Method for pouring molten aluminum

Abstract

A pouring vessel and a pouring nozzle for providing molten metal, typically aluminum, to a shot sleeve of a die casting machine. During the process, in response to a pouring start signal, the pouring nozzle pivots through the pouring hole of the shot sleeve and the shot vessel rotates to pour molten metal into the pouring nozzle and thus into the shot sleeve. After some of the molten metal enters the shot sleeve, the process includes raising the pressure of the shot vessel and the sprue while pouring additional molten metal into the shot sleeve. Due to the design and movement of the curved or helical pouring nozzle, reduced erosion of the shot sleeve and more laminar, more uniformly distributed molten metal are achieved, and mixing of air and molten metal in the shot sleeve is reduced.

Description

[0001] Cross-reference to related applications

[0002] This PCT international patent application claims the benefit and priority of U.S. Provisional Patent Application Serial No. 63 / 533367, filed on August 18, 2023, entitled “Method for Casting Molten Aluminum,” the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a pouring nozzle for supplying molten metal to an injection sleeve (e.g., the injection sleeve of a high-pressure die casting machine), a die casting system including the pouring nozzle, and a method for die casting metal parts using the pouring nozzle. Background Technology

[0004] This section provides background information relating to this disclosure, which is not necessarily prior art.

[0005] Die casting is used to form metal parts, such as those used in vehicles. Aluminum and aluminum alloys are typically formed into parts using high-pressure die casting. During the die casting process, molten metal is poured into an injection sleeve and then injected into a mold cavity for shaping. A ladle or other device typically supplies the molten metal to the injection sleeve. The molten metal enters through the gating orifice of the injection sleeve, and a punch presses the molten metal from the injection sleeve into the mold cavity.

[0006] It has been found that over time, a portion of the injection sleeve bushing located below the gating orifice may be eroded by the molten metal. For example, typically when casting parts with aluminum, 12 kg of molten aluminum can be poured through the gating orifice in just 7 seconds. However, when manufacturing giant castings, up to 220 kg of aluminum needs to be poured in just 10 seconds. Due to the large amount of molten metal poured in such a short time, air may mix with the molten metal, which could affect the mechanical properties of the cast parts. However, slower pouring also leads to heat loss, which is undesirable as it can reduce elongation and affect mechanical properties. Therefore, improvements to the die-casting process are desired. Summary of the Invention

[0007] This section provides a general overview of the disclosure and should not be construed as a complete and exhaustive list of all purposes, aspects, features, and advantages associated with the disclosure.

[0008] One aspect of the invention provides a gating nozzle for supplying molten metal to an injection sleeve that delivers the molten metal to a die-casting machine. The gating nozzle has a curved (preferably helical) shape and is capable of providing reduced erosion of the injection sleeve and a more laminar, more uniformly distributed molten metal, as well as reduced mixing of air and molten metal within the injection sleeve.

[0009] An assembly for conveying molten metal to a die-casting machine is also provided. The assembly includes an injection sleeve having a channel extending from a first end to a second end for conveying molten metal toward the die-casting machine. The injection sleeve also has a gating orifice located between the first and second ends for receiving the molten metal. A gating nozzle extends through the gating orifice for providing molten metal into the channel of the injection sleeve, and the gating nozzle has a curved (preferably helical) shape. The gating nozzle is designed to provide a desired amount of molten metal within a specified time while minimizing the amount of air mixed into the molten metal.

[0010] A method for die-casting metal is also provided. The method includes conveying molten metal through a gating nozzle and into an injection sleeve. The gating nozzle extends through a gating orifice in the injection sleeve, which conveys the molten metal to a die-casting machine, and the gating nozzle has a curved (preferably spiral) shape.

[0011] Other application areas will become apparent from the descriptions provided herein. The descriptions and specific examples in this overview are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0012] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure. The inventive concepts associated with this disclosure will be more readily understood by referring to the following description in conjunction with the accompanying drawings, wherein:

[0013] Figure 1 The illustration shows a conventional die-casting machine, which includes a ladle for pouring molten metal into an injection sleeve;

[0014] Figure 2 This is a perspective view of a conventional die-casting machine, showing molten metal in the cavity of the injection sleeve; and

[0015] Figures 3A-3C The illustration shows a die-casting machine including an injection vessel and a pouring nozzle according to an example embodiment. Detailed Implementation

