adjacent product inserts. It is characterized in that a spiny nest having a surface having the same curvature as the arcuate surface of the nest and having a large number of protrusions provided on the surface is provided so as to be retractable.

The upper mold may be constructed by forming a cavity in the upper mold main body, which has a plurality of continuous recesses facing the plurality of product inserts of the lower mold.

Further, there are provided spiny nest actuating means for retracting the spiny nest, upper die moving means for moving the upper die away from and contacting the lower die, and pushing up means for releasing the molded shell die. You may do it.

Further, the spiny nest actuating means comprises:
It may be configured to have a pull-out pin connected to the spiny nest, a slide block for operating the pull-out pin, and an operating cylinder for operating the slide block.

In order to achieve the above-mentioned second object, the casting method using the shell mold according to the present invention is such that a plurality of spiny nests are formed in the undercut portion of the inner surface of the shell mold by operating the spiny nests provided in the lower mold. After forming a large number of recesses of the reverse copy of the projection of the shell mold, after separating the mold of the shell type, set a plurality of bore cores, and join the mating face parts of the shell type of the half split shape to create a shell mold mold. It is characterized in that the shell mold is used for casting.

[0012]

In the shell type molding apparatus according to the present invention,
It is possible to easily manufacture a shell mold of a half-divided shape in which a large number of recessed portions of reverse projections of a large number of spiny nests are formed in the undercut portion of the inner surface thereof, without using a placing core. Therefore, by casting two half-shaped shell molds with the bore core inside,
It is possible to mass-produce a sleeve that is at least two in series and that has a large number of protrusions in its undercut portion.

Further, in the casting method using the shell mold according to the present invention, a step of molding a molding core having a large number of protrusions, and a molding method of this molding method, as compared with the casting method using the molding core. It is possible to eliminate the step of transporting the stored core and the step of setting the core in the main mold.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a side view showing a partial cross section of a shell-type molding apparatus according to the present invention, and FIG. 2 is a cross sectional view taken along line AA of FIG.
3 is a sectional view taken along the line BB of FIG. 2, and FIG. 4 is a sectional view of FIG.
It is sectional drawing which follows the C line.

The shell-type molding apparatus according to the present invention comprises a lower mold 1
And the upper mold 2 are roughly configured. The lower mold 1 is provided with a die base 4 fixedly mounted on a pedestal 3, and a lower mold heating plate body 5 is fixedly mounted on the die base 4, and the lower mold heat A product nesting structure 11 is attached to the plate body 5. The lower mold hot plate body 5 and the product nesting structure 11 constitute a lower mold body.

The lower hot plate body 5 has a hot plate block body 6 which is rectangular in plan view as shown in FIGS. 6 to 8. The hot plate block body 6 has an upper surface portion 6A. The left side (MS side) and 2 with the center as Sakai seen from the worker side P
Nested recessed group 7 in each row, 2 rows on the right side (MP side)
Is provided. These nesting mounting recess groups 7 are formed by arranging four nesting mounting recesses 8 at a predetermined interval in the front-rear direction when viewed from the operator side P. A plurality of sand removing holes 9 are formed in the bottom surface of these nesting mounting recesses 8, and these sand removing holes 9 are cut out to the lower surface portion 6B of the hot plate block body 6.

Further, in the hot plate block body 6, three pin insertion holes 10 are slanted (tilted forward) from the front side (worker side P) of the hot plate block body 6 toward the front three nesting mounting recesses 8. Further, three pin insertion holes 10 are formed obliquely (rearward) from the rear surface side toward the rear three nesting mounting recesses 8, and the left surface portion and the right surface portion of the hot plate block body 6 are also formed. A large number of heater insertion holes 60 are formed in each of them, and a heater 61 is inserted into these heater insertion holes 60 (see FIG. 1).

As shown in FIGS. 9 to 13, the product nesting structure 11 includes two rows of four product nesting groups 12, and these product nesting groups 12 have front product nests 12A and 12A, respectively. It has two intermediate product inserts 12B and a rear product insert 12C. The product nest 12A on the front side has a configuration in which a rectangular fitting portion 14 is formed in a lower portion of a nest body 13 having a semicircular cross section, and a flat mating surface portion 15 is formed in a rear portion of the nest body 13. In the rear portion of the surface of the main body 13, a rectangular spiny insert insertion recess 16 is formed in plan view. In addition, from the front surface of the fitting portion 14, the spiny nesting insertion concave portion 16 is formed.
Has a rod insertion hole 17 extending from the end face thereof to the fitting portion 14
A sand removing hole 18 is formed to extend to the lower surface of the.

