Method for machining a stainless steel exhaust manifold for a multi-cylinder combustion engine

Abstract

A method is provided for machining the stainless steel automotive exhaust components that allows such components to be machined in high volumes and at a reasonable cost. An exemplary embodiment of the method includes the steps of: (a) supporting the manifold on a work structure; (b) clamping the manifold to the work structure; and (c) machining the supported and clamped manifold; (d) where the clamping step includes the step of clamping each of the plurality of inlet coupling flanges of the manifold separately; and (e) the machining step includes the step of machining the interface surfaces of the inlet coupling flanges. In a more detailed embodiment, the supporting and clamping steps orient the planes of the interface surfaces of the inlet coupling flanges of the manifold perpendicular to a spindle access of the milling machine.

1 - 41 . (canceled)  
   
   
       42 . A method for machining a stainless steel exhaust manifold for a multi-cylinder combustion engine, the exhaust manifold having a manifold body that includes a plurality of inlet tubes in fluid communication with at least one outlet, each of the inlet tubes having an inlet mouth and a coupling flange extending radially therefrom, the outlet having an outlet mouth and a coupling flange extending radially therefrom, each of the inlet coupling flanges having an interface surface adapted to mate with the engine block, and the outlet coupling flange having an interface surface adapted to mate with the exhaust assembly, the method comprising the steps of: 
 supporting and clamping the manifold on a first work structure such that the inlet coupling flange interface surfaces are oriented on a plane substantially perpendicular to the spindle axis of the milling machine;    machining the inlet coupling flange interface surfaces of the manifold supported and clamped on the first work structure;    drilling coupling holes in through the inlet coupling flange interface surfaces of the manifold supported and clamped on the first work structure;    removing the manifold from the first work structure;    supporting and clamping the manifold on a second work structure such that an additional interface surface is oriented on a plane substantially perpendicular to the spindle axis of the milling machine;    machining the outlet coupling flange interface surface of the manifold supported and clamped on the second work structure; and    the step of supporting and clamping the manifold on the second work structure including the steps of seating a plurality of coupling holes drilled through the inlet coupling flanges on locating bosses extending from the second work structure and clamping the outlet coupling flange.    
   
   
       43 . The method of  claim 42 , wherein: 
 the additional interface surface is the outlet coupling flange interface surface; and    the step of supporting and clamping the manifold on the second work structure further includes the steps of positioning a plurality of flange work supports radially against a first radial side of the outlet coupling flange, radially pressing a plurality of clamp actuators against the opposite radial side of the outlet coupling flange.    
   
   
       44 . The method of  claim 43 , wherein the step of machining the additional interface surface includes the step of driving a cutting tool along the outlet coupling flange interface surface in a direction from the opposite radial side of the outlet coupling flange to the first radial side of the outlet coupling flange, whereby the cutting motion is driven into the plurality of flange work supports.  
   
   
       45 . The method of  claim 42 , wherein the additional interface surface is a surface of a peripheral manifold feature.  
   
   
       46 . The method of  claim 45 , wherein the additional manifold feature is taken from a group consisting of: an emission sensor projection and a heat shield projection.  
   
   
       47 . A method for machining a stainless steel exhaust manifold for a multi-cylinder combustion engine, the exhaust manifold having a manifold body that includes a plurality of inlet tubes in fluid communication with at least one outlet, each of the inlet tubes having an inlet mouth and a coupling flange extending radially therefrom, the outlet having an outlet mouth and a coupling flange extending radially therefrom, each of the inlet coupling flanges being arranged in a row and having an interface surface adapted to mate with the engine block, and the outlet coupling flange having an interface surface adapted to mate with the exhaust assembly, the method comprising the steps of: 
 supporting the manifold on a work structure;    clamping the manifold to the work structure, the clamping step including the step of clamping at least certain of the row of inlet coupling flanges separately; and    machining the interface surfaces of the inlet coupling flanges;    the step of clamping at least certain of the row of inlet coupling flanges separately including the steps of, 
 positioning a flange work support radially against each of the certain inlet coupling flanges, and  
 radially pressing a clamp actuator against each of the certain inlet coupling flanges at a point diametrically opposed to the flange work support.  
   
   
   
       48 . The method of  claim 47 , wherein: 
 the plurality of flange work supports are arranged in a row corresponding to the row of the inlet coupling flanges and are mounted on a pivotal support having a pivot axis substantially parallel to the row of flange work supports, so that the row of flange work supports are pivotable upward and away from the manifold, thereby providing an openable and closable, substantially compact clamping structure; and    the method further comprises the steps of, prior to the supporting step, opening the clamping structure and, subsequent to the supporting step, closing the clamping structure.    
   
   
       49 . The method of  claim 47 , wherein: 
 the plurality of clamp actuators are arranged in a row corresponding to the row of the inlet coupling flanges and are mounted on a pivotal support having a pivot axis substantially parallel to the row of clamp actuators, so that the row of clamp actuators are pivotable upward and away from the manifold, thereby providing an openable and closable, substantially compact clamping structure; and    the method further comprises the steps of, prior to the supporting step, opening the clamping structure and, subsequent to the supporting step, closing the clamping structure.    
   
   
       50 - 55 . (canceled)