JP2003062655A - Casting mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casting mold which is capable of restraining the deformation of a partition wall when molten metal material is poured into the cavity of the mold. SOLUTION: The casting mold has a first mold member 12 and a second mold member 24 which are arranged to be capable of relative displacement. The first mold member 12 has a plurality of material inflow holes 19 which are through in the direction of relative displacement and partition walls 22 dividing a plurality of material inflow holes 19, and the second mold member 24 is designed to close the openings 21 of a plurality of material inflow holes 19. The first mold member 12 and the second mold member 24 respectively are provided with engaging concave portions 22A and engaging convex portions 27 which restrain the partition walls 22 from being deformed in the direction of the arrangement of a plurality of material inflow holes 19 owing to mutual engagement.

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a casting for manufacturing a casting by injecting a molten metal material into a cavity and then solidifying and cooling the metal material. It relates to a mold. 2. Description of the Related Art Generally, a heat sink is used as a component of a heat radiating device for dissipating heat of a heating element into the air. This heat sink has a plate-shaped base portion and radiation fins formed at predetermined intervals on the base portion. In recent years, the amount of heat generated by the heating element tends to increase. As a method for improving the heat radiation performance of the heat sink, there is a method of increasing the total heat radiation area of the heat sink by increasing the total number of heat radiation fins. In order to increase the number of fins, the pitch between the radiating fins must be narrowed, and the thickness of the radiating fins themselves must be reduced. When manufacturing a product having a complicated shape like this heat sink, a casting method is used. A mold for manufacturing a heat sink has a plurality of divided mold members, and a cavity corresponding to the shape of the heat sink is formed over the plurality of mold members. Specifically, one mold member has a material inflow portion corresponding to the base portion of the heat sink, and the other mold member has a material inflow portion corresponding to each radiation fin of the heat sink. Then, when one mold member and the other mold member are closed in a mold, when the molten metal material is injected into the cavity, the metal material is injected into each material injection portion, and the metal material is solidified and cooled. ,
A heat sink is manufactured. As described above, it is desired to reduce the thickness of the radiation fin. However, if the gap between the opposing surfaces of the material injection portions corresponding to the radiation fin is set to be narrow according to the thickness of the radiation fin, The gas existing inside the cavity tends to hinder the flow of the metal material. as a result,
The phenomenon that the metal material does not spread to the far end (tip) of the material injection portion, that is, a so-called short shot occurs, and there is a problem that the shape of the heat radiation fin of the manufactured heat sink cannot be made the desired shape. . [0005] In order to cope with such a problem, a casting mold capable of degassing from a material injection portion for forming a radiation fin is used. In this casting mold, a plurality of material injection holes corresponding to each heat radiation fin are provided in a slit shape so as to penetrate the other mold member, and each material injection hole is partitioned by a partition wall. I have. Further, it has a mold member other than the mold member having the material injection hole, that is, a core. The core is made of a porous material, for example, a sintered metal. The core is provided in contact with a mold member having a material injection hole corresponding to the radiation fin. That is, the opening of the material injection hole is closed by the core. As described above, in the casting mold having the core, the molten metal material is injected into the cavity, and when the metal material enters the material injection hole corresponding to the radiation fins, the material in the material injection hole is removed. Since the gas passes through the gap between the core and the mold member, the micropores of the core, and the like, and is discharged to the outside of the cavity, the metal material can be spread over the details of the cavity. However, in the mold using the core as described above, a plurality of material injection holes corresponding to the heat radiation fins penetrate the mold member in a predetermined direction, that is, a so-called mold. It is configured in a slit shape. That is,