The intermediate product insert 12B has a rectangular fitting portion 14 at the bottom of the insert main body 13 having a semicircular cross section.
Is formed, and flat mating surface portions 15 are formed on the front and rear portions of the nesting body 13, and rectangular spiny nesting insertion concave portions 16 having a rectangular shape in plan view are formed on the front and rear portions of the surface of the nesting body 13. There is. Further, a rod insertion hole portion 17 is formed from the front surface portion of the fitting portion 14 to the end surface of the rear side spiny nesting insertion concave portion 16, and the rear surface portion of the fitting portion 14 is located at the front side of the spiny nesting insertion concave portion 16.
A rod insertion hole portion 17 is formed so as to extend to the end surface of the. In addition, from the spiny nesting insertion concave portion 16 to the fitting portion 14
A sand removing hole 18 is formed to extend to the lower surface of the.

The product insert 12C on the rear side has a rectangular fitting portion 14 at the bottom of the insert main body 13 having a semicircular cross section.
To form a flat mating surface portion 15 on the front portion of the nesting body 13.
Is formed, and is a rectangular shape in the plan view of the front side portion of the surface of the nesting main body 13 in the shape of a rectangular spiny nesting insertion recess 16
Is formed. Further, a rod insertion hole portion 17 is formed from the rear surface portion of the fitting portion 14 to the end surface of the spiny nesting insertion concave portion 16, and a sand removing hole is formed from the spiny nesting insertion concave portion 16 to the lower surface portion of the fitting portion 14. 18 is formed.

Then, four sets of product nesting groups 12 are mounted in the four sets of nesting mounting recessed groups 7 of the lower hot plate member 5. That is, the product insert 12A on the front side is fixed by bolting after fitting the fitting portion 14 to the front insert mounting recess 8 of the nest mounting recess group 7, and the intermediate product insert 12B is similarly fixed. The insert nesting recess 8 in the middle of the insert nesting recess group 7 is mounted, and the rear product nest 12C is similarly mounted in the nest fitting recess 8 on the rear side of the nest fitting recess group 7.

In this case, adjacent product nests 12A, 1
2B and 12C are in contact with each other at a mating surface portion 15, and a spiny nesting insertion recess 16 is provided in an undercut portion R formed by the arc-shaped surfaces of adjacent product nests 12A, 12B and 12C. The sand removal holes 18 formed in these spiny nesting insertion recesses 16 communicate with the sand removal holes 9 provided in the lower mold hot plate body 5.

In addition, the rod insertion hole 17 of the front product insert 12A and the front rod insertion hole 17 of the two intermediate product inserts 12B are inserted into the lower die heat plate 5 by inserting the three front pins. The rod insertion hole 17 on the rear side of the product insert 12C and the two intermediate product inserts 12B, which communicates with the hole 10, is provided on the rear side 3 provided on the lower mold hot plate body 5.
It communicates with the pin insertion hole 10 of the book.

A spacer block 19 is interposed between the inner end faces of the product nests 12A, 12B and 12C of the two product nest groups 12 facing each other. These spacer blocks 19 are bolted to the lower mold. It is fixed to the heating plate 5. Also, product nests 12A, 12B, 12
At the outer end of C, left and right end pressing members 20 and 21 are provided by being fixed to the lower mold hot plate body 5 by bolts.

A spline nest 22 is inserted in the spline nest insertion recess 16 so as to be retractable. As shown in FIGS. 14 to 17, the spiny nest 22 has a nest body 23, and the surfaces of the nest body 23 are front, middle, and rear product nests 12A, 12B,
It is an arcuate surface 23a having the same curvature as the surface of 12C, and many projections 24 are formed on this arcuate surface 23a. Further, the nest body 23 is provided with two rods 25 so as to project downward, and an end portion of the rod 25 is formed as a screw portion 25a.

The rod 25 of the spiny nest 22 having the above-mentioned structure has the rod insertion hole 1
7 is inserted into the spiny nesting insertion concave portion 16 so as to be retractable.

The front and rear parts of the die base 4 are shown in FIG.
3, sliding block positioning arms 26 and 27 are fixedly installed at the left and right, and a cylinder holding member 28 is provided at an intermediate portion of the front and rear portions of the die base 4 as shown in FIG. , 29 are fixed. The left and right sliding block positioning arms 26 on the front side have a pair of support piece portions 30, and pin holes 31 are formed in these support piece portions 30. The front left and right sliding block positioning arms 26 position and hold the front sliding block 32A.

