JP4637609B2 - Chill vent nesting - Google Patents

Description

  The present invention relates to a chill vent used for smooth degassing from a cavity in metal casting, resin injection molding, and the like. In particular, a mold release means for extruding a solidified material in the chill vent ( The present invention relates to a chill vent insert provided with an ejector) in a state independent of a mold body.

  For example, in die casting of an aluminum alloy, when filling a mold with a molten metal, air is trapped in the casting from the sleeve to the mold cavity, or gas is generated due to the mold release agent. (Blowhole) may occur, and such a defect adversely affects the internal quality of the casting, leading to a decrease in confidentiality and strength. For this reason, it is common to provide an air vent in the mold to ensure gas escape properties, but the groove depth of the air vent to the extent that the molten metal does not blow out of the mold is about 0.05 mm.

However, it is difficult to maintain the necessary and sufficient gas escape characteristics with an air vent of this size, so a chill vent with a vent shape that has a large venting cross-sectional area but prevents the molten metal from blowing out of the mold. It is practiced to arrange a part called “inside” in a mold (see, for example, Patent Document 1).
The chill vent has a gas vent passage generally having a corrugated vent shape in order to solidify the molten metal reliably in the chill vent, and exhibits a higher gas venting effect by being arranged in the final filling portion of the molten metal. Therefore, a high-quality casting can be obtained by using such a chill vent.
Japanese Patent Laid-Open No. 10-249508

  In the mold provided with the chill vent as described above, when the mold is opened after casting, in order to surely release the aluminum alloy material solidified in the corrugated gas vent passage of the chill vent, the chill vent portion is also separated. Although it is necessary to provide an ejector pin as a mold means, conventionally, as shown in FIG. 6, the ejector pin 21 provided on the chill vent 20 is a product P arranged on the main body portion of the mold 30. It is connected to an ejector plate 31 of a release mechanism for extruding, and is operated simultaneously with an ejector pin 32 for extruding a product in conjunction with the release mechanism for the product.

However, if the ejector pins 21 for the chill vent are arranged as described above, the ejector plate 31 of the mold body portion must be designed to be large so that the degree of freedom in designing the mold is reduced, and the casting plan and other layouts. It may interfere with the mold and may affect the mold strength.
Also, in order to improve the casting method for molds that have already been completed, chill vents are often newly installed, added, or moved. In such cases, ejector pins are used. There is a problem that a great deal of labor and cost are required, such as movement, addition, and change of specifications of the ejector plate 31.

  The present invention has been made in view of the above-mentioned problems in a conventional mold having a chill vent and a mold release means for a material solidified in the chill vent. It is an object of the present invention to provide a chill vent insert that can be released from the mold, has a high degree of design freedom in chill vent arrangement, and can easily cope with design changes such as movement and addition of chill vents.

  As a result of intensive studies aimed at the above-mentioned purpose, the present inventors can achieve the above-mentioned object by providing a nesting structure in which the chill vent is separated from the mold body and uniquely arranging release means such as an ejector pin. As a result, the present invention has been completed.

The present invention is based on the above knowledge, and the chill vent insert of the present invention is a chill vent insert that has a gas vent passage communicating with the mold cavity and is used by being attached to the mold. The mold release means for extruding the material solidified in the path is provided on both the fixed side and the movable side in a state independent of the product release mechanism solidified in the cavity of the mold.

According to the present invention, the chill vent insert separated from the mold main body is provided with a mold release means for discharging the material solidified in the chill vent in a state independent of the mold release mechanism for the mold main body portion. Independent from the mold body in terms of structure, function and operation, the chill vent can be placed regardless of the position of the mold release mechanism of the mold body, and the freedom of mold design In addition, the excellent effect of being able to easily cope with the movement and addition of the chill vent is brought about. In addition, since the mold release means is provided in both the fixed side and movable side blocks, the mold released from the chill vent block can be reliably removed from the solidified material in the gas vent passage.

  Hereinafter, the chill vent insert of the present invention will be described in more detail together with the embodiment thereof.

As described above, the chill vent insert of the present invention has a separate structure from the mold body, and has a built-in release means dedicated to the chill vent, improving the degree of freedom in mold design, This makes it easy to deal with new chill vents, expansions, and movements of existing dies, but as dies for mounting the chill vent inserts of the present invention, various metal casting dies such as cast iron It can be applied to molds for gravity casting, low / medium pressure casting, die casting, squeeze casting, etc. for copper alloy, zinc alloy, aluminum alloy, magnesium alloy, titanium alloy and the like.
Moreover, it can be applied not only to the casting mold as described above, but also to an injection molding mold of a resin material. It is possible to prevent defects such as blow holes caused by gas.

