JPH0929386A - Shell mold and molding equipment for molding same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shell mold molding device capable of mass producing at least two-continuous sleeves, capable of suppressing a deformation due to the shrinkage of the solidification contraction of the molten metal, and easy in molding the shell mold. SOLUTION: A die to mold a shell mold is composed of an upper die 2 and a lower die 1, plural half-split cylindrical product nests 12A, 12B, 12C are arranged in the lower die 2, the product nests 12A, 12B, 12C are inserted in a recessed part of a cavity for the upper die 2, and the end part on a sub runner part side of a sleeve forming part is formed in the reverse shape to the deformation shape of a sleeve W due to the shrinkage of solidification of the molten metal.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Generally, a cylinder block 80 is shown in FIG.
As shown in FIG. 1, a cylindrical sleeve 81 is produced by casting, and the sleeve 81 is placed in the cavity of the 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 sleeve having a large number of protrusions formed on the surface thereof is manufactured in a cylindrical shape by casting using a sand mold made of raw sand or slag hard sand, a storage core is required. It is very laborious, inefficient, inefficient,
There is a problem that it is not possible to mass-produce two or more sleeves.

The present invention solves the above-mentioned problems. The first object of the present invention is that not only can at least two sleeves be mass-produced but also shrinkage due to solidification shrinkage of the molten metal can be achieved. It is an object of the present invention to provide a shell mold that can suppress deformation due to the above and can cast a sleeve without distortion.

The present invention solves the above-mentioned problems. A second object of the present invention is that not only can at least two sleeves be mass-produced but also solidification shrinkage of the molten metal can be achieved. It is an object of the present invention to provide a shell-type molding apparatus capable of suppressing the deformation due to shrinkage due to the above, and which can easily perform shell-type molding.

[0007]

In order to achieve the above-mentioned first object, a shell mold according to the invention of claim 1 has a plurality of sleeve molding portions connected in series, and at least one of these sleeve molding portions is formed. It is characterized in that the end portion of the sleeve molding portion on the side of the sub-runner portion has a shape opposite to the deformed shape of the sleeve due to contraction due to solidification shrinkage of the molten metal.

In order to achieve the above-mentioned first object, the shell mold according to the invention of claim 2 has a plurality of sleeve molding portions connected in series, and at least the sub-runner portion side of these sleeve molding portions is provided. The sleeve forming portion is shifted inwardly with respect to the reference line S ′ by an angle θ1 which is one half of the center point Q1 of the sleeve forming portion at a predetermined angle θ1, and the other half portion of the sleeve forming portion is formed from the center point Q of the sleeve forming portion. The axis line b'of the reference line S '
It is characterized in that it is offset outwardly by a predetermined angle θ2.

In order to achieve the above-mentioned second object, in the shell mold making apparatus according to the invention of claim 3, the mold for molding the shell mold comprises an upper mold and a lower mold, and the lower mold As for the mold, a plurality of half-shaped cylindrical product inserts are arranged, the product insert is inserted into the concave portion of the cavity of the upper mold, and the end of the sleeve forming part on the sub-runner part side is melted between them. It is characterized in that a shell-shaped space having a shape opposite to the deformed shape of the sleeve due to the contraction due to the solidification shrinkage is formed.

In order to achieve the above-mentioned second object, in the shell mold making apparatus according to the invention of claim 4, the mold for molding the shell mold comprises an upper mold and a lower mold, and the lower mold As for the mold, a plurality of half-shaped cylindrical product inserts are arranged, and an axial line a of a half portion closer to the lateral M / C center O1 from the center point Q of the end product insert is arranged on the vertical side M / C center O2.
Is shifted inward by a predetermined angle θ1 with respect to a reference line S parallel to the vertical axis S of the half part on the side opposite to the lateral M / C center O1 with respect to the center point Q of the end product nest. The sand mold to be molded between the M / C center O2 and the reference line S parallel to the reference line S is shifted outward by a predetermined angle θ2, and the product insert is inserted into the concave portion of the cavity of the upper mold. It is characterized in that a space having the shape of is formed.