That is, this sliding block 32A is shown in FIG.
As shown in FIGS. 8 and 19, a block main body 33 having a rectangular cross section is provided, and pin sliding mechanism portions 34 are provided at both ends of the block main body 33. The pin sliding mechanism portion 34 has a hole portion 33 formed in the block body 33.
The guide bushes 35 and 36 are inserted into a and the guide bushes 35 and 36 are pressed by the bush pressers 37 and 38. Further, a pair of three pin insertion holes 39 are formed in parallel in the vertical direction on each of the two left and right positions on the block body 33. The pin insertion holes 39 are shown in FIG. As shown, the pin receiving member 40 is fixedly provided on the block body 33. This pin receiving member 4
A screw hole 41 is formed at 0 so as to face the end face portion of the pin insertion hole 39.

In the sliding block 32A constructed as described above, the guide bushes 35 and 36 of the pin sliding mechanism portion 33 can slide on the sliding pin 42 supported by the pair of supporting piece portions 30. It is held by the left and right sliding block positioning arms 26 on the front side.

As shown in FIG. 5, the pull-out pin 43 has a screw hole 43a at its front end surface and a collar-like portion 43b at its rear end. The extraction pin 43 is inserted into the pin insertion hole 39 of the sliding block 32,
These pull-out pins 43 are inserted into the pin insertion holes 10, and the threaded portions 25a of the rods 25 of the spiny insert 22 are screwed into the screw holes 43a of the pull-out pins 43. Nesting 22
Is joined to.

Further, the screw hole 41 of the pin receiving member 40
The adjusting bolts 44 are screwed into the end of the adjusting bolts 44 and between the end faces of the adjusting bolts 44 and the end faces of the collar-like portions 43b of the extracting pins 43 in order to absorb the length displacement due to the thermal expansion of the extracting pins 43. Gap t is formed. And
An operating cylinder 45A is attached to the front cylinder holding member 28, and a piston rod 46A of the operating cylinder 45A is fixed to the central portion of the sliding block 32A. The operating cylinder 45A, the sliding block 32A, and the pull-out pin 43 constitute one spiny nesting operating means.

The rear sliding block 32B has the same structure as the front sliding block 32A, and the rear sliding block 32B is the same as the front sliding block 32A in the left and right rear blocks. The sliding block positioning arm 27 is positioned and held, and withdrawal pins 43 are inserted into the pin insertion holes 39 of the sliding block 32B. These withdrawal pins 43 are inserted into the pin insertion holes 10. The threaded portion 25a of the rod 25 of the spiny insert 22 is screwed into the screw hole 43 of the draw-out pin 43, and the draw-out pin 43 is connected to the spiny insert 22.

An operating cylinder 45B is attached to the rear cylinder holding member 28, and the piston rod 46B of this operating cylinder 45B is mounted on the sliding block 3a.
It is fixed to the center of 2B. The operating cylinder 45B, the sliding block 32B, and the pull-out pin 43 constitute the other spiny nesting operating means.

Further, as shown in FIG. 2, the pedestal 3, the die base 4 and the lower mold hot plate body 5 are provided with eject pin holes 46 at a plurality of positions. An eject pin 47 is inserted in 46,
These eject pins 47 are connected to each other and are moved up and down by an eject raising / lowering operation mechanism section (not shown), and these constitute push-up means.

The upper mold 2 has an upper mold body 48,
As shown in FIGS. 22 to 24, the upper mold body 48 has a cavity 50 formed on the mold matching surface 49 side, and the cavity 50 forms the product nest 12A of the lower mold 1,
A plurality of recessed portions 51 facing 12B and 12C are formed continuously, and a gate 52 communicating with each recessed portion 51 is provided in the upper mold body 48. Also, the upper mold body 48
Has a heater insertion hole 6 that goes from the front to the rear.
2 are formed in large numbers, and heaters 63 are inserted into these heater insertion holes 62. Also, the upper mold 2 is
It is moved up and down by an up-and-down actuating mechanism (not shown) which is an upper die moving means.

Next, a description will be given of a shell mold making by the shell mold making apparatus constructed as described above and a casting method using the shell mold.

In the lower mold 2, the working cylinder 4
5A and 45B are extended to operate the sliding block 32.
By moving (advancing) A and 32B, the pull-out pin 43 is moved, and the end surface 43F of the pull-out pin 43 is brought into contact with the step portion 17C of the rod insertion hole 17. Therefore, the spine nest 22 coupled to the pull-out pin 43 advances, and the arcuate surface 23a of the spine nest 22 extends to the front, middle, and rear product nests 12A, 1A.
This arcuate surface 23a coincides with the surfaces of 2B and 12C.
A large number of protrusions 24 of

Next, the upper die 2 is lowered by the operation of the elevating and lowering mechanism, and the die matching surface 49 of the upper die body 48.
Is aligned with the mating surface 65 of the lower mold body 64, and the product insert 12A of the lower mold 1 is inserted into the concave portion 51 of the cavity 50.
12B and 12C are inserted, and a space H in the shape of a sand mold to be molded is formed between them.

