JP2001047190A - Casting method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cast a metallic mold in a short time and to make dense a formed surface in this metallic mold. SOLUTION: This casting device is provided with a mold 12 made of a molding sand 24 and a foaming model 22, metallic mold members 16a-16c disposed as a surface mold on a cavity surface 14 of this foaming model 22, and passages 30a-30d for cooling the inner part. Then, the cooling time of molten metal is shortened and the metallic mold surface is fine-made by making cooling medium flow into the passages 30a-30d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting method and an apparatus for casting a mold using a molten metal of a zinc alloy or an aluminum alloy.

[0002]

2. Description of the Related Art Generally, an operation of injecting a molten metal into a cavity of a mold made of molding sand or the like and cooling and solidifying the molten metal to obtain a desired casting is widely performed.

In this type of casting operation, various attempts have been made to obtain a high quality cast product. For example, Japanese Patent Publication No. Hei 7-224 discloses that a metal gas is poured into a mold, a suction means is activated at the same time, and a cooling gas body passes through a large number of ejection pipes by a supply means. There is disclosed a casting cooling method in which the temperature of the metal hot water is absorbed by the cooling gas body and cooled by being directly injected between the molding sand in the mold from the side.

[0004]

However, in the above-mentioned prior art, since the cooling gas is directly injected into the mold, the cooling gas absorbs the heat of the metal hot water. Cannot be cooled quickly. As a result, the cooling time of the molten metal becomes relatively long, and the quality of the mold as a cast product deteriorates. For this reason, when the cast mold is used, for example, as a mold for resin molding, pinholes are likely to occur on a molding surface (molding processing surface) obtained by processing the surface of the mold, and the resin molding is performed. It has been pointed out that by faithfully reproducing the resin molding surface of the mold on the surface, a problem occurs in that the surface quality of the resin molded product is reduced, and that the strength of the mold itself is also reduced.

The present invention solves this kind of problem, and it is possible to rapidly cool a molten metal to perform a mold manufacturing process in a short time and to maintain a high quality of the mold surface. It is an object to provide a casting method and apparatus.

[0006]

In a casting method and apparatus according to the present invention, a metal mold member having a cooling passage therein is placed as a surface mold on a cavity surface of a mold made of molding sand or the like. A molten zinc alloy or aluminum alloy is poured into the cavity, and a cooling medium is supplied to the cooling passage. For this reason, the molten metal poured into the cavity is directly contacted with the metal mold member and cooled, and is cooled through a cooling medium supplied to a cooling passage provided inside the metal mold member. Is done.

Therefore, the cooling time of the molten metal is shortened at a stroke, and the manufacturing process of the mold is effectively shortened, so that the mold can be obtained efficiently. In addition, since the surface of the mold is rapidly cooled, the surface of the mold and the periphery thereof are densified. This makes it possible to obtain a high-quality molded product without generating pinholes on the molding processing surface of the mold, and to improve the hardness of the mold itself.

Here, the mold is a mold for resin molding, and the entire molding surface of the mold is formed by the surface of the metal mold member. Therefore, pinholes do not occur on the molding surface, and a high-quality resin molded product can be reliably molded.

When the mold taken out of the cavity of the mold is cooled, the mold is held under pressure to prevent the mold from being distorted. For this reason, it is possible to reliably cast a high-quality mold.

Further, the metal mold member is provided with a plurality of cooling passages, and the space between the cooling passages corresponding to the corners or the vertical portions of the metal mold member is set to be smaller than that of the metal mold member. The space is set to be narrower than the space between the cooling passages corresponding to the horizontal flat portion. As a result, it is possible to effectively prevent the occurrence of pinholes at the corners or the vertical walls of the mold to be cast.

Further, the metal mold member is divided into a plurality of parts. Particularly, when casting a large-sized mold, an operation of setting the metal mold member in the mold and an operation of separating the metal mold member from the mold. Is easily accomplished.