[0011]

According to the shell mold of the present invention, at least two sleeves can be mass-produced by casting two half mold shell molds with the bore core inside. Moreover, in the shell type, the end portion of the sleeve molding portion on the side of the sub-runner portion is formed in a shape opposite to the deformed shape to suppress deformation due to shrinkage.

Further, according to the shell-type molding apparatus of the present invention, not only can at least two sleeves be mass-produced, but also a shell mold that suppresses deformation due to shrinkage due to solidification shrinkage of the molten metal can be molded.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 is a partial plan view of the shell type, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is a sectional view taken along the line BB of FIG. 2, and FIG. FIG. 5 is a plan view of the sleeve molding portion, and FIG. 5 is a side view of the sleeve molding portion.

As shown in FIG. 1, a shell mold M molded by a shell mold molding apparatus has a bore core 7 inside.
Four pieces 1 are set, and the sub-runner portion 73 and the four-sleeve sleeve forming portion 74, in which the sprue 72 is formed, are created by bonding the mating surface portions 70A of the half-divided shell mold 70 together with an adhesive. Is equipped with.

Aluminum alloy is poured into this shell mold mold M to cast four continuous sleeves W. The shell mold mold M has a cross section taken along the line AA and a line taken along the line BB. As shown, the sub-runner portion 72 is thicker than the quadruple sleeve forming portion 74 because the thickness of the poured molten metal is large, so that the shrinkage due to the solidification shrinkage of the molten metal becomes large. However, the shell mold M cannot be regulated because it is made of sand. For this reason, at the time of solidified finish, the end of the quadruple sleeve on the sub-runner portion 73 side shrinks better than the other end, and is deformed into a fan shape in a big way.

Therefore, in consideration of this phenomenon, in the shell mold (shell mold) according to the present invention, the end of the quadruple sleeve molding part 74 on the side of the sub-runner part 72 is defined as the deformed shape. The shape is reversed to suppress deformation due to shrinkage.

That is, as shown in FIGS. 4 and 5, the sleeve molding portion 74a of the quadruple sleeve molding portion 74 on the side of the sub-runner portion 72 has a half 7 above the center point Q1 thereof.
The axis a of 5A is displaced inward (to the right in FIG. 4) by a predetermined angle θ1 with respect to the reference line S ′, and the half portion 75B below the central point Q of the sleeve molding portion 74a.
The axis line b'of is shifted outward (to the left in FIG. 4) with respect to the reference line S'by a predetermined angle θ2.

The sleeve molding portion 74a is shown in FIG.
As shown in FIG. 7, the end portion side of the upper half portion 75A is inclined at the inclination angle α so as to be lower than the end portion side of the lower half portion 75B.

As described above, the quadruple sleeve molding portion 74 is formed.
By deforming the sleeve molding portion 74a on the side of the sub-runner portion 72 in advance, deformation due to shrinkage due to solidification shrinkage of the molten metal is suppressed.

A shell molding apparatus for molding the shell mold having the above construction will be described below. The shell-type molding apparatus is generally composed of a lower mold 1 and an upper mold 2. 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.

A plurality of insert mounting recesses 6 are provided on the upper surface of the lower hot plate member 5, and a plurality of sand removing holes 7 are formed on the bottom surface of these insert mounting recesses 6. There are these sand removal holes 7 in the lower surface of the lower hot plate member 5.

As shown in FIGS. 7 to 14, the product nesting structure 11 includes two rows of four product nesting groups 12, each of which has a front product nest 12A. It has two intermediate product inserts 12B and a rear product insert 12C.

The product insert 12A on the front side has a rectangular fitting portion 1 at the bottom of the insert body 13 having a semicircular cross section.
4 to form a flat mating surface portion 1 at the rear of the nesting body 13.
5 is formed, and the spiny nesting recess 1 having a rectangular shape in a plan view is formed in the rear portion of the surface of the nesting body 13.
6 are formed. 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 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.

