Control of Metal Cold Forming Machines

Abstract

A metal forming machine for cold forming a metal product to a desired dimension and/or configuration includes a forming means with at least one movable part for applying load to the metal product. A position sensing means establishes a measured position of the movable part indicative of a measured dimension and/or configuration of the metal product, and a load measuring means establishes a measured load applied by the moving part. A control means selects a nominal load (nom load) setting to achieve the desired dimension and/or configuration (pos nom), and enables actuation of the forming means until a calibration load (cal load) is reached where the position sensing means establishes the measured dimension and/or configuration (pos cal), whereupon the load is lowered. The control means then establishes a new load setting as a function of (pos nom) minus (pos cal), and reactivates the forming means to the new load setting to form the metal product.

1 . A metal forming machine for plastically cold forming a metal product to a desired dimension and/or configuration, said machine including:
 a forming means including a movable part for applying load to a metal product to cold form said metal product therefrom during a forming operation;   a position sensing means for establishing a measured position of said movable part indicative of a measured dimension and/or configuration of the metal product to be formed;   a load measuring means for establishing a measured load applied by said forming means during a said forming operation;   control means enabling actuation of said forming means including means for selecting a nominal load (nom load) setting to achieve the desired dimension and/or configuration (pos nom), said control means enabling actuation of said forming means until a calibration load (cal load) is reached where the position sensing means establishes a said measured dimension and/or configuration (pos cal) at said (cal load), whereupon the load is lowered, said control means establishing a new load setting as a function of the difference between (pos nom) and (pos cal), and said control means thereafter reactivating said forming means to said new load setting to form said metal product with the desired dimension and/or configuration, and said control means acting to remove said load thereafter.   
     
     
         2 . A metal forming machine according to  claim 1  wherein the control means includes recording means to record the measured dimension and/or configuration established by said position sensing means, at least at said new load setting reached after reactivation of said forming means. 
     
     
         3 . A metal forming machine according to  claim 2  wherein the recording means provides reproducible data effectively showing the finished measured dimension and/or configuration. 
     
     
         4 . A metal forming machine according to  claim 1  wherein the control means includes a microprocessor. 
     
     
         5 . A metal forming machine according to  claim 1  wherein the forming operation occurs within the range of 100 to 2000 milliseconds, preferably about 500 milliseconds. 
     
     
         6 . A metal forming machine according to anyone of  claim 1  wherein the calibration load (cal. load) is no more than 20% of said nominal load (nom. load), preferably about 10% of said nominal load (nom. load). 
     
     
         7 . A metal forming machine according to  claim 1  wherein the metal forming machine is a swage or crimping press, the forming means including a plurality of press jaws surrounding a press zone and adapted to move inwardly into the press zone during a said forming operation. 
     
     
         8 . A metal forming machine according to  claim 7  wherein the forming means of the press includes a hydraulically operated piston means to radially simultaneously move said press jaws into said press zone during a said forming operation. 
     
     
         9 . A method of plastically cold forming a metal work product such as an annular metal ferrule or casing in a press zone of a crimping or swaging press having a plurality of press jaws movable for applying load to the metal work product, said press further including a position sensing means for sensing an effective position of said press jaws indicative of a measured dimension and/or configuration of the work product, said press also including a load measuring means for establishing a measured load applied by said press jaws during a cold forming process, said method including the steps of:
 selecting a nominal load (nom load) setting to achieve a desired dimension and/or configuration (pos nom),   actuating the press jaws until a calibration load (cal load) is reached where the position sensing means establishes a measured dimension and/or configuration (pos cal) at said (cal load),   lowering the load on said press jaws,   establishing a new load setting as a function of the difference between (pos nom) and (pos cal),   reactivating the press jaws to the new load setting to form said work product with the desired dimension and/or configuration, and thereafter   removing load from said press jaws.