The partition formed between the material injection holes is not connected to the mold member at the depth end in the depth direction of the material injection holes. Therefore, the bending load of the partition wall in the arrangement direction of the material injection holes is reduced. For this reason, when the molten metal material enters each material injection hole and the injection pressure of the metal material acts on the partition wall in the direction in which the material injection holes are arranged, the partition wall is aligned with the material injection hole. There was a possibility of deformation in the direction. As a result, the shape of the heat radiation fin cannot be formed into a desired shape, and there has been a problem that the shape accuracy and the dimensional accuracy of the heat sink are reduced. When the deformation of the partition wall occurs at a position corresponding to the tip side of the radiating fins, a phenomenon that the dimension in the arrangement direction of the plurality of radiating fins, that is, the thickness, becomes larger than a target thickness, that is, a so-called under phenomena. A cutting phenomenon may occur. In this way, if the thickness of the radiation fin on the tip side becomes thicker than the thickness of the radiation fin on the base side due to the undercut phenomenon, the heat radiation when removing the manufactured heat sink from the mold There is also a problem that the distal end portion of the fin cannot pass through the portion corresponding to the base end side of the radiation fin in the material injection portion, and the heat sink cannot be released from the mold. The present invention has been made in view of the above-mentioned circumstances, and a casting mold capable of suppressing deformation of a partition wall when a molten metal material is injected into a cavity of the mold. It is intended to provide. In order to achieve the above object, the present invention has a first mold member and a second mold member which are arranged so as to be relatively movable. In one mold member, a plurality of material inflow holes penetrating in the relative movement direction and a partition partitioning between the plurality of material inflow holes are formed, and the second mold member includes: In the casting mold configured to close the openings of the plurality of material inflow holes, the partition wall is formed by mutually engaging at least one of the first mold member and the second mold member. Is provided with an engaging portion for suppressing deformation in the arrangement direction of the plurality of material injection holes. According to the present invention, the apparent strength or rigidity of the partition wall in the direction in which the plurality of material injection holes are arranged is increased by the engagement force of the engagement portion, so that the molten metal material is applied to the material injection hole. Even when the pressure is applied to the partition and the metal material acts on the partition, deformation of the partition in the arrangement direction of the plurality of material injection holes is suppressed. Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a perspective view showing an example of a heat sink 1 manufactured by the casting mold of the present invention. The heat sink 1 is made of a metal material having excellent thermal conductivity, such as aluminum or an aluminum alloy. ing. The heat sink 1 has a plate-shaped base portion 2 and a plurality of radiating fins 3 integrally formed on a single surface 4 of the base portion 2. Each of the heat radiation fins 3 extends in the thickness direction of the base portion 2, and the heat radiation fins 3 are arranged at predetermined intervals. Each radiating fin 3 has a predetermined thickness T, a predetermined length L, and a predetermined height W. Here, the thickness T of the radiating fins 3 is a direction parallel to the surface 4 of the base portion 2 and means a dimension of the radiating fins 3 in the arrangement direction. The length L of the radiation fin 3 is defined as the length of the base portion 2.
In the direction parallel to the surface 4 and perpendicular to the direction in which the heat radiation fins 3 are arranged. Furthermore, the height of the radiation fin 3 means a dimension from the surface 4 of the base 2 to a free end (that is, a tip) of the radiation fin 3. Furthermore, each radiating fin 3 is tapered from its base end toward the free end so that the thickness T becomes thinner. Further, the distance between the center lines A in the thickness direction of the adjacent radiation fins 3 is set to a predetermined pitch P,
A gap G is set between the opposing surfaces of the adjacent radiation fins 3. As described above, the radiation fin 3 is tapered, and the gap G on the free end side of the radiation fin 3 is smaller than the gap G on the base end side of the radiation fin 3. The heat sink 1 having the above-described structure includes a base 2
And the heating element 5 are in a state in which heat can be exchanged, for example,
The base portion 2 and the heating element 5 are arranged in a state of being in close contact with each other.
Examples of the heating element include a drive module for a motor that drives a blower for adjusting a flow rate of an automobile air conditioner. When the heat of the heating element 5 is transmitted to the base 2 of the heat sink 1, the heat is transferred to the base 2.
From the fins 3 to the radiation fins 3
Is conducted on the surface of the fin, that is, the contact surface between the radiating surface and the air, and the heat of the radiating fins 3 is radiated into the air.
Thus, the temperature rise of the heating element 5 is suppressed, or the heating element 5 is cooled. FIGS. 1 and 3 are sectional views showing a casting mold 10 for manufacturing the heat sink 1. The casting mold 10 includes a fixed mold member 11 and a movable mold member 12.
And a core 24. This fixed mold member 11
The movable mold member 12 and the core 24 are aligned with the axis B1.
It is configured to be relatively movable in parallel with. The fixed-side mold member 11 and the movable-side mold member 12 are made of a metal material. The fixed mold member 11 includes the movable mold member 1.
