JP7199058B2 - Castings, molds and casting methods - Google Patents

Description

The present invention relates to a casting comprising a sprue, a runner, a riser, 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 riser is provided at an appropriate location connected to the product through a neck portion, and the riser effect of replenishing the molten metal from the riser in accordance with the solidification shrinkage of the molten metal in the product is exhibited. It is done. The neck is sometimes referred to as a weir, and the riser may be located between the sprue or runner and this neck, or may be located above the product section away from the sprue or runner. may be provided via However, in any case, the ratio of the feeder head to the cast weight is usually 20 to 40%, and as a result, there is a problem that the casting yield indicated by the weight of the product part/the cast weight is low. Therefore, determining the proper shape and size of the riser is an important issue for improving the casting yield, which affects the casting cost.

Therefore, it has been proposed to make the basic shape of the riser spherical (see Patent Document 1, etc.). Certainly, the modulus (the volume of the riser divided by the surface area of the riser), which is a simple indicator of the efficiency of the riser, is better for the spherical riser than for the cylindrical riser that has been common so far. A spherical riser is preferable to a cylindrical riser as it allows for a smaller volume, given the same modulus.

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 the spherical riser with the necessary volume to obtain the riser effect. Even if it is desired to adopt a spherical basic shape as the basic shape of hot water, it may not be possible to adopt it. In particular, in the case of multiple-injection in which a plurality of product parts are provided for one sprue, the greater the number of product parts, the greater the restrictions on the positional relationship tend to be.

FIG. 1 is a diagram showing an eight-piece casting in which eight product parts are provided for one sprue. FIG. 1(a) is a plan view, and FIG. 1(b) is a side view with the product portion omitted.

The casting C' shown in FIG. 1(a) includes eight product parts C4', one runner C2', four feeders C3', and a neck connecting the feeder C3' and the product part C4'. A portion C5' is provided. In addition, a connecting portion C21' of a sprue (not shown) to the bottom of the sprue is shown in the central portion in the extending direction of one runner C2' extending in the horizontal direction of the figure. Each of the four risers C3' shown in FIG. 1(a) has a spherical shape, and two product portions C4' are provided for one riser C3'. Also, in FIG. 1(b), a dashed line is shown so as to pass through the height direction center of the riser C3'. This dashed line corresponds to the parting plane. A casting C' shown in FIG. 1(a) is cast by so-called horizontal casting.

Further, FIG. 1 shows a two-dot chain line that is larger than the feeder head C3'. This two-dot chain line represents the size (volume) of the feeder head C3' required to obtain the feeder effect while maintaining the spherical shape, and the two-dot chain line is the product part. 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 part C4' and the riser C3' is low, and it is often impossible to adopt a spherical basic shape as the basic shape of the riser even if it is desired. . Thus, it may be difficult to secure the modulus required to obtain the riser effect while maintaining the basic shape of the riser in a spherical shape.

On the other hand, if the basic shape of the riser is made into a cylindrical shape, which has been common so far, it is possible to secure the space for arranging the riser, but the riser required to obtain the riser effect The volume of the hot water increases, resulting in a significant drop in casting yield.

Also, depending on the shape of the product, it may be desirable to raise the height of the riser to obtain the riser effect. If it is possible to secure a space, it is conceivable to increase the diameter of the riser in order to increase the height of the riser while maintaining the basic spherical shape. However, if the diameter of the riser is made too large in order to increase the height of the riser, the volume of the riser will unnecessarily increase, and in this case also, the casting yield will decrease significantly.

In view of the above circumstances, the present invention provides a casting having a riser that can exhibit a riser effect while suppressing a decrease in casting yield, a mold for casting the casting, and a casting method using the mold. With the goal.

The first casting that solves the above object is
Yuguchi and
Yumichi and
pusher and
the product department,
a neck portion connected to the product portion;
In a state in which the riser cannot assume a spherical basic shape due to the positional relationship with at least one of the sprue, the runner, the product portion, and the neck portion, a cylinder is formed between halves of a sphere. It is characterized by having a basic shape with a sphericity of 0.91 or more and less than 1.00 by sandwiching the body from the height direction .

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

The second casting that solves the above object is
Yuguchi and
pusher and
with the product department,
The top part of the riser is higher than the upper end of the product part, and has a basic shape with a sphericity of 0.91 or more and less than 1.00 by sandwiching a cylindrical body from the height direction between halved spheres. It is characterized by being

Comparing a spherical riser with a cylindrical riser, which has been common until now, when both have the same volume, the spherical riser 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 employ a spherical basic shape as the shape of the riser, it may not be possible due to the positional relationship described above. Alternatively, depending on the shape of the product, it may be desired to increase the height of the riser to achieve the riser effect. In these cases, the present inventors have devised to determine the shape of the riser using an index such as "sphericity" represented by "surface area of a true sphere having the same volume as the riser/surface area of the riser". rice field. As a common cylindrical riser, a riser having a height of 1.75 times the diameter is known. In order to increase the value of the modulus (volume of the riser/surface area of the riser) while keeping the volume below the same as that of a general cylindrical riser, and to improve heat retention as a riser, in other words, the effect of the riser. found that the basic shape of the riser should be a basic shape that utilizes a spherical shape, although it is not spherical.

The feeder head is used by appropriately modifying and deforming the basic shape so that it can be easily used as a mold or casting model. For example, appropriate draft angle, corner R, corner R, etc. are added for mold release, or a conical hole or V groove is provided at the top of the feeder to induce shrinkage of the top of the feeder. A score may be provided, or a part of the riser shape may be shaved or surplus thickness may be added depending on the relationship with the product part. In some cases, a rod-shaped portion having a smaller diameter or width than the diameter or width of the feeder may be additionally provided to provide a melt head (melt pressure) on the basic shape of the feeder. However, the basic shape of the riser is evident from its shape. Therefore, the basic shape of the riser in the above-mentioned casting is also used after being appropriately modified and deformed.

The riser may be provided between the sprue or the runner and the neck. Also, the riser may be a so-called lifting riser.

The necks are sometimes referred to as weirs. That is, the neck portion may be a weir connecting the riser and the product portion, or may be a weir connecting the runner and the product portion.

In addition, in the above casting,
The riser may have a basic shape in which a cylindrical body is sandwiched in the height direction between halved spheres.

