JP2817436B2 - Suction casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction casting apparatus for sucking and filling a molten metal into a cavity of a mold to perform casting, and more particularly, to simplify a shape of a stalk for guiding the molten metal to a gate of the mold. The present invention relates to a suction casting device.

[0002]

2. Description of the Related Art In a suction casting method, a gas-permeable mold placed on a surface plate is air-tightly covered with a chamber.
By reducing the pressure in the chamber, the molten metal in the hot water storage tank is sucked 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 tank with the gate 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 gate of the mold through an opening in the surface plate. As described above, it is necessary to keep the inside of the chamber airtight in order to suck up the molten metal into the cavity in the mold. For this reason, the seal between the outer periphery of the Stoke and the opening of the platen must be good.

A prior art for solving this problem is disclosed in Japanese Utility Model Laid-Open No. 63-184661. In this suction casting device, a stalk having a flange having a slope equal to the taper surface of the seal fitting is engaged from above with a seal fitting having a funnel-shaped tapered surface attached to the opening of the surface plate. . Thereby, the sealing property between the surface plate and the stalk is maintained.

[0004]

However, according to the Stoke mounting structure according to the prior art, the Stoke is provided with a flange having an inclination equal to the taper surface of the seal fitting in order to ensure good sealing performance. There is a need. For this reason, processing is troublesome, and the production cost of Stoke is increased. In addition, a material that can be processed, such as a flange, must be selected. Here, Stoke is a single-use disposable, especially in the case of suction casting of an iron-based high melting point material.
We want to keep production costs as low as possible. The technical problem of the present invention is to reduce the manufacturing cost of the stalk and widen the selection range of the stalk material by enabling the stalk to be set on the surface plate in a good sealing state even if the stalk has a straight pipe shape. Things.

[0005]

The above-mentioned object is achieved by a suction casting apparatus having the following components. That is, in the state of being placed on the surface plate, the periphery of the air-permeable mold covered by a chamber in a gas-tight state, a hot water storage tank below the surface plate to store the molten metal, and the bottom of the mold Provided with a sprue provided, wherein the suction casting apparatus according to the present invention, in which the molten metal in the hot water storage tank is filled by sucking and filling the molten metal from the sprue of the mold into the cavity by reducing the pressure in the chamber. A straight pipe-shaped stalk to be guided to the gate of the mold, a tapered hole provided in the surface plate for inserting the stalk, and having a tapered surface extending in the upper surface direction of the surface plate, and an outer periphery of an upper end of the stalk. A heat-resistant sealing material to cover, and a Stoke mounting jig in a ring shape covering the outer periphery of the heat-resistant sealing material, which is divided into a plurality in the circumferential direction and a gap is provided between the divided surfaces. That. And the outer peripheral surface of the Stoke mounting jig has the same inclination as the tapered surface of the tapered hole, and engages with the tapered hole.

[0006]

According to the present invention, when the Stoke mounting jig receives a downward force in a state in which it is engaged with the tapered hole of the surface plate, the outer diameter of the jig is reduced while being further deeply engaged with the tapered hole, A radial pressure is applied to the heat-resistant sealing material. As a result, the outer periphery of the stalk receives a radial pressure from the heat-resistant sealing material. That is, the stalk is fixed to the stalk mounting jig in a state where the outer periphery of the upper end is fastened by the heat-resistant sealing material, and is set on the surface plate via the stalk mounting jig. Therefore, even if the stalk has a straight pipe shape, the stalk is set on the surface plate in a good sealing state.

[0007]

Embodiments will be described below with reference to the drawings.
FIG. 4 is a cross-sectional view illustrating the entire suction and pressure reducing device according to the present embodiment. On the surface plate 2, a mold 4 having air permeability is placed. This mold 4 has an upper mold 4a and a lower mold 4b.
When the upper mold 4a and the lower mold 4b are engaged with each other, a cavity 6 is defined inside the mold 4. The lower mold 4b is provided with a gate section 8 having an opening in the bottom surface 4c of the mold 4. Furthermore, this mold 4
The periphery is hermetically covered by a chamber 10. A decompression port 12 is provided in the upper part of the chamber 10, and a vacuum pump (not shown) is connected to the decompression port 12. A hot water storage tank 24 for storing the molten metal 22 is provided below the surface plate 2. The molten metal 22 in the hot water storage tank 24 and the gate section 8 of the lower mold 4b of the mold 4 communicate with each other through a straight tubular stalk 26.

With this structure, when the inside of the chamber 10 is depressurized by driving the vacuum pump, the gas in the cavity 6 is discharged into the chamber 10 through the mold 4 and the inside of the cavity 6 is in a negative pressure state. Thereby, hot water storage tank 2
The molten metal 22 in 4 is guided into the cavity 6 through the stalk 26. Thus, the molten metal 22 filled in the cavity 6 is solidified and casting is performed.

