Casting apparatus and casting method

Abstract

To provide a casting apparatus and casting method that can reuse hydrogen gas recovered within the casting apparatus. [Solution] A casting apparatus comprising a mold 1, a hydrogen combustor 2 capable of raising the temperature of the mold 1, and a hydrogen recoverer 8 capable of recovering hydrogen contained in the casting apparatus 10, wherein the hydrogen recovered by the hydrogen recoverer 8 can be supplied to the hydrogen combustor 2. A casting method using the casting apparatus 10, in which the hydrogen recovered from within the casting apparatus 10 is burned and used to raise the temperature of the mold 1.

Description

Technical Field

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[0001] The present disclosure relates to a casting apparatus and a casting method.

Background Art

[0002] It is known that products cast using molten metal containing impurities such as hydrogen gas may have casting defects due to the influence of bubbles and the like. Patent Document 1 discloses a low-pressure casting apparatus including a mold that defines a cavity for a casting, a molten metal holding furnace that heats and holds the molten metal filled in the cavity, and a degassing mechanism that removes gas mixed in the molten metal to the outside. The low-pressure casting apparatus includes sealing means for airtightly attaching the degassing mechanism to the molten metal holding furnace.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the casting apparatus described in Patent Document 1, the gas (particularly hydrogen gas) recovered by the degassing mechanism is only removed and not reused.

[0005] An object of the present disclosure is to provide a casting apparatus and a casting method capable of reusing hydrogen gas recovered in the casting apparatus.

Means for Solving the Problems

[0006] One aspect for achieving the above object is a casting apparatus including a mold, a hydrogen combustor capable of raising the temperature of the mold, and a hydrogen recovery device capable of recovering hydrogen contained in the casting apparatus, wherein the hydrogen recovered by the hydrogen recovery device can be supplied to the hydrogen combustor. <00​ Furthermore, one embodiment for achieving the above objective is a casting method using the casting apparatus, wherein hydrogen recovered from within the casting apparatus is burned and used to raise the temperature of the mold.

[0008] In the casting apparatus and casting method described herein, hydrogen recovered from the mold and molten metal can be burned and reused for preheating the mold, eliminating the need to consider safety risks associated with the storage of recovered hydrogen gas. Therefore, the casting apparatus and casting method described herein enable the safe and efficient manufacture of cast products. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a casting apparatus and a casting method that can reuse hydrogen gas recovered within the casting apparatus. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram illustrating an example of a casting apparatus according to this embodiment. [Figure 2] This figure illustrates an example of a casting method according to this embodiment. [Modes for carrying out the invention]

[0011] When manufacturing cast products using molds, if impurities such as gases or oxides are mixed into the molten metal (e.g., molten aluminum), pinholes may occur due to air bubbles, or the flow of the molten metal may be obstructed by the impurities. As a result, the mechanical properties of the manufactured cast product may be reduced, and it is important to remove these impurities from the molten metal (e.g., deslag treatment or degassing treatment).

[0012] In the casting apparatus described in Patent Document 1, gases (for example, hydrogen gas) mixed in the molten metal are removed to the outside by a degassing mechanism, but the recovered gases are only removed and not reused. Furthermore, in order to stabilize product quality and protect the mold, the mold is usually preheated before casting begins. There are various methods for raising the temperature of the mold, but until now, heating using a gas burner has been the main method. However, there have been concerns about the environmental impact of combustion exhaust gases from using a gas burner.

