JPS591049A - Method and device for molding casting mold - Google Patents

Abstract

PURPOSE:To reduce considerably stages for molding and to minimize the required amt. of the curing gas to be used, by sucking and packing molding sand added with a binder curable by gas and the curing gas into a mold simultaneously through suction effect. CONSTITUTION:A split pattern box 1 is moved upward together with a table to communicate a hole 10 for discharging molding sand of a hopper 9 with a supply hole 11 for molding sand. Stop valves 4, 13, 19 are opened, and the spaces in the pattern parts 8, 8A of the box 1 is quickly evacuated to a vacuum state through a vacuum receiver tank 5 to suck the molding sand 17 in the hopper 9 and to pack the same in the parts 8, 8A. A curing gas is also sucked by a differential pressure from a tank 14 for generating the curing gas through a conduit 12 so as to be mixed with the sand 17 under moving in the hole 10. Then, the sand 17 in the spaces in the parts 8, 8A is cured to all corners in a short time, and a casting mold is molded. When the curing gas is sucked thoroughly, the valves 13, 19 are closed, a stop valve 15 is opened, and the outside air is drawn through the hopper 9 and a branch pipe 16 to purge the curing gas.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for molding molds using molding sand to which a gas-curable binder is added.

Conventionally, when molding molds using foundry sand that has been added with a gas-curing binder, the foundry sand is blown into the mold together with compressed air, and then a hardening gas is aerated through the foundry sand in the mold. It is cured and molds are made. On the other hand, the facilitation gas is blown at high pressure in an amount greater than the required amount so that it is distributed throughout the entire foundry sand in the mold. For this reason, there was a drawback that the amount of curing gas consumed was large and it took a long time to form the mold.

The present invention has been made with the object of eliminating the above-mentioned drawbacks. Detailed explanation will be given below with reference to examples. In FIG. 1, (1) is a split model box, and the split model box (
The model 1) is made up of two models (2) (2A) that are arranged so as to be movable up and down via a table (not shown). The double horizontal type (2) (2A'Q, is the conduit (3) and the on-off valve (4)
) is provided with a hollow chamber (6) (6A) which communicates with the vacuum register 7 (tank (5)), and the hollow chamber (6)
(6A) connects the model part (8) through the ventilation hole (7) (7A).
(8A), respectively.

Furthermore, above the split model box (1), a funnel-shaped hopper (9) with an open upper end connects the bottom end of the molding sand discharge hole (lO) to the molding sand supply port (1) of the split model box (1). 11).

A hardening gas generation tank (14) is communicated with the foundry sand discharge hole (lO) via a gas conduit (12) and an on-off valve (13).
) and the foundry sand discharge hole (10) are communicated with a branch pipe (16) communicating with the atmosphere via an on-off valve (15).

In the figure, (17) is foundry sand added with a gas-curing binder, (18) is a conduit for introducing outside air or compressed air into the hardening gas generation tank (14), and an on-off valve (19)
to the atmosphere or to a source of compressed air.

With this structure, the split model box (1) is raised together with a table (not shown), and the molding sand discharge hole (10) and molding sand supply port (11) of the hopper (9) are opened as shown in Figure 1. Connect to. Next, the on-off valve (4) (13) (19
) and open the model part (8) of the split model box (1) (8A)
The space is rapidly evacuated and the foundry sand (
17) is suctioned by the differential pressure between the hopper (9) and the space of the model part (8) (8A) and filled into the model part (8) (8A).

At this time, the curing gas is also generated by the curing gas generation tank due to the differential pressure.

(14) and mixed with the foundry sand (17) moving through the foundry sand discharge hole (10). This allows the model part (8
) (8A) The molding sand (17) suction-filled into the space is hardened to every corner within a short time, and a mold is formed.

In this way, when a sufficient amount of hardening gas is sucked to harden the foundry sand (17), the on-off valves (13) (19) are closed, the on-off valve (15) is opened, and the hopper (9) and the branch pipe ( 16), outside air is taken in to purify the hardening gas. Thereafter, the on-off valves (4) and (15) are closed, and the split model box (1) is lowered, the molds are separated, and the formed mold is taken out. The above operation is repeated.

As is clear from the above description, in the present invention, molding sand added with a gas-hardening binder and hardening gas are simultaneously sucked and filled into the mold using suction action, so the molding process can be greatly shortened. Moreover, the amount of curing gas used can be kept to the necessary minimum, and other effects can be obtained.

As shown in Fig. 2 in addition to Fig. 1, an apparatus for carrying out the present invention includes a slide gate (20) provided at the upper part of the molding sand discharge hole (10) and a molding sand discharge hole (10). It may be possible to maintain a high degree of vacuum in the space that constitutes the space.

Further, the gas conduit (12) may be communicated with the inclined surface of the hopper (9) or the molding sand supply port (11) of the split model box (1) as shown in FIGS. 3 and 4.

Further, the gas conduit (12) may be connected to a liquid curing gas tank (14A) in which a liquid curing gas flows down into the conduit (12) as shown in FIG. Yet another sixth
As shown in the figure, a mold may be formed using a pattern plate (22) with a suction mechanism (21) and a flask (23). In this case, the molding sand discharge hole (1
0), and the hardening gas conduit (12) is communicated with each molding sand discharge hole (10).

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the present invention, and FIGS.
FIG. 6 is a longitudinal sectional front view showing another embodiment. (9): Hopper (10): Foundry sand discharge hole
. (12): Gas pipe (14): Cured gas generation tank Patent applicant: Shinto Kogyo Co., Ltd. 16 5 figures enemies 6 prisoners

Claims (1)

[Claims] 1) Molding sand to which a gas-curing binder has been added and a curing gas are introduced into the model space of the split model box or into the space formed by the pattern plate and the flask using a suction action. A mold making method characterized in that the foundry sand is hardened by suction filling while mixing the two. 2) The molding sand discharge hole of the hopper (9) with its upper end open (
10), a gas conduit (12) communicating with the curing gas generation tank (i-4) or the liquid curing gas tank (14A)
A mold making device characterized by communicating with each other.