EP 0403040 B1 19931103 - Method and apparatus for making dimensionally stable pressed articles.
Title (en)
Method and apparatus for making dimensionally stable pressed articles.
Title (de)
Verfahren und Vorrichtung zur Herstellung masshaltiger Presslinge.
Title (fr)
Procédé et dispositif pour fabriquer des articles pressés à dimensions exactes.
Publication
Application
Priority
DE 3919847 A 19890615
Abstract (en)
[origin: EP0403040A2] The invention relates to a method and an apparatus for making dimensionally stable pressed articles from pulverulent compositions, in particular metal powder, on a press in a compression mould with at least one upper die and at least one lower die, in which the pressing dies in the final pressing position are moved to predetermined theoretical positions, and, during the pressing, the progression of the compressive force of at least one of the dies is recorded as a function of the travel and compared in each case with a predetermined, travel-dependent tolerance range for the compressive force. In order to provide a method and an apparatus which permit even closer tolerances as regards the dimensional accuracy of the pressed articles and at the same time further reduce the risk of defective production, it is proposed that, if the tolerance range is exceeded, the theoretical position of the die in question in the final pressing position is modified so that the height of the pressed article in the final pressing position is reduced by an amount which corresponds to the increased upward expansion of the pressed article after its unmoulding, associated with the higher final pressing force, and the reverse procedure is adopted if the compressive force falls below the tolerance range. <IMAGE>
IPC 1-7
IPC 8 full level
B30B 11/02 (2006.01); B22F 3/02 (2006.01); B30B 11/00 (2006.01); G05D 5/00 (2006.01)
CPC (source: EP US)
B22F 3/02 (2013.01 - EP US); B30B 11/005 (2013.01 - EP US); B30B 15/0094 (2013.01 - EP US)
Designated contracting state (EPC)
AT CH DE ES FR GB IT LI SE
DOCDB simple family (publication)
EP 0403040 A2 19901219; EP 0403040 A3 19910306; EP 0403040 B1 19931103; AT E96732 T1 19931115; DE 3919847 A1 19901220; DE 3919847 C2 19910328; DE 59003294 D1 19931209; JP H0327897 A 19910206; JP H082519 B2 19960117; US 5024811 A 19910618
DOCDB simple family (application)
EP 90250140 A 19900531; AT 90250140 T 19900531; DE 3919847 A 19890615; DE 59003294 T 19900531; JP 15497090 A 19900613; US 53906590 A 19900615