Gas-venting device for metal die-casting apparatus

Abstract

To pursue a mechanical structure that quickly and easily vents air and gas inside the cavity and a runner of a die-casting apparatus that molds a molten metal material to the outside of the apparatus without using a complex device.SOLUTION: In a die-casting apparatus in which molten metal in a cylinder 1 is delivered to a cavity 8 inside a metal mold by a plunger, a V-shaped notch 5 is formed at an end 2 of the cylinder 1 which is fixed to a stationary mold 3 and has an opening facing a movable mold 4 from an inner surface of the end 2 of the cylinder 1 toward the end 2, and an exhaust groove 6 for exhausting air or gas from a terminal on the end 2 of the notch 5 to the outside of the cylinder 1 is provided. Air and gas compressed by the delivered molten metal are exhausted outside the die-casting apparatus via the notch 5 and the exhaust groove 6, and air in the runner 7 and the cavity 8 is also exhausted by the decompression exhaust.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a venting system for metal die casting equipment which provides effective evacuation of the runners and cavities. [Background technology]

[0002] Although metal die casting technology is a relatively new industrial technology, as a result of many improvements and the accumulation of technical knowledge, it has become technically common knowledge that better molding results can be obtained by lowering the air pressure inside the mold or other equipment parts as much as possible to maintain a state close to a vacuum, or by filling or evacuating an inert gas inside the mold cavity, one of which is called vacuum die casting or high vacuum die casting, and various auxiliary technologies for this purpose are also being researched. However, due to issues such as the cost of equipment, the effectiveness and handling of the equipment, and maintenance issues, none of the ideas can be said to be perfect, and a cheaper and more reliable exhaust device for the inside of the mold is desired. Such conventional technology is shown in Patent Document 1 and Patent Document 2.

[0003] In addition, in various die casting processes, regardless of the material of the molten material, past experiments have shown that the gas generated inside the filled cavity and the gas present inside the cavity deform the material and circulate, and the circulation stops when the temperature of the molten material drops, and finally the molded product is completed. An example of this is shown in Patent Document 3. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5454068 [Patent Document 2] Japanese Patent Application Publication No. 7-40027 [Patent Document 3] Patent No. 5413780 [Patent Document 4] Patent No. 4085128 [Patent Document 5] Patent No. 4096327

[0005] Summary of the Invention [Problem to be solved by the invention]

[0006] In a typical conventional metal die casting machine shown in Figure 7, air, steam, or other gases and liquids that exist in the cavity C and other spaces inside the die are pushed by molten metal H, such as aluminum, that is filled into the die by plunger P from sleeve S, and are discharged to the outside of the die to some extent from appropriately installed exhaust port B. However, it is not possible to remove all of the gas that has already been caught up in the molten metal H inside sleeve S, or the new substances that are generated when they come into contact with the high-temperature molten metal inside the die, which causes poor flow and voids, lowering the product yield.

[0007] In order to improve this situation, technologies such as vacuum die casting and its further improvement, high vacuum die casting, have been proposed. For example, in a typical die casting machine as shown in Figure 7, the gas inside cavity K is actively released to reduce the internal pressure and improve the flow of the molten metal. Furthermore, by increasing the degree of vacuum inside cylinder C and cavity K, it is possible to remove degassing and entrapped air from the molten metal H, and to minimize harmful substances generated by release agents and lubricants. In this way, efforts have been made to obtain die cast products with fewer casting holes. Although some effect has been achieved, the increase in the cost of the die casting machine and the cost of processing the molds has not been commensurate with the remarkable improvement in yield. Therefore, on-site production continues to use conventional technology, incorporating various on-site know-how, and performing die casting while assuming a certain degree of poor yield.

[0008] Through continuous experimentation and research, the inventors have succeeded in reducing the pressure inside the runner or cavity of a molding device that uses heated fluid material by utilizing a notch to rapidly reduce the pressure, as shown in Patent Documents 4 and 5, and have gradually expanded the range of application.However, for die casting using metals such as aluminum as the raw material, they have come to invent a new gas venting device structure from the standpoint of the weight of the material, processing temperature, processing pressure, etc. [Means for solving the problem]

[0009] In the conceptual diagram of a conventional die casting machine shown in Figure 7, C is a cylinder in which plunger D can slide, which is formed integrally with fixed die F, and the inner end of cylinder C opens into runner R which continues to cavity K formed by fixed die F and movable die M. P is an ejection pin installed in movable die M, and N is a core installed in movable die M. Furthermore, L is a ladle, and H is a material made of molten metal that is supplied into cylinder C by ladle L.

[0010] In such a die casting apparatus, the notch-type gas venting device that the inventor has developed thus far can be installed at any position in the runner R and the cavity K. However, such a method requires notch processing for each die, which may affect manufacturing costs.

