SU1215858A1 - Injection mould - Google Patents

Description

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The invention relates to a foundry industry, in particular to injection molding.

The purpose of the invention is to reduce backpressure of gases and improve the ventilation conditions of the mold.

FIG. depicts a mold in the oment filling the working cavity with etalom, cut; in fig. 2 - the same, at the time of the completion of filling the mold with metal.

The mold contains movable and fixed molds 1 and 2 with a slave cavity 3, in which the casting is formed, and an industrial cavity 4, filled in the mobile mold 1. The lower part of the industrial part 4 is connected by the ventilation channel 5 with the working cavity 3, and the upper part - the atmosphere. The mold also contains a valve 6 installed in the cavity of the jointer 4 with the possibility of its movement in the direction of the metal flow. In the fixed mold 2, there is a vent 7 that connects the volume of the industrial cavity under the valve with its volume above the valve.

A stop 8 is mounted on the movable half-form 1, which limits the movement of the valve 6 upwards, and on the valve 6 a pin 9 passing through the hole in the stop 8.

The mold works as follows.

- When pressing the metal into the mold, the gases are in the working

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cavities 3 are forced out through channel 5 and the ventilation channel 7, bypassing valve 6, to the atmosphere (Fig. 1) or to the evacuating vacuum system. AT

At the end of the mold, the metal 10 enters through the channel 5 into the lower part of the industrial cavity 4. The metal stream 10 lifts up the valve 6 (Fig. 2), which closes the ventilation channel 7. At the same time, the gases are released into the atmosphere and the metal is prevented from ejection Press forms. - After mold opening valve 6 and vent. Channel 7 is available for inspection and cleaning.

Dp of efficient operation of the mold is recommended to observe two conditions: the cross-sectional area of the channel 5 f should not be greater than 42% of the cross-sectional area of the feeder f ((-), and the numerical value of the resistance to movement of the valve 6 PC should be.

-compose 32.2 of the channel cross-sectional area of 5 Hz (R 32.2f). The required value of the force of the resistance can be provided by selecting the dimensions (mass) of the valve 6 or by installing the spring.

The invention makes it possible to increase the depth of the ventilation channels to 0.8 mm and, thus, to increase the efficiency of the ventilation of the mold, to improve the condition of filling the metal: LOM form.

fig 2

Claims (2)

PRESS FORM FOR CASTING UNDER PRESSURE, containing movable and stationary half-molds with a working cavity, a washer cavity, in the lower part connected by a ventilation channel to the working cavity, and in the upper part with the atmosphere, and a valve installed in the washer cavity can be moved in the direction of movement metal flow, characterized in that, in order to reduce the back pressure of gases and. to improve the mold ventilation conditions, the washer cavity is located in one of the half-molds, and in the other half-form there is an additional ventilation channel connecting the volume of the washer cavity under the valve with the volume above the valve. φν ·· 1 2 one