JPH04294854A - Suction casting device - Google Patents

Abstract

PURPOSE:To restrain manufacturing cost of a stake to low. CONSTITUTION:In a surface plate 2 for laying a mold 4, the stoke 26 can be inserted and a tapered hole 2c downward from surface 2a of the surface plate 2 is arranged. On the other hand, upper end outer periphery of the stake 26 is covered with heat resistant sealing material 30, and the outer periphery of the heat resistant sealing material 30 is covered with a ring-like stoke fitting jig 40. The stoke fitting jig 40 is divided into two in circular direction, and gaps are arranged between the divided faces and further, this outer peripheral face provides the same inclination as tapered face of the tapered hole 2c. When the stoke fitting jig 40 engages with the tapered hole 2c in the surface plate 2 and receives force downward, while further deeply engaging, this outer diameter is reduced, and to the above heat resistant sealing material 30, the pressure in radius direction is loaded. By this method, even the stoke 26 is straight pipe shape, this is set on the surface plate 2 under securing sealing property.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a suction casting device that sucks and fills molten metal into a mold cavity and performs casting, and more specifically, the present invention relates to a suction casting device that performs casting by sucking molten metal into a mold cavity. This invention relates to a suction casting device.

0002

[Prior Art] In the suction casting method, a ventilated mold placed on a surface plate is surrounded by a chamber in an airtight state.
By reducing the pressure in this chamber, the molten metal in the hot water storage tank is drawn up into the cavity in the mold to perform casting. Here, a tubular stalk is used as a jig for communicating the molten metal in the hot water storage tank to the sprue of the mold. The lower end of the stalk is immersed in the molten metal in the hot water storage tank, and the upper end is connected to the sprue of the mold through an opening in the surface plate. As mentioned above, in order to suck up the molten metal into the cavity in the mold, it is necessary to keep the inside of the chamber airtight. For this reason, there must be a good seal between the outer periphery of the stalk and the aperture in the surface plate.

A conventional technique that attempts to solve this problem is disclosed in Japanese Utility Model Application Publication No. 184661/1983. In this suction casting device, a sealing fitting with a funnel-shaped tapered surface attached to an opening in a surface plate is engaged from above with a stalk having a flange having an inclination equal to the tapered surface of the sealing fitting. . This maintains the seal between the surface plate and the stalk.

0004

[Problems to be Solved by the Invention] However, according to the conventional stalk mounting structure, in order to ensure good sealing performance, the stalk is provided with a flange having an inclination equal to the tapered surface of the seal fitting. There is a need. For this reason, processing is time-consuming and the production cost of the stalk increases. In addition, a material that can be processed for the flange, etc. must be selected. Here, the stalk is a one-time disposable item, especially in the case of suction casting of iron-based high melting point materials.
We want to keep production costs as low as possible. The technical problem of the present invention is to reduce the production cost of stalks and widen the range of stalk materials to choose from by making it possible to set even straight pipe-shaped stalks on a surface plate with good sealing. It is something.

[0005]

[Means for Solving the Problems] The above problems are solved by a suction casting device having the following structure. That is, there is a ventilated mold placed on a surface plate and surrounded by a chamber in an airtight manner, a hot water storage tank located below the surface plate for storing molten metal, and a mold at the bottom of the mold. The suction casting device according to the present invention is equipped with a sprue provided in the chamber and sucks molten metal from the sprue of the mold into the cavity by reducing the pressure in the chamber to fill the cavity. a straight pipe-shaped stalk leading to the sprue of the mold; a tapered hole formed in the surface plate for inserting the stalk and having a tapered surface that widens toward the upper surface of the surface plate; a heat-resistant sealing material that covers the heat-resistant sealing material; and a stalk mounting jig that has a ring shape that covers the outer periphery of the heat-resistant sealing material and is divided into a plurality of parts in the circumferential direction and a gap is provided between the divided surfaces. There is. The outer circumferential surface of the stalk attachment jig has an inclination equal to the tapered surface of the tapered hole, and engages with the tapered hole.