[0012]

FIG. 1 is a schematic exploded perspective view of a casting apparatus 10 for carrying out a casting method according to a first embodiment of the present invention.

The casting apparatus 10 includes a mold 12 and the mold 1.
A plurality of metal mold members 16a to 16d arranged as surface molds on the second cavity surface 14. Mold 12
Has a plurality of iron frames 18 stacked in multiple stages, and a plurality of notches 20 are formed in the predetermined iron frame 18. In the iron frame 18, a foam model 22 is formed by molding sand 24.
Buried through.

The foam model 22 is made of styrene foam, and has a cavity surface 14 corresponding to a mold forming surface formed by NC processing. In the first embodiment, the cavity surface 14 corresponds to the shape of a bumper constituting an automobile body. This foam model 2
Reference numeral 2 denotes a cavity for casting a resin molding die to be described later, and the foam model 22 is integrally provided with a sprue-shaped portion 25.

As shown in FIGS. 2 and 3, the metal mold members 16a to 16d are made of an aluminum alloy or a copper alloy, and the surface portions 26a to 26d are arranged on the cavity surface 14 and are cast. Of the entire molding surface. The metal mold members 16a and 16d correspond to the curved portions of the bumper which is a resin molded product, and the metal mold members 16b and 16d
16c corresponds to the horizontal flat portion of the bumper.

On the back side of the metal mold members 16a to 16d,
A plurality of air lines 28a to 28d are fixed to each other, and a cooling passage 30 is provided in the air lines 28a to 28d.
a to 30d are formed (see FIG. 4). Air line 28a
28d are curved on the back side of the metal mold members 16a to 16d, and a supply pipe 31a and a discharge pipe 31b are connected to both ends. The supply pipe 31a is
2 is supported by the mold 12 through a notch 20 of the iron frame 18, and a cooling medium, for example, cold air is supplied to each passage 3.
It can be connected to the cold air supply means 32 for flowing through 0a to 30d. The discharge pipe 31b is open to the atmosphere or can communicate with a suction source (not shown).

As shown in FIG. 3, the metal mold members 16a to 16a-1
In 6d, an interval H1 between the passages 30a and 30d provided corresponding to the corner portion or the vertical portion is set smaller than an interval H2 between the passages 30b and 30c provided corresponding to the horizontal flat portion. Iron plates 34a to 34c are interposed between the metal mold members 16a to 16d, and a plurality of metal plates 16a to 16d are provided at predetermined positions corresponding to the surface portions 26a to 26d and the passages 30a to 30d. Are provided (see FIGS. 1 and 2).

The operation of the casting apparatus 10 thus configured will be described below in relation to the casting method according to the first embodiment.

First, a foaming model 22 having a cavity surface 14 having a predetermined shape is prepared by performing NC processing using styrene foam. This foam model 22
After being placed in the iron frame 18 constituting the mold 12, casting sand 24 is supplied between the foam model 22 and the iron frame 18. Next, the metal mold members 16a to 16d are arranged on the foam model 22 with their respective surface portions 26a to 26d in contact with the cavity surface 14, and an insert plate is provided between the metal mold members 16a to 16d. Certain iron plates 34a to 34c are interposed.

Therefore, as shown in FIG.
Air lines 28a to 28d fixed to 6a to 16d
The supply pipe 31a and the discharge pipe 31b are connected to the supply pipe 31a, and the supply pipe 31a and the discharge pipe 31b are taken out from the cutout portion 20 of the predetermined iron frame 18. Further, FIG.
As shown in FIG. 1, after the foaming model 22 and the metal mold members 16a to 16d are embedded in the mold 12 and the molding sand 24 is filled therein, a nitrogen gas or a carbon dioxide gas is flowed into the molding sand 24 to cause the molding sand 24 to flow. 24 is cured.

Next, as shown in FIG. 7, the mold 12 is inverted and the foam model 22 is removed. This foam model 22
Is easily taken out of the mold 12 by heating by a burner or the like (see FIG. 8). When the sprue-shaped portion 25 is taken out together with the foam model 22, a cavity 40 and a sprue portion 42 communicating with the cavity 40 are formed in the mold 12.

