Ultrasonic powdered metal compaction

Abstract

An apparatus for making cores for ignition coil assemblies using powdered metal having magnetically permeable material is disclosed. The apparatus includes an ultrasonic tool that includes a cavity having a first axis. The tool vibrates to provide radial compression of powdered metal placed in the cavity. The apparatus also includes a first ram and a second ram. The cavity is located between the rams; the rams are located along the first axis. The rams are configured for opposing movement toward the cavity to provide axial compression of the powdered metal placed in the cavity. The apparatus also includes a control unit that controls the operation of the ultrasonic tool and the rams, allowing for simultaneous radial and axial compression of the powdered metal for a pre-determined time into a completed core. The control unit also controls removal of the core.

1 . An apparatus for making cores using powdered metal having magnetically permeable material, said apparatus comprising: 
 an ultrasonic tool, wherein said ultrasonic tool includes a cavity having a first axis, wherein said tool vibrates to provide radial compression;    a first and second ram, each located along said first axis, wherein said cavity is located between said rams, said rams being configured for opposing movement toward said cavity to provide axial compression;    a means for simultaneously controlling said radial compression provided by said tool and said axial compression provided by said first and second rams.    
     
     
         2 . The apparatus of  claim 1  further comprising a respective pair of boosters and converters and a power source wherein said power source comprises two power supplies operating in phase with each other.  
     
     
         3 . The apparatus of  claim 1  wherein said first and second rams are retractable along said first axis to facilitate removal of the completed core.  
     
     
         4 . The apparatus of  claim 1  wherein said two rams are retractable along a second axis, wherein said second axis is substantially normal to said first axis to facilitate removal of the completed core.  
     
     
         5 . The apparatus of  claim 1  wherein said ultrasonic tool vibrates at about 20 kHz.  
     
     
         6 . A method of making a core using powdered metal having magnetically permeable material, comprising the steps of: 
 providing an ultrasonic tool having a cavity;    filling said cavity with powdered metal, wherein said cavity is located between first and second rams, configured for opposing movement along a first axis;    moving said rams toward each other into said cavity to compress said powdered metal; and    simultaneously with said moving step, vibrating said tool.    
     
     
         7 . The method of  claim 6  wherein said moving step and said vibrating step are performed for a pre-determined amount of time to transform said powdered metal into a completed core.  
     
     
         8 . The method of  claim 7  further comprising the step of retracting one of said rams to facilitate removal of said core.  
     
     
         9 . The method of  claim 8  further comprising the step of moving said ram not retracted into said cavity toward said completed core, thereby pushing said completed core from said cavity.  
     
     
         10 . The method of  claim 8  further comprising the step of vibrating said tool to aid in removal of said core from said cavity.  
     
     
         11 . The method of  claim 6  wherein said metal particles are selected from the group consisting of iron and iron alloys.  
     
     
         12 . The method of  claim 7  wherein the size of said metal particles prior to compression are from about 5 to about 400 micrometers.  
     
     
         13 . A method of making a powdered metal core for an ignition coil comprising the steps of: 
 providing an ultrasonic tool having a cavity;    filling said cavity with powdered metal, wherein said cavity is located between first and second rams, configured for opposing movement along a first axis;    moving said rams toward each other into said cavity to compress said powdered metal;    simultaneously with said moving step, vibrating said tool; and    removing said compressed metal core from said cavity.    
     
     
         14 . The powdered metal core of  claim 13  wherein said powdered metal are magnetically permeable.  
     
     
         15 . The powdered metal core of  claim 13  wherein said powdered metal is selected from the group consisting of iron and iron alloys.  
     
     
         16 . The powdered metal core of  claim 13  wherein the particle size of said powdered metal prior to compression is from about 5 to about 400 micrometers.  
     
     
         17 . The powdered metal core of  claim 13  wherein said removing step further comprises the step of retracting one of said rams to facilitate removal of said core.  
     
     
         18 . The powdered metal core of  claim 17  wherein said removing step further comprises the step of moving said ram not retracted into said cavity toward said core, thereby pushing said core from said cavity.  
     
     
         19 . The powdered metal core of  claim 18  wherein said removing step further comprises the step of vibrating said tool to aid in removal of said core from said cavity.