FIG. 1 is a plan view (A) and a sectional view (B) showing how the stalk 26 is set on the surface plate 2. The base 2 is provided with an opening 2c for inserting the stalk 26. The opening 2c is provided with a taper that extends toward the surface 2a of the surface plate 2 (hereinafter, the opening 2c is referred to as a tapered hole 2c). on the other hand,
Heat resistant wool 30 is wound around the outer periphery of 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 such that the bottom surface 30a of the cone is at the same level as the upper end surface 26a of the stalk 26. Further, the outer peripheral surface 30 of the heat-resistant wool 30
“c” has an inclination substantially equal to the taper of the tapered hole 2 c of the surface plate 2.

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

As shown in FIG. 1, when the Stoke mounting jig 40 is set on the surface plate, the mold 4 is then placed on the upper end surface 40a of the Stoke mounting jig 40. This situation is shown in FIGS. When the mold 4 is placed on the stoke mounting jig 40, the center line of the gate section 8 and the center line of the stalk 26 are substantially aligned. In this manner, the mold 4 is moved to the Stoke mounting jig 4.
When the stalk mounting jig 40 is placed on the top end surface 40a of the base plate 2, the gravitational force of the mold 4 is applied to the stalk mounting jig 40, and the stalk mounting jig 40 is displaced downward by the gravitational force. Follows and engages deeper. In this process, the outer diameter of the Stoke mounting 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 fastened by the heat-resistant wool 30. Then, the Stoke mounting jig 40 is displaced downward, and the Stoke mounting jig 4
The movement of the Stoke mounting jig 40 stops in a state where the height of the upper end surface 40a of the zero and the surface 2a of the surface plate 2 are equal. At this time, the gap X between the divided surfaces 40d of the Stoke mounting jig 40 is also zero. In this state, the setting of the stalk 26 is completed.

As described above, according to the present embodiment, Stoke 2
6 is connected to a Stoke mounting jig 40 by receiving a radial force on the outer peripheral surface thereof by the heat-resistant wool 30. Further, the Stoke mounting jig 40 is deeply engaged with the tapered hole 2 c of the surface plate 2 under the gravity of the mold 4. That is, the stalk 26 is set on the surface plate 2 in a state where the outer periphery of the upper end is fastened by the heat-resistant wool 30. This prevents the stalk 26 from dropping and seals the stalk 26 from the stool 26. Therefore, the stalk 26 may have a simple straight pipe shape, and no special processing for attaching to the surface plate 2 is required. For this reason, the manufacturing cost of Stoke is reduced. Furthermore, since the processing of Stoke 26 is easy, Stoke 26
The material selection range becomes wider. Further, the stalk 26 is tightened from the outer peripheral direction with a substantially uniform force by the heat-resistant wool 30 as a sealing material, so that the sealing performance is stabilized. For this reason, the casting conditions are stabilized, and the quality of the casting is stabilized. Further, the heat-resistant wool 30 can be used a plurality of times, which is economical.

In this embodiment, an example is shown in which heat-resistant wool 30 is used as a sealing material.
A heat-resistant powder material, for example, graphite, ceramics, molding sand, or the like may be mixed with the heat-resistant powder material. The heat-resistant powder material fills the gaps of the heat-resistant wool 30 to improve the sealing property.

According to the present invention, the stalk may have a simple straight pipe shape, and no special processing is required for mounting the stalk on the surface plate, so that the manufacturing cost of the stalk is reduced. Further, since the processing is simple, the selection range of the material is widened.

[0012]

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view (1) illustrating a state where a mold is placed on an upper end surface of a Stoke mounting jig.

FIG. 3 is a cross-sectional view (2) illustrating a state where the mold is placed on the upper end surface of the Stoke mounting jig.

FIG. 4 is a cross-sectional view illustrating the entire suction and pressure reducing device according to the present embodiment.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-70367 (JP, A) JP-A-61-9174 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 18/04

Claims (1)

(57) [Claims] 1. A gas-permeable mold whose periphery is air-tightly covered by a chamber when placed on a surface plate, a hot water storage tank below the surface plate for storing molten metal, and the mold A suction port provided at the bottom of the mold, and suctioning and filling the molten metal from the gate of the mold into the cavity by reducing the pressure in the chamber. A straight pipe-shaped stalk, a tapered hole provided in the surface plate for inserting the stalk, and having a tapered surface extending in an upper surface direction of the surface plate, and a heat-resistant sealing material covering an outer periphery of an upper end of the stalk. A stoke mounting jig having a ring shape that covers the outer periphery of the heat-resistant sealing material, the stoke mounting jig being divided into a plurality in the circumferential direction, and a gap being provided between the divided surfaces. A suction casting apparatus characterized in that the outer peripheral surface of the tool has an inclination equal to the tapered surface of the tapered hole and engages with the tapered hole.