Next, shell sand (silica sand plus thermosetting polymer material) is blown into the space H from the plurality of gates 52 provided in the upper mold body 48.

Next, the heaters 61 and 63 provided on the upper and lower molds 1 and 2 are energized to raise the temperature to about 350 ° C. and the lower mold body 6
4 and product nests 12A, 12B, 12C are heated.
This heating cures the shell sand and molds the shell mold 70.

Next, the energization of the heaters 61 and 63 is stopped, the upper die 2 is raised by the operation of the elevating and lowering mechanism, and the upper die 2 is separated from the lower die 1. In this state,
A shell mold 70 is attached to the product inserts 12A, 12B, 12C side of the lower mold 1.

Next, in the lower mold 2, the actuating cylinders 45A and 45B are contracted to retract the sliding blocks 32A and 32B, thereby retracting the pull-out pin 43 and retracting the spiny nest 22. Then, the arcuate surface 23a is pulled in from the surfaces of the front, middle, and rear product nests 12A, 12B, and 12C, and the large number of projections 24 provided on the arcuate surface 23a are released from the shell mold 70. In this case, when the length of the protrusion 24 is about 2 mm, the spiny nest 2
The retracted amount of 2 is about 5 mm.

Next, the eject raising / lowering operation mechanism operates to raise the eject pin 47 to raise the shell mold 70.
Is pushed up and the shell mold 70 is released. This shell mold 70 has a half-divided shape, and a large number of recesses of the reverse copy of the large number of protrusions 24 of the spiny insert 22 are formed in the undercut portion of the inner surface thereof.

Next, in the next step, as shown in FIG. 27, four bore cores 71 are set, and the mating face portions 70A of the shell mold 70 having a half-divided shape are bonded together with an adhesive to form a shell. A mold template is created.

After this shell mold mold is conveyed to the casting site, aluminum alloy is poured in the casting process to cast four sleeves W shown in FIG. A large number of protrusions 24 'are formed on the undercut sleeve R'of the sleeve W. Then, this sleeve W is cast into an aluminum alloy by a die casting method to form a cylinder block S shown in FIG.

FIG. 25 shows a flow chart of the molding of the above shell mold and the casting method using this shell mold. That is, in step S1 of this flowchart, the lower mold 1
By operating the spiny insert 22 included in the shell mold 70, a large number of recessed portions of the reverse projection of the multiple protrusions 24 of the spiny insert 22 are formed in the undercut portion of the inner surface of the shell mold 70.

In step S2, after releasing the shell mold 70, four bore cores 71 are set. Then, in step S3, the mating surface portion 70 of the shell mold 70 having a half-split shape is formed.
The shell mold is prepared by bonding the two members A together with an adhesive. Then, in step S4, the shell mold is transported to the casting place, and in step S5,
In the casting process, aluminum alloy is poured and four sleeves W are cast.

FIG. 26 is a flow chart of the casting method using the storage core. That is, in step S1 of this flow chart, a molding core having a large number of protrusions is molded, in step S2 this molding core is transported, and in step S3, the molding core is set in the main mold to form a shell. A large number of recesses, which are the reverse copy of a large number of protrusions, are formed in the undercut portion on the inner surface of the mold.

Then, in step S4, four bore cores are set after the mold release of the shell type. Then, in step S5, the mating surface portions of the shell mold having the half-divided shape are adhered together by an adhesive to form a shell mold template. Then, in step S6, the shell mold is transported to the casting site, and in step S7, the aluminum alloy is poured in the casting process to cast four sleeves W.

As described above, according to the molding of the shell mold shown in FIG. 25 and the casting method using this shell mold,
In comparison with the casting method using the storage core, the step of molding a storage core having a large number of protrusions (step S1), the step of transporting the molded storage core (step S2), The step of setting the core in the main mold (step S3) can be eliminated.

[0051]

As described in detail above, in the shell mold manufacturing apparatus according to the present invention, the mold for molding the shell mold is composed of an upper mold and a lower mold, and the lower mold is divided into half cylinders. A plurality of shaped product nests are arranged, and spiny nesting insertion recesses are formed in the undercut portions formed by the arc-shaped surfaces of adjacent product nests, and these spiny nesting insertion recesses have the same curvature as the arcuate surface of the product nest. By forming a spiny nest having a surface and having many projections on this surface so that the spiny nest can be retracted, a large number of recessed parts of the reverse copy of many projections of the spiny nest are formed in the undercut portion of the inner surface. A half-shell type shell can be easily manufactured without using a core.

