JP2020124735A - Cast, mold, and casting method - Google Patents

Abstract

To provide a cast comprising: a sprue; a runner; a feeder; a product part; and a neck part connected with the product part, a mold casting the cast, and a casting method using the mold, in which the cast is disposed with the feeder capable of exhibiting a feeder effect while suppressing the reduction of a casting yield even in a state where a spherical fundamental shape cannot be adopted as the fundamental shape of the feeder, the mold casts the cast, and the production method uses the mold.SOLUTION: A cast comprises: a sprue; a runner C2; a feeder C3; a product part C4; and a neck part C5 connected with the product part C4, in which the feeder C3 takes a fundamental shape having a sphericity of 0.91 to below 1.00 in a state where it cannot take a spherical fundamental shape by positional relation with at least one selected from the sprue, the runner C2, the product part C4 and the neck part C5.SELECTED DRAWING: Figure 3

Description

The present invention relates to a casting provided with a sprue, a runner, a feeder, a product portion, and a neck portion connected to the product portion, a mold for casting the casting, and a casting method using the mold.

In casting, a feeder is provided at an appropriate place connected to the product through the neck so that the molten metal is supplied from the feeder according to the solidification shrinkage of the melt of the product. Has been done. The neck part is sometimes called a weir, and the riser may be provided between the sprue or runner and this neck part, or the neck part may be located above the product part apart from the sprue or runner. It may be provided via. However, in any case, the ratio of the riser to the casting weight is usually 20 to 40%, and as a result, there is a problem that the casting yield represented by product part weight/casting weight is low. Therefore, the determination of the proper shape and size of the feeder is an important issue for improving the casting yield which influences the casting cost.

Therefore, it has been proposed to make the basic shape of the feeder into a spherical shape (see Patent Document 1, etc.). Certainly, the modulus (volume of riser/surface area of riser), which is a simple indicator of the efficiency of risers, is better in spherical shaped risers than in conventional column shaped risers. If they are large and have the same modulus, a spherical feeder is preferable because it can reduce the volume as compared with a cylindrical feeder.

Japanese Patent No. 5696321

However, due to the positional relationship with at least one of the sprue, runner, product part, and neck part, there is no space for arranging a spherical feeder having a volume necessary for obtaining the feeder effect, There are cases where it is not possible to adopt the spherical basic shape as the basic shape of the hot water. In particular, in the case of a plurality of product parts provided for one sprue, as the number of product parts increases, the restriction on the positional relationship tends to increase.

FIG. 1 is a view showing an eight-piece casting in which eight product parts are provided for one sprue. FIG. 1A is a plan view, and FIG. 1B is a side view with the product part omitted.

The casting C′ shown in FIG. 1(a) includes eight product parts C4′, one runner C2′, four feeders C3′, and a neck that connects the feeder C3′ and the product part C4′. A section C5' is provided. Further, a connecting portion C21' to the bottom of the sprue (not shown) is shown in the central portion in the extending direction of one runner C2' extending in the left-right direction in the drawing. All of the four feeders C3' shown in FIG. 1(a) are spherical in shape, and two product parts C4' are provided for one feeder C3'. Further, in FIG. 1B, a one-dot chain line is shown so as to pass through the center of the feeder C3' in the height direction. This alternate long and short dash line corresponds to the parting plane. The casting C'shown in FIG. 1(a) is cast by so-called side-insertion casting.

Further, in FIG. 1, a two-dot chain line larger than the feeder C3' is shown. The two-dot chain line represents the size (volume) of the feeder which is necessary for the feeder C3′ to obtain the feeder effect while maintaining the shape of a true sphere. It can be seen that it interferes with C4'. In particular, in the case of horizontal casting, the degree of freedom in arranging the product portion C4' and the feeder C3' is low, and it is often impossible to adopt a spherical basic shape as the basic shape of the feeder. .. As described above, it may be difficult to secure the modulus necessary for obtaining the feeder effect while maintaining the basic shape of the feeder as a spherical shape.

On the other hand, if the basic shape of the feeder is made to be a column shape that has been common in the past, it is possible to secure a space for arranging the feeder, but it is necessary to obtain the effect of the feeder. The volume of the molten metal increases, and the casting yield decreases markedly.

Depending on the shape of the product, it may be desired to raise the feeder height to obtain the feeder effect. If the space can be secured, it is conceivable to increase the diameter of the feeder in order to raise the feeder while maintaining the spherical basic shape. However, if the diameter of the feeder is increased too much to increase the feeder, the volume of the feeder is unnecessarily increased, and in this case as well, the casting yield is significantly reduced.

In view of the above circumstances, the present invention provides a casting having a feeder capable of exerting a feeder effect while suppressing a decrease in casting yield, a mold for casting the casting, and a casting method using the casting. With the goal.

The first casting that solves the above object is
With a sprue
A runner,
With a feeder
Product department,
A neck portion connected to the product portion,
The sphericity is 0.91 or more in a state where the riser cannot take a basic spherical shape due to the positional relationship with at least one of the sprue, the runner, the product portion, and the neck portion. It is characterized by having a basic shape of less than 0.000.

The state in which the spherical basic shape cannot be taken due to the positional relationship here means, for example, the state in which the spherical basic shape cannot be taken due to the shape, width, height, etc. of the product part. ..

The second casting that solves the above object is
With a feeder
With product section,
The casting is characterized in that the top of the feeder has a higher position than the upper end of the product portion and has a basic shape with a sphericity of 0.91 or more and less than 1.00.

Comparing spherical feeders with conventional cylindrical feeders, when the two have the same volume, the spherical feeder has a smaller surface area, that is, The heat dissipation surface is small and the heat retention is high. However, even if it is desired to adopt a spherical basic shape as the shape of the feeder, it may not be possible due to the above positional relationship. Alternatively, depending on the shape of the product, it may be desired to raise the feeder to obtain the feeder effect. In these cases, the present inventor has devised to determine the shape of the feeder by using an index such as “sphericity” represented by “surface area of true sphere having the same volume as feeder/surface area of feeder” It was As a general cylindrical feeder, a feeder having a height of 1.75 times the diameter is known. While increasing the volume (volume of feeder/surface area of feeder) to the same or less volume as that of this general cylindrical feeder, the heat retention as a feeder, in other words, the effect of feeder is improved. Found that it was necessary to make the basic shape of the riser not spherical but a spherical shape, and as described in detail later, it was found that the sphericity should be 0.91 or more.

The riser is used after being subjected to appropriate modification and modification of the basic shape so that it can be easily used as a mold or casting model. For example, an appropriate draft angle, corner R, corner R, etc. may be provided for the mold release property of the molding, or a conical hole or a V groove may be provided on the top of the feeder to induce shrinkage of the top of the feeder. A score is provided, or part of the shape of the feeder is cut off in relation to the product section, or a surplus is added. In some cases, a rod-shaped portion having a diameter or width smaller than the diameter or width of the feeder may be additionally provided on the basic shape of the feeder in order to apply the molten metal head (melt pressure). However, the basic shape of the feeder is clear from its shape. Therefore, the basic shape of the feeder in the above casting is also subjected to such appropriate modification and deformation.

