JP7506199B2 - Die Casting Molds - Google Patents

Description

The present invention relates to a die casting mold having a cooling passage.

The mold is heated by the molten metal supplied to the cavity, which serves as the heat source. For this reason, cooling passages are provided inside the mold to cool the mold. Cooling water is supplied to the cooling passages. The mold is cooled by the cooling water flowing through the cooling passages.

The following Patent Document 1 discloses a configuration in which a convex mold is cylindrical and its internal space serves as a cooling passage. The cooling passage is formed linearly along the axial direction of the cylindrical mold and reaches close to the tip of the mold. A coolant is supplied to the cooling passage from the base end of the mold. However, since the cooling passage ends at the tip of the mold, it is difficult for the coolant to circulate, and efficient cooling is not possible. Furthermore, the following Patent Document 2 also describes using the cooling passage as a cooling circuit to circulate a cooling medium. However, circulating the cooling medium alone is not enough to cool the mold.

JP 2021-159930 A JP 2021-154372 A

The objective of the present invention is to improve the cooling efficiency of the mold.

The die-casting die of the present invention is a die-casting die having an inlet and an outlet, and an internal cooling passage through which cooling water flows from the inlet to the outlet, and the cooling passage is provided with an island-shaped weir that protrudes from the wall surface of the cooling passage and controls the flow of the cooling water.

According to this configuration, cooling water is introduced into the cooling passage from the inlet. The cooling water flows through the cooling passage toward the outlet, and is discharged from the outlet to the outside of the cooling passage. The flow of cooling water is controlled by an island-shaped weir installed in the cooling passage. Therefore, stagnation of cooling water in the cooling passage is suppressed.

In particular, it is preferable that the cross-sectional shape of the weir has a directional property that can change the direction of the flow of the cooling water. With this configuration, the direction of the flow of the cooling water is changed by the directional weir. Therefore, the flow of the cooling water can be easily directed toward areas where stagnation is likely to occur.

The cross-sectional shape of the weir is preferably wing-shaped. This configuration allows the flow of cooling water to be smoothly changed.

It is also preferable that the cooling passage has an expansion section whose cross-sectional area is locally expanded by providing a protruding section that protrudes to the side, and that a weir is arranged to send cooling water to the protruding section. With this configuration, the cross-sectional area of the cooling water passage is locally expanded at the expansion section, so that the peripheral portion of the expansion section can be efficiently cooled. Meanwhile, the protruding section of the expansion section is a place where cooling water has difficulty flowing and is prone to stagnation, but the weir directs the cooling water to the protruding section. As a result, cooling water is smoothly supplied to the protruding section, and stagnation of cooling water is less likely to occur at the protruding section.

In addition, it is preferable that the cooling passage has a straight section, and that a plurality of weirs whose cross-sectional shape is line-symmetric are arranged at intervals in the straight section with their symmetry axes facing the width direction of the straight section. When manufacturing the cooling passage, fluid polishing may be performed as a finishing process. By performing fluid polishing, the inner surface of the cooling passage becomes smooth, the occurrence of cracks in the mold can be suppressed, and the life of the mold can be improved. In the fluid polishing process, it is preferable to flow an abrasive from both sides of the cooling passage. Compared to the case where the abrasive is flowed from only one direction of the cooling passage, the inner surface of the cooling passage can be made even smoother and a uniform polishing state can be obtained. When performing bidirectional fluid polishing in this way, it is preferable that the cross-sectional shape of the weir is line-symmetric, and the weir is preferably arranged so that its symmetry axis faces the width direction of the straight section. This makes it possible to make the polishing state uniform when the abrasive is flowed in one direction in the straight section and when the abrasive is flowed in the other direction. Therefore, the inner surface of the straight section of the cooling passage can be polished uniformly by the abrasive. In addition, the surface of the weir can be polished evenly with an abrasive. Furthermore, even if the inlet and outlet of the cooling passage are reversed at the discretion of the casting site, the flow of cooling water in the straight section is constant, and the straight section can be cooled to the desired state.