[0013] On the other hand, as shown in Figure 1, the casting apparatus according to this disclosure (hereinafter also referred to as "this casting apparatus") uses a hydrogen combustor 2 that uses hydrogen gas to preheat the mold 1, thereby significantly reducing the amount of carbon dioxide emitted in the combustion exhaust gas and reducing the environmental impact. Furthermore, this casting apparatus is equipped with a hydrogen recovery unit 8 that has a degassing mechanism 5 for recovering hydrogen remaining in the mold 1 and molten metal, and the hydrogen recovered by the hydrogen recovery unit 8 can be reused for preheating the mold 1. In addition, in this casting apparatus, even if unburned hydrogen is generated and diffused into the mold when the mold is preheated by the hydrogen combustor 2, the degassing mechanism 5 can be used to recover the unburned hydrogen in the hydrogen recovery unit 8. This unburned hydrogen can then be reused for preheating the mold 1. Moreover, in this casting apparatus, by feeding back the quality data of the cast products actually manufactured into the casting process, it is possible to adjust the degassing treatment (amount of hydrogen recovered) and the mold preheating time, etc., thereby enabling the production of cast products that are more economical, time-efficient, and of higher quality. Thus, cast products manufactured using this casting apparatus are superior in terms of economy, environmental friendliness, and quality.

[0014] Specific embodiments applying this disclosure will be described in detail below with reference to the drawings. However, this disclosure is not limited to the following embodiments. Also, for clarity, the following description and drawings have been simplified as appropriate. Figure 1 is a schematic diagram illustrating an example of a casting apparatus according to this embodiment. Figure 2 is a flowchart illustrating an example of a casting method according to this embodiment.

[0015] As shown in Figure 1, the casting apparatus 10 according to this disclosure comprises a mold 1, a hydrogen combustor 2 capable of raising the temperature of the mold 1, and a hydrogen recoverer 8 capable of recovering hydrogen contained in the casting apparatus 10. The casting apparatus may also be equipped with a hydrogen supplyer 7 for supplying hydrogen to the hydrogen combustor 2, a degassing mechanism 5 for recovering hydrogen contained in the casting apparatus 10, a sleeve pin 6 for pushing molten metal into the mold, etc. Furthermore, the casting apparatus may be appropriately equipped with various components of conventionally known casting apparatuses, such as a molten metal holding furnace for heating and holding the molten metal (not shown). In addition, the casting apparatus can supply the hydrogen recovered by the hydrogen recoverer 8 to the hydrogen combustor 2. Furthermore, the casting apparatus can recover unburned hydrogen when using the hydrogen combustor 2 using the hydrogen recoverer 8 with the degassing mechanism 5, etc. The main components constituting the casting apparatus will be described below, but other components will not be described as they can be similarly used with conventionally known components commonly used in the field of casting apparatuses.

[0016] The shape and material of mold 1 can be appropriately set according to the shape and material of the cast product to be manufactured, and are not particularly limited; small, medium, or large molds can all be used. For example, a large mold with a height of 2m or more can be used as mold 1.

[0017] The hydrogen combustor 2 can be used without particular restrictions as long as it is capable of raising the temperature (preheating) of the mold 1. In this casting apparatus, hydrogen is used to preheat the mold 1, thus reducing the environmental impact of combustion exhaust gas. Figure 1 shows a configuration in which the hydrogen combustor 2, which uses a hydrogen flame (hydrogen burner) using hydrogen gas supplied from a hydrogen supply 7 such as a hydrogen cylinder and a hydrogen recovery 8, is positioned both above and below the mold. The configuration and arrangement of the hydrogen combustor 2 can be set as appropriate and are not particularly limited. In this casting apparatus, in addition to the hydrogen gas supplied from the hydrogen supply 7, hydrogen gas recovered from inside the mold 1 (more specifically, from the mold product section 3 and mold sleeve section 4), molten metal (not shown), and the molten metal holding furnace can be supplied to the hydrogen combustor 2 and reused as hydrogen gas for mold preheating. The hydrogen gas recovered from inside the mold 1 may be unburned hydrogen when using the hydrogen combustor 2, or it may be hydrogen gas that may cause casting defects contained in the molten metal in the molten metal holding furnace or mold. Thus, this casting apparatus provides a system that allows hydrogen recovered through the degassing treatment of molten metal to be reused for mold preheating. Furthermore, from the standpoint of maintaining the quality of the cast products, hydrogen can be added to the molten metal from the hydrogen supply unit 7 in some cases, and the amount of hydrogen added can be controlled based on the quality data of the cast products described later. Therefore, this casting apparatus can reduce safety risks associated with holding hydrogen cylinders for hydrogen supply and recovery for extended periods, and also reduces installation constraints in locations requiring ventilation.

