Process and blank for preparing rhomboidal blades for axial turbo engines

Abstract

A rhomboidal blade includes a blade footing ( 2 ) of rhomboidal cross section and a blade body ( 1 ) for axial turbo engines is worked out from a solid blank ( 3 ) by machining. The blank ( 3 ) is cut off as a bar from a hot-rolled, bar-shaped input stock, whose cross section has the shape of a rhomboid which is adapted to the shape of the cross section of the rhomboidal blade footing ( 2 ). The blank is larger on all size than the maximum cross section of the blade by only the minimum oversize ( 5 ) for machining.

What is claimed is:  
     
         1 . A process for manufacturing rhomboidal blades for axial turbo engines, the blade having a blade footing of a rhomboidal cross section and a blade body, in which the blade is worked out of a solid blank by machining, the process comprising the steps of: 
 using a starting material manufactured by hot forming bar-shaped input stock to provide a starting material cross section having the shape of a rhomboid adapted to the shape of the cross section of the rhomboidal blade footing and being larger on all sides than the maximum cross section of the blade only by the minimum oversize for machining; and    cutting a blank from the starting material having a length corresponding to the length of the blade or having a length corresponding to the length of the blade increased by clamping ends necessary for the machining.    
     
     
         2 . A process in accordance with  claim 1 , wherein the bar-shaped input stock is manufactured by hot rolling.  
     
     
         3 . A process in accordance with  claim 1 , wherein the bar-shaped input stock is manufactured by drop forging or press forging.  
     
     
         4 . A process in accordance with  claim 1 , wherein the bar-shaped input stock is manufactured by precision forging.  
     
     
         5 . A blank for manufacturing a rhomboidal blade for axial turbo engines, the blade having a blade footing of rhomboidal shape and a blade body by machining to the finished size of the blade, the blank comprising: 
 a bar cut off from input stock bar-shaped manufactured by hot forming, the input stock having a cross section is adapted to the cross section of the rhomboidal blade footing and being larger on all sides than a maximum cross section of the blade by a minimum oversize for machining.    
     
     
         6 . A blank according to claims  5 , wherein said minimum oversize for machining is from 1 to 3 mm.  
     
     
         7 . A blank according to claims  5 , wherein said minimum oversize for machining is about 2 mm.