KR100871359B1 - Apparatus for manufacturing casting mold - Google Patents

Abstract

A core molding apparatus enabling a casting method using molding sand to be executed is provided to cut down costs by suppressing the use of the molding sand in the manufacture of hollow cast articles. A molding apparatus of a hollow core for casting comprises a mold(2) comprised of at least two unit molds to form a cavity and a molding injection port by joining the unit molds with each other, a mold operating part(4) which fixes the mold, and causes the molds to be united with each other or separated from each other by a hydraulic or pneumatic cylinder, a molding sand supplying part(6) for supplying molding sand into the cavity of the mold, a heating part(8) installed on the mold operating part to heat the molding sand filled in the mold, and a turnover part(10) for rotating the mold such that the molding sand injection port selectively faces the ground.

Description

Apparatus for manufacturing casting mold

1 is a schematic cross-sectional view of a mold required for forming a manifold of a vehicle.

Figure 2 is a schematic perspective view of the core molding apparatus according to an embodiment of the present invention.

Figure 3 is a schematic front configuration diagram of the core molding apparatus according to an embodiment of the present invention, Figure 4 is a schematic side configuration diagram.

5 is a partially cutaway perspective view of the core manufactured by the core molding apparatus of the present invention.

6 to 7 are cross-sectional configuration diagrams illustrating the molding process of the core as a schematic cross-sectional view of a mold.

Explanation of symbols on the main parts of the drawings

2 (2a, b); Mold 4; Mold operation part

6; Casting sand supply section 8; Heating

10; Inversion 20; Pressurized metering unit

24; Outlet 26; Inverted motor

32; Fetish Society

M; Casting product (vehicle manifold)

The present invention relates to a molding apparatus for casting cores, and more particularly, to a molding apparatus for hollow cores that can reduce the amount of casting sand by partially recovering the casting sand during the process.

Casting is one of the traditional manufacturing methods that are widely used to make molded articles of complex metals and resins. Molding molds are required for casting, but casting sand is usually used to produce the molding molds. Depending on the shape of the molded product to be produced, only an outer mold may be required, and an inner mold (core or core) may be additionally required.

1 is a schematic cross-sectional view of a mold required for forming a manifold of a vehicle. The manifold M which is a molded article is simplified and shown. In casting a product having a cavity such as the manifold M, both the outer mold 100 and the inner mold 102 are required. When the cast product is a material having a low melting point such as aluminum, the outer mold 100 may be made of another metal having a high melting point. Therefore, the outer mold 100 can be used repeatedly. However, the inner mold 102 still needs to use a molding sand because it can be easily removed from the molding after completion.

Foundry sand, as is well known, contains certain binders to increase the bond between the grains of sand. As a binder, an organic curing agent that generates gas upon curing is used, which is evaluated as being harmful to humans and the environment, and thus requires a moderation of use.

Commonly used foundry sand is usually disposed of, which causes significant economic losses, including environmental issues.

In response to this problem, a "regeneration apparatus and regeneration method of foundry sand" of Korean Patent Publication No. 1998-080092 published by the Korean Patent Office has been devised. However, this has a problem that the method is difficult to implement and additionally requires a complicated device.

An object of the present invention for the above problems is to provide a core molding apparatus that can execute the casting method using the molding sand, which can reduce the cost by suppressing the use of the molding sand in the manufacture of the casting having a hollow. . In addition, an object of the present invention is to provide a casting method capable of obtaining a desired effect without burdening a large manpower and cost, and a hollow core molding apparatus that can utilize the method.

The above object is to hollow out the core by removing the uncured inner casting sand from the mold while only the casting sand of a certain thickness is cured from the surface which is in thermal contact with the mold during the curing of the molding sand. It is achieved by a core molding apparatus for implementation.