[0018] The hydrogen recovery unit 8 may be equipped with a degassing mechanism 5 capable of recovering 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 combustor 2.

[0019] The degassing mechanism is not particularly limited as long as it can remove (and recover) residual (unburned) hydrogen in the mold 1, more specifically in the mold product section 3 and the mold sleeve section 4, and can degas (and recover) gas (hydrogen) in the molten metal (for example, in a molten metal holding furnace). In FIG. 1, a pressure reducing valve is shown as the degassing mechanism 5. This casting apparatus can have a configuration that detects unburned hydrogen remaining in the mold product portion 3 and the mold sleeve portion 4, and controls the pressure reducing time and pressure of the pressure reducing device in the mold. Specifically, for example, after preheating the mold 1 with a hydrogen burner 2 using a hydrogen flame, when unburned hydrogen remains in the mold sleeve portion 4 (pouring sleeve), hydrogen can be removed and recovered using the pressure reducing valve which is the degassing mechanism 5. Furthermore, this casting apparatus can also have an air blow as the degassing mechanism, and hydrogen gas that cannot be removed by the air blow can also be efficiently removed and recovered. Thus, this casting apparatus can recover unburned hydrogen when using the hydrogen burner 2 by means of the hydrogen recovery device 8, and furthermore, the unburned hydrogen can be reused for mold preheating, realizing safe and efficient casting. This casting apparatus may be a low-pressure casting apparatus. As other degassing mechanisms, devices used for degassing treatment in molten metal, for example, devices that blow inert gases such as argon or nitrogen gas into the molten metal, or rotating devices for further promoting degassing treatment, etc. can all be included. Also, this casting apparatus may perform degassing treatment in the molten metal using centrifugal force. As devices for blowing inert gases, for example, various devices such as lances, porous plugs, and rotary degassing devices can be used. Thus, in this casting apparatus, hydrogen gas removed from the molten metal by degassing treatment of the molten metal and recovered by the hydrogen recovery device 8 can be reused for mold preheating, realizing economical, environmental, and efficient casting. Note that the gas recovered by degassing treatment of the molten metal may contain other gases such as oxygen gas and nitrogen gas in addition to hydrogen gas, but it is preferable that the main component is hydrogen. This casting apparatus may optionally have a device (component) that recovers (extracts) only hydrogen gas from the gas recovered from the degassing treatment.

[0020] Also, this casting apparatus can also have a mold management system that controls the hydrogen recovery amount in the hydrogen recovery device 8 and the preheating time according to the initial temperature of the mold 1 based on the quality data of the manufactured cast product.

[0021] The hydrogen recovery amount can include, as described above, that recovered by degassing treatment in the molten metal and that recovered from unburned hydrogen remaining in the mold. Therefore, this casting apparatus monitors (records) these hydrogen recovery amounts in real time and controls the optimum hydrogen recovery amount based on the quality data of the cast product, so that excess hydrogen can be reused for mold preheating and safe and efficient production can be achieved. Further, as described above, from the viewpoints of product quality stabilization and mold protection, mold preheating is important. Therefore, by recording the initial temperature of the mold and controlling the optimum preheating time based on the quality data of the cast product, economical and high-quality casting can be realized. A control device (control system) that controls the hydrogen recovery amount in the hydrogen recovery device 8 and the preheating time according to the initial temperature of the mold 1 based on the quality data of the cast product can apply a conventionally known system as long as it can achieve these, and is not particularly limited. As described above, this casting apparatus detects in real time the amount of unburned hydrogen remaining in the mold product part 3 and the mold sleeve part 4 and the amount of hydrogen recovered from the molten metal by degassing treatment. Then, based on that information, the treatment time (decompression time) and power (decompression pressure) of the degassing mechanism (for example, a decompression device, an inert gas injection device, etc.) in the mold and the molten metal holding furnace are feedback-controlled. For example, taking the recovery of unburned hydrogen in the mold as an example, if the mold is preheated by a hydrogen flame and unburned hydrogen remains in the pouring sleeve, the decompression valve is operated to remove and recover the hydrogen. Further, hydrogen that cannot be removed by air blowing is also efficiently removed and recovered by using the decompression valve. At that time, based on the quality data of the cast product, the recovery amount of these hydrogen is appropriately adjusted. And feedback control can be performed to reuse the recovered unburned hydrogen for mold preheating again. Similarly, feedback control can be performed for the degassing treatment in the molten metal.

