JP2015196165A - Molding die and molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding die in which a gas venting passage cross-sectional area is enlarged so that injection time is reduced, and a molding apparatus.SOLUTION: A molding die comprises an air vent which is directly opened to a cavity and allows a tip of molten metal to be solidified. The air vent includes: an inlet air vent extending from the cavity; an enlarged air vent to which a discharge side of the inlet air vent is connected and which has been widened to have an area larger than the inlet air vent; and a discharge air vent extending from the enlarged air vent to be released to atmospheric air outside the die. A thickness of the inlet air vent and the enlarged air vent are substantially the same, and the discharge air vent has multiple connection openings to the enlarged air vent.

Description

  The present invention relates to a molding die and a molding apparatus, and more particularly to a molding die and a molding apparatus suitable for application to a die casting apparatus.

  The die casting apparatus is configured to inject a molten metal into a cavity formed inside after molding a fixed mold and a movable mold, and form a product that follows the shape of the cavity. The molten metal extruded from the injection device is filled into the cavity from the gate, but since the gas (air) is filled inside the cavity, a degassing passage is opened in the cavity in advance, and the molten metal is filled into the cavity. Thus, the internal gas is extruded into the gas vent passage, and is released from the gas vent passage to the atmosphere. Usually, the molten metal is supplied in a larger volume than the cavity volume because it contains a filling amount in the hot water reservoir called overflow that becomes a escape part of the residue such as oxide provided in the middle of the gas vent passage, Gas is expelled from the cavity.

  FIG. 4 is a schematic sectional view of a conventional die casting apparatus. The die casting apparatus 1 has a mold 2 composed of a fixed mold 2a and a movable mold 2b. A cavity 3 serving as a mold is formed on the mating surface of the fixed mold 2a and the movable mold 2b. A gate 6 for introducing the molten metal 5 extruded from the molten metal injection device 4 into the cavity 3 is connected to the cavity 3. The exhaust side passage 8 is formed with an opening on the downstream side in the hot water flow direction in the cavity 3. The exhaust side passage 8 serves as an outlet of the molten metal 5 filled in the cavity 3 along with the injection, and performs gas venting.

  By the way, as shown in FIGS. 5 to 6, the exhaust-side passage 8 is provided with an overflow (hot water reservoir) 8 a as a escape portion for residues such as oxides of the molten metal 5 filled in the cavity 3. ing. The overflow 8a and the cavity 3 are connected by an overflow gate 8b, and an air vent (gas vent) 8c communicating with the atmosphere is connected to the overflow 8a. The air vent 8c has a narrow gap (around 0.1 mm), and the molten metal 5 enters the air vent but is immediately cooled and solidified. Therefore, the molten metal 5 is supplied until it reaches the overflow 8a after filling the cavity 3, and the internal gas pushed out by the molten metal 5 is exhausted to the atmosphere through the air vent 8c. The molten metal 5 seals the cavity 3 by solidifying so-called molten metal at the portion of the air vent 8c where the gap thickness is narrow (around 0.1 mm). As a result, the inside of the cavity 3 can be boosted.

JP 2006-289461 A

  However, in the conventional die casting apparatus, when a hot water reservoir (overflow) exists, after the primary filling into the cavity 3, a so-called secondary filling phenomenon occurs in which the molten metal is subsequently filled into the hot water reservoir (overflow). Due to this delay, there is a problem that causes the quality of the product to deteriorate, and there is a disadvantage that the yield is lowered and the environment of the manufacturing site is deteriorated. Also, when the thickness of the overflow gate 8b connected to the hot water reservoir (overflow) is smaller than the standard thickness of the minimum part of the product, for example, secondary filling is performed in the overflow gate 8b and the hot water reservoir (overflow). It was causing a phenomenon.

  Moreover, since the air vent (gas vent) is provided at the tip of the overflow, the number is limited, and it is difficult to increase the gas vent cross-sectional area. This makes it difficult to fill the molten metal for a short time.

  In addition, as a countermeasure against defects involving gas, there are cases where forced exhaust is performed with a vacuum device, which not only increases the cost of equipment and molds and causes malfunctions, but also causes secondary filling as well as overflow, There was a problem that caused quality degradation.

  In addition, a short-time filling method has been proposed in which molten gas is cast into a mold in about half the time of the conventional method to finely diffuse the entrained gas. There were a problem that the fine diffusion phenomenon could not be caused and a problem that it was necessary to deal with degassing in a shorter time than before.

  The present invention has been made paying attention to the above-mentioned conventional problems, and eliminates the overflow and can suppress the occurrence of the secondary filling phenomenon that causes the delay of the pressurization time as much as possible. An object is to provide an apparatus. It is another object of the present invention to provide a molding die and a die casting apparatus that can ensure a large exhaust cross-sectional area and prevent gas from being caught in a molded product. Further, a molding metal that can take a large degassing cross-sectional area, and can thereby be used to fill a molten metal in a short time, thereby producing a molded product in which the entrained gas resulting from the short-time filling is finely diffused. An object is to provide a mold and a die casting apparatus.