The sphere referred to here is not limited to a perfect sphere, and may be, for example, an ellipsoid. Also, the cylindrical body is not limited to one having a perfect circular cross-sectional shape along the direction orthogonal to the height direction. Further, the cylindrical body may have a shape provided with a draft angle.

Further, the riser has a first hemispherical portion on the receiving side of the sprue, a second hemispherical portion opposite to the first hemispherical portion, and a cylinder provided between the first hemispherical portion and the second hemispherical portion. It may have a part.

Further, the product part may be provided below the top of the riser, and the receiving port of the sprue may be provided above the top of the riser.

In addition, in the above casting,
The riser may have an elliptical or rounded rectangular cross-sectional shape along a direction perpendicular to the height direction.

The rounded rectangle referred to here is a shape consisting of two parallel lines of equal length and two semicircles, and is a shape that is often used in athletics stadiums (tracks).

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

Further, both the first hemispherical portion and the second hemispherical portion have an elliptical or rounded rectangular cross-sectional shape along the direction orthogonal to the height direction.

The longitudinal direction of the ellipse or rectangle with rounded corners is the direction extended using the empty space.

Further, the riser may have a basic shape in which spherical parts obtained by dividing a spherical body are dispersedly arranged.

The first template that solves the above object is
a sprue forming space;
a runner-forming space;
a riser forming space;
a product part forming space;
a neck portion forming space connected to the product portion forming space;
The feeder forming space cannot take a spherical basic spatial shape due to the positional relationship with at least one of the sprue forming space, the runner forming space, the product forming space, and the neck forming space. A space for casting a riser having a basic shape with a sphericity of 0.91 or more and less than 1.00 in the state, and a cylinder body sandwiched from the height direction between halves of a sphere. , a first hemispherical space on the upper side, a second hemispherical space on the lower side, and a columnar space provided between the first hemispherical space and the second hemispherical space,
A parting surface is provided at a boundary between the cylindrical space and the second hemispherical space .

A second template that solves the above object is
a sprue forming space;
a riser forming space;
and a product part forming space,
The top of the feeder forming space is located higher than the upper end of the product forming space, and has a basic space shape with a sphericity of 0.91 or more and less than 1.00 , and a cylinder between halves of a sphere A space for casting a feeder head having a basic shape sandwiching the body from the height direction, comprising a first hemispherical space on the upper side, a second hemispherical space on the lower side, the first hemispherical space and the A space in which a columnar space is provided between two hemisphere spaces,
A parting surface is provided at a boundary between the cylindrical space and the second hemispherical space .

It may be a first mold, a second mold, a sand mold, or a metal mold. Moreover, it may be a mold for cast iron, or a mold for non-ferrous metals such as aluminum alloys.

Whether it is the first mold or the second mold, it can be used for horizontal casting in which the pouring direction and the direction of the parting surface are in a perpendicular relationship, or the relationship is in a parallel relationship. It can also be used for vertical casting in .

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

The product part forming space is provided below the top of the feeder forming space, and the upper end of the gate forming space is provided above the top of the feeder forming space. is preferred.

Further, the riser forming space may have a basic shape in which spaces of spherical portions obtained by dividing a spherical body are dispersedly arranged.

The casting method to solve the above purpose is
A first step of pouring molten metal into the mold;
and a second step of removing the casting from the mold into which the molten metal has been poured.

The casting removed in the second step corresponds to the casting that solves the above object.

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to provide a casting having a riser that can exhibit a riser effect while suppressing a decrease in casting yield, a mold for casting the casting, and a casting method using the mold. .

It is a figure which shows the casting of eight pieces which provided eight product parts with respect to one sprue. 1 shows a casting corresponding to one embodiment of the present invention; FIG. It is a figure which shows the neck part which connects one riser, one product part, and the riser and product part which are shown in FIG. Figure 3 is a cross-sectional view of a mold for casting the casting shown in Figure 2; FIG. 10 is a view showing the periphery of the casting in Example 2. FIG. It is a figure which shows the circumference of the riser of the casting in Example 3. FIG. FIG. 10 is a view showing the periphery of the casting in Example 4. FIG. FIG. 10 is a view showing the periphery of the casting in Example 5. FIG. It is a figure which shows the circumference|surroundings of the riser of the casting in Example 6. FIG. It is a figure which shows the circumference of the riser of the casting in a comparative example.

BEST MODE FOR CARRYING OUT THE INVENTION 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.

As in 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 seen from the side of the sprue (see FIG. 4) of the sprue not shown here.

The casting C shown in FIG. 2(a) is provided with eight product portions C4, one runner C2, four risers C3, and a neck portion C5 connecting the riser C3 and the product portion C4. there is The neck portion C5 may also be referred to as a weir. In addition, a connecting portion C21 with a sprue bottom (see FIG. 4) of a sprue (not shown) is shown at the center in the extending direction of one runner C2 extending in the horizontal direction of the figure.

As shown in FIG. 2(a), a product portion C4 is provided across a riser C3. That is, two product portions C4 are connected to one riser C3 via neck portions C5 at positions facing each other by 180°. The arrow shown in FIG. 2(a) indicates the direction connecting two product sections C4 provided for one riser C3.

FIG. 2(b) is a side view. Originally, this side view should show the product portion C4 on the left and right sides of the riser C3, but the product portion C4 is omitted in FIG. 2(b). In addition, in FIG. 2(b), a one-dot chain line is shown so as to pass through the height direction center of the riser C3. This dashed dotted line is a line representing a parting plane (the same applies to the following drawings). The casting C shown in FIG. 2(a) is cast by so-called horizontal casting, but may be cast by vertical casting.

FIG. 3 is a view showing one riser, one product section, and a neck section connecting the riser and the product section shown in FIG. That is, FIG. 3 shows the periphery of the riser, the front view is shown in FIG. 3(b), and the plan view is shown in FIG. 3(a). This plan view is also a view from the side of the sprue socket (see FIG. 4), not shown. A right side view is shown in FIG. 3(c).

The product portion C4 has a hat-like shape with a through hole C42 provided in an upper surface C41, has a flange portion C43, and tapers upward. One end of the neck portion C5 is connected to the flange portion C43.