The movable side mold member 12 has a butting surface 13 that contacts the fixed side mold member 11. The butting surfaces 13 and 14 are formed orthogonal to the axis B1. In addition, a material injection portion (in other words, a concave portion) 15 that opens to face the butting surface 13 is formed in the fixed-side mold member 11. The shape and size of the material injection portion 15 correspond to the shape and size of the base portion 2. On the other hand, a concave portion 16 is formed in the movable mold member 12 on the opposite side of the butting surface 14, and the concave portion 16 is continuous with the bottom surface 17 parallel to the butting surface 14. And a side surface 18 parallel to the axis B1
And The movable mold member 12 is provided with a plurality of material injection holes 19 in the axial direction. Each of the material injection holes 19 is formed in a slit shape penetrating the movable side mold member 12 in the axial direction, and one opening 20 of each of the material injection holes 19 is arranged facing the abutting surface 14. The other opening 21 is disposed facing the bottom surface 17. A plurality of the material injection holes 19 are arranged at predetermined intervals in a direction orthogonal to the axis B1 as shown in FIG. Each of the material injection holes 19 is separated from the partition wall 22.
Are divided by Further, the shape and size of each material injection hole 19 correspond to the shape and size of each heat radiation fin 3. Specifically, each material injection hole 19 has an inner peripheral surface 23 facing in the arrangement direction. In the arrangement direction of the material injection holes 19, the gap C between the inner peripheral surfaces 23 is set.
1 is set corresponding to the thickness T of the radiation fin 3. That is, the inner peripheral surfaces 23 are tapered so that the gap C1 becomes narrower from the opening 20 toward the opening 21. Furthermore, the partition wall 22 has a bottom surface 17.
Is formed. The engagement recess 22A has a predetermined depth in the axial direction. The arrangement structure of the engagement recesses 22A may be a structure in which a plurality of engagement recesses 22A are provided at predetermined intervals in the length L1 direction of the material injection hole 19, as shown by a two-dot chain line in FIG. Engagement recess 22 having substantially the same length as length L1 of injection hole 19
Any of the structures provided with a single A can be selected. Further, the core 24 is made of a porous material,
The core 24 is formed of, for example, a sintered metal, and has a size and a shape capable of entering and leaving the recess 16 along the axial direction. The core 24 has an end face 25 that contacts the bottom face 17 of the recess 16,
Side face 2 that is continuous with end face 25 and extends in the axial direction
6. The outer shape of the core 24 is
7 is formed corresponding to the inner surface shape, and an engagement protrusion 27 protruding in the axial direction is formed on the end face 25. Conditions such as the shape, dimensions, number of arrangements, and arrangement positions of the engagement protrusions 27 are set corresponding to the engagement recesses 22A. In this embodiment, the dimension of the engaging recess 22A and the dimension of the engaging projection 27 in a direction orthogonal to the axis B1 are set to be constant in the axial direction. That is, the engagement projection 27 is formed in a columnar or prismatic shape. Next, a process of manufacturing the heat sink 1 by die casting using the casting mold 10 will be described. First, the fixed mold member 11, the movable mold member 12, and the core 24 are relatively moved in the axial direction to close the mold.
In this mold closed state, the butting surface 13 and the butting surface 14 are in contact, the bottom surface 17 and the end surface 25 are in contact, and the side surface 18 and the side surface 26 are in contact. In addition, the engagement protrusion 27 has entered the engagement recess 22A.
In this way, the material injection part 15 and the material injection hole 19 are communicated to form the cavity D1. Next, when the molten metal material E1 is injected at a predetermined pressure into the cavity D1 through a material injection port (not shown), the gas in the cavity D1 flows from the inner end of the material injection hole 19 to After passing through the mating surface of the core 24 and the movable mold member 12 and the fine holes of the core 24, it is discharged out of the casting mold 10. Therefore, the metal material E <b> 1 injected into the cavity D <b> 1 spreads evenly throughout the inside of the cavity D <b> 1, particularly, the inner end side of the material injection hole 19. Then, after the metal material E1 is solidified and cooled, the fixed mold member 11, the movable mold member 12, and the core 24 are relatively moved in the axial direction to open the mold. The molded product is released from the casting mold 10 by protruding a portion located at the injection hole 19 with a protruding pin (not shown), and an unnecessary portion is removed to manufacture the heat sink 1. In the manufacturing process of the heat sink 1 as described above, when the metal material E1 enters the material injection hole 19,
The injection pressure acts on the inner peripheral surface 23, that is, the partition wall 22 substantially orthogonally to the arrangement direction of the material injection holes 19, and attempts to deform the partition wall 22 in the arrangement direction of the material injection holes 19. I do. However, in this embodiment, the engagement recess 22A and the engagement protrusion 27 are engaged, and the side surface 2 of the core 24 and the side surface 18 of the recess 16 are in contact. For this reason, when a load is applied to the partition wall 22 to deform the material injection holes 19 in the arrangement direction, the load is transferred via the core 24 to the movable mold member 12.