As described above, a dam is installed in the cooling passage, which prevents the cooling water from stagnating and improves cooling efficiency.

FIG. 2A is a cross-sectional view showing a main portion of a mold according to one embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along the line A-A of FIG. 4A to 4D are cross-sectional views showing the cross-sectional shapes of cooling passages in a mold. FIG. 4 is a diagram showing the flow of cooling water in a cooling passage. 4A is a cross-sectional view showing a main part of a mold in which a dam is provided in a cooling passage, and FIG. 4B is a cross-sectional view taken along the line B-B of FIG. FIG. 4 is a diagram showing the flow of cooling water in a cooling passage. 4A to 4D are diagrams showing the cross-sectional shape of a weir. 6A to 6C are diagrams showing changes in the flow of cooling water caused by a weir. 13A and 13B are diagrams showing changes in the flow of cooling water caused by a weir. 13A and 13B are diagrams showing changes in the flow of cooling water caused by a weir. 5A and 5B are diagrams showing the flow of cooling water at a corner portion of a cooling passage. 4A to 4C are diagrams showing the longitudinal cross-sectional shape of the weir along the protruding direction. 4A to 4C are diagrams showing the longitudinal cross-sectional shape of the weir along the protruding direction. 5A and 5B are cross-sectional views showing a main part of a mold in which a dam is provided in a cooling passage. 14A and 14B are diagrams showing the flow of cooling water in a cooling passage corresponding to FIGS. 13A and 13B, respectively; 5A and 5B are cross-sectional views showing a main part of a mold in which a dam is provided in a cooling passage. 15( a ) and 15 ( b ) are diagrams showing the flow of cooling water in a cooling passage corresponding to FIGS. 15 ( a ) and 15 ( b ), respectively. 5A and 5B are cross-sectional views showing a main part of a mold in which a dam is provided in a cooling passage. 17( a ) and 17 ( b ) are diagrams showing the flow of cooling water in a cooling passage corresponding to FIGS. 17 ( a ) and 17 ( b ), respectively. 1A and 1B are diagrams showing the cross-sectional shape of a weir. 4A and 4B are diagrams showing the flow of cooling water in a straight portion of a cooling passage;

The die-casting die according to one embodiment of the present invention will be described below with reference to Figs. 1 to 18. Fig. 1 shows the main parts of the die. This die is a part of the entire die, specifically, the insert 1. The insert 1 is provided in a movable die, a fixed die, or a core. The insert 1 is attached, for example, to a movable or fixed die, or to a movable or fixed holder in a detachable and replaceable manner. In this embodiment, the insert 1 is attached to the die by fitting its base end portion into the die, or is inserted into the die from the tip side, penetrating the die and protruding from the die. Note that the die does not have to be the insert 1, and may be a die, a core, etc.

In FIG. 1(a), the first direction indicated by the symbol 101 is the mold clamping direction. The direction perpendicular to the first direction 101 is the second direction 102, and the direction perpendicular to the first direction 101 and the second direction 102 is the third direction 103. The embedding element 1 protrudes from the die. The direction in which the embedding element 1 protrudes is the first direction 101. The first end 1a of the embedding element 1 in the first direction 101 is the end away from the die and is the tip end (tip end), and the second end 1b of the embedding element 1 in the first direction 101 is the end close to the die and is the base end. The second end 1b of the embedding element 1 is fitted into the die (not shown). As shown in FIG. 1(b), the embedding element 1 has a thin shape (plate-like) with the third direction 103 as the thickness direction.

The first end 1a of the plug 1 has a notch 2. The notch 2 is cut toward the second end 1b. In this embodiment, two notches 2 are provided. The two notches 2 are arranged at intervals in the second direction 102. The number, arrangement, shape, etc. of the notches 2 are arbitrary, and the notches 2 may not be provided. Since the first end 1a has two notches 2, the first end 1a has a plurality of convex portions that protrude in the first direction 101 relative to the notches 2. In this embodiment, since two notches 2 are provided, three convex portions, the first convex portion 3, the second convex portion 4, and the third convex portion 5, are formed at a distance from each other in the second direction 102. In this way, the first end 1a has unevenness in the first direction 101.