The riser C3 has a basic shape in which a cylindrical body with a height of 40 mm is sandwiched between two halves of a sphere with a diameter of 80 mm. That is, as shown in FIG. 3B, it has a first hemispherical portion C31, a second hemispherical portion C32, and a cylindrical portion C33 between the first hemispherical portion C31 and the second hemispherical portion C32. The first hemispherical portion C31 is a hemispherical portion on the side of the sprue (not shown), and the second hemispherical portion C32 is the hemispherical portion on the opposite side. The maximum diameter of the first hemispherical portion C31 and the second hemispherical portion C32 is 80 mm, and the diameter of the cylindrical portion C33 is also 80 mm. Also, the height of the columnar portion C33 is half the height of the diameter. Casting C is provided with a draft angle. The columnar portion C33 is located above the parting plane indicated by the dashed line, and considering the draft angle, the diameter of the lower end of the columnar portion C33 is the largest. This riser C3 is 40 mm higher than a true sphere with a diameter of 80 mm.

Note that the sphere is not limited to a perfect sphere, and may be an ellipsoid, for example. Also, the cylindrical portion C33 is not limited to having a perfect circular cross-sectional shape along the direction orthogonal to the height direction. For example, the cross-sectional shape may be an ellipse or a rectangle with rounded corners. The rounded rectangle referred to here is a shape consisting of two parallel lines of equal length and two semicircles, and is a shape often found in athletic fields (tracks) (same below).

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

Furthermore, the product portion C4 shown in FIG. 3 protrudes upward from the top portion C3t of the riser C3, but the upper end of the product portion C4 (here, the upper surface C41) is provided below the top portion C3t of the riser C3. It may have been

4 is a cross-sectional view of a mold for casting the casting shown in FIG. 2; FIG. This cross-sectional view is a cross-sectional view when viewed from the same side direction as FIG. 2(b).

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

The riser forming space M3 is a space for casting a riser having a basic shape in which a cylindrical body is sandwiched from the height direction between halved spheres, and is a first hemispherical space M31 on the upper side and a first hemispherical space M31 on the lower side. It is a space in which a cylindrical space M33 is provided between the second hemispherical space M32 and the first hemispherical space M31 and the second hemispherical 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 hemispherical space M32 (see the two-dot chain line in FIG. 4). may be present, or may be below the boundary.

Although the product part forming space M4 shown in FIG. 4 protrudes upward from the top of the feeder forming space M2, the upper end of the product forming space M4 is provided below the top of the feeder forming space M2. It may have been

In order to cast the casting C shown in FIG. 2, a first step of pouring molten cast iron into the mold M shown in FIG. 4 and a second step of removing the casting C from the mold M into which the molten metal is poured are performed. do.

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

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

Table 1 shows the volume, surface area, and modulus (volume of the riser/surface area of the riser) of the vertically elongated spherical (1) riser C3.

図２に示すように押湯Ｃ３の半径方向には、製品部Ｃ４であったり、隣の押湯Ｃ３が配置されており、特に図２（ａ）に示す矢印方向にはスペース的に余裕がない。縦長球状（１）の押湯Ｃ３は、真球状の押湯を高さ方向（上下方向）にのみ延ばしたものである。直径が同じ８０ｍｍの真球状の押湯の体積は、２６８０８３ｍｍ^３である。縦長球状（１）の押湯Ｃ３は、直径が同じ真球状の押湯に比べて、体積が１．７５倍になっている。

As shown in FIG. 2, in the radial direction of the riser C3, the product portion C4 and the adjacent riser C3 are arranged, and in particular, there is a space in the direction of the arrow shown in FIG. Absent. The vertically elongated spherical (1) riser C3 is obtained by extending a true spherical riser only in the height direction (vertical direction). The volume of a true spherical riser with the same diameter of 80 mm is 268083 mm ³ . The tall spherical (1) riser C3 has a volume 1.75 times that of the true spherical riser having the same diameter.

In practice, the feeder head is used by appropriately modifying and deforming its basic shape so that it can be easily used as a casting mold or casting model. For example, appropriate draft angle, corner R, corner R, etc. are added for mold release, or a conical hole or V groove is provided at the top of the feeder to induce shrinkage of the top of the feeder. A score may be provided, or a part of the riser shape may be shaved or surplus thickness may be added depending on the relationship with the product part. In some cases, a rod-shaped portion having a smaller diameter or width than the diameter or width of the feeder may be additionally provided to provide a melt head (melt pressure) on the basic shape of the feeder. In the riser C3 shown in FIG. 3, these modified deformations are omitted from the drawing, and these modified deformations are not taken into account in the calculation of the volume and surface area. This also applies to Example 2 onwards and Comparative Examples.

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

Furthermore, when the modulus per unit volume was taken as feeder head efficiency, it was 0.332×10 ⁻⁴ mm ² .
(Example 2)
FIG. 5 is a diagram showing the surroundings of the casting in Example 2. FIG. In FIG. 5, as in FIG. 3, the front view is shown in FIG. 5(b) and the plan view is shown in FIG. 5(a). A right side view is shown in FIG. 5(c).

In the following description, constituent elements having the same names as those of the constituent elements described so far are given the same reference numerals as those given so far. In addition, descriptions of matters overlapping with the matters described so far may be omitted.

The riser C3 shown in FIG. 5 is a riser provided in the casting cast by the eight-piece horizontal casting described with reference to FIG. 2, and is the same product section as the product section shown in FIGS. Molten metal is supplied to C4 through a neck portion C5 which is the same as the neck portion shown in FIGS.

The riser C3 shown in FIG. 5 has a basic shape in which a cylindrical body with a height of 60 mm is sandwiched between two halves of a sphere with a diameter of 80 mm. That is, as shown in FIG. 5B, the riser C3 in Example 2 includes a first hemispherical portion C31, a second hemispherical portion C32, and a cylinder sandwiched between the first hemispherical portion C31 and the second hemispherical portion C32. It has a portion C33, and the height of the columnar portion C33 is 20 mm higher than the tall spherical (1) riser in Example 1. Hereinafter, the riser C3 shown in FIG. 5, that is, the riser C3 in Example 2 is referred to as a vertically elongated spherical (2) riser. The height (60 mm) of the cylindrical portion C33 of the vertically elongated spherical (2) riser C3 corresponds to 0.75 times the diameter (D) of 80 mm. In addition, the height (H) of the whole riser C3, which is elongated spherically (2), is 140 mm.

