Casting apparatus and casting method

Abstract

Provided is a casting device and a casting method that can reuse hydrogen recovered in the casting device. A casting device includes: a mold; a hydrogen burner that can heat the mold; and a hydrogen recovery device that can recover hydrogen contained in the casting device, the hydrogen recovered by the hydrogen recovery device being supplied to the hydrogen burner. A casting method uses the casting device, burns the hydrogen recovered in the casting device, and uses the burned hydrogen to heat the mold.

Description

Technical Field

[0001] This invention relates to a casting apparatus and a casting method. Background Technology

[0002] It is known that products cast from molten metal containing impurities such as hydrogen may suffer from casting defects due to the influence of bubbles and other factors.

[0003] Patent Document 1 discloses a low-pressure casting apparatus comprising a mold for forming a cavity for casting, a molten metal holding furnace for heating and holding molten metal filled in the cavity, and a degassing mechanism for removing gas mixed in the molten metal to the outside. This low-pressure casting apparatus includes a sealing mechanism for airtightly mounting the degassing mechanism relative to the molten metal holding furnace.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2-137659 Summary of the Invention

[0005] In the casting apparatus described in Patent Document 1, the gas (especially hydrogen) recovered by the degassing mechanism is removed but not reused.

[0006] The purpose of this invention is to provide a casting apparatus and casting method that can reuse hydrogen recovered within the casting apparatus.

[0007] One way to achieve the above objective is a casting apparatus comprising: a mold; a hydrogen burner capable of heating the mold; and a hydrogen recovery unit capable of recovering hydrogen contained within the casting apparatus, wherein the hydrogen recovered by the hydrogen recovery unit can be supplied to the hydrogen burner.

[0008] Furthermore, one way to achieve the above objective is a casting method that uses the casting apparatus to burn hydrogen recovered from the casting apparatus to heat the mold.

[0009] In the casting apparatus and casting method of this invention, hydrogen recovered from the mold and molten metal can be burned and reused for mold preheating, thus eliminating the safety risks associated with storing the recovered hydrogen. Therefore, the casting apparatus and casting method of this invention enable the safe and efficient manufacture of cast products.

[0010] Invention Effects

[0011] According to the present invention, a casting apparatus and casting method capable of reusing hydrogen recovered within the casting apparatus can be provided. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating an example of the casting apparatus involved in this embodiment.

[0013] Figure 2 This is a diagram illustrating an example of the casting method involved in this embodiment. Detailed Implementation

[0014] When manufacturing castings using molds, the presence of impurities such as gases or oxides in the molten metal (e.g., molten aluminum) can sometimes lead to pinholes caused by bubbles or obstruction of molten metal flow due to impurities. As a result, the mechanical properties of the manufactured castings can sometimes be reduced, making it important to remove these impurities from the molten metal (e.g., slag removal or degassing).

[0015] In the casting apparatus described in Patent Document 1, a degassing mechanism removes gases (e.g., hydrogen) mixed in with the molten metal to the outside, but the recovered gases are only removed and not reused.

[0016] Furthermore, to stabilize product quality and protect the mold, preheating of the mold is usually performed before casting begins. Various methods exist for heating the mold, but so far, heating with a gas burner has been the primary method. However, concerns remain regarding the environmental impact of the exhaust gases from gas burners.

[0017] On the other hand, such as Figure 1 As shown, the casting apparatus of the present invention (hereinafter also referred to as this casting apparatus) uses a hydrogen burner 2 with hydrogen gas to preheat the mold 1, thus significantly reducing the amount of carbon dioxide emitted in the combustion exhaust, thereby reducing the environmental impact. Furthermore, this casting apparatus includes a hydrogen recovery unit 8, which has a degassing mechanism 5 for recovering hydrogen remaining in the mold 1 or molten metal, and the hydrogen recovered by the hydrogen recovery unit 8 can be reused for preheating the mold 1. In this casting apparatus, even if unburned hydrogen is generated and diffuses into the mold during mold preheating by the hydrogen burner 2, the unburned hydrogen can be recovered into the hydrogen recovery unit 8 using the aforementioned degassing mechanism 5. Then, the unburned hydrogen can be reused for preheating the mold 1. Furthermore, in this casting apparatus, by feeding back the quality data of the actually manufactured casting products to the casting process, adjusting the degassing treatment (hydrogen recovery amount) or the mold preheating time, etc., more economical, faster, and higher-quality casting products can be manufactured.

