Method and apparatus for vibration casting of vehicle wheels

Abstract

A vehicle wheel mold is vibrated at a frequency within a range of 0.1 to 10,000 Hz during a casting process. The vibration reduces the solidification time needed to form a wheel casting while improving the tensile strength of the wheel.

What is claimed is:  
     
         1 . An apparatus for casting a one piece vehicle wheel comprising: 
 a mold base segment;    a plurality of movable mold side segments;    a movable top core segment, said top core segment co-operating with said base and side segments to define a gravity fed mold cavity for gravity casting a vehicle wheel; and    a vibration device mounted upon one of said mold segments, said vibration device being operative to selectively vibrate said mold segment at a frequency within a range of 0.1 to 10,000 Hz whereby the cooling of molten metal contained within said mold cavity is accelerated and the mechanical strength the resulting cast vehicle wheel is enhanced.    
     
     
         2 . The apparatus according to  claim 1  wherein said vibration device is operative to selectively vibrate said mold segment at a frequency within a range of 1 Hz to 1,000 Hz.  
     
     
         3 . The apparatus according to  claim 2  further including a timer device connected to said vibration device, said timer device operative for controlling the duration of the mold vibration.  
     
     
         4 . The apparatus according to  claim 3  wherein said vibration device is pneumatically powered and adapted to be connected to a supply of compressed air and further wherein the apparatus includes a solenoid valve for controlling the flow of compressed air into said vibration device and an adjustable pressure regulator for controlling the frequency and force of said vibration device.  
     
     
         5 . The apparatus according to  claim 3  wherein said vibration device is electrically actuated.  
     
     
         6 . The apparatus according to  claim 5  further including a frequency controlling device connected to said vibration device, said frequency controlling device operative to vary the frequency of vibration as a function of time.  
     
     
         7 . The apparatus according to  claim 5  further including a manifold mounted upon said mold and communicating with said mold cavity, said manifold operative to inject an inert gas into said mold cavity.  
     
     
         8 . The apparatus according to  claim 7  wherein said inert gas is helium.  
     
     
         9 . A method for forming a one piece vehicle wheel casting comprising the steps of: 
 (a) providing a multi-segment gravity fed mold for gravity casting the vehicle wheel, the mold having a vibration device mounted upon a segment thereof, the vibration device being selectively operable to vibrate the mold;    (b) filling the cavity of the wheel mold by gravity with a charge of molten metal;    (c) activating the vibration device to vibrate mold at a frequency within the range of 0.1 Hz to 10,000 Hz upon completion of the filling of the mold cavity with molten metal;    (d) deactivating the vibration device;    (e) opening the mold; and    (f) removing the wheel casting from the mold.    
     
     
         10 . The method according to  claim 9  further including, subsequent to step (d), allowing the metal in the mold cavity to continue to cool before the mold is opened.  
     
     
         11 . The method according to  claim 10  wherein the top core is vibrated in step (c) after a predetermined time period has elapsed following the filling of the mold cavity.  
     
     
         12 . The method according to  claim 10  wherein the vibration device provided in step (a) is pneumatically powered.  
     
     
         13 . The method according to  claim 10  wherein the vibration device provided in step (a) is electrically powered.  
     
     
         14 . The method according to  claim 10  further including a manifold mounted upon the wheel mold, the manifold in communication with the mold cavity, and further wherein step (d) includes using the manifold to inject an inert gas into the mold cavity.  
     
     
         15 . The method according to  claim 14  wherein the inert gas is helium.  
     
     
         16 . A method for forming a one piece vehicle wheel casting comprising the steps of: 
 (a) providing a multi-segment gravity fed wheel mold for gravity casting the vehicle wheel, the mold having a vibration device mounted upon a segment thereof, the vibration device being selectively operable to vibrate the mold;    (b) activating the vibration device to vibrate the wheel mold at a frequency within a range of 0.1 Hz to 10,000 Hz;    (c) filling the cavity of the wheel mold by gravity with a charge of molten metal;    (d) continuing to vibrate the top core while the molten metal cools;    (d) deactivating the vibration device;    (e) opening the mold; and    (f) removing the wheel casting from the mold.    
     
     
         17 . The method according to  claim 16  further including, subsequent to step (d), allowing the metal in the mold cavity to continue to cool before the mold is opened.  
     
     
         18 . The method according to  claim 17  wherein the vibration device provided in step (a) is pneumatically powered.  
     
     
         19 . The method according to  claim 17  wherein the vibration device provided in step (a) is electrically powered.  
     
     
         20 . The method according to  claim 17  further including a manifold mounted upon the wheel component mold, the manifold in communication with the mold cavity, and further wherein step (d) includes using the manifold to inject an inert gas into the mold cavity.  
     
     
         21 . The method according to  claim 20  wherein the inert gas is helium.