RU2341351C2 - Fissural gating - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: system contains riser, level gate channel, slit gate and feeder-skimming chamber, connected to gate pipe and slit gate. At circumference of feeder-skimming chamber before inlet into slit gate perpendicularly or angularly to it is mounted metal plate with pass forming above the bottom of feeder-skimming chamber and vertical play between metal plate and inlet into slit gate. Passage area is not less than area of feeder at inlet, and cross section of clearance is not less than slit gate area at outlet. Thickness of metal plate is chosen based on condition of keeping its integrity to the moment of filling feeder by metal.

EFFECT: improving of bulky castings at the expense of discard reduction by slag and sand impurities.

2 dwg, 1 ex

Description

The invention relates to the field of foundry, in particular to the casting of steel parts in single sand-clay forms. It can be used in various fields of technology in the manufacture of large-sized thin-walled steel castings, for example, cast bearing parts of freight cars.

Known slot gate system containing a riser, a horizontal gate channel and slot feeder (SU 1210957, B22C 9/08, 02/15/1986). However, it is not effective enough to prevent slag and sand inclusions from entering the casting mold, which is essential when casting large-sized thin-walled steel parts.

The objective of the invention is to improve the quality of large-sized steel castings and reduce scrap by slag and sand inclusions.

The problem is achieved in that the gating system containing the riser, the horizontal gating channel and the slot feeder is equipped with a slag trap profit connected to the gating channel and the slot feeder, while at the periphery of the profit-slag trap before entering the slot feeder perpendicularly or at an angle to it a metal plate is installed that overlaps the entrance to the slot feeder with the formation of a passage above the base of the slag trap located below the level of the slot feeder and having an area not less than the area of the slot feeder at the entrance, and the vertical gap between the metal plate and the entrance to the slot feeder, having a cross-sectional area not less than the area of the slot feeder at the exit, while the metal plate has a thickness selected from the condition of maintaining its integrity by the time the profit is filled with metal.

Distinctive features of the claimed technical solution are:

- the presence of a slag trap connected to the gating channel and the slot feeder;

- installation of a metal plate on the periphery of the slag feeder before entering the slot feeder perpendicularly or at an angle to it, overlapping the entrance to the slot feeder with the formation of a passage above the base of the slag feeder located below the level of the slot feeder and having an area of at least the area of the slot feeder at the entrance ;

- the presence of a vertical gap between the metal plate and the entrance to the slotted feeder having a cross-sectional area not less than the area of the feeder at the outlet;

- the thickness of the metal plate, selected from the condition of maintaining its integrity by the time the profit is filled with metal.

The significance of the distinguishing features is confirmed by the following.

Lateral profit-slag trap in a closed gating system removes sand and slag inclusions as a result of surfacing above the upper level of the slot feeder, provided throughout the entire period of filling the mold with liquid metal.

The installation of a metal plate on the periphery of the side profit-slag trap before entering the slotted feeder eliminates the direct passage of molten metal to remove non-metallic inclusions from it; in the case of installing a metal plate at an angle to the entrance to the slotted feeder, centrifugal rotation in the slag trap and an increase in the intensity of the ascent of slag and sand inclusions are ensured.

The presence of a passage under the metal plate below the level of the slot feeder prevents sand and slag inclusions from passing into the latter and increases the efficiency of the slag trap, while its area should be not less than the entrance area of the slot feeder, which ensures the gate system is closed and the melt passes into the mold under flooded level. "

The presence of a vertical gap between the metal plate and the entrance to the slot feeder, having a cross-sectional area not less than the area of the feeder at the outlet, is necessary for heating the plate with melt and to exclude clogging of the entrance to the slot feeder, especially when pouring the most recent molds with low metal temperature. For the same purpose, the thickness of the metal plate is selected from the condition of maintaining its integrity by the time the profit is filled with metal.

In order to improve the efficiency of removal of non-metallic inclusions from the melt, the metal plate must maintain its integrity for at least the duration of filling the profit-slag trap.

Concrete example

Figure 1 shows a horizontal section of a slotted gating system for a single sand-clay mold for casting a side frame of a freight wagon trolley. It contains a horizontal sprue channel 1, a side slag trap profit 2, a metal plate 3 mounted on the periphery of the slag trap with a vertical gap 4 of 10 mm wide separating the metal plate from the entrance to the vertical slot feeder 5, through which metal is fed into the mold cavity 6.

Figure 2 shows a vertical section along A-A of a slag trap with a view of the entrance to the slotted feeder 5, having an outlet height of 70 mm and a width of 9 mm, in front of which there is a metal plate 3 with a thickness of 3 mm with dimensions in the plan of 80 × 100 mm, overlapping the vertical gap 4 with dimensions in the plan of 70 × 70 mm, the lower edge of which is placed under the mold connector to a depth of 15 mm with the formation of a passage above the bottom of the profit in the vertical gap located behind the metal plate. The cross-sectional area of the vertical gap is 700 mm ² , which exceeds the area of the slotted feeder at the outlet, equal to 630 mm.

When casting side frames made of 20 GL steel using the declared gating system, castings rejects on sand and slag inclusions decreased by more than 1.5 times.

Claims (1)

A slotted gating system comprising a riser, a horizontal gating channel and a slot feeder, characterized in that it is provided with a slag trap profit connected to the gating channel and a slot feeder, while at the periphery of the slag trap before entering the slot feeder perpendicularly or at an angle to it a metal plate is installed that blocks the entrance to the slot feeder with the formation of a passage above the base of the slag trap located below the level of the slot feeder and having an area of at least oschadi slit feeder inlet, and a vertical gap between the metal plate and the entrance to the feeder slit having the cross-sectional area not less than an area of the gap at the outlet of the feeder, wherein the metal plate has a thickness selected from the conservation of its integrity at time of filling profit metal.

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