  In order to achieve the above object, the molding die according to the present invention is provided with an air vent that directly opens into the cavity and allows the molten metal to solidify, and the air vent extends from the cavity, and The outlet side of the inlet air vent is connected, and has a widened enlarged air vent having a larger area than the inlet air vent, and an outlet air vent extending from the enlarged air vent and opened to the atmosphere outside the mold, The inlet air vent and the enlarged air vent have substantially the same thickness, and a plurality of outlet air vents are connected to the enlarged air vent.

  A plurality of the inlet air vents are provided, and the passages are relatively narrow with respect to the enlarged air vent and the length thereof is shortened.

  Further, the molding apparatus according to the present invention is provided with an air vent that directly opens into the cavity and enables the solidification of the molten metal, and the air vent is connected to an inlet air vent extending from the cavity and an outlet side of the inlet air vent. A widened expanded air vent having a larger area than the inlet air vent and an outlet air vent extending from the expanded air vent and opened to the atmosphere outside the mold, the inlet air vent and the expanded air The vents have substantially the same thickness, and the outlet air vent includes a mold having a plurality of openings connected to the enlarged air vent. Also in this case, a plurality of the inlet air vents are provided, and the passages can be configured to have a relatively narrow width and a short length relative to the enlarged air vent.

  According to the above configuration, since the overflow is eliminated and the structure in which the air vent is directly opened in the cavity is adopted, the molten metal filled in the cavity can shut the molten metal by solidification of the tip at the air vent portion. The so-called secondary filling phenomenon can be eliminated, and the effect of improving the quality as well as shortening the filling time is brought about. In other words, the thicknesses of the inlet air vent and the enlarged air vent are substantially the same, so that the flow of molten metal to the inlet air vent and the enlarged air vent can flow smoothly like the product (cavity) part. Become. As a result, it is possible to prevent secondary filling.

  In addition, by providing an enlarged air vent with a larger area than the inlet air vent, it is possible to connect multiple outlet air vents. As a result, the degassing characteristics can be remarkably improved.

  Compared to the conventional case where the opening area of the inlet air vent is not large and the number of installations is limited to facilitate post-processing such as removal of non-product parts outside the cavity, multiple inlet air vents are used. Since it is provided, the degassing cross-sectional area can be increased while facilitating post-processing.

  Furthermore, since the inlet length of the inlet air vent can be shortened, it is possible to prevent the gas passage due to filling with the release material from being constricted, and to suppress the occurrence of deformation deformation constriction due to thermal expansion. The effect that can be done is captured.

It is a principal part schematic sectional drawing of the die-casting apparatus which has a shaping die concerning this embodiment. It is a principal part front view of the shaping die of this embodiment. It is the III-III sectional view taken on the line of FIG. It is a principal part front view of the shaping die of a prior art example. It is a principal part front view of the shaping die of a prior art example. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .

  FIG. 1 is a sectional view showing a schematic configuration of a die casting apparatus according to the present embodiment. The die casting apparatus basically includes a mold having a cavity, a gate-side passage that is disposed in the mold and serves as an inlet for injecting molten metal into the cavity, and an exhaust that is disposed in the mold and degass the cavity. It has a side passage. That is, as shown in FIG. 1, the die casting apparatus 10 has a mold 12 including a fixed mold 12 a and a movable mold 12 b. A cavity 14 serving as a mold is formed on the mating surface of the fixed mold 12a and the movable mold 12b. A gate 16 for introducing the molten metal 22 extruded from the molten metal injection device 20 into the cavity 14 is connected to the cavity 14. The exhaust side passage 18 is formed with an opening on the downstream side in the hot water flow direction in the cavity 14. This exhaust side passage 18 becomes an outlet of the molten metal 22 filled in the cavity 14 along with the injection, and performs gas venting.

  The molten metal injection device 20 is connected to the runner of the mold 12 and includes a hollow sleeve 24 and a plunger 26 disposed in the sleeve 24. The molten metal 22 is supplied into the sleeve 24 from a molten metal supply device (not shown), and the molten metal 22 is injected into the cavity 14 through the gate 16 by pushing out the plunger 26. The plunger 26 is operated by an injection driving means (not shown).

  In this basic configuration, the present embodiment employs a structure in which an overflow provided in the exhaust side passage 18 is eliminated and an air vent is directly opened in the cavity 14. That is, the exhaust side passage 18 is constituted by the air vent itself. A specific structure is shown in FIGS.

  FIG. 2 shows a mold matching surface of the exhaust side passage 18 portion of the fixed mold 12a. As shown in this figure, a cavity 14 for forming a product is provided, and an air vent that opens directly into the cavity 14 and enables the molten metal to be solidified is provided. This air vent is provided with an inlet air vent 30 extending from the cavity 14 and an enlarged air vent 32 which is connected to the outlet side of the inlet air vent 30 and has a larger area than the inlet air vent. Further, an outlet air vent 33 extending from the enlarged air vent 32 and opened to the atmosphere outside the mold 12 is provided, and a plurality of the outlet air vents 33 are opened to connect to the enlarged air vent 32. . By providing a plurality of the outlet air vents 33, the gas once stored in the enlarged air vent 32 can rapidly flow to the outside air.