The feeder may be provided between the sprue or the runner and the neck portion. Further, the feeder may be a so-called fried feeder.

The neck portion may be referred to as a weir. That is, the neck portion may be a weir that connects the feeder and the product portion, or may be a weir that connects the runner and the product portion.

Also, in the above casting,
The feeder may have a basic shape in which a columnar body is sandwiched from the height direction while the sphere is halved.

The sphere mentioned here is not limited to a true sphere, and may be, for example, an ellipsoid. Further, the columnar body is not limited to the one whose cross-sectional shape along the direction orthogonal to the height direction is a perfect circle. Further, the cylindrical body may have a shape provided with a draft.

Further, the feeder is a cylinder provided with a first hemisphere portion on the receiving side of the gate, a second hemisphere portion opposite to the first hemisphere portion, and between the first hemisphere portion and the second hemisphere portion. It may have a part.

Further, the product part may be provided below the top of the feeder, and the receiving port at the gate may be provided above the top of the feeder.

Also, in the above casting,
The feeder may be in a mode in which the cross-sectional shape along the direction orthogonal to the height direction is elliptical or rounded rectangular.

The rounded rectangle referred to here is a shape composed of two parallel lines of equal length and two semicircles, and is a shape often found in athletic fields (tracks).

According to this aspect, the cylindrical body has an elliptical or rounded rectangular cross-section along the direction orthogonal to the height direction.

Further, both the first hemisphere portion and the second hemisphere portion have an elliptical or rounded rectangular shape in cross section along the direction orthogonal to the height direction.

The longitudinal direction of the ellipse or the rounded rectangle is the direction extended by utilizing the empty space.

Further, the feeder may have a basic shape in which spherical portions obtained by dividing a spherical body are dispersed and arranged.

The first mold for solving the above object is
A spout forming space,
A runner formation space,
A feeder formation space,
Product part formation space,
A neck portion forming space connected to the product portion forming space,
A state in which the feeder formation space cannot have a spherical basic shape due to a positional relationship with at least one of the gate formation space, the runner formation space, the product portion formation space, and the neck portion formation space. In the item (1), the sphere has a basic shape of 0.91 or more and less than 1.00.

The second mold for solving the above-mentioned object is
A feeder formation space,
With a product part formation space,
A mold characterized in that the riser forming space has a top portion higher than an upper end of the product portion forming space and has a basic space shape with a sphericity of 0.91 or more and less than 1.00. ..

It may be the first mold, the second mold, the sand mold, or the mold. Further, the mold may be a cast iron mold or a non-ferrous metal mold such as an aluminum alloy.

Both the first mold and the second mold can be used for side-filling casting in which the relationship between the pouring direction and the direction of the parting plane is a right angle, and the relationship is parallel. It can also be used for vertical casting.

In the first mold or the second mold,
The riser forming space is a space for casting a riser of a basic shape in which a columnar body is sandwiched from the height direction while the sphere is halved, the first hemispherical space having a hemispherical shape on the upper side and the hemisphere on the lower side. -Shaped second hemisphere space, a space in which a columnar cylindrical space is provided between the first hemisphere space and the second hemisphere space,
A parting surface may be provided at a boundary between the cylindrical space and the second hemisphere space.

The product portion forming space is provided below the top of the feeder forming space, and the upper end of the sprue forming space is provided above the top of the feeder forming space. Is preferred.

Further, the feeder formation space may have a basic shape in which spaces of spherical portions obtained by dividing a spherical body are dispersed.

The casting method that solves the above object is
A first step of pouring molten metal into the mold,
A second step of taking out the casting from the mold in which the molten metal has been poured.

The castings taken out in the second step correspond to castings that solve the above object.

According to the present invention, it is possible to provide a casting in which a feeder capable of exerting a feeder effect while suppressing a decrease in casting yield is arranged, a mold for casting the casting, and a casting method using the mold. ..

It is a figure which shows the casting containing eight pieces which provided eight product parts with respect to one gate. It is a figure showing a casting corresponding to one embodiment of the present invention. It is a figure which shows the one feeder shown in FIG. 2, one product part, and the neck part which connects the feeder and the product part. It is sectional drawing of the casting mold for casting the casting shown in FIG. FIG. 8 is a view showing the area around a feeder for a casting in Example 2. FIG. 7 is a view showing the periphery of a cast metal feeder in Example 3; FIG. 8 is a view showing the periphery of a cast metal feeder in Example 4; It is a figure which shows the feeder around the casting in Example 5. It is a figure which shows the feeder periphery of the casting in Example 6. It is a figure which shows the feeder around a casting in a comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a diagram showing a casting corresponding to one embodiment of the present invention.

Similar to FIG. 1, FIG. 2 shows an eight-piece casting in which eight product parts are provided for one sprue, and FIG. 2(a) is a plan view. This plan view is a view as seen from the gate (see FIG. 4) side of the sprue (not shown).

The casting C shown in FIG. 2(a) is provided with eight product parts C4, one runner C2, four feeders C3, and a neck part C5 connecting the feeder C3 and the product part C4. There is. The neck portion C5 may be referred to as a weir. In addition, a connecting portion C21 with a sprue bottom (see FIG. 4) in a sprue (not shown) is shown at the central portion in the extending direction of one runner C2 extending in the left-right direction in the drawing.

As shown in FIG. 2A, a product portion C4 is provided with the feeder C3 interposed therebetween. That is, the two product portions C4 are connected to one feeder C3 from the positions facing each other through the neck portion C5 by 180°. The arrow shown in FIG. 2A is an arrow representing the direction connecting two product parts C4 provided for one feeder C3.

FIG. 2B is a side view. In this side view, originally, the product parts C4 should be shown respectively on the left side and the right side of the feeder C3, but the product part C4 is omitted in FIG. 2(b). Further, in FIG. 2B, a one-dot chain line is shown so as to pass through the center of the feeder C3 in the height direction. This alternate long and short dash line is a line representing the parting plane (the same applies to the drawings below). The casting C shown in FIG. 2(a) is cast by so-called side-filling casting, but may be cast by vertical-filling casting.

FIG. 3 is a diagram showing one feeder and one product portion shown in FIG. 2 and a neck portion connecting the feeder and the product portion. That is, FIG. 3 shows around the feeder, a front view is shown in FIG. 3B, and a plan view is shown in FIG. This plan view is also a view seen from the side of the sprue (not shown) (see FIG. 4). A right side view is shown in FIG.

The product portion C4 is a hat-shaped member having a through hole C42 formed in the upper surface C41, has a flange portion C43, and becomes thinner as it goes upward. In addition, one end of the neck portion C5 is connected to the flange portion C43.