<Cooling Passage 10>
The embedment 1 is formed with a cooling passage 10 for cooling the embedment 1. The cooling passage 10 is provided with a dam 30 as described later, but first, a case where the dam 30 is not provided will be described. The cooling passage 10 is a space provided inside the embedment 1, and is a hollow portion. Cooling water is supplied to the cooling passage 10. The cooling water flows through the cooling passage 10 in one direction. The cooling passage 10 has two openings. The first opening of the cooling passage 10 is an inlet 11, which is a supply port for supplying the cooling water to the cooling passage 10. The second opening of the cooling passage 10 is an outlet 12, which is a discharge port for discharging the cooling water from the cooling passage 10 to the outside. That is, the cooling passage 10 has an inlet 11 at its upstream end and an outlet 12 at its downstream end. In this embodiment, both the inlet 11 and the outlet 12 are provided at the second end 1b of the embedment 1 and open in the first direction 101. The inlet 11 and the outlet 12 are provided at an interval in the second direction 102 at the second end 1b of the plug 1. Either the first opening or the second opening may be the inlet 11. In the following description, the opening on the right side as viewed from the page is referred to as the inlet 11, and the opening on the left side as viewed from the page is referred to as the outlet 12. The inlet 11 and the outlet 12 are provided, for example, at both ends in the second direction 102 at the second end 1b of the plug 1. Cooling water flows through the cooling passage 10 from the inlet 11 to the outlet 12.

The cooling passage 10 has a first section 13 extending in a first direction 101 from the inlet 11 toward the first end 1a, a second section 14 continuing downstream of the first section 13 and extending along the first end 1a, and a third section 15 continuing downstream of the second section 14 and extending from the first end 1a toward the outlet 12 in the first direction 101. The first section 13 and the third section 15 are straight sections (straight sections). In this embodiment, the second section 14 is serpentine because two notches 2 are formed at the first end 1a. The boundary between the first section 13 and the second section 14, and the boundary between the second section 14 and the third section 15 are corners. In this embodiment, the cooling passage 10 is symmetrical in the second direction 102. The first section 13 and the third section 15 are symmetrical to each other.

The cross-sectional shape of the cooling passage 10 is the shape in a cross-sectional view crossing the cooling passage 10. The cross-sectional shape of the cooling passage 10 is non-circular as shown in FIG. 1(b). Specifically, the cross-sectional shape of the cooling passage 10 is a flat shape with the third direction 103 as the minor axis direction and the first direction 101 or the second direction 102 as the major axis direction, and more specifically, is a long hole shape (track shape). In addition to the long hole shape, it may be an ellipse or the like. In this way, by making the cooling passage 10 a long hole shape (flat shape) in cross section, the cross-sectional area of the cooling passage 10 can be expanded in the major axis direction, and the cross-sectional area can be easily expanded compared to the case of a circle, and the amount of cooling water flowing through the cooling passage 10 can be increased.

The dimension of the cooling passage 10 in the long axis direction is defined as the width dimension. The width of the cooling passage 10 may be constant, but in this embodiment, it is locally widened (expanded). The cooling passage 10 expands and contracts the dimension in the long axis direction without changing the dimension in the short axis direction. The cross-sectional shapes of the cooling passage 10 at each point from the first point P1 to the seventh point P7 in FIG. 1 are shown together in FIG. 2. In this embodiment, since the shape is symmetrical in the second direction 102, the first point P1 and the seventh point P7 are identical to each other, the second point P2 and the sixth point P6 are identical to each other, and the third point P3 and the fifth point P5 are identical to each other.

