Release device

Abstract

To provide a mold release device capable of suppressing adhesion between an extrusion pin and an extrusion plate by a binder.SOLUTION: A mold release device according to the present embodiment is a mold release device which releases a molded product formed by filling a cavity of a mold with foamed sand from the mold. The mold release device includes: an extrusion pin protruding into the cavity of the mold to extrude the molded product; a first extrusion plate having a through-hole through which the extrusion pin is inserted and a clearance provided between the extrusion pin and the through-hole; and a second extrusion plate slidably holding a bottom of the extrusion pin between itself and the first extrusion plate. The clearance is blocked by a sealing member provided to closely adhere to the first extrusion plate while covering an outer circumference of the extrusion pin.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a mold release device.

Background Art

[0002] A cast molded product is released from a mold using an extrusion pin. Patent Document 1 discloses a mold release device provided with anti-sticking means for preventing sticking to the molded product at the tip of the extrusion pin in order to smoothly release the molded product from the mold.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, a clearance (gap) is provided between the mold and the extrusion pin in consideration of the thermal expansion of the mold. An extrusion plate is used to extrude the extrusion pin. The extrusion plate has a two-layer structure and sandwiches the bottom of the extrusion pin. A clearance is provided between the upper extrusion plate on the mold side of the two-layer extrusion plate and the extrusion pin, and the extrusion pin is configured to be slidable so that the extrusion pin does not tilt following the thermal expansion of the mold.

[0005] However, a binder for solidifying the molded product leaks into the clearance between the mold and the extrusion pin and remains in the clearance between the extrusion pin and the upper extrusion plate, so that the extrusion pin and the extrusion plate may stick together. When the extrusion pin and the extrusion plate stick together, there is a problem that the extrusion pin tilts due to the thermal expansion of the mold, and the molded product is deformed by performing the extrusion operation at a position deviated from the designed position.

[0006] The present invention has been made to solve such problems, and an object thereof is to provide a mold release device capable of suppressing the adhesion between the extrusion pin and the extrusion plate by a binder.

Means for Solving the Problems

[0007] A mold release device according to an aspect of the present invention is a mold release device for releasing a molded product cast by filling a cavity of a mold with foamed sand from the mold, an extrusion pin that protrudes into the cavity of the mold and extrudes the molded product, a first extrusion plate having a through hole through which the extrusion pin is inserted, and a clearance being provided between the extrusion pin and the through hole, and a second extrusion plate that slidably clamps the bottom of the extrusion pin between the second extrusion plate and the first extrusion plate. A seal member is provided so as to cover the outer periphery of the extrusion pin and be in close contact with the first extrusion plate, and the clearance is blocked. It is a mold release device.

[0008] In a mold release device according to an aspect of the present invention, a seal member is provided so as to cover the outer periphery of the extrusion pin and be in close contact with the first extrusion plate, thereby blocking the clearance between the extrusion pin and the through hole. According to a mold release device according to an aspect of the present invention, it is possible to suppress the binder from remaining in the clearance between the extrusion pin and the through hole, and it is possible to suppress the adhesion between the extrusion pin and the extrusion plate due to the binder.

Effects of the Invention

[0009] According to the present invention, it is possible to provide a mold release device capable of suppressing the adhesion between the extrusion pin and the extrusion plate by a binder.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, the specific embodiment to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. Also, for clarity of explanation, the following description and drawings are simplified as appropriate. The right-handed xyz orthogonal coordinates shown in FIGS. 1 to 3 are for convenience in explaining the positional relationship of each component. Usually, the positive direction of the z-axis is vertically upward, and the xy plane is a horizontal plane. For example, the positive direction of the x-axis may be vertically upward and the yz plane may be a horizontal plane, or the positive direction of the y-axis may be vertically upward and the zx plane may be a horizontal plane.

[0012] <Comparative Example> First, the structure and operation of the mold release apparatus 100 according to the comparative example will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view of the mold release apparatus 100 according to the comparative example, and shows a state before and after extrusion of the mold release apparatus 100. The upper figure in FIG. 1 shows the state before extrusion of the molded article 1, and the lower figure in FIG. 1 shows the state after extrusion of the molded article 1. Also, FIG. 1 shows the mold release apparatus 100 in a state where adhesion between the extrusion pin 10 and the extrusion plate 20 by the binder has not occurred.

[0013] The mold release apparatus 100 is a mold release apparatus for releasing a molded article 1 cast by filling a cavity of a mold 2 with foamed sand from the mold 2. The foamed sand contains particulate aggregates, a binder for solidifying the particulate aggregates, a surfactant, etc., and these are kneaded and foamed.

[0014] The mold release apparatus 100 includes an extrusion pin 10 and an extrusion plate 20. The extrusion pin 10 includes a main body portion 11 and a bottom portion 12. The extrusion plate 20 includes a first extrusion plate 21 and a second extrusion plate 22.