The feeder C3 has a basic shape in which a columnar body having a height of 40 mm is sandwiched from the height direction while a sphere having a diameter of 80 mm is halved. That is, as shown in FIG. 3B, the first hemisphere portion C31, the second hemisphere portion C32, and the columnar portion C33 between the first hemisphere portion C31 and the second hemisphere portion C32. The first hemispherical portion C31 is a receiving side hemispherical portion of a gate (not shown), and the second hemispherical portion C32 is an opposite hemispherical portion. The maximum diameter of the first hemisphere portion C31 and the second hemisphere portion C32 is 80 mm, and the diameter of the columnar portion C33 is also 80 mm. Further, the height of the cylindrical portion C33 is 1/2 the diameter. The casting C is provided with a draft angle. The cylindrical portion C33 is located above the parting plane indicated by the alternate long and short dash line, and the diameter of the lower end of the cylindrical portion C33 is the largest when the draft is taken into consideration. This riser C3 is 40 mm higher than a true sphere having a diameter of 80 mm.

The sphere is not limited to a true sphere, and may be, for example, an ellipsoid. Further, the columnar portion C33 is not limited to the one whose cross-sectional shape along the direction orthogonal to the height direction is a perfect circle. For example, the cross-sectional shape may be elliptical or rounded-rectangular. The rounded rectangle referred to here is a shape that consists of two parallel lines of equal length and two semicircles, and is a common shape on athletic fields (tracks) (the same applies below).

The feeder C3 may be provided between the neck portion C5 and a sprue (not shown), or may be a so-called lifting feeder. Further, the neck portion C5, which is a weir, may connect the runner C2 and the product portion C4.

Further, although the product part C4 shown in FIG. 3 projects above the top part C3t of the feeder C3, the upper end (here, the upper surface C41) of the product part C4 is provided below the top part C3t of the feeder C3. It may be one that has been created.

FIG. 4 is a sectional view of a mold for casting the casting shown in FIG. This sectional view is a sectional view when viewed from the same side direction as FIG.

The mold M shown in FIG. 4 is a sand mold, and is provided with a spout forming space M1, a runner forming space M2, a feeder forming space M3, a product portion forming space M4, and a neck portion forming space M5. The upper end of the sprue forming space M1 becomes the receiving port M11. The receiving port M11 is provided above the top of the feeder C3 shown in FIG. That is, the upper end of the gate forming space M1 is provided above the top of the feeder forming space M3. Further, the lower end of the sprue formation space M1 becomes the sprue bottom M12.

The feeder formation space M3 is a space for casting a feeder having a basic shape in which a columnar body is sandwiched from the height direction while the sphere is halved, and a hemispherical first hemispherical space M31 is provided on the upper side. The hemispherical second hemisphere space M32 is a space in which a columnar cylindrical space M33 is provided between the first hemisphere space M31 and the second hemisphere space M32. In the mold M shown in FIG. 4, a parting plane is provided at the boundary between the cylindrical space M33 and the second hemisphere space M32 (see the chain double-dashed line in FIG. 4), but the parting plane is above the boundary. May be present or may be below the boundary.

The product portion forming space M4 shown in FIG. 4 projects above the top of the riser forming space M2, but the upper end of the product portion forming space M4 is provided below the top of the riser forming space M2. It may be one that has been created.

In order to cast the casting C shown in FIG. 2, a first step of pouring molten metal of cast iron into the mold M shown in FIG. 4 and a second step of taking out the casting C from the mold M into which the molten metal has been poured are carried out. To do.

The mold M may be a mold having an upper surface and a lower surface divided by a parting surface, or a molten metal of a non-ferrous metal such as an aluminum alloy may be poured.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
(Example 1)
As Example 1, the casting C shown in FIG. 2 is used. In the riser C3 of the casting C, the height (40 mm) of the cylindrical portion C33 corresponds to 0.5 times the diameter (D) of 80 mm. Hereinafter, the feeder C3 shown in FIG. 3, that is, the feeder C3 in Example 1 is referred to as a vertically elongated spherical (1) feeder. The entire height (H) of the feeder C3 having a vertically long spherical shape (1) is 120 mm.

Table 1 shows the volume, surface area, and modulus (volume of the feeder/surface area of the feeder) of the feeder C3 having the vertically long spherical shape (1).

As shown in FIG. 2, there is a product part C4 or an adjacent feeder C3 in the radial direction of the feeder C3, and there is a space in particular in the arrow direction shown in FIG. 2(a). Absent. The longitudinally elongated (1) feeder C3 is obtained by extending a truly spherical feeder only in the height direction (vertical direction). The volume of the 80 mm spherical feeder having the same diameter is 268083 mm ³ . The riser C3 having a vertically long spherical shape (1) has a volume 1.75 times larger than that of a true spherical riser having the same diameter.

In practice, the riser is used after being subjected to a modification of an appropriate shape with respect to the basic shape so that it can be easily used as a mold or casting model. For example, an appropriate draft angle, corner R, corner R, etc. may be provided for the mold release property of the molding, or a conical hole or a V groove may be provided on the top of the feeder to induce shrinkage of the top of the feeder. A score is provided, or part of the shape of the feeder is cut off in relation to the product section, or a surplus is added. In some cases, a rod-shaped portion having a diameter or width smaller than the diameter or width of the feeder may be additionally provided on the basic shape of the feeder in order to apply the molten metal head (melt pressure). In the feeder C3 shown in FIG. 3, these modification deformations are omitted in the drawing, and these modification deformations are not taken into account in the calculation of the volume and the surface area. This also applies to Example 2 and subsequent examples and the comparative example.

Further, the diameter of a true sphere having the same volume as that of the feeder C3 having a vertically long spherical shape (1) (equal volume sphere diameter) and the surface area of the true sphere (equal volume sphere surface area) obtained by using the diameter are determined, and further, Using the equal volume sphere surface area, the sphericity represented by "equal volume sphere surface area/surface area of riser spherical (1) riser C3" was determined. These values are also shown in Table 1. The sphericity of the longitudinally spherical (1) feeder C3 was 0.968.

Furthermore, when the modulus per unit volume was examined as the feeder efficiency, it was 0.332×10 ⁻⁴ mm ² .
(Example 2)
FIG. 5: is a figure which shows the feeder periphery of the casting in Example 2. As shown in FIG. Also in FIG. 5, similarly to FIG. 3, a front view is shown in FIG. 5B and a plan view is shown in FIG. A right side view is shown in FIG.

Hereinafter, components having the same names as those of the components described so far will be described with the same reference numerals as those described above. In addition, description of items that are the same as those described above may be omitted.

The feeder C3 shown in FIG. 5 is a feeder provided in a casting product that is cast by the eight-sided side-loading casting described with reference to FIG. 2, and is the same product portion as that shown in FIGS. 2 and 3. The molten metal is supplied to C4 through the same neck portion C5 as the neck portion shown in FIGS. 2 and 3.