[0018] Thus, casting products manufactured using this casting equipment become casting products that are economical, environmentally friendly, and of excellent quality.

[0019] Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments. Furthermore, for clarity, the following description and drawings are appropriately simplified. Figure 1 This is a diagram (schematic diagram) illustrating an example of the casting apparatus according to this embodiment. Furthermore, Figure 2 This is a flowchart illustrating an example of the casting method involved in this embodiment.

[0020] like Figure 1 As shown, the casting apparatus 10 according to the present invention includes: a mold 1; a hydrogen burner 2 capable of heating the mold 1; and a hydrogen recovery unit 8 capable of recovering the hydrogen contained within the casting apparatus 10. Furthermore, this casting apparatus can also include a hydrogen supply unit 7 for supplying hydrogen to the hydrogen burner 2, a degassing mechanism 5 for recovering the hydrogen contained within the casting apparatus 10, and a sleeve pin 6 for extruding molten metal into the mold. Moreover, this casting apparatus can appropriately include structures such as a molten metal holding furnace (not shown) for heating and holding the molten metal, as is common in conventionally known casting apparatuses. Furthermore, this casting apparatus can supply hydrogen recovered by the hydrogen recovery unit 8 to the hydrogen burner 2. Moreover, this casting apparatus can use the degassing mechanism 5, etc., to recover unburned hydrogen used when using the hydrogen burner 2 via the hydrogen recovery unit 8. Hereinafter, the main components constituting this casting apparatus will be described, but for other components, conventionally known components commonly used in the field of casting apparatuses can be used in the same way, and therefore descriptions are omitted.

[0021] The shape or material of mold 1 can be appropriately set according to the shape or material of the casting product to be manufactured, without special limitations, and any of small, medium, or large molds can be used. For example, a large mold with a height of 2m or more can be used as mold 1.

[0022] The hydrogen burner 2 can be used without particular restrictions as long as it can heat (preheat) the mold 1. In this casting apparatus, hydrogen is used to preheat the mold 1, thus reducing the environmental impact caused by combustion exhaust. Figure 1The diagram shows a hydrogen burner 2, which uses hydrogen supplied by a hydrogen supply unit 7 (such as a hydrogen tank) or a hydrogen recovery unit 8, positioned at both the upper and lower parts of the mold. The structure and configuration of the hydrogen burner 2 can be appropriately set and are not particularly limited. In this casting apparatus, in addition to the hydrogen supplied from the hydrogen supply unit 7, hydrogen recovered from the mold 1 (more specifically, the mold product section 3 or the mold sleeve section 4), molten metal (not shown), and the molten metal holding furnace can also be supplied to the hydrogen burner 2 for reuse during mold preheating. Furthermore, the hydrogen recovered from the mold 1 can be unburned hydrogen used when using the hydrogen burner 2, or hydrogen contained in the molten metal holding furnace or the mold that may cause casting defects. Thus, this casting apparatus provides a system capable of reusing hydrogen recovered through the degassing treatment of the molten metal for mold preheating. In addition, from the perspective of maintaining the quality of the cast products, hydrogen can be added to the molten metal from the hydrogen supplier 7 as needed, and the amount of hydrogen added can be controlled according to the quality data of the cast products described later.

[0023] Therefore, this casting apparatus can further reduce the safety risks caused by maintaining hydrogen tanks for hydrogen supply or recovery for extended periods, and can also reduce the restrictions on the placement of locations where gas exchange is required.

[0024] The hydrogen recovery unit 8 is equipped with a degassing mechanism 5 that can recover hydrogen remaining in the casting apparatus 10, more specifically, in the mold 1 and in the molten metal. In this casting apparatus, the hydrogen recovered by the hydrogen recovery unit 8 can be supplied to the hydrogen burner 2.