[0015] The extrusion pin 10 is used to protrude into the cavity of the mold 2 to extrude the shaped product 1. The extrusion pin 10 includes a main body portion 11 and a bottom portion 12, and is made of a metal such as iron or steel, for example. The shapes of the main body portion 11 and the bottom portion 12 of the extrusion pin 10 are not particularly limited, and are, for example, cylindrical or prismatic. The bottom portion 12 of the extrusion pin 10 is slidably sandwiched between the first extrusion plate 21 and the second extrusion plate 22. Although two extrusion pins 10 are shown in FIG. 1, the number is not limited to this and can be any number.

[0016] In the casting of the shaped product 1, it is necessary to heat the mold 2 filled with expanded sand to about 250°C to 300°C. Since the mold 2 thermally expands due to heating, a clearance is provided between the mold 2 and the extrusion pin 10 in consideration of the thermal expansion of the mold 2.

[0017] The extrusion plate 20 is a plate-like member used to extrude the extrusion pin 10. The extrusion plate 20 is made of a metal such as iron or steel, for example. The extrusion plate 20 has a two-layer structure of a first extrusion plate 21 and a second extrusion plate 22. The extrusion plate 20 sandwiches the bottom portion 12 of the extrusion pin 10 between the first extrusion plate 21 and the second extrusion plate 22 to support the extrusion pin 10. The extrusion plate 20 is driven in the z-axis direction by a driving means (not shown) such as a cylinder device driven by air or hydraulic pressure.

[0018] The first extrusion plate 21 has a through hole 21a through which the extrusion pin 10 is inserted, and a clearance is provided between the extrusion pin 10 and the through hole 21a. The second extrusion plate 22 slidably sandwiches the bottom portion 12 of the extrusion pin 10 between the second extrusion plate 22 and the first extrusion plate 21. That is, the extrusion plate 20 slidably sandwiches the extrusion pin 10. Thereby, the extrusion pin 10 can slide on the xy plane within the range of the clearance between the through hole 21a. From the above, even if the extrusion pin 10 is extruded outward following the thermal expansion of the mold 2, the extrusion pin 10 can maintain verticality because the extrusion pin 10 is slidable.

[0019] Even if the extrusion pin 10 is pushed inward due to the thermal expansion of the mold 2, the extrusion pin 10 can maintain verticality because it is slidable. Hereinafter, for simplicity of explanation, the direction in which the extrusion pin 10 is pushed by the thermal expansion of the mold 2 will be described as the outer direction. In addition, since a clearance is also provided between the mold 2 and the extrusion pin 10, when the extrusion pin 10 is not pushed outward by the thermal expansion of the mold 2, the extrusion pin 10 does not slide and maintains verticality.

[0020] The mold release device 100 can release the shaped article 1 by raising the extrusion plate 20 in the positive z-axis direction and extruding the shaped article 1 from the mold 2 using the extrusion pin 10.

[0021] FIG. 2 is a cross-sectional view of the mold release device 100 according to the comparative example, showing the state of the mold release device 100 before and after extrusion. The upper diagram in FIG. 2 shows the state before extrusion of the shaped article 1, and the lower diagram in FIG. 2 shows the state after extrusion of the shaped article 1. FIG. 2 shows the mold release device 100 in a state where the extrusion pin 10 and the extrusion plate 20 are fixed by the binder 1a.

[0022] As described above, since a clearance is provided between the extrusion pin 10 and the mold 2, the binder 1a contained in the expandable sand may leak into the clearance between the mold 2 and the extrusion pin 10. At this time, since a clearance is also provided between the extrusion pin 10 and the through-hole 21a, the leaked binder 1a remains in the clearance between the extrusion pin 10 and the through-hole 21a along the extrusion pin 10. As a result, the extrusion pin 10 and the extrusion plate 20 are fixed. Note that the larger the amount of the binder 1a contained in the expandable sand and the greater the pressure during casting, the greater the amount of the binder 1a leaking from the expandable sand, and thus the fixing between the extrusion pin 10 and the extrusion plate 20 becomes more prominent.

[0023] In a state where the extrusion pin 10 and the extrusion plate 20 are fixed by the binder 1a, when the extrusion pin 10 is extruded outward by the mold 2 that has thermally expanded with heating, the extrusion pin 10 cannot slide on the xy plane, and as shown in the upper diagram of Fig. 2, the extrusion pin 10 is in a tilted state. When the extrusion plate 20 is driven in a state where the extrusion pin 10 is tilted, the extrusion operation will be performed at a position deviated from the designed position by the extrusion pin 10, and the shaped product 1 will be deformed as shown in the lower diagram of Fig. 2.

[0024] <First Embodiment> The configuration and operation of the mold release device 200 according to the first embodiment will be described with reference to Fig. 3. Fig. 3 is a cross-sectional view of the mold release device 200 according to the first embodiment, showing the states before and after extrusion of the mold release device 200. The upper diagram of Fig. 3 shows the state before extrusion of the shaped product 1, and the lower diagram of Fig. 3 shows the state after extrusion of the shaped product 1.