The feeder C3 shown in FIG. 5 has a basic shape in which a columnar body having a height of 60 mm is sandwiched from the height direction while a sphere having a diameter of 80 mm is halved. That is, as shown in FIG. 5B, the feeder C3 according to the second embodiment has a first hemispherical portion C31, a second hemispherical portion C32, and a cylinder sandwiched between the first hemisphere portion C31 and the second hemisphere portion C32. It has a portion C33, and the height of the cylindrical portion C33 is 20 mm higher than that of the vertically long spherical (1) feeder. Hereinafter, the feeder C3 shown in FIG. 5, that is, the feeder C3 in Example 2 is referred to as a vertically long spherical (2) feeder. The height (60 mm) of the cylindrical portion C33 of the feeder C3 having the vertically long spherical shape (2) corresponds to 0.75 times the diameter (D) of 80 mm. Further, the height (H) of the feeder C3 having a vertically long spherical shape (2) is 140 mm.

Table 1 shows the volume, surface area, and modulus (volume of the feeder/surface area of the feeder) of the feeder C3 having a vertically long spherical shape (2).

As for the feeder C3 having the vertically long spherical shape (2), like the feeder having the vertically elongated spherical shape (1), a true spherical feeder is extended only in the height direction (vertical direction), and the feeder C3 having the vertically elongated spherical shape (2) is formed. The volume is 2.13 times that of a true spherical feeder having the same diameter of 80 mm.

Further, the diameter of a true sphere (equal volume sphere diameter) having the same volume as that of the feeder C3 having a vertically long spherical shape (2) and the surface area (equal volume sphere surface area) of the true sphere obtained by using the diameter are obtained, and further Using the equal volume sphere surface area, the sphericity represented by "equal volume sphere surface area/surface area of vertically oriented sphere (2) feeder C3" was determined. These values are also shown in Table 1. The sphericity of the riser C3 having the vertically long spherical shape (2) was 0.944.

Further, when considering the modulus per unit volume as the feeder efficiency, it was 0.284×10 ⁻⁴ mm ² .
(Example 3)
FIG. 6 is a diagram showing the periphery of a cast iron feeder according to the third embodiment. In FIG. 6, as in FIG. 3, a front view is shown in FIG. 6B and a plan view is shown in FIG. A right side view is shown in FIG.

The riser C3 shown in FIG. 6 is also a riser provided in a casting formed by the eight-sided side-insertion casting described with reference to FIG. 2, like the vertically long spherical (2) riser shown in FIG. Therefore, the molten metal is supplied to the same product portion C4 as the product portion shown in FIGS. 2 and 3 through the same neck portion C5 as the neck portion shown in FIGS.

The feeder C3 shown in FIG. 6 has a basic shape in which a columnar body having a height of 86.6 mm is sandwiched from the height direction while a sphere having a diameter of 80 mm is halved. That is, as shown in FIG. 6B, the feeder C3 according to the third embodiment also has the first hemisphere portion C31, the second hemisphere portion C32, and the columnar portion C33, and has the vertically long spherical shape (1) according to the first embodiment. The height of the cylindrical portion C33 is 46.6 mm higher than that of the feeder. Hereinafter, the feeder C3 shown in FIG. 6, that is, the feeder C3 in Example 3 is referred to as a vertically elongated spherical (3) feeder. The height (86.6 mm) of the cylindrical portion C33 of the feeder C3 having the vertically long spherical shape (3) corresponds to 1.08 times the diameter (D) of 80 mm. Further, the height (H) of the whole riser C3 having a vertically long spherical shape (3) is 166.6 mm.

The sphere is not limited to a true sphere, and may be, for example, an ellipsoid. Further, the columnar portion C33 is not limited to the one whose cross-sectional shape along the direction orthogonal to the height direction is a perfect circle. For example, the cross-sectional shape may be elliptical or rounded-rectangular.

Further, the feeder C3 shown in FIG. 6 may be provided between the neck portion C5 and a gate (not shown), or may be a so-called lift feeder.

Table 1 shows the volume, surface area, and modulus (volume of the feeder/surface area of the feeder) of the feeder C3 having a vertically long spherical shape (3).

Like the vertically elongated spherical (1) feeder, the vertically elongated spherical (3) feeder C3 extends a true spherical feeder only in the height direction (vertical direction), and the top C3t of the feeder C3 shown in FIG. Projects above the upper end (here, the upper surface C41) of the product portion C4. Depending on the shape of the product, if the top of the riser is below the height of the top of the product, the melt pressure at the top of the product will be low, and the top of the product will be pulled before the top of the riser (solidification). Shrinkage may occur) and shrinkage cavity defects may occur in the product part. In this case, even if there is a space in the radial direction of the feeder, the volume of the feeder is not increased in the radial direction of the feeder, but the volume of the feeder is increased only in the upward direction. That is, even if it is possible to have a spherical basic shape as the basic shape of the feeder due to the positional relationship with at least one of the sprue, runner, product portion, and neck portion, the diameter of the feeder is long. Then, instead of increasing the volume of the whole feeder, the volume of the feeder is increased only in the upward direction. In this way, the top C3t of the feeder C3 is positioned higher than the upper end of the product C4. The same applies to the mold, and the top of the riser forming space is located higher than the upper end of the product forming space. By doing so, it becomes possible to draw from the top portion C3t of the feeder C3. The riser C3 having a vertically long spherical shape (3) has a volume 2.62 times that of a true spherical riser having the same diameter of 80 mm, but the height of the riser C3 having a vertically long spherical shape (3) is large. The volume is reduced to 0.3 times or less as compared with a true spherical feeder having a diameter of 166.6 mm.

Further, the diameter of a true sphere (equal volume sphere diameter) having the same volume as that of the feeder C3 having a vertically long spherical shape (3) and the surface area (equal volume sphere surface area) of the true sphere obtained by using the diameter are obtained, and further Using the equal volume sphere surface area, the sphericity represented by "equal volume sphere surface area/surface area of vertically oriented spherical (3) feeder C3" was determined. These values are also shown in Table 1. The sphericity of the riser having the vertically long spherical shape (3) is 0.913, which is 0.91 or more.

Further, when the modulus per unit volume was examined as the feeder efficiency, it was 0.239×10 ⁻⁴ mm ² .
(Example 4)
7: is a figure which shows the feeder periphery of the casting in Example 4. FIG. Also in FIG. 7, as in FIG. 3, a front view is shown in FIG. 7B and a plan view is shown in FIG. A right side view is shown in FIG.

The riser C3 shown in FIG. 7 is also a riser provided in a casting formed by the eight-sided side-insertion casting described with reference to FIG. 2, as in the case of the vertically elongated spherical (2) riser shown in FIG. Therefore, the molten metal is supplied to the same product portion C4 as the product portion shown in FIGS. 2 and 3 through the same neck portion C5 as the neck portion shown in FIGS.

