Manufacturing method for an annular member and a pronged annular member

Abstract

A workpiece 20 b is formed that includes a circular bottom portion 22 b having a hole 23 b and an inner wall portion 24 b around the hole 23 b , and a skirt-shaped outer wall portion 25 b that includes prong portions 26 b on the outer circumference of the bottom portion 22 b and linking portions 27 b that link these prong portions 26 b , and by cutting off the linking portions 27 b and the portion that includes the inner wall portion 24 b from the formed workpiece, a pronged annular member that includes the circular bottom portion 22 b that has a hole 23 b and the prong portions 26 b on the outer circumference of the bottom portion 22 b.

1 . A manufacturing method for an annular member that manufactures an annular member that comprises an annular-shaped annular member and at least one prong formed substantially perpendicular on the outer circumference of this annular member, wherein: 
 (a) an annular base material is prepared;    (b) a workpiece is formed by one press process applied to this base material, the workpiece including a circular bottom portion having a hole in the center thereof and a skirt-shaped outer wall portion that comprises prong portions that form prongs on the outer circumference of this bottom portion and linking portions that link these prong portions; and    (c) a pronged annular member is formed by removing the linking portions from the formed workpiece.    
   
   
       2 . The manufacturing method for an annular member according to  claim 1 , characterized in that at least the steps (b) and after are carried out by using cold forging.  
   
   
       3 . The manufacturing method for an annular member according to  claim 1 , characterized in that at least the steps (b) and after do not carry out annealing.  
   
   
       4 . The manufacturing method for an annular member according to  claim 1 , wherein: 
 the step (b) is a step in which the workpiece is formed such that the outer diameter of the linking portions in the outer wall portion is larger than the outer diameter of the prong portions; and    the step (c) is a step that comprises a step (c 1 ) in which the linking portions are removed such that the linking portions in the outer wall portion are sheared off by a force that is applied in a direction from the prong portions towards the prongs.    
   
   
       5 . The manufacturing method for an annular member according to  claim 4 , wherein the step (b) is a step in which the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is larger than the inner diameter of the prong portions.  
   
   
       6 . The manufacturing method for an annular member according to  claim 4 , wherein the step (b) is a step in which the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is substantially identical to the outer diameter of the prong portions.  
   
   
       7 . The manufacturing method for an annular member according to  claim 4 , wherein the step (c 1 ) is a step in which the linking portions are removed and the portion of the workpiece that includes the hole in the bottom portion is cut off.  
   
   
       8 . The manufacturing method for an annular member according to  claim 1 , wherein the step (b) is a step in which the workpiece is formed such that the wall thickness of connecting portions, which are the portions that connect the prong portions and the linking portions, is thinner than the wall thickness of the prong portions and the wall thickness of the linking portions.  
   
   
       9 . The manufacturing method for an annular member according to  claim 1 , wherein the step (b) is a step in which the workpiece is formed such that the wall thickness of the linking portions is thinner than the wall thickness of the prong portions.  
   
   
       10 . The manufacturing method for an annular member according to  claim 1 , wherein the step (b) is a step in which the workpiece is formed such that the base of the inside of the prong portions at the bottom portion has a wall thickness through the radius that is larger in comparison to the base of the inside of the linking portions at the bottom portion.  
   
   
       11 . The manufacturing method for an annular member according to  claim 1 , wherein the step (c) is a step that comprises a step (c 2 ), in which the inner diameter of the prong portions is widened after the linking portions have been removed from the formed workpiece.  
   
   
       12 . The manufacturing method for an annular member according to  claim 1 , wherein the step (c) is a step that comprises a step (c 3 ), in which the trimming of the locations that link the prong portions and the linking portions is carried out after the linking portions have been removed from the formed workpiece.  
   
   
       13 . The manufacturing method for an annular member according to  claim 1 , wherein the step (c) is a step that comprises a step (c 4 ), in which one of at least the roughness and the evenness of the surface of at least the inside of the bottom portion are adjusted after the linking portions have been removed from the formed workpiece.  
   
   
       14 . The manufacturing method for an annular member according to  claim 13 , wherein: 
 the step (a) is a step in which a base material is prepared whose surface has been subject to a phosphating treatment that provides a surface coating that includes a metallic soap; and    the step (c 4 ) is a step in which at least one of the roughness and the evenness of the surface is adjusted after providing a treatment that removes the metallic soap.    
   
   
       15 . The manufacturing method for an annular member according to  claim 1 , wherein the step (b) is a step in which the workpiece is formed that has a cylindrical vertical wall portion that is concentric to the outer wall portion around the hole in the center of the bottom portion.  
   
   
       16 . The manufacturing method for an annular member according to  claim 15 , wherein the step (b) is a step in which the workpiece is formed such that the length up to the end portion of the vertical wall portion is adjusted by varying the wall thickness of the linking portions according to the distance from the prong portions.  
   
   
       17 . The manufacturing method for an annular member according to  claim 16 , wherein the step (b) is a step in which a workpiece is formed such that the wall thickness of the linking portions becomes continuously larger as the distance from the prong portions becomes larger.  
   
   
       18 . The manufacturing method for an annular member according to  claim 15 , wherein the step (b) is a step in which a workpiece is formed such that the inner circumferential surface of the vertical wall portion has a predetermined shape.  
   
   
       19 . The manufacturing method for an annular member according to  claim 18 , wherein the step (b) is a step in which a workpiece is formed such that the predetermined shape is a spline shape.  
   