[0025] The degassing mechanism is not particularly limited as long as it can remove (and recover) the (unburned) hydrogen remaining in the mold 1, more specifically, the mold product section 3 or the mold sleeve section 4, and can degas (and recover) the gas (hydrogen) in the molten metal (e.g., in the molten metal holding furnace).

[0026] exist Figure 1In the diagram, a pressure reducing valve is shown as the degassing mechanism 5. This casting apparatus can have the following structure: it detects unburned hydrogen remaining in the mold product section 3 or the mold sleeve section 4, and controls the degassing time and pressure of the pressure reducing device within the mold. Specifically, for example, after preheating the mold 1 using a hydrogen burner 2 with a hydrogen flame, if unburned hydrogen remains in the mold sleeve section 4 (pouring sleeve), the pressure reducing valve, as the degassing mechanism 5, can remove and recover the hydrogen. Furthermore, this casting apparatus can also have an air purging mechanism as a degassing mechanism, which can efficiently remove and recover hydrogen that cannot be removed by air purging. Thus, this casting apparatus can recover unburned hydrogen used when using the hydrogen burner 2 via the hydrogen recovery unit 8, and can also reuse this unburned hydrogen for mold preheating, achieving safe and efficient casting. This casting apparatus can be a low-pressure casting apparatus.

[0027] In addition to the degassing mechanism, the apparatus can also include devices for degassing the molten metal, such as devices for blowing inert gases like argon or nitrogen into the molten metal, and rotating devices for further promoting the degassing process. Furthermore, this casting apparatus can utilize centrifugal force for degassing the molten metal. Various devices can be used for blowing inert gases, such as spray guns, perforated plugs, and rotary degassing devices. Thus, in this casting apparatus, the hydrogen removed from the molten metal and recovered to the hydrogen recovery unit 8 through the degassing process can be reused for mold preheating, achieving economical, environmentally friendly, and efficient casting. Furthermore, the gas recovered through the degassing process may contain other gases besides hydrogen, such as oxygen and nitrogen, but hydrogen is preferred as the main component. This casting apparatus can be equipped with a device (component) for recovering (extracting) hydrogen only from the recovered gas from the degassing process, as needed.

[0028] Furthermore, this casting apparatus can also have a mold management system, which controls the amount of hydrogen recovered in the hydrogen recovery unit 8 and the preheating time corresponding to the initial temperature of the mold 1 based on the quality data of the cast products manufactured.

[0029] As described above, the hydrogen recovery amount can include hydrogen recovered through degassing of the molten metal and hydrogen recovered from unburned hydrogen remaining in the mold. Therefore, this casting apparatus can monitor (record) these hydrogen recovery amounts in real time and control the optimal hydrogen recovery amount based on the quality data of the cast product, thereby enabling the reuse of residual hydrogen for mold preheating and achieving safe and efficient production. Furthermore, as mentioned above, mold preheating is important from the viewpoint of product quality stabilization and mold protection; therefore, recording the initial temperature of the mold and controlling the optimal preheating time based on the quality data of the cast product enables economical and high-quality casting. The control device (control system) that controls the hydrogen recovery amount in the hydrogen recoverer 8 and the preheating time corresponding to the initial temperature of the mold 1 based on the quality data of the cast product can utilize conventionally known systems without particular limitation, as long as these functions are achieved.

[0030] Thus, this casting apparatus continuously monitors the amount of unburned hydrogen remaining in the mold product section 3 or the mold sleeve section 4, or the amount of hydrogen recovered from the molten metal through degassing. Based on this information, feedback control is applied to the processing time (depressurization time) or power (depressurization pressure) of the degassing mechanism (e.g., a pressure reducing device or an inert gas blowing device) within the mold or molten metal holding furnace. For example, taking the recovery of unburned hydrogen from the mold as an example, the mold is preheated with a hydrogen flame, and if unburned hydrogen remains in the casting sleeve, the pressure reducing valve is activated to remove and recover the hydrogen. Furthermore, by using the pressure reducing valve, hydrogen that cannot be removed by air purging can also be efficiently removed and recovered. At this time, the amount of hydrogen recovered is appropriately adjusted based on the quality data of the cast product. Feedback control can then be implemented to reuse the recovered unburned hydrogen for mold preheating. Similarly, feedback control can also be applied to the degassing process within the molten metal.