In the cavity 40, the metal mold members 16a to 16a
The 16d surface portions 26a to 26d constitute a mold molding surface, and a release agent is applied to the inner wall surface of the cavity 40 including the surface portions 26a to 26d. After the release agent is dried, a molten metal (molten metal) 44 using a zinc alloy or an aluminum alloy is injected from the gate 42 while the metal mold members 16a to 16d are heated (see FIGS. 9 and 10). . An iron net 45 is arranged in the gate section 42.

In the first embodiment, a Zamak “Zamak” is used to cast a resin molding die. This is a zinc alloy obtained by adding a small amount of Mg to a Zn-Al-Cu system, and has the advantages of being inexpensive, easy to cast, and easier to process than an aluminum alloy. The temperature at which the zinc alloy changes from a solid phase to a liquid phase is 3
In the case of aluminum alloy or copper alloy constituting the metal mold members 16a to 16d, the temperature at which the solid phase changes to the liquid phase is 700 ° C for aluminum and 1064 ° C for copper.
, And each changes to a liquid phase at a higher temperature than the zinc alloy.

By the way, from the gate 42 to the cavity 40
When the molten metal 44 is poured into the passage 30a from the cold air supply means 32 through the supply pipe 31a and the air pipes 28a to 28d.
Cold air is introduced into the air outlets 30 to 30d, and is discharged from the discharge pipe 31b. For this reason, the molten metal 44 in the cavity 40 is rapidly cooled from a portion in contact with the metal mold members 16a to 16d,
The molten metal 44 is hardened to obtain a mold 46. During this time,
The molten metal 44 is repeatedly fed into the cavity 40.

After the molten metal 44 is cooled to obtain the mold 46, the mold 46 is released from the mold 12 as shown in FIG.
16d is removed. At this time, the metal mold members 16a-1
Iron plates 34a to 34c are interposed between 6d, and the work of removing the metal mold members 16a to 16d is easily performed. After the metal mold members 16a to 16d are removed from the mold 46, the iron plates 34a to 34c are removed from the mold 46.

As shown in FIG. 12, the mold 46 is transferred to a press machine 50 and left for a predetermined time while being pressurized through the press machine 50. The press 50 includes a fixed plate 56 whose height can be adjusted with respect to the base 52 via a guide bar 54. A mold 46 is disposed between the base 52 and the fixed plate 56. Is done. A plurality of pushers 58 are arranged between the fixed plate 56 and the mold 46 corresponding to predetermined pressing positions. The pusher 58 has a hydraulic cylinder 60, and a pressing member 64 is fixed to a rod 62 extending from the hydraulic cylinder 60.

Therefore, each pusher 58 is arranged corresponding to a predetermined portion of the mold 46, that is, a portion of the mold 46 where distortion is likely to occur, and when a fluid pressure is applied to the fluid pressure cylinder 60, An end of the fluid pressure cylinder 60 is supported by the fixing plate 56, while a pressing member 64 fixed to the rod 62 applies a pressing force to a predetermined portion of the mold 46. Therefore, while the mold 46 is gradually cooled to, for example, 300 ° C. to room temperature, a predetermined portion of the mold 46
4, and the mold 46 can be reliably prevented from being distorted.

In this case, in the first embodiment, the metal mold members 16a to 16d are arranged as surface molds in the cavity 40, and the passages 30a for circulating cool air inside the metal mold members 16a to 16d. To 30d are provided. When the molten metal 44 is poured into the cavity 40, the cool air is supplied from the cool air supply means 32 to the passages 30 a to 30 d via the supply pipe 31 a and the air pipes 28 a to 28 d. The molten metal 44 is coated on the surface 2 of the metal mold members 16a to 16d.
6a to 26d, that is, the portion corresponding to the entire molding surface 46a of the mold 46 is rapidly cooled.