Table 1 shows the volume, surface area, and modulus (volume of riser/surface area of riser) of the vertically elongated spherical (2) riser C3.

Like the vertically long spherical (1) riser C3, the vertically long spherical (2) riser C3 extends only in the height direction (vertical direction), and the vertically long spherical (2) riser C3 , the volume is 2.13 times that of a spherical feeder with the same diameter of 80 mm.

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

Furthermore, when the modulus per unit volume was taken as feeder head efficiency, it was 0.284×10 ⁻⁴ mm ² .
(Example 3)
FIG. 6 is a diagram showing the periphery of the casting in Example 3. FIG. In FIG. 6, as in FIG. 3, the front view is shown in FIG. 6(b) and the plan view is shown in FIG. 6(a). A right side view is shown in FIG. 6(c).

The riser C3 shown in FIG. 6 is also a riser provided in a casting cast by the horizontal casting of 8 pieces described with reference to FIG. The molten metal is supplied through the same neck portion C5 as the neck portion shown in FIGS. 2 and 3 to the product portion C4 which is the same as the product portion shown in FIGS.

The riser C3 shown in FIG. 6 has a basic shape in which a cylindrical body with a height of 86.6 mm is sandwiched in the height direction between halves of a sphere with a diameter of 80 mm. That is, as shown in FIG. 6B, the riser C3 in Example 3 also has a first hemispherical portion C31, a second hemispherical portion C32, and a cylindrical portion C33, and has a vertically oblong spherical shape (1) in Example 1 The height of the cylindrical portion C33 is 46.6 mm higher than the riser. Hereinafter, the riser C3 shown in FIG. 6, that is, the riser C3 in Example 3 is referred to as a vertically elongated spherical (3) riser. The height (86.6 mm) of the cylindrical portion C33 of the vertically elongated spherical (3) riser C3 corresponds to 1.08 times the diameter (D) of 80 mm. Moreover, the height (H) of the whole riser C3, which is elongated spherically (3), is 166.6 mm.

Note that the sphere is not limited to a perfect sphere, and may be an ellipsoid, for example. Also, the cylindrical portion C33 is not limited to having a perfect circular cross-sectional shape along the direction perpendicular to the height direction. For example, the cross-sectional shape may be an ellipse or a rectangle with rounded corners.

Moreover, the riser C3 shown in FIG. 6 may also be provided between the neck portion C5 and the sprue (not shown), or may be a so-called lifting riser.

Table 1 shows the volume, surface area, and modulus (volume of riser/surface area of riser) of the vertically elongated spherical (3) riser C3.

Similarly to the vertically elongated spherical (3) riser C3, the spherical riser C3 extends only in the height direction (vertical direction), and the top C3t of the riser C3 shown in FIG. protrudes above the upper end of the product portion C4 (here, the upper surface C41). Depending on the shape of the product, if the top of the riser is lower than the height of the top of the product, the pressure of the molten metal at the top of the product will be low, so the top of the product will be pulled before the top of the product (solidification). shrinkage occurs), and shrinkage cavities may occur in the product. In this case, even if there is space in the radial direction of the riser, the volume of the riser is not increased in the radial direction of the riser, and the volume of the riser is increased only in the upward direction. That is, even in a state where the basic shape of the riser can be a spherical basic shape depending on the positional relationship with at least one of the sprue, runner, product part, and neck part, the diameter of the riser is increased. It increases the volume of the riser only in the upward direction, instead of increasing the volume of the entire riser. In this way, the top portion C3t of the riser C3 is positioned higher than the upper end of the product portion C4. The same applies to the casting mold, and the top of the feeder forming space is positioned higher than the upper end of the product forming space. By doing so, it becomes possible to draw from the top C3t of the riser C3. The vertically elongated spherical (3) riser C3 has a volume 2.62 times that of the true spherical riser with the same diameter of 80 mm, but the height of the vertically elongated spherical (3) riser C3 The volume is reduced to 0.3 times or less compared to a true spherical riser with a diameter of 166.6 mm.

In addition, the diameter of a true sphere having the same volume as the vertically oblong spherical (3) riser C3 (equal volume sphere diameter) and the surface area of a true sphere (equal volume sphere surface area) obtained using that diameter are obtained, and further that Using the equivalent volume spherical surface area, the sphericity represented by "the equivalent volume spherical surface area/surface area of vertically elongated spherical (3) riser C3" was obtained. These values are also shown in Table 1. The sphericity of the vertically elongated spherical (3) riser is 0.913, which is greater than or equal to 0.91.

Furthermore, when the modulus per unit volume was taken as feeder head efficiency, it was 0.239×10 ⁻⁴ mm ² .
(Example 4)
FIG. 7 is a diagram showing the periphery of the casting in Example 4. FIG. In FIG. 7, as in FIG. 3, the front view is shown in FIG. 7(b) and the plan view is shown in FIG. 7(a). A right side view is shown in FIG. 7(c).

The riser C3 shown in FIG. 7 is also a riser provided in a casting cast by the horizontal casting of 8 pieces described using FIG. The molten metal is supplied through the same neck portion C5 as the neck portion shown in FIGS. 2 and 3 to the product portion C4 which is the same as the product portion shown in FIGS.

The riser C3 shown in FIG. 7 has a basic shape in which a cylindrical body with a height of 12.3 mm is sandwiched in the height direction between halves of a sphere with a diameter of 88 mm. That is, as shown in FIG. 7B, the riser C3 in Example 4 also has a first hemispherical portion C31, a second hemispherical portion C32, and a cylindrical portion C33, and has a vertically oblong spherical shape (1) in Example 1 8 mm larger in the radial direction than the feeder head, and the height of the cylindrical portion C33 is 27.7 mm lower. Hereinafter, the riser C3 shown in FIG. 7, that is, the riser C3 in Example 4 is referred to as a vertically elongated spherical (4) riser. The height (12.3 mm) of the cylindrical portion C33 of the vertically elongated spherical (4) riser C3 corresponds to 0.14 times the diameter (D) of 88 mm. Moreover, the height (H) of the whole riser C3, which is elongated spherically (4), is 100.3 mm.

Table 1 shows the volume, surface area, and modulus (volume of riser/surface area of riser) of the vertically elongated spherical (4) riser C3.

