Metal founding – Means to shape a forming surface – Including means for compacting particulate fluent mold...
Patent
1985-08-02
1986-10-28
Godici, Nicholas P.
Metal founding
Means to shape a forming surface
Including means for compacting particulate fluent mold...
164 37, B22C 1500
Patent
active
046193073
DESCRIPTION:
BRIEF SUMMARY
The invention relates to an apparatus for the compression of foundry moulding material by means of pressure or compression gas comprising a pressure vessel for the pressure gas forming an initial pressure chamber, a moulding chamber positioned below the pressure vessel and comprising a moulding box with a sand frame and a pattern plate with a pattern closing off the moulding box at the bottom and onto which the moulding material is loosely heaped up prior to compression and a large-area valve arranged between the pressure vessel and the moulding chamber and whose closure member releases the valve opening in a few milliseconds under the joint action of the pressure in the pressure vessel, moves into the moulding chamber and can be brought into the closed position by means of a pressure cylinder.
In U.S. Pat. No. 4,529,026, a process and an apparatus for compressing foundry moulding material, particularly moulding sand by means of pressure gas, e.g. compressed air or pressure gas produced by explosive combustion are described, the pressure gas being expanded in sudden bursts from a pressure vessel into the moulding chamber, whereby it acts on the free moulding material surface and compresses the moulding material particles accompanied by the reciprocal exchange of momentum, together with a delay of the accelerated moulding material mass on the top of the pattern and the pattern plate, fluidizing effects also occurring, accompanied by the reduction of particle friction. Importance is attached to a high gas mass throughput with the speediest possible pressure rise in the moulding chamber. The lower the initial pressure in the pressure vessel, the higher these parameters must be, initial pressure being sought which are in the range of the pressure of operational compressed air network, so that excessive constructional expenditure is not required for the pressure gas production or for controlling the pressure. Thus, the apparatus must have a closure member, which on the one hand closes a maximum cross-section for the overflow of the pressure gas and on the other hand has a minimum mass, in order to release the cross-section as rapidly as possible. This also requires opening drives, which bring the closure member into the open position in a few milliseconds and consequently release the cross-section. The aforementioned requirements cannot be satisfied by conventional valve constructions.
In an earlier-dated patent application (DE: No. P33 21 622.3, U.S. Pat. No. 617,920, JP: No. 59-122 180, EP: No. 84 10 6795.2), the pressure gradient between the pressure vessel and the moulding chamber is utilized for the opening of the valve, in that the closure member leads into the pressure vessel and its opening movement is directed into the moulding chamber. The closing drive for the closure member is a pressure cylinder, whose piston is connected to a guide rod of the closure member. In the closed position, the guide rod is fixed by means of a clamping device. At least during the opening movement, the pressure cylinder is disengaged from the guide rod so that it does not have to work against the pressure in the pressure cylinder. The drive connection is then restored again and the closure member is again brought back into the closed position by the guide rod.
The object of the present invention is to so further develop the previously described apparatus that, with minimum constructional expenditure, a still higher opening speed for the closure member is obtained.
According to the invention, this object is solved in that on the lift or stroke side, the piston of the pressure cylinder is connected to a high pressure source and with its opposite side forms the movable termination of a pressure reservoir subject to the action of the gas and that the high pressure side outflow is constructed in such a way that the pressure flows out at a speed of >10 m/s, accompanied by the simultaneous acceleration of the piston under the pressure in the pressure reservoir and the closure member into the open position.
In the case of the co
REFERENCES:
patent: 3659642 (1972-05-01), Vasilkovsky et al.
patent: 4546810 (1985-10-01), Landolt
patent: 4572274 (1986-02-01), Zimmermann
Damm Norbert
Muller Gunter
Batten, Jr. J. Reed
BMD Badische Maschinenfabrik Durlach GmbH
Godici Nicholas P.
LandOfFree
Apparatus for compressing foundry moulding material by pressure does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for compressing foundry moulding material by pressure , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for compressing foundry moulding material by pressure will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1341718