The feeder C3 shown in FIG. 7 has a basic shape in which a columnar body having a height of 12.3 mm is sandwiched from the height direction while a sphere having a diameter of 88 mm is halved. That is, as shown in FIG. 7B, the feeder C3 according to the fourth embodiment also has the first hemisphere portion C31, the second hemisphere portion C32, and the columnar portion C33, and has the vertically long spherical shape (1) according to the first embodiment. The feeder is 8 mm larger in the radial direction than the feeder, and the height of the cylindrical portion C33 is 27.7 mm lower. Hereinafter, the feeder C3 shown in FIG. 7, that is, the feeder C3 in Example 4 is referred to as a vertically elongated (4) feeder. The height (12.3 mm) of the cylindrical portion C33 of the feeder C3 having the vertically long spherical shape (4) corresponds to 0.14 times the diameter (D) of 88 mm. Further, the height (H) of the feeder C3 having the vertically long spherical shape (4) is 100.3 mm.

Table 1 above shows the volume, surface area, and modulus (volume of riser/surface area of riser) of riser C3 having a vertically long spherical shape (4).

The feeder C3 having the vertically elongated spherical shape (4) is different from the feeder having the vertically elongated spherical shape (1) in both a radial direction and a height direction (vertical direction) with respect to a true spherical feeder having a diameter of 80 mm. The volume of the feeder is 1.61 times that of a true spherical feeder having a diameter of 80 mm.

Further, the diameter of a true sphere having the same volume as that of the feeder C3 having a vertically long spherical shape (4) (equal volume sphere diameter) and the surface area of the true sphere (equal volume sphere surface area) obtained by using the diameter are determined, and further, Using the equal volume sphere surface area, the sphericity represented by "equal volume sphere surface area/surface area of riser C3 of longitudinal sphere (4)" was determined. These values are also shown in Table 1. The feeder C3 having the vertically long spherical shape (4) has a sphericity of 0.996, which has a higher sphericity than the feeder having the vertically long spherical shape (1) and is close to a true sphere. In the case of a true sphere, the sphericity is 1.

Furthermore, when the modulus per unit volume was examined as the feeder efficiency, it was 0.361×10 ⁻⁴ mm ² .
(Example 5)
FIG. 8: is a figure which shows the feeder periphery of the casting in Example 5. As shown in FIG. Also in FIG. 8, as in FIG. 3, a front view is shown in FIG. 8B and a plan view is shown in FIG. A right side view is shown in FIG.

The feeder C3 shown in FIG. 8 is also a feeder provided in a casting that is cast by the side-loading casting of 8 pieces described with reference to FIG. 2, like the feeders in the above embodiments. The molten metal is supplied to the same product portion C4 as the product portion shown in FIG. 3 and FIG. 3 through the same neck portion C5 as the neck portion shown in FIG. 2 and FIG.

The feeder C3 shown in FIG. 8 is different in shape from the feeders in the previous embodiments. That is, it has a basic shape in which a sphere having a diameter of 80 mm is halved and an intermediate body having a height of 60 mm is sandwiched from the height direction, but the sphere having a diameter of 80 mm referred to here is not a perfect circle in cross section. The shape is a rectangular shape with rounded corners and two parallel lines of equal length and two semicircular arcs with a radius of 40 mm. That is, it is a shape in which a true spherical body having a diameter (D) of 80 mm is crushed in the arrow direction shown in FIG. Further, the intermediate body having a height of 60 mm has an upper surface and a lower surface of a rounded rectangular shape. The cross-sectional shape of this intermediate along the parting plane indicated by the alternate long and short dash line is also a rounded rectangular shape. Further, the feeder C3 shown in FIG. 8 looks like a rounded rectangle (oval) even when viewed from the side surface (the direction of the arrow shown in FIG. 2), as shown in FIG. Hereinafter, the feeder C3 shown in FIG. 8, that is, the feeder C3 in Embodiment 5 is referred to as a feeder having a vertically and horizontally long spherical shape (1). The height (H) of the feeder C3 having a vertically and horizontally long spherical shape (1) is 140 mm, and the length in the width direction (corresponding to the left and right direction in FIG. 8C) orthogonal to the arrow shown in FIG. 2 is 100 mm. Yes, it is 1.25 times wider than the riser C3 having a vertically long spherical shape (3) shown in FIG.

The vertical and horizontal oblong (1) feeder C3 has a shape obtained by crushing a true spherical feeder in the direction of the arrow shown in FIG. 2A so as to form an oval shape, and the arrow shown in FIG. It spreads in the width direction orthogonal to the direction, increasing the volume of the riser.

Like the feeder shown in FIG. 6, the feeder C3 shown in FIG. 8 may be extended until the top portion C3t projects above the upper end (here, the upper surface C41) of the product portion C4. The same applies to the mold, and the top of the feeder forming space may be located higher than the upper end of the product forming space.

Table 1 shows the volume, surface area, and modulus (volume of riser/surface area of riser) of the riser C3 having a vertically and horizontally long spherical shape (1).

Further, the diameter of a true sphere (equal volume sphere diameter) having the same volume as that of the feeder C3 having a vertically and horizontally long spherical shape (1) and the surface area of the true sphere (equal volume sphere surface area) obtained by using the diameter are obtained. Using the equivalent volume sphere surface area, the sphericity represented by “equal volume sphere surface area/surface area of riser C3 (1) riser C3” was determined. These values are also shown in Table 1. The sphericity of the feeder C3 having a vertically and horizontally long spherical shape (1) was 0.960.

Furthermore, when the modulus per unit volume was examined as the feeder efficiency, it was 0.283×10 ⁻⁴ mm ² .
(Example 6)
FIG. 9: is a figure which shows the feeder periphery of the casting in Example 6. As shown in FIG. Also in FIG. 9, as in FIG. 3, a front view is shown in FIG. 9B and a plan view is shown in FIG. A right side view is shown in FIG.

The feeder C3 shown in FIG. 9 is also a feeder provided in a casting cast by the side-loading casting of 8 pieces described with reference to FIG. 2, like the feeders in the above-described embodiments. The molten metal is supplied to the same product portion C4 as the product portion shown in FIG. 3 and FIG. 3 through the same neck portion C5 as the neck portion shown in FIG. 2 and FIG.

The feeder C3 shown in FIG. 9 is also the same as the feeder having a vertically and horizontally long spherical shape (1) shown in FIG. 8, and a sphere having a diameter of 80 mm is halved while an intermediate body having a height of 60 mm is sandwiched from the height direction. It has a basic shape. In Example 6 as well, the spherical body having a diameter of 80 mm is not a perfect circle in cross section but a rounded rectangular shape, and is a shape composed of two parallel lines of equal length and two semi-circular arcs having a radius of 40 mm. .. That is, it is a shape in which a true spherical body having a diameter (D) of 80 mm is crushed in the arrow direction shown in FIG. Further, the intermediate body having a height of 60 mm has an upper surface and a lower surface of a rounded rectangular shape. The cross-sectional shape of this intermediate along the parting plane indicated by the alternate long and short dash line is also a rounded rectangular shape. Further, the feeder C3 shown in FIG. 9 looks like a rounded rectangle even when viewed from the side surface (the direction of the arrow shown in FIG. 2), as shown in FIG. Hereinafter, the feeder C3 shown in FIG. 9, that is, the feeder C3 in Example 6 is referred to as a feeder having a vertically and horizontally long spherical shape (2). The height (H) of the feeder C3 having a vertically and horizontally long spherical shape (2) is 140 mm, and the length in the width direction (corresponding to the left and right direction in FIG. 9C) orthogonal to the arrow shown in FIG. 2 is 120 mm. Yes, it is 1.5 times wider than the vertically long spherical (3) riser C3.

