SU933239A1 - Automatic stopper for casting - Google Patents

Description

(54) AUTOMATIC STOP FOR MOLDING

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The invention relates to a foundry, namely, devices for controlling the discharge of molten metal from the casting bowls into the molds, in particular up to through-pass method furnaces.

An automatic stopper for casting is known, for holding the molten metal in a bowl and overheating it to the required temperature when casting in a continuous furnace, comprising a housing with a stepped drain channel, two refractory rings, a fusible diaphragm, a radiation-reflecting element installed above the fusible diaphragm and a refractory cap, mounted on the fusible diaphragm D3.

The disadvantage of this stopper is that it always works at the same temperature of the fusible diaphragm, which is equal to the temperature of its melting. This temperature can only be controlled by

changes in the material of the fusible diaphragm and, accordingly, changes in its melting temperature. This requires the creation of a whole series of alloys with exactly known melting points. In production, it is often necessary to change the temperature at which the locking device operates, depending on the casting conditions, in order to obtain the maximum yield suitable for captives, looseness, macrostructure, etc.

The purpose of the invention is to simplify the adjustment of the response temperature of the stopper.

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Claims (2)

The chain is achieved by having an automatic stopper for casting, including a chassis with a step channel, a refractory ring and a plug installed in the channel of the stop ring, a groove is made on the side surface of the plug, and the stopper is provided with a rod that passes through the slot in the plug and is installed with the ends in the housing, the linear expansion coefficient of the rod material being greater than the material of the housing, and its melting point is higher than the pouring temperature. In order to obtain a larger amount of bending of the rod when heated, the rod can be made of bimetal. In order to prevent jamming of the NIN stub by the rod, it is also passed through holes made in the refractory ring. Due to the linear expansion of the metal rod, compared to the expansion of the ceramic stator housing and the plug, this rod increases the bend at the point of the plug circumference and, when it reaches the set temperature, completely releases it, resulting in a stop. The response temperature is controlled by varying the length of this rod. FIG. I shows the proposed stopper, a longitudinal section; FIG. 2 shows a section in FIG. 1, in FIG. 3 refractory ring, top view. In runner bowl 1 there is a drain channel 2. A refractory body 3 of a stopper is installed at the bottom of the bowl 1, which has a stepped drainage channel — cavities 4-7 — and two diametrically located several inches 1 and 1 of recesses 8 and 9 on its upper end on the side of the cavity 4. Size between opposite ends of the recesses 8 and 9 is strictly fixed. The diameter of the drain channel of cavity 4 is smaller than the diameter of the charge 10 set on the stopper. A refractory ring 1I is installed at the bottom of the cavity, having through holes 12 and 13. In the recess 8 and 9 and openings 12 and 13, a rod 14 is secured from contact with the metal with a thin multi-section shell 15. This clamp keeps the refractory ring in the channel refractory cap 16 with a groove 17. Depending on the length of the rod 14, it embraces, the cap 16 is weaker or denser. The stopper works as follows. In the process of passing the mold with the metal through the zones of heating and melting of the entrance, the furnace forms the heating of the mold from external heat sources and the metal pacnnaBjteHne in the bowl. . Under the action of heating, thermal expansion occurs both on the stopper shell and rod1 (made, for example, when smelting high-temperature nickel alloys with the required pouring temperature of 1450s-1500 ° C from titanium or molybdenum wires with higher melting points). Since the linear expansion coefficient of metals is greater than that of ceramics, the elongation of this rod will be ahead of the expansion of the stopper body. Resting against the ends of the recesses 8 and 9, it compensates for this difference in reinforcement by increasing the bend at the girth of the head 16. When the predetermined temperature is reached, the rod comes out of the groove 17 in the plug, and it is no longer held. , under the action of the hydrostatic pressure of the metal passes through the drain hole of the refractory ring, the cavity 6 of the stopper housing and is retained in the slit (Hole 7 of the stopper housing cavity. Metal through the empty drain channel of the refractory ring and the cavity 6 and 7 of the stopper fills the mold. In the process of heating, the multi-section refractory shell of the rod prevents its dissolution in the molten metal without interfering with its deformation (the metal does not touch the rod at the junction of the sections of the refractory shell due to surface tension) and 13 in the refractory ring 11 prevents the plug from sticking with the rod. Direct contact of the rod with the molten metal ensures maximum consistency between the metal temperature and the firing temperature no stopper. After the metal is drained into the mold, the work of the stopper ends. The proposed stopper allows adjustment of the temperature of operation of the stopper by adjusting the length of the rod, which is carried out simply and with high accuracy. Claim 1. Automatic stopper in the molding, including the housing with steps