   
       20 . The manufacturing method for an annular member according to  claim 15 , wherein the step (b) is a step in which the workpiece is formed having vertical wall portions that comprise a first vertical wall portion that is disposed in a direction identical to that of the outer wall portion with respect to the hole in the center of the bottom portion and a second vertical wall portion that is disposed in a direction that is opposed to that of the outer wall portion with respect to the hole in the center of the bottom portion.  
   
   
       21 . The manufacturing method for an annular member according to  claim 20 , wherein the step (c) is a step that comprises a step (c 5 ), in which the first vertical wall portion is removed from the workpiece after the linking portions have been removed from the formed workpiece.  
   
   
       22 . The manufacturing method for an annular member according to  claim 1 , wherein the annular member is a carrier in a planetary gear mechanism.  
   
   
       23 . A pronged annular member that comprises an annular-shaped annular member and at least one prong formed substantially perpendicular on the outer circumference of the annular member, wherein: 
 the pronged annular member is formed by removing the linking portions from a workpiece that is formed by one press process applied to an annular base material, the workpiece including a circular bottom portion that has a hole in the center thereof and a skirt-shaped outer wall portion that comprises prong portions that form prongs on the outer circumference of the bottom portion and linking portions that link the prong portions.    
   
   
       24 . The pronged annular member according to  claim 23 , wherein: 
 the workpiece is formed such that the outer diameter of the linking portions in the outer wall portion is larger than the outer diameter of the prong portions; and    the pronged annular member is formed by removing the linking portions such that the linking portions in the outer wall portion are sheared off by a force that is applied in a direction from the prong portions toward the prongs.    
   
   
       25 . The pronged annular member according to  claim 24 , wherein the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is larger than the inner diameter of the prong portions.  
   
   
       26 . The pronged annular member according to  claim 24 , wherein the workpiece is formed such that the inner diameter of the linking portions in the outer wall portion is substantially identical to that of the outer diameter of the prong portions.  
   
   
       27 . The pronged annular member according to  claim 23 , wherein the pronged annular member is formed by removing the linking portions and cutting off the portion of the workpiece that includes the hole in the bottom portion.  
   
   
       28 . The pronged annular member according to  claim 23 , wherein the workpiece is formed such that the wall thickness of the connecting portions, which are the portions that connect the prong portions and the linking portions, are thinner than the wall thickness of the prong portions and the wall thickness of the linking portions.  
   
   
       29 . The pronged annular member according to  claim 23 , wherein the workpiece is formed such that the wall thickness of the linking portions is thinner than the wall thickness of the prong portions.  
   
   
       30 . The pronged annular member according to  claim 23 , wherein the workpiece is formed such that the base of the inside of the prong portions at the bottom portion has a wall thickness across the radius that is larger in comparison the base of the inside of the linking portions at the bottom portion.  
   
   
       31 . The pronged annular member according to  claim 23 , wherein the pronged annular member is formed such that the inner diameter of the prong portions is widened after the linking portions have been removed from the formed workpiece.  
   
   
       32 . The pronged annular member according to  claim 23 , wherein the pronged annular member is formed by carrying out trimming of the locations that link the prong portions and the linking portions after the linking portions have been removed from the formed workpiece.  
   
   
       33 . The pronged annular member according to  claim 23 , wherein the pronged annular member is formed by adjusting at least one of the roughness and the evenness of at least the inside surface of the bottom portion after the linking portions have been removed from the formed workpiece.  
   
   
       34 . The pronged annular member according to  claim 33 , wherein: 
 the annular base material is a base material on which a phosphating treatment that provides a surface coating that includes a metallic soap has been carried out on the surface thereof; and    the pronged annular member is formed by adjusting at least one of the roughness and the evenness of the surface after providing a treatment that removes the metallic soap.    
   
   
       35 . The pronged annular member according to  claim 23 , wherein the workpiece is a member that has a cylindrical vertical wall portion that is concentric to the outer wall portion along the hole in the center of the bottom portion.  
   
   
       36 . The pronged annular member according to  claim 35 , wherein the workpiece is formed by adjusting the length to the end portion of the vertical wall portion by varying the wall thickness of the linking portions according to the distance from the prong portions.  
   
   
       37 . The pronged annular member according to  claim 36 , wherein the workpiece is formed such that the wall thickness of the linking portions becomes continuously larger as the distance from the prong portions becomes larger.  
   
   
       38 . The pronged annular member according to  claim 35 , wherein the workpiece is formed such that the inner circumferential surface of the vertical wall portions has a predetermined shape.  
   
   
       39 . The pronged annular member according to  claim 38 , wherein the workpiece is formed such that the inner circumferential surface of the vertical wall portions has a spline shape.  
   
   
       40 . The pronged annular member according to  claim 35 , wherein the workpiece has vertical wall portions formed thereon, the vertical wall portions including a first vertical wall portion having a direction that is identical to that of the outer wall portion with respect to the hole in the center of the bottom portion and a second vertical wall portion having a direction that is opposed to that of the outer wall portion with respect to the hole in the center of the bottom portion.  
   
   
       41 . The pronged annular member according to  claim 40 , wherein the pronged annular member is formed by removing the first vertical wall portion from the workpiece after the linking portions have been removed from the formed workpiece.  
   
   
       42 . The pronged annular member according to  claim 23 , wherein the pronged annular member is a carrier in a planetary gear mechanism.