Method and apparatus for adaptive powder fill adjustment on powder metal compacting presses

An automatic adaptive fill cavity adjust system for a powder metal press to control trend variations in the weight of multi-level parts, said press comprising a movable top platen, a die mounted in said top platen, additional movable platens therebeneath, a punch mounted on at least one of said additional platens, a stationary punch and a stationary support therefor, and an up stop for each of said top platen and said additional movable platens determining the vertical positions thereof, said system comprising monitoring means for monitoring one of press tonnage change and part weight change, said system further comprising a computer control means for keeping a running average of said change for small samples each comprising a predetermined number of said parts, for determining when an adjustment of said fill cavity is required, and for calculating new fill positions for said top platen and each punch bearing movable platen such that the percent change of power column height over each punch is the same, said system also comprising motor drive means controlled by said computer control means for vertically shifting each of said up stops of said top platen and each of said punch bearing movable platens to cause said platens to achieve their new fill positions in accordance with said newly calculated fill positions.

A method of automatically adjusting the fill cavity of a powder metal press to control trend variations in the weight of multi-level pans, wherein said fill cavity, when filled with powdered metal, has a plurality of powder column heights corresponsing to the various levels of the multi-level pans to be produced, comprising the steps of:

• monitoring the part weight as said parts are produced, keeping a running average of said part weight for small samples each comprising a predetermined number of said parts, calculating a fill multiplier when a sample average exceeds a predetermined percentage of part tolerance, wherein said fill multiplier is calculated utilizing the amount by which said sample average exceeds a predetermined desired tonnage, calculating new fill positions for each tool bearing movable platen and the core rod mechanism if used utilizing said fill multiplier, such that the percent change in powder column height is the same for all powder columns, and positioning the up stop of each of said platens, and said core rod mechanism if used at said new fill positions to achieve a proportionally correct adjustment of said fill cavity.