[0016] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments are provided only so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous specific details, such as examples of specific parts, apparatus, and methods, are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that specific details are not necessary, example embodiments may be embodied in many different forms, and these should not be considered as limiting the scope of this disclosure. In some example embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0017] One aspect of this subject matter discloses a die-casting assembly 10, such as a high-pressure die-casting assembly or a high-pressure vacuum die-casting assembly, which can be used to cast parts, such as parts formed of aluminum or aluminum alloys, with molten metal 12. However, this disclosure may relate to other types of die-casting assemblies. Figure 1 and Figure 2 An example of a conventional pressure die-casting assembly is shown. The die-casting assembly includes an injection sleeve 14 having a gating orifice 16 for receiving molten metal 12. The injection sleeve 14 may also be referred to as an injection sleeve bushing. According to this conventional assembly, a ladle 18 is used to pour molten metal 11 through the gating orifice 16, and a punch 20 presses the molten metal 12 through the injection sleeve 14 and into the mold cavity to form a part.

[0018] According to this disclosure, an improved method is provided for supplying molten metal 12 to an injection sleeve 14. Instead of pouring the molten metal 12 directly from a ladle 18 or other means into the injection sleeve 14, a pouring nozzle 22, typically having a curved shape (preferably a helical shape), is used to convey the molten metal 12 from an injection vessel or a metering feeder 24 into the injection sleeve 14. Examples of the pouring nozzle 22 and the injection vessel 24 are provided in... Figures 3A-3C As shown in the diagram. The pouring nozzle 22 can have various shapes and cross-sections to achieve the desired flow of molten metal 12. The pouring nozzle is formed of metal, ceramic, or another type of material already used to form ladle. Furthermore, if desired, the injection vessel 24 can be replaced by a typical metering feeder or other filling device.

[0019] As shown, the injection vessel 24 receives molten metal 12 and is rotatable to pour the molten metal 12 into the pouring nozzle 22. A holding furnace is typically used to supply the molten metal 12 during the casting process. The injection vessel 24 and the pouring nozzle 22 originate outside the injection sleeve 14. When the die-casting machine's press is shut off, and in response to a pouring start signal, the pouring nozzle 22 pivots and extends through the pouring orifice 16 into the cavity of the injection sleeve 14. The injection vessel 24 rotates and pours molten metal into the pouring nozzle 22 and thus into the injection sleeve 14. After some molten metal has entered the injection sleeve 14, the injection vessel 24 and the pouring nozzle 22 rise upward relative to the pouring orifice 16, allowing additional molten metal 12 to be poured into the pool and dispersed within the injection sleeve 14. This upward movement also helps reduce splashing and mixing of air with the molten metal 12. The movement of the pouring nozzle 22 and the injection container 24 is programmable and can therefore be moved in other ways and directions.

[0020] During the pouring step, the molten metal 12 does not concentrate in a single location within the cavity of the injection sleeve 14, thus reducing erosion. In other words, the movement of the pouring nozzle 22 distributes the heat dissipation from the molten metal 12 over a larger area. The pouring nozzle 22 also provides a more laminar rather than turbulent flow of molten metal 12 into the injection sleeve 14. Therefore, less air mixes with the molten metal 12 during the pouring step. Furthermore, at the end of the pouring step, the warmer molten metal 12 from the injection vessel 24 mixes with the cooler molten metal 12 located at the end of the injection sleeve 14, which improves the mechanical properties of the finished cast part. According to a preferred embodiment, the amount of molten aluminum poured into the injection sleeve is at least 1.21 liters per second, or up to 220 kg within 10 seconds.

[0021] In addition to the injection vessel 24 and the gating nozzle 22, the die-casting assembly may also include a larger gating orifice 16 or a gating orifice 16 with a more modern design compared to conventional gating orifices. The gating orifice 16 in the injection sleeve 14 is designed to allow the desired movement of the gating nozzle 22.

[0022] Another aspect of this disclosure provides a method for die-casting a metal component using the injection vessel 24 and pouring nozzle 22 of this disclosure. The method includes supplying molten metal 12 from a holding furnace to the injection vessel 24, and then pouring the molten metal 12 from the injection vessel 24 into the pouring nozzle 22. In response to a pouring start signal, the pouring nozzle 22 pivots through a pouring orifice 16 and into an injection sleeve 14, and the injection vessel 24 rotates to pour the molten metal 12 into the injection sleeve 14. After some molten metal 12 has entered the injection sleeve 14, the method includes raising the injection vessel 24 and the pouring nozzle 22 while pouring additional molten metal 12 into the injection sleeve 14.

