SU899235A1 - Unit for producing casting moulds by pulse method - Google Patents

Description

one

The invention relates to foundry, in particular to devices for the manufacture of foundry forms in a pulsed manner, and is used in automatic molding lines.

A known apparatus for the manufacture of casting molds, comprising a lower and upper crossbar, connected by jagged columns, a bunker, a pulsing mechanism installed in the lower plane of the upper crossbar, a lifting table with a hydraulic cylinder mounted on the lower crossbar. The pulse charging mechanism consists of a pulse head connected to a box-shaped dispenser having a fixed tray. Moving them from the working position to the initial position is carried out by jQ of the l-l hydraulic cylinder rod.

The disadvantage of the device is that during the return stroke of the dispenser, the excess mixture, which is above the control of the filling frame, is cut off and pressed into the filling frame. The amount of the pressed-in mixture is directly proportional to the movement of the rear wall of the box-shaped dispenser when it returns to its original position. As a result

The mixture is condensed along shear planes in the filling frame on the side of the metering box and in the metering box itself on the side of the pulse head. In places of maximum subcompaction, the density measured by a 071 hardness gage reaches 56 units.

The density of the mixture in the flask and the filling frame is uneven in volume, which is the reason for the poor-quality compaction of the forms, since the form has loose and slack in volume.

In addition, subcompaction of the mixture along the shear planes can lead to a displacement of the model on the model plate. This leads to low-quality castings.

As shown by the operation of pulsed molding plants, good results with a pulsed mixture compaction method are obtained by pressing the upper layers of the mixture in the filling frame. The compacted upper layer of the mixture works as a diaphragm and the half-form is of good quality.

With uneven density of the upper layers of the mixture in the filling frame, the speed of movement of differently compacted regions of the mixture during a pulse is different. This leads to an uneven compaction of the mixture in the mold half and, moreover, creates large shear forces acting on the model.

The purpose of the invention is to improve the quality of the casting molds produced by leveling the surface density of the mixture in the filling frame and eliminating the shear of the model.

The goal is achieved by the fact that in the device containing the upper and lower traverses connected by columns, mounted on the upper traverse of the bunker, a pulse head with a divider connected to a box-shaped dispenser, a filling frame and a lifting table with a hydraulic cylinder, the divider is made with a protrusion having an inclined lower surface , while the large height of the protrusion is located opposite to the side of the box-shaped dispenser side and the dimensions of the protrusion in the plan correspond to the dimensions of the filling frame in the light.

FIG. 1 shows the proposed installation in the initial position; in fig. 2 - the same, in the position of compaction of the upper layers of the mixture, by a divider with a protrusion entering the cavity of the filling frame before the impulse

The plant for the manufacture of casting molds contains columns 2 connected to the upper 2 and lower 3 traverses fixed on the upper traverse 2 hopper 4, pulse head 5 with a divider b connected to the box-shaped metering device 7 and moved by means of the hydraulic cylinder 8, filling frame 9 and lifting table 10 with hydraulic cylinder 11. A sub-model plate 12 and an epoch 13 are installed on a lifting table 10.

The installation works as follows.

Before starting work, the flask 13 and the filling frame 9 are installed on the sub-model plate 12.

The hopper 4 is filled with molding sand and the box-shaped dispenser 7, together with the pulse head 5, is moved to the left by means of the hydraulic cylinder 8 (Fig. 1) until the outlet of the hopper 4 is aligned with the box-shaped dispenser 7, the filling frame 9 and the flask 13.

At the same time, the molding mixture under the action of its own weight is poured out from the hopper 4, filled with a flask 13, an extra frame 9 and a final dispenser 7.

When the box-shaped metering unit 7 is moved with the help of the hydraulic cylinder 8 to the initial position, the molding mixture in the filling frame receives a subcompaction, with a larger subassembly (due to enveloping the mixture) from the rear wall A of the boxed dispenser, and a smaller one on the opposite side.

After pressing the system (under-model plate 12, flask 13, filling frame 9, pulse head 5 with divider 6), the divider 6 with its projection c inclined surface enters the opening of the filling frame 9 to equalize the density of the upper layers of the mixture.

After a pulse has been effected (compaction of the mixture), the lifting table 10 with the sub-model plate 12 and the flask 13 is lowered, the semi-mold is finished, and the cycle is repeated.

The proposed execution of the pulverider puller provides alignment of the upper layers of the mixture in the filling frame, which ensures uniform density of the mixture in the filling frame and flask, and this, in turn, eliminates the shear forces acting on the model during the impulse. All this allows to obtain a high-quality casting mold having the same density of compacted molding sand throughout the entire volume.

The application of the present invention allows to reduce the casting and increase the resistance of the model due to the elimination of shear forces acting on the model during the impulse and caused by the uneven density of the mixture during backfilling.

Claims (1)

1. Procurement production. Thematic collection of scientific works of the Kramatorsk Scientific Research and Design Institute of Mechanical Engineering, 1974, no. 15, s. 12 and 13.