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

In addition, the diameter of a true sphere having the same volume as the vertically oblong spherical (4) riser C3 (equal volume sphere diameter) and the surface area of a true sphere obtained using that diameter (equal volume sphere surface area) are obtained, and further Using the iso-volume spherical surface area, the sphericity represented by "equi-volume spherical surface area/surface area of vertically elongated spherical (4) riser C3" was determined. These values are also shown in Table 1. The sphericity of the vertically elongated spherical (4) riser C3 is 0.996, which is higher than the vertically elongated spherical (1) riser and closer to a perfect sphere. In the case of a true sphere, the degree of sphericity is 1.

Furthermore, when the modulus per unit volume was considered as the feeder head efficiency, it was 0.361×10 ⁻⁴ mm ² .
(Example 5)
FIG. 8 is a view showing the periphery of the casting in Example 5. FIG. In FIG. 8, as in FIG. 3, the front view is shown in FIG. 8(b) and the plan view is shown in FIG. 8(a). A right side view is shown in FIG. 8(c).

The riser C3 shown in FIG. 8 is also a riser provided in a casting cast by the eight-injection horizontal casting described with reference to FIG. The molten metal is supplied to the product portion C4, which is the same as the product portion shown in FIG. 3, through the neck portion C5, which is the same as the neck portion shown in FIGS.

The riser C3 shown in FIG. 8 is different in shape from the risers in the previous embodiments. That is, it has a basic shape in which an intermediate body with a height of 60 mm is sandwiched between two halves of a sphere with a diameter of 80 mm. , the shape of a rounded rectangle, consisting of two parallel lines of equal length and two semicircular arcs of radius 40 mm. That is, a true sphere with a diameter (D) of 80 mm is crushed in the direction of the arrow shown in FIG. 2(a). Also, the intermediate body having a height of 60 mm has a rounded rectangular upper surface and a lower surface. The cross-sectional shape of this intermediate body along the parting plane indicated by the one-dot chain line is also a rectangular shape with rounded corners. Further, as shown in FIG. 8(c), the riser C3 looks like a rectangle with rounded corners (an oval shape) when viewed from the side (in the direction of the arrow in FIG. 2). Hereinafter, the riser C3 shown in FIG. 8, that is, the riser C3 in Example 5 will be referred to as a riser having a vertical and horizontal spherical shape (1). The height (H) of the riser C3, which has a vertically and horizontally elongated spherical shape (1), is 140 mm, and the length in the width direction (corresponding to the left-right direction in FIG. 8(c)) perpendicular to the arrow shown in FIG. It is 1.25 times wider than the vertically elongated spherical (3) riser C3 shown in FIG.

The vertical and horizontal spherical (1) riser C3 has a shape in which a spherical riser is crushed into an oval shape in the direction of the arrow shown in FIG. 2(a). It expands in the width direction perpendicular to the direction, increasing the volume of the riser.

6, the top portion C3t of the top portion C3t of the top portion C3 of the top portion C3 of the top portion C3 of the top portion C3 of the top portion C4 of the product portion C4 may be extended to protrude above the top portion C41 of the product portion C4. The same applies to the casting mold, and the top of the feeder forming space may be positioned 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 riser C3 having a vertically and horizontally elongated spherical shape (1).

In addition, the diameter of a true sphere having the same volume as the riser C3 (1), and the surface area of the true sphere obtained using the diameter (equal volume spherical surface area), Using the equivalent volume spherical surface area, the sphericity represented by "equal volume spherical surface area/surface area of riser C3 of vertical and horizontal spherical shape (1)" was determined. These values are also shown in Table 1. The sphericity of the feeder head C3, which has an elongated spherical shape (1), was 0.960.

Furthermore, when the modulus per unit volume was considered as the feeder head efficiency, it was 0.283×10 ⁻⁴ mm ² .
(Example 6)
FIG. 9 is a view showing the periphery of the casting in Example 6. FIG. In FIG. 9, as in FIG. 3, the front view is shown in FIG. 9(b) and the plan view is shown in FIG. 9(a). A right side view is shown in FIG. 9(c).

The riser C3 shown in FIG. 9 is also a riser provided in a casting cast by the eight-injection horizontal injection casting described with reference to FIG. The molten metal is supplied to the product portion C4, which is the same as the product portion shown in FIG. 3, through the neck portion C5, which is the same as the neck portion shown in FIGS.

The riser C3 shown in FIG. 9 is also the same as the vertically and horizontally elongated spherical riser (1) shown in FIG. It has a basic shape. Also in this Example 6, the sphere with a diameter of 80 mm has a cross-sectional shape that is not a perfect circle but a rounded rectangle, and has a shape consisting of two parallel lines of equal length and two semicircular arcs with a radius of 40 mm. . That is, a true sphere with a diameter (D) of 80 mm is crushed in the direction of the arrow shown in FIG. 2(a). Also, the intermediate body having a height of 60 mm has a rounded rectangular upper surface and a lower surface. The cross-sectional shape of this intermediate body along the parting plane indicated by the one-dot chain line is also a rectangular shape with rounded corners. Also, as shown in FIG. 9(c), the riser C3 shown in FIG. 9 looks like a rectangle with rounded corners even when viewed from the side (in the direction of the arrow shown in FIG. 2). Hereinafter, the riser C3 shown in FIG. 9, that is, the riser C3 in Example 6 will be referred to as a riser having a vertical and horizontal spherical shape (2). The height (H) of the riser C3, which has a vertically and horizontally elongated spherical shape (2), is 140 mm, and the length in the width direction perpendicular to the arrow shown in FIG. It is 1.5 times wider than the vertically elongated spherical (3) riser C3 shown in FIG.

The vertically and horizontally elongated spherical (2) riser C3 has a shape in which a true spherical riser is crushed in the direction of the arrow shown in FIG. It expands in the width direction orthogonal to the direction of the arrow shown in (a), further increasing the volume of the riser.

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 elongated spherical shape (2).

In addition, the diameter of a true sphere having the same volume as the riser C3 (2), and the surface area of the true sphere obtained using that diameter (equal volume spherical surface area), Using the equivalent volume spherical surface area, the sphericity represented by "equivalent volume spherical surface area/surface area of riser C3 of vertical and horizontal spherical shape (2)" was determined. These values are also shown in Table 1. The sphericity of the feeder head C3, which has an elongated spherical shape (2), was 0.955.