[0023] As discussed above, the systems and methods of this disclosure provide reduced erosion of the injection sleeve 14 and a more laminar, more uniformly distributed molten metal 11, and reduce the mixing of air and molten metal 12 in the injection sleeve 14.

[0024] More specifically, the system and method reduce the amount of air mixed into the molten aluminum or other metal during the filling of the injection sleeve 14 by providing laminar flow of the material. This reduces the likelihood of porosity in the final casting.

[0025] The system and method also improve thermal diffusion within the injection sleeve 14 after filling, thereby reducing the likelihood of molten aluminum or other metals cooling at the distal end of the injection sleeve 14.

[0026] This system and method enable faster casting of large quantities of aluminum or other metals, such as in giant castings. Typical high-pressure die castings weigh approximately 12 kg to 20 kg, while giant castings can weigh 200 kg and larger.

[0027] Furthermore, the system and method reduce thermal saturation of molten aluminum or other metals in localized areas of the injection sleeve bushing 14. By providing a larger landing area for the molten aluminum or other metals, corrosion of the injection sleeve 14 is significantly reduced, thereby reducing maintenance costs and machine downtime for repairing the injection sleeve 14.

[0028] It should be understood that the foregoing description of the embodiments is provided for illustrative purposes. In other words, this disclosure is not intended to be exhaustive or limiting. Various elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable and can be used in a chosen embodiment, even if not specifically shown or described. These elements or features can also be varied in many ways. Such changes should not be considered as departing from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. A pouring nozzle for providing molten metal to a shot sleeve that delivers the molten metal to a die casting machine, wherein a curved shape of the pouring nozzle provides laminar flow of the molten metal.

2. The gate as defined in claim 1, wherein The curved shape is helical.

3. The gate as defined in claim 1, wherein The pouring nozzle is formed of ceramic or metal.

4. The gate as defined in claim 1, wherein, Movement of the pouring nozzle is programmable.

5. A pouring system for providing molten metal to a shot sleeve, comprising the pouring nozzle of claim 1.

6. An assembly for delivering molten metal to a die casting machine, comprising: a shot sleeve having a passageway extending from a first end to a second end for delivering the molten metal toward the die casting machine, the shot sleeve having a pouring hole between the first end and the second end for receiving the molten metal, a pouring nozzle extending through the pouring hole to provide the molten metal to the passageway of the shot sleeve, and the pouring nozzle having a curved shape.

7. The assembly of claim 6, wherein, The curved shape is helical.

8. The assembly of claim 6, comprising a shot pot for containing the molten metal and pouring the molten metal into the pouring nozzle and the shot sleeve, the shot pot being rotatable and movable toward and away from the shot sleeve.

9. The assembly of claim 6, wherein, The pouring nozzle is movable into and out of the passageway of the shot sleeve.

10. The assembly of claim 6, wherein, The die casting machine is a high pressure vacuum die casting machine.

11. The assembly of claim 6, comprising a holding furnace for containing the molten metal and pouring the molten metal into the shot pot.

12. The assembly of claim 6, wherein, The molten metal is aluminum or an aluminum alloy.

13. The assembly of claim 6, wherein, The pouring nozzle is formed of ceramic or metal.

14. A method for die casting metal, comprising the steps of: delivering molten metal through a pouring nozzle and into a shot sleeve, wherein the pouring nozzle extends through a pouring hole of the shot sleeve, the shot sleeve delivers the molten metal to a die casting machine, and the pouring nozzle has a curved shape.

15. The method of claim 14, wherein, The curved shape is helical.

16. The method of claim 14, wherein, The pouring nozzle is pivoted through the pouring hole and into a passageway of the shot sleeve prior to a pour start signal, and pours the molten metal from a shot pot into the pouring nozzle in response to the pour start signal.

17. The method of claim 16, comprising moving the shot pot and the pouring nozzle outward relative to the shot sleeve after pouring some of the molten metal into the shot sleeve.

18. The method of claim 14, wherein, The molten metal is aluminum or an aluminum alloy.

19. The method of claim 14, wherein, The shot sleeve delivers the molten metal to a high pressure die casting machine.

20. The method of claim 14, wherein, The pouring nozzle is formed of ceramic or metal.

Images