The product nest 12A on the front side is shown in FIG.
2 and FIG. 13, lateral side M / C from the central point Q
The axis a of the half portion 40A near the center O1 is the vertical side M /
Inward of the reference line S parallel to the C center O2 (see FIG. 1).
2 (to the right in (1)) is deviated by a predetermined angle θ1, and the axis B of the half portion 40B on the side opposite to the lateral side M / C center O1 from the center point Q of the front product nest 12A is , A predetermined angle θ outward (to the left in (1) of FIG. 12) with respect to the reference line S parallel to the vertical M / C center O2.
It deviates to 2.

Further, the product nest 12A on the front side is shown in FIG.
As shown in, the end portion side of the lateral M / C center O1 is inclined at the inclination angle α so as to be lower than the end portion side opposite to the lateral M / C center O1.

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 intermediate product nest 12B is shown in FIG.
As shown in, the axis C is parallel to the reference line S parallel to the vertical M / C center O2.

Further, the rear product insert 12C 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.

The product nest 12C on the rear side is shown in FIG.
As shown in 4, the lateral M / C center O from the center point Q
The axis D of the half 41A closer to 1 is shifted inward (left in FIG. 14) by a predetermined angle θ3 with respect to the reference line S parallel to the vertical M / C center O2, and the rear side M / C center O1 on the vertical side from the center point Q of the product nest 12C
The axis E of the half portion 41B on the opposite side is offset from the reference line S parallel to the vertical M / C center O2 outward (to the right in FIG. 14) by a predetermined angle θ4.

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 the fitting portion 14 is fitted into the insert fitting recess 6 on the front side.
2B is similarly mounted in the intermediate nesting recess 6 and the rear product nest 12C is similarly mounted in the rear nesting recess 6.

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.

A spacer block 19 is interposed between the inner end surfaces of the product nests 12A, 12B and 12C of the two product nest groups 12 facing each other. The 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. These spiny nests 22 have an arcuate surface 22A as shown in FIG. 15 and FIG.
A large number of protrusions 22B are formed on 2A. Then, the spiny nest 22 is retracted from the spiny nest insertion recess 16 by the operation of the left and right spinee nest actuation mechanisms 23. The spiny nest actuating mechanism 23 includes an actuating cylinder 24, a sliding block 25 that is moved (advanced) by an extension operation of the actuating cylinder 24, and the slide block 25 is moved to move the spinee nest. It is composed of a pull-out pin 26 for projecting 22.

Further, as shown in FIG. 6, the pedestal 3, the die base 4 and the lower mold hot plate 5 are provided with eject pin holes 27 at a plurality of positions. The eject pin 28 is inserted into 27,
These eject pins 28 are connected to each other and are moved up and down by an eject elevating operation mechanism section (not shown).

As shown in FIG. 17, the upper mold 2 has a cavity 30 formed on the mold matching surface 29 side, and this cavity 30 is used as the product nest 12A, 12 of the lower mold 1.
A plurality of recessed portions 31 facing B and 12C are formed continuously, and the upper mold 2 is provided with a gate 32 communicating with each recessed portion 31. The upper mold 2 is moved up and down by an elevating operation mechanism (not shown) which is an upper mold moving means.

Next, the shell mold making by the shell mold making apparatus constructed as described above will be explained.

In the lower mold 2, the working cylinder 2
4 is extended to move (advance) the sliding block 25 to move the pull-out pin 26, and the spiny nest 22 connected to the pull-out pin 26 advances to form an arc shape. Product nests 12A, 12B, 12C with surface 22A on the front, middle and rear sides
A large number of protrusions 22B of the arc-shaped surface 22A project in conformity with the surface of the.

Next, by the operation of the elevating and lowering mechanism, the upper mold 2 is lowered, the mold matching surface 29 of the upper mold 2 is aligned with the mold matching surface 33 of the lower mold 2, and the concave portion 31 of the cavity 30 is formed.
The product nests 12A, 12B, 12C of the lower mold 1 are inserted into the space, and a space H in the shape of a sand mold to be molded is formed between them.