And is received by the movable side mold member 12. That is, the apparent strength or rigidity of the partition wall 22 is enhanced by the engagement force between the engagement recess 22A and the engagement protrusion 27. Therefore, even when a load is applied to the partition wall 22 to deform the material injection holes 19 in the arrangement direction, the deformation of the partition wall 22 is suppressed. In this way, the size and shape of the material injection hole 19 are maintained in the state before the injection of the metal material. For the reasons described above, the casting mold 10
Heatsink 1, in particular, radiation fin 3
Processing accuracy of the shape and dimensions of
The product quality of the heat sink 1 is improved. In other words, it is possible to prevent the problem that the thickness of the radiation fin on the tip side is larger than the thickness of the radiation fin on the base end side. For this reason, when taking out the manufactured heat sink 1 from the casting mold 10, it is possible to prevent the problem that “the tip side of the radiating fin cannot be taken out of the material injection portion” beforehand, and to release the product. The performance is improved. Further, in order to improve the accuracy of the shape and dimensions of the heat radiation fins 3, the thickness T of the heat radiation fins 3 of the heat sink 1 as a product is set as thin as possible, and the heat radiation within a predetermined area of the base 2 is performed. By increasing the total number of the fins 3 and enlarging the total heat radiation area of the radiating fins 3, the heat transfer coefficient can be improved and the heat sink 1 can be prevented from being enlarged. Here, the configuration shown in FIGS. 1, 3, and 4
Explaining the correspondence with the configuration of the present invention, the fixed mold member 11 corresponds to the first mold member of the present invention, the movable mold member 12 corresponds to the second mold member of the present invention, Joint recess 2
2A and the engagement protrusion 27 correspond to the engagement portion of the present invention,
The opening 21 corresponds to the opening of the present invention, and the bottom surface 17 corresponds to the end of the partition of the present invention. FIG. 5 shows the movable mold member 12 and the core 24.
It is sectional drawing which shows the other example of a structure. In FIG. 5, the direction in which the engagement concave portion 30 of the movable-side mold member 12 and the engagement protrusion 31 formed on the core 24 approach the fixed-side mold member 11 and are orthogonal to the axis B <b> 1. Is provided with a tapered shape that reduces the size of the tapered shape. That is, the engaging recess 30 and the engaging protrusion 31 are formed in a truncated cone shape. The other configuration in FIG. 5 is the same as the configuration in FIG. 1, FIG. 3, and FIG. In the embodiment shown in FIG. 5, when the casting mold is closed, the engagement projection 31 enters the engagement recess 30. Therefore, the load acting on the partition wall 22 due to the injection of the metal material is transmitted to the core 24 via the engagement protrusion 31 and received by the movable mold member 12. Therefore, also in the embodiment of FIG. 5, for the same reason as in the embodiments of FIGS. 1, 3, and 4, the same effects as those of the embodiments of FIGS. 1, 3, and 4 can be obtained. In the embodiment of FIG. 5,
Since the engagement concave portion 30 and the engagement protrusion 31 have a tapered shape in which the dimension in the direction orthogonal to the axis B <b> 1 becomes narrower as approaching the fixed-side mold member 11, the movable mold member 12 and the When the child 24 is separated, there is another advantage that the inner surface of the engagement recess 30 and the outer surface of the engagement protrusion 31 do not slide, and the separation is excellent. here,
Explaining the correspondence between the configuration of the embodiment of FIG. 5 and the configuration of the present invention, the engaging concave portion 30 and the engaging projection 31 correspond to the engaging portion of the present invention. FIG. 6 shows the movable mold member 12 and the core 24.