More specifically, a mold composed of two or more unit molds and forming a cavity and a molding injection hole (I) when molding; A mold operating part for enabling the mold or release of the mold by a hydraulic or pneumatic cylinder; A molding sand supply unit for supplying a molding sand into the hollow inside of the mold; A heating unit installed in the mold or the mold operation unit to apply heat to the molding sand filled in the mold; It is achieved by the casting core forming apparatus characterized in that it comprises an inverting portion for rotating the mold so that the injection molding inlet can be selectively directed to the ground.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 2 is a schematic perspective view of the core molding apparatus according to an embodiment of the present invention. Figure 3 is a schematic front configuration diagram of the core molding apparatus according to an embodiment of the present invention, Figure 4 is a schematic side configuration diagram. 5 is a partially cutaway perspective view of the core manufactured by the core molding apparatus of the present invention.

The present invention discloses a step for removing an uncured inner molding sand from the mold in a state where only a molding sand of a certain thickness is cured from the surface which is in thermal contact with the mold during the curing of the molding sand, and an apparatus for performing the same. .

The core molding apparatus according to the present invention essentially includes a mold 2, a mold operating part 4, a foundry sand supply part 6, a heating part 8, and an inverting part 10. The mold 2 is composed of two or more unit molds 2a and b and is fixedly installed in the mold operation part 4. The mold operating portion 4 includes a jig 14 and a hydraulic cylinder 12 (or pneumatic cylinder, hereinafter referred to as a cylinder), whereby the mold can be molded or released. Two unit molds 2a and b are provided, which are installed to be transportable in the transverse direction. In the mold, a cavity, which is a space in which a molding sand is inevitably filled, is provided, and a molding sand inlet I (see FIG. 6) is provided in an upward direction of the mold.

Above the mold 2, a casting sand supply part 6 for supplying a molding sand to the hollow of the mold is provided. The casting sand supply unit 6 may include a hopper 18, a pressurized meter discharge unit 20, and a discharge port 24. The ejection opening 24 of the foundry sand supply unit is movably installed in the left and right directions on the front view of FIG. 3 and is selectively located at the foundry injection hole.

Foundry sand (S) is an aggregate of sand grains coated with an organic hardener. The content regarding the foundry sand S is no different from the conventional one.

A heating part 8 for applying heat to the molding sand filled in the hollow in the mold is provided in the jig 14 for fixing the mold. The heating unit 8 includes a heat transfer coil, which heats the mold at the curing temperature of the organic curing agent.

The above is not much different from the prior art. The biggest feature of the present invention resides in the inversion section 10 described below. The inverting portion 10 is a device that rotates the entire mold 2 so that the injection molding inlet can be selectively directed to the ground. When the mold 2 is turned upside down during the curing process, that is, when the mold 2 is inverted, the molding injection hole faces downward as shown in FIG. 7. Then, the part of the foundry sand that was not cured and maintained the particle state remains in a state that can be discharged to the outside of the mold while naturally falling through the foundry injection hole (I).

The reversal timing may be determined immediately on site by the operator's experience or may be predetermined and entered into the system based on a large number of experiences. However, the time taken to harden only the surface layer of foundry sand is extremely short. Therefore, reversal starts 2 ~ 3 seconds after injection of molding and foundry sand. According to this, it can be seen that the time required for molding the molding sand can be shortened and the productivity per unit time can be extremely improved.

The inverting unit 10 allows the mold and the mold operation unit to rotate in both directions in a range of 180 °. The reversal unit 10 includes a reversing motor 26, which is a reduction gear, a roller 27 supporting the mold operation unit such that the mold operation unit can be rotated about a rotation center axis.

Damping means may be applied to prevent impact due to rotation within a certain range of the heavy rotating body including the mold (2) and the mold operating portion (4). In addition, limit means 22 for limiting the rotation angle may be further provided.

A compressed air inlet 28 (only a part of which is shown) is provided as an auxiliary means for easily or automatically discharging the molding sand while the mold 2 is inverted. The compressed air injection unit includes an injection nozzle, an air pipe 28 and an air compressor installed at a specific part of the mold to communicate with the hollow. Compressed air is generated by an air compressor installed separately and injected into the mold, in particular, the molding sand through the injection nozzle. The shape of the article determines the compressed air input position for forcibly ejecting the foundry sand.

