US 4,915,159 AGranted

Method and apparatus for compacting foundry mold making material about a foundry mold pattern

AssigneeBMD Badische Maschinenfabrik Durlach GmbH

InventorsNorbert Damm, Ernst Schmitt, Thomas Parr

Life of this patent

Estimating the term…

Loading patent…

Abstract

To permit close matching of compaction pressure being applied to foundry mold making material, such as foundry sand, to the shape of a mold pattern (2) in a pattern box (3, 4), individual fluid pressure is applied to a plurality of press plungers (7) located on a pressure plate which is moved towards the sand in the mold box at a high rate of speed, the press plungers being biassed by fluid pressure to have a maximum difference (.DELTA.H) in stroke of penetration depth of at least 30% of the height (H) of the mold box; individual valves (14) can apply compressed air to individual cylinders under control, for example, of a microprocessor; the valves can be located in a matrix arrangement (FIG. 3). The method and apparatus can be used in combination with explosion or pressure impulse compaction and fluidizing of the foundry sand.

Claims40

Dependent claims

Method of compacting foundry molding material utilizing a molding machine,

said molding machine having
a mold box (3);
a mold pattern (2) in the mold box;
foundry molding material (5) surrounding the pattern and filling the mold box;
a pressure plate (8);
a plurality of press plungers (7), respective press plungers being located spaced from each other on the pressure plate in a predetermined pattern for penetration into the molding material in accordance with the shape of the mold pattern (2)
wherein the sum of the cross-sectional areas of the press plungers is between 20% to 70% of the cross-sectional area of the mold box (3);
and
pressure means (12) acting on the press plungers,
said method comprising the steps of
applying pressure by said pressure means (12) individually, to the press plungers (7) in accordance with the shape of the mold pattern (2) for compacting the molding material around the pattern in accordance with the shape of the pattern;
then applying the pressure plate (8) against the molding material for compacting the molding material, by moving the pressure plate to about the upper edge of the mold box (3);
and
wherein said step of applying pressure on the press plungers comprises
applying said pressure at a level to generate, at the end of the step of compacting the molding material by the pressure plate, on at least one of the press plungers (7) a maximum difference (.DELTA.H) in level of penetration or stroke of movement between individual press plungers (7) which is at least 30% of the height (H) of the mold box (3).

12 more elements

A molding machine for compacting foundry molding material having

a mold box (3);
a mold pattern (2) in the mold box;
foundry molding mold material (5) surrounding the pattern and filling the mold box;
a pressure plate (8);
a plurality of press plungers (7), respective press plungers being located spaced from each other on the pressure plate in a predetermined pattern for penetration into the molding material in accordance with the shape of the mold pattern (2),
wherein the sum of the cross-sectional areas of the press plungers is between 20% to 70% of the cross-sectional area of the mold box (3);
and
pressure means (12) acting on the press plungers,
said machine comprising
a plurality of pressure cylinders (10), one each coupled to a respective press plunger (7);
individual valve means (14, 15, V.sub.1, V.sub.2...V.sub.A=l , V.sub.B...) interposed between at least those pressure cylinders which are located in a central region of the pressure plate and the fluid pressure means for individual control of penetration of the plungers into said molding material (5) in accordance with the shape of the mold pattern (2);
power means (13) coupled to said pressure plate (8, 308), to move the pressure plate in compacting direction toward said molding material (5) in the mold box (3);
and
control means (20) for controlling said valve means (14, 15, V.sub.1, V.sub.2...V.sub.A, V.sub.B...) and said power means (13) for sequentially applying fluid pressures to the respective press plungers (7) to engage the plungers with said molding material (5) and then engage the pressure plate (8, 308) with the molding material.

11 more elements

Dependencies are inferred from the claim text.