It is sectional drawing which shows the other example of a structure. In FIG. 6, a plurality of engaging projections 34 that enter the adjacent material injection holes 19 are formed on the end face 25 of the core 24. In the axial direction, the length of the engagement projection 34 is set shorter than the length of the material injection hole 19. In the core 24, a concave portion 35 is formed between adjacent engaging protrusions 34. Other configurations in FIG. 6 are the same as those in FIGS. 1, 3, and 4. In the embodiment of FIG. 6, the core 24 and the first
When the mold member 12 is fitted, the engaging protrusion 34 enters each material injection hole 19 and a part of the partition wall 22 enters the concave portion 35. That is, the partition 22 is sandwiched by the two engagement protrusions 34. For this reason,
Due to the injection of the metal material, the load acting on the partition wall 22 is transmitted to the core 24 via the engaging projection 34 and received by the movable mold member 12. Therefore, also in the embodiment of FIG. 6, for the same reason as in the embodiment of FIGS. 1, 3, and 4, the same effect as in the embodiment of FIGS. 1, 3, and 4 can be obtained. Here, the correspondence between the configuration of the embodiment of FIG. 6 and the configuration of the present invention will be described. The engaging projection 34, the material injection hole 19, and the concave portion 35 correspond to the engaging portion of the present invention. As described above, in each embodiment, in the direction orthogonal to the axis B1, the engaging portion that generates the engaging force, in other words, the concave portion and the convex portion are provided on at least one of the movable mold member 12 and the core 24. It should just be. As described above, according to the present invention,
The apparent strength or rigidity of the partition wall in the arrangement direction of the plurality of material injection holes is increased by the engagement force of the engagement portion. Therefore, when the molten metal material is injected into the material injection hole, the deformation of the partition wall due to the injection load is suppressed. Therefore, the accuracy of the shape and dimensions of the heat sink manufactured by the casting mold, particularly the shape and size of the heat radiation fins, can be improved, and the product quality of the heat sink can be improved. In other words, "The thickness of the tip of the radiation fin is
It becomes thicker than the thickness of the heat radiation fin on the base end side. " Thus, when taking out the manufactured heat sink from the casting mold,
It is possible to prevent the problem that the tip side of the heat radiation fin cannot be taken out of the material injection section,
Product releasability is improved. In order to improve the accuracy of the shape and size of the radiation fins, the thickness of the radiation fins of the heat sink as a product is set as thin as possible, and the total number of the radiation fins within a predetermined area of the base portion is set. Can be increased. Therefore, the heat dissipation area of the heat sink as a whole is enlarged, the heat transfer coefficient can be improved, and the increase in the size of the heat sink can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an example of a casting mold of the present invention. FIG. 2 is a perspective view showing a heat sink manufactured by the casting mold of the present invention. FIG. 3 is a sectional view showing an example of a casting mold according to the present invention. FIG. 4 is a side view of a movable mold member of the casting mold shown in FIG. FIG. 5 is a partial sectional view showing another example of the casting mold of the present invention. FIG. 6 is a partial sectional view showing another example of the casting mold of the present invention. [Description of Signs] 10: Casting mold, 12: Movable mold member, 17: Bottom surface, 19: Material inflow hole, 21: Opening, 22: Partition wall, 24: Core, 22A, 30: Engagement concave portion , 2
7, 31, 34: engagement projection, 35: recess.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Rokuro Shimada             1723-2 Koganei, Nitta-cho, Nitta-gun, Gunma (72) Inventor Yasuo Takemura             Fuji Co., Ltd., 1440, Rokuzaki, Sakura City, Chiba Prefecture             Kura Sakura Office (72) Inventor Kazuya Akashi             Fuji Co., Ltd., 1440, Rokuzaki, Sakura City, Chiba Prefecture             Kura Sakura Office (72) Inventor Takehisa Ide             Fuji Co., Ltd., 1440, Rokuzaki, Sakura City, Chiba Prefecture             Kura Sakura Office (72) Inventor ▲ Saki ▼ Koji Yama             Fuji Co., Ltd., 1440, Rokuzaki, Sakura City, Chiba Prefecture             Kura Sakura Office (72) Inventor Hiroshi Ogino             45-1, Mizuki, Nitta-cho, Nitta-gun, Gunma

Claims (1)

Claims 1. A first mold member and a second mold member which are arranged so as to be relatively movable, and wherein the first mold member has a plurality of members penetrating in the relative movement direction. Are formed, and a partition partitioning between the plurality of material inflow holes is formed, and the second mold member is configured to close openings of the plurality of material inflow holes. In the casting mold, the partition wall is deformed in an arrangement direction of the plurality of material injection holes by mutually engaging at least one of the first mold member and the second mold member. A casting mold, wherein an engagement portion for suppressing is provided.