In the chill vent nesting of the present invention, the release means comprising a knockout pin or the like can provide a temporary effect by being provided on either the movable block or the fixed block constituting the chill vent nesting, for example, on the movable block side. it can. However , the chill vent degassing path has a complicated surface shape such as a corrugated shape, so that the releasability of the solidified material is not necessarily good, and solidifies in the degassing path. In order to reliably release the mold from the chill vent block, it is necessary to provide mold release means on both the chill vent block, that is, both the fixed block and the movable block.

In addition, as a material used for the chill vent insert of the present invention, it is desirable to use an alloy tool steel such as SKD61, for example, when importance is attached to the erosion resistance, and by applying a surface treatment such as nitriding to the surface, It is also possible to use after increasing the hardness.
It is also preferable to use a copper-based alloy from the viewpoint of thermal conductivity.

  Further, as a power source for operating the mold release means, it is common to use a spring because it is the simplest structurally and advantageous in terms of cost, but it is limited to only a spring. Instead, for example, an air cylinder, a hydraulic cylinder, an electric motor, or the like can be used, and it is also possible to control the operation start timing of the release means so as to synchronize with the mold opening of the mold.

The chill vent insert of the present invention is preferably provided with a temperature control circuit in order to control the inner surface temperature of the chill vent degassing passage.
In this temperature control circuit, cooling water or cooling oil is generally flowed from the viewpoint of solidifying the molten material in the degassing passage, but in some cases, the cooling rate of the molten material is more precise. In order to control the temperature, it is possible to supply heated water or oil, or to adjust the flow rate. Further, a temperature sensor or an electromagnetic valve for such control may be provided.

  In such a temperature control circuit, in order to make the fluid flow in the flow path as smooth as possible and to make the temperature control performance more effective, there are substantially no branching points, confluences, dead ends, etc. It is desirable to have a continuous circuit, and it is also desirable to make the fluctuation range of the cross-sectional area of the temperature control circuit as small as possible.

And, in order to form such a continuous temperature control circuit in the chill vent block, after dividing the block on the circuit forming surface and forming the temperature control circuit in a groove shape on each of the divided surfaces, for example, It is desirable that the blocks are integrated by surface-bonding parts other than the circuits on both divided surfaces by means such as diffusion bonding, so that heat can be smoothly transferred even at the bonding surfaces. As a result, the temperature control effect is dramatically improved.
In addition, in order to surface-join the split surfaces of the chill vent block, it is also possible to apply brazing instead of the above-mentioned diffusion joining. It can be joined by heating and pressure bonding.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by these Examples.

( Reference example)
FIG. 1 shows a reference example of the chill vent insert of the present invention. The chill vent insert 1 according to the reference example is mainly composed of a fixed block 2 and a movable block 3 as shown in FIG. The gas vent path 4 is formed between the fixed block 2 and the movable block 3.

  Of the fixed block 2 and the movable block 3, on the movable block 3 side, as shown in FIG. 1B, an ejector plate 5, an ejector pin 6 fixed to the ejector plate 5, and a return are provided. A pin 7 and a coil spring 8 for urging the ejector plate 5 in the pushing direction are provided, and the ejector plate 5, the ejector pin 6, the return pin 7 and the coil spring 8 are solidified in the gas vent passage 4 of the chill vent. A mold release means for extruding the material is constructed.

  As shown in FIG. 2, the chill vent insert 1 incorporating the above releasing means is attached to an aluminum alloy die casting mold 30, and the gas vent path 4 and the cavity C of the mold 30 communicate with each other. Is arranged.

  FIGS. 3A to 3D are operation diagrams for sequentially explaining the functions of the chill vent insert 1 attached to the die casting mold 30, and FIG. 3A is a mold clamping state of the mold 30. Is shown.

  That is, in the mold-clamping state, the return pin 7 of the mold release means abuts against the fixed block 2 to move the ejector plate 5 to the left side in the figure against the elastic force of the coil spring 8, and the ejector pin 6 It is held in a state retracted from the gas vent passage 4.

  Next, when an aluminum alloy is poured into the cavity C of the mold 30, the gas in the cavity C is discharged to the outside of the mold through the gas vent path 4 of the chill vent, and into the gas vent path 4. The molten metal enters and solidifies quickly.

  When the mold 30 is opened, the ejector plate 5 is ejected by the amount of movement of the movable block 3 together with the movable mold of the mold 30 by the elastic force of the coil spring 8, as shown in FIG. Extrusion operation is performed together with the pin 6, and the mold release from the movable block 3 of the aluminum alloy solidified in the gas vent passage 4 is started simultaneously with the mold opening.

  When the mold opening further proceeds, as shown in FIG. 3 (c), the ejector plate 5 and the ejector pin 6 are pushed out to the forward limit, and the mold separation proceeds accordingly. The released alloy is also separated from the fixed block 2, and the mold release is completed as shown in FIG.