A plurality of the inlet air vents 30 are provided, and the passages are relatively narrow with respect to the enlarged air vent 32.
As shown in FIG. 3, the cross-sectional shape of the air vent (exhaust side passage 18) in the thickness direction is such that the inlet air vent 30 and the enlarged air vent 32 from the opening to the cavity 14 have substantially the same thickness. The thickness is set to be larger (1.5 to 2.5 mm) than the standard thickness of the minimum part of the product, for example. Thereby, the flow of the molten metal to the inlet air vent 30 and the enlarged air vent 32 can be made to flow smoothly in the cavity 14, that is, like the product portion. As a result, it is possible to prevent secondary filling. The thickness of the passage from the outlet air vent 33 to the outer end surface of the mold 12 is 0.08 to 0.1 mm, and the air is released to the atmosphere with a gradient from the middle to the outer end of the mold 12. ing. Of course, it is also possible to form a uniform gradient from the opening of the cavity 14 to the outer end of the mold 12. By doing in this way, the molten metal filled in the cavity 14 is cooled by the mold 12 as the internal gas is exhausted from the air vent to the atmosphere, and the molten metal tip of the pushed molten metal 22 enters the air vent. The inside of the cavity 14 can be boosted by solidifying and sealing the passage.

  By the way, the exhaust passage cross-sectional area of the inlet air vent 30 cannot be increased in order to facilitate post-processing such as removal of a non-product portion outside the cavity 14. Therefore, in this embodiment, since a plurality of inlet air vents 30 are provided with a narrow width, it is possible to increase the degassing cross-sectional area while facilitating post-processing.

  In the molding die and the molding apparatus configured as described above, when the molten metal 22 is injected from the molten metal injection device 20 into the cavity 14, the internal gas passes through the inlet air vent 30 as the molten metal 22 fills the cavity 14. Exhausted. An enlarged air vent 32 is provided at the tip of the inlet air vent 30, and the gases exhausted from the plurality of inlet air vents 30 are once collected and exhausted from the inclined outlet air vent 33 to the atmosphere. Since the passage length of the inlet air vent 30 from the cavity 14 to the enlarged air vent 32 is short, the exhaust resistance during this period can be greatly reduced. As a result, it is possible to increase the exhaust capacity without adding a vacuum suction facility, and thus it is possible to construct a die casting apparatus with low cost and high production efficiency. In addition, since the length of the inlet air vent 30 reaching the enlarged air vent 32 is short, even if a release material enters, the inlet air vent 30 is not clogged here, and the transition is made to the widened enlarged air vent 32, so that the exhaust passage is clogged. There is also a merit that there is no.

  In addition, a plurality of outlet air vents 33 are opened for connection, so that the gas once accumulated can easily escape to the outside air. This also increases the gas exhaust capacity.

  After the molten metal 22 fills the cavity 14, all the internal gas is exhausted through the inlet air vent 30 and the enlarged air vent 32, enters the outlet air vent 33, and the tip solidifies and seals. As a result, secondary pressurization of the cavity 14 becomes possible, and a dense die-cast product is manufactured.

According to such an embodiment, an overflow is unnecessary, there is no reservoir outside the cavity, no secondary filling phenomenon occurs, and a large exhaust cross-sectional area of gas can be taken, so that the internal quality of the product Can be improved. Moreover, the fine diffusion phenomenon of the entrapment nest can be realized in the short time filling method, so that the defect rate of the die-cast product can be reduced, and the number of discarded shots can be reduced.
Since an overflow and a vacuum runner are unnecessary, the product yield is improved, and it is not necessary to adopt a vacuum die casting method, so that the production cost can be reduced.

DESCRIPTION OF SYMBOLS 10 ......... Die-casting device, 12 ......... Mold, 12a ......... Fixed type, 12b ......... Movable type, 14 ......... Cavity, 16 ...... Gate, 18 ...... Exhaust side passage, 20 ... ... Molten metal injection device, 22 ... Melt, 24 ... Sleeve, 26 ... Plunger, 30 ... Inlet air vent, 32 ... Expanded air vent, 33 ... Outlet air vent

Claims (3)

  An air vent is provided that opens directly into the cavity and enables the molten metal to solidify. The air vent is connected to an inlet air vent extending from the cavity and the outlet side of the inlet air vent, and has a larger area than the inlet air vent. A widened expanded air vent and an outlet air vent extending from the expanded air vent and opened to the atmosphere outside the mold, and the inlet air vent and the expanded air vent have substantially the same thickness. A plurality of outlet air vents are connected to the enlarged air vent, and the molding die is characterized in that a plurality of outlet air vents are opened.   2. The molding die according to claim 1, wherein a plurality of the inlet air vents are provided, and the passage is relatively narrow with respect to the enlarged air vent and is shortened. Characteristic mold.   A molding apparatus comprising the molding die according to claim 1.

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