Furthermore, when the modulus per unit volume was taken as feeder head efficiency, it was 0.250×10 ⁻⁴ mm ² .
(Comparative example)
FIG. 10 is a diagram showing the surroundings of a casting in a comparative example. 10, as in FIG. 3, the front view is shown in FIG. 10(b) and the plan view is shown in FIG. 10(a). A right side view is shown in FIG. 10(c).

Hereinafter, the same reference numerals as those used in FIG. 1 are attached to constituent elements having the same names as those of the constituent elements described in FIG. In addition, descriptions of matters overlapping with the matters described so far may be omitted.

The riser C3' shown in FIG. 10 is a riser provided in a casting cast by the eight-piece horizontal casting described with reference to FIG. 1, and is the same product as the product part shown in FIGS. Molten metal is supplied to the portion C4' through the same neck portion C5' as the neck portion shown in FIGS.

The riser C3' shown in FIG. 10 has a basic shape of a cylinder with a diameter (D) of 80 mm and a height (H) of 140 mm. The height of this riser C3' (140 mm) corresponds to 1.75 times the diameter of 80 mm. Hereinafter, the riser C3' shown in FIG. 10, that is, the riser C3' in the comparative example will be referred to as a columnar riser.

The volume, surface area, and modulus (volume of riser/surface area of riser) of this cylindrical riser C3' are also shown in Table 1 above.

In addition, the diameter of a true sphere having the same volume as the cylindrical riser C3' (equal volume sphere diameter) and the surface area of a true sphere obtained using that diameter (equal volume sphere surface area) are obtained, and the equal volume The spherical surface area was used to determine the sphericity expressed by "equal volume spherical surface area/surface area of cylindrical riser C3'". These values are also shown in Table 1. The sphericity of the cylindrical riser C3' was 0.846, below 0.91.

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

In order to produce a sound casting product without shrinkage cavity defects, it is necessary to compensate for the solidification shrinkage of the product part, and for that reason, it is necessary to continue replenishing the molten metal from the riser until the product part finishes solidifying. For this purpose, the solidification time of the feeder must be longer than the solidification time of the product part. The coagulation time t is proportional to the square of the modulus M from Kuvorinov's law in the following formula (1), and since the modulus M can be expressed as in the following formula (2), the modulus M is very important.
t=C・M ² Formula (1)
M=V/S Formula (2)
However, C is a coefficient, V is a volume, and S is a surface area.

However, as the volume of the riser increases, the modulus M also increases, and although the capability of the riser increases, the casting weight also increases. Therefore, it is not preferable in terms of casting yield (weight of product part/weight of casting). Therefore, as described above, the modulus of the riser per unit volume was obtained as the riser efficiency E. That is, the feeder head efficiency E is represented by the following formula (3).
E = M / V = S ^-1 Formula (3)
Conventional risers generally have a cylindrical shape with a height of 1.5 to 2 times the diameter. Therefore, the cylindrical riser with a height of 1.75 times the diameter shown in FIG. 10 represents a typical riser. Calculations using the above formulas (1) to (3) for a cylindrical riser whose height Hc is α times the diameter D are as follows.
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)} Equation (5)
Ec=Sc ⁻¹ =2D ⁻² /{π(2α+1)} Equation (6)
where Vc is the volume of the cylindrical feeder, Sc is the surface area of the cylindrical feeder, Mc is the modulus of the cylindrical feeder, and Ec is the feeder efficiency of the cylindrical feeder.

Next, a longitudinal spherical riser (for example, the risers of Examples 1 to 4) in which a cylindrical body is sandwiched from the height direction between halves of a sphere with the same diameter D as the diameter of the cylindrical riser is examined. do. First, assuming that the height Hs of the entire lengthwise spherical riser is β times the diameter D,
Hs = βD
is represented by The height of the sandwiched cylindrical body is Hs-D. Then, the volume Vs and the surface area Ss of the elongated spherical riser are represented by the following equations.
Vs=(π/6)×D ³ +(π/4)×D ² ×(Hs−D)=(π/12)×D ³ (3β−1) Equation (7)
Ss=πD ² +πD(Hs−D)=πβD ²
From the above formula (2), the modulus Ms of the vertically oblong spherical riser is represented by the following formula.
Ms=Vs/Ss={(π/12)×D ³ (3β−1)}/{πβD ² }=(D/12β)×(3β−1) Equation (8)
Further, the feeder head efficiency Es of the elongated spherical feeder head is represented by the following formula from the above formula (3).
Es=Ss ⁻¹ =(πβ) ⁻¹ ×D ⁻² Equation (9)
Next, an oblong spherical riser having a modulus Ms equivalent to the modulus Mc of the cylindrical riser will be examined.
Since Mc = Ms, using the above formulas (5) and (8),
αD/{2(2α+1)}=(D/12β)×(3β−1)
is established,
β=(2α+1)/3 Formula (10)
is required. This equation (10) defines a cylindrical feeder with a height Hc that is α times the diameter D and a height β times the diameter D that has a modulus Ms equal to the modulus Mc of the cylindrical riser. It is an equation that is established with a vertically elongated spherical riser having Hs.
From the above formula (7), the volume Vs of the vertically elongated spherical riser is
Vs=(π/12)×D ³ (3β−1)
and by substituting the above formula (10) into this,
Vs=(π/6)×αD ³
become.
Further, the volume Vc of the columnar riser is obtained from the above formula (4),
Vc=(π/4)×αD ³
become.
As a result of these
Vs/Vc={(π/6)×αD ³ }/{(π/4)×αD ³ }=2/3≈0.6667
It can be seen that a tall sphere with the same diameter and modulus as a cylindrical riser is always about 33% smaller in volume than a cylindrical riser, regardless of diameter or height.

In addition, when compared in terms of feeder head efficiency, the results are as follows.
The riser efficiency Ec of the columnar riser is obtained from the above formula (6) as follows:
Ec=2D ⁻² /{π(2α+1)}
The feeder head efficiency Es of the vertically elongated spherical feeder head is, from the above formula (9),
Es=(πβ) ⁻¹ ×D ⁻²
and substituting the above formula (10) into this,
Es=3D ⁻² /{π(2α+1)}
become.
As a result, the feeder efficiency ratio of the vertically elongated 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 elongated spherical riser has 1.5 times the riser efficiency of the cylindrical riser.