The vertical and horizontal oblong (2) feeder C3 has a shape obtained by crushing a true spherical feeder in the direction of the arrow shown in FIG. 2(a) than the vertically and horizontally oblong (1) feeder C3. It expands in the width direction orthogonal to the arrow direction shown in (a), and further increases the volume of the feeder.

Table 1 above shows the volume, surface area, and modulus (volume of the feeder/surface area of the feeder) of the feeder C3 having the vertically and horizontally long spherical shape (2).

Further, the diameter of a true sphere (equal volume sphere diameter) having the same volume as that of the feeder C3 having a vertically and horizontally long spherical shape (2) and the surface area (equal volume sphere surface area) of the true sphere obtained by using the diameter are obtained. Using the equal volume sphere surface area, the sphericity represented by "equal volume sphere surface area/surface area of riser C3 (2) riser C3" was determined. These values are also shown in Table 1. The sphericity of the feeder C3 having a vertically and horizontally long spherical shape (2) was 0.955.

Furthermore, when the modulus per unit volume was examined as the feeder efficiency, it was 0.250×10 ⁻⁴ mm ² .
(Comparative example)
FIG. 10: is a figure which shows the feeder periphery of the casting in a comparative example. Also in FIG. 10, similarly to FIG. 3, a front view is shown in FIG. 10B and a plan view is shown in FIG. A right side view is shown in FIG.

Hereinafter, components having the same names as the components described in FIG. 1 will be described with the same reference numerals used in FIG. In addition, description of items that are the same as those described above may be omitted.

The riser C3′ shown in FIG. 10 is a riser provided in a casting that is cast by the eight-row side-insertion casting described with reference to FIG. 1, and is the same product as the product section shown in FIGS. 2 and 3. Molten metal is supplied to the portion C4′ through the same neck portion C5′ as the neck portion shown in FIGS. 2 and 3.

The feeder C3' shown in FIG. 10 has a basic shape of a cylinder having a diameter (D) of 80 mm and a height (H) of 140 mm. The height (140 mm) of this feeder C3' corresponds to 1.75 times the diameter of 80 mm. Hereinafter, the feeder C3' shown in FIG. 10, that is, the feeder C3' in the comparative example is referred to as a column-shaped feeder.

Table 1 also shows the volume, surface area, and modulus (volume of feeder/surface area of feeder) of this cylindrical feeder C3'.

Further, the diameter of a true sphere having the same volume as that of the cylindrical feeder C3′ (equal volume sphere diameter) and the surface area of the true sphere (equal volume sphere surface area) obtained by using the diameter are obtained, and the equal volume Using the spherical surface area, the sphericity represented by "equal volume spherical surface area/surface area of cylindrical feeder C3'" was determined. These values are also shown in Table 1. The cylindrical feeder C3' had a sphericity of 0.846, which was less than 0.91.

Further, when the modulus per unit volume was examined as the feeder efficiency, it was 0.221×10 ⁻⁴ mm ² .

In order to manufacture a sound casting product without shrinkage cavity defects, it is necessary to compensate for the solidification shrinkage of the product part, and for that purpose it is necessary to continue supplying the molten metal from the feeder until the product part is solidified. For that purpose, it is necessary to make the solidification time of the feeder longer than the solidification time of the product part. The solidification time t is proportional to the square of the modulus M according to Kuvolnov's law of the following formula (1), and since the modulus M can be expressed as the following formula (2), the modulus M is an index for evaluating the ability of the feeder. Is very important.
t=C·M ² formula (1)
M=V/S Formula (2)
However, C represents a coefficient, V represents a volume, and S represents a surface area.

However, the larger the volume of the feeder, the larger the modulus M and the higher the ability of the feeder, but the heavier the casting weight. Therefore, it is not preferable in terms of casting yield (product part weight/cast weight). Therefore, as described above, the modulus of the feeder per unit volume was determined as the feeder efficiency E. That is, the feeder efficiency E is expressed by the following equation (3).
E=M/V=S ^-1 Formula (3)
As a conventional feeder, a cylindrical feeder having a height of 1.5 to 2 times the diameter is generally used. Therefore, the column-shaped feeder having a height of 1.75 times the diameter shown in FIG. 10 corresponds to a typical example of general feeders. The following is a calculation of the column-shaped riser whose height Hc is α times the diameter D, using the above formulas (1) to (3).
Hc=αD
Vc=(π/4)×D ² ×Hc=(π/4)×αD ³ Formula (4)
Sc=(π/4)×D ² ×2+πD×Hc=π/2×(1+2α)D ²
Mc=Vc/Sc={π/4×αD ³ }/{π/2×(2α+1)D ² }=αD/{2(2α+1)} Formula (5)
Ec=Sc ⁻¹ =2D ⁻² /{π(2α+1)} Formula (6)
Here, Vc represents the volume of the column-shaped feeder, Sc represents the surface area of the column-shaped feeder, Mc represents the modulus of the column-shaped feeder, and Ec represents the feeder efficiency of the column-shaped feeder.

Next, a vertically long spherical feeder (for example, feeders of Examples 1 to 4) in which a cylindrical body is sandwiched from the height direction while a ball having the same diameter D as the diameter of the cylindrical feeder is halved is examined. To do. First, assuming that the total height Hs of the vertically elongated feeder is β times the diameter D,
Hs=βD
It is represented by. Then, the height of the sandwiched cylinder becomes Hs-D. Then, the volume Vs and the surface area Ss of the vertically elongated feeder are represented by the following equations.
Vs=(π/6)×D ³ +(π/4)×D ² ×(Hs−D)=(π/12)×D ³ (3β-1) Formula (7)
Ss=πD ² +πD(Hs−D)=πβD ²
From the above equation (2), the modulus Ms of the vertically long globular feeder is represented by the following equation.
Ms=Vs/Ss={(π/12)×D ³ (3β-1)}/{πβD ² }=(D/12β)×(3β-1) Formula (8)
Further, from the above formula (3), the feeder efficiency Es of the vertically long spherical feeder is expressed by the following equation.
Es=Ss ⁻¹ =(πβ) ⁻¹ ×D ⁻² Formula (9)
Next, a vertically long spherical feeder having a modulus Ms equivalent to the modulus Mc of the cylindrical feeder will be examined.
Since Mc=Ms, using the above equations (5) and (8),
αD/{2(2α+1)}=(D/12β)×(3β-1)
Holds,
β=(2α+1)/3 Formula (10)
Is required. This formula (10) has a cylindrical feeder having a height Hc that is α times the diameter D and a β times the diameter D that has a modulus Ms equivalent to the modulus Mc of the cylindrical feeder. This is an equation that holds with a vertically-oriented spherical feeder having Hs.
From the above formula (7), the volume Vs of the vertically elongated feeder is
Vs=(π/12)×D ³ (3β-1)
And substituting equation (10) above,
Vs=(π/6)×αD ³
become.
Further, the volume Vc of the column-shaped feeder is calculated from the above formula (4) as
Vc=(π/4)×αD ³
become.
These results,
Vs/Vc={(π/6)×αD ³ }/{(π/4)×αD ³ }=2/3≈0.6667
Therefore, it can be seen that the volume of the vertically elongated spherical shape having the same diameter and modulus as the cylindrical feeder is always smaller than that of the cylindrical feeder by about 33% regardless of the diameter and the height.