[0022] The casting method according to the present disclosure (hereinafter also referred to as the present casting method) uses this casting apparatus and is a casting method in which hydrogen recovered from within the casting apparatus is burned and used for raising the temperature of the mold. An example of the present casting method will be described with reference to FIG. 2, but the present disclosure is not limited to this example. First, when casting, mold 1 is opened (Step 1: S1). Then, the hydrogen combustor 2 is switched ON to start preheating mold 1 (Step 5: S5). At this time, since the hydrogen combustor 2 is a combustion device that uses hydrogen gas, unburned hydrogen may be generated (Step 6: S6), and this unburned hydrogen may diffuse into mold 1 (Step 7: S7). In this case, the unburned hydrogen is recovered by the hydrogen recovery unit 8 (Step 3: S3). Then, when the preheating of mold 1 is complete, the hydrogen combustor 2 is switched OFF (Step 8: S8). Next, mold 1 is clamped (Step 9: S9), molten metal is supplied (pouring) into mold 1 (Step 4: S4), and casting begins (Step 10: S10). Here, the following treatment is also performed on the molten metal in parallel. Specifically, the molten metal is purified (Step 2: S2) to improve its quality. This purification treatment can be any method conventionally known in the field of casting, and may include deslag treatment and degassing treatment aimed at removing impurities such as gases and 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 as hydrogen gas for use in the hydrogen combustor 2. Next, the molten metal, whose quality has been improved by the purification treatment, is poured into the mold 1 (Step 4: S4) and casting is started (Step 10: S10). Then, the quality of the resulting cast product is checked (Step 11: S11). As mentioned above, if hydrogen gas is mixed into the molten metal, casting defects due to bubbles may occur on the surface. Therefore, by feeding back the quality data of the cast product and controlling the amount of hydrogen recovered in S3 and the preheating time (combustion amount and combustor operating time) according to the initial temperature of mold 1 in S5 to S8, efficient, economical, and high-quality casting becomes possible.

[0023] Thus, this casting apparatus and casting method allow for the reuse of hydrogen gas recovered within the casting apparatus, enabling efficient, economical, and high-quality casting.

[0024] This disclosure is not limited to the embodiments described above, and may be modified as appropriate without departing from its intent. [Explanation of Symbols]

[0025] 1. Mold 2. Hydrogen Combustor 3. Mold Products Department 4. Mold sleeve section 5. Degassing mechanism 6 sleeve pins 7. Hydrogen supply unit 8. Hydrogen recovery unit 10 Casting apparatus

Claims

1. mold and A hydrogen combustor capable of raising the temperature of the mold, A hydrogen recovery device capable of recovering hydrogen contained within a casting apparatus, Equipped with, A casting apparatus capable of supplying hydrogen recovered by the hydrogen recovery device to the hydrogen combustor.

2. The casting apparatus according to claim 1, wherein the hydrogen recovery device includes a degassing mechanism capable of recovering hydrogen remaining in the mold and molten metal.

3. The casting apparatus according to claim 1, wherein unburned hydrogen used when the hydrogen combustor is used can be recovered by the hydrogen recovery device.

4. The casting apparatus according to claim 1, which can control the amount of hydrogen recovered in the hydrogen recovery unit and the preheating time according to the initial temperature of the mold, based on quality data of the cast product.

5. A casting method using a casting apparatus according to any one of claims 1 to 4, A casting method comprising burning hydrogen recovered from the casting apparatus and using it to raise the temperature of the mold.

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