Next, shell sand (silica sand to which a thermosetting polymer material is added) is provided from a plurality of gates provided on the upper mold 2.
Is blown into the space H.

Next, the heaters 35 and 36 provided on the upper and lower molds 1 and 2 are energized to raise the temperature to about 350.degree.
And heating the product nests 12A, 12B, 12C. This heating cures the shell sand and molds the shell mold 70.

Next, the energization of the heaters 35 and 36 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 24A and 24B are contracted to retract the sliding blocks 25A and 25B, thereby retracting the pull-out pin 26 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 to push up the shell mold 70 and release the shell mold 70. This shell mold 70 has a half-divided shape, and a large number of recessed portions of the reverse projection of the large number of projections 22B 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. 18, four boring cores 71 are set, and the mating surface 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.

In this shell mold mold, the above-mentioned 4
As described above, in the sleeve molding portion 74a of the continuous sleeve molding portion 74 on the side of the sub-runner portion 72, the axis line a of the upper half portion 75A above the central point Q1 is located inside the reference line S '(in FIG. 4). The right half of the sleeve molding portion 74a is offset from the center point Q by a predetermined angle .theta.1, and the axis line R'of the lower half portion 75B is outward with respect to the reference line S '(left in FIG. 4). Is deviated by a predetermined angle θ2.

The sleeve molding portion 74a is shown in FIG.
As shown in FIG. 7, the end portion side of the upper half portion 75A is inclined at the inclination angle α so as to be lower than the end portion side of the lower half portion 75B.

After this shell mold mold is transported to the casting site, aluminum alloy is poured in the casting process to cast four sleeves W shown in FIG. The undercut sleeve R ′ of the sleeve W has a large number of protrusions 71.
Are formed. Then, the sleeve W is cast into an aluminum alloy by a die casting method to form a cylinder block V shown in FIG.

[0048]

As described in detail above, in the shell mold according to the invention of claim 1, a plurality of sleeve molding portions are provided in series, and at least the end of the sleeve molding portion on the sub-runner portion side of these sleeve molding portions. By making the shape of the part opposite to the deformed shape of the sleeve due to shrinkage due to solidification shrinkage of the molten metal, not only mass production of at least two sleeves but also suppression of deformation due to shrinkage due to solidification shrinkage of the molten metal It is possible to cast a sleeve without distortion.

In the shell mold according to the second aspect of the present invention, a plurality of sleeve molding portions are continuously provided, and at least the sleeve molding portion on the sub-runner portion side of these sleeve molding portions is located at one side from the center point Q1. Axis half of the half,
Shift inwardly at a predetermined angle θ1 with respect to the reference line S ′,
At least two sleeves can be mass-produced by shifting the axial line b ′ of the other half part from the central point Q of the sleeve molding part outwardly with respect to the reference line S ′ by a predetermined angle θ2. In addition, it is possible to suppress deformation due to shrinkage of the molten metal due to solidification shrinkage, and it is possible to cast a sleeve without distortion.

According to a third aspect of the present invention, there is provided a shell mold manufacturing apparatus, wherein a mold for molding the shell mold is composed of an upper mold and a lower mold, and the lower mold is a product insert of a half-divided cylindrical body. A plurality of the above, insert the product insert into the concave portion of the cavity of the upper mold, and between the two, the end shape of the sleeve molding part on the sub-runner side is the deformed shape of the sleeve due to shrinkage due to solidification shrinkage of the molten metal. By forming the shell-shaped space in the reverse shape, it is possible not only to mass produce at least two sleeves, but also to mold a shell type that suppresses deformation due to shrinkage due to solidification shrinkage of the molten metal. .

