Mannesmann Aktiengesellschaft

Mannesmann Aktiengesllschaft

Siegfried Radewahn

Norbert Nies

Gerd Hinzmann

Walter Solty

Theodor Gormanns

The present invention relates to a method and apparatus for the manufacture of finished parts by the sintering of compacts which are formed as composite moldings of a pulverulent base material and at least one other pulverulent material, particularly different metal powders. The compacts are produced in the manner that at least one of the powder materials is introduced in pourable condition directly alongside of an already pre-compacted part of the compact into the mold which has a shell-shaped matrix and the powder materials are subjected together to final compacting by plug forces acting from on top and on bottom to the size desired for the sintering. In order to improve the traditional method so that moldings with vertically extending separation lines between the individual portions of the composite material can be produced without the previous disadvantages and provide an apparatus on which the compacts can be produced in accordance with this method, at least two powder materials are introduced, one after the other, in pourable condition into the individual regions of the filling volume of the mold which are to be opened, at least one pre-compacting of the powder material already introduced being affected until dimensional stability is obtained before the next powder material is introduced alongside of the pre-compacted material and is pre-compacted in similar manner, and that only then is the joint final compacting effected.

Method and apparatus for manufacturing finished parts as composite

A plurality of rams in a pressing machine are movable into and out of a predetermined position to compress power material and shape a die-formed part. The rams are advanced to a pre-selected spaced relationship to form a desired configuration of the die-formed part. Strain gauges are mounted on each ram to detect during the pressing operation elastic deformation, altering the dimension of the ram and the shape of the die-formed part. In response to detected elastic deformation, the strain gauges transmit a signal through a controller to a readout device for recording the magnitude of ram deformation. Thereafter, the press drive mechanism is actuated to move the rams to compensate for the change in dimension of the rams so that the rams are repositioned to maintain the desired spaced relationship for a predetermined configuration of the die-formed part.

Process and apparatus for the manfuacture of dimensionally accurate

Precision compacts are produced from powdered material in a mold having at least one top plug and at least one bottom plug between which plugs the powdered material is compressed. The course of the pressing force of at least one of the plugs is detected as a function of the path of its travel during compression, and compared with a predetermined path-dependent tolerance range of the pressing force. Upon exceeding such tolerance range, the final pressing position of the plug in question is changed in such a manner that the height of the compact in such final pressing position is reduced by an amount corresponding to the increased springing back of the compact upon its removal from the mold that results from the greater final pressing force. In the absence of exceeding such tolerance range, the final pressing position of the plug in question is changed in such a manner that the weight of the compact in such final pression position is increased by an amount corresponding to the decreased springing back of the compact upon its removal from the mold that results from the lesser final pressing force.

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Monchen-gladbach, Germany

Siegfried Radewahn