JP2002301558A - Mold structure for casting - Google Patents

Abstract

(57) [Problem] To provide a casting mold structure for preventing intrusion of molten metal into a mold matching portion to prevent occurrence of burrs. SOLUTION: A fixed mold 10 is formed by forming concave portions 11 on both sides of a region A in which a gas vent passage of a chill vent is formed. The movable mold is formed with convex portions 21 and 21 fitted into the concave portions 11 and 11. In a state where both molds are clamped, the convex portions 21 and 21 are inserted into the concave portions 11 and 11.
Are fitted to each other. Even if the molten metal intrudes from the region A along the mold mating surface, the protrusions 21 and 21 function as a burr wall preventing wall for preventing the intrusion of the molten metal and preventing the generation of burrs, thereby preventing the intrusion of the molten metal. To prevent the occurrence of burrs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting mold structure for preventing intrusion of molten metal into a mold matching portion to prevent occurrence of burrs.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. Hei 11-151564 discloses the following regarding chill vents. That is,
In a mold for die-casting light metals such as aluminum alloys, zinc alloys, and magnesium alloys, when the molten metal is pressed into the cavity, the air and gas remaining in the cavity are removed without generating a blowout called flash. A chill vent is used as a device for efficiently discharging the liquid outside the cavity.

FIG. 8 is a diagram showing a general chill vent structure together with a template structure. As shown in this figure, if air or gas remains in the cavity of the mold at the time of die casting, the product gets caught in the molten metal and defects such as gas holes occur in the product, resulting in a decrease in product quality. Therefore, a chill vent 3 provided with a gas vent passage 2 communicating with a cavity 1 for pressure casting of a product is provided to degas the cavity. Reference numeral 4 denotes a die casting mold, and reference numeral 5 denotes a plunger for extruding molten metal.

As shown in the figure, a zigzag meandering shape is used for the above-mentioned gas vent passage 2 in order to rapidly cool and solidify (chill) in the passage after the gas is discharged out of the chill vent and before the molten metal is blown out of the mold (flash). It is generally said that.

[0005] As a material of the chill vent, SKD61 or the like, which is the same type as a die-casting die, has been conventionally used. However, since this type of steel material has a low heat conductivity, solidification debris of aluminum or the like is seized and cannot be released. And the like tend to occur. In order to solve such a problem, a chill vent made of a copper alloy having good thermal conductivity and further provided with a cooling pipe on the outer periphery of the meandering gas vent passage is described in Japanese Patent No. 3025656. I have.

On the other hand, when copper or a copper alloy having good thermal conductivity is used as a material of the chill vent, the elastic deformation of the copper or copper alloy is low, so that plastic deformation is caused by the applied clamping force. Further, the cavity portion to which the mold clamping force is applied following the chill vent has a high elastic modulus and stops within the elastic deformation.
As a result, when the mold clamping force is released after die-casting, only the mating surface of the chill vent sinks slightly below its surroundings, which may cause leakage of hot water and burrs. Was done.

[0007] Therefore, a flat joint portion on both sides of the chill vent to which the mold clamping force is applied is deleted, and the mold clamping force conventionally applied in this region is contracted by the steel material cavities on both sides of the chill vent. In this manner, it is possible to eliminate the above-described leakage of hot water and the occurrence of burrs.
No. -151564.

[0008]

In the case of die casting or high pressure casting, as described above, there is a problem that molten metal penetrates into the mating surface and burrs are easily generated. When burrs occur, the mold mating surface is damaged and deteriorated, and the mold mating surface is liable to be uneven because it receives a mold clamping force. For this reason, it is necessary to perform a mold repairing operation to build up the mating surface or remove the concave portion. In the conventional casting mold,
In particular, burrs are frequently generated around the chill vent and its gate, and a large amount of time is required for mold repair and burr correction, so that the downtime increases (the operating rate decreases).

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is an object of the present invention to provide a casting mold structure capable of preventing intrusion of molten metal into a mold matching portion and preventing occurrence of burrs. Aim.

[0010]

In order to solve the above-mentioned problems, in a casting mold structure according to the present invention, at least a part of a mold joining portion between a fixed mold and a movable mold is formed in one mold. The structure is such that the concave portion and the convex portion formed on the other mold are fitted.

[0011] With a structure in which the concave portion formed in one mold and the convex portion formed in the other mold are fitted into the concave and convex portions, the convex portion acts as a burr prevention wall for preventing the intrusion of molten metal. Therefore, the intrusion of the molten metal into the mold matching portion is prevented, so that no burr is generated. Therefore, non-operation due to mold repair, burr correction and the like is eliminated, and the operation rate is improved.

By forming the concave and convex fitting portions on the outer peripheral portion of the chill vent and the outer peripheral portion of the gate portion, it is possible to prevent burrs from being generated at the chill vent portion and the gate portion. Further, by forming the concave and convex fitting portion on the outer peripheral portion of the cavity portion, it is possible to prevent burrs from being generated in the cavity portion.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a view showing a burr prevention structure (mold structure) according to the present invention. FIG. 1A shows a state before the fixed mold 10 and the movable mold 20 are clamped, and FIG. 1B shows a state where both the molds 10 and 20 are clamped. FIG. 1B shows a state in which the molds 10 and 20 are slightly separated from each other (a state where a gap is formed between the molds) in order to easily distinguish the two molds.