Figures 2(a) to 2(d) show the cross-sectional shapes at the first point P1 to the fourth point P4, respectively. The dimension T in the short axis direction at each point is the same. The widths of each point from the first point P1 to the fourth point P4 are shown as W1 to W4 in Figure 2, respectively. The cross-sectional shape at the first point P1 is the reference shape of the cooling passage 10, and its width W1 is the reference width. The cross-sectional shape at the third point P3 is the same as the cross-sectional shape at the first point P1, and its width W3 is the reference width. The second point P2 is the widest point, and its width W2 is the largest. The reference width is shown by the two-dot chain line in Figures 2(b) and 2(d). The width W4 of the fourth point P4 is slightly wider than the width W1 of the first point P1.

In this way, the width of the cooling passage 10 is not constant over the entire length of the cooling passage 10, but is locally expanded. The cooling passage 10 has a reference section whose width is the reference width and an expanded section whose width is expanded beyond the reference width. Specifically, the cooling passage 10 is divided into four reference sections and three expanded sections. The cooling passage 10 has, in order from the upstream side, a first reference section 20, a first expanded section 21, a second reference section 22, a second expanded section 23, a third reference section 24, a third expanded section 25, and a fourth reference section 26. The first reference section 20 is provided in the first section 13, and the fourth reference section 26 is provided in the third section 15. The first expanded section 21, the second reference section 22, the second expanded section 23, the third reference section 24, and the third expanded section 25 are provided in the second section 14. The first extension 21 corresponds to the first convex portion 3, the second reference portion 22 corresponds to the first notch portion 2, the second extension 23 corresponds to the second convex portion 4, the third reference portion 24 corresponds to the second notch portion 2, and the third extension 25 corresponds to the third convex portion 5.

The expansion portion is a portion where the width of the cooling passage 10 is locally expanded toward the first end 1a. The expansion portion has a protruding portion that protrudes toward the first end 1a. The first expansion portion 21 has a first protruding portion 21a, the second expansion portion 23 has a second protruding portion 23a, and the third expansion portion 25 has a third protruding portion 25a. In FIG. 1(a), the protruding portions are indicated by a number of dots. The first protruding portion 21a, the second protruding portion 23a, and the third protruding portion 25a allow the cooling passage 10 to penetrate into the first convex portion 3, the second protruding portion 4, and the third convex portion 5, respectively.

Cooling water is sent to the cooling passage 10 from a supply device (not shown). Figure 3 shows an analysis image of the flow of cooling water in the cooling passage 10 when the weir 30 is not provided. In the figure, the areas that appear as white streaks are areas where the flow of cooling water is strong. On the other hand, the areas where the white streaks are dotted or black are areas where the flow of cooling water is weak or not flowing. In this way, when the weir 30 is not provided, the cooling water does not flow uniformly across the entire width of the cooling passage 10, but the flow of cooling water becomes uneven. In particular, the flow of cooling water is weak and stagnation occurs in the first protruding portion 21a of the first extension portion 21, the second protruding portion 23a of the second extension portion 23, and the third protruding portion 25a of the third extension portion 25. When stagnation occurs, the cooling effect in that part is reduced, and that part of the embedment 1 is easily damaged by heat. In other words, the first protruding portion 3, the second protruding portion 4, and the third protruding portion 5 are particularly prone to damage. Therefore, it is necessary to improve the flow of cooling water.

On the other hand, Figure 4 shows a case where the dam 30 is arranged in the upstream half region of the cooling passage 10. The dam 30 is island-shaped and many are arranged in the cooling passage 10. The cross-sectional shape of the dam 30 will be described later, but in the form shown in Figure 4, there are two types: aerofoil-shaped and circular. As shown in Figure 4 (b), the dam 30 protrudes from the wall surface of the cooling passage 10. There are various protruding forms, which will also be described later, but in Figure 4, the dam 30 connects two opposing surfaces of the cooling passage 10. In other words, the dam 30 connects wall surfaces of the cooling passage 10 that face each other in the short axis direction.

Figure 5 shows an analysis image of the flow of cooling water when the weir 30 is placed in this manner. The flow of cooling water is uniform on the upstream side of the cooling passage 10. In particular, a flow of cooling water occurs in the first overhanging portion 21a and the second overhanging portion 23a, improving the cooling conditions in the first convex portion 3 and the second convex portion 4. This is because the weir 30 sends cooling water to the first overhanging portion 21a and the second overhanging portion 23a. Note that the weir 30 may also be placed on the downstream side of the cooling passage 10.