Therefore, by casting two shell molds each having a half-divided shape with the bore core inside, at least two sleeves having a large number of protrusions at their undercut portions are mass-produced. be able to.

Further, in the casting method using the shell mold according to the present invention, a step of molding a molding core having a large number of projections, and a molding method of this molding method, as compared with the casting method using the molding core. It is possible to eliminate the step of transporting the stored core and the step of setting the core in the main mold.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view of a shell-type molding apparatus according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

3 is a cross-sectional view taken along the line BB of FIG.

4 is a cross-sectional view taken along the line CC of FIG.

5 is an enlarged view of a portion D in FIG.

FIG. 6 is a plan view of a lower hot plate body.

7 is a cross-sectional view taken along the line EE of FIG.

8 is a cross-sectional view taken along the line FF of FIG.

FIG. 9 is a plan view of a product nesting structure.

10 is a sectional view taken along the line GG in FIG.

11 is a partial cross-sectional view taken from the direction I in FIG.

FIG. 12 is a plan view of a single product nest.

FIG. 13 is a side view of a single product nest.

FIG. 14 is a plan view of a spiny nest.

FIG. 15 is a side view of the same spiny nest.

16 is a sectional view taken along the line JJ of FIG.

17 is a cross-sectional view taken along the line KK of FIG.

FIG. 18 (1) is a front view of a sliding block mechanism portion. (2) is a sectional view taken along line LL of (1).

FIG. 19 (1) is a front view of a sliding block.
(2) is a sectional view in which the same portion is omitted. (3) is (2)
FIG. 6 is a view from the direction M in FIG.

FIG. 20 is a plan view of the pin receiving member.

21 is a cross-sectional view taken along the line NN of FIG.

FIG. 22 is a plan view of the upper mold.

23 is a cross-sectional view taken along the line OO of FIG.

24 is a cross-sectional view taken along the line QQ of FIG.

FIG. 25 is a flow chart of a casting method using a shell mold according to the present invention.

FIG. 26 is a flow chart of a casting method using a storage core.

FIG. 27 is a plan view of a shell mold including a bore core and a half-shell type mold.

FIG. 28 is a perspective view of a quadruple sleeve.

FIG. 29 is a perspective view of a cylinder block.

FIG. 30 is a perspective view of a conventional cylinder block.

[Explanation of symbols]

 1 Lower Mold 2 Upper Mold 12A, 12B, 12C Product Nesting 16 Spiny Nesting Insertion Recess 22 Spiney Nesting 23a Circular Surface 24 Protrusion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taichi Yoshikawa 1907 Hirata-cho, Suzuka-shi, Mie Honda Motor Co., Ltd. Suzuka Works

Claims (5)

[Claims] 1. A mold for molding a shell mold is composed of an upper mold and a lower mold, and the lower mold has a plurality of cylindrical product inserts arranged in half, and the arc-shaped surfaces of the adjacent product inserts have an arc-shaped surface. The undercut portion to be formed is formed with spiny nesting insertion recesses, and these spiny nesting insertion recesses have a surface having the same curvature as the arcuate surface of the product nest, and a spiny nest having a large number of protrusions provided on this surface. A shell-type molding apparatus characterized in that it is provided so that it can appear and disappear. 2. The shell mold making apparatus according to claim 1, wherein the upper mold is formed by forming a cavity in the upper mold main body, the cavity having a plurality of concave portions facing the plurality of product inserts of the lower mold. . 3. A spiny nest actuating means for retracting the spiny nest, an upper die moving means for separating and contacting the upper die with respect to the lower die, and a push-up means for releasing a molded shell die. The shell molding apparatus according to claim 1 or 2. 4. The spiny nest operating means includes a withdrawal pin connected to the spiny nest, a slide block for operating the withdrawal pin, and an operating cylinder for operating the slide block. The shell-type molding apparatus according to claim 2 or 3. 5. The operation of the spiny nesting provided in the lower mold forms a large number of recessed portions of the projections of the spiny nest in the undercut portion of the inner surface of the shell mold, and after the mold separation of the shell mold, the bore core is removed. A casting method using a shell mold, characterized in that a plurality of sets are formed, the mating surface portions of the shell mold of the half-divided shape are joined together to create a shell mold mold, and the shell mold is used for casting. .