The comparison of feeder efficiency is as follows.
The feeder efficiency Ec of a cylindrical feeder is calculated from the above equation (6) as
Ec=2D ⁻² /{π(2α+1)}
The feeder efficiency Es of the vertically long spherical feeder is expressed by the following formula (9):
Es=(πβ) ⁻¹ ×D ⁻²
And substituting the above equation (10) into
Es=3D ⁻² /{π(2α+1)}
become.
As a result, the feeder efficiency ratio of the vertically long spherical feeder to the cylindrical feeder is:
Es/Ec=[3D ⁻² /{π(2α+1)}]/[2D ⁻² /{π(2α+1)}]=3/2=1.5
From this, it can be seen that the vertically long spherical feeder has a feeder efficiency that is 1.5 times that of the cylindrical feeder.

In addition, in a cylindrical feeder having a height Hc of 1.75 times the diameter D, which is a comparative example,
α=1.75
When the sphericity of the column-shaped feeder is calculated, it becomes 0.846 as shown in Table 1. On the other hand, if α=1.75 is substituted into the above equation (10),
β=(2×1.75+1)/3=1.5
become. That is, the height of a vertically elongated spherical feeder having a modulus Ms equivalent to the modulus Mc of a cylindrical feeder having a height Hc of 1.75 times the diameter D is 1.5 times the diameter D. This vertical spherical feeder having a height Hs of 1.5 times the diameter D becomes the vertical spherical (1) feeder C3 of Example 1, and when the sphericity is calculated, it is as shown in Table 1. Becomes 0.968.

Therefore, it can be seen that, between the column-shaped riser and the vertically long spherical riser having the same modulus, the vertically long spherical riser has a higher sphericity than the columnar riser.

Next, the column-shaped riser C3′ of the comparative example whose height was 1.75 times the diameter was a riser corresponding to a typical example of a general riser as described above. A comparison will be made between the column-shaped feeder C3' and each example.

When the feeder in Example 1 (the feeder C3 having a vertically long spherical shape (1)) and the column-shaped feeder C3' are compared, the modulus is the same. On the other hand, the sphericity of the feeder C3 in Example 1 is higher than that of the cylindrical feeder C3'. Further, looking at the feeder efficiency, it can be seen that the feeder C3 in Example 1 is 1.5 times as much as the cylindrical feeder C3'. Further, looking at the feeder volume, it can be seen that the feeder C3 in Example 1 is 0.667 times as large as the cylindrical feeder C3'.

By using the feeder C3 of Example 1, the sphericity is higher than that of the cylindrical feeder C3′, and the modulus is the same, that is, the heat retaining property as the feeder, in other words, the feeder effect is the same, While the feeder efficiency is 1.5 times, the volume can be reduced by 33% compared to the cylindrical feeder C3′.

The feeder in Example 2 (the feeder C3 having a vertically long spherical shape (2)) has a modulus 1.04 times that of the cylindrical feeder C3'. Further, the sphericity of the feeder C3 in Example 2 is higher than that of the cylindrical feeder C3'. Further, looking at the feeder efficiency, it can be seen that the feeder C3 in Example 2 is 1.29 times that of the cylindrical feeder C3'. Further, looking at the feeder volume, it is found that the feeder C3 in Example 2 is 0.810 times as large as the cylindrical feeder C3'.

By using the feeder C3 of Example 2, the sphericity is higher than that of the cylindrical feeder C3′, and the modulus is also increased to improve the heat retaining property as a feeder. According to the above formula (1), the solidification time is 1.08 times longer than that of the cylindrical feeder C3′, and the feeder efficiency is 1.29 times, while the volume is cylindrical feeder C3′. 'Can be reduced by 19%.

The feeder in Example 3 (the feeder C3 having a vertically long spherical shape (3)) has a modulus 1.08 times that of the cylindrical feeder C3'. Further, looking at the feeder efficiency, it is understood that the feeder C3 in Example 3 is inferior to the feeder C3 in Example 2, but 1.08 times as much as the cylindrical feeder C3'. Further, looking at the feeder volume, the feeder C3 in Example 3 has almost the same volume as the cylindrical feeder C3'. The sphericity of the feeder C3 of Example 3 is 0.913, which is lower than the feeder C3 of Example 2, but is sufficiently higher than the cylindrical feeder C3'.

By using the riser C3 of Example 3, the sphericity is higher than that of the column-shaped riser C3′, and the volume is similar to that of the column-shaped riser C3′, but the modulus is high. The heat retaining property as a feeder is improved, and the feeder of Example 3 has a solidification time of 1.17 times longer than that of a cylindrical feeder C3′, and further, the feeder efficiency is also improved.

The riser in Example 4 (the riser C3 having a vertically long spherical shape (4)) has a modulus similar to that of the columnar riser C3'. Further, the sphericity of the feeder C3 in Example 4 is much higher than that of the cylindrical feeder C3'. Further, looking at the feeder efficiency, it is found that the feeder C3 in Example 4 is 1.63 times as high as the cylindrical feeder C3'. Further, looking at the feeder volume, it is found that the feeder C3 in Example 4 is 0.614 times as large as the cylindrical feeder C3', and the volume is suppressed.

By using the feeder C3 of Example 4, the sphericity is much higher than that of the cylindrical feeder C3′, and the feeder efficiency is 1.63 times even if the modulus is about the same. Also, the volume can be reduced by 39% with respect to the cylindrical feeder C3′.

The riser in Example 5 (the riser C3 having a vertically and horizontally long spherical shape (1)) has a modulus 1.07 times that of the columnar riser C3'. Further, the sphericity of the feeder C3 in Example 5 is higher than that of the cylindrical feeder C3'. Further, looking at the feeder efficiency, it can be seen that the feeder C3 in Example 5 is 1.28 times that of the cylindrical feeder C3'. Further, looking at the feeder volume, it is found that the feeder C3 in Example 5 is 0.833 times as large as the cylindrical feeder C3'.

By using the feeder C3 of Example 5, the sphericity is higher than that of the columnar feeder C3′, and the modulus is also increased, so that the heat retaining property of the feeder is improved. , Solidification time is 1.14 times longer than the cylindrical feeder C3', and the feeder efficiency is 1.28 times, while the volume is reduced by 17% compared to the cylindrical feeder C3'. can do.