<Cross-sectional shape of the weir 30>
Next, the cross-sectional shape of the weir 30 will be described. Figure 6 shows representative examples of the cross-sectional shape of the weir 30. Figure 6(a) shows an airfoil shape, Figure 6(b) shows a circle, Figure 6(c) shows an inverted triangle, and Figure 6(d) shows a kite shape. The kite shape is a quadrangle with two diagonals perpendicular to each other and with two pairs of adjacent sides of equal length. In other words, it has a pair of short sides and a pair of long sides. In Figure 6, it is preferable that the weir 30 is disposed with the left side as viewed from the paper surface being the upstream side. In Figures 6(a), 6(c), and 6(d), a center line 30a along the longitudinal direction of the weir 30 is shown.

Figure 7 conceptually shows the flow of cooling water when the cross-sectional shape of the weir 30 is wing-shaped. When the cross-sectional shape of the weir 30 is wing-shaped, the weir 30 can change the direction of the flow of the cooling water. That is, the cross-sectional shape of the weir 30 has directionality. The wing shape is tapered from one end to the other end in the longitudinal direction. One end of the wing shape in the longitudinal direction is arranged toward the upstream side of the cooling water. As in Figure 7(a), when the longitudinal center line 30a of the wing shape is along the direction of the flow of the cooling water, the weir 30 resists the flow of the cooling water but does not change the flow of the cooling water. On the other hand, as in Figures 7(b) and 7(c), when the longitudinal center line 30a of the wing shape is inclined with respect to the direction of the flow of the cooling water, the cooling water hits the weir 30, and the flow direction of the cooling water changes toward the direction of the longitudinal center line 30a of the wing shape. That is, the direction of the cooling water flow can be changed by placing the wing-shaped weir 30.

Figure 8 conceptually illustrates the flow of cooling water when the cross-sectional shape of the weir 30 is an inverted triangle. Even when the cross-sectional shape of the weir 30 is an inverted triangle, the weir 30 can change the direction of the flow of the cooling water. The inverted triangle is arranged with its base facing the upstream side of the cooling water. The inverted triangle is preferably an inverted isosceles triangle that is long along the flow of the cooling water. As shown in Figure 8 (a), when the base is perpendicular to the flow of the cooling water and the center line 30a of the weir 30 is along the direction of the flow of the cooling water, the weir 30 resists the flow of the cooling water but does not change the flow of the cooling water. On the other hand, as shown in Figure 8 (b), when the base is inclined with respect to the flow of the cooling water and the center line 30a of the weir 30 is inclined with respect to the direction of the flow of the cooling water, the cooling water hits the weir 30, and the flow direction of the cooling water changes toward the center line 30a of the inverted triangle. The center line 30a of the inverted triangular dam 30 is the line that bisects the base.

Figure 9 conceptually illustrates the flow of cooling water when the cross-sectional shape of the weir 30 is kite-shaped. Even when the cross-sectional shape of the weir 30 is kite-shaped, the weir 30 can change the direction of the flow of cooling water. The short side of the kite shape is placed toward the upstream side of the cooling water. The longer diagonal of the kite shape is the center line 30a. As in Figure 9(a), when the center line 30a of the kite shape is aligned with the flow of cooling water, the weir 30 provides resistance to the flow of cooling water but does not change the flow of cooling water. On the other hand, as in Figure 9(b), when the center line 30a of the kite shape is inclined relative to the flow of cooling water, the cooling water hits the weir 30, changing the direction of the flow of cooling water toward the center line 30a of the kite shape.