As a result, the cooling time of the molten metal 44 can be shortened at once, and the mold 46 can be obtained efficiently in a short time, which contributes to cost reduction. Moreover, since the entire surface of the molding surface 46a of the mold 46 is rapidly cooled, the molding surface 46a and the vicinity thereof are densified.
Thus, when the molding surface 46a is processed to obtain a molding surface, no pinholes are generated on the molding surface, and the quality of the resin molded product molded using the mold 46 can be improved at once. The advantage of improvement is obtained. In addition, there is an effect that the hardness in the vicinity of the forming surface of the mold 46 is also improved.

In the first embodiment, a plurality of metal mold members 16a to 16d are provided, and iron plates 34a to 34c are interposed between the metal mold members 16a to 16d. Therefore, metal mold members 16a to 16d for casting a mold 46 for molding a large resin molded product such as a bumper or the like.
Work can be simplified at a stroke. This is because the handling operation becomes easier as compared with the case where a single large and heavy metal mold member is used.

Further, in the metal mold members 16a to 16d,
The interval H1 between the passages 30a and 30d corresponding to the corners or the vertical portion is set smaller than the interval H2 between the passages 30b and 30c corresponding to the horizontal flat portion (see FIG. 3).
For this reason, it is possible to prevent the occurrence of pinholes at the corners (corners) and the vertical walls (vertical portions) of the mold 46 to be cast and formed as much as possible.

Here, the metal mold members 16a to 16d include:
A plurality of temperature sensors 36a to 36d for detecting the temperatures of the surface portions 26a to 26d and the passages 30a to 30d are provided. Thus, by controlling the temperature of the metal mold members 16a to 16d and the passages 30a to 30d, the molten metal 44 can be rapidly cooled easily, and the quality of the molding surface obtained by machining the molding surface 46a of the mold 46 can be improved. Is effectively improved.

FIG. 13 is a schematic structural explanatory view of a casting apparatus 80 according to a second embodiment of the present invention.

This casting device 80 is a pair with the casting device 10 according to the first embodiment, and
0 casts a concave mold 46 while the casting apparatus 80
Is for casting a convex mold (not shown). The casting apparatus 80 includes a mold 86 having a casting sand 82 and a foam model 84, and one or more metal mold members 88 embedded in the mold 86. An air pipe 92 having a cooling passage 90 is fixed inside the metal mold member 88, and the air pipe 92 can communicate with a not-shown cool air supply unit.

The metal mold member 88 is provided with a concave surface portion 94, and this surface portion 94 forms the entire molding surface of the resin molding die. In this metal mold member 88, the air duct 92 extends outward from the side surface of the metal mold member 88, avoiding the surface portion 94.

The operation of the casting apparatus 80 thus configured is the same as that of the above-described casting apparatus 10 according to the first embodiment, and a detailed description thereof will be omitted. This casting device 80
Here, one or more metal mold members 88 are disposed on the cavity surface 14 as a surface mold. Then, the cool air is circulated through the passage 90, so that the convex mold can be efficiently cast in a short time, and no pinholes are generated on the molding processing surface. Similar effects can be obtained.

In the first and second embodiments, a zinc alloy or an aluminum alloy is used for casting the mold 46, but a zinc alloy is preferably used. Zinc alloys are less expensive than aluminum alloys, are easier to cast, and are easier to process. On the other hand, the metal mold members 16a to 16d and 88, which are chills, are preferably made of an aluminum alloy. This is because an aluminum alloy is cheaper and easier to cast than a copper alloy, the surface treatment is easy, and the casting process is shortened.

[0038]

In the casting method and apparatus according to the present invention,
A metal mold member having a cooling passage therein is arranged as a surface mold on the surface of the cavity of the mold, and while pouring the molten metal into the cavity, a cooling medium is supplied to the cooling passage. The mold is rapidly cooled from the molding surface side in contact with the mold member, and the mold can be obtained quickly and efficiently. In addition, the molding surface of the mold is rapidly cooled to achieve densification, and pinholes are prevented as much as possible, so that a mold capable of molding a high-quality molded product can be obtained easily and reliably. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a casting apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory perspective view of a metal mold member constituting the casting apparatus.