[0006]

[Operation] According to the present invention, when the stalk mounting jig receives a downward force while engaged with the tapered hole of the surface plate, its outer diameter decreases as it engages more deeply with the tapered hole, Apply radial pressure to the heat-resistant sealant. As a result, the outer periphery of the stalk is subjected to radial pressure from the heat-resistant sealant. That is, the stalk is fixed to a stalk mounting jig with its upper end outer periphery tightened by a heat-resistant sealing material, and is set on a surface plate via this stalk mounting jig. Therefore, even if the stalk is in the shape of a straight pipe, it can be set on the surface plate in a well-sealed state.

[0007]

Embodiments Hereinafter, embodiments will be explained with reference to the drawings. FIG. 4 shows a cross-sectional view of the entire suction decompression device according to this embodiment. A mold 4 with air permeability is placed on the surface plate 2. This mold 4 has an upper mold 4a and a lower mold 4b.
A cavity 6 is defined inside the mold 4 by engaging the upper mold 4a and the lower mold 4b. The lower mold 4b is provided with a sprue portion 8 having an opening on the bottom surface 4c of the mold 4. Furthermore, this mold 4 is
The surrounding area is hermetically covered by a chamber 10. A pressure reduction port 12 is provided at the top of the chamber 10, and a vacuum pump (not shown) is connected to this pressure reduction port 12. A hot water storage tank 24 for storing molten metal 22 is installed below the surface plate 2. The molten metal 22 in this hot water storage tank 24 and the sprue part 8 of the lower die 4b of the mold 4
and communicate with each other through a straight pipe-shaped stalk 26.

With this structure, when the vacuum pump is driven to reduce the pressure inside the chamber 10, the gas inside the cavity 6 is discharged into the chamber 10 through the mold 4, and the inside of the cavity 6 becomes under negative pressure. As a result, the hot water tank 2
The molten metal 22 in 4 is guided into the cavity 6 through the stalk 26. In this way, the molten metal 22 filled in the cavity 6 solidifies and casting is performed.

FIG. 1 shows a plan view (A) and a cross-sectional view (B) of how the stalk 26 is set on the surface plate 2. The surface plate 2 is provided with an opening 2c into which the stalk 26 is inserted. This opening 2c is provided with a taper that widens toward the surface 2a of the surface plate 2 (hereinafter, this opening 2c will be referred to as a tapered hole 2c). on the other hand,
Heat-resistant wool 30 is wrapped around the upper end of the stalk 26 . The heat-resistant wool 30 has a truncated conical outer shape and is attached to the stalk 26 so that the bottom surface 30a of the cone is at the same level as the upper end surface 26a of the stalk 26. Furthermore, the outer peripheral surface 30 of the heat-resistant wool 30
c has an inclination approximately equal to the taper of the tapered hole 2c of the surface plate 2.

The edges of the outer peripheral surface 30c and the lower end surface 30b of the heat-resistant wool 30 are covered with a ring-shaped stalk attachment jig 40. This stalk attachment jig 40 is composed of two equally shaped jigs divided in the circumferential direction, and when these two jigs are fitted from the outside of the heat-resistant wool 30, A predetermined gap X is provided between the surfaces 40d. Further, the upper end surface 40a of the stalk attachment jig 40 is at the same level as the upper end surface 30a of the heat-resistant wool 30. Further, the outer peripheral surface 40c of the stalk attachment jig 40 is provided with an inclination equal to the taper of the tapered hole 2c of the surface plate 2, so that it can be engaged with the tapered hole 2c. If no downward force is applied to the stalk attachment jig 40 in a state where the stalk attachment jig 40 and the tapered hole 2c of the surface plate 2 are engaged, the upper end surface 40a of the stalk attachment jig 40 will be fixed. It protrudes from the surface 2a of the board 2 by a predetermined dimension Y. Furthermore, the center line of the stalk 26 and the center line of the tapered hole 2c coincide.