The feeder in Example 6 (the feeder C3 having a vertically and horizontally long spherical shape (2)) has a modulus 1.13 times higher than that of the cylindrical feeder C3'. Also, the sphericity of the feeder C3 in Example 6 is higher than that of the cylindrical feeder C3'. Further, looking at the feeder efficiency, it can be seen that the feeder C3 in Example 6 is 1.13 times that of the cylindrical feeder C3'. Further, looking at the feeder volume, the feeder C3 in Example 6 has the same volume as the cylindrical feeder C3'.

By using the feeder C3 of Example 6, the sphericity is higher than that of the cylindrical feeder C3′, and the volume is the same as that of the cylindrical feeder C3′, but the modulus is high. The heat retaining property as a feeder is improved, and the feeder of Example 6 has a solidification time that is 1.28 times longer than that of a cylindrical feeder C3′, and the feeder efficiency is also improved.

Here, when the volume of a certain feeder is V and the surface area is S, the modulus is represented by V/S=M.

The volume (Va) of a true sphere (equal volume sphere) having the same volume as the certain feeder (V) is Va=V=(π/6)Da ³ when the diameter is Da. The surface area (Sa) becomes Sa=πDa ² . As a result, the modulus (Ma) of the equal volume sphere becomes Ma=Da/6. As a result, the relationship between the volume (Va) and the modulus (Ma) of the equal volume sphere is Va=V=(π/6)Da ³ =(π/6)(6Ma) ³ =36πMa ³ , and Ma=( V/36π) ^1/3 can be rewritten.

The volume (Vb) of a true sphere (equal modulus sphere) having the same modulus (Mb) as the modulus (M) of a certain feeder is Vb=(π/6)Db ³ when the diameter is Db. , Its surface area (Sb) is Sb=πDb ² . As a result, the modulus (Mb) of the equal modulus sphere becomes Mb=M=Db/6. As a result, the relationship between the volume (Vb) and the modulus (Mb) of the equal modulus sphere is Vb=(π/6)Db ³ =(π/6)(6M) ³ =36πM ³ and M=(Vb/ 36π) It can be rewritten as ^1/3 .

Then, the sphericity (ψ) of the certain riser is “surface area (Sa) of equal volume sphere/surface area (S) of the certain riser”, and ψ=Sa/(V/M)=(Sa・M)/V=(Sa·M)/(Sa·Ma)=M/Ma=[(Vb/36π) ^1/3 ]/[(V/36π) ^1/3 ]=(Vb/V) ¹ It can be rewritten as ^/3 . As a result, the ratio (Vb/V) of the volume (V) of the certain riser to the volume (Vb) of the equal modulus sphere becomes Vb/V=φ ³ when expressed by the sphericity (φ). ..

When the certain riser has a sphericity (ψ) of 0.91, the volume (v) of the certain riser is represented by V=Vb/ψ ³ =1.33Vb. .. As a result, in the case of a riser having a sphericity (ψ) of less than 0.91, the volume increases by more than 33% with respect to the volume (Vb) of an ideal spherical equal modulus sphere. Will end up. The volume increase exceeding 1/3 cannot be overlooked, and the casting yield is markedly reduced.

Further, of the feeder C3 of Example 3 and the feeder C3 of Example 6 which have the same volume as the cylindrical feeder C3′, the feeder C3 of Example 3 is extended in the height direction only. On the other hand, the feeder C3 according to the sixth embodiment extends not only in the height direction but also in the width direction. In the feeder C3 of Example 6, the degree of extension was relatively small even though it was extended in two directions. On the other hand, in the feeder C3 of Example 3, the degree of extension was extended in one direction. Was relatively large, resulting in a difference in sphericity. From this, if it is assumed that the volume is the same as that of the cylindrical feeder C3′, the limit when extending the feeder in one direction can be controlled by the sphericity, and the limit value It can be seen that is 0.91.

The basic shape of the feeder is not limited to the basic shape in which spherical parts obtained by dividing the sphere such as vertically long spheres and vertically and horizontally long spheres are dispersed, and the sphericity is 0.91 or more and less than 1.00. Any basic shape will do. The same applies to the basic shape of the feeder formation space.

According to the feeder C3 in each example, the sphericity is as high as 0.91 or more, and the heat retention of the feeder is equal to or more than that of the cylindrical feeder C3' of the comparative example. As a result, it has a suitable modulus corresponding to the product portion C4 and has a high sphericity of 0.91 or more, so that a sufficient feeder effect can be obtained with a small-volume feeder. Therefore, even when the spherical basic shape cannot be adopted as the basic shape of the feeder, the feeder effect can be exhibited without lowering the casting yield. As a result, the molten metal required for the feeder can be significantly reduced, and the power consumption for melting and the molten metal processing cost can be significantly reduced. It can also contribute greatly to CO ₂ reduction.

C casting C2 runner C3 riser C4 product part C5 neck part C31 first hemisphere part C32 second hemisphere part C33 columnar part M mold M1 gate forming space M3 riser forming space M4 product part forming space M5 neck forming space

Claims (8)

With a sprue
A runner,
With a feeder
Product department,
A neck portion connected to the product portion,
The sphericity is 0.91 or more in a state where the riser cannot take a basic spherical shape due to the positional relationship with at least one of the sprue, the runner, the product portion, and the neck portion. A casting characterized by having a basic shape of less than 0.000. With a feeder
With product section,
The casting is characterized in that the top of the feeder has a higher position than the upper end of the product portion and has a basic shape with a sphericity of 0.91 or more and less than 1.00. The casting according to claim 1 or 2, wherein the feeder has a basic shape in which a columnar body is sandwiched from the height direction while the sphere is halved. The casting according to any one of claims 1 to 3, wherein the feeder has a cross-sectional shape along the direction orthogonal to the height direction of an ellipse or a rounded rectangle. A spout forming space,
A runner formation space,
A feeder formation space,
Product part formation space,
A neck portion forming space connected to the product portion forming space,
The riser forming space cannot have a spherical basic space shape due to the positional relationship with at least one of the gate forming space, the runner forming space, the product part forming space, and the neck part forming space. A mold having a basic space shape having a sphericity of 0.91 or more and less than 1.00 in a state. A feeder formation space,
With a product part formation space,
A mold characterized in that the riser forming space has a top portion higher than an upper end of the product portion forming space and has a basic space shape with a sphericity of 0.91 or more and less than 1.00. .. The riser forming space is a space for casting a riser of a basic shape in which a columnar body is sandwiched from the height direction while the sphere is halved, the first hemispherical space having a hemispherical shape on the upper side and the hemisphere on the lower side. -Shaped second hemisphere space, a space in which a columnar cylindrical space is provided between the first hemisphere space and the second hemisphere space,
The mold according to claim 5 or 6, wherein a parting surface is provided at a boundary between the cylindrical space and the second hemisphere space. A first step of pouring molten metal into the mold according to any one of claims 5 to 7;
A second step of taking out a casting from the mold in which the molten metal has been poured.