FIG. 3 is an explanatory longitudinal sectional view of the metal mold member.

FIG. 4 is a partial vertical cross-sectional explanatory view of the metal mold member.

FIG. 5 is a partial perspective explanatory view of the casting apparatus.

FIG. 6 is an explanatory perspective view showing a state in which the metal mold member is embedded in a mold constituting the casting apparatus.

FIG. 7 is a perspective explanatory view showing a state where the mold is inverted.

FIG. 8 is an explanatory perspective view when the foam model is removed from the mold.

FIG. 9 is an explanatory longitudinal sectional view when a molten metal is poured into a cavity in the mold.

FIG. 10 is a perspective view illustrating a state in which the cavity is filled with a molten metal.

FIG. 11 is an explanatory perspective view of a mold removed from the mold.

FIG. 12 is a schematic perspective explanatory view of a press for pressing a cast mold.

FIG. 13 is a schematic longitudinal sectional view of a casting apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

10, 80: casting apparatus 12, 86: mold 14: cavity surface 16a to 16d,
88: Metal mold member 18: Iron frame 22, 84: Foam model 24, 82: Foundry sand 26a to 26d,
94: surface portions 28a to 28d, 92: air conduits 30a to 30d,
90 ... passage 32 ... cold air supply means 34a-34c ...
Iron plates 36a to 36d Temperature sensors 40 Cavities 42 Gates 44 Melts 46 Molds 46a Molding surfaces 50 Press machines 58 Pushers

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B22D 27/04 B22D 27/04 G (72) Inventor Hiroyuki Tomitsu 1-10-Ninzayama, Sayama-shi, Saitama 1 Honda Engineering Co., Ltd. (72) Nobuho Kikuchi, Inventor 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Masanori Yoshinaga 1-10-1, Shinsayama, Sayama City, Saitama Prefecture Inside Honda Engineering Co., Ltd. (72) Kazuhiro Taguchi 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Inside Honda Engineering Co., Ltd. (72) Inventor Shinji Miyachi 71, Nishinakahama, Yoshida, Oda, Kira-cho, Hazu-gun, Aichi Pref. House (72) inventor Yoshitsugu Kaneko Aichi Prefecture Hazu-gun Kira-cho Oaza Yoshida shaped Nishinaka Hama # 71 areas Kaneko alloy Co., Ltd. in the F-term (reference) 4E093 FA03 FC03 GA08 GB01 GB15 NA02 NB09

Claims (6)

[Claims] 1. A metal member having a cooling passage therein,
A step of disposing as a surface mold on a cavity surface of a mold made of molding sand or the like, and pouring a molten metal of a zinc alloy or an aluminum alloy into the cavity, and supplying a cooling medium to the cooling passage, Cooling the molten metal to produce a mold. 2. The casting method according to claim 1, wherein the mold is a resin molding mold, and the entire surface of the metal molding member is formed by the surface of the metal mold member. Casting method. 3. The casting method according to claim 1, wherein when the mold taken out of the cavity of the mold is cooled, the mold is held under pressure to prevent generation of distortion. Characteristic casting method. 4. A casting apparatus for casting a mold using a molten metal of a zinc alloy or an aluminum alloy, comprising: a mold made of molding sand or the like; and a surface mold on a cavity surface of the mold. A casting apparatus comprising: a metal mold member having a cooling passage therein; and a refrigerant supply unit communicating with the cooling passage and flowing a cooling medium. 5. The casting apparatus according to claim 4, wherein said metal mold member is provided with a plurality of said cooling passages, and each cooling passage corresponding to a corner or a vertical portion of said metal mold member. A casting apparatus, wherein an interval between the cooling passages is set smaller than an interval between the cooling passages corresponding to the horizontal flat portion of the metal mold member. 6. The casting apparatus according to claim 4, wherein said metal mold member is divided into a plurality of parts.