In this way, when the cross-sectional shape of the weir 30 has directionality, by placing the weir 30 in the cooling passage 10, it is possible to provide resistance to the flow of the cooling water and change the direction of the flow of the cooling water. On the other hand, when the cross-sectional shape of the weir 30 is circular as shown in FIG. 6(b), the circle does not have directionality. Therefore, when a circular weir 30 is placed in the cooling passage 10, it is possible to provide resistance to the flow of the cooling water, but it is not possible to change the direction of the flow of the cooling water. Weirs 30 having directionality such as wing shapes are placed in places where the direction of the flow of the cooling water is changed, and weirs 30 having no directionality such as circles are placed in places where the direction of the flow of the cooling water is not changed. Note that the cross-sectional shape of the weir 30 may be a rhombus as shown in FIG. 19. The rhombus shape also has directionality. The direction of the flow of the cooling water can be changed by making the long diagonal 30b the center line 30a and tilting the long diagonal 30b with respect to the flow direction.

Figure 10 shows a conceptual diagram of the change in the flow of cooling water caused by placing a weir 30 in the cooling passage 10. In the cooling passage 10, for example, when the first straight section 40 on the upstream side and the second straight section 42 on the downstream side are bent at a right angle, the corner section 41, which is the boundary section (bend section) between the first straight section 40 and the second straight section 42, is a place where the cooling water is likely to stagnate. As shown in Figure 10 (a), in the corner section 41, the flow of the cooling water mainly concentrates on the inner side of the corner section 41. Therefore, stagnation is likely to occur on the outer side of the corner section 41. Therefore, as an example, as shown in Figure 10 (b), a large number of wing-shaped weirs 30 are placed from the vicinity of the upstream side of the corner section 41 to the corner section 41. In the first straight section 40, the wing-shaped weirs 30 are placed so that their center lines 30a are along the first straight section 40. This distributes the cooling water and directs the cooling water to the outer side of the corner section 41 as well. In the corner section 41, the center line 30a of the wing-shaped weir 30 is inclined relative to the first straight section 40. This changes the direction of the cooling water flow while also supplying cooling water to the outer side. By arranging multiple weirs 30 in this way from the downstream end of the first straight section 40 to the corner section 41, stagnation on the outer side of the corner section 41 can be eliminated.

<Vertical cross-sectional shape of the weir 30>
The dam 30 protrudes from the wall surface of the cooling passage 10. The protruding direction of the dam 30 may be various, but is preferably the minor axis direction of the cooling passage 10. The cross-sectional shape of the dam 30 cut along the protruding direction is referred to as the longitudinal cross-sectional shape. Figures 11 and 12 show examples of the longitudinal cross-sectional shape of the dam 30. Figure 11 shows a dam 30 connecting a pair of wall surfaces facing each other in the minor axis direction. When the dam 30 connects a pair of wall surfaces facing each other in the minor axis direction, the dam 30 reinforces the cooling passage 10 of the embedment 1, and the strength of the embedment 1 can be easily ensured. In addition, the dimension (width) of the cooling passage 10 in the major axis direction can be expanded while ensuring the strength of the embedment 1.

Figure 11(a) shows a case where the dam 30 protrudes and extends with a constant thickness (constant size) without changing its size along the protruding direction. Figure 11(b) shows a case where the dam 30 becomes thinner (smaller) at a constant rate toward one end in the protruding direction. Figure 11(c) shows a case where the dam 30 becomes suddenly thinner toward one end in the protruding direction. In this way, the longitudinal cross-sectional shape of the dam 30 may be various.

On the other hand, FIG. 12 shows a case where the weir 30 does not connect a pair of wall surfaces opposing each other in the short axis direction. The weir 30 protrudes from one of the pair of wall surfaces opposing each other in the short axis direction toward the other, or from both. FIG. 12(a) and FIG. 12(c) show a case where the weir 30 protruding from one wall surface does not reach the other wall surface. FIG. 12(b) shows a case where the tips of the weirs 30 protruding from each of the pair of wall surfaces face each other and are spaced apart. FIG. 12(d) shows a case where the weirs 30 protrude in a staggered manner so that they are offset from each other from the pair of wall surfaces. In this way, the weir 30 does not have to connect a pair of wall surfaces.