[0025] The mold release device 200 according to the first embodiment is a mold release device that releases the shaped product 1 cast by filling the cavity of the mold 2 with expandable sand from the mold 2. The mold release device 200 includes an extrusion pin 10, an extrusion plate 20, and a seal member 3. For the extrusion pin 10 and the extrusion plate 20, those similar to those described in the above comparative example can be used.

[0026] The seal member 3 is provided so as to cover the outer periphery of the extrusion pin 10 and be in close contact with the first extrusion plate 21. Specifically, the seal member 3 covers the outer periphery of the main body portion 11 of the extrusion pin 10. The clearance between the extrusion pin 10 and the through hole 21a of the first extrusion plate 21 is blocked by the seal member 3. The seal member 3 is, for example, a ring-shaped member having a hole portion into which the main body portion 11 of the extrusion pin 10 can be inserted at the central portion. The shape of the seal member 3 is not particularly limited, and can be, for example, cylindrical or prismatic.

[0027] As shown in FIG. 3, even if the binder 1a leaks out into the clearance between the extrusion pin 10 and the mold 2, by using the seal member 3, it is possible to suppress the binder 1a from remaining in the clearance between the extrusion pin 10 and the through hole 21a. That is, according to the mold release device 200 according to the first embodiment, by using the seal member 3, it is possible to suppress the binder 1a from sticking the extrusion pin 10 and the extrusion plate 20 together.

[0028] The seal member 3 is provided so as to cover the outer periphery of the extrusion pin 10 and be in close contact with the first extrusion plate 21, but is not adhered to the first extrusion plate 21 and is not fixed to the first extrusion plate 21. Therefore, even if the extrusion pin 10 is extruded outward due to the thermal expansion of the mold 2, the extrusion pin 10 can slide on the xy plane and maintain verticality. Thereby, the extrusion pin 10 can perform an extrusion operation in the vertical direction toward the design position. That is, according to the mold release device 200 according to the first embodiment, it is possible to suppress deformation of the shaped article 1 accompanying the mold release of the shaped article 1. Note that since the seal member 3 slides integrally with the extrusion pin 10, it may be fixed using an adhesive or the like between the seal member 3 and the main body portion 11 of the extrusion pin 10.

[0029] Since the mold 2 is heated and used, the seal member 3 preferably has heat resistance. Further, the seal member 3 is preferably an elastic member that can cover the outer periphery of the extrusion pin 10 and be in close contact with the first extrusion plate 21. As a member having heat resistance and elasticity, for example, a member containing silicone rubber can be used for the seal member 3.

[0030] As described above, the foamed sand used for the shaped article 1 contains particulate aggregate, a binder 1a for solidifying the particulate aggregate, a surfactant, etc., and is produced by kneading these. When the binder 1a contains an inorganic binder, it is not thermally decomposed even by heating the mold 2, so the adhesion between the extrusion pin 10 and the extrusion plate 20 becomes strong. In the mold release device 200 according to the first embodiment, since the seal member 3 is used to block the clearance between the extrusion pin 10 and the through-hole 21a, it is possible to suppress the binder 1a from remaining in the clearance between the extrusion pin 10 and the through-hole 21a. That is, the mold release device 200 according to the present embodiment can be suitably used even when the binder 1a contains an inorganic binder.

[0031] Further, when the inorganic binder particularly contains water glass, the adhesion between the extrusion pin 10 and the extrusion plate 20 becomes remarkable. In the mold release device 200 according to the first embodiment, since the seal member 3 can block the clearance between the extrusion pin 10 and the through-hole 21a, it can be suitably used regardless of the type of the binder 1a, even if the inorganic binder contains water glass.

[0032] Note that the present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the gist thereof.

Explanation of Reference Numerals

[0033] 1 Shaped article 1a Binder 2 Mold 3 Seal member 10 Extrusion pin 11 Main body portion 12 Bottom portion 20 Extrusion plate 21 First extrusion plate 21a Through-hole 22 Second extrusion plate 100 Mold release device 200 Mold release device

Claims

1. A mold release device for releasing a molded article cast by filling a cavity of a mold with foamed sand from the mold, comprising: a push-out pin protruding into the cavity of the mold and pushing out the molded article in the z-axis direction; a first push-out plate having a through-hole through which the push-out pin is inserted and provided with a clearance between the push-out pin and the through-hole; a second push-out plate that sandwiches the bottom of the push-out pin between the first push-out plate so as to be slidable on the xy plane within the range of the clearance; a seal member provided so as to cover the outer periphery of the push-out pin and be in close contact with the first push-out plate, closing the clearance; a mold release device.

2. The seal member contains silicone rubber, The mold release device according to Claim 1.

3. The foamed sand contains an inorganic binder, The mold release device according to Claim 1 or 2.

4. The inorganic binder contains water glass, The mold release device according to Claim 3.

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