According to a fourth aspect of the present invention, there is provided a shell mold manufacturing apparatus, wherein a mold for molding the shell mold is composed of an upper mold and a lower mold, and the lower mold is a product insert having a half-divided cylindrical shape. A plurality of lines, and in the product nest on the end side, the axial line a of the half part closer to the lateral side M / C center O1 from the central point Q is set to the vertical side M /
It is displaced inward by a predetermined angle θ1 with respect to the reference line S parallel to the C center O2, and the axial line B of the half part on the side opposite to the lateral M / C center O1 from the center point Q of the product nest on the end side. , The vertical side M / C center O2 is displaced outward by a predetermined angle θ2 with respect to a reference line S, and the product insert is inserted into the recess of the cavity of the upper mold, and between the two,
By forming the space in the shape of the sand mold to be molded, not only can at least two sleeves be mass-produced, but also a shell mold that suppresses deformation due to shrinkage due to solidification shrinkage of the molten metal can be molded.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional plan view of a shell type 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.

FIG. 4 is a plan view of a sleeve molding portion on the sub-runner portion side.

FIG. 5 is a side view of the sleeve molding portion.

FIG. 6 is a sectional view of a shell-type molding apparatus according to the present invention.

FIG. 7 is a plan view of a product nest structure.

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

FIG. 9 is a sectional view taken along the line DD in FIG. 7;

FIG. 10 is a plan view of a single product nest.

FIG. 11 is an end side view of a single product nest.

FIG. 12 (1) is a plan view of a single product insert, which is a lower mold of the sleeve molding portion on the sub-runner portion side. (2) is E
It is an arrow view from the direction.

FIG. 13 is a side view of a single product insert, which is a lower mold of the sleeve molding portion on the sub-runner portion side.

FIG. 14 is a side view of a product insert unit, which is a lower mold of the sleeve molding portion on the side opposite to the sub-runner portion side.

FIG. 15 is a plan view of a spiny nest.

FIG. 16 is a side view of the same spiny nest.

FIG. 17 is a sectional view of the upper mold.

FIG. 18 is a plan view of a shell mold including a bore core and a half-shell type mold.

FIG. 19 is a perspective view of a quadruple sleeve.

FIG. 20 is a perspective view of a cylinder block.

FIG. 21 is a perspective view of a conventional cylinder block.

[Explanation of symbols]

 1 Lower mold 2 Upper mold 12A, 12B, 12C Product nesting 30 Cavity 31 Recessed portion 74 Sleeve molding portion W sleeve

Claims (4)

[Claims] 1. A plurality of sleeve molding portions are provided in series, and at least the end portion of the sleeve molding portion on the sub-runner portion side of these sleeve molding portions is opposite to the deformed shape of the sleeve due to shrinkage due to solidification shrinkage of the molten metal. Shell type characterized by being shaped. 2. A plurality of sleeve molding portions are provided in series, and at least the sleeve molding portion on the sub-runner portion side of these sleeve molding portions has an axis line a'one half of the central point Q1 and a reference line S. A predetermined angle θ1 inward with respect to
The shell type is characterized in that the axis line R ′ of the other half part is displaced outward from the center point Q of the sleeve molding part with respect to the reference line S ′ by a predetermined angle θ2. 3. A mold for molding a shell mold is composed of an upper mold and a lower mold, and the lower mold is lined with a plurality of product inserts each having a half-cylindrical shape and arranged in a concave portion of a cavity of the upper mold. By inserting the product insert, a shell-shaped space is formed between the two by forming the end of the sleeve forming part on the side of the sub-runner part into a shape opposite to the deformed shape of the sleeve due to shrinkage due to solidification shrinkage of the molten metal. A shell-type molding apparatus characterized in that 4. A mold for molding a shell mold is composed of an upper mold and a lower mold. The lower mold is provided with a plurality of cylindrical product inserts of a half-divided shape, and a center point of the product insert on the end side. The half axial line a closer to the horizontal M / C center O1 than Q is displaced inward by a predetermined angle θ1 with respect to the reference line S parallel to the vertical M / C center O2, and Central point Q
The half-axis B on the side opposite to the lateral M / C center O1 is displaced outward at a predetermined angle θ2 with respect to the reference line S parallel to the longitudinal M / C center O2, and A shell-type molding apparatus, wherein the product nest is inserted into a concave portion of a cavity, and a space having a shape of a sand mold to be molded is formed between them.