[0011] Taking such problems into consideration, all of the notches used for venting are placed on the inner end of cylinder C facing movable mold M, so that when the molten metal H fed by plunger D from the outer end of the cylinder reaches the inner end of cylinder C, the gas is suddenly vented, and the resulting reduced pressure in runner R and cavity K can be used to carry out rapid and sufficient molding processing. Effect of the Invention

[0012] According to the present invention, a degassing device can be obtained which has a very simple structure, is low-cost and can reliably vent the cavity of a metal die-casting device, can be used without being picky about the material, and can be used without being replaced when changing the mold.

[0013] [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a mold in which the embodiment of FIG. 1 is installed. [Diagram 3] FIG. 3 is a perspective view of waste material formed at the inner end of the cylinder of FIG. 2 during molding. [Figure 4] FIG. 4 is a perspective view of a second embodiment of the present invention. [Diagram 5] FIG. 5 is a partially enlarged perspective view of the object shown in FIG. 4. [Figure 6] FIG. 11 is a cross-sectional view showing the state where the second embodiment of the present invention is installed in a mold. [Figure 7] FIG. 1 is a schematic cross-sectional view of a typical metal die casting device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A structure is obtained in which a plunger D is inserted into one end of a cylinder C for supplying material to a die casting device, and multiple V-shaped notches are provided near the other end from the inner surface of the other end toward the other end, and exhaust passages are drilled continuously from the open ends of the other ends of the notches to the outside of the die casting device.This allows the gas between the material and the other end of the cylinder D to be quickly exhausted to the outside of the die casting device when the plunger D feeds the material, and also exhausts gas from within the runner R and cavity K at the same time. EXAMPLES

[0016] In the first embodiment shown in Figures 1 and 2, 1 is a cylinder, 2 is an end of the cylinder 1 which is fixed to the fixed die 3 and the end opens to the movable die 4. 5 is a V-shaped notch squeezed from the inner surface of the end 2 of the cylinder 1 toward the end 2, 6 is an exhaust groove for discharging air or gas from the end of the notch 5 on the end 2 to the atmosphere outside the cylinder 1. 7 is a runner, and 8 is a cavity.

[0017] When the molten metal filled in cylinder 1 in Figure 2 is pressurized from the right of cylinder 1 to the left in the figure by a plunger (not shown), the metal compresses the air and gas to the left and exhausts them to the outside of the die casting apparatus through notch 5, exhaust groove 6, and the exhaust passage gap appropriately narrowed between fixed die 3 and movable die 4, and the exhaust caused by this sudden reduction in pressure also exhausts the air in cavity 8 to the outside of the die casting apparatus through runner 7.

[0018] At the same time, the molten metal pressurized inside the cylinder 1 is pressure-filled into the cavity 8 through the runner 7, completing the molded product. The metal block between the end of the cylinder 1 and the runner 7 that is molded integrally with the molded product is as shown in Figure 3, with a disk portion 1' corresponding to the inner end of the cylinder 1, a protrusion 5' corresponding to the notch 5, and a rectangular column portion 7' ​​corresponding to the runner 7 formed as shown in the figure. EXAMPLES

[0019] In the second embodiment shown in Figures 4 to 6, whereas the end 2 in the first embodiment was a ring-shaped flat surface, the end 2a has a ring-shaped curved surface, and is an example of a design that improves the flexibility of the fit with the movable mold 4. By forming a crescent-shaped notch 5a and an exhaust groove 6 in the curved surface 2a, an exhaust action similar to that of the first embodiment can be obtained. [Industrial Applicability]

[0020] Since the present invention has a structure that can be easily applied to all metal die casting equipment, it can provide high-quality die casting products at low cost and its applicability is extremely widespread. [Explanation of symbols]

[0021] 1. Cylinder 2. End 3...Fixed type 4...Movable type 5...Notch 6. Exhaust duct 7. Runner 8. Cavity

Claims

1. In a metal die casting apparatus in which molten metal is filled into a cylinder (1) and pushed out with a plunger to deliver it to a cavity (8), a notch (5) is formed in the end (2) of the cylinder (1) mounted on a fixed mold (3) facing a movable mold (4), the end (2) being formed with a notch (5) that opens from the inside of the cylinder (1) to the end (2), and an exhaust groove (6) is formed on the end (2) connected to the end of the notch (5) on the end (2), the exhaust groove (6) is opened to the atmosphere, and the inside of the cylinder (1) is connected to a runner (7) and the cavity (8). This gas venting device for a metal die casting apparatus comprises

2. 2. A gas venting device for a metal die casting apparatus according to claim 1, wherein the end portion (2) is formed with an angled curved surface.

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