Next, the effects of the weirs 30 on the cooling water will be explained in order for the arrangement of multiple weirs 30 shown in Figure 4. Figure 13(a) shows a case where one weir 30 is arranged immediately upstream of the first overhanging portion 21a of the first expansion portion 21. Figure 14(a) shows an analysis image of the cooling water flow at that time. As is clear from a comparison between Figure 3 and Figure 14(a), it can be seen that by arranging one weir 30, a flow of cooling water is generated toward the first overhanging portion 21a. Next, Figures 13(b) and 14(b) show a case where a second weir 30 is arranged on the first overhanging portion 21a side of the weir 30, and Figures 15(a) and 16(a) show a case where a third weir 30 is arranged. By arranging multiple weirs 30 in a row with a space between them toward the first overhang 21a, the cooling water can be directed to the innermost part of the first overhang 21a. However, in the center of the first overhang 21a, the cooling water stagnates.

Furthermore, Figure 15(b) shows a case where multiple weirs 30 are arranged across the entire width of the first expansion section 21, and Figure 16(b) shows an analysis image of this case. By arranging multiple weirs 30 at intervals in the width direction of the first expansion section 21 in this way, it is possible to distribute the cooling water evenly across the entire width of the first expansion section 21. Note that in Figure 16(b), wing-shaped weirs 30 and circular weirs 30 are arranged. Multiple circular weirs 30 are arranged downstream of the row of wing-shaped weirs 30. Furthermore, the center line 30a of the wing-shaped weirs 30 is inclined.

Furthermore, FIG. 17(a) shows a case where multiple circular weirs 30 are arranged in the second reference section 22, and an analysis image of this case is shown in FIG. 18(a). Furthermore, FIG. 17(b) shows a case where multiple wing-shaped weirs 30 are also arranged in the second expansion section 23, and an analysis image of this case is shown in FIG. 18(b). By arranging multiple weirs 30 from the second reference section 22 to the second expansion section 23 in this way, it is possible to make the cooling water flow evenly in the second protruding section 23a of the second expansion section 23. Although not shown, by arranging multiple weirs 30 downstream from the second expansion section 23, it is possible to make the cooling water flow evenly in the third reference section 24, the third expansion section 25, and the fourth reference section 26.

It is preferable that the cross-sectional shape of the weir 30 is symmetrical between the upstream and downstream sides of the cooling water flow direction. That is, it is preferable that the cross-sectional shape of the weir 30 is line-symmetrical with respect to the cooling water flow direction, and the weir 30 is preferably arranged so that the axis of symmetry is along a direction perpendicular to the cooling water flow direction. There are various types of line-symmetrical shapes, but for example, a diamond shape can be used as shown in FIG. 19. The diamond has a longer diagonal 30b and a shorter diagonal 30c. Of the two diagonals 30b and 30c, it is preferable that the longer diagonal 30b is along the flow direction. That is, the longer diagonal 30b is the center line 30a of the diamond-shaped weir 30. The longer diagonal 30b of the diamond-shaped weir 30 faces the cooling water flow direction, and the shorter diagonal 30c faces a direction perpendicular to the flow direction. The shorter diagonal line 30c is the axis of symmetry, and the diamond shape is linearly symmetrical in the direction of flow.

When manufacturing the cooling passage 10, it is preferable to perform fluid polishing as a finishing process. By performing fluid polishing, the inner surface of the cooling passage 10 becomes smooth, the occurrence of cracks in the mold can be suppressed, and the life of the mold can be improved. In the fluid polishing process, it is preferable to flow an abrasive from both sides of the cooling passage 10, which makes the inner surface of the cooling passage 10 even smoother and achieves a uniform polished state.

