Method and apparatus for molding by forging

Abstract

The invention is directed to provide a forming method and a forming apparatus that are, without extending a processing time compared with the conventional practice, capable of sufficiently lubricating a formed object and forming at safety without the lubricant igniting under pressure. In an extruding apparatus, a workpiece is successively transferred to a series of press stages, a conveying unit successively transferring the workpiece is provided with a nozzle for spraying the workpiece with lubricant, and the workpiece and the nozzle are located in fixed relative positions to each other in spraying the workpiece with the lubricant.

1 . A forging method including a plurality of press steps for a formed product, wherein a workpiece heated due to the machining in an earlier press step(s) prior to a press step of forming the workpiece undergoes spraying with lubricant more than once; the spraying with lubricant is conducted when the lubricant sprayed in a preceding spraying has been dried; and eventually after the lubricant sprayed in the final spraying has been dried, the press step of forming the workpiece is conducted.  
   
   
       2 . A forging method as defined in  claim 1 , wherein the workpiece is a constant-velocity universal joint outer race.  
   
   
       3 . A forging method as defined in  claim 1 , wherein a temperature of the workpiece ranges from 150 to 250° C. when the workpiece is sprayed with lubricant.  
   
   
       4 . A forging method as defined in  claim 1 , wherein the lubricant before a forging procedure is a water-dispersive lubricant containing a solid lubricant agent, a lubricative and dispersive adherent agent and a wetting and vaporizing accelerating agent, and the lubricant during the forging procedure is a solid lubricant agent.  
   
   
       5 . A forging method as defined in  claim 1 , wherein the formed product is cup-shaped.  
   
   
       6 . A forging method as defined in  claim 1 , wherein the formed product is shaft-shaped.  
   
   
       7 . A forging apparatus comprising an extruding apparatus, wherein a workpiece is successively transferred to a series of press stages; a conveying unit for successively transferring the workpiece is provided with a nozzle for spraying the workpiece with lubricant; and the workpiece and the nozzle are located in fixed relative positions to each other in spraying the workpiece with the lubricant.  
   
   
       8 . A forging apparatus as defined in  claim 7 , wherein the spraying with lubricant is conducted intermittently.  
   
   
       9 . A forging apparatus as defined in  claim 7 , wherein there are more than one of the nozzles from which the lubricant is sprayed in different directions, and the nozzles spray the lubricant in a sequential fashion.  
   
   
       10 . A forging apparatus as defined in  claim 9 , wherein after the lubricant sprayed from the nozzles has been dried, the lubricant is sprayed from the nozzles.  
   
   
       11 . A forging apparatus as defined in  claim 7 , wherein the workpiece is a constant-velocity universal joint outer race.  
   
   
       12 . A forging apparatus as defined in  claim 7 , wherein a temperature of the workpiece ranges from 150 to 250° C. when the workpiece is sprayed with lubricant.  
   
   
       13 . A forging apparatus as defined in  claim 7 , wherein the lubricant before a forging procedure is a water-dispersive lubricant containing a solid lubricant agent, a lubricative and dispersive adherent agent, and a wetting and vaporizing accelerating agent, and the lubricant during the forging procedure is a solid lubricant agent.  
   
   
       14 . A forging apparatus as defined in  claim 7 , wherein the formed product is cup-shaped.  
   
   
       15 . A forging apparatus as defined in  claim 7 , wherein the formed product is shaft-shaped.