In addition, in the comparative example, a columnar riser whose height Hc is 1.75 times the diameter D,
α=1.75
and the sphericity of the cylindrical riser is calculated to be 0.846 as shown in Table 1. On the other hand, substituting α=1.75 into the above formula (10) yields
β=(2×1.75+1)/3=1.5
become. That is, the height of an oblong spherical feeder with a modulus Ms equal to the modulus Mc of a cylindrical feeder with a height Hc of 1.75 times the diameter D will be 1.5 times the diameter D. This vertically elongated spherical riser having a height Hs that is 1.5 times the diameter D becomes the vertically elongated spherical (1) riser C3 of Example 1, and when the sphericity is calculated, as shown in Table 1 becomes 0.968.

Therefore, it can be seen that the sphericity of the vertically elongated spherical riser is higher than that of the cylindrical riser when the cylindrical riser and the vertically elongated spherical riser have the same modulus.

Next, the columnar riser C3' of the comparative example, whose height is 1.75 times the diameter, is a representative example of the general riser as described above. Let's compare this cylindrical riser C3' with each example.

Comparing the riser C3 in Example 1 (longitudinally spherical (1) riser C3) with the cylindrical riser C3', the modulus is the same. On the other hand, it can be seen that the sphericity of the riser C3 in Example 1 is higher than that of the cylindrical riser C3'. Also, when looking at the riser efficiency, it can be seen that the riser C3 in Example 1 is 1.5 times higher than the cylindrical riser C3'. Furthermore, looking at the volume of the riser, it can be seen that the riser C3 in Example 1 is 0.667 times as large as the cylindrical riser C3'.

By using the riser C3 of Example 1, the sphericity is higher than that of the cylindrical riser C3', and the modulus is the same, that is, the heat retention as a riser, in other words, the riser effect is equivalent. The feeder efficiency can be increased by a factor of 1.5 while the volume can be reduced by 33% relative to the cylindrical feeder C3'.

The modulus of the riser C3 in Example 2 (longitudinally spherical (2) riser C3) is 1.04 times that of the cylindrical riser C3'. Further, the sphericity of the riser C3 in Example 2 is higher than that of the cylindrical riser C3'. Also, when looking at the riser efficiency, it can be seen that the riser C3 in Example 2 is 1.29 times higher than the cylindrical riser C3'. Furthermore, looking at the volume of the riser, it can be seen that the riser C3 in Example 2 is 0.810 times as large as the cylindrical riser C3'.

By using the riser C3 of Example 2, the sphericity is higher than that of the cylindrical riser C3', and the modulus is also increased, so that the heat retention as a riser is improved. , From 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 longer, while the volume is increased by the cylindrical feeder C3 ' can be reduced by 19%.

The riser C3 in Example 3 (longitudinally spherical (3) riser C3) has a modulus 1.08 times that of the cylindrical riser C3'. Also, looking at the feeder head efficiency, although the feeder head C3 in Example 3 is inferior to the feeder head C3 in Example 2, it is found to be 1.08 times as high as the cylindrical feeder C3'. Also, when looking at the volume of the riser, the riser C3 in Example 3 has approximately the same volume as the cylindrical riser C3'. The sphericity of the riser C3 of Example 3 is 0.913, which is lower than that of the riser C3 of Example 2, but sufficiently higher than that of the cylindrical riser C3'.

By using the riser C3 of Example 3, the sphericity is higher than that of the cylindrical riser C3', and the volume is about the same as that of the cylindrical riser C3', but the modulus is increased. The heat retention as a riser is improved, and the riser of Example 3 has a solidification time that is 1.17 times longer than that of the cylindrical riser C3', and the riser efficiency is also improved.

The riser in Example 4 (longitudinally spherical (4) riser C3) has a modulus comparable to that of the cylindrical riser C3'. Further, the sphericity of the riser C3 in Example 4 is much higher than that of the cylindrical riser C3'. Also, when looking at the riser efficiency, it can be seen that the riser C3 in Example 4 is 1.63 times as high as the cylindrical riser C3'. Furthermore, when looking at the volume of the riser, it can be seen that the volume of the riser C3 in Example 4 is 0.614 times the volume of the columnar riser C3'.

By using the feeder C3 of Example 4, the sphericity is much higher than that of the cylindrical feeder C3', and even though the modulus is the same, the feeder efficiency is increased by 1.63 times. , the volume can also be reduced by 39% relative to the cylindrical riser C3'.

The riser C3 in Example 5 (longitudinally and horizontally elongated spherical shape (1) riser C3) has a modulus 1.07 times that of the cylindrical riser C3'. Further, the sphericity of the riser C3 in Example 5 is higher than that of the cylindrical riser C3'. In addition, when looking at the riser efficiency, it can be seen that the riser C3 in Example 5 is 1.28 times as high as the cylindrical riser C3'. Furthermore, looking at the volume of the riser, it can be seen that the riser C3 in Example 5 is 0.833 times as large as the cylindrical riser C3'.

By using the riser C3 of Example 5, the sphericity is higher than that of the cylindrical riser C3', and the modulus is also increased, so that the heat retention as a riser is improved. , the solidification time is extended by a factor of 1.14 over the cylindrical feeder C3′, and the feeder efficiency is increased by a factor of 1.28, while the volume is reduced by 17% over the cylindrical feeder C3′. can do.

The riser C3 in Example 6 (longitudinally and horizontally elongated spherical (2) riser C3) has a modulus as high as 1.13 times that of the cylindrical riser C3'. Also, the sphericity of the riser C3 in Example 6 is higher than that of the cylindrical riser C3'. Furthermore, looking at the riser efficiency, it can be seen that the riser C3 in Example 6 is 1.13 times as high as the cylindrical riser C3'. Also, when looking at the volume of the riser, the riser C3 in Example 6 has the same volume as the cylindrical riser C3'.

By using the riser C3 of Example 6, the sphericity is higher than that of the cylindrical riser C3', and the volume is the same as that of the cylindrical riser C3', but the modulus is increased. The heat retention as a riser is improved, and the riser of Example 6 has a solidification time that is 1.28 times longer than that of the cylindrical riser C3', and the riser efficiency is also improved.