When performing bidirectional fluid polishing in this way, it is preferable that the cross-sectional shape of the weir 30 is symmetrical with respect to the flow direction, such as a diamond shape. Figure 19 (a) shows a case where the fluid flows from left to right on the page through the diamond-shaped weir 30, and Figure 19 (b) shows a case where the fluid flows from right to left on the page. If the cross-sectional shape of the weir 30 is symmetrical with respect to the flow direction and its center line 30a is along the flow direction, the effect of the weir 30 on the fluid is the same whether the fluid flows to the right or the left. Therefore, the inner surface of the cooling passage 10 can be polished uniformly with the abrasive, and the surface of the weir 30 can also be polished uniformly with the abrasive. In addition, if the cross-sectional shape of the weir 30 is symmetrical with respect to the flow direction, such as a diamond shape, the inlet 11 and outlet 12 of the cooling passage 10 can be set arbitrarily, for example, at the discretion of the casting site.

Figure 20 shows an example of the arrangement of diamond-shaped weirs 30. When the cooling passage 10 is provided with a straight section 43, it is preferable to arrange a plurality of diamond-shaped weirs 30 on the straight section 43. In detail, the longer diagonal line 30b is arranged along the flow direction. The longer diagonal line 30b of the diamond is along the longitudinal direction X of the straight section 43, and the shorter diagonal line 30c is along the width direction Y (short direction) of the straight section 43. In this way, a large number of diamond-shaped weirs 30 are arranged at intervals, more specifically, in a staggered arrangement. By arranging a large number of diamond-shaped weirs 30 in a staggered arrangement, the cooling water is more likely to flow evenly through the straight section 43. In addition, the flow in both directions is equal, and the inner surface of the straight section 43, including the surface of the diamond-shaped weir 30, can be uniformly fluid-polished. This is not limited to the weir 30 whose cross-sectional shape is diamond-shaped, but also applies to the weir 30 whose cross-sectional shape is line-symmetrical. It is preferable to place the dam 30 on the straight section 43 so that the axis of symmetry of the line-symmetric shape faces the width direction Y of the straight section 43.

1 filler 1a first end 1b second end 2 notch 3 first convex portion 4 second convex portion 5 third convex portion 10 cooling passage 11 inlet 12 outlet 13 first section 14 second section 15 third section 20 first reference portion 21 first extension portion 21a first protruding portion 22 second reference portion 23 second extension portion 23a second protruding portion 24 third reference portion 25 third extension portion 25a third protruding portion 26 fourth reference portion 30 dam 30a center line 30b longer diagonal 30c shorter diagonal (axis of symmetry)
40 First straight portion 41 Corner portion 42 Second straight portion 43 Straight portion 101 First direction 102 Second direction 103 Third direction P1 First point P2 Second point P3 Third point P4 Fourth point P5 Fifth point P6 Sixth point P7 Seventh point

Claims (5)

A die casting mold having an inlet and an outlet, and a cooling passage provided therein through which cooling water flows from the inlet to the outlet,
The cross-sectional shape of the cooling passage is a flat shape having a minor axis direction and a major axis direction perpendicular to the minor axis direction,
a first dam having an island shape is provided in the cooling passage, the first dam connecting wall surfaces of the cooling passage opposed to each other in the minor axis direction , the first dam being spaced apart from wall surfaces of the cooling passage opposed to each other in the major axis direction ;
a cross-sectional shape of the first weir when cut in the major axis direction has directionality capable of changing the flow direction of the cooling water in the major axis direction,
A die casting mold , wherein the center line of the first dam, when viewed in the minor axis direction, is inclined with respect to the direction of the flow of the cooling water so as to change the direction of the flow of the cooling water to the major axis direction . The die casting die of claim 1 , wherein the first dam has a cross-sectional shape that is airfoil-shaped. 3. The die casting mold according to claim 1, wherein the cooling passage has an expansion portion whose cross-sectional area is locally expanded in the longitudinal direction by providing a protruding portion extending in the longitudinal direction , and a first dam is arranged to send cooling water to the protruding portion. 2. The die casting die according to claim 1, wherein the cooling passage has a straight portion, and a plurality of second dams having a cross-sectional shape that is line-symmetrical are arranged in the straight portion at intervals from each other with their axes of symmetry oriented in the longitudinal direction . The die casting die according to claim 1 , wherein the die casting die is plate-shaped with the minor axis direction being the thickness direction.

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