In FIGS. 1 (a) and 1 (b), a region A indicated by a virtual line is a gas vent passage for the chill vent, a gate portion leading to the gas vent passage, and a cavity for forming a product. The fixed mold 10 has a concave portion 11 on the outer peripheral portion of the region A,
11 is provided. The movable mold 20 includes protrusions 21 and 21 fitted to the recesses 11 on the outer peripheral portion of the region A. Then, in a state where the molds 10 and 20 are clamped, the concave portions 11 and 11 and the convex portions 21 and 21 are unevenly fitted.

Even if the molten metal intrudes from the region A along the mold mating surface, the gap formed by the convex portion 21 and the concave portion 11 is not connected straight to the cavity. Prevent occurrence.

Next, a specific chill vent to which the burr prevention structure (mold structure) according to the present invention is applied will be described.
FIG. 2 is a plan view of a chill vent fixing mold, FIG.
FIG. 4 is a side view of the same. FIG. 5 is a plan view of the movable chill vent mold, FIG. 6 is a sectional view thereof, and FIG. 7 is a side view thereof.

In the chill vent fixed mold 30, each convex portion 32, 32 is formed on both sides of a groove group 31 for forming a gas vent passage.
Is provided. Further, concave portions 34, 34 are provided around the gate portion 33 of the gas vent passage. Each convex part 32, 32
Has a height of about 6 mm and a width of about 10 mm. Each recess 3
4, 34 have a depth of about 6 mm and a width of about 10 mm.

In the movable chill vent mold 40, fixed molds 30 are provided on both sides of a group of ridges 41 for forming a gas vent passage.
Concave portions 42, 4 fitted with the convex portions 32, 32 provided on the side.
2 are formed. Further, the gate portion 43 of the gas vent passage is provided.
Are formed around each of the convex portions 44, 44 to be fitted with the concave portions 34, 34 provided on the fixed mold 30 side. Each recess 4
2, 42 have a depth of about 6 mm and a width of about 10 mm. Each of the projections 44 has a height of about 6 mm and a width of about 10 mm.

In a state where the chill vent fixed mold 30 and the chill vent movable mold 40 are clamped, the convex portions 32, 32 and the concave portions 42, 42 are fitted into the peripheral portion of the gas venting passage. Further, in the peripheral portion of the gate portion of the gas vent passage, the concave portions 34, 34 and the convex portions 44, 44 are fitted with the concave and convex. The fitting of these concaves and convexes prevents the molten metal from leaking, thereby preventing burrs from being formed around the gas vent passage and around the gate.

[0020]

As described above, according to the present invention, it is possible to prevent the molten metal from entering the mold matching portion and to prevent the occurrence of burrs. As a result, non-operation due to mold repair or burr correction is eliminated, and the operation rate is improved. Further, by forming the concave and convex fitting portion on the outer peripheral portion of the cavity portion, it is possible to prevent burrs from being generated in the cavity portion.

[Brief description of the drawings]

FIG. 1 is a diagram showing a burr prevention structure (mold structure) according to the present invention.

FIG. 2 is a plan view of a chill vent fixed mold.

FIG. 3 is a sectional view of a chill vent fixed mold.

FIG. 4 is a side view of a chill vent fixed mold.

FIG. 5 is a plan view of a movable chill vent mold.

FIG. 6 is a sectional view of a movable chill vent mold.

FIG. 7 is a side view of a movable chill vent mold.

FIG. 8 is a diagram showing a general chill vent structure together with a template structure.

[Explanation of symbols]

1 ... cavity, 2 ... gas vent passage, 3 ... chill vent,
10, 20: mold, 11: concave, 21: convex, 30: chill vent fixing mold, 31: groove group for forming gas vent passage, 32: convex, 33: gate, 34: concave, 4
0: chill vent movable mold, 41: group of ridges for forming a gas vent passage, 42: concave, 43: gate, 44 ...
Convex part.

Claims (4)

[Claims] 1. A casting mold structure for casting a product by supplying molten metal into a cavity formed by clamping a fixed mold and a movable mold. A casting mold structure, wherein at least a part of the mold matching portion has a structure in which a concave portion formed in one mold and a convex portion formed in the other mold are fitted. 2. The casting mold structure according to claim 1, wherein the portion where the concave portion formed on the one mold and the convex portion formed on the other mold fit together is an outer peripheral portion of the chill vent. A casting mold structure, characterized in that: 3. The casting mold structure according to claim 1, wherein the portion in which the concave portion formed in the one mold and the convex portion formed in the other mold are fitted is an outer peripheral portion of the gate portion. A mold structure for casting. 4. The casting mold structure according to claim 1, wherein the portion in which the concave portion formed in the one mold and the convex portion formed in the other mold are fitted is an outer peripheral portion of the cavity portion. A mold structure for casting.