Here, when the volume of a certain riser 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 volume (V) of a certain riser is Va = V = (π / 6) Da ³ , where Da is the diameter, Its surface area (Sa) becomes Sa= ^πDa2 . As a result, the modulus (Ma) of an equivolume sphere is Ma=Da/6. As a result, the relationship between the volume (Va) and the modulus (Ma) of the isovolumetric sphere is Va=V=(π/6)Da ³ =(π/6)(6Ma) ³ =36πMa ³ , and Ma=( V/36π) can be rewritten as ^1/3 .

The volume (Vb) of a true sphere (equal modulus sphere) having the same modulus (Mb) as the modulus (M) of a certain riser is Vb = (π/6) Db ³ , where Db is the diameter. , its surface area (Sb) becomes Sb= ^πDb2 . As a result, the modulus (Mb) of the equimodulus sphere is Mb=M=Db/6. As a result, the relationship between the volume (Vb) and the modulus (Mb) of the equimodulus sphere is Vb=(π/6)Db ³ =(π/6)(6M) ³ =36πM ³ and M=(Vb/ 36π) can be rewritten as ^1/3 .

Then, the sphericity (ψ) of a certain riser is “the surface area of an equivolume sphere (Sa)/the surface area of a certain riser (S)”, ψ = Sa / (V / M) = (Sa・M)/V=(Sa·M)/(Sa·Ma)=M/Ma=[(Vb/36π) ^1/3 ]/[(V/36π) ^1/3 ]=(Vb/V) ¹ can be rewritten as ^/3 . As a result, the ratio (Vb/V) between the volume (V) of the certain riser and the volume (Vb) of the equimodulus sphere is Vb/V = ³ when expressed using the sphericity (ψ). .

If the certain riser has a sphericity (ψ) of 0.91, the volume (v) of the certain riser is expressed as V=Vb/ψ ³ =1.33Vb . As a result, when the sphericity (ψ) is less than 0.91, the volume increases by more than 33% with respect to the volume (Vb) of the equimodulus sphere, which is an ideal spherical shape. end up An increase in volume of more than 1/3 cannot be overlooked, resulting in a significant drop in casting yield.

In addition, of the riser C3 of Example 3 and the riser C3 of Example 6, which had the same volume as the columnar riser C3', the riser C3 of Example 3 was extended only in the height direction. In contrast, the riser C3 of Example 6 extends not only in the height direction but also in the width direction. In the riser C3 of Example 6, although it is extended in two directions, the extent of extension is relatively small, while in the riser C3 of Example 3, although it is extended in one direction, the extent of extension was relatively large, resulting in a difference in sphericity. From this, if it is assumed that the volume of the columnar riser C3' is about the same as that of the riser C3', the limit for extending the riser in one direction can be controlled by the sphericity, and the limit value is found to be 0.91.

In addition, the basic shape of the riser is not limited to a basic shape in which spherical parts obtained by dividing a sphere are dispersed, such as a vertically elongated spherical shape and a vertically and horizontally elongated spherical shape, and the sphericity is 0.91 or more and less than 1.00. Any basic shape is acceptable. This also applies to the basic shape of the riser forming space.

According to the riser C3 of each example, it can be seen that the sphericity is as high as 0.91 or more, and the heat retention of the riser is equal to or higher than that of the columnar riser C3' of the comparative example. As a result, it has a suitable modulus corresponding to the product portion C4 and a high sphericity of 0.91 or more, so that a sufficient riser effect can be obtained with a small volume riser. Therefore, even if a spherical basic shape cannot be adopted as the basic shape of the riser, the riser effect can be exhibited without lowering the casting yield. As a result, the amount of molten metal required for the feeder head can be greatly reduced, and the power consumption for melting and the molten metal processing cost can be greatly reduced. In addition, it can greatly contribute to the reduction of _CO2 .

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

Claims (8)

Yuguchi and
Yumichi and
pusher and
the product department,
a neck portion connected to the product portion;
In a state in which the riser cannot assume a spherical basic shape due to the positional relationship with at least one of the sprue, the runner, the product portion, and the neck portion, a cylinder is formed between halves of a sphere. A casting characterized by having a basic shape with a sphericity of 0.91 or more and less than 1.00 by sandwiching a body from the height direction . Yuguchi and
pusher and
with the product department,
The top part of the riser is higher than the upper end of the product part, and has a basic shape with a sphericity of 0.91 or more and less than 1.00 by sandwiching a cylindrical body from the height direction between halved spheres. A casting characterized by being made of 3. The casting according to claim 1 , wherein said riser has an elliptical or rounded rectangular cross-sectional shape along a direction orthogonal to the height direction . The sprue is one,
4. The casting according to any one of claims 1 to 3, wherein a plurality of said product parts are provided for one said sprue. a sprue forming space;
a runner-forming space;
a riser forming space;
a product part forming space;
a neck portion forming space connected to the product portion forming space;
The feeder forming space cannot take a spherical basic spatial shape due to the positional relationship with at least one of the sprue forming space, the runner forming space, the product forming space, and the neck forming space. A space for casting a riser having a basic shape with a sphericity of 0.91 or more and less than 1.00 in the state, and a cylinder body sandwiched from the height direction between halves of a sphere. , a first hemispherical space on the upper side, a second hemispherical space on the lower side, and a columnar space provided between the first hemispherical space and the second hemispherical space,
A mold , wherein a parting surface is provided at a boundary between the cylindrical space and the second hemispherical space . a sprue forming space;
a riser forming space;
and a product part forming space,
The top of the feeder forming space is located higher than the upper end of the product forming space, and has a basic space shape with a sphericity of 0.91 or more and less than 1.00 , and a cylinder between halves of a sphere A space for casting a feeder head having a basic shape sandwiching the body from the height direction, comprising a first hemispherical space on the upper side, a second hemispherical space on the lower side, the first hemispherical space and the A space in which a columnar space is provided between two hemisphere spaces,
A mold , wherein a parting surface is provided at a boundary between the cylindrical space and the second hemispherical space . The sprue forming space is one,
7. The mold according to claim 5, wherein a plurality of said product portion forming spaces are provided for one said sprue forming space. A first step of pouring molten metal into the mold according to any one of claims 5 to 7;
and a second step of removing the casting from the mold into which the molten metal has been poured.

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