As shown in FIG. 1, once the stalk attachment jig 40 is set on the surface plate, the mold 4 is then placed on the upper end surface 40a of the stalk attachment jig 40. This situation is shown in FIGS. 2 and 3. Note that when placing the mold 4 on the stalk attachment jig 40, the center line of the sprue portion 8 and the center line of the stalk 26 are substantially aligned. In this way, the mold 4 is attached to the stalk attachment jig 40.
When placed on the upper end surface 40a, the gravity of the mold 4 is applied to the stalk attachment jig 40, and this gravity causes the stalk attachment jig 40 to be displaced downward, following the taper of the tapered hole 2c of the surface plate 2. to engage more deeply. In this process, the outer diameter of the stalk attachment jig 40 gradually decreases, and a radial pressing force is applied to the heat-resistant wool 30 from the periphery. That is, the outer periphery of the upper end of the stalk 26 is tightened with the heat-resistant wool 30. Then, the stalk attachment jig 40 is displaced downward, and the stalk attachment jig 40 is displaced downward.
The movement of the stalk attachment jig 40 stops when the heights of the upper end surface 40a and the surface 2a of the surface plate 2 are equal. Also, at this time, the dividing surface 4 of the stalk attachment jig 40
The gap X also becomes zero during 0d. Stoke 26 in this state
The set is completed.

As described above, according to this embodiment, the stalk 2
6 is connected to the stalk attachment jig 40 by having its outer peripheral surface subjected to a radial force by the heat-resistant wool 30. Further, the stalk attachment jig 40 is deeply engaged with the tapered hole 2c of the surface plate 2 while receiving the gravity of the mold 4. That is, the stalk 26 is set on the surface plate 2 with the outer periphery of the upper end tightened by the heat-resistant wool 30. This prevents the stalk 26 from falling and seals the stalk 26 and the surface plate 2. Therefore, the stalk 26 may have a simple straight pipe shape, and no special processing is required to attach it to the surface plate 2. This reduces the manufacturing cost of the stalk. Furthermore, since the processing of the stalk 26 is easy, the stalk 26
The selection range of materials is widened. Furthermore, the stalk 26 is tightened with a substantially uniform force from the outer circumferential direction by the heat-resistant wool 30, which is a sealing material, so that the sealing performance is constant. Therefore, the casting conditions are stabilized and the quality of the casting is stabilized. Furthermore, it is possible and economical to use the heat-resistant wool 30 multiple times.

In the case of this embodiment, an example was shown in which heat-resistant wool 30 was used as the sealing material; however, this heat-resistant wool 30
A heat-resistant powder material such as graphite, ceramics, casting sand, etc. may be mixed into the material. This heat-resistant powder material fills the gaps between the heat-resistant wool 30, thereby improving sealing performance.

[Effects of the Invention] According to the present invention, the stalk may have a simple straight pipe shape, and no special processing is required for attaching it to the surface plate, so the manufacturing cost of the stalk is reduced. Furthermore, since it is easy to process, there is a wide range of materials to choose from.

0012

[Brief explanation of drawings]

FIG. 1 shows a plan view (A) and a cross-sectional view (B) of how a stalk is set on a surface plate.

FIG. 2 is a sectional view (1) showing a state in which the mold is placed on the upper end surface of the stalk attachment jig.

FIG. 3 is a sectional view (2) showing a state in which the mold is placed on the upper end surface of the stalk attachment jig.

FIG. 4 is a cross-sectional view showing the entire suction decompression device according to the present embodiment.

[Explanation of symbols]

2 Surface plate 4 Mold 6 Cavity 10 Chamber 22 Molten metal 24 Hot water tank 26 Stoke 30 Heat-resistant wool 40　Stoke installation jig

Claims (1)

[Claims] 1. A ventilated mold placed on a surface plate and surrounded by a chamber in an airtight manner, a hot water storage tank located below the surface plate for storing molten metal, and the mold. and a sprue provided at the bottom of the chamber, and in which the molten metal is sucked from the sprue of the mold into the cavity and filled by reducing the pressure in the chamber, the molten metal in the storage tank is guided to the sprue of the mold. a straight pipe-shaped stalk; a tapered hole formed in the surface plate for inserting the stalk and having a tapered surface that spreads toward the upper surface of the surface plate; and a heat-resistant sealing material that covers the outer periphery of the upper end of the stalk. and a stalk attachment jig that is ring-shaped and that covers the outer periphery of the heat-resistant sealing material and is divided into a plurality of parts in the circumferential direction with gaps provided between the divided surfaces, A suction casting device characterized in that the outer circumferential surface has an inclination equal to the tapered surface of the tapered hole and engages with the tapered hole.