(Example)
FIG. 4 shows an embodiment of the chill vent insert according to the present invention. The chill vent insert 10 shown in the figure is mainly composed of a fixed block 12 and a movable block 3, and these fixed blocks 12 and A gas vent path 4 is formed between the movable blocks 3.

Of the fixed block 2 and the movable block 3, the mold releasing means (movable side separation) similar to the above-described reference example including the ejector plate 5, the ejector pin 6, the return pin 7 and the coil spring 8 is provided on the movable block 3 side. In this embodiment, the mold release means (fixed-side mold release means) comprising the ejector plate 15, the ejector pin 16, the return pin 17 and the coil spring 18 is also provided on the fixed block 2 side. It has.

Chill vent nesting 10 having such a structure, similarly to the above reference example, as shown in FIG. 2, attached to the die casting mold 30, and the cavity C of the gas vent passage 4 and the die 30 of the chill vent nest 10 Are arranged to communicate with each other.

  In the chill vent insert 10 according to this embodiment, the return pins 7 and 17 of both mold release means abut against each other in the mold clamping state shown in FIG. 5A, thereby resisting the elastic force of the coil springs 8 and 18. Then, the ejector plates 5 and 15 are moved in opposite directions, respectively, and the ejector pins 6 and 16 are held in the retracted state from the gas vent passage 4 respectively.

  When molten aluminum alloy is injected into the cavity C of the mold 30, the gas in the cavity C is similarly discharged to the outside of the mold through the gas vent path 4 of the chill vent, and the molten metal is discharged into the gas vent path 4. It enters and quickly solidifies in the gas vent passage 4.

Next, when mold opening of the mold 30 is started, the elastic force of the coil spring 18 installed in the fixed block 2 is larger than that of the coil spring 8 on the movable block 3 side. ), The ejector plate 15 is pushed out together with the ejector pin 16 by the amount of movement of the movable block 3 together with the movable mold of the mold 30, and the aluminum alloy solidified in the gas venting path 4 is fixed at the same time as the mold is opened. Begin demolding from block 2.
That is, the ejector plate 5 on the movable block 3 side does not operate until the ejector plate 15 on the fixed block 2 side reaches the forward limit due to the above-described difference in elastic force between the coil springs 8 and 18. It has become.

  As the mold opening proceeds, as shown in FIG. 5 (c), the ejector plate 15 and the ejector pin 16 on the fixed block 2 side reach the advance limit, and when the mold opening further proceeds, as shown in FIG. 5 (d). The ejector plate 5 and the ejector pin 6 on the movable block 3 side start to be pushed out by the elastic force of the coil spring 8 on the movable block 3 side, and the solidified aluminum alloy begins to separate from the movable block 3.

  When the mold opening is further advanced, as shown in FIG. 5E, the ejector plate 5 and the ejector pin 6 reach the forward limit, and when the mold 30 is opened, the solidified alloy is removed from the movable block 3. Is easily separated, and the mold release is completed as shown in FIG.

It is sectional drawing (a) which shows the structure of the chill vent nesting concerning the reference example of this invention, and the side view (b) of the movable block which shows the degassing road surface. FIG. 2 is an explanatory cross-sectional view showing a state where the chill vent insert shown in FIG. 1 is attached to a die casting die. (A)-(d) is the action | operation explanatory drawing which shows in order the movement at the time of the mold opening of the chill vent nest | insert shown in FIG. It is sectional drawing which shows the structure of the chill vent nesting concerning the Example of this invention. (A)-(f) is an operation | movement explanatory drawing which shows the motion at the time of the mold opening of the chill vent nest | insert shown in FIG. 4 in order. It is sectional drawing which shows arrangement | positioning of the chill vent and mold release mechanism in the conventional die-casting metal mold | die.

Explanation of symbols

1,10 Chill vent insert 4 Gas venting path 5,15 Ejector plate (mold release means)
6,16 Ejector pin (release means)
7, 17 Return pin (release means)
8,18 Coil spring (release means)
30 Mold 31 Ejector plate (release mechanism)
32 Ejector pin (release mechanism)
C cavity

Claims (4)

In a chill vent insert attached to a mold and having a gas vent passage communicating with the cavity of the mold, a mold release means for extruding the material solidified in the gas vent passage is used for the product solidified in the cavity of the mold. A chill vent insert characterized in that it is provided on both the fixed side and the movable side in a state independent of the release mechanism.   The chill vent insert according to claim 1, further comprising a temperature control circuit for adjusting an inner surface temperature of the gas vent passage. 3. The chill vent insert according to claim 1, wherein the mold is a die casting mold. 3. The chill vent insert according to claim 1, wherein the mold is an injection mold.

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