Compressed air is injected at the same time as the inversion of the mold 2 or at the same time as the inversion is completed. Compressed air input is an optional element for efficient removal of foundry sand. This is because the worker can remove the foundry sand to some extent using a simple tool, and the foundry sand can be removed to some extent by the physical impact during the reversal.

In addition to or in place of the compressed air injection unit, a vibration unit (not shown) may be further provided. This vibration part is for discharging the casting sand more easily. The vibration period, the amplitude or the vibration direction by the vibration unit may be set in various ways within the technical common sense. However, the range of vibration should be limited to the extent that the machined portion is not broken by the vibration.

According to an embodiment of the present invention, the foundry social part 32 may be further provided. The casting social water part 32 is for recovering the casting sand which falls naturally (or forcedly falls by the vibration part), and re-injects it into the casting sand supply part 6 manually or automatically.

Therefore, the casting and drinking water part 32 may be configured with various specifications from a simple configuration by the bucket 34 alone to a configuration further including a lifting conveyor 37 extending up to the top of the return screw 36 and the hopper 18 of the supply part. Can be.

2 to 4 schematically illustrate only essential components of the molding apparatus, there may be additional elements not shown. For example, a control panel that can control the start of the device, a duct for exhausting the generated harmful gas to the outside of the workplace may be included.

5 is a schematic perspective view of a hollow core according to an embodiment of the present invention. As the cast product, an intake or exhaust manifold M of the vehicle is illustrated. Since this is only an example, the molding apparatus of the present invention can be utilized for casting various articles existing in the industry by replacing only a mold.

When the process of forming the core by the molding apparatus of the above configuration is expressed as a schematic cross-sectional view of the mold as shown in Figs. FIG. 6 shows a state in which a molding sand is filled in the mold in a steady state and only the surface layer M1 (bounded by a dotted line) in contact with the mold is cured. Compressed air is introduced into the mold through the air inlet hole H provided at one side.

Fig. 7 shows a state in which the molding sand M2 (see Fig. 6) in the center is discharged as the mold is inverted.

Foundry sands discolor from yellow to dark brown during hardening. When the temperature of the mold 2 reaches the curing temperature of the organic curing agent, the foundry sand gradually begins to plastically harden, and the point where the curing starts will be the surface in contact with the mold 2. From the surface contact surface with the mold of the foundry sand, only a predetermined thickness T (for example, 1.0 to 3.0 mm) is removed and the unworked foundry sand 4b is removed, thereby completing the hollow core. The finished core is used for subsequent processing for casting and then discarded.

According to the above configuration, there is provided a heavy magnetic molding apparatus that can reduce the weight of the core and the harmful gas generated during the curing process of foundry sand discarded after use. Since the foundry sand removed during the hardening process is not denatured to a sufficient extent for recycling, a heavy magnetic molding apparatus is provided that can further contribute to the reduction of the foundry sand. In addition, by removing a significant amount of the foundry sand in the curing step it is possible to greatly shorten the time to complete the curing is provided a core molding apparatus that can maximize the production of the core.

Claims (3)

delete A mold (2) composed of two or more unit molds and forming a cavity and a molding injection hole (I) when molding; A mold operating part 4 which fixes the mold 2 and enables molding or release of the mold by a hydraulic or pneumatic cylinder; A casting sand supply part 6 for supplying a molding sand into the hollow inside of the mold 2; A heating part (6) installed in the mold operation part (4) to apply heat to the molding sand filled in the mold (2); An inverting part 10 for rotating the mold 2 so that the molding sand injection hole I can selectively face the ground; Casting medium injection device characterized in that it comprises a compressed air injection unit for injecting compressed air to the injection molding inlet (I) for easy discharge of the molding sand. The method of claim 2, wherein the bucket (34) for containing the molding sand discharged from the mold (2); Casting main body molding apparatus further comprises a casting social water part (32) comprising a return screw (36) for transferring the foundry sand contained in the bucket (34) to the foundry sand supply (6).

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