[0031] The casting method of the present invention (hereinafter also referred to as the casting method) uses the casting apparatus and is a casting method in which hydrogen recovered from the casting apparatus is burned to heat the mold.

[0032] use Figure 2 An example of this casting method will be described, but the invention is not limited to this example.

[0033] First, during casting, mold 1 is opened (step 1: S1). Then, the hydrogen burner 2 is switched on to begin preheating of mold 1 (step 5: S5). At this time, the hydrogen burner 2 is a hydrogen combustion device, so sometimes unburned hydrogen is produced (step 6: S6), and sometimes this unburned hydrogen diffuses into mold 1 (step 7: S7). In this case, the unburned hydrogen is recovered by hydrogen recovery device 8 (step 3: S3). Then, if the preheating of mold 1 is completed, the hydrogen burner 2 is switched off (step 8: S8). Next, mold 1 is closed (step 9: S9), molten metal is supplied (poured) into mold 1 (step 4: S4), and casting begins (step 10: S10).

[0034] Here, the molten metal is also subjected to the following processing in parallel. That is, a purification treatment of the molten metal is performed (step 2: S2) to improve the quality of the molten metal. This purification treatment can be carried out in accordance with the treatments known in the casting field, such as slag removal treatment or degassing treatment for the purpose of removing impurities such as gases or oxides from the molten metal. Then, the hydrogen gas removed by the degassing treatment of the molten metal is recovered (step 3: S3) and reused in the hydrogen burner 2. Next, the molten metal with improved quality after purification treatment is poured into the mold 1 (step 4: S4), and casting begins (step 10: S10).

[0035] Then, the quality of the obtained casting product is confirmed (step 11: S11). As mentioned above, when hydrogen is mixed into the molten metal, casting defects caused by bubbles may occur on the surface. Therefore, by feeding back the quality data of the casting product, controlling the amount of hydrogen recovered in S3 and the preheating time (combustion amount and burner running time) corresponding to the initial temperature of mold 1 in S5 to S8, efficient, economical and high-quality casting can be achieved.

[0036] Thus, in this casting apparatus and casting method, the hydrogen recovered in the casting apparatus can be reused, enabling efficient, economical and high-quality casting.

[0037] Furthermore, the present invention is not limited to the above-described embodiments, and appropriate modifications can be made without departing from the spirit of the invention.

[0038] Symbol Explanation

[0039] 1-Mold, 2-Hydrogen burner, 3-Mold product department, 4-Mold sleeve department, 5-Degassing mechanism, 6-Sleeve pin, 7-Hydrogen supplier, 8-Hydrogen recovery unit, 10-Casting device.

Claims

1. A casting apparatus, characterized in that, have: Mold; A hydrogen burner capable of heating the mold; and A hydrogen recovery unit that can recover hydrogen contained within the casting equipment. The hydrogen recovered by the hydrogen recovery unit can be supplied to the hydrogen burner.

2. The casting apparatus according to claim 1, characterized in that, The hydrogen recovery unit has a degassing mechanism that can recover hydrogen remaining in the mold and molten metal.

3. The casting apparatus according to claim 1, characterized in that, Unburned hydrogen from the use of the hydrogen burner can be recovered through the hydrogen recovery unit.

4. The casting apparatus according to claim 1, characterized in that, The amount of hydrogen recovered in the hydrogen recoverer and the preheating time corresponding to the initial temperature of the mold can be controlled based on the quality data of the cast product.

5. A casting method, comprising using the casting apparatus according to any one of claims 1 to 4, characterized in that, The hydrogen recovered from the casting apparatus is burned to heat the mold.

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